US2621373A - Drafting system for textile fibers - Google Patents

Description

Dec. 16, 1952 E. R. GOSHAWK 2,621,373

DRAFTING SYSTEM FOR TEXTILE FIBERS Filed Aug. 29, 1949 Attorney;

Patented Dec. 16, 1952 DRAFTING SYSTEM FOR TEXTILE FIBERS Eric R. Goshawk, Rock Bank, Bollington, England, 'assignor to Fine Spinners & Doublers Limited, Manchester, England Application August 29, 1949, Serial No. 112,917

, In Great Britain September 4, 1948 2 Claims.

This invention relates to improvements in drafting systems for textile fibres and particularly but not exclusively to high drafting systems It is well-known in roller drafting devices that an eccentric top roller or bottom roller causes periodic thick and thin places in the drafted slivers, rovings or yarns. This is usually due to the movement of the roller-nip of one roller pair in relation to the roller-nip of the preceding roller pair and since, in a drafting sequence, the highest draft occurs in the front zone, it is on the fron roller pair that eccentricity should be eliminated as far as possible. Although perfect roller-nip control is desirable in all drafting heads it becomes more essential to good work in ring spinning frames using high draft systems. The top rollers of a ring spinning frame are assembled in pairs and are easily removable from the frame. Should any fault develop in a bottom-roller line, however, it is impossible in most cases to correct it without removal from the frame and consequent loss of production.

The object of the present invention is the automatic correction of any movement of the bottom-roller centre due to rotation, by the creation of an equal and opposite movement of the centre of the top cushioned roller in such a manner that the line of contact between the two remains substantially unchanged in position, such correction being hereinafter referred to as nip stabilization.

The invention consists in means for obtaining nip stabilization between two lines of drafting rollers wherein any movement of the front bottom roller axis during rotation creates an opposite movement of the axis of rotation of the top roller so that the nip of the two rollers remains in the same plane as that in which their axes were originally located.

The invention is illustrated in and will be described with reference to the accompanying drawings, in which:

Fig. 1 is a geometrical diagram illustrating the principle of the invention,

Fig. 2 is an end elevation of the top and bottom front rollers of a ring spinning frame, the position of the top roller being controlled from the bottom roller according to the invention,

Fig. 3 is a plan in half section on line :c-y of Fig. 2,

Fig. 4 is a front elevation of Fig. 2, and

Figs. 5 and 6 are detail perspective views of the parts of the device controlling the top roller.

The principle of the device for nip stabilization is illustrated geometrically in Fig. l where 2 B and T represent the bottom and top front line drafting rollers of a ring spinning frame. The rollers are respectively of radii r and r with centres C and C vertically aligned.

Suppose the centre of B moves to the point 7 C 1 and that at the same time the centre of T moves to the point C 2 this point being such that the line C 1 C 2 is out by the line C C in the ratio r to r then this intersection will be the new point of roller contact and as this point of roller contact is still on the vertical line C C its relation tothe roller-nip of a second line of rollers will remain unchanged: since the movement of the roller centres is at most only a few thousandths of an inch the slight vertical change in "the nip position as shown in Fig. 1 is of a secondary order and of no practical significance.

In the arrangement shown in Figs. 2 to 5 for carrying the invention into practical effect the cap-bar neb is formed in two parts N and N separated a short distance apart to permit of motion of the front member W relative to the rear member N The rear member N carries the web w which forms a recess between the member N and the member N in which the spindle F of the roller T is journalled the member N being rigidly secured to a stiff cap bar b.

A bracket B which extends forwardly over the front member N is secured to or formed integrally with the rear member N The front portion of the bracket B extends downwardly and its inner face is parallel to the plane in which the axes of the two rollers T and B are located.

A rocker V is secured to or formed integrally with the front member N of the neb. In the face of the rocker V two shallow circular recesses U are formed and two similar recesses are formed on the inner face of the bracket B, these recesses serve to retain two compression springs 1!. which force a recess 1) in the rocker V against a pin 1) which passes through a hole in the end of a short rod J. This rod is threaded at the other end to receive a knurled adjusting nut n and passes through holes b 0 respectively in the bracket B and the rocker V allowing ample clearance for slight oscillation of the latter about the pin p.

The bracket B is set so that the rocker V presses against the land b of the bottom fluted roller 13 and the nut 11. adjusted to bring the face of the member N into correct position relative to the member N The top roller weighting must be such as to press the roller spindle F forward against the front member as shown in Fig. 3.

When the roller B is rotating, any eccentric motion of the roller land b against the rocker V will cause the rocker to rock about the pin p with the result that the face of the member N will be moved in the opposite direction and this movement being imparted to the top roller spindle F, thereby maintaining automatically the desired nip stabilization.

It will be appreciated that the device as described can be applied only at roller lands situated between roller stands and is not applicable at the roller neck where, in any event, it should be unnecessary.

I claim:

1. In a drafting system for textile fibres, the combination of a top roller having a spindle and a cooperating bottom roller having a land thereon, a cap bar, a cap bar neb for the spindle of the top roller formed in two parts, a rear part affixed to the cap bar and a front part movable in relation to the rear part, said rear and front parts being spaced apart to receive the spindle of the top roller between them, and an extension of the front part mounted between its ends to rock in a plane transverse to the axes of the top and bottom rollers and carrying said front part at one end and which is engaged at its other end by the land on the bottom roller, and means acting on said extension to press said front part on one end thereof against the spindle of the top roller and to press the other end of said extension against the land on the bottom roller, whereby any movement of the axis of the bottom roller is transmit:- ted by said extension and front part to the top roller in the opposite direction so that the nip of the two rollers remains in the same plane as that in which their axes were originally located.

2. In a drafting system for textile fibres, the combination of a top roller having a spindle and a bottom roller having a land thereon, a cap bar, a cap bar neb for the spindle of the top roller formed in two parts, a rear part aflixed to the cap bar and a front part movable in relation to the rear part, a bracket carried by the rear part and extending over the front part, a rocker plate atfixed to the front part and located behind the bracket, a fulcrum carried by the said bracket about which the rocker plate can rock, springs arranged between the bracket and the rocker plate to press the front part of the cap bar neb against the spindle of the top roller and the lower part of the rocker plate against the land on the bottom roller whereby any movement of the axis of rotation of the bottom roller creates an opposite movement of the axis of rotation of the top roller so that the nip of the two rollers remains in the same plane as that in which their axes were originally located.

ERIC R. GOSHAWK.

No references cited.

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