Abstract:
A conveyor having an article-diverting device with left-handed and right-handed spirals rotated in the same direction to transport articles in a first direction or in opposite directions to transport articles in a different second direction. The left-handed spirals are arranged alternately and parallel to the right-handed spirals. Rotating all the spirals at the same speed in the same direction in one version of the conveyor passes articles straight across the spirals perpendicular to the axes of rotation of the spirals. Rotating the left-handed spirals opposite to the right-handed spirals diverts the articles atop the spirals parallel to their axes of rotation. In other versions, one set of spirals is constantly rotated and the other set is actuated by geared engagement into and out of rotation in the opposite direction or by raising and lowering into and out of position in contact with articles.

Description:
BACKGROUND 
       [0001]    The invention relates generally to power-driven conveyors and more particularly to article-diverting devices using rotating spirals to transport articles in a selected direction. 
         [0002]    Some conveying applications require that selected articles being conveyed along a main conveying path be diverted off the main path and conveyed away in another direction, while the rest of the articles continue to advance along the main path. But article-diverting devices tend to have a lot of moving parts, which can be difficult to clean and not practical for use in food-handling and other sanitary applications. 
       SUMMARY 
       [0003]    An article-diverting conveying device embodying features of the invention comprises a frame, first and second sets of spirals rotatably supported in the frame, and a motorized spiral drive rotating the first and second sets of spirals. The spirals in the first set are left-handed spirals; the spirals in the second set are right-handed spirals. Both sets have axes of rotation parallel to each other. The motorized spiral drive rotates the first and second sets in the same direction to transport conveyed articles across the spirals in a first direction. The motorized spiral drive rotates the first set and the second set in opposite directions to transport conveyed articles across the spirals in a different second direction. Used in a conveyor, the diverting device receives articles from an infeed conveyor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    These features of the invention, as well as its advantages and other aspects, are described in more detail in the following description, appended claims, and accompanying drawings, in which: 
           [0005]      FIG. 1  is an isometric view of a conveyor having an article-diverting device embodying features of the invention; 
           [0006]      FIG. 2  is an isometric view of the conveyor of  FIG. 1  showing conveyed articles being transported in line; 
           [0007]      FIG. 3  is an isometric view of the conveyor of  FIG. 1  showing conveyed articles diverted to one side; 
           [0008]      FIG. 4  is a schematic block diagram of a motorized spiral drive and auxiliary components used to drive the article-diverting device of  FIG. 1 ; 
           [0009]      FIG. 5  is an isometric view of a conveyor having an elongated article-diverting device as in  FIG. 1  diverting articles to both sides; 
           [0010]      FIG. 6  is an isometric view of a conveyor having an article-diverting device rotated 90° with respect to the infeed and receiving conveyors of  FIG. 1 ; 
           [0011]      FIG. 7  is an isometric view of a conveyor as in  FIG. 1 , but with an article-diverting device having pop-up spirals; and 
           [0012]      FIG. 8  is an isometric view of a conveyor as in  FIG. 1 , but with an article-diverting device having geared, shiftable spirals. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    A conveyor system embodying features of the invention is shown in  FIG. 1 . A conveyor system  10  comprises an infeed conveyor  12 , an in-line receiving conveyor  14 , and a transverse receiving conveyor  16 . The infeed conveyor  12  and the in-line receiving conveyor  14  are shown as belt conveyors advancing in an in-line first conveying direction  18 . The transverse receiving conveyor  16  advances in a different second conveying direction  20 , in this example, perpendicular to the first direction  18 . 
         [0014]    The three conveyors  12 ,  14 ,  16  each abut a different side of an article-diverting device  22 . The diverting device shown is a generally rectangular frame  24  supporting four spirals  26 L,  26 R. The spirals are shown in this example as helical blades formed on the peripheries of screw-or auger-like cylindrical rolls  28 . But in another embodiment, the spiral can be the worm of a corkscrew-like element with shaft-like extensions at each end of the worm forming an axis of rotation. In the version shown in  FIG. 1 , the spirals in a first set  26 L are left-handed spirals, and the spirals in the second set  26 R are right-handed spirals. The left- and right-handed spirals alternate in the frame in this version. The axes of rotation  30  of the spirals  26 L,  26 R are parallel to each other and to the second conveying direction  20  and perpendicular to the in-line first conveying direction  18 . The spirals  26 L,  26 R are rotatably supported in the frame and rotated about their axes of rotation by a motorized spiral drive  32  coupled to the spirals. Conveyed articles ride on the edges of the helical blades or worms at their topmost points. A sensor  34 , such as an optical sensor or a visioning system, is used to detect the presence of an article on the diverting device  22 . The motorized spiral drive selectively rotates each set  26 L,  26 R of spirals clockwise or counterclockwise to pass articles straight through the diverter  22  from the infeed conveyor to the in-line receiving conveyor  16  or to divert the articles onto the perpendicularly disposed receiving conveyor  18 . 
         [0015]    In  FIG. 2 , the motorized spiral drive  32  rotates the set of left-handed spirals  26 L and the set of right-handed spirals  26 R clockwise, when viewed from the viewpoint of a viewer of  FIG. 2 . Because alternate spirals are opposite-handed and rotating in the same direction, the net lateral force on the bottom of an article  36 , such as a tray, in the second direction  20  is zero; and the article is pushed across the spirals  26 L,  26 R in the first direction  18  from the infeed conveyor  12  and onto the in-line receiving conveyor  14 . The article translates without turning about its vertical axis. In other words, the article maintains its absolute orientation whether diverted or not. 
         [0016]    In  FIG. 3 , the motorized spiral drive  32  rotates the right-handed spirals  26 R clockwise and the left-handed spirals  26 L counterclockwise, when viewed from the viewpoint of a viewer of  FIG. 3 . This produces a net force acting along the second direction  20  perpendicular to the in-line first conveying direction  18 . The article  36  is transported across the spirals and onto the second receiving conveyor  16 —again without turning. By rotating each of the spirals in the opposite directions to those shown in  FIG. 3 , articles can be diverted in the direction opposite to the second direction  20  and onto a third conveyor (not shown, but leading away from the fourth side  38  of the diverter  22  opposite to the second conveyor  16 ). 
         [0017]    The spirals  26 L,  26 R may have a rounded outer edge that contacts the bottoms of the articles to minimize scoring and scuffing. To better grip the articles without scoring their bottoms, the spirals, or their edges, may be made of a high-friction material, such as a rubber or elastomeric material. The edges of the spirals at their topmost positions are tangent to the planes of the infeed and receiving conveyors to receive conveyed articles smoothly. 
         [0018]    In the conveying examples illustrated in  FIGS. 2 and 3 , the motorized spiral drive rotated all the spirals at the same speed to achieve 0° or 90° translation of the articles without turning about a vertical axis. But more complex motions of the articles can be obtained by rotating the spirals at different speeds. Those complex motions include diversion along trajectories oblique to the main conveying direction  18  and turning of the articles about vertical axes. 
         [0019]      FIG. 5  shows an elongated article-diverting device  50  receiving the article  36  from the infeed conveyor  12  and selectively diverting the article to one of four transverse receiving conveyors  16 A,  16 B,  16 C, and  16 D. The elongated article-receiving device  50  has four independently actuated divert zones  52 A- 52 D along its length, each corresponding to one of the receiving conveyors  16 A- 16 D. The elongated article-diverting device  50  can be realized as four individual article-diverting devices  12  as in  FIG. 1  arranged in line. An in-line receiving conveyor (not shown) can be positioned at the downstream end of the elongated article-diverting device  54  to receive articles not diverted. When the spirals in a divert zone are rotated in the same direction, articles pass through the zone without being diverted, as in  FIG. 2 . When the left-handed spirals in a divert zone are rotated in a direction opposite to the direction of rotation of the right-handed spirals, articles are diverted, as in  FIG. 3 . And, when diverting articles, the left-handed spirals and the right-handed spirals in the divert zones  52 A,  52 C for the receiving conveyors  16 A,  16 C on one side of the device  50  are rotated opposite to the direction of the left-handed spirals and the right-handed spirals in the divert zones  52 B,  52 D for the receiving conveyors  16 B,  16 D on the opposite side. 
         [0020]    In  FIG. 6 , the article-diverting device  56  is rotated 90° relative to the infeed conveyor  12 , the in-line receiving conveyor  14 , and the transverse receiving conveyor  16  from the article-diverting device  22  of  FIG. 1  so that the axes of rotation  30  of the spirals  26 L,  26 R are parallel to the in-line conveying direction  18 . In the device in  FIG. 6 , the alternating left- and right-handed spirals  26 L,  26 R are rotated in the same direction to divert the articles  36  to the transverse receiving conveyor  16  and in opposite directions to pass the article across without diversion onto the in-line receiving conveyor  14 . 
         [0021]    In the article-diverting device  58  of  FIG. 7 , the left-handed spirals  60 L are the same as those in the article-diverting device of  FIG. 1 , except that they can be constantly rotating. The right-handed spirals  60 R are mounted in vertical slots  62  in the opposite sides of the article-diverting device  58 . The slots  62  extend downward below the level of the left-handed spirals  60 L. An arm  64  is pivotally attached to the ends of the right-handed spirals  60 R and to a linear actuator, such as a pneumatic cylinder  66 , attached at its opposite end to the conveyor frame. A piston arm  68  of the cylinder is selectively extended to raise the right-handed spirals  60 R up to the level of the left-handed spirals  60 L or retracted to lower the right-handed spirals  60 R down to a level below the left-handed spirals  60 L. When the right-handed spirals  60 R are lowered and out of contact with the articles  36 , the rotating left-handed spirals  60 L pass the articles across from the infeed conveyor  12  to the in-line outfeed conveyor  14 . When the right-handed spirals  60 R are raised to the same level as the left-handed spirals  60 L and rotated in the opposite direction to the left-handed spirals, the article-diverting device  58  diverts the articles  36  to the transverse receiving conveyor  16 . 
         [0022]    The article-diverting device  70  of  FIG. 8  has a linear actuator  66  similar to the one in  FIG. 7 . The piston arm  68  is pinned to a rack arm  72  pivotally connected to the ends of right-handed spirals  74 R. The ends of the right-handed spirals  74 R rest in horizontally elongated slots  76  on opposite sides of the article-diverting device  70 . Left-handed spirals  74 L are mounted in fixed positions and always actuated to rotate. The right-and left-handed spirals  74 R,  74 L have gears  78  at one end. When the piston arm  68  of the cylinder  66  is extended, the right-handed spirals  74 R are moved away from the left-handed spirals  74 L and allowed to freely rotate. The articles  36 , driven by the left-handed spirals  74 L, pass right over the article-diverting device  78  from the infeed conveyor  12  to the in-line receiving conveyor  14 . When the piston arm  68  is retracted, the right-handed spirals  74 R are moved toward the left-handed spirals  74 L so that their gears  78  mesh. The rotation of the left-handed spirals  74 L is transmitted through the gears to the right-handed spirals  74 R which are rotated in the opposite direction. The oppositely rotating pairs of opposite spirals divert the articles  36  to the transverse receiving conveyor  16 . 
         [0023]    One version of a motorized spiral drive  32  is shown schematically in  FIG. 4 . The drive includes a controller  40 , such as a programmable logic controller or other computer, receiving a signal  42  from the sensor  34  indicating the presence of an article on the diverting device  22 . The controller then decides whether the article is to be transported straight through in the first direction or diverted in the second direction. The controller sends motor control signals  44 L,  44 R to each of the two motors  46 L,  46 R. The motor control signals include information that controls the direction of motor rotation and may also control motor speed. The motors&#39; shafts are coupled to the spirals  26 L,  26 R by drive trains  48 L,  48 R. Alternatively, a single motor, coupled through separate drive trains with reversers controlled by the controller, can be used. Or each spiral, instead of each set of spirals, could be controlled independently. And, of course, a diverter with more than four spirals could be used. When used with the diverting devices  58 ,  70  of  FIGS. 7 and 8 , the controller sends an actuator signal  49  to the actuator  66  to actuate the right-handed spirals  60 R,  74 R to selectively divert the articles. So, as these few examples indicate, the scope of the claims is not meant to be limited to the details of the exemplary versions.