Patent GB-306461-A (GB)
Title: Improvements in and relating to locks, particularly applicable to padlocks and to strap fastenings for mail bags and the like
IPC: E05B37/00
Filed: 1929-02-20
Abstract: 306,461. Forloni, E. Feb. 20, 1928, [Convention date], Locks and fastenings operating registering and counting apparatus; locks, controlling operation of; padlocks; strap fastenings. - A lock or fastening of padlock type particularly for securing mail-bags and doors of railway wagons is provided with members actuated by operation of a key or spindle to alter a combination of symbols exhibited through a window aperture, a note of the symbols shown when the lock is fastened being noted on a label in the lock or attached to the bag, so that indication is given by discrepancy that the lock has been operated. Figs. 1 and 4 show the application to a mail-bag fastening. A casing 1 is secured to a strap 2 provided with a buckle 3 and eyelets 4. The strap is tightened round the bag, secured by the buckle, and the end of the strap passed through a channel 4<a> at the back of the casing. A key 5 is then inserted, an extension 6 of the key passing through an eyelet 4 to retain the strap. The key is inserted through a keyhole in the cover of the casing into a rotatable sleeve 19 and is then rotated 180‹ to prevent its withdrawal, the key projection 20 engaging a slot 21 in the sleeve so that the sleeve rotates with the key. Rotation of the key can only be effected in steps involving hand-operation of a link 35 with knob 36 slidable in and out of the casing to operate a rocking pawl 33 the end 32 of which is thereby inserted in or removed from the space between adjacent teeth of a pinion 17, pawl 33 also having a recess 37 controlling movement in one direction of the end 30 of a second pawl the other end of which is adapted to engage between teeth of the pinion 17. The end 26 of a third spring-pressed pawl 22 snaps into diametricallyopposed recesses 27 in the surface of sleeve 19. Rotation of the key in one direction is thus prevented, and rotation in the other can only be effected in steps. Sleeve 19 has a tooth 18 adapted to move pinion 17 one step each time the key is brought to the locked position. The teeth of pinion 17 engage simultaneously in notches 16 formed in the inner edges of superposed and eccentrically placed rotatable annular members 12 - 15 bearing series of symbols exhibited through a window 10. The exhibited combination of symbols is automatically changed each time the key is rotated to locked position. When the key has been rotated to locked position the exhibited combination of symbols is noted at 9 on a label carried by the lock, or elsewhere. If the key be thereafter removed and replaced, the original combination of symbols is disturbed, and cannot be restored by a backward rotation of the parts. Restoration by forward rotations involves an impracticably large number of movements. Indication is thus given that the lock has been tampered with. Figs. 6 and 7 illustrate a modification adapted for railway wagons and' operating generally as described above, but in which the key-operated sleeve 19 is replaced by a spindle 19<a> rotatable by a knob 5<a> and having an end 44 adapted to engage the end 45 of a pivoted shackle 2<a> which replaces the strap 2. The symbols are exhibited through the cylindrical surfaceof the casing at 10<a> and are provided on the peripheries of superposed members 12<a> - - 15<a> operable by a mangle-pinion 17<a>. Movement of the spindle 19<a> is controlled by pawls and cams and by a member to which limited rotational movements may be given by a knob 55.