Apparatus for convoluting adhesive-coated uniting bands around

Abstract

A filter cigarette making machine wherein two plain cigarettes of unit length are connected to a coaxial filter plug of double unit length therebetween by an adhesive-coated uniting band which is convoluted around the filter plug and the inner ends of the plain cigarettes. The machine has a rotary drum-shaped draping conveyor and a heated stationary block-shaped rolling device adjacent to the peripheral surface of the conveyor to normally define therewith a gap of a width slightly less than the diameter of a group consisting of two coaxial plain cigarettes and a filter plug therebetween. Successive groups, each of which carries a non-convoluted uniting band, are fed into the gap by moving sideways whereby the groups roll about their own axes and the uniting bands are converted into tubular envelopes. A parallel motion automatically retracts the rolling device from the draping conveyor when the prime mover of the machine is arrested whereby the groups between the conveyor and the rolling device are free to leave the machine by gravity. This insures that filter plugs which are sensitive to heat cannot adhere to or contaminate the peripheral surface of the draping conveyor and/or the adjacent surface of the rolling device. The parallel motion is actuated by a double-acting pneumatic cylinder and piston unit which receives pressurized fluid by way of a valve whose solenoid is controlled by a tachometer generator which monitors the speed of the draping conveyor.