WO1997028072A1

WO1997028072A1 - Conveyor belt

Info

Publication number: WO1997028072A1
Application number: PCT/NL1997/000032
Authority: WO
Inventors: Albert Jan Odink
Original assignee: Ashworth Jonge Poerink B.V.
Priority date: 1996-02-05
Filing date: 1997-02-04
Publication date: 1997-08-07
Also published as: NL1002243A1; AU1673897A; NL1002243C2

Abstract

A conveyor belt comprises a plurality of links (1) mutually connected by pivot connections (3, 4). The links (1) are mutually coupled by means of rows of aligned cams (3) which extend in transverse direction and which can co-act pivotally with pivot sleeves (4) of an adjoining link (1) which are open (6) on one side. The pivot sleeves (4) generally have the shape of a U. According to the invention an increased tensile strength is obtained in that in the middle zone of the inner surface (5) of each pivot sleeve (4) is situated a dam (16) which extends with its principal plane in the longitudinal direction and which mutually connects the legs (14, 15) of the U in an intensively strong manner; and the mutually facing cams (3) of an adjoining link (1) have a mutual distance such that the said dam (16) fits therebetween.

Description

CONVEYOR BELT

The invention relates to a modular conveyor belt with an elongate form, an upper carrying surface, a longitudinal direction and a transverse direction, comprising a plurality of links mutually connected by pivot connections such that the conveyor belt is bendable out of its principal plane and can be guided round a toothed wheel co-acting with the conveyor belt, wherein each link comprises on its longitudinal end zones a plurality of protrusions extending in longitudinal direction and a plurality of recesses present between these protrusions, which recesses have a shape such that they can accommodate the protrusions of an adjoining link, which protrusions arranged on the one longitudinal end zone have aligned pivot cams extending in transverse direction and having at least partly cylindrical form, which protrusions arranged on the other longitudinal end zone have aligned, generally U-shaped pivot sleeves which extend in longitudinal direction and the inner surfaces of which have at least on the bottom of the U a generally cylindrical form corresponding with the shape of the pivot cams such that a cam can pass through the opening of a U in order to be accommodated therein, wherein at least a number of links have a hole for accommodating a tooth of the said toothed wheel, and wherein the inner surface of a pivot sleeve optionally has a slight undercut.

Such a conveyor belt is known from the German utility model G-94 11 204.5 in the name of the present applicant. It is a first object of the invention to embody a modular conveyor belt of the said known type such that it has an increased tensile strength in the transporting direction. In respect of this objective the conveyor belt according to the invention has the feature that in the middle zone of the inner surface of each pivot sleeve is situated a dam which extends with its principal plane in the longitudinal direction and which mutually connects the legs of the U in tensively strong manner; and the mutually facing cams of an adjoining link have a mutual distance such that the said dam fits therebetween. With the structure according to the invention is achieved that, also when a relatively large tensile force is exerted on the conveyor belt, the legs of the largely U-shaped pivot sleeve are positioned relative to each other with a greater form retention. Thus is avoided that the legs of the U will move apart due to a large tensile force being exerted, whereby there would be a danger of the conveyor belt losing its integrity and the connection between the two relevant links being broken. In such a case the two links in question are no longer capable of performing the required function of pivoting and mutual tensile strength, whereby this function will be taken over by the following coupling between links in transverse direction. The conveyor belt will however have become weakened locally through the loss of a connection between two links mutually connecting in longitudinal direction, whereby there is an increased danger of a following connection in transverse direction also failing. There is therefore a great danger of the whole row of co-acting links failing along one pivot axis in the manner of a zip fastening so that the conveyor belt will break. It will be apparent that this is a very undesirable situation, particularly during operation of the conveyor belt.

The greatly increased strength of the conveyor belt due to the steps according to the invention make it highly unlikely that such a calamity will occur. It is noted that the dam does not have to extend over the whole depth of the U. It is usually sufficient if the tensile strength is ensured into a zone where the greatest transmission of power between two successive links effectively takes place. This zone will extend roughly where the part of the inner surface of a pivot sleeve with a cylindrical shape is intersected by a central plane through the relevant imaginary cylinder, which plane extends parallel to the upper surface of the link. It is generally deemed as of little use for the dam to continue further than approximately this plane.

A preferred embodiment has the special feature that the U-shape is substantially symmetrical.

In a specific embodiment the conveyor belt according to the invention has the special feature that the U-shape has a plane of symmetry extending at (90 ± 10) ^* relative to the longitudinal direction.

A variant is embodied such that the generally cylindrical shape extends through 180° increased by an undercut of a maximum of about 2x30°.

Very easy introduction of the cams into the pivot sleeves is achieved with a variant in which an outward directed widening forming the opening of the U connects to the undercut. The edges of the widening serve in this embodiment as locating edges. This can greatly simplify and accelerate a rapid assembly of the modular conveyor belt.

A preferred embodiment is embodied such that each cam has a for instance flat portion which is recessive relative to the cylindrical form and the effective diameter of which is smaller than the narrowest passage in the undercut, which recessive portion is situated on the side of the cam facing toward the carrying surface and/or the side remote therefrom such that the pivot sleeve can be displaced at least more or less in longitudinal direction over a cam until the cam is at least substantially in contact with the bottom of the U and the coupling between the two relevant links is then effected by relatively pivoting this link in the direction of a flat carrying surface. Unintentional decoupling of two mutually coupled links, for instance in the non-active return part of an endless conveyor belt, is hereby prevented.

The conveyor belt can also have the special feature that the outer end edge of a pivot sleeve of one link can pass in both directions over a soft stop, for instance a transverse edge, forming part of the other link only by exerting an increased force during the said relative pivoting movement. Undesired decoupling of coupled links of a non-tensioned conveyor belt is hereby also effectively prevented. A specific embodiment has the special feature that at least one of the two outermost protrusions of a row of protrusions embodied for instance as longitudinal edges and bearing the pivot cams has a linear dimension in transverse direction, for instance the wall thickness, which at most is as great as that of the other protru¬ sions of this row. The protrusions, which in transverse direction have half the dimension of the other protru¬ sions, can function as end element in transverse direc¬ tion or be arranged adjacently of a similarly dimensioned protrusion of an adjoining link such that these protru¬ sions together have substantially the linear transverse measurement of one other protrusion.

A preferred embodiment has the special feature that the links are monolithic. The conveyor belt can also have the special feature that the links are manufactured by injection moulding.

Strongly recommended is the variant in which the links consist of POM. Optimum replaceability is ensured with a variant in which all protrusions and all recesses are substantially identical. A specific variant has the special feature that the lower surface of the links remote from the carrying surface has a concave form.

The invention also relates to a link evidently intended and adapted to form part of a conveyor belt of the above specified type according to the invention. In contrast to the above mentioned German utility model G-94 11 204.5 such a link displays the special feature that it is evidently intended and adapted to form part of a conveyor belt as claimed in any of the foregoing claims.

The invention will now be elucidated with reference to the annexed drawings of a number of embodiments. Herein: figure 1 shows partly in side view and partly in cross section two links according to the invention for mutual coupling; figure 2 shows a view corresponding with figure 1 of a preferred embodiment; figure 3 shows the cross section III-III according to figure 2; figure 4 shows schematically, partly in cross section and partly in side view, a modular conveyor belt comprising links of the type according to figure 2 trained round the toothed wheel; figure 5 is a perspective view of two mutually coupled links; figure 6 is a perspective view of a link wherein the left-hand side wall in the figure has a reduced thickness; figure 7 shows a view corresponding with figure

6 of a variant wherein the right-hand side wall has half thickness; figure 8 shows a view corresponding with figure 6 of an embodiment wherein both side walls each have half thickness; and figure 9 shows a view corresponding with figures l and 2 of an alternative link. Figure 1 shows two identical links 1 according to the invention.

These links can be mutually connected by pivot connections such that with other such links they can form a conveyor belt which is bendable out of its principal plane. Each link comprises a plurality of protrusions or longitudinal walls 2 which carry pivot cams 3. Extending on the other side of link 1 is a pivot sleeve 4 which has an inner surface 5 with an at least partially cylindrical shape. This inner surface 5 has generally a U-shape. The cam 3 can pass through the opening 6 of the U since the partly cylindrical cam has flat surfaces 7, 8 extending in longitudinal direction and facing away from each other. Shown with broken lines 9 is that the distance between surfaces 7 and 8 is at most equal to the smallest passage of opening 6. The cam 3 can thus be introduced into opening 10 in the direction of arrow 10', whereafter by rotation in the manner shown in figure 5 in the direc¬ tion of a flat carrying surface 11 (see figure 4) the cylindrical parts 12, 13 of cam 3 can be placed into co- action with the cylindrical inner surface 5.

The legs 14, 15 of the U are mutually connected in tensively strong manner by a dam 15 extending in longitudinal direction. It will be apparent with reference to figure 4 that due to this tensively strong connection between legs 14, 15 a relatively great tensile force can be exerted on the leg 15 by the cam 3 accommodated in the U, this tensile force essentially corresponding with a pressure force exerted by the cylindrical part 12.

Each link l further displays a continuous hole 17 with rounded end faces 18, 19 for co-action with the teeth 20 of a toothed wheel 21 (see figure 4).

Attention is drawn to the fact that in figure 1 the same reference numerals are used for both links and their components. For the horizontally drawn link these are the reference numerals themselves and for the link to be inserted which is drawn in inclining position accents are added to these reference numerals.

Figure 2 shows two links 22, 22'. Accents are here also added to the reference numerals for the second link. As far as is possible and appropriate, similar or functionally similar components are designated for the sake of conciseness with the same reference numerals as in figure l and following figures.

As shown in figure 2, a significant distinction between links 22 and 1 lies in the fact that the sleeves 24 have an axis of symmetry 23 directed substantially perpendicularly of the longitudinal direction 28.

Connecting onto the inner surface 5 of the U is a widening 29 which is formed by the inner surfaces of the elongations 30, 31 of the legs 14, 15. Due to the direction in which the legs 14, 15 extend which is changed relative to figure l, the cam 3' can pass through the opening 6 to co-act with the inner surface 5. It is apparent from figure 2 that the widening 29 fulfills a locating function.

Figure 3 shows the cross section III-III as according to figure 2.

Figure 4 shows an endless conveyor belt 32 consisting of links 22. It becomes apparent from this figure that the dimensioning of the links is chosen such that the pitch distance between the holes 17 and the links 40 (see figure 9) is equal to the pitch distance of the teeth 20 at the level of the pivot axes, i.e. the axes of the co-acting pivot cams and pivot sleeves. Figure 5 shows that the end edges 33 of the elongations 31 can only pass elastically over the transverse wall 34 through the exertion of a slightly increased force.

In the variant shown in figure 5 the links 35, 36 have four longitudinal walls all designated 35 which support the cams 3. These longitudinal walls all have the same thickness. Figure 6 shows a link 36 with four longitudinal walls 35 of equal thickness and one longitudinal wall 37 with a thickness which at most equals half the thickness of longitudinal walls 35. Figure 7 shows a link 38 in which the longitudinal wall 37 of smaller thickness is situated on the other side.

Figure 8 shows a link 39 with three longitudinal walls 35 and two longitudinal walls 37 of smaller thickness situated on either side thereof.

Figure 9 shows a link 40 which differs in one aspect from the link 22 shown in figure 2. In contrast to the link 22 the link 40 has a concave lower surface 41, the radius of curvature of which corresponds with that of the toothed wheel 21 at the relevant level.

With reference to figure 4 attention is drawn to the fact that, in view of the scale of this figure, it was not readily possible to indicate that the lower surfaces 41 are curved in the manner shown in figure 9. It is pointed out that the connecting dam according to the invention shown in figure 9 extends over the whole depth of the inner space enclosed by the U.

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Claims

1. Modular conveyor belt with an elongate form, an upper carrying surface, a longitudinal direction and a transverse direction, comprising a plurality of links mutually connected by pivot connections such that the conveyor belt is bendable out of its principal plane and can be guided round a toothed wheel co-acting with the conveyor belt, wherein each link comprises on its longitudinal end zones a plurality of protrusions extending in longitudinal direction and a plurality of recesses present between these protrusions, which recesses have a shape such that they can accommodate the protrusions of an adjoining link, which protrusions arranged on the one longitudinal end zone have aligned pivot cams extending in transverse direction and having at least partly cylindrical form, which protrusions arranged on the other longitudinal end zone have aligned, generally U-shaped pivot sleeves which extend in longitudinal direction and the inner surfaces of which have at least on the bottom of the U a generally cylindrical form corresponding with the shape of the pivot cams such that a cam can pass through the opening of a U in order to be accommodated therein, wherein at least a number of links have a hole for accommodating a tooth of the said toothed wheel, and wherein the inner surface of a pivot sleeve optionally has a slight undercut, characterized in that in the middle zone of the inner surface of each pivot sleeve is situated a dam which extends with its principal plane in the longitudinal direction and which mutually connects the legs of the U in tensively strong manner; and the mutually facing cams of an adjoining link have a mutual distance such that the said dam fits therebetween.

2. Conveyor belt as claimed in claim 1, characterized in that the U-shape is substantially symmetrical.

3. Conveyor belt as claimed in claim 2, characterized in that the U-shape has a plane of symmetry extending at (90 ± 10) ° relative to the longitudinal direction.

4. Conveyor belt as claimed in claim 2, characterized in that the generally cylindrical shape extends through 180° increased by an undercut of a maximum of about 2x30°.

5. Conveyor belt as claimed in claim 4, characterized in that an outward directed widening forming the opening of the U connects to the undercut.

6. Conveyor belt as claimed in claim 1, characterized in that each cam has a for instance flat portion which is recessive relative to the cylindrical form and the effective diameter of which is smaller than the narrowest passage in the undercut, which recessive portion is situated on the side of the cam facing toward the carrying surface and/or the side remote therefrom such that the pivot sleeve can be displaced at least more or less in longitudinal direction over a cam until the cam is at least substantially in contact with the bottom of the U and the coupling between the two relevant links is then effected by relatively pivoting this link in the direction of a flat carrying surface.

7. Conveyor belt as claimed in claim 6, characterized in that the outer end edge of a pivot sleeve of one link can pass in both directions over a soft stop, for instance a transverse edge, forming part of the other link only by exerting an increased force during the said relative pivoting movement.

8. Conveyor belt as claimed in claim 1, characterized in that at least one of the two outermost protrusions of a row of protrusions embodied for instance as longitudinal edges and bearing the pivot cams has a linear dimension in transverse direction, for instance the wall thickness, which is at most as great as that of the other protrusions of this row.

9. Conveyor belt as claimed in claim 1, characterized in that the links are monolithic.

10. Conveyor belt as claimed in claim 1, characterized in that the links are manufactured by injection moulding.

11. Conveyor belt as claimed in claim 1, characterized in that the links consist of POM.

12. Conveyor belt as claimed in claim 1, characterized in that all protrusions and all recesses are substantially identical.

13. Conveyor belt as claimed in claim 1, characterized in that the lower surface of the links remote from the carrying surface has a concave form.

14. Link evidently intended and adapted to form part of a conveyor belt as claimed in any of the foregoing claims.

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