US2875476A - Drafting frame - Google Patents

Description

March 3, 1959 H, L, P, UDE 2,875,476 DRAFTING FRAME Filed Oct. 8, 1954 2 Sheets-Sheet 1 i amwill Inventor Hans LR llde H. L. P. UDE f 2,875,476

DRAFT'ING FRAME Mare-113, 1959 2 Sheds-Sheet .2

Filed Oct. 8, 1954 Hans LP. a'de United States Patent DRAFTING FRAME Hans L. P. Ude, Bremen-St. Magnus, Germany, assignor to Spinnbau G. in. b. H., Bremen-Farge, Germany Application October 8, 1954, Serial No. 461,162 Claims priority, application Germany October 13, 1953 Claims. (Cl. 19-135) The present invention relates to fiber drafting and, more particularly, concerns an improved drafting frame, especially for drafting twisted roving.

' It is known that, when drafting twisted roving, greater retaining forces are required at the draft rollers, i. e. at the feed roller and at the delivery roller. This is due to the fact that the fiber material combined or strengthened by the twist offers a greater resistance to the drafting operation than does roving which is merely rubbed in conformity with the French system. The great clamping forces required at the feeding and the delivery rollers are in most instances furnished by spring forces.

The heretofore known drafting frames with spring loaded pressure rollers have the drawback that each of the loading springs has to be adjusted individually at the operators discretion so that the yarn lot spun on a machine is frequently being processed with different retaining forces per spindle. uniformity of the yarn spun per lot. ,In order to overcome this drawback, it has been suggested to make the spring loaded pressure rollers adjustable over the entire length of the machine. To this end, there is provided a rotatable shaft which extends over the entire length of the machine and is preferably located below the front pressure rollers, while eccentrics are mounted on said shaft for adjusting the loading springs. This known arrangement, however, caused said shaft to bend.

It is, therefore, an object of the present invention to provide a drawing frame which will overcome the abovementioned drawbacks.

It is another object of this invention to provide a drawing frame, especially for drafting twisted roving, in which the lower rollers of the pressure rollers will be prevented from bending due to high loads acting thereon.

, It is still another object of this invention to provide a drafting frame which will provide a more uniform retaining force of the drafting elements throughout the entire spinning machine. These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

V Fig. 1 is a diagrammatic illustration of a drafting frame according to the invention and illustrates a side view thereof partly in section.

Fig. la shows on a scale larger than that of Fig. l a

ice

Fig. 5 shows another embodiment of a loading spring for use in connection with the present invention.

Fig. 6 illustrates a side view of a roving guide.

Fig. 6a represents a detail for use in connection with the present invention.

General arrangement In order to prevent the lower rollers of the pressure rollers from bending due to great loads acting thereon, according to the present invention, rotatable supporting rollers are mounted on a continuous shaft which support said lower rollers. The continuous shaft may also be employed for fixing the position of the pressure rollers. To this end, it holds the fork-shaped holder for the shaft of the front pressure roller in axis parallel position with regard to the pressure rollers, said holder being pivotally connected to a fixed shaft.

The continuous shaft is preferably also provided with a torque compensator which may consist, for instance, of at least one lever mounted on said shaft, preferably in the neighborhood of the roller stands and cooperates with a spring for compensating the torque.

Preferably, the loading springs are so designed that they can be individually withdrawn from the pressure rollers. The loading springs may be designed in the form of a I U-shaped arm. If desired, the loading springs may also be mounted on rigid yokes and may have their thrust This fact considerably impairs the variable by means of screws. springs may be force-locked feeding roller pair.

Uniform retaining force may instead of the spring loaded feeding rollers also be obtained by a porcupine roller which is provided with short pins in which the twisted roving is embedded while partly embracing the roller. For tensioning the roving prior to its entrance into the porcupine roller, the porcupine roller may be preceded by a roving guide, which guide is preferably tiltably arranged and may have a plurality of passages for the yarn.

Preferably the rear loading with the lower roller of the Structural arrangement Referring now to the drawingsin detail, the drafting frame for twisted roving as illustrated in Figs. 1 and 2 substantially comprises a pair of feeding rollers 1 and 2 and a pair of delivery rollers 3 and 4 between which the yarn is drafted. The pressure of all loading springs of one or both sides of the spinning machine is infinitely variable from a starting pressure slightly above zero (almost complete relief of the pressure rollers) up to full load, said variation or control being effected centrally, i. e., from a single control station as will be set forth further below. This control will now be described with regard to the front pressure or delivery rollers 3, 4 with view of Fig. 1 seen in the direction of the arrow Z of V the upper roller pairs Headed by the U-shaped springs 5. Below the lower roller 3 (fluted roller), there is provided a shaft 6 which extends all the way through along the entire length of the machine and is pivotally journaled in the machine frame.

Within the spaces between each two adjacent pressure rollers 4, shaft 6 has fastened thereto rings 7 with pins 8 which are respectively engaged by one leg of the springs 5, whereas the other leg 5' of the respective springs 5 presses against the shaft 9 of the pressure roller pairs 4 which are rotatably journaled in fork-shaped portions 10a of holders 10. As will be seen from Fig. 1, spring 5 has a slight depression 5a which is engaged by pin 8 when the latter occupies its dead center position shown in Fig. 1.

When shaft 6 is turned about its axis, for instance, by means of a manually operable crank (not illustrated) connected to one of the ends of shaft 6, the loading springs 5 are due to the members 7, 8 either tensioned or relieved. In this way, from a single control station represented by such crank, each spring pertaining to the respective pressure roller pair 4 is tensioned or relieved uniformly so that each pressure roller will be subjectedto the same pressure. It is, of course, selfunderstood that shaft 6 must not be turned beyond a certain angle in order to prevent the springs from falling off.

In order to prevent the lower rollers 3 from bending due to the load exerted thereupon by the fact that the pressure rollers 4 are pressed thereagainst at high pressure, and in order to relieve the roller bearings 11 in the roller stands 12, rotatable supporting rollers 13 are mounted on shaft 6. These supporting rollers 13 roll on necks 14 provided between each two fluted sections of the roller 3. In this way, a short circuited power flow is obtained between thepressure roller 4 and feed roller 3, which is now subjected to bending over a fraction only of its length, namely, thelength l of the distance 31 between the roller stands (Fig. '2). It will be evident from the above that the roller bearings are not subjected any longer to the sum of the pressure roller'loads between the two roller stands but only to one pressure roller load. The roller 3, as well as the bearings of the roller stands '11 and, of course, also the shaft 6 subjected to the spring forces, are therefore considerably relieved.

1n the case of the greatest spring load as illustrated in Fig. 1, the shaft 6 is not subjected to torsion by the springs 5. However, as soon as the pin 8 is turned out of the dead center position shown in the drawing, a torque acts upon the shaft 6, which torque may assume a considerable magnitude due to the fact that all spring forces or torques on the entire machine side will add up. This means that when turning the shaft 6 for re lieving or loading the pressure rollers, very considerable torques or forces have to be applied, and that furthermo're the shaft 6, due to the influence of .said torques, would progressively become, distorted over the length of the machine by a considerable angle, so that also thepins 8 would assume-different positions from drafting field to drafting field, and, consequently, also the springs would be non-uniformly tensioned or loaded. For this reason, with this type of spring load, a torque compensating arrangement is required on shaft 6, which torque compensating arrangement is diagrammatically shown in Fig. 3.

With reference to Fig. 3, there are provided links 15a which have one end pivotally connected at 15b to stationary points of the framework, while the other end of each link 15a has a shoe 15c slidably mounted thereon. The shoes are pivotally connected at 15d to levers 15 which are keyed or otherwise fixedly connected to the shaft 6 in spaced relationship to each other, preferably in the neighborhood of the roller stands 12. Each link 15a is surrounded by'a spring 16 the upper end of which rests against an adjustable nut 152, while the lower end of spring 16 rests against the slidable shoe 15c. These pressure springs 16 are tensioned or loaded when the shaft 6 is rotated in the direction of the arrow C, in other words, when the loading springs 5 are relieved. Thus, the torque exerted by the springs 5 and acting in the direction of the arrow C is counteracted by the torque exerted by the springs 16 upon the lever 15 and acting in the direction of the arrow D. By properly dimensioning the springs 16 and the levers 15, it is possible without difiiculty to safeguard the shaft 6 against torsion. Independently of the central relieving and loading possibility, each individual loading spring 5 may easily be withdrawn and returned to its position. Each pressure roller can, therefore, independently be relieved and loaded. When pulling on the spring 5 in the direction of the arrow E (Fig. 1), the leg or finger 5 of the spring 5 snaps off from the shaft 9 of the pressure roller 4 and, since the end 5" of the finger 5' is slanted,the

spring can easily be returned to the position shown in Fig. l by exerting pressure in the direction of the arrow F, so that the pressure roller is again loaded. This arrangement also affords the possibility easily to exchange the loading springs over an entire machine side for loading springs of different thrusts.

The shaft 6 carrying the supporting rollers 13 may also serve for fixing the positions of the pressure rollers 4. To this end, as shown in Fig. l, the holder 19., which grasps the pressure roller shaft 9 in a fork-like manner and holds the roller 4 in axis parallel position withregard to the lower rollers 3, is held in its rest position by means of the bore 10' through which the shaft 6 passes. The other end of the lever 10 is pivotally connected to the stationarily arranged shaft 28.

As shown in Fig. l, the loading springs may be designed as U-shaped springs and may respectively consist of a, single piece. When the cover of the pressure rollers 4 has to be ground due to wear .so that its outer diameter will be reduced, this difference may be compensated for in order not to weaken the effective force of the spring. This canbe effected either by placing a bushing upon the pressure roller shaft 9 or by designing said shaft as an eccentric shaft. If desired, however, the loading spring itself may be designed so that it can be varied as illustrated for instance in Fig. 4.

According to the arrangement of Fig. 4, a pressure spring 26 is inserted into a yoke 17. The tensioniug force or thrust of the spring can then be adjusted, for instance, in conformity with the diameter of the pressure roller 4, for example, by rotating the screw 18.

Also the feed roller pair 1, 2 may principally be provided with a pressure exerting device of the type described above which can be adjusted and can be removed. However, also a simpler loading mechanism may be employed as illustrated for instance in.Fig. 1. This simplified loading mechanism consists of anaxially displaceable yoke'l'ia designed as tubular hollow body and provided with a nose 39 having a saddle 31 therein. It is by means of this saddle that yoke 17a presses upon the shaft 32 of the feed roller 1. This pressure is produced by a pressure spring 26a pressing against the inner bottom surface of yoke 17a and resting in the opposite end against a pipe 33 serving as handle. The thrust of spring 26a may be varied by screwing pipe 33 to a greater or less extent upon a threaded portion 36 of a bolt 37 which extends into the yoke 17a andis pivotally supported by a pivot 38 in frame 39. The removal of yoke 17a may be effected by tilting the yoke 17a about pivot 38 in the direction of the arrow A, while the loading may be effected by turning the yoke 17 in the direction of the arrow B. The loading device may also directly'be force-locked with the lower roller designated 19 in Fig. 5. Instead of employing the feed roller pair 1, 2 as retaining means, also a porcupine roller 20 may be provided which has short pins into which the twisted roving will embed itself when the roving is passed around the porcupine roller along a sufficient are. It is, however, necessary that the roving enters the porcupine roller with substantially uniform fiber tension so that it will not too loosely lie upon the porcupine roller. Such an arrangement is shown in Fig. 6. The pins of the porcupine roller 20 pierce the twisted roving 22 which, due to its twist, is safely temporarily retained in the porcupine roller. The retainf ing force is all the greater, the greater the twist is which has been imparted upon the roving.

In order to facilitate the entry of the yarn into and resting of the yarn on the porcupine roller 20, the arrangement shown in Fig. 6 may be employed. According to this arrangement, a shiftable yarn holder 23 is connected with the traversing roving rail 24. This holder. is shifted into the position indicated by dash lines when theroving is inserted. Thereupon the holder 23 is pressed downwardly into its operable position sothat mavens-e thereby the rovin bzzi entering the" porcupine roller is given the necessary embracing angle on the porcupine roller 20.

As will also be evident from Fig. 6a, the roving 22, 'prior to its entering into the porcupine roller 20, is passed around a plurality of embracing arcs 25 provided on the yarn holder 23 so that due to the friction in the holder, a certain retaining force is exerted upon the roving 22 and the lattercan then under slight tension be pulled into the porcupine roller 20. Instead of the serpentine shaped deflecting device (Fig. 6a) for the roving which must be so designed that the roving will not be subjected to too much friction or tension, there may also be provided at this point rollers which will guide the roving.

It is, of course, understood that the present invention is, by no means, limited to the particular construction shown in the drawings, but also comprises any modifications within the scope of the appended claims What I claim is:

l. A drafting frame for a preparing or spinning machine, especially for drafting twisted roving,which corn prises in combination: a plurality of drafting fields, a plurality of pairs of upper rollers respectively associated with said drafting fields, a plurality of lower rollers respectively arranged for cooperation with said upper rollers, a rotatable adjusting shaft extending all the way through over substantially the entire length of said machine, a plurality of loading springs respectively associated with said upper rollers and operable to exert pressure thereon, a plurality of eccentric means rotatably connected to and arranged on said shaft while being spaced from each other in axial direction of said shaft, said eccentric means being arranged in response to a turning movement of said shaft simultaneously to vary the thrust of all of said springs, and a plurality of roller means engaging said lower rollers and respectively arranged on said shaft between each two adjacent lower rollers to support said lower rollers.

2. A drafting frame according to claim 1, in which each of the loading springs consists of a substantially U-shaped single integral member having one leg in engagement with one of said eccentric means and having its other leg in operative engagement with one of said pairs of upper rollers for exerting pressure thereon.

3. In a drafting frame comprisinga plurality of drafting fields for use in connection with a preparing or spinning machine, especially for drafting twisted roving, in which each drafting field has associated therewith two normally spring loaded front pressure rollers and two lower rollers cooperating with and arranged below said front rollers, said lower rollers being interconnected by shaft portions, the combination of: a rotatable adjusting shaft extending all the way through over substantially the entire length of the machine, a plurality of loading springs respectively associated with said pressure rollers and operable to exert pressure thereon, a plurality of eccentric means respectively arranged in spaced relationship to each other and mounted on and connected to said shaft for varying the thrust of said springs, a plurality of roller means respectively mounted on said shaft and arranged to roll on and supportingly to engage said shaft portions, a fixed shaft, and a plurality of holder means respectively pivotally supported by said fixed shaft and respectively supporting said pressure rollers, said rotatable shaft holding said holder means in axis parallel relationship to said pressure rollers.

4. A drafting frame according to claim 3, in which the pressure rollers have laterally protruding therefrom a stud, and in which the holder means has fork-shaped portions for engagement with the studs of the respective pressure roller.

7 5. A drafting frame for a preparing or spinning machine, especially for drafting twisted roving, which com- 6, prises in combination: a plurality of drafting fields, a plurality of pairs of upper rollers respectively associated with said drafting fields, a plurality of lower rollers respectively arranged for cooperation with said upper rollers, a rotatableadjusting shaft extending all the way through over substantially the entire length of said machine, a plurality of loading springs respectively associated with said upper rollers and operable to exert pressure thereon, .a plurality of eccentric means arranged in spaced relationship on and connected to said shaft for varying the thrust of said springs, a plurality of roller bearing means respectively arranged between each two adjacent lower rollers and supported by said shaft to journal said lower rollers, and torque compensating means arranged for acting upon said rotatable shaft to counteract any torque exerted upon said rotatable shaft by said spring means.

6. A drafting frame according to claim 5, in which said torque compensating means includes at least one lever means rigidly connected to said rotatable shaft and also includes spring means arranged for cooperation with said lever means.

7. A drafting frame for a preparing or spinning machine, especially for drafting twisted roving, which comprises in combination: a plurality of drafting fields, a plurality of pairs of upper rollers respectively associated with said drafting fields, a plurality of lower rollers respectively arranged for cooperation with said upper rollers, a rotatable adjusting shaft extending all the way through over substantially the entire length of said machine, a plurality of roller stands arranged in spaced relationship to each other for supporting said shaft, a plurality of loading springs respectively associated with said upper rollers and operable to exert pressure thereon, a plurality of eccentric means arranged in spaced relationship on and connected to said shaft for varying the thrust of said springs, a plurality of roller members respectively arranged between each two adjacent upper rollers and supported by said shaft to form bearings for said lower rollers, and torque compensating means including at least one lever means rigidly connected to said rotatable shaft and arranged near the adjacent roller stand and also including spring means arranged for cooperation with said lever means.

8. A drafting frame for a preparing or spinning machine, especially for drafting twisted roving; which comprises in combination: a plurality of drafting fields, a plurality of pairs, of upper rollers respectively associated with said drafting fields, a plurality of lower rollers respectively arranged for cooperation with said upper rollers, a rotatable adjusting shaft extending all the way through over substantially the entire length of said machine, a plurality of loading springs respectively associated with said upper rollers and operable to engage said upper rollers for exerting pressure thereon, each of said loading springs being adapted individually to be withdrawn from engagement with the respective upper roller, a plurality of eccentric means arranged in spaced relationship on and connected to said shaft for varying the thrust of said springs, and a plurality of roller means respectively arranged between each two adjacent lower rollers and supported by said shaft to form bearings for said lower rollers.

9. A drafting frame for a preparing or spinning machine, especially for drafting twisted roving, which comprises in combination: a plurality of drafting fields, a plurality of pressure rollers respectively associated with said drafting fields, a plurality of lower rollers respectively arranged for cooperation with said pressure rollers, a rotatable adjusting shaft extending all the way through over substantially the entire length of said machine, a plurality of loading springs respectively associated with said pressure rollers and operable to exert pressure thereon, at least some of said springs comprisinga "substantially rigidyoke and an adjustable spring carried thereby, a plurality of eceentricmeans arranged ings for said lower rollers.

10. A drafting frame according to claim 9, in which I the adjustable spring is adjustable by means of a screw.

References Cited inthe file of this patent UNITED STATES PATENTS Naumberg Mar. .4, 1924 Jones et a1. Mar. 7, 1944 Marzoli June 6, 1944 Tweedale Mar. 17, 1953 FOREIGN PATENTS Great Britain of 1902 Great Britain July 16, 1948

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