GB2111928A - Load supporting carrier adapted to run on an overhead track - Google Patents

Abstract

The carrier e.g. for a poultry carcase comprises two members 3, 4 of plastics material. The members each comprise an arm 5 and a body portion 6. The arms 5 are provided with rollers 8 which bear upon the rail. To give the arms sufficient strength to resist lateral forces, the two members 3, 4 are clamped together to form the carrier by a long bolt 13 passing through both the arms so as to act as a beam reinforcing said arms. <IMAGE>

Description

SPECIFICATION Load supporting carrier adapted to run on an overhead track The invention relates to a load-supporting carrier adapted for use with an overhead track along which it runs while carrying a load.

Load-supporting carriers are widely used in factories and other locations for moving loads along predetermined paths by suspending the load by means of a carrier which travels along an overhead track, e.g. an I-section rail or a tubular rail. One example is a carrier to carry a poultry carcase through a processing plant, during which a variety of loads are applied to the carrier as different operations are performed on the carcase.

One carrier much used in the past has generally consisted of a shank or body to which the load is attached and two arms projecting upwardly from the body, which arms lie on either side of the track. The ends of the arms are each provided with a roller or wheel which bears upon an upper surface of the rail, so that the carrier is suspended from and may easily run along the rail. The carriers, for ease of construction, comprise two members each having an arm and a part of the main body. The two members in the past have been clamped together by short bolts passing through the main body portions. UK patent specification 1,201,524 illustrates this type of carrier.

However, the construction of such carriers and the stresses to which they are subjected in use have meant that metal, in particular steel, is the only material strong enough to be used to make the carriers. Steel however is nowadays considered both an expensive raw material and expensive and difficult to work.

The use of plastics material would be cheaper and easier but hitherto has been impossible as the resulting carriers are not strong enough.

In particular when a rail of circular cross section is used to support carriers which have wheels bearing on an upper portion of its surface the lateral forces forcing the arms of the carrier apart can be very great, in addition to the other forces acting on the carrier. The same is true, to a lesser extent when the track is an I-beam since the surfaces on which the wheels run slope outwardly. In either case the lateral forces lead to fracture of the arms, if the carrier is made of plastics material.

An object of the invention is therefore to provide a load supporting carrier for use on an overhead track, which may be made largely of plastics material and yet is designed to have adequate strength of the arms against fracture in normal use.

According to the present invention in one aspect the load-supporting carrier has a tensioned bolt passing through both the arms which project upwardly to embrace the track, so that the bolt acts as a beam reinforcing said arms.

The bolt, which is typically made of steel, preferably has a tensioned length which is greater than the spacing of the rear (outside) faces of the rollers of the carrier at the centres of those faces (i.e. at the axes of rotation of the rollers).

In another aspect the tensioned length of the bolt is greater than the widest spacing between the inside faces of the arms between the bifurcation of the arms and the rollers.

Preferably the arms each have at least one outwardly directed reinforcing flange extending from the mounting location of the roller to the location of the bolt in the arm.

The present invention can provide a carrier having a very strong construction. The construction is such that the carriers may be made from plastics material and yet be strong enough to withstand the stresses of use.

When made of plastics material the carriers can be considerably lighter and cheaper than metal ones and make it easier for operations to attach loads to them and place them on an overhead rail or to move them along a rail. On a large production line where many carriers are being moved around automatically, moving plastics material carriers can require less energy than moving metal ones.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which Figure 1 is an end view of a first carrier embodying the present invention on a tubular overhead rail which is shown in cross section; Figure 2 is a similar end view of a second carrier embodying the invention, suitable for an I-section overhead rail, which is likewise shown in section; and Figure 3 is a side view of the carrier of Fig.

2, with the rollers and the overhead rail not being shown.

The carrier 1 embodying the present invention shown in Fig. 1 is mounted on an overhead track in the form of a rail 2 which is a tube of circular cross-section which supports the carrier. The carrier comprises two identical members 3, 4 which each comprise an arm 5 and a body portion 6, the arm 5 being joined at its lower end 7 to the body portion 6. The two members 3, 4 in this embodiment are moulded of a 25% glass fibre filled plastics material known as Kemetal (Trade Mark of Amsel). Any other suitable plastics material may be employed.

The arms 5 of the members each carry a roller 8 at their upper ends. The rollers may be of any suitable material, for example of plastics material. The rollers 8 are secured to the arms 5 by nuts and bolts 9 which pass through bosses 9a on each arm and act as axles on which the rollers 8 are mounted on ball bearings, in a conventional manner. The rollers are positioned at the ends of the arms so as to bear on the upper surface of the rail 1. If the rail is circular in cross-section as in the case in the embodiment shown the rollers are mounted with their centre planes disposed radially about the rail so that they bear on an upper side portion of its surface. The upper parts 7a of the arms 5, which extend upward vertically are spaced apart sufficiently to accommodate the rail 2 between them.Preferably they are close enough to the rail 2 to help prevent inadvertent derailment of the carrier by sideways blows.

The body portions 6 of the members 3, 4 together form a body to which a load may be attached by means of a bolt 10 passing through a notch 11 formed in the lowermost part of the body. By contouring 6a of the opposing faces of the body portions 6 provision is made for them to grip a chain passing between them. This enables the carriers to be moved along automatically by attaching them to a power driven chain. Alternatively the opposing faces of the body portions 6 may be contoured to grip ropes or other suitable drive means.

The members 3, 4 are clamped together to form the carrier by means of a short bolt 1 2 which passes through the body portions 6 and by a long bolt 1 3 which extends through the lower portions 7 of the arms 5. These lower portions 7 extend outwardly as well as upwardly away from the zone of bifurcation of the arms. The members 3, 4 may be clamped together directly or have a spacer between them if required. The long bolt 1 3 not only helps clamp the members 3, 4 together but acts as a supporting beam which reinforces the arms 5 and from which the main body portions 6 are dependent.The provision of the long supporting bolt 1 3 in the lower portions of the arms 5 rather than having two clamping bolts passing through the body portions 6 (as has been the practice in carriers made of steel) results in a very strong construction. Further similar short or long bolts may be used if desired.

The arms 5 have a T-beam section, composed of flanges 5a and 5b respectively constituting the cross-bar and the stem of the T.

The whole tensioned length of the bolt 1 3 is housed in a bore which passes through both flanges 5a, 5b of each arm, just above the junction with the body 6. The flanges 5b have thickened portions Sc to accommodate this bore. The height of the flanges 5a increases from the bosses 9a to the thickened portions 5c.

The nuts and bolts used in the carrier may be of any suitable material and are preferably steel bolts.

It will be appreciated that the long bolt 1 3 is well placed to resist lateral forces resulting from the contact of the rollers and the tubular rail. Such lateral forces tend to push the arms apart.

In this embodiment the tensioned length of the bolt is about 9 cm. In general, this length is preferably at least 5 cm, more preferably at least 7 cm. The tensioned length is greater than the spacing between the upper parts 7a of the arms 5 at the level of the widest part of the tubular rail 2, and is also greater than the spacing of the points of intersection of the respective axes of the rollers 8 with the rear (outside) faces 8a of the rollers.

The carrier of Fig. 2 is designed to run on the upper faces of the lower flange 21 of an Ibeam track 20, and has a pair of wheels or rollers 22 on a common axis which engage this flange. As Fig. 2 shows, the surfaces engaged by the rollers 22 slope outwardly, so that some lateral thrust is applied to the rollers in operation. The upper flange 23 helps to trap the rollers 22, in order to prevent derailment.

Like the carrier of Fig. 1, the carrier of Fig.

2 has a body or shank 24 and arms 25 consisting of outwardly extending portions 26 and upwardly extending portions 27, the lateral carrying the respective rollers 22 by means of bolts (not shown) through apertures 28. The body 24 and arms 25 are made of two identical glass-fibre reinforced plastics material parts 29 whose respective body portions 30 are slightly spaced in the assembled condition to provide a slot 31 which receives a plate (not shown) from which the load is suspended. Short bolts (not shown) pass through holes 32 and 33 to hold the body portions together and secure this plate in position. Through a hole 35a in the outwardly extending portions 26 of the arms, a long bolt 34 extends secured by a nut 35 with its tensioned length equal to the length of the hole 35a.This bolt 34 corresponds to the bolt 1 3 of Fig. 1 and provides the same functions and advantages. Its tensioned length is greater than the maximum spacing between the respective inner faces 36 of the arms 25 and greater than the spacing between the outer faces 37 of the rollers 22.

The parts 29 are moulded with a number of integral flanges on their outward-facing surfaces, to provide strength. An annular flange 38 surrounds the bolt apertures 28, and from it three flanges 39, 40, 41 extend to the region at the end of the bolt hole 35 where cross-flanges 42 join them, the two outer flanges 40, 41 extending further into the body portion 30 and terminating at a cross flange 43. At the lower end of the body portion 30 a flange 44 partly surrounds the bolt hole 33.

The term "bolt" is used broadly in this specification, including the claims, and covers any suitable tension means for securing together the carrier parts and acting as a beam as discussed above.

Claims (10)

1. A load supporting carrier adapted to run on an overhead track, comprising two members moulded of plastics material and each comprising an arm and part of a body, said arms projecting outwardly and upwardly from said body and each being provided with a roller supporting said carrier on an overhead track on either side of which said arms are positioned in use and said members being clamped together so as to form said body and said arms by means comprising a bolt passing through outwardly projecting portions of both said arms so as to act as a beam reinforcing said arms.

2. A carrier according to claim 1 wherein said bolt has a length under tension which is at least as great as the maximum spacing between the respective inner faces of said arms.

3. A carrier according to claim 1 or claim 2 wherein said rollers are, in use, positioned with their rotational axes respectively oppositely inclined to the horizontal.

4. A carrier according to any one of claims 1, 2 and 3 wherein the tensioned length of said bolt is at least 7 cm.

5. A carrier according to any one of the preceding claims wherein each said arm has at least one flange projecting outwardly and extending from the region adjacent the roller to the region adjacent the bolt.

6. A load supporting carrier adapted to run on an overhead track, comprising two members moulded of plastics material and each comprising an arm and part of a body, said arms projecting outwardly and upwardly from said body and each being provided with a roller supporting said carrier on an overhead track on either side of which said arms are positioned in use and said members being clamped together so as to form said body and said arms by means comprising a bolt which is arranged and adapted to act as a beam reinforcing said arms and has a tensioned length which is greater than the maximum spacing between the respective inside faces of said arms.

7. A load supporting carrier adapted to run on an overhead track, comprising two members moulded of plastics material and each comprising an arm and part of a body, said arms projecting outwardly and upwardly from said body and teach being provided with a roller supporting said carrier on an overhead track on either side of which arms are positioned in use and said members being clamped together so as to form said body and said arms by means comprising a bolt which is arranged and adapted to act as a beam reinforcing said arms and has a tensioned length which is greater than the spacing of the points of intersection of the respective rotational axes of the rollers with the respective outer faces of the rollers.

8. A load supporting carrier substantially as herein described with reference to and as shown in Fig. 1 of the accompanying drawings.

9. A load supporting carrier substantially as herein described with reference to and as shown in Fig. 2 of the accompanying drawings.

10. An overhead track system having an overhead track and a plurality of carriers according to any one of the preceding claims.