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Publication numberUS3794790 A
Publication typeGrant
Publication dateFeb 26, 1974
Filing dateJan 24, 1973
Priority dateFeb 4, 1972
Also published asDE2304595A1
Publication numberUS 3794790 A, US 3794790A, US-A-3794790, US3794790 A, US3794790A
InventorsLeyland K
Original AssigneeRists Wires & Cables Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electrical switches
US 3794790 A
Abstract
An electrical switch including a first flexible elongated conductor and a second flexible elongated conductor coaxial with the first conductor. An insulating element which is both resilient and deformable spaces the first conductor from the second conductor along the whole length of the first conductor, and the insulating element is loaded with conductive particles. The nature of the insulating element containing the conductive particles is such that compression of the element in a direction to decrease the spacing between the first and second conductors establishes a conductive path within the element between the first and second conductors.
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United States Patent [191 Leyland Feb. 26, 1974 ELECTRICAL SWITCHES [75] Inventor: Kenneth Leyland,

' Newcastle-under-Lyme, England [73] Assignee: Rists, Wires and Cables Limited, Newcastle-under-Lyme, England [22] Filed: Jan. 24, 1973 [2]] Appl. No.: 326,339

[30] Foreign Application Priority Data Apr. 2, 1972 Great Britain 5,276/72 [52] US. Cl. 200/86 R, 200/86 A, 338/114 [51] Int. Cl. H0lh 13/16 [58] Field of Search 338/99, 100, 114; 200/86 R,

. ZOO/61.43

[56] References Cited UNITED STATES PATENTS 2,305,717 12/1942 La Bell 338/114 2,445,660

7/1948 Bruestle 338/114 1/1973 Richards ZOO/61.43

3,710,050 3,509,296 4/1970 Harshman et a1 280/86 3,321,592 5/1967 Miller 200/86 R Primary ExaminerDavid Smith, Jr. Attorney, Agent, or Firm-l-lolman & Stern [5 7] ABSTRACT An electrical switch including a first flexible elongated conductor and a second flexible elongated conductor coaxial with the first conductor. An insulating element which is both resilient and deformable spaces the first conductor from the second conductor along the whole length of the first conductor, and the insulating element is loaded with conductive particles. The nature of the insulating element containing the conductive particles is such that compression of the element in a direction to decrease the spacing between the first and second conductors establishes a conductive path within the element between the first and second conductors.

2 Claims, 1 Drawing Figure ELECTRICAL SWITCHES This invention relates to electrical switches.

A switch according to the invention includes a first flexible elongated conductor, a second flexible elongated conductor, and a resilient, deformable insulating element spacing the first conductor, throughout its length, from the second conductor, the insulating element being loaded with conductive particles whereby compression of the element in a direction to decrease the spacing of the first and second conductors establishes a conductive path within the element between the first and second conductors.

Desirably the first conductor is in the form of a conductive wire or lead, the insulating element is in the form of a sheath within which the first conductor extends, and the second conductor is in the form of a conductive braid encircling said element.

Conveniently the switch also includes an outer flexible protective sleeve.

The accompanying drawing is a diagrammatic representation of an electrical warning system utilizing a switch in accordance with'one example of the invention.

Referring to the drawing the switch 11 includes a first electrical conductor in the form of a copper wire 12. Encircling the wire 12 is an insulating element 13 in the form of a sheath of a resilient deformable insulating material which is loaded with spaced electrically conductive particles, whereby compression of a part of the element 13 urgesthe adjacent particles into contact to render that part of the element 13 conductive. The first conductor 12 extends within the element 13, the element 13 constituting a sheath encircling the conductor 12. Encircling the element 13, is a woven copper braid l4, and in the rest condition of the element 13, the element 13 serves to electrically insulate the copper braid 14 from the copper wire 12. Both the wire 12 and the braid 14 are of course flexible. Deformation of the eletraffic monitoring, or warning systems where a length.

of the switch will be laid across the path of the vehicle. As the vehicle passes over the switch an electrical circuit will be completed momentarily between the braid 14 and the wire 12, and the switch can thus be used to control a device 15 for example a bell or a buzzer in the sheath spacing said first conductor, throughout its length, from said second conductor said sheath encircling said first conductor, the material of said sheath being loaded with conductive particles, whereby compression of said sheath in a direction to decrease thev spacing of said first and second conductors establishes a conductive path within said sheath between said first and second conductors.

2. A switch as claimed in claim 1 wherein the switch also includes an outer flexible protective sleeve.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2305717 *Oct 23, 1939Dec 22, 1942La Bell Oidric JosephCircuit controlling means
US2445660 *Aug 17, 1945Jul 20, 1948Elevator Supplies Co IncElectric treadle
US3321592 *Jul 21, 1966May 23, 1967Miller BrosSafety closure edge
US3509296 *Oct 23, 1967Apr 28, 1970Ncr CoResilient variable-conductivity circuit controlling means
US3710050 *Sep 14, 1970Jan 9, 1973A RichardsElectronic pressure sensitive switch
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4060705 *Apr 7, 1976Nov 29, 1977Cyril John PeacheyPressure actuated continuous switch
US4258100 *Sep 6, 1978Mar 24, 1981Kabushiki Kaisha KyowaComprising at least one layer of a rubber containing fine metal particles
US4359726 *Jan 27, 1981Nov 16, 1982Jacques LewinerComposite sheets constituting electromechanical transducers and transducers equipped with such sheets
US4374374 *Apr 15, 1981Feb 15, 1983Goof Sven Karl LennartElectric contact device
US4839480 *Nov 4, 1987Jun 13, 1989The Gates Rubber CompanyVehicle sensing device
US4935699 *May 15, 1989Jun 19, 1990Westinghouse Electric Corp.Means to detect and locate pinching and chafing of conduits
US5068638 *Sep 11, 1989Nov 26, 1991The Gates Rubber CompanyElectrical sensing element
US6724195 *Nov 27, 2002Apr 20, 2004Jerome R. LurtzContact sensor
US7145432May 17, 2001Dec 5, 2006Canesis Network Ltd.Flexible switching devices
US7186356May 30, 2002Mar 6, 2007Peratech Ltd.Compressible polymer element containing conductive filler; wide electroconductivity range
US7301435Jul 20, 2006Nov 27, 2007Peratech LimitedFlexible switching devices
USRE32180 *Nov 15, 1984Jun 10, 1986 Composite sheets constituting electromechanical transducers and transducers equipped with such sheets
DE4013624A1 *Apr 27, 1990Oct 31, 1990Riken KkQuetschsicheres fenster/tuer-schliesssystem sowie sensoren und schaltungen fuer ein solches system
DE4042496C2 *Apr 27, 1990Mar 7, 1996Riken KkSafety closure system for automatic door or window
WO2001088935A1 *May 17, 2001Nov 22, 2001Peratech LtdFlexible switching devices
WO2003085685A2 *Mar 28, 2003Oct 16, 2003Jerome R LurtzA pressure, temperature and contact sensor
Classifications
U.S. Classification200/86.00R, 338/114, 200/85.00A, 200/86.00A
International ClassificationH01B7/10, H01H35/00, H01H1/02, G08G1/01, H01H1/029, H01H13/52, H01H1/06
Cooperative ClassificationG08G1/01, H01B7/106, H01H1/029
European ClassificationH01B7/10D2, H01H1/029, G08G1/01