US3721929A

US3721929A - Electrical switch devices

Info

Publication number: US3721929A
Application number: US00017507A
Authority: US
Inventors: R Gabriel; R Kinross
Original assignee: Communications Patents Ltd
Current assignee: Communications Patents Ltd
Priority date: 1970-08-28
Filing date: 1971-08-26
Publication date: 1973-03-20
Anticipated expiration: 1990-03-20
Also published as: IL37571A; GB1354501A; CH532834A; DE2142340A1; CA950012A; ES200696Y; FR2112204B1; MTP703B; IL37571A0; BE771854A; SE388500B; AU3270071A; ES200696U; ZA715663B; AU463747B2; NL7111747A; FR2112204A1

Abstract

Magnetic reed switches are mounted side-by-side in a switching array operable from a moving magnet and located in a channel of conductive material and magnetic members to provide electromagnetic and electrostatic shielding and a magnetic bridge member is used to inactivate selected ones of the switches.

Description

United States Patent [191 1March 20, 1973 Gabriel et a]. I

[ ELECTRICAL SWITCH DEVICES [56] References Cited [75] Inventors: Ralph Parton Gabriel, Chobham NI. UNITED STATES PATENTS Woking, Surrey; Rupert Ivor Kin- Shepperton, Middlesex, both 3,337,825 8/1967 Brooks ..335/206 x of Great Britain 3,505,869 4/1970 Crawford ..335/206 X 0 3,564,468 2/1971 Sablayrolles et a] ..335/206 [73] Assignee: Communications Patents Limited,

London, England Primary Examiner-Roy N. Envall, Jr. [22] Filed: g 1971 Attorney-Laurence R. Brown [21] App1.No.: 17,507 [57] ABSTRACT Magnetic reed switches are mounted side-by-side in a [30] F r i A li ti P i it D t switching array operable from a moving magnet and located in a channel of conductive material and mag-' Aug. 28, 1970 Great Britain ..4l,538/70 netic members to provide electromagnetic and elecfl I I trostatic shielding and a magneticbridge member is [52] LS. CI used to inactivate Selected ones of the Switches [51] Int. Cl. ..l-l01h 36/00, l-lOlh 41/04 v [58] Field of Search ..335/205, 206, 207, 301 6 Claims, 2 Drawing Figures H 7m (gm/3 5}]? EIIFSL IB LIT t r gnrurun PATENTEUHARZOIQH 3,721,929

INVENTORS Rdpk 'P. Gabi-' Q. Ruvcri I" Kim-cs5 E5 Me KM ATTORNEY ELECTRICAL SWITCH DEVICES This invention relates to electrical switches of the kind described and claimed in our application Ser. No. 13463/69 and seeks to provide an improved form thereof.

It is an object of the present invention to provide means whereby a switch of the kind specified may selectively be rendered ineffective in one or more of its positions.

Accordingly the invention provides an electrical switch device comprising a plurality of magnetically operable reed switch elements each of which is disposed in a channel of conductive material which includes two magnetically permeable members arranged one each side of the reed switch element thereby simultaneously to provide both electrostatic and electromagnetic screening for said reed switch element and a control means associated with at least one reed switch element whereby the magnetic actuation of said element is rendered ineffective.

According to one specific feature of the invention the control means is formed by a magnetically permeable member associated with the reed switch element to form a magnetic shield so preventing actuation of its contacts by the operating magnet.

According to a further specific feature of the invention the control means is formed by an auxiliary reed arranged electrically in series with the reed switch element, said auxiliary reed being operable by a magnetic member associated therewith. Conveniently the magnetic member is a permanently magnetized member arranged to be releasably positioned on or adjacent said auxiliary reed.

In order that the invention may be more readily understood two particular embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings in which FIG. 1 is a cross-sectional view of one embodiment of a switch device in accordance with the present invention, and

FIG. 2 is a schematic diagram of another embodiment of an electrical switch device in accordance with the present invention.

In the switch shown in FIG. 1 a plurality of magnetically operable reed switch elements I are disposed in corresponding channels of conductive material, each channel including two magnetically permeable members 2 arranged one on each side of the reed switch element and associated with a member of non-magnetically permeable conductive material formed by a sheet of copper 3 which is bonded to one face of a sheet 4 of insulating material. Conveniently the members 3, 4 may be formed from a so-called printed circuit panel. The magnetically permeable members 2 are secured in the insulating material 4 by means of portions 5 thereof which extend through corresponding apertures in the members 3, 4 and which are suitably deformed so as to thereafter prevent their withdrawal. It will be noted that each magnetically permeable member 2 comprises a pair of sheets of magnetizable material and each member is common to the channels associated with'adjacent ones of the reed switch elements 1.

The reed switch elements I are actuable by. a permanent magnet 6 carried by a movable arm 7 which serves to position the magnet 6 over that reed switch element which is desired to be actuated at any particular time.

In practice the reed switch elements 1 and magnetically permeable members 2 are arranged to extend readily from a common center, the arm 7 being pivoted on an axis passing through said center and rotatable over the reed switch elements 1.

A control means is associated with one of the reed switch elements in order to render ineffective the magnetic actuation of said element. The control means comprises a bridge 8 of magnetically permeable material releasably engaged in the channel defined between two of the members 2 and forms a magnetic shield which prevents actuation of the contacts of the reed switch element concerned by the magnet 6. In practice the bridge 8 or a plurality thereof may be manually associated with one or more of the reed switch elements. When these elements together form a programme selection switch corresponding to a particular subscriber in a wired broadcasting system that subscriber may be denied certain of the available programmes. If at any time the subscriber is to be permitted to receive one of the denied programmes the bridge 8 is simply removed from the channel housing the reed switch element corresponding to that programme so as to restore its normal operation.

In the arrangement shown in FIG. 2 reed switch elements 10 of the kind shown in FIG. 1 are arranged to be actuated by a movable magnet such as the magnet 6 shown in FIG. 1. Actuation of one of the reed switch elements 10 serves to establish a circuit path between one of the input terminals 11 and the output terminals 12 from which a subscriber of a wired broadcasting system may derive selected programme signals. Resistors l3 serve as isolating impedances to prevent undue interference to other subscribers of the system in the event of a fault occuring associated with the subscriber connected to the terminals 12. Arranged electrically in series with each of the reed switch elements 10 is an auxiliary reed 14 the contacts of which are normally closed. In order to deny to the subscriber deriving programme signals from the terminals 12 one or more of the programmes applied to the corresponding input terminals 11 the appropriate auxiliary reed 14 may have placed on or adjacent thereto a magnet member 15 the magnetic field of which serves to actuate the auxiliary reed so opening its contact. It will be appreciated that if the subscribers reed switch elements 10 associated with that programme are closed upon his.

selection thereof no programme signals will pass to the output terminals 12 whilst the contacts of the auxiliary reed 14 are open. The magnet member 15 is arranged to be releasably positioned on or adjacent the desired auxiliary reed 14 by means for example of a clip fitted thereto which may be engaged with the body of an auxiliary reed 14. Again it is a simple matter to permit a subscriber to receive a denied programme simply by unclipping the magnet member 15 from the auxiliary reed l4 concerned.

It will be appreciated further that the auxiliary reeds 14 may be actuated by electromagnets and that in this case control of the actuation thereof may be effected automatically and/or remotely.

What we claim is:

1 An electrical switch device comprising a plurality of magnetically operable reed switch elements each of which is disposed in a channel of conductive material which includes two magnetically permeable members arranged one on each side of the reed switch element thereby simultaneously to provide both electrostatic and electromagnetic screening for said reed switch element, magnetic means selectively positionable adjacent to said elements to actuate magnetically any one of said switch elements when adjacent thereto, and a control means associated with at least one reed switch element whereby the magnetic actuation of said at least one element by said magnetic means is rendered ineffective, wherein the control means comprises a magnetically permeable member associated with the reed switch element to form a magnetic shield so preventing actuation of its contacts by the operating magnet.

2. An electrical switch device as claimed in claim 1, wherein said control means comprises a bridge of magnetically permeable material releasably engaged in the channel defined between said two magnetically permeable members.

3. In an electrical switch device with a plurality of magnetic reed switches scanned in sequence by switch operating magnet means, control means to render ineffective selectively single ones of said switches when scanned by said magnetic means, comprising in combination, control means comprising a removable member of magnetic material stationarily positionable selectively in a position associated with said single switch to render ineffective said single switch when scanned by said magnetic means.

4. An electrical switch device as claimed in claim 3 wherein said removable member comprises a magnetic shield interspersed between said magnetic means and said single switch 5. An electrical switch device as claimed in claim 1, wherein said control means comprises said magnetic member and an auxiliary reed arranged electrically in series with the reed switch element, said auxiliary reed being operable by a magnetic member associated therewith.

6. An electrical switch device as claimed in claim 5, wherein the magnetic member is a permanently magnetized member arranged to be releasably positioned adjacent said auxiliary reed.

Claims

1. An electrical switch device comprising a plurality of magnetically operable reed switch elements each of which is disposed in a channel of conductive material which includes two magnetically permeable members arranged one on each side of the reed switch element thereby simultaneously to provide both electrostatic and electromagnetic screening for said reed switch element, magnetic means selectively positionable adjacent to said elements to actuate magnetically any one of said switch elements when adjacent thereto, and a control means associated with at least one reed switch element whereby the magnetic actuation of said at least one element by said magnetic means is rendered ineffective, wherein the control means comprises a magnetically permeable member asSociated with the reed switch element to form a magnetic shield so preventing actuation of its contacts by the operating magnet.

4. An electrical switch device as claimed in claim 3 wherein said removable member comprises a magnetic shield interspersed between said magnetic means and said single switch

5. An electrical switch device as claimed in claim 1, wherein said control means comprises said magnetic member and an auxiliary reed arranged electrically in series with the reed switch element, said auxiliary reed being operable by a magnetic member associated therewith.