Door lock with elongated spring bolt

Abstract

The invention relates to a door lock with lengthened lock tongue, comprising lock casing, lengthened square tongue with bracket, shift fork, location plate, and push plate, where the push plate is arranged on the location plate, the first and second side surfaces of the push plate are inclined in the same direction, the first and second limit columns are arranged in the corresponding positions in the lock casing to cooperate with the first and second side surfaces, and it has a tendency to gradually move to the shift fork through the push plate under the action of the limit columns and the two inclined side surfaces, so as to lengthen the contact pushing time of the driving part and the push plate in the course of the shift fork rotating by a circle, therefore it plays the role in pushing the lengthened square tongue completely out of the lock casing, thus raising its locking grade; besides, the push plate and the lengthened square tongue have large contact area so that it is steady to drive.

Description

technical field [0001] The invention relates to the technical field of locks, in particular to a door lock with an elongated dead bolt. Background technique [0002] In order to increase the anti-theft function of the existing double-tongue double-head safety door lock, it often uses an elongated square tongue, so that the square tongue can be stretched out of the lock housing as long as possible and enter the matching lock hole. This can enhance the anti-theft performance of the door lock. Therefore, there is one on the market that can extend the square tongue out of the lock case in multiple stages. When we insert the key into the lock hole and turn it a few more times, the shift fork drives the square tongue to the maximum extent. Stretch out the lock shell, to achieve the purpose of enhancing the anti-theft performance. [0003] Such as a Chinese utility model patent "Dual Tongue Double Lock Safety Door Lock" whose patent number is ZL90211528.6 (announcement number is C...

AI Technical Summary

Problems solved by technology

This European patent drives the linkage rod pivotally connected to the lock shell to rotate by rotating the cam, so that the end of the linkage rod in contact with the lock tongue pushes the lock tongue to extend outwards, and utilizes the principle of leverage, so that the key can be turned once. The purpose of pushing the lock tongue to extend out is the defect that the part of the linkage rod that pushes the lock tongue out has a very small active surface, which can be regarded as a point-to-surface contact, so it will drive the lock tongue to extend out. not so stable

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