Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1 The present invention relates -to a conveyor belt
comprising angled entraining bars, commonly referred to
in the art as "cleats", ~or vertlcally conveying b~lk or loose
material at a steep angle, and comprising corrugated
side walls and cleats o~ elastomeric material aligned
transversely thereto and arranged at substantial]y equal
1 mutual longitudinal spacings which in each instance have
! a foot or base secured to the conveyor belt and/or are
laterally secured to the crests of the ccrrugations
of the corrugated side walls of the conveying space,
and which in each case in cross-æection incorporate a
first straight lower branch approximately perpendicular
to the conveyor belt plane and a second straight branch
in continuation of the first and which is inclined with
respect thereto.
An earlier conveyor belt of this kind has cleats
located between the lateral corrugated margînal bars
(corrugated sides~ and having an angular cross-section
which are in each case formed by two straight branches,
in cross~section. Of theseg a lo~er one ex-tends approx-
imately at right angles to the conveyor belt~ whereas
the æcond upper branch is inclined with respect to the
first branch. The height of the cleats measured at right
angles to the conveyor belt plane corresponds approY~imately
to the height of the corrugated sides. The conveyor belt
is installed in such manner that the sloping second
branches of the cleats point in the upward direction of
the conveying path. The lateral corrugated sides and
the cleats between them delimit individual "boxes" for
reception of the loose material which is to be conveyed.
The conveyor belt is normally charged or loaded in a
horizontally extending section. In the steeply angled
or vertical conveying section, the second inclined
branches of the cleats prevent the loose material dropping
sideways out of the "boxes". The conveying capacity of
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1 the conveyor belt depends, ~yar-t from -the conveyor bolt
speed which cannot be increascd at wlll, on the mutual
longitudinal spacirlg of the clea-ts, that is the number
of cleats per unit of length, and on the quantity of
loose m~terial which can be retained in the steep or
vertical conveying section by each indi~idual cleat -
obviously in conjunction wi-th the lateral corrugated
sides. Limits are imposed in this case on the conveyor
belt ~described, with its singly angled cleats.
It is an object of the invention to provide a
conveyor belt of the ~ind hereinabove referred to but
whose conveying capacity is increased in an ~ncomplicated
manner.
Accordingly the invention consists in a conveyor belt
for vertical conveying loose material at a steep angle,
comprising corrugated side walls and cleats of elasto- .
meric material aligned transversely thereto and arranged
at substantially equal mutual longitudinal spacings,
which in each case have a foot or base secured to the
conveyor belt and/or ~a~erally secured to the crests of
the corrugations of the corrugated side walls of the
conveying space, and which in each case in cross-section
incorporate a first lower straight branch approximately
perpendicular to the conveyor belt plane and a second
straight branch in continua-tion of the.first and which
is inclined with respect thereto, wherein said second
branch of each cleat is followed by a straight third branch
which, in cross-section; is inclined with respect to
said second branch in the same direction as the latter
is inc~ned with respect to said first ~ranch and has
a shorter length than said second branch, said second
branch subtending an angle within the range of 40 - 65
with the plane of the conveyor belt and sa~id third branch
subtending an angle within the range of 28 - 53 with
the plane of the conveyor belt~ and wherein the length of
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l sa;d secolld brarlcll amounts to ~5~0 - 7~,0 of -the l~ngth of
said firs-t branch, arld -the length of said third branch
amoun-ts to 23'io ~ ~7'Jo o:f -th~ length ol said first branch.
~ conveyor belt according to the invention has
cleats which are angled twicc in cross-section under
retention of a particul~r cross-sectional shape deter-
mined by the angles of lnclination and relative lengths
of the three branches of each cleat. This construction
enables a particularly great conveying capacity of the
conveyor belt to be obtained in two respects, firstly
each cleat by i-tself can hold a very large volume of
loose material in -the steep or vertical conveying section
due to its cross-sectional shape, and secondly, the mutual
longitudinal spacing of the cleats on the conveyor belt
may be reduced distinctly as compared to earlier
constructions, without impairing the loadability of the
conveyor belt in the horizontal charging section. A very
pronounced slope of the cleats in the upward direction
would inhe~ntly increase the reception volume of each
individual cleat, but would simultaneously reduce the
aperture width of the individual "boxes" in the longi-
tudinal direction of the conveyor belt and thereby impair
adequate filling of the individual conveying boxes in
the horizontal charging section, which would then again
have to be balanced by an increase of the longitudinal
spacing and thereby a reduction of the overall conveying
volume. An excellent compromise between these two
opposed parameters influencing the conveying capacity
is realised by means of the cleats of particular cross-
sectional shape, in the case of a conveyor belt accordingto the invention. ~urthermore, cleats of the inventive
conveyor belt have a high degree of morphological
stability because of their shape, so that they may also
be constructed with a compar~tively great height of 400 mm
for example, which evidently also benefits the conveying
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1 c~p~city.
The conveying capacity of the inventive conveyor
belt reaches an optimum lf the mutual longitudinal
spacing of the cleats amounts to 60 to 10~/o of their
ver-tical height. The quantity o~ loose material which may
still be loaded in controllable manner into the space
between two consecutive cleats, that is into a "box",
even at the quite high conveyor belt speeds of for
example 3 ms -1 which have become customary nowadays,
then corresponds very largely to the reception volume of
the individual cleat in the vertical conveying path
section. In particular, the choice of -the longitudinal
spacing clearly depends on the nature of the loose material,
in particular on its granulometry and heaping angle.
In the case of large grain size, but also in that of a
great heap apex angle - because it leads to a higher
reception capacity of the indivîdual cleat - the
longitudinal spacing will be preferably Ghosen at the
upper end of the range specified.
In cross-section each cleat may ha~e a curvature at
the junctions between the first and second branches and
between the second and third branches, and has an
increased wall thickness in the area of the curvatures.
This construction gives the cleats a particularly great
morphological stability and at the same time improves
the delivery of ma-terial at the cleats by virtue of the
curvatures. The morphological stability may be raised
even more by means of reinforcing webs formed on each
cleat in the obtuse angle'between the first branch and
the second branch. Two inserts in each cleat may also be
used to reinforce ~he same and thereby improve its
durability, the inserts preferably consisting of steel
cords.
In order that the invention may be more clearly
understood; reference will now be made to the accompanying
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1 drawings which show one embodiment thereof by way of
exa~ple and in which:-
~ igure 1 shows an isometric view of an excislonfrom a conveyor belt for steep and vertic~l conveying of
loose material,
~ igure 2 shows a cross section through -the conveyor
belt according to Figure l, and
Figure 3 shows a longitudinal cross-sec-tion through
the conveyor belt according to ~igure 1.
Referring now to the drawings according to ~igures
1 and 2, a conveyor belt l of rubber or analogous ma~terial
and of conventional structure has each of its two edges
occupied by a corruga-ted marginal bar of rubber or the
like, constituting a corrugated side 2, which edges
protrude at approximately right angles. Cleats 5 of
rubber or the like aligned transversely to -the longi-
tudinal. direction of the conveyor belt, which subdivide
the space between the corrugated sides into separate
conveying boxes are fitted at substantially equal mutual
. 20 longitudinal dlstances on the conveyor belt (see
Figure 3). Each cleat 5 has a wide approximately T-
shaped foot or base 6 which is formed by two angular base
bars 6a and 6b. The pair of base bars 6a,6b is firmly
jolned to the conveyor belt 1 by bonding. The ac-tual
cleats are connected to the pair of base bars 6a 7 6b
by means of screws 8 so that they may be replaced if
need be.
Each cleat 5 has a double-curvature cross-section
comprising three straight branches 10, 11 and 12.
first lower branch lO is joined to the foot or base 6
and extends approximately at right angles to the plane
of the conveyor belt l. A second middle branch 11 is
inclined in the longitudinal direction of the conveyor
belt with respect to the firs-t branch and subtends an
angle of approxima~tely 53 w.ith the conveyor bel-t plane.
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1 A -third u~per branch 12 .is :inc~lined even more in the
same direc-tiorl as the second branch and subtends an
angle of approximately 41 with the conveyor bel-t plane.
The lengths of the second and third branches 11 and 12
respectively, measured in cross-section, amount -to
approximately 57% and 35~o respectively of the length
of the first branch. The height of each cleat measured
at ri~ht angles between the conveyor belt plane and the
free extremity of the third branch 12 is approxi~ately
10 8% smaller than the height of the corrugated sides 2,
so that the cle~ts may rise a little under load without
at the same time projecting above the corrugated sides.
The mutual longitudinal spacing of the cleats 5
amounts to approximately 68~o of their heightA Typical
dimensions are a corrugated side height of 400 mm and a
mutual longitudinal spacing of the cleats 5 of
approximately 250 m~.
~ ach cleat is so arranged on the actual conveyor
belt 1 that it has the lower perpendicular branch 10
positioned precisely between two mutually opposed and
inwardly facing crests 15 of the corrugations of the
two corrugated sides 2. In addition to the fas~ening to
the foot or base 6, it is laterally secured to these
crests 15 by means of bolts 16 which are anchored in
the lower branch 10 of the cleat 5 and.bol-ted to the
corrugated sides.
Three reinforcing webs ~8 extending at right
angles to the actual cleat are formed on each cleat 5
in the obtuse angle between the lower ~irst branch 10
and the middle second branch 11, whereby the bending
strength of the cleats 5 is increased. Two areal
inserts 19 of steel cords which as seen in cross-section
are embedded in each cleat wlth Mutual spacing and
extend throughout from the lower branch 10 up to close
~5 to the free extremity of the upper branch 12 fulfil
1 the sarne purpos~
~ t the -transi,tions from the :first to the second and
from the second to the third branches, each clea-t 5 has
curvatures 20 and 21 respectively. Furthermore~ the
clea-ts have an increased wall thickness in the area of
the curvatures which equally distinctly improves the
morphological stability.
The theoretical reception volume of each separate
cleat is proporti~ al to the area, see ~igure 3, which
is bounded by the cleat and the conveyor belt as well
as by the line 25 or 26, the line 25 being applicable
for loose material having a heap apex angle of 10 and
the line 26 for loose material having a heap apex angle
of 0 - both relating to vertical conveying. A charging
aperture is present between adjacent cleats in each case,
the width 27 of which determines the loadability of the
conveyor belt and of its individual conveying boxes.
In the case of the inven-tive conveyor belt, the cross-
sectional shape or form of the cleats is optimised in
such manner that a great reception volume of each cleat
is the result on the one hand, but that on the other hand
the width 27 of the charging aperture is adequa,te despite
comparatively small longitudinal spacings of the cleats
to allow of full utilisation o~' the reception volume of
the cleats by appropriate charging.
