Patent US1882394A successfully refreshed from Google Patents.
US4728876A
Expired / Lapsed
US
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Orthopedic drive assembly
Assignee: Linvatec Corp
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Filing: 1986-02-19
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Granted: 1988-03-01
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Expires: 2006-02-19
Abstract
Abstract A cordless rechargeable replaceable battery assembly powered drive assembly for driving orthopedic surgical instruments in which the battery has silver and zinc oxide electrodes in sodium hydroxide electrolyte to provide low voltage high current power. The switch is encased in the battery assembly, the battery cells are vented through a microporous polymeric curtain to restrict expulsion of electrolyte, a two speed transmission is provided to change drive speeds, and a brush block on the motor has contacts adapted to be connected in different combinations to change the motor rotation direction.
Inventors
- 👤 Douglas R. Mongeon
- 👤 Frederick J. Palensky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:14
CPC Classifications
A; A61; A61B; A61B90/00; A61B17/00; A61B17/16; A61B17/1613; A61B17/1622; A61B17/1624; A61B17/1628; B; B23; B23B; B23B45/00; B23B45/02; H; H01; H01M; H01M10/00; H01M10/34; H01M50/00; H01M50/20; H01M50/204; H01M50/30; H01M50/317; H01M50/325; H01M50/333; A61B2017/00681; A61B2017/00734; A61B2560/00; A61B2560/02; A61B2560/04; H01M50/271; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
305 words
A drive assembly for driving orthopedic surgical instruments, said drive assembly comprising: a first housing portion; an electric direct current activated motor mounted on said first housing portion and having positive and negative electric power contacts; a second housing portion; a battery mounted on said second housing portion having at least one cell and electrically positive and negative terminals, said cell comprising walls defining a cavity, electrodes electrically coupled to said terminals within said cavity, a liquid electrolyte within said cavity and in which said electrodes are immersed to provide an electrical potential between said terminals, and a vent assembly mounted in said walls, said vent asssembly having a passageway between said cavity and the atmosphere, means mounted in said passageway for allowing gas in said cavity at a pressure above a predetermined level to escape through said passageway, and a curtain of microporous polymeric material entirely across said passageway that permits movement of gas though said curtain and passageway while restricting the movement of liquid through said curtain and passageway; a switch assembly mounted on said second housing portion having an input lead coupled to one of said terminals, an output lead, and means including an actuator movable relative to said second housing portion between off and on positions for making an electrical connection between said input and outlet leads when said actuator is in said one position and for causing said leads to be electrically isolated from each other when said actuator is in said off position, and means for biasing said actuator to said off position; and means for affording releasing engagement between said first and second housing portions and for causing electrical contact between one of said power contacts and the output lead of said switch assembly and between the other of said power contacts and the other of said terminals.
Claim 2
Dependent Claim
305 words
A drive assembly for driving orthopedic surgical instruments, said drive assembly comprising: a first housing portion; an electric direct current activated motor mounted on said first housing portion and having positive and negative electric power contacts; a second housing portion; a battery mounted on said second housing portion having at least one cell and electrically positive and negative terminals, said cell comprising walls defining a cavity, electrodes electrically coupled to said terminals within said cavity, a liquid electrolyte within said cavity and in which said electrodes are immersed to provide an electrical potential between said terminals, and a vent assembly mounted in said walls, said vent asssembly having a passageway between said cavity and the atmosphere, means mounted in said passageway for allowing gas in said cavity at a pressure above a predetermined level to escape through said passageway, and a curtain of microporous polymeric material entirely across said passageway that permits movement of gas though said curtain and passageway while restricting the movement of liquid through said curtain and passageway; a switch assembly mounted on said second housing portion having an input lead coupled to one of said terminals, an output lead, and means including an actuator movable relative to said second housing portion between off and on positions for making an electrical connection between said input and outlet leads when said actuator is in said one position and for causing said leads to be electrically isolated from each other when said actuator is in said off position, and means for biasing said actuator to said off position; and means for affording releasing engagement between said first and second housing portions and for causing electrical contact between one of said power contacts and the output lead of said switch assembly and between the other of said power contacts and the other of said terminals.
Claim 3
Dependent Claim
69 words
A drive assembly according to claim 1 wherein said battery has threee cells with electrodes comprising silver and zinc oxides electrically coupled to said terminal, and potassium hydroxide electrolyte in which said electrodes are immersed to provide an electrical potential between said terminals of about 41/2 volts and provide a battery with a current output range of about 10 to 70 amps and about 14 amp hours of capacity.
Claim 4
Dependent Claim
37 words
A drive assembly according to claim 1 wherein said battery has a plurality of cells with potassium hydroxide electrolyte in the cavities of said cells, and one of said vent assemblies connected to each of said cells.
Claim 5
Dependent Claim
12 words
A drive assembly according to claim 1 wherein said curtain comprises polytetrafluoroethylene.
Claim 6
Dependent Claim
143 words
A drive assembly according to claim 1 wherein said motor comprises a rotor rotatable about an axis and comprising a commutator, a brush holder fixed relative to said first housing portion around said commutator, a plurality of brushes mounted on said brush holder and contacting said commutator, said brush holder having a ring of contacts alternatively connected to the battery and to the brushes, and a switch plate mounted on said first housing portion for rotational movement around said axis between first and second positions, said switch plate including means for connecting said brushes to said battery to cause rotation of said rotor in one direction when said switch plate is in said first position, and for connecting said brushes to said battery to cause rotation of said rotor in the opposite direction when said switch plate is in the said second position.
Claim 7
Dependent Claim
307 words
A drive assembly for driving orthopedic surgical instruments, said drive assembly comprising: a first housing portion; an electric direct current activated motor mounted on said first housing portion and having positive and negative electric power contacts; a second housing portion; a battery mounted on said second housing portion having at least one cell and electrically positive and negative terminals; a switch assembly mounted on said second housing portion having an input lead coupled to one of said terminals, an output lead, and means including an actuator movable relative to said second housing portion between off and on positions for making an electrical connection between said input and outlet leads when said actuator is in said on position and for causing said leads to be electrically isolated from each other when said actuator is in said off position, and means for biasing said actuator to said off position, said actuator being mounted for pivotal movement about an axis between said off and on positions, including a contact member spaced a first distance from said axis, and an actuating member projecting a second distance substantially greater than said first distance from said axis, which actuating member has an outer end portion opposite said axis; a trigger mounted on said first housing portion for movement between outer and inner positions said trigger engaging the outer end portion of said actuating member to move said actuator from said off to said on position upon movement of said trigger from said outer position to said inner position; means for biasing said trigger to said outer position; and means for affording releasable engagement between said first and second housing portions and for causing electrical contact between one of said power contacts and the output lead of said switch assembly and between the other of said power contacts and the other of said terminals.
Claim 8
Dependent Claim
307 words
A drive assembly for driving orthopedic surgical instruments, said drive assembly comprising: a first housing portion; an electric direct current activated motor mounted on said first housing portion and having positive and negative electric power contacts; a second housing portion; a battery mounted on said second housing portion having at least one cell and electrically positive and negative terminals; a switch assembly mounted on said second housing portion having an input lead coupled to one of said terminals, an output lead, and means including an actuator movable relative to said second housing portion between off and on positions for making an electrical connection between said input and outlet leads when said actuator is in said on position and for causing said leads to be electrically isolated from each other when said actuator is in said off position, and means for biasing said actuator to said off position, said actuator being mounted for pivotal movement about an axis between said off and on positions, including a contact member spaced a first distance from said axis, and an actuating member projecting a second distance substantially greater than said first distance from said axis, which actuating member has an outer end portion opposite said axis; a trigger mounted on said first housing portion for movement between outer and inner positions said trigger engaging the outer end portion of said actuating member to move said actuator from said off to said on position upon movement of said trigger from said outer position to said inner position; means for biasing said trigger to said outer position; and means for affording releasable engagement between said first and second housing portions and for causing electrical contact between one of said power contacts and the output lead of said switch assembly and between the other of said power contacts and the other of said terminals.
Claim 9
Dependent Claim
64 words
A drive assembly according to claim 6 wherein said contact member is a conductive blade having a tapered edge and said switch assembly further includes opposed spring members each defining half of a generally V-shaped surface adapted to resiliently separate and frictionally receive movement of the conductive blade therebetween tapered edge first upon movement of said actuator from its off to its on position.
Claim 10
Dependent Claim
50 words
A drive assembly according to claim 6 wherein said actuating member is encased by said second housing portion, said trigger has a projection adapted to engage the end portion of said actuator, and said second housing portion has an opening to afford engagement of said projection with said end portion.
Claim 11
Dependent Claim
329 words
A drive assembly for driving orthopedic surgical instruments, said drive assembly comprising: a first housing portion; an electric direct current activated motor mounted on said first housing portion and having positive and negative electric power contacts, said motor comprising a a rotor rotatable about an axis and including an axially projecting output shaft; manually activatable means for axially shifting said output shaft relative to said first housing portion between first and second positions; a drive member rotatably mounted on said first housing portion at an axially fixed position, said drive member being adapted to releasably engage a surgical instrument; transmission menas between said motor and said drive member coupled to said drive member, and engaged by said output shaft in either of said first and second positions for driving said drive member at a first drive ratio when said outpt shaft is in said first position, and for driving said drive member at a second drive ratio different than said first drive ratio when said output shaft is in said second position; a second housing portion; a battery mounted on said second housing portion having at least one cell and electrically positive and negative terminals; a switch assembly mounted on said second housing portion having an input lead coupled to one of said terminals, an output lead, and means including an actuator movable relative to said second housing portion between off and on positions for making an electrical connection between said input and outlet leads when said actuator is in said one position and for causing said leads to be electrically isolated from each other when said actuator is in said off position, and means for biasing said actuator to said off position; and means for affording releasable engagement between said first and second housing portions and for causing electrical contact between one of said power contacts and the output lead of said switch assembly and between the other of said power contacts and the other of said terminals.
Claim 12
Dependent Claim
329 words
A drive assembly for driving orthopedic surgical instruments, said drive assembly comprising: a first housing portion; an electric direct current activated motor mounted on said first housing portion and having positive and negative electric power contacts, said motor comprising a a rotor rotatable about an axis and including an axially projecting output shaft; manually activatable means for axially shifting said output shaft relative to said first housing portion between first and second positions; a drive member rotatably mounted on said first housing portion at an axially fixed position, said drive member being adapted to releasably engage a surgical instrument; transmission menas between said motor and said drive member coupled to said drive member, and engaged by said output shaft in either of said first and second positions for driving said drive member at a first drive ratio when said outpt shaft is in said first position, and for driving said drive member at a second drive ratio different than said first drive ratio when said output shaft is in said second position; a second housing portion; a battery mounted on said second housing portion having at least one cell and electrically positive and negative terminals; a switch assembly mounted on said second housing portion having an input lead coupled to one of said terminals, an output lead, and means including an actuator movable relative to said second housing portion between off and on positions for making an electrical connection between said input and outlet leads when said actuator is in said one position and for causing said leads to be electrically isolated from each other when said actuator is in said off position, and means for biasing said actuator to said off position; and means for affording releasable engagement between said first and second housing portions and for causing electrical contact between one of said power contacts and the output lead of said switch assembly and between the other of said power contacts and the other of said terminals.
Claim 13
Dependent Claim
181 words
A drive assembly for driving orthopedic surgical instruments, said drive assembly comprising: a housing; an electric direct current activated motor mounted on said housing and having positive and negative electric power contacts; a battery mounted on said housing having at least one cell with electrodes comprising silver and zinc oxides electrically coupled to electrically positive and negative terminals, with one of said terminals coupled to one of said contacts and potassium hydroxide electrolyte in which said electrodes are immersed to provide an electrical potential between said terminals; a switch assembly mounted on said housing having an input lead coupled to the other of said terminals, an output lead coupled to the other of said contacts, and means including an actuator movable relative to said housing between an off and an on position for making an electrical connection between said input and outlet leads when said actuator is in said on position and for causing said leads to be electrically isolated from each other when said actuator is in said off position, and means for biasing said actuator to said off position.
Claim 14
Dependent Claim
181 words
A drive assembly for driving orthopedic surgical instruments, said drive assembly comprising: a housing; an electric direct current activated motor mounted on said housing and having positive and negative electric power contacts; a battery mounted on said housing having at least one cell with electrodes comprising silver and zinc oxides electrically coupled to electrically positive and negative terminals, with one of said terminals coupled to one of said contacts and potassium hydroxide electrolyte in which said electrodes are immersed to provide an electrical potential between said terminals; a switch assembly mounted on said housing having an input lead coupled to the other of said terminals, an output lead coupled to the other of said contacts, and means including an actuator movable relative to said housing between an off and an on position for making an electrical connection between said input and outlet leads when said actuator is in said on position and for causing said leads to be electrically isolated from each other when said actuator is in said off position, and means for biasing said actuator to said off position.
Claim 15
Dependent Claim
72 words
A drive assembly according to claim 10 wherein said battery has three cells with electrodes comprising silver and zinc oxides electrically coupled to said terminal, and potassium hydroxide electrolyte in which said electrodes are immersed to provide an electical potential betweeen said terminals in the range of about 41/2 volts and provide a battery with a current output range of about 10 to 70 amps and about 14 amp hours of capacity.
Claim 16
Dependent Claim
105 words
A drive asembly according to claim 10 wherein said cell comprises walls defining a cavity, with said electrodes electrically coupled to said terminals and said liquid electrolyte within said cavity, and a vent assembly mounted in said walls, said vent assembly having a passageway between said cavity and the atmosphere, means mounted in said passageway for allowing gas in said cavity at a pressure above a predetermined level to escape through said passageway, and a curtain of micro porous polymeric material across said passageway that permits movement of gas through said curtain and passageway while restricting the movement of liquid through said curtain and passageway.
Claim 17
Dependent Claim
37 words
A drive assembly according to claim 12 wherein said battery has a plurality of cells with potassium hydroxide electrolyte in the cavities of said cells, and one of said vent assemblies connected to each of said cells.
Claim 18
Dependent Claim
12 words
A drive assembly according to claim 12 wherein said curtain comprises polytetrafluorethylene.
Claim 19
Dependent Claim
126 words
A drive assembly according to claim 10 wherein said actuator is mounted for pivotal movement about an axis between said off and on positions, includes a contact member spaced a first distance from said axis, and an actuating member projecting a second distance substantially greater than said first distance from said axis which actuating member has an outer end portion opposite said axis; said drive assembly includes a trigger mounted on said housing for movement between outer and inner positions, and means for biasing said trigger to said outer position; and said trigger engages the outer end portion of said actuating member to move said actuator from said off to said on position upon movement of said trigger from said position outer to said inner position.
Claim 20
Dependent Claim
64 words
A drive assembly according to claim 15 wherein said contact member is a conductive blade haivng a tapered edge and said switch assembly further includes opposed spring members each defining half of a generally V-shaped surface adapted to resiliently separate and frictionally receive movement of the conductive blade therebetween tapered edge first upon movement of said actuator from its off to its on position.
Claim 21
Dependent Claim
150 words
A drive assembly according to claim 10 wherein said motor comprises a rotor rotatable about an axis and including an axially projecting output shaft; and said drive assembly further includes manually activatable means for axially shifting said output shaft relative to said first housing portion between first and second positions; a drive member rotatably mounted on said first housing portion at an axially fixed position, said drive member being adapted to releasably engage a surgical instrument; and transmission means between said motor and said drive member coupled to said drive member, and engaged by said output shaft in either of said first and second positions for driving said drive member at a first drive ratio when said output shaft is in said first position, and for driving said drive member at a second drive ratio different than said first drive ratio when said output shaft is in said second position.
Claim 22
Dependent Claim
30 words
A drive assembly according to claim 17 wherein one of said drive ratios is about 5.37 to 1 and the other of said drive ratios is about 28.82 to 1.
Claim 23
Dependent Claim
141 words
A drive assembly according to claim 10 wherein said drive motor comprises a rotor rotatable about an axis and comprising a commutator, a brush holder fixed relative to said housing around said commutator, a plurality of brushes mounted on said brush holder and contacting said commutator, said brush holder having a ring of contacts alternatively connected to the battery and to the brushes, and a switch plate mounted on said first housing portion for rotational movement around said axis between first and second positions, said switch plate including means for connecting said brushes to said battery to cause rotation of said rotor in one direction when said switch plate is in said first position, and for connecting said brushes to said battery to cause rotation of said rotor in the opposite direction when said switch plate is in said second position.
Claim 24
Dependent Claim
212 words
A rechargeable battery assembly adapted for use on a drive assembly for driving orthopedic surgical instruments, which drive assembly comprises a first housing portion; and an electric direct current activated motor mounted on said first housing portion and having positive and negative electric power contacts, said battery pack comprising: a second housing portion; a battery mounted on said second housing portion having at least one cell and electrically positive and negative terminals; said cell comprising walls defining a cavity, electrodes electrically coupled to said terminals within said cavity, a liquid electrolyte within said cavity and in which said electrodes are immersed to provide an electrical potential between said terminals, and a vent assembly mounted in said walls, said vent assembly having a passageway between said cavity and the atmosphere, means mounted in said passageway for allowing gas in said cavity at a pressure above a predetermined level to escape through said passageway, and a curtain of microporous polymeric material across said passageway that permits movement of gas through said curtain and passageway while restricting the movement of liquid through said curtain and passagway; and means adapted for affording releasable engagement of said second housing portion with said first housing portion and for affording electrical contact between said power contacts and said terminals.
Claim 25
Dependent Claim
212 words
A rechargeable battery assembly adapted for use on a drive assembly for driving orthopedic surgical instruments, which drive assembly comprises a first housing portion; and an electric direct current activated motor mounted on said first housing portion and having positive and negative electric power contacts, said battery pack comprising: a second housing portion; a battery mounted on said second housing portion having at least one cell and electrically positive and negative terminals; said cell comprising walls defining a cavity, electrodes electrically coupled to said terminals within said cavity, a liquid electrolyte within said cavity and in which said electrodes are immersed to provide an electrical potential between said terminals, and a vent assembly mounted in said walls, said vent assembly having a passageway between said cavity and the atmosphere, means mounted in said passageway for allowing gas in said cavity at a pressure above a predetermined level to escape through said passageway, and a curtain of microporous polymeric material across said passageway that permits movement of gas through said curtain and passageway while restricting the movement of liquid through said curtain and passagway; and means adapted for affording releasable engagement of said second housing portion with said first housing portion and for affording electrical contact between said power contacts and said terminals.
Claim 26
Dependent Claim
69 words
A battery assembly according to claim 20 wherein said battery has three cells with electrodes comprising silver and zinc oxides electrically coupled to said terminal, and potassium hydroxide electrolyte in which said electrodes are immersed to provide an electrical potential between said terminals of about 41/2 volts and provide a battery with a current output range of about 10 to 70 amps and about 14 amp hours of capacity.
Claim 27
Dependent Claim
37 words
A battery assembly according to claim 20 wherein said battery has a plurality of cells with potassium hydroxide electrolyte in the cavities of said cells, and one of said vent assemblies connected to each of said cells.
Claim 28
Dependent Claim
12 words
A battery assembly according to claim 20 wherein said curtain comprises polytetrafluoroethylene.
Claim 29
Dependent Claim
296 words
A rechargeable battery assembly adapted for use on a drive assembly for driving orthopedic surgical instruments, which drive assembly comprises a first housing portion; and an electric direct current activated motor mounted on said first housing portion and having positive and negative electric power contacts, said battery pack comprising: a second housing portion; a battery mounted on said second housing portion having at least one cell and electrically positive and negative terminals; a switch assembly mounted on said second housing portion having an input lead coupled to one of said terminals, an output lead, and means including an actuator movable relative to said second housing portion between off and on positions for making an electrical connection between said input and outlet leads when said actuator is in said on position and for causing said leads to be electrically isolated from each other when said actuator is in said off position, and means for biasing said actuator to said off position, said actuator being mounted for pivotal movement about an axis between said off and on positions, including a contact member spaced a first distance from said axis, and an actuating member projecting a second distance substantially greater than said first distance from said axis, which actuating member has an outer end portion opposite said axis; said housing encasing said actuator and having an opening affording engagement of the outer end portion of said actuating member to move said actuator from said off to said one position; and means adapted for affording releasable engagment of said second housing portion with said first housing portion and for causing electircal contact between one of said power contacts and the output lead of said switch assembly and between the other of said power contacts and the other of said terminals.
Claim 30
Dependent Claim
296 words
A rechargeable battery assembly adapted for use on a drive assembly for driving orthopedic surgical instruments, which drive assembly comprises a first housing portion; and an electric direct current activated motor mounted on said first housing portion and having positive and negative electric power contacts, said battery pack comprising: a second housing portion; a battery mounted on said second housing portion having at least one cell and electrically positive and negative terminals; a switch assembly mounted on said second housing portion having an input lead coupled to one of said terminals, an output lead, and means including an actuator movable relative to said second housing portion between off and on positions for making an electrical connection between said input and outlet leads when said actuator is in said on position and for causing said leads to be electrically isolated from each other when said actuator is in said off position, and means for biasing said actuator to said off position, said actuator being mounted for pivotal movement about an axis between said off and on positions, including a contact member spaced a first distance from said axis, and an actuating member projecting a second distance substantially greater than said first distance from said axis, which actuating member has an outer end portion opposite said axis; said housing encasing said actuator and having an opening affording engagement of the outer end portion of said actuating member to move said actuator from said off to said one position; and means adapted for affording releasable engagment of said second housing portion with said first housing portion and for causing electircal contact between one of said power contacts and the output lead of said switch assembly and between the other of said power contacts and the other of said terminals.
Claim 31
Dependent Claim
64 words
A battery assembly according to claim 24 wherein said contact member is a conductive blade having a tapered edge and said switch assembly further includes opposed spring members each defining half of a generally V-shaped surface adapted to resiliently separate and frictionally receive movement of the conductive blade therebetween tapered edge first upon movement of said actuator from its off to its on position.
Claim 32
Dependent Claim
144 words
A drive assembly for driving orthopedic surgical instruments comprising a housing; a motor including a rotor rotatable about an axis and including an axially projecting output shaft; a manually activatable means for axially shifting said output shaft relative to said housing between first and second positions; a drive member rotatably mounted on said housing at an axially fixed position, said drive member being adapted to releasably engage a surgical instrument; and transmission means between said motor and said drive member coupled to said drive member, and engaged by said output shaft in either of said first and second positions for driving said drive member at a first drive ratio when said output shaft is in said first position, and for driving said drive member at a second drive ratio different than said first drive ratio when said output shaft is in said second position.
Claim 33
Dependent Claim
144 words
A drive assembly for driving orthopedic surgical instruments comprising a housing; a motor including a rotor rotatable about an axis and including an axially projecting output shaft; a manually activatable means for axially shifting said output shaft relative to said housing between first and second positions; a drive member rotatably mounted on said housing at an axially fixed position, said drive member being adapted to releasably engage a surgical instrument; and transmission means between said motor and said drive member coupled to said drive member, and engaged by said output shaft in either of said first and second positions for driving said drive member at a first drive ratio when said output shaft is in said first position, and for driving said drive member at a second drive ratio different than said first drive ratio when said output shaft is in said second position.
Claim 34
Dependent Claim
18 words
A drive assembly according to claim 26 wherein one of said drive ratios is about 5.37 to 1.
Claim 35
Dependent Claim
115 words
A battery comprising a cell including walls defining a cavity, electrodes electrically coupled to said terminals within said cavity, a liquid electrolyte within said cavity and in which said electrodes are immersed to provide an electrical potential between said terminals, and a vent assembly mounted in said walls, said vent assembly having a passageway between said cavity and the atmosphere, means mounted in said passageway for allowing gas in said cavity at a pressure above a predetermined level to escape through said passageway, and a curtain of microporous polymeric material entirely across said passageway that permits movement of gas through said curtain and passageway while restricting the movement of liquid through said curtain and passageway.
Claim 36
Dependent Claim
115 words
A battery comprising a cell including walls defining a cavity, electrodes electrically coupled to said terminals within said cavity, a liquid electrolyte within said cavity and in which said electrodes are immersed to provide an electrical potential between said terminals, and a vent assembly mounted in said walls, said vent assembly having a passageway between said cavity and the atmosphere, means mounted in said passageway for allowing gas in said cavity at a pressure above a predetermined level to escape through said passageway, and a curtain of microporous polymeric material entirely across said passageway that permits movement of gas through said curtain and passageway while restricting the movement of liquid through said curtain and passageway.
Claim 37
Dependent Claim
36 words
A battery according to claim 28 wherein said battery has a plurality of cells with potassium hydroxide electrolyte in the cavities of said cells, and one of said vent assemblies connected to each of said cells.
Claim 38
Dependent Claim
11 words
A battery according to claim 28 wherein said curtain comprises polytetrafluoroethylene.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-01 | 1991-08-31 | 1992-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-01 | 1995-08-31 | 1996-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-01 | 1999-08-31 | 2000-03-01 | $7700.00 | Window Closed / Lapsed |