Abstract:
A conduit assembly for transferring heated fluid from a pump to a heat exchanger and to return cooled fluid from the heat exchanger to the pump is disclosed. The conduit assembly includes a flexible inner conduit disposed within a relatively rigid conduit. The heated fluid travels through the flexible inner conduit from the pump to the heat exchanger and the cooled fluid returns to the pump in the space between the outer diameter of the flexible inner conduit and the inner diameter of the rigid conduit. The conduit assembly includes a fluid splitter nipple and a fluid splitter body to split the incoming and outgoing fluid into the inner and outer conduits. The relatively warmer fluid from the pump is exposed to the temperature of the fluid passing simultaneously through the outer conduit, rather than being exposed to the ambient environmental conditions as in conventional hoses. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Description:
TECHNICAL FIELD 
   The present invention relates generally to fluid transfer assemblies and, in particular, to a fluid transfer assembly including a flexible conduit disposed within a relatively rigid conduit for transferring fluid to and from a heat exchanger, such as a heater circuit in a motor vehicle. 
   BACKGROUND OF THE INVENTION 
   A conventional automobile heating system uses an engine housing including a cylinder block, a cylinder head and the like. A main heat receiving chamber is formed in the cylinder head and the associated portions. The main heat receiving chamber is fluidly connected to a radiator and a heater core by a conduit which is opened and closed by a thermostat device. Cooling water is circulated through the main heat receiving chamber, liquid conduits, the radiator and the heater core by a water pump. 
   The cooling water removes heat from the operating engine to cool the latter, and is in turn heated. The heat of the cooling water is then supplied to the heater core to warm the interior of an automotive body, e.g., a passenger cabin. When the cooling water is excessively heated by the heat of the engine, the thermostat opens the conduit to deliver the cooling water to the radiator for cooling. 
   Referring now to  FIG. 7 , there is shown a conventional heating/cooling system  100  for an internal combustion engine  112 . The heating/cooling system  100  includes a radiator  114  through which coolant is pumped by a water pump  116  which pumps coolant fluid through the engine and into the radiator  114  by an inlet  118  that is connected to the block of the engine  112  by a hose  120 . Coolant is cooled by a core  122  of the radiator  114  before being returned to the engine  112  by a hose  124  that is connected to an outlet  126  of the radiator  114 . A filter element  132  is typically disposed between the core  122  and an outlet header tank  130 . Also associated with the heating/cooling system  100  is a heater system in the form of a heater core or heater exchanger  134  that has an inlet hose  136  connected to the block  113  of the engine  112 . A separate return hose  138  connects the heater core  134  to the water pump  116 . 
   One problem associated with conventional heater systems is that two separate hoses are required for transporting fluid from the pump to the heater core or heat exchanger, and from the heater core back to the pump. In this type of conventional design, both the inlet hose and the return hose are exposed to ambient environmental conditions, such as temperature, humidity, or the like. As a result, the thermal efficiency of the heater system may be compromised because of such exposure to the ambient environmental conditions. 
   SUMMARY OF THE INVENTION 
   The inventors of the present invention have recognized these and other problems associated with conventional heater assemblies. To this end, the inventors have developed a conduit assembly that utilizes a fluid splitter that allows fluid to travel in both directions within an inner conduit disposed within an outer conduit. This design allows the inner conduit that supplies the fluid to a heat exchanger to be surrounded with heated fluid, instead of being exposed to the ambient environment conditions as in conventional heater systems. 
   In the invention, the fluid flowing from the pump is attached to a fluid splitter that has been designed to direct fluid to pass through the inside diameter of the fluid transfer assembly. The opposing end of the fluid splitter connects to the inner conduit disposed within an outer conduit. The fluid within the inner conduit flows into a heat exchanger, such as a heater core, by passing through another fluid splitter connected to the heat exchanger. The fluid that flows from the heat exchanger passes through the fluid splitter and is directed into the outer conduit. Thus, the relatively warmer fluid passing through the inner conduit is exposed to the temperature of the fluid passing simultaneously through the outer conduit back to the pump for another cycle, rather than being exposed to the ambient environmental conditions as in conventional heater assemblies, thereby improving the thermal efficiency of the fluid system. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
       FIG. 1  is a side view of a conduit assembly for transferring fluid showing the various components when the conduit assembly is disassembled; 
       FIG. 2  is a side view of the conduit assembly when the inner conduit is assembled over one end of a fluid splitter nipple in accordance with the invention; 
       FIG. 3  is a side view of the conduit assembly when the outer conduit is assembled over the inner conduit in accordance with the invention; 
       FIG. 4  is a side view of the conduit assembly when the fluid splitter body is assembled over the other end of the fluid splitter nipple to completely assemble the conduit assembly in accordance with the invention; 
       FIG. 5  is a perspective view of a conduit assembly for transferring fluid showing the various components according to another embodiment of the invention; 
       FIG. 6  is a cross-sectional view of the conduit assembly taken along line  6 — 6  of  FIG. 5 ; and 
       FIG. 7  is a schematic view of a conventional heater system in combination with an internal combustion engine and subsystems in which two heater hoses are required to transfer fluid to and from the heater core. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to  FIGS. 1–4 , a conduit assembly  10  for transferring fluid is shown according to an embodiment of the invention. The conduit assembly  10  includes an inner conduit  12 , an outer conduit  14 , and a fluid splitter nipple  16  and a fluid splitter body  18 . The conduit assembly  10  is adapted to be attached to the pump  116  and the heater core  134  of a conventional heater system, such as the heater system  100  described above. 
   The inner conduit  12  extends longitudinally to supply fluid, such as water, from the pump  116  to a heat exchanger  134 , such as a heater core, or the like. The inner conduit  12  includes a generally annular body  20  with a generally circular cross-sectional shape. The inner conduit  12  may include a plurality of ribs  22  extending radially outwardly and longitudinally from the body  20  for locating or centering the inner conduit  12  relative to the outer conduit  14  such that the inner conduit  12  is substantially concentric with the outer conduit  14 . In addition, the ribs  22  divide the interior of the outer conduit  14  into a plurality of channels to allow fluid flow longitudinally between the outer conduit  14  and the inner conduit  12 . Preferably, six ribs  22  are provided approximately sixty degrees apart to provide six channels. However, the invention is not limited by the number of ribs and the invention can be practiced with any desired number of ribs, including no ribs, that will keep the inner conduit properly disposed within the outer conduit and to provide adequate flow characteristics between the inner and outer conduits. 
   The dimensions of the inner conduit  12  are such that the inner conduit  12  can be sealingly disposed within the outer conduit  14 . For example, the inner and outer diameters of the body  20  may be approximately 0.618 inches (15.697 mm) and 0.700 inches (17.78 mm), respectively. The ribs  22  may extend radially outward approximately 0.080 inches (2.032 mm) from the body  20 . Thus, the outer diameter of the inner conduit  12  with the ribs  22  may be slightly larger than approximately 0.860 inches (21.844 mm). The inner conduit  12  is preferably made of a relatively flexible material, such as rubber, thermoplastics, thermosets, or the like. 
   The outer conduit  14  extends longitudinally and is adapted to be disposed over the inner conduit  12 . The outer conduit  14  is hollow and has a generally circular cross-sectional shape. The outer conduit  14  includes an end fitting, shown generally at  23 , with a first end portion  24  and a second end portion  26 . Both the first and second end portions  24 ,  26  are generally circular in cross-sectional shape. The first end portion  24  has an inner diameter slightly smaller than the second end portion  26  such that the inner conduit  12  is sealingly disposed within the first end portion  24 . For example, the first end portion  24  may have an inner diameter of approximately 1.000 inches (25.4 mm), whereas the second end portion  26  may have an inner diameter of approximately 1.060 inches (26.924 mm). The second end portion  26  includes a recess  28  for receiving a sealing element  30 , such as an O-ring, or the like for sealing the fluid splitter body  18  in the assembled conduit assembly. A shoulder  32  separates the first end portion  24  from the second end portion  26 . The shoulder  32  acts as a stop for the fluid splitter body  18  during assembly of the conduit assembly  10 . The outer conduit  14  is made of a relatively rigid material, such as a metal material, or the like. 
   The fluid splitter nipple  16  is generally cylindrical in shape and has a cavity or passageway  34  extending from one end  36  to an opposite end  38  for allowing the heated fluid from the pump  116  to pass therethrough. One end of the fluid splitter nipple  16  includes an inner conduit receiving portion  40  having an outer diameter similar to the inner diameter of the body  20  of the inner conduit  12  such that the flexible inner conduit  12  can be sealingly disposed over the inner conduit receiving portion  40 . For example, the outer diameter of the inner conduit receiving portion  40  may be approximately 0.620 inches (15.75 mm) and the inner diameter of the body  20  may be approximately 0.618 inches (15.697 mm). The inner conduit receiving portion  40  may include one or more recesses  42  forming a serrated pattern for assisting in gripping and sealing the inner conduit  12 . The inner conduit receiving portion  40  include a plurality of ribs  44  extending radially outward approximately 0.266 inches (6.75 mm) from an outer surface  46  of the inner conduit receiving portion  40 . The plurality of ribs  44  acts as a stop for the inner conduit  12  when the inner conduit  12  is disposed over the inner conduit receiving portion  40  during assembly. In addition, the plurality of ribs  44  acts as a stop for the outer conduit  14  when the outer conduit  14  is disposed over the inner conduit  12  during assembly. Further, the ribs  44  locate and center the fluid splitter body  18  relative to the fluid splitter nipple  16  such that the fluid splitter nipple  16  is generally concentric with respect to the fluid splitter body  18  when the conduit assembly  10  is assembled. 
   The fluid splitter nipple  16  also includes a fluid splitter body receiving portion  48  having a relatively smaller outer diameter portion  50 , a relatively larger outer diameter portion  52  and a step or ledge  54  therebetween. The smaller outer diameter portion  50  includes a raised bead  56  extending radially outward for connecting the smaller outer diameter portion  50 , depending on which end of the inner and outer conduits  12 ,  14  the conduit assembly  10  is attached, to an outlet (not shown) of the pump  116  or to the intake (not shown) of the heater core  134 . In the illustrated embodiment, the bead  56  has an outer diameter that is approximately equal to the outer diameter of the larger outer diameter portion  52 . The larger outer diameter portion  52  includes a recess  58  for receiving a sealing element  60 , such as an O-ring, or the like for sealing the fluid splitter body  18  in the assembled conduit assembly. A raised lip  62  separates the fluid splitter body receiving portion  48  from the inner conduit receiving portion  40 . The raised lip  62  also acts as a stop when the fluid splitter body  18  is disposed over the fluid splitter nipple  16  during assembly. 
   The fluid splitter body  18  is generally cylindrical in shape and has a cavity  64  extending longitudinally therethrough. One end of the cavity  64  of the fluid splitter body  18  has an opening  66  having a diameter slightly larger than the outer diameter of the larger diameter portion  48  of the fluid splitter nipple  16  for allowing the larger diameter portion  52  of the fluid splitter nipple  16  to pass therethrough. The other end of the cavity  64  of the fluid splitter body  18  includes a radially enlarged opening  68  capable of receiving the end fitting  23  of the outer conduit  14 . The fluid splitter body  18  has an outer surface  72  with a relatively larger outer diameter than an outer surface  74  at the end proximate to the opening  68 . The outer surface  72  may include a beveled surface  76  at the end proximate to the opening  66 . As mentioned earlier, the shoulder  32  of the end fitting  23  of the outer conduit  14  acts as a stop for the fluid splitter body  18  when the fluid splitter body  18  is slipped over the end fitting  23  during assembly of the conduit assembly  10 . 
   The fluid splitter body  18  also includes a passageway  70  extending radially inward from the relatively larger diameter outer surface  72  of the fluid splitter body  18  and into the cavity  64  for fluid communication therewith. The passageway  70  enables the relatively cooler return fluid flowing through the outer conduit  18  from the heater core  134  to be in fluid communication with the pump  116 . 
   To assemble the conduit assembly  10  of the invention, one end of the inner conduit  12  is disposed over the inner conduit receiving portion  40  of the fluid splitter nipple  16 , as shown in  FIG. 2 . The recesses  42  formed in the outer surface  46  of the inner conduit receiving portion  40  assist in gripping and sealing the inner conduit  12  when disposed over the inner conduit receiving portion  40 . Although not shown in  FIG. 2 , the inner conduit  12  can be disposed over the inner conduit receiving portion  40  until the inner conduit  12  abuts the ribs  44  of the fluid splitter nipple  16 . Next, the outer conduit  14  is disposed over the inner conduit  12  until the second end portion  26  of the outer conduit  14  abuts the ribs  44  of the fluid splitter nipple  16 , as shown in  FIG. 3 . It should be appreciated that the outer conduit  14  can be disposed over the inner conduit  12  prior to the inner conduit  12  being disposed over the inner conduit receiving portion  40  of the fluid splitter nipple  16 . Then, the fluid splitter body  18  is disposed over the fluid splitter nipple  16  until the end of the fluid splitter body  18  abuts the lip  62  of the fluid splitter nipple  16 , as shown in  FIG. 4 . At this point, the fluid splitter body  18  is sealed by the sealing elements  30 ,  60  of the outer conduit  14  and the fluid splitter nipple  16 , respectively. Once the fluid splitter body  18  is disposed over the inner and outer conduits  12 ,  14 , the fluid splitter nipple  16  and the fluid splitter body  18  can be attached so as to be in fluid communication with either the pump  116  or the heater core  134 . 
   In operation, the fluid splitter nipple  16  that attaches the conduit assembly  10  to the pump  116  directs the heated fluid from the pump  116  into the inner conduit  12  for transferring the heated fluid from the pump  116  to the heater core  134 . The fluid splitter body  18  attached to the pump  116  also directs the relatively cooler fluid transferred from the outer conduit  14  back to the pump  116  through the passageway  70 . 
   Conversely, the fluid splitter nipple  16  that attaches the conduit assembly  10  to the heater core  134  directs the heated fluid transferred from the pump  116  and the inner conduit  12  to the heater core  134 . The fluid splitter body  18  attached to the heater core  134  also directs the relatively cooler fluid from the heater core  134  into the outer conduit  14  for transfer back to the pump  116  for another cycle. Thus, the relatively warmer fluid passing through the inner conduit  12  is exposed to the temperature of the fluid passing simultaneously through the outer conduit  14 , rather than being exposed to the ambient environmental conditions as in conventional heater assemblies, thereby improving the thermal efficiency of the fluid transfer system. 
   Referring now to  FIGS. 5 and 6 , a conduit assembly  10 ′ is shown according to another embodiment of the invention. The conduit assembly  10 ′ includes an inner conduit  12 ′, an outer conduit  14 ′, and a fluid splitter nipple. In this embodiment, the inner conduit  12 ′ and the fluid splitter nipple  16 ′ may be substantially identical to the inner conduit  12  and the fluid splitter nipple  16  of the earlier embodiment of the invention, except that the fluid splitter nipple  16 ′ may be of substantially uniform diameter along its length. In addition, the outer conduit  14 ′ is attached to the fluid splitter nipple  16 ′ by crimping one end of the outer conduit  14 ′. A sealing member  60 ′, such as an O-ring, or the like, can be used to provide a seal between the outer conduit  14 ′ and the fluid splitter nipple  16 ′. 
   In addition, a connecting member  180  is attached to the outer conduit  14 ′ by brazing, welding, or the like, to form a “saddle joint” type of connection with the outer conduit  14 ′. The connecting member  180  may include a raised bead  182 , similar to the raised bead  56 ′ on the fluid splitter nipple  16 ′, for connecting the conduit assembly  10 ′ to the intake (not shown) of the heater core  134 . As shown in  FIGS. 5 and 6 , the conduit assembly  10 ′ is simpler in construction as compared to the conduit assembly  10  of the earlier embodiment of the invention because the fluid splitter body  18  is not needed. 
   It should be understood that the aforementioned and other various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. For example, the principles of the invention can be practiced with other types of conduits that contain a fluid, such as a power steering hose, a clutch hose, or the like. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby.