US1021692A - Drawing instrument. - Google Patents

Description

T. H. MGANELLY.

DRAWING INSTRUMENT.

APPLICATION FILED MAY 8, 1911.

Patented Mar. 26, 1912. 4

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DRAWING INSTRUMENT. APPLICATION FILED MAY 8, 1911.

1,021,692. Patented Mar. 26, 1912.

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THOMAS HOMER MQANELLY, OF FINDLAY, OEHIQ.

DRAWING INSTRUMENT.

Specification of Letters Patent. Patented lIar. 26, 1912.

Application filed May 8, 1911. Serial No. 625,803.

To all whom it may concern:

Be it known that I, THOMAS H. Mc- ANELLY, a citizen of the United States, and a resident of Findlay, in the county of Hancock and State of Ohio, have invented a new and Improved Drawing Instrument, of

which the following is a full, clear, and exact description.

The object of the invention is to provide a new and improved drawing instrument, combining a protractor, compass and measuring stick or straight edge for the use of mechanics, instructors and other persons, and especially serviceable for use in schools when making drawings in geometry, physics and the like on a blackboard, the drawing instrument being simple, durable in construction and capable of being readily folded into small space or extendedfor drawing straight lines, angles, circles, etc.

For the purpose mentioned, use is made of a straight edge made in foldable sections, of which one is mounted to swing laterally and provided with an adjustable pencil holder for receiving a pencil for drawing circular lines.

A practical embodiment of the invention is represented in the accompanying drawing forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a perspective view of the drawing instrument showing the sections extended to form a straight edge; Fig.2 is a like view of the same with the parts in folded position; Fig. 3 is. a plan view of the first section; Fig. 4 is a similar view of par-t'of the middle section; Fig. 5 is an enlarged cross section of the joint between the first and middle sections on the line 55 of Fig. 2; Fig. 6 is a similar view of the pivotal connection between the middle and end sections, the section being on the line 66 of Fig. 1; Fig. 7 is an enlarged perspective view of the pencil holder; Fig. 8 is a plan view of the drawing instrument, showing the parts .in position for drawing circles; Fig. 9 is a like view of the drawing instrument showing the parts in position for indicating an angle; Fig; 10 is a plan view of a modified form of the drawing instrument; and Fig. 11 is a face view of another modified form of the drawing instrument.

The drawing instrument consists essentially of a straight edge or measuring stick formed of a number of sections A, B and C,

of which the sections A and B are connected with each other by a transversely-extending pivot or a hinge D, to permit of folding the section A onto the section B as plainly indicated in Fig. 2. The sections B and C are pivotally connected with each other by a vertical pivot E, to permit of swinging the section C laterally into an extended position, as shown in Fig. 1, or onto the face of the section B, as shown in Fig. 2, or into an angular position, as indicated in Figs. 8 and 9. The middle section B is sufficiently long to accommodate both end sections A and C- when the latter are folded upon the middle section B, as shown in Fig. 2, and the sectionsA, B and C are provided on both faces with graduations F representing linear measurement, preferably inches, and subdivisions, on one face, and metric measure ment on the other face.

On the outer section C is mounted to slide lengthwise a pencil holder G,'provided at itsinner end with a bearing G fitting on the section C, so as to guide the holder G in its lengthwise movement, and the outer end of the holder G is provided with an eye or ring G for the insertion of a pencil or other marking tool, to permit of drawing circles on swinging the end section G laterally relative to the section B, the pivot E being the center of the circle, as will be readily understood by reference to Fig. 8. An eye or ring G is attached to the bearing G and projects laterally therefrom, so as to permit the insertion of a pencil or other marking tool into the eye or ring G for drawing circles of a smaller radius, as indicated in Fig. 8.

Alongone edge of the holder G are formed teeth or notches Gr adapted to en gage a bearing H held on the outer end of the section C, and each of the said teeth or notches G is about of a length corresponding to one-quarter of an inchin conformity with the graduations F on the section G, and the said teeth are adapted to be hooked into the bearing H under which passes the holder G and secured to the outer end of the section C. When the holder G is in its innermost position, as indicated in Fig. 1, the eye G projects beyond the outer terminal of the section C and thus forms a finger piece adapted to be taken hold of by the operator for slightly moving the holder Gr laterally to disengage the corresponding tooth Gr from the bearing H, and to allow of pulling the holder G outward or inward according to the length of the radius of the circle to be drawn, by inserting the marking tool in the eye G The eye G is preferably pivoted on the bearing G to ermit of swinging the same onto the face of the holder when folding the drawing instrument.

In order to indicate the degrees of an angle represented by the sections B and C (see Fig. 10), use is made of a segmental arm I provided with a degree scale and pivoted on the section B. The segmental arm I is adapted to engage an open bearing J attached to the section C, so that the segmental arm I indicates the degree of the angle formed by the sections B and C when swung into an angular position one relative to the other, as shown in Fig. 10.

As shown in Fig. 11, the sections C pivoted by the pivot E to the middle section B is provided with a cutout portion filled by the pencil holder G provided at its inner end with a bearing K, slidingly engaging the section C The outward portion of the pencil holder G longitudinally engages a bearing K attached to the section C The pencil holder G is provided at its outer end with the eye G for engagement by the marking tool the same as the eye G previously mentioned.

The drawing instrument shown and described is very simple and durable in construction, composed of comparatively few parts, not liable to get out of order easily.

It is understood that the device is very serviceable for use on blackboards in schools, to permit of the instructor or scholar to readily draw geometrical or other figures on the blackboard by the use of chalk or other tools inserted in the eyes G G or G Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A drawing instrument, comprising a straight edge having a central section, and end sections, one of said end sections being hinged to one end of the central section to fold thereon, the other end section being pivoted to the opposite end of the central section in superposed relation, said central section being of a length at least that of the combined lengths of the end sections, whereby the free ends of the latter may be adjacent one another when both are moved to a folded position on the central section, and

a pencil holder slidably mounted on the swinging section and having an extending free end adapted to overlap a portion of the free end of the hinged end section in the folded position.

2. A drawing instrument comprising a straight edge having a central section, and end sections, all having graduations along at least one edge, one of said end sections being hinged to one end of the central section to fold thereon, the other end section being pivoted to the opposite end of the central section in superposed relation, said central section being of a length at least that of the combined lengths of the end sections, whereby the free ends of the latter may be adjacent one another when both are moved to a folded position on the central section, and a pencil holder slidably mounted on the swinging section and having an extending ring, for the insertion of a pencil, adapted to overlap a portion of the free end of the hinged end section in the folded position.

3. A drawing instrument, comprising a straight edge made in sections, one end section having a pivotal connection with the adjacent section to permit of swinging the end section laterally, the sections having graduations representing linear measurement, and a pencil holder mounted to slide on the end section and having teeth along one edge spaced apart according to the divisions of the said graduations, the said pencil holder being provided at the outer end with an integral ring, and near the inner end with a pivoted ring, the said rings being for the insertion of a pencil for drawing circular lines of different radii.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOMAS HOMER McANELLY.

Witnesses:

O. S. HARTMAN, W. P. ALsPAoI-I.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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