Title of Invention	A SPINNING MACHINE
Abstract	The present invention relates to a spinning machine comprising a fiber bundle collecting device which is provided on a downstream side of a final delivery roller pair of a drafting part and collects a fiber bundle (F) drafted by the drafting part, characterized in that the fiber bundle collecting device comprises: a delivery portion provided with a nip roller; a suction portion (S) provided with a suction hole arranged so as to extend at least toward an upstream side of a nip point of the delivery portion with respect to a moving direction of the fiber bundle (F); an air-permeable member which constitutes the delivery portion and is rotated along the suction portion (S); and suction means capable of arbitrarily setting and changing a suction pressure that acts on the suction portion (S).

Title of Invention

A SPINNING MACHINE

Abstract

The present invention relates to a spinning machine comprising a fiber bundle collecting device which is provided on a downstream side of a final delivery roller pair of a drafting part and collects a fiber bundle (F) drafted by the drafting part, characterized in that the fiber bundle collecting device comprises: a delivery portion provided with a nip roller; a suction portion (S) provided with a suction hole arranged so as to extend at least toward an upstream side of a nip point of the delivery portion with respect to a moving direction of the fiber bundle (F); an air-permeable member which constitutes the delivery portion and is rotated along the suction portion (S); and suction means capable of arbitrarily setting and changing a suction pressure that acts on the suction portion (S).

Full Text	SPINNING MACHINE AND SPINNING METHOD BACKGROUND OF THE INVENTION The present invention relates to a spinning machine and a spinning method, and more specifically relates to, for example, a spinning machine provided with a fiber bundle collecting device which is arranged downstream of a drafting device (drafting part) of a spinning frame and which collects a fiber bundle drafted by the drafting device and to a spinning method that uses the spinning machine. Up to now, fiber bundle collecting devices of such type generally utilize sucking action in collection of a fiber bundle (for example, refer to JP 11-286837 A and JP 2000-73224 A) . In each of the devices disclosed in Patent Documents 1 and 2 mentioned above, a hollow profile (guide cylinder) that constitutes a stationary sliding surface having a suction slit is provided on the bottom side downstream of a final roller of a drafting device, and a perforated belt for transfer is wound around the hollow profile. Further, a nip roller, which is held in contact with the perforated belt to define a nip point, is provided on the top side. The nip roller is driven through a conveying belt by means of the final roller. Instead of the structure in which the nip roller is driven through the conveying belt, also disclosed is a structure in which the nip roller is driven through a conveying roller held in contact with the final roller. Further, there is disclosed a fiber bundle collecting device with a structure different from that disclosed in Patent Document 1 mentioned above in that the perforated belt is wound between a hollow profile having a suction slit on its sliding surface and a tension roller (refer to JP 2000-34631 A). It is considered that, when thread is spun with a spinning machine provided with the above-mentioned fiber bundle collecting device, a suction pressure, which acts on the suction slit of the fiber bundle collecting device, affects quality of the thread to be spun. However, up to now, there have been found no document that describes about positively changing the suction pressure in accordance with spinning conditions to spin thread with appropriate quality. The inventors of the present invention have experimentally changed the suction pressure to examine quality of the spun thread. As a result, the followings have been found: in a region with a low suction pressure, the thread quality is significantly improved along with the rise of a negative pressure {increase of decompression degree); and the thread quality tends to stay flat after reaching a certain level or more, probably because of the fact that a fiber bundle is brought into a saturation state at that level. Further, it has been found that the level at which the pressure begins to stay flat differs depending on a thread size (count), fiber type. and spindle speed. The above-mentioned facts lead to the conclusion that it is important that a suction pressure of a certain level or more {hereinafter, referred to as a necessary pressure) be made to act on a fiber bundle in order to increase a collection degree of the fiber bundle through sucking action to thereby realize desired thread quality. However, when pressure setting of a suction device is fixed in correspondence with a spinning condition with a high necessary pressure from the viewpoint of safety, there is produced a result that energy such as power necessary for suction is needlessly consumed, with respect to a spinning condition with a low necessary pressure. Further, even granted that a suction device is constructed such that a suction pressure is changeable for each spinning condition in consideration of the above situation, there may arise a problem in that: an appropriate value cannot be determined easily even if a machine operator tries to perform pressure setting with no energy wastage; and it involves the trouble of finding the appropriate value based on the experimental spinning performed on several occasions for each change of the spinning condition. Further, it is known that the thread quality such as fluff is changed in accordance with the change of thread tension in a twisting/winding portion or the like generally in the thread wound around one full bobbin. Therefore, in order to obtain more uniform thread, it might be most appropriate to change the suction pressure. rather than keeping it at a constant level, from the start of winding (start of spinning) to the full bobbin stop. SURMMARY OF THE INVENTION The present invention has been made in view of the above problems, and therefore has a first object to provide a spinning machine that enables setting and change of a suction pressure of a fiber bundle collecting device to thereby make quality of spun thread fulfill a desired condition. Further, the present invention has a second object to provide a spinning method in which a fiber bundle collecting device is made to exert appropriate fiber bundle collecting action from the start to the end of winding to thereby spin thread with constant quality. In order to achieve the above-mentioned first object, the invention as described in claim 1 relates to a spinning machine in which a fiber bundle collecting device for collecting a fiber bundle drafted by a drafting part is provided on a downstream side of a final delivery roller pair of the drafting part. The fiber bundle collecting device is provided with: a delivery portion provided with a nip roller; a suction portion provided with a suction hole arranged so as to extend at least toward an upstream side of a nip point of the delivery portion with respect to a moving direction of the fiber bundle; an air-permeable member which constitutes the delivery portion and is rotated along the suction portion; and suction means capable of arbitrarily setting and changing a suction pressure that acts on the suction portion. According to the invention as described above, the fiber bundle drafted in the drafting part is collected by the fiber bundle collecting device provided on the downstream side of the final delivery roller pair of the drafting part, and is moved in a collected state• Thus, generation of fluff and waste cotton are suppressed, and a thread quality improving effect is significantly enhanced as compared with a spinning machine not provided with the fiber bundle collecting device. Collecting action of the fiber bundle collecting device is caused by sucking action of the suction hole of the suction portion to which a suction pressure is imparted by the suction means. Then, the suction means can arbitrarily set and change the suction pressure that acts on the suction portion, and therefore, spinning can be performed while changing the suction pressure to have the optimum value in accordance with a spinning condition. According to the invention as described in claim 2, in the invention according to claim 1, the suction means is driven such that the magnitude of the suction pressure is changed so as to satisfy the following relationship: large count > middle count > small count, in correspondence with the large count, middle count, and small count of spun thread. In the invention as described above, the suction pressure is changed to have an appropriate value in accordance with the thickness of the spun thread to perform spinning. As a result, the collecting action of the fiber bundle collecting device is appropriately performed in a state in which waste energy consumption is suppressed. According to the invention as described in claim 3, in the invention according to claim 1 or 2, the suction means is driven and controlled by control means such that the suction pressure is changeable, and the control means is structured such that the appropriate suction pressure can be automatically set in correspondence with a spinning condition. In the present invention, the spinning condition is set, whereby the appropriate suction pressure is automatically set in the control means in correspondence with the spinning condition. Then, when the spinning machine is operated, the suction means is driven and controlled by the control means such that the suction pressure of the suction portion becomes an appropriate pressure in correspondence with the spinning condition. According to the invention as described in claim4, in the invention according to any one of claims 1 to 3, the suction portion is provided with a suction pipe having the suction hole corresponding to each spindle, and the suction pipe is connected to a duct that is maintained at a negative pressure by plural suction devices. In the present invention, when one of the suction devices is stopped due to abnormality, the negative pressure generated by the rest of the suction devices can secure the sucking action of the suction hole. Thus, the quality of spun thread is maintained within a permissible range. According to the invention as described in claim 5, in the invention according to claim 4, the duct connected with the suction pipe is provided independently of a pneumatic duct. In the present invention, the duct can be maintained at a predetermined negative pressure without increasing the suction device in size. In order to achieve the second object, the invention as described in claim 6 relates to a spinning method that uses a spinning machine provided with a fiber bundle collecting device on a downstream side of a final delivery roller pair of a drafting part, the device being provided with: a delivery portion provided with a nip roller; a suction portion provided with a suction hole arranged so as to extend at least toward an upstream side of a nip point of the delivery portion with respect to a moving direction of a fiber bundle; an air-permeable member which constitutes the delivery portion and is rotated along the suction portion; and suction means capable of arbitrarily setting and changing a suction pressure that acts on the suction portion, and the device collecting the fiber bundle drafted by the drafting part. Then, spinning is performed while the suction pressure is adjusted so as to be at the maximum at the time when a winding amount of thread to a bobbin reaches approximately 30 percent of a full bobbin. According to the invention as described above, spinning is not performed such that the suction pressure of the fiber bundle collecting device is constant from the start to the end of winding of spun thread (that is, full bobbin) but performed such that sucking action of the suction hole is at the maximum at the time when the winding amount of thread to the bobbin reaches approximately 30 percent of the full bobbin. As a result, the quality of the spun thread is improved. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: Fig. 1 is a schematic plan view showing an arrangement of a suction device and a duct in accordance with an embodiment; Fig. 2 is a schematic side view, partly in section showing a drafting device and a fiber bundle collecting device; Fig. 3 is a partial schematic view showing a relationship between a suction portion and a bottom nip roller; ' Fig. 4A is a partial schematic view of a fiber bundle collecting device as seen from the front in a fiber bundle moving direction and Fig. 4B is a front view of a rotation shaft; Fig. 5 is partial enlarged view of Fig. 2; Fig. 6 is a partial perspective view of a connection pipe; Figs. 7A to 7F are each a graph showing a relationship between a suction pressure and hairiness or a relationship between a suction pressure and 0% in spinning of threads with different yarn counts; and Fig. 8 is graph showing a relationship between the number of fluffs and a winding amount in a general ring spinning frame. DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to Figs. 1 through 8. Fig. 1 is a schematic plan view showing a relationship among a duct of a fiber bundle collecting device, suction devices, and suction portions, and Fig. 2 is a schematic side view, partly in section, showing one side of a drafting device. Fig. 3 is a partial schematic view with the top roller side being omitted, showing a relationship among a bottom roller of a drafting device, and the suction portions and bottom nip rollers of the fiber bundle collecting device. Fig. 4A is a schematic view of the fiber bundle collecting device as seen in a fiber bundle-drawing-out direction at a nip point (as seen from the front side with respect to a fiber bundle moving direction in the drafting device). As shown in Fig. 2, a drafting device 11 as a draft part is of a three-line construction equipped with a front bottom roller 12, a middle bottom roller 13, and a back bottom roller 14. The front bottom roller 12 is supported at a predetermined position with respect to a roller stand 15, and the middle and back bottom rollers 13 and 14 are supported through the intermediation of support brackets 13a and 14a secured to the roller stand 15 so as to allow position adjustment in the longitudinal direction. The support brackets 13a and 14a are fastened to predetermined positions by means of bolts passed through an elongated hole formed in the roller stand 15 and nuts (all not shown). A bottom apron 16 is wrapped around a bottom tenser 17 and the middle bottom roller 13. Supported by a weighting arm 18 through the intermediation of top roller support members are a front top roller 19, a middle top roller 20, and a back top roller 21 at positions respectively corresponding to the front bottom roller 12, the middle bottom roller 13, and the back bottom roller 14. Each of the top rollers 19 through 21 is supported in a two-spindle unit. The front bottom roller 12 and the front top roller 19 constitute a pair of final delivery rollers of the drafting device 11. Arranged on the weighting arm 18 is a lever 18a so as to be rotatable to a pressurizing position and to a releasing position. In the condition in which the lever 18a is arranged at the pressurizing position where it abuts a frame 18b of the weighting arm 18 shown in Fig. 2, a lock state is maintained in which the top rollers 19 through 21 supported by the weighting arm 18 are in the pressurizing position (spinning position) in which they are pressurized toward the bottom rollers 12, 13, and 14. In the condition in which the lever 18a has been rotated from the condition shown in Fig. 2 to the upper, releasing position, the lock state is canceled. As shown in Fig. 2, a fiber bundle collecting device 30 is arranged on the downstream side of the pair of final delivery rollers of the drafting device 11. The fiber bundle collecting device 30 is equipped with a delivery portion 31, suction pipes 32 and 33 as a suction portion S, and an air-permeable apron 34 as an air-permeable member. The deliveryportion 31 is composed of a bottom nip roller 35a as a nip roller, which is formed on a rotation shaft 35 arranged parallel to the front bottom roller 12, and a top nip roller 31a as a nip roller, which is pressurized against the bottom nip roller 35a through the intermediation of the air-permeable apron 34. As shown in Fig. 4A, in the fiber bundle collecting device 30 of this embodiment, the top nip roller 31a is, like the top rollers 19 through 21 of the drafting device 11, supported every two spindles by the weighting arm 18 through the intermediation of a support member 36 (shown in Figs. 2 and 5). Note that, in this embodiment, the support member 36 is formed integrally with a support member of the front top roller 19. On the other hand, on the bottom side of the fiber bundle collecting device 30, half the spindles arranged between the roller stands 15 of the drafting device 11, i.e., four spindles in this embodiment, constitute one unit. As shown in Fig. 3, at the middle position of the roller stands 15 arranged at predetermined intervals in the longitudinal direction of a machine base, a support arm 38 is arranged in a state in which its base end is supported by a support beam 37 extending in the longitudinal direction of the machine base, and the rotation shaft 35 is supported between the roller stand 15 and the support arm 38. As shown in Fig. 4B, the rotation shaft 35 is formed in a predetermined length corresponding to a plurality of spindles (four spindles in this embodiment), and a bearing 39 is secured to either end thereof. Then, the bearings 39 are fitted into end plugs 40, and, as shown in Fig. 4A, the end plugs 40 are supported in the engagement portions 40a by support portions 15a and 38a provided on the roller stand 15 and the support arm 38, whereby the rotation shaft 35 is rotatably supported between the roller stand 15 and the support arm 38. The support portions 15a and 38a are formed so as to be capable of suppoi;ting two end plugs 40, and are capable of supporting the end plugs 40 which are mounted to the ends of the adjacent rotation shafts 35- The support portion 15a is formed by a block fixed to the roller stand 15, and has engagement recesses extending obliquely upwards on the front side of the machine base. The support portion 38a also has an engagement recess extending obliquely upwards on the front side of the machine base. Then, the end plug 40 has an engagement portion 40a capable of being engaged with both the engagement recesses, 'and is formed so as to be capable of being engaged, in a single snap motion, with the support portions 15a and 38a in the engagement portion 40a. The rotation shaft 35 has at its longitudinal center a gear 41 which is arranged so as to be capable of rotating integrally with the rotation shaft 35. As shown in Fig. 3, the front bottom roller 12 has a gear portion 12a formed at a position opposed to the gear 41. Further, an intermediate gear 43 in mesh with the gear portion 12a and the gear 41 is rotatably supported by a support arm 42 whose base end is fixed to the support beam 37 like the support arm 38. That is, the torque of the front bottom roller 12 is transmitted to the rotation shaft 35 by way of the gear portion 12a, the intermediate gear 43, and the gear 41. As shown in Figs. 1 and 2, in the machine base of the spinning frame, ducts 44 forthefiber bundle collecting device 30 are arranged so as to extend in a longitudinal direction thereof (in a direction perpendicular to the plane of Fig. 2). As shown in Fig. 1, a plurality of ducts 44 are provided so as to extend in the longitudinal direction of the machine base of the spinning frame. In this embodiment, the length of each duct 44 is such that it corresponds to 24 spindles on one side and 48 spindles on both sides. A plurality of (three in this embodiment) suction devices 45 for maintaining a negative pressure in each duct 44 are connected to each duct 44 through pipes 46. That is, in this embodiment, one suction device 45 is provided for one unit, which is composed of 16 spindles. The suction devices 45 are composed of fan motors in which fans 47a are driven by motors 47. As shown in Fig. 2, the ducts 44 are arranged on the upper rear side of the drafting device 11 and at the center of the machine base of the spinning machine, and the suction devices 45 are arranged below the ducts 44. The suction means is constructed by the ducts 44 and the suction devices 45. As shown in Fig. 1, the suction portions S is provided for every four spindle units so as to extend parallel to the ducts 44, and is connected to the ducts 44 through connection pipes 48. Each connection pipe 48 has at some midpoint thereof a bellows portion 49 (shown in Fig. 2 alone). In Fig. 1, the suction pipes 32 and 33 are collectively shown as the suction portions S, and suction holes formed in each of the suction pipes 32 and 33 and described below are collectively indicated by broken-line circles. As shown in Fig. 6, formed in the forward end portion of the connection pipe 48, are engagement holes 48a and 48b to which the suction pipes 32 and 33 are detachably mounted. In addition, to the right and left sides of the connection pipe 48, first end portions of the suction pipes 32 and 33 are detachably mounted, and second end portions of the suction pipes 32 and 33 are engaged with the end plug 40. Further, an engagement hole 40b with which the bearing 39 is engaged is formed on the end plug 40. Fig. 6 is a partial schematic perspective view showing a state in which the suction pipes 32 and 33 are mounted to one side of the connection pipe 48. As shown in Fig. 3, the suction pipe 32 has a sliding surface 32b having formed thereon slit-like suction holes 32a extending toward the upstream side with respect to the direction in which the fiber bundle (fleece) F moves, with the nip point of the bottom nip roller 35a being therebetween. The suction pipe 33 has a sliding surface 33b having formed thereon slit-like suction holes 33a extending toward the downstream side. Then, as shown in Figs. 3 and 5, the suction pipe 32 is arranged so as to be on the upstream side of the nip point of the bottom nip roller 35a with respect to the fiber bundle moving direction, and the suction pipe 33 is arranged so as to be on the downstream side thereof. Note that, in Fig. 3, the air-permeable apron 34 is indicated by a chain line so that the suction holes 32a and 33a may be easily seen. Each of the suction pipes 32 is formed in a configuration such that the pipe 32 can guide the air-permeable apron 34 so as to bring the apron 34 near the nip point of the front bottom roller 12 and the front top roller 19. The suction pipes 33 are arranged such that the fiber bundles F sent out from the air-permeable aprons 34 are deflected by a certain fleece angle. The term "fleece angle" means an angle made by the segment connecting the center of curvature of an arcuate surface along which the fiber bundle F (fleece) having passed the nip point is guided to a draw-out position and the nip point and the segment connecting the center of curvature and the draw-out point for the fiber bundle F. The air-permeable aprons 34 are wrapped so as to come into contact partly with the suction pipes 32 and 33 and partly with the bottom nip roller 35a and to rotate while sliding on the sliding surfaces 32b and 33b as the bottom nip rollers 35a rotate. In this embodiment, the air-permeable aprons 34 are formed of woven fabric which can secure appropriate air-permeability. As shown in Figs- 2, 4A, etc., arranged in the vicinity of the lower portion of each suction pipe 33 is a forward end portion of a suction nozzle 50 of a single type pneumatic device adapted to suck the fiber bundle F sent out from the drafting device 11 at the time of thread breakage. A base end of the suction nozzle 50 is connected to a pneumatic duct 51 common among all the spindles. As shown in Fig. 1^ the respective motors 47 are connected to a commercial alternating power source 53 through a common inverter 52. The inverter 52 incorporates a converter circuit and an inverter circuit. An alternating current of the alternating power source 53 is converted into a direct current in the converter circuit, the direct current is then converted into an alternating current corresponding to a desired frequency and voltage in the inverter circuit, and the resultant current is output. The inverter 52 is electrically connected to a control device 54, and controls the motor 47 in accordance with a command signal from the control device 54. The control device 54 is electrically connected to a main control device (not shown) of the spinning machine. The inverter 52 and the control device 54 constitute control means. The control device 54 is provided with a CPU (not shown) and a memory 55, and can communicate with the main control device through a serial interface. Correspondence data etc between a spinning condition including fiber type, counts of thread to be spun, and the like and a rotational speed of the motor 47 are stored in the memory 55. Stored in the memory 55 is data for performing setting in such a manner that the magnitude of a suction pressure that acts on a fiber bundle F satisfies the relationship of large count > middle count > small count in correspondence with the large count, middle count, and small count of spun thread. The data can be obtained by performing, for example, an experimental spinning operation. For example, the suction pressure is set to 4 kPa with respect to the large count, 2 to 3 kPa with respect to the middle count, and 1 to 2 kPa with respect to the small count. The control device 54 is input with the spinning condition data for the spinning operation from the main control device, and notifies the inverter 52 of the rotational speed of the motor 47 in correspondence with the spinning condition. That is, the suction means {suction device 45) is structured such that the suction pressure can be adjusted by the control means (inverter 52 and control device 54), and the control means is structured such that an appropriate suction pressure can be automatically set in correspondence with the spinning condition. Next, the operation of the device constructed as described above will be described. Prior to operation of the spinning frame, spinning conditions for various fiber types and yarn counts of the spun threads etc., are inputted into the main controller. When the spinning frame is operated, the fiber bundle F passes between the bottom rollers 12 through 14 and the top rollers 19 through 21 of the drafting device 11 to be thereby drafted, and is then guided to the fiber bundle collecting device 30. The delivery portion 31 is rotated at a speed somewhat higher than the surface velocity of the front bottom roller 12 and that of the front top roller 19. After passing the nip point of the delivery portion 31 under appropriate tension, the fiber bundle F is deflected and moves downstream while undergoing twisting. Further, the sucking action of the ducts 44 is exerted on the suction pipes 32 and 33 through the connection pipes 48, and the sucking action of the suction holes 32a and 33a formed on the sliding surfaces 32b and 33b is exerted on the fiber bundles F through the air-permeable aprons 34. Then, the fiber bundles F move while being attracted and collected toward positions corresponding to the suctionholes 32a and 33a. Since the suction holes 32a and 33a exist respectively on the upstream side and the downstream side of the nip points of the delivery portions 31, the fiber bundles F move while being collected under the sucking action even after passing the nip points. As a result, fiber separation at both ends of each fiber bundle F after passing the nip point is restrained to suppress generation of fluff and waste cotton, thereby achieving a substantial improvement in the thread-quality enhancing effect. As to the suction device 45, the rotational speed of the motor 47 is controlled by the inverter 52 such that a negative pressure in the duct 44 has an appropriate value corresponding to the spinning condition including thread thickness (count), fiber type, and the like. As a result, thread with desired quality is spun even in the case where the spinning condition is changed. Figs, 7A and 7B, Figs. 7C and 7D, and Figs. 7E and 7F each show a relationship between a suction pressure and hairiness (fluff) and a relationship between a suction pressure and U% in spinning of thread of a large count (carded thread: 10 count), a middle count (combed thread: 40 count), and a small count (combed thread: 80 count), respectively. Note that "hairiness" indicates the total length of fluff that exists in 1cm of thread. However, in general, the hairiness is not expressed in units. The suction pressure, which acts on the fiber bundle F through the suction holes 32a and 33a, causes the quality of spun thread to change. In a region with a low suction pressure, the thread quality is significantly improved along with the rise of the negative pressure (increase of decompression degree), and upon reaching a certain level or more, the negative pressure tends to stay substantially flat, as the fiber bundle is brouqht into a saturation state at that level. As to the magnitude of the negative pressure at which it begins to remain flat, a relationship of large count > middle count > small count is established. Stored in the memory 55 is data for setting the rotational speed of the motor 47 so as to attain the suction pressure determined based on the above spinning result. When the control device 54 is input with the data on the spinning condition from the main control device, the rotational speed appropriate for the spinning condition is given to the inverter 52. Then, the inverter 52 makes control such that the motor 47 has a predetermined rotational speed. This embodiment provides the following effects. (1) The fiber bundle collecting device 30 is provided with the suction means (suction device 45) that can arbitrarily set and change the suction pressure that acts on the suction portion S. Therefore, spinning can be performed while changing the suction pressure, which acts on the suction portion S, to have an appropriate value such that the quality of spun thread satisfies the desired condition in correspondence with the spinning condition. (2) The suction device 45 is driven such that the magnitude of the suction pressure of each of the suction holes 32a and 33a satisfy the relationship of large count > middle count > small count in correspondence with the large count, middle count, and small count of the spun thread. Therefore, spinning is performed while the suction pressure is changed to have an appropriate value in accordance with the thickness of the spun thread, so that the collecting action of the fiber bundle collecting device 30 is appropriately performed in the state in which useless consumption of energy is suppressed. (3) The suction device 45 is driven and controlled by the control means (inverter 52 and control device 54) such that the suction pressure is changeable, and the control means is structured such that the appropriate suction pressure can be automatically set in correspondence with the spinning condition. Therefore, in the case of changing the spinning condition, it is sufficient that the machine operator inputs and sets the spinning conditions prior to the operation. Thus, the operation for changing the spinning condition is easily performed. (4) The suction pipes 32 and 33 provided with the suction holes 32a and 33a respectively, which exert sucking action on the drafted fiber bundle F and are provided in correspondence with the respective spindles, are connected with the duct 44 through the connection pipe 48. The duct 44 is held to have a negative pressure by the plural suction devices 45. Therefore, when one of the suction devices 45 is stopped due to abnormality, the negative pressure generated by the rest of the suction devices 45 secures the sucking action of the suction holes 32a, 33a, and thus, the quality of the spun thread is held in a permissible range. (5) The duct 44 dedicated for the fiber bundle collecting device 30 is provided independently of the pneumatic duct 51. Therefore, the duct 44 can be maintained at a predetermined negative pressure without increasing the suction device 45 in size. (6) The collecting action due to the suction hole 33a provided on the downstream side of the nip point is transmitted to the upstream side of the nip point to some extent. Thus, divergence of the fiber bundle F until the arrival at the nip point is suppressed, and therefore, the collecting action is further improved. The present invention is not limited to the above-described embodiment. For example, the embodiment may be structured as follows. In the above embodiment, under the predetermined spinning condition, spinning is performed at a constant suction pressure of the suction portion S of the fiber bundle collecting device 30 from the start to the end (that is, a full bobbin) of winding of thread to be spun. However, the suction device 45 may be driven and controlled such that the suction pressure of the suction portion S from the start of winding of spun thread to a full bobbin is increased during a period when fluff is easy to be generated, in consideration of the fluff generation condition. Fig. 8 is a graph showing a relationship between the number of generated fluffs and a winding amount in a ring spinning frame not provided with the fiber bundle collecting device 30. The "number of 3 mm fluffs/10 m" in the axis of ordinate of Fig. 8 indicates the number of fluffs each having a length of 3 mm in 10 m of thread. From Fig. 8, it is found that the fluff is easy to be generated at the time when the winding amount of thread to the bobbin reaches approximately 30 percent of the full bobbin (30 percent bundle). In this embodiment, spinning is performed while adjustment is performed such that the suction pressure of the suction portion S is at the maximum at the time when the winding amount of thread to the bobbin reaches approximately 30 percent of the full bobbin. For example, stored in the memory 55 is the data showing a relationship between the winding amount and the suction pressure of the suction portion S for each spinning condition. Then, the control device 54 notifies the inverter 52 of the rotational speed of the motor 47 in correspondence with the winding amount after the start of spinning. The information on the winding amount is input to the control device 54 from the main control device. In this case, spinning is not performed such that the suction pressure of the fiber bundle collecting device 30 is constant from the start to the end (that is, the full bobbin) of winding of the spun thread but performed such that the sucking action of the suction hole is at the maximum at the time when the winding amount of thread to the bobbin reaches approximately 30 percent. As a result, the generation of fluff and thread unevenness become uniform in the thread wound around the full bobbin, which leads to a further improvement of the quality of the spun thread. A structure may be adopted in which the machine operator inputs and sets the spinning condition to the control device 54, instead of the structure in which the control device 54, which controls the motor 47 through the inverter 52 in correspondence with the spinning condition, is input with the data on the spinning condition from the main control device via communication. A structured may be adapted in which, in inputting the spinning condition, the condition is selected among the spinning conditions previously stored in the main control device or the control device 54. The suction pressure of the suction portion S can be set independently of the spinning condition. In this case, the thread quality can be intentionally changed in accordance with the usage of the spun thread, and spinning of thread with excessive quality can be avoided. A structure may be adopted in which the machine operator inputs and sets the rotational speed of the motor 47 to the control device 54, instead of the structure in which: the data showing the relationship between the spinning condition and the suction pressure is previously stored in the control device 54; and the control device 54 drives and controls the motor 47 through the inverter 52 such that the predetermined suction pressure is attained by inputting the spinning condition. In this case, it is preferable that a chart or the like, which shows the relationship between the spinning condition and the rotational speed of the motor 47, be prepared in advance so that the machine operator can check up the rotational speed of the motor 47 which corresponds to the spinning condition by using the chart or the like, A structure may be adopted in which the main control device of the spinning machine also performs the function of the control device 54 and directly outputs a command signal to the inverter 52, without providing the control device 54. Rather than adjusting the suction pressure of the suction portion S to an appropriate value so as to spin the thread with satisfactory quality in a general meaning, that is, the thread that involves little generation of fluff and thread unevenness, the suction pressure of the suction portion S may be adjusted so as to intentionally control the thread quality. For example, the quality required of thread differs between thread for woven fabric and thread for knitted fabric even with the same fiber type. For example, the thread for knitted fabric may have a larger amount of fluff than that of the thread for woven fabric, and energy consumption can be reduced with the suction pressure set to a low level. Further, the suction device 45 may be driven such that the suction pressure of the suction portion S is appropriately changed from the start of winding to the full bobbin for the purpose of positively forming thread unevenness as in design thread, rather than for the purpose of making thread uniform throughout its length. The number of the suction devices 45 connected with the duct 44 is not limited to two or more, and may be one. However, in the case of one device, when the suction device 45 suffers a breakdown, the machine operation has to be stopped immediately to avoid spinning of thread with reduced quality. Thus, the plural suction devices 45 are preferably connected with the duct 44. The length of the duct 44 is not limited to the length corresponding to 24 spindles on one side, and to 48 spindles on both sides, and a length corresponding to the appropriate number of spindles may be adopted. In this case, the preferable length is one corresponding to the spindles with the number of a multiple of 8. One duct 44 may be provided throughout the length of the machine base of the spinning machine instead of providing the plural ducts 44 along the longitudinal direction of the machine base of the spinning machine. The right and left ducts 44 may be arranged in two lines along the longitudinal direction of the machine base of the spinning machine instead of the arrangement in which the duct 44 is shared by the suction pipes 32 and 33 arranged on the right and left sides of the spinning frame. There may be adopted a structure in which one suction device 45 is connected with the duct 44. In the structure in which the plural suction devices 45 are connected with the duct 44, the speed commands to the motors 47 of the respective suction devices 45 are not the same, and the speed command can be set for each of the motors 47• Then, a structure may be adopted in which abnormality detection means for detecting abnormality of the suction devices 45 is provided, and the suction device in which abnormality has occurred is stopped in accordance with an abnormality detection signal from the abnormality detection means and at the same time, the performance of other suction devices 45, which do not exhibit abnormality and are connected with the duct 44 connected with the suction device 45 with abnormality, are enhanced. For example, as shown in Fig. 1 with dotted chains, an abnormality detection sensor 56 for the motor 47, which serves as the abnormality detection means, is provided to each of the suction devices 45. As the abnormality detection sensor 56, for example, a rotational speed sensor of a driving shaft of the motor 47 is used. Then, the control device 54 stops operation of the suction device 45 in which abnormality has occurred, in accordance with the abnormality detection signal from the abnormality detection sensor 56, and also, changes the speed command to the motor 47 such that the performances of the other suction devices 45, which are connected with the duct 44 connected with the suction device 45 with abnormality, are enhanced. In this case, when abnormality occurs in one of the suction devices 45, the operation is continued while the negative pressure in the duct 44 is held in a predetermined range even if the suction device 45 is stopped. Thus, spinning can be continued until the predetermined time of doffing with the quality of the thread to be spun kept in a stable state. In the structure in which the performances of the other suction devices 45 are enhanced in the case of occurrence of abnormality in the suction device 45, control may be performed for each group of the motors 47 connected to the same duct 44 instead of performing independent control for each of the motors 47. For example, in the case where the motor 47 is driven by an inverter, the inverter is provided to each group of the motors 47 connected to the same duct 44. For instance, when three suction devices 45 are connected with the same duct 44, one inverter 52 is provided for every three motors 47. In this case, the control and structure are simplified in comparison with the case where the motors 47 are independently controlled. The position of the duct 44 is not limited to the portion above the rear side of the drafting device 11, and may be the rear side of the drafting device 11 or a portion below the rear side of the drafting device 11. The spinning machine of a so-called single spindle drive system, in which spindles are independently driven by individual motors, is structured such that drive of the spindle that corresponds to each of the suction pipes 32 and 33 and receives the sucking action from the duct 44 connected with the abnormal suction device 45, is stopped in accordance with the abnormality detection signal from the abnormality detection means of the suction device 45. Then, as to the other spindles, spinning is continued until the predetermined time of doffing. In this case, the number of spindles with which spinning is stopped during winding is reduced in comparison with the structure in which spinning of all the spindles is stopped. Instead of the structure in which the rotation shaft 35 and the suction pipes 32 and 33 are arranged such that four spindles constitute one unit, one unit may be composed of the number of spindles between the adjacent roller stands 15 (for example, eight spindles) or two spindles. Alternatively, all the units may not necessarily be composed of the same number of spindles, and two kinds of units may be provided by making the numbers of spindles between the adjacent roller stands 15 to differ from each other {for example, six spindles and two spindles). The suction pipes 32 and 33 may not be formed separately but be integrally formed, and may have an arcuate shape in which the side opposite to the top nip roller 31a is opened. The suction pipes 32 and 33 each may be formed to have a shape in which an end portion on the side opposite to the side facing the connection pipe 48 is closed. In this case, the end plug 40 may be structured so as to have the engagement hole 40b with which the bearing 39 is engaged and the engagement portion (hole) with which the end portions of the suction pipes 32 and 33 are engaged, without consideration of hermetically sealing the end portions of the suction pipes 32 and 33. Thus, manufacture can be simplified. Instead of forming the air-permeable apron 34 from woven fabric or knitted fabric, it may be formed by perforating a belt made ot rubber or resin having elasticity. The suction pipes 32 and 33, which constitute the suction portion, may be formed integrally with the connection pipe 48. The present invention is not limited to the structure in which the suction holes 32a, 33a are provided on the upstream and downstream sides with the nip point of the fiber bundle F sandwiched therebetween. A structure may be adopted in which the suction hole 32a is provided only on the upstream side with respect to the nip point. In this case, the manufacturing method and assembly can be substantially the same by using the suction pipe 33 not having the suction hole 33a formed therein. Further, there may be adopted a structure in which the air-permeable apron 34 is wound around between the suction pipe 32 and the bottom nip roller 35a with the suction pipe 33 being omitted. As to the structure for driving the air-permeable apron 34, the suction pipes 32 and 33 and the bottom nip roller 35a are omitted, a suction pipe with a section having an ovoid shape is provided, a suction hole is formed at a predetermined position in the suction pipe, and the air-permeable apron 34 is slidably wound along the outer circumference of the suction pipe. Then, the top nip roller 31a may be made positively drivable, and may be driven while being in press contact with the air-permeable apron 34, thereby driving the air-permeable apron 34. The structure of the suction device is not limited to the structure in which the fan 47a is driven by the motor 47, For example, a decompression pump (vacuum pump) may be used. The vacuum pump may be of a rotational system or reciprocating system. As the pneumatic device, one with a flute type structure may be adopted instead of a single nozzle type one. A structure may be adopted in which the air-permeable apron 34 is provided on the top side. Hereinafter, description will be made of the invention (technical thoughts) that may be grasped from the above-described embodiments. (1) In the invention according to claim 1 or 6, the suction means is provided with the duct that extends in the longitudinal direction of the machine base of the spinning machine and with the suction device connected with the duct. (2) In the invention according to claim 1 or 6, the suction means is provided with the plural ducts that extend in the longitudinal direction of the machine base of the spinning machine and with the plural suction devices connected with the ducts, the suction devices each are provided with the abnormality detection means, and the suction device with abnormality is stopped in accordance with the abnormality detection signal from the abnormality detection means at which time operation is performed such that the sucking actions of the other suction devices, that are connected with the duct connected with the suction device with abnormality , are enhanced. As described above in detail, according to the invention as described in claims 1 to 5, the suction pressure of the fiber bundle collecting device can be set and changed so as to make the quality of spun thread satisfy the desired condition. Further, according to the invention as described in claim 6, the fiber bundle collecting device is made to exert the appropriate fiber bundle collecting action from the start to the end of winding, thereby being capable of spinning thread with constant quality. What is claimed is: 1. A spinning machine comprising a fiber bundle collecting device which is provided on a downstream side of a final delivery roller pair of a drafting part and collects a fiber bundle drafted by the drafting part, wherein the fiber bundle collecting device comprises: a delivery portion provided with a nip roller; a suction portion provided with a suction hole arranged so as to extend at least toward an upstream side of a nip point of the delivery portion with respect to a moving direction of the fiber bundle; an air-permeable member which constitutes the delivery portion and is rotated along the suction portion; and suction means capable of arbitrarily setting and changing a suction pressure that acts on the suction portion. 2. A spinning machine according to claim 1, wherein the suction means is driven such that a magnitude of the suction pressure is changed to satisfy a relationship of large count > middle count > small count in correspondence with a large count, middle count, and small count of spun thread* 3. A spinning machine according to claim 1 or 2, wherein the suction means is driven and controlled by control means such that the suction pressure is changeable, and the control means is structured such that an appropriate value of the suction pressure can be automatically set in correspondence with a spinning condition • 4. A spinning machine according to any one of claims 1 to 3, wherein the suction portion is provided with a suction pipe having the suction hole corresponding to each spindle, the suction pipe being connected to a duct that is maintained at a negative pressure by plural suction devices. 5. A spinning machine according to claim 4, wherein the duct connected with the suction pipe is provided independently of a pneumatic duct, 6. A spinning method that uses a spinning machine provided with a fiber bundle collecting device on a downstream side of a final delivery roller pair of a drafting part, the device comprising: a delivery portion provided with a nip roller; a suction portion provided with a suction hole arranged so as to extend at least toward an upstream side of a nip point of the delivery portion with respect to a moving direction of a fiber bundle; an air-permeable member which constitutes the delivery portion and is rotated along the suction portion; and suction means capable of arbitrarily setting and changing a suction pressure that acts on the suction portion, and the device collecting the fiber bundle drafted by the drafting part, wherein spinning is performed while adjusting the suction pressure so that the suction pressure becomes a maximum at the time when a winding amount of thread to a bobbin reaches approximately 30 percent of a full bobbin. 7. A spinning machine substantially as herein described with reference to the accompanying drawings

Full Text

SPINNING MACHINE AND SPINNING METHOD
BACKGROUND OF THE INVENTION
The present invention relates to a spinning machine and a spinning method, and more specifically relates to, for example, a spinning machine provided with a fiber bundle collecting device which is arranged downstream of a drafting device (drafting part) of a spinning frame and which collects a fiber bundle drafted by the drafting device and to a spinning method that uses the spinning machine.
Up to now, fiber bundle collecting devices of such type generally utilize sucking action in collection of a fiber bundle (for example, refer to JP 11-286837 A and JP 2000-73224 A) . In each of the devices disclosed in Patent Documents 1 and 2 mentioned above, a hollow profile (guide cylinder) that constitutes a stationary sliding surface having a suction slit is provided on the bottom side downstream of a final roller of a drafting device, and a perforated belt for transfer is wound around the hollow profile. Further, a nip roller, which is held in contact with the perforated belt to define a nip point, is provided on the top side. The nip roller is driven through a conveying belt by means of the final roller. Instead of the structure in which the nip roller is driven through the conveying belt, also disclosed is a structure in which the nip roller is driven through a conveying roller held in contact

with the final roller.
Further, there is disclosed a fiber bundle collecting device with a structure different from that disclosed in Patent Document 1 mentioned above in that the perforated belt is wound between a hollow profile having a suction slit on its sliding surface and a tension roller (refer to JP 2000-34631 A).
It is considered that, when thread is spun with a spinning machine provided with the above-mentioned fiber bundle collecting device, a suction pressure, which acts on the suction slit of the fiber bundle collecting device, affects quality of the thread to be spun. However, up to now, there have been found no document that describes about positively changing the suction pressure in accordance with spinning conditions to spin thread with appropriate quality.
The inventors of the present invention have experimentally changed the suction pressure to examine quality of the spun thread. As a result, the followings have been found: in a region with a low suction pressure, the thread quality is significantly improved along with the rise of a negative pressure {increase of decompression degree); and the thread quality tends to stay flat after reaching a certain level or more, probably because of the fact that a fiber bundle is brought into a saturation state at that level. Further, it has been found that the level at which the pressure begins to stay flat differs depending on a thread size (count), fiber type.

and spindle speed.
The above-mentioned facts lead to the conclusion that it is important that a suction pressure of a certain level or more {hereinafter, referred to as a necessary pressure) be made to act on a fiber bundle in order to increase a collection degree of the fiber bundle through sucking action to thereby realize desired thread quality. However, when pressure setting of a suction device is fixed in correspondence with a spinning condition with a high necessary pressure from the viewpoint of safety, there is produced a result that energy such as power necessary for suction is needlessly consumed, with respect to a spinning condition with a low necessary pressure.
Further, even granted that a suction device is constructed such that a suction pressure is changeable for each spinning condition in consideration of the above situation, there may arise a problem in that: an appropriate value cannot be determined easily even if a machine operator tries to perform pressure setting with no energy wastage; and it involves the trouble of finding the appropriate value based on the experimental spinning performed on several occasions for each change of the spinning condition.
Further, it is known that the thread quality such as fluff is changed in accordance with the change of thread tension in a twisting/winding portion or the like generally in the thread wound around one full bobbin. Therefore, in order to obtain more uniform thread, it might be most appropriate to change the suction pressure.

rather than keeping it at a constant level, from the start of winding (start of spinning) to the full bobbin stop.
SURMMARY OF THE INVENTION The present invention has been made in view of the above problems, and therefore has a first object to provide a spinning machine that enables setting and change of a suction pressure of a fiber bundle collecting device to thereby make quality of spun thread fulfill a desired condition. Further, the present invention has a second object to provide a spinning method in which a fiber bundle collecting device is made to exert appropriate fiber bundle collecting action from the start to the end of winding to thereby spin thread with constant quality.
In order to achieve the above-mentioned first object, the invention as described in claim 1 relates to a spinning machine in which a fiber bundle collecting device for collecting a fiber bundle drafted by a drafting part is provided on a downstream side of a final delivery roller pair of the drafting part. The fiber bundle collecting device is provided with: a delivery portion provided with a nip roller; a suction portion provided with a suction hole arranged so as to extend at least toward an upstream side of a nip point of the delivery portion with respect to a moving direction of the fiber bundle; an air-permeable member which constitutes the delivery portion and is rotated along the suction portion; and suction

means capable of arbitrarily setting and changing a suction pressure that acts on the suction portion.
According to the invention as described above, the fiber bundle drafted in the drafting part is collected by the fiber bundle collecting device provided on the downstream side of the final delivery roller pair of the drafting part, and is moved in a collected state• Thus, generation of fluff and waste cotton are suppressed, and a thread quality improving effect is significantly enhanced as compared with a spinning machine not provided with the fiber bundle collecting device. Collecting action of the fiber bundle collecting device is caused by sucking action of the suction hole of the suction portion to which a suction pressure is imparted by the suction means. Then, the suction means can arbitrarily set and change the suction pressure that acts on the suction portion, and therefore, spinning can be performed while changing the suction pressure to have the optimum value in accordance with a spinning condition.
According to the invention as described in claim 2, in the invention according to claim 1, the suction means is driven such that the magnitude of the suction pressure is changed so as to satisfy the following relationship: large count > middle count > small count, in correspondence with the large count, middle count, and small count of spun thread. In the invention as described above, the suction pressure is changed to have an appropriate value in accordance

with the thickness of the spun thread to perform spinning. As a result, the collecting action of the fiber bundle collecting device is appropriately performed in a state in which waste energy consumption is suppressed.
According to the invention as described in claim 3, in the invention according to claim 1 or 2, the suction means is driven and controlled by control means such that the suction pressure is changeable, and the control means is structured such that the appropriate suction pressure can be automatically set in correspondence with a spinning condition. In the present invention, the spinning condition is set, whereby the appropriate suction pressure is automatically set in the control means in correspondence with the spinning condition. Then, when the spinning machine is operated, the suction means is driven and controlled by the control means such that the suction pressure of the suction portion becomes an appropriate pressure in correspondence with the spinning condition.
According to the invention as described in claim4, in the invention according to any one of claims 1 to 3, the suction portion is provided with a suction pipe having the suction hole corresponding to each spindle, and the suction pipe is connected to a duct that is maintained at a negative pressure by plural suction devices. In the present invention, when one of the suction devices is stopped due to abnormality, the negative pressure generated by the rest

of the suction devices can secure the sucking action of the suction hole. Thus, the quality of spun thread is maintained within a permissible range.
According to the invention as described in claim 5, in the invention according to claim 4, the duct connected with the suction pipe is provided independently of a pneumatic duct. In the present invention, the duct can be maintained at a predetermined negative pressure without increasing the suction device in size.
In order to achieve the second object, the invention as described in claim 6 relates to a spinning method that uses a spinning machine provided with a fiber bundle collecting device on a downstream side of a final delivery roller pair of a drafting part, the device being provided with: a delivery portion provided with a nip roller; a suction portion provided with a suction hole arranged so as to extend at least toward an upstream side of a nip point of the delivery portion with respect to a moving direction of a fiber bundle; an air-permeable member which constitutes the delivery portion and is rotated along the suction portion; and suction means capable of arbitrarily setting and changing a suction pressure that acts on the suction portion, and the device collecting the fiber bundle drafted by the drafting part. Then, spinning is performed while the suction pressure is adjusted so as to be at the maximum at the time when a winding amount of thread to a bobbin reaches approximately 30 percent of a full bobbin.

According to the invention as described above, spinning is not performed such that the suction pressure of the fiber bundle collecting device is constant from the start to the end of winding of spun thread (that is, full bobbin) but performed such that sucking action of the suction hole is at the maximum at the time when the winding amount of thread to the bobbin reaches approximately 30 percent of the full bobbin. As a result, the quality of the spun thread is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
Fig. 1 is a schematic plan view showing an arrangement of a suction device and a duct in accordance with an embodiment;
Fig. 2 is a schematic side view, partly in section showing a drafting device and a fiber bundle collecting device;
Fig. 3 is a partial schematic view showing a relationship between a suction portion and a bottom nip roller; '
Fig. 4A is a partial schematic view of a fiber bundle collecting device as seen from the front in a fiber bundle moving direction and Fig. 4B is a front view of a rotation shaft;
Fig. 5 is partial enlarged view of Fig. 2;
Fig. 6 is a partial perspective view of a connection pipe;
Figs. 7A to 7F are each a graph showing a relationship between a suction pressure and hairiness or a relationship between a suction

pressure and 0% in spinning of threads with different yarn counts; and
Fig. 8 is graph showing a relationship between the number of fluffs and a winding amount in a general ring spinning frame.
DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to Figs. 1 through 8. Fig. 1 is a schematic plan view showing a relationship among a duct of a fiber bundle collecting device, suction devices, and suction portions, and Fig. 2 is a schematic side view, partly in section, showing one side of a drafting device. Fig. 3 is a partial schematic view with the top roller side being omitted, showing a relationship among a bottom roller of a drafting device, and the suction portions and bottom nip rollers of the fiber bundle collecting device. Fig. 4A is a schematic view of the fiber bundle collecting device as seen in a fiber bundle-drawing-out direction at a nip point (as seen from the front side with respect to a fiber bundle moving direction in the drafting device).
As shown in Fig. 2, a drafting device 11 as a draft part is of a three-line construction equipped with a front bottom roller 12, a middle bottom roller 13, and a back bottom roller 14. The front bottom roller 12 is supported at a predetermined position with respect to a roller stand 15, and the middle and back bottom

rollers 13 and 14 are supported through the intermediation of support brackets 13a and 14a secured to the roller stand 15 so as to allow position adjustment in the longitudinal direction. The support brackets 13a and 14a are fastened to predetermined positions by means of bolts passed through an elongated hole formed in the roller stand 15 and nuts (all not shown). A bottom apron 16 is wrapped around a bottom tenser 17 and the middle bottom roller 13.
Supported by a weighting arm 18 through the intermediation of top roller support members are a front top roller 19, a middle top roller 20, and a back top roller 21 at positions respectively corresponding to the front bottom roller 12, the middle bottom roller 13, and the back bottom roller 14. Each of the top rollers 19 through 21 is supported in a two-spindle unit. The front bottom roller 12 and the front top roller 19 constitute a pair of final delivery rollers of the drafting device 11.
Arranged on the weighting arm 18 is a lever 18a so as to be rotatable to a pressurizing position and to a releasing position. In the condition in which the lever 18a is arranged at the pressurizing position where it abuts a frame 18b of the weighting arm 18 shown in Fig. 2, a lock state is maintained in which the top rollers 19 through 21 supported by the weighting arm 18 are in the pressurizing position (spinning position) in which they are pressurized toward the bottom rollers 12, 13, and 14. In the condition in which the lever 18a has been rotated from the condition shown in Fig. 2 to

the upper, releasing position, the lock state is canceled.
As shown in Fig. 2, a fiber bundle collecting device 30 is arranged on the downstream side of the pair of final delivery rollers of the drafting device 11. The fiber bundle collecting device 30 is equipped with a delivery portion 31, suction pipes 32 and 33 as a suction portion S, and an air-permeable apron 34 as an air-permeable member. The deliveryportion 31 is composed of a bottom nip roller 35a as a nip roller, which is formed on a rotation shaft 35 arranged parallel to the front bottom roller 12, and a top nip roller 31a as a nip roller, which is pressurized against the bottom nip roller 35a through the intermediation of the air-permeable apron 34.
As shown in Fig. 4A, in the fiber bundle collecting device 30 of this embodiment, the top nip roller 31a is, like the top rollers 19 through 21 of the drafting device 11, supported every two spindles by the weighting arm 18 through the intermediation of a support member 36 (shown in Figs. 2 and 5). Note that, in this embodiment, the support member 36 is formed integrally with a support member of the front top roller 19.
On the other hand, on the bottom side of the fiber bundle collecting device 30, half the spindles arranged between the roller stands 15 of the drafting device 11, i.e., four spindles in this embodiment, constitute one unit. As shown in Fig. 3, at the middle position of the roller stands 15 arranged at predetermined intervals

in the longitudinal direction of a machine base, a support arm 38 is arranged in a state in which its base end is supported by a support beam 37 extending in the longitudinal direction of the machine base, and the rotation shaft 35 is supported between the roller stand 15 and the support arm 38.
As shown in Fig. 4B, the rotation shaft 35 is formed in a predetermined length corresponding to a plurality of spindles (four spindles in this embodiment), and a bearing 39 is secured to either end thereof. Then, the bearings 39 are fitted into end plugs 40, and, as shown in Fig. 4A, the end plugs 40 are supported in the engagement portions 40a by support portions 15a and 38a provided on the roller stand 15 and the support arm 38, whereby the rotation shaft 35 is rotatably supported between the roller stand 15 and the support arm 38. The support portions 15a and 38a are formed so as to be capable of suppoi;ting two end plugs 40, and are capable of supporting the end plugs 40 which are mounted to the ends of the adjacent rotation shafts 35-
The support portion 15a is formed by a block fixed to the roller stand 15, and has engagement recesses extending obliquely upwards on the front side of the machine base. The support portion 38a also has an engagement recess extending obliquely upwards on the front side of the machine base. Then, the end plug 40 has an engagement portion 40a capable of being engaged with both the engagement recesses, 'and is formed so as to be capable of being engaged, in a single

snap motion, with the support portions 15a and 38a in the engagement portion 40a.
The rotation shaft 35 has at its longitudinal center a gear 41 which is arranged so as to be capable of rotating integrally with the rotation shaft 35. As shown in Fig. 3, the front bottom roller 12 has a gear portion 12a formed at a position opposed to the gear 41. Further, an intermediate gear 43 in mesh with the gear portion 12a and the gear 41 is rotatably supported by a support arm 42 whose base end is fixed to the support beam 37 like the support arm 38. That is, the torque of the front bottom roller 12 is transmitted to the rotation shaft 35 by way of the gear portion 12a, the intermediate gear 43, and the gear 41.
As shown in Figs. 1 and 2, in the machine base of the spinning frame, ducts 44 forthefiber bundle collecting device 30 are arranged so as to extend in a longitudinal direction thereof (in a direction perpendicular to the plane of Fig. 2). As shown in Fig. 1, a plurality of ducts 44 are provided so as to extend in the longitudinal direction of the machine base of the spinning frame. In this embodiment, the length of each duct 44 is such that it corresponds to 24 spindles on one side and 48 spindles on both sides. A plurality of (three in this embodiment) suction devices 45 for maintaining a negative pressure in each duct 44 are connected to each duct 44 through pipes 46. That is, in this embodiment, one suction device 45 is provided for one unit, which is composed of 16 spindles. The suction devices

45 are composed of fan motors in which fans 47a are driven by motors 47. As shown in Fig. 2, the ducts 44 are arranged on the upper rear side of the drafting device 11 and at the center of the machine base of the spinning machine, and the suction devices 45 are arranged below the ducts 44. The suction means is constructed by the ducts 44 and the suction devices 45.
As shown in Fig. 1, the suction portions S is provided for every four spindle units so as to extend parallel to the ducts 44, and is connected to the ducts 44 through connection pipes 48. Each connection pipe 48 has at some midpoint thereof a bellows portion 49 (shown in Fig. 2 alone). In Fig. 1, the suction pipes 32 and 33 are collectively shown as the suction portions S, and suction holes formed in each of the suction pipes 32 and 33 and described below are collectively indicated by broken-line circles.
As shown in Fig. 6, formed in the forward end portion of the connection pipe 48, are engagement holes 48a and 48b to which the suction pipes 32 and 33 are detachably mounted. In addition, to the right and left sides of the connection pipe 48, first end portions of the suction pipes 32 and 33 are detachably mounted, and second end portions of the suction pipes 32 and 33 are engaged with the end plug 40. Further, an engagement hole 40b with which the bearing 39 is engaged is formed on the end plug 40. Fig. 6 is a partial schematic perspective view showing a state in which the suction pipes 32 and 33 are mounted to one side of the connection pipe 48.

As shown in Fig. 3, the suction pipe 32 has a sliding surface 32b having formed thereon slit-like suction holes 32a extending toward the upstream side with respect to the direction in which the fiber bundle (fleece) F moves, with the nip point of the bottom nip roller 35a being therebetween. The suction pipe 33 has a sliding surface 33b having formed thereon slit-like suction holes 33a extending toward the downstream side. Then, as shown in Figs. 3 and 5, the suction pipe 32 is arranged so as to be on the upstream side of the nip point of the bottom nip roller 35a with respect to the fiber bundle moving direction, and the suction pipe 33 is arranged so as to be on the downstream side thereof. Note that, in Fig. 3, the air-permeable apron 34 is indicated by a chain line so that the suction holes 32a and 33a may be easily seen.
Each of the suction pipes 32 is formed in a configuration such that the pipe 32 can guide the air-permeable apron 34 so as to bring the apron 34 near the nip point of the front bottom roller 12 and the front top roller 19. The suction pipes 33 are arranged such that the fiber bundles F sent out from the air-permeable aprons 34 are deflected by a certain fleece angle. The term "fleece angle" means an angle made by the segment connecting the center of curvature of an arcuate surface along which the fiber bundle F (fleece) having passed the nip point is guided to a draw-out position and the nip point and the segment connecting the center of curvature and the draw-out point for the fiber bundle F. The air-permeable aprons

34 are wrapped so as to come into contact partly with the suction pipes 32 and 33 and partly with the bottom nip roller 35a and to rotate while sliding on the sliding surfaces 32b and 33b as the bottom nip rollers 35a rotate. In this embodiment, the air-permeable aprons 34 are formed of woven fabric which can secure appropriate air-permeability.
As shown in Figs- 2, 4A, etc., arranged in the vicinity of the lower portion of each suction pipe 33 is a forward end portion of a suction nozzle 50 of a single type pneumatic device adapted to suck the fiber bundle F sent out from the drafting device 11 at the time of thread breakage. A base end of the suction nozzle 50 is connected to a pneumatic duct 51 common among all the spindles.
As shown in Fig. 1^ the respective motors 47 are connected to a commercial alternating power source 53 through a common inverter 52. The inverter 52 incorporates a converter circuit and an inverter circuit. An alternating current of the alternating power source 53 is converted into a direct current in the converter circuit, the direct current is then converted into an alternating current corresponding to a desired frequency and voltage in the inverter circuit, and the resultant current is output. The inverter 52 is electrically connected to a control device 54, and controls the motor 47 in accordance with a command signal from the control device 54. The control device 54 is electrically connected to a main control device (not shown) of the spinning machine. The inverter 52 and

the control device 54 constitute control means.
The control device 54 is provided with a CPU (not shown) and a memory 55, and can communicate with the main control device through a serial interface. Correspondence data etc between a spinning condition including fiber type, counts of thread to be spun, and the like and a rotational speed of the motor 47 are stored in the memory 55. Stored in the memory 55 is data for performing setting in such a manner that the magnitude of a suction pressure that acts on a fiber bundle F satisfies the relationship of large count > middle count > small count in correspondence with the large count, middle count, and small count of spun thread. The data can be obtained by performing, for example, an experimental spinning operation. For example, the suction pressure is set to 4 kPa with respect to the large count, 2 to 3 kPa with respect to the middle count, and 1 to 2 kPa with respect to the small count.
The control device 54 is input with the spinning condition data for the spinning operation from the main control device, and notifies the inverter 52 of the rotational speed of the motor 47 in correspondence with the spinning condition. That is, the suction means {suction device 45) is structured such that the suction pressure can be adjusted by the control means (inverter 52 and control device 54), and the control means is structured such that an appropriate suction pressure can be automatically set in correspondence with the spinning condition.

Next, the operation of the device constructed as described above will be described.
Prior to operation of the spinning frame, spinning conditions for various fiber types and yarn counts of the spun threads etc., are inputted into the main controller. When the spinning frame is operated, the fiber bundle F passes between the bottom rollers 12 through 14 and the top rollers 19 through 21 of the drafting device
11 to be thereby drafted, and is then guided to the fiber bundle collecting device 30. The delivery portion 31 is rotated at a speed somewhat higher than the surface velocity of the front bottom roller
12 and that of the front top roller 19. After passing the nip point of the delivery portion 31 under appropriate tension, the fiber bundle F is deflected and moves downstream while undergoing twisting.
Further, the sucking action of the ducts 44 is exerted on the suction pipes 32 and 33 through the connection pipes 48, and the sucking action of the suction holes 32a and 33a formed on the sliding surfaces 32b and 33b is exerted on the fiber bundles F through the air-permeable aprons 34. Then, the fiber bundles F move while being attracted and collected toward positions corresponding to the suctionholes 32a and 33a. Since the suction holes 32a and 33a exist respectively on the upstream side and the downstream side of the nip points of the delivery portions 31, the fiber bundles F move while being collected under the sucking action even after passing the nip points. As a result, fiber separation at both ends of each

fiber bundle F after passing the nip point is restrained to suppress generation of fluff and waste cotton, thereby achieving a substantial improvement in the thread-quality enhancing effect.
As to the suction device 45, the rotational speed of the motor 47 is controlled by the inverter 52 such that a negative pressure in the duct 44 has an appropriate value corresponding to the spinning condition including thread thickness (count), fiber type, and the like. As a result, thread with desired quality is spun even in the case where the spinning condition is changed.
Figs, 7A and 7B, Figs. 7C and 7D, and Figs. 7E and 7F each show a relationship between a suction pressure and hairiness (fluff) and a relationship between a suction pressure and U% in spinning of thread of a large count (carded thread: 10 count), a middle count (combed thread: 40 count), and a small count (combed thread: 80 count), respectively. Note that "hairiness" indicates the total length of fluff that exists in 1cm of thread. However, in general, the hairiness is not expressed in units. The suction pressure, which acts on the fiber bundle F through the suction holes 32a and 33a, causes the quality of spun thread to change. In a region with a low suction pressure, the thread quality is significantly improved along with the rise of the negative pressure (increase of decompression degree), and upon reaching a certain level or more, the negative pressure tends to stay substantially flat, as the fiber bundle is brouqht into a saturation state at that level. As to the

magnitude of the negative pressure at which it begins to remain flat, a relationship of large count > middle count > small count is established. Stored in the memory 55 is data for setting the rotational speed of the motor 47 so as to attain the suction pressure determined based on the above spinning result. When the control device 54 is input with the data on the spinning condition from the main control device, the rotational speed appropriate for the spinning condition is given to the inverter 52. Then, the inverter 52 makes control such that the motor 47 has a predetermined rotational speed.
This embodiment provides the following effects.
(1) The fiber bundle collecting device 30 is provided with the suction means (suction device 45) that can arbitrarily set and change the suction pressure that acts on the suction portion S. Therefore, spinning can be performed while changing the suction pressure, which acts on the suction portion S, to have an appropriate value such that the quality of spun thread satisfies the desired condition in correspondence with the spinning condition.
(2) The suction device 45 is driven such that the magnitude of the suction pressure of each of the suction holes 32a and 33a satisfy the relationship of large count > middle count > small count in correspondence with the large count, middle count, and small count of the spun thread. Therefore, spinning is performed while the suction pressure is changed to have an appropriate value in

accordance with the thickness of the spun thread, so that the collecting action of the fiber bundle collecting device 30 is appropriately performed in the state in which useless consumption of energy is suppressed.
(3) The suction device 45 is driven and controlled by the control means (inverter 52 and control device 54) such that the suction pressure is changeable, and the control means is structured such that the appropriate suction pressure can be automatically set in correspondence with the spinning condition. Therefore, in the case of changing the spinning condition, it is sufficient that the machine operator inputs and sets the spinning conditions prior to the operation. Thus, the operation for changing the spinning condition is easily performed.
(4) The suction pipes 32 and 33 provided with the suction holes 32a and 33a respectively, which exert sucking action on the drafted fiber bundle F and are provided in correspondence with the respective spindles, are connected with the duct 44 through the connection pipe 48. The duct 44 is held to have a negative pressure by the plural suction devices 45. Therefore, when one of the suction devices 45 is stopped due to abnormality, the negative pressure generated by the rest of the suction devices 45 secures the sucking action of the suction holes 32a, 33a, and thus, the quality of the spun thread is held in a permissible range.
(5) The duct 44 dedicated for the fiber bundle collecting device

30 is provided independently of the pneumatic duct 51. Therefore, the duct 44 can be maintained at a predetermined negative pressure without increasing the suction device 45 in size.
(6) The collecting action due to the suction hole 33a provided on the downstream side of the nip point is transmitted to the upstream side of the nip point to some extent. Thus, divergence of the fiber bundle F until the arrival at the nip point is suppressed, and therefore, the collecting action is further improved.
The present invention is not limited to the above-described embodiment. For example, the embodiment may be structured as follows.
In the above embodiment, under the predetermined spinning condition, spinning is performed at a constant suction pressure of the suction portion S of the fiber bundle collecting device 30 from the start to the end (that is, a full bobbin) of winding of thread to be spun. However, the suction device 45 may be driven and controlled such that the suction pressure of the suction portion S from the start of winding of spun thread to a full bobbin is increased during a period when fluff is easy to be generated, in consideration of the fluff generation condition. Fig. 8 is a graph showing a relationship between the number of generated fluffs and a winding amount in a ring spinning frame not provided with the fiber bundle collecting device 30. The "number of 3 mm fluffs/10 m" in the axis of ordinate of Fig. 8 indicates the number of fluffs each having

a length of 3 mm in 10 m of thread. From Fig. 8, it is found that the fluff is easy to be generated at the time when the winding amount of thread to the bobbin reaches approximately 30 percent of the full bobbin (30 percent bundle). In this embodiment, spinning is performed while adjustment is performed such that the suction pressure of the suction portion S is at the maximum at the time when the winding amount of thread to the bobbin reaches approximately 30 percent of the full bobbin. For example, stored in the memory 55 is the data showing a relationship between the winding amount and the suction pressure of the suction portion S for each spinning condition. Then, the control device 54 notifies the inverter 52 of the rotational speed of the motor 47 in correspondence with the winding amount after the start of spinning. The information on the winding amount is input to the control device 54 from the main control device. In this case, spinning is not performed such that the suction pressure of the fiber bundle collecting device 30 is constant from the start to the end (that is, the full bobbin) of winding of the spun thread but performed such that the sucking action of the suction hole is at the maximum at the time when the winding amount of thread to the bobbin reaches approximately 30 percent. As a result, the generation of fluff and thread unevenness become uniform in the thread wound around the full bobbin, which leads to a further improvement of the quality of the spun thread.
A structure may be adopted in which the machine operator inputs

and sets the spinning condition to the control device 54, instead of the structure in which the control device 54, which controls the motor 47 through the inverter 52 in correspondence with the spinning condition, is input with the data on the spinning condition from the main control device via communication.
A structured may be adapted in which, in inputting the spinning condition, the condition is selected among the spinning conditions previously stored in the main control device or the control device 54.
The suction pressure of the suction portion S can be set independently of the spinning condition. In this case, the thread quality can be intentionally changed in accordance with the usage of the spun thread, and spinning of thread with excessive quality can be avoided.
A structure may be adopted in which the machine operator inputs and sets the rotational speed of the motor 47 to the control device 54, instead of the structure in which: the data showing the relationship between the spinning condition and the suction pressure is previously stored in the control device 54; and the control device 54 drives and controls the motor 47 through the inverter 52 such that the predetermined suction pressure is attained by inputting the spinning condition. In this case, it is preferable that a chart or the like, which shows the relationship between the spinning condition and the rotational speed of the motor 47, be prepared

in advance so that the machine operator can check up the rotational speed of the motor 47 which corresponds to the spinning condition by using the chart or the like,
A structure may be adopted in which the main control device of the spinning machine also performs the function of the control device 54 and directly outputs a command signal to the inverter 52, without providing the control device 54.
Rather than adjusting the suction pressure of the suction portion S to an appropriate value so as to spin the thread with satisfactory quality in a general meaning, that is, the thread that involves little generation of fluff and thread unevenness, the suction pressure of the suction portion S may be adjusted so as to intentionally control the thread quality. For example, the quality required of thread differs between thread for woven fabric and thread for knitted fabric even with the same fiber type. For example, the thread for knitted fabric may have a larger amount of fluff than that of the thread for woven fabric, and energy consumption can be reduced with the suction pressure set to a low level. Further, the suction device 45 may be driven such that the suction pressure of the suction portion S is appropriately changed from the start of winding to the full bobbin for the purpose of positively forming thread unevenness as in design thread, rather than for the purpose of making thread uniform throughout its length.
The number of the suction devices 45 connected with the duct

44 is not limited to two or more, and may be one. However, in the case of one device, when the suction device 45 suffers a breakdown, the machine operation has to be stopped immediately to avoid spinning of thread with reduced quality. Thus, the plural suction devices
45 are preferably connected with the duct 44.
The length of the duct 44 is not limited to the length corresponding to 24 spindles on one side, and to 48 spindles on both sides, and a length corresponding to the appropriate number of spindles may be adopted. In this case, the preferable length is one corresponding to the spindles with the number of a multiple of 8.
One duct 44 may be provided throughout the length of the machine base of the spinning machine instead of providing the plural ducts
44 along the longitudinal direction of the machine base of the spinning
machine.
The right and left ducts 44 may be arranged in two lines along the longitudinal direction of the machine base of the spinning machine instead of the arrangement in which the duct 44 is shared by the suction pipes 32 and 33 arranged on the right and left sides of the spinning frame.
There may be adopted a structure in which one suction device
45 is connected with the duct 44.
In the structure in which the plural suction devices 45 are connected with the duct 44, the speed commands to the motors 47

of the respective suction devices 45 are not the same, and the speed command can be set for each of the motors 47• Then, a structure may be adopted in which abnormality detection means for detecting abnormality of the suction devices 45 is provided, and the suction device in which abnormality has occurred is stopped in accordance with an abnormality detection signal from the abnormality detection means and at the same time, the performance of other suction devices 45, which do not exhibit abnormality and are connected with the duct 44 connected with the suction device 45 with abnormality, are enhanced. For example, as shown in Fig. 1 with dotted chains, an abnormality detection sensor 56 for the motor 47, which serves as the abnormality detection means, is provided to each of the suction devices 45. As the abnormality detection sensor 56, for example, a rotational speed sensor of a driving shaft of the motor 47 is used. Then, the control device 54 stops operation of the suction device 45 in which abnormality has occurred, in accordance with the abnormality detection signal from the abnormality detection sensor 56, and also, changes the speed command to the motor 47 such that the performances of the other suction devices 45, which are connected with the duct 44 connected with the suction device 45 with abnormality, are enhanced. In this case, when abnormality occurs in one of the suction devices 45, the operation is continued while the negative pressure in the duct 44 is held in a predetermined range even if the suction device 45 is stopped. Thus, spinning can

be continued until the predetermined time of doffing with the quality of the thread to be spun kept in a stable state.
In the structure in which the performances of the other suction devices 45 are enhanced in the case of occurrence of abnormality in the suction device 45, control may be performed for each group of the motors 47 connected to the same duct 44 instead of performing independent control for each of the motors 47. For example, in the case where the motor 47 is driven by an inverter, the inverter is provided to each group of the motors 47 connected to the same duct 44. For instance, when three suction devices 45 are connected with the same duct 44, one inverter 52 is provided for every three motors 47. In this case, the control and structure are simplified in comparison with the case where the motors 47 are independently controlled.
The position of the duct 44 is not limited to the portion above the rear side of the drafting device 11, and may be the rear side of the drafting device 11 or a portion below the rear side of the drafting device 11.
The spinning machine of a so-called single spindle drive system, in which spindles are independently driven by individual motors, is structured such that drive of the spindle that corresponds to each of the suction pipes 32 and 33 and receives the sucking action from the duct 44 connected with the abnormal suction device 45, is stopped in accordance with the abnormality detection signal from

the abnormality detection means of the suction device 45. Then, as to the other spindles, spinning is continued until the predetermined time of doffing. In this case, the number of spindles with which spinning is stopped during winding is reduced in comparison with the structure in which spinning of all the spindles is stopped.
Instead of the structure in which the rotation shaft 35 and the suction pipes 32 and 33 are arranged such that four spindles constitute one unit, one unit may be composed of the number of spindles between the adjacent roller stands 15 (for example, eight spindles) or two spindles. Alternatively, all the units may not necessarily be composed of the same number of spindles, and two kinds of units may be provided by making the numbers of spindles between the adjacent roller stands 15 to differ from each other {for example, six spindles and two spindles).
The suction pipes 32 and 33 may not be formed separately but be integrally formed, and may have an arcuate shape in which the side opposite to the top nip roller 31a is opened.
The suction pipes 32 and 33 each may be formed to have a shape in which an end portion on the side opposite to the side facing the connection pipe 48 is closed. In this case, the end plug 40 may be structured so as to have the engagement hole 40b with which the bearing 39 is engaged and the engagement portion (hole) with which the end portions of the suction pipes 32 and 33 are engaged, without consideration of hermetically sealing the end portions of

the suction pipes 32 and 33. Thus, manufacture can be simplified.
Instead of forming the air-permeable apron 34 from woven fabric or knitted fabric, it may be formed by perforating a belt made ot rubber or resin having elasticity.
The suction pipes 32 and 33, which constitute the suction portion, may be formed integrally with the connection pipe 48.
The present invention is not limited to the structure in which the suction holes 32a, 33a are provided on the upstream and downstream sides with the nip point of the fiber bundle F sandwiched therebetween. A structure may be adopted in which the suction hole 32a is provided only on the upstream side with respect to the nip point. In this case, the manufacturing method and assembly can be substantially the same by using the suction pipe 33 not having the suction hole 33a formed therein. Further, there may be adopted a structure in which the air-permeable apron 34 is wound around between the suction pipe 32 and the bottom nip roller 35a with the suction pipe 33 being omitted.
As to the structure for driving the air-permeable apron 34, the suction pipes 32 and 33 and the bottom nip roller 35a are omitted, a suction pipe with a section having an ovoid shape is provided, a suction hole is formed at a predetermined position in the suction pipe, and the air-permeable apron 34 is slidably wound along the outer circumference of the suction pipe. Then, the top nip roller 31a may be made positively drivable, and may be driven while being

in press contact with the air-permeable apron 34, thereby driving the air-permeable apron 34.
The structure of the suction device is not limited to the structure in which the fan 47a is driven by the motor 47, For example, a decompression pump (vacuum pump) may be used. The vacuum pump may be of a rotational system or reciprocating system.
As the pneumatic device, one with a flute type structure may be adopted instead of a single nozzle type one.
A structure may be adopted in which the air-permeable apron 34 is provided on the top side.
Hereinafter, description will be made of the invention (technical thoughts) that may be grasped from the above-described embodiments.
(1) In the invention according to claim 1 or 6, the suction means is provided with the duct that extends in the longitudinal direction of the machine base of the spinning machine and with the suction device connected with the duct.
(2) In the invention according to claim 1 or 6, the suction means is provided with the plural ducts that extend in the longitudinal direction of the machine base of the spinning machine and with the plural suction devices connected with the ducts, the suction devices each are provided with the abnormality detection means, and the suction device with abnormality is stopped in accordance with the abnormality detection signal from the abnormality detection means

at which time operation is performed such that the sucking actions of the other suction devices, that are connected with the duct connected with the suction device with abnormality , are enhanced. As described above in detail, according to the invention as described in claims 1 to 5, the suction pressure of the fiber bundle collecting device can be set and changed so as to make the quality of spun thread satisfy the desired condition. Further, according to the invention as described in claim 6, the fiber bundle collecting device is made to exert the appropriate fiber bundle collecting action from the start to the end of winding, thereby being capable of spinning thread with constant quality.

What is claimed is:
1. A spinning machine comprising a fiber bundle collecting
device which is provided on a downstream side of a final delivery
roller pair of a drafting part and collects a fiber bundle drafted
by the drafting part,
wherein the fiber bundle collecting device comprises: a delivery portion provided with a nip roller; a suction portion provided with a suction hole arranged so as to extend at least toward an upstream side of a nip point of the delivery portion with respect to a moving direction of the fiber bundle; an air-permeable member which constitutes the delivery portion and is rotated along the suction portion; and suction means capable of arbitrarily setting and changing a suction pressure that acts on the suction portion.
2. A spinning machine according to claim 1, wherein the suction means is driven such that a magnitude of the suction pressure is changed to satisfy a relationship of large count > middle count > small count in correspondence with a large count, middle count, and small count of spun thread*
3. A spinning machine according to claim 1 or 2, wherein the suction means is driven and controlled by control means such that the suction pressure is changeable, and the control means is structured such that an appropriate value of the suction pressure can be automatically set in correspondence with a spinning condition •

4. A spinning machine according to any one of claims 1 to 3, wherein the suction portion is provided with a suction pipe having the suction hole corresponding to each spindle, the suction pipe being connected to a duct that is maintained at a negative pressure by plural suction devices.
5. A spinning machine according to claim 4, wherein the duct connected with the suction pipe is provided independently of a pneumatic duct,
6. A spinning method that uses a spinning machine provided with a fiber bundle collecting device on a downstream side of a final delivery roller pair of a drafting part, the device comprising: a delivery portion provided with a nip roller; a suction portion provided with a suction hole arranged so as to extend at least toward an upstream side of a nip point of the delivery portion with respect to a moving direction of a fiber bundle; an air-permeable member which constitutes the delivery portion and is rotated along the suction portion; and suction means capable of arbitrarily setting and changing a suction pressure that acts on the suction portion, and the device collecting the fiber bundle drafted by the drafting part, wherein spinning is performed while adjusting the suction pressure so that the suction pressure becomes a maximum at the time when a winding amount of thread to a bobbin reaches approximately 30 percent of a full bobbin.

7. A spinning machine substantially as herein described with reference to the accompanying drawings

Documents:

714-che-2003-abstract.pdf

714-che-2003-claims filed.pdf

714-che-2003-claims granted.pdf

714-che-2003-correspondnece-others.pdf

714-che-2003-correspondnece-po.pdf

714-che-2003-description(complete) filed.pdf

714-che-2003-description(complete) granted.pdf

714-che-2003-drawings.pdf

714-che-2003-form 1.pdf

714-che-2003-form 19.pdf

714-che-2003-form 26.pdf

714-che-2003-form 3.pdf

714-che-2003-form 5.pdf

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Patent Number

198705

Indian Patent Application Number

714/CHE/2003

PG Journal Number

04/2005

Publication Date

11-Feb-2005

Grant Date

30-Jan-2006

Date of Filing

08-Sep-2003

Name of Patentee

M/S. KABUSHIKI KAISHA TOYOTA JIDOSHOKKI

Applicant Address

2-1 TOYODA-CHO, KARIYA-SHI, AICHI-KEN,

Inventors:

#	Inventor's Name	Inventor's Address
1	TSUTOMU NAKANO	C/o KABUSHIKI KAISHA TOYOTO JIDOSHOKKI, 2-1 TOYADA-CHO, KARIYA-SHI, AICHI-KEN
2	KIWAMU NIIMI	2-1 TOYODA-CHO, KARIYA-SHI, AICHI-KEN
3	NAOKI MARUYAMA	2-1 TOYODA-CHO, KARIYA-SHI, AICHI-KEN
4	TAKAHISA ISHII	2-1 TOYODA-CHO, KARIYA-SHI, AICHI-KEN

PCT International Classification Number

D01D5/092

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA