GB2484811A

GB2484811A - Isolating unit for hand-held power tool

Info

Publication number: GB2484811A
Application number: GB1117979.3A
Authority: GB
Inventors: Willy Braun; Juergen Lennartz
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2010-10-18
Filing date: 2011-10-17
Publication date: 2012-04-25
Also published as: DE102010042551A1; GB201117979D0; CN102452070A

Abstract

The isolating unit is for isolating an additional or auxiliary handle 10a of a hand-held tool 12a from machine vibrations, in use. The unit includes at least one interface 14a for attaching the additional handle 10a, at least one support region 16a and at least one isolating region 18a. The support region and the isolating region are of an integral construction. The isolating region may have a different wall thickness from the support region. The isolating region may also include at least one film hinge. The tool may be a hammer drill or any other power tool such as a saw, a screwdriver, a miller, a sander or an angle grinder etc.

Description

Hand tool machine isolating unit

Background art

From WO 2009/123267 Al a hand tool machine isolating unit for isolating an additional handle for a hand tool machine from hand tool machine vibrations is known, which comprises an interface for attaching the additional handle and at least one support region and at least one isolating region.

The support region and the isolating region are formed by separate components and connected to one another by spring elements.

Disclosure of the invention

The invention proceeds from a hand tool machine isolating unit for isolating an additional handle for a hand tool machine from hand tool machine vibrations, comprising at least one interface for attaching the additional handle, at least one support region and at least one isolating region.

It is proposed that the support region and the isolating region are of an integral construction. By a "hand tool machine isolating unit" is meant a unit, to which an additional handle for a hand tool machine is attached. By a "hand tool machine" is meant in particular a workpiece-processing machine, such as in particular a drill, a drilling-and/or chisel hammer, a saw, a plane, a screwdriver, a miller, a sander, an angular grinder, a gardening implement and/or a multifunctional tool. By a "support region" is meant a region of the hand tool machine isolating unit, at which the hand tool machine isolating unit is supported against a hand tool machine component, preferably against a housing of the hand tool machine, in particular against a gear unit housing or a percussion mechanism housing. By an "isolating region" is meant a region of the hand tool machine isolating unit that is partially isolated from the support region. Situated in the isolating region of the hand tool machine isolating unit is an interface, to which the additional handle is attached. What is meant by "partially isolated" is that the isolating region in at least one region has an increased elasticity and/or a reduced stiffness compared to the support region. Inparticular, the isolating region about at least one axis has a lower stiffness under flexure than the support region about a parallel axis. By "integral" is meant in particular cohesively connected, as for example by means of a welding process and/or glueing process etc., and particularly advantageously moulded on, for instance as a result of manufacture from a casting and/or as a result of manufacture in a single-or multi-component injection moulding process. Further supporting elements may be provided, in particular elastomer elements, by means of which the isolating region is additionally supported on a hand tool machine component and/or on the support region.

In this way it is advantageously possible to enable a perceptible vibration reduction for an operator. As a result of the integral construction an advantageous saving of components and reduction of costs may be achieved. The service life may be extended. Openings, through which dust and dirt may penetrate, may be avoided. A compact design may be achieved. The hand tool machine isolating unit may be disposed close to the point of origin of the vibrations.

It is possible to achieve the effect whereby the distance of the vibration source from the hand tool machine isolating unit is shorter than from a region of the additional handle, at which the operator holds the additional handle. By virtue of the short distance of the hand tool machine isolating unit from the point of origin of the vibrations and by virtue of a correspondingly advantageous leverage it is possible to achieve the effect whereby rotary vibrations in the region of the hand tool machine isolating unit result only in small translatory movements. The hand tool machine may therefore be of a relativeLy stiffconstruction in onedirectionof ±he translatory movements, such as in particular in axial direction of an axis of rotation of a drilling-and/or chisel hammer. A high operating stiffness and ruggedness may be achieved, which enables precise working with the hand tool machine. At the same time, a high vibration reduction is achievable for the operator. Comfort for the operator may be substantially increased.

It is further proposed that the isolating region has a different wall thickness from the support region. The wall thickness of the isolating region is preferably at least partially smaller than the wall thickness of the support region. The flexibility of the isolating region may be advantageously increased and good damping of vibrations may be achieved.

In a further form of the invention the isolating region comprises at least one film hinge. By a "film hinge" is meant a hinge that substantially takes the form of a thin-walled connection, which by virtue of its flexibility enables a limited rotational movement of the connected parts. The film hinge preferably has in at least one region a thinner wall thickness than the parts that are to be connected. The film hinge is preferably disposed in such a way that it connects the isolating region to the support region. The isolating region is connected preferably only at one end to the support region. An additional supporting element, in particular an elastomer element, may support the isolating region additionally on a -hand tool machine component, in particular on an end of the isolating region remote from the end connected to the support region. A particularly economical and durable connectionof the-isolating region and the support region may be achieved. An advantageous splitting of tasks may be achieved in that the film hinge inhibits in particular axial and rotatory relative movements, while permissible tilting movements are absorbed by the supporting element.

In a further form of the invention it is proposed that at least one additional support element is provided. The additional support element may be retro-fitted by pressing and/or glueing into regions of the hand tool machine isolating unit but it is preferably already integrated into the hand tool machine isolating unit in the course of manufacture, for example as an insert in a multi-component injection moulding process. The support element may take the form of a high-strength plastic part, being for example fibre-reinforced, in particular continuous strand-reinforced, or may be made for example at least partially of sheet metal and/or steel. The support element may additionally stiffen the structure of the isolating region, may serve as a further spring element and/or nay take the form of a stop element that restricts a permissible movement. A structure that is advantageously designed for the anticipated vibrations may be achieved and the vibration damping may be further improved for the operator.

In particular, the region of the isolating region having the interface for the additional handle may be configured S in suoh a way that it is capable of taking up for example the clamping forces of a clamping band that fixes the additional handle.

The support region and the isolating region are advantageously formed at least partially from materials of differing stiffness. What is meant by "materials of differing stiffness" is that in particular materials having a different modulus of elasticity are used. The isolating region may be formed for example partially from a plastics material, preferably a thermoplastic material, in particular from a thermoplastic elastomer, or from a deformation-modified plastics material. The support region may be formed for example entirely or partially from a plastics material that is stiffer than at least one region of the isolating region. The total wall thickness of a sub-region of the isolating-and/or support region or of the entire isolating-and/or support region may be formed from a different material or individual layers may be formed from different materials and/or different materials may be embedded or oonnected to the region. Particularly effective isolation and at the same time a high operating stiffness and ruggedness of the hand tool machine isolating unit may be achieved.

The various functional regions may be designed so as to be perceptible to the operator.

The hand tool machine isolating unit advantageously comprises at least one stop unit, which is provided for restricting a movement of the isolating region relative to the support region. The stop unit is preferably provided for stopping a movement of the isolating region before an inadmissible deformation is reached. The stop unit is preferably configured in such a way that the isolating region is supported on the support region and/or on a hand tool machine component and/or on some other suitable element and the movement and/or deformation is restricted.

-The stop unit i.s pxeferably connected tothe isolating region and/or part of the isolating region. A particularly rugged hand tool machine isolating unit may be achieved.

It is possible to prevent the hand tool machine isolating unit from being destroyed or damaged in the event of an overload.

In a particularly advantageous manner the hand tool machine isolating unit is configured at least partially as a hand tool machine protective housing. Here, by a "hand tool machine protective housing" is meant a housing that surrounds the hand tool machine or a region of the hand tool machine. By a "hand tool machine protective housing" is meant in particular a housing that is connected to another housing of the hand tool machine, for example a gear unit housing and/or percussion mechanism housing, so as to be protected against loss and in particular is provided for remaining inseparably connected to the other housing. In particular, the hand tool machine isolating unit may be configured as a protective hood of a drill that surrounds a gear unit housing and/or a percussion mechanism housing of the hand tool machine. The effect may advantageously be achieved whereby the hand tool machine isolating unit is situated particularly close to a main source of vibrations and hence a -for the operator -marked reduction of vibrations may be achieved with an advantageously stiff hand tool machine isolating unit. A compact design of the hand tool machine may be achieved.

Compared to a pure hand tool machine protective housing or a pure protective hood, the hand tool machine isolating unit requires no, or only a few, additional components. An ---advantageous cost-and material reduction may be achieved.

An amplifying effect in the transmission of housing vibrations to. an additional handle may be preve.ate.d.

A hand tool machine isolating unit for isolating an additional handle for a hand tool machine from hand tool machine vibrations is further proposed, comprising at least one interface for attaching the additional handle, at least one support region and at least one isolating region and comprising a coupling region that is provided for coupling to a hand tool machine housing. By a "coupling region" is meant a region of the hand tool machine isolating unit, by which the hand tool machine isolating unit is supported on the hand tool machine housing, in particular the gear unit housing and/or the percussion mechanism housing, and is fastened thereon so as to be locked against rotation and displacement. The hand tool machine isolating unit may be connected to the hand tool machine housing by clamping, screwing, glueing or some other detachable or non-detachable fastening technique. The effect may advantageously be achieved whereby there is a reliable connection between the hand tool machine and the hand tool machine isolating unit. The hand tool machine isolating unit may also be configured advantageously as a module that is separate from the hand tool machine and that is fastened to the hand tool machine and receives the additional handle. The hand tool machine isolating unit may also be used to advantage with hand tool machines, in which the gear unit housing or percussion mechanism housing is configured as part of the hand tool machine protective housing. The isolating of a main handle and the additional handle may be effected separately and may be better adapted to the individual requirements. An additional handle with a hand tool machine isolating unit is further proposed. An additional handle with a hand tool machine isolating unit may be used particularly advantageously with hand tool machines that do not contain a hand tool machine isolating unit.

Drawings Further advantages emerge from the following description of drawings. In the drawings embodiments of the invention are represented. The drawings, the description and the claims contain numerous features in combination. The features will advantageously be considered also individually and combined into meaningful further combinations by the person skilled in the art.

The drawings show: Fig. 1 a diagrammatic representation of a hand tool machine with a hand tool machine isolating unit and an additional handle of a first embodiment, Fig. 2 a section through the diagrammatic representation of the hand tool machine with the hand tool machine isolating unit and the additional handle of the first embodiment, Fig. 3 a section through a detail of the hand tool machine isolating unit in a second embodiment, Fig. 4 a section through a detail of the hand tool machine isolating unit in a third embodiment, Fig. 5 a further section through a detail of the hand tool machine isolating unit of the third embodiment, Fig. 6 a section through a detail of the hand tool machine isolating unit in a fourth embodiment, Fig. 7 a section through a detail of the hand tool machine isolating unit in a fifth embodiment, Fig. 8 a diagrammatic representation of a hand tool machine with a hand tool machine isolating unit and an additional handle in a sixth embodiment, Fig. 9 a section through the diagrammatic representation of the hand tool machine with the hand tool machine isolating unit and the additional handle of the sixth embodiment and Fig. 10 a section through a detail of the hand tool machine isolating unit of the sixth embodiment.

Description of the embodiments

Figure 1 shows a hand tool machine isolating unit for isolating an additional handle lOa for a hand tool machine l2a from hand tool machine vibrations, comprising at least one interface 14a for attaching the additional handle lOa, at least one support region l6a and at least one isolating region 18a, wherein the support region lEa and the isolating region l8a are of an integral construction. Two circumferential webs 32a delimit the region of the isolating region iSa, which is provided as an interface l4a for attaching the additional handle ba. The hand tool machine l2a takes the form of a drilling harnrrier, which has a hand tool machine protective housing 26a. A front part of the hand tool machine protective housing 26a is formed by a protective hood 36a that is formed integrally with the hand tool machine isolating unit. The hand tool machine isolating unit is configured as part of the hand tool machine protective housing 25a.

The hand tool machine isolating unit of the protective hood 36a surrounds a percussion mechanism housing 38a (Figure 2) and is supported in the. region of the support region l6a thereon. The additional handle lOa is fastened by a clamping band 40a in the region of the interface 14a situated between the two webs 32a. The clamping band 40a is clamped by means of a clamping device 42a that is integrated into the additional handle lOa. The isolating region iSa has in its edge regions transition zones 44a that adjoin the support region l6a. The isolating region iSa has a different wall thickness from the support region 16a. In particular, the transition zone 44a comprises a plurality of regions of reduced wall thickness, with the result that it has an increased flexibility. These transition zones 44a offer high resistance to axial forces that extend in the direction of a percussion axis 34a of the hand tool machine 12a and to rotatory forces that extend around the percussion axis 34a. The resistance to a tilting of the additional handle iOa in the direction of the percussion axis 34a is much lower. By virtue of a large distance of a gripping piece GOa of the additional handle iOa from the isolating region iSa, only small tilt angles 45a that still lie within the durable and/or elastic range of the material are required for effective vibration reduction. If the tilt angle 45a becomes greater, the inner wall of the isolating region lBa is supported on the percussion mechanism housing 38a, and the tilting movement is restricted.

The following descriptions and the drawings of further embodiments are confined substantially to the differences between the embodiments, wherein with regard to identically designated components, in particular with regard to components having identical reference characters, reference may in principle also be made to the drawings and/or the description of the other embodiments, in particular of Figures 1 and 2. In order to differentiate between the embodiments, instead of the letter a of the first embodiment the letters b -f have been placed after the reference characters of the embodiments.

In Figure 3 a further form of an isolating region 18b is represented in a detail view. The isolating region l8b is connected at one end by a film hinge 20b to a support region l6b. At an end remote from the film hinge 2Gb the isolating region l8b is supported via a supporting element 46b on a percussion mechanism housing 38b. The supporting element 46b is manufactured from an elastomer. The supporting element 4Gb in particular takes up tilting movements by a tilt angle 48b, while the film hinge 2Gb blocks axial-and further rotatory movements.

In Figure 4 and Figure 5 a further form of an isolating region l8c is represented. The isolating region l8c contains a support element 22c that stiffens the isolating region 18c. The support element 22c takes the form of a sheet metal part made of spring steel, which is integrally connected to the hand tool machine isolating unit. The support element 22c takes up in particular forces of a clamping band 40c, by means of which an additional handle lOc is fastened. The support element 22c also serves as a stop unit 24c in that it is supported on a percussion mechanism housing 38c if the isolating region lBc is extremely deformed. The stop unit 24c therefore prevents an inadmissibly extreme deformation.

In Figure 6 and Figure 7 two further embodiments of an isolating region i8d and l8e are represented. A support region l6d and i6e and the isolating region l8d and 18e are formed partially from materials of differing stiffness. In the example of Figure 6 the isolating region 18d is manufactured from a thermoplastic elastomer, while the support region 16d is manufactured from a stiffer plastics material. The isolating region l8d is integrally injection-moulded onto the support region l6d. In addition, the isolating region l8d has an additional support element 22d. The support element 22d simultaneously forms a stop unit 24d, which is provided for restricting a movement of the isolating region l8d relative to the support region 16d.

In the embodiment of Figure 7 a transition zone 44e of the isolating region 18e is manufactured from a thermoplastic elastomer, while the remaining isolating region 18e and the support region 16e are manufactured from a stiffer plastics material. The transition zone 44e is formed integrally with the isolating region iSe and connected integrally to the support region 16e. As only the transition zones 44e of the isolating region iSe are manufactured from an elastic material and the remaining isolating region l8e, in particular the region of an interface 14e, is formed from a stiffer plastics material, it is possible to dispense with an additional support element. The hand tool machine isolating unit is again manufactured integrally in a multi-component injection moulding process.

Figure 8 and Figure 9 show a further embodiment of a hand tool machine isolating unit. The hand tool machine isolating unit takes the form of an annular isolating module 50f comprising a support region l6f and at least one isolating region l8f that is provided for being coupled to a fully.funct.ional handtooi machine l.2f.. The isolating module 50f has a coupling region 28f that is provided for coupling to a hand tool machine housing 30f. In the embodiment the isolating module SOf is glued to a percussion mechanism housing 38f that partially radially surrounds the isolating module 50f. The additional handle lOf, as in the previous examples, is fastened by a clamping band 40f to the isolating module 50f. The isolating module 50f is manufactured in one piece from plastics material.

However, one-piece and/or multi-piece constructions of various materials are also conceivable. The isolating module 50f has two cylindrical regions 52f, which are connected by a central radial web 54f. The web 54f in particular with high rigidity takes up the force that arises as a result of fastening the additional handle lOf by means of the clamping band 40f. In the event of tilting of the cylindrical regions 52f by a tilt angle 4Sf, the web 54f is elastically deformed. The isolating module SOf therefore in radial, tangential direction and in longitudinal direction of a percussion axis 34f has a greater stiffness than in the event of tilting by a tilt angle 48f about a transverse axis. As a result of the leverages, a small tilt angle 4Sf already gives rise to a large movement at the additional handle lOf. These tilting movements contribute substantially to the vibration isolation. Two intermediate spaces 56f between the two cylindrical regions 52f may be filled with an elastomer 58f so that the isolating module 50f may exert greater restoring forces and the elastic behaviour is improved.

The isolating module SOf with embedded elastomer may be manufactured in one piece in a multi-component injection moulding process.

Claims

Claims 1. A hand tool machine isolating unit for isolating an additional handle for a hand tool machine from hand tool machine vibrations, comprising at least one interface for attaching the additional handle, at least one support region and at least one isolating region, characterized in that the support region and the isolating region are of an integral construction.
2. The hand tooirna*chine isolating unit.according to claim 1, characterized in that the isolating region has a different wall thickness from the support region.
3. The hand tool machine isolating unit according to claim 1 or 2, characterized in that the isolating region comprises at least one film hinge.
4. The hand tool machine isolating unit according to one of the preceding claims, characterized by at least one additional support element.
5. The hand tool machine isolating unit according to one of the preceding claims, characterized in that the support region and the isolating region are formed at least partially from materials of differing stiffness.
6. The hand tool machine isolating unit according to one of the preceding claims, characterized by at least one stop unit that is provided for restricting a movement of the isolating region relative to the support region. a)
7. The hand tool machine isolating unit according to one of the preceding claims, characterized by the at least partial configuration as a, hand tool machine protective housing.
8. The hand tool machine isolating unit according to the preamble of claim 1 and in particular according to one of claims I to 6, characterized by at least one coupling region that is provided for coupling to a hand tool machine housing.
9. A hand tool machine having a hand tool machine isolating unit according to one of the preceding claims.
10. An additional handle having a hand tool machine isolating unit according to one of claims 1 -8.
11. The hand tool machine isolating unit substantially as herein described with reference to the accompanying drawings.
12. The hand tool machine substantially as herein described with reference to the accompanying drawings.
13. The additional handle substantially as herein described with reference to the accompanying drawings.