COMPASSES

• US 3,781,995 A
• Filed: 03/22/1972
• Issued: 01/01/1974
• Est. Priority Date: 09/22/1970
• Status: Expired due to Term

• Current Assignee: Pierre Debeaux
• Original Assignee: Pierre Debeaux
• Inventors: Debeaux, Pierre
• Primary Examiner(s): Haroian, Harry N.
• Application Number:
  US05/236,906
• Time in Patent Office: 650 Days
• Field of Search: 33/27F
• US Class Current: 33/27.06
• CPC Class Codes: B43L 9/00 Circular curve-drawing or like instruments curve rulers or templets B43L13/00

Abstract

Improved compasses consisting of two arms adapted to be locked in adjustable angular positions and of a scriber arranged at the intersection of the useful edges of these arms; a circle is drawn by placing the compasses on the sheet and causing it to slide in such a manner that the straight edges of the arms pass at all times through two fixed points.

Claims

1. Compasses for drawing arcs comprising:

two movable arms hinged at one point to each other;

means for locking said arms to each other;

each said arm including a substantially flat ruler having a straight edge extending over a given length;

the straight edges of said rulers defining straight lines extending to an imaginary point of intersection;

said rulers having overlapping parts;

means for holding a scriber means;

a guide strip disposed at the hinge point of said arms for positioning said scriber means;

said means for holding the scriber means being located at one end of the guide strip;

said guide strip being retained and guided by at least one guide pin accommodated in a slot in said guide strip and being connected to the rulers whereby said guide strip passes vertically above the hinge point of said rulers;

said guide strip being further retained and guided by a stud integral with said guide strip and running in two intersecting slots which follow a curve in tHe form of a conchoid, said slots being arranged in said overlapping parts of the rulers, the straight line considered by the conchoid being the straight line of each ruler, whereas the fixed point of the conchoid merges with the hinge point of the rulers, said means for holding the scriber means being attached to the guide strip in such a manner that the scriber means is located on the imaginary point of intersection of said straight lines.

2. Compasses according to claim 1, wherein the overlapping part of each ruler, has an indentation at the end of the straight edge with which said ruler is provided.

3. Compasses according to claim 1, wherein the axis of the guide strip is the axis about which the rulers are hinged.

4. Compasses according to claim 1, wherein the guide pin of the guide strip is carried on two arms, one end of each arm being hinged about said pin, the other end of each arm being hinged to one of the rulers.

5. Compasses according to claim 1, wherein the guide strip has two guide pins running in two slots therein, one being the axis about which the rulers are hinged, and the other being a pin carried on two arms, one end of each arm being hinged about said pin, and the other end of each arm being hinged to one of the rulers.