US3620658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fail-safe fuel cutoff device
Assignee: Individual
•
Filing: 1970-04-09
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Granted: 1971-11-16
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Expires: 1990-04-09
Abstract
Abstract A fail-safe safety fuel cutoff system for heating equipment fueled with pressurized gas, such as LPG, hazardous to life if accidentally escaping into an enclosure. The system utilizes a main cutoff valve of the pilot-controlled type and equipped with an operating solenoid normally energized by a thermocouple having its hot junction exposed to the burner. In one preferred embodiment, a reserve quantity of fuel is automatically stored adequate to operate the burner to energize the thermocouple and open the cutoff valve whereas, in a second embodiment, a secondary power source is utilized initially to hold the main valve open until the thermocouple reaches its operating temperature and assumes control of the cutoff valve. Each embodiment is effective to positively cut off all fuel flow at a point exteriorly of the enclosure following cooling of the thermocouple.
Inventors
- 👤 Charles L Tappin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:54
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/02; F23N5/10; F23N5/105; F23N2235/00; F23N2235/12; F23N2235/20; F23N2235/24
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
154 words
In a fail-safe fuel supply system for a manually controlled main burner located in an enclosure and supplied with gaseous fuel through a fuel conductor from a pressure-regulated main supply exteriorly of the enclosure, that improvement which comprises: normally closed automatic safety cutoff means controlling said fuel supply to said burner and including pilot valve means effective when energized to effect the opening of main valve means controlling the flow of fuel to said burner, thermally responsive means positioned to be heated solely by said burner and effective when heated by gas supplied to said burner to energize said pilot valve means to open said main valve means, and means including manually operated means for supplying gaseous fuel to said main burner temporarily from gas trapped between said cutoff means and manually operated means and in sufficient quantity to bring said thermally responsive means to a temperature adequate to energize said pilot valve means.
Claim 2
Dependent Claim
154 words
In a fail-safe fuel supply system for a manually controlled main burner located in an enclosure and supplied with gaseous fuel through a fuel conductor from a pressure-regulated main supply exteriorly of the enclosure, that improvement which comprises: normally closed automatic safety cutoff means controlling said fuel supply to said burner and including pilot valve means effective when energized to effect the opening of main valve means controlling the flow of fuel to said burner, thermally responsive means positioned to be heated solely by said burner and effective when heated by gas supplied to said burner to energize said pilot valve means to open said main valve means, and means including manually operated means for supplying gaseous fuel to said main burner temporarily from gas trapped between said cutoff means and manually operated means and in sufficient quantity to bring said thermally responsive means to a temperature adequate to energize said pilot valve means.
Claim 3
Dependent Claim
57 words
A fail-safe fuel supply system as defined in claim 1 characterized in that said manually controlled means includes means for energizing said pilot valve means for a brief interval from a separate power source and for thereafter energizing said pilot valve means from said thermally responsive means so long as the same remains heated from said burner.
Claim 4
Dependent Claim
41 words
A fail-safe fuel supply system as defined in claim 1 characterized in that said manually controlled means includes switch-controlled auxiliary power means manually operable to energize said pilot valve means while said thermally responsive means is being heated by said burner.
Claim 5
Dependent Claim
46 words
A fail-safe fuel supply system as defined in claim 3 characterized in that said manually controlled means for said auxiliary power means includes means for automatically deactivating the connection to said auxiliary power means and for energizing said pilot valve means from said thermally responsive means.
Claim 6
Dependent Claim
45 words
A fail-safe fuel supply system as defined in claim 3 characterized in that manually controlled means comprise double-pole single-throw switch means normally spring biased to a position deactivating said auxiliary power means and connecting said thermally responsive means in circuit with said pilot valve means.
Claim 7
Dependent Claim
44 words
A fail-safe fuel supply system as defined in claim 5 characterized in the provision of signal means operatively connected with said switch means and effective to provide a distinctive indication when said auxiliary power means is in use to energize said pilot valve means.
Claim 8
Dependent Claim
73 words
A fail-safe fuel supply system as defined in claim 1 characterized in that said means for supplying fuel to said burner temporarily to heat said thermally responsive means to a temperature effective to energize said pilot valve means includes reserve fuel storage means of limited capacity located in the fuel connection between said main valve and said burner and automatically charged to capacity as an incident to the opening of said main valve.
Claim 9
Dependent Claim
52 words
A fail-safe fuel supply system as defined in claim 7 characterized in that said reserve fuel supply means includes means for maintaining the reserve supply of fuel under pressure as the same is being supplied to and burned at said burner to bring said thermally responsive means up to its operating temperature
Claim 10
Dependent Claim
27 words
A fail-safe fuel supply system as defined in claim 7 characterized in that said reserve fueL storage means is a unitary part of said safety cutoff means.
Claim 11
Dependent Claim
34 words
A fail-safe fuel supply system as defined in claim 7 characterized in that said safety cutoff means is a unitary assembly having a housing formed with a chamber enclosing said reserve fuel storage means.
Claim 12
Dependent Claim
101 words
A fail-safe fuel supply system as defined in claim 7 characterized in that said reserve fuel storage means comprises chamber means enclosing a balloon of resilient material having an inlet sealed to a passage in direct communication with the fuel flow passage extending between said main valve and said burner, said balloon being normally held expanded against the interior of said chamber means by the normal fuel pressure, and the energy stored in said expanded balloon being effective when the fuel therein is being burned at said burner to contract and maintain pressure on the diminishing quantity of reserve fuel therein.
Claim 13
Dependent Claim
113 words
A fail-safe fuel cutoff valve comprising a main housing provided with a diaphragm-supported main valve cooperating with seat means positioned to control the flow of gaseous fuel between an inlet and an outlet passage, solenoid-operated pilot valve means controlling the flow of fuel between said inlet passage and the remote side of the diaphragm and a vent to the atmosphere and operable to hold said main valve in one extreme position thereof when energized and in a second extreme position when deenergized, and resilient balloon means enclosed in said housing and in communication with said outlet passage operable to store a reserve quantity of gaseous fuel therein when said main valve is open.
Claim 14
Dependent Claim
113 words
A fail-safe fuel cutoff valve comprising a main housing provided with a diaphragm-supported main valve cooperating with seat means positioned to control the flow of gaseous fuel between an inlet and an outlet passage, solenoid-operated pilot valve means controlling the flow of fuel between said inlet passage and the remote side of the diaphragm and a vent to the atmosphere and operable to hold said main valve in one extreme position thereof when energized and in a second extreme position when deenergized, and resilient balloon means enclosed in said housing and in communication with said outlet passage operable to store a reserve quantity of gaseous fuel therein when said main valve is open.
Claim 15
Dependent Claim
34 words
A fail-safe fuel cutoff valve as defined in claim 12 characterized in that a portion of said housing enclosing said resilient balloon is detachable to provide access to said balloon for servicing the same.
Claim 16
Dependent Claim
57 words
A fail-safe fuel cutoff valve as defined in claim 12 characterized in the provision of valve-controlled means on the downstream side of said main valve and in communication with said balloon means operable to trap said reserve quantity of fuel in said balloon means when said pilot valve closes said atmospheric vent thereby closing said main valve.
Claim 17
Dependent Claim
52 words
A fail-safe fuel supply system as defined in claim 1 characterized in that the capacity of said fuel conductor between said cutoff means and said manually controlled means is adequate when burned at said main burner to activate said thermally responsive means to energize said pilot valve to open said cutoff means.
Claim 18
Dependent Claim
20 words
A fail-safe fuel supply system as defined in claim 15 characterized in that said thermally responsive means includes thermocouple means.
Claim 19
Dependent Claim
36 words
A fail-safe fuel supply system as defined in claim 1 characterized in the provision of auxiliary means for energizing said pilot valve means temporarily independently of said thermally responsive means while the latter is being heated.
Claim 20
Dependent Claim
23 words
A fail-safe fuel supply system as defined in claim 1 characterized in that said fuel supply comprises a tank of liquid petroleum fuel.
Claim 21
Dependent Claim
48 words
A fail-safe fuel supply system as defined in claim 1 characterized in that said system is fully self contained and independent of public utility fuel and electrical supplies and in which said thermally responsive means comprises thermocouple means and said fuel supply comprises a tank of liquid petroleum.
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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) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |