Patents by Inventor Gary D. Lehnhardt

Gary D. Lehnhardt 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: 6913041
    Abstract: A concrete boom hose is provided with a first end that is connected to the outermost end of a series of concrete pipes and a second end through which the flowing concrete exits. The second end is provided with an inner diameter that is smaller than the inner diameter of the first end that is connected to the concrete pipe.
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: July 5, 2005
    Assignee: Construction Forms, Inc.
    Inventors: Gary D. Lehnhardt, Rolando Altamirano
  • Patent number: 6871832
    Abstract: A shut off valve for use with a concrete delivery hose includes a single flexible cylindrical sleeve disposed within a one piece, continuous rigid casing that surrounds the hose. A gas chamber is defined between the sleeve and the casing so that when pressurized gas is forced into the chamber, the sleeve will be displaced radially inwardly to constrict the hose and stop the flow of concrete. The shut-off valve also includes a relief valve for quickly exhausting gas from the valve, and an off/on indicator for indicating open/closed positions of the valve.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: March 29, 2005
    Assignee: Construction Forms, Inc.
    Inventors: Gary D. Lehnhardt, Gordon W. Guslick, Rolando Altamirano, Gerald Biever, James H. Larson
  • Patent number: 6817591
    Abstract: A shut off valve for use with a concrete delivery hose includes a pair of flexible cylindrical sleeves disposed within a rigid casing that surrounds the hose. A gas chamber is defined between the sleeves so that when pressurized gas is forced into the chamber the inner sleeve will be displaced radially inwardly to constrict the hose and stop the flow of concrete.
    Type: Grant
    Filed: December 4, 2002
    Date of Patent: November 16, 2004
    Assignee: Construction Forms, Inc.
    Inventors: Gary D. Lehnhardt, Gordon W. Guslick
  • Publication number: 20040149942
    Abstract: A shut off valve for use with a concrete delivery hose includes a single flexible cylindrical sleeve disposed within a one piece, continuous rigid casing that surrounds the hose. A gas chamber is defined between the sleeve and the casing so that when pressurized gas is forced into the chamber, the sleeve will be displaced radially inwardly to constrict the hose and stop the flow of concrete. The shut-off valve also includes a relief valve for quickly exhausting gas from the valve, and an off/on indicator for indicating open/closed positions of the valve.
    Type: Application
    Filed: January 31, 2003
    Publication date: August 5, 2004
    Inventors: Gary D. Lehnhardt, Gordon W. Guslick, Rolando Altamirano, Gerald Biever, James H. Larson
  • Patent number: 6766570
    Abstract: A method for forming and attaching a clamping collar to a pipe configured for forming a pipe section in a concrete pumping line for carrying of fluid concrete includes the steps of placing a sleeve on the pipe to provide a heat transfer limit area between the sleeve and the pipe; welding the sleeve to the pipe; heat treating the pipe; and assembling a collar to the sleeve and welding the collar to the sleeve.
    Type: Grant
    Filed: January 8, 2002
    Date of Patent: July 27, 2004
    Assignee: Construction Forms, Inc.
    Inventors: Robert E. Klemm, Gary D. Lehnhardt
  • Patent number: 6758500
    Abstract: A coupling arrangement for permitting fluid-tight, pressurized fluid flow therethrough includes a pair of conduit members located in end-to-end alignment, each of the conduit members having a flared end. An encircling coupling unit surrounds the ends of the conduit members and has structure to tighten the coupling unit around the flared ends of the conduit members, the coupling unit having inner lateral surfaces partially defining a coupling cavity. An encircling, deformable gasket is disposed in the cavity of the coupling unit. The gasket has exterior lateral surfaces spaced from the inner lateral surfaces of the coupling unit, and interior surfaces defining an annular recess therein. A rigid ring liner is retained within the annular recess of the deformable gasket to reinforce the gasket. The flared ends of the conduit members are engaged in wedging and sealing relationship between the inner lateral surfaces of the coupling unit and the exterior lateral surfaces of the deformable gasket.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: July 6, 2004
    Assignee: Construction Forms, Inc.
    Inventor: Gary D. Lehnhardt
  • Publication number: 20040069356
    Abstract: A concrete boom hose is provided with a first end that is connected to the outermost end of a series of concrete pipes and a second end through which the flowing concrete exits. The second end is provided with an inner diameter that is smaller than the inner diameter of the first end that is connected to the concrete pipe.
    Type: Application
    Filed: October 15, 2002
    Publication date: April 15, 2004
    Inventors: Gary D. Lehnhardt, Rolando Altamirano
  • Publication number: 20030197381
    Abstract: A coupling arrangement for permitting fluid-tight, pressurized fluid flow therethrough includes a pair of conduit members located in end-to-end alignment, each of the conduit members having a flared end. An encircling coupling unit surrounds the ends of the conduit members and has structure to tighten the coupling unit around the flared ends of the conduit members, the coupling unit having inner lateral surfaces partially defining a coupling cavity. An encircling, deformable gasket is disposed in the cavity of the coupling unit. The gasket has exterior lateral surfaces spaced from the inner lateral surfaces of the coupling unit, and interior surfaces defining an annular recess therein. A rigid ring liner is retained within the annular recess of the deformable gasket to reinforce the gasket. The flared ends of the conduit members are engaged in wedging and sealing relationship between the inner lateral surfaces of the coupling unit and the exterior lateral surfaces of the deformable gasket.
    Type: Application
    Filed: January 31, 2003
    Publication date: October 23, 2003
    Inventor: Gary D. Lehnhardt
  • Publication number: 20030127854
    Abstract: A modular system for adapting a boom concrete system into a line concrete pumping system utilizes a first substantially 90 degree elbow connected to the pump outlet so that the concrete flow is directed downwardly from the outlet. A second substantially 90 degree elbow is pivotally attached to the first elbow so that the concrete flow direction can be selectively positioned in a horizontal plane. The second elbow further includes a reduced diameter at its outermost end.
    Type: Application
    Filed: December 11, 2002
    Publication date: July 10, 2003
    Inventor: Gary D. Lehnhardt
  • Publication number: 20030127612
    Abstract: A shut off valve for use with a concrete delivery hose includes a pair of flexible cylindrical sleeves disposed within a rigid casing that surrounds the hose. A gas chamber is defined between the sleeves so that when pressurized gas is forced into the chamber the inner sleeve will be displaced radially inwardly to constrict the hose and stop the flow of concrete.
    Type: Application
    Filed: December 4, 2002
    Publication date: July 10, 2003
    Inventors: Gary D. Lehnhardt, Gordon W. Guslick
  • Publication number: 20030127851
    Abstract: A locking arrangement for a pipe coupling takes the form of a spring biased pin captively and moveably mounted in a through opening formed either in an overlapping member of one of the coupling sections or the handle for movement into and out of an alignable opening formed on either the handle or on the one overlapping member of the one coupling section. The pipe coupling includes an assymetrically shaped gasket for permitting coupling of a metric end boom elbow or pipe with a heavy-duty end boom hose or pipe.
    Type: Application
    Filed: December 26, 2002
    Publication date: July 10, 2003
    Inventors: Gordon W. Guslick, Gary D. Lehnhardt
  • Patent number: 6467812
    Abstract: A pipe section for concrete includes an end coupler interconnecting to another pipe section in a flow line. The coupler has an outer clamp secured extended from the pipe end with a coupling groove. An encircling clamp has sides located in the grooves of adjacent pipe sections to lock the pipe section together. The body and pipe end form an inner recess extending from the pipe end. An insert liner has a tubular portion matching the recess, with the outer surface of the tubular portion tapered to form a gap within the recess. The insert liner has an outer flange matching the outer diameter of the body and abuts the body. The inner wall of the liner has a central transition point from which the wall tapers inwardly in opposite directions to the outer end. The body member is formed of a high strength ductile steel. The insert liner is formed of a wear resistant material having a Rockwell hardness of 80 to 90.
    Type: Grant
    Filed: December 2, 1996
    Date of Patent: October 22, 2002
    Assignee: Construction Forms, Inc.
    Inventors: Robert E. Klemm, Gary D. Lehnhardt
  • Patent number: 6375228
    Abstract: A concrete flow line made up of a plurality of end to end pipe sections with pipes connected to each other by a coupling assembly provides for carrying abrasive fluid concrete to a deposit site. The coupling assembly includes an insulating thin sleeve slid over the connecting end of the pipe and spaced from the pipe to form a heat insulating air space therebetween. The thin sleeve is welded to the pipe prior to the hardening of the pipe. After the sleeve is welded in place the inner wall of the pipe is hardened using an induction coil for concentrating of the heat within the inner wall portion in combination with a quenching unit to affect the desired hardening while maintaining an outer ductile wall portion to which the sleeve has been actually welded. A clamping collar or coupler is welded to the sleeve after hardening and forms a connecting end for receiving of a clamp unit which interconnects the adjacent pipe and pipe sections.
    Type: Grant
    Filed: March 25, 1999
    Date of Patent: April 23, 2002
    Assignee: Construction Forms, Inc.
    Inventors: Robert E. Klemm, Gary D. Lehnhardt
  • Patent number: 5379805
    Abstract: A thin wall mild carbon steel pipe for pumping concrete has a wall which has an internal diameter of five inches and a wall thickness in the range of 0.170 to 0.200. The composition of the pipe wall by weight is in percentages ranges of 0.27 to 0.34 carbon, 0.30 to 0.60 manganese, less than 0.30 silicon with only traces of phosphorus and sulfur. The pipe has an inner hardened wall portion of RC reading of about 60 and of a thickness in the range of 0.04 to 0.06 inches and a gradual transition in hardness therefrom to an outer ductile wall reading of about 30 RC. The unhardened mild carbon steel pipe is processed by progressively and successively heating axially annular portions of the pipe to a hardening temperature of 1650.degree. F. A quenching brine solution at a temperature below 50.degree. F. is immediately sprayed at a high velocity onto the progressively heated surface to reduce the temperature of the inner wall essentially instantaneously to the temperature of the brine solution.
    Type: Grant
    Filed: December 16, 1992
    Date of Patent: January 10, 1995
    Assignee: Construction Forms
    Inventors: Robert E. Klemm, Gary D. Lehnhardt
  • Patent number: 4796814
    Abstract: A semi-liquid cementitious pump nozzle unit for pumping cement, concrete, grout and other abrasive materials includes an air chamber assembly having an outer integral swivel housing. A tubular steel body has a threaded coupling for connection to a pump hose. An air chamber recess extends about the nozzle body with transfer openings located centrally of the recess. An outer air housing in a form of a simple tubular member is telescoped over the end walls and sealed thereto by O-ring seals. The opposite ends of the housing are smooth bearing surfaces. Annular bearing walls project radially outwardly by the nozzle and abutting the bearing surfaces of the housing. The bearing walls may be snap ring units releasably applied to the nozzle body. A nozzle reducer secured to the end of the nozzle body may have an appropriate end directly abutting the air/swivel housing to form a bearing wall. The outer air/swivel housing is secured with the body for a slip fit for ease of disassembly, cleaning and maintenance.
    Type: Grant
    Filed: September 9, 1987
    Date of Patent: January 10, 1989
    Assignee: Construction Forms, Inc.
    Inventors: Robert E. Klemm, Gary D. Lehnhardt