Title of Invention

AN IMPROVED CLEANING DEVICE

Abstract

A cleaning device comprising a housing (2); a trolley (3) movable on overhead rails (22); plurality of hangers (4) attached to said trolley; at least one blast wheel (5) to propel a blast medium towards the hangers; a first drive means for driving the hangers in a circular path, a second drive means for rotating the hangers around their own axis while they rotate in said circular path, and lifting means for moving the hangers up and down in a vertical direction, while rotating.

Full Text

running time, power usage, material usage for a particular application and consequently resulting in higher cost of production. In an existing shot blasting machine, the components which are to be cleaned are kept on a hanger which can be rotated. When the component is closer to the blast wheel, the surface areas which are in direct contact with the blast stream gets cleaned by high intensity blast stream. The hidden surface area comes in direct contact with the blast stream when the hanger is rotated by 180 degrees. However, the component is far from the blast wheel and therefore the blast stream will be of less intensity. This results in higher operational time and non-uniformity in surface finish. In order to improve the cleaning, the hidden areas of the material which are to be cleaned should be moved so that it comes in direct contact with the blast stream. The existing shot blasting machine comprises a hanger on which the materials which are to be cleaned are placed. If the hidden areas of the materials to be cleaned are moved to the direct blast stream contact areas, the time of cleaning, the usage of the blast medium and tile wastage of the blast medium, are reduced. The objective of the present invention is to expose all the areas of the component to higher intensity blast stream to improve the operational time and uniformity of surface finish. It is possible when component is placed in the center axis of the hanger. However, it will be less productive since traditional hanger has only one axis and fewer parts can be kept on the single axis available. The invention tries to solve the problem by having number of hangers that rotate around the center point, while they rotate themselves. According to the present invention, the axis of rotation of hangers get shifted from the center towards the blast stream which is beneficial as hangers get positioned in higher intensity blast stream. The parts kept in the center of the hangers not only gets exposed in all sides evenly but also exposed in higher intensity blast stream. This will improve the cleaning efficiency and uniformity of surface finish. This feature combined with vertical movable hanger mechanism will improve the reach of the blast stream further resulting in greater improvement in cleaning efficiency and uniformity of surface finish. Depending upon the size of the component to be cleaned, the number of hangers can be increased or decreased to optimize the output of the machine. Even if more than one part is kept in the hanger, they are subjected to higher intensity of the blast stream than traditional type since the axis of rotation has got shifted towards the blast stream in the new type. An object of the present invention is to provide a cleaning device with a plurality of hangers, each of which rotate around their own axis while rotating in a circular path. Yet another object of the present invention is to provide a cleaning device with a plurality of hangers which are vertically movable as well as relatable around their own axis while rotating in said circular path. In order to expose more areas of the material to get cleaned, the hangers which hold the components to be cleaned are made to rotate around their axis while rotating is a circular path. The hangers may be moved up and down to further improve the reach of the blast stream. The mechanism to rotate the hangers and the mechanism to move the hanger vertically can work independently. The combination of these two mechanisms will reduce the cleaning time and the blast medium usage. There will be an improvement in the surface of the material which are cleaned by the cleaning device of the present invention due to the fact that more areas get exposed to the direct blast stream of higher intensity. Further, the difference between a poorly cleaned surface and a well cleaned surface will be less since more areas have been exposed to high intensity blast stream resulting in improved surface finish. According to the cleaning device of the present invention, the surface areas which are to be cleaned will not come under severe blasting since the hangers are rotated about their own axis while rotating in said circular path. Accordingly the present invention provides a cleaning device comprising a housing; a trolley movable on overhead rails; plurality of hangers attached to said trolley; at least one blast wheel to propel a blast medium towards the hangers; a first drive means for driving the hangers in a circular path, a second drive means for rotating the hangers around their own axis while they rotate in said circular path, and lifting means for moving the hangers up and down in a vertical direction, while rotating. This invention will be described in detail in the following with reference to the accompanying drawing, in which Figure 1 shows a cleaning device according to the present invention. As shown in Figure 1, the cleaning device comprises a trolley (3), a housing (2), at least one blast wheel (5) and a plurality of hangers (4). The trolley (3) is movable on rails (22) and carries the hanger (4). The blast wheel (5) is powered by motors to propel the blast medium towards the hanger. The trolley includes at least one pair of wheels (21), a support frame (23) for connecting the wheels, a tube (7) rigidly connected to the support frame and a splinted shaft (12). One end of the shaft is held by a thrust ball bearing (13) and located inside the tube whereas tiles other end of the shaft carries a hook (20), The first drive means includes a sprocket (6) which is connected to the trolley through a bracket disposed between two sets of bearings (9) which are mounted on the tube (7). Brackets (11a), (lib) keep the two sets of bearings in its position. Bracket (11a) is fixed to the tube and bracket (11 b) is fixed using a thread provided inside the tube. The sprocket (6) is driven by a change drive. Sprocket has internal splints to transmit the motion to the splined shaft for rotating the shaft and the hangers (4) which are connected to the shaft. One end of the splined shaft which carries a hook (20) has a spring (19) loaded sliding cover (18) which is guided by a guide (18a) provided in the housing. The said guide allows the cover (18) to slide up and down on the shaft to avoid major spillage of the blast medium during blasting. The tube (7) has two slots (8) to allow the extension of a lifting stand (16) which has two supports. The hefting stand (16) is Tufted by lifting means (17). During blasting the lifting means can be moved electrically, hydraulically, mechanically, pneumatically or in combination of the above. The sprocket (6) is internally splined so that it drives the shaft to rotate the hanger even as the shaft moves up and down. The second drive means includes a rigid tube (25), at least one primary gear wheel (26) and a plurality of secondary gear wheels (27). The rigid tube (25) has a hook (24) at one end which is connected to the hook (20) of the rotating shaft. The primary gear wheel (26) is mounted on the rigid tube (25) by means of a pair of bearings (29) and brackets (30). The primary gear wheel (26) is locked to the housing using a mechanical lock (28), so that it cannot rotate but allows rotation of the rigid tube. The rigid tube (25) is connected to a plurality of secondary gear wheels (27) which are is meshing arrangement with the primary gear wheel (26). At least one hanger (4) is fixed to each of the secondary gear wheel (27). The gear wheel assembly is protected from the blast medium by a cover (32) which has an upper part and a lower part. The upper part (32a) of the cover is fixed to the primary gear wheel (26) which in turn is locked to the housing using a mechanical lock (28) so that the primary wheel cannot rotate but allows rotation of the rigid tube. The locking position of the primary gear wheel can be changed by the operation of a suitable mechanism even during blasting operation. The lower part (32b) of the cover is fixed to the secondary gear wheels (27) and to the rigid tube (25) so as to rotate with the circular motion of the tube (25). The lower part of the cover has a slot (33) in which the secondary gear w^heels are fixed by means of a nut (34). The slot (33) has a sliding cover (not shown) incorporated therein to prevent blast medium entering into gear wheel mechanism. A hanger (4) is connected to each of the secondarv' gear wheels (27). Supporting members (31) are provided to support the lower part of the cover. The primary gear wheel (26) can be attached with another gear wheel of different diameters to impart motion to another batch of hangers rotating at different pitch circle diameter to optimize productivity It is possible to alter ratio of rotation of primary gear wheel and the meshing secondary gear wheel with another set of gear drives to obtain the desired rotational ratio. The operation of the cleaning device according to the present invention is now described. The components or material which are to be cleaned are kept on the hangers (4) while the primary gear wheel is locked using the mechanical lock (28). The blast wheels (5) are powered by a motor to propel the blast medium, such as steel shots or sand, towards the component which are placed on the hangers. The sprocket (6) is driven by a chain drive which in turn rotates the splined shaft (12). The rigid tube which is attached to the bottom end of the shaft also rotates. The hangers are moved up and down as they rotate by lifting the stand (16) attached to the top end of the shaft. The vertical movement of the hangers can be done in steps so as to reduce the energy requirement for the lifting means. The primary gear wheel is locked by means of a mechanical lock so that it is not allowed to rotate but movable up and down in vertical direction. The bearings of the primary gear wheel allow the rotation of the rigid tube. The lower part of the cover which is attached to the tube transmits the circular motion to the secondary' gear wheels which are in meshing arrangement with the primary gear wheel. The rigid tube drives the secondary gear wheels and the hangers attached therewith in a circular path. The secondary gear wheels and the hangers attached thereto made to rotate around their own axis by the static primary gear wheel. Therefore, the hangers made to rotate around their own axis while they rotate in said circular path. The components kept on the lingers gets cleaned faster since all the surface areas of the components come in direct contact with the high intensity blast stream. Among the advantages of the cleaning device of the present invention are reduced time for shot blasting and improved uniformity in surface finish. The parts to be cleaned are moved vertically and circularly in relation to the blast stream as the hangers rotate around timeservers while they rotate in a circular path resulting in early exposure of the hidden areas and avoidance of severe blasting on the same surface. According to the cleaning device of the present invention the majority of the surface of the components are cleaned be abrasive action of the direct hitting heath intensity blast medium which is more productive. Having described preferred embodiment of the invention with reference to the accompanying drawing, it is to be understood that the invention is not limited to this preferred embodiment and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope of spirit of the invention as defined in the appended claims. WE CLAIM: 1. A cleaning device comprising a housing (2) ; a trolley (3) movable on overhead rails (22); plurality of hangers (4) attached to said trolley; at least one blast wheel (5) to propel a blast medium towards tile hangers; a first drive means for driving the hangers in a circular path, a second drive means for rotating the hangers around their own axis while they rotate in said circular path, and lifting means for moving the hangers up and down in a vertical direction, while rotating. 2. The cleaning device as claimed in claim 1 wherein the said trolley comprises at least one pair of wheels (21), a support foamed (23) connecting the wheels, a tube (7) rigidly connected to the support frame and a splinted shaft (12) carrying a hook (20) at its one end. 3. The cleaning device as claimed in claims 1 or 2 wherein the other end of the splinted shaft (12) is held by a thrust ball bearing (13) and is placed inside the tube (7) on its half-way. 4. The cleaning device as claimed in any one of the preceding claims wherein the said first drive means has a sprocket (6) which is driven by a chain drive to rotate the said hook (20). The cleaning device as claimed in any of the preceding claims wherein the sprockets (6) is connected to the tibia (7) by means of a bracket (10) and a pair of bearings (9). The cleaning device as claimed in any of the preceding claims wherein the sprocket has internal spines to transmit the motion to the splinted shaft (12) for rotating the hook (20). The cleaning device as claimed in any one of the preceding claims wherein the said second drive means comprises a rigid tube (25) carrying a hook (24) on one end, at least one primary gear wheel (26) mounted on the rigid tube with the help of a pair of bearings (29) and brackets (30), a purity of secondary gear wheels (27) meshing with the primary gear wheel and connected to the rigid tube. The cleaning device as claimed in any of the preceding claims wherein at least one hanger (4) is attached to each of the secondary gear wheel (27). The cleaning device as claimed in any of the preceding claims wherein the primary and secondary gear wheels are protected by a cover (32) having an upper part (32a) and a lower part (32b). The cleaning device as claimed in any of the preceding claims wherein the upper part of the cover is fixed on the primary gear wheel and is locked with the housing by a mechanical lock (28) so that the upper part of the cover and the primary gear wheel are not allowed to rotate but movable up and down in vertical direction. The cleaning device as claimed in any of the preceding claims wherein the lower part of the cover has a circular slot (33) and is fixed to the tube. The cleaning device as claimed in any of the preceding claims wherein the secondary' gear wheels are fixed in the slot (33) provided in the lower part of the cover with the help of a nut (34). The cleaning device as claimed in any of the preceding claims wherein a studding cover is provided in the slot to prevent blast stream entering into the gear wheels. The cleaning device as claimed in any of the preceding claims wherein the splinted shaft (12) carries a spring (19) loaded shadings cover (18) which is guided by a guide (18a) for avoiding spillage of the blast medium during blasting. The cleaning device as claimed in any of the preceding claims wherein one end of the shaft is held by the thrust ball bearing (13). The cleaning device as claimed in any of the preceding claims wherein lifting means comprises a lifting stand (17) for moving a support (16) which is connected to one end of the shaft. The cleaning device as claimed in any of the preceding claims wherein the said tube (7) has two slots (8) to allow the vertical movement of the lifting support (16). A cleaning device substantially as hereinbefore described with reference to the accompanying drawings.

Documents:

491-mas-2000-abstract.pdf

491-mas-2000-claims granted.pdf

491-mas-2000-claims filed.pdf

491-mas-2000-correspondnece-others.pdf

491-mas-2000-correspondnece-po.pdf

491-mas-2000-description(complete) filed.pdf

491-mas-2000-description(complete) granted.pdf

491-mas-2000-drawings.pdf

491-mas-2000-form 1.pdf

491-mas-2000-form 19.pdf

491-mas-2000-form 26.pdf

491-mas-2000-form 3.pdf

491-mas-2000-form 5.pdf