Patents by Inventor Roger J. Nelson

Roger J. Nelson 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: 4997344
    Abstract: A radial piston pump is provided with a plurality of valve/piston cartridges. Each cartridge includes the piston and at least one of the valves connecting the piston to the inlet and outlet passages of the pump. The bearings for the main rotor are pre-loaded using a threadedly adjustable end guill. Once adjusted, the end quill is held in location by a pin or the like. The rotor itself is provided with counterweights to balance the eccentric cam surface. These features allow construction of a pump housing which is substantially a single unit, rather than two pump halves. A significant reduction in the number of machined bores also is obtained.
    Type: Grant
    Filed: August 14, 1989
    Date of Patent: March 5, 1991
    Assignee: Deere & Company
    Inventors: Roger J. Nelson, Donald J. MacDonald, Arlen W. Koelling, William L. Snyder
  • Patent number: 4915595
    Abstract: A radial piston pump is provided with a plurality of valve/piston cartridges. Each cartridge includes the piston and at least one of the valves connecting the piston to the inlet and outlet passages of the pump. The bearings for the main rotor are pre-loaded using a threadedly adjustable end quill. Once adjusted, the end guill is held in location by a pin or the like. The rotor itself is provided with counterweights to balance the eccentric cam surface. These features allow construction of a pump housing which is substantially a single unit, rather than two pump halves. A significant reduction in the number of machined bores also is obtained.
    Type: Grant
    Filed: June 15, 1988
    Date of Patent: April 10, 1990
    Assignee: Deere & Company
    Inventors: Roger J. Nelson, Donald J. Macdonald, Arlen W. Koelling, William L. Snyder
  • Patent number: 4738109
    Abstract: A two stage brake valve for communicating fluid pressure to a brake assembly. The valve has a stepped cylinder formed therein in which a high volume piston and high pressure valve are slidably located. The piston and valve define high volume and high pressure chambers respectively. A set of passageways through the piston and valve communicate fluid pressure from the high volume chamber to the high pressure chamber and from the high volume chamber to a reservoir. Relief valve elements located in the passageways regulate fluid communication between the chambers and reservoir. A motion responsive relief valve comprising a ring and groove is also disclosed which provides an orifice function and facilitates refilling of the first chamber. One embodiment includes a highly compact relief assembly valve assembly having dual poppets which act to communicate fluid pressure from the first chamber to either the second chamber or the reservoir.
    Type: Grant
    Filed: November 4, 1986
    Date of Patent: April 19, 1988
    Assignee: Deere & Company
    Inventors: James A. Miller, Roger J. Nelson, Bennie J. Vaughn
  • Patent number: 4518045
    Abstract: An engine driven agricultural tractor has a hitch control system with an actuator which is responsive to a differential coolant pressure across the engine driven coolant pump.
    Type: Grant
    Filed: June 13, 1983
    Date of Patent: May 21, 1985
    Assignee: Deere & Company
    Inventor: Roger J. Nelson
  • Patent number: 4469014
    Abstract: A cylinder stop or collar includes a pair of identical mating cam members. Each cam member has a body and a pair of ramps which define cam surfaces. The ramps have slots for receiving attaching means such as bolts. Each cam member also has a slot so that it may be slid on and off the rod of a cylinder without disconnecting the cylinder.
    Type: Grant
    Filed: June 13, 1983
    Date of Patent: September 4, 1984
    Assignee: Deere & Company
    Inventor: Roger J. Nelson
  • Patent number: 4463659
    Abstract: A hydraulic cylinder stroke limiter has a valve for controlling fluid flow from a port of the cylinder. A flexible hose has one end fixed to the valve housing and the other end movably supported at the rod end of the cylinder by a pivotal bracket. A cable extends through the hose and is anchored at one end with respect to the bracket and at the other end to a poppet movable to open to close the valve. A stop is mountable on the piston rod to engage the bracket, its movement being communicated by the cable to the poppet to close the valve and prevent further rod retraction.
    Type: Grant
    Filed: October 27, 1983
    Date of Patent: August 7, 1984
    Assignee: Deere & Company
    Inventor: Roger J. Nelson
  • Patent number: 4366718
    Abstract: A bi-directional fluid flow transducer includes a hollow cylindrical housing which slidably receives a movable hollow cylindrical core which coaxially receives a fixed rod or valve member. A pair of springs are biased to urge the core to a neutral position. The core is displaced from its neutral position in the direction of fluid flow by an amount linearly proportional to the rate of fluid flow. An LVDT coil and circuit generate an output signal which represents the amount and direction of core displacement.
    Type: Grant
    Filed: January 26, 1981
    Date of Patent: January 4, 1983
    Assignee: Deere & Company
    Inventor: Roger J. Nelson
  • Patent number: 4350050
    Abstract: A fluid flow sensor includes a housing defining a flow path for fluid flow therethrough. A valve member slidably engages the housing and moves with respect to a fixed cylindrical metering member in response to fluid flow through the flow path. A spring biases the valve member to a no-flow position. A portion of the valve member engages a seat to prevent reverse fluid flow. The metering member receives one end of the valve member while a reluctive displacement transducer is received by a bore extending into the valve member from the other end.
    Type: Grant
    Filed: February 10, 1981
    Date of Patent: September 21, 1982
    Assignee: Deere & Company
    Inventor: Roger J. Nelson