US2499721A - Protractor attachment for - Google Patents

Description

March 7, 1950 I M. L. cAssrrY PROTRACTOR ATTACHMENT FOR CARPENTER'S SQUARES Melvin L. Cassz'ij 2mm WWW 6,

Filed March 22, 1946 Patented Mar. 7, 1950 PEOTRACTOR ATTACHMENT FOR CARPENTERS SQUARES Melvin L. Cassity, Belton, S. 0.

Application March 22, 1946, Serial No. 656,193

2 Claims.

The primary object of the invention, of which. i

the accompanying drawings are illustrative, is the provision of means whereby the bevel cuts, pitch, lengths, etc., of building timbers may be quickly and accurately determined and laid ofi, said means being an attachment for the common carpenters square, which when set for a specific job will provide a marker for both ends of a timber and for intermediate cuts thereof.

Another object of the invention is to provide a protractor attachment for a carpenters square.

A still further object of the invention is the provision of means whereby certain length cuts, etc., may be automatically determined.

Other features and advantages will become more readily apparent from the following description and the accompanying illustrative drawings in which:

Figure 1 is a plan view of the invention,

Figure 2 is a sectional view on line 2-2 thereof,

Figure 3 is a similar view taken on line 33 of Figure 1,

Figure 4 is a sectional view on line 4-4 of Figure 1, and

Figure 5 is a perspective View of a protractor pointer member.

While one embodiment of the invention is illustrated in the above referred to drawings, it is to be understood that they are merely for the purpose of illustration and that various changes in construction may be resorted to in the course of manufacture in order that the invention may be utilized to the best advantage according to circumstances which may arise without in any way departing from the spirit and intention of the device which is to be limited only in accordance with the appended claims. And while there is stated the primary field of utiity of the invention it remains obvious that it may be employed in any other capacity wherein it may be found applicable.

In the accompanying drawings, and in the following specification, the same reference characters are used to designate the same parts and elements throughout and in which It] refers to the invention in its entirety and N indicates a carpenters square on which the protractor attachment is mounted.

The said protractor consists of a longitudinal base l3 and a conforming plate |4 held separated by end spacer blocks l5 and Hi, said members being permanently fixed together by screws l1 and I8. The said spacers are of substantially the same thickness as the blades l9 and 2|] of the carpenter's square ll, whereby the said last 1 adjusted position.

blades may be easily slidable within the space 2| between said members l3 and M.

The protractor plate I4 is provided with a longitudinal slot 22 extending from beyond zero 24 to adjacent the end 29 of the device.

The base I3 is provided with a longitudinal slot 30 within which is slidably mounted the square head 3| of a bolt 32 the threaded end 33 Of which projects through slot 22 of plate l4 and has a wing nut 34 thereon whereby said plate and base may be drawn into clamping engagement with the square blade [9, said members l3 and I4 being suificiently flexible for this purpose.

The spacer block I6 is of elongated triangular form, its beveled side 35 being within the space 2| in order to provide for free adjustment of blade 20 within said space. The side 21 of plate I4 is graduated as at 36 and pointed off in twelfths as at 31 conforming to the graduations 38 and 39 of the square whereby the members co-act to determine and indicate certain required dimensions, bevels and angles.

The protractor per seAfl is automatic in operation and it consists of a base 4| provided with a relatively long straight edge 42 which seats against the inner straight edge 43 of the blade 2|] of square The inner end 44 of member 4| is provided with an integral semi-circular extension 45 scaled in degrees of a circle as at 46. Connected to the center of member 45 is an upright bolt 41 which projects through the head 48 of an inverted U-shaped slide 49, the terminals 50 of the arms 5| and 52 of which seat upon the sides 21 and 28 of plate I 4, straddling the slot 22, said arms however are provided with intermediate extensions or tongues 54 and 55 which project into the slot 22 holding the member 49 in place. A wing nut 56 is threaded upon the projecting end 51 of the bolt 4'1, whereby the member 49 may be clamped against movement.

Also mounted upon the bolt 49 is a smaller like member or alidade member 58, the arms 59 and 60 of which are provided with depending tongues BI and 52 which also seat in the slot 22. Projecting from the forward edge 63 of the head 64 of member 58 and from the center thereof is an alidade 65, the post 66 of which turns down to the scale 46. Said head 64 is also provided with a bore 61 through which the bolt 41 extends and threaded upon the inner portion 68 of the bolt isa wing nut 69 adapted to be screwed down upon the member-15,8, whereby it may be securediin One mpl'e of the use of a device ls'a's'" follows: In cutting rafters,for inthe above deseribed stance, set the square to the pitch desired, the slide protractor member 4| against the long blade 20 of the square and look by screwing down wing nut 56. Now slide the square out to one half the width of the building indicated by inches and feet, in scale 38 as 19 feet, 9 inches in Figure 1, that is, the reading indicated on scale 38 by the edge of the plate 14. With the square in this position slide bolt 32 to near blade and tighten the nut 24 which will hold the members securely connected and the reading indicated on the scale 36 on the member M by the intersecting outer edge of the blade 19 is the length of the rafter. This device has many uses by which the work of carpenters, architects, etc., may be greatly shortened as with it all lengths, bevels, pitches, stair stringers, risers, etc., may be quickly laid and it will show the diagonal length .of squares and rectangles.

From the foregoing specification it will become y apparent that the invention disclosed will adequately accomplish the functions for which it has been designed and in an economical manner and that its simplicity, accuracy and ease of operation are such as to provide a relatively inexpensive device considering what it will accomplish and that it will find an important place in the art to which it appertains when once placed on the market.

It is thought that persons skilled in the art to which the invention relates will be able to obtain a clear understanding of the invention after con sidering the description in connection with the drawings. Therefore, a more lengthy description is regarded as unnecessary.

Changes in shape, size and rearrangement of details and parts such as come within the pur- View of the invention claimed may be resorted to, in actual practice, if desired.

Having now described'the invention, that which is claimed to be new and desired to be procured by Letters Patent is:

1. A tool for carpenters including an elongated scale comprised of a pair of spaced parallel .similarly shaped slightly flexible straps having spacers secured to and between terminal portions of the strap, slots extending longitudinally of said straps, a square having both arms thereof slidably mounted in the scale between said straps, a protractor having mounting means for adjustably securing said protractor on the scale, said means comprising an inverted U-shaped member having tongues extending into said slot in one strap, a pointer integral with the U-shaped member and indicating the angular disposition of the protractor on the scale, a threaded bolt terminally secured to the protractor and extending through the slot in one strap and through the U-shaped member, a wing nut for adjustably securing the protractor to the said U-shaped member against relative rotation, said protractor having a straight edged portion for frictional engagement with one arm of the square, a larger U-shaped member secured on said bolt by another wing nut, said larger U-shaped member engaging the outside or one strap and having tongues slidably engaged in said slot in one strap, whereby the protractor is adjustably secured against movement longitudinally of said scale.

2. A tool for carpenters according to claim 1 and including a clamping bolt inserted through both said slots at one side of the other arm of said square, whereby the square can be adjustably secured in place.

MELVIN L. CASSITY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS .Number Name Date 450,823 Fuller Apr. 21, 1891 666,346 Goelzer Jan. 22, 1901 792,212 Heddle June 13, 1905 1,139,648 Demmer May 18, 1915 1,346,409 Lucas July 13, 1920 1,894,886 Pashowski Jan. 1'], 1933

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