Tensioning band fastening device

A device for fastening the free end of a tensioning band for securing loads to a loading platform on a truck by a tensioning band and a tensioning device. The fastening device comprises a sleeve having a hook which engages a D ring attached to the free end of the band. The hook is pivotably and resiliently attached to the sleeve and is remotely operated by an operating device. When the tensioning force in the band exceeds a predetermined value, which is determined by the spring, a switch is actuated by the spring and making a monitoring lamp positioned in the truck cabin to go out. The operating device can be a stay extending transversally from the fastening device and beneath the platform to the corresponding tensioning device, or a pneumatic, hydraulic or an electromechanic device operated from the corresponding tensioning device and/or from the truck cabin.

The present invention relates to a device for securing loads to a loading 
platform on a truck by means of a tensioning band and a tensioning device 
and more particularly it relates to an improved device for fastening the 
free end of the tensioning band to the platform or the frame. 
A device of this kind, a tensioning device, consists of a drum holding 
means disposed at one longitudinal side of a truck platform, a latchable 
winding drum, a tensioning band which may be wound around the drum and 
means for fastening the free end of the tensioning band to the other 
longitudinal side of the platform opposite the tensioning device. 
The present fastening means generally consists of a hook attached to the 
loading platform and a so-called D ring which is attached to the end of 
the tensioning band. Alternatively, a sleeve may be provided in the 
loading platform into which sleeve the said D ring is introduced and in 
which it is locked by means of a pin. 
The fastening means is used in such a way that the tensioning band is 
pulled out from its storage position on the drum and is thrown over the 
load so as to fall down at the outer side of the loading platform. The 
truck driver then walks around the platform and secures the D ring in the 
corresponding fastening means and returns to the tensioning device in 
order to impart to the band a certain preload by means of the winding 
drum. The latching means prevents the bands from going slack. A suitable 
tension in the tensioning bands is 1350 to 1800 pounds force. 
Thereafter the driver passes around the platform and detaches the D ring 
from its fastening means and returns to the tensioning device in order to 
wind the band onto the winding drum. 
This makes it necessary for the truck driver to pass back and forth around 
the truck several times and there is consequently a need for reducing the 
number of movements. 
However, when piece goods are transported, the load will as a rule settle 
slightly, for instance because of shaking or due to swaying movements. In 
that case, one or more of the tensioning bands may go slack and will 
consequently lose its tightening action. It is consequently desirable to 
indicate whether the band is under tension. 
The above problem is solved according to the present invention by providing 
a novel fastening means whose locking mechanism may be remotely controlled 
and which is provided with a device indicating band tension.

The fastening device 1 shown in FIG. 1 is secured to a loading platform 2 
immediately inside the side beam 3. The fastening device comprises a 
sleeve 4 which is welded to the side beam 3 and a hook 5 is journalled on 
a shaft 6 and which ends in a lever 7 and a handle 8. The shaft 6 is 
secured to a forklike bracket 9, which is attached via a spring device 10 
to the sleeve 4. The spring device 10 comprises the fork bracket 9, which 
is secured to a bolt 11 by means of a locking screw 12 or a locking pin. 
The bolt is moved downwardly through an opening 13 in the casing 14 of the 
spring device and through a centrally located opening 15 in a cylindrical 
"urelast" spring 16. The spring 16 is in turn surrounded by a spacing 
sleeve 17 of metal through the end wall 18 of which said bolt extends. The 
spring 16 is consequently clamped between the end wall 18 of the spacing 
sleeve and the end wall 19 of the casing 14 with a certain predetermined 
bias. The said bias may be adjusted by means of the bolt 11. At the lower 
end of the bolt there is provided a micro switch 20 with conduits which is 
in its actuated position. Furthermore, a stay 22 is secured to the lever 
7, said stay extending beneath the platform 2 to a tensioning device (not 
shown) located at the opposite side. The tensioning band 24 ends in a so 
called D ring 25 having an aperture 26 (see FIG. 6). 
The fastening device functions in the following manner. The initial 
position is shown in FIG. 1. The D ring is introduced into the sleeve 4 
into abutment with the hook 5. When the D ring is pressed further down, 
the hook 5 is rotated around its shaft 6. The rotational movement is 
counteracted by the weights of the lever 7 and the handle 8. Space 34 in 
the hook 5 is thereby opened, whereupon the aperture 26 of the D ring can 
be introduced into the space. The hook 5 may then be snapped back into its 
initial position with the D ring fastened between the hook 5 and the 
lateral wall of the sleeve 4. If tension is exerted in the band 24, the D 
ring will exert an upwardly directed force on the hook, said hook tending 
to rotate counterclockwise into the groove 35 of the sleeve 4. As a result 
of this, the D ring 25 is pressed against the lateral wall of the sleeve 
4, the D ring being retained still more securely. 
The tension force exerted by the tensioning band 24 and the D ring 25 onto 
the hook 5 is transmitted to the spring means 10 via the shaft 6, the fork 
bracket 9, the bolt 11 and the spacing sleeve 17. The spring 16 has been 
given a bias by means of the bolt 11 said bias corresponding for instance 
to a tensioning force of 1350 pounds in the band. If the tensioning force 
in the band is below this value the fork bracket is in its initial 
position abutting the end wall 19 of the spring casing, the micro switch 
20 being activated. If the tension force in the tensioning band increases, 
the fork bracket and the bolt will become displaced slightly upwards under 
simultaneous compression of the spring 16. During that movement the fork 
bracket is guided in separate guiding means 27. When this movement is 
performed the micro switch is deactivated. If the tension force in the 
tensioning band is increased still more, the spring 16 will be compressed 
to such a degree that the spacing sleeve 11 comes into contact with the 
end wall 19 of the spring casing 14, which takes place when there is a 
tension force of for instance 1800 pounds in the tensioning band. When the 
tension force in the tensioning band increases still further, no 
additional displacements will take place. 
The micro switch 20 is connected via the conduits 21 to a monitoring lamp 
which may be located for instance on the dashboard in the truck cabin, 
said lamp being alight when the micro switch is activated. The lamp goes 
out when the tensioning force in the band is in excess of 6 kN. 
When the load is to be unloaded the latching means of the tensioning device 
is first loosened. Thereupon the D ring is loosened by pulling the stay 22 
extending beneath the platform from the tensioning device to the lever 7. 
This removes the drawback of having the driver pass back and forth around 
the truck during the unloading operation. The D ring may also be loosened 
by means of the handle 8. 
The sleeve 4 is provided at its bottom with drainage openings 28 for 
draining rain water. When the fastening device is not in use the sleeve 
should preferably be covered by a plastic lid 29. 
A person skilled in the art will realize that different types of 
compression springs may be used instead of the "urelast" spring 16. Thus, 
a cylinder spring of spring steel or other resiliently compressible 
materials may be used. Furthermore, the micro switch 20 may be replaced by 
other conventional switch means. 
FIG. 3 shows a second embodiment of the fastening device according to the 
present invention. The construction is largely similar to the one 
described above but differs therefrom inter alia with respect to the 
remote control of the hook 5 and the location of the micro switch. The 
lever 7 has been replaced by a shorter lever 30 to which the plunger 31 of 
the pneumatic cylinder 32 is attached. The cylinder casing 33 is secured 
to the sleeve 4 and the spring casing 14. When activating the pneumatic 
cylinder 32, the plunger 31 is pressed out of the cylinder in order to 
rotate the hook 5 clockwise, the D ring being loosened from the hook. The 
pneumatic cylinder is provided with an interior return spring (not shown) 
which provides that the hook 5 is spring biased against its locking 
position. 
The operating power for the pneumatic cylinder is taken from the pneumatic 
system which exists in most trucks. The fastening means may be opened 
either from a central operating device for all fastening means provided in 
the driver's cabin or in another suitable place, or separately by control 
means provided at the corresponding tensioning device. The pneumatic 
cylinder may also be replaced by a hydraulic cylinder or an 
electromagnetic device, if desired. 
Furthermore, the micro switch 50 is located in such a way that it will be 
activated by the fork means 9, as is best shown in FIG. 4. In this 
embodiment the "urelast" spring 16 is only biassed by 112 pounds. The 
spacing sleeve 17 is slightly shorter in order to permit a larger movement 
in the fork device. The spacing sleeve 17 reaches the end wall 19 when 
there is a tensioning force of about 1350 pounds in the band. When the 
tensioning band is tightened the fork bracket 9 is displaced upwardly and 
presses the operating arm 36 of the micro switch 50 to the left as viewed 
in FIG. 4 when a predetermined tensioning force is applied. In that 
connection the corresponding monitoring lamp goes out in order to indicate 
that the tensioning band is under tension. The said predetermined 
tensioning force at which the micro switch is actuated is dependent on the 
location of the micro switch in the vertical sense and the location of the 
micro switch may be changed in dependence on the load to be transported. 
Furthermore, this second embodiment is provided with a guiding plate 37 in 
order to guide the D ring into cooperation with the hook at the 
introduction of the D ring into the sleeve. 
This sleeve 4 may also be provided with guiding plates 38, 39 for lateral 
guiding of the D ring, as is shown in FIGS. 5 and 6. In the said third 
embodiment the sleeve 40 is made more narrow. Furthermore, the hook 41 is 
modified and is provided with an oblique upper cam surface 42, which 
causes the D ring to be guided towards the opening 43 of the hook when the 
hook is rotated through a slot 41 in a side wall 46 of sleeve 40. 
Furthermore, the side wall 44 of the sleeve facing the hook has an opening 
with upper edge 45 with which the hook cooperates in such a way that when 
the tensioning band pulls the hook and the spring means upwardly, a notch 
48 in the hook engages upper edge 45 and the side wall 44 of the sleeve. 
This prevents the hook from getting loose. 
The switch means may be connected in several different ways in order to 
indicate that the corresponding band is under correct tension. Thus, the 
switching means of a plurality of fastening devices may be connected in 
series and be connected to one common monitoring lamp on the dashboard of 
the truck, which is dark when all tensioning bands are under the correct 
tension and which will be lit as soon as one or more of the tensioning 
bands become loosened. Preferably, there is also provided an individual 
monitoring lamp at each tensioning device so that the truck driver may 
decide from the tensioning device when the band has been tensioned 
sufficiently. 
Fastening means according to the present invention provides inter alia the 
advantages mentioned by way of introduction. Furthermore, a certain 
resiliency is obtained in the attachment of the tensioning band, which is 
advantageous when the truck is driven along a rutty road since in that 
case the load is not secured to the loading platform in such a way that it 
cannot move at all. In order to provide the securing means somewhat inside 
the side member an additional advantage is obtained, viz. that the load is 
supported laterally from the platform surface. 
The above embodiment has only been described for the purpose of 
illustrating the invention without limiting it in any manner except by the 
following claims.