US2199353A - Pneumatic thread holder - Google Patents

Description

April 30, 1940.

R. G. TURNER PNEUMATIC THREAD HOLDER Filed Sept. 30, 1937 2 Sheets-Sheet 1 Inventor Richard G. Tuvnev Atborneg April 30, 1940. R. G. TURNER PNEUMATIC THREAD HOLDER 2 Sheets-Sheet 2 Filed Sept. 30, 1937 Inventor Richavd G. Turnev Afiorney Patented Apr. 30, 194d um'rso STATESI'PATENT orrica PNEUMATIC THREAD HOLDER Richard G. Turner, Worcester, Mass, assignor to Crompton At Knowles Loom Works, Worcester, Mass., a corporation of Massachusetts Application September so, 1931, Serial No. 166,511

'20 Claims. (cl. 139-247) a This invention relates to improvements in thread holders for weft replenishing looms and it is the general object of the invention to provide pneumatic means for exerting a yielding tension on the weft ends extending from the bobbins awaiting transfer in the magazine,

In a well-known type of automatic loom the reserve bobbins are stored in a plurality of vertical stacks and are released one at a time for m transfer. As the bobbins descend their weft ends become slack, and should the slackness not be taken up there is danger that the threads will be broken by the lay. At the time of transfer the bobbin is subjected to a quick abrupt motion 5 which may be transmitted to the weft end, and in order to have correct thread control it is necessary to hold the thread reasonably taut but permit it to yield slightly to prevent breakage.

In my present invention I accomplish this 20 result by pneumatic means, using a vacuum system the intake of which is so placed as to draw the weft ends away from the magazine. When the supply of reserve bobbins is almost depleted there may be but one or two thread ends, and 25 the. thread holder must be capable under these conditions of holding a single thread. It is an important object of my present invention to provide a vacuum system having a channel the internal contour of which favors the retention of 30 a single thread.

It is a further object of my present invention to provide a vacuum system having a considerable friction area to be in contact with the thread and as set forth hereinafter I may accomplish 35 this result by the use of a rubber tube having at least one loop therein so that the thread in being drawn from the magazine toward the end' cordingly a further object of my present invention to provide an accumulator in the vacuum 50 system into which the cut ends can be sucked after the cutter has operated. The accumulator may have a screen or the like which prevents the threads from passing on'to the pump which creates the vacuum. When a glass accumulator is used it is found that although there is a stream of air passing through the accumulator yet the ends fall to the bottom and do not clog the screen. I prefer to employ a pump having an intermittent action so that during a portion of each beat of the loom air pressure in the accumulator is restored to normal, thereby permitting the weft ends to drop to the bottom of the accumulator without clogging the screen which protects the pump. The maximum strain on the weft ends is likely to occur on the pick immediately following transfer and in order that the threads may be subject to pneumatic pressure tending to hold them to assist in threading the shuttle eye I time the pump which supplies the vacuum so that it is operating at the time of'picking and during the flight of the shuttle, thereby assuring favorable shuttle threading conditions. Cutting at the temple occurs at front center, and the suction starts immediately thereafter to draw the thread awayfrom the shed before picking. This result I may accomplish by operating the pump to create a vacuum by the backward motion of the lay. I find that the previously described frictional contact between the weft ends and the friction surface has particular advantage when a' blast of air is employed to force the ends against the surface. At the time of transfer the thread end v of" the bobbin being transferred should be held sufliciently to permit threading of the bobbin, but on the next pick of the loom or shortly thereafter this thread end must be cut, at which time the thread should be drawn into the thread holder to be out of the path of the moving parts of the loom. The draft of airrushing through the bore of the thread holder holds the thread against one or more interior friction surfaces. the friction plus the draft of air being sufficient to prevent the weft end of the transferred bobbin from pulling out of the holder, but when the weft end is cut at some point in front of the thread holder the draft draws the thread away from the friction surface so that it can be sucked into the thread holder and away from the weaving instrumentalities of the loom. The combination of a friction surface and the blast of air therefore acts more or less as a one-way friction contrivance which releases the thread when the same should move into the thread holder but holds the thread against undesired movement toward the reserve bobbin.

The thread end of the transferred bobbin should be so disposed with respect to the air rushing into the thread holder as to be sucked into the latter. I find that by forming the thread holder with an interior convex surface and holding the thread of the transferred bobbin so that it contacts with the surface at some point beyond the intake of air, thereby causing the thread to lie partly or entirely across the stream of air, that satisfactory results are obtained. Only indifferent results can be expected when the thread is led to the thread holder and comes in direct contact with the orifice of the bore of the thread holder without having an opportunity to extend partly at least across the stream of air. I consider an important feature of my invention resides in exposing the thread in such a way as to cause it to extend into the stream of inrushing air, and I may accomplish this result by the aforesaid convex interior surface together with a hook or the like to hold the weft end at a point near the selvage of the cloth. When the parts are thus disposed the thread cutter in the temple severs the thread and leaves it in such a position that it is immediately acted upon by the stream of air and disappears very rapidly into the thread holder.

My invention further relates to a method forcontrolling weft ends which consists in exposing the weft thread as Just described so that it will be acted upon by the air immediately after being cut at the selvage, the thread being positioned to extend into the stream of air.

I find that static charges of electricity develop on the rubber thread tube which I use and have found that these charges can be dissipated by enclosing the rubber tube with metal, such as a sheath in the form of an enclosing pipe or the like.

It is a further object of my present invention to combine a pneumatic thread holder with a rocking or oscillating magazine for the reserve bobbins wherein the oscillation of the magazine produces relative motion between the weft ends extending from the reserve bobbins and also between the ends and the thread holder. With certain types of yarns there is a tendency for the thread ends to become entangled, or for one to lie over and hold another so that the latter cannot respond to the pneumatic action. The

, angular motion of the magazine causes a relative change of the thread ends with respect to each other and gives them an opportunity to separate and lie flat under the action of the inrushing air. This motion of the weft ends is not only angular with respect to the orifice of the thread holder but in some instances results also in relative longitudinal motion of the thread ends lying within the thread holder.

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts herein described and set forth.

- In the accompanying drawings wherein a convenient embodiment of my invention is set forth,

Fig. 1 is an end elevation of a portion of a loom showing my invention applied thereto,

Fig. 2 is a plan taken in the direction of arrow 2, Fig. 1,

Fig. 3 is a view similar to a portion of Fig. 2

with certain parts removed to illustrate the course taken by the thread as the lay starts tomove back immediately after a transfer,

Fig. 4 is a detailed end elevation of the intake end of the vacuum system as viewed from the center of the loom,

Fig. 5 is a plan view of the parts shown in a aieasss Fig. 6 is a vertical section on line i; of Fig. 5,

Fig. 'l is a vertical section on Fig. 2,

Fig. 8 is a vertical section througl'i the accumulator on line 8-8, Fig. i,

Fig. 9 is a detailed vertical section line of Fig. 8, and

Fig. 10 is a diagrammatic view showing iation of the weft end of a transferred the interior surfaces of the thread hi Referring to Figs. 1, 2 and 3 I have shown the loom frame l5 having a lay l3 which moves back and forth in the usual manner by means of a connector ll driven by a crank i3 of top shaft I9 which will ordinarily make one complete revolution for each beat of the loom. The lay has a single shuttle box 20, a binder 2i and picker 2! operative to pick the shuttle S out of the box. The cloth C as indicated in Fig. 3 is held out by a temple 23 which may be provided with a temple cutter 24 operating in the usual manner to cut the thread when the lay is at front center. In Fig. 3 the reed line indicated at 25 and the fell 26 of the cloth suggest that the lay has not yet reached frontcenter.

The loom may be provided with a reserve bobbin magazine M pivotally mounted on a fixed axis supported in any approved manner. The magazine includes a transferrer arm 3! to be actuated by the latch 32 and lay carried bunter II in the usual way during a forward beat of the loom, at which time one or another of the reserve bobbins B shown in the magazine will be transferred into the shuttle B. By means of mechanism not shown herein but set forth in my copending application Serial No. 129,245 the magazine is caused to rock in response to changes in the weaving shuttle. It is to be understood that the particular form of magazine shown herein supplies two distinct types of weft and that the loom is employed with drop boxes not shown but located at that end of the lay opposite box 20. While I have shown a rocking magazine of a multicolor type yet I do not wish necessarily to be limited to such a magazine in the use of my invention.

The matter thus far described may be of common construction, the automatic features being more particularly set forth in my aforesaid copending application. There will extend outwardly from the reserve bobbins in the magazine a plurality of weft ends W, as shown in Figs. 1

and 2, and my invention relates to control mech- .anism for these ends.

In carrying my present invention into effect I provide a vacuum pump designated generally at ll! and including a horizontal cylinder 4| in which reciprocates a piston 42 mounted on the forward end of a rod 43. The latter is attached to a lever 44 driven by a connector 39 attached to the lay, as shown in Fig. 1. The timing of the moving forward but prevents back flow when the piston is moving rearwardly.

Extending forwardly from the cylinder 4| is a vent the pump from blowing air forwardly in tube 41. When the piston is moving rearwardly, however, valve 48 opens so that a vacuum can be created in the tube II. It will be understood therefore that during the interval of time between front and back centers of the lay a vacuum will be created in the tube 1. v

An accumulator indicated generally at A in Figs. 1 and 2 comprises a hollow box like structure 58 intothe upper portion of which leads a tube 5!. This tube is connected to the tube ll by a flexible rubber hose 52. Extending diagonally across an upper corner of the accumulator is a screen 55 held in position by any appropriate means indicated as" lugs 56 to guard the tube 54, and the accumulator may also be provided with a cover 51 hinged as at 58 to the upper part of the structure 5%. As shown in Fig. 8 the underside of the cover may carry a soft rubber cushion 68 to eflect a substantially airtight seal between the cover and the box 50. Leading from the left vertical wall of the accumulator as shown in Fig. 8 is another tube 6! to which is fitted one end of a second rubber hose 52. Screen 55 lies between the tubes 5! and 3! to prevent passage of thread ends from one tube to the other.

A bracket th is secured to a fixedpart of the loom, such for instance as the stand which holds the magazine M. The bracket supports the accumulator as indicated in Fig. 2, and also extends outwardly and forwardly to terminate at a point beyond the magazine as at 51 where it has holding relation with a tubular intake 68.-

This intake is connected to an and of the rubber hose 62. I v

The intake 68 has an orifice 10 formed preferably at the end of a metallic tube H. The latter is short and extends into the rubber tube 62 around which lies a metallic sheath I3 supported by a foot 14 to the bracket 65 in such a way as to convey away from the rubber tube static electrical charges which I have found developed as the result of the inrush of air through the orifice 10. The sheath 13 is grounded to the loom frame by metallic connections.

In operation the weft ends W will be drawn by the attendant to the orifice, and as the lay moves rearwardly a vacuum will be created in the pump tending to draw said weft thread through the orifice Ill. The pump creates a vacuum on each backward stroke of the lay and draws the threads around the curved internal bore 15 of the tube 62, thereby establishing frictional contact between the weft ends and the rubber surface of the tube 62. When the loom calls for a transfer one of the reserve bobbins will descend and be transferred in the usual way by hammer 3|. Should tightness result in the weft end of the bobbin being transferred, said weft end will slide along the internal surface of the rubber tube I2 sufficiently to prevent breakage. As the lay moves rearwardly after transfer the pump will develop a vacuum which will be sufilciently high at the time of picking when the lay reaches top center or its mid-position when moving rearwardly to create a maximum inrush of air through the orifice 10 the effect of which is to hold all of the threads in the rubber tube against movement in a direction toward the magazine. In this way the vacuum assures threading of the shuttle as it travels away from the magazine on the first pick after transfer.

The thread of the transferred bobbin will extend from the holder into the warp shed and the orifice.

lie in front of a hook 90 on the lay when the latter is rearmost. As the lay advances the hook engagesand then moves the thread forwardly until the latter is caught over a second hook 9| fixed to the loom frame. Hook 9| is forward of the temple cutter and preferably set ahead of the thread holder, so that the weft end extends to the holder along a line inclined to and in front of the axis of tube ll. As a result of this relation the thread enters the orifice of tube H without touching the periphery of said orifice and proceeds to the convex curved surface 92,becoming tangent thereto at some point distant from The thread therefore lies across a part at least of the inrushing stream of air in tube H, as will be apparent from Fig. 10.

When the temple cutters severs the weft thread at'the selvage the draft of air strikes the thread at points a, a, Fig. 10, and draws it into the'tub'e II and on to the accumulator. The thread engaging surfaces of hook 9! are preferably polished and offer a minimum of resistance to the thread as it slides through the hook.

Figs. 4, 5 and 6 illustrate more particularly the form of thread guide which I have found successful in practice and includes a pair of upwardly extended wings 3d fiared as at hi to form, a downwardly converging mouth into which the weft ends are dropped by the weaver. Extending outwardly and forwardly is a trough 85 which leads to the bottom of the notch between the wings.

the thread will lie between the wings 80 and then be directed forwardly and downwardly to lie in the depression of the trough. In order to facilitate entry of the thread from the trough into the stream of inrushing air I notch the upper part of tube H as at 86, the notch extending generally in the direction of the trough 85. There will be a sag in the threads as suggested at 81 in Fig. 6 to permit a part of the thread to come within the range of the inrushing air.

Another feature of my invention resides in the particular form of magazine set forth for holding the reserve bobbin. By referring to the lower part of Fig. 2 it will be seen that the weft ends W approach the thread holder at different angles, and by referring to the upper left part of Fig. 1 it will be seen that the axis 30 of the magazine is so disposed that rocking of the magazine about its axis will create a change in the angular disposition of the weft ends not only with respect to themselves but also with respect to the intake mouth of the thread holder. The rocking of the magazine with the attendant motion of the weft ends therefore tends to correct any overlapping of the threads which may result from careless presentation of the threads to the thread holder mouth by the attendant. It will be noted that the effect of this rocking is most pronounced with the bottom bobbins as they approach transfer position, the result being that those bobbins about to be transferred are most likely to have their thread ends correctly disposed in the thread holder.

By referring particularly to Fig. 2 it will be seen that rocking of the magazine has the effect of movingthe lower forward weft ends rear- As viewed more particularly in Fig. 5

wardly to reduce the distance between the thread sive to the inrushing column of air the latter is able to spread the threads in a manner somewhat similar to a combing operation. Any thread extending from. a transferred bobbin which might temporarily be held under a reserve bobbin still in the magazine, and therefore not completely responsive to pneumatic pressure, has an opportunity to be released by the rocking of the magazine so that within a short interval after transfer the released thread can be drawn into the thread holder.

From the foregoing it will be seen that I have provided a thread holder and remover'for the weft ends of bobbin changing looms so constructed that a draft of air is employed not only to hold. the thread ends taut prior to transfer but also to suck the weft ends of transferred bobbins out of the path of moving parts of the loom. It will also be seen that I have provided an accumulator in which the weft ends can be stored to keep them from flying around the loom where they might be drawn into the warp shed. It will also be seen that where such yarns are used that might be effected by static electrical charges due to the blast of air I find means for grounding such charges so that the threads may respond to the air without being interfered with by static electricity. Again, it will be seen that in combining a friction surface located along a confined draft of air I provide what becomes effectually a one-way friction holder for the weft ends, acting to release the thread under action of the air when the thread is cut but serving to prevent the threads from being pulled out of the holder when the shuttle is being picked to carry the fresh reserve bobbin across the loom. Another important feature of my invention resides in providing means to dispose the thread so that a part of the same will extend across the draft of air, this result being accomplished as set forth herein by having an internal convex curved surface and requiring the thread to become tangent to this surface at a point removed from the point at which air enters the holder. I find also that any tendency for the first pick after transfer to lie too loosely in the warp shed is corrected by the tension exerted on this pick by the blast of air.

It will further be seen that in the particular form of magazine set forth herein the rocking of the magazine causes relative motion between the weft ends arid between the latter and the orifice 'of the thread holder the effect of which is to cause a more uniform distribution of the threads and the dislodgment of any thread from a transferred bobbin which may temporarily be under a thread extending from a reserve bobbin in the magazine. The rocking of the magazine also produces a relative longitudinal motion of the threads within the tube II and along the curved interior surface of the part 13.

duce a draft of air through said hollow member tending to draw the weft ends into said member, and a metallic sheath surrounding the member and grounded to convey away from the hollow member static electrical charges induced by the tion away from the reserve bobbins, and an electrical conductor to convey away from the member static electrical charges induced by the draft of air.

3. In a weft replenishing loom, a plurality of reserve bobbins from which extend weft ends, a rubber tube having an opening positioned to receive the weft ends, means to induce a draft of air in said rubber tube in a direction away from the reserve bobbins, and an electrical conducting member around the electrical tube to conduct away from said tube static electrical charges induced by the draft of air passing through said rubber tube.

4. In a weft replenishing loom, a plurality of reserve bobbins from which extend weft ends, a curved rubber tube having an open end positioned to receive the weft ends, means to induce a draft of air in said tube in a direction away from the reserve bobbins, and a metallic sheath around said tube grounded to the tube frame to convey away from said rubber tube static electrical charges induced by the draft of air.

5. In a weft replenishing loom, a plurality of reserve bobbins from which extend weft ends, a pump to create a vacuum, a pneumatic thread holder toreceive the weft ends from the reserve bobbins, a weft end accumulator connected to the pump and also to the thread holder and located between said pump and holder, a thread end after leaving its bobbin being drawn into the accumulator, and means in said accumulator to prevent weft ends from passing to the pump.

6. In a weft replenishing loom, a plurality of reserve bobbins from which extend weft ends,- a pneumatic thread holder to receive the weft ends, a pump to create a. vacuum, an accumulator for the thread ends connected to the thread holder and the pump and located between said pump and holder, the thread ends being drawn from the thread holder into the accumulator, and a screen in said accumulator permitting the passage of air therethrough, but preventing the passage of weft ends toward the pump.

'7. In a weft replenishing loom, a plurality of reserve bobbins from which extend weft ends, a

pneumatic thread holder to receive the weft ends, a pump acting periodically to create a vacuum, an accumulator for the weft ends and located between said pump and holder, means to connect the thread holder and pump to the accumulator, creation of a vacuum in the accumulator by the pump tending to draw the weft end from the thread holder into the accumulator, and the periodic interruption of the vacuum permitting the weft ends to fall to the bottom of the accumulator.

8. In a weft replenishing loom, a plurality of reserve bobbins from which extend weft ends. a pneumatic thread holder to receive the weft ends, a pump acting periodically to create a vacuum, an accumulator for the weft ends, hollow means connecting the thread holder to the upper part of the accumulator, other hollow means connecting the upper part of the accumulator to the ends tending to fall to the bottom of the accumulator away from the connection between the latter and the pump when said pump temporarily relieves the vacuum.

9. In a weft replenishing loom, a plurality of reserve bobbins from which extend weft ends, a pneumatic thread holder to receive the weft ends, means to cause a vacuum in the thread holder, an accumulator for the weft ends, a cover for the accumulator opening outwardly capable of being opened to permit removal of the accumulated ends in the accumulator, means to connect the thread holder to the accumulator and provide a closed path for the weft ends, and other closed means connecting the accumulator with the means to cause a vacuum, the latter drawing the weft ends into the accumulator and holding said cover in position to close the accumulator.

10. In a weft replenishing loom, a magazine to hold reserve bobbins from which extend weft ends, a pneumatic thread holder to receive the weft ends from the reserve bobbins, means to support the weft ends adjacent the thread holder, and periodically acting means to create a vacuum within said holder to cause an inrush of air periodically, thereby subjecting the weft ends on the support to repeated intermittent forces'tending to draw them into the thread holder, the weft ends being slackened between the periods when the vacuum is created.

11. In a weft replenishing loom, a plurality of reserve bobbins from which extend weft ends, a pneumatic thread holder for the weft ends having an intake facing the reserve bobbins, means to create a vacuum in said threadholder tending to draw the ends into said holder, means extending upwardly from the intake to guide weft ends toward the latter, and other means defining a horizontally extending support leading away from the intake and starting from a point adjacent the lower end of said means to guide the thread.

12. In a weft replenishing loom having a reserve bobbin to be transferred and from which extends a weft end, a thread holder having an internal bore into which the weft end extends, said internal bore having a convex area, means presenting a rubber surface on the convex area having contact with the weft end, and means to induce a vacuum in the bore to cause an inrush of air into the bore ina direction away from the means to transfer the bobbin, a pneumatic thread holder and thread remover into which the weft end extends, means to induce a draft of air along a given path within the holder, and means acting subsequent to the beat-up following transfer to cause the thread to lie in said thread holder along a line oblique to said given path after transfer.

14. 'In a weft replenishing loom having a reserve bobbin from which extends a weft end. a thread holder and thread remover having a passage therethrough following a given path, means to transfer the bobbin, means acting subsequent to-the beat-up following transfer to hold the weft end of the transferred bobbin in a position oblique with respect to said path, means to induce a draft of air within the holder along said path in a direction away from the bobbin, and means subsequent to transfer to cut the thread at a point between the thread holder and the cloth.

15. In a weft replenishing loom, a reserve bobbin magazine oscillating during loom operation and having extending therefrom weft ends which v are moved by the oscillation of the magazine, a pneumatic thread holder having an intake with respect to the thread holder to enable the inrushing air to effect uniform distribution of the weft ends with respect to the thread holder.

16. In a weft replenishing loom, an oscillatable magazinehavingarocking motion during loom operation and carrying reserve bobbins from which extend weft ends which are moved by the rocking of the magazine, a pneumatic thread holder having an orifice to receive the weft end, means to induce a rush of air into the orifice in a direction to draw the weft ends into said orifice and the thread holder, rocking of the magazine changing the distance betweenthe thread holder orifice and the ends of certain of the reserve bobbins in the magazine whereby the inrushing air is able to effect a relative motion between the weft ends longitudinally of the thread holder tending to effect an even distribution of the threads with respect to the thread holder.

17. In a weft replenishing loom, a magazine for reserve bobbins from which extend weft ends, a pivotal support for the magazine around which the latter turns angularly, angular motion of the magazine changing the position of the weft ends extending from the reserve bobbins, a pneumatic thread holder having an orifice to receive the weft ends, means to induce a draft of air into the orifice in a direction to draw the weft ends into the thread holder, angular motion of the magazine effecting a change of position of the weft ends with respect to the thread holder and an inrushing draft of air tending to effect a uni- .form distribution of the weft ends with respect to the thread holder.

18. In a weft replenishing loom having a magazine supporting a plurality of reserve bobbins from each of which a weft end extends, a pump to create a vacuum, a pneumatic thread holder which receives said weft ends extending from said reserve bobbins, and a thread cutter located adjacent the cloth selvage and operative subsequent to transfer, that improvement which comprises a weft end accumulator located between the pumpand the thread holder and connected to said pump and holder, said weft ends after severance at the selvage being drawn into said accumulator by said pump, and means in said accumulator to prevent said severed weft ends from passing to said pump.

19. In a weft replenishing loom having a-magazine supporting a plurality of reserve bobbins from each of which a weft end extends, a pump to create a vacuum, a pneumatic thread holder which receives said weft ends extending from said reserve bobbins, and a thread cutter located' adjacent the cloth selvage and operating subsequent to transfer, that improvement which comprises means to operate said pump intermittently to provide a pulsating air flow in said thread holder, a weft end accumulator located between the pump and the thread holder and connected serve bobbin from which a weft end extends, a pneumatic thread holder and thread remover having a passage therethrough following a given path, means to transfer the bobbin, means acting subsequent to transfer to sever the thread at a point between the thread holder and the adjacent cloth selvage, and means to introduce a draft of air within the thread-holder along said RICHARD G. TURNER.

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