EP3838777A1

EP3838777A1 - A crating/decrating machine, a method for crating/decrating objects and a method for retrofitting a crating/decrating machine

Info

Publication number: EP3838777A1
Application number: EP19217048.8A
Authority: EP
Inventors: Mauro Lanzi
Original assignee: Sidel End of Line and Tunnels Solutions SRL
Current assignee: Sidel End of Line and Tunnels Solutions SRL
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2021-06-23

Abstract

A crating/decrating machine (1) for inserting objects (10) in crates (11) and removing objects (10) from crates (11), comprising a stationary frame (2); a gripping assembly (3), which is movable alternately and in opposite directions between a gripping position and a release position with respect to the frame (2) along an open working path (W); and a first motor (4; 5), which is operatively connected to the gripping assembly (3), so as to cause the movement of the gripping assembly (3) between the gripping position and the release position; the first motor (4, 5) is rotatable in a first rotational direction (Dl; D2), when the gripping assembly moves (3) from the gripping position towards the release position; and in a second rotational direction (D2; D1), opposite to the first rotational direction (D1; D2), when the gripping assembly (3) moves from the release position towards the gripping position.

Description

The present invention relates to an automatic crating/decrating machine.
The present invention further relates to a method for crating/decrating objects and to a method for retrofitting a crating/decrating machine.
In general, crating/decrating machines are known with the purpose of inserting groups of objects in crates and removing groups of objects from crates.
As an example, known crating/decrating machines are used to remove returnable glass bottles from their crates, before their washing and sterilization treatments.
The known crating/decrating machines comprise a frame, which is stationary, and a gripping assembly, which moves alternately and in opposite directions along an open working path between a gripping position and a release position with respect to the frame.
The gripping assembly comprises, in turn, a plurality of gripping heads, which are configured to grip the objects to be crated/decrated.
Furthermore, the known crating/decrating machines usually comprise one or more electrical motors, which are mechanically connected to the gripping assembly through mechanical connection means, such as lever mechanisms, gear trains or the like.
In detail, the electrical motors continuously move in a single rotational direction, and the mechanical connection means are configured to transform the rotational movement of the motors into the alternate movement of the gripping assembly between the gripping and the release positions.
However, these mechanical connection means are complex and cause the machines to be rigid and scarcely adaptable to the necessity to modify the gripping or the release position.
In fact, if the gripping or the release position need to be modified, structural modifications of the mechanical connection means could be needed.
Modifications of lever mechanisms or gear trains may require a substantial redesigning of the machine and the substitution of parts, which may result in a great waste of time and resources.
In addition, in the known crating/decrating machines comprising two motors, the output shafts of the two motors are mechanically connected to each other.
In detail, the mechanical connection between the motors of the crating/decrating machines may cause phase shifting between the two motors, i.e. a difference between the angular positions of the respective output shafts at a given moment.
Phase shifting may result, in turn, in a less accurate control of the crating/decrating machines or in the interruption of the functioning of the machine.
A need is therefore felt within the industry for a crating/decrating machine, which can be conveniently adjusted without requiring major structural modifications and which can be accurately controlled.
It is an object of the present invention to provide a crating/decrating machine, allowing to meet the aforementioned need in a simple and cost-effective manner.
This object is achieved by a crating/decrating machine, as claimed in claim 1.
The invention also relates to a method for crating/decrating objects, as claimed in claim 7, and to a method of retrofitting of a crating/decrating machine, as claimed in claim 11.
One preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a crating/decrating machine according to the present invention;
Figures 2, 3 and 4 are lateral views of a portion of the crating/decrating machine of Figure 1 in respective sequential operative steps;
Figure 5 is an exploded and detailed view of the portion of Figures 2, 3 and 4;
Figure 6 is a front view of the crating/decrating machine of Figure 1;
Figure 7 is a lateral view of the crating/decrating machine of Figures 1 and 6; and
Figure 8 is a functional scheme of some components of the crating/decrating machine of Figures 1, 6 and 7.

In the following of the present description and in the claims the expression "in use" means "during operation".
With reference to Figure 1, numeral 20 indicates a crating/decrating system.
Crating/decrating system 20 comprises:

a crating/decrating machine 1, for inserting groups of objects 10 in respective crates 11 and removing groups of objects 10 from crates 11; and
a conveyor 12, on which crates 11 travel along an advancing direction A.

In detail, objects 10 are preferably bottles, containers or the like, which may be empty or filled with pourable products.
Crating/decrating machine 1, which will be hereinafter referred to as "machine", comprises, in turn (Figures 1, 6 and 7):

a frame 2, which is stationary;
a gripping assembly 3, which is movable alternately in opposite directions along an open working path W between a gripping position and a release position with respect to frame 2; and
two motors 4, 5, preferably electric, which are operatively connected to gripping assembly 3, so as to cause the alternate movement of gripping assembly 3 between the gripping position and the release position.

Motors 4, 5 are operatively connected to gripping assembly 3 at respective ends 3a, 3b of gripping assembly 3 along a direction X (Figure 6).
Preferably, motors 4, 5 are identical to each other.
In detail, motors 4 and 5 comprise respective gear trains (not shown) and have respective output shafts 54, 55, only schematically shown in Figure 8, which rotate at respective angular velocities ω1, ω2 about respective axes E, F.
In further detail, axes E and F are directed parallel to direction X (Figure 6).
In the embodiment shown, axes E and F are coincident.
In addition, output shafts 54, 55 are respective output shafts of gear trains of respective motors 4, 5.
In the embodiment shown, gear trains of respective motors 4, 5 are speed reducers.
In other words, motors 4 and 5 are gearmotors.
Furthermore, working path W is open because it comprises two opposite ends W1, W2, which are distinct and not coincident (Figure 5).
In detail, frame 2 comprises (Figures 1, 6 and 7):

two columns 6, 7, which are spaced from each other along direction X and are directed parallel to a direction Z, which is transversal to direction X; and
a supporting plate 8, which extends parallel to direction X and to a direction Y, which is transversal to directions X and Z.

During a crating operation, the gripping position is on frame 2 at supporting plate 8 and the release position is on conveyor 12 at crates 11.
On the contrary, during a decrating operation, the gripping position is on conveyor 12 at crates 11 and the release position is on frame 2 at supporting plate 8 (Figures 1 and 7).
In general, a crating operation of machine 1 comprises:

a gripping movement, in which objects 10 are gripped by gripping assembly 3 at the gripping position, i.e. supporting plate 8;
a first movement, in which gripping assembly 3 moves from the gripping position to the release position, i.e. crates 11;
a release movement, in which objects 10 are inserted by gripping assembly 3 in crates 11; and
a second movement, in which gripping assembly 3 moves back from the release position towards the gripping position.

A decrating operation of machine 1 comprises:

a gripping movement, in which objects 10 are gripped by gripping assembly 3 at the gripping position, i.e. crates 11;
a third movement, in which gripping assembly 3 moves from the gripping position to the release position, i.e. supporting plate 8 and objects 10 are removed from crates 11;
a release movement, in which objects 10 are released by gripping assembly 3 at the release position; and
a fourth movement, in which gripping assembly 3 moves back from the release position towards the gripping position.

In detail, supporting plate 8 is positioned between columns 6, 7 along direction X at a height h1 along direction Z with respect to the ground supporting frame 2 (Figures 1 and 6).
Furthermore, conveyor 12 is directed parallel to direction X and advancing direction A is parallel to direction X at least in proximity to machine 1.
Crates 11 travelling on conveyor 12 are positioned at a height h2 along direction Z with reference to the ground supporting frame 2 (Figures 6 and 7).
In addition, crates 11 travelling on conveyor 12 are placed alongside one another along advancing direction A.
In the embodiment shown, height h2 is smaller than height h1 (Figures 6 and 7).
Frame 2 further comprises, on each column 6, 7, a guide 41, which defines working path W of gripping assembly 3.
Each guide 41 is positioned in a respective plane B, C perpendicular to direction X and comprises (Figures 2, 3 and 4) :

a stretch 42, which is rectilinear and directed parallel to direction Z;
a stretch 43, which is rectilinear, directed parallel to direction Z and spaced from stretch 42 along direction Y; and
a stretch 44, which is curved and joins stretch 42 with stretch 43.

Stretch 42 comprises two opposite ends 42a, 42b along direction Z, only one of which (42a) is free.
Similarly, stretch 43 comprises two opposite ends 43a, 43b along direction Z, only one of which (43a) is free.
Stretch 44 extends between ends 42b and 43b.
In addition, end 42a is positioned at a lower height with respect to end 42b along direction Z and end 43a is positioned at a lower height with respect to end 43b along direction Z.
In the embodiment shown, stretches 42, 43 have different length and, in particular, stretch 42 is longer than stretch 43 along direction Z.
As a consequence, end 42a is positioned at a lower height with respect to end 43a along direction Z.
In addition, ends 42b and 43b are preferably positioned at the same height along direction Z.
In other words, each guide 41 is preferably J-shaped or U-shaped.
Furthermore, gripping assembly 3 is positioned between columns 6, 7 along direction X and comprises (Figures 1, 6 and 7):

gripping means 9, which are configured to grip objects 10 to be crated/decrated;
a support 14, which holds gripping means 9; and
two sliders 17, sliding in respective guides 41 of respective columns 6, 7.

Gripping assembly 3 further comprises (Figures 1 and 6) :

two beams 18, 19, which hold support 14;
two articulated systems 16, on both ends of beams 18, 19 along direction X, which operatively connect beams 18, 19 to frame 2; and
two elements 23, which are fixed to both beams 18, 19 on respective both ends of beams 18, 19 along direction X.

In detail, gripping means 9 comprise a plurality of gripping heads 13 for gripping respective objects 10.
Gripping heads 13 are equal to one another and are operatively connected to support 14 by means of respective springs (not shown).
In the embodiment shown, gripping heads 13 are pneumatic.
Preferably, gripping heads 13 are directed parallel to direction Z throughout the operation of machine 1 and are aligned along directions X and/or Y.
In further detail, each gripping head 13 comprises a deformable membrane 15 at its respective lowermost end along direction Z, which is inflated or deflated, so as to fit the exterior shape of objects 10 and to individually grip one respective object 10.
Support 14 comprises, in turn (Figures 2, 3, 4 and 7):

a plate 21, to which gripping heads 13 are attached at their respective uppermost ends along direction Z, opposite to respective membranes 15; and
a connection 22, which operatively connects plate 21 to beams 18, 19.

Furthermore, beams 18, 19 are directed parallel to direction X and extend between columns 6, 7 (Figure 1).
In addition, beams 18, 19 are spaced from each other along direction Y and the cross-section of beams 18, 19 is C-shaped.
Beams 18, 19 and elements 23 move integrally with one another.
Furthermore, in the embodiment shown, slider 17 comprises rotatable support means.
Preferably, rotatable support means of slider 17 is a roller bearing.
Sliders 17 slide in sequence along stretches 43, 44, 42 during the first movement of the crating operation and in sequence along stretches 42, 44, 43 of respective guides 41 during the third movement of the decrating operation of machine 1.
In detail, during the first movement of the crating operation, the sliding of sliders 17 from end 43a towards end 43b corresponds to an upwardly translation of support 14 along direction Z; the sliding of sliders 17 from end 43b towards end 42b along stretch 44 corresponds to a translation of support 14 along a curved trajectory of respective planes B, C and the sliding of sliders 17 from end 42b towards end 42a corresponds to a downwardly translation of support 14 along direction Z.
In addition, during the third movement of the decrating operation, the sliding of sliders 17 from end 42a towards end 42b corresponds to an upwardly translation of support 14 along direction Z; the sliding of sliders 17 from end 42b towards end 43b along stretch 44 corresponds to a translation of support 14 along the curved trajectory of respective planes B, C and the sliding of sliders 17 from end 43b towards end 43a corresponds to a downwardly translation of support 14 along direction Z.
In addition, sliders 17 slide in sequence along stretches 42, 44, 43 of respective guides 41 during the second movement of the crating operation and in sequence along stretches 43, 44, 42 during the fourth movement of the decrating operation.
In the following, only one articulated system 16 is disclosed, being articulated systems 16 identical to one another.
Articulated system 16 allows support 14 to be moved between the gripping and the release positions with respect to frame 2, while maintaining gripping heads 13 in parallel to direction Z (Figures 2, 3 and 4).
In detail, articulated system 16 comprises (Figures 2 to 5):

a movement unit 50, which is adapted to alternately move support 14 along working path W; and
a balancing unit 51, which is adapted to keep support 14 perpendicular to direction Z during the movement of gripping assembly 3 along working path W.

In the following of the present description, a fixed hinge is a pinned support, i.e. a structural constraint allowing the structural member to which it is applied to rotate, but not to translate in any direction.
In detail, the position of a fixed hinge is unmovable with respect to frame 2.
Furthermore, in the following of the present description, a mobile hinge is a structural constraint allowing mutual rotation between the structural members to which it is applied, but not mutual translation.
In detail, the position of the mobile hinge is movable with respect to frame 2.
Movement unit 50 comprises, in turn (Figures 2 to 5):

a crank 30, which is hinged to frame 2 by means of a fixed hinge O; and
a rod 31, which is hinged to slider 17.

Balancing unit 51 comprises:

two cranks 32, 33, which are hinged to frame 2 by means of respective fixed hinges P, Q;
element 34; and
three rods 35, 36, 37.

In detail, crank 30 comprises two opposite ends 30a, 30b and rod 31 comprises two opposite ends 31a, 31b.
In further detail, crank 30 is hinged at end 30a to fixed hinge O. As a consequence, crank 30 is rotatable about hinge O with respect to frame 2.
Crank 30 and rod 31 are articulated to each other by means of a mobile hinge R at respective ends 30b, 31b.
In addition, rod 31 is hinged to slider 17 at end 31a by means of a mobile hinge S.
Furthermore, end 31a and slider 17 overlap each other along direction X and move integrally with each other along working path W (Figure 5).
As a consequence, the rotation of crank 30 about hinge O corresponds to the translation of slider 17 along working path W.
Rod 31 is further operatively connected to element 23 at end 31a by means of hinge S.
As a consequence, the translation of slider 17 along working path W corresponds to the translation of element 23 and beams 18, 19.
Furthermore, cranks 32, 33, elements 34 and rods 35, 36, 37 have respective opposite ends 32a, 32b, 33a, 33b, 34a, 34b, 35a, 35b, 36a, 36b, 37a, 37b (Figures 2 to 5).
Cranks 32, 33 are hinged to frame 2 by means of respective fixed hinges P, Q at their respective ends 32a, 33a.
Rod 35 and rod 37 are hinged at respective ends 35a, 37a to hinge S.
In detail, rod 35 and rod 37 are interposed between rod 31 and element 23 along direction X and superimposed on slider 17 (Figure 6).
As a consequence, the translation of slider 17 causes the movement of the balancing unit 51.
Furthermore, rod 36 is hinged to rod 35 by means of a mobile hinge T. In detail, rod 36 and rod 35 are hinged to each other at respective ends 36a, 35b.
In addition, cranks 32, 33 and rods 36, 37 are hinged to element 34 at their respective ends 32b, 33b, 36b, 37b,
In detail, cranks 32, 33 are hinged to element 34 by means of respective mobile hinges U, V.
Rods 36, 37 are hinged to element 34 by means of respective mobile hinges J, V.
In further detail, hinges U and J are positioned at respective ends 34a, 34b of element 34. Hinge V is positioned at the midpoint of element 34.
Furthermore, in the embodiment shown, articulated system 16 is arranged on three levels I, II, III, proceeding from one column 6, 7 to the other column 7, 6 along direction X (Figure 6).
In particular, crank 30 and rod 31 are arranged in first level I, which is the closest one to column 6, 7.
Cranks 32, 33, element 34 and rods 36, 37 are arranged in second level II, which is spaced from first level I along direction X.
Rod 35 is arranged in third level III, which is the furthest from column 6, 7 and the closest to element 23.
Advantageously, each motor 4, 5 rotates in:

a rotational direction D1, when gripping assembly 3 moves from the gripping position towards the release position; and
a rotational direction D2, opposite to rotational direction D1, when gripping assembly 3 moves from the release position towards the gripping position.

Both motors 4, 5 rotate in the same rotational direction D1 or D2.
As an example, rotational direction D1 is clockwise and rotational direction D2 is anti-clockwise or vice versa.
In the embodiment shown, with reference to Figure 1, during the first movement of a crating operation of machine 1, in which objects 10 are inserted in crates 11, motors 4, 5 rotate anti-clockwise.
Still with reference to Figure 1, during the third movement of a decrating operation of machine 1, in which objects 10 are removed from crates 11, motors 4, 5 rotate clockwise.
In addition, motors 4, 5 are directly connected to respective cranks 30 of respective articulated systems 16.
This means that motors 4, 5 are operatively connected to the respective cranks 30 without any interposed element and output shafts 54, 55 are directly responsible for the rotation of respective cranks 30 about respective hinges O.
Furthermore, output shafts 54, 55 are arranged coaxially with hinge O.
As a consequence, each hinge O lies on axes E and F.
No gear train is interposed between output shafts 54, 55 and respective cranks 30.
In addition, output shafts 54, 55 are connected to respective cranks 30 in such a way that output shafts 54, 55 and respective cranks 30 rotate at the same respective angular velocities ω1, ω2.
Furthermore, machine 1 comprises (Figure 8):

two position transducers 64, 65, which are adapted to detect respective first and second data corresponding to the rotation of respective motors 4, 5;
adjustment means 74, 75 of an operational parameter of respective motors 4, 5, which are adapted to control the angular velocities ω1, ω2 of respective motors 4, 5; and
a control unit 80, which is configured to analyze the first and/or second data detected by position transducers 64, 65 and to determine, on the basis of the first and/or second data, the rotation of motors 4, 5 in rotational directions D1 or D2 by adjustment means 74, 75.

Furthermore, motors 4, 5 form a master/slave system, in which the angular velocity of the master motor serves as the speed reference for the slave motor.
In the embodiment shown, motor 4 is the master motor and motor 5 is the slave motor.
In detail, motors 4, 5 form a master/slave system because adjustment means 74, 75, which are related to respective motors 4, 5, are in logical communication with each other by means of a bus 76 (Figure 8).
As a consequence, control unit 80 directly controls adjustment means 74 and indirectly controls adjustment means 75.
In other words, control unit 80 is functionally connected to motors 4 and 5.
In the embodiment shown, each position transducer 64, 65 comprises an encoder.
In detail, each position transducer 64, 65 is located at respective output shaft 54, 55.
In the embodiment shown, the first datum corresponding to the rotation of motor 4 is an angle of rotation θ1 of output shaft 54 and angular velocity ω1.
Furthermore, the second datum corresponding to the rotation of motor 5 is an angle of rotation θ2 of output shaft 55 and angular velocity ω2.
Angles of rotation θ1, θ1 are measured with respect to a reference angle of rotation θ*.
In detail, angles of rotation θ1, θ2 are equal to respective values θ1g, θ2g when gripping assembly 3 is in the gripping position and to respective values θ1r, θ2r when gripping assembly 3 is in the release position.
As an example, reference angle of rotation θ* of output shafts 54, 55 is the angular position of output shafts 54, 55 when respective motors 4, 5 are switched-off.
In the embodiment shown, adjustment means 74, 75 comprise respective inverters.
Furthermore, the operational parameter of motors 4, 5 is any operational parameter of electric motors (voltage, electric current, etc.).
In the embodiment shown, adjustment means 74, 75 adjust at least the frequency of motors 4, 5.
Adjustment means 74, 75 and control unit 80 are configured to control motors 4, 5, so as to guarantee that each motor 4, 5 rotates in rotational directions D1 or D2, depending on whether gripping assembly 3 has to be moved from the gripping position towards the release position or from the release position towards the gripping position, respectively.
In detail, position transducers 64, 65 are configured to send to respective adjustment means 74, 75 the respective first and second data corresponding to the rotation of motors 4, 5.
Control unit 80 is adapted to compare angles of rotation θ1, θ2 with values θ1g, θ2g, θ1r, θ2r and to control adjustment means 74, 75 to determine the rotation of motors 4, 5 in rotational directions D1 or D2.
Furthermore, adjustment means 74, 75 and control unit 80 are configured to control motors 4, 5, so as to guarantee that motors 4, 5 synchronously rotate with each other.
In detail, motors 4, 5 synchronously rotate with each other when respective output shafts 54, 55 are in corresponding angular positions instant by instant.
In further detail, output shafts 54, 55 are in corresponding angular positions at a given time, when they have been rotated by respective angles θ1, θ2 with respect to reference angle of rotation θ* in the same time interval and angles θ1, θ2 have equal amplitude.
Motors 4, 5, position transducers 64, 65, adjustment means 74, 75 and control unit 80 define a multi-motor synchronous control system.
In detail, adjustment means 74, 75 are adapted to receive the first and second data corresponding to the rotation of respective motors 4, 5 from respective position transducers 64, 65.
Furthermore, control unit 80 is adapted to compare the first and second data received from adjustment means 74, 75, so as to determine whether motors 4 and 5 are synchronous with each other.
In the embodiment shown, control unit 80 is adapted to compare the amplitude of angles of rotation θ1, θ2 of respective shafts 54, 55, in order to identify whether output shafts 54, 55 are in the same angular position at a given time.
Control unit 80 is further adapted to send a correction signal to adjustment means 74, 75, in case motors 4, 5 are detected not to be synchronous at a given time.
In further detail, the correction signal corresponds to a modification of the angular position of shafts 54 or 55.
Adjustment means 74, 75 implement the modification of the angular position of shaft 54 and/or 55 by modifying angular velocity ω1 and/or ω2 of respective shafts 54, 55.
The operation of crating/decrating machine 1 is described with reference to a crating operation of machine 1.
The crating operation of machine 1 starts with the gripping movement, in which objects 10 are gripped by gripping assembly 3 at the gripping position, which is at supporting plate 8.
In this condition, angles of rotation θ1, θ2 of respective shafts 54, 55 are equal to respective values θ1g, θ2g.
During the gripping movement, gripping heads 13 individually grip one respective object 10.
The gripping movement of the crating operation is followed by the first movement from the gripping position to the release position, which is at crates 11.
In detail, during the first movement of the crating operation, control unit 80 controls motors 4, 5 to rotate in rotational direction D1 with respective speeds ω1, ω2, preferably being of the same magnitude.
Since motors 4, 5 are directly connected to cranks 30 of respective articulated systems 16, the rotation of shafts 54, 55 causes the rotation of cranks 30 about respective hinges O.
The rotation of cranks 30 about respective hinges O causes the movement of movement unit 50 and balancing unit 51.
As a consequence, support 14 which supports gripping heads 13 and the respective gripped objects 10 is moved along working path W from the gripping position to the release position and is kept perpendicular to direction Z.
In addition, during the first movement, sliders 17 move along respective guides 41 on columns 6, 7 along stretches 43, 44, 42 in sequence.
In the embodiment shown, with reference to Figure 1 rotational direction D1 of motors 4, 5 during the first movement of the crating operation is anti-clockwise.
Once gripping assembly 3 has reached the release position, objects 10 are inserted in crates 11 travelling on conveyor 12 along advancing direction A during the release movement of the crating operation.
In this condition, angles of rotation θ1, θ2 of respective shafts 54, 55 are equal to respective values θ1r, θ2r.
After completion of the release movement, the crating operation continues with the second movement, in which gripping assembly 3 moves back from the release position towards the gripping position.
Preferably, no object 10 is gripped by gripping assembly 3 during the second movement.
In detail, during the second movement of the crating operation, control unit 80 controls motors 4, 5 to rotate in rotational direction D2, opposite to rotational direction D1, with respective speeds ω1, ω2, preferably being of the same magnitude.
Since motors 4, 5 are directly connected to cranks 30 of respective articulated systems 16, the rotation of shafts 54, 55 causes the rotation of cranks 30 about respective hinges O.
The rotation of cranks 30 about respective hinges O causes the movement of movement unit 50 and balancing unit 51.
As a consequence, support 14 which supports gripping heads 13 is moved along working path W from the release position towards the gripping position and is kept perpendicular to direction Z.
In addition, during the second movement, sliders 17 move along respective guides 41 on columns 6, 7 along stretches 42, 44, 43 in sequence.
In the embodiment shown, with reference to Figure 1, rotational direction D2 of motors 4, 5 during the second movement of the crating operation is clockwise.
Throughout the crating operation, control unit 80 compares the first and the second data corresponding to the rotation of motors 4, 5, so as to determine if motors 4, 5 are synchronous with each other.
In detail, control unit 80 compares instant by instant the amplitude of angles of rotation θ1, θ2 of respective shafts 54, 55, in order to identify whether output shafts 54, 55 are in the same angular position at a given time.
In case output shafts 54, 55 are detected to be in different angular positions at a given time, control unit 80 sends a correction signal to adjustment means 74, 75.
Adjustment means 74, 75, which are in logical communication with each other by means of bus 76, modify angular velocity ω1 and/or ω2 of respective shafts 54, 55 according to the correction signal.
The operation of crating/decrating machine 1 is not described in detail with reference to a decrating operation of machine 1, for the sake of brevity.
In detail, during the decrating operation, the gripping position is at crates 11 and the release position is at supporting plate 8.
With reference to Figure 1, during the third movement of the decrating operation, control unit 80 controls motors 4, 5 to rotate in rotational direction D1, which is clockwise; during the fourth movement of the decrating operation, control unit 80 controls motors 4, 5 to rotate in rotational direction D2, which is anticlockwise.
Since motors 4, 5 are directly connected to cranks 30 of respective articulated systems 16, the rotation of shafts 54, 55 causes the rotation of cranks 30 about respective hinges O and the movement of movement unit 50 and balancing unit 51.
As a consequence, support 14, which supports gripping heads 13 and the respective gripped objects 10, is moved along working path W from the gripping position towards the release position and is kept perpendicular to direction Z.
Throughout the decrating operation, control unit 80 compares the first and the second data corresponding to the rotation of motors 4, 5, so as to determine if motors 4, 5 are synchronous with each other.
In detail, control unit 80 compares with one another and instant by instant the amplitude of angles of rotation θ1, θ2 of respective shafts 54, 55, in order to identify if output shafts 54, 55 are in the same angular position at a given time.
In case output shafts 54, 55 are detected to be in different angular positions at a given time, control unit 80 sends a correction signal to adjustment means 74, 75 and adjustment means 74, 75 modify angular velocity ω1 and/or ω2 of respective shafts 54, 55 according to the correction signal.
The retrofitting of crating/decrating machine 1 is described with reference to an initial condition, in which motors 4, 5 are mechanically connected to gripping assembly 3 through mechanical connection means, not shown, such as lever mechanisms, gear trains or the like.
In addition, in this initial condition, output shafts 54, 55 of respective motors 4, 5 are mechanically connected to each other.
The retrofitting of machine 1 starts with the removal of the mechanical connection means between respective motors 4, 5.
Subsequently, output shafts 54, 55 of respective motors 4, 5 are directly connected to gripping assembly 3.
In detail, output shafts 54, 55 are coaxially arranged with respect to respective cranks 30 of gripping assembly 3.
Control unit 80 is then functionally connected to motors 4 and/or 5 so as to determine the rotation of motors 4 and/or 5 in the first or second rotational directions D1, D2 with the aim of causing the alternate movement of gripping assembly 3 between the gripping position and the release position (Figure 8).
Subsequently, adjustment means 74, 75 of respective motors 4, 5 are put in logical communication with each other by means of bus 76 without any mechanical connection therebetween (Figure 8).
In addition, control unit 80 is functionally connected with adjustment means 74, 75, so as to guarantee that motors 4, 5 are synchronous with each other.
The advantages of the crating/decrating machine and of the methods according to the present invention will be clear from the above description.
In particular, since each motor 4, 5 rotates alternately in rotational directions D1 or D2, depending on whether gripping assembly 3 moves from the gripping position towards the release position or vice versa, machine 1 does not need to comprise any complex lever mechanisms to transform the rotational movement of motors 4, 5 into the alternate movement of gripping assembly 3, differently from the known solutions discussed in the introductory part of the present description.
In addition, since motors 4, 5 are directly connected to gripping assembly 3, machine 1 does not require any complex lever mechanisms to transmit the motion from motors 4, 5 to gripping assembly 3.
As a consequence, machine 1 is far more flexible and conveniently adaptable to the necessity to modify the gripping or the release position than the known crating/decrating machines discussed in the introductory part of the present description.
In fact, when the gripping or the release position of machine 1 needs to be modified, no structural modifications of complex lever mechanisms or gear trains are needed.
Furthermore, adjustment means 74, 75 are in logical communication by means of bus 76 and control unit 80 is adapted to control adjustment means 74, 75, so as to guarantee that respective output shafts 54, 55 are in corresponding angular positions at a given time with respect to reference angle of rotation θ*.
Accordingly, machine 1 can be conveniently controlled.
In fact, differently from the known crating/decrating machines, output shafts 54, 55 of respective motors 4, 5 are not mechanically connected to each other and any phase shifting between the two motors is thus avoided or at least reduced.
Furthermore, since the known crating/decrating machines can be easily retrofitted according to the claimed method for retrofitting, the drawbacks of the known crating/decrating machines can be conveniently overcome, without using a completely new crating/decrating machine.
In this way, the service life of the known crating/decrating machines can be extended, with evident economic and environmental benefits.
Finally, it is apparent that modifications and variants not departing from the scope of protection of the claims may be made to machine 1 and to the methods according to the present invention.
In particular, machine 1 could comprise only one motor 4, 5, arranged at only one end 3a, 3b of gripping assembly 3 along direction X.

Claims

A crating/decrating machine (1) for inserting objects (10) in crates (11) and removing objects (10) from crates (11), comprising:
- a frame (2), which is stationary;

- a gripping assembly (3), which is movable alternately and in opposite directions between a gripping position and a release position with respect to said frame (2) along an open working path (W); and

- at least one first motor (4; 5), which is operatively connected to said gripping assembly (3), so as to cause the movement of said gripping assembly (3) between said gripping position and said release position;
characterized in that said at least one first motor (4; 5) is rotatable, in use, in:
- a first rotational direction (D1; D2), when said gripping assembly moves (3), in use, from said gripping position towards said release position; and

- a second rotational direction (D2; D1), opposite to said first rotational direction (D1; D2), when said gripping assembly (3) moves, in use, from said release position towards said gripping position.
The crating/decrating machine of claim 1, characterized in that said at least one first motor (4; 5) is directly connected to said gripping assembly (3).
The crating/decrating machine of claims 1 or 2, characterized in that said gripping assembly (3) comprises:
- gripping means (9), which are configured to grip said objects (10) to be crated/decrated; and

- at least one articulated system (16), which is adapted to move said gripping means (9) with respect to said frame (2) ;
said articulated system (16) comprising a crank (30), which is hinged to said frame (2) by means of a fixed hinge (O);
said at least one first motor (4; 5) comprising a respective first output shaft (54; 55), which is coaxial to said crank (30);
said first output shaft (54; 55) being connected to said crank (30) in such a way that said first output shaft (54; 55) and said crank (30) rotate, in use, at the same angular velocity (ω1; ω2).
The crating/decrating machine of any one of the foregoing claims, characterized in that said at least one first motor (4; 5) comprises a gear train, which drives in rotation, in use, said first output shaft (54; 55) and is directly connected to said first output shaft (54; 55).
The crating/decrating machine of any one of the foregoing claims, characterized by further comprising:
- at least one first position transducer (64; 65), which is adapted to detect a first datum (θ1, ω1; θ2, ω2) corresponding to the rotation of said at least one first motor (4; 5);

- first adjustment means (74; 75) of at least one operational parameter of said at least one first motor (4; 5); and

- a control unit (80), which is adapted to analyze said first datum (θ1, ω1; θ2, ω2) detected, in use, by said first position transducer (64; 65) and to determine, on the basis of said first datum (θ1, ω1; θ2, ω2), the rotation of said at least one first motor (4; 5) in said first or second rotational directions (D1, D2) by said first adjustment means (74; 75).
The crating/decrating machine of claim 5, characterized by comprising:
- a second motor (5; 4), with a respective second output shaft (55; 54);

- a second position transducer (65; 64), which is adapted to detect a second datum (θ2, ω2; θ1, ω1) corresponding to the rotation of said second motor (5; 4); and

- second adjustment means (75; 74) of said at least one operational parameter of said second motor (5; 4); said first and second adjustment means (74, 75; 75, 74) being in logical communication with each other by means of a bus (76);
said control unit (80) being further adapted to control, on the basis of said first and second data (θ1, ω1, θ2, ω2; θ2, ω2, θ1, ω1) said first and second adjustment means (74, 75; 75, 74), so as to guarantee that said first and second motors (4, 5; 5, 4) are synchronous with each other.
Method for crating/decrating objects (10) in/from crates (11) with a crating/decrating machine (1) comprising the steps of:
i) alternately moving a gripping assembly (3) of said crating/decrating machine (1) with at least one first motor (4; 5) of said crating/decrating machine (1) between a gripping position and a release position with respect to a frame (2) of said crating/decrating machine (1) along an open working path (W) and in opposite directions;
characterized by comprising the further steps of:
ii) rotating said at least one first motor (4; 5) in a first rotational direction (D1; D2), when said gripping assembly moves (3) from said gripping position towards said release position; and

iii) rotating said at least one first motor (4; 5) in a second rotational direction (D2; D1), opposite to said first rotational direction (D1; D2), when said gripping assembly (3) moves from said release position towards said gripping position.
The method of claim 7, characterized by comprising the further step of iv) rotating a first output shaft (54; 55) of said at least one first motor (4; 5) at the same angular velocity (ω1; ω2) of said crank (30).
The method of claims 7 or 8, characterized by comprising the further steps of:
v) detecting a first datum (θ1, ω1; θ2, ω2) corresponding to the rotation of said at least one first motor (4; 5) by means of at least one first position transducer (64; 65) of said crating/decrating machine (1);

vi) analyzing said first datum (θ1, ω1; θ2, ω2) by means of a control unit (80) of said crating/decrating machine (1); and

vii) controlling the rotation of said at least one first motor (4; 5) in said first or second rotational directions (D1, D2; D2, D1) with said control unit (80) by first adjustment means (74; 75) of said crating/decrating machine (1) on the basis of said first datum (θ1, ω1; θ2, ω2).
The method of claim 9, characterized by comprising the further steps of:
viii) detecting a second datum (θ2, ω2; θ1, ω1) corresponding to the rotation of a second motor (5; 4) of said crating/decrating machine (1) by means of a second position transducer (65; 64);

ix) putting in logical communication said first adjustment means (74; 75) with second adjustment means (75; 74) of said crating/decrating machine (1) by means of a bus (76); said first and second adjustment means (74, 75; 75, 74) being related to said first and second motors (4, 5; 5, 4), respectively; and

x) controlling said first and second adjustment means (74, 75; 75, 74), on the basis of said first and second data (θ1, ω1, θ2, ω2; θ2, ω2, θ1, ω1), by means of said control unit (80), so as to guarantee that said first and second motors (4, 5; 5, 4) are synchronous with each other.
Method for retrofitting a crating/decrating machine (1); said crating/decrating machine (1) comprising:
- a frame (2), which is stationary;

- a gripping assembly (3), which is movable alternately and in opposite directions between a gripping position and a release position with respect to said frame (2) along an open working path (W); and

- at least one first motor (4; 5);
said method being characterized by comprising the steps of:
xi) directly connecting a first output shaft (54; 55) of said at least one first motor (4; 5) to said gripping assembly (3); and

xii) functionally connecting a control unit (80) of said crating/decrating machine (1) with said at least one first motor (4; 5), so as to determine the rotation of said at least one first motor (4; 5) in a first or a second rotational directions (D1; D2; D2, D1), with the aim of causing the alternate movement of said gripping assembly (3) between said gripping position and said release position; said first rotational direction (D1; D2) being opposite to said second rotational direction (D2; D1).
The method of claim 11, characterized by comprising the further steps of:
xiii) directly connecting a second output shaft (55; 54) of at least one second motor (5; 4) to said gripping assembly (3);

xiv) putting in logical communication with each other first and second adjustment means (74, 75; 75, 74) of at least one operational parameter of respective said first and second motors (4, 5; 5, 4) by means of a bus (76) without any mechanical connection therebetween; and

xv) functionally connecting said control unit (80) with said first and second adjustment means (74, 75; 74, 75), so as to guarantee that said first and second motors (4, 5; 5, 4) are synchronous with each other.
The method of claim 12, characterized in that said step xiii) is further executed by the step of:
xvi) coaxially arranging a first and a second output shafts (54, 55; 55, 54) of respective said first and second motors (4, 5; 5, 4) with respect to respective cranks (30) of said gripping assembly (3).