US2766818A

US2766818A - Oil burning furnace and control

Info

Publication number: US2766818A
Application number: US352410A
Authority: US
Inventors: Davis Ellis
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-05-01
Filing date: 1953-05-01
Publication date: 1956-10-16
Anticipated expiration: 1973-10-16

Description

Oct. 16, 1956 E. DAVIS 2,

OIL BURNING FURNACE AND CONTROL Filed May 1, 195:5 4 Shets-Sheet 1 flail.

45 ATTORNE Oct. 16, 1956 E. DAVIS on. BURNING FURNACE AND CONTROL 4 Sheets-Sheet 2 Filed May 1. l953 INVENTOR [AL/J fl/iws BY M Oct. 16, 1956 E. DAVIS 2,766,818

OII BURNING FURNACE AND CONTROL Filed'May l. 1953 4 Sheets-Sheet 3 INVENTOR I 4 24/5 0410s ATT Oct. 16, 1956 E. DAVIS OIL BURNING FURNACE AND CONTROL Filed May 1, 1953 4 Sheets-Sheet 4 INVENTOR ELL/S DA V/S MMgJW ATTORNEYS United States Fatent Gflice 2,766,818 Patented Oct. 16, 1956 OIL BURNING FURNACE AND CONTROL Ellis Davis, Bartow, Fla.

Application May 1, 1953, Serial No. 352,410

4 Claims. (Cl. 158-28) This invention relates to oil burning furnaces and the like and the automatic igniting and control thereof. This invention is particularly concerned with an improved construction and mode of operation for an oil burning space heating furnace which has a fully automatic oil supply and ignition control and which also is adapted to be controlled thermostatically to maintain temperature conditions within acceptable limits.

An object of this invention is to provide an oil burner of improved construction and operation which will maintain the temperatures within acceptable limits even though there are wide variations in the heating load.

In the drawings:

Figure 1 is a vertical section with certain parts shown in full lines of one embodiment of the invention;

Figure 2 is an enlarged vertical section of the igniter and fuel supply assembly;

Figure 3 is a plan view of the fuel control unit of Figure l with the cover removed and shown at the left of Figure 1;

Figure 4 is a vertical section on the line 44 of Figure 3;

Figure 5 is a horizontal section taken on line 55 of Figure 4;

Figure 6 is an end elevation taken from the right hand end of Figure 4; and

Figure 7 is a schematic wiring diagram of the control system.

Referring now to Figure 1 there is shown a space heater 10 of the pot-burner type wherein a layer of oil 12 is burned in the chamber 14 in the conventional manner with the expended gases being exhausted through chimney pipe 16. Positioned in the bottom of chamber 14 is an igniter coil assembly 18 shown more in detail in Figure 2.

Assembly 18 comprises an outer pipe or conduit 20 threaded into a projecting nipple 22 fixed in the bottom of chamber 14. The other end of pipe 20 is closed by a plug 24 which has sealed therein in an insulating material a central conductor 26 such that an electrical connection can be made to the interior of the pipe while maintaining the closure fluid tight. Connected to the inner end of the conductor 26 is a stranded wire member 28 which is positioned centrally within the pipe 20 by insulators 21 and projects up into the chamber 14. Fixed to the wire members 28 adjacent their upper projecting end is a spiral resistance coil 30 which performs the actual igniting of the oil. Coil 39 is electrically connected to the wire members 28 at point 32 and to the casing or tube 20 at point 34, the pipe 20 being normally grounded as shown in Figure 1. A source of voltage is then connected between ground and the wire members 28 through central conductor 26 of plug 24 and wire 36. Also connected into the pipe 20 at 38 is the oil supply pipe 48 which is connected through control unit 42 to the oil supply tank not shown.

As shown in Figure 4, the control assembly 42 comprises generally, a lower frame portion 44 containing therein oil inlet assembly 46 with

float controls

48 and 50 appropriate connecting linkages to permit the unified oper-- ation of the device.

In operation the oil from the supply tank not shown is fed into pipe 60 through the needle valve 62 into the lower chambers 45 formed by frame portion 44 until the float 48 is raised sufliciently to close ofi needle valve 62. Float 48 is pivoted at 64 and has a lever arm 66 engaging collar 68 on the shaft of needle valve 62, so as to force it downward against the action of spring 69 into the closed position as the oil level rises within chamber 45.

If for any reason float 48 does not shut oif the supply when the desired level is attained, emergency float 50 is provided to prevent flooding of the oil burner chamber. Float 50 is positioned within a separate chamber 70 and is pivotally mounted on one end of lever 72 which is in turn pivoted in the frame portion 96 at 74. Lever 72 has a catch portion 76 which in the normal position engages a lever 78 to hold it in its upper position. Lever 78 is biased toward its lower position by spring 80 connected between arm 82 thereof and frame 96. When float 50 is raised by an overflow of oil into chamber 70, lever 78 is released and brought into contact with the upper end of the stem of the needle valve 62 in hammer-like fashion to force the needle valve closed and shut off the inflow of oil.

Lever 78 may also be controlled by lever 84 which is pivoted in the frame portion 96 at 86 and has thereon

cam finger portions

88 and 98. Lever plate 78 carries at its right hand end in Figure 4, cars 92 which fit into slots in the frame portion 96 (see Figure 3). This permits movement of lever 78 in both vertical and horizontal planes. Cam finger of lever 84 is positioned to engage one of the ears 92 so that when lever 84 is pivoted counterclockwise in Figure 4, cam finger 9i) pivots lever 78 about the other ear 92 to move the end 79 of lever 78 laterally out of notch 76 to permit it to be driven downwardly by spring 80 to close the needle valve 62.

To reset the device the lever 84 is pivoted clockwise in Figure 4 to cause cam finger 88 to press on the end of lever 78 between cars 92 which forces end 79 to move upwardly over the rounded bottom of latch 76 into the notched position shown in Figure 4 thus releasing the needle valve 62 to open under the control of the float 48.

As may be seen in Figure 6, lever 84 carries therein a lever rod 98 which is also pivotally mounted in a bracket 99 on the frame at 100 and engages at each end thereof

solenoids

102 and 104. As may be seen in Figure 6,

energization of solenoid 102 will draw lever 84 downward to lift lever 78 into the position shown in Figure 4, and permit the inflow of oil through the needle valve ,62 under the control of float 48. Conversely energization of solenoid 104 will move the lever 84 upwardly counterclockwise in Figure 4, to release lever 78 to close off needle valve 62 and stop the inflow of oil into the chamber 45.

The igniter control assembly 56 mounted in the cover 54 comprises generally a lever 106 which is pivotally mounted at 108 and carries at one end a lever extension 110 which is positioned to engage two-way switch 112 to switch the apparatus from the igniter to the high fire position. The other end of lever 106 engages spring guide assembly 114 which acts as a guiding control to steady the operation of lever 186. Lever 186 is urged counterclockwise in Figure 4 by pivots 116 connected to diaphragm 118 mounted in the cover portion 54 by rod 119. Counterbalancing this movement is compressed spring 120 which is mounted between one end of lever 122 and a point on lever. 106 between pivot 108 and extension 110. The other end of lever 122 is pivotally mounted 3 in the cover portion 54 at 124. Intermediate it end lever 122 is engaged by screw bearing assembly 126. Assembly 126 comprises threaded hollow shaft 123 carrying at its upper end knob 132 and having mounted therein spring 1319. As knob132 is turned clockwise in Figure 5,;shaft' 1.28 advances downwardly in Figure 3 to pivot-the lever 122 downwardly to compress the spring 121 Diaphragm "118 is connected through tube 13 .(Figure 1) to pressure bulb 136 positioned outside the-chamher 14 and contacting the wall thereof. If desired, bulb 136 may be mounted on the side Wall of chamber 14 ad jacent the bottom thereof. Thus as the burner heats up, the pressure in pressure bulb 1336 increases expanding diaphragm ll which lowers pivots 116, permitting lever 1 to pivot clockwise about pivot 1138 allowing lever extension 1-10 to actuate two-way switch 112 to connect and disconnect the 'ignite'r coil and the high fire control, as will be described in detail herein.

Lever 138 is also mounted about'the pivot point 193 andis adapted to engage plunger 140 of oil outlet control assembly 52 in the lower frame portion 44. Plunger 146 is'in the form of a hollow tube and has an aperture 164 in the side wall thereof adjacent the bottom. Wall 168 of the. oil outlet assembly 52 has a corresponding aperture 166 positioned to coincide with aperture 164. and permit oil to flow therethrough into outlet pipe 170. Thus by varying the position of plunger 140 the outflow of oil may be accurately controlled.

Plunger 140 carries thereon a collar 142 which engages a spring 144 which at its lower end abuts the frame 4 1 and thus urges plunger 140 toward the upper position shown in Figure 4, stop 146 limiting the upward movement of lever 133 and thus plunger 140. Stop 172 is adjustedrto limit the downward movement of lever 133 so that plunger 14% may not be depressed beyond the low fire position. This leaves a small portion of

apertures

164 and 166 communicating so that oil may flow from chamber 44 through the tube 176 into the firing chamber 14 of the heater 1% whenever the level in chamber 45 is high enough. The position of lever 138 is controlled by the thermostatic control assembly 58 through a finger 150 which engages the upper end of a rod 148 which contacts lever 138.

Control assembly 58 comprises. a bimetallic strip 152 having mounted thereon a heating element 154 which is connected through the room thermostat contacts 157 to a source of power 163 (Figure 7) by the wires 156.

Referring now to Figure 7, the master switch 158 v transformer 161 or the wall thermostat and bimetallic strip energizing transformer 163 to the power supply in accordance with the movement of lever extension 110, as describedabove.

In operation when it is desired to operate the heater i 10 the master switch 158 is manually turned to the on position, which, as described above, makes contact 164) and makes and breaks the contact 162'to the oil-on soletained in the energized position as the lever; 78 is engaged by notch 76 of lever 72 and held in the inoperative position. Oil then continues to fill the chamber until'the needle valve 62 is closed under the action of floats4-8 or 5 0 all as described above. In-normal operation oil will flow from chamber 45 through partially

open apertures

164 and 166 and thence through pipe 40 into chamber 14 where it contacts the heated igniter coil and is in turn heated and ignited.

As may be seen more clearly in Figure 2 as the oil flows through pipe 41) and nipple 22 into the chamber.

14 it will be heated by the lower portion of the igniter coil 30 within nipple 22.' This heating will cause the oil within nipple 22 to move upwardly quite rapidly somewhat in fountain fashionso that it will flow or spray-over the upper portion of the igniter coil 31 which will increase the overall igniting action. This also tends to a cool the upper exposed portion of coil 30 so that it will not be burned out.

the lever 1436 is urged in the counterclockwise direction in a Figure 4 a ainst the action of spring 12% so that the lever extension 111 moves the switch 112 to the position shown in Figure 7. Thus, when the'master switch 158 is closed it connects the igniter coil 311 into the circuit. This heats and ignites the oil 12 flowing into the chamber, '14 as a 7 result of the energization of the oil-on solenoid 162.

Gradually as the temperature in the heating chambers] increases pressure is built up in the pressure bulb-diaphragm system causing diaphragm 118 to expandand lower the pivot point 116. This permits the lever 106 to rotate clockwise under the influence of spring 12! until the switch 112 is actuated from the position shown in Figure 7 to the reverse position to disconnect the igniter coil control transformer 161 and connect the high fire oil control transformer 163 across the power .circuit.- This transfers control to the wall thermostat which then regulates the flow of oil through the

apertures

164 and 166 under the control of the thermostat assembly 58;

The apparatus will then continue on low fire operation until heat is called for by the wall thermostat. When this occurs, contact 157 closes and heating element'154 heats the bimetallic strip 152 causing it to move upwardly from the position shown in Figure 4, to allow rod 148 to rise. This allows the lever 133 and the plunger to rise under the influence of spring 144 to bring more of aperture 164 into registry with aperture 166. More oil will then flow through the superimposed

openings

164 and 166 down through the pipe 17 iiinto pipe 49 and then into the chamber 14 providing more fuel and thus more heat until the room temperature reaches that called for by the wall thermostat. The furnace raft tends to create, a

reduced pressure in the furnace chamber 14-,so that there is an increased dificrential in the pressures in

chambers

14 and 45. This causes more oil to flow through pipe 49 p for the high fire operation, and the oil level in chamber 14 may exceed thefi-f inch level which is normally maintained by float 48. During low fire operation the main flame is above baffle 178 and .below'bafie 136, and during high fire operation the principal flame is above baffle 189. Whenthedesiredroom temperature is reached heater 154 is then deenergized by the opening of wall thermostat contact 157 and this causes the bimetallic strip 152 to 7 7 return to the position shown in Figure 4 and to shut down the oil flow to the low fire condition of operation.

,To turn theheater completely off, switch 15,8 isxthrown up tothe dotted line position show-nin Figure 7 thereby momentarily energizing oil-off solenoid 1194 and rotating rod 93 clockwise from the position shown'to stop the fiowof oil. 7 7

There is thusprovided a completely automatic control, for starting, igniting and regulating the. operation of; a space heater.

While there is givenabovefa specific example of this invention and its application in practical use, it should be understood that this is not intended to be exhaustive or to be limiting of the invention. On the contrary, these illustrations and the explanations herein are given in order to acquaint others skilled in the art with this invention and the principles thereof and a suitable manner of its application in practical use, so that others skilled in the art may be enabled to modify the invention and to adapt and apply it in numerous forms, each as may be best suited to the requirement of a particular use.

I claim:

1. A control device for a fuel burner of the character described comprising, supply means including a fuel line for supplying liquid fuel to said burner, igniting means for said fuel, and control means for controlling the supply of fuel to said burner in accordance with predetermined heating requirements, said control means including a first valve and a second valve connected in series in said fuel line for controlling the flow of oil to said burner, first electro-mechanical means connected to said second valve to vary the opening thereof, means forming a temperature-responsive electrical circuit to control said first electro-mechanical means in accordance with heating requirements, second electro-mechanical means connected to open and close said first valve in accordance with a signal, a master switch for energizing said means for igniting the fuel and also for energizing said second electromechanical means to open said first valve when said switch is closed and for energizing said second electro-mechanical means to close said first valve when said switch is opened, control means positioned in heat-exchange relation with the zone of said burner and including a switch for connecting said first electro-mechanical means to said temperature-responsive circuit and also for disconnecting said igniting means from said master switch when the zone of said burner has reached a predetermined temperature whereby a rise in the temperature of the burner above said predetermined temperature places control of the amount of oil supplied to the burner under the control of said second valve.

2. The device as described in claim 1 in which said second electro-mechanical means includes an oil-on solenoid and an oil-off solenoid, and a mechanical linkage coupling the movement of said solenoids to said first valve, said oil-0n solenoid being momentarily actuated to open said first valve when said master switch is turned on, said oil-off solenoid being momentarily actuated to close said first valve when said master switch is turned ofl.

3. The device as described in claim 1 in combination with a fuel overflow safety mechanism connected to said first valve in parallel with said second electro-mechanical means, said overflow mechanism including a chamber connected to said fuel line and a float actuated lever for limiting the level of fuel in said chamber by closing said first valve.

4. A fuel burner control device of the character described comprising, supply means including a fuel line for supplying liquid fuel to the burner, igniting means for igniting said fuel, and means for controlling the supply of fuel to said burner in accordance with predetermined heating requirements, said means for controlling including a valve connected in said line for controlling the flow of oil to said burner, first electro-mechanical means to vary the amount of fuel flowing in said line, a temperatureresponsive electrical circuit adapted to control said first electro-mechanical means in accordance with heating requirements, second electro-mechanical means connected to said valve in said line for opening or closing the valve in accordance with respective signals from a master switch, a master switch for energizing said igniting means and also for energizing said second electro-mechanical means to open said valve when said switch is turned on and for energizing this electro-mechanical means to close said valve when said switch is turned 01f, control means positioned in heat exchange relation to said burner and including a switch for connecting said first electro-mechanical means to said temperature responsive circuit and for disconnecting said means for igniting from said master switch when said burner has reached a predetermined temperature whereby a rise in the temperature of the burner above said predetermined temperature causes the amount of oil supplied to the burner to be controlled in accordance with signals from said temperature responsive circuit.

References Cited in the file of this patent UNITED STATES PATENTS 2,317,063 Johnson Apr. 20, 1943 2,416,766 Miller et al Mar. 4, 1947 2,503,260 Hall Apr. 11, 1950