EP3597370A1 - Handle and handheld machine tool - Google Patents

Abstract

The handle according to the invention for a handheld power tool comprises a handle portion that can be gripped by a user, a fastening portion, by means of which the handle can be attached to the handheld power tool, and a vibration decoupling device that is set up to decouple vibrations acting on the fastening portion from the handle portion , wherein the vibration decoupling device has a spring element with an adjustable spring stiffness.

Description

FIELD OF THE INVENTION

The present invention relates to a handle for a handheld power tool and a handheld power tool with such a handle.

A handheld power tool, such as a drilling machine, may include a main handle located on the rear of the handheld power tool and a side handle located on the front of the handheld power tool. The side handle is usually detachably attached to the hand machine tool. In order to prevent or at least reduce the transmission of oscillations or vibrations from the handheld power tool to the side handle, foams or elastomers can be used as springs. Such a spring is usually designed for only one frequency to be isolated.

If the frequency changes when using the handheld power tool due to the application, the setting of the handheld power tool or the working frequency, these springs cannot be adapted to the different applications. This means that these systems have only one area of application, which is optimally coordinated with regard to vibration isolation. If different frequencies occur in different areas of application, the insulation system no longer functions optimally. The insulation performance decreases because the excitation frequency no longer matches the stiffness of the spring used. One and the same insulation system can therefore often only be used for one type of handheld power tool and only achieves its optimum performance in a specific area of application. This means that the potential for good vibration isolation is often not fully exploited.

An object of the present invention is to provide an improved handle for a hand machine tool.

DISCLOSURE OF THE INVENTION

Accordingly, a handle for a hand machine tool is proposed. The handle comprises a handle section which can be gripped by a user, a fastening section with the aid of which the handle can be fastened to the handheld power tool, and a vibration decoupling device which is set up to decouple vibrations acting on the fastening section from the handle section, the vibration decoupling device has a spring element with an adjustable spring stiffness.

Because the spring stiffness of the spring element is adjustable, the vibration decoupling device can be used for a wide variety of applications in a wide variety of handheld power tools. This significantly increases the area of application for the handle. Furthermore, there is no need to provide different handles with a wide variety of vibration decoupling suitability.

In the present case, “spring stiffness” is to be understood as the ratio of a force acting on the spring element to the deflection of the spring element caused thereby. The "deflection" can be a compression or expansion of the spring element. The spring stiffness can also be referred to as the spring constant, spring hardness or spring rate. In addition to the fact that the vibration decoupling device is set up to "decouple" the vibrations from the handle section, it should be provided that the vibration decoupling device is set up to prevent or at least reduce the transmission of vibrations or vibrations from the fastening section to the handle section. In particular, the vibration decoupling device is set up to reduce a vibration amplitude. The handle is in particular a side handle of the hand tool or can be referred to as such.

According to one embodiment, the vibration decoupling device is arranged at least in sections within a handle element of the handle.

The grip element is preferably tubular. The fact that the vibration decoupling device is accommodated in the handle element enables a particularly compact structure of the handle to be achieved. Furthermore, the vibration decoupling device is protected from damage. The grip element can be made at least in sections from an elastically deformable material, such as, for example, an elastic plastic material, rubber or cork. This increases ease of use. The handle element is gripped by the user during operation of the hand-held power tool.

According to a further embodiment, the spring element is made from an elastomer, in particular from a rubber material, a thermoplastic elastomer or a silicone material.

The spring element can also be referred to as an elastomer spring element, elastomer spring or elastomer element. The spring element can be made from any other elastic deformable material. The spring element can be made from a foamed material. This means that the spring element can have pores. The material can be open-pore or closed-pore. The material can be a foam. Alternatively, the spring element can also be solid. The spring element can also comprise a metallic material. For example, the spring element can be a wire mesh, an adjustable leaf spring or the like.

According to a further embodiment, the spring stiffness of the spring element is infinitely adjustable.

This means that the spring stiffness is not only adjustable in a few steps, but can be continuously adjustable between a maximum possible spring stiffness and a minimum possible spring stiffness in a variety of spring stiffnesses. The adjustability of the spring stiffness is reversible. This means that the spring stiffness of the spring element can be increased and then reduced again and accordingly increased again.

According to a further embodiment, the spring element is tubular.

The spring element preferably has a hollow cylindrical geometry with an annular base surface.

According to a further embodiment, the vibration decoupling device has a connecting element which is accommodated at least in sections in the spring element and which connects the fastening section to the handle section.

The connecting element is preferably integrally connected to the spring element. In the case of integral connections, the connection partners are represented by atomic or molecular forces held together. Integral connections are non-detachable connections that can only be separated by destroying the connection means and / or connection partner. Cohesive can be connected, for example, by gluing or vulcanizing. For example, the spring element is vulcanized onto or glued to the connecting element. The connecting element can have a cylindrical base body which is received in the spring element. A threaded bolt can protrude from the top of the cylindrical base section and is screwed to the fastening section with the aid of a fastening element, for example a hexagon nut.

According to a further embodiment, the vibration decoupling device has a spring element holder which is arranged within the handle section and in which the spring element is received.

The spring element holder is preferably tubular or sleeve-shaped. The spring element holder is received in the grip element of the grip section and firmly connected to it. For example, a toothing can be provided between the spring element holder and the grip element. Furthermore, the spring element holder can also be glued to the handle element.

According to a further embodiment, the spring element connects the connecting element to the spring element holder, in particular in a material connection.

For example, the spring element is glued to the connecting element and the spring element holder or vulcanized onto them. The spring element is thus arranged between the spring element holder and the connecting element, the connecting element being arranged in particular in the spring element and the spring element being arranged in particular in the spring element holder. This results in a layered structure. This enables a particularly compact construction to be achieved.

According to a further embodiment, the vibration decoupling device has an adjusting element for adjusting the spring stiffness of the spring element.

The spring element is linearly displaceable along a longitudinal direction of the spring element to adjust the spring stiffness of the spring element. The longitudinal direction can coincide with an axis of symmetry of the handle section or can be oriented parallel to this.

According to a further embodiment, the spring element has a receiving region which extends in a longitudinal direction of the spring element and in which the adjusting element is received at least in sections.

As mentioned above, the setting element for setting the spring stiffness can be moved linearly in the receiving area. The further the setting element is pushed into the receiving area, the greater the spring stiffness, and the further the setting element is pulled out of the receiving area, the lower the spring stiffness. The receiving region can be a bore extending along the longitudinal direction or an opening extending along the longitudinal direction.

According to a further embodiment, the spring stiffness of the spring element can be increased by moving the adjusting element along the longitudinal direction into the receiving area, the spring stiffness of the spring element being able to be reduced by moving the adjusting element along the longitudinal direction out of the receiving area.

The shifting in and out can - as mentioned above - take place continuously, so that the spring stiffness of the spring element is continuously adjustable.

According to a further embodiment, the handle comprises a multiplicity of receiving regions and a multiplicity of adjusting elements which are arranged distributed uniformly apart from one another around a circumference of the spring element.

Alternatively, the receiving areas and the setting elements can also be arranged such that they are spaced unevenly apart from one another around the circumference of the spring element. The setting elements and the receiving areas can all have an identical geometry or different geometries. A setting element and vice versa is assigned to each recording area.

According to a further embodiment, the setting element is rod-shaped and has a circular, oval or polygonal, in particular rectangular, triangular or square cross section.

The geometry of the setting element is arbitrary. Each setting element can have an actuation area. The actuation area can, for example, be a bent end section of the actuation element. The actuation area can be actuated manually, for example.

According to a further embodiment, the spring stiffness of the spring element is adjusted manually, mechanically or mechatronically.

This means that the user can manually adjust the spring stiffness of the spring element by moving the setting elements. Furthermore, the setting elements can also be controlled mechanically in such a way that when a predetermined oscillation amplitude is exceeded, the setting elements are mechanically displaced in order to adapt the spring stiffness. In the case of a mechatronic drive, an optimal spring stiffness of the spring element can be set on the basis of measured vibrations with the aid of an adjusting element which shifts the adjusting elements. The adjusting elements are preferably rod-shaped and are made of a material that makes it possible to pull the adjusting elements out of the spring element and insert them into the latter. For example, steel wires or plastic fittings can be used as setting elements.

A handheld power tool with such a handle is also proposed.

The handheld power tool can be, for example, a hammer drill, a chisel hammer, a core drill, a saw, a grinder, a screwdriver, a bolt feed tool or the like. The handheld power tool preferably has a housing with a main handle and the previously explained handle. The handle is preferably laterally connected to the housing. The handle can therefore also be called a side handle. The handle is detachably connected to a cylindrical fastening section of the housing. The handle can be pushed onto the fastening section of the housing and then fixed to the fastening section by twisting the grip section. Conversely, the handle can also be released from the hand-held power tool by relaxing the fastening section.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1

eine schematische Ansicht einer Ausführungsform einer Handwerkzeugmaschine;

Fig. 2

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

Fig. 3

eine vergrößerte schematische Schnittansicht des Handgriffs gemäß der Schnittlinie III-III der Fig. 2.

The following description explains the invention using exemplary embodiments and figures. The figures show:

Fig. 1

a schematic view of an embodiment of a hand tool;

Fig. 2

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

Fig. 3

an enlarged schematic sectional view of the handle according to section line III-III of Fig. 2 ,

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

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 grinder, a screwdriver, a bolt feed 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 cable can also be provided on the housing 2, which can be connected to a socket. Furthermore, the housing 2 comprises a main handle, not shown, which in the orientation of FIG 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 machine tool 1. The fastening device 3 is in the orientation of the 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 from the left to the right onto the fastening section 4 and pulled from the fastening section 4 from the right to the 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 gripped by a user to operate the handheld power tool 1, and a preferably annular 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 tightening strap 8. The tightening strap 8 can be a steel strap, for example. Furthermore, the fastening section 7 comprises a support element 9. The tensioning band 8 and the support element 9 form a circular receiving area 10 for the fastening section 4 of the housing 2 of the handheld power tool 1. Furthermore, the fastening section 7 comprises a base element 11, a tensioning element 12 and one in the tensioning element 12 Fastening element 13 received. The fastening element 13 can be, for example, a hexagon nut. The support element 9, the tensioning element 12 and the fastening element 13 are accommodated in the base element 11 at least in sections.

The fastening element 13 is screwed to a connecting element 14 assigned to the handle section 6. For this purpose, the connecting element 14 has a threaded bolt 14A, which is guided through the base element 11, the tensioning band 8, the tensioning element 12 and the fastening element 13. By turning the grip section 6 relative to the fastening section 7, the fastening element 13 can thus be tightened for tensioning the tensioning strap 8 and loosened for releasing the tensioning strap 8. As a result, the fastening section 7 can be detachably connected to the fastening section 4 of the handheld power tool 1. The connecting element 14 further comprises a base body 14B, from which the threaded bolt 14A extends at the end.

The grip section 6 comprises a grip element 15. The grip element 15 is preferably constructed rotationally symmetrically to an axis of symmetry M6 of the grip section 6. The grip element 15 can be made at least in sections from an elastically deformable material. When the handheld power tool 1 is in operation, the handle element 15 is gripped at least in sections by a hand of the user. The grip element 15 can be tubular. The connecting element 14, in particular the base body 14B of the connecting element 14, is at least in sections in the grip element 15 added. A disc 16 can be arranged between the grip element 15 and the base element 11. The washer 16 is, for example, a washer.

A vibration decoupling device 17 of the handle 5 is accommodated in the handle element 15. The vibration decoupling device 17 comprises a sleeve-shaped or tubular spring element holder 18 which is received in the handle element 15 and which faces the fastening section 7. The spring element holder 18 can be a plastic component, for example. The spring element holder 18 is non-rotatably connected to the handle element 15. Received in the spring element holder 18 is the connection element 14, which is also assigned to the vibration decoupling device 17, in particular the base body 14B thereof.

The vibration decoupling device 17 further comprises a spring element 19, the spring stiffness of which is adjustable, and a plurality of adjusting elements 20, 21, by means of which the spring stiffness of the spring element 19 can be set. A longitudinal direction L19 is assigned to the spring element 19. The longitudinal direction L19 runs parallel to the axis of symmetry M6. The longitudinal direction L19 can coincide with the axis of symmetry M6. The longitudinal direction L19 can be in the orientation of the Fig. 2 be oriented from bottom to top or from top to bottom. The setting elements 20, 21 can be designed, for example, as steel wires or plastic bodies. An actuating area 22, 23 is assigned to each setting element 20, 21. The actuation areas 22, 23 can be formed in that the respective adjusting element 20, 21 is bent or bent at the end by 90 °.

The Fig. 3 shows the vibration decoupling device 17 in a sectional view along the section line III-III of FIG Fig. 2 , As the Fig. 3 shows, the spring element holder 18 is rotatably connected to the handle element 15 by means of a toothing 24. In addition, a connection with the aid of feather keys 25 can also be provided. Furthermore, the spring element holder 18 can also be glued to the handle element 15. Received in the spring element holder 18 is the sleeve-shaped or tubular spring element 19. The spring element 19 is made of an elastomer, such as rubber, a thermoplastic polyurethane, a silicone material or the like.

The spring element 19 is an elastomer spring element or can be referred to as such. The spring element 19 has a hollow cylindrical geometry with an annular base. The geometry of the spring element 19 extends along the axis of symmetry M6 in the longitudinal direction L19. The spring element 19 is there rotationally symmetrical to the axis of symmetry M6. The spring element 19 can, for example, be glued to the spring element holder 18 or vulcanized to it. That is, the spring element 19 can be integrally connected to the spring element holder 18. In the case of integral connections, the connection partners are held together by atomic or molecular forces. Integral connections are non-detachable connections that can only be separated by destroying the connecting means.

As the Fig. 3 further shows, the connecting element 14 or the base body 14B of the same is accommodated in the spring element 19. The connecting element 14 can in turn be glued to the spring element 19 or this can be vulcanized onto the connecting element 14. The spring element 19 comprises a plurality of receiving regions 26, 27 which extend in the longitudinal direction L19 and in which the adjusting elements 20, 21 are received. The receiving areas 26, 27 can be designed as bores extending in the longitudinal direction L19. The receiving areas 26, 27 can break through the entire spring element 19 over its entire length. The receiving areas 26, 27 can, as in the Fig. 3 shown to be formed as circular bores.

Alternatively, however, the receiving areas 26, 27 can have any other desired geometry. For example, the receiving areas 26, 27 can be polygonal, in particular triangular, square or rectangular. A plurality of such receiving areas 26, 27 are preferably provided, which are arranged evenly distributed around a circumference of the spring element 19. For example, ten such receiving areas 26, 27 and, accordingly, ten such adjusting elements 20, 21 are provided. The spring stiffness of the spring element 19 can be adjusted with the aid of the setting elements 20, 21. In the present case, the spring stiffness is to be understood as the ratio of a force acting on the spring element 19 to the deflection of the spring element 19 caused thereby.

The spring stiffness, spring constant, spring hardness or spring rate of the spring element 19 is adjusted in that the setting elements 20, 21 are pushed into or pulled out of the spring element 19. When the adjusting elements 20, 21 are pushed into the spring element 19, its spring stiffness is increased. When the setting elements 20, 21 are pulled out of the spring element 19, its spring stiffness is reduced. This process is reversible. The setting elements 20, 21 can be moved synchronously or asynchronously.

The functionality of the vibration decoupling device 17 is explained below. Vibrations of different frequencies can occur in different applications of handheld power tool 1. It is desirable that these vibrations or vibrations are not transmitted or only dampened to the handle section 6 of the handle 5 in order to improve the comfort for the user. Due to the fact that the vibration decoupling device 17 can be controlled with the aid of the setting elements 20, 21, the spring stiffness of the spring element 19 can be changed so that the handheld power tool 1 can always work at an optimal operating point and thus a minimum of oscillations or vibrations at the all operating points Handle section 6 can be achieved. As a result, the handle 5 can be used for a wide variety of handheld power tools 1 in a wide variety of operating states.

The setting elements 20, 21 can be operated manually by the user. Furthermore, mechanical adjustment and / or mechatronic adjustment can also be carried out. With a mechatronic adjustment, the advantage can be achieved that an optimal spring stiffness of the spring element 19 can be set on the basis of measured oscillations or vibrations. An adjusting element for moving the adjusting elements 20, 21 can then be provided.

The setting elements 20, 21 are preferably made of a material that allows the setting elements 20, 21 to be simply inserted into and removed from the spring element 19 without the risk of kinking, and thereby the receiving regions 26, 27 provided in the spring element 19 fill up or release. The setting elements 20, 21 can, for example, be steel wires or molded pieces made of plastic. The setting elements 20, 21 can be round. However, the setting elements 20, 21 can also have any geometry. For example, the setting elements 20, 21 can have a polygonal or oval cross section.

REFERENCES USED

1

Hand tool

2

casing

3

fastening device

4

attachment section

5

handle

6

handle portion

7

attachment section

8th

strap

9

support element

10

reception area

11

base element

12

clamping element

13

fastener

14

connecting element

14A

threaded bolt

14B

base body

15

handle element

16

Write

17

Vibration decoupling device

18

Spring element holder

19

spring element

20

adjustment

21

adjustment

22

operating range

23

operating range

24

gearing

25

Adjusting spring

26

reception area

27

reception area

L19

longitudinal direction

M6

axis of symmetry

Claims (15)

Handle (5) for a hand machine tool (1), with a handle section (6) that can be gripped by a user, a fastening section (7), by means of which the handle (5) can be fastened to the hand machine tool (1), and one Vibration decoupling device (17) which is set up to decouple vibrations acting on the fastening section (7) from the handle section (6), the vibration decoupling device (17) having a spring element (19) with an adjustable spring stiffness. Handle according to claim 1, characterized in that the vibration decoupling device (17) is arranged at least in sections within a handle element (15) of the handle (5). Handle according to claim 1 or 2, characterized in that the spring element (19) is made of an elastomer, in particular of a rubber material, a thermoplastic elastomer or a silicone material. Handle according to one of claims 1-3, characterized in that the spring stiffness of the spring element (19) is infinitely adjustable. Handle according to one of claims 1-4, characterized in that the spring element (19) is tubular. Handle according to claim 5, characterized in that the vibration decoupling device (17) has a connecting element (14) which is received at least in sections in the spring element (19) and which connects the fastening section (7) to the handle section (6). Handle according to claim 6, characterized in that the vibration decoupling device (17) has a spring element holder (18) which is arranged within the handle section (6) and in which the spring element (19) is received. Handle according to claim 7, characterized in that the spring element (19) connects the connecting element (14) to the spring element holder (18), in particular cohesively. Handle according to one of claims 1-8, characterized in that the vibration decoupling device (17) has an adjusting element (20, 21) for adjusting the spring stiffness of the spring element (19). Handle according to claim 9, characterized in that the spring element (19) has a receiving region (26, 27) which extends in a longitudinal direction (L19) of the spring element (19) and in which the adjusting element (20, 21) is received at least in sections. Handle according to claim 10, characterized in that the spring stiffness of the spring element (19) can be increased in that the adjusting element (20, 21) is moved along the longitudinal direction (L19) into the receiving area (26, 27), and that the spring stiffness of the The spring element (19) can be reduced in size in that the adjusting element (20, 21) is moved out of the receiving area (26, 27) along the longitudinal direction (L19). Handle according to claim 10 or 11, characterized by a multiplicity of receiving areas (26, 27) and a multiplicity of adjusting elements (20, 21) which are arranged distributed uniformly apart from one another around a circumference of the spring element (19). Handle according to one of claims 9-12, characterized in that the adjusting element (20, 21) is rod-shaped and has a circular, oval or polygonal, in particular rectangular, triangular or square, cross section. Handle according to one of claims 1-13, characterized in that the spring stiffness of the spring element (19) is adjusted manually, mechanically or mechatronically. Hand tool (1) with a handle (5) according to any one of claims 1-14.

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