US3826289A

US3826289A - Method for inserting weft in shuttleless looms

Info

Publication number: US3826289A
Application number: US00283757A
Authority: US
Inventors: P Galkin; N Rudenko
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-12-15
Filing date: 1972-08-25
Publication date: 1974-07-30
Anticipated expiration: 1991-07-30
Also published as: FR2163429B1; DE2245407A1; DD100028A1; DE2245407B2; CH556412A; GB1400193A; FR2163429A1; CA973778A; SU456863A1

Abstract

A method for laying weft thread in the warp shed used in needle looms is disclosed. This method consists in that the feeding and the receiving laying needles mutually reciprocate to transfer the weft thread at the moment of their closest approach. The needles meet at the midpoint of the distance between the starting points of their reciprocating movement for which purpose the needles are made different in length. The shorter needle is introduced into the warp shed with a time lag relative to the moment of inserting the longer needle thereinto, thus making the needles move in one direction while the weft thread is transferred, whereupon the needles return to their initial positions leaving the warp shed at the same time. At the expense of extending the time of contact of the needles during their movement in one direction, this method permits of significantly improving the conditions for catching the weft and sharply reducing the number of mispicks, loops, and double threads.

Description

Galkin et al.

" 1111 3,826,289 [4 July 30, 1974 METHOD FOR INSERTING WEFT IN Primary Examiner-Henry S. Jaudon SHUTTLELESS LOOMS Attorney, Agent, or Firm-Holman & Stern [76] Inventors: Pavel Vladimirovich Galkin, ul. 1

proezd, la; Nikolai Antonovich ABSTRACT Rudenko, ul. Lesnaya, 4, kv. l0, A method for [a f ymg we t thread in the warp shed used both of Khmovsk in needle looms is disclosed. This method consists in [22] Fil d; A 25, 1972 thaltl the feeding and thereiceivilng layfinghneegles m:- tua y reciprocate to trans er t e wet t rea at t e [2]] Appl' 283757 moment of their closest approach. The needles meet at the midpoint of the distance between the starting [30] Foreign Application P i it D t points of their reciprocating movement for which pur- 15 1971 USS 1724106 pose the needles are made different in length. The shorter needle is introduced into the warp shed with a [52 us. (:1 139/127 R time lag relative) the moment insertingethe longer 51 1 1m. 01 l)03d 47/18 needle therein), making the needles move in one [58] Field of Search 139/122 123 124 R direction while the weft thread is transferred, where- 139/127 i P upon the needles return to their initial positions leaving the warp shed'at the same'time. At the expense of [56] References Cited extending the time of contact of the needles during their movement in one direction, this method permits UNITED STATES PATENTS of significantly improving the conditions for catching 322%? 1323 2 y l the weft and sharply reducing the number of mispicks,

l'C S 3762.449 10/1973 Eilhaucr et ul. 139 127 loops and double threads 3 Claims, 3 Drawing Figures 1 5 H I 5 I Illllllllllllllllllllllllllllllllllllllllillllll lllllllllllllllllllllll llll]llllllIllllllllIllllllllllllllllllllllllllll lllllllllllllllllllllll METHOD FOR INSERTING WEFT IN SHUTTLELESS LOOMS BACKGROUND OF THE INVENTION The present invention relates to methods for laying weft threads in the warp shed of a loom which may find wide application in weaving on needle looms.

A method for laying weft thread is known to be used at present in needle looms, wherein the feeding and the receiving laying needles mutually reciprocate by means of interconnected drives to pass the weft thread at the moment of their closest approach.

In order to realize this method, the needles are placed on either side of the weaving width of the loom and simultaneously enter the warp shed so as to transfer the weft thread from one needle to the other midway between the starting points of their reciprocating motion with the aid of a forced and suction air jets, or mechanical grips.

In these conventional methods, the time of contact between the needles or the period of standstill at the moment of their closest approach required for passing the weft thread is too short which often involves failure to catch the weft thread, and hence adversely affects the quality of manufactured fabric.

In the pneumatic method for transferring the weft thread from one needle to the other, the thread from the needle with the forced air jet must emerge well before the needles meet, since the time of contact being too short and moving apart of the needles too rapidly the weft thread may be missed by the suction air jet of the other needle, thus failing to accurately pass the weft thread.

The weft thread emerging from the needle before both needles meet may catch on the warp threads or miss the other needle, thus causing faults in weaving, such as mispicks, loop-knots, and double threads.

When passing the thread by means of mechanical grips, a very brief contact of the needles also causes frequent failure to catch the weft thread.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the aforesaid disadvantages.

Another object of the present invention is to provide a method for laying thread into the warp shed allowing an extension of the time of contact of the needles when passing the weft thread from one needle to the other without reducing their speed or affecting the working capacity of the loom.

With these and other objects in view, in the method for laying weft thread in the warp shed of a loom, wherein the feeding and the receiving laying needles reciprocate with respect to each other by means of interconnected drives to pass the weft thread at the moment of their closest approach, according to the invention, the needles meet at the midpoint of the distance between the starting points of their reciprocating motion for which purpose the needles are made different in length, and the shorter needle is introduced into the warp shed with a time lag relative to the moment of introducing into the shed the longer needle which, at the moment of its maximum advance into the warp shed, approaches the shorter needle, moving toward it, as close as possible, and as the longer needle starts returning to its initial position, the shorter needle, continuing its stroke into the warp shed, follows the longer needle, the time of movement of the needles in one direction being proportional to the value of the time lag, and, after the shorter needle advances into the warp shed to a maximum, the needles return to their initial positions leaving the warp shed at the same time.

Such an embodiment of the needles and their simultaneous movement in one direction within a certain length make it possible to extend the time of contact of the needles, thus providing more favorable conditions for passing the thread from one needle to the other, which enabled to significantly reducethe amount of fabric discarded on account of mispicks, loops, and double threads.

The invention is further characterized by that the total length of both needles exceeds the distance between the starting points of their reciprocating movement, thus making the needles meet at the midpoint of the weaving width of the loom and move in the same direction while the weft thread is-passed from one needie to the other.

Moreover, the invention is also characterized by the fact that the longer needle is introduced into the warp shed faster than the shorter needle, thus allowing for a simultaneous withdrawal of the needles from the warp shed without increasing the operating cycle time to lay one weft thread, and hence, without affecting the speed of the needles and the working capacity of the loom.

An extension of the time of contact of the needles during their closest approach for transferring the weft thread from the feeding needle to the receiving needle will thus permit of: significantly improving the conditions for catching the weft; sharply reducing the number of mispicks, loops, and double threads in the fabric; improving the quality of fabric; widening the variety of manufactured fabrics; enhancing the working capacity of the needle loom by stepping up its working speeds as the conditions for laying the weft thread have been improved.

BRIEF DESCRIPTION OF THE DRAWINGS A better appreciation of the invention will be had from the following detailed description of one of its embodiments, taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a sectional view of a device in a loom for laying weft thread by the method according to the invention;

FIG. 2 is a schematic representation of the position of the needles at the moment of their closest approach; and

FIG. 3 is a schematic representation of the position of the needles at the starting moment of their separation as they move toward their initial positions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The device for laying weft thread in the warp shed of a loom consists of two laying needles I and 2 (FIGS. 1, 2) mounted on either side of the weaving width of the loom, the needle 1 receiving the thread and the needle 2 feeding it, and interconnected drives 3 and 4 which impart to the needles 1 and 2, respectively, reciprocating motions toward each other across the weaving width of the loom. The drives 3 and 4 may be of various designs so long as they can enable the needles to reciprocate, only one embodiment thereof, viz. a planetarygear drive, will be discussed below.

The needles 1 and 2 are made different in length, thus the receiving needle I has a length l and the feeding needle 2 has a length I, so that l l while the total length L of the needles (FIG. 3) exceeds the distance L, (FIG. 1) between the starting points A and B of their reciprocating moement, the difference in lengths of the needles 1 and 2 accounting for their closest approach at the midpoint of the distance L Each of the drives 3 and 4 comprises a sun gear 5, a planet pinion 6, and two idle gears 7 each engaging the gears and 6.

The'fixed sun gear 5 is disposed on'a shaft 8 secured wherein is a pinion carrier 9 articulated to axles 10 of the idle gears 7.

One of the ends of a lever 12 is articulated to an axle ll of the planet pinion 6, the free ends of the levers 12 in each drive 3 and 4 being hinged to the ends of the needles 1 and 2, respectively.

The diameters of the sun gear 5, the planet pinion 6, and the idle'gears of the drive 4 are somewhat bigger than those of the respective gears of the drive 3, and both the lever 12 and the pinion carrier 9 of the drive 4 are slightly longer than those of the drive 3, all this accounting for a somewhat higher linear speed of the needle 2 relative to that of the needle 1 and, consequently, ensuring a simultaneous withdrawal of the needles 1 and2 from the warp shed.

The kinematic coupling of the drives 3 and 4 is accomplished through a main shaft 13 of the loom (FIG. 1) on whose ends there aresecured bevel gears 14 which mesh with bevel gears 15 mounted on the shafts 8 of the sun gears 5 of the drives 3 and 4.

Fixed on the main shaft 13 is a cam 16 which, through a shackle 17 with rollers and a rocker shaft 18, sets a reed 19 into swinging motion which reed beats up the weft thread to the fell.

In order to provide for a normal thread passage from one needle to the other with a specified length of the needles, the drive 3 of the shorter needle 1 should introduce it into the shed with a time lag relative to the moment the longer needle 2 is inserted into the shed by the drive 4.

This can be realized in various ways, for instance, by actuatingthe drive 3 somewhat later than the drive 4, or actuating the drives at the same time with the drive 3 running idly during the time lag, i.e. most different alternatives are here possible determined primarily by the drive design or by the loom servicing conditions.

Regardless of the means for achieving this time lag, the

drive 4 of the longer needle 2 must ensure its insertion into the warp shed to a maximum, while the drive 3 must ensure the closest approach of the shorter'needle 1 to the longer needle and a continuation of its advance into the warp shed, and as the longer needle 2 starts returning to its initial position, the shorter needle 1 should follow it, i.e. within a length a (FIG. 2) the needles 1 and 2 must move in the same direction, the time of movement of the needles in one direction being proportional to the time lag no matter which of the needles, the feeding or the receiving one, is shorter.

In the present example, the time lag is provided by displacing the pinion carrier 9 with the idle gears 7 and the planet pinion 6 of the needle drive 3 through an angle [3 relative to the position of the carrier 9 with the idle gears 7 and the planet pinion 6 of the drive 4,

4 which angle determines the time of movement of the needles in one direction, i.e. the length a of their movement in the same direction.

The above-described device lays'the weft thread as follows.

Rotation from the main shaft 13 (FIG. 1) is, through bevel gears 14 and 15, transmitted to the shafts 8 of the drives 3 and 4 of the needles 1 and 2.

The sun gears 5 (FIG. 2), the idle gears 7 and the planet pinions 6 convert by means of the pinion carriers 9 the rotary motion of the shaft 8 into reciprocating motion of the levers 12 which move the needles 1 and 2 in guides (not shown).

Since the carrier 9, the idle gears 7, and the planet gear 6 in the drive 3 are displaced through an angle [3 relative to the position of the carrier 9, the idle gears 7, and the planet pinion 6 in the drive 4, the needle 2 enters the warp shed somewhat earlier and faster than the needle 1. As the needle 2 has a length l, exceeding the length l of the needle 1, the closest approach of these needles is at the midpoint of the distance L between the starting points A and B of their reciprocating movement, and at the moment of the maximum advancement of the longer needle 2 into the warp shed the shorter needle 1 continues its movement into the warp shed and approaches the longer needle 2.

At this instance,the needle 2, the carrier 9, and the lever 12 of the drive 4 are arranged in one line, whereas the carrier 9 of the drive 3 is still at an angle [3 to the path of the needle 1, therefore as the longer needle 2 starts returning to its initial position, the shorter needle 1 follows it. In other words, within the length a, the needles 1 and 2 move in the same direction (the direction of movement of the needles is indicated by arrows in FIGS. 2 and 3), the time of their movement in one direction being proportional to the value of the angle 5. When the shorter needle 1 advances to a maximum into the warp shed, the needle 1, the carrier 9, and lever 12 of the drive 3 are arranged in one line, whereas the carrier 9 of the drive 4 is at an angle a" to the path of th needle 2. a

At the moment of the closest approach of the needles 1 and 2 and all along the length a of their movment in one direction, the weft thread is transferred from one needle to the other, i.e. thetime of contact of these needles increases on account of their moving in the same direction, which in turn improves the conditions for catching the weft thread. Once such movement of the needles is achieved, it makes no difference whether the thread is transferred by mechanical grips or by an air jet. If the weft thread is to be transferred by an air jet, the receiving needle 1 should advisably be shorter than the feeding needle 2.

As the linear speed of the needle 2 is somewhat higher than that of the needle 1, they return to their initial positions leaving the warp shed at the same time.

After the needles 1 and 2 (FIG. 1) return to their initial positions, the laid weft thread is beaten up by the reed 19 to the fell, and the next portion 20 of the weft thread (FIG. 2) is fed into the needle 2 from a bobbin 21 through a measuring mechanism 22 of a conventional design provided with a compensator 23.

What is claimed is: r

1. A method for laying weft thread in the warp shed of a loom, said method comprising the steps of:

reciprocating a feeding needle and a receiving laying needle in the warp shed with respect to each other to transfer the weft thread at the moment of their closest approach; effecting the needles to meet at the midpoint of the distance between the initial positions of their reciprocating movement, the needles being made different in length for this purpose; introducing the shorter one of the needles into the warp shed with a time lag relative to the moment of insertion into the shed of the longer one of the needles which, at the time of its maximum advancement into the warp shed, approaches the shorter one of the needles and moves toward it as close as possible; returning the longer one of the needles to its initial position, while the shorter one of the needles continues its movement into the warp shed and follows the longer one of the needles, the time of movement of the needles in one direction being proportional to the value of the time lag; returning the needles to their initial positions after the shorter one of the needles has advanced to a maximum into the warp shed; during the return of the needles to the initial positions, withdrawing them from the warp shed at the same time; and realizing the reciprocation of the needles by means of interconnected drives.

2. A method as claimed in claim 1, providing the total length of both needles to exceed the distance between the initial positions of their reciprocating movement.

3. A method as claimed in claim 1, providing the longer one of the needles to enter into the warp shed at a faster speed than the shorter one of the needles.

Claims

1. A method for laying weft thread in the warp shed of a loom, said method comprising the steps of: reciprocating a feeding needle and a receiving laying needle in the warp shed with respect to each other to transfer the weft thread at the moment of their closest approach; effecting the needles to meet at the midpoint of the distance between the initial positions of their reciprocating movement, the needles being made different in length for this purpose; introducing the shorter one of the needles into the warp shed with a time lag relative to the moment of insertion into the shed of the longer one of the needles which, at the time of its maximum advancement into the warp shed, approaches the shorter one of the needles and moves toward it as close as possible; returning the longer one of the needles to its initial position, while the shorter one of the needles continues its movement into the warp shed and follows the longer one of the needles, the time of movement of the needles in one direction being proportional to the value of the time lag; returning the needles to their initial positions after the shorter one of the needles has advanced to a maximum into the warp shed; during the return of the needles to the initial positions, withdrawing them from the warp shed at the same time; and realizing the reciprocation of the needles by means of interconnected drives.