Patents by Inventor John Callahan

John Callahan 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: 4100400
    Abstract: Price encoder for delivering pulses corresponding to the price of gasoline or other liquid petroleum products dispensed by a pump. The encoder is removably mounted on the existing mechanical price computer in the pump and includes an input gear for engaging a drive gear on the computer. A pulse generator coupled to the input gear provides pulses at a higher rate than required for the output, and this pulse rate is reduced by a counter to provide a desired number of pulses per unit price. The counter is reset in response to the application of operating power to eliminate errors which might otherwise arise when the pump is reset.
    Type: Grant
    Filed: September 17, 1976
    Date of Patent: July 11, 1978
    Assignee: RF Products Corp.
    Inventors: John A. Callahan, Allan S. Ottenstein