Combination lock having sensing means for dialing aid and anti- sensing means for security purpose

摘要

A combination lock includes a lock body, having a hollow spindle laterally protruding outwardly, a locking bolt having a plurality of projections formed on the bolt insertably into the hollow spindle adapted for locking the lock, a plurality of dials normally coupled with sleeves rotatably mounted in the lock body having a plurality of annular corrugated teeth formed on an inner ring of each sleeve retarding the withdrawal of the projections of the bolt to prevent a trial opening by touch feeling by an intruder when rotating the dials in order to find out an opening slot formed in the sleeves for withdrawing the locking bolt, a plurality of positioner plates slidably held on the spindle for rotatably clickingly engageable with the sleeves for helping sensing a subsequent dialing operation from numeral to numeral; and a combination-changing plate pre-inserted in the locking bolt for pushing the sleeves inwardly to disengage their coupling with the dials for free rotation of dials for re-setting a new combination.