Door latch assembly with backset adjustment

A latch assembly having a backset adjustment for mounting within a bore extending in from a side edge of a door and operable by a rotatable operator on a side of the door disposed for rotation about a rotational axis, the latch assembly comprising:

• a casing assembly for mounting in the bore of a door, the casing assembly having a bolt assembly longitudinally reciprocal therein between a retracted position and an extended position;
• the bolt assembly including a bolt with a cylindrical aperture therein, the bolt rotatable and reciprocal relative to a non-rotational bolt adjuster and having a sliding fit thereon, an internal groove extending for at least 180.degree. within the cylindrical aperture of the bolt, the bolt adjuster having an external projection engageable in the groove of the bolt;
• a bolt extension connected at one end with the bolt adjuster and reciprocal with the bolt assembly;
• a cam actuating means connected to the other end of the bolt extension, the cam actuating means having a pivot connection coaxial with the rotational axis of the rotatable operator;
• the casing assembly including a rear casing with a back portion containing retaining means for rotatably constraining the cam actuating means, the back portion of the rear casing integral with a front hollow cylindrical portion with a non-helical substantially serpentine shaped slot extending about a portion of the circumference thereof;
• a forward hollow cylindrical casing rotatable and slidable about the front portion of the rear casing, the forward casing having an internal protrusion engageable in the non-helical substantially serpentine shaped slot of the front portion of the rear casing;
• and
• the forward casing engaging the bolt with the forward casing and bolt simultaneously rotatable through significantly different patterns of movement at least 180.degree. to change the backset.