Patent GB-795533-A (GB)
Title: A device for segregating selected cigarettes
IPC: A24C5/34
Filed: 1955-02-25
Abstract: 795,533. Sorting solid materials. MOLINS, D. W., POWELL, G. F. W., and MOLINS MACHINE CO., Ltd. Feb. 22, 1956 [Feb. 25, 1955], No. 5684/55. Class 117 [Also in Groups VI, XXXVI and XL(b)] Cigarettes C are moved on a drum 5, Fig. 1, or 121, Fig. 7, laterally past a device 11 or 127 which detects without mechanical interaction cigarettes of abnormal mass or mass distribution and activates by electrical means, suction means 16 or 152 to remove such cigarettes whilst cigarettes of normal mass or mass distribution pass on for delivery to a conveyer 25 or 155. Dielectric detector. In Fig. 1, cigarettes C on the delivery belt 1 of a continuous-rod cigarette-making machine are passed by a cam-operated pusher 2 over a horizontal or downwardly inclined plate 3 to flutes 4 of the drum 5. All the cigarettes may pass to one drum 5, or the drum-andpusher arrangement may be duplicated side-by-side, alternate cigarettes passing to each drum. The flutes 4 are formed in members 9 co-acting in turn with a stationary member 11 to form a pair of condenser plates with a cigarette as a dielectric the strength of which varies with cigarette mass providing cigarette moisture content is held constant. When opposite the member 11, each member 9 touches a fixed contact 37 and the condenser 9, 11 is placed in a circuit comprising a 130 megacycle/second oscillator 100, Fig. 6, a 10 (to 15) kilocycle/second modulator 101 and a detector 102 which feeds only the 10 kilocycle/second component as a signal to a difference unit 103 also fed directly from the modulator 101 with a phase-corrected 10 kilocycle/second-signal, the signals balancing out for cigarettes of correct weight. For underweight of overweight cigarettes a residual signal passes to an amplifier-rectifier 105 and, via a switch device 106 which allows passage only when a cigarette is correctly positioned for detection, to a high-speed relay 107 to close contacts 108 and energize a solenoid 12 to magnetically draw out an appropriate plunger valve 14, Fig. 1, in the member 16 and connect a suction line 20 with an appropriately positioned suction arm 18 of the member 16 to pick up the selected cigarette and transfer it to a conveyer band 23, the suction being appropriately cut off by return of the valve 14 by a hammer lever 26 actuated by a spring 30 under the control of a cam 28. To detect abnormal mass distribution there may be a pair of condenser plates as above for each cigarette end. Beta-ray detector. In Fig. 7, cigarettes C supplied as before are accurately positioned in slots 122 in the drum 121 by a resilientlytipped pusher 123 and a guide 125 before passing between a beta-ray source 126 and an ionization chamber 127 filled with argon or carbon dioxide. Current due to ionization flows in a resistor 128 and causes a voltage to be applied to the input terminal 129 of an amplifier 130 a large fraction of the output voltage of which is taken off a potential divider 132 and applied as degenerative feedback to the resistance 128, giving a rapid response which allows the amplifier output pulse height to be inversely proportional to individual cigarette weight. When the pulse height exceeds a reference voltage selected by a potential divider 133 a high-speed relay operates to energize a solenoid 136 and withdraw its plunger from a stop 143 on a spring-loaded plunger which under the control of a cam 141 ejects the corresponding underweight cigarette to a suction device 152 delivering to a conveyer 153, cigarettes not so ejected being blown on to the conveyer 155 by a nozzle 154. The solenoid has a magneticallyoperated "hold-on" switch 147, its circuit only being broken when a pin 149 on the cam 141 opens a switch 150. To detect abnormal mass distribution there may be a detecting mechanism as above for each cigarette end.