Abstract: Different mechanical drive devices for a medical, dental or surgical tool are described that are designed to put the tool into an oscillating, rotational motion, wherein the oscillating, rotational motion comprises an alternating rotation of the tool by a first angle of rotation in a first rotational direction and by a second angle of rotation in a second rotational direction substantially opposed to the first rotational direction, wherein the first and second angles of rotation may have different values, so that during multiple sequential rotations in the first and second rotational directions, the tool cumulatively experiences a rotational motion in a preferred direction.

Abstract: A hand instrument, comprising: a tool-holding device for fastening a treatment tool on the hand instrument, a driveshaft for transmitting a driving movement to the tool-holding device and a stroke gear which is designed to induce the tool-holding device in a stroke movement. According to a first embodiment the hand instrument further has a rotary gear which is designed to induce the tool-holding device to a rotational movement, wherein a drive-side element of the rotary gear and a drive-side element of the stroke gear are arranged jointly on the driveshaft. According to a second embodiment the drive-side element of the stroke gear is designed such, that in a complete revolution of the drive-side element of the stroke gear the tool-holding device runs through more than a double stroke. According to another embodiment the drive-side element of the stroke gear is disposed concentrically around an axis of rotation of the driveshaft.

Abstract: Different mechanical drive devices for a medical, dental or surgical tool are described that are designed to put the tool into an oscillating, rotational motion, wherein the oscillating, rotational motion comprises an alternating rotation of the tool by a first angle of rotation in a first rotational direction and by a second angle of rotation in a second rotational direction substantially opposed to the first rotational direction, wherein the first and second angles of rotation may have different values, so that during multiple sequential rotations in the first and second rotational directions, the tool cumulatively experiences a rotational motion in a preferred direction.

Abstract: A hand instrument, comprising: a tool-holding device for fastening a treatment tool on the hand instrument, a driveshaft for transmitting a driving movement to the tool-holding device and a stroke gear which is designed to induce the tool-holding device in a stroke movement. According to a first embodiment the hand instrument further has a rotary gear which is designed to induce the tool-holding device to a rotational movement, wherein a drive-side element of the rotary gear and a drive-side element of the stroke gear are arranged jointly on the driveshaft. According to a second embodiment the drive-side element of the stroke gear is designed such, that in a complete revolution of the drive-side element of the stroke gear the tool-holding device runs through more than a double stroke. According to another embodiment the drive-side element of the stroke gear is disposed concentrically around an axis of rotation of the driveshaft.