Patent Application
20150027564
1. Field of the Invention
This invention relates to an overfill prevention system that serves to monitor and control the fuel filling process to protect against overfilling of a tank, and more specifically to an overfill prevention system that comprises a fuel shut off sensor assembly connected electronically to a power take off switch assembly, which controls the fuel pump and stops the flow of gasoline or diesel from the fuel reservoir to the tank being filled.
2. Description of Related Art
Fuel distributors use large transport truck tractors, cargo tank trailers and bobtail tank trucks to provide fuel, oil or other fluids to heavy machinery in the field that is unable or impractical to fuel at a regular fill-up station. These large fuel transports can be used to transport fuel and oil over a large region to customers who use the fuel for various purposes including specifically to fuel frac equipment.
One concern fuel distributors face is the accidental over-filling that can occur as the fuel or oil is being pumped from a transport to the heavy machinery or frac equipment. Because of the nature of the fuel and oil being pumped, accidental overfills can create adverse health and environmental issues that must be addressed by the fuel distributor. As such, personal and environmental safety are top priorities of fuel distributors. Additionally, there are significant costs associated with overfilling including both the environmental cleanup costs as well as the cost of the wasted fuel or oil. These costs are also borne by the fuel distributor.
There are current systems in place that use fuel probes located within a fuel tank that are designed to sense the fuel level within the tank. These fuel probes are typically connected electronically to a secondary overfill prevention system, such as the IntelliCheck®2 System from the Scully Signal Company. Once the fuel probe in the tank senses that the fuel level has reached the preset level of capacity (typically when the fuel is within 60 gallons of maximum capacity), the secondary overfill prevention system indicates that the tank has reached this capacity. However, the secondary overfill prevention system does not have the ability to shut off the pump and stop the flow of fuel.
It is therefore desirable to have an overfill prevention system, which has a fuel shut off sensor assembly connected electronically to a switch assembly connected to the pump via a power take off switch assembly, which controls the flow of gasoline from the fuel reservoir to the tank being filled, thus preventing expensive and dangerous overfill situations.
The present invention provides generally for an overfill prevention system that serves to monitor and control the fuel filling process to protect against overfilling of a tank. The overfill prevention system uses a fuel shut off sensor assembly connected electronically to a power take off switch assembly, which controls the flow of fuel from the fuel reservoir to the tank being filled.
In a preferred embodiment, the overfill prevention system includes two components: a fuel shut off sensor assembly (“FSOSA”) and a power take off switch assembly (“PTOSA”). The FSOSA is located on or near the tank that is being filled and is connected electronically to a secondary overfill prevention system, such as the IntelliCheck®2 System from the Scully Signal Company. The FSOSA comprises a bracket that is mountable to or near the tank and near the secondary overfill prevention system. The bracket includes a two-wire cable with a first end connected to the secondary overfill prevention system and a second end connected to the bracket. The first end is connected to the secondary overfill prevention system in such a way as to receive the signal from that system that the fuel in the tank has exceeded its safe fuel limits during the filling process. The second end of the cable is wired to a cable receptacle, which is connected to the bracket and protected by a hinged cover. Preferably the receptacle is a traditional four pin receptacle.
The PTOSA is located on the fuel distribution truck and is comprised of a housing with a cover, internal electronics including wiring and relays, and a switch. In a preferred embodiment, the cross section of the housing is preferably square in shape with four sides, a top and a bottom. Mounted externally to one of the sides of the housing are an air intake port, an air outlet port, and a cable receptacle with a hinged cover. Additionally, there is a two-wire power cable which protrudes through a side of the housing and is attached to an external power supply, preferably the battery on the fuel distribution truck. There is an indicator light and toggle switch mounted externally to the top of the housing, which is removable from the sides and bottom of the housing. Internally, the power supply cable is attached electronically first through the toggle switch and then to a relay. There is a pneumatic switch located in the housing, which is electronically connected to the relay and controls the flow of air between the air intake port and air outlet port. When the switch is open, air can flow from the air intake port to the air outlet port, but when the switch is closed, the flow of air is stopped. The external cable receptacle is also connected electronically to the toggle switch and relay. The indicator light is connected electronically to the relay.
In the preferred embodiment, the PTOSA is connected to the air tank on the distribution truck via the air inlet port and the PTOSA air outlet port is connected to the truck's power take off. When the power take off is receiving air, then the power take off powers the fuel pump and fuel is pumped from the distribution truck. In operation, the fuel distributor connects a two-wire cable between the FSOSA and PTOSA by plugging the cable in to the respective cable receptacles on the FSOSA and PTOSA. This two-wire cable is looped electronically through the secondary overfill prevention system and electrical current flows from the PTOSA down one wire to the secondary overfill prevention system and back to the PTOSA along the other wire. The toggle switch on the PTOSA is in the on position and the indicator light is on. The fuel flows from the fuel distribution truck into the tank until the fuel makes contact with the fuel probe in the tank.
Once fuel contacts the fuel probe, a communicator signal is sent to the secondary overfill prevention system. The secondary overfill prevention system closes a switch, which stops the looping flow of electricity through the two-wire cable between the secondary overfill prevention system and the FSOSA and then between the FSOSA and the PTOSA along the connecting cable. Once the electricity flow is stopped from the secondary overfill prevention system to the PTOSA, the indicator light turns off and the pneumatic switch is flipped automatically stopping the flow of air from the distribution truck's air tank to the power take off. This stops the flow of fuel to the tank and prevents costly, damaging and dangerous overfills. The operator can then flip the manual toggle switch to off and move on to the next fuel job. If the probe is set at a level that is above the desired level in the tank, then the operator must drain some fuel from the tank before moving on to the next fuel job.
In an alternative embodiment, the switch located in the housing of the PTOSA is an electrical switch, which is electronically connected to the relay and controls the flow of electricity directly to the pump. Rather than the PTOSA having an air intake and air outlet ports, the pump's electrical cable enters the PTOSA and is connected to the electrical switch. The operation of the PTOSA is the same as described above, and when fuel contacts the fuel probe, the switch flips and no electricity flows to power the electrical pump.
If at any time during the filling, the operator needs to stop the flow of fuel, he can flip the manual toggle switch from the on to off position. Also, a dummy plug is available to plug into the cable receptacle on the PTOSA, which completes the circuit and allows the manual operation of the system through the use of the toggle switch on the PTOSA. This is useful in situations where the fuel indicator probe is inoperable or if the distributor wishes to add more fuel than the preset tank limit.
The novel features and construction of the present invention, as well as additional objects thereof, will be understood more fully from the following description when read in connection with the accompanying drawings.
The improved process of the invention is further described and explained in relation to the following figures of the drawings wherein:
Like reference numerals are used to describe like parts in all figures of the drawings.
Referring to
Fuel shut off sensor assembly (“FSOSA”) 36 is mounted on bobtail tanker 12 near secondary overfill prevention system 40 and is in electronic connection with secondary overfill prevention system 40 via cable 38. Cable 38 is preferably a two-wire cable connected electronically to secondary overfill prevention system 40 in such a way that an electrical signal initially received from power take off switch assembly (“PTOSA”) 32 is looped through FSOSA 36 to secondary overfill prevention system 40 and back to FSOSA 36 via cable 38. Once secondary overfill prevention system 40 receives the communicator signal from fuel probe 42, the looping electric signal is interrupted. FSOSA 36 is comprised of a bracket and a cable receptacle. Cable 34 is connected to FSOSA 36 and passes the looping electrical signal received from PTOSA 32 to FSOSA 36. PTOSA 32 is connected in pneumatic connection with air tank 18 of tanker truck 10 via air line 20, which is also connected to the power take off of tanker truck 10. Power take off of tanker truck 10 drives a shaft which in turn drives fuel pump 16. When the looping electrical signal is interrupted and no longer received back by PTOSA 32, PTOSA 32 shuts off air flow through air line 20, which in turn ultimately turns off fuel pump 16 and stops the flow of fuel from tank 22 of tanker truck 12 to tank 24 of bobtail tanker 12.
Referring to
Referring to
In operation, the operator connects fuel hose 14 from tanker truck 10 to bobtail tanker 12 as well as connecting FSOSA 36 to cable receptacle 60 on PTOSA 32 with cable 34. The operator flips toggle switch 52 to the on position, which opens pneumatic switch 70 and illuminates indicator light 50. Air tank 18 provides air via air line 20 to the power take off of pump 16, which begins the flow of fuel from tanker 10 to bobtail 12. Once tank level 44 contacts signal probe 42, a communicator signal is to secondary overfill prevention system 40. Once the communicator signal is received by secondary overfill prevention system 40, the looping electrical signal is interrupted and no electrical signal passes back along cable 38 to FSOSA 36 and then along cable 34 to PTOSA 32. Once PTOSA 32 receives no electrical signal via receptacle 60, indicator light 50 turns off and pneumatic switch 70 closes. This automatically stops the flow of air from air tank 18 to the power take off on tanker truck 10 which ultimately stops the flow of fuel between tank 10 and bobtail 12 by no longer powering fuel pump 16.
If at any time during the filling, the operator desires to stop the flow of fuel from tanker 10 to bobtail 12, he can flip toggle switch 52 from the on to off position. Flipping toggle switch 52 causes pneumatic switch 70 to close, which automatically stops the flow of air and stops fuel pump 16. To resume the flow of fuel, the operator would simply flip toggle switch 52 back to the on position. In situations where signal probe 42 or secondary overfill protection system 40 is inoperable, a dummy plug is available to plug into cable receptacle 60 on PTOSA 32. The dummy plug completes the circuit (e.g., makes a looping electrical signal) and allows the manual operation of the system wherein the operator controls the flow of fuel soley by use of toggle switch 52. The dummy plug is also useful when the distributor wishes to raise fuel level 44 of tank 24 on bobtail 12 past signal probe 42.
Other alterations and modifications of the invention will likewise become apparent to those of ordinary skill in the art upon reading the present disclosure, and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventors are legally entitled.
