Ladder apparatus and method for large mobile equipment
AssigneeMarrowbone Development Company
InventorGeorge W. Graham
Life of this patent
Estimating the term…
Abstract
A ladder apparatus and method for use with large construction equipment, such as large tractors, mining trucks and similar vehicles that have an operator's platform or operating station located a substantial distance off the ground. The powered ladder has a fixed ladder portion rigidly attached to such a vehicle. The fixed ladder portion has spacedly attached thereto a frame element upon which a retractable ladder element is slidably disposed. The retractable ladder element is raised and lowered by an electric winch operable from the vehicle's operating station.
Claims16
Apparatus for providing access to an operator station on a large mobile vehicle, comprising:
- a ladder fixedly mounted on such a vehicle, said ladder having substantially parallel side stringers and transverse treads,
- a frame element fixedly attached to said fixedly mounted ladder and spaced therefrom, said frame element having parallel stringers that are aligned with and spaced from the stringers of said ladder,
- a retractable ladder slidably disposed on the stringers of said frame element,
- means for raising and lowering said retractable ladder, and
- means for controlling said means for raising and lowering.
Apparatus for providing access to an operation station on a mobile vehicle, comprising:
- a ladder fixedly mounted on such a vehicle, said ladder having substantially parallel side stringers and transverse treads,
- a frame element fixedly attached to such a vehicle adjacent said frame element's top and bottom, said frame element being spaced from said fixedly mounted ladder, and having parallel stringers aligned with the stringers of said ladder,
- a sleeve member slidably disposed on the stringers of said frame element,
- a retractable ladder fixedly attached to said sleeve member, said retractable ladder being disposed to extend said fixed ladder to a position adjacent the earth, and
- means for raising and lowering said retractable ladder.
Dependencies are inferred from the claim text.