US2618445A - Yarn brake - Google Patents

Description

Nov. 18, 1952 K. BUDER 2,618,445

YARN BRAKE Filed NOV. 7, 1950 2 SHEETS-SHEET l l@ @Wm i@ K. BUDER YARN BRAKE Nov. 18, 1952 2 SHEETS-SHEET 2 Filed Nov. 7, 1950 Patented Nov. 18, 1952 YARN BRAKE Karl Bilder, Augsburg, Germany, assigner to `osef Sailer Maschinenfabrik, Augsburg, Germany Application November 7, 1950, Serial No. 194,467 In Germany November 9, 1949 This invention relates to a yarn brake or yarn tension appliance, more particularly for cop creels, of the type in which the yarn is more or less deflected from its straight course by a mechanically or magnetically actuated guide pivotally mounted with respect to a stationary guide.

In a known yarn tension appliance of this type, a spring is arranged in such a way that it has its minimum tension in case of maximumv de Ilection of the yarn from its straight line course, i. e. in a position Where it is intended to exert the maximum braking effect upon the yarn, and on the other hand it has its maximum tension when the yarn runs on a straight course and it is intended to produce a minimum braking effect or no braking effect at all. Therefore, in order to avoid this highly undesirable eifect a construction has been proposed in which the carrier of the movable guide engages the passing yarn under action of its own weight; to this end it has been pivoted at a point disposed eccentrically to its center of gravity of an axis which is parallel to the direction of course of the yarn. However, since the weight depending on the kind of material used and the specific gravity thereof is liable to variations and more particularly, in case of the poreclain material used for this pur pose is diflicult to be determined, a spring has been adopted as an additional loading means with the result that the above mentioned disadvantage is again present and the intended effect is made illusory.

It is an object of the present invention to avoid the foregoing difficulty and to providea yarn brake whose braking effect is properly adapted to the initial tension of the yarn.

Another object of the invention is to provide means for permitting a reliable and easy automatic control of the delecting force exerted upon the movable guide.

Still another object of the invention is to provide means for permitting a common central control of the deflecting force of a plurality of yarn brakes or of all yarn brakes of a creel.

With these and further objects in view according to the present invention, the spring loading the carrier of the movable guide is arranged in such a way in relation to the pivot of the carrier that its torque of the carrier remains unchanged or advantageously even grows with increasing deection of the yarn despite the reduction of the spring tension, by a proportional or even larger increase of its effective lever arm. In this manner conditions are provided which can 4 Claims. (Cl. 242-454) be accuratelypredetermined and ensure a satisfactory braking in accordance with the requirements.

My novel yarn brake moreover renders it unnecessary to arrange the pivot eccentrically with respect to the center of gravity or" the carrier for the movable guide. Instead, according to a further feature of the invention the carrier of the movable guide is preferably fulcrumed lin such a Way as to be in the state of equilibrium as to the gravity forces. To this end, it is preferably pivoted on an axis disposed perpendicularly to the direction of the course of the yarn. In this manner ail reactions upon the yarn braking lclue to the weight of the carrier that are incapable of being accurately controlled are eliminated, the braking effect rather being determined exclusively by the spring force. The pivotal mounting of the carrier of the movable guide on an axis disposed perpendicularly to the direction of course of the yarn has the special advantage that in case of the provision of a plurality of deecting points, different positions are obtained with respect to the pivot axis, so that the deflections at the points which are more remote from said axis are larger than those at the points which are disposed closer thereto. Accordingly while in the known arrangement of the pivotal axis parallel to the direction of the course of the yarn all movable guide members cause a uniform deflection, this is not the case in the appliance according to the present inven-` tion. This non-uniform deflection results in a more gradual and softer change of the braking effect. Since in practice it is hardly possible to do With a single deflecting point, but nearly always a plurality thereof are required, it will be understood that for instance in case of six deflections in the known construction all of the six deflections act simultaneously and uniformly. This, primarily during transition from the nonbrake position causes a very sudden growing of the braking eifect, while in my appliance at first only the two extreme deecting points become effective, then the two intermediate deect ing points and only in the nal phase all the six deflecting points produce a braking effect, the two extreme ones in the meantime causing a larger deflection and braking effect than the intermediate ones and the latter again causing a larger deflection than the two innermost deflecting points.

I prefer to mount the carrier of the movable guide in such a way that it is in the state of equilibrium as to gravity forces in two planes disposed perpendicularly to each other so that a state of balance will exist even in case of a vertical direction of course of the yarn. To this end the axis of the pivot is arranged to intersect with the center of gravity of the carrier of the movable guide. The two guides which are most adjacent to the pivotal axis are interconnected by a sleeve for the passage of the yarn on which sleeve the pivot is secured. This sleeve also offers the advantage of facilitating the threading of the yarn in the setting operation.

According to an important alternative embodiment of the invention the spring may be replaced by an electro-magnet producing the defiecting force, which magnet can be controlled by adjustment of the exciting current of the electro-magnet. This offers the advantage that the force can be changed by simple means which is not possible to a larger extent in case of springs while such adjustment will |be desirable where a wide variety of yarns are to be worked. The electromagnetically operated yarn brake, moreover, is an improvement in as much as the force can be changed infinitely and thus can be adapted to the yarn to be actually worked with an extreme degree of sensitivity so that even in case of working the same type of yarn the most appropriate tension can be accurately adjusted. Moreover, this oifers the advantage that it is possible to connect the electromagnets of all yarn brakes of a cop creel to a common means for regulation of the electric current.

Yarn brakes or tension appliances of this general type so far have been made of metal or porcelain. The latter has the advantage of a wear-resistant surface which is particularly suitable for guiding the yarn. However, porcelain is very fragile and the yarn brake made therefrom is endangered with each introduction and removal of the cops. The parts of the yarn tension appliance consisting entirely of porcelain, moreover, cannot be manufactured very accurately. This applies especially for the mounting of the pivot which can be made only in a very crude form, whereby the whole yarn tension appliance obtains a crude character.

According t the present invention these disadvantages are also eliminated by making the carriers of tlie stationary and of the movable yarn guide of a plastic material in which the eyes forming the thread guide and consisting more particularly of porcelain are interchangeably inserted, more particularly, cemented. Therefore, in my novel thread brake the real thread guiding surface is likewise formed of porcelain, but the porcelain eyes are easily interchangeable so that when they are worn out this does not mean that the whole yarn brake has to be junked. The other parts of the yarn brake, however, consist of a synthetic plastic which is practically unbreakable, very light and first of all adapted to be molded into a very accurate shape, for instance, by injection molding, The parts made of this material can be manufactured very cheaply in mass production. The porcelain eyelets can be very easily connected thereto by welding or cementing and can be easily removed therefrom.

Other and further objects, features and advantages of the invention will be pointed out hereinafter and appear in the appended claims forming part of the application.

In the accompanying drawings a now preferred embodiment of the invention is shown by way of illustration and not by way of limitation.

Fig. 1 is a sectional view, on the line lil-l of Fig. 2,

Fig. 2 is a section on line 2 2 of Fig. 1.

Fig. 3 is a sectional view on line 3-3 of Fig. 4, and

Fig. 4 is a, sectional view on line 4-4 of Fig. 3.

Referring now to the drawings in greater detail it will be seen that the casing l made of an injection molded synthetic material and adapted to be mounted on the creel frame comprises two eyelets 3 of porcelain disposed in such a way that their common axis intersects with the axis of the fulcrum 2 of metal, said eyelets being arranged on the right and on the left 0f said fulcrum, as well as an inlet eye 4 and an outlet eye 5, likewise consisting of porcelain, for the yarn 6. Mounted on the pivot 2 is a carrier 8 of plastic material comprising pairs of eyes of porcelain 9, Ill, and il symmetrically spaced on the right and left of the pivot 2. This carrier 8 is in a state of balance in relation to its pivot 2 since the axis of the pivot intersects with the center of gravity of the carrier Therefore, the pivot 2 is fastened on, or formed integral with, the sleeve I8.

The carrier 8 is tensioned by a spring 20 engaging the carrier 8 at i9 and fastened to the casing I at 2|. By way of alternative, by an electromagnet i2 comprising terminals I3 and an armature lil operatively connected to the carrier il by means of a link member 22 linked to the carrier 8 at '1. This tension tends to move the carrier il into the position shown in Fig. l so that the yarn 6 in the condition as shown is deected from its straight course, the deflection beingl larger at 9 than at il) and being larger at I0 than at Il. When the tension of the yarn 6 rises, it will tend to pull the carrier 8 into its straight line course; in this case the braking effect may be decreased and in fact the braking effect is reduced by a reduced extent of the deflections or of the arc of contact between the yarn and its guide points and thereby of the friction. The torque exerted on the carrier by the spring 20 also decreases despite its increased tension because its lever arm in relation to the pivot 2 in this .case is considerably decreased. This also applies with regard to the link 22 of the electromagnet in its dotted line position 22.

The arm I3 of synthetic material can be riveted to the casing l at 23 on the right or left hand side thereof. The terminals 3 of the electromagnet l2 are connected to an adjustable resistance (not shown) i. e. all magnets of the creel may be connected to a common adjustable resistance whereby the force of attraction of the magnetic armatures can be infinitely varied by a central control. The articial material s electrically insulating for the electric wires so that no special insulation is required. I

.While the invention has been described in detail with respect to a now preferred example and embodiment of the invention it will be understood by those skilled in the art after understanding the invention that various changes and modificat1ons may be made without departing from the spirit and scope of the invention and it is intended, therefore, to cover all such changes and modications in the appended claims.

What is claimed is:

l. In a yarn brake and tensioning device especially for cop creels, a casing, stationary yarn guides carried by the casing, a carrier pivotally mounted intermediate its ends in the casing yarn guides on the carrier extending into the zone of the stationary guides and capable of alnement for unrestricted passage of yarn therethrough in a Straight line of movement, means for biasing the carrier and guides thereon and for moving the guides on the carrier out of alinement with the stationary guides for delecting the yarn from a straight line of travel through the guides and for braking and tensioning the yarn, the yarn guides on the carrier being located at opposite sides of the carrier pivot and at equal radial distances from said pivot whereby the carrier is supported in a state of equilibrium, the carrier biasing means being engaged with the carrier at one side of and adjacent the pivotal mounting of the carrier whereby the tension on the yarn caused by the change of position of the carrier and guides carried thereby is varied in such manner that the torque exerted by the biasing means on the carrier remains substantially constant as the tension on the yarn decreases while the deflection of the yarn increases.

2. In a yarn brake and tensioning device, especially for cop creels, a casing, stationary yarn guides carried by the casing, a carrier pivotally mounted intermediate its ends in the casing, yarn guides on the carrier extending into the zone of the stationary guides and capable of alinement with the stationary guides for unrestricted passage of yarn therethrough in a straight line of movement, a spring connected to the carrier for biasing the carrier and guides thereon and for moving the guides on the carrier out of alinement with the stationary guides for deiiecting the yarn from a straight line of travel through the guides for braking and tensioning the yarn, the yarn guides on the carrier being located at opposite sides of the carrier pivot and at equal radial distances from said pivot whereby the carrier is supported in a state of equilibrium, the spring being attached at one end to the casing and at its other end to the carrier adjacent the side of the carrier pivot nearer the opposite end of the casing whereby tension on the yarn caused by the changed position of the carrier and guides carried thereby is varied in such manner that the torque exerted by the spring on the carrier remains substantially constant as the tension on the yarn decreases While the deflection of the yarn increases.

3. In a yarn brake and tensioning device, especially in cop creels, a casing, stationary yarn guides carried by the casing, a carrier pivotally mounted intermediate its ends in the casing, yarn guides on the carrier extending into the zone of the stationary guides and capable of alinernent with the stationary guides for unrestricted passage of yarn therethrough in a straight line of movement, an electromagnet having a link connection with the carrier for biasing the carrier and guides thereon and for moving the guides on the carrier out of alineinent with the stationary guides for deecting the yarn from a straight line of travel through the guides for braking and tensioning the yarn, the yarn guides on the carrier being located at opposite sides of the carrier pivot and at equal radial distances from said pivot whereby the carrier is supported in a state of equilibrium, the electromagnet being carried by the casing and a link being connected to the carrier adjacent one side of the carrier pivot whereby the tension on the yarn caused by the changed position of the carrier and guide carried thereby is varied in such manner that the tonque exerted by the electromagnet on the carrier remains substantially constant as the tension on the yarn decreases while the deflection of the yarn increases.

4. A yarn brake as in claim 1, wherein a sleeve is supported on the carrier at one side thereof between and in line with the yarn guides on the carrier, and the two yarn guides adjacent opposite sides of the carrier pivot being supported in the ends of the sleeve.

KARL BUDER.

REFERENCES CITED The following references are of record in the le of this patent:

FOREIGN PATENTS Number Country Date 22,908 Switzerland Nov. 16, 1900 528,386 Great Britain Oct. 29, 1940

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