PRONAR T679/3, Operator'S Manual, Page: 41 / 117

SECTION 3 PRONAR T679/3 PRONAR T679/4
3.3
3.2 TRAILER CONSTRUCTION
3.2.1 CHASSIS
Trailer chassis consists of subassemblies indicated in figure (3.1). Lower frame (1) is a
structure welded from steel sections. The main support elements of the frame are two
longitudinal members connected with crossbars. In the middle section there are sockets (5)
used for mounting the tipping hydraulic cylinder. Load box support (10) is mounted in front of
the sockets of the tipping cylinder. At the rear of the frame there is a rear beam serving as
swivel point during the tipping of the load box to the rear. Under the beam there is a rear
hitch socket to which the hitch (12) is attached, and hydraulic and pneumatic system sockets
for connecting the second trailer. On both sides, at the rear of the frame, lights support
beams (7) are bolted.
The trailer tandem suspension consists of two trailing arms (9). Two half axles are welded to
each trailing arm (8). This suspension is the bogie suspension system. The trailing arms are
attached to the frame by means of pins mounted in the slide bearings of lower frame (1) and
trailing arms (9). The half axles are made from square bar ended with a pin on which the hub
is mounted with the use of cone bearings. The wheels are single and equipped with shoe
brakes activated by mechanical cam expanders.
In the front part of the chassis, there is mechanical parking stand (3), which supports the
trailer disconnected from the tractor. Next to the support, conduit bracket (13) is bolted to
lower frame (1). The bracket is used for storing and securing the plugs and sockets of the
trailer system conduits.
Parking brake crank mechanism (1) is located on the left side of the lower frame. Drawbar (2)
is bolted to the faceplate of the lower frame. Location of the drawbar can be adjusted
depending on the tractor hitch (upper or lower) used to hitch the trailer. Rotating drawbar eye
(10) with the eye of
∅
50 mm is attached to the drawbar faceplate in the lower position.
Optionally, fixed drawbar eye with the eye diameter of
∅
40 mm is mounted to the trailer with
the drawbar in the upper transport position.