Single sheet feeding device and a scanner equipped with such a device

• US 6,244,587 B1
• Filed: 05/28/1999
• Issued: 06/12/2001
• Est. Priority Date: 11/28/1996
• Status: Expired due to Fees

• Current Assignee: Tekniko Design AB
• Original Assignee: Tekniko Design AB
• Inventors: Hermander, Göran
• Primary Examiner(s): Ellis, Christopher P.
• Assistant Examiner(s): Bower, Kenneth W
• Application Number:
  US09/308,980
• Time in Patent Office: 746 Days
• Field of Search: 271/34, 271/124, 271/125
• US Class Current: 271/34
• CPC Class Codes: B65H 2220/02 indicating an entity which is controlled, adjusted or changed by a control process, i.e. output
• CPC Class Codes: B65H 2220/04 for distinguishing adjusting from controlling, i.e. manual adjustments
• CPC Class Codes: B65H 2220/11 indicating that the input or output entities exclusively relate to machine elements
• CPC Class Codes: B65H 2301/42322 from bottom of the pile
• CPC Class Codes: B65H 2511/21 Angle
• CPC Class Codes: B65H 3/042 separating from the bottom of the pile
• CPC Class Codes: B65H 3/5238 Retainers of the pad-type, e.g. friction pads
• CPC Class Codes: H04N 1/00567 Handling of original or reproduction media, e.g. cutting, separating, stacking
• CPC Class Codes: H04N 1/0061 Feed belts
• CPC Class Codes: H04N 1/00628 Separating, e.g. preventing feeding of two sheets at a time

Abstract

A sheet feeder for advancing paper sheets one by one, has at least one traveling feeder belt whose one side is a feed plane and a stationary sheet restraining or retarding element that has a friction surface that faces towards and is spaced from the feed plane. The space between the friction surface and the feed plane forms a feed opening whose gap decreases in the feed direction. The feed belt runs on a belt support that is stationary, flat and rigid and extends along the greater part of the feed opening in the sheet transporting direction.

Claims

1. A sheet feeder for advancing paper sheets one by one, comprising

at least one traveling feeder belt having an outer side that defines a feed plane;

a belt support which remains stationary during operation of the feeder, said belt support being substantially rigid and substantially flat; and

a sheet restraining or retarding element which remains stationary during operation of the feeder, said restraining or retarding element having a friction surface that faces towards the feed plane and is spaced therefrom, wherein the friction surface and the feed plane together define a feed opening whose gape decreases in a feed direction, the feeder belt runs on said belt support at least in the region of the feed opening, and said belt support extends along more than half of the feed opening in the feed direction.

2. A scanner equipped with the sheet feeder according to claim 1.

3. A sheet feeder according to claim 1, wherein the belt support is comprised of a feed table on which a sheet stack can be stored for feeding of the sheets, wherein the table has a length and a width that will accommodate the maximum sheet size for which the feeder is intended, and wherein the feed belt extends over at least half the full extension of the feed table in the feed direction.

4. A sheet feeder according to claim 3 wherein the feed belt extends over the full extension of the feed table.

5. A sheet feeder according to claim 1, in which at least said outer side of said feed belt or said friction surface is elastically pliable.

6. A sheet feeder according to claim 5, wherein said sheet restraining or retarding element has a part forming said friction surface and the feed belt and/or the part of said sheet restraining or retarding element forming the friction surface is/are comprised of an elastic material.

7. A sheet feeder according to claim 6, in which the feed belt and that part of the sheet restraining or retarding element which forms the friction surface are both made of said elastic material;

and in that said elastic material has a high coefficient of friction relative to paper.

8. A sheet feeder according to claim 5, wherein said sheet restraining or retarding element has a part forming said friction surface, and the feed belt and that part of the sheet restraining or retarding element which forms the friction surface are made of the same material.

9. A sheet feeder according to claim 8 wherein said same material has a high coefficient of friction relative to paper.

10. A sheet feeder according to claim 1, in which the feed opening is wedge-shape with a pointed end of the opening located in the feed direction such that the gape of the feed opening will successively decrease in the feed direction.

11. A sheet feeder according to claim 10, in which the feed opening has an extension in the feed direction in the range of 30-100 mm, a largest gape in the range of 0.3-5 mm, and a largest ratio of gape to extension in the feed direction of from 1:

200 to 1-20.

12. A sheet feeder according to claim 11, in which said extension is about 50 mm, said largest gape of the feed opening is about 2 mm and said ratio is about 1:

50.

13. A sheet feeder according to claim 12, provided with means for adjusting the distance between the feed plane and the friction surface and/or for adjusting the ratio between the largest gape of the feed plane and the extension in the feed direction.

14. A sheet feeder according to claim 13, which includes automatic control means for actuation if said adjustment means.

15. A sheet feeder according to claim 13, in which said control means includes optical detecting means for sensing a height of the sheet stack drive means for driving said adjustment means, and signaling means for transmitting signals to the drive means from the detection means for adjusting the adjustment means by way of said drive means in response to a signal representing the height of the sheet stack.

16. A sheet feeder according to claim 12, provided with at least one adjuster for changing the distance, between the feed plane and the friction surface and/or for changing the ratio between the largest gape of the feed plane and the extension in the feed direction.

17. A sheet feeder according to claim 16, which includes an automatic control system for actuation of said at least one adjuster.

18. A sheet feeder according to claim 16, in which said control system includes an optical detector for sensing a height of the sheet stack, a drive motor for driving said at least one adjuster, and a signal carrier for transmitting signals to the drive motor from the detector for adjusting the at least one adjuster by way of said drive motor in response to a signal representing the height of the sheet stack.