HYDRAULIC ANCHOR Russian patent published in 2013 - IPC E21B23/06 

FIELD: mining.

SUBSTANCE: anchor's part of rod has upper and lower bosses that are pistons interacting with internal walls of upper and lower casings correspondingly. There are chambers below the pistons that interact with inter-tube space through radial through-holes in the rod. Above the pistons there are chambers that are connected with annulus space through radial through-holes in upper and lower casings. The lower casing has through grooves for retainers mounted in the casing, on the slope surface of which there are grooves of dovetail type, in which slips move. The lower end of the cone interacts with the spring mounted in the shield of HA. There are grooves on the rod upper part and top casing with key mounted into them. On the cone surface there are radially located slots interacting with corresponding grooves of the lower casing.

EFFECT: increase of hydraulic anchor fixing reliability, provision of guaranteed return of slips into transportation position at loosening, provision of possibility to transmit revolution from pipe string through hydraulic anchor to downhole equipment located below.

6 cl, 2 dwg