US2330954A - Eraser - Google Patents

Description

Oct. 5, 1943. A. C'QTERA 2,330,954

ERAS ER Filed Nov 27, 1941 1: 1 m nae.

INVENTOR.

fluaasfus 5 0075/54 A T TORNE Y.

Patented Oct. 5, 1943 ERASER I AIag tstus'iS.v Cetera,Galvestom Tex assignor' to; N

Charles Brunin'g Company, Inc., New York;

N. Y., acorporation of New York I Application November 27, 1941'; SerialN'o. 420,633

scams; (Gino-+4.0.)

The present invention relates to erasers and,

more specifically, to the structureofthematerial' which like. a

The usual form 'oferaser utilized in erasing machines -isthe cylindrical -eraser'or eraser in which the erasing material is formed in the shape of a cylinder, the cylindrical surface of which is smooth. Although erasers have been used having cross-sections other than cylindrical,

is used in erasingmachines'and-the the surface of these erasers has always been smooth.

In accordance with the present invention, it is an object to provide an eraser having a structure such that the erasing operation will be accomplished more effectively and more quickly than has been accomplished with the structures heretofore available.

The foregoing object is attained by providing a structure wherein the surface of the eraser is formed with depressions in the form either of grooves or pits which thus disturb or break up the regularity and smoothness of the outer surface of the eraser. The essential feature of the present invention is the provision of the eraser surface with re-entrant portions, the design or configuration of which is unimportant, the important factor being that these configurations lie in the side surface of the eraser.

In order that the invention may be understood more fully, it will be described now with reference to the accompanying drawing, wherein:

Fig. 1 is a View in side elevation of an eraser formed in accordance with the present invention.

Fig. 2 is a View in end elevation showing the eraser of Fig. 1.

Fig. 3 is a view similar to Fig. 1, showing a modified form of eraser in which the cylindrical surface is formed with a plurality of pits or recesses.

Fig. 4 is a view in end elevation, showing the eraser of Fig. 3.

Fig. 5 is a view similar to Fig. 1, showing a further modified form of the invention in which the cylindrical surface of the eraser is formed with spiral grooves.

Fig. 6 is a view in end elevation, showing the eraser of Fig. 5.

Fig. '7 is a view similar to Fig. 1, showing a further modified form of the invention.

Fig. 8 is a view in end elevation, showing'the eraser of Fig. 7.

Referring to the above drawing and particularly to Figs. 1 and 2, aneraser I0'formed of rubber or the like is provided with a cylindrical surface 41 n which aplu'r'ality of longitudinally extending grooves or notches I 2are formed; In

accordance with the general practice," the eraser is made of rubber and. the groo'vesimay be of varying depth and width in order that the. erasing end of'the'eraser'may-be'formed with notches or irregularities such'as illustrated in Fig. 2. It has been found that the eraser formed in this fashion is far more effective in performing erasing operae tions than the identical eraser would be if it were formed with a cylindrical surface of uniform and smooth cylindrical nature.

A modified form of the invention is shown in Figs. 3 and 4, wherein the cylindrical surface H of the eraser I0 is formed with a plurality of pits I3. These pits are preferably formed in sufiioient number and location such that, at any one time,'the Working surface and edge of the eraser will always be formed with a plurality of irregularities resulting from the pits as illustrated in Fig. 4.

In the form of the invention shown in Figs. 5

and 6, the eraser H] is provided with a cylindrical surface H having'spiral grooves I4 formed therein in sufficient number'to'provide a plurality of notches at the edge of the working surface of the eraser.

In the modification of the invention shown in Figs. 7 and 8, the eraser is formed of hexagonal cross-section in order that a plurality of sharp corners 15 may be provided. 'I'heedges formed by these corners provide for an operation that is found to be far more effective than the conventional eraser of round cross-section.

It is to be understood that the eraser described hereinabove is in the form of an elongated member that is adapted to be mounted in a rotating chuck, the structure being such that th erasing end or surface rotates about the axis of the eraser as it is brought into erasing relationship with the surface to be erased. In accordanc with the.

present invention, the erasing properties of the device are greatly improved by providing surface irregularities or conformations on the sides of the eraser that interrupt or disturb the circular shape of the erasing surface or end of the eraser.

It will be readily apparent that the invention may be embodied in erasers by forming in the side surfaces thereof irregularities of many shapes and sizes other than those illustrated in the drawing as above referred to. quirement of the invention is that the side surface of the eraser be formed with a surface having irregularities such that re-entrant portions are available in the side surface to provide irregu- The essential relarities or recesses in the edge of the working surface at the end of the eraser.

While the invention has been described with reference to the specific eraser structure shown in the accompanying drawing, it is not to be limited save as defined in the appended claims.

I claim: 7 r

1. An eraser for an erasing machine having a rotatable chuck, comprising an elongated solid body of erasing material having one end portion to be received in said chuck with the remainder of said body coaxial with said chuck and its opposite end free for application to the work to be erased, said opposite end and said remainder of said body being non-circular in cross-section and v symmetrical about the lon itudinal axis of said body and presenting an external surface with a plurality of reentrant portions extending at an, angle to the direction in which the eraser is ro to be received in said chuck with the remainder of said body coaxial with said chuck and its opposit'e end free for application to the work to be erased, said remainder of said body being of substantially cylindrical shape and having a plurality of substantially equally spaced external grooves extending lengthwise thereof to said opposite end whereby rotation of said eraser by the chuck serves to exert a plurality of successive erasing actions on the surface which it engages during each revolution of the eraser.

3. An eraser for an erasing machine having a rotatable chuck, comprising an elongated, solid body of erasing material having one end portion to be received in said chuck with the remainder of said body coaxial with said chuck and its opposite end free for application to the work to be erased, said remainder of said body being of substantially cylindrical shape and having a plurality of substantially equally spaced grooves extending helically around the exterior thereof to said opposite end whereby rotation of said eraser by the chuck serves to exert a plurality of successive erasing actions on the surface which it

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