Abstract:
A method of processing toothbrushes includes supplying a plurality of toothbrushes with tufts of bristles attached to heads of the toothbrushes. Similar portions of each of the toothbrushes differ in color from each other. A color of the portion of each of the toothbrushes is determined. The toothbrushes are reorganized according to the determined color.

Description:
FIELD OF THE INVENTION 
     The invention relates generally to the field of oral care, and in particular to toothbrushes. More specifically, the invention relates to a method and apparatus for processing toothbrushes. 
     BACKGROUND OF THE INVENTION 
     In a prior art method of making toothbrushes, toothbrush handles are first typically formed in an injection molding machine. A common type of handle is made in a two shot mold and has a plastic main body with rubber overmolded on portions of the plastic body to aid in gripability of the handle. 
     Referring to  FIG. 1 , after the handles are made they are put into a handle loader  10  at a stapling/finishing machine  12 . A hopper at loader  10  will typically contain handles having a number of different colors. For example, all of the handles might have white plastic main bodies, but some of the handles will have red overmolded portions while other handles will have green, blue, yellow or purple overmolded portions. The handles are in a random jumble in the hopper. 
     Handle loader  10  automatically removes handles from the hopper and introduces the handles into stapling/finishing machine  12  where bristle tufts are stapled to a head of each handle. The bristle tufts are then trimmed and end-rounded in the stapling/finishing machine to complete production of the toothbrush itself. 
     The finished toothbrushes exit the stapling/finishing machine single file and are moved by a conveyer belt  14  to a tray loader  16 . At the tray loader the toothbrushes are placed into trays that each hold a two dimensional array of toothbrushes. These trays are then brought to packaging machines which place the toothbrushes in packaging for shipment to stores. 
     A problem exists in that the handles are randomly taken by handle loader  10  from the hopper and introduced into stapling/finishing machine  12 . This results in a non-uniform color mixture of toothbrushes being produced. For example, three toothbrushes in a row might exit stapling/finishing machine  12  that all have red overmolded rubber portions. This can cause problems because the retailers prefer an even color mixture of toothbrushes. Further, consumers buying club packs which contain a large number of toothbrushes desire an even color mixture so family members can tell their toothbrushes apart. One way of addressing this problem is to manually reorganize the toothbrushes by color, but this is labor intensive and not a desired solution. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, a method of processing toothbrushes includes supplying a plurality of toothbrushes with tufts of bristles attached to heads of the toothbrushes. Similar portions of each of the toothbrushes differ in color from each other. A color of the portion of each of the toothbrushes is determined. The toothbrushes are reorganized according to the determined color. 
     According to another aspect of the invention, an apparatus for processing toothbrushes includes a removal element for removing a toothbrush from a supply of toothbrushes. A color sensor determines a color of a portion of the removed toothbrush. A first buffer receives from the removal element the removed toothbrush and other toothbrushes having the same colored toothbrush portion as the removed toothbrush. 
     These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiment and appended claims, and by reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic illustration of a prior art toothbrush processing apparatus; 
         FIG. 2  is a schematic illustration of a toothbrush processing apparatus according to the invention including a color sorter; 
         FIG. 3  is a perspective view of the color sorter of  FIG. 3 ; 
         FIG. 4  is a partial sectional view of  FIG. 2  taken along the lines  4 - 4 ; and 
         FIG. 5  is a perspective view of a portion of a color sorter. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Beginning with  FIGS. 2-4 , the elements  10 ,  12 ,  14  and  16  are substantially the same as described with respect to  FIG. 1 . However, a color sorter  17  has been added to the system. A supply of toothbrushes exit stapling/finishing machine  12  single file and are moved by a conveyer belt  14  in the direction of an arrow  18 . A mechanical stop stops a lead toothbrush adjacent a removal element  20 . An optical sensor detects the presence of a toothbrush at the mechanical stop and signals removal element  20  to remove the toothbrush from conveyor  14 . The removal element will be discussed in more detail below. 
     A color sensor then determines a color of a portion of the removed toothbrush, for example the rubber overmolded portion of the handle. Once the color is determined, removal element  20  moves the removed toothbrush over one of five buffer conveyors  22 A-E ( 22 A being the lowest conveyor in  FIG. 2 ). For example, if the color of the rubber is determined to be red, removal element  22  is moved over conveyor  22 A. The removal element then deposits the toothbrush onto conveyor  22 A. 
     The other buffer conveyors  22 B-E are designated to respectively hold toothbrushes having different colors. For example, conveyor  22 B would hold toothbrushes with yellow rubber portions, conveyor  22 C would hold toothbrushes with green rubber portions, and so on. The number of conveyor buffers used are set to match the number of different colored toothbrush portions being produced by stapling/finishing machine  12 . Each toothbrush produced by stapling/finishing machine  12  is placed by a color sort into one of buffers  22 A-E. 
     Once a toothbrush is placed on one of conveyors  22 A-E, an optical sensor detects this event and signals for that conveyor to be actuated to move the toothbrush in the direction of arrow  18 . Another optical sensor detects that the toothbrush has been moved below a return element  24  and signals for the conveyor to be turned off. This parks the toothbrush below the return element and frees up the space below the removal element for the next toothbrush to be placed on that conveyor buffer. 
     Return element  24  is similar to removal element  20  except that it takes toothbrushes one at a time out of buffers  22 A-E and places them back onto conveyor  14  downstream from the mechanical stop mentioned above. The removal element is instructed to remove toothbrushes from buffers  22 A-E in a designated sequence in order to feed toothbrushes to tray loader  16  in a desired color sequence. 
     Removal element  20  and return element  24  have substantially the same parts. These parts will be described in terms of return element  24 . A pick-up head in the form of a pneumatically operated gripper  26  is attached to a pneumatic vertical actuator  27 . The gripper has jaws which can move towards each other or away from each other in the direction of a double-headed arrow  28  to respectively grab or release a toothbrush. Portions of side walls  29  of conveyor belt  14  are removed so that gripper  26  can grip a toothbrush. 
     Vertical actuator  27  moves the pick-up head up or down in the direction of a double-headed arrow  30  to move a grasped toothbrush away from one of buffers  22 A-E and towards conveyor belt  14 . A linear actuator controlled by a servo drive  32  moves vertical actuator  27 , and thus gripper  26  back and forth in the direction of a double-headed arrow  34 . In this way, toothbrushes can be moved between conveyor belt  14  and buffer conveyors  22 A-E. 
     The following example will assist in understanding this embodiment of the invention. Assume R=Red, B=Blue, G=Green, Y=Yellow and P=Purple. A sequence of toothbrushes coming out of stapling/finishing machine  12  might be in the order RRBGPRYPYYPGBBG. After color sorter  17  reorganizes the toothbrushes, they would continue onto tray loader  16  in the order RGPYBRGPYBRGPYB. This would provide a perfect color mix of toothbrushes Of course, any designated color sequence can be obtained with this system, such as RRBBGGYYPP. 
     It may happen that, for example, five red toothbrushes come into the color sorter in a row. In this case, four of the five toothbrushes would get buffered on their designated buffer conveyor. These extra brushes get stored to the left in  FIG. 2  on their conveyor. When return element  24  later needs a red toothbrush and none is available under removal element  24 , the red conveyor is run in the reverse direction (i.e. opposite to arrow  18 ) to move one of the buffered red brushes under return element  24 . 
     This buffering system can be described as a last in first out (LIFO) system. Each conveyor buffer  22 A-E can store up to 10 brushes. In the unlikely event that the capacity for a specific buffer conveyor is exceeded, the extra brushes will fall off the left end of the conveyor into a tote. These extra brushes are either manually reintroduced to their conveyor at a later time when there is room, or are manually introduced to tray sorter  16 . 
     A programmable Logic Controller (PLC) receives input from the optical sensors for determining toothbrush position and from the color sensor for determining the color of a portion of each toothbrush. The PLC directs operation of conveyor  14 , buffer conveyors  22 A-E, removal element  20  and return element  24 . 
     Turning to  FIG. 5 , a portion of a color sorter  36  is shown which has only four buffer conveyors  38 A-D. Toothbrushes  40  are shown on the conveyors. A toothbrush  42  has just been placed on conveyor  38 B by the removal element. Conveyor  38 B would now be actuated to move the two toothbrushes on this conveyor to the left until toothbrush  42  is located where a toothbrush  44  is currently located in  FIG. 5 . This effectively moves toothbrush  42  from a removal zone  46  to a return zone  48 , thus freeing up the entire removal zone for receipt of a toothbrush of any of four colors from the removal element. 
     Now assume return element returned a toothbrush  50  from buffer conveyor  38 A to conveyor  14 . Buffer conveyor  38 A would now be operated to move a toothbrush  52  to the right and park toothbrush  52  in return zone  48 . This demonstrates that this is a LIFO system. 
     The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.