Abstract:
An overflow protection system for an oil tank trailer which automatically monitors and controls the level of oil within said trailer. The system comprises a float sensor, a cable assembly, a shutoff valve, a temperature sensor, and a control box. The float sensor comprises an inductive float sensor which monitors the level on the tank gauge of an existing trailer body, which provides electrical signals via the cable assembly. The cable assembly provides electronic connection between the float sensor, valve, temperature sensor, and control box. The shutoff valve is closed when the float sensor is triggered, preventing flow into and out of the tank in order to eliminate overflow spillage. The control box includes a plurality of manual user controls for operating the system as well as information displays including interior temperature and the like.

Description:
RELATED APPLICATIONS 
     The present invention was first described in a notarized Official Record of Invention on Nov. 9, 2009, that is on file at the offices of Montgomery Patent and Design, LLC, the entire disclosures of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates generally to oil tank trailers, and in particular, to an overflow protection device for an oil tank trailer. 
     BACKGROUND OF THE INVENTION 
     In modern society, we rely greatly on the use of oil for heating, transportation, and energy needs. The vast majority of this oil is transported via a tanker trailer. The filling of a tanker trailer with oil is a somewhat complicated process. There are many factors to be considered such as the temperature of the incoming oil, capacity of the tanker trailer, current fill status, and the like. 
     Unfortunately, many tanker trailers are only equipped with a simple level gauge which severely limits the amount of information available to the filling operator. 
     As such, many instances of overfilling occur on a daily basis. Such overfill situations are dangerous, costly to clean up, and may also result in EPA violations. 
     Various attempts have been made to provide liquid tank monitoring and overflow protection systems and apparatuses. Examples of these attempts can be seen by reference to several U.S. patents, such as U.S. Pat. Nos. 4,903,672; 5,052,223; 5,187,979; 5,226,320; 5,632,302; 6,154,144; and 6,229,448. 
     While these systems fulfill their respective, particular objectives, each of these references suffer from one (1) or more of the aforementioned disadvantages. Many such systems are only utilized with stationary tanks and unsuited for use with oil tank trailers. In addition, while many such apparatuses monitor or measure fluid levels, they are not capable of automatic operation in response to fluid conditions. Furthermore, many such systems are not able to be incorporated with existing tank trailer electrical and mechanical components. Also, many such systems do not provide additional manual operation and data readout beyond fluid level to allow a user to make educated decisions while filling a tank. Accordingly, there exists a need for an overflow protection device for an oil tank trailer without the disadvantages as described above. The development of the present invention substantially departs from the conventional solutions and in doing so fulfills this need. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing references, the inventor recognized the aforementioned inherent problems and observed that there is a need for a system incorporated with existing components of an oil tank trailer to augment normal operation by providing detailed measurements and readout for enhanced manual decision making and automatic overflow protection. Thus, the object of the present invention is to solve the aforementioned disadvantages and provide for this need. 
     To achieve the above objectives, it is an object of the present invention to prevent overfilling of a tank of a tanker truck with oil. The system includes an air-operated control valve in communication with the tank, a pump having a solenoid for pumping oil into the tank, a parking brake coupled to the tanker truck, a float sensor within the tank for monitoring the fluid level within the tank, and a control box positioned on an exterior of the tank. Overfill prevention is accomplished by monitoring the oil level within the tank and utilizing the oil level to automatically control the pump. 
     Another object of the present invention is to include an operating mode switch within the control box which enables a user to choose various operating modes for the air-operated control valve including a continuously open position, a continuously closed position, and an automatically-operating mode wherein the control valve is closed when the tank level reaches a predetermined fill level. 
     Yet still another object of the present invention is to prevent further accidents by disabling the system when the parking brake is not active. 
     Yet still another object of the present invention is to provide additional data for accurate assessment of conditions within the interior of the tank by including a temperature sensor within the tank. The temperature sensor provides a display signal to a temperature readout on the control panel to aid a user in making decisions regarding pump operation. 
     Yet still another object of the present invention is to provide override and test operations including visual and audible alarms for assessing the working condition of the system prior to use. 
     Yet still another object of the present invention is to provide a method of utilizing the device that provides a unique means of acquiring the system, activating the tanker truck parking brake, testing the system, positioning the operating mode switch in either the open or automatic position as desired, utilizing the temperature information displayed by the readout in the decision making process, and providing automatic stopping of the pump. 
     Further objects and advantages of the present invention will become apparent from a consideration of the drawings and ensuing description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and features of the present disclosure will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
         FIG. 1  is a side view of a tanker truck fluid level control system  10  as provided upon a tanker truck  15 , according to the preferred embodiment of the present invention; 
         FIG. 2  is a front view of the main control box  35 , as used with the tanker truck fluid level control system  10 , according to the preferred embodiment of the present invention; and, 
         FIG. 3  is an electrical schematic block diagram depicting the major electrical components of the tanker truck fluid level control, according to the preferred embodiment of the present invention. 
       DESCRIPTIVE KEY 
         10  tanker truck fluid level control system 
         15  tanker truck 
         20  tank 
         25  control valve 
         26  solenoid 
         27  pump 
         28  fluid line 
         30  level indicating system 
         31  inductive float sensor 
         35  main control box 
         39  parking brake 
         40  wiring harness 
         41  electrical cable 
         42  male plug 
         43  female plug 
         50  thermocouple 
         55  contained liquid product 
         60  weatherproof control enclosure 
         65  front panel 
         70  power switch 
         80  operating mode switch 
         90  incoming fluid temperature readout 
         95  audible alarm device 
         100  visual alarm device 
         110  temperature indication circuit 
         115  first display driver circuit 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The best mode for carrying out the disclosure is presented in terms of a preferred embodiment, herein depicted within  FIGS. 1 through 3 . However, the disclosure is not limited to a single described embodiment and a person skilled in the art will appreciate that many other embodiments are possible without deviating from the basic concept of the disclosure and that any such work around will also fall under its scope. It is envisioned that other styles and configurations can be easily incorporated into the teachings of the present disclosure, and only one particular configuration may be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. 
     The present invention describes a tanker truck fluid level control system (herein described as the “system”)  10 , which provides a means for monitoring and automatically controlling the level of oil in a tank  20  of a tanker truck  15 , thereby preventing an overfilling event due to human error. The system  10  would be constructed in general accordance with  FIG. 1  through  FIG. 3  and may be provided as new or optional equipment on a new tanker truck  15  or could also be provided as an add-on aftermarket kit for installation on an existing tanker truck  15 . 
     Referring now to  FIG. 1 , a side view of the system  10  as provided upon the tanker truck  15 , according to the preferred embodiment of the present invention, is disclosed. The tanker truck  15  is preferably a conventional vehicle which is hauled by a semi-tractor as illustrated herein. However, any type of tanker truck  15  or tanks  20  that are stationary for that manner can be used with the functionality of the system  10 . As such, the usage of any specific type of tanker truck  15  should not be interpreted as a limiting factor of the present invention. The tanker truck  15  is provided with a tank  20  and a method to fill it which is commonly a fluid or product pump  27 . 
     The flow of liquid material into the tank  20  is governed by an air-operated spring control valve  25  as would be conventionally expected. The control valve  25  would preferably be included with the pump  27  on an inlet which pumps fluid into the tank  20  via a length of fluid line  28 . Additionally, also in a conventional manner, the tank  20  is provided with a level indicating system  30  which preferably comprises an inductive float sensor  31  or a similar proximity switch to determine when the tank  20  is filled to a maximum capacity. When filled to a maximum capacity, such as when the fluid reaches the inductive float sensor  31  and the parking brake  39  is applied within the tanker truck  15 , a positive air shutdown will stop the tanker truck  15  engine and operate a solenoid  26  within the pump  27  intake to discontinue the flow of fluid and eliminating overfilling the tank  20 . 
     The tanker truck  15  interfaces to various other electro/mechanical components of the system  10  via interconnection of electrical cable  41  to a wiring harness  40  on the tanker truck  15  which supplies electrical power to the system  10 . The electrical wiring  41  is specifically interconnected to the existing parking brake  39  to the wiring harness  40 , thereby providing an enabling signal in correspondence with a main control box  35 . Further, this setup will only enable the system  10  to operate when the parking brake  39  is set which will discontinue operation or halt operation if said parking brake  39  is not set. An interface created with the electrical cable  41  is also provided to a thermocouple  50  or similar temperature sensor to allow for monitoring of the temperature of a contained liquid product  55  within the tank  20  such as oil or the like. As oil heats it begins to foam or bubble which will falsely identify the tank  20  as being full and an inductive flat sensor  31  with stop pumping said oil. The thermocouple  50  along with an incoming fluid temperature readout  90  (see  FIG. 2 ) will enable a user or an operator to determine such a premature stopping of the system  10 . Electrical interfaces are also provided to the air-operated control valve  25  and the level indicating system  30  via the electrical cable  41  as well. 
     A main control box  35  is located in a prominent and readily visible location which is illustrated herein upon an exterior surface of the tank  20 . It should be noted that the location of the control box  35  that is illustrated in  FIG. 1 , is for illustrative purposes only and is not intended to be a limiting factor of the present invention. The main control box  35  is removable attachable to the power supply via a male plug  42  and female plug  43  which further connected to electrical cable  41 . The plugs  42 ,  43  are preferably common four (4) pin connecting devices, yet other means of interconnection may be utilized without limiting the scope of the system  10 . The functionally and operation of the main control box  35  will be described in greater detail herein below. 
     Referring now to  FIG. 2 , a front view of the main control box  35 , as used with the system  10 , according to the preferred embodiment of the present invention, is disclosed. The main control box  35  consists of a weatherproof control enclosure  60  approximately twelve (12) inches by twelve (12) inches by six (6) inches. The main control box  35  comprises a flat front panel  65  upon a front surface which further includes a plurality of features which pertain to the operation of the system  10 . It should be noted that the weatherproof control enclosure  60  as well as all components mounted upon the front panel  65  are a weatherproof design suitable for the environment and temperatures likely to be encountered while on the road. 
     The front panel  65  comprises a power switch  70  which is preferably a sliding multi-position electrical switching device which enables the system  10  to be positioned into an OVERRIDE mode or a TEST mode. The TEST mode is provided to allow the user to test the system  10  which verifies a proper operation of said system  10 . The TEST mode should be part of periodic test program to ensure proper operation. The OVERRIDE mode enables the lines of the product pump  27  to be emptied when the inductive float sensor  31  has been tripped which will allow for a clean disconnect from a fuel wellhead. An audible alarm device  95  and a visual alarm device  100  will alert the user or operator when the system  10  is positioned in the OVERRIDE mode or TEST mode (see herein below). 
     An operating mode switch  80  is also provided on the front panel  65  comprising three ( 3 ) individual modes of operation. The first position allows the user to keep the air-operated control valve  25  open at all times such as during manual operation, emergency operation, or other similar functions. The second position allows the user to keep the air-operated control valve  25  closed at all times and would be the position that the operating mode switch  80  is normally left in when the system  10  is not in use. It should also be noted that the air-operated control valve  25  is a fail safe design that remains closed when either the loss of power or loss of air pressure occurs. The third and final position of the operating mode switch  80  allows for the automatic operation of the system  10  such that the air-operated control valve  25  is closed when the level of the tank  20  (as shown in  FIG. 1 ) approaches that of a filled position during the filling process. In such a manner, this assures that overflowing of the tank  20  via continued flowing of product into the tank  20  is impossible. Further explanation of the method of accomplishment of this task will be described in greater detail herein below. 
     The front panel  65  also contains provisions for mounting of an incoming fluid temperature readout  90  which will display the temperature of the incoming fluid as present at the air-operated control valve  25  in either Fahrenheit or Centigrade readings. The incoming fluid temperature readout  90  works together with the thermocouple  50  within the control valve  25 . The incoming fluid temperature readout  90  will provided valuable information to the user operator by providing information on temperature, viscosity, melting points, and the like. It should be noted that while the incoming fluid temperature readout  90  is depicted as digital numerical readouts such as discrete readouts, alphanumeric readouts, analog readouts, or the like can be used with equal effectiveness, and as such, should not be interpreted as a limiting factor of the present invention. 
     An audible alarm device  95  and a visual alarm device  100  are located at an upper surface of the front panel  65  and provide both audible and visual annunciation of an overflow condition local to the main control box  35 . Such annunciation will allow the user or operator to take corrective action to eliminate, reduce or mitigate the overflow condition. Such alarm devices  95 ,  100  will continue until the user corrects the condition or deactivates the system  10 . The audible alarm device  95  is speaker device which will broadcast an alerting sound or warning signal and the visual alarm device  100  is an illuminating device such as a light emitting diode (LED). 
     Referring now, to  FIG. 3 , an electrical schematic block diagram depicting the major electrical components of the system  10 , according to the preferred embodiment of the present invention, is disclosed. Electrical power is routed from the wiring harness  40  when the parking brake  39  is activated through the power switch  70  which enables the user or operator to position the system  10  in OVERRIDE mode or TEST mode which utilizes the alarm devices  95 ,  100 . This controlled power is then routed to a temperature indication circuit  110  which receives an input signal from the thermocouple  50 . The resultant signal is then passed to a first display driver circuit  115  which generates an appropriate signal for the incoming fluid temperature readout  90 . 
     Power is also routed to the inductive float sensor  31  in the level indicating system  30  which enables said float sensor  31  to indicate when the tank  20  is full. Power is also routed to the operating mode switch  80 . With the operating mode switch  80  in the AUTOMATIC setting the signal is used to open and close the air-operated control valve  25 . The OPEN setting of the operating mode switch  80  applies power to the air-operated control valve  25  all the time to keep it open at all times Likewise, the CLOSE position of the operating mode switch  80  removes all power from the air-operated control valve  25  at all times thus allowing the air-operated control valve  25  to return to its failsafe position of being closed at all times. 
     It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After installation and wiring in accordance with  FIG. 1  and  FIG. 3 , the system  10  is ready for operation. 
     The method of installing and utilizing the system  10  may be achieved by performing the following steps: acquiring the system  10 ; activating the tanker truck  15  parking brake  39 ; placing the operating mode switch  80  in the CLOSE position; testing the system  10  by positioning the power switch  70  in TEST mode and enabling the alarm devices  95 ,  100  to create an alerting signal; positioning the operating mode switch  80  in either the OPEN or AUTOMATIC position depending on the mode of operation (in the OPEN position, the contained liquid product  55  would flow into the tank  20  in a conventional manner thus relying on the user to prevent overflow conditions and in the AUTOMATIC mode, the system  10 , via use of the level indicating system  30  would control the operation of the air-operated control valve  25  and close it automatically when the level of the contained liquid product  55  in the tank  20  reaches the full level); utilizing the temperature information of the contained liquid product  55  as displayed by the incoming fluid temperature readout  90  in the decision making process; enabling the system  10  to stop pumping fluid into the tank  20  via activation of the inductive float sensor  31  and positioning the power switch  70  to OVERRIDE to clean the product pump  27  before disconnect; and, deactivating the system  10  by releasing the tanker truck  15  parking brake  39  as desired. 
     The foregoing descriptions of specific embodiments have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit to the precise forms disclosed and many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain principles and practical application to enable others skilled in the art to best utilize the various embodiments with various modifications as are suited to the particular use contemplated.