GB828321A - Improvements in or relating to locks - Google Patents

Abstract

828,321. Key locks. SPEGELSTEIN & SON Ltd. July 19, 1957 [Aug. 2, 1956], No. 23938/56. Class 44 A lock comprises a body, a latch member 11 slidably mounted in the body and biased so that a nose portion 10 of the latch member protrudes from the body and a tumbler element 22 slidably mounted in the body and biased into engagement with the latch member either to maintain the latch member in a locked position or to prevent it being moved into the locked position, the latch member and tumbler element each being biased by means of a coil spring 15, 22 and the direction of movement of the latch member being at right angles to the direction of movement of the tumbler element. The body comprises a base 1 surrounded by four upstanding walls 2, 3, 4 and 5 the walls 2 and 4 having Ranges 6 and 7 provided with fixing holes 8. The latch member extends through an opening 9 in the wall 5, and the coil spring 15 is positioned between the wall 3 and a recess 14 in the latch member. The latch member is guided by a pin 13 on the base 1 engaging a slot 12. The tumbler element 22 is provided with a tab 21 extending perpendicularly and which is engageable with an abutment 20 on the latch member. As shown the tab 21 is on the left hand side of the abutment 20 so that the latch member can be retracted against the pressure of the spring 15 by closing movement of the door to which the lock is secured. The engagement of the abutment 20 with the tab 21 prevents the latch member moving to its locking position in which it protrudes further from the body. The latch member can also be withdrawn from the latching position shown by means of a key 18 inserted through a keyhole in the base 1. Clockwise rotation of the key brings it into engagement with an abutment 19 on the latch member and further rotation of the key withdraws the nose of the latch member into the body. To move the latch member to its locking position the key is rotated anti-clockwise and it then initially contacts a surface 17 on the latch member and moves it to. the right; further rotation of the key causes it to engage a flange 28 on the tumbler element to raise the tumbler element against the action of the coil spring 26, when the tumbler element has been raised sufficiently to allow the abutment 20 to pass underneath the raised tab 21 the pressure of the spring 15 moves the latch member so that the projection 20 passes under the tab 21 until the movement is limited by the pin 13 engaging the end of the slot 12, the continued rotation of the key allows the tumbler element to move downwardly under the action of the spring 26 and this moves the tab 21 to a position to the right of the abutment 20 so that the latch member cannot be moved from its locking position without using the key in the reverse manner. The nose 10 may be provided either with one angled surface or with two angled surfaces in which case the door can be opened merely by pulling it.