Fordia offers a selection of locking couplings, the part of the core barrel that is found on the upper part of the outer tube. The locking coupling adapts the core barrel outer tube to the drill rods and locks the head assembly to the outer tube so that the head assembly turns with the outer tube when drilling. It also stabilizes the upper section of the core barrel, minimizing hole deviation and some types can protect the hole diameter if the reaming shell loses its gauge.
Knowledge of your ground conditions will help determine which type of locking coupling will provide the best results.
This conventional coupling comes in full hole size and comes equipped with tungsten carbide pads for better stabilization. A good choice for ground where not much deviation is expected.
Also known as a full-hole coupling, the hexagonal coupling has a circumference that is made of 4-6 sections providing good stabilization. The hexagonal locking coupling is used in conjunction with a full hole outer tube to control bore hole deviation by stabilizing the core barrel.
This locking coupling comes with a more resistant matrix pad on the body that is embedded with tungsten carbide grit as well as tungsten carbide pads and provides even better stabilization of the core barrel.