Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates in general to the transportation of
solid waste material, and in particular to solid waste transportation
vehicles. In transporting refuse from a collection station to a
disposal area it is conventional to use refuse compaction trailers
which are loaded by a stationary packer which hydraulically forces
refuse into the body of the trailer. Collected refuse is usually
brought to centrally located transfer stations which are equipped to
receive the refuse and, through the utilization of stationary packers,
compress the refuse into large trailers to be hauled to refuse burning
plants or landfill area.
Refuse deposited at the transfer station is dumped through
the top opening of a stationary packer and compacted by a packer head
into the body of a trailer. When the trailer is full, it is hauled to
a disposal area. This type of trailer and stationary packer
arrangement has the disadvantage of creating spillage of refuse
outside of the body of the trailer as the tractor is moved away from
the stationary packer. The packer head extends a short distance into
the body to produce packing, however, the elasticity of the packed
refuse forces the refuse rearwardly when the head is withdrawn, thus
creating spillage through the rear opening as the trailer is separated
from the packer.
In addition, in compaction trailers, it is desirable to
reduce the loads acting on the rear wheels and to distribute more of
the loads to the tractor wheels. State regulations usually`limit the
maximum weight carried by each axle, thus to the extent that weight
can be shifted from the rear axles to the tractor axles, the total
load carried by the vehicle can usually be increased.
Broadly, the invention embraces a refuse compaction trailer
comprising a body having surrounding walls, a top, a floor, and an
extension at the rear of the body, having sloped side walls, and an
overhead door enclosing the opening between the sloped side walls. A
stationary packer used in conjunction with the trailer can extend into
the trailer over the extension to the rear of the body between the
sloped walls. Expansion of the compacted refuse when the trailer is
withdrawn from the packer is taken up by the space in the trailer
enclosed by the sloped walls and rear extension. The rear axles of
the trailer are moved back from their normal position, thus moving
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further away from the center of gravity of the load and reducing the
weight supported by the rear axles.
The invention may best be understood by reference to the
following description taken in connection with the accompanying
drawings in which:
Figure 1 is a side view, with portions broken away, of a
conventional refuse compaction trailer coupled to a stationary packer;
~ igure 2 is a side view, with portions broken away, of a
refuse compaction trailer embodying the present invention;
Figure 3 is a side view, with portions broken away, of a
compaction trailer coupled to a stationary packer;
Figure 4 is a rear isometric view of a portion of a refuse
compaction trailer embodying the present invention; and
Figure 5 is a rear isometric view of a portion of a refuse
compaction trailer embodying the present invention with portions
broken away to show the operation of the tailgate mechanism.
Referring to the drawings, Figure 1 shows a conventional
tractor trailer where the trailer is a compaction trailer adapted to
function with a stationary packer to load refuse into the body of the
trailer. The compaction trailer 10 is suitably coupled to a
detachable tractor 11 so the trailer can be hauled over the road to a
disposal site or backed up to a stationary packer 12 for loading. It
can be seen from Figure 1 that the packer 12 abuts the end of the
trailer lO and is suitably coupled to the trailer by hooks or other
means, not shown. Refuse is loaded into the hopper 17 at the top of
the packer and is forced into the trailer by a packing head 18. When
the trailer is moved away from the tractor, the refuse tends to spring
back, out of the rear opening of the trailer spilling on the ground.
The refuse compaction trailer of the present invention as
seen in Figure 2 is adapted to be used with a stationary packer 12 in
the manner shown in Figure 3. The packer includes a charging box 1g
and frame 20 which contains a packer head 18 operated by a double-
acting hydraulic cylinder 21. An hydraulic power unit (not shown) may
be located beneath the packer 12, or at any convenient location. The
charging box of the stationary packer includes a loading hopper 17
into which a material is dumped, for example, from a chute of a
transfer station.
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The refuse compaction trailer in Figure 2 includes anelongate body 23 supported at its rear end on ground engaging rear
wheels 24 and a ~anding gear 25. The body of the trailer 23 includes
a pair of side walls 26 upstanding from a floor 28. A rear portion 29
of the floor 28 projects rearwardly beyond the normal end of the
trailer. The side walls 26 of the body extend rearwardly to the
normal end of the trailer and then form sloped side walls 52 which
enclose the rear portion 29 of the floor of the trailer. The sloped
walls 52 define an opening in the rear of the trailer, through which
the refuse is loaded into the body 23. Refuse is ejected from the
trailer by a hydraulic cylinder 31 and movable ejection plate 32 at
the front of the trailer.
The rear wheels 24 are located under the floor extension 29
to reduce load distribution on the rear wheels. The packer 12 extends
over the rear extension 29, as seen in ~igure 3, to the same relative
position as the packer used with a conventional trailer, as shown in
Figure 1. Thus, the load of refuse packed into the trailer is
essentially the same in both cases and the center of gravity of the
refuse remains in the same location. However, since the rear axles
are located under the extension 29 in the present invention, the
distance between the center of gravity of the refuse and the rear
axles is greater in the present invention than in conventional
trailers. This greater distance between the center of gravity and the
rear axles canse more of the weight of the refuse to be supported by
the tractor wheels and less by the rear wheels of the trailer.
This is particularly desirable where regulations limit the
allowable load per axle on trailers. Normally, these are regulations
which limit both the total load that can be carried by a vehicle and
the load on each axle. The load on the rear axle is usually exceeded
before the total allowable load is met. By reducing the load on the
rear axle, more refuse can be packed into the trailer before the
regulated limits are exceeded.
The rear opening in the body of the trailer de~ined by the
floor rear portion 29, vertical lower door 30, the sloped side walls
52 and the top of the trailer is closed, as seen in Figures 4 and 5,
by the overhead door 33. The lower door 30 is hinged on one of the
side walls 26 and locked by a side latch 51 and four wedge latches 53.
The vertical lower door 30 prevents feedback and spillage of material
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underneath the packer frame 20 when the packex 12 is against the
trailer 10. The door 30 is fitted with a rubber gasket (is not shown)
to seal the interior of the trailer and prevent seepage of liquids out
of the trailer. The door 30 may be side hinged to swing open or
bottom hinged for vertical opening. When closed the door 30 prevents
spillage of refuse from the trailer 10 as the trailer is separated
from the packer. The door 30 is opened when the refuse is to be
expelled or unloaded from the trailer. Door 33 includes a series of
articulated panels 34, a roller chain 38 and rollers 37 adapted to
slide in guide tracks 36. Guide tracks 36 are mounted on the sloped
side walls 52 and extend over the upper portions of side walls 26 of
the body 23.
A mechanism 35 for closing and opening the overhead door is
located at the top of the trailer under a cover panel 27. The
mechanism 35 as seen in Figure 5, includes a shaft 40 arranged in
bearings 41 attached to the cover panel 27. A roller sprocket 39 is
mounted on the shaft 40 and carries the roller chain 38. A second
sprocket 42 mounted on the end of the shaft 40 carries a loop of hand
chain 43. The mechanism 35 for opening and closing the overhead door
further includes two torsion springs 44 mounted on a shaft 48 and
connected to a drum 46 at one end and to a support 47 at the opposite
end. One torsion spring 44 can be seen in Figure 5; however, a second
such spring is mounted on shaft 48 at the opposite end thereof. The
torsion springs 44 are set up in the mechanism 35 to facilita~e the
upward movement of the overhead door.
The supports 47 are fixed to the shaft 48 and prevent
rotation of the ends of the torsion springs 44. The drums 46 freely
rotate about shaft 48 and rotate the opposite ends of the springs 44.
One drum 46 is shown in Figure 5 in relation to one of the springs 44,
however, a second drum, not shown, is mounted in the same manner at
the opposite end of shaft 48 or use in conjunction with the second
spring 44, also not shown. A pair of cables 49 is attached at one end
to the drums 46 and at their other ends to the bottom of the door 33.
With the door 33 in the closed position, the cables 49 are extended
and the springs 44 and 45 are in the coiled or tensioned position. As
the door is raised, the springs 44 tend to uncoil and wind the cables
49 on the drums 46. The uncoiling of the springs 44 takes up some of
the weight of the door 33, thus aiding in raising the door. When the
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door is lowered to the closed position, the cables 49 extend rotating
the drums 46 and winding or coiling the springs 44.
To open the overhead door 33 an operator rotates the hand
chain 43 which rotates the sprocket 42, the shaft 40 and the roller
sprocket 39. The sprocket 39 engages the roller chain 38 pulling the
chain and the overhead door 33 upwards. The rollers 37 slide in the
guide tracks 36 along the edges of the sloped walls 26 over the top of
the trailer. To close the door 33 the chain 38 is rotated in the
opposite direction. The roller sprocket 39 engages the chain 38 which
pulls the top of the door 33 downward closing the door.
In the use of the refuse compaction trailer of the invention,
the charging box 19 of the stationary packer is loaded with refuse.
The packing head 18 moves refuse from the charging box 19 into the
attached compaction trailer 10 through the opening in the rear of the
trailer by the force of hydraulic cylinder 21. The packer head 18
travels inside the compac*ion trailer 10 to achieve maximum loads and
force the refuse away from the extension 30. As the trailer fills,
pressure on the confined material increases causing it to be compacted
into a mass of reduced volume. When the loading is completed, the
trailer is moved away from the packer 12. The refuse in the trailer
expands due to its own resiliency. As the refuse expands, it falls
into the area between the sloped walls 52 rather than falling on the
ground as spillage. The door 33 is then closed.
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