Paper sheet feeding apparatus

• US 5,143,365 A
• Filed: 01/02/1991
• Issued: 09/01/1992
• Est. Priority Date: 08/14/1989
• Status: Expired due to Term

• Current Assignee: Thiele Technologies, Inc. (Barry-Wehmiller Group Incorporated)
• Original Assignee: Ronald J. Green
• Inventors: Green, Ronald J.
• Primary Examiner(s): Olszewski, Robert P.
• Assistant Examiner(s): REISS, STEVEN
• Application Number:
  US07/636,597
• Time in Patent Office: 608 Days
• Field of Search: 271/35, 271/109, 271/110, 271/117, 271/121, 271/124, 271/125, 271/137, 271/138
• US Class Current: 271/121
• CPC Class Codes: B65H 2301/42322 from bottom of the pile
• CPC Class Codes: B65H 3/042 separating from the bottom of the pile
• CPC Class Codes: B65H 3/523 the retainers positioned over articles separated from the bottom of the pile

Abstract

Disclosed is a sheet feeder device including means for supporting a generally vertical stack of sheets. The supporting means include endless belts having an upper belt run position to extend across the bottom of the stack of sheets. A stationary gate forming member is provided which is positioned above the upper run of the belts and adjacent the forward side of the stack to define a nip which forms a gap between the gate forming member and the upper run for permitting the lowermost sheet of the stack to pass forwardly from the stack through the nip. The gate forming member is a cylindrical roll defining a central axis and an outer peripheral surface which is concentric to the central axis. The roll has a groove extending axially along the length thereof. An elastomeric bar is disposed in the groove, and the bar has a coefficient of friction which is higher than that of the material of the roll. Also, the bar is sized so as to extend radially beyond the peripheral surface. This portion of the bar includes a rearwardly facing edge surface which extends generally along a tangent to the outer peripheral surface of the roll. In operation, the lowermost sheet is fed by the endless belts through the nip without engaging the bar and without significant frictional resistance, while the sheet immediately above the lowermost sheet engages the bar and is retarded in its advance by its engagement with the material of the bar.

Claims

1. An apparatus for serially feeding sheets in a forward direction from the bottom of a generally vertical stack of such sheets and comprising:

a frame,

means mounted to said frame for supporting the generally vertical stack of sheets and so that the stack defines a forward side composed of aligned forward edges of the sheets, and a bottom, said supporting means including endless belt means and means rotatably mounting said endless belt means so as to have an upper run positioned to extend across the bottom of said stack;

drive means for rotating said endless belt means so that said upper run moves in the forward direction;

a gate forming member positioned above said upper run of said belt means and adjacent the forward side of said stack and so as to define a nip which forms a gap between said gate forming member and said upper run for permitting the lowermost sheet of the stack to pass forwardly from the stack through said nip, said gate forming member comprising a generally cylindrical roll defining a central axis and an outer peripheral surface which is concentric to said central axis, said outer peripheral surface having a groove extending axially along the length thereof and which is positioned so as to generally oppose said nip, with said groove defining opposing parallel side walls and a bottom wall, and a bar disposed in said groove, with said bar being composed of a material having a higher coefficient of friction than the material of said roll and including parallel opposite side edges and being sized so that the opposite side edges are pressed into engagement with said opposing side walls of said groove and a portion of said bar extends beyond said peripheral surface of said nip, and means adjustably mounting said gate forming member to said frame so as to permit the dimension of said nip to be adjusted, and whereby the gate forming member may be adjustably positioned so that the lowermost sheet is free to pass through said nip without significant engagement with said bar and thus without significant frictional resistance while the sheet immediately above the lowermost sheet engages said bar and is frictionally engaged thereby.

2. The apparatus as defined in claim 1 wherein said means rotatably mounting said endless belt means includes a pair of spaced apart support shafts mounted for rotation about parallel axes and having said endless belt means entrained thereabout.

3. The apparatus as defined in claim 2 wherein said endless belt means comprises a plurality of endless belts, and a pair of aligned support rolls mounted on respective ones of said support shafts and mounting each of said endless belts, and a plurality of drive rolls mounted on each of said support shafts, with at least one of said drive rolls being positioned between adjacent endless belts, and with the diameter of said support rolls being less than the diameter of said drive rolls so that said drive rolls have an outer surface which is substantially coextensive with the outer surface of said endless belts.

4. The apparatus as defined in claim 3 wherein one of said support shafts is aligned with said cylindrical roll of said gate forming member so that the drive rolls on said one support shaft are aligned across the nip from said cylindrical roll.

5. The apparatus as defined in claim 1 further comprising sheet guide means positioned downstream of and in registry with said nip for guiding the sheets forwardly after advancing through said nip.

6. The apparatus as defined in claim 5 wherein said sheet guide means comprises a guide roller mounted for rotation about a fixed axis disposed parallel to said axes of said support shafts, with the upper portion of said guide roller being substantially coplanar with said upper run of said belt means and transmission means operatively connected between said drive means and said guide roller for rotating said guide roller at a peripheral speed corresponding to the speed of said endless belt means.

7. The apparatus as defined in claim 6 wherein said transmission means comprises a plurality of guide belts and rollers entrained about said one support roll and said guide roll, with said guide belts having an upper run which is substantially coplanar with said upper run of said endless belt means.

8. The apparatus as defined in claim 7 wherein said sheet guide means further comprises a clamping roller, and means mounting said clamping roller for free rotation about an axis parallel to the axis of said guide roller and so that said clamping roller rests upon the peripheral surface of said guide roller.

9. The apparatus as defined in claim 5 further including a sheet guiding member positioned downstream from said sheet guide means and said nip, said sheet guiding member having a downwardly inclined surface portion for engaging the leading edge of each delivered sheet and guiding the same to a predetermined area.

10. The apparatus as defined in claim 1 wherein said portion of said bar which extends beyond said outer peripheral surface includes a rearwardly facing edge surface which extends generally along a tangent to said outer peripheral surface.

11. The gate forming member as defined in claim 10 wherein said bar has a quadrilateral cross sectional configuration which comprises said parallel opposite side edges and inclined upper and bottom edges, and with one of said upper and bottom edges defining said edge surface, and whereby said bar may be removed and replaced in said groove so that the other of said upper and bottom edges defines said edge surface.

12. The apparatus as defined in claim 1 further comprising means adjustably mounting said gate forming member so as to permit the dimension of said nip to be adjusted and such that said gate forming member may be readily removed from the remainder of said apparatus.

13. The apparatus as defined in claim 12 wherein said apparatus further comprises a frame including a support bracket which is positioned above said nip, and said means adjustably mounting said gate forming member comprises a road fixed to said roll at a central portion thereof and such that the rod extends radially upwardly from said nip, and means interconnecting said rod to said support bracket so as to permit limited movement therebetween and to permit the dimension of said nip to be adjusted, and spring biasing means surrounding said rod for biasing said roll toward said nip and form permitting limited movement of said roll away from said nip and against the force of said spring biasing means.

14. The apparatus as defined in claim 1 further comprising sensing means for sensing the presence or absence of a sheet exiting said nip.

15. The apparatus as defined in claim 14 further comprising means operatively interconnecting said sensing means with said drive means so as to actuate said drive means when no sheet is sensed by said sensing means.

16. The apparatus as defined in claim 14 wherein said sensing means comprises a photocell.

17. The apparatus as defined in claim 14 wherein said sensing means stops said drive means from operating upon having sensed a predetermined number of sheets passing through said nip.

18. A gate forming member for use with an apparatus for serially feeding sheets in a forward direction from the bottom of a generally vertical stack of such sheets and comprising:

a generally cylindrical roll defining a central axis and an outer peripheral surface which is concentric to said central axis, said outer peripheral surface having a groove extending axially along the length thereof, with said groove defining opposing parallel side walls and a bottom wall, and

a bar disposed in said groove, with said bar being composed of a material having a higher coefficient of friction than the material of said roll and including parallel opposite side edges and being sized so that the opposite side edges are pressed into engagement with said opposing side walls of said groove and a portion of said bar extends beyond said peripheral surface, said portion of said bar which extends beyond said outer peripheral surface including an edge surface which extends generally along a tangent to said outer peripheral surface, and wherein said bar has a quadrilateral cross section configuration which comprises said parallel opposite side edges and inclined upper and bottom edges, and with one of said upper and bottom edges defining said edge surface, and whereby said bar may be removed and replaced in said groove so that the other of said upper and bottom edges defines said edge surface.

19. The gate forming member as defined in claim 18 wherein said roll is composed of a material having a coefficient of friction of about 0.15 to 0.35, and said bar is composed of an elastomeric material having a coefficient of friction of about 0.5 to 0.7.

20. The gate forming member as defined in claim 18 wherein said roll includes a threaded radial opening at a central position along its axial length, for facilitating the mounting of said roll.

21. The gate forming member as defined in claim 20 wherein said roll further includes mounting posts extending from opposite ends of said roll and with said mounting posts being coaxially aligned with said central axis.

22. An apparatus for serially feeding sheets in a forward direction from the bottom of a generally vertical stack of such sheets and comprising:

means for supporting the generally vertical stack of sheets and so that the stack defines a forward side composed of aligned forward edges of the sheets, and a bottom, said supporting means including endless belt means and means rotatably mounting said endless belt means so as to have an upper run positioned to extend across the bottom of said stack;

drive means for rotating said endless belt means so that said upper run moves in the forward direction;

a gate forming member positioned above said upper run of said belt means and adjacent the forward side of said stack and so as to define a nip which forms a gap between said gate forming member and said upper run for permitting the lowermost sheet of the stack to pass forwardly from the stack through said nip, said gate forming member comprising a generally cylindrical roll defining a central axis and an outer peripheral surface which is concentric to said central axis, said outer peripheral surface having a groove extending axially along the length thereof and which is positioned so as to generally oppose said nip, with said groove defining opposing parallel side walls and a bottom wall, and a bar disposed in said groove, with said bar being composed of a material having a higher coefficient of friction than the material of said roll and including parallel opposite side edges and being sized so that the opposite side edges are pressed into engagement with said opposing side walls of said groove and a portion of said bar extends beyond said peripheral surface at said nip and is spaced from said endless belt means, and whereby the lowermost sheet is free to pass through said nip without significant engagement with said bar and thus without significant frictional resistance while the sheet immediately above the lowermost sheet engages said bar and is frictionally engaged thereby, said portion of said bar which extends beyond said outer peripheral surface including an edge surface which extends generally along a tangent to said outer peripheral surface, and wherein said bar has a quadrilateral cross sectional configuration which comprises said parallel opposite side edges and inclined upper and bottom edges, and with one of said upper and bottom edges defining said edge surface, and whereby said bar may be removed and replaced in said groove so that the other of said upper and bottom edges defines said edge surface.