US1836268A - Lighter for burners - Google Patents

Description

Dec. 15, 1931. D, F. MCFARLAND ET AL LIGHTER FOR BUR'NERS Filed March 14, 1927 3 Sheets-Sheet ff 47 /8 d'1* W www W RA n eAD r .UW a NME Es /ra Dec. l5, 1931. D. F. MCFARLAND ET AL 15836268 LIGHTER -FOR BURNERS Filed March 14, 1927 3 Sheets-Sheet 2 2 OFF 2N /44 /43 49 /45 W 4o y 39 8 35 a6 IzefzZ-ons DALE EMCFARLAND y REX E. DAV/S Dec. 15, 1931. D. F. MGFARLAND ET Al.

LIGHTER FOR BURNERS 3 Sheets-Shed 5 Filed March 14. 1927 Z'zenjors DALE l-TMCFARLAND REX E. DAVIS Patented' Dec. 15, 1931 .dan frf DALE F. inrcFAJaLAND.,f or niNNEAroLIs. AND anx E. DAvIs, or ANoKA, MINNESOTA, AssIGNoBs rro ANDREW E. cAmsEN, or mNNnAnoLIs, MINNESOTA LIGHTER FOR BURNERS tltus, and the primary object is to provide means of a novel, efiicient and practical nature for lighting such burners when they are either manually or automatically supplied with fuel at'regular or irregular intervals 10.A further and more specific object is to provide means, of a primary nature, for lighting a series of burners in an apparatus, such as a boiler, and in combination therewith to provide means of a secondary nature, for

first lighting the primar means. A further object is to provide a running pilot, for lighting the main burners, a permanent pilot, for lighting the running pilot, and means associated with the main fuel supply valve of the burners, for automatically lighting the running pilot immediately or shortly before supplying the fuel to the main burners, and, as soon as the main burners thus become lighted by the running pilot ,to extinguish the running pilot, until the main burners are to again be lighted. A further object is to provide thermally infiuenced means, in conjunction with the lighter, for electrically disconnecting a temperature-control thermostat, whereby such thermostat Iwill be rendered ineffective to start the flow of fuel to the main burners in the event that the pilot .burner should become accidentally extinguished. Still further and more specific objects will be disclosed in thel course of the following specification, reference being had to the accompanying drawings, wherein:

Fig. 1 is a planiview, partly in section,

illustrating the application of my invention to a boiler having, a plurality of gas burners.

Fig. 2 is a sectional elevation as seen on the line 2-2 in Fig. 1.

Fig. 3 is a sectional elevation on the line 3--3 in Fig. 2.

Fig. 4 is a-sectional elevation on'the line 4-4 in Fig. 2.

Fig. 5 is a sectional elevation as on the,

the nia-in burners B. The

line 5 5 in Fig. 1, but with various portions broken away for purpose of illustration.

Fig. 6 'is an enlarged detail view of the pilot burner.

F ig. 7 is a diagrammatic view of the electrical circuit connections.

Referrin to the drawings more particularly and y reference characters A designates the walls of a boiler having a series of burners B which are supplied with as (or other fuel) by a main supply pipe The fuel to the burners is controlled by a valve D, in the pipe C, this valve has a head 9, which is normally and yieldingly held closed by a spring 10, and is opened by the depressing of a stem 11 which extends upwardly through a brushing 12 in the neck of the valve.

Connected with the pipe C, and in advance of the valve D, is a plpe E, having a valve F, for controlling the supply of fuel to the running pilot pipe E1. The valve F is similar to but smaller than the valve D, and has a head 13 which is yieldingly closed by a spring 14 and is opened by depressing its stem 15. The tube or ipe E1 extends into the boiler and passes adJjacent to the ends of all the burners B so as to be in a lighting position with respect to them. And for this purpose it is provided with a series of perorations 16-throu h which the gas escapes to form a longitudinal series of pilot flames. The first of these flames is started, when the valve F is opened, b a continuously or permanently lit pilot, then, because of the closeness of the perforations 16, the flames will spread from one to the other until they reach the end of the pipe, thus 'ving a travelling or running action to ie pllot flames created by the perforations 16. The pilot Gis preferably provided with a Bunsen tip which extends just within the wall A far enough to ignite the near end of the running pilot El, but is preferably arranged almost entirely outside of the wall so as to be removed from the destructive effect of pilot G is connectedby `a tube 17 to the inlet side of the valve F,.,so as to be continuously su plied with fuel,y 'and is provided with a valve 18 `sus whereby the size of the pilot flame may be regulated as may'be required.

A casing 19, having a hinged cover 20, incloses the projecting ends of the valve stems 11 and 15, and is preferably secured to the necks of the valves D and F, as is also a bracket 21 which supports a motor 22. This motor may be of any suitable design, but is preferably a spring motor such as is commonly used to operate dampers and valves in connection with temperature control electric thermostats, wherein predetermined maximum and minimum temperatures will close circuits which will in turn permit or cause the motor to effect a predetermined movement. In the present instance, the shaft 23, of the motor 22, is so operated that for each time the motor is affected by a thermostat the shaft will describe a one-half rotation, and these semirotations are successively made in the same direction. The shaft 23, of the motor, drives a shaft 24, journaled in the casing 19, and is connected to this shaft by an insulated universal joint 25. The motor 22 is also insulated from the bracket 21, as at 26, so that electricity to the motor will not be grounded.

The valves D and F are respectively opened by a pair of levers 27 and 28 which act on the stems 11 and 15. These levers are pivoted, as at 29, and are normally held down by springs 30, Which springs are strong enough to depress the stems 11 and 15 against theresi'stance of the springs 10 and 14 when the levers 27 and 28 are free for such movements. The levers 27 and 28 are raised, so as to effect intermittent opening and closing of the valves, by a pair of cams 31 and 32 which are rigid on and rotate with the shaft 24.

As previously indicated, for each complete movement of the motor 22 the shafts 23 and 24 are turned one half a revolution. Conscquently the cams 31 and 32 will have two distinct positions. The first or primary positions of the cams is illustrated in Figs. 2, 3 and 4, and both valves D and F are closed, with a result that neither the main burners B nor the running pilot E1 are supplied with gas. When the shaft 24 is now partly rotated, either manually or by the thermostatically influenced motor 22, it will be seen (Fig. 3) that the cam 32 will release the lever 28, thus opening the valve F and supplying gas to the running pilot El, which is then immediately lighted by the continuously burning pilot G. A continued movement of the shaft 24 now releases the lever 27 from the end of the cam 31, thus causing the valve D to open and permitting gas to flow to the main burners B, where it is ignited by the running pilot El. This being done the function of the pilot El is, for the time being, ended, and, as the shaft 24 approaches its F f f" secondary position as shown in F 1g. o, the

1,sse,aes

valve D is still open, but the cam 32 has again raised the lever 28 thus closing the valve F. lYhen the room temperature has become raised to the desired degree, and the motor 22 is again started, to extinguish the main burner, to rotate the shaft 24 a half revolution thus turning the cams 31-32 from their secondary positions, back to the initial positions shown in Figs. 3 and 4. v

A safety device is provided in connection with the electric circuit system of the thermostatic control for the motor 22, and its object is to completely shut ofil the entire gas supply to the burners B and E1 if and when the pilot G should become accidentally ex# tinguished at any time. This device and its connection with the thermostat circuit may be described as follows:

The thermostat, which is designated as 'I in Fig. 7. is of any common and well known construction in which one circuit is closed when the temperature of the room is raised to a predetermined degree. whereby said circuit will start. the motor 22 to close the gas supply to the main burner, and when the temperature has then fallen to a predetermined minimum the thermostat will close another circuit which will influence the motor to open the gas supply to the main burner. The motor has three terminals 35. 36 and 37. the last of which is connected by a wire 38 to the negative pole 39 of a battery or suitable source of current 40. The terminals 35 and 36 are respectively connected by wires 41 and 42, to the thermostat, and these wires designate or comprise the olf and on circuits to the motor. Thus when circuit 41 is energized the motor is actuated so that the gas supply will be turned off, and when circuitV 42 is energizcdthe gas 'will be on. The positive current of electricity is normally supplied to the thermostat arm by a wire 43, extending from the positive pole 44 of the battery 40 a wire 45, connected to the thermostat T, an a thermal switch S, which is normally closed and connects the wires 43 and 45.

The thermal switch S comprises a bar or strip of bi-metal 46 which is rigidly secured at one end to the head end of the pilot tube G1. The bar 46 is composed of two fused pieces of metal having different coeflieients of expansion whereby the bar, as a unit, will be distorted or bent upon being subjected to different or variable temperatures. In the present instance the bar is secured to and extends adjacent to the tube G1 and is conseqnently influenced by the pilot flame which, when lit, keeps the tube G1 quite warm, but, it may here be noted, the bar 46 is outside of the casing A so that it will not be inuenced by the more intensive and destructive heat of the burners B and E1.

Under normal circumstances, i. e., with the pilot G burning, the bar 46 being warmed, will be held in Contact with the terminal 47 of the wire 45, but should the pilot G go out, so as to cool the tube G1, then the bar 46 will bend upward, breaking contact with 47, and making a new contact with the terminal 48 of a wire 49 which connects with the wire 41.

It will thus be seen that under normal circumstances the thermostat T will be effective to actuate the motor to its on position, by virtue of the complete circuit 40, 44, 43, 46, 47, 45, T, 42, 36, 37, 38 and 39; and when affected by a rise in temperature the thermostat will be effective to actuate the motor to its off position, by virtue of the circuit 40, 44, 43, 46, 47, 45, T, 41, 35, 37, 38 and 39. When the pilot Gis extinguished the Contact 46-47 breaks, and the positive current is no longer supplied to the thermostat which is thus rendered idle, with a result that the gas cannot be again turned on until the pilot G is first lit. This might be a dangerous condition, under certain circumstances, because if the circuit through S should be broken while the main burner is functioning then the thermostat would be ineffective to cut off the gas su pply when the maximum room temperature had been reached. This contingency is provided for, however, in the branch circuit 48-49. Thus, under the conditions mentioned, the bar 46 will be bent up until it makes a contact with the terminal member 48. There will then bea complete circuit through the elements 40, 44, 43, 46, 48, 49, 41, 35, 37, 38 and 39. which will influence the motor into turning the valves D and F into-their closed positions. Relighting the pilot G will automatically restore all the parts and circuits toY their initial conditions.

It is understood that suitable? modifications may be made in the general design and structural details of the invention as herein shown, provided, however, that said modifications come Within the spirit and scope of the appended claims. Having now therefore fully shown and described my invention, what I claim to be new and desire to protect by Letters Patent is:

1. The combination of a valve controlled main burner, a pilot for lighting the main burner, a thermal switch arranged to be influenced by the pilot, a motor foropening and closing the valve of the main burner, a thermostat connected with said motor by two circuits one of which includes therein the thermal switch, said switch being adapted, upon the extinguishing of the pilot, to open one circuit to the thermostat and close a direct circuit to the motor to thereby effect closing of the valve.

2. The combination with a pair of yieldingly closed gas valves, one of whichcontrols the supply of gas to a series of main-burners and the other controls the supply offgas to a secondary burner, of a pair of lever acting members for opening the valves, and a pair of cams for controlling the movements of said levers one in advance of the other.

3. The combination with a pair of yieldingly closed gas valves one of which controls the supply of gas to a main burner and the other controls the supply of gas to a secondary burner, of a pair o spring actuated members normally tending to open thev valves, and means for controlling the movements of said members.

4. The combination with a pair of yieldingly closed gas valves, one of which controls the supply of gas to a main burner and the other controls the supply of gas to a secondary burner, of a pair of spring actuated members normally tending to open the valves, and means for controlling the movements of said members, comprising a pair of cams carried by a rotatable shaft.

5. The combination of a main burner, a valve for controlling the supply of fuel there to, a second burner for lighting the main burner and having a valve for controllingits fuel supply, both of said valves being connected to a common source of fuel supply, a pilot burner for lighting the second burner when its fuel valve is open, and motor actuated means, operative in cycles, one cycle to successively open the valves of the second and first burners and and then close the valve of the second burner, and the following cycle to close the valve of the first burner without disturbing the closed condition of the valve of the second burner.

6. In combination a main burner having a valve for controlling the supply of fuel thereto, a second burner having a valve for controlling its fuel supply and arranged, when burning, to lightl the main burner, a pilot burner for lighting the second burner, and temperature responsive means operative in successive cycles, for controlling the valves, and adapted, upon an initial cycle movement, to successively open the valve of the se "1 burner, open the valve of the main burner and then close the valve of the second burner, and upon a succeeding cycle to close the valve of the main burner without disturbing the closed condition of the valve of the second burner.

In testimony whereof we affix our signatures.

DALE F. MCFARLAND. REX E. DAVIS.

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