GB2067608A

GB2067608A - Feeding fibres to carding machines

Info

Publication number: GB2067608A
Application number: GB8001675A
Authority: GB
Original assignee: Cosmopolitan Textile Co Ltd
Current assignee: Cosmopolitan Textile Co Ltd
Priority date: 1980-01-18
Filing date: 1980-01-18
Publication date: 1981-07-30
Also published as: FR2474064B3; DE3041671A1; FR2474064A1; IT1129921B; IT8068830A0

Abstract

Fibres, as flock, fleece or web, are continuously weighed prior to entering a carding or other machine so as to achieve uniform delivery. The fibres are withdrawn from the weighing step at a uniform rate and are fed to the weighing step at a varying rate depending on the observed instantaneous weight of the travelling fibres so as to tend to keep said observed weight constant. <IMAGE>

Description

SPECIFICATION Method and apparatus for feeding fibres to carding or other machines This invention relates to a method and apparatus for feeding fibres to carding or other machines.

If a carding or other fibre treatment machine is to produce a uniform web or other assembly of fibres, it is desirable that fibres be fed to the machine uniformly. Fibre opening and preparation machinery, however, does not operate uniformly in the main - fibre is usually put into a system from the bale, and blending is carried out by weighing batches of fibre, and irregularities in the rate of supply of fibre to equipment down the line result from both these causes, since the introduction of each bale and the weighing out of each batch represents a concentration of fibre.

Attempts have been made to compensate for such irregularities in the supply of fibre by weighing the fibre in a continuous manner just prior to its entering a carding or other machine.

Some of these attempts have involved weighbelts or weigh plates supplied with fibre in flock or fieece form from a chute or other feed and delivering to the input of, for example, a carding machine. The weighbelt or weigh plate is used to control the speed at which the fibres are fed to the carding machine - if the weight of fibres on the belt is light, the belt, together with attendant infeed and outfeed rollers, is speeded up, and if the weight is heavy, slowed down, so as to tend to keep the delivery of fibres constant. The speeds of the infeed and outfeed rollers and of the weigh belt are always kept in proportion to each other and possibly to the speed of equipment in the fibre processing line as well.

Such an arrangement is relatively complicated and expensive to install and maintain. Even so, the arrangement does not necessarily result in a very uniform card web or other fibre assembly. The weighbelt or weigh plate is usually made quite long - this is so that a reasonable quantity of fibre is presented for weighing. However, it is possible for the weight of fibres on the belt to be iight, so that the belt is moved faster to compensate, but the distribution of fibres on the belt is irregular so that at one point there is a concentration of fibre. Such concentration will be moved in to the carding or other machine at a faster than average rate, thus resulting in an even more irregular product than would be the case without any control system.

The invention comprises a method for feeding fibre uniformly to a carding or other machine in which method the fibre is continuously weighed prior to being taken in to the carding or other machine, characterised in that the fibre is withdrawn from the weighing step at a constant rate, and fibre is fed to said weighing step at a variable rate in accordance with the observed instantaneous weight so as to tend to keep the observed weight constant.

The weighing step takes place preferably over a length of fibre travel which is short, for example, commensurate with the fibre length.

The invention also comprises apparatus for feeding fibre to a carding or other machine comprising weighing means for continuously weighing travelling fibre prior to its being taken in to said carding or other machine, first fibre feed means for feeding fibre to said weighing means and second fibre feed means for withdrawing fibre from said weighing means, characterised by control means adapted to control the said first fibre feed means in accordance with the observed instantaneous weight so as to tend to keep the observed weight constant.

The apparatus may be so arranged that the distance the fibre travels over said weighing means is commensurate with the fibre length.

Said weighing means may comprise a weigh plate.

One embodiment of apparatus and a method for feeding fibre to carding or other machines will now be described with reference to the accompanying drawings in which the single Figure is a diagrammatic side elevation.

The Figure illustrates a method and apparatus for feeding fibre uniformly to a carding or other machine. Fibre 11 in flock form is fed by a roller 14 from a chute 12 on to a conveyor 13 driven by a motor 1 5 connected to a roller 1 6 of the conveyor 14. The fibre 11 is fed from the conveyor 14 over a weigh plate 17 and withdrawn from the weigh plate 1 7 by infeed rollers 18 of a carding machine (not shown). The weigh plate is mounted on one or two load cells 19 depending on the width of the apparatus -- if the plate 1 7 is intended for use with, say, a 100 inch card, two load cells will usually be preferred situated either side the mid-point of the plate 1 7 between said mid-point and the edge of the plate.

The length of the plate 17 in the direction of fibre travel is short, as compared with prior art proposals, and commensurate, indeed, with the fibre length. The length of the plate - "1" in the drawing -- is about 5 to 10 cm.

The load cell or cells 19 are connected to a controller 21 for the motor 15, so that when the weight on the plate 1 7 falls below a predetermined value, the motor 1 5 is caused to increase its speed, and when the observed weight rises above a predetermined value the motor 1 5 reduces its speed. This tends to keep the observed weight constant.

The rollers 18, being run at substantially constant speed, take fibres - in fleece form - in to the carding or other machine at substantially constant speed. Since the weight of fibre on the weighpan is maintained constant, and hence the fibre density on the weighpan is substantially constant, the constant speed infeed rollers withdraw fibre uniformly from the weigh plate.

It might in some circumstances be desirable also to connect the roller 14 to the controller 21 so as to increase or decrease in speed with the conveyor 1 3.

Claims

1. A method for feeding fibre uniformly to a carding or other machine in which method the travelling fibre is continuously weighed prior to being taken in to the carding or other machine, characterised in that the fibre is withdrawn from the weighing step at a constant rate, and fibre is fed to the weighing step at a variable rate in accordance with the observed instantaneous weight so as to tend to keep the observed weight constant.

2. A method according to claim 1, characterised in that said weighing step takes place over a length of fibre travel commensurate with the fibre length.

3. Apparatus for feeding fibre to a carding machine comprising weighing means for continuously weighing travelling fibre prior to its being taken into said carding or other machine, first fibre feed means for feeding fibre to said weighing means, and second fibre feed means for withdrawing fibre from said weighing means, characterised by control means adapted to control the said first feed means in accordance with the observed instantaneous weight so as to tend to keep the observed weight constant.

3. Apparatus for feeding fibre to a carding or other machine comprising weighing means for continuously weighing travelling fibre prior to its being taken in to said carding or other machine, first fibre feed means for feeding fibre to said weighing means, and second fibre feed means for withdrawing fibre from said weighing means, characterised by control means adapted to control the said first fibre feed means in accordance with the observed instantaneous weight so as to tend to keep the observed weight constant.

4. Apparatus according to claim 3, characterised in that the distance the fibre travels over said weighing means is commensurate with the fibre length.

5. Apparatus according to claim 3 or claim 4, characterised in that said weighing means comprise a weigh plate.

New claims or amendments to claims filed on 20 February 1981.

Superseded claims 1 and 3.

New or amended claims: -

1. A method for feeding fibre uniformly to a carding machine in which method the travelling fibre is continuously weighed prior to being taken into the carding or other machine, characterised in that the fibre is withdrawn from the weighing step at a constant rate, and fibre is fed to the weighing step at a variable rate in accordance with the observed instantaneous weight so as to tend to keep the observed weight constant.