Patents by Inventor Sjirk W. Zijlstra

Sjirk W. Zijlstra 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).

  • Cane bolt with spring and slotted stop
    Patent number: 8250811
    Abstract: A cane bolt is spring biased up to allow a movable barrier with which the cane bolt is engaged to move. The cane bolt can be pushed down into a strike hole to prevent movement of the barrier. To hold the cane bolt down, a pin on the cane bolt abuts a slotted stop on the barrier. To raise the cane bolt, the cane bolt is simply rotated so that the pin aligns with and thus passes through the slot, allowing the spring to urge the cane bolt up.
    Type: Grant
    Filed: January 27, 2010
    Date of Patent: August 28, 2012
    Inventor: Sjirk W. Zijlstra
  • CANE BOLT WITH SPRING AND SLOTTED STOP
    Publication number: 20110179720
    Abstract: A cane bolt is spring biased up to allow a movable barrier with which the cane bolt is engaged to move. The cane bolt can be pushed down into a strike hole to prevent movement of the barrier. To hold the cane bolt down, a pin on the cane bolt abuts a slotted stop on the barrier. To raise the cane bolt, the cane bolt is simply rotated so that the pin aligns with and thus passes through the slot, allowing the spring to urge the cane bolt up.
    Type: Application
    Filed: January 27, 2010
    Publication date: July 28, 2011
    Inventor: SJIRK W. ZIJLSTRA