Electrical limit switch

Claim 2

An electrical switching device comprising, in combination, switch means for completing and breaking an electrical circuit in response to mechanical actuation, a first member, said switch means being mounted on said first member, a second member rotatably secured to said first member, an actuating member, means for movably mounting said actuating member on said second member for engaging said actuating member with said switch means and actuating said switch means, and means for rotating said second member relative to said first member through an indefinite number of positions in response to the receipt of a driving force applied to said rotating means, and for holding said second member against rotation relative to said first member when said second member is in a selected one of said positions.

Claim 3

Apparatus as in claim 1 in which said holding means includes a worm gear on one of said first and second members and gear teeth on the other of said first and second members, the teeth of said worm being meshed with said gear teeth.

Claim 4

Apparatus as in claim 1 in which said first and second members are housings, and in which said holding means includes a worm gear on one of said first and second housings and gear teeth on the other of said first and second housings, the teeth of said worm being meshed with said gear teeth, said worm having a shaft with at least one end being exposed to the exterior of said housings and adapted for being gripped for turning and rotation of the second housing.

Claim 5

Apparatus as in claim 2 in which said second member is a substantially cylindrical housing, said worm gear being mounted on said first member, said gear teeth being formed in the lower edge of the exterior of said housing.

Claim 6

An electrical switching device comprising, in combination, switch means for completing and breaking an electrical circuit in response to mechanical actuation, a support structure, a shaft rotatably mounted on said support structure, cam means on said shaft, a cam follower, said shaft being movable longitudinally in said support structure, said cam means having at least two portions spaced longitudinally on said shaft, one of said portions being shaped to move said cam follower upon the rotation of said shaft in one direction but not in the other, and the other of said portions being shaped to move said cam follower upon the rotation of said shaft in said other direction.

Claim 7

An electrical switching device comprising, in combination, switch means for completing and breaking an electrical circuit in response to mechanical actuation, a support structure, a shaft rotatably mounted on said support structure, cam means on said shaft, a cam follower, said shaft being movable longitudinally in said support structure, said cam means having at least two portions spaced longitudinally on said shaft, one of said portions being shaped to move said cam follower upon the rotation of said shaft in one direction but not in the other, and the other of said portions being shaped to move said cam follower upon the rotation of said shaft in said other direction.

Claim 8

Apparatus as in claim 5 in which each of said cam portions is a separate cam, each cam having substantially the same shape as the other cam, with one cam being positioned on said shaft in an orientation opposite to that of the other cam.

Claim 9

Apparatus as in claim 5 including releasable means for locking said shaft in each of a plurality of longitudinal positions.

Claim 10

Apparatus as in claim 6 in which said shaft has a plurality of longitudinally spaced-apart grooves, a locking member shaped to fit into each of said grooves, spring means urging said locking member towards said grooves, and means operable for selectively disengaging said locking member from each of said grooves, two of said grooves each being located so as to bring only one or the other of said cams into engagement with said cam follower, and a third groove located intermediate said two grooves so as to bring said cam follower into engagement with both of said cams simUltaneously.

Claim 11

Apparatus as in claim 5 including spring-biased means for returning said shaft to an initial position at which said follower is not depressed, said means including a pair of parallel springs each capable of so returning said shaft.

Claim 12

Apparatus as in claim 5 including an arm secured to said shaft and a roller mounted on said arm.

Claim 13

An electrical limit switch comprising, in combination, switch means for completing and breaking an electrical circuit in response to mechanical actuation, a first member, said switch means being mounted on said first member, a second member rotatably secured to said first member, a shaft, means for mounting said shaft on said second member so that said shaft is rotatable and movable longitudinally with respect to said second member, cam means having separate portions on said shaft, each of said separate portions being shaped to move said cam follower on the rotation of said shaft in one direction but not in the other, said one direction for one of said portions being opposite to said one direction for another of said portions, and means for holding said second member against rotation with respect to said first member at one of a plurality of positions of rotation of said second member with respect to said first member.

Claim 14

An electrical limit switch comprising, in combination, switch means for completing and breaking an electrical circuit in response to mechanical actuation, a first member, said switch means being mounted on said first member, a second member rotatably secured to said first member, a shaft, means for mounting said shaft on said second member so that said shaft is rotatable and movable longitudinally with respect to said second member, cam means having separate portions on said shaft, each of said separate portions being shaped to move said cam follower on the rotation of said shaft in one direction but not in the other, said one direction for one of said portions being opposite to said one direction for another of said portions, and means for holding said second member against rotation with respect to said first member at one of a plurality of positions of rotation of said second member with respect to said first member.

Claim 15

Apparatus as in claim 11 in which the point of engagement between said cam follower and said cam means lies upon the axis of rotation of said second member, and the shape of said follower at said point of engagement is symmetrical with respect to said axis.

Claim 16

Apparatus as in claim 11 in which said holding means includes a worm gear on one of said first and second members and gear teeth on the other of said first and second members, the teeth of said worm being meshed with said gear teeth.

Claim 17

Apparatus as in claim 11 in which each of said cam portions is a separate cam, each cam having substantially the same shape as each other cam, with one cam being positioned on said shaft in an orientation opposite to that of the other cam, a housing around said shaft and cam means, and releasable means for locking said shaft in each of a plurality of longitudinal positions, said means being releasable from the outside of said housing.