GB189720901A - Alarm Padlock. - Google Patents

Abstract

20,901. Case, E. N. Sept. 11. Padlocks.-A padlock for doors, trunks, bicycles, &c. is arranged to explode a cartridge when the shackle is pulled to force the lock, or when a false key is used. The shackle A is swivel-jointed at I to a rod C carrying a spring C' and a spring- returned pawl i. A hollow shaft a is mounted in line with the keyhole, and has a slot to receive the bit of a pin key. The shaft carries a cam w, with a stump. s<2>, engaging levers b, b<2>. On rotating the shaft by the proper key, the cam to disengages the pawl i from a crank lever n and allows the shackle to be pulled out until the short end clears the casing S, when it can be rotated. Its linear motion is limited by a stop k and guide r, and its rotary motion by a stop pin l. The firing-case f is secured by a bayonet-joint in a recess b<21>, in which the cartridge h has been previously inserted. The case is turned or withdrawn by a knob on the end of the key, fitting a slot l<2> in the end of the case. The firing-pin x is operated by a springs, which is compressed when the case is inserted by a spring trigger m engaging the lip of an aperture in the side of the recess b<21>. The trigger is released and the cartridge exploded, by excessive movement of either of the locking-levers by a false key, or by pulling the shackle, the latter act causing the pawl i to operate the crank lever n, and consequently a second lever o, bearing on the trigger. A stop s limits the motion of the pawl i and also of the lever n, preventing the lock from being opened by pulling the shackle. The pull necessary to explode the cartridge depends on the strength of the spring C<2> controlling the lever n. The firing-case is locked in position, when the lock is fastened, by a spring nose g, forced into engagement with it by a spring plunger v, depressed by closing the shackle.