Trailer for transporting and launching floating box caissons

A trailer for transporting, launching and retrieving floating box caissons includes a conventional road chassis, a tip-frame pivoted to the rear end of the road chassis and provided with a system for tipping the tip-frame from a normal horizontal position, and a sub-frame slidably mounted in the tip-frame and provided with a system for causing longitudinal translation of the sub-frame in relation to the tip-frame. A hauling carriage is guided for movement within the sliding sub-frame. A system is provided for moving the hauling carriage in translation within the sliding sub-frame. A lock is mounted on the hauling carriage for rigidly coupling a floating box-caisson to the carriage.

BACKGROUND AND SUMMARY OF THE INVENTION 
The present invention relates to a trailer designed for performing the 
following duties: transporting on ordinary or bad roads a floating box 
caisson, smoothly and completely launching the floating box-caisson, even 
in a strong-current water-course, and retrieving the caisson floating on 
water for re-installing the same on the trailer for transporting the 
caisson to another site, this last-mentioned operation being also 
performed when the caisson is floating in a strong-current water-course. 
All these operations are performed by using only equipment provided on the 
trailer. 
A trailer according to this invention has a conventional road chassis of 
relatively simple design, and is characterized in that it comprises a 
tip-frame hingedly mounted to the rear edge of the road chassis and 
provided with means for causing the tip-frame to be tipped from its normal 
horizontal position to a more or less inclined position. A sub-frame is 
slidably mounted in the tip-frame and is provided with means for causing 
its longitudinal movements of translation in relation to the tip-frame. A 
hauling carriage is provided with means for guiding the same for movement 
within the sliding sub-frame. A system is provided for causing the 
carriage to move in the sliding sub-frame. A lock is mounted on the 
hauling carriage for interlocking the caisson and carriage assembly. 
According to a specific feature characterizing this invention the means for 
tipping the tip-frame from its normal horizontal position comprise 
fluidactuated cylinders interposed between the road chassis and the 
tip-frame. 
According to a further feature characterizing this invention, the means for 
moving the sliding sub-frame in translation with respect to the tip-frame 
comprise an endless chain system driven from a hydraulic motor. According 
to this invention, the same endless chain system may be used for 
controlling the longitudinal movements of translation of the hauling 
carriage.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIG. 1, it will be seen that the trailer according to this 
invention, which is of the type adapted to be towed by a tractor or other 
vehicle, comprises essentially the following component elements: 
(a) a conventional road chassis 10 of relatively simple structure, provided 
with a front saddle and a rear axle, and constituting the road section of 
the trailer; 
(b) a tip-frame 12 hingedly mounted by means of horizontal transverse pivot 
means 28 to the rear end of the road chassis 10 and adapted to be tipped 
to an angle of about 45.degree. to the horizontal when fluid-actuated 
cylinders 14 interposed between the road chassis 10 and the tip-frame 12 
are operated; 
(c) a sliding sub-frame 16 mounted within the tip-frame 12 and adapted to 
be moved for translation in relation to the tip-frame along a path of 
about five meters. This movement of translation, in the embodiment 
illustrated, is obtained by means of an endless system 18 driven from a 
hydraulic motor (not shown); 
(d) a hauling carriage 20 is guided by means of rollers 22 for movement 
along rails (not shown) disposed within the sliding sub-frame 16. In the 
example illustrated, this movement is obtained by means of the endless 
chain system 18 controlling the movements of the sliding sub-frame 16. 
Furthermore, the hauling carriage 20 is provided with means 24 for locking 
the box-caisson 26 to the trailer. These hand-controlled means 24 may for 
example be of the conventional hook and bolt type. The carriage is 
released manually at the end of the launching operation when it is desired 
to free the floating box caisson 26 from the trailer. In the transport 
position, caisson 26 is locked to the hauling carriage 20. 
Now the various steps required for launching a floating box caisson carried 
by the trailer of this invention will be described with reference to FIGS. 
2 to 6 of the drawing. 
The trailer according to this invention (FIG. 2) towed by a conventional 
tractor or other vehicle is driven to the launching site, and the tractor 
and trailer assembly is backed as close as possible to the water surface 
as a function of the type or nature of the bank. If the bank has a very 
moderate inclination, or if the ground is slightly boggy, the trailer may 
be backed until its rear axle is more or less immersed in the water. 
Then the sliding sub-frame 16 supporting the caisson 26 is moved in 
translation (FIG. 3) by actuating the endless chain system 18 driven from 
a hydraulic motor (not shown), until sub-frame 16 is stopped by a 
mechanical stop or lock 30, the position of which is determined to bring 
the centre of gravity of the movable assembly as close as possible to the 
tip point. 
The next step (FIG. 4) consists in tipping the tip-frame 12 about the 
horizontal transverse hinge axis 28 at the rear end of the trailer. This 
tip movement is obtained by actuating hydraulic cylinders 14. The 
inclination assumed by the tip-frame in relation to the horizontal is 
adjusted as a function of the type of banks to be dealt with. Preferably 
the rear end of the sliding sub-frame 16 should be at a height of about 20 
centimeters above the water surface. 
By properly actuating the endless chain system 18 the hauling carriage 20 
(FIG. 5) is lowered and consequently the box caisson 26 rigid therewith is 
also lowered and guided within the sliding sub-frame 16 by means of the 
above-mentioned roller and rail system (FIG. 1), thus holding the 
box-caisson in the transverse direction during its downward movement. When 
the end of the box caisson 26 engages the water surface, the buoyancy 
acting on this end tends to separate the caisson 26 from the sliding 
sub-frame 16, since the caisson is attached only by its front end to the 
hauling carriage 20. 
When the hauling carriage 20 engages a mechanical stop element provided at 
the rear end of the sliding sub-frame 16, the box caisson 26 is definitely 
afloat (FIG. 6) but still connected to the trailer through the lock means 
24 provided on the carriage 20. This connection, notably in case of strong 
current, is suitable to permit the adaptation of an anchorage or 
propulsion means that shall be required when the caisson will have to be 
handled or retained on the water surface. 
After completing the anchorage or propulsion operations required for the 
box caisson concerned, the latter can eventually be released from the 
trailer, the lock means 24 being controlled from the top of the caisson. 
Now the successive operations necessary for re-loading the trailer with the 
floating box caisson 26 will be described. In fact, these operations are 
substantially the same as those described hereinabove in connection with 
the launching of the box caisson, but are performed in the reverse order. 
The empty trailer is brought close to the shore, substantially as shown in 
FIG. 6, i.e. with the sliding sub-frame 16 in its rearmost position, the 
tip-frame 12 raised and the hauling carriage 20 close to the water level. 
By autonomous or external propulsion, the floating box caisson 26 is 
brought as close as possible to the hauling carriage 20. The lock means 24 
provided on carriage 20 are actuated to lock automatically the adjacent 
end of the floating box caisson 26 to the rear end of the hauling carriage 
20, this locking action being obtained even in case of very approximate 
approach of the two elements to be coupled. 
Then the propulsion means of the floating box caisson may be disconnected 
so that the stress resulting from any current in the water stream is 
transmitted to the trailer structure. Under these conditions, the 
re-loading of the box caisson 26 on the trailer may begin. 
By actuating the endless chain system 18, the hauling carriage 20 and 
therefore the box caisson 26 carried thereby are moved up the sliding 
subframe 16 (FIG. 5) until the carriage engages a stop or lock 31 provided 
for this purpose at the upper or front end of the sub-frame 16. 
Subsequently, the tip-frame 12 is tilted back to the horizontal by 
actuating first the cylinders 14 (FIG. 4) and then the endless chain 
system 18, in order to cause the forward translation of the sliding 
sub-frame 16 until the component elements resume their original transport 
position illustrated in FIG. 2. 
From the above description it is clear that all the operations involved are 
performed by using only equipment provided on the trailer according to the 
invention. The caisson launching and re-loading operations may be 
performed irrespective of the type of bank or shore from which they are to 
take place, whether a smooth, moderately-inclined beach or a pier lying 
six feet above the water-level are concerned. 
Of course, this invention should not be construed as being strictly limited 
by the specific embodiment described and illustrated herein, since it also 
includes all modifications and changes brought thereto within the scope of 
the invention. Thus, notably, the means contemplated for launching 
floating box caissons may also constitute a fixed equipment installed 
adjacent a water surface of any type. What is claimed as new is: