Patents Assigned to Con/Span Culvert Systems, Inc.
  • Patent number: 4993872
    Abstract: A precast concrete culvert system includes a series of open bottom culvert sections each having parallel spaced vertical side walls integrally connected to an arcuate top wall having a curved inner surface with a radius of curvature at least twice the rise defined between the top center of the curved inner surface and the bottom surfaces of the side walls. The side walls rest on footers and have outer surfaces which form sharp corners with the top surface of the top wall and have a vertical height at least sixty percent and preferably between eighty and ninety percent of the rise. The vertical height is also less than fifty percent of the radius of curvature which is between twenty and fifty feet and preferably either about twenty-five or forty feet.
    Type: Grant
    Filed: August 8, 1989
    Date of Patent: February 19, 1991
    Assignee: Con/Span Culvert Systems, Inc.
    Inventor: William D. Lockwood
  • Patent number: 4854775
    Abstract: A precast concrete culvert system includes a series of open bottom culvert sections each having parallel spaced vertical side walls integrally connected to an arcuate top wall having a curved inner surface with a radius of curvature at least twice the rise defined between the top center of the curved inner surface and the bottom surfaces of the side walls. The side walls rest on footers and have outer surfaces which form sharp corners with the top surface of the top wall and have a vertical height at least sixty percent and preferably between eighty and ninety percent of the rise. The vertical height is also less than fifty percent of the radius of curvature which is between twenty and fifty feet and preferably either about twenty-five or forty feet. The end sections have vertical head walls, and the vertical side walls are adapted to connect with angularly disposed vertical concrete wing walls to provide for a smooth hydraulic flow into and through the series of the culvert sections.
    Type: Grant
    Filed: February 29, 1988
    Date of Patent: August 8, 1989
    Assignee: Con/Span Culvert Systems, Inc.
    Inventor: William D. Lockwood
  • Patent number: 4797030
    Abstract: A precast concrete culvert system includes a series of open bottom culvert sections each having parallel spaced vertical side walls integrally connected to an arcuate top wall having a curved inner surface with a radius of curvature at least twice the rise defined between the top center of the curved inner surface and the bottom surfaces of the side walls. The side walls rest on footers and have outer surfaces which form sharp corners with the top surface of the top wall and have a vertical height at least sixty percent and preferably between eighty and ninety percent of the rise. The vertical height is also less than fifty percent of the radius of curvature which is between twenty and fifty feet and preferably either about twenty-five or forty feet. The end sections have vertical head walls, and the vertical side walls are adapted to connect with angularly disposed vertical concrete wing walls to provide for a smooth hydraulic flow into and through the series of the culvert sections.
    Type: Grant
    Filed: August 17, 1987
    Date of Patent: January 10, 1989
    Assignee: Con/Span Culvert Systems, Inc.
    Inventor: William D. Lockwood
  • Patent number: 4687371
    Abstract: A culvert section includes vertical parallel spaced concrete side walls integrally connected by an arcuate concrete top wall having a curved inner surface with a radius of curvature at least twice the rise defined between the top center of the curved inner surface and the bottom surfaces of the side walls. The side walls have flat outer surfaces which form corners with the top surface and have a vertical height preferably between eighty and ninety percent of the rise. The vertical height is also less than fifty percent of the radius of curvature which is between twenty and thirty feet and preferably about twenty-five feet. The vertical side walls are adapted to connect with angularly disposed vertical concrete wing walls to provide for a smooth hydraulic flow into and through a series of the culvert sections.
    Type: Grant
    Filed: April 17, 1986
    Date of Patent: August 18, 1987
    Assignee: Con/Span Culvert Systems, Inc.
    Inventor: William D. Lockwood