EP0016771A1

EP0016771A1 - Hand mechanical tool.

Info

Publication number: EP0016771A1
Application number: EP79900542A
Authority: EP
Inventors: Karl Wanner; Manfred Bleicher
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1978-05-09
Filing date: 1979-12-05
Publication date: 1980-10-15
Also published as: EP0016771B1; DE2820125A1; PL215451A1; WO1979001041A1; DE2966493D1

Abstract

Un outil mecanique a main mu electriquement, fonctionnant en particulier comme perceuse ou engin a percussion, dans lequel un mandrin (20) rotatif et une piece de percussion a air (13) est mobile. La piece de percussion (13) comporte une gaine concentrique d'entrainement (28) qui presente une surface de guidage (30) avec courbe maximum (32) et minimum (33) axiale, cette courbe etant fermee et presentant une inclinaison qui augmente et diminue constamment. Une griffe (31) prend sur un emplacement voisin de la surface de guidage (30) a', proximite immediate du piston d'entrainement (21) du dispositif de percussion (13). Une attache (35) empeche l'agrafe (31) de se deplacer librement sans guidage le long de la surface de guidage (30). En revanche, dans le sens axial, elle est maintenue avec un degre de liberte pour le balayage d'une surface de guidage (30).An electrically driven mechanical hand tool, functioning in particular as a drill or impact device, in which a rotary chuck (20) and an air impact piece (13) are movable. The percussion piece (13) comprises a concentric drive sheath (28) which presents a guide surface (30) with maximum (32) and minimum (33) axial curve, this curve being closed and presenting an inclination which increases and constantly decreasing. A claw (31) takes on a location close to the guide surface (30) a ', immediately near the driving piston (21) of the percussion device (13). A clip (35) prevents the clip (31) from moving freely without guidance along the guide surface (30). On the other hand, in the axial direction, it is held with a degree of freedom for the sweeping of a guide surface (30).

Description

Hand tool

The invention relates to a hand-held power tool, in particular a rotary or percussion hammer, with an in particular electric drive motor, by means of which, via a gear, a rotating sleeve with the tool receptacle acted upon by it, in which a tool can be guided, can be driven in rotation, and by means of which Furthermore, a striking mechanism can be driven, which has an axially reciprocating drive piston, a striker which can be acted upon by the drive piston via an air cushion and which transmits its impact energy to the tool, and a translational drive which operates on the drive piston and which has a drive element which can preferably be driven in a rotating manner Has curve guidance and at least one driver scanning the curve guide and acting on the drive piston for its axial displacement.

Such a hand tool is known from DE-OS 24-49191. The drive motor drives a swashplate as part of the striking mechanism via a motor pinion and the gearwheel that engages with it, which sits rotationally fixed on an intermediate shaft, which in turn carries a further gearwheel which meshes with a gearwheel which sits on the rotating sleeve. The rotating sleeve in turn also has a toothing which engages in a toothing of the die holder of the tool holder for its rotary drive. Four gearwheels are therefore necessary on the transmission side, and furthermore the two further toothings on the rotary sleeve and on the associated striking die. These many gears are expensive, take up a lot of space in the machine and make them expensive, relatively large and heavy and therefore bulky. Another disadvantage of the transmission is that the cost of bearings for all of the described transmission parts is considerable, which also has an adverse effect on the price, dimensions and weight of the machine. The translation drive and its striking mechanism also have many disadvantages. The drive member is represented by the swash plate, which contains an annular groove running as a curve but transverse to the drive of the swash plate. In this groove a ring is rotatably held as a driver relative to the swash plate, which has a protruding driver pin which engages a piston pin of the drive piston. The drive piston is non-rotatably guided. This design of the striking mechanism with translation drive is very complex and leads to relatively high production costs. It also takes up a lot of space inside the machine. It also has the disadvantage that the force acting on the drive piston for its axial back and forth movement acts eccentrically on the drive piston, so that the longitudinal guidance of the piston is thereby additionally burdened and subjected to additional wear. One rotation of the swashplate as Drive element results in an axial impact on the tool. In order to achieve a high number of strokes, the swash plate must be driven at a relatively high speed. On the other hand, since the swash plate is heavily stressed, it must be designed so that it can withstand the stresses even over a long period of time. This leads to a strong and heavy design of the swash plate with a driver guided on it. This results in relatively large orbiting masses. Otherwise, this design is expensive and also requires a high weight of the machine.

The invention has for its object to provide a hand tool described above, which compared to known simpler, cheaper, compact, lighter and smaller designed and at the same time less vibration with a significantly simplified drive for the reciprocating movement of the drive piston and the tool. In particular, the number of necessary gears of the transmission and the total necessary bearings should be reduced. At the same time, the oscillating masses and thus the vibration load on the operator handling the machine are to be reduced. In everything, the advantages given by the air spring hammer mechanism and the possibility to drive the tool not only axially but also simultaneously or independently of it should be retained.

The object is achieved in a hand-held power tool of the type mentioned at the outset according to the invention in that the drive member consists of an adapter which is coaxial to the drive piston and the striker and surrounds both concentrically. Drive sleeve is that the drive sleeve has a self-contained in the circumferential direction and thereby has a substantially continuously increasing and decreasing slope with guide surface having axially directed curve maxima and curve minima, that the driver is designed as a rolling or sliding body and is adjacent to the guide surface Place engages directly on the drive piston and that the rolling or sliding body is secured against free, uncontrolled migration along the guide surface by means of a forced holder, which is preferably approximately cage-like in the direction of rotation, but is held in the axial direction with a degree of freedom for scanning this guide surface. It is advantageous if the guide surface has a sinusoidal shape, which is approximately band-shaped in the circumferential direction, or else an asymmetrical shape which deviates from a sinusoidal line.

This training creates the prerequisites for making the entire transmission and striking mechanism as simple as possible, specifically as a result of the drive sleeve, which concentrically surrounds the drive piston and racket. A special, at a radial distance from the arrangement of the drive piston and racket translational drive for the drive piston is omitted, so that the z. B. below the longitudinal central axis of the drive piston necessary space is no longer required. As a result, the machine can be made considerably more compact and smaller. In addition, it can be trained much easier and cheaper and lighter in weight. On the transmission side, it is only necessary to provide the drive sleeve with a gearwheel that meshes with a drive pinion of the drive motor. So only two gears are required. This and the concentric arrangement of the drive sleeve make it possible to minimize the number of bearings and necessary bearings. This also has a favorable effect on reducing the size, weight and price of the machine, without sacrificing the advantages of the air spring impact mechanism and the possible rotary and impacting action on the tool holder for the tool. It is also advantageous that the circulating masses are reduced and furthermore the oscillating masses can be kept as small as possible, so that a low vibration load for the operator handling the machine can thereby be achieved. The forced support for the rolling or sliding bodies ensures that the latter always remain at a predetermined distance in the circumferential direction from one another when the drive sleeve rotates, so that very specific, predetermined driving conditions and impact rates for the tool, which do not change during operation, result. The striking mechanism is switched on when the forced holder is held in a rotationally fixed manner and the drive sleeve is rotating. The hammer mechanism can be switched off by simple means by releasing the rotationally fixed fixing of the forced holder. Then the forced holder rotates together with the drive sleeve without, however, the drive piston being driven axially back and forth. The striking mechanism stands still. Depending on the structural conditions, the drive conditions can be interchanged, ie the drive sleeve can be held in a rotationally fixed manner and the forced holder can instead be driven all round. The invention also opens up the possibility to drive both the drive sleeve and the forced holder circumferentially, but preferably in opposite directions to each other, whereby the advantage is achieved that the ratio of the number of impacts to the speed of the tool can be chosen such that z. B. when used as Drill hammer results in an optimal drilling pattern with regard to the drilling progress and the smooth running of the machine.

An advantageous embodiment provides that the number of alternating curve maxima and curve minima of the guide surface is selected such that in particular three axial blows can be applied to the racket and thus to the tool per full revolution of the rotating drive sleeve or forced holder. Three blows per revolution have proven to be the cheapest solution, as this results in three through-grooves with a segment angle of 60 ° when hammer drilling. This is completely sufficient to achieve good drilling progress and a relatively quiet run.

If one chooses a deviating from the sinusoidal course for the guiding surface, e.g. B. asymmetrical, course, this results in the advantage that you can adjust the back and forth movement of the drive piston, speed and acceleration better to the necessary. B. so that the return stroke with suction movement slower and the forward stroke with compression and subsequent acceleration phase of the racket against the tool faster.

A further advantageous embodiment provides that two or preferably three or more rolling or sliding bodies arranged at equal angular distances from one another in the circumferential direction are provided. Two such bodies are sufficient. They ensure that the forces driving the drive piston axially act centrally on the drive piston, which enables very low loads on the guide of the piston and other guide surfaces and high stability even over a long service life. It can be advantageous if the roll or. Sliding bodies as rollers, balls, sliding blocks or the like. And are preferably hollow inside. This keeps the oscillating masses as small as possible.

The forced holder can be rotatably or rotatably driven in the housing relative to the drive sleeve and / or can optionally be released for rotation from the rotationally fixed position via a coupling. In the case of a non-rotatable arrangement, the percussion drive is carried out via the circumferential drive sleeve. If the forced holder is released for rotation, the striking mechanism is switched off, as already explained at the beginning. If the forced holder is in turn driven in rotation, the drive sleeve can instead be held in a rotationally fixed manner. This represents the reversal of the first-mentioned drive conditions. Instead, however, it is also possible to also drive the drive sleeve at the same time, and advantageously in the opposite direction to the forced holder. This has the advantage that the ratio of the number of impacts to the speed of the tool is not or has to be an integral multiple, but can also be a fractional number. With this design, extremely high impact rates can be achieved with a relatively low number of drives.

A further advantageous embodiment provides that the drive sleeve and / or the rotary sleeve and / or the tool holder are integral with one another or at least have a rotationally fixed drive connection and that they are all arranged coaxially with one another. The racket works directly on the tool, so that an intermediate drill spindle z. B. with an anvil is unnecessary. The arrangement described is structurally simple and cheap and reduces weight, dimensions and costs. Instead of the above-described training, the arrangement can also be such that the latter and / or the rotating sleeve and / or the tool holder are integral with one another or at least are in a rotationally fixed drive connection in the case of a rotationally driven forced holder.

It can also be advantageous if the drive sleeve on the end facing away from the racket has a coaxial inner or outer circumferential toothing or a coaxial gear, in particular special spur or bevel gear, which is directly rotatably coupled or via a safety coupling to the drive sleeve, and when the drive motor carries a drive pinion on the motor shaft which is in engagement with the peripheral toothing or the gearwheel. So there are only two gears of the transmission necessary with a corresponding reduction in the number of bearings and bearings.

In a further advantageous embodiment, the guide surface is arranged on an axial end surface of the drive sleeve and is designed as an axial cam surface. The latter is arranged on a radially projecting annular shoulder on a peripheral part of the drive sleeve facing away from the racket. Both the racket and the drive piston are arranged tightly and slidingly and one behind the other within the drive sleeve and the rotating sleeve, which is in particular one-piece, and is non-rotatable. With this design, the drive piston and racket are both located inside the drive sleeve and axially one behind the other. It is advantageous if the forced bracket is formed from at least one radial bearing pin, which at the end carries a sliding body or a roller rotatable about the pin axis, which runs on the axial cam surface, and when the bearing pin is held in a rotationally fixed manner relative to the housing and preferably by means of against an axial compression spring with its sliding body or the roller the axial cam surface can be pressed. It may also be advantageous if the bearing pin is designed as a piston pin diametrically penetrating the drive piston, which is held in it, with sliding bodies or rollers arranged at each end. The bearing pin and the drive piston can be supported on the housing in a non-rotatable manner by means of the axial compression spring and preferably can be released for rotation. Furthermore, the arrangement in this design can be such that the drive sleeve with one-piece rotating sleeve and one-piece tool holder in the axial region of the tool holder on the one hand and the annular shoulder with axial cam surface on the other hand are each supported in the housing by means of a bearing, in particular a roller and / or roller bearing is. So only two bearings are necessary, which store the one-piece part, consisting of drive sleeve, rotating sleeve and tool holder, in the housing. The interior of the drive sleeve with rotating sleeve is optimally utilized by the racket and drive piston inside. Through the piston pin, the two sliding bodies or rollers are kept in the circumferential direction at a distance of 180 ^0th Since the piston pin is fixedly connected to the drive piston in the circumferential direction, both form a unit. By means of suitable means, pins, projections or the like. Or also by means of the axial pressure spring, the drive piston is held in the housing in a rotationally fixed manner with piston pins and sliding bodies or rollers held thereon. At the same time, the sliding bodies or rollers are pressed against the axial cam surface via the axial compression spring. So you follow this cam surface. Rotation of the drive sleeve with the cam surface leads to the cam surface moving past the spatially fixed sliding bodies or rollers and the axial movement of the drive piston thereby being reciprocated. This action does not apply if the non-rotatable mounting of the drive piston with piston pin and sliding bodies or rollers is removed. Then the drive piston rotates together with the drive sleeve without any relative movement between the axial Cam surface on the one hand and sliding bodies or rollers on the other hand. The striking mechanism is then switched off. However, the tool is still driven in rotation. The axial compression spring has the advantage that it can be designed so that it responds at maximum compression of the air spring of the air spring hammer mechanism and thus intercepts the maximum pressure and makes the machine softer and more comfortable to use. It is understood that in the power flow z. B. between the tool holder and the drive sleeve, a safety coupling of a conventional type for the protection of the operating person when the tool is stuck, in particular a drill, can be arranged.

The drive of the drive sleeve can take place via an internal toothing or external toothing at the end facing away from the tool holder, which meshes directly with a drive pinion on the motor shaft of the drive motor. So only two gear teeth are necessary. The internal spacing keeps the center distance as small as possible. Better coverage is also achieved.

Instead, the guide surface can also be arranged on the inner peripheral surface of the drive sleeve. It can be designed as a guide trough with an approximately circular arc in accordance with the trough cross section. At least one, preferably two or three, engaging in the guide groove de ball can be provided as a driver. With this design, the guide surface in the form of the guide groove is thus placed in the inner peripheral surface of the drive sleeve. It therefore has here on the inner peripheral surface of the drive sleeve an approximately band-shaped sine curve in the circumferential direction or an asymmetrical curve deviating therefrom. It can also be advantageous if the drive piston is designed as a hollow piston, in particular as such with an open axial piston sleeve pointing towards the tool holder, within which the racket is guided tightly and slidably. This leads to extremely short dimensions in the axial direction of the drive piston.

A further advantageous embodiment provides that the piston sleeve has a driving surface, in particular an annular groove, on the outer circumferential surface, on which or in which the at least one ball engages as driver. In this configuration, the forced holder can be formed from a guide sleeve, which contains an at least essentially axially extending guide slot for each ball, within which the ball is held approximately in a cage-like manner, but is movable in the direction of extension of the guide slot. It can also be advantageous if the guide slot provided for each ball is inclined at an acute angle or is curved in relation to an imaginary, axial cylinder surface line. This also results in an asymmetrical curve deviating from the sinusoidal shape with the advantage that it allows the back and forth movement of the drive piston, speed and acceleration to be better adapted to the necessary conditions, in a similar manner as by a course of the guide surface deviating from the sinusoidal shape.

It is advantageous if the guide sleeve runs coaxially with the hollow piston with the piston sleeve and concentrically surrounds the latter and leads inside. A further advantageous embodiment provides that the drive sleeve surrounds the guide sleeve at a radial distance and at least to the axial length over which the at least one guide slot extends, and that each ball positively guided in a guide slot in radial direction through the guide slot ^' and on the one hand engages in the guide groove and on the other hand in the annular groove.

In this principle, the guide groove placed in the inner circumferential surface of the drive sleeve with balls causes a rotation of the drive sleeve while the guide sleeve is held so that the balls have to follow the course of the guide groove, thus being pushed back and forth in the axial direction. The movement of the balls takes place within the guide slots of the guide sleeve. Since the latter is fixed, the balls are thus supported against a U movement and forced to follow the course of the guide trough. Since the balls permanently engage in the ring groove of the piston sleeve, the balls transmit the axially back and forth movement to the piston sleeve, as a result of which the drive piston oscillates back and forth? will. Also in this design, only two bearings are required for mounting the drive sleeve and the rest of the device, just as the transmission has only two gearwheels, namely one on the drive sleeve and also a drive pinion on the motor shaft. The arrangement is geared as simple as possible

It is understood that this arrangement can be reversed kinematically, so z. B. the guide sleeve is not arranged in a rotationally fixed manner, but instead can be driven in a rotating manner. If the drive sleeve is then held in a rotationally fixed manner, the drive piston is driven back and forth in the same way. In this case the guide sleeve would then be rotationally fixed with the rotary sleeve and tool holder connect, so that the rotary rotary drive on the tool is then generated via the circumferential guide sleeve. This design also opens up the possibility of holding the drive sleeve in place or releasing it for rotation. In the latter case, the drive sleeve would then be together with the circumferential guide sleeve and no forced movement of the balls along the guide trough is generated. The reciprocating drive movement for the drive piston would be switched off, and thus the striking mechanism. However, the tool would still be driven in rotation via the circumferential guide sleeve. At the same time, this design opens up the possibility of driving not only the J-guide sleeve, but also the drive sleeve all around, but preferably in opposite directions to one another. This enables extremely high impact rates, which can be determined via the gear ratio in the transmission.

The rotating sleeve is advantageously coupled to the tool holder in a rotationally fixed manner and is mounted in the coupling area in the housing.

The rotating sleeve can be made in one piece with the drive sleeve and the drive sleeve can be rotatably mounted on the end of the tool holder, preferably on the guide sleeve, and its gear can be in gear engagement with a drive pinion of the motor shaft.

The guide sleeve can be held in the housing in a rotationally fixed manner.

Instead, the arrangement can also be such that the rotating sleeve is connected in a rotationally fixed manner to the guide sleeve and the guide sleeve is rotatably mounted in the housing and carries a drive gearwheel which is in engagement with a drive pinion of the motor shaft. Then the drive takes place through the guide sleeve with the rotating sleeve held in a rotationally fixed manner.

It can also be advantageous if the drive sleeve is held in the housing in a rotationally fixed manner via a switchable, non-positive or positive-locking coupling, but can be released for rotation. This opens up the possibility of that Switch off the hammer mechanism by switching the clutch and enabling the drive sleeve to rotate.

A further advantageous embodiment provides that the drive sleeve, which is arranged in a rotationally fixed manner, but rotatable when the clutch is triggered, is coupled to a gear which, together with the drive gear of the driven guide sleeve, is in engagement with the drive scribe of the motor shaft, but preferably in the opposite direction to the drive gear the driven guide sleeve is driven. So here both the drive sleeve and the guide sleeve are driven, the latter at the same time also guiding the rotary drive onto the tool via the rotatable rotary sleeve and tool holder. This arrangement has the advantage that the ratio of the number of impacts to the number of revolutions of the tool is no longer or must be an integral multiple, but can be a fractional number. Depending on the number of teeth selected on the gear wheel of the drive sleeve, the drive gear of the guide sleeve and the drive pinion, an optimal drilling pattern for the drilling progress and for the smooth running of the machine designed as a hammer drill can be selected and defined. When the clutch is released, the drive sleeve can be uncoupled from the positive rotary drive, so that it is then not driven in a rotating manner via the gear wheel, but can rotate together with the driven guide sleeve. Then the hammer mechanism is switched off, but the tool is still driven in rotation.

Another advantageous embodiment provides that the piston sleeve on its outer circumferential surface as a Mitnahmefl per ball has a radially recessed ball pocket, within the half of each ball as a positive holder in the axial direction and in the circumferential direction immovable is coupled to the drive piston, and that the drive piston is in turn held in a rotationally fixed manner relative to the housing by means of a switchable coupling or, together with the drive sleeve, can be rotated relative to the housing when the coupling is released. The clutch is so switchable that the hammer mechanism is switched on or switched off in the other case. The rotary drive movement generated for the tool via the rotating drive sleeve is still retained.

In an advantageous further development, the coupling can have a central ball cage with coupling balls held therein, axially parallel or also approximately helical ball troughs for engaging one coupling ball each on the drive piston and an outer switching ring which has receiving pockets on its inner surface for each coupling ball, in which, when the coupling is released, in which the coupling balls emerging radially from the ball grooves can be received, so that the striking mechanism is then switched off in this position of the coupling. The outer switching ring, which can be rotated to switch the clutch, can be actuated via conventional gear means with access from the outside of the machine.

It can also be advantageous if the central ball cage of the clutch is held in the housing in a rotationally fixed manner and supports the drive piston. In this configuration too, only two bearings, which are spaced apart from one another in the axial direction, are necessary for mounting the entire system, and furthermore only the drive pinion and a gearwheel on the drive sleeve.

In all the described embodiments, the motor shaft with the drive pinion can be aligned either axially parallel or at an angle to the longitudinal axis of the drive piston. The arrangement parallel to the axis is made possible by the design described and allows the drive engine in the axial extension of the drive piston and close to the handle area of the machine. This means that the diameter of the machine near the handle can be kept extremely small. In the case of an angular course of the motor shaft, the drive motor can sit in an adapted housing part, which at the same time has a grip character and can be handled from the outside as an additional grip.

It can also be advantageous if the tool holder on the end facing the racket has a catch device for the racket in its ejected idle position. The catching device can have a clamping ring, in particular an O-ring, within the tool holder and on the racket an annular shoulder with shoulders radially sloping in the axial direction on both sides, or vice versa.

The invention is explained in more detail below with reference to exemplary embodiments shown in the drawings. Show it:

1 is a schematic, partial axial longitudinal section of a hammer drill according to a first embodiment,

Fig. 2 is a schematic view of the developed inner

Circumferential surface of the drive sleeve with the guide groove of the hammer drill according to FIG. 1 contained therein,

3 shows a schematic axial longitudinal section of a part of a rotary hammer, for example, below the longitudinal central axis according to a second embodiment and above the longitudinal central axis according to a third embodiment, 4 and 5 each show a schematic axial longitudinal section of a part of a hammer drill according to a fourth or fifth embodiment,

6 shows a schematic side view with a partial longitudinal section of a rotary hammer according to a sixth exemplary embodiment,

7a,

7b and

7c a half section along the line A - A in FIG. 6 or a quarter section along the line B - B or C - C in FIG. 6 once with the striking mechanism switched on or in the other case with the striking mechanism switched off,

8 is a schematic side view with a partial axial longitudinal section of an impact drilling attachment,

9 is a schematic side view with a partial axial longitudinal section of a seventh embodiment of a rotary hammer.

The hammer drill h = b shown in FIG. 1 is a housing 10 in which an electric drive motor 11, which is designed as a universal motor, a gear 12 and a striking mechanism 13 are also arranged. At the rear end, the housing 10 merges into a handle 14, in which a switch provided with a pusher 15 is installed, via which the drive motor 11 can be put into operation. At the lower end of the handle 14, a power supply cable 17 is inserted through an elastic grommet 16. At the front, facing away from the handle 14, a tool holder 18 is arranged in the housing 10, which for receiving an indicated tool 19, z. B. Drill or chisel. The tool holder 18 can be rotatably driven via the gear 12 via a rotating sleeve 20 inside the housing 10. The striking mechanism 13 is also driven by the gear 12. It has an axially reciprocating drive piston 21 which acts on a striker 23 via an air cushion 22. The latter delivers its impact energy directly to the tool 19. Part of the striking mechanism 13 is also a working on the drive piston 21 translation drive 24, which will be explained in more detail below and has an all-round drivable drive member with a curve guide and two scanning the curve guide and engaging the drive piston 21 for its axial displacement engaging driver.

Part of the gear 12 is a conical drive pinion 25, which is non-rotatably seated on the motor shaft 26. The drive pinion 25 meshes with a ring gear 27 of the transmission 12. The motor shaft 26 is oriented at an obtuse angle to the longitudinal axis of the drive piston 21.

The drive member of the translation drive 24 consists of a drive sleeve 28 which is integral with the rotating sleeve. The latter is non-rotatably connected to the tool holder 18, e.g. shrunk tight on the latter. The Werkzeughal ter 18, the rotating sleeve 20 and the drive sleeve 28 thus adjoin one another in the axial direction and are aligned coaxially with one another. The drive sleeve 28 is arranged coaxially with the drive piston 21 and the striker 23 and is both concentric.

The drive piston 21 is designed as a hollow piston and has an axial piston sleeve 29 pointing towards the tool holder 18 and open there, within which the striker 23 is guided tightly and slidably. On its inner circumferential surface, the drive sleeve 28 carries a guide surface designed as a guide groove 30 with an arc-shaped groove cross section. Two balls run inside the guide trough 30, only one ball 31 being visible in FIG. The guide trough 30 is self-contained in the circumferential direction and in this case has an incline that increases and decreases essentially continuously in the circumferential direction, with curve maxima 32 and curve minima 33 directed in the axial direction. As FIG. 2 shows, the guide trough 30 has a circumference approximately sine curve placed on the drive sleeve 28 in the form of a band. However, the course can also be designed to deviate from a sine line, that is to say asymmetrically, so that the back and forth movement of the drive piston 21, the speed and acceleration can be adapted even better to the necessary conditions _? for example, so that the return stroke with suction movement is slower and the forward stroke with compression and subsequent acceleration phase of the striker 23 against the tool 19 is faster. The number of alternating curve maxima 32 and curve minima 33 of the guide trough 30 is selected such that three axial impacts can be applied to the striker 23 and thus to the tool 19 per full revolution of the rotating drive sleeve 28.

As can be seen, the ball 31 engages on the guide groove 30 at a radially adjacent location directly on the drive piston 21. For this purpose, the drive piston 21 has, on its piston sleeve 29, on its outer peripheral surface, a driving surface designed as an annular groove 34, in which the ball 31 engages.

The balls, of which only the ball 31 can be seen, are secured against free, uncontrolled migration along the guide channel 30 by means of a forced holder, which is preferably approximately cage-like in the circumferential direction. secures, but held in the axial direction with degree of freedom for the scanning of the guide trough 30. This forced bracket here consists of a guide sleeve 35 which contains an at least substantially axially running guide slot 36 and 37 for each of the two balls. In the guide slot 36, the visible ball 31 is approximately cage-like th, in the other guide slot 37 Ä.le other, z. B. .. 180 ° circumferentially staggered and invisible ball.

The holder in the guide slots 36 and 37 is such that each ball 31 is movable in the direction of extension of the guide slot 36. The guide slots 36, 37 run exactly axially here. You can instead of an imaginary, axial cylinder surface line obliquely, for. B. acute, be made, which can also be a better adaptation of the back and forth movement of the drive piston 21, the speed and acceleration to the necessary conditions.

As can be seen, the guide sleeve 35 runs coaxially with the drive piston 21 with the piston sleeve 29, the guide sleeve 35 concentrically surrounding the drive piston 21 and simultaneously leading radially and axially in the interior. The drive sleeve 28 surrounds the guide sleeve 35 at a radial distance and at least on the axial length over which the sinusoidal guide groove 30 extends. Each ball 31 ^″ or ball that is not visible in the associated guide slot 36 or 37 engages in the radial direction through the associated guide slot 36, 37 on the one hand in the guide groove 30 and on the other hand in the annular groove 34 of the piston sleeve 29.

In the exemplary embodiment shown in FIG. 1, the guide sleeve 35 is held in the housing 10 in a rotationally fixed manner. It also serves to support the drive sleeve 28, the is mounted on the stationary guide sleeve 35 in the region of the ring gear 27 by means of a ball bearing 38. At the left end in FIG. 1, the bearing in the area of the rotating sleeve 20 relative to the housing 10 also takes place by means of a ball bearing 39.

The tool holder 18 has, on the end facing the racket 23, a safety device in the form of an O-ring 40 for the racket 23 in its ejected, idle position, not shown. A component of this catching device is furthermore on the racket 23 a radially projecting ring shoulder 41 with shoulders 42 and 43 which drop radially in the axial direction on both sides.

The tool 19 has two axial grooves on the inserted shaft, into which a non-visible wedge of the tool holder 18 engages for rotational driving. Furthermore, at least two holding balls 44, 45 are held within the tool holder 18, which engage in axial recesses 46 and 47 of the tool 19, respectively, in such a way that the tool 19 is secured in the axial direction within the tool holder 18 against falling out and at the same time axially in it. and can be moved around.

When the drive motor 11 is switched on, it drives the ring gear 27, which is connected to the drive sleeve 28 in a rotationally fixed manner, via the motor shaft 26 with drive pinion 25. Via this rotary drive of the drive sleeve 28 and thus one-piece rotary sleeve 20, the tool holder 18, which is connected to it in a rotationally fixed manner, and thus the tool 19 is driven in rotation. During this rotation of the drive sleeve 28, the roughly sinusoidal guide groove 30 incorporated therein also rotates. As a result, the balls 31, which are prevented from rotating within the guide slots 36 of the fixed guide sleeve 35, inevitably move within the sinusoidal guide trough 30 and are thus shifted ver in the axial direction alternately to the left and to the right. Since the balls 31 engage radially inward in the annular groove 34 of the piston sleeve 29, this has a reciprocating displacement actuation of the drive piston 21 to the result and - via the air cushion 22 - a percussion drive in the axial displacement in Fig. 1 to the left Strikes 23, which in turn strikes the facing end of the tool 19 so that axial strikes act on it. If the hammer drill when handling with the tool 19 z. B. pressed against a wall, the rotary drive movement of the tool 19 are superimposed on this axial strokes. Each time the racket 23 has its ring shoulder 41 in the axial direction over the O-ring 40, which is slightly deformed in the radial direction, the O-ring 40 endeavors to engage in the rear shoulder 43 and the racket 23 in this to keep the emptied empty position. By acting in the axial direction via the tool 19 acting on the racket 23, the racket 23 is freed from this catch position and moved axially to the right in FIG. 1, so that the racket 23 always acts in the axial direction to the left via the air cushion 22 Experiencing blows and acceleration.

It is not shown that in the first embodiment, for. B. in the flow of force between the ring gear 27 and the drive sleeve 28 or the rotating sleeve 20 or the tool holder 18, a safety coupling can be arranged to protect the operator.

The second exemplary embodiment shown in FIG. 3 below the longitudinal central axis differs from the first exemplary embodiment only in that here the motor shaft 126 with the drive pinion 125 is aligned axially parallel to the drive piston 121 and that further, instead of a ring gear on the drive sleeve 128, a spur gear 127 is seated, which is in engagement with the drive pinion 125.

The third exemplary embodiment shown in FIG. 3 above the central axis differs from the second exemplary embodiment in that the spur gear 227 does not act directly on the drive sleeve 228, but in between a safety clutch 248 which triggers in the axial direction and is known per se, which if. it responds, decouples the drive sleeve 228 from the rotary drive via the spur gear 227, which then continues to spin freely. If the safety clutch 248- responds in this way, not only the striking mechanism, but also the rotary drive for the tool is switched off.

In a modification of the third embodiment, the safety clutch in the power flow between the drive sleeve 228 and z. B. the rotating sleeve 220 or the tool holder 218, then it can be achieved that only the rotary drive for the tool in response. the safety clutch is switched off, whereas the striking mechanism continues to work and applies axial shocks to the tool.

The fourth exemplary embodiment shown in FIG. 4 differs from the previous exemplary embodiments in that the rotary sleeve 320 is now non-rotatably connected to the guide sleeve 335 instead of the drive sleeve 328, which in turn is rotatably mounted in the housing 310 by means of the ball bearing 338. The spur gear 327, which meshes with the drive pinion 325 of the motor shaft 326, is thus connected in a rotationally fixed manner to the guide sleeve 355 in this exemplary embodiment. The drive sleeve 328 is rotatable via a non-positive or positive, for example manually switchable coupling. firmly held in the housing 310, but can be released for rotation by actuating this coupling. The clutch consists, for. B. auε arranged between an outer switching ring 34-9 and the outer peripheral surface of the drive sleeve 328, approximately needle-like rolling elements 350 and also an invisible inner clamping surface on the outer switching ring 34-9. By rotation, the switching ring 34-9 is adjustable so that the rolling elements 350 exert a radial clamping force on the drive sleeve 328, so that the drive sleeve 328 is then held in a rotationally fixed manner. As a result of the rotary drive of the guide sleeve 335, the balls 331 within the guide slots 336, 337 are forced to pass through the guide groove 330 in the fixed drive sleeve 328, so that the drive piston 321 is driven back and forth in the axial direction in the same way as in the first exemplary embodiment. In this fourth exemplary embodiment according to FIG. 4, the drive conditions are only reversed compared to the first exemplary embodiment according to FIG. 1. With the drive sleeve 328 held in place, the tool is driven both by rotation and by impact drive.

If the switching ring 34-9 so. rotated that its inner clamping surface εich radially away from the rolling elements 350, the clamping force acting radially on the drive sleeve 328 is released and the latter free to rotate together with the driven guide sleeve 335 and the balls 331. There is then no reciprocating movement Drive of the drive piston 321 instead. However, the tool is still driven in rotation via the guide sleeve 335, the one-piece rotating sleeve 320 and the tool holder 318. So only the striking mechanism stands still. In another embodiment, not shown, the coupling of the drive sleeve 328 described is designed instead of a force fit, for example in such a way that a locking pin engages radially in a recess in the drive sleeve 328 to stop it. The locking pin can be pulled out radially to release the drive sleeve 328. The scope of the invention also includes other non-positive and also positive couplings which act in the same way.

The exemplary embodiment shown in FIG. 5 roughly combines the elements of the third exemplary embodiment in FIG. 3 with those of the fourth exemplary embodiment in FIG. 4. Also in the fifth exemplary embodiment in FIG. 5, the rotary sleeve 420 is connected to the guide sleeve 435 in a rotationally fixed manner. The latter is driven by the drive pinion 425 on the motor shaft 426 via the spur gear 427, which is rotatable therewith. The drive sleeve 428 is rotatably supported by means of two ball bearings 451, 452 on the rotary sleeve 420 or the guide sleeve 435. In the embodiment shown below the longitudinal center axis, an internally toothed drive wheel 453 is seated on the drive sleeve 428, the teeth of which are also in engagement with the drive pinion 425 of the motor shaft 426. In this case, the drive sleeve 428 is thus also driven by the drive pinion 425, but in the opposite direction to the direction of rotation of the guide sleeve 435. This exemplary embodiment does not provide a shutdown via a clutch. It has the advantage that the ratio between the number of blows and the number of revolutions of the tool is not or must be an integral multiple, but can also be a fractional number. This embodiment makes it possible, depending on the selected number of teeth of the drive pinion 425, the spur gear 427 and the internal toothed drive wheel 453 for z. B. when drilling for the drilling progress and the smoothness of the hammer optima les drilling pattern to choose and set. It is thereby achievable that a one-fold multiply larger number of impacts on the tool are produced when the guide sleeve 435 rotates one revolution. In this exemplary embodiment, the tool is driven rota torically via the guide sleeve 435 and thus a one-piece rotary sleeve 420. If instead the rotary sleeve 420 is connected in a rotationally fixed manner to the drive sleeve 428, the tool is rotated via the drive sleeve 428.

A modification is shown above the longitudinal central axis in FIG. 5, which enables the striking mechanism to be switched off, the tool still being driven in rotation via the guide sleeve 435 and rotary sleeve 420. In this staltung the Ge innenv ^'erzahnte drive wheel 453 is not locked in rotation with the drive sleeve 428th Rather, a coupling part 454 is provided, which engages with at least one inner radial tooth 455 in an associated axial groove 456 of the drive sleeve 428 in a form-fitting manner and is displaceable therein in the axial direction. The drive wheel 453 is rotatable relative to the drive sleeve 428. It has e.g. B. to the left in Fig. 5 facing axial teeth 457, in which, under the action of a spring 458, an associated driver on the coupling part 454 engages axially in Fig. 5 to the right. This engagement position is shown in FIG. 5 above the longitudinal center axis. In this case, the drive sleeve 428 is driven, specifically via the drive wheel 453, the axial toothing 457, the coupling part 454 and the radial tooth 455 engaging in the axial groove 456. In this state, the same results as for the one in FIG. 5 below the Embodiment shown longitudinal central axis. For impact shutdown, the coupling part 454, which is designed, for example, as a sliding sleeve, is shifted to the left via a driver 459 in the axial direction according to FIG. 5, so that the coupling part 454 comes out of engagement with the axial toothing 457 of the drive wheel 453 in the axial direction. The latter is still driven by the drive pinion 425, but the rotary drive for the drive sleeve 428 is then switched off. When the guide sleeve 435 is driven, it rotates with it, so that no axially reciprocating drive movement acts on the drive piston 421. However, the rotary drive for the tool still takes place via the guide sleeve 435 and rotary sleeve 420.

The exemplary embodiment shown in FIG. 8 uses the previously explained principle in the case of an impact drilling attachment 560, which is clamped in the chuck 561, for example of a conventional hand drill with a pin 562. The guide sleeve 535 is connected in a rotationally fixed manner to the pin 562 and is integral with the rotary sleeve 520, which is connected in a rotationally fixed manner to the tool holder 518. The drive sleeve 528 is rotatably mounted on the guide sleeve 535 by means of two ball bearings 551 _» 552, but is held immovably in the axial direction. In this respect, the conditions correspond to the exemplary embodiment shown in FIG. 5 below the longitudinal central axis. For the rotary drive of the tool alone, the drive sleeve 528 is not attacked, so that it can rotate in the direction of rotation together with the guide sleeve 535. Then the striking mechanism is switched off. If the latter is to be switched on, the drive sleeve 528 is attacked by hand and this is prevented from rotating. All of the above-mentioned exemplary embodiments according to FIGS. 1-8 have in common that the drive sleeve has the guide groove on its inner peripheral surface, which is shown schematically in development in FIG. 2. Furthermore, in all exemplary embodiments, the hollow piston is provided with a recessed annular groove on the outer circumferential surface of its piston sleeve, and a guide sleeve with essentially axially extending guide slots is also provided. In all exemplary embodiments, the drivers consist of balls which are hollow on the inside, for example. At least two balls are provided for a central force application on the drive piston, which balls are arranged in the circumferential direction at equal angular distances from one another. It can also be three or more balls. The guide sleeve has a guide slot for each ball. All balls engage on the one hand in the guide trough and on the other hand in the annular groove of the piston sleeve. In the schematic representation of the guide trough in Fig. 2, three axial impacts are generated on the tool per revolution of the tool 19. For this design, the following considerations: If you run the guide trough in such a way that only one stroke is produced per revolution of the tool 19, there is only one through-notch when drilling. When designed so that two impacts per revolution of the tool 19 are generated, there is also only one passage notch during drilling, which is repeated after rotation through 180 °. On the other hand, with three impacts on the tool 19 per revolution, there are three through-notches with a segment angle of 60 °. With four impacts per revolution of the tool 19, there are only two through notches with a segment angle of 90 °. This shows that the design of the guide trough with three curves maxima 32 and three curve minima 33 is the most favorable taking into account that this makes the hammer drill simple and becomes extremely light. There are three blows per revolution of the tool 19. This is completely sufficient for drills, for example in the diameter range between 5 and 12 mm, in order to achieve good drilling progress and essentially smooth running.

In the sixth exemplary embodiment shown in FIGS. 6 and 7a-7c, the guide sleeve of the previous exemplary embodiments is missing. Furthermore, the piston sleeve 629 does not have an annular groove on its outer circumferential surface as driving surface per ball 663, 664, but instead has a radially recessed ball pocket 665 or 666 for each ball. In this exemplary embodiment, a total of three balls are provided, of which only the. two balls 663, 664 can be seen. Accordingly, there are also three associated ball pockets on the piston sleeve 629. Each ball 663, 664 is coupled within the associated ball pocket 665 or 666 so as to be non-displaceable in the axial direction and in the circumferential direction with the drive piston 621. The restraint for the balls explained at the outset is thus formed here by these ball pockets 665, 666. To support against rotation, as a further element of the forced mounting, the drive piston 621 is rotatably held relative to the housing 610 by means of a switchable clutch 667 or, when the clutch 667 is released, together with the drive sleeve 628, can be rotated relative to the housing 610. In the latter case, with clutch 667 released, the rotary drive movement for tool 619 is maintained while the striking mechanism is switched off.

As in the previous exemplary embodiments, the drive sleeve 628 has the guide groove 630 on its inner circumferential surface. The drive sleeve 628 is also in one piece with the rotary sleeve 620, which in turn is connected in a rotationally fixed manner to the tool holder 618 is. The drive sleeve 628 carries a drive wheel 627 in a rotationally fixed manner. As in the previous exemplary embodiments, this can be in direct engagement with the drive pinion 625 of the motor shaft 626 or, as shown here only by way of example, mesh with an intermediate wheel 668 on an intermediate shaft 669, which in FIG axial distance carries a gear 670 which engages with the drive pinion 625. The drive sleeve 628 is mounted in the area of the rotary sleeve 620 via the ball bearing 639 relative to the housing 610. The inner ring of the ball bearing is axially non-displaceably clamped between the rotating sleeve 620 and the tool holder 618. The outer ring of the ball bearing 639 is supported on the one hand directly and on the other hand via an intermediate ring ring 671, for example an O-ring, with respect to the housing 610. The latter dampens the impacts generated in the device and must be absorbed by the operator, so that the device can be handled more safely and quietly and without fatigue. In the area of the clutch 667, the drive sleeve 628 is mounted by means of a simple needle bearing 672, which is supported on part of the clutch 667.

Details of the clutch can be seen in particular from FIGS. 7h and 7c, of which the former shows the engaged position in which the striking mechanism is switched on, and the second shows the disengaged position with the striking mechanism deactivated. The coupling 667 has a central ball cage 673 with coupling balls 674 held therein, further on the drive piston 621 axially extending ball grooves 675 for engaging one coupling ball each and, moreover, an outer, rotatably actuated switching ring 676. The latter carries on its inner surface receiving pockets 677 for each coupling ball in which with the clutch released (Fig. 6 below half the longitudinal center telachse and Fig. 7c) the radially emerging from the ball grooves 675 coupling balls 674- are receivable. The middle ball cage 673 of the clutch 667 is held in the housing 610 in a rotationally fixed manner and supports the drive sleeve 628 via the needle bearing 672 and also the drive piston 621 inside.

If the clutch is in the released position according to FIG. 7c, the drive piston 621 is not held in a rotationally fixed manner, but can rotate in the circumferential direction together with the drive sleeve 628 and the balls 663, 664, so that the striking mechanism is switched off after as before, however, the tool 619 is driven in rotation for drilling. By rotating the switching ring 676 from the rotational position according to FIG. 7c to that according to FIG. 7h, the coupling balls 674 disengage from the receiving pockets 677 of the switching ring 676. The coupling balls 674 are pressed radially inwards and into the ball grooves 675 of the drive piston 621. They thus couple the drive piston 721 to the non-rotatable ball cage 673, so that in this position the drive piston 621 is held in a rotationally fixed manner and, when the drive sleeve 628 rotates, the drive piston 621 is driven oscillatingly back and forth. The striking mechanism is thus switched on.

The seventh embodiment shown in FIG. 9 differs, for example, from the first embodiment according to FIG. 1 in that the drive sleeve 728 is not only in one piece with the rotary sleeve 720, but also in one piece with the tool holder 718 in the seventh embodiment. This entire arrangement is mounted in the area of the tool holder 718 by means of the ball bearing 739 and at an axial distance therefrom by means of a roller bearing 778 in the housing 710. In- Within the drive sleeve 728, both the striker 723 and the drive piston 721 are held and guided in a sealed and sliding manner one behind the other in the axial direction. The drive piston 721 is designed as a hollow piston, but without a piston sleeve.

The guide surface, which is self-contained in the circumferential direction and has an essentially continuously increasing and decreasing gradient, with curve maxima 732 and curve minima 733 oriented in the axial direction is arranged here on an axial end surface 779 on the side of the drive sleeve 728 facing away from the tool 719 and as axial cam surface 780 designed, which is shown in Fig. 9 for better clarity only with dashed lines. This axial cam surface 780 is located on a radially projecting annular shoulder 781 of a circumferential part of the drive sleeve 728 facing away from the racket 723. As drivers, two rollers 782, 783 are provided here, the roller axis of which extends radially and are arranged in the circumferential direction at the same angular distance from one another. The rollers 782, 783 scan the axial cam surface 780 and rest on it. The restraint for the rollers 782, 783 consists of a radial bearing pin in the form of a piston pin 784, which passes diametrically through the drive piston 721 and is held therein. The piston pin 784 carries, on both ends projecting radially beyond the drive piston 721, the rollers 782 and 783 which can be rotated thereon. The piston pin 784 with the rollers 782, 783 is thus non-rotatably connected to the drive piston 721 in the circumferential direction. On the axial side facing away from the striker 723, an axial compression spring 785 presses against the drive piston 721, via which the rollers 782, 783 are pressed against the axial cam surface 780. The compression spring 785 is supported with its other end either non-influencably on the housing 710, as is not shown, or it sits on one in the housing rotatable support pin 786 with ring collar 787, on which the compression spring 785 is in turn held in a rotationally fixed manner, but which in turn can either be rotated in the housing 710 or can be fixed non-rotatably relative thereto. For this purpose, the support pin 786 can have, for example, a fork 788 on the side facing away from the compression spring 785, into which a locking pin 789 which can be actuated by hand engages in a radial locking manner. This engagement position is shown in Fig. 9. Then the compression spring 785 and, via this, the drive piston 721, which is non-rotatably attached to it, are held non-rotatably in the housing 710. A rotary drive of the drive sleeve 728 on the one hand causes the rotary drive of the tool 719 and on the other hand leads to the fact that the axial cam surface 780 rotates relative to the rollers 782, 783 held in the circumferential direction and the held piston 721. The rollers 782, 783 run on the cam surface 780, as a result of which the drive piston 721 is reciprocated in the axial direction.

If the locking pin 789 is pulled out of the fork 788 in the radial direction, then the rotationally fixed support of the compression spring 785 with respect to the housing 710 is omitted. The compression spring 7-5 can rotate and thus also the drive piston 721. When the drive sleeve 728 is rotated, this causes that together with the latter, the drive piston 721 rotates at the same time and is not driven to and fro. The striking mechanism is switched off, while the tool 719 is still driven in rotation.

The gear has here on the part 790 of the drive sleeve 728 which is elongated to the right in the manner of a sleeve and has an internal toothing 791 which is in engagement with the drive pinion 725 on the axially parallel motor shaft 726. The internal toothing 791 has the advantage that a better coverage and at the same time a very small center distance between the drive pinion 725 and the toothing 791 can be achieved in the transmission. Instead of the internal toothing 791, an external toothing or a separate gearwheel connected to the drive sleeve 728 in a rotationally fixed manner can also mesh with the drive pinion 725.

In all of the exemplary embodiments, it is of essential advantage that the hammer drill is simple, cheap, compact, light, and at the same time small and low-vibration due to the design described. The translational drive, which converts the rotary drive movement of the drive motor into a translational movement of the drive piston, is extremely simple and requires very few, essentially low-wear parts. The drive makes it possible, when designing the rotary hammer, to choose from the start how many impacts are generated per revolution of the tool. Another advantage of the transmission is that you can get by with only two gears, namely the drive pinion on the motor shaft and the meshing teeth of the drive sleeve or guide sleeve. This significantly reduces the cost, size and weight of the hammer drill. In addition, additional axes or shafts are eliminated. The number of bearings is reduced to a minimum. This also reduces costs, weight and size. There are also very small oscillating masses and thus low vibrational loads for the operator of the hammer drill. The fact that the racket works directly on the tool also makes the hammer much easier and simpler. The impact energy generated is used even better. It is also advantageous that with at least two drivers in the circumferential direction are arranged at equal angular distances from one another and act on the drive piston, the drive piston is not acted on by eccentric forces, but rather by centric forces. The exemplary embodiments shown in FIGS. 1-8 with hollow pistons and piston sleeve also allow construction to be extremely short in the axial direction . This reduces the size and weight of the hammer drill. The drivers, namely balls or rollers, can also be designed as differently designed rolling elements or sliding elements, for example rollers, sliding blocks or the like. To keep the oscillating masses as small as possible, these drivers can be made hollow.

1-8 all forces occurring during the back and forth movement in the guide raceways are positively received and supported, in the seventh embodiment according to FIG. 9 this is done by the compression spring 785- the latter has the advantage that it is so can be designed so that it responds at maximum compression of the air cushion 722 between the drive piston 721 and the striker 723 and thus intercepts the maximum pressure and thus makes the hammer drill softer and more comfortable to use.

Claims

1. Handheld power tool, in particular drilling or impact hammer, with an in particular electric drive motor, by means of which, via a gear, a rotating sleeve with a tool holder acted upon by it, in which a tool can be guided, can be driven in rotation, and by means of which a striking mechanism can also be driven , which has an axially reciprocating drive piston, a striker which can be acted upon by the drive piston via an air cushion and which emits its impact energy to the tool, and a translating drive which operates on the drive piston and which preferably has a drive member which can be driven all round and has a curve and at least a scanning the curve and on the drive piston to its axial displacement attacking with taker, since dur chgek Indicates that the drive member consists of a to the drive piston (21; 721) and racket (23; 723) coaxial and with concentric to give drive sleeve (28; 728) that the drive sleeve (28; 728) a closed in the circumferential direction and thereby a substantially continuously increasing and decreasing gradient having guide surface (30; 780) with axially directed curve maxima (32; 732) and curve venminima (33; 733) that the Driver is designed as a rolling or sliding body (31; 782,783) and on the The guide surface (30 or 780) of an adjacent point acts directly on the drive piston (21 or 721) and that the rolling or sliding body (31; 782, 783) by means of a restraint (35 - 37; 665,667) which is preferably cage-like in the direction of rotation ; 784,785) is secured against free, uncontrolled migration along the guide surface (30 or 630 or 780), but is held in the axial direction with a degree of freedom for scanning this guide surface.

Machine according to Claim 1, because the guide surface (30; 780) has a sinusoidal shape which is approximately band-shaped in the circumferential direction on the drive sleeve (28; 728).

Machine according to claim 1, because the guide surface (30; 780) has an asymmetrical course, which deviates from a sinusoidal curve in an approximately band-like manner and is applied to the drive sleeve (28; 728) in the circumferential direction.

Machine according to one of claims 1-3, since you can see that the number of alternating curve maxima (32; 732) and curve minima (33; 733) of the guide surface (30; 780) is selected such that the racket ( 235723) and thus in particular three axial impacts can be applied to the tool (19; 719) per full revolution of the rotating drive sleeve (28; 728) or forced holder (33554-355535). Machine according to one of claims 1 to 4, characterized in that two or preferably three or more rolling or sliding bodies (31; 782, 783) arranged at equal angular distances from one another are provided.

Machine according to one of claims 1 - 5, because of the fact that the rolling or. Sliding bodies as rollers (782, 783), balls (31), sliding blocks or the like and are preferably hollow on the inside.

Machine according to one of claims 1-6, since you rchgeke nn zeic hn et that the forced bracket (35; 135; 235; 335; 435; 535; 665,667; 784,785) in the housing rotatably relative to the drive sleeve (Fig. 1-3, 9) or rotating drive bar (FIGS. 4, 5 and 8) and / or via a coupling (667; 7 - 789) can be released from the non-rotatable position for rotation.

Machine according to one of claims 1-7, since you rchgeke nn zeic hn et that the drive sleeve (28) and / or the rotary sleeve (20) and / or the tool holder (18) are in one piece with each other or at least in a rotationally fixed drive connection and that all are arranged coaxially to each other.

Machine according to claim 7, since you can see that the rotationally driven positive holder (335; 435; 535) and / or the rotating sleeve (320; 420; 520) and / or the tool holder (318; 418; 518) are integral with each other or stand at least in a rotationally fixed drive connection with each other. Machine according to one of claims 1-9, since you can see that the drive sleeve (26; 128; 228; 428; 628; 728) has a coaxial inner or outer peripheral toothing (453; 791) or a coaxial at the end facing away from the racket Gear (27; 127; 227; 627), in particular spur or bevel gear, which is directly non-rotatable (Fig. 1, 3 below, 5 below, 6, 9) or via a safety clutch (Fig. 3 above) with the drive sleeve is coupled, and that the drive motor on the motor shaft (26; 126; 326; 426) carries a drive pinion (25; 125; 325; 425) which is in engagement with the peripheral toothing or the gear.

Machine according to one of claims 1 - 10, so that the guide surface is arranged on an axial end surface (779) of the drive sleeve (728) and is designed as an axial cam surface (780) (Fig. 9).

Machine according to Claim 11, that the axial cam surface (780) is arranged on a radially projecting annular shoulder (781) on a peripheral part of the drive sleeve (728) facing away from the racket (723).

Machine according to claim 11 or 12, since du-r chgeke nn draws that both the racket (723) and the drive piston (721) are tight and sliding and one behind the other within the drive sleeve (728) and the rotatable, in particular one-piece, rotating sleeve ( 720) are arranged. Machine according to one of claims 11-13, since you have known that the restraint is formed from at least one radial bearing pin (784) which at the end carries a sliding body or a roller (782, 783) which can be rotated about the pin axis, which runs on the axial cam surface (780), and that the bearing pin (784) is held in a rotationally fixed manner relative to the housing (710) and preferably by means of an axial pressure spring (785) with its sliding body or the roller (782, 783) against the axi cam surface (780 ) can be pressed.

Machine according to claim 14, since the bearing pin (784) is designed as the drive piston (721) diametrically penetrating piston pin held in it with sliding bodies or rollers (782, 783) arranged at each end.

Machine according to claim 14 or 15, so that the bearing pin (784) and the drive piston (721) are non-rotatably supported by the axial pressure spring (785) and are preferably supported on the housing (710) so that they can be released for rotation.

Machine according to one of claims 11 - 16, since it is known that the drive sleeve (72 with one-piece rotary sleeve (720) and one-piece tool holder (718) in the axial region of the tool holder (718) on the one hand and the annular shoulder (781) with axial cam surface ( 780) on the other hand, in each case by means of a bearing (739 or 778), in particular roller and / or roller bearing, in the housing (710). Machine according to one of claims 1-10, characterized in that the guide surface (30) is arranged on the inner circumferential surface of the drive sleeve (28) (Fig. 1-8).

Machine according to claim 18, because the guide surface is designed as a guide trough (30) with an approximately circular arc trough cross-section and that at least one, preferably two or three, ball (31) engaging in the guide trough (30) is provided as a driver.

Machine according to claim 18 or 19, since you draw rchgeke nn that the drive piston (21) as a hollow piston, in particular one with an open to the tool holder (18) facing one end of the axial piston sleeve (29) within which the striker (23) is tight and is slidably guided, is formed.

Machine according to one of claims 18 - 20, since you can see that the piston sleeve (29; 629) has a driving surface (34 or, 665,666), in particular an annular groove, on the outer circumferential surface, on or into which as a driver the at least one ball (31 or 663,664) engages (Fig. 1 - 5, 8 or Fig. 6).

Machine according to one of claims 18-21, since you can see that the forced holder is formed from a guide sleeve (35) which contains an at least substantially axially extending guide slot (36) for each ball (31) within the the ball (31) is held approximately like a cage, but is movable in the direction of extension of the guide slot (36) (FIGS. 1-5, 8). Machine according to claim 22, since you can see that the guide slot (36) provided for each ball (31) is inclined at an acute angle to an imaginary, axial cylinder surface line or is curved.

Machine according to claim 22 or 23, since you can see that the guide sleeve (35) runs coaxially with the hollow piston (21) with the piston sleeve (29) and concentrically surrounds the latter and guides it inside (Figs. 1-5, 8 ).

Machine according to one of claims 22 to 24, characterized in that the drive sleeve (28) surrounds the guide sleeve (35) with a radial distance and at least over the axial length over which the at least one guide slot (36) extends, and that each ball (31) positively guided in a guide slot (36) engages in the radial direction through the guide slot (36) and on the one hand into the guide groove (30) and on the other hand into the annular groove (34).

Machine according to one of claims 18 - 25, so that the rotary sleeve (20) is non-rotatably coupled to the tool holder (18) and is mounted in the coupling area in the housing (10) (Fig. 1-9).

Machine according to one of claims 22 - 26, characterized in that the rotary sleeve (20; 120; 220; 620; 720) is integral with the drive sleeve (28; 128; 628; 728) and the drive sleeve on the tool holder is turned away End preferably on the guide sleeve (35; 135; 235; 435; 535) is rotatably mounted and with its gear is in gear engagement with a drive pinion of the motor shaft. Machine according to one of claims 22-27, characterized in that the guide sleeve (35; 135; 235) is held in the housing in a manner fixed against relative rotation (FIGS. 1-3).

Machine according to one of claims 22-27, characterized in that the rotating sleeve (320; 420; 520) is connected in a rotationally fixed manner to the guide sleeve (335; 435; 535) and the guide sleeve (335 _* 435) is rotatably mounted in the housing and a drive gear ( 327; 427) which engages with a drive pinion (325; 425) of the motor shaft (326; 426) (FIGS. 4 and 5).

Machine according to claim 29, since you rchgekenn - characterized in that the drive sleeve (328; 428) via a switchable, non-positively or positively acting coupling (350; 454 - 459) rotatably, but is released for rotation in the housing (Fig. 4th and 5).

Machine according to claims 29 and 30, since you rchgeke nn zeic hn et that the drive sleeve (428), which is arranged in a rotationally fixed manner by means of the coupling (454-459) but is rotatable when the coupling is released, is coupled to a gear wheel (453) which is coupled together with the drive gear (427) of the driven guide sleeve (435) is in engagement with the drive pinion (425) of the motor shaft (426), but can preferably be driven in opposite directions to the drive gear (427) of the driven guide sleeve (435).

Machine according to one of claims 18-21, characterized in that the piston sleeve (629) has on its outer circumferential surface as a driving surface for each ball (663, 664) a radially recessed ball pocket (665 or 666) within which each ball serves as a forced holder is coupled immovably in the axial direction and in the circumferential direction to the drive piston (621), and that the drive piston (621) in turn by means of a switchable clutch (667) is held in a rotationally fixed manner relative to the housing (610) or, when the clutch (667) is released, together with the drive sleeve (628) can be rotated relative to the housing (610) (FIG. 6).

Machine according to claim 32, since you are characterized in that the coupling (667) has a central ball cage (673) with coupling balls (674) held therein, axially parallel or also approximately helical ball troughs (675) on the drive piston (621) for engagement of a coupling ball (674) and an outer switching ring (676), which has on its inner surface receiving pockets (677) for each coupling ball (674), in which, when the coupling (Fig. 7c) is released, the coupling balls (674) emerging radially from the ball grooves (675) ) are recordable.

Machine according to claim 33, characterized in that the central ball cage (673) of the coupling (667) is held in the housing (610) in a rotationally fixed manner and supports the drive piston (621).

Machine according to one of claims 1 - 34, so that the motor shaft with the drive pinion is aligned axially parallel or at an angle to the longitudinal axis of the drive piston (Fig. 2-9 or Fig. 1).

Machine according to one of claims 1 - 35, since by chgeke nn draws that the tool holder (18) at the end facing the racket (23) inside a catch device (40) for the racket (23) in its ejected idle position having.

Machine according to claim 36, characterized in that the catching device has a clamping ring (40), in particular a O-ring, within the tool holder (18) and on the racket (23) an annular shoulder (41) with shoulders (42, 43) which drop radially in the axial direction to both sides ) having.