Patents by Inventor Mark Thomas Davidson

Mark Thomas Davidson 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).

  • Elevator car door locking and unlocking mechanism
    Patent number: 6508332
    Abstract: An elevator car door opening and closing apparatus is taught having a clutch assembly carried by each car door for coupling with a landing door locking and unlocking assembly whereby the car and landing doors open and close simultaneously. The clutch assembly includes a four bar mechanical expanding and collapsing parallelogram linkage which engages, unlocks, and opens the landing door. Mechanical linkage is also attached to the parallelogram linkage whereby the elevator car doors may only be forced opened a limited amount if the car is stalled between landing sites.
    Type: Grant
    Filed: July 10, 2001
    Date of Patent: January 21, 2003
    Assignee: Fujitec America, Inc.
    Inventors: Richard Lee Fahl, Mark Thomas Davidson, Mark H. Bayyari, Takeshi Sugimoto
  • Elevator car door opening apparatus
    Publication number: 20020056594
    Abstract: An elevator car door opening and closing apparatus is taught having a clutch assembly carried by each car door for coupling with a landing door locking and unlocking assembly whereby the car and landing doors open and close simultaneously. The clutch assembly includes a mechanical expanding and collapsing parallelogram mechanism which engages, unlocks, and opens the landing door. Mechanical means is also disclosed whereby the elevator car doors may only be forced opened a limited amount if the car is stalled between landing sites.
    Type: Application
    Filed: July 10, 2001
    Publication date: May 16, 2002
    Applicant: Fujitec of America, Inc.
    Inventors: Richard Lee Fahl, Mark Thomas Davidson, Mark H. Bayyari, Takeshi Sugimoto