US2612885A - Heater for internal-combustion engines - Google Patents

Description

Oct. 7, 1952 w, COX 2,612,885

HEATER FOR INTERNAL-COMBUSTION ENGINES Filed Feb. 26, 1951 IN VEN TOR.

Tracy W C OX Patented Oct. 7, 1952 HEATER FOR INTERNAL- COMBUSTION ENGINES Tracy W. Cox, Salem, reg., assignor to Cox Enterprises, Inc., Salem, 0reg., a corporation of Oregon Application February 26, 1951, Serial No. 212,730

This invention relates to a heater for use with an-automobile engine or with anyliquid cooled in'ternal'combustion engineto warm and to circul-ate'the liquid enginecoolant preparatory to starting the engine in cold weather. 2

During periods of ,cold weather, so-called engine heaters increasingly are becoming popular for use with emergency vehicles, trucks, and farm equipment. Additionally, many motorists in cold weather regions are beginning to appreciate the advantages of these devices as an aid to cold weather starting. In essence, the conventional engine heater comprises a, hollow housing-memb'er having a waterproof heating element therein. A 'set of conduits are employed to connect this housing with the engine cooling jacket and with oneof the radiator hoses. In addition, an .electrio-cord is utilized to plug'the heater element into, an electric outlet of the type conventionally to be found in a garage or house lightingcircuit. As the'fheater element'begins to function, heat is transferred to the liquid engine coolant and a thermal circulation is setup through the cooling 'jacket and radiator. This heat and circulation "warms the engine tofacilitate starting and reduce engine-wearnormally incident to running a cold engine.

have become interested in the manufactureof'engine heaters and in the applications thereof "to-such emergency vehicles as police cars, am- 1 bulancesffiretrucks, doctors automobiles, repair vehi cle's'yand the like. Such interest has led to a discovery of several disadvantages inherent in the conventional heater, which disadvantages it is an object of the instant invention to eliminate.

' The prime disadvantages spring from the manner in which the conventional heater is joined to the" engine cooling jacket and/or to one of the water'hoses'. Thus, thenormal course of circulation through an automobile engine cooling jacket (after leaving the water pump) is from front to back along the lower or medial portion of the block,from back to front aldng'the upper portion of thefblock through the upper water hose, from top to bottom in the radiator, and back to the water pump through the lower water hose. Such ,a course, .it will be noted, is in accord with the natural thermal currents. in the jacket. When the conventional engine heater intake conduit is tapped into this course, either at the top of the block lore at one of the water hoses, however, it

gives birth to twin disadvantages.

, 'Thefirst'su-ch disadvantage is that the heater .whicl'i'isfconnected as above must circulate the liquid coolant through the radiator. This wastes 9 Claims. (Cl. 123-1425) a-large amount of heat and ener y. both by increasing materially the volume of liquid? to'be warmed and by requiring circulation through .the radiator structure, which structure expressly is designed to dissipate heat. Acoording'ly, one'object of my invention is to provide an engine heater which will by-passthe radiator and which need circulate the liquid coolant only through the jacket per se. One unexpected advantage flowing from the attainment of this object is that my circulates through the hot water heater in the passengercompartment; Thus,' my novel heater adds materially to the-passenger comfort.

The second disadvantage to'which-Irefer is that little, if any, of the warm liquid-reaches the lower portion of the engine block after leaving the engine heater. This produces an uneven heating of the block and is a result to be avoided. During the conduct of experimental tests, I have found that conventional heaters, after functioning for a period of time, will elevatethe temperature of the coolant in the top of the jacket, yet will leave the bottom of the jacket cold. This condition results from the fact that the inletconduit, from the jacket to the engine heater, conventionally is joined to one of the water hoses. These hoses draw their fluid supply from the upper portion of the jacket via the radiator or from the upper portion of the jacket per se (depending uponthe engine make and model).

Within the scope of my invention, it is a prime object toI change this conduitconnection and location. Accordingly, my engine-heater expressly is pointed toward the attainment of uniform heating of the engine block, such as has been hitherto unattainable. 1

To attain the above listed objectives. I prefer to incorporate a Venturi structure in the inlet connection to the heater of -my invention. ,The main flow of the venturi is derived from one of the water hoses or from the top of the jacket. The secondary flow, on the other hand, is. derived from the lower portion of the jacket. Thus; the

radiator hose 5, and a water pump a.

Fig. 1).

' 3 stat. Thus, the radiator, at all times, is closed to circulation and, in combination with my novel connection structure, no heat is wasted in warming the coolant in the radiator structure. This is in sharp contrast to the conventional engine heater.

These and other objects and advantages of my invention will be set forth in the following detailed description taken in conjunction with the accompanying drawing, wherein:

Fig. 1 is a side view of an automobile or other internal combustion engine showing my engine heater assembled and joined to the cooling jacket to heat the entire thereof in a manner uniformly engine block; v

Fig. 2 is a detail view showing the distant controlled valve means selectively for closing and opening the return conduit leading to the top rear portion of the engine jacket;

Fig. 3 is a section detail view, taken substantially on the line 3-3 of Fig. 1, showing the adjustable thermostat control means which is responsive to the temperature of the engine to actuate the heater element of my inventioniand Fig. 4 is an enlarged detail view, partially in section, indicating the structure of the vertical housing member, heater element, and venturi. I have chosen an L-type automobile engine I, with which to illustrate the principles of my invention. Such a choice, however, is not intended as a limitation to the scopeof my inventive concept since my engine heater is equally useful in conjunction with the valve-in-head and .V-type automobile engines, with diesel engines, marine engines, andwith a wide variety of liquid cooled internal combustion engines.

The engine illustrated comprises a radiator 2, a lower'radiator hose 3, an upper radiator hose 4, an engine thermostat housing 4a, a by-pass This structure, together with'the cooling jacket which extends throughout the engineblock, is conventional.

In Fig. 4, I have shown a cylindrical housing member 6 having a hollow chamber 1 open to a top outlet 8 and a bottom inlet 9. It is preferable, better to induce an eflicient thermal circulation in the liquid engine coolant, that the cylindrical housing member E'be mounted on the side of the engine I in a vertical position (see This is because the natural direction of thermal circulation is from bottom to top.v If desired, the vertical mounting may be accomplis'hed by means of a straphanger l0 and screws or rivets II.

In the lower portion of the housing member 6, the screw threads l2 accommodate a fitting l3 which carries the heater element l4. Electric current is supplied to the heater element I 4 through an electric cord so the liquid engine coolant within the hollow chamber- 1 will be warmed and a thermal circulation will be induced therein.

Referring more particularly to Figs. 1 and 3, an adjustable thermostat control means is shown mounted upon the enginel in-a housing l6. Withinthis housing IS, the electric cord 15 and the electric cord 11 having the plug-in connection It 'are joined across a microswitch [9. A bimetallic element spans the width of the housing I8 and is utilized to actuate themicroswitch l9. Adjustment of the actuation temperature of the bimetallic element 20 is accomplished by means of a threaded shaft 2| having a knurled knob 22 and a'pointer 23. The pointer 23 acts in conjunction with a dial scribed on the housing I8 (see Fig. 1) and indexed in degrees Fahrenheit. Thus, the bimetallic element 20 may be set to actuate the microswitch l9 at a temperature approximately five degrees lower than that temperature to which the automobile radiator thermostat/4a. is set.

I Returning to Fig. 4, I have shown a Y-fitting 24 having the leg thereof joined to the bottom inlet 9 and having the branches thereof joined to a first fluid conduit 25 and to a second fluid conduit 26, respectively. The second fluid conduit is shown provided with a terminal end 21. This end either may be a separate length of tubing, as shown, or may be an integral part of the conduit 26." In either event, the terminal end 2! protrudes into the first fluid conduit 25 adjacent the junction of the Y-iitting 24. This protrusion restricts the cross-sectional area of the conduit 25 adjacent the Y junction thereby to define a Venturi means. Due to this restricted cross section, the velocity of flow intothe .chamber lis increased and the static pressure-is decreased. This reduction instatic pressure enhances the flow of liquid coolant through the second fluid conduit 26 and'is of particular'importance to my inventive concept. One reason forthis importance is that prior art devices have failed toproduce sufficient coolant flow down through the restrictive passages provided around the cylinders and in the lower portion ofthe engine block. 7

After the liquid coolant "is warmed in the .chamberlby the heater element ll, thermal circulation causes the liquid to rise through the chamber, out the top outlet 8, and through the return conduit 29. This return conduit 29 is joined to the upper rear portion'of the cooling jacket'as shown in Fig. 1. If the engine l is located, in an automobile or truck having a hot water heater in the passenger-- compartment thereof, I prefer to employ a T-fitting 30 having a distant controlled valve 3| to join, the return conduit 29 to the engine block. This is for the reason that the hot water heater intake pipe 32 should be closed off while my engine heater is functioning else a great deal of heat enersy. will be wasted'in circulation through the hotwater heater structure. To this end, it 'will be noted that the valve 3| maydefine one of two-positions. In the first position (see Fig. 2), the return conduit 29 is open tothe top of thejacket and the car heater intake pipe 32 is closed. ,In the second position, the conduit 29 is closed and the pipe 32 is'open to allow the car heater to function normally. Actuation of the valve H is provided by means of a distant control knob 23 which may be mounted on the dash and which acts through apivot link 34. Thus, when the truck or automobile is to be driven, thedriver may control the position of the valve 3i from inside the cab or automobile passenger compartment. Furthermore, the valve 3| allows the coolant to be warmed prior to the time thehot water heater is used. Heat is thus made available to the passenger compartment as soon as the valve 3! is actuated.

Turning now to the operation of my engine heater. it will be noted that the second fluid conduit 26 is joined to the lower portion of theJ ngine cooling jacket, as by a connection 35, and:

from this portion of the jacket. During periods oflcold weather and while the engine'l is not'in use, the plug-in connection! is joined to an electric outlet of the'typeconventionally to be found in a garage or houselighting circuit.- In

addition, the knurled knob 22 is adjusted'to set the actuation temperature of the bimetallic'ele-j nient' and the microswitch l9 approximately five degrees below the actuation temperature of pump the coolant throughout the co-olingfjacket and through the various, conduits and" pipes. During a typical cyclic operation, the warmed coolant rises within the chamber "I, passes through the return conduit 29 and T- fitting so into the upper rear portion of the jacket. From this point the warmed liquid circulates forward and downward through the jacket. Since'the passages through'the upper portions of the jacket are relatively large, a major portion of the coolant will circulate along the top of the jacket, through the by-pass radiator hose 5 (because the thermostatic is closed), past the water pump ..5a, down the lower radiator hose 3, and through .the first fluid conduit 25into the Y-flttin'g-"i' i.

Within the Y-fitting 24, a Venturi effect is established and anarea of low static pressure is produced about the terminal end 21 of the second iiuid conduit 26. "sure enhances the flow through the secondfluid conduit 26 to drain a portion, of the coolant from This area of low static presth restricted passages in'the lower portion of the jacket. Thus, a continuous thermal circulation and flow takes place evenly throughout the entire engine cooling jacket. Such a continuous, uniform circulation achieves a uniform, preset temperature throughout the engine block in satisfaction of one of the prime objects of my invention.

Further in accord with the objects of my invention, it will be noted that the adjustable thermostat control means never allows the liquid coolant temperature to rise to a point where the radiator thermostat M. will be opened. Accordingly, the radiator 2, at all times, is closed to circulation. It is this'novel control means for the heater element I4, taken in conjunction with my novel connection structure, which eliminates entirely the waste of heat energy afforded by the conventional engine heater in warming the radiator contained portion of the coolant and in warming the radiator structure. As can be seen, the

provision of an engine heater which will by-pass the radiator and which need circulate the liquid coolant only through the cooling jacket per se is in direct service of the objects of my invention.

I claim:

1. A device for heating the liquid coolant car- -j ried in the cooling jacket of an engine, comprising a housing member having a hollow chamber communicating with the upper rear portion of said jacket and with a fluid conduit, respectively, said fluid conduit having means simultaneously *for conveying said liquid coolant both from the top and the bottom of said jacket to said chain'- her to promote uniform heating of the engine, and means carried by said chamber to induce circulation through the jacket and conduits.

'2 A device for heating the liquid coolant carried in the cooling jacket of an engine, comprising ahousing member having a hollow chamber communicating with the upper rearportion of said jacket and with a fluid conduit, respectively, said fluid conduit having means for conveying said liquid coolant from the bottom of said jacket to said chamber to promote uniform heating of the engine, and'h'eater means carried by said chamber to warm said liquid coolant and'induce circulation through the jacket and conduits, said heater means being actuated by control means responsive to the temperature of said engine. f

3. A'device for heating the liquid coolant-carried in the thermostat controlled cooling jacket of an engine, comprising a'vertical housingmem her having a hollow chamber communicating at the upperend thereof with the upper rear portion of said jacket and at-the lower end thereof with a fluid conduit, respectively, said fluidconduit having means simultaneously for conveying said liquid coolant both no'm the top and the bottom of said jacket to said chamber to promote uniform heating of the engine, and means carried by said-chamber to induce thermal circulation through the jacket and conduits, said latter means being actuated by control means responsive to the temperature of said engine and preset to a temperature less than the actuation-temperature of the thermostat control in said'cooling jackets" i a; A hollow chambered housing member 'having a heater means'for warming the liquid coolant which is carried in the cooling jacket of aninternal combustion engine, comprising a first fluid conduit joining the upper front portion of said jacket to said chamber and a secondfluid'conduitjoining the lower portion of said jacket "to said'first conduit, the'terminal end of said second conduit protruding into said first conduit to define therewith a Venturi means for lowering the static pressure at said terminal end to enhance fluid flow from the lower portion of said jacket. and a return fluid conduit joining said chamber to the upper rear portion of said jacket.

5. In combination with the cooling jacket of a liquid cooled internal combustion engine, a vertical housing member having a hollow chamber therein, heater means within said chamber for warming and for inducing thermal circulation of the liquid engine coolant, a first fluid conduit joining the upper front portion of said jacket to the bottom of said chamber and a second fluid conduit joining the lower portion of said jacket to said first conduit, the terminal end of said second conduit protruding into said first conduit to define therewith a Venturi means for lowering the static pressure at said terminal end, a return fluid conduit joining the top of said chamber tothe upper rear portion of said jacket, and control means responsive to the engine temperature to actuate said heater means.

6. In combination with the cooling jacket of a liquid cooled internal combustion engine, a vertical housing member having a hollow chamber therein open to a top outlet and a bottom inlet connection, heater means within said chamber for warming the liquid engine coolant and including thermal circulation therein, a Y-fitting having the leg thereof joined to said inlet and having the branches thereof joined to a first and to a second fluid conduit, respectively, said first conaeiaeq 7t duitbeing joined to the upper irontportion of said jacket and said second conduit being joined to the lower portion of said jacket, areturn fluid conduit joining-said outlet tothe upper rear portion of ,said jacket, and control means responsive to the engine-temperature to actuate said heater means, saidcontrol means including an adjustable thermostatmounted upon said engine.

-;7. In-combination with the cooling jacket of a liquid; cooled internal combustion engine, a verticalhousing member having a hollow chamber therein opento atop outlet and a bottom inlet connection, heater means within said chamber for; warming the liquid engine coolant and inducing thermal circulation-therein, a Y-fitting havingthe leg thereof joined to said inlet and having the branches thereof joined to a first and to a second fluid conduit, respectively, said first conduit being joined to the upper front portion of said jacket and said second conduit being looped about said engine and joined to the lower medial portion of said jacket, a return fluid conduit joining said outlet to the upper rear portion of said jacket, said return conduit carrying distant controlled valve means selectively for closing and opening the same to fluid flow, and control means responsive to the engine temperature to actuate said-heater means, said control means including an; adjustable thermostat mounted upon said engine.

8,-;In combination with the cooling jacket of a liquid cooled internal combustion engine, a verticalv housing member having a hollow chamber therein open to a top outlet and a bottom inlet connection, heater means within said chamber for warming-the liquid engine coolant and inducing thermal circulation therein, a Y-fitting having the, leg thereof joined to said inlet and having the branches thereof joined to a first and to a second fluid conduit, respectively, said first conduit being joined to the upper front portion of said jacket and said second conduit being joined to thelowerportion of said jacket, said second conduit including Venturi means for enhancing fluid flow from saidjacket lower portion, and'a return fluid conduit joining'said outlet to the upper rearportion of said jacket.

9. In combination with the thermostat and cooling jacket of a liquid cooled internal combustion-engine, a vertical cylindrical housing m' e 1 n1 ber mounted adjacent the side of said engine and having a hollow chamber therein open to a top outlet and a bottominlet connection, heater means within said chamber iorwarming the li s uid engine coolant and inducing thermal circu lation therein, a Y-fitting havingthe leg thereof joined to said inlet and having the branches thereof joined to a first and'to, a second fluid conduit, respectively, said first conduit being joinedto the upper front portion of said Jacket and said secondconduit being joined to the lower portion of said jacket, saidsecond conduit including yenturi means protruding into said first conduit-adjacent thejunction of said Y-fitti-ngfor enhancing fluid. flow Irom said jacket lower portionby lowering the static pressure at said junction ga return fluid conduit joining saido itlet to the upper rear portion of said jacket, and control means responsive to the engine temperature to actuate said heater means, said control means being presethto a temperature less than the actuation temperature of the engine thermostat. I .t

' TRACY w. 00x.

, REFERENCES orrnn The following references are of record in the file of this patent: t

UNITED STATES PATENTS Number] Name Y 7 Date 1,127,533 :Sloan Feb. 9, 191-5 1,357,598 Thompson Nov. 2, 1920 2,367,197 Ca1dwellf.. Jan.,16,'1

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