Tubular lock latch assembly
View Patent ↗A tubular latch assembly for a door and adapted for operation by either an “opener” such as a thumbpiece on one side and/or a knob on the other. The tubular latch comprises a central latch subassembly mounted inside the door and including a latch casing seated in the door, a bolt slidably mounted in said latch casing for extension/retraction (such as through an open face plate), a pivoting retraction lever coupled to the bolt, a spindle hub having a pair of offset cam surfaces, and a pivoting reversing lever engaged at one end with the bolt and at the other end with the second cam surface on the spindle hub for driving the bolt. The central latch subassembly allows opening by either the opener (e.g., thumbpiece) or by rotation of the knob, operation of the knob not affecting the opener and vice versa. This entirely eliminates any need for off-axis motion translation or accompanying mechanisms that are ordinarily used to adapt the axis of rotation of an opener to the orthogonal axis of rotation of a latch or spindle hub, thereby reducing the total number of parts as well as internal friction.
1. A latch assembly, comprising: a tubular latch casing for mounting within a door; a bolt mounted in said latch casing for extension and retraction along a longitudinal axis to thereby latch said door along said longitudinal axis; a retraction lever mounted in said latch casing and coupled to the bolt and disposed for pivoting about a first pivot axis perpendicular to the longitudinal axis to retract the bolt; an operator for mounting to a face of the door and disposed for pivoting about a second pivot axis parallel to the longitudinal axis, the retraction lever pivoting about the first pivot axis in response to the operator pivoting about the second pivot axis; a spindle hub mounted in the latch casing, the spindle hub engaging the retraction lever to retract the bolt upon rotation of the spindle hub in a first direction; a reversing lever mounted in the latch casing, the spindle hub engaging the retraction lever to retract the bolt via the reversing lever upon rotation of the spindle hub in an opposite direction.
2. The latch assembly of claim 1 , wherein the spindle hub includes a first cam surface and a second cam surface, the first cam surface engaging the retraction lever to retract the bolt and the second cam surface engaging the retraction lever via the reversing lever to retract the bolt.
3. A latch assembly, comprising: a tubular latch casing for mounting within a door having a first axis, a second axis, and a third axis, the first axis being perpendicular to the second axis and the third axis; a bolt mounted in said latch casing for extension and retraction along the first axis to thereby latch said door along said longitudinal axis; a retraction lever mounted in said latch casing and coupled to the bolt and pivoting about the second axis for retracting the bolt; a reversing lever mounted in said latch casing and pivoting about the third axis and engaging the retraction lever to retract the bolt; and a spindle hub mounted within the latch casing and operated by an operator, said spindle hub having a first cam surface and a second cam surface, the retracting lever engaged by the first cam surface and pivoting about the second axis in response to rotation of the spindle hub in a first direction and the reversing lever engaged by the second cam surface and pivoting about the third axis in response to rotation of the spindle hub on a second direction.
4. The latch assembly of claim 3 wherein said operator is mounted to a face of the door and configured to pivot about a fourth axis parallel to the first axis, the retracting lever engaged by the operator and pivoting about the second axis in response to the pivoting of the operator about said fourth axis.
5. A latch assembly, comprising: a tubular latch casing for mounting within a door; a bolt mounted in said latch casing for extension and retraction along a first axis to thereby latch said door along said longitudinal axis; a retraction lever mounted in said latch casing; a reversing lever mounted in said latch casing for retracting the bolt by engaging the retraction lever; a spindle hub rotatably mounted in said latch casing and including a first cam surface for engaging the retraction lever and a second cam surface for engaging the reversing lever; a first operator for mounting to a face of the door and disposed for pivoting about a second axis perpendicular to the first axis, said first operator coupled to, and coaxial with the spindle hub, the retraction lever engaged by the first operator via the spindle hub and retracting the bolt in response to the first operator pivoting about the second axis; and a second operator for mounting to another face of the door and disposed for pivoting about a third axis parallel to the first axis, the retraction lever engaged by the second operator and retracting the bolt in response to the second operator pivoting about the third axis.
6. The latch assembly of claim 5 wherein the first cam surface engages the retraction lever in response to rotation of the first operator in a first direction and the second cam surface engages the reversing lever in response to rotation of the first operator in a second direction, thereby retracting the bolt.
7. The latch assembly of claim 5 wherein the retraction lever is pivotable about a first pivot axis perpendicular to the first axis.
8. The latch assembly of claim 5 wherein the reversing lever is pivotable about a second pivot axis perpendicular to the first axis.
9. The latch assembly of claim 5 wherein the bolt further comprises a tail portion having an elongated slot formed at an angle to the first axis and the retraction lever further comprises a pin disposed in the slot such that rotation of the retraction lever laterally translates the pin in the slot causing the bolt to retract.
10. The latch assembly of claim 5 wherein the retraction lever is mounted at a first end of said casing extending toward and engaging a distal end of the bolt mounted at an opposite end of the casing, the spindle hub is mounted between the retraction lever mounting point and the distal end of the bolt and the reversing lever is mounted between the spindle hub and the bolt.
11. A method of retracting a latch disposed in a latch casing comprising the steps of: providing a tubular latch casing for mounting within a door; providing a bolt mounted in said latch casing for extension and retraction along a longitudinal axis to thereby latch said door along said longitudinal axis; providing a retraction lever pivotally mounted in the latch casing for pivoting about a first axis perpendicular to the longitudinal axis to retract the bolt; providing a reversing lever pivotally mounted in the latch casing, providing a spindle hub within the latch casing including a first cam surface for engaging the retraction lever to retract the bolt and a second cam surface for engaging the retraction lever via the reversing lever to retract the bolt; providing a first operator mounted to a face of the door and coupled to the spindle hub, the spindle hub engaging the retraction lever in response to rotation of the first operator in a first direction and the spindle hub engaging the retraction lever via the reversing lever in response to rotation of the first operator in a second direction.
12. The method of claim 11 further including the step of providing a second operator for mounting to a face of the door and pivotable about a second pivot axis parallel to the longitudinal axis of the bolt, the retraction lever retracting the bolt in response to pivotal movement of the second operator.