Patents by Inventor Duane D. Robertson

Duane D. Robertson 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: 6810587
    Abstract: A combined clamping and cutting tool for manually cutting plastic pipes. The cutting portion includes a pair of elongated members pivotally mounted to each other with each elongated member having a handle section and a cutting section. Cutting wheels are rotatably mounted to each cutting section. The clamping portion includes at least three members with the first and second members pivotally mounted to each other and the second and third members pivotally mounted to each other. The first and second clamping sections respectively have a pair of spaced-apart, parallel legs that firmly and slidably receive the cutting sections of the cutting portion therebetween. Interlocking tracks are also provided to maintain the clamping and cutting portions together during use and to provide an interaction between the two portions to aid in opening them to receive the pipe.
    Type: Grant
    Filed: August 15, 2003
    Date of Patent: November 2, 2004
    Inventor: Duane D. Robertson
  • Publication number: 20040070196
    Abstract: A fitting for lawn sprinkler systems which have pipes of rigid, plastic such as polyvinylchloride (PVC). The fitting includes a main body with a tubular section affixed to it at about a 30 degree angle. The tubular section has an outer surface with at least a pair of posts extending outwardly from it in opposite directions. In use, the main body of the fitting can be mounted onto the outer surface of the pipe and portions of a coring tool can then be positioned substantially about the opposing posts to anchor the tool to the fitting and aid the tool in coring the pipe.
    Type: Application
    Filed: October 10, 2002
    Publication date: April 15, 2004
    Inventor: Duane D. Robertson
  • Patent number: 6370780
    Abstract: A spring-biased cutting tool for plastic pipes. The tool includes two elongated members pivotally connected to each other in a scissors-like manner. Each elongated member has a handle portion and a jaw portion with one jaw portion including a knife blade and the other an anvil. To assemble the elongated members, one of them is provided with a central aperture or hole through which the other member can be passed to form the scissors-like shape. A leaf spring in then clipped at one end over an edge portion of the aperture and extends across to abut against the other elongated member and bias the handles of the tool apart and the jaws of the tool is open to receive a pipe to be cut.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: April 16, 2002
    Inventors: Duane D. Robertson, Rodney G. May, Kit N. Robertson
  • Publication number: 20020033599
    Abstract: Replacement fittings for substantially rigid pipes. Each fitting preferably includes a main body with telescoping, sleeve members mounted on it. The sleeve members can be individually slid along the main body but cannot be removed from it. In this manner, the preferred fittings of the present invention can be handled as a single unit and all of the linked pieces will stay together and cannot be inadvertently left behind. They also cannot be accidentally lost or dropped on the way to the job site or during the repair operation. The various pieces of the fittings employ tapering surfaces that not only ensure the pieces will stay together while the fittings are being manipulated into position but also aid in creating the strongest bonds and seals with the pipes.
    Type: Application
    Filed: November 19, 2001
    Publication date: March 21, 2002
    Inventor: Duane D. Robertson
  • Patent number: 6318761
    Abstract: Replacement fittings for substantially rigid pipes. Each fitting preferably includes a main body with telescoping, sleeve members mounted on it. The sleeve members can be individually slid along the main body but cannot be removed from it. In this manner, the preferred fittings of the present invention can be handled as a single unit and all of the linked pieces will stay together and cannot be inadvertently left behind. They also cannot be accidentally lost or dropped on the way to the job site or during the repair operation. The various pieces of the fittings employ tapering surfaces that not only ensure the pieces will stay together while the fittings are being manipulated into position but also aid in creating the strongest bonds and seals with the pipes.
    Type: Grant
    Filed: November 26, 1999
    Date of Patent: November 20, 2001
    Inventor: Duane D. Robertson
  • Patent number: 5487571
    Abstract: A pipe fitting for a flexible pipe such as used in lawn sprinkler systems. The fitting includes a pipe sealing portion and a pipe gripping portion. The pipe sealing portion has a smooth, seamless cylindrical surface to form a strong, watertight seal with the inner surface of the pipe. The pipe gripping portion is spaced from the sealing portion and includes a cylindrical surface with two rows of spikes extending axially along it. The rows are spaced 180 degrees from each other about the cylindrical surface and the cylindrical surface of the gripping portion has a smaller diameter than the cylindrical surface of the sealing portion. In use, the flexible pipe is forced to assume a substantially elliptical shape as it passes over the rows of progressively taller spikes. The pipe can then be crimped if desired to embed the spikes into the wall of the pipe and preferably to drive at least some of the spikes completely through the pipe wall.
    Type: Grant
    Filed: August 29, 1994
    Date of Patent: January 30, 1996
    Inventor: Duane D. Robertson
  • Patent number: 4956916
    Abstract: A pipe saddle for providing a reliable connection to a pipe. The present invention uses a barb seal which embeds within the surface of the pipe to lock the pipe saddle in place and prevent leakage. The barb seal is formed from the material of the pipe saddle so that no deterioration occurs. The barb seal has an oval shape to provide better sealing capabilities. T-bolt connectors allow the device to be individually tightened on each side of the pipe while allowing the body portions of the saddle to be pivotally opened yet maintained as a single unit to allow easy implementation.
    Type: Grant
    Filed: August 22, 1988
    Date of Patent: September 18, 1990
    Inventor: Duane D. Robertson
  • Patent number: 4789189
    Abstract: A pipe saddle for providing a reliable connection to a pipe. The present invention uses a barb seal which embeds within the surface of the pipe to lock the pipe saddle in place and prevent leakage. The barb seal is formed from the material of the pipe saddle so that no deterioration occurs. The barb seal has an oval shape to provide better sealing capabilities. T-bolt connectors allow the device to be individually tightened on each side of the pipe while allowing the body portions of the saddle to be pivotally opened yet maintained as a single unit to allow easy implementation.
    Type: Grant
    Filed: February 9, 1987
    Date of Patent: December 6, 1988
    Inventor: Duane D. Robertson
  • Patent number: 4336652
    Abstract: A cutting tool for cutting flexible plastic conduit, formed by a pair of handled jaws pivotally connected intermediate their ends. One jaw is box shaped in cross-section and forms a handle which supports a knife blade, which has a longitudinal cutting edge. The other jaw is generally channel-shaped in cross-section and forms a handle with a semi-circular concave anvil at one end. The anvil has an axially extending slot therein for receiving the cutting edge of the knife blade when the handles are closed together with the box-shaped handle nested within the channel-shaped handle. A conduit supported in the semi-circular anvil is cut by the knife blade as the handles are squeezed together.
    Type: Grant
    Filed: August 1, 1980
    Date of Patent: June 29, 1982
    Inventor: Duane D. Robertson
  • Patent number: 3980325
    Abstract: A fitting, for pipe of flexible plastic material, having improved sealing and mechanical holding characteristics. The fitting includes a main body having an external screw thread terminating at a shoulder from which a coaxial, reduced-diameter, nipple projects. Annular saw tooth or buttress ribs on the nipple are dimensioned to have a slip fit into the interior of a plastic pipe section. A collet is slideable on the exterior of the pipe section into abutment with the shoulder and is radially compressed by a collet sleeve threaded onto the external threads of the fitting body. Axial slots in the collet open alternately at opposite ends of the collet so that radial compression is achieved over the entire length of the collet. Saw toothed or buttress annual ribs on the collet interior bite into the exterior surface of the pipe section in opposition to the ribs on the inserted nipple, the pipe wall being thereby radially clamped between the collet and nipple.
    Type: Grant
    Filed: July 29, 1974
    Date of Patent: September 14, 1976
    Assignees: Duane D. Robertson, Frank J. Progar
    Inventor: Duane D. Robertson
  • Patent number: D266736
    Type: Grant
    Filed: August 1, 1980
    Date of Patent: November 2, 1982
    Inventor: Duane D. Robertson