US3430664A

US3430664A - Looms

Info

Publication number: US3430664A
Application number: US625480A
Authority: US
Inventors: Derrick Walter Shimwell
Original assignee: Weaving Research & Textile Com
Current assignee: Weaving Research & Textile Com; Weaving Research & Textile Commission Agents Ltd
Priority date: 1966-03-30
Filing date: 1967-03-23
Publication date: 1969-03-04
Anticipated expiration: 1986-03-04
Also published as: GB1183934A; BE696348A; CH457313A; DE1710380A1; ES338630A1

Description

I March 4, 1969 D. w. SHIMWELL LOOMS I of 4 Sheet Filed March 23, 1967 a {nvenfor March 4, 1969 D. w. SHIMWELL LOOMS Sheet Filed March 25, 1967 March 4, 1969 D. w. SHIMWELL 3,

LOOMS Filed March 23, 1967 Sheet 3 of 4 I nvenlor By Q 7 b A lornefi March 4, 1969 w. SHIMWELL 3,430,664

LOOMS Filed March 25, 1967 Sheet 4 of 4 United States Patent 3,430,664 LOOMS Derrick Walter Shimwell, Jurby, Isle-of-Man, assignor to Weaving Research & Textile Commission Agents Limited, a British company Filed Mar. 23, 1967, Ser. No. 625,480 Claims priority, application Great Britain, Mar. 30, 1966, 14,100/ 66 US. Cl. 13912 21 Claims Int. Cl. D03d 47/34 ABSTRACT OF THE DISCLOSURE In a needle loom in which weft yarn is supplied from stationary packages to oscillating weft inserting means to be inserted into warp sheds, a reservoir in which the weft can be temporarily stored during its passage from said supply to said inserting means, wherein a reservoir for weft yarn is provided for at least one of the spears or the like, and a gas jet is positioned to blow weft yarn into. the reservoir from a supply package, the arrangement being such that weft yarn can be drawn from the reservoir by the spears as and when needed during running of the loom.

Description of invention This invention relates to looms in which the weft is not carried in the form of pirns or cops by shuttle but is supplied from stationary packages and is inserted through the warp shed by means of, for example, spears or rapiers.

A loom of this type can insert weft yarn at a higher speed than the conventional fiat shuttle loom but the weft yarn is only in intermittent demand. For example, if the weft is inserted by spears from either side of the cloth the intermittent demand causes plucking of yarn from the supply packages and the yarn is only drawn intermittently from the supply packages or cones. Furthermore, at some points in the laying cycle, the point at which laying of yarn begins is remote from the supply package and the yarn is laid at a point where the spear is travelling fast causing high yarn tension which acts to augment the effect of plucking of the yarn from the supply package. A combination of these two factors has been found to be a cause of weft breakage.

A loom of the spear type in accordance with this invention has a weft reservoir for one, or normally each, spear into which weft yarn is blown from a supply package by a jet of, for example, air and from which the yarn may be drawn by the spears as and when needed.

The pressure of the air issuing from the jet may be adjusted so that the yarn is drawn from the supply package into the reservoir at a substantially constant rate without plucking so that the tension in the weft yarn will thus be substantially reduced, allowing weaving at higher speeds and with less yarn breaks than has been the case hitherto. The yarn is then drawn from the reservoir intermittently by the spears and for each laying cycle the feed of weft yarn to the reservoir from the supply packages will approximately equal the length of yarn drawn from the reservoir intermittently by the spears. For example, if single pick cloth is being woven with the spears laying yarn only on every alternate movement across the cloth, the rate of supply of weft to the reservoir which occurs during both movements, has to approximate to half that at which the spears take-up yarn from the reservoir during their laying movement. Of course the loom can also weave double pick cloth when the demand for weft will be doubled and an increase in air pressure required.

The reservoir is conveniently in the form of a tube, the diameter of which may depend on the range of yarns being woven, and the pressure of air blown into it is also ice variable to suit the weight of yarn. In one typical example for jute hessian yarn the reservoir is 10 to 12 inches long, diameter, and the air pressure is approximately 7 to 8 lbs. per square inch.

The air blowing into the reservoir is conveniently released from a hole or holes through the wall of the reservoir or at the outlet end thereof so that the yarn is not blown out from the reservoir to the spears when this is not required.

A single outlet hole is preferred and a cover may be provided to allow air only to pass outwardly from the tube, the cover which is akin to a flap valve closing to prevent air entering when a threading-up operation is taking place.

In practice it is very difficult to arrange for the air et to supply the exact amount of yarn needed to the reservoir as, for example, the width of the cloth can vary or the corrugations of the weft may vary. This difliculty may be overcome by arranging for the air jet to supply slightly more weft yarn to the reservoir than the expected demand and then providing a passage or passages, at the inlet end of the reservoir to allow the incoming air jet to be spilled-back when the length of yarn in the reservoir is sufficient to create a back-pressure overcoming the pressure of the incoming air. This has the effect of cutting down the quantity of yarn being fed to the reservoir if there is an excessive amount therein. As the excess is used up the normal feed will automatically be resumed.

An air jet nozzle may also be present at the outlet end of the reservoir or between the reservoir and the spear to blow the weft yarn to the spear head. This jet is preferably only operative as and when the spear is laying yarn and will not operate for the remaining portion of the spear cycle. It will normally only be used with heavy yarns such as jute, sacking weft and hard fibre yarns. An additional nozzle may be positioned at the outlet of the reservoir to facilitate threading-up of the spear.

If the reservoir is employed with a loom in which the spears are reciprocated in a straight line, means such as the linkage described in the specification of our U.S. Patent No. 2,860,667 may be provided to take-up the slackness of the weft yarn which occurs during part of each cycle of spear movement. In such a case the reservoir may either be located between the supply package and the first pivotal link or it may be carried by, or from, one of the links.

If the reservoir is employed with a loom such as that forming the subject of our co-pending US. application Ser. No. 625,479 then no linkage is needed as the weft yarn is being woven in an arc and may be fed from a point (for example, the outlet of the reservoir) at approximately the centre of the arc.

The invention will now be further described by way of eiilample with reference to the accompanying drawings in w ich:

FIGURE 1 is a sketch illustrating the use of an air fed weft reservoir with a spear loom of the type forming the subject;

FIGURE 2 is a detail of the air escape hole at the reservoir outlet;

FIGURES 3-6 are diagrams illustrating the use of a weft reservoir with oth r typ s of spear looms;

FIGURE 7 is a sketch of an alternative form of weft reservoir; and

FIGURE 8 is a section outline VIIIVHI of FIG- URE 7.

Referring to FIGURE 1 the loom comprises two curved weft inserting needles, hereinafter called spears, 2, 4 each carried at the end of an arm 6 or 8 respectively. The arms are joined and are mounted for arcuate movement about a common shaft 10. On oscillation of the shaft the spears are caused to move in an arc in the same path and to lay weft in separate sheds (for further details of the operation of the loom reference should be made to the specification of our co-pending U.S. application Ser. No. 625,479). It will be appreciated that FIGURE 1 omits all details of the loom with the exception of those necessary to the proper understanding of this invention. Also for convenience a reservoir is only shown for the left hand spear 2, a similar reservoir is present in practice for the weft fed to the right hand spear 4.

The weft supply for the left hand spear 2 comprises two tag-ended cones 12, mounted within a shield 14. A weft reservoir 18 in the form of a polythene tube of about /4" to 1" diameter, is attached to the shield 14 and yarn is drawn from one of the cones through the inlet of the reservoir.

The tube 18 is pivotally mounted at its inlet end by means not shown in the sketch and is pivotally connected at its outlet end by an outlet elbow 22 to a pipe 24 which extends along the length of the arm 6 and connects with a further pipe or passage 26 extending along the spear and terminating at the spear head 28.

A source of compressed air is connected through an adjustable reducing valve 30 through a pipe 32 to a nozzle 34 which is positioned to be open through the wall of the inlet tube 20 to blow a jet of air through the inlet 20 into the reservoir. The jet is continuous and acts to draw the weft yarn into the reservoir where it accumulates in a number of coils indicated at 36 (FIG. 7).

The weft is laid by the spears intermittently and so the demand for weft yarn to be drawn from the reservoir is intermittent. However due to the accumulation of yarn in the reservoir the intermittent demand is not transmitted to the cones and yarn is drawn therefrom without significant or abrupt changes in tension. The pressure of the air jet through the nozzle 34 is adjusted so that the consumption of yarn is approximately equal the supply of yarn to the reservoir.

If too much yam accumulates in the reservoir, a back pressure is created thus reducing the efliciency of the air jet so that a reduced amount of yarn is introduced into the reservoir as and until the excess yarn has been used.

During normal running the air from the nozzle 36 escapes through an escape hole 38 in the outlet 22 of the reservoir (see FIGURE 2) and so does not act to feed yarn to the spear.

The hole 38 is provided with a hinged cover 40 (FIG. 2) which allows air to escape from the outlet 22 but which prevents air from being sucked into the outlet.

It has been found that with certain heavy yarn e.g. jute sacking weft and hard fibre, it is convenient to provide a second air jet to assist the passage of the yarn down the spear. This jet is fed from the source of compressed air through a reducing valve 42, pipe 44 and valves 46 operated by earns 48, to nozzles 50 open to the inner end of the spear passages 26.

As yarn is only laid by the spears at intermittent intervals, the jet is only operated at those intervals so as to prevent excess yarn billowing from the spear heads. This is achieved by the choice of a suitable shape for the earns 48 which are driven from a shaft 52 rotating in time with the operation of the other parts of the loom. As an example the pressure of the air at the nozzle 50 may be 20-30 lbs. per square inch the exact figure will in each case be determined by experiment.

As the point of connection of the reservoir to the arm 6 is adjacent the pillar 10 about which the arms 6, 8 oscillate (or it may be preferable to mount the elbow 22 directly above the pillar) and as the spears are moving in an arcuate path with the laying point at a constant distance from the pillar, it will be appreciated that the weft path is always substantially constant and hence the need for linkage to take-up surplus yarn during part of the cycle of spear movement is obviated.

When it is desired to thread-up the spears a valve (not shown) is opened to allow a strong blast of air to blow through a nozzle 54 at the end of an air pipe 55, the nozzle connecting with the outlet elbow 22 after the escape hole 38 causing yarn to be fed from the reservoir and

passages

24 and 26 to the spear head, the grippers (not shown) at the spear heads being opened to allow the yarn to emerge. A good suction for the reservoir is achieved as the cover 40 for the escape hole closes to prevent air being drawn into the outlet by the jet.

In the arrangement illustrated in FIGURE 3, a reservoir tube 60 is located at each side of a spear loom (only one side being shown) and yarn is fed into the reservoir from a supply cone 62 by an air jet 64. The yarn then passes along pipes connected as

pivotal links

66, 68 for the purpose of the taking up surplus of yarn as described in the specification of our U.S. Patent No. 2,860,667. The yarn is then fed to the inner end of a spear 70 reciprocating in a straight line path. The yarn may be assisted in its passage through the links by a second air jet 72.

Air can escape from the reservoir either at the inlet if this is found to be necessary or through holes 74 in the side of the reservoir tube adjacent the outlet end.

For details of the construction and operation of a loom having spears moving in a straight line path reference may be made to the specification of our U.S. Patent No. 2,816,576.

The embodiment shown in FIGURE 4 differs from that of FIGURE 3 only in that the reservoir tube is bent through 180 allowing for a more compact arrangement.

If desired the reservoir tube 60 can be carried by or can replace the link 66 and such an arrangement is shown in FIGURE 5.

As shown in FIGURE 6 the

arms

66, 68 are replaced by a single arm 75 to control the weft and remove the yarn from the reservoir in a more uniform manner. The reservoir 60 is located between the eye 76 Where the weft yarn engages the spear 70, and the cone 62.

It will be appreciated that the tension of yarn being drawn from a cone tends to increase as the diameter of the cone diminishes. It is envisaged that if necessary the pressure of the jet at the inlet end of the reservoir could be varied as the cone size decreases.

As an alternative the weft yarn reservoir shown in any one of FIGURES 1-6 could be of the form shown in FIGURES 7 and 8. This with reservoir 80 is rectangular in section as can be seen in FIGURE 8 and has a dimension at the inlet 20 not significantly greater than that of the tube 20 so as to limit the turbulence where the air jet enters the reservoir. The reservoir then increases in one dimension as seen in the drawing so as to allow the yarn coils to move down the reservoir without undue friction. The reservoir terminates at a tapering section connected to the outlet elbow 22. An air escape hole 82 is formed adjacent the outlet for the reservoir and again a flap valve 84 is provided to prevent air being sucked into the air lines.

The reservoir would normally be of rigid material with at least one wall 86 transparent.

It has been found that the use of the reservoir shown in FIGURES 7 and 8 considerably reduces the pressure of air needed properly to feed weft to the reservoir and hence results in a more eflicient performance.

I claim:

1. In a needle loom in which weft yarn is supplied from stationary packages to oscillating weft inserting means to be inserted into warp sheds, storage means in which the weft can be temporarily stored during its passage from said supply to said inserting means, wherein said storage means for weft yarn is in communication with said weft inserting means, a gas jet positioned to blow weft yarn into the storage means from said supply package, the arrangement being such that weft yarn can be drawn from the storage means by the weft inserting means as needed during weaving.

2. A loom as claimed in claim 1 in which said weft inserting means comprises a spear provided at each side of the loom and said storage means comprises a plurality of reservoirs whereby a reservoir is provided for each spear.

3. A loom as claimed in claim 1 in which each jet is connected to a source of compressed air.

4. A loom as claimed in claim 3 in which means are provided to adjust the pressure of the gas.

5. A loom as claimed in claim 2 in which each reservoir is in the form of a tube.

6. A loom as claimed in claim 2 in which each reservoir is rectangular in section and has an air inlet pipe.

7. A loom as claimed in claim 6 in which each reservoir has a section which tapers outwardly in one direction from a dimension at the inlet which is substantially equal to the dimension of the air inlet pipe.

8. A loom as claimed in claim 2 in which a yarn passage is provided between each reservoir and the head of its respective spear.

9. A loom as claimed in claim 8 wherein escape valve means are provided at the outlet end of each reservoir.

10. A loom as claimed in claim 9 in which each reservoir has only a single escape valve which is normally closed by a cover arranged to allow air only to pass outwardly from the reservoir and to prevent air from being sucked into the reservoir.

11. A loom as claimed in claim 8 in which a passage is provided at the inlet end of each reservoir to allow the incoming gas jet to escape when the reservoir is sufiiciently supplied with yarn to create a back pressure.

12. A loom as claimed in claim 11 in which a second jet nozzle is present between the outlet end of each reservoir and the spear head to assist in blowing yarn to the spear head.

13. A loom as claimed in claim 12 in which means are provided to energise the second jet only during those portions of the weaving cycle when the respective spear is laying yarn.

14. A loom as claimed in claim 2 in which a further nozzle is positioned adjacent the outlet of each reservoir to provide a jet which in use helps to suck yarn from the reservoir and to blow it to the spear head to facilitate threading-up of the respective spear.

15. A loom as claimed in claim 2 in which the spears are reciprocated in an arc with the reservoir extending radially from the center of the are so that the weft yarn path length remains substantially constant throughout weaving.

16. A loom as claimed in claim 15 wherein said reservoirs are mounted to a common pillar which is located at the center of the arc and on which two arms, each of which carries one of the spears, are pivotally mounted.

17. A loom as claimed in claim 2 in which the spears are driven in a straight line, means are provided to take up the slack in the weft yarn which occurs during each weft inserting cycle.

18. A loom as claimed in claim 17 in which the said means comprises for each spear two pivotal links, the reservoir being located between the supply package and the first pivotal link.

19. A loom as claimed in claim 18 wherein at least part of the reservoir is flexible and is mounted in a curved position.

20. A loom as claimed in claim 17 in which the said means comprises for each spear, two pivotal links, the reservoir being carried by one of the links.

21. A loom as claimed in claim 17 in which the said means comprises for each spear a single arm which engages the yarn between the reservoir and the spear.

References Cited UNITED STATES PATENTS 1,361,530 12/1920 Morris 139-123 2,860,667 11/1958 Shimwell 139-123 3,137,322 6/1964 Strake 139127 3,194,276 7/1965 Krukonis et al. 139-122 FOREIGN PATENTS 174,387 2/1961 Sweden.

HENRY S. JAUDON, Primary Examiner.

US. Cl. X.R.