US2755773A - Erasing shield for use with the typewriter - Google Patents

Description

July 24, 1956 E. R. HAYNIE ERASING SHIELD FOR USE WITH THE TYPEWRITER Filed June 12, 1955 ATTORNEYS ilnited rates Patent Q ERASING SHIELD FOR USE WITH THE TYPEWRITER Edna R. Haynie, Whittier, Calif.

Application June 12, 1953, Serial No. 361,319

1 Claim. (Cl. 120-41) This invention relates to an erasing device for use with the typewriter and has for its object the provision of a pressure plate adapted to be inserted below the sheet on which erasing is to be done and an apertured shield to be placed above said sheet, said last shield being apertured to permit the insertion through said apertures of the usual typewriter rubber or other means for erasing.

An object of the invention is to provide a firm support for the paper on which the erasure takes place of such a nature that the pressure of the eraser on the paper is distributed over a large area below the pressure plate, so that in the event there are any copies and carbon paper below the pressure plate on the platen of the typewriter, these Will not be smeared by the erasing.

Another object is to provide a device of the character described in which the pressure plate and shield may be made integral and provided witha handle if desired.

Other objects and advantages will be apparent from the following specification and the accompanying drawings in which is disclosed by way of illustration a preferred embodiment of the invention. It will be understood however that this is merely illustrative and not limitative, the invention being as defined in the appended claim.

In the accompanying drawings:

Figure 1 is a plan view of the combined shield, pressure plate and handle;

Figure 2 is a sectional view on the line 2-2 of Figure 1;

Figure 3 is a side view of the device shown in Figure 1; and

Figure 4 is a sectional view of the device shown in the preceding figures in place on the platen of the typewriter.

Referring to a detail description of the preferred embodiment of the invention illustrated in the drawing, the construction shown comprises a shield plate and a pressure plate 11 lying below the shield plate, each of said plates being of elongated general rectangular configuration and being curved transversely to correspond generally to the curvature of the outer face of the platen 23 of the ordinary typewriter. Extending longitudinally from one end of the device is a handle part that is substantially U-shaped in cross section and formed integral with the shield plate and pressure plate, said handle part being of less width than the width of the plates 10 and 11, opposite side portions 12, 13 of the handle part joining said plates centrally of the sides thereof. As shown in Fig. 3 of the drawing, the opposite side portions 12, 13 of the handle part are evenly spaced from each other throughout the length thereof and form continuations respectively of the shield plate 10 and pressure plate 11, said plates being evenly spaced from each other throughout the length thereof similar to the spacing of the side portions 12, 13 of the handle part. This space 14 and the space between the side portions 12 and 13 of the handle part is large enough to receive the sheet 2,755,773 Patented July 24, 1956 ire of paper on which the erasure is to take place, this construction, it will be noted, providing for free insertion of a sheet of paper between said plates throughout the length of the same and between the side portions of said handle part beyond the end of said plates at which said handle part is located as well as beyond the other end of the plates. The shield 10 is provided with a number of apertures to which the erasing means such as the ordinary typewriter eraser 15 may be inserted, these apertures being shown at 16-20, inclusive, and obviously any number of the apertures may be employed and they may be of any desired shape.

As shown in Figs. 2 and 3 of the drawing, the shield plate along each side edge thereof from end to end has a reversely curved lateral extension substantially semicircular shape in cross section forming an upwardly facing trough, said reversely curved lateral extensions being designated 21 and 22. These trough extensions 21 and 22 project laterally beyond the side edges of the pressure plate 11.

The preferred form of the device as shown in the figures may preferably be made of one piece of brass, aluminum, or plastic, the latter being preferred as it is transparent and easily formed, the structure being sufiiciently rigid or stiff enough to normally maintain the form shown in Fig. 3 with the plates 10 and 11 and the opposite side portions 12 and 13 of the handle part evenly spaced from each other throughout the length of the same.

The arcuate underside of the pressure plate 11 is shaped to conform to the platen 23 of the ordinary typewriter. If this platen, as is commonly the case, is approximately one and one-half inches in diameter, then the inner arcuate surface opposed to the platen would span approximately ninety degrees and the length of the pressure plate 11 may be about five and three-quarter inches. This enables the device to be inserted from either side of the paper and, with the apertures as shown, practically all erasing conditions will be met.

Obviously the guard 10 and pressure plate 11 may be separate from each other, but in the preferred form these are united and are provided with the handle 12 as described.

For the sake of illustration it will be assumed that the device is being used with a typewriter in which there is an original sheet 24, a carbon sheet 25, and the copy sheet 26, which are wrapped around the platen 23 in the usual manner. In the event that it is desired to erase something on the original sheet 24, it is lifted out of the way to the right, Figure 4, and the pressure plate 11 is slipped below the sheet 24 with the guard 10 lying above said sheet. The members 10 and 11 are moved about until the proper aperture, say 19, is brought over the mat ter to be erased, whereupon the eraser 15 is applied to the matter to be erased. Now, it will be perceived from a study of Figure 4 that the pressure of the eraser on the paper is not transmitted directly to the underlying carbon and copy sheets 25 and 26, but is distributed throughout the area of the arcuate surface of the pressure plate 11 which, as before stated, may span ninety degrees of the platen roller and also extends cross-wise of the sheet five inches or more. The result is that the underlying copy sheet 26 is not smudged by the erasure which otherwise takes place unless some member such as 11 is provided to dissipate the pressure of the eraser over a considerable area. Now to erase on the copy sheet 26 it is only necessary to move the original sheet 24 and the carbon paper 25 to the right off the platen and then insert the pressure plate 11 below the copy sheet 26. If there are any other underlying copy sheets and their carbons they will not be smudged.

It will be noted that the concave inner surface of the 3 pressure plate 11 may be slightly more concave than the outer convex surface of the platen 23, so that right in the middle of the plate where it immediately underlies the eraser aperture 19, which is the central aperture through which most erasing is done, the pressure plate 11 does not actually contact the surface of the paper be low it. This distributes the force applied to the pressure plate outwardly towards the extremities thereof and serves to further distribute the pressure of the eraser. It will be noted that the pressure plate, in order to properly carry out applicants inventive concept, must be arcuate as shown. It a fiat plate is used instead it will be obvious that it will only make a line contact with the paper below it and consequently will cause smears where the pressure is solely on this line where it touches the platen cylinder as with a flat plate the pressure is not distributed.

It will be noted that because of the arcuate shape of the pressure plate there is no tendency for it to ride off the platen; that is to say, it can be easily held in position while erasing.

While the troughs 21, 22 have been briefly referred to, it will be seen that only one trough may be provided if desired. However, it is desirable to have a trough on each side of the shield to catch any particles of dust that may be formed when erasing.

When the erasing operation is completed, the trough is pulled out from the paper at one side without tipping. Then the dust can be easily emptied from the trough or troughs.

What is claimed is:

An erasing device consisting of a substantially rigid, one-piece structure comprising an apertured shield plate 01 elongated general rectangular configuration, a pressure plate of general rectangular shape underlying said shield plate, said pressure plate and shield plate being curved transversely to correspond generally to the curvature of the outer face of a conventional typewriter platen,

the shield plate along each side edge from end to end having a reversely curved lateral extension substantially semi-circular shaped in cross section and forming an up- Wardly facing trough, the troughs projecting laterally beyond the side edges of said pressure plate, and a handle part of less width than the width of the shield plate and the pressure plate and extending longitudinally from one end thereof, said handle part being substantially U-shaped in cross section, the opposite side portions of the handle part being evenly spaced from each other throughout the length thereof and forming continuations respectively of the shield plate and pressure plate, said handle part rigidly joining the said plates together with their opposing faces throughout the length of the same evenly spaced from each other similar to the spacing of the opposite side portions of the U-shaped handle part to provide for tree insertion of a sheet of paper between said plates throughout the length of the same and between the side portions of the handle part beyond the end of said plates at which said handle part is located as well as beyond the other end of said plates, the rigid pressure plate providing a firm support for the sheet of paper and pr0- viding for distribution of the erasing pressure over a relatively large area below the pressure plate, and said pressure plate being rigidly maintained in spaced relation with the shield plate.

References Cited in the file of this patent UNITED STATES PATENTS 680,227 Copland Aug. 13, 1901 717,275 Reed Dec. 30, 1902 1,182,468 Fortin May 9, 1916 1,969,603 Gibson Aug. 7, 1934 2,260,089 Pierce Oct. 21, 1941 FOREIGN PATENTS 546,062 Germany Aug. 24, 1933

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