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(11) | EP 1 310 354 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A cardboard box-forming machine |
| (57) A magazine (2) of cardboard box blanks inferiorly exhibits an end from which a gripping
device (3) removes blanks one by one and releases them in a transfer zone (4). The
end is arranged obliquely with an inclination facing a box forming line (5) predisposed
to carry the blanks, once opened out into boxes, one by one in an advancement direction.
The transfer device comprises a rotating carousel which bears two gripping organs,
constituted by suckers and also rotating although in an opposite direction to and
faster than the rotating carousel. The machine is longitudinally notably short. |
[0003] A first of these improvements relates to reduction of the machines' mass, especially their longitudinal aspect; next comes a need to increase productivity; but also important is the simplification of construction.
[0004] The main aim of the present invention is to provide a machine able to overcome the above-mentioned limitations and lacks in the prior art.
[0005] A main advantage of the invention is that it provides a machine with a relatively contained longitudinal dimension.
[0006] A further advantage is that it provides a reliable and constructionally simple and economical machine.
[0009] These aims and advantages and more besides are all attained by the present invention, as it is characterised in the appended claims.
[0010] Further characteristics and advantages of the present invention will better emerge from the detailed description that follows of a preferred but non-exclusive embodiment of the invention, illustrated purely by way of a nonlimiting example in the accompanying figures of the drawings, in which:
figure 1 shows a vertical-elevation side view of a machine made according to the invention, with some parts removed better to evidence others;
figure 2 is a detail of figure 1;
figure 3 is a view from above of figure 2;
figure 4 is a sequence of some operative stages of an enlarged detail of figure 1.
[0012] With reference to the above-mentioned figures of the drawings, 1 denotes in its entirety a cardboard box-forming machine for making boxes destined for packaging objects. The machine 1 takes flat-packed blanks of cardboard and at least transforms the blanks into a box form, folding and gluing the flaps forming the bottom of the box. The machine operates in sequence and continuously for forming a succession of cardboard boxes at high speed.
[0013] The machine 1 comprises a magazine 2 of flat cardboard blanks and a gripping device 3 for fetching the blanks one by one from the magazine 2 and taking them to a transfer zone 4. The machine 1 also comprises a box-forming line 5 where the boxes C advance one behind another in a straight and horizontal advancement direction F starting from the transfer zone 4. The box-forming line 5 is provided with a plurality of forming devices for folding and gluing some flaps of the blank according to a predetermined cycle.
[0014] The blank magazine 2 is arranged obliquely above the box-forming line 5. The vertical projection of the magazine 2 occupies at least a part of the box-forming line 5; in the illustrated example it occupies at least the central part of the box-forming line 5, where the folding, pressing-together and gluing of the flaps of the boxes C take place. In the magazine 2 the flat blanks step-advance in an oblique direction G towards a lower end of the magazine 2, where they will be gripped one-by-one by the gripping device 3. The advancement direction G of the blanks in the magazine 2 is more-or-less coplanar to the advancement direction F of the boxes in the underlying box-forming line 5. The horizontal projection of the oblique advancement direction G of the blanks in the magazine, i.e. the projection with respect to the advancement direction F of the boxes in the forming line, reveals that the boxes move in an opposite direction during the continuously-advancing forming process than that which they follow in the supply process, i.e. when in the step-advancing magazine 2.
[0015] The lower end of the magazine 2, which the blanks are removed from, is arranged oblique with an inclination in the direction of the box-forming line 5.
[0016] The magazine 2, oblique with respect to the box-forming line 5, exhibits two tracts, having different inclinations and in which the final tract, which is the shorter, is more greatly inclined with respect to the longer tract of blank supply.
[0017] The magazine 2 has a lower rest base inferiorly delimiting the magazine 2 and on which the boxes C rest on their edges. The rest base is partially mobile towards the end at which the blanks are removed. In the illustrated example the mobile lower base is constituted by a ring-wound flexible organ 6 running on pulleys and having an upper branch which supports the lower edges of the blanks C. The position of the magazine 2 (in particular the end thereof which dispenses the blanks) can be adjusted at least with regard to the inclination thereof, and also in relation to its horizontal direction; in particular the relative distance thereof from the gripping device 3 can be adjusted. The magazine 2 exhibits, at the blank removal end, two lips 7, one upper and one lower, which the top and bottom edges of the front face of the blank C in the magazine strikes. The lips 7 constituted means for retaining the blanks C in the magazine 2 and provide means for reference for making sure that the blank in the "next" gripping position is precisely positioned for interaction with the gripping device 3.
[0018] The gripping device 3 comprises a carousel which can continuously rotate and which is located between the magazine 2 and the transfer zone 4. The carousel rotates on command about a rotation axis which is transversal (preferably perpendicular) to the advancement directions of the blanks in the magazine 2 and the boxes on the forming line. In the illustrated embodiment the rotation axis is horizontal, the carousel is mobile on a vertical plane on which lie the advancement directions G and F of the blanks/boxes respectively in the magazine 2 and along the forming line 5.
[0019] The carousel bears at least one gripping organ 8, for example a sucker, as in the illustrated embodiment, in which embodiment two are shown, located diametrically opposite one another. Each gripping organ 8, which in the specific case comprises two side-by-side and spaced suckers, is rotatably supported by the carousel and has a rotation axis which is parallel to the axis of the carousel itself. Each gripping organ 8 is predisposed to grip the boxes singly from the end of the magazine, in a zone situated between the end of the magazine 2 and the transfer zone 4. Each gripping organ 8 is also predisposed to transfer the blank C towards the transfer zone 4, where it is released.
[0020] In the illustrated embodiment, where the transfer zone 4 is located at a lower height than the end of the magazine 2, each gripping organ 8 grips the blank C when the carousel is moving in an upwards phase of its circular trajectory.
[0021] The gripping organ 8 is commanded to move continuously in a rotation direction K which is opposite to that of continuous rotation J of the carousel, at a higher speed. In the illustrated embodiment, for each rotation of the carousel, each gripping organ 8 makes two full rotations in direction K (as shown in figure 4); each gripping organ 8 is controlled in such a way that each time it passes by the dispensing end of the magazine 2 it is in the same configuration as in the previous rotation, and the suckers on the gripping organ 8 can remove the next blank C from the magazine 2. Each gripping organ 8 can be driven, for example, by a gearwheel (with a mobile rotation axis) which is coaxial and solid in rotation to the gripping organ 8, and coupled with a gearwheel having a fixed rotation axis (with a special gear ratio), also coaxial and solid in rotation with the carousel; the coupling between the two above-cited wheels can be made, as for example in the illustrated embodiment, by means of a flexible organ, for example of the chain type. Other types of means for driving could be used, however, for driving the gripping organs in rotation direction K.
[0022] The forming line 5 comprises a horizontal conveyor plane for the opened blanks C, now boxes. The conveyor plane bears a plurality of equidistanced projecting striker plates 9, each of which is destined, when it advances into the transfer zone 4, to interact strikingly with a back end of a box on the gripping device 3. The striker plates 9 are a reference for a correct positioning of the boxes along the forming line 5. The movement of the striker plates 9 (i.e. the movement of the conveyor plane) is synchronised with the rotation of the carousel and the gripping organs 8 so that a slight contact, which happens between an advancing striker plate 9 and a bottom corner of the box about to be deposited and released by the gripping organ 8 on the conveyor plane, causes the box to open completely. This stage is illustrated in figures 5 and 6.
[0023] The gripping organ 8 functions so that the base of the box in the transfer zone is practically coplanar to the conveyor plane (see figure 1) and also so that, once the box is completely transferred, the gripping action (in this case the action of the suckers) is released.
[0024] The forming line 5 comprises a mobile upper plane 10 (of known type) which interacts contactingly with the upper face of the boxes to make sure that the boxes once opened stay open as they move on the underlying conveyor plane.
[0025] The forming line 5 is provided with means for folding the flaps at the base of the box and with means for depositing drops of glue on the flaps. The means for folding comprise a plurality of fixed guides 11, 12 and 13 which are specially shaped so as to fold a front flap, an upper flap and a lower flap, and a shaped guide 14 with a vertical rotation axis, continuously rotating in synchrony with the advancement F of the boxes, which has the task of folding a back flap.
[0026] A pressor device 15 is located along the forming line 5 for keeping the glued flaps in position to enable the glue to take effect. The pressor device 15 comprises at least one mobile ring-wound flexible organ 16 (for example a chain conveyor), parallel to the advancement direction F of the forming line and mobile in synchrony with the box conveyor plane. In the illustrated embodiment two paired flexible organs 16 are provided, bearing a plurality of pressor elements 17 (four in the embodiment) distributed in steps along the flexible organ 16. Each pressor element 17 is mobile on command and can assume an inactive retracted position, in which it is external of a box advancing on the forming line 5, and an extended position (figure 3) in which it is inside the box and pressing the previously-glued and superposed flaps together, against an opposite mobile striker 18. The mobile striker 18, mobile in direction F, parallel and with the same advancement speed as the boxes (mobile on the forming line conveyor), and with respect to the pressor element 17 (mobile on the flexible organ of the pressor device), comprises an axially-vertical flexible organ (preferably a belt) running on pulleys.
[0027] Each pressor element 17 is commanded to assume the retracted or extended position by a hydraulic (preferably pneumatic) linear actuator 19, usually located on the flexible organs 16. The rotation axis of each actuator 19 is perpendicular to the advancement direction F of the boxes along the forming line 5 and the corresponding advancement the pressor element 17 makes in following the box. The actuators 19 are connected to a central unit controlling the whole machine, which synchronises the whole machine according to the passage of boxes along the forming line 5.
[0028] The movement of the flexible organ 16 and the advancement movement of the boxes on the forming line 5 are synchronised and powered by the same motor, which is controlled by the central unit through respective mechanical drive transmissions (of known type and not illustrated).
[0030] A gripping organ 8, borne by the rotating carousel and itself rotating on the carousel, at a certain point in its trajectory brings the suckers into aspirating contact with the last blank C in the end of the magazine 2. The blank C is gripped and transferred to the forming line 5, where it is opened by effect of its own weight and by contacting interaction with a striker 9 and the conveyor plane. The opened blank, or box, proceeds along the forming line 5, where it meets the shaped guides 11, 12, 13 and 14, both fixed and rotating, which bend and superpose the flaps forming the base of the box. The means for distributing glue, of known type and not illustrated, operate during this phase.
[0031] The pressor device 15 then keeps the by-now glued flaps pressed against each other: a pressor element 17 enters the box, following the advancing movement of the box for a sufficient time to ensure that the glue has taken, and is then retracted so as to be removed from inside the box. The movement of the pressor element 17, from extension to pressure to return, occurs while the pressor element 17 is mobile in direction F on a straight tract of the flexible organ 16.
1. A cardboard box-forming machine, comprising:
a magazine (2) for blanks of boxes;
a gripping device (3) for removing the blanks from the magazine (2) one at a time and releasing and opening out the blanks in a transfer zone (4);
a forming line (5) for boxes wherein the opened blanks advance one behind another in an advancement direction (f), starting from the transfer zone (4);
one or more forming devices (11, 12, 13, 14, 15) predisposed along the forming line, for folding and gluing some flaps of the boxes according to a predetermined cycle.
2. The machine of claim 1, characterised in that the magazine (2) is arranged above the forming line (5).
3. The machine of claim 1 or 2, characterised in that the magazine (2) inferiorly exhibits an end from which the gripping device (3) will
remove the blanks singly, the end being arranged at an oblique angle, with an inclination
towards the forming line (5).
4. The machine of any of the preceding claims, characterised in that the magazine (2) is arranged at an oblique angle with respect to the forming line
(5), and exhibits at least two tracts having different inclinations, with a final
tract having a greater inclination with respect to a preceding tract.
5. The machine of any one of the preceding claims, characterised in that the magazine (2) is arranged at an oblique angle with respect to the forming line
(5) and is provided with a lower rest base, which inferiorly delimits the magazine
(2) and on which the blanks rest on edges thereof; the lower rest base being at least
partly mobile towards an end at which the blanks will be removed singly by the gripping
device (3).
6. The machine of claim 5, characterised in that a mobile part of the lower rest base is constituted by a ring-wound mobile flexible
organ (6) having a branch which is in contact with lower edges of the blanks.
7. The machine of any one of the preceding claims, characterised in that the gripping device (3) comprises:
at least one carousel, able to rotate continuously and located between the magazine (2) and the transfer zone (4);
at least one gripping organ (8) which is mounted on the carousel and rotates together with the carousel, for singly gripping blanks from the magazine (2) during a tract in a rotation of the carousel, which tract is between the transfer zone (4) and the magazine (2), and for transferring the gripped blank towards the transfer zone (4) where the blank is to be released;
the gripping organ (8) being able to rotate with respect to the carousel, in a direction of rotation which is opposite a rotation direction of the carousel and which is faster in rotation than the carousel.
8. The machine of any one of the preceding claims, characterised in that the forming line (5) comprises a conveyor plane for the opened boxes, which plane
comprises a plurality of striker plates (9) which project from the conveyor plane
and which are distributed at stepped distances one from another; each of which plurality
of striker planes (9) is destined, on entering the transfer zone (4), to interact
strikingly with an end of a blank on the gripping device (3), helping to open the
blank into a box shape.
9. The machine of any one of the preceding claims, characterised in that:
a pressor device (15) is located along the forming line (5) for keeping glued flaps of the boxes pressed together to enable a glue to set;
the pressor device (15) comprises at least one continuously-moving ring-wound flexible organ (16) which is parallel to an advancement direction of the forming line (5) and which bears at least one pressor element (17) which is mobile on command and can assume at least one inactive retracted position, in which it is external of a box advancing on the forming line (5), and at least one active extended position in which it is inside the box advancing on the forming line (5);
the at least one pressor element (17) being commanded to assume the at least one active position and the at least one inactive position by a pneumatic linear actuator (19) solidly constrained to the flexible organ (16).
10. The machine of claim 9, characterised in that a continuous movement of the flexible organ, which is preferably a step-movement,
and the advancement movement of the boxes on the forming line (5), which is preferably
a continuous movement, are synchronised and powered by single motor through respective
mechanical transmissions.