| 摘要 |
<p>608,289. Door - operating appliances. STEVENS, A. H. (Wread Overhead Door Co.). March 13, 1946, No. 7824. [Class 65 (i)] [Also in Group XXXVII] Apparatus for moving a door D pivoted about a horizontal axis between vertical closed and horizontal open positions comprises a motor M driving a vertical shaft, a horizontal arm 45 fixed to the shaft and extended in a plane above the top of the door, and a connection. C having a universal joint at each end between the arm and the top of the door. As shown, the arm rotates unidirectionally about the axis of the vertical shaft, during half a revolution of which the door is moved from the closed to the open position or vice versa. The motorcontrol system is adapted for use with the door of a garage. The main circuit comprises the motor and the contacts 113A-115 of a double contact relay R urged normally to the open position. A secondary circuit comprises the secondary coil of a transformer T, a master switch S2, the coil r of the relay, and a switch S1 installed in the garage driveway and adapted to be closed momentarily by the passage thereover of the wheel of a car. A branch secondary circuit connects in parallel with the switch S1, the contacts 112A-114 of the relay and a switch S3. The latter is normally urged to the closed position and is adapted to be held open, when the door occupies either the fully closed or fully open position, by a two-armed cam 80 mounted on the motordriven, vertical shaft. A car approaching the closed door crosses the switch S1, whereby the relay is energized, the motor starts, switch S3. closes and the motor continues to run until the door is fully open. A push-button switch S connected in parallel with switch S1 enables the door to be closed.</p> |
