Abstract:
Disclosed is a method and an apparatus for distributing articles using a mobile device equipped with one or two ejectors, capable of removing the required number of distributed articles from a conveyor sequentially, into collection containers in designated collection zones located on one or both sides of the conveyor. These zones may be defined according to the size of collection bins or packing boxes used, allowing the distribution of articles in a wide range of sizes. This method allows the building of a very flexible and very economical distributing conveyor systems, due to the fact that only one mobile device is used instead of a number of fixed diverting stations mounted on one or both sides of the conveyor.

Description:
BACKGROUND OF INVENTION  
         [0001]    The invention relates to the distribution of articles from a conveyor system.  
           [0002]    At a present time articles are distributed or sorted by the systems that employ a multitude of diverting or ejecting devices located along the conveyor which direct the desired articles into designated collection containers. Such systems, usually custom made for predefined articles and sizes of collecting containers are very expensive. Due to the cost only the larger distribution companies can afford this type of automation.  
           [0003]    In case of distributing articles in groups of the same type, where sorting the articles of various type is not a required function, such an expensive and complex system may be replaced with a simpler, more economic one. The present invention utilizes one mobile device with one or two ejectors mounted on it, capable of removing the required number of distributed articles from a conveyor sequentially into container in designated collection zones located along the conveyor.  
         SUMMARY OF INVENTION  
         [0004]    The general idea of the invention is a method of distributing articles placed on the conveyor using a mobile apparatus able to move along or upon a conveyor and able to remove the articles from the conveyor into containers in designated collection zones.  
           [0005]    Objects and Advantages: Several objects and advantages of the invention are: The ability to build extremely cost effective distributing conveyor systems due to the usage of only one mobile device to remove articles from the conveyor.  
           [0006]    The ability to build flexible distributing conveyor systems permitting a wide range of articles and collection container sizes, due to software definable length and location of the collection zones.  
           [0007]    The ability to upgrade existing conveyor systems by converting them to distributing conveyor systems. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0008]    In the drawings, closely related figures have the same numbers but different alphabetic suffixes.  
         [0009]    [0009]FIG. 1A and FIG. 1B respectively, show side and top schematic views used to explain the principals of the present invention.  
         [0010]    [0010]FIGS. 2A to  2 C respectively, show top view, side view, and cross-section of employed conveyor in the line  1 - 1 , with the rails supporting and powering the mobile distributing apparatus.  
         [0011]    [0011]FIGS. 3A to  3 B respectively, show top view and side view of a mobile distributing apparatus in preferred embodiment of the present invention mentioned in the claim 3.  
         [0012]    [0012]FIG. 4 shows a block diagram of the circuit controlling the distributing apparatus shown in FIGS. 3A and 3B.  
         [0013]    [0013]FIG. 5 shows a software flowchart of a program for a programmable logic controller  61  (PLC), shown in FIGS. 3A, 3B and FIG. 4.  
         [0014]    [0014]FIG. 6 shows a three dimensional rendering of the preferred embodiment of the present invention.  
         [0015]    [0015]FIG. 7 shows top and side view of the embodiment mentioned in the claim 4.  
         [0016]    [0016]FIG. 8 shows top and side views of the embodiment mentioned in the claim 5.  
         [0017]    [0017]FIG. 9 shows top and side views of the embodiment mentioned in the claim 6. 
     
    
     DETAILED DESCRIPTION  
       [0018]    Herein, there follows a description of a preferred embodiment of a method and an apparatus for distributing the articles by ejecting them from a conveyor. In this description downstream means the direction of run of the conveyor while upstream means the opposite direction. Referring to FIGS. 1A, 1B and FIG. 6, a conveyor  16  is shown with a mobile apparatus  13 , comprising carrier  14  and ejectors  15 , presented in the form of moving arms. Articles to be distributed  12  are placed on the powered conveyor belt  26  (FIGS. 2A and 2C) and approaching the apparatus  13 , stopped in a designated collection zone. As soon as a brake-a-beam sensor  48  (FIGS. 3A and 3B) sees the article  12 , the pre-calculated time delay begins to be counted. Upon conclusion of the time delay the ejector  15  ejects the product out of the conveyor  16  so that it falls into the collection container  11 , at the designated collection zone. If there are more articles to be distributed in this zone, the arms  15  return to the previous position and repeat the process. In case the article to be ejected is on the opposite side of the conveyor  16 , the arms  15  remain in their last position and ejects the article when it arrives. In case the next desired collection zone is one or more zones downstream along the conveyor  16 , the apparatus  13 , using its own propulsion moves downstream faster than the conveyor&#39;s belt  26  (FIGS. 2A and 2C), stops in the desired collection zone, sets the ejectors  15  to the opposite side of the conveyor  16 , where the zone is located, and distributes the desired number of articles. This process repeats until all articles  12  are distributed. Additional articles placed on the conveyor (if any) are collected in the last collection box placed in the last collection zone. After this, the mobile apparatus  13  moves upstream until it reaches the initial collection zone where the front end sensor  49  (FIGS. 3A and 3B), detects the front limit magnet  27  (FIGS. 2A and 2B), and stops the apparatus  13 . The length of the collection zones is flexible and defined by the user to accommodate various sizes of collection bins or shipping boxes. The mobile apparatus  13  may move independently along the conveyor, on the conveyor body, or even run on the moving conveyor&#39;s belt.  
         [0019]    Referring to FIGS. 2A, 2B, and  2 C a preferred embodiment is shown with the supporting plastic rails  21  mounted on both sides of the conveyor body  25  with screws  24 . Each rail  21  is holding the chain  22  in the slots located on the top. The bare braided copper wire  23  is placed under each chain.  
         [0020]    Referring to FIGS. 3A and 3B, top and side view of the apparatus  13  (FIGS. 1A and 1B) is shown in detail. The brass tooth wheels  33  of the apparatus run on chains  22  (FIGS. 2A and 2C). The gear teeth of the wheel  33  are detected by a sensor  64  mounted on the bracket  58  and held by screws  59 . The tooth count is used to determine the position of the apparatus  13  over the conveyor  16  (FIGS. 1A and 1B). The wheels  33  are mounted on steel axis  41 , held by two brass bushings  36 , mounted in plastic bushing holders  35 , and secured with screws  63 .  
         [0021]    The apparatus is powered with low DC voltage by an external power supply connected to two heavy braided bare copper wires  23  (FIG. 2C), contacting wheels  33  through the links of the chain  22  (FIGS. 2A and 2C). The supply voltage is collected by two brushes  54  from the brass rings  52 , which are mounted on two of the four axis  41 . They are located on each side of the apparatus and secured with set screws  53 .  
         [0022]    The brushes  54  are equipped with the springs  55  and connected with wires  37  to the programmable logic controller (PLC)  61 . The remaining two axis  41  are coupled with the gear box  32  of the direct current electric motor  31 , with the three piece jaw coupling  42 . The rubber element between the jaws provides the necessary electrical isolation between the axis on both sides. The steel washers  38  are applied between brass rings  52  and plastic brackets  35  as well as between the jaw clutches  42  and plastic brackets  35 .  
         [0023]    The ejecting mechanism of the apparatus consists of two electromagnetic coils  45  being a type of electric rotary actuators mentioned in the claim  3 . This coils are wired to the PLC  61 . Each coil  45  is mounted on the holder  44 , and equipped with an ejecting brush  47 . The brush  47  is mounted on an aluminum arm  46  and connected to the coil shaft with an aluminum bracket  62 . The apparatus  13  (FIGS. 1A and 1B) is quipped with a front limit sensor  49  and an end limit sensor  51 . Both sensors  49  and  51  are magnetic type. Sensor  49  detects the magnet  27  mounted on the front (FIGS. 2A and 2B) while the sensor  51  detects the magnet  28  mounted on the end (FIGS. 2A and 2B) of the conveyor  16  (FIGS. 1A and 1B) thus limiting the range of the movement of the apparatus on the conveyor. Articles to be distributed  12  (FIGS. 1A and 1B) arrive on the conveyor  16  and are detected by a see-through sensor  48 , mounted on the bracket  57  and attached to the side bars  34  with screws  39 .  
         [0024]    Referring to FIG. 4 the block diagram of the apparatus  13  (FIGS. 1A and 1B) is shown. Block  61  (FIGS. 3A, 3B, and  4 ) is a digital controller, which may be a programmable logic controller (PLC), or another electronic control circuit based on a microprocessor. Methods for programming such devices are conventional and known to those skilled in the art, however, a flowchart of such a program is shown in FIG. 5 and described further. The PLC receives signals from the see-through type sensor  48 , the front limit sensor  49 , the end limit sensor  51 , and the gear tooth sensor  52 . Both coils  45 , which drive the ejector arms, are connected to the power outputs of the PLC  61 , as well as electric motor  31 . The number of articles to distribute, and the number of gear teeth the apparatus  13  (FIGS. 1A and 1B) is to travel to reach the desired collection zone are transmitted from the computer system  71  via radio frequency data link  56  equipped with the antenna  62 . The link transmits this data to the PLC as well as receives the confirmation from the PLC.  
         [0025]    [0025]FIG. 5 presents the flowchart of a PLC program. The PLC receives data from the computer system and check if the apparatus is in the desired position on the conveyor, i.e. in the desired collection zone. In case it is not, the motor moves the apparatus downstream at the speed higher than the movement of the belt. The PLC counts pulses from the gear tooth sensors until they reach the number demanded by the computer system. As soon as the apparatus is in position it sets the ejecting arms to the opposite side of the desired collection zone and waits for the article to arrive on the conveyor belt. The arriving article brakes the beam of the article sensor  48  (FIGS. 3A, 3B and  4 ) and starts the preset time delay. This delay is long enough to allow the article to be entirely within the range of the ejecting arm. When the delay expires the arm ejects the article and the program checks if all articles were ejected in this collection zone. In case of more articles the arms withdraw to their previous position and wait for the next article to arrive. If there are no additional articles to be ejected, the arms remain in their last position and the program checks to see if there are any articles to be ejected in the collection zone on the other side of the conveyor. The program checks if the arms are in their proper position, sets them if necessary and ejects the articles. In the event that there are no articles to be ejected on the opposite side of the conveyor, the apparatus is moved to the next desired location and distributes the articles there, until the apparatus reaches the end limit. From this location the apparatus runs upstream the conveyor until it reaches the front limit and the distribution process may be repeated for other types of articles.  
         [0026]    The second preferred embodiment mentioned in the claim  4  is similar to the first embodiment shown in drawings FIG. 1 to FIG. 6 except the means of ejection which are arranged in the form of a triangular diverter  81 , driven transversally to the conveyor  16  by a linear actuator  82  as shown in FIGS. 7A and 7B.  
         [0027]    The third preferred embodiment mentioned in the claim  5  is similar to the first embodiment shown in drawings FIG. 1 to FIG. 6 except the means of ejection which are arranged in the form of pivoting triangular diverter  81 , pivoting on the shaft of a rotary actuator. Drawings FIG. 8A and FIG. 8B show two electrical coils  45  in the configuration where they work against each other as an example of such actuator. This may be accomplished by any other type of rotary actuator as well.  
         [0028]    The fourth preferred embodiment mentioned in the claim  6  is similar to the first embodiment shown in drawings FIG. 1 to FIG. 6 except the means of ejection which are arranged in the form of pivoting triangular diverter  81 , driven by a linear actuator  82 , as shown in FIG. 9A and 9B.  
         [0029]    The present invention is not limited to the above mentioned embodiments. Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative devices shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.