GB1604039A - Conveyor - Google Patents

Description

(54) A CONVEYOR (71) We, W S BELTS LIMITED, a British company, of Units 4 & 5 Monastery Road, Sutton, St. Helens, and WARBURTONS LIM ITED, a British Company, of Back O'Th'Bank House, Blackburn Road, Bolton, BLI 8HJ, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a conveyor.

A common requirement in mechanised handling systems which deal with a succession of solid objects (for example loaves of bread), is an accumulating conveyor. This conveys each product, which normally arrives spaced from the preceding product, at a given speed unless and until it catches up with the preceding product, when it slows down and moves at the same rate as and in contact with the preceding product. In a common arrangement, a bread slicing machine receives loaves from the conveyor.

Commonly, a group of say, 20 loaves, spaced apart, will arrive over a period of 10 seconds at the infeed end of the accumulating conveyor, followed a minute later by another group of 20 loaves. Meanwhile a slicing machine is accepting the loaves continuously, adjacent loaves being in contact with each other, at a rate of 20 loaves per minute.

The consequent ebb and flow is absorbed in the variation of the length of the "stack" on the accumulating conveyor.

The normal construction used for accumulating conveyors, known colloquially, as "magic carpet" is a conveyor surface consisting of a set of cylindrical rollers, free to rotate on spindles (but not powered). The spindles are supported and translated, thus forming a moving bed of rollers. In the absence of any obstruction, the rollers do not rotate, and any objects are carried by the rollers at the same translational speed as the spindles. If, however, there is an obstruction, the rollers rotate so that the speed of movement of the objects falls to the translational speed of the obstruction.

The established practice is to use a transmission chain at each side, to which the spindles are attached by some appropriate means. This is complex and therefore expensive to maintain and repair.

According to one aspect of the present invention, there is provided a conveyor comprising a number of connected elongate elements each of which is formed at opposite axial ends for connection to an element adjacent it so that a flexible ladder-form chain of connected elements results, chosen ones of the elements so connected rotatably supporting rollers.

A preferred embodiment of the invention may comprise any one or more of the following preferred features.

(a) Each element is made of wire.

(b) The wire of (a) is of circular cross section.

(c) The wire of (a) is heavy gauge, typically 4.5 mm diameter.

(d) Each element is U-shaped and the end of each arm of the 'U' is formed into a hook for attachment to the next adjacent element.

(e) Sprockets are provided at opposite axial ends of the elements.

(f) The sprockets of (e) at one end of the elements are of larger diameter than those at the other end.

(g) The rollers are disposed on every respective element.

(h) The rollers are disposed on every other element.

(i) Each roller comprises a hollow tube closed at opposite axial ends by respective bushes, the bore or each bush providing a running clearance over the external diameter of the element supporting it.

(j) The tube and bushes are made of synthetic plastics material.

(k) The tube is made of ABS (Acrylonitrile Butadiene Styrene) synthetic plastics material.

(I) The bushes are made of Nylatron (Registered Trade Mark).

According to another aspect of the present invention, there is provided a method of making a flexible conveyor member including the steps of threading rollers onto selected ones of a plurality of elongate ele ments to be freely rotatable forming each axial end portion of each element such that it can be connected to the other elements, and connecting the elongate elements together by means of their end portions to form a flexible ladder-form chain of connected elements.

In order that the invention may be more clearly understood, one embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a diagram of a conventional arrangement of an accumulating conveyor feeding a bread slicing machine, Figure 2 diagrammatically illustrates the operation of the accumulating conveyor of Figure 1 in the event of an obstruction, Figure 3 shows a partial view of part of a conveyor constructed in accordance with the present invention, Figure 4 shows another partial view of another part of the conveyor partly shown in Figure 3, Figure 5 shows a detailed view of a part of the conveyor parts of which are illustrated in Figures 3 and 4.

Figure 6 shows a modification of the arrangement of Figures 1 to 5, Figure 6a is a view taken on the line A-A of Figure 6, and Figure 7 shows an alternative modification of the modification shown in Figure 6.

Referring to Figure 1, an accumulating conveyor 1 feeds a bread slicing machine 2.

Loaves arrive intermittently at one end 3 of the conveyor 1 at a speed of about 60 ft/minute and are converted by the conveyor into batches of say twenty adjacent loaves each (although batches of a different or variable number may also be produced) at the other end 4 of the conveyor.

Referring to Figure 2, as long as there is no obstruction in front of an individual loaf 6, the loaf travels at the translational speed of the conveyor 1 and the individual rollers on which the loaf is supported do not rotate.

When the load 6 comes up against an obstruction, usually the load directly preceding it on the conveyor 1, the rollers supporting the loaf rotate clockwise and the loaf moves on the conveyor 1 in a direction opposite to the direction of forward movement of the conveyor itself.

Referring to Figures 3, 4 and 5, the conveyor is produced by taking a plurality of similar lengths 10 of wire of heavy gauge circular section (0.177" or 4.5 mm in diameter). Rollers 11 are threaded onto selected ones of the lengths and each roller is closed off by respective bushes 12 and 13 at opposite axial ends thereof. In the example shown, (Figure 4), rollers 11 are threaded on alternate wires but they may be threaded on every wire (or with more than one free wire between rollers) if deSired by appropriately choosing the spacing of the wires and diameter of the rollers. The limitation on roller spacing is that adequate support for objects on the conveyor must be provided.The rollers 11 are made of ABS synthetic plastics material and the bushes 12 and 13 of "Nylatron (Registered Trade Mark). The internal diameter of each bush is such as to provide a suitable running clearance over the wire diameter and collars 14, 15 are placed alongside respective bushes.

After placing the rollers on the wires the wires are bent at their ends to form hooks 16 which are hooked round adjacent wires so that a ladder of articulated links is formed.

Sprockets 17 are normally provided for support on opposite sides of the ladder, and the ladder is supported elsewhere by fixed skids.

It is possible to make ladder belt with the pitch at one side different from that at the other, so that the resulting belt takes a substantially circular curve. When this is combined with sprockets, of appropriate sizes, that is, larger in pitch on the outside of the curve, but having the same number of teeth, it is possible to make a conveyor which turns a corner. By using the method already described of incorporating rollers during manufacture it is possible to produce a "magic carpet" bend. To be geometrically precise each roller should take the form of a frustutn of a cone, but in practice, cylindrical rollers, which are easier to make, are satisfactory in operation.

There may be a tendency where, for example, for reasons of cost the pitch of the rollers is greater than a certain minimum valve, for objects carried on the conveyor to topple when passing from one roller to the next adjacent roller. This problem may be overcome by an arrangement such as is shown in Figure 6 of Figure 7. Referring to Figure, additional support members having a working surface disposed just beneath the surface of the conveyor are shown at 20.

Products moving along the conveyor normally will not be affected by these additional members 20, but should a product tend to rock or topple (this is more usual with the last one of the stack) the member will prevent the angle of displacement from the normal reaching a value at which the product falls over. The additional support members are linked at each end with adjacent wires to form the ladder and may be of any suitable form. They may, for example, be of wire form such as is shown in Figure 6a to raise the middle portion with respect to the ends or constructed as platforms 21 such as is shown in Figure 7. The platforms 21 would be attached to the ladder formed between adjacent rollers.

It will be appreciated that the above embodiment has been described by way of example only and that many variations are possible without departing from the scope of the invention. For example, although in the method described both ends of the wires are formed after threading on respective rollers, one end of each wire could be formed before threading on the corresponding roller and the other end formed after threading on.

As an alternative to the collars 14 and 15, push-on spring clips may be used. These clips essentially consist of a circle of spring steel having a central hole so shaped that when pushed onto the wire the metal adjacent to the wire is deformed and thereby grips the wire firmly, retaining the clip in the position to which it has been pushed.

Furthermore, although sprockets have been described on opposite sides respectively of the elements of the ladder, drive sprockets are necessary on only one side. Thus sprockets or plain rollers, free to rotate about a fixed axis, may be used on the other side or no sprockets or rollers provided on that side at all.

WHAT WE CLAIM IS: 1. A conveyor comprising a number of connected elongate elements each of which is formed at opposite axial ends for connection to an element adjacent it so that a flexible ladder-form chain of connected elements results, chosen ones of the elements so connected rotatably supporting rollers.

2. A conveyor as claimed in Claim 1, in which each element is made of wire.

3. A conveyor as claimed in Claim 2, in which the wire is of circular cross section.

4. A conveyor as claimed in Claim 2 or 3, in which the wire is heavy gauge, typically 4. 5 mm diameter.

5. A conveyor as claimed in any preceding claim, in which each element is U-shaped and the end of each arm of the 'U' is formed into a hook for attachment to the next adjacent element.

6. A conveyor as claimed in any preceding claim, in which sprockets are provided at opposite axial ends of the elements.

7. A conveyor as claimed in Claim 6, in which the sprockets at one end of the elements are of larger diameter than those at the other end.

8. A conveyor as claimed in any preceding claim, in which the rollers are disposed on every respective element.

9. A conveyor as claimed in any of claims 1 to 7, in which the rollers are disposed on every other element.

10. A conveyor as claimed in any preceding claim, in which each roller comprises a hollow tube closed at opposite axial ends by respective bushes, the bore or each bush providing a running clearance over the external diameter of the element supporting it.

Il. A conveyor as claimed in Claim 10, in which the tube and bushes are made of synthetic plastics material.

12. A conveyor as claimed in Claim 11, in which the material of the tube is Acrylonitrile Butadiene Styrene.

13. A conveyor as claimed in any preceding claim, in which means are disposed between at least one pair of adjacent rollers operative to inhibit toppling of objects passing over the rollers.

14. A conveyor as claimed in Claim 13, in which the means comprises a platform.

15. A conveyor substantially as hereinbefore described with reference to Figures 1-5 or to these figures with the modification of Figures 6 or 6a or Figure 7 of the accompanying drawings.

16. A method of making a flexible conveyor member including the steps of threading rollers onto selected ones of a plurality of elongate element to be freely rotatable, forming each axial end portion of each element such that it can be connected to the other elements, and connecting the elongate elements together by means of their end portions to form a flexible ladder-form chain of connected elements.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (16)

**WARNING** start of CLMS field may overlap end of DESC **. example only and that many variations are possible without departing from the scope of the invention. For example, although in the method described both ends of the wires are formed after threading on respective rollers, one end of each wire could be formed before threading on the corresponding roller and the other end formed after threading on. As an alternative to the collars 14 and 15, push-on spring clips may be used. These clips essentially consist of a circle of spring steel having a central hole so shaped that when pushed onto the wire the metal adjacent to the wire is deformed and thereby grips the wire firmly, retaining the clip in the position to which it has been pushed. Furthermore, although sprockets have been described on opposite sides respectively of the elements of the ladder, drive sprockets are necessary on only one side. Thus sprockets or plain rollers, free to rotate about a fixed axis, may be used on the other side or no sprockets or rollers provided on that side at all. WHAT WE CLAIM IS:

1. A conveyor comprising a number of connected elongate elements each of which is formed at opposite axial ends for connection to an element adjacent it so that a flexible ladder-form chain of connected elements results, chosen ones of the elements so connected rotatably supporting rollers.

2. A conveyor as claimed in Claim 1, in which each element is made of wire.

3. A conveyor as claimed in Claim 2, in which the wire is of circular cross section.

4. A conveyor as claimed in Claim 2 or 3, in which the wire is heavy gauge, typically 4. 5 mm diameter.

5. A conveyor as claimed in any preceding claim, in which each element is U-shaped and the end of each arm of the 'U' is formed into a hook for attachment to the next adjacent element.

6. A conveyor as claimed in any preceding claim, in which sprockets are provided at opposite axial ends of the elements.

7. A conveyor as claimed in Claim 6, in which the sprockets at one end of the elements are of larger diameter than those at the other end.

8. A conveyor as claimed in any preceding claim, in which the rollers are disposed on every respective element.

9. A conveyor as claimed in any of claims 1 to 7, in which the rollers are disposed on every other element.

10. A conveyor as claimed in any preceding claim, in which each roller comprises a hollow tube closed at opposite axial ends by respective bushes, the bore or each bush providing a running clearance over the external diameter of the element supporting it.

Il. A conveyor as claimed in Claim 10, in which the tube and bushes are made of synthetic plastics material.

12. A conveyor as claimed in Claim 11, in which the material of the tube is Acrylonitrile Butadiene Styrene.

13. A conveyor as claimed in any preceding claim, in which means are disposed between at least one pair of adjacent rollers operative to inhibit toppling of objects passing over the rollers.

14. A conveyor as claimed in Claim 13, in which the means comprises a platform.

15. A conveyor substantially as hereinbefore described with reference to Figures 1-5 or to these figures with the modification of Figures 6 or 6a or Figure 7 of the accompanying drawings.

16. A method of making a flexible conveyor member including the steps of threading rollers onto selected ones of a plurality of elongate element to be freely rotatable, forming each axial end portion of each element such that it can be connected to the other elements, and connecting the elongate elements together by means of their end portions to form a flexible ladder-form chain of connected elements.