Patents by Inventor Donald W. Danforth

Donald W. Danforth 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: 6302342
    Abstract: A pulper has a circular rotor that carries a set of peripheral blades that rotate within a stator having a set of peripheral lobes that interact with the peripheral blades as they rotate to reduce and defiber materials, e.g., to produce pulp slurries for paper-making. A cone assembly is mounted over the center of the rotor on a base plate. The cone assembly includes a blade that extends across the common axis of rotation of the base plate and the rotor and projects into a tank beyond the height of the peripheral blades and the stator lobes. A support structure, preferably in the form of a “cone”, supports the blade. The cone preferably has a pyramidal structure and in one form extends sufficiently far up the blade so that, typically, no more than 2 to 3 inches of the blade project above the outer surface of the cone. The blade has a triangular structure terminating in a central apex for use in reducing slabs of large sheet materials such as reel broke.
    Type: Grant
    Filed: January 5, 2000
    Date of Patent: October 16, 2001
    Assignee: Bolton-Emerson Americas, Inc.
    Inventors: Donald W. Danforth, Glen I. Urquhart
  • Patent number: 6053441
    Abstract: To defiber a wide variety of materials, rotor and stator constructions are varied 1) to increase the agitation of stock in a tank or 2) to increase defibering effectiveness and increase flow rate through a recirculation line or to downstream equipment. To increase agitation, lobes of the stator are configured and sized to reduce the stator-rotor interface below 50% of its maximum possible value. To increase defibering effectiveness and increase the recirculation flow rate, the stator lobes are configured and sized so the stator area at the interface exceeds 50% of its maximum possible value. These lobe area changes are made in a way that also preserves a desired acquisition angle on cutting edges on rotor for the given material so that the lobes reliably "acquire" and reduce the stock. To increase homogeneity of treatment, deflectors on the stator and/or rotor require that all the stock traverses the defibering interface between peripheral teeth on the rotor and opposed stator bars.
    Type: Grant
    Filed: September 4, 1997
    Date of Patent: April 25, 2000
    Assignee: Bolton-Emerson Americas, Inc.
    Inventors: Donald W. Danforth, Glen I. Urquhart
  • Patent number: 4554051
    Abstract: A standpipe is connected into a fiber processing system such as a pressurized stock line of a paper making system, containing refined stock, or unrefined pulp, at operating consistencies. Automatic controls cycle a measurement chamber, in the standpipe, through intake measure and exhaust. An imperforate plate mounted across the measurement chamber has at least one hole of predetermined cross dimension, or diameter, substantially equal to the relative length of fiber desired. Automatic timing establishes a set intake time for slurry, or suspension, to pass through the hole and contact lower and/or upper liquid level sensors, or other level indicators, in the chamber. Instantaneous, periodic read out is provided to indicate "too short", "too long" or "correct length" with each cycle. Differential pressure, across the hole, or orifice during measure, as well as approach velocity, is appropriately controlled.
    Type: Grant
    Filed: May 16, 1984
    Date of Patent: November 19, 1985
    Assignee: Bolton-Emerson, Inc.
    Inventor: Donald W. Danforth
  • Patent number: 4482095
    Abstract: A vortical circulation pulper, of the type designed to pulp difficult to defiber stock, and having a rotor revolving within a stator, in one wall of a pulp container, to circulate a charge in a path within the container, a rotor/stator, stock reduction, interface alongside the path for reducing the size of chunks to smaller pieces and a rotor/stator stock attrition interface in rear of said stock reduction interface on the path to receive and defiber said smaller pieces is provided with a bidirectional rotor and a bidirectional stator, both having symmetrical, generally, isosceles triangle shaped peaks and valleys therearound. Rotation of the rotor can thus be reversed when its stock reduction edges wear down and such reverse rotation, resharpens the worn edges.
    Type: Grant
    Filed: September 23, 1982
    Date of Patent: November 13, 1984
    Assignee: Bolton-Emerson, Inc.
    Inventor: Donald W. Danforth
  • Patent number: 4365761
    Abstract: A vortical circulation type pulper has a bladed and channelled rotor and an annular bladed and channeled stator mounted in a side, or bottom, wall, the rotor and annular stator forming a truncated conical attrition interface with the small end receiving stock for passage through the interface to the large end and thence for discharge or recirculation. Rotor/stator clearance at rest, is about 15/1000 of an inch. The stator is provided with an annular, pattern of alternate, triangular acquisition valleys and bladed and channeled peaks, each peak having an acquisition edge in the path of the stock reduction, edges of the rotor vanes so that the stock is reduced by the scissors-like contact of stock reduction edges of the vanes with the acquisition edges of the stator peaks in a stock reduction interface until sufficiently defibered to enter the truncated conical, bladed and channeled rotor/stator attrition interface for further treatment and recirculation or discharge.
    Type: Grant
    Filed: March 6, 1980
    Date of Patent: December 28, 1982
    Assignee: Bolton - Emerson, Inc.
    Inventor: Donald W. Danforth
  • Patent number: 3946951
    Abstract: A vortical circulation type pulper has a bladed rotor and stator with a fixed clearance and operates at conventional horsepower to defibre conventional pulp, capable of being defibered, until the fibres are separated. With unconventional pulp, hemp, flax, rags, leather, and certain rejects, which cannot be so defibered, the rotor of the pulper of this invention is advanced to zero clearance and the horsepower increased about fifty percent, the resultant thrust grinding the mass of pulp, and then fibrillating the fibres in the pulper to a desired degree of refining. The rotor then backs off and the refined pulp is dumped from the pulper. An automatic freeness tester senses the condition of the pulp and actuates the electric control circuit.
    Type: Grant
    Filed: June 21, 1974
    Date of Patent: March 30, 1976
    Assignee: Bolton-Emerson, Inc.
    Inventor: Donald W. Danforth