HASP DEAD-LOCK Russian patent published in 1997 - IPC

FIELD: locking devices; applicable in doors of passenger cars, electric train cars and cars of diesel trains. SUBSTANCE: hasp dead-lock has one cylindrical compression spring easily replaced without dismantling and disassembly of lock, L-shaped pull rod for changing direction of force of cylindrical spring. Lock has supporting pivot with hole and stop, guide clamp with projections, and curved lever with hole. L-shaped pull rod with threaded end comes out of through pivot hole, curved lever and guide clamp to enter the hole of collar. Cylindrical spring is fitted on threaded end of L-shaped pull rod and secured with thrust nut. The other end of spring thrusts curved lever to transmit force to bar which fixes bush of the cross bar and cross bar in positions locked and unlocked. Bent end of L-shaped pull rod thrusts the shoulder of catch bush which moves catch free from spring load to the locked or unlocked position. Spring does not act on catch, there is no force friction between catch bush and catch that excludes wedging of closed door by catch under the action of compressed spring. To replace spring, the thrust nut is unscrewed, spring is replaced with a spare one and secured by thrust nut. There is no need to remove handles from the door, facing, or disassemble the lock for spring replacement. EFFECT: simplified repair, higher reliability, safety of lock of doors of passenger car and cars of electric trains and diesel trains, excluded hazardous wedging of closed door and application of drifts, chisels and hammers which may damage door during replacement of springs, speeded up replacement of lock spring (2 min by one fitter as compared with the known locks needed for the spring replacement two fitters for 52 min each).