US709722A - Blackboard-eraser. - Google Patents

Description

No. 709,722. Patented Sept; 23, I902.

F. U. RABER.

BLACKBOARD ERASER.

(Application filed Mar. 31, 1902.)

(No Model.)

Tu: mums PETERS co PHOTO-LITHO WASNINUTON, D10.

t UNITED STATES FRANKLIN G. RABER, OF AKRON, OHIO.

BLACKBOARD-ERASER.

SPECIFICATION forming part of Letters Patent No,

709,722, dated September 23, 1902.

Application filed March 31, 1902. $erial1lo. 100,793. (No model.)

To all whom; it may concern:

Be it known that I, FRANKLIN O. RABER, a citizen of the United States,residing at Akron, in the county of Summit and State of Ohio, have invented a new and useful Blackboard- Eraser; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. Y

This invention relates to improvements in blackboard-erasers; and the object is to provide a dustless eraser-that is, one that will not scatter the chalk-dust during the opera tion of cleaning the board.

I am aware that blackboard-erasers have been invented heretofore which are claimed to be dustless; but in practical use the erasive material of which they are constructed becomes laden with the chalk-dust, and thereafter when the eraser is used the contacting of the same with the blackboard when the former is placed in position for erasing causes the dust stored therein to be forced therefrom, which dust floating about in the room renders it very unhealthy for the pupils, subjecting them to the liability of contracting, throat and lung diseases.

My invention isdesign ed to obviate the defect above set forth, and this result is accomplished by providing the eraseron its erasive face with a rim of a flexible material which will not absorb or become laden with the chalk-dust, said rim being so arranged as to contact with the blackboard when the eraser is placed in position for erasingand makethe space surrounded thereby practically airtight, thus preventing the dust from scattering. The force of the contact with the blackboard also being upon the rim, the erasive material is not compressed and the dust forced therefrom.

\Vith the above object in View the invention consists in the novel features of construction hereinafter fully described, particularly pointed out in the claims, and clearly illustrated. by the accompanying drawings, in which- Figure l is a perspective view of an eraser constructedin accordance with myinvention; Fig. 2, a bottom plan View of the same, and Fig. 3 a transverse sectional View.

Referring now more particularly to the drawings, 4 designates the body of the eraser, to one side or face of which a plurality of 1on gitudinally-extending strips 5 of felt or simi lar material are secured. These strips are spaced from each other, as illustrated, and are of a number and length to leave a space at the ends and sides thereof.

Secured about the side and end edges of the body and disposed in the spaces at the sides and ends of the erasive material 5 are strips of flexible non-dust-absorbing material 6, so placed as to form a continuous rim about the edges of the body. Theinnerand outer faces of the strips forming this rim are beveled toward the outer edges thereof, and said strips at said outer edges project a slight distance beyond the outer faces of the strips of erasive material 5, as illustrated in Fig. 3. When the eraser is placed in position on the blackboard for erasing, the projecting edge of the rim first contacts therewith, forming a practically air-tight contact between the eraser and the board and preventing the dust from escaping from the erasive material inclosed thereby. The yielding rim also receives the force of the contact between the eraser and the board, so that the felt erasive strips are not compressed and the dust forced there-.

from. Any dust which might be forced from the felt strips would pass into the chambers 7 formed between the erasive surface and the strips constituting the rim.

While in the present instances the erasive strips are formed of felt and the rim of spongerubber, yet I do not limit my invention to the materialused, as other materials may be used Without departing from the spirit and scope of the invention.

Having thus described my invention, What I claim as new, and desire to secure by Letters Patent'of the United States, is

1. A blackboard-eraser comprising a body carrying an erasive surface, and a rim formed of a n0n-dust-absorbingmaterial surrounding said erasive surface and projecting beyond the outer face thereof, substantially as described.

2. A blackboard-eraser comprising a body carrying an erasive surface, and a rim formed ofa non-d ust-absorbing material surrounding said erasive surface and spaced therefrom, substantially as described. a

In testimony whereof I affix my signature in the presence of two witnesses.

FRANKLIN O. RABER.

Witnesses:

CLARA-L. SMITH. H. O. PARSONS.

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