| 摘要 |
A GATE CLOSURE DEVICE INCLUDES AN ELECTRIC MOTOR AND GEAR BOX. AN ELECTRICALLY OPERABLE LOCK PREVENTS ROTATION OF THE MOTOR UNLESS POWER IF APPLIED TO A COIL TO RELEASE THE LOCK. THIS PREVENTS UNAUTHORISED MANUAL OPENING AND CLOSING OF THE GATE. AUTHORISED OPERATION OF THE GATE, IN THE ABSENCE OF A POWER SUPPLY, IS MADE POSSIBLE BY A KEY OPERATED LOCK 21 WHICH IS USED TO DISENGAGE A DRIVE CONNECTION IN THE GEAR BOX. THE GATE CAN THEN BE PUSHED OPEN OR CLOSED.(FIG. II)
|
