Link Latch™ Surface Head Assembly

Link Latch technology eliminates the chance of mis-latches and partial latches by connecting the latches together with links. The links have the added benefit of increasing the mechanical advantage of retraction, reducing the chance of stuck tubes. The latches have also increased in size to reduce the high wear common with older spring latch systems.

Quick Descent™ Roller Latch™ Head Assembly

The Quick Descent™ Roller Latch™ head assembly continues to build on Boart Longyear’s legacy of innovative drilling technology and offers precise compatibility with all Genuine Q™ wireline systems.

Ultra-reliable roller technology eliminates the low strength, play, and jamming associated with traditional ‘swing-out’ latch mechanisms. Roller latches detent into retracted position to eliminate latch drag for increased tripping speed, particularly in W-Wall™. Roller latches overcome the detent upon landing or alternatively can be positively driven to deployed position with fluid pressure or with drill rotation centrifugal force. Under drilling rotation, roller latches self-lock into the locking coupling integrated latch seat to drive the head assembly, eliminating adapter couplings and locking coupling tangs.

Ezy-Lock Overshot

Boart Longyear’s overshots are an integral part of the Q™ Wireline system. Once the inner-tube is full of core, the overshot is lowered to the bottom of the hole. Its heavy-duty lifting dogs grab a secure hold at the top of the inner-tube assembly.

The Ezy-Lock sleeve provides a quick, one-handed rotation of the sleeve 90° to lock the overshot lifting dogs to the spearpoint and protects against accidental release.  When combined with the use of the safety pin, the overshot minimizes the chances of accidentally dropping the inner tube assembly during handling.

The Ezy-Lock overshot features upgraded components, heavy duty lifting dogs, two compression springs for improved durability and a new re-usable press-fit pivot-pin, eliminating peening in the field for easy lifting dog maintenance.

The Ezy-Lock overshot has an upgraded threaded connection between the jar staff and overshot head for improved strength. The jar staff itself is high-strength alloy steel with an increased diameter and fail-safe stop to reduce the chance of fatigue failures.

Quick Descent™ Roller Latch™ Head Assembly


MKII™ SPEARHEAD MKII™ spearhead assembly for added strength and safety features self-lubricating nylon to reduce wear, self-centering spearpoint with multiple detent positions, and an innovative design to eliminate pinch points.

LINK LATCH™Link Latch technology eliminates partial latch and mislatches and increase retraction force reducing  stuck tubes.  The latches have also increased in size to reduce the high wear common with older spring latch systems.

LANDING INDICATION The addition of a ball and bushing provides Link Latch heads with latch indication as well as speeding up retrieval of the inner tube assembly.

DRY HOLE VALVE. The optional dry hole valve reduces time to fill the string with fluid when in lost circulation conditions.

Roller Latch head assemblies are safer and more reliable in underground applications, which allows drillers to maximize productivity.