Cylindrical locks are well known and have been widely used in computers, TV games, elevators, doors, motorcycles, etc., for a long time. The above cylindrical locks (as shown in FIGS. 1 and 2) are constructed by a housing 101, a lower pin seat 102 mounted in the housing 101, a spindle 103, a plurality of springs 104, and plural sets of upper and lower pins 105. However, such a construction has following disadvantages:
(1) As shown in FIG. 2 , during assembly of the pins 105, pins 105 are inserted into the spindle 103 by operators, and pressed against the housing 101 by means of the springs 104. Hence, the pins 105 may be easily popped out of the spindle 103 due to an undesired collision between the housing 101 and the spindle 103 as a result of improper movement of either housing or spindle by operators. Therefore, skilled persons are required to prevent the waste of time to repeat assembly work which, however, substantially increases costs.
(2) In order to prevent the removal of the pins 105 from the spindle and facilitate the assembly, the gap between the housing 101 and the spindle 103 and the lower pin seat 102 should be enlarged. However, such a gap permits the spindle to sway or have angular movement and, hence, a smooth rotation of the spindle 103 can not be obtained.
(3) As shown in FIG. 1, if the opening 111 of the of the housing 101 is too large or enlarged by an external force or the friction of the outward protruding wing 61 of the key after a short period of use, the pins 105 will be easily popped out and the lock can not work.
The present invention aims at eliminating the above said disadvantages, and provides an improved cylindrical lock, where the pins will not be easily popped out, and the top of the annular wall of the spindle can tightly press against the housing, so that the spindle will not sway. Further, the angular position of the spindle of the present invention is more precise and its rotation is also more smooth.
The present invention will become apparent from the detailed description with reference to the accompanying drawings which are given by way of illustration only, and thus are not limitative of this invention.