US972349A

US972349A - Mechanism for weaving.

Info

Publication number: US972349A
Application number: US50643809A
Authority: US
Inventors: William Henry Drury
Original assignee: Individual
Current assignee: Individual
Priority date: 1909-07-06
Filing date: 1909-07-06
Publication date: 1910-10-11
Anticipated expiration: 1927-10-11

Description

W. H. DRURY. MEGHANISM POR WEAVING. APPLIGATION FILED JULYs,1909.

0 Patented 00a-11,1910.

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W. H. DRURY.

MEGHANISM FOR WEAVING.

APPLIGATION FILED JULY6,1909.

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W. H. DRUM.- MEGHANISM FOR WEAVING. APPLICATION .FILED JULY 6,1909.

Patented Oct. 11, 1910.

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WILLIAM HENRY DRURY, OF WALTHAM, MASSACHUSETTS.

MECHANISM FOR WEAVING.

Specification of Letters Patent.

Application filed July 6, 1909.

Patented Oct. 11, 1910. serian No. 506,438.

To all whom it may concern:

Be it known that I, VILLIAM HENRY DRURY, a citizen of the United States, residing at Waltham, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Mechanism for Weaving, of which the following is a specification.

The invention is an attachment to a machine for weaving textile fabrics, and causes the desired shed-formation to be made for each throw of the shuttle. It is useful in all styles of weaving, but relates more especially to figured weaving, and is intended to be substituted in place of the jacquard in all such work as ordinarily is done with the jacquard. It dispenses with the perforated cards, the revolving square or hexagon or Octagon prism called the cylinder, the griffs, needles, needleboard, coiled springs, spring-box pins, resting rods and the other usual accompaniments of the jacquard above the bottom board next Linder the jacquard hooks, including the usual cumbersome mechanism for operating the griifs and the cards. Substantially the same bottom board, cords, compart board, heddles and lingoes are used with the invention as with the acquard.

The invention can do anything the jacquard can do, is useful for all purposes for which the jacquard is used, and also has several useful advantages over the jacquard.

In figured weaving the principal objects of ythe invention are the following: l. To accomplish the minimum of wear on the warp threads and heddle cords, by providing means to keep continuously in the upper part of the shed during any desired number of consecutive picks such of the warp threads as are needed up thereat, and to keep the warp threads from making any movement down or up other than what is necessitated by the style of weave for the time being, so as to simplify the work of designing for patterns, diminish breakages and stoppages, improve the quality of goods produced and increase the durability of the heddle cords. 2. To accomplish increased rapidity of transformation of the shed from each pick to the next, by providing means whereby instantly at the end of each pick, before it is possible to throw the shuttle, the desired shed may be formed for the next pick, so that increased production of goods may be obtained within a given time and with given expenditure of power. 3. To eliminate the noise and most of the discomforts peculiarly incidental to figured weaving as ordinarily don-e, and to contribute to the health and comfort of weavers by affording them improved conditions of working. 4. To provide in a given bulk vastly more ample facilities for elaborateness of patterns than ordinary, by using therefor a design sheet less than 1/200 as bulky as, and more durable and reliable than, the ordinary means. 5. To provide in doing gured weaving simpler means than ordinarily used, by abolishing griffs and much cumbersome and complicated mechanism in ordinary use for working griffs and chains of cards, and by causing the shed-formation to be selected and made with mechanism which requires almost no power from the loom and only a single and slight connection with the working machinery of the loom.

The invention by which these objects are attained consists of special mechanism to make selection of the shed-formation at each pick, special mechanism to make the shed-formation .in conformity to such selection, and means to make selective connection between the shed-selecting and the shedforming mechanisms. The shed-selecting mechanism applies pneumatics to selection of the shed-formation, and consists of a design sheet or design valve and perforated and unperforated spots therein appropriated to representing the original textile design which has been planned for the predetermined pattern, and means to sustain and operate the design sheet in an air-tight chamber in which compressed air is maintained at desired degree of pressure. The shed-forming mechanism applies pneumatics to making the shed-formation in conformity to said selection, by means of small air hoists which correspond in number and in numerical order to the spots on the design sheet appropriated to representing the original textile design as before mentioned. With the neck cords of the loom harness running through the bottom board and attached to the lower ends of the piston rods of t-he air hoists, the warp threads are operated by the piston rods in a manner resembling that in which they ordinarily are operated by jacquard hooks. Selective connection between the shed-selecting and the shed-forming mechanisms' is made by means of small air tubes extending from the one to the other.

The invention is represented in the accompanying drawings.

Figure 1 is a vertical section of so much of the shed-selecting mechanism as consists of the design' chamber, whose front is at the left of the figure, the design sheet or design valve shown in a roll on a lower spool and in a smaller roll on an upper spool, the feedrollers which move the sheet or valve along, and the tube holder across whose surface the sheet or valve slides. The figure also shows at the right a View of short pieces of some of the small tubes which extend from the tube holder to the air hoists, and shows a view of some of the frame-work on the farther side of the chamber which supports the mechanism for actuating the feed-rollers. Fig. 2 is a view partly in section, and partly broken away, looking from the rear of the design chamber, the parts in section being on the

line

2, 2 of Fig. 1, the View inside the chamber being representative of the feed-rollers and spools, and the parts outside being representative of the mechanism connecting with said rollers and spools. Fig. 3 is a side elevation of the gearing by which said rollers are revolved, being another View of the gearing shown at the right in Fig. 2. Fig. 4 is a View of the mechanism on

line

4, 4 of Fig. 2, looking in the direction indi cated by the arrow near the top ofv that line, and this mechanism consists of the ratchets and the pawls and cam for operating the middle gear of Fig. 3. Fig. 5 is an enlarged detail view of one of the ratchets inside said chamber seen at the left in Fig. 2, which is .to hold the corresponding spool from turning when the design roll is not fastened to it,

4and this Fig. 5 shows how the shaft of the spool is held and how it may be removed. Fig. 6 is an enlarged horizontal section on

line

6, 6 of Fig. 1, looking down as indicated by the arrow pointing to that line. This view is partly broken away, and shows part of the desiOn roll, part of the spool and its shaft, another view of the ratchet last mentioned and part of the spiral spring which holds taut the design sheet or roll. Fig. 7 is a side elevation of the chamber which holds the cylinders of the air hoists, two of which are shown in full length where the side of the chamber is broken away. This figure shows portions of the small tubes which extend from said tube holder. The mechanism shown above the chamber is for adjustingthe openness of the shed by limit` ing the height to which the upper ends of the piston rods of the air hoists can rise. Fig. 8 is a horizontal section, looking downward, of four rows of the air hoists. The two top rows are on the line 8a, 8a of Fig. 7, and the two lower rows are on

line

8, 8

thereof. The dotted lines indicate the part of the chamber to which the bottom plate of the chamber is fastened. This figure also shows how the said small tubes connect with the air hoists. Fig. 9 is a view on the line 9, 9 of Fig. 2, looking in the direction pointed to by the arrow near that line. This shows the spiral springs for keeping the design roll tight on the spools. enlarged longitudinal section of one of the air hoists. Fig. 11 is a view, partlyin section, of a modification. Fig. 12 is a. longitudinal section of another modification. Fig. 13 is a cross section on

line

13, 13 of Fig. 10. Fig. 14 is a cross sect-ion on

line

14, 14 of Fig. 12. Fig. 15 is a cross section on

line

15, 15 of Fig. 10. Fig. 16 is a cross section on

line

16, 16 of Fig. 10. FiO. 17 is a cross section on

line

17, 17 of Fig. 12. Fig. 1S is a cross section on line 1S, 18 of Fig. 10. Fig. 19 is a cross section on line 1S), 19 of FiO'. 11. Fig. 0 represents a small piece of orzdinary design paper ruled into squares, with an S-harness sateen weave designed thereon as indicated by crosses, and the word It designed for the figure as indicated by small circles. This represents an original textile design. Fig. 21 represents a small piece of the design roll or design valve with the first upper 19 cross lines of said original design transferred thereto on the principle to be stated. Fig. 22 is a front elevation of the tube holder within the design chamber, the small idlers for holding the design roll againstthe feedrollers, the guides for guiding an end of the' design roll from one spool to the other, and means for holding some of the parts. Portions are broken away. This shows the surface across which the design roll slides, and four horizontal rows of small circular orifices into the small tubes before mentioned. These orifices are either opened by the perforations or closed by the unperforated spots in the design roll, either to admit or to exclude the entrance of air through the orifices.

Ordinary design paper sometimes is ruled into oblongs but oftener into squares. Each crosswise row of squares on the original textile design drawn on such paper represents al pick of the weaving and indicates where warp threads and weft threads respectively shall appear on the surface of the corresponding fabric at that pick. Ordinarily in figured weaving each crosswise row of the original design is transferred to aV pasteboard card in which the warp squares of the design are represented by perforations and the weft ones by unperforated spots. Such cards are prepared in accordance with the entire design and laced together into an endless chain in the order of the crosswise rows of the design, and such chain of cards is connected with the warp threads through needles and hooks of jacquard mechanism in Fig. 10 is an such manner and corresponding order of arrangement that by the Joint action of the cards, needles, vhooks and other weaving mechanism a pattern in conformity to the design is produced in the fabric manufactured. Likewise in the present instance the crosswise rows of the original design b, of which Fig. 20 is an illustration, are transferred consecutively to corresponding consecutive lengthwise divisions or sections of design roll a (Figs. l, 6, 21) on the same principle as that on which they ordinarily are transferred to cards in jacquard weaving. The warp squares of the original design are represented by perforations, and the weft ones by unperforated spots, in the design roll, and the entire design is represented by the design roll in the sense in which it is ordinarily represented by a chain of cards. Also the design roll is connected with the warp threads through air tubes and air hoists in such manner and corresponding order of arrangement that by the joint action of the design roll, air tubes, air hoists and other weaving mechanism a pattern in conformity to the original design is produced in the fabric manufactured. Said design roll a is preferably of draftsmans tracing cloth, or may be of some tough and strong quality of paper comparatively eX- empt from influence of ordinary climatic changes, or may be of very thin sheet met-al or any suitable liexible material. The circles al (Fig. 2l) represent peg holes along the border of the design roll. Like peg holes are to be along the opposite border of the same. They are usually 1/2 inch apart between centers, and are used for feeding the roll by the pegs a2 (Fig. l) in the feedrollers a3.

If a fabric is to be woven with the design sheet in Fig. 2l, and with white warp and black weft, and if the designed word is to read It in black on the face of the fabric, the fabric must be woven face down; for the Word will read Ti in white on the upper surface of the fabric. But if the fabric is woven with the design sheet turned around border for border land surface for surface, the word will read It in White on the upper surface.

lt is recommended that a design roll of full length be about 4 inches diameter' and on a one-inch spool. Such roll will be 30() feet long. Usually 1/2 inch of the length of the design roll is appropriated to representing a crosswise row of the original design, so that such a roll as mentioned is equivalent to T200 cards; and it is l/5 the minimum length and less than l/QOO the bulk of an ordinary chain of cards of that capacity. As provision is made for readily taking' out and putting in a roll, it is obvious that a single design of great elaborateness may be on several rolls which may be worked in succession conveniently. Hence there is facility for producing a Woven pattern of extra-ordinary elaborateness conveniently.

The orifices a4 (Figs. l, 22) of the tube holder a5 must correspond in number and numerical order to the spots on a division of the design roll which are appropriated to representing a crosswise row of the original design, and must be the same distance apart both ways and of the same diameter as the spots7 so that the orifices will be in alinement with the corresponding spots at each resting stage of the advance of the design roll. The front surface of the tube holder a5 should be smooth, so that the design roll will slide across it without noise, violence or appreciable wear, and be durable and reliable.

The design chamber a is to be air-tight, and care is to be taken to prevent leakage therefrom except through the perforations in the design roll into the corresponding orifices at and small tubes a". The front a7 is to be removable readily, for convenience in taking out or putting in a design roll. Thin rubber packing is usually provided between the front plate a7 and the front edges of the shell of the design chamber, and the front is usually clamped to the chamber by va suitable number of clamping buttons (not shown) in well known manner, so that it can be removed handily by slight turn of the buttons. A glass window w8 in the front a7 is to enable the Weaver to see inside. The chamber is intended to be stationed lengthwise of the loom at any height preferred, and may, if desired, be on level with the weavers head, so that he can see or do anything inside while standing on the floor. Compressed air is to be maintained within the chamber' at desired degree of pressure, and may be admitted at any place preferred. In the present instance it is admitted through the tube al". Usually pains is taken to provide pure air, and it is -conveyed to the design chamber through an air hose from a suitable reservoir outside or inside the weaving room. The pressure is maintained in the reservoir by a compressor at higher degree than is needed in the design chamber, and the pressure in the chamber is regulated by an ordinary reducing valve at any convenient place between the reservoir andthe chamber. A single reservoir of suflicient capacity mayv supply air for any desired number of looms. Supply of air to the chamber may be shut off or let on readily by a cock or valve in the air hose (not shown) at a place near the chamber, in the way common in using compressed air under analogous circumstances.

The View shown in Fig. 4 is behind the framework a in Fig.` 1, and is as if seen by a person looking from the hither side of Fig. l, imagining the intervening things which obstruct the view to be out of sight.

The cam c is fixed to the shaft of Wheel c1 (Fig. 2) by which alone the invention is connected with the driving machinery of the accompanying loom. The purpose of such connection is to work-cam c in unison with the shuttle of the loom so as to advance design sheet a, intermittently, one division at each step, which is usually 1/2 inch. Each step of such advance is to be immediately at the end of each throw of the shuttle, and the movement of the cam c must be timed accordingly. lheel c1 may be driven from the shaft which usually works the griff frame of a jacquard up and down, or it may be driven from any other shaft of the loom which will insure the unison of movement desired. The cam roller c2, which travels in the heart-shaped cam slot 03, revolves on a pin fixed to the slide c* which carries the pawls c5 and c of the ratchets c7 and 08. These ratchets are fixed to the shaft cg of gear 01 (Figs.3,4),which drives gears c fixed to the shafts of feed rollers a3. As cam c revolves from the position shown, with cam roller c2 nearest the center of the cam, pawl c5 is carried in almost an instant to the right far enough to move ratchet c7 the distance of two teeth, causing gears 010 and 011 to rotate two teeth and advance feed rollers a3 one peg so as to slide design sheet a upward across the surface of tube holder ai the distance of one division. The cam roller is in the relatively long circular part of the cam slot during most of the revolution of the cam, so that the pawl is stationary during that time. In

' a relatively minute part of such revolution the pawl is made to jump back to its original place and then push the ratchet forward two teeth more, and so on. The lever-act ing parts 013 and c which hold the pins on which 05 and 06 swing, are linked together by link 012 and move unitedly. Lever cl3 bears on its upper end a pin which can be inserted at will in either of two holes in the holder 016 which is rigidly fixed to the slide c4. The in is now in the right-hand hole. By moving the end of lever 013 to the left and inserting the pin in hole 015 pawl c5 is made inoperative, and pawl 06 is made operative to work on ratchet 08, in which instance the movements of gears G10 and 011 and of feed rollers a3 and design sheet a are the reverse of what they were before. Thus it is seen that pawl c5 operates when pawl 06 does not, and vice versa; and when one goes into operative position the other goes out thereof. The provision here noted is made because occasionally it is necessary to unweave an imperfect place in the fabric which is in process of weaving, and because also often it is desirable to work the design sheet forward and upward from beginning to end and then backward and downward from end to beginning, so as to produce a symmetrical figure composed of two parts which are the reverse of each other with a common center.

The design sheet a must be rolled up by one spool as fast as it is unrolled from the other. This may be 'done with two trains of clock work, one acting on one spool and the other on the other; both normally tending to roll up the sheet, and one train unwinding while the other train is winding up. Another device working on that principle is shown in the drawings, being two spiral springs d and (Z1, as seen in Fig. 9. Each tends to roll up the sheet. Unrolling the sheet has the effect of winding up the spring which acts on the spool from which the sheet is unrolled, and the other spring unwinds while it is rolling up the sheet. After advancing forward and upward until the lower spring has been wound up and the upper one has unwound, the sheet may be advanced backward and downward until the upper spring has been wound up and the lower one has unwound. The device is useful in weaving short patterns. Either spring may be wound up or unwound by turning the nearest worm cl2.

The shafts Z3 of spools d are square in cross section, except their round bearings at the left-hand ends, which are at the right of Fig. 2, as this view is from the rear of design chamber a. (Fig. 1). The right-hand ends pass through the fianges d, and are held by the jaws d (Fig. 5) in the square channels of the blocks d", which join thc ianges to the ratchets da. These ratchets are fixed to the short shafts cl, as also are the sleeves d10 which hold the inner ends of the springs d and d1 whose outer ends are held on the rims cl fixed to the worm gears F2 which are not xedly attached to said sleeves otherwise than by the inner ends of said springs. The short shafts d have their journals in the right-hand side plate Z13 of the design chamber. It is apparent at sight how the jaws (Z6 open, shut and act. Each ratchet ZS is provided with a pawl d which is put into engagement with the ratchet to prevent said springs from unwinding when the design sheet is removed from the design chamber.

No special means of rolling up the design sheet as it unrolls is claimed as part of the invention, and any means suitable to accomplish the desired result may be used.

The small cylinders /L (Fig. 7 of the air hoists are sustained and mainly contained in a single oblong air-tight cylinder chamber h1, whose front is at the left of Fig. 7 which is an elevation of the right-hand side. This chamber is intended to be stationed above the loom with its right-hand side over the right-hand side of the loom, in the place ordinarily occupied by a jacquard. Compressed air is to be maintained in this chaluber at desir'ed degree of pressure, and may be supplied from the same reservoir as said design chamber. The air may be admitted at any place preferred, but the place provided here is through the pipe 7a2. The pressure is regulated, and the supply let on or shut olf, in the same way as in the design chamber. If preferred, the two chambers may be connected with each other by a tube between them, and in that case a single air hose from the reservoir to either of the chambers may supply the two. A separate air hoist is provided for each warp thread, unless the woven pattern is to be repeated crosswise of the fabric, in which latter case each piston rod can operate as many warp threads as a hook can in jacquard weaving. Each cylinder 7L has two openings 7a3 and 7b4 from within the chamber, one above and one below the piston of the air hoist, .and has two exhaust openings 715 and 7L outside the chamber, one below and one above the piston. Each cylinder 71J is accompanied by a compound valve, which is compounded of four valves 717, LS, 71,9, and 7110, which are so connected with each other that all of them move up or down together. Two of them, 7U and LS, work inside, and two, 71, and 711, outside the chamber. One of them, 71.*', opens and closes the lower enw trance opening, another', 71S, opens and closes the upper entrance, another, 71", the lower exhaust opening, and another, 7N", the upper one. The lower exhaust and entrance valves 7L7 and 7L are immediately connected with each other by a rod 7L11 which passes through the bottom plate of the cylinder chamber, and the lower end of this rod works as a piston in a small piston chamber 7L12 to which one of the small tubes 19 extends from the design chamber. The upper entrance and exhaust valves are immediately connected with each other by a rod 7113 which passes through the top plate of the cylinder chamber, and this rod may be an extension of rod 7L11 or not, as preferred, so long as the two are connected with each other and move together. In the present instance the partv of the cylinder inside the chamber is surrounded nearly the whole length by a sleeve, and a short piece of each end of the sleeve is one of the four valves mentioned. The sleeve and the two rods 7111 and 71.13 connect the four valves together. Rod 7L13 is of less diameter than rod 7L, so that when pressure ceases from within the corresponding small tube 19, the pressure within the large chamber will force the four valves down to their lowermost positions. Thus, if rod 7111 is 1/8 inch and rod 7113 is 3/32 inch diameter, with the same pressure per square inch on both, the upward pressure on the lower end of rod 7111 will be to the downward pressure thereon (which is equal to the excess thereof above the upward pressure on the lower end of rod 71,13) as 16 to 7. The excess represented by 9 will force the four valves up; and when pressure within the small piston chamber 71.12 is suspended, the net downward pressure represented by 7 added to the weight of the valves and rods will force the valves down. lhen the valves are forced up the effect is to close the lower exhaust 715, open the upper exhaust 71,6, open the lower entrance 714, and close the upper entrance 71,3. Thereupon compressed air rushes into entrance 7# under the piston 7L, and the corresponding piston rod, warp thread and lingo are forced to rise. But when the valves are forced to drop the effect is to close the upper exhaust, open the lower one, open the upper' entrance and close the lower one. Thereupon compressed air rushes into the upper entrance above the piston, and the piston rod is forced to descend by the combined action of the weight of the piston rod and corresponding lingo, the tension of the corresponding warp thread and the pressure of compressedlair above the piston. The long piston rod bears an upper stop 7117 and a lower' one 7L, to limit the utmost upward and the regular downward stroke of the piston.

Fig. 8 shows how the air hoists are arranged in the cylinder chamber, whose front is at the left. The upper row is treated as being numbered consecutively 1 to 16 from left to right, the next lower row 17 to 32 from left to right, and so on. There would be 26 such rows in a machine for 416 warp threads. The small tubes a coming from the design chamber are connected with the air hoists in the order of their numbers. Thus, tube 1 connects with air hoist 1, tube 2 with air hoist 2, and so on. The warp threads also are treated as being numbered consecutively from left to right facing the front of the loom.

From what has been said hereinbefore it is seen that there are six systems of units, namely, the system of squares on a crosswise row of the original design, the system of spots on each division of the design sheet, the system of orifices in the tube holder, the system of small tubes extending from the orifices, the system of air hoists, and the system of warp threads. Each system is seen to be only a multiplication of units, and the systems are treated as being numbered correspondingly, each to the others, so that any unit in one system has a corresponding unit of the same number in each of the other systems.

The long piston rod of each air hoist extends through both ends of the cylinder. The upper end 71,15 of the rod is of larger diameter than the lower end h1, so that the downward pressure of air on the piston 7114 is less than the upward, as it should be. The upper ends are larger also because these are used in adjusting the openness of the shed of the warp threads by limiting the height to which the rods can rise, and their larger diameter renders them sufficiently strongv and stiff to endure this use without 'L bending or springing. The mechanism for the adjusting is shown in Fig. 7. The horizontal board or plate m which the rods encounter is moved up ordown by turning the wheel m1, whose shaft drives the bevel gears shown, by which `the right-hand screw m2 and the lefthand screw m3, with which the board is connected by nuts, are turned oppositely to each other. The under side of the board is to be covered with sheet rubber, or the V` like. l/Vhen the piston rods rise their upper ends encounter the stopping board which limits their rise. The board shown is level. An inclinedv one with level stopping strips from side to side on its under surface, and k with the rear nut higher than the front one, can be used insteadv of the level board, so that its rear will be higher than its front, and in this way all the warp threads in the upper part of the shed can be kept on about the same incline, so that the heddles near the reed will not need to be raised so high as those more remote. Obviously a stopping board can be used which will limit the height of raising the heddles relatively to each other to suit any requirement in respect thereto.

' Referring again to the shedselecting mechanism, it' is seen that in reality the design sheet is a valve which opens and shuts A the entrances to the small tubes which control the compound valves of the air hoists. At the end of each pick the perforations, by letting on or keeping' on the upward pressure-in the air hoists, cause the correspondv4Q ing warp threads to be hoisted or else to be kept hoisted for the next pick. The purpose ofthe almost instantaneous transition from each step of advance to the next' is to make sure that duringthe transition there will be 4.5 practicallyfno interruption of pressure in a small tube whose orifice is open at the beginning of the transition, and that if a perforation shall be over that orifice at the end of the transition, the corresponding com- 5.0 pound valve will stay up and cause the corresponding air-hoist piston rod to continue holding up its warp thread. But if at the end of thetransition an unperforated spot shall succeed to a perforation and close that orifice, the corresponding compound valve will drop and the corresponding piston rod and warp thread will descend. Also if at the end ofthe transition arperforation shall succeed to an unperforated spot, the corresponding compound valve will'rise instantly and cause the corresponding piston rod and warp thread to rise.. Ity frequently happens in figured weaving thaty a certain warp thread will be needed up atv several consecutive 6 5 picks, and this will occur to many other Warp threads. This is illustrated in Fig. Q1 in case of so few as 32 warp threads. Of the 32 there are 2() up at the ist pick. At the 2nd pick 17 of the same threads are needed up. At the 3rd pick 14 are needed 70 up that were up at the 2nd. At the 4th pick 7 are needed up that were up at the 3rd. And taking the case of a single thread, the 13th is up at 7 consecutive picks, then down at the Sth, and then up again at 7 in succes- 75 sion. The like is very common in figured weaving. In the present invention the design sheet automatically causes all threads in the upper part of the shed at one pick that. are needed up at the next pick to rea() main up. It causes to be lowered only the threads not needed up at the next pick, and simultaneously with the lowering of those it. causes to be hoisted such additional. threads, if any, as are needed up at the next pick to g5 accompany those remaining up. Thus a rapid transformation of the shed from pick to pick is going on, and some of the lower and some of the upper threads are constantly shifting or interchanging their positions from down to up and from up to down, and finding their appropriate places in conformity to the selection of the design sheet, while the remaining ones stay down or up, as the case may be, until their turns come to shift or interchange their positions appropriately. Consequently there is the least possible loss of time in getting ready for each pick, and there is the minimum of wear on the warp threads and heddle cords due to chaing. No exhausts are in the small tubes a?, for the valve rod It working in any small piston chamber k12 is not so tlght as to make a special exhaust necessary, and it is found that as soon as an unperforated spot of design sheet a succeeds to a perforation over the correspondinfr orifice in the tube holder a5 the corresponding compound valve of an air hoist drops, without need of a special exhaust.

Fig. 12 shows a modification of the air hoist, which can be used if the chamber k1 is converted into a vacuuln chamber, causing the atmosphere to act like compressed air. The exits will thenbe inside the vacuum chamber, and the entrances outside. lhen the valve rod 7L is forced upward the eHect is to open the outside lower entrance 0,

close the exit 01, open the exit o2, and close the entrance o3, with the result that atmospheric pressure will force the piston It up. In this case the valve rod L13 will be larger than It, so that on suspense of pressure in chamber 71,12 atmospheric pressure on the upper rod lf3 will force the compound valve 125 down, and the result will be that piston h1* will be forced down by atmospheric pressure above it, and the piston itself will close the exit 01.

Fig. 11 shows another modification which 1.30

can be used with a vacuum chamber. Compressed air from the design chamber through the small tube a9 will force 71, up and rush into entrance a and force the piston up, thus combining compressed air below the piston with a vacuum above it. In other respects the construction and action are'the same as with the modification in Fig'. l2.

rIhe applicant desires to include in the claims the utilization of a vacuum in operating the warp threads.

Some of the measurements recommended are 1/16 inch inside diameter for the small tubes, 5/16 inch outside and l/L inch inside diameter for the cylinders placed 5/8 inch apart between centers from front to rear and 1/2 inch from side to side, l1 inches front to rear, 15 inches side to side and 6 and `3/8 inches high for outside dimensions of cylinder chamber suitable for .1c/16 air hoists, l/S inch diameter for the lower valve rod and 5/64 inch for the upper one, 1/8 inch diameter for upper part of piston rod and 5/64 inch for lower part, and t and l/2 inches for full stroke of piston.

The following claims are made:

l. In apparatus for weaving, the combination with heddles and harness to hold the warp threads of the fabric to be woven, and a plurality of hoists to work the harness and make the selected shed formation of the Warp threads, and means to operate the hoists, of a perforated design sheet reprel senting the design of the fabric, a valve seat across whose surface said sheet may slide and orifices in said seat, means to sustain said parts, means to slide said sheet across said surface so as to bring perforations in desired successive portions of said sheet into alinement with corresponding orifices at desired intervals, tubes to make connection between said orices and the means to operate said hoists, and mea-ns to exert pneumatic pressure through the perforations and corresponding orifices and tubes, all coperating to select and make the shed formation, substantially as set forth.

2. In apparatus for weaving, the combination of heddles and harness to hold the warp threads of the fabric to be woven, a plurality of air hoists to work the harness and make the selected shed formation of the warp threads, and means to operate the air hoists, including means to select the shed formation, substantially as set forth.

WILLIAM HENRY DRURY.

Witnesses:

WALTER E. LOMBARD, EDNA C. CLEVELAND.