Patents by Inventor Zdenek Fisher

Zdenek Fisher 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).

  • Hydraulic levelling systems for drilling machines, etc.
    Patent number: 4116409
    Abstract: A drilling machine has a drill carriage pivotally mounted on the upper end of a jib whose lower end is pivoted to a support structure. To maintain the drill carriage in parallelism as the jib pivots, two hydraulically interconnected hydraulic jacks are provided, namely a slave jack pivotally connected between the jib and support structure to form a first triangle with its corners at the pivot point of the jib and the two pivot connections of the jack; and a follower jack pivotally connected between the jib and the drill carriage to form a second triangle with corners at the drill carriage pivot point and the two pivot connections of the follower jack. These two triangles are similar triangles.
    Type: Grant
    Filed: July 1, 1976
    Date of Patent: September 26, 1978
    Assignee: Compair Construction and Mining Limited
    Inventors: Antony Dobson Barber, Zdenek Fisher