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US3808575A Expired / Lapsed US ⏱️ 0.0 years remaining

Cermet fixed resistor with soldered leads

Assignee: Allen Bradley Co LLC
•
Filing: 1973-04-04
•
Granted: 1974-04-30
•
Expires: 1993-04-04
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Abstract

Abstract A cermet fixed resistor having a tubular, cylindrical core of insulating ceramic material, a cermet resistive layer on the cylindrical sides of the core, low resistance layers on the core ends that are an electrical continuation of the cermet, lead wires having heads inserted with a tight fit into the core ends and also having radial collars abutting the core ends, such lead wires having a low melting solder coating along their shanks for faciliating a solder connection into an electrical circuit and having a second relatively high melting solder forming a bond between the head ends and collars with the low resistance layers on the core, and the resistor having a conformal coating of resin over the cermet that is copolymerized from the epoxy and phenolic constituents.

Inventors

  • 👤 I Brandt
  • 👤 Alten T Von

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 10:24
CPC Classifications
H; H01; H01C; H01C1/00; H01C1/14; H01C1/144

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 18 words
A resistor as in claim 1, with said low resistance terminating layer comprising a silver in glass mix.
Claim 2
Dependent Claim 75 words
A resistor as in claim 2, wherein said silver in glass mix enters the opening at each end of said cylindrical core, each lead wire head fits snugly within the silver in glass mix, and the second solder of said solder bond is dispersed between the lead wire heads and silver in glass mix within the core openings and also between the lead wire collars and the silver in glass mix on the core ends.
Claim 3
Dependent Claim 22 words
A resistor as in claim 3 wherein the lead wire heads are knurled and in an interference fit with the core openings.
Claim 4
Dependent Claim 34 words
A resistor as in claim 1, wherein the low melting solder is substantially 60 percent lead and 40 percent tin, and the high melting solder is substantially 90 percent lead and 10 percent tin.
Claim 5
Dependent Claim 29 words
A resistor as in claim 2 in which the silver in glass mix contains palladium of 20 percent by weight or less of the silver, glass and palladium content.
Claim 6
Dependent Claim 24 words
A resistor as in claim 1 having a synthetic coating of copolymerized epoxy resin and phenolic resin surrounding the layer of cermet resistance material.
Claim 7
Dependent Claim 23 words
A resistor as in claim 7 having a thin glaze of glass interposed between the cermet resistance material and the copolymerized synthetic coating.
Claim 8
Dependent Claim 51 words
A resistor as in claim 2 having a nickel film over the silver in glass mix and a silver film over the nickel before bonding of the higher melting solder, and a bond combining the solder, nickel and silver of the silver in glass mix upon heating the higher melting solder.
Claim 9
Dependent Claim 23 words
A resistor as in claim 7 having an outer jacket of epoxy resin surrounding the synthetic coating of copolymerized epoxy and phenolic resins.

References Cited (Backward Citations)

US2455136A Cited
US2658980A Cited
US2997979A Cited
US3064070A Cited
US3616981A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-04-29 1977-10-29 1978-04-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-04-29 1981-10-29 1982-04-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-04-29 1985-10-29 1986-04-30 $7700.00 Window Closed / Lapsed

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