Electrical hand tool device
The invention concerns an electric hand tool device, in particular, a percussion drill or a drill hammer, comprising a spindle (10) that can be driven by a drive motor and cooperates at one end (12) with a tool support, and a percussion means (24) for axially moving the spindle (10) in a percussion position, wherein an adjusting means (42) is provided for adjusting the spindle (10) between the percussion position and a rotary position, the adjusting means (42) comprising a switch ring (44) which is disposed on the spindle (10) and has cam configurations (46,48) on both end faces thereof, wherein one of the cam configurations (46) can engage in a corresponding cam configuration (52) which is fixed to the housing through turning the switch ring (44), and the second cam configuration (48) can be brought into engagement with a corresponding cam configuration (60) of a pressure piece (54) which can be axially moved on the spindle (10), in order to adjust the percussion means (42) to a percussion position.
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This application claims Paris Convention priority of EP 06 005 591.0 filed Mar. 18, 2006 the complete disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTIONThe invention concerns an electrical hand tool device, in particular, a percussion drill or a drill hammer, comprising a spindle that can be driven by a drive motor and which cooperates at one end thereof with its tool support, and with a percussion means for axially moving the spindle in a percussion position, wherein an adjusting means is provided for adjusting the spindle between the percussion position and a rotary position.
Electric hand tool devices, in particular, percussion drills and drill hammers which have both a percussion position of the spindle, in which the spindle performs an axial translatory motion, and a rotary position, wherein the spindle only executes a rotary drive, have an adjusting means between the two positions. In principle, a combined percussion/rotary position may also be provided, in which the spindle is driven both in a rotary and percussive fashion.
A hand drill of this type comprising a means for switching between the operation modes of drilling and percussion drilling is disclosed e.g. in EP 0 755 756 B1, in which the drill spindle is supported against an axial bearing in the rotary drill operating position, wherein the axial bearing is designed as a rolling bearing and the adjusting instrument acts on the drill spindle via this rolling bearing.
A further embodiment of a corresponding drill is disclosed e.g. in EP 0 399 714 B1 which concerns a force-operated drill, comprising a operation mode changing mechanism for changing the mode of operation of the drill between one mode of operation without percussion drilling and one mode of operation with percussive drilling, wherein the mechanism for changing the modes of operation contains a first rigid and a second elastic component.
It is the underlying purpose of the present invention to present an electric hand tool device, whose adjusting means provides a maximum adjusting path in order to also provide a sufficient adjusting path for percussion means with large notch depression.
SUMMARY OF THE INVENTIONThe invention solves this object with an electric hand tool device of this type, wherein the adjusting means comprises a switch ring which is disposed on the spindle and has cam configurations on both end faces, wherein one of the cam configurations can engage into a corresponding cam configuration, which is fixed to the housing, through turning the switch ring, and a second cam configuration can be brought into engagement with a corresponding cam configuration of a pressure piece which can be axially moved on the spindle, in order to adjust the percussion means into a percussion position.
The spindle may thereby exercise axial motion due to engagement of the switch ring in the area of its cam configuration with a cam configuration which is fixed to the housing. This axial motion is blocked in the non-engaged state due to mutual abutment of the cam configurations. A further axial motion is thereby possible, such that the cam configuration of the pressure piece is immersed into a second cam configuration of the switch ring, thereby doubling the axial lift of the spindle.
In this fashion, a corresponding adjustment means can be provided with little construction effort even in electric hand tool devices comprising a percussion means, which require a large axial spindle lift. The engagement between the cam configuration of the switch ring and the cam configuration of the housing is thereby effected by turning the switch ring, such that the curves engage each other through radial rotation.
This double engagement between the switch ring and the cam configuration which is fixed to the housing, and between the pressure piece and the switch ring provides large axial travel of the spindle, thereby realizing a switching process, with which two radial cams of a percussion means can come into engagement with each other.
In a particularly advantageous fashion, the pressure piece may thereby cooperate with a spring which loads the pressure piece away from the switch ring. I.e. the radial cams of the pressure piece and the switch ring are not engaged in the normal basic position. When e.g. the drill of a corresponding percussion drill is put onto a workpiece to be processed, the spindle is axially loaded against the spring force and moves in the axial direction until the radial cams of the percussion means engage with each other and the cam configurations are immersed into each other between the switch ring and the pressure piece, such that when the electric hand tool device is correspondingly switched, percussive or percussion drilling operation is possible, since the spindle can be moved in an axial direction.
When the spindle is no longer axially loaded, e.g. by removing the electric hand tool device from the workpiece, there is no remaining percussive motion of the spindle. In this fashion, an electric hand tool device of this design is much more easy to hold.
The side of the pressure piece opposite the cam configuration may moreover be supported against an axial bearing of the spindle. The axial bearing serves to guide the spindle in the rotary position.
The pressure piece may thereby be preferentially guided in a crank guidance, such that the pressure piece cannot be rotated but perform only a purely translatory motion relative to the housing.
A slide switch may moreover be provided as a switch for the adjusting means, which is provided on the outside on a housing of the electric hand tool device. It may perform e.g., in particular, a radial sliding motion which rotates the switch ring.
Further advantages and features of the invention can be extracted from the other application documents. The invention is explained in more detail below with reference to the drawing.
The spindle is rotatably disposed in a machine housing 16 via bearings 18, 20 and 22.
The electric hand tool device comprises a percussion mechanism which is designated in total with reference numeral 24. The percussion mechanism 24 has substantially two elements, i.e. the component 26 with a first radial cam 28 and a beater 30 with a second radial cam 32. The two radial cams 28 and 32 of the components 26 and 30 face each other.
The component 26 is thereby pressed onto the spindle 10 and axially abuts a stop 34. The component 26 rotates with the spindle and is axially fixed thereto.
The beater can move axially relative to the spindle 10, but cannot rotate relative to the housing 16. The beater 30 is guided in a beater housing 36 which is inserted and fixed in the machine housing 16.
A spring 40 is also guided in the beater housing 36 and is supported on one side against the beater 30 and on its other side against the beater housing 36, thereby pretensioning it.
The radial cams are thereby designed such that at least one of the radial cams has a control cam which axially projects towards the other radial cam past the rest of the radial cam. Run-up faces are moreover provided, which permit sliding of the two radial cams on top of each other, thereby permitting overlooking of the control cams provided on one or both radial cams. So-called depressions are provided between the two control cams.
When the two radial cams 28 and 32 engage each other through pressing a tool onto a workpiece to be processed (
In order to permit switching from one percussion position to a rotary position and vice versa, an adjusting means is provided at the spindle end opposite to the tool support, which is in total designated by reference numeral 42. The adjusting means 42 comprises an adjusting instrument (not shown), in particular, a slide switch that can be displaced in a radial direction and through which an operator introduces and performs the switching process. A switch ring 44, which has cam configurations 46 and 48 on both end faces, is radially moved relative to the housing through actuating the slide switch, wherein the cam configuration 46 can be brought into engagement with a cam configuration on a component 50 which is fixed to the housing, whose cam configuration is designated with 52. In
When the adjusting ring is placed into the position shown in
An arrangement as shown in the above figures is advantageous in that the cam configurations 46 and 52 and the cam configurations 48 and 60 engage each other in such a manner as to provide a relatively large lift for the spindle 10 (clearly visible in
The invention increases the lift motion without changing the operation of a slide switch.
Claims
1. An electric hand tool device, a percussion drill, or a drill hammer, the device comprising:
- a housing;
- a drive motor disposed in said housing;
- a spindle cooperating with said drive motor and having an end for engagement with a tool support;
- percussion means cooperating with said spindle for axially displacing said spindle in a percussion mode;
- a first cam fixed to said housing;
- a pressure member having a second cam, said pressure member structured for axial displacement along said spindle;
- and
- a switch ring disposed on said spindle, said switch ring having a third cam on a first end face thereof and a fourth cam on a second end face thereof, said switch ring being structured for turning to bring said third cam into engagement with said first cam and said fourth cam into engagement with said second cam, wherein said switch ring is turned from a rotary position into a percussion position.
2. The electric hand tool device of claim 1, further comprising a spring cooperating with said pressure member to urge said pressure member away from said switch ring.
3. The electric hand tool device of claim 1, wherein said spindle has an axial bearing supporting said pressure member at a side thereof opposite to said second cam.
4. The electric hand tool device of claim 1, wherein said pressure member is guided in a cam such that it cannot be rotated relative to said housing.
5. The electric hand tool device of claim 1, further comprising a slide switch for rotating said switch ring.
Type: Application
Filed: Feb 28, 2007
Publication Date: Sep 20, 2007
Applicant: Metabowerke GmbH (Nuertingen)
Inventors: Guenther Stark (Frickenhausen), Mathias Naumann (Unterensingen)
Application Number: 11/711,707
International Classification: E02D 7/02 (20060101);