Method and tool for the separation of a pile of recipients

The separation tool allows separation of a horizontal pile of recipients into sub-piles of recipients, the first or last recipient of each sub-pile have been previously marked with ultra-violet detectable ink. The tool comprises a frame; a sensor mounted to the frame for detecting the last recipient of a current sub-pile or the first recipient of the next sub-pile upstream therefrom, which ever has been previously marked, and a manipulator arm provided with a fixed finger assembly for holding the recipients upstream from the last recipient of the current sub-pile and a separation finger for creating a gap between the held recipients and those from the current sub-pile.

FIELD OF THE INVENTION

The present invention generally relates to manufacturing and handling of recipients. More specifically, the present invention is concerned with a method and tool for separation of a pile of recipients.

BACKGROUND OF THE INVENTION

The manufacturing process of Styrofoam or other types of recipients usually ends by the manufactured recipients exiting a trim press on a feed table. The recipients are then separated in groups of a predetermined number of recipients, which are then packaged for shipping. The conventional method of separating the recipients involves the steps of individuals manually counting the appropriate number of recipients on the feed table and feeding them to bags or boxes for shipping. A drawback of this conventional recipient separating method is that it is time consuming and bound to error as any other human-handled repetitive process.

OBJECTS OF THE INVENTION

An object of the present invention is therefore to provide an improved method and tool for the separation of a pile of recipients.

SUMMARY OF THE INVENTION

More specifically, in accordance with an aspect of the present invention, there is provided a separation tool for separating a pile of recipients into sub-piles of recipients, the tool comprising: a frame; a sensor mounted to the frame for detecting the last recipient of a first sub-pile or the first recipient of a second sub-pile upstream from the first sub-pile; the first recipient of the second sub-pile being the recipient adjacent the last recipient of the first sub-pile upstream therefrom; at least one manipulator arm mounted to the frame; the at least one manipulator arm including a mechanical hand assembly having a fixed finger assembly for holding one of i) the last recipient of the first sub-pile and ii) the first recipient of the second sub-pile, and a separation finger assembly for pushing the other of the one of the last recipient of the first sub-pile and the first recipient of the second sub-pile.

According to a more specific aspect of the present invention, there is provided a separation tool for separating a pile of recipients into sub-piles of recipients, the tool comprising: a frame; a sensor mounted to the frame for detecting a marked recipient; the marked recipient having an adjacent recipient; at least one manipulator arm mounted to the frame; the at least one manipulator arm including a) a mechanical hand assembly having a fixed finger assembly for holding one of the marked recipient and the adjacent recipient, and b) a separation finger assembly for pushing the other of one of the marked recipient and the adjacent recipient away from the one of the marked recipient and the adjacent recipient.

A separation tool according to the present invention allows providing for both a faster and more efficient recipient separation process.

According to a further aspect of the present invention, there is provided a method for separating a pile of recipients into sub-piles of recipients, the method comprising: i) considering the first recipient of the pile of recipients as the first recipient of a current sub-pile of recipients; ii) searching the last recipient of the current sub-pile and the first recipient of a following sub-pile; the first recipient of the following sub-pile being the recipient adjacent the last recipient of the current sub-pile upstream therefrom relatively to the first recipient of the sub-pile; iii) holding one of the last recipient of the current sub-pile and the first recipient of the following sub-pile; and iv) pushing the other of the one of the last recipient of the current sub-pile and the first recipient of the following sub-pile away from the one of the last recipient of the current sub-pile and the first recipient of the following sub-pile, yielding a separating gap between the first sub-pile and the following sub-pile.

Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of preferred embodiments thereof, given by way of examples only with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

A robot separation tool10for separating a horizontal pile of recipients into sub-piles of recipients according to an illustrative embodiment of a first aspect of the present invention will now be described with reference toFIGS. 1 to 5.

The tool10includes two symmetrically identical manipulator arms12mounted on a frame14, each provided with a marked-recipient detector in the form of a ultra-violet (UV) sensor16.

The frame14includes a manipulator arm mounting plate18, two manipulator arm receiving members20mounted to the mounting plate18via two horizontal parallel rails22so as to be slidable along the width of the mounting plate18, two vertical mounting rails24, and two horizontal mounting rails26, each secured to a respective vertical mounting rail24via a securing plate28(seeFIG. 5), yielding a generally L-shaped member30. One skilled in the art will easily understand that movements along three axes are therefore possible.

As will become more apparent in the following, the frame14should be construed as any parts of the tool10bringing either support thereto or allowing mounting other parts or components thereto. Moreover, the frame14can be modified to receive more or less than two manipulator arms.

The manipulator arm mounting plate18is secured to a conventional robot arm31, such as model IRB 640 from ABB, via a tool-mounting bracket32. The manipulator arm31, which is illustrated in dashed lines, allows positioning and moving of the tool10over the pile of recipients33. Of course, the manipulator arm31may have any configuration allowing for the positioning and moving of the tool10as will be described herein in more detail.

The tool-mounting bracket32includes brackets or other mounting means for receiving from the robot arm31power supply for the operation of the tool10, including electrical and/or pneumatic supply.

As it is conventionally known in the art, the robot's controller (not shown) provides the control of the tool10.

Since robot arms and tool controls are believed to be well known in the art they will not be described herein in more detail.

The manipulator arm mounting plate18is provided with means34for receiving the input block and the valve terminal. Such means can be in the form of the illustrated track34, but can of course take other forms.

The manipulator arm mounting plate18also includes two elongated slots36, each one for receiving one of the two locking cursors38, each mounted to a respective manipulator arm receiving member20near the side thereof. The locking cursors38allow setting the position and then preventing any displacement of the member20along the rails22. Indeed, each manipulator arm receiving member20is in turn mounted to the rails20via two blocks40, each provided with a groove so configured and sized as to be complementary to the rail22, so that the rail22are received therein. Rules42are provided on the mounting plate18to help in the positioning of the manipulator arm12along the mounting plate18. For that purpose, an indicator, in the form of a thin plate44, is secured on the edge of the manipulator arm-receiving member20and indicates on the rule42the position of the arm12. Of course, the rules42and indicator44have to be properly positioned and configured in order to provide for precise readings.

Of course, the manipulator arm-receiving members20can have other configuration allowing the manipulator arms12to be mounted to the robot arm32via the mounting plate18. Also, the indicator system can take other forms such as a digital readout (not shown), allowing the adequate positioning of the manipulator arm for specific dimensions and positions or recipients for example.

A handle46secured to each vertical mounting rail24at the level of the manipulator arm mounting plate18helps the manual sliding and positioning the corresponding manipulator arm12along the rails22.

The manipulator arm12will now be described. It is to be noted that the two manipulator arms12are symmetrically identical. For such reason and for concision purpose, only one of the two manipulator arms12will be described herein. However, for clarity purposes, the reference numerals will be positioned on either of the arms12. As will be explained hereinbelow, the number of manipulator arms12may vary from one to many. Of course, the manipulator arm mounting bracket32and manipulator arm mounting plate18are configured for receiving the number of manipulator arms12required by the specific application.

The manipulator arm12comprises a mechanical hand assembly48including a fixed finger assembly50, a separation finger assembly52and a separation finger assembly course limiter54.

The mechanical hand assembly48includes a mounting plate56slidably mounted to the horizontal rail26. More specifically, the mounting plate56includes an elongated protrusion58that is snapfitted to the rail26(seeFIG. 2).

The fixed finger assembly50is said to be fixed so as to be distinguishable from the separation finger assembly52, since contrarily to the separation finger assembly52, it cannot reciprocate along an axis parallel to the mounting plate56. However, similarly to the separation finger assembly52and as will now be described in more detail, the fixed finger assembly50is mounted to the plate56so as to reciprocate towards to and away from a pile of recipients33. The fixed finger assembly50comprises a linear actuator in the form of a guided drive60that can be of the DFM type from Festo and having a cylinder64and a contact plate62secured thereto. The guided drive60is secured to the mounting plate56on the inner surface thereof. Of course, other types of linear actuators can alternatively be used.

The contact plate62includes an extending portion66that extends sideways from the cylinder64. The extending portion66of the bottom surface of the contact plate62is provided with a linear grip70extending from the contact plate62in a direction away from the cylinder64of the guided drive60and located along the front edge of the extending portion66.

Alternatively, the fixed finger50can have other configuration allowing holding either the last recipient of a sub-pile or the first recipient of the following sub-pile.

The separation finger assembly52comprises a first guided drive72mounted to the mounting plate56so as to be operable in a horizontal plane, a second guided drive75mounted to the contact plate74of the guided drive72so as to be operable in a vertical plane while being movable as a whole in a horizontal plane. More specifically, the second guided drive75is mounted to the contact plate74of the first guided drive72through a small elongated plate76so fastened to the contact plate74and so configured as to position the second guided drive75so that its cylinder78is generally levelled with the cylinder64of the guided drive60. A contact plate80, provided with a friction pad82is secured to the cylinder78of the second guided drive75. The mounting of the second guided drive75to the cylinder of the first guided drive72perpendicularly thereof allows the cylinder78to reciprocate between a retracted position and an extended position along a range of orientations comprised between the respective orientation of the guided drives72and75.

Alternatively to the above-described configuration, the separation finger52according to the illustrative embodiment can be replaced by other means allowing to push one of the last recipients of the current sub-pile and the first recipient of the next sub-pile away from the other, so as to yield a separation gap between the first sub-pile and the following sub-pile

The separation finger assembly course limiter54allows setting the maximum separation overture, as defined by the gap between the linear grip70and the edge84of the friction pad82nearest the fixed finger50.

The separation finger course limiter54is in the form of a mechanical stop86provided at the distal end88of a threaded rod90inserted in an internally threaded cube92fastened to the mounting plate56below the guided drive72. The free end of the threaded rod90is provided with a knob94. A locking handle96allows locking the axial position of the mechanical stop86. A marker98fixedly mounted to contact plate74and/or second guided drive75, allows indicating on a rule100the displacement of the separation finger assembly52along the operating direction of the first guided drive72.

Each UV sensor16is secured to a respective manipulator guided drive60of the fixed finger assembly50via an elongated bracket member102. The elongated member102is provided with a longitudinal slit104configured and sized to receive a screw (not shown) secured to the casing105of the UV sensor. The elongated member102is fixedly mounted to the guided drive60via screws or other fastening means so as to be oriented generally perpendicular to the operating orientation of the cylinder64thereof. A rule106is provided on the surface of the member102, opposite the sensor16parallel to the slit104, allowing for a precise positioning of the sensor16.

The sensor16can be, for example, a model LUT3-650 from SICK. The sensor16allows detecting marks on recipients made using UV detectable ink. Of course, other types of sensors may alternatively be configured to detect other types of markings.

The manipulator arm12further comprises a spatula assembly108including a spatula mounting plate110mounted to the L-shaped member30, a rodless cylinder112secured to the mounting plate110so as to extend along downwardly thereof and a spatula114, in the form of an elongated plate, slidably mounted to the rodless cylinder112generally parallel thereof.

The spatula mounting plate110is pivotally mounted to the vertical mounting rail24of the L-shaped member30via a mounting bracket116having a pivot pin118fixedly mounted to the mounting plate110near its higher longitudinal end120.

The spatula114is slidably mounted to the rodless cylinder112via the carriage150of the rodless cylinder112.

Since rodeless assemblies112are believe to be well known in the art, they will not be described herein in more detail.

The spatula114is fastened to the carriage150.

The spatula assembly108further comprises a spatula sensor160mounted to the bottom portion of the beam112. The spatula sensor is in the form of a photocell. The spatula sensor160is positioned adjacent the spatula114to detect if the path of the spatula114is free of any obstacle.

A spatula stroke limiter, in the form of a resilient piece of metal162is secured to one side of the beam112so as to be within the path of the carriage152and more specifically to be abutted by one of the two opposite side portions154-156so as to limit the downward stroke thereof.

The spatula assembly108can have other configurations allowing a spatula to be mounted to the manipulator arm12so as to be movable between a retracted and an extended position between the fixed and separation finger assembly50-52.

A spatula angle setter122(seeFIG. 4) mounted to both the horizontal rail26of the L-shaped member30and to the lower longitudinal end124of the mounting plate110allows adjusting the tilt angle of the spatula assembly108.

As better seen inFIG. 5, the spatula angle setter122comprises a cylinder126whose distal end is pivotally mounted to a pivot pin128that is fixedly mounted to a mounting bracket130, which is, in turn, secured to the mounting plate110near the lower longitudinal end124thereof. The proximate end of the cylinder126is pivotally mounted to a small carriage132via a pivot pin134secured thereto. The carriage132is mounted to the horizontal mounting rail26so as to be slidably movable thereon. A locking mechanism136on the carriage132allows selectively preventing any movement of the carriage132along the horizontal mounting rail26.

A threaded rod138operable through a knob140is mounted to both rails26and the carriage132and allows adjusting the longitudinal position of the carriage132along the rail26. An indicating cursor142fastened or integral to the carriage132allows indicating on the rule144the angle of the spatula114relatively to the horizontal rail26. Of course the rule is so configured and positioned along the rail as to provide representative readings indicative of the angle of the spatula.

Before operation of the tool10, the angle of the spatula114is adjusted relative to the horizontal rail26by rotating the knob140. Rotation of the knob140, and therefore of the threaded rod138, in a first direction causes the carriage132to be pushed along the rail26, which in turn causes the cylinder to push on the lower longitudinal end124of the mounting plate110(see arrow146onFIG. 5), biasing the lower end of the spatula114away from the knob140(see arrow148onFIG. 5). Obviously, rotation of the knob140in the opposite direction causes the lower end of the spatula114to be tilted in the opposite direction.

The spatula angle setter122can of course have other configurations. Also, the orientation of the spatula114can be permanently set.

Each of the two manipulator arms12finally includes a start-of-pile detector164(FIG. 2) mounted to the bracket member102near the proximate end thereof. The start-of-pile detector164is in the form, for example, of an optical detector, model WT4-2P331 by SICK.

The operation of the tool10and more specifically of each of the two manipulator arms12will now be described with reference toFIGS. 4-11and according to a method200for separating a pile of recipients into sub-piles of recipients according to an illustrative embodiment of a second aspect of the present invention as illustrated inFIG. 12.

In the illustrated example, the recipients35are brought on a feed table (not illustrated) in parallel pairs of parallel adjacent piles33(only one pair illustrated). The separation tool10allows covering the entire width of the table and the length of its stationary portion. Since the tool10includes two manipulator arms12, it can be used to simultaneously separate two adjacent piles33. Of course, providing the tool10with a different number of manipulator arms would allow the tool10to simultaneously separate any number of parallel piles.

The separation tool10allows i) the detection of the position of separation in each of the pair of pile33, yielding two adjacent sub-piles of a predetermined length, ii) the separation of each sub-pile of recipients from the remaining of the corresponding pile, and iii) holding the pair of sub-piles of recipients while they are pushed away from the remaining of the piles.

A method for separating a pile of recipients into sub-piles of recipients according to an aspect of the present invention includes the following steps:considering the first recipient of the pile of recipients as the first recipient of a current sub-pile of recipients;searching a marked recipient of the current sub-pilethe recipient following the marked recipient being the first recipient of the following sub-pile and needing to be separated from the marked recipient;holding the marked recipient; andpushing the first recipient of the following sub-pile away from the marked recipient, yielding a separating gap between the first sub-pile and following sub-pile.

Of course, the marked recipient could be the first recipient of the following sub-pile instead of the last recipient of the current sub-pile.

It is to be noted that the separation tool10may be so configured as to separate different sizes of recipients. Indeed, the tool10is made adjustable for recipients of different geometries. Such adjustments include for example:the distance between the two (or more) symmetrically identical arm12;the separation gap between the fixed and separation fingers50and52;the pressure applied by the fixed and separation fingers50and52onto the recipients;the course of the spatula114; andthe tilt of the spatula114relatively to the frame.

Turning now more specifically toFIG. 12, the first step (202) of the separation method200is the tool10verifying the state of the feed table before separating piles. The verification includes assessing whether there are sufficient recipients35for separation in at least one of the piles33.

More specifically, when a detector (not shown) from the feed table and coupled to the robot controller (not shown) detects a high level on the feed table, the tool10moves to the high level portion of the table and scans all the piles to verify their respective level. The tool10will proceed with the separation of the first pile for which a high level is detected, unless, for some reason, it is prevented by the PLC (programmable logic controller), which controls the whole manufacturing process, from separating this specific pile. In this last case, the tool10continues its scan and proceeds with the separation of the next piles showing a high level and for which the separation is allowed by the PLC. After the separation of this pile (or pair of piles according to the present example), the tool10will proceed with the separation of the next adjacent pile (or the next adjacent pair of piles). Of course, the PLC and robot controller can be replaced by any other type of controllers.

If the low level detector (not shown) informs the robot31that no pile has reached the minimum level, the robot31is put in an idle state until the minimum level is detected.

The robot arm searches for the longest column to remove the exceeding recipients. When a high level is detected, the tool10is moved by the robot arm31at the start of piles (step204).

The tool10is then moved upstream in search of a UV-detectable mark167(schematically illustrated as an inverted U-shaped element on the figures) on a recipient33(step206). For that purpose, the tool10is translated along the first pile33towards the feeding direction (see arrow166inFIG. 4) until the UV sensor16detects a UV-detectable mark167on the upper side of a recipient35(step207). Of course, the mark167has been added during the recipient manufacturing process using UV detectable chemical ink or a substance that is invisible at normal light. Readings are simultaneously considered from both UV sensors16so as detect a first mark on any one of the two piles.

Of course, paint, ink or other substances yielding visible markings at normal light can also alternatively be used. In that later case however, the sensor16is of course configured to detect such markings. The mark167is provided, during the recipient manufacturing process, every n recipients, n being the desired number of recipients35to be comprised in a sub-pile. Of course, the mark167can be provided at the end or at the beginning thereof. The tool10is programmed accordingly to yield the desired result, i.e. using the manipulator arm12to create an opening (a gap) in the pile33between the last recipient of a first sub-pile and the first recipient of the next sub-pile, as will be described hereinbelow. For such reason, the relative displacement of the recipient35and of the tool10, and the relative position of the fixed and separation fingers50-52towards the direction of displacement of the tool10can be modified as long as the tool is controlled accordingly.

When a UV-detectable mark167is detected, the robot31stops and memorizes the position of the mark167and which one of the two piles has the mark167(step208).

The robot31then positions the tool10from a predetermined distance downstream from the position of the first detected mark along the pair of piles (step210) and repeats steps206-208for the other pile of the pair.

When no UV-detectable mark167is detected for either one of the two piles of the pair, the robot31moves to the next adjacent pair of piles (step211) and repeat steps204-210.

The separation positions, as detected by the sensors16, are corrected to compensate for the displacement of the recipients33along the feed table. The separation position is computed, for example, as follows: the time delay since the detection of the mark167times the recipient feeding speed times the gap between two adjacent recipients33.

In step214, the tool is moved at the memorized separation position of the pile where the mark has been detected further upstream between the two piles from the pair.

As illustrated inFIG. 7, the guided drives60and75of the fixed finger50and then the separation finger52are actuated (steps216and218) so that their respective contact plates62or74abuts the pile33. Of course the tool10has been positioned at the appropriate distance from the pile33by the robot arm31. While in this configuration, which is illustrated inFIG. 7, the fixed finger50holds the recipients from the next sub-pile, the grip70being positioned between the first recipient of the next pile and the last recipient of the current pile.

Then, in step220, which is illustrated inFIGS. 8 and 9, the guided drive72is energized, causing the separation finger assembly52to move downstream (see arrow170inFIG. 8) thereby pushing the recipients of the current pile away from the recipients held by the fixed finger assembly50.

The spatula sensor160is then triggered to assess whether or not the projected path of the spatula114is unobstructed (step222). The sensor beam, of the spatula sensor160is represented by the dashed line172on bothFIGS. 8-9. If the path is obstructed then i) the separation finger assembly52is retracted (step226) and ii) verification is performed as to whether a predetermined number of separation trials have been reached (step228). If this is true then the method200returns to step211. If not, then the method returns to step218. The predetermined number of trails can be, for example, three (3).

If the path is unobstructed then the spatula114is moved downwardly (step224) as illustrated inFIG. 10(see arrow174).

The separation finger assembly52is then moved to its retracted position (step230, see arrow178onFIG. 11).

Steps214-220are then repeated for the other pile of the pair (step232).

The spatula angle setters122are then actuated (step234), resulting in the tilting of both spatulas114so as to allow the spatula114to push on the recipients from the two adjacent separated sub-piles with two contact points on each recipient.

The robot arm31is then moved so as to push of both pair of separated sub-piles, yielding a gap between each of two separated sub-piles and the corresponding remaining piles (step236).

The method200then proceeds with the separation of the next adjacent pair of piles.

Even though the present invention has been described with reference to generally rectangular recipients35, it can be adapted to separate piles of recipients having other configuration. Moreover, adjusting the angle of the spatula114allows accommodating the tool10for recipients of different depth.

It is to be noted that even though the expressions “horizontal” and “vertical” have been used herein, the tool and method described and claimed herein could operate properly when positioned at different angles.