EP3141346B1 - Bit holder with depth limit - Google Patents

Description

Field of engineering

The invention relates to a bit holder with a drive shaft, an insertion opening for inserting a polygonal profile section of a screwdriver bit, with an actuating sleeve which is transmitted in the axial direction - relative to the axis of rotation of the drive shaft - from a coupling position in which a rotation of the drive shaft to the screwdriver bit in a freewheeling position in which a rotation of the drive shaft is not transmitted to the screwdriver bit, is displaceable, with at least one coupling element which is rotatably associated with the actuating sleeve, which does not abut in the coupling position and in the freewheeling position on a coupling surface.

With such a bit holder screws can, for example, screw in a plasterboard wall, which have a countersunk head. In the final phase of screwing the screw, the actuating sleeve moves from the coupling position to the release position, with the result that the screwdriver bit is no longer drehmit dragged and stops the Schraubeneindrehbewegung.

State of the art

Such a bit holder describes the DE 20 2008 003131 U1 , A polygonal section of a screwdriver bit is inserted in an insertion opening of a sleeve part which has a round cross section. There are provided coupling elements in the form of balls, through the window of a wall projecting through the insertion opening and engage the polygonal surfaces of the bit, so that it is tied non-rotatably in the insertion opening. A radial outward displacement of the coupling balls is prevented by an inner wall of a cavity of an actuating sleeve. If the actuating sleeve is displaced from the coupling position into a release position, the coupling balls can deflect radially, so that the bit can rotate within the insertion opening.

The DE 36 37 852 C1 describes a screwing tool with a drive shaft and a driven shaft, wherein the output shaft has an insertion opening for inserting the polygonal portion of a screwdriver bit. The drive shaft and the output shaft are coupled together via a dog clutch. By an axial displacement of the two shafts, the dog clutch can be opened. The US2014165794 also describes a deratigen bit holder.

Summary of the invention

The invention has for its object to further develop a generic bit holder benefits advantageous and in particular to provide measures that improve the coupling and decoupling.

The object is achieved by the invention specified in the claims, wherein the dependent claims represent not only advantageous developments of the main claim, but also independent solutions to the problem.

First and essentially it is proposed that the drive shaft is coupled by means of a coupling sleeve with the output sleeve part. The output sleeve part is intended to at least partially surround the drive shaft. It may have a cavity into which projects the drive shaft or through which the drive shaft protrudes. The coupling sleeve can be displaceable in the direction of the axis of rotation of the coupling position in the freewheeling position. In the coupling position is a coupling zone, eg. A clutch contact surface of the coupling sleeve to a counter-coupling zone, for example. A clutch surface of the drive shaft on. These are preferably surfaces whose surface normal in the radial direction to the axis of rotation or surfaces of a spline. The clutch contact surface and the coupling surface may each be a surface of a polygonal arrangement, which engage positively in the coupling position. The coupling sleeve may also be connected to the output sleeve part via an interlocking polygonal positive connection, so that it can be displaced in the axial direction relative to the output sleeve part and is connected in a rotationally fixed manner to the output sleeve part. When the at least one clutch contact surface bears against the at least one clutch face, the drive shaft is connected in a rotationally fixed manner to the driven sleeve part, so that a torque exerted on the drive shaft is transmitted to the driven sleeve part. In the freewheeling position are in the coupling zone and the counter-coupling zone in each case in the radial direction freewheeling sections opposite, wherein in the coupling zone and the counter-coupling zone each have a freewheeling section may be axially adjacent. Preferably, the at least one clutch contact surface is not in positive surface contact on the at least one coupling surface, but in a region in which no torque transmission takes place. For example. it is possible for the at least one coupling contact surface to be opposite a round section of the drive shaft in the radial direction. The at least one coupling surface of the drive shaft may be opposite a round portion of the coupling sleeve, so that the coupling contact surfaces and coupling surfaces formed in particular of polygonal surfaces can rotate freely relative to the respective other component. In the freewheeling point, the coupling surface lies in the region of a freewheeling section of the drive part, which is axially adjacent to the coupling surface. Preferably, the freewheeling portion of the coupling surface is immediately adjacent axially. Also, the said round portion of the coupling sleeve forms a freewheeling section and is preferably adjacent to the coupling bearing surface directly in the axial direction. It can be a ring clearance. The displacement of the coupling sleeve from the coupling position into the freewheeling position preferably takes place in that a stop abuts against a workpiece. Preferably, the stop is formed by an actuating sleeve or is associated with the actuating sleeve. The stop may be formed by a stop ring. The latter can be inserted in a rotationally fixed manner in a mouth opening of the actuating sleeve. The mouth opening is assigned to the end of the actuating sleeve associated with the insertion opening. Preferably, the clutch contact surface is formed by an inner polygonal surface, for example, with a dodecagonal ground plan. The coupling surface may be a surface of an outer polygon, which in particular has a hexagonal floor plan. There may be two inner polygonal sections, which are spaced from each other by a round or freewheeling section. In the freewheeling position, the coupling surface freely engages in this section. The second inner polygonal section serves for the rotationally fixed connection of the coupling sleeve with the driven sleeve part. For this purpose, the inner polygonal section sits axially displaceably on an outer polygonal section of the driven sleeve part. The internal polygonal section has an axial length such that it can simultaneously sit on the outer polygonal section of the output sleeve part and on an outer polygonal section of the drive shaft, so that the second polygonal section can realize a further coupling position in which the drive shaft is non-rotatably connected to the driven sleeve part. This second coupling position is in particular achieved in that the actuating sleeve is completely withdrawn against the restoring force of a spring. In this case, the tip of a stuck in the insertion of the driven sleeve part bits passes through the Mouth opening of the actuating sleeve, so that it can be pulled out of the insertion. At the same time, however, free screwing is also possible in this position. The coupling sleeve is held by the force of a spring in the first coupling position, wherein the spring is preferably supported with its one end on the output sleeve part and with its other end on the actuating sleeve. In this operating position, only a frontmost section of the tip of the bit inserted in the insertion opening projects beyond the mouth of the actuating sleeve. When screwing a screw, for example. In a plasterboard wall abuts in the final stages of the screwing, especially when the countersunk head of the screw enters the surface of the plasterboard, the stop of the actuating sleeve against the surface of the plasterboard wall. Further screwing the screw into the plasterboard then leads to a relative displacement of the actuating sleeve relative to the driven sleeve part or the drive shaft and thus to a relative displacement of the coupling bearing surface relative to the coupling surface in the direction of the freewheeling position. The location of the mouth-side stop is selected so that the clutch contact surface loses its rotational assignment to the coupling surface when the screw head has fully entered the surface of the plasterboard. Then the coupling sleeve reaches its freewheeling position. The drive shaft remains axially fixed to the driven sleeve part coupled. For this purpose, an extension of the drive shaft protrudes into a cavity of the driven sleeve part. About a groove engaging in a groove of the extension is tied up in the cavity. In a second aspect of the invention, it is initially and essentially provided that the coupling surface is not formed by a polygonal surface of the polygonal profile section of the screwdriver bit. Rather, the coupling surface is formed by a portion of the insertion shaft. For this purpose, the insertion shaft has a coupling section, which can be formed by a polygonal section. The coupling surfaces are preferably flat or slightly curved Surfaces. But they can also be strongly curved or formed of several partial surfaces. The coupling section is inserted in a bearing bore, round in cross-section, of a driven sleeve part. The output sleeve part also forms the insertion opening for inserting the polygonal profile section of the screwdriver bit. However, this insertion opening has a polygonal cross-section, so that the screwdriver bit preferably always rotatably inserted in the insertion. It is further provided that the coupling portion is a freewheeling section axially adjacent. The at least one coupling element is axially and rotationally associated with the actuating sleeve. If the actuating sleeve is displaced axially, then the coupling element is moved along. The coupling element protrudes through a longitudinal slot of the wall of the bearing bore in the bearing bore, so that a surface portion of the coupling element preferably bears flat against the coupling surface. In an axial displacement of the coupling element in the longitudinal slot, which is associated with an axial displacement of the actuating sleeve in the axial direction - with respect to the axis of the drive shaft -, the coupling element displaced from the coupling portion in the freewheeling section, where it is in no rotationally inhibiting functional position for drive shaft. In the coupling position are preferably surface portions of a plurality of coupling elements, each of which pass through a longitudinal slot, each on a polygonal surface of a polygonal section of the drive shaft, so that the drive shaft is rotatably coupled to the output sleeve part. The freewheeling section is preferably a round section which has a circular cross section. By shifting the coupling elements in the freewheel section, the surface system is canceled. The surface portions of the coupling elements, which form clutch engagement surfaces in the coupling position, are now at most in tangential contact with the round section, so that the drive shaft can rotate freely relative to the driven sleeve part. The coupling element is preferably a substantially cuboidal body, which consists of a hard Material, such as a hardened steel can exist. The coupling body is constrained by suitable means within the actuating sleeve in the radial direction. For this purpose, in particular a binding sleeve is provided, which is inserted in the actuating sleeve. The actuating sleeve has an axial opening for this purpose. The bondage sleeve is preferably in a press fit in the actuating sleeve. It may have an inner circumferential recess, which has a cylinder jacket inner wall, bear against the radially outwardly directed surface portions of the coupling elements. The width of the longitudinal slot substantially corresponds to the circumferential width of the coupling elements, so that they are substantially free of play in the circumferential direction, but displaceable in the longitudinal slot in the axial direction. They form torque-transmitting bodies in order to transmit torque from the drive shaft to the output sleeve part. The bearing bore and the insertion for the screwdriver bit are in an axial alignment position and are preferably separated by a partition, which forms a bottom of the insertion and a bottom of the bearing bore. For axial captivation of the drive shaft to the output sleeve part, a locking pin can be provided. This locking pin is inserted in a bore of the drive sleeve part and protrudes with a radially inwardly directed end portion in an annular groove of the drive shaft. A radially outer portion of the locking pin can engage in a recess of the actuating sleeve. This recess is preferably formed by a jacket body of the actuating sleeve. There are preferably provided three longitudinal slots in a uniform circumferential angle distribution. The longitudinal slots are surrounded by rings and form windows which extend in the axial direction of the drive shaft. The at least one coupling element preferably engages through the window assigned to it. It has a portion which is arranged radially inside the wall of the bearing bore and a portion which is arranged radially outside the wall of the bearing bore. The actuating sleeve has a mouth end.

In this mouth end, a ring magnet can be arranged. The ring magnet can be arranged behind a stop ring, which can occur when screwing against the workpiece to cause an axial displacement of the actuating sleeve relative to the output sleeve part, so that the coupling elements are brought from their coupling position in the freewheeling position in which the drive shaft is free from the Can turn output sleeve part. In a further development of the invention, a second polygonal section is provided in addition to the first polygonal section described above, wherein the freewheel section lies between two polygonal sections. If the actuating sleeve is displaced in particular against the restoring force of a spring from the coupling position to the freewheeling position and beyond the freewheeling position, the coupling elements lie with their surface portions again on coupling surfaces of a polygonal section, so that the output shaft again assumes a rotationally fixed connection with the driven sleeve part. In this position, a "free screws" is possible in which the working tip of the screwdriver bit protrudes at most far beyond the mouth opening of the actuating sleeve. The sheath body of the actuating sleeve may be made of plastic and have two opposite radially expanded portions of a through-hole. In the passage cavity is a plug-in opening forming portion of the driven sleeve part. In the radially extended Axialendöffnungen stuck on one side of the bond sleeve and on the other side of the magnet or the stop ring. The actuating sleeve is preferably rotatably associated with the driven sleeve part, so that it can be held by the fingers of the user in the second coupling position when the drive shaft or the screwdriver bit is rotated.

Brief description of the drawings

Fig. 1

eine perspektivische Darstellung eines ersten Ausführungsbeispiels eines Bithalters,

Fig. 2

den Längsschnitt gemäß der Linie II-II in Figur 1,

Fig. 3

den Schnitt gemäß der Linie III-III in Figur 2,

Fig. 4

den Schnitt gemäß der Linie IV-IV in Figur 2,

Fig. 5

einen Schnitt gemäß der Linie V-V in Figur 1, jedoch mit in Achsrichtung von der in Figur 2 dargestellten Kupplungsstellung in eine Freilaufstellung verlagerter Betätigungshülse 10,

Fig. 6

den Schnitt gemäß der Linie VI-VI in Figur 5,

Fig. 7

eine Darstellung gemäß Figur 5, jedoch mit weiter axial verlagerter Betätigungshülse 10 in eine zweite Kupplungsstellung,

Fig. 8

den Schnitt gemäß der Linie VIII-VIII in Figur 7,

Fig. 9

eine Explosionsdarstellung,

Fig. 10

eine Darstellung gemäß Figur 2 eines zweiten Ausführungsbeispiels eines Bithalters die Kupplungsstellung betreffend,

Fig. 11

einen Schnitt gemäß der Linie XI - XI in Figur 10,

Fig. 12

den Schnitt gemäß der Linie XII - XII in Figur 10,

Fig. 13

den Schnitt gemäß der Linie XIII - XIII in Figur 10,

Fig. 14

den Schnitt gemäß der Linie XIV - XIV in Figur 10,

Fig. 15

eine Darstellung gemäß Figur 10 jedoch mit in die Freilaufstellung verlagerter Kupplungshülse,

Fig. 16

den Schnitt gemäß der Linie XVI - XVI in Figur 15 und

Fig. 17

eine Darstellung gemäß Figur 10 jedoch in einer zweiten Kupplungsstellung der Kupplungshülse.

Embodiments of the invention are explained below with reference to accompanying drawings. Show it:

Fig. 1

a perspective view of a first embodiment of a bit holder,

Fig. 2

the longitudinal section according to the line II-II in FIG. 1 .

Fig. 3

the section according to the line III-III in FIG. 2 .

Fig. 4

the section according to the line IV-IV in FIG. 2 .

Fig. 5

a section along the line VV in FIG. 1 , but with in the axial direction of the in FIG. 2 illustrated coupling position in a freewheeling position displaced actuating sleeve 10,

Fig. 6

the section according to the line VI-VI in FIG. 5 .

Fig. 7

a representation according to FIG. 5 , but with further axially displaced actuating sleeve 10 in a second coupling position,

Fig. 8

the section according to the line VIII-VIII in FIG. 7 .

Fig. 9

an exploded view,

Fig. 10

a representation according to FIG. 2 a second embodiment of a bit holder concerning the coupling position,

Fig. 11

a section along the line XI - XI in FIG. 10 .

Fig. 12

the section according to the line XII - XII in FIG. 10 .

Fig. 13

the section according to the line XIII - XIII in FIG. 10 .

Fig. 14

the section according to the line XIV - XIV in FIG. 10 .

Fig. 15

a representation according to FIG. 10 but with in the freewheeling displaced coupling sleeve,

Fig. 16

Section according to line XVI - XVI in FIG. 15 and

Fig. 17

a representation according to FIG. 10 However, in a second coupling position of the coupling sleeve.

Description of the embodiments

The bit holder shown in the drawings has a drive shaft 1, which has a free end with a drive profile 9. The free end can be plugged into a drive chuck of an electric screwdriver so that turning the chuck rotates the drive shaft 1 about its longitudinal axis.

The drive shaft 1 is inserted with the drive profile 9 opposite end in a bearing bore 22 of a driven sleeve part 20, which is made of metal. The bearing bore 22 has a circular cross-sectional area, so that the drive shaft 1 can basically rotate within the bearing bore 22. The front end 8 of the drive shaft 1 is supported on a bottom 23 of the bearing bore 22, which has an outer side of a Forming wall, which forms the bottom of an insertion opening 21 for inserting a polygonal profile section 34 of a screwdriver bit 33 with the opposite outer wall 21 '. The cross-section of the insertion opening 21 is polygonal and substantially corresponds to the cross-section of the hexagonal section 34 of the screwdriver bit 33, so that the screwdriver bit 33 is inserted into the insertion opening 21 in a rotationally fixed manner.

Immediately adjacent to the front end 8 of the drive shaft 1 has an annular groove 7. In this annular groove 7 engages an end portion of a locking pin 31 which is inserted in a radial bore 32 of the driven sleeve part 20. A pointing radially outward end of the pin 31 can engage in a recess 17 of a jacket body 30 of an actuating sleeve 10. It can be provided a plurality of circumferentially equally distributed recesses 17.

The drive shaft 1 forms, with its portion which projects into the bearing bore 22, three functional zones 2, 3, 4 which are arranged one behind the other in the axial direction and which cooperate with at least one coupling element 25. In the exemplary embodiment, three coupling elements 25 are provided, each having the shape of a cuboid. They can be made of a hardened material, such as carbide. The coupling elements 25 have a coupling bearing surface 25 ', which in a coupling position ( FIGS. 2 and 3 ) abut respectively on a coupling surface 2 'of a first polygonal section 2 of the drive shaft 1. The measured in the circumferential direction width of the coupling elements 25 corresponds to the slot width of a respective longitudinal slot 24 in which a coupling element 25 can move parallel to the axial direction of the drive shaft 1. The coupling elements 25 pass through a respective window formed by the longitudinal slot 24, wherein their ends forming the coupling bearing surfaces lie within the bearing bore 22 and their opposite ends cooperate radially outside with the actuating sleeve 10.

The side of the coupling element 25 opposite the surface forming the coupling surface 25 'of the coupling element 25 bears against a cylinder inner surface, so that the coupling element 25 can not escape in the radial direction. The contact surface on which bears the radially outwardly facing side of the coupling element 25 is formed by a captive sleeve 26. It has an inner circumferential recess 27, which forms the contact surface.

The binding sleeve 26 is inserted in a recess 11 of the jacket body 30 of the actuating sleeve 10. At a stage 15 of the recess 11, an annular disc 28 is supported, which effectively closes the inner peripheral recess 27. The edge of the binding sleeve 26 is supported for this purpose on the annular disc 28.

In a recess which is arranged at the other axial end of the actuating sleeve 10, inserted a ring magnet 19. This is held by a stuck in the mouth opening 13 stop ring 18. The orifice 13 is spaced from the output sleeve part 20 in such a way that a screwdriver bit 33, which is inserted in the insertion opening 21, in the first coupling position (FIG. FIG. 2 ) protrudes with its working tip from the mouth opening 13. The head of a screw can rest on the magnet 19, so that the screw head is held on the bit holder.

A helical-compression spring 29 is provided, which is located in a cavity section 16 of the actuating sleeve 10, which cavity section 16 is formed by the jacket body 30. One end of the spring supports at a stage 14 of the actuating sleeve 10 from. The other end of the spring 29 is supported on a stage of the output sleeve part 20, so that the spring 29, the actuating sleeve 10 in the direction of in the FIG. 2 applied Kupplungsstelung.

When screwing a screw, the bit holder is in the FIGS. 2 and 3 illustrated coupling position, so that a rotation of the drive shaft 1 is transmitted via the rotationally locked bit 33 to a screw. In the final phase of screwing in the screw, the stop ring 18 comes against the workpiece, so that subsequently the actuating sleeve 10 is displaced in the axial direction relative to the output sleeve part 20. Along with this, the coupling elements 25 leave their first coupling position and travel within the longitudinal slot 24 in the direction of the functional zone 3, which is formed by a freewheeling section 3 of the drive shaft 1. It is a round section with a circular peripheral surface.

In this functional position ( FIGS. 5, 6 ), the round surface of the round portion 3 is tangent to the surface of a polygonal surface limiting 25 'of the coupling elements 25, so that the drive shaft 1 can rotate freely in the bearing bore 22. This has the consequence that the screwdriver bit 33 is no longer drehmit dragged and screwing in the screw is completed. After the bit holder has been separated from the screw, the spring 29, which is tensioned during the displacement from the coupling position into the freewheeling position, causes a return displacement of the actuating sleeve 10 into the coupling position.

There is a third functional zone 4, which has a cross-section as the first functional zone 2. The third functional zone 4 is around a second polygonal section 4 with second polygonal surfaces 4 '. By an axial displacement of the actuating sleeve 10 via the freewheeling position ( FIGS. 5 and 6 ) addition, in the FIGS. 7 and 8 shown second coupling position reached, in which the surface portions 25 'of the coupling elements 25 abut in a planar contact with the second surface portions 4' of the second polygonal section 4. In this second coupling position of the screwdriver bit 33 is again drehgefertelt with the drive shaft 1. In this position, the working tip of the screwdriver bit 33 protrudes maximally far beyond the mouth opening 13. The actuating sleeve 10 can be held in this position by hand, since it can rotate freely relative to the output sleeve part 20. This is a consequence of the design of the recess 27 as a ring recess, so that the coupling elements 25 can move relative to the binding sleeve 26 within the recess 27 in the circumferential direction.

The bondage sleeve 26 has the function of a coupling sleeve. It is to be displaced axially to bring the coupling element 25 from the coupling position to the freewheeling position.

The FIGS. 10 to 17 show a second embodiment whose external appearance in the first embodiment ( FIG. 1 ) corresponds. A drive shaft 1 has a drive profile 9 in the form of a hexagon outer profile, which can be inserted into the lining of an electric screw. At the polygonal section of the drive profile 9, an intermediate section connects, which merges into a polygonal section, which forms a coupling zone with coupling surfaces 2 '. The coupling surfaces 2 'are formed by an outer hexagonal portion of the drive shaft 1. By forming a step, a round section connects to this polygonal section, which has a circumferential groove 7.

The round portion of the drive shaft 1 is inserted in a circular cross section having cavity of a driven sleeve part 20. The circumferential groove 7 is assigned an annular groove 36 of the cavity wall locally. The abutting with its face at the bottom of the cavity extension of the drive shaft 1 is tied in the axial direction by means of a locking ring 35 to the output sleeve part 20. The securing ring 35 simultaneously engages in the annular grooves 7, 35.

At the abovementioned shoulder adjoining the coupling polygon surface 2 'there is an edge section of the mouth of the hollow of the driven sleeve part 20. On the outer wall of the driven sleeve part 20 there is a counter-coupling zone in the form of a polygonal surface section 38. The polygonal surfaces of the polygonal surface section 38 are aligned with the coupling surfaces 2'. of the coupling polygonal section.

The cavity, in which the extension of the drive shaft 1 is inserted, is opposite to an insertion opening 21 for insertion of a bit 33. At one stage of the output sleeve part 20, a helical gear compression spring 29 is supported, which abuts with its other end to a step of a cavity 12 of an actuating sleeve 10.

The actuating sleeve 10 surrounds the protruding from the insertion opening 21 portion of the bit 33 and the output sleeve part 20. The actuating sleeve 10 can from the stop-bound, in the FIG. 10 illustrated coupling position against the restoring force of the spring 29 in the axial direction in the in FIG. 15 illustrated freewheeling position and beyond to the in the FIG. 17 be shown shifted second coupling position.

In the arranged on the side of the insertion opening 21 of the operating sleeve 10 is a stop ring 18. For this purpose, the mouth of the actuating sleeve 10 has a non-circular mouth opening 13, in which a non-circular outer plan view having stop ring 18 rotatably inserted. The stop ring 18 also holds a ring magnet 19th

In a direction of the drive shaft 1 facing diameter enlarged portion of the cavity 12 inserted a coupling sleeve 26. The coupling sleeve 26 is axially fixed and rotatably associated with the actuating sleeve 10. It has at its end facing the drive shaft 1, a coupling element 25. The coupling element 25 is a unitary component of the coupling sleeve 26 and is characterized by a polygonal surface, wherein the internal polygonal surface clutch bearing surfaces 25 'form, in the in the FIG. 10 shown coupling position and thus rest form-fitting manner on the coupling surfaces 2 'of the outer polygonal section of the drive shaft 1.

The coupling element 25 is followed by a round section 39. It is an enlarged diameter section. The rounding portion 39 has an axial extension length which is greater than the axial extension length of the coupling surface 2 'or of the outer polygon portion of the drive shaft 1 forming the coupling surface 2'.

The inner polygonal surfaces 8 of the polygonal section 38 are aligned with the polygonal inner surfaces 25 'of the coupling element 25. The rounding section 39 thus forms an enlarged diameter portion extending on a circular line wall of a polygon socket interior of the Coupling sleeve 26 off. The polygonal surfaces of the polygonal section 37 are in flat and thus positive engagement with the polygonal surfaces of the outer polygonal section 38 of the output sleeve part 20, so that the coupling sleeve 26 rotatably but axially displaceable associated with the output sleeve part 20. In the in the FIG. 10 illustrated coupling position is applied to the drive shaft 1 torque over the surface pairing 2 ', 25' transmitted to the coupling sleeve 26 and thereof via the surface pairing 37, 38 on the output sleeve part 20th

In the final phase of the screwing of a screw into a workpiece, the edge of the stopper ring 18 lying in the screwing direction acts on the surface of the workpiece. In the subsequent phase of Einschraubbetätigung the actuating sleeve 10 and thus the coupling sleeve 26 moves in the axial direction relative to the output sleeve part 20 until the surface investment of the surfaces 25 ', 2' is repealed and the clutch surface 2 'is within the freewheel section 39. The FIG. 15 shows the freewheeling position then reached, in which the drive shaft 1 can rotate freely without rotational drive of the coupling sleeve 26. The coupling zone 25 'of the coupling sleeve 26 surrounds the freewheeling section 3 of the drive shaft 1. The counter-coupling zone 2' of the drive shaft 1 is surrounded by the freewheeling zone 39 of the coupling sleeve 26.

If the actuating sleeve 10 is displaced further in the direction of the drive shaft 1 against the restoring force of the spring 29, then the in the FIG. 17 shown second coupling position reaches, in which the polygon socket portion 37 both torque-transmitting with the outer polygon portion 38 and torque transmitting with the outer polygon portion of the coupling surface 2 'cooperates, so that the coupling sleeve 26 rotatably coupling the drive shaft 1 to the output sleeve part 20.

The above explanations serve to explain the inventions as a whole, which further develop the state of the art independently, at least by the following feature combinations, namely:

A bit holder having a drive shaft 1 rotatably driven about an axis of rotation, having an insertion opening 21 for inserting a screwdriver bit 33 having output sleeve part 20, with a coupling sleeve 26 which surrounds the drive shaft 1 at least partially and in the direction of the axis of rotation of a coupling position, in a A coupling surface 25 'abuts a counter coupling zone, eg a coupling surface 2' of the drive shaft 1, so that a rotation of the drive shaft 1 is transmitted to the output sleeve part 20, is displaceable in a freewheeling position in which the coupling zone and the counter-coupling zone each in freewheeling sections 3, 39 of the drive shaft 1 and output sleeve part 20 are such that a rotation of the drive shaft 1 is not transmitted to the output sleeve part (20);

A bit holder, which is characterized in that the coupling sleeve 26 is axially fixed to an actuating sleeve 10 which forms a stop at its end facing the insertion opening 21;

A bit holder, which is characterized in that the coupling sleeve 26 rotatably but axially displaceable associated with the output sleeve part 20 and / or the coupling sleeve 26 rotatably inserted in the actuating sleeve 10;

A bit holder, which is characterized in that the stop of the actuating sleeve 10 is formed by a stop ring 18 which is non-rotatably inserted in a mouth opening 13 of the actuating sleeve 10;

A bit holder which is characterized in that the coupling abutment surface 25 'is an internal polygonal surface which in particular has a dodecagonal ground plan and / or that the coupling surface 2' is a surface of an external polygon, which in particular has a hexagonal floor plan;

A bit holder characterized in that the freewheel portion 3, 39 is a round portion having a circular cross section;

A bit holder which is characterized in that in the axial direction, a round portion 39 is adjacent to a coupling element 25 'having the clutch contact surface 25', which is in the freewheeling position at the axial height of the coupling surfaces 2;

A bit holder, which is characterized in that the coupling sleeve 26 forms an inner polygonal section 37 which is non-rotatably mounted on an outer polygonal section 38 of the driven sleeve part 20;

A bit holder, characterized in that by a disposed in the mouth opening 13 magnet 19 and / or a spring 29 which acts on the actuating sleeve 10 axially in the direction of the coupling position;

A bit holder, which is characterized in that at least one polygonal surface of the polygon socket section 37 rests in the second coupling position on the coupling surface 2 ';

A bit holder, which is characterized in that the coupling sleeve 26 is a captive sleeve 26 and at least one longitudinal slot 24 through which a axially and rotationally fixed to the actuating sleeve (10) associated coupling element 25 axially displaceable protrudes, wherein the coupling element 25, the clutch contact surface 25 'forms and shifts in the displacement of the coupling position in the freewheeling position within the longitudinal slot 24.

All disclosed features are essential to the invention (individually, but also in combination with one another). The subclaims characterize with their features independent inventive developments of the prior art, in particular to make on the basis of these claims divisional applications. <b><u> List of Reference Numbers </ u></b> 1 Drive shank 24 longitudinal slot 2 Clutch / multi-edge portion 25 coupling member 25 ' Clutch contact surface, surface section 2 ' coupling surface 3 Freewheel, edge section 26 Bonding sleeve, coupling surface 4 Polygonal section 4 ' Polygonal surface 27 Inner circumferential recess 5 bearing section 28 washer 6 bearing section 29 feather 7 ring groove 30 covering body 8th front end 31 safety pin 9 drive profile 32 drilling 10 actuating sleeve 33 Screwdriver 11 recess 34 Polygonal profile section 12 cavity 35 circlip 13 mouth 36 ring groove 14 Stage (actuating sleeve) 37 Polygonal surface (inner polygon surface) 15 Stage (recess) 16 cavity portion 38 Polygonal surface (external polygon surface) 17 recess 18 stop ring 39 edge section 19 magnet 20 Output sleeve member 21 insertion 21 ' outer wall 22 bearing bore 23 ground

Claims (14)

1. Bit holder comprising a drive shaft (1) that can be rotatably driven about an axis of rotation, comprising a driven sleeve part (20) having an insertion opening (21) for inserting a screwdriver bit (33), comprising a coupling sleeve (26) which at least partially surrounds the drive shaft (1) and which can be moved, in the direction of the axis of rotation, from a coupling position, in which a coupling zone associated with the coupling sleeve (26) together with a mating coupling zone of the drive shaft (1) and the coupling sleeve (26) together with the driven sleeve part (20) are interconnected in each case by means of an interlocking polygonal form fit such that rotation of the drive shaft (1) can be transmitted to the driven sleeve part (20), into a free-running position, in which the coupling zone and the mating coupling zone are located in free-running portions (3, 39) of the drive shaft (1) and driven sleeve part (20), respectively, such that rotation of the drive shaft (1) is not transmitted to the driven sleeve part (20).
2. Bit holder according to claim 1, characterised in that the coupling sleeve (26) is associated with an actuating sleeve (10) in an axially fixed manner, which sleeve forms a stop at its end facing the insertion opening (21).
3. Bit holder according to either of the preceding claims, characterised in that the coupling sleeve (26) is associated with the driven sleeve part (20) in a rotationally fixed but axially movable manner.
4. Bit holder according to any of the preceding claims, characterised in that the coupling sleeve (26) is inserted in the actuating sleeve (10) in a rotationally fixed manner.
5. Bit holder according to any of the preceding claims, characterised in that the stop of the actuating sleeve (10) is formed by a stop ring (18) which is inserted in a mouth opening (13) in the actuating sleeve (10) in a rotationally fixed manner.
6. Bit holder according to any of the preceding claims, characterised in that the coupling contact surface (25') is an internal polygonal surface, which in particular has a dodecagonal plan view.
7. Bit holder according to any of the preceding claims, characterised in that the coupling surface (2') is a surface of an external polygon, which in particular has a hexagonal plan view.
8. Bit holder according to any of the preceding claims, characterised in that the free-running portion (3, 39) is a round portion having a circular cross section.
9. Bit holder according to any of the preceding claims, characterised in that a coupling element (25) that comprises the coupling contact surface (25') is adjacent, in the axial direction, to a round portion (39) which, in the free-running position, is located at the axial height of the coupling surfaces (2').
10. Bit holder according to any of the preceding claims, characterised in that the coupling sleeve (26) forms an internal polygonal portion (37) which sits on an external polygonal portion (38) of the driven sleeve part (20) in a rotationally fixed manner.
11. Bit holder according to any of the preceding claims, characterised by a magnet (19) arranged in the mouth opening (13).
12. Bit holder according to any of the preceding claims, characterised by a spring (29) which acts on the actuating sleeve (10) axially in the direction of the coupling position.
13. Bit holder according to any of the preceding claims, characterised in that at least one polygonal surface of the internal polygonal portion (37) rests on the coupling surface (2') in the second coupling position.
14. Bit holder according to any of the preceding claims, characterised in that the coupling sleeve (26) is a captive sleeve and the driven sleeve part (20) has at least one longitudinal slot (24) through which a coupling element (25) associated with the actuating sleeve (10) in an axially and rotationally fixed manner protrudes so as to be able to move axially, the coupling element (25) forming the coupling contact surface (25') and being displaced within the longitudinal slot (24) during the displacement from the coupling position into the free-running position.

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