Abstract:
An after-run heating system for a vehicle includes a pump and a control circuit therefor located in the engine compartment and a separate vehicle fan control circuit located in the passenger compartment. The after-run heating system is configurable at the time of installation as an interconnected system or as a divided system. The interconnected system has direct electrical connections between the control circuits. The divided system has no mechanical, electrical or electromagnetic connections between the control circuits. The components in both the engine and passenger compartments function co-dependently, either as an interconnected system or as a divided system.

Description:
BACKGROUND OF THE INVENTION 
   The present invention generally relates to automotive and vehicular heating systems, and more particularly, to an improved separated or connected system for continuing the heating of an automotive or vehicular interior after the engine has been turned off. 
   In conventional vehicular heating systems having a water-cooled engine, a hot water circulation conduit or circuit is provided which uses the heated engine coolant to provide heat to the passenger compartment of the vehicle. When the engine is operating, hot coolant from the engine is circulated through a heater core. A heater fan pushes air through the core, where it is heated by the hot engine coolant, and then into the passenger compartment. Accordingly, in these conventional heating systems, it was necessary to leave the engine idling, even when the vehicle was stationary or unoccupied, in order to keep a vehicle&#39;s passenger compartment warm. Only with the engine idling could hot coolant be pumped through the heater core. Such excessive idling causes unnecessary fuel consumption and air pollution. 
   In order to prevent such excessive idling, after-run heaters have been developed for continuing the heating of vehicle interiors even after the engine is turned off. After-run heaters utilize much of the coolant heat by transferring it into the passenger compartment. An example of such a heater is shown in Perhats, U.S. Pat. No. 4,308,994, the disclosure of which is incorporated herein by reference. A magnetically-coupled pump with low battery drain, along with auxiliary control components, is utilized to circulate the still-hot engine coolant through the vehicle&#39;s heater core and to run the vehicle&#39;s heater fan while the engine is off. 
   Those skilled in the art will recognize that systems of the type shown in the U.S. Pat. No. 4,308,994 require the interconnection between components located within the passenger compartment and components located within the engine compartment. More specifically, components such as the seasonal switch, indicator and fan motor controls are located in the passenger compartment inside or under the dash, whereas the engine coolant pump and temperature sensor are located in the engine compartment. The interconnection of these components requires the installing of wiring through the firewall between the two compartments. The wiring may pass through the firewall. This type of system is referred to herein as an interconnected system. Those skilled in the art will recognize that, depending on the specific configuration of the vehicle&#39;s firewall, engine compartment and dash, installation of an interconnected system can prove to be time-consuming, difficult, and therefore very costly. 
   These problems were addressed in the after-run heater of Perhats, U.S. Pat. No. 6,116,552, the disclosure of which is incorporated herein by reference. A pump and first control circuit therefore are located in the engine compartment of the vehicle. The first control circuit allows the pump to continue circulating heated engine coolant through the heater core of the vehicle after the engine has been turned off. A second control circuit, located in the passenger compartment of the vehicle, continues to operate the heater fan which blows air through the heater core and into the passenger compartment after the engine has been turned off. The first and second control circuits have no mechanical, electrical or electromagnetic interconnection therebetween but nevertheless are interrelated and codependent. This type of system is referred to herein as a divided system. 
   Those skilled in the art will recognize that installation of after-run heating systems involves a broad range of vehicles sizes, types and styles. Accordingly, the system and its installation can prove to be costly due to the required specificity in manufacture, distribution and inventory for each vehicle. Furthermore, in some vehicles the arrangement of the heating system, firewall and related components renders installation of the interconnected after-run heating system relatively straightforward. That is, there is no need for the divided system of the U.S. Pat. No. 6,116,552. In other vehicles it can range from difficult to impossible to install the interconnected system of the U.S. Pat. No. 4,308,994. In such vehicles the divided after-run heating system of the U.S. Pat. No. 6,116,552 is required. 
   SUMMARY OF THE INVENTION 
   In view of the foregoing, it is desirable to develop an after-run heating system which is configurable at installation as an interconnected system, with through the firewall connections, or as a divided system, with no mechanical, electrical or electromagnetic connection extending through the firewall. 
   It is further desirable to develop an after-run heating system whose passenger and engine components are easily interconnected between the firewall placed therebetween. 
   It is further desirable to develop an after-run heating system which accommodates the varying installation needs of vehicles of varying size, type and style. 
   The present invention provides a system for controlling after-run heating of a vehicle&#39;s interior comprising, a pump and a control means thereof, usually located in the engine compartment, and a related but separate vehicle fan control means located in the driver&#39;s compartment. This after-run heating system is configurable at installation as a single interconnected system or as a divided system with no mechanical, electrical or electro-magnetic connection between the separated components. The components in both the engine and passenger&#39;s compartments function synergistically and co-dependently, either as an interconnected or divided system. 
   The present invention provides a single, convertible system, that can be configured by the installer at the time of installation, as a single, interconnected system or, when necessary, as a divided system with engine compartment and passenger compartment components separated mechanically, electrically, and electro-magnetically but operating together as functionally codependent elements of the system. 
   These and other desired benefits of the preferred forms, including combinations of features thereof, of the invention will become apparent from the following description. It will be understood, however, that a device could still appropriate the claimed invention without accomplishing each and every one of these desired benefits, including those gleaned from the following description. The appended claims, not these desired benefits, define the subject matter of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a circuit diagram of a fan control system, located in the passenger compartment, installed as a separated system. 
       FIG. 2  is a circuit diagram of a pump/thermostat control system, located in the engine compartment, installed as a separated system. 
       FIG. 3  is a circuit diagram of a fan control system and a pump/thermostat control system, connected to one another so as to form a directly connected system. 
       FIG. 4  is a circuit diagram of an alternate embodiment, showing connection between the fan control component and an existing vehicle heater fan when a heater relay is available. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Looking at  FIG. 1 , vehicular heating systems, even those not having an after-run heating system, generally comprise a heater fan motor  5  connected to a power source through line  7 . The power source is typically in the form of a battery or alternator. A ground line  6 , a fuse/circuit breaker  8 , and a fan speed control switch  12  complete the fan motor circuit. When the vehicle ignition is turned on, the heater fan motor  5  is connected to the power source, via an existing power supply conductor  7 . On the other hand, when the vehicle ignition is off, the heater fan motor  5  is disconnected from the power source so that the heater fan motor  5  will not operate even if the fan speed control switch  12  is on. 
   In accordance with the goals of this invention, the main functioning components that provide pumping and engine coolant temperature sensing (module  1  of  FIGS. 1 and 2 , and the fan control module  3  of  FIGS. 1 and 3 ) are convertible at installation, that is, they can be set up either as a separated, unconnected system or as a connected system with through-the-firewall connections. These components are identically-configured, whether the system is separated or connected. 
     FIGS. 1 and 3  illustrate an after-run heating system which uses the existing vehicle heater to continue vehicle interior heating. More specifically, a method for directly connecting an after-run heating circuit to an existing heater fan includes severing conductors  9  and  11  and inserting the fan control module  3  into the fan circuit as follows. Conductor  11  is connected to the movable transfer contact  16  of a fan control relay  14 . Conductor  9  is connected to a fixed contact  15 . With fan control relay  14  dormant (ignition on), the original source of heater fan power is restored, with the transfer contact  16  of fan control relay  14  closed upon fixed contact  15 . This causes current to flow from the power source, to fuse/circuit breaker  8 , to fan control relay  14 , to the fan speed control switch  12 , and to the heater fan motor  5 . 
   The after-run heating system may be adapted such that fan control module  3  controls the heater fan motor  5 . Fan control module  3  is connected to vehicle battery  17  via conductor  19 , vehicle battery  17  being further connected to vehicle ground by way of conductor  18 . During normal operation of the vehicle during winter, the existing vehicle heater is supplied with hot engine coolant by way of the engine coolant pump. Heat from the engine coolant is transferred to the passenger compartment by the running of the heater fan motor  5 . Thermostat  26  of fan control module  3  is located in the heater plenum chamber outlet. When heated by the warm air emanating from the heater during normal winter vehicle operation, thermostat  26  closes contacts  27 ,  28 . 
   With contacts  27 ,  28  closed and after-run heating system on/off switch  22  closed, battery power from vehicle battery  17  is supplied to fuse/circuit breaker  20 , to on/off switch  22 , to a connector receptacle  30 , to a connector plug  31 , to plenum air sensing thermostat  26 , to a connector plug  34 , to a connector receptacle  35 , and to the contacts of an ignition-on sensing relay  38 . Ignition-on sensing relay  38  is connected to vehicle ground via conductor  39  and is powered via conductor  40 , which may be connected to any power source that cycles on and off with vehicle ignition. 
   When the vehicle ignition is turned on, power is supplied to relay  38  which causes movable contact  37  to disengage from fixed contact  36 , thereby opening the power supply circuit to fan control relay  14 . When fan control relay  14  is dormant, movable contact  16  is positioned on fixed contact  15 , thereby returning fan control to its original vehicle power source. When vehicle ignition is turned off, battery power is removed from conductor  40  and ignition-on sensing relay  38  becomes dormant, thereby causing contact  37  to reengage contact  36 , transferring battery power to fan control relay  14 , and causing contact  15  to engage with contact  25  via contact  16 . 
   In an alternate embodiment, an after-run heating system may be adapted such that power to heater fan motor  5  may be controlled by fan control module  3 . With on/off switch  22  closed, power is supplied by battery  17  to fuse/circuit breaker  20 , to on/off switch  22 , to fan control relay  14 , to fan speed control switch  12 , and to heater fan motor  5 , thereby placing heater fan motor  5  under the operating control of fan control module  3  and allowing the fan motor  5  to run even with the ignition and engine turned off. 
     FIG. 2  illustrates a circuit diagram of a pump/thermostat and control system therefor, located in the engine compartment and installed as a separated system. Pump control module  2  is generally connected to pump/thermostat module  1 . Vehicle battery  44  is connected to ground via conductor  45 . Vehicle battery  44  provides power to pump control module  2 , to fuse  47 , to connector receptacles at connections at  49  and  56 , to connector receptacle at  58  via conductor  57 , and to a thermostat plug  59  of pump/thermostat module  1 . 
   When the vehicle is driven, the engine pump forces hot engine coolant through the dormant after-run heating system pump  73 . The after-run heating system pump may be generally located in series with the supply hose of the vehicle passenger compartment heater. Thermostat  61  is generally an integral part of the pump/thermostat module  1 . Thermostat  61  senses the heated coolant and is adapted to open or close contacts  62 . For example, thermostat may sense the heated coolant and close contacts  62  upon sensing a temperature of 160° F and opens contacts  62  when coolant temperature is reduced to approximately 95° F. Accordingly, battery power is transferred from the plug  59  to thermostat  61 , to plug  64 , to connector receptacle  65 , and to the contacts  67 ,  68  of ignition-on sensing relay  78 . When the vehicle engine is running, battery power is supplied to ignition-on sensing relay  78 , which thereupon opens fixed contact  67  from engagement with moveable contact  68 . Hot water continues to be supplied to the vehicle heater by way of the engine pump. 
   When the ignition is turned off, battery power is removed from conductor  80 , such that ignition-on sensing relay  78  becomes dormant. Ignition-on sensing relay  78  then closes moveable contact  68  which engages fixed contact  67 , thereby transferring battery power from the thermostat  61 , to ignition-on sensing relay contacts  67 ,  68 , to a connector receptacle  70 , to a plug  71 , to after-run heating system pump  73 , to ground via conductor  74 , plug  75 , connector receptacle  76  and conductor  77 . In this arrangement, the after-run heating system pump  73  commences pumping hot engine coolant to the vehicle passenger compartment heater, thereby effectively substituting the pumping action of the engine pump. This assembly may be used in conjunction with fan control module  3 , which continues heater fan operation as discussed above. Those skilled in the art will appreciate that such interacting assembly allows for the passenger compartment of the vehicle to be heated, even with the engine and ignition turned off. 
   As the after-run heating system continues to operate, thermostat  61  may be adapted to open contacts  62  when the engine coolant drops to a designated temperature, thereby terminating operation of the after-run heating system pump  73 . For example, the thermostat  61  may be adapted to terminate the after-run heating system pump  73  when engine coolant drops to approximately 95° F. In the separated system embodiment of FIG.  1  and  FIG. 2 , the after-run heating system pump  73  ceases to pump cool engine coolant to the passenger compartment heater, which thereupon begins to cool plenum air sensing thermostat  26  located in the heater air plenum. At a designated temperature, plenum air sensing thermostat  26  is adapted to terminate heater fan operation by opening contacts  27 ,  28  such that fan control relay  14  becomes dormant and allows existing vehicle systems to control heater fan motor  5 . With the ignition turned off, the power supply line  7  of the heater fan motor  5  is un-powered such that heater fan motor  5  ceases operation. 
   In view of the foregoing, there is no electrical, mechanical or electromagnetic connection between pump/thermostat module  1  and heater fan module  3 . Therefore, the systems operate independently, but synergistically, to initiate and terminate the heating operation of the existing vehicle heater with the engine turned-off. Those skilled in the art will recognize and appreciate that this elimination of idling allows for the decrease of fuel consumption, air pollution and costs in commercial operations. 
   It will be realized that the heater fan module  3  may be adapted to be turned off, i.e. for seasonal operation, by operating on/off switch  22  of fan control module  3 , which is located in the passenger compartment. Also, pump/thermostat module  1  and control means  2  thereof may be adapted to be turned off through the operation of a seasonal on/off switch  53 . The pump/thermostat module  1  may also be adapted to accommodate automatic termination. For example, an ambient temperature sensor  81  may be substituted for the manual on/off switch  53 . In this case the on/off switch  53  plugs  50 ,  55  are disengaged from connector receptacles  49 ,  56  and replaced by the ambient sensor  81  with its plugs  85 ,  86 . Accordingly, ambient sensor  81  may open or close contacts  82 , thereby terminating or commencing operation of pump/thermostat module  1 . 
     FIG. 3  illustrates the heater fan control module  3  of  FIG. 1  being directly connected to pump/thermostat module  1  of  FIG. 1  as an integrated system. In the directly connected system the plenum air sensing thermostat  26  and pump control module  2  are disconnected and removed from the system. 
   In this configuration and during normal vehicle operation (engine running), fan control module  3  operates as follows: with system on/off switch  22  open and ignition on, the after-run heating system is disconnected from battery  17  and remains non-operational when the engine is turned off. Fan control relay  14  is also unpowered with transfer contact  16  being closed upon contact  15 . Instead, the normal power source through line  7  provides power to heating fan motor  5 , which is connected to fuse/circuit breaker  8 , to fan control relay  14 , and to fan speed control switch  12 , thus providing air movement means for the passenger cabin. 
   With the ignition and engine turned off, battery  17  supplies power to fan control module  3 , which is connected to fuse/circuit breaker  20  and on/off switch  22 . Without battery power, the pump/thermostat module  1  is unpowered and after-run heating system pump  73  is dormant. If required while the vehicle is being driven, vehicle interior heating may be provided by the engine pump circulating engine coolant through the dormant after-run heating system pump  73  located in series with the hose supplying hot engine coolant to the vehicle heater. The flow of hot coolant also heats thermostat  61 , thereby closing contacts  62 . When engine (ignition) is turned off, the after-run heating system does not operate because on/off switch  22  remains open. The on/off switch  22  may be turned on or off at any time during vehicle operation. With on/off switch  22  turned on when engine is turned off, the after-run heating system is adapted to automatically pump hot engine coolant. 
   When the engine is turned off and on/off switch  22  and thermostat  61  are closed, the system operates as follows: power is transferred from battery  17  to fuse/circuit breaker  20 , to on/off switch  22 , to the connector receptacle  30 , to plug  59 , to closed contacts  62  of thermostat  61 , to plug  64 , to connector receptacle  35 , and to the contacts  36 ,  37  of the ignition-on sensing relay  38 . With the ignition turned off, ignition-on sensing relay  38  does not receive power from conductor  40 . Therefore, upon transfer contact  37  being closed upon engagement with fixed contact  36 , power is transferred at conductors  90  and  42 . 
   In this arrangement, power is transferred from battery  17  from conductor  90  to after-run heating system pump  73 , to continue circulation of hot water to vehicle heater with the engine turned off. At the same time, power is transferred from battery  17  to fan control relay  14 , through closed on/off switch  22 , and fuse/circuit breaker  20 . Conductor  11 , being connected to transfer contact  16  of fan control relay  14 , it powers heating fan motor  5  by way of fan speed control switch  12 , thereby causing heating fan motor  5  to run in conjunction with after-run heating system pump  73 . This assembly allows for passenger compartment to be heated even with the engine turned off. 
   As the after-run heating system continues to operate, the thermostat  61  may be adapted to open contacts  62  when the engine coolant reaches a designated temperature, thereby terminating operation of the after-run heating system pump  73 . For example, the time thermostat  61  may be adapted to terminate the after-run heating system pump  73  when it drops to approximately 95° F. In one embodiment, time thermostat  61  is adapted to interrupt battery power to after-run system pump  73  and fan control relay  14 , thereby placing both in a state of dormancy and transferring contact  16  to re-engage with contact  15 . This engagement returns the heater fan motor  5  to be controlled and powered by the original control power sources. 
   Heater fan module  3  may also be adapted to be turned off, i.e. for seasonal operation, by operating on/off switch  22  of fan control module  3 , which is located in the passenger compartment. 
   An alternate method for connection to heating fan motor  5  is shown in  FIG. 4. A  conductor  91  is connected to transfer contacts  16  of fan control module  3  and fan control relay  14  by replacing conductor  11  in either  FIG. 1  or  3 . The other end of conductor  91  is connected to existing vehicle heater relay  92  at the relay&#39;s positive terminal  93 . This arrangement is adapted such that power is transferred to relay  92  when after-run heating system is turned on and vehicle ignition switch  96  is turned off. This arrangement is further adapted such that when vehicle ignition switch  96  is turned on, power from the battery  17  is transferred to existing heating relay  92  and contacts  98 ,  99  are closed. Upon closure of contacts  98 ,  99 , power is supplied from existing fuse/circuit breaker  8 , to vehicle heater relay  92 , contacts  98 ,  99 , to fan speed control  12 , and to heating fan motor  5 . 
   When either the vehicle ignition switch  96  or after-run heating system are turned off, power to vehicle heater relay  92  is interrupted, thereby opening contacts  98 ,  99  and interrupting power to the heating fan motor  5 . Thus, with the after-run heating system on and hot engine coolant present in the engine cooling system, cycling of vehicle ignition switch  96  alternately on and off puts heating fan motor  5  under the control of either the after-run heating system or original vehicle control. 
   While this invention has been described with reference to certain illustrative aspects, it will be understood that this description shall not be construed in a limiting sense. Rather, various changes and modifications can be made to the illustrative embodiments without departing from the true spirit and scope of the invention, as defined by the following claims. For example, the temperature settings of the referenced thermostats could be other than those indicated. Also, the various components shown as mechanical sensors, circuit breakers, and electromagnetic relays could have electronic equivalents substituted therefor. A battery voltage monitor or timing device could also be placed in circuit to terminate system operation upon encountering low battery voltage or after a designated time period. An auxiliary battery or multiple vehicle batteries connected in parallel or with battery isolators for supplying power only to the after-run heating system from only one of the group of batteries, while being capable of being charged by the vehicle engine alternator, are all also contemplated. The locations of the plugs and connectors could be reversed, i.e., the module shown having a receptacle could have a plug and the mating module would have a receptacle instead of the plug as shown. Also, it will be understood that the plugs and receptacles could be at the ends of wires having a length suitable for the particular needs of a specific installation. 
   Furthermore, it will be appreciated that any such changes and modifications will be recognized by those skilled in the art as an equivalent to one or more elements of the following claims, and shall be covered by such claims to the fullest extent permitted by law.