GB2351543A

GB2351543A - A "snap-fit" chain

Info

Publication number: GB2351543A
Application number: GB0014629A
Authority: GB
Inventors: Michael Charles Christmas
Original assignee: Renold PLC
Current assignee: Renold PLC
Priority date: 1999-06-30
Filing date: 2000-06-16
Publication date: 2001-01-03
Also published as: GB0014629D0; DE10031898A1

Abstract

A chain comprises a plurality of inner 1 and outer 2 chain links connected by pins 7 to permit articulation of the links relative to one another. The pins 7 each have an annular undercut 6 adjacent each end. The outer link plates 2 have apertures 8a and 8b formed from overlapping holes of different diameters. Hole 8a allows the end portion of the pin 7 to pass therethrough and hole 8b is of a reduced diameter such that when the pin 7 is past hole 8a the pin can be moved laterally relative to the link to an assembled position where the undercut 6 is captively received in hole 8b. Resilient retaining elements 9 divide holes 8a and 8b, and serve to retain the pin 7 captively in the second portion 8b of the aperture in the assembled position. A load support member 10 may also be provided.

Description

2351543 A CHAIN The present invention relates to a chain and particularly,

but not exclusively, to a conveyor chain that has attachments for carrying or transporting objects.

It is known to construct conveyor chains with integral or separable load carrying attachments such as platforms or the like. Examples are shown in US Patent Nos. 5429226, 2955700, 3842968, UK Patent No. 8422-330 as well as our co-pending international patent application no. PCT/GB98/02108 (publication no. WO 99/03761). The attachments may be integrally formed -, vith outer links of the chain, permanently fixed to the outer link by means of bolts or the like or, alternatively, may be releasably secured to part of the chain by means of inter-engaging elements of the chain and the attachment.

It is an object of the present invention to provide for an improved connection between the component parts of a chain including an load carrying attachment of a conveyor chain.

According to the present invention there is provided a chain comprising a plurality of chain links interconnected by pins so as to permit articulation of the links relative to one another, the chain links comprising inner links and outer links, at least one pin having a first portion with a relatively large first diameter and an axially adjacent second portion with a reduced second diameter, at least one of the links having at least one aperture with a first portion having a diameter large enough to allow the end portion of the pin to pass therethrough and a second portion of reduced diameter such that when the first portion of the pin is passed through the first portion of the aperture the pin can be moved laterally relative to the link so that its second 2 portion is captively received in the second portion of the aperture, resilient retaining elements being defined between the first and second portions of the aperture and serving to retain the pin captively in the second portion of the aperture.

This arrangement provides for a simple interconnection and assembly of the component parts of a chain and since the first portion of the pin projects beyond the link it is available to support further attachments such as a load carrying member.

Preferably the first portion of the pin is defined at an end thereof The aperture is ideally defined in the outer link so that relative lateral movement of adjacent inner links relative to the outer link effects the captive retention of the pin or pins.

The outer link is preferably in the form of a plate.

The first and second portions of the aperture may be formed by intersecting circular apertures and the resilient elements may be defined at intersecting edges of the said circular apertures.

The aperture is preferably closed with respect to the periphery of the link in which it is formed so that insertion of the pin can only be in a direction substantially perpendicular to the plane of the link.

In a preferred embodiment an end of the pin extends laterally of the rest of the chain and carries a load support member.

The load support member may have a transport platform with a depending leg.

The leg of the load support member may have an aperture that resi liently engages said first portion of the pin and more preferably has a pair of apertures that are supported on pins of adjacent inner links.

3 The inner links may be formed of an integral moulding and the pin may be integrally formed with the respective inner link.

A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of an inner link member of a chain according to the present invention; Figure 2 is a perspective view of an outer link of a chain according to the present invention; Figure -3 is a perspective view of a load carrying member of a preferred embodiment of the present invention; Figure 4 is a perspective view of a chain comprising the assembled components of figures 1 to -3), shown with two load carrying members; Figure 5 is a perspective view of a chain according to claim 4 with one of the load carrying members removed; Figure 6 is a perspective view of an alternative embodiment of a chain in accordance with the present invention shown in a first configuration; and Figure 7 is the same view of the chain of figure 6 shown in a second configuration.

Referring now to the drawings, the exemplary chain has a plurality of articulated links 1, 2 that carry a plurality of load bearing attachments 3 to which a load to be conveyed or transported may be attached directly or indirectly.

The links 1, 2 comprise inner link members 1 one of which is shown in detail in figure 1 and outer link plates 2 one of which is shown in figure 2. Each inner link 4 member 1 is an integral plastics moulding having two parallel interconnected barrel shaped members 4 each supporting an integral or rotary pin 5.

Each pin 5 has an annular undercut 6 adjacent each end 7, the purpose of which will become clear later.

Each outer link plate 2 has a pair of apertures 8 that pass through the thickness of the plate but which are closed in the sense that they do not extend to the periphery of the plate 2. Each aperture 8 comprises two overlapping circular holes of differing diameters. In the embodiment shown a first hole 8a having a first diameter is positioned in-board of the end of the plate 2 and an overlapping hole 8b of slightly smaller second diameter is positioned so that it extends slightly outboard thereof. The first hole 8a is designed to be of a size to allow the end 7 of a pin 5 of the inner link member 1 to pass therethrough. The second hole 8b is designed to be of a diameter that is similar to the diameter of the annular undercut 6. At the intersection of the peripheries of the first and second holes 8a, 8b there are defined resilient retention elements 9 the purpose of which will be described below.

The chain is assembled by presenting an outer link 2 to a pair of adjacent inner link members 1 such that the apertures 8 are offered up to adjacent pins 5 of the neighbouring inner link members 1 with that the longitudinal axes of the pins 5 substantially perpendicular to the plane of the outer link plate 2. The ends 7 of the pins 5 are then passed through the first hole until the outer link plate 2 is coplanar with the annular undercuts 6. At this point the adjacent inner link members 1 are moved laterally apart so that the annular undercuts 6 engage the resilient elements 9. Further movement of the inner link members 1 causes the resilient elements 9 to deflect and allow passage of the pins 5 into coaxial alignment with the second hole 8b. The resilient elements 9 return to their equilibrium position and serve to retain the annular undercuts 6 and therefore pins 5 in position in a form of snap-fit engagement.

Once assembled in the manner described above the ends 7 of the pins 5 project laterally from the chain and serve to support load bearing attachments 3 as shown in figures 4 and 5. Each load bearing attachment 3 has an upper planar platform 10 on which loads may be directly or indirectly supported via other attachments (not shown). Apertures 11 are provided in the upper platform 10 for the purpose of attaching the load or additional load supporting elements. Depending from each platform is a plate-shaped leg 12 having two apertures 13 that are designed to engage with the projecting pin ends 7 of adjacent inner link members 1. Each platform 10 has resilient formations 14 that are designed to resiliently engage with at least pan of the outer link plate 2, as it is known in the art. The apertures 13 in the legs 12 are of such a diameter as to form a resilient interference fit with the pin ends 7 and are thus supported by the pins 7 by virtue of frictional engagement.

The load bearing attachments 3 may be arranged on the chain in any desired configuration. The arrangement shown in figure 4 illustrates a chain with load bearing attachments ') disposed on both sides of the chain whereas the arrangement of figure 5 shows an attachment 3 3 on one side only.

In use, the annular undercuts 6 provide a bearing surface for the articulating movements of the outer link plate 2.

The chain arrangement provides for case of assembly and permits the simple addition of load bearing attachments.

6 In an alternative chain embodiment shown in figures 6 and 7 the outer link plate 102 has a supplementary link plate 102a hinged thereto along a top edge. The plates 102, 102a are made of plastics material and a thin web of plastics material joining the two forms a hinge 120.

The supplementary link plate 102a is coterminous with the outer link plate 103 but has two apertures 121 that are each designed to be a tight fit with the end 107 of a respective pin 105. In the embodiment shown in figure 6 the supplementary link plate 102 is fitted over the ends of the pins 105 and provides additional strength to the chain. A clip 122 integral with the supplementary link plate 102a hooks over the outer link plate 102 to hold in this configuration.

In order to disconnect the outer link plate 102 the supplementary link plate 102a is first unclipped and then hinged upwardly to the position shown in figure 7. This arrangement provides for easy assembly and disassembly without compromising the strength of the chain. The supplementary link plate 102a may carry a load supporting platform, if desired or the platform may still be attached as depicted in figures 4 and 5.

It will be appreciated that numerous modifications to the above described design may be made without departing from the scope of the invention as defined in the appended claims. For example, the chain components and load bearing attachment may be of an appropriate shape besides those shown in the appended drawings. Moreover, the configuration of the engagement of the pins and links may be reversed such that the undercut pins engage with apertures in the inner link members.

7 Finally, it is to be understood that the load supporting platform may be formed integrally or separably with the. outer link plate.

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Claims

A chain comprising a plurality of chain links interconnected by pins so as to permit articulation of the links relative to one another, the chain links comprising inner links and outer links, at least one pin having a first portion with a relatively large first diameter and an axially adjacent second portion with a reduced second diameter, at least one of the links having at least one aperture with a first portion having a diameter large enough to allow the end portion of the pin to pass therethrough and a second portion of reduced diameter such that when the first portion of the pin is passed through the first portion of the aperture the pin can be moved laterally relative to the link to an assembled position in which the second portion of the pin is captively received in the second portion of the aperture, resilient retaining elements being defined between the first and second portions of the aperture and serving to retain the pin captively in the second portion of the aperture in the assembled position.
2. A chain according to claim 1, wherein the first portion of the pin is defined at an end thereof.
3. A chain according to claim 1 or 2, wherein said at least one aperture is formed in the outer link.

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4. A chain according to any one of claims 1 to 3, wherein the first and second portions of said at least one aperture are formed by intersecting circular apertures.
5. A chain according to claim 4, wherein, the resilient elements are defined at intersecting edges of said intersecting circular apertures.
6. A chain according to any preceding claim, wherein the at least one aperture is closed with respect to the periphery of the link in which it is forrned.
7. A chain according to any preceding claim wherein an end of the pin extends laterally of the rest of the chain and carries a load support member.
8. A chain according to claim 7, wherein the load support member has a transport platform with depending leg.
9. A chain according to claim 8, wherein the leg of the load support member has an aperture with a periphery that engages said first portion of the pin.
10. A chain according to claim 9, wherein the aperture periphery is an interference fit or resilient engagement with the first portion of the pin.
11. A chain according to claim 10, wherein the load support member has a pair of apertures that are supported on pins of adjacent inner links.
12. A chain according to any preceding claim, wherein the inner links are formed of an integral moulding.
1 A chain according to claim 12, wherein said at least one pin is integrally formed with the respective inner link.
A chain according to any one of claims 1 to 13, wherein the outer link has a supplementary link hinged thereto.
15. A chain according to claim 14, wherein the supplementary link has a clip for securement to the outer link.
16. A chain according to claim 14 or 15, wherein the supplementary link is hingedly moveable between a first position in which it lies coterminous with the outer link and is engaged to said at least one pin and a second position in which it is clear of the pin and outer link.
17. A chain substantially as hereinbefore described with reference to the accompanying drawings.

1 C.