Abstract:
A transfer device for transporting parts includes a rotatable stand including first and second angularly spaced arms secured to the stand and able to rotate between a first location where parts are installed on the first arms and a second location where the parts are removed from the first arms, and actuators for raising and lowering the arms.

Description:
BACKGROUND OF INVENTION 
       [0001]    The present invention relates generally to an apparatus for receiving and presenting parts to an operating station in an industrial plant where components are being manufactured, processed or assembled. 
         [0002]    The trend toward a fork truck free environment in a manufacturing plant has resulted in the use of containers presented on dollies. Many of the shipping containers are only partially filled in order to comply with reach-and-part-pick ergonomics. 
         [0003]    In a manufacturing plant conventional methods and apparatus for transporting large parts do not permit effective presentation of the parts to the production operator in the space available without the operator having to walk from his station to retrieve the parts. Effective presentation of the parts would display multiple styles of large parts, such as doors of body sides, to the production operator while in the operation station. 
         [0004]    To overcome this shortcoming, an off-line area is set up to sequence the parts to the operator. But this adds considerable cost to the process. Preferably the parts would be placed closely, i.e., the part density would be high and would allow direct parts placement without sequencing. 
         [0005]    A need exists in the industry for a parts delivery system that would present material to production operators in a containerless manner with little or no interruption to the work cycle or process and in as small a space as possible. Preferably the system would reduce handling costs, require minimal support space, and deliver the parts to the operator without a fork truck. 
       SUMMARY OF INVENTION 
       [0006]    A transfer device for receiving and presenting parts includes a rotatable stand including first and second angularly spaced arms secured to the stand and able to rotate between a first location where parts are installed on the first arms and a second location where the parts are removed from the first arms, and actuators for raising and lowering the arms. 
         [0007]    The invention contemplates a method for operating a transfer device including providing a rotatable stand including first and second angularly spaced arms able to rotate about an axis between first and second locations, moving a cart carrying a batch of parts to the first location such that the first arms engage and lift the batch from the cart, raising the first arms and the batch of parts from the cart, and rotating the batch of parts to the second location. When empty of parts and raised to a rotation position, the second arms are rotated to the first location concurrently with rotating the batch of parts to the second location, thus making the second arms available to receive the next delivery of parts. 
         [0008]    The transfer device presents parts to the production operator without a shipping/storage container, allows transfer devices to be positioned close together due to the empty arms of the one device being lifted above those of the adjacent device, and unloads the parts directly from the container or delivery cart without the use of a fork lift. 
         [0009]    The transfer device provides improved ergonomics for the production operator, requires no loss of throughput during parts replenishment, provides improved ergonomics for the material delivery operator, and enables a higher part density in delivery containers or carts, thereby resulting in lower container investment and associated handling and freight costs. 
         [0010]    The scope of applicability of the preferred embodiment will become apparent from the following detailed description, claims and drawings. It should be understood, that the description and specific examples, although indicating preferred embodiments of the invention, are given by way of illustration only. Various changes and modifications to the described embodiments and examples will become apparent to those skilled in the art. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0011]      FIG. 1  is a side view showing a cart carrying parts to a transfer device; 
           [0012]      FIG. 2  is a side view showing parts lifted from the cart by the transfer device; 
           [0013]      FIG. 3  is a front view of the transfer device; 
           [0014]      FIG. 4  is a top view of the transfer device; and 
           [0015]      FIG. 5  is a side view of the transfer device. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Referring now to the drawings, there is illustrated in  FIG. 1  a wheeled cart  10  having a load bed  12  and a hand rail  14 . At least some of the wheels swivel to facilitate steering the cart manually. The load bed  12  is shown filled with parts  16 , which in the example being described are door panels for an automobile. Normally a materials operator manually grips the rail  14  and guides the cart  10  to a production workstation, where further manufacturing operations are performed on the door panels  16 . The cart  10  may be positioned via powered equipment if the load is too heavy for manual pushing. A fork lift may also be used to position the parts on the receiving arms of the device. 
         [0017]      FIG. 2  shows the cart  10  located before a transfer device  20  in the form of a turnstile having a stand  22  with arms or pairs of arms  24 ,  26 , each arm being able to rotate about an axis  28  between the location of the cart  10  and a production workstation, indicated generally at  30 . Arms  24 ,  26  extend radially from axis  28  and rotate sequentially such that when arms  24  are directed from axis  28  toward the location of the cart, arms  26  are directed from the axis toward the workstation  30 . When arms  26  are directed toward the location of the cart, arms  24  are directed toward workstation  30 . 
         [0018]    The inner end of arms  24  is attached to a lift cylinder  32  containing a piston  34 , which may be actuated electrically or by pneumatic or hydraulic pressure in the cylinder, to raise and lower arms  24 . Similarly, inner end of arms  26  is attached to a lift cylinder  36  containing a piston  38 , which is actuated by pneumatic pressure in the cylinder to raise and lower arms  26 . 
         [0019]    As  FIGS. 3 ,  4  and  5  illustrate, the transfer device  20  further includes a floor mount plate  44 , stewing bearing  46 , trolleys  48 , mount plates  50  and turnstile arm assemblies  52 . 
         [0020]    The mount plate  44  is secured to the floor. The slewing bearing  46  rests on plate  44  and supports the stand  22  for rotation about axis  28 . An air motor  47  may be used to turn the stand about axis  28 , or the stand may be turned manually by applying a turning force to the arms  24 ,  26 . 
         [0021]    Each lift cylinder  32 ,  36  is sized in bore and stroke to facilitate the required lift height and weight of the parts it carries. 
         [0022]    Each turnstile arm assembly  52  includes a cross member  56 , secured to a mount plate  50 , which is secured to a trolley  48 . Each cross member carries a pair of arms  24 ,  26 . 
         [0023]    The stand is formed with vertical rails  60 , in each of which a trolley  48  is guided and moves when actuated by a respective cylinder  32 ,  36  to raise and lower the arms  24 ,  26 . Each cross member carries a pair of arms  24 ,  26 . 
         [0024]    In operation, the cart  10  is moved to the transfer device  20  such that the free end of arms  24 ,  26  passes through an opening  40  in the part  16 , and the length of the arms supports each part by engaging a surface  42  on the part. As arms  24  are raised, the parts  16  are lifted from the load bed  12 , allowing the cart  10  to be removed from the transfer device  20 , loaded with a new batch of parts  16  and returned to the device  20 . The transfer device  20  remains in the position shown in  FIG. 2  until the production operator is ready for a more parts to process. 
         [0025]    When the production operator has removed each part  16  from the arms  26  that are located at the workstation  30 , the stand  22  is rotated about axis  28 , thereby moving arms  26  from the workstation to the diametrically opposite location, where they await being used to unload a batch of parts  16  from cart  10 . This rotation moves the arms  24  on which the parts  16  are carried to workstation  30  from the diametrically opposite location, where the batch of parts  16  were unloaded from a cart  10 . Then the production operator removes parts  16  from arms  24  until those arms are empty, whereupon the stand rotates another batch of parts on arms  26  to workstation  30 . 
         [0026]    In accordance with the provisions of the patent statutes, the preferred embodiment has been described. However, it should be noted that the alternate embodiments can be practiced otherwise than as specifically illustrated and described.