US2191177A - Automobile heater - Google Patents

Description

Feb. 20, 1940. H. J. DE N. MCCQLLUM 2,19l,'77 AUTOMOBILE HEATER Original Filed Jan. 28, 1936 NEN QON @N @NN QQN jlzvezai 01'? family Je/c COllm MQQM Patented Feb. 20, 1940 UNITED STATES AUTOMOBILE HEATER Henry J. De N. Mc

Gollum, Evanston, Ill.

Original application January 28, 1936, Serial No.

61,213. Divided and 1938, Serial No. 200,3

5 Claims.

The invention relates generally to automobile heaters and the present application is a division of a co-pending application, Serial No. 61,213 led January 28, 1936.

More particularly, the present invention relates to the operation and control of the independent heat generator illustrated and described in said copending application when the heater is so installed in an automobile as to employ the vac- LO uums created by internal combustion engine for a source of power to provide the fluid pressure differential needed to produce and move a stream of hot gases through the radiator of the generator.

In view of the fact that the degree of vacuum developed in the intake manifold of the internal combustion engine of an automobile approaches zero from time to time, depending upon the speed and the load to which the engine is subjected a under operating conditions, as when the automobile is being accelerated or driven up a hill, it is appreciated that now and then the vacuum developed in the intake manifold will fall below the degree necessary to maintain the factors of com- 35 bustion required for a continuous operation of the heat generator. Consequently, it is necessary to provide for a reignition of the combustible mixture in the generatorkso that the operation of a heater may be resumed when the vacuum B0 factors are again favorable. Moreover, other contingencies arise when the combustion has ceased for a while and these have to be coordinated with the rei'gntion to return the heater to proper and full operation.

B `One of the objects of the invention is to provide for the reignition of the extinguished flament an internal combustion heater when the factors are again favorable therefor and to coordinate therewith the other functions necessary to return l0 the heater to full operation.

Another object of the invention is to provide a liquid fuel burning heater with improved means for maintaining a flame and reestablishing the flame, should the flame be accidentally extinguished.

Another object of the invention is to provide an improved means for reigniting and returning the heater to full operation automatically with- 50 out attention from the operator when the factors preventing the operation of the heater are removed either after a short or a long delay.

Another object of the invention is to provide a heater and control therefor of the'class described, which is relatively simple in construction and 1this application April 6,

may be economically manufactured, installed,

operated and maintained.

These being among the objects of the invention, other and further objects will become apparent from the drawing herein, the description relating thereto and the appended claims.

Referring now to the embodiment of the invention illustratedI diagrammatically in the single view of the accompanying drawing, the heater construction, which is more particularly de-A scribed in said copending application, comprises generally, a carbureting device I 0 which supplies to the heater I2, as indicated by the arrow I4, several combustible mixtures of diierent degrees of richness to take care of the various heater requirements encountered under starting and running conditions.

The combustible mixture supplied to the heater is fed into the combustion chamber I6 in a suitable manner and the mixture is ignited by an electrical heating element I8 located in a recess 20 in the side .of the chamber. A refractory ceramic plug 22 is disposed at the outlet of the combustion chamber to maintain an ignition heat since it acquires a su'iciently high temperature for such purpose by being directly exposed to the flame during the normal operation of the heater.

From the combustion chamber, the hot gases pass through a radiator 24 comprising a circuitous tube 26 to which heat radiating fins 28 are thermally connected. Over these fins air is circulated by a motor 30 and fan 32 whereby heat is transferred from the hot gases of combustion to the passenger compartment of the automobile for the comfort of the passengers.

The outlet .of the circuitous tube '26 is connected to the intake manifold of aninternal combustion engine and in this way the fluid pressure differential necessary for the operation of the heater is supplied whereby the combustible mixture is drawn from the carbureting device I0 into the combustion chamber I 6 where it is ignited and the hot gases of combustion thereby created are then drawn through the radiator 24 in heat transfer relationship. Finally, the gases are disposed of in the intake manifold where any excess of fuel not already burnt or utilized may be employed in the operation of the engine itself.

'Referring now to the operation and control of the embodiment illustrated in the accompanying drawing, it will be appreciated as already mentioned that upon occasion the intake manifold vacuum may be so small that the rate of flow of combustible mixture into the combustion chamber I6 will not be suiciently rapid to support the flame. Itwill, therefore, be necessary, upon occasion, to reignite the name. For this purpose, an automatic means is provided for reconnecting the igniter I8 to the source of current during the time that the vacuum is too low for the continued operation of the heater. particular embodiment illustrated employs' a vacuum control switch which is automatically closed upon the lowering of the intake manifold beyond a predetermined' value, and although shown in use with a high resistance heating element such as the igniter I8 illustrated, the switch is also useable in connection with a spark plug type of igniter.

In the embodiment illustrated, the switch is controlled by a ilexible diaphragm 821 mounted in a suitable casing 84 and carrying a contact point 86 which is cooperable with a contact point 88 carried at the end of an adjustable screw 90. The contact 86 is connected by a flexible conductor 92 in a binding post 94, insulated from the v casing 84. The right hand side of the casing 84,

as viewed in the drawing, is connected by pipe 96 with a chamber 98. The chambery 98 communicates with a tube |00 through a restricted passageway I02and with the atmosphere through a similar restricted passageway |04. The left hand side of the casing 84 communicates with a`V chamber |06 through a connecting tube |08. The chamber |06 communicates with the intake manifoldthrough a restricted passageway IIO and communicates with a combustion chamber I6 of the heater through a restricted passageway II4. The passageway II4 is of slightly greater diameter than the passageway |04.

The igniter element I8 has one end connected to the binding post 94 and itsother end connected to the battery II6 through a manually operated switch II8. The adjustable contact 88 is connected by a conductor |20 to the battery II6, completing the igniter circuit. The fan motor 30 has one terminal thereof connected with the conductor |20 and the other terminal thereof connected to a thermostat switch |24. The main switch II8, when closed, is adapted to complete the circuit to the fan motor 30 (providing the thermostatic switch I 24 is closed) through a conductor |26. Upon closing the switch II8, the

. circuit through the igniter I8 will be completed,

since the switch contacts 86 and 88 operated by the diaphragm 82 will normally be closed. When, however, combustion commences in the combustion chamber I6, the switch contacts 86 and 88 willbe separated because' of the differential in pressure upon the opposite sides of the diaphragm resulting from the starting of a flame in the combustion chamber.

Prior to the ignition of the flame, the degree of vacuum present upon opposite sides lof the diaphragm 82 will diier because of the diierence in the diameters of the passageways |04 and II4. Since the passageway |04 is the smaller, the degreeV of vacuum produced in the chamber 98 (and hence in the right handside of the casing 84) will be higher than the vacuum in the chamber |06, because the tendency to high vacuum in the chamber |06 will be more completely relieved by virtue of the factthat the passageway II4 is' `of relatively large diameter. As a result, the diaphragm 82 will be flexed to the right, closing Vthe contacts 86 and 88.

The'

owing through the passageway I I4 are expanded by virtue of their high temperature, the rate of owof gas (by weight) through the passageway II4 will be less than the rate of flow through the passageway |04. As a result, a higher vacuum will be built up and maintained in the chamber |06 than in the chamber 98. The diaphragm 82 will, under these circumstances, be ilexed to the left, separating the contacts 86 and 88 and opening the circuit to the igniter I8. Since the igniter I8 draws a relatively large current, it is desirable that it be connected to the battery for as short an interval as is necessary to ignite the iiame.

Should the ame in the combustion chamber become extinguished, the gases drawn through the passageway I I4 will be at a low temperature, and as a result the rate of flow of gases (by weight) through the passageway I|4 will exceed the rate of flow through the passageway |04, and as a result, the vacuum within the chamber 98 will become greater than the vacuum in the chamber |06, causing the diaphragm 82 again to ilex to the right and complete the circuit to the igniter.

If desired, the right hand side of the diaphragm 82 may be opened to the atmosphere and a spring utilized to press the center portion of the diaphragm to the right and to maintainthe contacts 86 and 88 closed. In this instance, the spring will apply just suiicient force to maintain the contacts closed when cold air is flowing through the passageway II4, but will not apply sufficient force to hold these contacts closed when the vacuum in the chamber |06 is increased upon the ignition of the iiame in the combustion chamber.

Consequently, the embodiment shown and described provides a physical embodiment accomplishing the' express and implied objectsof the invention and although a single embodiment has been 'shown and described, it will be apparent to those skilled in the art that various and furthen uses, modifications and changes may be made without departing from the spirit and substance oi the invention, the scope of which is commensurate with the appended claims.

What is claimed is:

1. In a heater for an automotive vehicle having an internal combustion engine, the combination of a combustion chamber, means to supply a mixture of liquid fuel and air to said combustion chamber, 'a radiator for receiving the products oi combustion from said chamber, a connection from said radiator to the intake manifold of the automobile engine `to draw the charge of combustible mixture into said combustion chamber and the products of combustion through said radiator, an electrically operated igniter in said combustion chamber, a source of electricity for said igniter, and means for connecting said igniter to said source whenever the degree of vacuum in said intake manifold fails below the minimum required to cause flow of the combustible mixture into said chamber ata sufficiently rapid rate' to support a flame therein, and to disconnect said igniter from said source when the degree of vacuum exceeds said minimum value, said last named means lcomprising a casing, a movable wall separating said casing into two compartments, a switch operated. bysaid movable wall, a rst chamber connected to one of said I compartments and having a port communicating with the intake manifold and a port communieating with the atmosphere, and a second chamber connected to the other of said compartments and having a port communicating with said com- 1 bustion chamber and a port communicating with the intake manifold.

2. In a heater for an automotive Vehicle having an internal combustion engine, the combination of a combustion chamber, means to supply a mixture of fuel and air to said combustion chamber, a radiator for receiving the products of combustion from said chamber, a connection-from said radiator to the intake manifold of the automobile engine to draw the charge of combustible mixture into said combustion chamber and the products of combustion throughsaid radiator, an electrically operated igniter in said combustion chamber, a source of electricity for said igniter, and means for connecting said igniter to said source whenever the degree of vacuum in said intake manifold falls below the minimum required to cause flow of the combustible mixture into said chamber at a suiilciently rapid rate to support a flame thereinfand to disconnect said igniter from said source when the degree of vacuum exceeds said minimum value, said last named means comprising a casing, a movable wall separating said casing into two compartments, a switch operated by said movable wall, a chamber connected to one of said compartments and having a port communicating with the intake manifold and a port communicating with the atmosp-here, a second chamber connected to the other of said compartments and having a. port communicating with saidcombustion chamber and a port communicating with the intake manifold, said combustion chamber connecting port being slightly larger than the port communicating with the atmosphere, whereby the vacuum in said lrst chamber will be greater than the vacuum in said second chamber except when gases flowing through said combustion chamber connecting port are heated to a temperature resultant from normal combustion in the combustion chamber, said means comprising a pressure operated switch, and means responsive to the temperature of the gases leaving said combustion chamber to control the operation of said switch. l

3. In a heater for an automotive vehicle hav ing a passenger compartment and an internal combustion engine, the combination of a combustion chamber, means to supply a mixture of liquid fuel and air to said combustion chamber, a radiator for receiving the products of combustion from said chamber, a connection from said radiator to the intake manifold of the automobile engine to draw the charge of combustible mixture into said combustion chamber and the products of combustion through said radiator, an electrically operated igniter in said combustion chamber, a source of electricity for said igniter, and means for connecting said igniter to said source whenever the degree of vacuum in said intake manifold falls below the minimum required to cause ow of the combustible mixture into said chamber at a suiliciently rapid rate to support a. flame therein, and to disconnect said igniter from said source when the` degree oi vacuum exceeds said minimum value, said last named means being critically responsive to the heat expansion of the hot gases of combustion in said combustion chamber as distinguished from unburnt combustible mixtures supplied thereto.

4. In an internal combustion heater for use with an internal combustion engine having an intake manifold, a combustion chamber, means to supply a combustible mixture of liquid fuel and air to the combustion chamber, means to connect the combustion chamber to the intake manifold, an electrically operated igniter in the combustion chamber to ignite the combustible mixture, a source of electricity for the igniter, and means for connecting the igniter to said source whenever the suction in the intake manifold falls below a certain required minimum and to disconnect the igniter from said source when said mixture becomes ignited, the last named means comprising a casing, a movable wall separating the casing into two compartments, a switch operated by the movable wall, said switch adapted to close a circuit between the igniter and said source, a chamber connected to one of said compartments and having a port communicating with the intake manifold and a port communicating with the atmosphere, and a second chamber connected to the other of said compartments and having a port communicating with the combustion chamber and another port communicating with the intake manifold.

5. In a heater of the class described which depends for its operation upon the suction in the intake manifold of an internal combustionengine, a combustion chamber, means to connect the combustion chamber to the intake manifold. means to supply a combustible fuel and air mixture to the combustion chamber under the influence of said suction, an igniter in the combustion chamber to ignite the combustible mixture passing therethrough, a source of electrical current supply, a switch adapted to complete a circuit between the igniter and said source to energize the igniter, and automatic control means to open and close said switch, said control means comprising a chamber vented to the combustion chamber and to the intake manifold, and a pressure sensitive element movable to open and close said switch under the influence of gas pressure in said chamber.

HENRY J. DE N. MCCOLLUM.

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