Abstract:
A solar energy-assisted patch cart with a support surface for carrying and heating bituminous materials, a heating source located adjacent to the support surface, and a battery powered at least in part by solar energy for igniting a burner associated with the heating source. Preferably, a charge controller is used to maintain the battery with a predetermined level of charge. The solar energy may be supplied by one or more retractable solar panels in electric communication with the battery.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to the field of patch carts used for patching roadways. More specifically, the invention is directed to a solar power-assisted patch cart.  
         [0002]     Generally, patch carts are used by towns, cities, municipalities, counties, or states to repair local roadways, highways or parking lot facilities, for example. In addition, private entities may use these patch carts to repair roadways or facilities. Patch carts include an enclosure for storing bituminous material such as asphalt used for road repair. The enclosure and bituminous material are heated, and then selectively dropped onto a repair area, such as by release from the bottom portion of a funnel-shaped patch cart, or by shoveling. Suitable patch carts which may be used in connection with the present invention include asphalt patch carts such as those sold by Spaulding Manufacturing, Inc., of Saginaw Michigan (www.spauldingmfg.com).  
         [0003]     Past patch carts have employed several methods of heating the asphalt, for example, including diesel burner systems. Diesel systems may be preferred for safety reasons because they do not require large storage containers of volatile propane to be attached to the patch cart. Diesel systems also may be preferred for convenience because of the relative ease of refilling diesel fuel tanks versus refilling propane tanks. Electric-powered patch carts are also available, but these require a gasoline engine-powered generator to run the electric.  
         [0004]     A variety of commercially-available, asphalt-based materials containing bituminous materials and chemicals, including UPM (having a melting temperature or T m  of about 80° F.), HotMax (T m  of about 220° F.), and ColdPatch (T m  of about 180° F.) may be used in such patch carts, which typically require about 45 minutes-1 hour to heat these materials to their melting temperatures prior to their use on roadways. When the asphalt material reaches its melting temperature, a temperature sensor in connection with a solenoid valve, for example, shuts off the burner. A battery (typically 12 volts) located on the patch cart is then used to ignite the burner and continue heating of the asphalt after a predetermined period and/or after sensing that the asphalt&#39;s temperature has dropped below its melting temperature by a predetermined amount. This burner ignition and shut-off, and corresponding temperature cycling, continues throughout the day, including during transport of the patch cart from job-site to job-site.  
         [0005]     A problem frequently encountered with conventional patch carts is that during cycling, the patch cart battery often loses charge and does not have sufficient charge to ignite the burner. When this happens, the battery must be charged in the field, either by using a portable battery charger, or by using the battery on the truck used to transport the patch cart. Alternatively, the patch cart must be returned to its original location and its battery replaced with a new battery.  
         [0006]     Given its frequent use throughout a working day, the patch cart battery will quickly lose charge over time if not re-charged. A 12-volt battery will provide an average of about 550 cranking amps at 32° F., while at least 16 amps are typically need to ignite the burner. (As an example, about three hours of burner ignition, requiring re-lighting (at 70° F.) about every 20 minutes, in this environment will normally be sufficient to deplete the battery below the amperage necessary to reignite the burner.) Maintaining the charge of the patch cart battery above that necessary to ignite the burner by using the battery of the truck used to transport the patch cart can be problematic because of the distance between the front of the truck (where the truck battery is located) and the burner system on the patch cart located at the rear of the truck. For example, 4 amps may be dissipated over 15 feet if a 10-gauge cable/wire is used. Pick-up trucks, for example (often used to transport patch carts) often carry cable/wire (e.g., 14 gauge wire) which is too thin to effectively charge the battery. The patch cart battery may also lose power due to blown fuses or relays on the towing vehicle, or the driver shutting off the towing vehicle but not the patch cart (e.g, during break or lunch time).  
         [0007]     Accordingly, it would be desirable to provide a cost-efficient patch cart with a battery that is readily charged, providing a reliable burner system.  
       SUMMARY OF THE INVENTION  
       [0008]     The objects mentioned above, as well as other objects, are solved by the present invention, which overcomes disadvantages of prior patch carts, while providing new advantages not believed associated with such devices.  
         [0009]     In a preferred embodiment of the present invention, a solar power-assisted patch cart is provided. The patch cart includes a support surface for carrying and heating a bituminous material, such as asphalt, suitable for paving or repairing roadways. The patch cart also includes a heating source, such as diesel or propane fuel, to heat the support surface and bituminous material within the support surface. The patch cart further includes a solar-assisted battery for use in igniting a burner associated with the heating source. Preferably, a charge controller in electrical communication with the battery is provided, to facilitate maintaining the battery with a predetermined level of charge.  
         [0010]     In an alternative embodiment, a sufficient number/size of solar panel(s) may be used, preferably in combination with a battery booster, to power not only burner ignition but also the burner/engine itself. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The novel features which are characteristic of the invention are set forth in the appended claims. The invention itself, however, together with further objects and attendant advantages thereof, will be best understood by reference to the following description taken in connection with the accompanying drawings, in which:  
         [0012]      FIG. 1  is a perspective view of the patch cart of the present invention showing the solar panels in an exposed, energizing mode;  
         [0013]      FIG. 2  is an enlarged perspective view of an upper portion of the patch cart shown in  FIG. 1 ;  
         [0014]      FIG. 3  is a view similar to  FIG. 2  illustrating the solar panels in a retracted, rest mode;  
         [0015]      FIG. 4  is a rear perspective view of the upper portion of the patch cart shown in  FIG. 3 ;  
         [0016]      FIG. 5  is a side perspective view of the patch cart of the present invention attached to the rear of a vehicle pulling the patch cart;  
         [0017]      FIG. 6  is an enlarge view of the slidable pin and channel on support bar  25  shown in  FIG. 3 ; and  
         [0018]      FIG. 7  is a front and side perspective view of a conventional diesel burner, in partially unassembled form.  
       DEFINITIONS OF CLAIM TERMS  
       [0019]     The terms used in the claims of the patent as filed are intended to have their broadest meaning consistent with the requirements of law.  
         [0020]     “Bituminous” means any of a variety of particulate materials, including but not limited to the material commonly referred to as “asphalt,” which may be used to repair road surfaces.  
         [0021]     Where alternative meanings are possible, the broadest meaning is intended. All words used in the claims are intended to be used in the normal, customary usage of grammar and the English language. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]     Set forth below is a description of what are believed to be the preferred embodiments and/or best examples of the invention claimed. Future and present alternatives and modifications to this preferred embodiment are contemplated. Any alternatives or modifications which make insubstantial changes in function, in purpose, in structure, or in result are intended to be covered by the claims of this patent.  
         [0023]      FIG. 1  shows a preferred embodiment of the patch cart of the present invention, generally referred to by the reference numeral  15 . Patch cart  15  includes a container or enclosure  20  which may have funneling, sloping sides  21  and an interior support surface (not shown). Asphalt or another bituminous material suitable for repairing roadways may be loaded into the patch cart enclosure  20  and carried on the inner support surface.  
         [0024]     Still referring to  FIG. 1 , patch cart  15  may include a fire extinguisher  80 , a heat exhaust  100 , a diesel tank(s) located in an enclosure  60 , and a computer  40  for controlling various operations as further described below. Alternatively, propane gas stored in cylinders, for example, may be used to heat the enclosure  60 . A battery  50  ( FIG. 5 ) may be used to ignite the burner for the diesel or propone fuel. Patch cart  15  may be attached to the rear of a vehicle  90  as shown in  FIG. 5 .  
         [0025]     Referring to  FIG. 7 , a conventional diesel burner  140  for igniting diesel fuel to heat the patch cart is shown in partially unassembled form. Diesel burner  140  may include electric components  141 , a blower motor  142 , igniters  143 , an injector  145 , and a fuel pump assembly  147 .  
         [0026]     Referring now to  FIGS. 1 and 4 , in a particularly preferred embodiment a battery charge controller  30  in electrical communication with battery  50  may be used to control charge to battery  50 , as further explained below. Battery  50  and charge controller  30  are preferably solar powered, such as by solar panels  35 , and are in electrical communication with the solar panels for this purpose. Battery  50  may be used to ignite a burner(s) associated with the fuel source used to heat enclosure  20 .  
         [0027]     While solar panels are commercially available, in a preferred embodiment it was found to be cost-effective to use solar panels that had previously been used for that purpose as arrow markers by the state highway authority. Alternatively, commercially available solar panels which may be used include, for example:  
         [0028]     12 volt, 4.55 amps: http://www.solar-electric.com/bpso80wasopa.html  
         [0029]     12 volt. 7.1 amps: http://www.solar-electric.com/bpso125wasop.html  
         [0030]     To avoid contact with asphalt loaded in the patch cart, solar panels  35  may be retracted, as shown in  FIGS. 3-5 . For this purpose, solar panels  35  may be allowed to rotate or fold relative to the patch cart, such as relative to inner and outer pairs of vertical support bars  25 ,  26  and horizontal support bar  27 , which may be attached to the side of patch cart enclosure  20 . Referring to  FIGS. 3 and 6 , for this purpose channels  25   a ,  25   b  may be provided within support bar  25 , so that a slidable pin  25   c  may move within these channels between locked and unlocked positions. Providing solar panels  35  with a retraction or folding capability allows the solar panels to remain out of the way during loading of the patch cart.  
         [0031]     Preferably, solar panels  35  may be placed in electrical communication, such as by hard wiring, to a battery charge controller  30 , shown in  FIG. 4 . The battery charge controller  30 , such as the Solar Charge Controller and Power Booster from Advanced Energy Group, prevents overcharging of the battery system  50 , shown in  FIG. 5 , in daylight, and also prevents drainage of the battery at night, such that the battery may be maintained with a predetermined level of charge. In an alternative embodiment of the invention, multiple solar panels may be used in conjunction with a charge controller and booster, to enable the patch cart to be fully solar powered, such that power assist from the towing vehicle is not required.  
         [0032]     The heating mechanism initiated by the battery system  50  may be any of a number of types of heating mechanisms well known in the art. One such suitable heating mechanism known in the art is a fuel such as diesel fuel. Another suitable heating mechanism known in the art is propane fuel. Another suitable heating mechanism known in the art is an electric powered heating system.  
         [0033]     In an alternative embodiment, a sufficient number/size of solar panel(s) may be used, preferably in combination with a battery booster, to power not only burner ignition but also the burner/engine itself. For example, with a diesel-powered Spaulding patch cart it was found that about 16 amps were necessary to power the diesel burner heating the patch cart. Each solar panel referenced above provides about 3 amps of current. Accordingly, using two or more solar panels for powering a 12-volt battery, in conjunction with a battery booster, provides sufficient current to power the diesel burner without need for power assist from another vehicle.  
         [0034]     Other changes and modifications constituting insubstantial differences from the present invention, such as those expressed here or others left unexpressed but apparent to those of ordinary skill in the art, can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages; It is, therefore, intended that such changes and modifications be covered by the following claims.