US2008749A - Heat regulating device - Google Patents

Description

July 23, 1935 L. L. CUNNINGHAM 2,003,749

HEAT REGULATING DEVICE Filed May '7, 1928 w I J 7 BURNER APPARATUS l PILOT PIPE I I7 I (A: IGNITION MEANS) 37 I8 can /9 6 l5 CONTROLLED BY TEMPERATURE 9 "Z BURNER 7 3.9 F

l ire-r 36 QI I I :8 42 /2 i a 1' V p 60 6 VALVE 2'5 CONTHOL D B! By TIMPERGTURE 5/ OF ROOM BURNER Mo-roR HEA TING Fuzz. 601v TROL- AN%R I, 95 IGNITION MEANS CONTROLLED BY 9/ TEMF'ERA TuRE 71r sun/v5? LEW L. CUNNINGHAM Alma/"n aye Patented July 23, 1935 UNITED STATES PATENT OFFICE HEAT REGULATING DEVICE Lewis L. Cunningham,

Minneapolis, Minn., as-

Delaware Application May 7, 1928, Serial No. 275,773

2 Claims.

This invention relates to improvements in heat regulating devices, and has for general and broad objects to provide an electro-magnetically operable means for controlling a heating apparatus and an electro-thermal timing device in such manner that temperature changes at or in the heating apparatus will operate a control switch so that a maximum degree of energization of the electromagnetic device and/or timer can be obtained when the temperature of the burner reaches a predetermined minimum, and such that a minimum energization of the electromagnetic device and/or timer will take place when the temperature of the burner apparatus reaches a predetermined maximum.

Specific objects are to provide a double coil electro-magnetically operable device and so arrange a circuit that the magnetic force can be varied according to the temperature of the heating apparatus, and so that a warp switch as a timing device can be operated to continue operation of the burner apparatus when flame is ob-' tained or, in other words, when ignition is successful, and such that this device can be made inoperative when ignition is successful. Another object is to so control the magnetic force that under some conditions the magnetic device has suflicient energy to control the heating apparatus in a certain manner, and under some conditions does not have suflicient magnetic energy to control the burner apparatus, in that manner. Another object is to use an electro-magnetic device in a manner to cause a thermally operable switch, for example a warp switch as a timer device to be energized or de-energized respectively to perform or not perform its operation according to the temperature condition at the burner of the heating apparatus. Another object is to control the electro-magnetic means and the burner apparatus by means of switches which are either magnetically or thermally operable.

Features of the invention include the broad idea of using a magnetically operable device and varying its magnetic force for the purposes above mentioned, along with all details of construction and arrangement of the apparatus per se, and the electrical connections or circuits.

Features of the invention will be set forth in the description of the drawing forming a part of this application. and in said drawing:

Figure l is a diagrammatic view showing an application of the invention in which the electromagnetic means is applied to operate an oil valve;

Figure 2 is a diagram showing a modification in which the electro-magnetic means is applied to operate a relay.

A very simple application of the invention is shown in Figure 1 of the drawing, in which the power lines are indicated respectively at I and 2. The burner is indicated at 3. It will be understood that the term burner apparatus as used herein includes all those parts such as a blower motor, pilot pipe, ignition means, and oil means etc., needed to supply heat. In this instance, the burner apparatus may be viewed as including the burner 3, pilot pipe 4 and fuel supply line 5. The control of the fluid through the supply pipe is obtained by electro-magnetic means designated 6, in this instance, an electro-magnetically operable valve. It is conceivable that the electromagnetic control may have many forms and may be connected mechanically or electrically to control the operation of the burner apparatus. Nevertheless the specific form and arrangements are also claimed. This electr'o-magnetically operable means is therefore connected to control the burner apparatus and the said means herein includes two coils, designated respectively 7 and 8. These coils may be arranged in other ways, but the specific arrangement is also a feature of the invention. The coil 1 may have less resistance than the coil 8. In any event, when both coils are in circuit the magnetic pull is reduced to such a degree that the core 9 cannot be caused to open the valve, but if the valve is once open it can be held open when both coils are in circuit. The coil 1 is capable of opening the valve.

A warp switch as one form of electro-mechanical timing device includes the heating coil I 0, and the bimetallic element l I, in this instance closing against a contact l2 when cold. As shown in the drawing, the heating of this device is in series with the electro-magnetic means. The circuit will be described herebelow.

A double contact switch (in this case thermally operable) is arranged to be controlled by burner temperatures, and in practice is quickly responsive to presence or absence of flame. This device includes a bimetallic element l5, two spaced spring arms respectively lS-Il, electrically connected at l8 and insulated as at H! from the element IS. The spring arms operate between contacts 2B-2l. In this instance. the arrangement is such that the contacts are alternately made. and each engages its contact before the other disengages. The reason for this will be explained.

A third switch in this case thermally operable includes the thermal element 25 operating against a lever arm 23, pivoted as at 21 and carrying at the opposite side of its pivot a mercury switch 23, having terminals 303|. The following circuit connections are provided. Conductor 35 connects on side 2 of the main line and with the terminal 30. The terminal 3| is connected by conductor 35 with contact l2. The opposite side of the circuitcontrolling member H is connected by conductor 31 with one terminal of coil 1. In this instance, coils 1 and 8 are connected together as at 39. It will be understood that the coils can be differently arranged. The opposite terminal of coil 8 is conected by conductor 40 with contact 20. Contact 2| is connected by conductor 4| with one terminal of the heating coil I0, and the opposite terminal of the heating coil is connected by conductor 42 with the junction point 39 of coils I and 8. Both spring arms |6-l'| are electrically connected with the opposite side of the main line by conductor 45.

Itwill thus be seen the circuit connections are such that when the mercury switch closes (as when heat is desired) at 30-3| and when the thermallyoperabledevice I5 is cold (no flame), and is closed at 2|, the electro-magnetic means is energized to start the burner apparatus, in this instance, by raising core. 9 to open the valve and at the same time theheating coil I is energized. Suppose the burner appartus effective tosupply the heat, so that contacts iii-20 are closed. Then the heating coil I0 is shunted out and therefore further operation of the timing device is prevented; That this .is so may be seen by tracing the-circuitas follows: Main line 2, 35, 30, 3|, 36, I2, 3|, l, 39, 42, I0, 4|, 2|, I1, 45 to line I. It will be noted that in this instance the warp switch blade coil 1 and coil ID, are all in series across the line. On energization of the mill, the valve is opened.

Let it be supposed that there is an ignition failure (no flame produced). At-the end of a predetermined time (because heat is being supplied at the coil l0) switch M will be opened, the coil I will be de-energized and the valve will close. 1 Under these conditions an inspection of the apparatus and repair ofthe same will be in order. However, suppose that ignition is successful, and that therefore heatis produced by the burner apparatus. The double contact switch moves, in this instance, to the left', closes at I6, 20 and then opens at H, 2|. The valve remains open, and that this is true can be seen by tracing the circuit as follows: Main line 2, 35, 30, 3|, 36, I2, 31, I, 8, 40, 20, I6, 45 to line Under these conditions, it will be noticed that no current will pass through the heating coiland the magnetic pull upon core 9 is weakened, but is still suflicient to hold itso that fuel is supplied. In practice, the response of the element to temperature conditions at the burner apparatus is prompt. The magnetic characteristic and arrangement of the coils is such that if when the contacts I6, 20 are making contact, they are deenergized, the core 9 will cause a closure of the valve and on reenergization, the valve cannot again be opened while l6 and 20 are making circuit. However, the element l5 by cooling will shortly make contact at IT, 2|, in which instance, only the coil 1 will be in circuit and the valve can be opened, if 3|, 30 are closed. If this occurs, and if ignition is not successful, the coil ID will eventually heat sufiiciently to open the switch l, as in the first case.

Therefore, the arrangement is such that when one contact of the doublecontact switch is closed,

(in this instance when no heat is being supplied) a comparatively large current passes to operate the electro-magnetic device, as well as to furnish heat for the coil of the timer. On the other hand, after heat has been furnished, the other contact of 'the double contact switch is closed and both coils are in circuit. Under these conditions there 'is sumcient magnetic force to hold the movable core in its previous position, but the timer can receive a very small current or no current at all, and therefore is not operative after heat is supplied by the burner apparatus. By the use of the present invention an alternating current can be'used, and the warp switch'or timer coil can be put in series with the coils of the magnetic device or relay or similar device, without danger of over-heating and destruction of the coil.

Moreover, a burner regulating device is provided which complies with one of the most importantrequirements of an oil burner control circuit, namely that an electrical failure of any of the contacts. or conductor in the safety or timer circuit, will result in a shut-down of the oil bumer due in some instances to the stopping of the motor or interruption of the fuel supply or both.-

Another valuable application of the invention is illustrated in Figure 2, in which the magnetically operable means includes a relay having two coils, or which is operable by two coils. The broader features of the device herein shown are identical withthose of Figure 1. The main lines are shown at 50, 5|. The burner apparatus in this instance includes a motor 53, a fuel control or ignition means 54, which is energizable whenever the motor is energized. The motor, the fuel control and/or ignition means may be considered as constituting a burner apparatus, which apparatus as before stated, must have all the parts necessary to supply and maintain flame. The motor 53 will be considered the burner motor. The relay, (as an electro-magnetic means) includes the core 55, armature 56, coil 58 and coil 59, the coils being, in this instance, connected at 60. The warp switch, as a timer device, includes the heating coil BI and the bimetallic warp member 62 cooperative with contact 63 and closing it when'cold. The double contact switch, operable as a result of heat furnished by the burner apparatus, is of the mercury type and is moved by a thermally operable means indicated at 65, engaging against a lever 66 of the tube 61. The lever is pivoted at 68 and has a spring 69 urging it against a stop 10. The mercury switch has a terminal 1|, an L-shaped terminal 12, and a third terminal 13. The mercury is indicated at 14. There is also herein provided, as in the first form of the invention, a thermally operable device (which may be manually operable) comprising a thermal element 16 operative against a lever 11, pivoted at 18, carrying its upper end tube 19, and having a spring 80 urging the lever against a stop 8|. The mercury is indicated at 82. The terminals are indicated at 83, 84. Circuit connections are arranged, so that when the switch 82 as well as one of the contacts of the double contact switch are closed, the electro-magnetic means is energized to start the burner apparatus and the heating coil is also energized, so that if the burner apparatus is effective to supply heat, said double contact switch closes its other contact to prevent opera tion of the timing device.

The circuit connections are as follows: Line 50 is connected by conductor 90 to one side of the motor 53, and the other side of the motor is connected by conductor 93 with line 5|.

nected by conductor SI and relay armature which operates against a contact 92, in turn con- The ignition coil 54 of the magnetically operable fuel device is connected as shown so as to be energized when the motor is energized. Contact 83 is connectedlby conductor 95 with main line 5|, and tenninal 84 is connected by conductor 96 with contact 53. Warp switch blade 62 is connected by conductor 91 with terminal of the coil 58. The terminal of the coil 59 is connected by conductor I00 with terminal I3 of the double-contact switch. Terminal I2 is connected by conductor II with line 50. Terminal II is connected by conductor I02 with one end of the heating coil BI, and the opposite end of the heating-coil is connected to the junction point of coils 59, 58 by conductor I113.

The operation of this device is substantially the same as above described for the construction of Figure 1. Assuming the switch 82 to close and beginning at line 5 I, the current takes the following course: 95, 83, 84, 96, 53, 52, 91, 58, 60, I03, 6|, I02, II, 12, ilil to line 50. As the result, coil 55 is energized, armature 56 is closed and current to the motor or burner apparatus is supplied. Simultaneously heating current is supplied to the coil 6i. If ignition is unsuccessful, switch 62 will open at the end of a predetermined period, which is the safety timing, or trial ignition period. If ignition is successful, the mercury switch will close contacts I2, I3, coil 59 will be put in circuit with coil 58 and coil 5| will be inoperative to open switch 62. Armature 56 will be held closed, and therefore the burner apparatus will continue to operate.

The arrangement is therefore such that if the burner apparatus is effected to supply heat, the double contact switch closes one contact before opening the other to prevent operation of the timing device, and the arrangement is further such that the magnetic effect of the electro-magnetic means'is so modified that although the burner apparatus remains operative after closure of the second contact, or, in this instance, of contact I2, I3, yet if the magnetic means is once de-energized or momentarily de-energized, re-energization is impotent to close the relay (the armature of which will have fallen open), to obtain operation of the burner apparatus to supply heat (because the armature 56 cannot close with its contact 92). This is a valuable feature of the invention, and is shown for both forms of the invention.

It will be understood that in all instances, the arrangement of the double contact switch will be such that in changing from one contact to the other the circuit cannot be momentarily broken or one circuit cannot be broken before the other is made to allow de-energization of the electro-magnetic means.

The circuit arrangement including the coils is such that when a flame is present, and when both coils are energized, the magnetic pull is so reduced that no operation of the electro-magnetic means to start the ignition apparatus can take place, and no current to the heating coil can be had, sufficient to obtain a safety timing operation of the warp switch to shut down the heating apparatus. The circuit and coil arrangement is also such that if the magnetic device has been energized and its movable core moved to that position which supplies fuel or starts operation of the ignition appa atus, on presence of flame the core will be held in this position.

If a flame responsive double-contact switch device is used, which acts quickly to change from one contact to another, as compared. with the speed of drop of the plunger of the electro-magnetic valve for example, so that the change is made before the plunger can close the valve, or before it can move, after release, no overlapping switch arrangement is necessary, as above described for both applications of the invention. However, if this is not so, then contacts must be arranged so that one contact is made before the other opens. This overlapping contact can be obtained either by the spring arrangement of Figure 1 or by using the mercury tube of Figure 2. However, it will be conceivable that a single switch arm operating between two contacts can be used if the speed of travel between the contacts sumciently exceeds that of the rate of motion of the electro-magnetic means.

In all instances, the coils of the electro-magnetic means, for example the relay or magnetic valve, can be put in series in such manner that the timer coil can receive sufficient heat to eventually cause opening of its switch to shut down the motor, or in another instance cannot receive suflicient heat for that purpose. Broadly, in both instances, there is an arrangement for the fuel supply or motor control means whereby a coil or coils can be controlled to vary the magnetic effects and increase these effects, for example, when the flame responsive device is making on the cold side, and decrease them when making on the hot side.

Another valuable feature of the invention is that it provides means whereby increased heating effects can be had at the warp switch when one contact is making, in order to obtain a trial ignition period or timing cycle to shut down the motor if all is not working properly, or when the other contact is making to decrease the heating effects and prevent a shut-down if all is operating properly. These are considered important broad features of the invention, and there is no intention to be limited to details of construction although such details are in all cases considered features of the invention.

I claim as my invention:

1. A system of the class described comprising,

in combination, an electrically actuated fuel feeding means, a switch in circuit with and for controlling energization of said fuel feeding means, combustion responsive switching mechanism having first contacts which are closed in the absence of combustion, and second contacts which are closed in the presence of combustion prior to the opening of said first contacts, a thermal time switch, a heater element for actuating said switch upon energization for a time period, a main control switch, and a single high impedance sole noid having a portion of its turns connected in series with said first contacts, said heater element, said time switch, and said main switch and operable when so energized to close said fuel feeding control switch, and having all of its turns connected in series with said second contacts, said time switch and saidmain switch, and when so energized it is operable to hold said fuel feeding control switch closed, but is incapable of closing said switch.

2. A system of the class described comprising, in combination, an electrically actuated fuel feeding means, a normally open switch in circuit with and for controlling energization of said fuel feedseries with said first contacts, said heater element, said time switch, and said main switch, and operable when so energized to close said fuel feeding control switch, and having all of its turns connected in series with said second contacts, said time switch and said main switch, and when so energized it is operable to hold said fuel feeding control switch closed, but is incapable of closing said switch.

LEWIS L. CUNNINGHAM.

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