AU2004231220A1

AU2004231220A1 - Vibration dampened grip handle

Info

Publication number: AU2004231220A1
Application number: AU2004231220A
Authority: AU
Inventors: Horst Biersack; Joachim Gobel
Original assignee: ITW Befestigungssysteme GmbH
Current assignee: ITW Befestigungssysteme GmbH
Priority date: 2003-11-24
Filing date: 2004-11-19
Publication date: 2005-06-09
Anticipated expiration: 2024-11-19
Also published as: KR20050050033A; EP1533084A1; DE10355103A1; EP1533084B1; NZ536712A; DE502004005008D1; ES2293144T3; KR101159223B1; AU2004231220B2; ATE373546T1; DE10355103B4

Abstract

The c-shaped handle (2) can be swiveled around an axle located at the lower segment (2a) in order to insert a vibration absorbing rubber element (11) assembled of a front and a rear segment (11a, 11b) which can be of different levels of rigidity. A flat metal part (6) with hook shaped ends (8, 9) is accommodated inside the rubber elements (11a, 11b) and is stationary joined to the housing (1) of the tool. The hooks (8, 9) engage with matching spaces located at the upper handle segment (2b) when the handle (2) is swiveled into a position ready for use.

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION NAME OF APPLICANT(S):: ITW Befestigungssysteme GmbH ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Nicholson Street, Melbourne, 3000, Australia INVENTION TITLE: Vibration dampened grip handle The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5102 0 z The invention relates to a handheld electric percussion tool, in particular a pneumatic O hammer drill with vibration dampened grip handle, wherein the limbs of a substantially C-shaped grip handle are fastened at the tool housing with spring elements arranged therebetween.

Such vibration-dampened grip handles for handheld electric percussion tools have already become known in a variety of designs. Where spiral springs are used, it is necessary to separately guide the grip handle so that it does not sideslip; this results in quite expensive constructions as they are described for instance in DE 101 36 015 Al and WO 02/083369 Al. A vibration dampened grip handle having a gasfilled cushion as the vibration dampening element disclosed in WO 02/38341 Al shows the problem encountered, namely that, upon the occurrence of stronger vibrations, components of the grip handle and the grip are likely to make direct contact resulting in increased noise. Furthermore, a gasfilled cushion has the disadvantage that longterm use presents the risk of leakiness so that the vibration dampening function is no longer achieved.

A construction in accordance with WO 03/043785 Al, where between a grip part and a fastening part there is arranged an elastic element at the housing of the hand tool, requires an additional movable securing element; however in this construction difficulties will still arise where large impact loads and strong vibrations are present.

It is the object of the present invention to propose a design for a handheld electric percussion tool of the type mentioned at the outset which, by a simple configuration and an easy assembly, results in an excellent and additionally sound-absorbing vibration dampening, wherein the damping level is adjustable by simply exchanging a dampening element.

The invention provides a solution to this problem in that at one end, preferably the lower end of the tool housing, the grip handle is pivotally mounted about a transverse axis, and at the other end has a plug-in connection with the tool housing and is latched in place with a dampening cushion of rubber or pulp foam arranged 0 therebetween, where preferably the bearing axis is also wrapped in damping material.

By virtue of the arrangement in accordance with the invention an extremely simple constructional design is achieved wherein the mounting of the lower limb of the grip handle at the tool housing achieves excellent side guiding so that a lateral tipping of the vibration dampened grip handle is not likely to occur.

The pivotally mounted arrangement can be achieved particularly easily in a further development of the invention in that the bearing axis of the grip handle provided with dampening rings placed thereon is mounted in divided bearing shells of the housing and a housing bottom part separately attached thereto. Following the insertion of the grip handle and in order to achieve the plug-in latched connection at the upper end, the grip handle is simply swung into the bearing shell of the housing at the lower end and subsequently, by means of the housing bottom part fastened thereto, preferably by way of screwing, is pivotally mounted in a circumferential bearing shell.

It is of particular advantage if, at the upper part of the tool housing, there is fastened a rigid latching hook means, preferably embodied as a plate, which passes through the dampening cushion and whose hook ends engage openings of a metal plate at the upper limb of the grip handle which openings are narrower at the top than at the lower insertion regions, with the dimensioning being selected such that in the installation position the hooks resiliently bear against the back of the metal plate in the narrowed upper position.

In order to prevent that vibration movements cause the hooks to strike against the metal plate thereby producing noise, a further embodiment of the invention provides for the back of the metal plate to be covered with an elastic damping layer.

The grip handle design described above allows for a very easy assembly in that the grip handle is initially attached at the top at the latching hook means and subsequently pulled slightly downwardly so that the bearing axis with the elastic O dampening rings can be snapped into place into the bearing shell of the housing.

>-Following the pulling down action to achieve the snapping into place of the bearing 0 z shaft into the bearing shell of the housing at the lower end, there results a displacement of the.latching hook means into the upper region of the openings in the metal plate which are appropriately tapered so that an escape of the hooks at this point is not possible. By plugging or preferably screwing of the housing bottom part Nto the second bearing shell half for the bearing axis of the grip handle, the assembly is already completed.

In accordance with a further feature of the present invention, it is proposed that the dampening cushion be divided in the longitudinal direction and composed of several sections of homogeneous or different damping materials, whereby by virtue of an appropriate combination of different sections almost any desired damping characteristic can be achieved in the simplest manner.

Preferably, for the purpose of generating an energy-destroying friction, the dampening cushion shall envelop the latching hook means in a tight fitting manner, which will result in an additional improvement of the vibration damping.

In a simple manner, the grip handle can be composed of two semi-shells which are screwed together in the region below the metal plate as well as in the hollow bearing axis, in which aspect it is finally still within the scope of the invention to provide a sealing element bridging the dampened connection of the housing and the upper grip handle limb.

Further advantages, features and details of the invention are described in the following description of an embodiment example by reference to the drawing.

Shown are in Fig. I an exploded perspective view of the essential parts of a handheld Electric percussion tool with a vibration dampened grip handle; Fig. 2 an enlarged perspective sectional drawing of the upper end of the tool housing; Fig. 3 an enlarged partially opened view of the grip part and the adjacent part 0 of the tool housing; z Fig. 4 to 6 various views of the grip handle of the configuration in accordance with the invention and Fig. 7 an enlarged section VII as shown in Fig. S 10 The handheld electric percussion tool shown in the figures comprises a tool housing 1 with a bottom part l a which is separately attached, preferably screwed thereto and an easily plugged-in vibration dampened grip handle 2. This vibration dampened grip handle 2 is provided with a bearing axis 3 which, surrounded by dampening rings 4, is mounted in bearing shells 5a and 5b which are integrally formed with the tool housing 1 and its bottom part la respectively. At the upper limb 2b of the grip handle 2 there is arranged a metal plate 6 with openings 7 for the insertion of a latching hook means 8 which is rigidly attached to the tool housing 1, with the openings 7 being wider in the lower region 7a than in the upper region 7b in such a manner that the hook ends 9 of the latching hook means 8 can be inserted into the lower region whilst they are captured behind the plate 6 upon displacement into the upper region 7b. A stop plate 10 is rigidly fastened on the latching hook means 8 with the stop plate 10 supporting a dampening cushion 11 consisting of two sections 1 la and 1 lb in the embodiment example shown. Upon insertion of the latching hook means 8 into the opening 7 of plate 6, this dampening cushion must be compressed so that the hooks, with an elastic force, bear against the back of the metal plate 6 covered with a dampening layer 12.

By virtue of the design of the dampening cushion 11 consisting of several sections which, if so desired may consist of different materials, i.e. different rubbers or different pulp foams, there is a wide scope for selecting the damping characteristic for the grip handle 2. Ref. 13 shows a sealing element which protectively envelopes the junction of the upper limb 2b of the grip handle with the housing 1.

During assembly, the upper limb 2b of the grip handle 2 is initially connected with the latching hook means 8, in which arrangement, for this purpose, the hook ends 9 z of latching hook means 8 are inserted into the lower sections 7a of the openings 7 of Sthe metal plate 6. Subsequently, the grip handle is pulled downwardly, which then offers the option of forcing the bearing axes 3 with the dampening rings 4 surrounding them into the bearing shells 5a of the housing. Subsequently the grip handle 2 is again displaced upwardly thereby moving the hook ends into the upper CC narrower region 7b of the openings 7, where they are captured behind the metal plate 6. Subsequently; the housing bottom part I a is attached at the lower end and fastened with a screw.

The grip handle 2 is composed of two shell halves which are attached via screw connections in the region of the bearing axis 3 and of the sleeves 14 integrally formed with the shell halves. This two-shell structure facilitates an easy insertion of the metal plate 6 which is necessary for the vibration dampened connection of the grip handle 2 with the tool housing 1.

The reference numerals in the following claims do not in any way limit the scope of the respective claims.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Claims

1. A handheld electric percussion tool, in particular a pneumatic hammer drill, with vibration dampened grip handle, wherein the limbs of a substantially C-shaped grip handle are fastened at the tool housing with spring elements arranged therebetween, (characterised in that at one end, preferably the lower end of the tool housing the S~ grip handle is pivotally mounted about a transverse axis, and at the other end has a I plug-in connection with the tool housing and is latched in place with a dampening cushion of rubber or pulp foam arranged therebetween.

2. The electric tool in accordance with claim 1 characterised in that the bearing axis is wrapped in damping material.

3. The electric tool in accordance with claim 1 or 2, characterised in that the bearing axis of the grip handle provided with dampening rings placed thereon is mounted in divided bearing shells (5a, 5b) of the housing and a housing bottom part (I a) separately attached thereto.

4. The electric tool in accordance with any one of claims 1 to 3, characterised in that at the upper part of the tool housing there is fastened a rigid latching hook means preferably embodied as a plate, which passes through the dampening cushion (11) and whose hook ends engage the openings of a metal plate at the upper limb (2b) of the grip handle which openings are narrower at the top than at the lower insertion regions, with the dimensioning being selected such that in the installation position the hooks resiliently bear against the back of the metal plate in the narrowed upper position.

5. The electric tool in accordance with claim 4, characterised in that the back of the metal plate is covered with an elastic dampening layer (12).

6. The electric tool in accordance with any one of claims I to 5, characterised in that the dampening cushion (11) is divided in the longitudinal direction and composed of Sseveral sections (1 la, 1 Ib) of homogeneous or different damping materials.

7. The electric tool in accordance with claim 6, characterised in that for generating an energy-destroying friction, the dampening cushion (11) envelops the latching hook means in a tight fitting manner.

8. The electric tool in accordance with any one of claims 1 to 7, characterised in that the S) grip handle is composed of two semi-shells which are screwed together in the region below the metal plate as well as in the hollow bearing axis

9. The electric tool in accordance with any one of claims 1 to 8, characterised in that a sealing element (13) is provided bridging the dampened connection of the housing (1) and the upper grip handle limb (2b). A percussion tool substantially as hereinbefore described with reference to the drawings and/or Examples.

11. The steps, features, compositions and compounds disclosed herein or referred to or indicated in the specification and/or claims of this application, individually or collectively, and any and all combinations of any two or more of said steps or features. DATED this NINETEENTH day of NOVEMBER 2004 ITW Befestigungssysteme GmbH by DAVIES COLLISON CAVE Patent Attorneys for the applicant(s) 5108