GB629576A - Improvements in or relating to locks - Google Patents

Abstract

629,576. Spring locks. TELEFONAKTTEBOLAGET L. M. ERICSSON. Oct. 23, 1947, No. 28386. Convention date, Oct. 23, 1946. [Class 44] In a lock comprising means for retaining the latch bolt 22 in the retracted position the lock comprises an operating sector 4 which can be actuated from outside by means of a key, and a blocking sector 11 which operates the latch bolt 22, which sectors are pivotally mounted in a lock case 1 and shaped with cam-like members 5, 12, arranged to cooperate in such a manner that the camlike member on the blocking sector 11 is locked against the camlike member on the operating sector 4 when the operating sector is turned further than the angle corresponding to the withdrawal of the latch bolt 22 from the locked to the retracted position. The latch bolt 22 pressed outwardly by a spring 23 and guided by a pair of pins 20 working in grooves 21 in the lock case 1 and its cover, is attached to a cog bar 19 meshing with teeth 17 on the rotatably mounted blocking sector 11. A cam surface 12 and shoulder 18 are provided on the blocking sector 11, the upper surface of cam 12 being cut' to half thickness near its end to form surfaces 13, 14. A revolving barrel lock is engaged with an aperture 3 of the rotatably mounted operating sector 4 having a cam surface 5 subtending an angle of about 90 degrees, its under surface being cut similarly to cam 12 to provide surfaces 9 and 10. Another surface 6 of smaller diameter extends over 110 degrees of the circumference and terminates in a tooth 7. A vertically sliding blocking bar 16 guided by pins 24 and 25 working in slots therein and pressed downwardly by spring 33 has a guiding surface 28 in contact with a pin 30 on a spring pressed blocking bolt 29, the guiding surface 28 being sloping apart from a short initial horizontal portion. On closing the door the bolts are pressed inwardly by their bevelled surfaces engaging the jamb, the blocking sector is rotated anticlockwise and the blocking bar depressed to rest on the cam surface 12. Thereafter the latch bolt enters a socket in the jamb, the blocking sector 11 is restored to its former position and the blocking bar now sliding fully, blocks the latch by its end surface 26 contacting shoulder 18. A normal key operating the revolving barrel lock will rotate the sector 4, the tooth 7 contacting a shoulder 15 on the blocking bar to lift it and surfaces 10 and 14 interengaging to rotate the blocking sector 11 and release the latch bolt 22. A special key which will rotate the barrel lock further causes the surfaces 9 and 14 to slide past one another and with the cam 5 contacting cam 12 the latter is blocked and the latch bolt cannot be pressed out by its spring. A shallow recess opposite bolt 30 may be provided in the jamb to hold the door when the latch bolt has been so blocked. A stop 8 fixed to the case 1 ensures the operating sector 4 being rotated in the appropriate direction.