Patents by Inventor Dexter R. Plummer

Dexter R. Plummer 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: 4747307
    Abstract: A positive displacement liquid flow meter uses two variable volume chambers 16,18 arranged in parallel, each with a reciprocable piston 24,26. While liquid from one chamber is being fed to the outlet 11, the other chamber is being charged with the liquid from the inlet 10. A sensing piston 32 in the outlet line 11 indicates when flow variation occurs and allows a feed back signal to be produced to produce the necessary alteration in movement of the piston from the chamber which is feeding the outlet line. Valves A, B, C, D are provided on either side of each chamber, so that when a chamber is feeding it is isolated from the liquid supply.
    Type: Grant
    Filed: January 23, 1987
    Date of Patent: May 31, 1988
    Assignee: Ford Motor Company
    Inventors: Victor C. Humberstone, Dexter R. Plummer
  • Patent number: 4528760
    Abstract: A transducer is described which has primary application in a clinometer, detail of which is also contained in the application.The transducer comprises a hollow cylindrical housing of glass or plastics material (10) having a single electrode (12) mounted on one end face and three equal equally spaced electrodes (14,16 and 18) on the opposite end face.The three separate capacitors having a common plate (12) control the frequency of oscillation of three oscillator circuits (30,32 and 34) the outputs of which are compared by comparators (38,46 and 48) and decoded by decoding circuit (40). A computing device (42) provides an output signal for an indicator (44).An audible indication of inclination for use in combination with the device is described.
    Type: Grant
    Filed: February 20, 1981
    Date of Patent: July 16, 1985
    Assignee: PA Consulting Services Limited
    Inventor: Dexter R. Plummer
  • Patent number: 4320941
    Abstract: A device is described for compensating for the movement of a cinematographic films through a camera or projector. By using the device, so intermittent film motion through the gate of the camera or projector can be dispensed with and the film can be moved continuously therethrough the camera or projector.The invention lies in the use of a plurality of inverting reflectors typically Amici prisms (70) moving in the same direction as the film (20) but at one half the speed of the film. The path of the prisms (70) is determined by a straight line segment (74) of a track (72), the straight line segment (74) being parallel to the direction of movement of the film (20).By illuminating the film over a width of at least one and a half frames using a condenser lens (18) so a number of partial images are obtained which are reconstituted in the optics so as to form in the projected image a composite frame which in general will be made up of two or three images of frame parts from two or three adjoining frames.
    Type: Grant
    Filed: October 22, 1979
    Date of Patent: March 23, 1982
    Assignee: PA Management Consultants Limited
    Inventors: Nigel J. R. Dashwood, Dexter R. Plummer
  • Patent number: 4208589
    Abstract: Optical scanner with a light beam reciprocated parallel to itself includes a stationary inlet for the light beam, an elongated first prism having a parallelogram shape disposed downstream from the stationary inlet in travel direction of the light beam, the first prism extending transversely to the light beam and having an inlet end through which the light beam is admitted to the first prism and twice reflected therein, the first prism having an outlet end from which the light beam leaves the first prism in a direction parallel to the direction in which it is admitted through the inlet end to the first prism, a second prism similar to the first prism having an inlet end disposed downstream of the outlet end of the first prism in travel direction of the light beam, the second prism having an outlet end determining respective location for the light beam leaving the scanner during a scanning operation, a first rotating carrier for the first prism having a mathematical rotary axis extending in the same direction a
    Type: Grant
    Filed: January 24, 1978
    Date of Patent: June 17, 1980
    Assignee: Schumag GmbH
    Inventors: Nigel J. R. Dashwood, Dexter R. Plummer
  • Patent number: 4200828
    Abstract: Apparatus for controlling the movement of a phonograph arm, pivoted for movement in horizontal and vertical planes, so as to maintain a desired stylus pressure. Displacement of the stylus resulting, for example, from passages of heavy modulation is used to generate electrical signals. A feedback system utilizes these signals to control the operation of horizontal and vertical rotational control devices.
    Type: Grant
    Filed: February 2, 1978
    Date of Patent: April 29, 1980
    Assignee: Streathern Audio Limited
    Inventors: Keith D. Ridler, Dexter R. Plummer
  • Patent number: 4149807
    Abstract: A method of reproducing characters or symbols in place of orthodox typing or printing comprises applying ink to successive points on the paper or other surface by means of a transducer forming a typehead, and building up each character by steering the transducer under the control of digitally stored information which may be selected from the store by a keyboard. The characters can be built up as a series of overlapping dots and each character may have a number of key points, the transducer moving along one of a limited number of pre-set paths from each key point to the next.
    Type: Grant
    Filed: March 1, 1977
    Date of Patent: April 17, 1979
    Assignee: Facit Aktiebolag
    Inventors: Gerald Avison, Philip T. Blenkinsop, John D. Marsh, Dexter R. Plummer
  • Patent number: 4105961
    Abstract: This invention relates to arrangements for use in controlling the movement of a pivoted arm and it has particular, though not exclusive, application in controlling the movement of a phonograph pick-up arm.
    Type: Grant
    Filed: November 25, 1975
    Date of Patent: August 8, 1978
    Assignee: Strathearn Audio Limited
    Inventors: Dexter R. Plummer, Roderick F. Jones