Abstract:
A roof heating system for opposing buildup of ice and snow on the roof of a large wheeled vehicle, such as a tractor drawn trailer. The system may comprise a fluid circulation system for transferring heat to the roof, including a first heat exchanger for obtaining heat from the exhaust system of the vehicle or alternatively, a tow vehicle, a second heat exchanger for delivering heat to the roof of the protected vehicle, and a powered system for circulating fluid from the first heat exchanger to the second heat exchanger. The system may comprise an electric motor driven pump to achieve circulation, a battery to power the electric motor of the pump, a recharging system for recharging the battery, and a switch to initiate system operation. The recharging system may be adapted to utilize AC power.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to large wheeled vehicles, and more particularly to a heating system for heating the roof of a vehicle, to prevent buildup of ice and snow. 
       BACKGROUND OF THE INVENTION 
       [0002]    Large vehicles, such as tractor drawn trailers, trucks, and busses are widely used to transport goods and bulk commodities across the United States. Large vehicles are typically kept outdoors both when transporting goods or people and also when parked or in staging areas. There exists great potential for ice and snow to accumulate on the roofs of large vehicles in inclement weather. 
         [0003]    While small incidental buildup of ice and snow seems to present little if any problem, there exists the possibility that significantly large and heavy sections of ice and snow will become dislodged and fall from the vehicle roof. This may present significant safety hazards, particularly at highway speeds, as falling pieces of ice and the like may strike the windshield of a nearby vehicle, may momentarily distract other drivers, or may even cause a hazardous condition in that the surface of the roadway may become littered with pieces of ice which might impede braking by other vehicles. 
         [0004]    It is difficult at best for the operator of a large vehicle to monitor the roof for presence of ice and snow buildup. It is even more difficult to remove such ice and snow if detected, in vehicles wherein the roof surfaces are beyond convenient reach of a person on the ground or in the cabin of a tow vehicle. 
         [0005]    There exists a need for a system which can be activated to minimize buildup of ice and snow on the roof of a large vehicle to overcome the hazard noted above. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a system for removing ice from the roof of a large vehicle, such as a truck, bus, or tractor drawn trailer. The system provides a heated medium which is disposed in heat exchange relation to the roof of a large vehicle such that ice and snow formations can be melted before becoming so large as to present the hazard noted above. 
         [0007]    The system may utilize a suitable fluid such as coolant comprising water combined with a freeze point depressant and boiling point extender, and may include a heat exchange arrangement to heat this fluid from waste engine heat. The source of waste engine heat may be the exhaust system of the tow vehicle. 
         [0008]    The system may include a circulating pump adapted to circulate the coolant, to assure that enough of heat is present to accomplish the goals of the invention. The system may include a battery to power the circulating pump, recharging apparatus to recharge the battery, and a switch to initiate operation. 
         [0009]    It is an object of the invention to provide a system for overcoming buildup of ice and snow on the roof of a large vehicle by heating the roof. 
         [0010]    Another object of the invention is to utilize otherwise wasted heat from vehicle operation. 
         [0011]    It is an object of the invention to provide improved elements and arrangements thereof by apparatus for the purposes described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes. 
         [0012]    These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
           [0014]      FIG. 1  is a side view of a tractor and trailer combination according to at least one aspect of the invention. 
           [0015]      FIG. 2  is a top view of the tractor and trailer combination of  FIG. 1 . 
           [0016]      FIG. 3  is a diagrammatic view of a fluid circulation circuit provided in the tractor and trailer combination of  FIG. 1 . 
           [0017]      FIG. 4  is an electrical schematic showing electrical components for operating the fluid circulation circuit of  FIG. 3 . 
           [0018]      FIG. 5  shows some optional electrical components which may be added to those depicted in  FIG. 4 . 
           [0019]      FIG. 6  is an enlarged top detail view of a heat exchanger seen at the right of  FIG. 3 . 
           [0020]      FIG. 7  is a front perspective view of an exemplary housing containing the components shown in  FIG. 5  and also other components of a system including a fluid circulation circuit according to at least one aspect of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    Referring first to  FIG. 1 , according to at least one aspect of the invention, there is seen a tractor and trailer combination  10  protected from formation of ice (not shown) on the roof  12  of the trailer  14 . The trailer  14  may be for example a conventional road going freight trailer which is drawn by a tractor  16 . The tractor  16  may be of generally conventional type having a drive train (not separately shown) which is disposed to propel the tractor  16  along a roadway (not shown). The drive train will be understood to comprise an internal combustion engine including an exhaust system, which in turn further comprises an exhaust conduit  19  for discharging engine exhaust to the atmosphere. The trailer  14  may be of the type which is selectively coupled to the tractor  16  for draft transport and decoupled from the tractor  16 . The above description summarizes certain components of typical conventional truck and tractor combinations. 
         [0022]    The tractor and trailer combination  10  is improved by incorporation of a system for heating the roof  12  of the trailer  12  so as to oppose accumulation of ice and snow on the roof  12 . Any snow or ice falling or forming on the roof  12  may be discharged from the roof  12  as water (not shown) after melting. The system for heating the roof  12  may comprise a first heat exchanger  18  disposed to provide heat to the roof  12  of the trailer  14  and an associated second heat exchanger  20  disposed to obtain waste heat from the internal combustion engine. 
         [0023]    The first heat exchanger  18  may take any convenient form. In an unillustrated example, the first heat exchanger  18  may comprise a grid or other generally flat or planar layout of tubing such as plastic tubing, covered by an aluminum plate or plates. The aluminum plates may serve both to protect the plastic tubing and also to conduct heat from the plastic tubing to the entire area of the roof  12  of the trailer  14 . 
         [0024]    The first heat exchanger  18  and the second heat exchanger  20  are connected to one another by a fluid circulation circuit comprising a working fluid contained therein. The working fluid, which may be a mixture of water and conventional engine antifreeze product such as those comprising polyethylene or polypropylene glycol, and which are commercially available to the general public, is, disposed to obtain heat from the second heat exchanger  20  and deliver the heat to the first heat exchanger  18 . 
         [0025]    To this end, the fluid circulation circuit will be understood to comprise a fluid conduit  22  forming a closed loop extending between the first heat exchanger  18  and the second heat exchanger  20 . The fluid conduit  22  will be understood to include all necessary apparatus to achieve operation as described, for example, including both supply and return legs, drain valves, and connectors including stationary connectors mounted to the trailer so that the fluid circulation circuit may be formed from separate sections of tubing (none of these is specifically shown). Referring also to  FIG. 3 , a pump  24  which is disposed serially within the closed loop of the fluid circulation circuit is disposed to pump the working fluid throughout the fluid conduit. Description of the fluid circulation circuit as forming a closed loop signifies that the fluid conduit  22  and fluid passages formed in the first heat exchanger  18  and the second heat exchanger  20  cooperate to provide an endless, repeating flow path so that the working fluid flows through repeating heat gain and heat loss cycles, and is not lost from the fluid circulation circuit. An expansion feature (not shown) may be provided to accommodate variation in fluid volume with changing temperatures, but would be incidental to operation for moving heat as described herein. 
         [0026]    Referring also to  FIG. 4 , the system for heating the roof  12  comprises an electrical system disposed to operate the pump  24 . The electrical system may comprise an electric motor  26  disposed to drive the pump  24  in any suitable way, a battery  28  disposed to provide operating power to the electric motor  26 , conductors  30  forming a circuit enabling operation of the pump  24  using power from the battery  28 , and a switch  32  which is disposed to open and close the circuit of the electrical system to initiate and stop operation of the pump  24 . The conductors  30  will be understood to include ancillary apparatus such as connectors, circuit protective devices such as fuses, fuse clips, circuit breakers, indicating lights, and others (none shown) deemed advisable to provide in light of accepted practice in vehicular electrical systems, even if not explicitly described. 
         [0027]    The switch  32  is shown in representative capacity only. The switch  32  may comprise a manual switch located at the trailer  14  or in the tractor  16 . The switch may comprise a single device such as a pushbutton or a knife-blade switch, or may comprise a wireless link and remotely operated switching elements. For example, it would be possible to locate a manually operated wireless signal transmitter in the tractor  16  in a location convenient to a driver, with a corresponding signal responsive relay located at the trailer  14 , such that the actual switching function is remotely actuated (this option is not shown). 
         [0028]    In one implementation of the invention, the pump  24  and its motor  26 , and the battery  28  are carried on the trailer  14 . More specifically, the pump  24 , the motor  26 , and the battery  28  may be housed within a weather resistant enclosure  33  disposed on the trailer  14 , at a front wall  34  thereof for example. The weather resistant enclosure  33  may have hinged doors  35 A,  35 B affording access to internal components, as described hereinafter. Of course, liquid handling apparatus such as connectors, drain valves, and manifolds may be provided within the weather resistant enclosure  33 , as seen in a representative exemplary layout of  FIG. 7 . Manifolds, where provided, may be employed to divide flow from a singular tube or conduit into branches, such as to enable parallel fluid subcircuits to distribute heat to the roof  12  if desired, rather than having the fluid circulation circuits occur as a single undivided loop (parallel fluid subcircuits are not shown). 
         [0029]    In a currently preferred implementation of the invention, the first heat exchanger  18 , the pump  24 , and the battery  28  are carried on the trailer, with the second heat exchanger  20  carried on the tractor  16 , wherein the second heat exchanger  20  is coupled to the exhaust conduit  19  of the exhaust system of the internal combustion system of the tractor  16 . 
         [0030]    The second heat exchanger  20  may be readily installable on and readily removable from the exhaust conduit  19  of the exhaust system of the internal combustion engine. Description of the second heat exchanger  20  as being readily installable on and readily removable from signifies that installation and removal may be accomplished by hand or using only hand tools (not shown). For example, and referring momentarily to  FIG. 6 , the body  36  of the heat exchanger  20  may comprise an arcuate member or arcuate surface  38  which is dimensioned and configured to fit in close cooperation with a corresponding outer surface  40  of the exhaust conduit  19  of the exhaust system of the internal combustion engine. The heat exchanger  20  may comprise a coupling strap  42  which together with the second heat exchanger  20  encircles the exhaust conduit  19  of the exhaust system of the internal combustion engine, and clamps the second heat exchanger  20  to the exhaust conduit  19  of the exhaust system of the internal combustion engine. 
         [0031]    The strap  42  may be secured in place by passing screws  44 ,  46  through respective brackets  48 ,  50  which engage the ends of the strap  42 , and by threading the screws  44 ,  46  to threaded holes (not shown) formed in the body  36  of the second heat exchanger  20 . Removal may be performed in reverse order of installation. If installation and removal can be done using screwdrivers, hand wrenches, or other manual tools, then the heat exchanger  20  may be said to be readily installed on and removed from the exhaust conduit  19 . 
         [0032]    The fluid circulation circuit described above is a dedicated circuit supplying only the first heat exchanger  18  with heat. It would be possible to modify the fluid circulation circuit such that other purposes are provided with heat. For example, the interior of the trailer  14  could be fully or partially heated using the fluid circulation circuit (this option is not shown). 
         [0033]    Not only does the fluid circulation circuit obtain waste heat from the internal combustion engine of the tractor  16 , notably from the exhaust system, but heat supplied to the working fluid is obtained exclusively from the exhaust system of the internal combustion system. If desired, the exhaust could be supplemented by other waste heat sources. Illustratively, engine coolant, engine lubricant, and transmission fluid could be used as sources of otherwise wasted heat (these options are not shown). 
         [0034]    Because the tractor and trailer combination  10  includes a pivot joint, for example, as provided by the fifth wheel, that portion of the fluid circulation circuit connected directly to the second heat exchanger  20  may comprise flexible conduits. Thus, relative motion between the tractor  16  and the trailer  16 , such as steering but also bumps and other vertical road displacements, are accommodated by the fluid circulation circuit without destructive consequences which might arise from the use of rigid fluid conduits. With the weather resistant enclosure  33  located on the front wall  34   s  of the trailer  14 , the legs of the fluid circulation circuit extending to the heat exchanger  20 , which are preferably flexible, may be conveniently limited in length. 
         [0035]    Turning now to  FIG. 5 , the electrical system, such as that shown in  FIG. 4 , may comprise a battery recharging arrangement disposed to enable recharging of the battery  28 . Although power may be obtained entirely or in part from the DC electrical system of the tractor  16  if desired, the battery recharging arrangement may comprise a power converter  52  disposed to enable recharging the battery  28  from an alternating current source. AC power is typically readily available at truck stop facilities (not shown). Hence the electrical system may comprise a power port  54  which is configured to be matingly compatible with 120V AC power plugs or other connectors. The power converter  52  and the power port  54  may be disposed within the weather resistant enclosure  33 , as shown in  FIG. 7 . 
         [0036]    Thus far, description of the invention has been set forth in terms of trailers drawn by tractors, such as the tractor and trailer combination  10 . However, the principles of the invention may have further ranging applications. The novel system for opposing formation of ice on the roof may apply to vehicles other than trailers. Any large wheeled vehicle which is ultimately propelled by an internal combustion engine may enjoy the benefits of the present invention. For example, trucks having cabs and large bodies on a single unarticulated chassis, busses, and still other vehicles may incorporate a system according to the present invention. As employed herein, ultimate propulsion signifies that the wheeled vehicle the roof of which is protected from ice according to the invention may carry thereaboard its own internal combustion engine, or may be a draft vehicle such that the internal combustion engine providing propulsive power is carried aboard a tow vehicle. 
         [0037]    According to one aspect, the invention may be regarded a system for opposing formation of ice on the roof of a wheeled vehicle such as the trailer  14 . Such a system may be considered to comprise a first heat exchanger such as the heat exchanger  18  disposed to provide heat to the roof of the protected vehicle, a second heat exchanger such as the heat exchanger  20 , if disposed to obtain waste heat from the internal combustion engine, a fluid circulation circuit such as the fluid circulation circuit comprising the fluid conduit  22 , with or without a working fluid present, a pump disposed to pump working fluid throughout the fluid conduit, and an electrical system such as that described hereinabove, including a battery disposed to provide operating power to the pump, and a switch disposed to open and close the circuit to initiate and stop operation of the pump. 
         [0038]    While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is to be understood that the present invention is not to be limited to the disclosed arrangements, but is intended to cover various arrangements which are included within the spirit and scope of the broadest possible interpretation of the appended claims so as to encompass all modifications and equivalent arrangements which are possible.