[0001] The present invention relates to a device for promoting the expulsion of the vegetable
impurities in a wool card comprising at least two Morel cylinders with each of which
there cooperates at least one burr-beater.
[0002] The main characteristic of the invention lies in the fact that a first transfer roll
and a second transfer roll, independent of one another and situated at different heights,
are used to transfer the wool between two successive Morel cylinders, the upper transfer
roll being formed and operated in a manner such as to remove from the first Morel
cylinder outer portions of the tufts of wool having a thickness equal to approximately
half of the total thickness of the tufts and to deposit these outer portions on the
second Morel cylinder, and the lower transfer roll being formed and operated in a
manner such as to remove the remaining portions of the tufts of wool and to deposit
these inner portions on the second Morel cylinder at a point which, at any moment,
is angularly spaced from the point at which the aforementioned outer portions of the
tufts of wool are deposited.
[0003] The above-mentioned characteristic achieves the following advantages in comparison
with the prior art, according to which only one transfer roll was used between two
Morel cylinders.
A) The expulsion, by the burr-beater or burr-beaters which cooperate with the second
Morel cylinder, of the vegetable impurities which, on the first Morel cylinder, were
incorporated in the tufts of wool approximately half way through their thickness is
facilitated.
The splitting of these tufts into two portions in fact brings these impurities to
the surface, facilitating their expulsion by the burr-beater or burr-beaters cooperating
with the second Morel cylinder.
B) A more homogenous distribution of the fibres on the second Morel cylinder is achieved,
not only facilitating the removal of the impurities by the burr-beater or burr-beaters
cooperating with this cylinder but also improving the carding effect performed by
the carding unit disposed downstream of the Morel cylinders.
[0004] Further characteristics and advantages of the present invention will become clear
from the following description, given with reference to the appended drawings, provided
purely by way of example, in which:
Figure 1 is a schematic side view of a device according to the invention for promoting
the expulsion of the vegetable impurities from a wool card according to the invention,
and
Figure 2 is a schematic representation of a tuft of wool showing, in longitudinal
section, the distribution of the impurities within the thickness of the tuft.
[0005] In Figure 1, a device for promoting the expulsion of the vegetable impurities from
a wool card comprises a first Morel cylinder 1 with which at least one burr-beater
2 cooperates, and a second Morel cylinder 3 with which at least one burr-beater 4
cooperates.
[0006] Both of the Morel cylinders 1, 3 rotate in the same direction which, in the embodiment
of Figure 1, is clockwise, as indicted by the arrows.
[0007] Two independent transfer rolls 5, 6, situated at different heights, are interposed
between the first Morel cylinder 1 and the second Morel cylinder 3.
[0008] The upper transfer roll 5 rotates anticlockwise with a peripheral velocity greater
than that of the cylinder 1 and preferably has a resilient covering, more precisely,
a covering constituted by needles bent like elbows in the direction of rotation of
the roll 5.
[0009] The selected distance between the periphery of the covering of the transfer roll
5 and the periphery of the Morel cylinder 1 is such that the roll 5 removes from the
covering of the cylinder 1 only the outer portions, indicted 7a in Figure 2, of the
tufts of wool 7 held in the covering and deposits them on the second Morel cylinder
3 which rotates clockwise with a peripheral velocity greater than that of the roll
5.
[0010] The portion of wool, indicated 7b in Figure 2, which remains on the cylinder 1 is
removed by the lower transfer roll 6 which rotates anticlockwise with a peripheral
velocity greater than that of the first Morel cylinder 1 and preferably has a brush-like
covering, that is, a covering constituted by natural and/or synthetic radial bristles.
The portion of wool which is removed by the lower transfer roll 6 is deposited on
the surface of the second Morel cylinder 3 which rotates with a peripheral velocity
greater than that of the transfer roll 6. This deposition takes place, at any moment,
at a point on the second Morel cylinder 3 which is angularly spaced from the point
on which the outer portion 7a is deposited.
[0011] The fact that the tufts of wool present on the first Morel cylinder 1 are split into
two portions enables the vegetable impurities which, as indicated 8 in Figure 2, are
situated in the inner, central portion of each tuft of wool 7 (that is, in the vicinity
of the median plane indicated M in Figure 2) to be brought to the surface, so that
they can easily be removed by the burr-beater 4 and by any further burr-beaters cooperating
with the second Morel cylinder 3.
[0012] This splitting-up of the tufts of wool 7 also achieves a more homogeneous distribution
of the fibres on the second Morel cylinder 3, which improves the carding effect performed
by the carding unit (not shown) situated downstream of the Morel cylinders 1 and 3.
[0013] The fact that, of the two transfer rolls 5 and 6, one has a resilient covering and
the other has a brush-like covering, enables the advantages of both types of covering
to be utilized.
[0014] Rolls covered with resilient coverings are in fact particularly suitable for engaging
and removing hard parts such as pieces, whereas brush-like rolls are particularly
effective in keeping the Morel cylinders clean.
[0015] According to a variant usable in particular for wool having a very high percentage
of impurities, both of the transfer rolls interposed between two successive Morel
cylinders have brush-like coverings.
1. A device for promoting the expulsion of the vegetable impurities in a wool card comprising
at least two Morel cylinders (1, 3) with each of which at least one burr-beater (2,
4) cooperates, characterized in that a first transfer roll (5) and a second transfer
roll (6), independent of one another and situated at different heights, are used to
transfer wool between two successive Morel cylinders (1, 3), the upper transfer roll
(5) being formed and operated in a manner such as to remove from the first Morel cylinder
(1) outer portions (7a) of the tufts of wool (7) having a thickness equal to approximately
half of the thickness of the tufts (7) and to deposit these outer portions (7a) on
the second Morel cylinder (3), and the lower transfer roll (6) being formed in a manner
such as to remove the remaining portions (7b) of the tufts of wool (7) and to deposit
these remaining portions (7b) on the second Morel cylinder (3) at a point which, at
any moment, is angularly spaced from the point at which the aforementioned outer portions
(7a) are deposited.
2. A device according to Claim 1, characterized in that both of the transfer rolls (5,
6) rotate in the opposite direction to the direction of rotation of the two Morel
cylinders (1, 3), each transfer roll (5, 6) having a peripheral velocity which is
greater than that of the first Morel cylinder (1) but less than that of the second
Morel cylinder (3).
3. A device according to Claims 1 and 2, characterized in that one of the two transfer
rolls (5) has a resilient covering with needles bent like elbows and inclined in its
own direction of rotation, and the other transfer roll (6) has a brush-like covering
with natural and/or synthetic radial bristles.
4. A device according to Claims 1 and 2, characterized in that both of the transfer rolls
have brush-like coverings with natural and/or synthetic bristles.