SE1930193A1

SE1930193A1 - Torque transferring device for use with a power tool

Info

Publication number: SE1930193A1
Application number: SE1930193A
Authority: SE
Inventors: Max Dennis Öhlund; Per Erik Niklas Fransson
Original assignee: Atlas Copco Ind Technique Ab
Priority date: 2019-06-14
Filing date: 2019-06-14
Publication date: 2020-12-15
Also published as: JP3237673U; WO2020249580A1; DE212020000653U1; CN217317774U; KR20220000449U

Abstract

The present specification relates to a torque transferring device (1) for power tools, comprising a first portion(10) comprising a first portion (11) of a tubular body (110) and a first inner element (12) comprising an engaging structure (13) adapted to engage a corresponding mating structure to transfer torque thereto, and a second portion (20) comprising a second portion (21) of the tubular body (110) and a second engaging structure (22) for connection to the output shaft of a power tool, wherein an inner insulating element (30) is provided inside said tubular body rotatably coupled to said first and said second engaging structure such that a torque may be transferred there between and wherein said inner insulating element is made of an electrically insulating material, such that for operator protecting purposes an electrical insulation is formed between said first engaging structure and said second engaging structure.

Description

TORQUE TRANSFERRING DEVICE FOR USE WITH A POWER TOOL Technical field The present invention generally relates to a torque transferringdevice for connection to the output shaft of a power tool such as asocket or a quick change adapter, more particularly to such a device comprising means for increasing work place safety.

Technical Background Torque transferring devices for connection to the output shaft of apower tool, such as a socket for tightening of nuts or screws or anadapter, such as a quick-change adapter, are well known. Forexample, a well-known standard type of socket has a square crosssectional recess at its rear end intended for receiving the squareshaped end portion of a power tool output shaft and an internalcross sectional shape adapted to fit the type of screw joint to betightened, for instance a hexagonal shape, at its front end.Similarly, an adapter such as a quick change adapter may comprisethe same type of structure for receiving the square shaped endportion of a power tool output shaft but, at its front end, a structure for engaging the rear end of a socket or similar.

In order to sustain the high torques to be delivered, commonly someor all parts of such a device have to be made of high strength,durable materials, and commonly metals such as steel are utilized.Apart from being strong and durable, such materials however tend tobe good conductors and thus problems with such devices related tooperator safety may arise when screw tightening is performed in thevicinity of power sources such as batteries or other energizedcomponents. Due to the conductive properties of the device, there isa high risk of electrical shock should a metallic socket come intocontact with energized parts. Such a shock could harm not only theoperator should the operator touch the socket or parts of the tool in electrical contact with the socket but could also cause short circuits damaging components in vicinity of the joint to be tightened.

In order to alleviate some of these problems, attempts have beenmade to provide an insulting outer layer, for example covers orsleeves provided on the outside of the socket or adapter to therebyprovide insulation for operator protection purposes should the operator touch the outer surface.

However, there are still problems remaining for example in thathazardous conductive paths may still be formed bypassing such asleeve which may allow a current to potentially injure an operatoror damage components. Further, such sleeves tend to add bulk to thedesign as the radius is increased making screws in tight positionhard or impossible to reach. Hence there exists a need forimprovement in the field of insulation and electric shock protectionfor torque transferring devices for power tools such as sockets and quick change adapters.

Sumary of the invention Accordingly, it would be desirable to provide a torque transferringdevice for a power tool adapted to provide an improved protectionagainst electric shock and short circuits. In particular, it wouldbe desirable to provide such a device having a compact design. Tobetter address one or more of these concerns a torque transferringdevice as defined in the independent claim is provided. Preferred embodiments are defined in the dependent claims.

According to a first aspect of the present invention a torquetransferring device for power tools is provided, the devicecomprising a first portion comprising a first portion of a tubularbody and a first inner element comprising a first engaging structurearranged at a front end of the first portion and adapted to engage acorresponding mating structure to transfer torque thereto, and asecond portion comprising a second portion of the tubular body and asecond engaging structure for connection to the output shaft of apower tool arranged at a rear end portion of the second body part, wherein an inner insulating element is provided inside the tubular body, wherein the inner insulating element is rotatably coupled tothe first engaging structure arranged at the front end of the firstportion and to the second engaging structure arranged at the rearend of the second body element such that a torque may be transferredthere between, and wherein the inner insulating element is made ofan electrically insulating material, such that for operatorprotecting purposes an electrical insulation is formed between the first engaging structure and the second engaging structure.

According to the first aspect, the torque transferring deviceprovides an inventive solution to the concerns described above bymeans of a design providing an integrated protection againstelectrical shock. This by means of the inner insulating elementarranged to provide an electrical insulation between the firstengaging structure adapted to engage a mating structure such as ascrew, i.e. which hence may be positioned at a potentially energizedposition, and the second engaging structure adapted to engage thetool and hence be in contact with the operator holding the tool.Further, since the insulating component is an insulating componentproviding axial insulation and arranged at least partly on theinsider of the tubular body element, the protection againstelectrical shock is not only more efficient but provided in aparticularly compact manner and hence no undue restrictions are puton the device with regards to tightening of screws arranged atharder to reach positions. Hence, the torque transferring deviceaccording to independent claim l cleverly solves the problem ofachieving a more efficient insulation, i.e. protection againstelectrical shock in a compact manner not increasing the size of thedevice. By provided inside should be understood provided in, orwithin the tubular element, i.e. arranged in a space delimited by aninner side of the tubular element. Further, by tubular should beunderstood a tube-shaped i.e. cylindrical shape having a varying or constant diameter.

The device, which in some embodiments may be for example a socket, aquick change adapter or an extension adapted to be arranged betweensuch a socket and a tool or a bit holder, is hence adapted to both provide a secure engagement between a socket and a nut or screw and a power tool (or in the case of an adapter between such a socket andthe tool) such that torque may be transferred and the screw or nuttightened, but also to protect the operator from an electricalshock. To ensure the secure engagement, the first and secondengaging structure may have any suitable design, such as hex, squareor similar. For example, the device may have a square crosssectional recess at its rear end intended for receiving the squareshaped end portion of a power tool output shaft and an internalcross sectional shape adapted to fit the type of screw joint to betightened, for instance a hexagonal shape, at its front end.Examples include any combination of square female or male input and output and male or female hex input and output.

The insulating material from which the inner insulating componentand/or the insulating outer sleeve is made may be a polymer, forexample a thermoplastic polymer where examples include POM, or insome cases a thermosetting polymer such as epoxy, possiblyreinforced (e.g. glass reinforced). In order to ensure a properinsulation, the distance between conductive elements of the deviceis to be kept sufficiently large such that no short circuits may arise.

The power tool with which the inventive device may be used may be atightening tool such as a screwdriver, such as a pneumatic anelectrically powered screwdriver. The device may be particularlyadvantageous for use with a hand held tool, possibly a battery powered tool, or a handheld manual tool such as a torque wrench.

According to one embodiment, the device is adapted to be arranged atleast partly within the head of the power tool, i.e. the secondengaging structure is a structure adapted to engage the output shaftof the tool in an inner space of the power tool head. The device mayin such an embodiment be described as a so called flush socket or flush mounted socket.

According to one embodiment, the inner insulating element isprovided inside said second portion of said tubular body. Accordingto one embodiment, the inner insulating element comprises asubstantially cylindrical portion having a diameter corresponding to an inner diameter of an adjacent portion the tubular body, for example the second portion of the tubular body. Hereby, an efficientinsulation may be achieved in that as much space as possible inside the tubular body is utilized for the insulating element.

According to one embodiment, the second engaging structure forconnection to the output shaft of a power tool is arranged in theinner insulating element. Hereby, as the output shaft will engagethe non-conductive, inner insulating element a proper operator protection is reliably ensured.

According to one embodiment, the second body element comprises afurther inner element arranged at the rear end, wherein the furtherinner element is rotatably coupled to the inner insulating elementsuch that a torque may be transferred there between and wherein thesecond engaging structure for connection to the output shaft of apower tool is arranged in the further inner element. For example,the further inner element may comprise a socket arranged to improvethe engagement between the tool output and the device. According toone embodiment, the further portion is made of metal, for examplesteel. Hereby, the engagement between the tool output and the device may be made more durable.

According to one embodiment, the first engaging structure arrangedat the front end of the first portion is made of metal. Similarly asdescribed above, a stronger and more durable engagement may therebybe provided by the first engaging structure. In some embodiments,the first engaging structure arranged at the front end of the firstportion further comprises a magnet arranged to facilitate thehandling of magnetic fastening elements such as magnetic screws or nuts.

According to one embodiment, the insulating inner element isrotatably coupled to the first inner element by means of a couplingbetween a first male hex shaped structure comprised by the innerinsulting element and a corresponding female hex-shape structurecomprised by the first inner element. This structure extends in anaxial direction, and further extends into a correspondingly hexshaped recess or socket in the first inner element, Hereby a firmengagement is achieved. The skilled person realizes that any shape other than hex may off course be utilized as well.

According to one embodiment, the inner insulating element isrotatably coupled to the further inner element by means of acoupling between a second male hex shaped structure comprised by theinner insulting element and a corresponding female hex-shapestructure comprised by the further inner element. I.e., the innerinsulating element in such an embodiment comprises two hex shapedstructures, extending in an axial direction at a respective firstand second end of the insulating element, and for example a cylindrical portion arranged there between.

According to one embodiment, the first inner element and the innerinsulating component are rotatably coupled by means of a pinarranged between the first portion and the inner component, suchthat a torque may be transferred there between. One example includesa so called spring pin, i.e. a self-retaining fastener that securesthe position of the two components in question relative to eachother also known as a tension pin or roll pin. In one embodiment,where the device comprises at least one male hex shaped structure, afirst through hole may be provided through this hex shaped structureand an additional through hole may be provided in the first and/orfurther inner element, such that the pin may extend through these holes in order to provide the engagement.

In other embodiments, the first inner element and the innerinsulating component are coupled by means of an adhesive, alone or combined with the spring pin mentioned above.

According to one embodiment, the first portion and the secondportion may be integrally formed. For example, in one embodiment,the first portion of the tubular body and the second portion of thetubular body are integrally formed. Such an embodiment may bedescribed as having a tubular outer body formed by the first andsecond portion of the tubular body, inside which the first innerelement, the inner insulating element and possibly the further innerelement are arranged, such that the first engaging structure and thesecond engaging structure are arranged at a respective first andsecond end of the integrally formed tubular outer body element, i.e. at the openings of the tubular element.

According to one embodiment, the torque transferring device is acomponent chosen from the group socket, bit holder, or quick changeadapter, for example a quick change adapter having a male square orfemale hex output. Further, the device may also be a so called extension.

According to one embodiment, the device is a socket or a bit holder,wherein the engaging portion arranged at a front end thereof adaptedto engage a corresponding mating structure to transfer torquethereto, is a portion adapted to engage a nut or a bit. As mentionedabove, the second engaging portion arranged for connection to anoutput shaft of a power tool may in such an embodiment may equallywell engage a corresponding output of a quick change adapter,extension or similar device arranged between the power tool and thesocket. According to another embodiment, the device is an adapter,for example a quick change adapter or extension, wherein theengaging portion arranged at a front end thereof adapted to engage acorresponding mating structure to transfer torque thereto, is anadapter output adapted to engage a nut socket or bit holder.Examples include an insulated quick change adapter with squarefemale input and square male output or an adapter with square input and female hex output.

In some embodiments, the device further comprises an insulatingouter sleeve provided on the outside of the device for operatorprotecting purposes since additional protection is provided in theform of radial insulation in addition to the axial insulation, thesleeve being made of an electrically insulating material. Forexample, an insulating sleeve may be provided on the outside of atleast one of the first portion and the second portion. In otherembodiment, the insulating sleeve may be formed by the tubular body,i.e. the tubular body may be made of an electrically insulationmaterial such as a polymer for example of the type mentioned aboveor may in other embodiment be a separate insulating sleeve provide on the outside of the tubular body.

According to one embodiment, the insulating sleeve is a freelyrotatable sleeve. Hereby, not only is increased protection provided in that a radial electrical insulation is provided, the operator is also protected from injuries at screw joint tightening operationsdue for instance tangled gloves. According to one embodiment, thefreely rotatable sleeve further comprises a radially protrudingcollar arranged at an end of the sleeve adjacent to the secondengaging structure for additional operator protecting purpose,wherein the collar is made of an electrically insulating material.Hereby, further operator protection is achieved in that the collar prevents the hand of the operator from slipping towards the joint.

According to one embodiment, the freely rotatable sleeve is formedby the tubular body. Further, in one embodiment, the freelyrotatable sleeve is formed by at least the first portion of thetubular body. For example, in some embodiments a shorter freelyrotatable sleeve formed by the first portion of the tubular body isprovided at the first end of the device whereas in other embodimentsa longer sleeve covering the entirety of the length of the device isprovided, for example a sleeve formed by the tubular body asmentioned above. In some embodiment however, only the insulation inaxial direction is provided by the inventive device, for example inthe form of an adapter, whereas the radial insulation may beprovided by a separate socket or bit holder comprising a sleeve of the type described above.

According to one embodiment, the device further comprises anelectronic identification tag such as an RFID-tag. Hereby, thedevice may for example be recognized as an insulated device, such asan insulated socket, by a tool or other device comprising suitable circuitry for reading the RFID-tag.

According to a second aspect of the present invention, an assemblycomprising a first and second device according to any of thepreceding claims is provided. For example, in one embodiment, thefirst separate component may be a socket or a bit holder and the second separate component may be a quick change adapter.

Further objectives of, features of and advantages of the presentinvention will become apparent when studying the following detaileddisclosure, the drawings and the appended claims. Those skilled in the art realize that different features of the present invention can be combined to create embodiments other than those described in the following.Brief description of the drawings The invention will be described in the following illustrative andnon-limiting detailed description of exemplary embodiments, with reference to the appended drawing, on which Figure 1 is a cross sectional view of an exemplary torque transferring device according to a first embodiment.

Figure 2 is a cross sectional view of an exemplary torque transferring device according to a second embodiment.

Figures 3a and b are both side views of an exemplary torque transferring device according to the first or second embodiment.

Figure 4 is a cross sectional view of an exemplary torque transferring device according to a third embodiment.

Figure 5 is a cross sectional view of an exemplary torque transferring device according to a fourth embodiment.

A11 figures are schematic, not necessarily to scale and generallyonly show parts which are necessary in order to elucidate the invention, wherein other parts may be omitted or merely suggested.

Detailed description An exemplary torque transferring device 1 for use with a power toolaccording to a first embodiment is shown in a cross sectional viewin Figure 1. The illustrated exemplary device 1 is a socket 1comprising a first portion 10 and a second portion 20. The firstportion 10 comprises a first portion 11 of a tubular body 110 havinga first diameter D1 and a first inner element 12 made of metal,where a first engaging structure 13 is arranged at a front end 10aof the first portion and adapted to engage a nut to transfer torquethereto, i.e. to tighten a joint. The second portion 20 similarlycomprises a second portion 21 of the tubular body having a diameterD2 and a second engaging structure 22, in the illustrated embodiment a square female input 22, for connection to the output shaft of a l0 power tool arranged at a rear end portion 20b of the second bodypart. Examples of a respective first and second engaging structurel3, 22 are also shown in figures 3a and b. It should be noted thatthe illustrated embodiment may just as well be a quick changeadapter, where the difference would be that the first engagingstructure l3 would instead be for example a female Hex output adapted to engage a bit or nut setter instead of a socket.

An inner insulating element 30 is provided inside said secondportion of the tubular body 2l. This inner insulating element 30 isrotatably coupled to the first engaging structure and hence thefirst inner element l2 by means of a first male hex shaped structure3la, extending in an axial direction at a first end 3l of theinsulating element 30 engaging a corresponding female hex structurel2a arranged in the first inner element l2, and further by means ofa fastening element, here a spring pin 50 arranged between the firstinner element l2 and the insulating inner component 30 such that atorque may be transferred there between and consequently from thetool to the joint. The second engaging structure 22 is in theillustrated embodiment arranged in, i.e. forms part of, the innerinsulating element 30. Further, the inner insulating element 30 ismade of an electrically insulating material, such as a polymer.Hereby, for operator protecting purposes, an electrical insulationis formed between the first engaging structure l3 and the secondengaging structure 22, i.e. between the joint and the tool and hence the hand of the operator holding the tool.

The inner insulating element 30 has a substantially cylindricalshape, i.e. it has a cylindrical portion 3l which has approximatelythe same diameter as the inner diameter of the adjacent portion ofthe second portion 2l of the tubular body. And further, as explainedabove, comprises a square female input 22 for connection to the output shaft of a power tool.

In order to further enhance the operator protection, the tubularbody ll0 in the illustrated embodiment forms a freely rotatablesleeve 60 made of an electrically insulating material and provided on the outside of the first and second portion l0,20. ll In the illustrated embodiment of fig l, the total length of thesocket is approximately 50 mm, whereas the first diameter Dl isapproximately 20 mm and the second diameter D2 is approximately 25 mm.

Turning to figure 2, another exemplary torque transferring device laccording to a second embodiment is shown in a cross sectional view.The socket l comprises a first portion l0 and a second portion 20,where the first portion l0 comprises a first portion of the tubularbody ll having a first diameter Dl and a first inner element l2 madeof metal, a first engaging structure l3 is arranged at a front endl0a of the first portion and adapted to engage a nut to transfertorque thereto, i.e. to tighten a joint. The second portion 20similarly comprises a second portion of the tubular body 2l having adiameter D2 and a second engaging structure 22, in the illustratedembodiment a square female input 22, for connection to the outputshaft of a power tool arranged at a rear end portion 20b of thesecond body part. Examples of a respective first and second engaging structure l3, 22 are also shown in figures 3a and b.

In the second embodiment, an inner insulating element 30 is providedinside said second portion of the tubular body 2l, the innerinsulating element 30 comprising a cylindrical portion having adiameter D3 which is approximately the same as the inner diameter ofthe second tubular element 2l. This inner insulating element 30 isrotatably coupled to the first engaging structure l3 by means of amale hex structure 3la and a spring pin 50 arranged between thefirst inner element l2 and the insulating inner component 30.Further, the inner insulating element 30 is made of an electrically insulating material, such as a polymer.

In contrast to the first embodiment however, the device shown infig. 2 comprises a further inner element 40 arranged at the rear end20b. The further inner element 40 is rotatably coupled to the innerinsulating element such that a torque may be transferred, thissimilarly as described above by a second male hex shaped structure32b, extending in an axial direction at a second end 32 of theinsulating element 30 engaging a corresponding female hex structure 4l arranged in the further inner element 40, and further by means of l2 a second spring pin arranged between the further inner element 40and the insulating inner component 30 such that a torque may betransferred. Further the second engaging structure 22 for connectionto the output shaft of a power tool is arranged in the further innerelement 40. In the illustrated embodiment, the further inner element40 is made of metal. This provides increased strength to the socket(i.e. the device), but poses no problem with regards to electricalshock protection since the inner insulating element 30 arrangedbetween the first engaging structure and the second as above ensuresthat the required insulation is formed between the first engagingstructure l3 and the second engaging structure 22, i.e. between thejoint and the tool. As in figure l, the tubular body ll0 forms afreely rotatable sleeve 60 made of an electrically insulatingmaterial provided on the outside of the first and second portion l0,20. Further, the total length of the socket shown in fig. 2 is approximately 60 mm.

Figure 4 shows a third embodiment of the device, a so called quickchange adapter. This embodiments is similar to the embodimentdescribed above with reference to figure 2 in that the illustratedquick change adapter comprises a first portion l0 and a secondportion 20. The first portion l0 comprises a first portion of thetubular body ll0 having and a first inner element l2 made of metal,a first engaging structure l3 is arranged at a front end l0a of thefirst portion. In the quick change adapter, this structure l3 is afemale hex-structure l3 adapted to engage for example a bit holderhaving a rear male hex structure and transfer torque thereto. Thesecond portion 20 similarly comprises a second portion of thetubular body and a second engaging structure 22 arranged in afurther inner element 40 at a rear end portion 20b of the secondbody part, in the illustrated embodiment a square female input 22, for connection to the output shaft of a power tool.

An inner insulating element 30 is provided inside the tubular bodyll0 and is rotatably coupled to the first engaging structure l3 bymeans of a male hex structure 3la and to the further inner element 40 by means of a second male hex shaped structure 32b. 13 As in figures 1 and 2, the tubular body 110 forms a freely rotatablesleeve 60 made of an electrically insulating material provided on the outside of the first and second portion 10, 20.

Turning to fig 5, yet another alternative embodiment of the device 1is shown which is adapted to be arranged at least partly within thehead of the power tool, i.e. a so called flush socket where thesecond engaging structure 22 is a structure adapted to be arrangedin and engage the output shaft of the tool in an inner space of the power tool head (not shown).

The flush socket 1 comprises a first portion 10 and a second portion20, the first portion 10 and the second portion 20 being. The firstportion 10 comprising a first portion 11 of a tubular body 110having a first smaller diameter and a first inner element 12 made ofmetal, a first engaging structure 13 is arranged at a front end 10aof the first portion and adapted to engage a fastening element totransfer torque thereto, i.e. to tighten a joint. The first engaginginner element in this embodiment comprises an integrated bit, i.e.the structure 13 is a bit. The second portion 20 is as mentionedabove in this embodiment adapted to be arranged in a space in thetool head to achieve a compact, flush arrangement and comprises asecond portion 21 of the tubular body having a larger diameter and a second engaging structure 22 adapted to engage the tool output.

The insulating element 30 in this embodiment is provided inside thetubular body 110 which also forms a freely rotatable sleeve 60 madeof an electrically insulating material, and is as described aboverotatably coupled to the first engaging structure and hence thefirst inner element 12 by means of a first male hex shaped structure31a engaging a corresponding female hex structure arranged in thefirst inner element 12 and to the second portion 22 by means of asecond male hex shaped structure 32b, engaging a correspondingfemale hex structure 221 arranged in the second portion 22. Theinner insulating element 30 in this embodiment further has a middleportion cylindrical portion which has a larger diameter forming a collar.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and l4 description are to be considered illustrative or exemplary and notrestrictive; the invention is not limited to the disclosedembodiments. The skilled person understands that many modifications,variations and alterations are conceivable within the scope asdefined in the appended claims. For example, the invention may apartfrom the sockets and quick change adapter of the illustratedembodiments just as well be realized as an adapter or extension, oras a bit holder. Further, in some embodiments, insulation in theaxial and radial direction is provided by the inventive device, forexample in the form of a quick change adapter, combined with as aseparate socket or bit holder radially insulted by means a sleeve ofthe type described above or possibly a bit comprising an insulated sleeve.

Additionally, variations to the disclosed embodiments can beunderstood and effected by those skilled in the art in practicingthe claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does \\ ll not exclude other elements or steps and the indefinite article a \\ ll or an does not exclude a plurality. The mere fact that certainmeasures are recited in mutually different dependent claims does notindicate that a combination of these measures cannot be used toadvantage. Any reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

1. A torque transferring device (1) for a power tool, comprising afirst portion (10) comprising a first portion (11) of a tubularbody (110) and a first inner element (12) comprising a firstengaging structure (13) arranged at a front end (10a) of saidfirst portion and adapted to engage a corresponding matingstructure to transfer torque thereto, and a second portion (20)comprising a second portion (12) of said tubular body (110) anda second engaging structure (22) for connection to the outputshaft of a power tool arranged at a rear end portion (20b) of said second part, wherein an inner insulating element (30) is provided inside said tubular body, wherein said inner insulating element is rotatably coupledto said first engaging structure arranged at said front end of saidfirst portion and to said second engaging structure arranged at saidrear end of said second body element such that a torque may be transferred there between, and wherein said inner insulating element is made of anelectrically insulating material, such that for operator protectingpurposes an electrical insulation is formed between said first engaging structure and said second engaging structure.

2. Torque transferring device according to claim 1, whereinsaid inner insulating element comprises a substantiallycylindrical portion (31) having a diameter correspondingto an inner diameter of an adjacent portion (23) of said tubular body.

3. Torque transferring device according to claim 1 or 2,wherein said second engaging structure for connection tothe output shaft of a power tool is arranged in said inner insulating element. l6

4. Torque transferring device according to any of claims lor 2, wherein said second portion (20) comprises afurther inner element (40) arranged at said rear end(20b), wherein said further inner element (40) isrotatably coupled to said inner insulating element suchthat a torque may be transferred there between andwherein said second engaging structure for connection tothe output shaft of a power tool is arranged in said further inner element (40).

5. Torque transferring device according to claim 4, wherein said further portion is made of metal.

6. Torque transferring device according to any of thepreceding claims, wherein said first engaging structurearranged at said front end of said first portion is made of metal.

7. Torque transferring device according to any of thepreceding claims, wherein said insulating inner elementis rotatably coupled to said first inner element bymeans of a coupling between a first male hex shapedstructure (3la) comprised by said inner insultingelement and a corresponding female hex-shape structure (l2a) comprised by said first inner element.

8. Torque transferring device according to any of thepreceding claims 4-7, wherein said inner insulatingelement is rotatably coupled to said further innerelement by means of a coupling between a second male hexshaped structure (32a) comprised by said inner insultingelement and a corresponding female hex-shape structure (4l) comprised by said further inner element.

9. Torque transferring device according to any of thepreceding claims, wherein said first inner element and said inner insulating element are rotatably coupled by 17 means of a pin (50) arranged between said first innerelement and said inner insulating element, such that a torque may be transferred there between.

10. Torque transferring device according to any of thepreceding claims, wherein said torque transferringdevice is a component chosen from the group socket, quick change adapter or bit holder.

11. Torque transferring device according to claim 10,wherein said device is a socket or a bit holder, andwherein said engaging portion arranged at a front endthereof adapted to engage a corresponding matingstructure to transfer torque thereto, is a portion adapted to engage a nut or a bit.

12. Torque transferring device according to claim 10,wherein said device is a quick change adapter, andwherein said engaging portion arranged at a front endthereof adapted to engage a corresponding matingstructure to transfer torque thereto, is an adapter output adapted to engage a bit, socket or bit holder.

13. Torque transferring device according to any of thepreceding claims, wherein the device further comprises a freelyrotatable outer sleeve (60) for operator protecting purpose, and wherein said sleeve is made of an electrically insulating material.

14. Torque transferring device according to claim 12 or 13,wherein said freely rotatable sleeve (60) is formed by said tubular body (110).