Seal providing a tight joint between two sections of a conveyor belt and a coupling device fitted with said seal

A seal fitted between two sections of a conveyor belt is constituted by a member of resilient material having a generally U-shaped cross-section which can be placed astride the end portion of a belt section to be assembled, beneath the belt-fasteners of the corresponding row of a coupling device. The web of the seal has a series of transverse cut-out portions so arranged as to receive the end portion of the hinge-knuckle of one of the belt-fasteners of the oppositely-facing row and to delimit a corresponding number of narrow strips which are intended to be applied against the coupling-pin. Each strip has the shape of a loop forming a projection opposite to the side which is to be applied on the coupling-pin. Thus the loop can be compressed or stretched-out to a greater or lesser extent according to the thickness of the conveyor belt.

BACKGROUND OF THE INVENTION 
The present invention relates to the devices employed for coupling two 
sections of a conveyor belt. The invention is more particularly concerned 
with the belt-coupling devices constituted by two rows of fasteners having 
a generally U-shaped cross-section. These fasteners are intended to be 
fixed astride the ends of the two belt sections in order to be 
subsequently united by means of a hinge-pin inserted in the interengaged 
hinge-knuckles formed by said fasteners. 
The basic design of this structure is such that a more or less substantial 
clearance exists between the hinge-knuckles of the two rows of 
belt-fasteners as well as between the hinge-knuckles of a predetermined 
row and the edge of the opposite end of the conveyor belt. Under these 
conditions, when a belt of this type is employed for transporting bulk 
materials which include fines such as coal, for example, these fines can 
pass through the interstices which thus exist in the coupling device. This 
in fact constitutes a disadvantage since the fines which pass through are 
liable to penetrate into the journal-bearings and roller-bearings of the 
guide rollers and drive pulleys of the conveyor belt. This is liable to 
result in risks of seizure and damage to the installation. 
In order to overcome these disadvantages, it has already been proposed to 
add means for sealing the aforesaid belt-coupling devices as tightly as 
possible. Thus British patent No. 634,028 describes a coupling device in 
which provision is made for the addition of a bead of compressible 
material between the edge of each end of a conveyor belt and the hinge-pin 
which is engaged within the hinge-knuckles of the two rows of 
belt-fasteners. By reason of their compressibility, said beads accordingly 
assume the same shape as the opposite portions of the hinge-pin. However, 
by reason of the very fact that they are simply fitted within the space 
located between the coupling pin and the edge of one end of the conveyor 
belt, said beads are not really fixed in position and are therefore liable 
to move. Furthermore, as a result of the fact that they are not fixed in 
position, these beads may become twisted at the time of pivotal motion of 
the corresponding coupling device and may consequently be damaged in a 
very short time. 
Moreover, the thickness of a bead of this type must be determined according 
to the thickness of the corresponding conveyor belt. It is therefore not 
possible to employ the same type of bead for very different belt 
thicknesses. 
For the reasons given above, the invention is directed to a seal which is 
designed with a view to overcoming the disadvantages set forth in the 
foregoing and also to ensuring that the seal can be mounted with great 
ease. 
SUMMARY OF THE INVENTION 
The seal in accordance with the invention is constituted by a member of 
resilient material having a generally U-shaped cross-section which can be 
placed astride the end portion of a belt section to be assembled, beneath 
the fasteners of the corresponding row of a coupling device. Said seal is 
distinguished by the fact that: 
the central web of said seal has a series of transverse cut-out portions so 
arranged as to receive the end portion of the hinge-knuckle of one of the 
belt-fasteners of the oppositely-facing row and to delimit a corresponding 
number of narrow strips which are intended to be applied against the 
coupling-pin on the side diametrically opposite to that of the end portion 
of the hinge-knuckle of one of the fasteners of the corresponding row, 
each narrow strip thus provided has the shape of a loop forming a 
projection opposite to the side which is to be applied on the coupling-pin 
and said loop can be compressed or stretched-out to a greater or lesser 
extent according to the thickness of the corresponding conveyor belt. 
Thus the seal under consideration is perfectly immobilized after the 
fasteners of the corresponding coupling device have been fixed in position 
since the staples for fixing said belt-fasteners are caused to pass 
through both lateral branches of said seal. Moreover, this seal can be 
employed on conveyor belts having varying thicknesses. In fact, the loop 
formed in the strips which constitute the central portion or web of the 
seal enables said strips to expand or contract according to whether the 
conveyor belt is of substantial thickness or on the contrary of small 
thickness. Furthermore, the presence of the cut-out portions between said 
strips endows the web of the seal with considerable flexibility and 
precisely allows expansion or contraction of the web according to the 
greater or lesser thickness of the corresponding conveyor belt. 
The present invention is also concerned with the coupling devices of the 
type recalled in the foregoing which are provided with two seals as 
defined earlier.

DETAILED DESCRIPTION OF THE INVENTION 
As already mentioned, the seal shown in FIG. 1 is intended to be added to a 
device for coupling the ends of two sections 1a and 1b of a conveyor belt. 
This device is of the type comprising two rows of metal belt-fasteners 2a, 
2b having the general shape of a U which are mounted astride the ends of 
both belt sections. These fasteners form hinge-knuckles 3a and 3b 
respectively which are therefore oriented in opposite directions. Said 
hinge-knuckles are relatively displaced in order to be located in 
interjacent relation and thus to constitute a virtual hinge within which 
is engaged a coupling-pin 4 constituted by a length of wire cable. The two 
rows of belt-fasteners are attached by means of metal staples 5, the 
pointed ends of which are clinched after having passed successively 
through a first arm of one of the belt-fasteners 2a or 2b, the 
corresponding section 1a or 1b of the conveyor belt, and the opposite arm 
of the same belt-fastener. 
The seal shown in FIG. 1 and designated by the general reference 6 has a 
generally U-shaped cross-section. Said seal can thus be placed astride the 
end portion of one of the sections of the conveyor belt, beneath the 
fasteners of the corresponding row. The two lateral flanges 7 and 8 of the 
seal accordingly form two bands which are placed respectively against each 
face of the corresponding section of the conveyor belt. Thus at the time 
of insertion of the fastening staples 5, these latter pass through both 
flanges of the seal. 
The central portion or web 9 of said seal has a series of transverse 
cut-out portions 10 which delimit a corresponding number of narrow strips 
11. Each strip in fact has the shape of a loop forming a projection 
opposite to the side which is intended to be applied against the 
coupling-pin 4. 
In proximity to the point of junction with the web 9 of the seal, each 
lateral flange 7 and 8 of this latter is adapted to carry a series of 
projecting teeth 12. Each tooth is located very precisely in vertically 
opposite relation to one of the cut-out portions 10 of the web 9. It is 
worthy of note that the face of the teeth 12 which is directed towards the 
coupling-pin 4 has a concave profile 13. 
The seal thus formed is manufactured by molding of elastic material such as 
natural or synthetic rubber, for example. Said seal thus has a very high 
degree of flexibility which is clearly increased in the central portion or 
web 9 by the presence of the considerable number of transverse cut-out 
portions 10. In consequence, the intermediate strips 11 have very great 
flexibility and are thus very readily deformable. 
The projecting teeth 12 of said seal are intended to be placed within 
spaces 14 located between two successive hinge-knuckles 3a or 3b of the 
corresponding row of belt-fasteners. In consequence, the cut-out portions 
10 of the seal considered are in turn placed between two successive 
hinge-knuckles of said row of fasteners. Thus, at the time of assembly of 
the two rows of fasteners by means of the coupling-pin 4, the cut-out 
portions 10 and the strips 11 of the two seals 6a and 6b fitted in both 
rows are also in relatively displaced relation as in the case of the 
hinge-knuckles 3a and 3b of said fasteners. The end portions of the 
hinge-knuckles of the oppositely-facing row of fasteners are consequently 
placed within the cut-out portions 10 of a seal 6a or 6b considered and 
come into contact with the curved faces 13 of the projecting teeth 12 of 
said seal. 
As for the seal strips 11, they are located opposite to the hinge-knuckles 
3a or 3b of the corresponding row of belt-fasteners. In consequence, said 
strips are directly applied against the coupling-pin 4 on the side 
diametrically opposite to that of the end portion of the hinge-knuckle of 
one of the belt-fasteners of the corresponding row. Thus, as is clearly 
apparent from FIGS. 4a and 4b, the pin 4 is completely enclosed between 
the hinge-knuckle 3a or 3b of the belt-fasteners of one of the rows and 
one of the strips 11 of the seal belonging to the same row of fasteners 
(as shown in FIGS. 4a and 4b). This makes it possible to obtain perfect 
leak-tightness, all the more so since the projecting teeth 11 are engaged 
within the spaces between two successive hinge-knuckles and since, in 
addition, the end portions of the hinge-knuckles 3a or 3b of each row are 
engaged within the cut-out portions 10 of the web 9 of the seal belonging 
to the opposite row of belt-fasteners. 
However, the main advantage of the seal in accordance with the invention 
lies in the fact that this latter can be employed on conveyor-belt 
sections of varying thickness. This arises from the fact that the strips 
11 each have the shape of a loop and can consequently be caused to expand 
to a greater or lesser extent according to requirements or on the contrary 
to contract. As has already been mentioned, said strips have a high degree 
of flexibility by virtue of the numerous cut-out portions 10 provided in 
the web 9 of the seal. 
Moreover, FIGS. 4a and 4b illustrate the use of the seal in accordance with 
the invention on conveyor belts having different thicknesses E1 and E2. As 
can be observed, when seals of this type are employed on conveyor belts of 
relatively substantial thickness, this simply has the effect of elongating 
the loop formed by the strips 11 (case of FIG. 4a). On the other hand, 
when seals of this type are employed with conveyor belts of smaller 
thickness, the loop formed by each strip 11 is consequently compressed to 
a greater or lesser extent in an accordion pleat (as in the case of FIG. 
4b). There is thus considerable latitude, with the result that a single 
type of seal can be employed on belts having very different thicknesses. 
This accordingly constitutes an essential advantage over the seals 
provided in the prior art on coupling devices of the type considered. 
The basic concept of the seal in accordance with the invention is such that 
it can be mounted beforehand within the belt-fasteners of one and the same 
row. The projecting teeth 12 of said seal are accordingly engaged between 
the spaces located between the hinge-knuckles of the row of fasteners 
considered. This is sufficient to ensure that the seals are held in 
position up to the moment when the corresponding row of fasteners is 
employed and fixed in position, the cross-section of the projecting teeth 
12 being so dimensioned as to ensure that the seal is jammed in position 
to a certain extent. 
In consequence, there are no additional operations to be performed in order 
to position the seals with which the two rows of belt-fasteners of the 
same coupling device are equipped. In fact, it is only necessary to adapt 
the two rows of fasteners on the ends of each of the two conveyor-belt 
sections to be assembled in order to ensure that the two corresponding 
seals are in turn suitably mounted and positioned, and that the end 
portions of the hinge-knuckles of the belt-fasteners of one of the rows 
consequently engage within the cut-out portions 10 of the web of the seal 
6 provided within the fasteners of the opposite row. 
In the example shown in the drawings, the seal in accordance with the 
invention is employed with belt-fasteners each constituted by two 
hinge-knuckles. However, said seal could just as readily be employed with 
fasteners provided in each case with a single hinge-knuckle or on the 
contrary with a greater number of hinge-knuckles. Moreover, the details of 
form of the seal in accordance with the invention may be modified 
according to the characteristics of the fasteners of the coupling device. 
As has already been indicated, the invention is also concerned with 
coupling devices having two rows of belt-fasteners of the type considered 
and two seals added to both rows. These devices can be employed for 
coupling the sections of a belt which serves to convey bulk materials such 
as coal, gravel, and so on.