Patent Document

FIELD 
   The invention relates to a device and method for handling mass produced work pieces. More particularly, the present invention is a device and method for the rapid picking and placing of work pieces from one tray to another. 
   BACKGROUND 
   In the rapid development of industrial automation great progress has been made in the mass production of products. Starting with the concept of the assembly line, today&#39;s factories have advanced where high-quality complex products can be mass produced. However, even when an assembly line is utilized and the workpiece travels from one workstation to another at which further processing occurs to the work piece at each station, it is still frequently necessary to physically move the work piece from a conveyor belt to a tooling machine or from one type of tray to another for cleaning or testing of the work piece. Therefore, one critical operation in a factory environment is the ability to move work pieces as quickly as possible from one station to the next, or from the assembly line to the tooling machine, or from one tray to another without damaging the work piece. 
   In the early days of manufacturing the movement of work pieces was frequently done by human workers. Of course, this was frequently difficult, dangerous and time-consuming work. With the advent of the industrial robots a significant improvement in the movement of work pieces was achieved since the robot could be programmed to endlessly pickup and move work pieces. However, even though a robot could pickup and place the work piece faster and more consistently than a human being, it was still a relatively slow process since the robot usually only picked up and placed one work piece at a time. 
   Therefore, to improve the speed of moving work pieces from one area to another, robot tools were designed to pickup multiple work pieces in a row and placed them down simultaneously in a row. However, in chip manufacturing often chips are placed in nests/trays that contain several rows and several columns of individual chips. Often these chips must be moved from a nest in which some process, such as cleaning, has been performed to a tray for further processing, testing or packaging for shipment. If the nest or tray has six rows and ten columns and the robot tools can move six chips, or one row, at a time then the robot must make ten round trips to move all the chips in a nest to a tray. Even though robots may be designed for rapid movement, so many round trips would add a great deal to the manufacturing time when considering that tens of thousands of chips are continuously being output by a single assembly line in a factory. 
   Therefore, what is needed is a device and method that can efficiently move an entire tray of chips or work pieces. This device and method should reduce manufacturing costs by reducing the amount of time it takes to manufacture an item. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and a better understanding of the present invention will become apparent from the following detailed description of exemplary embodiments and the claims when read in connection with the accompanying drawings, all forming a part of the disclosure of this invention. While the foregoing and following written and illustrated disclosure focuses on disclosing example embodiments of the invention, it should be clearly understood that the same is by way of illustration and example only and the invention is not limited thereto. The spirit and scope of the present invention are limited only by the terms of the appended claims. 
     The following represents brief descriptions of the drawings, wherein: 
       FIG. 1  is an example systems overview of an example embodiment of the present invention; 
       FIG. 2  is a top view of a rotary pick and place device in an example embodiment of the present invention; 
       FIG. 3  is a side view of a rotary pick and place device in an example embodiment of the present invention; 
       FIG. 4  is a side view of a rotary pick and place device in an example embodiment of the present invention 
       FIG. 5  is a top view of a rotary pick and place device in an example embodiment of the present invention; and 
       FIG. 6  is an example of the control logic utilized in an example embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
   Before beginning a detailed description of the subject invention, mention of the following is in order. When appropriate, like reference numerals and characters may be used to designate identical, corresponding or similar components in differing figure drawings. Further, in the detailed description to follow, exemplary sizes/models/values/ranges may be given, although the present invention is not limited to the same. As a final note, well-known components of computer networks may not be shown within the FIGS. for simplicity of illustration and discussion, and so as not to obscure the invention. 
     FIG. 1  is an example systems overview of an example embodiment of the present invention. In this system diagram two rotary pick and place devices  20  are shown connected to a computer system  10 . However, as would be appreciated by one of ordinary skill in the art, any number of rotary pick and place devices  20  may be connected to and controlled by computer system  10 . In addition, a single computer system  10  or processor may be dedicated to each rotary pick and place device  20 . Further, computer system  10  may be an embedded processor in the rotary pick and place device  20 . The computer system  10  would execute the logic illustrated and further discussed in detail in reference to  FIG. 6 . 
     FIG. 2  is a top view of a rotary pick and place device  20  in an example embodiment of the present invention. The rotary pick and place device  20  may be supported by up to four supporting members which are affixed from either above or below to a solid surface. It should be noted that screw drive  230  is utilized to move the rotary pick and place device  20  in the y axis while movement arm  240  is utilized to move the rotary pick and place device  20  in the x-axis. It should also be noted that support members  250  connected to screw drive  230  may not be required and the entire structure shown in  FIG. 2  may be supported by the supporting members  250  connected to the movement arm  240 . 
     FIG. 3  is a side view of a rotary pick and place device  20  in an example embodiment of the present invention. In order to simplify  FIG. 3  to more clearly illustrate the invention, movement arm  240  is shown without supporting members  250  and screw drive  230  which are depicted in  FIG. 2 . As shown in  FIG. 3 , rotary wheel  300  is connected to movement arm  240  via cross member  330 . Contained within the outer circumference of rotary wheel  300  are a plurality of pick heads  310 . These pick heads  310  are used to pickup work pieces  320  and may comprise any type of grasping tool including a suction device, electromagnetic device, grasping device, etc. The specific type of pick heads  310  used would be directly dependent upon the nature of the work piece  320 . For example, it may be preferable in the case where the work pieces  320  are silicon chips for the pick head  310  to be a suction device. Rotary wheel  300  may rotate clockwise or counterclockwise and when a pick head  310  is positioned over a work piece  320  in a nest  350  the pick head  310  would be extended to pickup the work piece  320 . The rotary wheel  300  would rotate and be positioned so that the next pick head  310  would be over the next work piece  320 . This operation would continue until all the work pieces  320  in a tray  400  and or nest  350  were picked up by the pick heads  310  on the rotary wheel  300 . Once all the work pieces  320  have been picked up individually by pick heads  310  from nest  350  the work pieces  320  may be moved to another nest  350  or a tray  400  for packaging and shipping, as shown in  FIG. 4 , discussed ahead. The number of pick heads  310  would correspond to the largest nest  350  or tray  400  that the rotary pick and place device  20  could handle. Therefore, if the nest  350  or tray  400  contained six rows and ten columns of work pieces  320 , then the rotary wheel  300  would have  60  pick heads  310 . 
   Still referring to  FIG. 3 , in an alternate embodiment of the present invention, a camera  360  may be provided for inspection of the work pieces located in nest  350  and may optionally be connected to computer system  10 , shown in  FIG. 1 , so that work pieces  320  may be selected for pickup by pick heads  310  dependent upon imperfections detected by camera  360 . It should further be noted that nest  350  may be traveling along a conveyor belt while being picked up by the rotary pick and place device  20 . 
     FIG. 4  is a side view of a rotary pick and place device  20  in an example embodiment of the present invention.  FIG. 4  is similar to  FIG. 3  with the exception that camera  360  is absent and trays  400  are provided so that work pieces  320  may be placed into the trays  400  by the pick and place device  20  using pick heads  310 . It should be noted that a portion or an entire tray may be filled utilizing the pick and place device  20  shown in  FIG. 4 . All remaining elements of  FIG. 4  are identical to that in  FIG. 3  and will not be discussed further here. 
     FIG. 5  is a top view of a rotary pick and place device  20  in an example embodiment of the present invention. A single rotary pick and place device  20  is shown in two locations in the figure starting next to the wash and dry area  500  and then being moved by the rotary pick and place device  20  to and from the nest  350  and trays  400 . Therefore, the rotary pick and place device  20  has a capability of moving both in the y axis, via the screw drive  230 , and the x-axis, via the movement arm  240 . Again both the screw drive  230  and movement arm  240  are supported by support members  250 . This figure is provided to show that the rotary reap pick and place device  20  may move work pieces from a nest to a workstation, such as wash and dry area  500 , and back to a tray  400  for further processing or packaging. 
   Before proceeding into a detailed discussion of the logic used by the embodiments of the present invention it should be mentioned that the flowchart shown in  FIG. 6  may contain software, firmware, hardware, processes or operations that correspond, for example, to code, sections of code, instructions, commands, objects, hardware or the like, of a computer program that is embodied, for example, on a storage medium such as floppy disk, CD Rom, EP Rom, RAM, hard disk, etc. Further, the computer program can be written in any language such as, but not limited to, for example C++. 
     FIG. 6  is an example of the control logic utilized in an example embodiment of the present invention. The control logic shown in this figure would execute in computer system  10 , shown in  FIG. 1 . Processing begins in operation  600  and immediately proceeds to operation  610 . In operation  610 , the type and size of the nest  350  or tray  400  is determined. This is required in order to position the pick heads  310  over the work pieces  320 . Thereafter, processing proceeds to operation  620  where the initial load position of the nest  350  or tray  400  is determined. In operation  630 , the rotary wheel  300  is positioned over a specified row and column. Processing then proceeds to operation  640  where a pick head  310  is extended down to the work piece  320  and picks it up. Thereafter, in operation  650  the rotary wheel  300  is rotated clockwise or counterclockwise and simultaneously moved in the x-axis or y-axis direction so that the pick head  310  is located over the next work piece  320  in the row or column of the nest  350  or tray  400 . In operation  660  it is determined if all work pieces  320  in a given row or column have been picked up or all work pieces  320  in a tray have been picked up. If all the work pieces  320  in the tray  400  have not been picked up then processing loops back to operation  630 . 
   Still referring to  FIG. 6 , if all work pieces  320  in a tray  400  or nest  350  have been picked up, then processing proceeds to operation  670 . In operation  670 , the rotary pick and place device  20  is positioned over a nest  350  or tray  400  that is to receive work pieces  320 . As noted in  FIGS. 2 and 5 , the rotary reap pick and place device would be positioned utilizing screw drive  230  and movement arm  240 . Processing then proceeds to operation  680  where the rotary pick and place device  20  is positioned over a specific row or column of the receiving nest  350  or tray  400 . In operation  690 , a pick head  310  is extended down and releases a work piece  320  into the nest  350  or tray  400 . In operation  700 , the rotary wheel  300  is rotated and positioned over the next location in the row and column of the nest  350  or tray  400 . Further, the work piece  320  is placed down into the nest  350  or tray  400 . In operation  710  it is determined whether all the work pieces  320  have been deposited for a given row or colunm and nest  350  or tray  400 . If all work pieces  320  have not been deposited in nest  350  or tray  400  from rotary wheel  300  then processing loops back to operation  670 . Otherwise processing proceeds to operation  720 , where processing terminates. 
   Still referring to  FIG. 6 , it should be noted that operations  610  through  660  are utilized to pick up work pieces  320  from, for example, a tray  400  coming down a conveyor belt with the intent of delivering these to a workstation for further processing. Operation  670  through  710  are intended, but not limited to, retrieving the work pieces  320  from the nest  350  or tray  400  after processing has been completed and returning them to the tray  400  for further processing in the assembly line for packaging. 
   One benefit resulting from the present invention is that a high speed device and method of moving work pieces from one container to another is provided, thereby reducing the amount of time it takes to mass produce work pieces and reducing the cost of manufacturing. 
   While we have shown and described only a few examples herein, it is understood that numerous changes and modifications as known to those skilled in the art could be made to the example embodiment of the present invention. Therefore, we do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

Technology Category: b