GB2120617A

GB2120617A - Twin-rail runway systems

Info

Publication number: GB2120617A
Application number: GB08213244A
Authority: GB
Inventors: Arthur Henry Hodgkiss
Original assignee: LOCKERBIE AND WILKINSON
Current assignee: LOCKERBIE AND WILKINSON
Priority date: 1982-05-07
Filing date: 1982-05-07
Publication date: 1983-12-07

Abstract

To prevent metal-to-metal contact between a runner (4) of a twin-rail runway system and the rails (1, 2) thereof, non-metallic lift- restricting means (10) are mounted on the runner body (6) below the rails to engage the underside of the rails on excessive rocking of the runner body about the axis of running wheels (8). The means (10) can be of plastics or plastics covered metal, and may be in the form of a fixed or rotatable bar projecting from each side of the runner body (6), a collar around the body (6), or a projection or washer on a pin connecting hook (9) to the body (6). <IMAGE>

Description

SPECIFICATION Improvements in twin-rail runway systems This invention relates to twin-rail runway systems of the kind in which a pair of parallel rails are suspended from above in such wise that a plurality of runners, extending between the rails and rolling on the upper surfaces of the rails, can be moved freely along the rails. Systems of the above-described kind are widely used in the transportation of goods (in, for example, an abattoir or a cold store), the goods depending from a runner on an overhead arrangement of rails.

To provide adequate strength when heavilyloaded runners congregate over a short length of the rails, these are normally extruded from an aiuminium alloy. To provide adequate strength for the runners, these normally comprise a metallic body (e.g. die cast in aluminium alloy) provided with (a) bearing roller(s) (e.g. of plastics material) to run on the upper surfaces of the pair of rails and guide rolls (typically also of plastics material) which are located between the rails to prevent any sliding contact between the bodies of the runners and the rails. The goods are normally hooked onto the body of a runner, and a variety of different hooks can be provided, these normally being connected to the metallic body via a universal joint which results in a thickening of the body below the rails which is wider than the gap between the rails.

Runway systems of the kind described have been used with great effect for many years.

Recently, however, it has come to our attention that under certain extreme conditions of use, it is possible for metal-to-metal contact to occur between the underside of the rails and the body of the runner which results in unnecessary wear of the rails/body; undesired deceleration of, or resistance to movement of, the runner; the possible generation of metal particles and/or additional noise.

This undesired contact can occur in a transport vehicle fitted with the runway system or when a runner rocks about the axis of its upper bearing roller(s) on rapid acceleration/deceleration.

The present invention relates to an improved twin-rail runway system of the kind described and to an improved runner for use on such a system, which can avoid some or all of the aforesaid disadvantages of the prior art runners.

According to one aspect of the invention a twin-rail runway system comprises a pair of rails, means mounting the rails from above in parallel spaced-apart relative disposition, the upper surfaces of said rails defining coplanar running surfaces and the confronting faces of the rails defining a gap of uniform width, a plurality of runners each comprising a body portion extending through the said gap, at least one bearing roller resting on the upper surfaces of the rails, at least one guide roll located in the gap and a load support means disposed below the rails, and is characterised in that at least some of the runners have a non-metallic lift-restricting means disposed below the rails, which is incapable of passing through the gap and which is arranged to bear against the underside of the rails on sufficient rocking of the body portion about the axis of the bearing roller(s).

An improved runner which incorporates a liftrestricting means as defined above constitutes a further aspect of the invention.

The lift-restricting means can take many forms.

It can comprise a bar projecting outwardly from each side of the body portion below the rails (e.g.

parallel to the axis of the bearing roller(s)), rollers to engage the underside of the rails, washers on the end faces of the body portion or even a plastics coating on selected parts of the body portion below the rails.

Some examples of lift-restricting means are shown schematically in the accompanying drawings, in which: Figure 1 shows part of a twin-rail runway system according to the invention, and Figures 2 and 3 show scrap views of modified forms of runner for the system of Figure 1.

Referring to Figure 1, the system comprises pairs of metal rails 1 and 2 disposed within hangers 3 (only one shown) to make an overhead trackway on which runners 4 can be moved manually from below. The rails 1, 2 define coplanar running surfaces 1 a, 2a and confronting faces 1 b, 2b which define a gap 5. Each runner has a metallic body portion 6 supporting nonmetallic guide rolls 7 (which run in the gap 5) and a pair of non-metallic bearing rollers 8 which run on the surfaces 1 a, 2a.

Below the rails 1, 2, the runner mounts a loadbearing hook 9.

To prevent the aforesaid metal-to-metal contact, a pair of non-metallic lift-restricting members 10 are located below the rails 1, 2 projecting from opposite sides of the body portion 6 to provide a projection wider than the gap 5. The members 10 can be rotatably mounted on the body portion 6 or non-rotatably fixed thereto. They couid be a part (e.g. half) of a guide roll 17. They can be made of any suitable plastics material or could be plastics-coated metal-cored tubes. A stainless steel bolt 1 Oa is shown securing the members 10 in piace, and they can also be adhesively locked to the body portion 6 for improved strength.

Figure 2 shows two alternative forms of liftrestricting means. On the left of figure 2 part of the universal joint mounting the hook 9 comprises a plastics ball 11 which is too large to enter the gap 5 and on the right-hand side a non-metallic washer 12 is shown.

Figure 3 shows yet another form of liftrestricting means, this time in the form of a rectangular collar 13 of circular cross-section material clamped (by fixing means not shown) around the body portion 6 below the rails 1, 2 and dimensioned to ensure it is the collar 13 which contacts the underside of the rails on excessive swinging of the runner 4 about the axis of the rollers 8.

Other lift-restricting means can be employed to ensure the prevention of metal to metal contact as will be apparent to those skilled in the art. For heavy-duty applications, the arrangement shown in Figure 1 is preferred.

Claims

1. A twin-rail runway system comprises a pair of rails, means mounting the rails from above in parallel spaced-apart relative disposition, the upper surfaces of said rails defining coplanar running surfaces and the confronting faces of the rails defining a gap of uniform width, a plurality of runners each comprising a body portion extending through the said gap, at least one bearing roller resting on the upper surfaces of the rails, at least one guide roll located in the gap and a load support means disposed below the rails, and is characterised in that at least some of the runners have a non-metallic lift-restricting means disposed below the rails, which is incapable of passing through the gap and which is arranged to bear against the underside of the rails on sufficient rocking of the body portion about the axis of the bearing roller(s).

2. A runway system as claimed in claim 1, in which the lift-restricting means comprises a bar projecting outwardly from each side of the body portion below the rails.

3. A runway system as claimed in claim 2, in which each bar is of plastics material and is nonrotatably secured to the body portion.

4. A runway system as claimed in claim 1, in which each bar is of plastics material and is rotatably secured to lye body portion to define rollers engageable with the underside of the rails.

5. A runway system as claimed in claim 1, in which the lift-restricting means defines a projecting end of a pivot means mounting the load support means to the body portion.

6. A runway system as claimed in claim 1, in which the lift-restricting means comprises a collar secured around the body portion below the rails.

7. A runway system substantially as hereinbefore described with reference to, and as illustrated in, Figure 1 of the accompanying drawing, or Figure 1 as modified by Figure 2 or Figure 3 of the accompanying drawing.

8. A runner for a twin-rail runway system, which system comprises a pair of rails, means mounting the rails from above in parallel spacedapart relative disposition, the upper surfaces of said rails defining coplanar running surfaces and the confronting faces of the rails defining a gap of uniform width, said runner comprising a body portion extendable through the said gap, at least one bearing roller restable on the upper surfaces of the rails, at least one guide roll locatable in the gap and a load support means disposable below the rails when the bearing roller(s) rest(s) on the upper surfaces of the rails, characterised in that said runner has a non-metallic lift-restricting means which is incapable of passing through the gap and which is supported on the body portion in such wise as to bear against the underside of the rails on sufficient rocking of the body portion about the axis of the bearing roller(s).

9. A runner as claimed in claim 8, in which the lift-restricting means is defined by the plastics surface of a metal cored member.