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US2853873A Expired / Lapsed US ⏱️ 0.0 years remaining

Field calibrator for combustible gas analyzer

Assignee: MSA Safety Inc
•
Filing: 1955-10-14
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Granted: 1958-09-30
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Expires: 1975-10-14
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Abstract

No abstract record available.

Inventors

  • 👤 Robert C Hollobaugh
  • 👤 John P Strange

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 14:44
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/0004; G01N33/0006; H; H04; H04R; H04R3/00; H04R3/002

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

US1844843A Cited
US2308400A Cited
US2310472A Cited
US2335032A Cited
US2534489A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1961-09-29 1962-03-31 1962-09-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1965-09-29 1966-03-31 1966-09-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1969-09-29 1970-03-31 1970-09-30 $7700.00 Window Closed / Lapsed

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