A hand tool includes an apparatus housing (2), a drive shaft part (10) which is rotatable in the housing, and toolholder part (18) which is mounted pivotably in the housing, is operatively connected to the drive shaft part and has a securing portion (24) projecting from the housing for the purpose of receiving a file, for example. A shaft journal (30) is secured in the drive shaft part (10) and is eccentrically positioned (R) in relation to the center line (A) of the drive shaft part. The shaft journal (30) supports, on its section (48) outside the drive shaft part, a movement-transmitting member (50') with an outer limit surface (52'). This member is arranged in drive engagement with a recess (54) in the end portion of the toolholder part (18) located inside the apparatus housing (2). In the recess (54) the movement-transmitting member (50') can move transverse to the toolholder part (18), with the outside (52') rolling against adjoining contact surfaces (56, 58) which delimit the recess. The circular eccentric movement of the shaft journal (30) about the center axis (A) of the drive shaft part (10) imparts to the toolholder part (18), mounted pivotably in the housing (2), a sideways pendulum movement when the drive shaft part is rotating.
An oscillatory drive comprising a rotating drive shaft is disclosed. The oscillatory drive is driven by an eccentric element that is coupled via a pivot element to a tool drive shaft arranged at an angle to the drive shaft for oscillatingly driving the tool drive shaft pivoting back and forth about its longitudinal axis. The eccentric element comprises a spherical outer ring which is guided within an at least partially cylindrical inner surface of the pivot element. By spring biasing the free end of the pivot element at both outer sides against the housing, efficiency is improved and vibrations are reduced.
In a power grinder (1) with a motor (6) and a gear (7) that drive an oscillating drive means (2), which moves a grinding belt (3) secured to it to reciprocate, a simple change of the grinding belt (3) is made possible by providing that the grinding belt (3) has a hook-and-loop closure (4), or the grinding belt (3) is disposed with its first end (11) on the drive means (2), and its second end (12) is connected to a handle (13).
A power tool (10) with a housing (12) which accommodates a driven shaft (32) for holding a material-removing tool (40) and which sets the driven shaft into rotary oscillating motion capable of being produced by an eccentric (22) rotating around an axis extending at a right angle to the driven shaft (32), the eccentric engaging in a connecting element coupled with the driven shaft (32), is usable in a more diverse manner because the rotary oscillating motion of the driven shaft (32) and, therefore, the tool (40), is adjustable with a certain travel and is therefore adaptable to special applications.
The present invention relates particularly to an oscillating grinding machine. The grinding machine comprises a driving motor (3) surrounded by a body (3), and a drive shaft (4) cooperating with the driving motor. The drive shaft comprises a grinding head (5) that constitutes a support for a grinding product (8). The drive shaft (4) is arranged in two pieces and comprises a main shaft (11) and an eccentric shaft (10) arranged rigidly thereto. The eccentric shaft comprises a centre line (12) that assumes an angle (.alpha.) against a corresponding centre line (13) of the main shaft, and thus the grinding head (5) will assume an eccentric placement in relation to the main shaft (11). Thus, the grinding head is arranged to oscillate in a substantially spherical plane provided by the rotation of the main shaft and the eccentricity and inclination of the eccentric shaft in relation to the main shaft.
