Patents by Inventor A-Chien Yeh

A-Chien Yeh 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: 5193109
    Abstract: A zoned microcell system with sector scanning for cellular telephone systems has a plurality of contiguous cells, each having a different assigned set of transmission frequency channels, arranged with handoff means for maintaining continuous communication with mobile telephones moving from cell to cell. The system includes at least one cell having a plurality of transmitting and receiving antenna sets. Each set is positioned at a respective antenna sub-site within the periphery of the cell at a suitable location, and is configured so that propagation and reception of signals is limited to a transmission zone which is substantially within the boundaries of the cell and which is substantially less in area than the cell. Control means monitor the strength of the signal received by each of the antenna sets at each frequency channel in the assigned set.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: March 9, 1993
    Assignee: PacTel Corporation
    Inventor: William Chien-Yeh Lee
  • Patent number: 5137601
    Abstract: A papermaking fabric for use in a papermaking machine having a base fabric formed of synthetic filament machine direction and cross-machine direction yarns. A fiber batt formed of synthetic fibers secured to at least a support surface of the base fabric. Both the fibers and the filaments are formed of polypropylene terephthalate so that a papermaking press fabric having chemical resistance characteristics of polyester fabrics and physical properties of nylon fabrics is produced.
    Type: Grant
    Filed: June 26, 1991
    Date of Patent: August 11, 1992
    Assignee: Wangner Systems Corporation
    Inventor: Chien-Yeh Hsu
  • Patent number: 4878278
    Abstract: An apparatus and method for papermaking fabrics (W) with a machine direction fiber batt (24) is disclosed. A carding machine (B, B') is arranged with its carding cylinder (39) parallel to the axis of rotation (22) of carriage rollers (20) about which a base fabric (16) travels in a machine direction. A carded batt (24) with fibers (36) oriented in the machine direction is fed directly in the machine direction onto base fabric (16). An auxiliary needling unit (A) including an auxiliary needling module (44) lightly tacks machine direction batt (24) to base fabric (16) across its width. For this purpose, carding machine (B) and base fabric (16) move relative to one another in a direction transverse to the machine direction. In one embodiment, card (B) moves transversely in synchronization with auxiliary needling unit (A) while carriage (18) carrying the base fabric is stationary.
    Type: Grant
    Filed: April 29, 1988
    Date of Patent: November 7, 1989
    Assignee: Wangner Systems Corporation
    Inventors: Chien-Yeh Hsu, Frank J. McGee, Roger L. Banks
  • Patent number: H1073
    Abstract: A dryer fabric for the dryer section of a paper forming machine consisting of a plurality of coils arranged side by side in parallel rows and connected at opposite ends by hinge pins to form a continuous belt. The coils are formed from a synthetic monofilament consisting of polyphenylene sulphide and fluorocarbon.
    Type: Grant
    Filed: October 18, 1990
    Date of Patent: July 7, 1992
    Assignee: Wangner Systems Corporation
    Inventor: Chien-Yeh Hsu