Object of the Invention
[0001] The present invention relates to a bobbin forming device applicable to roving frames,
of the type comprising a spindle for positioning the tube on which the bobbin will
be formed, and a rotating flange, provided with a pressing finger, which rotates concentrically
with respect to the tube, said rotating flange being responsible for twisting the
rove to be wound onto the tube.
Background of the Invention
[0002] Roving frames generally have a plurality of bobbin forming devices which are responsible
for forming bobbins with the roves provided by the drafting device of the roving frame.
[0003] These bobbin forming devices comprise a rotating flange which receives the rove on
its upper part and delivers it to the tube positioned on the corresponding spindle
by means of an oscillating pressing finger which leans tangentially on the outline
of the forming bobbin.
[0004] The mentioned bobbins are connected by means of a mechanical transmission with a
motor element responsible for providing them with a rotational movement.
[0005] In turn, the spindles on which the tubes are assembled are connected to a mechanical
transmission that communicates the rotating movement to them from a motor.
[0006] Currently in roving frames, the flange and bobbin assembled on the corresponding
spindle rotate in the same direction, the rotational speed of the tube being greater
than the rotational speed of the flange, so that the rove is wound on the bobbin in
a rotational direction opposite to the rotational direction of the tube and of the
flange.
[0007] Given that during bobbin formation the rotational speed of the tube is greater than
the rotational speed of the flange, it is the tube that draws or pulls the rove provided
by the flange.
[0008] To carry out a correct rove delivery to the bobbin, the oscillating pressing finger
of the flange is oriented towards the previous area of the flange with the rotational
direction of said flange as a reference.
[0009] To achieve the winding of the rove onto the tube, the tube rotates at a greater speed
than the flange, this difference in speed being the winding speed of the rove onto
the tube.
[0010] In current roving frames, the production capacity can only be increased by increasing
the rotational speed of the tube, which has technical limitations because from a certain
speed, and especially when the forming bobbin reaches a certain diameter, the centrifugal
force causes the expansion and deterioration of the rove which is being produced.
[0011] The technical problem that is posed is the development of a bobbin forming device
that allows reducing the rotational speed of the tube, obtaining the same production,
and subsequently reducing the negative effects of the centrifugal force of the obtained
rove, or allowing a higher maximum assembly speed thus obtaining a higher production.
Description of the Invention
[0012] To solve the technical problem posed, a bobbin forming device applicable to roving
frames, object of this invention, has been devised, which, like the ones previously
described, comprises a spindle for positioning the tube on which the bobbin will be
formed, and a rotating flange, provided with an oscillating pressing finger, that
rotates concentrically around the tube, said rotating flange being responsible for
twisting the rove to be wound onto the tube.
[0013] The device of this invention has the particularity that the rotational speed of the
tube is less than the rotational speed of the flange and the oscillating pressing
finger is oriented towards the rear area of the flange with the rotational direction
of said flange as a reference.
[0014] The flange and the tube rotate in the same direction during bobbin formation, the
flange being, due its greater speed, the one that winds the rove onto the bobbin,
which rotates at a lower speed.
[0015] With this device, it is the flange which is responsible for pulling the provided
thread onto the bobbin because the flange rotates at a greater speed than the tube.
[0016] Therefore, in comparison to current roving frames, this bobbin forming device allows
obtaining the same production by rotating the tube at a lower speed, or increasing
the roving frame production without the tube reaching rotational speeds in which the
centrifugal force negatively affects the obtained rove bobbin quality.
[0017] The main advantages of this device are: an increase in production (higher winding
speed with less spindle and tube revolutions), a lower consumption, better quality,
a lower risk of rove breakage and a lower deterioration of the bobbin due to centrifugal
forces.
[0018] Another feature of this device is that the tube carrying spindle on which the bobbin
is formed can be assembled on the roving frame with the possibility of rotating freely,
without a connection to any mechanical operation element, because the tension generated
in the rove due to the greater rotational speed of the flange and the coincidence
in the rotational directions of the flange and the winding of the rove onto the tube
causes a suitable rotation of the tube and the carrying spindle of the same.
[0019] In this case, it has been contemplated that the device can incorporate a braking
device responsible for acting on the tube to prevent its acceleration or excess rotation
due to the centrifugal force itself. The possibility of assembling the spindle without
mechanical traction produces other important advantages such as the possibility of
dispensing with both mechanical and electronic communication with the provision of
rove produced by drafting, because the spindle or bobbin speed is systematically adjusted
according to the provision of rove produced by drafting.
[0020] Obviously, this device can also be used in those roving frames in which the spindle
is mechanically connected by a suitable means of transmission with a drive motor.
Description of the Drawings
[0021] To complement the description which is being carried out and with the aim of easily
understanding the features of the invention, a set of drawings is herein enclosed
in which, in an illustrating and non-limiting way, the following has been depicted:
- Figure 1 shows a diagrammatic elevational view of an embodiment of the device of the
invention, in which the unassembled tube aligned with the spindle has been depicted,
the rotational directions of the spindle and the flange having been referenced by
arrows.
- Figure 2 corresponds to section A-A' of the device during bobbin formation, the oscillating
pressing finger having been depicted slightly spaced from the forming bobbin, and
not in tangential contact with it, to aid in the comprehension of the explanation
which will be carried out below.
Preferred Embodiment of the Invention
[0022] In the embodiment shown in Figure 1, the device of the invention can be observed,
comprising a rotating flange (1) which receives a rotational movement from a mechanical
transmission depicted in this embodiment by a toothed pulley (2) and the corresponding
toothed belt (3). The device further comprises a spindle (4) for the assembly of a
tube (5) on which the rove bobbin will be formed.
[0023] The flange has the particularity that the oscillating pressing finger (6) responsible
for supplying the rove (7) with which the bobbin (8) will be formed on the tube (5)
is oriented towards the rear area of the flange, with the rotational direction of
the flange and the bobbin as a reference, which is a clockwise direction in this specific
embodiment.
[0024] As can be observed in Figure 2, the flange (2) carrying the oscillating pressing
finger (6) and the tube (5) associated to the corresponding spindle (4) rotate in
the same direction, the rotational speed (St) of the tube (5) being lower than the
rotational speed (Sf) of the flange.
[0025] The speed of the flange (Sf), which is greater than the speed of the tube (St), causes
a tension in the rove (7) supplied to the bobbin (8), the rove (7) being wound onto
the bobbin in the same rotational direction as the flange (1) and the tube (5).
[0026] The tension produced in the rove (7) due to the difference in speeds between the
flange and the tube may be enough in certain cases and depending on the type and material
of the rove, to cause the rotation of the tube (5) and of the spindle (4) without
said spindle (4) being driven by a motor.
[0027] In these cases, the spindle (4) can be assembled with the possibility of rotating
freely on the roving frame and can be provided with a braking device which is not
depicted and can be of any type, to prevent the spindle (4) and subsequently the forming
bobbin (8) from rotating uncontrollably or at a speed greater than the one desired,
due to the force of inertia.
[0028] Having sufficiently described the nature of the invention as well as a preferred
embodiment, it is stated for the record that the materials, shape, size and arrangement
of the described elements may be modified, as long as it does not entail altering
the essential features of the invention which are claimed below.
1. A bobbin forming device applicable to roving frames, of the type comprising a spindle
(4) for positioning the tube (5) on which the rove bobbin (8) will be formed, and
a rotating flange (1), provided with an oscillating pressing finger (6), which rotates
concentrically around the tube (5), said rotating flange (1) being responsible for
twisting the rove (7) to be wound onto the tube (5), characterized in that the rotational speed (St) of the tube (5) is lower than the rotational speed (Sf)
of the flange (1), and in that the pressing finger (6) is oriented towards the rear area of the flange (1) with
the rotational direction of said flange (1) as a reference.
2. A device according to claim 1, characterized in that the flange (1) and the tube (5) rotate in the same direction during bobbin (8) formation.
3. A device according to the previous claims, characterized in that the spindle (4) carrying the tube (5) is assembled on the roving frame with the possibility
of rotating freely and is not connected to any mechanical drive element.