PURPOSE: To improve a pledge lock, and to unlock the bonding member of the lock by the specific shape or design of a card having simple constitution.

CONSTITUTION: A lock has a casing 1 installed to the first trolley, and an opening for a pledge and an opening for a bonding member are formed to the casing 1. The bonding member is mounted on the second trolley, and is being locked by a closure bolt unit the pledge is inserted. The pledge is used as the card moving a control member during insertion, and the control member moves the closure bolt 4 from the position of locking to the position of unlocking. The card has at last the first zone, in which the card is bent regarding a residual section from a card surface, and the second card zone by a lock projection 14 extended into a card inserting path. The first zone collides with a stop for the control member directly or through an intermediate member under a bent state, and moves the control member.