| 摘要 |
A mobile carriage is movable along rails by manual rotation of a handwheel. The mobile carriage comprises a visual indicator that instantly informs a person of the locked or unlocked status of the mobile carriage. The visual indicator comprises at least one ridge on the handwheel and another ridge on a locking knob. The locking knob is loosely captured between the handwheel and a hub for selective rotation relative thereto between first and second end positions. The locking knob has a cam that slides a pin within the hub between first and second positions whereat the pin disengages and engages a stationary lock plate. When the locking knob is manually rotated to the first end position thereof, the pin disengages from the lock plate to enable handwheel rotation and carriage movement. Manually rotating the locking knob to the second end position thereof causes the pin to engage the lock plate and prevent handwheel rotation and carriage movement. The ridges on the handwheel and locking knob are radially aligned when the locking knob is rotated to its first end position, indicating that the carriage is unlocked. The ridges on the handwheel and locking knob are radially misaligned when the locking knob is rotated to its second end position, indicating that the carriage is locked against movement. Closely spaced end surfaces on the two ridges are coated with a bright material to provide enhanced indication when the ridges are misaligned that the mobile carriage is locked against movement.
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