Abstract:
A method of orienting a selected item from a stack of similar items, the method comprising the steps of separating, engaging and orienting. The separating step separates the selected item from the stack using a first attraction force of a transport apparatus. The engaging step engages the selected item with a second attraction force from the transport apparatus. The second attraction force being greater than the first attraction force. The orienting step orients the selected item relative to the transport apparatus as the transport apparatus is en route to a destination location.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a non-provisional application based upon U.S. provisional patent application Ser. No. 61/699,447 entitled “METHOD AND APPARATUS FOR THE ORIENTATION OF LAMINATIONS”, Sep. 11, 2012, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an orientation device, and, more particularly, to an orientation device for the movement of a metal lamination. 
         [0004]    2. Description of the Related Art 
         [0005]    Cold rolled steel also referred to as lamination steel, is in common use today for the production of laminations used in electric motors. The ease of stamping cold rolled steel and the resulting low tool wear contribute to the low cost of finished laminations. Whether this or some other material is used to produce the laminations, the process of making laminations include multiple operations before they are assembled as an electric machine, such as an electric motor or an electric generator. 
         [0006]    For example, once a lamination is cut from a sheet of steel, features cut into each lamination require that a subsequent operation index the lamination so that additional features can be added to the lamination. This can be handled in different ways. First, once the lamination has had an initial feature imparted to the lamination, the lamination may be stacked in an indexed manner and then moved in a coordinated manner to preserve the indexed position to a subsequent operation. This method unfortunately requires expensive handling of the stack of laminations. A second way is to have a non-indexed stack, then move each lamination to an indexing device, then move the lamination to the subsequent operation. This method suffers from the need to have a separate indexing station and the loss of floor space therefor. A third way is to put the lamination into the subsequent operation and have that device orient the lamination before performing the subsequent operation. This method disadvantageously significantly increases the cost of the tooling and slows the machine down because it first has to orient the lamination before performing a function on the lamination. 
         [0007]    What is needed in the art is an effective device to overcome these problems and to present the subsequent operational device with a pre-oriented lamination. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides an effective method and apparatus for the orienting of laminations. 
         [0009]    The present invention in one form is directed to a method of orienting a selected item from a stack of similar items, the method including the steps of separating, engaging and orienting. The separating step separates the selected item from the stack using a first attraction force of a transport apparatus. The engaging step engages the selected item with a second attraction force from the transport apparatus. The second attraction force being greater than the first attraction force. The orienting step orients the selected item relative to the transport apparatus as the transport apparatus is en route to a destination location. 
         [0010]    The present invention in another form is directed to an orienting device for a selected item from a stack of similar items. The orienting device includes a transport apparatus, an operational apparatus and a controller. The transport apparatus includes a first attraction force apparatus, a second attraction force apparatus and an orientation apparatus coupled to the second attraction force apparatus. The operational apparatus is configured to be a destination location for the selected item and to perform at least one further operation on the selected item. The controller is configured to engage the first attraction force apparatus to separate the selected item from the stack using a first attraction force. The controller is further configured to additionally engage the selected item with a second attraction force from the second attraction force apparatus. The second attraction force is greater than the first attraction force. The controller is yet further configured to activate the orientation apparatus to orient the selected item relative to the transport apparatus as the transport apparatus is en route to the operational apparatus. 
         [0011]    An advantage of the present invention is that the lamination is oriented while it is being moved to a workstation. 
         [0012]    Another advantage of the present invention is that the lamination is separated from the stack with a lower magnetic field and the magnetic field is increased while the lamination is en route to ensure that it is not dropped. 
         [0013]    Yet another advantage of the present invention is that the lamination arrives in a pre-indexed state at the subsequent machine. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0015]      FIG. 1  is a schematic perspective view of an embodiment of an orienting apparatus of the present invention; 
           [0016]      FIG. 2  is a more detailed view of the orienting apparatus of  FIG. 1 ; and 
           [0017]      FIG. 3  is schematical flow diagram illustrating the steps used by a method using the orienting apparatus of  FIGS. 1 and 2 . 
       
    
    
       [0018]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    Referring now to the drawings and more particularly to  FIG. 1  there is shown an operational center  10  having a stack of laminations  12 , a robotic arm  14  and an operational apparatus  16 . The stack of laminations  12  has a plurality of laminations that are not rotationally oriented in any particular manner. Robotic arm  14  has a manipulator fixture  18  attached thereto. Robotic arm  14  moves a singular lamination from lamination stack  12  to operational apparatus  16  for a subsequent operation, such as a pressing operation, a machining operation, or any type of operation that requires the lamination to be presented in an indexed or pre-oriented manner. 
         [0020]    Now, additionally referring to  FIG. 2  there is shown manipulator fixture  18  that is also referred to as a transport apparatus  18 , which is an extension of articulated robotic arm  14 . Manipulator fixture  18  includes a rotating apparatus  20 , gripping apparatuses  22 , a servo  24 , gripping apparatuses  26  and a sensor  28 . A lamination  30 , which is a selected item  30  or a material piece  30 , which may be a metal lamination  30  for use in an electric motor or generator (not shown), is shown having a material position locator feature  32 , here shown as a notch  32  in piece  30 . Numerous material pieces  30  are located at a material source position illustrated here as lamination stack  12 , and material pieces  30  may be in a stack with their outer boundaries substantially aligned, but in a random angular arrangement from each other. 
         [0021]    Now, additionally referring to  FIG. 3 , a method  100  illustrates an embodiment of a method of the present invention carried out by a controller  34 . At step  102 , robotic arm  14  is moved so as to position transport apparatus  18  so that is can pick up a lamination  30  from lamination stack  12 . At step  104 , manipulator fixture  18  picks up a singular lamination  30  from the material source position and moves it to a workstation  16  where further operations (such as machining, stamping operations, welding, etc.) are preformed on piece  30 . Lamination  30  is then removed from workstation  16 , perhaps by another robotic arm, and a new lamination  30  is placed into workstation  16  by manipulator fixture  18 . After picking up material piece  30  and while moving material piece  30 , manipulator fixture  18  rotationally indexes material piece  30  to a desired orientation so that material piece  30  is in the desired angular orientation when it arrives at workstation  16 . 
         [0022]    More specifically, once manipulator fixture  18  has been moved to the material source position  12 , at step  102  then articulated robotic arm  14  positions magnets  22 , in contact with or in close proximity to the uppermost lamination  30  in lamination stack  12 . At step  104 , magnets  22  are activated to grip lamination  30 . Then at step  106 , robotic arm  14  lifts manipulator fixture  18  along with a lamination  30  from the stack. Note, the figures, for purposes of clarity, do not show pneumatic and/or electrical interconnections. Magnets  22  may be in the form of pneumatically manipulated magnets  22  (although other gripping devices are also contemplated, such as electromagnets, suction devices, etc.) with the strength of magnets  22  being selected such that they collectively are strong enough to lift a single lamination  30 , but are not strong enough to lift additional pieces beneath the top piece  30 . Magnets  22  are also referred to as a first attraction force device  22 , providing a first attraction force to lamination  30 , also referred to as a selected item  30 . 
         [0023]    At step  108 , once lamination  30  is lifted from stack  12  then gripping apparatuses  26 , in the form of magnets  26 , are additionally activated. Magnets  26  are also referred to as a second attraction force device  26 , providing a second attraction force to lamination  30 . Magnets  26  have a stronger grip or attraction force than magnets  22 , since once lamination  30  has been separated from stack  12 , there is not a concern about magnetically attracting more than one lamination  30 . Movement of lamination  30  toward workstation  16  continues at step  110 , while steps  112 - 118  are carried out. As movement of articulated robotic arm  14  continues, magnets  22  are inactivated at step  112 , and lamination  30  is rotated at step  114 , while sensor  28  detects the position of notch  32 . The control of the rotational orientation takes place by sensor  28  sensing the position of material position locator  32  as servo  24  rotates magnets  26  and lamination  30 . At step  116 , controller  34  determines if lamination  30  is properly rotationally oriented, if not then rotation continues at step  114 . Otherwise, when sensor  28  senses the proper location of material position locator  32 , at step  116 , then the rotation is stopped since lamination  30  is in the desired rotational orientation for placement into workstation  16 . At step  118 , magnets  22  are reactivated to further secure lamination  30  to manipulator fixture  18  while lamination  30  is en route to workstation  16 . Once lamination  30  is positioned in workstation  16  as detected by step  120 , then magnets  22  and  26  are inactivated at step  122 , and articulated robotic arm  14  moves manipulator fixture  18  away from workstation  16  and method  100  is repeated, while the lamination  30  that has been delivered to workstation  16  is operated upon. 
         [0024]    Sensor  28  may be in the form of an optical sensor, a magnetic field sensor or a physical contacting sensor, or any sensor capable of detecting a material positioning feature  32  on lamination  30 . Controller  34  uses information from sensor  28  to control servo  24  as it rotates lamination  30 . Controller also controls the functioning of transport apparatus  18  and robot  14  in the carrying out of method  100 . The activation and inactivation of magnets  22  and  26  by controller  34  may be a manipulation of the orientation of the magnets so that more or less of the magnetic fields emanating therefrom is directed toward lamination  30 . Controller  34  may be separate from, or integral with, the control system that controls articulated robotic arm  14 . If separate then there may be an interface between the control systems to control the timing of the operation described herein. 
         [0025]    Advantageously, the present invention reduces the need for extra fixturing, such as an orientation station, also reducing the overall footprint of the operation. 
         [0026]    While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.