Showcase security system

Claim 1

For a showcase including a case portion having a door slides open and closed, a showcase security system, comprising: a lock housing mounted on said door adjacent one side edge thereof; a bar bolt slidably mounted on said housing for sliding toward and away from the case portion; a key operable tumbler cylinder coupled to the bar bolt for thrusting and retracting the bar bolt toward and away from the case portion; key means removably insertable into the tumbler cylinder for operating the tumbler cylinder; the tumbler cylinder permitting removal of the key when the key is in a predetermined angular alignment with the lock housing corresponding to the bar bolt being in a thrust condition; a bolt catch provided on the case portion, where it is in alignment with the bar bolt only when the door is slid fully shut; boss means on said housing and positioned to be engaged by the bar bolt, upon retraction thereof, upon rotation of the key in a sense to retract the bar bolt, by less than an angular amount such as will again bring the key to said predetermined angular alignment, whereby the key is prevented from being withdrawn unless the door is closed and the showcase is locked.