Proximity switch operable without physical contact

• US 4,420,651 A
• Filed: 08/18/1981
• Issued: 12/13/1983
• Est. Priority Date: 09/08/1980
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Teich, Dieter
• Primary Examiner(s): Grimley, A. T.
• Assistant Examiner(s): Tone, D. A.
• Application Number:
  US06/294,035
• Time in Patent Office: 847 Days
• Field of Search: 174/50, 174/52 R, 328/5, 340/693, 361/179, 361/180, 361/181, 200/303, 73/431, 403/340, 403/4, 46/25, 46/28
• US Class Current: 174/50
• CPC Class Codes: H03K 17/945 Proximity switches H03K17/96 takes precedence

Abstract

A proximity switch, operable without physical contact and having an elongated columnar housing which has, perpendicular to its principal axis, a cross-sectional shape with two orthogonal axes of symmetry. The housing is divided into at least two parts and the parts are joined at three abutting surfaces. One of the abutting surfaces extends in the plane of the principal axis and the others intersect the first surface, extending at angles of 90° thereto. The greatest length of the first abutting surface, measured in the direction of the principal axis, is the same as the distance between the principal axis and the outer surface of the housing. With this arrangement, it is possible to arrange the sensor head carrying the sensor operating surface so that the operating surface lies on the longitudinal axis or at 90° to the longitudinal axis in such a manner that the sensor surface does not extend beyond a generatrix of the outer surface.

Claims

1. In a proximity switch which can be operated without physical contact and which comprises an elongate, columnar housing having at least one lateral wall lying parallel to and spaced a predetermined distance from the principal axis of the housing, the housing being symmetrical about two orthogonal axes of symmetry which are perpendicular to the principal axis, and the housing having at least two parts which are joined at abutting surfaces which intersect the principal axis at an angle, the improvement in which:

the abutting surfaces joining the parts each comprise first, second and third abutting surfaces, the first surface being parallel to the principal axis, and the second and third surfaces each intersecting the first surface at an angle of 90°

, the greatest dimension of the first abutting surface, measured in the direction of the principal axis, being equal to the shortest distance from the principal axis to the lateral wall;

the housing is circular in cross section; and

the first abutting surface is joined to the second abutting surface along a straight line and to the third abutting surface along a semicircle, the area of the first surface being equal to half the cross-sectional area of the housing.

2. In a proximity switch in accordance with claim 1, the further improvement in which:

the housing comprises first, second, and third parts and the first and second parts and the second and third parts are each joined by three abutting surfaces.