PNEUMATIC IMPACT MECHANISM Russian patent published in 2018 - IPC E21C37/22 E21B4/14 E21B1/30 B25D9/14 

FIELD: construction.

SUBSTANCE: invention relates to construction, mining and engineering, in particular to pneumatic impact devices. Pneumatic impact mechanism, including a cylindrical body with discharge channels and a bushing installed therein, a step anvil with the rod and the main body, a through hole and a bushing in the rod part with a channel-groove separating the cavity of the body into the idling chamber from the shank side and the annular working one, an annular flange with channels for supplying air from the network chamber, a rod rigidly fixed with respect to the annular flange, constantly located in the through hole of the anvil and interacting with the channel-groove of the bushing, a tool with a shank, an annular distribution chamber communicating on one side with the network chamber by way of the air supply channels of the annular flange and on the other side to the annular working chamber by means of an annular channel formed by the bushing of the body and the rod part of the hammer, herewith the rod is arranged able for periodic communication, depending on the position of the stepped anvil, the annular distribution chamber and the idle chamber with each other. Annular channel is made in the form of either a channel-groove or a fluke channel inclined to the longitudinal axis of the stepped anvil, the inclined planes of which are made with a curvature not lower than of the second order, with increasing cross sections extending to the end of the rod part from the side of the annular distribution chamber and decreasing cross sections, which extend to the lateral surface of the rod part from the side of the annular chamber of the working stroke with the transition to the cylindrical surface of the rod part of the anvil with the possibility of overlapping its annular channel at the end of idling and the beginning of the working stroke of the anvil.

EFFECT: air backpressure in the idling chamber and the annular chamber of the working stroke are reduced due to the regulation of the amount of air introduced into the chambers by means of varying channels-grooves or a fluke channel on the lateral surface of the rod part, which exceeds the pre-drill speed of the hammer and the energy of a single impact of the pneumatic impactor.

1 cl, 4 dwg