| 摘要 |
<p>1344528 Up-and-over door operating mechanism E DORING 19 April 1971 [22 Jan 1970] 20246/71 Heading E2M [Also in Division F2] An up-and-over door 1 is operated by a reversible electric motor 17 which, through reduction gearing drives a crank the pin 31 of which acts on a pivoting lever 4 (or a member 7 rigidly connected thereto) to pivot this lever and so open (or close) the door 1 via lifting linkage and guide linkage, limit switches stopping and reversing the motor 17 after the door is opened (or closed), the crank being pivoted back for an amount equal to at least the preceding pivoting motion. This reverse motion of the crank brings the crank to a position in which it is ready to act upon the member 7 (and so the lever 4) to close (or open) the door. The lever 4 is pivoted on a shaft 5 and is connected at one end to the lower part of the door and at the other end has a counterbalancing spring 16. A bar 13 is pivotally connected to the lever 4 at one end and has a roller 14 sliding in a rail 15 of the door at the. other, an arm 12 being pivotally connected to both the bar 13 and the wall 10 adjacent the door. A similar arrangement is provided at the opposite side of the door to even the load thereon. The limit switches for the motor control may comprise two operated by the crank and two by the member 7, they may be actuated by a spindle nut on a spindle shaft driven by the motor, or they may be operated by a disc on the outport shaft having cams or pins. The electric circuit for controlling the operation is also described.</p> |
