Abstract:
A method and an apparatus for handling objects, in particular discs such as CD&#39;s having an aperture therein defining a rim. The apparatus comprises a first set of jaws moveable towards and away from one another and a second set of jaws moveable towards and away from one another. In use, the jaws of each set may be moved apart to exert a radial gripping force on the rims of the objects. The second set of jaws is extendible and retractable axially. By operating the sets of jaws through sequences of extension, gripping, retraction and releasing, the objects can be loaded onto or off of the apparatus. The gripping action of the jaws allows the apparatus to hold the objects in any orientation.

Description:
BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   The present invention concerns an object handling apparatus and method, and in particular an object handling apparatus and method adapted to stack and/or unload objects such as discs having at least one aperture therein defining an inner rim, such as compact discs, dvd&#39;s, floppy discs, mobile phone covers, etc. 
   (2) Description of Related Art 
   The production and post production handling of such mass produced objects invariably involves the use of automated robotic equipment in manipulating and/or transporting the objects during the various manufacturing stages. The faster the objects can be handled by such equipment, the greater the manufacturing output, and therefore the more cost effective the entire manufacturing operation. 
   However, conventional robotic arms or the like are only capable of handling individual objects. Thus, in use, the arm grips the first object, and then transports the object to another location, before returning to collect the next object. This process is repeated continually until all of the objects have been transferred to the required location. 
   The method and apparatus of the present invention enable a large number of a particular object to be handled at once, thus dramatically reducing the number of operations required to transfer a given number of the objects from one location to another, and thus the time and cost of manufacture. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention therefore provides, in a first aspect, an apparatus for handling objects, each object having an aperture therein defining a rim, the apparatus comprising a support on which, in use, one or more objects may be stacked, or unloaded from; an arm located adjacent the support; and control circuitry adapted to effect extension of the arm through the aperture of at least one of the objects, displacement of the arm into engagement with the rim of the at least one object, retraction of the arm such as to position the rim over the support, and displacement of the arm such that the rim is engaged by the support. 
   Preferably, the arm and the support are elongate, and are substantially parallel to one another. 
   Preferably, the arm is provided with a plurality of indentations spaced apart along the length thereof. 
   Preferably, the support is provided with a plurality of indentations spaced apart along the length thereof. 
   Preferably, the apparatus is provided with a sensor which is adapted to detect when a preset number of objects have been stacked on the support. 
   Preferably, the arm is comprised of a first set of jaws movable relative to one another. 
   Preferably, the support is comprised of a second set of jaws movable relative to one another and the first set of jaws. 
   Preferably, the support is substantially penannular in cross-section such that the arm, when retracted, is substantially recessed within the support. 
   According to a second aspect of the present invention, there is provided a method of handling objects, each object having an aperture therein defining a rim, the method comprising the steps of providing an apparatus according to the first aspect of the invention; extending the arm through the aperture of at least one of the objects; displacing the arm into engagement with the rim of the at least one object; retracting the arm such as to position the rim over the support; and displacing the arm such that the rim is engaged by the support. 
   Preferably, the arm is extended through the aperture in a first direction; the arm is displaced in a second direction, substantially perpendicular to the first direction, such as to engage the rim; the arm is retracted in the first direction; and the arm is displaced in the second direction such that the rim is engaged by the support. 
   Preferably, the method comprises the steps of providing the arm as a first set of jaws moveable relative to one another; providing the support as a second set of jaws moveable relative to one another and the first set of jaws; in engaging the arm with the rim, advancing the first set of jaws away from one another such as to engage the rim at two locations; following retraction of the arm, advancing the second set of jaws away from one another, such as to engage the rim at two locations; and in retracting the arm, advancing the first set of jaws towards one another, such as to disengage the rim. 
   Preferably, the method comprises the steps of providing a plurality of indentations spaced apart along the length of the arm. 
   Preferably, the method comprises the steps of providing a plurality of indentations spaced apart along the length of the support. 
   As used herein, the term “aperture” is intended to mean an opening in an object through which another object may pass, and is not intended to be limited to apertures which are closed on all sides, and could for example cover an aperture formed within, and by, a penannular object. 
   As used herein, the term “circuitry” is intended to cover electrical, mechanical, hydraulic, and pneumatic equipment, whether individually or in combination, which is arranged and adapted to effect the displacement of mechanical components, and could for example include servo motors, solenoids, hydraulic/pneumatic rams, in addition to any other control equipment necessary to operate the above devices. 

   
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE INVENTION 
     The present invention will now be described with reference to the accompanying drawings, in which; 
       FIGS. 1  (A)-(E) illustrate a respective side elevation of five sequential operations of a first embodiment of an apparatus, in stacking an apertured disc onto the apparatus; 
       FIGS. 1  (F)-(J) each illustrates a corresponding end view of the apparatus of  FIGS. 1  (A)-(E) respectively; 
       FIG. 2  (A)-(E) illustrate a respective side elevation of five sequential operations of the apparatus of  FIG. 1  in stacking a second apertured disc on the apparatus; 
       FIGS. 2  (F)-(J) each illustrates a corresponding end view of the apparatus of  FIGS. 2  (A)-(E) respectively; 
       FIG. 3  (A)-(E) illustrate a respective side elevation of five sequential operations of a second embodiment of an apparatus according to the present invention, in stacking an apertured disc onto the apparatus; and 
       FIGS. 3  (F)-(J) each illustrates a corresponding end view of the apparatus of  FIGS. 3  (A)-(E) respectively; 
       FIG. 4  (A)-(E) illustrate a respective side elevation of five sequential operations of the apparatus of  FIG. 3  in stacking a second apertured disc onto the apparatus; 
       FIGS. 4  (F)-(J) each illustrates a corresponding end view of the apparatus of  FIGS. 4  (A)-(E) respectively; 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring then to  FIGS. 1 and 2  of the accompanying drawings, there is illustrated a first embodiment of an object handling apparatus, generally indicated as  10 , which, in use, one or more objects such as discs  12 , each having an aperture  14  therein defining a rim  15 , may be stacked on and/or unloaded from. The apparatus  10  is primarily intended to be used in a substantially horizontal orientation. The purpose of the apparatus  10  is to pick up and stack one or more of the discs  12 , which in practice will take the form of articles such as CD&#39;s (compact discs), DVD&#39;s (digital video discs), computer discs, mobile phone covers, etc, (not shown). The apparatus  10  is primarily intended to form an integral component of an assembly line (not shown), and may be articulated to move the discs  12  stacked thereon from one located to another, and to then unload the discs  12  as required. For example, during the production of CD&#39;s or DVD&#39;s, once the requisite information (e.g. music, computer software, etc.) has been “burnt” onto the disc  12 , the disc  12  will normally be transferred to a packaging assembly line, where the disc  12  is inserted into a suitable case or the like (not shown). Some form of machine or robotic arm (not shown) will conventionally be utilised to effect the transfer, and indeed the large number of additional transfers required in any high volume assembly line operation. The apparatus  10  would therefore likely be utilised on the end of a suitably modified robotic arm in place of conventional grippers (not shown). As will be described in detail hereinafter, the apparatus  10  is preferably provided with control circuitry (not shown), which may be comprised of electrical components (e.g. servo motors), hydraulic or pneumatic rams (not shown) or any other functional equivalents, in order to operate the apparatus  10 , all of which are conventionally utilised in powering robotic arms or the like, ensuring that the apparatus  10  may be easily retrofitted to existing equipment, or integrated into an existing assembly line. 
   The apparatus  10  primarily comprises an elongate support  16  which, in use, the discs  12  are stacked on and/or unloaded from. The support  16  includes a plurality of indentations in the form of grooves  22  equally spaced from one another along the length of the support  16 , into each of which grooves  22  a single disc  12  may be seated, as will be described in greater detail hereinafter. The apparatus  10  further comprises an elongate arm  18  which is adapted, again as will be described in detail hereinafter, to retrieve a disc  12  from a given location and stack said disc  12  onto the support  16 , and repeating this stacking with a plurality of the discs  12 , before transferring same to another location. The arm  18  includes a plurality of indentations  24  within each of which a single disc  12  is seated during transport onto or off the support  16 . The grooves  22  and indentations  24  prevent, during use, any of the discs  12  seated on either the support  16  or arm  18  from contacting, and therefore possibly damaging, one another. 
   The support  16  and arm  18  are disposed, in the embodiment illustrated, in parallel to one another, the arm  18  being moveable relative to the support  16 . Specifically, the support  16  is substantially penannular in cross-section, thereby defining a centrally disposed channel  20 , within and about which the arm  18  is moveable. Utilising this penannular shape provides a number of advantages. The channel  20  serves to both support and guide the arm  18 , while ensuring that the combined cross sectional area of the support  16  and arm  18  is kept to a minimum, in order to permit same to pass through the aperture  14  of each disc  12  as required, and as will be described in detail hereunder. In addition, the channel  20  results in the rim  15  of each disc  12  being contacted at two locations when seated on the support  16 , one on either side of the channel  20 , thereby providing increased stability to the discs  12  when being transported to any other location. 
   In the embodiment illustrated, the support  16  is mounted to a body  26 , within which is located a base  28  to which the arm  18  is mounted. The base  28  is moveable within the body  26 , as indicated above, by such means as hydraulics, pneumatics, or the like, such as to effect movement of the arm  18  relative to the support  16 . The apparatus  10  is primarily intended for use in a substantially horizontal position, and as the support  16  and arm  18  are fixed at one end to the body  24 , the apparatus is cantilever in form. Therefore, depending on the operating loads experienced by the apparatus, which will vary depending on the number and composition of objects (e.g. discs  12 ) to be stacked thereon, both the support  16  and arm  18  are preferably formed from a rigid material, for example a metal, a composite, a plastic or reinforced plastic, or indeed any other suitable alternative. 
   If necessary, depending on the objects with which the apparatus  10  is to be used, a suitable protective coating or layer (not shown), for example rubber or the like, may be provided on the support  16  and arm  18 , in particular on the contact surfaces thereof, in order to reduce the possibility of damage to the objects. 
   Therefore, referring to  FIGS. 1(A)  and (F), the apparatus  10  is located such that contiguous free ends of the support  16  and arm  18  are located proximal a first disc  12 , and in particular the apparatus  10  is located such that the support  16  and the arm  18  are aligned with the aperture  14  in the disc  12 . It will of course be appreciated that this initial alignment is likely to be performed via computer control. In this initial state the arm  18  is fully recessed within the channel  20 . Referring then to  FIG. 1(B) , the arm  18  is extended through the aperture  14 , in a first direction A, such that the first indentation  24  is coplanar with the disc  12 . This extension may be effected by, for example, the extension of a hydraulic/pneumatic ram, a solenoid, or an electric motor (not shown) located internally of the body  26 , or alternatively forming part of the robotic arm (not shown) or the like, to which the apparatus  10  is mounted. Referring then to  FIGS. 1(C)  and (H), the arm  18  is raised upwardly, in a second direction B substantially perpendicular to the first direction A, out of the channel  20 , thereby engaging the rim  15  of the aperture  14 , within the first indentation  24 , such as to pick the disc  12  up from its rest position. Again this displacement is effected by one or more of the devices mentioned above with reference to  FIGS. 1(B)  and (G). It should be noted that the displacement of the arm  18 , such as to contact the rim  15 , is preferably in a direction substantially parallel to the plane of the disc  12 . This ensures an accurate contact between the rim  15  and base of the indentation  24 , thereby ensuring no relative movement between the disc  12  and the arm  18  following the initial contact therebetween. Any such relative movement could cause momentary swinging of the disc  12 , which could then contact, and possibly damage, any adjacent disc  12 . 
   Continuing on to  FIGS. 1(D)  and (I), the arm  18 , while remaining out of the channel  20 , is retracted in the direction A such as to effectively draw the support  16  through the aperture  14 , until the disc  12  is aligned with the first groove  22  on the support  16 . It will thus be appreciated that as the disc  12  is drawn over the support  16 , such that the support  16  passes through the aperture  14 , the support  16  must be shaped and dimensioned to allow passage through the aperture  14 . Thus the size and shape of the support  16  will vary depending on the object with which the apparatus  10  is to be used. It will also be apparent that the penannular shape of the support  16  makes efficient use of the available space, having a relatively large cross-sectional area to provide rigidity along the length thereof, while effectively housing the arm  18  in the central channel  20 . 
   Referring now to  FIGS. 1(E)  and (K), the arm  18  is dropped back into the channel  20  in the direction B, thereby lowering the disc  12  into engagement with the first groove  22  on the support  16 . As with displacement of the arm  18  to initially contact and raise the disc  12 , the arm  18  is preferably retracted in a direction substantially parallel to the plane of the disc  12 , to ensure an accurate transfer of the disc  12  from the indentation  24  of the arm  18 , to the respective groove  22  of the support  16 , for the reason hereinbefore described. Once the arm  18  is fully retracted within the channel  20 , the disc  12  is fully disengaged therefrom. At this point, the apparatus  10  has returned to the initial configuration illustrated in  FIGS. 1(A)  and (F), but with a disc  12  seated on the support  16 , in the first groove  22  thereof. In order to ensure that sufficient stability is provided to the disc  12  while stacked on the apparatus  10 , the upper surface of the support  16 , in addition to the plurality of grooves  22 , is preferably arcuate such as to provide complementary contact along a substantial portion of the rim  15  of the aperture  14 . 
   In order to then stack a second disc  12 ′ and subsequent discs  12  onto the support  16 , the above sequential steps are repeated for each disc  12  to be stacked, until the desired number of discs are located on the support  16 , or until each groove  22  on the support  16  has been filled. Thus, referring to FIG.  2 -(J), the apparatus  10  is illustrated with a first disc  12  seated within the first groove  22  of the support  16 , and the second disc  12 ′ being retrieved and stacked onto the support  16 .  FIGS. 2(A)  and (F) shows the arm  18  being extended through the aperture  14  of the second disc  12 ′. While the arm  18  is being extended in direction A, it is kept retracted within the channel  20 , such as not to engage the first disc  12  seated on the support  16 . 
   Referring to  FIGS. 2(B)  and (G), once the arm  18  has been extended such that the first indentation  24  is coplanar with the second disc  12 ′, the arm  18  is raised in direction B, substantially parallel to the plane of the second disc  12 ′, such as to engage and raise the second disc  12 ′. However, in raising the arm  18 , it can be seen that the first disc  12  is also raised out of the respective groove  22  and is therefore also supported entirely by the arm  18 . Referring to  FIGS. 2(C)  and (H), the arm  18  is retracted in direction A, as hereinbefore described, with the first and second discs  12 ,  12 ′ therefore being drawn rearwardly relative to the support  16 . 
   Turning then to  FIGS. 2(D)  and (I), the arm  18  is again lowered into the channel  20  in direction B, thereby resulting in the first and second discs  12 ,  12 ′ each being lowered into adjacent grooves  22  on the support  16 , such as to again return the apparatus  10  to it&#39;s initial configuration. Referring to  FIG. 2(E)  and (J), the above sequence may then be repeated by again extending the arm  18  such as to retrieve a third disc  12 ″. It will therefore be appreciated that as the above sequence is repeated, the plurality of discs  12  will be simultaneously moved rearwardly along the support  16 , one groove  22  at a time, towards the body  26 . 
   The apparatus  10  is therefore provided with a sensor  30  mounted to the body  26 , which sensor  30  is adapted to detect when the final groove  22  on the support  16  has been filled with a disc  12 , thereby indicating that all of the grooves  22  on the support  16  have been filled. Thus the sensor  30  is adapted to generate a signal which may terminate operation of the apparatus  10 , generate a signal to which an operator responds, or displace the apparatus  10  to a new location within the assembly line (not shown). The sensor  30  preferably operates as a proximity detector, utilising conventional infrared or ultrasonic technology or the like, although the sensor  30  could be of any other suitable type. For example, the last groove  22  in the support  16  could be provided with a pressure sensor (not shown) or the like disposed therein, which would therefore be operable to determine when the groove  22  had been filled with a disc  12 . 
   At any point during stacking of the apparatus  10  with the discs  12 , the above sequence may be reversed in order to unload the discs  12  from the apparatus  10  to any given location. Such reversal of the above sequence would preferably be effected by computer control, for example following transport of the loaded apparatus  10  to another location at which the discs  12  are required. 
   It will however be appreciated from the foregoing description that the discs  12  remain suspended in position on the support  16  under the influence of gravity, and thus the apparatus  10  is only suited for use in a horizontal orientation. 
   Referring then to  FIGS. 3 and 4  of the accompanying drawings, there is illustrated a second embodiment of an object handling apparatus, generally indicated as  110 , for use in stacking and/or unloading objects such as discs  112  from an off horizontal, preferably vertical, orientation. In the second embodiment like components have been accorded like reference numerals, and unless otherwise stated, perform a like function. Thus the apparatus  110  essentially comprises a support in the form of a first pair of jaws  116 , and an arm in the form of a second pair of jaws  118  located in parallel spaced relation to the first jaws  116 . The first jaws  116  are mounted to a body  126 , while the second jaws  118  are mounted to a base  128  disposed within the body  126 . 
   As with the first embodiment, the apparatus  110  is provided with control circuitry (not shown) comprising electrical components (e.g. servo motors), hydraulic or pneumatic rams (not shown) or any other functional equivalents, in order to power the apparatus  110 . In particular, the control circuitry (not shown) is operable to control the movement of the first jaws  116  relative to one another and the second jaws  118 , and the second jaws  118  relative to one another and the first jaws  116 . The apparatus  110  operates on the same basic principal as the apparatus  10  of the first embodiment, with a number of variations described hereunder, in order to enable the apparatus  110  to operate in a non-horizontal position. The apparatus  110  is therefore not dependent on gravity to hold the discs  112  in position thereon. 
   Referring to  FIGS. 3(A)  and (F), the apparatus  110  is located such that the free ends of the first jaws  116  and second jaws  118  are located proximal an aperture  114  of the disc  112  to be stacked. Turning then to  FIG. 3(B) , the second jaws  118  are extended in a direction A such as to pass through the aperture  114  until a first set of indentations  124  are disposed coplanar with the disc  112 . Referring to  FIGS. 3(C)  and (H), the second jaws  118  are then advanced away from one another, in a direction B substantially perpendicular to direction A, such as to engage a rim  115  of the aperture  114 , at a pair of oppositely disposed points, as defined by the first set of indentations  124 . 
   The second jaws  118  are then retracted in direction A, as illustrated in  FIGS. 3(D)  and (I), such as to effectively draw the first jaws  118  through the aperture  114  of the disc  112 , until the rim  115  of the disc  112  is aligned with a first set of grooves  122  on the first jaws  116 . During this retraction of the second jaws  118 , the first jaws  116  are disposed in close proximity with one another in order to prevent fouling thereof with the rim  115 . The first jaws  116  are then advanced, as illustrated in  FIG. 3(E)  and (J), away from one another in a direction C substantially perpendicular to both direction A and B, such as to engage the rim  115  of the aperture  114 . The second jaws  118  may then be advanced towards one another in direction B such as to disengage the disc  112 , which is then supported solely by the first jaws  116 . As detailed above with reference to the first embodiment, the first jaws  116  and the second jaws  118  should be displaced towards and away from each disc  112  in a direction substantially parallel to the plane of the disc  112 , in order to prevent any unwanted movement between the disc  112  and the apparatus  110 . 
   Turning then to  FIG. 4 , the above sequence may then be repeated to stack a second disk  112 ′ and subsequent discs  112 . Thus referring to  FIGS. 4(A)  and (F), with the first disc  112  retained by the first jaws  116 , the second jaws  118  are advanced in direction A through the aperture  114  of the second disc  112 ′. Turning to  FIGS. 4(B)  and (G), the second jaws  118  are then advanced away from one another in direction B such as to engage both the first and second discs  112 ,  112 ′ in respective indentations  124 . The first jaws  116  are then advanced towards one another in direction C such as to disengage the first disc  112 . Turning to  FIGS. 4(C)  and (H), the second jaws  118  are then retracted in direction A such as to draw the second disc  112 ′ over the first jaws  116 . This retraction of the second jaws  118  also draws the first disc  112  further along the first jaws  116 . 
   Referring to  FIGS. 4(D)  and (I), the first jaws  116  are then advanced away from one another in direction C such as to engage both the first and second disc  112 ,  112 ′ within respective grooves  122 , wherein the second jaws  118  are advanced towards one another in direction B such as to disengage the first and second discs  112 ,  112 ′. 
   Thus the first and second discs  112 ,  112 ′ are each engaged in a respective groove  122  of each of the first jaws  116 , such as to retain the discs  112 ,  112 ′ stacked in position on the apparatus  110 . Again, referring to  FIGS. 4(E)  and (J), the above sequence may then be repeated to stack further discs  112  onto the apparatus  110 , each sequence advancing the plurality of discs  112  upwardly along the first jaws  116 . The apparatus  110  is also provided with a sensor  130 , mounted to the body  126  and located proximal the final grooves  22  on the first jaws  116 , such as to detect the presence of a disc  112  in said grooves  122 , and thus generate an appropriate signal to cease operation of the apparatus  110 , and optionally transfer the discs  112 ,  112 ′,  112 ″ to another location for unloading. 
   It should also be understood that both the first jaws  116  and the second jaws  118 , in particular the grooves  122  and indentations  124 , may be provided with a layer or coating of protective material, for example rubber or the like, to reduce the possibility of damage to the discs  112  during operation of the apparatus  110 . 
   It will be appreciated that while the apparatus  110  is primarily intended to vertically stack discs  112 , it could of course be applied to discs (not shown) in any orientation, including horizontal. It will therefore also be appreciated that the apparatus  110  could be utilised to stack discs  112  which are presented to the apparatus  110  at one orientation, and which discs  112  could subsequently be unloaded from the apparatus  110  at an alternative orientation, which would not be possible with the apparatus  10  of the first embodiment. Therefore, although the configuration and operation of the apparatus  110  is slightly more complex than that of the first embodiment, the apparatus  110  does provided greater versatility.