Document feed apparatus having a retard roller.

Abstract: An incremental motion mechanism (10) which uti­ lizes first and second one-way clutches (44, 46) attached to the output shaft (48) of the mechanism. The first one-­ way clutch (44) is used to prevent back up of the output member, while the second one-way clutch (46) is used to incrementally rotate the output shaft (48). Actuating means (52, 56) operated under the control of a controller (24) are used for adjusting the extent of rotation of the output shaft (48). The mechanism may be used in a docu­ ment feeding apparatus having a driven feed roller (26) and a retard roller (28) arranged in operative engagement with sort feed roller (26), wherein said retard roller (28) is mounted on the output shaft (48) for rotation therewith.

Description: This invention relates to document feed apparatus of the kind having a feed roller, driving means for rotating the feed roller, and a retard roller which cooperates with the feed roller for the purpose of preventing the feeding of two or more documents simultaneously. In a known apparatus of the kind specified, the retard roller is stationary. A disadvantage of this known apparatus is that, because the feed roller is driven, wear is experienced on that part of the periphery of the retard roller which is in cooperative relationship with respect to the feed roller. In European patent application No. EP-A-0 190 573 there is disclosed an apparatus of the kind specified in which the retard roller is continuously driven. This further known apparatus has the disadvantage that a significant amount of additional power is required to drive the retard roller continuously. In US patent No. 3,636,781 there is disclosed a data processing system in which data is recorded and played back in incremental fashion. The system includes an incremental motion mechanism for imparting incremental rotation to a shaft. A plurality of undirectional clutches are operatively coupled to the shaft such that the shaft is rotatable in one direction only relative to the clutches. Drive means is coupled to one of the clutches to incrementally drive the shaft in one direction while the outer housing of a further clutch is maintained stationary to prevent backlash of the shaft. An object of the present invention is to provide a document feed apparatus of the kind specified which overcomes the above mentioned disadvantages in a simple and effective manner. According to the present invention there is provided apparatus for feeding documents, having a feed roller, driving means for rotating said feed roller, and a retard roller mounted on a shaft located in a frame, said retard roller being arranged in cooperative relationship with respect to said feed roller to prevent more than one document at a time from passing between said feed roller and said retard roller, characterized in that said shaft is driven by an incremental motion mechanism including a first one-way clutch secured to said shaft and said frame to permit said shaft to rotate only in a first direction, a second one-way clutch, secured to said shaft and permitting said shaft to rotate only in said first direction relative to said second clutch, actuation means secured to said second clutch for rotating said second clutch in said first direction from a home position relative to said frame whenever said actuation means is energized, and means for returning said second clutch to its home position whenever said actuation means is de-energized, whereby said shaft is rotated incrementably whenever said actuation means is energized. Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a general schematic diagram showing a document feeder apparatus in a typical environment, with the incremental motion mechanism of this invention being included in the document feeder; Fig. 2 is a diagramatic view, in perspective, of one embodiment of this invention, showing the incremental motion mechanism in a typical environment; and Fig. 3 is a diagramatic view, taken along the line 3-3 of Fig. 2 to show a second embodiment of this invention. Fig. 1 is a general schematic diagram showing a typical environment in which the incremental motion mechanism 10 (Fig. 2) of this invention may be used. The environment shown in Fig. 1 may be a business machine, like an encoder 12, which performs the function of printing data on documents, like checks, for example. Documents to be processed are stored in a stack 14, and they are moved from the stack 14 to a document track 16 by a document feeder 18. Once the documents are in the document track 16, they are moved along therein to a utilization device 20 by a conventional moving means 22 under the control of a controller 24. The utilization device 20 may be an encoder or sorter, for example, depending upon the particular business machine being discussed. The incremental motion mechanism 10, hereinafter referred to as mechanism 10 (Fig. 2), is part of the document feeder 18 shown in Fig. 1. The document feeder 18 includes the feed roller 26 and the stripper or retard roller 28 which provide the function of feeding only one document, like 30, at a time, into the document track 16. As shown in Fig. 2, the feed roller 26 is mounted on a shaft 34 which is rotatably mounted in the frame 36. The feed roller 26 is rotated at a constant velocity in a clockwise direction (as viewed in Fig. 2) by a motor or drive 38 which is under the control of the controller 24. The retard roller 28 is rotatably mounted in the frame 40 which is generally "C"-shaped, as shown in Fig. 2. The retard roller 28 and the feed roller 26 each have a resilient layer on the associated periphery thereof, and these rollers are spaced apart a distance which permits only one document, like 30, to pass therebetween. The retard roller 28 is normally held stationary by the mechanism 10; however, it is incrementally rotated, periodically, to prevent a wear line from developing on the periphery of the retard roller 28 due to the feed roller 26 constantly rotating against it. If two documents, like 30 and 32, approach the nip between the feed and retard rollers 26 and 28, the document 32 is held by the retard roller 28, while the feed roller 26 moves the document 30 in the direction of arrow 42 into the document track 16. The mechanism 10 also includes one-way clutches 44 and 46 which are secured to the shaft 48 as shown in Fig. 2. The shaft 48 is rotatably mounted in the frame 40, and the retard roller 28 is fixed to the shaft 48 to rotate therewith. The clutches 44 and 46 are conventional one-way clutches which are shown schematically in Fig. 2 to simplify the drawing; however, a conventional clutch, such as clutch #RC-040708, which is manufactured by Torrington, for example, may be used. The clutch 44 is installed so that its housing is secured to the frame 40 by a bracket 50, and its output member is secured to the shaft 48, with the clutch 44 permitting rotation only in a clockwise direction as viewed in Fig. 2. In this regard, the clutch 44 functions as an anti-back-up element to prevent the retard roller 28 from rotating in a counter-clockwise direction. The second clutch 46 has its output member secured to the shaft 48, and its housing has an actuating means secured thereto as shown in Fig 2. The function of the actuating means is to periodically rotate the retard roller 28 in a clockwise direction so as to present a new portion of the periphery of the retard roller 28 to the feed roller 26 and thereby minimize wear on the retard roller 28. The actuating means includes an actuating lever 52, a tension spring 54, a solenoid 56, and the controller 24. The actuating lever 52 has one end secured to the housing of the clutch 46, with the free end thereof being resiliently biased to a home position by a tension spring 54. When the solenoid 56 is energized by the controller 24, it pulls the free end of the actuating lever 52 in a clockwise direction, as viewed in Fig. 2, to thereby rotate the shaft 48 with the retard roller 28 thereon in a clockwise direction. The incremental rotation may be a fixed amount if the solenoid 56 is of fixed "throw" type, or the solenoid may be of a variable type to provide a variety of incremental rotations or "throws" under the control of the controller 24. Notice from what has been described in the previous paragraph that the clutch 44 prevents the retard roller 28 from backing up, while the clutch 46 is used to incrementally rotate the retard roller 28 in the clockwise direction. With this construction, there is no "back-up" as discussed in the background of the invention. Notice, also, how easily the indexing of the retard roller 28 is effected. Another feature of this invention is the ease with which the "throw" of the actuating means may be adjusted. In this regard, Fig. 3 shows a second embodiment of the invention which is also shown in diagrammatic form, with the apparatus being designated generally as 58. The apparatus 58 includes the shaft 48 which supports the retard roller 28 shown in Fig. 2, and it also includes the second one-way clutch 46 which operates as previously described. The actuator arm 60 is secured to the housing of the clutch 46 so that when the actuator arm 60 is moved in a clockwise direction (as viewed in Fig. 3) through an arc, the shaft 48 is moved, correspondingly, through a similar arc. The apparatus 58 includes means for adjusting the extent of rotation of the one-way clutch 46; this means includes a resilient means or spring 62 which is used to bias the actuator arm 60 to the home position shown in Fig. 3. The adjustment means mentioned also includes a first actuator or solenoid 64 which has an operating link 66 extending therefrom as shown. The distant end 68 of the link 66 is slidably mounted in a radially-aligned slot 70 in the actuating arm 60 so as to change the effective moment arm of the actuating arm 60 as will be described hereinafter. The operating link 66 is pulled to a home position relative to the slot 70 by a spring 72, and it is pulled to the active position shown, by a second adjustment means or operating link 74 associated with a second actuator or solenoid 74. A suitable fastener 71, positioned in the slot 70, provides an adjustable stop for the location of the home position for the link 66. The second link 74 has its distant end pivotally coupled to the operating link 66 between the ends of this link 66. When the solenoid 76 is energized by the controller 24, the link 74 is pulled into the body of the solenoid 76, to thereby move the operating link 66 towards the right side of the slot 70 (as viewed in Fig. 3); this action changes the effective moment arm of the actuator arm 60 and thereby decreases the extent of rotation or pivoting of the actuating arm 60 for the same linear pull by solenoid 64. However, when the link 66 is moved to the right of the slot 70 (as viewed in Fig. 3), the torque produced by the actuator arm 60 increases compared to the situation in which the link 66 is located at the left side of the slot 70. The actuating arm 60 is held in the home position by the spring 62 and the stroke adjustment screw and lock nut combination 78 shown in Fig. 3. The actuating arm 60 is moved away from the home position by the solenoids 64 and 76 as previously described. These solenoids 64 and 76 may be conventional two step solenoids which provide additional flexibility to incrementally move the actuating arm 60 different degrees of rotation under the control of the controller 24.

Claims: 1. Apparatus for feeding documents, having a feed roller (26), driving means (34,38) for rotating said feed roller, and a retard roller (28) mounted on a shaft (48) located in a frame (40), said retard roller being arranged in cooperative relationship with respect to said feed roller to prevent more than one document at a time from passing between said feed roller and said retard roller, characterized in that said shaft (48) is driven by an incremental motion mechanism including a first one-way clutch (44) secured to said shaft (48) and said frame (40) to permit said shaft to rotate only in a first direction, a second one-way clutch (46), secured to said shaft and permitting said shaft to rotate only in said first direction relative to said second clutch, actuation means (56;64,66,74,76) secured to said second clutch for rotating said second clutch in said first direction from a home position relative to said frame (40) whenever said actuation means is energized, and means (54;62) for returning said second clutch to its home position whenever said actuation means is de-energized, whereby said shaft is rotated incrementably whenever said actuation means is energized. 2. Apparatus according to claim 1, characterized in that said actuation means (56;64,66,74,76) includes an actuator arm (52;60) which is secured to said second one-way clutch (46) to rotate said second one-way clutch (46) in said first direction. 3. Apparatus according to claim 2, characterized in that said actuation means includes adjustment means (64,66,72,74,76) for adjusting the extent of rotation of said second one-way clutch (46). 4. Apparatus according to claim 3, characterized in that said actuator arm (60) has an effective moment arm and said adjustment means (64, 66, 72, 74, 76) includes first operating means (64, 66) for moving said actuator (60) arm from said home position through a predetermined arc when said first operating means (64, 66) is actuated. 5. Apparatus according to claim 4, characterized in that said adjustment means (64, 66, 72, 74, 76) also includes second operating means (74, 76) for changing the length of said effective moment arm of said actuating arm (60). 6. Apparatus according to claim 5, characterized in that said first (64, 66) and second operating means (74, 76) are coupled together and include first and second actuators (64, 76), respectively. 7. Apparatus according to claim 6, characterized in that said actuating arm (60) has a raidally-aligned slot (70) therein and, said first operating means (64, 66) includes a first link (66) having one end secured to said first actuator (64) and the other end thereof pivotally secured to said actuator arm (60) at said radially-aligned slot (70) therein. 8. Apparatus according to claim 7, characterized in that said second operating means (74, 76) includes a second link (74) having one end secured to said second actuator (76) and the other end thereof pivotally secured to said first link (66) between the ends of said first link (66). 9. Apparatus according to claims 6, 7 or 8, characterized in that said actuation means includes a controller (24), and said first and second actuators (64, 76) are controlled by said controller.

Inventors: REID, BRUCE, ARNOLD
Applicants: NCR CORPORATION
Application year: 1988
Main classification: F16H29
IPC codes: B65H3, F16H31, F16H29, B41J13