Bi-Directional Locking Retractor

摘要

A locking retractor is disclosed, as are stretchers and cots using the retractor to secure a patient. The retractor includes structure for locking the retractor spool to prevent rotation in both directions. However, a cam is coupled to the shaft and is arranged relative to the locking structure to prevent the spool from locking during an initial portion of the spool's rotation, until a first locking point is reached. Once the first locking point has been reached, a clutch prevents the locking structure from engaging while the spool is still rotating, but the locking structure will engage to lock the spool in both directions once active rotation stops. A user-actuatable lever is provided externally that disengages the locking structure when actuated to allow the spool to extend and retract freely.

主权项

1. A locking mechanism for a retractor, comprising:
a pivot arm coupled to a lock bar, the lock bar being adapted to engage a first ratchet to prevent retractor spool rotation in a first direction; a lever arm pivotably mounted within the retractor, the lever arm including an external lever that extends outwardly from the retractor, a pawl that is adapted to engage a second ratchet to prevent retractor spool rotation in a second direction, and a portion that couples the lever arm to the pivot arm to move the pivot arm when the external lever is actuated; a cam coupled to a shaft of the retractor spool by a mechanism that causes it to rotate in a direction opposite and at a rate slower than a velocity of the retractor spool, the cam having a lobe initially positioned to support the pivot arm and prevent engagement of the lock bar with the first ratchet during an initial rotation of the retractor spool to a first lock point; and a clutch coupled to the shaft to rotate between defined rotational positions, the clutch having a shape that supports the pivot arm and prevents engagement of the lock bar with the first ratchet, and supports the pawl of the lever arm to prevent engagement with the second ratchet while the spool is rotating.