Patent ID: 7028997

Claim:
A vibration damping tool comprising: a tool body provided at a distal end portion thereof with processing means for processing a material to be cut, said tool body having a hollow portion formed inside and defined by an inner wall surface, said tool body and said hollow portion extending along a longitudinal axis; a base plate connected to the tool body at the distal end thereof at a first base plate surface to cover the hollow portion; a longitudinally-extending weight member comprising a shaft portion integrally connected to and projecting from the first base plate surface of the base plate into the hollow portion, and a weight member portion having a larger diameter than that of the shaft portion and integrally connected to the shaft portion to extend toward yet disposed apart from the inner wall surface on a base end side of said tool body opposite said base plate, with a first gap formed at a radial distance from the longitudinal axis between said inner wall surface of the hollow portion and said weight member portion of said weight member and with a second gap formed at a rectilinear distance along the longitudinal axis between a distal end of the weight member portion and the base end side of said tool body; and a visco-elastic body filled only into a portion or all of said first gap, whereby said weight member and said visco-elastic body constitute a dynamic vibration absorber that damps and absorbs vibration of the tool body and wherein the visco-elastic body is fabricated from a solid yet elastic material having a Young's modulus of not more than 1000 kPa, a hardness penetration of 20 to 300 based on 1/10 mm, a tensile strength of 1 to 4000 kPa and an elongation of 50 to 800% and wherein said hollow portion is formed so as to extend from said distal end portion along the longitudinal axis in an axial direction of the tool body with the processing means connected directly to a second base plate surface of the base plate, the second base plate surface being disposed opposite to the first base plate surface.