Claims
- 1. A device for supporting an endless belt used in an electrophotographic print engine, comprising:
- a frame;
- an endless belt;
- a drive roller for supporting said belt, said drive roller being operatively associated with said frame;
- an idler roller for supporting said belt;
- an idler shaft for supporting said idler roller, said idler shaft being mounted relative to said frame for travel along a path segment such that if said idler shaft travels in a first direction along said path segment, said belt is placed in progressively greater tension, and if said idler shaft travels along said path segment in a second direction opposite to said first direction, said belt is placed in progressively lesser tension;
- a second shaft mounted in operable association with said frame such that said second shaft may rotate about its longitudinal axis relative to said frame;
- means for urging said idler roller in said first direction, such that said endless belt is maintained in tension during operation of said print engine;
- a tensioning cam pivotably attached to said frame, said tension cam defining a cam surface segment, said segment configured to be in contact with said idler shaft such that said cam allows said idler roller mounted upon said idler shaft to travel in said first direction, but not in said second direction;
- a pegged release cam mounted for rotation with said second shaft during nonoperation of said print engine in order to replace said endless belt, said pegged release cam including a peg and also including a cam surface for selectively contacting, pivoting and disengaging said tensioning cam upon rotation of said pegged release cam;
- a retracting cam mounted for rotation about said second shaft, said retracting cam including an arcuate slot for receiving said peg, said retracting cam also defining a substantially cylindrical boss having a longitudinal axis substantially parallel but offset relative to said second shaft;
- a retracting plate defining a substantially circular aperture configured to rotatably accept said substantially circular boss of said retracting cam, and also defining a second aperture configured to encircle said idler shaft;
- such that as said second shaft is rotated in a first direction, said peg of said pegged release cam disengages said tensioning cam, and thereafter engages said retracting cam such that said reacting cam retracts said retracting plate such that said idler shaft travels in said second direction such that said endless belt is slackened.
- 2. A device for supporting an endless belt used in an electrophotographic print engine, comprising:
- a frame;
- an endless belt;
- a drive roller for supporting said belt, said drive roller being operatively associated with said frame;
- an idler roller for supporting said belt;
- an idler shaft for supporting said idler roller, said idler shaft being mounted relative to said frame for travel along a path segment such that if said idler shaft travels in a first direction along said path segment, said belt is placed in progressively greater tension, and if said idler shaft travels along said path segment in a second direction opposite to said first direction, said belt is placed in progressively lesser tension;
- a second shaft mounted in operable association with said frame such that said second shaft may rotate about it longitudinal axis relative to said frame;
- means for urging said idler roller in said first direction, such that said endless belt is maintained in tension during operation of said print engine;
- a tensioning cam pivotably attached to said frame, said tensioning cam defining a cam surface segment, said segment configured to be in contact with said idler shaft such that said cam allows said idler shaft to travel in said first direction, but not in said second direction;
- a pegged release cam mounted for rotation with said second shaft during nonoperation of said print engine in order to replace said endless belt, said pegged release cam including a peg having a longitudinal axis substantially parallel but offset relative to said second shaft, said pegged release cam also including a cam surface for successively contacting, pivoting and disengaging said tensioning cam upon rotation of said pegged release cam;
- a retracting cam mounted for rotation relative to said second shaft about said longitudinal axis of rotation of said second shaft, said retracting cam defining a closed-ended arcuate slot for receiving said peg,
- said arcuate slot configured to allow said peg to travel a finite distance within said arcuate slot during a segment of rotation of said pegged release cam relative to said extracting cam without interfering with said slot, said arcuate slot also configured to interfere with said peg at the beginning and end of travel through said segment of rotation such that said peg interferes with said slot and causes said retracting cam to rotate with said pegged release cam,
- said retracting cam also defining a substantially cylindrical boss having a longitudinal axis substantially parallel but offset relative to said second shaft;
- a retracting plate defining a substantially circular aperture configured to rotatably accept said substantially circular boss of said retracting cam, and also defining a second aperture configured to enclose said idler shaft,
- such that as said second shaft is rotated in a first direction, said pegged release cam disengages said tensioning cam and thereafter engages said retracting cam, such that said retracting cam rotates with said second shaft and retracts said retracting plate due to said offset relation such that said retracting plate urges said idler shaft in said second direction and said endless belt is slackened.
TECHNICAL FIELD
The present invention relates to print engines for electrophotography and particularly discloses an improved endless belt tensioning and quick release device, having a plurality of individual improvements, which maintains tension on endless belts used in such systems and also allows for quick replacement of such belts. This application is a continuation-in-part of and incorporates by reference U.S. application Ser. No. 028,973 U.S. Pat. No. 4,788,572 filed Mar. 23, 1987, entitled "Belt Controls For A Print Engine For Color Electrophotography".
US Referenced Citations (7)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0134057 |
Aug 1982 |
JPX |
Non-Patent Literature Citations (1)
Entry |
IBM Technical Disclosure Bulletin, vol. 22 No. 7, Dec. 1979. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
28973 |
Mar 1987 |
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