Patents by Inventor Frederick H. Drury

Frederick H. Drury 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: 4199866
    Abstract: The invention provides a dental amalgamator which prevents mercury vapor, given off during amalgamation, from polluting the air in the neighborhood of the amalgamator. The amalgamator comprises a casing carrying a capsule holder and a drive means for the holder, a lid movable to a closed position in which it cooperates with the casing to form an enclosure for a capsule held by the holder, the enclosure having air inlets allowing air to flow from the atmosphere into the enclosure. A vacuum pump is arranged to communicate with the enclosure via a mercury filter medium, so that during amalgamation air is drawn into the enclosure, over the capsule, and then through the mercury filter where mercury vapors are removed.
    Type: Grant
    Filed: June 20, 1977
    Date of Patent: April 29, 1980
    Assignee: Weatherford Oil Tool Co., Ltd.
    Inventor: Frederick H. Drury
  • Patent number: 4074900
    Abstract: A capsule holder for a dental amalgamator which holds a capsule firmly for high speed amalgamation but which allows easy insertion and removal. The holder has a body with a spring containing cavity at one end capable of receiving a first end of a capsule when this is inserted at an angle to the axis of the recess, and at the other end of the body there is provided a pivotable retainer for the second end of the capsule. The retainer has a concave surface which in a first position of the retainer receives the second end of the capsule when the first end has been inserted into the cavity with little compression of the spring, and the retainer is pivotable in an over-center manner to move the capsule against the spring force and into a second position in which the capsule is held firmly between the spring and the retainer, the retainer being prevented from moving beyond this second position.
    Type: Grant
    Filed: January 11, 1977
    Date of Patent: February 21, 1978
    Assignee: Weatherford Oil Tool Company, Ltd.
    Inventor: Frederick H. Drury