US3639675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laminated glass stem and method of making same
Assignee: Hitachi Ltd
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Filing: 1969-09-24
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Granted: 1972-02-01
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Expires: 1989-09-24
Abstract
Abstract A stem having a metal cylinder, at least one metal lead extending through the cylinder, a glass body interposed between the cylinder and the lead for supporting the lead, electrically insulated from the cylinder, and a glass layer having a surface of greater resistivity than that of the glass body and covering at least a portion of the surface of the glass body so as to prevent a reduction of insulation resistance between the lead and the cylinder.
Inventors
- 👤 Yoku Kaino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:42
CPC Classifications
H; H10; H10W; H10W76/00; H10W76/10; H10W76/12; H10W76/13; H10W76/132; C; C03; C03C; C03C29/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
157 words
A stem comprising an annular member of metal selected from the group consisting of iron and alloys containing iron as a principal ingredient, a lead of metal selected from the group consisting of iron and alloys containing iron essentially, said lead extending through said annular member, and a glass body disposed in the space between said annular member and said lead so as to make a firm bond with the inner wall of said annular member and the outer periphery of said lead, said glass body being in the form of a stack of a soda lime glass layer and a borosilicate glass layer containing alkaline components in a total amount of less than about 10 percent and sodium oxides in an amount of less than about 5 percent, said borosilicate glass layer having a thickness smaller, a volume and surface resistivity greater, and a working point higher than those of said soda lime glass layer, respectively.
Claim 2
Dependent Claim
157 words
A stem comprising an annular member of metal selected from the group consisting of iron and alloys containing iron as a principal ingredient, a lead of metal selected from the group consisting of iron and alloys containing iron essentially, said lead extending through said annular member, and a glass body disposed in the space between said annular member and said lead so as to make a firm bond with the inner wall of said annular member and the outer periphery of said lead, said glass body being in the form of a stack of a soda lime glass layer and a borosilicate glass layer containing alkaline components in a total amount of less than about 10 percent and sodium oxides in an amount of less than about 5 percent, said borosilicate glass layer having a thickness smaller, a volume and surface resistivity greater, and a working point higher than those of said soda lime glass layer, respectively.
Claim 3
Dependent Claim
55 words
A stem as claimed in claim 1, in which a cap member of metal is fitted on the outer peripheral wall of said annular member on the side at which said soda lime glass layer is exposed so as to enclose the exposed surface of said soda lime glass layer within a predetermined fluidtight space.
Claim 4
Dependent Claim
152 words
A capsule comprising an annular member of metal, at least one elongated lead of metal extending through said annular member, a glass body disposed in the space between said annular member and said lead so as to make a firm bond with the inner wall of said annular member and the outer periphery of said lead, a cap member engaging the outer peripheral wall of said annular member to define a fluidtight space adjacent to a portion of said lead and a portion of said glass body, and a glass layer covering the portion of said glass body which is exposed to air, said glass layer containing alkaline components in a total amount of less than about 10 percent and sodium oxides in an amount of less than about 5 percent and having a volume resistivity greater, a surface resistivity greater and a working point higher than those of said glass body.
Claim 5
Dependent Claim
152 words
A capsule comprising an annular member of metal, at least one elongated lead of metal extending through said annular member, a glass body disposed in the space between said annular member and said lead so as to make a firm bond with the inner wall of said annular member and the outer periphery of said lead, a cap member engaging the outer peripheral wall of said annular member to define a fluidtight space adjacent to a portion of said lead and a portion of said glass body, and a glass layer covering the portion of said glass body which is exposed to air, said glass layer containing alkaline components in a total amount of less than about 10 percent and sodium oxides in an amount of less than about 5 percent and having a volume resistivity greater, a surface resistivity greater and a working point higher than those of said glass body.
Claim 6
Independent Claim
175 words
A method of making a stem comprising the steps of preparing an annular member of metal, passing an elongated lead through said annular member, disposing a first glass block having a relatively high first working point and a relatively high-volume resistivity and surface resistivity at a position adjacent to the space defined between said lead and said annular member, said first glass block containing alkaline components in a total amount of less than about 10 percent and sodium oxides in an amount of less than about 5 percent, disposing a second glass block having a relatively low second working point and a relatively low volume resistivity and a surface resistivity on said first glass block and within said space, and maintaining the structure thus obtained at a temperature in the vicinity of said first working point for fusing both said glass blocks thereby to ensure a firm bond between said glass blocks and said annular member and said lead and to fix said lead in spaced relation from the inner wall of said annular member.
Claim 7
Independent Claim
175 words
A method of making a stem comprising the steps of preparing an annular member of metal, passing an elongated lead through said annular member, disposing a first glass block having a relatively high first working point and a relatively high-volume resistivity and surface resistivity at a position adjacent to the space defined between said lead and said annular member, said first glass block containing alkaline components in a total amount of less than about 10 percent and sodium oxides in an amount of less than about 5 percent, disposing a second glass block having a relatively low second working point and a relatively low volume resistivity and a surface resistivity on said first glass block and within said space, and maintaining the structure thus obtained at a temperature in the vicinity of said first working point for fusing both said glass blocks thereby to ensure a firm bond between said glass blocks and said annular member and said lead and to fix said lead in spaced relation from the inner wall of said annular member.
Claim 8
Dependent Claim
29 words
A method as claimed in claim 4, in which said first glass block is made of Kovar glass and said second glass block is made of soda lime glass.
Claim 9
Dependent Claim
108 words
A stem comprising an annular member of metal, at least one elongated conductive lead extending through said annular member, a glass body disposed in the space between and in intimate contact with said annular member and said lead, and a glass layer covering at least a portion Of the surface of said glass body to prevent a reduction of insulation resistance between said lead and said annular member, said glass layer having a surface resistivity greater than that of said glass body and containing alkaline components in a total amount of less than about 10 percent and sodium oxides in an amount of less than about 5 percent.
Claim 10
Dependent Claim
108 words
A stem comprising an annular member of metal, at least one elongated conductive lead extending through said annular member, a glass body disposed in the space between and in intimate contact with said annular member and said lead, and a glass layer covering at least a portion Of the surface of said glass body to prevent a reduction of insulation resistance between said lead and said annular member, said glass layer having a surface resistivity greater than that of said glass body and containing alkaline components in a total amount of less than about 10 percent and sodium oxides in an amount of less than about 5 percent.
Claim 11
Dependent Claim
39 words
The stem as claimed in claim 6 wherein said glass body is constructed of a material having a coefficient of thermal expansion substantially equivalent to those of said annular member and said lead and demonstrates a good wettability therewith.
Claim 12
Dependent Claim
43 words
The stem as claimed in claim 6 wherein said glass layer is a low alkali glass containing alkaline components in a total amount of less than about 6 percent and a sodium oxide component in an amount of less than about 0.15 percent.
Claim 13
Dependent Claim
39 words
The stem as claimed in claim 8 wherein said alkaline components are present in a total amount of less than about 0.56 percent and the sodium oxide component is present in an amount of less than about 0.05 percent.
Claim 14
Dependent Claim
31 words
The stem as claimed in claim 6 wherein contact between said annular member and said glass layer is minimized to obviate problems arising from differences in their coefficients of thermal expansion.
References Cited (Backward Citations)
CA749540A
Cited
US3351700A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |