Temperature responsive snap acting control assembly, device using such assembly and method for making

• US 6,412,165 B1
• Filed: 04/23/1998
• Issued: 07/02/2002
• Est. Priority Date: 08/28/1997
• Status: Expired due to Fees

• Current Assignee: Sensata Technologies Massachusetts Incorporated (Sensata Technologies Holding Plc)
• Original Assignee: Texas Instruments, Inc.
• Inventors: White, Sheldon S.
• Primary Examiner(s): Vo, Peter
• Assistant Examiner(s): TUGBANG, ANTHONY D
• Application Number:
  US09/064,962
• Time in Patent Office: 1,531 Days
• Field of Search: 296/22, 296/23, 297/56, 267/159, 267/160, 267/161, 267/162, 200/283, 200/459, 200/467, 337/379, 337/343, 337/111, 337/298, 228/179.1, 228/180.1
• US Class Current: 29/622
• CPC Class Codes: H01H 11/00 Apparatus or processes specially adapted for the manufacture of electric switches processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards, H01H13/88
• CPC Class Codes: H01H 37/5418 using cantilevered bimetallic snap elements
• CPC Class Codes: H01H 37/5427 encapsulated in sealed miniaturised housing
• CPC Class Codes: Y10T 29/49105 Switch making
• CPC Class Codes: Y10T 29/49107 Fuse making

Abstract

A method of increasing the cycle life of a thermostatic disc element for use in a disc assembly used in thermostatic switches in which a weld slug is used to weld the disc element to the disc assembly thereby causing a heat affected zone of the disc element comprising the step of engaging the surface of the disc element opposite the surface adjacent the weld slug with a fulcrum member at a location spaced from the heat affected zone so that upon reversal of the curvature of the disc element, the disc element will bend about the fulcrum member at a location removed from the heat affected zone.

Claims

1. In a snap acting thermostatic disc assembly including a thermostatic disc element with opposite first and second face surfaces with a weld slug placed on a portion of said first face surface of said thermostatic disc element which is welded to the disc element causing a heat affected zone of the thermostatic disc element, the thermostatic disc assembly in turn being attachable to a support for mounting in a device, the thermostatic disc element having a first concave curved configuration relative to a selected direction and a second reversed convex curved configuration relative to the selected direction in dependence upon the temperature of the thermostatic member, a method of increasing the cycle life of the thermostatic element comprising the step of engaging the second face surface of the disc element with a fulcrum member at a location spaced from the heat affected zone so that upon reversal of the curvature of the disc element, the disc element will bend about the fulcrum member at a location removed from the heat affected zone.

2. The method according to claim 1 in which the weld slug has a post received through an aperture in disc element.

3. The method according to claim 1 in which the fulcrum member is configured as a washer.

4.The method according to claim 3 in which the fulcrum member extends along the second face surface of the disc element from the heat affected zone a distance greater than does the weld slug on the first face surface of the disc element.