EP2750836A1

EP2750836A1 - Handle device

Info

Publication number: EP2750836A1
Application number: EP12790435.7A
Authority: EP
Inventors: Willy Braun
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2011-09-02
Filing date: 2012-08-31
Publication date: 2014-07-09
Anticipated expiration: 2032-08-31
Also published as: EP2750835A1; WO2013030381A1; WO2013030377A1; EP2750835B1; CN103764350A; CN103796800B; WO2013030382A1; CN103796800A; WO2013030380A1; EP2750834A1; EP2750834B1; CN103764350B; DE102011082093A1; EP2750837B1; EP2750837A1; EP2750836B1; CN103781597A

Abstract

The invention relates to a handle device for a hand-held power tool, which comprises an operating mode-switchover device and a drive device for driving an insert tool in different operating modes, with at least one spring element (18) and a handle unit (22) which is mounted on a machine housing (20) so as to be movable at least to a limited extent and which is at least partially decoupled in terms of vibrations via the at least one spring element (18) with respect to the machine housing (20). It is proposed that the handle device comprise at least one screwplate (48) which is provided in order to secure the spring element (18) in form- and force-locking manner.

Description

description

Handquiffvorrichtunq prior art

The invention relates to a handle device for a hand tool according to the preamble of the independent claims.

The entry into force of legal requirements, which limit the vibration behavior of hand-held power tools, has given rise to this in the industry

Topic an ever-increasing importance. Especially with heavy drilling and impact hammers due to the high single impact strength vibration is very pronounced. The standard or law now stipulates how long the user may work with it, depending on the vibration level of the machine. If the load from the vibration exceeds specified limits, the permissible service life per day is correspondingly reduced.

As a result, product development is increasingly working on vibration reduction measures. The primary goal is to further increase the ease of use and to maintain a practicable measure of the associated service life per day. In order to reduce vibrations in hammers, part of the machine movement is usually decoupled directly by means of handles for an operator. With regard to the type of decoupling, the market uses fundamentally different concepts. In addition to a double-shell housing, the most widely used method is a handle with an elastic connection to the hammer, in order to decouple the occurring vibrations from the operator via suspension and damping.

Antivibration handles with elastic connection to the hammer cause due to the required stiffness as a side effect and relative movements between the hammer and the handle itself. From this, requirements for the interface between a hammer and an anti-vibration handle can be derived:

□ In spite of its elastic connection for decoupling, the anti-vibration handle must continue to allow precise guidance of the power tool.

□ Connecting and guiding the anti-vibration handle should not affect the hammer's ergonomic size / length.

□ When designing the internal parts in the anti-vibration handle, the additional movement from the decoupling of the hand-held power tool must be taken into account.

□ Dust protection must be ensured.

□ The switchover from the hammer switch as a function of an operating mode of the hammer, in particular the switching of the switch function and the lockability of the hammer switch, should continue to be maintained.

Disclosure of the invention

The invention relates to a handle device for a hand tool, which has a Betriebsartenumschaltvorrichtung and a drive device for driving an insert tool in different modes, having at least one spring element and with a machine housing at least limited movably mounted handle unit, which over the at least one spring element the machine housing is at least partially vibration decoupled.

It is proposed that the handle device comprises at least one screw plate, which is intended to fix the spring element positively and non-positively.

The handle device according to the invention with the features of the main claim solves the task in a simple to assemble and cost-effective manner. It fulfills all requirements placed on it.

The measures listed in the dependent claims and in the following description of the embodiments, advantageous refinements and improvements of the main claim features. Thus, it is further proposed that the screw plate surrounds a clamping region of the spring element up to a contact zone to the handle unit in all directions. As a result, in particular a stable, high-quality, compact and cost-effective design and connection of the handle device to the power tool can be made possible.

In addition, it is proposed that the screw plate has at least one screw dome, which is provided for screwing the spring element to the handle unit. As a result, an easily mountable and cost-effective design of the handle device can be achieved.

Furthermore, it is proposed that the handle device a

Switch actuator comprises a commissioning of the drive device, wherein the switch actuator can be switched both mono-stable and bi-stable between two switching positions. In this context, the term "bi-stable" is to be understood as meaning, in particular, that the switch actuator has two stable switching positions into which the switch actuator can be switched low-cost design of the handle device can be achieved.

In addition, it is proposed that the handle device comprises an intermediate plate which is provided in the machine housing and which accommodates at least the spring element unilaterally, and a control means by which the switch actuator cooperates with the mode switching device such that in certain modes of the switch actuator are not bi-stable switched can. By "monostable" is to be understood in this context in particular, that the switch actuator only has a stable switching position, in which the switch actuator can be switched or in which the switch actuator preferably falls back automatically, while the switch operator in at least one other switching position of an operator in particular As a result, an easily mountable and cost-effective design of the handle device can be achieved, and it is also proposed that the control means be designed as a drawstring

Tieback may preferably be made of one plastic or another, a specialist man be made as meaningful appearing material. The tension band preferably has an at least substantially rectangular cross section with an at least substantially circular-like, in particular circular middle fiber. It is also conceivable for the middle formers to have an at least essentially four- or hexagonal or another cross-section which appears expedient to a person skilled in the art. The middle fiber is preferably provided to serve at least partially as a filling channel, in particular during an injection process, and / or to form an advantageously narrow contact line with the leaf spring. As a result, an advantageous cost-effective design can be achieved.

In addition, it is proposed that the at least one spring element is formed by a leaf spring. As a result, in particular a preferably cost-effective implementation and an advantageously simple assembly of the handle device can be achieved.

Furthermore, it is proposed that the handle device has at least one secondary spring element, which is formed by an elastomeric spring element. As a result, in particular, the spring element formed by the leaf spring can be advantageously supported in a spring action, and use of the handle device, in particular in larger and more powerful hand tool machines, can be achieved.

It is also proposed that the secondary spring element is acted upon only after a certain compression travel. It is proposed that the spring stiffness of the spring element formed by the leaf spring is adjusted so that with a

Einfederweg between 2 mm and 10 mm, preferably between 3 mm and 7 mm, more preferably between 4 mm and 5 mm minimum operating pressure points for most important applications can be achieved. From this Andruckschwelle the secondary spring element begins to act. The more the volume of the

Elastomer spring element is deformed during compression, the stiffer is a

Characteristic of the secondary spring element.

It is therefore further proposed that the volume compression of the

Elastomer spring element is designed such that with an additional compression of 2 mm to 5 mm, in particular from 3 mm to 4 mm beyond a minimum operating pressure point, the elastomeric spring element to 70% of its original volume is compressed. In a further compression of 1 mm to 2 mm, virtually the entire volume of the elastomeric spring element is applied, so that the spring stiffness increases relatively quickly. This has the advantage that in a case on the Antivibrati- onshandgriff very much energy can be absorbed, so that the impact-like components are less loaded.

It is also proposed that the screw plate is provided to receive the at least one secondary spring element. As a result, in particular a stable, high-quality, compact and cost-effective design and connection of the handle device to the handheld power tool can be made possible.

drawing

Further advantages emerge from the following description of the drawing. In the drawing, several embodiments of the invention are shown. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Show it:

1 a shows a handheld power tool with a handle device according to the invention in a schematic side view,

Fig. 1 b shows a detail of the handle device according to the invention in a

Sectional view

2 shows an assembly of the handle device according to the invention in a perspective view,

3a shows a detail of the handle device according to the invention in one

Sectional view

3b, the assembly of the handle device according to the invention in a

Sectional view

4a shows a detail of the handle device according to the invention in a

Sectional view 4b an alternatively configured section of the handle device according to the invention in a sectional view,

Fig. 4c shows a detail of the handle device according to the invention in one

Sectional view

Fig. 5 shows a detail of the handle device according to the invention in a

Sectional view

6a shows a part of the assembly of the handle device according to the invention in a perspective view,

6b shows a part of the assembly of the handle device according to the invention in a side view,

6c shows a part of the assembly of the handle device according to the invention in a side view,

7a shows a control means of the handle device according to the invention in a schematic representation,

Fig. 7b, the control means of the handle device according to the invention in a

Sectional view

Fig. 7c, the control means of the handle device according to the invention in a

Sectional view

8a shows a detail of the handle device according to the invention in one

Sectional view

8b shows a detail of the handle device according to the invention in one

Sectional view

8c shows a detail of the handle device according to the invention during assembly in a sectional view,

9 is a detail of the handle device according to the invention in a schematic representation,

Fig. 10 shows a detail of the handle device according to the invention in a

Sectional view

Fig. 1 1 a detail of the handle device according to the invention in a

Sectional view along the section line Xl-Xl,

12a shows a detail of the handle device according to the invention in one

Sectional view

Fig. 12b shows a detail of the handle device according to the invention in one

Sectional view

Fig. 13 shows a detail of the handle device according to the invention in one

Exploded 14a shows a detail of the handle device according to the invention in a sectional view,

Fig. 14b shows a detail of the handle device according to the invention in one

Sectional view along the section line XIVb-XIVb and

Fig. 15 shows a detail of the handle device according to the invention in a

Sectional view.

Description of the embodiments

1 shows a schematic view of a drill and / or chisel hammer as an example of a hand tool 10 with a machine housing 20, a tool holder 54 movably mounted on the machine housing 20 for exchangeable reception of an insert tool 16 and with a housing 20 accommodated in the machine housing, a drive unit and a gear unit having drive device 14 for driving the insert tool 16 in different modes. The tool holder 54 is preferably rotatably arranged on an end face of the machine housing 20. On one of the front side of the machine housing 20 opposite side of the machine housing 20, a handle device is further provided in the example of Figure 1 further. The handle device comprises in the present example a switch actuator 24 for commissioning the drill and / or chisel hammer. The switch actuator 24 can be switched both monostable and bi-stable between two switching positions. Furthermore, an additional handle device 56 is arranged on the machine housing 20 of the drill and / or chisel hammer, in particular arranged adjustable. The hand tool 10 has an operating mode switching device 12. In addition, a control lever for a mode switch is arranged on the machine housing 20, with which an operator can choose between different drive types for the insert tool 16 used in the tool holder 54.

The handle device for the power tool 10 comprises a spring element 18 and a at least limited movably mounted on the machine housing 20 handle unit 22 which is vibration-decoupled via the spring member 18 relative to the machine housing 20 and the switch actuator 24 includes a commissioning of the drive device 14. The handle unit 22 includes an anti-vibration handle 58. The handheld power tool device further includes Control means 28 through which the switch actuator 24 cooperates with the Betriebsartenumschalt- device 12 such that in certain modes of the

Switch actuator 24 can not be bi-stable switched. The control means 28 is designed as a drawstring 30. The u.a. shown in Figure 2 is composed of the following functional units: an intermediate plate 26, the spring element

18 and a slide valve assembly. The intermediate plate 26 is the central component of this assembly. Their structure allows a number of possibilities for the simple implementation of existing functions in the hand tool 10 formed by the hammer when using the anti-vibration handle 58 and a mechanical switch operation with switching.

One of the central tasks of the intermediate plate 26 is the receiving and guiding of the spring element 18, as shown in Figures 3a and 3b. The spring element 18 is clamped by the intermediate plate 26 in the anti-vibration handle 58 and fixed at the clamping point over a contour. The contour is preferably in one

Contact surface realized on the intermediate plate 26, on which the spring element 18 can be supported. The curve of this contour determines stiffness, bending line and paths of the spring element 18. The spring element 18 is designed as a leaf spring 32. Furthermore, the intermediate plate 26 serves as a stop for or as a stop for one or more secondary spring elements 34, 34 ', 34 ", which can serve as damping elements. FIGS. 4a to 4c show conceivable variants and embodiments of the secondary spring elements 34, 34', 34 "presented. According to FIGS. 4a to 4c, pockets with supporting ribs 60 and a frame 62 additionally provide for the introduction of damping elements into the intermediate plate 26. The secondary spring elements

34, 34 ', 34 "may preferably be formed of foam, cellular rubber, sponge rubber, another synthetic or natural foam, elastomer, TPE, rubber, a gel or similar elastic material The degree of damping or suspension may be In addition, it is possible to adjust the volume of individual chambers

Prevents components.

Suspension and damping are consequently adjusted centrally via the reception of the spring element 18 and the secondary spring elements 34, 34 ', 34 "in the intermediate plate 26. The result is the compact subassembly which is intended for pre-assembly and which contains all the essential components for the Interdependency of the coupling with each other. The principle facilitates the coordination of the components for decoupling and also opens up the possibility to derive by omitting the assembly without much effort a rigid handle of the handle unit 22 without switching from it.

The particular embodiment of the intermediate plate 26 also allows improved guidance of the power tool 10 and in particular an improved transmission of operating forces on the anti-vibration handle 58 on the machine housing 20 of the power tool 10. According to Figure 5 are in the upper part of a handle housing 64 and at the connection to the one Motor support assembly comprising 14 support points and recordings of the intermediate plate 26 designed so that along the power flow from the anti-vibration handle 58 operating forces unfiltered or unsprung can be transferred to the power tool 10. This results in a good control of the hand tool 10.

The intermediate plate 26 is provided in the machine housing 20 and receives the spring element 18 on one side. Finally, in the intermediate plate 26, the slide valve assembly is added The slide valve assembly consists in accordance with the figures 6a to 6c of a slide valve 66, the drawstring 30 and a Kompen- sationsfeder 68. It forms next to the intermediate plate 26 is another important unit especially in the transmission of switching - or switching paths to the switch actuator 24. The trained as a drawstring 30 control means 28 is made of plastic.

As a result, dimensional dependencies, which have an effect on the mode switching by the switch actuator 24, can be regulated in only one component. It takes little space. The assembly is easy. The widened head rest on the slide 66 coupled with jumps / steps in the guide prevents dust trapping between sliding surfaces. As a result, a malfunction can be avoided by clamping on the slide valve 66 in principle.

The z-shaped, cranked slide switch 66 can be pushed into the intermediate plate 26 with a simple sliding movement and locked in place by means of a snap hook connection, not shown, in the intended installation position. It is also conceivable that the z-shaped, cranked slide switch 66 can rotate into the intermediate plate 26 with a simple pivoting movement. The aspect ratio The guide surfaces with each other ensures sufficient pre-centering during the entire pre-assembly. A wrong assembly is thereby excluded.

For a mode-dependent switching from the hammer switch according to the document DE 197 20 947 A1, the disclosure of which is explicitly referenced at this point, the path and the power of a control lever must be transmitted mechanically smoothly to a switch from the Schalterbetätiger in the handle. In combination with an antivibration handle, approaches similar to the document DE 10 2010 038 753 A1, in which a tension band is arranged in the neutral fiber of the movement of the handle, are revealed.

Frictional losses, deformation of the spring element 18 and aspects of the manufacturing process, however, make it difficult to implement this concept in practice.

For this reason, especially the material and geometry are crucial for the execution of the drawstring 30. As a material, plastic offers a great variety of variations in order to combine low friction values with good emergency running properties and low dust susceptibility. Therefore, a plastic is fundamentally a very suitable material for this application.

In order to achieve sufficient rigidity for the transmission of tensile forces, while at the same time lose flexibility for a driving on the spring element 18, cross-sectional conditions are determining.

A band cross section of the tension band 30 must be very flat in height and long in the width. In the present construction, a rectangular cross-section with an aspect ratio of 1: 10 combined with a substantially circle-like, in particular circular, middle fiber was chosen (see FIGS. 7a to 7c), but cross-sections with rounded corners and / or deviating aspect ratios, in particular in FIGS Range between 1: 2 to 1: 20, more preferably from 1: 5 to 1: 15 be advantageous.

Area shares are variably adjustable over the entire length of the drawstring 30, but must remain balanced in total. Thus, in spite of eyelets and deflection during use, an always constant tension in the tension band 30 is maintained. hold. It can be ensured uniform loading of the material.

Between stiffness and flexibility also helps the variation of the area proportions. The substantially circle-like, in particular circular portion serves to fill the mold in the manufacturing process and at the same time advantageously increases the strength.

Due to manufacturing tolerance, thermal-elastic length changes, shrinkage / recrystallization and the pronounced flow behavior of plastic under load of the tension band 30, sum up in the transmission of tensile forces and paths on the drawstring 30, which is made of plastic, differences that a safe and ensure satisfactory function of the switch actuator 24 by mechanical means only conditionally.

With the help of the compensation spring 68 (see Figure 6a), these difficulties can be solved easily.

In the bias of the compensation spring 68, a buffer is created by the installation situation in the slide valve 66, which can compensate for any blurring of manufacture and mechanical behavior of the tension band 30, which is made of plastic.

The drawstring 30 must have a body for receiving the compensation spring 68 and safely taken up with the help of two rotational recordings in the slide valve 66 / performed. The slide valve 66 supports the compensation spring 68 on the opposite side and determines the measure of the compensation over the installation length.

Upon actuation of the switching, the path from the slide valve 66 is now transmitted force-dependent on the drawstring 30 and the switch actuator 24 (see Figures 8a and 8b). The coupling is no longer rigid but linear-elastic. The paths between the slide valve 66 and switching lever on the switch actuator 24, which forms a hammer switch, are designed so that a reserve is always kept in the compensation spring 68. This reserve from the length of the compensation spring 68 in operation can for a tolerance compensation and compensation of thermal, elastic as well as plastic changes in length on the drawstring 30, made of plastic is to be used. It is an overload protection ensured and now defined by the compensation spring 68 tensile forces applied to the drawstring 30.

For ease of assembly, an opening in the guide was left on the slide switch at the front and the pull strap 30 was snap-fitted, i. provided (see Figure 8c). The drawstring 30 is tuned in width to the inclusion in the slide valve 66. As a result, the tension band 30 together with the compensating spring 68 can simply be threaded through the receptacle in the slide switch 66. The components are then automatically pulled into their installed position via the force in the intended direction of pull and remain secured therein.

For effective dust protection, a labyrinth 70 is further provided over the intermediate plate 26, which in order to cover the machine housing 20 enclosing a striking mechanism housing and a housing cover, the drive assembly 14 comprising an engine assembly and the anti-vibration handle 58 reach inwards (see FIG. 9). The labyrinth 70 engages the transitions into the surrounding parts and, especially during the switching of the switch actuator 24 formed by the hammer switch, effectively ensures dust protection and safe operation. Additional sealing elements are not required.

Another aspect of the invention relates to the fact that with larger and more powerful hand tool machines 10, such as e.g. in heavy drilling and chipping hammers, the above-described fixation of the leaf spring 32 between the anti-vibration handle 58 and the machine housing 20 is no longer sufficient. For example, here the leaf spring 32 is no longer sufficient as the sole spring element. Additional secondary spring elements 34 must still be introduced between the machine housing 20 and the leaf spring 32 in order to support the too soft leaf spring 32 in its spring action. The secondary spring elements 34 are each formed by an elastomeric spring element 36.

According to the document DE 10 2006 029 630 A1, the leaf spring can be acted upon by a clamping piece and the screw plate only on the back side functionally or with forces. On the side of the leaf spring facing the device side, no holding or fixing functions or forces can be introduced. The invention thus represents an extension of the solution known from the publication DE 10 2006 029 630 A1, to be able to implement the presented there anti-vibration handle concept even with larger and more powerful hand tool machines.

The operator-held anti-vibration handle 58 includes the switch actuator 24 formed as an on-off switch, and is closed by screwing a handle of the anti-vibration handle 58 rearward.

At the top, the leaf spring 32 is clamped between the anti-vibration handle 58 and two screw plates 48. The two screw plates 48 are pushed in the transverse direction on both sides of the leaf spring 32. The screw plates 48 thus enclose an upper clamping region 50 of the leaf spring 32 up to the contact zone to the anti-vibration handle 58 in all spatial directions. This ensures a durable and stable enclosure of the leaf spring 32. In the screw 48 are screw dome 52, which serve for screwing the screw 48 and thus one of the leaf spring 32 with the anti-vibration handle 58. The screw 48, the leaf spring 32, the anti-vibration handle 58 and a strained bellows 72 form a fastening system, which is held together advantageously on form and frictional connection. The positive connection is formed by mutually supporting and penetrating retaining domes and ribs, so that the adhesion has only a fixing function and the essential forces are absorbed by the positive connection of the components.

A significant advantage of the screw plates 48 pushed on both sides is the provision of additional functional surfaces in front of a region and laterally of a region of the screw plates 48 of the leaf spring 32.

In the front region, the screw plates 48 are formed so that they can accommodate the additional secondary spring elements 34. In addition to spring mounts, the screw 48 have additional functions. In order to prevent tearing out of the anti-vibration handle 58 and thus also an overload of the leaf spring 32, the screw plates 48 have lateral contact surfaces, which are supported on the back of two, designed as rear plates back plates 38. As a result, the anti-vibration handle 58 has a stable and defined back stop. Another function of the screw 48 is the lateral guiding and covering the control means 28 formed by the tension band 30 relative to that of a

Elastomer formed secondary spring element 34. With the drawstring 30 is the of inhibited the switch actuator 24 formed during a Meißeins so that the operator does not press the switch actuator 24 constantly. The drawstring 30 must be able to slide smoothly on the leaf spring 32 and must not be jammed or pinched.

During the pushing together of the two screw plates 48 on the leaf spring 32, the tension band 30 is chambered in a slot of the screw 48. Also, the bellows 72 is chambered by the screw plates 48 in the anti-vibration handle 58. Furthermore, the screw 48 also form the end stop in the longitudinal and vertical directions of the anti-vibration handle 58th

The lower Blattfederklemmung has been integrated into the screw system of the back plates 38 to the machine housing 20 advantageously (see Figures 14a and 14b). The previously one-piece backplate was split into two mirror-symmetrical backplates 38 in order to fulfill all required functions, favorable mountability and mold endformability.

As with the document DE 10 2006 029 630 A1, the bellows 72 already mounted on the antivibration handle 20 and the rocker arms (not shown) are chambered during assembly by pushing the two back plates 38 together. Due to the required bias of the leaf spring 32, the leaf spring 32 is then a bit of the back plates designed as housing rear plates 38 from. In order to simply press the leaf spring 32 in its operating position during assembly, a spring plate 40 is inserted above with its two retaining ribs 42 in two corresponding retaining grooves 44 formed as housing rear plates back plates 38 and then folded against a leaf spring tension in the direction of the back plates 38 to the rear , In order to hold this position, two snap hooks 46 are integrated in the back plates 38, which engage in the spring plate 40 and hold them in the mounting position. The thus pre-assembled complete, designed as a handle assembly handle device can then be applied in an assembly line on the core device.

For clamping the leaf spring 32 both positive and positive elements are used. As a positive connection, the leaf spring 32 has at its lower end two openings and a Abfalzung 74. The leaf spring 32, the spring plate 40 and the machine housing 20 are on two domes of the respective side of the Housing rear plates formed back plates 38 threaded. Furthermore, the spring plate 40 engages around the two screw domes of the machine housing 20. The Abfalzung 74 of the leaf spring 32 is clamped between the back plates 38 and the spring plate 40. By screwing the rear plates 38 formed by the housing rear plates with the machine housing 20, all parts are clamped together. The advantageous nesting of the components into one another produces a permanent connection which withstands the high vibration load in the hand-held power tool 10 formed by a striking power tool. Also in the case of a bias loss in the screw connection due to

Settling or dissolution processes, the connection is maintained due to the positive connection. The spring plate 40 is designed in its contour height so that the leaf spring 32 is firmly clamped down to about 25% of its length. The remaining length can cantilever freely during compression.

Another aspect of the invention is the combination of the leaf spring 32 as the primary spring element and the at least one further secondary spring element 34, which is acted upon only after a certain compression travel. Figure 15 shows a cross section through the upper portion of the anti-vibration handle

58 with the leaf spring 32 and the secondary spring element 34. The screw plates 48, with which the leaf spring 32 is enclosed, are forwardly formed so that they can still receive one or the additional secondary spring elements 34. In the embodiment shown, e.g. a foamed elastomer molding is inserted between the screw plate 48 or the leaf spring 32 and the spring plate 40. The

Elastomer molding is formed as the elastomeric spring element 36 and forms the secondary spring element 34.

Foamed elastomer moldings have the advantage of cost-effective production by a continuous extrusion molding process with subsequent cutting to the required length. Furthermore, they act in virtually all spatial directions, i. they have no preferential direction, e.g. a helical compression spring.

The advantageous, formed as Elastomerfederelement 36 secondary spring element 34 supports the leaf spring 32 at loads that are above an optimal Betriebsandruckpunkts. The optimal operating pressure point is the minimum pressure which The operator just has to provide, so that the power tool 10 formed by the hammer drill performs a regular and clean impact operation. This operating pressure is dependent on the power class of the power tool 10 and the particular application.

That by providing a certain clearance of the elastomeric spring element 36 between the abutment surfaces, an at least two-stage spring characteristic is generated. Until the operating pressure point, only the leaf spring 32 acts, so that a very good decoupling of the anti-vibration handle 58 with a low vibration level can be achieved. A good decoupling is achieved in this area, especially because the leaf spring 32 has a very low damping constant. In an overpressure or in a case of the power tool 10 on the anti-vibration handle 58 then takes the elastomeric spring element 36 to the significant proportion of loads.

It is proposed that the spring stiffness of the leaf spring 32 be set so that the minimum operating pressure points for most important applications are achieved with a compression travel between 2 mm and 10 mm, preferably between 3 mm and 7 mm, particularly preferably between 4 mm and 5 mm , From this Andruckschwelle the secondary spring element 34 starts to act. The more that

It is therefore further proposed that a volume compression of the elastomeric spring element 36 is designed such that with an additional compression of 2 mm to 5 mm, in particular of 3 mm to 4 mm beyond the minimum operating pressure point

Elastomer spring element 36 is compressed to 70% of its original volume. With further compression of 1 mm to 2 mm, almost the entire volume of

Elastomer spring element 36 acted upon, so that the spring stiffness increases relatively quickly. This has the advantage that in a case on the anti-vibration handle 58 a lot of energy can be absorbed so that the impulsive acted upon

Less stress on components. A described compression characteristic can also be effected or supported by a targeted shaping of the elastomer spring element 36. It is thus also possible to install tubular or other contours that can be generated in one extrusion process. The elastomeric spring element 36 is preferably made of foamed elastomer (foam rubber), which is produced in a continuous extrusion molding process with subsequent cutting to length

Claims

claims

1 . A handle apparatus for a hand tool machine (10) having a mode changeover device (12) and a drive device (14) for driving an insert tool (16) in different modes, comprising at least one spring element (18) and one on a machine housing (20). at least a limited movably mounted handle unit (22), which is at least partially vibration-decoupled via the at least one spring element (18) relative to the machine housing (20), characterized by at least one screw plate (48), which is intended to deform the spring element (18) formally. and to fix it firmly.

2. Handle device according to claim 1, characterized in that the

Screw plate (48) encloses a clamping region (50) of the spring element (18) except for a contact zone to the handle unit (22) out in all directions.

3. Handle device according to one of the preceding claims, characterized in that the screw plate (48) has at least one Schraubdom (52) which is provided for screwing the spring element (18) with the handle unit (22).

4. Handle device according to one of the preceding claims, characterized by a switch actuator (24) for commissioning the drive device (14), wherein the switch actuator (24) can be switched both mono-stable and bistable between two switching positions. Handle device according to claim 4, characterized by an intermediate plate (26) which is provided in the machine housing (20) and which accommodates at least the spring element (18) on one side, and a control means (28) via which the switch actuator (24) with the operating mode switching device (24). 12) cooperates such that in certain modes of the switch actuator (24) can not be switched bistable.

Handle device according to claim 5, characterized in that the control means (28) as a drawstring (30) is formed.

Handle device according to one of the preceding claims, characterized in that the at least one spring element (18) by a leaf spring (32) is formed.

Handle device according to one of the preceding claims, characterized by at least one secondary spring element (34), which of a

Elastomer spring element (36) is formed.

Handle device according to claim 8, characterized in that the secondary spring element (34) is acted upon only after a certain compression travel.

10. Handle device at least according to claim 8, characterized in that the screw plate (48) is provided to receive the at least one secondary spring element (34).

1 1. Hand tool (10), in particular drill and / or chisel hammer, with a handle device according to one of the preceding claims.

12. drawstring (30) of a handle device at least according to claim 6, which is made of plastic.

Tieback (30) according to claim 12, characterized by a substantially rectangular cross section with a substantially circular middle fiber.