Patent Publication Number: US-7213619-B2

Title: Methods for replacing engine system cooling fluids with a continuous flow

Description:
BACKGROUND OF THE INVENTION 
     1. Incorporation by Reference 
     Applicant(s) hereby incorporate herein by reference, any and all U.S. patents and U.S. patent applications cited or referred to in this application. 
     2. Field of the Invention 
     This invention relates generally to methods for replacement of fluids in systems and more particularly the replacement of coolant fluids in an automotive type engine cooling system. 
     3. Description of Related Art 
     The following art defines the present state of this field: 
     Babish et al., U.S. Pat. No. 4,109,703 describes an internal combustion engine cooling system that is flushed by: (a) providing a controlled pressurized flow of flushing liquid and entrained gas bubbles, (b) and passing said flow alternately through (i) the radiator in a reverse direction, (ii) the engine coolant passages in a reverse direction, (iii) the radiator in a forward direction, (iv) the engine coolant passages in a forward direction. 
     Cassia, U.S. Pat. No. 5,103,878 describes a flush cap for a vehicle cooling system wherein the flush cap has an inlet through which fresh water enters and an outlet through which dirty coolant leaves. The method employs the flush cap to flush the cooling system of the vehicle. The radiator cap can be adapted to drain a radiator using a hose attached to the outlet of the cap. 
     Akazawa, U.S. Pat. No. 5,615,716 describes an engine coolant changing apparatus for changing an engine coolant such as LLC (long-life coolant) in an engine coolant path containing a radiator, comprising coolant storing means possessing a pressure action port and a liquid inlet and outlet, detaching mechanism to be attached or detached to or from a filler port of a radiator, communicating device for communicating between the liquid inlet and outlet and the detaching device, and pressure action device for applying a negative pressure to the pressure action port to overheat the coolant to a low temperature by driving an engine when discharging the coolant from an engine coolant system, and applying a positive pressure to the pressure action port when feeding a fresh liquid, so that the coolant can be changed promptly in a short time, without requiring manipulation of radiator drain cock or jack-up of the vehicle. 
     Turcotte et al., U.S. Pat. No. 5,649,574 describes a removal and refill apparatus for use in removing and/or refilling coolant in an automotive cooling system. The automotive cooling system typically includes a radiator, overflow bottle, engine, water pump, and heater core elements. A method for utilizing the coolant removal and refill apparatus utilizing vacuum and pressure is described for use with the removal and refill apparatus. 
     Fletcher, Jr. et al., U.S. Pat. No. 5,845,684 describes a clean and easy-to-use, portable upright apparatus, and a method for its use, which can be used to flush and fill the radiator and coolant systems of motorized vehicles in approximately 15 minutes, the apparatus comprising a self-priming pump, a waste collection tank, a tank for holding new or recycled coolant, a filter assembly, and a wheeled support structure for conveniently and efficiently housing the pump, tanks, filter assembly, and the several hoses needed to perform the flush and fill procedure. Applications may include, but are not limited to, flushing coolant from automobile radiators and refilling them with new or recycled coolant. 
     Clark, II, U.S. Pat. No. 6,073,666 describes a portable automated fluid collecting and dispensing unit (10) for the collection of used fluid and for the delivery of new fluid to a fluid utilizing device, such as motor (44). The device (10) includes a tank arrangement (12) having a used fluid tank (14) for collecting and storing used fluid and a new fluid tank (16) for storing and delivering new fluid. The new and used fluid tanks (14 and 16) are dedicated to contain only more particular fluid. A cart (16) carries the tank arrangement (12), and has load cells (26) for determining changes in weight of the tank arrangement (12) and any used fluid and new fluid contained therein. A display (58) indicates any said change in weight of said tank arrangement (12) and any fluid contained therein. The system can also include a stationary primary system (120) for use in recharging the portable device (10), without any intervening cleaning of the device. 
     Rome et al., U.S. Pat. No. 6,213,175 describes a method and apparatus, for servicing engine cooling systems, including a service inlet, a vacuum pump, a two-way solenoid interposed between the vacuum pump and the service inlet, a service outlet, a disposal hose, a new fluid tank, a pressure pump interposed between the service outlet and the new fluid tank, a three-way solenoid interposed between the service outlet and the two-way solenoid, a low-level trigger mechanism, a flow control relief valve and other elements to enhance various modes of operation. The apparatus is capable of performing various operations, including closed-loop fluid cycle, fluid vacuum, fluid top-off, fluid exchange and fluid flow control. 
     Klamm, U.S. Pat. No. 6,345,215 describes an apparatus for adding coolant to a cooling system of a motor vehicle including a cap with a resilient sleeve that expands against the inside wall of a radiator filler neck to provide an air-tight connection. A valve attached to the cap controls the flow of air and coolant through the cap. A gauge on the cap indicates the pressure inside the radiator. A venturi assembly connected to the valve provides a source of vacuum for evacuating air from the cooling system. Thereafter, coolant is drawn through the cap by the vacuum created in the system. 
     Awad, U.S. Pat. No. 6,523,580 describes an apparatus comprising a wheeled cart, and mounted on the wheeled cart a plurality of containers placed in adjacent upright attitudes. A support framework engages the wheeled cart and further provides a support framework engaging an operator&#39;s panel with operator&#39;s controls. A suction developing device, pressure developing device, conduit switching device, and conduit manifolding device, are enabled for acting together to apply vacuum and pressure exertion on fluids for driving such fluids between the containers and an automotive radiator through a system of conduits. 
     Awad, U.S. Pat. No. 6,604,557 describes a method of replacing radiator fluid in an automotive radiator including providing two gas tight containers, a fluid conducting hose with a gas tight nozzle fitted into a radiator fill pipe nipple. The method further includes the steps of filling one of the containers with a fresh radiator fluid, drawing a high vacuum on a second one of the containers, drawing spent radiator fluid into the second one of the containers using only suction from the container, thereby leaving the automotive radiator under a partial vacuum and then drawing the fresh radiator fluid, from the first one of the containers, into the radiator using only suction from the partial vacuum in the radiator. A radiator flush step may also be applied following the same method, using two additional containers, one with initial high vacuum and the other containing flush fluid. 
     Gayet, EP 1013908 describes a coolant fluid replacement device for an automobile, utilizing an open loop distribution circuit within the coolant loop during the replacement of the used coolant. The coolant loop comprises a radiator that includes an inlet from the engine and an outlet to the engine. During the coolant replacement process, the device is connected between the coolant pumps of the vehicle system. The new fluid is stored in a first reservoir. As the new fluid is pumped into the system, the old fluid is forced out into a second reservoir. 
     Our prior art search with abstracts described above teaches the use of pumps for providing the force necessary to move used fluids from automotive systems and to replace them with new fluids. However, the present invention in one embodiment uses a vacuum technique to enable fluids to be exchanged in a continuous process where used fluids are drained while new fluids are inserted into the system to replace the used fluids, and in a further embodiment, the fluids are exchanged using either internal or external pumps. The present invention provides further related advantages as described in the following summary. 
     SUMMARY OF THE INVENTION 
     The present invention teaches certain benefits in construction and use which give rise to the objectives described below. 
     Clearly, the prior art methods are complex, require expensive hardware systems, are subject to fluid spills and require considerable time and applied labor. The present invention is a method of replacing fluid in an automotive cooling system that overcomes all of these drawbacks by interconnecting a radiator fill port with a first external tank through a closed control valve, disconnecting an upper hose from an upper radiator port and reconnecting the upper hose to a second external tank containing a replacement fluid. The system produced by these interconnections is sealed with the exception of at least one of the external tanks, so that fluids are constrained for movement only within and between the engine, radiator and external tanks through the various hoses. When a pressure producing device is operated in the system, fluid is forced into and from the automotive system driving a used fluid out and replacing it with a new fluid, one of the external tanks receiving the used fluid, the other of the external tanks delivering the new fluid. This may be accomplished with or without the engine operating so that a vehicle that cannot be operated is still able to have its cooling fluid replaced. 
     A primary objective of the present invention is to provide a method that yields advantages not taught by the prior art. 
     Another objective is to provide such an invention capable of replacing engine coolant fluids in a single step process without operating the engine or its coolant pump. 
     A further objective is to provide such an invention capable of replacing engine coolant fluids by suction action. 
     A still further objective is to provide such an invention capable of replacing engine coolant fluids in a single step process using the engine coolant pump. 
     A still further objective is to provide such an invention capable of replacing engine coolant fluids in a single step process using an external pump. 
     A still further objective is to provide such an invention capable of replacing engine coolant fluids by providing a fluid pressure differential in a closed system. 
     Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate the present invention. In such drawings: 
         FIG. 1  is a schematic diagrams of a common prior art automotive engine cooling system; 
         FIGS. 2 and 3  are schematic diagrams of a first embodiment of the present invention using overflow and expansion tanks respectively, and suction for driving a fluid exchange; 
         FIGS. 4 and 5  are schematic diagrams of a second embodiment of the present invention using overflow and expansion tanks respectively, and an internal fluid pump for driving a fluid exchange. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The above described drawing figures illustrate the invention in two of its preferred embodiments, which is further defined in detail in the following description. Those having ordinary skill in the art may be able to make alterations and modifications in the present invention without departing from its spirit and scope. Therefore, it must be understood that the illustrated embodiments have been set forth only for the purposes of example and that they should not be taken as limiting the invention as defined in the following description. 
     The present invention is a method of fluid exchange particularly applicable to automotive engine cooling systems as well as other similar systems that use cooling fluids and require change-out of such fluids on a periodic basis. As shown in the schematic diagram of  FIG. 1 , the prior art teaches the well known automotive system having a motor or engine  10  engaged with an auxiliary heat exchanger  20  at the left, and a radiator  30  at the right wherein coolant fluid, referred to herein as “used fluid  5 ,” and “new fluid  6 ” is mutually exchanged through a hose system including an upper hose  40  from an upper engine port  12  to an upper radiator port  32 , a lower hose  40 ′ from a lower radiator port  32 ′ to a lower engine port  12 ′. The fluid  5  flows through the entire system including the auxiliary heat exchanger  20  as shown, driven by the engine&#39;s coolant pump  35  during normal engine operation. 
     In a first embodiment of the present method, replacing the used fluid  5  in the system, as shown in  FIG. 2 , includes the step of interconnecting the radiator&#39;s fill port  34  with a first external tank  60  using a tank hose  70 , which is not a part of the prior art system shown in  FIG. 1 . This tank hose  70  is connected through a closed control valve V 1 . A means for producing a pressure delta in the system is applied, in this embodiment, vacuum pump VP, so that a partial vacuum is drawn in the first external tank  60 , and it should be noted that this tank is then closed so that its negative pressure is able to be held at steady state until starting the fluid exchange process. Vacuum pumps and air pressure driven vacuum venturi pumps are available at low cost and are used at most automotive service facilities, so that the use of vacuum in the present process does not present a problem. Next, the upper hose  40  is disconnected from the upper radiator port  32  and is then reconnected to a second external tank  62 , through an extension hose if necessary, where the second external tank  62  contains the new fluid  6 . Now, the entire system is sealed so that all fluids within the system are constrained to move only within and between the engine  10 , with or without auxiliary heat exchanger  20 , radiator  30  and the two external tanks  60  and  62  through the upper hose  40 , lower hose  40 ′, tank hose  70  and any extensions hoses as required. Of course external tank  62  is open to atmosphere so that new fluid  6  may be drained without producing a negative pressure in tank  62 . The upper port  32  may easily be sealed with a rubber stopper and the radiator fill port  34  may be entered by a rubber stopper with a fluid conduit passed through, as is well known from common practice and chemistry laboratory technique. All other openings into the system are likewise closed off so that fluid cannot pass out of the system and air is not able to enter the system as well. In this state, the system is a closed system for purposes of fluid exchange. 
     When, as shown in  FIG. 2 , the control valve V 1  is opened, suction from the first external tank  60  pulls the used fluid  5  from the system into the first external tank  60 , while forcing the refilling of the system with the replacement fluid  6  from the second external tank  62 . This process continues until all of the used fluid  5  is out of the automotive system and is replaced by the new fluid  6 . The amount of used fluid  5  that is replaced is able to be controlled by simply setting the amount of new fluid that is initially placed into tank  62 . Clearly, the control valve V 1  can be closed once all of the new fluid  6  has been moved into the automotive system and if the amount of new fluid  6  is sufficient to fill the system, it can be assured that all of the used fluid  5  has been removed. The system may now be reconnected as it was originally, as shown in  FIG. 1  for normal system operation. 
     In the case that the used fluid  5  is sufficiently dirty, the system may be cleaned prior to replacement of the used fluid  5 . To accomplish this a partial vacuum is drawn on the automotive system, preferably through the radiator fill port  34 , and then, with the engine running, valve V 2  is opened so that a cleaning fluid in bottle  15  is sucked into the system through the radiator fill port  34  and circulated through the entire system. Of course, if the system is full, some used fluid  5  must be drained initially to make room for the cleaning fluid. After enough time has elapsed for the engine to be thoroughly cleaned, approximately five to ten minutes on average, the engine is shut down and the fluid exchange method described above may then be initiated. 
     After the used fluid  5  is replaced by the new fluid  6 , a post step of again drawing a partial vacuum in the automotive system may be taken, and then with an engine conditioning agent in bottle  15  mounted at valve V 2 , this valve V 2  may be opened to suck the conditioner into the system through the radiator fill port  34 . 
     In the above description, referring to  FIG. 2 , the radiator  30  is shown fitted with an overflow tank  80  which is usually permanently mounted to it and serves to receive any overflow of coolant from the radiator  30 . Such overflow is able to be sucked back into radiator  30  should the level in radiator  30  subsequently drop. The diagram of  FIG. 3  is identical to that of  FIG. 2  with the exception the radiator  30  does not provide fill port  34 , but instead is connected to expansion tank  80 ′, where expansion tank  80 ′ is able to sustain a vacuum without caving in. In this case, expansion tank  80 ′ provides fill port  34 . For purposes of the present invention, the radiator  30  and the expansion tank  80 ′ may be considered to be a single functional element where it matters little whether the radiator  30  or the expansion tank  80 ′ receives the tank hose  70 . In this case the port  34  is on the expansion tank  80 ′ and fluid enters the radiator  30  through the expansion tank  80 ′. In this exposition, the use of the word “radiator” shall mean either the radiator alone, or the combination of the radiator  30  and the overflow tank  80 . 
     In a second embodiment of the present invention as shown in  FIGS. 4 and 5 , the fill port  34  is interconnected with the first external tank  60  which contains the replacement fluid  6  using the tank hose  70 . Again the upper hose  40  from the upper radiator port  32  is disconnected from the radiator  30  and reconnecting to the second external tank  62 . The system is sealed, as before, so that fluids within the system are constrained to movement only within and between the engine  10 , radiator  30 , and the external tanks  60 ,  62  through the upper hose  40 , lower hose  40 ′, tank hose  70  and possible extensions thereof. A means for producing a pressure delta in the system is applied, in this embodiment, the engine&#39;s coolant pump  35 , so that suction is produced for drawing fluid from radiator  30  and thus from the first external tank  60 . In this embodiment, the engine  10  is started to engage coolant pump  35  for circulating the used fluid  5  and thereby delivering it from the system into the second external tank  62 , while refilling the system with the replacement fluid  6  from the first external tank  60 . In this case, the tanks  60 ,  62  are both open to atmosphere to accommodate the loss and gain, respectively of fluids without changes in tank pressure. Again, as in the first embodiment, the expansion tank  80 ′, as shown in  FIG. 5 , may be used to gain entry to the radiator  30  and the interconnection with the tank hose  70  is therefore from the expansion tank  80 ′ to the first external tank  60  rather than directly with the radiator  30 . 
     The enablements described in detail above are considered novel over the prior art of record and are considered critical to the operation of the instant invention and to the achievement of the above described objectives. The words used in this specification to describe the invention and its various embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification: structure, material or acts beyond the scope of the commonly defined meanings. Thus if an element can be understood in the context of this specification as including more than one meaning, then its use must be understood as being generic to all possible meanings supported by the specification and by the word or words describing the element. 
     The definitions of the words or elements of this described invention and its various embodiments are, therefore, defined in this specification to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the invention and its various embodiments below or that a single element may be substituted for two or more elements in a claim. 
     Changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalents within the scope of the invention and its various embodiments. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements. The invention and its various embodiments are thus to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted, and also what essentially incorporates the essential idea of the invention. 
     While the invention has been described with reference to at least one preferred embodiment, it is to be clearly understood by those skilled in the art that the invention is not limited thereto. Rather, the scope of the invention is to be interpreted only in conjunction with the appended claims and it is made clear, here, that the inventor(s) believe that the claimed subject matter is the invention.