Vent cap for batteries

Claim 2

A VENT CAP FOR AN ELECTRICAL CELL HAVING A LIQUID ELECTROLYTE COMPRISING: A HOLLOW BODY ADAPTED TO BE CONNECTED TO AN OPENING IN SAID CELL LEADING TO SAID ELECTROLYTE, A MEMBRANE DISPOSED IN AND EXTENDING ACROSS THE INTERIOR SPACE OF SAID HOLLOW BODY, FIRST AND SECOND CONCENTIVE MEMBRANE SUPPORT MEMBERS WITHIN AND ATTACHED TO SAID HOLOW BODY, SAID SUPPORT MEMBERS BEING SPACED RADICALLY FROM ONE ANOTHER, AND MEANS FRICTIOALLY SECURING SAID MEMBRANE TO SAID FIRST AND SECOND MEMBRANE SUPPORT MEMBERS SO THAT THE MEMBRANE EXTENDS BETWEEN SAID SUPPORT MEMBERS, SAID SUPPORT MEMBERS BEING SPACED APART SUFFICIENTLY SO THAT A SUBSTANTIAL AREA MEMBRANE IS EXPOSED TO GASES ANS ELECTROLYTE WITHIN SAID CELL, SAID MEMBRANE BEING MADE OF A MATERIAL THAT IS PERMABLE TO GASES GENERATED WITHIN SAID CELL AND SERVES AS A BARRIER TO FLOW OF ELECTROLYTE THROUGH SAID BODY, SAID MAERIAL COMPRISING A MICROPOROUS POLYTETRAFLUORETHYLENE SHEET WITH A PORE SIZE IN THE RANGE OF ABOUT 2 TO ABOUT 10 MINCRONS.

Claim 3

A vent cap according to claim 1 wherein said membrane support members are disposed so as to support said membrane at its center and also at its periphery.

Claim 4

A vent cap according to claim 1 wherein said membrane has pores with a pore size in the range of about 5 to about 10 microns.

Claim 5

A vent cap according to claim 1 wherein said means for securing said membrane to said support members comprises a retainer member disposed within and secured to said body, said retainer member having openings for venting gas passing through said membrane.

Claim 6

A battery cap assembly for a battery of the liquid acid electrolyte type comprising in combination: a tubular enclosure; a wall extending across the interior of and integral with said enclosure; said wall being formed with one or more openings therethrough and including at least two spaced flanges with at least one of said flanges being formed adjacent the periphery of said wall; a membrane formed of a material that is substantially permeable to hydrogen and oxygen gas but substantially impermeable to liquid acid electrolyte, said material comprising a microporous sheet having a pore size in the range of about 2 to about 10 microns, said membrane being disposed within said enclosure and supported on said flanges; a retainer member mounted within and secured to said tubular enclosure, said retainer member overlying said membrane and having (a) projecting means for clamping selected portions of said membrane to said flanges whereby to secure said membrane to said enclosure, and (b) one or more openings for venting gas passing through said membrane; and means for securing said retaining member to said wall.

Claim 7

A battery cap assembly for a battery of the liquid acid electrolyte type comprising in combination: a tubular enclosure; a wall extending across the interior of and integral with said enclosure; said wall being formed with one or more openings therethrough and including at least two spaced flanges with at least one of said flanges being formed adjacent the periphery of said wall; a membrane formed of a material that is substantially permeable to hydrogen and oxygen gas but substantially impermeable to liquid acid electrolyte, said material comprising a microporous sheet having a pore size in the range of about 2 to about 10 microns, said membrane being disposed within said enclosure and supported on said flanges; a retainer member mounted within and secured to said tubular enclosure, said retainer member overlying said membrane and having (a) projecting means for clamping selected portions of said membrane to said flanges whereby to secure said membrane to said enclosure, and (b) one or more openings for venting gas passing through said membrane; and means for securing said retaining member to said wall.

Claim 8

A battery cap assembly as defined in claim 5 wherein said projecting means are formed integral with said retainer member.

Claim 9

A battery cap assembly as defined in claim 5 wherein said selected portions of said membrane are compressively deformed by the clamping action of said projecting means.

Claim 10

A battery cap assembly as defined in claim 5 wherein said retainer member is secured to said wAll at a single point by a fastener which is anchored in said wall, and said retainer member is deformed radially of said single point.

Claim 11

A vent cap for an electric cell containing a liquid electrolyte comprising: a hollow body having an inlet and an outlet for gases escaping from an opening in said cell leading to said electrolyte and having a portion adapted for connecting said inlet to an opening in said cell; said body also having first and second radially spaced concentric projections in its interior between said inlet and outlet; a membrane retainer member disposed within said body and having third and fourth radially spaced concentric projections aligned with said first and second projections respectively, said retainer member having at least one opening for passing gas from said inlet to said outlet; a membrane formed of a material that is substantially permeable to hydrogen and oxygen gas but substantially impermeable to said liquid electrolyte, said membrane being disposed within and extending transversely of said hollow body with a first outer portion thereof extending between said first and third projections and a second inner portion thereof extending between said second and fourth projections thereof; and means for securing said retainer member to said hollow body so that said member iis clamped between the projections of said body and the projections of said retainer member.

Claim 12

A vent cap for an electric cell containing a liquid electrolyte comprising: a hollow body having an inlet and an outlet for gases escaping from an opening in said cell leading to said electrolyte and having a portion adapted for connecting said inlet to an opening in said cell; said body also having first and second radially spaced concentric projections in its interior between said inlet and outlet; a membrane retainer member disposed within said body and having third and fourth radially spaced concentric projections aligned with said first and second projections respectively, said retainer member having at least one opening for passing gas from said inlet to said outlet; a membrane formed of a material that is substantially permeable to hydrogen and oxygen gas but substantially impermeable to said liquid electrolyte, said membrane being disposed within and extending transversely of said hollow body with a first outer portion thereof extending between said first and third projections and a second inner portion thereof extending between said second and fourth projections thereof; and means for securing said retainer member to said hollow body so that said member iis clamped between the projections of said body and the projections of said retainer member.

Claim 13

A vent cap according to claim 9 wherein said last-mentioned means is a pin that is locked to said body and said retainer member and extends through said membrane.

Claim 14

A vent cap according to claim 9 wherein said retainer member comprises a web portion between said third and fourth projections, said web portion being flat in its as-formed state and being deformed radially between said third and fourth projections when said retainer member is in its as-secured position within said body.