Sheet-material feeding device and image forming apparatus

• US 6,224,052 B1
• Filed: 10/17/1996
• Issued: 05/01/2001
• Est. Priority Date: 10/26/1995
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nagano, Toshiyuki
• Primary Examiner(s): Ellis, Christopher P.
• Assistant Examiner(s): Mackey, Patrick
• Application Number:
  US08/733,330
• Time in Patent Office: 1,657 Days
• Field of Search: 271/110, 271/121, 271/124, 271/126, 271/127, 271/147, 271/154, 271/145, 271/155, 271/156, 271/258.01, 271/273, 271/274, 271/118, 271/119
• US Class Current: 271/127
• CPC Class Codes: B65H 1/14 comprising positively-acting mechanical devices B65H1/025 takes precedence
• CPC Class Codes: B65H 2403/421 involving at least a gear with toothless portion
• CPC Class Codes: B65H 3/0661 for separating inclined-stacked articles with separator rollers above the stack

Abstract

A sheet-material feeding device individually separating and sequentially feeding a bundle of sheets of a sheet material mounted on a sheet-material mount. The device includes a detector for detecting the presence of the sheet material on the sheet-material mount, and a pressing member for pressing the sheet material on the sheet-material mount when the presence of the sheet material has been detected by the detetector. A sheet-mounting angle of the sheet-material mount can be changed so that an upstream portion of the bundle of sheets is lower than a portion where the sheets are separated.

Claims

1. A sheet-material feeding device for individually separating and sequentially feeding a bundle of sheets of a sheet material, the feeding device comprising:

a sheet-material mount without a drop preventing wall;

detection means for detecting a presence of the sheet material on the sheet-material mount;

separating means for separating an individual sheet from the bundle of sheets;

means for changing a sheet-mounting angle of the sheet-material mount so that an upstream portion of the bundle of sheets is moved from a position higher than said separating means to a position lower than said separating means; and

pressing means for pressing the sheet material on the sheet-material mount when the presence of the sheet material has been detected by said detection means, and for preventing the sheet material from being displaced from the sheet material mount as a result of movement in an upstream direction when the upstream portion of the bundle of sheets is moved from the position higher than said separating means to the position lower than said separating means.

2. A feeding device according to claim 1, wherein the feeding device is an automatic original-feeding device disposed on an upper frame of an openable image forming apparatus, and wherein the sheet-material mount is displaced when the image forming apparatus is opened.

3. A feeding device according to claim 1, wherein the feeding device is a sheet-material feeding device disposed on an upper frame of an openable image forming apparatus, and wherein the sheet-material mount is displaced when the image forming apparatus is opened.

4. A feeding device according to claim 1, wherein the feeding device is a sheet-material feeding device disposed on a side openable image forming apparatus, and wherein the sheet-material mount is displaced when a side is opened.

22. A sheet-material feeding device according to claim 1, wherein said pressing means moves to a retracted position when individual sheets of the bundle of sheets begin to be separated by said separating means.

23. A sheet-material feeding device according to claim 22, wherein said pressing means moves to a pressing position after individual sheets of the bundle of sheets have been separated.

27. A sheet-material feeding device according to claim 1, wherein the sheet-material feeding device is contained within an apparatus and the sheet-material mount extends outside of said apparatus.

5. A sheet-material feeding device for individually separating and sequentially feeding a bundle of sheets of a sheet material, the feeding device comprising:

a sheet-material mount without a drop preventing wall;

a rotating member for feeding the sheet material from the sheet-material mount;

a rising member movable between a pressing position for pressing the bundle of sheets against said rotating member, and a retracted position for releasing the bundle of sheets;

detection means for detecting a supporting state in which the bundle of sheets is supported by the sheet-material mount, and for generating a corresponding detection signal; and

means for changing a sheet-mounting angle of the sheet-material mount so that an upstream portion of the bundle of sheets is moved from a position higher than said pressing position to a position lower than said pressing position,

wherein said rising member assumes the retracted position when the bundle of sheets is not in the supported state and the pressing position when the bundle of sheets is in the supported state, in accordance with the detection signal from said detection means, and

wherein said rising member prevents the sheet material from being displaced from the sheet-material mount as a result of movement in an upstream direction when the upstream portion of the bundle of sheets is moved from the position higher than said pressing position to the position lower than said pressing position.

6. A feeding device according to claim 5, further comprising separation means, disposed downstream from said rising member, for separating and feeding individual sheets of the bundle of sheets in cooperation with said rotating member.

7. A feeding device according to claim 6, wherein said separation means comprises a frictional pad urged against said rotating member by a biasing means.

8. A feeding device according to claim 7, wherein said rising member moves to the retracted position when the individual sheets of the bundle of sheets begin to be separated by said rotating member and said frictional pad.

9. A feeding device according to claim 8, wherein said rising member moves to the pressing position when the individual sheets of the bundle of sheets have been separated.

10. A feeding device according to claim 9, wherein said rising member moves to the pressing position when the feeding device stops an operation due to occurrence of a jam of one or more sheets.

11. A feeding device according to claim 10, wherein, after said device has stopped the operation, a biasing means urges said rising member to remain in the pressing position.

28. A sheet-material feeding device according to claim 5, wherein said rising member has a frictional member.

29. A sheet-material feeding device according to claim 5, wherein said sheet-material feeding device is contained within an apparatus and said sheet-material mount extends outside of said apparatus.

12. An image forming apparatus comprising:

reading means for reading an image of an original; and

a main body having an openable/closable member, the openable/closable member including;

a sheet-material mount without a drop preventing wall;

a sheet-material feeding device for individually separating and sequentially feeding to said reading means a bundle of sheets of a sheet material mounted on said sheet-material mount, the device comprising;

a rotating member for feeding the sheet material from the sheet-material mount;

a rising member movable between a pressing position for pressing the bundle of sheets against said rotating member, and a retracted position for releasing the bundle of sheets; and

detection means for detecting a supporting state in which the bundle of sheets is supported by the sheet-material mount, and for generating a corresponding detection signal,

wherein said rising member assumes the retracted position when the bundle of sheets is not in the supported state and the pressing position when the bundle of sheets is in the supported state, in accordance with the detection signal from said detection means,

wherein at least the openable/closable member of said main body including said sheet-material feeding device is rotatable between an opened position and a closed position, and

wherein the openable/closable member of said main body rotates in a direction that reduces an angle between the bundle of sheets set on said sheet-material mount and a horizontal plane when rotating from the closed position to the opened position, and

wherein said rising member prevents the sheet material from being displaced from the sheet-material mount as a result of movement in an upstream direction when the upstream portion of the bundle of sheets is moved from the position higher than said pressing position to the position lower than said pressing position.

14. An image forming apparatus according to claim 12 or 13, wherein the openable/closable member of said main body is an upper frame of said main body.

30. An image forming apparatus according to claim 12, wherein the rising member has a frictional member.

31. An image forming apparatus according to claim 12, wherein said sheet-material mount extends outside of said image forming apparatus.

13. An image forming apparatus comprising:

image forming means for forming an image on a sheet material; and

a main body having an openable/closable member, the openable/closable member including;

a sheet-material mount without a drop preventing wall;

a sheet-material feeding device for individually separating and sequentially feeding to said image forming means a bundle of sheets of a sheet material mounted on said sheet-material mount, the device comprising;

a rotating member for feeding the sheet material;

a rising member movable between a pressing position for pressing the bundle of sheets against said rotating member, and a retracted position for releasing the bundle of sheets; and

detection means for detecting a supported state in which the bundle of sheets is supported by the sheet-material mount, and for generating a corresponding detection signal,

wherein said rising member assumes the retracted position when the bundle of sheets is not in the supported state and the pressing position when the bundle of sheets is in the supported state, in accordance with the detection signal from said detection means,

wherein at least the openable/closable member of said main body including said sheet-material feeding device is rotatable between an opened position and a closed position, and

wherein the openable/closable member of said main body rotates in a direction that reduces an angle between the bundle of sheets set on said sheet-material mount and a horizontal plane when rotating from the closed position to the opened position, and

wherein said rising member prevents the sheet material from being displaced from the sheet-material mount as a result of movement in an upstream direction when the upstream portion of the bundle of sheets is moved from the position higher than said pressing position to the position lower than said pressing position.

15. An image forming apparatus according to claim 13, wherein the openable/closable member of said main body is a multisheet feeding unit comprising feeding means for feeding the sheet material to said image forming means, the feeding unit being disposed within said the main body.

16. An image forming apparatus according to claim 15, wherein the openable/closable member of said main body includes a conveying path for guiding the sheet material conveyed from a sheet accommodating unit.

32. An image forming apparatus according to claim 13, wherein said rising member has a frictional member.

33. An image forming apparatus according to claim 13, wherein said sheet-material mount extends outside of said image forming apparatus.

17. A sheet-material feeding device for individually separating and sequentially feeding a bundle of sheets of a sheet material, said feeding device comprising:

driving means for transmitting and changing a direction of operation of a driving force;

a rotating member for feeding an individual sheet of the bundle of sheets;

a rising member movable between a pressing position for pressing the bundle of sheets against said rotating member and a retracted position for releasing the bundle of sheets; and

a switching mechanism, disposed between said driving means and said rotating member and between said driving means and said rising member, for transmitting the driving force of said driving means to said rotating member and said rising member, said switching mechanism comprising;

a switching member being movable to a first position in accordance with a driving force transmitted by said driving means and rotated in one direction, and to a second position in accordance with a driving force transmitted by said driving means and rotated in another direction;

a sheet-material mount without a drop preventing wall; and

means for changing a sheet-mounting angle of the sheet-material mount so that an upstream portion of the bundle of sheets is moved from a position higher than said pressing position to a position lower than said pressing position;

wherein, said rising member presses the sheet material on the sheet-material mount when the presence of the sheet material has been detected by a detection means, and prevents the sheet material from being displaced from the sheet-material mount as a result of movement in an upstream direction when the upstream portion of the bundle of sheets is moved from the position higher than said pressing position to the position lower than said pressing position;

wherein, when said switching member is in the first position, said switching member rotates said rotating member so that said rotating member conveys the sheet from the bundle of sheets in the pressed state, and moves said rising member from the pressing position to the retracted position after a predetermined time period, and, when said switching member is in the second position, said switching member moves said rising member from the retracted position to the pressing position.

18. A feeding device according to claim 17, wherein said switching member comprises a switching gear for revolving around an external circumference of an input gear while simultaneously rotating.

19. A feeding device according to claim 17, wherein said driving means comprises a driving motor capable of performing forward rotation and reverse rotation, and wherein said switching mechanism further comprises:

a driving gear rotating in one of a forward and a reverse direction in accordance with forward rotation and reverse rotation of said driving motor;

a switching gear rotating and meshing with said driving gear and said switching member, and being moveable to a first and second position by a connection arm provided between said switching gear and said driving gear;

a first idler gear for rotating and meshing with said switching gear when said switching gear moves to the first position in accordance with one of forward rotation and reverse rotation of said driving motor;

a second idler gear for rotating and meshing with said switching gear when said switching gear moves to the second position in accordance with one of reverse rotation and forward rotation of said driving motor;

a feeding gear for meshing with said first idler gear and rotatably driving said rotating member by the rotation of said first idler gear in accordance with one of forward rotation and reverse rotation of said driving motor, and by the movement of said switching gear to the first position in accordance with one of forward rotation and the reverse rotation of said driving motor; and

a cam gear meshing with said first idler gear and said second idler gear,

wherein said cam gear moves said rising member from the pressing position to the retracted position, after a predetermined time period, by the rotation of said first idler gear in accordance with one of forward rotation and reverse rotation of said driving motor and by the movement of said switching gear to the first position, and said cam gear moves said rising member from the retracted position to the pressing position by the rotation of said second idler gear in accordance with movement of said switching gear to the second position.

20. A feeding device according to claim 19, further comprising a frictional pad for forming a separation nip portion with said rotating member, said frictional pad being pressed by said rotating member and being disposed downstream from said rising member in a feeding direction of the sheet material.

21. A feeding device according to claim 19, wherein said cam gear comprises a cam, and wherein said rising member includes a cam follower urged against said cam by a biasing member.

34. A sheet-material feeding device according to claim 17, wherein said rising member has a frictional member.

35. A sheet-material feeding device according to claim 17, wherein said sheet-material feeding device is contained within an apparatus and said sheet-material mount extends outside of said apparatus.

24. An image forming apparatus comprising:

reading means for reading an image of an original; and

a main body having an openable/closable member, the openable/closable member including;

a sheet-material feeding device disposed on an upper portion of the openable/closable member and for individually separating and sequentially feeding to said reading means a bundle of sheets of a sheet material mounted on a sheet-material mount, said sheet-material mount without a drop preventing wall, the device comprising;

detection means for detecting a presence of the sheet material on the sheet-material mount;

separating means for separating an individual sheet from the bundle of sheets;

pressing means for pressing the sheet material on the sheet-material mount when the presence of the sheet material has been detected by said detection means, and for preventing the sheet material from being displaced from the sheet-material mount as a result of movement in an upstream direction when an upstream portion of the bundle of sheets is moved from a position higher than said separating means to a position lower than said separating means;

wherein at least the openable/closable member of said main body including said sheet-material feeding device is rotatable between an opened position and a closed position, and

wherein the openable/closable member of said main body rotates in a direction that reduces an angle between the bundle of sheets set on said sheet-material mount and a horizontal plane when rotating from the closed position to the opened position.

25. An image forming apparatus according to claim 24, wherein said pressing means moves to a retracted position when individual sheets of the bundle of sheets begin to be separated by said separating means.

26. An image forming apparatus according to claim 25, wherein said pressing means moves to a pressing position after individual sheets of the bundle of sheets have been separated.

36. An image forming apparatus according to claim 24, wherein said sheet-material mount extends outside of said image forming apparatus.