US2260536A - Automobile heater - Google Patents

Description

Patented Oct. 28, 1941 UNITED STATES 4PATENT OFFICE AUTOMOBILE HEATER Henry J. De N. McCollum, Evanston, Ill. Application October 10, A1938, Serial No. 234,137

(ci. zar-12.3) i

7 Claims.

The invention relates generally to heaters for motor vehicles and more particularly to a control for heaters of the class described that are provided with independent heat generators of the internal combustion type.

In instances Where internal combustion heaters are connected tothe intake manifold of an internal combustionengine in order to use the vacuum created in the intake manifold as a source of power to carry forward the process of combustion in the heater, the products of combustion are drawn into the intake manifold of the engine where they mix and commingle with the combustible mixtures which are provided by the engine carburetor for engine consumption.

In view of the fact that the products of comv bustion of such heaters contain inert and noncombustible gases which are of no value for recombustion purposes in the engine, the combustible mixture goingv to the engine is correspondingly diluted, and, while the amount of dilution is practically negligible at high engine speeds because of the proportionately large volume of the mixture used at such speeds, yet the degree of dilution becomes'critical when the engine is idling and the degrees of vacuum in the engine is very high.

'Such a dilution interferes with the correct operation of the engine vatidling speeds which can not be eliminated satisfactorily by resetting the idle adjustment of the carburetor.

Consequently, one of the objects of the invention is to provide a control which restricts the flow of burnt gases from the internal combustion heater into the intake manifold of an automobile engine when the engine -is idling. y

Another object of the invention is to provide a control for an internal combustion heater which reduces the flow of exhaust gases from the heater to the minimum barely necessary tor sustain heater combustion'when the engine is idling, and returns the iiow to a maximum when the engine speed is increased.

Another object of the invention is to provide a device ofthe class 'described wherein the flow of diluting burnt gases from the heater to the intake manifold of the engine is proportioned at low engine speeds to the now of combustible mixtures in the manifold to the engine.

Another object of the invention is to provide a control for internal combustion heaters exhausting into the intake manifold of an engine which may be used as a universal installation with all conventional internal combustion en.

. tion, other and further objects will become apparent from the drawing herein, .the descriptionL relating thereto, and the appended claims.

Referring now to the embodiment of the invention shown partly in side elevation and partly in enlarged vertical section in the single view of the accompanying drawing, the internal combustion heater is indicated generally by' the numeral I0, and reference may be had to my copending application, Serial No. 61,213, led` January 28, 1936, for the structural characteristics thereof, wherein, briefiy, air and fuel are drawn Ainto the carburetor I2, through the combustion chamber I4 Where the mixture is ignited to form hot gases which are drawn through the radiator unit I6 and vdischarged through the tube I8 into the intake manifold 20 of an automobile 'engine (not shown) by the vacuum devel the manifold zo. 1 @ed m Referring now to that portion of the drawing shown in vertical section,

a variable cut-off `valve 22 is disposed in the passageway 24 of the tube I 8, between the heater I0 and the intake manifold 20. The cut-off valve 22 comprises a fitting 26 having a bore 28 of approximately the samel size as the passageway 24 so that the normal ow of exhaust gases through the passageway 24 is unrestricted. A cylindrical plunger 30 provided with cpheical head moun e -in he fitting for movementy in a drical bore 34 that is normal to the bore 28.cy'.[il1ie plunger 30 is of` approximately the same size as the bore 28 whereby movement of the head portion 32 of the plunger into a position intercepting the bore 2li-serves as a variable cut-off valve -to control the flow of burnt gases through the pasgeway 24 from the *heater I0 to the manifold Movement `of the plunger controlled `in the embodiment illustrated by a flexible diaphragm 36 mounted in a suitable casing 38 and carrying an actuator rod 40 whichv isA portion 32 is reciprocally an 'in its capacity is" spring.

of a guide ange 50 struck from the casing 38.

The compartment 39 is open to atmosphere through an opening 52 and although it will be appreciated that there may be sulcient clearance between the guide flange 50 and the wall of the yrod 40 to admit air at atmospheric pressure into the compartmentl 39, the opening 52 is provided to avoid any danger of improper operation which might otherwise develop if the clearance between the flange 50 and the piston 40 were to become filled or restricted by dirt and other foreign substances.

The casing 38 is mounted relative to the fitting 26'by means of an arm 52, and the compartment 31 which is sealed to atmospheric pressure is connected in open communication with the intake manifold 20 through the tube 54 which leads to the intake manifold through an opening 56 located immediately below or upon the engine side of the throttle valve 58 of a conventional down-draft carburetor (not shown).

A compression coil spring 60 is provided upon the compartment 31 side of the casing to drive the rod 40 downwardly against the force of the vacuum upon the diaphragm so that the plunger 30 is held at a normally open position until such time as the vacuum present in the intake manifold is sufiicient to overcome the force of the Moreover, the spring is snugly mounted for operation in the cylindrical portion 59 of a bushing 6| which is threaded to the casing and is connected to tube 54 leading to a port 55 in the 'extension 65 to the wall of the carburetor. The cylindrical portion 59 is axially aligned with the rod 40 and the coils o1' the spring 60 cooperate with the reduced portion I4 of the rod to assist the guide flange in maintaining the rod 40in proper alignment.

Threaded collar 62 and flange 64 are provided for all connections so that in addition tothe device being readily assembled or dismantled for repairs, if upon occasion such are required, the

device may be installed conveniently as original equipment, or as an accessory for heaters already installed.

In operation the device described is arranged and adjusted to function in the following man- Iier: at.

The spring used in any pa cular device ,is selected to have the necessary tension which,

in relation to the area of the diaphragm 36 exposed to the vacuum in the intake manifold, will yield when the vacuum to which the diaphragm 36 is exposed approaches the degree which is present in the intake manifold at idling speeds, when the throttle valve is in dotted line position B. Under these conditions the upper surface of diaphragm 36 is subjected to high vacuum and iiexes upwardly to close valve 22 to a sufllcient 'degree to prevent ilow of exhaust gases from the heater therethrough in excess of the minimum v amount necessary to maintain-combustion in the heater. In this way dilution is minimized and lowered to a point which will not materially affect the idling opera-tion of the engine.

As soon, however, as the throttle valve is open slightly, to the dotted line position (A), the pressure in the port 55 rises rapidly to substantially atmospheric pressure. The degree of vacuum at the port 65 is thus critically responsive to the position of the throttle valve in the nearly closed v position of the latter. This fact will be apparent when it is considered that the port 55 is on the intake manifold side of the throttle valve when the valve is completely closed, but that as soon as the valve is slightly opened the port is on the side of the throttle valve opposite the intake manifold, and is thus subjected only partially to the high intake manifold vacuum. As a result of this construction, the diaphragm 36 is quickly responsive to the movement of the throttle valve to and from closed position, and the plunger valve 30 is moved toward closed position only when the :throttle valve is substantially completely closed.

Although a single embodiment of the invention has been shown and described herein, it will be apparent to those skilled in the art that various and further uses, modications and changes may be made without departing from the spirit and substance of the invention, the scope of which is commensurate with the appended claims.

What is claimed is:

1. In a heating system for use with an automotive vehicle having an internal combustion engine with an intake manifold on said engine, an internal combustion heater which exhausts the products of combustion thereof into the intake manifold of the internal combustion engine, a throttle valve between the engine carburetor and the intake manifold of the engine, va casing having an opening in one side thereof; a diaphragm disposed in said casing and dividing said casing into two compartments sealed from each other, resilient means urging said diaphragm in a direction towards the compartment having said opening therein, means connecting the other of said compartments to the intake manifold of an internal combustion engine upon the engine side of said throttle valve closely adjacent the point at which the edge of said valve lies when in closed than that developed at .approximately idling speeds.

2. In a heater -of the class described which exhausts the products of combustion thereof into the intake manifold of an internal combustion engine, the combination of a throttle valve between the engine carburetor and the intake manifold, a casing having an opening therein defining a bore, a diaphragm disposed in said casing normal to the axis of said bore and dividing said casing into two compartments sealed from each other, one of which has said opening therein,

resilient means urging saididiaphragm in a direction towards the compartment having said opening therein, means connecting the other of said compartments to the intake manifold of an internal combustion engine upon the engine side of the throttle valve thereof when the throttle valve is in closed position and eifectively upon the opposite side thereof when said throttle valve is in partlyopen position, an element extending through said bore connected to said diaphragm and reciprocated thereby, an exhaust passageway for said heater connected to the intake man- Y 2,260,536 ifold of the engine, and a plunger in said passageway moved to partly closed position by said ,ele-

ment when a lhigh degree .of vacuum .is created in said intake manifold and opened by said element under the influence of said 'resilient means when the degree of vacuum is other vthan a high degree. 1

3. In a heating system for use with an internal .combustion engine, an intake manifold 'on said engine, an internal combustion heater which exhausts the products of combustion thereof into the intake manifold of an internal combustion engine, the combination of a conduit having a `bore of predetermined cross sectional area through which lsaid-products'of combustion are conducted from the heater to said manifold, a

ycylinder transverse to and opening into' said bore, a piston reciprocally mounted in said cylinder having a headed portion movable to and from a position partially obstructing'said bore,

type throttle valve in said bore, said ,member having an opening on the intake manifold side of said throttle valve when the latter is in its closed position, and means connected to said `opening and responsive to pressure changes to cause 'said regulating valve to move toward closed position with increasing vacuum at said opening.

and means responsive to' the high degree oi lvacuum in said manifold normally present at approximately idling speeds of said enginevfor normally holding said piston open at engine speeds' other than idling and for moving said piston to a position partly obstructing said bore when said engine is idling.

4. In a heater of the class described which exhausts the products of combustion thereof into the intake manifoldof an internal combustion engine, the combination of a conduit having a bore of predetermined cross sectional area through which said products of combustion Aare conducted by vacuum from the heater to said manifold, a transverse cylinder opening into and ofthe same size as said bore, a piston reciprocally mounted in said cylinder having a spherical headed portion movable to and from a position partly obstructing said bore, and means responsive to a high degree of vacuum in said manifold for normally holding said piston in partly obstructing position and for moving said piston to non-obstructing position whenthe .degree Aoi? vacuum in said manifold is low.

5. For use with an automobile'having an internal combustion engine provided with a carburetor and intake manifold, the combination of an internal vcombustiontype heater, a discharge manifold ofsaid engine to conduct the gases of combustion from 'said heater to said intake manifold, a regulating valve in said conduit for controlling the new rate therethrou8h.,a member connecting the carburetor and intake manifoldv and having a throttlebore therein, a .butterfly 6. For use with an automobile having an in-f ternal combustion engine provided with a carburetorand intake manifold, the combination of internal combustion type heater, a discharge conduit connecting said heater to the intake manifold of said engine to conduct the gases of combustion from said heater to said intake manifold, a regulating valve in said conduit for controlling the flow rate therethrough, a member connecting the carburetor and intake manifold and having a throttle bore therein, a butterfly type throttle valve in' said bore, said member having an opening on the intake manifold side lof. said throttle valve when the latter is in its closed position, a casing connected to said opening ar diaphragm in said casing. an operative connection between said regulating valve in saidl diaphragm and resilient'means effective to move saidregulatingvalve to open position'whereby pressure decrease at said opening will cause' said regulating valve to move toward closed position.

'7.-In a heating system for use with an automotive vehicle having an. internal combustion engine, a carburetor, an intake manifold on said engine, .and a vthrottle valve between the carbu- A conduit connecting said heater to the intake conduit connecting. said heater vtothe intake retor and the intake manifold of the engine.' an internalcombustion heater which exhausts the products of combustion thereof into the intake manifold of the internal combustion engine, a

manifold of the engine, a valve in said conduit between said heater and said manifold for controlling the now of the products of vcombustion from the heater to the manifold, said valve' forming an obstruction capable of only pei-amy f` cutting oi! such flow, means holding said `valve in a normally open position, and means communicating with the intake manifold side of said throttle valve when the latter is closed and' xesponsive to the high degree of vacuum in said

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