The present invention relates to a motor-driven machine tool, in particular a hand-held power tool having a rotatably driveable tool, according to the preamble of claim 1.
A machine tool of this type is known as a battery-operated, hand-held power tool from DE 199 51 264 A1 in the embodiment shown in
The object of the present invention is to design a machine tool, in particular a hand-held power tool of the type described initially, having a compact design, in a manner that is easy to produce and assemble.
This object is achieved according to the present invention having the features of claim 1. The dependent claims describe expedient developments.
In the solution according to the present invention, which is also advantageous for use, in particular, with hand-guided machines tools which are designed as screwdrivers, the displaceable support of the tool-changing magazine on the drive unit results in a compact and easily assembled design which makes it possible to create a narrow, easy-to-handle machine housing, even in the shank region of pistol-shaped machine housings of hand-held power tools. This is combined with a relative large diameter of the tool-changing magazine, thereby making it possible to provide a large number of tool chambers.
In the solution according to the present invention, the tool-changing magazine is preferably displaceably supported via the transmission, on the drive unit which includes the transmission and the motor.
When the tool-changing magazine is designed as a drum magazine, it has proven particularly advantageous to provide rotatable support of the drum magazine relative to the drive unit, in particular its transmission. For this purpose, the transmission may be provided with a transmission neck which is enclosed by the drum ring of the drum magazine, in which the tool chambers are located, the transmission output shaft extending through the drum magazine. Given a spacially compact design of the transmission, it is therefore possible to support the transmission output shaft in the transition region to the transmission neck, or inside the transmission neck.
In combination with an embodiment of the transmission as a planetary gearset in particular, it is possible to realize a design which is also very short, in the case of which the support of the transmission output shaft and the drum magazine may be realized in regions which are axially adjacent to one another or even overlap one another.
It is therefore possible to attain a stable support of the transmission output shaft using an embodiment that is not so large that machine handling is affected.
In order to favorably support the intermediate transmission which connects the transmission output shaft to the tool fitting, the transmission output shaft may be supported in the region of its free end opposite the transmission in a bearing plate which also provides support for the tool fitting. The tool fitting is preferably structurally integrated in one of the wheels of the intermediate transmission, the other wheel of which is mounted, as a driving wheel, on the transmission output shaft, the intermediate transmission being situated, in all, and in a space-saving manner, between this bearing plate and the tool-changing drum, and by the transmission neck which is enclosed by the tool-changing drum.
This design makes it possible to design the actuating element—which is provided to move a particular tool between a tool chamber of the drum magazine and the tool fitting—as an actuating slide, in the form of an actuating rod which preferably extends—parallel to the main axis of the machine which coincides with the axis of the drive unit—through the transmission housing, on the circumferential side of the transmission housing, thereby also supporting the forces which act on the actuating slide on the drive unit, and in particular on the transmission housing. This is significant, in particular, given that the particular tool is supported axially via the actuating slide in its operating position in the tool fitting; the bearing plate is therefore also supported indirectly via the actuating slide when it engages axially in the tool fitting, since the tool fitting is rotatably supported against the bearing plate.
The design of the actuating slide as an actuating rod makes it possible, using simple means, to support it axially in its position which provides axial support for a tool contained in the tool fitting, thereby making it possible, e.g. via a support plate which extends in the longitudinal direction of the actuating slide on the back side thereof, and which is spring-loaded in its support position which reaches behind the actuating slide, and which may be displaced in the opposite direction using a button for release. The button which is displaceable only transversely to the main axis, and the handle required to axially displace the actuating slide are preferably located in appropriate recesses in the housing of the machine, extend through them, and are situated adjacent to one another relative to the support position of the actuating slide.
The support plate is preferably clamped in a holder which is fixed in portion relative to the housing, and possibly also relative to the motor transmission unit, in a manner such that it is preloaded via spring action in its support position in which it reaches behind the actuating slide. Via the support plate, it is therefore possible to also act on the actuating slide in a frictional manner and to secure it in its position in which it is retracted from the tool fitting when the support plate bears against the circumference of the slide.
In the solution according to the present invention, it is possible, in particular, to create an assembly which extends from the motor to the tool fitting and includes the drive unit, the assembly being merely enclosed by the machine housing which is essentially used only as a cover. The machine housing may therefore be made simpler and lighter-weight in design. In the embodiment as a hand-held power tool in particular, the machine housing is designed in the shape of a pistol and includes a grip part in which an energy accumulator, in particular a rechargeable battery, and the associated control are preferably housed, the control preferably being located in the transition region between the handle and the shank of the pistol-shaped machine housing, the actuating device—which is preferably designed as a button-switch combination—also being preferably situated in this transition region in particular.
The handling of the machine according to the present invention is also simplified and made lighter-weight by the fact that the drum-type changing magazine overlaps a cut-out section of the housing in a subregion of its circumference, in particular extending beyond the circumference of the housing via one segment in the region of this cut-out section. The tool-changing magazine may therefore be displaced via direct access. An arrangement of this type, in particular in combination with a design of the machine housing which is based on the assembly which includes the drive unit and is reinforced by it, also makes it possible, as an option, to swivel the tool-changing magazine outwardly—as is known with drum revolvers—in order to load tools.
To identify the particular tools which are stored in the tool chambers of the drum-type tool-changing magazine, it is also expedient for the tool-changing magazine to be provided with markings, e.g. symbols, that identify the particular tool, on its circumferential side and overlapping the particular chamber; when the tool-changing magazine is displaced, these symbols become aligned with a viewing window in the housing. This viewing window is preferably provided with a transparent cover which is designed as a magnifying glass in particular, and is situated in the housing in longitudinal alignment with the tool fitting, thereby resulting in a placement that is simple in terms of the operating position.
A displaceable arrangement of the tool-changing magazine may also be attained within the scope of the present invention when it is supported against the drive unit using rod magazines; this magazine may be moved—possibly being displaced transversely to the main axis in and/or through the machine housing—with its tool chambers until it overlaps the tool fitting.
Further advantages and expedient embodiments are depicted in the claims, the description of the figures, and the drawing.
The embodiment of a motor-driven machine tool 1 shown in the figures is a hand-held power tool which is designed as a screwdriver, and which—when machine housing 14 is pistol-shaped in design—includes a shank part 2 which corresponds to the piston barrel. Main axis 3 extends in the longitudinal direction of shank part 2. Motor 4 and transmission 5—as part of a drive unit—are situated along main axis 3, being situated coaxially one behind the other and determining the main axis. A drum magazine, as tool-changing magazine 6, is situated on transmission 5. A tool fitting 7 is offset relative to main axis 3; in the figures, tool fitting 7 has an inserted tool which is a screwdriver insert 8 in this case and extends parallel to main axis 3. An intermediate transmission 9 is situated in the drive for tool fitting 7, the drive being carried out via motor 4 and transmission 5. An actuating element 10 which is designed as an actuating slide 11 and is actuated using handle 12 is also provided in order to load tool fitting 7 with the desired tool which is stored in tool-changing magazine 6, and to provide axial support for this tool in its operating position in tool fitting 7. Handle 12 is displaceable in a longitudinal slot 13 which extends in the direction of main axis 3, longitudinal slot 13 lying in the dividing plane of machine housing 14 which is composed of two housing halves; the axis of tool fitting 7 also lies in this dividing plane.
Machine housing 14 includes, in the region of tool-changing magazine 6 which is designed as a drum magazine, a cut-out section 15, in the region of which tool-changing magazine 6 is exposed via one segment 16, the tool-changing magazine 6 preferably extending past the outer contour of machine housing 14 via segment 16.
A viewing window 17 which may preferably be provided with a magnifier-type insert is also provided in the region of overlap with tool-changing magazine 6, thereby making it possible to easily identify symbols which characterize the tool and are provided on the circumference of drum-shaped tool-changing magazine 6. Viewing window 17 preferably overlaps the dividing plane of the housing halves of machine housing 14 and is aligned with slot 13 for handle 12 of actuating slide 11. A button 18 is situated between slot 13 and viewing window 17, upstream of handle 12.
The cross-sectional view presented in
Tool-changing magazine 6 which is designed as a drum magazine is situated in the region of neck 24; tool-changing magazine 6 includes a drum ring 25 which is concentric to the drum axis, and in which tool chambers 26 are provided which extend parallel to the drum axis and main axis 3, are preferably distributed evenly around the circumference, and to which tool symbols are assigned, the tool symbols being situated on the circumference of drum ring 25 and overlapping viewing window 17.
In an overlap position, as shown in
In its position in which it bears against a particular tool, a screwdriver insert 8 in this case, in tool fitting 7, actuating slide 11 is locked via a support lever 34 which, in the embodiment, is designed as a support plate which is held on its end opposite actuating slide 11 in a slot-shaped guide 35 which extends adjacent to motor 4. The support plate which acts as support lever 34 extends, as shown in
When support lever 34 which is designed as an actuating rod has been displaced out of the support position via the actuation of button 18, it may be passed over by actuating slide 11, preferably bearing against actuating slide 11 on the circumference, thereby securing actuating slide 11—in its retracted position in which it releases tool-changing magazine 6—via a frictional connection, and possibly via a frictional connection and in a traversable, locking manner.
In the solution presented according to the present invention, as shown in
A machine tool 1 which has a design of this type and may be manually-guided may also be used as a drill, in the case of which tool chambers 26 are used to accommodate drill bits which may be used in alternation.
Number | Date | Country | Kind |
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10 2006 059 688.9 | Dec 2006 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP07/61124 | 10/18/2007 | WO | 00 | 2/16/2009 |