A feeler gripper for a palletizing device, and a palletizing device comprising it

Abstract

The invention relates to a feeler gripper (1) comprising a support plate (3) configured to be connected to a robotic arm; at least one sliding rod (4) extending vertically downwards from the support plate (3); a gripper body (5) mounted to slide on at least one sliding rod (4) and configured to move vertically relative to the support plate (3) along at least one sliding rod (4), said gripper body (5) carrying a retractable horizontal support member and a vertical pressing member configured to grasp a package to be palletized; and a position sensor (13) configured to detect a change in the position of the gripper body (5) relative to the support plate (3). Figure to be published with the abstract: Figure 2

Description

Title of the invention: Sensor gripper for palletizing device, and palletizing device comprising it

[0001] The present invention relates to the field of palletizing, and relates in particular to a sensor gripper for a palletizing device and to a palletizing device comprising such a sensor gripper.

[0002] When handling goods, such as bundles or stacks of printed matter, pallets are generally used, said bundles being placed on the pallets either manually by an operator or automatically by a palletizing robot.

[0003] Since the printed matter packages are made up of notebooks or books that are not integral, elastic and asymmetrical, or even sliding, relative to each other inside the package, the palletizing task is made complex for a palletizing robot (particularly when dropping the package onto the pallet) and therefore requires complex grippers and technologies.

[0004] Palletizing robots are known which allow packages, such as packages of printed matter, to be palletized automatically using fork grippers. These existing robots are composed of centering modules and grouping modules allowing packages to be picked up in pairs and palletized in pairs. However, these robots are bulky and oversized compared to the application, and are particularly intended for palletizing heavy masses.

[0005] There are also machines that allow packages to be palletized automatically using a gripper with retractable grippers and lugs. However, these existing machines have the following disadvantages: the packages are taken from above by the gripper with retractable grippers and lugs, i.e. at two of the four side faces of the package; the packages need to be flat without a spine or a strongly pronounced protrusion; and the packages are dropped from a certain height onto the pallet, which is unsuitable for asymmetrical bulky packages such as unbound book signatures with the fold of the binding as they are produced at the exit of folders. In addition, the design of the gripper with retractable clamps and lugs implies large spaces between the packages placed on the pallet, which reduces the stability of the pallet and the palletizing capacity (i.e., the number of notebooks per pallet).

[0006] Holding a package from above by a gripper requires the package to be released at a certain height from the pallet, which separates the bulky magazines. Thus, in practice, existing machines are unable to palletize packages made up of magazines with more than 16 pages (or 8 sheets) since these productions are bulky. They are therefore unable to palletize 32-page bulky magazines due to the phenomenon of air trapped in the bulky packs which makes the stacks of paper behave like compressed springs in the gripper which suddenly relax when placed on the pallet, which leads to damage and loss of loose booklets / magazines from the stack of booklets or sheets, and very long placement times which slows down the machines or limits the ranges of packs they can palletize.

[0007] Some manufacturers have sought to compensate for these defects by jogging or very slow depositing movements so as not to cause shocks / collisions between the pack and the lower layer which would stop the machine. However, this type of technical shortcut only allows a pack to be partially realigned lengthwise but not widthwise and, in any case, does not allow one or more possible notebooks which have come out of the pack and which would need to be realigned to be realigned.

[0008] French patent application FR3110152A1 discloses a collaborative robot palletizer. However, this palletizer, which is useful for non-bulky applications, has the defect of not compensating for the heights of packages due to the air inflation. The previously palletized layers are thus crushed under the weight of the upper layers and the robotic palletizer cannot guess the altitude at which to deposit the package. The palletizer must then “guess” by calculation the random or exponential position of the thicknesses of the previously deposited layers to approximately reach the previous position, which means that, if the package to be palletized is not deposited by direct contact on the lower layer, then there is a risk that the package of magazines not linked together will break up / become detached and that notebooks will fall either onto the lower layer or onto the ground, thus damaging the current pallet and disrupting the depositing of subsequent packages.The same result occurs when it comes to unwrapped reams of paper or packs of single sheets, printed or not.

[0009] It should also be noted that the arrangement of a probe on the gripper of a collaborative robot would not be appropriate, given that the vibrations induced by the parasitic movement of a probe during the movements of the robot would be seen by the collaborative robot as a shock against an operator.

[0010] The present invention aims to solve the drawbacks of the prior art by proposing a sensor gripper capable of detecting the contact of the lower part of the gripper with a depositing surface, indicating the presence of the depositing surface under a package to be palletized gripped by the gripper, thus allowing the deposit of the package to be palletized directly on the depositing surface.

[0011] The present invention therefore relates to a sensor gripper for a palletizing device, said gripper being configured to be carried by a robotic arm of a palletizing device, said gripper comprising, in the lower part, at least one retractable horizontal support member and, in the upper part, a vertical pressing member configured to grip between them a package to be palletized, characterized in that said gripper further comprises:

[0012] - a support plate configured to be connected to the end of the robotic arm;

[0013] - at least one sliding rod extending vertically downwards from the support plate;

[0014] - a gripper body slidably mounted on the at least one sliding rod and suspended vertically relative to the support plate, configured to move vertically relative to the support plate along the at least one sliding rod, said gripper body carrying the at least one retractable horizontal support member and the vertical pressing member; and

[0015] - a position sensor carried by one of the gripper body and the plate support, the position sensor being configured to detect a change in position of the gripper body relative to the support plate,

[0016] wherein, when the lower portion of the gripper body contacts a deposition surface, the gripper body slides upwards along the at least one slide rod, resulting in a detection of a change in the relative position of the gripper body and the support plate by the position sensor, indicating the presence of the deposition surface beneath the gripped palletized package, thereby enabling the deposition of the gripped palletized package directly onto the deposition surface by retraction of the at least one support member.

[0017] Thus, the sensor gripper according to the present invention is of reduced size and has a sliding system which makes it possible to place the package to be palletized in contact with the deposition surface such as the lower layer or the lower package on the pallet (i.e., the last layer or the last package placed on the pallet).

[0018] The sensor gripper according to the present invention thus makes it possible to come into contact with the lower layer of the pallet to place the package to be palletized by contact on the lower layer, even if the altitude of the lower layer is unknown or known approximately by the palletizing device, all without the disadvantages of releases from a certain height and the associated shocks occurring with conventional palletizers.

[0019] The position sensor of the feeler gripper according to the present invention makes it possible to detect the upward sliding of the gripper body along the at least one sliding rod when the gripper body comes into contact with the lower layer of the pallet, in order to detect and inform the automation chain of the altitude of the previous layer in order to perform a realignment at each layer and to follow the altitude of the pallet of magazine packs which gradually settle.

[0020] Having a gripper with a retractable horizontal support member, rather than a clamp, allows the packages to be deposited by contact and avoids dropping the packages at a certain height above the previously formed layer, which avoids disassembling the stack of magazines, books, book bodies or reams of unwrapped / held paper.

[0021] The gripper with retractable horizontal support member also makes it possible to place stacks of packages in a close-knit manner and to obtain a pallet with greater stability.

[0022] The sensor gripper according to the present invention makes it possible to grip packages of all kinds such as fragile paper documents, magazines, reams of paper, including asymmetrical bulky packages.

[0023] The present invention thus makes it possible to have a palletizing device with the widest possible operating spectrum on the production of packages delivered by upstream equipment such as shaping folders, in particular bulky packages with variable thickness due to the presence of air before compression by the weight of the upper layers once placed on the pallet.

[0024] According to a particular characteristic of the invention, the position sensor is a proximity sensor of the inductive, laser or photoelectric type, carried by the gripper body and configured to detect the presence / absence of the support plate opposite the latter as a function of the sliding position of the gripper body on the at least one sliding rod.

[0025] Thus, when the gripper body is not resting on a deposition surface, the support plate is located above and not opposite the position sensor so that the latter does not detect the support plate (the reaching of the deposition surface by the gripper body is then not detected by the gripper). On the contrary, when the gripper body is resting on a deposition surface, the gripper body slides upwards along the at least one sliding rod so that the support plate is opposite the position sensor, the latter then detecting the support plate (the reaching of the deposition surface by the gripper body is then detected by the gripper).

[0026] According to a particular characteristic of the invention, the gripper further comprises a weight compensation system arranged between the support plate and the gripper body and configured to perform compensation for the weight of the gripper body when empty.

[0027] The weight compensation system prevents the gripper body from come to crush or even damage in an untimely manner the packages previously placed on the pallet.

[0028] Thus, when the gripper body comes into contact with the lower layer, only the weight of the gripped package rests on this lower layer.

[0029] According to a particular characteristic of the invention, the weight compensation system is one of at least one spring and at least one cylinder, arranged between the support plate and the gripper body.

[0030] The at least one spring is prestressed so as to compensate for the weight of the gripper body when empty.

[0031] The at least one spring is thus a balancing system which makes it possible to compensate for the weight of the empty gripper body in order to detect the contact of the lower layer as precisely as possible in order to reduce the crushing of the lower layer.

[0032] According to a particular characteristic of the invention, the at least one sliding rod is made up of first and second parallel sliding rods on which the gripper body is slidably mounted, the at least one spring being made up of a first spring arranged on the side of the first sliding rod and a second spring arranged on the side of the second sliding rod.

[0033] According to a particular characteristic of the invention, the gripper further comprises a sliding locking cylinder arranged on the gripper body and configured to lock the sliding of the gripper body on the at least one sliding rod, the gripper being configured to activate the sliding locking cylinder during the phases of gripping the package and moving the package and to deactivate the sliding locking cylinder during the phase of palletizing the package.

[0034] Thus, the sliding locking cylinder makes it possible to lock and neutralize the movements of the gripper body relative to the support plate, during the movement of the robotic arm at high industrial production speeds.

[0035] The actuation of the sliding locking cylinder type lock during the rapid transfer phases of the robotic arm and the package gripping phases before palletizing makes it possible to avoid jolts or variations in inertia on the robotic arm which can disrupt the automation and be detected as collisions.

[0036] The opening of the sliding locking cylinder type lock, on the contrary, allows the gripping body to slide during the palletizing phases, that is to say during the phases of approach and contact with the depositing surface and during the phase of depositing the gripped package on the depositing surface.

[0037] According to a particular characteristic of the invention, the at least one retractable horizontal support member consists of two parallel retractable horizontal blades forming a fork.

[0038] Thus, the two horizontal blades forming a fork make it possible to obtain better support for the package on them, said horizontal blades being retractable inside the gripper body so as to allow the grasped package to be placed on the placement surface.

[0039] According to a particular characteristic of the invention, the vertical pressing member consists of at least one vertical pressing cylinder, optionally carrying a pressing pad opposite the at least one horizontal support member.

[0040] Thus, once the robotic arm has moved the gripper so as to place the at least one support member in the deployed state under the package to be gripped, the package is gripped by the gripper by lowering the rod of the at least one pressing cylinder until its free end (or pressing pad) is in contact with the top of the package, which makes it possible to ensure that the package is blocked between the at least one deployed horizontal support member and the at least one pressing cylinder of the gripper.

[0041] The package is thus grasped in the direction of its thickness and not in the direction of its width, which makes it possible to overcome the difficulties created by the back of the printed matter.

[0042] According to a particular characteristic of the invention, the gripper further comprises two pivoting arms mounted on either side of the gripper body, each of the two pivoting arms carrying at least three suction cups, each pivoting arm, in its deployed position, carrying the suction cups under the at least one horizontal support member to form a horizontal suction cup suction plane, the gripper being configured to deploy the two pivoting arms so as to grip an interlayer sheet by suction using the suction cups.

[0043] Thus, the two pivoting arms with suction cups make it possible to grip an interlayer sheet by suction and place it on the lower layer of the pallet, prior to placing the first package of the next layer on the pallet.

[0044] Each pivoting arm can, for example, carry three suction cups arranged to form a triangle, or four suction cups arranged to form a cross.

[0045] The present invention also relates to a palletizing device comprising a conveyor and a robotic arm carrying a gripper as described above, said palletizing device being configured to grasp, using the at least one retractable horizontal support member and the pressing member of the gripper, a package to be palletized present at the outlet of the conveyor, to move, using the robotic arm, the grasped package to be palletized to a depositing surface, and to deposit, by retraction of the at least one support member of the gripper, the package to be palletized directly on the depositing surface only after detection, by the position sensor of the gripper, of a change in the relative position of the gripper body and the support plate, indicating the presence of the depositing surface below the package to be palletized.

[0046] According to a particular characteristic of the invention, the palletizing device further comprises, at the outlet of the conveyor, an alignment system comprising two parallel lateral vertical plates arranged on either side of the outlet of the conveyor, at least one of the two vertical plates being movable, using a plate displacement cylinder, in the direction perpendicular to the direction of movement of the conveyor such that the two vertical plates are configured to align the package to be palletized on two of its four lateral faces, at least one of the two vertical plates carrying a vertical stop which comprises a surface perpendicular to said vertical plate, the gripper body carrying a vertical surface configured to push the package to be palletized against the stop so as to align the package to be palletized on the other two of its four lateral faces.

[0047] The alignment system allows the package to be palletized to be automatically aligned (or jogged) on its four side faces at the exit of the conveyor.

[0048] The width of the stop of the alignment system is less than the width of the conveyor, preferably less than half the width of the conveyor, and even more preferably less than a third, a quarter, a fifth, etc. of the width of the conveyor.

[0049] The conveyor of the palletizing device transports the packages to be palletized from its input to its output, the packages to be palletized being able, for example, to come from a shaping folder in the case of packages of printed matter. Each time a package to be palletized is present at the output of the conveyor, the lateral vertical plates (which constitute the first and second jogging faces) of the alignment system allow the automatic alignment (or jogging) of the package on two of its four lateral faces. The gripper then advances into the output of the conveyor so that its vertical surface (which constitutes the third jogging face) pushes the package towards the vertical flat surface of the stop (which constitutes the fourth jogging face) of the alignment system, so that the package is automatically aligned (or jogging) on ​​its four lateral faces.

[0050] In the present invention, the alignment of the four lateral faces of the bundle is thus achieved by the three vertical planes of the alignment system (namely, the two lateral vertical plates and the perpendicular stop) plus the plane constituted by the front face of the gripper, so as to align the bundle on its four lateral faces to have a precise palletization reference and precision in the result of the pallet subsequently formed, but also to realign the notebooks or books inside the bundle.

[0051] Thus, the bundle is accurately realigned on the conveyor and the notebooks within the bundle are accurately recentered.

[0052] The stop of the alignment system preferably has a height identical to that of the vertical plates.

[0053] Furthermore, the stop preferably has a very small width compared to that of the package to be palletized. After jogging, the package is thus blocked by the two lateral vertical plates, by the vertical surface of the gripper and by the stop, the width of which is limited and does not cover the entire corresponding lateral face of the package. Jogging the package by the two lateral vertical plates of the alignment system before the gripper advances makes it possible to guarantee the jogging of the package between the vertical surface of the gripper and the stop, even if the stop has a very small width compared to that of the package. Indeed, since the package is already aligned on three lateral faces, a simple stop (namely, the stop) is sufficient for the alignment of the fourth lateral face.The fourth alignment face thus comprises a real part constituted by the stop and a “virtual” part constituted by the space between the stop and the other vertical plate of the alignment system.

[0054] The stop of the alignment system thus constitutes the generator of the plane constituting the fourth alignment face, however this plane does not need to be the entire width of the associated lateral face of the package, due to the presence of the three other alignment faces which align the three other lateral faces of the parallelepiped shape of the package, the stop only constituting a reference on the remaining dimension.

[0055] The at least one horizontal support member (in the lower part) and the vertical pressing member (in the upper part) of the gripper make it possible to grip the aligned package, the at least one deployed horizontal support member being in contact with the lower part of the package and the deployed vertical pressing member being in contact with the upper part of the package, the package thus being locked in position between the at least one deployed horizontal support member and the deployed vertical pressing member of the gripper.

[0056] The robotic arm then makes it possible to move the gripped package so as to place it on a pallet or on an already palletized package by retracting at least one horizontal support member of the gripper.

[0057] Preferably, only one of the two vertical plates is movable via the plate moving cylinder. However, both vertical plates could also be movable, without departing from the scope of the present invention. For example, one of the vertical plates could be movable using the plate moving cylinder, and the other of the vertical plates could be movable manually.

[0058] Advantageously, the stop of the alignment system is a right angle return which constitutes the fourth alignment face against which the package comes into abutment when it is pushed by the gripper. The square return is dimensioned so that only a part of the corresponding lateral face of the package comes into contact with it, the precision of the alignment between the gripper and the square return being guaranteed by the prior alignment of the package between the two lateral vertical plates of the alignment system.

[0059] According to a particular characteristic of the invention, the outlet of the conveyor comprises at least one longitudinal notch configured to receive the at least one deployed support member of the gripper.

[0060] Thus, the at least one longitudinal notch in the outlet of the conveyor allows the introduction of the at least one deployed horizontal support member of the gripper therein, so as to allow the positioning of the at least one deployed horizontal support member under the package to be palletized present at the outlet of the conveyor.

[0061] The conveyor may be a roller or belt conveyor, the at least one longitudinal notch being, in this case, formed in the rollers or the belt at the outlet of the conveyor.

[0062] To better illustrate the object of the present invention, a preferred embodiment will be described below, by way of illustration and not limitation, with reference to the appended drawings.

[0063] In these drawings:

[0064] [Fig. 1] is a perspective view of a feeler gripper according to one embodiment of the present invention;

[0065] [Fig.2] is another perspective view of the gripper of [Fig.l];

[0066] [Fig.3] is an enlargement of [Fig.l] at the level of the sliding rods of the gripper;

[0067] [Fig.4] is a side view of the gripper carrying a package;

[0068] [Fig.5] is a side view of the gripper in contact with a deposition surface;

[0069] [Fig.6] is a side view of the gripper after retraction of its support member horizontal retractable above the deposition surface;

[0070] [Fig.7] is a perspective view of a palletizing device according to a method of embodiment of the present invention; and

[0071] [Fig.8] is a perspective view of the conveyor outlet of the puck device tization of [Fig.7].

[0072] Referring to Figures 1 to 3, it can be seen that there is shown a sensor gripper 1 for a palletizing device according to an embodiment of the present invention.

[0073] The gripper 1 is carried by a robotic arm 2 such as a six-axis robotic arm.

[0074] The gripper 1 comprises a horizontal support plate 3 which is fixed to the end 2a of the robotic arm 2 and from which extend vertically downwards two sliding rods 4.

[0075] The gripper 1 further comprises a gripper body 5 comprising a front portion 5a slidably mounted on the two sliding rods 4, such that the gripper body 5 is suspended vertically relative to the support plate 3.

[0076] The gripper body 5 can thus move vertically relative to the support plate 3 along the two sliding rods 4.

[0077] The gripper body 5 carries, in the lower part, as a support member, two parallel horizontal blades 6 forming a fork, said two blades 6 being retractable inside the gripper body 5.

[0078] The gripper body 5 also carries, in the upper part, as a vertical pressing member, a vertical pressing cylinder 7 carrying a pressing shoe 7a opposite the two horizontal blades 6.

[0079] The gripper 1 is configured to grip a package to be palletized (in the direction of its thickness) between the two horizontal blades 6 and the pressing pad 7a. For this, the robotic arm 2 moves the gripper 1 so as to place the two horizontal blades 6 in the deployed state under a package to be gripped, then the package is gripped by the gripper 1 by lowering the rod of the pressing cylinder 7 until the pressing pad 7a is in contact with the top of the package, which makes it possible to ensure that the package is blocked between the two deployed blades 6 and the pressing pad 7a.

[0080] The two horizontal blades 6 are connected to a carriage 8 arranged inside the gripper body 5, said carriage 8 being movable in translation inside the gripper body 5, by means of a chain 9 driven by pinions 10 themselves driven in rotation using a motor 11. The translation of the carriage 8 in the bottom of the gripper body 5 makes it possible to completely retract the blades 6 inside the gripper body 5 or to deploy the blades 6 outside the gripper body 5.

[0081] The gripper 1 further comprises a position sensor 13 (visible in [Fig.2]) carried by the gripper body 5 at the support plate 3, the position sensor 13 being configured to detect a change in position of the gripper body 5 relative to the support plate 3.

[0082] Thus, after gripping a package to be palletized, when the robotic arm 2 moves the gripper 1 so that the lower part of the gripper body 5 comes into contact with a depositing surface, the gripper body 5 then slides upwards along the sliding rods 4, which causes the position sensor 13 to detect a change in position of the gripper body 5 relative to the support plate 3, indicating to the gripper 1 the presence of the depositing surface under the gripped package to be palletized, thus allowing the depositing of the gripped package to be palletized directly on the depositing surface by retraction of the two retractable blades 6.

[0083] The gripper 1 further comprises, as a weight compensation system, two springs 14 fixed between the support plate 3 and the front part 5a of the gripper body 5, the two springs 14 allowing compensation of the weight of the gripper body 5 when empty.

[0084] It should be noted that the two springs 14 could also be replaced by at least one weight compensation cylinder, without departing from the scope of the present invention.

[0085] The springs 14 are prestressed so as to compensate for the weight of the gripper body 5 when empty, such that, when the gripper body 5 comes into contact with the depositing surface, only the weight of the gripped package rests on the depositing surface, which makes it possible to prevent the gripper body 5 from accidentally crushing or even damaging the packages previously deposited on the pallet.

[0086] The gripper 1 further comprises a sliding locking cylinder 15 (visible in Figures 1 and 3) arranged on the gripper body 5 and configured, when the cylinder rod 15 is deployed as shown in [Fig. 3], to lock the sliding of the gripper body 5 on the two sliding rods 4, the cylinder rod 15 then coming into abutment against the lower face of the support plate 3 and thus preventing the upward sliding of the gripper body 5 on the two sliding rods 4.

[0087] The gripper 1 is configured to activate the sliding locking cylinder 15 (i.e., deploy the cylinder rod 15) during the phases of gripping the package and moving the package towards the pallet, so as to lock and neutralize the movements of the gripper body 5 relative to the support plate 3 during the movement of the robotic arm 2 at high industrial production speeds.

[0088] On the contrary, the gripper 1 is configured to deactivate the sliding locking cylinder 15 (i.e., retract the rod of the cylinder 15) during the palletizing phase of the package, i.e. during the phases of approaching and bringing into contact with the depositing surface and during the phase of depositing the gripped package on the depositing surface.

[0089] The gripper 1 further comprises two pivoting arms 16 mounted on either side of the gripper body 5, each of the two pivoting arms 16 carrying three suction cups 17 arranged in a triangular shape.

[0090] It should be noted that each pivoting arm 16 could also carry four suction cups 17 arranged in a cross shape, without departing from the scope of the present invention.

[0091] In their deployed position, the two pivoting arms 16 carry the suction cups 17 under the two retractable blades 6 to form a horizontal suction plane for the suction cups 17.

[0092] The gripper 1 is configured to deploy the two pivoting arms 16, by by means of a gear system, so as to grasp by suction an interlayer sheet using the suction cups 17 and then place it on the last layer placed on the pallet, prior to the placement of the first package of the next layer on the pallet.

[0093] If we refer to [Fig.4], we can see that the gripper 1 is shown there after gripping a package to be palletized 19.

[0094] The package 19 is locked in position in the gripper 1 between the two blades 6 and the pressing pad 7a.

[0095] Given that the gripper 1, carried by the robotic arm 2, does not rest on any surface, the front part 5a of the gripper body 5 is positioned, by gravity, in the lower part of the two sliding rods 4, coming into abutment against stop washers 4a fixed in the lower part of the sliding rods 4.

[0096] The position sensor 13 is an inductive type proximity sensor, but could also be a laser or photoelectric type proximity sensor, without departing from the scope of the present invention.

[0097] The inductive type position sensor 13 is oriented towards the front of the gripper 1 and makes it possible to detect the presence / absence of the support plate 3 opposite the latter as a function of the sliding position of the gripper body 5 on the sliding rods 4.

[0098] In the case of [Fig.4], the support plate 3 is located at a height greater than that of the position sensor 13 and is therefore not opposite the latter, such that the inductive type position sensor 13 does not detect the support plate 3. The gripper 1 therefore does not detect any contact with the deposit surface by the gripper body 5.

[0099] If we refer to [Fig.5], we can see that the gripper 1 is shown there in contact with a deposition surface 20.

[0100] When the robotic arm 2 moves the gripper 1 so that the gripper body 5 rests on the deposition surface 20, the front part 5a of the gripper body 5 then slides upwards along the sliding rods 4, so that the support plate 3 is opposite the inductive type position sensor 13. The inductive type position sensor 13 then detects the support plate 3, and the reaching of the deposition surface 20 by the gripper body 5 is thus detected by the gripper 1.

[0101] Thus, the gripper 1 according to the present invention makes it possible to detect and inform the automation chain of the palletizing device of the altitude of the layer previously deposited in order to carry out a realignment at each layer and to follow the altitude of the pallet of bundles of magazines which are gradually compacted.

[0102] The width of the fork made up of the two horizontal blades 6 is narrow (of preferably less than or equal to 100 mm), such that the package to be palletized 19 is gripped by the gripper 1 at the middle of the package 19. Thus, when the gripper body 5 rests on the depositing surface 20 and the middle of the package 19 rests on the blades 6, the sides of the package 19 are already in contact with the depositing surface 20 due to the flexibility of the elements constituting the package 19.

[0103] If we refer to [Fig.6], we can see that the gripper 1 is shown there after depositing the package to be palletized 19 on the depositing surface 20.

[0104] As soon as the reaching of the depositing surface 20 by the gripper body 5 is detected by the gripper 1 (via the position sensor 13), the horizontal blades 6, on which the package 19 rests, are retracted inside the gripper body 5 by moving the carriage 8, so that the package 19 is deposited on the depositing surface 20 without any drop height.

[0105] The sliding sensor system of the gripper 1 thus makes it possible to place the package to be palletized 19 directly on the deposition surface 20 (such as the lower layer or the lower package on the pallet, i.e. the last layer or the last package placed on the pallet).

[0106] The sensor gripper 1 according to the present invention thus makes it possible to come into contact with the depositing surface 20 of the pallet in order to deposit the package to be palletized 19 by contact on the depositing surface 20, even if the altitude of the depositing surface 20 is unknown or known approximately by the palletizing device.

[0107] Referring to [Fig.7], it can be seen that a palletizing device 21 according to an embodiment of the present invention is shown there.

[0108] The palletizing device 21 comprises a conveyor 22 and a robotic arm 2 carrying the gripper 1 according to the present invention at its end 2a.

[0109] The palletizing device 21 is configured to grip, using the retractable horizontal blades 6 and the pressing cylinder 7 of the gripper 1, a package to be palletized 19 present at the outlet of the conveyor 22, to move, using the robotic arm 2, the gripped package to be palletized 19 to a depositing surface such as the upper surface of a pallet 23 (or the upper surface of an already palletized package, or the upper surface of an interleaf sheet), and to deposit, by retraction of the horizontal blades 6 of the gripper 1, the package to be palletized 19 directly on the pallet 23 only after detection, by the position sensor 13 of the gripper 1, of a change in position of the gripper body 5 relative to the support plate 3 of the gripper 1, indicating the presence of the pallet 23 directly under the palletized package 19.

[0110] The conveyor 22 comprises a package input module 22a, a package output module 22b and a roller package moving module 22c disposed between the package input module 22a and the package output module 22b and configured to moving palletized packages 19 (such as packages of printed matter) between the package input module 22a and the package output module 22b, the palletized packages 19 being able, for example, to come from the output of a shaping folder.

[0111] The package output module 22b has an alignment system 24 for aligning the package 19 to be picked up on its four side faces. This alignment system 24 will be described in more detail in [Fig.8].

[0112] The palletizing device 21 further comprises an electrical box (not shown in [Fig.7]) for supplying electrical energy to the conveyor 22, the robotic arm 2 and the gripper 1.

[0113] The palletizing device 21 also comprises a computer processing unit (not shown in [Fig.7]) having palletizing assistance software installed thereon, which allows the control of the conveyor 22, the robotic arm 2 and the gripper 1 for the palletizing of bundles of printed matter, notebooks, books, magazines or sheets.

[0114] The conveyor 22 carries, at one of its lateral sides, a dialogue terminal 25 (preferably touch-sensitive) which allows an operator to communicate with the palletizing device 21.

[0115] If we refer to [Fig.8], we can see that the conveyor 22 of the palletizing device 21 is represented there, at the level of its package output module 22b.

[0116] The package moving module 22c of the conveyor 22 has rollers 26, some of which are motorized to drive each package to be palletized 19 towards the package output module 22b. It should be noted that the package moving module 22c could also be a conveyor belt, without departing from the scope of the present invention.

[0117] The package output module 22b has three parallel conveyor belts 27 (driven by an electric motor 29) for moving the package to be palletized 19 to the outlet of the conveyor 22, two longitudinal notches 28 thus being formed between the three conveyor belts 27, these two longitudinal notches 28 being configured to receive the two deployed blades 6 of the gripper 1.

[0118] It should be noted that the conveyor belts 27 could also be replaced by a set of rollers in which two longitudinal notches 28 would be formed, without departing from the scope of the present invention.

[0119] The two longitudinal notches 28 thus allow the positioning of the two blades 6 deployed under a package to be palletized 19 present at the exit of the conveyor 22.

[0120] The package output module 22b of the conveyor 22 also comprises two package presence sensors 30 arranged on either side of the conveyor belts 27. The package presence sensors 30 may, for example, be photoelectric cells, the reference numerals 30a representing the detection beams of the package detection sensors 30. The detection results of the package detection sensors 30 allow the computer processing unit to detect the presence of a package to be palletized 19 at the exit of the conveyor 22 so as to control the robotic arm 2 and the gripper 1 to grasp this package to be palletized 19.

[0121] The alignment system 24 of the package output module 22b of the conveyor 22 comprises a first lateral vertical plate 31 arranged at one of the two lateral sides of the output of the conveyor 22, and a second lateral vertical plate 32 arranged at the other of the two lateral sides of the output of the conveyor 22.

[0122] The first and second vertical plates 31 and 32 are automatically movable, using plate moving cylinders driven by an electric motor 33, in the direction perpendicular to the direction of movement of the conveyor 22.

[0123] It should be noted that only one of the two vertical plates 31 and 32 could be moved automatically, without departing from the scope of the present invention.

[0124] The first vertical plate 31 carries a right-angle return serving as a stop 34 which has a height identical to that of the first vertical plate 31 and a width very reduced compared to the width of the packages to be palletized 19.

[0125] When a package 19 is present at the exit of the conveyor 22, the robotic arm 2 moves the gripper 1 so as to place the two horizontal blades 6 of the gripper 1 inside the two longitudinal notches 28, under the package to be palletized 19.

[0126] Then, the first and second vertical plates 31 and 32 of the alignment system 24 are moved until they come into abutment against the two associated lateral faces of the package 19, so that the package 19 is aligned between the first and second vertical plates 31 and 32 of the alignment system 24. The first and second vertical plates 31 and 32 thus constitute the first and second tracking faces of the alignment system 24 and allow the automatic alignment of the package 19 on two of its four lateral faces.

[0127] The gripper 1 further has a flat vertical surface 35 facing the bundle 19 such that, when the gripper 1 advances and the two deployed blades 6 of the gripper 1 penetrate further into the two longitudinal notches 28 of the conveyor 22, the vertical surface 35 of the gripper 1 pushes the bundle 19 against the flat surface of the stop 34 so as to align the bundle 19 on the other two of its four lateral faces. The vertical surface 35 of the gripper 1 and the flat surface of the stop 34 thus constitute, respectively, the third and fourth tracking faces of the alignment system 24.

[0128] Thus, the package 19 is automatically aligned on its four lateral faces. at the exit of conveyor 22.

[0129] After jogging, the bundle 19 is thus blocked by the two lateral vertical plates 31 and 32, by the vertical surface 35 of the gripper 1 and by the stop 34 whose width is limited and does not cover the entire corresponding lateral face of the bundle 19. The jogging of the bundle 19 by the two vertical plates 31 and 32 of the alignment system 24 before the advancement of the gripper 1 makes it possible to guarantee the jogging of the bundle 19 between the vertical surface 35 of the gripper 1 and the stop 34, even if the stop 34 has a very reduced width compared to that of the bundle 19. Indeed, the bundle 19 being already aligned on three of its lateral faces, a simple stop (namely, the stop 34) is sufficient for the alignment of the fourth lateral face. The fourth alignment face thus comprises a real part constituted by the stop 34 and a “virtual” part constituted by the space between the stop 34 and the second vertical plate 32 of the alignment system 24.

[0130] It should be noted that the gripper 1 could also comprise a package detection sensor such as a photoelectric cell (not shown in the figures), arranged on the gripper body 5 and configured to detect whether a package 19 is not present at the outlet of the conveyor 22, so as to trigger the four-sided alignment then the gripping of the package 19 in the event of positive detection.

[0131] The present invention makes it possible to have a palletizing device 21 with the widest possible operating spectrum on the production of packages delivered by upstream equipment such as shaping folders, in particular bulky packages with variable thickness due to the presence of air before compression by the weight of the upper layers once placed on the pallet.

[0132] It is understood that the particular embodiment which has just been described has been given for informational purposes and is not limiting, and that modifications may be made without departing from the present invention.

Claims

Claims

1. A sensor gripper (1) for a palletizing device (21), said gripper (1) being configured to be carried by a robotic arm (2) of a palletizing device (21), said gripper (1) comprising, in the lower part, at least one retractable horizontal support member and, in the upper part, a vertical pressing member configured to grip between them a package to be palletized (19), characterized in that said gripper (1) further comprises: - a support plate (3) configured to be connected to the end (2a) of the robotic arm (2); - at least one sliding rod (4) extending vertically downwards from the support plate (3); - a gripper body (5) slidably mounted on the at least one sliding rod (4) and suspended vertically relative to the support plate (3), configured to move vertically relative to the support plate (3) along the at least one sliding rod (4), said gripper body (5) carrying the at least one retractable horizontal support member and the vertical pressing member; and - a position sensor (13) carried by one of the gripper body (5) and the support plate (3), the position sensor (13) being configured to detect a change in position of the gripper body (5) relative to the support plate (3), wherein, when the lower part of the gripper body (5) comes into contact with a depositing surface (20), the gripper body (5) slides upwards along the at least one sliding rod (4), which causes a detection of a change in the relative position of the gripper body (5) and the support plate (3) by the position sensor (13), indicating the presence of the depositing surface (20) under the gripped package to be palletized (19), thus allowing the deposit of the gripped package to be palletized (19) directly on the depositing surface (20) by retraction of the at least one support member.

2. Gripper (1) according to claim 1, characterized in that the position sensor (13) is a proximity sensor of the inductive, laser or photoelectric type carried by the gripper body (5) and configured to detect the presence / absence of the support plate (3) opposite the latter as a function of the sliding position of the gripper body (5) on the at least one sliding rod (4).

3. Gripper (1) according to claim 1 or 2, characterized in that it further comprises a weight compensation system arranged between the support plate (3) and the gripper body (5) and configured to perform compensation for the weight of the gripper body (5) when empty.

4. Gripper (1) according to claim 3, characterized in that the weight compensation system is one of at least one spring (14) and at least one cylinder, arranged between the support plate (3) and the gripper body (5).

5. Gripper (1) according to claim 4, characterized in that the at least one sliding rod (3) consists of first and second parallel sliding rods on which the gripper body (5) is slidably mounted, the at least one spring (14) consisting of a first spring arranged on the side of the first sliding rod and a second spring arranged on the side of the second sliding rod.

6. Gripper (1) according to one of claims 1 to 5, characterized in that the at least one retractable horizontal support member consists of two parallel retractable horizontal blades (6) forming a fork.

7. Gripper (1) according to one of claims 1 to 6, characterized in that it further comprises a sliding locking cylinder (15) arranged on the gripper body (5) and configured to lock the sliding of the gripper body (5) on the at least one sliding rod (4), the gripper (1) being configured to activate the sliding locking cylinder (15) during the phases of gripping the package (19) and moving the package (19) and to deactivate the sliding locking cylinder (15) during the phase of palletizing the package (19).

8. Gripper (1) according to one of claims 1 to 7, characterized in that the vertical pressing member consists of at least one vertical pressing cylinder (7), optionally carrying a pressing pad (7a) opposite the at least one horizontal support member.

9. Gripper (1) according to one of claims 1 to 8, characterized in that it further comprises two pivoting arms (16) mounted on either side of the gripper body (5), each of the two pivoting arms (16) carrying at least three suction cups (17), each pivoting arm (16), in its deployed position, carrying the suction cups (17) under the at least one horizontal support member to form a horizontal suction plane for the suction cups (17), the gripper (1) being configured to deploy the two pivoting arms (16) so as to grip by suctioning an interlayer sheet using the suction cups (17).

10. Palletizing device (21), characterized in that it comprises a conveyor (22) and a robotic arm (2) carrying a gripper (1) according to one of claims 1 to 9, said palletizing device (21) being configured to grip, using the at least one retractable horizontal support member and the pressing member of the gripper (1), a package to be palletized (19) present at the outlet of the conveyor (22), to move, using the robotic arm (2), the gripped package to be palletized (19) to a depositing surface (20), and to deposit, by retraction of the at least one support member of the gripper, the package to be palletized (19) directly on the depositing surface (20) only after detection, by the position sensor (13) of the gripper (1), of a change in the relative position of the gripper body (5) and the support plate (3), indicating the presence of the deposit surface (20) under the package to be palletized (19).

11. Palletizing device (21) according to claim 10, characterized in that it further comprises, at the outlet of the conveyor (22), an alignment system (24) comprising two parallel lateral vertical plates (31, 32) arranged on either side of the outlet of the conveyor (22), at least one of the two vertical plates (31, 32) being movable, using a plate displacement cylinder, in the direction perpendicular to the direction of movement of the conveyor (22) so that the two vertical plates (31, 32) are configured to align the package to be palletized (19) on two of its four lateral faces, at least one of the two vertical plates (31, 32) carrying a vertical stop (34) which has a surface perpendicular to said vertical plate,the gripper body (5) carrying a vertical surface (35) configured to push the package to be palletized (19) against the stop (34) so ​​as to align the package to be palletized (19) on the other two of its four lateral faces.,

12. Palletizing device (21) according to claim 10 or 11, characterized in that the outlet of the conveyor (22) comprises at least one longitudinal notch (28) configured to receive the at least one deployed support member of the gripper (1).

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