Overflow prevention mechanism for liquid transfer systems

A fuel transfer system for repeatedly transferring fuel from a main fuel source to a fuel tank and preventing overflow of the fuel tank as a result of such fuel transfer, the system comprising;

• a fuel path fluidly connecting the main fuel source to the fuel tank;
• an electrically controllable flow control device positioned along the fuel path for enabling controlled delivery of fuel through the liquid path from the main fuel source to the fuel tank along the fuel path;
• a normally-open switching device electrically connected between a source of electrically energy and the electrically controllable flow control device;
• a normally-closed switching device electrically connected in series between the source of electrical energy and the normally-open switching device;
• a fuel level sensor operatively positioned relative to the fuel tank for sensing a level of fuel within the fuel tank and producing an output indicative of such level;
• an electronic controller electrically connected to the fuel level sensor for receiving the output therefrom, the normally-open switching device for controlling the closing and opening thereof, and the normally-closed switching device for controlling the opening thereof, the controller being operative to open the normally-closed switching device when the controller receives the output from the fuel level sensor, the opening of the normally-closed switching device removing the source of electrical energy from the normally-open switching device.

An overflow prevention mechanism for use in association with a fuel transfer system, the fuel transfer system including a pump fluidly connected between a source of fuel and a fuel tank which may be filled with fuel from the source of fuel by operation of the pump, the pump controlling delivery of fuel through a liquid path between the source and fuel tank, a relay electrically connected between a source of electrical energy and a pump motor which operates the pump, and a fuel level sensor operatively positioned relative to the fuel tank for sensing when the fuel level within the fuel tank reaches a predetermined high level at which it is desired to stop further fuel transfer thereto, the fuel level sensor operatively connected to the relay to effect control thereof, the overflow prevention mechanism comprising:

• a backup fuel level sensor for sensing if the level of fuel within the fuel tank reaches an extreme high level which is higher than the predetermined high level and corresponds to a overfilling condition, the backup fuel sensor operable to produce an output when the fuel level within the tank reaches the extreme high level;
• and
• a shunt trip breaker electrically connected in series between the source of electrical energy and the relay, the shunt trip breaker operatively connected to the backup fuel level sensor so as to respond to the production of the backup fuel level sensor output by opening, thereby disconnecting the pump motor from the source of electrical energy when the fuel level within the fuel tank reaches the extreme high level.

A material transfer system for repeatedly transferring a material from a main source to a container while inhibiting the occurrences of undesirable material levels in the container, the system comprising:

• a material path physically connecting the main source to the container for delivery of material between the main source and the container;
• an electrically controllable flow control device positioned along the material path for enabling controlled delivery of material through the material path from the main source to the container along the material path;
• a first material level sensor operatively positioned relative to the container for sensing when a level of material within the container reaches a first predetermined material level;
• a second material level sensor corresponding to a second predetermined material level;
• a third material level sensor corresponding to a third predetermined material level;
• a normally-closed switching device electrically connected between a source of electrical energy and the electrically controllable flow control device;
• and
• a normally-open switching device electrically connected between the source of electrical energy and the electrically controllable flow control device, the normally-open switching device being in series with the normally-closed switching device;
• the first material level sensor being operatively connected to the normally-closed switching device for effecting the opening thereof when the level of material in the container reaches the first predetermined material level,
• the second and third material level sensors being connected to the electronic controller, the third material level sensor being operable to produce an output indicative of the level of material within the tank having fallen to a third predetermined material level, the second material level sensor being operable to produce an output indicative of the level of material within the tank having risen to a second predetermined material level which is higher than the third predetermined material level, and the first material level sensor is operable to produce an output indicative of the level of material within the tank having risen to the first predetermined material level which is higher than the second predetermined material level.