EP1940719A1

EP1940719A1 - Methods and apparatus for automatic object handling

Info

Publication number: EP1940719A1
Application number: EP05798970A
Authority: EP
Inventors: Anton Vasile Ionescu
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-09-26
Filing date: 2005-09-26
Publication date: 2008-07-09
Also published as: EP1940719A4; WO2007040491A1

Abstract

A method for vertically loading/unloading similar objects (15) to/from a horizontal tray of a processing unit, wherein the object is inclined towards the object processing equipment during the vertical travel and glides into the tray to a final horizontal position, may be carried out using an object handling apparatus comprising an original pickup device having a guiding element (6) contacting the object and radially gliding pierced grippers (9) crossed by curved arms attached to an axially moving actuator (4).

Description

Method and apparatus for automatic object handling

Technical Field

The invention relates to automated devices, equipment and methods for handling objects, with emphasis to applications where information-storage medium objects such as compact discs are to be automatically handled in order to be processed.

Background Art

Many technologies require objects to be automatically and repetitively transported to/from specified locations in order to be processed. Some relevant pick-up devices and specialized equipment for handling objects, related with the invention disclosed here, are referenced in the patent list included, with emphasis to CD/DVD handling systems.

References Cited, U.S. Patent Documents

4253695 Mar., 1981 Blaive et al. 294/95;294/86.25;294/110.1

4411576 Oct., 1983 Smith et al. 414/225.

5165340 Nov., 1992 Karlyn et al. 101/126.

5275424 Jan., 1994 Watanabe 279/2.

5503446 Apr., 1996 De Jong 2,94/94.

5698030 Dec, 1997 Rubenchik 118/500.

5797639 Aug., 1998 Zorzenon 294/110.1 ;294.112

5873692 Feb., 1999 Costas.

5897153 Apr., 1999 Philipps 294/93,294/95

5946216 Aug., 1999 Hollerich 364/478.

5997204 Dec, 1999 Ducrocq

6111847 Aug., 2000 Assadian 369/36.

6220640 Apr. ,2001 Jensen 294/93,294/100

6257636 JuI., 2001 Hovis. 294.110.1 ;294/82.32;294/116

6321649 Nov. ,2001 Vangen 101/35; 101/4; 206/307; 206/308.1

6532198 Mar., 2003 Miller

6547296 Apr, 2003 Perkitny et al. 294/16;294/28;294/110.1

1 1/090,482 26 Mar 2005 lonescu Pending application, unpublished Various solutions are used for engaging/disengaging the objects to be transported: vacuum driven suction devices (US Pat.no 6141298), protruding grippers attempting to grasp the object from beneath (US Pat.no 5275424, 5503446, 5897153, 5946216, 6220640) or, for bored objects, friction grippers pushed against the inner wall of the hole of the object (US Pat.no 5873692, 6111847). Most known solutions require means for transporting the pick-up device against the object holder and, respectively, separate means for actuating the gripper in order to engage or disengage the object. Regularly the transport arm has to carry not only the pickup device but its electro-mechanical actuators and associated sensors, too, along a large rigid frame or shaft, exceeding the height of the object stacks (US Pat.no 5698030, 5873692, 5914918, 5946216, 6111847, 6141298, 6321649, 6532198). The higher the object stacks are, the bigger and more expensive the automated handling equipment. Due to the lack of flexibility in transporting and positioning the picker against the object holder, associated with the rigid catch of the object, most known solutions encounter picking errors, like dropping the object during transport or simultaneously engaging two objects.

Automated grippers eliminate the need for a vertical traveling transporting arm and actuators (US Pat.no. 5797639, 6257636, 4253695). However, existing solutions are either too complex or inappropriate for applications where high precision is needed in order to separate thin stacked objects, such as CD/DVD. A simpler automatic pickup device is needed, preferably able to grip the object from beneath in order to secure it during transport.

Currently many CD/DVD processing equipment does not allow a horizontal disk to be vertically placed directly into the tray of their processing units, a part of the circular disk holder being masked by the front cover of the equipment (Fig 6A). There haven't been any methods and/or handling devices previously known allowing automatic loading/unloading of disks into such equipment.

Disclosure of the invention

The present invention attempts to solve the problems mentioned above, disclosing an object handling method and corresponding object handling apparatuses for carrying it out, wherein the disk is inclined toward the processing equipment when lifted from its horizontal tray by the vertically moving pickup device, maintain its inclined position during its vertical travel and glides into the tray from its inclined position to a final horizontal position when vertically delivered by the pickup device into the tray. This way, even though the pickup device conveniently travels vertically, the object trajectory avoids the protrusion that otherwise would obstruct the vertical travel of the object, allowing automatic loading/unloading objects into such processing equipment (Fig 5, Fig 6A₁B). The method may also be used in other applications, with different objects, whenever a similar vertical object delivery problem might be encountered.

The apparatus for carrying out the claimed object handling method uses a specialized object pickup device allowing the object to incline towards the processing equipment to a pre-determined angle when vertically lifted from the horizontal tray and respectively allowing it to glide back to the horizontal holder when vertically lowered into the tray. The pickup device is vertically lifted/lowered from/to object holders (object stacks or object processing units, trays, etc) along its central axis and comprises a guiding element with a stopping shoulder enabling self adjustment to an optimal position when placed against the object. Once an object engaged, the shape of the guiding element allows the disk to rotate and prevent it from falling.

A new solution for gripping the object is disclosed: pierced gripping blades housed inside the guiding element are penetrated by thin curved arms rigidly attached to an actuator, connected to the external transport means, axially moving with respect to the guiding element within a short travel range. The arms are axially moving together with the actuator and glide through the holes of the gripping blades, forcing the protrusive grippers to radially glide out their housing engaging the object or respectively retract inside the guiding element releasing the object, accordingly with the pickup device status. These features allow error free operation of the pickup device and a single external action performed for both axial transport of the pickup device and actuating the grippers. When appropriate, the grippers may glide under the object, supporting it from beneath. This way the object is secured during transport and the arms are relieved from tension, the burden being supported by the gripping blades.

The disclosed pickup device can work automatically, being able to alternately switch between object engaging/disengaging statuses by itself, using a previously known self contained switching mechanism, automatically triggered each time the device reaches an end-of-travel position to an object holder. There is a single external axial movement performed for both transporting the pickup device towards the object holder and engaging/disengaging the object, thus simplifying the automation equipment and decreasing its cost.

Unlike previously known automatic grippers, the pickup device disclosed herein is meant to use a regular switching mechanism like the ones used by retractable ball-point pens, rather than a customized, dedicated one. A simple two components mechanism is being used, like, for example, the one described in US Pat.no.5997204. Consequently the entire construction is simplified. One component of the switching mechanism is rigidly attached to the actuator so they axially move together when driven by the transport means. The second component of the switching mechanism is attached to the guiding element by a retaining pin and allowed to spin around the common axis, but not to move away axially.

Unlike some other known automatic grippers (i.e. US Pat.no. 6257636), the gripping blades herein are secured to the said guiding element in contact with the object and, when engaging the object, the grippers are actuated before the said guiding element starts moving. This feature enables gripping precision, important especially when working with stacked objects that have to be separated.

Whenever appropriate, the hanging picker can be vertically ascended and descended using flexible means, like thread, wire, flexible ribbon or tape. This way there is no need neither for a vertical traveling supporting arm, nor for a frame or a vertical shaft for the picker to travel along. The object handling apparatus becomes very simple and small, allowing though long vertical travel for the picker, said large automated processing capacity.

A wide variety of CD/DVD processing equipments could be automated by such a versatile apparatus placed above the said master equipment, where the disks are vertically stacked and delivered to/from retainers located under the surface supporting the apparatus and accessed from above. One possible embodiment is shown in Fig 7. Depending on the amount of disks to be processed, the user can choose the number and the positions of the disk retainers to be used during each automated processing cycle.

Brief Description of the Drawings

FIG 1A-C are perspective views of prior art switching mechanism in different statuses FIG 2 is a cross-section view of the pickup device placed against the stacked objects FIG 3 is a cross-section view of the pickup device in object-disengaged status

FIG 4A-B are cross-section views of the guiding element along the gripper's housing plane, two embodiments

FIG 5 is a cross-section view of the pickup device in object-engaged status, disk inclined embodiment

FIG 6A-B are schematically views of a processing unit with a tray having partially masked object holding area and of the trajectory of an inclined object being vertically transported to/from such a tray, according with the claimed method

FIG 7 is a perspective view of one possible embodiment of an apparatus

FIG 8 is a cross-section view of the pickup device in object-engaged status, horizontal disk embodiment

Best Mode for Carrying Out the Invention

Automated CD/DVD processing applications may take immediate advantage of the claimed invention, even though it might find various other industrial applications. For ease of the description the various handled objects will be referred herein as "disks". For simplicity, in the preferred embodiment described, the object holders are horizontal, the disks are vertically stacked and the pickup device moves vertically along the axis of the object holder in order to engage or disengage a disk, being subsequently transported above a different location.

Currently many CD/DVD processing equipment does not allow a horizontal disk to be vertically placed directly into the trays 18 of their processing units, a part of the circular disk holder area being masked by the front cover 19 of the equipment (Fig 6A). If the disk is inclined towards the processing equipment during vertical travel along the central axis of the circular disk holder of such a tray, it may be transported to/from and delivered into the tray without interfering with the said front cover masking 19, as shown in Fig 6B.

The embodiment of the pickup device shown in Fig 5 can deliver a disk to/from such a tray 18 as follows: the gripping blade 9 hooks the disk asymmetrically, from the part opposite to the equipment. When lifted, the disk inclines towards the processing equipment up to the desired angle, about 45 degrees, when it reaches the stopping shoulder 17 on the guiding element 6. The shape of the guiding element itself is important since it has to allow the disk to rotate freely, preventing it from falling, too. The transport means 12 must not allow the pickup device to spin around its axis, so the disk maintains its inclined position towards the equipment during its vertical travel. When the disk is vertically descended in order to be released into the tray 18, its lower edge glides into the tray and the disk rotates from its inclined position to the final horizontal position, as shown in Fig 6B.

For simplicity, the apparatus and the pickup device described hereunder will include all the claimed features. The pickup device is automatic and does not require any additional external actuation for gripping the object, being able to alternately switch between object engaging/disengaging statuses by itself, by means of a self contained switching mechanism, automatically triggered each time the device reaches an end-of-travel position to an object holder.

Many types of previously known switching mechanisms can be used, like the ones used by retractable ball-point pens or some push-button electric switches. For simplicity, the pickup device disclosed herein uses a mechanism like the one described in US Pat no 5997204. Its functioning is only briefly described here, in order to ease further description of the pickup device itself. The switching mechanism (Fig 1A-C) comprises two parts: a cylindrical pin 2 having two pairs of diametrically opposed protruding ribs 3 and a cylindrical ring 1 comprising grooves and saw-teething on its inner surface (not shown). Considering the mechanism positioned vertically and pin 2 allowed to rotate, when the ring 1 is axially moved upwards along the central pin 2, the ribs glide on the inclined surface of the teeth, the pin rotates and the ring stops like shown in Fig 1 A, when the upper ribs 3 reach the deepest points of the current saw-teeth grooves, so the ring grips the pin. This position will determine a "disk engaged status" within the further description of the pickup device. Afterwards, when the ring 1 is axially moved downwards to the opposite direction, the other pair of ribs glides on the saw-teething on the other side of the ring, the pin rotates and the ring stops as shown in Fig 1 B, when the ribs reach the deepest points of the current saw-teeth. We will refer it as a "switching position". When subsequently the ring is moved upwards again, the process repeats, but the ring will grip the pin and stop after a shorter vertical travel, as shown in Fig 1C, due to the different shape of the corresponding saw-teeth. This position will determine a "disk disengaged status" within the further description of the pickup device. Each reaching of a "switching position", will determine subsequent change of status for the picking device: always a "disk engaged status" will be followed by a "disk disengaged status" and vice versa. A guiding element 6 having a stopping shoulder 7 enable the picking device to self adjust its position to an optimum when placed against the object, like shown in Fig 2. A central pin 5 connects the guiding element with the pin 2, component of the switching mechanism, allowing pin 2 to spin around the common central axis.

The actuator 4 attached to the external axial movement means 12, by which the entire pickup device is transported, comprises a central cylindrical bore that houses the ring 1 , component of the switching mechanism. The ring 1 is rigidly attached to the actuator 4.

Each time the guiding element 6 stops on an object holder, the actuator 4 continues its axial movement until eventually gets closest to the guiding element, when the mechanism reaches its switching position. When the transport means 12 pulls 4 away from 6, the distance the two elements can get apart, before element 6 starts moving along with 4, depends on the current status of the switching mechanism and alternates between a short and a long travel. This feature allows the picking device to alternate between object- engaging and object-disengaging statuses, the gripping means being actuated by the element 4 moving with respect to 6. When the pickup device engages the object, the upward movement of the guiding element is subsequent to the gripping process; the gripping blades, secured to the guiding element in contact with the object, protrude and engage the object before the said element starts its own movement. This feature enables gripping precision, important especially when working with stacked objects that have to be separated.

For the preferred embodiments described herein, the axial distance between the stopping shoulder 7 and the sharp edges of the gripping blades 9 housed inside the recess 16 is slightly bigger than the thickness of the disk 15, allowing the protruding blades 9 to grasp the disk from beneath when actuated.

The gripping blades 9 comprise holes 10 for the thin curved arms 8, rigidly attached to the element 4, to cross through. The guiding element 6 has thin radial ditches 11 allowing the arms 8 to travel freely when the element 4 is axially moving against the guiding element. An optional dust-protective frame 14 may be rigidly attached to the guiding element 6, provided that it allows room for the element 4 to move axially with respect to the guiding element within its entire travel range. The optional frame 14 should comprise a hole 13 on its top, opposite to the guiding element, for the transport means 12 to cross through. When the element 4 is axially pulled away from the guiding element by 12, the arms 8 glide along the ditches 11 and through the holes 10 of the pierced blades 9 and, if the switching mechanism allows element 4 to rise enough, namely the pickup mechanism is in "disk engaged status", they push the grippers 9 to glide out their housing 16, then the guiding element 6 starts moving together with element 4, that is the entire pickup device 21 is being moved by 12.

Suppose the picking device placed against a stack of disks as shown in Fig 2, with the shoulder 7 laying on the top disk. The element 4 is in its closest position to the guiding element 6 and the arms 8 keep the gripping blades 9 completely retracted inside their recess 16. The mechanism is in "switching position", like in Fig 1 B. Furthermore, suppose the picking device was in "disk disengaging status" when placed against the stack, so we expect it to engage the disk next time when lifted from the stack. When the transport means 12 axially pulls element 4 away from the guiding element 6 resting on the disk beneath, the arms 8 glide through the holes 10 of the pierced blades 9 and push them to glide out of the guiding element, their sharp edges protruding under the first disk in stack. Then the guiding element 6 starts moving together with the element 4, namely the entire pickup device 21 is lifted by 12, carrying away the disk 15 so engaged, as shown in Fig 5. The section views in Fig 4A and Fig 4B show the radial movement of the blades in two possible embodiments, with a single gripping blade and respectively with more gripping blades. Fig 8 shows such a multiple gripping blades embodiment of the pickup device in "disk engaged status", where the disk keeps its horizontal position during transport.

Suppose now the apparatus carries the pickup device with the disk so engaged in order to be released to a new location. The transport means 12 vertically lowers the pickup device on location and, when the disk reaches the holder, the guiding element 6, with its shoulder

7 laying on the disk, stops. The actuator 4 continues its movement, approaching the guiding element. The arms 8 glide through the holes 10 of the pierced blades 9 forcing them to retract completely inside the guiding element 6. The movement stops when the element 4 reaches its lowest position, closest to the guiding element, when the pickup device is in "switching position", as shown in Fig 2.

Next lift will find the pickup device in "disk disengaged status", so the mechanism will determine the element 4 to grip the guiding element 6 after a short travel, before the arms

8 start pushing the grippers 9 out, so the gripping blades will not protrude out of the guiding element, therefore the pickup device 21 , lifted by 12, will leave unloaded as shown in Fig 3 and the disk will remain in its holder.

The cycle is permanently repeated, the pickup device alternating between disk engaging/disk disengaging statuses each time it reaches the down-end-of-travel position to an object holder.

In the particular embodiment described, where the pickup device moves vertically towards the disk holder in order to engage or disengage a disk, the device can hang gravitationally, being ascended/descended using flexible means 12 like thread, wire, flexible ribbon or tape. Such a solution dramatically simplifies the automation equipment, since there is no need neither for a vertical traveling arm, nor for a frame or a vertical shaft for the picker to travel along. Moreover, long vertical travel for the pickup device, namely large capacity for the disk handling apparatus can be achieved, even though the apparatus itself is small and basically flat, the transporting flexible wire 12 being simply coiled on a reel inside the apparatus and guided out on a pulley attached to the horizontally moving part of the apparatus. The pickup device 21 is lifted up to its highest position where a basically cylindrical holder under the pulley houses it, keeping its vertical position and preventing it from waggling during the horizontal movement from a disk holder to another. The apparatus should be positioned in such a way that it can access from above the disk holders, namely the trays of the disk processing equipment and the stacks for processed/unprocessed disks.

A possible embodiment is shown in Fig 7, where the apparatus 22 is placed over a disk processing master equipment 20, comprising processing units 25, provided with trays 18. Requests for disk changing are correspondingly sent to the apparatus by the master equipment whenever needed, for example via RS232 interface. Disk retainers 24 for the disk stacks are placed on the table, around the master equipment served by the apparatus. The apparatus may comprise a keyboard 23 for interfacing with the human operator. Depending on the number of disks to be processed, the user can choose the number and the positions of the disk retainers 24 to be used during each automated processing cycle. Once the configuration selected, the user have to place the disk retainers on the table, precisely at the locations further accessed by the apparatus.

Claims

ClaimsWhat is claimed is:

1. A method (Figδ) for vertically loading/unloading similar objects (15) to/from a horizontal tray (18) of an object processing unit (25), characterized in that the said object is determined:

to incline towards the processing equipment (20) when vertically lifted from the said tray

to maintain its inclined position towards the processing equipment (20) during the vertical travel to/from such a horizontal tray (18) of the said unit

to glide into the tray (18) from its inclined position to a final horizontal position when vertically delivered into the mentioned horizontal tray

2. An object handling apparatus for carrying out the object handling method of claim 1 comprising an object pickup device (Fig5) and means for transporting the said device from an object holder to another (18,24), at least one object holder (18) belonging to an object processing unit (25), wherein the said device is vertically lifted/lowered from/to the said holders along its central axis and comprise:

a guiding element (6) allowing optimal alignment of the device with the said object (15), having a stopping shoulder (7) laying on the object when the said device is placed against the object

at least one gripping blade (9) housed inside (16) the said guiding element, being able to glide in/out the said guiding element basically in radial direction, each such a blade comprising a hole (10) for a corresponding driving arm (8) to cross and glide through

an actuating element (4) that can be axially moved with respect to the mentioned guiding element (6) within a short travel range, comprising at least one thin curved arm (8) respectively included in a radial plane, the said arm being axially translated together with the said actuator, the said arm crossing and gliding through the said pierced gripping blade forcing it to glide in/out the guiding element basically in radial direction, simultaneously with the axial movement of the actuator (4) against the guiding element (6), towards the object in order to grip it and respectively in opposite direction in order to release the object

3. An apparatus as claimed in claim 2, characterized in that the said blades (9) have sharp gripping edges and the axial distance between the said stopping shoulder and the said edges when the blades extend out of the guiding element is slightly bigger than the thickness of the handled object, the protruding blades gripping the object from beneath

4. An apparatus as claimed in claim 2 or 3, wherein the said actuator is connected to the transport means (12) by which the said pickup device is transported, the said device further comprising a two components switching mechanism (1 ,2) that alternately changes the status of the said pickup device between an object-engaging status, subsequently determining the gripping blades (9) to pick up the object (Fig5), and respectively object- disengaging status, subsequently determining the gripping blades to release the object (Fig3), each time the said pickup device reaches the end-of-travel position to an object holder (Fig2), the switching mechanism being triggered by the axial movement of the actuator (4) against the guiding element (6) stopped at the object holder, one of its components (1) being attached to and carried by the said actuator (4) and the other one (2) being connected to the guiding element (6)

5. An apparatus as claimed in claim 4, wherein the said device is vertically moved using flexible means (12) on which the pickup device hangs gravitationally

6. An apparatus (22) as claimed in any of claims 2 to 5, serving an object processing master equipment (20), wherein the apparatus (22) is placed above the said master equipment (20) and the said object holders (18,24) are located under the horizontal plane supporting the apparatus