GB2210388A - Friction spinning - Google Patents

Abstract

A perforated friction spinning roller 1 has its bearings 10 and 18 engaging on the exterior of respective projecting portions 7a, 17 of the rotatable foraminous sleeve 2 which defines a seating for the inner race of the bearing. The rotatable foraminous outer sleeve 2 surrounds an inner suction insert 3 comprising a fixed intermediate sleeve 3 and an inner sleeve 4 which is rotated during the piecing process. Suction is applied via a duct 13 to the insert 3. The arrangement is such that there is no suction leakage through the bearings and thus no fibres etc are drawn into the bearings. <IMAGE>

Description

FRICTION SPINNING APPARATUS The present invention relates to a friction spinning apparatus, and in particular one using at least one perforated roller the interior of which is subject to suction to attract the fibres being spun onto the surface of that roller to cause them to be rolled up by frictional contact between that roller and another adjacent roller of the same or different form.

A friction spinning apparatus of the general type with which the present invention is concerned is disclosed in GB-A-2042599. There, a first roller has a perforated exterior through which the internally applied suction aspirates air to hold fibres on the surface of that roller, the other roller having an imperforate surface which cooperates with the perforating surface to define a spinning gap in which the fibres become rolled up to form yarn.

Other similar forms of friction spinning apparatus use two such perforated rollers.

The present invention is concerned with the mounting of the perforated sleeve of such a perforated roller.

In accordance with the present invention, we provide a per forated spinning roller for a friction spinning unit, comprising:- a rotatable perforated sleeve; a stationary suction insert therewithin to apply suction at localised regions of the periphery of the perforated sleeve: and closed ends to the sleeve; wherein each of said closed ends includes an axially outwardly extending portion having a cylindrical exterior for mounting the perforated spinning roller in a machine frame, and a bearing having an inner race adapted to be seated on said cylindrical surface at the respective ends of the perforated spinning roller for rotatably supporting the perforated spinning roller for rotation relative to its suction insert, the arrangement being such that the suction applied to the interior of the perforated spinning roller is communicated thereto by way of at least one of the ends of said perforated spinning roller, through the respective axially outwardly projecting end portion thereof along a suction duct coaxially within the said end portion whereby, in use, there is substantially no suction leakage into the interior of the friction spinning roller through said bearings.

Preferably at each end of the perforated roller there is a gas-tight fit between a tubular end of the perforated roller and an internal stationary member. At one end of the rotatable perforated sleeve the stationary member may be a suction duct through which suction is applied to the interior of the perforated roller, and at the other end of the rotatable perforated sleeve the stationary member may be a spindle for controlling the position of an internal stationary sleeve defining a suction slot which localizes the effect of the suction applied to the interior of the rotatable perforated sleeve.

Although it is envisaged that a gas-tight fit can be obtained between the stationary internal member and the rotating end of the perforated sleeve, a resilient sealing ring or other member may, if desired, be provided between the tubular end of the rotatable perforated sleeve and the stationary internal member.

The advantage of this particular form of perforated roller is that suction is applied through at least one end of the roller into the interior of the outer rotatable perforated sleeve, but without that suction entraining an airflow through the gap between the inner and outer races of the hearing at either end of the perforated sleeve. There is thus no tendency for fibres to be aspirated through the roller bearing or ball bearing at either end of the rotatable perforated sleeve, as nor is there a tendency for an airflow through that bearing to dry up the luhricating grease of the bearing, causing long-term problems during operation of the friction spinning apparatus.

Advantageously one end of the rotatable perforated sleeve is closed by a blanking cap having the said tubular end portion formed in it, the blanking cap being disposed entirely within the cylindrical interior of the rotatable perforated sleeve.

More advantageously, at the other end of the perforated sleeve the blanking cap may include an external skirt which sealingly fits over the external diameter of the perforated sleeve, and on the side of the blanking member opposite to that where the skirt is formed there is the above mentioned tubular portion.

In order that the present invention may more readily understood the following description is given, merely by way of example, with reference to the accompanying drawing in which the sole Figure is a longitudinal section of the perforated friction spinning roller in accordance with the present invention.

The friction spinning roller illustrated in the drawing is generally designated 1 and includes a rotatable perforated sleeve portion 2 through which air is aspirated in a radially inward direction when suction is applied to the interior of the roller.

In order to confine the application of suction to a precise location around the periphery of the rotatable perforated sleeve 2, for example normally in a rectilinear slot extending substantially parallel to the generatrix of the sleeve 2, an intermediate sleeve 3 is positioned within the rotatable perforated sleeve 2 and closely spaced from it, while defining the slot.

A further inner sleeve 4 is positioned internally of the intermediate sleeve 3 and is rotatable during the yarn piecing process in order to change the distribution of suction along the said rectilinear longitudinal slot shown schematically in the drawing at 5. It will of course be appreciated that the position of the slot 5 relative to the line of closest approach between the perforated roller 1 and an adjacent roller (not shown) which may or may not be similarly perforated, is critical to the operation of the friction spinning machine so that the position shown for that slot in the drawing is merely schematic in order to illustrate the general configuration of. the slot without in any way limiting its position.

The inner sleeve 4 is formed with a parallelogram-shaped slot which is used, during the piecing process, to alter the suction distribution as disclosed in our EP-A-0052412.

At the right-hand end of the roller 1, the rotatable perforated outer sleeve has an imperforate end portion 6 which snugly surrounds a blanking plug portion 7 having a rightwardly extending tubular portion 7a serving to mount the right-hand end of the rotatable perforated sleeve 2 in the machine frame 8.

Coaxially within the tubular portion 7a, and closely spaced therewithin, is a tubular portion 3a of the intermediate sleeve 3, serving to mount the right-hand end of the intermediate sleeve 3a.

Coaxially within the tubular portion 3a, and again mounted with respect thereto in a substantially gas-tight relationship while allowing relative rotation between them, is an internal shaft portion 4a integrally formed with the inner sleeve 4. The shaft portion 4a can be rotated from outside the perforated roller 1, during the piecing process, in order to change the position of the parallelogram-shaped slot therein to alter the suction distribution along the rectilinear suction slot 5.

The shaft portion 4a thus provides a mounting on which the tubular portion 3a of the intermediate sleeve 3 sits, for the purposes of mounting the right-hand end of the intermediate sleeve 3.

The frame 8 has a recess 9 able to receive the hall bearing assembly 10 which rotatably mounts the right-hand end of the perforated roller 1. It is important to note that the ball bearing 10 is on the exterior of the tubular portion 7a and is therefore not likely to be influenced by the suction which is applied to the interior of the inner sleeve 4 but may to some extent spill axially along the annular clearance between the inner sleeve 4 and the intermediate sleeve 3, and similarly axially along the annular clearance between the intermediate sleeve 3 and the perforated sleeve 2.

The ball bearing 10 is held in place by a hardened steel end cap 11 force-fitted into the recess 9.

At the left-hand end of the perforated friction spinning roller 1, the interior of the intermediate sleeve 3 is mounted on a support plug 12 which is itself a tight fit on the exterior of a suction duct 13 connected to a main suction conduit of the multi-position friction spinning apparatus of which the illustrated roller forms a substantial part of one spinning unit.

The inner sleeve 4 stops short of the blanking plug 12 as there is no need for it to be separately supported at the left-hand end of the friction spinning roller 1.

The left-hand end of the rotatable perforated sleeve 2 has a further imperforate area 14, similar to the imperforate area 6 at the right-hand end, but axially more extensive.

The left-hand end of this imperforate area 14 has fitted snugly thereover a tapering skirt 15 of a blanking plug generally designated 16 and having a stub tubular portion 17 extending leftwardly therefrom with a diameter smaller than that of the skirt 15.

The exterior of the tubular portion 17 has a step against which a ball bearing 18 abuts, the ball bearing 18 being held in place by a clip 19 shown schematically in the main drawing but illustrated in more detail in Detail A of the Figure as comprising a generally cylindrical part 20 having regularly inwardly extending ribs 21 and 22 to confine the outer race of the ball bearing 18, and a securing screw 23 intended to clamp the clip 19 firmly in place in the axial direction along the housing 24 of the friction spinning unit at the left-hand end of the perforated roller 1.

It will of course be appreciated that the tubular stub portion 17 of the blanking cap 16 at the left-hand end of the perforated roller 1 is a clearance fit, although preferably in a substantially gas-tight manner, over the exterior of the suction duct 13. This allows for relatively unhindered rotation of the tubular portion 17, along with the sleeve 2 when the perforated friction spinning roller is being driven for rotation.

Although it is not illustrated in the drawing, the perforated friction spinning roller 1 is driven for rotation by a flat belt drive, normally a flat belt drive engaging on the exterior of one of the two imperforate portions 6 and 14 of the outer sleeve of the roller 1.

It will of course be appreciated that, in use of the friction spinning roller 1, suction is applied to the interior 25 of the inner sleeve 4 by way of the main suction duct 13 and there will of course be some leakage of that suction axially rightwardly and leftwardly between (a) the inner sleeve 4 and the intermediate sleeve 3, and (b) the exterior of the intermediate sleeve 3 and the interior of the perforated portion 2 of the outer sleeve 2.

This suction effect will therefore to some extent draw air rightwardly between the rotating tubular stub portion 17 and the stationary suction duct 13 so that it may be advantageous to incorporate a flexible sealing gland between the tubular portion 17 and the cooperating surface of the suction duct 13. The important feature is that the suction does not aspirate air through the clearance between the outer race and the inner race of the hall bearing 18, and hence there is no attraction of airborne fibre and dust into the greasy bearing, nor is there any tendency for the grease in the bearing to dry out through the aspiration of an airflow constantly thereover.

The application of suction to the interior of the perforated friction spinning roller 25 is thus confined to the space between the two bearings and the bearings are totally external of the friction spinning roller 1.

Claims (7)

C J, A I M S

1. A perforated spinning roller for a friction spinning unit, comprising:- a rotatable perforated sleeve; a stationary suction insert therewithin to apply suction at localised regions of the periphery of the perforated sleeve; and closed ends to the sleeve; wherein each of said closed ends includes an axially outwardly extending portion having a cylindrical exterior for mounting the perforated spinning roller in a machine frame, and a bearing having an inner race adapted to he seated on said cylindrical surface at the respective ends of the perforated spinning roller for rotatably supporting the perforated spinning roller for rotation relative to its suction insert, the arrangement being such that the suction applied to the interior of the perforated spinning roller is communicated thereto hy way of at least one of the ends of said perforated spinning roller, through the respective axially outwardly projecting end portion thereof along a suction duct coaxially within the said end portion whereby, in use, there is substantially no suction leakage into the interior of the friction spinning roller through said bearings.

2. A spinning roller according to claim 1, wherein the perforated sleeve is closed at each end by a respective end cap, the end cap of one end of said spinning roller having a tubular said projecting portion on which the inner race of the associated bearing seats.

3. A spinning roller according to claim 2, wherein at the other end of the friction spinning roller the end cap further has a tubular said projecting portion on which the inner race of the bearing seats.

4. A spinning roller according to claim 2 or claim 3, wherein the suction insert includes a normally stationary intermediate sleeve and an inner sleeve, both coaxially mounted with respect to the rotatable perforated outer sleeve, and wherein the intermediate sleeve also has a tubular end portion which extends coaxially within the tubular projecting portion of the end cap at-that end of the rotatable perforated sleeve, and the respective end of the inner sleeve has a solid axially projecting shaft seated within the tubular end portion of the intermediate sleeve.

5. A spinning roller according to claim 4, wherein at the other end of the friction spinning roller the intermediate sleeve seats on the exterior of a suction duct, and the end cap of the friction spinning roller includes an external flange which sealingly fits over the exterior of the rotatable perforated sleeve.

6. A spinning roller according to any one of the preceding claims, and including means for locating said bearings precisely at one or both ends of the friction spinning roller.

7. A perforated spinning roller substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.