AU2004231219A1

AU2004231219A1 - Switch having lockable operating rocker

Info

Publication number: AU2004231219A1
Application number: AU2004231219A
Authority: AU
Inventors: Horst Biersack
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: PT1533820E; EP1533820B1; NZ536713A; EP1533820A1; ES2268563T3; AU2004231219B2; DE502004000873D1; ATE332011T1; DE10355102B3; KR20050050034A

Abstract

An operating rocker button on a bearing end slides lengthwise in oblong holes (9) against a restoring spring (10). After a lengthwise slide, a hook (13) locks into a transverse pin (14) from behind in a pressed operating position. The rocker button is released again by a subsequent automatic longitudinal movement.

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: Switch having lockable operating rocker The following statement is a full description of this invention, including the best method of performing it known to me/us:- The invention is directed to a hand held electric tool, preferably a percussion tool, having a switch arranged in the grip handle which switch is preferably steplessly adjustable via an operating rocker, with the operating rocker being releasably lockable in an operating position.

It is desirable, especially in respect of electric percussion tools, that the operator is not required to simultaneously push the operating rocker whilst firmly pressing the tool against a work surface, such as a wall or the like, but that the same is locked in an operating position thereby facilitating a significantly easier handling during application of the tool in a work process.

A variety of different arrangements have already been proposed for this purpose, for instance double rockers, special interlocking switches for locking and unlocking the rocker etc. All these have the disadvantage that they have a relatively complex configuration and/or that they cannot easily be actuated with one hand whilst operating the tool at the same time.

It is the object of the present invention to design an electric percussion tool with a lockable operating rocker for an operating switch in such a manner that a simple configuration will allow an easy one-handed operation by the operator actuating the rocker whilst at the same time preventing an accidental release of the rocker depressed in the locked position.

The solution to this problem is provided by the invention in that the operating rocker is positioned at the mounting end longitudinally displaceably in elongated holes against a return spring and is provided with a hook which, subsequent to the longitudinal displacement in the depressed operating position, lockingly engages, from behind, a cross-pin of the housing, with the locking arrangement being designed such that it can only be unlocked by a relatively great pressure force O preventing an unintentional release when the rocker is touched and the rocker is again releasable by subsequent automatic longitudinal displacement.

O

Z

C By virtue of the arrangement in accordance with the invention, a locking of the operating rocker requires merely a longitudinal displacement which is very easily achievable by a sliding movement performed by the operator's hand or index finger of the operator's hand against a relatively small elastic force of the return spring in order to achieve subsequently, when letting go, that a rocker spring, against which the rocker operates for the purpose of a stepless adjustment of the switch position, pushes back the rocker resulting in the hook snapping in place behind the cross pin.

The locked operating position therefore does not fully correspond with the maximum possible depressed position of the rocker and the thereby resulting maximum displacement position of the switch.

In order to be able to perform this displacement of the operating rocker in its longitudinal direction simultaneously with the depression into the operating position and to prevent the operator's hand from slipping off, the operating rocker can be provided with a profiling, in particular a protruding end projection for the purpose of pulling the rocker into the locking position.

It is an essential aspect of the operating rocker in accordance with the invention that it is designed such that it cannot simply be unlocked accidentally by touching but that for this purpose a considerable pressure force must be applied. In accordance with a further embodiment of the invention this can simply be achieved in that the hook is provided with an incline which bears against the cross pin upon depression of the rocker, with the incline being adjusted such that the elastic force of the return spring in conjunction with the force of the rocker spring produces the desired pressure force being the required release force.

During this releasing pressure being applied in the locked position, the rocker must of course initially be displaced in the longitudinal direction against the return spring, whereupon, depending on the angle of inclination of the hook, different forces must be applied to overcome the return spring force. It is therefore possible by selecting a respective angle of inclination to determine the required force to release the rocker from the locked position; in addition there is of course also the relatively smaller force of the rocker spring.

Further advantages, features and details of the invention are described below by reference to an embodiment example and the drawings.

Shown are in: Fig. 1 Fig. 2 Fig. 3 a side view of the grip handle of a handheld electric tool with the operating rocker being in the outwardly swung untensioned position.

a view of the arrangement according to Fig. 1, with the operating rocker swung fully inwardly.

a view where the operating rocker in the inwardly swung position according to Fig. 2 is additionally displaced upwardly against the return spring by the operator's hand.

the locked operating position into which the rocker has been placed after the operator's hand has let go subsequent to having set the position according to Fig. 3.

enlarged details of the rocker end with the locking hook in the locked operating position in one view and, in the other view, upon commencement of the release prior to unlocking.

Fig. 4 Fig. and 6 The grip handle 1 composed of two semi-shells, where the shells are connected by screws at 2 and 3, has a steplessly variable switch 4 which is actuatable by an operating pin 5 (shown by dashed lines) which is adjustable by means of an operating rocker 7 which is overhung-mounted by means of a bearing shaft 6. The details of the design of this operating pin and the manner in which it is actuated by the rocker will not be discussed in this specification, because these are sufficiently O known in respect of such operating rockers and switch configurations and do not represent an object of the present invention.

O

The bearing shaft 6 of the operating rocker 7 is positioned in elongated holes 9 of the shells la and lb which are not detailed in the drawings and are located above and below the recesses 8 of the switch. The bearing shaft 6 is fastened by a return spring into the downwardly pulled position shown in Fig. 1. The element 11, together with a limit stop within the operating rocker 7, form a swing-out-limit for this rocker holding it in the untensioned position shown in Fig. 1. The rocker is urged by a rocker spring 12 into this outward position. A hook 13 is integrally formed with the top of rocker 7, which hook, when the rocker is pushed inwardly, is capable of passing below a cross pin 14 which passes through the grip handle.

As long as no pull is applied to the rocker in the direction of arrow 15 as per Fig. 1 such a pull by the operator's hand is facilitated by the projection 16 the hook 13 always passes below the cross pin upon pivoting of the rocker inwardly as well as outwardly.

If it is intended to lock the operating rocker in a depressed, operating position, so that during percussive work processes the rocker does not need to be constantly pushed, but the operator can concentrate on pressing the tool against the work surface, the operator moves the rocker into the most inwardly displaced position according to Fig. 2 by pushing it inwardly. Immediately following this, the operator's hand pushing the rocker inwardly will displace the rocker slightly upwardly in its longitudinal direction against the return spring 10 so that it reaches the position according to Fig. 3. If the operator then lets go of the rocker, the hook 13 engages the cross pin and snaps into place behind the cross pin, in which process the hook is being urged by the rocker spring 12 into the position shown in enlarged view in Fig. There is an incline 16 integrally formed with the rocker hook 13 which in the locked position in accordance with Figs. 4 and 5 is only located at a distance of a fraction of a millimetre from cross pin 14 so that, when the rocker is pushed, the cross pin 14 practically immediately bears against this incline 16. To release the operating rocker from the operating position according to Figs. 4 and 5, the rocker must initially again be moved upwardly against the action of the return spring 10, so that the cross pin can pass from under the hook or rather the hook can slide over the fixed cross pin.

0 The inclination of the incline 16 and the force KR of the return spring 10 result in the Srelease force for unlocking the operating rocker.

This release force should be relatively great, thus preventing an accidental release when the operating rocker is being touched. The operating rocker should only be unlocked by an intentionally applied relatively great release force.

The reference numerals in the following claims do not in Sany 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 tool, preferably a percussion tool, having a switch arranged in the grip handle, which switch is preferably steplessly adjustable via an operating rocker, with the operating rocker being releasably lockable in an operating position, Scharacterised in that the operating rocker is positioned at the mounting end M€3 longitudinally displaceably in elongated holes against a return spring (10) and is provided with a hook (13) which, subsequent to the longitudinal displacement in the depressed operating position, lockingly engages, from behind, a cross-pin (14) of the grip handle with the locking arrangement being designed such that it can only be unlocked by a relatively great pressure force preventing an unintentional release when the rocker is touched and the rocker is again releasable by subsequent automatic longitudinal displacement.

2. The electric tool in accordance with Claim 1, characterised in that the hook (13) is provided with an incline (16) which bears against the cross pin (14) upon depression of the rocker with the incline being adjusted such that in conjunction with the elastic force of the return spring (10) the desired pressure force being the required release force is obtained.

3. The electric tool in accordance with Claim 1 or 2, characterised in that the rocker (7) is provided with a profiling, in particular a protruding end projection (16) for the purpose of pulling the rocker into the locking position.

4. A tool substantially as hereinbefore described with reference to the drawings and/or Examples. 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