Browse Prior Art Database

Interlock Switch

IP.com Disclosure Number: IPCOM000091794D
Original Publication Date: 1968-May-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Keller, RJ: AUTHOR [+2]

Abstract

Tamper-proof switch assembly 10 includes plastic case 11 which completely encloses switch 12, spring arm 13 and permanent magnet 14. The The latter is attached to one end of 13. The other end of 13 is embedded in wall 15 of 11. Spring 13 is formed with rib 16 which is engaged by switch plunger 17. This is biased so as to hold magnet 14 against wall 18, when cover 20 is not within proximity of assembly 10 as in drawing A. Permanent magnet 21 is fixed to cover 20 and is oriented so that like poles are opposite each other when cover 20 is in a position so as to bring 21 within proximity of assembly 10 as in drawing B. With cover 20 in this position, 14 is repelled so that spring 13 is deflected to depress plunger 17 which in turn transfers the contacts, not shown, of switch 12.

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Interlock Switch

Tamper-proof switch assembly 10 includes plastic case 11 which completely encloses switch 12, spring arm 13 and permanent magnet 14. The The latter is attached to one end of 13. The other end of 13 is embedded in wall 15 of 11. Spring 13 is formed with rib 16 which is engaged by switch plunger 17. This is biased so as to hold magnet 14 against wall 18, when cover 20 is not within proximity of assembly 10 as in drawing A. Permanent magnet 21 is fixed to cover 20 and is oriented so that like poles are opposite each other when cover 20 is in a position so as to bring 21 within proximity of assembly 10 as in drawing B. With cover 20 in this position, 14 is repelled so that spring 13 is deflected to depress plunger 17 which in turn transfers the contacts, not shown, of switch 12. With this arrangement it is difficult to override the interlock switch.

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