Patents by Inventor Joseph A. Crawford

Joseph A. Crawford 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: 5013970
    Abstract: A rapid start fluorescent system which has its starting capacitance connected to a tap on the secondary of the ballast transformer which tap is located at a predetermined number of turns of the secondary.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: May 7, 1991
    Assignee: North American Philips Corporation
    Inventor: Joseph A. Crawford
  • Patent number: 4970740
    Abstract: A bi-motional cradle has a base with rollers affixed along each of two sides. A motor mounted on the base drives a crank arm which imparts to and fro translational motion to a cradle frame which rests upon the rollers of the base. A mediate frame member which lies within the cradle frame supports a second motor. The second motor has a crank arm rotably attached thereto. A cradle is suspended from the cradle frame by means which allow the cradle to hang freely and oscillate. The second motor's crank arm engages the cradle during a part of that crank arm's rotational motion. As the second motor's crank arm engages the cradle, it imparts a motion to the cradle that causes the cradle to swing, or oscillate. A baby lying in the cradle is soothed by a gentle, steady, two-directional motion.
    Type: Grant
    Filed: May 14, 1990
    Date of Patent: November 20, 1990
    Inventor: Joseph Crawford
  • Patent number: 4954749
    Abstract: A fluorescent lamp system including a relay whose coil is connected across the secondary of the transformer of the system and whose contacts interrupt the connection of the electrodes of the lamp system to their associated heater windings after lamp turn on.
    Type: Grant
    Filed: November 15, 1988
    Date of Patent: September 4, 1990
    Assignee: North American Philips Corporation
    Inventor: Joseph A. Crawford
  • Patent number: 4740731
    Abstract: Apparatus for sequentially igniting and serially operating a pair of electric discharge lamps from a source of AC supply voltage. The apparatus includes a transformer with a primary winding and first and second secondary windings mounted on a magnetic core having a slot under the second secondary winding. The first secondary winding has a high leakage reactance and the windings are serially connected with the secondary windings wound in opposition to one another. First and second capacitors are connected in series with the first and second lamps, respectively, to prevent the flow of DC current therethrough. By a novel choice of the ratios of the capacitance values of the second capacitor to the first capacitor and of the slot dimensions, superior operating characteristics for the apparatus are achieved.
    Type: Grant
    Filed: November 26, 1986
    Date of Patent: April 26, 1988
    Assignee: Advance Transformer Company
    Inventor: Joseph A. Crawford
  • Patent number: 4517498
    Abstract: A ballast for a sequence start series operating circuit that includes two rapid start gaseous discharge lamps. The circuit includes a transformer with a primary winding and a loosely coupled secondary winding, a series first capacitor for providing a leading current when both lamps have been ignited and are operating and a second capacitor shunting the second-to-ignite lamp to by-pass that lamp during ignition of the first-to-ignite lamp and thereafter to develop a voltage across the second capacitor sufficient to ignite the second-to-ignite lamp when current flows in the by-pass branch. The lamps are of a variety which produces an undesirable current peak in the second-to-ignite lamp on each half cycle because the shunting second capacitor dumps its charge accumulated during each half cycle into the lamp.
    Type: Grant
    Filed: February 22, 1982
    Date of Patent: May 14, 1985
    Assignee: Advance Transformer Co.
    Inventor: Joseph A. Crawford