Overhead door operator

Claim 2

Apparatus for opening and closing a door comprising: a door that is mounted for movement between one position in which it closes an opening and another position generally above the opening, a fluid actuated device including a cylinder, a piston movable therein and a piston rod, first sheave means mounted to said piston rod for rotation and for translating with said rod, second sheave means and stationary means on which said second sheave means is mounted for rotation in spaced relationship with said first sheave means, cable means looped a plurality of times around said first and second sheave means and having opposite free end portions for being attached, respectively, to spaced apart places on said door, pump means operative to supply pressurized fluid to said cylinder to extend said piston rod and translate said first sheave means away from said second sheave means to thereby enlarge the size of said cable loops and create tension in said cable for opening said door, means for closing said door including means for relieving fluid from said cylinder for enabling tension created in said cables by the weight of the door when said door is unclosed, to translate said first sheave means toward said second sheave means and reduce the size of said loops, an elongated member mounted for translating lengthwise in opposite directions in correspondence with said piston rod, limit switch operator means mounted to and adjustably positionable along said elongated member, a plurality of limit switches in the path of travel of said switch operator means for being actuated, respectively, in correspondence with said door reaching its fully open and fully closed positions, motor means for operating said pump means, solenoide operated valve means operable to open and cause said relieving of fluid for closing said door when one of said limit switches is not actuated, means for controlling said valve means to close in response to actuation of said one limit switch when said door reaches the limit of its closing travel, means for controlling said motor means to start for opening said door, and means for controlling said motor means to stop in response to actuation of another of said limit switches when said door reaches the limit of its opening travel.

Claim 3

The apparatus as in claim 1 wherein: said translatable sheave means comprise first and second sheave means in a coaxial pair of sheave means, said stationary sheave means comprise first and second sheave means in a coaxial pair of sheave means, said cable means comprising two separate cables one being anchored at one end and being looped around said first sheave means in opposite pairs and having one of said free end portions, and the other being anchored at one end and being looped around said second sheave means in opposite pairs and having the other of said free end portions.

Claim 4

Apparatus for opening and closing a door comprising: a door that is mounted for movement between one position in which it closes an opening and another position generally above the opening, a fluid actuated device including a cylinder, a piston movable therein and a piston rod, first sheave means mounted to said piston rod for rotation and for translating with said rod, second sheave means and stationary means on which said second sheave means is mounted for rotation in spaced relationship with said first sheave means, cable means looped a plurality of times around said first and second sheave means and having opposite free end portions for being attached, respectively, to spaced apart places on said door, pump means operative to supply pressurized fluid to said cylinder to extend said piston rod and translate said first sheave means away from said second sheave means to thereby enlarge the size of said cable loops and create tension in said cable for opening said door, means for closing said door including means for relieving fluid from said cylinder for enabling tension created in said cables by the weight of the door when said door is unclosed, to translate said first sheave means toward said second sheave means and reduce the size of said loops, electric motor means operatively coupled with said pump means, said means for relieving said fluid including electrically operated valve means, tube means coupling said pump means and valve means to said cylinder, door opening electric relay switch means and door closing electric relay switch means each being selectively operable to conductive and nonconductive states, a first manually operable switch operable to cause said door opening relay switch means to become conductive for energizing said motor means and cause said door to open, door opening limit switch means operative to cause said door opening relay switch means to become nonconductive for deenergizing said motor means when said door is fully open, a second manually operable switch operable to cause said door closing relay switch means to become conductive for energizing said electrically operated valve means to enable fluid to be relieved from said cylinder to close said door, and door closing limit switch means operative to cause said door closing relay switch means to become nonconductive to thereby deenergize said electrically operated valve means when said door is fully closed.

Claim 5

Apparatus for opening and closing a door comprising: a door that is mounted for movement between one position in which it closes an opening and another position generally above the opening, a fluid actuated device including a cylinder, a piston movable therein and a piston rod, first sheave means mounted to said piston rod for rotation and for translating with said rod, second sheave means and stationary means on which said second sheave means is mounted for rotation in spaced relationship with said first sheave means, cable means looped a plurality of times around said first and second sheave means and having opposite free end portions for being attached, respectively, to spaced apart places on said door, pump means operative to supply pressurized fluid to said cylinder to extend said piston rod and translate said first sheave means away from said second sheave means to thereby enlarge the size of said cable loops and create tension in said cable for opening said door, means for closing said door including means for relieving fluid from said cylinder for enabling tension created in said cables by the weight of the door when said door is unclosed, to translate said first sheave means toward said second sheave means and reduce the size of said loops, electric motor means operatively coupled with said pump means, said means for relieving said fluid including electrically operated valve means, tube means coupling said pump means and valve means to said cylinder, door opening electric relay switch means and door closing electric relay switch means each being selectively operable to conductive and nonconductive states, a first manually operable switch operable to cause said door opening relay switch means to become conductive for energizing said motor means and cause said door to open, door opening limit switch means operative to cause said door opening relay switch means to become nonconductive for deenergizing said motor means when said door is fully open, a second manually operable switch operable to cause said door closing relay switch means to become conductive for energizing said electrically operated valve means to enable fluid to be relieved from said cylinder to close said door, and door closing limit switch means operative to cause said door closing relay switch means to become nonconductive to thereby deenergize said electrically operated valve means when said door is fully closed.

Claim 6

The apparatus as in claim 3 including: safety switch means having first and second conductive states, means mounted to said door and operable in response to said door meeting an obstruction to change the state of said safety switch means, and said safety switch means when in said first state maintaining said door closing relay switch means in its said conductive state and said safety switch means when changed to its second state causing said door closing relay switch means to switch to its nonconductive state and causing said door opening relay switch means to switch to its conductive state for energizing said pump motor and causing said door to reverse and move in the open direction away from said obstruction.

Claim 7

The apparatus as in claim 4 wherein said safety switch means includes a pneumatically responsive operator, said means operable to change the state of said switch means is a hose coupled to said operator that responds to deformation by an obstruction by increasing the pressure in it for actuating said operator.

Claim 8

The apparatus as in claim 3 including a third manually operable normally closed switch means operable to simultaneously switch said both of said door closing and door opening relay switch means to their nonconductive states, whereby to stop door opening and door closing.

Claim 9

The apparatus as in claim 3 including: treadle means for being located outside of said door in the path of said door, treadle switch means which has conductive and nonconductive states and changes states in response to a force being applied to said treadle means,

Claim 10

timer means responsive to said treadle switch means changing state for a short interval by initiating a predetermined timing period, and switch means controlled by said timer means to change from a first state to a second state when said timing period is initiated and to change back to a first state when said period expires, said switch means when in said second state controlling said door opening relay switch means to change to its conductive state to thereby cause opening of said door, and said switch means when back in said first state controlling said door opening switch means to change to its conductive state to thereby cause automatic closing of said door.

Claim 11

timer means responsive to said treadle switch means changing state for a short interval by initiating a predetermined timing period, and switch means controlled by said timer means to change from a first state to a second state when said timing period is initiated and to change back to a first state when said period expires, said switch means when in said second state controlling said door opening relay switch means to change to its conductive state to thereby cause opening of said door, and said switch means when back in said first state controlling said door opening switch means to change to its conductive state to thereby cause automatic closing of said door.

Claim 12

The apparatus as in claim 3 including: a radio receiver and relay means energized in response to radio frequency signals being received by said receiver, and a pair of switching circuits controlled by said last named relay means to close simultaneously, said switching circuits being in circuit with said opening and closing limit switch means and with said opening and closing relay switch means, respectively, such that when said radio frequency signal is received when said door is closed said circuit including said opening limit switch means will be closed for switching said closing relay switch means to its conductive state and when said relay means is closed upon receipt of said radio frequency signal said circuit including said closing limit switch means will be closed for switching said closing relay switch means to its conductive state.