Lockset adaptable for installation at more than one backset distance

Claim 1

A lockset adaptable for installation at more than one backset distance, comprising: a bolt assembly including an elongate latch member at a first end and a separable through-slotted drawbar at a second end; a housing assembly enclosing substantially all portions of the bolt assembly except for the first end face surface of said latch member; means for extending the latch member from the housing assembly to a locked position and for retracting said latch member to an open position; and an axial cavity in the bolt first end, said axial cavity having a plurality of axially spaced locating stops defined by a pattern of longitudinal and circumferential grooves in the wall of said axial cavity; at least one radially protruding tab on said separable through-slotted drawbar, said tab being slidably engaged in said longitudinal and circumferential grooves and locatable therein between said axially spaced locating stops to define a plurality of lengths for said bolt assembly; a telescopic cylindrical portion of said housing assembly comprising an inner housing member laterally enclosing the bolt first end and an outer housing member laterally enclosing said inner member and capable of rotating and telescoping thereon in conformity with the congruent movements of said bolt assembly so as to simultaneously adjust the lengths of both the bolt assembly and the housing assembly; and a slot in said outer housing member through which a guide pin on said inner housing member protrudes and provides a visual indication of the backset distance, said slot having a configuration such that it conforms with the configuration of the rotary and telescopic motion permitted for the bolt assembly.