[0001] This invention refers to a cop for winding up yarn and is directed in particular
to a rigid cop in plastic material for dyeing, scouring and like yarn processing operations,
which cop is provided with suitable means to prevent the yarn from becoming excessively
crushed or spoiled during copping.
[0002] When yarns are to be prepared for dyeing, scouring and similar processing operations,
especially delicate yarns such as silk, low count polyester yarns produced by continuous
spinning methods, and the like, the yarn must be wound onto a cop or reel before proceeding
to the dyeing or processing stage.
[0003] Some types of cop currently in use consist of a perforated cylindrical body having
a constant outer diameter, that is used directly on the twisting machine before the
processing operation. The copping operation, that is to say winding of the first layer
of yarn turns onto the cylindrical surface of the cop, is a delicate operation as
far as low count or thin yarns are concerned, in that the drive roller exerts a certain
pressure on the first turns of yarn, crushing them against the rigid surface of the
cop and against the edges of the holes or perforations, thus damaging the yarn. When
silk or yarns of a certain value are involved, even damage to a few turns of yarn
at the start of the copping operation results in appreciable losses through waste.
[0004] An object of this model is to provide a cop for winding delicate yarns, particularly
for use in dyeing and similar processing operations, capable of overcoming the aforementioned
problems in that it prevents the yarn at the beginning of the copping operation from
being crushed with an excessive pressure against the cop surface and damaged against
the edges of the cop apertures or on the very scratched or rough surfaces that are
normally found on the usual cops.
[0005] The above has been achieved with a cop according to the present invention, comprising
a hollow cylindrical body having an outer surface on which the yarn is wound in evenly
distributed superimposed layers by the action of a pressure or drive roller, said
cop being characterized by the fact that at each end of the yarn winding surface the
cylindrical body of the cop is provided with an annular surface means for contacting
the pressure roller at the start of copping, said annular surface means protruding
radially with respect to the yarn winding surface for a height substantially equal
to or slightly differing from the diameter of the yarn, corresponding to the thickness
of the first layer of yarn to be wound onto the cop. In this manner, the two outer
bands on which the drive roller initially rests ensure that the first turns of yarn
are not crushed excessively against the cop and thus are not damaged against the edges
of any apertures or scratched or rough surfaces there might be on the cop surface.
[0006] The cop according to the present invention will now be better illustrated with reference
to the accompanying drawing in which:
Fig. 1 is a partially sectioned view of an embodiment of the cop according to the
invention;
Fig. 2 is an enlarged detail of figure 1.
[0007] As shown in the figures, the cop 10, made of molded plastic material, substantially
comprises a cylindrical hollow body 11 having an outer yarn winding surface 12, provided,
in the case illustrated, with a plurality of trapezoidal through apertures which allow
the cop with the yarn wound on it to be immersed in a processing bath, for example
in dyeing or like operations.
[0008] During the initial yarn winding or copping stage, the first layer of turns might
be damaged by an excessive pressure exerted by the drive roller 16 of the winding
device which pushes the yarn against the winding surface 12, especially against the
edges of the apertures 13 in the cop body.
[0009] Therefore, in order to reduce pressure on the turns of the first layer of yarn, during
the initial stage of each winding operation, according to the present invention, at
each end of the yarn winding surface 12, the body 11 has been provided with a radially
protruding annular surface 14 to contact the pressure roller 16, said annular surface
14 extending axially for a few mm, for example 10 or 12 mm, and protruding radially
from the cop body 11 to a height that is substantially equal to or slightly differs
from the yarn diameter, that is the thickness of the first wound layer of yarn. As
a guideline, for very thin or very low-count yarns, the radial protrusion of the annular
surfaces 14 with respect to the cylindrical outer surface 12 of the cop body might
be a few tenths of a millimeter, for example being 2/10 and 10/10 of a millimeter
approximately. Figure 2 of the attached drawing shows an enlarged view of the particular
arrangement taken on by the first layer of yarn 15 during the copping stage, when
it is disposed in the empty space left between the cop surface 12 and the peripheral
surface of the drive roller 16 the ends of which initially rest on the two annular
surfaces 14 which receive the maximum pressure.
[0010] From what has been said and illustrated in the attached drawings, it will be clear
that what is provided is a cop for winding yarn or thread, especially for dyeing or
similar processes, in which, by adopting special raised annular surfaces at both ends
of the cop, namely on its yarn winding surface, it is possible to reduce pressure
on the yarn and avoid damaging it during the initial copping stage.
1. - A cop (10) for winding up yarns (15) especially for dyeing, scouring or like
processing operations, comprising a cylindrical hollow body (11) having a yarn winding
surface (12) on which the yarn is wound by the action of a drive roller (16), characterized
in that at each end of the yarn winding surface (12) the cylindrical body (11) of
the cop is provided with a radially protruding annular surface means (14) defining
a resting a surface for the pressure roller (16) at the beginning of the yarn winding.
2. - A cop according to claim 1, characterized in that said annular resting surface
(14) protrudes for a height between 2 and 10 tenths of a millimeter.
3. - A cop according to claim 1, particularly for yarn dyeing and similar processing
operations, characterized in that the cylindrical body (11) of the cop (10) is provided
with a plurality of apertures (13).
