Patents by Inventor Mark R. Pflederer

Mark R. Pflederer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4604675
    Abstract: A fuel injection solenoid driver circuit controllably connects and disconnects a solenoid coil to and from a storage capacitor to effect operation of the coil. Precise control of the timing and duration of coil is necessary to ensure that a proper quantity of fuel is delivered to each cylinder of an internal combustion engine. A means monitors the voltage level of the storage capacitor and periodically delivers a high voltage inductive spike to the capacitor to maintain the capacitor voltage level within prescribed limitations. Further, a means aids in charging the capacitor by discharging the solenoid coil to the capacitor in response to the coil and capacitor being disconnected. Use of the energy stored in the coil to recharge the capacitor increases the power efficiency of the circuit and also results in a fast decay of the solenoid voltage. The fast decay time minimizes variations in solenoid operation timing and duration and precisely controls the quantity of fuel delivered.
    Type: Grant
    Filed: July 16, 1985
    Date of Patent: August 5, 1986
    Assignee: Caterpillar Tractor Co.
    Inventor: Mark R. Pflederer