AU2004231227B2

AU2004231227B2 - Rotary selector switch

Info

Publication number: AU2004231227B2
Application number: AU2004231227A
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: 2008-06-05
Anticipated expiration: 2024-11-19
Also published as: EP1533083A2; DE10355107B3; EP1533083A3; AU2004231227A1; ATE387990T1; EP1533083B1; DE502004006396D1; DK1533083T3; KR20050050035A; ES2301914T3; NZ536711A

Abstract

A pipe section (5) can be axially moved along the outer surface of a cylinder (4) causing one of the toothed inner surfaces (10) positioned at both of its ends to engage with the outer teeth located at one of two function selecting rings (8, 9). The mechanism is activated by rotating a button (12) acting on an eccentrically positioned pin carrying a swash plate on a cam (13) at its upper end. The plate is pressed down by a helical spring released by a slight rotation of the button (12) and causing the pin to move along a curved slot.

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: Rotary selector switch The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5102 P:\OPER\TLG\l2538300 I spa do-28V4200 00 la- The invention relates to a rotary selector switch for selecting the different ,I operating functions (drilling-intermediate position-cutting) in a handheld electric tool with an axially displaceable contact tube for the purpose of selecting the operating functions, with the contact tube having transverse profiles to mesh with 5 mating profiles and a circumferential groove which is engaged by an operating Cc cam which is disposed in a plane extending from the rotary switch parallel to the longitudinal axis of the tool and which is rotatable about the switch axis extending transverse to this longitudinal axis. The profiles can for instance be spur gears.

When actuating such a rotary selector switch, the problem may arise that the teeth of the spur gears of the contact tube are placed opposite those of the mating profile and thus cannot reach an engagement position so that the switching from the groove position into the position "cutting" or into the position "drilling" is not possible in this case. The operator may then be forced by turning switches at the tool and to achieve by simultaneous multiple actuating of the rotary selector switch that the transverse profile can engage with the respective mating profile.

This is laborious and cumbersome.

It is desirable to provide a selector rotary switch of the type mentioned at the outset in such a manner that in each case preselection of the desired operating function is possible by turning the switch in such a manner that as soon as the teeth of the transverse profile and the mating profile are able to mesh together, the respective axial displacement is performed and therefore the desired operating function is set.

According to the present invention, there is provided a rotary selector switch for selecting the various operating functions (drilling/intermediate position/chiselling) in a portable electric tool comprising an axially displaceable control tube serving to select the operating functions and having end profiles for engaging in corresponding mating profiles and having a circumferential groove in which a control cam engages, which can be rotated by the rotary switch about the switch P\OPERTLG\l 2538300 Is doc-28D4/20 00 -lb-

C

axis in a plane running parallel to the longitudinal axis of the tool, said switch axis running transversely to said longitudinal axis, the control cam being mounted on the rotary switch in such a way as to be pivotable in its path of movement on both sides against a spring force, wherein the control cam is arranged on the end of a C 5 control pin which is parallel to the switch axis and is coupled in such a way as to n be pivotable against a preloading spring about its foot point connected to the rotary switch in a rotationally fixed manner.

0 In a preferred embodiment of the invention, an operating cam may be mounted at the rotary switch so as to be pivotally movable in its path of motion on both sides against an elastic force.

C, By virtue of the design in accordance with the invention, actuation of the rotary o selector switch in a position in which the profile cannot engage the mating profile a position therefore in which the corresponding displacement of the contact tube is not possible allovws the operating cam during the turning of the rotary selector switch to be deflected against the biasing spring, whereby the contact tube is biased into the couplinig position by the respective elastic force of the restoring spring of the operating cam: as soon as the teeth are moved out of their

(N)

superimposed position, thus allowing the profiles to mesh, the displacement of the contact tube and the c6upling of transverse profile and mating profile are achieved (N 10 by this elastic force.

In this situation it is obviously irrelevant whether the transverse profiles and mating profiles are defined by meshing bevel gears or toothed gears where one has internal toothing and the other external toothing meshing together upon axial displacement, or whether they consist of some other type of profile. What is decisive is that the profiles are meshing profiles which always run the risk that when misalignment occurs the teeth are superimposed thus preventing coupling.

In a further development of the invention it is proposed that the operating cam is i arranged at the end of an operating pin disposed parallel to the switch axis with the operating pin being biased by a pretensioned spring and pivotally hinged about its base which has a torsionally stiff connection with the rotary switch.

This results in a kind of tumbling movement of the operating pin with the 1 operating cam being disposed at its free end and for this reason preferably provided with a convex annular section to engage the circumferential groove of the contact tube.

To achieve this tumbling movement of the operating pin it is proposed by an embodiment of the invention that the operating pin be eccentrically rigidly fastened on a wobble plate which is mounted in a torsionally stiff manner in the switch casing on mutually opposite support elements, centrally between the

I

Ssupport points, which' wobble plate being impinged upon from above by a 0 compression spring is optionally tiltable about the support elements.

Z

To achieve a torsionally stiff conlnection it is proposed in a very simple manner that the wobble plate be provided with mutually opposite slots which are engaged C- by the guide elements at the inner wall of the switch casing, which guide elements are flanked by two support elements.

ec- O By virtue of this simple design of a wobble plate it is achieved that, upon turning C 10 the rotary selector switch, with the selector transverse profile for the operating function in the blocked position where the contact tube is axially blocked after all and the operating camn therefore cannot follow the axially disposed component for the rotation of the selector rotary switch but is retained in the circumferential groove of the contact tube the wobble plate is deflected by the operating pin I such that it lifts off at lone support end against the action of the compression spring. As soon as the tooth profiles of the function selection gear are able to mesh, this compression spring causes the return of the wobble plate into its starting position and therefore the displacement of the contact tube into the preselected position.

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

Shown are in: Fig. 1 a perspective detail drawing ofa handheld electric tool with the essential gear components for the operating functions drilling and cutting and a selector rotary switch in accordance with the invention which facilitates the switching between these operating functions; Fig. 2 an exploded perspective drawing of the components of the selector rotary swvitch; Fig. 3 an enlarged cut through the selector rotary switch; 0 Fig. 4 a sectional detail view of the wobble and tilting option of the operating pin and Fig. 5 an enlarged top view of the front face of the selector rotary switch with the protruding operating cam.

C€3 Fig. 1 shows the driven bevel gear 1 of the electromotor gearing of an electric tool 10 in engagement with the bevel gear 3 which, on the other hand, is freely rotatably mounted on the cylinder 4 which, at its front end (shown on the left in Fig. 1) is connected to a drill. By means of axial grooves and ribs, a contact tube 5 is mounted in a torsionally stiff manner but axially displaceably on cylinder 4, which contact tube 5 is provided at its front end with a spur gear 6 having external toothing which, upon a corresponding axial displacement, can mesh together with the internal toothing of a mating toothed gear, namely the connector ring 8 rigidly mounted in the casing At the other end, the contact tube 5 is provided with a spur gear 9 having internal toothing 10 which can mesh with the external toothing of a mating toothed gear 11 which is permanently connected to the bevel gear 3.

If via the selector rotary switch 12 having an eccentric operating cam 13, which engages an annular groove 14 between two fixed rings 15 and 16 of the contact tube, the contact tube is displaced towards the right, the bevel gear is placed in a torsionally stiff connection with the cylinder 4 via the coupled toothed gears 9 and 11, via the contact tube 5 having a torsionally stiff connection with the cylinder 4, so that the motor gearinig 2 has a rotary connection with the cylinder and therefore with the drill. Therefore, this particular setting is the operating function "drilling".

If conversely, the contact tube 5 with the aid of the selector rotary switch 12 having been turned by 90 degrees beyond the OFF position in the opposite direction is displaced to the left, the spur gear 6 is coupled to the connector ring 8 Swhich is fixed within the housing. The contact tube 5 is thereby blocked in the direction of rotation so that in this position only "cutting" can be performed.

o In accordance with the invention, the rotary selector switch 12 is designed such Z that a preselection of the functions drilling or cutting is also possible if the actually required displacement of the contact tube 5 is blocked due to the teeth of the meshing spur gears being in superimposed position.

For this purpose, a wobble plate 19 is mounted in a torsionally stiff position in the C€3 switch casing, with the wobble plate 19 supporting an eccentric operating pin 17 being fitted at its end with a convex operating cam 13, in which arrangement the C 10 torsionally stiff seating is achieved in that the wobble plate is provided with at least two mutually opposite slots 20 (in the illustrated embodiment example several slot pairs are provided) which are engaged by two mutually opposite guide elements 21 at the inner wall of the switch casing 22. These guide elements 21 are flanked on both sides by support elements 23, on which the wobble plate 19 rests, in which arrangement the operating pin 17 with its operating cam is arranged eccentrically on the wobble plate in the middle plane between the supports. The wobble 'late 19 is downwardly biased by a helical compression spring 24 and is thereby pressed against the support elements 23. If the switch 12 is turned when the displacement of the contact tube is blocked by way of the teeth of the function selection tooth gear being superimposed, the operating pin 17 is tilted by the convex annular section 18 of the operating cam 13, retained in the groove 14, in such a manner that the wobble plate 19 lifts off from one of the supports 23 as is shown in Fig. 4. The operating pin in this arrangement moves in a kind of tumbling movement with its free end within a curved slot 25 of a face plate 26 of the switch casing 22. As soon as the blocking of the contact tube is released by a changed position of the function selection tooth gears 6, 8 or 9,11, the tension applied by the compression spring 24 causes the operating pin with the operating cam to be returned from its tilted position into the starting position and thereby displaces the contact tube axially to achieve the desired function selection coupling.

The invention is not limited to the embodiment example shown in the figures. For the functioning of the rotary selector switch having function preselection in I 00 accordance with the present invention it is merely required that the operating cam S13 can be deflected in the direction of arrows 27 and 28 as shown in Fig. Sagainst the action of a spring, wherein the strength of the spring determines the engagement force by means of which the contact tube displacement during the already described preselection where the contact tube is being blocked is achieved and thus the coupling of the selection tooth gears for the various C"1 operating functions results as soon as the toothings can mesh together.

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. Rotary selector switch for selecting the various operating functions (drilling/intermediate position/chiselling) in a portable electric tool comprising an 5 axially displaceable control tube serving to select the operating functions and having end profiles for engaging in corresponding mating profiles and having a circumferential groove in which a control cam engages, which can be rotated by the rotary switch about the switch axis in a plane running parallel to the longitudinal axis of the tool, said switch axis running transversely to said longitudinal axis, the control cam being mounted on the rotary switch in such a way as to be pivotable in its path of movement on both sides against a spring force, wherein the control cam is arranged on the end of a control pin which is parallel to the switch axis and is coupled in such a way as to be pivotable against a preloading spring about its foot point connected to the rotary switch in a rotationally fixed manner.

2. Rotary selector switch according to Claim 1, wherein the control pin is guided in a curved slot in such a way as to pass through an end plate of the rotary switch.

3. Rotary selector switch according to either of Claims 1 and 2, wherein the control pin is rigidly fastened eccentrically, centrally between the support points, to a wobble plate which is supported in a rotationally fixed manner in the switch housing on opposite support webs and which, acted on from above by a compression spring, can be optionally tilted about the support webs.

4. Rotary selector switch according to Claim 3, wherein the wobble plate is provided with opposite slots, in which guide webs on the inner wall of the switch housing engage, said guide webs being flanked by two support webs.

Rotary selector switch according to any one of Claims 1 to 4, wherein the P-OPERITLGll\2533OO hp.doc-2204/200 00 -8- O control cam has a crowned annular section for engaging in the circumferential ci groove of the control tube.

6. A rotary selector switch substantially as hereinbefore described with N I 5 reference to the drawings and/or Examples. C-i Oi-