BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view of a handheld electrical right-angle power sander;
FIG. 2 is a detail in perspective of the right-angle power sander of FIG. 1, with one embodiment of a damping element;
FIG. 2
a shows a detail of the right-angle power sander of FIG. 2;
FIG. 3 is a detail in perspective of the right-angle power sander of FIG. 1, with a further embodiment of a damping element;
FIG. 4 is a detail in perspective of the right-angle power sander of FIG. 1, with a further embodiment of a damping element;
FIG. 5 is a detail of a further embodiment of the right-angle power sander of FIG. 1;
FIG. 6 is a detail in perspective of the right-angle power sander of FIG. 1, with a further embodiment of a damping element and of an adjusting element;
FIG. 7 is a detail in perspective of the right-angle power sander of FIG. 1, with an inner housing and an outer housing in the region of the handle;
FIG. 8 is a detail in perspective of the right-angle power sander of FIG. 1, with an inner housing and an outer housing in the portion of the handle;
FIG. 9 is a detail in perspective of the right-angle power sander of FIG. 1, with an inner housing and an outer housing in the portion of the handle;
FIG. 10
a is a detail in perspective of the right-angle power sander of FIG. 1, with an inner housing and an outer housing in the portion of the handle;
FIG. 10
b is a detail of the right-angle power sander of FIG. 10a with the inner housing and the outer housing, in the installed state;
FIG. 11 is a detail of the right-angle power sander of FIG. 1 with the inner housing and the outer housing, in a portion of the handle;
FIG. 12 is a detail of the right-angle power sander of FIG. 11, showing the outer housing in perspective.
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. In the embodiment shown, the right-angle power sander 10 includes three housing parts: a first housing part 11 for receiving an electric motor (not shown), among other elements; a second housing part 12 for receiving a gear (not shown), among other elements; and a third housing part 13, which is embodied as a handle 15. A drive shaft that can be driven by an electric motor is coupled to a driven shaft 16, via a gear that comprises a driving gear wheel and a driven gear wheel. A sanding wheel 14 is located on the driven shaft 16 in a manner fixed against relative rotation. The electric motor is switched on and off by the user via an ON/OFF switch 19.
FIG. 2 shows a schematic detail of the right-angle power sander 10 of FIG. 1. The first housing part 11 is embodied in one piece with the third housing part 13 that is embodied as a handle 15. The housing parts 11 and 13 are double-walled, with an inner housing 21 and an outer housing 23. The inner housing 21 and the outer housing 23 are spaced apart from one another, so that between them an interstice 25 in the form of a gap is formed. Between the inner housing 21 and the outer housing 23, at least one damping element 31 for vibration decoupling is provided according to the invention. In the embodiment shown in FIG. 2, two annular damping elements 31 of elastic material extend all the way around the circumference of the right-angle power sander 10. For greater clarity in FIG. 2, some parts of the annular damping elements 31 have been cut away. Two encompassing grooves 22 are made in the inner housing 21, for receiving the damping elements 31. The sectional view in FIG. 2a further shows that the outer housing 23, on its inner face 26, to both sides of the damping element 31, has encompassing ribs 24, which likewise receive the damping element 31. The groove 22 and the ribs 24 thus allow the damping element 31 to be received in form-locking fashion.
The damping elements 31 shown in FIG. 2, comprising an elastic material, may alternatively be embodied as damping cushions that are filled with a fluid.
FIG. 3 shows an alternative embodiment as well as an alternative location of a damping element. The damping element is a damping cushion 32 that is filled with a fluid, that is, a gas, or a liquid. The schematic illustration in FIG. 3 shows a damping cushion 32 which extends all the way around the circumference and which in the region of the first housing part 11 fills up substantial portions of the interstice 25 between the inner housing 21 and the outer housing 23 in the longitudinal direction of the right-angle power sander 10. For greater clarity, some of the damping cushion 32 is cut away in FIG. 3 as well. It can also be seen from FIG. 3 that for form-locking receiving of the damping cushion 32, grooves 22 are again made into the inner housing 21. It can furthermore be seen in FIG. 3 that at least in the region of the housing part 11 where the damping cushion 32 is provided, the interstice 25 is not the same size throughout. In the longitudinal direction between the grooves 22, the inner housing 21 is curved, and as a result the interstice 25 near the grooves 22 is larger than in the middle between the two grooves 22. The damping cushion 32 compensates for the variously sized interstice 25. In this way, an amplified vibration damping can be attained purposefully in some regions. A fluid-filled damping cushion 32 is especially well suited for this, since the fluid in the damping cushion 32 distributes itself over the existing space accordingly.
The damping cushion 32 shown in FIG. 3 may alternatively be embodied as a damping element of an elastic material.
In FIG. 4, a further embodiment of a damping element is shown. In the region of the first housing part 11, a plurality of spring elements 33, in the form of leaf springs, are located in the longitudinal direction of the right-angle power sander 10 in the interstice 25 between the inner housing 21 and the outer housing 23. On their ends, the spring elements 33 are received in encompassing grooves 22 of the inner housing 21 and are joined to the inner housing 21. Approximately halfway along the length of the spring elements 33, the spring elements 33 rest on the inner face 26 of the outer housing 23.
In the embodiment of the right-angle power sander 10 shown in FIG. 5, the outer housing 23 comprises two half-shells, which are placed on one another in the longitudinal direction of the right-angle power sander 10 and are joined with the aid of retaining elements 27, shown here in the form of retaining tabs. The retaining elements 27 connect the half-shells of the outer housing 23 without contacting the inner housing 21. The decoupling of the inner housing 21 and the outer housing 23 is thus assured with the retaining elements 27 as well. The retaining elements 27 may be separate components, as shown in FIG. 5, or may be embodied in one piece with one of the half-shells. In the region of the retaining elements 27, the half-shells of the outer housing 23 have corresponding recesses 28 for receiving the retaining elements 27, so that the retaining elements 27 are flush with the outer face 29 of the outer housing 23, rather than sitting on top of the outer housing 23. The retaining elements 27 may be joined to the half-shells of the outer housing 23 via screws or via detent elements, for instance. Moreover, the retaining elements 27 may be embodied in such a way that the initial tension of the damping element (not shown here) located between the inner housing 21 and the outer housing 23 is variable.
Unlike what is provided in the embodiment shown in FIG. 5, the half-shells of the outer housing may also be joined to one another and connected to one another (not shown) in a transverse axis of the right-angle power sander 10 as well.
FIG. 6 first shows a further embodiment of a damping element, in the form of spring elements 34 which are embodied in one piece with the inner housing 21. The spring elements 34 take the form of leaf springs, whose first end 34a is integrally formed onto the inner housing 21 and whose second, free end 34b rests on the inner face 26 of the outer housing 23. The spring elements 34 are provided in the region of the first housing part 11. Alternatively or in addition, such spring elements may also be provided (not shown) in the region of the third housing part 13 embodied as a handle 15.
FIG. 6 also shows an adjusting element 41, with which the initial tension of the damping elements, in this case the spring elements 34, can be adjusted. With the aid of the adjusting element 41, via the pressure plate 43 that is connected to the outer housing 23, a contact pressure can be exerted on the outer housing 23, as a result of which the outer housing 23 is pressed against the spring elements 34. The adjusting element 41 may for instance be a screw, which can be adjusted by the user of the right-angle power sander 10.
Between the first housing part 11 and the second housing part 12, a further damping element 39 is also provided, in the form of an encompassing damping ring of an elastic material.
In the embodiment of the right-angle power sander 10 shown in FIG. 7, the double-walled housing comprising the inner housing 21 and the outer housing 23 is limited to the third housing part 13, that is, to the handle 15. The inner housing 21, in the embodiment shown, is embodied in one piece with the first housing part 11. The damping element 31, here comprising elastic material, provides for the decoupling of the inner housing 21 and the outer housing 23. It is located annularly in the interstice 25 and is received in form-locking fashion between annular ribs 44 on the inner housing 21. Moreover, in the region between the first housing part 11 and the third housing part 13, an annular, encompassing damping element 38 is provided, which is received in an annular groove 45. The outer housing 23 is provided with a collar 46, which is surrounded by the damping element 45 in such a way that no contact is made with the outer housing 23 and the inner housing 21. The form lock between the inner housing 21 and the inner housing 23 serves to secure the connection between the housing parts 21 and 23 in the event of failure of the damping element 44.
FIGS. 8 and 9 show further embodiments of vibration damping in the region of the third housing part 13, embodied as a handle 15. In this case, only in a portion 17 of the handle 15 is the housing constructed from an inner housing 21 and an outer housing 23. This portion 17 forms the resting face for the hand of the user of the right-angle power sander 10. Only in this portion 17 is the inner housing 21 surrounded by a shell-like outer housing 23 and provided with a damping element located between them. In FIG. 8, a damping element 31 of elastic material is shown, which may alternatively be a fluid-filled damping cushion. In FIG. 9, conversely, a damping element in the form of spring element 33 is shown. The spring element 33 takes the form of a leaf spring. The inner housing 21 is provided with tabs 47, which fix the spring element 33 to the inner housing 21. The outer housing 23 is likewise is provided with tabs 48, which are engaged on the inside by the free ends 33b of the spring element 33. This makes a vibration-damped connection possible between the inner housing 21 and the outer housing 23 via the spring element 33.
In FIGS. 10a and 10b, the handle 15, as in FIGS. 8 and 9, is likewise equipped with a double-walled housing comprising an inner housing 21 and an outer housing 23 in only a portion 17, which is provided as a resting face for the user's hand. For vibration damping between the inner housing 21 and the outer housing 23, detent elements 35 in the form of resilient tongues with detent hooks are formed integrally in one piece onto the inner face 26 of the outer housing 23. The inner housing 21 is correspondingly equipped with tabs 53, so that the detent hooks of the detent elements 35 engage the tabs 53 from behind. The vibration properties may be varied by means of the choice of material, position, length, cross section, and so forth of the detent elements 35 and of their counterparts, that is, the tabs 53.
In a further embodiment in FIG. 11, the handle 15, as in FIGS. 8 and 9 as well as 10, is again equipped with a double-walled housing comprising an inner housing 21 and an outer housing 23 in only one portion 17, intended as a resting face for the user's hand. For vibration damping, the inner housing 21 and the outer housing 23 are joined together via struts 36. The struts 36 may be embodied either in one piece with the inner housing 21 or in one piece with the outer housing 23. In a simple embodiment, the struts 36 are integrally formed in one piece onto both the inner housing 21 and the outer housing 23.
FIG. 12, finally, shows how vibration can additionally be reduced by means of recesses 55 in the outer housing 23. The recesses 55 are provided in the region of the third housing part 13 that serves as a handle 15. By means of such recesses 55, the propagation of vibration along the handle 15 can be reduced.
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.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
Patent Application
20070295522
