Time delay switch

Claim 2

A switch mechanism comprising: support means, fixed and movable contact means secured relative to said support means, an operator means secured relative to said support means and having a first position wherein said operator means holds said contact means in engagement with each other, and latch means which hold said contact means in engagement with each other for a predetermined interval of time after said operator means is moved from said first position to a second position out of engagement with said movable contact means, said latch means being thermally responsive and including heat generating means, said heat generating means being periodically energized and deenergized by the making and breaking of electrical contact between the latch means and the contact means while said operator means is in said first position whereby the latch means is kept at a constant temperature regardless of the environmental temperature where the switch is located, said heat generating means also being energized when said operator means iS moved from said first position to said second position to move said latch means out of engagement with said contact means whereby said contacts disengage.

Claim 3

The switch as set forth in claim 1 wherein said latch means includes a bimetallic member secured at one of its two ends to said support means, and said heat generating means includes a heating coil secured to said bimetallic member, said coil being energized when the free end of said bimetallic member is in electrical contact with said contact means, the energization of said coil heating said bimetallic member thereby causing said bimetallic member to move out of electrical contact with said contact means and thereby deenergize said coil, the deenergization of said coil allowing said bimetallic member to cool and thereby reestablish electrical contact with said contact means.

Claim 4

The switch as set forth in claim 1 wherein said fixed contact means is secured to said support means, said movable contact means comprises an elongated resilient contact blade means one end of which is secured to said support means, said operator means including cam means, said cam means bearing on said blade means when said operator means is in said first position thereby holding said blade means in contact with said fixed contact means.

Claim 5

The switch as set forth in claim 3 wherein said latch means includes a latch secured to the free end of said bimetallic means, said latch normally disposed in the path of movement of the free end of said blade means thereby preventing said blade means from disengaging from said fixed contact means when said operator means is moved from said first position to said second position, said latch holding said blade means in engagement with said fixed contact means until said bimetallic means is heated sufficiently to move the latch out of the path of movement of the free end of said blade means.

Claim 6

The switch as set forth in claim 4 wherein said operator means has a third position, said second position being between said first position and said third position, said operator means also including a second cam means, said bimetallic member including a projection on the free end thereof, said projection engaged by said second cam means when said operator is moved from said second position to said third position thereby moving said latch out of the path of movement of the free end of said contact blade whereby said blade means disengages said fixed contact means without any time delay interval.

Claim 7

A delayed action switch mechanism comprising support means, a contact means secured to said support means, a flexible contact blade secured at one of its two ends to said support means, operator means mounted relative to said support means and movable to a first position wherein it holds the free end of said blade means in contact with said contact means, and thermally responsive latch means secured relative to said support means, said latch means holding said blade means in engagement with said contact means only when said operator means is moved to a second position out of engagement with said blade means, said latch means including heating means which is energized when said latch means is in engagement with said blade means, the energization of said heating means causing said latch means to disengage from said blade means and thereby deenergize said heating means, upon cooling said latch means moving back into engagement with said blade means so long as said operator means is in said first position whereby the temperature of said latch means remains approximately constant regardless of the temperature of the surrounding environment prior to the movement of said operator means to said second position.

Claim 8

A delayed action switch mechanism comprising support means, a contact means secured to said support means, a flexible contact blade secured at one of its two ends to said support means, operator means mounted relative to said support means and movable to a first position wherein it holds the free end of said blade means in contact with said contact means, and thermally responsive latch means secured relative to said support means, said latch means holding said blade means in engagement with said contact means only when said operator means is moved to a second position out of engagement with said blade means, said latch means including heating means which is energized when said latch means is in engagement with said blade means, the energization of said heating means causing said latch means to disengage from said blade means and thereby deenergize said heating means, upon cooling said latch means moving back into engagement with said blade means so long as said operator means is in said first position whereby the temperature of said latch means remains approximately constant regardless of the temperature of the surrounding environment prior to the movement of said operator means to said second position.

Claim 9

An electric switch mechanism comprising housing means, a contact means secured to said housing means, a resilient contact blade means secured at one of its ends in said housing means, an operator means mounted on said housing means, said operator means having a first position in engagement with said bladE means whereby said blade means is held in engagement with said contact means, and thermally responsive latch means secured in said housing means, said latch means including heat generating means, said heat generating means being energized periodically by intermittent electrical contact between said blade means and said latch means when said blade means is held in engagement with said contact means by said operator means whereby said latch means is kept at a preselected temperature regardless of the temperature of the surrounding environment, said heat generating means also being energized when said operator means is moved to a second position out of engagement with said blade means thereby permitting said latch means to hold said blade means in engagement with said contact means for a time delay period.

Claim 10

An electric switch mechanism comprising housing means, a contact means secured to said housing means, a resilient contact blade means secured at one of its ends in said housing means, an operator means mounted on said housing means, said operator means having a first position in engagement with said bladE means whereby said blade means is held in engagement with said contact means, and thermally responsive latch means secured in said housing means, said latch means including heat generating means, said heat generating means being energized periodically by intermittent electrical contact between said blade means and said latch means when said blade means is held in engagement with said contact means by said operator means whereby said latch means is kept at a preselected temperature regardless of the temperature of the surrounding environment, said heat generating means also being energized when said operator means is moved to a second position out of engagement with said blade means thereby permitting said latch means to hold said blade means in engagement with said contact means for a time delay period.