No title available

• US 3,715,535 A
• Filed:
• Issued:
• Est. Priority Date: 07/20/1971
• Status: Expired due to Term

• Current Assignee: N/A
• Original Assignee: N/A
• Time in Patent Office: Days
• US Class Current: 200/61.53
• CPC Class Codes: H01H 35/14 Switches operated by change of acceleration, e.g. by shock or vibration, inertia switch wherein the liquid constitutes a contact of the switch H01H29/002

Abstract

An electrical switch actuatable at one or more levels of acceleration including a sealed tubular housing having spaced apart reset actuate walls with damping fluid filling a chamber therebetween, a movable sensing mass within the chamber carrying a shorting conductive member, a helical spring intermediate the actuate wall and the sensing mass to position the sensing mass at an initial location adjacent the reset wall and to resist movement of the sensing mass when the mass is subjected to acceleration forces, electrical contacts extending through the housing walls into the chamber in the path of movement of the shorting member, and means carried by a housing wall accessible from the exterior of the housing for moving at least one of the contacts to a position in substantially transverse alignment with another contact for generally simultaneous contact with portions of the shorting member after some desired movement of the sensing mass. Provision is also made by means of an annular orifice to minimize circuit closures from extraneous shocks and by a bimetallic curved ring to compensate for temperature caused changes in spring characteristics.

Claims

1. An acceleration actuated switch comprising a sealed tubular housing including an inner wall and spaced apart reset and actuate walls forming an enclosed chamber therebetween and an annular portion projecting inwardly beyond said inner wall into said chamber intermediate and spaced from said reset and actuate walls;

a damping fluid filling said chamber;

a sensing mass within said chamber having all portions spaced from said inner wall of said housing and including an electrically conductive ring having a leading edge portion at the exterior of said sensing mass, said sensing mass being movable between an initial location and secondary locations and including an outwardly projecting annular portion adjacent and in registry with said inwardly projecting portion at said initial location and forming therewith an annular restricted orifice at said initial location for metering of said damping fluid only during initial movement of said mass and forming with said inner wall when out of said registry an annular widened opening;

helical spring means for yieldably positioning said sensing mass at said initial location adjacent said reset wall and resisting movement of said sensing mass toward the actuate wall when said mass is subjected to acceleration forces;

a plurality of electrical conductor pairs carried by and extending through at least one of said housing walls into said chamber with each conductor of said conductor pairs carrying an electrical contact normally spaced radially outwardly from said sensing mass but disposed in the path of movement of said electrically conductive ring between said initial and a secondary location, one of said electrical contacts of each pair being positioned adjacEnt one of several of said secondary locations and registering with said conductive ring when the sensing mass is at said secondary locations; and

means carried by said one housing wall and accessible from the exterior of said housing for selectively positioning the other of said electrical conductors of each pair and its electrical contact to contact with said leading edge portion of said electrically conductive ring at each of said secondary locations corresponding with said other positioned contacts of said conductor pairs.

2. The switch of claim 1 wherein each of said selectively positionable conductors are slidably supported within recesses and passageways of said housing with threaded portions extending through said housing to the exterior thereof.

3. The switch of claim 2 wherein each of said recesses and passageways of said housing includes an annular shoulder and said switch includes an annular member threaded about said conductor threaded portions abutting against said annular shoulder.