US3500876A - Universal weft stop motion - Google Patents

Description

March 17, 1970 'R. BALAGUER GOLOBART UNIVERSAL WEFT STOP MOTION Filed May 21. 19 68 2 Sheets-Sheet 1 March 17, 1970 R BALAGUER GOLOBART 3,500,876

UNIVERSAL WEFT STOP MOTION Filed May 21, 1968 2 Sheets-Sheet 2 United States Patent 3,500,876 UNIVERSAL WEFT STOP MOTION Ramon Balaguer Golobart, 86 Calle Caspe, Barcelona, Spain Filed May 21, 1968, Ser. No. 730,860 Claims priority, applicatirgglspain, May 26, 1967,

Int. Cl. D03d 51/34 U-S. Cl. 139-370 5 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a weft stop motion for fixed-weft looms, of the type that is mounted on the side on which the weft thread enters the loom, so as to detect the breakage or the absence of the thread to be inserted into the shed.

There are different types of lateral weft stop motions for detecting the breakage of the weft thread in fixed-weft looms, principally those constituted by blades or fingers which sense the existence of the weft thread, but these types of weft stop motions have the disadvantage of not permitting the simultaneous insertion into the shed of a plurality of weft threads in the same pick, because the sensing blade or fingers rests against all the threads, re quiring also that these threads be under tension, because when they are loose the weft stop motion also stops the loom.

There are other weft stop motions constituted by a series of thread guides through which the weft threads pass; in these mechanisms it is the weft threads themselves, under tension, which actuate the weft stop motion.

These known weft stop motions have to be adapted to the types of fabrics being made, i.e., to the nature and thickness of the weft threads, necessitating the application of tension devices between the stationary bobbins so that the latter may perform their function of detecting the breakage or absence of weft thread, because it is the weft thread itself which, in passing under tension through the thread guides, operates the weft stop motion, this tension being harmful in many cases, depending on the type of fabric being made, as for example fabrics made of loose, heavy fibers that are liable to pull apart, such as baizes and blanketing, and fabrics made of weak fibers such as viscose, rayon or gauze.

In many cases, as for example in the manufacture of fabrics from very tough fibers, it is necessary to use, in addition to the tension device that is required between the stationary bobbin and the stop motion so as to en able the weft thread to operate the stop motion, another tension device situated between the stop motion and the beginning of the shed on the respective side of the loom.

In the case of the selection and feeding of a plurality of weft threads to the inserting means, these weft stop motions require an individual tension device for each weft thread, each situated between each bobbin and each stop motion, and this requires a large amount of space and a large number of tension devices.

For the operation of the loom, the above-mentioned weft stop motions require that the weft thread be under tension, so as to bring it about that, in passing through the thread guides, the weft thread may cause an electri- "ice cal connection or disconnection in the weft stop motion (depending on the type of stop motion) by the rocking or displacement of the said thread guides, in synchronism with remote contacts in the device that presents the weft threads to the inserting means, the operation of the loom being stopped precisely upon the loss of tension in the Weft thread as a result of breakage, looseness or exhaustion of the supply of the weft thread which results in the failure of the thread guides to rock or deflect, producing the electrical connection or disconnection in the weft stop motion, depending on the type of stop motion, and the loom being stopped even when the weft thread is loose, which in the case of certain types of fabrics, is a serious disadvantage.

All these disadvantages are eliminated by the weft stop motion of the present invention, wherein the loom operates without any tension on the weft thread, that is, without the need for the installation of additional tension devices between the stationary bobbins and the weft stop motion, because the stop motion operates while the weft thread is moving, completely independently of the tension; the loom is stopped when the weft thread is not moving, either due to the breakage or exhaustion of the thread or to the failure of an inserting mechanism.

If the type of fabric being made requires that the weft threads inserted into the shed be under a certain tension, the proper tension device will be placed between the stop motion and the beginning of the shed on the respective side of the loom. In other words the said tension device will be installed solely to meet the requirements of the fabric being made, but not for the operation of the weft stop motion, which does not itself require that the weft thread be under tension. In cases in which the fabric to be made requires the insertion of the weft thread without any tension, the use of any type of tension devices will be dispensed with, and this cannot be done with the weft stop motions of the prior art mentioned above.

The weft stop motion of the present invention is universal and can be used not only on looms in which only one weft thread has to be inserted into the shed on each pick, but also on those which require the insertion of a plurality of weft threads at once on each pick, the stop motion stopping the loom even when only one of the weft threads breaks, and even when the threads are of different natures and gauge sizes.

The weft stop motion of the present invention comprises a body which supports a number of stiff wires each bearing thread guides on their upper extremities and being adapted to pivot on themselves upon the passage without tension of a Weft thread through each thread guide, and the other lower free extremity of the stiff wires being bent so that, in its pivoting, as long as weft thread is present, it prevents the extremities of springs mounted on said body from making contact with projections of contacts connected to electrical terminals mounted on the insulating base of said body.

For "better comprehension of the invention, a description will now be given of an embodiment, with reference to the attached drawings which are given by way of nonlimitative example.

FIG. 1 is a front view in perspective of a preferred form of weft stop motion, showing its component elements;

FIG. 2 is a perspective rear view of the device of FIG. 1;

FIGS. 3, 4, and 5 are sections in perspective, on a larger scale, of one end of the weft stop motion in three positions of its operation; and

FIG. 6 is a schematic perspective of the application of the weft stop motion to a loom.

The Weft stop motion of the present invention is constituted by a body 1, FIGS. 1 and 2, having side plates 2 and 3, mounted on a support 4 affixed to the loom beds 5 and 6, FIG. 6.

On the rear portion of body 1, FIG. 2, there are provided cross members 7 and '8 pierced vertically by apertures 9 and 10 to hold stiff wires 11, which bear on their upper extremities 12 thread guides 13, and whose lower extremities 14 are bent into a hook 15, FIGS. 3, 4, and 5, passing through the apertures 16 in a wall 17 afiixed to the frame of body 1, FIG. 2.

Passing through body 1, and resting its extremities 18 and 19 on the lateral members 20 and 21 of body 1, there is pivotingly disposed a shaft bar 22 bent, at its extremity 23 and outside of body 1, to a double right angle 24 and 25, FIGS. 2, 3, 4, and 5, with a prolongation 26 parallel to and above the front portion of this bar 22, and bent in turn at its other extremity 27, FIGS. 1, 3, 4 and 5, to a double right angle 28 and 29, to whose lower extremity 30 there is attached a connecting rod 31 which is given a vertical reciprocating movement by any driving element of the loom.

To the said lower shaft bar 22 there are affixed by means of screws 32 and 33 the arms 34 and 35, FIG. 1, of a rocking bar 36 which has notches 37 along its entire lower length to accommodate the lower extremities 38 of springs 39 whose coiled bodies are supported and traversed by a fixed rod 40 borne at its extremities 41 and 42 in the side members 20 and 21 of body 1, and whose upper extremities 43 abut against the plate 17 of body 1.

On the electrically insulating base 44 of body 1 there are mounted a set of contact plates 45 with contact projections 46, FIGS. 3, 4, and 5, there being as many of them as there are thread guides 13, and they are affixed to insulating base 44 by nuts 47 and connected to the conductors 48 by the nuts 49.

Operation is as follows:

When the loom is operating normally without any weft thread breakage, the shaft bar 22, in synchronism with the insertion of each weft thread 50, is oscillated in a forward and backward rotary direction by means of some element of the loom (not shown), the forward position, FIG. 3, coinciding with the retention of the thread guides 13, which, when released by the descent of bar 26, FIG. 4, perform a slight oscillation about the axis of its supporting wire 11 produced by the mere passage of the weft thread without tension, and this, by producing the pivoting of thread guide 13, FIG. 5, and the stiff wire 11, also produces the pivoting of the lower, hooked extremity 15 of the wire 11, the latter interposing itself between the projections 46 of contact plates 45 and the long, lower extremities 38 of springs 39, which bear against the notches 37 in the rocking bar 36, which in turn has performed a descending movement because it is affixed to shaft bar 22. These failures of contact in the stop motion coincide with the making of contact in the thread guides of the remotely situated thread presenter 51, FIG. 6.

When breakage occurs in a weft thread 50' coming from a bobbin 53' and passing through a thread guide 52 and through the corresponding thread guide 13' of the weft stop motion, FIG. 5, the passage of same through the thread guide 13 will simultaneously cease and consequently, when the corresponding stiff wire 11' is released from being held by bar 26, it will not turn, and its bottom end 141, hooked at 15 will not block the passage of the corresponding long bottom extremity 38' of spring 39', which will ground itself on the shaft bar 22 and make contact with the respective projection 46 of contact 45' which, when it coincides with the remote contact of the corresponding thread guide of presenter 51, FIG. 6, Will pass the current causing the loom to stop.

I claim:

1. Universal weft stop motion mechanism for fixedweft looms, comprising a frame for mounting the mechanism on a loom, a plurality of electrical switch means on said frame each including a fixed contact and a movable contact biased toward the closed position, a series of vertical wires mounted on the frame for oscillatory movement about their axes, each of said wires including thread guide means and stop means, each of said thread guide means being responsive to the presence of a weft thread to urge a wire in one direction to position the stop means to prevent closure of a switch means, shaft bar means including rocking bar means mounted on the frame for oscillatory translatory movement and drive means for connecting said shaft bar means with a movable element of a loom in timed relation to a weft inserter means for moving the shaft bar means in one direction to engage said wires to move said stop means out of position to prevent closure of the movable contacts and also to move the rocking bar means to move the movable contacts into open position during one portion of a cycle of operation and in another portion of said cycle to move said shift bar means in the other direction out of engagement with said wires whereby said rocking bar will release said movable contacts for closure with a fixed contact whenever a stop means remains out of position as a result of the absence of a weft thread.

2. Apparatus defined in claim 1, wherein thread guides are secured at the upper ends of said wires, and said stop means comprises a hook-shaped extremity formed at the lower end of each of said wires.

3. Apparatus defined in claim 1, wherein said movable contacts comprise a series of depending elements yieldable mounted on said frame, said shaft bar means comprises an element formed to provide a pair of horizontally elongated parallel arms, one of said arms comprising said rocking arm means, said latter arm means being provided with notches for engagement with said depending switch means elements.

4. Apparatus defined in claim 3, wherein said movable contacts comprise a series of coil springs mounted on a horizontal bar supported by said frame, said depending elements comprising one extremity of each coil spring.

5. Apparatus defined in claim 1, wherein said fixed contacts comprise conductive plates having projections mounted on a non-conductive base forming a portion of said frame.

References Cited UNITED STATES PATENTS 2,744,174 5/ 1956 Martin et al. 3,237,651 3/1966 Ancet et al. 139122 3,272,236 9/1966 Ancet et a] l39-370 X 3,282,303 11/1966 Ancet et a1. 13937O 3,299,909 1/ 1967 .Golobart 139122 FOREIGN PATENTS 736,521 9/1932 France. 1,102,704 5/ 1955 France. 1,369,438 7/1964 France.

JAMES KEE CHI, Primary Examiner

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