[0001] This invention relates to a machine for treating (scouring and/or fulling) fabrics
particularly of vegetable or synthetic fibres in open width, of the type provided
in succession with at least one tank, means for widening the fabric rising from the
tank, means for transporting the widened fabric and a counteracting surface positioned
within the path of movement of the fabric so that the fabric strikes against it.
[0002] Known machines of this type have the drawback that if the fabric is not conveniently
centered about the fabric transporting means, it suffers substantial and permanent
damage, such as irreparable beating or even tearing, and in addition the fabric, especially
if wet, tends to wind about the transporting means.
[0003] It is already known to use so-called centering devices, however for their operation,
in the sense of detecting off-centering and correcting it on the basis of the detected
error, they use members which press on the fabric above the idle deviation roller
about which the fabric passes. The action of these members is controlled by a sensor,
and as it is intermittent it causes the fabric to undergo possibly unremovable creasing
when operating at the high speeds necessary for current production requirements.
[0004] The main object of the present invention is therefore to centre the fabric after
its widening such that the aforesaid drawbacks do not occur even when operating at
high speed and to prevent the fabric adhering to the transporting means by wrapping
around them.
[0005] A further object is to provide effective centering means of lesser technical and
constructional complication and hence of acceptable cost.
[0006] These and further objects which will be more apparent from the detailed description
given hereinafter are attained by a machine of the aforesaid type but improved in
accordance with the teachings contained in the accompanying claims.
[0007] The invention will be more apparent from the detailed description of some embodiments
thereof given hereinafter by way of non-limiting example and illustrated on the accompanying
drawings, in which:
Figure 1 is a schematic longitudinal vertical section through a first embodiment of
the machine of the invention;
Figure 2 is a perspective view of the centering means which are incorporated in all
the embodiments represented and described herein;
Figure 3 is a schematic side elevation showing the centering means of Figure 1 associated
with fabric off-centre sensing means;
Figure 4 is a perspective view of a different embodiment, the view being limited to
those parts of the machine relevant to the invention;
Figure 5 is a view analogous to that of Figure 1 showing a further embodiment of the
invention;
Figure 6 is a schematic side view of a further embodiment of the machine, the view
being limited to that which concerns the invention;
Figure 7 is a side view of an important detail which can be common to at least some
of the embodiments shown in the preceding figures.
[0008] With reference to Figures 1 to 3 and Figure 7, the machine for wet-treating fabrics
in open width, discontinuously in this case, comprises a usual metal tank 1.
[0009] The ends of the fabric to be treated, indicated by T, are sewn together in the usual
manner so that the fabric forms a ring. The direction of movement of the fabric is
indicated by the arrows A and B.
[0010] During its ascending movement (arrow A) the fabric passes through a conventional
widener 2. It comprises two identical rollers 3, 4 driven by an electric motor, not
shown, and supported for example by the sides of the tank. One of the rollers is visible
in the detailed view of Figure 2, in which it can be seen that, starting from its
centre line Z1, it possesses two helical projections, one right-handed and the other
left-handed, indicated respectively by 4* and 5. The two rollers are supported on
the sides of the tank by means of two arms 7 and two pins 8, one arm and one pin being
positioned at each of the two ends of the rollers 3, 4. A helical gear 9 is keyed
onto a pin emerging from the tank and engages a worm, not shown, operated by a handwheel,
also not shown, in order, inter alia, to enable said rollers to be correctly positioned
relative to the fabric T, the position being correct if the fabric adheres to the
two rollers. After passing through the widening device 2, where the fabric is widened
by the action of the opposing helical projections 4*, 5 on the rollers, the fabric
passes to a centering device 10.
[0011] This centering device comprises at least one idle roller 11 covered with elastic
material, eg rubber, able to exert a certain friction on the fabric T.
[0012] This roller is projectingly supported between two end plates 12 connected together
by a cross-member 13.
[0013] The cross-member is supported at each end by pairs of plates 14 via a hinge pin 15.
Each pair of plates is supported lowerly by a pin 16, which is rigid with a fixed
cross-member 17. The assembly formed by the cross-members 13, 17, the plates 14 and
the pins 15 and 16 forms an articulated parallelogram which is moved by a double-acting
pneumatic cylinder 18 hinged to a support 19 rigid with the cross-member 17 and whose
rod 20 is hinged at 21 to the upper cross-member 13.
[0014] The fabric T passes from the idle roller 11 to a fabric centering detection station
22. This station comprises an arrangement of means, photoemitters and photoreceivers,
for example light emitting diodes (LEDs), photodiodes, photoelectric cells and the
like, positioned to correspond with the longitudinal edges of the fabric when ideally
centered and extending transversely.
[0015] It is apparent that if the fabric is off-centre, the photoreceivers on the off-centered
side will be obscured.
[0016] A signal is hence produced which when suitably amplified causes valve means to operate
in order to drive the double-acting pneumatic cylinder 18 in the direction to zero
the off-centering.
[0017] Returning now to Figure 1, after passing the two deviation rollers 23 the fabric
T reaches a motorized endless band 28 where it is subjected to the pressing action
of an idle roller 24 supported by arms 25, which are hinged at 26 and are acted upon
by a pneumatic cylinder 27 which adjusts the pressure exerted on the fabric.
[0018] The band 28, which moves at relatively high speed, conveys the widened and centered
fabric to a device Z which launches the fabric against a counteracting surface 29
of adjustable position, to then fall onto the bottom of the tank and recommence the
described operating cycle.
[0019] The device 7 is shown in Figure 7 and is described in detail hereinafter with reference
to that figure.
[0020] The embodiment of Figure 4 shows very schematically both the widening device 2A and
the centering device 10A, which coincide with those shown in the preceding figures.
Downstream thereof, the fabric T encounters a pair of cooperating grooved rollers
40, one idle and the other driven, which are pressed against each other. The arched
teeth 41 of two comb structures 42 extend into the relative grooves, the teeth of
the lower structure being the longer and accompanying the fabric towards a motorised
device 43, in synchronism with the preceding, and consisting of three grooved rollers
44, 45, 46, belts 47 moving within their grooves. A grooved idle fourth roller 48
presses on the underlying roller 44 under the thrust of a pneumatic cylinder, not
shown, within its grooves there extending endless belts 90 which pass within the grooves
of a further preferably driven roller 91.
[0021] As will be more apparent from the description of Figure 7, the roller 91 corresponds
basically to the roller 70 (of Figure 7), and the belts 90 to the belts 47D, and in
the embodiment of Figure 4 fixed detachment bars 71 are provided, although not shown,
interposed between the belts.
[0022] To prevent the belts dragging the fabric with them beyond the roller 44, detachment
or separation bars 49 are interposed comb-like between the belts and are fixed at
their ends to cross-members 50. The bars 49 are arched and project beyond the plane
containing the belt portions extending between the rollers 44, 45.
[0023] As can be seen from Figure 4, a modified embodiment is possible in which the roller
46 is omitted, so that the belts pass from the roller 45 to the roller 44 (see line
R), this device being positioned close to the exit of the lower comb 41 to be able
to adequately receive the fabric. Alternatively, this comb can be lengthened. Basically
this modification coincides with the device Z of Figure 7.
[0024] The embodiment shown in Figure 5 comprises a tank 1B receiving the fabric T, the
widening device 2B and the centering device 10B with its sensors 22B. The fabric leaving
the sensors 22B passes about an idle deviation roller 50* to enter a bath 51, then
passes between two presser rollers 70, one idle and the other driven, these being
provided to exert a pressure on the passing fabric so as to drag it. The fabric then
reaches a device Z of Figure 7 and from here is launched against an adjustable counteracting
surface 29B before falling into the tank.
[0025] The arrangement is indicated by the preceding reference numerals accompanied by the
letter B.
[0026] The embodiment of Figure 6 comprises the widening device 2C, the centering device
10C with its sensors, and reversal rollers 60, the fabric T passing between two rollers,
a lower large-diameter one 61 and a smaller diameter one 62. The former is motorized
while the latter is idle and exerts on the former a pressure, for example by means
of a pneumatic cylinder. The fabric then passes through the device Z of Figure 7,
the components of which are consequently indicated by the same reference numerals
followed or not followed by a letter.
[0027] Before falling onto the tank bottom, the fabric, not shown, strikes against an adjustable
counteracting surface 29C similar to that of Figure 1 or to 29B of Figure 5.
[0028] Figure 7 shows the device Z (associated with the band 28 of Figure 1), comprising
the grooved roller 48A, 48B cooperating with belts 47D passing about a further grooved
roller 70 cooperating with interposed detachment bars 71 similar to the bars 49 (of
Figure 4).
[0029] The roller 48A, 48B cooperates with the grooved roller 44A, 44B, the grooves of which
receive the belts 47 between which the fabric detachment bars 49 extend.
[0030] The following modifications fall within the scope of the invention:
a) the use of 2 or 3 idle rollers instead of the single roller 11 of the centering
device 10 (these rollers being mounted spaced apart but mutually parallel on the rocking
structure which controls the centering roller 11);
b) the off-centre sensors, ie the members 22, can instead be mounted upstream of the
roller or rollers 11 of the centering device 10, ie between the widener 2 and roller
10, or can be provided both upstream and downstream of the roller or rollers 11.
1. A machine for discontinuously treating (scouring and/or fulling) fabrics particularly
of vegetable or synthetic fibres in open width, comprising a tank, means associated
therewith for advancing the fabric and means for widening and centering it, characterised
in that the centering means comprise means for detecting off-centering of the fabric,
to control a double-acting pneumatic piston which transversely shifts at least one
idle roller or a two or three-roller system depending on the off-centering, there
being provided driven exit means for the fabric to launch the fabric against a counteracting
surface and including members to prevent the fabric winding about or adhering to them.
2. A machine as claimed in claim 1, characterised in that downstream of the centering
device there is provided a driven endless band on which there presses at least one
idle rolling member controlled by pneumatic means, the fabric exit means being provided
downstream of the band.
3. A machine as claimed in claim 2, characterised in that the exit means are positioned
between the band and counteracting surface and comprise at least two grooved rollers
with endless belts passing within the grooves, into the spaces between the belts there
projecting bars for detaching any fabric adhering to the belts.
4. A machine as claimed in claim 3, characterised by comprising at least two pairs of
two grooved rollers with relative belts and detachment bars interposed between the
belts.
5. A machine as claimed in claim 1, characterised in that downstream of the centering
device there is provided a first pair of cooperating grooved rollers, into the relative
grooves there extending fixed or adjustable arched teeth or fingers.
6. A machine as claimed in claim 5, characterised in that downstream of the first pair
of grooved rollers there are provided grooved rollers carrying endless belts within
their grooves, arched bars for fabric detachment being positioned between these belts.
7. A machine as claimed in claim 1, characterised in that downstream of the centering
device there are provided a bath, pressing rollers and then an arrangement comprising
at least one pair of grooved rollers with belts and arched bars for fabric detachment,
and a counteracting surface against which the fabric strikes.
8. A machine as claimed in claim 1, characterised in that downstream of the centering
device there is provided a pair of cooperating rollers of substantially different
diameters, downstream of these there being provided an arrangement comprising at least
one pair of grooved rollers carrying endless belts within their grooves and with intermediate
arched bars for fabric detachment, downstream of this arrangement there being provided
a counteracting surface.