GB2229459A - Faller bars - Google Patents

Abstract

The faller bar 10 includes a row of pins 12 which are held in place by the injection moulding of carbon fibre and nylon which injection moulding comprises the main body of the faller bar. The injection moulding includes two pairs of opposed flats 18 and 20 which co-operate with a mechanism in order to assist in preventing the bar from pivoting when being driven. A metal reinforcing rod 22 may extend within the moulding between the end 14 of the bar and the row of pins 12. The injection moulding components may be in the ratio of 40 per cent carbon fibre and 40 per cent nylon (by weight). <IMAGE>

Description

FALLER BARS.

The present invent ion relates to faller bars and to a method of making faller bars.

in a known method for manufacturing faller bars which are designed to be conveyed by helical drivels, the bar is made holding pins upside down In a row by a Jig.

An Inverted U-section reinforcing bar is then placed over the blunt ends of the row of pins and nylon is then inject ion moulded about the blunt ends of the pins and the reinforcing bar. After the nylon has set the bar is checked for its alIgnment along its length and the malleable reinforcing bar not only enables a bent bar to be stralghtened but also, in use, provides the necessary support for the pins.

In an alternative method of manufacturing faller bars a metal bar is cast and then machined to provide a groove and suitable formations at either end to enable the bar, In use, to be driven. Pins are then elther directly soldered to the metal bar or pinned Inserts are glued into place. Such a bar Is extremely expensive to produce as a result of the metal casting and machining and consequently the pins or the pinned Inserts on such a bar must be replaceable. The time and effort expended in replacing such pins or Inserts renders the servicing or repair of such bars extremely expensive. Furthermore, the cast metal bar Is malleable to enable normally bent bars to be straightened prlor to use.

Accordingly with one prior bar (namely the nylon and metal relnforcement bar), a disposable bar is provided which requires the presence of two materlals in order to achieve: a) the ability of a bar to be straightened after manufacture (this Is dependent both on the malleability and strength of the metal and the flexIbility of the nylon to allow such stralghtening), and b) the ability of the nylon to hold the pins and strengthening bar in place.

In the other prlor bar a single material (namely metal) is able to hold the pins In place but that bar requires the metal to be malleable In order to enable a bent bar to be straightened and It also requires the metal to be machined and the pins affixed to the metal (after casting and machining) rather that at the time of casting the metal.

A further disadvantage with the prlor faller bars is that they are relatively heavy and inflexible when subjected to sudden shocks such as when there Is a lap on and accordingly damage to the drive mechanism can occur.

Additionally as the faller bars are heavy they require a considerable amount of power to drive them and the wear on the drive mechanism may be considerable.

According to one aspect of the present Invent ion a fal ler bar Includes a row of pins projecting from a carbon fibre Inject Ion moulding. Although carbon fibre has been around for many years it has never been proposed to use this material In faller bars according to the present Invention. The use of such material allows the fal ler bar to be lightweight thus saving on the power required to drive a row of faller bars and wear on the drive mechanisms for such faller bars. Furthermore, such a bar may be flexible to reduce .pa shock to a system when there is a lap on thus reducing the chances of the pins or drive mechanism failing.

According to another aspect of the present inventlon, a faller bar Includes a row of pins extending from an elongate Injection moulding including carbon fibre with a cross-sectlon through the bar along the row of pins comprising solely the Inject Ion moulding or the Injection moulding and pins. Preferably any crosssect lon along substantlally the complete length of the row of pins comprises solely the Injection moulding or the inject ion moulding and pins.

According to a further aspect of the present Invention, a faller bar Includes a row of pins extending from an elongate injection moulding Including carbon fibre with the Inject ion moulding belng the only material extending along the row of pins with the excluslon of the embedded pins.

At least one end region of the faller bar may Include carbon fibre which has been injection moulded In a shape adapted to co-operate with a drive for the faller bar.

With such a faller bar the row of pins Is able to be held In place by the Injection moulding and the inject Ion moulding Is also sufficiently strong to be able to resist the forces exerted, In use, on the pins. The choice of an Inject ion moulding alone along the length of the pins Is not an obvious one as the inject Ion moulding Is not able to be bent at amblent temperature In order to straighten a bar, such as is required In the prlor bars.

Indeed any party looking at faller bars who was an expert In materlals would appreciate that the bars have to be bent at ambient temperatures after manufacture, and thus would appreciate that a malleable element had to be included along the length of the row of pins as In all prior faller bars, and they would also appreciate that carbon fibre does not have that required property.

The injection moulding may comprise a mixture of carbon fibre and nylon and may comprlse approximately 40% carbon fibre and 60% nylon.

The Injection moulding may extend beyond at least one end of the row of pins. The bar may Include reinforcement extending along at least part of the bar at or towards one end.

The injection moulding may Include formations with which a drive mechanism is arranged to co-operate.

According to another aspect of the present Invention, a method of making a faller bar comprises injection moulding a material including carbon fibre around an end of a row of pins.

According to a further aspect of the present inventlon, a method of making a faller bar comprises Injection moulding a material including carbon fibre around one end of a row of pins in which the material or the pins Is the only component present along at least part of the faller bar coextensive with the row of pins.

According to another aspect of the present invent ion, a method of making a faller bar Includes injection moulding a material Including carbon fibre around one end of a row of pins with the Inject ion moulded material being the only material extending along the row of pins with the excluslon of the embedded pins.

The method may comprlse Injection moulding a material Including carbon fibre and nylon which may be substantially In the ratio of 40% carbon fibre and 60% nylon (by welght).

The method may comprise Injection moulding the material around at least one reinforcing member.

The present invention may be carried Into practice In varlous ways, but one embodiment will now be described by way of example and with reference to the accompanying drawing which is a schematic perspective vlew of a faller bar 10.

The fal ler bar 10 Includes a row of pins 12 proJecting from therefrom, the row being held In place by Inject ion moulding carbon fibre and nylon around one end of the pins. The moulding Includes annular portions 14 and 16 at elther end thereof which are arranged to cooperate either directly or Indirectly, with a chain drIve.

The moulding also Includes two palrs of opposed flats 18 and 20 spaced from each other and located between one annular portion and the pins 12. The opposed flats assist In maintaining the correct direction of the pins 12 by co-operating with a mechanism (not shown) which prevents the bar for pivoting. A metal reinforcing rod 22, shown I n chain Ines, may extend within the moulding between the end 14 and the row of pins 12 to Increase the strength of that part of the bar.

The moulding material Is comprlsed by a mixture Including approximately 40% by weight carbon fibre granules and 60% by welght nylon. The moulding material Is InJected extremely rapidly, In a matter of mililseconds, Into a heated mould in order to ensure that the material reaches all parts of the mould and can cool and harden under controlled conditlons to ensure that the finished bar leaves the mould stralght.

The bar Is extremely light, thereby reducing the wear on and power required by a driving mechanism.

Furthermore the bar does not have to be machined after moulding thereby considerably simplifying the manufacturing process.

Should a machine including carbon fibre faller bars be subjected to a lap then the sudden shock normally experienced will be dissipated by the ability of the bars to flex by bending and by twisting resulting from torslon. Ultimately the faller bar will break, should the shock be severe enough rather than rlsk damage to the drive. Damage to the drive Is particularly likely to occur in existing machines having a chain drive for the faller bars. The present invention Is also applicable to failer bars made of the same material with ends adapted to be screw driven.

Claims (18)

1. A faller bar including a row of pins projecting from an injection moulding including carbon fibre.

2. A faller bar as claimed in Claim 1 in which a cross-section through the bar along the row of pins comprises solely the injection moulding or the injection moulding and one of the pins.

3. A faller bar as claimed in Claim 2 in which any cross-section along substantially the complete length of the row of pins comprises solely the injection moulding or the injection moulding and a pin.

4. A failed bar as claimed in any preceding claim in which the injection moulding is the only material which extends along the row of pins.

5. A faller bar as claimed in any preceding claim in which at least one end region of the faller bar includes carbon fibre which has been injection moulded in a shape adapted to co-operate with a drive for the faller bar.

6. A fairer bar as claimed in any preceding claim in which the injection moulding comprises a mixture of carbon fibre and nylon.

7. A faller bar as claimed in Claim 6 in which the injection moulding comprises approximately 40% carbon fibre and approximately 60% nylon.

8. A faller bar as claimed in any preceding claim in which the injection moulding extends beyond at least one end of the row of pins.

9. A faller bar as claimed in any preceding claim including reinforcement extending along at least part of the bar at or towards one end.

10. A faller bar as claimed in any preceding claim in which the inject ion moulding includes formations with which a drive mechanism is arranged to co-operate.

11. A faller bar substantially as herein described with reference to, and as shown in the accompanying drawing.

12. A method of making a faller bar comprising injection moulding a material including carbon fibre around an end of a row of pins.

13. A method as claimed in Claim 12 in which the material which Is injection moulded around the end of a row of pins is the only component, apart from the pins present along at least part of the fal ler bar coextensive with the row of pins.

14. A method as claimed in Claim 12 or 13 in which the material which is injection moulded includes carbon fibre and nylon.

15. A method as claimed in Claim 14 in which the material includes a ratio in the region of 40% carbon fibre and 60% nylon by weight.

16. A method as claimed in any of Claims 12 to 15 comprising injection moulding the material around at least one reinforcing member.

17. A method of making a fal ler bar substantially as herein described with reference to, and as shown in the accompanying drawing.

18. A method as claimed in any of Claims 13 to 17 of making a faller bar as claimed in any of Claims 1 to 12.