US2713980A

US2713980A - Traverse mechanism

Info

Publication number: US2713980A
Application number: US255642A
Authority: US
Inventors: Samuel B Roberts; Robert H Roughsedge; Edelman Abraham; George E Koslow
Original assignee: Celanese Corp
Current assignee: Celanese Corp
Priority date: 1951-11-09
Filing date: 1951-11-09
Publication date: 1955-07-26
Anticipated expiration: 1972-07-26

Description

July 26, 1955 s. B. ROBERTS ET AL TRAVERSE MECHANISM 2 Sheets-Sheet 1 Filed NOV. 9, 1951 INVENTORS. SAMUEL B. R

ERTS MAN OB EL ROBERT H. ROUGHSEDGE GEORGE E. KOSLOW W ABRAHAM ED TRAVERSE MECHANISM Filed NOV. 9, 1951 2 Sheets-Sheet 2 a 2mm 67 INVENTORS. 77 I SAMUEL B. ROBERTS ABRAHAM EDELMAN ROBERT H. ROUGHSEDGE 7g GEORGE E. KOSLOW WQT OI-QN EYS.

nited States Patent Ofilice 2,713,980 Patented July 26, 1955 TRAVERSE MECHANISM Samuel B. Roberts, Greenwich, Conn, Robert H. Roughsedge, Ramsey, N. 3., and Abraham Edelrnan and George E. Koslow, New York, N. Y., assignors to Celanese Corporation of America, New York, N. Y., a corporation of Delaware Application November 9, 1951, Serial No. 255,642

9 Claims. (Cl. 242158) This invention relates to a traverse mechanism and relates more particularly to a traverse mechanism for use in the winding of yarn at high speeds.

In the packing of yarn and the like, such as yarn, filaments, threads, wire, etc., all of which will hereinafter be referred to as yarn, it is a common practice to wind said yarn into a so-called cross-wound packing in which the turns of yarn lie on the package at a relatively large angle. Usually, these packages are headless, that is they are not provided with end flanges to support the yarn, but. depend upon the rigidity of the winding itself to maintain the shape of the package. The most widely employed yarn packages of this type are cones and cheeses.

The winding machines that are employed for the production of cross-wound packages are equipped with a traverse mechanism operatively connected to a yarn guide, which traverse mechanism reciprocatcs back and forth along the length of the package to guide the yarn onto the package at the desired angle. These traverse mechanisms are generally operated by means of cams or other mechanical means. If an attempt is made to carry out the winding operation at high speeds, it is found that these mechanical traverse mechanisms are inadequate owing either to excessive Wear or excessive stresses that are imposed upon the parts thereof when the traverse speed exceeds a certain value. As a result, it is not possible to operate these traverse mechanisms above certain speeds, which thereby limits the maximum winding speeds that can be employed in the production of cross-wound packages.

Among the difficulties that are frequently encountered with the conventional mechanical traverse mechanisms is the tendency of the yarn windings to cross-thread and to ribbon. Cross-threading occurs when, owing to the relatively slow reversal of the traverse mechanism at the end of its stroke, an important fraction of a turn of yarn is wound onto the end of the package Where it can fall out. A yarn package in which such falling out has occurred is difficult to unwind smoothly, if such unwinding can be successfully accomplished at all. Ribboning is the result of the tendency of the traverse mechanism to operate at such a ratio to the speed of rotation of the yarn package, at one or more times during the winding of the said package, as to lay a number of yarns almost on top of one another. This produces a yarn package having an uneven surface and causes yarn slippage and loose packages. Ribboning also permits interlocking of the turns of yarn which prevents easy unwinding of the yarn package.

It is an important object of this invention to provide a traverse mechanism which will be free from the foregoing and other disadvantages and which will be especially simple in construction and efiicient in operation.

A further object of this invention is to provide a traverse mechanism in which electrical means are employed to provide the desired reciprocatory motion of the yarn guide.

Another object of this invention is to provide a traverse mechanism in which elastic or resilient means are provided at each end of the traverse stroke to cause a rapid reversal of the direction of motion of the yarn guide.

Other objects of this invention, together with certain details of construction and combinations of parts, will be apparent from the following detailed description and claims.

According to the present invention, there is provided, in a traverse mechanism having a reciprocating element operatively connected to a yarn guide, an elastic member positioned at each end of the traverse stroke. The reciprocating element strikes the elastic member at each end of its stroke, compressing the same and thereby converting its kinetic energy of motion into potential energy of the compressed elastic member. The elastic member stops the reciprocating element and then expands, returning its potential energy to the reciprocating element in the form of kinetic energy of motion and causing said reciproeating element to move toward the opposite end of its traverse stroke. By means of this construction, there is obtained a rapid reversal of the reciprocating element at each end of its stroke without the imposition on any mechanisms of excessive stresses. The reciprocating element need not strike the elastic member directly, but may act thereon indirectly through any suitable means such as a linkage or the like. Also, the elastic member may be carried by the reciprocating element.

To operate successfully, the elastic members must be designed so as to be capable of sufficient compression to convert substantially all the kinetic energy of the reciprocating element into the form of potential energy. If the elastic members are not capable of this, as, for example, if stops are provided which will limit the compression of the elastic members the kinetic energy of the reciprocating element will not be all substantially converted to potential energy and will not be returned to the reciprocating element through the expansion of the elastic members. The stresses developed in the elastic members should, of course, be less than the elastic limit of the material of which they are constructed to avoid producing a permanent set in said members. The elastic members should be supported solidly in such a manner that there is no tendency for any movement of their supported portions relative to their supports to take place which would prevent the kinetic energy of the reciprocating element from being converted to potential energy of the elastic members. Advantageously, the elastic members should be designed so as to supply at least about one-third and preferably at least about two thirds of the energy required to start the movement of the reciprocating element from one end to the other end of its traverse stroke.

During the movement of the reciprocating element through its traverse stroke, certain unavoidable losses take place as the result of friction, windage and the like which will tend to slow down and finally stop the reciprocating element. To compensate for these losses, means are provided which will furnish energy to the reciprocating element in timed relation to its movement through the traverse stroke. These means may be electrical in nature and may take the form of electromagnets operating on a portion of the reciprocating element which is constructed of a magnetic material. For eX- ample, the reciprocating element may comprise a permanently magnetized cylinder which is supported slidably between two solenoid coils that may be energized so that each solenoid coil alternately attracts and repels the pole of the magnet adjacent thereto. The elastic members may comprise helical springs extending into the core of the solenoid coils so that the magnet will strike the same at each end of its traverse stroke. The solenoid coils may be energized with alternating current having a frequency equal to the desired traverse rate or with direct current whose direction is reversed at the desired rate, as, for example, by means of a commutator. The solenoid coil which attracts the magnet will tend to increase its degree of magnetization. However, the solenoid coil which repels the magnet will tend to demagnetize the same. To prevent any change in the strength of the magnet, it may be desirable to design the apparatus so that a smaller current will flow through the solenoid coil which is repelling the magnet. Instead of having two solenoid coils, a single solenoid coil may be employed alternately to repel and attract the magnet.

The traverse mechanism may also be operated with a soft iron bar in place of the permanent magnet. In this case, the solenoid coils are energized alternately to attract the end of the iron bar adjacent thereto. To obtain the most eflicient use of electrical energ the solenoid coils should be energized so that they both tend to magnetize the iron bar in the same direction. In general, the reciprocating element is not positively connected to the means furnishing energy thereto to overcome losses.

The reciprocating element tends to move through its traverse stroke at a substantially constant velocity due to inertia. If the losses that take place during its movement are compensated for by the energy added thereto, the velocity will remain substantially constant throughout its stroke producing a uniformly wound package. For some purposes, it may be desirable to vary the velocity of the reciprocating element or to vary the amount of energy supplied thereto during its traverse stroke which may be accomplished readily, for example, by changing the amount of current supplied to the solenoid coils. This change in current may be effected by the use of a suitably designed alternating current generator or by means of a suitable commutator arrangement.

Because there is no fixed relationship between the frequency of the traverse motion and the speed of rotation of the yarn package, the tendency for ribboning to occur is reduced to a minimum. Substantially to prevent all ribboning, there may be provided means for varying the frequency of the traverse motion at frequent intervals during the winding operation in accordance with some predetermined program. This variation may, for example, be accomplished by changing the frequency of the current through the solenoid coils in accordance with the desired changes in the frequency of the traverse motion. When the changes in the frequency of the traverse motion are relatively large, means may be provided for simultaneously changing the current through the solenoid coils so that it will be at the optimum value for each frequency. The change in the frequency of the traverse motion not only eliminates substantially all tendency toward ribboning, but also prevents the development of resonant motions in the elastic members which might lead to fatigue failures in said members.

A single power supply may be used to provide current for a large number of traverse mechanisms which may be located at some distance from the power supply. This arrangement is particularly advantageous when the traverse mechanisms are to be operated in a hazardous atmosphere since it enables a great deal of the electric equipment to be removed from said atmosphere. The equipment, or part of it, may be constructed for operation in a hazardous atmosphere by sealing the same from contact with said atmosphere.

The winding apparatus with which the traverse mechanism of this invention is employed may be of any suitable construction of which there are many types known in the art. It may drive the yarn package through frictional contact with the surface thereof or it may drive the spindle on which said yarn package is supported The windlng apparatus may operate at a constant rotational speed or it may drive the yarn package at a constant peripheral speed.

The traverse mechanism of this invention will now be described specifically as applied to the winding of a plurality of yarn windings on a single yarn package support. It may, however, also be employed for the winding of a single yarn winding on a yarn package support.

A preferred embodiment of this invention is shown in the accompaying drawings wherein:

Fig. l is a plan view of the traverse mechanism,

Fig. 2 is a cross-sectional view, taken along the line 2-2 in Fig. l, in the direction of the arrows,

Fig. 3 is a detail cross-sectional view, taken along the line 3-3 in Fig. l, in the direction of the arrows,

Fig. 4 is a detail cross-sectional view, taken along the lines 4-4 in Fig. l, in the direction of the arrows,

Fig. 5 is a schematic circuit diagram of the electric wiring of the traverse mechanism,

Fig. 6 is a view showing a cross-wound yarn package free from ribboning, and

Fig. 7 is a view showing a cross-wound yarn package in which ribboning has taken place.

Referring now to the drawings, the reference numeral 11 designates a base plate to which is securely fastened an upright 12. Mounted on the upright 12 are a pair of pillow blocks 13 in which is journalled for rotation a shaft 14 carrying a cork roll 15. The shaft 14 supports an adjustable sheave 16 driven by the V-belt 17 from motor-pulley 18 and motor 19. A knurled head screw 21 threaded into supporting bracket 22 mounted on the upright 12 enables the effective diameter of the pulley 16 to be adjusted over a considerable range whereby the speed of rotation of the shaft 14 and the cork roll 15 may be varied.

Another upright 23 fastened to the base plate 11 has mounted thereon a pillow block 24 in which is journalled for rotation a shaft 25. Mounted on the shaft 25 is bifurcated arm 26 carrying spindle shaft 27 which supports spindle chuck 28 adapted to engage and hold yarn package supporting tube 29 on which a pair of

yarn windings

31 and 32 are to be formed. The yarn package supporting tube 29 is driven at a constant peripheral speed by frictional contact between the said tube, or the

yarn windings

31 and 32 thereon, and the cork roll 15. To regulate the pressure with which the yarn package supporting tube 29, or the

yarn windings

31 and 32, bear against the cork roll 15, there is mounted on the shaft 25 an arm 33 to which a counterweight 34 is adjustably secured by means of a set screw 35. Also fastened to the shaft 25 is an arm 36 which is secured by means of a pin 37 and a clevis 38 to plunger 39 of a hydraulic dashpot 41 which serves to keep the spindle shaft 27 and the elements supported thereon from bouncing away from contact with the cork roll 15.

Yarns

42 and 43, from any suitable source (not shown), are guided to form the

yarn windings

31 and 32, respectively, by means of a traverse mechanism, indicated generally by reference numeral 44. The traverse mechanism 44 comprises a cylindrical permanent magnet 45 which is slidably mounted between a pair of spaced solenoid coils 46 and 47 that are each provided with a liner of nonmagnetic material 48 that serves as a bearing for the magnet 45. Positioned adjacent the outer ends of the

solenoids

46 and 47, respectively, are heavy metal blocks 49 and 51 that are fastened securely to the upright 12. The

blocks

49 and 51 carry

springs

52 and 53 that project into the hollow cores of the

solenoids

46 and 47, respectively. As shown in Figure 4, the

springs

52 and 53 are threaded onto the heads of screws 54 that extend into the supporting blocks and the said springs are held in place by means of set screws 55.

Fastened to the magnet 45 is a strap 56 to one end of which is secured a counterweight 57 and to the other end of which is secured a cross-arm 58 that carries a pair of self-threading yarn guides 59 and 61 that guide the'ya'rns 42 and 43 to form the yarn packages 31 and 32. To prevent rotation of the strap 56 and to maintain the yarn guides 59 and 61 properly positioned, there is provided a bracket 62 which extends outwardly from the upright 12. Fastened to the bracket 62 is a half-round bar 63 which is recessed to form a Slot 64 through which the strap 56 extends and which prevents rotation thereof. The counterweight 57 prevents the development of unbalanced inertia forces in the traverse mechanism during the reverse of movement of the magnet 45.

The

solenoids

46 and 47 are energized by means of the electrical circuit shown in Figure 5 of the drawings to traverse the magnet and the yarn guides 59 and 61 operatively connected thereto back and forth. Referring now to this figure, there are provided a pair of direct current power terminals 65 and 66 from which a current flows to switching motor 67 comprising a field coil 68 and an armature 69. Mounted on the shaft of the switching motor 67 is a commutator 71 and

slip rings

72 and 73 which are connected to the solenoid coils 46 and 47. Current fiows from the power terminals 65 and 66 to the solenoid coils 46 and 47 by way of the commutator 71 and the slip rings 72 and 73 through a voltage divider network, indicated generally by reference numeral 74 and comprising a variable resistor 75, whose function will be described more fully hereinafter, a variable resistor 76, which permits the current through said coils to be regulated, and a pair of fixed

resistors

77 and 78. Sparking of the commutator 71 and the slip rings 72 and 73 is effectively prevented by means of a pair of capacitors 79 connected across the solenoid coils 64 and 47.

The direction of the flow of the current through the solenoid coils 46 and 47, and the polarity of the magnetic field generated by said solenoid coils, is reversed periodically by the rotation of the commutator 71 and the slip rings 72 and 73. This reversal in the polarity of the magnetic field causes each of the solenoid coils 46 and 47 alternately to attract and repel the end of magnet 45 adjacent thereto, thereby moving the said magnet, and the yarn guides 59 and 61 operatively connected thereto, back and forth. At the end of its stroke, the magnet 45 will strike one of the

springs

52 or 53 and will compress the said spring converting the kinetic energy of said magnet into potential energy in said spring. Then, the spring expands, returning the potential energy, nearly without loss, to the magnet 45 and causing the said magnet to move in the opposite direction. At the other end of its stroke, the magnet 45 will strike the other of the

springs

52 or 53 and the process will be repeated. Because of the storage and return to the system of the energy in the magnet 45 by the

springs

52 and 53, the solenoid coils 46 and 47 only have to furnish sufficient energy to the magnet 45 to overcome the frictional, windage and like losses in the moving system comprising the magnet 45 and the elements connected thereto rather than the entire energy needed to effect the traverse motion.

The solenoid coil which is attracting the magnet 45 will tend to strengthen the magnetization of said magnet. However, the solenoid coil which is repelling the magnet 45 will tend to demagnetize the said magnet. To prevent any such demagnetization from taking place, there is provided a resistor 80 which shunts the

solenoid coil

46 or 47 which is repelling the magnet 45, thereby reducing the current through the said solenoid coil and limiting the magnetic field thereof to a safe value.

To change the frequency of the traverse motion, the speed of the switching motor 67 is altered by adjusting the rheostat 81 which is connected in series with the armature 69 of said motor. In starting up the traverse mechanism, it may be desirable to build up the frequency of the traverse motion gradually by bringing the switching motor up to speed slowly. This may be achieved simply, for example, by connecting carbon filament lamps 82 in series with the armature 69. The carbon filament lamps exhibit a negative temperature-coefiicient of resistance so that 6 the current through them increases gradually as they heat up causing the speed of the motor 67 to increase gradu ally during the start-up period.

Ribboning is effectively prevented by changing the frequency of the traverse motion periodically. To achieve this change, there is provided a timer 83 which alternately opens and closes a contact 84 connected across a rheostat 85 in series with the armature 69. When the contact 3 closes, the rheostat is shorted out of the armature circuit and the speed of the switching motor 67 increases causing the frequency of the traverse motion to increase. On the other hand, when the contact 84 opens, the speed of the switching motor 67 and the frequency of the traverse motion decrease. The change in the frequency of the traverse motion caused by the opening and closing of the contact 84 may be regulated by adjusting the rheostat 85.

When the change in the frequency of the traverse motion caused by the opening and closing of the contact 84 is relatively large, it is desirable to adjust the current fiowing through the solenoid coils 4 6 and 47 to the optimum value for each frequency. This adjustment may be effected readily by means of a contact 86 in the timer 83 which opens and closes synchronously with the contact 84 and is connected across the rheostat 75. When the contact 86 closes, it shorts out the rheostat 75 so that the current through the solenoid coils 46 and 47 will increase. On the other hand, when the contact 86 opens the current through the solenoid coils 46 and 47 will decrease.

During operation, the motor 19 drives the cork roll 15 at a constant peripheral speed causing the yarn packages 31 and 32 to rotate at a constant peripheral speed to wind the

yarns

42 and 43 thereon. The

yarns

42 and 43 are cross-wound onto the yarn packages 31 and 32 by the traverse mechanism 44 without cross-threading. In addition, because of the periodic changes in the frequency of the traverse motion, the final yarn package will be free from ribboning as shown at 37 in Fig. 6 of the drawings. Yarn packages produced with conventional traverse mechanisms, on the other hand, exhibit ribboning as shown in the package 88 in Fig. 7 of the drawings in which a plurality of yarns are wound closely adjacent to one another as at 89 to produce a rough, irregular spot in said yarn package.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. In a traverse mechanism, the combination with a reciprocating element comprising a magnet operatively connected to a yarn guide, of electromagnetic means acting alternately to attract and repel each pole of said magnet for moving said reciprocating element through its traverse stroke, said electromagnet means including resistance means to produce a smaller force when tending to repel said magnet than when tending to attract said magnet whereby the tendency to demagnetize said magnet is kept at a minimum.

2. In a traverse mechanism, the combination with a reciprocating element operatively connected to a yarn guide, of electrical means for moving said reciprocating element through its traverse stroke by means of a series of electrical pulses, and means for periodically and automatically changing the frequency of the electrical pulses to change the frequency of the traverse motion.

3. In a traverse mechanism, the combination with a reciprocating element operatively connected to a yarn guide, of elastic members positioned in the path of the reciprocating element and arranged to be struck thereby at the end of the traverse stroke of said reciprocating element to stop and reverse the direction of movement of the said reciprocating element, and means for periodically and automatically changing the frequency of the traverse motion.

4. In a traverse mechanism, the combination with a reciprocating element operatively connected to a yarn guide, of elastic members positioned in the path of the reciprocating element and arranged to be struck thereby at the end of the traverse stroke of said reciprocating element to stop and reverse the direction of movement of the said reciprocating element, means for supplying sufficient energy to the reciprocating element in timed relation to its motion to overcome the energy losses tending to slow down said reciprocating element, and means for periodically and automatically adjusting said energy supplying means for changing the frequency of the traverse motion.

5. In a traverse mechanism, the combination with a reciprocating element comprising a magnet operatively connected to a yarn guide, of elastic members positioned in the path of the reciprocating element and arranged to be struck thereby at the end of the traverse stroke of said reciprocating element to stop and reverse the direction of movement of the said reciprocating element, and solenoids acting alternately to attract and repel the magnet for supplying sufiicient energy to the reciprocating element in timed relation to its motion to overcome the energy losses tending to slow down said reciprocating element, and means for periodically and automatically adjusting the frequency of the current to said solenoids for changing the frequency of the traverse motion.

6. In a traverse mechanism, the combination with a reciprocating element comprising a magnet operatively connected to a yarn guide, of elastic members positioned in the path of the reciprocating element and arranged to be struck thereby at the end of the traverse stroke of said reciprocating element to stop and reverse the direction of movement of the said reciprocating element, and solenoids acting alternately to attract and repel the magnet for supplying sufficient energy to the reciprocating element in timed relation to its motion to overcome the energy losses tending to slow down said reciprocating element, and means for periodically and automatically adjusting the frequency of the current to said solenoids for changing the frequency of the traverse motion, said solenoid means including resistance means to produce a smaller force when tending to repel said magnet than when tending to attract said magnet whereby the tendency to demagnetize said magnet is kept at a minimum.

7. In a traverse mechanism, the combination with a cylindrical magnet, of a pair of solenoid coils slidably supporting said magnet acting alternately to attract and repel each pole of said magnet for moving said reciprocating element through its traverse stroke, a pair of springs positioned at the ends of the traverse stroke in the path of the magnet and arranged to be struck thereby to stop and reverse the direction of movement of the magnet, and means for periodically and automatically adjusting the frequency of the current to said solenoids for changing the frequency of the traverse motion.

8. In a traverse mechanism, the combination with a cylindrical magnet, of a pair of solenoid coils slidably supporting said magnet acting alternately to attract and repel each pole of said magnet for moving said reciprocating element through its traverse stroke, a pair of springs positioned at the ends of the traverse stroke in the path of the magnet and arranged to be struck thereby to stop and reverse the direction of movement of the magnet, and means for periodically and automatically adjusting the freqeuncy of the current to said solenoids for changing the frequency of the traverse motion, said solenoid means including resistance means to produce a smaller force when tending to repel said magnet than when tending to attract said magnet whereby the tendency to demagnetize' said magnet is kept at a minimum.

9. In a traverse mechanism, the combination with a cylindrical magnet, of a pair of solenoid coils slidably supporting said magnet acting alternately to attract and repel each pole of said magnet for moving said reciprocating element through its traverse stroke, a pair of springs positioned at the ends of the traverse stroke in the path of the magnet and arranged to be struck thereby to stop and reverse the direction of movement of the magnet, and means for periodically and automatically adjusting the frequency of the current to said solenoids for changing the frequency of the traverse motion, and means for simultaneously and automatically varying the current to the solenoids to the optimum value for each frequency, said solenoid means including resistance means to produce a smaller force when tending to repel ,said magnet than when tending to attract said magnet whereby the tendency to demagnetize said magnet is kept at a minimum.

References Cited in the file of this patent UNITED STATES PATENTS 400,809 Van Depoele Apr. 2, 1889 618,702 Mason Ian. 31, 1899 734,424 Loring July 21, 1903 792,571 Christmas June 13, 1905 1,120,414 Schoolfield et a1. Dec. 8, 1914 1,469,470 Wright Oct. 2, 1923 1,522,821 Jones et al. Jan. 13, 1925 1,764,618 Franks June 17, 1930 1,916,942 Wright July 4, 1933 1,970,412 Bates Aug. 14, 1934 2,109,953 Bates Mar. 1, 1938 2,320,554 Barrett June 1, 1943 2,548,523 Dyer et a1. Apr. 10, 1951