DEFINITION AND FUNCTION
The Model VBR-400 DOK-LOK vehicle restraint is an
electromechanical, self-aligning restraint device used to
secure trucks and semi-trailers (with an intact Rear
Impact Guard [R.I.G.]) to the face of a loading dock.
This is achieved by securing the R.I.G. with a DC
powered linear actuator operated steel barrier. This pre-
vents forward movement of the trailer that may create
an unsafe void between the face of the dock and the
rear end of the trailer during forklift operations, or to
create an obstruction noticeable to the truck driver,
should the driver accidentally attempt to leave the dock
while the trailer is still being serviced.
The proper or improper activation of the barrier is
monitored by:
VISUAL CONTROL – one set of flashing green and red
lights located inside of the building for the fork truck
operator, and one set of lights located outside of the
building for the truck driver.
AUDIO CONTROL – an intense horn will sound at the
inside of the building warning the fork truck operator if
there is no R.I.G. or if unsecured condition exists. In
either case, the trailer must be secured by other means
(wheel chocks, etc.) prior to servicing the trailer.
FEATURES
See Figure 2 for locations of these features:
R.I.G.
R.I.G. is an acronym used for a “Rear Impact Guard” that
is Federally mandated to be located on the rear of over the
road trailers to prevent accidental underride by automobiles.
ROLLER TRACK ASSEMBLY
This assembly is mounted to the loading dock wall to
guide the CARRIAGE ASSEMBLY in a vertical plane
and provide the top mount for the CARRIAGE RETURN
SPRINGS. Incorporated features in this assembly are
SPRING GUARDS, SPRING COVER STOPS and a
CARRIAGE ASSEMBLY TOP STOP. It also transmits
the creep force or pull out force exerted on the
BARRIER from a trailer to the loading dock wall.
CARRIAGE ROLLER ASSEMBLY
This roller is comprised of an outer housing with a needle
bearing that is pre-lubricated to allow easy movement of
the CARRIAGE ASSEMBLY and retain the CARRIAGE
ASSEMBLY within the ROLLER TRACK ASSEMBLY.
CARRIAGE RETURN SPRINGS
These springs bias the CARRIAGE ASSEMBLY to its
stored full up position within the ROLLER TRACK
ASSEMBLY or to maintain contact with the R.I.G.
(Rear Impact Guard) of a trailer.
LOWER SPRING BAR
This bar provides the bottom mount for the CARRIAGE
RETURN SPRINGS and the CARRIAGE ASSEMBLY
TOP STOP.
CARRIAGE ASSEMBLY
The CARRIAGE ASSEMBLY, with its triangular housing
and sloped front, is constructed of abrasion resistant
materials designed to be contacted by the R.I.G. of a
trailer. This allows the CARRIAGE ASSEMBLY to be
self-positioning to restrain the trailer once the BARRIER
has been activated by the dock attendant.
CARRIAGE ASSEMBLY SLOPE EXTENSION
This allows trailers with low ground clearance R.I.G.s to
be serviced by the DOK-LOK and is constructed of high
grade steel tubing to resist abrasion.
R.I.G. SENSOR
The R.I.G. SENSOR resides within the CARRIAGE
ASSEMBLY and is also spring biased to maintain an
upward attitude. This device, in conjunction with
SENSING SWITCHES and a fully raised BARRIER,
senses the presence of the trailer R.I.G.
BARRIER
The BARRIER is housed within the CARRIAGE
ASSEMBLY and provides an obstruction in front of the
trailer R.I.G. to prevent it from rolling/creeping away from
the dock. The BARRIER is constructed from a high
grade steel to provide a long service life. The BARRIER
is put into position by a LINEAR ACTUATOR
ASSEMBLY. The return of the BARRIER is through
gravity and assisted by the BARRIER RETURN
SPRING. The BARRIER has an attached bracket that
compresses its return spring and provides the mount for
the switch sensing magnet.
LINEAR ACTUATOR ASSEMBLY
This provides the means of moving the BARRIER to its
active position at the same time it is compressing the
BARRIER RETURN SPRING.
SPRING COVERS AND INTEGRAL LIP GUIDE
There are two independent SPRING COVERS, the right
hand SPRING COVER having an INTEGRAL LIP GUIDE
which is used to guide the lip past the ROLLER TRACK
ASSEMBLY in a below dock end load condition. These
SPRING COVERS protect the springs and keep debris
out of the ROLLER TRACK ASSEMBLY when the VBR-400
DOK-LOK vehicle restraint is in its stored full up position.
SENSING SWITCHES, CONTROL
HARNESS, CONTROL BOX, OUTSIDE
LIGHT BOX, AND SIGNAGE
The combination of these components is used to
interface the VBR-400 DOK-LOK vehicle restraint to the
dock attendant, providing a means of control to operate
the VBR-400 DOK-LOK vehicle restraint visual and
audio communications, as well as providing a visual
communication to the trailer driver.
5
RITE-HITE VBR-400 DOK-LOK
Owner’s Manual
