Patents by Inventor Donald Ritch

Donald Ritch 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: 4073419
    Abstract: A spool of thread, such as dental floss, is housed in a two-part shell or holder, preferably made of plastic. The floor on the bottom one of the shell parts includes a platform to provide a bearing surface for enabling rotation of the spool with a minimum of friction. The top of the upper shell part includes at least one finger which depends far enough to drag, with predetermined friction, against the top of the spool. This friction is sufficient to prevent a random unwinding of the spool and yet small enough to preclude any substantial impedance to the withdrawal of a desired amount of thread from the spool.
    Type: Grant
    Filed: April 19, 1976
    Date of Patent: February 14, 1978
    Assignee: John O. Butler Company
    Inventors: Emanuel B. Tarrson, Steven Tisma, Donald Ritch