GB2104560A

GB2104560A - Device and method for delivering fibre flocks

Info

Publication number: GB2104560A
Application number: GB08220501A
Authority: GB
Inventors: Hermann Trutzschler
Original assignee: Truetzschler GmbH and Co KG
Current assignee: Truetzschler GmbH and Co KG
Priority date: 1981-07-18
Filing date: 1982-07-15
Publication date: 1983-03-09
Also published as: JPH0147566B2; JPS5836225A; GB2104560B; ES8305433A1; IT1151890B; ES514075A0; FR2509757A1; FR2509757B1; CH659662A5; IT8222083A0; BR8204159A; DE3128564A1

Abstract

In a device for delivering a fibre- flock fleece, to, for example a carding machine having a feed shaft 2, an air circulation path is provided for the purpose of maintaining a current of air in the feed shaft in the direction of the outlet end. In order to reduce the effect of fluctuations, especially in the amount of flocks in the feed shaft, on the condensing of the flocks, air- branching means (10), are provided at at least one place in the air-circulation path, permitting air to flow through the air-branching means in order to alter the amount of air in the air- circulation path. <IMAGE>

Description

SPECIFICATION Device and method for delivering fibre flocks This invention relates to a device and method for delivering fibre flocks, especially for feeding a textile machine, for example a carding machine. In one form, the device has a feed shaft which has an upper open inlet end and a lower open outlet end, elements for introducing fibre flocks being associated with the inlet end and elements for delivering a non-woven fibre-flock fleece being associated with the outlet end and there are provided regulating elements for regulating the amount of fibre flocks introduced into the inlet end, in which device air-circulation elements, which form a closed system, are provided to maintain a flow of air in the feed shaft in the direction of the outlet end, the air-circulation elements comprising air-outlet openings located in the feed shaft between the inlet and outlet ends, an air duct located outside the feed shaft and having a first open end associated with the air-outlet openings and a second open end associated with the region of the inlet end of the feed shaft and a fan, located in the air duct, for conveying air along a closed path into the region of the inlet end of the feed shaft, out of the feed shaft through the air-outlet openings and through the air duct.

In a device known from DE-PS 28 04 413, the circulating air in the closed air-circulation system is used, inter alia, to condense the column of flocks in the feed shaft. The degree of condensing is one of the factors determining the amount of product drawn off at the take-off rollers. If the degree of condensing is constant with time, the amount of product drawn off is also constant with time, that is to say, uniformity in respect of time has been achieved. The degree of condensing is a function of the speed at which the air flows through the flocks. The air speed is a function of the pressure difference produced by the fan and of the flow resistance of the column of flocks in the feed shaft. When the other conditions are constant, the flow resistance is a function of the height of the column of flocks.The variation in the amount of flocks results in varying flow resistances and hence varying air speeds as well as varying differential pressures upstream and downstream of the column of flocks, that is to say, also upstream and downstream of the fan. This results in varying degrees of condensing and fluctuations in the uniformity of the fibre-flock fleece taken off.

On the other hand, the pressure in the feed shaft is used to regulate the feeding of flocks from the supply shaft. In operation there are, therefore, fluctuations, within the regulation system, in the above-mentioned influencing variables.

An object of the invention is to reduce the effect of the fluctuations in the above-mentioned influencing variables, especially the amount of flocks in the feed shaft, on the condensing of the fibre flocks.

According to the invention there is provided a device for delivering a fibre-flock fleece, especially for feeding a textile machine, for example a carding machine, this device having a feed shaft which has an upper open inlet end and a lower open outlet end, elements for introducing fibre flocks being associated with the inlet end and elements for delivering a fibre-flock fleece being associated with the outlet end and there being provided regulating elements for regulating the amount of fibre flocks introduced into the inlet end, in which device air-circulation elements, which form a closed system, are provided to maintain a flow of air in the feed shaft in the direction of the outlet end, the air-circulation elements comprising air-outlet openings located in the feed shaft between the inlet and outlet ends, an air duct located outside the feed shaft and having a first open end associated with the air-outlet orifices and a second open end associated with the region of the inlet end of the feed shaft, and a fan, located in the air duct, for conveying air along a closed path into the region of the inlet end of the feed shaft, out of the feed shaft through the air-outlet orifices and through the air duct, characterised in that air-branching means are provided at at least one place in the aircirculating elements these means permitting air to flow through the air-branching means in order to alter the amount of air in the closed air-circulation path.

As a result of the provision of air-branching means in the air-circulation elements, the air flow circuit which is provided by the air duct and the feed shaft is opened, so that, for purposes of equalisation a partial air stream can be supplied to the air flow circuit from the atmosphere or a partial air stream can escape from the air flow circuit into the atmosphere. A particular advantage of this measure is that the effects of machine-specific flow resistances are greatly reduced. This is of significance because several devices (flock-feeding devices) are arranged in a general installation and the aim is to achieve the same flow conditions inside all the feed shafts.

Since, according to the invention, the aircirculation system of all the shafts communicates with the atmosphere, the same comparative pressure prevails in that respect in each case. In this manner, the influence of the amount of flocks in the feed shaft (height of column of flocks) on the degree of condensing is reduced, so that fluctuations in the height of the flocks exert less influence on the degree of condensing. If the air opening is located on the intake side of the fan, there is, for example, no longer so great a throttling effect on the intake side, in contrast to the known device. Depending upon the fluctuations, the fan can take in air from the atmosphere. As a result of the reduced throttling effect, the effect on the speed at which the air passes through the column of flocks in the feed shaft is reduced.At the same time, the influence of the fluctuations in the column of flocks on the degree of condensing and thus on the uniformity with time of the fibre-flock fleece fed to the carding machine is also reduced.

The air opening is advantageously located in the air duct, either on the intake side or on the output side, or on both the intake side and the output side, of the fan. In accordance with a further advantageous embodiment, the air opening is located in the feed shaft upstream of the air outlet openings.

The air leaving the air outlet opening contains dust. This is, however, not a great problem as only relatively small currents of air enter and leave by the air opening and of these, only the outgoing air streams contain dust. In order to ensure that the air in the spinning mill is kept clean also in respect of the small outgoing air stream a filter may be provided in the air-branching means, that is to say the air opening in accordance with an especially preferred embodiment.

Regulating elements are preferably provided which regulate the flow of air through the airbranching means, it being possible to use, as the regulating elements, preferably a throttle, for example a slide plate, a flap or a plate. These elements are attached to the air duct either directly or indirectly and cooperate with the air opening. Adjustment of the elements alters the size of the air opening and hence the flow through the same. It is possible in this manner especially to match the flow of air inside the feed shafts of several carding-machine feeding devices. These elements can be controlled as a function of the pressure or of the speed of the circulating air.This can be effected mechanically, for example by means of spring loading or by means of a control system composed of a measuring element (for example for measuring pressure or speed), control means and a control element (for example a servo motor or a cylinder at the adjustable air opening).

By way of example, certain illustrative embodiments of the invention will now be described with reference to and as illustrated by the accompanying schematic drawings, of which: Figure 1 shows a delivery device having an air opening in an air duct, between an air-outlet orifice and a fan, Figure 2 shows a delivery device having an air opening in a feed shaft, above the point at which the flocks are introduced, Figure 3 shows an air opening with an upstream filter, Figure 4 shows a slide plate associated with the air opening, Figures 5a and 5b show a rotatable disc associated with the air opening in an open (Figure 5a) and half-open (Figure 5b) position, and Figures 6a and 6b show a pivoting, spring loaded disc associated with the air opening, with air flowing in (Figure 6a) and air flowing out (Figure 6b).

Figure 1 shows a carding-machine feeding device having an upper supply shaft 1 and a lower feed shaft 2. The feed shaft 2 has an upper open inlet end 2a and a lower open outlet end 2b. A flock-feeding device is associated with the inlet end 2a, this device comprising an intake roller 3 and an opener roller 4. Below the outlet end 2b are located two take-off rollers 5a, 5b which feed the fibre-flock fleece to a known carding machine.

Furthermore, in a side wall of the feed shaft 2 an electronic pressure switch 6 is located between the inlet end 2a and the air-outlet opening 7a, this switch cooperating with control means (not shown) and with the drive motor (not shown) for the intake roller 3 for the purpose of regulating the amount of fibre flocks introduced at the inlet end 2a. Moreover, air-circulation elements, which form a closed system, are provided for the purpose of maintaining a current of air in the feed shaft 2 in the direction of the outlet end 2b.These aircirculation elements comprise air-outlet openings 7a, 7b, which are located in the wall of the feed shaft 2, between the inlet end 2a and the outlet 2b, an air duct 8 located outside the feed shaft 2 and having a first open end 8a associated with the air-outlet openings 7a, 7b and a second open end 8b associated with the inlet end 2a of the feed shaft 2. In the air duct 8, a fan 9 is located for the purpose of conveying air out of a closed path into the inlet end 2a of the feed shaft 2, out of the feed shaft 2 through the air-outlet openings 7a, 7b and through the air duct 8. As air-branching means, an air opening 10 is provided which is located in the air duct 8, between the fan 9 and the first open end 8a of the air duct 8.The air opening 10 can be designed as a simple opening in the wall of the air duct 8 and provided with a connection piece 1 0a.

in the drawing, the solid arrows represent the fibre flocks 1 a (in the supply shaft 1) and 11 b (in the feed shaft 2), the blank arrows represent the air currents, and the half-solid and half-blank arrows represent the fibre flocks in the air current. Above the supply shaft 1 extends a conveyor duct 12 for the pneumatic conveyance of the fibre flocks from the fine opener (not shown) to several supply shafts. An air-distribution device 1 3a, 1 3b for the uniform distribution of air across the width is located inside the air duct 8, between the fan 9 and the end 8b. The sheet-metal casing of the device is designated by reference numeral 14.

When the pressure in the feed shaft 2 falls, the intake roller 3 is switched on, or caused to rotate more rapidly, by means of the pressure switch 6 of the drive (not shown), so that fibre flocks are fed into the feed shaft 2 from the supply shaft 1. The amount of flocks 11 b in the feed shaft 2 increases as a result, so that the fan 9 has to operate against a higher resistance, that is to say, the fan 9 takes in less air. Correspondingly, the fan 9 emits less air, so that less air is available for the purpose of condensing. At the same time, a relatively great partial vacuum (i.e. a relatively low pressure) is produced in the air duct 8, between the end 8a and the fan 9. As a result, air flows through the air opening 10 from outside (atmosphere) into the air duct 8, so that the amount of air is increased. As a result, the fan 9 is able again to introduce more air through the end 8b into the feed shaft 2, for the purpose of condensing. Conversely, when the pressure in the feed shaft rises, air passes out of the air duct 8, through the air opening 10, to the outside (into the atmosphere), so that the fan 9 introduces less air than it would without the opening 10 through the end 8b into the feed shaft 2 for the purpose of condensing.

In accordance with Figure 2, the fan 9 is located to the side of the feed shaft 2, this fan conveying a current of air through the end 8b of the air duct 8 into the feed shaft 2. The end 8b is arranged as a lateral opening in the wall of the feed shaft 2, above the air outlet orifices 7a, 7b and below the opener roller 4. The air current is blown by the fan 9 through the end 8b into the feed shaft 2 and leaves the feed shaft 2, after having flowed through the fibre flocks contained therein and having compressed the same, via air outlet opening 7a, 7b. The air opening 10 is located in the wall of the feed shaft, above the airoutlet openings 7a, 7b, and below the opener roller 4, approximately level with the end 8b and opposite the same. It can also be located above the end 8b.The air opening 10 has a connection piece 1 Oa, which communicates with the outside air (atmosphere). The air-outlet openings 7a, 7b open into a common connecting channel (not shown in greater detail) to which the air duct 8 is connected.

;n accordance with Figure 3, a connection piece 1 Oa, in which a filter 1 5 is located, is connected to the air duct 8, so that the inflowing, and, of more importance, the outflowing, air is cleaned.

The size of the air opening 10 is chosen so that an appropriate fraction only of the air stream passes through this opening.

Figure 4 shows, as a throttle, a sliding plate 16, which is attached to the air duct 8 by means of a bolt 1 7 and a slot 18 in such a manner that the air opening 10 can be completely or partially opened or closed. This regulates the magnitude of the air current through the opening 10.

Figure 5 shows, as a throttle, a rotatable disc 19, which is attached to the air duct 8 by means of the connection piece 1 Oa. Turning of the disc 19 can alter the position of the opening 10 from open (Figure 5a) to, for example, half-closed (Figure 5b), or any other position between fully open and fully closed.

Figures 6a and 6b show as the throttle, a flap 21 able to move about a pivot 20 and loaded on each side by a leaf spring 22 or 23; the leaf springs 22, 23 are attached to the inside wall of the connection piece 1 Oa. On the wall of the connection piece 1 0a opposite the free end of the flap 21 a projection 24 is located, which serves for example to close the flap 21. Figure 6a shows the position of the flap 21 in which air flows from the (external) atmosphere through the air opening 10 into the air duct 8, while Figure 6b shows air flowing out of the air duct 8 through the air opening 10 to the outside. The springs 21, 22 are selected according to the force of the air flowing in or out that is required to be sufficient to move the flap 21 in one direction or the other.

The regulation of the flow of air through the air opening 10 can be effected by adjusting by hand the position of the slide plate 1 6 or of the disc 1 9.

The position of the slide plate 1 6, the disc 1 9 or the flap 21 can also be adjusted automatically, for example as a function of the fibre material or similar influencing factors.

Although the invention has been illustrated using a flock-feeding device having two shafts (upper supply shaft and lower feed shaft) by way of example, the invention is in no way limited to this embodiment. The invention can also be used in the case of a flock feeding device having a single feed shaft, since the fibre flocks can be supplied pneumatically by a fine opener located upstream.

Claims

1. A device for delivering fibre flocks, the device having a feed shaft through which fibre flocks pass, the feed shaft having an air inlet and an air outlet downstream of the inlet, the inlet and the outlet being connected together by a duct and the feed shaft, air outlet, duct and air inlet together defining an air circulation path in which a fan is located, for generating an air stream around the circulation path, wherein the circulation path is a partially closed path having a partial vent at at least one place in the path to allow air to pass into or out of the circulation path.

2. A device according to claim 1 in which the fan is located in the air duct.

3. A device according to claim 1 or 2 in which the feed shaft has an open upstream end at which means for feeding fibre flocks into the feed shaft are provided.

4. A device according to claim 3 in which the air inlet is in the region of the upstream end of the feed shaft.

5. A device according to claim 3 in which the air inlet is upstream of the greatest level which, in use, a column of flocks in the feed shaft attains.

6. A device according to any preceding claim in which the air outlet is defined by a plurality of openings in the feed shaft.

7. A device according to any preceding claim in which the air outlet is in the region of the downstream end of the feed shaft.

8. A device according to any preceding claim in which regulating means is provided for regulating the amount of flocks fed into the feed shaft.

9. A device according to any preceding claim in which the feed shaft is substantially vertical with the upstream end of the shaft at the top.

1 0. A device for delivering fibre flocks, the device having a feed shaft which has an upper inlet end and a lower outlet end, elements for introducing fibre flocks being associated with the inlet end and elements for deliverying fibre-flocks being associated with the outlet end and their being provided regulating elements for regulating the amount of fibre flocks introduced into the inlet end, in which device air-circulation elements, which form a closed system, are provided to maintain a flow of air in the feed shaft in the direction of the outlet end, the air-circulation elements comprising air-outlet openings located in the feed shaft, between the inlet and outlet ends, an air duct located outside the feed shaft and having a first open end associated with the air-outlet openings and a second open end associated with the region of the inlet end of the feed shaft, and a fan, located in the air duct, for conveying air along a closed path into the region of the inlet end of the feed shaft, out of the feed shaft through the air-outlet openings and through the air duct, wherein airbranching means are provided at at least one place in the circulation path these means permitting air to flow through the air-branching means in order to alter the amount of air in the aircirculation path.

11. A device according to claim 10, in which the air-branching means have an air orifice located in the air duct between the fan and the first end of the air duct.

12. A device according to claim 10, in which the air-branching means have an air orifice located in the air duct between the fan and the second end of the air duct.

13. A device according to claim 10 in which the air-branching means have a first air orifice located in the air duct between the fan and the first end of the air duct, and a second air orifice located in the air duct between the fan and the second end of the air duct.

14. A device according to any of claims 10 to 13, in which the air-branching means have an air orifice located in the feed shaft above the airoutlet openings.

15. A device according to any of claims 10 to 14 in which a filter is provided in the air-branching means.

16. A device according to any of claims 10 to 15, in which regulating elements are provided which regulate the flow of air through the airbranching means.

17. A device according to claim 16, in which the regulating elements have a variable throttle for the purpose of varying the sectional area of flow through the air-branching means.

18. A device according to claim 1 7 in which the throttle has a sliding plate, which is attached directly or indirectly to the air duct and cooperates with the air opening.

19. A device according to claim 17, in which the throttle has a movable flap which is attached directly or indirectly to the air duct and cooperates with the air orifice.

20. A device according to claim 17, in which the throttle has a rotatable plate which is attached directly or indirectly to the air duct and cooperates with the air orifice.

21. A device for delivering fibre flocks, the device being substantially as herein described with reference to and as illustrated by Fig. 1 or by Fig. 2 of the accompanying drawings.

22. A device as claimed in claim 21, the device being substantially as further described herein with reference to and as illustrated by Fig. 3, or by Fig. 4, or by Figs. 5a and 5b or by Figs. 6a and 6b of the accompanying drawings.

23. A textile machine including a device for delivering fibre flocks to the machine, the device being as claimed in any preceding claim.

24. A textile machine as claimed in claim 23 wherein the machine is a carding machine.

25. A method of delivering fibre flocks, the method including feeding fibre flocks into a feed shaft and drawing the fibre flocks out of the feed shaft after they have passed therethrough, and circulating air through flocks in the feed shaft the air passing into the feed shaft through an air inlet along the feed shaft in the same direction as the fibre flocks out of the feed shaft through an air outlet and back through a duct to the air inlet, wherein the air circulation path is a partially closed path with a partial vent being provided at at least one place in the path to allow air to pass into or out of the circulation path.

26. A method as claimed in claim 25 in which the flocks build up as a column at the downstream end of the feed shaft.

27. A method as claimed in claim 26 in which air passes into the feed shaft upstream of the flock column and out of the feed shaft at a location within the column.

28. A method of delivering fibre flocks, the method being substantially as herein described with reference to and as illustrated by Fig. 1 or by Fig. 2 of the accompanying drawings.

29. A method as claimed in claim 28, the method being substantially as further described herein with reference to and as illustrated by Fig.

3, or by Fig. 4, or by Figs. 5a and 5b or by Figs. 6a and 6b of the accompanying drawings.