ASSEMBLIES

BACKGROUND OF THE INVENTION

1. Field of the Invention:

The present invention relates to textile spindle assembly. In particular, the present invention relates to the use of magnetic forces to stabilize a pot of a textile spindle assembly.

2. Discussion of Background:

In the textile industry, spindles are used for twisting or cabling two or more threads together to form yarn. Typically, the spindle assembly comprises a stationary pot with supply package housing a spool of thread riding freely on a spindle that rotates. The pot is prevented from rotating by an oblique bearing assembly within the spindle. During the process of twisting or cabling, one or more threads is brought through the spindle either from an external supply creel through a series of guides or from the pot itself. During the twisting or cabling process, the thread from the spindle flares or "balloons" radially as a result of the centrifugal forces on it as applied from the rotating spindle, but limited in its radially outward direction by a balloon control ring. During the process, the stationary pot with its supply package must be prevented from rotating.

The use of magnets and electromagnetism in spindle assemblies is not unknown. Muzila, in US 4,594,844, describes an improved stop

spindle that has a ferromagnetic clutch that is applied against a brake lining by an electromagnet. The brake lining is non-magnetic and is positioned between the poles of a magnet. US 3,645,083 is also for an electromagnetic braking system for a spindle assembly. Flowers et al, in US 3,731 ,479, discloses a bobbin seater having a magnet to holds the bobbin to the spindle.

SUMMARY OF THE INVENTION

According to its major aspects and broadly stated, the present invention is a method and apparatus for stabilizing the pot of a spindle assembly by creating a shaped magnetic field between the pot and the stationary balloon control ring. The shaped magnetic field establishes a preferred position, a starting position, for the pot with respect to the control ring so that the pot resists movement from that position regardless of rotation of the spindle. In a preferred embodiment, the magnetic force field is a repulsive one between pot and ring but the repulsive forces are shaped to increase when the pot moves from the starting position rather than uniform. Such a shaped magnetic field is established for example by one set of spaced apart magnets on an inner ring attached to the pot and another set on an outer ring attached to the balloon control ring. The inner ring is attached to the pot radially inwardly of and spaced apart from the balloon control ring; the outer ring, which is in spaced relation to the inner ring, is attached to the balloon control ring with the ballooning thread between it and the inner ring.

The cooperation of the magnets of the inner and outer rings is an important feature of the present invention. The magnets of the inner and outer rings are interleaved azimuthally; that is, by "interleaving" is meant that an imaginary radius running from the axis of rotation of the pot outwardly and being rotated azimuthally about that axis will pass through a first magnet of the outer ring, then a magnet of the inner ring, then a second magnet of the outer ring, and so forth alternating from passing through a magnet of the outer ring to one from the inner ring. Thus, the repulsive forces between the inner and outer magnets increase if the inner ring rotates slightly in either direction with respect to the outer ring because the magnets must move closer to each other when aligned rather than interleaved. Because the outer ring is rigidly attached to a stationary balloon control ring, the inner ring - and the pot it is attached to ~ resists rotation. Furthermore, by repelling each other magnetically, the balloon control ring and pot maintain a constant separation and restore themselves when vibrations change the separation distance.

Locating the apparatus for spindle assembly stabilization is another important feature of the present invention. By locating the stabilization apparatus on the sides of the pot and the balloon control ring, backfitting the present invention to existing spindle assemblies is easier than repairing oblique spindle assemblies. Furthermore, only the bearing stabilization will be eliminated when worn or broken if the present apparatus is backfitted; there is no need for replacement of the entire spindle.

Other features and advantages of the present invention will be apparent to those skilled in the art from a careful reading of the

Detailed Description of a Preferred Embodiment presented below and accompanied by the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

Fig. 1 is a perspective view of the exterior of a spindle assembly according to the prior art;

Fig. 2 is a perspective view of a cross section of the spindle assembly shown in Fig. 1 and taken along lines 2-2;

Fig. 3 is a perspective view of the top portion of a spindle assembly according to a preferred embodiment of the present invention; and

Fig. 4 is a cross sectional view of the pot of the spindle assembly shown in Fig. 3 taken along lines 4-4.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now to Figs. 1 and 2, there is illustrated one type of prior art spindle assembly 10, called a "cabler", of a type manufactured and in use in the textile industry. Spindle assembly 10 comprises a spindle 12 and a pot 14. Spindle 12 is designed to rotate and pot 14, which rides freely on spindle 12, is designed to remain stationary. Spindle 12 and balloon control ring 16 are affixed to a frame (not shown). Pot 14 is a simply a hollow container for holding a supply 16 of thread. Pot 14 rides on spindle 12 freely; that is, pot 14 is free to turn and can turn independently of spindle 12.

Therefore, pot 14 can rotate in the same direction as the direction of rotation of spindle 12 and at a different speeds.

To prevent rotation of pot 14, spindle 12 has evolved into a rather complicated piece of machinery. It contains a top bearing housing 20 with a top bearing 22 to enable pot 14 to connect pot 14 to spindle 12 on a spindle axle 24. Preventing rotation are an upper oblique bearing assembly 26 and a lower oblique bearing assembly 28 within spindle 12. These bearing assemblies 26, 28, prevent pot 14 from rotating when spindle 12 rotates in the prior art spindle assembly 10.

Between upper and lower oblique bearing assemblies 26, 28, is a spindle cylinder 32 having holes 34 through which threads 36 from supply 16 can be drawn to the exterior of spindle 12. Thread may also be drawn from an exterior supply and brought into spindle 12 through a hole 38 in spindle axle 24 at the bottom of spindle 12.

Below oblique bearing assemblies 26, 28 is a stationary spindle housing 40 that partially surrounds a whorl housing 44, the two components being rotatable with respect to each other via a spindle bearing 46. Whorl housing 44 contains a whorl bearing 48, a clutch cone assembly 50, a spring 54 and cam sleeve 56 that in combination control the rotation of spindle 12.

Thread 36 from collar 32 is drawn out of spindle 12 and around the outside of pot 14, but inside of a balloon control ring 16, where it will be twisted around a second thread 58 being drawn directly from pot 14. Because spindle 12 is spinning, thread 36 is also spinning and, as a result of centrifugal forces, flares radially outwardly. Balloon control ring 16 prevents excessive flare or ballooning.

Oblique bearing assemblies 26, 28 eventually become worn or in need of repair. Because they are complex and located inside spindle 12, they are expensive and time-consuming to service and replace. The present invention obviates the need for these bearing assemblies and provides an easy method and apparatus for stabilizing pot 14 with respect to spindle 12.

Figs. 3 and 4 illustrate the top portion of a spindle assembly 60 according to the present invention. Shown is a pot 64 on a portion of a spindle 66. Encircling pot 64 is a balloon control ring 70, as before but now balloon control ring 70 position is held rigidly in place by a clamp 72 to a stationary frame 74. Attached to balloon control ring 70 is an outer ring 78 having a plurality of spaced apart magnets.

Attached around pot 64 is an inner ring 82 that also has a plurality of spaced apart magnets 84. Inner ring 82 is oriented so that magnets 84 are on the inside of inner ring 82 rather than the outside of inner ring 82 so as to leave the smooth surface of inner ring 82 for a ballooning thread 86. Magnets 80 of outer ring 78 are placed to the outside of outer ring 78.

The magnets 80, 84 of outer and inner rings 78, 82 are preferably oriented so that the like-poles are directed toward each other so that the magnets 80, 84 of outer ring 78 and inner ring 84 repel each other. Furthermore, using small magnets that are spaced apart on each ring creates a shaped magnetic field. In particular, the magnets of the two rings are interleaved azimuthally. If a radius is imagined running from the axis of rotation of pot radially outwardly and moved in the azimuthal direction, it will be seen to pass through a magnet from outer ring, then a magnet from inner ring, then an outer

ring magnet, and so on, alternating between inner ring magnets 84 and outer ring magnets 80. Pot 64 is positioned so that inner ring magnets 84 are interleaved as described. Then, although the magnets still repel each other, rotating pot 64 slightly from this starting position - and thereby rotating inner ring 82 — results in opposing magnets being moved closer and the repulsive forces increasing. Thus, magnets 80, 84 of outer and inner rings 78, 82 enable pot 64 to resist rotation. It is not necessary that outer and inner rings 78, 82 have magnets 80, 84 about their entire circumferences. Rather, a smaller number of magnets, say 6 and 8, respectively, are sufficient, preferably deployed in equal numbers on diametrically opposing sides of outer and inner rings 78, 82. Magnets are preferably small but strong, such as those made of ceramics.

Alternatively, an inner and outer band of polymer doped to varying degrees can create the appropriately shaped magnetic field as supplied by pluralities of spaced apart discrete magnets. Also, attractive forces can create a shaped magnetic field where the most attractive forces prevent or resist movement to lesser attractive forces. In use, a new spindle assembly 60 can simply be manufactured with outer and inner rings 80, 84 in place. However, an existing spindle assembly 60 can easily be backfitted by slipping inner ring 82 over pot 64 but inside balloon control ring 70 and slipping outer ring 78 over the outside of balloon control ring 78, tightening both, perhaps with a bolt clamp 88 as shown in Figs. 3 and 4, and by removing the oblique bearings and bearing housings of spindle 66.

It will be apparent to those skilled in the art that many changes and substitutions can be made to the preferred embodiment herein

described without departing from the spirit and scope of the present invention as defined by the appended claims.