Vestil HDC-450 - Manual (Page 5)

5
OPERATION
Warning: Keep all personnel clear of the machine when it is in operation. Be certain no part of any
person or object is under any part of the platform before lowering the unit.
Caution: Always carefully watch cradle and any load on it when it is in operation.
Do not exceed a rate of two feet per second when transporting a load with the drum stacker.
• The standard manually-powered stacker is furnished with a two-speed foot pump. Under empty or
low load conditions, the pump pushes a higher volume of fluid to the cylinder and thus lifts the platform
with fewer foot strokes. With a moderate to full load, the pump will automatically reduce its output in
order to generate the required hydraulic pressure.
• To lift the platform, simply repeatedly press the foot pump's foot treadle. To lower the platform, press
the small lever at the left corner of the pump with your toe. The unt will hold its position when the
lowering lever is released.
VELOCITY FUSE OPERATION
There is a brass velocity fuse with a stainless steel spring in the base of each cylinder. In the
event of a hydraulic hose or fitting failure, the cradle starts to lower at a fast rate. As soon as the de-
scent speed exceeds the fuse's preset speed, the velocity fuse will shut off the oil flow and the cradle
will remain nearly stationary until pressure is reapplied (after repairs are done). This safety feature
reduces the possibility of accidental personal injury or damage to the unit or its loads. If air is intro-
duced into the system, the velocity fuse can lock up even though no failure has occurred. To reset the
velocity fuse just activate pump by depressing the "UP" button. Remove the load and follow the
cylinder air bleed procedures on page 6.