Opening roller for open end spinning machines

A pinned opening roller for an open end spinning machine wherein the pinning pattern around the circumferential surface of the roller is provided by spaced pairs of rows of pins which may extend parallel to the rotational axis of the roller, the spacing between the pairs of rows being greater than the spacing between the rows in each pair and in any pair, the pins in one row being staggered relative to those in the other row. Preferably, for a 71/2" circumference roller approximately 1" wide the pins in each row are spaced 0.1" apart and the rows in a pair are 0.03" apart and there are 28 pairs of rows around the circumference. Preferably, the pins in one row of a pair are each spaced equidistant from their adjacent pins in the other row and the pins in the first row of each pair are helically arranged and those in the second row of each pair also extend helically around the circumference of the roller.

BACKGROUND OF THE INVENTION 
This invention relates to pinned opening rollers or beaters for open end 
spinning machines wherein a sliver or untwisted rope of fibres is 
separated by the opening or combing roller or beater into individual 
fibres, which are assembled into a yarn. Such an opening roller carries an 
array of sharp projections which may either be in the form of saw-toothed 
wire wound helically onto the circumferential surface of the roller or of 
individual pins projecting from the said surface of the roller. 
Conventionally two types of pin pattern have been used for the pinned type 
of roller with the basic difference that in one type the distance from pin 
to pin within a row is approximately equal to the distance between the 
rows (equal relationship) while in the other pattern (unequal 
relationship) a similar number of pins are disposed in each roller, but 
there are fewer rows with more pins in each row, than is the case with the 
equal relationship. 
Both these alternative type of roller can be used, one type being more 
suited to some designs of open end spinning machines and the other for 
other designs of machine. 
In order to provide a sufficiently intensive opening action on the fibres, 
the distance from pin to pin in each row in the case of the opening roller 
with unequal relationship has to be relatively close. This in turn limits 
the diameter of the pin which can be utilised as sufficient roller 
material has to be left for the matrix holding the pins not to be unduly 
weakened. Furthermore, the reduced diameter of the pins means they are 
weaker and also wear more quickly. 
SUMMARY OF THE INVENTION 
From another point of view, as the sliver being combed is firmly held 
between the feed roller and the feed shoe in the spinning unit of the 
machine, adequate drafting space or free space between the pins must be 
allowed as otherwise the opening roller will tend to clog or lap-up. This 
requirement also limits the distance between the centre lines of adjacent 
pins in each row. 
Drafting space is thus a compromise between the number of pin points 
required within a row, and the pin diameter. 
In one example of a known pinning pattern of equal relationship, pins of 
19's gauge (0.042") are set in rows with approximately 0.100" between rows 
and 0.100" between pins within the rows. 
A known example of an unequal relationship uses pins of 24's gauge 
(0.0245") set in rows 0.200" apart with a 0.050" between pins within the 
row. 
Another factor to be considered in designing opening rollers is the pin 
shape. Practical experience has shown that a pin whose point encloses a 
relatively large cone angle is preferably to one which is needlepointed. 
Thus for a given pin projection a relatively large diameter pin has 
textile technological advantages in open end spinning. 
The 0.042" pin in the first example above with a taper length of 0.125" has 
a point cone angle of 19.degree. while the 0.0245" from the second example 
with a similar taper length has a point cone angle of 11.degree.. 
Ideally, therefore, one requires high pin tip density in the rows, with 
pins whose diameter is sufficient to give long life, and yet the density 
of the pins in each row at their base where they are secured in the roller 
matrix must be as low as possible, so as not to weaken the matrix. 
The present invention has been designed to meet these conflicting 
requirements of pin point density and pin diameter with its consequent 
effects on pin point cone angle and pin strength and wearing properties. 
According to the present invention, we provide an opening roller for use in 
open end spinning machines wherein the opening action is provided by an 
array of pins secured in and projecting by a uniform amount from the 
circumferential surface of the roller, wherein the pins are arranged in 
spaced pairs of rows which may be parallel to the rotational axis of the 
roller, the spacing between the pairs being greater than the spacing 
between the rows in any pair of rows, and in any pair, the pins in one row 
being staggered relative to those in the other row. 
Each such double row or pair of rows of pins permits an adequate number of 
pins in each axial group of pins, i.e. each pair of rows, while allowing 
the pin diameter to be sufficiently large to permit a suitable pin cone 
angle. 
Preferably, in any pair of rows the pins in one row are located mid-way 
between the pins in the other row. Thus, the pair of rows of pins gives a 
pin density which is twice that of a single row. 
If desired, the pins can be arranged around the circumference of the roller 
in a plurality of helices, the pin pattern around the circumference being 
repeated four times. 
In a preferred arrangement, the roller has twenty eight pairs of rows of 
pins located around the circumference of the roller, which measures about 
71/2", and 8 or 9 pins are provided in each row, spaced approximately 0.1" 
apart. In this arrangement, the rows of each pair are set about 0.03" 
apart. 
Preferably, the pins are of 19's gauge. 
One embodiment of opening roller in accordance with the invention is now 
described by way of example with reference to the accompanying partly 
schematic drawing which shows a development of the circumferential plane 
of a pinned roller. 
The overall construction of the pinned opening roller is known and 
basically the roller comprises a central hub having a central axial 
aperture therein about the central axis of which the roller rotates at 
high speed, the hub projecting from a central portion of one side wall of 
the roller. This side wall is connected to the opposite side wall by a 
cylindrical pinned portion of the roller, the other side wall being open 
and defined merely by an annular portion connected to the cylindrical 
pinned portion and an end face of the central hub. The rear ends of the 
pins project from the rear face of the cylindrical pinned portion towards 
the hub and the space between the cylindrical portion and the cylindrical 
surface of the hub may be filled with a plastics material totally 
encompassing the rear ends of the pins. The outer surface of the 
cylindrical pinned portion is recessed relative to the periphery of the 
side walls and the pin heads are located in this recessed portion. The 
present invention is concerned with the pinning pattern of the cylindrical 
portion.

Referring to the FIG. 1, the pins are arranged in the cylindrical portion 
20 in pairs of rows 1, 3, 5, etc. The two rows in the pair 1 are indicated 
at 7 and 9 whereas the two rows in the pair 3 are indicated at 11 and 13. 
In each row 7-13 etc. which rows extend parallel to the rotational axis of 
the roller, the pins are equally spaced from each other and in any pair of 
rows 1, 3, 5, etc. the pins in one row are staggered relative to the pins 
in the other row. The spacing between the pairs of rows is greater than 
the spacing between the rows in any pair of rows. 
FIG. 2. systematically illustrates the pinning pattern provided in 
accordance with the present invention defined on the cylindrical portion 
20 of an opening roller 22. The opening roller 22 includes a central hub 
24 having a central axial aperture 26 therein. First and second side walls 
28 are provided (only one of which is shown for clarity in FIG. 2), the 
side walls being connected to one another by the cylindrical portion 20 of 
the roller 22. As also noted above, the structure of the opening roller 
itself is known and it is the pinning pattern provided on the cylindrical 
portion of the roller which is the subject of the present invention. 
In a preferred arrangement the pins in the rows 9 and 13 are located 
mid-way between the pins in the rows 7 and 11 respectively. In an 
alternative construction, the first row of pins in each pair is located on 
a helix and likewise, the second row of pins in each pair is located on a 
further helix. 
In a preferred arrangement, for a roller having a circumference of about 
71/2" and being about 1" wide, the pins in each row are preferably spaced 
apart by 0.1" thus meaning that 8 or 9 pins can be provided in each row 
and the circumferential spacing between the two rows in any pair of rows 
is about 0.03", that is, for example, the distance between the rows 7 and 
9. This means that the approximate spacing between each pair of rows, e.g. 
the distance between the centre line of the row 9 and the centre line of 
row 11 is about 0.238". Furthermore, the pins are arranged in a helical 
pattern around the circumference of the roller. In a preferred arrangement 
there are 28 pairs of rows of pins which means that the pin pattern around 
the circumference of the roller can be repeated four times, there being 7 
pairs of rows of pins in each repeating pattern and each repeating pattern 
has 8 or 9 helical rows of pins in the circumferential direction defined 
by the pins in one axial row between which are 8 or 9 further helical rows 
of pins defined by the pins in the other axial rows of each pair. 
By arranging the pinning pattern in this way, 19's gauge pins (0.042" 
diameter) can be used rather than the smaller 24's gauge pins which would 
otherwise be necessary if the quantity of pins in a pair of rows was used 
in a single row. In this way the matrix material forming the cylindrical 
pinned surface is not weakened when drilled to receive the pins (which are 
of course located in position in known manner). By being able to use the 
larger diameter pins, pins with large cone angles at the point can of 
course be used which has considerable technological advantages in open end 
spinning. 
It will of course be appreciated that many other different pinning 
arrangements in accordance with the present invention are possible 
provided that the pins are set in pairs of rows wherein the rows in a pair 
are closer together than are adjacent pairs of rows. 
It is not essential for the pins to be helically orientated around the 
circumference of the roller and other known arrangements can be used.