Tool holding devices, threaded inserts, rotatable shafts and drilling units

Abstract

The present disclosure relates to a tool holding device (1, 1', 1") comprising a rotatable shaft (2, 2', 2") which is at least connectable to a tool drive power source (3) and comprises a first shaft thread (4, 4'). The tool holding device (1, 1', 1") comprises a threaded insert (5, 5'), which comprises a first insert thread (6, 6'), which is suitable for engaging the first shaft thread (4, 4') to form a first thread arrangement structure (4, 6; 4', 6'). The threaded insert (5, 5') comprises a second insert thread (7), which is suitable for engaging a tool thread (8) of a tool holding device (9), which tool thread is arranged to be screwed onto the second insert thread (7) to form a second thread arrangement structure (7, 8), the first thread arrangement structure (4, 6; 4', 6') having a larger pitch than the second thread arrangement structure (7, 8).

Description

Technical Field

[0001] The present disclosure relates to a tool holding arrangement comprising a rotatable shaft which is at least connectable to a drilling unit and comprises a first shaft thread. Background Art

[0002] Construction machines are used, for example, when renovating, rebuilding and extending buildings. Drill motors with a rotatable drive shaft are often used to drill holes, for example for pipes in floors and walls of buildings. Tool holders are used to connect a tool (e.g. a drill) to the drive shaft, wherein the tool is attached to the tool holder; for example by welding.

[0003] The connection between the drive shaft and the tool holder is usually achieved by a thread, wherein the tool holder is screwed onto the drive shaft. However, this arrangement has the disadvantage that the tool holder may be difficult to release from the drive shaft when the drilling operation is completed. Therefore, other types of connections between the drive shaft and the tool holder have been proposed.

[0004] In US 2004 / 0154838, a tool holder is mounted on a drive shaft for co-rotation therewith. The tool holder is adapted to mount and remove an annular hollow drill bit by means of coaxially arranged corresponding guide members, splines and tapered surfaces engaging one another. For fixed mounting, a threaded flange on the hollow drill bit is screwed onto a corresponding thread on the tool holder.

[0005] WO 2014126525 discloses a tool holding device comprising a plurality of components including a sleeve flange component.

[0006] However, there remains a need for a less complex and easier to manage tool holding device that enables easier release of the tool holder from the drive shaft when the drilling operation is completed. Summary of the invention

[0007] The object of the present invention is to provide an easy to manage and uncomplicated tool holding device which makes it easier to release the tool holder from the drive shaft when the drilling operation is completed.

[0008] This object is achieved by a tool holding device, the tool holding device comprising a rotatable shaft, the rotatable shaft being connectable to at least a drilling unit and comprising a first shaft thread. The tool holding device comprises a threaded insert, the threaded insert comprising a first insert thread and a second insert thread, the first insert thread being adapted to engage the first shaft thread to form a first thread arrangement, the second insert thread being adapted to engage a tool thread of the tool holding device, the tool thread being arranged to be screwed onto the second insert thread to form a second thread arrangement. The first thread arrangement has a larger pitch than the second thread arrangement.

[0009] In this way, the tool can be released from the rotatable drive shaft more easily than previously possible.

[0010] According to some aspects, the first thread arrangement is adapted for initial loosening of the tool holding device when the tool holding device is to be released, and the second thread arrangement is adapted for subsequent release of the tool holding device.

[0011] In this way, an improved release process can be achieved.

[0012] According to some aspects, a tool holding apparatus includes an outer sleeve adapted to retain a threaded insert in movably engagement with a rotatable shaft by being secured to the rotatable shaft.

[0013] According to some aspects, the threaded insert includes a flange and the outer sleeve includes a first hole and a second hole, the first hole allowing the flange to pass through and the second hole is suitable for retaining the flange by a circumferentially extending edge so that when the outer sleeve is mounted to the rotatable shaft, the threaded insert remains movably engaged with the rotatable shaft.

[0014] In this manner, the threaded insert is effectively maintained in movably engagement with the rotatable shaft.

[0015] According to some aspects, the outer sleeve includes sleeve threads adapted to engage the shaft outer threads such that the outer sleeve can be screwed onto the rotatable shaft.

[0016] In this way, the sleeve and the threaded insert can be easily released from the rotatable shaft.

[0017] According to some aspects, the threaded insert includes a first bearing surface, the tool holding device includes a second bearing surface, and the outer sleeve includes a third bearing surface, the second bearing surface being secured against the third bearing surface prior to initial release of the tool holding device. The first bearing surface is adapted to engage with the second bearing surface of the tool holding device during subsequent release of the tool holding device.

[0018] According to some aspects, a friction reducing element is arranged at the first bearing surface.

[0019] In this way, possible friction between the first bearing surface and the second bearing surface is reduced, so as to facilitate friction in the thread arrangement.

[0020] According to some aspects, the tool holding apparatus includes a locking pin arrangement structure wherein at least one locking pin is positioned between the rotatable shaft and the threaded insert. The locking pin is adapted to travel in a circumferentially extending groove formed in the threaded insert such that the threaded insert is held in movably engagement with the rotatable shaft.

[0021] In this manner, the threaded insert is effectively maintained in movably engagement with the rotatable shaft.

[0022] According to some aspects, each locking pin is adapted to travel in a circumferentially extending groove between an initial loosening of the tool retaining device and a subsequent release of the tool retaining device.

[0023] In this way, an enhanced release process can be achieved.

[0024] According to some aspects, the threaded insert includes a first bearing surface and the tool holder includes a second bearing surface.After initial loosening of the tool holder via the first thread arrangement, the first bearing surface is adapted to engage the second bearing surface of the tool holder during subsequent release of the tool holder.

[0025] According to some aspects, a sealing device is disposed between the rotatable shaft and the threaded insert.

[0026] In this way, dust and liquids are prevented from entering the rotatable shaft.

[0027] According to some aspects, the tool holder is adapted to be attached to a tool that is one of a drill, a concrete mixer, and a cutting tool.

[0028] According to some aspects, the first thread arrangement has a pitch that spans 10-40 mm / turn, and wherein the second thread arrangement has a pitch that spans 1-10 mm / turn.

[0029] According to some aspects, the rotatable shaft is adapted to be attached to the implement drive shaft by a third thread arrangement having the same characteristics as the second thread arrangement.

[0030] According to some aspects, the rotatable shaft is fixedly mounted to the core drilling unit.A threaded insert, a rotatable shaft and a drilling unit associated with the above advantages are also disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present disclosure will be described in more detail below with reference to preferred embodiments and the accompanying drawings, in which:

[0032] Figure 1shows a perspective view of an assembled tool holding device according to a first example;

[0033] Figure 2 shows an exploded side cross-sectional view of a tool holding device according to a first example;

[0034] Figure 3 shows a side cross-sectional view of a tool holding device in a first position according to a first example;

[0035] Figure 4 shows a side cross-sectional view of a tool holding device in a second position according to a first example;

[0036] Figure 5 shows a side cross-sectional view of a tool holding device in a first position according to a second example;

[0037] Figure 6 a perspective view showing an assembled tool holding device according to a second example; and

[0038] Figure 7 Shown is a perspective view of a conventional power tool driver with a pre-installed standard shaft and an assembled tool holding device according to a third example. DETAILED DESCRIPTION

[0039] Various aspects of the present disclosure will now be described more fully with reference to the accompanying drawings. However, the different devices disclosed herein may be implemented in many different forms and should not be construed as limited to the aspects set forth herein. The same reference numerals in the accompanying drawings always represent the same elements.

[0040] The terms used herein are only used to describe various aspects of the present disclosure and are not intended to limit the present invention.As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0041] refer to Figure 1 , shows a first example, having a tool holding device 1 comprising a rotatable shaft 2, which is here shown connected to a power tool driver 3. The power tool driver 3 is only partially shown, is of conventional type, and will not be discussed further here.

[0042] Also refer to Figure 2 , shows an exploded view of a tool holding device 1, to which a tool holding means 9 is arranged to be attached and also arranged to be fastened to a suitable tool, such as a drill 18, only partially indicated by, for example, welding to a surface facing away from the power tool driver 3 when mounted. According to some aspects, the tool holding device 1 and the tool 18 may alternatively be formed as an integral unit.

[0043] According to the present disclosure, a tool holding device 1 comprises a threaded insert 5, comprising a first insert thread 6, which is adapted to engage a first shaft thread 4 included in a rotatable shaft 2 to form a first thread arrangement 4, 6, wherein, in this example, the first shaft thread 4 is an internal thread and the first insert thread 6 is an external thread. The threaded insert 5 comprises a second insert thread 7 adapted to engage a tool thread 8 of a tool holding device 9, wherein the tool thread 8 is arranged to be screwed onto the second insert thread 7 to form a second thread arrangement 7, 8. In this example, the second insert thread 7 is an external thread and the tool thread 8 is an internal thread. The first thread arrangement 4, 6 has a larger pitch than the second thread arrangement 7, 8.

[0044] The tool holding device 1 comprises an outer sleeve 10 adapted to hold a threaded insert 5 in movably engagement with a rotatable shaft 2 by being fastened to the rotatable shaft 2. Here, the outer sleeve 10 comprises a sleeve thread 19 adapted to engage an outer shaft thread 20, such that the outer sleeve 10 can be screwed onto the rotatable shaft 2. The threaded insert 5 is held in that the threaded insert 5 comprises a flange 11, and the outer sleeve 10 comprises a first hole 12 allowing the flange 11 to pass through and a second hole 13 adapted to hold the flange 11 by means of a circumferentially extending edge 17. Thus, when the outer sleeve 10 is mounted to the rotatable shaft 2, the threaded insert 5 is held in movably engagement with the rotatable shaft 2.

[0045] The threaded insert 5 comprises a first bearing surface 14, the tool holding device 9 comprises a second bearing surface 15, and the outer sleeve 10 comprises a third bearing surface 16. Figure 4 In the embodiment of the present invention, the tool holder 9 is fixed to the rotatable shaft 2, wherein the second bearing surface 15 is fixed to the third bearing surface 16 before the initial loosening of the tool holder 9. The loosening is achieved by rotating the tool 18 and / or the tool holder 9, and for the loosening to take place, the friction between the second bearing surface 15 and the third bearing surface 16 on the one hand and the thread friction on the other hand must be overcome.

[0046] When the tool holding device 9 is to be released, the first thread arrangement 4, 6 is suitable for the initial loosening of the tool holding device 9, and the second thread arrangement 7, 8 is suitable for the subsequent release of the tool holding device 9, such as Figure 3 The initial release at least includes the disengagement of the second bearing surface 15 from the third bearing surface 16 .

[0047] This means that the initial loosening is relatively simple due to the first thread arrangement 4 , 6 having a relatively large pitch, and wherein the further unscrewing of the tool holder 9 takes place by means of the second thread arrangement 7 , 8 having a smaller pitch.

[0048] According to some aspects, the smaller pitch of the second thread arrangement 7, 8 complies with tool standards and according to some further aspects is suitable for preventing the tool from being accidentally loosened. It is contemplated that there may be a plurality of threaded inserts 5 to choose from, each threaded insert comprising a different type of second insert thread 7 to meet different standards of tool threads 8 of the tool holding device 9, while the first insert thread 6 according to some aspects is the same for all threaded inserts 5.

[0049] like Figure 3 As shown, after the initial loosening of the tool holder 9 via the first thread arrangement 4, 6, during the subsequent release of the tool holder 9, the first bearing surface 14 can engage with the inner portion 15a of the second bearing surface 15 of the tool holder 9. The first bearing surface 14 and the inner portion 15a are inclined in a mutually similar manner with respect to the rest of the second bearing surface 15, such that the friction between the bearing surface 14 and the inner portion 15a is reduced.

[0050] According to some aspects, it is desirable to further reduce possible friction between the first bearing surface 14 and the second bearing surface 15 to facilitate friction in the thread arrangement 4, 6; 4', 6'; 7, 8, as will be discussed later. In the case of low friction in the thread arrangement 4, 6; 4', 6'; 7, 8, the second bearing surface 15 can be disengaged from the first bearing surface 14 and the third bearing surface 16 more or less simultaneously.

[0051] The outer sleeve 10 is not necessary, as shown in the second example below. Figure 5 As shown, Figure 5 Corresponds to Figure 3 .exist Figure 5 In the embodiment, the tool holding device 1' comprises a rotatable shaft 2' connected to a power tool driver 3. A tool holding means 9 is arranged to be attached to the tool holding device 1' and also arranged to be fastened to a suitable tool, such as a drill 18, as only partially indicated in the first example.

[0052] Similarly, the tool holding device 1' comprises a threaded insert 5' comprising a first insert thread 6' adapted to engage a first shaft thread 4' comprised in the rotatable shaft 2' to form a first thread arrangement 4', 6'. The threaded insert 5' comprises a second insert thread 7 adapted to engage a tool thread 8 of the tool holding device 9', wherein the tool thread 8 is arranged to be screwed onto the second external thread 7 to form a second thread arrangement 7, 8. The first thread arrangement 4', 6' has a larger pitch than the second thread arrangement 7, 8.

[0053] In this example, the first shaft thread 4 ′ is an internal thread, the first insert thread 6 ′ is an external thread, the second insert thread 7 is an external thread, and the tool thread is an internal thread.

[0054] In the same way as in the first example, initial loosening of the tool holder 9 is relatively easy due to the relatively large pitch of the first thread arrangement 4 ′, 6 ′, and further unscrewing of the tool holder 9 takes place by means of the second thread arrangement 7 , 8 with a smaller pitch.

[0055] Here, the tool holding device 1 ' comprises a locking pin arrangement in which two locking pins 22, 23 are positioned between the rotatable shaft 2' and the threaded insert 5'. Each locking pin 22, 23 is adapted to travel in a circumferentially extending groove 24 formed in the threaded insert 5', such that the threaded insert 5' remains movably engaged with the rotatable shaft 2' as long as the locking pins 22, 23 are inserted into position.

[0056] The threaded insert 5' comprises a first bearing surface 14 and the tool holder 9 comprises a second bearing surface 15. The first bearing surface 14 is adapted to engage the second bearing surface 15 of the tool holder 9 during subsequent release of the tool holder 9 after initial loosening of the tool holder 9 via the first thread arrangement 4', 6'.

[0057] Locking pins 22 and 23 are also Figure 6 is shown in a perspective view.

[0058] Each locking pin 22, 23 is adapted to travel in a circumferentially extending groove 24 between initial loosening of the tool holding device 9 and subsequent release of the tool holding device 9. The locking pins 22, 23 are releasable such that the threaded insert 5' can be removed from the rotatable shaft 2'.

[0059] The term "locking pin" does not necessarily refer to a pin-shaped item, but in general other shapes are possible.

[0060] According to some aspects, a sealing device 25 is arranged between the rotatable shaft 2' and the threaded insert 5', such as Figure 5 Of course, such a sealing element can also be applied to the first example, although not shown. An alternative placement of the sealing device 26 is shown at a position closer to the tool drive 3. This can also constitute an additional sealing device.

[0061] According to some aspects, for both examples, in order to reduce possible friction between the first bearing surface 14 and the second bearing surface 15, a friction reducing element, such as a PTFE (polytetrafluoroethylene) gasket 21 (only for Figure 2). Such an element 21 is adapted to reduce the friction between the first bearing surface 14 and the second bearing surface 15. For clarity, the washer 21 is shown below the first bearing surface 14, but when the tool holding device is installed, the washer will be adjacent to the first bearing surface 14.

[0062] Typically, during installation, contact between the first and second bearing surfaces 14, 15 enables the threaded insert 5, 5' to be moved axially into the rotatable shaft 2, 2' such that the first insert threads 6, 6' engage the first shaft threads 4, 4' to form a first thread arrangement 4, 6; 4', 6'.

[0063] The friction reducing element may be of any type, such as a washer, an O-ring, or a surface treatment of the first bearing surface 14 as described above. Of course, the inclusion of any such friction reducing element is optional.

[0064] The present disclosure is not limited to the above, but may be varied freely within the scope of the appended claims.For example, the rotatable shaft 2, 2' may not be directly connected to the power tool driver 5, but may constitute an intermediate component.

[0065] The rotatable shafts 2, 2', the threaded inserts 5, 5' and the tool 18 are shown as being hollow, but one or more of these components may of course be solid.

[0066] The first thread arrangement 4, 6; 4', 6' comprises threads which may be of any suitable shape, forming any type of matching protrusions / recesses. According to some aspects, these threads may be made of a single element, such as a pin or a key.

[0067] According to some aspects, the tool holding device 1 , 1 ' may include a resilient element, such as a spring (not shown), which biases the threaded insert 5, 5' towards a particular position.

[0068] The outer sleeve 10 may be fastened to the rotatable shaft 2 in a variety of ways, such as by a press fit or a snap fit.

[0069] According to some aspects, the first thread arrangement 4, 6; 4', 6' has a pitch spanning 10-40 mm / turn, and the second thread arrangement 7, 8 has a pitch spanning 1-10 mm / turn. Of course, other pitches are also contemplated, for example depending on the size of the rotatable shaft 2, 2', the threaded insert 5, 5' and the tool holding device 9.

[0070] In the example shown, the rotatable shaft 2, 2' according to the present disclosure has been shown mounted to a power tool driver 3. Here, the power tool driver 3 is adapted to directly receive the rotatable shaft 2, 2' according to the present disclosure. However, the rotatable shaft and tool holding device according to the present disclosure may be adapted to be mounted to a tool driver having a normal standard shaft, which is adapted to be mounted directly to a tool holder.

[0071] According to some aspects, reference is made to a third example Figure 7 , there is a power tool driver 3 ″ having a standard shaft 27 suitable for direct mounting to a tool holder via a standard thread 28 suitable for engaging e.g. Figure 2 The tool thread 8 of the tool holding device 9 is shown. However, there is a tool holding device 1 ″ comprising a shaft 2 ″ which in turn comprises a standard shaft thread 29 adapted to engage a standard thread 28 of a standard shaft 27 to form a third thread arrangement 28 , 29 .

[0072] Thus, the rotatable shaft 2" is adapted to be attached to the standard shaft 27 by means of a third thread arrangement 28, 29 which, according to some aspects, has the same characteristics as the second thread arrangements 7, 8. The other components of the tool holding device 1" may be of the same type as discussed in the previous examples.

[0073] In this way, the rotatable shaft provided with a standard shaft thread 29 enables the tool holding device 1 ″ to be mounted to a conventional tool driver 3 ″ having a plain standard shaft 27 suitable for direct mounting to a tool holder.

[0074] The electric tool drive 3 usually consists of a tool drive power source in the form of a drill unit 3, for example, which can be operated by hand or with the aid of a motor, which can be of the electric or combustion type.

[0075] According to some aspects, the first shaft threads 4, 4' are external threads and the first insert threads 6, 6' are internal threads, wherein these threads are adapted to engage with each other to form a first thread arrangement.

[0076] The second insert thread 7 is usually an external thread, since the corresponding tool thread 8 of the tool holder is usually an internal thread. Of course, the opposite is also possible.

[0077] According to some aspects, the insert is held in movably engagement with the rotatable shaft by a tool holding device including an outer sleeve or by threads such as a locking pin, as previously described. Of course, many other devices and arrangements for holding a threaded insert in movably engagement with a rotatable shaft are contemplated, and generally the threaded insert is held in movably engagement with the rotatable shaft.

[0078] According to some aspects, the threaded insert is not held in movably engagement with the rotatable shaft, but can be unscrewed and released from the rotatable shaft. In this way, according to a first alternative, when the tool holder 9 is to be released, the first thread arrangement 4, 6; 4', 6' is adapted for an initial loosening of the tool holder 9, and the second thread arrangement 7, 8 is adapted for a subsequent release of the tool holder 9. According to a second alternative, it is conceivable that the first thread arrangement 4, 6; 4', 6' is adapted for an initial loosening of the tool holder and for at least a part of a subsequent release of the tool holder 9.

[0079] This means that the first thread arrangement 4 , 6 ; 4 ′, 6 ′ may be suitable for a complete loosening of the tool holding device.

[0080] Generally, the present disclosure relates to a tool holding device 1, 1', 1", which includes a rotatable shaft 2, 2', 2", which can be connected to at least a drilling unit 3 and includes a first shaft thread 4, 4'. The tool holding device 1, 1', 1" includes a threaded insert 5, 5', which includes a first insert thread 6, 6' and a second insert thread 7, the first insert thread is suitable for engaging the first shaft thread 4, 4' to form a first thread arrangement structure 4, 6; 4', 6', the second insert thread is suitable for engaging a tool thread 8 of a tool holding device 9, the tool thread is arranged to be screwed onto the second insert thread 7 to form a second thread arrangement structure 7, 8, the first thread arrangement structure 4, 6; 4', 6' having a larger pitch than the second thread arrangement structure 7, 8.

[0081] According to some aspects, the first thread arrangement 4 , 6 ; 4 ′, 6 ′ is adapted for initial loosening of the tool holding device 9 when the tool holding device 9 is to be released, and the second thread arrangement 7 , 8 is adapted for subsequent release of the tool holding device 9 .

[0082] According to some aspects, the tool holding device 1 comprises an outer sleeve 10 adapted to hold the threaded insert 5 in movably engagement with the rotatable shaft 2 by being fastened to the rotatable shaft 2 .

[0083] According to some aspects, the threaded insert 5 includes a flange 11, and wherein the outer sleeve 10 includes a first hole 12 allowing the flange 11 to pass therethrough and a second hole 13 adapted to retain the flange 11 via a circumferentially extending edge 17, such that when the outer sleeve 10 is mounted to the rotatable shaft 2, the threaded insert 5 remains movably engaged with the rotatable shaft 2.

[0084] According to some aspects, the outer sleeve 10 includes a sleeve thread 19 adapted to engage the outer shaft thread 20 such that the outer sleeve 10 can be screwed onto the rotatable shaft 2 .

[0085] According to some aspects, the threaded insert 5 includes a first bearing surface 14, the tool holding device 9 includes a second bearing surface 15, and the outer sleeve 10 includes a third bearing surface 16, the second bearing surface 15 being fixed against the third bearing surface prior to initial release of the tool holding device 9, and wherein the first bearing surface 14 is suitable for engaging the second bearing surface 15 of the tool holding device 9 during subsequent release of the tool holding device 9.

[0086] According to some aspects, a friction reducing element is arranged at the first bearing surface 14 .

[0087] According to some aspects, the tool holding device 1' includes a locking pin arrangement structure, wherein at least one locking pin 22, 23 is positioned between the rotatable shaft 2' and the threaded insert 5' and is adapted to travel in a circumferentially extending groove 24 formed in the threaded insert 5' so that the threaded insert 5' is maintained in movably engagement with the rotatable shaft 2'.

[0088] According to some aspects, each locking pin 22 , 23 is adapted to travel in the circumferentially extending groove 24 between an initial loosening of the tool retaining device 9 and a subsequent release of the tool retaining device 9 .

[0089] According to some aspects, the threaded insert 5' includes a first bearing surface 14 and the tool holding device 9 includes a second bearing surface 15, wherein the first bearing surface 14 is suitable for engaging the second bearing surface 15 of the tool holding device 9 during a subsequent release of the tool holding device 9 after the tool holding device 9 is initially loosened via the first threaded arrangement structure 4', 6'.

[0090] According to some aspects, a sealing device 25, 26 is arranged between the rotatable shaft 2, 2', 2" and the threaded insert 5, 5'.

[0091] According to some aspects, the tool holder 9 is adapted to be attached to a tool 18, the tool being one of:

[0092] - Drilling rig,

[0093] -concrete mixers, and

[0094] - Cutting tools.

[0095] According to some aspects, the first thread arrangement 4, 6; 4', 6' has a pitch spanning 10-40 mm / turn, and wherein the second thread arrangement 7, 8 has a pitch spanning 1-10 mm / turn.

[0096] According to some aspects, the rotatable shaft 2 ″ includes a standard shaft thread 29 adapted to engage a standard thread 28 of a standard shaft 27 included in the drilling unit 3 .

[0097] According to some aspects, the rotatable shaft 2 , 2 ′, 2 ″ is fixedly mounted to the core drilling unit 3 .

[0098] Generally, the present disclosure also relates to a threaded insert 5, 5' comprising a first insert thread 6, 6' and a second insert thread 7. The first insert thread 6, 6' is adapted to engage a first shaft thread 4, 4' of a rotatable shaft 2, 2', 2" to form a first thread arrangement 4, 6; 4', 6', and wherein the second insert thread 7 is adapted to engage an internal tool thread 8 of a tool holding device 9, which is arranged to be screwed onto the second insert thread 7 to form a second thread arrangement 7, 8, the first insert thread 6, 6' having a larger pitch than the second insert thread 7.

[0099] According to some aspects, the first thread arrangement 4 , 6 ; 4 ′, 6 ′ is adapted for an initial loosening of the tool holding device 9 and the second thread arrangement 7 , 8 is adapted for a subsequent release of the tool holding device 9 .

[0100] According to some aspects, the threaded insert 5 comprises a first bearing surface 14 adapted to engage a second bearing surface 15 of the tool holding device 9 during a subsequent release of the tool holding device 9 .

[0101] According to some aspects, a friction reducing element is arranged at the first bearing surface 14 .

[0102] According to some aspects, the threaded insert 5, 5' includes a locking pin arrangement structure, wherein at least one locking pin 22, 23 is adapted to be positioned between the threaded insert 5' and the rotatable shaft 2', and is adapted to travel in a circumferentially extending groove 24 formed in the threaded insert 5', so that the threaded insert 5' can be maintained in movably engagement with the rotatable shaft 2'.

[0103] According to some aspects, each locking pin 22 , 23 is adapted to travel in the circumferentially extending groove 24 between an initial loosening of the tool retaining device 9 and a subsequent release of the tool retaining device 9 .

[0104] According to some aspects, the threaded insert 5, 5' comprises sealing means 25, 26 adapted to be arranged between the threaded insert 5, 5' and the rotatable shaft 2, 2', 2".

[0105] According to some aspects, the first insert thread 6, 6' has a pitch spanning 10-40 mm / turn, and wherein the second insert thread 7 has a pitch spanning 1-10 mm / turn.

[0106] Generally, the present disclosure also relates to a rotatable shaft 2, 2', 2" connectable to at least a drilling unit 3. The rotatable shaft 2, 2', 2" comprises a first shaft thread 4, 4' adapted to engage a first insert thread 6, 6' of a threaded insert 5, 5' which in turn can be attached to a tool holding device 9.

[0107] According to some aspects, the first shaft thread 4, 4' has a pitch spanning 10-40 mm / turn.

[0108] According to some aspects, the rotatable shaft 2 ″ includes a standard shaft thread 29 adapted to engage a standard thread 28 of a standard shaft 27 included in the drilling unit 3 .

[0109] Generally, the present disclosure also relates to a drilling unit, such as a core drilling unit 3, comprising a tool holding device 1, 1', 1" according to any of the preceding claims 1 to 15.

Claims

1. A tool holding device (1, 1', 1'') comprising a rotatable shaft (2, 2', 2'') which is at least connectable to a drilling unit (3) and comprises a first shaft thread (4, 4'), characterized in that The tool holding device (1, 1', 1'') comprises a threaded insert (5, 5'), the threaded insert comprising a first insert thread (6, 6') and a second insert thread (7), the first insert thread being adapted to engage the first shaft thread (4, 4') to form a first thread arrangement structure (4, 6; 4', 6'), the second insert thread being adapted to engage a tool thread (8) of a tool holding device (9), the tool thread being arranged to be screwed onto the second insert thread (7) to form a second thread arrangement structure (7, 8), the first thread arrangement structure (4, 6; 4', 6') having a larger pitch than the second thread arrangement structure (7, 8); wherein the tool holding device (1) comprises an outer sleeve (10), the outer sleeve being adapted to hold the threaded insert (5) in movably engagement with the rotatable shaft (2) by being fastened to an outer surface of the rotatable shaft (2).

2. The tool holding device (1, 1', 1'') according to claim 1, wherein: The first thread arrangement (4, 6; 4', 6') is suitable for initial loosening of the tool holding device (9) when the tool holding device (9) is to be released, and the second thread arrangement (7, 8) is suitable for subsequent release of the tool holding device (9).

3. The tool holding device (1) according to claim 1, wherein: The threaded insert (5) comprises a flange (11), and wherein the outer sleeve (10) comprises a first hole (12) allowing the flange (11) to pass therethrough and a second hole (13) adapted to retain the flange (11) via a circumferentially extending edge (17), such that when the outer sleeve (10) is mounted to the rotatable shaft (2), the threaded insert (5) remains movably engaged with the rotatable shaft (2).

4. The tool holding device (1) according to claim 3, wherein: The outer sleeve (10) comprises a sleeve thread (19) adapted to engage an outer shaft thread (20) such that the outer sleeve (10) can be screwed onto the rotatable shaft (2).

5. The tool holding device (1) according to claim 3 or 4, wherein: The threaded insert (5) comprises a first bearing surface (14), the tool holding device (9) comprises a second bearing surface (15), and the outer sleeve (10) comprises a third bearing surface (16), the second bearing surface (15) being secured against the third bearing surface prior to initial release of the tool holding device (9), and wherein the first bearing surface (14) is adapted to engage the second bearing surface (15) of the tool holding device (9) during subsequent release of the tool holding device (9).

6. The tool holding device (1) according to claim 5, wherein: A friction reducing element is arranged at the first bearing surface (14).

7. The tool holding device (1') according to claim 1 or 2, wherein: The tool holding device (1') comprises a locking pin arrangement, wherein at least one locking pin (22, 23) is positioned between the rotatable shaft (2') and the threaded insert (5') and is adapted to travel in a circumferentially extending groove (24) formed in the threaded insert (5') such that the threaded insert (5') is held in movably engagement with the rotatable shaft (2').

8. The tool holding device (1 ') according to claim 7, wherein: Each locking pin (22, 23) is adapted to travel in the circumferentially extending groove (24) between initial loosening of the tool holding device (9) and subsequent release of the tool holding device (9).

9. The tool holding device (1 ') according to claim 7, wherein: The threaded insert (5') comprises a first bearing surface (14) and the tool holding device (9) comprises a second bearing surface (15), wherein the first bearing surface (14) is adapted to engage the second bearing surface (15) of the tool holding device (9) during a subsequent release of the tool holding device (9) after an initial loosening of the tool holding device via the first thread arrangement (4', 6').

10. The tool holding device (1, 1', 1'') according to claim 1 or 2, wherein: A sealing device (25, 26) is arranged between the rotatable shaft (2, 2', 2'') and the threaded insert (5, 5').

11. The tool holding device (1, 1', 1'') according to claim 1 or 2, wherein: The tool holding device (9) is adapted to be attached to a tool (18), the tool being one of: - Drilling rig, - concrete mixers, and - Cutting tools.

12. The tool holding device (1, 1', 1'') according to claim 1 or 2, wherein: The first thread arrangement (4, 6; 4', 6') has a thread pitch of 10-40 mm / turn, and wherein the second thread arrangement (7, 8) has a thread pitch of 1-10 mm / turn.

13. The tool holding device (1 '') according to claim 1 or 2, wherein: The rotatable shaft (2") comprises a standard shaft thread (29) adapted to engage a standard thread (28) of a standard shaft (27) comprised in a drilling unit (3).

14. The tool holding device (1, 1', 1'') according to claim 1 or 2, wherein: The rotatable shaft (2, 2', 2") is fixedly mounted to the core drilling unit (3).

15. A drilling unit comprising a tool holding device (1, 1', 1'') according to any of the preceding claims 1 to 14.

16. The drilling unit according to claim 15, wherein the drilling unit is a core drilling unit (3).

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