GB2340663A

GB2340663A - Operating mechanism

Info

Publication number: GB2340663A
Application number: GB9817527A
Authority: GB
Inventors: David William Jones
Original assignee: Craig and Derricott Ltd
Current assignee: Craig and Derricott Ltd
Priority date: 1998-08-13
Filing date: 1998-08-13
Publication date: 2000-02-23
Also published as: AU5184999A; WO2000010183A1; GB9817527D0

Abstract

A mechanism for displacing at least one actuating member 22, 23 in a direction in response to displacement of an operating member 15 in said direction includes four elements 24-27 pivotally connected to one another generally in the form of a rhombus, with a pivotable connection 28 between a first two of the elements being displaced by the operating member and the pivotable connection 31 between the other two of the elements being held stationary, the at least one actuating member 22, 23 being engaged by at least one 26, 27 of said elements between the ends thereof. The mechanism is applicable to push-button operated electrical switches.

Description

2340663 Title: OPERATING MECHANISM

Description of Invention

This invention relates to an operating, mechanism, for effecting displacement of a member (herein called an actuating member) in a direction in c) response to a displacement of a further member (herein called an operating member) in that direction.

The invention has been devised in relation to push-button operated electrical switches. There are many situations in 1',,liicli push-button operation of electrical switches is required, and in some situations a single push-button inay be required to operate several sets of contacts in a single switching unit or 0 a number of switching units assembled in relation to one another so as to be operable from a single push-button. If one or more of such switches are of 0 heavy-duty type, the force required to be exerted by an operator on the pushbutton may be substantial: such switches characteristically, include strong springs to resist inovernent of their operating inenibers. If switch. operation is 1 0 required frequently, the requirenient for an operator repeatedly, to press a push button against a strong spring force is potentially hazardous in terms of repetitive strain injury to the operator.

It is well known that a siniple lever arrangement can be utilised to 0 provide a nieclianical advantage between an actuating meniber of an electrical ? n switch and an operator's Push-button, bUt this is a bulky arrangement and not readily accommodated in, for exaniple, a control panel incorporating a large 0 In munber of 1)iisli-blittOll operated swItelies adjacent one another.

Accordin-Iy, there is a requirement for an operating mechanism by 0 C1 which a mechanical advanta-e can be established between an actuatina member C> c) of a switch and an operator's push-button, but which is siniple and compact. It 2 is the object of the present invention to meet, as fai- as possible, this requirement.

According to the present invention, we provide a mechanism for 0 displacing at least one actuating mernber ill a direction in response to 0 0 displacement of ail operating inember in said direction, said; mechanism 1 including four eleniews pivotally comiected to otic another generally in the It> form of a rhombus, with the pivotal connection betweerI a first two of said elements being arranged to be displaced in said direction by said operating member, the pivotal coruiection between the other t-wo of said elements being held stationary, and said at least one actitatin,(,,, member being engaged by one or z IC) t) 0 both of the other two of said elements between the ends thereof.

Ill a mechanism in accordance with the invention, the arrangement of the foul- elements in the configuration of a rhombus is such that displacement of 0 the operating member results ill a flattening of the rhombus and hence pivotal 1 C> movement of said other two elements about the point of their pivotal connection to one another which is held stationary. A giveri displacement of C the or each actuatiri- member en-a-ed by one oi- both of said other two 0 C) C) elements requires a much gi-eater displacement of the pivotal connection between the first two of said eleiiieiits and lictice of the operating member c which engages said connection. The ratio of the iiiagliltude of such C C1 0 displacenients, of course, depends oil the exact geometry of the mechanism.

C) Preferably the operating member comprises or is directly operable by an operator's push-button.

These and other features of the invention will iio\7 be described by way of example with reference to the accompanying, drawings, of Figure 1 illitstrates the irIverition in <-l first operative position, and figure 2 Illustrates it in a second operative position.

Refen-ing to the drawings, the face of a control panel is indicated at 10 and there IS 11101.111ted therein a piisli-biittoii unit iii(licated gerierally at 11. The 0 push-button unit 11 has a bezel 12 and a body 1.3) which extends thi - ough an aperture in the control panel and is somewhat cup-shaped, having a rear portion 0 14. A push-button having a stem 15 and head 16 is mounted within the body 0 13), the stern 15 slidably passing through an aperture 17 in the rear part 14 of C 0 the body. At its free end, where it protrudes beyond the aperture 17, the stem 15 is fitted with a retaining washer 18, e.g. retained by a circlip.

Beneath the push-button unit 1.1 and conriected thereto by a carrying member indicated generally at 19 there are disposed two electrical switches or contactor units 20, 2 1. Each of these is of a type having two pairs of contacts, the respective pairs of contacts of the contactor unit 20 being, operable by actuatino members 22, 2.33 respectively. The contacts may be normally open or 0 normally closed, or there may be one set of contacts of each type, and they are brought to the respective other condition (open or closed) by depression of the respective actuating members 22, 23). The contactor unit 21 has similar 0 actuatino, members not shown which protrude into the contactor unit 20 and are 0 also displaced when the actuating members 22, 2-33 are displaced.

0 Interposed between the end of the stem 15 and the actuatinO members 0 22, 23) there is a inechanisin including four elongate elements 24, 25, 26, 27 1 0 pivotally connected to one another at 28, 29, -3 3 0, -3 3 1. The pivotal cornlection 28 between the elements 24, 25 abuts the end of the stein 15, whilst the pivotal connection -3) 1 bet,,.\,eeii the other two elements 26, 27 is held stationary relative to the connecting member 19. The pivotal connections 29, 30 between the 0 elements 24, 26 and 25, 27 respectively ai.e fi-ce to move within the connecting element 19. The connection 28 between the elements 24, 25 is guided for linear movement relative to the carrying membei. 19, e.g. by having a hinge pin => C) c C whose opposite ends engage in respective slots in opposed sides of the carrying 0 0 C members.

The actuating nienibers 22, 2.3 3 abut the elements 26, 27 between the ends thereof.

4 The elements 24 to 27 are thus pivotally con-nected to one another generally in the configut-ation of a rhombus, and when. the push-button 15, 16 is C depressed the rhombus is flattened as shown in Figure 2 of the drawings. It will be appreciated from a consideration of Figure 2 that a substantial 0 displacement of the push-button 15, 16 has resulted in a proportionate but lesser displaceinenc of the actitatiil,,,, members 22, 2.3, with the ratio between C) such displacements dependent on the exact geometry of the arranggement of the elements 24, 27 and, particularly, where the actuating members 22, 23) engage 0 the elements 26, 27. In any everit, a substantial mechanical advantage is established, so that considerably less force has to be exeiled by the operator on the push-button 15, 16 than the force which would be required to be exerted if the actuating members 22, 2-33 were eiiga,,ed directly by the end of the stem 15.

C) 1 0 Since in a practical iiistallatioii several contactor units as 20, 21 may be connected beneath one aiiothei- for operation by a sin-le push-button, and since C a considerable force inight then be required to be exerted particularly if they are 0 heavy duty units, the invention provides a particularly neat and compact arrangement by, which the force required to be exerted by, an operator can be 0 reduced.

The eleiiieiits 24 to 27 may! be individual rigid eleilil-tits,. e.g. of sheet 1 z metal or an appropriate plastics material, pivotally connected by appropriate hinge arrangeinerits at 28 to 3) 1. Aii alternative possibility is that such elements 1 C1 of an appropriate plastics material may be pivotally connected by "living Iiinge" c) arrangements, i.e. pot.tions k,,liei-ciii the cross-sectional dimension of the material is sufficieiffly sinall to pivotally cotmect the elemerits to one another by flexlii,,, of the inaterial. It Is cii.1s. iged that an assembly. of such elements c iniolit be manufactured as a flat strip of the eleniews iii lme with one another, three flitegral liiii,,e" formations therebetween, the outermost ends 1 0 1:1 of the end eleinents being provided with formations enabling them to be 0 pivotally connected together after the strip of elements has been bent into the rhoinbus configuration.

The features disclosed in the foregoing desefiption, or the c) accompanying drawing, expressed in their specific fon-fis or in terms of a means for performing the disclosed function, or a inetliod or process for attaining the 0 C disclosed result, may, separately or in any combination of such featwes, be utilised for realisine, die invention fil diverse forms thereof.

0 6

Claims

CLAIMS:-

1 A mechanism for displacing at least one actuating member in a C direction in response to displacement of an operatIng inember in said direction, said 0 mechanism includinCY four elements pivotally con.nected to one another generally in C> 0 the form of a rhombus, with a pivotal connection between a first two of said elements being arranged to be displaced in said direction by said operating 0 C> meniber, the pivotal connection being the other two of said elements being held 1 stationary, and said at least one actuating inember by being engaged by one or both 0 Z.) 0 of the other two of said eleinents bet\,.eeii the ends thereof

2. A mecliaiiisni accoi.din,,:,>, to Claim 1 wlierein die operating member conipilses or is directly operable by ati operator's push-button.

A mechanism according to Cialin 1 or Claim 2 wherein said four elements comprise separate components, pivotally connected by hinge means.

4. A mechanism accordin. to Claim 1 or Claini 2 wherein at least bvo of 0 said four elements comprise plastics coinponents iiitegrally connected to one another by Iiving Iiiii,,e" fonnations.

C 0

5. An electrical switcli assenibly coniprisingy switcliing, means having at 1 Z_ least one actuatitio, inenibei- and a iiiecliaiil'siii according to any one of the preceding claims for displacing said at least one actuating member.

C7 0

6. A ineclianisin, or a switeli assenibly ijicoi-poi,,citiiic() sanie, substantiallY as liereinbefore described with reference to the acconipanying drawinos.

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7. Any novel feature or novel combination of features disclosed herein and/or as sbovai in the accompanying drawing.