Patent GB-489324-A (GB)
Title: Improvements in door operating apparatus
IPC: E05F15/10
Filed: 1937-11-16
Abstract: 489,324. Door-operating apparatus. NATIONAL PNEUMATIC CO. Nov. 16, 1937. No. 31528. Convention date, Dec. 10, 1936. [Class 65 (i)] Door-operating apparatus comprises a reversible electric motor 1 coupled to an eddy current brake 2, which is energized near the end of the stroke of the motor, while at the same time the speed of the motor is reduced. The motor operates the door through a shaft 12 which is coupled at 24 to the door and is reciprocated by threaded engagement 13 with the motor shaft 7. The circuits for the motor and brake comprise A.C. leads 30-32 for the motor controlled by a switch 33, and D.C. leads 59, 66 for the brake controlled by the motor. To move the door from open to closed position the hand switch 84 is closed and current flows through 32, 82, 84, 85, 86, 87, 31 energizing relay D and closing contacts 40, 41, 42, 43 and opening contacts 38, 39, 44, 45. Current then flows to the motor 1 through 70, 40, 71, door limit switch 72, 73, 74, 75, 31. Relay A is energized, closing contacts 49, 55. The opening of contact 39 breaks the circuit through the field of 2 and the relay winding 64, so that relay C closes contacts and current flows to coil 36 of relay B through 30, 34, 35, 36, 37, 31, energizing B and closing its contacts 47, 53. Operation of A and B supplies current to the field of the motor through the circuits 30, 57, 42, 46, 47, 48, 49, 50 and 32, 43, 58, 52, 53, 54, 55, 56. The motor then opens the door, and when the door begins to open, limit switch 78 closes, and when the door is fully open, the switch 83 is open. When the door is within a certain distance of full open position, switch 27 is moved to connect spring fingers 61, 62 through contact 28. This completes the circuit from the D.C. source through 59, 41, 60, 27, 63, 64, 65, field winding of 2 and wire 66. This starts the braking action of 2. Energization of 64 breaks at 34 the circuit to winding 36 of B, opening contacts 47, 53 so that current flows to field of motor through resistances 80, 81, so that the motor slows down. When the door is at full open position, limit switch 72 opens, breaking circuit to 74 and opening contacts 49, 55 to break the circuit of the motor. To close the door, switch 84 is opened, de-energizing 86, so that relay D returns to position shown in Fig. 2. Current flows to 74 through 38, closing 49 and 55. The circuit to 2 and coil 64 is broken at 41 so that C completes circuit to 36. This completes circuit at 47, 53 to the motor in the reverse sense through 44 and 45. The motor begins to close the door, and limit switch 72 closes while 78 remains closed. When the door is within a certain distance of closed position, 28 breaks circuit with 61 and 62, and completes circuit with fingers 68, 69. Current flows through 39, completing the D.C. circuit to energize the field of 2 and winding 64 of C. This opens circuit to 36 of B, taking short circuit off resistances 80, 81, and slowing down the motor. When door is fully closed limit switch 78 opens, breaking circuit to 74 of B, which in turn breaks the circuit of the motor field. If the door strikes an obstacle when closing, the sensitive edge switch 89 will close, and current will flow from 32 through 82, 83, 88, 89, 90, 91, 92 to 31, causing contacts 93, 94 to close. Contact 93 closes the circuit to the winding 86 of D, thus setting the circuits to open the door. Contact 94 completes a holding circuit from 88 to 90, so that coil 91 of E remains energized. When the door is fully open, 83 will break circuit of 93 and 94, causing 91 to be de-energized and relay E to open. The circuit to 86 is then broken, and D will set the circuits to close the door again.