Patents by Inventor Duane D. Krohn

Duane D. Krohn 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: 6390386
    Abstract: An improved reversible airless spray tip inhibits dripping, spitting, and undesirable paint accumulation on the spray guard, while improving safety. A positioning detent on the spray tip carrier handle snaps positively into place when a nozzle carrier is rotated into spray position, indicating that the tip is properly positioned for spraying. A spray guard with airfoil-like cross-members protects the user from injury while they inhibit turbulence and prevent paint accumulation. An improved piston seal has a slot-like fluid passage, which is preferably substantially rectangular in cross section. A rearward end of the piston seal is sealed by a resilient ring compressed directly against the face of an attached spray gun. An improved tip retainer is expanded by swaging after insertion, which forces a lip into a mating slot. The tip retainer also has an expanded chamber which diffuses reverse fluid flow for safety.
    Type: Grant
    Filed: June 7, 2001
    Date of Patent: May 21, 2002
    Assignee: Durotech Company
    Inventors: Duane D. Krohn, Miroslav Liska
  • Publication number: 20020014541
    Abstract: An improved reversible airless spray tip inhibits dripping, spitting, and undesirable paint accumulation on the spray guard, while improving safety. A positioning detent on the spray tip carrier handle snaps positively into place when a nozzle carrier is rotated into spray position, indicating that the tip is properly positioned for spraying. A spray guard with airfoil-like cross-members protects the user from injury while they inhibit turbulence and prevent paint accumulation. An improved piston seal has a slot-like fluid passage, which is preferably substantially rectangular in cross section. A rearward end of the piston seal is sealed by a resilient ring compressed directly against the face of an attached spray gun. An improved tip retainer is expanded by swaging after insertion, which forces a lip into a mating slot. The tip retainer also has an expanded chamber which diffuses reverse fluid flow for safety.
    Type: Application
    Filed: June 7, 2001
    Publication date: February 7, 2002
    Applicant: DUROTECH COMPANY
    Inventors: Duane D. Krohn, Miroslav Liska
  • Patent number: 6264115
    Abstract: An improved reversible airless spray tip inhibits dripping, spitting, and undesirable paint accumulation on the spray guard, while improving safety. A positioning detent on the spray tip carrier handle snaps positively into place when a nozzle carrier is rotated into spray position, indicating that the tip is properly positioned for spraying. A spray guard with airfoil-like cross-members protects the user from injury while they inhibit turbulence and prevent paint accumulation. An improved piston seal has a slot-like fluid passage, which is preferably substantially rectangular in cross section. A rearward end of the piston seal is sealed by a resilient ring compressed directly against the face of an attached spray gun. An improved tip retainer is expanded by swaging after insertion, which forces a lip into a mating slot. The tip retainer also has an expanded chamber which diffuses reverse fluid flow for safety.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: July 24, 2001
    Assignee: Durotech Company
    Inventors: Miroslav Liska, Duane D. Krohn
  • Patent number: 5441297
    Abstract: The power unit cart of the present invention provides for the quick, efficient, and easy replacement of either an engine or an electrical motor power unit as the power source for a cart-mounted spray painting pumping system. The power unit cart includes a main frame which has a partial tubular socket and an axial alignment member having a vertical support tab. The axial alignment member and the partial tubular socket pivotally and slidably engage a universal mounting base which includes a tubular member and an L-shaped bracket. The power unit is attached to the upper face of the universal mounting base. The axial alignment member and the partial tubular socket, in conjunction with an anchoring device, releasably and adjustably couple the universal mounting base and power unit to the power unit cart. The anchoring device is then attached to the L-shaped bracket for adjustment of the tension of a belt drive.
    Type: Grant
    Filed: November 10, 1993
    Date of Patent: August 15, 1995
    Assignee: Graco Inc.
    Inventors: Duane D. Krohn, George R. Jones
  • Patent number: 5346370
    Abstract: A liquid pumping system adaptable for connection to either an electrical drive motor or an internal combustion engine, wherein a generator and clutch is coupled to the driving source, and a pressure sensing switch is connected to the generator rotor to selectively provide voltage to a rectifier circuit and field winding for the clutch. The energization of the field winding causes the clutch to actuate and thereby causes a mechanical coupling to a reciprocable pump for developing liquid pressure.
    Type: Grant
    Filed: November 8, 1993
    Date of Patent: September 13, 1994
    Assignee: Graco Inc.
    Inventor: Duane D. Krohn
  • Patent number: 5292232
    Abstract: A self-contained liquid manifold attachable to a drive mechanism for a reciprocable pump, the manifold having a pumping cylinder, pressure transducer, pressure control mechanism, drain valve and control mechanism attached thereto, and liquid delivery outlets all forming a part thereof. The manifold and its associated components are removable from the reciprocable drive mechanism by detaching two fasteners. The pressure transducer and control mechanism includes a piston and cylinder removably indexed in a manifold bore, and an electrical switch in an adjacent housing with a ball bearing on the piston and a push rod resting on the ball bearing, the other push rod end constrained by a ball and spring combination.
    Type: Grant
    Filed: January 19, 1993
    Date of Patent: March 8, 1994
    Assignee: Graco Inc.
    Inventors: Duane D. Krohn, Dean L. Schaffran
  • Patent number: 5076761
    Abstract: A DC motor drive system for mechanically linking to a reciprocable pump, having safety circuits for disconnecting power from the system upon detection of excessive line voltage variations, excessive line current variations, excessive pressure demands, and electrical and mechanical faults which may occur in system operation.
    Type: Grant
    Filed: June 26, 1990
    Date of Patent: December 31, 1991
    Assignee: Graco Inc.
    Inventors: Duane D. Krohn, Greg M. Gibbons
  • Patent number: 4722230
    Abstract: A diaphragm pump is provided for pumping paint and similar substances at relatively elevated pressures (300 psi). A pressure sensor is provided for operating the pump in order to maintain the desired pressure. The pressure sensor is located adjacently first outlet passage and is provided with a deflector which deflects the fluid in the outlet passage over the surface of the sensor diaphragm. By providing continuous flow over the face of the sensor diaphragm, paint and similar substances are prevented from drying and/or clogging thereby preventing erratic operation or failure of the device. The connecting rod which is attached to the diaphragm has an outwardly extending and downwardly tapering support surface which supports the diaphragm when under the elevated pressures of which this unit is capable of operation. An upper support member is also provided for further support.
    Type: Grant
    Filed: May 29, 1986
    Date of Patent: February 2, 1988
    Assignee: Graco Inc.
    Inventor: Duane D. Krohn
  • Patent number: 4692048
    Abstract: A modular pressure feed roller applicator to fit about a double curved liquid delivery tube having modular paint distribution sections held adjacently between two end caps; the modular sections having inner grooves and outer slots cooperatively distributing paint to the inner surface of a permeable roller sleeve for application to the surface being painted.
    Type: Grant
    Filed: June 9, 1986
    Date of Patent: September 8, 1987
    Assignee: Graco Inc.
    Inventors: Duane D. Krohn, Allan Boogerman
  • Patent number: 4652024
    Abstract: A telescoping handle and liquid pressure conduit concentrically positioned inside the handle, with a liquid seal holder affixed to an outer part of the pressure conduit, and a resilient sealing member in the seal holder to sealingly engage against an inner part of the pressure conduit, so as to permit simultaneous telescoping of the outer handle and the inner pressure conduit.
    Type: Grant
    Filed: May 12, 1986
    Date of Patent: March 24, 1987
    Assignee: Graco Inc.
    Inventor: Duane D. Krohn
  • Patent number: 4397610
    Abstract: A reciprocable liquid pump driven by a direct current electric motor wherein the motor drive voltage, and thereby pump reciprocation, and output pressure, is selectively controlled by a circuit including an electromechanical transducer coupled in pressure sensing relation to the liquid pump output, a manually operable pressure set point switch, and a silicon-controlled rectifier circuit.
    Type: Grant
    Filed: March 9, 1981
    Date of Patent: August 9, 1983
    Assignee: Graco Inc.
    Inventor: Duane D. Krohn
  • Patent number: 4323741
    Abstract: Apparatus is disclosed for sensing fluid pressure by mechanical flexure of a tube according to the principles of the Bourdon tube, wherein the tube forms a part of the fluid flow path, and where the pressure may be sensed during both dynamic and static fluid flow conditions.
    Type: Grant
    Filed: May 27, 1980
    Date of Patent: April 6, 1982
    Assignee: Graco, Inc.
    Inventor: Duane D. Krohn
  • Patent number: 4081904
    Abstract: A lightweight, compact roving cutter for chopping fiberglass roving into short fiber segments, and used in conjunction with a hand-held resin spray gun, has a cutter roller carrying a plurality of blades, a back-up roller cooperating with the cutter roller and the blades thereof for breaking or cutting the roving, and an idler roller cooperating with the back-up roller for feeding roving between the cutter and the back-up roller. The back-up roller is mounted for movement toward and away from both the cutter and the idler rollers in substantially equal increments relative to each, and a positive displacement adjusting means is connected with the back-up roller for controlling the clearance between the back-up roller and both the cutter and the idler rollers, the adjusting means including a manually operable portion remote from said cutter, whereby an operator may conveniently and accurately adjust the clearances between the rollers while the cutter is operating.
    Type: Grant
    Filed: October 26, 1976
    Date of Patent: April 4, 1978
    Assignee: Binks Manufacturing Company
    Inventors: Duane D. Krohn, Samuel W. Culbertson
  • Patent number: 4009971
    Abstract: A double acting pump is operated by a crank that is powered through a gear train driven by an electric motor. An adjustable pressure sensing device is used to control operation of the pump. A single motor, double pump embodiment is also described.
    Type: Grant
    Filed: August 27, 1974
    Date of Patent: March 1, 1977
    Assignee: Binks Manufacturing Company
    Inventors: Duane D. Krohn, Samuel W. Culbertson
  • Patent number: 4001935
    Abstract: A light weight, compact roving cutter for chopping fiberglass roving into short fiber segments, and used in conjunction with a hand-held resin spray gun, has a mounting plate containing an air inlet port for driving an air motor carried thereon, a snap-on cutter rotor or roller driven by the air motor and carrying a plurality of blades secured by single fastening means, a friction roller cooperable with the cutter roller and blades thereof for breaking or cutting the roving, means accessible to the operator for adjusting the clearance between the rollers and the contact of the friction roller with the blades while the cutter is operating, and means for matching the discharge pattern of the cut segments of roving to the spray pattern of the resin spray gun, including air jet means supplied with pressurized air separate from that supplied to the motor.
    Type: Grant
    Filed: June 12, 1975
    Date of Patent: January 11, 1977
    Assignee: Binks Manufacturing Company
    Inventors: Duane D. Krohn, Samuel W. Culbertson