Note: Descriptions are shown in the official language in which they were submitted.
W094/1~87 21 5 2 61: 3 PCT/GB93/0~99
CO~v~YOR BELT
Field of the Invention
The present invention relates to conveyor belts and
conveyors.
r~. ~.J. ~,d to the Invention
A conveyor will usually comprise an endless belt having
a conveyor surface, the belt passing around guide rollers
at both ends of its path. A tension roller is often
provided on the return length of the ~onveyor path to
maintain tension in the belt. The tension roller bears
10 on the ~onve~or surface side of the belt.
It is now common, especially in belts which have to
convey articles up an incline, for flights to be provided
to avoid slippage of articles on the ~o.-veyor surface.
Where the tension roller is not adapted to operate with
15 the flights, for instance where the conveyor was not
designed for use at an incline or where a new design of
belt is being used, the flights will collide with the
tension roller as they pass it causing wear and/or damage
to the tension roller and/or the flights.
In an attempt to overcome this problem, United States
Patent No 4,911,286 suggests the use of tongues cut from
the belt, ie a generally U-shaped cut being made, and a
projection being disposed at the trailing edge of the
tongue to act as a flight. The tongue can effectively
25 pivot about its end, still connected to the belt, so
that, as it contacts the tension roller, the flights move
a~3
away from the roller to reduce wear and/or damage.
European Patent publication number 362499 suggests a similar system in
which a projection is mounted upon the belt surface between two parallel slots cut
into the belt, midway between the opposite ends of the slots. This central portion
5 of the belt can move from the plane of the belt by pivoting about the axes defined
between the respective slot ends which allows the projection to move away from the
roller.
However, it has been found that this continual flexing of the belt leads to
fatigue problems associated with the belt material.
Summary of the Invention
According to the present invention, there is provided a conveyor belt
comprising a conveyor belt comprising a conveyor side and a reverse side opposite
to the conveyor side, and a flight extending from the plane of the belt on the
conveyor side, the flight being movable whereby the conveyor system can pass a
15 tension roller engaging the conveyor side of the belt characterised in that the
conveyor belt includes at least one generally transverse opening in the belt and in that
the conveyor system includes a support member separate from the belt, at least part
of which support member projects through the opening to provide the flight, means
cooperating between the support member and the opening to support the flight in a
20 position extending from the plane of the belt but allow rotation of the flight to lie
substantially parallel to and against the conveyor side of the belt whereby the support
member can pass a tension roller engaging the conveyor side of the belt.
Such an arrangement has the advantages that it requires a minimum of
modifications to the belt, there is less flexing of the belt material substantially
25 reducing fatigue and, if the support member becomes worn or if particular shapes are
required, the support member can be replaced very easily.
~`5a(~`3
2a.
In a preferred construction, the support member is generally L-shaped in cross-
section, comprising a body and a foot attached to the body, the foot being generally
perpendicular to the body whereby, in use, the body extends generally perpendicular
to the conveyor side of the belt, the foot extends generally parallel to the reverse side
5 and when the body lies generally parallel to the conveyor side, the foot extends
generally perpendicular to the reverse side. This construction provides a simple and
effective means for reversing the position of the support member to enable it to pass
the tension roller and to relocate the flight on the belt as the foot engages a guide
roller at one end of the belt's path before returning to the conveying portion of its
1 0 path.
W094/1~87 215 2 61 3 PCTIGB93/0~99
The belt and support member have been found to provide
the correct degree of resistance to articles placed on
the belt on the conveyor side while being moved by the
tension roller with minimal difficulty if the mean`s
cooperating between the support member and the belt
include slots each extending from either end of the stop
at the juncture of the body and the foot. Preferably,
the op~i n~ comprises circular holes through the belt at
either end of a slit and the slots in the support mem~er
10 terminate in generally circular holes the centres of
which are spaced apart by the distance between the
centres of the holes at either end of the slit. The holes
through the belt help to prevent tears.
The support member is positioned in the opening such
15 that the foot trails the body as the conveyor belt moves.
The support member may comprise a body and foot of
equal length with each of the body and foot comprising a
generally rectangular plate. However, in some cases the
support member may include two feet depending from the
20 body such that the belt includes two aligned openings
through which the feet project. In this way an elongate
flight can be produced without requiring such a long slit
to be cut into the belt. In some cases this is n~r2c~ry
to maintain the strength of the belt.
The support member may have cut away edges in order to
prevent the support member catching on parts of the
~o.,~eyor belt.
The support member may be of any material of sufficient
strength and resilience. In some cases the support
30 member is a polyurethane but it may include a polyester
liner to reduce friction.
It will be apparent to the skilled addressee of the
specification that the length of support member, height
of body and depth of foot will be varied in accordance
35 with its intended use.
According to the present invention, there is also
provided a conve~or comprising a conveyor belt according
to the pr~rP~ing paragraphs.
WOg4/1~87 215 2 6 13 PCT/GB93/0~99
4.
According to the~ present invention, there is also
provided a support member adapted for use as a flight
with a ~ollveyor or conveyor belt according to the
pre~e~ing paragraphs.
The invention is particularly advantageous when used
for inclined ~on~eyors.
Brief Description of the Drawings
Two examples of the invention will now be described, by
way of example only, with reference to the drawings that
10 follow; in which:-
Figure 1 is a schematic side elevational view of a
conveyor in accordance with the present invention;
Figure 2 is a schematic enlarged plan view of part of a
conveyor belt for use with the present invention;
15 Figure 3 is a schematic enlarged perspective view of a
first support member for use with the present invention;
Figure 4 is a schematic enlarged side elevational view of
the present invention showing the support member in its
~oll~e~ing and "rest" positions.
20 Figure 5 is a schematic enlarged perspective view of a
second su~o.~ member for use with the present invention.
Description of the Preferred Embodiments
Referring to Figures 1-3 of the drawings, there is
shown a conveyor belt 2 comprising a conveyor side 6, a
25 reverse side 8 opposite to the conveyor side 6 and at
least one generally tranverse opening 10 in the belt 2;
and a support member 12 separate from the belt 2, at
least part of which support member 12 projects through
the opening 10 to provide a flight 14 extending from the
30 plane of the belt 2 on the co~lveyor side 6 and means
cooperating between the support member 12 and the opening
10 to allow the support member 12 to be moved to lie
substantially parallel to and against the conveyor side 6
of the belt 2 so that it can pass a tension roller 20
35 engaging the conveyor side 6 of the belt 2.
In Figure 1, a conveyor 4 carrying the belt 2 is shown
inclined at an angle of about 40 degrees to the
horizontal. The conveyor 4 has guide rollers 22, 24 at
- ~Isa~l3
either end of the path of the belt 2, either one or both of which guide rollers 22, 24
can be driven by known means. The length of the belt 2 between the guide rollers22, 24 on the side opposite the tension roller 20 comprises a conveyor portion 16.
The guide rollers 22, 24 engage the reverse side 8 of the belt 2, while the tension
5 roller 20 engages the conveyor side 6 of the belt 2, the belt 2 is driven in the
direction indicated by arrow F.
The belt 2 is formed from a polyurethane material having elastic resilience, or
from other such materials well known to those skilled in the art. The belt 2 is 2
millimetres thick.
The opening 10 is shown in more detail in Figure 2 and comprises an elongate
slit 26 terminating, at either end, in holes 28, 30. The opening 10 is cut or formed
in the belt 2 to be of minimal width. However, the width of opening 10 may be
adjusted to improve the performance of the support member 12. The holes 28, 30
are cut, drilled or otherwise formed in the belt 2 to have a diameter to suit the
15 thickness of the belt 2. The distance A between the centres of the holes 28, 30 is
dependent on the width of the belt 2; in this case it is 100 millimetres.
Figure 3 shows the support member 12 in more detail. The support member
12 is produced by injection moulding, extrusion and/or high frequency welding from
a plastics material such as polyurethane. The support member 12 comprises a body20 portion 32 and a foot 34 extending generally perpendicular from the body 32 to form
a substantially L-shaped elongate member. The height B of the body 32 in this
embodiment is 50 millimetres. The height B-is chosen so that it is sufficient toconvey articles 43 up the incline of the conveyor 4 while being short enough relative
to the tension roller 20 to be rotated into its non-conveying "rest" position as25 described below. Generally, the height B of the body portion 32 should be no more
than the radius of the
_ WO94/1~87 ~ 215 2 613 PCT/GB9310~99
6.
tension roller 20. However, larger body portions 32 have
been found to work.
The length C of the foot 34 in this ~mho~l rQnt is 25
millimetres. The length C is chosen to keep material and
manufacturing costs to a minimum. The length C of foot
34 must be sufficient to hold the support member 12 in
position when it is inserted in the opPning lO (as
described below) and to allow the guide roller 22 to
rotate the body into its ~unve~ing position (as described
10 below). The maximum length C of the foot 34 should be
the radius of the guide roller 22. Larger feet 34 can
work.
At the juncture of the body 32 and foot 34 are two
substantially parallel rectilinear slots 36, 38
15 terminating in holes 40, 42. The two slots 36, 38 are
substantially identical so only one of them will be
described here for convenience. Slot 36 extends from one
end of the support member 14 part of the distance towards
the centre of the support member 14 and terminates in the
20 hole 40. The slot width D in this embodiment is 2
millimetres and is ~hoc~n to be equal to the thickness of
the belt 2. The hole 40 has a diameter of 3 millimetres
(chosen to be 1 millimetre greater than the width of the
slot 36) which is equal to the radius of the holes 28, 30
25 in the belt 2. The slot 36 and hole 40 are formed eg as
part of an injection moulding, or in post production from
an extrusion at 45 degrees to the planes of the body 32
and foot 34, ie the slot 36 and hole 40 are symmetrical
about the juncture of the body 32 and foot 34.
The holes 40, 42 are spaced apart by a distance E
which, in this embodiment, is 100 millimetres, ie the
same as the spacing A between the holes 28, 30 in the
belt 2.
To insert the support member 12 into the opening 10 in
35 the belt 2, the support member 12 is forced through the
opening 10, relying on the elasticity of the material of
the belt 2, until the belt 2 springs back into the slots
36, 38 thereby holding the support member 12 in position.
~l5~l3
Either the body 32 can be forced through from the reverse side 8 or the foot 34 can
be forced through from the conveyor side 6. In this position, the holes 28,30 and
the belt 2 and holes 40,42 in the support member 12 overlap. Ideally, the axes of
the holes 28 and 42 intersect as do the axes of the holes 30 and 40. However, given
5 the manufacturing tolerances to which the support member 12 and opening 10 canbe formed, while keeping the costs of manufacture down, this will not always be
possible. However, the holes 28 and 42 should overlap as should the holes 30 and40.
In order that the support member 12 can be inserted into the opening 10, it will10 be appreciated by those skilled in the art that the distance A between the holes 28
and 30 (which is the same as the distance E between the holes 40,42) needs to belarge enough to permit the support member 12 to be inserted in the opening 10
without stretching the belt 2 beyond its elastic limit. If necessary, the foot 34 can
be narrower than the body 32 to aid in this insertion into the opening 10.
Referring now to Figures 1 and 4, the operation of the present invention will
now be explained.
In Figure 1, the support members on the conveyor portion 16 of the belt 2 have
the bodies 32 of each of the support members 32 upstanding from the belt 2 so that
the support members 12 form flights 14 generally perpendicular to the plane of the
conveyor portion 16 of the belt 2. In this position, the flights 14 can be used to
prevent articles 43 such as parcels, food products etc, from slipping down the belt
and drive them in the direction indicated by arrow F. The feet 34 of each of thesupport members 12 can be seen on the reverse side 10 of the conveyor belt 2 Iying
generally parallel to and against the belt 2.
Surprisingly, it has been found that the arrangement of slit 10 and slots/holes
36, 38, 40 and 42 (together comprising the cooperating means) interengage
sufficiently to prevent the support member 12 from being
al5~13
rotated, in Figure 1 in an anti-clockwise direction, so that the body 32 lies against the
conveyor side 6 of the belt 2. If this were to happen, the support members 12
would, effectively, cease to perform their function as flights 14.
The support members 12 continue in their path around guide roller 24. The
5 support members 12 do not interfere with the operation of guide roller 24 as they
pass around it because the feet 34 of the support members 12 which project on the
reverse side 8 of the belt 2, and hence engage guide roller 24, are Iying generally
parallel to and against the surface of reverse side 8. The additional thickness of the
feet 34 can be taken up by the resilience and elasticity of the belt 2.
The support members 12 then continue towards the tension roller 20. As
referred to above, if the support members 12 were to remain in the position theyadopt along the conveyor portion 16 of the belt 2 as they pass the tension roller 20,
damage and/or wear would occur between the tension roller 20 and the support
members 12. However, as the top of the body 32 engages the tension roller 20, the
15 support member 12 is rotated from its conveying position to its "rest" position (as
shown in ghost-lines in Figure 5). The tension roller 20 rotates the support member
12 whereas the articles 43 do not because: (1) the tension roller is fixed in place and
hence provides a greater resistance to the support members 12; and (2) the tension
roller 20 engages the top of the body 32 causing a larger turning force than that
20 caused by the articles 43 which, typically, engage the body 32 nearer its juncture
with the foot 34.
Thus, the support member 12 is rotated to its "rest" position, in which the
body 32 lies generally parallel to and against the conveyor side 6 of the belt 2, by the
tension roller 20 allowing it to safely pass the tension roller 20 in the same way as
25 foot 34 passed the guide roller 24. In this "rest" position, the foot 34 is upstanding
from the reverse side 8 of the belt 2, ie the
_ W094/1~87 21 5261 3 PCT/GB93/0~99
reverse of the conveying position of the support member
12.
The support members 12 next engage the other guide
roller 22 which performs the opposite operation to
tension roller 20 and rotates the support members 12,
referring to Figure 1 in a clockwise direction, to return
the support members 12 to their conveying position. As
this operation is substantially the same as that
described above in relation to tension roller 20, it will
10 not be repeated here.
The operation described above is then repeated as the
belt 2 continues around the guide rollers 22, 24. In the
event that a support member 12 needs to be changed, it
can easily be removed by following the reverse of the
15 insertion steps referred to above and then replaced by a
new support member 12. Similarly, support members of
different widths, shapes and/or materials can be inserted
for other applications.
A second embodiment of the invention is illustrated in
20 Figure 5 which shows a second example of a support member
for use with a conveyor belt. The support members 44 is
produced from a sheet of polyurethane material having
elastic resilience lined with a polyester liner to cut
down friction. A shape is cut from the sheet of material
25 and the feet are then heat formed to the perpendicular as
shown in Figure 5. The su~po~ member 44 comprises a
body portion 46 and two feet 48, 50 both ext~n~ing
generally perpendicularly from the body 46 to form a
substantially L-shaped elongate member.
The length F of the body is 30cm. The feet 48, 50 are
of unequal length with the foot 48 being attached to the
body 46 along G which is equal to 4.7cm. The longer foot
50 is connected to body 46 by distance H equal to 9.6cm.
In order to cooperate with a conveyor belt, two slots of
35 length 4.7cm and 9.6cm are cut into the belt which are
colinear. This allows for a long body to be used to
provide an elongate flight but without requiring an
e~e...~ly long opening to be cut. For instance, in the
- 2 1 1 o . PCT/GB93/02399
example shown, if the foot was a one piece foot the
length of the opening required would be equal to length I
which is 24.5cm which would considerably weaken any
conveyer belt into which it was placed.
The different lengths of the feet 48, 50 are chosen
dependent upon other parts of the apparatus into which
the ~Gl-veyor is to be installed. Here the height J of
the body is equal to 5.lcm with the beam being 2.2cm.
As can be seen, at the junction of the body 46 and the
feet 48, 50, are three rectilinear slots 52, 54, 56.
These are substantially parallel and do not terminate in
a hole since the two layer material used for this support
member will not wear. The material is flexible but
resilient to allow for ready insertion into a conveyor
15 belt. The use of two feet of shorter length aids
insertion into the belt.
It can be seen that the body 46 is not rectangular, it
has curved edges to ensure that these do not catch upon
parts of the apparatus in connection with which the
20 conveyor is to be used.
