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EP-4493368-B1 - AN IMPROVED APPARATUS FOR TRANSVERSALLY CUTTING TUBULAR BODIES

EP4493368B1EP 4493368 B1EP4493368 B1EP 4493368B1EP-4493368-B1

Inventors

  • TANCREDI, ANTONIO
  • BENVENUTI, STEFANO

Dates

Publication Date
20260506
Application Date
20230306

Claims (14)

  1. An apparatus (100) for transversally cutting a tubular body (1) having a predetermined thickness (t), said apparatus comprising: - a base frame (2); - a couple of cylinders (10) horizontally arranged parallel to each other at a predetermined distance, and configured to turn in a same direction about respective longitudinal axes (11) integral to said base frame (2); - an actuation means (20) for rotatably actuating said tubular body; - a cutting head (31) including: - a movable support (35) arranged to perform a displacement towards and away from said couple of cylinders (10); - an actuator arranged for causing said displacement of said movable support (35); - a circular blade (32) rotatably mounted to said movable support (35) about an own rotation axis (33), and arranged with an own cutting plane transversal to said cylinders (10), so that, by causing said circular blade (32) to rotate during said displacement of said movable support (35) towards said cylinders (10), said circular blade (32) transversally cuts said thickness (t) of said tubular body (1) arranged and rotatably moved on said cylinders (10); - an accompanying roller (40,40a,40b) rotatably mounted to an arm (42,42a,42b) and arranged to maintain said tubular body (1) in contact with said cylinders (10) during a rotation of said tubular body (1) on said cylinders (10), characterised in that said actuation means (20) of said tubular body (1) comprises a motor arranged to cause said cylinders (10) to rotate about said respective longitudinal axes (11), and in that said movable support (35) is arranged to perform said displacement, along with said circular blade (32), on an opposite side of said support (2) with respect to said cylinders (10), and in that said accompanying roller (40,40a,40b) is rotatably idle and arranged on the same side as said cylinders (10) with respect to said rotation axis (33) of said circular blade (32), and said arm (42,42a,42b): - is movably connected to said movable support (35) through a force member (44,44a,44b) selected between an elastic force member and a constant-force member, and - is arranged to move from a first raised position (A) to a lowered position (B) with respect to said movable support (35), wherein, in said raised position (A), said force member (44,44a,44b) is in a rest configuration, and a distance (D1) of said accompanying roller (40,40a,40b) from said cylinders (10) is shorter than a distance (DS) of said circular blade (32) from said cylinders (10), wherein, instead, in said lowered position (B), said force member (44,44a,44b) is in a working configuration, and said distance (D2) of said accompanying roller (40,40a,40b) from said cylinders (10) is longer than said distance (Ds) of said circular blade (32) from said cylinders (10) by a predetermined amount d which is at least equal to said thickness (t), that is, the relationship applies: t ≤ d = D 2 − D s .
  2. The apparatus (100) according to claim 1, wherein at least one linear guide member (3) extends from said base frame (2) on the same side as said cylinders (10) with respect to said base frame (2), and said movable support (35) comprises at least one housing (37) that is slidably mounted along said linear guide member (3).
  3. The apparatus (100) according to claim 2, wherein said first linear guide member (3) is a first linear guide member, and wherein: - said movable support (35) includes at least a second linear guide member (38), - said arm (42) comprises at least one housing (47) slidably mounted along said second linear guide member (38), and - said force member (44) is an elongated force member (44) having a first end portion (44') fixed to said movable support (35) and a second end portion (44") fixed to said arm (42).
  4. The apparatus (100) according to claim 2, wherein said arm (42) is rotatably mounted to said movable support (35) by means of a hinge (39), and wherein said force member (44) is selected from the group consisting of: - an elongated force member (44) having a first end portion (44') fixed to said movable support (35) and a second end portion (44") fixed to said arm (42); - a torsion spring integrated in said hinge (39).
  5. The apparatus (100) according to claim 3 or 4, wherein said elongated force member (44) is selected from the group consisting of: - a compression spring (44); - a pneumatic unit comprising a piston (45) and a cylinder (46) providing respective end portions (44',44") of said elongated force member (44), each selected between said first end portion and said second end portion (44',44"), wherein a chamber is formed between said piston (45) and said cylinder (46), said chamber containing an amount of a gas.
  6. The apparatus (100) according to claim 2, wherein said movable support (35) comprises: - a main support portion (53) comprising said housing (37) for engagement with said linear guide member (3), and - an articulated support portion (54,57) movably connected to the main support portion (53), wherein said circular blade (32) is rotatably mounted with said rotation axis (33) integral to said articulated support portion (54,57); - an actuator configured to move said articulated support portion (54,57) along with said circular blade (32) with respect to said main support portion (53).
  7. The apparatus (100) according to claim 6, wherein said articulated support portion (54) is slidably mounted to a further linear guide member (55) of said main support portion (53).
  8. The apparatus (100) according to claim 6, wherein said articulated support portion (57) is hinged to said main support portion (53).
  9. The apparatus (100) according to claim 1, wherein said movable support (35) is hinged to an extension (3) of said base frame (2).
  10. The apparatus (100) according to claim 1, wherein said cutting head (31) comprises two accompanying rollers (40a,40b) and two respective arms (42a,42b) as said accompanying roller and said arm, wherein said accompanying rollers (40a,40b) and said respective arms (42a,42b) are mounted on opposite sides with respect to said circular blade (32).
  11. The apparatus (100) according to claim 10, wherein said two arms (42a,42b) are movably connected to said movable support (35) through two respective force members (44a,44b) and wherein a downstream force member (44b) movably connecting said movable support (35) with a downstream arm (42b) of said accompanying roller (40b) arranged downstream of said circular blade (32), in a forward conveying direction (5) of said tubular body (1) towards said cutting head (31), is configured to apply a force between said movable support (35) and said downstream arm (42b) that is higher than a force applied by an upstream force member (44a) movably connecting said movable support (35) with an upstream arm (42a) of said accompanying roller (40a) that is arranged upstream of said circular blade (32), in said forward conveying direction (5).
  12. The apparatus (100) according to claim 1 or 10, wherein said or each accompanying roller (40a,40b) comprises a plurality of equal wheels (41) mounted to a same shaft or to a respective shaft (43) and arranged beside one another and spaced apart from one another by a predetermined pitch.
  13. The apparatus (100) according to claim 1, wherein said movable support (35) comprises a first box-like portion (34a), and a second box-like portion (34b) is arranged integral to said arm (42), said second box-like portion (34b) having an opening (48) through which a predetermined segment of said roller (40) protrudes, and providing a slit (49) configured to allow a predetermined segment of said circular blade (32) to protrude when said arm (42) is in said second position (B), said first and second box portions (34a-b) mutually arranged in such a way to form, during said displacement of said movable support (34a), a box-shaped protection casing.
  14. The apparatus (100) according to claim 1, further including a connection station (90) for forming a butt connection between tubular bodies (1).

Description

Scope of the invention The present invention relates to an apparatus for transversally cutting tubular bodies, such as tubular cores intended to support rolls of wound material. Brief description of the prior art Various equipment is known for transversally cutting tubular bodies that are made of such materials as pressed cardboard or plastic, and are suitable to serve as support cores for rolls of flexible strip or sheet material. Such equipment usually includes rotary circular saw blades. In order to improve the cutting precision, and to obtain smoother and cut edges, some equipment is configured to cause the tubular body to rotate about its longitudinal axis while being cut. Such an equipment is described, for instance, in WO 2008/114115 and WO 2013/017987. This equipment comprises a base member on which a cradle formed by parallel idle cylinders is arranged on which the tubular body rests. A peripheral friction drive roller is provided to rotate the tubular body about its longitudinal axis. The tubular body is caused to advance along the cradle and positioned at the cut position manually or by a motorised pusher. The circular blade is housed within the base member of the equipment, and is caused to rise from the base member up to a height suitable for cutting the tubular body. In order to allow the circular blade to come into contact the tubular body, the cradle is discontinued at the cutting position. In other words, the cradle is manufactured in two parts, each consisting of a couple of parallel idle cylinders arranged upstream and downstream of the cutting position, in the forward conveying direction of the tubular body. The equipment described above has the drawback of requiring a precise mutual alignment of the rotational axes of several rotating parts, in particular, the axis of each idle cylinder of one portion of the cradle must be precisely aligned with the axis of the corresponding idle cylinder of the other part of the cradle, all of them having a common direction, and the rotation axes of the circular blade and of the peripheral drive roller must be arranged parallel to this direction as well. Moreover, cut pieces as short as a few centimetres are difficult to obtain by the above-mentioned prior art equipment. Moreover, that prior art equipment fails to provide a cut pressure distribution even enough to keep the tubular body firmly resting on the cradle, in its cutting position. Summary of the invention It is therefore an object of the present invention to provide an apparatus for transversally cutting a tubular body that allows an easy and quick alignment of the rotating parts thereof. It is also an object of the invention to provide such an apparatus that allows easily cutting a tubular body into short pieces, in particular, into pieces as short as a few centimetres. It is also an object of the invention to provide such an apparatus that makes it possible to apply to the tubular body being cut a more even cut pressure, in order to further improve cutting accuracy. These and other purposes are achieved by an apparatus for transversally cutting a tubular body having a predetermined thickness as defined in claim 1. Advantageous embodiments and modifications of the apparatus are defined in the dependent claims. The apparatus includes: a base frame;a couple of cylinders horizontally arranged parallel to each other at a predetermined distance, and configured to turn in a same direction about respective longitudinal axes integral to the base frame;an actuation means for rotatably actuating the tubular body;a cutting head including in turn: a movable support arranged to perform a displacement towards and away from the couple of cylinders;a circular saw blade rotatably mounted to the movable support about its own rotation axis, which is integral to the movable support, and arranged with an own cutting plane or profile transversal to the cylinders, so that, by causing the circular blade to rotate during the displacement of the movable support towards the cylinders, the circular saw blade transversally cuts the thickness of the tubular body arranged and rotatably moved on the cylinders;an accompanying or positioning roller rotatably mounted to an arm and arranged to maintain the tubular body in contact with the cylinders during a rotation of the tubular body on the cylinders, wherein: the rotational actuation means of the tubular body comprises a motor arranged to cause the cylinders to rotate about respective longitudinal axes,the movable support is arranged to perform the displacement, along with the circular blade, on an opposite side of the support to the cylinders,the accompanying roller is rotatably idle and arranged on the same side as the cylinders with respect to the rotation axis of the circular blade, and the arm: is movably connected to the movable support through a force member selected between an elastic force member and a constant-force member, andis arranged to move from a first raise