US2296322A

US2296322A - Thermoelectric safety shutoff device

Info

Publication number: US2296322A
Application number: US303601A
Authority: US
Inventors: Henry F Alfery
Original assignee: Milwaukee Gas Specialty Co
Current assignee: Milwaukee Gas Specialty Co
Priority date: 1939-11-09
Filing date: 1939-11-09
Publication date: 1942-09-22
Anticipated expiration: 1959-09-22

Description

Sep- 22, 1942 H. F. ALFERY 2,296,322

THERMOELECTRIC SAFETY SHUTOFF DEVICE Filed Nov. 9, 1959 2 Sheets-Sheet l Sept 22 1942- H. F. ALFERY 2,296,322

THERMOELECTRIC SAFETY SHUTOFF DEVICE 2 Sheets-Sheet 2 Filed Nov. 9, 1939 Patented Sept. 22, 1942 Henry F. Alfery, Milwaukee, Wis., assigner to Milwaukee Gas Speciality Company, Milwaukee, Wis., a corporation of Wisconsin .pplication November Si, 1939, Serial No. 303,601

3 Clas.

This invention relates to safety devices for heating and other apparatus and has particular relation to an improved thermoelectric valve for automatically shutting off the fuel supply for a burner upon extinguishment of a pilot light or other flame.

The present invention is a `continuation in part of my copending application Serial No. 186,967, led January 26, 1938, and now Patent No. 2,276,909, granted Mar. 17, 1942.

The illustrated embodiment of the invention comprises generally a valve adapted to be positioned, for instance, in the fuel supply line leading to the burner, an electromagnet, an armature for the electromagnet which, when attracted, is

adapted to maintain or to permit the valve to be maintained in open or operating position, and when retracted, compels closing of the valve to shut off the supply of fuel to the burner, and a thermocouple adapted to be placed in position to be heated by a pilot light or other flame and connected in circuit with the electromagnet.

One of the main objects of the present invention is to provide an improved quick detachable connection between the lead conductors for the thermocouple and thethermoelectric safety device. l

It is also an object of the invention to provide means for shutting o or interrupting the ow of fuel to the main burner during the operation of resetting the armature to attracted position and the thermoelectrie valve to open position-or other thermoelectric control means to operating position-and, in conjunction therewith, means for by-passing fuel, for instance, for the pilot burner while the ow of fuel for the main burner is thus interrupted during the resetting operation and wherein, at the same time, the thermoelectric valve operates to shut o not only the supply of fuel to the main burner, but also the sulpply of fuel for the pilot burner when the pilot burner or other name, to the heat of which the thermocouple is subjected, is extinguished.

Another object of the invention is to provide an improved electromagnet assembly and mounting therefor, and more specifically, an improved electromagnet assembly lhaving guide means for the armature adapted to constitute a part of such assembly and having also quick detachable connector means constituting a part of the electromagnet assembly and adapted, when the electromagnet assembly is mounted within the enclosure therefor, to project from the electromagnet enclosure for quick detachable connection with the quick detachable connector means on the thermocouple leads.

Further objects and advantages of the invention will be apparent from the following detailed description, takenA in connection withthe accompanying drawings, in lwhich:

Figure 1 is a vertical section through a thermoelectric valve embodying the present invention; Figure 2 is a sectional view taken on the line 2 2 of Figure 1;

Figure 3 is a fragmentary vertical section partially in elevation and showing the quick detachable connector means on the thennocouple leads connected with the quick detachable connector means on the thermoelectric valve; and

Figure i is a fragmentary elevational view showing the quick detachable connector means on the thermocouple leads.

The device is shown as a thermoelectric safety shutoff valve for shutting off the supplyvof fuel tothe burner, which, for instance, may be the burner for a room, oven, or other space heater. or the burner for a water heater, conversion heater, or any other burner.

The device selected for illustration comprises a valve body i@ having a fuel inlet il and a fuel outlet l2 which are tapped internally to receive the inlet and outlet pipe sectionsifi and i6, respectively. The inlet pipe section receives the fuel from a suitable source of fuel supply, and the outlet pipe section leads to the burner.

The valve body has an internal wall or partition l5 which has a valve opening i6 through which communication is adapted to be eifected between the inlet chamber i8, which is in communication with the inlet li, and the outlet chamber i9, which is in communication with the outlet i2. Communication between the inlet chamber i9 and the outlet chamber I9 through the opening it is controlled by al valvevmember 25 shown as adapted to seat upon the Valve seat 25', preferably in a direction with the flow of gas or other fuel, the arrow 26 indicating the direction of ow of the fuel. The valve member 25 is held to the inner end of the valve stem 28, for instance, by a U-shaped fastener, snap ring, or

other fastener means indicated at 29. The particular valve disc shown in the drawings has a valve disc gasket or yielding seating material 3U secured thereto by a valve disc screw 32, an intervening Washer being shown at 36. These features may vary within the scope of the present invention.

The hood and cup assembly which encloses the electromagnet and armature for the thermoelecl pressed fit or is otherwise suitably secured in the inner end oi the -hood 35, and encloses and sealsv the interior of the hood'from the deleterious ac.- tion of the gas or other fuel which passes through the valve body. The hood 55 is clamped to the valve body i8 by a union nut 42, with the hood and cup assembly closing the opening 44'in the valve body. A union gasket may be provided at 45. I

The electromagnet, which is sealed within the hood and cup assembly comprises a magnet frame 50 shown in the drawings as of U-shaped form, although this may vary widely. The magnet frame 55 is secured at 52, and is supported by a metallic plate 54. A metallicv terminal stud 55 having an enlarged outer end at 55 and a reduced stem l extending inwardly therefrom fits in a correspondingly formed metallic bushing 58. A metallic washer 59 underlies the adjacent portion of t-he plate 55 and is secured with the plate 54 to the bushing 58 and lstud 55, for instance, by extending the reduced inner end of the stud 55 through the washer 59 and heading the inner end of the stud over as indicated at 50, or otherwise as desired. The stud, which is thereby secured to the plate 54 with the bushing 55 so that these parts constitute a unitary assembly, is insulated from the bushing 55 by insulation indicated at 52. The washer 59 isv insulated from the platei 54 by insulation indicated, at 58.

The bushing55, with the stud 55 secured therein as set iorth, extends outwardly through an opening 55 in the outer end of the hood 35. The bushing 58 is externally threaded, and a nut '55 threaded thereon clamps the bushing and stud assembly in place in the opening 55. Screws` 60 or other suitable means may be employed for additionally securing the plate 54 to the outer end of the 'hood 35. Packing may, if desired, be interposed between the plate 54 and the outer e'nd wall of the hood 36 as indicated at 55. If desired, the bushing 58 may be grounded tothe hood 35.

` One terminal of the magnet coil 10, which is shown as surrounding one of the legs of the magnet frame 50, is connected at 12 to the terminal stud 55. The other terminal of the coil 'I0 is connected at 'i3 tothe plate 54, and through the plate 54 to the terminal bushing 58.

One of the terminals of the-coil 'I0 is adapted to be connected in circuit with one of the thermocouple leads through the stud 55, and where the bushing 58 is insulated from the hood 35, the other terminal of the coil I5 is adapted to be connected in circuit with the other thermocouple lead through the bushing 55. Where the bushing 58 is grounded to the hood, this side of the thermoelectric circuit is completed by grounding one side of the thermocouple and one of the terminals of the coil l5, for instance, to the hood 36. The enlarged o uter end of the stud 55 has a conical recess l5. l

Insulating strips are provided at 80 and 82, and

' an insulating strip 53 is provided Vbetween one side of the coil 'i0 and the adjacent leg of the magnet frame 50. The

insulating strips

80 and 52 have openings through which the legs of the magnet frame extend, and underlying the insulating strip 52 is an amature guide 84 which may be formed of metal or other suitable mate- 55, and screws 55, one at each of the opposite sides of the electromagnet, have their heads engaging the flange and their shanks extending through registering openings in the insulating strips and 82 and threaded at their outer ends in the depressed -portion oi the plate 54. The screws hold the insulating strip 82 and annature guide 84 in place so that these parts, with the magnet frame 55, coil l0,

insulatingstrips

80 and 82, plate 54, Aand the stud and bushing terminal connector, constitute a unitary assembly which, upon being positioned within the cup 36 is adapted to be secured in place therein by the nut 55 and screws 68, only one of which lat- I ter screws is shown.

'Ihe armature 90 has attached thereto by upwardly extending bent-over portions 8| a. cradle 92 which, in turn, is connected to the upper or outer end of the valve stem 28, preferably for limited universal movement, for instance by means of U-shaped retainers 93 engaging grooves in the upper end of the valve stem 28. The armature is guided for reciprocatory movement by the armature guides 84, and the attachment of the valve member 25 to the lower end of the stem 28 preferably allows limited universal movement with respect to the stem. This limited universal movement oi' the armature and valve on the stem 28 permits self-accommodation of the armature to the pole ends of the magnet frame and self-accommodation of the valve member 25 to its seat 25.

For the purpose of resetting the valve 25 to open position and the armature 90 to attracted position against the pole ends of the magnet frame 50 after the coil I0 is deenergized or after it becomes insuiliciently energized to hold the armature in attracted position. a resetting stem |00.is mounted for sliding movement in the valve body I0 in axial alignment with the valve 25. Secured upon the lower end of the. stem |00 is a reset button I0|, and ilxed upon the upper end the pilot burner (not shown).

the passageway I I2 may be closed at I I4. This of the stem is a valve member |02. The valve member 02 has a depending annular flange or rib |03 which engages the packing'l04 and presses the same tightly around the stem |00 to prevent leakage of gas or other fuel out along the stem. The packing |04 is carried by a gland member |05 mounted in the opening |05, and this opening is sealed against the leakage of gas by suitable packing indicated at |08. A washer is provided at |09, and surrounding the stem |00 and interposed between the washer |09 and the reset button |0I is a coiled spring ||0 which normally maintains the flow interrupter valve |02 in open position, as shown, and the reset button |0| in outwardly projected position.

Opening laterally from the valve opening I5 intermediate the ends thereof is a passageway ||2 which is connected to a tube or fuel supply pipe 3 for delivering gaseous or other fuel to The outer end of position closing oif communication from the inlet rial. The outer end of the guide 54 has a ilange 75 chamber I8 to the outlet chamber I9 through the valve opening I6 during the resetting operation. At the same time, the passageway 2 is so disposed that the valve member 25 operates to shut oil' not vonly the supply of gaseous fuel= to the main burner, but also the supply of gaseous fuel to the pilot burner when the valve member 25 is closed against itsseat 25'.

The thermocouple is shown by way of illustration and not by way of limitation as of the general character disclosed and claimed in Oscar J. Leins Patent No. 2,126,564, granted August 9, 1938. The thermocouple comprises an outer tubular metallic thermocouple member |20 and an inner metallic thermocouple member I2| joined at one end to the end of the outer thermocouple member to form the thermal junction |22 which is placed, for instance, in position to be heated by the pilot light or any other desired name. An inner lead conductor |23 is joined to the inner thermocouple member to form an internal thermal junction |24, and an outer tubular lead conductor |25 is connected to the outer thermocouple member |20, for instance through a sleeve |26 to form a third thermal junction |28. rI Che outer lead conductor |25 encloses the inner lead conductor |23, and with the outer thermccoupe member and the sleeve |26 constitutes an enclosure about the inner thermocouple member and the inner lead conductor and the inner thermocouple junction |20. The inner lead conductor |23 is insulated from the outer lead conductor, for instance, by a Wrapping of insulation on the inner lead conductor as indicated at |26.

The free end of the inner thermocouple lead |23 extends from the adjacent end of the outer lead |25 and has xed thereon and in good conducting contact therewith a wedge member or metallic connector cone |30. The outer lead conductor |25 may have fixed thereon a metallic connector sleeve |32 in good conducting contact therewith. The sleeve |32 is insulated from the cone |30 by insulation indicated at |34. A couple lead connector nut is provided at |36, this nut having an internal shoulder which cooperates with a shoulder on the sleeve |32.

By applying the connector means on the thermocople leads to the connector terminal means on the thermoelectric safety valve with the cone |30 positioned in the recess l5 and threading the nut |36 upon the bushing 58, the cone |30 is wedged into the recess l5, and consequently makes good positive Contact with the stud 55, thereby connecting the lead |23 with one terminal of the coil l0. At the same time, the threaded engagement between the nut |35 and the bushing 58 together with the clamping of the nut |35 against the connector sleeve |32 forms a goed positive connection between the adjacent end of the lead |25 and the bushing 58, thereby connecting the lead |25 to the other terminal of the coil 70. The thermocouple leads are quickly disconnected from the device by unscrewing the nut |36 from the bushing 50, and the connection is made quickly in the manner set forth.

Theoperation of the device is as follows:

When it is desired to ignite the main burner or other burner supplied with iuel from the outlet |2, the reset button is pushed manually in an inward or upward direction. This moves the valve member 25 to open position away from the seat and the armature 90 into attracted position engaging the pole ends of the magnet frame 50. In this raised position of the reset stem |00, the ilow interrupter valve |02 enters the valve opening |6 and shuts off communication between the inlet chamber |8 and the outlet chamber l through the opening I5 and thereby the liow of fuel to the main burner to prevent the escape of gaseous fuel from the main burner during the resetting operation.

The valve member 25 is open, however, at this time, and the passageway H2, by-passing the coA A|22 subject to the heat of the pilot Iiame and,

as a result, the pilot name energizes the thermocouple, creating a thermoelectric current which energizes the coil l0 and causes the .armature 00 to be held in attracted position and the valve 25 to be held in open position against the tension of the spring' |20. The reset button |0| may then be released, and the spring H0 moves the stem |00 downwardly to the position shown in Figure 1, and with it the valve |02 to open position.

The gaseous fuel then flows through the valve opening |6 and out through the fuel supply line I4 to the feed pipe to which air is admitted, and the gaseous mixture enters the main burner where it is ignited by the pilot burner as it issues from the ports of the m'ain burner. In case the main burner is accidentally extinguished, the pilot burner will reignite thesame, and thereby assures that the main burner is lighted as long as fuel is supplied thereto.

If the pilot burner is extinguished, the thermoelectric current through the coil 10 diminishes to such an extent that the armature is released, whereupon the spring |40 forces the valve member 25 into engagement with the seat 25', thereby shutting oi the ow of fuel to the mail! burner and to the pilot burner.

The bottom wall of the cup 40 is shown as depressed at |4I and provided with an opening |42 in which the stem 28 has reciprocatory movement. The opening-|42 is sealed against the leakage of gas or other fuel from the body 0 into the electromagnet enclosure by suitable packing indicated at |43. A washer is provided at |45, and the spring |40 surrounds the valve stem 28 and is interposed between the washer |25 and the valve member 25. The spring |40, which is shown as of generally conical form, in addition to moving the valve 25 to closed position and the armature 90 to retracted position upon extinguishment of the iiame, compresses the packing |03 tightly about the stem 20 to prevent leakage of fuel into the hood and cup assembly.

The pilot fuel supply passageway H3 extends out at |70 from opposite sides of the valve body as indicated in Figure 2, and the diametrically opposite outlets of this passageway are provided with screw plugs |2. By removing either plug |12, the pilot supply tube may be connected to either side of the valve body as desired.

I do not intend to be limited to the precise details vshown or described.

I claim:

1. In a device of the class described, a valve body having an inlet and an outlet and means dening a passage between said inlet and said outlet, a pilot outlet leading from said passage, shutoff valve means operable to closed position anterior of said pilot outlet to shut oi the flow through said iirst outlet and said pilot outlet, reset means cooperable with said shutoff valve means for actuating said shutoff valve means to open position, and a second valve actuated to closed position posterior of said pilot outlet by the resetting operation of said reset means to shut oi the flow through said first outlet without shutting off the flow through the pilot outlet dur-i ing the resetting operation, said second valve inlet and outlet for permitting continued resetting movement after the iiow through said ilrst outlet is shut oir by said second valve.

2. In a. device oi' the class described, a'valve.

body havingl an inlet and an outlet, a partition wall disposed between said inlet and outlet and having a valve seat on one side of said wall and a valve passage opening through said wall, a shutoff valve member operableto closed position engaging said valve seat to 'shut oi! fluid now through said outlet, a reset plunger adapted to be projected inwardly to reset said shutot! valve to open position, and a. valve member ilxed on said reset plunger and cooperable with the passage in said partition wall to shut oil' the ilow through said outlet during the resetting operation and by movement in said passage permitting re setting movement alter the flow through said outlet is shut om by said second valve member modena and without relative movement between said seeond valve member and said reset plunger.

3. In s device ci' the class described, a valve body having an inlet and an outlet and means defining a e between said inlet and nid outlet, a shutoi! valve member operable to closed position to shut oil.r the now through said outlet, reset means cooperable with said shutoff valve member for actuating saidshutoff valve member to open position, and a seeond valve member lctuated to closed position by the resetting operation of said reset 'means to shut oi! the flow through said outlet during the resetting opera-` tion, said second valve member having movable dt -in the e between the inlet and outlet for permitting continued resetting -Y movement aiter the new through said outlet is shut oi! by said vsecond valve member.

` HENRY F. ALF'ERY.