Patent US4360738A successfully refreshed from Google Patents.
US4360738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single probe low water control
Assignee: Honeywell Inc
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Filing: 1981-05-04
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Granted: 1982-11-23
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Expires: 2001-05-04
Abstract
Abstract A timer means having a time delay on reapplication of control allows a single probe low water cutoff and feedwater makeup device to function. The time delay preventing reapplication of power to a burner while simultaneously causing a feedwater mechanism to add water to a boiler provides safe operation of the boiler without oscillations caused by momentary losses of water.
Inventors
- 👤 James I. Bartels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:47
CPC Classifications
F; F22; F22D; F22D5/00; F22D5/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
214 words
A single probe low water cutoff and makeup water control, including: probe means having a first probe element adapted to normally be in contact with water in a boiler; said probe means further having a second probe element adapted to mount said probe means in a wall of said boiler; power supply means connected to said probe means to apply an electric potential between said elements; amplifier means connected to said probe means to detect the presence or absence of water between said probe elements by measuring the presence or absence of a current flow through the boiler water caused by said potential; said amplifier means including switching means having normally open circuit means and normally closed circuit means when water is absent from said boiler; said normally open circuit means adapted to control fuel burner means for said boiler and said normally closed circuit means adapted to control makeup water means for said boiler; and time delay means responsive to said amplifier means to initiate a time delay upon said normally closed circuit means closing after once having been opened by a change in water level at said probe means, and retaining its closed state for a fixed time delay period regardless of a subsequent change in water level at said probe means.
Claim 2
Dependent Claim
214 words
A single probe low water cutoff and makeup water control, including: probe means having a first probe element adapted to normally be in contact with water in a boiler; said probe means further having a second probe element adapted to mount said probe means in a wall of said boiler; power supply means connected to said probe means to apply an electric potential between said elements; amplifier means connected to said probe means to detect the presence or absence of water between said probe elements by measuring the presence or absence of a current flow through the boiler water caused by said potential; said amplifier means including switching means having normally open circuit means and normally closed circuit means when water is absent from said boiler; said normally open circuit means adapted to control fuel burner means for said boiler and said normally closed circuit means adapted to control makeup water means for said boiler; and time delay means responsive to said amplifier means to initiate a time delay upon said normally closed circuit means closing after once having been opened by a change in water level at said probe means, and retaining its closed state for a fixed time delay period regardless of a subsequent change in water level at said probe means.
Claim 3
Dependent Claim
27 words
A single probe low water cutoff and makeup water control as described in claim 1 wherein said second probe element is in electrical contact with said boiler.
Claim 4
Dependent Claim
52 words
A single probe low water cutoff and makeup water control as described in claim 2 wherein said power supply means causes a voltage to be impressed between said probe elements that alternates in polarity; said voltage having a substantially equal electrical energy content in each polarity of the alterations of said voltage.
Claim 5
Dependent Claim
44 words
A single probe low water cutoff and makeup water control as described in claim 3 wherein said switching means includes a relay with said normally open circuit means, including normally open contact means, and said normally closed circuit means including normally closed contact means.
Claim 6
Dependent Claim
37 words
A single probe low water cutoff and makeup water control as described in claim 4 wherein said time delay means is an electric time delay means including impedance means and capacitor means to provide said time delay.
Claim 7
Dependent Claim
45 words
A single probe low water cutoff and makeup water control as described in claim 5 wherein said time delay means further includes a pair of contacts of said normally open contact means of said relay; said pair of contacts operating to initiate said time delay.
Claim 8
Dependent Claim
44 words
A single probe low water cutoff and makeup water control as described in claim 2 wherein said switching means includes a relay with said normally open circuit means including normally open contact means, and said normally closed circuit means including normally closed contact means.
Claim 9
Dependent Claim
36 words
A single probe low water cutoff and makeup water control as described in claim 7 wherein said time delay means is electric time delay means including impedance means and capacitor means to provide said time delay.
Claim 10
Dependent Claim
45 words
A single probe low water cutoff and makeup water control as described in claim 8 wherein said time delay means further includes a pair of contacts of said normally open contact means of said relay; said pair of contacts operating to initiate said time delay.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-22 | 1986-05-24 | 1986-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-22 | 1990-05-24 | 1990-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-22 | 1994-05-24 | 1994-11-23 | $7700.00 | Window Closed / Lapsed |