Cutting by use of rotating axially moving tool – Tool or tool with support – Including detailed shank
Patent
1998-04-13
1999-11-16
Howell, Daniel W.
Cutting by use of rotating axially moving tool
Tool or tool with support
Including detailed shank
175395, 175415, 279 193, 279 75, 408240, B23B 5102
Patent
active
059845961
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an insertable tool for an electrical machine, particularly a hand-held tool for drilling and/or impact operations, including a tool shaft that can be inserted into a respective tool holder of the machine, the shaft having means for rotary driving and axial locking. The invention also relates to a tool holder for the machine having a receiving sleeve and an impact bolt for the tool shaft of the insertable tool.
2. Prior Art
From German Patent Disclosure DE 43 17 273 A1, embodiments for improving the rotary driving of insertable tools are already known, in which, in addition to the rotary driving grooves on the tool shaft, rotary driving cleats are also disposed on the circumference of the shaft. Although this does increase the rotary driving face and thus reduces wear, nevertheless the core cross section of the shaft is still weakened by both the rotary driving grooves and locking troughs, so that in impact operation, the shock wave introduced into the tool shaft by the impact bolt of the machine is not optimally carried to the tool tip. Moreover, notching effects arise at the base of the rotary driving grooves, and under severe rotary stress or rebound impact if the chiseling tool is titled can lead to breakage of the shaft. Such embodiments are therefore adequately stable and wear-resistant only for lighter-weight machines and lighter-weight insertable tools.
Swiss Patent CH 429 630 also discloses an impact drill head as an insertable tool, mounted on the end of a drill rod linkage for large drilling tools. Its tool shaft is embodied as a splined shaft, but for axial locking a chord-like recess that weakens the core of the shaft is provided for receiving a locking body inserted at the drill head holder. Once again, this embodiment leads to weakening of the drill head and to an impairment of the shock waves during operation.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved insertable tool for an electrical machine, especially a hand-held machine for drilling and/or impact operations, of the above-described kind, having a greater impact resistance and reduced wear than prior art insertable tools.
This object and others which will be made more apparent hereinafter are attained in an insertable tool for an electrical machine having a tool shaft insertable into a tool holder of the machine and including means for rotary driving of the tool shaft and axial locking of the tool shaft in the tool holder.
According to the invention the tool shaft has a cylindrical end portion at an end of the tool shaft inserted in the tool holder and the tool shaft is provided with a round core cross section not weakened or reduced at any point along the tool shaft up to the end of the tool shaft. The means for rotary driving and axial locking include a plurality of longitudinal struts for torque transmission and axial guidance extending from the tool shaft beyond the round core cross section and distributed uniformly around the tool shaft circumference. At least one longitudinal strut has a shoulder or front end face for axial locking and the longitudinal struts merge with the core cross section in front of the cylindrical end portion.
It is another object of the present invention to provide an improved tool holder for this insertable tool in the electrical machine, which also has greater impact resistance and reduced wear in comparison to prior art tool holders.
According to the invention the tool holder includes a receiving sleeve for the tool shaft of the insertable tool and the receiving sleeve has a front portion with a smooth interior surface for sealing and guidance and another portion located behind the front potion in a tool insertion direction. Radially inwardly protruding cleats for rotary driving the tool are located in the another portion, which engage between the longitudinal struts of the insertable tool; and at least one locking body that is radially movable between a locking position
REFERENCES:
patent: 4107949 (1978-08-01), Wanner et al.
patent: 4131165 (1978-12-01), Wanner et al.
patent: 5028057 (1991-07-01), Wanner
patent: 5076371 (1991-12-01), Obermeier et al.
patent: 5340245 (1994-08-01), Bloechle et al.
patent: 5427481 (1995-06-01), Selb et al.
Fehrle Siegfried
Haerle Vinzenz
Kageler Sven
Mueller Rolf
Howell Daniel W.
Robert & Bosch GmbH
Striker Michael J.
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