Patents Assigned to Hofmann GmbH
  • Patent number: 4277976
    Abstract: A process and apparatus for measurement of nonuniformity of mass of a gyro rotor having a single bearing. The gyro rotor, which is mounted in a radially fixed and spherically yielding pivot, is rotated to a predetermined speed. The static imbalance of the rotating rotor is then determined by measuring the magnitude and angular position of excursion of the rotating rotor. A force couple acting on the gyro rotor and drift of mass of the gyro rotor are determined by sensing movement of a surface of the rotating rotor at two different times. Preferably, the determination of static imbalance, force couple, and drift are obtained in a single course of measurement. After the preceding have been measured, the components of a mass balancing operation for correcting the measured nonuniformities are determined.
    Type: Grant
    Filed: July 6, 1979
    Date of Patent: July 14, 1981
    Assignee: Gebr. Hofmann GmbH & Co. KG
    Inventors: Richard Mueller, Guenther Himmler
  • Patent number: 4168627
    Abstract: Apparatus for mounting and centering a wheel on a mounting spindle of a testing machine, including a shaft portion, a centering taper member on the shaft portion for engaging a center hole in a wheel to be mounted, a fixing nut which can be screwed on the shaft portion for pressing the wheel against the centering taper member for centering the wheel, a spring operable to urge the taper member towards the nut, a housing member on the shaft portion around a part of the spring, a covering means covering the spring for protection thereof, the covering means being disposed on the shaft portion and at least partly in the housing member, and means for limiting the movement of the spring towards a fully relaxed condition thereof thereby to maintain a pre-stressing in the spring.
    Type: Grant
    Filed: December 22, 1977
    Date of Patent: September 25, 1979
    Assignee: Gebr. Hofmann GmbH & Co. KG Maschinenfabrik
    Inventors: Ludwig Held, Eickhart Goebel
  • Patent number: 4124191
    Abstract: A two-pillar, above floor elevating platform for vehicles having lift trucks disposed in each of the two pillars respectively. A three-phase AC motor in each pillar drives each lift truck vertically along the pillar. Apparatus which synchronizes the movement of the two lift trucks is located in a base platform upon which the two pillars are mounted. One of the motors may be disconnected when the torque necessary to lift the vehicle can be developed by the other motor. A one-phase to three-phase converter may be used to power the vehicle elevating platform in areas where only one-phase power is available.
    Type: Grant
    Filed: December 27, 1977
    Date of Patent: November 7, 1978
    Assignee: Gebr. Hofmann GmbH & Co., Maschinenfabrik
    Inventor: Dionys Hofmann
  • Patent number: 4105097
    Abstract: A locking device for a lift having an arm pivotably mounted for horizontal movement about a lifting carriage with two tubular members each pivotably connected at one end to the arm. One of the tubular members extends into a cylindrical housing and is locked thereto by balls mounted in ball cages urged by a spring to a locking position. The other tubular member is locked to the first tubular member by similar balls, cages and spring. A sleeve longitudinally slidably exterior to the two tubular members includes pins for engaging the ball cages to release the two tubular members.
    Type: Grant
    Filed: May 2, 1977
    Date of Patent: August 8, 1978
    Assignee: Gebr. Hofmann GmbH & Co. KG, Maschinenfabrik
    Inventor: Horst Hegenbart