Abstract:
A truck has a cab, a body, an engine, and an exhaust system. The body carries loads during use and each of its panels has an interior fluidly connected to one another. The exhaust system receives exhaust from the engine which flows thru exhaust pipes into a muffler and then into a diverter box. When desired, the diverter box diverts at least a portion of the exhaust air into an air outlet that directs air to the interiors of the panels to heat the body during use. Any remaining portion of the exhaust air, is exhausted directly to ambient air. A circuit controls the flow of exhaust gases to the truck body utilizing a diverter, an actuator for controlling the diverter, and a temperature sensor for controlling the actuator wherein a flow of exhaust gases to the truck body is shut off when said temperature sensor senses an exhaust gas temperature above a predetermined level. Alternatively, a signal indicating the start of a regeneration cycle of a diesel particulate filter can be used to control the actuator.

Description:
[0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/013,420, the disclosure of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to controlled heating of truck bodies, especially dump truck bodies, to maintain high temperatures of hot loads, especially asphalt, and/or to prevent any loads from freezing or sticking during cold weather hauling. 
       BACKGROUND OF THE INVENTION 
       [0003]    The art of hauling and dumping loads with trucks has long been known. Unfortunately, so too has the problem of loads freezing and sticking during cold weather hauling. Thus, a variety of mechanisms have been introduced in the prior art to alleviate or lessen the problem. Yet all solutions can now be improved upon for one reason or another. 
         [0004]    For example, many prior art references teach the diversion or siphoning of engine exhaust gasses to the truck body for heating a load therein. Specifically, U.S. Pat. No. 1,942,207 (R. Ferwerda) teaches replacing a muffler of an exhaust pipe with conduits and diverting exhaust gasses into an underside of a truck body or cargo bed. In U.S. Pat. No. 2,275,622 (L. E. Gatien), a trailer body becomes heated by siphoning a portion of the exhaust gasses from an exhaust pipe. In U.S. Pat. No. 3,472,548 (S. Comisac), a dump truck body becomes heated by diverting exhaust gasses from an exhaust pipe into exhaust outlets of a truck body floor. Similarly, U.S. Pat. No. 3,499,678 (M. M. Richler) teaches diversion of exhaust gas into longitudinal duct members that extend underneath a floor of a truck body. More recently, U.S. Pat. No. 5,797,656 (Kauk et al.) teaches diversion of exhaust gasses by means of a controllable diverter member positioned in first and second blocking position wherein gas becomes directed to either the truck bed or the truck muffler, but not both. 
         [0005]    A recent change in the law concerning the allowable emissions of unburned particulates, or soot, from diesel engines has given rise to new technology for removing unburned particulates from the exhaust stream of such trucks. Most new trucks have a diesel particulate filter, or DPF, to accomplish this task. As the DPF accumulates soot, it eventually becomes clogged. Thus, most DPF&#39;s are equipped with a means of burning the soot in a process called regeneration. During the regeneration process, exhaust temperatures can be elevated considerably higher than is typical during normal operation. In these instances, the higher temperatures can damage the body by burning paint, weakening or melting aluminum, or igniting the load when the exhaust stream is diverted to the dump body during regeneration. Accordingly, a need exists for simply and economically controlling the flow of the exhaust stream, into the truck body to avoid damage to the body caused by high temperatures associated with the DPF and/or operator error and to alert the driver of high temperature situations. 
       SUMMARY OF THE INVENTION 
       [0006]    The above-mentioned and other problems become solved by applying the principles and teachings associated with the hereinafter described heated truck body, especially a dump truck body. 
         [0007]    In one embodiment, the truck has a cab, a body, an engine, and an exhaust system. The body, defined by a floor and front, rear and sidewall panels, carries loads during use and each of the panels has an interior fluidly connected to one another. The exhaust system receives exhaust from the engine which flows thru exhaust pipes into a muffler as is known in the art and then into a diverter box. When desired, the diverter box diverts at least a portion of the exhaust air into an air outlet that directs air to the interiors of the panels to heat the body during use. Any remaining portion of the exhaust air is exhausted directly to ambient air. 
         [0008]    Preferably, the air outlet fluidly connects to the interior of the front panel wherein air is directed in generally opposite directions therein. In turn, air flows from the front panel to the interiors of the sidewall panels and is exhausted to ambient air near the rear of the side panels. More preferably, the air flows through the interior of the panels in a vicinity near the floor and, occurs for substantially the entirety of the length of the front and sidewall panels. In other embodiments, air is introduced into the body at any location around the body panels and travels around the panels. A temperature sensor may mount to the body along one or more of the panels to provide an indication of air temperature in the body or the temperature of the body. 
         [0009]    In other aspects of the invention, a control panel resides within the cab and monitors exhaust temperatures at the dump body. A control circuit further operates to automatically shut down exhaust flow to the dump body when temperatures are elevated during the regeneration process associated with diesel particulate filters and when the power take-off (PTO) or driveshaft is engaged. The heating system can further be manually turned on and off from the in-cab control panel. The control panel may also include a visual indicator for indicating temperature and/or a power on/off condition. The control panel receives its power from the battery. 
         [0010]    Finally, methods for heating a truck are also disclosed. In one embodiment, the method recites providing a control circuit for selectively directing heated air from an exhaust system into an interior of a truck body panel; flowing the air from the interior of the panel to the interior of the remaining panels; and exhausting the air along a rear portion of the side panels. 
         [0011]    These and other embodiments, aspects, advantages and features of the present invention will be set forth in the description which follows, and in part will become apparent to those of ordinary skill in the art by reference to the following description of the invention and referenced drawings or by practice of the invention. The aspects, advantages, and features of the invention are realized and attained by means of the instrumentalities, procedures, and combinations particularly pointed out in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and together with the description serve to explain certain principles of the invention. In the drawings: 
           [0013]      FIG. 1  is a side diagrammatic view in accordance with the teachings of the present invention of a heated truck body; 
           [0014]      FIG. 2  is a perspective view in accordance with the teachings of the present invention of a truck body with a heated air flow diagram superimposed thereon; 
           [0015]      FIG. 3  is a partial cross sectional view in accordance with the teachings of the present invention of a truck body with a heated air flow diagram superimposed thereon; 
           [0016]      FIG. 4  is a partial view in accordance with the teachings of the present invention of a diverter box positioned along an exhaust system in a closed position directing engine exhaust through an exhaust pipe; 
           [0017]      FIG. 5  is a partial view in accordance with the teachings of the present invention of a diverter box positioned in an exhaust pipe in an open position directing at least a portion of the engine exhaust through a body for heating the body; 
           [0018]      FIG. 6  is a schematic diagram in accordance with the teachings of the present invention of an electrical circuit for controlling the operation of the diverter and the diversion of engine exhaust between an exhaust pipe and a body; and 
           [0019]      FIG. 7  is a partial view in accordance with the teachings of the present invention of a diverter box positioned adjacent an exhaust pipe in a closed position directing engine exhaust through an exhaust pipe and, in phantom, an open position directing engine exhaust at least partially through a body for heating the body. 
       
    
    
       [0020]    Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0021]    In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that process or other changes may be made without departing from the scope of the present invention. The following detailed, description is, therefore, not to be taken in a limiting sense and the scope of the present invention is defined only by the appended claims and their equivalents. In accordance therewith, a simple and economic heated truck body design that heats the dump body and protects the dump body against overheating by monitoring the status of the diesel particulate filter, is hereinafter described. 
         [0022]    With reference to  FIG. 1 , a truck  10  generally has a cab  12  and a cargo bed or body  14 , especially a dump body, mounted to a common frame or chassis  16 . A cylinder  18 , preferably hydraulic, telescopically presses between the chassis and an underside  20  of the body to raise or lower the body for dumping operations as is well known in the art. An engine  22 , connected to both a battery  24  and a fuel tank  26 , supplies the requisite power for operation of the truck and its components, i.e., the dump body, and is also well known in the art. An electric starter, not shown, typically resides within the cab  12  and electrically interconnects the battery  24  with the engine  22  to allow an operator on/off engine control. 
         [0023]    In accordance with the present invention, an air outlet  28  mates with a corresponding air inlet  30  on the underside  20  of the dump body  14  and creates a fluid coupling for air, preferably heated exhaust air, to exit the engine  22  and diesel particulate filter  32  and flow into and enter the body  14  whenever the body mates with the chassis  16 . In this manner, the heated truck body  14  can obtain increased temperatures relative to unheated truck bodies. 
         [0024]    Exhaust air is directed through and around the dump body  14  in any configuration as known in the art. In the present preferred embodiment, the air flow pattern for heating a truck body  14  includes exhaust air leaving the engine  22  along exhaust pipe  34  and through diesel particulate filter  32 . A muffler (not shown) may be positioned between the engine  22  and the diverter box  36  as is known in the art. When directed into the dump body  14  through diverter box  36 , the air travels through coupled air outlet  28  and air inlet  30 , and opening  38  into a radius or air flow conduit  40 . The air flow conduit  40  in this embodiment is generally triangular in shape and is formed by the floor  50 , front panel  52 , and a radius wall  62 . In heated bodies and unheated bodies alike, radius walls are commonly utilized to reduce hang up of material during dumping. Once in the conduit  40 , the air flow naturally divides and flows in generally opposite directions shown by arrows  42 ,  44  toward sidewall panels  46  and  48 . 
         [0025]    In one embodiment, the air travels along a surface of the floor  50  or within an interior of the floor as will be later described. In other embodiments, the air travels underneath the body in air flow conduits within the chassis. In any embodiment, once the air reaches air flow conduit  40  positioned along the front panel  52 , it naturally divides in some ratio and travels in directions  42 ,  44  essentially opposite one another. Thereafter, the air reaches the sidewall panels  46  and  48  and turns in directions shown by arrows  54  and  56 , respectively, generally toward a rear panel  58 . Finally, when the air reaches a rearward portion of the sidewall panels  46  and  48 , the air is exhausted into ambient air through openings  60  positioned on either side of the dump body  14 . A representative opening  60  is shown in  FIG. 1  adjacent the rearward portion of sidewall panel  46 . 
         [0026]    Appreciating that if the front and sidewall panels join one another at nearly perpendicular corners, the air flow path can become tortuous. The dump body may include various additional gradual-turn connectors or non-perpendicular corner designs to minimize any adverse affects. 
         [0027]    With reference to  FIG. 3 , skilled artisans will appreciate that many industry dump body floors and/or front, rear and sidewall panels actually comprise multiple wall designs such as substantially parallel interior and exterior walls  62 ,  64  defining an interior  66  having slats (not shown) or other structural support members therein. As such, one air-flow embodiment of the present invention takes advantage of such panel design and causes airflow throughout the truck body  14  to occur within the interiors  66  of the front, sidewall and/or rear panels. As shown, air flows in a first-direction  68  (indicated as an arrow tip pointed out of the paper) within an interior of a first sidewall and flows in a second direction  70  (indicated as an arrow end directed into the paper) within an interior of a second sidewall and both occur along a lower portion  82  of the panel in the vicinity of the floor  50 . Alternatively, air flow occurs within the panels along upper portions  84  or mid-portions  86  of the panels in addition to or as a supplement to air flow occurring near the lower portions  82  of the panels. 
         [0028]    As briefly noted above and shown in  FIG. 1 , a diesel particulate filter  32  for removing unburned particulates from the exhaust stream is positioned in the exhaust stream between the engine  22  and an exhaust pipe or outlet  38 . Diesel particulate filters are known in the art for removing diesel particulate matter or soot from the exhaust gas of a diesel engine. Although some filters are single use, i.e., disposable, others are designed to burn off the accumulated particulate, either through the use of a catalyst, or through an active technology, such as a fuel burner which heats the filter to soot combustion temperatures, through engine modifications (e.g., the engine is set to run a certain specific way when the filter load reaches a pre-determined level, either to heat the exhaust gases, or to produce high amounts of NO 2 , which will oxidize the particulates at relatively low temperatures), or through other methods. These processes are commonly referred to as regeneration. During the regeneration process, exhaust temperatures can be elevated considerably higher than temperatures during normal operation. 
         [0029]    In accordance with the present invention, a diverter box  36  is positioned in or adjacent to an exhaust pipe  92  of the truck  10  as shown in  FIG. 4 . Inside the diverter box  36  is a diverter  94 , or flapper, that pivots about a shaft  96 , and is attached to an actuating arm  98 . The actuating arm or lever  98  is moved in one direction or the other by an air cylinder  100  or the like. In  FIG. 4 , the diverter  94  is shown in a closed position, covering an outlet pipe  102  to the body  14  so that all the exhaust gases generated by the engine  22  (shown by directional arrow  104 ) are directed through the exhaust pipe  92  (shown by directional arrow  106 ) to exhaust outlet  90 . 
         [0030]    In  FIG. 5 , the diverter  94  is shown in an open position, at least partially uncovering, the outlet pipe  102  to the body  14 , so that exhaust gases generated by the engine  22  (shown by directional arrow  104 ) are directed through both the exhaust pipe  92  (shown by directional arrow  106 ) and the outlet pipe  102  (shown by directional arrow  108 ) to the body  14 . The air cylinder  100  in the present preferred embodiment is single acting, with a spring return. In other words, when air is supplied through air line  110 , the air cylinder  100  is extended to open the diverter  94 . This motion also compresses a spring  112 . When the air supply is removed, and air is allowed to escape from the air cylinder  100 , the spring  112  forces the air cylinder and diverter  94  to the closed position as shown in  FIG. 4 . This is a fail safe arrangement, meaning that if something goes wrong with the controls, including a leaking air line for example, the diverter  94  will automatically return to the safe, or closed position in order to avoid damaging the body. 
         [0031]    As shown in the schematic diagram of  FIG. 6 , the air cylinder  100  is controlled by an air solenoid valve  114 . When the solenoid on this air solenoid valve  114  is electrically activated, the valve supplies air to the air cylinder  100 . The air solenoid valve  114  is also designed to operate in a fail safe manner because it exhausts air if there is a loss of current to the solenoid valve  114 . An indicator light  116  is energized by the same electrical control circuit  117  as the air solenoid valve  114 . This indicator light  116  is in view of the operator in the cab, and is lit any time that the diverter  94  is open, sending heated exhaust gases to the body  14 . 
         [0032]    The electrical control circuit or controller  17  is likewise positioned in the cab and is designed to close the diverter  94  under three circumstances: (1) when the operator manually activates a control/off switch  118 ; (2) when the power take-off or PTO is engaged which occurs any time the body  14  is being raised for dumping; and (3) whenever a temperature switch  120  is engaged. This temperature switch  120  may operate directly or through the controller  117 , and may be set at a single temperature or be adjustable. The electrical circuit is also designed to require the operator to manually re-start the flow of exhaust to the body  14  after any time the diverter box  36  is closed. 
         [0033]    The electrical circuit shown in  FIG. 6  consists of a PTO switch  122 , temperature switch  120 , control switch  118 , battery or power supply  24 , fuse  124 , and two relays  126  and  128 . The power supply may be provided by the battery  24  or elsewhere within the truck&#39;s electrical circuit. In operation, power is always supplied to one of the connections  130  on the control switch  118 , to the high-voltage input  132  of relay  126 , and to the low-voltage, or coil, input  134  of relay  128 . When the momentary on switch  118  is activated, power is also supplied to the low-voltage, or coil, input  136  of relay  126 . This causes a connection to be completed on the high side of relay  126 , supplying power at Normally Open output  138 . This supplies power to the air solenoid valve  114 , and also to the Normally Closed output  140  of relay  128 . Relay  128  is not activated at this time, so the Normally Closed output  140  is connected to the high side input  142  of relay  128 . This supplies power to the low-side input  136  of relay  126 . 
         [0034]    When the momentary on switch  118  is released, power supply to the air solenoid valve  114  is maintained through the path: Power supply  24  to fuse  124  to high side input  132  of relay  126  to high side output  138  of relay  126  to Normally Closed output  140  of relay  128  to high side input  142  of relay  128  to low side input  136  of relay  126  to ground. This circuit is broken by activating relay  128 , which is done by completing a ground to the coil side  144 . This completion of ground can be done by any one of the three switches: PTO switch  122 , Temperature switch  120 , or control switch  118 . Therefore and in accordance with the present preferred embodiment, if the diverter  94  is closed due to the temperature switch  120  sensing an elevated exhaust gas temperature for example, as the temperature goes down, the diverter does not automatically open, but needs the operator to re-activate the control switch  118 . In an alternative embodiment, the temperature switch  120  could be replaced by a signal from the truck that controls the start of regeneration of the diesel particulate filter. 
         [0035]    With reference to  FIG. 7 , skilled artisans will appreciate that the diverter box  36  can be positioned in many varying positions along the exhaust system and/or adjacent the exhaust system. For example, the diverter box  36  could be positioned in the outlet pipe  102  between the exhaust system and the truck body  14 . In this embodiment, exhaust gases generated by the engine  22  (shown by directional arrow  104 ) are directed through the exhaust pipe  92  (shown by directional arrow  106 ) when the diverter  94  is in a closed position as shown. When the diverter  94  is in an open position (shown in phantom), exhaust gases generated by the engine  22  (shown by directional arrow  104 ) are directed through both the exhaust pipe  92  (shown by directional arrow  106 ) and the outlet pipe  102  (shown by directional arrow  108 ) to the body  14 . Again, the diverter  94  and air cylinder  100  are utilized in a fail safe arrangement that will automatically return to the safe, or closed position in order to avoid damaging the body in unsafe conditions cause by the regeneration process. 
         [0036]    Lastly, the invention contemplates interchangeability with other types of truck bodies other than the dump body shown. For example, the teachings herein apply equally to stationary-bed trucks, cement mixers, cargo trailers or any other trucks that haul loads requiring heat. 
         [0037]    The foregoing description is presented for purposes of illustration and description of the various aspects of the invention. The descriptions are not intended to be exhaustive or to limit the invention to the precise form disclosed. The embodiments described above were chosen to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.