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Push On Push Off Switch Locking Mechanism

IP.com Disclosure Number: IPCOM000086516D
Original Publication Date: 1976-Sep-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Dunphy, JJ: AUTHOR

Abstract

It is often desired to have a mechanism for latching a push button switch in the on or off condition with one stroke and to unlatch the switch with another. This is generally called a push on - push off or alternate-action switch mechanism. The figures illustrate such a mechanism.

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Push On Push Off Switch Locking Mechanism

It is often desired to have a mechanism for latching a push button switch in the on or off condition with one stroke and to unlatch the switch with another. This is generally called a push on - push off or alternate-action switch mechanism. The figures illustrate such a mechanism.

In Fig. 1a, the stem 1 of a key button (not shown) is provided with a pivot 2 on which is mounted, for free rotation, a rotating locking pawl 3. A guide block 4, which is rigidly affixed to the housing of the switch mechanism, prevents rotation of pawl 3 whenever the key stem 2 is in the up position, as shown in Fig. 1a. An actuating cam or arm 5 is also rigidly affixed to the housing of the switch in a fixed relationship to the guide block 4 and to the center line of the path of travel of the key stem 1 and its rotating pawl 3.

In Fig. 1b, the key stem 1 has been depressed far enough to bring pawl 3 out of engagement with guide block 4 and into contact with the actuating arm 5. Pawl 3 begins to rotate counterclockwise so that one of the points 6 on pawl 3 becomes laterally displaced beneath the corner 7 of block 4. A return spring (not shown) is normally mounted in the key-switch mechanism about key stem 1, which restores the key stem 1 in the upward direction when downward pressure is released.

In Fig. 1c, the key stem 1 moves upward, as the pressure is released. The corner 6 of pawl 3 has been displaced relative to corner 7 of the guide pad 4 and thus engages it. Pawl 3 will thus rotate an additional amount (Fig. 1d) and will finally come to rest at the position illustrated in Fig. 1e. The adjoining faces of pawl 3 and guide block 4 prevent...