Patents by Inventor Friedrich Pfeifer

Friedrich Pfeifer 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: 4441940
    Abstract: In order to improve the temperature constancy of induction boost in a standard working temperature range for fault current safety switches, a Ni-Mo-Cu-Fe alloy is provided whose nickel and copper content in a binary nickel-copper system is defined by a quadrangle of points A (80.5 wt. % Ni and 0 wt. % Cu), B (82 wt. % Ni and 0 wt. % Cu), C (70 wt. % Ni and 16.5 wt. % Cu) and D (70 wt. % Ni and 14.4 wt. % Cu) and whose molybdenum content, z, in wt. % satisfies the relation:11/30 (x-68).ltoreq.z.ltoreq.11/30 (x-63.5)with a given Ni content, x, in wt. % and the remainder of which essentially consists of iron and minor processing impurities. Such an alloy is worked into a 0.05 through 0.3 mm thick tape and wound into a toroidal tape core which is first annealed for about 30 minutes at temperatures between 900.degree. and 1200.degree. C. and is then tempered in accordance with its Mo content at the temperatures between 450.degree. and 550.degree. C. in such a manner that the magnetic anisotropy, K.sub.
    Type: Grant
    Filed: August 10, 1981
    Date of Patent: April 10, 1984
    Assignee: Vacuumschmelze GmbH
    Inventors: Friedrich Pfeifer, Willi Kessler
  • Patent number: 4314594
    Abstract: A technique for processing thin tapes of soft magnetic amorphous metal alloys to reduce their magnetic hysteresis losses. The technique involves preliminarily forming such a tape into a core, heating the core, and then controllably cooling the core, the heating and cooling being conducted in an oxidizing atmosphere. Maintaining the core during processing in a suitable longitudinal or transverse (relative to the tape) magnetic field can also produce improved properties. Certain tape cores so processed have particular magnetic hysteresis loss characteristics never heretofore known.
    Type: Grant
    Filed: April 29, 1980
    Date of Patent: February 9, 1982
    Assignee: Vacuumschmelze GmbH
    Inventors: Friedrich Pfeifer, Wernfried Behnke
  • Patent number: 4290827
    Abstract: An alloy comprised of 45 to 53 wt. % Ni with the remainder iron, and including small amounts of deoxidizing and processing additives is worked into a 0.01 to 0.1 mm thick tape, wound to form a tape core and is then subjected to a final annealing for at least one hour at a temperature of at least 900.degree. C. and thereafter is subjected to a tempering in a magnetic cross-field (i.e., the magnetic lines of force are applied in the plane of the tape perpendicular to the rolling direction thereof). The process provides high impulse permeabilities at induction rises of 1T or larger within the so-processed tape cores. Particularly high impulse permeabilities are achieved in instances where an anisotropic structure with a privileged grain direction <001> in the rolling direction is generated in the tape material via heating and final deformation before winding into a tape core and via a final annealing after winding of the tape core.
    Type: Grant
    Filed: April 4, 1979
    Date of Patent: September 22, 1981
    Assignee: Vacuumschmelze GmbH
    Inventors: Friedrich Pfeifer, Wernfried Behnke
  • Patent number: 4082580
    Abstract: An alloy is described which contains between about 33 and 35% nickel, about 1 and 4% molybdenum and the balance iron with incidental impurities. The alloy is characterized by having a completely secondarily recrystallized structure, improved stability preventing substantial transformation to martensite at temperatures as low as -320.degree. F, high resistance and high initial permeability.
    Type: Grant
    Filed: October 31, 1974
    Date of Patent: April 4, 1978
    Assignee: Vacuumschmelze GmbH
    Inventors: Friedrich Pfeifer, Gunter Klein
  • Patent number: 3991639
    Abstract: Apparatus for protecting tools of hydraulically operated fine punch presses of the type having a main piston as well as quick-closing pistons for imparting movement to the press ram. Keying pistons are arranged at the ram in series with and extending in the same direction as the quick-closing pistons to form a keying gap, variable in response to resistance pressure applied to the ram movement at or near the closing operation. A safety stop switch is arranged for detecting the keying gap and for effecting a stoppage of the machine in the event the keying gap is below a predetermined amount indicating an impediment in the path of the ram.
    Type: Grant
    Filed: April 23, 1975
    Date of Patent: November 16, 1976
    Assignee: SMG Suddeutsche Maschinenbau-Gesellschaft mbH
    Inventor: Friedrich Pfeifer