The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 19, 1991
Filed:
Jul. 31, 1990
Jon P Zoller, Prior Lake, MN (US);
Jeffrey J Norris, Bloomington, MN (US);
ITT Corporation, New York, NY (US);
Abstract
A switch assembly is provided with a short travel switch (16, FIG. 3) activated by a push button that has a long travel both before and after closing of the short travel switch, and which provides a substantially constant spring rate throughout push button travel, with minimal noticeable disruptions. The switch assembly includes an inner plunger (32) which depresses the short travel switch, and an outer plunger (44) or keystem coupled to the push button. An inner spring device (46) couples the inner plunger to the housing, and an outer spring device (52) couples the two plungers, so the springs act in series. The preloads of the two spring devices are substantially the same, and the inner spring has a lower spring rate than the outer spring. As the keystem is depressed, both springs begin to compress until the inner plunger contacts the short travel switch. Continued depression of the push button and keystem results in compression of only the outer spring, there being a smooth transition because the preload of the outer spring has already been exceeded. The mechanism lies in a passage of a housing, the housing including a bar (102, FIG. 5) that extends across the passage, with the keystem having grooves that receive the bar end portions. Pin sockets (116) are mounted on the middle of the bar to receive lamp terminals, and a pair of conductors (142) have flattened ends (144) receiving the pin sockets.