US3734490A

US3734490A - Document feeding mechanism

Info

Publication number: US3734490A
Application number: US00202936A
Authority: US
Inventors: J Parks
Original assignee: Individual
Current assignee: National Computer Systems Inc
Priority date: 1971-11-29
Filing date: 1971-11-29
Publication date: 1973-05-22
Anticipated expiration: 1990-05-22

Abstract

An apparatus for successively feeding documents, such as sheets or cards, edgewise from a stack of the documents. A flexible belt movable about a pair of spaced-apart wheels overlies the stack of documents with the belt normally moving above the top document in the stack. An idler wheel is positioned between the wheels inside of the belt''s path and is movable up and down to force the belt downward to engage the top document in the stack and move it edgewise from the stack.

Description

0 Q wiiiie States WERE 1 91 1 11 3,734,498 Parks 1 51 May 22, 1973 54 DOCUMENT FEEDING MECHANISM 2,966,065 12/1960 Renner ..198/202 x [76] Inventor: James D. Parks, P. O. Box 30, Iowa City Iowa 52240 Primary Examiner-Evon C. Blunk Assistant Examiner-Bruce H. Stoner, Jr. Filed: 29v 1971 Att0rney- Haven E1 Simmons and James C. Nemmers [21] App]. N0.: 202,936

57 ABSTRACT [52] U.S. C1 ..271/34, 271/49 An pp r f r sively feeding documents, 51 1m. (:1 ..B65h 3/04, B65h 9/16 such as sheets or cards, edgewise from a stack of the [58] Field of Search ..271/34, 35, 49,59; documents- A flexible belt movable about a pair of 198/202; 226/180 spaced-apart wheels overlies the stack of documents with the belt normally moving above the top docu- [56] References Cited ment in the stack. An idler wheel is positioned between the wheels inside of the belts path and is UNITED STATES PATENTS movable up and down to force the belt downward to 3,485,489 12/1969 Lindquist ..271/34X engage the top document in the stack and move it 3,108,801 10/1963 Van Dalen edgewise from the stack.

608,486 8/1898 Sletto .1 3,549,003 12/1970 Jacobson ..198/208 X 6 Claims, 5 Drawing Figures BACKGROUND OF THE INVENTION The invention relates to feeding mechanisms and more particularly to an improved mechanism for feeding the documents one-at-a-time in edge alignment from an input stack despite random variations in the size, weight, thickness or surface characteristics of the documents fed.

In recent years, there has been a tremendous increase in the use of data processing equipment, such as computers, electronic scanning devices, automatic counting mechanisms, etc. The use of such equipment and the increasing demand for higher processing speeds has presented the problem of mechanically handling the data-containing documents throughout their processing, and, there have been developed a number of methods and devices particularly for feeding the documents into the data processing equipment. Many of these feeding devices have been developed for specific types of data processing equipment and are not readily adaptable for universal use. Also, because of the high rates of speed at which data processing equipment operates, the prior art feeding devices have been relatively complex and have, therefore, been costly to design and have presented maintenance problems. For example, one of the commonly used feeding mechanisms for document scanning devices is a tractor type mechanism such as that shown in U.S. Pat. No. 3,485,489 issued to E. F. Lindquist on Dec. 23, 1969. The document feeding mechanism shown in this patent works very well, but it is relatively complex and thus expensive, and because of its design, the mechanism must be disassembled in order to replace the belt. Therefore, a simpler and less expensive mechanism which would allow easier belt replacement would be desirable.

SUMMARY OF THE INVENTION The invention provides an improved feeding mechanism for feeding documents one-at-a-time from an input stack. The mechanism of the invention includes a pair of wheels rotatable about fixed spaced-apart parallel axes, which wheels serve to drive an endless belt that engages them. The wheels and belt overlie the top of the document stack, and a third idler wheel positioned between the other wheels inside of the belt is movable up and down to force the belt into and out of engagement with the top document on the stack. By using crowned drive wheels, the need for any side guide bearings is eliminated and a document can be fed quickly and accurately in a forward direction and with a side force also exerted on the document to keep it in proper alignment against a side guide plate. With this simple arrangement, the belt can easily be slipped off the drive wheels and a new one slipped on in a matter of a few seconds, thus greatly simplifying the replacement of belts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a fragmentary side elevation view ofa feeding apparatus embodying the invention;

FIG. 2 is a top or plan view of the apparatus of FIG. 1;

FIG. 3 is an enlarged fragmentary view of a portion of the mechanism of FIG. 2 with the belt broken away to show the idler and drive wheels;

FIG. 4 is an enlarged fragmenatry side view further illustrating the feed mechanism; and

FIG. 5 is a sectional view taken on the line 5-5 of FIG. 4 and showing the mechanism for operating the pick wheel.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION Referring now to the drawings, and particularly to FIG. 1, the invention is illustrated in connection with a document scanning apparatus, only a portion of which is shown. Such apparatus are well-known to those skilled in the art and the portion shown is for the purpose of illustrating the invention. Such an apparatus includes an input hopper 10 for receiving and supporting a stack of documents 12 which are to be fed into the document scanning apparatus. The hopper 10 includes a vertically movable document supporting table 14 which in turn is mounted on a rod 16 that is operated by any suitable means, hydraulic, pneumatic, mechanical, electrical, or any combination thereof. Movement of the support platform 14 is for the purpose of maintaining the top of the stack 12 at a nearly constant level as the documents are fed into the apparatus. Various means for accomplishing this are well known to those skilled in the art. The input hopper 10 also includes a side wall 18 and a front wall 20 against which the documents in the stack 12 can be substantially aligned sideways and edgewise.

Forwardly of the input hopper 10 is the main table 22 which supports the individual documents as they are passed under a scanning head or heads, 24, the documents being moved along said table by means of pairs of synchronized drive wheels 26. The top edge 28 of the table just forwardly of the document stack 12 is at a level that coincides with the level of the top of the stack 12 so that a document moved off the top of stack 12 will then be supported on the table 22. To guide the documents along a straight path there is provided along one edge of the table 22 a side guide wall 30 which will assure that each document is in proper registry as it passes beneath the scanning heads 24. In most data processing machines, and especially in document scanners, it is extremely important that the proper alignment of the document be maintained while it is passing through the processing means such as the scanning head 24. It is, therefore, important that as each document is fed from the top of the stack 12 onto the table 22 that it be biased against the side wall 30 and remain against that wall throughout its travel through the processing area. Thus, one of the functions of the document feeding mechanism is to assure not only that each document is fed individually from the top of stack I2 but that each document is fed so that its edge engages and is guided along the side guide wall 30.

The novel document feeding mechanism of the invention is indicated in the drawings generally by the reference numeral 32. The feeding mechanism 32 includes a driving wheel 34 rotatably mounted on a shaft 36 that is adjustably secured to the side wall 30. The axis of shaft 36 is perpendicular to the side wall 30 and parallel to the table 22. Spaced upstream from the the document stack 12. As indicated, both the drive wheel 34 and idler wheel 38 are mounted so that they can be adjusted within a limited distance to assure proper belt tension and also proper belt alignment. As best seen in FIG. 3, both the drive wheel 34 and idler wheel 38 are crowned so that the belt 42 which engages the two wheels will center itself on the wheels throughout all of the speed ranges that the belt is driven. The drive wheel 34 may be driven in any suitable manner such as by a belt 44 which interconnects a pulley 46 affixed to shaft 36 and a power means (not shown).

As best seen in FIG. 4, idler wheel 38 overlies the document stack 12 whereas drive wheel is shown as overlying the table 22 near the edge 28. Positioned between the drive wheel 34 8nd the idler wheel 38 is a third wheel termed a pick wheel 48. Pick wheel 48 is not power driven and as shown in FIG. 3 is mounted for rotation about a shaft 50. As best illustrated in FIG. 5, shaft 50 is not fixed but extends through an opening 52 in the side wall 30 and is pivotally connected behind the side wall 30 on a pivot mount 54. The outermost end of shaft 50 is pivotally connected to the operating arm 56 ofa voice coil solenoid 58 which is mounted on the rear side of the side wall 30.

With the foregoing described mounting arrangement for the shaft 50, the pick wheel 48 is held normally in a position where it is only in slight contact with the belt 42. Since the pick wheel 48 is freely rotatable about the shaft 50, it will be continuously driven as the belt 42 follows its endless path defined by the drive wheel 34 and idler wheel 38. In this position, the axis of the shaft 50 is substantially parallel to the

shafts

36 and 40. Also, with the pick wheel in its nurmal position, the belt 42 will be moving along its path at a distance above the uppermost document in the document stack 12. When it is desired to feed a document from the top of stack 12, the voice coil solenoid 58 is energized by command of a computer or other suitable control device, by manual operation or it may be cyclically controlled in any suitable manner. The manner of controlling the voice coil solenoid is not within the scope of the invention and many such means are well known to those skilled in the art. However, when the solenoid 58 is energized, the operating arm 56 will be moved upwardly forcing the pick wheel 48 downwardly. The pivot mounting 54 for shaft 50 is such that when movement of the operating arm 56 is upward, the pick wheel 48 will not only be moved downwardly but also forwardly and slightly toward the drive wheel 34. In its pick" position, the shaft 50 will not be parallel to

shafts

36 and 40 shaft 50 and wheel 48 will be in the positions shown in FIG. 3 and in the dotted lines of FIG. 4, but the angle of shaft 50 is exaggerated in order to better illustrate the fact that it is not parallel when in the-pick position. When shaft 50 is in the pick position, the belt 42 will be forced downwardly into engagement with the uppermost document in the document stack 12. When the belt 42 is operating in the direction of the arrow of FIG. 4, the document will be moved off the top of the stack 12 since the coefficient of friction between the document surface and the belt 42 is greater than the coefficient of friction between the documents themselves. If the pick wheel 48 is returned to its normal position by action of the solenoid 58 becoming de-energized, a single document will be fed forwardly onto the table 22. I prefer, however, to provide a retard plate 60 along the edge 28 of table 22 which plate is made of a material having a coefficient of friction lower than that of belt 42 but higher than that of the document surface. Thus, if more than one document should be picked up and moved off the top of the document stack, only a single document will be fed onto the table 22 since any subsequent document or documents will be retarded by the plate because of the relative friction. A document fed onto table 22 will be picked up by the drive wheels 26 and moved along the table 22.

T o assure that the document fed onto the table 22 also is in proper alignment with its edge at all times engaging the side wall 30, the document must be biased toward side wall 30 as it is fed from the document stack 12 onto the table 22. This is accomplished with the feeding mechanism 32 of the invention by the mounting of the shaft 50. As previously described, when the pick wheel 48 is moved from its normal position to a pick" position, the shaft 50 not only moves the pick wheel 48 downwardly but also forwardly. This causes the pick wheel 48 to be at a slight angle with the path of the belt 42 which will move the belt 42 axially on

wheels

34 and 38 and thus toward the side wall 30. Movement of the belt toward side wall 30 is preferably limited by stops 62 which are positioned on the inside surface of side wall 30 so that they will be engaged by the belt 42 as it moves axially. This limited movement of the belt 42 during the pick mode is sufficient to assure that a document is in proper alignment with its edge engaging the side wall 30. The larger the angle of the pick wheel shaft 50 relative to the

shafts

36 and 40 during the pick mode, the faster the belt 42 is moved toward the side wall 30. As the belt 42 engages the stops 62, it is also slightly compressed. Then, when the pick wheel 48 returns to its normal position, this compression along with the crown of the

wheels

34 and 38 will immediately return the belt to its normal position centered on the

wheels

34 and 38. The movement of the belt toward the side wall 30 and its return to the normal position occurs at an extremely fast rate. This is necessary since documents are commonly fed at speeds in excess of 300 documents per minute. It has been found that the feeding mechanism of the invention is extremely capable and will operate almost trouble free at these high rates of feeding. The mechanism 32 is obviously extremely simple and because of its extreme simplicity requires almost little or no maintenance. Belt wear in feeding mechanisms of this type is a concern since the belts are normally of a relatively thick and soft material which wears quite rapidly. I-Iowever, to replace a belt in the feeding mechanism 32 of the invention, it is only necessary to slip belt 42 from the drive wheel 34 and idler 38 and to position a new belt on the wheels. If necessary, adjustments are easily and quickly made in the

wheels

34 and 38 to compensate for variance in belts and belt tensions.

The operation of the feeding mechanism 32 should be evident from the foregoing description. Its operation and its construction is extremely simpie, thus reducing both initial and maintenance costs. The feeding mechanism of the invention has been described in a single preferred embodiment and illustrated in connection with a data processing machine of the document scanning type. It will be obvious to those skilled in the art, however, that the feeding mechanism has application in almost any situation where rapid successive feeding of documents or cards of any type is a necessary function. It will be further obvious to those skilled in the art that various revision and modifications can be made in the embodiment disclosed herein without departing from the spirit and scope of the invention. It is my intention, therefore, that all such revisions and modifications to the preferred embodiment disclosed herein and which are obvious to those skilled in the art will be included within the scope of the following claims.

I claim:

1. An apparatus for feeding successive documents endwise from a stack of said documents onto a document supporting surface adjacent the lead edge of the documents and along a path defined by a side edge guide, said apparatus comprising a first crowned wheel mounted for rotation about an axis parallel to the lead edge of the documents and generally overlying said stack of documents, a second crowned wheel mounted for rotation about an axis spaced horizontally from and parallel to said first axis, means to drive one of said wheels, an endless flexible belt mounted on said wheels for movement about an endless path normally defined by said wheels, and a third wheel mounted for rotation about an axis not parallel to the axes of said first and second wheels and lying inside of the path of said endless belt, said third wheel being movable downwardly to deflect said belt downwardly and sideways from its normal path and into engagement with the top document in said stack thereby to move said document onto said document supporting surface and toward said edge guide, and means to controllably move said third wheel to cause deflection of said belt at selected times.

2. The apparatus of claim 1 in which the wheel farthest downstream is the drive wheel.

3. The apparatus of claim 1 in which the axis for said third wheel is pivotally mounted to provide for movement of said third wheel upwardly and downwardly as the axis pivots, the end of said axis opposite said wheel being operatively connected to said means to controllably move said third wheel.

4. The apparatus of claim 1 in which the axis for each of said wheels is supported at one end only, thereby providing for complete removal of said belt from said wheels by disengaging said belt from said wheels while movint it away from the supported ends thereof.

5. The apparatus of claim 1 in which the axes of said first and second wheels are movable within a limited range to provide for adjustment of the tension and tracking of said belt.

6. The apparatus of claim 1 in which the axis of said third wheel is positioned so that said third wheel is in engagement with said belt at all times throughout the range of movement of said third wheel axis.