US2982083A

US2982083A - Test apparatus for textile drafting and spinning machines

Info

Publication number: US2982083A
Application number: US591498A
Authority: US
Inventors: Breitenbach Karl-Heinz
Original assignee: SKF Kugellagerfabriken GmbH
Current assignee: SKF GmbH
Priority date: 1955-06-15
Filing date: 1956-06-14
Publication date: 1961-05-02
Anticipated expiration: 1978-05-02
Also published as: GB808857A; DE1011331B; FR1154870A

Description

May 2, 1961 KARL-HEINZ BREITENBACH 2,982,033

\TEST APPARATUS FOR TEXTILE DRAFTING AND SPINNING MACHINES May 2, 1961 KARLHEINZ BREITENBACH TEST APPARATUS FOR TEXTILE DRAFTING AND SPINNING MACHINES Filed June 14, 1956 m 17 3A F 5 Sheets-Sheet 2 j E 4 I 26 O 5 r4 J? 25 as hi I 22 H M O O 4 If 6 o 2 7a 5 L T E #wmrap xh/wfi/ pfieifm lml 4f X41210;

May 2, 1961 KARL-HEINZ BREITENBACH 2,982,033

TEST APPARATUS FOR TEXTILE DRAFTING AND SPINNING MACHINES Filed June 14, 1956 3 Sheets-Sheet 3 Maw/9615 5 50 Un ted Stat Patent TEST APPARATUS FOR TEXTILE DRAFTING 9 SPINNING MACHINES Karl-Heinz Breitenbach, Stuttgart-Bad Cannstatt, Germany, assignor to SKF Kugellagerfabriken G.m.b.H.,

, Schweinfurt, Germany The present invention relates to textile machines' More particularly, the present invention relates to machines for drafting and spinning textiles. 1

With conventional machines for drafting and spinning textiles, it is necessary to test the roving before the drafting machine can be adjusted in conformity with the prop{ erties of the roving so as to produce the desired drafting as well as the desired subsequent spinning.

At the present time the apparatus and process for testing such rovings preparatory to drafting and spinning thereof are exceedingly disadvantageous. It is not feasible to adjust the drafting machine itself, because such adjustments would require an extremely long period of time and constant stopping and starting of the drafting machine. It is therefore customary to test the rovings on miniature drafting machines in conjunction with the subsequent spinning apparatus, but with such miniature machines it is also necessary to stop and start the machine constantly until the desired adjustments are determined. Furthermore, it is customary to determine the uniformity of the rovings before and after the drafting thereof, and the measurement of the roving is usually made-first before the roving passes through the drafting rolls and after .the roving passes through the drafting rolls. However, because of the changes which take place in the roving during the processing thereof a comparison between the measurements made before and after the drafting machine only gives confusing results, and the proper adjustment of the machine is exceedingly ditlicult to carry out. r

One of the objects of the present invention is to provide a drafting and spinning machine capable'of being adjusted during its operation in orderto processing of the textiles.

' Another object of the present invention is to provide a means for adjusting the speeds of rotation of all of the rolls of a given drafting machine in particular'combinations which will control both the predrafting; the main drafting, tthe total drafting, and the rate of delivery of provide proper yarn to the spinning part of the machine.

A further object of the present invention is to provide.

a structure for measuring'the uniformity 'of the textiles during the operation of the machine:

An additional object of the present invention is to pro vide a-'means for measuring the uniformity of the roving and yarn in' a manner which will simultaneously indicate, during operation .of the machine, the measure an apparatus capable of accomplishing all ofthe above objects and at the same time composed of. simple and ruggedly constructed elements which are very reliable in operation. a

] With the above objects in view the presentinvention mainly consists of a drafting. and spinning apparatus which includes a plurality, of drafting rolls locatedone behind the other along the drafting plane. An infinitely of the drafting machine proper.

2,982,083 Patented MayZ, .1961

variable drive is operatively connected to the rolls for changing the speeds of rotation of all of the rolls without changing their relative speeds of rotation and forindependently changing the speed of rotation of one roll with respect to the other rolls. Also, in accordance with the present invention a measuring means is provided for measuring the uniformity of the roving just ahead of the entrance roll of the drafting machine and just after the delivery roll thereof, 1

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The' invention itself, however, both as to its construction and its method of operation, to gether with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. l is a side elevational view on a relatively sm scale of a structure according to the present invention;

Fig. 2 is a schematicillustration of the structure. of Fig. l;

' Fig. 3 is a schematic illustration of a measuring means according to the present invention; and 1 v Fig. 4 is a schematic illustration of another embodiment of a measuring means according to the present inv'ention.

Referring now to Fig. 1, it will be seen that the struc; ture of the-invention includes a frame 1 which carries at a lower portion thereof a drive motor 2 connected to any suitable source of current, the frame 1 beingmade, for example, of welded sections of angle-iron. The drive motor 2 drives a stepped pulley 3 which through a V- be1t 5 drives another stepped pulley 4 which is operatively connected to a drum 6 supported for rotation about its axis by suitable bearings carried by the brackets 7 which are in turn ai'fixed to the frame 1 to be carried. thereby. A spindle driving band 8 is driven by the drum 6 and passes about the spindle 9 to drive the latter, and the band 8 is maintained tensioned by a roller pressing against the same andturnably carried by a bell crank 10 pivotally carried by a suitable support on the frame 1, the lower arm of this bell crank carrying at its left end, as viewed in Fig. 1, a weight which causes the roller to press against the band 8 to maintain the latter under ten- SlOl'l.

a The frame 1 additionally carries suitable support beams 11, which carry the

drives

12 and 13, a third drive 14 being carried by an upper portion of the frame 1. This upper portion of the frame also carries a creel 15 and another smaller frame 16 which supports the lower rolls Thus, the frame 16 turnably supports the lower entrance roll 17, the lower intermediate roll 18, and the lower delivery roll 19, these rollsbeing supported in a known way for rotation about their axes, respectively, and cooperating with unillustrated top r0118, respectively, which are supported in a conventional manner by a top rolls carrying arm which is pivotally supported adjacent its rear end by the frame 16.'

For the sake of clarity in Fig. l, the upper parts of'the drafting machine proper, the thread guide, the ring rail,

. and the drive for the latter are omitted from Fig. 1.

The shaft of the drum 6 which is fixed at one end to the stepped pulley 4, is fixed at its opposite end to a sprocket wheel 20 which cooperates with a sprocket chain 21 for driving a second sprocket wheel 22 which is fixed to the input shaft of the drive 12. Of course, sprocket wheels 20and 22 andchain 21 may be in the 'form of pulleys and a belt, respectively. The drive 12 includes in addition to its input shaft which is fixed to the sprocket wheel 22 anoutput shaft which fixedly carries a sprocket wheel 25, and the speed of rotation of the output-shaftof the drive 12 can be manually regulated infinitely by 3 l turning the hand wheel 23 which is fixed to a shaft supported for rotation about its axis by suitable bearings on the frame 1 and which is fixed to a sprocket wheel 24 which drives a sprocket chain connected to another sprocket wheel which turns a screw which extends into the driving mechanism 12 for infinitely varying, in a manner well known in the art, the drive to the output shaft in a completely stepless fashion. The sprocket wheel 25 cooperates with a sprocket chain 26 which drives a sprocket wheel 27 fixed to the delivery roll 19 of the drafting mechanism, so that by actuation of the hand wheel 23 the speed of rotation of the delivery roll 19 may be steplessly regulated. Also, the output shaft of the drive means 12 fixedly carries a sprocket wheel 28 which cooperates with a chain 29 which in turn drives a sprocket wheel 30 fixed to the input shaft of the drive means 13. In this way a drive is transmitted from the drive means 12 to the drive means 13.

This drive means 13 also includes an output shaft,

and the speed of rotation of this output shaft may be 2 infinitely varied by a manual actuation of the hand wheel '31 which turns a shaft supported for rotation about its axis by bearings on the frame 1 and which operates a sprocket chain 32 through a suitable sprocket wheel for turning a friction transmission device capable of providing an infinitely variable speed for the output shaft of the drive means 13, in the same way that actuation of the hand wheel 23 provides an infinitely variable speed for the output shaft of the drive means 12. The output shaft of the drive means 13 fixedly carries a sprocket wheel 33 which drives a sprocket chain 34 which in turn drives a sprocket'wheel 35 fixed to the entrance roll 17 of the drafting machine, so that the actuation of the hand wheel 31 can control the speed of rotation of the entrance roll 17 in a stepless fashion. Furthermore, the output shaft of the drive means 31 fixedly carries another sprocket wheel 36 which drives a sprocket chain 37 operatively connected to another sprocket wheel 38 fixed to the input shaft of the drive means 14, so that in this way the drive is transmitted from the drive means 13 to the drive means 14. The output shaft of the drive means 14 may have its speed infinitely varied by actuation of a hand wheel 39 fixed to a shaft supported for rotation about its axis by suitable bearings on the frame 1 and connected to a sprocket wheel which operates a chain 40 connected to another sprocket wheel which is connected to a screw for shifting a friction transmission member to provide a stepless variation in the speed of the output shaft of the drive means 14, in the manner described above. This output shaft of the drive means 14 fixedly carries a sprocket wheel 41 which drives a chain 42 which in turn cooperates with a sprocket wheel 43 fixed to the intermediate roll 18 of the drafting mechanism, so that by actuation of the hand wheel 39, the speed of rotation of the intermediate roll 18 can be regulated.

The above described structure of Fig. l is shown diagrammatically in Fig. 2 in a manner which clearly illustrates the arrangement of the infinitely variable drive means for transmitting the drive from the motor 2 to the several rolls of the drafting machine. In the diagrammatic illustration of Fig. 2, handwhecl 31 is shown at the left side of the apparatus for the sake of convenience. It is actually positioned as shown in Fig. 1.

By turning the hand wheel 23 in one direction or the other, the speed of rotation of the delivery roll 19 can be infinitely varied so as to increase or decrease the rate of delivery. Thus, more or less yarn is delivered from the delivery roll 19 to the spindle 9. Inasmuch as the speed of rotation of the spindle 9 does not change, the twist of the yarn increases or decreases in accordance with the rate of delivery. However, it will be noted that adjustment of the speed of rotation of the delivery The reason for this is that the drive means 12 which drives the roll 19 also transmits the drive to the drive means 13 which drives the roll 17, and from the drive means 13 the drive is transmitted to the drive means 14 which drives the intermediate roll 18. Therefore, when the speed of rotation of the delivery roll 19 is adjusted, the speeds of rotation of the

rolls

17 and 18 are also adjusted and the relative rotations of the rolls does not change so that the draft remains unchanged and only the rate of delivery is regulated.

By actuation of the hand wheel 31, the speed of rotation of the entrance roll 17 is regulated, and inasmuch as the drive means 13 transmits the drive to the drive means 14, the speed of rotation of the intermediate roll 18 also changes. However, the speed of rotation of the roll 19 does not change. Thus, by actuation of the hand wheel 31, the main draft which takes place between the

rolls

18 and 19 can be regulated. The predraft which takes place between the

rolls

17 and 18 does not change, however, because the relative speeds of rotation of these rolls remains unchanged. Thus, by actuation of the hand wheel 31, the predraft does not change, the main draft does change, and therefore the total draft changes in accordance with the change in the main draft.

If the hand wheel 39 is actuated, only the speed of rotation of the intermediate roll 18 can be changed in a stepless fashion. The speeds of rotation of the

rolls

17 and 19 remain unchanged, so that the total draft remains unchanged. Thus, if the speed of rotation of the roll 18 is changed so as to decrease the predraft, then the main draft will increase, and on the other hand if the speed of rotation of the roll 18 is regulated so as to decrease the main draft, then the predraft will increase.

The drive means 13 including the hand wheel 31 constitute therefore adjustment means for adjusting the main draft and the drive means 14 together with the hand wheel 39 constitute further adjustment means for adjusting the predraft together with the main draft.

Instead of providing a stepped pulley transmission between the motor 2 and the drum 6, it is possible to also provide an infinitely variable speed transmission between the motor 2 and the drum 6, so that with such an arrangement there is a fourth possibility of providing an infinitely variable change in the speed of the rollers. Furthermore, if desired, a suitable infinitely variable drive may be provided between the drum 6 and the spindle 9.

Fig. 3 shows schematically a means for measuring the uniformity of the roving as it is treated by the drafting o mechanism, as well as a means for indicating the measurements and a means for transmitting the measurements from the measuring means to the indicating means. The measuring means has a pair of stations respectively located before and after the drawing mechanism, and with the measuring means and indicating means it is possible to indicate simultaneously the condition of a portion of the yarn just before it enters the drawing mechanism and the condition of the same portion of the yarn after it' leaves the drawing mechanism.

Referring now to Fig. 3, a spool 44 carrying the roving 45 is located on the creel 15. An unillustrated frame fixedly carries a bar 46 which supports the drafting mechanism in a known way. This drafting mechanism includes a top rolls carrying arm 47 which carries in a 5 known way the upper pairs of

rolls

48, 49, and 50, and

then proceeds through the drafting mechanism, and then in the form of a yarn 54 passes through a second capacitor 60. The yarn then passes through a thread guide 55 to a traveller 56 on the ring rail 57 where the yarn is twisted, and then the yarn passes onto the spool 58 roll 19 does not in any way influence the draft itself. which is located on the spindle 9.

The capacitors I59 and 60 are respectively connected to apair-of

transmitters

61 and 62, and each transmitter includes a frequency modulating electron tube transmitter with simultaneous high frequency rectification. The low frequency signal which is produced by the rectification is transmitted from the transmitters 61- and 62 respectively to a pair of recording and reproducing

ampli tiers

63 and 64." In other words, each of these ampli fiers is actually a pair of amplifiers 'one of which is capable of amplifying signals to be recorded and the other of which is capable of amplifying signals to be reproduced, the

transmitters

61 and 62 being electrically connected to the recording channel of the

amplifiers

63 and 64. The recording channels of these amplifiers are electrically connected respectively to a pair of recording heads 65 and66 which cooperate with a magnetic recording tape 67 having a pair of tracks respectively cooperating with these recording heads which record on the-tracks lack of uniformity in the roving or yarn which produces frequencies greater than 20 cycles. The recording heads 65 and 66 are displaced from each other, as shown in Fig. 3. a Y

- The time which is required for a point on the track cooperating with recording head 65 totravel to a position where it is aligned with the recording head 66 must equal the time that it takes a point on the filament to travel from the capacitor 59 to the capacitor 60. In order to produce this result, the speeed ofmovement of the tape 67 may be made infinitelyvariable, while the distance between the recording heads 65 and 66 remain unchanged, or if the speed of movement of the tape 67 is fixed then suitable means may be providedfor regulating the distance between the recording heads 65 and 66; The speed of movement of the tape 67 may be varied by driving the roll 80 overwhich the tape 64 is guided by a motor 81 and by arranging a variable speed drive 82'of any well known construction in the transmission between motor 81 and roll 80 as schematically illustrated in Fig. 3. A pair of reproducing

heads

68 and 69 are located beside each other and pick up the frequencies recorded on the two tracks by the recording heads 65 and 66 and transmit these frequencies to the reproducing channels of the

amplifiers

63 and 64 respectively, from which these frequencies are transmitted to a pair of

meters

70 and 71 which indicate the frequencies, or the frequency may be transmitted withor without the

meters

70 and 71 to a pair of curve marking means 72 and 73 which are capable, in a known way, of marking curves on the moving strip 74, as indicated in Fig. 3.

Thus, with the arrangement of Fig. 3 it is possible to indicate simultaneously either on the

meters

70 or 71 and/or on the strip 74 the lackof uniformity in the roving just before the drafting mechanism and the lack of uniformity in the same portion of the roving as it leaves the drafting mechanism.

"According to the embodiment of the invention'which is'shown diagrammatically in Fig. 4, the capacitors 59 and 60 cooperate with the

transmitters

61 and 62 which in turn cooperate with the

amplifiers

75 and 76 to actuate atpair of curve marking means 77 and 78 which are displaced from each other along the moving strip 79, as indic atedin Fig. 4. Thus, a recording tape is not necessary with the embodiment of Fig. 4. With this embodiment either the speed of movement of the strip 79 is regulated sothat the'distance between a point marked with) the marking means 77 anda point marked with the marking means '78, along the length of the strip 79, corresponds to the distance between the capacitors 59 and 60 with respect to the movement of a portion of the yarn. In other words, by regulating the speed of movement of the strip 79, the portion of the yarnwhich is located between the plates of the capacitor 60 to actuate the recording means 78 provides a mark on the strip 79 which is located beside a mark on this strip previously provided by the marking means 77 when the same-p01"- eesaoss 6 tion of the yarn 'was in the form of airoving part located between the plates of the capacitor 59. Themeans of regulating the speed "of movement of the strip 79" may be constituted bya motor 83 driving, over a variable'speed drive 84 of any well known construction, the roll 85 whichengages the strip 79 to -move the latter in the direction of thear'row. 'Of course, if the speed of movement of the strip 79 remains unchanged, than a suitable means may be'provided for regulating the displacement of the marking means 77and 78 with respect to each other along the strip 79. Thus, with this embodiment of the 'invention it is also possible to show in side by side relation the lack of uniformity'of the roving andyarn before and after it is treated bythe drafting machine.

Although the invention has been described above intermediate, and delivery rolls, it is of course evident that the invention is also applicable to drafting-arrangements'where there is only one drafting zone andonly entrance and delivery rolls, but nointermediate rolls. With such an arrangement the' infinitely variable drivemeans is capable of varying the speed of rotationof the delivery rolls together with the entrance rolls without varying their relative speeds of rotation, and also theinfinitelyvariable drive means is capable of varying the speed of rotation of the "entrance rolls with respect to the delivery rolls. r 1 7 Also, the invention is applicable to drafting arrangements where a pair of intermediate rolls are located betweenthe entrance and the delivery rolls. With such an arrangement, the entrance and deliveryrolls are controlled in the manner described. above; However the speeds of rotation of both of these intermediate rolls are simultaneously controlled by the infinitely variable drive means with respect to the entrance and delivery rolls but the relative speed of rotation between a pair of intermediate rolls is maintained unchanged. A fourth drive means is provided to vary the speed of rotation ofone of the intermediate rolls with respect'to the other of the intermediate rolls.

Also, Where the drafting machine includes condensing rolls defining part of the condensing field, then a drive which is infinitely variable cooperateswith the condensing rolls for varyingthe speeds of all of these rolls without varying their relative speeds, so that the rate of movement of the yarn through the condensing rolls may be regulated but no draft is provided in these rolls.

Of course suitable erasing heads are provided to cooperate with the tape 67 before the recording head or after the reproducing heads 68and 69.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of textile machines diifering from the types described above.

While the invention has been illustrated and described as embodied in drafting and spinning machines, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. 1

Without further analysis, theforegoing will so fully reveal the gistof the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the changing their relative speeds for thus adjusting the rate of delivery; adjusting means operatively connected to said entrance roll means for changing the speed thereof with respect to said delivery roll means for thus adjusting the drafting speed; first measuring means located along the path of movement of a roving to said entrance roll means for measuring the uniformity of the roving to be drafted; second measuring means located along the path of movement of the roving from the delivery roll means for measuring the uniformity of the drafted roving; and adjustable indicating means for simultaneously indicating the uniformity of a portion of the roving to be drafted and the uniformity of the same portion of roving after being drafted regardless of the speed of said roll means. a

2. In a textile drafting machine, in combination, entrance roll means and delivery roll means; infinitely variable drive means operatively connected to both of said roll means for changing the speed thereof without changing their relative speeds for thus adjusting the rate of delivery; adjusting means operatively connected to said entrance roll means for changing the speed thereof with respect to said delivery roll means for thus adjusting the drafting speed; first measuring means located along the path of movement of a roving to said entrance roll means for measuring the uniformity of the roving to be drafted; second measuring means located along the path of movement of the roving from the delivery roll means for measuring the uniformity of the drafted roving; and adjustable indicating means for simultaneously indicating the uniformity of a portion of the roving to be drafted and the uniformity of the same portion of roving after being drafted regardless of the speed of said roll means, said adjustable indicating means including a pair of indicating instruments, and magnetc recording tape means for receiving the measurements from said measuring means and for transmitting the same to said indicating instruments, respectively.

3. In a textile drafting machine, in combination, entrance roll means and delivery roll means; infinitely variable drive means operatively connected to both of said roll means for changing the speed thereof without changing their relative speeds for thus adjusting the rate of delivery; adjusting means operatively connected to said entrance roll means for changing the speed thereof with respect to said delivery roll means for thus adjusting the drafting speed; first measuring means located along the path of'movement of a roving to said entrance roll means for measuring the uniformity of the roving to be drafted; second measuring means located along the path of movement of the roving from the delivery roll means for measuring the uniformity of the drafted rving; and adjustable indicating means for simultaneously indicating the uniformity of a portion of the roving to be drafted and the uniformity of the same portion of roving after being drafted regardless of the speed of said roll means, said adjustable indicating means including a pair of indicating instruments, magnetic recording tape means for receiving the measurements from said measuring means and for transmitting the same to said indicating instruments, respectively, and means for changing the speed of said magnetic recording tape means.

4. In a textile drafting machine, in combination, entrance roll means and delivery roll means; infinitely variable drive means operatively connected to both of said roll means for changing the speed thereof without changing their relative speeds for thus adjusting the rate of delivery; adjusting means operatively connected to said entrance roll means for changing the speed thereof with respect to said delivery roll means for thus adjusting the drafting speed; first measuring means located along the path of movement of a roving to said entrance roll means for measuring the uniformity of the roving to be drafted; second measuring means located along the path of movement of the roving from the delivery roll means for measuring the uniformity of the drafted roving; and adjustable indicating means for simultaneously indicating the uniformity of a portion of the roving to be drafted and the uniformity of the same portion of roving after being drafted regardless of the speed of said roll means, said adjustable indicating means including a pair of indicating instruments, magnetic record-v ing tape means including a pair of recording heads spaced an adjustable distance from each other along the tape of said magnetic recording tape means for respectively recording the measurements received from said measuring means on portions of the tape spaced from each other in direction of movement of the same, and a pair of reproducing heads cooperating with said tape for transmitting the recordings thereon to said indicating instruments, respectively.

5. In a textile drafting machine, in combination, entrance roll means and delivery roll means; infinitely variable drive means operatively connected to both of said roll means for changing the speed thereof without changing their relative speeds for thus adjusting the rate of delivery; adjusting means operatively connected to said entrance roll means for changing the speed thereof with respect to said delivery roll means for thus ad'- justing the drafting speed; first measuring means located along the path of movement of a roving to said entrance roll means for measuring the uniformity of the roving to be drafted; second measuring means located along the path of movement of the roving from the delivery,

roll means for measuring the uniformity of the drafted roving; and adjustable indicating means for simultaneously indicating the uniformity of a portion of the roving to be drafted and the uniformity of the same portion of roving after being drafted regardless of the speed of said roll means, said indicating means including a moving strip of sheet material, a pair of automatic marking means displaced along said strip in direction of its movement for respectively marking on said moving strip curves corresponding to said measurements taken by said measuring means, respectively, and means for regulating the speed of movement of said strip.

6. In a textile drafting machine, in combination, delivery roll means; entrance roll means; intermediate roll means located between said delivery and entrance roll means; variable drive means operatively, connected to said roll means for driving the same and for changing the speed of all of said roll means without changing their relative speed for thus adjusting the rate of delivery; adjustment means for changing the speeds of said entrance and intermediate roll means with respect to said delivery roll means while maintaining the relative speeds of rotation between said entrance and intermediate roll means for thus adjusting the main draft and further ad-. justment means for changing the speed of said intermedi-.

ate roll means Without changing the speeds of said entrance anddelivery roll means for thus adjusting the,

predraft together with the main draft; first measuring means located along the path of movement of a roving to said entrance roll means for measuring the uniformity.

means; infinitely variable drive means operatively connected to all of the roll means for changing the speed of.

all of said roll means without changing the relative speeds of said roll means for thus regulating the rate of;

9 10 delivery of the textile; adjustment means for changing References Cited in the file of this patent the speeds of said entrance and intermediate roll means with respect to said delivery r011 means while maintain- UNITED STATES PATENTS ing the relative speeds of rotation between entrance and 1,9 2,946 Litty June 6, 1933 said intermediate roll means for thus adjusting the main 5 2,16 9 Reich Aug. 8, 1939 draft; and further adjustment means for changing the 2,516,768 Grob et a1. July 25, 1950 speed of said intermediate roll means without chang- 2,671,199 Tmitt Mar. 2, 1954 ing the speeds of said entrance and delivery roll means 2,705,423 Strother et a1. -'Apr- 1955 for thus adjusting the predraft togetherwith the main draft. 10