US1933366A - Eraser - Google Patents

Description

E. A. CLAVEY Oct. 31, 1933.

ERASER Filed Oct. 17, 1952 EJn/QVJ Cyan/ef @www Patented' Oct. 31, 1933 fsf-rara "Para 'Edward A. Clavey,'Park Ridge, Ill., assigner to A. Etowlcs Co., Chicago, Ill., a corporation of Illinois Application October 17, 1932. Seria'lrlo, 638,158 y I A8` Claims. (Cl. 15-223) `This invention relates to certain new and useful improvements in a noiseless eraser made, entirely of non-resonant lmaterial, and so constructed as to afford a maximum of wearing and dust-removing qualities and at the same time be capable of economical and-rapid manufacture.

- surface.

:The invention relates to certain improvements v. on the type Vof eraser disclosed in the patent tomaterialwhich is reinforced by a fabric covering fibrous slabl and the' fabric covering Wrapped around the slab and glued thereto. The felt erasingistripsare secured to the back-piece Yby' lines of stitching which pass throughboth the iny the novel manner hereinafter set, forth..

v .v The principal object of this invention is to provide anr improved eraser ofthe type briefly described.hereinaboveand disclosed more in detail in the: specifications which follow.k

' Another object is to provide an' improved backpiece for fan eraser.

Other objects and advantages .of this inventionv will be more apparent from the following detailed description of vone approved'form of eraser constructed accordingfto the principles of this invention. y

Irl-the accompanying drawing: I Fig. `1 is aperspective View of the complete Fig. 2 is a perspective View showing aninitial step in the constructionfof the eraser.

Fig.'3 isa perspective 'vies/"showing a succeeding step in the assembly of the eraser parts'.

Fig. e is a partial perspective view of the imn Fig.' is a ltransverse section through the as'- f sembled eraser.V f

The eraser comprises a relatively stiff` back.; piece or handle A and a plurality of strips of felt or similar erasing material indicated generally atB, these strips being attached to and supported by the back-piece A. The improved back-V lpiece A comprises 'an innerv slab'v 1 of a rather isoft'and Vlight fibrous material, for example a wood fiber product such'as isknowncommerciallyfas quarter-board?. Thisproduct is light, cheap, and non-resonant, but does not in itself possess the requisite strength and wearing quali-l ties to support the erasing strips B. The slab 1 is covered, except at the-endspby a-sheet V210i relatively tough fabric, preferablyfcanvas, which is wrapped tightly' about .the slab and, glued ses surely thereto. Preferably the meeting portions 3 and i of the fabric sheet 2 are overlapped and glued upon oneanother Aalong one vflat facefof the slab,; preferably the bottom the1eof.y The overlapped portions need not cover the-y entire lhat face vofv the slab, but Vthese overlapped portions are preferably `of sufflcientextent so that at least two of the lines of stitchinghereinafter referred to will pass through the double thickness of canvas on the bottom of the slab.

p In theexample here shown the erasing portion B comprises xed strips 5, 67, 8, 9-and 1.0 ofi-felt or similar material', which strips arearranged in Contact with one'anotherand at substantial right angles to the .bacl piece A so that the free lower edge portions of ,theV 'strips lie in substantially the same plane and fornrthe erasing surface.

@ne of the outer strips, for example strip 5, is l laid flatwise against the lower lsurface vof the back-pieceA (which is inverted.y asshown in Fig.`

i!) with the outer edge 129i ,the strip substantially aligned with thefouter edgeportion l13 ofthe` back-piece. The strip is then secured ,to `the backpiece by a line of stitching 11 extending llongitudinall'y of theeraser andlparallel to the edge portions 12 and 13 and extending entirely through the strip 5, from the outer face thereof, and through both the slabv 1 and fabric covering 2 of Vthe back-piece.Y The otherouter strip 10 is now securedy to the opposite edge portion of the back-piece in a similar mannerrby a similar line of stitching 14.

The outermost strips 5 and 10 are now bent up J as indicated in Fig. 3 and the intermediate'strips -6` tov9 aremounted on the back-pieceY between these outer strips. These inner strips are formed in. pairs, Aa sheet 'of felt of substantially twice the widthof one of thestrips or l0 being folded longitudinally-upon` itself *to form a pair of ad jacent strips such as' 6 and 7. Thispair of strips is securedv to the back-piece by a line of stitching lpassing through the back-piece andthe folded portion of the felt member V'between the adjacent strips. of the pair. While two pairs of intermediate vstrips 7, and 8, 9 are here'shown,it will 'be apparent that three or more pairs of such intermediate' strips could be yused'and the width of the eraser increased accordingly.

.It will be apparent that the outwardly folded outer strips 5 and l0 exert an inward pressure on the intermediate strips tending to holdvv the assembly rmly together, and the mutual engagement ofthe assembledstrips tends toA prevent attening out of the., free rubbing edge portionsr thereof. 4At thevsame timel a limited freedom of movementis permitted between the strips so that 4 of the fabric covering.

a resilient and effective rubbing surface is provided.

The canvas covering 2 gives the requisite strength and rigidity to the relatively soft and fragile brous slab l which forms the ,main body portion of the back-piece. The lines of stitching pass completely through the back-piece so that` the fabric covering will prevent the stitches from pulling through the relatively soft slab l. Preferably at least two of the lines of stitching 1l, 14 or 15 pass through the overlapped portions 3 and This effectively pre.- vents splitting of the back-piece when subjected to the bending stresses encountered when in use.

A Yback-piece constructed in this manner is very light and noiseless, and may be quite cheaply and rapidly constructed. At the same time it has the requisite strength, and stiffness to firmly and permanently support the felt erasing strips, and provides a very satisfactory handle having a good gripping surface.

`rWhile thecanvas covering 2 has been designed for the primary purpose of adding the requisite strength `and stiffness to a fibrous slab l which in itself is too fragile for successful use without the canvas covering, it will be understoodthat the same covering will be useful to enhance the strength of a stronger fibrous slab, for example, a slab of feltas heretofore known and used in this type of eraser. Although felt has been used as a back-piece with some success, without the fabric covering, the felt slab is weakened by the lines of stitching and will sometimes break along these lines, and the canvas covering will reinforce and stiffen such a felt slab in the manner hereinabove set forth. Y

A plurality of these erasers may be simultaneously formed by first constructing a long strip in the manner hereinabove described and then cutting this strip into suitable lengths to form the finished erasers.`

It will be apparent that this eraser is entirely free from any-substance which can either injure the blackboard or be capable of making any objectionable sound.

` The felt'strips'might be attached to the backpiece in other manners than that herein disclosed, but the form here shown is preferred since the lines of stitching add strength and rigidity to the back-piece and securely hold all'of the parts in assembled relation.

I claim:

l. An Yeraser comprising a non-resonant backpiece, and a plurality of strips of resilient erasing material positioned in contact with one another and secured to the lower face of the back-piece by lines of stitching, the back-piece comprising a slab of fibrous material and a fabric covering lwrapped around the slab and glued thereto, the lines of stitching passing through both the brous material and the fabric.

2. An eraser comprising a non-resonant backpiece, and a plurality of strips of `.resilient erasingA material positioned in lContact with one another and secured to the lower face of the back-piece by lines of stitching, the back-piece'cornprising a slab of fibrous material and a sheet 'of fabric wrapped around the slab and glued thereto, the

it i

stitching passing through the overlapped portions ofthe fabric.

3. An eraser comprising a non-resonant backpiece, and a plurality of strips of resilient erasing material positioned in contact with one another and secured to the lower face of the back-piece by lines of stitching, the back-piece comprising a slab `of fibrous material and a sheet of fabric Wrapped around --the slab and glued thereto, the meeting portions of the sheet being overlapped upon the lower vflat `face of the slab,l the lines of stitching passing through both the fibrous materialV andthe fabric covering, and some of the lines of stitching passing through the overlapped portions ofthe fabric. Y

4. An erasercornprising a non-resonant'bac'kpiece formed of a slab ofbrous material and a sheet of fabric wrapped therearound and glued thereto with the meeting portions of the sheet overlapped upon one flat face of theslab, and a plurality of stripsl of felt positioned closely adjacent one another so as to provide a mutually elastic support, the lower erasing edge portionsfof the strips projecting at' substantial right angles from the lower face ofthe back-piece, the upper edge portions of the Voutermost strips being sewed from the outer sides of the strips through the back-piece, the strips being then folded outwardly, and the inner strips being formed in pairs `each pair being folded from a single piece of felt and the pair being sewed to the back-piece bya' line of stitching passing through the folded portion between the strips of the pair, all of the lines of stitching passing through both the fibrous slab and the fabric covering, and some of the lines of stitching passing through the overlapped portions of the fabric.' f

5. An eraser comprising a non-resonant back# piece Vformed of a slab of soft brous material and a reinforcing sheet of fabric wrapped around the slab and glued thereto with the meeting portions of the sheet overlapped upon one 'fiat face of the slab, and a plurality of strips of felt positioned closely adjacent one another `so as to provide a mutually elastic support with the'lower 120 erasing edge portions of the strips projecting at substantial right angles from the lower face of the back-piece and the Vupper edge portions of the strips secured to the back-piece.

6. An eraser comprising a non-resonantbackpiece formed of a slab of soft brous material and a reinforcing coveringrof fabric glued thereto, and a plurality of strips ofv felt positioned closely adjacent one another so as to provide a mutually elastic support with the lower erasing edge portions of the strips projecting at substantial right angles from the lower face of the back-piece'and the upper edge portions of the strips secured to the back-piece.

7. A back-piece for an eraser comprising a sla of fibrous material and a fabric covering Wrapped tightly around the slab and glued thereto, the meeting portions of the fabricA covering being overlapped and glued upon one another along one at face of the slab. Y

aA back-piece for an eraser comprising a slab of wood nbre and a canvas covering wrapped tightly around the slab and glued thereto, the meeting portions of the canvas covering being overlapped and glued-upon one another aloner one flat face of the slab. Y

EDWARD A. CLAVEY.

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