Abstract: A linkage anti-theft lock head comprises a lock tube (16), a lock core (2), a brake bar (19), a front tumbler (6) with its return spring (20), a rear tumbler (9) with its return spring (20) and a key (1). Clearance fits are provided between the front tumbler (6) and the rear tumbler (9) with the holes (26) distributed axially on the lock core (2). The brake bar (19) is mounted axially along the lock core (2). Brake teeth of the brake bar (19) engage with the teeth grooves of the front tumbler (6) and the rear tumbler (9). Said engagement is a linkage engagement. A brake groove (17) is set on the lock tube (16) to match with the brake bar (19). The tumblers, the brake bar (19) and the lock core (2) constitute a cant device, wherein the front tumbler (6) and the rear tumbler (9) act as moving cams set oppositely, the brake bar (19) acts as a driven member and the lock core (2) acts as a rack.

Abstract: An anti-theft lock with plate tumblers includes two axial grooves (18) which are disposed at diametrically opposite locations on an inner wall of the lock (1) and an annular groove (10) which has a rectangular cross section and is provided on the inner wall of the lock (1) adjacent an end proximal to a key slot (21). A round controlling plate (8), of which the diameter is same as that of the core (2), is disposed between the lock cover (9) and the lock core (2). A key slot (15), which is narrower than the key slot (21) in the lock core (2), is provided in the round controlling plate (8). Two V-shaped grooves (16) are provided on the inner sidewall of the round controlling plate (8) and correspond to two ends of the key slot (15). Two swallowtail grooves (20), in which a brake shaft (4) is mounted, are provided on the lock core (2), Multiple tooth grooves (17), which are engaged with the brake position teeth (14), are disposed on the outer walls of the two ends of the plate tumblers (5).

Abstract: An anti-theft lock with plate tumblers includes two axial grooves (18) which are disposed at diametrically opposite locations on an inner wall of the lock (1) and an annular groove (10) which has a rectangular cross section and is provided on the inner wall of the lock (1) adjacent an end proximal to a key slot (21). A round controlling plate (8), of which the diameter is same as that of the core (2), is disposed between the lock cover (9) and the lock core (2). A key slot (15), which is narrower than the key slot (21) in the lock core (2), is provided in the round controlling plate (8). Two V-shaped grooves (16) are provided on the inner sidewall of the round controlling plate (8) and correspond to two ends of the key slot (15). Two swallowtail grooves (20), in which a brake shaft (4) is mounted, are provided on the lock core (2), Multiple tooth grooves (17), which are engaged with the brake position teeth (14), are disposed on the outer walls of the two ends of the plate tumblers (5).