| 摘要 |
1471602 Latches MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 27 June 1974 [27 June 1973 (2)] 28495/74 Heading E2A The door 14 of a microwave oven is latched by means of a projecting hook-shaped keeper 15 which is biassed against entry into the latching mechanism in the oven casing, but once in, is latched in place to hold the door closed. The fastening bolt of the latching mechanism may be rotary or sliding, and it is released by push-button 18, Figs. 4 and 5. In the rotary-bolt, push-button released embodiment shown in Figs. 4 and 5, the bolt 29 is biassed to each extreme position, fastening or releasing, by an over-centre spring 35. Closure of the door inserts the keeper 15 so that its nose engages arm 32 on the bolt and rotates it to its other stable (latching) position where it is itself latched by a spring-loaded hook 48 to prevent the door being forced open. The bolt 29 is loosely linked at 41, 43, with lost motion, to a lever 37 pivoted at 38. The top enu of this lever controls the energising switch 44 of the oven, and is itself movable to the de-energising and releasing position shown in broken lines by the push-button 18 acting through a lever 24. This movement first releases the latch by means of pin and slot 42, 49, and then takes up the lost motion at 41, 43 to turn the bolt 29 back to its releasing position, shown in broken lines. The bolt 29 may have several latching ramps on projection 34 (Fig. 7, not shown). Fig. 8 shows an arrangement in which a sliding latch-bolt 55 is retracted by the push-button through bell-crank-lever 64, 65. This lever has a cranked portion 65a which engages a blocking lever 66 in such a way that it (and the bolt) is held down until the nose of the keeper 15 tilts the lever 66 by engaging its top part 68. |
