WO1997002196A1

WO1997002196A1 - Conveyor belt

Info

Publication number: WO1997002196A1
Application number: PCT/SE1996/000884
Authority: WO
Inventors: Lennart Olsson
Original assignee: Frigoscandia Equipment Ab
Priority date: 1995-07-03
Filing date: 1996-07-02
Publication date: 1997-01-23
Also published as: AU6325796A; SE9502405D0; SE504656C2; SE9502405L

Abstract

A conveyor belt comprises a plurality of link means (1), which are successively connected in series and each of which has two transverse rods (2, 3), which are spaced apart in the longitudinal direction of the conveyor belt and which at each lateral edge of the conveyor belt are fixedly interconnected by a link (4) which connects the link means with the adjoining link means on the one hand pivotally about axes substantially in parallel with the transverse rods and, on the other hand, displaceably in the longitudinal direction of the conveyor belt. A grating of a first type (8) is arranged between the two transverse rods (2, 3) of each link means (1), said grating having a connecting strut (10) which is extended between the transverse rods in the longitudinal direction thereof and which has cantilever branch struts (11, 12) which are arranged transversely of the connecting strut and which are each directed to the associated transverse rod and by means of which the grating is fixable to the link means. A grating of a second type (9) is arranged between each pair of two neighbouring gratings of the first type (8), said gratings of the second type having a plurality of slide struts (13) with two ends (14, 15), each of which extends between two adjoining branch struts (11, 12) of its associated neighbouring grating of the first type and is fixedly connected to a corresponding end (14, 15) of at least one adjoining slide strut under the intermediate branch strut (11, 12).

Description

CONVEYOR BELT

The present invention generally relates to conveyor belts and especially a foraminous conveyor belt, which comprises a plurality of link means, which are succes¬ sively connected in series and each of which has two transverse rods, which are spaced apart in the longitu¬ dinal direction of the conveyor belt and which at each lateral edge of the conveyor belt are fixedly intercon¬ nected by a link which connects the link means with the adjoining link means on the one hand pivotally about axes substantially in parallel with the transverse rods and, on the other hand, displaceably in the longitudinal direction of the conveyor belt.

Such a conveyor belt is disclosed in e.g. US-A- 5,190,143, in which the movability of the link means relative to each other is used to let the conveyor belt travel in a helical path as well as round guide rollers. According to US-A-5, 190, 143, use is conventionally made of metal wires that are helical in a substantially flat¬ tened fashion, or zigzag wire spirals for providing a foraminous carrying surface of the conveyor belt. When mounting such a known conveyor belt, the wire spiral must be passed onto two or more transverse rods, which is a relatively time-consuming operation. Moreover, the wire spirals form two layers of wires, i.e. one above the transverse rods and one below the same, which is not always quite satisfactory in respect of air resistance straight through the conveyor belt. The position of the wire spirals relative to the transverse rods is not com¬ pletely predictable, which might be desirable. Finally, the wire spirals yield a carrying surface having a rela¬ tively small contact area for carrying conveyed goods, which results in marks being easily formed in the under¬ side of goods made of a soft material, e.g. various food products. The object of the present invention therefore is to provide a conveyor belt of the type mentioned by way of introduction, which essentially eliminates the drawbacks of the prior-art conveyor belt with wire spirals. According to the invention, this object is achieved by the conveyor belt being characterised in that a grat¬ ing of a first type is arranged between the two trans¬ verse rods of each link means, said grating having a con¬ necting strut which is extended between the transverse rods in the longitudinal direction thereof and which has cantilever branch struts which are arranged transversely of the connecting strut and which are each directed to the associated transverse rod and by means of which the grating is fixable to the link means, and that a grating of a second type is arranged between each pair of two neighbouring gratings of the first type, said grating of the second type having a plurality of slide struts with two ends, each of which extends between two adjoining branch struts of its associated neighbouring grating of the first type and is fixedly connected to a correspond¬ ing end of at least one adjoining slide strut under the intermediate branch strut.

The inventive design of the conveyor belt permits a very rapid mounting thereof by the fact that first the gratings of the second type are put down in the correct position on the upper side of the conveyor belt and then the gratings of the first type are fixed relative to the respective link means, whereby the gratings of the second type will be locked in position. Each cantilever branch strut of the grating of the first type has a free end, which can enclose one of the transverse rods of the link means to such an extent that the grating is fixed. Preferably, the free end of the branch strut extends at least partially round the side of the transverse rod facing away from the other transverse rod of the link means. Alternatively, the free end of the branch strut can, however, extend at least partially round the side of the transverse rod facing the other transverse rod of the link means. The end of each canti¬ lever branch strut is suitably so resilient that the grating of the first type is mountable by snap action over the two transverse rods of a link means.

The grating of the second type can either be such that each end of each slide strut is fixedly connected to the corresponding end of only one adjoining slide strut, or such that each end of each slide strut is fixedly con- nected to the corresponding end of both adjoining slide struts under the associated branch strut. In the first case, the grating of the second type is preferably made of a metal wire, which will then extend essentially in zigzag. In the second case, the grating of the second type is preferably made of injection-moulded plastic. A large number of further different combinations of, for instance, plastic and metal may, however, be used for the manufacture of the gratings of the first and the second type. The invention will be described in more detail below with reference to the accompanying drawings, in which

Fig. 1 is a top plan view of a prior-art conveyor belt;

Figs 2 and 3 are perspective views of a first embo- diment of a conveyor belt according to the present inven¬ tion;

Fig. 4 is a perspective view of a second embodiment of a conveyor belt according to the present invention;

Fig. 5 is a schematic top plan view of the conveyor belt in Fig. 4; and

Fig. 6 is a perspective view of the conveyor belt in Fig. 4 in retracted or collapsed state.

The prior-art conveyor belt shown in Fig. 1 com¬ prises a plurality of link means 1 connected successively in series. Each link means 1 comprises two transverse rods 2, 3, which are spaced apart in the longitudinal direction of the conveyor belt and extend over the entire width of the conveyor belt. At each lateral edge of the conveyor belt, the transverse rods 2, 3 in each link means 1 are fixedly interconnected by a link 4. Each link

4 comprises a tongue 5 having a hole which is elongate in the longitudinal direction of the conveyor belt and which receives the transverse rod 3 of the adjoining link means

1. As a result of the connection between the transverse rods 3 and the elongate holes in the tongues 5 of the links 4, each link means 1 is on the one hand pivotable relative to the adjoining link means about axes substan¬ tially in parallel with the transverse rods 2, 3 and, on the other hand, displaceable relative to the adjoining link means 1 in the longitudinal direction of the con¬ veyor belt. This relative movability of the links is shown in the right part of Fig. 1.

As also illustrated in Fig. 1, the known conveyor belt has a carrying surface, which is formed of a wire netting in the form of zigzag metal wires 6, each enclos¬ ing the transverse rods 2, 3 of its associated link means 1, and zigzag wires 7 enclosing the transverse rod 2 of a link means 1 and the transverse rod 3 of the adjoining link means 1.

In the embodiment of the present invention as shown in Figs 2 and 3, use is made of the link means 1 of the prior-art conveyor belt with links 4, which, however, are schematically shown without the tongues 5.

In the first embodiment, the carrying surface of the conveyor belt is formed of gratings of a first type 8 and gratings of a second type 9. Each type of grating may have a length which essentially corresponds to the length of the transverse rods 2, 3, but may also have a substan¬ tially smaller length than the transverse rods 2, 3. Both types of grating are suitably made of in ection-moulded plastic. The grating of the first type 8 has an elongate con¬ necting strut 10, which is adapted to be arranged between the two transverse rods 2, 3 of a link means 1. The grat- ing of the first type 8 also has a plurality of branch struts 11, 12 which are extended transversely of the con¬ necting strut 10 and are arranged in a common plane and are cantilevered. By means of these cantilever branch struts 11, 12, the grating of the first type 8 is more specifically fixable to the link means 1 by the free ends of the branch struts 11, 12 being adapted each to enclose one of the transverse rods 2, 3 of the link means 1 suf¬ ficiently to make it possible to achieve the desired fix- ing. More specifically, the free end of each branch strut 11, 12 extends partly round the side of the corresponding transverse rod 2, 3 which faces the other transverse rod 3, 2 of the link means 1. The enclosure of the transverse rod 2, 3 is about 180°, and an enclosure of at least 90° is necessary for fixing to take place. The grating of the first type 8 is mounted on the associated link means 1 by the grating being pressed down over the transverse rods 2, 3 of the link means 1, whereby the free ends of the branch struts 11, 12 yield outwards, such that the grat- ing of the first type 8 is snapped onto the two trans¬ verse rods 2, 3 of the link means 1.

Before snapping on the grating of the first type 8 to the respective link means 1, a grating of the second type 9, however, should be arranged over each transverse rod 2, 3 of the link means 1 in question. More specifi¬ cally, the grating of the second type 9 consists of a plurality of slide struts 13 having two ends 14, 15. The slide struts 13 are arranged essentially in parallel with each other and extend substantially in the longitudinal direction of the conveyor belt. The ends 14, 15 of each slide strut 13 have a downwardly directed hook 16, 17 with an internal radius which substantially corresponds with the radius of the transverse rods 2, 3. The juxta¬ posed slide struts 13 are, at the outer end of the hooks 16, 17, fixedly interconnected by means of bridges 19. The mounting of the gratings of the first type 8 and the εecond type 9 on the link means 1 is illustrated in Fig. 3. As shown adjacent the left link means 1 in

Fig. 3, first a grating of the second type 9 is arranged with its hooks 17 in engagement round the transverse rod

2, and a further grating of the second type 9 is mounted with its hooks 16 engaging round the transverse rod 3 of the same link means 1. Subsequently, a grating of the first type 8 is snapped down over the transverse rods 2 and 3 of the same link means 1, the gratings of the second type 9 being locked on the conveyor belt by the bridges 19 being positioned under their respective branch struts 11, 12. Each slide strut 13 will extend with its ends 14, 15 between two adjoining branch struts 11, 12, respectively, of one of the two neighbouring gratings of the first type 8. After snapping on the grating of the first type 8, the conveyor belt will have the appearance shown in the right part of Fig. 3 and the left part of Fig. 2. The right part of Fig. 2 shows the pushing-together of two link means 1 towards one another. In this pushing-toge- ther, the slide struts 13 will slide between the branch struts 11, 12 in the direction of the connecting strut 10. The link means 1 can be pushed together into engage¬ ment with each other, provided that the gratings of the second type 9 do not have a greater extent in the longi- tudinal direction of the conveyor belt than the gratings of the first type 8. A maximum change of the length of the conveyor belt is achieved if the gratings of the first type 8 and the gratings of the second type 9 have approximately the same dimensions in the longitudinal direction of the conveyor belt. By the branch struts 11, 12 having a greater extent adjacent to the transverse rods 2, 3 in the longitudinal direction thereof, it will be possible to push together the conveyor belt at one lateral edge thereof, without any corresponding pushing- together at its other lateral edge, i.e. in the manner shown in Fig. 1 for the prior-art conveyor belt. A second embodiment of the conveyor belt according to the present invention is shown in Figs. 4-6. In these Figures, the links 4 have been omitted. In contrast to the embodiment in Figs 2-3, the gratings in the embodi- ment according to Figs 4-6 preferably consist of metal wire which may be circular or rectangular in cross-sec¬ tion. A grating of the first type 8' conforms essentially completely with the grating of the first type 8 in Figs 2 and 3. However, the connecting strut 10' is spot-welded to branch struts 11' and 12', which are integrally formed in pairs.

In the embodiment according to Figs 4-6, use is made of a grating of the second type 9 ' which consists of a formed wire substantially in zigzag, which in each bend- ing position 20 is bent slightly downwards, the bending position thereby being located below the plane formed by the slide struts 13' of the grating, which are arranged in zigzag.

Like in the embodiment according to Figs 2-3, the conveyor belt in Figs 4-6 is mounted by first at least two gratings of the second type 9 ' being arranged over adjoining transverse rods 2, 3 of three adjoining link means 1. Subsequently, a grating of the first type 8' is pressed down over the transverse rods 2, 3 of the inter- mediate link means 1, the hook-shaped ends of these branch struts snapping over the transverse rods 2, 3. The hook of every second branch strut 11' will lock a bending position 20, and the hooks of the intermediate branch strut 12' will each lock their bending position 20, such that the grating of the second type 9 ' cannot be released from the conveyor belt, but can be displaced relative to the adjoining link means 1 and their gratings of the first type 8' . Such pushing-together of three link means 1 is illustrated in Fig. 6. The embodiments described above of an inventive conveyor belt can, of course, be modified in several respects within the scope of the invention as defined by the appended claims.

Claims

1. A conveyor belt comprising a plurality of link means (1), which are successively connected in series and each of which has two transverse rods (2, 3), which are spaced apart in the longitudinal direction of the con¬ veyor belt and which at each lateral side edge of the conveyor belt are fixedly interconnected by a link (4, 5) which connects the link means with the adjoining link means on the one hand pivotally about axes substantially in parallel with the transverse rods and, on the other hand, displaceably in the longitudinal direction of the conveyor belt, c h a r a c t e r i s e d in that a grat- ing of a first type (8; 8') is arranged between the two transverse rods (2, 3) of each link means (1), said grat¬ ing having a connecting strut (10; 10') which is extended between the transverse rods in the longitudinal direction thereof and which has cantilever branch struts (11, 12; 11', 12') which are arranged transversely of the connect¬ ing strut and which are each directed to the associated transverse rod and by means of which the grating is fix¬ able to the link means, and that a grating of a second type (9; 9') is arranged between each pair of two neigh- bouring gratings of the first type (8; 8'), said grating of the second type having a plurality of slide struts (13; 13') with two ends (14, 15; 14', 15'), each of which extends between two adjoining branch struts (11, 12; 11', 12' ) of its associated neighbouring grating of the first type and is fixedly connected to a corresponding end (14, 15; 14', 15') of at least one adjoining slide strut under the intermediate branch strut (11, 12; 11', 12' ).

2. The conveyor belt as claimed in claim 1, c h a r a c t e r i s e d in that each cantilever branch strut (11, 12; 11', 12') of the grating of the first type (8; 8') has a free end, which encloses one of the trans- verse rods (2, 3) of the link means (1) to such an extent that the grating is fixed.

3. The conveyor belt as claimed in claim 2, c h a r a c t e r i s e d in that the free end of the branch strut (11, 12; 11', 12') extends at least par¬ tially round the side of the transverse rod (2, 3) fac¬ ing away from the other transverse rod (3, 2) of the link means (1) .

4. The conveyor belt as claimed in claim 2, c h a r a c t e r i s e d in that the free end of the branch strut (11, 12; 11', 12') extends at least partial¬ ly round the side of the transverse rod (2, 3) facing the other transverse rod (3, 2) of the link means (1).

5. The conveyor belt as claimed in any one of claims 2-4, c h a r a c t e r i s e d in that the end of each cantilever branch strut (11, 12; 11', 12') is resilient, such that the grating of the first type (8; 8') is mount¬ able by snap action over the two transverse rods (2, 3) of a link means (1 ) .

6. The conveyor belt as claimed in any one of claims 1-5, c h a r a c t e r i s e d in that each end of each slide strut (13' ) is fixedly connected (20) to the corre¬ sponding end of only one adjoining slide strut.

7. The conveyor belt as claimed in claim 6, c h a r a c t e r i s e d in that the grating of the second type (9 ' ) is a metal wire formed substantially in zigzag.

8. The conveyor belt as claimed in any one of claims 1-7, c h a r a c t e r i s e d in that the grating of the first type (8' ) consists of metal wire elements ( 10' , 11', 12' ).

9. The conveyor belt as claimed in any one of claims 1-5, c h a r a c t e r i s e d in that each end (14, 15) of each slide strut (13) is fixedly connected (19) to the corresponding end of both adjoining slide struts under the respective branch struts (11, 12).

10. The conveyor belt as claimed in claim 9, c h a r a c t e r i s e d in that the grating of the second type (9) is made of plastic.

11. The conveyor belt as claimed in claim 10, c h a r a c t e r i s e d in that each end (14, 15) of each slide strut partially encloses the side of the transverse rod (2, 3) of a link means (8) facing the other transverse rod (3, 2) of the link means.

12. The conveyor belt as claimed in claim 9 or 10, c h a r a c t e r i s e d in that the grating of the first type (8) is made of plastic.

13. The conveyor belt as claimed in any one of claims 9-12, c h a r a c t e r i s e d in that the branch struts (11, 12) have an increased extent in the longitu- dinal direction of the transverse rods (2, 3) adjacent to the transverse rods.