Patents by Inventor Derek H. Greenhill

Derek H. Greenhill 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: 4295754
    Abstract: There is disclosed a temporary structure for use in exhibition stands and the like, comprising a framework comprising rectangular frame units each comprising two parallel vertical tubes and two horizontal spars, each in the form of an H with a much elongated cross member and much shortened uprights each of which provides two plugs, respectively above and below the cross member, two said plugs of each said horizontal spar being engaged in respective sockets afforded by the ends of respective ones of the two vertical tubes of the respective frame unit.In an extended structure each horizontal spar may form the lower spar of one such rectangular frame unit and the upper spar of an adjoining lower frame unit. Spring collets may be fitted around the plugs and within the sockets in which the plugs are inserted the colletts having cutting edges to score the socket walls, and having internal projections fitting in recesses in the plugs whereby a firm non-rotatable connection can be obtained.
    Type: Grant
    Filed: March 29, 1979
    Date of Patent: October 20, 1981
    Assignee: Marler Haley Exposystems Limited
    Inventors: Christopher J. Ashton, Andrew C. Diamond, Derek H. Greenhill