Poweramp VH SERIES HYDRAULIC - Manual (Page 10)

8 4111-0002 — January 2012 8
Component Identification
A — Lip
B — Platform
C — Lip Cylinder(s)* D — Powerpack (Motor/Pump/Reservoir)
E — Logic Block
F — Platform Cylinder(s)* G — Main Frame
H — Lip Keepers (4 used)
I — Maintenance Prop J —Toe Guard (2 used)
K —Raise Button
L —ARTD Switch (option)
The VH dock leveler uses hydraulic logic and one-
button operation for ease of use.
The dock leveler can be operated remotely using the
RAISE button (J) on the control panel .
Platform (B) is raised by pushing and holding the
RAISE button (K). This activates an electric motor (D)
which, in turn, drives a hydraulic pump. The hydraulic
pump forces oil into the platform cylinder(s) (F),
causing the platform to rise. Releasing the RAISE
button allows the platform to lower.
When the platform rises to the point where there is
1 — 3 in. (25.4 — 76.2 mm) of travel left in the
platform cylinder, a cable pulls the valve lever up.
When the cable force exceeds the force necessary
to shift the spool valve inside logic block (E), the
spool shifts, causing oil to be redirected to the lip
cylinder(s) (C). This causes the platform to stop rising
and lip (A) to extend. When the lip has fully extended,
the platform will continue to rise until it reaches the
full raised position.
THEORY
INTRODUCTION
K
L
E
A
B
C
F
G
D
H I