US3443373A

US3443373A - Variable speed spinning frame

Info

Publication number: US3443373A
Application number: US602444A
Authority: US
Inventors: Morris M Bryan Jr
Original assignee: Jefferson Mills Inc
Current assignee: Jefferson Mills Inc
Priority date: 1966-11-21
Filing date: 1966-11-21
Publication date: 1969-05-13
Anticipated expiration: 1986-05-13

Description

May 13 1969 M. M. BRYAN, JR 3,443,373

I VARIABLE SPEED SPINNING FRAME I Filed Nov. 21, 1966 Sheet of 2 cu 7 m 52' 2' LL. Ll.

/ HIM! I 1' INVENTOR.

MORRIS M. BRYAN y 1969 I M. M. BRYAN, JR 3,443,373

VARIABLE SPEED SPINNING FRAME Filed Nov. 21, 1966 Sheet 2 of 2 l/VVEAUOP MORRIS 0. 00m; .142

United States Patent 3,443,373 VARIABLE SPEED SPINNING FRAME Morris M. Bryan, Jr., Jefferson, Ga., assignor to The Jefferson Mills, Inc., Jefferson, Ga., a corporation of Georgia Continuation-in-part of application Ser. No. 507,928,

Nov. 15, 1965. This application Nov. 21, 1966, Ser.

Int. Cl. D01h 13/00 US. Cl. 57-98 3 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to improvements in the spinning of yarn. More particularly, the present invention relates to an apparatus for improving the winding of a spun yarn on a bobbin during the spinning operation by varying the speed of the spinning operation. Three embodiments of the invention are disclosed and in all three embodiments the speed of a spinning frame is reduced when the winding operation is occurring at the lower most and uppermost ends of the bobbin. In addition, one embodiment provides for speed variations throughout the length of the bobbin which are responsive to both the progress of the total winding operation and the progress of each phase of the winding operation.

Cross reference to related application This application is a continuation-in-part of copending application Ser. No. 507,928, filed Nov. 15, 1965, now abandoned.

Disclosure In a conventional ring-spinning operation, a roving is drawn from a suitable supply roll and passed through a set of drafting rolls. From the drafting rolls the roving is passed through a pigtail guide and under a C-shaped traveler clipped to a horizontal spinning ring followed by winding upon a rotating bobbin. The spinning ring is stationary with respect to the rotating bobbin but has a limited up-and-down motion to traverse the length of the bobbin while winding the yarn thereon. The rotation of the bobbin relative to the yarn output speed under the ring traveler causes twist to develop in that portion of the yarn between the last drafting roll and the traveler.

In one type of winding in a ring-spinning operation the yarn is wound on the bobbin in ascending conically shaped layers. Yarn wound in this manner is intended for use in subsequent operations wherein the yarn is unwound in an axial direction to the bobbin. It is conventional practice in this type of winding to rotate the bobbin at a constant speed throughout the winding procedure. The drafting rolls are also rotated at a constant speed which is related to the rotational speed of the bobbin.

Certain disadvantages arise in high-speed winding of this nature on a spinning frame. The yarns tend to break or become gnarled and tangled when being wound on the two extreme ends of the bobbin However, the central portion of the bobbin may be wound at high speeds without the occurrence of problems of this type.

This breakage and gnarling of the yarn is apparently caused by three factors; the relative rotational speeds of the bobbin and the drafting rolls, the length of travel of the yarn between the drafting rolls and the spinning ring, and the degree of twist imparted to the roving in its travel from the drafting rolls to the spinning ring.

In winding a bobbin near its lowermost end, during the initial stages of winding, operating at high speeds will cause high tensile forces to be set up within the yarn apparently due to the combined effect of the above mentioned factors, with the predominant causes being the relatively high speed and the length of travel of the yarn. The degree of twist per unit length of the yarn is lowest in this area since the twisting is imparted to a greater length of the yarn, the segment of yarn between the drafting rolls and the spinning ring. As a result, the tensile forces may exceed the tensile strength of the yarn and breakage may occur.

As the high speed winding progresses upward on the bobbin the tensile forces set up within the yarn decrease due to the reduction in the length of travel of the yarn between the drafting rolls and the spinning ring (the spinning ring has moved closer to the drafting rolls). On the other hand, the degree of twist per unit length of the yarn begins to increase since the twisting is imparted to a shorter length of yarn. The change in the degree of twist in this area apparently does not have as significant an affect on the tensile forces as does the change in the length of travel of the yarn which explains why the tensile forces decrease in this region of winding. As a result, breakage and gnarling in this region is not frequently experienced.

Near the end of the high-speed winding operation at the uppermost part of the bobbin the length of travel of the yarn between the drafting roll and the spinning ring becomes relatively short. The twisting is confined to a much shorter length of yarn and a higher degree of twist is imparted thereto. It is believed that this high degree of twist becomes the dominating factor in determining the tensile forces in this region and, in combination with the other factors, causes high tensile forces to be set up within the yarn. Again, the tensile strength of the yarn is sometimes exceeded thereby resulting in breakage. Also, since a high degree of twist is present in the yarn, gnarling may sometimes occur.

In operation of the spining frame in the past these disadvantages have been virtually overcome by reducing the relative rotational speeds of the drafting rolls and the bobbins. With this reduction in speed the high tensile forces would not be developed. Therefore, in production, only those relative rotational speeds that produce a minimum number of broken and gnarled yarns are employed. These speeds are generally slow as are the corresponding production rates.

The present invention provides an apparatus wherein conventional spinning frames may be operated at higher production rates while remaining within the limits of the tolerable number of broken and gnarled yarns. In accomplishing these results it is provided that the drafting rolls and the bobbins of a spinning frame be driven at variable relative speeds during the spinning and winding operation. These speeds are varied to maintain at all times the highest operating speeds which are permissible within each region to prevent breakage of yarns.

From the following description it will be seen that the apparatus of the present invention may be easily employed with existing spinning frames with but minor modifications and adaptations.

These and other features and advantages of the present invention will become apparent from the following specification and the accompanying drawings in which:

FIG. 1 is a schematic representation of a first embodiment of the present invention in use with the conventional components of a spinning frame;

FIG. 2 is a schematic diagram illustrating control circuitry for that embodiment of the present invention shown in FIG. 1;

FIG. 3 is a schematic diagram illustrating control circuitry which provides a second embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating control circuitry which provides a third embodiment of the present invention.

Referring first to FIG. 1, there is shown the basic drafting, Spinning and winding units found on conventional spinning frames. It will be understood that a plurality of these units are positioned in spaced apart relationship within a single spinning frame. The single motor illustrated in FIG. 1 is used to drive all of the units which are present within a single spinning frame.

As illustrated, there is provided a roving 1 from a suitable supply source 2. The roving is led between two sets of drafting rolls 3 and 4. These sets of rolls are driven at suitable relative speeds to effect a drafting operation on the roving. For illustration purposes the uppermost rolls are shown as adjustable idler rolls while the lowermost rolls are driven from a common power source through appropriate individual gear reduction units.

From the drafting operation the roving emerges as an untwisted yarn 5 and is led through a pigtail guide 6 and through a traveler 7 slidably secured to the spinning ring 7 which is stationary relative to the rotation of the bobbin 8 and the motion of the traveler 7. The spinning ring 7' and the traveler 7 do have a limited up-and-down motion to cause ascending conical layers of yarn to be wound on the bobbin 8. This motion is imparted to the spinning ring by conventional mechanisms presently employed on spining frames and merely represented in FIG. 1 by numeral 10. The mechanism 10, of course, is driven by the same motor as are the previously described drafting rolls. Also, driven by this motor is the spindle 9 which imparts the rotational motion to the bobbin. For the sake of convenience the driving system of the spinning frame has been shown as a belt and pulley system 11 in combination with driving shafts 12 and suitable gear reduction units 13.

The apparatus described up to this point is present in conventional spinning frames. Such mechanisms are well known and understood by those skilled in the art.

As was pointed out previously, high rates of speed in the spinning frames cause the yarn to break and become gnarled when winding it upon the lowermost or the uppermost part of the bobbin. However, relatively no difficulty is encountered in winding at these speeds in the central portion of the bobbin. Unlike the prior operation wherein the spinning and winding of the yarn is accomplished at a safe constant speed, the present invention provides a method and apparatus which may be incorporated into the above described conventional spinning frames and will provide a. maximum safe rate of speed which varies throughout the spinning and winding operation. Specifically, speeds corresponding to the presently used speeds are provided near the lowermost and the uppermost end of the bobbin while a much higher rate of speed is provided in the central portion of the bobbin.

From the foregoing discussion it may be seen that the several components of the spinning frame may be driven at these varied speeds by merely varying the speed of the single drive motor. The speed of this drive motor is varied in accordance with the relative position of the spinning ring 7' with respect to the bobbin 8. Therefore, any control actuation device may be used which limits the speed of the motor when the spining ring 7 is adjacent either end of the bobbin while increasing the speed of the motor when the spinning ring 7 is adjacent the central portion of the bobbin.

There are a great many ways in which the driving speed of the spinning frame may be varied according to the positioning of the spinning ring relative to the bobbin. Merely by way of example, three ways of achieving this will be described below in connection with a DC motor. However, it will be realized that a great many different power sources and control means may also be used in keeping with the concept of the present invention.

As shown in FIG. 1, a DC. motor is employed to drive the spinning frame. One means of varying the speed of this motor is by attachment of a timer 20. This timer .4 is a conventional device well known in the art which may be pre-set to activate an electrical switch after the passage of predetermined periods of time. The electrical switch, in turn, controls the speed of the motor. The predetermined time periods correspond with the several winding regions on the bobbin.

The control circuitry for the use of the DC. motor and timer system is illustrated in FIG. 2. The DC. motor, as shown therein, is a shunt-wound motor having afield coil 21 and an armature 22. A resistor 23 is placed in optional series with the field coil 21. The switching mechanism 24 is provided in the field circuit wherein the resistance 23 may be either included or excluded from the circuit. The positioning of the switch 24 is controlled by timer 20 in accordance with the pre-set time conditions.

Since the speed of a shunt-wound motor is directly proportional to the strength of the field circuit decreases the amount of resistance in the field circuit decreases the field and consequently decreases the speed of the motor. Conversely, a decrease in the amount of resistance in a field circuit results in an increase in the strength of the field and also an increase in the speed of the motor.

In the operation of this control circuitry with a spinning frame employing a DC. motor, such as described with respect to FIG. 1, the timer is pre-set so as to provide a first position wherein switch 24 is placed in a position to include the resistance 23 in the field circuit. The motor is therefore operating at a decreased speed while the spinning and winding operation is initially started and the spinning ring 7' is at the lowermost end of the spool 8. The resistance 23 is so selected as to provide the motor with a suitable operational speed which has previously been found to be satisfactory in this region of the bobbin.

After the passage of a predetermined period of time the spinning ring 7 has reached a position corresponding to the central portion of the bobbin. The timer, which has been pre-set for this period of time, causes switch 24 to move to a new position excluding the resistance 23 from the field circuit. This results in an increase in the speed of the motor to a satisfactory operating level for the central portion of the bobbin.

Thereafter, when the spinning ring 7' reaches the uppermost portion of the bobbin and also at the end of a second predetermined period of time, the timer causes switch 24 to move back to a position wherein the resistance 23 is again included in the field circuit. A corresponding decrease in the speed of the motor results and the spinning frame slows to an operation within safe limits for this bobbin region.

The time required for each region of the bobbin to become filled with yarn may be easily computed from the known speeds at which the motor will operate and the known number of revolutions of yarn required to fill the region. These predetermined periods of time are those at which the timer is set prior to the operation.

Another form of the control circuitry which may be used with a DC). motor in accordance with the present invention is shown in FIG. 3. Again the DC. motor is shunt-wound and is indicated in the diagram by a field coil 31 and an armature 32. A rheostat 33 having relatively

high resistance portions

34 and 35 at its ends with a relatively low resistance portion 36 in the center is connected near its mid-point into the field circuit. A moveable contact 37 is provided that will sweep the entire length of the resistance element to change the resistance in the field circuit. It should be apparent that the speed of the motor will be varied as the moveable contact 37 traverses the resistant element.

Movement of the contact 37 may be effected by rotation of the armature 32. For example, a simple gearing arrangement may connect the contact 37 with the armature. Such gearing arrangements are Well within the skill of the art to construct. The number of revolutions of the armature is related to the revolutions required to fill the various regions of the bobbin with yarn. Therefore,

suitable gearing may be arranged correlating the traverse of the contact 37 with the number of revolutions required in each region.

In the operation of a spinning frame employing this form of the present invention the moveable contact 37 is initially set and the high resistant portion of the rheostat 33 so that the motor speed will be relatively low when the spinning and winding operation is initiated on the bobbin. After a predetermined number of revolutions of the armature 32, which correspond to that required for the lower portion of the bobbin to become filled with yarn and the spinning ring 7' to move to a position opposite the central portion of the bobbin, the moveable contact 37 will traverse the high resistance portion and move into the low resistance portion 36 thereby increasing the speed of the armature and the operating speed of the spinning frame. After another predetermined number of revolutions of the armature, which correspond to that required for the central portion of the bobbin to fill with yarn, the movable contact 37 will traverse the high resistance portion and move into the low resistance portion 36 thereby increasing the speed of the armature and the operating speed of the spinning frame. After another predetermined number of revolutions of the armature, which correspond to that required for the central portion of the bobbin to fill with yarn and the spinning ring 7' to move opposite the upper portion of the bobbin, the movable contact 37 will move into the opposite high resistance portion of the rheostat thereby reducing the speed of the armature. With this mechanism, the spinning frame will operate to wind the yarn at a relatively low safe speed at either end of the bobbin while winding at a relatively high safe rate of speed in the central portion of the bobbin.

That third embodiment of the invention shown in FIG. 4 is similar to that embodiment of the invention shown in FIG. 2 in that a timer 20' is used to activate an electrical switch 24 after the passage of predetermined periods of time so as to vary the resistance in the field circuit of the motor and the speed of the motor and spinning frame. However, unlike that embodiment of the invention shown in FIG. 2, in that embodiment of the invention shown in FIG. 4, a plurality of

resistors

41, 42 and 43 are selectively placed in the field circuit of the motor as the winding operation required to wind yarn 5 on a bobbin 8 progresses and the resistor 43 is in the field circuit when the winding operation is at the uppermost end of the bobbin 8. These

resistors

41, 42 and 43 progressively decrease in resistance value and as a result, in that embodiment of the invention shown in FIG. 4, the operation of the switch 24' in response to the timer 20' progressively increases the speed of the spinning frame throughout the winding operation so as to provide the maximum operating speed when the winding operation is at the uppermost end of the bobbin 8.

In that embodiment of the invention shown in FIG. 4, the reduced speed of the spinning frame required when the winding operation is at the uppermost end of the bobbin 8 in order to limit yarn breakage is provided by placing the resistor 43 in series with a resistor 45 and a wiper 46 which serve together to vary the resistance in the field circuit of the motor in accordance with the position of the wiper 46 on the resistor 45 in conventional manner. The operation of the resistor 45 and the wiper 46 will be understood by those skilled in the art when it is remembered that in the winding of ascending conical layers of yarn on a bobbin 8, the mechanism 10 moves the spinning ring 7 upwardly along the length of the bobbin 8 in a series of steps during each of which the spinning ring 7 moves a limited distance upwardly and downwardly in a zone of motion along the length of the bobbin 8. The resistor 45 and the wiper 46 are arranged so that substantially all of the resistor 45 is in the field circuit of the motor when the spinning ring 7' is in its uppermost position within a zone of motion and so that substantially none of the resistor 45 is in the field circuit of the motor when the spinning ring 7' is at its lowermost position within a zone of motion. Thus, during those zones of motion of the spinning ring 7' which occur during that portion of the winding operation at the uppermost end of the bobbin 8, the speed of the spinning frame is reduced by the progressive adding of the resistor 45 to the field circuit of the motor as the spinning ring 7' moves upwardly toward the uppermost end of the bobbin 8.

It will now be understood that in all three embodiments of the invention disclosed herein, there is a resistance in the field circuit of the motor which serves to reduce the speed of the spinning frame both when the winding operation is occurring at the lowermost end of the bobbin and when the winding operation is occurring at the uppermost end of the bobbin. However, with that embodiment of the invention shown in FIG. 4, the

resistors

41, 42, 43 and 45 not only serve to reduce the speed of the spinning frame when the winding operation is occurring at the uppermost end and the lowermost end of the bobbin 8 but also to decrease the speed of the spinning frame each time the winding operation moves upwardly in the central portion of the bobbin 8 within a zone of motion of the spinning ring 7.

The motion of the wiper 46 relative to the resistor 45 which is required to control the speed of the spinning framewithin a step of the spinning ring 7 along the length of a bobbin 8 is readily achieved by simply arranging the mechanism 10 which controls the motion of the spinning ring 7' relative to the bobbin 8 so that motion of the wiper 46 relative to the resistor 45 occurs within a zone of motion of the spinning ring 7' and so that there is no relative motion between the resistor 45 and wiper 46 between steps. Those skilled in the art will recognize that there are many such arrangements of the mechanism 10 which are possible on a spinning frame such as mounting the resistor 45 on the stationary frame (not shown) of the spinning frame and mounting the wiper 46 on a bell crank (not shown) of the spinning frame which moves upwardly and downwardly in a manner corresponding to the motion of the spinning ring 7 within each zone of motion of the spinning ring 7. Moreover, it will also be understood that the wiper 46 and the resistor 45 may be replaced with a plunger movable relative to a coil and other similar arrangements which cause electrical changes in response to the position of the spinning ring 7 within a zone of motion.

It will be understood that by varying the values of the resistances in either form of the present invention, as above described, the size of the regions of relatively slow or fast winding may be varied.

The concepts of the present invention are extremely broad and may be employed with numerous types of drive systems for spinning frames. Additionally, depending upon the particular drive system employed, numerous speed control systems may be employed. It should, therefore, be understood that the above described systems have been mentioned only to serve as examples of the present invention.

What is claimed as invention is:

1. A spinning frame comprising drafting rolls, spinning rings, bobbins, and a single drive means for driving all of the bobbins, said drive means comprising an electrical shunt-wound DC. motor, and control means comprising a variable resistance switching mechanism connected in the field circuit of the motor and a timer connected to the switching mechanism for periodically actuating the switch to vary the resistance in the field circuit.

2. A spinning frame comprising drafting rolls, spinning rings, bobbins, and a single drive means for driving all of the bobbins, said drive means comprising an electrical shunt-wound D.C. motor, and control means comprising a variable resistance switching mechanism connected in the field circuit of the motor and means connecting the output drive means of the motor with the switching mechanism for varying the resistance in the field circuit while the motor is in operation.

3. A spinning frame comprising drafting rolls, spinning rings, bobbins, and single drive means for driving all of the bobbins, said drive means comprising an electrical shunt-wound DC. motor, and control means comprising a variable resistance switching mechanism connected in the field circuit of the motor and means connecting the armature of the motor with the switching mechanism for varying the resistance in the field circuit While the motor is in operation.

References Cited UNITED STATES PATENTS Regnault 5795 Triou 5795 Runner 5795 Korokochi et a1. 5798 Reich 5797 Snyder 5795 XR Potts 5793 XR Bucher 5793 U.S. Cl. X.R.