Patents by Inventor John L. Spencer

John L. Spencer 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: 5288168
    Abstract: An improved method and apparatus for waterproofing soil utilizing a flexible plastic sheet for providing a water barrier provides a system for readily detecting the presence of holes in the plastic material. The sheet includes a plastic layer which may be rendered electrically conductive by embedding conductive particles within it. The integrity of the sheet may then be monitored by establishing an electric field across the sheet and monitoring for sparks between the conductive plastic layer and a probe. Reliable and economical testing is possible, even in situation where electrical leak testing was not previously feasible.
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: February 22, 1994
    Assignee: Gundle Lining Construction Corporation
    Inventor: John L. Spencer
  • Patent number: 5140848
    Abstract: A plastic liner pipe penetration adapter designed for sealably penetrating a moisture impervious thermoplastic sheet or liner, particularly suitable for lining reservoirs, hazardous waste disposal sites, outdoor fluid containment areas and other similar applications, without damaging the sealing characteristics of the liner and which also allows field testing of the sealability of the liner after the installation of the adapter. In one embodiment, an inner tubular housing member defining a passage through the liner is inserted through a plate and connected thereto. An outer tubular housing member is coaxially aligned about the inner tubular housing member and sealably welded at a first end to the plate. An annular end piece is inserted over the inner tubular housing member in order to seal a second end of the outer tubular housing member to the inner tubular housing member, thereby creating a pressure test chamber between the tubular housing members and the annular end piece.
    Type: Grant
    Filed: August 17, 1990
    Date of Patent: August 25, 1992
    Assignee: Gundle Lining Construction Corporation
    Inventor: John L. Spencer
  • Patent number: 4845194
    Abstract: An improvement in the large-scale recovery of vancomycin-type glycopeptide antibiotics which comprises (1) commingling the fermentation medium in which the antibiotic is produced with a polystyrene divinylbenzene resin such as Dow XFS-43278.00, (2) separating the resin from the medium and (3) eluting the antibiotic from the resin. This improvement avoids preliminary filtration and pH adjustment of the broth, simplifies waste-disposal problems and eliminates antibiotic losses due to mycelial adsorption and filtration.
    Type: Grant
    Filed: February 27, 1987
    Date of Patent: July 4, 1989
    Assignee: Eli Lilly and Company
    Inventors: Suzanne L. E. Glass, Charles W. Johnson, John L. Spencer