Lock-structures

Claim 1

A door lock comprising a casing having a pair of spaced substantially parallel sidewalls having longitudinal front edges; a pair of hook-shaped locking members each pivotally mounted in the region of one end thereof on said sidewalls for movement between a retracted position within said casing and a locking position in which said locking members project with portions thereof beyond said longitudinal front edges; means for moving said locking members between the positions thereof and including slide block means and a pair of links pivotally connected to said slide block means and said locking members, said slide block means being provided with a slot extending substantially parallel to said front edges of said sidewalls; cooperating guide means on said slide block means and one of said sidewalls for guiding said slide block means movable toward and away from said front edges; spring biased latch means comprising an elongated latching bar movably guided in said slot between a latching and a releasing position, said latching bar having inwardly extending opposite ends substantially normal to the portion of the bar which is guided in said slot; a single projection protruding from one of said sidewalls arranged to laterally engage one side of one of said inwardly extending ends of said bar when the latter is in said latching position, to prevent said slide block to move toward said longitudinal edges and movement of said locking members from said retracted to said locking position; and rotatable cylinder means mounted in said casing and having a radially extending projection arranged to engage upon rotation of said cylinder means in one direction first the other of said inwardly turned ends of the locking bar to move the latter against the spring bias to said releasing position in which said one inwardly turned end is moved out of lateral engagement with said projection on said sidewall and to subsequently engage the thus freed slide block means to move the latter laterally towards said longitudinal edges and the locking members from said retracted to said locking position, said spring biased means moving back to its latching position after said slide block means has moved laterally so that said one inwardly turned end of said latching bar engages said projection on the sidewall on the other side of the latter to prevent movement of said slide block means in a direction away from said longitudinal edges to thus hold said locking members in said locking position.