GB2063932A

GB2063932A - Suction end catchers

Info

Publication number: GB2063932A
Application number: GB8037874A
Authority: GB
Original assignee: Ernst Jacobi and Co KG
Current assignee: Ernst Jacobi and Co KG
Priority date: 1979-11-26
Filing date: 1980-11-26
Publication date: 1981-06-10
Also published as: DE2947575A1; IT1134454B; IT8026223A0

Abstract

Apparatus for the removal by suction of broken threads in a drawing frame of the kind which has co- operating grooved and pressure rollers 12, 13 at the frame outlet, comprises a suction tube 2 into which a broken thread leaving the frame outlet can be sucked and which has an opening directed approximately parallel to the axes of the rollers in the V-shaped outlet area thereof. <IMAGE>

Description

SPECIFICATION Apparatus for the removal by suction of broken threads in a drawing frame The invention relates to apparatus for the removal by suction of broken threads in a thread drawing frame of the kind which has co-operating grooved and pressure rollers at the frame outlet, and in whose vicinity the opening of a suction tube is located into which any broken thread leaving the rollers is sucked.

In known apparatus, the suction tube is constructed as a straight tube guided by the suction channel through a slotted link and issues into the vicinity of the grooved roller below the discharge area of outgoing threads. At the suction channel, the suction tube is carried in a resilient sleeve and the slotted link is constructed as an elongated slot, making it possible to swing the suction tube down from the drawing frame outlet.

The function of the suction tube is to suck in broken threads passing out of the outlet to prevent build up of fibres, referred to herein as lap formation, at the pressure and/or grooved roller.

Lap formation must be prevented because it can be the cause of damage to the spinning bands and rollers. The removal of laps takes a considerable amount of time during which it is necessary to shut down the drawing frame or the drawing frame of one unit. A high injury risk is also linked with removing laps by means of knives or hooks.

In known drawing frames, a stripping roller having a rubber covering rotates in contact with the pressure roller with the object of removing the thread dust adhering thereto.

In order to be able to pick up broken threads every effort is made to locate the suction tube opening close to the gap between the pressure and grooved rollers, but this is limited by the conical outlet area required by the thread. In addition, if there is a thread change, there may be different distances with respect to the suction tube opening, and it is known therefore to make this opening O-shaped to obviate this problem.

Although the known apparatus has proved satisfactory when processing natural fibres, problems more particularly occur when processing artificial fibres or mixtures of natural and artificial fibres. There is a risk of static charging and as a result the broken thread end can be picked up by the pressure roller and forms lap. In addition, when processing such fibres, the pressure roller is made very dirty and this cannot generally be eliminated by the stripping roller.

A problem therefore exists of so constructing apparatus of this type so that broken threads can be reliably picked up and at the same time contamination of the pressure roller is prevented.

According to the present invention apparatus for the removal of broken threads in a drawing frame of the kind which has co-operating grooved and pressure rollers at the frame outlet comprises a suction tube into which a broken thread leaving the frame outlet can be sucked and which has an opening located approximately parallel to the axes of the rollers in the V-shaped outlet area thereof.

Thus in the apparatus according to the invention lap formation is reliably prevented, so that the aforementioned disadvantages associated therewith do not occur. The upper stripping roller can be eliminated, because all thread dust which falls when the thread leaves the drawing frame and is not embedded in the thread is now reliably removed by suction. Thread suction takes place directly at the point where the thread leaves the drawing frame and not, as hitherto, in the least favourable position 1 5 mm below this point. As the result of this aforementioned thread dust removal by suction, the stripping times are considerably reduced. In the case of lap formation, it is very difficult to reintroduce the cut off waste into the spinning process, so that expensive raw material wastage occurs.However, no problems are caused in this connection with waste materials from completely satisfactory thread suction.

It has also been found that less suction pressure is required for reliably taking up the broken threads than in the known apparatus with straight suction tubes, so that it is possible to work with a lower air output.

The invention can be performed in various ways and some embodiments will now be described by way of example and with reference to the accompanying drawings in which: - Figure 1 is a side view of a first embodiment with a plan view of the associated slotted link; Figure 2 is a front view of the embodiment of Figure 1 in which the slotted links are not shown; Figure 3 is a front view of a second embodiment; Figure 4 is a side view of a third embodiment; Figure 5 is a front view of the third embodiment; Figure 6 is a side view of a fourth embodiment; Figure 7 is a side view of a fifth embodiment; Figure 8 is a front view of the fifth embodiment; and Figure 9 is a front view of a sixth embodiment.

In the embodiment shown in Figures 1 and 2, each of two suction tubes 1, 2 is mounted in known manner on a resilient sleeve 3 on a suction channel 4. Each suction tube 1, 2 is held by a slotted link member 5, guidance being achieved in the latter by a guidance member 6 surrounding the suction tube level with link 5. The slotted link 5 is connected to a link rod 7.

The upper part 8 of each suction tube has a U-shaped construction, so that the suction tube opening 9 is approximately parallel to the axes 10, 11 of rollers 12, 13 and is located in the outlet area 14 of the rollers.

Roller 12 is a pressure roller which is in the form of a rubber roller, whilst roller 1 3 is a grooved roller, which is made from steel. The thread leaving the rollers is fed to spinning apparatus of well known kind (not shown) and takes up a conical discharge formation which occupies an outlet area in the manner shown in broken line 1 5 in Figure 1.

The centre 1 6 of the suction tube opening is located at the common tangent of the two rollers 12, 13 indicated by chain line 17. This common tangent 17 and consequently also a large part of the cross-section of the suction tube opening is positioned above the outlet area of the outgoing thread 15.

In the embodiment shown in Figures 1 and 2, the two suction tubes 1,2 of adjacent drawing frames are interconnected at the apices 1 8 of their upper parts 8 and each of the tubes is guided in a slotted link and can therefore be swung down jointly from the discharge area of rollers 12, 13.

In the embodiment shown in Figure 3, the two suction tubes 1,2 have a shoulder 19 provided at apex 18 and which is guided in a single slotted link 5 (not shown). As a result, the two suction tubes 1,2 are guided jointly in a single slotted link.

Figure 3 also shows that each suction tube opening 9 is axially arranged with a spacing of T of the pressure roller length, this spacing being indicated by reference numeral 20.

According to Figures 4 and 5, the suction tubes comprise nested tube portions 21,22, 23, 24.

Compared with the embodiments of Figures 1 to 3, this makes it much easier to bend the tubes.

Each suction tube according to Figures 4 and 5 is individually guided in a slotted link 5, so that the tubes can be swung down individually.

In the embodiment shown in Figure 6, the suction tube comprises three tube portions 25, 26, 27. In the embodiment according to Figures 4 and 5, the lower tube portion 21 is straight over its entire length, whereas in the embodiment of Figure 6 the lower tube portion 25 is bent in its upper part. Thus, compared with the embodiment of Figures 4 and 5, there is no need for tube portion 22.

In the embodiment shown in Figures 7 and 8, the two suction tubes 1,2 comprise two tube portions 28, 29 on which is mounted a T-shaped head 30. The two T-shaped heads 30 are interconnected by a cross-member 31, which is solid. Each suction tube 1,2 is once again guided in a slotted link 5 (not shown).

In the embodiment of Figure 9, a common suction tube 32 is associated with two adjacent drawing frames. A T-shaped head 33 is mounted on suction tube 32 in such a way that, unlike in the preceding embodiments, not only the suction tube opening 9, but also the complete head 33 is tangential to roller 12, 13.

It is also possible to associate two oppositely direction suction tube openings 9 with each drawing frame, so that the outgoing thread 1 5 is taken up to the left or right by a suction tube opening.

Claims

1. Apparatus for the removal by suction of broken threads in a drawing frame of the kind which has co-operating grooved and pressure rollers at the frame outlet, comprising a suction tube into which a broken thread leaving the frame outlet can be sucked and which has an opening located approximately parallel to the axes of the rollers in the V-shaped outlet area thereof.

2. Apparatus as claimed in claim 1 in which the centre of the suction tube opening is arranged in approximately the vicinity of the common tangent of both rollers above the thread outlet area.

3. Apparatus as claimed in claim 1 or claim 2 in which the suction tubes for two adjacent drawing frames are interconnected and each of their upper parts has a substantially U-shaped construction.

4. Apparatus as claimed in claim 3 in which the upper parts are interconnected at their facing apices.

5. Apparatus as claimed in claim 3 or claim 4, in which each of the two interconnected suction tubes is guided in a slotted link which, permits them to be swung down from the rollers.

6. Apparatus as claimed in claim 3 or claim 4, in which the two interconnected suction tubes have a shoulder guided in a slotted link which, permits them to be swung down from the rollers.

7. Apparatus as claimed in claim 6 in which the shoulder is fixed to the interconnected apices.

8. Apparatus as claimed in any one of the preceding claims in which the suction tubes comprise nested portions.

9. Apparatus as claimed in claim 1 or claim 2 in which the suction tubes of two adjacent drawing frames have T-shaped heads interconnected by means of a cross-member.

10. Apparatus as claimed in claim 1 or claim 2 in which a suction tube is associated with two adjacent drawing frames.

11. Apparatus as claimed in claim 10 in which the suction tube has a T-shaped head.

12. Apparatus as claimed in any one of the preceding claims in which the suction tube openings are arranged axially with a spacing of approximately X of the pressure roller length.

13. Apparatus as claimed in any one of the preceding claims in which two oppositely direction suction tube openings are associated with each drawing frame.

14. Apparatus substantially as described herein with reference to and as shown in Figures 1 and 2, Figure 3, Figures 4 and 5, Figure 6, Figures 7 and 8 and Figure 9 of the accompanying drawings.