Patent US3685732A successfully refreshed from Google Patents.
US3685732A
Expired / Lapsed
US
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Thermostatic control device with heat motor operated step open diaphragm valve
Assignee: Robertshaw Controls Co
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Filing: 1970-06-03
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Granted: 1972-08-22
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Expires: 1990-06-03
Abstract
Abstract A control device for burner apparatus having a differential pressure operated diaphragm valve controlled by an internal bleed system which is subject to pressure regulation and to on-off control by sequentially operated bypass and bleed valves which are actuated by a heat motor operator. Initial actuation of the heat motor operator opens the bleed valve to provide a step input at a reduced rate under pressure regulation to the main burner for assuring good ignition without ''''roll-out.'''' Subsequent control of the bypass valve enables flow modulation, and full input is delayed until the bypass valve is fully closed.
Inventors
- 👤 Lauren D Haskins
- 👤 Samuel T Kelly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:13
CPC Classifications
F; F23; F23N; F23N1/00; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781; Y10T137/7782; Y10T137/8593; Y10T137/86928
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
341 words
In a control system for supplying a fuel flow to burner apparatus, the combination comprising a casing having inlet and outlet means, differential pressure operated diaphragm valve means mounted in said casing betweEn said inlet and outlet means and operatively movable between a plurality of flow positions, said diaphragm valve means cooperating with a wall of said casing to define an operating pressure chamber whereby pressure variations therein cause operation of said diaphragm valve means, a bleed chamber communicating with said operating pressure chamber and having first and second ports, a primary bleed flow passage between said inlet means and said bleed chamber, a secondary bleed flow passage between said inlet means and said first port, bleed line means between said second port and said outlet means, bypass valve means cooperating with said first port to control a bleed flow through said secondary bleed flow passage into said bleed chamber, bleed valve means cooperating with said second port to control a bleed flow through said bleed line means from said bleed chamber, lever means mounted within said bleed chamber and cooperating with said bypass valve means and said bleed valve means and having an off position wherein said bypass valve means is open and said bleed valve means is closed, an on position wherein said bypass valve means is closed and said bleed valve means is open, and a modulating range of positions extending from said off position to said on position wherein said bypass valve is open to a degree dependent upon the particular position of said lever means in said modulating range and said bleed valve means is open, thermostat means, and heat motor means operatively connected with said thermostat means and said lever means and responsive to a modulated demand from said thermostat means to effect movement of said lever means between said off, modulating and on positions whereby said diaphragm valve means is moved from an off position to a step flow position and thereafter is modulated between the step flow position and a full flow position.
Claim 2
Dependent Claim
341 words
In a control system for supplying a fuel flow to burner apparatus, the combination comprising a casing having inlet and outlet means, differential pressure operated diaphragm valve means mounted in said casing betweEn said inlet and outlet means and operatively movable between a plurality of flow positions, said diaphragm valve means cooperating with a wall of said casing to define an operating pressure chamber whereby pressure variations therein cause operation of said diaphragm valve means, a bleed chamber communicating with said operating pressure chamber and having first and second ports, a primary bleed flow passage between said inlet means and said bleed chamber, a secondary bleed flow passage between said inlet means and said first port, bleed line means between said second port and said outlet means, bypass valve means cooperating with said first port to control a bleed flow through said secondary bleed flow passage into said bleed chamber, bleed valve means cooperating with said second port to control a bleed flow through said bleed line means from said bleed chamber, lever means mounted within said bleed chamber and cooperating with said bypass valve means and said bleed valve means and having an off position wherein said bypass valve means is open and said bleed valve means is closed, an on position wherein said bypass valve means is closed and said bleed valve means is open, and a modulating range of positions extending from said off position to said on position wherein said bypass valve is open to a degree dependent upon the particular position of said lever means in said modulating range and said bleed valve means is open, thermostat means, and heat motor means operatively connected with said thermostat means and said lever means and responsive to a modulated demand from said thermostat means to effect movement of said lever means between said off, modulating and on positions whereby said diaphragm valve means is moved from an off position to a step flow position and thereafter is modulated between the step flow position and a full flow position.
Claim 3
Dependent Claim
17 words
The invention as recited in claim 1 wherein said lever means includes a pivotally mounted lever arm.
Claim 4
Dependent Claim
37 words
The invention as recited in claim 2 wherein said bypass valve means is mounted within said bleed chamber adjacent a free end of said lever arm for selective engagement therewith to open and close said first port.
Claim 5
Dependent Claim
66 words
The invention as recited in claim 1 wherein said first port comprises an annular seat, and wherein said bypass valve means comprises a bypass valve member disposed on a side of said annular seat, a retaining disc disposed on an other side of said annular seat, and a valve stem concentrically disposed within said annular seat and connecting said bypass valve member with said retaining disc.
Claim 6
Dependent Claim
46 words
The invention as recited in claim 4 wherein said bypass valve means further comprises spring means mounted in compression between said other side of said annular seat and said retaining disc whereby said bypass valve means is biased in a direction to close said first port.
Claim 7
Dependent Claim
21 words
The invention as recited in claim 1 wherein said primary and secondary bleed flow passages each have flow restriction means therein.
Claim 8
Dependent Claim
26 words
The invention as recited in claim 1 wherein said first and second ports comprise annular seats axially displaced from each other and lying in parallel planes.
Claim 9
Dependent Claim
29 words
The invention as recited in claim 1 wherein said bypass valve means and said bleed valve means are mounted upstream of said first port and said second port, respectively.
Claim 10
Dependent Claim
33 words
The invention as recited in claim 1 wherein said second port comprises an annular seat, and wherein said bleed valve means comprises a flat, flexible bleed valve member mounted on said lever means.
Claim 11
Dependent Claim
72 words
The invention as recited in claim 9 wherein said lever means includes a pivotally mounted lever arm exhibiting limited flexure, and wherein said bleed valve member is mounted upstream of said second port such that a pressure differential is established across said bleed valve means whenever said second port is closed, said pressure differential acting to maintain said second port closed whereby said lever means moves from sAid off position with snap-action.
Claim 12
Dependent Claim
18 words
The invention as recited in claim 1 wherein said heat motor means is mounted within said bleed chamber.
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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) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |