NZ536712A

NZ536712A - Vibration dampened grip handle

Info

Publication number: NZ536712A
Application number: NZ536712A
Authority: NZ
Inventors: Horst Biersack; Joachim Gobel
Original assignee: Itw Befestigungssysteme
Priority date: 2003-11-24
Filing date: 2004-11-22
Publication date: 2006-04-28
Also published as: ES2293144T3; EP1533084B1; KR101159223B1; AU2004231220B2; DE10355103B4; DE502004005008D1; DE10355103A1; EP1533084A1; KR20050050033A; ATE373546T1; AU2004231220A1

Abstract

A handheld electric percussion tool, in particular a pneumatic hammer drill, having a tool housing and a vibration dampened grip handle, wherein limbs of a substantially C- shaped grip handle are fastened at the tool housing with spring elements arranged there between, characterised in that at one end, preferably the lower end of the tool housing, the grip handle is pivotally mounted about a transverse bearing 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 there between.

Description

<div class="application article clearfix" id="description"> 536 7 J NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION After United States Patent Application No. 103 55 103.4-15 filed on 24 November 2003 Davies Collison Cave Reference: 12538280 APPLICANT(S) ITW Befestigungssysteme GmbH Gutenbergstrasse 4, D-91522 Ansbach, Germany My/Our contact address is: DAVIES COLLISON CAVE 1 Nicholson Street G.P.O. Box 4387QQ Melbourne 3000 Victoria, AUSTRALIA Telephone: 61 3 9254 2777 Facsimile 61 3 9254 2770 Email: [email protected] INVENTION TITLE: My/Our address for service is: DAVIES COLLISON CAVE c/- James & Wells Level 9, James & Wells Tower 56 Cawley Street Private Bag 11907 DX CP 34005 Ellerslie Auckland NEW ZEALAND Vibration dampened grip handle We/I, ITW Befestigungssysteme GmbH hereby declare the invention for which we pray that a patent be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: P:\REC\JMF\14437.doc- 19/11/04 INTELLECTUAL PROPERTY OFFICE OF N.Z. 22 IIOV 222h received Vibration Dampened Grip Handle 5 The invention relates to 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. 10 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 A1 and WO 02/083369 Al. A vibration dampened grip handle having a gasfilled 15 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 20 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 25 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 30 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 2 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 therebetween, where preferably the bearing axis is also wrapped in damping material. 5 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. 10 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 15 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. 20 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 25 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 30 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 3 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 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 5 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 to the second bearing shell half for the bearing axis of the grip handle, the assembly is already completed. 10 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. 15 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. 20 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. 25 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 30 Fig. 1 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; 4 Fig. 3 an enlarged partially opened view of the grip part and the adjacent part of the tool housing; 5 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. 5. 10 The handheld electric percussion tool shown in the figures comprises a tool housing 1 with a bottom part 1 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 15 housing 1 and its bottom part 1 a 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 20 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 25 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 30 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. 5 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 of latching hook means 8 are inserted into the lower sections 7a of the openings 7 of the metal plate 6. Subsequently, the grip handle is pulled downwardly, which then 5 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 narrower region 7b of the openings 7, where they are captured behind the metal plate 6. Subsequently, the housing bottom part la is attached at the lower end and fastened 10 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 15 the metal plate 6 which is necessary for the vibration dampened connection of the grip handle 2 with the tool housing 1. P:\OPER\JPN\12538280 1spa.doc-23/09/05 -6- </div>

Claims

<div class="application article clearfix printTableText" id="claims"> Claims

1. A handheld electric percussion tool, in particular a pneumatic hammer drill, having a tool housing and a vibration dampened grip handle, wherein limbs of a substantially C-shaped grip handle are fastened at the tool housing with spring elements arranged 5 therebetween, characterised in that at one end, preferably the lower end of the tool housing, the grip handle is pivotally mounted about a transverse bearing 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 therebetween.

2. The electric tool in accordance with claim 1 characterised in that the bearing axis is 10 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 of the housing and a housing bottom part 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 and whose hook ends engage the 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.

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

6. The electric tool in accordance with any one of claims 1 to 5, characterised in that the dampening cushion is divided in the longitudinal direction and composed of several 25 sections of homogeneous or different damping materials. \PONZ 28 2005 P:\QPER\JPN\I2538280 lspa.doc-23/09A)5 -7-

7. The electric tool in accordance with claim 6, characterised in that for generating an energy-destroying friction, the dampening cushion envelopes 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 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 is provided bridging the dampened connection of the housing and the upper grip handle limb. IPONZ 28 SEP 2005 </div>