| 摘要 |
<p>A foot control of the treadle operated type has a latching mechanism which normally latches the treadle in an inoperative position and which must be released before the treadle can be moved to an operative position. The latch mechanism includes a latch plate which, as the latch mechanism is being set to latch the treadle in its inoperative position, is moved to a restricting position wherein it restricts access to the treadle by the foot of an operator or by a foreign object. The latch plate is yieldably constrained to restricting position after the latch mechanism is set, and must be moved out of its restricting position to re-establish free access to the treadle and release the latch mechanism. The direction in which the latch plate must be moved for moving it out of its restricting position is opposite from the direction in which the treadle must be moved to reach its operative position.</p> |
