device for controlling zigarettenmaschinen

摘要

1,173,120. Cigarette-making machines. BRITISH-AMERICAN TOBACCO CO. Ltd. 3 Sept., 1968, No. 41781/68. Heading A2C. In a means for exercising control, in a cigarette-making machine, in dependance upon short-term variations of air pressure detected by a pressure-responsive device at a point in the machine at which longer-term variation of pressure also occurs, wherein the detected varying pres-. sure is applied directly to one side of an air pressure unit and a compensating pressure applied to the other side, the effect of longer-term variation is compensated for by deriving the compensating pressure via a low-pass filter circuit from the same detected varying pressure. An air cell (not shown) is connected directly by a tube 6 to one side of a pneumatic capsule 2 and indirectly, via branch 14 leading to an integrating low-pass filter circuit comprising a capillary 13 and a reservoir 12, to the other side of the capsule 2. Dimensions of its components are given for a filter circuit having a time constant of 8 to 10 seconds and suitable for controlling the level of a tobacco-trimming knife of a cigarette-making machine in response to the resistance to air flow through the bed of tobacco on an air pervious collecting band of the machine as detected by an air cell.