Patents by Inventor Wenjia Cai

Wenjia Cai 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: 5947018
    Abstract: A mechanical press has a ram carried by a frame and movable to advanced and retracted positions by a ball screw assembly driven by a reversible motor to actuate a cam and follower assembly connected to the ram by a linkage system. The linkage system has a pair of pivot links pivotally connected at one end to a fixed pivot shaft connected to the press frame and connected at their opposite end to a follower nut for movement thereby as the follower nut travels along the length of the driven screw. A pair of roller followers are also driven by the follower nut to move between first and second positions within cam tracks formed in a pair of first lever arms operably connected to the ram. In use, when the motor drives the screw in one direction the first lever arms are rotated in one direction to move the ram to its advanced position wherein the ram urges a die or tool into engagement with a workpiece.
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: September 7, 1999
    Assignee: Unova IP Corp.
    Inventors: Gerrit W. Sloat, Gerald A. Brown, Donald D. Pagels, Wenjia Cai, William M. Faitel