US3367371A - Device for introducing a weft thread into a shed - Google Patents

Description

6, 1968 H. P. VAN MULLEKOM 3,367,371

DEVICE FOR INTRODUCING A WEFT THREAD INTO A SHED Filed Feb. 16, 1966 3 sheets'sheet 1 Feb. 6, 1968 H. P. VAN MULLEKOM 3,367,371

DEVICE FOR INTRODUCING A WEFT THREAD INTO A SHED 5 Sheets-Sheet 2 Filed Feb. 16, 1966 1968 H. P. VAN MULLEKO'M 3,367,371

DEVICE FOR INTRODUCING A WEFT THREAD INTO A SHED Filed Feb. 16, 1966 Ksheetsfihcet 5 FIGQ United States Patent 3,367,371 DEVICE FOR INTRODUCING A WEFT THREAD INTO A SHED Hubert Peter van Mullekom, Deurne, North-Brabant, Netherlands, assiguor to N.V. Machinefabriek L. to Strake, Deurne, North-Brabant, Netherlands, a Dutch company Filed Feb. 16, 1966, Ser. No. 527,654 Claims priority, application Netherlands, Feb. 23, 1965,

5-2,271 6 Claims. (Cl. 139127) ABSTRACT OF THE DISGLOSURE A device for introducing a weft thread into a shed, comprising a nozzle for blowing a stream of air, a passage having an outlet end adjacent the stream of air issuing from the nozzle, and having an inlet end into which secondary air is drawn by the jet action of the stream of air issuing from the nozzle in order to entrain an end of the weft thread presented at the inlet end of the passage, and to carry such end of the thread through the passage to a point at which such end of the thread is entrained by the stream of air issuing from the nozzle to cause a length of the weft thread to be drawn through the passage and blown into the shed, a needle having a notch in its point, and mechanism for guiding the needle for axial movement from one extreme position in which the needle is retracted out of the path of the weft thread entering the passage, through an intermediate position in which the notch in the point of the needle engages a weft thread at the inlet end of the passage, to another extreme position in which the needle extends into the passage and presents the weft thread inside of the passage.

Background 0 the invention The invention relates to a weft inserting device, provided with a jet nozzle for blowing a weft into a shed by means of air under pressure, which weft inserting device is provided with a passage for the thread, which comes from a thread package.

Such weft inserting devices for looms are known per se.

When the production speed of such looms is increased the holding of the thread for its conveyance becomes more critical. It can happen that the thread will lag with respect to the other moving parts of the loom. Such a lag is inadmissable.

Summary 0) the invention The object of the invention is to improve a weft inserting device in such a manner that the thread can be launched very quickly.

According to the invention this is attained in that a needle extends into a passage, which needle at its point is provided with a notch, which is adapted to receive a thread running in front of the point of said needle, which needle is adapted to move axially between two end positions, while in one end position the thread is positioned within the passage with the point of the needle near a jet nozzle and in the other end position at the end of the passage opposed to the jet nozzle the needle is entirely free from the path of the thread to the passage.

The invention makes it possible to present the leading part of the thread on which air under pressure of the jet nozzle acts firstly in the shape of a loop to this air under pressure, so that the air has a good grip on this leading end.

Moreover the invention has the advantage that the thread can be more quickly supplied to the jet nozzle and 3,367,371 Patented Feb. 6, 1968 begins to move before the secondary air, which is sucked to the passage by the jet action has a sufiicient speed to propel the thread through the passage.

The invention can be also applied to a loom in which a shaft for sucking in a loop of a measured part of the thread is connected to the weft inserting device as known per se.

According to the invention the loom is constructed in such a manner, that the shaft is provided with an entrance opening for the needle, which entrance opening and the needle are positioned in such a manner with respect to the interior of the shaft, that upon the movement of the needle its point crosses the path of the thread in front of the mouth of the shaft. The leading end of the thread remaining in the shaft is then immediately presented to the blowing device through the passage by the action of the needle.

A practical embodiment according to the invention is attained in that the passage for the thread is situated between a jet nozzle and the mouth of the shaft, which passage is shaped in such a manner that its cross section decreases from the mouth of the shaft in the direction towards said jet nozzle.

It is preferable that the entrance opening for the needle at least at the mouth of the shaft be positioned in a plane of symmetry between the small sides of the cleft-like shaft opening and that the needle, which is positioned in this plane of symmetry of the interior of the shaft, make an acute angle with the axis of the passage for the thread.

Brie) description of the drawings FIG. 1 is an axial section through a known type of blowing device, which in accordance with the invention is provided with a needle for pushing a weft into a passage through which air is drawn by the blowing device.

FIG. 2 is an axial section through a blowing device provided with a shaft for sucking up a loop in a measured length of a thread and provided with a needle for pushing into a passage in the blowing device a part of the thread which remains within the shaft.

FIGS. 3-7 are diagrammatic representations in plan view of the blowing device according to FIG. 2 in which the successive steps for presenting a weft are indicated.

FIG. 8 is a perspective view of a loom embodying a weft-inserting device according to the invention.

FIG. 9 is a front elevation of the needle and its mounting shown in FIG. 1.

FIG. 10 is a fragmentary plan view of the device shown in FIG. 2, with the needle in the position shown in FIG. 5.

Description of the preferred embodiments The invention will be described first with reference to FIG. 1, which is a simplified illustration of the device shown in FIG. 2, and in which some parts have been omitted and others have been rearranged to facilitate an understanding of the operation of the parts shown in FIG. 1.

In a loom embodying a weft-inserting device according to the invention use can be made of device of the type described in application Ser. No. 506,047, filed Nov. 2, 1965, which device includes a line 1 for air under pressure, which line comes from a control valve and debouches into a chamber 2 of an annular aperture 3 of a jet nozzle. The aperture 3 surrounds the wall which encloses the passage 4. When air under pressure streams out of the jet nozzle secondary air will be sucked through the passage 4. A thread which is presented at the rear side 5 of the passage 4 as hereinafter described will be drawn through the passage 4 as a result of the stream of secondary suction air and further the stream of secondary air will carry the thread into the primary air, which streams out of the jet nozzle, whereafter the thread is conveyed into the shed by the primary air. The insertion of the thread as well as its conveying through the passage 4 can be accelerated by means of a needle 6. At its point the needle 6 is provided with a notch 7 so that a thread 8 which runs in front of the needle 6 and behind the passage 4 will be engaged by the notch in the point of the needle.

By means of a screw 9 the needle is adjustably mounted to a slide 10, which fits in a guide 12 by means of a slide block 11. 13 is a part of a driving mechanism for the slide block, e.g. an eccentric driven rod which moves the slide block 11 and needle in synchronism with the operation of the loom as hereinafter described. The driving of the slide block 11 and the control of the valve in the line 1 are synchronized.

During the moment, in which the valve in the line 1 is opened or shortl before this moment the needle moves into ti e passage 4. During this movement a thread which comes from a thread package 25 is inserted in the shape of a loop into the passage by means of the notch 7 at the point of the needle. The needle 6 has sufficient clearance within the passage 4 that the remaining ends of the thread 8 can extend along the needle 6 Whereas there is still sufficient clearance for the secondary air.

The insertion of the thread by means of the needle is also possible when the weft inserting device is provided with a shaft for temporarily storing a measured length of a thread, which shaft can be considered as the presenting device for the thread behind the blowing device.

Such a weft inserting device is shown in FIG. 2 and the line 14 debouches into a chamber 2a, which chamber merges into an annular jet nozzle 3a. A mixing tube 14 is mounted at the down stream side of the jet nozzle 3a in which mixing tube primary air, which streams out of the jet nozzle, is mixed with secondary air which is supplied from the shaft 15 through the passage 4a. The shaft 15 is provided with a suction opening 17 which can be closed by a valve 16 as described in said application Ser. No. 506,047 and in US. Patent No. 3,024,814. When the valve 16 is opened a measured length of the thread is sucked into the interior 18 of the shaft. When the valve 16 is closed air under pressure streams out of the jet nozzle 3a and secondary air is sucked into the interior 18 of the shaft through the opening 19 of which the valve 20 meanwhile is opened. The passage 4a is connected to the front end 21 of the shaft. The shaft is provided with an entrance opening 22 for a flexible needle 6a near the front end of the shaft. The needle 6a is mounted in a slide 110, which runs in a guide 12a mounted on the shaft 15. The interior of the shaft has a cleftlike cross section. The entrance opening 22 for the needle 6:: is positioned in the plane of symmetry between the small sides of the cleft shaped interior of the shaft. The needle 6a makes an acute angle with the axis of the passage 4a which is situated between the front end 21 of the shaft and the jet nozzle 3a. The passage 4a possesses a cross section which decreases from the front end 21 of the shaft in the direction of the jet nozzle 3a.

A thread 23 is drawn from a thread package 25 by means of continuously driven rollers 24 (FIG. 8). An auxiliary shaft 26 is positioned laterally of the shaft 15. This auxiliary shaft has the function of temporarily sucking up a loop in the thread 23 when the length of the loop in the thread within the shaft 15 has obtained its predetermined size and a thread clamp 27 has been closed by mechanism which operates the clamp 27 in synchronism with the operation of the loom as described in US. Patent No. 3,024,814. The closed position of this thread clamp 27 is indicated in FIGS. 6 and 7.

The thread, which has been inserted in front of the shaft by the pushing member 30 as hereinafter described,

runs into the interior of the shaft 15 over a guide roller 28. The thread clamp 27 and the valve 16 of the suction opening 17 are opened and the valve 20 to the air entrance opening 19 is closed in FIGS. 3, 4 and 5. In these figures a loop in the thread 23 is sucked into the shaft 15 whereas that moment is indicated in FIG. 5 in which the loop has obtained its maximal length.

In FIGS. 3, 4 and 5 the leading end of the thread is clamped by a cutting and holding device 29 as described in application Ser. No. 506,047. The needle 6a is diagrammatically indicated. In FIG. 4 the needle 6a brings the notch 7 at its point into the path of the thread, which runs before the front end 21 of the shaft 15. When the needle 6a moves further in the direction towards the jet nozzle 3a a loop is formed in this part of the thread, as indicated in FIG. 5. The loop in the thread at the point of the needle is entirely formed when the needle 6a takes its position as indicated in FIG. 6 and the cutting and holding device 29 is opened, resulting in a releasing of the free end of the thread. At this moment the needle is already in the passage 4a. At the same moment the valve 16 of the suction opening 17 is closed and the valve 20 of the air entrance opening 19 is opened. Now the needle 6a is to be retracted, while the loop of the thread at its leadin end remains in the passage 4a. The jet nozzle 3a becomes operative at the same moment. This last situation is indicated in FIG. 7. When the jet nozzle 3a becomes operative the thread is drawn entirely out of the shaft 15 and is blown into the shed and thereby tensioned. When the reed has performed its beating action the thread runs thus through the mixing tube 14 and the passage 4a to the roller 28. When a new loop is to be sucked into the shaft 15 a pushing member 30 becomes operative and moves to engage the thread 23 and to push a loop of the thread into the space between the shaft 15 and the passage 4a, as described in application 506,047, in order to insert the tensioned part of the thread in front of the mouth of the shaft, upon which the thread clamp 27 is released and a new loop can be sucked into the shaft 15. At this stage, after a new loop has been sucked into the shaft 15, the position of the thread is as shown in FIG. 5 except that the free end of the thread does not run to the cutting and holding device 29 but instead runs through the mixing tube 14 into the fabric as hereinbefore described. At this stage the new loop of thread is cut off from the thread supply at a point between the roller 28 and the shaft 15, in the conventional manner as described in application Ser. No. 506,047 and in Patent No. 3,137,322, with the result that the free end of the thread supply remains clamped in the cutting and holding device 29, and the cut-off end of the thread falls in front of the inlet end of the passage 4a. In this way the new loop of thread in the shaft 15 is severed from the thread supply in the conventional manner. The new loop which is stored in the shaft 15 at this stage is the second part of an individual weft thread, and the first part of this individual weft thread is the part which has been woven into the fabric as hereinbefore described.

In FIGS. 3-4 only the first part of an individual weft thread is shown. Each individual weft thread, consisting of two parts or legs is to be woven into the fabric in a hairpin like manner as known per se. After a next thread has been inserted into the shed from the opposite side, the second part of the individual weft thread is to be blown into the shed in order to leave the individual weft thread in the fabric in a hairpin like formation. The insertion of the second part of the individual weft thread does not require any action of the part of the needle 6a, and therefore forms no part of the present invention and is not shown in FIGS. 35. After the new loop of thread in the shaft 15, which forms the second part of the individual weft thread, has been blown into the shed the shaft 15 and passage 4:: are empty. Then the pushing iember 30 is again advanced as hereinbefore described,

to engage the thread which extends between the roller 28 and the cutting and holding device 29, and to push a loop of the thread in front of the shaft 15, after which a new operation begins as illustrated in FIG. 3.

I claim:

1. A device for introducing a weft thread into a shed, comprising a nozzle for blowing a stream of air, a

. passage having an outlet end adjacent the stream of air issuing from the nozzle and having an inlet end into which secondary air is drawn by the jet action of the stream of air issuing from the nozzle in order to entrain an end of the weft thread presented at the inlet end of the passage, and to carry such end of the thread through the passage to a point at which such end of the thread is entrained by the stream of air issuing from the nozzle to cause a length of the weft thread to be drawn through the passage and blown into the shed, wherein the improvement comprises a needle having a notch in its point, and mechanism for guiding the needle for axial movement from one extreme position in which the needle is retracted out of the path of the weft thread entering the passage, through an intermediate position in which the notch in the point of the needle engages a weft thread at the inlet end of the passage, to another extreme position in which the needle extends into the passage and presents the weft thread inside of the passage.

2. A device according to claim 1 comprising a shaft extending from a point adjacent the inlet end of the passage, which is adapted to take up by suction a measured length of the weft thread in the form of a loop, and which has an opening that receives the needle and extends in such a direction as to guide the point of the needle toward the inlet end of the passage and into engagement with an end of a loop of weft thread which has been taken into the shaft.

3. A device according to claim 2 wherein the passage decreases in cross section from its inlet end toward its outlet end.

4. A device according to claim 2 wherein the shaft has a cleft-like interior, and the opening that receives the needle is so directed as to guide the point of the needle into the plane of symmetry between the small sides of the cleft-like interior of the shaft.

5. A device according to claim 4 wherein the opening that receives the needle is so directed as to maintain the needle at an acute angle with the axis of the passage.

6. A device according to claim 2 wherein the needle is driven by a reciprocating slide block mounted on the shaft.

No references cited.

HENRY S. JAUDON, Primary Examiner.

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