US1853065A - Drawing board top - Google Patents

Description

April 12, 1932.. w LONG- 1 1,853,065

DRAWING BOARD TOP Fi led Dec. 27, 1930 Mzfarwey.

Patented Apr. 12, 1332 I UNITED ST TES PATENT OFFICE WILLIAM H. LONG, or CHICAGO, ILLINOIS DRAWING BOARD TOP Application filed December 27, 1930. Serial no. 505,049.

blueprints can beproduced therefrom; wherefore suchpencil drawings are then invariably inked in, thereby requiring a repetition of work, a nd involving considerable time and labor and expense to produce the finished drawing with sharp lines suitable for making blueprints and photostats with clear cut lines therefrom .It is the prime object of my present invention to furnish a drawing board with a resilient and yieldable upper face portion or top, whereby so clear and distinct a drawing can be produced by the use of the drawing pencil alone, and by only the one drawing operation, so that blueprints and photostats can bemade directly from these pencil drawings with very clear and distinct lines, which are as clear and distinct as the lines in blueprints and photostats made from the usual ink drawings, and which are uniform and even throughout; whereby considerable saving is accomplished in time and labor and exense. p Another object of this invention is to provide a drawing board top which is yieldable to the action of the pencil so that depressed linesor grooves are produced by the pencil in the drawing paper, in order that the pencil lines will be distinct and clear and of uniform strength throughout and will not smudge across the paper, but will be fixedly retained in said grooves for permanent record.

Still another object is to provide such a top which has an upper face portion uniformly yieldable to the action of the pencil,

so as to increase the life of the pencil; and which is made of live material to promptly and fully rebound. after being depressed, thus always presenting a smooth top surface.

A further object is to provide a drawing board top or upper face means which, besides tacks or brads.

being resilient, also has a highly finished top surface which is tough, stain-proof, scratchproof, and is washable with soap and water. v These and other objects, and advantages are attained with this invention, as will become apparent from the'following'description, taken in connection with the accompanying drawings, in which, I

Fig. 1 is a perspective view. of a drawing board having my novel upper face means or top mounted thereon.

Fig. 2 is an enlarged vertical sectional view thereof, taken on line 2-2 of Fig. 1.

Fig. 3 is a perspective View showing a drawing board having my resilient top meanssecured thereon, in the form of an inlay, also. illustrating the preferred manner of retaintrating how the-pencil depresses the drawing paper into the pliable and resilient surface means of this resilient top.

In the drawings I have illustratedmyinvention in its-preferred form, and have shown two of the different manners of applying it to a drawing board, so as to constitute the active upper face portion or top thereof.

' This novel top may be secured upon the drawing board by means of tacking element-s, as indicated in Fig. 1,'sho wing my top 10 which is secured on the drawing board 11 by means of tacking elements 12, like thumb This top may furthermore be secured upon the board by the use of cementing means, as indicated in Figs. 3 and 4, showing the top 20 which is cemented upon as indicated in Figs. 1 and 2; and in this case the upper edge portions 10' are preferably 'inga sheet of drawing paper thereon with v per face portion or active top part thereof,

My novel upper face member or top is made uniformly resilient and so as to provlde a live mass which is uniformly y eldable throughout its entire surface area to the action of the drawing pencil used thereon, so

as to be slightly depressed thereby and insure a sharp, even and unbroken pencil line which is of uniform strength and thickness throughout. For this purpose I preferably provide a resilient main partor body portion and cover or coat it with suitable coating means which ',-Wlll exclude the air therefrom and prevent deterioration of said body portion; and this coating means on the top face thereof being furthermore made flexible so as to yield along with said body portion un der the pressure of the pencil on drawing paper mounted upon my improved top.

The substances or ingredients which I have found most desirable for making this body portion or main part 30 of my novel top comprises finely ground cork and wood flour, as indicated at 31 and 32 respectively, in Fig. 2, and which is mixed and bound together with oxidized linseed oil. This mixture is then preferably secured on fabric 33, as burlap, being run thereon as a substantially pasty mass, said fabric providing strength to said body portion. This combined material and burlap is then calendered, thereby pressing the mass of material into the fibres of the burlap, and making the top surface of the mass or body smooth and even.

This combination of the body 30 and fabric 33 is then provided with a coating on both the top and the bottom faces and the edges, to fully seal the pores of the material on its outer surfaces. Said coating means preferably comprises lacquer, especially for the top face and edges, as indicated at 34 in the drawing, and this coating is preferably applied by causing the lacquer to flow over the top surface, and to r un over the edges. -The lacquer is then smoothened off with a scraper. The reinforced body may also be dipped or immersed in the lacquer bath, to completely seal the surfaces of the top member, and more particularly to seal the upper face and the side edges.

The lacquer used herefor must be a flexible and durable one,so that it will yield along with the resilient body means, and will be returned thereby to its original smooth and even surface position, when the pressure of the pencil is removed therefrom.

The next step in preparing my improved tops is to paint the burlap on the lower face, for which the usual oil paint 35 is satisfactory, whereby to seal the lower or back face of my novel top member. The paint is less expensive than the lacquer and will suflice for sealing the burlap which covers the lower face and which is secured upon the drawing board.

.This face member or top for the drawing board is then stored and cured in a suitable room or storage place, being submitted to the ordinary room temperature for about sixty days, whereupon this novel pliable top is ready to be mounted upon a drawing board,

to serve as the active upper face member or top thereof.

In Fig. 4., as in Fig. 2, the body 30 comprises the ground mixture of cork and wood flour 31 and 32 respectively, which is mixed with linseed oil and secured on the burlap 33, the same being coated with lacquer 34 over the upper surface, and painted beneath with paint 35. This top is herein shown fixedly secured on the drawing board with cementitious material 22. 1

In order to avoid having my novel top pierced and marred by the use of thumb tacks for holding the drawing paper on this top, I especially advise and recommend the use of adhesive tape, preferably surgeons adhesive tape, as shown at 36 in Fig. 4, said tape being secured across the corners of the drawing sheet 37 for holding it in position. The adhesive tape is readily removed and a clean surface again provided on my top, since by the use of the lacquer this top surface of my invention is made highly finished and very smooth and tough, it being thereby washable with soap andwater to be readily kept clean.

This top is furthermore rendered so tough upon its upper surface as to be scratch proof, and is so highly finished and smooth that it is actually stain proof, so as not to absorb or permanently retain ink spots thereon.

In Fig. 4 I have further indicated how the live and resilient material of the body portion 30, and likewise the flexibility and yieldability of the lacquer coating on the top surface, will admit of being depressed by the drawing pencil 38, so as to depress the surface lacquer, substantially as shown at 34 in Fig. 4, and to? form a depression or groove 39in the paper 3 The depression 39 in the drawing paper is sufficiently deep and pronounced to cause a deposit of lead from the pencil 38 therein which will be of uniform thickness and strength throughout and will form clean-cut edges along the upper edges of the groove; and which is retained in this deepened groove or trough-like channel in the drawing'paper, so that it is held therein and will not smudge or smear across the paper whenever the hand moves across the drawing, as is the case in drawings made on the usual wooden drawing boards.- These dee grooves will furthermore retain the lead t erein so as to form a permanent record of these encil drawings, and thereby further obviating the necessity of inking in the drawing over the pencil lines,

' as is required in the usual drawings as heretofore provided on .the generally used drawin boards. I

is novel top is furthermore made of a very light color, preferably a white color, sov

that the details on the drawin paper positioned thereon can be clearly 'stinguished.

From the above it is apparent that in drawing boards equipped with my novel top, it is only necessary to execute the drawing in pencil andlno inking in is required; and that the depressed and grooved pencil lines become very strong and-stand out sharply along the edges of these grooves,v so that the are not distinguishable from ink lines, in b ue prints made herefrom, as has been continuously proven by the repeatedv trials with my improved and novel top, especially with this ed as herein disclosed.

. I claim as my invention:

1. In a drawing board, a board member having a top thereon comprising a resilient finally developed top prepared and constructmain portion including a combination off ground cork and wood particles bound together with linseed oil,--and a covering ma'-' terial for covering the outer surfaces of said main portion, the layer of covering material on the top face of said portion being composed of flexible lac uer, thereby providing a smooth and yielda le u per face which is uniformly resilient throu out.

outside of said fabric to fully close the pores on said lower face, and a coverin layer of flexible material which covers the working face of and merges with said body portion, thereby producing a tough and'smoot specification. F 1 WILLIAM H. LONG.

upper surface which is scratch-proof and stain- 2. Ina drawing boar a board member and a top member mounted thereon, saidtop member includinga main body portion provided of resilient material, a layer of fabricsecured to said bodytportion and whereby it is mounted upon sai board member, and a covering layer of lacquer-which merges into the materialgofthe bodfy portion and fully closes the pores thereo whereby-Ya pencil can make a'grooved channel in paper mounted thereon, and dggress it'into said covering layer, so as to m e a sharp pencil line of. uniform strength within said gr ooved channel, providing clear-cut edges on said line adapted to provide a permanent record and to enable making clear and distinct blue prints therefrom. v

3. In a drawing board, a supporting member of comparatively rigid material and a top member secured thereupon to provide the worln'ng upper face portion of the drawing 'board, said top member comprising a main body portion of ground cork and wood flour combined with linseed oil to provide a live and uniformly resilient mass of material, a

- layer of reinforcing fabric wherein the lower facerofrsaid body portion is. merged, a cdating of covering material provided over the

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