NZ758320A - Improvements in Trailers and Combination Vehicles - Google Patents
Improvements in Trailers and Combination VehiclesInfo
- Publication number
- NZ758320A NZ758320A NZ758320A NZ75832019A NZ758320A NZ 758320 A NZ758320 A NZ 758320A NZ 758320 A NZ758320 A NZ 758320A NZ 75832019 A NZ75832019 A NZ 75832019A NZ 758320 A NZ758320 A NZ 758320A
- Authority
- NZ
- New Zealand
- Prior art keywords
- trailer
- axle
- vehicle
- steer
- self
- Prior art date
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- 241000282898 Sus scrofa Species 0.000 description 5
- 150000002500 ions Chemical class 0.000 description 4
- 230000000875 corresponding Effects 0.000 description 3
- 230000004048 modification Effects 0.000 description 2
- 238000006011 modification reaction Methods 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- 229940035295 Ting Drugs 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000005352 clarification Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
Abstract
A trailer for use in a combination vehicle for road transport of heavy goods. The trailer comprises a semi-trailer body adapted to carry the goods and which includes a trailing axle set at its rear. The trailer also includes a dog trailer mounted beneath the front of said semi-trailer body. The dog trailer comprises: ?- a first frame portion connected to the semi-trailer body by a first pivoting connection and carrying a rear axle set, ?- a second frame portion connected to the first frame portion by a second pivoting connection and carrying a front axle set, and ?- a drawbar assembly attached to the second frame portion by a third pivoting connection. og trailer comprises: ?- a first frame portion connected to the semi-trailer body by a first pivoting connection and carrying a rear axle set, ?- a second frame portion connected to the first frame portion by a second pivoting connection and carrying a front axle set, and ?- a drawbar assembly attached to the second frame portion by a third pivoting connection.
Description
Improvements in Trailers and Combination Vehicles
Field of the Invention
This invention concerns carrying road vehicles. It is particularly concerned
with such vehicles having a rigid truck or a prime mover towing
a trailer or a set of
trailers.
Background to the Invention
Articulated road vehicles come in many different forms and sizes. In general, the
longer the vehicle is, and the more wheels it has, the greater the load it can carry.
However road authorities regulate the load upon, and g of, axles to control the
loads placed on roads, and particularly bridges, so heavier and larger and longer
vehicles are restricted in their access to certain roadways. However with increased
length comes the antage of reduced low-speed manoeuvrability which is
required for travelling on existing roads, through ections and turning in
restricted . To increase low-speed manoeuvrability for a given length of
vehicle, the number of articulation points can be sed. But this generally
reduces the high-speed stability/manoeuvrability of the vehicle as does shortening the
length of the vehicle. There has historically thus been a trade-off between low-speed
vrability (swept path) and high—speed ity/manoeuvrability.
The present invention provides an improvement in that trade-off for the types of
vehicles concerned.
In this specification, the following explanations apply to certain terms. The terms
believed to be understood by one of ordinary skill in the art, but the explanations
provided for reference if clarification is required.
a) A “heavy goods combination vehicle” (sometimes abbreviated to
nation e”) is a heavy goods or road transport e with at least
one articulation point.
b) A “semi-trailer” is a towed vehicle unit of a heavy goods combination
vehicle whose means of attachment to the preceding vehicle unit (a prime
mover, another semi-trailer, or a converter dolly) results in some of its vertical
load being imposed on said preceding unit through a tow coupling and whose
rear is supported by a single axle or le axle set (tandem, tri or quad axle
set) located towards the rear.
c) An “axle set” or “axle group” is either:
— a group of axles, including their road wheels, beneath a vehicle unit in
ently close proximity to each other that their interactions with
the pavement beneath are considered to overlap, or
— a single axle including its road wheels mounted beneath a vehicle unit,
— as defined in the prevailing ort regulations and/or design rules.
A tandem axle set has two axles in close proximity, a tri-axle set has three
axles in close proximity, and a quad axle set has four axles in close proximity.
The axle sets described in this specification can have two
or four wheels on
each axle so, for example, a tandem axle
group can have either four or eight
wheels.
d) A “converter dolly” (also called a “dolly” or “forecarriage” or “pig trailer”)
is a towed vehicle unit of a heavy goods ation vehicle whose tow
coupling to the preceding vehicle unit (a rigid truck, a prime mover or a semitrailer
) results in little or none of its vertical load being imposed on said
preceding vehicle unit through the tow coupling (see below) and whose rear is
supported by a single axle or a tandem or le set located at or near to the
centre of the main load carrying area. The main load bearing or carrying area
of a converter dolly usually incorporates a tow coupling device (a quick
release fifth wheel coupling, ballrace turntable, or non-separable turntable) so
that the dolly may be mounted beneath the front of a semi-trailer body,
thereby converting the semi-trailer into a “trailer”. In some countries a
ter dolly is also known as a pivoting bogie, a dolly truck or a special
truck.
e) A “trailer” in a heavy goods combination. vehicle is a towed vehicle unit
that can be either a pig r, a semi-trailer, or a combination of a converter
dolly plus semi-trailer.
f) A “set of trailers” is two or more trailers connected to be towed one behind
the other.
g) In a heavy goods combination vehicle, a “truck” or “rigid truck” is a rigid
motor e constructed ily for the carriage of goods and having at
least two axles, four wheels and a gross laden mass of at least 12 tonnes.
h) A “dog trailer” is a trailer with two axle groups of which the front axle
group is steered by connection to the preceding vehicle unit by way of a
drawbar assembly.
i) A “pig trailer” is a trailer having one axle group near the middle of the
length of the goods or load carrying surface.
j) A “prime mover” is a motor vehicle unit of a heavy goods combination
vehicle built to tow a semi-trailer, a ter dolly or a trailer.
k) A “vehicle unit” is either a trailer, a semi-trailer, a converter dolly, or a
motor vehicle. Thus a combination vehicle has a plurality of such vehicle
units connected by an articulated coupling between each adjacent vehicle unit.
1) A ing” or “coupling assembly” is a mechanical assembly which
provides connection between one vehicle unit (the leading vehicle unit) and
another vehicle unit (the trailing vehicle unit) immediately behind. Typically
a first portion of the coupling is affixed to the leading vehicle unit, a second
portion of the coupling is affixed to the trailing vehicle unit and the first and
second ns are releasably or permanently connected.
m) A “fifth wheel coupling” or “fifth wheel ly” provides a connection
and means of articulation between a railer and the vehicle unit
immediately ahead (the towing unit). Typically, the coupling comprises a
kingpin and skid plate on the underside of the front of the semi-trailer, and a
horseshoe-shaped component called a fifth wheel or r plate on the rear
of the towing unit. These two components when coupled are locked together
using a quick release ism. When coupled, the kingpin is free to rotate
in the fifth wheel about an axis that is largely vertical and normal to the plane
of the goods carrying surface so providing articulation between the linked
vehicle units. The fifth wheel can tilt fore and aft on a horizontal pin (about a
transverse axis) thus providing for vertical angulation between linked vehicle
units. The fifth wheel is not free to tilt ys thereby roll coupling the
linked vehicle units. In practice there is some freeplay (or lash) in the
connection allowing some sideways tilt under heavy sideways loads and
usually evident only when the vehicle is close to rollover.
n) A “ballrace ble” is a type of coupling used to provide articulation
n a semi-trailer and the vehicle unit immediately ahead. In contrast to
a fifth wheel coupling it essentially provides no vertical or sideways tilt
n the vehicle units thereby attached. Ballrace bles are sometimes
fitted with a mechanical locking device to selectively prevent articulation.
The device, when fitted, is typically engaged to assist the driver when
reversing the vehicle.
0) A “drawbar assembly” is the portion of a dolly that connects the dolly’s
frame or chassis to the vehicle unit in front for towing purposes.
p) A “ringfeder” is a generic name (previously a trademark) commonly used
worldwide to identify a type of automatic bolt coupling device (pin-type
hitch/coupling) utilizing a swivelable cast bell portion with a horizontal
opening and a machined pin which connects to a towing eye located on the
front of a drawbar assembly. The connection between the towing eye and the
pin is a “rotationally free joint” equivalent to a ball joint. The hitch point of a
ringfeder coupling is at the longitudinal axis of the pin which engages with the
towing eye located at the front of the drawbar.
q) The “Gross ation Mass” (or GCM) of a combination vehicle is a
value specified by the manufacturer as being the maximum of the sum of the
maximum laden mass of the prime mover plus the sum of the Axle Loads of
all other vehicle units in the combination vehicle.
r) A “B-double” is a multi-articulated goods carrying vehicle comprising a
rear semi—trailer attached ly to a front semi-trailer, usually h a fifth
wheel coupling, and which is, in turn, attached directly to a prime
mover, also
y h a fifth wheel coupling.
s) An “A-double” is a multi-articulated goods carrying vehicle comprising a
rear ailer attached directly to a front semi-trailer, y h a
ringfeder coupling, which is, in turn, attached directly to a prime mover
usually through a fifth wheel or turntable coupling.
t) A “tow coupling overhang” refers to the distance that a hitch point is
located rearwards of the nt axle centre or axle
group . If the hitch
point is located forwards of the relevant axle centre or axle group centre, then
it can be considered as a negative tow coupling overhang.
Summary of the Invention
In one aspect, the invention provides a combination vehicle for road transport of
heavy goods, said vehicle comprising:
A r for use in a combination vehicle for road transport of heavy goods, said
trailer comprising:
— a semi-trailer body adapted to carry said goods and ing a trailing axle
set at its rear, and
— a dog trailer mounted beneath the front of said semi-trailer body,
said dog trailer comprising
— a first frame portion connected to said semi-trailer body by a first ng
connection and carrying a rear axle set,
— a second frame portion connected to said first frame portion by a second
pivoting connection and carrying a front axle set, and
— a drawbar assembly attached to said second frame portion by a third pivoting
connection.
Preferably said dog trailer has a first axle set and a second axle set spaced sufficiently
apart for them to be treated under ort regulations as separate axle sets.
The dog trailer may have two axle groups of which the front axle
group is steered by
connection to the preceding vehicle unit by way of said drawbar assembly.
Said first pivoting connection may be a fifth Wheel coupling or a turntable which
be a non-separable turntable or a quick release ble.
Preferably said second pivoting connection is a ballrace turntable.
ably said drawbar assembly pivots up and down from said second frame
portion.
Preferably said drawbar assembly has a der coupling portion at its front end.
Preferably said rear axle set has at least one self-steer axle lockable in the straight-
ahead position. In some preferred embodiments said rear axle set is a single axle.
In some preferred embodiments said second pivoting connection is a lockable
ble.
In another aspect, the invention provides a combination vehicle for road transport of
heavy goods, said vehicle comprising:
— a motor vehicle at the front, and
—- a trailer attached to said motor vehicle so as to be towed behind the motor
vehicle,
said trailer comprising:
— a semi-trailer body adapted to carry at least some of said goods,
— a trailing axle set ting the rear of the semi—trailer body, and
— a dog trailer mounted beneath the front of said semi-trailer body,
said dog trailer comprising:
— a first frame portion connected to said semi-trailer body by a first pivoting
connection and carrying a rear axle set,
— a second frame n connected to said first frame portion by a second
ng connection and carrying a front axle set, and
— a drawbar assembly whose rear end is attached to said second frame portion
by a third pivoting connection and which is coupled at its front end to the rear
of said motor vehicle.
In some preferred embodiments said motor vehicle is a rigid truck.
Said rear axle set may be a self-steering single axle.
Said combination vehicle may comprise means for locking said second pivoting
connection in the straight-ahead on at low road speeds and means for locking
said teering axle on the dog trailer in the straight-ahead position at high road
speeds.
In those embodiments the distance from the front axle of the motor vehicle to the rear
axle of said trailer is preferably not less than 17 metres.
Said trailing axle set may be a tandem axle set the rearmost axle of which is a self-
steer axle.
The rearmost axle in said trailing axle set may be a self-steer axle and the e
includes means to lock said rearmost self—steer axle in the straight ahead position at
high speeds.
In those embodiments the distance from the front axle of the motor vehicle to the rear
axle of said trailer is ably not less than 18.333 metres.
In a further aspect, the invention provides a method of operating a combination
vehicle for road transport of heavy goods, said vehicle comprising:
— a motor vehicle at the front, and
— a r attached to said motor e so as: to be towed behind the motor
vehicle,
said trailer comprising:
— a semi-trailer body adapted to carry at least some of said goods,
— a trailing axle set supporting the rear of the semi-trailer body, and
— a dog trailer mounted beneath the front of said semi-trailer body,
said dog trailer comprising:
— a first frame portion connected to said semi-trailer body by a first pivoting
connection and carrying a rear axle set,
— a second frame portion connected to said first frame portion by a second
pivoting connection and carrying a front axle set, and
— a drawbar assembly whose rear end is attached to said second frame n
by a third pivoting tion and whose front end is coupled the rear of said
motor vehicle;
said method comprising selectively locking and unlocking the pivotal action of said
first and second pivoting connections in response to preset ranges of road speeds
during d motion of the vehicle.
In said method:
- said second pivoting connection
may be a lockable turntable, and
- said rear axle set may be a self-steer rear axle,
and said method preferably comprises:
- at selected high road speeds, unlocking said lockable turntable forming the
second pivoting connection so it is free to rotate as induced by the motion of
the vehicle, and locking said teer rear axle into the straight-ahead
position, and
- at selected low road speeds, locking said turntable forming the second
ng connection into its straight-ahead position and unlocking said self-
steer rear axle so it is free to steer as induced by the motion of the e.
ably:
— said trailing axle set is a tandem axle set the st axle of which is
a self-
steer axle,
and said method ses:
—- at said high road speeds, locking said rearmost axle into the ht-ahead
position, and
— at said low road speeds, unlocking said rearmost axle so it is free to steer as
induced by the motion of the vehicle.
Said motor vehicle may comprise a leading semi—trailer the
rearmost axle of which is
a self-steer axle, and said method may comprise:
- at said high speeds, locking said leading semi--trailer’s rearmost self—steer axle
into the straight-ahead position; and
- at said low speeds unlocking said leading semi-trailer’s rearmost self-steer
axle so it is free to steer as induced by the motion of the vehicle.
Alternatively in said method:
- said first ng connection is a first lockable turntable,
- said second pivoting connection is a second lockable turntable, and
- said rear axle set is a self-steer axle,
and said method includes:
- at a selected range of high road speed conditions unlocking said first and
second lockable turntables so they are free to rotate as induced by the motion
of the vehicle, and
- g said self-steer rear axle into the straight-ahead position.
Alternatively in said method:
- said first pivoting connection is a first lockable turntable,
- said second pivoting connection is a second lockable turntable, and
- said rear axle set is a self—steer axle,
and said method includes:
- at a selected range of high road speed conditions, locking said first lockable
turntable into the straight-ahead position,
- and unlocking the self-steer axle so it is free to steer as induced by the motion
of the vehicle.
Alternatively in said method:
- said first pivoting connection is a first lockable turntable,
- said second pivoting connection is a second lockable turntable, and
— said rear axle set is a lockable self-steer axle,
and said method es at a selected range of high road speed ions:
said first le ble so
, unlocking it is free to rotate as induced by the
motion of the vehicle, and
- locking said self-steer rear axle into the ht-ahead position.
Brief ption of the Drawings
In order that the invention may be more fully understood there will now be described,
by way of example only, preferred embodiments and other elements of the invention
with reference to the accompanying drawings Where:
Figure 1 is a view of a preferred trailer according to a first embodiment of the
present invention;
Figure 2 is part ed view of the r shown in Figure 1 separated into
dog trailer and semi-trailer ns;
Figure 3 is a further exploded View of the dog trailer portion shown in Figure 2;
Figures 4A to 4G show additional trailers which are alternative embodiments of
the invention;
Figures 5A to SC show successively exploded views of the trailer shown in
Figure 4B;
Figures 6A to 6C show successively exploded views of the trailer shown in
Figure 4C;
Figures 7A to 7E show truck-plus-trailer combination vehicles ing to
further embodiments of the invention which incorporate various trailers shown
in Figures 4A to 4G, and with the illustrations annotated to indicate the
allowable loads at each axle set;
Figure 8 is an enlarged view of the vehicle shown in Figure 7A which is one
preferred embodiment of the invention;
Figure 9 is an ed View of the vehicle shown in Figure 7B which is another
red embodiment of the invention;
Figure 10 is a visual key to the relationship between vehicles shown in Figures
10A to 10M;
Figures 10A to 10G show a comparison of the load ng capacities of a
selection of existing A-double combinations es 10A, 10B and 10C), when
compared to alternative vehicles (Figures 10D, 10E, 10F and 10G) according to
additional embodiments of the present invention, and showing below each axle
set the load carrying capacity of that axle set;
Figures 10H to 10M show some additional configurations according to further
embodiments of the invention, together with the load carrying capacities at each
axle set;
Figure 11 shows a particularly preferred combination vehicle according to a
further embodiment of the invention, when compared with a version of the
invention ntially the same as that shown in Figure 8, showing the
preferred state of the lockable ble and lockable self-steer axle at high and
low road speeds;
Figure 12 shows a further particularly preferred combination e according
to a r embodiment of the invention when compared with
a version of the
invention substantially the same as that shown in Figure 9, showing the
preferred state of its lockable turntable and lockable self-steer axles at high and
low road ;
Figure 13 shows another particularly preferred combination vehicle
according
to a further embodiment of the invention being; compared with
a version of the
invention substantially the same as that shown in Figure 10D, showing the
red state of its lockable turntable and lockable self-steer axles at high and
low road speeds;
s 14, 15 and 16 show three different operating modes of another trailer
according to a further embodiment of the invention;
Figure 17 is another view of the trailer in Figures 14 to 16 and is shown for ease
of ison with the trailers in Figures 18 and 19; and
Figures 18 and 19 show two other rs according to further embodiments of
the invention.
The drawings are tics only and are not necessarily all to the same scale.
Where an axle is shown with a X across a wheel, it indicates that is a self-steering
axle.
With respect to the different embodiments of the invention, features which have
equivalent function in each ment are identified by numerals which are
hundred different from the numerals identifying equivalent features in the other
embodiments.
Discussion of Embodiments of the Invention
In regard to the trailer embodiment shown in Figures 1 to 3, and the use of that trailer
in the combination vehicle embodiment shown in Figure 8, the trailer 100 is
constructed for use in a combination vehicle 130 for road transport of heavy
goods.
The trailer 100 is shown carrying goods 104. The r 100 comprises a semi-trailer
body 102, including a goods carrying area 101, and having a single axle 103 complete
with road wheels 126, at the rear of the r g
a trailing axle set 105. A dog
trailer 106, that does not have a goods carrying
area, is mounted h the front 108
of the body 102.
The dog trailer 106 comprises a first frame portion 110 and
a second frame portion
114. The first frame portion is connected to the semi-trailer body 102 by
a coupling
112, which is shown as a quick release fifth-wheel coupling in Figures 1-3 and 8. A
non-separable turntable coupling may be used as an alternative. The coupling 112
functions as a pivoting connection between the semi-trailer body and the first frame
portion 110 and roll-couples the semi-trailer body 102 and the dog trailer 106. That
means the railer body 102 and the first frame portion 110 will rollover together
through turntable ng 112. The roll-coupled connection between semi-trailer
body 102 and trailer 106 is commonly referred to as a “B-type” tion.
The coupling 112 allows steering rotation of the dog r 106 about
a vertical axis
h the coupling. The coupling also allows the dog trailer to pivot through a
limited range (about plus or minus 20°) about a transverse axis relative
to the semi-
trailer body 102 thereby ensuring sharing of loads between the trailer’s front
axle 124
and rear axle 122.
The second frame portion 114 is connected to the first frame portion 110 by
a ballrace
turntable 116 which forms a second pivoting connection, this time between
the first
frame portion 110 and the second frame n 114. A single rear axle 122,
complete with road wheels 126, extends across the rear of the first frame portion 110
to form a rear axle set 123 for trailer 106. A front axle 124, complete with road
wheels 126, extends across the second frame portion 114 to form
a front axle set 125
for the trailer 106. This creates a single axle dolly at the front of the trailer 106.
The rear end 120 of a drawbar 118 is pivotally attached to the front 119 of
the second
frame portion 114 so as to form a third pivotal connection 121
on the trailer 100. The
trailer 106 can therefore be ered as having a dog trailer configuration.
As shown in Figure 3, the first frame n 110 of trailer 106 is a semi-trailer
chassis, which does not have a goods carrying area but instead has a turntable in the
form of a fifth wheel connector to support a load, while the second frame portion 114
in conjunction with the drawbar 118 forms a single-axle dolly (or pig
trailer/truck/forecarriage) 127 coupled to the first frame portion 110 through the
ballrace turntable 116.
As shown in Figure 8, the front end of the drawbar 118 comprises a coupling portion
129 which mates with a corresponding coupling n 131 on a towing vehicle 128.
In use the drawbar 118 attaches to a motor vehicle, which is a rigid truck 128 in
Figure 8, and which provides propulsion for the combination vehicle 130. The
attachment is via a ringfeder pin or ball-type coupling, pintle hitch, or equivalent at
the front of the drawbar 118. There is no roll-coupling through coupling portion 129
between the trailer 100 and truck 128, and therefore the trailer 100 and truck 128 can
each rollover independently of the other. Where there is no oupling h a
coupling assembly, the connection is commonly referred to as an “A-type”
connection.
The trailer 100 described above, comprising a two axle dog trailer 106 coupled
through an A-type connection to the towing e 128 and coupled h a
B-type connection 116 to a towed goods carrying semi-trailer 102 is described,
cally hereinafter, as an “AB trailer”. This is e the trailer 106 has an A-
type coupling to the towing vehicle and has a B-type coupling to the goods carrying
semi-trailer.
The ation vehicle 230 shown in Figure 9 comprises a truck 228 the same as
that in Figure 8 plus a trailer 200 having a two axle lead (dog) trailer 206 the same as
that in Figure 8. However the trailing axle set 205 of the trailer 200 is a tandem axle
set in order to provide a greater GCM.
As can be seen from Figures 4B, 5A, 5B and 5C, the trailer 300 shown in Figure 4B
shares many characteristics in common with the trailer 200 shown in Figures 4A and
9. The trailer 300 comprises a semi-trailer body 302, having a tandem axle set 305
forming a trailing axle set, plus a trailer 306 mounted beneath the front 308 of the
body 302. The trailer 306 comprises a first frame portion 310 and a second frame
portion 314. The first frame portion is connected to the semi-trailer body 302 by a
quick release fifth wheel turntable or a non-separable turntable coupling 312 which
forms a B-type ng between the semi-trailer body 302 and the first frame portion
310 of the r, and which ons as a pivoting connection between the semi—
trailer body 302 and the first frame portion 310.
The second frame portion 314 is connected to the first. frame portion 310 by a ballrace
turntable 316 which forms a second pivoting tion, this time between the first
frame portion 310 and the second frame portion 314.
A drawbar 318 is pivotally attached at its rear end 320 so as to form a third pivotal
connection on the trailer 300. As in other embodiments described above, the trailer
306 can therefore be considered as a dog trailer ration.
A tandem axle set 322 extends across the rear of the first frame portion 110. A front
axle set 324 s across the second frame portion.
The trailer 300 therefore has the form of a 5-axle AB-trailer.
As can be seen from Figures 4C, 6A, 6B, and 6C, the trailer 400 shown therein shares
many features with the previously described trailer 300. The most cant
difference is that in the tandem axle set 403 on the semi-trailer body, and in the
tandem axle set 422 on the dog trailer 406, the respective back axles 432 and 434 are
self-steering axles. The trailer 400 is therefore a 5-axle AB-trailer with two self-steer
axles.
In all the embodiments shown in Figures 7A to 7E, the truck 128 is the same. Under
current Australian legislation it has a maximum allowable load of up to 6.5 tonnes on
the front axle and a maximum allowable load of up to 17 tonnes on the rear tandem
axle set.
In each of Figures 7A to 7E the allowable load for each axle set in the vehicles is
shown below the respective axle set. The minimum lengths (front axle to trailing
axle) for each configuration in some jurisdictions in Australia are:
Fig 7A truck and 3-ax1e AB-trailer min length 1700 mm
Fig 7B truck and 4-axle AB-trailer min length 18333 mm
Fig 7C truck and S-axle iler min length 23333 mm
Fig 7D truck and 6-ax1e AB-trailer min length 25667 mm
Fig 7E truck and 5-axle AB-trailer with self-steer axles min length 23333 mm
Although the actual ble loads and the minimum lengths may vary from
jurisdiction to jurisdiction, the loads and dimensions stated are generally indicative.
The embodiment in Figure 7C has the first frame portion 310 extended when
compared to the corresponding ent 110 in Figures 7A and 7B. The front axle
on the trailer 306 ses a single axle set. The rear axle set 323 on the trailer 306
is a tandem axle set at the rear of the frame portion 310. The tandem axle set and the
single axle set are spaced sufficiently apart that they are treated as individual axle
groups for the purposes of ating allowable loads.
The trailer 400 shown in Figure 7E is similar overall to the configuration of the trailer
300 in Figure 7C. Both-are 5-axle AB-trailers. But, the rearmost axle 434 on the dog
trailer 406 is a self-steer axle, which aids reduction of the swept path width during
low speed turns. The trailer 400 also has a teering axle 432 at the rear of the
semi—trailer, which similarly helps to reduce off-tracking in low-speed turns. Where
self-steer axles are used in the manner described it is often preferable to lock them
on-centre (zero steer angle) when travelling at high speed to improve high—speed
stability and manoeuvrability.
The r 500 in Figure 7D has a e set at its rear, to increase its allowable load,
but is otherwise the same as the trailer 300. It is a 6-axle AB-trailer.
Figures 4C to 4G illustrate larger capacity versions of trailers according to the
invention and, in the case of 4E, how the function of the trailer may be divided
between two trailers, forming a B—double semi-trailer pair, in order to
carry an even
greater load.
The combination vehicles shown in Figures 10A to 10G are of even larger capacity.
The vehicles in Figures 10A, 10B and 10C are all of an A-double configuration,
already known to industry and those skilled in the art. The vehicles in Figures 10D,
10E, 10F, and 10G are all in accordance with different ments of the present
invention and the AB-trailer concept. As can be seen from the visual key Figure 10,
the vehicles in Figures 10A, 10B and 10C correspond to Figures 10D, ICE, and 10G
respectively which have an AB-trailer. The load ng capacities shown in the
Figures are based on current m axle group load limits as indicated when
approved to operate on some roadways in Victoria, lia.
The lead dog-trailer in each AB-trailer always has two axle sets and a main s
that supports a ble free to pivot about a transverse axis. The front axle set on
the dog trailer typically has a single axle but it may also be a tandem axle set. The
rear axle set on the dog trailer may be a single axle, a tandem axle set or a tri-axle
axle set.
All of the trailers 100, 200, 300, 400, 500, 600, 700, and 800, can be considered to be
AB-trailers. As noted before, this is because the drawbar has an A-type coupling to
the towing vehicle and has a B-type coupling to the goods carrying semi—trailer or
trailers.
The combination vehicle 530 shown in the lower portion of Figure 11 has for its
motor vehicle the same rigid truck 128 as in combination e 130. The trailer 500
in vehicle 530 has substantially the same configuration as the trailer 100 in Figure 1
except for two significant features. The ballrace turntable 516 is lockable in the
straight—ahead position whereas turntable 116 has no such locking feature. Also the
rear axle 522 on the dog trailer 506 is a le self-steer axle whereas the
corresponding axle 122 is not a teer configuration. When operating the
combination vehicle 530 incorporating the trailer 500, at low road speed:
- the ballrace turntable 516 is locked in the straight-ahead position, and
- the teer axle 522 is unlocked,
while at high road speed:
- the turntable 516 is unlocked, and
- the self-steer axle 522 is .
The term “low speed” when used above refers to that speed below which vehicle
stability and dynamic effects are no longer a safety issue under typical vice
operation. That speed is usually somewhere in the
range 30 to 60 km/hr. The term
“high speed” means above about 30 to 60 km/hr.
By incorporating the lockable turntable 516 and self-steer axle 522 into the r
500, the low speed swept path of the trailer and offtracking is advantageously reduced
and its high speed performance is improved, so making the combination vehicle
more
stable and its tracking improved.
The combination e 630 shown in the lower portion of Figure 12 has
the same
rigid truck 228 as in combination vehicle 230. The trailer 600 in vehicle 630 is
mostly the same as the trailer 200 shown in Figure 9 except that its dog trailer
component 606 has the same modifications as described above for trailer 500. In
particular the ballrace turntable 616 is lockable in the straight-ahead position, and the
rear axle 622 is a lockable self-steer axle. In addition, the back axle 632 in the
ng axle set 603 is also le. When operating the combination vehicle 630
incorporating the trailer 600, the turntable 616 and self-steer axles 622 and 632 are
locked and unlocked according to speed as indicated by the annotations
at the bottom
of Figure 12.
The ation vehicle 730 shown in the lower portion of Figure
13 has for its
motor vehicle 728 a combination vehicle comprising a prime mover 738 and
semi-trailer 740. The trailer 700 in vehicle 730 has the same configuration
as the
trailer 600 shown in Figure 12. The rear axle 732 on the trailing tandem axle set 705
is a lockable self-steer axle which in use is controlled in the same manner as the
self-steer axle 722 on the dog trailer 706. The leading semi-trailer 740 forming part
of the motor vehicle 730 also has a tandem axle set 742 the rear axle of which is a
self-steer axle 744.
When ing the combination vehicle 730 incorporating the trailer 700, at low
road speed (such as below about 30 km/hr):
- the ballrace turntable 716 is locked in the straight-ahead on, and
- the self-steer axles 722, 732 and 744 are unlocked,
while at high speed (above about 30 km/hr):
— the turntable 716 is unlocked, and
- the self-steer axles 722, 732 and 744 are locked in the straight-ahead position.
This provides even greater improvements in low-speed mance when compared
with the trailer 300.
Switching between the low speed and high speed locking conditions can be controlled
tically from the motor vehicle or from a microcontroller mounted on the
trailer.
The trailer 800 shown in s 14, 15 and 16 is the same as the trailer 100 in Figure
1 except that the turntables 812 and 816 are both lockable in the straight-ahead
position, and the rear axle 822 on the dog trailer 806 is a self-steering axle which is
le in the straight-ahead position. In use, ion controls operating from the
motor vehicle (or on-board micro-controller) automatically activate and deactivate the
locks on the self-steering axle 822, and the turntables 812 and 816 such that:
- as indicated in Figure 14, at high-speed in one operating mode the first and
second lockable turntables are unlocked, and thus free to rotate (articulate),
and the self-steer rear axle 822 is locked into its straight-ahead position;
- as indicated in Figure 15, at high-speed in another operating mode, the first
turntable 812 is locked while the second turntable 816 is unlocked and the
axle 822 is unlocked;
- as indicated in Figure 16, at high-speed in a fiirther operating mode, the first
turntable 812 is unlocked, the second ble 816 is locked, and the rear
self-steering axle 822 is locked.
Locking and unlocking the turntable 812, and the self-steer axles 822 as described for
Figures 14, 15, and 16 allows the effective wheelbases of the component vehicle units
to be beneficially varied as desired while on the move. Each of the three peed
operating modes has particular characteristics and the one that is selected will depend
on the stability teristics of the combination vehicle.
The effective wheelbases for the embodiments shown in Figures 14 to 16 are
indicated by the distances marked WB1, WB2, and WB3. In Figure 14, the distance
WB1 is the wheelbase for the dog trailer’s dolly 827 (effectively the drawbar length),
the distance WB2 is the dog r’s wheelbase portion, and WB3 is the wheelbase of
the goods carrying semi—trailer 802.
In Figure 15, where the first turntable 812 is locked, the length of wheelbase WB3 is
increased. The longer wheelbases provide additional stability for the trailer at high
road speeds.
In regard to the trailer configuration shown in Figure 16, when at high road speed,
both the second turntable 816 and the self-steer axle 822 are locked while the first
turntable 812 is unlocked. The dog trailer 806 then becomes a dolly (or pig trailer)
with a long drawbar 818 and a wide spread of axles in the tandem. There is an
increase in the effective wheelbase WBI.
Included in Figures 17 to 19 are tions g the locked/unlocked status of
the respective self—steer axles and lockable turntables for both eed and high-
speed al operating modes of the respective trailers.
The trailer 800 shown in Figure 17 has the same construction as trailer 800 shown in
Figures 14, 15 and 16. But the tabulated annotations included in Figure 17 give
s for six different locking statuses for the combination of the second turntable
(column 2), first turntable n 3), and rear axle (column 4). The table in Figure
17 includes the g statuses for Figure 14 at line 1, for Figure 15 at line 2, and for
Figure 16 at line 3, these all being for different configurations when operating at high
road speeds. The table in Figure 17 also shows, at lines 4, 5 and 6, the locking
statuses for three different configurations when operating at low road speeds and
which affect offtracking in a turn, low-speed turn and swept path width.
For most ements it is likely that only a single configuration of locking statuses
would be used at high speed, and a single configuration of locking statuses used at
low speed for a given trailer in a given combination vehicle.
But the same trailer in a different combination vehicle, or perhaps undergoing a
different duty in the same combination vehicle, may be operated with an alternative
configuration of locking statuses.
Alternatively, for more sophisticated ements, the trailer may be operated with
two or more of the high speed locking rations being invoked sequentially as
travelling ions . Similarly, two or more of the low speed locking
configurations may be invoked sequentially as low speed travelling conditions
The trailer 900 in Figure 18 is substantially the same as trailer 200 in Figure 9 except
that for the trailer in Figure 18 the rear axle 922 on the dog trailer is a lockable
self-steering axle, and the first and second turntables are each lockable in the
straight-ahead position.
The tabulation included as portion of Figure 18 shows, in a similar manner to Figure
17, details of 6 different statuses for the combination of the second turntable 916, first
turntable 912 and rear axle 922 for the trailer 900.
The trailer 1000 in Figure 19 is the same as the trailer 900 in Figure 18 except that the
last axle 1032 in trailer 1000’s trailing axle set 1005 is a self-steer axle which is
lockable by control from the motor vehicle or onr-board microcontroller. When
ing at low road speed the rearmost teer axle is preferably always unlocked
to reduce offtracking and swept path width in a turn.
The tion included as portion of Figure 19 shows in a similar manner to Figure
17, details of 6 different locking statuses for the combination of the second turntable
1016, first turntable 1012 and rear axle 1022 and trailing axle 1003 for the r
1000.
While the above description includes the preferred ments of the invention, it is
to be understood that many variations, alterations, modifications and/or additions
be introduced into the constructions and arrangements of parts previously described
without departing from the essential features or the spirit or ambit of the invention.
It will be also understood that where the word “comprise”, and ions such as
“comprises” and “comprising”, are used in this specification, unless the context
requires otherwise such use is ed to imply the inclusion of a stated feature or
features but is not to be taken as excluding the presence of other feature or features.
The reference to any prior art in this specification is not, and should not be taken
an acknowledgment or any form of suggestion that such prior art forms part of the
common general knowledge of persons skilled in the art.
Claims (26)
1. A trailer for use in a combination e for road transport of heavy goods, said trailer comprising: — a semi-trailer body adapted to carry said goods and including a trailing axle set at its rear, and — a dog r mounted h the front of said semi-trailer body, said dog trailer comprising: — a first frame portion connected to said semi-trailer body by a first pivoting 10 connection and carrying a rear axle set, — a second frame portion connected to said first frame n by a second pivoting connection and carrying a front axle set, and — a drawbar assembly attached to said second frame portion by a third pivoting connection.
2. A trailer according to claim 1 wherein said dog trailer has two axle groups of which the front axle group is steered by connection to the preceding vehicle unit by way of said drawbar assembly. 20
3. A trailer according to claim 1 or 2 wherein said first pivoting connection is a quick release turntable.
4. A trailer ing to claim 1 or 2 wherein said first pivoting connection is a non-separable turntable.
5. A r according to claim 1 or 2 wherein said first pivoting connection is a fifth wheel coupling.
6. A trailer according to any one of the previous claims wherein said second 30 ng connecting is a ballrace turntable.
7. A trailer according to any one of the previous claims wherein said drawbar assembly pivots up and down from said second frame portion.
8. A trailer according to any one of the previous claims wherein said drawbar ly has a ringfeder coupling portion at its front end.
9. A trailer ing to any one of the previous claims wherein said rear axle set has at least one self—steer axle lockable in the straight-ahead position.
10 10. A trailer according to any one of the previous claims wherein said rear axle set is a single axle.
11. A trailer ing to any one of the previous claims wherein said second ng connection is a lockable turntable.
12. A combination vehicle for road transport of heavy goods, said vehicle comprising: — a motor vehicle at the front, and — a trailer attached to said motor vehicle so as to be towed behind the motor 20 vehicle, said trailer comprising: — a semi-trailer body adapted to carry at least some of said goods, — a ng axle set supporting the rear of the semi-trailer body, and — a dog trailer mounted h the front of said semi-trailer body, 25 said dog trailer comprising: — a first frame portion connected to said semi-trailer body by a first pivoting connection and ng a rear axle set, — a second frame portion connected to said first frame portion by a second pivoting connection and carrying a front axle set, and 30 —— a drawbar assembly whose rear end is attached to said second frame portion by a third pivoting connection and which is coupled at its front end to the rear of said motor vehicle.
13. A combination vehicle according to claim 12’. wherein said motor vehicle is a rigid truck.
14. A combination vehicle according to claim 12 or 13 n said rear axle set is a self-steering single axle.
15. A combination vehicle according to claim 12 comprising means for locking said second ng connection in the straight—ahead position at low road speeds and 10 means for locking said self-steering axle on the dog trailer in the straight-ahead position at high road speeds.
16. A combination vehicle ing to claim 15 in which the distance from the front axle of the motor vehicle to the rear axle of said trailer is not less than 17 15 metres.
17. A combination vehicle according to any one of claims 12 to 16 wherein said ng axle set is a tandem axle set the rearmost axle of which is a self-steer axle. 20
18. A combination vehicle ing to claim 17 n the rearmost axle in said trailing axle set is a self-steer axle and said vehicle includes means to lock said rearmost self-steer axle in the straight ahead position at high speeds.
19. A combination vehicle according to claim 17 or 18 in which the distance from 25 the front axle of the motor vehicle to the rear axle of said trailer is not less than 18.333 metres.
20. A method of operating a combination vehicle for road ort of heavy goods, said vehicle comprising: 30 — a motor vehicle at the front, and — a trailer attached to said motor vehicle so as to be towed behind the motor vehicle, said trailer comprising: a semi-trailer body d to carry at least some of said goods, a ng axle set supporting the rear of the semi-trailer body, and a dog r mounted beneath the front of said semi-trailer body, said dog trailer comprising: a first frame portion connected to said semi-trailer body by a first pivoting connection and carrying a rear axle set, a second frame portion connected to said first frame portion by a second pivoting connection and carrying a front axle set, and 10 a drawbar assembly whose rear end is attached to said second frame portion by a third pivoting connection and whose front end is coupled to the rear of said motor e; said method comprising selectively locking and unlocking the pivotal action of said first and second pivoting connections in response to preset ranges of road speeds 15 during forward motion of the vehicle.
21. The method according to claim 20 wherein: said second pivoting connection is a le turntable, and said rear axle set is a self-steer rear axle, 20 and said method comprises: at selected high road , ing said lockable turntable forming the second pivoting connection so it is free to rotate as induced by the motion of the vehicle, and g said self-steer rear axle into the straight-ahead position, and 25 at selected low road speeds, locking said turntable forming the second pivoting connection into its straight-ahead position and unlocking said self- steer rear axle so it is free to steer as induced by the motion of the vehicle.
22. The method according to claim 21 wherein: 30 said trailing axle set is a tandem axle set the rearmost axle of which is a self- steer axle, and said method comprises: at said high road speeds, locking said rearmost axle into the straight-ahead position, and at said low road speeds, unlocking said rearmost axle so it is free to steer as induced by the motion of the e.
23. The method according to claim 21 or 22 wherein said motor vehicle comprises a g semi—trailer the rearmost axle of which is a self-steer axle, and said method comprises: at said high road , locking said leading railer’s st self-steer 10 axle into the straight-ahead position; and at said low road speeds unlocking said leading semi-trailer’s rearmost self- steer axle so it is free to steer as induced by the motion of the vehicle.
24. The method according to claim 20 wherein: 15 said first pivoting connection is a first lockable turntable, said second pivoting connection is a second lockable turntable, and said rear axle set is a self-steer axle, and said method comprises: at a selected range of high road speed conditions, ing said first and 20 second lockable turntables so they are free to rotate as induced by the motion of the vehicle, and locking said self—steer rear axle into the straight-ahead position.
25. The method according to claim 20 wherein: 25 said first pivoting connection is a first lockable turntable, said second pivoting tion is a second lockable turntable, and said rear axle set is a self-steer axle, and said method comprises: at a selected range of high road speed conditions, locking said first lockable 30 turntable into the straight-ahead position, and unlocking the self-steer axle so it is free to steer as induced by the motion of the vehicle.
26. The method according to claim 20 wherein: - said first pivoting connection is a first lockable turntable, - said second pivoting connection is a second lockable turntable, and - said rear axle set is a lockable self-steer axle, and said method comprises, at a selected range of high road speed conditions: — unlocking said first lockable turntable so it is free to rotate as induced by the motion of the e, and — locking said teer rear axle into the straight-ahead position.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2018903943 | 2018-10-18 |
Publications (1)
Publication Number | Publication Date |
---|---|
NZ758320A true NZ758320A (en) |
Family
ID=
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