Vibration reduction apparatus for power tool and power tool incorporating such apparatus
AssigneeBlack & Decker Inc.
InventorsMichael Stirm, Heinz-Werner Faatz
Life of this patent
Estimating the term…
Abstract
A vibration reduction apparatus for use with a hammer tool having a hammer piston is disclosed. The hammer piston is caused to reciprocate in the cylinder by rotation of a gear wheel and crank drive. A cam is mounted around the gear wheel, a counterweight surrounds the piston cylinder, and a cam follower is provided on the counterweight. The cam follower on the counterweight is urged into contact with the cam by a biasing element. The external profile of the cam is such that rotation of the gear wheel causes oscillation of the counterweight in anti-phase to motion of the hammer piston to counteract vibrations produced by operation of the hammer action of the tool.
Claims18
A vibration reduction apparatus for a power hammer apparatus comprising a housing, a motor arranged in the housing, a piston, a reciprocating drive drivable by the motor to drive the piston in reciprocating motion in a bore, and a flying mass arranged in the bore such that said reciprocating motion of said piston in said bore in use causes reciprocating motion of said flying mass relative to the housing to impart impacts to a working member of the hammer apparatus, the vibration reduction apparatus comprising a driveable mass surrounding at least part of the bore, a cam rotatable by the reciprocating drive and engagable to the drivable mass, and a first biasing member for urging the drivable mass into driving engagement with the cam and wherein the driveable mass is caused by the motor to execute reciprocating motion to at least partially cancel vibration of said housing caused by reciprocating motion of the flying mass relative to the housing.
A power hammer apparatus comprising:
- a housing;
- a motor arranged in the housing;
- a piston drivable said motor to execute reciprocating motion in a bore;
- a flying mass arranged in the bore such that said reciprocating motion of said piston in said bore in use causes reciprocating motion of said flying mass relative to said housing to impart impacts to a working member of the power hammer apparatus;
- and
- a vibration reduction apparatus including:
- a drivable mass at least partially surrounding the bore;
- a cam drivable said motor;
- a first biasing member for urging the counter weight into driving engagement with the cam;
- and
- wherein the drivable mass is drivable by the cam, against the first biasing member, to execute reciprocating motion to at least partially cancel vibration caused by reciprocating motion of the flying mass relative to the housing.
Dependencies are inferred from the claim text.