Mortise lock assembly

1. A mortise lockset comprising:

a mortise lockset case configured for insertion into a door mortise;

a latchbolt enclosed at least partially within the mortise lockset case and guided for movement between positions in which the latchbolt extends out of the case and in which the latchbolt is substantially retracted within the case;

a latch retractor, enclosed within the mortise lockset case, operable to retract the latchbolt;

a hub assembly, enclosed within the mortise lockset case, operable to drive the latch retractor into a latchbolt-retracting position;

first and second handle-operated spindles each configured for selective operative engagement with the hub assembly;

a lock-handing selector configured to enable a selection of one of the first and second handle-operated spindles to operate the hub assembly to drive the latch retractor into the latchbolt-retracting position;

wherein the lock-handing selector is operable to be changed from a first configuration operatively enabling the first handle-operated spindle to retract the latchbolt to a second configuration, distinct from the first configuration, enabling the second handle-operated spindle to retract the latchbolt, and vice versa, without opening the mortise lockset case; and

a faceplate-accessible access control link assembly enabling a user to manually switch between access-enabling and access-denying configurations that respectively enable and disable an opposite one of the first and second handle-operated spindles to operate the hub assembly to drive the latch retractor into the latchbolt-retracting position;

wherein the first and second door handle-operated spindles are permanently rotationally decoupled from each other so that operative rotation of either handle-operated spindle does not rotate the opposite handle-operated spindle, even when the faceplate-accessible access control link assembly is in the access-enabling configuration so that both handle-operated spindles are configured for operative movement of the hub assembly.

2. The mortise lockset of claim 1 , wherein the lock-handing selector is operable to be changed from the first configuration to the second configuration, and vice-versa, without removing the mortise lockset from a door mortise in which the mortise lockset is installed.

3. The mortise lockset of claim 2 , wherein the lock-handing selector is mounted on and in surface contact with one of the two selected handle-operated spindle.

4. The mortise lockset of claim 3 , wherein the lock-handing selector is mounted on the selected handle-operated spindle for rotation therewith.

5. The mortise lockset of claim 1 , further comprising:

a clutch, operated by the faceplate-accessible access control link assembly, enclosed within the mortise lockset case and operative between engaged and disengaged positions in accordance with a user-selectable setting; and

wherein the clutch, when engaged, rotationally interlocks a non-selected one of the first and second handle-operated spindles, opposite the selected handle-operated spindle, with a latch-retracting actuating portion of the hub assembly, thereby operatively enabling the non-selected spindle to retract the latchbolt.

6. The mortise lockset of claim 5 , wherein the hub assembly comprises a pair of coaxial cams, each operable to rotate, independently of the other, both counterclockwise and clockwise with respect to a rotationally intermediate position;

the rotationally intermediate position does not drive the latch retractor into a latchbolt-retracting position; and

rotation of any one of the coaxial cams in either the clockwise direction or the counterclockwise directions from the rotationally intermediate position operates to drive the latch retractor into a latchbolt-retracting position.

7. The mortise lockset of claim 5 , wherein the hub assembly comprises a spindle hub subassembly selectively coupled for cooperative rotation with a coaxial cam subassembly.

8. The mortise lockset of claim 7 , wherein the spindle hub subassembly is nested for rotation within the coaxial cam subassembly.

9. The mortise lockset of claim 7 , wherein the spindle hub subassembly comprises a pair of independently rotatable spindle hubs.

10. The mortise lockset of claim 7 , wherein the coaxial cam subassembly comprises two independently rotatable operating cams.

11. The mortise lockset of claim 1 , wherein the two independently rotatable operating cams of the coaxial cam subassembly each cam the latch retractor, which is mounted for pivotal rotation about an axis eccentric to that of the hub assembly.

12. A clutching mortise lockset comprising:

a mortise lockset case configured for insertion into a door mortise;

a latchbolt enclosed at least partially within the mortise lockset case and guided for movement between positions in which the latchbolt extends out of the case and in which the latchbolt is substantially retracted within the case;

a latch retractor, enclosed within the mortise lockset case, operable to retract the latchbolt;

a hub assembly comprising a pair of coaxial cams, each operable to rotate, independently of the other, both counterclockwise and clockwise with respect to a rotationally intermediate position, in order to drive the latch retractor into a latchbolt-retracting position;

first and second handle-operated spindles each configured for selective operative engagement with the hub assembly;

a clutch enclosed within the mortise lockset case operative between engaged and disengaged positions;

a faceplate-accessible clutchworks operating the clutch and enabling a user to switch between access-enabling and access-denying configurations that respectively enable and disable an outside handle-operated spindle to operate the hub assembly to drive the latch retractor into the latchbolt-retracting position;

wherein the clutch, when engaged, rotationally interlocks a non-selected one of the first and second handle-operated spindles, opposite the selected handle-operated spindle, with a latch-retracting actuating portion of the hub assembly, thereby operatively enabling the non-selected spindle to retract the latchbolt; and

wherein the clutch, when disengaged, rotationally decouples the non-selected spindle from the latch-retracting actuating portion of the hub assembly, thereby allowing the non-selected spindle to turn without retracting the latchbolt.

13. The clutching mortise lockset of claim 12 , further comprising divaricate cam projections on each of the coaxial cams adapted, when rotated in both clockwise and counterclockwise directions, to drive the latch retractor into a latchbolt-retracting position.

14. The clutching mortise lockset of claim 12 , wherein the first and second door handle-operated spindles are permanently rotationally decoupled from each other so that operative rotation of either handle-operated spindle does not rotate the opposite handle-operated spindle, even when the clutchworks is in the access-enabling configuration configuring the outside handle-operated spindle for operative movement of the hub assembly.

15. The clutching mortise lockset of claim 12 , wherein the faceplate-accessible clutchworks comprises a user-actuated rocker with a clutch dog to enable the user to selectively engage and disengage the clutch.

16. The clutching mortise lockset of claim 12 , wherein the faceplate-accessible clutchworks comprises a pair of buttons recessed in a faceplate of the mortise lockset.

17. The clutching mortise lockset of claim 12 , further comprising a spring-biased escapement mechanism, wherein the escapement mechanism:

enables a user to toggle the faceplate-accessible clutchworks into the clutch-engagement position even when a corresponding portion of the hub assembly is rotationally misaligned with respect to the clutch, the misalignment preventing the clutch from operatively engaging the corresponding portion of the hub assembly; and

spring biases the user-actuated clutch into operative clutching engagement with the corresponding portion of the hub assembly after that portion rotates into a rotationally aligned position.

18. The clutching mortise lockset of claim 12 , wherein the faceplate-accessible clutchworks comprises a pivotally-mounted lever arm operative to move a rotationally interlocking clutch dog between engaged and disengaged positions with respect to the latch-retracting portion of the hub assembly.

19. The clutching mortise lockset of claim 18 , wherein the faceplate-accessible clutchworks further comprises:

a pair of interconnected slides operative to urge the lever arm up or down; and a leaf spring mounted on one of the slides that is operative, in a spring-enabling position of the slide, to bias the lever arm toward a clutch-engaging position, and that is inoperative, in a spring-disabling position of the slide, to bias the lever arm toward a clutch-engaging position.