A hammer including a housing and a piston arranged for reciprocating movement within the housing is disclosed. The hammer further includes a head assembled on the housing and defining a chamber for holding a pressurized gas and a wall configured to abut the housing and defining a gas discharge passage extending between the chamber and the housing. A plug is positioned in the gas discharge passage and configured to move or deform under pressure of the pressurized gas in the chamber.

A hammer including a housing and a piston arranged for reciprocating movement within the housing is disclosed. The hammer further includes a head assembled on the housing and defining a chamber for holding a pressurized gas and a wall configured to abut the housing and defining a gas discharge passage extending between the chamber and the housing. A plug is positioned in the gas discharge passage and configured to move or deform under pressure of the pressurized gas in the chamber.

A sleeve is disclosed for use with a piston of a hydraulic hammer. The sleeve may have a generally cylindrical body with a top end and a bottom end, and a central bore passing axially from the top end of the generally cylindrical body to the bottom end. The generally cylindrical body may be a composite structure including a guide layer forming an inner annular surface of the central bore, an energizer layer located radially outward of the guide layer and being bonded to the guide layer, and a support layer bonded to the energizer layer. The support layer may form an outer surface of the generally cylindrical body.

A sleeve is disclosed for use with a piston of a hydraulic hammer. The sleeve may have a generally cylindrical body with a top end and a bottom end, and a central bore passing axially from the top end of the generally cylindrical body to the bottom end. The generally cylindrical body may be a composite structure including a guide layer forming an inner annular surface of the central bore, an energizer layer located radially outward of the guide layer and being bonded to the guide layer, and a support layer bonded to the energizer layer. The support layer may form an outer surface of the generally cylindrical body.

A cushion device is used for a cylinder of a pneumatic tool, and the pneumatic tool contains: a body, a cylinder, a valve unit, a piston member, a cushion washer, and at least one spring. The body includes a grip and a fitting sleeve having a chamber, a closing element, and an opening. The cylinder is fitted in the chamber and includes a room and an abutting portion. The valve unit is mounted between the room and the abutting portion. The piston member is accommodated in the room and slides along a movement axis. The cushion washer and the at least one spring are mounted in the chamber, and the cushion washer abuts against the closing element and the pressing face. The cushion washer includes at least one open segment which has at least one air groove each having a mouth parallel to the movement axis.

The present invention relates to a hydraulic percussion device and a construction apparatus having the same, the hydraulic percussion device comprising: a cylinder; a piston; a backward port connecting a front chamber of the cylinder to a hydraulic source; a forward port formed on a rear chamber of the cylinder; a forward/backward valve for controlling the forward and backward movement of the piston; a control line for moving the forward/backward valve to a forward-movement location; a long-stroke port formed between the forward port and the backward port; a short-stroke port formed between the backward port on the cylinder and the long-stroke port; a shift valve disposed between the short-stroke port and the control line; a proximity sensor for detecting a bottom dead point of the piston upon the stroke on an object; and a controller for determining a striking condition on the basis of the detected bottom dead point, and transmitting a control signal to the shift valve.

The present invention relates to a hydraulic percussion device and a construction apparatus having the same, the hydraulic percussion device comprising: a cylinder; a piston; a backward port connecting a front chamber of the cylinder to a hydraulic source; a forward port formed on a rear chamber of the cylinder; a forward/backward valve for controlling the forward and backward movement of the piston; a control line for moving the forward/backward valve to a forward-movement location; a long-stroke port formed between the forward port and the backward port; a short-stroke port formed between the backward port on the cylinder and the long-stroke port; a shift valve disposed between the short-stroke port and the control line; a proximity sensor for detecting a bottom dead point of the piston upon the stroke on an object; and a controller for determining a striking condition on the basis of the detected bottom dead point, and transmitting a control signal to the shift valve.

The rotary-percussive hydraulic perforator includes a body; a shank; a striking piston configured to strike the shank and provided with a braking surface; a braking chamber configured to hydraulically brake the striking piston; a stop piston configured to apply a pushing force on the shank and provided with a bearing surface configured to abut against a stop surface provided on the body, so as to limit the stroke of displacement of the stop piston towards the shank. The rotary-percussive hydraulic perforator is configured such that the bearing surface and the stop surface are axially spaced apart by a predetermined spacing distance simultaneously when (i) the shank bears on the stop piston and is in contact with the striking piston, and (ii) the braking surface is located at an inlet edge of the braking chamber.

An accumulator assembly includes a vessel having an upper portion and a lower portion. The accumulator assembly includes a flexible membrane extending between the upper portion and the lower portion. The membrane may divide the vessel into a first interior chamber and a second interior chamber. The accumulator assembly includes a receptacle located proximate the vessel. The receptacle may be in fluid communication with the second interior chamber. The accumulator assembly includes a plunger located at least partially within the receptacle.

Systems and methods for management of material stresses present at transitions between facets of an anvil and the anvil shaft are described. In one aspect, an apparatus includes an impact tool anvil extending along an axis of extension and having a faceted drive end and a shaft body which is connected to the faceted drive end through a transition region that couples respective faces of the faceted drive end to the shaft body, the transition region including a sweeping radius surface having a first axial end and a second axial end, the first axial end connected to a respective face of the faceted drive end, the first axial end having a tangency with the respective face of the faceted drive end; and an angular transition having a slope that radially rises from the second axial end of the sweeping radius surface to the shaft body.