Patents by Inventor C. Warren Duncan

C. Warren Duncan 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: 8647030
    Abstract: A core drilling system is disclosed herein in which a torque tube has a groove or keyway which receives a rotating wheel or key to prevent a transmission box and motor from rotating during drilling operation. As such, the operator does not need to hold a stabilizing arm to resist counter rotational forces during the drilling process. The operator may focus on the hole to be cut in a substrate. Additionally, a torque tube stabilizing leg assembly may be secured to the free distal end portion of the torque tube.
    Type: Grant
    Filed: June 7, 2010
    Date of Patent: February 11, 2014
    Inventors: C. Warren Duncan, Anders Johnsen
  • Publication number: 20110135412
    Abstract: A core drilling system is disclosed herein in which a torque tube has a groove or keyway which receives a rotating wheel or key to prevent a transmission box and motor from rotating during drilling operation. As such, the operator does not need to hold a stabilizing arm to resist counter rotational forces during the drilling process. The operator may focus on the hole to be cut in a substrate. Additionally, a torque tube stabilizing leg assembly may be secured to the free distal end portion of the torque tube.
    Type: Application
    Filed: June 7, 2010
    Publication date: June 9, 2011
    Inventors: C. Warren Duncan, Anders Johnsen
  • Patent number: 7703856
    Abstract: A manhole cover frame removal apparatus has a ring-shaped base with a circular track thereon and a saw mounting framework disposed atop the base. Rollers allow the saw mounting framework to advance in rotation about aligned vertical axes of the frame and the base. A saw mounting arm is joined to the framework and may be raised and lowered and locked in the raised position. A saw carriage is mounted on the saw arm for reciprocal movement toward and away from a saw arm hinge axis. A single saw motor is mounted on the carriage and can be immobilized at selected angles. Separate horizontal-cut and vertical-cut saw blades are alternatively and interchangeably attached to the saw blade rotor.
    Type: Grant
    Filed: August 31, 2006
    Date of Patent: April 27, 2010
    Inventor: C. Warren Duncan
  • Patent number: 7658242
    Abstract: A hole coring system for drilling large diameter holes with a handheld tool. The drill bit is guided by a mandrel attached to the concrete and serves as a central guidepost that ensures precise centering of the drill bit. Commonly available tools may be used to rotate the drill bit. A lever arm may be attached to the tool and used to resist any torquing action. Additionally, a brace may be attached to the lever arm which may be used to resist any torquing action.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: February 9, 2010
    Inventor: C. Warren Duncan
  • Patent number: 7484578
    Abstract: An apparatus for drilling holes in a substrate wherein a mandrel is anchored to the substrate. A hollow drill bit rotates about the mandrel via a drive motor and is a guided along a length of the mandrel.
    Type: Grant
    Filed: December 27, 2006
    Date of Patent: February 3, 2009
    Assignee: U.S. Saws, Inc.
    Inventor: C. Warren Duncan
  • Publication number: 20080179105
    Abstract: A hole coring system is provided that greatly stabilizes a tubular core drill bit for drilling into concrete or other materials enabling large diameter holes to be drilled with a handheld tool. The drill bit is guided by a mandrel which is attached to the concrete. The mandrel serves as a central guidepost that ensures that a relatively large diameter, tubular core drill bit remains precisely centered relative to the guide mandrel. This enables the operator to use a commonly available tool to rotate the drill and apply drill pressure only. The motor may rotate the drill bit via a gear box. The gear box may have a lever arm which may be used to resist any torquing action of the gear box due to the friction between the drill bit and the concrete. Additionally, in the event the motor's housing is not fixed to the gearbox and allowed to rotate, a brace may be attached to the lever arm which may be used to resist any torquing action of the motor's housing due to the friction between the drill bit and the concrete.
    Type: Application
    Filed: January 17, 2008
    Publication date: July 31, 2008
    Inventor: C. Warren Duncan
  • Patent number: 7082656
    Abstract: A tool for beveling the end of a pipe is comprised of a hollow, tubular body having a central, longitudinal axis of rotation, an inboard coupling end, and an opposite outboard working end. A plurality of longitudinally spaced, transversely directed latching pin bores of equal size are defined through the wall of the tubular body. A core member is disposed coaxially within the tubular body. The core member includes a beveling cutter head and a longitudinal stem having a radially inwardly directed, circumferential latch position groove. A transversely oriented latching pin is engaged in a selected one of the latching pin bores in the body and with the latch position groove of the core stem. This allows alternative selection of each of the latch position bores for insertion of the latching pin. The particular bore selected determines the longitudinal position of the core stem latch position groove within the body that will be aligned with the latching pin.
    Type: Grant
    Filed: April 19, 2004
    Date of Patent: August 1, 2006
    Inventors: C. Warren Duncan, Bill Glynn, Bruce Root
  • Patent number: 6238277
    Abstract: A multidisc floor grinder is constructed as a wheeled device that may be moved about the floor by means of a handle. The chassis of the floor grinder supports a bearing housing on gimbals that allow the bearing housing to vary in orientation as the device is moved across an uneven floor. The gimbals are aligned to allow rotation of the bearing housing about a bearing housing axis that is parallel to the floor. The bearing housing supports a main drive shaft which extends downwardly from the bearing housing. The main drive shaft is rotatable relative to the bearing housing within its bearings. A grinder mounting frame is rotatably mounted about the main drive shaft and is supported therefrom. The grinder mounting frame is driven in rotation about the main drive shaft at a greatly reduced speed relative to the rotation of the main drive shaft.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: May 29, 2001
    Inventors: C. Warren Duncan, William D. Glynn
  • Patent number: 5850889
    Abstract: A single post anchor for lifelines is provided with a generally elongate member having at one end a means configured to engage about a structural member and having a clamping assembly which acts on another surface of the structure to secure the anchor in place. A swivel is provided as part of the anchor to which a retractable lifeline device or the like is attached.
    Type: Grant
    Filed: September 15, 1997
    Date of Patent: December 22, 1998
    Inventors: John Rexroad, C. Warren Duncan
  • Patent number: 5791979
    Abstract: An improved vacuum shroud is provided for a grinding tool. The vacuum shroud employs a resilient bonnet with a central, axial opening therein for receiving a rotary grinder shaft therethrough. The bonnet is formed of a resilient, flexible, plastic material having a roof with a skirt at the periphery of the roof that laterally surrounds the grinder disk. A reinforcement plate at the undersurface of the roof protects the roof of the vacuum shroud when the grinder body is tilted at an incline toward a work surface so as to exert a greater pressure on one portion of the grinding face of the grinding disk than another. The peripheral region of the roof of the bonnet is flexible enough to permit orientation of the grinder tool body at various angles of inclination relative to the work surface while still maintaining contact between the work surface and the lower edge of the bonnet skirt throughout its entire length.
    Type: Grant
    Filed: March 17, 1997
    Date of Patent: August 11, 1998
    Inventors: C. Warren Duncan, William D. Glynn
  • Patent number: 5782043
    Abstract: A system is provided for relieving the downwardly acting load on a structural column, such as a reinforced concrete column supporting a roadway, bridge, overpass, or other massive structure. Horizontally oriented keyways are formed into the concrete column on transversely opposite sides thereof and at the same elevation thereon. The keyways are of rectangular cross section. Clamps likewise having vertical bearing surfaces and keys that extend horizontally with a corresponding rectangular cross section are clamped against the transversely opposite sides of the columns so that keys project into the keyways. A load bearing support system is positioned beneath the clamps. The bolts are torqued to tighten the clamps and hydraulic jacks are inserted in between the lowermost clamps and the load-bearing support structure to exert vertically upwardly acting forces against the clamps. These vertical forces counter the load on the column, thereby preloading the column.
    Type: Grant
    Filed: November 19, 1996
    Date of Patent: July 21, 1998
    Inventors: C. Warren Duncan, Richard G. Meehan
  • Patent number: 5074044
    Abstract: An attachment is provided for a saw or other power tool having a rotary shaft and a circular blade mounted on the shaft. A substitute saw blade guard is fastened on the saw housing to define a dust confining channel about the periphery of a portion of the circular rotary saw blade. A shaft extension is fastened to the exposed tip of the shaft and an impeller is fastened to the shaft extension outside of the dust confining channel. A bonnet with an internal dust transfer passageway is secured relative to the dust guard to confine the impeller within an impeller enclosure. Operation of the rotary blade causes the impeller to rotate to create a suction, thereby drawing air and dust from the channel about the periphery of the rotary blade and into the vortex created at the axial center of the impeller. The impeller discharges air laden with dust from a discharge outlet in the impeller bonnet.
    Type: Grant
    Filed: April 26, 1991
    Date of Patent: December 24, 1991
    Inventors: C. Warren Duncan, William D. Glynn