Patents by Inventor Roger A. Frost

Roger A. Frost 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: 5139105
    Abstract: A vehicle has at least two pairs of ground engaging wheels, which vehicle can alternatively be steered with two or four wheels, the vehicle comprising a chassis having first and second pairs of ground engaging wheels which are movable to effect steering of the vehicle, the wheels of each pair being mounted at opposite sides of the chassis and the second pair of wheels being lockable in a position such that simple steering is effected solely by the first pair of wheels, the first pair of wheels being movable to effect steering by a first fluid actuator to which fluid is fed from a steering valve, and the second pair of wheels being movable by a second fluid actuator to which fluid is fed via a steering mode selector valve from the steering valve means, the steering mode selector valve having a first operating condition when fluid from the steering valve is not fed to the second fluid actuator whereby simple steering is effected solely by the first pair of wheels and a second operating condition wherein fluid f
    Type: Grant
    Filed: January 24, 1991
    Date of Patent: August 18, 1992
    Assignee: J. C. Bamford Excavators Limited
    Inventors: Roger A. Frost, Robert J. Andrew, Simon J. Langford
  • Patent number: 4917204
    Abstract: A materials handling vehicle having two pairs of ground wheels movable to effect steering of the vehicle, the wheels of each pair being mounted at opposite sides of the vehicle chassis, at least one pair of wheels being lockable in a position so that steering is effected solely by the other pair of wheels wherein sensor means are provided associated with each of the two pairs of wheels to provide an electrical signal to a control means when the respective wheels are in an aligned position in which their axes of rotation are perpendicular to a longitudinal axis of the vehicle, the control means including a selector means comprising electrical switch means to enable an operator to select simple steering mode in which only one of the pairs of wheels are movable to effect steering, or a compound steering mode in which both of the pairs of wheels are movable to effect steering, the control means further comprising means to maintain the selected steering mode until an alternative steering mode is selected by operat
    Type: Grant
    Filed: July 20, 1988
    Date of Patent: April 17, 1990
    Assignee: J. C. Bamford Excavators Limited
    Inventors: Robert J. Andrew, Roger A. Frost, Paul F. Herbert
  • Patent number: 4669947
    Abstract: An earth moving implement which, in use, is mounted on a boom which is attached to an excavating or other vehicle, comprises a bucket mounted on a boom of a vehicle, at least one loading fork, a mounting link secured to the bucket for movement between a lower extreme position, and an upper position, the link having first and second abutments, the loading fork being pivotally mounted on the mounting link for movement between an "in use" position when the mounting link is in its lower extreme position, and the fork extends generally forwardly of the bucket, and a part of the fork is in engagement with the first abutment to prevent movement of fork towards the bucket, and a stowed position when the mounting link is is an upper position and a further part of the fork is in engagement with the second abutment of the mounting link to prevent further pivotal movement of the fork relative to the mounting link.
    Type: Grant
    Filed: May 30, 1985
    Date of Patent: June 2, 1987
    Assignee: J. C. Bamford Excavators Limited
    Inventor: Roger A. Frost