NZ200789A - Overhead conveyor rail with low friction inserts on which skids travel - Google Patents

Description

200789 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION AFTER PROVISIONAL NO, 200789 DATED: 31 MAY 1982 CONVEYOR.RAIL WE, AICO MANUFACTURING ■' CO LIMITED, a New Zealand company of 22 Bell Avenue, Otahuhu, Auckland, New Zealand, do hereby declare the invention to be described in the following statement:- 200789 This invention relates to a conveyor rail, and has partic ular application to monorail conveyor systems in which a load is suspended from a skid or runner which slides or moves along the conveyor rail.

Such monorail conveyors have been used in handling loads in automatic warehouses, and in particular, in New Zealand, they find wide application in the handling of animal carcasses in meat works. Conventional conveyor rails are formed of steel, and metal skids are hooked over the top of the conveyor rail, and iloads are suspended from the skids. The skids slide along the top surface of the rail and this causes significant wear to the skidsand the rail. So much so, that in some cases, steel, filings and metal dust are deposited on the carcasses as the skids wear their way along the rail. This leads to the rejection of metal contaminated carcasses, and requires replacement of rails and skids.

It is an object of this invention to go someway towards overcoming the abovementioned disadvantage, in providing an improved conveyor rail, or a conveyor rail, which will at least provide operators with a useful choice.

In one aspect, the invention provides a conveyor rail including an elongate main member, having an upper surface and a strip of relatively abrasion resistant material on said upper surface to provide an upper bearing surface.

In a further aspect, the invention provides a conveyor rail including an elongate main member having a channel in an upper surface thereof, means for supporting said rail and a replaceable insert positioned in said channel and cov-ering at least a portion of said upper surface. 200789 In a yet further aspect, the invention provides a replaceable insert for the rail o£ the previous paragraph.

It is preferred that the insert is formed of a relatively low friction abrasion resistant material. As one example 5 of such material, we have found that high density polyethylene is particularly suitable for use as an insert or upper bearing surface on a conveyor rail.

In another aspect, the invention provides a method of reconditioning rails of the type described above, 10 ..v....... in which the insert is removed from said channel and a fresh insert placed in said channel and secured thereto.

Other aspects of this invention, which should be considered in all its novel aspects, will become apparent from 15 the following description, which is given by way of example only, with reference to the accompanying drawings, in which: Figure 1 illustrates a preferred rail in cross-section. Figure 2 illustrates a front elevation of the insert 20 receiving channel, with the insert removed.

A preferred rail 10 is in the form of a elongate member having an upper surface 11 and side faces 12, 13. 200789 Main face 12 is the skid bearing face and a skid (not $ shown) may be positioned with*the skid hanging over the top of the rail, with the main portion of the skid running down the face 12 of the rail.

An insert receiving channel 15 is provided on the upper face 11, and a similar insert receiving channel 16 is provided towards a lower portion of the main face 12.

Inserts 18 and 19 are capable of being positioned in these channels.

The inserts are preferably formed of a low friction material, preferably a plastics material. A preferred plastics material is high density polyethylene. This has been found to have a low co-efficient of friction, and a relatively high abrasion resistance. Other suitable plastics materials 15 include nylon. In addition to plastics materials, elasto-meric materials may be used, or composite plastics, e.g. "Thordon", or a metal such as brass. Nevertheless, we have found that UHM high density polyethylene is the preferred material as this is especially suitable for use in the food 20 industry.

The inserts are preferably shaped as shown in Figure 1.

That is to say, the upper insert 18 has a main body portion and sides 20 capable of covering the top of the rail. 2007 The lower insert 19 is preferably bevelled at 21 and is ' * of such a width as to cover the' opening of the channel 16.

It is preferred that the inserts are substantially T -shappd, that is to say they have a stem 22 which fits into the channels 15 and 16. It is preferred that the channels 15 and 16 are,serrated, or provided with teeth 25 on the side thereof to engage the stems 22, and prevent movement of the inserts along the length of the rails. By providing serrated sides to the channels, the inserts can be pushed or tapped directly into the channels and engaged therein in a simple and convenient manner. By utilising a plastics material, the material is gripped by the serrations 25 and in addition the material will tend to relax as shown by the darkened portion 30 of insert 18, i.e. it relaxes into the gaps between the serrations, and in addition the lower portion of the stem 22 relaxes into the widened portion of the channel 31. Thus the inserts may be readily inserted by tapping them into the channels or removed by levering than out df the channels.

In an alternative arrangement, the inserts can be provided with an enlarged foot at the base of thei s.tfem 22, and of a similar shape to the enlarged base 31 of the channel. With such T-shaped stems, the inserts can then be slid into, the channels from the end thereof, and slidgLlertg^the ^ 200789 channels until they cover the length of the rail. In such * an arrangement, the sides of-the channels 15 and 16 are preferably not serrated, otherwise the inserts could not be slid along the length of the channels. Such T - shaped 5 stems prevent the inserts from being removed bodily from the channels, as removal requires the inserts to be slid along the channels. It will be appreciated that this is not as convenient as the arrangement shown in Figures 1 and 2.

Whilst various combinations and materials can be utilised, the preferred combination is to utilise an extruded aluminium rail 10 in combination with a high density polyethylene material for the insert. This enables a lightweight but strong rail to be constructed for overhead conveyor systems, whilst minimising the creation of dust or metal filings which might otherwise contaminate foodstuffs below the rail or carried by skids on the rail. Rails can be connected together by appropriate connectors, or can be formed in long lengths, curved sections or the like.

The use of inserts such as high density polyethylene enables the inserts to bend to conform to the geometry of the rails. Thus several rails may be connected together, and a longer length of insert may pass along the rails bridging the gaps between the rails. 200789 The rails are preferably formed of extruded aluminium, formed in long lengths and can be provided with serrations as shown in Figure 2. Such aluminium rails, can be provided with the wear resistant inserts as shown, and can be connected to hangers or other supports, and thus provide a relatively cheap and durable conveyor rail, especially suited for meat works and the like.

The provision of a wear resistant insert, of the type previously described enables the rails to be readily reconditioned by removing an old insert and inserting a fresh insert, either by the reconditioning in situ, or by removing the rail sections and changing the insert in a workshop.

Finally, it will be appreciated that various alterations and modifications may be made to the foregoing without departing from the scope of this invention, as exemplified by the following claims. 2Q&78S

Claims (13)

WHAT WE CLAIM IS:

1. A conveyor rail including an elongate main member having an upper surface and a replaceable strip of relatively low friction material on said upper surface to provide an upper wearing surface.

2. A conveyor rail as claimed in Claim 1, wherein said strip of material protrudes above a longitudinal groove or channel in said upper surface.

3. A conveyor rail including an elongate main member having a channel in an upper surface thereof, means for supporting said rail, and a replaceable insert positioned in said channel and covering at least a portion of said upper surface.

4. A conveyor rail as claimed in Claim 3, and further including an additional replaceable insert positioned in a channel on the side of said rail with at least a portion of said additional insert protruding from said side channel.

5. A conveyor rail as claimed in Claim 3 or Claim 4 wherein said channel or channels is or are provided with gripping means to grip said replaceable insert or inserts.

6. A conveyor rail as claimed in Claim 5, wherein said gripping means consists of serrations on the sides of the channel or channels.

7. A conveyor rail as claimed in any one of Claims 3 to 6, wherein said replaceable insert or inserts is or are formed of a plastics material.

8. A conveyor rail as claimed in Claim 7, wherein said plastics material consists of high density polyethylene.

9. A conveyor rail as claimed in Claim 3 or Claim 4 wherein said channels are provided with an enlarged cavity and narrow jaws to hold a complementarily shaped replaceable insert in said channel or channels. N - 9 - &O0789

10. A conveyor rail as claimed in any one of the Claims 3 to 9, wherein said replaceable inserts have a cap section of greater dimension than the width of the channel in which said inserts are placed.

11. A replaceable insert for a conveyor rail of the type claimed in any preceding claim.

12. A method of reconditioning rails of the type claimed in any one of Claims 1 through 11, wherein an insert or inserts is or are removed from said channel or channels, and a fresh insert or inserts placed in said channel or channels and secured thereto.

13. A conveyor rail, or an insert for conveyor rails, substantially as herein described with reference to the accanpanying drawings. AICO MANUFACTURING 00 LIMITED By its Attorneys JAMES W PIPER & 00.