Richard J Gregory

US Patent:

52014096, Apr 13, 1993

Filed:

Sep 4, 1990

Appl. No.:

7/577454

Inventors:

Adolf Martin - Glenview IL
Richard A. Gregory - Chicago IL

Assignee:

Inventio AG - Hergiswil

International Classification:

H01H 1370
H01H 902

US Classification:

200345

Abstract:

A vandal resistant push button assembly has a guide ring attached to a mounting plate spaced from a face plate such as an indicating and announcing device or a modular wall assembly of an elevator car. The guide ring has a first shoulder which cooperates with a snap ring engaging a first annular groove formed in the guide ring for retaining the ring in an opening formed in the mounting plate. There is play between the periphery of the opening in the mounting plate and the outer diameter of the guide ring such that the guide ring can be aligned with respect to an opening in the face plate and the snap will cover the gap defined by the play. A push button slidably extends through the guide rings on first and second guide surfaces to actuate a switch and a second shoulder formed on the push button engages a stop surface on the guide ring to prevent further travel in the actuation direction. Spring forces originating from the switch press the push button forward to a rest position at which a spring clip engaging a second groove formed in the push button abuts an end of the guide ring. In this position, a seamless spherical surface is formed by the push button and the guide ring at the face plate.