Patents Assigned to Waterbury Pen Corporation
  • Indicating chart pen cartridge with transparent wall
    Patent number: 5033896
    Abstract: A cartridge consisting of a hollow casing of molded plastic substance and an ink-retention sponge disposed in the casing, together with a stylus carried by the casing, for producing ink lines on a chart, from the ink content of the casing and contained retention sponge. A wall of the casing is transparent to enable the retention sponge therein and the ink carried thereby to be viewed by a user from the exterior of the casing. The intensity of the observed ink color is an indication as to the amount of ink remaining in the casing and sponge.
    Type: Grant
    Filed: November 6, 1987
    Date of Patent: July 23, 1991
    Assignee: Waterbury Pen Corporation
    Inventors: William F. Lytle, Michael Mathews