Service manual
7
DESIGN AND CONSTRUCTION
The standard mobile lift is suitable to lift wheeled vehicles by the tires. It normally comes in pairs of
columns totaling 2, 4, 6 or 8 column systems. Each column consists of a rigid frame of three-wheel design
for maneuverability, lifting carriages with tire forks, control panel, electric-hydraulic power unit, and
hydraulic cylinder.
Two of the wheels are spring loaded and in fixed positions on the column base. The third wheel is steerable
and hydraulically operated, permitting movement of the unloaded columns, but allowing the column to sit
firmly on the floor before a load is applied.
Since this lift is battery powered, each post is identical except for post identification (Post ID), and each has
communication outlets to attach to the other posts, forming configurations from 2 posts all the way up to 8
posts (see lift setup).
When the lift is raised or lowered in the “synchronized” mode the actual movement of each carriage is
measured and compared by each post’s PLC (programmed logic controller). If the movement of any carriage
exceeds that of any other carriage in the system, the carriage is slowed down or stopped until the others catch
up.
The each post houses the same controls, enabling the user to control the whole lift, a single post or a post-
pair combo at any post desired.
A hydraulic cylinder, powered by an electric-hydraulic pump unit, controls the carriage movement. There is
an internal relief valve on the pump unit, which prevents overloading of the carriage.
A separate automatically engaging back-up mechanical safety lock latch prevents lowering of the carriage in
the event of failure of the hydraulic system.
All movement controls are of the “vigilance control” type which are operable only as long as the operator is
depressing the button. As soon as the button is released the motion will stop.
All columns have controls for synchronized or individual column movement, plus an “Emergency Stop”.
Depressing the Emergency Stop button will stop all columns immediately and will not permit any column
movement until the depressed button is reset.