US1157718A - Blackboard-eraser. - Google Patents

Description

.I. F. PALMER.

BLACKBOARD ERASER.

APPLICATION FILED JAN.26, 1915.

1,157,?18, Patented ott. 26, 1915.

gwwvt o JOHN F. PALMER, OF MILWAUKEE, WISCONSIN.

BLACKBOARD-ERASER.

Application filed January 26, 1915.

To all whom it may concern:

' Be it known that I, JOHN F. PALMER, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Blackboard-Erasers; and I do hereby declare that the following is a full, clear, and exact de scription thereof.

My invention consists in what is herein particularly set forth with reference to the accompanying drawings and pointed out in the claims of this specification, its object being to provide simple, economical and efficient anti-spreading blackboard erasers that are comparatively dustless in operation.

Figure 1 of the drawings represents a plan view of a pair of united felt-strips embodied in a blackboard eraser according to my invention; Fig. 2, a side elevation of the same; Fig. 3, a plan view of the united strips subsequent to a turning of the same to bring their ends inward; Fig. 4, a similar view of the complete blackboard eraser, and Fig. 5, a cross-section indicated by line 55 in Fig. 4.

Referring by numerals to the drawings, 6 indicates one and 7 another of a pair of felt strips of any suitable length and width united by stitching to have an end of each extend beyond the adjacent end of the other. The stitching is adjacent to opposite ends of the strips and to a longitudinal edge of each, and each stitching preferably forms the outlines of a right-angle triangle, as shown in Fig. 2. The united strips constitute a rubber element of the eraser and after stitching, the product is turned to bring its ends inward and parallel to its straight outer sides. When said product is thus turned, there is a lapping of ends of its two felt strips and a butt-joint of the ends of each strip to complete a pair of pockets into which as many other felt strips 8 are inserted to complete Specification of Letters Patent.

Patented Univ. 26, 1915.

Serial No. 4,493.

the rubber of the eraser, said rubber being then laterally compressed and glued to a backing 9 that constitutes the handle of the completed eraser. In the finished eraser the stitching aforesaid is adjacent to the back ing 9 and the glue-joint is indicated at 10 in Fig. 5. Said backing or handle 9 of the eraser is preferably a strip of felt having a stiffener 11 therein, and the stiffener is preferably a strip of sheet-steel.

The eraser above specified is anti-spreading and the disposition of the stitching of its strips 6 and 7 is such that said strips and the other strips 8 may Wear down for at least one-half of their width before said stitching is effected. More or less of chalkdust from a blackboard finds its way in between the felt strips of the eraser and thus said eraser is comparatively dustless in its operation.

I claim:

1. A blackboard eraser formed of outer strips of felt connected adjacent their ends and shaped to form a pair of pockets separated by a partition, filling strips of felt fitted within the pockets, and a backing attached to the outer strips and to the filling strips.

2. A blackboard eraser formed of outer strips of felt connected adjacent their ends and shaped to forma pair of pockets, filling strips of felt fitted within the pockets, and a stiffened felt backing attached to the strips.

3. A blackboard eraser back comprising a strip of felt having a stiffening strip of other material inclosed therein.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee in the county of Milwaukee and State of Wisconsin in the presence of two witnesses.

JOHN F. PALMER.

Witnesses:

MARY CooeAN, FREDA RUGER.

tl'opiea or this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington. D. G.

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