US2016805A - Automatic heat regulating system - Google Patents

Description

@ct 9 1935- D. H. KINNAN AUTOMATIC HEAT REGULATING SYSTEM Filed' March 7, 1952 /NVEN770R YTENE vs W1} TNESS Patented Oct. 8, 1935 UNETED STATES PATENT OFFICE Lennox Furnace Company,

1110., Syracuse,

N. Y., a corporation of New York Application March 7, 1932, Serial No. 597,236

4 Claims.

This invention relates to new and useful improvements in automatic heat regulating systems adapted to be used in connection with boilers, furnaces, etc., and in which a thermostat control switch is electrically connected with a pair of control valves associated with the fuel supply conduit for governing the supply of fuel to the burner.

This invention relates more particularly to an automatic control for heat-producing systems adapted to burn natural or manufactured gas, as fuel, and wherein the main fuel supply conduit is provided with an automatic control valve and a by-pass extending around the valve having a second valve therein also automatically controlled for governing the flow of fuel therethrough.

The main object of this invention is to produce a simple, durable and efficient means for automatically controlling the opening and closing of the main fuel supply valve and the by-pass conduit valve independently of each other.

Another object is to provide for automatic closing of both gas valves in case electric current is discontinued or the pilot burner fails to function.

Other objects and advantages relating to the structure and the function and arrangement of the parts thereof, will more fully appear in the following description, taken in connection with the accompanying drawing in which:-

Figure l is a diagrammatic view illustrating a complete control system embodying the various features of this invention.

Figure 2 is a partial sectional view illustrating diagrammatically the manner in which the pilot safety control is associated with the pilot burner.

My novel temperature control system, as illustrated in the drawing, consists of a thermostat control switch member I, a main fuel supply conduit 2 connected with a burner 3 and having a control valve 4 connected therewith, and a bypass conduit 5 connected with the main conduit 2 at opposite sides of the valve 4 to extend around said valve and having a control valve 5 connected therein.

Each of the valves 4 and t have operably connected therewith a respective actuating motor I and 8 which have associated therewith suitable electric control circuits which are also connected with the thermostatic control switch I whereby the motors and valves may be automatically controlled under varying degrees of temperature independently of each other, as will hereinafter more fully appear.

The burner 3 may be of any desired type which, as illustrated in the drawing, is adapted to burn natural or manufactured gas and which is mounted in any well-known manner in a suitable fur-nace or boiler indicated at ill. The main fuel supplyconduit 2 may be connected with a suitable source -of fuel supply such as a gas main, not 5 shown, and extends through the wall of the furnace I B and is operably connected with the burner '3 in the usual manner.

Thecontrol valve -4connected in the ,main supply conduit 2 may be of any well-known type of 10 self-closing valves and which, as indicated, consists of a valve member "H normally maintained in closed position upon the seat I2 by a spring H3. The by-pass 5, as before stated, is connected with the main conduit 2 at opposite sides of the valve 4 and is of less cross-sectional area than the main conduit '2 so-that a smaller quantity of fuel is permitted to pass through the by-pass conduit than through the-main'conduit 2 when the valves 4 and 6 are in the open position.

The -bypass valve '6 is of the same springactuated type as the main conduit valve 4 and has the valve stem l5 thereof operably connected with the motor 8 in any suitable manner and which, in this instance, consists of an actuating disk Ni'having a drive pin I! connected therewith adapted to engage a lateral projecting lug it provided on the valve stem I5 for'moving the valve stem 15 and valve ll to the open position against the action-of the spring [3.

The disk It may be driven by the motor 8 through the medium of a train of gears, not shown, or may, as illustrated in the drawing, be connected directly with the armature shaft 20 of the motor "8. Similarly, the valve stem 22 of the valve 1 may be actuated by the motor "i by means of a disk 23 having a drive pin 2 adapted to engage a laterally extending lug 25 provided on the valve stem 22.

The disk 23 like the disk l6 for the valve 6 may be actuated by the motor 7 through the medium of a train of gears, or said disk may be connected directly with the armature shaft 26 of the motor I so thatwhen the motor '5 is actuated by a current passing therethrough, the valve member I i will be moved from the seat I2 against the action of the spring 13 to the open position, the motors l and 8 each being so constructed that when the respective valve members are moved to the open position, they will be maintained in said position against the action of the respective springs until such time as the circuit passing through the motor is broken, whereupon the respective valves will be returned to the closed position by the corresponding springs.

The thermostatic control switch I may be of any well-known type and which, in this instance, consists of a base 28, as indicated by dotted lines in the figure, and upon which is operably mounted a thermostatic element 29 connected at one end with an adjustable support 30 mounted on the base 28 and having secured to the other end thereof, a plurality of, in this instance three, swinging contact blades 3 I, 32 and 33.

The contact blades 3|, 32 and 33 are each composed of suitable material, such as brass, adapted to easily conduct electricity, and the blades 32 and 33 are formed from relatively thin metal so as to be easily flexed while the blade 3| is composed of a heavier piece of metal so as to be less flexible than the blades 32 and 33. Each of these blades is provided with a respective contact point 34, 35 and 35 adapted to co-act with corresponding contact screws 31, 38 and 39 which are adjustably mounted in respective posts 40, 4| and 42, which are mounted in insulated relation upon the base 28.

The electric circuit connecting the motors 1 and 8 with the thermostatic control switch consists, in this instance, of a transformer 45 having the primary winding 46 thereof connected by wires 41 with any suitable source of potential not shown, and the secondary winding 48 has the positive side thereof connected by a conductor 49 with a terminal 58 mounted on a switchboard 5|, indicated by dotted lines, and which may be mounted in any suitable location, preferably near the motor The motor 1 has one terminal thereof connected by a conductor 52 with the terminal 50 and the other terminal connected by a conductor 53 with a second terminal 54 also connected with the switchboard 5| and which is electrically connected by a conductor 55 to a terminal 56 provided on the base 28 of the thermostatic switch the terminal 56 being electrically connected by a conductor 51 with the contact screw 31.

The positive side of the secondary coil of the transformer 45 is also electrically connected with the motor 8 through the medium of a conductor 59 which has one end thereof connected with the terminal 50 on the switchboard 5| and the other end connected with a terminal 60 provided on a switchboard 5| indicated by dotted lines, and which is preferably mounted in a convenient locality near the motor 8.

The motor 8 has one terminal thereof connected by a wire 62 with the terminal 60, while the other terminal of the motor 8 is connected by a wire 63 with a terminal 64 provided on the switchboard BI and which is electrically connected by a conductor 65 with a terminal 65 secured to the base 28 of the thermostatic control switch and which, in turn, is electrically con nected by a conductor 66 with the contact screw 38.

The contact screw 39 on the thermostatic control switch in this instance, is connected with the negative side of the secondary coil 48 of the transformer 45 by means of a terminal bar 68 which is connected by a conductor 69 with a terminal 10 mounted on the base 28 of the switch The terminal 10 is connected by a conductor H with a terminal 12 mounted on the switchboard BI and which is electrically connected by a conductor plate 13 with a terminal 14 also mounted on the switchboard 6|. This terminal 14 is connected by a conductor 75 with a terminal 16 mounted on the switchboard 5| and which, in turn, is connected by a conductor 11 with the negative side of the secondary coil of the transformer 45.

The armature shaft 23 for the motor 8 is provided with a cam 19 which, during the initial movement of the motor 8, is adapted to close a 5 switch 8|) which has one terminal thereof connected by a switch bar 8| with the terminal 54 on the switchboard El and the other terminal electrically connected by a conductor 82 with a terminal 83 mounted on the base 28 of the control 10 switch and which is in electrical connection with the supporting member 33 for the thermostatic element 29.

Each of the valves 4 and 6 may, when desired, be manually opened and be maintained in the 15 open position, if for any reason the current for the motors and 8 is discontinued, and which mechanism for the valves 4 for instance, consists of an extension 85 having one end secured to the valve stem 22 and the other end thereof provided 20 with an elongated slot 86 through which is slidably mounted a switch-actuating member 3'! slidably mounted on the switchboard 5|.

The outer end of the switch-actuating member 81 is provided with a cam face 88 adapted to en 25 gage the outer end of the slot 85 for moving the extension 85 and valve stem 22 outwardly against the action of the spring l3 as the switch-actuating m mber 81 is moved inwardly. As the member 81 approaches its innermost position, the end 30 of the extension 85 engages a recess 89 provided in the member 81 adjacent the cam face 88 so that the valve M will be thereby maintained in the open position by the actuating member 8?, while said actuating member will be maintained 35 against outward movement by the extension 85 engaging said recess 89.

The opposite or inner end of the switch-actuating member 81 is associated with a movable con tact bar 90 of a switch member 9!, said bar hav- 40 ing one end thereof secured to the terminal 54 mounted on the switchboard 5|, while the other end of the bar is adapted to be moved into electrical connection with a switch contact member 92 of the switch 9| and which is secured to a 5 terminal 93 electrically connected by a conductor bar 94 with the terminal 16.

The mechanism by which the by-pass valve 6 may be manually controlled, as before stated, is similar to the mechanism for the valve 4 and 5 consists of an extension 96 having one end connected with the valve stem 5 and the other end having a slotted connection with the switch-actuating member 91 slidably mounted on the switchboard Bl. This switch-actuating member 91 is 55 also provided with a cam face 88 and a recess 99 similar to the cam 88 and recess 89 of the switch-actuating member 81.

The inner end of the switch-actuating member 91 terminates in juxtaposed relation with a switch 0 member I30 which has a movable contact bar |0| secured to the terminal 64 and adapted to be moved by the switch-actuating member 97 into contact with a fixed contact bar I32 which is electrically connected with the terminal 72. 55

The burner 3 is provided with a pilot burner which is provided with a supply conduit I05 connected with the main conduit 2 at the inlet side of the valve 4, and in order that no fuel as gas will be fed to the burner 3 if for any reason 70 the pilot light should be extinguished while the heating system is being automatically controlled, I have provided a pilot safety control indicated at ||0 which is connected in series with the transformer 45 and motors and 8. 75

This pilot safety control III! may be of any suitable construction and as illustrated more clearly in Figure 2, consists of a thermostatic element III positioned in close relation to a series of fine apertures I I2 provided in the pilot burner tube through which the fuel escapes to form a blaze for heating the element II I. This element III is connected by a rod I I3 to a normally open switch II so that when the'element is heated, the switch is closed by the action of the element for closing the energizing circuit for motors i and 6. It is thus seen that in case the pilot light should be extinguished, the circuit passing through the safety pilot switch I I l will be broken permitting the valves I I for each of the fuel control valves 4 and E to be returned to their closed position by the respective springs I3 in case said valves are in the open position, thereby shutting off the supply of fuel to the burner 3 and prevent the possibility of an explosion of gases which otherwise might accumulate in the furnace or heater.

In operation, the blades of the thermostatic control switch I may be adjusted in any wellknown manner, not herein necessary to illustrate or describe by the manipulation of the contact screws 3?, 38 and 39 and by adjusting the supporting member 39 for the thermostatic element 29 so that the swinging blade 33 will be in electrical contact with the contact screw 38 when the temperature in the room or building is at a predetermined desired degree according to the setting of the thermostatic control switch.

The bar 32 and contact screw 39 are so related that they will be in electrical connection while the temperature is at the desired degree and will break the circuit therethrough when the temperature rises to a certain amount, say two degrees above the desired normal temperature, while the contact bar 3i and contact screw 3? will be normally maintained out of electrical connection and will only come into electrical connection when the temperature drops a certain amount, say two degrees below the normal or desired temperature.

Assuming now, that the thermostat control switch has been set to maintain a normal temperature of say seventy degrees, in which case the contact bars 32 and 33 will be in electrical connection with the respective contact screws 38 and 39 when the room temperature is at seventy degrees and the contact bar 3I will be out of electrical connection with its contact screw 31, under which condition the main supply conduit valve 9 will be maintained in its closed position by the spring I3 due to the circuit passing from the transformer 45 through the conductors t9 and 52, the motor I, and conductors 53, 55 and 5? being broken at the end of the screw 31. The valve 6, however, in the by-pass 5 will be maintained in the open position due to the current passing from the transformer 45 through the conductors 39, 59 and 62, thence through the motor 8 and conductors 63, 65 and 66 to the contact screw 38 and thence through the swinging blade 33 of the control switch I to the blade 32 and thence out through the contact screw 39 and terminal bars 88 to the conductors I59 and II to the terminal I2 and thence through the conductor bar I3 and conductors I5 and I? to the transformer 65.

This maintaining of the valve 4 in the closed position and the valve 6 in the open position will permit a reduced quantity of fuel to be supplied to the burner 3 which will provide a reduced flame for producing a corresponding amount of heat. If the heat thus produced is insufficient to main tain the room or rooms at the desired temperature, say seventy degrees, the thermostatic element 29 will thus be effected to cause the swinging blades SI, 32 and 33 to be moved towards the left or towards the contact screws, which ac- 5 tion will be permitted due to the flexibility of the contact blades 32 and 33 until the contact blade BI comes in contact with the contact screw 31 closing the circuit which passes from the transformer 45 through the conductors 69 and 52 to 10 the motor l and thence through the conductors 53, 55 and 51 to the contact screw 3? and thence out through the contact blades 3| and 32 through the contact screw 39 and terminal bar 68 and thence through the conductors 69 and TI to the terminal '52 and thence back to the transformer 45 through the conductors I5 ,and TI.

As this circuit through the contact screw 3! is completed, the motor I will be actuated to bring the pin 24 into engagement with the lug 25 for moving the valve stem 22 outwardly and bringing the valve I I into the open position, thereby permitting a maximum amount of fuel to be supplied to the burner 3, which will produce a correspondingly increased amount of heat for 25 again bringing the temperature in the room or rooms up to the desired or predetermined degree. As the temperature in the room approaches the desired degree, the thermostatic element 29 will again be actuated to return the blades to the 30 normal position which will break the contact between the contact blade 3I and the screw 31, thereby releasing the motor I and permitting the valve member II to be returned to its seat I2 by the spring I3, which will again close the direct passage through the main conduit 2 and permit only a limited supply of fuel to be supplied to the burner 3 through the by-pass 5.

This operation may be continued indefinitely as long as fuel is supplied to the burner 3 and cur- 40 rent is present in the transformer 45. If, however, the temperature in the room should rise above the desired degree, it is obvious that the thermostatic element 29 will be actuated thereby to move the blades 3|, 32 and 33 towards the right or in a direction away from the contact screws 3?, 38 and 39 until such time as the terminal blade 32 is brought out of contact with the terminal screw 39. Prior to breaking of the circuit at screw 39 the connection between the terminal screw 38 and contact blade 33 will have been broken discontinuing the circuit therethrough for the motor 8. After the circuit has been broken at screw 33 and before the blade 32 is separated from the contact screw 39 current for the motor 3 will be supplied from the transformer 45 by the current passing from the motor 8 through conductor 63 and switch 86 which will have been closed during the initial movement of the motor 8 by the action of the cam I9; the current then passes from the switch 83 through the conductor 82, terminal 83 and supporting member 39 to the thermostatic element 29, blade 32 and contact screw 39. As the electrical connection between the blade 32 and screw 39 is broken by the con- 65 tinued outer movement of said blades, the motor 8 will then be released in the manner hereinbefore stated, whereupon the motor 8 will permit the spring I3 to return the valve member II in the by-pass valve 6 to its seat I2 thus closing the valve (5 shutting off all fuel supplied to the burner 3.

As the temperature in the room is thus permitted to lower, the thermostatic element 29 will again move the blades toward the contact screws 31, 38 and 39 until the temperature approaches the predetermined degree whereupon contact blade 33 will again come into electrical connection with the contact screws 38 thereby establishing a circuit therethrough for supplying the motor 8 in the manner previously described, which will cause said motor to actuate the disk l6 and pin I! for bringing said pin into engagement with the lug l8 on the valve stem [5 and move the valve member I I of the valve 6 against the action of the spring ii to the open position for again supplying a limited quantity of fuel to the burner 3.

If it should be desired to manually open either the valve 4 or valve 6 or both of these valves, due to the failure of current being supplied through the transformer 45 to the motors I and 8 or for any other reason, this may be accomplished by merely moving one or both of the switch-actuating members 8'! and 91 inwardly which action will draw the respective valve member H to a partial open position, and at the same time, close one or both of the respective switch members SI and H18 so that these valves may be safely left in the partially opened condition until such time as the current is again supplied to the transformer 65. As the current is again returned to the circuit, the motors i and 8 will be operated thereby to bring the valves into the full open position regardless of the position of the swinging blades Si, 32 and 33 of the thermostatic control switch 1 due to the current from the motor I, for instance, passing through the conductor 53 and switch 9i back to the transformer 45 through the conductor plate 94 and conductor 11.

Likewise, the current supplied from the transformer 55 to the motor 3 will be returned to the transformer 45 without having to pass through the thermostatic switch I by passing from the terminal G l through the switch I00, conductor bar is and conductors l5 and 11 to the transformer. As the motors l and 8 are thus actuated to bring the respective valves into the full open position, the respective switchactuating members 8! and M will thereby be released by the outward movement of the corresponding extensions and 93 and permitted to be returned to the normal out position by the action of the movable contact bars 98 and ll of the respective switches 9i and Elli], after which the fuel will be automatically controlled in the manner hereinbefore explained by the action of the thermostatic control switch I governing the current supplied to the motors i and 8.

It is now obvious that I have produced an automatic heat regulating system in which the control valves in the main supply conduit and in a by-pass conduit will be automatically opened or closed by the action of a temperature controlled switch independently of each other, and although I have shown and particularly described the preferred embodiment of my invention, I do not wish to be limited to the exact construction shown or to any specific construction of motors, valves or other operating mechanism, or to the exact hookthermostat control switch in said circuit adapted to control the operation of each motor whereby the valves may be operated independently of each other, and manually controlled means associated with each valve for maintaining said valve in a partial open position when the energizing circuit is discontinued.

2. In a heat-regulating system, the combination with a fuel burner, of a pair of fuel conduits of different capacities adapted to supply fuel to the burner, a valve in each of said conduits, an electric motor co-operatively associated with said valve, an energizing circuit for said motors, a thermostat control switch in said circuit adapted to control the operation of each motor whereby the valves may be operated independently of each other, and manually controlled means associated with each valve for'maintaining said valve in a partial open position when the energizing circuit is discontinued and automatically releasing the valve when said circuit is again established.

3. In a heat-regulating system, the combination with a fuel burner and a pilot burner, of a pair of fuel conduits adapted to supply fuel to said fuel burner, a valve in each of said conduits, an electric motor co-operatively associated with each valve, an energizing circuit for said motors, a thermostatic control switch in said circuit adapted to control the operation of each motor, and a safety pilot control connected in said circuit in series with said motors, and switch for automatically causing the closing of said valves when the pilot flame is extinguished.

4. A heat-regulating system comprising in combination, two thermostatically controlled switches adapted to open and close successively as the temperature varies, a burner, a pair of fuel conduits operatively connected with the burner, a valve in each of said conduits, means for opening said valves independently of each other comprising an electrically actuated operating means actuated by a respective switch whereby a larger or lesser predetermined steady flow of fuel will be established and maintained as determined by the temperature affecting said switches, and additional means for maintaining one of said valves open after the circuit through both of the switches has been broken comprising an electrical circuit having a third thermostatically controlled switch and a mechanically operated switch therein, said latter switch being closed by the operating means for said valve during the initial movement thereof.

DONALD H. KINNAN.

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