Device for drawing ellipses

US4567662A · kind A · utility

Inventor

• Peter Wallner · Kriens, CH

Key dates

• Filing date: Jul 5, 1984
• Grant date: Feb 4, 1986
• Expiry date: Jul 5, 2004

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B43L11/041
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

A compass type instrument capable of describing curves, circles and ellipses of infinitely variable angle and size. The central column of the instrument is supported on a foot that aligns the instrument with the center of the desired ellipse and maintains the instrument still and perpendicular to the surface to be marked. Removably mounted on the central column is a circular cam that is hinged symmetrically along it's diameter. Non-circular symmetrically hinged shapes may be substituted to alter the curve. The extent that this cam is folded about itself is adjustable and determines the angle of the ellipse described. An articulated follower arm is adjustably mounted to the top of the central column. About the central column rotates the upper section of the follower arm that pivots at a point variable from the center of the column. The upper follower arm is spring loaded in order to keep contact with the cam. The upper follower arm may be curved or angled outward from the central column at the area of contact with the cam to further vary the shape described. From the upper section of the follower extends an arm that lies parallel to the surface to be marked. To this lower extending …