Highway train

In a highway train, a wheeled and steerable, motor-driven vehicle is combined with at least a first load carrier having its forward end portion rested on a first "fifth wheel" supported by the rear portion of the tractive vehicle. An auxiliary wheeled vehicle has a front portion with a second "fifth wheel" supporting the rearward end portion of the first load carrier. A second load carrier has its forward end portion rested on a third "fifth wheel" supported by a rear portion of the auxiliary vehicle. An additional wheeled vehicle supports the rear end portion of the second load carrier. While en route, the first load carrier is supported solely by the first and second "fifth wheels" in such a manner that it is free to occupy a limited angular position in a generally horizontal plane, relative to both the tractive vehicle and the auxiliary vehicle. The auxiliary vehicle has fixed front wheels and rear wheels which are turned through a steering mechanism, in response to any horizontal angular displacement occurring between the first load carrier and the auxiliary vehicle, as when the train passes through a curve. In this manner, the auxiliary vehicle always returns itself into a straight line position with respect to the first load carrier.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention is concerned with highway trains of the kind in which a 
wheeled and steerable, motor-driven tractive vehicle having a rear portion 
is combined at least with a first load carrier having a forward end 
portion and a rearward end portion of which said forward end portion is 
rested on said rear portion of the tractive vehicle through the 
intermediary of a first pivot device capable of permitting horizontal 
angular displacement between said first load carrier and said tractive 
vehicle, an auxiliary vehicle having a front portion and a rear portion 
each of which is supported by at least one associated wheel axle having at 
least two wheels, said front portion of said auxiliary vehicle supporting 
said rearward end portion of said first load carrier through the 
intermediary of a second pivot device capable of permitting horizontal 
angular displacement between said auxiliary vehicle and said first load 
carrier, a second load carrier having a forward end portion and a rearward 
end portion of which said forward end portion is rested on said rear 
portion of said auxiliary vehicle through the intermediary of a third 
pivot device capable of permitting horizontal angular displacement between 
said second load carrier and said auxiliary vehicle, and an additional 
wheeled vehicle supporting said rearward end portion of said second load 
carrier, and in which all said vehicles and load carriers are separable 
from each other and said load carriers are interchangeable with one 
another. 
If needed, such a highway train may be extended by making said additional 
wheeled vehicle generally similar to said auxiliary vehicle so that it 
will be able to support by its front portion said rearward end portion of 
said second load carrier though the intermediary of a fourth pivot device 
similar to said second one, by adding a third load carrier having a 
forward end portion and a rearward end portion of which said forward end 
portion may be rested on a rear portion of the additional wheeled vehicle 
thus designed through the intermediary of a fifth pivot device similar to 
said third one, and by also adding a further wheeled vehicle capable of 
supporting the rearward end portion of said third load carrier and 
bringing up the rear of the train, said third load carrier then being 
interchangeable with any one of said first and second load carriers 
although not necessarily being identical to any one of them. 
Apparently a highway train of this kind may, whenever necessary, for 
instance when arriving at a station where only one of the load carriers is 
to be left for loading or unloading, be divided and reduced before 
continuing its journey to a further station. Also, if the train is 
supplemented with certain simple draw bars adapted to replace the load 
carriers as will be more closely described hereinafter, all its load 
carriers may be left at a desired station while only some, or all, of the 
supporting vehicles are transferred to another station for taking care of 
another group of load carriers. 
2. Description of the Prior Art 
In the past many different kinds of highway trains drawn by a tractive 
vehicle having a first pivot device, commonly known as a "fifth wheel" on 
its rear portion have been suggested. In most of these trains part of the 
total load is carried by a semitrailer having its forward end portion 
rested on the tractive vehicle and its rearward end portion supported by 
at least one fixed wheel axle, while the remainder of the load is carried 
by at least one ordinary trailer linked to the semitrailer through a draw 
bar and having at least one rear axle with fixed wheels and at least one 
front axle with steerable wheels following the direction of the draw bar. 
These trains, although extensively used, are unsatisfactory from many 
points of view, in particular because all the trailing vehicles have their 
own permanent wheel equipments which cannot be used for other 
transportation tasks when the frequently time-consuming loading and 
unloading of the cargo from the vehicles take place. In addition, these 
trains have a tendency to take a short cut when passing through sharp 
curves. 
In other highway trains drawn by a tractive vehicle of the type already 
referred to certain load carriers having no wheel of their own and 
commonly in the form of shipping containers are provided with specially 
designed, separate supporting wheel axle units adapted to be connected to 
and disconnected from the lower sides of the load carriers in order to 
temporarily turn the latter into trailing vehicles which may be drawn in 
tandem in a certain order. In a typical train of this kind the first load 
carrier has its forward end portion rested on the tractive vehicle in 
semitrailer fashion and its rearward end portion supported by a 
four-wheeled undercarriage which is displaceable longitudinally of the 
load carrier between two operative and lockable positions in the rearmost 
one of which a "fifth wheel" on the undercarriage is exposed for receiving 
and supporting the forward end portion of a second load carrier also 
forming a kind of semitrailer by having attached under its rearward end 
portion a removable wheel axle unit. However, in all the trains of this 
class it is a fairly inconvenient and timeconsuming task to attach and 
remove the supporting wheel axle or undercarriage units from the load 
carriers, and also these trains behave objectionably on the road. 
Further it has been suggested that in still another kind of highway train 
intended to be drawn by a tractive vehicle of the type referred to a pair 
of specially designed trailers each having at least two longitudinally 
movable supporting wheel axle units of their own with fixed wheels, i.e. 
wheels which cannot be turned for steering purposes, and each having both 
its forward and its rearward end portions adapted for connection to a 
"fifth wheel", such as the one on the tractive vehicle, are combined with 
an auxiliary vehicle having at least four fixed running wheels mounted on 
wheel axles which are displaceable longitudinally of the vehicle frame and 
in addition thereto two "fifth wheels", one on its front portion and 
another one on its rear portion. On the highway this train at its best and 
after several wheel axle displacements will be able to act as a 
combination of three semitrailers in tandem with the auxiliary vehicle 
forming the second one and having its forward end portion suspended from 
the rearward end portion of the first trailer. Such a train is not only 
complex and expensive but will behave poorly on the road and especially in 
sharp curves. 
SUMMARY OF THE INVENTION 
The general aim of the present invention is to provide an improved highway 
train of the kind defined in the introductory paragraph in which the 
various drawbacks of the prior art trains referred to hereinbefore are 
eliminated. More specifically it is an object of the invention to provide 
a highway train which is capable of following an almost ideal path without 
taking short cuts when being driven through sharp curves and this with a 
minimum of tire wear and a maximum of lateral stability, and the wheeled 
vehicles of which may easily be detached from the load carriers proper and 
thus intensively utilized for alternatingly transporting several sets of 
load carriers. 
According to the invention this aim is basically attained by a particular 
novel design of the auxiliary vehicle or vehicles used for interconnecting 
one load carrier to the next and by providing improved cooperation between 
each such auxiliary vehicle and the load carrier next ahead of it in the 
train. 
Further objects and features of the invention will become apparent from the 
following description of an embodiment thereof and from the accompanying 
drawings illustrating the same and to which the description refers.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In FIG. 1 there is shown a highway train drawn by a wheeled and steerable, 
motor-driven tractive vehicle 1, the front portion of which supports a 
driver's compartment 1' and the rear portion of which supports a pivot 
device 2 of the kind well known per se permitting pivotal movement about a 
vertical axis and commonly known as a "fifth wheel" usually comprising a 
turning plate which is tiltable about a transverse axis and has an inlet 
slot and a locking device for a so called king pin mounted on the lower 
side of the forward end portion of a semitrailer. However, other variants 
of known or conceivable pivot devices may be used if desired. 
Further, the highway train shown in FIG. 1 comprises two load carriers 3', 
3" which are here represented by elongate containers for the protected 
transportation of piece goods, but which also could be formed as 
load-carrying platforms, as liquid transport tanks or the like. Important 
is that each load carrier 3 is rigid and self-supporting and has a forward 
end portion 3A which is designed and adapted to be releasably connected to 
and supported by the pivot device 2 of the tractive vehicle 1, and a 
rearward end portion 3B which is designed and adapted to be releasably 
connected to and supported by either an auxiliary vehicle or an end 
vehicle, as will more specifically appear in the following. 
In the example shown each load carrier 3 also has a depressed intermediate 
portion 3C which, when needed, may be used as cargo space and which is 
capable of supporting the load carrier when the latter is rested on the 
ground as in FIG. 2, e.g. for loading or unloading. In the vicinity of the 
rearward end portion 3B of the load carrier 3 the intermediate portion 3C 
is provided with a pair of small, usually unsprung, auxiliary wheels 4 
which permit moving of the load carrier shorter distances, such as during 
switching within a limited parking area by means of the tractive vehicle 1 
in the manner shown in FIG. 6, but which are not suited for highway 
transportation of the load carrier. In addition, the load carrier 3 is 
provided with a pair of protrusible supporting legs 5 which are adjustable 
in a pair of associated telescopic guides 5' arranged on the front wall of 
the intermediate portion 3C under the inner portion of the forward end 
portion 3A. 
In the highway train shown in FIG. 1 there is also included an auxiliary 
vehicle 6, which will be more closely described in the following with 
reference to FIGS. 7-11. The auxiliary vehicle 6 has a front portion 6A 
supported by a front wheel axle with wheels 7 and a rear portion 6B 
supported by a rear wheel axle with wheels 8. All the wheels 7 and 8 are 
suitable for highway driving and may, when needed, be doubled in order to 
enable the auxiliary vehicle to withstand high loads. The rearward portion 
6B of the auxiliary vehicle supports a pivot device 9, similar to the 
pivot device 2 of the tractive vehicle 1, for receiving the forward end 
portion 3A of any one of the load carriers 3. 
Finally, in the highway train shown in FIG. 1 there is included an end 
vehicle 10 supported by a single wheel axle with wheels 11 which likewise 
are suited for highway driving and which may also be doubled, when needed. 
The end vehicle 10, which brings up the rear of the train. is adapted to 
be releasably connected to and to support the rearward end portion 3B of 
any one of the load carriers 3. If it is desirable to divide the train, 
the end vehicle may be used for individual transportation of any one of 
the load carriers 3, the forward end portion of the load carrier then 
being connected to the tractive vehicle 1, all in the manner shown in FIG. 
3. 
It should be understood that in case of need the highway train of FIG. 1 
may be extended to comprise three or even more load carriers 3 connected 
in tandem. However in such case the number of auxiliary vehicles 6 must 
also be correspondingly increased, because the number of auxiliary 
vehicles must always correspond to the number of load carriers minus one. 
On the other hand, a single end vehicle 10 will still be sufficient for 
completing the train irrespective of the number of load carriers. 
For a rational utilization of transport equipment permitting the assembly 
of a highway train of the kind shown in FIG. 1 there is in reality a need 
for at least one tractive vehicle 1, at least one auxiliary vehicle 6, at 
least one end vehicle 10 and a plurality of load carriers 3, say at least 
four. The most suitable number of load carriers depends on many different 
factors, such as for example the time consumed for the loading and 
unloading of the goods to be transported thereon, the transport distances, 
the possibilities of picking up another load carrier at the same time as 
one is delivered at a station, and so on. Then, of course, all the load 
carriers must be so designed that they may be connected with their forward 
end portions either to the tractive vehicle or to the auxiliary vehicle 
and with their rearward end portions either to the end vehicle or to the 
auxiliary vehicle. On the other hand, evidently no identity between the 
load carriers is required as far as size and detailed design is concerned. 
Since it must be possible to connect the load carriers 3 to the various 
supporting vehicles 1, 6 and 10 both rapidly and conveniently when the 
load carriers are rested on the ground by means of their auxiliary wheels 
4 and supporting legs 5, the rear frame portion of the tractive vehicle 1 
as well as the frame structures of the auxiliary vehicle 6 and of the end 
vehicle 10 are vertically adjustable between an elevated position for 
normal driving, shown in FIG. 1, and a lowered position for 
interconnection and disconnection, shown in FIG. 2. The elevation and 
lowering suitably takes place by means of air-spring systems, as will be 
described in closer detail later on. 
As occasions can hardly be avoided when the tractive vehicle 1 without 
pulling a load carrier must be able to bring along either the end vehicle 
10 alone, as in FIG. 4, or both the end vehicle and the auxiliary vehicle 
6, as in FIG. 5, from one station to another, the equipment should also 
include at least two separate draw bars, a first one 12 and a second one 
13, which when needed may replace the load carriers 3 as will also be more 
closely described in the following. 
The design of the auxiliary vehicle 6 is shown in greater detail in FIGS. 
9-11. It comprises an elongate rectangular frame structure 20 supported by 
a front wheel axle 21 having the wheels 7 and by a rear wheel axle 22 
having the wheels 8, both of said wheel axles occupying generally fixed 
and predetermined positions longitudinally of the frame structure 20, 
which rests on the front wheel axle 21 through the intermediary of a pair 
of vertically swingable arms 23 acted upon by two associated air-spring 
devices 24 and on the rear wheel axle 22 through the intermediary of two 
similar arms 25 with associated air-spring devices 26. In addition to 
providing normal vehicle suspension the air-spring devices 24 and 26 
permit lowering and re-elevation of the frame structure, as appears from 
FIGS. 10 and 11. 
The portion of the frame structure 20 located above the rear wheel axle 22 
supports the previously mentioned pivot device 9. A further pivot device 
27, which is reversed in relation to the pivot device 9 and which does not 
necessarily need to be identical to the latter, is supported by the frame 
structure 20 above the front wheel axle 21 in order to receive the 
rearward end portion 3B of a load carrier 3 in such manner that an angular 
displacement between this load carrier and the auxiliary vehicle 6 in both 
directions in the horizontal plane is made possible. An example of such 
angular displacement is illustrated in FIG. 8. The angular displacement 
between the load carrier running next ahead and the auxiliary vehicle is 
limited by a spring device 28 which is mounted at the forward end of the 
frame structure 20 and which, when the angular displacement reaches a 
predetermined magnitude, with one at a time of its two free ends comes to 
abut a vertical rear wall portion 29 on the load carrier 3 (FIGS. 7 and 8) 
and by doing so will exert a progressively increasing counter-moment, when 
the angular displacement is increased. 
The wheels 7 on the front wheel axle 21 of the auxiliary vehicle 6 are 
fixed, i.e. cannot be turned for steering, whereas the wheels 8 on the 
rear wheel axle 22 in a manner known per se can be turned about generally 
vertical king pins 30 and are mutually interconnected by a tie rod 31. The 
wheels 8 are steered in response to the angular displacement .alpha. (FIG. 
8) occurring between the auxiliary vehicle and the load carrier next ahead 
when the train is driven into and through a curve and this in such manner 
that the angular displacement .alpha. is eliminated during the continued 
forward movement of the train. Accordingly, the auxiliary vehicle will 
always seek a position in a straight line with the load carrier next 
ahead. Preferably the steering of the wheels 8 is arranged in such manner 
that the angle .beta. of lateral deflection of said wheels will be about 
2.5-3.0 times greater than the angle .alpha., which has been found to 
render the highway train an optimum ability to make its way even through 
sharp curves within a minimum of road lane. 
In reality this steering of the wheels 8 should preferably be effected by 
means of a hydraulic force transmission system, which, however, has not 
been shown because the operation thereof may be difficult to understand. 
Instead in FIG. 9 there is diagrammatically illustrated a purely 
mechanical steering transmission operating in the desired manner but less 
suitable for practical demands. This latter transmission comprises a loop 
33 of cable or chain running over pulleys 32. The loop is by means of a 
first coupling member 34 permanently connected to a center point on the 
tie rod 31 and has a second coupling member 35 adapted to be releasably 
connected to an attachment 36 on the lower side of the rearward end 
portion 3B of the load carrier next ahead, which attachment is situated at 
such radial distance from the center of the pivot device 27 that the 
desired transmission ratio is obtained. 
It should be readily understood that the fact that the auxiliary vehicle 6 
is pivotally connected to the load carrier 3 next ahead by means of the 
pivot device 27 and, in addition, has rear wheels 8 which are steerable in 
the manner just indicated will assure a capability of the auxiliary 
vehicle to follow the load carrier, and hence indirectly also the tractive 
vehicle 1, in a unique manner which is very favorable from several 
different points of view. Thus the tire wear is kept at a minimum and an 
optimum lateral stability of the highway train in taking curves is 
assured. At the same time the auxiliary vehicle 6 in taking a curve is 
caused to follow a path which considerably reduces the tendency of the 
successive load carrier to take a short cut. In other words, the highway 
train is rendered an improved capability to turn e.g. at street corners 
without therefore requiring a lane of great width. 
The end vehicle 10 is shown in FIGS. 12-14 and comprises a relatively 
short, rectangular frame structure 40 supported by a wheel axle 41 having 
the wheels 11, which are fixed, i.e. cannot be turned. The frame structure 
40 rests on the wheel axle 41 through the intermediary of a pair of 
vertically swingable arms 42 acted upon by two associated air-spring 
devices 43, which in addition to normal vehicle suspension permit lowering 
and re-elevation of the frame structure 40 as appears from FIGS. 13 and 
14. At its forward end the frame structure is provided with a centrally 
located supporting leg 44 which is protrusible from a guiding sleeve 45 
secured to the frame structure, as well as with a yoke 46 which is adapted 
to abut the vertical wall portion 29 of the load carrier 3 running next 
ahead which has been previously mentioned in connection with the spring 
device 28 of the auxiliary vehicle 6. 
On its upper side the frame structure 40 of the end vehicle 10 supports a 
coupling device 47 which somewhat resembles the pivot device 27 on the 
front portion 6A of the auxiliary vehicle 6 and which permits connection 
of the end vehicle to the rearward end portion of the load carrier running 
next ahead. It should be noted, however, that there will be no pivotal 
movement between the end vehicle 10 and this load carrier 3 next ahead, 
because the yoke 46 will prevent such movement by abutting the wall 
portion 29. 
The air-spring devices 24 and 26 on the auxiliary vehicle 6 as well as the 
air-spring devices 43 on the end vehicle 10 are supplied with compressed 
air from the tractive vehicle 1 through conduits and conduit couplings, 
not shown. Suitably this is effected through separate conduits to each 
pair of air-spring devices so that the elevating operation of the various 
pairs may be individually remote-controlled by means of a valve 
arrangement, not shown, on the tractive vehicle 1. Also the tractive 
vehicle itself has similar air-spring devices at least for elevating and 
lowering its rear frame portion in the manner previously indicated. 
From FIGS. 15 and 16 it more closely appears how the load carriers can be 
replaced by the draw bars 12 and 13. The rearward end portion of the draw 
bar 12 is first rigidly connected to the end vehicle 10 by engaging the 
coupling device 47 in the same manner as does any one of the load carriers 
3 and by being locked to the end vehicle frame by means of a suitable 
locking device 12', whereupon the forward end of the draw bar 12 may be 
pivotally connected either to the pivot device 2 of the tractive vehicle 1 
(FIG. 16) or to the rear pivot device 9 on an auxiliary vehicle 6 (FIG. 
15). The draw bar 13 is in its turn connected as a link between the pivot 
device 2 of the tractive vehicle 1, or the corresponding pivot device 9 on 
an auxiliary vehicle running next ahead, if there are more than one such 
vehicle, and the forward pivot device 27 on the drawn auxiliary vehicle 
and has a rearwardly directed extension 13' with an attachment 14, 
corresponding to the attachment 36 on each load carrier 3, from which a 
force for steering the rear wheels 8 of the auxiliary vehicle 6 is derived 
in the manner previously indicated. 
It is to be noted that, when the auxiliary vehicle is towed by means of the 
draw bar 13, the spring device 28 of the auxiliary vehicle 6 co-operates 
with a crossbeam 48 mounted at the rear end of the tractive vehicle 1. If 
there is a need for towing several auxiliary vehicles, one behind the 
other, in consequence with the aforesaid each of them must be provided 
with a corresponding crossbeam at its rear end. 
As the drawings are only intended to illustrate the basic inventive 
concepts, many modifications of details of the various components are not 
only conceivable but also in many cases necessary in order to meet 
practical demands. As an example of such modifications it may be mentioned 
that double wheel axles may be required in front as well as behind in each 
auxiliary vehicle 6 as also in the end vehicle 10 and at least at the rear 
of the tractive vehicle 1.