US2524139A - Liquid fuel burning apparatus involving a multiple sump pot type burner - Google Patents

Description

Get. 3, 1950 M. RESEK LIQUID FUEL BURNING APPARATUS INVOLVING A MULTIPLE SUMP POT TYPE BURNER 2 Sheets-Sheet 1 Filed Jan. 3, 1947 6600000009006 c Q Q0 0 0000 00 000000 INVENTOR, MZ/c Resek, 4w MM 14770EN5Y5 Oct. 3, 1950 M. RESEK LIQUID FUEL BURNING APPARATUS INVOLVING A MULTIPLE SUMP POT TYPE BURNER Filed Jan. 3, 1947 2 Sheets-Sheet 2 I JNi ENIUR,

Patented Oct. 3, 1950 LIQUID FUEL BURNING APPARATUS IN.-

VOLVING A MULTIPLE SUMP POT 'rYrE BURNER Marc Resek, Cleveland Heights, hio,: assignor to Perfection Stove Company, Cleveland, ;0hio, a

corporation of Ohio Application January 3, 1847, Serial No.,72 0,;014

Claims. 1

This invention relates to improvements in vaporizing liquid fuel burners of the pot type, and of the class in Which, by suitable electrical control means or otherwise, the burners are caused to operate at different stages, for example, at low or pilot fire, intermediate fire and high fire.

In order that my improvements and their advantages may be more readily and thoroughly understood and appreciated, I shall first explain in what respects theprevailing pot type vaporizing burners are more or less unsatisfactory or deficient.

In the conventional vaporizing burner of the aforesaid type and class, liquid fuel is supplied by gravity to the burner pot from a, receptacle wherein a fuel level is maintained by a float controlled valve or other means, normally about three-fourths of an inch above the plane of the bottom of the pot. Thus, acorresponding maximum fuel level is established for the pot. The rate at which the fuel is fed to the pot for the purpose of producing pilot, intermediate, or high fires is customarily controlled by a valve or valves.

Because the fuel is so fed and controlled, the rate of feed changes as the viscosity of the fuel varies. The variation in the viscosity of the fuel results, in part, from temperature changes, and in part because of non-uniformity of fuels supplied from time to time by the fuel distributors. This variation in viscosity causes trouble in maintaining a satisfactory pilot fire, and in controlling the size of the higher fires, which latter smoke when the viscosity is low, and do not give enough heat when the viscosity is high.

Because the maintained fuel level in the aforesaid receptacle is above the plane of thebottom of the burner pot, the flow rate tends to change as the fuel accumulates in the pot, due to the fact that the gradually increasing liquid head in the latter opposes the incoming fuel. The amount of fuel in the burner pot during operation of the burner, or, in other words, the rate of consumption, depends on a number of factors including the volatility of the fuel, the temperature of the burner pot (which is influenced by weather conditions), the draft through the burner, and other circumstances,

Now, upon first lighting the burner, the fuel feed is normally in excess of the rate at which the fuel is consumed so that a pool gradually builds up in the bottom of the-pot. Or if the burner is not lit promptly, or if it is slow incoming up to normal operating temperature, this pool often becomes so large as to cause an excessively high fire when the burner finally heats up.

This high fire produces smoke, excessive heat, and sometimes even a dangerous condition.-

Further, with respect to prevailing burners of the type in question, in order to keep the amount of fuel which can accumulate in the pot at'a minimum, the bottom of the pot is usually made sloping downward toward the center. Therefore, when the burner is operating normally with a small pool due to .the consumption rate approaching the rate of flow of the incoming fuel, only arather small surface of the fuel is exposed for vaporization, thus necessitating a comparatively high temperature in order to evaporate the fuel fast enough for maximum fire. This high temperature has a tendency to crack the fuel, resultingin the formation of coke and carbon on the bottom of the pot and at the fuel inlet. In time this formation interferes wtih the proper amount r t at.

of fuel being supplied to the pot, reducing maximum or high fire to considerably less than that appropriate for such stage operation.

Asa result of comparatively recent improvements in pot. type burners of the class in question a satisfactory pilot fire is produced by admitting and confining the fuel to an enclosure of a so-called pilot skirt adjacent the center of the pot, Said skirt may take the form of an open top cylindrical or frusto-conical perforated wall. For pilot fire, the fuel is fed at a sufficiently low rate to cause it to burn entirely within said skirt while the higher fires are produced by increasing the feed enough to cause the fuel to flow beyond the confines of said skirt. However, when the burner is operating on pilot fire, it frequently happens that the fuel feed-tends to exceed the which the fuel is consumed, resulting in the fire occurring both on the inside and, to a lesser degree, on the outside of the skirt, thus producingan uncontrolled, unsatisfactory flame created in the zone thus affected. It is apparent, therefore, that combustion conditions would be improved if the lowest of the air openings (through which so-called primary air is admitted) were located closer to the bottom of the pot, and, at the same time, provisions were made for preventing overflow through said openings.

Now, with the foregoing in mind, it may be said that the fundamental aim of my invention is to eliminate the above enumerated objections from liquid fuel burners of the type and class described, and to these ends I provide, in the more complete present preferred embodiment of the invention, apparatus comprising the following: a pot type burner in which the bottom of the pot is characterized by a plurality of well defined sumps; liquid fuel feeding means including a container wherein a substantially constant liquid level is suitably maintained below the plane of the bottoms of said sumps; receptacles corresponding in number with the sumps and located in proximity to said container; a conduit through which fuel flows by gravity from each receptacle to the corresponding sump; volumetric feeding means for transferring measured quantities of fuel. from the container to each of the receptacles, with electrical control mechanism for effecting the operation thereof, and an overflow for the low or pilot fire sump which determines the maximum liquid level therein and returns any overflow fuel to the aforesaid container.

Such an embodiment of the invention is illustrated in the accompanying drawings, wherein like reference characters designate like parts in the two views, and as I proceed to describe the invention in detail by reference to said drawings,

further and more specific objects will become apparent.

In the drawings, Fig. 1 is a vertical section in offset planes through liquid fuel burning apparatus constructed in accordance with my invention, the different planes of section being indicated by the line I--i of Fig. 2, and Fig. 2 is a sectional plan on the line 2-2 of Fig. l, the latter view including a diagram of the electrical control mechanism for the fuel feeding means.

The burner pot, designated generally by the reference numeral l, comprises, according to the present design and construction, an annular upwardly convergent top wall 2, a cylindrical peripheral wall 3 and a circular bottom wall 4. The latter wall is divided into a central sump 5, an intermediate sump 6, and an outer sump I, by annular barriers or ridges 8 and 9. Rising from and opening through the bottom wall 4, centrally thereof, is an air tube in that is surmounted by a perforated distributor head H; and surrounding said tube and head and enclosing the sump 5 is a perforated frusto conical wall or pilot skirt I2. This wall or pilot skirt is connected to the distributor head by a cross member l3 and held thereby with its lower end over the barrier or ridge 8, said lower end being shown as provided with notches I l so that fuel may overflow freely from sump B to sump 5. Ridge 9 is shown as higher than ridge 8.

The burner pot is located within a cylindrical casing 15 that is closed at its lower end by a horizontal circular wall l6. An annular partition [1, and a downwardly converging member I8 which terminates at its lower end in a cylindrical neck I9 that is interlocked with the top wall 2 of the burner pot, divides the casing [5 into an air compartment 2!] therebelow, and a combustion chamber 2| thereabove. Air is admitted to the compartment 20 through holes 23 in the wall i6 4 adjacent the edge thereof, and through a central hole 24 of said wall, and the lower portion of the burner pot is protected from the cool air entering through the holes 23 by an annular shield 25. The hole 24 insures an ample air supply for the tube l0 and distributor head H. The peripheral wall 3 of the burner pot is provided with air admitting openings 28, and the tapered portion of the member 18 and neck I9, with openings 29.

Located to one side, and near the bottom, of the casing I5 is a container 35 to which liquid fuel is supplied from a suitable source (not shown) through a pipe 36. Admission of the fuel to the container is controlled by a valve 3? that is operatively connected to a float 38 by which said valve is closed when fuel has accumulated within the container to the level indicated by the line a in Fig. 1. It will be observed that the fuel level a is below the horizontal plane of the bottoms of the sumps 5, 6 and l.

The front wall of the container 35-that is, the one nearest the casing |5-is designated 40, and on the outer side of said wall are receptacles 5 8 and I that correspond, respectively, with the sumps 5, 6 and 7, and the receptacles communicate with said sumps through pipes 5 6 and l An overflow pipe 42 leads from the sump 5 to the bottom of the container 35, the inlet end of said pipe rising a distance above the bottom of the sump 5 so as to define a maximum fuel level therein.

Shown as secured to an end wall 45 of the container 35, and to plates 46 and 41 that are built into the container and are parallel to said wall, are electric motors of the clock type designated 5, 6 and 1. As appears in Fig. l, the plates 46 and 41 do not extend to the bottom of the container. Consequently, the same fuel level prevails throughout the vessel. The shafts of said motors have secured to them cranks 5B, the pins whereof are operatively connected, through links lit, with trough-like dippers 5 6 and 1 Each dipper, adjacent its forward or discharge end, is pivoted on a shaft 53 that is supported by and between the side branches of a yoke 54. Said branches are bifurcated at their lower ends and are guided for vertical movement on the front wall 40 of the container 35, and the yoke is adapted to be adjusted vertically by means of a screw 56 that is threaded through the top of the yoke. Each screw is freely rotatable in an aperture in a cross bar 58 that is fastened to the top front corners of the end Walls of the container 35, the heads of the screws resting upon said bar.

From the construction just described, it is evident that, as the cranks 59 are driven by the motors, the dippers 5 6 and i will be oscillated on the shafts 53, between low position (as indicated in Fig. 1) wherein the rear end of the dipper descends below the liquid level a, and a high position in which the dippers incline downwardly and forwardly to discharge the liquid picked up thereby into the receptacles 5=-, 6 and 1. Obviously, the quantity of liquid discharged at each stroke may be regulated by the adjustment of the yoke 54 through the medium of the screw 56.

Illustrated diagrammatically in Fig. 2 is an electrical control system for the motors 5 6 and 1", said system including a room thermostat 60 that is located in the space to be heated by the apparatus. 6| is a transformer, and 62 and 63 denote relays which, when energized, close the respective switches 15- and l Current is supplied from a suitable source (such as the house circuit) to a circuit including the pica-4, 13

motor 5 and represented-by conductors 65 and-66.

Accordingly-so long -ascurrent is supplied tothe system, motor 5 will operate-- to oscillatethe dipper 5 and transfer-liquid from the container 35 to the receptacleS and'thenc -through pipe 5 to thesump 5. Assuming the burner islit,'a pilot fire of substantially constant volume will thusbe maintained within the-area of the pilot skirt I 2, air to support combustion being'supplied thereto through the distributor head I l and, from the surrounding portion'of the pot, through the perforations in, and over-thetopof, the*pilot skirt. The practically unchanging size of the pilot fire results from the well defined limits of 'the sumpfi and the overflow which prevents an'excessive accumulation'offuel therein.

Branching off from the'circuit represented by the conductors 65 andtt is one comprisingconductors 6? and 68 and including the'primary coil 6W of the transformer 6|. A conductor 10 leadsv said element, under the influence of a falling temperature, swings a'given distance to "the'left, as the parts are viewed in the drawings. When the bimetal element of the room thermostat is caused to swing a further given distance inthe same direction under the influenceofacontinued fall in temperature, it engagesa contact 16 from which a conductor 1'! leads to the remaining end of the winding of the relay 63. A'branch of the first described circuit, represented by conductors 80, 8! and 82, includes the relay switch 6 and the motor 6'; and another branch circuit, represented by conductors 85, 86 and 81, includes the relay switch 1 and the motor 1;

Considering further the operation of the burner (thus far assumed to be operating on pilot fire with the switch constituted of the room thermostats?) open, as indicated in the diagram of Fig. 2), let it be supposed that, under the influence of a relatively low outdoors temperature; the temperature to which the room thermostat is subjected drops sufficiently to cause'the bimetal element of the thermostat to swing to the left and engage the finger 75 with the contact 14. Current will now be supplied from the secondary coil of the transformer, to the winding of the relay 62 through the appropriate one of the above'described circuits, thereby to close the switch 6 and supply current from the house circuit of usual voltage to the motor 6,"resultin'g in the operation" ofthe dipper 6 So long as the room thermostat retains the finger in engagement with the contact la, the clippert will continue to feed fuel from the container 35 to the receptacle 6 and thence through the'pipe 6 to the sump 6. The fuel in the'sump 6 will be ignited from the pilot flame, thereby to enlarge the fire to intermediate stage, bein the product of the two sumps 5 and I 6. This condition may continue until the temperature affecting the room thermostat is boosted" sufiiciently to cause the bimetal element of the thermostat toswing to the right and withdraw the finger it from contact l4,- returning the burner tolowor pilot fire operation. on the other hand,

should the-heat produced "by the "apparatus be consumption? and"willnot"accumulatas'readily insu ificient to check 'the i falling temperature-'- as influenced by outside conditions, the bimetal element 'of the room thermostat will swing further to the left until it engages the contact 76, Where- -upon the circuit will be closed through the coil of 'therelay 63, causing said relay to close the switch-l and thereby supply current to the motor l.' Now, with this motor in operation, the dipper I -will be oscillated to transfer fuel from the container to'the receptacle 1* and thence, through the pipe l to the sump J. The fuel admitted to the sump 1 will vaporize and ignite, thereby placing the burner in high ormaximum fire operation. Obviously, as the temperature affecting "the room thermostat rises, the circuits to the motors 6 and 1 will be opened in reverse'order to their'closing asabove described and, until the temperature again falls, the apparatus will operate at low or pilot fire stage.

20 apparatus, when the burner is operating at either intermediate or high fire stage, the fuel is vapor- :ized from heat radiated from the flame above or "As understood by those acquainted with such conducted to the fuel by the burner parts. Primary air, entering through the openings 28 in the peripheral wall of the pot, commingle with the vapors to produce a mixture that becomes highly combustible when joined-by the secondary air entering through the openings 29 in the neck l9 and adjacent portionof the member I8, the diluted mixture burning vigorously in the combustion'chamber 2!.

From the foregoing disclosure of my invention, and its comparison with prior liquidfuel burning apparatus of the same type and class, it will be seen that my improvements aiford many advantages among which are the following:

'There is no danger of flooding the burner or of having an excessively high fuel level therein, first, because the maintained fuel level in the container 35 is below the plane of the bottom of the burner pot, and, secondly, because the overflow returns excess liquid to said container. This obviates the unfavorable conditions sometimes encountered in prior burners when starting.

'Due to the fact that the maximum fuel level in the burner can never be higher than the barriers or ridges that define the sumps, it is practical to locate the lowest of the air openings in-the peripheral wall much closer the bottom of the pot than is the case in prevailing pot type burners, thus improving combustion condi- "tions.

Because the overflow tube is below the barrier or ridge defining the pilot sump, the fuel feed for pilot fire operation remains within the confines of the sump, and cannot, as heretofore, spread out over the bottom of the pot and create *a bad flame condition.

Due to the use of volumetric fuel feeding means, the feeding rate is, entirely independent of the viscosity of the fuel and is not affected 'by the presence of dirt or other foreign matter in the fuel.

The large surface area of the fuel, resulting from the plurality of independent sumps which practically cover the'entire bottom of the burner pot, facilitates vaporization and allows the burner'to be operated at lower temperatures, hence tending to reduce carbonization.

By the use of the overflow return, heavy ends of the fuel, not vaporized at thetemperatureof the burner; arerecirculated and kept in suspension (when the feeding Irate. exceeds the rate "of in the bottom of the pot as they do in prevailing burners of the same type, where such heavy ends form gummy carbon deposits. Also, since the fuel enters my improved burner through three feed pipes, the aggregate ultimate deposit will be divided between the three entrances, thus approximately tripling the length of time before it becomes necessary to clean the burner of said deposits in order to maintain proper fuel flow.

Having thus described my invention, what I claim is:

1. In liquid fuel burning apparatus of the class described, a burner pot having barriers in the bottom thereof defining a plurality of sumps, said sumps being of different sizes, the smallest constituting a low fire sump, overflow means by way of which fuel from the other sumps is capable of overflowing into the smallest sump, a source of liquid fuel supply below the horizontal plane of said sumps, a plurality of conduits, one for each sump, for conveying fuel by gravity from said source to said sump, means individual to each conduit for transferring fuel from said source to said conduit, an overflow means for said smallest sump having its overflow edge below the barrier defining said sump and which determines a maximum liquid level in said smallest sump below that of the other sumps, and fuel conducting means communicating at one of its ends with the last mentioned overflow means and at its other end with said source and arranged to return fuel by gravity from the former to the latter.

2. The combination defined by claim 1, plus: a pilot skirt rising within the burner pot from the bottom of the latter and enclosing said smallest sump.

3. The combination defined by claim 1, plus: a pilot skirt mounted upon and rising from the bottom of the burner pot and enclosing said smallest sump, and air conducting means having a receiving end that opens outside the burner pot and extending into the space enclosed by said skirt for delivering air directly thereto.

4. In liquid fuel burning apparatus of the class described, a burner pot including a peripheral wall and a bottom wall, barriers dividing the bottom wall into a plurality of sumps, a fuel supply conduit for each sump enterin the same through said bottom wall, means individual to each conduit for feeding fuel therethrough, the sumps varying in size, the smallest constituting a pilot sump, said barriers being of such relative heights that fuel from the other sumps is capable of overflowing into the pilot sump, an overflow means for the pilot sump having its overflow edge below the top plane of the barrier defining the pilot sump, a pilot skirt rising from the last mentioned barrier, and air conducting means having a receiving end that opens outside the pot and extending into the space enclosed by said skirt for delivering air directly thereto.

5. In liquid fuel burning apparatus of the class described, a burner pot including a cylindrical peripheral wall and a circular bottom wall, annular ridges dividing the bottom wall into a plurality of concentric sumps, the central one constituting a pilot sump, said ridges being of such relative heights that fuel from the other sumps is capable of overflowing into the pilot sump, a fuel supply conduit for each sump, means individual to each conduit for feeding fuel therethrough, an overflow means for the pilot sump having its overflow edge below the plane of the .top of the ridge defining said pilot sump and determining the maximum liquid level in the pilot sump, a pilot skirt rising from the ridge surrounding the pilot sump, and air conducting means having a receiving end that opens outside the pot and extending into the space enclosed by said skirt for delivering air directly thereto.

6. In liquid fuel burning apparatus of the class described, a burner pot, a liquid fuel container, means maintaining a substantially constant liquid level therein, the container being so related to the burner pot that said liquid level is below the plane of the interior bottom of the pot, conveying means having its receiving end above the maximum liquid level in the pot and its other end communicatively connected to the pot and through which fuel flows by gravity to the pot, volumetric feeding means for transferring measured quantities of fuel from said container to said conveying means, overflow means having its receiving end located in the pot with its overflow edge at a given elevation therein, and fuel conveying means communicating at one end with said overflow means and at the other with said container and arranged to return overflow fuel by gravity to said container.

7. In liquid fuel burning apparatus of the class described, a burner pot having barriers in the bottom thereof defining a plurality of sumps, a fuel container, means maintaining a substantially constant liquid level therein, the container being so related to the burner pot that said liquid level is below the plane of the interior bottom of the pot, a plurality of receptacles, one corresponding to each sump, a conduit through which fuel flows by gravity from each receptacle to the corresponding sump, volumetric feeding means for transferring measured quantities of fuel from the container to each receptacle, operating mechanism for said feeding means, and an overflow means for one of said sumps having its overflow edge below the plane of the top of the barrier defining said sump, and'additional overflow means by way of which fuel from the other sumps is capable of overflowing into the one last mentioned.

8. The combination defined by claim 7, plus a conduit leading from the first mentioned overflow means to said container and through which the overflow fuel is returned to the container.

9. In liquid fuel burning apparatus of the class described, a burner pot comprising a perforated peripheral wall and a bottom wall, endless ridges dividing the bottom wall of the pot into an inner sump and sumps surrounding the inner sump, the bottoms of all sumps being in substantially the same horizontal plane, said ridges increasing in height from the inner sump toward the periphery of the pot, fuel conveying means for each sump, means individual to each conveying means forfeeding fuel therethrough, and an overflow means for the inner sump having an overflow edge below the plane of the top of the ridge defining said sump.

10. In liquid fuel burning apparatus of the class described, a burner pot having a perforated cylindrical peripheral wall and a circular bottom Wall, annular ridges dividing the bottom wall into a plurality of concentric sumps, the bottoms of all sumps being in substantially the same horizontal plane, said ridges increasing in height from the center toward the periphery of said bottom wall, a fuel supply conduit for each sump, means individual to each conduit for feeding fuel therethrough, and an overflow conduit for the central sump having its overflow edge below the plane of the top of the ridge defining said sump.

11. In liquid fuel burning apparatus of the class described, a burner pot including a cylindrical peripheral wall and a circular bottom wall, annular ridges dividing the bottom wall into a plurality of concentric sumps, the bottoms of all sumps being in substantially the same horizontal plane and the central sump constituting a pilot sump, said ridges becoming progressively higher from the center toward the periphery of said bottom wall, a fuel supply conduit for each sump entering the same through said bottom wall, means individual to each conduit for feeding fuel therethrough, and an overflow means for the pilot sump having an overflow edge below the plane of the top of the surrounding ridge.

12. In liquid fuel burning apparatus of the class described, a burner pot having barriers in the bottom thereof defining three sumps, said sumps being graduated in size to constitute of them a low-fire sump, an intermediate-fire sump and a high-fire sump, volumetric fuel feeding means for supplying fuel to the low-fire sump, mechanism for operating said feedin means continuously, volumetric fuel feeding means for supplying fuel to the other sumps, electrical mechanisms for operating the same, and an electrical control system comprising a source of electrical energy, thermostatic switch means including two circuit closers that function at different temperatures, and a circuit including said source and said switch means and characterized by two branches in each of which is connected one of said circuit closers and one of said electrical mechanisms.

13. In liquid fuel burning apparatus of the class described, a burner pot having barriers in the bottom thereof defining three sumps, said sumps being graduated in size to constitute of them a low-fire sump, an intermediate-fire sump and a high-fire sump, an overflow means for the low-fire sump having its overflovt edge below the plane of the top of the barrier defining said sump, and additional overflow means by way of which fuel from the other sumps is capable of overflowing into the low-fire sump, volumetric fuel feeding means for supplying fuel to the lowfire sump, mechanism for operating said feeding means continuously, volumetric fuel feeding means for supplying fuel to the other sumps, electrical mechanisms for operating the same, and an electrical control system comprising a source of electrical energy, thermostatic switch means including two circuit closers that function at different temperatures, and a circuit including said source and said switch means and characterized by two branches in each of which is connected one of said circuit closers and one of said electrical mechanisms.

14. In liquid fuel burning apparatus of the class described, a burner pot, annular ridges dividing the bottom of the put into a plurality of concentric sumps, the peripheral wall of the pot having air openings, a perforated pilot skirt surmounting the ridge that surrounds the central sump, an air tube rising centrally within the last mentioned sump and opening through the bottom wall of the pot, a perforated distributor head surmounting said tube, a liquid fuel container situated to one side and adjacent the bottom of the pot, means for supplying fuel thereto, means maintaining a substantially constant liquid level in the container, the container being so related to the burner pot that said liquid level is below the plane of the bottom of said sumps, a plurality of receptacles adjacent the container, one such receptacle for each sump, the same extending above the horizontal plane of the maximum liquid level of said sump a conduit through which fuel fiOWs by gravity from each receptacle to the corresponding sump, volumetric feeding means for transferring measured quantities of fuel from the container to each receptacle, operating mechanism for said feeding means, an overflow pipe having its receiving end in the central sump below the plane of the adjacent ridge and its delivery end opening into said container, and overflow means by way of which fuel from the other sumps overflows into the central sump.

15. In liquid fuel burning apparatus of the class described, the burner pot having barriers in the bottom thereof defining a plurality of sumps, a source of liquid fuel supply situated below the horizontal plane of the sumps, means for conveying fuel by gravity to each sump independently of the fuel conveying means of any other sump, fuel feeding means for elevating fuel from said source to said fuel conveying means, an overflow means for one of the sumps having its overflow edge below the plane of the top of the barrier defining said sump, fuel conducting means arranged to return fuel by gravity from said overflow means to said source, and additional overflow means by way of which fuel from another sump overflows into the last mentioned sump.

MARC RESEK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,490,572 Lijeske Apr. 15, 1924 1,502,045 McCarry July 22, 1924 1,693,054 Schein Nov. 27, 1928 1,944,593 Chadwick Jan. 23, 1934 2,302,329 Kirkpatrick Nov. 17, 1942 2,346,817 Breese et al. Apr. 18, 1944 2,366,706 Breese et a1. Jan. 9, 1945 2,404,853 Landon July 30, 1946

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