Patents by Inventor Harmen Reinaldus Vogelzang

Harmen Reinaldus Vogelzang 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: 5967702
    Abstract: A pit prop has two opposed ends and comprises two bearing plates located at the ends, two telescopically displaceable prop elements, a number of separate resiliently compressible rubber discs arranged adjacent each other and a tubular indicating element. The prop includes a further bearing plate with the discs being located between two bearing plates to permit yielding of the pit prop under a load. The indicating element has markings thereon to indicate the load condition of the prop. The prop includes a locking device for releasably locking the prop elements with respect to each other.
    Type: Grant
    Filed: April 28, 1998
    Date of Patent: October 19, 1999
    Inventor: Harmen Reinaldus Vogelzang