Patents Assigned to R. M. Johnson Company
  • Patent number: 4867607
    Abstract: Linkage apparatus for connecting a use device, preferably a vibrating cable plow, to a ground-engaging vehicle. The linkage apparatus comprises a first arm member having a first mechanism for connecting the first end to the vehicle, a second arm member having a second mechanism for connecting the second end to the use device, a third mechanism for pivotally connecting the first and second arm members, and a mechanism for dampening vibrations between the first and second arm members perferably including resilient members such as air cushion bags.
    Type: Grant
    Filed: June 11, 1987
    Date of Patent: September 19, 1989
    Assignee: R. M. Johnson Company
    Inventors: Robert M. Johnson, Ralph V. Johnson