IMMERSIBLE HYDRAULIC HAMMER Russian patent published in 2007 - IPC E21B4/14 

FIELD: geological prospecting, hydrogeology and mining, namely drilling equipment, particularly submersible drilling rigs with fluid power drives for percussive-rotary well drilling.

SUBSTANCE: hydraulic hammer comprises sub, sleeve, stepped striker, distribution system with stepped supply-and-discharge valve installed on sub stem. The striker has head, which separates sleeve interior into forward and reverse stroke chambers. The supply-and-discharge valve and sleeve define end supply slot. The supply-and-discharge valve and sub stem define end discharge slot, which communicates forward stroke chamber with discharge path through longitudinal channel. Hydraulic hammer also has cavity located behind valve and orifices located at the cavity, axial channel in the stem and anvil having common discharge path with striker. Spring-loaded bush is arranged in sub stem provided with throttling orifices located near the cavity, which may selectively close radial windows created in upper sub stem part. The windows communicate forward stroke chamber with discharge path through axial channel of the stem.

EFFECT: increased operational efficiency due to increased power owing to striker impact frequency enhancement.

2 dwg