Patent ID: 7331203

Claim:
A merchandise lock comprising: a hollow shell; a hollow external sleeve mounted on the shell and having a notch formed through the sidewall of the external sleeve; and a through hole formed through the external sleeve; an internal sleeve mounted in the shell, mounted securely in the external sleeve and having a mounting recess formed axially in the internal sleeve; a notch formed through the internal sleeve communicating with the mounting recess of the internal sleeve and corresponding to the notch of the external sleeve; and a first spring mounted in the internal sleeve and extending into the mounting recess in the internal sleeve; at least one stationary locking sheet mounted in the mounting recess in the internal sleeve, extending out of the external sleeve, and each one of the at least one stationary locking sheet having a locking recess formed in the stationary locking sheet; and a stationary tongue formed on the stationary locking sheet, extending out of the through hole in the external sleeve and having a protrusion formed on the stationary tongue; a movable locking sheet mounted pivotally in the mounting recess, pushed by the first spring, extending out of the external sleeve and having a locking recess formed in the movable locking sheet and selectively aligning with the locking recess in the at least one stationary locking sheet; a movable tongue formed on the movable locking sheet, extending out of the through hole in the external sleeve, selectively aligning with the stationary tongue of the at least one stationary locking sheet and having a protrusion formed on the movable tongue; and a stem formed transversely on a side edge of the movable locking sheet, extending through the notch in the internal sleeve and extending out of the notch of the external sleeve; a lock cylinder mounted in the internal sleeve and having an extension rod extending out of the lock cylinder and selectively engaging with the locking recesses of the movable and at least one stationary locking sheets; and a second spring mounted in the internal sleeve and mounted around the extension rod on a stationary segment, wherein when the locking recess of the movable locking sheet aligns with the locking recess in the at least one stationary locking sheet, the movable tongue misaligns with the stationary tongue on the at least one stationary locking sheet; when the movable tongue aligns with the stationary tongue on the at least one stationary locking sheet, the locking recess of the movable locking sheet misaligns with the locking recess in the at least one stationary locking sheet; when the lock cylinder is locked, the extension rod engages with the locking recesses of the at least one stationary and movable locking sheets; and when the lock cylinder is unlocked, the extension rod disengages from the locking recesses of the at least one stationary and movable locking sheets.