US1927317A - Overflow tank for radiators - Google Patents

Description

Sept. 19, 1933. H. w. LLOYD ET AL OVERFLOW TANK FOR RADIATORS MWI JH V HHHH ld I I Patented ESepl. 1%, F333 UNITED STATES PATENT OFFICE OVERFLOW TANK FOR RADIATOBS tion of New York Application June 9, 1930.

Serial No. 460,071

15 Claims- (Cl. 123-174) This invention relates to cooling systems for internal combustion engines.

To carry away the heat of combustion, most internal combustion engines are provided with jackets surrounding the cylinders and combustion chambers for the flow therethrough of water or the cooling medium which absorbs the heat. In the case of motor vehicles and other conveyances, a radiator may be used and the same cooling liquid is then passed back and forth between the radiator and engine jacket, an engine driven pump generally being inserted in the system to continuously circulate the coolant in such conventional constructions. An overflow pipe is also provided to vent the system and prevent internal pressures by reason of expansion and contraction of the cooling liquid with temperature changes, and since the overflow liquid leaves the system, it becomes necessary to replenish the supply from time to time. While the necessity for replenishment is not ordinarily considered objectionable to the use of this type of cooling system on private pleasure automobiles when water is used as the coolant,'it does become an item for objection when the more expensive anti-freeze solutions are used, and more so when the engine is in long and hard service, as in the case of trucks and public conveyances.

To provide a system which will effectually eliminate loss of cooling fluid without material changes in the construction and operation of conventional systems by collecting and storing any overflow for subsequent return to the main system as it is needed to maintain the amount of liquid in the main system substantially constant and thus eliminate the necessity for frequent replenishment, is one of the primary objects of the present invention.

It is another object of the invention to provide an improved overflow system for temporary storage of excess liquid, which may be easily and quickly installed either as original equipment on new cars or as accessory equipment for existing cooling systems.

A further object is to provide an improved storage tank and an automatically controlled closure for the outlet therefrom leading back to the main circulatory system, so as to preclude the entrance of air and the formation of air pockets and steam in the engine jackets, which would reduce cooling efiiciency.

The invention aims also to impose restraint on the action of the closure member, as for example, by means of a dash pot or other friction device, so as to overcome any tendency of the closure member to vibrate or flutter, particularly when in closed position, because of either engine vibration, rough movement of the vehicle, liquid surge, or the like.

Various other objects and advantages of the invention will be apparent from the following detail specification, taken in connection with the accompanying drawing, which illustrates a preferred but not necessarily the only embodiment. In the drawing, Figure l is a side elevation of an engine and its cooling system, as employed on an automobile, with which there is associated the overflow system, forming the.pr esent subject matter. Figure 2 is a detail view of the overflow tank with parts thereof in section. Figure 3 is a transverse section taken on line 3-3 of Figure 2.

Referring to the drawing, the reference numeral 1 indicates an internal combustion engine of the multiple cylinder type as used on automobiles and which is located beneath a hood or bonnet 2 between the dash board 3 of the body, and a radiator 4. The radiator 4 is shown as of the conventional type having an intermediate cooling core, an upper header or intake tank, and a lower header or outlet tank. Behind the radiator is a fan 5 for drawing a current of air through the cooling core, the shaft of which carries a pulley to be driven by a belt 6 from the engine crank shaft. This fan shaft may also drive a pump 8 associated with cooling jacket of the engine 1 for forcing water or other cooling medium taken from the bottom of the radiator 4, through a tubular connection 9, between'the outlet header and intake side of the pump, through the engine jacket and then through the outlet therefrom, which is connected, as by means of a flexible hose or tube 10, with the inlet header of the radiator. The construction thus far described constitutes a conventional cooling system used on practically all motor vehicles and in which the engine drives a pump for circulating the cooling liquid back and forth between the engine and cooling radiator and also a fan to induce a draught or air current through the radiator, where the heat of combustion is dissipated to the air stream.

To take care of liquid expansion, an overflow pipe 13 customarily is located in the top tank and extends out through the wall thereof, and then down the side of the radiator to a point where the overflow will be discharged to the ground. In the present case it is proposed to connect the overflow 'pipe as by means of a short coupling 14, to one end of a length of tubing 15, which for mounted on the dash board 3 as by means of a convenience and appearance purposes, may extend down the side of the radiator and then rearwardly beside the usual chassis frame member and then upwardly, at a point adjacent the dash 3, where its opposite end may be connected to the -intake of an overflow tank or storage receptacle, indicated at 16.

For convenience and economy of manufacture, the overflow tank may consist of a length of seamless tubing, or it may be rolled from flat stock and united along its edges to form a tubular member, the ends of which may be closed by the cup shaped walls 1'7 and 18, respectively,'the annular flanges of the, end walls being suitably Joined and sealed, as for example, by means of soldering, welding, brazing, or the like. To facilitate installation, the overflow tank is preferably bracket, that shown in the drawing consisting of a U-shaped member 20 having out turned arcuate end flanges 21 for contact with the cylindrical wall of the tank 16, and being provided in each leg with an elongated'slot, through which extends a contractible ring or hoop 22, that terminates in lateral projections or ears, through which passes a stud 23, for drawing the ends together and contracting the ring to securely hold the tank in place.

The upper wall 17 carries an apertured nut 25 to receive an elbow fitting 26, having threaded therein a short tubular extension 27 for attachment as by means of the coupling 28 with the adjacent end of the overflow pipe 15. To vent the overflow tank, the top wall 1'? may also be provided with a small aperture, or it may be found more desirable to provide a reversely bent or a U-shaped piece of tubing, as at 30, which extends through the walland overthe side of the tank. In some cases it may be considered advisable to clip oil the customary overflow pipe 13, adjacent its upper end, for attachment with the pipe 15, and then use the clipped off part that normally extends down the side of the radiator as an extension of the U-shaped tube 30. This expedient is illustrated in Figure 1 where the piece of tubing, indicated by the reference numeral 31 and attached by the coupling part 32, represents that part of the normal overflow pipe 13, which was clipped off. In this way, if there should be any overflow from the tank 16, the discharge would be at a point below anything that could be harmed. It may. be stated incidentally, that if the storage tank is properly chosen for the particular system with which it is to be used, its capacity will be such that there will seldom if ever be any overflow thru the pipe or tube 30.

extends thru the aperture into threaded engagement with one end of a fitting 36, there being a gasket or washer 37 interposed between the end of the fitting and adjacent portion of the wall 18. to seal the connection against leakage. At its opposite end the fitting 36 is closed by a plug 38 and intermediate its ends there is provided a screw threaded opening to receive one end of the'pipe section 39, whose opposite end carries an elbow fitting 40. In the upstanding leg of the elbow fitting 40, is located a ball or check valve 41, held in place by the transverse pin 42, to prevent back fiow through the return line, as will be later referred to. A short length of tubing 43, provides for the attachment, by meanslof a Leaner-2" consist of a short length strap of U-section, bent to an inverted U-shape with inturned attachment feet for the connecting rivets. At its upper top center, the cage 51 carries a bearing disc orv washer 52, preferably formed of fibre and apertured for the projection therethrough, of a stem or shaft 53, to guide the same. As shown in the drawing, this shaft 53 has fixedly secured thereon a ball or float 54, which may consist of two semi-spherical metal cups secured together, and just below the ball the shaft carries a sleeve 55, having its lower end tapered or conical shaped for seating engagement with the upper side of the nut 35, to constitute a valve or closure for the outlet, leading from the tank. This valve or closure is normally held on its seat by gravity when the tank is empty and is automatically opened when the level of water stored in the tank reaches 'a point to float the ball 54 and thereby move the valve of! its seat. The shaft 53 is shown as projecting or extending into the fitting 36 and carrying at its lower end and below the connection with the pipe 39, a piston or movable wall 56, slidable in the bore of the fitting. This piston and the cooperating fitting wall provides a dash pot to check the movement of the fioat'54 to prevent its bobbing up and down due to sum!- The overflow unit is such that it may be easily.

and quickly installed with a minimum of labor and at low cost. Assuming that installation has been made and that the engine is ready for operation, the main cooling system is then filled lit ran

with water or whatever coolant it is desired to use, until the liquid level reaches the top of the overflow pipe 13. When the engine is started the pump immediatelycirculates the liquid through the main system and the heat of combustion absorbed in the engine jacket is dissipated in the,

radiator. At this time the sleeve or valve 55 is held on-its seat by gravity, thereby precluding the intake of airthrough the vent 30 and tubing 45 under influence ofpump suction. As the liq- .uid warms up it also expands, and such expan-.

sion forces part of the liquid into the overflow pipe 13 and tubing 15 into the top of the tank 16. Excess water is discharged from the main system so long as expansion occurs, but instead of being discharged to the ground and forever lost, it is'saved by being temporarily stored in the tank 16. So soon as the liquid level in the tank raises to a sufiicient height to float the ball 54, the valve 55 is lifted away from its seat,

such movement. being permitted to take place.

slowly, by reason of the frictional resistance of the dash pot. With the valve 55 open, the liquid is free to return thru the line 45 under pump suction, whenever contraction of liquid in the main system occurs andthe level or volume diminishes. It will be understood that the return ordinarily will not occur until after the operation of the engine has stopped and suflicient time elapsed to permit the liquid in the main system to become cool. Whenever the engine is again operated, the action of the pump will serve to draw in the water from the auxiliary circuit to the main circuit to replenish the supply until the liquid level in the auxiliary tank falls and permits the float 54 to descend and close the return line through the valve 55, to preclude entrance of air to the jacket from the vented tank and through the return line 45. When expansion of the liquid in the main circuit once more occurs, the action of the overflow repeats itself, and thus at no time does the supply of liquid completely leave the cooling system and, therefore, losses do not occur, and the necessity for frequent replenishment is eliminated.

The invention will be particularly useful in those cases where a solution such as a mixture of alcohol and water is employed as the coolant, inasmuch as any alcohol vapors which would tend to leave the main cooling system must first pass through the long overflow pipe 15 before reaching the air vent, and inasmuch as a certain amount of liquid will also be present in the line 15, the vapors will be condensed before reaching the air vent at the overflow tank. Furthermore, any liquid passing through the pipe 15 will give oflE some of its heat before reaching the tank, and as the result there will be but little vapor loss at the tank.

At such times, as when the engine is not in operation, there wilLbe a tendency for the water to flow from the main system into the overflow tank through the return line 45 to reach its own level, but this is effectually prevented by the provision of the check valve 41in the return line, whichiallows flow in one direction only.

We claim:

1. In a cooling system for internal combustion engines, a main circulatory system; a receptacle vented to atmosphere and adapted for temporarily storing excess cooling medium, a return line between said receptacle and the main circulatory system, a valve in the return line actuating means for the valve controlled by the body of cooling medium in said tank and adapted to close the valve when the receptacle is emptied and thereby prevent the entrance of air into the main circulatory system.

2. In a cooling system for internal combustion engines, a main circulatory system; a receptacle vented to atmosphere and adapted for temporarily storing excess cooling medium, a return line between said receptacle and the main circulatory level system and controlled means in the receptacle to close the return line against the entrance of air to the main system.

3. In a cooling system for internal combustion engines, a main circulatory system; a receptacle vented to atmosphere and adapted for temporarily storing excess cooling medium, a return line between said receptacle and the main circulatory system, means to prevent the passage of air through the return line when the receptacle is empty and other means associated with said return line to check the back flow of cooling medium therethru.

4. In a cooling system for internal combustion engines, a main circulatory system; a receptacle vented to atmosphere and adapted for temporarily storing excess cooling medium, a return line between said receptacle and the main circulatory system and a float controlled closure for the return line to close the line against the flowof air therethru when the cooling medium in said receptacle falls below a predetermined level.

5. In a cooling system for internal combustion engines, a main circulatory system; a receptacle vented to atmosphere and adapted for temporarily storing excess cooling medium, a return line between saidreceptacle and the main circulatory system and a float controlled closure for the return line to close the line against the flow of air therethru when the cooling medium in said receptacle falls below a predetermined level and means to retard the movement of said closure.

6. In an engine cooling system, an overflow tank for temporarily storing excess liquid for subsequent return to the system, a valve for opening and closing the liquid outlet therefrom and a float operatively connected with the valve to control the action of the valve in accordance with liquid level.

7. In an engine cooling system, an auxiliary tank for temporarily storing expansion liquid for subsequent return to the system, a valve for opening and closing the liquid outlet therefrom and float means associated with the tank to automatically control the valve.

8. In an engine cooling system, an auxiliary tank for temporarily storing expansion liquid for subsequent return to the system, a valve for opening and closing the liquid outlet therefrom, liquid level operated means associated with the valve to open and close the same, and other means to steady the action of said liquid level operated means.

9. In an engine cooling system, an auxiliary tank to temporarily storeexpansion liquid for subsequent return to the system, a return line leading from the tank, and a float controlled device associated with the return line to open and close the same.

10. In an engine cooling system, an auxiliary tank to temporarily store expansion liquid for subsequent return to the system, and a float con trolled device governing the return of liquid to the system together with means to damp the response of said device to changes in liquid level.

11. For use with an engine cooling system wherein an engine driven pump takes the cooling liquid from the radiator outlet and forces it thru the engine jacket to the radiator inlet, .125 means to receive excess liquid upon expansion of the liquid supply in the system for subsequent return to replenish the liquid supply, including a storage tank vented to atmosphere, an overflow connection between the system and said tank, and a return connection from the tank to the suction side of the pump, thru which liquid in the tank may be drawn back to the system under influence of the pump together with a liquid level controlled device in the tank to close the outlet therefrom after the overflow has been returned so as to preclude the'intake of air to the system and the formation of air pockets in the engine jacket.

12. An engine cooling system, including a main circuit in which a pump draws cooling liquid from the outlet side of a. radiator and forces it thru the engine jacket to the intake side of the radiator and an aiixiliary circuit in which a tank for the temporary storage of liquid expelled from the main circuit upon expansion, communicates with the main circuit by an overflow passageway and a return flow passageway, characterized by means to connect the return flow passageway on the suction side of the pump, other means to 1 vent the top of the storage tank, and a liquid level operated closure device in said tank for the return flow passageway to preclude air reaching the engine jacket thru said passageway.

13. In an engine cooling system, an overflow tank to temporarily store liquid expelled from the system upon expansion, for subsequent return to the system, said tank having an outlet, a

valve controlling the tank outlet, 2. float in theeratively connected with the valve to control the valve in accordance with liquid level, and a connection between the float and said piston to retard the action of the float.

15. In a cooling system for internal combustion engines, a main circulatory system for cool-- ing medium, a pump in said system for circulating the cooling medium, an over-flow tank to receive and temporarily store cooling medium expelled from the'main system, a suction line between said tank and the suction side of said pump for the return flow of cooling medium from the over-flow tank back to the main system, and means operated independently of suction to automatically close the return line against the passage of air when the tank is empty.

HERBERT W. LLOYD. J. R. HOLMES.

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