Detaching Hooks

The detaching hook is incorporated in the suspension gear of drum winding systems to detach the hoist rope from the conveyance in an overwind situation. Once the hoist rope has been detached, the detaching hook is caught in a catchplate system located in the headframe.

The detaching hook is comprised of a pair of pivoting inner plates which are able to pivot within two outer plates when they strike a catchplate. Detachment is initiated when the detaching hook is pulled through the catchplate which is located in the headframe below the head sheave. When the inner plates contact the catchplate, they are forced to “scissor” open. After opening, the inner plates are locked in the detached position which releases the hoist rope. The geometry of the detaching hook does not allow for it to fall back through the catchplate once it has scissored open. Thus, the conveyance will remain suspended from the catchplate.

All Reliance Barker Davies detaching hooks contain a Mancane Latch which was developed in order to create a second safety mechanism to prevent unintentional detaching.

Design features also embody the following:

1. Automatic locking in the detached position.
2. Simplicity of resetting and release from the catch plate.
3. Operating plates protected against inadvertent detachment by accidental side blows from falling debris
4. Outer plates and pivot (or hinge) pin not subject to hoisting loads.
5. Oversize lower pins to reduce stress at drop back of suspended load at overwind.