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The door latch construction is of the usual type wherein a bolt is reciprocal in a casing between extended and projecting positions with latch operating means forwardly operably connected to the bolt for causing such motion. In such latch construction, the longitudinal distance between the forward e

The door latch construction is of the usual type wherein a bolt is reciprocal in a casing between extended and projecting positions with latch operating means forwardly operably connected to the bolt for causing such motion. In such latch construction, the longitudinal distance between the forward extremity of the casing and the operator axis constitutes backset. According to the present invention, the casing and bolt are each comprised of relatively longitudinally movable forward and rearward parts with a substantially helical slot on one of the parts and engaged by a projection on the other of the parts in each case. The slot and projection of each provides helical longitudinal movement for each of the determined same amount between a forward backset and a rearward backset, with interconnection means between certain of the bolt parts and certain of the casing parts for requiring substantially the same helical longitudinal movement of one upon such movement of the other. Otherwise, the bolt is reciprocal relative to the casing in either of the forward and rearward backsets. The bolt and casing interconnection means may be common formation permitting longitudinal movement but not permitting relative rotational movement. Furthermore, the casing helical slot may be formed at either end to retard movement over the bolt helical slot, resiliently urged stops may be installed to stop helical slot movement at either end of movement, and anti-adjustment projections may be installed only permitting helical slot movement when the bolt is in extended position.

대표청구항 ▼

In a latch construction for mounting in doors and the like of a type having a bolt longitudinally reciprocal in a normally stationary casing between a forward extended position projecting from the casing and a rearward retracted position substantially fully within the casing, latch operating means f

In a latch construction for mounting in doors and the like of a type having a bolt longitudinally reciprocal in a normally stationary casing between a forward extended position projecting from the casing and a rearward retracted position substantially fully within the casing, latch operating means forwardly operably connected to said bolt and rearwardly operably connected to an operator thereof, said operating means operator being movable about a transverse axis actuating said actuating means to reciprocate said bolt, longitudinal distance between forward extremity of said casing and said operator axis constituting backset; the improvements including: said bolt and said casing each being comprised of relatively longitudinally movable forward and rearward parts; a substantially helical slot on one of said parts engaged by a projection on the other of said parts of each of said bolt and casing, said slot and projection providing helical longitudinal movement for each of a determined same amount between a forward backset and a rearward backset; interconnection means between certain of said bolt parts and certain of said casing parts for requiring substantially the same helical longitudinal movement of one upon such movement of the other; said bolt being reciprocal relative to said casing in either of said forward and rearward backsets.