1. Field of the Invention
This invention relates to a connector with a locking mechanism for connecting a plug and a socket.
2. Description of the Prior Art
As the locking mechanism of such a connector, there is desired one which can lock a plug and a socket to each other when a cord connected to the plug is pulled and release the lock to permit ready detachment of the plug from the socket when the plug is pulled by holding the outer periphery thereof.
To meet this demand, a device has been proposed, which is disclosed in Japanese Utility Model Publication No. Sho 62-17995 (equivalent to U.S. Pat. No. 4,548,455).
This device is shown in FIGS. 17 and 18 of the present application. As shown, the plug side is provided with a locking piece B with a locking portion A and an insertion piece C, while the socket side D is provided with an annular groove E and a locking recess F, in which the locking portion A on the plug side is engaged. When the cord connected to the plug is pulled with the plug and socket connected together, the locking portion A is moved in unison with the insertion piece C to be locked. When the outer periphery of the plug other than the cord is pulled, only the insertion piece C is first removed from the annular groove E, and then the locking portion A is removed from the recess F with elastic downward displacement.
When this well-known means is implemented as an actual product, it often occurs that the plug is easily taken out from the socket D by slightly strongly pulling the cord connected to the plug. This occurs due to the fact that in the presently available plug product the locking piece B is formed by making use of a portion of a cylinder of the plug body made from a metal sheet with a thickness of 1 mm or less, the fact that the insertion piece C and locking portion A are respective synthetic resin molding and the fact that when the cord connected to the plug is pulled, a force is applied to the locking portion A and insertion piece C by the recess F in a direction of squeezing these parts so that the lock is released more readily than is theoretically conceivable.