GB2037330A

GB2037330A - Jet Looms

Info

Publication number: GB2037330A
Application number: GB7942243A
Authority: GB
Original assignee: Zbrojovka Vsetin np
Current assignee: Zbrojovka Vsetin np
Priority date: 1978-12-15
Filing date: 1979-12-07
Publication date: 1980-07-09
Also published as: JPS55112338A; CS205624B1; CH642409A5; NL7908613A; GB2037330B; DE2947220A1; DE2947220C2

Abstract

Air jets 7, mounted on the sley 2, direct air through the reed 8 where it is deflected into the direction of picking by vanes 9 mounted on the confuser teeth 15. <IMAGE>

Description

SPECIFICATION A Method Of and a Device for Forming an Additional Stream of Air in a Guiding Comb The present invention relates to a method and a device for forming an additional stream of air in the guiding comb for supporting the weft thread during its insertion in air jet looms.

For air jet looms with reed space larger than 200 cm there is used an active guiding comb also called active confusor, i.e. the guiding comb is equipped with a device for forming an additional stream of air. Such a device for forming an additional stream of air is most often equipped with a system of additional timed nozzles, which are located at certain distances along the whole length of the guiding comb and are supporting the main stream of air thus carrying the weft thread through the opened shed. These additional timed nozzles are usually located in several special lamellas in the guiding comb and pressure air is supplied through the air vents formed in these lamellas.

The disadvantage of such arrangements, for forming the additional stream of air, is especially the necessity for very small diameter of the nozzles as well as of small dimensions of air vents in lamellas, the production of which is very laborious and too costly. The last but not least problem is, that such an arrangement of nozzles is sensitive to contamination, as even small particles of impurities disturb the correct function of the additional nozzles. From the economical point of view the air consumption is not competitive as well as the resistance of the tubing for air guidance and air pressure losses are considerable.

The task of the present invention is to overcome the above mentioned disadvantages.

According to one aspect of the present invention there is provided a method of forming an additional supporting stream of air in the guiding comb of an air jet loom, wherein an additional stream of air is directed through the reed and then into the direction of weft insertion, through the opened shed.

According to another aspect of the present invention there is provided a device for carrying out the above method, comprising a distribution tube located between the reed and harness and provided with at least one nozzle, a slotted orifice of which is directed towards a directing surface, formed on the rear part of the lamella, in the form resembling turbine guide vane.

The advantages of the device according to the present invention are considerable. First, it is not necessary to supply air by elastic hoses, from the sley up to the additional nozzles, as it is used in the former arrangements.A further advantage is that it is possible to give sufficient dimensions to the distribution tube, as well as to the nozzles, because it is not necessary to use too high air pressure for acceleration of the air stream. Thus it is possible to use only more efficient blower as a source of pressure air.

Also advantageous is that through the nozzles passes a considerable amount of air, so that there is not a danger of clogging the nozzles.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a side elevation of the sley, reed and arrangement of the additional nozzle for supporting the air stream in the guiding comb, in the position when the shed is open and in the moment of additional streaming; Fig. 2 is a detail of the embodiment illustrated in Figure 1, especially the part for additional streaming in the guiding comb and a part of the reed; and Fig. 3 is a section taken on the line A-A of Figure 2.

According to Figure 1, a guiding comb 5 is tilted to the reed 1 in the moment of the opened shed (such an arrangement is more fully described in the Czechoslovak Patent Specification AO 1 80 260). In this position the reed 1 and the guiding comb 5 is illustrated by heavy lines. The position of the reed 1 and guiding comb 5, in the moment of weft thread preparation, is illustrated by light lines.

A device for forming an additional air stream includes a distribution tube 6, which is firmly fastened on to a batten by means of brackets 6a, between the reed 1 and a harness 10. The distribution tube 6 is provided with at least one nozzle 7, although it is more effective to locate several nozzles 7 along the guiding comb. Each nozzle 7 is rounded in its upper part 16 for better penetration into the warps 17 and its slotted orifice 11 can be longer than 10 millimeters and several millimeters in width. The nozzles 7 are mounted on the distribution tube 6 in such a way that their slotted orifice 11 is directed towards the effective directing surface 13, which is formed on the rear part 9 of the lamella 14. These directing surfaces 13 are formed only on the rear parts 9 of lamellas 14 and are situated opposite to the slotted orifices 11 of the nozzles 7.The form of the directing surfaces 13 on the rear part 9 of the lamella 14 resembles the form of a turbine guide vane.

The device as specified above operates as follows: From an unillustrated source, air is supplied by the distribution tube 6 to the nozzle 7 and is jetted out through the slotted orifice 11. In the weft insertion position, of both the reed 1 and guiding comb 5, air is streaming through the gaps 12, among the dents 8 of the reed 1 and towards the directing surface 13, by which it is directed into the weft insertion channel 15, formed by the lamellas 14, where the supporting stream of air is formed by the lamellas 14, where the supporting stream of air is formed to help weft insertion into the opened shed. The additional supporting stream of air, formed in this way, is stopped during the beat-up motion, of both the reed 1 and guiding comb 5, in the position as illustrated by light lines in Figure 1. Additional streaming is renewed again when both the reed 1 and guiding comb 5 return back, into the weft insertion position, as illustrated by heavy lines in Figure 1.

Claims

1. A method of forming an additional supporting stream of air in the guiding comb of an air jet loom, wherein an additional stream of air is directed through the reed and then into the direction of weft insertion, through the opened shed.

2. A device for carrying out the method according to the claim 1, comprising a distribution tube located between the reed and harness and provided with at least one nozzle, a slotted orifice of which is directed towards a directing surface, formed on the rear part of the lamella, in the form resembling turbine guide vane.

3. A method of forming an additional supporting stream of air in the guiding comb of an air jet loom, substantially as hereinbefore described with reference to the accompanying drawings.

4. A device for forming a method of forming an additional supporting steam of air in the guiding comb of an air jet loom, substantially as hereinbefore described with reference to the accompanying drawings.