Improvements in electrostatic relays

Claim 2

A relay including a first drop of conductive liquid within a cavity formed by a wall of dielectric material, a plurality of flat metal plates forming capacitor plates immediately outside one surface of the wall, the drop of liquid functioning as a capacitor plate within the wall, the drop of liquid responding to electrostatic fields between respective ones of said capacitor plates and itself to effect movement of the drop of liquid from one position to another, said movement causing a loss of contact between at least one pair of relay contacts and the making of contact between another pair of relay contacts, an inert fluid within said cavity in a space between said first drop of conductive liquid and a second drop of conductive liquid, said inert liquid forming means through which the movement of said first drop of conductive liquid is transmitted to and effects the movement of the second drop of conductive liquid, a change of position of said second drop causing changes in conductivity between additional pairs of contacts.

Claim 3

A relay as claimed in claim 1 wherein the movement of said first drop is transmitted to said other drop by means of an electrically insulating inert fluid.

Claim 4

A relay as claimed in claim 1 wherein said second drop is contained within another cavity each end of which opens into a separate one of the ends of said first mentioned cavity via an interconnecting passage, said another cavity being provided with at least one relay contact at each of a plurality of positions, each contact being secured to or formed in the iNner surface of the cavity and being adapted, at each of said positions, to make electrical contact with said second drop.

Claim 5

A relay including a first drop of conductive liquid within a cavity formed by a wall of dielectric material, a plurality of metal plates forming capacitor plates immediately outside the wall, the drop of liquid functioning as a capacitor plate, the drop of liquid responding to electrostatic fields between respective ones of said capacitor plates and itself to effect movement of the drop of liquid from one position to another, said movement causing a loss of contact between at least one pair of relay contacts and the making of contact between another pair of relay contacts, an inert fluid within said cavity in a space between said first drop of conductive liquid and a second drop of conductive liquid, said inert liquid forming means through which the movement of said first drop of conductive liquid is transmitted to and effects the movement of the second drop of conductive liquid, a change of position of said second drop causing changes in conductivity between additional pairs of contacts, said capacitor plates being positioned on a major surface of a flat insulating substrate, said cavity and a plurality of supply and relay contacts associated therewith being formed in another substrate, said another substrate being bonded to the surface of said common layer when the drops of conducting liquid have been metered into the said cavities and the said electrically insulating inert fluid occupying that volume of the said cavities not occupied by the said drops and the volume of the cavity interconnecting passages, and wherein electrical contact leads for said supply contact, each of said other plates, and each of said relay contacts are provided.

Claim 6

A relay including a first drop of conductive liquid within a cavity formed by a wall of dielectric material, a plurality of metal plates forming capacitor plates immediately outside the wall, the drop of liquid functioning as a capacitor plate, the drop of liquid responding to electrostatic fields between respective ones of said capacitor plates and itself to effect movement of the drop of liquid from one position to another, said movement causing a loss of contact between at least one pair of relay contacts and the making of contact between another pair of relay contacts, an inert fluid within said cavity in a space between said first drop of conductive liquid and a second drop of conductive liquid, said inert liquid forming means through which the movement of said first drop of conductive liquid is transmitted to and effects the movement of the second drop of conductive liquid, a change of position of said second drop causing changes in conductivity between additional pairs of contacts, said capacitor plates being positioned on a major surface of a flat insulating substrate, said cavity and a plurality of supply and relay contacts associated therewith being formed in another substrate, said another substrate being bonded to the surface of said common layer when the drops of conducting liquid have been metered into the said cavities and the said electrically insulating inert fluid occupying that volume of the said cavities not occupied by the said drops and the volume of the cavity interconnecting passages, and wherein electrical contact leads for said supply contact, each of said other plates, and each of said relay contacts are provided.

Claim 7

A relay including a first drop of conductive liquid within a cavity formed by a wall of dielectric material, a plurality of metal plates forming capacitor plates immediately outside the wall, the drop of liquid functioning as a capacitor plate, the drop of liquid responding to electrostatic fields between respective ones of said capacitor plates and itself to effect movement of the drop of liquid from one position to another, said movement causing a loss of contact between at least one pair of relay contacts and the making of contact between another pair of relay contacts, an inert fluid within said cavity in a space between said first drop of conductive liquid and a second drop of conductive liquid, said inert liquid forming means through which the movement of said first drop of conductive liquid is transmitted to and effects the movement of the second drop of conductive liquid, a change of position of said second drop causing changes in conductivity between additional pairs of contacts, wherein the capacitor plates are provided on a major surface of a flat insulating substrate, wherein said cavity is formed by part of the surface of said common layer, an aperture formed in another flat insulating substrate such that it is in correct register with other plates, and part of the major surface of a further flat insulating substrate which is bonded to the other major surface of said another substrate when the drops of conducting liquid have been metered into the said cavity and the said electrically insulating inert fluid occupies that volume of the said cavity not occupied by the said drops and the volume of the cavity interconnecting passages and wherein electrical contact leads for said supply contact, each of said other plates, and each of said relay contacts are provided.

Claim 8

A relay including a first drop of conductive liquid within a cavity formed by a wall of dielectric material, a plurality of metal plates forming capacitor plates immediately outside the wall, the drop of liquid functioning as a capacitor plate, the drop of liquid responding to electrostatic fields between respective ones of said capacitor plates and itself to effect movement of the drop of liquid from one position to another, said movement causing a loss of contact between at least one pair of relay contacts and the making of contact between another pair of relay contacts, an inert fluid within said cavity in a space between said first drop of conductive liquid and a second drop of conductive liquid, said inert liquid forming means through which the movement of said first drop of conductive liquid is transmitted to and effects the movement of the second drop of conductive liquid, a change of position of said second drop causing changes in conductivity between additional pairs of contacts, wherein the capacitor plates are provided on a major surface of a flat insulating substrate, wherein said cavity is formed by part of the surface of said common layer, an aperture formed in another flat insulating substrate such that it is in correct register with other plates, and part of the major surface of a further flat insulating substrate which is bonded to the other major surface of said another substrate when the drops of conducting liquid have been metered into the said cavity and the said electrically insulating inert fluid occupies that volume of the said cavity not occupied by the said drops and the volume of the cavity interconnecting passages and wherein electrical contact leads for said supply contact, each of said other plates, and each of said relay contacts are provided.

Claim 9

A relay as claimed in claim 1 including a plurality of cavities providing a number of positions into which the drop of liquid may move and including means for latching said drop into each of said positions.

Claim 10

A relay as claimed in claim 6 wherein said latching means are provided by increasing the cross-sectional area of the cavities at the positions where said relay contacts and said supply contact are located.

Claim 11

A relay iNcluding a drop of conductive liquid within a cavity formed by a sealed tube of dielectric material, said drop of liquid forming a capacitor plate, electrical supply contacting means terminating within the cavity and extending throughout the cavity parallel to the axis of the tube and through end walls of the tube to provide continuous electrical contact with said drop, a plurality of capacitor plates aligned outside said cavity and along one side thereof, means for applying potential across individual capacitor plates and said drop to produce electrostatic fields, said electrostatic fields producing mechanical forces causing said drop of liquid to move from a position near a low electrostatic field to a position near a high electrostatic field within the cavity, and at last one relay contact provided at each of said positions, said relay contact being extended through the wall of the tube to a position enabling contact with the drop of liquid on a side of the tube opposite to the side along which the capacitor plates are aligned, each said relay contact being adapted at each of said positions to make electrical contact with said drop of conductive liquid when the drop is in a certain position.

Claim 12

A relay iNcluding a drop of conductive liquid within a cavity formed by a sealed tube of dielectric material, said drop of liquid forming a capacitor plate, electrical supply contacting means terminating within the cavity and extending throughout the cavity parallel to the axis of the tube and through end walls of the tube to provide continuous electrical contact with said drop, a plurality of capacitor plates aligned outside said cavity and along one side thereof, means for applying potential across individual capacitor plates and said drop to produce electrostatic fields, said electrostatic fields producing mechanical forces causing said drop of liquid to move from a position near a low electrostatic field to a position near a high electrostatic field within the cavity, and at last one relay contact provided at each of said positions, said relay contact being extended through the wall of the tube to a position enabling contact with the drop of liquid on a side of the tube opposite to the side along which the capacitor plates are aligned, each said relay contact being adapted at each of said positions to make electrical contact with said drop of conductive liquid when the drop is in a certain position.

Claim 13

A relay as claimed in claim 8 wherein electrical contact leads for each of said relay contacts are provided which pass through and are secured within the wall of said hollow insulating member.

Claim 14

A relay as claimed in claim 8 wherein said sealed tube of dielectric material includes means for latching said drop into each of said positions.

Claim 15

A relay as claimed in claim 10 wherein said latching means are provided by reducing the cross-sectional area of the cavity formed by the hollow insulating member at a point mid-way between said positions.

Claim 16

A relay as claimed in claim 11 wherein a single relay contact is provided at each of said positions.

Claim 17

A relay as claimed in claim 10 wherein said latching means are provided by increasing the cross-sectional area of the cavity formed by the sealed tube at two points at each of said positions.

Claim 18

A relay as claimed in claim 13 wherein two relay contacts are provided at each of said positions, each of said relay contacts being located at a point where the said cross-sectional area is increased.

Claim 19

A relay as claimed in claim 8 wherein the conductive liquid consists of a material in the liquid state taken from a group of materials including mercury, gallium, indium, alkaline metals, ionic solutions, and mercury amalgams.

Claim 20

A relay as claimed in claim 8 wherein the conductive liquid consists of an alkaline metal in a sodium/potassium compound.

Claim 21

A relay as claimed in claim 8 wherein said common layer consists of dielectric material taken from a group of materials including silicon nitride, aluminum oxide and tantalum oxide.

Claim 22

A relay as claimed in claim 17 wherein the said other plates consist of materials selected from aluminum or tantalum metal when said common layer is respectively of aluminum oxide or tantalum oxide.

Claim 23

A relay as claimed in claim 8 wherein the hollow insulating member is of glass.

Claim 24

A relay as claimed in claim 4 wherein said insulating substrates are of glass.

Claim 25

A relay as claimed in claim 8 wherein said drop is contained within a cavity in a manner such that it is at all times in contact with the tube of dielectric material, wherein said cavity is provided with a fluid inlet port and wherein said cavity is provided with at least one fluid outlet port at each of said positions, said drop being adapted when at each of said positions to isolate the outlet port thereat from the said inlet port thereby directing the fluid input to the other outlet port or ports of the relay.