초록 ▼

A working tool, in particular a soil rammer or hammer, has two masses that may be linearly moved back and forth with respect to one another, namely, a top mass which has a driving motor and a ramming or striking working mass which can be moved by the motor relative to the top mass by means of a cran

A working tool, in particular a soil rammer or hammer, has two masses that may be linearly moved back and forth with respect to one another, namely, a top mass which has a driving motor and a ramming or striking working mass which can be moved by the motor relative to the top mass by means of a crank drive and a set of springs. In order to reduce as much as possible the displacement of the top mass, an additional counterweight can be moved by the motor over at least a large part of the path of displacement of the working mass in the opposite direction thereto. The displacement of the end of the set of springs linked to the crank drive and the displacement of the counterweight are preferably offset relative to one another, with respect to the crank angle, by 180.degree. minus a phase shift derived from the construction parameters of the set of springs.

대표청구항 ▼

[ What is claimed is:] [1.]1. A working appliance comprising:a working mass which can be driven to reciprocate linearly back and forth, via a crank mechanism, by a motor of an upper mass of the working appliance; anda countermass which can be driven in rotation by the motor and via which a force opp

[ What is claimed is:] [1.]1. A working appliance comprising:a working mass which can be driven to reciprocate linearly back and forth, via a crank mechanism, by a motor of an upper mass of the working appliance; anda countermass which can be driven in rotation by the motor and via which a force opposed to a force acting on the upper mass as a result of the movement of the working mass can be generated, the countermass having a first centrifugal weight rotatable about an axis of rotation that is coaxial with an axis of rotation of the crank mechanism and a second centrifugal weight rotatable in opposition to a direction of rotation of the first centrifugal weight;wherein the second centrifugal weight is arranged rotatably about an axis of rotation that is arranged at least essentially coaxially to the axis of rotation of the crank mechanism.