Door operator system using counter circuit for determining limit positions
First Claim
1. Apparatus for opening and closing a door comprising:
- a reversible electric motor coupled to a drive shaft;
transducer means operatively associated with said shaft for generating signals representative of rotations of said shaft;
counter circuit means receiving the signals from said transducer means for generating a count signal when the rotations of said shaft reach a predetermined number, actuatable switch means;
binary circuit means responsive to actuation of said switch means for generating output signals defining a plurality of states including an open cycle, a close cycle and at least one stop state;
first logic circuit means responsive to the output signals of said binary circuit means for selectively operating said motor in a first direction and a second direction when said binary circuit means is in said open and close cycles respectively to thereby drive said shaft to open and close said door, said first logic circuit means being further responsive to the output signals of said binary circuit means for de-energizing said motor when said binary circuit means is in said stop state;
second logic circuit means for switching said binary circuit means from said open cycle to a stop state when said binary circuit means is in said open cycle and said counter circuit means generates said count signal to thereby de-energize said motor when said shaft has turned a predetermined number of revolutions; and
rotation monitor circuit means responsive to the output signals of said transducer means for generating a signal when the rotation of said shaft stops;
said second logic circuit means being responsive to the output signal of said rotation monitor circuit means and an output signal of said binary circuit means representative of the operation of said system in said close cycle to switch said binary circuit means to said open cycle and thereby reverse the direction of said motor when said shaft stops due to an obstruction during a close cycle, said second logic circuit means being further responsive to the output signal of said rotation monitor circuit means and an output signal of said binary circuit means representative of the operation of said system in an open cycle to change the state of said binary circuit means to cause said motor to stop; and
detector means responsive to the output of said counter circuit means indicative of said door'"'"'s being within a predetermined number of counts from a full closed position to modify the operation of said second logic circuit means during a close cycle to permit said binary circuit means to cause said motor to stop during said predetermined count rather than to reverse in direction if an obstruction is encountered as said door approaches the fully closed position.
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Abstract
The shaft driven by a reversible motor for opening and closing a door is provided with at least one reflective surface. An optical source/detector senses rotation of the shaft and generates a pulse each time one of the reflective surfaces passes. A programmable counter circuit counts the pulses in one direction when the door is opened and de-energizes the motor when a predetermined count is reached without the use of mechanical switches. The counter is decremented when the door is closed, and de-energizes the motor when the count returns to zero. Any obstruction will cause the system to stop the door if sensed during opening, or to reverse the door'"'"'s direction if sensed during closing. Provision is made to account for any "coasting" the door may experience due to inertia; and the system will also track and permit small changes in the closed position of the door, as might occur if snow accumulates beneath the door.
92 Citations
12 Claims
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1. Apparatus for opening and closing a door comprising:
- a reversible electric motor coupled to a drive shaft;
transducer means operatively associated with said shaft for generating signals representative of rotations of said shaft;
counter circuit means receiving the signals from said transducer means for generating a count signal when the rotations of said shaft reach a predetermined number, actuatable switch means;
binary circuit means responsive to actuation of said switch means for generating output signals defining a plurality of states including an open cycle, a close cycle and at least one stop state;
first logic circuit means responsive to the output signals of said binary circuit means for selectively operating said motor in a first direction and a second direction when said binary circuit means is in said open and close cycles respectively to thereby drive said shaft to open and close said door, said first logic circuit means being further responsive to the output signals of said binary circuit means for de-energizing said motor when said binary circuit means is in said stop state;
second logic circuit means for switching said binary circuit means from said open cycle to a stop state when said binary circuit means is in said open cycle and said counter circuit means generates said count signal to thereby de-energize said motor when said shaft has turned a predetermined number of revolutions; and
rotation monitor circuit means responsive to the output signals of said transducer means for generating a signal when the rotation of said shaft stops;
said second logic circuit means being responsive to the output signal of said rotation monitor circuit means and an output signal of said binary circuit means representative of the operation of said system in said close cycle to switch said binary circuit means to said open cycle and thereby reverse the direction of said motor when said shaft stops due to an obstruction during a close cycle, said second logic circuit means being further responsive to the output signal of said rotation monitor circuit means and an output signal of said binary circuit means representative of the operation of said system in an open cycle to change the state of said binary circuit means to cause said motor to stop; and
detector means responsive to the output of said counter circuit means indicative of said door'"'"'s being within a predetermined number of counts from a full closed position to modify the operation of said second logic circuit means during a close cycle to permit said binary circuit means to cause said motor to stop during said predetermined count rather than to reverse in direction if an obstruction is encountered as said door approaches the fully closed position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- a reversible electric motor coupled to a drive shaft;
Specification