US2035611A - Cooling system for motor vehicles - Google Patents

Description

ATTORNEY W. F. LEE

COOLING SYSTEM FOR MOTOR VEHICLES Filed July 9, 1935 March 31, 1936.

Patented Mar. 31, 1936 UNITED STATES- TENT O F F [@Ev This invention relates to cooling systems for motor vehicles. and more particularly to. cooling systems wherein a pump is employed for drawing cooling liquid from the. bottom of a radiator, forcing it through the water jackets and back to thetop of the radiator- The primary object of the invention isv to avoid the loss of cooling liquid from the cooling. system through. evaporation, sothat a low. boiling. sub.- stance such as alcohol may be added. in. cold weather to. prevent freezing and may be. utilized without liability of being substantially depleted through vaporization.

In the conventional cooling. system of the type with which this invention has. to do provision is ordinarily made. of an. open. overflow pipe. Any low boiling constituent of the cooling. liquid, such as aIcohol',. tends tovaporize. readily and has a free passage to the, atmosphere through the overflow pipe so that. the percentage of alcohol in the cooling, liquid is. progressively depleted This occurs even though. the operation normal and the average temperature of the liquid leaving the water jackets. is below the boiling point oi alcohol; the cause. being, probably, that. vapor bubbles are formed in the portion of the liquid which comes in contact with the cylinder metal which are. not re-condensed by the heated liquid passing to the radiator.. The result is that the operator. cannot be sure of the strength of the solutionin. the cooling systemand hence does not know what temperature the cooling liquid can safely withstand without freezing.

In. accordance with the present invention provision ismade. of an aspirating device; having its intake end located in the top of the radiator above the normal liquidlevel and having its opposite or' discharge end disposed in a location to have the cooled liquid flowing from the radiator exert a' suction eiiect' to cause vapor to be sucked out of thetop of the radiator and inj'ected into the cooled liquid for recond'ensation therein.

In orderto avoid the sucking of air through the aspirating device, and also to avoid the escape of vapor when the hot motor is stopped, an autnmatic valve is applied to the upper' or intake end of' the overflow pipe. This valve is so arrangedthat it acts at all times to" prevent air from entering the radiator. It also acts normally to. prevent the escape of liquid or vapor from the radiator but is yieldable in response to a sufficient pressurewithin the radiator to permit the escape of liquid and vapor under abnormal conditi'ons.

In practice I have found that. it is. practicable to. use the. device described without making any planned provision for the admission. of. air to the radiator... Should a radiator of light, construction. be employed however, it. may be desirable. as a. safety measure topermit air toenter. under some conditions so as to. avoid the possible collapsing. of. the radiator by atmospheric pressure when a partial vacuum occurs in. the radiator exceeding, a safe limit- In accordance with a further feature. of the invention, therefore, pro.- vision is made in the aspirating line of an emergency air. inlet valve, the valve. being. so located that it normally excludes atmospheric air altogether but is capable of yielding, and admitting air before a dangerous pressure difference occurs; Such a. condition may occur when. the liquid in a cooling system employing a radiator of; light construction cools, and contracts as an incident of'cooling.

It is a further feature that the. aspirating device and the overflow valve are so constructed that they may be applied as accessories to existing, cooling systems of. conventional design. Other objects and advantages will hereinafter appear.

In the drawing forming part of this specification Fig. 1 is a fragmentary, sectional side elevation partly broken away, illustrating. features of a preferred embodiment of the invention;

Fig. 2 is a view in sectional elevation taken upon the line 2.2 of Fig. 1, looking in the direction of the arrows;

Fig; 3 is a sectional, detail view of the valve 1 mechanism mounted upon the upper end of the Fig. 4 is a sectional view taken on the line. 4'4 ofFlg; 3 looking in the direction of the arrows;

Fig. 5 is" a detail, sectional view showing the air admission valve, and

Fig; 6 is a fragmentary, sectional view; taken on the line 6-6 of Fig. 1,. looking in the direction of the arrows.

In Fig. 1 disclosure is made of a vehicle motor l' of conventional construction comprising the usual water jackets 2* and discharge manifold 3. A flexible discharge hose t connects the manifold 3 with the top ofa radiator 5 located at the front of the vehicle. The radiator may be of conventional' construction 50' that the water flows downward through it, is cooled, and is drawn off' through a flexible hose 6 and a pipe I by a force feed pump 8 of any approved construction. It is desirable, however. that the pump be of a type which is capable of passing vapor or air. The pump delivers the cooling liquid to a manifold 53 which distributes it to the water jackets of the several cylinders.

For the purpose of sucking vapor out of the top of the radiator and discharging it into the liquid stream flowing through the hose 6 and the pipe 'I, provision is made of a tube It having its upper end disposed in the upper part of the radiator and having an open mouth located near the top of the radiator. The tube It] passes through the rear wall of the top portion of the radiator and is connected through a T-fitting I I with a tube l2 which extends downward into proximity to the hose 6. A nozzle I3 is secured to the tube I2 in any suitable manner as by soldering.

The nozzle comprises a mouthpiece is which flares gradually to form a collar [5. The upper face of the collar l5 forms an abrupt shoulder and is adapted to engage the inner wall of the hose 6, the construction being such that the nozzle may be forced through an opening formed in the hose of less diameter thanthe shoulder so that the hose material will spring inward and overlie the shoulder after the shoulder has passed through the opening. The upper end of the nozzle has a threaded stem portion IE to which a clamping nut I! may be applied for clamping the hose material firmly between the shoulder 15 and the nut to form a leak-proof joint.

The nozzle l3 may have its mouthpiece M designed in any suitable manner to provide the degree of suction desired in accordance with the characteristics of the cooling system to which it is applied. For some installations adequate suction will be secured by terminating the mouth of the nozzle in a plane at right angles to the nozzle bore. Should greater suction be desired the nozzle may be beveled at the end so thatits lower face inclines upward and rearward, or the lower end may even be turned in the direction of liquid flow, the securement of the best arrangement being a matter of design. It has been found in practicethat it is a simple matter to secure a sufficient suction to keep the tubes l2 and I0 normally free of liquid, and to draw the'vapor out of the top of the radiator'and mixit with the cooled liquid passing through the hose 5.

It is not desired to circulate air uselessly through the cooling system, nor is it desirable to permit a large quantity of air to be present in the system. Neither should the vapors be permitted to escape when the engine is stopped and the hot motor is'left standing. Provision is accordingly made of a valve l8 which is adapted to be applied to the upper end of the conventional overflow pipe l9. One form of valve structure suitable for excluding air and for permitting escape of liquid and vapor only under abnormal conditions. is illustrated in Fig. 3. This structure comprises a bushing 20 having an internal flange 2| at its upper end. The bushing 20 is adapted to fit onto the upper end of the overflow pipe I9 with its flange resting upon said pipe. The bushing 20 carries a valve housing or cylinder 22 which has an internal flange 23 at its upper end. The flange 23 has a beveled or conical inner face which forms a valve seat. A valve body 24 is slidably mounted in the housing 22 and is provided with a conical upper end which normally seats against the flange 23, being held thereagainst by a coil spring 25 which is interposed between the bushing 20 and the valve body 24.

The valve body is provided with shallow longitudinal grooves 26b to permit liquid and vapor to pass when the pressure in the radiator is sufficient to force the valve body 24 away from its seat. The valve assembly is secured to the overflow pipe by a set screw 25a threaded through the bushing 20.

As has been pointed out, it may be dangerous in some structures to positively exclude air under all conditions,particularly when the cooling liquid is contracting. It is for this reason that the T-fltting H is provided between the tubes l8 and 12. The T-fltting may be secured to the tubes 10 and E2. in any suitable manner as by soldering. It is provided with a'transverse bore 26 which terminates at one end in an internal flange 21. The

flange 21 is beveled and forms a seat for a valve body 28 mounted in the bore 26. A spring 29 bears against the valve body and against a plug 3ilthreaded into one end of the bore 26, and holds the valve body 28 normally against its seat. The valve bodyis provided with shallow longitudinal groovesor'channels 3! to permit air to pass when thevalve 28 is forced away from its seat by the pressure of the atmosphere. The spring 29 is made of such stiffness that it will open before a dangerous degree of vacuum occurs in the cooling system. The valve 28 Will rarely open in practice, however, because there will generally be a small quantity of air in the top of the radiator which will tend to prevent any very high vacuum being realized, and also because the existence of sub-atmospheric pressure in the radiator. will tend to produce some evaporation of the coolingliquid.

, The top of the tube I0 is desirably located above the level of the valve l8 on the overflow pipe and as near to'thetop of the radiator as is feasible, so as .to assure the passage of vapor rather than liquidthrough the tubes I0 and I2.

' The described structure can be manufactured and applied economically either as an accessory or. as a standard part of a motor vehicle cooling system. It has been found to be very eflicient in use and to be so effective in conserving alcohol that the quantity lost from the system in an entire winter season is negligible.

While I have illustrated and described in detail certain'preferred forms of my invention, it is .to beunderstood that changes. may be made therein and the inventionembodied in other structures. I do not. therefore, desire to limit myself to the specific constructions illustrated, but intend to cover my invention broadly in whatever form its principle may be utilized.

I claim:

1. In a motor vehicle, a circulatory cooling system comprising water jackets, a radiator, a

pump for circulating cooling liquid, a suction device for withdrawing vapor from the top of the radiator and injecting it into a portion of the cooled liquid which has been cooled bypassage through the radiator, an. overflow pipe separate and distinct from the suction device having its inlet in the top of the radiator, and a valve in the upper end of the overflow pipe preventing ingress of air and normally preventing escape of vapor but automatically operable to permit the escape of vapor when abnormal pressure occurs in the system.

2. In a motor vehicle, a circulatory cooling system comprising water jackets, a radiator, a pump for circulating cooling liquid, an aspirating device, operated by the flowing cooled liquid, for withdrawing vapor from the top of the radiator and injecting it into the cooled liquid, an overflow pipe separate and distinct from the aspirating device having its inlet in the top of the radiator, and a valve in the upper end of the overflow pipe preventing ingress of air and normally preventing escape of vapor but automatically operable to permit the escape of vapor when abnormal pressure occurs in the system.

3. In a motor vehicle, a circulatory cooling system comprising water jackets, a radiator, a pump for circulating cooling liquid, and an aspirating device, operated by the flowing cooled liquid, for

' withdrawing vapor from the top of the radiator and injecting itinto the cooled liquid, an overflow pipe, said overflow pipe and aspirating device being separate and distinct from one another from the level of the top of the radiator downward and both communicating directly with the top of the radiator and means associated with the overflow pipe for normally sealing the system against escape of liquid or vapor, but yieldable in response to abnormal pressure, to permit such escape under abnormal conditions.

4. In a motor vehicle, a circulatory cooling system comprising water jackets, a radiator, a pump for circulating cooling liquid, and an aspirating device, operated by the flowing cooled liquid, for withdrawing vapor from the top of the radiator and injecting it into the cooled liquid, an overflow pipe distinct from the aspirating device and having its inlet in the top of the radiator, a valve preventing admission of air through the overflow pipe and normally sealing the system against escape of liquid or vapor through the overflow pipe, but yieldable in response to abnormal pressure to permit such escape under abnormal conditions, and an emergency pressure responsive means for admitting air to the system upon the occurrence of subatmospheric pressure therein at a pressure which the system can withstand without damage.

5. In a motor vehicle, a circulatory cooling system comprising water jackets, a radiator, a pump for circulating cooling liquid, means for returning the liquid from the radiator to the pump comprising a section of flexible hose, a suction device for withdrawing vapor from the top of the radiator and injecting it into the liquid flowing in the hose comprising tubing running from the top of the radiator to the hose, a nozzle connected to the tubing and formed to provide an abutment adapted to be forced through an opening in the wall of the hose from the exterior thereof, and means for clamping the nozzle abutment in sealed engagement with the hose wall, an overflow pipe distinct from the suction device and having its inlet in the top of the radiator, and a valve adapted to be applied as a fitting to the top of the overflow pipe for normally sealing the pipe against egress of the cooling fluid.

WILLIAM F. LEE.

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