Abstract:
A method and apparatus for removing transmission fluid from the transmission fluid reservoir of a vehicle and the associated fluid cooler with an optional transmission fluid replacement includes a quick connect valve located in the transmission fluid recirculation system positioned upstream from the fluid cooler for selective connection to a source of pressurized air and a source of fresh transmission fluid. The quick connect valve restricts the flow of the pressurized gas and fresh transmission fluid in only one direction to direct the flow of pressurized gas and fresh transmission fluid through the fluid cooler and then to the transmission reservoir. A quick connect valve may be also located in a drain plug of the transmission reservoir for communication to a waste receptacle during the removal of the waste transmission fluid.

Description:
This application claims priority of U.S. Provisional Application Ser. No. 60/432,132 filed on Dec. 9, 2002. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a method and apparatus for removing at least a portion of waste transmission fluids in an automotive vehicle or similar device and selectively exchanging with fresh transmission fluid. 
     BACKGROUND OF THE INVENTION 
     Routine maintenance of a vehicle includes the periodic checking and replenishment of transmission fluid in the vehicle. The transmission fluid lubricates gears employed in the connection between the internal combustion engine and the associated drive shaft for transferring power from the engine to the drive shaft of the vehicle or powertrain. Transmission fluid is lost, reduced, or degraded over time. Additionally, metallic particles can accumulate in the transmission fluid which contribute to abrasive wear of the gears, especially powertrains that operate in dusty environments. Replenishment of the transmission fluid and removal of contained particulate material can prolong the life of the transmission and improve its performance. Changing of transmission fluid can present many of the same problems of time, expense, and environmental safety that are presented with lubricating oil changes. Additionally, given the design of most transmission systems, accomplishing transmission fluid removal and replacement in a clean and efficient manner is problematic at best. 
     Therefore, it would be desirable to provide a system which reduces the amount of waste fluid handling and exposure as well as the risk of environmental damage due to spills and the like during fluid transfer. It would further be desirable to provide a method which could be easily employed at locations convenient to the typical location of the vehicle or powertrain to be serviced with benefits such as time savings, money savings, convenience, minimum exposure to spent or fresh fluid, environmental protection, energy conservation, and longer lasting, better performing vehicles and sub-components. 
     SUMMARY OF THE INVENTION 
     It is the intent of the present invention to address the aforementioned issues. 
     An aspect of the invention includes an apparatus for changing the transmission fluid in a transmission having a transmission fluid reservoir. The apparatus includes at least one receptacle for spent transmission fluid, and at least one container for holding a supply of replacement transmission fluid. The apparatus for changing transmission fluid includes a valve upstream from the transmission cooler in the transmission recirculation system to facilitate the removal of waste fluid from the transmission fluid reservoir and introduce clean transmission fluid into the vehicle. 
     The invention further includes the method of changing the transmission oil in an engine including the steps of attaching a waste transmission fluid hose for withdrawing the transmission fluid from the engine, attaching a purge gas supply hose for supplying compressed gas to the engine, and purging the transmission passages of transmission fluid and draining the transmission fluid from the transmission reservoir. 
     The process further includes removing the transmission fluid filter and replacing a new transmission filter on the engine. Following replacement of the transmission fluid filter, filling the transmission with new transmission fluid is performed by metering the fluid through a transmission fluid supply hose. This provides changing of transmission fluid in a close system in an environmentally responsible manner and also with the safety to the operator to eliminate his exposure to hazardous used transmission fluid. 
     Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
         FIG. 1  is a diagram of the apparatus for changing the transmission fluid in an internal combustion engine with a transmission; and 
         FIG. 2  is a schematic diagram of a transportable device of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in  FIG. 1 , the present invention includes a transmission oil changing apparatus which is separable from the transmission of an internal combustion engine. 
     A typical transmission hydraulic system  10  maintains the transmission oil in a reservoir at a low portion  12  of the transmission  14 . An oil pump  16  in the transmission  14  pumps the oil through a filter  18  before circulation through the transmission hydraulic system  10 . The oil in the transmission  14  can get quite hot. Overheating reduces the transmission performance and can damage the transmission  14 . In a typical system, transmission  14  is connected by conduits  15  to an oil cooler tube  20  in the side tank or bottom tank of the radiator  22  of the engine  24 . The oil cooler tube  20  is immersed in the cooler coolant in the radiator  22  and is therefore cooled. This cools the transmission oil that then passes through conduit  17  back to the transmission reservoir  12 . The cooled transmission fluid then flows for recirculation within the transmission  14 . 
     The changing of transmission fluid in a vehicle is part of routine maintenance. The transmission  14  lubricates gears that connect the internal combustion engine with a drive shaft for transferring power from the engine  24  to the vehicle. Over time, the transmission fluid will accumulate metallic particles that contribute to abrasive wear of the gears. The present invention includes a transmission fluid changing apparatus  30  which is separable from the transmission  14 . The transmission fluid changing apparatus  30  as schematically presented in  FIG. 1 , provides for changing of transmission fluid from the transmission  14 . The transmission changing device  30  includes a conduit  61  for connection to the transmission hydraulic system on a vehicle to be serviced, and another conduit  52  for connection to the transmission oil reservoir  12 . 
     To facilitate the changing of transmission fluid in a vehicle, an adapter  32  may be used that provide access to the transmission hydraulic system  10  upstream from the transmission fluid cooler  20 . The adapter  32  preferably includes a T-valve  32  for disposing in line within the transmission hydraulic system  10  preferably upstream to the transmission cooler  20 . However, it is envisioned that at some point and time manufacturers may modify the configuration of transmission hydraulic system to provide the appropriate coupling connections as required for the present invention as original equipment manufacturers optional, or standard equipment. Therefore, the present invention does not require the T-valve  32  disclosed in this application, but rather only requires a coupling connection  32  capable of effecting the removal of the transmission oil and the replenishment of the transmission oil in fluid communication with the transmission cooler  20  and transmission oil pan reservoir  12 . The transmission fluid changer apparatus  30  is releasibly connectable to the coupler connection  32  via conduit  61  having a quick connector  63 . The coupling connection  32  has a quick disconnect coupler  35  of a type disclosed in U.S. Pat. No. 5,588,502 and herein incorporated by reference for connection to the connector  63 . 
     Referring to  FIG. 1 , the transmission oil removal apparatus  30  of the present invention includes a waste transmission oil collection container  33 . The transmission oil removal apparatus  30  also includes a connection to a source of pressurized air or general shop air  34 . When removing the waste transmission oil, pressurized air is forced through the transmission hydraulic system  10 . During the removal of the waste transmission oil from the transmission hydraulic system  10 , conduit  61  is connected to coupling connection  32  at the quick disconnect coupler  35 ; and conduit  40  is disposed in waste container  33 . Pressurized air may be forced through coupling connection  32 . Connection to the source of pressurized air may be controlled by appropriate valves  36  for opening and closing the communication of the pressurized air with the transmission oil removal apparatus. The transmission oil changing apparatus may include a venturi  38  which is connected to the source of pressurized air by way of the conduit  40 . The venturi  38  communicates with the interior  31  of the spent transmission oil collection container  33  by way of a check valve  42 . The check valve  42  may have a perforated surface  44  which allows air within the interior of the container to be drawn out by the action of the venturi  38  when pressurized air passes therethrough. The perforated surface  44  of the check valve  42  allows air to bypass a check valve ball  46  until the level of the spent transmission oil within the container rises up and causes the ball  46  to engage the check valve  42 , thereby stopping further action of the venturi  38  on the interior of the waste container. 
     The transmission  14  has a transmission oil reservoir  12  provided with the quick disconnect coupling  48 . The quick disconnect coupling  48  may be of a type disclosed in U.S. Pat. No. 5,588,502 as disclosed for use on an oil pan of an engine and which is herein incorporated by reference. The quick disconnect coupling  48  is connected to an appropriate coupling  50  by way of a flexible conduit  52 . The connection  50  is preferably a swivel connector along the conduit  52  to rotate thereabout for the ease of use. Preferably, the conduit  52  is transparent so that the operator can visually confirm the flow of transmission fluid therethrough from the transmission reservoir  12  in the interior  31  of the collection container  32 . It can be seen that when the appropriate control system is utilized to activate the source of air pressure  34  such as the turning on or off of the valve  36  which may be done manually or through other appropriate known on/off valves, pressurized air passing through a venturi  38  creates a vacuum within the interior of the collection container  32  and thereby forces transmission oil to be evacuated at a rapid rate from the transmission oil reservoir  12  via conduit  52 . The spent transmission oil collection container  32  may have a vacuum gauge  54  which provides the operator with an indication that the vacuum is still being created inside the interior  31  of the container  32 . When the transmission oil is exhausted from the transmission fluid reservoir  12  by way of the aforementioned process, the conduit  40  is connected to atmospheric pressure which results in the loss of vacuum in the container  32 . The source of pressurized air may then be terminated and the quick disconnect coupling  50  disconnected to separate the conduit  52  from the transmission fluid reservoir  12 . 
     Once the flow of pressurized purging air has been terminated, the operator can then open the bottom pan of the transmission fluid reservoir  12  and remove the spent filter medium  18  therefrom, without spilling transmission fluid in order to replace the spent filter medium  18  with a new filter medium. Once the filter  18  has been replaced, the bottom pan is sealed to the transmission fluid reservoir  12 . After the conduit  52  been disconnected from the transmission fluid reservoir, the on/off valve  36  is closed isolating the venturi  38  and the conduit  40  from communication with the source of pressure. At the same time, a new transmission fluid supply  60  can be provided to the transmission  14 . 
     Although the transmission includes the transmission fluid reservoir  12  with a transmission fluid dipstick (not shown) that extends thereto to the bottom of the transmission fluid reservoir  12  and which provides a means for filling the transmission reservoir  12 , the transmission oil removal apparatus  30  offers an alternative and an environmentally safe means for replenishing the transmission oil into the transmission reservoir  12 . The fresh transmission oil supply source  60  consists of a reservoir or transmission fluid container  60  which is connected by way of a conduit  64  to a hand operated on/off valve  62 , and conduit  66  to conduit  61 . It can thus be seen that when pump  65  is actuated, transmission oil from the reservoir  60  will be directed into the valve  32  and through the cooler as represented by the tubes  20  in the radiator  22 . The transmission fluid/oil is forced from the cooler  20  and passes to the transmission fluid reservoir  12 . A check valve  39  located in the T-valve  32 , prevents transmission fluid under pressure into conduit  15  from being directed back into the transmission without first flowing through the cooler  20  and then into the transmission fluid reservoir  12 . When the appropriate amount of transmission fluid is added to the transmission reservoir, the pump  65  to the fresh transmission oil supply is deactivated. The appropriate amount of transmission fluid can be determined by viewing the transmission dipstick. 
     As shown in  FIG. 2 , the transmission oil removal apparatus  30  may be contained in a transportable unit  80 . In the mobile unit  80 , the waste container  33  may become full during the transmission oil changing process. If the waste transmission oil collection container  33  becomes full to the point where the level of spent transmission fluid rises up to the check valve  42  so as to cause the check valve ball  46  to engage the valve opening, it will close the check valve  42  and prevent further communication from the venturi  38 . The vacuum in the interior  31  of the container  33  will drop off and the gauge  54  will indicate to the operator that it is time to turn off the source of pressurized air to the venturi  38  and to evacuate the collection container  33 . Evacuation from the collection container  33  can be done in a variety of ways. Preferably the conduit  40  is disconnected from the venturi  38  and the conduit  52  is disconnected from the transmission oil pan  12 . The mobile unit  80  may be on appropriate wheels  82  and the transmission oil collection container  33  may be moved to a new desirable location. There may be a shut off valve  35  provided at the lower end of the container  33  which may be connected to a suitable drain line which in turn may be connected to a larger storage container (not shown). 
     Optionally, a suction pump may be utilized and connected to the drain line to force the transmission oil to flow at a greater rate from the interior of the container. Alternatively, a source of pressurized air may be connected via an on/off valve to an inlet at the top portion of the collection container  33 . It is evident that when the shut-off valve  35  is opened and pressurized air is forced into the interior, the spent transmission oil within the container  33  will be forced at a greater rate of flow through the shut-off valve and drain line for appropriate disposal. When this arrangement is used, the pump would not be utilized. Check valves connected to the drain line seal the interior of the container drawing this evacuation operation. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. Such modifications can include the use of mechanically operated pumps, electrically operated sensors, and mechanically driven vacuum generating pumps in lieu of the venturi  38 . One of the advantages of using the venturi  38  is that the distribution of the pressurized air does not require any electrical devices.