A percussion drilling device for drilling in earth includes at least one housing section for a main piston, and a ring insert arranged in the housing section in front of the main piston so that the ring insert transmits at least part of the energy of the main piston onto the housing. The ring insert is attached to the housing by a shrink-fit connection.

The objective of the present invention is to provide a hydraulic breaker comprising: a hydraulic breaker body part; a sensor part sensing vibration generated in the hydraulic breaker body part when objects to be crushed, including bedrocks, are crushed, so as to output a sensing signal; and a control part receiving the sensing signal so as to calculate the time for which the hydraulic breaker body part vibrates, thereby calculating an operating time.

The objective of the present invention is to provide a hydraulic breaker comprising: a hydraulic breaker body part; a sensor part sensing vibration generated in the hydraulic breaker body part when objects to be crushed, including bedrocks, are crushed, so as to output a sensing signal; and a control part receiving the sensing signal so as to calculate the time for which the hydraulic breaker body part vibrates, thereby calculating an operating time.

Provided is a two-piston hydraulic striking device that has stable operatively. This two-piston hydraulic striking device includes two striking mechanisms for striking one transfer member. Each striking mechanism has a pressure receiving area ratio between the front and rear of a piston thereof set in such a way that the two striking mechanisms have the same cycle time.

Provided is a two-piston hydraulic striking device that has stable operatively. This two-piston hydraulic striking device includes two striking mechanisms for striking one transfer member. Each striking mechanism has a pressure receiving area ratio between the front and rear of a piston thereof set in such a way that the two striking mechanisms have the same cycle time.

A processor-controlled, energy-based therapy apparatus includes a device configured to provide therapeutic energy to a patient and a processor that controls the output of the device. The output of the device is based on output profiles programmed into the processor. The output profiles include a therapeutic energy output profile and a ramp-up energy profile. The therapeutic energy output profile includes a desired target energy level and a therapeutic duration for controlling the output of the device during a therapeutic period. The ramp-up energy output profile includes an initial treatment energy level and a ramp-up duration for controlling the output of the device during a ramp-up period. The energy output specified by the ramp-up energy output profile incrementally increases over the ramp-up duration as a function of the desired target energy level and the ramp-up duration.

A processor-controlled, energy-based therapy apparatus includes a device configured to provide therapeutic energy to a patient and a processor that controls the output of the device. The output of the device is based on output profiles programmed into the processor. The output profiles include a therapeutic energy output profile and a ramp-up energy profile. The therapeutic energy output profile includes a desired target energy level and a therapeutic duration for controlling the output of the device during a therapeutic period. The ramp-up energy output profile includes an initial treatment energy level and a ramp-up duration for controlling the output of the device during a ramp-up period. The energy output specified by the ramp-up energy output profile incrementally increases over the ramp-up duration as a function of the desired target energy level and the ramp-up duration.

A hydraulic striking device that is mounted on construction equipment such as an excavator and breaks solid rocks in the grounds using a rod that is hit by a piston is proposed. Particularly, a hydraulic striking device that can automatically switch stroke modes by sensing the intensity of pressure of an upper chamber formed at an upper portion between a piston and a cylinder in accordance with the statuses of rocks in the ground is proposed.

A hammer drill having a motor mounted within a body and an output spindle; a tool holder mounted on the body capable of holding a cutting tool; a hammer mechanism having a piston; a reciprocating drive for converting rotary movement of the motor into reciprocating movement of the piston; a ram reciprocatingly driven by the piston via an air spring to strike a cutting tool held in the tool holder, the hammer mechanism performing one hammer cycle each time the ram strikes a cutting tool during normal use; an air replenishment mechanism capable of refreshing the air spring during certain time periods during normal use; the air replenishment mechanism capable of being adjusted to refresh the air spring during time periods within the hammer cycle and/or the system allows different volumes of air into or out of the air spring during the refreshment time periods.

A hammer drill having a motor mounted within a body and an output spindle; a tool holder mounted on the body capable of holding a cutting tool; a hammer mechanism having a piston; a reciprocating drive for converting rotary movement of the motor into reciprocating movement of the piston; a ram reciprocatingly driven by the piston via an air spring to strike a cutting tool held in the tool holder, the hammer mechanism performing one hammer cycle each time the ram strikes a cutting tool during normal use; an air replenishment mechanism capable of refreshing the air spring during certain time periods during normal use; the air replenishment mechanism capable of being adjusted to refresh the air spring during time periods within the hammer cycle and/or the system allows different volumes of air into or out of the air spring during the refreshment time periods.