Title of Invention	OVERHEAD CONVEYOR
Abstract	An overhead conveyor having carrier (2) connected to front and rear trolleys (4,4) engaging travel rail (R), hanger (3) capable of changing the state of its engagement with carrier (2) and the state of release of the engagement, tow bar (23) forming a Vertical swing three-joint link mechanism for connecting carrier (2) and hanger (3), and engagement/release switching means for switching between the engaged state and the released state, wherein the engagement/release switching means enables switching between the engaged state where hanger (3) moves with carrier (2) in a united form and the released state where hanger (3) is towed by tow bar (23) while being supported by hanger guiding rail (HR) provided under travel rail (R). The height of an article to be conveyed can be changed to a height suitable for the job.

Title of Invention

OVERHEAD CONVEYOR

Abstract

An overhead conveyor having carrier (2) connected to front and rear trolleys (4,4) engaging travel rail (R), hanger (3) capable of changing the state of its engagement with carrier (2) and the state of release of the engagement, tow bar (23) forming a Vertical swing three-joint link mechanism for connecting carrier (2) and hanger (3), and engagement/release switching means for switching between the engaged state and the released state, wherein the engagement/release switching means enables switching between the engaged state where hanger (3) moves with carrier (2) in a united form and the released state where hanger (3) is towed by tow bar (23) while being supported by hanger guiding rail (HR) provided under travel rail (R). The height of an article to be conveyed can be changed to a height suitable for the job.

Full Text	FORM 2 THE PATENT ACT 1970 (39 of 1970) The Patents Rules, 2 003 COMPLETE SPECIFICATION (See Section 10, and rule 13) 1. TITLE OF INVENTION OVERHEAD CONVEYOR 2. APPLICANT(S) a) Name b) Nationality c) Address :NAKANISHI METAL WORKS CO., LTD. :JAPANESE Company :3-3-5, TENMABASHI, :KITA-KU, OSAKA-SHI, OSAKA, 5308566 JAPAN 3. PREAMBLE TO THE DESCRIPTION The following specification particularly describes the and the manner in which it is to be performed : - invention Specification [Technical Field] The present invention relates to an overhead conveyor which can be used to handle articles having different sizes and/or shapes to be conveyed on the same production line such as, for example, an assembly line of car bodies for various types of car, to convey said articles by a hanger suspended from a carrier capable of traveling on a travel rail. [Background Art] The overhead conveyor comprises a carrier with a roller rolling on a travel rail installed in a space above workers (in the vicinity of the factory ceiling, for example) and a hanger which is suspended from said carrier and equipped with article bearing unit laterally mounted on its lower part. Furthermore, said carrier is driven by a power-chain drive unit, a friction-roller drive unit or the like. When such an overhead conveyor as mentioned above is used on an assembly line of car bodies for various types of car, it is necessary to execute the conveyor such that the height of articles supported on said hanger may be appropriately changed depending on the job, thereby preventing workers from working with an abnormal working pose which could adversely affect their workability and safety. Conventional overhead conveyors having such an aim as mentioned above have been already disclosed: an overhead conveyor comprising a power-chain conveyor rail to movably guide a power-chain, a trolley rail installed underneath said power-chain conveyor rail extending parallel to the power-chain conveyor rail to movably guide a trolley being driven by said power-chain, a first hanger connected to said trolley, a second hanger equipped with a hanger arm connected to said first hanger via an expansion mechanism in a vertical direction (such as panta-graph mechanism, for example) and bearing an article to be conveyed, and a guiding rail installed underneath said trolley rail extending parallel to the trolley rail to guide said second hanger, wherein said guide rail comprises a stepped guide part at a position to lift up said second hanger and a sloped guide part connected to said step-guide part (refer to the Patent document 1, for example), or an overhead conveyor, wherein a support for an article to be conveyed is detachably provided on a moving body freely movable on a constant path by the support and guide of a rail device, a support-conveying path 2 positioned below said constant path and along the constant path is placed at a predetermined position on the constant path, a separation means for removing said support from the specified moving body and transferring it to said support-conveying path is positioned at the starting part of the support-conveying path, and a joining means for bringing the support of the support-conveying path into abutment with the moving body is positioned at the end part of the support-conveying path (refer to the Patent document 2, for example). Furthermore, a related known art has disclosed a conveyor device which can keep conveying attachments (including frames, hangers and the like) horizontal both at a sloped section and a level section on an article-conveying path for conveying articles to different heights, wherein front and rear trolleys are suspended freely movable by the intervention of rollers from a rail constructed along a certain path, front and rear hangers are pivotally supported by and hanged down from the vicinity of the front and rear ends of a frame located at the lower side of said front and rear trolleys nearly parallel to their traveling direction, making the distance between at least one of the front and rear trolleys and said frame changeable, bringing the other trolley and the frame into a pivotal support state, enabling the frame to freely swing round the pivotal support portion in a vertical direction, mounting a roller at a position of the frame and installing a cam rail carrying said roller along a sloped section of said path (refer to the Patent document 3, for example). [Patent document 1] Japan patent application No. H01-181615 [Patent document 2] Japan patent application No. 2003-306143 [Patent document 1] Japan utility model No. S42-1144 [Disclosure of the Invention] [Problems to be Solved by the Invention] In said conventional overhead conveyor as per the Patent document 1, there are several problems: a) said first hanger (carrier) and said second hanger equipped with the hanger arm carrying said articles to be conveyed are connected vertically via said expansion mechanism, and it is thus necessary to install a guiding rail working both to prevent the second hanger from swinging and to guide its movement up and down over the overall length of the conveyor; b) the structure of the vertical expansion mechanism is complicated, and especially when a panta-graph mechanism is employed as a vertical expansion mechanism, it is necessary to fit a guiding device 3 slidably guiding one of the upper ends of the horizontal panta-graph mechanism to the first hanger and a guiding device slidably guiding the lower end immediately under one of the upper ends of the horizontal panta-graph mechanism to the second hanger, thereby causing its reliability to be lowered and its manufacturing costs to be increased. In the structure as per the Patent document 2, said moving body (carrier) and said support part for articles to be conveyed are completely separated, and it is thus necessary to add a moving power assigning means to said separation means, said joining means and said separated support part, and the control for said separation and joining is complicated, thereby causing its reliability to be lowered and its manufacturing costs to be increased. Furthermore, when the structure as per the Patent document 3 is utilized to make the height of said front and rear hangers changeable relative to the carrier (said front and rear trolleys) so that the height of articles supported by the hangers may be changed to be suitable for the job, the center of said carrier in a longitudinal direction (the center between the front and rear trolleys in a longitudinal direction) and the center of said front and rear hangers in a longitudinal direction are to be changed, depending on the height of the hangers relative to the carrier (the hangers move toward the carrier in a longitudinal direction). Such movement of the hangers in a longitudinal direction is remarkable, especially in the case that the difference in height between the carrier and hangers increases. Thus, there exists a problem that an article conveyed by a certain carrier and hanger might occasionally collide or have contact with another article conveyed by another carrier and hanger preceding or following said ones. Furthermore, the problem of decreased productivity will also occur when the distance between articles to be conveyed is made bigger to avoid that collision or contact as mentioned above. The present invention has been completed to solve the above-mentioned problems and aims to provide an overhead conveyor which is of simple structure but can reliably change the height of articles to be conveyed when they are supported by said hangers, so that their height will be appropriate for each job, and to improve the workability and reliability in addition to decreasing manufacturing costs. It can further control the movement of the articles in a longitudinal direction even when the differences in height of the carrier and hangers increase, so that collision and/ or contact between articles to be conveyed may be substantially avoided. 4 [Means to Solve the Problems] To solve said problems, an overhead conveyor according to the present invention consists of a carrier comprising at least one pair of front and rear trolleys engaging a travel rail, a longitudinal carrier frame connected to said trolleys extending in a longitudinal direction and having at its front and rear portions the front and rear engaging holes drilled in a lateral direction on said carrier side, and a lateral carrier frame fitted laterally to the front portion of said longitudinal carrier frame, a hanger comprising a hanger frame bearing a front plate with engaging holes on the hanger side drilled in a lateral direction at positions corresponding to said front engaging holes on the carrier side and a rear plate with engaging holes on the hanger side drilled in a lateral direction at positions corresponding to said rear engaging holes on the carrier side, and a hanger arm suspended from said hanger frame to bear articles to be conveyed, a hanger guiding rail installed under said travel rail to bear said hangers, a tow bar comprising a first link, of which front end pivotally touches said lateral carrier frame, capable of swinging round the lateral axis and extending to the rear over the rear end of said hanger frame, and a second link, of which rear end pivotally touches the rear end of said first link, capable of swinging round the lateral axis and of which front end pivotally touches the rear end of said hanger frame, capable of swinging round the lateral axis, a swing control means for said second link to control its forward swinging up to a predetermined angle, a swing control means for said first link to control its downward swinging up to a predetermined angle, or an enlargement control means for included angle to control the included angle between said first and second links up to a predetermined angle, and an engagement/release switching means which enables switching between the front engaged state where the front engagement pin engaging said front engagement hole on the carrier side is engaged with said front engagement hole on the hanger side and the front released state where the front engagement is released, and switching between the rear engaged state where the rear engagement pin engaging said rear engagement hole on the carrier side is engaged with said rear engagement hole on the hanger side and the rear released state where the rear engagement is released, wherein the height of articles to be conveyed which are supported by said hanger arm can be changed by said engagement/release switching means which switches between said front and rear engaged states where said hanger moves with the carrier in a united form and said front and rear released states where said hanger supported by said hanger guiding rail moves in traction by said tow bar. It is preferable to provide an overhead conveyor, wherein a predetermined angle of 5 said second link forward swinging to be controlled by said swing control means for the second link, a predetermined angle of said first link downward swinging to be controlled by said swing control means for the first link, or a predetermined angle of included angle between the first and second links to be controlled by said enlargement control means for included angle can be set in such a manner that the relative positional relationship between the center of said front and rear trolleys in a longitudinal direction and the center of said front and rear hangers in a longitudinal direction is nearly equal between said front and rear engaged states and said front and rear released states. It is preferable that said swing control means for the second link brings the front projection of the second link into abutment with said hanger frame. It is further preferable that said engaging pins move in a lateral direction in such a manner that said engagement/release switching means connects said engaging pins to a lateral swing link mounted in front of and behind said longitudinal carrier frame swinging in a lateral direction and that a cam follower mounted on said lateral swing link is engaged with a cam rail mounted on the conveying path to swing the lateral swing link by driving said cam rail in a lateral direction. It is further preferable that the positioning for mating said engaging pins with said engaging holes on the hanger side to perform switching from said released state to said engaged state is carried out by bringing a roller mounted on the pivot between the first and second links of said tow bar into contact with the cam rail mounted on the conveying path. It is preferable that said articles to be conveyed are kept nearly horizontal in a sloped ascending section or a sloped descending section of said travel rail by installing a hanger guiding rail which supports said hangers to keep them nearly horizontal in such a manner that the overhead conveyor is switched to said front released state and rear engaged state in said sloped ascending section, while the overhead conveyor is switched to said front engaged state and rear released state in said sloped descending section. [Effect of the Invention] The overhead conveyor according to the present invention consists of a carrier comprising at least one pair of front and rear trolleys engaging a travel rail, a 6 longitudinal carrier frame connected to said trolleys extending in a longitudina direction and having at its front and rear portions the front and rear engaging hole! drilled in a lateral direction on said carrier side, and a lateral carrier frame fitted laterally to the front portion of said longitudinal carrier frame, a hanger comprising £ hanger frame bearing a front plate with engaging holes on the hanger side drilled in £ lateral direction at positions corresponding to said front engaging holes on the carried side and a rear plate with engaging holes on the hanger side drilled in a lateral direction at positions corresponding to said rear engaging holes on the carrier side, and a hanger arm suspended from said hanger frame to bear articles to be conveyed, a hanger guiding rail installed under said travel rail to bear said hangers, a tow bail comprising a first link, of which front end pivotally touches said lateral carrier frame; capable of swinging round the lateral axis and extending to the rear over the rear end of said hanger frame, and a second link, of which rear end pivotally touches the real end of said first link, capable of swinging round the lateral axis and of which front end pivotally touches the rear end of said hanger frame, capable of swinging round the lateral axis, a swing control means for said second link to control its forward swinging up to a predetermined angle, a swing control means for said first link to control its downward swinging up to a predetermined angle, or an enlargement control means for included angle to control the included angle between said first and second links up to a predetermined angle, and an engagement/release switching means which enables switching between the front engaged state where the front engagement pin engaging said front engagement hole on the carrier side is engaged with said front engagement hole on the hanger side and the front released state where the front engagement is released, and switching between the rear engaged state where the rear engagement pin engaging said rear engagement hole on the carrier side is engaged with said rear engagement hole on the hanger side and the rear released state where the rear engagement is released, wherein the height of articles to be conveyed which are supported by said hanger arm can be changed by said engagement/release switching means which switches between said front and rear engaged states where said hanger moves with the carrier in a united form and said front and rear released states where said hanger supported by said hanger guiding rail moves in traction by said tow bar, and thus, the height of articles to be conveyed can be reliably changed to that suitable for the job, although the system is of simple structure, and improved workability and reliability can be realized, in addition to achieving the reduction of manufacturing costs. Furthermore, it is possible to control the forward or backward movement of the articles to be conveyed even when the differences in height of the carrier and hangers increase, and collision and/or contact between the articles to be 7 conveyed may be substantially avoided. A predetermined angle of said second link forward swinging to be controlled by said swing control means for the second link, a predetermined angle of said first link downward swinging to be controlled by said swing control means for the first link, or a predetermined angle of included angle between the first and second links to be controlled by said enlargement control means for included angle can be set in such a manner that the relative positional relationship between the center of said front and rear trolleys in a longitudinal direction and the center of said front and rear hangers in a longitudinal direction is nearly equal between said front and rear engaged states and said front and rear released states, and thus collision and/or contact between the articles to be conveyed may be more reliably avoided. According to the overhead conveyor of the present invention, said swing control means for the second link brings the front projection of the second link into abutment with said hanger frame, and it is thus possible to control more easily collision and/or contact between the articles to be conveyed. Furthermore, according to the overhead conveyor of the present invention, said engaging pins move in a lateral direction in such a manner that said engagement/release switching means connects said engaging pins to a lateral swing link mounted in front of and behind said longitudinal carrier frame swinging in a lateral direction and that a cam follower mounted on said lateral swing link is engaged with a cam rail mounted on the conveying path to swing the lateral swing link by driving said cam rail in a lateral direction, and it is thus possible to provide said engagement/release switching means which can conduct said engagement and release easily and reliably without installing drive means on said carriers and hanger. In the overhead conveyor according to the present invention, positioning for mating said engaging pins with said engaging holes on the hanger side to perform switching from said released state to said engaged state is carried out by bringing a roller mounted on the pivot between the first and second links of said tow bar into contact with the cam rail mounted on the conveying path, and it is thus possible to conduct the positioning between said engaging pin and said engaging holes easily and reliably. In the overhead conveyor according to the present invention, said articles to be 8 conveyed are kept nearly horizontal in a sloped ascending section or a sloped descending section of said travel rail by installing a hanger guiding rail which supports said hangers to keep them nearly horizontal in such a manner that the overhead conveyor is switched to said front released state and rear engaged state in said sloped ascending section, while the overhead conveyor is switched to said front engaged state and rear released state in said sloped descending section, and thus the hanger is not inclined even when said carrier moves in inclined pose in said sloped section and it is possible to prevent the articles from dropping out of the hanger. [Brief Explanation of the Drawings] [Fig. 1] is a right side view showing the overhead conveyor according to an embodiment of the present invention. [Fig. 2] is a plan view showing the bottom of a trolley of the overhead conveyor according to an embodiment of the present invention. [Fig. 3] is a rear view showing the overhead conveyor according to an embodiment of the present invention. [Fig. 4] is a rear view to explain the engagement/release switching means: (a) is a view to explain its operation, and (b) is an enlarged view to show an engaged state between an engaging pin and an engaging hole on the hanger side. [Fig. 5] is a view to explain the operation which enables the height of an article supported by the hanger arm to be changed. [Fig. 6] is a view to explain the operation which enables the height of an article supported by the hanger arm to be changed. [Fig. 7] is a view to explain a positioning cam rail installed on the conveying path. [Fig. 8] is a rear view showing a state where an article to be conveyed is brought to a height suitable for the job (higher position of the article). [Fig. 9] is a rear view showing a state where an article to be conveyed is brought to a height suitable for the job (lower position of the article). [Best Embodiment to Carry out the Invention] An embodiment of the present invention is explained in detail hereinafter according to the attached drawings, and the present invention should not be limited only to the embodiment shown in said drawings, but should include all the embodiments satisfying the requirement described in the claims. As per the specification of the present invention, it should be noted that the direction toward which the carrier advances along the travel rail means "front" (refer to "arrow A" in the drawings) 9 while the opposite direction means "rear", and "right and left" sides means those when man looks at the carrier from front toward rear. Figs. 1 to 3 are explanatory views showing an embodiment of the overhead conveyor according to the present invention: Fig. 1 is a right side view, Fig. 2 is a plan view showing the bottom of a trolley and Fig. 3 is a rear view (seen from the rear). In Fig. 3, the trolley engaged with rail R is load-trolley 4. The overhead conveyor 1 consists of carrier 2 capable of running along the travel rail R, hanger 3 suspended from the carrier 2 to bear article W1 or W2 to be conveyed, etc. Carrier 2 comprises front and rear load-trolleys 4, 4, leading trolley 5, tail-trolley 6, expansible drive rod 7 connecting front and rear load-trolleys 4, 4, connecting rod 8 connecting front load-trolley 4 and leading trolley 5, connecting rod 9 connecting rear load-trolley 4 and tail-trolley 6, longitudinal carrier frames 10, 10 installed between front and rear load-trolleys 4, 4, longitudinally extending, and at their front and rear parts front engaging hole 10a on the carrier side and rear engaging hole 10b on the carrier side are drilled in a lateral direction, and lateral carrier frame 11 installed in a lateral direction at the front parts of said longitudinal carrier frames 10,10. The front and rear load-trolleys 4,4 have a vertical roller 4a rolling on the travel rail R that is a nearly I-formed mono-rail, for example, and capable of rotating round the lateral axis, and horizontal rollers 4b, 4b capable of rotating round the vertical axis, and engage the travel rail R. The leading trolley 5 has a vertical roller 5a rolling on the travel rail R and capable of rotating round the lateral axis and horizontal rollers 5b, 5b capable of rotating round the vertical axis, and engages the travel rail R. The tail-trolley 6 has a vertical roller 6a rolling on the travel rail R and capable of rotating round the lateral axis, and horizontal rollers 6b, 6b capable of rotating round the vertical axis, and engages the travel rail R. On the right and left sides of the front and rear load-trolleys 4, 4, leading trolley 5, tail-trolley 6, drive rod 7 and connecting rods 8,9, a nearly vertical face is built, which a friction roller (not shown) installed on the conveying path touches laterally, and the driving power of said friction roller gives the carrier 2 a thrust force, so that the carrier 2 can run along the travel rail R. The hanger 3 comprises front right/left and rear right/left frames 13 to 16, right and left support members 17, 17 projected onto the rear part of said frame 14, a hanger 10 frame 12 bearing a front plate 18 with a front engaging hole 18a laterally projected at a position corresponding to said front engaging hole 10a on the carrier side and a rear plate 19 with a rear engaging hole 19a laterally projected at a position corresponding to said rear engaging hole 10b on the carrier side, and hanger arms 20, 20 suspended from said hanger frame 12 and bearing an article W1 or W2 to be conveyed. The carrier 2 and the hanger 3 are connected by a first link 21 of which front end 21a pivotally connects the lateral carrier frame 11 so as to he capable of swinging round the lateral axis, and which extends backwards over the rear end of the hanger frame 12, that is, the rear end of the support members 17 projected onto the rear part of the rear frame 14, and a second link 22 of which rear end 22b pivotally connects the rear end 21b of the first link 21 so as to be capable of swinging round the lateral axis, and of which front end 22a pivotally connects the rear end of said hanger frame 12 so as to be capable of swinging round the lateral axis. The first link 21 and second link 22 structured as mentioned above form tow bars 23,23 which are located on the right and left sides and are a vertically swinging three-joint link mechanism. The forward swing of the second link 22 is controlled in such a manner that front protrusion 24 forming second link swing control means (to be explained below) touches the upper face of the hanger frame 12 (upper frame of the support member 17 projected onto the rear part of the rear frame 14). Fig. 4 is a rear view to explain an engagement/release switching means 26 (view seen from rear) which can perform switching from the front engaged state where a front engaging pin 25a engaged with a front engaging hole 10a on the carrier side is engaged with a front engaging hole 18a on the hanger side to the front released state where said engagement is released, and the rear engaged state where a rear engaging pin 25b engaged with a rear engaging hole 10b on the carrier side is engaged with a rear engaging hole 19a on the hanger side to the rear released state where said engagement is released, and vice versa. Fig. 4(a) is a view to explain its operation, and Fig. 4(b) is an enlarged view to show the engaged state between the front engaging pin 25a and the front engaging hole 18a on the hanger side. Fig. 4 shows an engagement/release switching means on the front side, that is, a switching means which switches from the front engaged state where the front engaging pin 25a engaged with the front engaging hole 10a on the carrier side is engaged with the front engaging hole 18a on the hanger side to the front released state where said front engagement is released, and an engagement/release switching means on the rear side, that is, a switching means which switches from the rear engaged state where a rear 11 engaging pin 25b engaged with a rear engaging hole 10b on the carrier side is engaged with a rear engaging hole 19a on the hanger side to the rear released state where said engagement is released, is of similar structure to said means. Said front engaging pin 25a is connected to lateral swing link 27 of near L-form laterally swinging, attached pivotally to bracket 29 fixed to the front part of the longitudinal carrier frame l0 so as to be capable of swinging round a longitudinal axis 29a, and a cam follower 28 is mounted on the upper end of the link. At a predetermined position on the conveying path a cam rail 30 is installed, which has an engaging portion 30a engaging with said cam follower 28 and is capable of swinging round the longitudinal axis 30b, and the upper end 30c of the cam rail 30 is connected to a rod 31a of an air cylinder 31. When the air cylinder 31 is thus driven to move the rod 31a back and forth in the engagement state of the cam follower 28 of lateral swing link 27 of near L-form with an engaging part 30a of the cam rail 30 at a predetermined position of the conveying path, the cam rail 30 swings round the longitudinal axis 30b, the lateral swing link 27 swings in a lateral direction and the front engaging pin 25a also moves in a lateral direction. As a result, extending the rod of the air cylinder 31 makes it possible to realize the front engaged state where the front engaging pin 25a is engaged with the front engaging hole 18a on the hanger side as per the two-dot chain line in Fig. 4, and retreating the rod of the air cylinder 31 makes it possible to realize the front released state where the front engaging pin 25a is pulled out of the front engaging hole 18a on the hanger side as per the solid line in Fig. 4. By a similar structure and operation, said rear engaged state and rear released state may be also realized. By using that structure, it is possible to provide said engagement/release switching means 26 that is able to perform said engagement and release easily and reliably without the need to install any extra drive means. The front engaging pin 25a is structured such that the outer diameter of its tip is bigger than the outer diameter of the part bearing the front plate 18 (for example, the outer diameter d0 in Fig. 4(b) is approx. 50mm, and the outer diameter dl is approx. 40mm). When the front engaging pin 25a is thus going to move from the front engaging hole 18a on the hanger side to the disengaging direction in the front engaged state, that is, in the state where the front plate 18 is born by the front engaging pin 25a, the tip (part of the outer diameter d0) of the front engaging pin 25a touches the side face of the front plate 18, so that it is possible to hold the front engaging pin 25a to be 12 pulled out of the front engaging hole 18a on the hanger side. In addition, a pressure coil spring 32 is interposed between a lower end 27a of the lateral swing link 27 of nearly L-form and the bottom of the lateral carrier frame 10 and the front engaging pin 25a is biased by a restoring force of said spring toward the front engaging hole 18a on the hanger side, so that it is possible to avoid an accident that the engagement of the front engaging pin 25a with the front engaging hole 18a on the hanger side is suddenly released and the hanger 3 falls from the carrier 2. Figs. 5 and 6 are a view to explain the operation which enables the height of an article supported by said hanger arm to be changed using a switching function enabling the switching between the engaged state and released state by said engagement/release switch means. Fig. 5 shows a case in which the hanger guiding rail HR branches to the high hanger guiding rail HRH and the low hanger guiding rail HRL, and Fig. 6 shows a case in which the high hanger guiding rail HRH and low hanger guiding rail HRL join the hanger guiding rail HR. The state at the position B in Fig. 5 shows a state where, as said front engagement and rear engagement state, vertical rollers 33, 33 which can rotate round lateral axes mounted in front of and behind right and a left frames 15,16 of the hanger frame 12 (refer to Figs. 2 and 3) are engaged with the hanger guiding rail HR by said engagement/release switch means. It is possible to change the system from this state to said front released state and rear released state by said engagement/ release switch means, so that the state of the position C in Fig. 5, that is, the state where said vertical rollers 33, 33 are engaged with the low hanger guiding rail HRL and the hanger 3 is trailed by the tow bar 23 to travel is realized. In this case, to engage said vertical rollers 33, 33 with the high hanger guiding rail HRH in the state of said position C, the system should run from the position B in said front engaged and rear engaged state and a horizontal projection above the hanger guiding rail HR (refer to Fig. 3) should be removed at a position in front of the branch part of the hanger guiding rail HR (refer to "L" in Fig. 5) so as to make the section of the hanger guiding rail HR to be a nearly L-form. In such a way, at the position C, for example, the height of the hanger and an article to be conveyed (e.g. W2) which the hanger bears can be changed easily and reliably. Thus, the height of articles to be conveyed can be changed easily and reliably to that suitable for the job so as to avoid such a situation that workers have to work, standing on the floor FL with an unsuitable pose, resulting in reduced workability and safety, so that improvement in 13 workability and reliability can be realized, in addition to reduction of the manufacturing costs. The hanger 3 is trailed by the carrier 2 via the tow bar 23 in both said front and rear released states, as the position C in Fig.5 shows, and it is thus possible to reduce the manufacturing costs without the need to install an extra means to drive the hanger 3. The forward swing of the second link 22 in the state of C position in Fig. 5 is controlled by the structure to bring the front projection 24 of the second link 22, that is, the second link swing control means to limit the forward swing of the second link up to a predetermined angle, into abutment with the upper face of the hanger frame 12, that is, the upper face of the support member 17 projected onto the rear part of the rear frame 14. In that state where the forward swing of the second link 22 is controlled by the second link swing control means, a predetermined angle to control the forward swing of the second link is set, similarly as the position B in Fig. 5, so that the center between the front and rear load-trolleys 4, 4 in a longitudinal direction nearly conforms with the center of the hanger 3 in a longitudinal direction (refer to "CL" in Fig. 5). It should be also noted that the center between the front and rear load-trolleys 4, 4 in a longitudinal direction need not always conform with the center of the hanger 3 in a longitudinal direction, but said predetermined angle should be set such that the relative positional relationship of the center between the front and rear load-trolleys 4, 4 in a longitudinal direction with the center of the hanger 3 in a longitudinal direction in said front engaged and rear engaged states (e.g. state of the position B in Fig. 5) nearly conforms with that in said front released and rear released states (e.g. state of the position C in Fig. 5). It is thus possible by that simple structure to control the movement of the articles to be conveyed in a longitudinal direction even when the differences in height of the carrier 2 and hangers 3 increase by the change of height of the articles, and collision and/or contact between the articles to be conveyed may be substantially avoided. Instead of using said second link swing control means, it may be allowed to employ a first link swing control means to limit the downward swing of the first link 21 up to a predetermined angle. Said first link swing control means can be formed by providing a control plate 41 on the bottom of the lateral carrier frame 11 (refer to the position C in Fig. 5). In the case of employing that first link swing control means, it is possible to control the movement of the articles to be conveyed in a longitudinal 14 direction even when the differences in height of the carrier 2 and hangers 3 increase by the change of height of the articles, and collision and/or contact between the articles to be conveyed may be substantially avoided, by setting a predetermined angle for the downward swing of the first link such that the relative positional relationship of the center between the front and rear load-trolleys 4,4 in a longitudinal direction with the center of the hanger 3 in a longitudinal direction is nearly equal regardless of the differences in height of the articles to be conveyed. Instead of using said second link swing control means or first link swing control means, it may be also allowed to employ an included angle enlargement control means to limit the included angle between the first link 21 and the second link 22 up to a predetermined angle (refer to the angle a in Fig. 5). Said included angle enlargement control means can be formed by fitting a stopper on or in the vicinity of the pivot axis for the rear end 21b of the first link 21 and the rear end 22b of the second link 22 to limit the included angle between the first link 21 and the second link 22 up to a predetermined angle. In the case of employing that included angle enlargement control means, it is possible to control the forward or backward movement of the articles to be conveyed even when the differences in height of the carrier 2 and hangers 3 increase by the change of height of the articles, and collision and/ or contact between the articles to be conveyed may be substantially avoided, by setting a predetermined angle for the included angle (refer to the anglea in Fig. 5) such that the relative positional relationship of the center between the front and rear load-trolleys 4, 4 in a longitudinal direction with the center of the hanger 3 in a longitudinal direction is nearly equal regardless of the differences in height of the articles to be conveyed. The positions D and E in Fig. 6 show said front and rear released states and the positions F and G in Fig. 6 show said front and rear engaged states. When said front and rear released states of the position E changes into said front and rear engaged states of the position F, positioning between the engaging pins and engaging holes can be obtained easily and reliably by setting the distance between the travel rail R and the hanger guiding rail HR so that the front engaging pin 25a mates with the front engaging hole 18a on the hanger side and the rear engaging pin 25b mates with the rear engaging hole 19a on the hanger side after the low hanger guiding rail HRL joins the high hanger guiding rail HRH from a state where said vertical rollers 33,33 of the hanger frame 12 are engaged with the low hanger guiding rail HRL, and by bringing the rollers 36,36 mounted on the pivot axis between the rear end 21b of the first link 21 and the rear end 22b of the second link 22 forming said tow bar 23 (refer to Figs. 2 and 15 3) into abutment with the positioning cam rail 38 installed on the conveying path shown in Fig. 7. After completing said positioning, it is possible to bring the system into said front and rear engaged states easily and reliably by the engagement/release switch means 26 shown in Fig. 4. The fit between the front engaging pin 25a and the front engaging hole 18a on the hanger side as well as between the rear engaging pin 25b and the rear engaging hole 19a on the hanger side is formed as clearance fit with an increased clearance. For example, d0 and dl in Fig. 4 (b) are approx. 50mm and 40mm, respectively, whereas the inner diameter Dl of the front engaging hole 18a on the hanger side is in the range of 60 to 70mm. Thus, it is possible to carry out both the engagement between the front engaging pin 25a and the front engaging hole 18a on the hanger side and the separation (release of said engagement) more easily and reliably. For example, even when some error exists in the distance between the travel rail R and the hanger guiding rail HR or in the fitting position of the cam rail 38 for positioning, it is possible owing to said clearance to reliably perform the change into said front and rear engaged states. Furthermore, it is possible owing to said clearance to use the overhead conveyor 1 totally over a long period by replacing only said worn out rails or the like as an exhaustion, when the rail R, rollers 4a, 4b of the trolley 4 or the hanger guiding rail HR etc. are worn out. It is also possible to keep articles to be conveyed nearly horizontal by installing the hanger guiding rail HR bearing said vertical rollers 33,33 to keep the hanger 3 (articles to be conveyed) nearly horizontal, while the system is brought into the front released state and the rear engaged state in the ascending section of the travel rail R by the engagement/release switch means, and the system is brought into the front engaged state and the rear released state in the descending section of the travel rail R by the engagement/release switch means. Thus, the hanger 3 is not inclined even when said carrier moves with inclined pose in said sloped section and it is possible to prevent the articles from dropping out of the hanger 3. It may be also allowed to employ a scheme in which only the travel rail R is used, disposing the hanger guiding rail HR, and the system is brought into only the front and rear engaged states in a non-working region exclusively for transport, and the switching between the engagement and release is conducted by the engagement/release switch means in a working region where the hanger guiding rail HR is installed. 16 Figs. 8 and 9 are a rear view showing a state where an article to be conveyed is brought to a height suitable for the job (seen from the rear). A trolley engaging the rail R in Figs. 8 and 9 shows the load-trolley 4. Fig. 8 shows the front and rear engaged states brought by the engagement/release switch means, where the position of the article Wl to be conveyed is comparatively high and suitable for the case when a worker standing on the floor FL, for example, attaches a part to the bottom of the article Wl. And Fig. 9 shows the front and rear released states brought by the engagement/release switch means, where the position of the article W1 to be conveyed is comparatively low and suitable for the case when a worker standing on the floor FL, for example, attaches a part to the side of the article W1. The engaged state and released states can be easily switched by the engagement/release switch means as explained above, and it is thus possible to easily change the height of the article to be conveyed depending on the size of the article (refer to the articles W1, W2, for example, in Fig. 1) or depending on the position where any work on the article to be conveyed is carried out, by controlling the height of the hanger guiding rail HR after the vertical rollers 33,33 capable of rotating round the lateral axes interposed in front of and behind the left and right frames 15,16 of the hanger frame 12 are engaged with the hanger guiding rail HR. Thus, the height of articles to be conveyed can be reliably changed to that suitable for the job, though it is of simple structure, so that improved workability and reliability can be realized, in addition to the reduction of the manufacturing costs. Lateral anti-swing rollers 34,34, guiding rail (such as hanger guiding rail HR), vertical anti-swing rollers 35, 35 and guiding rails 37, 37 are installed in the working region shown in Figs. 8 and 9, by which the reduced workability due to swinging of the article to be conveyed in the working region can be prevented. When engaging dog 40 mounted on the lateral carrier frame 11 of the carrier 2 is engaged with the roller-chain type drive unit 39 installed in the working region shown in Figs. 8 and 9, it is possible to reliably and precisely carry out the movement of the article to be conveyed in the working region, resulting in the improved workability. 17 WE CLAIM : 1. An overhead conveyor comprising of a carrier comprising at least one pair of front and rear trolleys engaging a travel rail, a longitudinal carrier frame connected to said trolleys extending in a longitudinal direction and having at its front and rear portions the front and rear engaging holes drilled in a lateral direction on said carrier side, and a lateral carrier frame fitted laterally to the front portion of said longitudinal carrier frame, a hanger comprising a hanger frame bearing a front plate with engaging holes on the hanger side drilled in a lateral direction at positions corresponding to said front engaging holes on the carrier side and a rear plate with engaging holes on the hanger side drilled in a lateral direction at positions corresponding to said rear engaging holes on the carrier side, and a hanger arm suspended from said hanger frame to bear articles to be conveyed, a hanger guiding rail installed under said travel rail to bear said hangers, a tow bar comprising a first link, of which front end pivotally connects said lateral carrier frame, capable of swinging round the lateral axis and extending to the rear over the rear end of said hanger frame, and a second link, of which rear end pivotally connects the rear end of said first link, capable of swinging round the lateral axis and of which front end pivotally connects the rear end of said hanger frame, capable of swinging round the lateral axis, a swing control means for said second link to control its forward swinging up to a predetermined angle, a swing control means for said first link to control its downward swinging up to a predetermined angle, or an enlargement control means for included angle to control the included angle between said first and second links up to a predetermined angle, and an engagement/release switching means which enables switching between the front engaged state where the front engagement pin engaging said front engagement hole on the carrier side is engaged with said front engagement hole on the hanger side and the front released state where the front engagement is released, and switching between the rear engaged state where the rear engagement pin engaging said rear engagement hole on the carrier side is engaged with said rear engagement hole on the hanger side and the rear released state where the rear engagement is released, wherein the height of articles to be conveyed which are supported by said hanger arm can be changed by said engagement/release switching means 18 which switches between said front and rear engaged states where said hanger moves with the carrier in a united form and said front and rear released states where said hanger supported by said hanger guiding rail moves in traction by said tow bar. The overhead conveyor according to Claim 1, wherein a predetermined angle of said second link forward swinging to be controlled by said swing control means for the second link, a predetermined angle of said first link downward swinging to be controlled by said swing control means for the first link, or a predetermined angle of included angle between the first and second links to be controlled by said enlargement control means for included angle can be set in such a manner that the relative positional relationship between the center of said front and rear trolleys in a longitudinal direction and the center of said front and rear hangers in a longitudinal direction is nearly equal between said front and rear engaged states and said front and rear released states. The overhead conveyor according to Claim 1 or 2, wherein said swing control means for the second link brings the front projection of the second link into abutment with said hanger frame. The overhead conveyor according to Claim 1, wherein said engaging pins move in a lateral direction in such a manner that said engagement/release switching means connects said engaging pins to a lateral swing link mounted in front of and behind said longitudinal carrier frame swinging in a lateral direction and that a cam follower mounted on said lateral swing link is engaged with a cam rail mounted on the conveying path to swing the lateral swing link by driving said cam rail in a lateral direction. The overhead conveyor according to Claim 1, wherein the positioning for mating said engaging pins with said engaging holes on the hanger side to perform switching from said released state to said engaged state is carried out by bringing a roller mounted on the pivot between the first and second links of said tow bar into abutment with the cam rail mounted on the conveying path. 19 6 The overhead conveyor according to Claim 1, wherein said articles to be conveyed are kept nearly horizontal in a sloped ascending section or a sloped descending section of said travel rail by installing a hanger guiding rail which supports said hangers to keep them nearly horizontal in such a manner that the overhead conveyor is switched to said front released state and rear engaged state in said sloped ascending section, while the overhead conveyor is switched to said front engaged state and rear released state in said sloped descending section. Dated this 11th day of October, 2006 HIRAL CHANDRAKANT JOSHI AGENT FOR NAKANISHI METAL WORKS CO., LTD. 20 ABSTRACT An overhead conveyor having carrier (2) connected to front and rear trolleys (4,4) engaging travel rail (R), hanger (3) capable of changing the state of its engagement with carrier (2) and the state of release of the engagement, tow bar (23) forming a Vertical swing three-joint link mechanism for connecting carrier (2) and hanger (3), and engagement/release switching means for switching between the engaged state and the released state, wherein the engagement/release switching means enables switching between the engaged state where hanger (3) moves with carrier (2) in a united form and the released state where hanger (3) is towed by tow bar (23) while being supported by hanger guiding rail (HR) provided under travel rail (R). The height of an article to be conveyed can be changed to a height suitable for the job. To, The Controller of Patents The Patent Office Mumbai. 21

Full Text

FORM 2
THE PATENT ACT 1970 (39 of 1970)
The Patents Rules, 2 003 COMPLETE SPECIFICATION
(See Section 10, and rule 13)
1. TITLE OF INVENTION OVERHEAD CONVEYOR

2. APPLICANT(S)
a) Name
b) Nationality
c) Address

:NAKANISHI METAL WORKS CO., LTD.
:JAPANESE Company
:3-3-5, TENMABASHI,
:KITA-KU, OSAKA-SHI,
OSAKA, 5308566
JAPAN

3. PREAMBLE TO THE DESCRIPTION

The following specification particularly describes the and the manner in which it is to be performed : -

invention

Specification
[Technical Field]
The present invention relates to an overhead conveyor which can be used to handle articles having different sizes and/or shapes to be conveyed on the same production line such as, for example, an assembly line of car bodies for various types of car, to convey said articles by a hanger suspended from a carrier capable of traveling on a travel rail.
[Background Art]
The overhead conveyor comprises a carrier with a roller rolling on a travel rail installed in a space above workers (in the vicinity of the factory ceiling, for example) and a hanger which is suspended from said carrier and equipped with article bearing unit laterally mounted on its lower part. Furthermore, said carrier is driven by a power-chain drive unit, a friction-roller drive unit or the like. When such an overhead conveyor as mentioned above is used on an assembly line of car bodies for various types of car, it is necessary to execute the conveyor such that the height of articles supported on said hanger may be appropriately changed depending on the job, thereby preventing workers from working with an abnormal working pose which could adversely affect their workability and safety.
Conventional overhead conveyors having such an aim as mentioned above have been already disclosed:
an overhead conveyor comprising a power-chain conveyor rail to movably guide a power-chain, a trolley rail installed underneath said power-chain conveyor rail extending parallel to the power-chain conveyor rail to movably guide a trolley being driven by said power-chain, a first hanger connected to said trolley, a second hanger equipped with a hanger arm connected to said first hanger via an expansion mechanism in a vertical direction (such as panta-graph mechanism, for example) and bearing an article to be conveyed, and a guiding rail installed underneath said trolley rail extending parallel to the trolley rail to guide said second hanger, wherein said guide rail comprises a stepped guide part at a position to lift up said second hanger and a sloped guide part connected to said step-guide part (refer to the Patent document 1, for example), or an overhead conveyor, wherein a support for an article to be conveyed is detachably provided on a moving body freely movable on a constant path by the support and guide of a rail device, a support-conveying path
2

positioned below said constant path and along the constant path is placed at a predetermined position on the constant path, a separation means for removing said support from the specified moving body and transferring it to said support-conveying path is positioned at the starting part of the support-conveying path, and a joining means for bringing the support of the support-conveying path into abutment with the moving body is positioned at the end part of the support-conveying path (refer to the Patent document 2, for example).
Furthermore, a related known art has disclosed a conveyor device which can keep conveying attachments (including frames, hangers and the like) horizontal both at a sloped section and a level section on an article-conveying path for conveying articles to different heights, wherein front and rear trolleys are suspended freely movable by the intervention of rollers from a rail constructed along a certain path, front and rear hangers are pivotally supported by and hanged down from the vicinity of the front and rear ends of a frame located at the lower side of said front and rear trolleys nearly parallel to their traveling direction, making the distance between at least one of the front and rear trolleys and said frame changeable, bringing the other trolley and the frame into a pivotal support state, enabling the frame to freely swing round the pivotal support portion in a vertical direction, mounting a roller at a position of the frame and installing a cam rail carrying said roller along a sloped section of said path (refer to the Patent document 3, for example).
[Patent document 1] Japan patent application No. H01-181615 [Patent document 2] Japan patent application No. 2003-306143 [Patent document 1] Japan utility model No. S42-1144
[Disclosure of the Invention] [Problems to be Solved by the Invention]
In said conventional overhead conveyor as per the Patent document 1, there are several problems: a) said first hanger (carrier) and said second hanger equipped with the hanger arm carrying said articles to be conveyed are connected vertically via said expansion mechanism, and it is thus necessary to install a guiding rail working both to prevent the second hanger from swinging and to guide its movement up and down over the overall length of the conveyor; b) the structure of the vertical expansion mechanism is complicated, and especially when a panta-graph mechanism is employed as a vertical expansion mechanism, it is necessary to fit a guiding device
3

slidably guiding one of the upper ends of the horizontal panta-graph mechanism to the first hanger and a guiding device slidably guiding the lower end immediately under one of the upper ends of the horizontal panta-graph mechanism to the second hanger, thereby causing its reliability to be lowered and its manufacturing costs to be increased.
In the structure as per the Patent document 2, said moving body (carrier) and said support part for articles to be conveyed are completely separated, and it is thus necessary to add a moving power assigning means to said separation means, said joining means and said separated support part, and the control for said separation and joining is complicated, thereby causing its reliability to be lowered and its manufacturing costs to be increased.
Furthermore, when the structure as per the Patent document 3 is utilized to make the height of said front and rear hangers changeable relative to the carrier (said front and rear trolleys) so that the height of articles supported by the hangers may be changed to be suitable for the job, the center of said carrier in a longitudinal direction (the center between the front and rear trolleys in a longitudinal direction) and the center of said front and rear hangers in a longitudinal direction are to be changed, depending on the height of the hangers relative to the carrier (the hangers move toward the carrier in a longitudinal direction). Such movement of the hangers in a longitudinal direction is remarkable, especially in the case that the difference in height between the carrier and hangers increases. Thus, there exists a problem that an article conveyed by a certain carrier and hanger might occasionally collide or have contact with another article conveyed by another carrier and hanger preceding or following said ones. Furthermore, the problem of decreased productivity will also occur when the distance between articles to be conveyed is made bigger to avoid that collision or contact as mentioned above.
The present invention has been completed to solve the above-mentioned problems and aims to provide an overhead conveyor which is of simple structure but can reliably change the height of articles to be conveyed when they are supported by said hangers, so that their height will be appropriate for each job, and to improve the workability and reliability in addition to decreasing manufacturing costs. It can further control the movement of the articles in a longitudinal direction even when the differences in height of the carrier and hangers increase, so that collision and/ or contact between articles to be conveyed may be substantially avoided.
4

[Means to Solve the Problems]
To solve said problems, an overhead conveyor according to the present invention consists of a carrier comprising at least one pair of front and rear trolleys engaging a travel rail, a longitudinal carrier frame connected to said trolleys extending in a longitudinal direction and having at its front and rear portions the front and rear engaging holes drilled in a lateral direction on said carrier side, and a lateral carrier frame fitted laterally to the front portion of said longitudinal carrier frame, a hanger comprising a hanger frame bearing a front plate with engaging holes on the hanger side drilled in a lateral direction at positions corresponding to said front engaging holes on the carrier side and a rear plate with engaging holes on the hanger side drilled in a lateral direction at positions corresponding to said rear engaging holes on the carrier side, and a hanger arm suspended from said hanger frame to bear articles to be conveyed, a hanger guiding rail installed under said travel rail to bear said hangers, a tow bar comprising a first link, of which front end pivotally touches said lateral carrier frame, capable of swinging round the lateral axis and extending to the rear over the rear end of said hanger frame, and a second link, of which rear end pivotally touches the rear end of said first link, capable of swinging round the lateral axis and of which front end pivotally touches the rear end of said hanger frame, capable of swinging round the lateral axis, a swing control means for said second link to control its forward swinging up to a predetermined angle, a swing control means for said first link to control its downward swinging up to a predetermined angle, or an enlargement control means for included angle to control the included angle between said first and second links up to a predetermined angle, and an engagement/release switching means which enables switching between the front engaged state where the front engagement pin engaging said front engagement hole on the carrier side is engaged with said front engagement hole on the hanger side and the front released state where the front engagement is released, and switching between the rear engaged state where the rear engagement pin engaging said rear engagement hole on the carrier side is engaged with said rear engagement hole on the hanger side and the rear released state where the rear engagement is released, wherein the height of articles to be conveyed which are supported by said hanger arm can be changed by said engagement/release switching means which switches between said front and rear engaged states where said hanger moves with the carrier in a united form and said front and rear released states where said hanger supported by said hanger guiding rail moves in traction by said tow bar.
It is preferable to provide an overhead conveyor, wherein a predetermined angle of
5

said second link forward swinging to be controlled by said swing control means for the second link, a predetermined angle of said first link downward swinging to be controlled by said swing control means for the first link, or a predetermined angle of included angle between the first and second links to be controlled by said enlargement control means for included angle can be set in such a manner that the relative positional relationship between the center of said front and rear trolleys in a longitudinal direction and the center of said front and rear hangers in a longitudinal direction is nearly equal between said front and rear engaged states and said front and rear released states.
It is preferable that said swing control means for the second link brings the front projection of the second link into abutment with said hanger frame.
It is further preferable that said engaging pins move in a lateral direction in such a manner that said engagement/release switching means connects said engaging pins to a lateral swing link mounted in front of and behind said longitudinal carrier frame swinging in a lateral direction and that a cam follower mounted on said lateral swing link is engaged with a cam rail mounted on the conveying path to swing the lateral swing link by driving said cam rail in a lateral direction.
It is further preferable that the positioning for mating said engaging pins with said engaging holes on the hanger side to perform switching from said released state to said engaged state is carried out by bringing a roller mounted on the pivot between the first and second links of said tow bar into contact with the cam rail mounted on the conveying path.
It is preferable that said articles to be conveyed are kept nearly horizontal in a sloped ascending section or a sloped descending section of said travel rail by installing a hanger guiding rail which supports said hangers to keep them nearly horizontal in such a manner that the overhead conveyor is switched to said front released state and rear engaged state in said sloped ascending section, while the overhead conveyor is switched to said front engaged state and rear released state in said sloped descending section.
[Effect of the Invention]
The overhead conveyor according to the present invention consists of a carrier
comprising at least one pair of front and rear trolleys engaging a travel rail, a
6

longitudinal carrier frame connected to said trolleys extending in a longitudina direction and having at its front and rear portions the front and rear engaging hole! drilled in a lateral direction on said carrier side, and a lateral carrier frame fitted laterally to the front portion of said longitudinal carrier frame, a hanger comprising £ hanger frame bearing a front plate with engaging holes on the hanger side drilled in £ lateral direction at positions corresponding to said front engaging holes on the carried side and a rear plate with engaging holes on the hanger side drilled in a lateral direction at positions corresponding to said rear engaging holes on the carrier side, and a hanger arm suspended from said hanger frame to bear articles to be conveyed, a hanger guiding rail installed under said travel rail to bear said hangers, a tow bail comprising a first link, of which front end pivotally touches said lateral carrier frame; capable of swinging round the lateral axis and extending to the rear over the rear end of said hanger frame, and a second link, of which rear end pivotally touches the real end of said first link, capable of swinging round the lateral axis and of which front end pivotally touches the rear end of said hanger frame, capable of swinging round the lateral axis, a swing control means for said second link to control its forward swinging up to a predetermined angle, a swing control means for said first link to control its downward swinging up to a predetermined angle, or an enlargement control means for included angle to control the included angle between said first and second links up to a predetermined angle, and an engagement/release switching means which enables switching between the front engaged state where the front engagement pin engaging said front engagement hole on the carrier side is engaged with said front engagement hole on the hanger side and the front released state where the front engagement is released, and switching between the rear engaged state where the rear engagement pin engaging said rear engagement hole on the carrier side is engaged with said rear engagement hole on the hanger side and the rear released state where the rear engagement is released, wherein the height of articles to be conveyed which are supported by said hanger arm can be changed by said engagement/release switching means which switches between said front and rear engaged states where said hanger moves with the carrier in a united form and said front and rear released states where said hanger supported by said hanger guiding rail moves in traction by said tow bar, and thus, the height of articles to be conveyed can be reliably changed to that suitable for the job, although the system is of simple structure, and improved workability and reliability can be realized, in addition to achieving the reduction of manufacturing costs. Furthermore, it is possible to control the forward or backward movement of the articles to be conveyed even when the differences in height of the carrier and hangers increase, and collision and/or contact between the articles to be
7

conveyed may be substantially avoided.
A predetermined angle of said second link forward swinging to be controlled by said swing control means for the second link, a predetermined angle of said first link downward swinging to be controlled by said swing control means for the first link, or a predetermined angle of included angle between the first and second links to be controlled by said enlargement control means for included angle can be set in such a manner that the relative positional relationship between the center of said front and rear trolleys in a longitudinal direction and the center of said front and rear hangers in a longitudinal direction is nearly equal between said front and rear engaged states and said front and rear released states, and thus collision and/or contact between the articles to be conveyed may be more reliably avoided.
According to the overhead conveyor of the present invention, said swing control means for the second link brings the front projection of the second link into abutment with said hanger frame, and it is thus possible to control more easily collision and/or contact between the articles to be conveyed.
Furthermore, according to the overhead conveyor of the present invention, said engaging pins move in a lateral direction in such a manner that said engagement/release switching means connects said engaging pins to a lateral swing link mounted in front of and behind said longitudinal carrier frame swinging in a lateral direction and that a cam follower mounted on said lateral swing link is engaged with a cam rail mounted on the conveying path to swing the lateral swing link by driving said cam rail in a lateral direction, and it is thus possible to provide said engagement/release switching means which can conduct said engagement and release easily and reliably without installing drive means on said carriers and hanger.
In the overhead conveyor according to the present invention, positioning for mating said engaging pins with said engaging holes on the hanger side to perform switching from said released state to said engaged state is carried out by bringing a roller mounted on the pivot between the first and second links of said tow bar into contact with the cam rail mounted on the conveying path, and it is thus possible to conduct the positioning between said engaging pin and said engaging holes easily and reliably.
In the overhead conveyor according to the present invention, said articles to be
8

conveyed are kept nearly horizontal in a sloped ascending section or a sloped descending section of said travel rail by installing a hanger guiding rail which supports said hangers to keep them nearly horizontal in such a manner that the overhead conveyor is switched to said front released state and rear engaged state in said sloped ascending section, while the overhead conveyor is switched to said front engaged state and rear released state in said sloped descending section, and thus the hanger is not inclined even when said carrier moves in inclined pose in said sloped section and it is possible to prevent the articles from dropping out of the hanger.
[Brief Explanation of the Drawings]
[Fig. 1] is a right side view showing the overhead conveyor according to an
embodiment of the present invention.
[Fig. 2] is a plan view showing the bottom of a trolley of the overhead conveyor
according to an embodiment of the present invention.
[Fig. 3] is a rear view showing the overhead conveyor according to an embodiment of
the present invention.
[Fig. 4] is a rear view to explain the engagement/release switching means: (a) is a view
to explain its operation, and (b) is an enlarged view to show an engaged state between
an engaging pin and an engaging hole on the hanger side.
[Fig. 5] is a view to explain the operation which enables the height of an article
supported by the hanger arm to be changed.
[Fig. 6] is a view to explain the operation which enables the height of an article
supported by the hanger arm to be changed.
[Fig. 7] is a view to explain a positioning cam rail installed on the conveying path.
[Fig. 8] is a rear view showing a state where an article to be conveyed is brought to a
height suitable for the job (higher position of the article).
[Fig. 9] is a rear view showing a state where an article to be conveyed is brought to a
height suitable for the job (lower position of the article).
[Best Embodiment to Carry out the Invention]
An embodiment of the present invention is explained in detail hereinafter according to the attached drawings, and the present invention should not be limited only to the embodiment shown in said drawings, but should include all the embodiments satisfying the requirement described in the claims. As per the specification of the present invention, it should be noted that the direction toward which the carrier advances along the travel rail means "front" (refer to "arrow A" in the drawings)
9

while the opposite direction means "rear", and "right and left" sides means those when man looks at the carrier from front toward rear.
Figs. 1 to 3 are explanatory views showing an embodiment of the overhead conveyor according to the present invention: Fig. 1 is a right side view, Fig. 2 is a plan view showing the bottom of a trolley and Fig. 3 is a rear view (seen from the rear). In Fig. 3, the trolley engaged with rail R is load-trolley 4. The overhead conveyor 1 consists of carrier 2 capable of running along the travel rail R, hanger 3 suspended from the carrier 2 to bear article W1 or W2 to be conveyed, etc.
Carrier 2 comprises front and rear load-trolleys 4, 4, leading trolley 5, tail-trolley 6, expansible drive rod 7 connecting front and rear load-trolleys 4, 4, connecting rod 8 connecting front load-trolley 4 and leading trolley 5, connecting rod 9 connecting rear load-trolley 4 and tail-trolley 6, longitudinal carrier frames 10, 10 installed between front and rear load-trolleys 4, 4, longitudinally extending, and at their front and rear parts front engaging hole 10a on the carrier side and rear engaging hole 10b on the carrier side are drilled in a lateral direction, and lateral carrier frame 11 installed in a lateral direction at the front parts of said longitudinal carrier frames 10,10.
The front and rear load-trolleys 4,4 have a vertical roller 4a rolling on the travel rail R that is a nearly I-formed mono-rail, for example, and capable of rotating round the lateral axis, and horizontal rollers 4b, 4b capable of rotating round the vertical axis, and engage the travel rail R. The leading trolley 5 has a vertical roller 5a rolling on the travel rail R and capable of rotating round the lateral axis and horizontal rollers 5b, 5b capable of rotating round the vertical axis, and engages the travel rail R. The tail-trolley 6 has a vertical roller 6a rolling on the travel rail R and capable of rotating round the lateral axis, and horizontal rollers 6b, 6b capable of rotating round the vertical axis, and engages the travel rail R.
On the right and left sides of the front and rear load-trolleys 4, 4, leading trolley 5, tail-trolley 6, drive rod 7 and connecting rods 8,9, a nearly vertical face is built, which a friction roller (not shown) installed on the conveying path touches laterally, and the driving power of said friction roller gives the carrier 2 a thrust force, so that the carrier 2 can run along the travel rail R.
The hanger 3 comprises front right/left and rear right/left frames 13 to 16, right and left support members 17, 17 projected onto the rear part of said frame 14, a hanger
10

frame 12 bearing a front plate 18 with a front engaging hole 18a laterally projected at a position corresponding to said front engaging hole 10a on the carrier side and a rear plate 19 with a rear engaging hole 19a laterally projected at a position corresponding to said rear engaging hole 10b on the carrier side, and hanger arms 20, 20 suspended from said hanger frame 12 and bearing an article W1 or W2 to be conveyed.
The carrier 2 and the hanger 3 are connected by a first link 21 of which front end 21a pivotally connects the lateral carrier frame 11 so as to he capable of swinging round the lateral axis, and which extends backwards over the rear end of the hanger frame 12, that is, the rear end of the support members 17 projected onto the rear part of the rear frame 14, and a second link 22 of which rear end 22b pivotally connects the rear end 21b of the first link 21 so as to be capable of swinging round the lateral axis, and of which front end 22a pivotally connects the rear end of said hanger frame 12 so as to be capable of swinging round the lateral axis. The first link 21 and second link 22 structured as mentioned above form tow bars 23,23 which are located on the right and left sides and are a vertically swinging three-joint link mechanism. The forward swing of the second link 22 is controlled in such a manner that front protrusion 24 forming second link swing control means (to be explained below) touches the upper face of the hanger frame 12 (upper frame of the support member 17 projected onto the rear part of the rear frame 14).
Fig. 4 is a rear view to explain an engagement/release switching means 26 (view seen from rear) which can perform switching from the front engaged state where a front engaging pin 25a engaged with a front engaging hole 10a on the carrier side is engaged with a front engaging hole 18a on the hanger side to the front released state where said engagement is released, and the rear engaged state where a rear engaging pin 25b engaged with a rear engaging hole 10b on the carrier side is engaged with a rear engaging hole 19a on the hanger side to the rear released state where said engagement is released, and vice versa. Fig. 4(a) is a view to explain its operation, and Fig. 4(b) is an enlarged view to show the engaged state between the front engaging pin 25a and the front engaging hole 18a on the hanger side. Fig. 4 shows an engagement/release switching means on the front side, that is, a switching means which switches from the front engaged state where the front engaging pin 25a engaged with the front engaging hole 10a on the carrier side is engaged with the front engaging hole 18a on the hanger side to the front released state where said front engagement is released, and an engagement/release switching means on the rear side, that is, a switching means which switches from the rear engaged state where a rear
11

engaging pin 25b engaged with a rear engaging hole 10b on the carrier side is engaged with a rear engaging hole 19a on the hanger side to the rear released state where said engagement is released, is of similar structure to said means.
Said front engaging pin 25a is connected to lateral swing link 27 of near L-form laterally swinging, attached pivotally to bracket 29 fixed to the front part of the longitudinal carrier frame l0 so as to be capable of swinging round a longitudinal axis 29a, and a cam follower 28 is mounted on the upper end of the link. At a predetermined position on the conveying path a cam rail 30 is installed, which has an engaging portion 30a engaging with said cam follower 28 and is capable of swinging round the longitudinal axis 30b, and the upper end 30c of the cam rail 30 is connected to a rod 31a of an air cylinder 31. When the air cylinder 31 is thus driven to move the rod 31a back and forth in the engagement state of the cam follower 28 of lateral swing link 27 of near L-form with an engaging part 30a of the cam rail 30 at a predetermined position of the conveying path, the cam rail 30 swings round the longitudinal axis 30b, the lateral swing link 27 swings in a lateral direction and the front engaging pin 25a also moves in a lateral direction.
As a result, extending the rod of the air cylinder 31 makes it possible to realize the front engaged state where the front engaging pin 25a is engaged with the front engaging hole 18a on the hanger side as per the two-dot chain line in Fig. 4, and retreating the rod of the air cylinder 31 makes it possible to realize the front released state where the front engaging pin 25a is pulled out of the front engaging hole 18a on the hanger side as per the solid line in Fig. 4. By a similar structure and operation, said rear engaged state and rear released state may be also realized. By using that structure, it is possible to provide said engagement/release switching means 26 that is able to perform said engagement and release easily and reliably without the need to install any extra drive means.
The front engaging pin 25a is structured such that the outer diameter of its tip is bigger than the outer diameter of the part bearing the front plate 18 (for example, the outer diameter d0 in Fig. 4(b) is approx. 50mm, and the outer diameter dl is approx. 40mm). When the front engaging pin 25a is thus going to move from the front engaging hole 18a on the hanger side to the disengaging direction in the front engaged state, that is, in the state where the front plate 18 is born by the front engaging pin 25a, the tip (part of the outer diameter d0) of the front engaging pin 25a touches the side face of the front plate 18, so that it is possible to hold the front engaging pin 25a to be
12

pulled out of the front engaging hole 18a on the hanger side. In addition, a pressure coil spring 32 is interposed between a lower end 27a of the lateral swing link 27 of nearly L-form and the bottom of the lateral carrier frame 10 and the front engaging pin 25a is biased by a restoring force of said spring toward the front engaging hole 18a on the hanger side, so that it is possible to avoid an accident that the engagement of the front engaging pin 25a with the front engaging hole 18a on the hanger side is suddenly released and the hanger 3 falls from the carrier 2.
Figs. 5 and 6 are a view to explain the operation which enables the height of an article supported by said hanger arm to be changed using a switching function enabling the switching between the engaged state and released state by said engagement/release switch means. Fig. 5 shows a case in which the hanger guiding rail HR branches to the high hanger guiding rail HRH and the low hanger guiding rail HRL, and Fig. 6 shows a case in which the high hanger guiding rail HRH and low hanger guiding rail HRL join the hanger guiding rail HR.
The state at the position B in Fig. 5 shows a state where, as said front engagement and rear engagement state, vertical rollers 33, 33 which can rotate round lateral axes mounted in front of and behind right and a left frames 15,16 of the hanger frame 12 (refer to Figs. 2 and 3) are engaged with the hanger guiding rail HR by said engagement/release switch means. It is possible to change the system from this state to said front released state and rear released state by said engagement/ release switch means, so that the state of the position C in Fig. 5, that is, the state where said vertical rollers 33, 33 are engaged with the low hanger guiding rail HRL and the hanger 3 is trailed by the tow bar 23 to travel is realized.
In this case, to engage said vertical rollers 33, 33 with the high hanger guiding rail HRH in the state of said position C, the system should run from the position B in said front engaged and rear engaged state and a horizontal projection above the hanger guiding rail HR (refer to Fig. 3) should be removed at a position in front of the branch part of the hanger guiding rail HR (refer to "L" in Fig. 5) so as to make the section of the hanger guiding rail HR to be a nearly L-form. In such a way, at the position C, for example, the height of the hanger and an article to be conveyed (e.g. W2) which the hanger bears can be changed easily and reliably. Thus, the height of articles to be conveyed can be changed easily and reliably to that suitable for the job so as to avoid such a situation that workers have to work, standing on the floor FL with an unsuitable pose, resulting in reduced workability and safety, so that improvement in
13

workability and reliability can be realized, in addition to reduction of the manufacturing costs.
The hanger 3 is trailed by the carrier 2 via the tow bar 23 in both said front and rear released states, as the position C in Fig.5 shows, and it is thus possible to reduce the manufacturing costs without the need to install an extra means to drive the hanger 3.
The forward swing of the second link 22 in the state of C position in Fig. 5 is controlled by the structure to bring the front projection 24 of the second link 22, that is, the second link swing control means to limit the forward swing of the second link up to a predetermined angle, into abutment with the upper face of the hanger frame 12, that is, the upper face of the support member 17 projected onto the rear part of the rear frame 14. In that state where the forward swing of the second link 22 is controlled by the second link swing control means, a predetermined angle to control the forward swing of the second link is set, similarly as the position B in Fig. 5, so that the center between the front and rear load-trolleys 4, 4 in a longitudinal direction nearly conforms with the center of the hanger 3 in a longitudinal direction (refer to "CL" in Fig. 5). It should be also noted that the center between the front and rear load-trolleys 4, 4 in a longitudinal direction need not always conform with the center of the hanger 3 in a longitudinal direction, but said predetermined angle should be set such that the relative positional relationship of the center between the front and rear load-trolleys 4, 4 in a longitudinal direction with the center of the hanger 3 in a longitudinal direction in said front engaged and rear engaged states (e.g. state of the position B in Fig. 5) nearly conforms with that in said front released and rear released states (e.g. state of the position C in Fig. 5).
It is thus possible by that simple structure to control the movement of the articles to be conveyed in a longitudinal direction even when the differences in height of the carrier 2 and hangers 3 increase by the change of height of the articles, and collision and/or contact between the articles to be conveyed may be substantially avoided.
Instead of using said second link swing control means, it may be allowed to employ a first link swing control means to limit the downward swing of the first link 21 up to a predetermined angle. Said first link swing control means can be formed by providing a control plate 41 on the bottom of the lateral carrier frame 11 (refer to the position C in Fig. 5). In the case of employing that first link swing control means, it is possible to control the movement of the articles to be conveyed in a longitudinal
14

direction even when the differences in height of the carrier 2 and hangers 3 increase by the change of height of the articles, and collision and/or contact between the articles to be conveyed may be substantially avoided, by setting a predetermined angle for the downward swing of the first link such that the relative positional relationship of the center between the front and rear load-trolleys 4,4 in a longitudinal direction with the center of the hanger 3 in a longitudinal direction is nearly equal regardless of the differences in height of the articles to be conveyed.
Instead of using said second link swing control means or first link swing control means, it may be also allowed to employ an included angle enlargement control means to limit the included angle between the first link 21 and the second link 22 up to a predetermined angle (refer to the angle a in Fig. 5). Said included angle enlargement control means can be formed by fitting a stopper on or in the vicinity of the pivot axis for the rear end 21b of the first link 21 and the rear end 22b of the second link 22 to limit the included angle between the first link 21 and the second link 22 up to a predetermined angle. In the case of employing that included angle enlargement control means, it is possible to control the forward or backward movement of the articles to be conveyed even when the differences in height of the carrier 2 and hangers 3 increase by the change of height of the articles, and collision and/ or contact between the articles to be conveyed may be substantially avoided, by setting a predetermined angle for the included angle (refer to the anglea in Fig. 5) such that the relative positional relationship of the center between the front and rear load-trolleys 4, 4 in a longitudinal direction with the center of the hanger 3 in a longitudinal direction is nearly equal regardless of the differences in height of the articles to be conveyed.
The positions D and E in Fig. 6 show said front and rear released states and the positions F and G in Fig. 6 show said front and rear engaged states. When said front and rear released states of the position E changes into said front and rear engaged states of the position F, positioning between the engaging pins and engaging holes can be obtained easily and reliably by setting the distance between the travel rail R and the hanger guiding rail HR so that the front engaging pin 25a mates with the front engaging hole 18a on the hanger side and the rear engaging pin 25b mates with the rear engaging hole 19a on the hanger side after the low hanger guiding rail HRL joins the high hanger guiding rail HRH from a state where said vertical rollers 33,33 of the hanger frame 12 are engaged with the low hanger guiding rail HRL, and by bringing the rollers 36,36 mounted on the pivot axis between the rear end 21b of the first link 21 and the rear end 22b of the second link 22 forming said tow bar 23 (refer to Figs. 2 and
15

3) into abutment with the positioning cam rail 38 installed on the conveying path shown in Fig. 7. After completing said positioning, it is possible to bring the system into said front and rear engaged states easily and reliably by the engagement/release switch means 26 shown in Fig. 4.
The fit between the front engaging pin 25a and the front engaging hole 18a on the hanger side as well as between the rear engaging pin 25b and the rear engaging hole 19a on the hanger side is formed as clearance fit with an increased clearance. For example, d0 and dl in Fig. 4 (b) are approx. 50mm and 40mm, respectively, whereas the inner diameter Dl of the front engaging hole 18a on the hanger side is in the range of 60 to 70mm. Thus, it is possible to carry out both the engagement between the front engaging pin 25a and the front engaging hole 18a on the hanger side and the separation (release of said engagement) more easily and reliably. For example, even when some error exists in the distance between the travel rail R and the hanger guiding rail HR or in the fitting position of the cam rail 38 for positioning, it is possible owing to said clearance to reliably perform the change into said front and rear engaged states. Furthermore, it is possible owing to said clearance to use the overhead conveyor 1 totally over a long period by replacing only said worn out rails or the like as an exhaustion, when the rail R, rollers 4a, 4b of the trolley 4 or the hanger guiding rail HR etc. are worn out.
It is also possible to keep articles to be conveyed nearly horizontal by installing the hanger guiding rail HR bearing said vertical rollers 33,33 to keep the hanger 3 (articles to be conveyed) nearly horizontal, while the system is brought into the front released state and the rear engaged state in the ascending section of the travel rail R by the engagement/release switch means, and the system is brought into the front engaged state and the rear released state in the descending section of the travel rail R by the engagement/release switch means. Thus, the hanger 3 is not inclined even when said carrier moves with inclined pose in said sloped section and it is possible to prevent the articles from dropping out of the hanger 3.
It may be also allowed to employ a scheme in which only the travel rail R is used, disposing the hanger guiding rail HR, and the system is brought into only the front and rear engaged states in a non-working region exclusively for transport, and the switching between the engagement and release is conducted by the engagement/release switch means in a working region where the hanger guiding rail HR is installed.
16

Figs. 8 and 9 are a rear view showing a state where an article to be conveyed is brought to a height suitable for the job (seen from the rear). A trolley engaging the rail R in Figs. 8 and 9 shows the load-trolley 4. Fig. 8 shows the front and rear engaged states brought by the engagement/release switch means, where the position of the article Wl to be conveyed is comparatively high and suitable for the case when a worker standing on the floor FL, for example, attaches a part to the bottom of the article Wl. And Fig. 9 shows the front and rear released states brought by the engagement/release switch means, where the position of the article W1 to be conveyed is comparatively low and suitable for the case when a worker standing on the floor FL, for example, attaches a part to the side of the article W1.
The engaged state and released states can be easily switched by the engagement/release switch means as explained above, and it is thus possible to easily change the height of the article to be conveyed depending on the size of the article (refer to the articles W1, W2, for example, in Fig. 1) or depending on the position where any work on the article to be conveyed is carried out, by controlling the height of the hanger guiding rail HR after the vertical rollers 33,33 capable of rotating round the lateral axes interposed in front of and behind the left and right frames 15,16 of the hanger frame 12 are engaged with the hanger guiding rail HR. Thus, the height of articles to be conveyed can be reliably changed to that suitable for the job, though it is of simple structure, so that improved workability and reliability can be realized, in addition to the reduction of the manufacturing costs.
Lateral anti-swing rollers 34,34, guiding rail (such as hanger guiding rail HR), vertical anti-swing rollers 35, 35 and guiding rails 37, 37 are installed in the working region shown in Figs. 8 and 9, by which the reduced workability due to swinging of the article to be conveyed in the working region can be prevented. When engaging dog 40 mounted on the lateral carrier frame 11 of the carrier 2 is engaged with the roller-chain type drive unit 39 installed in the working region shown in Figs. 8 and 9, it is possible to reliably and precisely carry out the movement of the article to be conveyed in the working region, resulting in the improved workability.
17

WE CLAIM :
1. An overhead conveyor comprising of
a carrier comprising at least one pair of front and rear trolleys engaging a travel rail, a longitudinal carrier frame connected to said trolleys extending in a longitudinal direction and having at its front and rear portions the front and rear engaging holes drilled in a lateral direction on said carrier side, and a lateral carrier frame fitted laterally to the front portion of said longitudinal carrier frame,
a hanger comprising a hanger frame bearing a front plate with engaging holes on the hanger side drilled in a lateral direction at positions corresponding to said front engaging holes on the carrier side and a rear plate with engaging holes on the hanger side drilled in a lateral direction at positions corresponding to said rear engaging holes on the carrier side, and a hanger arm suspended from said hanger frame to bear articles to be conveyed, a hanger guiding rail installed under said travel rail to bear said hangers, a tow bar comprising a first link, of which front end pivotally connects said lateral carrier frame, capable of swinging round the lateral axis and extending to the rear over the rear end of said hanger frame, and a second link, of which rear end pivotally connects the rear end of said first link, capable of swinging round the lateral axis and of which front end pivotally connects the rear end of said hanger frame, capable of swinging round the lateral axis, a swing control means for said second link to control its forward swinging up to a predetermined angle, a swing control means for said first link to control its downward swinging up to a predetermined angle, or an enlargement control means for included angle to control the included angle between said first and second links up to a predetermined angle, and an engagement/release switching means which enables switching between the front engaged state where the front engagement pin engaging said front engagement hole on the carrier side is engaged with said front engagement hole on the hanger side and the front released state where the front engagement is released, and switching between the rear engaged state where the rear engagement pin engaging said rear engagement hole on the carrier side is engaged with said rear engagement hole on the hanger side and the rear released state where the rear engagement is released, wherein the height of articles to be conveyed which are supported by said hanger arm can be changed by said engagement/release switching means
18

which switches between said front and rear engaged states where said hanger moves with the carrier in a united form and said front and rear released states where said hanger supported by said hanger guiding rail moves in traction by said tow bar.
The overhead conveyor according to Claim 1,
wherein a predetermined angle of said second link forward swinging to be controlled by said swing control means for the second link, a predetermined angle of said first link downward swinging to be controlled by said swing control means for the first link, or a predetermined angle of included angle between the first and second links to be controlled by said enlargement control means for included angle can be set in such a manner that the relative positional relationship between the center of said front and rear trolleys in a longitudinal direction and the center of said front and rear hangers in a longitudinal direction is nearly equal between said front and rear engaged states and said front and rear released states.
The overhead conveyor according to Claim 1 or 2,
wherein said swing control means for the second link brings the front
projection of the second link into abutment with said hanger frame.
The overhead conveyor according to Claim 1,
wherein said engaging pins move in a lateral direction in such a manner that said engagement/release switching means connects said engaging pins to a lateral swing link mounted in front of and behind said longitudinal carrier frame swinging in a lateral direction and that a cam follower mounted on said lateral swing link is engaged with a cam rail mounted on the conveying path to swing the lateral swing link by driving said cam rail in a lateral direction.
The overhead conveyor according to Claim 1,
wherein the positioning for mating said engaging pins with said engaging holes on the hanger side to perform switching from said released state to said engaged state is carried out by bringing a roller mounted on the pivot between the first and second links of said tow bar into abutment with the cam rail mounted on the conveying path.
19

6 The overhead conveyor according to Claim 1,
wherein said articles to be conveyed are kept nearly horizontal in a sloped ascending section or a sloped descending section of said travel rail by installing a hanger guiding rail which supports said hangers to keep them nearly horizontal in such a manner that the overhead conveyor is switched to said front released state and rear engaged state in said sloped ascending section, while the overhead conveyor is switched to said front engaged state and rear released state in said sloped descending section.
Dated this 11th day of October, 2006

HIRAL CHANDRAKANT JOSHI
AGENT FOR
NAKANISHI METAL WORKS CO., LTD.
20

ABSTRACT
An overhead conveyor having carrier (2) connected to front and rear trolleys (4,4) engaging travel rail (R), hanger (3) capable of changing the state of its engagement with carrier (2) and the state of release of the engagement, tow bar (23) forming a Vertical swing three-joint link mechanism for connecting carrier (2) and hanger (3), and engagement/release switching means for switching between the engaged state and the released state, wherein the engagement/release switching means enables switching between the engaged state where hanger (3) moves with carrier (2) in a united form and the released state where hanger (3) is towed by tow bar (23) while being supported by hanger guiding rail (HR) provided under travel rail (R). The height of an article to be conveyed can be changed to a height suitable for the job.
To,
The Controller of Patents
The Patent Office
Mumbai.
21

Documents:

1223-mumnp-2006-abstract(19-8-2008).doc

1223-mumnp-2006-abstract(19-8-2008).pdf

1223-mumnp-2006-abstract.doc

1223-mumnp-2006-abstract.pdf

1223-mumnp-2006-cancelled pages(19-8-2008).pdf

1223-MUMNP-2006-CERTIFICATE(19-8-2008).pdf

1223-MUMNP-2006-CLAIMS(19-8-2008).pdf

1223-mumnp-2006-claims(granted)-(19-8-2008).doc

1223-mumnp-2006-claims(granted)-(19-8-2008).pdf

1223-mumnp-2006-claims.doc

1223-mumnp-2006-claims.pdf

1223-mumnp-2006-correspondence(19-8-2008).pdf

1223-mumnp-2006-correspondence(ipo)-(24-12-2008).pdf

1223-mumnp-2006-correspondence-others.pdf

1223-mumnp-2006-correspondence-received.pdf

1223-mumnp-2006-description (complete).pdf

1223-MUMNP-2006-DESCRIPTION(COMPLETE)-(19-8-2008).pdf

1223-mumnp-2006-drawing(19-8-2008).pdf

1223-mumnp-2006-drawing(19-8-2008).tif

1223-mumnp-2006-drawings.pdf

1223-MUMNP-2006-FORM 1(19-8-2008).pdf

1223-MUMNP-2006-FORM 18(19-8-2008).pdf

1223-mumnp-2006-form 2(19-8-2008).pdf

1223-mumnp-2006-form 2(granted)-(19-8-2008).doc

1223-mumnp-2006-form 2(granted)-(19-8-2008).pdf

1223-mumnp-2006-form 3(15-9-2006).pdf

1223-MUMNP-2006-FORM 3(19-8-2008).pdf

1223-mumnp-2006-form 5(19-12-2006).pdf

1223-MUMNP-2006-FORM 5(19-8-2008).pdf

1223-mumnp-2006-form-1.pdf

1223-mumnp-2006-form-2.doc

1223-mumnp-2006-form-2.pdf

1223-mumnp-2006-form-3.pdf

1223-mumnp-2006-form-5.pdf

1223-mumnp-2006-form-pct-ib-304.pdf

1223-mumnp-2006-form-pct-ib-308.pdf

1223-mumnp-2006-form-pct-isa-210(19-8-2008).pdf

1223-mumnp-2006-other documents(19-8-2008).pdf

1223-MUMNP-2006-PCT-IB-373(19-8-2008).pdf

1223-MUMNP-2006-PCT-ISA-237(19-8-2008).pdf

1223-mumnp-2006-pct-search report.pdf

1223-mumnp-2006-power of attorney(19-1-2006).pdf

1223-mumnp-2006-power of attorney(19-6-2006).pdf

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Patent Number

227095

Indian Patent Application Number

1223/MUMNP/2006

PG Journal Number

10/2009

Publication Date

06-Mar-2009

Grant Date

01-Jan-2009

Date of Filing

12-Oct-2006

Name of Patentee

NAKANISHI METAL WORKS CO., LTD.

Applicant Address

3-3-5, TENMABASHI, KITA-KU, OSAKA-SHI, OSAKA, 5308566

Inventors:

#	Inventor's Name	Inventor's Address
1	SAEKI, YASUKI	C/O NAKANISHI METAL WORKS CO., LTD. 3-3-5, TENMABASHI, KITA-KU, OSAKA-SHI, OSAKA, 5308566
2	KOBAYASHI, YUKIHIKO	C/O DAIHATSU MOTOR CO., LTD., 1-1, MOMOZONO 2-CHOME, IKEDA-SHI, OSAKA, 5630045
3	FURUKAWA, TAKAYUKI	C/O DAIHATSU MOTOR CO., LTD., 1-1, MOMOZONO 2-CHOME, IKEDA-SHI, OSAKA, 5630045

PCT International Classification Number

B61B10/02,B23P19/00

PCT International Application Number

PCT/JP05/004545

PCT International Filing date

2005-03-15

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2004-081141	2004-03-19	Japan