US1007937A

US1007937A - Mathematical instrument.

Info

Publication number: US1007937A
Application number: US641045A
Authority: US
Inventors: Albert Garinger
Original assignee: Individual
Current assignee: Individual
Priority date: 1911-04-01
Filing date: 1911-07-28
Publication date: 1911-11-07
Anticipated expiration: 1928-11-07

Description

A. GARINGER.

MATHEMATICAL INSTRUMENT.

APPLICATION TILED JULY 28, 1911.

Patented Nov. 7, 1911.

COLUMBIA PLANOGRAPH co.,wASHINGTON. 11.5.

ALBERT GARINGER, OF STAMFORD, CONNECTICUT.

MATHEMATICAL INSTRUMENT.

Original application filed April 1, 1911, Serial No. 618,381.

Specification of Letters Patent.

Patented Nov. '7, 1911.

Divided and this application filed July 28, 1911.

Serial No. 641,045.

T 0 all whom it may concern:

Be it known that I, ALBERT GARINGER, a citizen of the United States, and a resident of the city of Stamford, in the State of Connecticut, have invented certain new and useful Improvements in Mathematical Instruments, of which the following is a specification.

My invention relates to devices for drawing curves, and particularly curves of the type known as conchoid curves.

In the accompanying drawings, Figure 1 is a plan view of an instrument constructed according to my invention; Fig. 2 is a vertical section of the same, taken on the line 2-2 of Fig. l; and Figs. 3 and 4 are detail views, being vertical sections taken on the lines 33 and 44 of Fig. 1 respectively.

The invention herein described and shown in the accompanying drawings, is a modification of an invention described and shown in an accompanying application made by me and filed in the United States Patent Office on April 1, 1911, bearing the Serial No. 618,381, this application being a division of the said accompanying application. In carrying this form of my invention into effect I provide three members of suitable size, designated respectively 10, 11 and 14. The members 10 and 11 are pivotally connected together by a set-screw 15, the same, and the manner in which it connects the said members being shown more in detail in the sectional view Fig. 3. This construction is such that by tightening the set screw 15 the members 10 and 11 may be firmly set or fixed at any determined angular relation to each other. The member 10 is formed into such a shape that one of its edges-the upper edge in Fig. 1-constitutes an extension of the center line of the pivot 15, and this upper edge corresponds to the directrix of the conchoid curve to be traced. The members 11 and 14 are pivotally connected to gether by the pivot 17, so that the member 14 is always free to swing angularly with relation to the member 11. This pivot 17 corresponds to the focus of the curve. The member 14 is provided for approximately the outer half of its length with a slot having walls which slope downward and in ward, and in this slot slides an extension arm 12, the sides of which slope in a corresponding manner so as to engage with the sloping walls of the slot. This construction is best shown in the transverse section Fig. 4. The inner end of the extension or sliding member 12 is provided with a downwardly projecting heel 18, the inner end of which is wedge shaped and provided with a knife-edge, as shown at 16 in Fig. 1. This knife-edge 16 bears against the directrixedge of the arm 10. The outer end of the extension or sliding member 12 is provided with a perforation 18 into which may be inserted a pencil or other tracing point for the purpose of placing upon paper the conchoid curve to be drawn.

The operation of my invention is as follows: The member 11 having been firmly fixed in any desired relation to the member 10 by means of the set-screw 15, a pencil or tracing point is placed in the perforation 18 of the sliding or extension member 12. The said extension member 12 and the member 14 are then swung around upon the pivot 17, the knife-edge extremity of said member 12 being always kept in contact with the directrix-edge of the member 10. Upon performing this operation the tracing point carried by the free end of the member 12 will trace a conchoid curve, of which the pivot 17 represents the focus, and the upper edge of the member 10, with which the knife-edge 16 is in contact, represents the directrix.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is as follows:

1. An instrument for tracing conchoid curves, comprising a stationary member an edge of which corresponds to the directrix of the curve, a member pivotally connected to said first named member and adapted to be firmly set at a determined angle with regard to said first named member, and a swinging member pivotally connected to said second member at a point corresponding to the focus of the curve and provided with an extension member the inner end of which bears against the directrix edge of the first member.

2. An instrument for tracing conchoid curves, comprising a stationary member an edge of which corresponds to the directrix of the curve, a member pivotally connected to said first named member and adapted to be firmly set at a determined angle with regard to said first named member, and a swinging member pivotally connected to said second member at a point corresponding to the focus of the curve and provided my hand in the presence of two Witnesses, 10 with an extension member the inner end of h this 22d day of July, 1911.

whic is provided with a narrowed or wedgeshaped extremity which bears against the ALBERT GARINGER' direotriX edge of the first named member WVitnesses:

and the outer end of which is adapted to LILIAN M. WARNER, bear tracing or drawing means. HENRY SILVERMAN.

In witness whereof, I have hereunto set Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of IPatents, Washington, D. G.