Conveyor belts are known, used for transporting various materials or
various products, such as coal, ore, industrial or agricultural products. These conveyor
5 belts consist of belts made of a reinforced elastomer, or of a reinforced synthetic
material, of a suitable length and width, of which the ends must be connected
together, before mounting, or after mounting, on devices for supporting and driving
that comprise deflection rollers and idler rollers. Often these devices also comprise
members for tensioning, that have for purpose to.keep the conveyor belt taught.
10 Until now various means have been used to carry out this connection of
the ends of conveyor belts. At the outset, and still today, vulcanisation is used when
the belt is constituted of a reinforced elastomer that can be vulcanised. After
preparatory work intended to create in each end sorts of degrees that are respectively
complementary that apply to one another when said ends are brought close to one
15 another, the vulcanisation is carried out with the adding of heat and pressure such as
is well known. An alternative to vulcanisation is cold gluing.
Another known means of connecting consists in using staples with a
general U-shape, cut out from a metal sheet, said staples comprise upper plates and
lower plates connected by knuckles, with these staples being fastened in two series
20 astride on each one of the ends of the conveyor belt to be connected, in such a way
that the knuckles overhang and that those of one series can be nested between the
knuckles of the other series, with a connecting and articulating rod then being passed
inside the knuckles nested in such a way as to connect as such the two ends by
forming a sort of hinge. The known means used to fasten the staples onto the ends of
25 the conveyor belt consist of means for fastening with a stem such as clamps, rivets
and screws.
In a more recent past devices for linking have been proposed that make
use of flat connection elements made of reinforced elastomer or of reinforced
synthetic material, arranged respectively on one side and on the other side of the
30 ends of the conveyor belt and fastened onto said ends that are to be connected. An
example of such devices for linking is given by US patent no. 5 839 571, wherein the
armatures consist of crossed sets of cables. These devices comprise an upper plate
and a lower plate, as well as a central portion that connects the two plates. However,
col. 81. 12 to 17, the same patent considers limiting the device to two plates, an upper
35 plate and a lower plate.
2
By convention in all of the text of this application the term "upper"
applied to a part or to a portion of a part, shall mean located opposite rollers of the
device for supporting and driving the conveyor belt. The term "lower" applied to a
part or to a portion of a part shall mean located on the side of the conveyor belt that
5 is in contact with the rollers of the device for supporting and driving the conveyor
belt. Likewise, applied to devices for linking, the term "outer" will be used to
designate the space oriented opposite the rollers and the term "inner" will be used to
designate the space oriented on the side of the rollers. These notions are therefore
independent of the visual position of the conveyor belt, whether considering the
10 upper run of the conveyor belt or whether considering the lower run of the conveyor
belt in service.
Also by convention, the term "armature" shall apply to flat elements,
most often unique in each plate of the device for linking, but able for several to be
present, the term highly extendable characterising the property of extendability of
15 each element of the armature and the term inextensible ch_aracterising the
inextensibility of each element of the armature. This convention shall apply to the
description as well as to the claims and to the descriptive abstract.
With regards precisely to the armatures, the inventor of this invention
has noticed that during the passage on the rollers, in particular the deflection rollers.
20 an extension of the upper face of the conveyor belt is produced in the longitudinal
direction and a compression of the lower face of the conveyor belt in the longitudinal
direction, with this extension and this compression being transmitted to the upper
plate of the device for linking and respectively to the lower plate, of the device for
linking.
25 These distortions are detrimental to the duration of use of the links. A
stoppage of a conveyor belt not only generates repair fees but also the corresponding
loss in production ofthe industrial facility of which itis a part.
That is why in prior patents, in particular in US patent 5 839 571, in the
name of Jakob, the inventor of this application proposed to provide the armatures of
30 the upper plates and those of the lower plates with identical properties of
extendability and with identical properties of compressibility for the purpose of
handling the problem posed by the difference in travel which occurs during the
passage of the rollers, mentioned hereinabove.
However, assisted by experience in the field, the inventor of this
35 invention has observed that the effects of the measurements taken on the armatures
of the upper plates and of the lower plates, were not used to the maximum. Indeed,
3
because the armature of the lower plates and that of the upper plates were provided
with the same properties of extendability, the extension differential created between
the extension of the upper plate and that of the lower plate during the passage on the
deflection rollers, was insufficient, especially in the presence of members for
5 tensioning, which was detrimental to the transmission of force and could result in a
deterioration of the armature of the upper plate subjected to extensions of an
excessive extent.
This invention has for object to propose improvements concerning
particular and new arrangements as well as on particular and new properties, of the
10 armatures of the upper plates of devices for linking and on those of their lower plates,
whether or not these plates are connected by a central portion and that this central
portion when it exists is, or is not connected to the plates being integral with the
latter or by being added. These improvements have for purpose to optimise the
service life of devices for linking in service in particular in the case of cumbersome
15 installations.
The invention also has for object to propose an arrangement of the
armatures that makes it possible to make devices for linking able to be mounted on
conveyor belts of different thicknesses.
After the execution of practical tests, the inventor of this invention
20 application obtained excellent results by providing the upper plate with an armature
of which the properties of extendability and of compressibility contrast sharply with
those of the armatures of the lower plate. In other terms, this invention has for object
a device for linking conveyor belts comprising two linking elements that have the form
of plates made of elastomer or of a synthetic material, with the plates comprising
25 armatures, one of the plates, referred to as the upper plate, being, during use,
arranged against the outer face of the ends of the conveyor belt and the other plate,
referred to as the lower plate, being, during use, arranged against the inner face of
the ends of the conveyor belt, the two plates being, during the use of the device for
linking, subjected to the ends ofthe conveyor belt using known means, remarkable in
30 that the device for linking is provided with armatures of which the properties of
extendability and of compressibility, in the horizontal direction, differ very sharply,
according to their arrangement in the device for linking, and in that the limit of
extendability of the highly extendable armatures under the effect of the forces of
traction is not reached before, under the effect of equivalent forces of traction, the
35 rupture of the inextensible or quasi inextensible armatures occurs.
ii
I'
I
11·.'·'.
------··--
4
Generally, and in the scope of this invention, the term "highly
extendable" means that the extendability of the armature is at least greater than
about 15%, and preferably even greater than about 20%. In the same way, the term
"inextensible, or quasi inextensible" means that the maximum extendability of the
5 armature does not exceed about 3%. In this way, it is understood that the properties
of extendability and of compressibility of armatures differ, in particular sharply.
A first combination of armatures has been tried and has given excellent
results. In this combination the upper plate was provided with a highly extendable
armature. The extend ability of this armature cart commonly range up to 20% of the
10 initial length before application afforce in the longitudinal direction, i.e. the direction
of travel of the conveyor belt, once the device for linking is mounted. The
extendability can moreover be, if necessary, much greater, for example up to 60%.
Preferably, the extendability of the highly extendable armature is between 15% and
60% and more preferably between 20% and 60%. The lower plate is provided with an
15 _ inextensible, or quasi inextensible, armature, witb its maximum extendability not
exceeding about 3%.
Due to the strong contrast the extension differential at the passage of the
rollers is maximal but the extension of the extendable armature of the upper plate
does not reach its possible maximum before the rupture of the inextensible or quasi
20 inextensible armature of the lower plate. As the transmission of the traction forces is
provided by the armature of the lower plate the resistance to the rupture of the latter
is chosen according to the uses provided for the conveyor belt, with a safety
coefficient. It is understood that the probability of fatigue or of a deterioration of the
device for linking is as such greatly reduced. Note that this version of the invention
25 can be applied to various devices for linking with the condition that they comprise an
upper plate and a lower plate, and that, whether or not there is a central portion that
connects the two plates and that if one does exist itis integral with the two plates or
is added.
This invention further proposes a decisive solution relating to the
30 adaptability of devices for linking to different conveyor belt thicknesses. In this
solution the upper plate and the lower plate are connected by forming a single part
with a central connecting portion arranged diagonally. This arrangement combines the
adaptability of the device for linking with the mounting on conveyor belts of different
thicknesses and the properties of armatures concerning the extendability and the
35 compressibility of the armatures in the longitudinal direction of the conveyor belt.
5
Said central connecting portion is constituted of an inextensible or
practically inextensible canvas coated with elastomer. This connecting portion is
arranged at an angle between the upper plate and the lower plate and is integral on
the one hand with the upper face of a side of the lower plate and on the other hand
5 with the lower face of the upper plate, on the side opposite the upper plate. The
inextensible or quasi inextensible canvas coated with elastomer of the central
connecting portion is extended on one side over the lower face of the upper plate
with which it is integral and on the other side with the upper face of the lower plate,
with which it is integral.
10 This arrangement makes it possible to use the properties of
inextensibility, or of quasi inextensibility of this third armature common to the two
plates, but in addition to the fact that the connecting zones between the central
connecting portion and the upper face of the lower plate on the one hand and the
lower face of the upper plate on the other hand constituent pseudo-hinges, it allows
15 for a clearance that makes it possible to separate, or to approach, the upper plate and
the lower plate, as such making it possible to mount devices for linking of this version
on conveyor belts of different thicknesses.
In addition, note that the devices for linking of this version can be
reversed, i.e. they can be mounted indifferently by inverting the upper plate and the
20 lower plate, which therefore excludes the possibility of an erroneous mounting, with
the proprieties of substantial extendability and those of zero or quasi zero
extendability, being retained.
The inventor has also provided that the inextensible; or quasi
inextensible armatures used in the various embodiments can be constituted of
25 canvases of the type of those used in machines for manufacturing paper wherein they
are used as screens and support for transporting the paper being formed and which
are constituted of a weaving of inextensible, or quasi-inextensible metal cables, of
inextensible, or quasi-inextensible metal wires, or of inextensible, or quasiinextensible
filaments made of synthetic material. As these canvases mounted as
30 armatures of plates of the device for linking according to the invention would possibly
be subjected to a combing effect, the inventor provided that in the case of the
presence of means for fastening with a stem such as clamps, rivets, screws, the edges
of these fabrics, i.e. the edges of the textile used for making the inextensible, or quasi
inextensible armatures, be, in the devices for linking according to the invention,
35 arranged perpendicularly to the direction of travel of the conveyor belt which is that
of the device for linking mounted on the conveyor belt.
------~·-- -------~-----------------
6
The invention shall now be described in a detailed manner applied to
preferred but not exclusive embodiments, shown by the drawing wherein:
figure 1 shows a device for linking of prior art, seen in perspective and as a
cross-section;
5 figure 2 shows the same device for linking of prior art mounted on the ends of
a conveyor belt, passing on a deflection roller;
figure 3 shows, in perspective, a first device for linking according to the
invention;
figure 4 shows, as a longitudinal cross-section, the device for linking of figure 3,
10 mounted on the end of a conveyor belt;
figure 5 shows, as a longitudinal cross-section, the device for linking of figure 3,
mounted on the ends of a conveyor belt, passing on a deflection roller;
figure 6 shows as a longitudinal cross-section a second device for linking
according to the invention;
15 figure 7 shows the device for linking of figure 6, mounted on the ends of two
conveyor belts of different thicknesses in two views a and b;
figure 8 shows the device for linking of figure 6 mounted on a conveyor belt,
passing on a deflection roller.
The same references are used on the same parts or portions in all of the
20 figures of the drawing.
- Figure 1 shows a device for linking of prior art. Note an upper plate 2
reinforced in this case by parallel, superposed and crossed sets 4 of cables, and a
lower plate 3 reinforced in the same way as the upper plate by sets 4'. Optionally, as
mentioned hereinabove, a central portion 5 connects the lower plate and the upper
25 plate.
-Figure 2 shows the device for.linking of figure 1 mounted on a conveyor
belt, during the passage on a roller. Note the roller of radius R, the ends E of the
conveyor belt, the lower plate and the upper plate provided with armatures. The
distance between the upper face of the upper plate and the lower face of the lower
30 plate is dimensioned e. It is understood that the difference in travel is roughly
calculated according to the formula
180 fltravel = [2rr(R +e)- 2rrR] ~or rr(R +e) -rrR
360
·with the travel taking place only over about 180·, not 36o·.
- Figure 3 shows a first device for linking according to the invention, as a
35 longitudinal cross-section. The various elements are shown as follows:
{2) upper plate
7
(3) lower plate
(5) central portion (recall that the central portion may either not exist, or is
integral with the plates, or is added).
(7) armature extendable and compressible in the longitudinal direction
5 (8) inextensible or quasi inextensible armature.
It is understood that as the armature 8 of the lower plate 3 is
inextensible, the effect of the difference in travel applies entirely to armature 7,-highly
extendable; of the upper plate 2. As the maximum extension of the extendable
armature is not reached before the inextensible armature reaches its limit of rupture
10 the highly extendable armature can never be subjected to forces of traction that,
otherwise, could result in deteriorating it. As the inextensible armature has been given
resistances to rupture that are compatible with the forces of traction that are exerted
during the operation of the conveyor belt, with of course a safety coefficient, the
inextensible armature, for the transmission of force, is used as a fuse". As such the
15 two armatures are sheltered from deterioration and the service longevity of the
device for linking is maximal.
With regards to the resistance to rupturing of the inextensible armature
compatible with the forces of traction that are exerted during the operation of the
conveyor belt, it is understood that the latter is chosen freely by those skilled in the
20 art according to the desired application. An inextensible armature will as such be used
having a relatively low resistance for a device for linking for a light and thin conveyor
belt, for example intended to transport food products, and an inextensible armature
will be used having a relatively high resistance in the case of a device for linking for a
heavy conveyor belt, for example intended to transport ore.
25 - Figure 4 shows, as a longitudinal cross-section, the device for linking of
figure 3, mounted on the end of a conveyor belt. The armature of the upper plate 7,
extendable, the inextensible, or quasi inextensible armature 8 of the lower plate are
found. The fastening is provided here by clamps C.
- Figure 5 shows the passage on a deflection roller of the device for
30 linking of figure 3. It is clear that the highly extendable armature 7 has yielded, by
being extended by the difference in travel between that of the lower plate and that of
the upper plate, with the inextensible armature 8 not being extended, or practically
not. The reference R indicates the radius of the roller, the reference e indicates the
thickness of the device for linking, the reference E the ends of the conveyor belt
35 whereon the device for linking is mounted.
8
-Figure 6, showing a second device for linking according to the invention,
makes it possible to see it mounted on a conveyor belt, passing on a deflection roller,
as a cross-section, an armature 7a highly extendable being arranged in the upper plate
2 and another armature, highly extendable 7b being arranged in the lower plate 3. A
5 third flexible and inextensible armature 9 connects, by being integral with them by the
material with which it is coated, the upper plate 2 and the lower plate 3, a portion 9'
of this armature 9 being integral with one of the sides, the left side 3', of the upper
face of the lower plate, another portion 9" of this armature 9 being integral with the
other side, the right side 2', of the lower face of' the upper plate 2, a slanted central
10 portion 9"' for connecting of said third armature 9 connecting the two portions 9' and
9" by forming two pseudo-hinges lOa, lOb on the connecting zones with respectively
the upper plate 2 and the lower plate 3.
- Figure 7 shows, view a, the device for linking of figure 6 mounted on a
conveyor belt of a first thickness EP and, view b, the same device for linking of figure 5
15 mounted on a conveyor belt of a second thickness EP', greater. It is understood that
this adaptation can be made thanks to the pseudo-hinges lOa, lOb that authorise a
coming together, or a separation, of the plates 2, 3. Note that this device for linking
can be reversed, the notion of upper plate and of lower plate being used only for the
description.
20 - Figure 8 shows the device for linking of figure 6 mounted on a conveyor
belt, passing on a deflection roller. All of the elements of figure 6 are found, namely
the plates 2, 3, the extendable armatures 7a, 7b, the inextensible armature 9 and its
various portions 9', 9", and 9'".
The differences in travel are absorbed thanks to the extendable
25 armatures 7a and 7b. The transmission of force is provided by the inextensible
armature 9.
As such are achieved all of the purposes pursued by the invention, i.e. a
certain increase in the service longevity of devices for linking according to the
invention and the adaptability for mounting on conveyor belts of different thicknesses
30 of a device for linking which, in addition, has the advantage of being able to be
reversed, i.e. able to be mounted without the risk of an error in positioning the plates.

CLAIMS
1. Device for linking conveyor belts comprising two linking elements
having the form of plates made of elastomer or of synthetic material, with the plates
comprising armatures (7, 7a, 7b, 8, 9), one of the plates, referred to as the upper plate
5 {2), being, during use, arranged against the outer face of the ends (E, E) of the
conveyor belt and the other plate, referred to as the lower plate (3), being, during use,
arranged against the inner face of the ends of the conveyor belt, with the two plates
{2, 3) being, during the use of the device for linking, subject to the ends of the
conveyor belt using known means,
10 characterised in that
the device for linking is provided with armatures (7, 7a, 7b, 8, 9) of which the
properties of extendability and of compressibility, in the horizontal direction, differ
greatly, according to their arrangement in the device for linking,
and in that the extendability limit of the highly extendable armatures (7, 7a, 7b) under
15 the effect of the forces of traction is not reached before, under the effect of
equivalent forces of traction, the rupture of the inextensible or quasi inextensible
armatures {8, 9) occurs.
2. Device for linking according to claim 1
characterised in that armatures (8, 9) are inextensible or quasi inextensible and are
20 constituted of a weaving of inextensible, or quasi inextensible metal cables, of
inextensible, or quasi inextensible wires, or of inextensible, or quasi inextensible
. filaments made of synthetic material.
3. Device for linking according to claim 2
characterised in that
25 the edges of the textile used for making the inextensible or quasi inextensible
armatures. (8, 9) are arranged perpendicularly to the direction of travel of the
conveyor belt, with the device for linking being mounted on the latter.
4. Device for linking as claimed in any preceding claims,
characterised in that the extendability of the highly extendable armatures (7, 7a, 7b)
30 can range up to about 20% of their dimension at the idle state.
5. Device for linking according to any of claims 1 to 4,
characterised in that the armature (7) of the upper plate (2} is highly extendable and
compressible in the longitudinal direction, while the armature (8) of the lower plate
(3} is inextensible or quasi inextensible in the longitudinal direction.
35 6. Device for linking according to any of claims 1 to 4,
------------
10
characterised in that the armatures (7a, 7b) of the upper plate (2) and respectively of
the lower plate (3) are highly extendable and in that a third inextensible or quasi
inextensible armature (9) is arranged to be integral, thanks to the material with which
it is coated, with on the one hand the upper face of the left side (3') or with that of the
5 right side (3") of the lower plate (3) and on the other hand with the lower face of the
right side (2'') or with that of the left side (2') of the upper plate (2), a slanted central
portion for connecting (9"') ·of said other third armature (9) that connects its two
portions (9', 9")which are integral with respectively the lower plate (3) and the upper
plate (2), by forming as such two pseudo-hinges (lOa, lOb) on the connecting lines
10 with respectively the upper plate (2) and the lower plate (3).