Clevis sensing lock

1. A latch mechanism comprising,

a hook-handle assembly including a hook member, a handle, and a linkage arrangement coupled between the hook member and handle, the handle adapted to control motion of the hook member when unlocking and locking the latch mechanism;

a clevis having a hook-end receiver and a coupler portion spaced apart from the hook-end receiver to at least partially define an opening therebetween, the hook-end receiver configured to engage with a hook end of the hook member as the handle moves from an open position toward a closed position;

a clevis-sensing lock carried on the handle, the clevis-sensing lock including a block coupled to the handle, a lock member received in the block, a tumbler arrangement coupled between the lock member and the block and configured to control movement of the lock member relative to the block, and an interference member coupled to the lock member, the interference member configured to pass through the opening of the clevis in an unlocked position and engage an underside of the clevis to block movement of the handle relative to the clevis in a locked position, the lock member configured to control movement of the interference member; and

a device having a head, a shaft coupled to the head, and a protrusion extending outward from the shaft, the shaft configured to be received in the lock member to engage with the tumbler arrangement to allow movement of the lock member, the protrusion configured to engage with the handle to trap the shaft within the lock member when the lock member is in the unlocked position, and the head configured to extend away from the handle to provide an indication of an unlocked state of the clevis-sensing lock;

wherein the clevis is configured to receive at least the interference member carried on the clevis-sensing lock and to allow movement of the lock member to the locked position when the interference member is received through the clevis.

2. The latch mechanism of claim 1 , wherein the tumbler arrangement includes a detent spring, a detent pin positioned between the lock member and the detent spring, and a tumbler pin positioned between the detent pin and the lock member, wherein the detent spring is configured to bias the detent pin toward the tumbler pin, and wherein the detent pin is configured to engage with the block and the lock member to restrict movement of the lock member when an interface between the detent pin and the tumbler pin is misaligned from a lower surface of the lock member.

3. The latch mechanism of claim 2 , wherein the device is further configured to engage with the tumbler pin and to align the interface between the detent pin and the tumbler pin with the lower surface of the lock member when the device is received in the lock member.

4. The latch mechanism of claim 1 , wherein the lock member is formed to include an annular groove and an axial slot extending toward the interference member from the annular groove.

5. The latch mechanism of claim 4 , further comprising a cross-pin configured to slide in the annular groove and axial slot of the lock member to control movement of the lock member.

6. The latch mechanism of claim 5 , wherein the clevis further includes a fin extending from an upper surface of the clevis opposite the underside, and wherein the fin is configured to move the cross-pin out of the axial slot and into the annular groove to allow movement of the lock member as the handle moves toward the closed position.

7. The latch mechanism of claim 1 , wherein the lock member is formed to include a groove extending at least partially around a circumference of the lock member, and wherein a fastener extends through the handle and the block to couple the clevis-sensing lock to the handle and is received in the groove of the lock member.

8. The latch mechanism of claim 7 , wherein the groove of the lock member is configured to limit movement of the lock member relative to the block.

9. The latch mechanism of claim 1 , further comprising an indicator coupled to the device and configured to enhance the visibility of the device and provide a signal to a user that the clevis-sensing lock is in the unlocked position.

10. A method of operating a latch mechanism, the method comprising,

inserting a device into a clevis-sensing lock through an aperture formed in a handle of a hook-handle assembly;

moving the device to disengage an interference member of the clevis-sensing lock from a clevis;

moving the handle relative to the clevis to disengage a fin of the clevis from the clevis-sensing lock to engage a cross-pin of the clevis-sensing lock with a lock member of the clevis-sensing lock to block movement of the device such that the device is trapped in the clevis-sensing lock; and

moving the handle to disengage a hook member of the hook-handle assembly from the clevis.

11. The method of claim 10 , further comprising,

moving the handle toward the clevis to engage the hook member with the clevis;

moving the handle toward the clevis to engage the fin with the clevis-sensing lock to disengage the cross-pin from the lock member to allow movement of the device;

moving the device such that the interference member is engaged with an underside of the clevis; and

removing the device from the clevis sensing lock.

12. The method of claim 11 , wherein inserting the device comprises extending a shaft of the device into the lock member and engaging a tumbler arrangement to allow movement of the interference member.

13. The method of claim 11 , wherein removing the device comprises removing the shaft from the lock member and disengaging the tumbler arrangement to block movement of the interference member.