Patent Publication Number: US-5529191-A

Title: Machine for sorting articles according to a characteristic thereof

Description:
BACKGROUND OF THE INVENTION 
     The invention disclosed herein pertains to a method and apparatus for removing articles such as glass and plastic bottles from containers such as boxes, cartons and crates and sorting the articles according to their color or other characteristics. 
     For convenience, glass and plastic bottles and other article configurations that can be processed with the apparatus will be called by the convenient generic term &#34;bottles&#34; herein. 
     German Patent DE 24 34 183 C3 discloses the concept of removing bottles from conveyed containers and sorting the bottles according to their colors using a scheme wherein several unpacking machines are arranged in series. Each machine is provided with sensors or detectors that are sensitive to and respond to a single color. The first machine withdraws bottles of a first color, such as clear bottles, from each container as it is conveyed past the first machine. The container with bottles having colors other than clear, such as brown and green, remaining in the container, after the first machine are conveyed to the second machine where the bottles of one of the remaining colors are withdrawn and then the container is conveyed to the next machine and so on until bottles of all colors are removed from the containers and are sent along individual paths. 
     There are two major problems with the preexisting approach outlined above. One is that an individual machine is needed for each bottle color or other distinguishing article characteristic. Thus, an exceedingly large investment must be made in machines. The other problem is that the series of machines take up a lot of floor space by themselves and so do the additional conveyors that are needed with this approach. This might even require a larger building than might otherwise be required if the single multi-color bottle separating machine disclosed herein were installed. 
     SUMMARY OF THE INVENTION 
     An objective of the invention is to provide a machine that can remove articles such as bottles from conveyed containers, such as boxes, cartons and crates, sequentially according to their respective colors or other characteristics and can deposit the bottles on individual receiving stations from which they may be collected or otherwise conveyed away. 
     According to one implementation of the invention, containers filled with variously colored bottles are conveyed to the new bottle unpacking and color discriminating machine. The machine comprises a carrier member, that is, a rotor that rotates about a horizontal axis. The rotor has mounted to it a plurality of articulated lever systems which are equiangularly spaced about the horizontal rotational axis of the rotor. Each lever system has a bottle gripper head pivotally connected to it. Each gripper head has an equal number of selectively engageable and releasable bottle grippers mounted to it. As the rotor rotates about a horizontal axis, each gripper head is maintained in a horizontal attitude on its pivot connection to the articulated lever systems. The gripper heads are transported concurrently along a closed loop irregular or non-circular orbit or path that is coincident with a vertical plane in the preferred embodiment. 
     Each gripper on a gripper head has a detector affiliated with it that produces an output signal if the bottle that is positionally corresponding to the gripper and that is in view of the detector has a color or other unique characteristic to which the detector is sensitive or tuned. Bottle color sensors affiliated with grippers are known from German DE GM 93 114 112.2. 
     For convenience, the articles to be sorted will be called bottles herein and for demonstration purposes the bottles will be sorted on the basis of their respective colors. It should be understood, however, that the articles are not necessarily restricted to bottles and characteristics other than color may be utilized as a basis for sorting. 
     As the containers, filled or partially filled with bottles of various colors arrive at the bottle pick up station on an infeed conveyor, the containers are in phase or coincidence with one of the gripper heads that is following its closed loop orbital path. The grippers on that head engage and lift all of the bottles from the container for carrying them to a first selective release station. An electronic controller on a gripper head or some other location has stored data indicative of which grippers hold bottles of which color. This information is obtained through signals transmitted from the respective color sensitive detectors. The whole group of bottles which the gripper head is now carrying are transported along a segment of the orbital path to a first release station where the controller on the gripper head triggers all grippers holding bottles of only one of the colors to release the bottles. Bottles of other colors retained by the head then traverse through successive release stations at which bottles of the same color are released. 
     A preliminary bottle characteristic selecting machine can be advantageously positioned in advance of the container infeed zone of the aforesaid machine. The preliminary machine can have its grippers adapted with sensors that sense bottles that have characteristics that disqualify them for use in the particular production line. For example, some bottles in incoming containers may have improper shoulder contour, height, contamination, damage and so forth. Any odd bottles that could not be assigned to any one of the bottle color release stations can remain on the infeed conveyor for being conveyed away. The sensors or detectors and controls of the preliminary inspection machine grippers can be mutually interconnected with the same on the heads that are involved in color selection. 
     Infeeding bottle transport containers, withdrawing bottles from containers, depositing bottles at the dedicated bottle color release stations and conveying away colored bottles from release stations is continuous in the new machine. Thus, when a gripper head releases bottles of one of the colors at the last release station in its orbital path a new cycle is started beginning with that same head withdrawing all bottles from a container on the infeed conveyor. 
     Improved bottle processing speed can be achieved with a machine having grippers continuously guided in a closed loop path in the same direction which can lie in a horizontal or vertical plane. This has the advantage of allowing a continuous supply of bottle filled transport containers and a continuous release of bottles at release stations. A further advantage is that the continuous operation allows use of gripper heads that extend out in the direction of conveyor travel. When the gripper heads travel in a horizontal plane, the bottle release stations are also positioned in a horizontal plane and can be arranged offset and behind each other along the plane of travel. It is possible to arrange the bottle release stations offset in height as in a staggered or stepwise fashion. 
     When the gripper heads are guided in a path which lies in a vertical plane, the conveyor leading from the individual bottle release stations can be arranged in parallel above the conveyor for the infeed of conveyors and in alignment with the same. When conveyors are arranged in this way, very good access to all important areas of the machine is available to service personnel. 
     How the foregoing objectives and features are achieved and implemented will be more evident in the ensuing more detailed description of a preferred embodiment of the invention which will now be set forth in reference to the drawing. 
    
    
     DESCRIPTION OF THE DRAWING 
     The single FIGURE is a schematic side elevational view of the essential features of the new machine. 
    
    
     DESCRIPTION OF A PREFERRED EMBODIMENT 
     The bottle separating machine depicted in the drawing comprises a vertically oriented mounting plate 14 which is secured in a fixed position. A rotor 13 is mounted to mounting plate 14 and is driven continuously in rotation about a horizontal axis. The machine is provided with four gripper heads each of which supports a group of grippers 3. Each gripper head 4 is pivotally connected to a lever 18 of an articulated lever system including levers 15, 16, 17 and 18. Levers 15 and 16 are pivotally connected to one of the arms of rotor 13. Stationary vertical support plate 14 is equipped with two cam grooves 19 and 20. A cam follower roller 15&#39; is journaled for rotation on lever 15 and is compelled to follow cam groove 20 as the rotor 13 rotates. Similarly, lever 16 is provided with a cam follower roller 16&#39; which is compelled to follow cam groove 19 when rotor 13 is driven rotationally in the direction indicated by the arrow near the axis of rotation of rotor 13. Cam grooves 19 and 20 are configured so that the gripper carrying heads 4 describe a closed loop non-circular irregular path of travel somewhat like the path defined by the closed loop 21. The gripper heads 4 are held in horizontal position by means of a drive mechanism, not shown, driving one complete rotation of the rotor 13. 
     Each gripper 3 has a color sensor 5 affiliated with it. Each carrier head 4 has a control mechanism 7 which is connected with sensors 5 and controls the gripping function of grippers 3 in accordance with bottle color. Control mechanism 7 is also connected with a remote position indicator, not shown, which indicates the instantaneous rotational position of rotor 13. 
     Bottle containers such as cases 2 filled with unsorted empty bottles are fed to the machine on an infeed conveyor 8 which runs in the horizontal plane. The incoming bottle container coming in on infeed conveyor 8 is having all of the bottles contained in it gripped by the gripper carrier head 4 above it at a station identified by the roman numeral I. No bottle color discrimination nor selection occurs at station I. The direction of travel of infeed conveyor 8 is indicated by the arrow marked thereon. In this embodiment, there are three horizontal distinctively colored bottle outfeed conveyors 9, 10 and 11. Horizontal outfeed conveyors 9, 10 and 11, have zones, respectively, designated as release stations II, III and IV. Note from the indication by the arrows, conveyor belts 9 and 10 translate to the left and conveyor belt 11 translates to the right. Unsorted bottle container infeed conveyor 8 and outfeed conveyor belts 9, 10 and 11 are driven translationally continuously and in synchronism with rotor 13 of the machine. The cam grooves 19 and 20 in vertical plate 14 which determine the irregular orbital path 21 are of such configuration that the gripper heads 4 and their grippers 3 are each executing a horizontal component of motion at release stations II, III and IV which corresponds with conveyor speeds so there is no drag at any of the release stations of the bottles being released on the outfeed conveyors. 
     An operating cycle of the machine begins with a gripper head 4 descending so that all of its grippers 3 can engage all bottles present in a container which is presently conveyed to bottle pick up or infeed station I. As indicated, conveyor 8 and the container 2 thereon and the gripper head 4 are all moving at the same velocity at the time the bottles are engaged by the grippers on the gripper head. As soon as the grippers descend to the height of the bottle mouths, all grippers 3 of head 4 are actuated to the gripping mode by control device 7 so that all bottles in the container 2 can be taken from it and transported toward the first container release station II. During this operation, the color of each individual bottle is determined by the respective sensors 5 associated with the gripper elements 3. When the first bottle release station II is reached, only those grippers 3 of head 4 are put in the release mode which have been sensed as holding bottles of a particular color. For example, only clear transparent bottles will be released at station II. All other grippers 3 remain in the gripping mode after the clear glass bottles, for example, are released at bottle release station II. The same gripper carrying head for moving bottles other than clear glass bottles departs from station II on conveyor belt 9 and is guided by the cam grooves to the second bottle release station III. At station III, control device 7 may cause, for example, release of all green bottles onto outfeed conveyor belt 10 by virtue of the fact that only grippers holding bottles of that particular color are switched to the release mode at station III. Finally, in this embodiment, residual bottles of the remaining color are carried over the top of loop 21 for descending to release station IV where the controller 7 effects release of the bottle, which, for example, may be colored brown. 
     The differently colored bottles, after arriving at their respective release stations II, III and IV are conveyed on conveyors 9, 10 and 11 to, for example, separate destinations such as to deposit the sorted bottles in cases. One of the conveyor belts may lead to a bottle washing machine or a bottle filler line.