Card holder

Abstract

The print opening of a card holder is configured to have unidirectionally angled upper and outer edges that progressively cam the edges of a sheet into engagement with a platen without catching the corner of the sheet or otherwise jamming the paper feed operation.

Description

BACKGROUND OF THE INVENTION

Printers such as typewriters typically include a device positioned adjacent the printing point termed a "card holder" whose function it is to hold a writing sheet against a support platen. This function is particularly important where relatively stiff card stock is being typed upon which otherwise would not follow the contour of the platen.

A card holder made of clear plastic material has been found to be particularly convenient since it does not interfere with the operator's view of typed material. Furthermore, useful scales can be directly imprinted upon the clear plastic material in a particularly convenient manner. To achieve maximum rigidity, the plastic card holder may be made to completely surround the printing point thereby providing an opening through which print impact occurs. A plastic card holder of this configuration serves its function well but requires the printing point to be positioned over a central portion of a writing sheet being inserted into the typewriter. Where the printing point is positioned adjacent to the left margin of the sheet being inserted, the print opening in the card holder has a serious tendency to trap the corner of the sheet. Where lightweight sheet material is being inserted, this trapping may cause the corner to fold and the sheet to be spoiled. Heavier card stock, when trapped, may actually jam the feed operation. Alternatively, where easily replaceable "snap-in" card holders are employed, trapping of heavy card stock may cause ejection of the card holder from its support.

DISCLOSURE OF THE INVENTION

I have discovered that the problem of corner folding or jamming can be solved by a simple modification to the upper and leftward edges of the print opening in a card holder. The upper edge is unidirectionally angled to receive the leading or top edge of the sheet being inserted into the typewriter at only a single point. This point moves progressively toward the corner of the sheet as the sheet is fed upwardly during insertion. This progressive engagement assures that the sheet corner will be reliably fed past the card holder print opening. The angle of the opening upper edge should be sufficiently large to assure progressive engagement of a sheet leading edge that has not been precisely aligned with the platen prior to insertion in the typewriter. I have found, for example, that an angle of about 5.degree. to the horizontal is satisfactory. To assist the progressive camming action, I prefer to transfer the cross-sectional profile of the print opening edge to face inwardly toward the typewriter platen.

The leftward or outer edge of the print opening is likewise inclined outwardly so as to engage but a single point on the left edge of a sheet. This engagement point moves progressively toward the corner of the sheet as the printing point moves rightwardly to prevent jamming.

These and other objects, features, and advantages of my invention will be apparent to those skilled in the art from the following more specific description of an illustrative preferred embodiment thereof, wherein reference is made to the accompanying drawing of which:

FIG. 1 is a fragmentary perspective view of a portion of a typewriter having a card holder constructed in accordance with the prior art.

FIG. 2 is a fragmentary perspective view of a portion of a typewriter similar to that shown in FIG. 1 but employing an improved card holder constructed in accordance with my invention.

FIG. 3 is a front elevational view of the card holder and typewriter platen shown in FIG. 2, and

FIG. 4 is a side cross-sectional view of the card holder and platen shown in FIG. 3 taken along line IV--IV thereof.

Referring now more specifically to the drawing, in FIG. 1 a typewriter or printer 10 is shown having a print forming type element 11 supported by a carrier 12 adjacent an elongated circular cylindrical paper sheet support platen 13. Type element 11 and platen 13 defines a printing point 14 therebetween. Carrier 12 is in turn supported on a laterally extending shaft 15 for movement horizontally with respect to the platen 13 thereby displacing the printing point 14 along a writing line 16.

A paper deflector plate 30 is carried beneath platen 13 and includes idler pressure rolls 31 for gripping a sheet of paper or other writing material 20 against the platen 13. The platen 13 is rotatably mounted by bearings 32 in frame side plates 33. Knobs 34 at either end of the platen 13 enables it to be rotated to move sheet 20 in a paper feed direction 35 during paper insertion.

A prior art type card holder 40 is supported adjacent the printing point 14 by a support bracket 17 that in turn is carried by a mounting plate 18 on the carrier 12. Card holder 40 includes an inverted U-shaped print opening 41 through which print element 11 impacts sheet 20. The card holder 40 is curved or otherwise configured to wrap the sheet 20 about platen 13 and into close adjacency therewith particularly at the printing point 14. A paper bail 36 carrying rollers 37 thereon further assists in holding the sheet material 20 around the platen 13.

The prior art card holder 40 will satisfactorily receive a sheet 20 that is rolled to its printing position with print point 14 positioned over a mid portion of the sheet 20. However, a failure can occur as shown in FIG. 1 where the corner 21 of sheet 20 is aligned with part of the print opening 41 during initial roll in. In this circumstance, the corner 21 of the sheet 20 being unrestrained, projects through the print opening 41 and ultimately becomes trapped as shown in FIG. 1. If the sheet 20 is of lightweight material, corner 21 will fold over forming a "dog ear" and the sheet 20 may be spoiled. On the other hand, if the sheet 20 is of heavy stock, the feed will simply jam requiring the operator to roll back the platen 13, move the print point 14 to the right, and reroll the platen 13 to the starting position. A similar entrapment of the corner 21 can occur if typing is to be done very close to the upper left-hand edge 22 of the sheet 20. In this event, the unrestrained corner 21 becomes trapped as shown in FIG. 1 as the carrier 12 moves rightwardly with letter feeding movement.

As shown in FIG. 2 and particularly in FIG. 3, a card holder 50 constructed in accordance with my invention has a print opening 51 partially defined by camming edges 52 and 53 that are configured to engage the edges 22 and 23 of sheet 20 progressively and thereby move the sheet 20 into close adjacency with the platen 13 without trapping the sheet corner 21 as in the case of the prior art card holder 40 described in FIG. 1. More specifically, the card holder 50 shown in FIGS. 2 and 3 constructed of a transparent plastic plate-like body comprising a pair of side portions 54 and 55 which extend upwardly in the paper feed direction 35 and define respectively side edges 53 and 56 of the print opening 51. These side edges 53 and 56 are separated by a spacing 57 that spans the print point 14. An upper bridging portion 58 of the card holder 50 interconnects the side portions 54 and 55 and defines the upper edge 52 of the print opening 51. Unlike the print opening 41 in the card holder 40 shown in FIG. 1, upper edge 52 of the card holder 50 is unidirectionally angled upwardly and to the left throughout the entire spacing 57. The longer side edge 53 is angled slightly upwardly and laterally outwardly with respect to the printing point 14.

The angle formed by edge 52 functions to limit engagement of the edges 23,52 to a single point for example, point 24 on the sheet leading edge 23 as the sheet 20 is moved in the paper feed direction 35. The angle of edge 53 functions similarily upon letter feed movement of print point 14 rightwardly along writing line 16. The point of sheet edge engagement between the edge 52 or 53 of the card holder opening 51 moves toward the corner 21 of the sheet 20 and progressively displaces the corner 21 inwardly toward the platen 13 where it cannot be trapped as shown in FIG. 1.

To assist in this progressive movement, the cross-section of the upper camming edge 52 is tapered to provide a camming surface 59 best shown in FIG. 4 thereby avoiding an abrupt ledge that might otherwise serve as a trapping surface for the corner 21 of the sheet 20. Although not shown, left edge 53 is similarly tapered.

With a card holder 50 configured in accordance with my invention, the operator need not be concerned with the relative location of the left corner of a page with respect to the typewriter printing point. Should the sheet corner portion 21 appear within the print opening 51 during feed-in movement of the sheet 20 along paper feed direction 35, the sheet leading edge 23 will be progressively engaged by the edge portion 52 until the corner 21 is guided beneath the upper bridging portion 58. Similarly, if it is desired to type very near the upper left corner 21 of a sheet 20 such that the left edge 22 of the sheet 20 lies within the print opening 51. Rightward movement of card holder 50 with letter feed of the carrier 12 first engages the lower portion of edge 53 with sheet left edge 22 and progressively moves the point of contact with edge 22 upwardly toward corner 21 thus camming corner 21 to its secure position under the card holder 50.

Those skilled in the art will recognize that various modifications, additions, and deletions to the preferred embodiment of a card holder thus described can be made without departing from the principles of my invention. Particularly, it will be recognized that a card holder for a typewriter normally used to type from right to left should be designed with oppositely directed print opening edges. I thus intend the subject matter patented to be limited solely by the appended claims.

Claims

I claim:

1. A printer including print forming mechanism, and a writing sheet support platen, said print forming mechanism and said platen defining a printing point and writing line therebetween, means for feeding a writing sheet into operative interposition between said print forming mechanism and said platen in a paper feed direction that is normal to said writing line, and means for holding the writing sheet against said platen at said printing point comprising: a plate-like body, means supporting said plate-like body adjacent said platen at said printing point, said plate-like body comprising a pair of side portions that extend in said paper feed direction and are spaced laterally on opposite sides of said printing point, and an upper bridging portion positioned above said printing point and interconnecting said side portions, said side and upper bridging portions thereby respectively defining side and upper edges of an open portion through which said print forming mechanism is enabled to have print cooperation with the writing sheet supported by said platen, said plate-like body being configured to urge the writing sheet into close adjacency with said platen at said printing point; wherein the improvement comprises:

said upper bridging portion of said plate-like body defining an upper camming edge of said open portion that extends transverse to said paper feed direction at a unidirectional angle other than substantially 90.degree. throughout the entire space between said side portions.

2. A printer as defined in claim 1 wherein said upper camming edge is configured in cross-section normal to said writing line to provide a camming surface facing said platen.

3. A printer as defined in claim 1 wherein said upper camming edge of said open portion faces leftwardly of said writing line.

4. A printer as defined in claim 1 wherein said printing sheet support platen comprises an elongated circular cylindrical member that is rotatably mounted to provide said writing sheet feeding means.

5. A printer as defined in claim 1, one of said side edges being longer than the other of said side edges and wherein the improvement further comprises: the longer of said side edges extending transverse to the direction of said writing line at an upwardly laterally outward angle with respect to said printing point.