BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view of a hand-guided electric right-angle power sander;
FIG. 2 is a detail of the right-angle power sander of FIG. 1, with a damping element in a first embodiment;
FIG. 2
a is an enlarged detail of the connection region of the two housing parts of the right-angle power sander of FIG. 2 in cross section;
FIG. 3 is a detail of the right-angle power sander of FIG. 1, with a damping element in a second embodiment;
FIG. 4 is a detail of the right-angle power sander of FIG. 1, with a damping element in a third embodiment;
FIG. 5 is a detail of the right-angle power sander of FIG. 1, with a damping element in a fourth embodiment;
FIG. 5
a is an enlarged detail of a further embodiment of a damping element, analogous to FIG. 5;
FIG. 6 is a detail of the right-angle power sander of FIG. 1, with an additional screw connection; and
FIG. 6
a is an enlarged view of FIG. 6, with a vibration-decoupled screw connection in a first embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The right-angle power sander 10 shown schematically in FIG. 1 represents one embodiment of the hand power tool of the invention. The right-angle power sander 10 in the embodiment shown includes three housing parts: a first housing part 11 for receiving an electric motor 21, a second housing part 12 for receiving a gear 23 and a third housing part 13, which is embodied as a handle 15. The drive shaft 22 that is drivable by the electric motor 21 is coupled to the driven shaft 26 via the gear 23, which comprises a driving gear wheel 24 and a driven gear wheel 25. A sanding wheel 27 is located on the driven shaft 26 in a manner fixed against relative rotation. The electric motor 21 is switched on and off by the user via an ON/OFF switch 19.
In FIG. 2, a detail of the right-angle power sander 10 of FIG. 1 is shown. In the connection region 30 between the first housing part 11 and the second housing part 12, a damping element 31 is provided according to the invention. By means of the damping element 31, the two housing parts 11, 12 are decoupled from one another and joined to one another in vibration-damping fashion. The embodiment of FIG. 1 involves an essentially annular damping element 31, which extends all the way around, that is, along the circumference of the right-angle power sander 10, between the two housing parts 11, 12.
The damping element 31 is of an elastic material, such as an elastomer, and may be integrally formed onto the housing parts 11, 12, for instance by injection molding. This is shown as an example in an enlarged detail in FIG. 2a. In the connection region 30, the first housing part 11 is provided with a radially inward-oriented collar 16, and the second housing part 12 is provided with a likewise radially inward-oriented groove 17, such that upon integral injection molding of a thermoplastic elastomer, a damping element 31 is embodied between the two housing parts 11, 12 and is joined to the housing parts 11, 12 by form locking.
FIG. 3 likewise shows a detail of the right-angle power sander 10 of FIG. 1. In it, a second embodiment of a damping element 32 is shown. Once again, this is an essentially annular damping element 32 of an elastic material, which extends all the way around between the first housing part 11 and the second housing part 12. The vibration absorption is enhanced in the damping element 32 by the provision that the damping element 32 is profiled. The profiled damping element 32 has a folded structure, as a result of which encompassing channels are formed.
In a further embodiment shown in FIG. 4, the damping element is formed by spring elements 33. In the embodiment, four helical springs are provided as spring elements 33, distributed over the circumference between the first housing part 11 and the second housing part 12. Alternatively, still other spring elements 33 may be used, such as leaf springs or cup springs.
FIG. 5 schematically shows a further embodiment of a damping element, which is embodied as a spring element 34. Unlike the embodiment shown in FIG. 4, however, the spring element 34 is embodied integrally with the second housing part 12. The spring element 34 is formed integrally in tonguelike fashion onto the edge of the second housing part 12 in the connection region 30 and rests on the first housing part 11 in such a way that it enables vibration damping in the longitudinal direction of the right-angle power sander 10. The second housing part 12, which receives the gear 23, is for instance of metal. Accordingly, the spring element 34 shown in FIG. 5 is likewise of metal. Alternatively or in addition, one or more spring elements may be integrally formed in one piece onto the first housing part 11 in a similar way (not shown).
As shown in FIG. 5a, the two housing parts 11, 12 may alternatively be embodied in overlapping fashion in the connection region 30, by providing that the peripheral region 14 of the second housing part 12 is reshaped radially inward in such a way that in the connection region 30, the two housing parts 11, 12 are located parallel to one another. The radially inwardly reshaped peripheral region 14 of the second housing part 12 may be equipped in one piece with spring elements 34 that rest against the inner face of the first housing part 11 in the peripheral region 18 of the first housing part 11.
Analogously, the peripheral region 18 of the first housing part 11, which overlaps the reshaped peripheral region 14 of the second housing part 12, may be provided with radially inward-oriented spring elements, which are formed integrally in one piece onto the housing part 12 and in the reshaped peripheral region 14 rest on the second housing part 12 (not shown). The spring elements 34 may also be embodied in tonguelike fashion, similarly to the embodiment shown in FIG. 5. The spring elements 34 of FIG. 5a allow vibration damping in the radial direction of the right-angle power sander 10.
In FIG. 6, shown schematically, the two housing parts 11, 12 are decoupled from one another, for instance by a damping element 31 of an elastic material, and are additionally joined to one another by a vibration-damped screw connection 38. The vibration-decoupled screw connection 38 is shown enlarged in FIG. 6a. In the region of its head, the screw 38 is surrounded by a sleeve 39 of an elastic material. The elastic sleeve 39 may also be embodied in one piece with the damping element 31.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the type described above.
While the invention has been illustrated and described as embodied in a hand power tool, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
Patent Application
20070295521
