Patent ID: 7566837

Claim:
A combination weigher comprising: N groups of combination hoppers which are N hopper lines of arcuate sections composing a line of combination hoppers including a plurality of circularly arranged combination hoppers for receiving objects to be weighed; wherein N is a plural number; N collecting chutes disposed below the groups of combination hoppers to respectively correspond to the groups of combination hoppers for collecting the objects to be weighed discharged from the combination hoppers of the corresponding groups of combination hoppers and discharging the same from an outlet provided in a lower portion thereof; N collecting hoppers provided at the outlets of the collecting chutes to respectively correspond to the groups of combination hoppers and the collecting chutes, for temporarily retaining the objects to be weighed discharged from the outlets of the collecting chutes, and the collecting hoppers arranged to then discharge the objects to be weighed into a single inlet of a packaging machine; and a control means for repeatedly carrying out, with respect to the groups of combination hoppers and the corresponding collecting hoppers, a series of processes including a combination process for performing a combination calculation on a basis of the weight of the objects to be weighed fed into each combination hopper of the groups of combination hoppers and determining a single combination of the combination hoppers which causes the total weight of the fed objects to be weighed falls within a predetermined weight range, a discharge preparation process for discharging the objects to be weighed from the combination hoppers forming the combination determined by the combination process, and a discharge process for discharging from the collecting hoppers the objects to be weighed, discharged from the combination hoppers and retained in the collecting hoppers, the control means carrying out the combination process and the discharge preparation process with respect to each of the groups of combination hoppers sequentially with a time difference 1/N of one operation cycle time, and carrying out the discharge process with respect to each of the collecting hoppers sequentially with a time difference of 1/N of the one operation cycle time, the one operation cycle time being the time taken from the start of discharging of the objects to be weighed from the combination hoppers forming the combination determined by the combination process, followed by feeding of the objects to be weighed into the combination hoppers forming the combination and subsequently performing a combination calculation in a next combination process at least by using the weight of the objects to be weighed in the combination hoppers forming the combination, until immediately before the start of discharging of the objects to be weighed from the combination hoppers forming the combination determined in the next combination process.