A hydraulic percussion device and method of controlling a working cycle of a percussion piston is provided. A rock breaking machine includes a percussion device provided with a reciprocating piston executing a working cycle. The operation is controlled by means of a control unit generating control signals for independently operable feed and discharge valves of a hydraulic system. The position of the piston is detected by a sensing device.

The method for directionally swaying and resetting harrow teeth of a rolling harrow loader-excavator and the rolling harrow loader-excavator comprising a harrow rotary piece, directional sway and reset harrow teeth, a harrow supporter, a driving mechanism, a feeder mechanism and a body; each directional sway and reset harrow tooth comprises a torsion spring shaft supporting piece, a tooth handle sway limiting piece, a directional sway and reset tooth handle, a directional sway and reset tooth point, a torsion spring tooth handle shaft, a torsion spring and a torsion spring tooth handle shaft retaining piece.

The invention relates to the field of excavation systems, and more particularly to excavation systems including tools for excavation by electric pulses. An excavation system of the invention comprises a support frame (34), a hydraulic circuit with a pump, and first and second excavation tools. One of said first and second excavation tools is a mechanical excavation tool (1) having a hydraulic actuator and a mounting interface with at least one mechanical fastener member and at least one hydraulic coupling in fluid flow communication with said hydraulic actuator, while the other one of said first and second excavation tools is a tool (1) for excavation by electric pulses, comprising an electricity generator (3) with a rotary shaft for generating electricity from rotation of the rotary shaft, a hydraulic motor coupled to said rotary shaft to drive rotation of the rotary shaft, and an electronic power module (4) electrically connected to the electricity generator (3) in order to be powered by the electricity generator (3) so as to generate electric pulses of instantaneous power that is higher than an instantaneous power of the electricity generator (3), a plurality of electrodes (5a, 5p) including at least one electrode (5a) connected to said electronic power module (4), the electrodes being arranged on said front face, and a mounting interface (14) with at least one mechanical fastener member (22), and at least one hydraulic coupling (20) in fluid flow communication with said hydraulic motor (2). Each of the mounting interfaces of the first and second excavation tools is suitable for releasably mounting the corresponding excavation tool in alternation under the support frame (34) of the excavation system, with the corresponding hydraulic coupling in fluid flow communication with said hydraulic circuit of the excavation assembly.

A two-step auto stroke hydraulic breaker includes a cylinder including a high-low pressure chamber, a high pressure chamber, and a pressure converting chamber including a pilot port, a high pressure connecting port connected to the high pressure chamber, a sensing port, an oil tank port, a long stroke port, and a short stroke port, a piston including small diameter portions, upper and lower large diameter portions, a sensing fluid groove between the upper and lower large diameter portions, and a return fluid groove formed on the lower the large diameter portion, a fluid circuit unit to control a supply direction of the fluid to the cylinder and to generate a fluid pressure to selectively change a stroke, and a chisel to break the bedrock when a lower portion of the piston descends to impact the chisel during a descending operation.

A hammer tool assembly for a machine is provided. A hammer tool assembly includes a power cell, a tool and a frame assembly. The frame assembly includes a first side plate and a second side plate. The hammer tool assembly includes a flange member extending from an outer periphery of an outer wall of the first and second side plates. The flange member includes a plurality of serrations that extend from the outer periphery of the outer wall of at least one of the first and second side plates. The hammer tool assembly also includes a plurality of blocks provided in surrounding contact with the power cell and an inner wall of the first and second side plates respectively.

An impact hammer for breaking a working surface, the hammer including a drive mechanism and a housing with an inner containment surface and a reciprocating hammer weight. A reciprocation cycle of the hammer weight includes an upstroke and a down-stroke, the hammer weight respectively moving upwards and downwards. On the down-stroke the hammer weight impacts a striker pin with a driven end and a working surface impact end. A vacuum chamber in the housing is formed by the containment surface, upper vacuum sealing coupled to the hammer weight and lower vacuum sealing. The hammer weight is driven toward the striker pin by the pressure differential between atmosphere and the vacuum chamber formed on the upstroke. A down-stroke vent permits fluid egress from the vacuum chamber on the down-stroke.

A skid steer prying attachment device facilitates removal of large rocks or the like embedded in the ground. The device includes a frame having a top side, a bottom side, and a pair of lateral sides coupled to and extending between the top side and the bottom side. The frame is substantially planar having a forward face and a rearward face. A connector is coupled to the frame wherein the frame is configured for being coupled to a skid steer such that the forward face faces outwardly from the skid steer. A tongue is coupled to and extends from the frame outwardly from the forward face of the frame. A wedge is coupled to and extends from a distal end of the tongue relative to the frame.

A demolition hammer is provided that includes a housing that is reversible and a plurality of interchangeable wear plates. The demolition hammer may include a housing a housing having a first wall and a second wall opposite the first wall, and a power cell disposed within the housing, the power cell having a front face, wherein the housing is reversible such that the housing can be used with the power cell in a first orientation in which the front face faces the first wall and a second orientation in which the front face faces the second wall.

A hydraulic hammer assembly is disclosed. The hydraulic hammer assembly includes a piston and an accumulator membrane disposed external and coaxial to the piston The hydraulic hammer assembly includes a sleeve disposed coaxially between the piston and the accumulator membrane. The sleeve defines a first set of holes in an outer surface thereof to receive hydraulic fluid. The sleeve defines a second set of holes in an inner surface thereof and located distant from the first set of holes along a longitudinal axis of the sleeve. The sleeve defines a plurality of passages within a wall, and extending along the longitudinal axis. Each of the plurality of passages includes a porous medium to increase surface area of each of the plurality of passages. The increased surface area of each of the plurality of passages increases a rate of dissipation of heat from the wall of the sleeve.

An excavating machine, representatively a skid steer, has a pair of loader arms to which an excavating bucket is mounted. A hydraulic breaker assembly is protectively mounted inside the bucket and movable to extend outward therefrom. The bucket may be operated independently of the breaker assembly for digging operations. The breaker assembly may be positioned independently of the bucket and the breaker actuated for removing refusal material. The bucket and the breaker may then be cooperatively operated to perform removal operations. The same excavating machine can be used for digging and breaking operations without the need for a second excavating machine or device dedicated to breaking the refusal material.