Abrading – Frame or mount – Portable abrader
Reexamination Certificate
2001-01-10
2003-02-04
Eley, Timothy V. (Department: 3723)
Abrading
Frame or mount
Portable abrader
C451S354000, C451S453000, C451S456000
Reexamination Certificate
active
06514131
ABSTRACT:
PRIOR ART
The invention is based on a power tool having a dust suction device integrated into its housing.
U.S. Pat. No. 5,467,835 has disclosed a hammer drill with a dust box and a fan attached to it which can suck drilling dust produced into the dust box. The suction air generated by the fan enters a suction conduit in the vicinity of the tool and is conveyed via this conduit into the dust box. In the box, the suction air passes through a dust filter embodied as a folded filter which separates out the drilling dust that collects in the dust box. The dust box has a bottom that pivots up for the removal of the folded filter and for the emptying of the drilling dust and is disposed together with the fan in a common housing that can be connected to the hammer drill by means of a relatively complex coupling.
The dust box of the known hammer drill can only be emptied with relative difficulty, and changing the folded filter is complicated. Furthermore, this dust box is unsuitable to be fastened in a self-supporting way to power tools with integrated dust suction for blow injecting the dust.
There are also known power tools with plastic cassettes used as dust boxes which can either be provided—like a reduced-scale grass-catcher for lawnmowers—with a multitude of air openings and lined with smooth-walled filter material or which are comprised of a porous, air-permeable plastic which cleans the air that blows the dust in and allows it to escape from the container while the dust is retained. These plastic cassettes have a tendency to permit fine dust to pass through, have a tendency to clog up, and are difficult to empty and clean.
ADVANTAGES OF THE INVENTION
The power tool with dust removal according to the invention has the advantage over the prior art that a very lightweight and rugged dust box is produced which has a particularly large filter surface area with a high degree of air permeability and improved fine dust filtration. Furthermore, because the dust box has a number of covers, it can be emptied more easily and in a more environmentally sound manner than dust boxes with only one cover.
Since the at least one cover is coupled in drawer fashion to the side walls of the dust box, the dust box can be opened in a particularly gentle manner so that the dust cannot be undesirably agitated or spilled.
Since the dust box is embodied as a skeletal body and its walls are embodied as covers which close in a dustproof manner and can be used in a detachable fashion and the air escape openings also have a folded filter, the air permeability is further improved while dust filtration is assured, wherein filter surfaces can be arbitrarily cleaned or replaced independently of each other.
Since at least one of the covers is coupled to the dust box by means of hinges, it can be opened in a controlled, gentle manner similar to the drawer-like embodiment. This prevents an undesirable spilling of dust.
Since the filter lamellas of the folded filter are disposed lateral to the longitudinal axis of the dust box, the incoming dust-laden air can be influenced so that a relatively low amount of turbulence and therefore a high vacuum action on the work piece being machined is assured.
Since dust baffles are disposed lateral to the longitudinal axis of the dust box, supported by side walls of at least one of the covers, the turbulence of the incoming dust-laden air is counteracted further so that the efficiency of the suction removal is further improved.
Since one of the side walls or the bottom part of the dust box is transparent at least in some areas, the fill level of the dust box can be monitored optically in much the same way as with a viewing glass.
Since only the covers respectively have a filter, in particular a folded filter, and as the only part of the dust box with air openings, the filter surface area can be dimensioned as particularly large. As a result, there is only a slight buildup of dust-laden air and the efficiency of dust suction removal is high. In addition, starting at a particular layer thickness, the dust can as a result automatically detach from the folded filter and under the influence of gravity, can fall into the dust box, from which it can easily be emptied.
Since the surface of the dust box supporting the cover is inclined in relation to the incoming air in such a way that the dust box tapers in a wedge shape toward the machine, dust-minimized flow conditions are produced which further improve the dust removal.
Since the cover is elastically affixed to the dust box in a sealed fashion, it is particularly easy to open and can easily be reclosed securely.
Since sealing lips are disposed in the inlet fitting of the dust box and engage in a sealing manner with the dust ejection fitting of the power tool, the dust box is coupled to the power tool in a reliable, dustproof manner.
Since the folded filter is disposed in cover-like parts of the dust box, it is particularly easy to replace due to the fact that it is either newly glued in place or the entire cover with the filter is replaced.
Since the dust box can be fastened to the power tool with detent locking means, it can be detached, emptied, and refastened in a particularly easy, reliable, time-saving manner.
Since the inlet fitting of the dust box can be closed by means of a valve, an undesirable escape of dust can be effectively prevented when the dust box is detached from the power tool.
REFERENCES:
patent: 5349752 (1994-09-01), Stirm
patent: 5467835 (1995-11-01), Obermeier et al.
patent: 6047693 (2000-04-01), Yamami et al.
patent: 6139411 (2000-10-01), Everts et al.
patent: 27 05 388 (1978-08-01), None
patent: 44 38 549 (1995-05-01), None
patent: 198 31 383 (2000-01-01), None
patent: 0 558 253 (1993-09-01), None
patent: 0 752 240 (1997-01-01), None
Reich Doris
Wuensch Steffen
Eley Timothy V.
Grant Alvin J.
Robert & Bosch GmbH
Striker Michael J.
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