[0001] The present invention relates to a device for expelling the vegetable impurities
in a wool card of the type comprising at least one Morel cylinder with which at least
one pair of burr-beaters cooperates.
[0002] It is known from patent application FR-A-2,232,626 to use, on a Morel cylinder, two
burr-beaters between which an inverted carding unit constituted by a worker and by
a stripper is interposed.
[0003] The function of this inverted carding unit is to perform a carding operation on the
wool transported by the Morel cylinder and to turn the tufts of wool over.
[0004] However, this solution is not satisfactory, in the first place, because it turns
the fibres over only partially. Moreover, a large amount of turbulence is produced
in the region between the points of contact of the worker with the Morel cylinder,
of the worker with the stripper, and of the stripper with the Morel cylinder, owing
to the draughts caused by the rotation of said cylinders so that, in the tufts of
fibres which emerge from this carding unit as a result of the action of the stripper,
not all of the fibres are correctly oriented parallel to the direction of advance
and the fibres may also have agglomerations of wool.
[0005] As a result of the action of the subsequent burr-beater, this may lead to breakage
of the incorrectly oriented fibres and to expulsion or damage of any agglomerations
of wool.
[0006] It is known from patent application EP-A-0 768 397 to use, on a Morel cylinder, two
burr-beaters, between which is interposed a pair of rolls of which the first is a
roll having a brush-like covering and rotating at a speed faster than that of the
Morel cylinder and the second is a turning roll having a rigid covering with triangular
points oriented in its own direction of rotation, rotating at a speed between that
of the brush-like roll and that of the Morel cylinder, and discharging the brush-like
cylinder completely by densification.
[0007] The solution which forms the subject of this application achieves - in comparison
with the solution known from FR-A-2,232,626 - complete rather than partial turning-over
of the fibres. However, this solution is also unable to output all of the fibres with
the correct parallel orientation since the turning roll cannot render parallel those
fibres which undergo a random orientation as a result of the above-mentioned turbulence.
[0008] In order to prevent the above-mentioned disadvantages of the prior art, the subject
of the present invention is a device for expelling the vegetable impurities in a card
of the type specified above having the characteristics which form the subject of Claim
1.
[0009] The invention will now be described with reference to the appended drawing which
shows an embodiment of the invention by way of example.
[0010] In the drawing, a Morel cylinder, which rotates clockwise and forms part of a device
for expelling vegetable impurities in a wool card, is indicated 1.
[0011] Cooperating with the Morel cylinder 1 are two burr-beaters 2, 3 which have radial
blades and rotate clockwise, and each of which picks up vegetable impurities from
the wads of wool transported by the Morel cylinder 1 and discharges them into a respective
collector 2a, 3a.
[0012] A pair of rolls 4, 5, both rotating anticlockwise, is interposed between the two
burr-beaters 2, 3. The first roll 4 is a working roll having a rigid covering with
triangular points inclined in its own direction of rotation, rotating with a peripheral
velocity slower than that of the Morel cylinder 1 and picking up the flow of fibres
therefrom.
[0013] The second roll 5 is a roll having a brush-like covering constituted by natural or
synthetic bristles and rotating with a peripheral velocity faster than that of the
working roll 4 but slower than that of the Morel cylinder 1. Owing to the high density
of its bristles, the brush-like roll 5 brings about an oriented turning-over of the
fibres which is not adversely affected by the turbulence arising in the region between
the contact points of the cylinder 1 and the rolls 4 and 5 so that, at the output
of the brush-like roll 5, the wool fibres are arranged on the Morel cylinder 1 correctly,
that is, parallel with one another.
1. A device for expelling the vegetable impurities in a wool card, of the type comprising
at least one Morel cylinder (1) with which at least one pair of burr-beaters (2, 3)
cooperates, characterized in that, between each pair of burr-beaters (2, 3) cooperating
with a Morel cylinder (1) there is interposed a pair of rolls (4, 5) of which the
first is a working roll (4) which has a rigid covering with triangular points inclined
in its own direction rotation and which rotates at a speed slower than that of the
Morel cylinder (1), picking up the flow of fibres therefrom, and the second is a roll
which has a brush-like covering (5) and rotates at a speed faster than that of the
working roll (4) but slower than that of the Morel cylinder (1), turning the fibres
over in an orderly manner and arranging them parallel with one another on the Morel
cylinder (1).
