DOWNHOLE HAMMER Russian patent published in 2015 - IPC E21B4/14 

FIELD: mining.

SUBSTANCE: the downhole hammer comprises a housing containing a coupling with a main channel interconnected with the main cavity of the housing, a control sleeve with external grooves and boring, a stepped hammer with an central exhaust channel, an inlet channel on its smaller step and throttle channels at its larger step forming a network pressure chamber and an idling chamber with a housing, and with the control sleeve - a stroke chamber, a rod with larger and smaller steps, with axial and radial channels, the feeding and discharge valve which is designed as a barrel with a central hole in its bottom and is installed at larger and smaller steps of the rod with forming between them of a valve outer cavity. The feeding and discharge valve has outside a back end face platform located in the main cavity of the housing and the internal end face platform located at the barrel bottom in the valve outer cavity which is interconnected through the named radial channels of the rod with its axial channel. Between the smaller step of the rod and the named valve a circular channel is made for periodic interconnecting of the valve outer cavity with the stroke chamber during idling of the step drummer. The axial channel of the rod is blind from its front end face, and in the wall of the front part of the rod the command channels are made for periodic interconnecting of its axial channel with the stroke chamber until opening of exhaust from it by the stepped drummer during the stroke and for periodic interconnecting of the axial channel of the rod with the central exhaust channel of the step drummer through the boring made in the central exhaust channel of the step drummer.

EFFECT: improvement of performance of the feeding and discharge valve.

5 cl, 1 dwg