WO2009089961A1

WO2009089961A1 - Handle for a hand-held power tool

Info

Publication number: WO2009089961A1
Application number: PCT/EP2008/066869
Authority: WO
Inventors: Axel Kuhnle; Karl Frauhammer; Willy Braun
Original assignee: Robert Bosch Gmbh
Priority date: 2008-01-17
Filing date: 2008-12-05
Publication date: 2009-07-23
Also published as: ATE550150T1; EP2244861A1; DE102008004875A1; EP2244861B1; ES2380300T3

Abstract

The invention relates to a handle for a hand-held power tool, comprising a hollow grip element (2), a clamping holder (3), and a damping device (6). The clamping holder (3) further comprises a housing (4) and a tensioning belt (5), wherein the tensioning belt (5) is disposed about a partial region of the hand-held power tool, the damping device (6) comprises a sleeve (7) and a sleeve-like damping element (8) and is disposed in the interior of the hollow grip element (2), wherein the sleeve-like damping element (8) is disposed on the exterior of the sleeve (7) and an interior surface of the hollow grip element (2) comes in contact with the sleeve-like damping element (8). The invention further provides an attachment element (9, 11), which is connected to the tensioning belt (5) and fixed to the sleeve (7).

Description

description

title

Handle for an electric hand tool

State of the art

The present invention relates to a handle for an electric hand tool according to the preamble of claim 1.

Hand grips for electric hand tools are for example in drills or

Drilling hammers known. When using such electric hand tools large vibrations are sometimes generated, which complicate a precise and fatigue-free work. For this reason, DE 10 2004 017761 A1 has proposed a vibration-damped handle for an electric hand tool which can be screwed to the tool by means of a threaded bolt and which in an inner region and at an outer region on a

Handgrip is sprayed or molded with a vibration-damping material. The vibration-damping material is injection-molded in one operation continuously in the interior and exterior. The disadvantage of this known handle, however, is that it is relatively expensive to manufacture and requires a complex manufacturing process. Furthermore, a material selection for the handle is limited by the common encapsulation on the outside of the handle.

Advantages of the invention

The handle according to the invention for an electric hand tool with the features of

Patent claim 1 has the advantage over that it allows for a very simple and inexpensive construction excellent vibration reduction for a user. At the same time, a required operating rigidity and robustness is ensured in the case of the handle according to the invention, so that a secure working feeling can be obtained by a user. This is inventively achieved in that the handle has a hollow handle member, a clamp holder and a Dämpfungsemrichtung. Of the Clamping holder comprises a housing and a clamping band, wherein the clamping band is arranged in the mounted state around a portion of the electric hand tool around. The damping device comprises a sleeve and a sleeve-like damping element, which is slipped over the sleeve. The damping device is arranged in the interior of the grip element, wherein the sleeve-like damping element has an inner surface of the hollow

Touched handle element. Furthermore, the handle comprises a fastening element, which is connected to the clamping band of the clamping holder and is fixed to the sleeve. As a result, a connection between the handle element and the clamping holder is realized. Through the connection with the tensioning band can also be realized on the fastener at the same time also a tensioning of the clamping band on the electric hand tool, so that at the same time in addition to the

Connection of the handle element and clamp holder and a tensioning of the clamping band takes place. Preferably, in this case, a thread is formed between the fastening element and the sleeve.

The dependent claims show preferred developments of the invention.

More preferably, a spring damping element is arranged between the handle element and the clamping holder on the outer side of the handle. The spring damping element is circumferentially closed and provides an additional damping function when vibrations are transmitted from the clamp holder to the handle element. This can thus be a double

Damping be achieved on the one hand on the spring damping element and on the other hand on the sleeve-like damping element in the hollow handle member.

Particularly preferably, the grip element has an outwardly directed handle plate, wherein one end of the spring bellows designed as a spring damping element is supported on the handle plate. As a result, in particular a large support surface for the spring bellows on the grip element is ensured.

In a further preferred embodiment, a tapered region is formed in the hollow grip element and the sleeve-like damping element touches or contacts the tapering region of the sleeve

Handle element on. This ensures that sufficient damping is provided even when a slight angular position between the handle element and the clamping holder occurs due to a large force by a user when using the electric hand tool. Particularly preferably, the tapered region in the hollow grip element is an arc-shaped region in the section, so that the damping element bears against a bell-shaped inner region of the grip element. According to a further preferred embodiment of the invention, the fastening element is a hammer screw with a flattened head area. The clamping band of the clamping holder is fixed to the flattened head area, so that a secure clamping of the clamping band is made possible.

More preferably, the Federfaltenbalg is attached to the clamp holder by means of a latching connection or alternatively, the Federfaltenbalg is formed integrally with the clamping holder.

More preferably, the spring bellows made of a thermoplastic elastomer or a

Made of rubber. If the spring bellows is made of a plastic, it is particularly preferred that a housing of the clamping holder and the Federfaltenbalg are produced simultaneously by plastic injection molding.

According to a further preferred embodiment of the present invention, the

Handle member inside a plurality of longitudinal ribs which extend in the longitudinal direction of the grip member and project radially inwardly. The longitudinal ribs are preferably arranged at equal intervals along the inner circumference of the handle member and allow a rotationally fixed connection between the handle member and the sleeve-like damping element.

Particularly preferably, the sleeve-like damping element groove-shaped recesses on the outside, which are formed in the longitudinal direction of the damping element and in which engages in each case one of the longitudinal ribs of the grip element. As a result, twisting of the damping element relative to the grip element is prevented with great certainty.

To ensure a firm connection between the sleeve and the sleeve-like damping element of the damping device, the sleeve comprises at its outer periphery a plurality of protruding portions and the sleeve-shaped damping element comprises on its inner circumference a plurality of recesses which are complementary to the above

Areas are formed. The protruding areas then engage in the recesses. It should be noted that, of course, the protruding areas may be provided on the damping element and the recesses on the sleeve. As projecting areas, longitudinal ribs are particularly preferably used, and longitudinal grooves are used as recesses. The protruding areas or recesses thus prevent one

Relative rotation between sleeve and damping element. - A -

Furthermore, the present invention relates to an electric hand tool, in particular an electric hammer or a drill or a grinding machine o.Ä. with a handle according to the invention. The handle is preferably arranged on a front region of the machine as an additional handle, wherein a relative orientation of the handle is made possible by adjusting the tension band of the handle.

drawing

Hereinafter, a preferred embodiment of the invention will be described in detail with reference to the accompanying drawings. In the drawing is:

1 shows a schematic, perspective view of a handle according to an embodiment of the invention,

FIG. 2 is a longitudinal sectional view of the handle shown in FIG. 1;

Figure 3 is a sectional view taken along the line HI-III of Figure 2 and

Figure 4 is a longitudinal sectional view of the handle, which is a

Damping effect clarified.

Preferred embodiment of the invention

Hereinafter, a handle 1 according to a preferred embodiment of the invention will be described in detail with reference to Figures 1 to 4.

As can be seen from FIG. 1, the handle 1 comprises a gripping element 2 and a clamping holder 3. The clamping holder has a housing 4 and a clamping band 5. The clamping band 5 is arranged and stretched around a portion of an electric hand tool, so that the handle 1 is attached to the electric hand tool. In order to achieve a vibration damping, a damping device 6 is arranged between the grip element 2 and the clamping holder 3 (see FIG.

The damping device 6 comprises a sleeve 7, which is made of a plastic, and a sleeve-like damping element 8. As can be seen from FIG. 2, the damping element 8 is arranged at the outer region of the sleeve 7. The damping element 8 also has a substantially sleeve-like shape and is placed over the sleeve 7. In order to avoid a rotation between the sleeve 7 and the damping element 8, has, as can be seen from Figure 3, the sleeve 7 at its outer periphery a plurality of outer

Longitudinal ribs 7a on. In a corresponding manner, a plurality of inner longitudinal grooves 8a are formed on the inner circumference of the damping element 8. As a result, the outer longitudinal ribs 7a of the sleeve 7 can engage in the inner longitudinal grooves 8a of the damping element 8. Since the damping element 8 is elastic, an assembly by coating the damping element on the sleeve 7 is easily possible. The damping element 8 also has on its outer

Circumference to a plurality of outer longitudinal grooves 8b. Furthermore, the hollow grip element 2 has on its inner periphery a multiplicity of inwardly projecting longitudinal ribs 2d. As can be seen from FIG. 3, the protruding longitudinal ribs 2d of the gripping element 2 engage in the outer longitudinal grooves 8b of the damping element 8 and likewise prevent the damping element 8 from rotating relative to the gripping element 2. It should be noted that in this exemplary embodiment, respectively six longitudinal ribs resp Longitudinal grooves are provided between the damping element 8 and the grip element 2 or the damping element 8 and the sleeve 7. However, any other number is possible.

As can be seen further from FIG. 2, a tapered region 20 is provided on the inner circumference of the grip element 2, which region is curved in section. The damping element 8 has a corresponding tapered region 8c at its end region directed towards the clamping holder 3. As a result, this end region of the damping element 8 has a bell-like shape. The damping element 8 applies itself to the tapered portion 20 of the handle member 2, to the largest possible

Ensure contact area between the damping element 8 and the handle element 2.

Furthermore, a recess 7 c is formed on the end of the sleeve 7 facing away from the clamping holder 3. In the recess 7c, a nut 11 is fixed, for example by means of gluing or via a press fit. The handle 1 further comprises a fastening element 9 which fixes the clamping holder 3 with the grip element 2. In this embodiment, the fastener is a hammer screw 9 with a flattened head portion 9 a, wherein the hammer screw 9 is screwed to secure the clamping holder 3 on the handle element 2 in the nut 11. At the head portion 9a, the tension band 5 is fixed, such that the radial Outside areas of the head portion 9a project beyond an outer region of the tension band 5. The radial outer region of the head region 9a is also in contact with an inner side of the clamping holder 3. The fastening element 9 is, as can be seen from Figure 2, passed through the sleeve 7 and screwed into the nut 11. A screw connection between the fastening element 9 and the nut 11 is realized in such a way that by

Turning the handle member 2, the nut 11 is rotated and is screwed up along the thread of the fastener 9, so that the hammer screw 9 is pulled down. Since the hammer screw 9 is connected to the clamping band 5, this also causes a tensioning of the tension band 5.

The handle 1 further comprises an outer spring damping element in the form of a spring bellows 10. The spring bellows is made of an elastic plastic material and connected to the clamp holder 3 via a latching connection. As a result, the spring bellows can be fastened by simply latching to the clamp holder 3. The spring bellows 10 is supported at one end on a handle plate 2c of the grip element 2 (see FIG. 2). The spring bellows 10 provides an additional damping function, so that the damping device according to the invention comprises two damping-providing components, namely the sleeve 7 with the damping element 8 and the Federfaltenbalg 10. The Federfaltenbalg 10 is provided between the handle member 2 and the clamp holder 3 circumferentially in the form of a sleeve and thus can also provide a covering function for the area between the grip element 2 and the clamp holder 3. This prevents in particular the ingress of dirt. The spring bellows 10 is preferably made of thermoplastic elastomer and is preferably produced by injection molding. Since the spring bellows 10 has only a small wall thickness, short production cycles and low material costs can be realized.

The function for damping vibrations of the handle 1 is as follows. When vibrations are transmitted from the electric hand tool via the clamping band 5 and the housing 4, the vibrations are damped by the damping device 6 and the Federfaltenbalg 10. Figure 4 shows schematically a damping process, on the one hand the

Federfaltenbalg 10 is deformed and on the other hand, the damping element 8 of the damping device 6 is deformed. Here, the sliding of the spring bellows 10 on the handle plate 2c generates additional friction damping. The grip element 2 is exaggerated in Figure 4 in an angular position to the clamp holder 3, the double Dämpfüngsfünktion by the damping device 6 and the Federfaltenbalg 10 realistic represent. Due to the deformation of the damping element 8 and the Federfaltenbalgs 10 vibrations that are transmitted from the clamp holder 3 on the handle element 2, damped. As a result, a user of an electric hand tool, on which the handle 1 is mounted, has the advantage that not so many vibrations are transmitted to the grip element and thus to the user himself. This allows an improved ease of use of the handle can be achieved. A tilting of the handle 2 relative to the clamping holder 3 takes place substantially around a center in the region of the tapering portion 20 of the handle element 2. The hammer screw and the fixed sleeve 7 remain in its vertical starting position. The outer longitudinal ribs 7a of the sleeve 7 also form a

Stop for the tilting of the handle element 2.

An assembly or disassembly of the handle member 2 from the clamp holder 3 can be realized by simply turning the handle member relative to the clamp holder 3. The hammer screw 9 is rotationally fixed relative to the clamp holder 3, for example, by a rectangular head portion

9a, arranged. Thus, when the handle member 2 is rotated, the nut 11 is moved along the thread of the hammer screw 9. The longitudinal ribs or longitudinal grooves of the sleeve 7 and the damping element 8 thereby ensure a sufficient power transmission from the handle element 2 to the nut 11 safely. Thus, the grip element 2 together with the damping device 6 can be easily unscrewed or screwed again. Thus, if necessary, a

Replacement of a damaged damper element 8, for example, easily done.

It should be noted that it is of course also possible that the sleeve 7 is provided with an internal thread, so that the fastening element 9 can be fastened directly to the sleeve 7. Then can be dispensed with the mother and thus the number of parts of

Handle be further reduced.

Claims

claims

A handle for an electric hand tool, comprising a hollow gripping element (2), a clamping holder (3) and a damping device (6), characterized in that - the clamping holder (3) comprises a housing (4) and a clamping band (5), the

Clamping band (5) is arranged around a portion of the electric hand tool,

- The damping device (6) comprises a sleeve (7) and a sleeve-like damping element (8) and inside the hollow handle member (2) is arranged, wherein the sleeve-like damping element (8) on the outside of the sleeve (7) is arranged and a Inner surface of the hollow handle member (2), the sleeve-like damping element (8) touches, and

- Further, a fastening element (9, 11) is provided, which is connected to the clamping band (5) and is fixed to the sleeve (7).

2. Handle according to claim 1, characterized in that between the handle element (2) and the clamping holder (3) on the outer side of the handle, a spring damping element (10) is arranged, which is circumferentially closed and provides an additional damping function.

3. Handle according to claim 2, characterized in that the grip element (2) comprises an outwardly directed handle plate (2c) and the spring damping element (10) is designed as Federfaltenbalg and one end of the Federfaltenbalgs on the handle plate (2c) is supported.

4. Handle according to one of the preceding claims, characterized in that the hollow grip element (2) on its inner side a tapered portion (20) and the sleeve-like damping element (8) contacts the tapered portion (20).

5. Handle according to claim 4, characterized in that the tapered portion (20) of the grip element (2) is arc-shaped in section.

6. Handle according to one of the preceding claims, characterized in that the fastening element comprises a hammer screw (9) with a flattened head portion (9a) and the clamping band (5) on the flattened head portion (9a) is fixed.

7. Handle according to one of the preceding claims, characterized in that the handle element (2) on an inner side a plurality of radially inwardly projecting longitudinal ribs (2d).

8. Handle according to claim 7, characterized in that the sleeve-like damping element (8) has a plurality of groove-shaped recesses (8b) on an outer side, and in each case one of the longitudinal ribs (2d) of the grip element (2) in the groove-shaped recesses (8b) intervenes.

9. Handle according to one of the preceding claims, characterized in that the sleeve (7) at its outer periphery a plurality of projecting portions (7a), in particular longitudinal ribs, and the sleeve-like damping element (8) has a plurality of recesses (8a) on a Inner side, wherein the recesses (8a) and the protruding portions (7a) are formed complementary to each other and the protruding portions (7a) engage in the recesses (8a).

10. Electric hand tool, comprising a handle according to one of the preceding claims.