GB2323908A

GB2323908A - A drive chain assembly

Info

Publication number: GB2323908A
Application number: GB9701089A
Authority: GB
Inventors: Michael Charles Christmas
Original assignee: Renold PLC
Current assignee: Renold PLC
Priority date: 1997-01-24
Filing date: 1997-01-24
Publication date: 1998-10-07
Anticipated expiration: 2017-01-24
Also published as: GB2323908B; GB9701089D0

Abstract

A drive chain assembly comprises inner links 1 pivotally connected to outer links 2 by connecting pins 3. The outer links 2 each have a formation 5 engageable by complementary formations on drive means 7. When the drive means is operated the chain is moved in a rectilinear direction. The formation of each outer link may define a rack 6 that is engageable by a driving pinion. Alternatively there may be a formation on an upper or side face of the outer link engageable by a worm wheel. The outer links may be disconnected from one end and reassembled at the other. The in-line drive significantly reduces chain wear and improves accessibility for service and maintenance.

Description

A DRIVE CHAIN ASSEMBLY The present invention relates to a drive chain assembly.

In a conventional roller and bush chain individual links of the chain are generally interconnected by connecting pins to form a continuous chain loop. The links mesh with teeth of a rotary sprocket which generally provides the driving force to move the chain. As the chain engages the sprocket adjacent links pivot about the connecting pins to mesh effectively with the teeth. This pivoting movement occurs under load and therefore the chain links, their bearings and pins are subject to wear.

It is an object of the present invention to obviate or mitigate the aforesaid disadvantage.

According to the present invention there is provided a drive chain assembly comprising a chain having a plurality of links, adjacent links being interconnected by a pin, and drive means, wherein an outer portion of said chain has a formation engageable by a complementary formation of the drive means such that when the drive means is operated the chain is moved in a rectilinear direction.

Preferably the chain comprises a plurality of inner links each connected to an adjacent outer link by means of said pin, the said formation being provided on the outer link.

In a preferred embodiment the chain comprises a plurality of outer links that are releasably connected to a plurality of said pins.

Means may be provided to disconnect the outer links from one end of the chain assembly, to convey the separated chain components to the other end of the chain and to reassemble the chain at said other end.

There may be provided a quality inspection station at which the quality of the separated components of the chain are inspected.

Moreover, there may be provided a lubrication station where the components are lubricated prior to reassembly.

The formation of each outer link may define a rack that is engageable by a driving pinion. Alternatively there may be a formation on an upper or side face of the outer link which formation is engageable by a worm wheel.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is side elevation of a drive chain assembly according to the present invention; Figure 2 is a fragmented part-sectioned plan view of the chain shown in figure 1; Figure 3 is a sectioned view along line XX of figure 2; Figure 4 is a side elevation of a link of a first alternative embodiment of the present invention; Figure 5 is a part-sectioned end elevation of a second alternative embodiment of the present invention; Figure 6 is a part-sectioned plan view of a third alternative embodiment of the present invention; Figure 7 is a part-sectioned plan view of a fourth alternative embodiment of the present invention; Figure 8 is a part sectioned plan view of a fifth alternative embodiment of the present invention.

Referring now to the drawings, figures 1 to 3 show a drive chain having opposed pairs of inner link plates 1 that are connected to adjacent outer links 2 by means of connecting pins 3. Between each pair of inner link plates 1 there are two rotary roller bushes 4, one mounted coaxially on each connecting pin 3.

Each outer link 2 has two blind bores in which the ends of adjacent connecting pins 3 are pivotally received. The inner link plates 1 receive each connecting pin 3 in an interference fit in through bores provided.

As can be seen from figure 1 an upper surface 5 of the outer link 2 has a toothed formation defining a rack 6 that is designed to be engageable with a rotary pinion 7 driven by suitable drive means such as a motor and gear assembly 8 or the like. It will be seen that rotation of the pinion 7 causes rectilinear movement of the chain in the direction of the arrow shown in figure 1.

In alternative embodiments of the present invention the chain may be driven by a worm wheel 9 engaging the outer links 2 as shown in figures 4 to 6. In figure 4 the worm wheel 9 rotates about a fixed axis and is in engagement with a complementary formation defined on a side face 10 of the outer link 9 its rotation causing rectilinear movement of the chain. In figure 5 the worm wheel engages a complementary formation on the upper surface 5 of the outer link 2. The worm wheel 9 is shown in combination with a drive 11 in figure 6.

In the present invention central spaces 12 (see figure 2) between each inner link 1 and the roller bushes 4 are not required to engage with a sprocket and in applications where they are not employed for other purposes they can be eliminated as shown in figure 7. In this embodiment single inner link plates 1 are sandwiched between adjacent outer links 2 and are connected thereto by the connecting pins 3.

In the embodiment shown in figure 8 a length of chain is driven by toothed wheels 13 that engage formations on the exterior side faces of the outer links 2. The outer links 2 are separable from the connecting pins 3 by virtue of a slip fit or a suitable alternative releasable connection. This arrangement permits the dismantling of the chain once it leaves the working area. The separate components (the outer links 2 and an inner link assembly 1 a) can then be reassembled into a return drive chain (if there is one) or alternatively they are returned in the dismantled form to the beginning of the chain where they are reassembled into the drive train. The links la, 2 may be disassembled and reassembled by automated equipment (not shown) and the separate link components la, 2 may be conveyed to the other end of the chain by any suitable means. If the drive chain is inclined to the horizontal the link components la, 2 can be returned under gravity along suitable chutes or the like.

It will be immediately apparent that a chain assembly according to the latter embodiment will represent a significant saving in component cost by virtue of the elimination of the return length of chain. In addition a chain assembly of this type facilitates maintenance in that a lubrication station can be included to lubricate the link components on reassembly. Moreover an automatic quality inspection station could be provided so that worn or impaired link components la, 2 are automatically replaced. If desired the arrangement may be designed such that a completely new set of link components 1 a, 2 replace the existing links after a predetermined operation life of the chain.

By applying an in-line drive to the outer link the connecting pins 3 do not pivot under load and therefore there is virtually no wear between them and the bores in the outer links 2. The life of these components is therefore greatly increased.

Furthermore, the drive mechanism is more accessible and serviceable in view of its position relative to the chain. However it is to be understood that a chain of this design could also be used in a conventional continuous loop.

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, any type of suitable in-line drive is anticipated besides those examples described above.

Claims

1. A drive chain assembly comprising a chain having a plurality of links, adjacent links being pivotally interconnected by a pin, and drive means, wherein an outer portion of said chain has a formation engageable by a complementary formation of the drive means such that when the drive means is operated the chain is moved in a rectilinear direction.

2. A drive chain according to claim 1, wherein the chain comprises a plurality of inner links each connected to an adjacent outer link by means of said pin, the formation being provided on said outer link.

3. A drive chain according to claim 1 or 2, wherein the chain comprises a plurality of outer links that are releasably connected to a plurality of said pins.

4. A drive chain according to claim 3, wherein means are provided to disconnect the outer links from one end of the chain assembly and to reassemble the disconnected components of the chain at the other end of the chain assembly.

5. A drive chain assembly according to claim 4, wherein means are provided to convey disconnected chain components from one end of the chain assembly to the other.

6. A drive chain assembly according to claim 3 or 4, wherein there is provided a quality inspection station at which the quality of the separated components of the chain are inspected.

7. A drive chain assembly according to claim 3,4 or 5 wherein there is provided a lubrication station where the components are lubricated prior to reassembly.

8. A drive chain assembly according to any preceding claim, wherein the formation on the outer portion of the chain defines a rack that is engageable by a driving pinion.

9. A drive chain according to any one of claims 1 to 7, wherein the formation is on an upper or side face of the outer link, which formation is drivingly engageable by a worm wheel.

10 A drive chain substantially as hereinbefore described with reference to figures 1 to 3, or any one of figures 4 to 8 of the accompanying drawings.