Haessler Inc., Guelph, Ontario, Canada, has rolled out the pre-production prototype of a new battery-powered aerial lift that offers a 19’7” platform height, compactness, quiet operation, and no chance of hydraulic fluid leakage.
Haessler introduced the new WolfLifT at an open house in its facility early in October.
Haessler Inc. president Wolf Haessler, who founded Skyjack, says the new lift is ideal for facilities like banks, office buildings, stores, schools, hospitals, clean rooms, food-processing plants, and other places that want clean, quiet operation from a compact machine.
The team that Haessler assembled to design and build the WolfLifT combines bright young engineers with experienced veterans, including Dieter Bauer, who says he helped Wolf Haessler hand-build the first Skyjack lift a few decades ago.
The WolfLifT has a unique look. Although its four-section telescoping central tower resembles a mast lift, the tower’s cross section is a large 32” x 30”.
It is also unique in that each section telescopes on four racks and pinions located at its corners. Both Haessler and manufacturing engineering manager Jonathan Vallier point out that the telescoping tower sections do not touch each other or rely on contact for stability, as do many telescoping masts. The WolfLifT's tower strength and stability come from the racks and pinions.
Haessler says that another of the machine’s keys to stability is having the platform recessed inside the side supports of the top moving section of tower, rather than perched atop it.
The machine’s stability also comes from mounting the tower's base low on the chassis. Vallier says that in side-pull tipping tests, a WolfLifT prototype proved far more stable than the standard-style 19-ft. scissor lift tested next to it.
The WolfLifT’s maximum platform height is 19’7”, its stowed height is 78 in., and the step-in height is 18 in.
The compact chassis measures just 30 in. wide x 60 in. long to fit through standard single doorways and into elevators. Its 2,840-lb. weight is distributed evenly from front to back.
The platform measures 22 in. x 60 in. and can hold 500 lbs., but the capacity may rise to 550 lbs. by the time all testing is complete and production starts. The platform is rated to hold two people.
A 30-in. rollout extension deck expands the platform size to 22” x 90” and the extension has a capacity 250 lbs. The extension deck is pushed out manually and travels smoothly on plastic rollers. A chain-and-sprocket system keeps the deck square to the platform so it extends and retracts smoothly without binding.
The tower has four stages: the base, 1st moving, 2nd moving, and 3rd or “platform” stage. The stages elevate and are supported by rack-and-pinion systems at each corner. The stages do not touch each other or rely on stage-to-stage contact for strength. The racks and pinions transfer vertical loadings and an internal frame at the bottom of each tower section (shown in one of the accompanying photos) keeps the tower square, and supports each section’s drive motor, pinions, and gearing. The tower can rise to full height in 23 seconds.
The electrical system is 24V DC, powered by four 6V wet batteries. The system powers two travel-drive motors and the three motors that raise the tower sections.
All five motors are identical and rated at 2.5-hp in intermittent operation. The steering motor is 500W. In a recent test, a prototype WolfLifT completed 137 Hird cycles on a full charge. Recharging takes about 8 hours.
The CANBus control system uses a single joystick controller and five nodes to run all functions. The system needs only a four-conductor control cable between nodes, so wiring is minimal. The single joystick operates travel, steering, platform raising, and platform lowering.
The emergency lowering control on the chassis is powered by a separate, automatically charged battery so that it will work even if the main system batteries are discharged.
The umbilically attached control box can be used in the platform or for traveling the machine remotely if desired.
Travel and steering are done by the front wheels. The machine can travel at 3 mph stowed or 0.7 mph at full height. Pothole protection support bars deploy automatically by platform motion and are self-locking.
The WolfLifT will climb a 25% grade. The minimum inside turning radius is 0 in. The wheelbase is 48 in. and ground clearance is 3 in.
Tie-down spots for securing the machine are provided at all four corners, and fork pockets run lengthwise from the rear of the chassis to the front.
According to Jonathan Vallier, the only maintenance required is expected to be the normal care needed for wet batteries and visual inspection of the electrical and mechanical components, though actual requirements will be confirmed by longer-term testing.
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