Patents Assigned to TVA Holding S.p.A.
  • Patent number: 5143141
    Abstract: Controlled-pressure casting of molten metals using a die with an extractable punch and a fixed die, includes positioning and stopping the punch within the die so as to define a casting cavity with a volume greater that that of the part to be obtained. A metered amount of liquid metal is then poured into the casting cavity through a duct which leads into the cavity, and the punch is moved to close inside the die so as to create a pressure suitable for distributing the metal throughout the cavity. A high-pressure compression is then exerted on the metal contained in the cavity and, maintained until the molten metal solidifies, the punch is partially removed from the die, with separation of the punch from the formed part, before finally removing the punch from the die and extracting the part from the die.
    Type: Grant
    Filed: August 8, 1990
    Date of Patent: September 1, 1992
    Assignee: TVA Holding S.p.A.
    Inventor: Claudio Frulla
  • Patent number: 4838561
    Abstract: The chuck includes a structure supporting a table provided with first sliding seats and with second sliding seats which extend radially from the center of the table and respectively accommodate means for centering the workpiece and means for locking the workpiece; the centering means are controllably movable towards or away from the center of the table, while the locking means are controllably movable from a first position spaced from the workpiece to a second position proximate to the workpiece and are also controllably movable in a direction substantially perpendicular to the face of the table directed towards the workpiece from a release position, in which the locking means are disengaged with the workpiece, to an engagement position, in which the locking means are engaged from the workpiece. The chuck also includes control means which act on the centering means and on the locking means; means are furthermore provided for the connection of the control means to the locking means in the second position.
    Type: Grant
    Filed: May 2, 1988
    Date of Patent: June 13, 1989
    Assignee: TVA Holding S.p.A.
    Inventors: Cesare Baranzelli, Claudio Frulla, Dario Gattolin