US1825858A - Blackboard eraser - Google Patents

Description

Oct. 6, 1931. 3

A. A. ELNE TT BLACKBOARD ERASER Filed Aug. 9, 1930 INVENTQR BY ATTORNEY gfw/Wlw/yfff A V 4 MO. amw wd v Patented (let. 6 1931 PATENT OFFICE ANTHONY A. ELNETT, 01 NEW YORK, N. Y. Y

- BLACKBOARD nrmsnn Application filed August 9, 1930.?Seria1 No. 474,244, i

This invention relates to black board erasers in general and more especially to :erasers for black boards composed of slate or the like. i

5 With black boards composed of slate such J) white crayon marks formed thereon.

as extensively used in the schools of the United States today with which white crayons composed of chalk are used as the mark producing or character producing medium, 0 it has been customary touse erasers composed or felt or the like for cleaning the slate, that is for removing the marks formed on the slate by the crayons aforesaid. When such felt erasers are used, it has been found necessary as frequently as once a day, to use water or the like for washing the slate, otherwise the slate would shortly become so light in hue, that it would'be difficult at the ordinarily required distance to distinguish the Slate, however, is porous and it has been fund that while this water washing serves one purpose, the water actually helps to impregnate the poresof the slate with the chalk particles so that in time the pores will become so saturated with the resulting chalk paste that notonly will the color of the slate be changed to a lighter shade and the legibility materially impaired, if not entirely destroyed, but in 3 addition, the surface of the slate will be so changed in texture that it will not properly allow the chalk particles to form the intended mark or character, some of the chalk particles merely adhering to the spongy chalk paste in the pores and thereby discolored and others being discolored by the moisture of the chalk paste retained in such pores.

In view of the foregoing, it is an object of the present invention to provide an improved black board eraser which will effectively clean the slate of all chalk marks so that water or the like will not be required from,

excess chalk particles to prevent accumulation of'the same in the pores of the slate and actually serve to polish the board.

It is still another object of the present invention to provide an improved black board eraser foreffectively cleaning a black board of all chalk particles formed on the surface as well as those lodged in the pores of the slate and which erasers can'be expeditiously cleaned. V

f It is' still another object of the present invention to provide an improved black board eraser from which the chalk'particles can be quickly and effectively liberated in the act of cleaning such erasers. To-this end, the present inventionmore specifically aims to provide a black board eraser composed of felt and steel wool. v

These and other features, capabilities and advantages of the invention will appear from the subjoin'ed detail description of specific embodiments thereof illustratedin the ac companying drawings in which: 7

Figure 1 is a perspective looking at the bottomof one form of eraser;

Fig. 2'is a transverse section of the eraser illustrated in Fig. 1; and

Fig. 3 is an enlarged transverse section in perspective of another form of eraser looking at-the top. p

In the embodiment illustrated in Figs. 1 and 2 there is provided ablack board eraser made according to the present invention havin a base or supporting sheet 1, composed of felt or the like and two side sheets 2 eraser. These walls 2 and 3 may be secured to can also be used so that the steel wool will serve to polish the surface of the blackboard and thus not only remove the chalk marks but also obliterate any surface" digsor scratches that might be formed in the slate by the crayon. Due to the natural'resiliency of'the steel wool fibre notonly the. felt sections 6, but'also the steel wool sections 9 will be quickly freed'of the chalk particlesin the act of cleaning. These steel wool'sections 9 arealso secured to the base 1; In the present instance,they are. shown as secured by the fibre threads 10.

In the embodiment illustrated in Fig. 3, the eraser there illustrated is provided with a base 11, similar to the base 1 of the aforesaid embodiment, and also preferably composed of felt. To this base 11, there are secured the; side walls 12 and.18, also composed of felt, similar to the side walls 2 and 3 of the aforesaid embodiment. Between the side Walls 12. and 13 in the present embodiment theaeis provided a rectangularblock 14 com posed of felt and steel wool fibre. This block 14 maybe securedto the base 11 or. to' the walls-12 and 13 by any sort of'suitable means.

In: the present instance, the fibre'threads 15 am provided to extend through the base 11 into the block 14. The felt particles of the block llrserve not only as thebinder'for the steel wool fibres'but also asa yieldable safety device, similar in action to the action of a cushion. In this Way in the act of eras ing, the steel wool particles will beprevented from freel rubbingagainst one another and thus abra ing one another without perform ingany useful work. Furthermore; since the steel wool fibre is,- of course, .rnorecoms pneesiblo than the felt particles; the feltparticles will serve as the support to bear the brunt. of theerasing pressure and the steel wool particles will be free to act asa brush, its fine wire threads piercing. the smallest portions to dislodgethe chalk particles that might be retained therein.

The felt-sections 6'of theembodiment. il' lustrated in Fi 1 and 2, will of course similarly serve to ear the brunt of the pressure exercised during the erasing action and similarly permit the steel wool sections; 9 'freely to act as a* brush and-not as a scratching surface.

The block 14 may of course be used as a black. hoard eraser without the base 11 and side walls 12. and 13.

It iaobvious that variouschanges and modtween said-finger protecting walls with the exposed ends thereof terminating in a face parallel with said base, and means securing said finger protecting walls and sections of felt and steelwoolto said base, the felt sections being less compressible than the steel wool sectionsto act asa guard for the surface beingerased.

ANTHONY A. ELNETT.

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