Patents by Inventor John R. Field

John R. Field 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: 4820424
    Abstract: An aqueous organic or inorganic suspension can be coagulated and then flocculated by flowing it past a shaped body comprising a mixture of water soluble multivalent metal coagulant and a water soluble organic polymeric flocculant in the form of substantially discrete particles. The surface of the shaped body is eroded by the flowing stream to form a solution of the coagulant in which the polymeric flocculant particles are entrained, and these subsequently dissolve into the suspension.
    Type: Grant
    Filed: July 27, 1987
    Date of Patent: April 11, 1989
    Assignee: Allied Colloids Ltd.
    Inventors: John R. Field, Nicholas D. Smith
  • Patent number: 4820645
    Abstract: Measurement of the ionic value X of a solution of a polyelectrolyte after shearing, for instance by a rotating blade, and/or measurement of the ionic value Y of a solution of polyelectrolyte before shearing, and especially the difference between t he values X and Y, gives a useful indication of the degree of cross linking of the polyelectrolyte and so can be utilized to control the manufacture of the polyelectrolyte, for instance drying conditions, or the storage or use of the polyelectrolyte, for instance its suitability or dosage in a flocculation process.
    Type: Grant
    Filed: April 23, 1986
    Date of Patent: April 11, 1989
    Assignee: Allied Colloids, Ltd.
    Inventors: John R. Field, David Farrar, Peter Flesher
  • Patent number: 4789485
    Abstract: The clarification of a sodium aluminate liquor in the Bayer Process, especially the liquor obtained by Kelly filter filtration of the supernatant from the primary settling stage, is improved by flocculation with a polymer of the formula CH.sub.2 .dbd.C(R.sup.1)CONHR.sup.2 NR.sup.3 R.sup.4 wherein R.sup.1 is hydrogen or methyl, R.sup.2 is straight or branched chain C.sub.2-8 alkylene having at least 2 carbon atoms in the backbone and R.sup.3 and R.sup.4 are independently selected from C.sub.1-4 alkyl.
    Type: Grant
    Filed: March 25, 1987
    Date of Patent: December 6, 1988
    Assignee: Allied Colloids Ltd.
    Inventors: John R. Field, Gillian M. Moody, Trevor K. Hunter
  • Patent number: 4759856
    Abstract: A cross linked high molecular weight polymer formed from a water soluble monomer or blend of monomers and which has IV and/or solubility and/or rheology properties indicating that it would be unsuitable for use as a flocculant can be used as a flocculant after shearing the polymeric material. The shearing may be applied to the polymeric material before addition to the suspension that is to be flocculated or can be applied to the suspensionthat is being flocculated. The shearing increases the intrinsic viscosity of the polymeric material and can improve its rheology and solubility. The polymeric material must be of high molecular weight.
    Type: Grant
    Filed: April 23, 1986
    Date of Patent: July 26, 1988
    Assignee: Allied Colloids, Ltd.
    Inventors: David Farrar, John R. Field, Peter Flesher, Tony Whittaker
  • Patent number: 4720346
    Abstract: When flocculating an aqueous suspension of suspended solids using a high molecular weight synthetic polymeric flocculant, the shear stability of the flocs is increased if the polymeric material includes polymeric particles of below 10 .mu.m dry size. The flocculated solids can therefore be subjected to shear without increasing the amount of discrete suspended solids in the aqueous medium and generally they are subjected to shear by shearing the aqueous medium containing them, either before dewatering, generally on a centrifuge, piston press or belt press, or by continuously agitating them, for instance in a chemical reaction medium. The polymeric material is generally formed by mixing into water polymeric particles made by reverse phase or emulsion polymerization in the presence of added cross linking agent. Alternatively, particles insolubilized by insoluble monomer may be used. A reverse phase dispersion of water soluble polymer may be used if the particles remain undissolved, e.g.
    Type: Grant
    Filed: April 23, 1986
    Date of Patent: January 19, 1988
    Assignee: Allied Colloids Ltd.
    Inventors: Peter Flesher, David Farrar, John R. Field
  • Patent number: 4709615
    Abstract: An electrical firing arrangement for the sequential firing of a plurality of mortars stacked in end-to-end relationship within a single launching barrel. The firing arrangement comprises a pulse generator for producing mortar firing pulses and a circuit for applying these pulses to an electro-magnetic stepping switch which applies the pulses in turn over pairs of wires to igniters of the respective mortars as the stepping switch is stepped from one position to the next. The stepping switch comprises normally-open contacts which close when an operating coil is effectively energized by a firing pulse and switch wipers move out of engagement with one pair of associated contacts on the stepping switch towards the next pair of associated contacts on the same switch.
    Type: Grant
    Filed: May 8, 1985
    Date of Patent: December 1, 1987
    Assignee: Plessey Overseas Limited
    Inventor: John R. Field
  • Patent number: 4585812
    Abstract: A high solids, pumpable stable dispersion of substantially anhydrous water soluble or swellable polymer particles contains at least 70% by weight polymer and contains 1 part by weight fine polymer particles below 10 microns in size and 0.1 to 7 parts by weight coarse polymer particles having a size of 10 to 300 microns with substantially no particles above 300 microns.
    Type: Grant
    Filed: February 11, 1985
    Date of Patent: April 29, 1986
    Assignee: Allied Colloids Limited
    Inventor: John R. Field
  • Patent number: 4515884
    Abstract: Toner images are fused to a substrate, such as paper, with a heated fusing member having a silicone elastomer fusing surface by coating the elastomer fusing surface with a toner release agent which includes an unblended polydimethyl siloxane having a kinematic viscosity of from about 7,000 centistokes to about 20,000 centistokes. In a preferred embodiment the polydimethyl siloxane oil has a kinematic viscosity of from about 10,000 to about 16,000 centistokes and the fuser member is a fuser roll having a thin layer of a crosslinked product of a mixture of .alpha..omega.-dihydroxypolydimethyl siloxane, finely divided tabular alumina and finely divided iron oxide.
    Type: Grant
    Filed: September 21, 1982
    Date of Patent: May 7, 1985
    Assignee: Xerox Corporation
    Inventors: John R. Field, Haribhajan S. Kocher, Arthur C. Martellock
  • Patent number: 4263529
    Abstract: An evacuated envelope is divided into a plurality of electron propagation channels. Each channel includes an electron gun section and a beam guide section. The electron gun section provides electrons in the form of beams to the guide section. The guide section includes spaced guide meshes and the electrons are propagated along the channel in the space between the guide meshes. A launch section, in the form of at least one pair of launch electrodes, is arranged between the electron gun section and the beam guide section. The conditions under which electrons leave the gun section and enter the guide section are selected by the application of selected voltages to the launch electrodes.
    Type: Grant
    Filed: October 22, 1979
    Date of Patent: April 21, 1981
    Assignee: RCA Corp.
    Inventors: Wieslaw W. Siekanowicz, John R. Fields