Patents by Inventor Josef F. Drs

Josef F. Drs 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).

  • Workable cementitious compositions
    Patent number: 5609681
    Abstract: A process for modifying the slump of a concrete or mortar by the addition at different times of a water-soluble poly(alkylene oxide) and a .beta.-naphthalene sulphonate-formaldehyde condensate, a plasticizer or superplasticizer which is selected from lignosulphonates, melamine sulphonate formaldehyde condensates, carboxylates and selected styrene-maleic anhydride copolymers. The poly(alkylene oxide) is preferably partially replaced by a (hydroxy)alkyl cellulose. The process is advantageously used in shotcreting.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: March 11, 1997
    Assignee: Sandoz Ltd.
    Inventors: Josef F. Drs, Tom Melbye, Odd M. Tjugum, Salvatore Valenti
  • Workable cementitious compositions
    Patent number: 5494516
    Abstract: A process for modifying the slump of a concrete or mortar by the addition at different times of a water-soluble poly(alkylene oxide) and a .beta.-naphthalene sulphonate-formaldehyde condensate, a plasticizer or superplasticizer which is selected from lignosulphonates, melamine sulphonate formaldehyde condensates, carboxylates and selected styrene-maleic anhydride copolymers. The poly(alkylene oxide) is preferably partially replaced by a (hydroxy)alkyl cellulose. The process is advantageously used in shotcreting.
    Type: Grant
    Filed: July 20, 1993
    Date of Patent: February 27, 1996
    Assignee: Sandoz Ltd.
    Inventors: Josef F. Drs, Tom Melbye, Odd M. Tjugum, Salvatore Valenti
  • Shotcrete compositions
    Patent number: 5413819
    Abstract: The storage and processing times of sprayed concrete can be significantly extended by the addition of a retarder, a chemical compound which is capable of chelating with calcium ions. Preferred retarders are phosphonic acid derivatives which have at least one amino and/or hydroxyl group. The retarder can be used for both wet- and dry-sprayed concrete, the usual accelerators can be used for activation, and the strength is not adversely affected.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: May 9, 1995
    Assignee: Sandoz Ltd.
    Inventor: Josef F. Drs
  • Concrete spraying process
    Patent number: 5356671
    Abstract: A process for improving the rebound properties of sprayed concrete comprises the inclusion therein of micro-silica which has been pretreated with from 2 to 25% by weight thereof of a liquid selected from water, an alkanolamine, a polyol and an aqueous solution of at least one concrete additive, an alkanolamine, a polyol and a water-soluble cellulosic compound. The process is especially effective when used in conjunction with the dry spraying process.
    Type: Grant
    Filed: March 17, 1993
    Date of Patent: October 18, 1994
    Assignee: Sandoz Ltd.
    Inventor: Josef F. Drs