US2798907A - Electric switches - Google Patents

Description

July 9; 1957 H. w. SCHNEKDER ELECTRIC SWITCHES Filed Apfil 20, 1954 4 Sheets-Sheet 1 INVENTOR Hmvs h/ERP HARD SCHNEIDER BY l Julyfi9, 1957 w, H ER 2,798,907

ELECTRIC SWITCHES 4 Sheets-Sheet 2 Filed April 20, 1954 FIG.2.

INVENTOR HAP/s WERHHARD SCHNEIDER BY wyw-i ELECTRIC SWITCHES 4 Sheets-Sheet 5 Filed April 20. 1954 H. w. SCHNEIDER 2,798,907

ELECTRIC SWITCHES July 9, 1957 4 Sheets-Sheet 4 Filed April 20. 1954 INVENTOR HAP/5 wERP/HARD SCHNEIDER BY 0.2/ M

United States Patent ELECTRIC SWITCHES Hans Wernhard Schneider, Old Woking, England, as-

signor to Castelco (Great Britain) Limited, Old Waking, England Application April 20, 1954, Serial No. 424,427

Claims priority, application Great Britain April 21, H53

Claims. (Cl. ZOO-=44) The invention is particularly concerned with electric switches of the miniature type which include a base and cover plate each moulded from insulating material the base containing fixed contacts and a movable contact member which is operated either by means of a push button or by a rotary operating member, the latter being usually actuated through the medium of a chain or other flexible component, the rotary mechanism usually incorporating a ratchet wheel or its equivalent and a spring for returning it to its initial position. i The invention is particularly concerned with the electric switch forming the subject of prior British Patent No. 592,480 in which the push button imparted a unidirectional step-by-step rotary movement to the movable contact member although the invention can be applied to the alternative type of miniature switch disclosed by prior British Patent No. 592,481 in which contact was broken immediately the push button was released or to the type of switch forming the subject of a third prior British Patent No. 644,265 which switch incorporated the ratchet or equivalent mechanism hereinbefore referred to.

In all three types of switches the base contained two fixed contacts which were located in recesses in the base, the movable contact member including resilient arms 'which in the case of British Patents Nos. 592,480 and 644,265 were arranged to make and break contact with 'the fixed contact members with a quick snap action.

Such switches as form the subject of the earlier patents above referred to are of quite small dimensions and hitherto were of the simple single pole type. Although such single pole switches have been found to be perfectly satisfactory in use it is sometimes necessary to provide switches of the double or multi-pole type and the chief object of the present invention is to evolve a switch having two or more poles with the aid of the component parts used in the construction of single pole switches forming the subject of the above numbered patents and without increasing to any material extent the comparatively small dimensions of the switches as previously produced.

An electric switch in accordance with the present invention of the double or multi-pole type hereinafter referred to as the multi-pole type comprises a plurality of superimposed base members each containing fixed contacts and a moving contact mounted for angular or uni-directional step-by-step rotary movement, the moving contacts being connected by a connecting member or. members so that they move in unison, a cover plate carried by the uppermost base member and means for moving the moving contact members to complete or break the electrical circuit.

The base members are of substantially identical construction and have the same outside form and dimensions the base member or members other than the lowermost base member being formed with a centrally positioned boring for accommodating an insulating coupling memher which serves to connect the movable contact members together in series.

The arrangement is such that a switch having any desired number of poles can be built up by taking the required number of base members and their associated parts and assembling them together one above the other the base members and their common cover plate being finally rivetted or screwed together.

The various moving contact members will generally be so arranged that they all make or break contact simultaneously but they can be easily so arranged that when one contact member is making another will be breaking contact.

Referring to the drawings Figure 1 is a vertical section drawn to an enlarged scale of a double pole electric switch in accordance with the invention;

Figure 2 is an exploded view;

Figure 3 is an under perspective view of the connector element;

Figure 4 is a side elevation of one of the movable contacts;

Figure 5 is a plan view of one of the fixed contacts of the switch illustrated by Figures 1 to 4;

Figure 6 is a perspective view of one of the moving contacts;

Figures 7 and 9 are perspective views of two cord or chain operated double pole switches in accordance with the invention;

Figure 8 is a horizontal section drawn to an enlarged scale through-the switch illustrated in Figure 7;

Figure 10 is a rear elevation of the switch shown in Figure 6 with the base plate removed;

Figure 11 is a transverse section on the line A-B in Figure 10;

Figure 12 is an exploded perspective view of the main component parts of the modified switch referred to in the last paragraph on page 7.

The invention will be hereinafter described with reference to Figures 1 to 4 as applied to the particular form of switch disclosed by prior British Patent No. 592,480 the switch including two base members i and 2 moulded from a suitable synthetic resin material the base members being assembled one upon the other a cover plate 3 surmounting the two base members, the cover plate including a tubular neck portion 4 and being externally screw threaded at 5 to receive a securing nut 6 by which the switch can be mounted on a hole in a panel or other convenient support 7 'The tubular neck portion 4 contains as hitherto a push button 8 which actuates a helical movable contact operating member 9, a coil spring 10 being arranged beneath the button for holding it normally in its raised inoperative position. Depression of the push button results in part rotational movement of the helical member, the latter actuating the movable contact member with a stepby-step rotary motion.

The push button 8 is formed with three radial projections 11 which slide in splined grooves 12 in the neck portion, thus preventing rotation of the push button, the helical member a passing through a slot in a metal washer 13 which is likewise formed with three radial projections '14 which likewise engage the splined grooves 12. In this way a part rotational movement will be imparted to the helical member when the push button is depressed.

The movable contact member takes the form of a disclike washer 15 having a pair of depending resilient arms 16 adapted to engage a pair of fixed contacts 17 located in the uppermost base member.

\ The helical member 9 is formed with two radial arms 18 and with a depending projection 19, the latter passing through a central hole in the moving contact member.

The arms 18 engage oppositely positioned pairs of four upstanding inclined tangs 20 pressed out of the movable contact member so that the movable contact member will be given a 90 angular movement eachtime the push button is depressed, the arms 18 overriding the tangs on the spring urged return movement.

The uppermost base member 2 is bored centrally to accommodate the neck 21 of a connector 22 composed of insulating material which serves to engage and actuate the movable contact member 150 located in the base member 1 arranged directly beneath, this second contact member a being similar in construction to the contact member 15 first mentioned and co-operating with fixed contacts 17a located in the second base member. Such a switch will, of course, be of the double pole type but any number of poles may be provided by the provision of additional base members. I

The connector 22 is formed with four equidistantly spaced sector shaped recesses 23 in the under surface which form intervening projections and engage the tangs hereinbefore referred to and impart the desired 90 angular movement to the lower contact member 15a.

The base members may be recessed to accommodate terminal blocks 24 which serve to hold the fixed contacts in position, or alternatively the base member may be formed with protuberances having the same general shape of the terminal blocks which serve to hold the contacts firmly in position, the contacts in this case projecting from the base plate to provide soldering tags.

The connector is slotted at its upper end to receive the downwardly extending protuberance 19 on the helical movable contact operating member 9 and is formed on its under side with a further protuberance 25 which is located in a recess in an upstanding centrally positioned protuberance 26 at the bottom of the lowermost base member. In this way the various moving contact members will be coupled together in such a manner that they will be given in unison a uni-directional rotational movement.

The various base members which it will be seen are all of substantially the same form will finally be joined togcther and connected with the cover plate by means of rive-ts or securing screws.

The fixed contacts 17 and 17.1 are preferably located in recesses so that the arms 16 of the moving contact members will spring into and out of engagement with the fixed contacts with a quick snap action.

In the case of a switch of the [type forming the subject of British Patent No. 592,481 intended to make momentary contact which is broken when the push button is released, the fixed contacts and moving contact will be of modified construction as shown in Figure 12 bearing in mind the fact that in such a case the movement imparted to the rotary contact members will be of a simple angular movement, the spring associated with the push button serving to return the contact members to their initial positions immediately the push button is released. In such a case the moving contacts 15 and 15a as previously described will be omitted. The arms 18 will in such a case form the moving contact, the two fixed contacts having upwardly bent finger-like parts which enter the path of arcuate movement of the arms 18 so that the arms 18 will come into engagement with the fingers to complete the electrical circuit or if the parts are so arranged that the spring normally maintains the contacts in engagement, the arms 18 will be moved out of engagement with the fixed contacts when the push button is depressed. In such constructions the connector 22 may carry a pair of arm-like contacts which can engage upstanding fingers on the lower fixed contacts 17a.

Referring now to Figures 7 to 11 the switch shown in Figure 7 is similar generally to that disclosed by Figures l to 4 except for the fact that it is operated by means of a spring returned drum 27 and chain 28 and consequently no helical member 9 is required to translate axial movement of the push button to part rotational movement, the part which takes the place of the member 9 being coupled directly to the drum and being of insulating material, the part being formed at its inner end with projections which co-operate with tangs on a contact member identical with that previously described, the connecting member being also similar in construction to that previously described.

In the construction shown in Figures 9 to 11 the switch is again of the double pole type and includes two base members 1 and 2 and a cover plate 3. The base member 2 is recessed to accommodate a rack 29, the teeth of which mesh with teeth on a pinion 30 composed 'of insulating material, the rack being moved downwardly by a cord 31 and returned by an associated coil spring 32.

The pinion 30 is formed with a projection 32a at one end which rotates in a boring in the cover plate 3 and with a projection 33- at its opposite end of square or other non-circular cross-section which engages a similarly shaped recess in the neck 21 of the connectingmembern.

The connecting member is formed with four sector shaped recesses 23 forming intervening projections which engage tangs 20 on the adjacent contact member 15a the end of the pinion being similarly formed, the recesses being designated by reference numerals 23a which cooperate with the tangs 20 on the adjacent contact member 15. Fixed contacts 17 and 17a are provided which are either associated with terminal blocks or carry soldermg tags.

The three components 1, 2 and 3 are secured together by rivets 33, which are preferably hollow to. receive securing screws for mounting the switch in position on a supporting surface.

I claim:

1. An electric switch of the multi-pole type comprising, in combination, a plurality of superimposed base members; fixed contacts and a moving. contact mounted within each base member, respectively, each moving contact being mounted for angular movement into and out of engagement with its respective fixed contacts, each of said moving contacts being formed from a resilient material and having resilient contact portions for engaging its respective fixed contacts; and manually operable means engaging one of said moving contacts to move the'same into and out of electrical connection with its respective fixed contacts and adjacent moving contacts being operatively connected by a coupling memberof insulating material.

2. An electric switch as claimed in claim 1, wherein the connecting member is shaped at one end for engagement by the switch actuatingmember and at the other end to engage resilient lugs pressed out from its adjacent moving contactmember.

3. An electricswitch as claimed in claim 2, wherein the connecting member is formed at one end with a series of sector shaped recesses forming between them intervening radial projections for engagement with the lugs on the adjacent moving contact member.

4. An electric switch as claimed in claim 2, wherein the connecting member is formed with a neckv portion having a bearing in a boring formed in one of the base members.

5. An electric switch as claimed in claim 4, wherein the neck onthe connecting member is formed with a recess of non-circular cross-section for engagement by a similar cross-section projection on a switch actuating member.

References Cited in the file of this patent UNITED STATES PATENTS

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