Abstract:
A recirculating device receives parts in bulk which are bunched together. The device includes a cone-shaped rotating disk which receives the parts and redistributes the parts into separate units. The parts are delivered to an inner periphery of the cone of the cone-shaped disk and then slide down the inclined slope of the cone. As the parts slide down the rotating cone, they become spaced further apart due to the increase in radius of the outer periphery of the cone as compared with the radius of the inner periphery of the cone. The separated parts may then be effectively handled by a picker-type robot utilizing a vision system or sensors to discriminate the individual parts.

Description:
This application is a non-provisional conversion application of provisional application No. 60/082,731 filed on Apr. 23, 1998, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a device for receiving parts in bulk which are bunched together, and redistributing the parts into separate units which may be effectively handled by a picker-type robot utilizing a vision system or sensor means to discriminate the individual parts. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a device which is simple in structure and which can reliably receive parts in bulk which are bunched together, and redistribute the parts into separate units which may be effectively handled by a picker-type robot utilizing a vision system or sensor means. 
     The present invention provides a recirculating device including a reservoir which receives parts in bulk that are bunched together. A cone-shaped rotating disk surrounds the reservoir and receives the parts and redistributes the parts into separate units. The parts are delivered to an inner periphery of the cone of the cone-shaped disk, and the parts then slide down the inclined slope of the cone to an outer flat disk surrounding the cone. As the parts slide down the rotating cone, they become spaced further apart due to the increase in radius of the outer periphery of the cone as compared with the radius of the inner periphery of the cone. The separated parts may then be effectively picked up off of the flat disk by a picker-type robot utilizing a vision system or sensor means to discriminate the individual parts. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more filly understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitative of the present invention, and wherein: 
     FIG. 1 is a schematic plan view of the recirculating device according to the invention; 
     FIG. 2 is a schematic partial cross-sectional side view thereof; 
     FIG. 3 is a cross-sectional view of a portion of a modification of the cone according to the invention; 
     FIG. 4 is a perspective view of the recirculating device showing the reservoir; 
     FIG. 5 is a perspective view showing the parts travelling up in the reservoir for discharge onto the cone-shaped disk; 
     FIG. 6 is a view showing one of the parts sliding down the sloped surface of the cone-shaped disk; and 
     FIG. 7 is a side view showing the drive mechanism of the cone-shaped disk and the free area underneath the flat disk. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention will be described with reference to a preferred embodiment shown in the accompanying drawings. 
     A recirculating device  10  includes a central rotating feeder, or centrifugal feeder, as a reservoir  12 . Parts are infed to the reservoir  12  from a prefilling device  14 . The articles will go to the upper lip of a central rotating disc  15  in the reservoir  12  whereat they will be discharged to an inclined outer cone  16 . A deflector  17  may be used to assist movement of the articles from the central rotating disc  15  to the cone  16 . Due to the shape of the cone  16 , the articles will slide down the cone  16  and spread out in a fan-shaped manner. This arrangement will enable the parts to spread out for subsequent handling by a robotic pickup device  18 . The central rotating disc  15  and the outer surrounding cone  16  can be independently driven so as to rotate at the same or different speeds. Independent motors  20 ,  22  may be used as shown in FIG.  7 . These speed variations can be used in order to increase or decrease the spacing between articles. The central rotating disc  15  rotates about an axis which is tilted with respect to vertical, whereas the cone  16  rotates about a vertical axis. As articles slide down the cone  16 , they are spaced from one another. The articles will then slide onto a rotating flat disc  24  surrounding the cone  16 . The cone  16  and the flat disc  24  can be a one-piece unitary construction or can be molded together or can be two separate parts. Cracks should be avoided in the junction between the cone  16  and the flat disc  24  in order to avoid catching parts when the cone  16  and flat disc  24  are made as two separate elements. Although the flat disc  24  is generally horizontal, it is contemplated that the flat disc  24  may be somewhat inclined. 
     It is contemplated that the cone  16  and the flat disc  24  will be made of the same element and will therefore rotate simultaneously. Of course, these two elements could also rotate independently of one another if so desired. 
     The flat disc  24  encircles the cone  16 , and the cone  16  encircles the central rotating disc  15  which is the reservoir  12 . On the flat disc  24 , the parts will be separated from one another. A quarter inch separation is usually the minimal separation needed for a vision system of a robotic pickup device  18 . This vision system can spot different articles and then pick them up with the robotic device  18 . A very slow speed of rotation or intermittent rotation can be utilized in order to accommodate the robotic device  18 . One or more robotic devices  18  may be positioned adjacent the recirculation system  10  in order to pick up the parts from the flat disc  24 . Parts will be overfed from the reservoir  12  down the cone  16  to the flat disc  24 . In other words, it is contemplated that more parts than will be picked up by the robotic device  18  will be fed from the reservoir  12 . The extra, non-picked up parts will be returned to the reservoir  12  by a return mechanism as will be described below. 
     If parts happen to be touching one another after they slide down the cone  16 , the vision system of the robotic device  18  can reject these parts (i.e., simply not pick them up). Because the system overfeeds parts, then an adequate supply of parts is always available for the robotic device  18  or devices. 
     The flat disc  24  can be made from different materials. For example, if a vision system is used which requires the parts to back-lighted, the flat disc  24  can be transparent or opaque which easily lets light pass therethrough. As can be seen in FIG. 7, there is no drive system beneath the flat disc  24 . Because the flat disc  24  is connected or formed integrally with the cone  16 , it is the cone  16  that is driven. Therefore the area beneath the flat disc  24  is free of any obstructions. A light source or a plurality of light sources can be provided in the area adjacent the robotic device  18  beneath the flat disc  24 . Light from this light source can shine upwardly through the flat disc  24  to provide proper illumination for the vision system of the robotic pick up device  18 . Rather than making the entire flat disc  24  from a transparent or opaque material, this flat disc  24  can have a circular strip provided therethrough which is transparent while the remainder of the flat disc  24  is solid or non-transparent. Alternatively, windows can be provided in the flat disc  24  in order to enable light to pass therethrough. 
     On the other hand, if the articles are not to be back-lit, they can be illuminated from a light source above or adjacent to the robotic device  18 . The light would shine from the light source downwardly onto the flat disc  24  and parts thereon. This light would then reflect upwardly to the vision system of the robotic device  18 . In such an reflective lighting arrangement, the flat disc  24  can be made from a dark material to enhance operation of the vision system for the robotic device  18 . Also, the flat disc  24  could be made from or coated with a fluorescent material. This would enhance operation of the vision system. 
     As noted above, a return mechanism  25  is provided for feeding parts back to the reservoir  12 . These parts can be extra parts which have been overfed from the reservoir  12 , can be parts which are improperly oriented and therefore rejected by the vision system of the robotic device  18 , or simply any other parts which remain on the rotating flat disc  24 . The return mechanism  25  can include a scrapper device  26  which moves the articles from the flat disc  24  to the edge of the cone  16 . This scrapper device  26  can terminate at the cone  16  or can proceed up a portion of the cone  16  in order to move articles towards the reservoir  12 . Because of the steepness of the cone  16 , it is likely that a scraper device  26  alone would be insufficient Therefore, a return belt conveyor  28  is provided. This return conveyor  28  will be at an angle relative to a radial line emanating from the center of the reservoir  12  as seen in FIG.  1 . The return conveyor  28  will be driven to move parts up the cone  16 . At the top of the cone  16 , the articles will simply fall back into the reservoir  12 . In the reservoir  12 , a sensor device can be provided. When it is detected that an insufficient number of parts are provided in the reservoir  12 , this will activate operation of the prefilling device  14 . 
     As seen in FIGS. 1 and 2, this prefilling device  14  can be bulk hopper  30  with a conveyor  32  which simply feeds articles to the reservoir  12 . The articles will drop from the conveyor  32  into the reservoir  12  by gravity. This feeding is a trickle effect whereby articles are simply fed. Because it is not required to lift the articles from the bulk hopper  30  to the reservoir  12 , the overall prefeeding arrangement can be simplified. However, it is possible to use a hopper which is below the height of reservoir  12  whereby a conveyor would be used to lift and drop articles into the reservoir  12 . Other arrangements for filling the reservoir  12  are also contemplated. 
     When discussing the cone  16 , the straight inclined surface thereof shown in FIGS.  2  and  4 - 6  has a straight shape. However, a convex or concave inclined surface could be used, as shown in FIG.  3 . These different shapes can affect the spreading out of articles as they are fed from the reservoir  12  onto the flat disc  24  from the cone  16 . Also, if a concave cone  34  is used as shown in FIG. 3, then contact with the scraper device  26  and/or conveyor belt  28  of the return mechanism which would overlie the concave cone  34  can be ensured. In other words, a gap beneath the conveyor  28  of the return mechanism will be avoided. This will prevent small parts from being trapped and ensure proper feed into the device. Of course, if parts of this are of a sufficient size, then this gap may not be a problem and a straight-shaped cone  16  or convex shaped cone can be used. As seen in FIGS. 1 and 4, the angle of the return conveyor belt  28  of the return mechanism relative to a radial line from the center of the reservoir  12  is such that the bottom of the conveyor belt  28  can be substantially flush with the upper surface of the cone  16 . In this arrangement, the gap is prevented as noted above. 
     The flat disc  24  can have an outer rim  36  if so desired. This outer rim  36  can be an integral one-piece structure with the flat disc  24 . In other words, the cone  16 , flat disc  24  and outer rim  36  can all be a one-piece construction, or these elements can be of different material. If the outer rim  36  is of a one-piece construction with the flat disc  24 , then this outer rim  36  will obviously rotate simultaneously with rotation of the flat disc  24 . However, a stationary outer rim could also be used if so desired. This stationary outer rim would be separate from the flat disc  24  and would serve to prevent articles from falling from the flat disc  24  as it rotates. Because the speed of the flat disc  24  is relatively slow, centrifugal forces are normally not a problem whereby the articles do not tend to roll from the flat disc  24 . This slow rate of rotation is necessary when working with robotic devices  18 . 
     If a stationary outer rim is provided, care should be taken that a gap between the stationary outer rim and the flat disc  24  is avoided in order to avoid catching parts therein. Of course, when handling certain size parts, a small or minimal gap can be of no consequence. With a stationary outer rim, a gap can be provided adjacent the robotic pick up area. In that manner, the robotic device  18  can move the article horizontally from the flat disc  24  rather than having to lift the article. Of course, a little lifting of the article could be carried out but because the stationary outer rim is broken in this section, the robotic device  18  need not lift the article over the stationary outer rim. This can simplify operation of the robotic device  18 . 
     The surface of the flat disc  24  can also be made rough or have suitable configuration in order to accommodate the articles being held. For example, if cylindrical articles will be handled, then grooves can be provided in the flat disc  24  such that the articles will not roll thereby making it easy for the robotic device  18  to pick them up. Other textures can be provided for the outer surface of the flat disc  24 , such as a non-skid, sandpaper-like surface. 
     The cone  16 , on the other hand, is contemplated as having a flat smooth surface in order to allow parts to easily slide down its face. However, grooves for preorienting the parts or other texture can also be provided in the cone  16  as so desired. For example, if cylindrical parts are being handled, grooves can be provided in the cone  16  in order to preorient the parts in a desired direction. 
     With this recirculating system  10 , parts can be separated from one another so that they do not touch. This helps the robotic pickup device  18  properly pick up the articles. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.