| 摘要 |
A lock release for folding tables and shelves in which the locking mechanism to prevent accidental pivoting of the top from a horizontal unfolded position to a generally vertical folded position includes a pivotal link member with guiding edges or surfaces for slidably directing a connector element along the link as the top is folded and unfolded. Most advantageously, the lock is double-acting-that is, two distinct manipulations are required to release the locking mechanism. In a preferred embodiment, the link member has an L-shaped guide slot with an elongated main portion and a relatively short end portion. When the top is horizontal, the connector element is located within the slot's end portion and, to permit the connector element to enter the elongated main portion of the slot, the link member must be shifted about its pivotal axis by the user. In addition, to release the connector element for sliding movement along the slot's main portion, the user must also shift a spring-loaded stop plate laterally out of the path of movement of the connector element. The stop plate is hingedly connected to the link member and includes a handle extension so that by gripping and shifting the extension a user may perform both unlocking actions at the same time. In another embodiment the link member is unslotted, but again, movement of the connector element along the link member is normally obstructed by a pivotal spring-loaded stop plate which performs a releasable locking function.
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