EP2937188B1 - Machine tool with integrated tool cartridge - Google Patents

Description

The invention relates to a machine tool, preferably designed as a screwdriver, according to the preamble of claim 1.

A screwdriver is used with different screw bits, depending on how the head of the screw currently used is designed, i.e. H. depending on whether it is z. B. to Phillips screws, slotted screws, Torx screws or the like. More is.

In almost all known screwdrivers, the different screw bits are kept loosely in a so-called bit box. The currently required screw bit is taken from the bit box and manually inserted into the tool holder. This is cumbersome and in many cases impractical because there is always the risk that when you quickly switch between different screw bits, the screw bit that is currently not required will be stored somewhere where it can no longer be found later or falls down and then gets lost.

It has therefore already been proposed to simplify the repositioning of the screw bit etc. with the aid of a magazine body. The documents DE 197 37 892 A1 , WO 00/29173 A1 and U.S. 5,022,131 A disclose magazines that can be moved so far on their guide rod in front of the shaft driven by the machine tool with the receptacle for the screw bit etc. that the previously purely manual process of "repositioning" a screw bit etc. can be followed up can.

In order to remedy this, the German patent application DE 10 2011 082 787 A screwdriver is proposed which has a rotatable magazine body which, like the drum of a drum turret, receives different screw bits and keeps them in stock.

In this screwdriver, the screw bit currently used for screwing is held in a tool holder that is driven in rotation from the side. The end face of the screw bit facing away from the blade of the screw bit is supported against a tool pressure pin which in turn diverts the forces transmitted to it by the screw bit into the housing of the machine tool on its side facing away from the screw bit.

In order to be able to change bits, the known screwdriver is designed so that the end of the tool pressure pin facing away from the blade can be detached from the housing, whereupon the tool pressure pin is translationally displaceable so that it can be used as a "ramrod", so to speak.

This is because it can be withdrawn so far that it takes the screw bit currently in the tool holder back into the tool holder chamber of the magazine body. By now turning the magazine body, another screw bit is brought into alignment with the tool pressure pin. If the tool pressure pin is now pushed forward again, then it pushes the said, new screw bit in front of it until it is positioned in the tool holder in such a way that its blade protrudes out of it forwards. Now you can start screwing.

The fact that this construction is not the drive shaft itself, but a separate tool pressure pin as "Ram stick" and used to support the forces occurring on the screw bit has already gained a lot, among other things because the drive shaft bearings can be dimensioned much weaker.

Nevertheless, there are disadvantages in this design due to the need to fix the tool pressure pin, which is movable as such, before each screwing and to loosen it again before each tool change.

It is therefore the object of the invention to provide a machine tool which is improved with regard to the pressure pin.

This problem is solved with the features of the first main claim. Accordingly, a machine tool, in particular in the form of a hand-held machine tool, is provided which has a main housing part, a tool holder that rotates about a working axis of rotation during operation, and a drive.

The term machine tool is used in its most general meaning and includes e.g. B. also screw robots. The term hand machine tool stands for a machine tool operated by the user with a free hand, such as. B. a cordless screwdriver or an electric drill.

The said main housing part can be in one piece or consist of two or more interconnected components, mostly in the form of half or partial shells. The main housing part is preferably designed in such a way that, when the machine tool is ready for screwing or drilling, it completely accommodates the drive, possibly the rechargeable battery and in any case the magazine body in its interior. As a rule, the main housing part also forms a pistol-like handle.

The machine tool according to the invention has a magazine body with tool receiving chambers for receiving different tools. The machine tool according to the invention is characterized in that the magazine body can be displaced back and forth with respect to the main housing part in the direction parallel to the working axis of rotation. In this way, the magazine body can be pulled out of the main housing part in the manner of a drawer for the purpose of changing tools. As a result, the magazine body moves relative to the tool pressure pin, the i. d. R. as such stands still relative to the main housing part. This pulls the currently inserted screw bit out of the rotationally drivable tool holder and conveys it back into the corresponding tool holder chamber in the magazine body.

It is provided that the drive drives a drive shaft that extends through the magazine body. The drive shaft itself has a pinion that drives the tool holder. The drive shaft is detachably connected to the output shaft of the drive, the machine tool being designed such that the connection between the drive shaft and the output shaft is released when the magazine body is in the screwed position.

The idea of moving the magazine body for the purpose of changing tools instead of the tool pressure pin leads to significant improvements.

The fact that the connection between the tool pressure pin and the main housing part no longer has to be a connection that can be detached and re-established countless times, but rather a connection that cannot be detached or that cannot be detached during normal operation is provided can be, leads to a substantial structural simplification of the screwdriver according to the invention. At the same time, operational safety is usually also improved. With the known construction, the user may be surprised that the tool pressure pin has inadvertently not been adequately fixed on the housing again after the tool change, whereupon the screw bit suddenly yields during the next screwing process, which requires strong pressing by the tool pressure pin suddenly loosening from its inadequate anchorage. The result is uncontrolled slipping with the screwdriver.

The magazine body is preferably rotatably mounted in a slide, which in turn is mounted on the main housing part so as to be movable in the direction parallel to the axis of rotation with the aid of at least one sliding guide. This slide can be pulled out of the main housing part in a similar way to a drawer. The slide can preferably be pulled out towards the front, i.e. the side on which, in the ready-to-screw state, for example, the blade of the screw bit is located.

It is particularly favorable if the sliding guide is an external guide or also comprises an external guide which consists of at least one and preferably at least two, ideally diametrically opposite, slide tongues that are guided on the outer surface of the main housing part. Such a guide on the outer surface of the main housing part has the great advantage that the guide can be designed very generously, since the inner workings of the machine do not have to be taken into account, which is supported in many places on the inside of the main housing part and therefore the one Sliding guide the space available is very limited.

For this purpose, the main housing part is preferably designed in such a way that it has at least one guide groove on its outer surface for the guiding reception of a slide tongue. The guide groove and the slide tongue are ideally designed in such a way that the corresponding slide tongue extends beyond the area in which the pistol-like handle is connected to the rest of the main housing part when the machine tool is ready for screwing. Thus, the machine tool is also compact when a long and extensively extendable sliding guide is implemented. Ideally, this at least one guide groove is designed in such a way that the slide tongue assigned to it can be pushed in from the face of the guide groove facing the blade of the screw bit.

It is particularly favorable if the at least one guide groove forms an undercut in such a way that the guide train received by it is held by the guide groove in all directions perpendicular to its direction of movement, including, for example, in a radially outward direction. Such a construction makes the sliding guide or the slide, even if it is made of plastic, insensitive to bending and torsional loads, so that the overall result is a very stable slide.

Ideally, at least one, preferably at least two mostly metal bearing balls are held at the bottom of the at least one guide groove, mostly in a bearing socket formed in the main housing part at the corresponding point. The guide tongue assigned to this guide groove rolls on these bearing balls. In this way, the guide tongue runs particularly smoothly. The positioning of the one or more bearing balls is preferably selected in such a way that, when the tool is ready to be screwed or drilled, they are positioned radially inward Direction lie under a section of the guide tongue marked as the main gripping surface. This results in a smooth run even if the main gripping surface is pressed firmly. For the same reason, it is advantageous if the at least one guide tongue has a guide groove for the ball or balls on its inside.

It is particularly favorable if the magazine body is part of a tool magazine unit which, for its part, is preferably guided in a translationally movable manner inside the main housing part. In this way, a double support results, which makes the machine tool very robust, for example against falling when the tool magazine unit is pulled out if the user has dropped the machine tool in the course of the tool change.

This double support can be implemented particularly easily if the tool magazine unit comprises a magazine sleeve and a magazine body rotatably mounted in the magazine sleeve. The magazine sleeve can then easily be guided on its outer circumference opposite the inner surface of the main housing part without impairing the rotational mobility of the magazine body.

It is particularly favorable if the machine tool comprises a coupling for coupling and uncoupling the drive shaft of the drive. Because then it becomes possible to pass the drive torque required on the side of the tool magazine unit facing away from the drive through the tool magazine unit without impairing the displaceability of the tool magazine unit. This is because the part of the shaft required for the drive that is mounted in the tool magazine unit becomes the tool magazine unit when it is pulled out unceremoniously withdrawn or uncoupled from the drive shaft of the drive and pushed back on or reconnected in the course of pushing the tool magazine unit back in.

This enables an extremely compact design. However, the coupling is preferably designed so that it works in a purely form-fitting manner. Ideally, it consists of a coupling sleeve with a non-circular internal cross-section and two shaft sections to be coupled with one another with a corresponding non-circular external cross-section. Ideally, the coupling comprises a coupling sleeve which is mounted such that it can slide in the axial direction. This is designed in such a way that the tool magazine unit can also be pushed into the main housing part to the maximum or into its end position when the drive shaft and the coupling sleeve are positioned so that their profiles are currently not ready to engage due to different rotational positions. Although the drive shaft cannot initially be pushed into the interior of the coupling sleeve, it nevertheless does not hinder the complete insertion of the tool magazine unit, since it cannot penetrate the coupling sleeve, but displaces it. As soon as the drive is set in motion, the drive shaft of the drive rotates after a short time so that the coupling sleeve can now snap onto it. This is automatically coupled when starting up.

• Die Figur 1 zeigt ein erstes Ausführungsbeispiel in Gestalt eines Akkuschraubers in schraubbereiter Position.
• Die Figur 2 zeigt das gleiche Ausführungsbeispiel beim Werkzeugwechsel.
• Die Figur 3 zeigt das Ausführungsbeispiel gemäß Figur 1 in explodierter Darstellung.
• Die Figur 4 zeigt ein zweites Ausführungsbeispiel des erfindungsgemäßen Akkuschraubers in schraubbereiter Position.
• Die Figur 5 zeigt das gleiche Ausführungsbeispiel beim Werkzeugwechsel.
• Die Figur 6 zeigt den das zweite Ausführungsbeispiel bildenden Akkuschrauber in teilweise zerlegter Form, um dadurch die Innenführung der Magazinhülse am Gehäusehauptteil zu visualisieren, durch die sich dieses zweite Ausführungsbeispiel auszeichnet.
• Die Figur 7 zeigt die andere Hälfte des das zweite Ausführungsbeispiel bildenden Akkuschraubers in teilweise zerlegter Form.

Further advantages, effects and possible configurations of the invention emerge from the following description of an exemplary embodiment on the basis of the figures.

• The Figure 1 shows a first embodiment in the form of a cordless screwdriver in a position ready for screwing.
• The Figure 2 shows the same embodiment when changing tools.
• The Figure 3 shows the embodiment according to Figure 1 in an exploded representation.
• The Figure 4 shows a second embodiment of the cordless screwdriver according to the invention in a position ready for screwing.
• The Figure 5 shows the same embodiment when changing tools.
• The Figure 6 shows the cordless screwdriver forming the second exemplary embodiment in partially disassembled form in order to visualize the internal guide of the magazine sleeve on the main housing part, which is characterized by this second exemplary embodiment.
• The Figure 7 shows the other half of the cordless screwdriver forming the second exemplary embodiment in partially disassembled form.

THE FIRST EXAMPLE

In order to understand the basic principle of the invention, it is best to turn to the first Figures 1 and 2 to.

The Figure 1 shows the cordless screwdriver ready to be screwed, which serves as an exemplary embodiment here. However, the invention can also be applied to a drilling machine or to a machine tool equipped with end mills or grinding pins.

As can be seen, the carriage is 25 in Fig. 1 in its completely pushed onto the main housing part Position. The slide tongue 26a extends beyond the area where the pistol grip merges into the rest of the main housing part 5a. The rotationally driven tool holder 28 extends through the front plate of the slide 25 and protrudes outward over it. A screw bit is inserted into it as an example.

The Fig. 2 shows the same cordless screwdriver with the slide 25 completely pulled out of the main housing part 5a for the purpose of changing tools. The latter can be seen through the large window of the magazine case. A corresponding window is also available on the upper side of the magazine case, for the purpose to be discussed in more detail later.

Well based on the Fig. 2 it can also be seen that the guide tongue 26a is accommodated in the guide groove 30a of the main housing part in such a way that it fits into the outer surface of the main housing part essentially without a step.

Finally, you can see in Fig. 2 in the area of the guide groove 30a on which the slide tongue 26a reveals that the guide groove 30a is equipped in the region of its lateral edges with an undercut which acts in a substantially radial direction and into which the edges of the long sides of the slide tongue engage in a form-fitting manner, so that it cannot be pulled out of the outer guide groove 30a even by forces in the radially outward direction.

The Fig. 3 shows the exact structure of an embodiment of the invention, which is designed here as a preferably battery-powered screwdriver or drill / screwdriver.

The case

The main housing part 5a, 5b, which is here in two parts, possibly also in several parts, can be clearly seen. It preferably comprises two half-shells which can be separated and joined perpendicularly to the direction of displacement of the slide, which will be explained in more detail later.

When properly assembled and ready for operation, the main housing part 5a, 5b preferably completely accommodates the drive 3 and the magazine body 7, possibly together with the magazine sleeve 9, the said components being explained in more detail below.

The drive

The motor 1, which is only partially shown, is clearly visible. A gear 2, ideally in the form of a reduction gear, is preferably attached directly to it - in such a way that both form a firmly cohesive unit in the form of the drive 3. This unit is anchored in relation to the main housing part in such a way that it can divert the forces that occur during normal work with the tool into the main housing part. The transmission can be designed as a transmission with a fixed transmission ratio or as a transmission that can be switched into several gears.

The output shaft 4 protrudes from the transmission 2, preferably in the form of a freely cantilevered shaft stub. This has a profile on its outer circumference that matches the coupling to be explained later.

The tool pressure pin

The tool pressure pin 5, which ideally lies parallel to the output shaft 4, without coinciding with the output shaft 4 or being coupled to it in terms of force, preferably protrudes from the gear 2. As a result, the output shaft 4 is kept free from the compressive forces acting in the direction of the tool's longitudinal axis during screwing or drilling.

During operation, the tool pressure pin 5 presses on the end face of the screw bit or drill that is currently in use, facing away from the blade or cutting edge. The tool pressure pin 5 can and must absorb considerable forces, as z. B. when screwing the screw bit often has to be pressed firmly into the profile of the screw, which is designed as a cross recess, for example, if high tightening or loosening torques have to be achieved. Its anchoring on the drive 3 or the gear 2 allows the forces occurring on it to be diverted more evenly into the main housing part 5a, 5b than if the tool pressure pin 5 itself is attached directly to the main housing part, which, however, initially appears conceivable in principle.

The tool pressure pin 5 is preferably made of metal.

In particularly high-quality embodiments, the tool pressure pin is kept rotatable in order to keep that part of the engine power that is lost due to friction as small as possible. In other cases, for example where a machine tool that is as robust as possible is to be created at low cost, the tool pressure pin is held on the drive in a rotationally fixed manner, for example by being pressed into a receptacle on the drive, as in FIG Fig. 3 shown.

The tool pressure pin has its own longitudinal axis W, which as a rule runs parallel to the axis of rotation D of the drive.

In the ready-to-work state (e.g. when screwing or drilling operations are starting), the tool pressure pin 5 extends through the complete magazine unit, which will be explained in more detail below, and protrudes into the inner opening of the tool holder 28 or at least as far as its rear side.

An important distinguishing feature from other similar devices is that the tool pressure pin 5 is in any case connected to the main housing part in a non-displaceable or even completely fixed manner and is in any case not movable in relation to this in the direction along its longitudinal axis W or the drive axis of rotation D.

The tool pressure pin 5 preferably has a magnetic or permanent magnetic tip, so that the screw bits or other rotary tools adhere to the tool pressure pin, even if the slide to be explained in more detail is pulled out to change the tool.

The tool magazine unit

A so-called retaining ring can be seen with the reference number 6, which keeps the magazine body captured in the magazine sleeve, which will be explained in more detail below.

The magazine body is provided with the reference numeral 7, which in this exemplary embodiment is constructed similarly to the drum of a drum turret. The magazine body 7 has a central bearing bore and around it are grouped individual tool receiving chambers for the immediate accommodation of a screw bit, a drill or something else Rotation tool. The magazine body 7 is preferably made as a whole from translucent plastic material, so that it can be seen in any case whether a tool receiving chamber is equipped or not. In addition, the magazine body 7 preferably has a window 8 for each receiving chamber, which allows the immediate view z. B. releases on the blade of the screw bit, which is kept in stock in the respective tool receiving chamber. In this way the user can e.g. B. quickly recognize and decide which of the different bits he wants to use.

The bits are in the Fig. 3 also recognizable, but they are not part of the protected machine tool, since their principle can also be used, for example, where so-called bit drills are used, i.e. drills whose shank is soldered into a hexagonal coupling section or otherwise attached, similar to how you know it from a bit. The same applies mutatis mutandis z. B. for appropriately designed grinding or scraping tools with which, for example, soft wood can be "milled".

The magazine body 7 is rotatably mounted in a magazine sleeve 9. This magazine sleeve 9 is also preferably made of plastic, but it does not have to be transparent. The magazine sleeve 9 in turn has at least one window 10, through which the user in operation, for. B. when changing bits, has an immediate view and manual access to the magazine body 7 and mostly also to its window.

The magazine sleeve 9 is provided with at least one, preferably two, latching tongues 11, which are often diametrically opposite one another. These locking tongues are used to enable the magazine sleeve 9 to lock in its fully inserted and fully withdrawn position relative to the housing or finds a stop so that, once brought into one of the two positions (ready-to-work position or tool change position), it does not slip out of the relevant position unintentionally.

In addition, the magazine sleeve 9 is provided with at least one sliding stop 11a, here in the form of a single stop projection. In the installed state, this at least one sliding stop 11a prevents the magazine case from being pulled out of the main housing part 5a, 5b beyond a certain position.

The magazine sleeve 9 is preferably equipped with guide devices along its outer circumference, with which it implements a sliding guide together with corresponding guide devices of the main housing part. These guide devices are designed in the form of at least one guide strip 12 each on one of two opposite sides, which run along corresponding guide channels 12b. In the embodiment according to. Fig. 3 two guide strips 12 per side are provided, which run along guide channels 12b in the right and left main housing part 5a, 5b on the inside thereof, which can be seen at least on the left main housing part 5b.

The magazine sleeve 9 is equipped with a generally central bearing tube 15 from which in Fig. 3 only a part can be seen, namely the part which can be seen through the window 10 provided in the magazine sleeve 9. The bearing tube 15 has on its side facing the output shaft 4 a freely cantilevered end and is connected with its opposite end to the wall section of the magazine sleeve, which partially closes the end face of the magazine sleeve.

The bearing tube 15 preferably has a dual function. The bearing tube 15 forms with its outer circumferential surface a bearing journal on which the magazine body 7 is rotatably held. At the same time, the internally hollow bearing tube 15 forms with its inner circumferential surface a bearing which rotatably supports the drive shaft of the tool magazine unit, which will be described in more detail below, and which at the same time accommodates the coupling.

In this regard, it should be noted that in Fig. 3 the frontal drive shaft outlet 14 can be seen on the magazine sleeve 9. The drive shaft outlet 14 is the end of the inner opening that passes through the drive shaft bearing tube 15.

A coupling sleeve 16 is inserted into the inner opening of the bearing tube 15. The coupling sleeve 16 is preferably movably held in the bearing tube 15 in the direction along the axis of rotation D, the bearing tube 15 being designed so that the coupling sleeve 16 cannot leave the bearing tube 15 in the direction of the output shaft 4 of the drive. The coupling sleeve is pretensioned in the direction along the axis of rotation D by a coupling spring 18 and is movable in the direction along the axis of rotation 10.

The clutch spring 18 is supported on the one hand on the end ring surface of the coupling sleeve 16 and on the other side on the end ring surface of the bearing sleeve 17. The bearing sleeve 17 is preferably firmly connected to the inner circumference of the bearing tube 15, namely ideally by pressing or injecting into the bearing tube 15. The bearing sleeve 17, which is preferably made of metal and has been pressed in in the present case, can be used to provide a better hold on its outer circumference have wedge-like teeth that cut into the bearing tube.

The bearing sleeve 17 rotatably accommodates the drive shaft of the tool magazine unit, which is identified here by the reference numeral 19.

The drive shaft 19 in turn consists preferably in one piece of a coupling pin 20, which has a non-circular circumferential profile, a preferably round shaft section 21 serving for the bearing and a pinion 22 which is preferably integrally connected to it. In addition, the drive shaft 19 is connected to a bearing journal 23 with which them in working order, d. H. is mounted in a journal mount 24, which is an integral part of the carriage 25, in the state ready for screwing or drilling. The latter is because the bearing journal receptacle 24 is either pressed into a corresponding bore in the slide or is encapsulated with the material of the slide or is glued.

In addition, there is a tool holder 28 which is also hollow on the inside. The clear, not completely round inner cross-section of the tool holder corresponds to the outer cross-section of a bit plus the clearance that is required so that a bit can be changed without problems. The tool holder is preferably connected to a one-piece molded gear that meshes with the pinion 22 of the drive shaft 19.

The tool holder 28 is rotatably mounted on two sides. On the one hand, it runs in a preferably metal bearing sleeve 27, which in turn is inserted in the pressure pin outlet 13 of the magazine sleeve 9, which allows the tool pressure pin 5 to pass through. Here, too, the fastening can take place by pressing in, by gluing in or by overmolding. On the other hand, the tool holder 28 runs in a second, likewise preferably metal, bearing sleeve 29. This second bearing sleeve 29 is itself an integral part of the slide 25. It is preferably pressed into the slide 25 or encapsulated with the material of the slide 25.

After all, it should be noted that the tool magazine unit preferably comprises the magazine body 7, the magazine sleeve 9, the coupling sleeve 16, the bearing sleeve 17, the coupling spring 18, the drive shaft 19 and the tool holder as main components.

The tool magazine unit is firmly connected to the carriage 25, which will be described in more detail below, e.g. B. with the help of screws. In order to carry out a tool change, the tool magazine unit together with the slide is displaced translationally relative to the tool pressure pin 5 in the direction parallel along the axis of rotation D, or preferably pulled forward out of the main housing part 5a, 5b. This results in a sequence of movements during loading that is reminiscent of the reloading movement of a pump gun.

The sled

The slide 25 is in turn displaceably guided on the outside of the main housing part, which here consists of the right main housing part 5a and the left main housing part 5b.

For this purpose, the slide preferably has two slide tongues that are ideally diametrically opposite one another, namely a right slide tongue 26a and a left slide tongue 26b. The slide tongues 26a and 26b are preferably designed so long that they still reach over or with the main housing part with at least 40%, better at least 50% of their total length (measured in the direction parallel to the axis of rotation D) even when the magazine body is maximally pulled out of the main housing part to interact. The slide tongues 26a, 26b are relatively wide measured in the circumferential direction, namely preferably at least 15 mm. In the radial direction, the slide tongues are relatively flat and are preferably predominantly not more than 5 mm thick in this direction.

The slide tongues 26a, 26b preferably form a drawer-like guide with the outer surface of the main housing part.

For this purpose, they in turn run in outer guide grooves 30a, 30b of the main housing part 5a, 5b. These guide grooves are attached to the outer circumference of the housing main part or parts. In relation to the rest of the surrounding surface of the main housing part, they form a recess which, viewed in the radial direction, preferably accommodates at least the predominant part of the respective slide tongue. When the slide 25 is moved into the screwing position, the slide tongues are essentially flush with the course of the surface of the main housing part.

The guide grooves 30a and 30b are preferably dovetail-shaped or equipped with a comparable undercut. The slide tongues 26a, 26b are in any case designed in such a way that they are not only guided in the respective guide groove in the direction parallel to the axis of rotation D, but are also held in the radial direction, which is the case in FIG Fig. 3 is indicated by the arrows P.

For this purpose, it can make sense for the slide tongues to have edge strips RL which positively engage in the corresponding undercut left and right edge of the relevant outer guide groove 30a, 30b.

Preferably in the groove base of the outer guide grooves 30a, 30b there are in each case at least one, preferably several ball receptacles 31, which usually have the shape of a ball socket, which holds the ball, ideally without hindering its rotational mobility. In the present case, two ball seats 31 are provided along an alignment in each of the outer guide grooves. The corresponding balls that are used in these ball seats 31 are in the Fig. 3 marked with the reference numeral 32.

When the slide 25 assumes its ready-to-work position, these two balls lie, preferably seen in the radial direction, below the gripping surface that is offered to the user for pushing the slide back and forth. This grip surface can be visually highlighted so that the user intuitively grips it correctly. In Fig. 3 this gripping surface is designed in the form of a number of slats which together form a double arrow which visualizes the intended displaceability of the slide 25.

The respective slide tongue 26a or 26b rolls on the ball or balls. Because of this, the slide tongues still run easily in the outer guide grooves when the user grabs tightly and applies a relatively large force in the radially inward direction to the slide tongues 26a, 26b.

It is also noteworthy that a ball guide groove 33 is preferably provided on the inside of the slide tongues, in which the balls in turn roll on the inside of the slide tongues 26a, 26b.

It is also noteworthy that the carriage 25 with its large front face plate is on the entire surface Supports the end face of the right and left main housing parts, so that the slide 25 is supported in a stable manner in the ready-to-screw position. The carriage 25 does not have to transfer large pressure loads anyway, since these are transferred via the tool pressure pin 5, which is firmly supported on the gear 2.

It can be clearly seen that the slide tongues 26a, 26b generally serve, on the one hand, to improve the guidance of the slide 25 and the tool magazine unit or even to take over at least the majority of the guidance of the tool magazine unit, at least in the position enabling the tool change.

In some cases it can be said that the magazine body 7 is preferably guided so that it can slide twice, namely on the one hand via the magazine sleeve 9 on the inside of the main housing part and on the other hand via the slide tongues 26a, 26b on the outside of the main housing part.

The kinematics of the drive and the tool change

If you imagine the whole thing in a screw-ready, unexploded state, then it is the case that the tool pressure pin 5 reaches through a tool receiving chamber of the magazine body 7, emerges from the magazine sleeve 9 via the pressure bearing outlet 13 and into the interior of the tool holder 28 or on this reaches.

Seen in the direction of the axis W, a bit, a drill or the like lies in front of the tool pressure pin 5, which is supported against the tool pressure pin 5 with its free end face facing away from the blade. The tool pressure pin 5 may not rotate. However, the tool holder 28 rotates. Since its inner profile corresponds to the outer profile of the bit shaft, the bit concerned rotates together with the tool holder 28 and receives its working torque in this way.

The tool holder 28 is driven as follows:
In the ready-to-screw state, the output shaft 4 protrudes through the optionally available retaining ring 6 and into the coupling sleeve 16. The output shaft 4 only partially fills the interior of the coupling sleeve 16. The other part of the interior of the coupling sleeve 16 is filled by the coupling pin 20 of the drive shaft 19 of the tool magazine unit. In this way, the drive shaft 19 is non-rotatably connected to the output shaft 4 of the drive and is forced to rotate as soon as the drive has been started. The drive shaft 19 then drives the tool holder 28 via its pinion 22 by meshing with its preferably integral gear.

If the slide 25 is pulled along the axis of rotation D for the purpose of changing tools and the magazine sleeve 9 connected to the slide 25 is moved out of the main housing part, then the coupling sleeve 16 comes into operation. This is because it is withdrawn from the output shaft 4 of the drive, since the coupling sleeve 16 moves forward transversely together with the magazine sleeve 9 and the slide 25. In this way, the magazine body 7 is then also moved forward so far that the tool pressure pin 5 is first pulled out of the interior of the tool holder 28 and finally even pulled out of the tool holder chamber of the magazine body 7 - until only the one is still on the screw bit etc. adhering to the free end face of the tool pressure pin 5 remains in the tool chamber.

As a result, the magazine body 7 is rotatable and takes the previously used screw bit with it in the circumferential direction. The user can turn the magazine body 7 with his fingers via the window 10 in the magazine sleeve, which is preferably also attached in a corresponding manner to the underside of the magazine sleeve, which is not visible here, and in this way can select a different screw bit and insert it in Align the tool pressure pin 5.

As soon as the carriage 25 together with the magazine sleeve 9 is pushed back along the axis of rotation D in the direction of the drive 3, the magazine body 7 is first shifted again so that the tool pressure pin penetrates one of its tool chambers and the screw bit located there is in front of it until it finally leaves the tool chamber via the passage 13 and is pushed into the interior of the tool holder 28 which is in alignment therewith. Finally, the tool pressure pin usually also pushes itself at least a little way into the tool holder 28, but this is not mandatory.

How the clutch works is relatively easy to explain. It can of course be the case that the user actuates the electric motor 1 at a moment in which the slide 25 is pulled out and is in the tool change position, whereupon the output shaft 4 changes its position. If, in such a case, the slide is pushed back into its screwing position, the output shaft 4 may not succeed in immediately penetrating the interior of the coupling sleeve 16 again. If the coupling sleeve 16 were rigidly attached, then the slide 25 could not now be brought completely into its screwing position, which is certainly not readily accepted by the user. This is remedied here by removing the coupling sleeve in such a case 16 shifted against the action of the clutch spring 18 in the direction parallel to the axis of rotation D. In this way, the coupling sleeve 16 is pretensioned with respect to the output shaft 4. If you now operate the trigger of the screwdriver and set the motor 1 in motion in this way, the output shaft 4 will rotate for a short moment until its profile is again in alignment with the inner profile of the coupling sleeve 16 and the coupling sleeve 16 is then pushed onto the outer profile of the output shaft 4 under the action of the spring 18, that is to say it is automatically coupled.

The indexing

It is also worth mentioning that the magazine body 7 is preferably provided with an indexing which ensures that the magazine body can always only be in a position in which the tool pressure pin 5 can pass through a tool chamber unhindered. For this purpose, for example, the magazine sleeve 9 can be provided with at least one, preferably at least two guide channels 34, each of which receives an indexing ball 35 and an indexing spring 36 (usually a compression spring). The compression spring biases the indexing ball 35 against a section on the end face of the magazine body 7, which is provided with locking recesses that are used to bring the magazine body with the help of the indexing balls at the end of its respective rotation in a position in which one of its Tool receiving chambers is in a position in which the tool pressure pin 5 can be pushed into the relevant tool chamber without hindrance. The profile used for the purpose of indexing can, but does not have to be, wavy. Latching depressions into which the balls fall can also be arranged at regular intervals in order to hold the magazine body 7 in a preferred position.

Of course, other indexing bodies can also be used instead of the indexing balls 35, for example small bolts.

In summary, one can say that not least the following points are essential:
The tool pressure pin 5 is fixed immovably relative to the main housing part at least in the axial direction.

There is a slide 25 with the aid of which the magazine body 7 can be moved in the direction parallel to the axis of rotation D in the course of a tool change.

The tool holder is part of the slide.

The drive shaft 19 extends through the magazine body 7 and is detachably connected to the output shaft 4. The connection is released when the slide is in the tool change position. The connection is established when the slide is in the screwing position.

THE SECOND EXAMPLE

The Figures 4 to 7 show a second embodiment of the invention.

With the exception of the guidance of the magazine sleeve 9 and the somewhat differently proportioned housing, the second exemplary embodiment does not differ from the first exemplary embodiment. Apart from the changed guidance, the inner workings and in particular the drive, the indexing of the magazine body, its rotatability and the basic displaceability of the magazine body in the "pump gun type" are just the same executed as in the first embodiment, so that what has been described for this and in particular the things that the Fig. 3 shows also apply to the second exemplary embodiment.

Based on Fig. 6 it can be clearly seen that the magazine sleeve 9, which also here rotatably houses the magazine body 7 and cannot rotate, is guided with its outer circumferential surface on the inner surface of the main housing parts 5a, 5b with the aid of a sliding guide.

The components which have been designated as slide tongues 26a, 26b in the first exemplary embodiment are "stunted" in this second exemplary embodiment. They now only form handle tongues 37, mostly without their own guiding function with respect to the respective main housing part. The fingers find a grip on these grip tongues in order to pull on the cap 38 and thereby move the magazine sleeve 9 together with the magazine body 7 out of the housing into the tool change position.

The already mentioned sliding guide, with the help of which the magazine sleeve 9 is guided on the main housing parts 5a, 5b, preferably consists of several sliding strips 39, which are designed on the outer circumferential surface of the magazine sleeve 9 as areas that are raised / protruding in a radially outward direction over their surroundings. Each of the slide strips slides in one on the inner circumferential surface of the main housing parts 5a, 5b between two guide strips 40 which are raised in the radially inward direction and which form a guide channel 41 between them. Each guide channel 41 guides the slide strip 39 received by it on three different sides and thus ensures good support of the magazine sleeve 9 on the main housing parts 5a, 5b. The slide strips 39 are each provided at their end facing the handle with a stopper projection 42, which is provided with a complementary projection on the end facing away from the handle respective guide channel 41 cooperates positively and defines the maximum extension length of the magazine sleeve. Ideally, four slide strips 39 are provided on the magazine sleeve 9, which are received by two guide channels 41 on each main housing part 5a and 5b.

In addition, the Figures 6 and 7th It is easy to see that the magazine sleeve is optionally additionally equipped with at least one, in this case even two, latching arms 43 designed as bending beams clamped on one side. At their end, these ideally each have a latching element 44, here for example two humps spaced apart from one another, between which a latching recess 45 is formed. This latching element always snaps into a complementary latching element which is attached to the opposite main housing part 5a, 5b when the magazine body 9 is completely inserted into the main housing parts 5, 5b. As a result, the magazine body 9 is positively locked with respect to the main housing parts 5a, 5b.

In order to create a locking connection that is as firm as possible and that does not tire as much as possible even in continuous operation, the at least one complementary locking element on the side of the main housing parts 5a, 5b is preferably designed as a metal leaf spring 46 which can snap into the locking element assigned to it on the magazine sleeve, cf. Fig. 7 . For this purpose, the leaf spring 46 is ideally fixed at its two ends to the respective main housing part 5a or 5b and forms a latching cam in its center.

It is also noteworthy that the magazine sleeve 9 overlaps the gear 2 or at least the predominant part of the gear 2 on its outer circumference when the magazine sleeve 9 is completely inserted into the two main housing parts 5a, 5b. Based on Fig. 7 you can see what is meant here. This provides a high level of stability with a very compact structure at the same time.

It is also noteworthy that a preferably common window 47 is formed in at least one or better two main housing parts 5a, 5b, which ideally accommodates a transparent housing section. The window or the said "disk" allow a view of the transparent magazine body through their complementary window, even when the magazine sleeve is fully inserted into the main housing parts 5a, 5b, right into the area of the one or preferably several tool receiving chambers. Last but not least, when tool inserts marked with a colored identification thread are kept ready in the tool chambers, the user can already get an idea of what type of tool insert is kept ready in the adjacent tool receiving chambers before pulling out the magazine body 9.

List of reference symbols

1

engine

2

transmission

3

drive

4th

Output shaft

5

Tool pressure pin

5a

Main housing part

5b

Main housing part

6th

Retaining ring

7th

Magazine body

8th

Window in the magazine body

9

Magazine case

10

More firmly in the magazine slide

11

Locking tongue of the magazine slide

11a

Sliding stop

12th

Magazine slide guide bar

12b

Inner guide channel

13th

Passage for the tool pressure pin

14th

Drive shaft passage

15th

Bearing tube for the drive shaft and the coupling

16

Coupling sleeve

17th

Bearing sleeve

18th

Clutch spring

19th

Drive shaft of the tool magazine unit

20th

Coupling pin of the drive shaft

21

Shaft section

22nd

pinion

23

Journal

24

Journal mount

25th

Sledge

26a

Slide tongue / guide tongue

26b

Slide tongue / guide tongue

27

First bearing sleeve of the tool holder

28

Tool holder

29

Second bearing sleeve of the tool holder

30a

Outer guide groove

30b

Outer guide groove

31

Ball seat

32

Bullet

33

Ball guide groove

34

Guide channel

35

Indexing ball

36

Indexing spring

37

Handle tongue

38

cap

39

Sliding strip

40

Guide bar

41

Guide channel

42

Stopper protrusion

43

Locking arm

44

Locking organ

45

Locking recess

46

Leaf spring

47

window

D.

Axis of rotation of the drive

W.

Axis of the tool pressure pin

P.

Arrow that shows the hold of the slide tongue

RL

Edge strips of the slide tongues

Claims (15)

1. Machine tool, in particular in the form of a hand machine tool, with a main housing part, a tool holder (28) rotating about a working axis of rotation during operation, a drive (3) and a magazine body (7) for receiving different tools, wherein the magazine body (7) opposite the main housing part (5a, 5b) can be moved back and forth in the direction parallel to the working axis of rotation (D), wherein the machine tool is designed such that the drive (3) drives a driving shaft (19) which extends through the magazine body (7), characterized in that the driving shaft (19) has a pinion (22) and drives the tool holder (28) with the latter, wherein the driving shaft is detachably connected to an output shaft (4) of the drive (3), wherein the machine tool is designed in such a way that the connection between the driving shaft (19) and the output shaft (4) is released, when the magazine body (7) is in the changing position, and is established, when the magazine body (7) is in the screwing position.
2. Machine tool according to claim 1, characterized in that the magazine body (7) is rotatably mounted in a slide (25) or in a magazine sleeve (9) which, with the help of at least one sliding guide, is mounted movably on the main housing part (5a, 5b) in the direction parallel to the axis of rotation (D).
3. Machine tool according to claim 2, characterized in that the sliding guide is an outer guide or comprises an outer guide which consists of at least one, preferably at least two, ideally diametrically opposite sliding tongues (26a, 26b) which are guided on the outer surface of the main housing part (5a, 5b) or that the sliding guide is preferably exclusively an inner guide, preferably in such a manner that the magazine sleeve (9) has a sliding guide on its outer circumferential surface which interacts with the inner circumferential surface of the main housing parts in such a way that the magazine sleeve is guided by the main housing parts (5a, 5b).
4. Machine tool according to one of the preceding claims, characterized in that the main housing part (5a, 5b) is open on its end face facing the tool side and is only closed by the slide (25) or a cap (38) attached to the magazine sleeve (9) or formed integrally therewith, which slide or cap complements the missing part of the housing.
5. Machine tool according to one of the preceding claims, characterized in that the magazine body (7) is part of a tool magazine unit, which for its part is preferably guided in a translational manner inside the main housing part (5a, 5b) and or characterized in that the tool magazine unit comprises a magazine sleeve (9) and a magazine body (7) that is rotatably mounted in the magazine sleeve.
6. Machine tool according to claim 5, characterized in that the tool magazine unit comprises a coupling for coupling and uncoupling the output shaft (4) of the drive (3), wherein the coupling preferably is a completely positive-locking coupling.
7. Machine tool according to one of the preceding claims, characterized in that the coupling comprises a sliding coupling sleeve (16) which is designed such that the tool magazine unit can also be completely inserted into the main housing part when the output shaft (4) and the coupling sleeve (16) are in relation to each other in such a way that their profiles are not ready to engage due to different rotational positions, so that the output shaft initially cannot be inserted into the interior of the coupling sleeve and instead displaces the coupling sleeve (16).
8. Machine tool according to claim 7, characterized in that the coupling sleeve (16) can be preloaded by a coupling spring (18) in the direction of the output shaft (4) in such a way that the coupling sleeve (16) which is initially not coupled to the output shaft (4) is pushed in an automatically coupling manner onto the output shaft (4), as soon as the output shaft is driven.
9. Machine tool according to one of the preceding claims, characterized in that the tool magazine unit comprises a driving shaft (19) which preferably extends through it in the middle and one end of which is preferably additionally mounted in a rotatable manner in the slide (25) or, in the absence of a slide, in a cap (38) designed for closing the front opening between of the main housing parts (5a, 5b) and / or its other end is preferably rotatably mounted in the magazine sleeve (9).
10. Machine tool according to one of the preceding claims, characterized in that the tool magazine unit comprises a tool holder (28), one end of which is preferably mounted in a rotatable manner in the slide (25) or its front plate or, in the absence of a slide, in a cap (38) designed for closing the front opening between the main housing parts (5a, 5b) and / or its other end is preferably rotatably mounted in the magazine sleeve (9).
11. Machine tool according to one of the preceding claims, characterized in that the slide (25) consists of a front plate which closes the front opening of the main housing part (5a, 5b), when the slide is completely inserted into the main housing part (5a, 5b), and preferably consists of two guiding tongues (26a, 26b) extending from the front plate, wherein the front plate is penetrated by the tool holder (28), or that the magazine sleeve (9) is connected to a cap (38) designed for closing the front opening between the main housing parts (5a, 5b), which cap is penetrated by the tool holder (28), wherein the cap (38) preferably has at least one, better two grip tongues (37) which overlap one or both main housing parts on the outside, preferably only locally, not on the entire circumference and / or at least by 7 mm in the direction parallel to the longitudinal axis or the axis of rotation of the machine tool.
12. Machine tool according to claim 11, characterized in that the front plate or cap (38) is firmly connected to the tool magazine unit, preferably by screwing or locking.
13. Machine tool according to one of the preceding claims, characterized in that the magazine body (7) is translucent at least in the area of the outer circumference of its tool receiving chambers, in order to make recognizable whether a chamber is occupied and / or the magazine body (7) has material-free windows, each of which allow a direct view into the relevant tool chamber.
14. Machine tool according to one of the preceding claims, characterized in that the magazine sleeve (9) has at least one, preferably at least two material-free windows in its outer circumferential surface, which allow the magazine body (7) to be gripped in order to rotate it and / or at least one of the main housing parts, better both with each other, form a window that is preferably closed with transparent material or unlocked, which window is dimensioned and arranged such that it is aligned with a window in the magazine sleeve, when the latter is in its working position, so that the view on the magazine body (7) is free.
15. Machine tool according to one of the preceding claims, characterized in that an indexing mechanism that preferably acts on an end face of the magazine body and mostly on the outer circumference of the magazine body is installed between the magazine sleeve and the magazine body, with the aid of said mechanism the magazine sleeve can be rotated into preferred positions, in each of which a tool receiving chamber is positioned in front of the tool pressure pin (5) so that the tool pressure pin can be inserted into the tool chamber without hindrance.

Images