the invention is described next by way of an example . fig1 shows the basic structure of a mixing system embodying this invention including a transporting device 100 for transporting unseasoned or unflavored food items , a weighing device 200 for portioning or partitioning the food items transported by the transporting device 100 into batches of a specified quantity for filling one bag , a mixing device 300 for applying additives such as flavorings to each batch of the food items , a packaging device 400 for packaging the flavored or seasoned food items , a sorting device 500 for eliminating from the production line defective products caused by an error in weighing or application of flavoring , a packing device 600 for packing packaged products in a box , and a control unit 700 for not only controlling each of the devices 100 , 200 , 300 , 400 , 500 and 600 but also coordinating their operations . the transporting device 100 is for receiving food items from a frying machine ( not shown ) and transporting them to the weighing device 200 . a vibrating feeder 110 is provided at its downstream end for supporting thereon the transported food items . when a supply - requesting signal s 1 is received from the weighing device 200 , the vibrating feeder 110 vibrates for a specified length of time to deliver the food items thereon to the weighing device 200 . the weighing device 200 is for receiving the food items delivered by the vibrating feeder 110 and producing batches of the food items each for filling one bag as a finished product . it has a dispersion feeder 210 at the top , and when the amount of the food items thereon becomes too small , it transmits the aforementioned supply - requesting signal s 1 to the vibration feeder 110 . when a discharge - requesting signal s 2 is received from the mixing device 300 , the weighing device 200 opens a gate 223 of its timing hopper 220 to discharge a batch of the food items m of a specified amount which have been held therein . thereafter , the weighing device 200 starts its weighing operations to portion another batch with a specified quantity or weight and discharges this new batch into the timing hopper 220 which has just been emptied and is waiting for the next discharge - requesting signal s 2 . the purpose of this weighing device 220 is to portion the food items and to discharge these portioned batches . the portioning need not be in terms of weight but may be in terms of volume or number . in the case of a snack food of the type having individually different sizes , it is convenient to use a combinational weigher such as described in u . s . pat . no . 5 , 757 , 866 issued may 19 , 1998 , adapted to use a dispersion feeder 210 to distribute food items supplied at the top center among a plurality of weigh hoppers , to measure the individual weights of the items in these weigh hoppers , and to select a combination of the weigh hoppers such that the total of the weights of the items in the selected combination of the weigh hoppers will be of a specified magnitude . with a weigher of this type , even irregularly shaped items can be portioned accurately . if an error is committed in the weighing , the weighing device 200 transmits an error signal s 3 to the control unit 700 . upon receiving an error signal s 3 , the control unit 700 transmits a stop signal s 4 to the mixing device 300 to stop dispensing additive ( s ) to the error batch . thus , if a batch with an incorrect quantity is discharged , this batch is not flavored and may be collected to be used for producing a differently flavored product or be recycled for use with the same flavor . fig3 shows an example of the mixing device 300 , structured such that a plurality of small mixing drums or chambers t 1 - t m will rotate along a closed path around a vertical axis of rotation o and pass beneath the timing hopper 220 at a supply location 350 to a pair of additive supply locations 352 , 354 at each of which a respective additive can be dispensed and to a discharge location 356 . during this movement , each drum rotates around itself . explained more in detail with reference to fig4 a , the drums t 1 - t m are attached to the tips of arms 321 extending radially from the axis of rotation o such that as the central rotary shaft along the axis of rotation is rotated , the drums t 1 - t m rotate horizontally together with the arms 321 , as indicated by arcuate arrows . each arm 321 carries on its end distal from the axis of rotation o a rotary member 321 b adapted to rotate around its direction of extension . as shown in fig4 b , the rotary member 321 b is connected to a fixed annular rack 323 and a pinion 322 and is supported on a frame 327 such that , as the arms 321 rotate horizontally around the axis of rotation o , the pinion 322 engaging with the fixed rack 323 rotates along the rack 323 . as a result , the rotary member 321 b which is integrally formed with the pinion 322 , as well as the associated one of the drums t 1 - t m , will rotate around the axis of rotation of the arm 321 . the rack and pinion system is constructed so that the sliding gate 324 of each drum is correctly positioned at each location 350 - 356 . each of the drums t 1 - t m has an opening 325 , provided with a sliding gate 324 biased by a spring ( not shown ) in the direction of closing it . when one of the drums t 1 - t m reaches the foodstuff supply position 350 for receiving unseasoned food items ( the position of drum t 1 in fig3 ), its opening 325 is at an upwardly facing position , as shown in fig5 a , and the sliding gate 324 is opened . at the same time , another of the drums ( t m in the example of fig3 ) which is at a discharge position 356 has its sliding gate 324 opened with its opening 325 facing in the vertically downward direction , as shown in fig5 c . at the positions 352 , 354 , the drums will have their gates 324 open with the openings 325 facing upward to receive an additive ( if appropriate ). at other positions , the drums t 1 - t m have their sliding gates 324 closed , as shown in fig5 b , sealing inside both a batch of food items m and additive ( s ). the opening / closing process can be controlled by a simple cam system ( not shown ). as shown in fig5 , for flavoring additives , there are protrusions 326 inside the drums t 1 - t m serving to stir and mix the food items and the seasoning material s together as the drums t 1 - t m rotate . this results in the food items being uniformly coated with the flavoring . at each position 352 , 354 , a respective dispenser 310 is located , each additive dispenser 310 being controlled by a common control device 330 . each dispenser 310 ( fig2 ) includes a charge hopper 311 for storing the flavoring , tokens or other additive , a vibratory feeder 312 for transporting the additive inside the charge hopper 311 to its front end little by little , a weigh hopper 313 for receiving the additive s from the vibratory feeder 312 and weighing the received additive and a weight sensor 314 for measuring the weight of the weigh hopper 313 . the control device 330 drives the feeder 312 while monitoring the value measured by the weight sensor 314 . when a specified quantity of the additive has been received by the weigh hopper 313 , the feeder 312 is stopped . the weigh hopper is then controlled at the appropriate time to discharge the additive into a supply tube 320 for guiding to a mixing chamber ti located beneath the tube 320 with its gate 324 open . if the flow rate of the additive from the charge hopper 311 or the amount of the additive therein is insufficient and the specified quantity of the additive material fails to be received by the weigh hopper 313 within a specified length of time , the control device 330 concludes that an abnormal condition has occurred and outputs a discharge abnormality signal s 5 to the control unit 700 . upon receiving the discharge abnormality signal s 5 , the control unit 700 outputs signals s 9 and s 10 to the packaging device 400 and the sorting device 500 to eliminate defective products which have not been flavored properly . the structure of the dispenser 310 depends on the form of the additive . if a liquid flavored is involved , an air spray device may be appropriate . if the additive is in the form of a paste , a screw conveyor capable of controlling the supply according to its angle of rotation may be used . if the additive is in a granular or powder form , a device capable of controlling the supply according to the volume may be preferred . although fig2 shows an embodiment whereby an abnormality in the supply rate of the additive is detected by the weight measured by the weigh hopper 313 , neither is this intended to limit the scope of the invention . the method of detecting an abnormal situation varies , depending on the mechanism for supplying the additive . if the additive is a liquid , for example , an abnormal condition may be detected by means of a flow rate sensor . whatever the form of additive , an abnormal supply condition may be detected by means of a weight sensor to monitor the rate of its decrease . when a discharge requesting signal s 6 is outputted from the packaging device 400 , the control device 330 stops drum t m directly above a chute 410 of the packaging device 400 at discharge position 356 with its gate facing down . at the same time , drum t 1 stops at a position directly below the timing hopper 220 with its gate 324 facing up . thereafter , the control device 330 opens the slide gates 324 of these two drums t 1 and t m and outputs a discharge end signal s 7 to the packaging device 400 and a discharge requesting signal s 2 to the weighing device 200 . as the discharge requesting signal s 2 is received , the weighing device 200 opens the timing hopper 220 and transmits a discharge end signal s 8 to the control device 330 . thus , each of the drums t 1 - t m is stopped whenever it comes to the position directly above the packaging device 400 and discharges the flavored food items down to the packaging device 400 . at the same time , an emptied drum receives a new batch of food items from the timing hopper 220 and a specified amount of additive is added from the dispenser ( s ) 310 to adjacent drums . thereafter , the control device 330 rotates the drums t 1 - t m such that the food items m and the additives are stirred together . examples of the packaging device 400 include those adapted to open a bag and fill items in the opened bag and the so - called vertical pillow type adapted to form an elongated film into a tubular shape while filling it with items , to seal simultaneously the top of the filled bag and the bottom of a next bag to be filled and to cut the film in between . with such a vertical pillow type packaging device , bags which are not sealed or cut can be produced temporarily by changing its mode of operation . thus , when the control unit has received an error signal s 3 from the weighing device 200 or a discharge abnormality signal s 5 from the mixing device 300 , a mode changing signal s 9 may be outputted to the packaging device 400 to change the mode of its operation such that properly produced products and defective products can be easily distinguished from the ways they are packaged . the aforementioned sorting device 500 is for the purpose of eliminating defective bags b from the production line described above in response to a signal s 10 from the control unit 700 . if it is disposed on the downstream side of the packaging device 400 , as is the case according to the embodiment being described , it may appropriately comprise a sorting conveyor . if it is disposed between the mixing device 300 and the packaging device 400 , it may comprise a switching chute adapted to change the direction of discharge in response to a command signal . thus , although an error may be committed in the flavoring process , defective products can be dependably prevented from being shipped . the packing device 600 is for packing the completed bags b in cardboard boxes for shipment and also serves to count the number of bags b which have been handled . the counted number is transmitted to the control unit 700 to be used in production management . the control unit 700 is for controlling the devices 200 , 300 , 400 , 500 and 600 in proper coordination and includes an input / output device 710 for communicating with these devices to control them individually and a memory 720 for storing production data on products for each kind , for example , as shown in fig6 . the memory 720 stores data for each kind of product such as the kind of flavoring material to be applied , the rate of its application , the speed of operation of the packaging device ( say , in bpm = bags per minute ), the weight of each bag to be produced and the planned number of bags to be produced . if the user operates on the input / output device 710 to input a product ( code ) number , various data on the corresponding kind of product are retrieved and transmitted to the individual ones of the corresponding devices . for example , the data on the kind and rate of application of the flavoring material are transmitted to the mixing device 300 , the speed of operation is transmitted to the packaging device 400 and the weight of each bag is transmitted to the weighing device 200 . the planned number of products is set in a microcomputer 730 . when the user operates a start key displayed on the input / output device 710 , the control unit 700 starts to control the devices from the upstream side , recording the numbers of processed batches ( or bags ) individually by the devices 200 , 300 , 400 , 500 and 600 . from these data , the microcomputer 730 calculates the number of batches ( or bags ) yet to be processed . if this value becomes zero for any of these devices , a stop command is delivered to the corresponding device to stop its operations . in the case of an error where defective products have been produced and eliminated , the deficiency caused thereby is added to the planned number of products for the devices on the upstream side such that a desired number of finished products will be produced . in this manner , a desired planned number of products can be obtained without producing a waste . since each additive dispenser 310 is adapted to dispense additive to one batch of food times at a time , it need not be as big as the conventional devices . thus , a plurality of additive dispensers each for applying a different kind of additive may be provided as shown in fig3 . it is also possible in another application , to produce one bag at a time of differently seasoned food items in a sequential manner such that a series of differently flavored packages can be produced , as could not be done by the prior art technology . for example , one kind of additive may be added to even - numbered drums and another kind may be added to odd - numbered drums . since none of the these drums is going to be used for different additives , there is no washing problem . the invention has been described above by way of a system with one production line to carry out weighing , flavoring , packaging and packing but a distributing device such as disclosed in japanese patent publication tokko 4 - 35132 may be used if a plurality of such production lines are used on the upstream side of the transporting device 100 for each or the production lines such that food items can be distributed among the production lines uniformly . if each production line is associated with a specified kind of additive in such a system , products of different kinds can be produced simultaneously immediately before they are packaged and items which are left over can be returned and recycled to another production line .
a mixing system includes a portioning device for sequentially supplying batches of a specified quantity of foodstuffs at a supply location . a mixing device includes a number of mixing chambers which can be sequentially aligned with the foodstuff supply location . a dispenser is provided for dispensing measured quantities of an additive at an additive supply location spaced from the foodstuff supply location . the mixing chambers are movable about a closed path so as to be sequentially brought into alignment with the foodstuff supply location and the additive supply location . a control system controls operation of the portion device , mixing device and dispenser . a packaging device is disposed downstream to the supply location and below the mixing device for packaging the batch of foodstuffs in a bag . each mixing chamber is operable above the packaging device to discharge its contents into the packaging device .