Design Challenge - September 2016



Jon Pope As a director of Motive Power in Sydney, Australia, Lance Procter specializes in designing complex vehicles. Many have related to mining equipment, and he’s designed towing tractors for heavy aircraft up to A380 size.

Many of the best operators have had years of experience working on-site, often working harder than they should, putting in long hours in sub-optimal conditions. And many of them suffer from the results of that hard-working life. Key among the ailments are knee and hip issues, both of which make it painful and difficult to elevate the feet to the level required to climb ladders or steps, or to clamber up the side of an excavator or loader.

Powered and folding ladders do exist, typically for larger machines, but still require the operator to lift their feet repeatedly for considerable distances to reach the cabin. An alternative, particularly for mid-size excavators, is a cabin that moves vertically on linear actuators, allowing the operator to lower the cab to ground level to enter/exit the machine. There is therefore only one, relatively low step involved.

The power systems remain connected to the cabin via an ‘elephant trunk’ or energy chain, ensuring that the operator has full control whatever the cabin position. Limit switches prevent the excavator slewing until the cab is in the full Up position. Once it reaches that position, latches retain the cabin, and ensure it can be certified to ISO 12117.2 for ROPS.

A further alternative, particularly for mid-size excavators, is a powered vertical lift, requiring only a short step onto a platform. With a folding gate, and perhaps even a drop-down ramp, such a lift can take an operator with limited mobility straight from ground-level to level with the cabin floor. Using a non-rotating single-post telescopic actuator, the lift could be retrofitted to existing machines, and even changed between machines as required. Power would come from an electrically powered hydraulic pump, or from the main hydraulic system if there is provision to stop/start the excavator from ground level.

On mid-size excavators, the platform would still be within the swing circle and would not impact the operation of the machine – although the platform might need to be detached when tramming through a tight entrance.

Of course, getting the operator to the cab is only part of the task. Conversion of the door assembly to sliding rather than hinged reduces the number of steps required to open and enter the cab, and providing a clear floor without trip points, or the necessity for operators to rotate their feet sideways, will help make this whole unit more user-friendly.

The left-hand joystick should also be able to flip rearward to provide a clear path to/from the seat, and grab points to assist when getting out of the seat are also a great idea.

More images from Lance

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