Patents Assigned to David K. Shenk
  • Patent number: 5358219
    Abstract: A crane claw tilt switch in addition to a cable tension switch is used to prevent a crane claw from becoming entangled in its suspending cable. When the claw lands on the floor or some other object, it either comes to rest or starts to tilt. If it comes to rest, further lowering creates cable slack, operating the tension switch. If it starts to tilt, the tilt switch operates before the claw tilts enough to allow an arm of the claw to catch on the cable. In response to the operation of either switch, a system processor commands the claw to automatically raise, ensuring that it does not become entangled in its cable.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: October 25, 1994
    Assignee: David K. Shenk
    Inventors: David K. Shenk, Anthony R. Fabrello