US2905207A - Shuttleless loom with continuous weft supply - Google Patents

Description

7 Sept. 22, '1959 G. PIAZZOLLA 2,905,207

SHUTTLELESS LOOM WITH CONTINUOUS WEFT SUPPLY Filed MM 20. 1956 s Sheets-Sheet 1 f'IQZ Sept 22, 1959 G. PIAZZOLLA SHUTTLELESS LOOM WITH CONTINUOUS WEFT SUPPLY Filed March 209 1956 3 Sheets-Sheet 2 INVENTOR.

Sept. 22, 1959 G. PIAZZOLLA SHUTTLELESS LOOM WITH CONTINUOUS WEFT SUPPLY 3 Sheets-sheaf, 3

Filed March 20. 1956 IN VE N TOR.

Unite State Giovanni Piazzolla, Milan, Italy, assignor to Etablissement Matex, Milan, Italy, a Liechtenstein firm Application March 20, 1956, Serial No. 572,764

2 Claims. (Cl. 139-424) This invention has reference to shuttleless looms with continuous weft supplies, which are especially suitable for weaving narrow fabrics such as ribbons, braids, trimmings and the like. More particularly, the invention is concerned with shuttleless looms of the kind wherein, during each weaving cycle, a weft thread is looped around a binding warp thread'running along one edge of the woven fabric from a spool rotatably mounted in a'carriage which is reciprocable through and at right angles to the weaving plane, the said weft thread being passed through a shed of warp threads and beyond the binding thread by a loop-forming arm, and returned through the shed by the said arm after the carriage and bobbin have been traversed through the weaving plane. The bobbin for the binding thread is of limited size and thread capacity so that it has to be removed and replaced by a fully wound bobbin at relatively short intervals; one of the principal objects of the present invention is to enable such removal and replacement of the binding-thread bobbin to be effected quickly and easily thereby interrupting the operation of the loom fora minimum period and increasing the output of Woven fabric from the loom.

Further objects of the invention are to minimize the possibility of the holder for the said binding-thread bobbin twisting or becoming otherwise misaligned during its reciprocal movements through the weaving plane, to ensure rotation of the bobbin within the carriage only by an increase in tension of the binding thread, to maintain a constant braking action on the bobbin as the bulk of thread wound thereon is reduced, and to simplify the mechanism for actuating the loop-forming arm. In accordance with the said invention, a loom of the kind referred to, comprises a stationary bracket which is provided with guide rods for the reciprocable bobbin carriage, which rods are located normal to the weaving plane, the said carriage being provided with a bobbinholder having a bobbin-receiving spindle which is located at right angles to the said rods.

Preferably, the bracket is provided with at least two continuous guide-rods on and along which the bobbin carriage is adapted to slide from one side to the other of the weaving plane, and at least two pairs of coaxial posts which are parallel to the guide-rods and are adapted to be slidably engaged by the bobbin holder, the adjacent ends of the posts in each pair being spaced apart to permit passage of the weft thread.

The .bobbin may be rotatably retained upon a spindle provided on the holder, by a blade which bears upon the wound thread, is pivoted about a pin parallel to the spindle and is loaded by a torsion spring disposed around and anchored to the pin so that as the diameter of the wound bobbin decreases due to the removal of thread therefrorrnthe torsion of the spring is decreased and a substantially uniform braking action is exerted by the blade on the bobbin and the thread is maintained at a substantially constant .tension.

i The loop-forming arm may be linked to the beater Patented. Sept. 22, 1959 of the loom so that, as the said beater is actuated to beat up the weft into the woven fabric, the arm is actuated through the linkage to carry the weft through the warp shed and, after the weft has been looped around the binding thread, to return it through the said shed. For this purpose a curved slot is preferably, formed in and transversely of the arm; a stud provided on a lever engages the slot and the lever is coupled to the beater through a drive-transmitting link. However, as it is desirable that the arm should remain stationary whilst the beater completes its operative stroke and commences its return stroke, the slot may comprise an arcuate portion which, as the arm returns to its initial position after returning the weft through the warp shed, is disposed concentrically to the lever pivot and is'entered by the stud thereby enabling the stud to be driven in both direc tions along the arcuate portion of the slot without imparting movement to the arm.

In order that the invention may be more readily understood and carried into practice, reference will now be made to the accompanying drawings, wherein:

Figure 1 is a plan of that part of a shuttleless loom to which the invention applies, showing the loop-forming arm (in'full lines) in the extreme position it assumes after passing the weft thread through the warp shed and prior to the looping of the said weft thread around the binding thread in one side of the woven fabric.

Figures 2 and 3 are elevations, on an enlarged scale, showing the bobbin carriage in two different operative positions.

Figure 4 is a plan, similar to Figure 1, showing the loop-forming arm in its alternative extreme position, part of the bed plate of the loom having been broken away.

Figure 5 is a perspective view, on a still larger scale, of the binding-thread bobbin and its holder, and

Figure 6 is an elevation, similar to Figure 2, of an alternative bobbin carriage.

As shown in Figures 1-5, a shuttleless loorn for weaving a narrow fabric such as a ribbon 2, comprises a bed plate 1 which is adapted to be fixed horizontally upon the frame of the loom by bolts or equivalent fixing expedients (not shown) engaging elongated holes 3. If desired, a number of bed plates and their associated mechanisms may be fixed side by side upon the frame.

A U-shaped bracket 4 is fixed upon one lateral edge of the forward end of the plate; the aims 5 and 6 ofthe said bracket are disposed horizontally and above and below the weaving plane of the loom respectively.

Two parallel rods 7 and 8 are fixed within the bracket between and at right angles to the said arms in the vicinity of the roots of the latter; also, two parallel posts are fixed at right angles to each of the arms 5 and 6 in the vicinity of the free ends of the latter; the posts 9 and 10 fixed to the arm 5, are located in coaxial relationship to the posts .11 and 12, respectively, fixed to the arm =6; all four posts extend inwardly of the bracket and the adjacent ends of each two co-axial posts are spaced apart from one another and differently from the weaving plane.

A bobbin carriage 15 located within the bracket, is carried by the rods 7 and 8 and is displaceable lengthwise of the said rods by a connecting rod 20 of which one end is pivoted upon the carriage at 19 and the opposite end is pivoted at 19 to a lever 21 fast upon a driving shaft 22; the shaft is adapted to be rocked about its axis, in a timed sequence, by the loom mechanism so as to rock the lever 20 in the direction indicated by the arrows E and F, and reciprocate the carriage lengthwise of the rods during which reciprocation the carriage is guided by the rods along a vertical path.

The carriage is formed with spaced arrns 17 and 18 which are parallel to the bracket arms Sand 6 which are formed with holes which enable them to make sliding engagement respectively with the coaxial posts 9, 10 and 11, 12.

A bobbin holder 16 is disposed between the carriage arms and is of a depth which is less than the distance between the said arms so that by vertical displacement of the holder within the carria e, a clearance d may be created between its lower edge and the arm 18 (see Figure 2) or between its upper edge and the arm 17 (see Figure 3). The holder is formed with holes with which the aligned posts engage so that the holder is guided vertically during its movement within the carriage, and during its travel along the posts under the action of the carriage arms.

A spindle 26 (see Figure fixed upon and at right angles to a vertical face of the holder 16, projects horizontally from the bracket and to the side of the bracket remote from the plate 1 so that it is readily accessible to an operator. A bobbin 25 on which binding Warp thread 23 is wound, is rotatably mounted upon the spindle and is retained upon the said spindle by a blade 28 which is pivoted about a pin 27 provided upon the holder in parallel relationship to the bobbin spindle, and is urged into contact with the thread wound around the bobbin, by a torsion spring 29. The central portion of the spring is anchored to the pivot pin by a radially projecting pin 30 and its opposite ends seat upon the side of the blade remote from the bobbin.

As the thread is unwound from the bobbin and the effective bobbin diameter is thereby decreased, the torsion in the spring is decreased with the result that a substantially uniform braking action is imparted to the bobbin and the tension in the thread being unwound therefrom is maintained substantially constant.

The binding thread extends from the bobbin through an aperture 3-1 formed in the blade, over a roller 34 journalled between two ears 32, 33 formed from the blade material, through a loop shaped member 35 and over a grooved pulley 36 journalled in the holder on its side adjacent to the plate 1.

A spring-loaded finger 53 connected to said loop member 35 slidable along on the holder, is adapted to be held by the tensioncd thread against spring-initiated displacement, in the position wherein it projects laterally of the holder so that, in the event of the binding thread breaking or the supply of thread from the bobbin becoming exhausted, it is adapted to be spring driven to the position in Figure 5 wherein it projects to the underside of the holder and blocks the clearance d between the said holder and the lower carriage arm 18.

A loop-forming arm 14 is journalled about a vertical axis 52 below the bed plate 1 so that during each weaving cycle, it is adapted to be rocked in a horizontal plane from an extreme inoperative position (see Figure 4) wherein it projects beyond the opposite side of the bed plate to the bracket 4 and is wholly disengaged from the comb (not shown), through the warp shed, to an opposite extreme position (see Figure 1) wherein it reaches to the side of the bracket adjacent to the said plate so as to carry the weft thread 13 through the warp shed and one of the clearances d between the coaxial posts 10, 12 and 9, 1'1, and then be returned to its initial extreme position to remove the weft thread through the other of the said clearances d after vertical displacement of the carriage within the bracket so as to loop the weft thread around the binding thread.

To impart such rocking movement to the loop-forming arm, the said arm comprises a transverse sector-shaped plate 39 which is formed with a curved slot 40; a drivetransmitting stud 41 projecting from a lever 42, engages freely in the slot, the said lever being located below the arm 14 and being pivoted in the plate 1 about a fulcrum 43 which is located in eccentric relationship to the arm pivot 52. The opposite end of the lever is connected by a ball coupling 44 to one end of a link 45 of 4 which the other end is connected by a ball coupling 46 to the beater 47 of the loom.

The slot is formed with a circular portion which, when the loop-forming arm is located in its extreme inoperative or initial position shown in Figure 4, is concentric to the fulcrum 43, and coincides with the arcuate path of travel of the stud 41. Hence, the stud is able to be driven along the said groove portion without imparting movement to the arm 14 although when located within the remaining portion of the slot, it is adapted to rock the arm from one extreme position to the other due to the lever 42 being turned about its fulcrum by the link 45 as the beater is driven through its forward operative stroke and its return idle stroke.

At the commencement of each weaving cycle, the beater has been driven through the initial stage T (see Figure 4) of its return stroke and is completing the said stroke, and the drive transmitting stud 41 has reached the open end of said circular slot portion. Therefore, during the remainder of the beater return stroke the stud thrusts against the edge of the slot and swings the loopforming arm 14 from its extreme inoperative position, through the dotted line position shown in Figure l to its opposite extreme position and during this movement of the arm, the weft thread is carried through the warp shed. As the loop-forming arm approaches the said opposite extreme position, the bobbin carriage 15 and the bobbin holder 16 are so positioned that a clearance d comes in register successively with the inter-post clear ances so that the arm is adapted to carry successively the weft thread through the said clearances into the carriage to a position beyond the holder. The carriage is then driven lengthwise of the rods 7, 8 and posts 9, 10, 11 and 12 so that the other clearance d is brought into register with the inter-post clearances and the weft thread is lopped around the binding thread. Thereupon, the beater commences its working stroke and the loop-forming arm is returned to its initial extreme position so that the weft thread is carried through the said other clearance and back through the shed, at which stage in the cycle of operations, the driving stud has again reached the open end of the circular slot portion which has been returned to the position wherein it is concentric to the lever fulcrum. Consequently, the beater is able to be driven through the final stage S of its Working stroke and commence its return stroke whilst the loop-forming arm is at rest, during which time the comb (not shown) is withdrawn and the heddles (also not shown) change over the warp threads to produce a fresh warp shed.

To prevent deflection of the binding thread by the looped weft and thereby assure a straight selvedge of the fabric, a wire 37 (see Figure 1) connected upon the carriage 15 extends from the said carriage alongside the binding thread towards the woven fabric 2.

Since the bobbin spindle projects horizontally from the holder 16 to the outside of the bracket 4 and is in a readily accessible position, it may be removed and replaced by a fresh bobbin quickly and easily particularly as removal is adapted to be effected merely by swinging the blade away from the bobbin against the action of the torsion spring 29, and the fresh bobbin is adapted to be retained upon the spindle merely by releasing the said blade and allowing it to be spring driven against the sur= face of the binding thread on the fresh bobbin. As previously mentioned, such speedy removal and replacement is particularly advantageous because it reduces to a minimum the time during which the operation of the loom must be interrupted whilst the change over is effected. Furthermore, the bobbin is carried in a readily visible position so that a loom operator may see at a glance when the supply of binding thread is becoming exhausted and may arrange for the placement in good time.

The guiding of the holder 16 by the vertical co-axial posts is effected independently of the horizontal bobbin spindle so that the vertical travel of the said holder is assured with safety; moreover, the provision of two pairs of guide posts prevents any tendency for the holder to swivel about a vertical axis or otherwise be misaligned relatively to the carriage 15 and twisting of the carriage arms 17, 18 is also avoided. It will be appreciated that bobbin holder (Figs. 2 and 3) during the passage of weft thread i.e. during its critical position is supported by three or four posts, thus improving its stability.

The simple beater-initiated actuation of the loop-forming arm 14 by the stud 41, ensures the desired regular operation and control which is so necessary for the efficient operation of the loom.

In the alternative carriage construction shown in Figure 6, the U-shaped bobbin carriage 15 is carried and guided along an arcuate path located in a vertical plane, by two curved guide posts 48, 49 which are secured in a common arc to the bracket arms 5 and 6 respectively, and are spaced at their adjacent ends to provide a passage for the weft thread midway between the said arms. The carriage is adapted to be reciprocated lengthwise of the said posts by the connection rod 20 and is prevented from rotating about the longitudinal centre lines of the posts or from otherwise being misaligned, by an extension 51 from its base, which extension is pivoted about a horizontal fulcrum 50 in the heel of the bracket 4. In addition, misalignment of the carriage and the bobbin holder 16 is prevented by making the posts 48 and 49 of prismatic or other non-circular section and forming the holes in the carriage arms and the holder of a corresponding shape.

I claim:

1. In a shuttleless loom with continuous weft supply, in combination: a U-shaped stationary bracket fixed to a bed plate; a fork shaped carriage; a loop forming arm; means to reciprocate said fork-shaped carriage between the arms of said U-shaped stationary bracket; a bobbinholder arranged with a clearance between the arms of said fork-shaped carriage and presenting a horizontal spindle for a removable binding thread bobbin; guide means for said bobbin holder and said fork-shaped carriage comprising at least two guide rods fixed to the arms of said U-shaped stationary bracket and two pairs of aligned posts being parallel to said guide rods; the ends of said aligned posts projecting differently from the respective arm of said U-shaped bracket to permit successively the passage of weft thread between one of said posts and the adjacent arm of said fork-shaped carriage respectively during the upper and lower position of said fork-shaped carriage; a sector shaped plate fixed to said loop forming arm and pivoted below said bed plate; a curved slot cut in said sector shaped plate and presenting a circular slot portion; a lever pivoted below said bed plate and articulation means connecting said lever to a loom beater; a drive transmitting stud fixed to said lever and engaging said curved slot; said circular slot portion being concentric to the trip of said drive transmitting stud during the final stage of forward stroke and the initial stage of return stroke of said beater.

2. In a shuttleless loom with continuous weft supply, in combination: a U-shaped stationary bracket fixed to a bed plate; a fork-shaped carriage; a loop forming arm; means to reciprocate said fork-shaped carriage between the arms of said U-shaped stationary bracket; a bobbinholder arranged with a clearance between the arms of said fork-shaped carriage and presenting a horizontal spindle for a removable binding thread bobbin; guide means for said bobbin holder and said fork-shaped carriage comprising at least two guide rods fixed to the arms of said U-shaped stationary bracket and two pairs of aligned posts being parallel to said guide rods; the ends of said aligned posts projecting diiferently from the respective arm of said U-shaped bracket to permit successively the passage of weft thread between one of said posts and the adjacent arm of said fork-shaped carriage respectively during the upper and lower position of said fork-shaped carriage; a sector shaped plate fixed to said loop forming arm and pivoted below said bed plate; a curved slot cut in said sector shaped plate and presenting a circular slot portion; a lever pivoted below said bed plate and articulation means connecting said lever to a loom beater; a drive transmitting stud fixed to said lever and engaging said curved slot; said circular slot portion being concentric to the trip of said drive transmitting stud during the final stage of forward stroke and the initial stage of return stroke of said heater; and resilient means to exert a uniform braking action during the whole unwinding of said bobbin comprising a blade, pivoted to said bobbin holder and urged into contact towards said bobbin by a spring means.

References Cited in the file of this patent UNITED STATES PATENTS 2,652,072 Villa et a1 Sept. 15, 1953 2,757,692 Coppa Aug. 7, 1956 FOREIGN PATENTS 826,276 Germany Dec. 27, 1951

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