GB2237255A

GB2237255A - Conveyor web or flexible ladder

Info

Publication number: GB2237255A
Application number: GB8922720A
Authority: GB
Inventors: Douglas Charles Mcrae
Original assignee: NAT RES DEV; National Research Development Corp UK
Current assignee: NAT RES DEV; National Research Development Corp UK
Priority date: 1989-10-09
Filing date: 1989-10-09
Publication date: 1991-05-01
Also published as: GB8922720D0

Abstract

A conveyor web comprises transverse bars 10 supported in location holes 12 accommodated within the thickness of drive bolts 14. Fibre reinforcement is provided at 20 and 22 to support the bars 12 and to increase the traction strength of the construction. The construction may be used as a flexible ladder for use with, for example, helicopters. <IMAGE>

Description

CONVEYOR WEB The present invention relates to conveyor webs i.e. to constructions comprising a plurality of laterally spaced bars of any convenient cross-section secured between two drive belts. In particular, but not exclusively, the invention relates to conveyor webs for use in agricultural machinery.

With conventional designs of agricultural conveyor web, the bars are secured in place against a plane face of the drive belts by rivets. The other face of the belts is formed with drive teeth and the bar-securing rivets are backed by abutment plates located in the inter-teeth gaps.

The principal disadvantages of these conventional designs are, first, that the rivetting process tends to result in damage to the plate-engaging parts of the belts and, secondly, that the plates give the construction an unwelcome stiffness which will increase the power required to drive the conveyor web.

It is an object of the present invention to provide a conveyor web in which these disadvantages are significantly reduced or substantially avoided.

According to one aspect of the present invention, in a conveyor web (as above defined) the bars are supported in location holes accommodated within the. thickness of the drive belts.

Conveniently, the drive belts are formed with transverse ribs and the location holes are, at least in part, accommodated within these ribs.

In one such case, for example, where the belts are made of rubber or similar elastomeric material, the hole reinforcement fibres will be of Kevlar (Trade Name) or other material of similar Young's Modulus.

Conveniently, the drive belts are formed with traction reinforcement fibres of a similar order of resilience to the material of the belts and adapted to carry the traction forces imposed on the conveyor web during use.

In one such case, for example, where the belts are made of rubber or similar elastomeric material, the traction reinforcement fibres will be of nylon or other material of similar Young's Modulus.

Where both hole reinforcement and traction reinforcement fibres are present, then conveniently the bars are sandwiched between hole reinforcement fibres adjacent or bounding (e.g.

circumferentially) one side of the hole, and traction reinforcement fibres adjacent or bounding (e.g. tangentially) the other side of the hole.

In all cases, rather than rely on a push fit in the location holes, some additional means may be provided for discouraging longitudinal movement of the bars in the location holes, for example a click-fit protrusion on the bar or a locking grub screw, rivet or other like device extending through the thickness of the belt to engage the bar. As a further alternative, an adhesive might be used.

It should also be appreciated that substantially the same construction as the conveyor web of the present Invention, may have applications in other than the conveying field e.g. as a flexible ladder for use with a helicopter etc. and the scope of the invention is to be interpreted as including the same or like constructions intended for this and other purposes.

According to another aspect, the invention also includes a drive belt for use in the conveyor webs and like constructions of the present invention.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying somewhat diagrammatic drawing which shows, in perspective, a scrap view of part of a particular design of conveyor web in accordance with the present invention.

Thus referring now to the drawing, a conveyor web in accordance with the present invention comprises a plurality of hollow cylindrical metal bars 10 supported in location holes 12 accommodated within the thickness of two laterally-spaced drive belts of which only the nearer one (belt 14) is shown in the drawing. In the case of the wide webs found on two-row potato/root crop harvesters, a centre web belt of the same construction may also be used.

As will be apparent from the drawing, each belt comprises drive teeth 16 (the drawing shows the lower run of the belt) and transverse ribs 18 in which the location holes 12 are partly accommodated.

The rubber or other elastomeric material of the belts is provided with a layer of hole reinforcement fibres 20 of Kevlar or other fibres of similarly high Young's Modulus (low resilience) compared to the belt material. In addition, the belt is reinforced by a centrally located layer of traction reinforcement fibres 22 of Nylon or other material of similar Young's Modulus.

The bars 10 are held against longitudinal movement in the holes 12 by a click-fit protrusion 24 or by a rivet (not shown) passing through the rubber of the belt to engage the bar.

In a typical case, with the materials discussed above, the width of the belt (measured parallel to the bar axes) might be 60 mm and the depth of the ribs (measured from the mid-plane of the construction occupied by fibres 22) might be about 18 mm to accommodate a bar 10 of outside diameter 12 mm, say.

The conveyor web construction illustrated in the drawing will preferably be sufficiently resilient to negotiate a roller of minimum radius 45 mm, say, while at the same time providing a breaking strain in the region of 6000-7200 Kg. With its relatively low-power drive requirements, impressive strength and mechanically robust substantially trouble-free construction, this preferred form of conveyor web provides an attractive alternative to the conventional designs of conveyor web currently available.

Claims

1. A conveyor web comprising a plurality of laterally spaced bars secured between two drive belts, in which the bars are supported within the thickness of the drive belts.

2. A conveyor web as claimed in Claim 1 in which the drive belts are formed with transverse ribs and the location holes are, at least in part, accommodated within these ribs.

3. A conveyor web as claimed in Claim 2 in which the location holes are at least in part provided with hole reinforcement fibres.

4. A conveyor we as claimed in Claim 3 in which the belts are made of rubber or similar elastomeric material and the hole reinforcement fibres are of Kevlar (Trade Name) or other material of similar Young's Modulus.

5. A conveyor web as claimed in any preceding claim in which the drive belts are formed with traction reinforcement fibres of a similar order of resilience to the material of the belts and adapted to carry the traction forces imposed on the conveyor web during use.

6. A conveyor web as claimed in Claim 5 in which the belts are made of rubber or similar elastomeric material and the traction reinforcement fibres are of nylon or other material of similar Young's Modulus.

7. A conveyor web as claimed in Claim 5 or Claim 6 when including the limitations of Claim 3 or Claim 4 in which the bars are sandwiched between hole reinforcement fibres adjacent or bounding one side of the hole and traction reinforcement fibres adjacent or bounding the other side of the hole.

8. A conveyor web as claimed In Claim 7 in which the hole reinforcement fibres bound said one side of hole circumferential ly.

9. A conveyor web as claimed in Claim 7 or Claim 8 in which the traction reinforcement fibres bound said other side of the hole tangentially.

10. A conveyor web as claimed in any preceding claim including attachment means for discouraging longitudinal movement of the bars in the location holes.

11. A conveyor web as claimed in Claim 10 in which the attachment means comprises a click-fit protrusion on the bar and/or a locking grub screw, rivet or other like device extending through the thickness of the belt to engage the outer wall of the bar, or an adhesive.

12. A construction having the characteristics of the conveyor web as claimed In any preceding claim and adapted for use in other than the conveying field e.g. as a flexible ladder for use with a helicopter etc.

13. A drive belt for use in a conveyor or like construction as claimed in any preceding claim.

14. A conveyor web or like construction or a drive belt therefor substantially as hereinbefore described with reference to, andlor as illustrated in, the accompanying drawing.