Sheet supplying apparatus

• US 5,722,654 A
• Filed: 10/18/1996
• Issued: 03/03/1998
• Est. Priority Date: 06/19/1992
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tomura, Hisayuki, Morinaga, Kazuyuki, Sootome, Sumitoshi
• Primary Examiner(s): SKAGGS JR, H GRANT
• Application Number:
  US08/732,719
• Time in Patent Office: 501 Days
• Field of Search: 271/119, 271/122, 271/126, 271/127, 271/164, 271/170, 271/116
• US Class Current: 271/119
• CPC Class Codes: B65H 3/0669 Driving devices therefor
• CPC Class Codes: B65H 3/5261 Retainers of the roller type, e.g. rollers

Abstract

The present invention provides a sheet supplying apparatus having a sheet stacking device for stacking and supporting sheets, a sheet supply roller having different radial dimensions along a periphery thereof to feed out the sheets from the sheet stacking device, and a separation unit having a feed rotary member rotated in a sheet feeding direction and a reverse rotary member rotated in a direction opposite to the sheet feeding direction to separate the sheets fed out by the sheet supply roller one by one.

Claims

1. An image forming apparatus, comprising:

a sheet cassette drawably mounted onto a main body of said apparatus and for containing sheets therein;

a sheet supply roller provided in the main body for feeding out a sheet, said sheet supply roller having a peripheral portion that is partially cut;

sheet support means provided in said sheet cassette for supporting the sheets and urging the sheets towards said sheet supply roller;

separating means for separating the sheets fed out from said sheet support means by said sheet supply roller, said separating means having a normal rotation roller provided in the main body and rotating in a sheet feeding direction and a retard roller provided in said sheet cassette and rotating in a direction opposite to the sheet feeding direction;

retard roller supporting means provided in said sheet cassette for rockably supporting said retard roller, and urging means for urging the retard roller toward the normal rotation roller when said sheet cassette is mounted on said main body;

a drive output member provided in the main body of the apparatus and connected to a drive source provided in the main body of the apparatus; and

a drive input member connected to the retard roller to be engaged with the drive output member when said sheet cassette is mounted onto the main body to transmit the drive force to the retard roller.

2. An image forming apparatus according to claim 1, wherein a draw-out direction of the sheet cassette from the main body and the sheet feed-out direction from said sheet support means by said sheet supply roller are the same, and the retard roller is disposed forwardly in the draw-out direction of the sheet cassette.

3. An image forming apparatus according to claim 1, wherein the retard roller supporting means is a lever rockably attached to the sheet cassette, and said urging means is a coil spring.

4. An image forming apparatus according to claim 1, wherein the drive output member is an output gear receiving drive force from the drive source, and said drive input member is an input gear transmitting the drive force to the retard roller, so that when the sheet cassette is mounted on to the main body the input gear meshes with the output gear to thereby transmit the drive force of said drive source is transmitted to the retard roller.

5. An image forming apparatus according to claim 4, wherein the drive output gear receives the drive force from a drive shaft of the normal rotation roller.

6. An image forming apparatus according to claim 1, wherein in a course of drive transmitting means for transmitting the drive force from the drive input member to the retard roller, a torque limiter for transmitting only the drive force smaller than a predetermined value to the retard roller is provided.

7. An image forming apparatus according to claim 1, further comprising control means for controlling rotation of said sheet supply roller so that, upon non-supplying of the sheet, said sheet supply roller stops at a position where the cut portion thereof faces to the sheets supported by said sheet support means.

8. An image forming apparatus according to claim 1, further comprising convey means for conveying upwardly to the main body a sheet separated by said separating means.

9. An image forming apparatus according to claim 1, wherein said sheet support means is rockably supported and includes an urging member biasing upward the sheet support means to urge the supported sheets against said sheet supply roller.

10. An image forming apparatus according to claim 9, further comprising regulation means for regulating an upper surface of the sheets urged by said sheet support member toward said sheet supply roller to maintain in a predetermined position where said sheet supply roller contacts with the upper surface of the sheets to feed out the sheet.

11. An image forming apparatus according to claim 10, wherein said regulating means is a separating pawl separating the sheets fed out by said sheet supply roller.

12. An image forming apparatus, comprising:

a sheet cassette drawably mounted onto a main body of said apparatus and for containing sheets therein;

a sheet supply roller provided in the main body for feeding out a sheet, said sheet supply roller having a peripheral portion that is partially cut;

sheet support means provided in said sheet cassette for supporting the sheets and urging the sheets toward said sheet supply roller;

separating means for separating the sheets fed out from said sheet support means by said sheet supply roller, said separating means having a normal rotation roller provided in the main body and rotating in a sheet feeding direction, and a retard roller provided in said sheet cassette and rotating in a direction opposite to the sheet feeding direction;

a drive output member provided in the main body of the apparatus and connected to a drive source provided in the main body of the apparatus;

a drive input member connected to the retard roller to be engaged with the drive output member when said sheet cassette is mounted onto the main body to transmit the drive force to the retard roller; and

drive transmitting means provided in the sheet cassette for transmitting a drive force from the drive input member to the retard roller, wherein said drive transmitting means has a torque limiter for transmitting only a drive force smaller than a predetermined value to the retard roller.

13. An image forming apparatus according to claim 12, wherein a draw-out direction of the sheet cassette from the main body and the sheet feed-out direction from said sheet support means by said sheet-supply roller are the same, and the retard roller is disposed forwardly in the draw-out direction of the sheet cassette.

14. An image forming apparatus according to claim 12, wherein said sheet support means is rockably supported and includes an urging member biasing upward the sheet support means to urge the supported sheets against said sheet supply roller.

15. An image forming apparatus according to claim 14, further comprising regulation means for regulating an upper surface of the sheets urged by said urging member toward said sheet supply roller to maintain in a predetermined position where said sheet supply roller contacts with the upper surface of the sheets to feed out the sheet.

16. An image forming apparatus according to claim 15, wherein said regulating means is a separating pawl to separate the sheets fed out by said sheet supply roller.