Bipolar filtered feedthrough terminal

Claim 2

A bipolar filtered feedthrough terminal comprising: a cylindrical conductive tubular shell; an insulating end cap having first and second electrical leads extending therethrough and hermetically sealed therein, said end cap being hermetically sealed inside a first end of said shell; first and second metallic contact tubes mounted on ends of said leads inside said shell; and a laminated bipolar capacitor disk fitting into a second end of said shell with said first and second contact tubes passing through said disk, said disk providing separate capacitors between said shell and respective first and said second contact tubes.

Claim 3

The terminal of claim 1 further including resilient conductive means fitted between an outer periphery of said laminated disk and an inner surface of said shell for providing electrical connection between said capacitors and said shell.

Claim 4

The feedthrough terminal of claim 1 wherein said bipolar capacitor disk has a plated outer circumference and comprises a plurality of laminations, each said lamination comprising a thick conductive film on an insulating substrate and having first and second tube holes therethrough, there being at least two discrete types of laminations classified according to the shape of the conductive film thereon, with no two adjacent laminations being of the same type.

Claim 5

The terminal of claim 3 wherein a first lamination type comprises thick conductive film extending to the peripheral edge of the lamination but spaced from said tube holes, and a second lamination type comprises thick conductive film extending to the edge of only one of said tube holes and spaced from the peripheral edge of the lamination.

Claim 6

The terminal of claim 4 wherein a pair of laminations of said second type are arrayed on opposite sides of a lamination of said first type with said pair being oriented to make electrical contact with respective ones of said first and second contact tubes, thereby forming separate capacitors between said respective first and second contact tubes and said lamination of said first type.

Claim 7

The terminal of claim 4 wherein said laminations are arrayed to form interleaved parallel-­plate capacitors, one such capacitor between said first contact tube and said shell, and a second such capacitor between said second contact tube and said shell.

Claim 8

The terminal of claim 4 wherein said bipolar capacitor disk comprises n laminations of the second type and n+1 laminations of the first type interleaved together with n/2 laminations of the second type connected together to the first contact tube and the remaining laminations of the second type being connected together to the second contact tube, the laminations of the first type being connected together to a common reference point.

Claim 9

The terminal of claim 2 wherein said resilient conductive means comprises an unclosed ring of a thin metallic strip with a plurality of tabs having edges protruding from the ring surfaces to establish contact between the peripheral metallic surface of the disk and the inner surface of the shell.

Claim 10

The terminal of claim 8 wherein said tabs are formed by a plurality of transverse cuts in the thin metallic strip along one edge thereof, each tab being twisted slightly with respect to an adjacent uncut portion of said strip contiguous with said tab.

Claim 11

A bipolar filtered feedthrough terminal for providing electrical connection from a first, hermetically sealed environment to a second environment, comprising: a cylindrically symmetrical conducting shell having a cylindrical bore therein extending along a longitudinal axis; a ceramic end cap hermetically sealed into one end of said cylindrical bore, said cap having first and second electrical leads extending generally parallel to said axis through said ceramic end cap and hermetically sealed therein; first and second metallic contact tubes having inner diameters fitting said first and second electrical leads and mounted thereon within said bore; and a laminated bipolar capacitive cylindrical plug with first and second holes therethrough for said first and second contact tubes, each lamination of said plug consisting of a thick conducting film on an insulating substrate, with films connected to said shell and to said first and second contact tubes so as to form separate first and second parallel-plate capacitors between said first contact tube and said shell and between said second contact tube and said shell, respectively.

Claim 12

A bipolar filtered feedthrough terminal for providing electrical connection from a first, hermetically sealed environment to a second environment, comprising: a cylindrically symmetrical conducting shell having a cylindrical bore therein extending along a longitudinal axis; a ceramic end cap hermetically sealed into one end of said cylindrical bore, said cap having first and second electrical leads extending generally parallel to said axis through said ceramic end cap and hermetically sealed therein; first and second metallic contact tubes having inner diameters fitting said first and second electrical leads and mounted thereon within said bore; and a laminated bipolar capacitive cylindrical plug with first and second holes therethrough for said first and second contact tubes, each lamination of said plug consisting of a thick conducting film on an insulating substrate, with films connected to said shell and to said first and second contact tubes so as to form separate first and second parallel-plate capacitors between said first contact tube and said shell and between said second contact tube and said shell, respectively.

Claim 13

The terminal of claim 10 wherein the outer circumference of said plug is plated with a conductive metal layer and further including a contact ring fitting between said outer circumference of said laminated plug and an inner surface of said shell to establish electrical connection therebetween.

Claim 14

The terminal of claim 11 wherein said contact ring comprises a strip of thin metal having a plurality of parallel cuts therein along one long edge thereof to form a plurality of rectangular tabs, each tab being twisted slightly to provide edges for contacting the metal surface of the plug and the inner surface of the shell, said strip being formed into an unclosed ring.

Claim 15

The terminal of claim 12 wherein said contact ring comprises nickel having a thickness of about 0.003 inch, and each tab is substantially square with a length equal to roughly 0.3 times the width of said strip.

Claim 16

The terminal of claim 10 wherein each contact tube comprises an end portion at a first end of said tube having a first diameter, a flange at a second end of said tube, and a body portion between said end portion and said flange, said body portion having a second diameter which is greater than said first diameter and less than the diameters of said first and second holes to permit insertion therein.

Claim 17

The terminal of claim 14 wherein said body portion is deformed out of round to establish an interference fit when inserted into a corresponding hole in said plug.

Claim 18

The terminal of claim 10 wherein said ceramic cap defines a transverse slot in an external end face between said first and second leads.