Abstract: A feature that contributes to an improvement in the attachment to an impact tool of a dust collection device that is attached to the impact tool and that collects dust particles that said impact tool generates. The dust collection device collects dust that the impact tool generates and is attached to said impact tool that, in the lengthwise direction, linearly operates a tool bit that is mounted to the tip region of a tool body. The dust collection device has: a dust collection unit that has a dust intake port at the tip; and a dust transfer unit that is connected with the dust collection unit in order to transfer dust sucked in from the dust intake port towards the downstream side. The dust collection unit is held by the shaft section of the tool bit, and the dust transfer unit is held by the tool body.

Abstract: It is an object of the invention to reduce noise caused by run-out of a tool bit in an impact tool. The representative impact tool according to the invention includes a tool holder 137 that houses a tool bit 119 in such a manner that the tool bit can linearly move in its axial direction, and a barrel 108 that is integrally connected to the tool holder 137 The impact tool further includes an elastic element 155 that is disposed between an inner circumferential surface of the tool holder 137 and an outer circumferential surface of the tool bit 119 in an end region of the tool bit 119 on the barrel side and connected in close contact with the tool holder 137 and the tool bit 119 over a predetermined length of the tool bit 119 in the axial direction. The elastic element 155 applies a biasing force to prevent a run-out of the tool bit 119 in a direction transverse to the axial direction. Further, an intermediate element 145 comes in point contact with the tool bit 119 on its axial center line.

Abstract: A carrier for carrying a power tool may include a tool bit holder supporting at least one tool bit and a tool bit restraint device that is capable of preventing the at least one tool bit from being dropped out of the tool bit holder. The tool bit restraint device includes a tool bit restraint member. The tool bit restraint member is arranged and constructed so as to substantially uniformly press the at least one tool bit, thereby restraining the at least one tool bit.

Abstract: It is an object of the invention to reduce noise caused by run-out of a tool bit in an impact tool. The representative impact tool according to the invention includes a tool holder 137 that houses a tool bit 119 in such a manner that the tool bit can linearly move in its axial direction, and a barrel 108 that is integrally connected to the tool holder 137 The impact tool further includes an elastic element 155 that is disposed between an inner circumferential surface of the tool holder 137 and an outer circumferential surface of the tool bit 119 in an end region of the tool bit 119 on the barrel side and connected in close contact with the tool holder 137 and the tool bit 119 over a predetermined length of the tool bit 119 in the axial direction. The elastic element 155 applies a biasing force to prevent a run-out of the tool bit 119 in a direction transverse to the axial direction. Further, an intermediate element 145 comes in point contact with the tool bit 119 on its axial center line.

Abstract: It is an object of the invention to provide a technique for adapting to the length of a tool bit mounted to a power tool when tool bits of different lengths are selectively used by replacement to perform an operation, in a dust collecting device for collecting dust generated by operation of the power tool. A dust collecting device 210 is attached to a power tool 101 and collects dust generated by operation. The dust collecting device 210 includes a dust collecting part that covers a tool bit 119 over a predetermined range in the axial direction and collects dust generated by operation. The dust collecting part is formed in one of a first form and a second form which is arbitrarily selected.

Abstract: It is an object of the invention to provide a technique that contributes to further improvement of an impact tool. A representative impact tool includes a motor, a tool body that houses the motor, a dynamic vibration reducer and a driving mechanism part that is driven by the motor and forcibly drives the dynamic vibration reducer by applying an external force other than vibration of the tool body to the dynamic vibration reducer, during hammering operation. At least one of the dynamic vibration reducer and the driving mechanism part is mounted to the tool body in a form of an assembly into which at least one of a plurality of component parts forming the dynamic vibration reducer and a plurality of component parts forming the driving mechanism part are assembled in advance.

Abstract: It is an object of the invention to provide a technique which contributes to improvement of operability in a dust collecting device which is used with a power tool for performing an operation using an internal dust suction type bit and collects dust generated by operation. A dust collecting device 210 is used with a power tool having a tool bit 119 configured as an internal dust suction type bit and includes a dust collecting device body 211 which is mounted to the tool body 103, and a dust collecting part 261 which covers the tool bit 119. The dust collecting part 261 is designed for internal dust suction type bits and fitted on the dust collecting device body 211.

Abstract: A shock-absorbing element is disposed frontward of an interjacent element within a housing of an impact tool, and a washer is disposed rearward of and adjacent to the shock-absorbing element. The interjacent element is configured to come in contact with the washer when the interjacent element is caused to advance by an impactor's strike under no-load conditions. A sleeve disposed rearward of and adjacent to the washer is configured to position the shock-absorbing element and the washer, and to allow the interjacent element to move rearward and frontward inside the sleeve.

Abstract: It is an object of the invention to reduce noise caused by run-out of a tool bit in an impact tool. The representative impact tool according to the invention includes a tool holder 137 that houses a tool bit 119 in such a manner that the tool bit can linearly move in its axial direction, and a barrel 108 that is integrally connected to the tool holder 137 The impact tool further includes an elastic element 155 that is disposed between an inner circumferential surface of the tool holder 137 and an outer circumferential surface of the tool bit 119 in an end region of the tool bit 119 on the barrel side and connected in close contact with the tool holder 137 and the tool bit 119 over a predetermined length of the tool bit 119 in the axial direction. The elastic element 155 applies a biasing force to prevent a run-out of the tool bit 119 in a direction transverse to the axial direction. Further, an intermediate element 145 comes in point contact with the tool bit 119 on its axial center line.

Abstract: A shock-absorbing element is disposed frontward of an interjacent element within a housing of an impact tool, and a washer is disposed rearward of and adjacent to the shock-absorbing element. The interjacent element is configured to come in contact with the washer when the interjacent element is caused to advance by an impactor's strike under no-load conditions. A sleeve disposed rearward of and adjacent to the washer is configured to position the shock-absorbing element and the washer, and to allow the interjacent element to move rearward and frontward inside the sleeve.

Abstract: A carrier for carrying a power tool may include a tool bit holder supporting at least one tool bit and a tool bit restraint device that is capable of preventing the at least one tool bit from being dropped out of the tool bit holder. The tool bit restraint device includes a tool bit restraint member. The tool bit restraint member is arranged and constructed so as to substantially uniformly press the at least one tool bit, thereby restraining the at least one tool bit.

Abstract: It is an object of the invention to provide a technique that contributes to further improvement of an impact tool. A representative impact tool includes a motor, a tool body that houses the motor, a dynamic vibration reducer and a driving mechanism part that is driven by the motor and forcibly drives the dynamic vibration reducer by applying an external force other than vibration of the tool body to the dynamic vibration reducer, during hammering operation. At least one of the dynamic vibration reducer and the driving mechanism part is mounted to the tool body in a form of an assembly into which at least one of a plurality of component parts forming the dynamic vibration reducer and a plurality of component parts forming the driving mechanism part are assembled in advance.

Abstract: A hammer drill has a mode change-over mechanism including a change link with a horizontally elongated slot, an eccentric pin projecting from a mode selector switch and penetrating the slot. The change link is moved vertically by rotating the mode selector switch, which in turn vertically moves a pair of change keys secured to a holder of the change link, thus either engaging or disengaging the change keys with or from a sleeve provided in a rotation transmission mechanism for transmitting the rotation of a motor to the tool holder. In the engagement position, the rotation of the motor of the hammer drill is transmitted to a tool holder while in the disengagement position, the rotation of the motor is not transmitted. Also, the eccentric pin is engaged with a square recess formed in a lock ring which is fitted around the tool holder and urged backward by a compression spring.

Abstract: The invention provides an improved intermediate housing incorporated in a power driven hammer drill, which is light in weight, easily and safely handled, and uncostly manufactured. The intermediate housing of the invention includes a bearing member and a cylindrical piston housing member which are integrally composed of a synthetic resin having high tenacity and excellent heat resistance and wear resistance. The intermediate housing further includes a plurality of ribs radially extending from the piston housing member to give a sufficient strength durable to a stress applied onto the piston housing member. In the intermediate housing thus constructed, the bearing member has at least one opening for feeding an air flow generated by a fan while the piston housing member includes at least one air conduit for circulating the air flow. This structure efficiently prevents overheat and thermal deformation of the piston housing member and the bearing member in continuous operation of the hammer drill.