US2842791A - Blackboard eraser - Google Patents

Description

July 15, 1958 s r 2,842,791

BLACKBOARD ERASER Filed 001;. s, 1956 I ATTDRN EYE BLACKBGARD ERASER Lowell Statler, Bellevne, Ghio, assignor of one-third to The Joseph Dixon Crucible Company (American Crayon Company Division}, .iersey (lit-3:, N. 31, a cor poration of New Jersey Application October 3, 1956, Serial No. 613,666

1 Claim. (Cl. 1--2tl9) This invention relates to an eraser, and more particularly to a blackboard eraser.

The object of the invention is to provide an eraser which is especially suitable for erasing chalk from blackboards in schoolrooms or the like, the eraser including a sheet or layer of leather or cowhide having a plurality of pores or openings therein.

Another object or" the invention is to provide a blackboard eraser which includes a sheet or layer of suitable material such as cowhide which is provided with a plurality of openings or pores whereby an abrading surface is provided for facilitating the removal of chalk from the blackboard, and whereby the chalk can be readily removed from the eraser as when the eraser is to be cleaned.

A further object of the invention is to provide a blackboard eraser which is extremely simple and inexpensive to manufacture.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are used to designate like parts throughout the same:

Figure 1 is a side elevational view of the blackboard eraser, constructed according to the present invention.

Figure 2 is a bottom plan view of the blackboard eraser.

Figure 3 is a sectional view taken on the line 33 of Figure 2.

Figure 4 is a sectional view taken on the line 44 of Figure 1.

Referring in detail to the drawings, the numeral 19 designates a base or hand grip which can be made of any suitable material such as plastic, and the base ill includes a rectangular portion 11 and a pair of spaced apart side portions 12 which are recessed at 13 so as to define hand grips.

Arranged contiguous to the base Ill and connected thereto is a block 14. For connecting the block 14 to the base 10, a pair of slots 15 are arranged in the block 14, and inturned flanges 16 on the base It) engage the slots 15.

There is further provided a layer or sheet of yieldable material 17 which may be made of any suitable material such as sponge rubber, and the layer 17 may be secured to the block 1 by a coating of glue or adhesive. There is further provided an outer layer 18 which is secured to the layer 17, and the layer 18 may be cowhide or leather, the layer 18 being provided with a plurality of pores or openings 19 whereby these pores 19 will receive or retain the chalk as the eraser is moved along the blackboard. Then, when the eraser is to be cleaned, by tapping on the eraser, the chalk will readily fall out of the pores 19. The ends of the layers or strips 17 and 18 may be tapered or beveled as shown in the drawings so as to help insure that the layers or strips will not accidentally catch on any objects.

2,842,?9l Patented July 15, 1958 From the foregoing it is apparent that there has been provided an eraser which is especially suitable for use in erasing or removing chalk from blackboards in schools, homes and the like. In use, the base 10 is gripped in the hand and the cutaway portions 13 provide clearance for the comfort of the fingers of the hand. Then, when the eraser is moved over the blackboard containing the chalk, the'chalk will be removed from the blackboard and some of the chalk will be retained or received in the pores 19. Due to the provision of these pores H, the layer 18 is provided with an abrasion-like surface which facilitates the removal of the chalk from the blackboard. Also, the holes or pores 19 can be readily punched in the material 13 in any suitable manner, as for example by means of a suitable needle. After the chalk has been removed from the blackboard, or when the eraser becomes saturated with chalk, the eraser can be tapped against the wall or a suitable object can be used to tap the base 1% so that the chalk will readily fall from the pores 19 whereby the eraser can be used over and over again.

The base 10 can be made of any suitable material such as plastic, and the material 13 can be heavy cowhide and the sheet of material 13 can be secured in place by means of a suitable adhesive. The block 14 can be made of Masonite or plywood or the like. Thus, it will be seen that there has been provided a blackboard eraser which includes the base or handle 1d which can be conveniently gripped in a persons hand and the base 10 may be hollow as shown in the drawings. The flanges 16 are snugly seated in the recesses 15 in the block 14- so that the parts can be readily detached when desired. The yieldable layer of sponge rubber 17 pro vides a resilient backing for the layer of leather or cow hide 18 which has the pores or openings 19 therein. As previously described there is a great many or" the pores or openings 19 and these pores or perforations l9 may be made by means of a suitable needle or the like.

While it has been proposed to use leather in prior blackboard erasers, it has been recognized that heavy tough leather soon polishes and becomes useless as an eraser. Furthermore, soft weak leathers do not have enough bite and soon wear out. in the present invention a tough hard leather is used but the cell structure is broken up all the way through by means of the perforations 19. For example, there may be as many as 60,090 holes or perforations 19 in the layer of leather 18. The provision of the openings 19 serves to make the leather soft and spongy but still retains the hard grain so that it has sufiicient bite to erase the chalk easily. Thus, the leather will wear rough instead of polishing.

When ordinary leather is used on a blackboard eraser it has a tendency to develop a glaze on it and polish. But with the present invention the eraser develops a nap on the leather which remains permanently. it to be understood that the size and shape of the parts can be varied as desired and the device can be made of suitable material. With the present invention the eraser will not leave a film of chalk on the blackboard after the blackboard has been erased. A suitable die can be used for forming the openings 19 so as to tear the tissue of the leather. Thus, the leather is changed from a hard layer of material to a soft spongy layer of material.

I claim:

A blackboard eraser comprising a hollow base embodying a rectangular portion, said base further including a pair of opposed spaced apart side portions provided with recesses so as to define hand gripping portions, a first layer of yieldable material arranged contiguous to said base and operatively secured thereto, a second layer of material extending along the outer surface of said first layer of material and secured thereto, said first layer of material being sponge rubber, said second layer of material being leather and said second layer of material being provided with a great number of minute spaced apart pores therein which are arranged closely adjacent to each other, said pores extending all the way through the second layer of material so as to create a spongy structure having a roughened working surface.

References Cited in the file of this patent UNITED STATES PATENTS Andrews May 15, Palmer Oct. 1, Barrie May 18, 0xley July 22,

FOREIGN PATENTS Great Britain of

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