Garage door power operator having partial open capability

Claim 2

In a power door operator of the type including a motive power source and a reversing means for alternately establishing up and down energizing circuits through the source causing the load to be driven in opposite directions upon successive actuations thereof, the improvements comprising: a screw shaft driven by the source, first and second normally spaced-apart nuts threadedly engaging the shaft and driven linearly therealong according to the direction of shaft rotation, means for permitting individual adjustment of the relative linear positions of the first and second nuts on the shaft to define respective up and down limits of travel, and memory means including a member disposed adjacent the shaft and freely and cyclically displaceable by the nuts between first and second positions each time the nuts reach their respective limits of travel and to remain in such positions until the nuts approach the opposite limit of travel, said memory means being operative to disable the down energizing circuit when in one of said positions whereby actuation of the reversing circuit during upward travel of the load causes the source to be deenergized.

Claim 3

Apparatus as defined in claim 1 further including a support means for carrying the screw shaft, said memory means member including a lever pivotally mounted on the support means and having first and second fingers extending toward opposite ends of said screw shaft be pivoted between said first and second positions by the first and second nuts, respectively, each time said nuts approach respective limits of travel.

Claim 4

Apparatus as defined in claim 2 wherein said memory means further include a relatively high-friction pivotal mounting for said lever whereby said lever tends to remain in each of the two positions of pivotal orientation thereof until positively displaced by one of said nuts toward the other of said positions.

Claim 5

Apparatus as defined in claim 2 wherein said reversing circuit further comprises up and down limit switches disposed on said support means adjacent opposite ends of said screw shaft, the up limit switch being actuated directly by one of said nuts and the down limit switch being actuated by the other of said nuts through said actuator lever.

Claim 6

Apparatus as defined in claim 4 including input means comprising an input switch for controlling operation of said power source, and relay switch means responsive to operation of the input switch to alternately connect an electrical power source to the motive power means through the up and down limit switches, respectively.

Claim 7

In a power operator for garage doors and the like: a motive power source capable of driving a garage door in opposite directions between up and down limits of travel; a screw shaft driven by the source; first and second individually adjustable nuts mounted on the shaft for linear rotation therealong and defining said up and down limits; a support bracket; a first switch carried by the bracket for controlling a first circuit to the source for driving the shaft in one direction; a second switch carried by the bracket for controlling a second circuit to the source for driving the shaft In the opposite direction; a bistable relay switch for alternately connecting a source of electrical energy to the first and second switches, respectively; and an actuator lever freely pivotally mounted on the bracket adjacent the screw shaft and the first switch and cooperating with the first and second nuts to pivot with each cycle of door operation between a first position corresponding with the down limit and a second position corresponding with the up limit, the lever being operatively engageable with the first switch for holding the switch in the open circuit condition while said lever is in the first position whereby the relay switch operates only to energize the power source in the up direction as long as the lever is in the first position.

Claim 8

In a power operator for garage doors and the like: a motive power source capable of driving a garage door in opposite directions between up and down limits of travel; a screw shaft driven by the source; first and second individually adjustable nuts mounted on the shaft for linear rotation therealong and defining said up and down limits; a support bracket; a first switch carried by the bracket for controlling a first circuit to the source for driving the shaft in one direction; a second switch carried by the bracket for controlling a second circuit to the source for driving the shaft In the opposite direction; a bistable relay switch for alternately connecting a source of electrical energy to the first and second switches, respectively; and an actuator lever freely pivotally mounted on the bracket adjacent the screw shaft and the first switch and cooperating with the first and second nuts to pivot with each cycle of door operation between a first position corresponding with the down limit and a second position corresponding with the up limit, the lever being operatively engageable with the first switch for holding the switch in the open circuit condition while said lever is in the first position whereby the relay switch operates only to energize the power source in the up direction as long as the lever is in the first position.

Claim 9

In a power door operator including a reversible electric motor and means for establishing first and second circuits through the motor for causing rotation of the motor in opposite directions: first and second limit switches and first and second independently adjustable traveling members for operatively engaging respective limit switches to establishing the opposite displacement limits for said operator, and memory means operated by said traveling members during each cycle thereof to maintain one of the limit switches in an open circuit condition after being placed in such condition by a first traveling member substantially reaching one of said limits and until the other traveling member substantially reaches the other of said limits.

Claim 10

In a power door operator including a reversible electric motor and means for establishing first and second circuits through the motor for causing rotation of the motor in opposite directions: first and second limit switches and first and second independently adjustable traveling members for operatively engaging respective limit switches to establishing the opposite displacement limits for said operator, and memory means operated by said traveling members during each cycle thereof to maintain one of the limit switches in an open circuit condition after being placed in such condition by a first traveling member substantially reaching one of said limits and until the other traveling member substantially reaches the other of said limits.