GB2114085A - Flight link - Google Patents

Abstract

A flight link for a chain or scraper conveyor in which an attachment for a scraper flight is formed integrally with said flight link. The attachment 6, in the form of a channel section tang whose longitudinal axis is at 90 DEG to the longitudinal axis of the flight link, includes one or more through-bores 20, 22 whose axis or axes is or are normal to the longitudinal axis of the attachment. The attachment incorporates integral longitudinally extending strengthening ribs 18, 18A. <IMAGE>

Description

SPECIFICATION Flight link This invention relates to conveyors, and particularly to such conveyors known as scraper conveyors. The invention is particularly concerned with the linkages of the chains of such conveyors.

In a chain-driven scraper conveyor, some of the links of the chain, usually referred to as flight links, carry scraper bars which are adapted to engage the material to be conveyed from one point or another. Such scraper bars, or as they are more generally known, scraper flights, are conventionally welded directly onto the chain or alternatively bolted to an attachment welded to the chain, such attachment being provided specificallyforthis purpose.

The direct welding, or the bolting to the welded attachment, of the scraper flight often has the disadvantage of attachment failure due to poor attachment root strength, as experience has shown to be the case. In addition, it very often happens that the attachment is not welded to the chain at the correct angle, i.e. 900, with the result that in operation undue stresses are applied to the scraper flights since, consequent upon the incorrect positioning of the attachment, the scraper flights will not be at the required 900 angle. Thus failures will occur, and its is often necessary to replace the whole chain which is thus costly in down-time of the conveyor as it can take up to 3/4 weeks to produce and install a replacement chain.Such cost is often increased due to the fact that expensive plant labour has to be diverted from other operations, after the end of normal working time, to keep a conventional chain working whilst the new chain is fabricated.

The invention seeks to provide an improved form of chain which will obviate the above an other disadvantages of conventional chains.

According to the present invention, there is provided a flight link for a chain or scraper conveyor, in which an attachment for a scraper flight is formed integrally with said flight link.

Preferably, said attachment will be in the form of a channel section tang, the longitudinal axis of said tang being at 900 to the longitudinal axis of the flight link.

Said attachment will preferably include one or more through-bores for receiving means for securing the scraper flight to said attachment, the longitudinal axis or axes of said through-bores being normal to the longitudinal axis of said attachment. More preferably, there will be two such through-bores.

The attachment will preferably incorporate longitudinally extending strengthening ribs.

In order that the invention may be more readily understood, and embodiment thereof will now be described, b y way of example, reference being made to the accompanying drawings, wherein: Figure lisa perspective view of a flight link according to the invention; Figure 2 is a side elevation of the flight link of Figure 1; Figure 3 is a plan view on Figure 2; and Figures 4 and 5 are end views respectively in the direction of arrows IV and V in Figure 2.

Referring to the drawings, the flight link in the form of a drop forging, is indicated generally by reference numeral 2 and comprises a body portion 4 and an attachment portion 6, the body portion 4 and attachment portion 6 being formed integrally.

The body portion 4 is provided with integral strengthening bosses or lugs 8 and 10 on opposed faces of the body portion, said bosses or lugs being bored, as indicated by reference numerals 12 and 14, for receiving intermediate links (not shown) of the chain. A strengthening rib 1 6 is formed on the outer face of the body portion.

Projecting from the inner or front face of the body portion 4, is the attachment portion 6 which is formed integrally with the body portion 4 and which is located between the bosses or lugs 8 and 10. The attachment portion 6 has integral strengthening ribs 18 and 1 8A, and additionally has two longitudinally-spaced through-bores 20 and 22 through which may pass bolts (not shown) engageable by nuts (not shown) so as to secure a scraper flight (not shown) to the attachment. The scraper flight will seal against and engage face 24 of said attachment.

The longitudinal axis 6A of the attachment portion 6 is at 900 to the longitudinal axis 4A of the body 4, and the axes 20A and 22A of the through-bores 20 and 22 will be at 900 to the longitudinal axis 6a of the attachment portion 6, these dispositions being critical so as to ensure that the scraper flight, when secured to the attachment portion 6, is normal to the body 4.

The flight link 2 will preferably be formed from grade 080M 40 steel to BS 970 (Part 1)1972.

With a flight link according to the invention, there is no possibility of attachment failure due to poor attachment root strength, since the attachment portion 6 is an integral part of the link and not welded or otherwise secured to the body portion of the link. In addition, since the attachment portion will never be welded to the link, a user using a variety of chain cross centres will be able to stock replacement chains for emergency use without the necessity of stocking particular chains for particular conveyors. Chains having attachments welded directly to the chain are always special, since each conveyor is designed around the duty required to each installation, and it is not financially feasible to stock these special chains, and hence the chains must be individually produced to specific orders.

With a flight link according to the invention, by which the scraper flights are bolted on to the integral attachment, this problem is not suffered because it is feasible that spare chains can be stocked and used on a "call-off" order system.

Finally, unlike conventional scraper conveyors or chains, it will usually not be necessary to discard a scraper flight should the driving strands of the chain become stretched or worn, since the link can be replaced and the scraper flight reattached to the new link.

Claims (7)

1. A flight link for a chain or scraper conveyor, in which an attachment for a scraper flight is formed integrally with said flight link.

2. A flight link according to Claim 1, wherein said attachment is in the form of a channel section tang, the longitudinal axis of said tang being at 90 to the longitudinal axis of said flight link.

3. Aflight link according to Claim 2, wherein said attachment includes one or more throughbores for securing the scraper flight to said attachment.

4. A flight link according to Claim 3, wherein the longitudinal axis or axes of said throughbore(s) is or are normal to the longitudinal axis of said attachment.

5. A flight link according to any of Claims 1 to 4, wherein the attachment incoporates longitudinally extending strengthening ribs.

6. A flight link according to any of the preceding Claims, wherein said body portion has integral strengthening bosses or lugs on opposed faces of said body portion, said bosses or lugs being bored for the reception of intermediate links of the chain.

7. A flight link for a chain or scraper conveyor substantially as herein described with reference to and as illustrated in the accompanying drawings.