SUB LOCKING ASSEMBLY (EMBODIMENTS) Russian patent published in 2018 - IPC E21B4/02 E21B17/06 

FIELD: soil or rock drilling.

SUBSTANCE: group of inventions refers to drilling equipment. Locking mechanism of the sub is fixed between the supports and contains a tubular thrust, in the cavity of which there is an annular insert with thrust grooves. In each groove there is a rotatable spring-loaded lock pawl. Slots are formed on the outer surface of the shaft. Rings, in the holes of which the ends of the pivot axis of the pawls are positioned, are connected to the tubular thrust and on both sides adjoin the ends of the annular insert, which is made with slots on its inner surface sitting on the shaft slots. Upper conical connection of the body is made as an outwardly widening conical trumpet with a thread on the inner surface. External thread is made on the outer surface of the lower conical connection of the body. As per the first embodiment, the bottom surface of each pawl is made of two parts, one of which is shorter than the other one, thus forming a vertex facing outward. In the working position, the pawl is supported by its long surface on the surface of the groove of the annular insert. In the non-operating position, the pawl is supported by the short surface on the surface of the groove and in this pawl position a continuous annular gap is formed between its upper surface and the surface of the annular insert. As per the second embodiment, the bottom surface of each pawl is made flat and in the working position it rests with its lower flat surface on the surface of the groove of the annular insert. In the non-operating position, a continuous annular gap is formed between its lower flat surface and the surface of the annular insert, and the depth of the groove of the tubular thrust is greater than the thickness of the pawl disposed therein.

EFFECT: increase in the life of the sub locking assembly is ensured.

6 cl, 22 dwg