US101477A - Improvement in combined square, protractor, level - Google Patents

Description

J. A. LITTLEFIELD.

Bevel. No. 101,477. Patented April 5,1870:

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UNITED STATES PATENT OFFICE.

J. A. LITTLEFIELD, OF RANDOLPH, MASSACHUSETTS.

IMPROVEMENT IN COMBINED SQUARE, PROTRACTOR, LEVEL, 840.

Specification forming part of Letters Patent No. 101,477, dated April 5, 1870.

To all whom, it may concern Be it known that I, J. A. LITTLEFIELD, of Randolph, in the county of Norfolk and State of Massachusetts, have invented a new and useful Improvement in Combined Square, Plumb, Level, Protractor, and Rule; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

, This invention relates to a compound tool adapted more particularly to the machinists use in planing and finishing nuts, 82c. and it consists in an improved article of manufacture not hitherto known to the public, and by which time may be saved and convenience attained.

In the accompanying drawings, Figure 1 represents a side view showing the combination entire (with the exception of a level) and the manner in which the bevel is formed. Fig. 2 is a section looking from the line as w of Fig. 1.

Similar letters of reference indicate corresponding parts.

A is the stock, and B the tongue, of a trysquare.

0 represents the ordinary spirit reservoir or tube in the stock A, by which the stock is converted into a spirit-level. When the tongue B stands at a right angle with the level or stock, as seen in the drawings, it forms a plumb. The manner of attaching the tongue to the stock is represented in the drawings in dotted line. Through the ear which projects from the tongue the screw D passes, by which the tongue is fastened in any desired position or at any angle. Thus any bevel or angle varying from a right angle is readily obtained.

E is the protractor, consisting of an index finger or pointer, F, attached to the stock, and of a series of lines and figures indicating degrees, inclosed between two arcs of circles on the tongue, the center of which circles is the center of the screw or motion of the tongue,

both higher and lower degrees than are found within the circles. These degrees or angles are indicated by the face and back of the stock A, when the tongue is turned so that the finger F leaves the inner circle. This arrangement is of great advantage where lines of definite angle are to be drawn. The manner in which the tongue is attached to the stock allows the pointer F to sweep over a greater circle, which will be found suflicient for most purposes. The tongue B is graduated or marked off into inches and fractions of inches, which renders the article very convenient for measuring or spacing off distances. The combination does not necessarily interfere with the use of the article as a try-square. When the tongue is adjusted to any angle, it is securely fastened by the screw and remains immovable until again adjusted. It will thus be seen that we have in this simple article a trysquare, plumb,vlever, rule, and protractor combined, thus dispensing with the use of a varietyof separate and expensive tools or instruments.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- As an improved article of manufacture, a compound tool consisting of the stock A,tongue B, tube 0, screw D, and protractor E F, all connected, adjusted, and applied in the manner described.

The above specification of my invention

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