Abstract: The invention relates to a hydraulic rotary percussive device of the drill type, intended for drilling boreholes, comprising: a striking mechanism equipped with a piston which is able to move translationally along a striking axis and is intended to strike a tool; a hydraulic motor which rotates the tool about an axis of rotation, the axis of rotation of the motor being substantially coincident with the striking axis of the piston, wherein it comprises a support-forming casing, the striking mechanism being hydraulic and having a longitudinal body rotatably mounted in the casing about the axis of the body, the body being rotated directly by the motor and coupled to the tool.

Abstract: A device for supplying hydraulic power to a rotary apparatus for percussive drilling (2) whereof the tool (3) is driven in one direction or another and subjected to the action of an impact device (6) acting independently of the rotation, of a hydraulic device (9) with forward movement enabling the tool to generate a pressure force on the ground, and optionally of a suction device (14) for the drilling dusts, driven by a hydraulic motor, the various hydraulic actuating elements being driven from a hydraulic liquid source under pressure through a hydraulic flow divider (16), a set of distributors (17, 18, 19, 20) and an assembly of branch pipes outside the apparatus, such as hose pipes. The device includes a branch pipe external to the apparatus (24) for communicating the return branch pipe (22) of the hydraulic device (4) driving the tool in rotation and the supply line (23) of the impact device (6), to add to the supply rate of the impact device the return flow rate of the rotation driving device.

Abstract: The invention concerns an hydraulically powered mechanism of the kind having a piston assembly which is arranged to be driven by hydraulic fluid acting on it in a working zone and an item of equipment which is to be driven by the piston assembly. The piston assembly presents a face which acts at an interface against a complemental face on the item of equipment. A fluid passage is provided to supply hydraulic fluid from the working zone to the interface for lubrication purposes. In a specific application of the invention it may be used in the rotary indexing mechanism of an hydraulically powered, typically a water-powered, rockdrill.

Abstract: The rock drill (9) includes a reversible rotary motor (10) and a percussion unit (11) with a percussion valve (17). Rotary unit and Percussion unit (11) are operated via separate valves (39, 46) in a control unit (34). The percussion frequency of the percussion unit (11) is coupled to the rotation rate of the rotary motor (10) in such a way that the percussion unit (11) stops automatically when the rotary motor (10) comes to a standstill. The coupling is achieved by employing a fluid driven assembly without a mechanical clutch between the rotary motor (10) and the percussion valve (17). When disassembling the drill rods a jammed thread can be shaken loose with the percussion unit (11) be manually bypassing the fluid coupling. The same is also possible in case the drill rods becomes jammed in the drill bore. With the described embodiment a simple, space-saving and cost-effective construction is achieved which is versatile in application.

Abstract: A hydraulic drilling machine has a drilling tool connected to a hydraulic motor, a hydraulic percussive mechanism connected through a rotatable fluid distributor to pressure and discharge lines, and a flow governor made up of a non-return valve and a flow throttling valve connected in parallel. The inlet of the flow governor is connected to a discharge line of the hydraulic motor, whereas its outlet is connected to a discharge line of the hydraulic percussive mechanism in the form of a hydraulic reaction turbine.

Abstract: A hydraulic drilling apparatus, especially a rock drill comprising a body, a cylinder in the body and a percussion piston reciprocating in the cylinder. A tool is connected to the body and a motor is provided for rotating the tool. A control valve is also provided for the percussion power. A control valve is also provided for regulating the motor speed. Both of these control valves are operated independently by one lever. A hydraulically operated flushing valve is also provided. A hydraulic pump and hydraulic channels coact to form a percussion circuit and a rotation circuit is parallelly coupled with the percussion circuit in relation to the hydraulic pump. A flushing valve circuit is controlled by the percussion circuit and a circuit for the free circulation of the hydraulic pump which is parallelly coupled with the percussion circuit in relation to the hydraulic pump. The circuits are connected to the hydraulic pump.

Abstract: A rotary percussion hydraulic drilling machine has striker piston slidably mounted inside a cylinder which defines a first annular chamber connected to a one-way valve slidably mounted inside a chamber connected to an accumulator comprising a diaphragm, leading to which is a hydraulic fluid inlet pipe and a second annular chamber connected to a control valve. This control valve, governed by the movements of the piston, connects the second chamber alternately to the high pressure pipe and to the return pipe. The valve, constructed in the form of a sleeve and subject to the force of a spring has a lateral connection allowing the direct passage of fluid to the return pipe, a rotary motor being located in the inlet pipe. Thus solely rotary operation for a rate of flow less than a certain threshold value and rotary/percussive operation for rates of flow beyond this threshold value may be obtained.

Abstract: This invention relates generally to improved means for securing a working member within a rotary tool and is described hereinbelow with particular reference to a percussively actuatable striking bar secured by the novel securing means hereof within a percussive rock drilling apparatus.