US3908297A

US3908297A - Keyboard operator sheet holding and feeding device

Info

Publication number: US3908297A
Application number: US461499A
Authority: US
Inventors: Richard W Schmutzler; Buren Edgar S Van; Gregory R Waldron
Original assignee: SCOTT MACHINE DEV CORP
Current assignee: Scott Machine Development Corp; SCOTT MACHINE DEV CORP
Priority date: 1974-04-17
Filing date: 1974-04-17
Publication date: 1975-09-30
Anticipated expiration: 1992-09-30

Abstract

An easel device for holding sheets of paper in a substantially vertical position for viewing by a typist or the like comprises a flat back plate and has means defining a downwardly-tapering trough with an open bottom situated adjacent the top of the back plate. The trough contains a plurality of rubber balls, so that gravity presses the balls lightly against the back plate. A sheet of paper may be easily inserted upwardly through the bottom and fed out the top of the trough, but a wedging action of the rubber balls prevents the paper from falling or moving downwardly. A bar slidable from top to bottom of the plate holds the paper flat against the back plate and serves as an index or cursor for the typist.

Description

United States Patent 11 1 Schmutzler et al.

[4 1 Sept. 30, 1975 1 1 KEYBOARD OPERATOR SHEET HOLDING AND FEEDING DEVICE [73] Assignee: Scott Machine Development Corporation, Walton, NY.

[22] Filed: Apr. 17, I974 [21] Appl. No.: 461,499

[52] US. Cl. 40/351; 40/128; 40/352 [51] Int. Cl. 341.] 11/14 [58] Field of Search 40/124, 124.4, 106.1, 78,

Germany 40/128 France 1. 40/140 Primary Eraminer-Robert W. Michell Assistant E.\amt'ner.1ohn H. Wolff Attorney, Agent, or F1'rmRichard G. Stephens l 5 7 1 ABSTRACT An easel device for holding sheets of paper in a substantially vertical position for viewing by a typist or the like comprises a flat back plate and has means defining a downwardly-tapering trough with an open bottom situated adjacent the top of the back plate. The trough contains a plurality of rubber balls, so that gravity presses the balls lightly against the back plate. A sheet of paper may be easily inserted upwardly through the bottom and fed out the top of the trough, but a wedging action of the rubber balls prevents the paper from falling or moving downwardly. A bar slidable from top to bottom of the plate holds the paper flat against the back plate and serves as an index or cursor for the typist.

19 Claims, 16 Drawing Figures US. Patent Sept. 30,1975 Sheet 1 of4 3,908,297

Ill-IIII F/G. lb

F/G/a US. Patent Sept. 30,1975 Sheet 3 of4 3,908,297

KEYBOARD OPERATOR SHEET HOLDING AND FEEDING DEVICE A variety of business and like operations require that a typist, key punch operator, or computer operator manipulate a keyboard while viewing a sheet of paper containing information to be typed, punched or otherwise entered. While many typists can readily operate keyboards situated in front of them with their heads turned to view a paper lying flat in a horizontal plane on desks or tables at their sides, it is frequently deemed undesirable to provide a desk or table solely for such a purpose. Some data-processing operations require that an operator type data from a long succession of edgeconnected sheets emitted as a single strip from an electronic printer, with the operator advancing to successive sheets as they are fed from the printer, and in such operations it is difficult to train the advancing strip of sheets so that one lies flat on a desk or table in convenient view of the keyboard operator. Operator speed, convenience, and error-free performance can be enhanced in most key-entry applications if the sheet of paper which must be viewed by the operator is positioned more nearly in front of the operator, and if the sheet can be positioned in a substantially vertical plane, where it can be more conveniently viewed by the operator. One object of the present invention is to provide an improved sheet-holding device which can hold sheets of paper in a substantially vertical position within convenient view of an operator. In many applications the operator must be positioned far from any wall, and even when the operator can be positioned near a wall it is frequently inconvenient to locate machinery so that the operator can face and view the wall, and hence a related object of the invention is to provide a sheet-holding mechanism which need not be mounted on a wall, and in which the plane in which the sheet is held can be rotated and/or translated to desired angular and translation positions. Another object of the invention is to provide an improved sheet-holding device for holding sheets in a substantially vertical plane which will allow sheets which are edge-connected to form a lengthy strip to be readily fed into and out of the position where they are viewed by the operator.

Some paper-processing machines use paper stored in the form of a roll, and in many machines paper is fed around one or more rollers as it is processed. Such storage and/or feeding of paper tends to impart a set to the paper, giving it a tendency to curl. If a sheet of paper is laid horizontally, its own weight helps lessen curling, although it is still frequently necessary that a typist place some type of weight device (frequently a ruler) atop the paper, so that the area of current interest on the paper lies flat and completely visible to the typist. If a sheet of paper is located in a substantially vertical plane, however, not only is the tendency to curl increased, but the use of simple weights such as rulers is precluded. Another object of the invention is to provide an improved paper sheet holding device which will hold a sheet flat, i.e. uncurled, in a substantially vertical plane, even if the sheet has a substantial tendency to otherwise curl.

it is apparent that a sheet of paper could readily be held in a substantially vertical plane against a suitable back surface by a variety of simple means, suchas by pinning the sheet to the surface with a plurality of thumb tacks, or adhering the sheet with masking tape. Such simple techiques are deemed wholly impractical,

however, in the many applications wherein successive sheets must be rapidly positioned in view and removed. A requirement that an operator maintain a supply of tacks or masking tape, or any similar accessories is also deemed disadvantageous. A very important object of the present invention is to provide an improved paperholding device for holding a sheet in a substantially vertical plane, which allows the sheet to be rapidly fixed in place, in a flat configuration, without the use of accessory fastening means such as tacks or masking tape or the like.

It is also apparent that a sheet of paper could be held in a substantially vertical plane by the use of a suitablypositioned back surface plate having two or more spring clips of the type used on ordinary portable clipboards, for example. However, the use of such spring clips tends to be undesirably clumsy. Substantial spring forces are required, particularly if papers of different thicknesses are used, and repeated flexing of such spring clips would tend to cause operator fatigue. To fix a sheet in position using an ordinary spring clip, the operator must use both hands, using one hand to depress and ultimately release the spring clip, while using her other hand to align an edge of the paper under the raised edge of the spring clip. Subsequent removal of the sheet also requires the use of both hands. One important object of the present invention is to provide an improved paperholding device in which the operator may insert and securely fix a sheet in position, in a substantially vertical plane, using only one hand, and then remove the sheet, again using only one hand. The advantage of being able to use only one hand for insertion and removal gains added importance when one considers that it greatly relaxes the requirements concerning which direction the operator must face. A further object of the invention is to provide an important paperholding device in which neither insertion or removal of a sheet requires the operator to overcome a spring force.

In various applications, including the common dataprocessing operations wherein successive sheets processed by a computer printer have their adjacent edges attached to form a long strip of sheets, considerable operator convenience and operating speed may be attained if the operator can readily insert or advance a newsheet into position by a simple pushing with one hand, without any need to release any spring clips or similar clamps, and a further important object of the invention is to provide a paper-holding device which readily lends itself to such operation.

For maximum utility it is desirable that a sheetholding device be readily adjustable to position sheets at different heights, different viewing angles and different viewing distances relative to the operator, and as is shown below, the assembly of the present invention readily lends itself to use of a convenient positioning linkage means readily adjustable in the aforementioned respects. Once adjusted, the sheet-holding device is held in position by friction in the linkage means. In order that the linkage means be readily adjustable it is desirable that modest friction be used. However, in order to prevent unwarranted mis-adjustment of the device once it has been adjusted to a desired position, it is necessary that operator use of the device in placing and re-placing successive sheets not require the operator to apply substantial forces to the sheet-holding device. Thus another object of the invention is to provide sheet-holding means to which the operator need not apply substantial forces in placing and re-placing successive sheets.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts, which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a front view of one form of paper-holding device constructed in accordance with the present invention.

FIG. 1a is a section view taken at lines 1a-1a in FIG.

FIG. lb is a view taken at lines 1blb in FIG. 1. FIG. 2 is a side elevation view of the device of FIG.

FIG. 3 is a top view of the device of FIGS. 1 and 2. FIG. 3a is an isometric view of a modified portion of the device of FIGS. 1-3.

FIGS. 4a and 4b are diagrams useful in understanding the function of several forms of the present invention.

FIGS. 5, 6, 7a, 7b and 8 are diagrammatic side views illustrating various modifications which may be made to the device of FIGS. 1-3, FIG. 7b being a view taken at lines 7b-7b in FIG. 7a.

FIGS. 9a, 9b and 9c are diagrams useful in understanding the operation of the present invention.

Referring now to FIGS. 1-3, the assembly thereshown will be seen to include a back-plate means 10 affixed to an adjustable linkage 11 (FIG. 2) by a universal joint connection means 12. Linkage 11 is shown as including a base bracket 14 having a cylindrical lower portion 14a adapted to seat within a generally-vertical cylindrical recess or socket 15 (FIG. 1) provided in a desk, table, or suitable similar portion of a dataprocessing or like machine. Knob 16 carrying set screw means 17 allows the cylindrical portion 14a of the linkage to be locked at a desired angle about the vertical axis of socket 15. In various applications it will be apparent that no set screw need be provided, and in any case it will be seen that bracket 14 may be rotated about a vertical axis so that linkage 11 and plate 10 are situated in any desired direction from recess 15. The precise manner in which base bracket 14 is affixed to a desk, table or machine is not crucial to the present invention. In some applications base bracket 14 may seat in a recess in any form of weighted base (not shown) which in turn merely resets atop a horizontal surface of a desk, table or a machine. In one convenient arrangement, recess 15 may be provided in a standard C-clamp (not shown), which clamp may be used to grip a table or desk top, for example.

A pair of rigid bars 18, (FIG. 2) extend from base bracket 14 to intermediate bracket means 21 formed by a pair of spaced plates, the ends of

bars

18 and 20 being pivotally connected to bracket 14 and bracket means 21 by

bolts

22, 22 passing through holes in the ends of

bars

18, 20. A further pair of rigid bars 24, extend from intermediate bracket means 21 to a further bracket means 26, which is also formed by a pair of spaced plates with the ends of

bars

24 and 25 pivotally connected to

brackets

21 and 26 by

bolts

27, 27.

Bolts

22, 22 and 27, 27 are tightened so that the plates of

brackets

14, 21 and 26 engage the bars with substantial friction, allowing the bars to rotate relative to the plates only when the friction is overcome. First spring means shown as comprising tension springs 29, 30 are connected between

pins

31, 31 on base bracket 14 and pins 32, 32 on bar 20. A second pair of tension spring means 34, 35 (only one 34 of which is visible in FIG. 2) are connected between pins on intermediate bracket 21 and pins 37, 37 on opposite sides of bar 24. As the section of linkage 11 formed by

bars

18, 20 rotates clockwise in FIG. 2, thereby increasing the moment arm through which the weight of the back-plate means acts at bracket 14, springs 29, 30 receive increased tension. Similarly, as the section of linkage 11 formed by

bars

24, 25 rotates, springs 34, 35 receive increased tension. Thus the tensions in the springs vary in accordance with the varying moment imposed by the weight of plate 10 as plate 10 is moved to different positions to place it at a convenient viewing position. Since the springs flex to oppose the moment imposed by the weight of plate 10, modest friction may be used at the ends of the bars, thereby making the linkage easy to adjust. Thus with base bracket 14 installed at a fixed position, it will be apparent that back-plate 10 may be moved leftwardly or rightwardly and upwardly or downwardly in FIG. 2 in order to locate plate 10 at a desired elevation and a desired distance from an operator position.

A block 39 (FIG. 2) bolted between the plates of bracket 26 by means of bolt 40 carries an integral curved rod 41 having a spherical metal ball 42 on one end. Bracket 44 welded to the rear side of back-plate 10 and clamp bracket 45 are each provided with circular holes in which ball 42 is seated to provide a universal joint or swivel connection. As best seen in FIG. 10, ball 42 is clamped between

brackets

44 and 45 by means of screw 47 and nut 47a, and screw 48 which engages a threaded recess in knob 48a. Screw 48 is fastened securely to bracket 44 by nut 48b, so that screw 48 cannot rotate as knob 48a is turned. Thus by tightening or loosening knob 48a, the frictional forces clamping ball 42 may be adjusted. Thus it will be seen that the universal joint connection and the linkage allow the backplate 10 to be positioned and angularly oriented so that the front surface of plate 10 lies at a desired position conveniently visible to the operator. In general the back plate will be arranged to extend substantially vertically, though slight deviations from a strictly vertical plane are desirably allowed.

Back-plate 10 is shown formed from a single metal sheet, with a pair of rearwardly-extending

side flanges

10a, 10b, a rearwardly-extending top flange 10c, and forwardly-extending lower flange 10d having a lip 10e. Each of the flanges serves to stiffen plate 10, and lower flange 10d also serves as a convenient tray, which may support pencils, marking pens, or the like (not shown), and which also may support the lower edge of a book or tablet should the operator desire to view such an item. It will be seen that when a book is supported on lower flange 10d, lip 10e will limit outward movement of the edges of book pages, thereby holding the book open to a desired page.

Rod 51 (FIG. 1) extends along one side of back-plate 10, and the ends of rod 51 are welded or brazed to plate 10 adjacent its upper and lower edges. A U-shaped slide bracket 53 carries a slot having a width slightly exceeding the diameter of rod 51, the slot extending along bracket 53 from point 52a to point 52b in FIG. lb. A wire spring 54 urges bracket 53 away from rod 51, thereby seating the bracket 53 with the ends of slot 52 engaging rod 51, whereby bracket 53 is rotatable about the substantially vertical axis of rod 51. An index means 55 preferably comprising a piece of a sheet of semi-transparent plastic has one of its ends affixed to slide bracket 53, by a screw and nut 57a, 57b and a screw 58a passing through a hole in bracket 53 into index knob 58. Thus it will be apparent that index 55 may be slid upwardly and downwardly relative to plate 10. Further, since index 55 is mounted at only one of its ends, it will be seen that it may be swung outwardly from back-plate l0, pivoting about rod 51, to a position where it extends perpendicularly to the plane of backplate 10, for example. In the use of the assembly, the paper sheet passes beneath index bar 55, which lies loosely atop the front surface of the plate. Bar 55 will be seen to hold a portion of the paper sheet flat against the front surface of plate 10. Bar 55 may carry graduations or other indicia, such as inch graduations or column numbers, preferably along its upper edge. When a book is supported by lower flange d with lip 10c limiting outward movement of the lower edge of the pages, it will be seen that index 55 will also prevent the pages from turning.

A particularly important feature of the invention resides in plate means 60 shown as comprising a metal sheet having a central portion 60a extending at an angle (shown as a in FIG. 2) relative to plate 10 and an edge 60b spaced outwardly from the surface of plate 10 at a distance indicated by dimension d in FIG. 2. The angle a was approximately 30 degrees in one successful embodiment of the invention. The ends 60c, 60d (FIG. 1) of plate 60 are bent rearwardly and affixed to the flanges of plate 10, as by means of welding, for example. A top portion 60a of plate 60 extends rearwardly part of the distance toward the plane of back-plate 10, providing a paper exit slot area 59. Thus plate portion 60, together with an upper portion of back-plate 10 will be seen to form a generally V-shaped trough having a lower opening adjacent edge 60b and an upper opening 59. Portion 606 also supports two pair of generally vertically-extending spacer posts or

fingers

61, 61 and 62, 62. Situated between each pair of spacer posts is a small rubber (or elastomeric) ball, two such balls being shown at 63 and 64. The balls preferably are comprised of soft rubber and provided with a buff (not slick) outer surfaces, and in practice balls of approximately one half inch in diameter have proven satisfactory for many applications. The balls each have a diameter at least slightly less than the lateral spacing between the pairs of finger posts, so that each ball can readily move upwardly between its associated pair of spacer posts, and the diameter of each ball exceeds dimension d, so that neither ball can fall below edge 60b of plate 60. The rearwardly-extending upper flange portion 60e of plate 60 also will be seen to limit upward movement of

balls

63, 64, slot 59 being less in width than the diameter of the balls,

In FIG. 2 a sheet of paper P is shown in phantom lying largely against backplate 10, with its lower end hanging below the tray portion, a mid-portion of the paper being held against the back-plate by means of index means 55, a further portion of the paper extending under plate 60, with an upper end of the paper protruding from exit slot area 59. The angular canting of portion a of plate 60 relative to back-plate 10 will be seen normally to urge

balls

63, 64 toward plate 10 with a force dependent upon the weight of each ball and dependent upon the angle a. Since the balls are very light, paper P may easily be moved upwardly into the trough formed by

plates

10 and 60, with each ball moving very slightly upwardly. However, if the paper tends to move downwardly, it will be seen that each ball will tend to wedge between

plates

10 and 60, clamping the paper to the back plate with greatly increased pressure. Thus paper may be fed upwardly through the device very easily, but any tendency of the paper to fall downwardly by reason of its weight, or to be pulled downwardly as the operator moves the index downwardly, will be prevented by the wedging action of the balls. The fact that paper may be fed upwardly through the device with no appreciable pressure allows the assembly to be used conveniently on the end of a linkage of the type shown, since feeding successive sheets upwardly does not tend to flex the linkage and move the back plate so that the operator must repeatedly reposition it.

Ifa ball of weight W rests in a trough formed by a vertical wall 10 and a surface inclined at a slope angle [3 as shown in FIG; 9a, the ball exerts a horizontal force F against wall 10 where F W tan B, and exerts a resultant force F against surface 60, where the resultant force F has a vertical component F, equal to weight W and a horizontal component of F =W tan ,8. If the ball radius is designated r, the horizontal distance x of the ball contact point on surface 60 from wall 10 may be shown to be:

that force P must slightly exceed W sin B in order to begin to roll the ball up the inclined surface 60. From equation (4) it will be apparent that ease of upward insertion of paper is facilitated by minimizing slope angle [3.

Now assume a sheet of paper P is interposed between vertical wall 10 and the ball, as shown in FIG. 9b. Downward vertical movement of the paper will be resisted by a friction force F resisting movement of the paper relative to wall 10, and by a friction force F,, resisting movement of the paper relative to the ball. The magnitudes of friction forces F and F will be commensurate with F the paper to metal coefficient of friction between wall 10 and the paper, and F,,, the paper to rubber coefficient of friction between the paper and the ball, respectively, and both forces F and F,, will vary as a direct function of horizontal force F Since horizontal force F,,, equals W tan [3, it will be seen that decreasing the slope angle ,8 tends to decrease friction forces F and F,,. Thus it would first appear that decrease of slope angle B so as to ease upward insertion of the paper would decrease the friction forces, perhaps rendering them too small to prevent downward movement of the paper. It also would appear, if one assumes the weight W of the ball to be very small, only a fraction of an ounce, so as to ease paper insertion, that the horizontal force F must be even less, so that the frictional forces F and F would be far too small to resist downward movement of the paper. However, in accordance with the present invention, a wedging action of the ball occurs if the paper tends to move downwardly, with the friction forces F and F,, increasing to values appreciably greater than the weight of the ball, and in a case where substantial downward tension is applied to the paper, to values even hundreds of times greater than the weight of the ball. As illustrated in FIG. 9c, in grossly exaggerated fashion, if paper P, which is shown with an exaggerated thickness, is pulled downwardly with a tension T, the wedging action tends to deform the ball. The compression of the lower portion of the ball acts generally as shown by the arrow, pressing the ball tightly against the paper and wall 60. Furthermore, the compression of the ball, and the depression of the portion of paper engaged by the ball cause an increased contact area between the ball and the paper, and between the ball and plate 60. Acting cumulatively, these effects readily prevent downward paper movement, even when extremely light balls are utilized. Nevertheless, upon release of downward tension and application of an extremely small upward force on the paper, in friction forces holding the paper immediately fall to negligible values, allowing the paper to be readily raised.

While plate portion 60a is shown as comprising a trough which extends entirely across the back plate 10, it will become apparent that only small portions of 60a laterally adjacent the balls are required in order to hold the balls in place, and that the remaining portions of 60a merely support those small portions in place. Thus in some forms of the invention various portions of plate means 60 may be cut away, as in the modified plate means 60' shown in FIG. 3a.

In some applications the edge 60a of plate 60 may be formed and spaced relative to back plate as shown in the diagram of FIG. 4a. With no paper in place, the weight of the ball provides a given wedging action, and a given amount of friction. Insertion of the upper edge of a sheet of paper past ball 63, in the direction shown by the arrow in FIG. 4a, then requires that the paper be stiff enough that it may apply a force to the ball sufficient to overcome that amount of wedging action, and, in essence, roll the ball 63 very slightly up the inclined surface of plate portion 60a. As previously indicated in connection with FIGS. 9a-9c, the steeper the inclination of surface 60a, the stiffer the paper must be in order that it be capable of sufficiently displacing the ball. In order that very thin and flexible paper be readily insertable, it is desirable that each ball become unwedged and lift very easily as the upper edge of a paper sheet is urged upwardly against it. To this end, some forms of the invention may use a form of plate 60 of the nature generally shown in FIG. 4b, wherein lower edge 60a is shown bent or curved. With a bend of the nature shown in FIG. 4b, so that the ball rests on almost horizontal surface, it will be apparent that the ball may be rolled slightly away from plate 10 much more easily than in FIG. 4a, so that thin, flexible paper is capable of applying sufficient force to roll back the balls and allow upward movement of the paper through the trough. In general, the lower edge of surface 60a will not be arranged to be horizontal, i.e. normal to the surface of back-plate 10, but always provided with sufficient slope that the balls will lie against the back plate even when the back-plate is tilted slightly top-forwardly toward the operator. It will be apparent atthis point that the operator may control the required paper insertion force to some degree by slightly tilting the entire back plate and trough assembly about a horizontal axis.

As the angle between the back plate and plate 60 is increased so as to reduce the required paper insertion force, the maximum gripping force will be decreased. However, the maximum gripping force, even with large values of angle a, is so great that sheets are quite adequately held. One may note that if an extreme downward pull is exerted on the paper, which might occur infrequently by accident, the friction in linkage 11 may be arranged to allow the back plate assembly to move downwardly so that the paper will not be torn.

As thus far described, it will be seen that paper must be advanced upwardly through the apparatus of the invention, that downward pulling of the paper serves to clamp the paper very tightly, so that large downward pulling forces would result in tearing of the paper. It is desirable in some applications of the invention that downward travel of the paper be made possible, when it is desired, so as to allow an operator to return an edge-connected sheet she has previously used, for error-correction purposes, for example. One form of modification of the device is diagrammatically shown in FIG. 5. A device modified as per FIG. 5 functions in same manner as the previously-described embodiment when its plate 60 is in its solid-line position. Plate 60 is shown pivotally attached to the back plate 10, however, in FIG. 5, and when pivoted about axis to the position shown in dashed lines, the ball 63 is moved away from back plate 10, and held cradled between portions 60:: and 60a of plate means 60, allowing the paper to be pulled freely downwardly through the device. The side edges of plate 60 in FIG. 5 include small axle pins on axis 70 which seat in a pair of brackets 70a extending forwardly at opposite sides of back-plate 10.

In alternative modifications diagrammatically illustrated in FIG. 6, plate 60 is similarly pivotable about axis 70. A pair of

arms

71, 71 pivotally attached to the ends of plate 60 adjacent the sides of back-plate 10 each carry a plurality of holes. A pair of pins 72 extend laterally from the side flanges of back-plate 10. Thus plate 60 may be swung to different angular positions and held at any of them by selecting which holes of

arms

71, 71 engage the pins. Arranging the plate 60 at different angles allows one to vary the ballwedging pressure to suit different applications.

While the device of FIGS. 13 utilizes only a pair of rubber balls, it should be noted that three or more balls may be used in various applications where the use of heavy paper requires more holding force, or in applications where narrow pieces of paper are used, so as to insure that at least two balls will grip the paper,.thereby to prevent it from cocking or tilting.

In the alternative device diagrammatically shown in FIGS. 7a and 7b, rather than using a plurality of rubber balls, a pair of rubber or other

elastic discs

73, 73 are shown carried on a thin wire axle 74. This assembly can be made lighter than a pair of spherical balls, and thus provide easier paper entry. Discs 73 of numerous different axial widths may be used of course, in different applications, and if a disc 73 has substantial axial width, it could, of course be referred to as a cylinder.

While the embodiments thus far described are shown using ball or disc means which urge the paper rearwardly against the back plate, in a direction away from the operator, an arrangement of the nature shown in FIG. 8 may instead be used, wherein ball 63 presses the paper forwardly against front plate 60. Back-plate 10 is shown provided with a hinged flap 10, the angle of which can be adjusted by knob 76 and set-screw 77, thereby to adjust the required paper entry force and the gripping force which prevents downwardly paper movement.

While the invention has been described in connection with its usage by a keyboard operator, it will be apparent at this point that the invention also may be used in numerous non-keyboard applications, to hold drawings, for example, to be viewed, or to hold sheets to be viewed during rnanual'type-setting operations and the like.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Apparatus for supporting a portion of a strip of paper fiat in a substantially vertical first plane at a viewing position and allowing successive portions of said strip to be fed to said viewing position, comprising, in combination: first means for providing a first surface; adjustable linkage means including a plurality of endconnected frictionally-retained linkage members for supporting said first means to dispose said first surface in said first plane; a second member supported on said first means, said second member having a second surface spaced from and sloping downwardly toward said first surface to provide a trough having lower and upper openings; and revolvable and vertically translatable retaining means lying within said trough, whereby in the absence of a portion of said paper strip between said first means and said second member said retaining means rests against said first and second surfaces and said first and second surfaces retain said retaining means within said trough, said retaining means moving toward said lower opening and resting against said first and second surfaces insertion of paper strip upwardly into said trough through said lower opening will upwardly displace said retaining means to allow said strip to be moved upwardly through said trough and out said upper opening, and said retaining means will wedge said strip against said first surface, preventing downward movement of said strip through said trough.

2. Apparatus according to claim 1 wherein said retaining means comprises a plurality of spherical elastic balls.

3. Apparatus according to claim 2 having means for limiting lateral iiiovement of said spherical balls.

4. Apparatus according to claim 1 wherein said retaining means comprises a plurality of elastic discs.

5. Apparatus according to claim 4 having means interconnecting said discs to establish the lateral distances of said discs from each other.

'6. Apparatus according to claim 1 having index means vertically slidable along said first surface.

7. Apparatus according to claim 6 having shaft means extending vertically along one side of said first means, said index means comprising a bar having one end mounted for limited pivotal rotation about said shaft means.

8. Apparatus according to claim 1 wherein said second member has a lower edge extending parallel to and spaced a first distance from said first surface, and said retaining means has a diameter greater than said first distance.

9. Apparatus according to claim 1 wherein said second member is adjustably supported relative to said first means to slope downwardly toward said first surface at any one of a plurality of selected angles.

, 10. Apparatus according to claim 1 wherein said second surface comprises a curved surface portion sloping downwardly toward said first surface with a decreasing slope.

11. Apparatus according to claim 1 wherein said second surface comprises upper and lower surface portions connected at a bend in said second member, said lower surface portion having a lesser slope than said upper surface portion.

12. Apparatus according to claim 1 wherein said adjustable linkage means includes a universal joint connecting said first means to one of said end-connected frictionally-retained linkage members.

13. Apparatus according to claim 1 wherein at least one of said frictionally-retained linkage members comprises first and second brackets, first and second rods each extending between and frictionally pivotally connected to each of said brackets, and spring means connected between one of said rods and one of said brackets.

14. Apparatus according to claim 1 having a base support bracket, said adjustable linkage means being interconnected between said base support bracket and said first means and flexingly adjustable to support said first means at varying distances from said base support bracket, said linkage means including spring means operable upon flexing of said linkage means to oppose moments applied to said linkage means by moving said first means varying distances from said base support bracket.

15. Apparatus according to claim 1 wherein said adjustable linkage means comprises a base support bracket pivotable about a substantially vertical axis and a universal joint connected to said first means, said end-connected frictionally-retained linkage members comprising a foldable linkage connected between said base support bracket and said universal joint.

16. Apparatus for supporting a portion of a strip of paper sheet flat in a substantially vertical first plane at a viewing position for viewing by an operator and allowing successive portions of said strip to be readily fed to and past said viewing position by direct manual manipulation of said strip, comprising, in combination: a first member having a first surface; means for supporting said first member to dispose said first surface in said first plane at said viewing position; a second member supported on said first member, said second member having a second surface spaced from and sloping downwardly toward said first surface to provide a trough having lower and upper openings; and revolvable and vertically-translatable wedging means lying within said trough, whereby in the absence of a portion of said strip between said first and second members gravity will cause said wedging means to revolve and lower within said trough to rest against said surfaces, insertion of said strip upwardly into said trough through said lower opening will upwardly displace said wedging means against the force of gravity to allow said strip to be moved upwardly through said trough and out said upper opening, and said retaining means will wedge said strip against said first surface, preventing downward movement of said strip through said trough.

17. Apparatus according to claim 16 wherein said wedging means comprises a plurality of spherical balls.

18. Apparatus according to claim 16 wherein said wedging means comprises a plurality of elastic discs.

19. Apparatus according to claim 16 having means for limiting lateral movement of said wedging means within said trough.

Claims

1. Apparatus for supporting a portion of a strip of paper flat in a substantially vertical first plane at a viewing position and allowing successive portions of said strip to be fed to said viewing position, comprising, in combination: first means for providing a first surface; adjustable linkage means including a plurality of end-connected frictionally-retained linkage members for supporting said first means to dispose said first surface in said first plane; a second member supported on said first means, said second member having a second surface spaced from and sloping downwardly toward said first surface to provide a trough having lower and upper openings; and revolvable and vertically translatable retaining means lying within said trough, whereby in the absence of a portion of said paper strip between said first means and said second member said retaining means rests against said first and second surfaces and said first and second surfaces retain said retaining means within said trough, said retaining means moving toward said lower opening and resting against said first and second surfaces insertion of paper strip upwardly into said trough through said lower opening will upwardly displace said retaining means to allow said strip to be moved upwardly through said trough and out said upper opening, and said retaining means will wedge said strip against said first surface, preventing downward movement of said strip through said trough.

3. Apparatus according to claim 2 having means for limiting lateral movement of said spherical balls.

6. Apparatus according to claim 1 having index means vertically slidable along said first surface.

10. Apparatus according to claim 1 wherein said second surface comprises a curved surface portion sloping downwardly toward said first surface with a decreasing slope.