GB2032377A

GB2032377A - Endless band conveyer

Info

Publication number: GB2032377A
Application number: GB7932289A
Authority: GB
Original assignee: Ciba Geigy AG
Current assignee: Novartis AG
Priority date: 1978-09-25
Filing date: 1979-09-18
Publication date: 1980-05-08

Abstract

A band conveyor system, which is designed to spread out material placed on one end before the material reaches the discharge point, comprises at each end of the system a pair of wheels A, C or B, D over which two endless members 3, 4 are trained, the endless members being driven in the same direction and at the same speed. Transverse to the direction of travel of the two endless members there is positioned a band which is made from a number of transversely extending elastic strips 8. Each strip 8 is attached at each end to the two endless members 3, 4. The endless members diverge in the conveying direction so as to progressively extend the length of each strip as the strip passes from one end of the conveyor to the other. In one preferred embodiment the strips lie slightly obliquely to the direction of travel of the conveyor, so that ballooning of the band as it passes around the exes of the wheels is reduced. <IMAGE>

Description

SPECIFICATION Conveyor system THIS INVENTION RELATES to a material conveyor system which incorporates a spreader band.

Conveyor systems which incorporate a spreader band are used when a quantity of items are placed on one end of the conveyor system and it is required that the items become laterally separated at the other end of the conveyor system. This can be accomplished by arranging for the width of the conveyor system to expand along the path on which the items are carried. For example the conveyor system may comprise a number of narrow belts travelling in the same direction but arranged like a fan so that the belts diverge as they travel from the loading end of the conveyor system to the unloading end of the conveyor system. However, trouble has been experienced with such systems when conveying some items because the items tend to fall between the belts as they spread apart. To overcome this defect a stretchable woven belt has been employed as a spreader band.Such belts however are very expensive and also require very secure fixing along their edges. In fact the strength of the woven belt and the fixing required is such that the high tensions lead to a high rate of wear in the conveyor system.

We have discovered a conveyor system comprising a spreader band which is effective and easy to assemble and which does not tend to cause wear in the conveyor system even after a long period of use.

According to the present invention there is provided a band conveyor system for items which comprises at each end of the system a pair of wheels over which two endless driven loops pass in the same direction and at the same speed, and a band which comprises a sufficient number of elastic material strips which are arranged substantiallytrans- verse to the direction of travel of the endless loops, each strip being attached at either end to one of the two endless driven loops, said loops being disposed to progressively extend the length of each strip as the strip passes from a point on the conveyor system at which items are placed on the band to a point at which the items are removed from the band.

There should be sufficient strips to prevent the items carried on the conveyor system from falling between two strips. In one embodiment sufficient strips are provided so that each strip overlaps a small area of its successive strip.

The strips used in the conveyor system are easy to attach to the two endless loops. As the strips are not dimensionally constrained in the direction of travel of the band, each strip may readily be stretched to provide a spread which is great compared with that of the previously used woven belts. Further, if one strip becomes worn or damaged it can easily be replaced. Thus damage to one portion of the band does not require a complete replacement of the band system as occurs when a woven belt is used.

To support the weight of the items on the band, a smooth table may be placed under the upper part of the band and supporting rollers may be placed at the ends of the conveyor system of diameter corresponding to the diameters of the wheels carrying the endless loops. Instead of rollers, fixed cylinders or part-cylinders may be provided.

In the conveyor system of the present invention there is a tendency for a ballooning effect of the band to be exhibited when the band passes at speed over rollers or or cylinders at either end. This ballooning effect is due to centrifugal forces and when it is objectionable it may be overcome by arranging for each strip to be attached not directly transverse to the direction of travel of the endless loops but obliquely to the direction of travel.

Thus according to a modification of the conveyor system of the present invention in a conveyor system as just defined the said elastic strips are arranged obliquely to the direction of travel of the two endless loops, each strip being attached at one end to a point on one loop which is ahead of the point of attachment of the other end of said strip to the other loop by a distance not exceeding six times the radius of the wheels supporting the endless loops at that end of the conveyor system at which items are placed on the band.

The accompanying drawings will serve to illustrate the invention.

Figure 1 is a side view of the conveyor system.

Figure 2 is a top plan view of the system of Figure 1.

Figure 3 is also a top plan view of the system of Figure 1 but showing a different arrangement of the strips to form the conveyor band.

In figure 1 the conveyor system comprises four driven wheels, A, B, C and D (only two are visible in this figure). Passing over the wheels A, B, C and D and driven thereby are two endless chain loops 3 and 4 (only one is visible in this figure). Located adjacent to but above wheel A is an item charging chute 5 and located adjacent to wheel B is an item receiving table 6. A smooth table 7 is located between the loops 3 and 4.

Shown joining the two endless loops 3 and 4 are a number of parallel elastic material strips 8. These are arranged to lie substantially transverse to the direction of travel of the band of the conveyor system which is indicated by the arrow placed alongside.

(Not all the strips are shown in this view).

In the conveyor system shown in figure 2 there are sufficient strips to form a complete band having no gaps therein. Further, each band overlaps slightly its successive band.

In the system shown in figures 1 and 2 the distance between wheels A and B is 145 cm.

The diameter of each wheel, A, B, C and D is 6 cm.

The width of each elastic strip 8 is 3.2 cm.

The stretched length of the first elastic strip between wheels A and C is 146 cm.

The stretched length of the last elastic strip between wheels B and D is 164 cm.

In figure 3 the same numbers have the same sig nification as those in figures 1 and 2. Also shown are two rollers 11 and 12 which supportthe conveyor system at each end. However in the case of figure 3 the strips 8 lie obliquely to the direction of travel of the band of the conveyor system. Each strip lies at an angle of approximately 83" to the direction of travel.

One end of each strip is attached at approximately 18 cm ahead of the other end of the strip. (Not all the strips are shown in this view).

When items such as cut paper sheets are placed on the conveyor system from the chute 5 they have a tendency to overlap however carefully they are placed on the conveyor band. However by the time the cut sheets have reached wheel B they are nicely separated one from the other because by this time the width of the band has expanded to 1.12 times its original width.

Each strip 8 which comprises the band is attached by a simple hook means, 9, 10 at each end thereof to each of loops 3 and 4. When a strip becomes damaged it is an easy matter two replace it.

The conveyor system shown in figure 2 shows some tendency to ballooning due to centrifugal forces acting on the strips. This tendency is considerably reduced and often eliminated by arranging for the strips 8 which comprise the band to be arranged obliquely as shown in figure 3.

With the arrangement shown in figure 2 very light items may be conveyed without required support below the strips. With the arrangement shown in figure 3, rollers or part cylinders must be placed inside the band at either end of the conveyor system to maintain the band in a part-cylindrical form of radius equal to the radius of the wheels A, C at one end and B, D at the other end.

Claims

1. Abandconveyorsystem foritemswhich comprises at each end of the system a pair of wheels over which two endless driven loops pass in the same direction and at the same speed, and a band which comprises a sufficient number of elastic material strips which are arranged substantially transverse to the direction of travel of the endless loops, each strip being attached at either end to one of the two endless driven loops, said loops being disposed to progressively extend the length of each strip as the strip passes from a point on the conveyor system at which items are placed on the band to a point at which the items are removed from the band.

2. A band conveyor system according to claim 1 wherein each said elastic material strip overlaps a small area of its successive strip.

3. A band conveyor system according to either claim 1 or claim 2 wherein a smooth table is placed under the upper part of the band.

4. A band conveyor system according to claim 3 wherein supporting rollers are placed at the ends of the conveyor system of diameter corresponding to the diameters of the wheels carrying the endless loops.

5. A band conveyor system according to any one of claims 1 to 4 wherein each strip is attached at either end to the two endless loops by a hook.

6. A band conveyor system according to either claim 4 or claim 5 wherein the said elastic strips are arranged obliquely to the direction of travel of the two endless loops, each strip being attached at one end to a point on one loop which is ahead of the point of attachment of the other end of said strip to the other loop by a distance not exceeding six times the radius of the wheels supporting the endless loops at that end of the conveyor system at which items are placed on the band.

7. A band conveyor system which comprises a plurality of elastic strips set between two endless loops substantially as hereinbefore described with reference to the accompanying drawings.