BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows one embodiment of a hand power tool of the invention in plan view;
FIG. 2
a shows one embodiment of the sealing and/or damping element in an exploded view;
FIG. 2
b shows the sealing and/or damping element of FIG. 2a in perspective;
FIG. 3 shows two half shells, forming the housing of the hand power tool of FIG. 1, in plan view;
FIG. 4 is a detail in perspective of the housing of the hand power tool of FIG. 1;
FIG. 5 is a detail in a plan view on the housing of the hand power tool of FIG. 1;
FIG. 6 is a detail of a different embodiment of the hand power tool of the invention, in cross section.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the embodiment shown in FIG. 1, the hand power tool 1 of the invention is a rotary percussion screwdriver. The housing 10, of plastic and in particular thermoplastic plastic, comprises two half shells 12 (FIG. 3), which are placed against one another in form-locking fashion in a longitudinal axis of the hand power tool 1 along the joining region 17 (FIG. 4) and are joined together by screws (not shown). The housing 10 forms a pistol-like grip 14, a lower part 13 angled relative to the grip 14, and an upper part 15 that substantially forms a T shape with the grip 14. An on/off switch 16 in the form of a push button is located in the region of the grip 14. The upper part 15 receives the electric motor 30 (FIG. 6), among other elements. A rechargeable battery 11 for supplying voltage is mounted on the underside of the lower part 13. In the front region of the upper part 15, in a transverse axis of the hand power tool 1, a gearbox 20 of metal is flush with the housing 10 and is detachably joined to the housing 10 with screws 22.
The region where the gearbox 20 is located on the housing 10 and joined to it will also be referred to here as the joining region 21. The gearbox 20 serves to receive a gear (not shown) that is connected to the electric motor 30. In the front region, the gearbox 20 is equipped with a chuck 24 for receiving a tool insert 25. In FIG. 1, regions 7 can also be seen on the outside of the housing 5 in which a thermoplastic elastomer is integrally injected onto it to make a soft grip for enhancing the resistance to slipping and improve the grip. The regions 7 may be integrally injected separately or joined together by causing the thermoplastic elastomer to pass inward into the housing 5 through bores (not shown) and emerging to the outside again at one or more other points 7, again through bores in the housing 5.
FIG. 2
a shows a sealing and/or damping element 40, which comprises two half rings 42, in an exploded view, while FIG. 2b shows the annular sealing and/or damping element 40 in the put-together form. As can be seen in FIG. 3, each of the two half rings 42 is received in one housing half shell 12. When the two half shells 12 are put together, the two half rings 42 also joined together and thus in the assembled state form one annular sealing element 40.
The half rings 42 that form the sealing element 40 are introduced into the housing half shells 12 in the joining region 21 by injection molding. The half rings 42 are each injected into one receiving groove 18 (FIG. 4) of the half shells 12. To strengthen the form lock between the sealing element 40 and the half shell 12, the receiving groove 18 is embodied in profiled form at least in part. Accordingly, the inside of an outer face 46, facing toward a half shell 12, of a half ring 42 likewise at least partially has a profiled structure, for instance in the form of grooves 47.
In the embodiment shown in FIGS. 2a and 2b, each of the two half rings 42 is embodied in two parts, so that each half ring 42 comprises two joined-together half rings 43 and 44. This has the advantage of saving material, since thermoplastic elastomer is integrally injected only where it is necessary for the sake of sealing and/or damping purposes. If each of the half rings 42 are formed in one piece of two (or more) half rings 43, 44, this has the advantage that in the most favorable case, only one integral injection point for one two-part (or multiple-part) half ring 42. In FIGS. 4 and 5, it can be seen that the sealing element 40 with the two half rings 43 in the joining region 21 between the housing 10 and the housing part 20 forms one encompassing sealing ring. The two half rings 44, in the embodiment shown, are located such that they serve the purpose of damping the gear and sealing off the gear compartment from the motor compartment. The inside faces of the half rings 44 contact a gear, not shown, such as a ring of a planetary gear, in such a way that the gear is supported in a vibrationally damped way.
One of the two half rings 42 has a piece 45 that extends in the longitudinal direction of the hand power tool 1 between the half rings 43, 44. In the assembled state, this portion 45 extends along the longitudinally extending joining region 17 between the two half shells 12 and thus additionally seals off the joining region 17 in the joining region 21 between the housing 10 and the gearbox 20.
The embodiment shown in FIGS. 2a and 2b of a sealing and/or damping element 40 shows an additional function of the sealing and/or damping element 40. The sealing element 40 additionally takes on the function of a slip prevention element. To that end, at least one housing half shell 12 has an opening 19, through which the sealing element 40 reaches far enough that the sealing element 40 protrudes out of the housing 10. The sealing element 40 protrudes far enough out of the housing 10 that informs the highest elevation, that is, the highest point or highest surface, relative to the housing 10.
In this way, the sealing element 40 forms a contact face 48 for the hand power tool 1 when the hand power tool 1 is set down on one of its side faces on a surface. When the hand power tool 1 is lying on its side, the sealing element 40 thus additionally serves as a slip prevention element, since it prevents the hand power tool 1 from slipping if it is on a slanting surface. To enhance the resistance to slipping still further, grooves 49 are provided on the contact face 48, in the embodiment of the sealing element 40 shown.
In a further feature shown in FIG. 6, a sealing and/or damping element 50 is located in the housing 10 in the region of the electric motor 30, in particular in the region of a bearing 32 of the armature shaft 34 of the electric motor 30. The sealing and/or damping element 50 is likewise integrally molded into the housing half shells 12 of a thermoplastic elastomer by injection molding. As FIG. 3 shows, one half ring 52 is integrally injected into each of the two half shells 12. Upon joining of the two half shells 12 along the longitudinal axis, the two half rings 52 together make one substantially annular sealing and/or damping element 50.
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
20070256847
