AU702341B2 - Conveyor chain and drive assembly - Google Patents

Description

.1r~ 45572 DP:MG P/00/009 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

0e a a i Name of Applicant: SEKWAH PTY LTD Trading as AUSTVEYORS (SA) Name of inventors: KEITH DYER LEONARD HAWKES Address for Service: COLLISON CO., 117 King William Street, Adelaide, S.A. 5000 Invention Title: CONVEYOR CHAIN AND DRIVE ASSEMBLY Details of Associated Provisional Applications: PN4604 Dated 4th August 1995 The following statement is a full description of this invention, including the best method of performing it known to us: 0, 0

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BACKGR(

~~OIVf THE INVENTION nt invention relates to a conveyor chain and a drive assembly for he conveyor chain. In particular, the conveyor chain and conveyor mbly of the present invention find use in the high speed handling of Id other packages.

)UND OF THE INVENTION

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o ooeo ftfe ee.oo o o o ooo oaoo ea~ During the sorting of parcel items, for example by postal service agencies, it is necessary for the various parcel items to be transported over a distribution network throughout. To ensure the rapid sorting that is required for timely mail 1 0 delivery it is important that movement of the parcel items is carried out at the highest possible speed, and to this end, a mechanical conveyor is typically used for the transport process. However the sorting of mail and parcels also involves a human input and it is desirable that any mechanical conveyors used in the transport process operate within tolerable noise levels. Clearly, it 1 5 is preferable that the noise produced from any conveyor is in fact at a minimum. Generally, in the operation of mechanical conveyors the noise generated during the use of the conveyor increases with increasing speed of the conveyor. Thus as conveyor speed increases the comfort levels of personnel close to the conveyor are decreased.

The present invention is directed towards the resolution of the conflicting requirements of high speed and low noise level. It is an object of the present invention therefore to provide a conveyor for use with parcels and packages which can be operated at considerable speeds without generating unacceptable noise levels.

BRIEF STATEMENT OF THE INVENTION According to a first aspect of the present invention there is provided a conveyor comprising a conveyor drive assembly comprising: means operable to drive a drive chain; the drive chain having a plurality of pusher rolls located thereon at A4 'C11~ I1~CQ"9LI ILI 3 spaced intervals, the pusher rolls having an outer coating of plastics material; a conveyor chain assembly comprising a plurality of interconnected link elements each link element being connected to adjacent link elements by a bearing member; the plurality of pusher rolls being adapted to bear against the bearing members of the conveyor chain such that in use, movement of the drive chain is transferred to the conveyor chain by the plurality of pusher rolls bearing against bearing members thereby driving the conveyor chain.

The conveyor assembly of the present invention is therefore driven by the 1 0 movement of the pusher rolls of the drive chain creating a corresponding movement in the conveyor chain as a result of the interaction of the pusher Lt rolls acting on the bearirig of the conveyor chain. The coating or manufacturer of each of the separate eiaments of a plastics material ensures that the conveyor track can operate at high speed whilst having a low noise emission.

1 5 Typically in an overhead conveyor arrangement the conveyor of the present invention is able to operate at a speed of approximately Preferably, the bearing is a urethane coated bearing.

Preferably, the conveyor chain is formed on link elements adapted for bidirectional travel, the link elements being interconnected by the bearing member in the form of a cruciform casting having a number of separate bearing elements mounted thereon. The bearing member is therefore 0 conveniently comprised of first and second pairs of opposed bearing elements, the bearing elements being arranged on two opposed axes of the cruciform casting, thereby allowing the links to swivel on two axes.

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Preferably, the bearing elements are a press fit onto the casting. In this manner, the bearing element and cruciform casting interact in a manner which is consistent with the high speed performance required of the conveyor and the low noise emission requirements of the conveyor.

Preferably, the drive assembly includes a caterpillar chain formed of a hollow 3 0 pin chain having pusher rolls formed of a ciystalline formaldehyde resin (for 4 example the resin currently sold under the trade mark DELRIN), the pusher rolls being adapted to bear against the bearings of the conveyor chain such that the conveyor chain is able to be moved at high speed in response to movement of the pusher wheels over the chain.

Preferably, the caterpillar chains run in pairs on sprockets fabricated to suit the caterpillar chain, the sprocket and chain interaction from being so fabricated as to be silent in use. Also, to further reduce any noise emanating from the conveyor assembly, the assembly further includes a drive base on housing to encase the mechanism and therefore reduce any noise extending from the mechanism.

Therefore, the invention includes a conveyor including a caterpillar chain and a conveyor chain, the caterpillar chain being driven by a motor and in turn driving the conveyor chain by a pushing and rolling action on the outer rim of the bearings of the conveyor chain. The pushing and rolling action is 1 5 essentially a low noise smooth action allowing the conveyor chain and caterpillar chain to be engaged and disengaged in a low noise fashion.

BRIEF DESCRIPTION OF THE DRAWINGS 0 0 r 4 9909 o:0o00 The present invention will now be described, by way of example only, with o099: reference to the accompanying illustrations in which: 06 0. 20 FIG 1 illustrates in perspective view a conveyor assembly including a chain assembly and drive mechanism in accordance with one aspect of the present invention; 09 0 FIG 2 illustrates in detail a perspective view of the caterpillar chain and conveyor chain; FIG 3 illustrates a cross sectional view the caterpillar chain of the conveyor of FIG 1 drawn on the line 4-4 shown on FIG 2; FIG 4 illustrates in cross sectional view the caterpillar chain of FIG 2 and the interaction between the caterpillar chain and the conveyor chain; FIG 5 shows a side view of a detail of the conveyor chain assembly; and FIG 6 illustrates in plan view the bearing member of the conveyor chain assembly of FIG 5; and FIG 7 illustrates in perspective view the central body of the bearing of FIG DESCRIPTION OF THE PREFERRED EMBODIMENT Shown in FIGS 1 and 2 is a conveyor chain assembly 10 in accordance with the present invention. The chain assembly 10 includes a drive mechanism in the form of a drive motor 12 and associated drive shaft 14. The drive shaft 14 is connected to a transmission chain 16 via a pulley 18 located on the drive shaft 14.

The transmission chain 16 in turn controls a driven shaft 20 via a pulley 22 located on the shaft 20. Also mounted on the driven shaft 20 are a pair of axially spaced driven sprocket wheels 24. Each driven sprocket wheel 24 has an associated idler wheel 26 spaced therefrom.

1 5 A drive chain in the form of a caterpillar chain 28 extends around each associated driven sprocket wheel 24 and idler sprocket wheel 26. The caterpillar chain 28 can be seen in FIG 1 and in a cross sectional view in FIG 3. In FIG 3 the detail of the conveyor chain has been omitted for purposes of clarity.

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Each caterpillar chain 28 comprises a plurality of spaced opposed paired sections each connected in a chain by hollow pins 30 on a 2 inch pitch. At intervals along the length of the caterpillar chains 28 are located pusher rolls 32. The pusher rolls 32 are centred on the pins 30 which serve as an axle for the pusher rolls 32. The pusher rolls 32 are located inwardly of the opposed oo0 25 paired sections.

o The caterpillar chain 28 includes a two inch pitch hollow pin 30 connecting each link of the chain. The pusher rolls 32 are located at intervals of 5 pins thus the distance between pusher roll centres is 10 inch (254mm). The pusher rolls 32 are manufactured of a crystalline formaldehyde resin, such as that sold under the trade mark DELRIN. The pusher rolls 32 are maintained in position between the opposed paired sections by a spacer 33 therebetween.

Isll Ma: 6 The sprocket wheels 24 and 26 and chain 28 are fabricated so as to be specifically adapted for use with one another and to run quietly in use. Thus in use, the drive motor 12 operates to turn the drive shaft 14 and through transmission chain 16 and pulleys 18, 22 the driven shaft operates the driven sprocket wheel 24. The caterpillar chain 28 extends around the sprocket wheel 24 and the sprocket wheel 26 and therefore is driven in response to operation of the motor 12.

The caterpillar chain 28 and associated sprocket wheels 24, 26 are mounted in a frame 34, the frame having elongate hollow base sections 35 and spaced 1 0 upstanding side portions 36. The frame is typically mounted from a ceiling or on a support truss such that the conveyor in use is an overhead conveyor.

The base sections 35 are aligned with the direction of the caterpillar chains 28 and the sections are disposed with an open channel 35a located between them. The two caterpillar chains are located on either side of the channel 1 5 This therefore completes the drive assembly for the conveyor chain.

The drive assembly is associated with a conveyor chain 38, the conveyor chain 38 being illustrated in cross sectional view in FIG 4 and also in side view in FIG lOn.

Tile coiivyor chain 38 comprises a number of interconnected link elements, each link element comprising a pair of elongated spaced aligned plate members 40. The plate members 40 are formed of zinc plated mild steel. The plate members 40 are arranged in parallel alignment having a channel space therebetween, and the plate members 40 are flared at their outer edges to form wider sections. Apertures formed at the plate members 40 are used to support loads on appropriate hooks to be carried by the conveyor chain 48.

oo. 0Each pair of plate members 40 comprise together a link element, and adjacent link elements are rotated through 900 on a main directional axis of the e conveyor chain 38 as shown in FIG 5. The effect of the rotation of the link elements is to allow for bi-directional movement of the conveyor chain 38.

The links 40 have means to allow a bearing element to be press fitted into each link. Each pair of adjacent links 40 are interconnected by a bearing member 42, the bearing member being illustrated in plan view in FIG 6 and in i

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7 side view of FIG 5. The bearing member 42 includes a central body 44, the body 44 having a cruciform shape having four opposed limbs 45 on two axes, the axes being arranged generally at right angles to one another. Attached to each limb 45 of the body 44 is a bearing element 46 included a key type outer case having a urethane coating thereon. The urethane coating is typically resilient to high speed use and harsh conditions whilst also operating without excessive noise generation. The bearing elements 46 may be press fitted into the links 40, the links 40 being able to swivel around the bearings to thereby allow bi-directional movement of the conveyor chain 38. The distance 1 0 between centres of adjacent bearing members 42 is arranged to be 10 inches (254mm).

In use the conveyor chain 38 is mounted having at least a portion thereof running adjacent the caterpillar chain 28 as shown in FIG 1 and FIG 2. In fact, in the embodiment disclosed the conveyor chain 38 extends between the 1 5 aligned caterpillar chains 28 and below the chains 28. The chain 38 therefore runs through the open channel 35a as shown in FIG 4. It will be appreciated that the bearings 42 are located so as to be fitted within gaps in the frame 34 and to rest below the pusher rolls 32. As the pusher rolls 32 are moved in response to the chain 28 being driven the pusher rolls bear against the bearings 42 thereby creating a pushing and rolling action which drives the conveyor chain 38. The rolling action of the caterpillar chain 28 against the conveyor chain 38 creates a ,elatively smooth action which substantially reduces the noise generated from the movement of the caterpillar chain 28 and conveyor chain 38 when compared with prior art chains. As will be appreciated from the drawings, the pusher rolls 32 are of significant size to bear against the bearing members 42. Moreover, the spacing between the bearing members 42 (254mm) and pusher rolls 32 (254mm) is such that a pusher roll 32 is in contact with each bearing member 42 ensuring that the motive force from the motor 12 is transferred via the caterpillar chains 28 to the 30 conveyor chain 38. Moreover, the use of the urethane coated bearing member 42 and the plastics coating on the pusher rolls 32 ensures that adequate speed of the conveyor chain 38 can be maintained without intolerable noise levels for those working under or near the system.

Thus carry bags suspended from the links 40 of the conveyor chain 38 can be 3 5 transported at high speed without undue noise generation.

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8 Modifications and variations of the present invention such as would be apparent to a skilled addressee are deemed to be within the scope of the present invention. In particular, this has cleared up variations in the drive mechanism including substitutions of various different types of motor, and incorporation of gearing mechanisms where necessary can be made without J departing from the scope of the present invention.

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Claims (11)

1. A conveyor drive assembly, comprising: means operable to drive a drive chain; the drive chain having a plurality of pusher rolls located thereon at spaced intervals, the pusher rolls having an outer coating of plastics material; a conveyor chain assembly comprising a plurality of interconnected link elements each link element being conneced to adjacent link elements by a bearing member; the plurality of pusher rolls being adapted to bear against the 1 0 bearing members of the conveyor chain such that in use, movement of the drive chain is transferred to the conveyor chain by the plurality of pusher rolls bearing against bearing members thereby driving the conveyor chain.

2. A conveyor drive assembly according to claim 1, wherein the drive V chain comprises a caterpillar chain formed of a plurality of interconnecting 0. 15 sections connected by hollow pin members, the hollow pin members serving as a support axle for the pusher rolls. ;o

3. A conveyor drive assembly according to any one of the preceding claims adapted for use in an overhead conveyor arrangement.

4. A conveyor drive assembly according to any one of the preceding 20 claims wherein the bearing is a urethane coated bearing.

5. A conveyor drive assembly according to any one of the preceding claims wherein the outer coating of plastic material on the pusher rolls is a low friction low noise plastics material, for example crystalline formaldehyde resin.

6. A conveyor drive assembly according to any one of the preceding claims, in which the conveyor chain is formed on link elements adapted for bi- directional travel, wherein each link element comprises a pair of aligned opposed plate members, adjacent link elements being connected by a bearing member in the form of a cruciform casting having a number of separate bearing elements mounted thereon.

7. A conveyor drive assembly according to claim 6 in which the bearing elements are arranged in pairs on two opposing axis of the cruciform casting, thereby allowing the link elements to swivel in two separate axis.

8. A conveyor drive assembly according to claim 6 wherein the bearing elermnts are a press fit onto the cruciform casting.

9. A conveyor drive assembly according to any one of the preceding claims wherein the distance between centres of the bearing members of 1 0 adjacent link elements corresponds to the distance between centres of pusher rolls on the drive chain.

A conveyor drive assembly according to any one of the preceding claims wherein there are provided a pair of aligned parallel drive chains supporting a plurality of pairs of pusher rollers thereon the pusher rollers :1 5 being separated by a spacer member, and the drive chains being supported in a frame including a pair of lowermost spaced channel members, the spacing between the channel members being such as to allow the conveyor chain therethrough, the spacing between the pusher rollers being sufficient to allow each pusher roll of a pair to act on opposing bearings of a bearing member.

11. A conveyor drive assembly substantially as hereinbefore described with reference to the accompanying drawings. C Dated this 5th day of August 1996 SEKWAH PTY LTD Trading as AUSTVEYORS (SA) By their Patent Attorneys, COLLISON CO. AlP ABSTRACT fhe invention relates to a conveyor drive assembly typically for use in overhead conveyors. A drive chain is driven though a motor and has a plurality of pusher r-"s thereon at spaced intervals. The pusher rolls have an outer coating of a Astics material, eg, crystalline formaldehyde resin. A conveyor chain is aligned with the drive chain over part of its length. The conveyor chain includes link '°ments connected by a bearing member in the form of a cruciform casting carrydi, nairs of opposed bearing elements on at least two orthogonally separatea The bearing member is urethane coated. The conveyor chain I 0 is driven by the pus, or rolls contacting and driving the bearing members. The conveyor drive assembly, through use of the plastics and urethane coated components, allows the conveyor to operate without excessive noise. 0 °I 0 *I 4404 i I 9« 6 0 0& 4