Dependable two piece lifting and lowering dogs for AW drill rods

AWHD - The holding (or bottom dogs) drop onto the top of an AW casing held by a set screw
            With the lever released the rods are clamped tightly in the bottom dogs
            When the upper portion is pulling the rods up the bottom dogs open releasing the rods
            When lowering rods depressing the foot lever opens the bottom dogs releasing the drill string
            Releasing the foot lever closes the bottom dogs clamping the rods 

AWPD - The pulling (or upper dogs) slide easily up and down the AW drill rod.
            A cable is attached to the upper dogs and runs over the sheave to the winch
            When the cable is released the upper dogs drop down the rods to the bottom dogs
            When the cable is tightened the upper dogs grip the rod lifting the drill string
             Upper movement of the drill string opens the bottom dogs allowing the rods to lift.
             When the cable is slackened at the top of the pull the bottom dogs grip the rods once again.
             Once the lower dogs engage the upper dogs release and drop down to the bottom dogs.
             The cycle is repeated to pull the entire drill string.

• Capacity AW Aluminum Rods 300 feet (100 meters)