Patent Abstract:
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.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of vehicles&#39; engines, and more specifically, the present invention is directed to servicing engines. 
     2. Background 
     Engine manufacturers highly recommend that engine cooling systems be serviced every 15,000 to 30,000 miles. Lack of proper service can cause engine problems due to the fact that old coolant in the vehicle&#39;s radiator system may no longer protect against rust or acids that can lead to a breakdown of the metal and aluminum parts in the engine. Periodic service intervals are recommended to protect the engine against overheating that can be caused by a breakdown of the coolant&#39;s protective properties. 
     To this end, automobile service stations utilize various systems and methods to replace old coolant in the radiator system with new coolant in accordance with the manufacturers&#39; recommendation. Conventional systems, however, suffer from many problems. To mention a few, conventional systems cause coolant drainage and are environmentally hazardous. To prevent coolant drainage, service operators must place a pan under the vehicle to avoid coolant spill. Moreover, the radiator pressure cannot be released prior to removing the radiator cap which can place service operators in danger. 
     Furthermore, conventional systems require constant operator attention. For example, at the end of the coolant exchange, the operation must end immediately, otherwise the vehicle&#39;s coolant continues to be drained, and as a result, the vehicle&#39;s engine can overheat and be damaged. Even more, at the completion of the coolant exchange, the conventional systems require the operator to add more coolant manually in order to adjust the level of coolant in the radiator system. To that end, the operator must either prepare a mixture of coolant and water, or prior to starting the coolant exchange process, save some in a separate container. At the end of the coolant exchange, the additional coolant must either be deposited in the service system tank or be added to the radiator system by the operator. Indeed, such methods are extremely labor intensive, unsafe and time consuming. 
     As another example of the shortcomings, in the existing systems, fluid flow control is achieved via a pressure switch that turns off the fluid flow completely when the system pressure reaches a predetermined level by stopping the system and/or engine and then restarting the system and/or engine when the system pressure falls below a second level. The on-to-off transitions are greatly harmful to the service system and the vehicle&#39;s engine. 
     Accordingly, an intense need exists for apparatus and method for servicing engine cooling systems that can safely and efficiently solve the existing problems in the art. 
     Further disadvantages of the related art will become apparent to one skilled in the art through comparison of the drawings and specification which follow. 
     SUMMARY OF THE INVENTION 
     In accordance with the purpose of the present invention as broadly described herein, there is provided method and apparatus for servicing engine cooling systems. 
     In particular, in one embodiment, method and apparatus of the present invention includes connecting a service inlet of the apparatus to a system fluid outlet, connecting a service outlet of the apparatus to a system fluid inlet, and pumping out the old fluid from the system through the system outlet and the service inlet, pumping in, simultaneously with the pumping in step, the new fluid from a new fluid tank to the system through the system outlet and the service inlet. In one aspect of the present invention, pumping steps are terminated when new fluid level in the new fluid tank reaches a predetermined low-level. 
     In another aspect, when new fluid level in the new fluid tank reaches a predetermined low-level, a fluid path between the service inlet and the service outlet is established such that system fluid cycles through the apparatus, but is not drained. 
     In one aspect of the present invention, the system fluid may be topped off with the new fluid remained, below the low-level mark, in the new fluid tank. 
     In yet another aspect of the present invention, the service apparatus includes a pressure relief valve coupled to the pressure pump at one end and coupled to an inlet of the new fluid tank at another end, and the relief valve opens, partially or completely, in response to system pressure. 
     In another separate aspect, the service apparatus vacuums or pumps out the old fluid without replacing it with the new fluid. 
     Other aspects of the present invention will become apparent with further reference to the drawings and specification, which follow. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. 
     FIG. 1A depicts one embodiment of an engine cooling system service apparatus; 
     FIG. 1B depicts an example control panel of the engine cooling system service apparatus of FIG. 1A; 
     FIG. 2 depicts an example flow schematic of the engine cooling system service apparatus of FIG. 1A; and 
     FIG. 3 depicts an example electrical schematic of the engine cooling system service apparatus of FIG.  1 A. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1A illustrates an exemplary embodiment of an engine cooling system service apparatus  100  of the present invention. As depicted in FIG. 1A, the service apparatus  100  comprises a front control panel  150 . The control panel  150  is shown in more detail in FIG.  1 B. 
     Referring to FIG. 1B, the control panel includes a fluid filler neck  115  for adding coolant mixture to a reservoir tank  265  (see FIG. 2) of the service apparatus  100 . The control panel  150  further includes a top-off switch  145  that is used to top-off or add coolant to the engine cooling system (not shown) upon completion of the service procedure. 
     The control panel  150  also includes a three-position mode switch  140  for selecting the service apparatus  100  modes of operation. In one embodiment, the mode switch  140 , when placed in the center position, indicates that the service apparatus  100  is in off or by-pass mode of operation. The mode switch  140 , when placed in the left position, indicates that the service apparatus  100  is in vacuum mode. The mode switch  140 , when placed in the right position, indicates that the service apparatus is in fluid exchange mode. 
     The control panel  150  includes a low-fluid-level indicator light  110  that illuminates when coolant mixture in the reservoir tank  265  (see FIG. 2) falls below a predetermined low fluid level. The control panel  150  further includes a service-in-progress indicator light  105  that illuminates when the service apparatus  100  is placed in fluid exchange mode. The control panel  150  also includes a pressure gauge  135  that displays fluid pressure in the service apparatus  100 . 
     Turning back to FIG. 1A, it is shown that the service apparatus  100  also comprises a tank-level indicator  125  that indicates the coolant mixture level in the reservoir tank  265  (see FIG.  2 ). The service apparatus  100  further comprises a used coolant hose (inlet)  120 , a new coolant hose (outlet)  130 , a disposal hose  122 , battery cables  138 , a circuit breaker  136  and a warning alarm  137 . The used coolant hose  120  is used to receive old coolant from the engine&#39;s outlet (not shown), and the new coolant hose  130  provides new coolant from the reservoir tank  265  (see FIG. 2) to the engine&#39;s inlet (not shown). The disposal hose  122  is used for transferring old coolant to a disposal tank (not shown). The battery cables  138  make it possible to utilize a vehicle&#39;s battery to provide power to the service apparatus  100 . The circuit breaker  136  provides circuit protection to the internal circuitry of the service apparatus  100 , as described below. The warning alarm  137  is used to alert the operator of the service apparatus  100 , for example, when the reservoir tank  265  (see FIG. 2) falls below a certain level or becomes empty. 
     The service apparatus  100  further comprises a flow system  200  and an electrical system  300 , as shown in FIGS. 2 and 3. 
     To begin a service process of a vehicle&#39;s engine cooling system using the service apparatus  100 , the battery cables  138  are connected to the vehicle&#39;s battery (not shown). Next, the disposal hose  122  should be inserted in the disposal tank (not shown). As a preferred step, at this point, the used coolant hose  120  should be inserted into the vehicle&#39;s overflow radiator tank (not shown). Next, the mode switch  140  should be placed in vacuum mode to evacuate approximately half of the amount of coolant in the vehicle&#39;s overflow tank. The mode switch  140  should then be placed in the off position. 
     In the next step of the process, the vehicle&#39;s overflow tank hose (not shown) should be disconnected and then used coolant hose  120  should be connected to the vehicle&#39;s radiator nipple (not shown). Next, the mode switch  140  should be placed in vacuum mode to evacuate more coolant. At this stage, the vehicle&#39;s pressure release lever (not shown) should be pulled to release any pressure and then the vehicle&#39;s radiator cap should be removed. 
     At this point, the used coolant hose  120  should be disconnected from the vehicle&#39;s radiator nipple and should be inserted into the vehicle&#39;s radiator fill neck (not shown). Next, the mode switch  140  should be placed in vacuum mode to evacuate coolant until coolant in the radiator preferably falls below the vehicle&#39;s upper radiator hose connection. As for the next step of the operation, the used coolant hose  120  should be removed from the vehicle&#39;s radiator and re-inserted into the vehicle&#39;s radiator overflow tank to evacuate the overflow tank completely using the vacuum mode of the service apparatus  100 . 
     At this stage, the vehicle&#39;s upper radiator hose should be disconnected from the vehicle&#39;s radiator inlet (not shown). Next, the new coolant hose  130  should be connected to the radiator inlet and the used coolant hose  120  should be connected to the vehicle&#39;s upper radiator hose. At this point, the mode switch  140  may be placed in fluid exchange mode to replace used coolant with new coolant from the reservoir tank  265 . This operation should continue until the coolant level has reaches a middle point in the vehicle&#39;s radiator filler neck (not shown). Next, the mode switch  140  should be placed in off mode and the vehicle&#39;s radiator cap reinstalled securely. 
     At this step, the vehicle&#39;s engine should be started and the mode switch  140  of the service apparatus  100  should be placed in fluid exchange mode. This operation should continue until the tank-level indicator  125  indicates that new coolant has fallen below a low level or until the coolant in the disposal hose  122  appears to be clean. If either condition occurs, the mode switch  140  should be placed in off position and the vehicle&#39;s engine should be turned off. 
     In a preferred embodiment, when the reservoir tank  265  falls below a predetermined low level, the low-fluid-level indicator  110  illuminates and the warning alarm  137  sounds to indicate that the fluid exchange operation has ended. At this stage, the service apparatus  100  automatically reverts to the bypass or off mode and the vehicle&#39;s coolant simply passes through the service apparatus  100  and return to the vehicle in a closed loop fashion. Once the mode switch  140  is placed in off mode, the warning alarm&#39;s  137  audible sound becomes disabled. 
     At this point, the disposal hose  122  should be removed from the disposal tank and inserted into the vehicle&#39;s coolant recovery tank (not shown). Next, the service apparatus  100  should be placed in vacuum mode via the mode switch  140  to fill the vehicle&#39;s coolant recovery tank. Once the vehicle&#39;s coolant recovery tank reaches an acceptable fluid level, the switch mode  140  should be placed in off position to end the vacuum operation. 
     For the next step of the service operation, the pressure gauge  135  should be checked to verify that service apparatus  100  indicates zero or about zero pressure. Next, the vehicle&#39;s radiator cap (not shown) should be removed in order to assure that the coolant level in the vehicle&#39;s radiator is below the upper radiator hose connection point. If the coolant level in the radiator is unacceptable, the disposal hose  122  should be inserted in a disposal tank—or preferably a clean tank—and the mode switch should be placed in vacuum mode to drain the excess clean coolant from the vehicle&#39;s radiator. Next, the service apparatus  100  should be disconnected from the vehicle and the vehicle&#39;s upper radiator hose should be connected to the radiator and overflow tank hose to radiator nipple. 
     At this stage, the new coolant hose  130  should be inserted into the vehicle&#39;s radiator filler neck and the top-off switch  145  should be turned on, i.e., placed in top-off mode, in order to fill or top-off the coolant in the radiator. Preferably, similar top-off procedure should be followed to fill or top-off the coolant in the radiator overflow tank, if deemed necessary. At this point, the service process is complete in accordance with one exemplary method of the present invention. 
     Turning to the flow system  200 , the aforementioned modes of operation of the service apparatus  100  are described below. 
     In one mode of operation, the service apparatus  100  is in off or by-pass mode when the mode switch  140  is placed in off position. The off mode is the default setting of the service apparatus  100 . In this mode, when the service apparatus  100  is connected to an operating vehicle, the service apparatus is in a flow through or by-pass mode. In other words, the coolant fluid flowing from the vehicle passes through the service apparatus  100  and return to the vehicle&#39;s system. 
     Referring to FIG. 2, the off or by-pass mode may be described as follows. A used coolant hose connector  205 , preferably a hydraulic connector, couples the used coolant hose  120  to the vehicle&#39;s radiator system. Similarly, a new coolant hose connector  235 , preferably a hydraulic connector, couples the new coolant hose  130  to the vehicle&#39;s radiator system. In the by-pass mode, a vacuum solenoid  215 , preferably a two-way solenoid, and a vacuum pump  220  are turned off such that no fluid may flow through the vacuum solenoid  215  or the vacuum pump  220 . An exchange solenoid  225 , preferably a three-way solenoid, on the other hand, is set such that the fluid passes through the exchange solenoid  225  down to a used-coolant check valve  230 . The used-coolant check valve  230  allows used fluid to flow through and towards the new coolant hose connector  235 . 
     As shown, a new coolant check valve  245  is strategically positioned to prevent flow of used coolant towards the new coolant reservoir tank  265 . A filter  210  is preferably placed in the fluid path to prevent unwanted particles from blocking the fluid paths, the solenoids  215  and  225  or the vacuum pump  220 . The pressure gauge  240  also provides the operator with the service apparatus  100  pressure based on which the operator may determine as to whether the flow has been restricted. Accordingly, in off or by-pass mode, used coolant enters the service apparatus  100 , passes through the used coolant hose connector  205  and through the used coolant hose  120  through a filter  210 , through the exchange solenoid  225 , through the used-coolant check valve  230  and then through the new coolant hose  130  and the new coolant hose connector  235  back to the vehicle&#39;s radiator system (not shown). 
     Conventional service machines, however, merely provide an open hose that causes the vehicle&#39;s fluid to flow out of the vehicle&#39;s radiator system when the vehicle&#39;s engine is running. As a result, the vehicle&#39;s radiator system loses its fluid and the vehicle&#39;s engine overheats. In this exemplary embodiment of the present invention, on the other hand, a closed loop is established in the off mode that causes the vehicle&#39;s radiator fluid to return back to the radiator system while the vehicle&#39;s engine is running. In other words, no fluid is taken out of the vehicle&#39;s radiator and no fluid is added, rather the used radiator fluid simply cycles through the service apparatus  100  and returns back into the vehicle&#39;s radiator system. The off mode of the present invention is even more advantageous in conjunction with the fluid exchange mode, as explained below, wherein the service apparatus automatically reverts to the off mode at the end of the fluid exchange mode and causes the fluid to circulate and not to be drawn out of the vehicle&#39;s radiator system at the end of the fluid exchange process. In conventional systems, however, the operator must manually control this time critical process. 
     In the vacuum mode of operation, the vacuum pump  220  and the vacuum solenoid  215  are activated to apply vacuum to the vehicle&#39;s radiator system. As a result, used coolant is pulled from the vehicle&#39;s system through the used coolant hose connector  205  and the used coolant hose  120 , through the filter  210 , the vacuum solenoid  215  and the vacuum pump  220 . The old coolant then flows to a waste check valve  270  to the disposal tank (not shown) or a clean tank, if clean fluid is being vacuumed. 
     The flow system  200  also includes a pressure pump relief valve  255  that can prevent an unwanted hydraulic pull that may be created due to human errors. An unwanted hydraulic pull may occur if the operator erroneously connects the new fluid hose  130  and the used fluid hose  120  to the vehicle&#39;s system in place of the other. In this case, an unwanted hydraulic pull is created between the new coolant hose connector  235  and the used coolant hose connector  205  and the vacuum pump  220  that may cause new fluid to be drawn from the new fluid reservoir tank  265 . The pressure pump relief valve  255  is positioned to prevent new fluid to be drawn from the reservoir  265  as a result of a hydraulic pull. 
     In conventional service machines, in order to prevent drainage of coolant into public drainage system, the operator must place a pan under the vehicle to retain spills. The performance of this step is required by the environmental law to prevent drainage of hazardous materials. 
     When the service apparatus  100  is placed in fluid exchange mode via the mode switch  140 , the service-in-progress indicator light  105  illuminates, and a pressure pump  260  and the exchange solenoid  225  are activated. In this mode, the old fluid enters the service apparatus  100  through the used coolant hose connector  205  and the used coolant hose  120 . The old fluid then flows through the filter  210 , bypassing the path including the vacuum solenoid  215  and the vacuum pump  220 , because they are both in off state, but flowing through the exchange solenoid  225  to reach the waste check valve  270 . The exchange solenoid&#39;s  225  path to the used-coolant check valve  230  is deactivated so that flow of used fluid towards the used-coolant check valve  230  is not allowed. Furthermore, the pressure pump  260  is activated to pump new fluid out of the new fluid reservoir tank  265  towards the pressure pump relief valve  255 , passed the new fluid check valve  245  towards the new fluid hose  130  and the new fluid hose connector  235  into the vehicle&#39;s radiator system. An excess pressure relief valve  250  is preferably positioned such that it is connected to the reservoir tank  265  at one end and between the pressure pump relief valve  255  and the new fluid check valve  245  at the other end. The purpose of the excess pressure relief valve  250  is to allow new fluid to revert back into the reservoir tank  265  partially or completely depending upon the rate at which the vehicle&#39;s system is accepting new fluid. The excess pressure relief valve  250  opens based on excess pressure, so that the vehicle&#39;s engine or the service apparatus  100  do not have to be stopped and restarted to adjust inflow or outflow of the fluid. Rather, the fluid flow is automatically controlled via the excess pressure relief valve  250 . In some conventional systems, an electrical switch is used to stop the pressure pump at a given pressure. Accordingly, in such machines, the flow of fluid cannot be partially controlled but path is either closed or open. 
     During the fluid exchange mode, the pressure gauge  240  provides the service apparatus  100  pressure to the operator, so the operator may determine the flow speed and whether the flow is restricted. During this operation, a used-coolant check valve  230  is positioned to prevent flow of fluid to the exchange solenoid  225 . The used-coolant check valve  230 , however, may not be used in some embodiments, since the exchange solenoid  225  may itself block flow of new fluid. Yet, the used-coolant valve  230  serves an advantageous purpose, for example in the vacuum mode, wherein the operator may erroneously utilize the new coolant hose  130  rather than the used coolant hose  120  to vacuum fluid. 
     The top-off mode of operation is activated when the top-off switch  145  is turned on. As described above, in one mode of operation the fluid exchange mode terminates when new fluid in the reservoir tank  265  reaches a predetermined low level. At this stage, the reservoir tank  265  preferably contains approximately three quarts of new fluid. The top-off mode of the service apparatus  100  overrides the low-level shut-down and allows more fluid, below the low-level in the reservoir tank  265 , to be withdrawn from the reservoir tank  265  in order to top-off the vehicle&#39;s radiator system. In conventional systems, the operator must either make a batch of new fluid by mixing water and coolant or save some new fluid in a separate container in order to manually top-off the cooling system and fill the radiator overflow tank at the end of the fluid exchange operation. 
     Activating the top-off switch  145  causes the low-fluid-level indicator light to go off. In this mode, the pressure pump  260  is activated causing new fluid to be pump out of the reservoir tank  265  towards the pressure pump relief valve  255 , passed through the new fluid check valve  245  to the new fluid hose  130  and the new fluid hose connector  235  into the vehicle&#39;s radiator system. During the top-off mode, some new fluid may revert back to the reservoir tank  265  via the excess pressure relief valve  250 . As explained above, the excess pressure relief valve  250  opens partially or completely depending upon the back pressure. 
     Turning to FIG. 3, an exemplary electrical system  300  of the present invention is illustrated. The electrical system  300  includes a circuit breaker element  305  in connection with the circuit breaker  136 . The circuit breaker element  305  provides protection to the electrical system  300  against unwanted voltage fluctuations. The electrical system  300  further includes four relays  315 ,  370 ,  375  and  380  that are set up according to the modes of operation of the service apparatus  100 . The electrical system  300  also includes electrical connections for a service light  320  and a low-level light  365  to provide illumination to the service-in-progress indicator light  105  and the low-level-fluid indicator light  110 , respectively. FIG. 3 further illustrates that the service light  320  is in communication with a diode  310  and a top-off switch  335  via the relay  315 . As a result in the fluid exchange mode, the relay  315  is activated such that the service light  320  provides voltage to illuminate the service-in-progress indicator light  105  and also to turn the pressure pump  340  on. 
     The electrical system  300  further comprises pump electrical connections  340  and  345  to provide electrical voltage to pressure pump  260  and the vacuum pump  220 , respectively. A low level switch  330  is also provided to terminate the exchange fluid mode and cause the service apparatus  100  to revert to off mode when the reservoir tank  265  reaches a predetermined low fluid level. As shown, the electrical system  300  also provides an alarm electrical connection  360  to activate or deactivate the warning alarm  137 . The alarm electrical connection is further connected to an alarm diode  355  that is coupled to the relay  370 . The electrical system  300  further comprises solenoid electrical connections  385  and  390  to control the operation of the vacuum solenoid  215  and the exchange solenoid  225 , respectively. 
     While particular embodiments, implementations, and implementation examples of the present invention have been described above, it should be understood that they have been presented by way of example only, and not as limitations. The breadth and scope of the present invention is defined by the following claims and their equivalents, and is not limited by the particular embodiments described herein.

Technology Classification (CPC): 5