Patents by Inventor John L. Leng

John L. Leng 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: 5281336
    Abstract: A metal extractant for extracting metals from aqueous solutions of metal salts comprising at least one o-hydroxyaryloxime and one or more aliphatic or aromatic-alicyclic alcohols.
    Type: Grant
    Filed: October 6, 1992
    Date of Patent: January 25, 1994
    Assignee: Imperial Chemical Industries PLC
    Inventors: Raymond F. Dalton, John L. Leng
  • Patent number: 5230364
    Abstract: A proportional pressure release valve comprising a valve body incorporating a valve seat, a valve closure member mounted in the valve body and cooperable with the valve seat to control flow of fluid through the valve from an inlet pressure port to an outlet tank port, and electromagnetic control means having a push pin operable to move, via resilient means, the valve closure member in dependence upon the magnitude of a control current applied thereto, wherein the valve further comprises damper means provided between the push pin and the valve closure member. The valve may also comprise an anti-cavitation ring having a bore and disposed downstream of the valve seat, the anti-cavitation ring being apertured to provide a fluid connection between the ring core and the tank port. The valve closure member may be guided for movement towards and away from the valve seat by guide means comprising at least one linear bearing.
    Type: Grant
    Filed: February 11, 1992
    Date of Patent: July 27, 1993
    Assignees: Vickers, Incorporated, Tokimec Inc.
    Inventors: John L. Leng, Tsuyoshi Ando, Kousuke Hatakenaka, Akio Mito
  • Patent number: 5176843
    Abstract: A composition for use in extracting copper values from aqueous solutions of metal salts which comprises:A. one or more o-hydroxyaryloximes containing at least 5 aliphatic or alicyclic carbon atoms which are strong metal extractants which, in 0.2 molar solution in an aliphatic hydrocarbon solution when loaded with 50% of the theoretical uptake of copper, will be in equilibrium with a 0.1 molar solution of copper as copper perchlorate at a pH less than 1;B. one or more branched chain aliphatic or aromatic-aliphatic alcohol containing 14 to 30 carbon atoms or aliphatic or aliphatic-aromatic esters containing 10 to 30 carbon atoms in which the ratio of the number of methyl carbon atoms to the number of non-methyl carbon atoms is higher than 1:5 and which is selected from the group consisting of highly branched hexadecyl alcohol, highly branched isooctadecyl alcohol and a diester of 2,2,4-trimethyl -1,3-pentanediol; andC. one or more o-hydroxyarylketoximes which are weak metal extractants and which, in 0.
    Type: Grant
    Filed: June 4, 1990
    Date of Patent: January 5, 1993
    Assignee: Imperial Chemical Industries PLC
    Inventors: Raymond F. Dalton, John L. Leng
  • Patent number: 4978788
    Abstract: A composition for use in extracting copper values from aqeous solutions of metal salts which comprises one more o-hydroxyaryloximes containing at least 5 aliphatic or alicyclic carbon atoms which are strong metal extractants which, in 0.2 molar solution in an aliphatic hydrocarbon solution loaded with 50% of the theoreticl uptake of copper, will be in equilibrium with 0.1 molar solution of copper as copper perchlorate at a pH less than 1; and one or more branched chain aliphatic or aromatic-aliphatic alcohols containing 14 to 30 carbon atoms or aliphatic or aliphatic-aromatic esters containing 10 to 30 carbon atoms, wherein the ratio of the number of methyl carbon atoms to the number of non-methyl carbon atoms is higher than 1:5, and which is selected from the group consisting of highly branched isohexadecyl alcohol, highly branched isooctadecyl alcohol and a diester of 2,2,4-trimethyl-1,3-pentanediol; and wherein the weight ratio of A to B is in the range 10:1 to 1:3.
    Type: Grant
    Filed: December 8, 1988
    Date of Patent: December 18, 1990
    Assignee: Imperial Chemical Industries PLC
    Inventors: Raymond F. Dalton, John L. Leng