Document feed mechanism incorporating an idler wheel assembly

Abstract: A document feed mechanism includes a feed wheel (12) and a cooperating idler wheel (14) which is movable between active and inactive positions. The idler wheel (14) is rotatably mounted on one end (88-­ 3) of an arm (88) which passes through an elongated slot formed in support means (42,86) for a document track (28), the slot extending perpendicularly to the document track (28) and a pivot portion (88-1) of the arm (88) being slidably movable along the slot. A compression spring (74) biases the idler wheel (14) towards its inactive position with the arm (88) pivoting about a region of contact between the pivot portion (88-1) of the arm (88) and a closed end of the slot. A solenoid (60), when energized, moves the idler wheel (14) towards its active position against the bias of the compression spring (74), with the arm (88) pivoting about said region of contact. Documents of different thicknesses can be handled by the mechanism by virtue of the arm (88) being slidable along the slot.

Description: This invention relates to a document feed mechanism. The invention is concerned in particular with a document feed mechanism incorporating an idler wheel mechanism In the processing of financial documents, like cheques and deposit slips, for example, the documents are moved along a document track in the course of being moved to various processing stations within financial processing machines, like encoders and sorters, for example. In moving the documents, there is generally a feed wheel located on one side of the document track and an idler wheel located on the opposite side of the track. The feed wheel is generally rotated at a constant velocity, and when a document is located between the feed wheel and the idler wheel, the document is moved in a feeding direction along the track. In some feeding apparatuses, the idler wheel is always in contact with the feed wheel, waiting for a document to be moved therebetween so that the document can be fed further in the feeding direction. This type of apparatus causes excessive wear on both the feed and idler wheels. In other feeding apparatuses, the idler wheel is moved towards the feed wheel only when a document comes between the feed and idler wheels. One problem associated with known document feeders is that they must handle or move documents which vary in weight and thickness. Very often, the document feeders require adjustments to handle the various thicknesses of documents to be processed. These adjustments are, at times, expensive and time consuming, resulting in down time for the processing machine. WO-A-87/01104 discloses a feed wheel and idler wheel for moving a document vertically in a document track. The idler wheel is connected to actuator means by way of articulated arm members, and separate biasing means are provided for biasing the idler wheel into active and inactive positions with respect to the feed wheel. Such an arrangement is disadvantageously complex as regards construction, maintenance and paper-thickness compensation adjustments. It is an object of the invention to provide a document feed mechanism of the kind incorporating a feed wheel and a cooperating idler wheel movable between active and inactive positions, which mechanism is simple in construction and allows for ease of maintenance and adjustment and which can feed documents of different thicknesses without any adjustment of the mechanism being required. According to the invention there is provided a document feed mechanism including a document track mounted on support means, a feed wheel mounted on one side of said document track, drive means for rotating said feed wheel, an arm having first and second end portions and for moving an idler wheel mounted on said first end portion between active and inactive positions with respect to said feed wheel, resilient means for biasing said idler wheel towards said inactive position and actuator means for moving said idler wheel towards said active position against the bias of said resilient means, characterized in that said arm has a pivot portion between said first and second end portions which passes through an elongated slot formed in said support means and extending substantially perpendicularly to said document track, said resilient means biases said idler wheel towards said inactive position with said arm pivoting about a region of contact between said pivot portion and a closed end of said slot, and said actuator means when energized moves said idler wheel towards said active position with said arm pivoting about said region of contact, and said pivot portion is slidably movable along said slot when said idler wheel is in said active position. One embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which : Fig. 1 is a plan view of a processing machine in which a document feed mechanism according to this invention is used; Fig. 2 is an elevational view of a preferred embodiment of this invention, taken along the line 2-2 of Fig. 1, showing a mechanism for feeding documents along a document track, with the mechanism including an idler wheel which is shown in an active position relative to an associated drive wheel; Fig. 3 is a side view of a support bracket of the mechanism shown in Fig. 2, the view being taken along the general direction of line A in Fig. 2; and Fig. 4 is a plan view of the bracket shown in Fig. 3. Fig. 2 shows a preferred embodiment of a mechanism for feeding documents along a track, with the mechanism being designated generally as 10. The mechanism 10 has a feed or drive wheel 12 and an idler wheel 14 which are shown in a cooperating relationship. In order to orient the mechanism 10 in a typical environment, it is useful to look at Fig. 1. Fig. 1 is a plan view of a financial business machine 16 in which the mechanism 10 may be used. The machine 16, very generally, includes a hopper 18 for storing a stack of documents, jogger wheel 20, picker wheel 22, advance wheel 24, and stripper wheel 26. The function of the stripper wheel 26 is to singulate the documents so that only one document at a time is fed into the document track 28 which is comprised of upstanding walls 28-1 and 28-2. A sensor 30 is positioned along the document track 28 to detect document movement as will be described hereinafter. The mechanism 10 is used to drive or move a document 32 towards a conventional reader 34, encoder 36, endorser 37, and multi-pocket device 38 which are part of the machine 16. Suitable document feed rollers (not shown) are positioned along the document track 28 to feed the documents to the various components mentioned. A controller 40 is used to coordinate or control the activities of the machine 16. In the embodiment described, the encoder 36 indicates when a document is to be fed from the hopper 18, although the control, obviously, could be initiated elsewhere. When a document 32 is to be fed, a stepping motor (not shown) is energized to rotate the advance wheel 24. As a document is moved towards the sensor 30, the leading edge of the document 32 is used to actuate the mechanism 10 after a time delay. The sensor 30 is also used to make sure that a space exists between the trailing edge of one document 32 and the leading edge of a succeeding document 32 being fed in the document track 28. For example, if the sensor 30 does not detect a space between successive documents being fed within a predetermined time out, the controller 40 will shut down the machine 16 because this situation most likely indicates a document jam. Because these aspects of control are conventional, they need not be discussed in any further detail. In the embodiment described, the peripheral speed of the advance wheel 24 is about 89 centimetres per second, and the peripheral speed of the drive wheel 12 is about 127-140 centimetres per second. These speeds produce a feed rate of about 40 documents per minute. Naturally, other speeds could be used for different applications. The drive wheel 12 and the idler wheel 14 are referred to as "soft" drives. In other words, the drive wheel 12 will "slip" on a document 32 without abrading it while the document 32 is being held somewhat by the advance wheel 24 and the associated stripper wheel 26. The drive wheel 12 and the idler wheel 14, alluded to with regard to the discussion of Fig. 1, are part of the mechanism 10 (Fig. 2) for feeding documents along the document track 28. The mechanism 10 includes a frame 42 with the document track 28 being mounted thereon. The drive wheel 12 is mounted on an axle 44 which is upstanding from the frame 42 and is secured thereto. The drive wheel 12 has an annular groove on its periphery to receive an "O"-type or circulr driving belt 46. Any convenient means may be used to drive or rotate the drive wheel 12. For example, in the embodiment described, the drive wheel 12 is rotated by a motor 48 (Fig. 1) which also rotates a fan 50 to cool the machine 16. The motor 48 has an output pulley 52 which receives the driving belt 46. The mechanism 10 also includes the idler wheel 14 and moving means designated generally as 54 for moving the idler wheel 14 between a home or inactive position, in which the idler wheel 14 is spaced from the drive wheel 12, and an active position as shown in Fig. 2, in which a document 32 is gripped between the idler wheel 14 and the drive wheel 12. The moving means 54 includes an arm 88 which has a pivot portion 88-1, a lower end portion 88-2, and an upper end portion 88-3, with the pivot portion 88-1 being located between the lower and upper end portions 88-2, 88-3. The idler wheel 14 is rotatably mounted on the upper end portion 88-3 of the arm 88 while the lower end portion 88-2 is pinned to an operating plunger 58 of a solenoid 60. By means to be described later, the idler wheel arm 88 is mounted so as to enable the pivot portion 88-1 of the arm 88 to move in opposed directions along a line which is substantially perpendicular to the said document track 28. The solenoid 60, serves as an actuator for moving the idler wheel 14 from its inactive position to its active position shown in Fig. 2. One of the features of the mechanism 10 is that it utilizes a low cost solenoid which does not have an internal spring to return the operating plunger to an inactive position. In the mechanism 10, a compression spring 74 is used to move the operating plunger 58 of the solenoid 60 to an inactive position in which it abuts against a rubber bumper 82. Another feature of the mechanism 10 is that the mounting means to be described later for the idler wheel arm 88 provides a "floating" mount. This mount enables the mechanism 10 to accommodate the tolerances expected in the mechanism 10. These tolerances include the anticipated wear on the idler and drive wheels 14 and 12 and the range of documents expected to be transported by the mechanism 10. The idler wheel 14 forms part of an idler wheel assembly designated generally as assembly 84. The assembly 84 includes a bracket or frame designated generally as 86 which enables the assembly 84 to be secured to the frame 42 of the machine 16. It should be understood that the function of the mounting means is to enable the pivot area 88-1 to move along a line which is perpendicular to the document track 28. The idler wheel assembly 84 may be considered as a separate article of manufacture to enable it to be incorporated into the machine 16. The assembly 84 is detachably secured to the mechanism 10 by having its bracket 86 secured to the frame 42 by fasteners 90 so that the idler wheel 14 is positioned in operative relationship with respect to the drive wheel 12. Referring now additionally to Figs. 3 and 4, the bracket 86 of the mechanism 84 includes a side plate 86-1 and a top plate 86-2, with the bracket 86 having the general "L"-shaped configuration shown in Figs. 2-4. The side plate 86-2 has a projection 92 extending therefrom to enable the compression spring 74 to be mounted and retained thereon. The top plate 86-2 functions as a mounting flange to enable the assembly 84 to be secured to the frame 42 of the machine 16. The top plate 86-2 also has an elongated slot 94 formed therein, with the slot 94 extending perpendicularly relative to the document track 28. The arm 88 passes through the slot 94 which is so dimensioned that the pivot portion 88-1 of the arm 88 is slidably movable along the slot 94. The slot 94 is aligned (in a vertical direction) with the longitudinal axis of the operating plunger 58 of the solenoid 60. The side plate 86-1 has a hole 61 therein to receive the solenoid 60. The lower end portion 88-2 of the arm 88 (as viewed in Fig. 2) is pivotally joined to the operating plunger 58 of the solenoid 60. The arm 88 has a single recess 96 at the pivot portion 88-1 thereof to receive one end of the compression spring 74, with the other end of the spring 74 being mounted on the projection 92. The spring 74 and the slot 94 in the frame 86 provide a mounting means for mounting the arm 88 at the pivot portion 88-1 to enable the pivot portion 88-1 to move along the slot 94 in a direction towards or away from the document track 28, this direction being substantially perpendicular to the track 28. The movement of the idler wheel arm 88 to the inactive position is limited by the action of the operating plunger 58 of the solenoid abutting against the bumper 82 when the solenoid 60 is de-energized. When the solenoid 60 is actuated or energized, the idler wheel arm 88 pivots about a region of contact between the pivot portion 88-1 of the arm 88 and the closed end 94-1 of the slot 94, against the action of the spring 74, so as to move the idler wheel 14 towards the document 32. The controller 40 energizes the solenoid 60 at the appropriate time to make sure that the document 32 is between the idler and drive wheels 14 and 12 when the solenoid 60 is energized. This prevents damage to the leading edge of the document 32 as it encounters the idler and drive wheels 14 and 12. When the solenoid 60 is in the active condition shown in Fig. 2, it has essentially bottomed out; however, the idler wheel 14 is resiliently urged into engagement with the document 32 due to the action of compression spring 74. It should be understood that the idler wheel arm 88 tends to "float" in that it does not necessarily contact the closed end 94-1 of the slot 94 when the solenoid 60 is in its active condition. In other words, the compression spring 74 pushes the arm 88, and the idler wheel 14 resiliently contacts the document 32. Notice also, if a thick document 32 were encountered, the idler wheel 14 would be pushed away from the drive wheel 12 to accommodate the thick document 32, with the pivot area 88-1 of the arm 88 sliding along the slot 94. When the solenoid 60 is de-energized, the compression spring 74 pushes the lower end 88-2 of the arm 88 away from the side plate 86-1 so as to pivot the arm 88 about the region of contact between the pivot portion 88-1 of the arm 88 and the closed end 94-1 of the slot 94 and thereby return the idler wheel 14 to its inactive condition. This pivotal movement of the arm 88 is terminated when the operating plunger 58 abuts against the rubber bumper 82. When the idler wheel arm 88 is floating as described, several benefits accrue. Because it is the spring 74 which moves the arm 88, the pressure of the idler wheel 14 on the document 32 appears to be more constant and less likely to damage a document 32. As the drive and idler wheels 12 and 14 tend to wear, no adjustment is necessary for the mechanism 10 because some wear was anticipated in designing the mechanism 10. Also, as previously indicated, thick and thin documents 32 can be handled by the mechanism 10. Advantages of the assembly 84 is that it is easy to manufacture and that the tolerances for which the assembly 84 is to respond are easy to set.

Claims: A document feed mechanism including a document track (28) mounted on support means (42,86), a feed wheel (12) mounted on one side of said document track, drive means (46,48) for rotating said feed wheel (12), arm (88) having first and second end portions (83-3,88-2) and for moving an idler wheel (14) mounted on said first end portion (88-3) between active and inactive positions with respect to said feed wheel, resilient means (74) for biasing said idler wheel (14) towards said inactive position and actuator means (60) for moving said idler wheel towards said active position against the bias of said resilient means, characterized in that said arm (88) has a pivot portion (88-1) between said first and second end portions (88-3,88-2) which passes through an elongated slot (94) formed in said support means and extending substantially perpendicularly to said document track (28), said resilient means (74) biases said idler wheel (14) towards said inactive position with said arm (88) pivoting about a region of contact between said pivot portion (88-1) and a closed end (94-1) of said slot (94) , and said actuator means (60) when energized moves said idler wheel (14) towards said active position with said arm (88) pivoting about said region of contact, and said pivot portion (88-1) is slidably movable along said slot (94) when said idler wheel (14) is in said active position. A mechanism according to claim 1, characterized in that said pivot portion (88-1) is slidably movable along said slot (94) against the bias of said resilient means (74). A mechanism according to claim 1 or 2, characterized in that said resilient means comprises a compression spring (74) arranged to engage a portion of said arm (88) between said pivot portion (88-1) and said second end portion (88-2). A mechanism according to claim 3, characterized in that said actuator means comprises a solenoid (60) having an operating plunger (58) connected to said second end portion (88-2) of said arm (88), said solenoid having no return spring therein and said compression spring serving to move said operating plunger to a home position while simultaneously moving said idler wheel to said inactive position when said solenoid is de-energized. A mechanism according to claim 4, characterized in that said plunger (58) is arranged to abut against rubber stop means (82) for the purposes of terminating movement of said plunger to said home position. A mechanism according to any one of claims 1 to 4, characterized in that said arm (88), said resilient means (74) and said actuator means (60) are mounted on a bracket (86) which is detachably secured to a support frame (42) for said document track (28), said slot (94) being formed in said bracket. A mechanism according to claims 4 and 6, characterized in that rubber stop means (82) are mounted on said bracket (86), said plunger (58) being engaged to abut against said stop means for the purpose of terminating movement of said plunger to said home position. A mechanism according to any one of the preceding claims, characterized in that, upon said idler wheel (14) being moved to said active position, said pivot portion (88-1) is movable along said slot (94), the amount of such movement being dependent on the thickness of a document (32) positioned between the feed and idler wheels (12,14). A mechanism according to any one of the preceding claims, characterized in that said moving means includes controller means (40) and sensor means (30) coupled to said controller means, with said sensor means being positioned along said document track (28) to provide an output signal when a document (32) is positioned between said feed wheel (12) and said idler wheel (14), said controller means being effective to energize said solenoid (60) upon receiving said control signal to move said idler wheel towards said active position.

Inventors: GROOT WILLIAM PETER, PETERSEN BORGE, GROOT, WILLIAM PETER, PETERSEN, BORGE
Applicants: NCR INT INC, NCR INTERNATIONAL INC.
Application year: 1989
Main classification: B65H5
IPC codes: B65H5