Coupling mechanism for tool and tool including the same

Abstract

To provide a tool including a coupling mechanism for the tool.SOLUTION: A coupling mechanism 18a for a tool includes: a driving part 20a being rotatable around a rotation axis 24, the driving part 20a including a driving profile; a driven part 22a being rotatable around the rotation axis 24, the driven part 22a including a driven profile 28 which is complementary to the driving profile and arranged so as to be fitted with the driving profile in a coupling position to transmit torque between the driving part and the driven part; and a lining-up mechanism 36a which is arranged so as to cause relative rotation between the driving part and the driven part around the rotation axis from a non-line-up state of the coupling mechanism in which the driving profile and the driven profile are not lined up in a rotation direction toward a line-up state of the coupling mechanism in which the driving profile and the driven profile are lined up in the rotation direction.SELECTED DRAWING: Figure 2a

Description

[Technical Field]

[0001] The present disclosure relates generally to coupling mechanisms. In particular, a coupling mechanism for a tool and a tool including such a coupling mechanism are provided. [Background technology]

[0002] Industrial power tools such as nutrunners are widely used in manufacturing industries, for example, in vehicle manufacturing and aerospace. Such power tools typically have a tool head that interacts with a workpiece and a body that is held by a user when operating the power tool. The body may alternatively form part of a robot.

[0003] In some applications it is desirable to have interchangeable tool heads that can be used for different applications in the manufacturing process, and to this end a tool head, such as an angle head, can be removably connected to the body. Summary of the Invention [Problem to be solved by the invention]

[0004] To attach the tool head to the body of the power tool, a hexagonal follower in the tool head may need to be rotationally aligned with a correspondingly shaped hexagonal drive in the tool body before the hexagonal faces mate. This can be difficult for the user, as they may not always have an unobstructed view of the mating faces, and there is also a risk that the faces will not mate properly.

[0005] One object of the present disclosure is to provide a coupling mechanism for a tool that can facilitate mating of a drive profile and a driven profile.

[0006] A further object of the present disclosure is to provide a coupling mechanism for a tool that allows for seamless mating of a driving profile and a driven profile.

[0007] A further object of the present disclosure is to provide a coupling mechanism for a tool, which coupling mechanism has an uncomplicated design.

[0008] It is yet another object of the present disclosure to provide a coupling mechanism for a tool, the coupling mechanism having a cost-effective design.

[0009] A further object of the present disclosure is to provide a coupling mechanism for a tool, which coupling mechanism operates reliably.

[0010] It is a further object of the present disclosure to provide a coupling mechanism for a tool, which coupling mechanism solves some or all of the aforementioned objects in combination.

[0011] A further object of the present disclosure is to provide a tool including a coupling mechanism, which solves one, some or all of the aforementioned objects. [Means for solving the problem]

[0012] According to a first aspect, there is provided a coupling mechanism for a tool, the coupling mechanism comprising: a drive part rotatable about an axis of rotation, the drive part including a drive profile; a followed part rotatable about the axis of rotation, the followed part including a followed profile complementary to the drive profile, the followed profile arranged to mate with the drive profile in a coupled position for torque transfer between the driver and followed part; and an alignment mechanism arranged to effect relative rotation between the drive part and the followed part about the axis of rotation from a misaligned state of the coupling mechanism, in which the drive profile is rotationally misaligned with the followed profile, to an aligned state of the coupling mechanism, in which the drive profile is rotationally aligned with the followed profile.

[0013] The alignment mechanism acts to align the driver and driven sections so that the drive and driven profiles are aligned during relative movement of the driver and driven sections along the rotational axis. In this manner, the drive and driven profiles are aligned when they mate. The coupling mechanism thereby allows for seamless mating of the drive and driven profiles. As a result, the coupling mechanism greatly facilitates attachment of the driven section to the driver. The coupling mechanism facilitates replacement of the tool head of the power tool.

[0014] One of the driver and follower can be male, such as a shaft, and the other can be female, such as a socket. The driver can be the input and the follower can be the output, or vice versa.

[0015] The alignment mechanism may be provided on the driver or the driven part and may be configured to apply a torque to the driver and / or driven part about the axis of rotation from an unaligned state towards an aligned state.

[0016] The follower portion may be movable relative to the drive portion along the rotational axis from a decoupled position in which the follower portion is decoupled from the drive portion, to an intermediate aligned position in which the drive profile or the follower profile is aligned with the alignment mechanism along the rotational axis, and to a coupled position in which the follower profile mates with the drive profile.

[0017] The alignment mechanism can be positioned to provide relative rotation between the driver and driven parts in the aligned position. To attach the driven part to the driver part, the driven part can thus be moved in a single continuous axial movement from an uncoupled position, where the alignment mechanism forces the driver and driven part into alignment, to a coupled position. As the driver and driven parts are moved toward each other along the rotation axis through the aligned position, the alignment mechanism applies an alignment torque along an alignment distance along the rotation axis. The alignment distance can be, for example, at least 30% of the shortest of the length of the drive profile along the rotation axis and the length of the driven profile along the rotation axis. The alignment distance allows a user to continuously move the driver and driven parts toward each other without necessarily having to have an alignment mechanism to align the driver and driven parts.

[0018] The alignment mechanism may comprise a spring, which may be, for example, a leaf spring or a coil spring, such as a compression coil spring.

[0019] The alignment mechanism can include one or more protruding elements, each arranged to apply a torque to the driving profile or the driven profile in a misaligned state, and the torque can be relatively large for relatively large rotational displacements between the driving and driven portions about the axis of rotation and relatively small for relatively small rotational displacements between the driving and driven portions about the axis of rotation.

[0020] The spring may be arranged to exert a force on one or more protruding elements radially relative to the axis of rotation, so that the protruding elements are arranged to move against deformation of the spring, or the protruding elements may be elastic.

[0021] The coupling mechanism may further comprise a chamfered edge arranged to apply a force to the one or more protruding elements against deformation of the spring upon relative movement between the driver and driven portions along the axis of rotation, for example, from a decoupled position to an aligned position. If the alignment mechanism is on the driver and the driven portion is female, the driven portion may include a chamfered edge arranged to urge the one or more protruding elements radially outward during relative movement between the driver and driven portions along the axis of rotation, at least when the two portions are not rotationally aligned. Conversely, if the alignment mechanism is on the driven portion and the driven portion is female, the drive portion may include a chamfered edge arranged to urge the one or more protruding elements radially inward during relative movement between the driver and driven portions along the axis of rotation, at least when the two portions are not rotationally aligned.

[0022] Each protruding element may include a rounded shape for contacting the driving profile or the driven profile. One or more of the protruding elements may be, for example, a ball or a cylinder.

[0023] The coupling mechanism may comprise a plurality of protruding elements, such as two, four, or six protruding elements. In this case, the protruding elements may lie in a common plane transverse to the axis of rotation. Alternatively or additionally, the protruding elements may be substantially evenly distributed around the axis of rotation. The coupling mechanism may comprise at least one pair of oppositely disposed (relative to the axis of rotation) protruding elements.

[0024] The drive profile and the driven profile may each have a polygonal shape, which may be, for example, a triangle, a square, a pentagon, or a hexagon.

[0025] The angular distance relative to the axis of rotation between two adjacent protruding elements may correspond to the angular distance relative to the axis of rotation between two edges of the polygonal shape.

[0026] An alignment mechanism may be provided on the drive section, where each protruding element may be aligned with a unique drive side and direction of rotation of the polygonal shape of the drive profile relative to the axis of rotation.

[0027] Alternatively, an alignment feature may be provided on the follower, in which case each protruding element may be rotationally aligned with a unique follower side of the polygonal shape of the follower profile relative to the axis of rotation.

[0028] According to a second aspect, there is provided a tool including a coupling mechanism according to the present disclosure. The tool may be a power tool, such as a power tool, a pneumatic tool or a hydraulic tool. The power tool may be, for example, a fastening tool.

[0029] The tool may comprise a body and an end effector removably attachable to the body. The end effector may be, for example, a tool head or a gear attachment. The driver may be provided on the body and the driven part may be provided on the end effector.

[0030] Further details, advantages and aspects of the present disclosure will become apparent from the following description taken in conjunction with the drawings. [Brief explanation of the drawings]

[0031] [Figure 1] 1 shows a schematic side view of a tool with a coupling mechanism; [Figure 2a] 1A and 1B schematically show a first perspective side view of the coupling mechanism in a decoupling position; [Figure 2b] 10A and 10B schematically show a second perspective side view of the coupling mechanism in a decoupling position; [Figure 3] 1A and 1B show schematic cross-sectional side views of a coupling mechanism in a decoupling position; [Figure 4a] 10 is a front view of the drive part of the coupling mechanism shown in FIG. [Figure 4b] 1 shows a schematic front perspective view of the drive unit. [Figure 5]1A and 1B are schematic cross-sectional side views of a coupling mechanism in an intermediate alignment position; [Figure 6] 1A and 1B are schematic cross-sectional front views of a coupling mechanism in a misaligned state; [Figure 7] 1A and 1B are schematic cross-sectional front views of the coupling mechanism in an aligned position; [Figure 8] 1 shows a schematic cross-sectional side view of a coupling mechanism in a coupled position. [Figure 9a] 10A and 10B schematically show a first perspective side view of another embodiment of a coupling mechanism in a decoupled position; [Figure 9b] 9b shows a second perspective side view of the coupling mechanism of FIG. 9a in a decoupled position; [Figure 10] 9a and 9b show schematic cross-sectional side views of the coupling mechanism of FIGS. 9a and 9b in a decoupling position; [Figure 11a] 9a and 9b show schematic front views of the driven part of the coupling mechanism; [Figure 11b] 9a and 9b show schematic front perspective views of the driven part of the coupling mechanism; [Figure 12] 9a and 9b in an intermediate alignment position; FIG. [Figure 13] 9a and 9b show schematic cross-sectional side views of the coupling mechanism of FIGS. 9a and 9b in a coupled position; DETAILED DESCRIPTION OF THE INVENTION

[0032] In the following, a coupling mechanism for a tool and a tool equipped with such a coupling mechanism are described, wherein the same or similar reference numerals are used to denote the same or similar structural features.

[0033] 1 shows a schematic side view of a power tool 10. The power tool 10 may be, for example, a nutrunner. The power tool 10 includes a body 12 having a handle 14. The power tool 10 further includes a tool head 16 removably connected to the body 12. In this example, the tool head 16 is an angle head. Alternatively, the tool head 16 may be a straight head.

[0034] The power tool 10 further includes a coupling mechanism 18a. The coupling mechanism 18a includes a driver 20a and a driven portion 22a. In this example, the driver 20a is provided on the body 12 and the driven portion 22a is provided on the tool head 16. In FIG. 1, the driver 20a is connected to the driven portion 22a for common rotation about an axis of rotation 24. The driver 20a can be rotationally driven by a power source internal or external to the body 12. The power source can be electric, pneumatic, or hydraulic.

[0035] Figure 2a schematically illustrates a first perspective side view of coupling mechanism 18a, and Figure 2b schematically illustrates a second perspective side view of coupling mechanism 18a. Referring generally to Figures 2a and 2b, coupling mechanism 18a is now in a decoupled position 26. In decoupled position 26, driver portion 20a and driven portion 22a are completely separated.

[0036] In this embodiment, driver 20a is a socket and follower 22a is a shaft. Figures 2A and 2B show a male follower profile 28 on follower 22a. Follower profile 28 is illustrated here as a hexagonal profile. That is, follower profile 28 has a hexagonal cross-sectional shape transverse to rotation axis 24. Follower profile 28 includes six follower sides 30 and six intermediate follower edges 32.

[0037] The follower 22a in this embodiment further comprises a chamfered edge 34a, which is located at the end of the follower 22a (the right end in FIG. 2a).

[0038] The coupling mechanism 18a further includes an alignment mechanism 36a. Here, the alignment mechanism 36a is provided in an alignment section 38a on the drive part 20a. The alignment mechanism 36a includes a spring 40a and a plurality of balls 42a, here two balls 42a arranged opposite to the rotation axis 24. Here, the spring 40a is a leaf spring that surrounds a cylindrical body 44 of the drive part 20a. The balls 42a are received in openings in the cylindrical body 44. The spring 40a presses the balls 42a radially inward from the outside of the cylindrical body 44 to a protruding position where the balls 42a protrude into the interior of the cylindrical body 44. The balls 42a are an example of a protruding element according to the present disclosure.

[0039] Figure 3 shows a schematic cross-sectional side view of the coupling mechanism 18a in the decoupling position 26. In Figure 3, it can be seen that the driver 20a includes a female drive profile 46. The drive profile 46 is complementary to the driven profile 28. Thus, in this embodiment, the drive profile 46 is also hexagonal. The drive profile 46 includes six drive sides 48 and six intermediate drive edges 50.

[0040] 3 further shows that the length of alignment section 38a along rotation axis 24 is approximately equal to the length of drive profile 46 along rotation axis 24. The length of alignment section 38a along rotation axis 24 can be, for example, at least 30% and / or less than 150% of the length of drive profile 46 along rotation axis 24. FIG. 3 further shows that balls 42a lie in a common plane that intersects rotation axis 24.

[0041] Figure 4a schematically illustrates a front view of drive section 20a, and Figure 4b schematically illustrates a front perspective view of drive section 20a. Collectively referring to Figures 4a and 4b, it can be seen that balls 42a are rotationally aligned with two opposing drive sides 48 of drive profile 46 relative to rotation axis 24. In the illustrated protruding position, each ball 42a is radially aligned with a drive side 48 relative to rotation axis 24. However, balls 42a can protrude slightly radially inward of drive sides 48.

[0042] FIG. 5 schematically illustrates a cross-sectional side view of coupling mechanism 18a in an intermediate alignment position 52. In alignment position 52, follower 22a has been moved along rotational axis 24 toward driver 20a such that follower profile 28 enters alignment section 38a of barrel 44 of driver 20a. Follower profile 28 is now aligned with alignment feature 36a along rotational axis 24. At alignment position 52, follower 22a moves along rotational axis 24 along alignment distance 54a. Throughout alignment distance 54a, follower profile 28 is positioned between ball 42a and drive profile 46 along rotational axis 24. As follower 22a moves through alignment distance 54a, follower profile 28 becomes rotationally aligned with drive profile 46 (if not already aligned), as described herein. This allows for easy and seamless mating of follower profile 28 and drive profile 46.

[0043] Figure 6 schematically illustrates a cross-sectional front view of coupling mechanism 18a in a misaligned condition 56. As shown in Figure 6, follower profile 28 has been rotated 30 degrees about rotation axis 24 relative to drive profile 46. This rotational position of follower portion 22a relative to drive portion 20a prevents follower profile 28 from entering and mating with drive profile 46.

[0044] When the driven profile 28 is inserted into the alignment section 38a, the chamfered edge 34a urges the ball 42a radially outward if the driven profile 28 is not rotationally aligned with the drive profile 46. By urging the ball 42a with the chamfered edge 34a rather than with a straight edge (transverse to the axis of rotation 24), retraction of the ball 42a is ensured in the misaligned condition 56. This contributes to more reliable operation of the coupling mechanism 18a.

[0045] In the misaligned state 56, the driven profile 28 simply obstructs the ball 42a within the aligned section 38a. As shown in FIG. 6, the driven profile 28 pushes the ball 42a radially outward against the deformation of the spring 40a. The ball 42a provides a small contact surface with the driven profile 28, which contributes to low friction relative movement between the driver portion 20a and the driven portion 22a, both axially and rotationally about the rotation axis 24.

[0046] Spring 40a exerts a restoring, radially inward force on ball 42a, which induces an aligning torque 58 on driven profile 28 toward alignment about axis of rotation 24 (clockwise in FIG. 6).

[0047] 7 schematically illustrates a cross-sectional front view of coupling mechanism 18a in aligned state 60. In aligned state 60, drive profile 46 and driven profile 28 are rotationally aligned about axis of rotation 24 for mating. Under the action of spring 40a, ball 42a is biased toward the smallest cross-sectional dimension of driven portion 22a, here toward the center of driven side 30. Ball 42a protrudes most when driven profile 28 is rotationally aligned with drive profile 46. In this manner, alignment mechanism 36a effects relative rotation between drive portion 20a and driven portion 22a about axis of rotation 24 from misaligned state 56 toward aligned state 60.

[0048] 8 shows a schematic cross-sectional side view of coupling mechanism 18a in coupling position 62, where driven profile 28 is mated with drive profile 46. Torque can be transmitted between driver portion 20a and driven portion 22a.

[0049] Figure 9a shows a first perspective side view of a further embodiment of a coupling arrangement 18b, and Figure 9b shows a second perspective side view of the coupling arrangement 18b of Figure 9a. The coupling arrangement 18b can replace the coupling arrangement 18a of the power tool 10 of Figure 1. The following mainly describes the differences between the coupling arrangement 18b and the coupling arrangement 18a.

[0050] 9A and 9B, coupling mechanism 18b is in the decoupling position 26. Coupling mechanism 18b includes a driver portion 20b, a follower portion 22b, and an alignment mechanism 36b. Here, alignment mechanism 36b is provided on follower portion 22b. Follower portion 22b includes an alignment section 38b forward of follower profile 28. Alignment mechanism 36b is provided on alignment section 38b.

[0051] The alignment mechanism 36b in this embodiment also includes two balls 42b, each in rotational alignment with a unique driven edge 32. Both the balls 42b (neutral state) and the driven edge 32 have the same radial extension.

[0052] Figure 10 schematically illustrates a cross-sectional side view of coupling mechanism 18b in the decoupling position 26. In Figure 10, it can be seen that alignment mechanism 36b further includes spring 40b, illustrated here as a compression coil spring. Spring 40b is located here within bearing 64 of alignment section 38b. Spring 40b urges balls 42b radially outward.

[0053] The driving portion 20b of this embodiment includes a chamfered edge 34b, which is disposed at the end of the cylindrical body 44 (the left end in FIG. 10).

[0054] Figure 11a shows a schematic front view of follower 22b, and Figure 11b shows a front perspective view of follower 22b. Referring generally to Figures 11a and 11b, it can be seen that drive profile 46 in this embodiment extends through the entire drive section 20b. Thus, drive section 20b in this embodiment does not include an alignment section.

[0055] 12 schematically illustrates a cross-sectional side view of coupling mechanism 18b in alignment position 52. Drive profile 46 is aligned with alignment mechanism 36b along rotation axis 24.

[0056] As alignment section 38b enters drive profile 46, if driver 20b is not rotationally aligned with follower 22b, chamfered edge 34b urges ball 42b radially inward against the deformation of spring 40b. Follower 22b moves along rotational axis 24 along alignment distance 54b at alignment position 52. Throughout alignment distance 54b, drive profile 46 is positioned over ball 42b but not over follower profile 28. As follower 22b moves through alignment distance 54b, follower profile 28 becomes rotationally aligned with drive profile 46 (if it is not already aligned).

[0057] In the aligned position 52, when the driven profile 28 is not aligned with the drive profile 46, the balls 42b are forced radially inward by the drive side 48. In this manner, the alignment feature 36b effects relative rotation between the driver portion 20b and the driven portion 22b about the axis of rotation 24 from the misaligned state 56 toward the aligned state 60.

[0058] 13 schematically illustrates a cross-sectional side view of coupling mechanism 18b in coupled position 62. Driver portion 20b is now rotationally aligned with driven portion 22b, and drive profile 46 mates with driven profile 28 for torque transmission between driver portion 20b and driven portion 22b.

[0059] While the present disclosure has been described with reference to exemplary embodiments, it will be understood that the present invention is not limited to the above-described embodiments. For example, it will be understood that the dimensions of parts may vary as needed. Accordingly, it is intended that the present invention be limited only by the scope of the appended claims. [Explanation of symbols]

[0060] 18a, 18b Coupling mechanism 20a, 20b Drive unit 22a, 22b Driven part 24 Rotation Axis 28 Follower Profile 36a, 36b Alignment mechanism 46 driving profiles 56 Misaligned 60 Alignment 62 Bond position

Claims

1. A coupling mechanism (18a, 18b) for a tool (10), comprising: a drive section (20a, 20b) rotatable about a rotation axis (24), the drive section (20a, 20b) including a drive profile (46); a follower (22a, 22b) rotatable about said axis of rotation (24), said follower (22a, 22b) including a follower profile (28) complementary to said drive profile (46), said follower profile (28) positioned to mate with said drive profile (46) at a coupling location (62) for torque transmission between said drive portion (20a, 20b) and said follower (22a, 22b); an alignment mechanism (36a, 36b) arranged to effect relative rotation between the driver (20a, 20b) and the follower (22a, 22b) about the rotation axis (24) from a misaligned state (56) of the coupling mechanism (18a, 18b), in which the drive profile (46) is rotationally misaligned with the follower profile (28), to an aligned state (60) of the coupling mechanism (18a, 18b), in which the drive profile (46) is rotationally aligned with the follower profile (28); a coupling mechanism (18a, 18b) comprising:

2. The coupling mechanism (18a, 18b) of claim 1, wherein the alignment mechanism (36a, 36b) is provided on the driver (20a, 20b) or the driven part (22a, 22b).

3. 3. The coupling mechanism (18a, 18b) of claim 1, wherein the follower (22a, 22b) is movable relative to the drive portion (20a, 20b) along the axis of rotation (24) from a decoupled position (26) in which the follower (22a, 22b) is decoupled from the drive portion (20a, 20b), to an intermediate aligned position (52) in which the drive profile (46) or the follower profile (28) is aligned with the alignment mechanism (36a, 36b) along the axis of rotation (24), and to the coupled position (62) in which the follower profile (28) is mated with the drive profile (46).

4. 4. The coupling mechanism (18a, 18b) of claim 3, wherein the alignment mechanism (36a, 36b) is arranged to provide relative rotation between the driver portion (20a, 20b) and the driven portion (22a, 22b) in the aligned position (52).

5. The coupling mechanism (18a, 18b) of any one of claims 1 to 4, wherein the alignment mechanism (36a, 36b) comprises a spring (40a, 40b).

6. 6. A coupling mechanism (18a, 18b) according to any one of claims 1 to 5, wherein the alignment mechanism (36a, 36b) comprises one or more protruding elements (42a, 42b), each of which is arranged to apply a torque to the driving profile (46) or the driven profile (28) in the non-aligned state (56).

7. 7. The coupling mechanism (18a, 18b) of claims 5 and 6, wherein the spring (40a, 40b) comprises the one or more protruding elements (42a, 42b), each protruding element (42a, 42b) being arranged to apply a force radially to the rotation axis (24).

8. 8. The coupling mechanism (18a, 18b) of claim 6 or 7, wherein each said protruding element (42a, 42b) includes a rounded shape for contacting said driving profile (46) or said driven profile (28).

9. The coupling mechanism (18a, 18b) according to any one of claims 6 to 8, wherein the coupling mechanism (18a, 18b) comprises a plurality of protruding elements (42a, 42b).

10. 10. A coupling mechanism (18a, 18b) according to any one of claims 9 to 9, wherein the protruding elements (42a, 42b) lie in a common plane transverse to the axis of rotation (24).

11. 11. A coupling mechanism (18a, 18b) according to claim 9 or 10, wherein the protruding elements (42a, 42b) are substantially evenly distributed around the axis of rotation (24).

12. A coupling mechanism (18a, 18b) according to any preceding claim, wherein the driving profile (46) and the driven profile (28) each have a polygonal shape.

13. 13. The coupling mechanism (18a, 18b) according to claim 11 and 12, wherein the angular distance between two adjacent protruding elements (42a, 42b) relative to the axis of rotation (24) corresponds to the angular distance between two edges (32, 50) of the polygonal shape relative to the axis of rotation (24).

14. 14. The coupling mechanism (18a) of claim 13, wherein the alignment mechanism (36a) is provided on the drive portion (20a), and each of the protruding elements (42a) is rotationally aligned with a unique side (48) of the polygonal shape of the drive profile (46) with respect to the rotation axis (24).

15. 14. The coupling mechanism (18b) of claim 13, wherein the alignment mechanism (36b) is provided on the follower (22b), and each of the protruding elements (42b) is rotationally aligned with a unique side (32) of the polygonal shape of the follower profile (28) relative to the axis of rotation (24).

16. A tool (10) comprising a coupling mechanism (18a, 18b) according to any one of claims 1 to 15.

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