Automatic reversing control equipment |
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| 申请号 | US47076074 | 申请日 | 1974-05-17 | 公开(公告)号 | US3899726A | 公开(公告)日 | 1975-08-12 |
| 申请人 | ALLISTER MFG CO; | 发明人 | ELLMORE JOHN W; | ||||
| 摘要 | Control equipment for a reversible electric motor for driving a mechanism such as a garage door operator is disclosed. The control equipment includes a pressure responsive device for moving a movable switch element between first and second motor energizing positions in a circuit. The movable switch element in one of the circuit positions conditions the motor for operation in one direction, and in the other of the circuit positions conditions the motor for operation in another direction. The equipment further includes a relay normally selectively energizable by an operator controlled switch to alternately complete first or second motor energizing circuit paths, depending upon the position of the switch elements, to permit movement of the mechanism in the direction desired. In order to reverse the door when it encounters an obstruction in closing, a circuit is provided to the relay which bypasses the operator controlled switch. The pressure responsive device first operates a bypass switch in the bypass circuit and then moves the aforesaid movable switch element to the one of its positions which conditions the motor for operation in a direction reverse to the direction in which the motor was operating at the time the obstruction was encountered. Simultaneously, the movable switch element closes contacts which complete the bypass circuit, thereby energizing the relay to complete the motor circuit causing the motor to operate in the reverse direction. Means are provided for disabling the bypass switch, thereby preventing energization of the relay via the bypass circuit at the close limit of door travel. First and second thermal cutouts are provided for preventing unduly repetitious operation of the motor and to provide motor protection. | ||||||
| 权利要求 | 1. A drive system including a reversible motor for driving an element between limit positions, and a control circuit for the motor comprising a power supply circuit for supplying power to the motor, a switch means in the supply circuit for controlling the supply of power to the motor, a control circuit for controlling the switch means, the control circuit including an actuating switch for controlling the operation of the switch means, a first thermal switch which opens in response to an increase in the operating temperature of the motor above a first predetermined temperature for disabling the actuating switch, and a second thermal switch which opens in response to an increase in operating temperature of the motor above the first predetermined temperature for interrupting the supply of power to the motor. 2. Apparatus as in claim 1 wherein the switch means comprises a latching ralay. 3. Apparatus as in claim 1 wherein the first thermal switch is in series circuit relationship with the actuating switch. 4. A drive system comprising a reversible electric motor having a pair of windings and capacitance means for determining the direction of rotation of the motor, a first switch for energizing the windings including first contact means for energizing the windings in a manner to cause rotation of the motor in one direction and second contact means for energizing the windings in a manner to cause rotation of the motor in the other direction, a second switch for supplying power from a supply source alternatively to the first and second contact means of the first switch, an actuating means for controlling the first switch, first thermally responsive means for disabling the actuating means in response to a rise in temperature of the motor above a predetermined temperature, and a second thermally responsive means for interrupting the supply of power to the motor in the event the temperature of the motor rises above said predetermined temperature. 5. Apparatus as in claim 4 wherein the first switch means is a latching relay. 6. Apparatus as in claim 5 wherein the second switch is a double pole double throw switch. 7. Apparatus as in claim 4 wherein the first thermally responsive means is a thermal switch in series circuit relationship with the actuating switch. |
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