Centralized control system for open end spinning machines

Claim 1

A centralized control system for open end spinning machine comprising (a) a group control unit comprising (a-1) a first variable frequency power supply connected to a plurality of spinning units (a-2) a first spinning control means composed of a plurality of sequentially operated logical elements connected in series, said first spinning control means producing from the final-stage logical elements a command which is fed to said first power supply so as to increase the operational frequency of said power supply, said first spinning control means further producing from the respective logical elements parallel outputs each of which is fed to said spinning units so as to control the spinning operation thereof, (b) an individual control unit comprising (b-1) a second variable frequency power supply connected to a plurality of spinning units (b-2) a second spinning control means, which operates in response to a detecting signal of yarn breakage occurred in any one of said spinning units, composed of a plurality of sequentially operated logical elements connected in series, said second spinning control means producing from the final-stage logical elements a command which is fed to said second power supply so as to increase the operational frequency of said second power supply, said second spinning control means further producing from the respective logical elements parallel outputs each of which is fed to the spinning unit in which yarn breakage is occurred in order to control the starting state of the spinning operation during which operation the repair of yarn breakage is effected, (b-3) a synchronizing detecting means producing an output when the operational frequency of said second power supply in said individual control unit becomes equal to the operational frequency of said first power supply in said group control unit, (b-4) a switching means for changing the control of the spinning unit in which the repair of yarn breakage has been effected from said individual control unit to said group control unit in response to the output of said synchronizing detector, and (c) said plurality of spinning units each of which comprises (c-1) a spinning mechanism for rendering sliver of fibers spun to form a spun yarn and taking up the spun yarn onto a take-up means, (c-2) said spinning mechanism including a yarn breakage sensor provided in the stream of spun yarn, (c-3) a driving means for driving said spinning mechanism including a plurality of driving motors controlled by the output from said first or second variable frequency power supply, wherein when there is no yarn breakage in any one of the spinning units of the plurality, the spinning units are all controlled by said group control unit, while when there occurs yarn breakage detected by said yarn breakage sensor in any one of the spinning units of the plurality, only the spinning unit in which yarn breakage is occured is shifted from the control of said group control unit to the control of said individual control unit while the remaining spinning units in which no yarn breakage is occured remain under the control of said group control unit, and then after yarn breakage occured in the spinning unit is repaired under the control of said individual control unit, the spinning unit in which the repair of yarn breakage is effected is for a second time shifted to the control of said group control unit.