Interlocking kelly bar

1.applied to the hard and soft layer 2.high efficiecy 3.durable steel material for longtime use

      The external key of the mechanical interlocking kelly bar usually hao three or six keys.

There are three large groups or N groups pressure concave parts in the external key, three or six wear-resistant keys in the internal keys. The length of the bar is less than the length of large concave tine of the external key. When the driving force rotates, the internal key of the driving set or the internal key of kelly bar rotate to the large concave tine of the external key, and formed a Kai-type pressuring point. Driving force head send pressure to the drill head, then forms a mechanical locking. A full rotary drill head must be rotary in the opposite direction to unlock, then smoothing reversal upgrade.

         This kelly bar is used for hard or soft layer to drill, which hao better transmission pressure. This kelly bar need to move driving force head up and down. When drilling in hard layer,. It transfer pressure after find the large concave meshing tine in the external. At resent,the mechanical pressuring kelly bar is usually combined with three sections, four sections and five sections, with the drilling depth in the range of 36-80 meters.

Interlocking kelly bar