EP3608064B1 - Handle and handheld machine tool - Google Patents

Description

FIELD OF THE INVENTION

The present invention relates to a handle for a handheld power tool, with a handle section that can be grasped by a user, a fastening section with the help of which the handle can be fastened to the handheld power tool, and an overload protection device which, when a torque acting on the fastening section, causes a Exceeds a predetermined limit value, releases the handle portion in such a way that the handle portion pivots relative to the fastening portion.

From the DE 10 2007 047083 A1 as well as from the DE 101 30 548 A1 additional handles are known. In the DE 10 2008 00041 A1 a handle for an electric hand tool is described. The EP 2 241 408 A1 discloses a side handle for a handheld power tool. Another handle is from the JP2004 2494 30 A known.

A handheld power tool, such as a drilling machine, for example, can comprise a main handle, which is arranged on the rear of the handheld power tool, and a side handle, which is arranged on the front of the handheld power tool. The side handle is usually releasably attached to the handheld power tool. In order to prevent an increased torque from suddenly being transmitted to the side handle when a tool driven by the handheld power tool is blocked, such a handheld power tool can comprise a slip clutch integrated in a drive system of the same.

It is an object of the present invention to provide an improved handle for a handheld power tool.

DISCLOSURE OF THE INVENTION

Accordingly, a handle for a handheld power tool is proposed. The handle comprises a handle section that can be grasped by a user, a fastening section with the aid of which the handle can be fastened to the handheld power tool, and an overload protection device which, when a Fastening portion acting torque exceeds a predetermined limit value, releases the handle portion in such a way that the handle portion pivots relative to the fastening portion.

Because the overload protection device releases the grip section when the predetermined limit value of the torque is exceeded, the torque acting on the fastening section can be prevented from suddenly acting on the user's hand. As a result, a separate slip clutch in the handheld power tool itself can be dispensed with. As a result, the hand-held power tool can be constructed in a simpler and more cost-effective manner.

The fact that the handle section "pivots" relative to the fastening section is to be understood in particular as meaning that the handle section rotates with respect to the fastening section. The predetermined or predetermined limit value is defined in particular by the structural design of the overload protection device. The handle is in particular a side handle of the handheld power tool or can be referred to as such. The overload protection device can in particular be any device which is suitable for releasing the handle section as soon as the predetermined limit value is exceeded. For this purpose, the overload protection device can comprise, for example, an optional spring element, such as a cylinder spring element or an elastomer spring element, a slip clutch, a friction element or the like. In particular, the overload protection device is not integrated into the handheld power tool, but rather into the handle.

According to one embodiment, the handle section is rotatably mounted on the fastening section with the aid of an axis of rotation.

The axis of rotation can be rotatably mounted relative to the handle section and non-rotatably on the fastening section or vice versa. The axis of rotation can for example be a bolt or the like.

When the torque acting on the fastening section exceeds the predetermined limit value, the overload protection device releases the handle section in such a way that the handle section is by 30 ° to 70 °, preferably by 40 ° to 60 °, more preferably by 45 ° to 55 °, relative to the fastening section °, more preferably by 50 °, pivoted.

The aforementioned angle can be referred to as the pivot angle. The pivot angle is defined as an angle between an axis of symmetry of the handle section and an axis of symmetry of the fastening section. The pivot angle is preferably 50 °. The pivot angle can also be 50 ° ± 5 °, preferably 50 ° ± 4 °, more preferably 50 ° ± 3 °, more preferably 50 ° ± 2 °, more preferably 50 ° ± 1 °, more preferably exactly 50 °. The handle section can preferably be pivoted in two directions by 50 ° in relation to the fastening section. That is to say, a total pivoting range of the handle section can be 100 °. The handle section can be pivoted clockwise or counterclockwise relative to the fastening section, depending on the direction of rotation of a chuck or drill chuck of the handheld power tool.

According to a further embodiment, the handle is from a non-pivoted state in which an axis of symmetry of the handle section and an axis of symmetry of the fastening section are arranged parallel to one another, to a pivoted state in which the axis of symmetry of the handle section and the axis of symmetry of the fastening section are arranged obliquely to one another, and reversely pivotable.

In the pivoted state, the axis of symmetry of the handle section and the axis of symmetry of the fastening section are arranged obliquely relative to one another at the aforementioned pivot angle. In the non-pivoted state, the axes of symmetry are in particular arranged coaxially to one another. That is, in the non-pivoted state, the axis of symmetry of the handle section coincides with the axis of symmetry of the fastening section.

According to a further embodiment, the overload protection device has a spring element which can be brought from an uncompressed state into a compressed state when the handle section is pivoted relative to the fastening section.

The spring element is preferably a cylinder spring. In particular, the spring element is a compression spring. The predetermined or predetermined limit value can be defined by a corresponding selection of a geometry of the spring element and / or a selection of its material. Alternatively, the spring element can also be made of an elastomer. The spring element can therefore also be an elastomer spring element or be referred to as such. For example, the spring element can be a plastic body or a rubber body. The spring element preferably biases the handle Direction of the unswiveled state. That is, as soon as the torque acting on the fastening section falls below the limit value again, the overload protection device and in particular the spring element automatically move the handle from the pivoted state to the non-pivoted state.

According to a further embodiment, the overload protection device has a housing element in which the spring element is received.

The housing element preferably comprises a tubular sleeve area in which the spring element is received, as well as a connection area formed in one piece with the sleeve area.

According to a further embodiment, the handle section is rotatably mounted on the housing element.

The grip section is preferably rotatably mounted on the aforementioned connection area of the housing element. The previously mentioned axis of rotation is mounted on the connecting area. The spring element is preferably received in the housing element in such a way that the spring element does not contact the sleeve area. This avoids friction between the spring element and the sleeve area.

According to a further embodiment, the overload protection device has a displacement element which is mounted displaceably in the housing element.

The displacement element is preferably guided linearly in the sleeve area of the housing element. In particular, the displacement element is guided linearly along the axis of symmetry of the handle section.

According to a further embodiment, the displacement element is spring-preloaded in the direction of the fastening section with the aid of the spring element.

The spring element is preferably spring-pretensioned in the direction of the fastening section both in the non-pivoted state and in the pivoted state of the handle. In this case, however, the spring preload is greater in the pivoted state than in the non-pivoted state. As a result, the handle can then when the torque acting on the fastening section reaches the predetermined limit value again falls below, are automatically brought back from the pivoted state to the non-pivoted state.

According to a further embodiment, the overload protection device has a guide element received in the spring element, on which the displacement element is linearly guided.

The guide element is in particular received centrally in the housing element and in particular centrally in the sleeve area of the housing element. The displacement element preferably comprises a cylindrical recess, with the aid of which the displacement element is linearly guided on the guide element. The guide element can have a circumferential guide shoulder which is received in the recess of the displacement element. That is, the displacement element is guided on the outside on the sleeve area of the housing element and on the inside on the guide element. Tilting of the displacement element can hereby reliably be prevented. This increases the operational reliability of the overload protection device.

According to a further embodiment, the overload protection device has a pivoting element which is connected to the fastening section and rests against an end face of the displacement element.

The end face is preferably flat or flat. The pivoting element is preferably rotatably mounted on the handle section, in particular on the housing element, preferably on the connecting area of the housing element, with the aid of the aforementioned axis of rotation.

According to a further embodiment, the pivoting element has a cylindrical first contact surface and a cylindrical second contact surface for contacting the end face of the displacement element.

The first contact surface and the second contact surface are preferably each semicylindrical. When the handle is pivoted from the unswiveled state into the pivoted state, one of the two contact surfaces in each case slides and / or rolls on the end face of the displacement element. In the non-pivoted state of the handle, both contact surfaces of the pivoting element are in contact with the end face of the displacement element, and in the pivoted state only one of the two contact surfaces is in contact with the end face.

The cylindrical or semi-cylindrical geometry of the contact surfaces enables the handle section to be pivoted smoothly relative to the fastening section.

According to a further embodiment, the spring element is received at least in sections in the displacement element.

The displacement element preferably has an in particular cylindrical receiving pocket for receiving the spring element. The displacement element is received at least in sections in the sleeve area of the housing element. Because the spring element is received in the receiving pocket of the displacement element, contact of the spring element with the sleeve area is prevented. This avoids frictional contact between the spring element and the sleeve area. The spring element is also received at least in sections in a connecting element. The connecting element is also received at least in sections in the sleeve area. The spring element is thus received between the connecting element and the sliding element. The connecting element is fixed linearly with respect to the sleeve area. For example, the connecting element is screwed to the sleeve area.

According to a further embodiment, the overload protection device is arranged between the fastening section and a grip element of the grip section.

The grip element is preferably made at least in sections from an elastically deformable material, such as an elastic plastic material, rubber or cork. The grip element can be pushed or pulled onto a tubular or rod-shaped base element. The base element is firmly connected to the overload protection device, in particular to the housing element of the overload protection device, with the aid of the aforementioned connecting element.

A handheld power tool with a handle of this type is also proposed.

The hand machine tool is, for example, a hammer drill, a chisel hammer, a core drill, a saw, a grinding machine, a screwdriver, a bolt pusher tool or the like. The handheld power tool comprises a main handle and the previously explained handle, which is preferably arranged on the side of the handheld power tool. The handle can therefore also be referred to as a side handle or is a side handle of the hand machine tool. The handle is in particular releasably connected to the handheld power tool.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1

eine schematische Ansicht einer Ausführungsform einer Handwerkzeugmaschine; und

Fig. 2

eine schematische Schnittansicht einer Ausführungsform eines Handgriffs für die Handwerkzeugmaschine gemäß der Schnittlinie II-II der Fig. 1.

The following description explains the invention on the basis of exemplary embodiments and figures. In the figures shows:

Fig. 1

a schematic view of an embodiment of a handheld power tool; and

Fig. 2

a schematic sectional view of an embodiment of a handle for the hand power tool according to the section line II-II of FIG Fig. 1 .

Identical or functionally identical elements are indicated by the same reference symbols in the figures, unless otherwise stated.

EMBODIMENTS OF THE INVENTION

Fig. 1 shows a schematic view of an embodiment of a handheld power tool 1. The handheld power tool 1 can be, for example, a hammer drill, a chisel hammer, a core drill, a saw, a grinding machine, a screwdriver, a bolt pusher tool or the like.

The handheld power tool 1 comprises a housing 2, to which, for example, an accumulator (not shown) is attached. Alternatively, a power cord can be provided on the housing 2, which can be connected to a socket. Furthermore, the housing 2 comprises a main handle, not shown, which is in the orientation of the Fig. 1 is arranged on the right. Furthermore, a fastening device 3 is provided for fastening a tool, in particular a cutting tool, such as a drill, to the hand-held power tool 1. The fastening device 3 is in the orientation of Fig. 1 arranged on the left. The fastening device 3 is, for example, a chuck or drill chuck. The housing 2 comprises a fastening section 4. The fastening section 4 is preferably cylindrical in cross section, in particular circular cylindrical.

A handle 5 is detachably fastened to the fastening section 4. "Detachable" here means that the handle 5 can be separated from the fastening section 4 and connected to it again. The handle 5 can also be rotatably attached to the fastening section 4. For example, the handle 5 in the orientation of the Fig. 1 pushed onto the fastening section 4 from left to right and pulled off the fastening section 4 from right to left. The handle 5 is in particular a so-called side handle or can be referred to as a side handle. The handle 5 comprises a handle section 6 which can be grasped by a user in order to operate the handheld power tool 1, as well as a preferably ring-shaped fastening section 7 which can be detachably connected to the fastening section 4 of the housing 2.

As the Fig. 2 shows, the fastening section 7 comprises a ring element 8, in which the fastening section 4 of the handheld power tool 1 is received in the assembled state of the handle 5. In addition to the ring element 8, the fastening section 7 comprises a base element 9 and a clamping band 10 connecting the ring element 8 and the base element 9. Furthermore, the fastening section 7 comprises a clamping element 11 and a fastening element 12 received in the clamping element 11. The fastening element 12 is, for example, a cylinder screw. In particular, the fastening element 12 can be a hexagon socket screw. With the aid of the fastening element 12, the fastening section 7 is connected to a pivoting element 13. The pivoting element 13 is preferably part of the fastening section 7. The fastening section 7 is assigned an axis of symmetry M7. In particular, the fastening section 7 is constructed mirror-symmetrically to a plane running through the axis of symmetry M7.

The fastening element 12 can be loosened or tightened with the aid of a rotation of the handle section 6 with respect to the fastening section 7 about the axis of symmetry M7. Accordingly, with the aid of the fastening element 12, the tensioning band 10 can be tensioned and relaxed. To fasten the handle 5 to the handheld power tool 1, the tensioning band 10 is tensioned, and to remove the handle 5 from the handheld power tool 1, the tensioning band 10 is relaxed again.

The handle section 6 comprises a handle element 14 which can be constructed in a tubular manner. The grip element 14 is preferably made at least partially from an elastically deformable material, such as, for example, an elastically deformable plastic or cork. To operate the handheld power tool 1, the handle element 14 is grasped by a user with his hand. The grip element 14 is pulled onto a base element 15 of the grip section 6. The base element 15 can be tubular. The base element 15 can for example be made of a metal material such as steel or aluminum.

The handle section 6 is preferably designed to be rotationally symmetrical to an axis of symmetry M6. The axis of symmetry M6 and the axis of symmetry M7 can, as in the Fig. 2 shown, be arranged parallel to each other and coaxially. “Coaxial” means that the axis of symmetry M6 coincides with the axis of symmetry M7.

An overload protection device 16 is provided between the base element 15 and the fastening section 7. The overload protection device 16 is part of the handle section 6. The overload protection device 16 comprises a housing element 17 which is tubular or sleeve-shaped. The housing element 17 comprises a tubular sleeve area 18 and a connection area 19, on which the pivoting element 13 of the fastening section 7 is rotatably mounted with the aid of a rotation axis 20. The axis of rotation 20 can, for example, be a bolt with a circular cross section.

By pivoting the handle section 6 about the axis of rotation 20 relative to the fastening section 7, the handle 5 can be moved from one to the other in the Fig. 2 The non-pivoted state shown, in which the axis of symmetry M6 of the handle section 6 and the axis of symmetry M7 of the fastening section 7 are arranged parallel and in particular coaxially to one another, in a pivoted state, not shown, in which the axis of symmetry M6 and the axis of symmetry M7 are arranged obliquely to one another, and vice versa be spent. The handle portion 6 can be in the orientation of the Fig. 2 be pivoted both to the left and to the right or clockwise or counterclockwise.

An, in particular cylindrical, connecting element 21 is provided between the housing element 17 and the base element 15 or the grip element 14. The connecting element 21 connects the base element 15 to the housing element 17. The connecting element 21 can be firmly screwed to the base element 15 with the aid of a screw (not shown). The sleeve area 18 of the housing element 17, in turn, can have a thread provided on the connecting element 21 be screwed to this. For this purpose, an external thread 22 can be provided on the connecting element 21 and a corresponding internal thread 23 can be provided on the sleeve region 18.

A spring element 24 is received in the sleeve area 18. The spring element 24 is preferably a cylinder spring. In particular, the spring element 24 is a compression spring. The spring element 24 can also be made of an elastomeric plastic. That is, the spring element 24 is not necessarily a cylinder spring, but can also be an elastomer spring element or can be referred to as such. The spring element 24 can be received in the connecting element 21 at least in sections. For this purpose, the connecting element 21 can have a cylindrical receiving pocket 25.

A guide element 26 is received in the spring element 24. The guide element 26 can be cylindrical and constructed rotationally symmetrical to the axis of symmetry M6. The guide element 26 can be firmly connected to the connecting element 21. For example, a screw can be passed from the base element 15 through the connecting element 21 into the guide element 26 and screwed to it. For this purpose, the guide element 26 can comprise a central threaded bore 27 into which the aforementioned screw is screwed. Facing away from the threaded bore 27, the guide element 26 comprises a circumferential guide shoulder 28. In the region of the guide shoulder 28, the guide element 26 has a reduced outer diameter. The spring element 24 preferably makes contact neither with the sleeve area 18 nor the guide element 26.

The overload protection device 16 further comprises a displacement element 29. The displacement element 29 is linearly guided along the axis of symmetry M6 both on the sleeve area 18 of the housing element 17 and on the guide shoulder 28 of the guide element 26. An outer surface of the sliding element 29 is linearly guided on the sleeve region 18, and an inner surface of a centrally arranged recess 30 of the sliding element 29 is guided on the guide shoulder 28. Because of the double guidance of the sliding element 29, tilting of the sliding element 29 can be reliably prevented.

The displacement element 29 furthermore comprises a planar or flat end face 31 as well as a receiving pocket 32 facing away from the end face 31, in which the spring element 24 is received at least in sections. Two cylindrical contact surfaces 33, 34 of the pivoting element 13 rest on the end face 31. The spring element 24 is thus arranged between the displacement element 29 and the connecting element 21 and thereby pretensions the displacement element 29 in the direction of the fastening section 7. That is, the spring element 24 presses the end face 31 against the two contact surfaces 33, 34. The contact surfaces 33, 34 are, as in FIG Fig. 2 shown, preferably semi-cylindrical.

The functionality of the handle 5 is explained below. When the handheld power tool 1 is in operation, the tool accommodated in the fastening device 3 may block. As a result, a torque DM acting on the fastening section 7 increases suddenly. The torque DM can, as in the Fig. 2 shown to be oriented counterclockwise. Alternatively, the torque DM can also be oriented clockwise. In order to prevent the torque DM from being transmitted directly and abruptly to the handle section 6 and thus to the user's hand, the overload protection device 16 is provided.

When the torque DM acting on the fastening section 7 exceeds a predetermined or predetermined limit value, the overload protection device 16 releases the handle section 6 in such a way that the handle section 6 pivots with respect to the fastening section 7. The limit value can be set by the geometry of the spring element 24 or by its choice of material. When the handle section 6 is pivoted relative to the fastening section 7, the spring element 24 is held in place by one of the Fig. 2 uncompressed state shown is brought into a compressed state not shown. The displacement element 29 is thereby moved in the direction of the grip element 14. That is to say, the displacement element 29 dips into the sleeve area 18 of the housing element 17. By providing the overload protection device 16, a complex and costly slip clutch in the handheld power tool 1 itself can advantageously be dispensed with.

REFERENCE LIST

1

Hand machine tool

2

casing

3

Fastening device

4th

Fastening section

5

Handle

6th

Handle section

7th

Fastening section

8th

Ring element

9

Base element

10

Tension band

11

Clamping element

12th

Fastener

13th

Pivoting element

14th

Handle element

15th

Base element

16

Overload protection device

17th

Housing element

18th

Sleeve area

19th

Connection area

20th

Axis of rotation

21

Connecting element

22nd

External thread

23

inner thread

24

Spring element

25th

Receiving pocket

26th

Guide element

27

Threaded hole

28

Leadership paragraph

29

Sliding element

30th

Recess

31

Face

32

Receiving pocket

33

Contact surface

34

Contact surface

DM

Torque

M6

Axis of symmetry

M7

Axis of symmetry

Claims (14)

1. Handle (5) for a hand-held power tool (1), with a handle portion (6) which can be gripped by a user, with a fastening portion (7) by means of which the handle (5) can be fastened to the hand-held power tool (1), and with an overload protection device (16) which, if a torque (DM) acting on the fastening portion (7) exceeds a predetermined limit value, frees the handle portion (6) in such a way that the handle portion (6) pivots relative to the fastening portion (7), characterized in that, if the torque (DM) acting on the fastening portion (7) exceeds the predetermined limit value, the overload protection device (16) frees the handle portion (6) in such a way that the handle portion (6) pivots with respect to the fastening portion (7) through 30° to 70°, preferably through 40° to 60°, more preferably through 45° to 55°, further preferably through 50°.
2. Handle according to Claim 1, characterized in that the handle portion (6) is mounted on the fastening portion (7) so as to be rotatable by means of an axis of rotation (20).
3. Handle according to either of Claims 1 and 2, characterized in that the handle (5) is pivotable from an unpivoted state, in which an axis of symmetry (M6) of the handle portion (6) and an axis of symmetry (M7) of the fastening portion (7) are arranged parallel to one another, into a pivoted state, in which the axis of symmetry (M6) of the handle portion (6) and the axis of symmetry (M7) of the fastening portion (7) are arranged obliquely to one another, and vice versa.
4. Handle according to one of Claims 1 to 3, characterized in that the overload protection device (16) has a spring element (24) which, with the handle portion (6) being pivoted relative to the fastening portion (7), can be brought from an uncompressed state into a compressed state.
5. Handle according to Claims 4, characterized in that the overload protection device (16) has a housing element (17) in which the spring element (24) is received.
6. Handle according to Claim 5, characterized in that the handle portion (6) is rotatably mounted on the housing element (17).
7. Handle according to Claim 6, characterized in that the overload protection device (16) has a displacement element (29) which is mounted so as to be displaceable in the housing element (17).
8. Handle according to Claim 7, characterized in that the displacement element (29) is spring-biased in the direction of the fastening portion (7) by means of the spring element (24).
9. Handle according to Claim 7 or 8, characterized in that the overload protection device (16) has a guide element (26) which is received in the spring element (24) and on which the displacement element (29) is linearly guided.
10. Handle according to one of Claims 7 to 9, characterized in that the overload protection device (16) has a pivoting element (13) which is connected to the fastening portion (7) and which bears against an end face (31) of the displacement element (29).
11. Handle according to Claim 10, characterized in that the pivoting element (13) has a cylindrical first bearing face (33) and a cylindrical second bearing face (34) for bearing against the end face (31) of the displacement element (29).
12. Handle according to one of Claims 7-11, characterized in that the spring element (24) has at least portions thereof received in the displacement element (29).
13. Handle according to one of Claims 1-12, characterized in that the overload protection device (16) is arranged between the fastening portion (7) and a handle element (14) of the handle portion (6).
14. Hand-held power tool (1) having a handle (5) according to one of Claims 1-13.

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