US434073A - Plotter - Google Patents

Description

(No Model.)

. L. I'. RONDINELLA.

PLOTTER.-

No. 434,073. Patented Aug. 12, 1890.

UNITED STATES PATENT OFFICE.

LINO F. RONDINELLA, OF PHILADELPHIA, PENNSYLVANIA.

PLOTTER.

SPECIFICATION forming part of Letters Patent No. 434,073, dated August 12, 1890.

Application tiled April 24, 1890.

To all whom it may concern.:

Be it known that I, LINo F. RONDINELLA, a citizen of the United States, and a resident of the city and county of Philadelphia, and State of Pennsylvania, have invented a new and useful Improvement in Drawing-Instruments, of which the following is a true and exact description, due reference being had to the accompanying drawings, which form a part of this application, and in which similar letters denote simi-lar parts.

My invention relates to that class ot' drawing-instruments which are used in connection with the T-square or straight-edge in meehanical drawing` for the purpose of plotting and measuring angles.

The object of my invention is the production of a single instrument, which, when used in connection with the ordinary T-square or straight-edge, will enable a draftsman to plot and measure any or all angles that are multiples of the angles of thirty and forty-five degrees. In the triangles which are now generally used for this purpose it is necessary, in order to obtain all the angles which are multiples of thirty and forty-tive degrees, that two dierent instruments shall be used, which is a source of annoyance and expense; and my invention is very advantageous in that all angles multiples of thirty or forty-tive degrees can be plotted without working in shadowthat is, when the draftsman faces the light (which is .the ordinary method) any angle a multiple of thirty or forty-tive degrees can be plotted without having the edge along which the line is drawn facing the draftsman.

My invention consists of a plain quadrilateral piece of wood or other suitable Inaterial, the sides of which are at. such angles with each other that whrn used with the T-soluare or straight-edge the draftsman can readily lay out or measure any angle which is a multiple of thirty or of forty-five degrees.

In the drawings, Figures l, 2, and 3 repre- Serial No. 349,226. (No model.)

sent my improved drawing-instrument placed in connection with a straight-edge, the position of the instrument with regard to the straight-edge being varied in the three figures.

E F, F G, G H, and H E represent the four sides of my improved drawing-instrument, the sides H E and E F forming a right angle or an angle of ninety degrees, the sides E F and F G forming an angle of forty-five degrees, the sides F G and G H forming an angle of one hundred and sixty-five degrees, and the sides G H and H E forming an angle of sixty degrees.

S represents a portion of an ordinary T- square or straight-edge. As shown in Figs.

1, 2, and 3, and as is self-evident, the line H E ih Fig. l, the line F G in Fig. 2, and the line G H in Fig. 3, are common to both the drawing-instrument and the straight-edge. As may be readily seen, by varying the position of the various sides with reference to the straightedge, any angle which is 'a multiple of thirty or of forty-five degrees can be easily drawn, or if drawn can be easilymeasured.

Having now fully described my invention,

what I claimand desire to p rotect by Letters Patent, is-

An improved drawing-instrument for plotting and measuring angles, which consists of a plain quadrilateral piece of wood or other suitable material, the sides of which form the angles of ninety degrees, forty-live degrees, one hundred and sixty-tive degrees, and sixty degrees, respectively, the angles of forty-five degrees and sixty degrees being adjacent to the right angle, While the angle of one huudred and sixty-five degrees is opposite to the right angle.

In testimony of which invention I have hereunto set my hand,at Philadelphia, Pennsylvania, this 23d day of April, 1889.

LINO F. RONDINELLA.

Witnesses:

A. B. ENTWIsTLE, WM. F. GRAY.

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