Device (30) for making a hole in a golf green (100), comprising a cutting cylinder (4) with an open end being freely movable along the longitudinal direction; guide means (1) defining a weight path having a first endpoint and a second endpoint; a weight (5) guidedly movable along said weight path; a weight propulsion device, arranged to propel the weight reciprocally so that it strikes against the cutting cylinder; and a soil expulsion piston (9), movable inside said cutting cylinder.

The invention is characterised in that the device further comprises a piston driving mechanism, arranged to transfer a force from said weight is propulsion device to the piston to drive it towards said open end; and an expulsion activating mechanism, arranged to engage and disengage the piston driving mechanism in relation to the weight propulsion device.

The invention also relates to a method.

Device (30) for making a hole in a golf green (100), comprising a cutting cylinder (4) with an open end being freely movable along the longitudinal direction; guide means (1) defining a weight path having a first endpoint and a second endpoint; a weight (5) guidedly movable along said weight path; a weight propulsion device, arranged to propel the weight reciprocally so that it strikes against the cutting cylinder; and a soil expulsion piston (9), movable inside said cutting cylinder.

The invention is characterised in that the device further comprises a piston driving mechanism, arranged to transfer a force from said weight is propulsion device to the piston to drive it towards said open end; and an expulsion activating mechanism, arranged to engage and disengage the piston driving mechanism in relation to the weight propulsion device.

The invention also relates to a method.

The present invention relates to a hydraulic breaker. The valve is installed on an inner surface of the cylinder bush and the cylinder inner diameter portion to be movable in the vertical direction. The valve includes an upper valve portion having an upper end surface on which the pressure of the upper cylinder chamber acts, a lower valve portion having a lower end surface on which the pressure of the upper cylinder chamber acts, a first valve expanded-diameter portion which is formed between the upper valve portion and the lower valve portion, of which an outer diameter expands to be greater than outer diameters of the upper valve portion and the lower valve portion, and in which a first upper valve hydraulic pressure area communicates with the first and second flow channels, and a second valve expanded-diameter portion which is formed between the first valve expanded-diameter portion and the lower valve portion, of which an outer diameter expands to be greater than an outer diameter of the first valve expanded-diameter portion, and in which the second upper valve hydraulic pressure area communicates with the fourth flow channel, and the pressure of the valve switching chamber acts on a lower valve hydraulic pressure area having an area greater than an area of the first upper valve hydraulic pressure area.

The present invention relates to a hydraulic breaker. The valve is installed on an inner surface of the cylinder bush and the cylinder inner diameter portion to be movable in the vertical direction. The valve includes an upper valve portion having an upper end surface on which the pressure of the upper cylinder chamber acts, a lower valve portion having a lower end surface on which the pressure of the upper cylinder chamber acts, a first valve expanded-diameter portion which is formed between the upper valve portion and the lower valve portion, of which an outer diameter expands to be greater than outer diameters of the upper valve portion and the lower valve portion, and in which a first upper valve hydraulic pressure area communicates with the first and second flow channels, and a second valve expanded-diameter portion which is formed between the first valve expanded-diameter portion and the lower valve portion, of which an outer diameter expands to be greater than an outer diameter of the first valve expanded-diameter portion, and in which the second upper valve hydraulic pressure area communicates with the fourth flow channel, and the pressure of the valve switching chamber acts on a lower valve hydraulic pressure area having an area greater than an area of the first upper valve hydraulic pressure area.

The hydraulic rotary-percussive hammer drill includes a body; a shank; a striking piston configured to hit the shank; a stop piston configured to position the shank in a predetermined balanced position, the body and the stop piston delimiting a first control chamber permanently connected to a high-pressure fluid feed-in conduit and configured to urge the stop piston forwards, and a second control chamber configured to urge the stop piston forwards. The hydraulic rotary-percussive hammer drill comprises a fluidic communication channel opening into the second control chamber, configured to supply the second control chamber with high-pressure fluid and provided with a calibrated orifice.

A hydraulic, pneumatic, gasoline, diesel, or electric tool may include a spindle that is adapted for rotational movement. A swing arm may be coupled to the spindle such that rotational motion of the spindle is transferred to the swing arm. The swing arm makes contact with a piston such that the rotational motion causes the piston to move along a linear path. The piston may interact with an energy storage medium when the swing arm moves the piston in the first direction, causing energy to be stored in the energy storage medium. As the swing arm continues to rotate, the swing arm may lose contact with the piston, thus allowing the energy storage medium to urge the piston in a second direction opposite the first direction to strike an anvil. The swing arm may be a multiple roller swing arm. The energy storage medium may be a compound spring assembly.

A hydraulic, pneumatic, gasoline, diesel, or electric tool may include a spindle that is adapted for rotational movement. A swing arm may be coupled to the spindle such that rotational motion of the spindle is transferred to the swing arm. The swing arm makes contact with a piston such that the rotational motion causes the piston to move along a linear path. The piston may interact with an energy storage medium when the swing arm moves the piston in the first direction, causing energy to be stored in the energy storage medium. As the swing arm continues to rotate, the swing arm may lose contact with the piston, thus allowing the energy storage medium to urge the piston in a second direction opposite the first direction to strike an anvil. The swing arm may be a multiple roller swing arm. The energy storage medium may be a compound spring assembly.

The hydraulic rotary-percussive hammer drill includes a fluid injection portion including a fluid feed-in inlet and an annular inner groove fluidly connected to the fluid feed-in inlet; a shank including a fluid injection conduit fluidly connected to the annular inner groove; front and rear main sealing gaskets disposed on either side of the annular inner groove and configured to cooperate with a first shank portion of the shank; a rear backup sealing gasket located at the rear of the rear main sealing gasket and configured to cooperate with a second shank portion of the shank; a leakage passage defined between the shank and the fluid injection portion; pressure drop generation means configured to generate pressure drops in the leakage passage when a leakage flow flows in the leakage passage.

The hydraulic rotary-percussive hammer drill includes a fluid injection portion including a fluid feed-in inlet and an annular inner groove fluidly connected to the fluid feed-in inlet; a shank including a fluid injection conduit fluidly connected to the annular inner groove; front and rear main sealing gaskets disposed on either side of the annular inner groove and configured to cooperate with a first shank portion of the shank; a rear backup sealing gasket located at the rear of the rear main sealing gasket and configured to cooperate with a second shank portion of the shank; a leakage passage defined between the shank and the fluid injection portion; pressure drop generation means configured to generate pressure drops in the leakage passage when a leakage flow flows in the leakage passage.

An example bushing of a hydraulic hammer tool includes an outer region and an inner region. The inner region has a relatively greater hardness than the outer region. The inner region may also be compressively stressed, while the outer region may have tensile stress. The stress and/or hardness profile of the bushing may enhance its resistance to wear and galling defects when a hammer of the hydraulic hammer tool is held in alignment by the bushing. The outer region of the bushing may be relatively soft, resulting in the bushing having a relatively high level of toughness. The bushing may be formed using medium to high carbon steel by rough forming the bushing, hardening the bushing, tempering the bushing, and induction softening the outer region of the bushing.