US3458269A - Pneumatic control system and parts therefor or the like - Google Patents

Description

July 29, 1969 c, PERKlNs ET AL 3,458,269

PNEUMATIC CONTROL SYSTEM AND PARTS THEREFOR OR THE LIKE Filed July 11, 1967 2 Sheets-Sheet l INVENTORS CHARLES H PERKINS KENNETH G. KREUTER THEIR AT TORNE YS July 29, 1969 c. H. PERKlNS ETAL 3,458,269

PNEUMATIC CONTROL SYSTEM AND PARTS THEREFOR OR THE LIKE Filed July 11, 1967 2 Sheets-Sheet 2 IOA INVENTORS CHARLES H. PERKINS KENNETH GKREUTER THEIR ATTORNEYS United States Patent 3,458,269 PNEUMATIC CONTROL SYSTEM AND PARTS THEREFOR OR THE LIKE Charles H. Perkins, Richmond, Va., and Kenneth G. Kreuter, Goshen, Ind., assignors to Robertslraw Controls Company, Richmond, Va., a corporation of Delaware Filed July 11, 1967, Ser. No. 652,440 Int. Cl. F23g 9/08; Gd 23/185 US. Cl. 431-58 20 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a pneumatic control system for a burner means or the like and to improved parts for such a system or the like.

It is well known that the operation of a fuel burning burner means for an oven or the like can be controlled by a safety valve means which will only open to permit fuel to flow to the burner means when a certain flame means exists at a pilot burner means and will close to prevent fuel flow to the main burner means when the certain flame means ceases to exist at the pilot burner means, the flow of fuel to the pilot burner means being manually or thermostatically controlled.

Accordingly, one feature of this invention is to pneu' matically control such a safety valve means or the like.

In particular, the embodiments of this invention provide a pneumatically operated actuator means having tubular passage means interconnecting the actuating chamber of the actuator means to a vacuum source and to the atmosphere. A condition responsive means forms part of the tubular passage means and includes a member disposed in that part of the tubular passage means to be expanded and contracted relative to the expansion and contraction of the tubular passage means by certain conditions to respectively block and unblock that part of the passage means leading to either the vacuum source or to the atmosphere to cause the actuator means to move between its operating positions as will be apparent hereinafter.

Accordingly, it is an object of this invention to provide an improved pneumatic system having one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide an improved condition responsive means for such a system or the like.

Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIGURE 1 is a schematic view illustrating a pneumatic control system of this invention.

FIGURE 1A is an enlarged fragmentary view of the condition responsive means for the system of FIGURE 1.

FIGURE 2 is a view similar to FIGURE 1 and illustrates the system in another operating position thereof.

FIGURE 2A is a view similar to FIGURE 1A and illustrates the condition responsive means in the operating condition of FIGURE 2.

FIGURE 3 is a view similar to FIGURE 1 and illustrates another pneumatic control system of this invention.

FIGURE 3A is a view similar to FIGURE 1A and illustrates the condition responsive means for the system of FIGURE 3.

FIGURE 4 is a view similar to FIGURE 3 and illustrates the pneumatic system of FIGURE} in another operating position thereof.

FIGURE 4A is a view similar to FIGURE 3A and illustrates the condition responsive means in the operating condition of FIGURE 4.

While the various features of this invention are hereinafter described and illustrated as being particularly adaptable for providing a pneumatic control system for an oven burner means or the like, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide control means for other devices as desired.

Therefore, this invention is not to be limited to only the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIGURE 1, the improved pneumatic control system of this invention is generally indicated by the reference numeral 10 and comprises a main burner means 11 for an oven or the like adapted to be interconnected to a fuel source conduit 12 by a control device 13 and a pneumatically operated safety valve means or actuator 14 in a manner hereinafter described, the fuel source conduit 12 being interconnected to a continuously burning standby pilot burner 15 by a conduit 16.

The control device 13 can comprise a manually operated and temperature responsive valve means well known in the art which when disposed in the on position thereof will interconnect the fuel source conduit 12 to a conduit 17 leading to an inlet means 18 of the safety valve means 14, the control device 13 preventing fluid communication between the fuel source conduit 12 and the conduit 17 when the oven or the like reaches the selected temperature.

The safety valve means or actuator 14 includes a housing means 19 having an outlet means 20 separated from the inlet means 18 by a valve seat 2'1 opened and closed by a valve member 22, the valve member 22 being carried by a flexible diaphragm 23 that cooperates with the housing means 19 to define a chamber 24.

A heater or controller pilot burner means 25 is disposed adjacent the standby pilot means 15 and is interconnected to the inlet means 18 of the safety valve means 14 by a conduit 26 at a point upstream from the valve seat 21 whereby when the control valve 13 is opened to interconnect the fuel source conduit 12 to the inlet 18 ofthe safety valve 14, fuel is directed by the conduit 26 to the pilot burner 25 so that the fuel issuing therefrom will be ignited by the continuously burning standby pilot 15. However, when the control valve means 13, either manually and/or thermostatically closes, the flow of fuel through the conduit 26 is terminated and the flame at the heater pilot 25 is extinguished in a manner well known in the art.

The chamber 24 of the safety valve means 14 is fluidly interconnected to a tubular passage means, generally indicated by the reference numeral 27, which comprises a first part 28 leading to the inlet side of a vacuum pump or vacuum source 29 while another part 30 of the tubular passage means 27 leads to the atmosphere at the free end means 31 thereof for a purpose hereinafter described.

The part 28 of the passage means 27 has a restriction means 32 therein for a purpose hereinafter described.

The part 30 of the passage means 27 has a condition responsive means 33 defining the end means 31 thereof and now to be described.

As illustrated in FIGURES 1 and 1A, the condition responsive means 33 comprises a tubular member or element 34 having opposed ends 35 and 36, the end 36 of the tubular member 34 being exposed to the atmosphere and the end 35 of the tubular member 34 being telescoped over the adjacent end 37 of the conduit part 30 so as to be in sealed fluid communication therewith. A solid rod-like or cylindrical member 38 is disposed within the tubular member 34 and is confined between the opposed ends 35 and 36 thereof by inwardly directed annular beads 39 deformed inwardly in the tubular member 34 in any suitable manner.

The tubular member 34 and the solid member 38 disposed therein are selected from particular materials and of particular sizes so that when the member 38 is heated by flame means at the heater pilot 25, the member 38 expands at a greater rate than the rate of expansion of the tubular member 34 to completely block and seal closed the tubular member 34 between the opposed ends 35 and 36 thereof in the manner illustrated in FIGURE 1A so that the atmosphere will not be interconnected to the chamber 24 of the pneumatically operated safety valve 14 for the purpose hereinafter described.

Conversely, when the flame means at the heater pilot 25 ceases to exist, the cooling of the member 38 in the tubular member 34 causes the member 38 to contract at a rate greater than the rate of contraction of the tubular member 34 in the manner illustrated in FIGURE 2A to unblock the tubular member 34 and permit the atmosphere at the end 36 of the tubular member 34 to be interconnected to the chamber 24 of the actuator 14 through the part 30 of the passage means 27 for a purpose hereinafter described.

The valve member 22 is normally urged to its closed position by a compression spring 40 disposed in the chamber 24 and having one end 41 thereof bearing against the housing means 19 and the other end 42 thereof bearing against a backup plate 43 carried by the flexible diaphragm 23.

The operation of the control system and the condition responsive means 33 of this invention will now be described.

When the control valve 13, either manually or thermostatically, is preventing the fuel source conduit 12 from being fluidly connected to the inlet 18 of the safety valve 14 in the manner illustrated in FIGURE 2, no fuel is flowing to the heater pilot means 25 whereby no flame means at the heater pilot 25 is being sensed by the condition responsive means 33 and the member 38 thereof 'is in its contracted condition in the manner illustrated in FIGURE 2A to permit the chamber 24 of the safety valve means 14 to be interconnected to the atmosphere. Since the vacuum pump 29 is continuously operating and is continuously tending to evacuate the chamber 24, the restriction means 32 in the part 28 of the passage means 27 is of such a size that the vacuum pump 29 cannot evacuate the chamber 24 at a rate sufficient to overcome the force of the compression spring 40 when the condition responsive means 33 is in the position illustrated in FIG- URE 2A whereby the force of the compression spring 40 maintains the valve member 22 against the valve seat 21 to completely close off the inlet 18 of the safety valve means 14 from the outlet means thereof. In this manner, the main burner means 1'1 is in its off condition as no fuel can flow therethrough.

However, when the control device 13, either manual- 1y or thermostatically, directs the fuel source conduit 12 to the inlet 18 of the safety valve means 14, the flow of fuel to the inlet 18 passes through the conduit 26 to the heater pilot and be ignited by the standby pilot 15.

Therefore, even though the valve member 22 is in its closed position to prevent the fuel entering the inlet 18 of the safety valve means 14 from reaching the main burner means 11, the heater pilot 25 is now burning whereby the condition responsive means 33 senses the existence of the flame means at the heater pilot 25. The heated member 38 expands to completely block th tubular element 34 between its opposed ends 35 and 36 so that the atmosphere is no longer interconnected to the chamber 24. Since the atmosphere is no longer connected to the chamber 24, the continuously operating vacuum pump 29 can now evacuate the chamber 24 whereby the subsequent pressure differential created across the flexible diaphragm 23 causes the diaphragm 23 to move upwardly in opposition to the force of the compression spring 40 and open the valve seat 21 in the manner illustrated in FIGURE 1 so that the fuel passing into the inlet 18 of the safety valve means 14 can now pass out of the outlet means 20 thereof to the main burner means 11 and be ignited by the standby pilot 15 and/ or heater pilot 25.

The control system 10 remains in the operating position illustrated in FIGURE 1 as long as the control device 13 permits fuel to flow to the heater pilot burner means 25 to maintain its flame means. However, should the control device 13 close the source conduit 12 from the conduit 17, such as when the temperature effect of the main burner 11 reaches the selected temperature effect, the safety valve means 14 will close to the position illustrated in FIGURE 2 in the manner previously described until the control device 13 again directs fuel to the heater pilot 25.

Therefore, it can be seen that the control system 10 of this invention provides a pneumatically operated actuator means 14 being interconnected by tubular passage means 27 to a vacuum source 29 and to the atmosphere, the passage defining means 27 having a condition responsive means 33 therein which prevents the actuator 14 from being interconnected to the atmosphere when the condition responsive means 33 senses flame means at the heater pilot 25 so that the vacuum source 29 can move the actuator 14 to the operating position illustrated in FIG- URE 1 and which will interconnect the actuator 14 to the atmosphere when no flame exists at the heater pilot 25 in the manner illustrated in FIGURE 2 so that the atmosphere will cause the actuator 14 to move to the operating position of FIGURE 2.

Further, it can be Seen that if the source of vacuum is lost, the condition responsive means is broken off or the pilot flame is not present, the vacuum in the actuator chamber is replaced by the atmosphere whereby the compression spring in the actuator chamber will close the safety valve and prevent operation of the main burner.

Another control system and condition responsive means of this invention are illustrated in FIGURES 3, 3A, 4 and 4A and are generally indicated respectively by the reference numerals 10A and 33A, the parts of the system 10A and condition responsive means 33A similar to the previously described system 10 and condition responsive means 33 are indicated by like reference numerals followed by the reference letter A.

As illustrated in FIGURE 3, the control system 10A of this invention includes the previously described safety valve means or actuator 14A being adapted to interconnect its inlet means 18A to its outlet means 20A leading to the main burner means 11A when the valve member 22A is moved to its opened position as illustrated in FIGURE 3 and to prevent such fluid communication when the valve member 22A is moved to its closed position as illustrated in FIGURE 4.

However, the chamber means 24A of the actuator or safety valve means 14A has the part 28A of the previously described tubular passage means 27A directly interconnected to the atmosphere at the end 48 thereof and the part 28A has an orifice or restriction means 44 disposed therein to restrict such communication as will be apparent hereinafter. The part 30A of the tubular passage means 27A has its end 37A telescopically received in the end 35A of the tubular member or element 34A while a third part 45 of the passage defining means 27A of the system A has an end 46 thereof telescopically and sealingly received in the end 36A of the tubular member or element 34A. The other end 47 of the part 45 is interconnected to the inlet means of a vacuum source means 29A, such asa vacuum pump or the like.

In addition, the solid cylindrical rod-like member 38A and the tubular member 34A have reverse expansion and contraction properties from the solid member 38 and tubular member 34 previously described.

In particular, the member 38A of the condition responsive means 33A expands at a rate less than rate of expansion of the tubular member 34A to the position illustrated in FIGURE 3A when heated by the flame means at the controller pilot burner means 25A to unblock the tubular member 34A and contracts at a rate less than rate of contraction of the tubular member 34A to block the tubular member 34A in the manner illustrated in FIG- URE 4A when no flame exists at the tubular pilot burner means 25A as illustrated in FIGURE 4.

The operation of the control system 10A as illustrated in FIGURES 3 and 4 will now be described.

When the control device 13A either manually or thermostatically prevents fluid communication between the fuel source conduit 12A and the inlet means 18A of the safety valve means 14A, no fuel is flowing to the pilot burner means 25A so that the condition responsive means 13A senses the non-existence of the flame means at the pilot burner means 25A. In this manner, the cooled members 38A and 34A of the condition responsive means 33A contract to completely block the tubular member 34A in the manner illustrated in FIGURE 4A whereby the condition responsive means 33A prevents communication between the chamber 24A of the safety valve or actuator 14A and the inlet of the vacuum pump 29A.

However, the chamber 24A is interconnected to the atmosphere through the part 28A of the passage defining means 27A so that as the chamber 24A returns to atmospheric conditions, the compression spring 40A moves the valve member 22A against the valve seat 21A in the manner illustrated in FIGURE 4 to prevent fuel flow to the main burner means 11A.

When the control device 13A again interconnects the fuel source conduit 12A to the inlet means 18A of the closed safety valve 14A, the fuel now issuing from the pilot burner means 25A is ignited by the continuously burning standby pilot 15A and heats the members 38A and 34A of the condition responsive means 33A to cause the same to expand to the condition illustrated in FIG- URE 3A whereby the inlet means of the vacuum pump 29A is interconnected to the chamber 24A. The vacuum source 29A now evacuates the chamber 24A because the atmosphere tending to enter the same through the end 48 of the part 28A of the passage defining means 27A is restricted by the orifice means 44 to such an extent that the vacuum source 29A can evacuate the chamber 24A sufliciently for a pressure differential to be created across the diaphragm 23A that 'will move the diaphragm 23A upwardly in opposition to the force of the compression spring 40A in the manner illustrated in FIGURE 3 to open the valve seat 21A and permit fuel to flow from the inlet means 18A to the outlet means 20A and, thus, to the main burner means 11A and be ignited by the standby pilot means 15A and/or heater pilot means A in the manner previously described.

Thus, the safety valve means or actuator means 14A remains in the position illustrated in FIGURE 3 as long as a flame means exists at the heater pilot 25A.

Therefore, it can be seen that the control system 10A and the condition responsive means 33A illustrated in FIGURES 3, 3A, 4 and 4A prevent the vacuum source 29A from being interconnected to the actuator 14A when no flame exists at the pilot burner means 25A so that the atmosphere can be interconnected to the actuator :14A to cause the same to move to its operating position illustrated in FIGURE 4. Conversely, when the condition responsive means 33A is sensing a flame means at the heater pilot means 25A, the condition responsive means 33A interconnects the actuator 14A to the vacuum source 29A so that the vacuum source 29A can move the actuator means 14A to the operating position illustrated in FIG- URE 3.

Further, it can be seen that if the source of vacuum is lost, the condition responsive means breaks or if the pilot flame is not present, the vacuum in the actuator chamber is replaced by the atmosphere whereby the safety valve closes and prevents the main burner from operating.

Therefore, it can be seen that this invention not only provides an improved pneumatically operated control system or the like, but also this invention provides an improved condition responsive means for such a control system or the like.

While the form of the invention now preferred has been disclosed as required by the statutes, other forms may be used, all coming within the scope of the claims which follow.

What is claimed is:

1. In combination, a source of low pressure fluid, a source of high pressure fluid, a pneumatically operated actuator means having a chamber, means defining tubular passage means interconnecting said sources to said chamber of said actuator means whereby said low pressure source is adapted to cause movement of said actuator means to one operating position thereof and said high pressure source is adapted to cause movement of said actuator means to another operating position thereof, and condition responsive means, said condition responsive means including a member disposed inside of said tubular passage means to close the part of said passage means leading to one of said sources by engagement with the interior peripheral surface of said tubular passage means and cause the other source to cause movement of said actuator means to its respective operating position when said condition responsive means senses a certain condition and to open said part of said passage means leading to said one source by having a portion thereof spaced from engagement with the interior peripheral surface of said tubular passage means to cause said one source to cause movement of said actuator means to its respective operating position when said condition responsive means senses another certain condition.

2. A combination as set forth in claim 1 wherein said member expands to completely block said part of said tubular passage means to close the same.

3. A combination as set forth in claim 2 wherein said member expands when heated by a certain flame means.

4. A combination as set forth in claim 3 wherein said one source comprises the atmosphere and wherein said other source comprises a vacuum source.

5. A combination as set forth in claim 2 wherein said member unblocks said part of said tubular passage means to open the same when heated by a certain flame means.

6. A combination as set forth in claim 5 wherein said one source comprises a vacuum source and wherein said other source comprises the atmosphere.

7. A combination as set forth in claim 1 wherein said actuator means comprises fluid flow control valve means having an inlet and an outlet separated by a valve seat that is opened and closed by a valve member, said actuat' or means when in its said one operating position closing said valve member against said valve seat and when in its said other operating position opening said valve member away from said valve seat.

8. Acombination as set forth in claim 7 and including a source of fuel interconnected to said inlet of said valve means and a burner means interconnected to said outlet of said valve means.

9. A combination as set forth in claim 8 and including a pilot burner means, said condition responsive means sensing whether or not certain flame means exist at said pilot burner means.

10. A combination as set forth in claim 9 and including a control device intermediate said fuel source and said inlet of said valve means to direct fuel from said source to said valve means and said pilot burner means.

11. In a pneumatic system, a fluid source, a pneumatically operated actuator having a chamber, a tubular passage means fluidly interconnecting said source to said chamber of said actuator, and a condition responsive means forming part of said tubular passage means intermediate said source and said actuator, said condition responsive means including a member disposed in said tubular passage means and effecting the closing of said passage means by engagement with the interior peripheral surface of said tubular passage means when said condition responsive means senses a certain condition and etfecting the opening of said passage means by having a portion thereof spaced from engagement with the interior perpheral surface of said tubular passage means when said condition responsive means senses another certain condition.

12. In a pneumatic system as set forth in claim 11 said member being solid and blocking said passage means to close the same and unblocking said passage means to open the same.

13. In a pneumatic system as set forth in claim 12, said member expanding at a rate faster than the rate of expansion of said tubular passage means when heated.

14. In a pneumatic system as set forth in claim 12, said member contracting at a rate less than the rate of contraction of said tubular passage means when cooled.

15. In a pneumatic system as set forth in claim 11, said member comprising a solid cylindrical rod-like part coaxially disposed in said tubular passage means.

16. A condition responsive valve means comprising a tubular element having opposed ends, and a solid member disposed in said tubular element between said ends thereof, said member blocking said tubular element between its ends by engagement with the interior peripheral surface of said tubular element when said member senses a certain condition and unblocking said tubular element between its ends by having a portion thereof spaced from engagement with the interior peripheral surface of said tubular element when said member senses another certain condition.

17. A condition responsive valve means as set forth in claim 16 wherein said member expands at a rate faster than the rate of expansion of said tubular element when heated and contracts at a rate faster than the rate of contraction of said tubular element when cooled.

18. A condition responsive valve means as set forth in claim 16 wherein said member contracts at a rate less than the rate of contraction of said tubular element when cooled and expands at a rate less than the rate of expansion of said tubular element when heated.

19. A condition responsive valve means as set forth in claim 16 wherein said tubular element has means for retaining said member between said ends of said tubular element.

20. A condition responsive valve means as set forth in claim '19 wherein said retaining means comprise inwardly directed annular portions of said tubular element respectively disposed on opposite sides of said member.

References Cited UNITED STATES PATENTS 1,842,339 l/1932 Doen 431-42 X 1,875,388 9/1932 Magnet 431-58 2,418,671 4/ 1947 Schweller 62-214 2,746,534 5/1956 Brooks et al. 431-89 X 2,916,022 1'2/ 1959 Arant 122-504 3,042,769 7/ 1962 Campbell 200-83 3,172,601 3/1965 Caparone 236-21 3,272,487 9/1966 Cook et a1 236-87 X 3,319,888 5/1967 Creager 236-86 X FREDERICK KETTERER, Primary Examiner US. Cl. X.R. 236-68, 93

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