Patents by Inventor Carl H. Weisenfelder

Carl H. Weisenfelder 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).

  • Shifting apparatus for a drawworks transmission
    Patent number: 4683994
    Abstract: Drawworks transmission shifting apparatus is described that provides an arrangement of control valves, cylinders, clutches and brakes which permit the rig operator to shift the drawworks transmission into the desired setting and to lock the transmission in those positions by the use of remotely controlled pneumatically powered cylinders.
    Type: Grant
    Filed: April 12, 1985
    Date of Patent: August 4, 1987
    Assignee: IRI International Corporation
    Inventor: Carl H. Weisenfelder