Patent GB-216032-A (GB)
Title: Safety lock
IPC: E05B37/12
Filed: 1923-09-06
Abstract: 216,032. Eras, V. J. M., and Lips, H. J. J. M. Sept. 6, 1923. Lock mechanism, trustee; permutation; tumbler-type.-A trustee lock of the type described in Specification 26312/07 having an official's bolt and a lessee's bolt, each with its separate key and in which the lessee's bolt is further controlled by a permutation device, is constructed so that the lessee's bolt shoots the official's bolt if this is imperfectly shot, by a pawl, and also retracts it, if it is not fully retracted. The lessee's bolt cannot be fully withdrawn until the combination is scattered. The means for changing combination is also governed by the lessee's bolt.. The official's bolt 4 and lessee's bolt 3 are guided on a false bottom 1 of a casing 2, tumblers 9, 11 governing the bolt 4 and sets of tumblers 5, 6 governing the bolt 3. The tumblers 5, 6 and 9 are pivoted respectively on posts 7, 8, 10 on the bottom 1, but the tumbler 11 is pivoted on a pin 12 on an extension 13 of the bolt 3 and moves therewith. The bolts 3 and 4 further interengage by projections 21, 20. The bolt 3 carries spring pins 30 housed in boxes 31, recesses being cut in the bottom 1 to allow these to move. These co-operate with notched permutation discs 25 to lock the bolt 3. To operate the lock, the official inserts his key K and withdraws, partly or wholly, his bolt 4. The lessee then sets the discs 25 to align the notches 33 with the pins 30 and inserts his key to operate the tumblers 5 and 6 and withdraw the bolt 3. This bolt can only be partly withdrawn in this condition of the lock by reason of the pins 30 engaging the inner ends of the slots 33. To fully withdraw the bolt 3, the discs 25 are now rotated at random, inclined surface 34 below the discs adjacent to the notches depressing the pins 30 flush with the bolt 3 so that they slide under the discs ready for protrusion for locking when the bolt 3 is again shot. If the official's bolt 4 had been incompletely withdrawn, retraction of the bolt 3 would have completely withdrawn it by the engagement of the projections 21, 20. In the locked condition, the bolt 4 blocks the bolt 3 by reason of these projections. To shoot the bolts, the bolt 3 only is operated, the end 14 of the tumbler 11 pivoted thereon, engaging the stump 15 on the bolt 4 in the unlocked condition, Fig. 6, and acting as a pawl to carry the bolt 4 into locking position with the bolt 3. The discs 25 are turned by drivers 28 to which they are connected by intermediate discs 40, radial projections 41, 43 thereon engaging the discs 25, 28 respectively. The discs 25, 28 are pivoted on posts 29 on the bottom 1 while the discs 40 are held in position by a plate 50. To change the combination, the bolt 3 must be half withdrawn, that is, till the pins 30 are in the notches 33, when the projection 53 on the bolt, engaging a slot 66 in the plate, can allow the plate to be moved to the right by a key 51 causing the projections 43 to clear the notches 44 in the drivers 28 so that these can be freely turned to another combination, the longer projections 41 holding the discs 25 stationary. These are further held by projections 55 on the plate entering the notches 33. The return of the plate 50 causes the projections 43 to engage other notches 44 in the drivers 28. If the plate is not returned to its key, re-shooting of the bolt 3 effects this by means of the projection 53 and slot 66. The discs 25 have false notches 35 co-operating with spring pins 57 to prevent looseness.