US2149422A - Drafting triangle - Google Patents

Description

DRAFT ING .TRIANGLE Fil d April 14, 1957 5 FIGIl C INVENTOR EL RWCOFFEY ATTORNEY Patented Mar. 7, 1939 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to drafting triangles, such as are used very extensively by draftsmen for making drawings.

In accordance with usual present practice, the

\g equipment of a draftsman consists of at least two trianglesa 45 and a 30 x 60 triangleand a protractor for laying out angles other than those of said triangles.

Objects of the present invention are:

m 1. To provide a single triangle which will provide all the services of the usual two triangles; and

2. To provide a protractor scale on the external, diagonal edge of my improved triangle where it 5 will be readily available for laying out angles other than those which the triangle itself provides.

The invention also comprises the various other features and details of construction, hereinafter described and claimed.

20 In the accompanying drawing, in which a triangle embodying my invention and improvements is fully illustrated,

Fig. 1 is a plan view, on a relatively large scale, of a triangle embodying my invention and im- 5 provements without a protractor scale; and

Fig. 2 is a view on a relatively small scale, of the triangle shown in Fig. 1, formed on which is a protractor scale, arranged in accordance with my invention, to effect the objects thereof.

30 Describing the invention with reference to the drawing and referring in the first instance, to Fig. 1, my improved trianglewhich may be made of Celluloid or other suitable material, has two edges, A-B and BC, which are perpendicular to each 35 other and of different lengths, and a diagonal edge, which connects the remote ends of the perpendicular edges of the triangle, said diagonal edge comprising only two sections, one of which extends at an angle of 30 to the longer perpen- 40 dicular edge of the triangle, and the other at an angle of 45 to the shorter perpendicular edge (01. tie-104) thereof-said sections forming a re-entrant angle and meeting each other at an angle of 195.

Preferably, but not necessarily, the triangle will be cut out as shown at E.

Excepting that the triangle shown in Fig. 2 is 5 provided with a protractor scale formed only on its external, diagonal edge, the foregoing description of the triangle, shown in Fig. 1, will apply equally to the triangle shown in Fig. 2 and the same and corresponding parts are therefore, designated by the same reference characters in both figures.

As shown in Fig. 2, the center point, to which the graduations of the protractor scale are referred, is positioned at the juncture of the perpendicular edges of the triangle, and the graduations thereof are formed on the external, diagonal edge of the triangle, opposite the apex of the angle formed by its perpendicular edges.

While I have illustrated and described the preferred form and arrangement of parts for carrying the invention into effect, this is capable of Variation and modification, without departing from the spirit of the invention. I therefore do not wish to be limited to the details herein shown and described, but desire to avail myself of such variations and modifications as fall within the scope of the appended claim.

I claim:-

A drafting triangle having external meeting edges, which are of diiferent lengths and perpendicular to each other, and an external, diagonal, third edge which connects the ends of said perpendicular edges remote from their meeting point, said third edge comprising only two sections, one of which extends at an angle of 30 to the longer of said perpendicular edges, and the other at an angle of to the shorter of said perpendicular edges, said sections meeting to form a re-entrant angle of 40 ELMER W. COFFEY.

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