Drive unit for rotary tools
AssigneeHertel AG Werkzeuge & Hartstoffe
InventorsGunther Hertel, Karl G. Hertel
Life of this patent
Estimating the term…
Abstract
A drive unit for a rotary tool, which unit includes a housing, a drive shaft mounted in the housing for transferring rotational drive force from a rotary drive to the tool, and a clamping mechanism mounted in the housing for generating a tool clamping movement along the axis of the drive shaft. The drive shaft is a hollow shaft, the clamping mechanism includes a pull rod mounted in the drive shaft and coaxially positioned relative to the drive shaft, the pull rod being mounted to be axially displaceable and fixed against rotation relative to the drive shaft, and the unit further includes a blocking device operative between the drive shaft and the housing for permitting the drive shaft to rotate relative to the housing only when the drive shaft is coupled to the rotary drive.
Claims14
In a drive unit for a rotary tool, which unit includes:
- a housing having a tool receiving side and a drive power input side;
- a hollow drive shaft mounted in the housing for transferring rotational drive force from a first drive motor to the tool;
- and clamping means disposed within the drive shaft for generating a tool clamping movement along the axis of the drive shaft, the improvement wherein:
- said clamping means comprise:
- a pull rod having screw threads and mounted in said hollow drive shaft and coaxially positioned relative to said hollow drive shaft, said pull rod being mounted to be axially displaceable, and fixed against rotation, relative to said hollow drive shaft;
- a sleeve mounted in said hollow drive shaft to be axially fixed, and rotatable, relative to said hollow drive shaft, said sleeve being threaded to mate with the threads on said pull rod so that said sleeve and said pull rod form a screw and nut mechanism, with said pull rod being disposed between said sleeve and said tool receiving side of said housing;
- and a clamping drive shaft couplable to a clamping rotary drive and operatively associated with said sleeve for rotating said sleeve when said clamping drive shaft is rotated by the clamping rotary drive;
- and
- said unit further comprises blocking means operative between said hollow drive shaft and said housing to be automatically activated by connection of the first drive motor to said hollow drive shaft for permitting said hollow drive shaft to rotate relative to said housing only when said hollow drive shaft is coupled to the first drive motor, and to block rotation of said hollow drive shaft relative to said housing when said clamping drive shaft is coupled to the clamping rotary drive.
Dependencies are inferred from the claim text.