US2212703A - Drawing instrument - Google Patents

Description

Aug. 27, 1940. r c. M. SUFFICH 2,212,703

DRAWING INSTRUMENT Filed Feb. 9, 1938 Patented Aug. 27, 1940 UNITED STATES rem OFFICE- 3 Claims.

The object of my invention is to provide an improved drawing instrument of extremely simple character, which may be used by draftsmen to easily and "conveniently draw a series of parallel lines; the invention being particularly meritorious in that with it a plurality of parallel irregular curved lines may be drawn quickly and accurately. These parallel curved lines may be used to an advantage as a guide on which to place lettering.

It is well known to those skilled in this art that it is time consuming, tedious and a dimcult task to draw a series of accurately spaced irregular curved lines. With my improved instrument, this may be done with accuracy and dispatch simply by properly operating the instrument along the straight or curved edge of any of the drafting instruments now used by draftsmen in connection with proper positioning of a scribing or marking element, such as a pencil, upon the instrument.

Other objects and advantages of the invention will be apparent during the course of the following detailed description.

In the accompanying drawing, forming a part of this specification and wherein similar reference characters designate corresponding parts throughout the several views,

Figure 1 is a plan view of the instrument.

Figure 2 is a section of the same.

Figure 3 is a plan view of the instrument in use on the top edge of a T square.

Figure 4 shows the instrument in use on a lower edge of a T square.

Figure 5 shows the instrument applied to the upper edge of a section of a draftsmans scroll.

Figure 6 shows the instrument applied to the lower edge of a section of a draftsmans scroll.

In the drawing the letter A designates the instrument, hereinafter designated as a disk, which may be made of pyroxylin, synthetic resin, wood, metal, fibre, hard rubber, or any approved material such as the various angles, irregular curves and templets of engineers and draftsmen are made. In the preferred instance, it is of transparent material, such as synthetic resin or pyroxylin and is disk shaped and of uniform thickness. This instrument may be made in different sizes vto suit the purpose of the engineer or draftsman, as is the common practice in making draftsmans instruments. In the preferred instance, the shape of the instrument forming the subject matter of this invention, is in the shape shown in the drawing, i. e., a disk, but this shape may be departed from without departing from the broad conception of the invention. The only demand is that the instrument be substantially round so that it will follow closely the shape of the drafting instrument which guides it.

The disk A has a series of lines I printed or etched thereon, which radiate from the central point of the disk, thus dividing the disk into sectors. Each of the sectors of the disk has therein a series of openingswhose arangement and function will be described in detail. The 1 openings in the disk A are made tapered, as

- shown in Figure 2, so that the point of a lead pencil D may be easily inserted into the desired opening. The openings in each sector of the disk are of different arrangement so that a L ing distances. The same is true of the holes in the disc designated as 5. In other words, in each sector of the disk the only holes that correspond are those designated as 2, While those designated as 3 to 5 inclusive are in different arrangement in that they have various distances from the edge of the disk A.

While I have shown only 4 openings or holes in each sector of the disk A, the number of openings in each sector may be materially increased, the only limitation on the number of openings in each sector is that no openings should be closer to the center of the disk than one-half the distance of the radius of the disk. This is because the instrument will have a tendency to turn, rather than slide, if the opening used is much beyond the limit indicated above. Each sector of the disk should have printed or etched thereon figures or symbols, designating the arrangement of the opening in that particular sector, so that the user of the instrument can ascertain at a glance the arrangement of the particular openings he desires to use. Of course, the openings in each sector of the disk could be arranged in a line, as opposed to the grouping shown, thus accommodating a larger number of different openings on the same size disk.

While I show in the drawing, forming a part of this application, the disk lined oii in 8 sectors, the number of sectors can be materially increased, the only disadvantage in such increase of sectors being that the user of the instrument will find it more difficult to ascertain at a glance the desired group of openings that he wishes to use.

The object of the invention is to permit the easy scribing of parallel lines, which parallel lines may be used for the base on which to letter, without the necessity of shifting the other drafting instrument used in combination with this instrument. The other drafting instrument may be a T square like that shown in Figures 3 and 4, or a draftsmans scroll like that shown in Figures 5 and 6.

To use the drawing instrument forming the subject matter of my invention, the draftsman selects the group of openings which will make the desired spaced parallel lines wanted. Then having selected a '1 square, curve or templet, hereinafter called a base, which base has an edge that corresponds in shape to the parallel lines desired, he places the base having the desired edge on paper in a position so that the lines to be formed will be made in the place desired. Then after placing the drawing instrument of this invention either above or below the desired edge of the base, he places a pencil in one of the openings in the sector closest to the base and moves the drawing instrument the desired distance, thus forming a line parallel to the base. Naturally the number of lines thus formed is governed by the number of times this operation is performed, and their position in relation to each other by the openings selected.

The disk, on account of its shape and hard material of which it is made, slides and easily follows the contour of any of the well-known drafting instruments, as will be seen by looking at Figures 5 and 6 of the drawing wherein the disk is on the upper and lower edges of a draftsmans scroll. It is evident that the drawing instrument of my invention, because of its shape, will follow abrupt curves more closely and more accurately than does the square or rectangular drawing instrument heretofore used for the same purpose.

I claim:

1. A drawing instrument in the form of a disk, the plane surface of said disk being marked to designate sectors, openings grouped in each sector entirely around and adjacent the peripheral edge of the disk, none of said openings being closer to the center of the disk than one-half of the radius.

2. A drawing instrument of the type employed with a curved edge base and adapted to be slid along said base, comprising a disk with openings therein, said openings being arranged in like groups around the periphery of the disk, the corresponding openings of the diiferent groups, except the opening forming the base of the groups of openings, being spaced from the peripheral edge of the disk in unlike distances with none of the openings of the several groups being closer to the center of the disk than one-half of the radius.

3. A drawing instrument comprising a circular disk with openings therein arranged in groups entirely around the same adjacent the periphery thereof, the surface of the disk in the center area being entirely void of openings.

CORNELIUS M. SUFFICI-I.

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