A hydraulic hammer for a working machine configured for digging a surface includes a housing, a chisel, sensors, and a controller. The housing is coupled to the working machine. The chisel is partially enclosed by the housing and extendable from the housing for digging the surface at a contact location. Each of the sensors is configured for generating a signal indicative of a projecting distance between one of the sensors and the surface. The controller is configured for receiving the signals, determining an angle between the chisel and a plane substantially tangent to the contact location, and reorienting the chisel so that the chisel is substantially orthogonal to the contact location with the angle at substantially ninety degrees.

A leveling device assembly for use with a hydraulic hammer is provided. The leveling device assembly comprises a control unit, a leveling sensor in communication with the control unit, and a laser generator in communication with the control unit. Additionally, the laser generator is configured to produce a first colored light beam and a second colored light beam different from the first colored light beam. The control unit is further configured to cause the laser generator to produce the first colored light beam when the leveling sensor indicates the hydraulic hammer is in a substantially vertical position and produce the second colored light beam when the leveling sensor indicates the hydraulic hammer is in a substantially non-vertical position.

A leveling device assembly for use with a hydraulic hammer is provided. The leveling device assembly comprises a control unit, a leveling sensor in communication with the control unit, and a laser generator in communication with the control unit. Additionally, the laser generator is configured to produce a first colored light beam and a second colored light beam different from the first colored light beam. The control unit is further configured to cause the laser generator to produce the first colored light beam when the leveling sensor indicates the hydraulic hammer is in a substantially vertical position and produce the second colored light beam when the leveling sensor indicates the hydraulic hammer is in a substantially non-vertical position.

Provided is a hydraulic hammering device having improved hammering efficiency and of low cost. A piston has a valve switching groove between large-diameter sections thereof. A cylinder has three control ports at positions corresponding to the valve switching groove. A switching valve mechanism has a valve presser for always pressing a valve in one direction and also has a valve controller for moving, when supplying pressurized oil, the valve in the opposite direction against the pressing force of the valve presser. A valve control port communicates with the valve controller so as to supply the pressurized oil to the valve controller and is separated from a piston front chamber and a piston rear chamber. Only either a piston retraction control port or a piston advance control port communicates with the valve control port depending on advance or retraction of the valve switching groove.

A device for monitoring pressure within a gas space, which is filled with gas, preferably nitrogen, and/or is prestressed, of a pressure accumulator of a hydraulically driven percussive mechanism having a housing in which a piston is mounted, together with a display element which extends through the face surface of the housing, so as to be slidingly movable counter to the force of a spring, wherein the piston divides the housing into a pressure chamber and a spring chamber. The spring acts on a spring chamber-side working surface of the piston, and the pressure accumulator is at least indirectly operatively connected to the pressure chamber-side working surface of the piston, such that, in the event of a critical pressure within the pressure accumulator being undershot, the piston and the display element are displaced to such an extent that the display element protrudes out of the housing.

A pressure indicator for a hydraulic hammer is provided. The pressure indicator includes a sleeve member configured to couple to an opening defined in a wall housing of an accumulator of the hydraulic hammer. The pressure indicator further includes a plunger slidably disposed within the sleeve member and movable between a first position and a second position with respect to the sleeve member. The plunger includes a first end disposed outside the wall housing of the accumulator. The plunger further includes a flange coupled to a second end. The pressure indicator further includes an elastic member inserted over the plunger and disposed between the wall housing of the accumulator and the flange. A position of the first end of the plunger with reference to an outer end of the sleeve member provides a visual indication of the pressure of the gas within the accumulator.

A hydraulic hammer for impact fracturing a work object includes a hammer shell having a cylinder body disposed between a front head and a rear head. A piston reciprocally movable within the cylinder body abut a work tool and can extend and retract the work tool from the hammer shell. To dampen momentum and impact forces, an accumulator head is attached to the back head and can accommodate hydraulic and dampening fluids in separate first and second sub-chambers. The dampening sub-chamber may directly fluidly communicate with an internal dampening fluid reservoir in the back head.

A pressure accumulator, rock breaking machine and method of storing pressure energy. The accumulator includes a casing and an elastic membrane arranged inside the casing. The membrane divides an inner space of the casing into two separate pressure spaces. A gas space is prefilled with pressurized gas. On the opposite side of the membrane is a hydraulic space for receiving hydraulic fluid. The membrane is a hat-like element having side walls, a mounting flange at its open end and a closed top end. The mounting flange of the membrane is mounted between the casing and a flange element. The accumulator is without a screen. The flange element is provided with a sealing for sealing a piston.

An apparatus for generating impulse-dynamic process forces includes a pressure chamber, a connecting chamber and a bolt chamber The pressure chamber includes a plunger arranged to be pushed into the pressure chamber for compression of a hydraulic medium 1ocated therein. In the connecting chamber there is displaceably arranged a stepped pistons which has a valve body for closing an orifice connecting the pressure chamber to the connecting chamber. In the bolt chamber there is located a displaceable impact bolt which has a first bolt portion and a second bolt portion The first bolt portion seals an interior space of the bolt chamber that surrounds the second bolt portion. Connected to the bolt chamber there is at least one pressure reservoir containing pressurised pressure medium, which pressure reservoir is in communicating connection via a connection port with the interior space of the bolt chamber.

A device for monitoring the pressure within a gas space, which is filled with a gas, preferably nitrogen, and/or is prestressed, of a pressure accumulator of a hydraulically driven percussive mechanism, in particular of a demolition hammer or of a drilling hammer, having a housing in which a piston is mounted, together with an indicator element which extends through the face surface of the housing, in slidingly movable fashion. The piston divides the housing into two chambers, and a first, pressure accumulator-side chamber and a pressure accumulator-side working surface, which is averted from the indicator element, of the piston are operatively connected at least indirectly to the gas space of the pressure accumulator. A second, hydraulics-side chamber and a hydraulics-side working surface, facing toward the indicator element, of the piston are connected to the hydraulic system of the percussive mechanism.