US2643458A - Drafting implement - Google Patents

Description

June 30, 1953 E, KELLEMS 2,643,458

DRAFTING IMPLEMENT Filed March 5, 1948 2 Sheets-Sheet l INVENTOR EDGAR E. KELLEMS.

r /.1. BY $6M AGENT June 30, 1953 E. E. KELLEMS ?,643,458v

DRAFTING IMPLEMENT Filed March 3, 1948 2 Sheets-Sheet 2 INVENTOR EDGAR E..KELLEMS.

AGENT Patented June 30, 1953 UNITED STATEd PATENT OFFICE DRAFTING IMPLEMENT Edgar E. Kellems, Pasadena, Calif.

Application March 3, 1948, Serial No. 12,790

2 Claims.

The present invention relates to drafting implements.

One object of my invention is to combine several drafting implements into one convenient device.

Another object of my invention is to combine all of the usual drafting angles into one device so that each angle and the device is simple to use.

A further object of my invention is to provide an expanded scale protractor that is extremely accurate in use.

A still further object of my invention is to attain the objects and advantages above enumerated in a one-piece implement.

Other objects and advantages will become apparent in reference to the following specification and attached drawings, in which Fig. 1 is a plan view of my invention;

Fig. 2 is a plan view of the invention showing the use in one position;

Fig. 3 is a plan view of the invention showing the use in another position, and

Fig. 4 is a plan view of the invention showing the use of the protractor.

In the following detailed description of the invention like numerals indicate like parts in the several figures of the drawings. The reference numeral it indicates generally the invention which comprises a one-piece transparent plastic drafting implement having a base portion I l and an upstanding portion I2. The base portion H has a base edge 53 and an upper edge M parallel to the base edge l3. The upstanding portion i? has an inner edge I5 perpendicularly ex tending from the upper edge M of the base por= tion H. An outer edge it of the upstanding portion I2 joins the inner edge id to form an ineluded angle or 30 degrees. A lower edge l! of the upstanding portion I2 joins at one end with the outer edge it to form an included angle of 105 degrees and at its other end joins with the base edge it of the base portion H to form an included angle of 135 degrees.

The upper edge Id of the base portion H is provided with an imprinted measuring scale having its zero point a fraction removed from the inner edge it (if the upstanding portion I2. This location of the zero point permits direct measuring and drawing without moving the implement it. The inner edge E5 of the upstanding portion :12 is likewise provided with a scale with its zero point a fraction removed from the upper edge it of the base portion II. The outer edge it of the upstanding portion I2 is also provided 2 with a scale. Each of the aforementioned scales is marked and numbered in the conventional manner.

A protractor arc is provided on the upstanding portion 12 having as its center the point on the upper edge [A of the base portion ll indicated by the numeral line extending from the C and arrow imprinted on the implement. The protractor scale is numbered for unidirectional use.

In Figures 1, 2 and 3 of the drawings, a portion of a standard T square is indicated as H3.

In Figure 4 of the drawings, a base line, from which a specific angle is to be drawn, is indicated by a dash line extending across the figure. It is to be noted that if desired a slight modification of the basic invention may be made by cutting off the tip of the upstanding portion 42 along the dotted line extending from the five units mark on the inner edge and outer edge squares. It should be clear that modifications may be resorted to in the scales without departing from the basic invention.

In the use and operation of the invention for drawing a line at an angle to the horizontal, the use of the lower edge l3 of the base portion H as a base edge will be first discussed. With the lower edge l3 forming the horizontal, the inner edge IE will be at degrees to the horizontal, the outer edge It will be at 60 degrees to the horizontal, and'the lower edge II will be at 135 degrees to the horizontal. It is to be noted that angles of 45 degrees and degrees may be drawn by turning the implement with the scale face down using the same base edge It.

By using the lower edge I! as the horizontal, the upper and lower edges is and E3 of the base portion l I will be at 45 degrees to the horizontal, the inner edge IE will be at degrees to the horizontal and the outer edge It will be 105 degrees to the horizontal. An angle of '75 degrees may be made by turning the implement face down using the lower edge II as the base and outer edge I6 as the drawing edge.

By using the outer edge 16 as the horizontal, the upper and lower edges i i and E3 of the base portion I I will be at 120 degrees to the horizontal, the inner edge is will be at 30 degrees to the horizontal and the lower edge 57 will be at 75 degrees to the horizontal. By reversing the implement with the face down using outer edge It as the base angles of 60 degrees, 105 degrees and degrees may be formed. As indicated above, the following angles may be direct- 1y drawn by using a combination of one base edge and one drawing edge: degrees, degrees, degrees, degrees, degrees, degrees, degrees, degrees and degrees, or, in other words, any angle possible through the normal use of the 306090 triangle and the 45 triangle or any combination thereof.

The protractor is used in the following manner: to measure an angle formed by two lines, the upper edge 14 of the base portion 11 is laid along one of the lines with the apex of the two lines falling at the point marked with an arrow and C the angle between the lines may then be read directly from the point of crossing of the second line with the protractor scale.-

In drawing a line at a, specifieangle-to the horizontal, the protractor scale and the point marked with an arrow and C are lined up on the angle desired with a horizontal base line, the upper or lower edges 14 or 13 may then be used to directly draw the angle desired.

Having thus described my invention in detail, my invention is delineated by the following claims. f

I claim:

1. A drafting implement, involving: a flat member of generally L form having three external edges, there being a first and a second external edge at 60 internal angle to each other and a third intervening edge at 45 external angle to said first edge and 75 external angle to said second edge, there also being two perpendicularly related internal edges, one thereof being parallel to said first edge and the other converging at 30 included angle relative to said second edge.

member 01' generally L form having a parallel edge leg and a converging edge leg, the internal edges of said legs being mutually perpendicular and the external edges being acutely related, the apex of said external edges being truncated to form a third external edge, whereby any of said external edges may be placed against a straight edge to dispose said internal edges in any of three different angular positions, said converging edge leg defining a 39 included angle, and said third external edge being disposed at 45 external angle to one of said external edges and 75 external angle to the other of said external edges whereby a line drawn normal to at least two of said external edges may pass through the point of intersection of said internal edges.

EDGAR E. KELLEMS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 874,383 Bishop Dec. 2 1, 1907 1,068,124 Hall July 22, 1913 1,255,429 Killion Feb. 5, 1918 1,523,919 Vitek et a1 Jan. 20, 1925 1,816,548 Bobidou July 28, 1931 2,011,282 Hockman Aug. 13, 1935 2,149,422 Coffey Mar. '7, 1939 FOREIGN PATENTS Number Country Date 59,687 Switzerland Jan. 18, 1912 386,883 Great Britain Jan. 26, 1933 OTHER REFERENCES Publ., McQuaid, Air-Vu System of Drawing, 1945, pages 20 and 32. (Copy in Div. 66.)

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