Impact power tool
AssigneeMakita Corporation
InventorYonosuke Aoki
Life of this patent
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Abstract
An object of the invention is to provide an improved technique for lessening an impact force caused by rebound of a tool bit after its striking movement in an impact power tool. The representative impact power tool comprises a tool body, a hammer actuating member, a tool holder, a driving mechanism, a weight placed in contact with the hammer actuating member to move rearward by a reaction force transmitted from the hammer actuating member when the hammer actuating member performs a hammering operation on the workpiece and an elastic element elastically deformed when the weight moves rearward in the tool body to push the elastic element such that the elastic element absorbs the reaction force transmitted to the weight. The weight is defined one or both of the cylinder and the tool holder.
Claims8
An impact power tool comprising:
- a tool body,
- a hammer actuating member that is disposed in a tip end region of the tool body and performs a predetermined hammering operation on a workpiece by reciprocating movement in its axial direction,
- a tool holder that at least partially holds the hammer actuating member, wherein the tool holder is mounted to a gear housing such that the tool holder is prevented from relative movement in the axial direction with respect to the gear housing,
- a driving mechanism that is disposed on a rear side of the tool body opposite the hammer actuating member and linearly drives the hammer actuating member,
- a cylinder that houses the driving mechanism, the cylinder being mounted to the gear housing such that the cylinder is slidable in an axial direction of the cylinder relative to a crankshaft mechanism that drives the driving mechanism, and
- an elastic element, wherein
- a weight defined by at least one of (i) the slidable cylinder, (ii) a slidable rear extension of the tool holder and (iii) a slidable weight part of the elastic element, is placed in contact with the hammer actuating member to move rearward in the tool body when a reaction force is transmitted thereto from the hammer actuating member during a hammering operation on the workpiece, and
- the elastic element elastically deforms when the weight moves rearward in the tool body and pushes against the elastic element such that the elastic element absorbs the reaction force transmitted to the weight.
Dependencies are inferred from the claim text.