Abstract: The machine has a braking arrangement for retaining it against rearward motion and rotation and includes a housing accommodating therein a hammer reciprocable in operation of the machine and adapted to strike the head part of the housing, the latter having a drilling tool rigidly connected thereto. The tail part of the housing supports a sleeve rigidly connected with the braking arrangement. The housing and the sleeve are connected so that the housing is rotatable and axially displaceable relative to the sleeve. The drilling tool rotating mechanism is positioned intermediate the sleeve and the housing and includes a helicoidal couple made up by a helicoidally threaded rod rigidly secured to the housing and a nut, the mechanism further including a freewheeling clutch of which the movable cage is made integral with the nut.

Abstract: A percussive machine having an impact mechanism accommodated to a housing with a hammer piston imparting blows to a rock-destroying member. There is provided an air-supply duct for supplying compressed air to the impact mechanism and to the hole face. In order to prevent the machine from moving away from the hole face during the operation, the housing is provided with an elastic tubular member having a space in constant communication with the air supply duct.