US 4,574,816 A · Method and apparatus for forming a filler of fibrous material

Abstract

A continuous rod-like filler which is ready for draping into a web of cigarette paper is obtained by removing the surplus of tobacco from a continuous tobacco stream which is formed at one side of a foraminous belt conveyor the other side of which is adjacent to a suction chamber serving to attract the particles of tobacco to the conveyor. The surplus is removed downstream of the zone where the particles of tobacco are delivered to the conveyor. The density of the filler is monitored subsequent to draping, and the signals which are generated by the density monitoring device are used to vary the pressure in the suction chamber, to vary the speed of a first rotary conveyor which propels particles of tobacco against the belt conveyor and/or to vary the rate of feed of tobacco particles to the belt conveyor by adjusting the speed of a second rotary conveyor which draws tobacco particles from the lower end of a duct. Each of the above adjustments is effective to change the density of the filler so that the changed density matches or more closely approximates an optimum value. The plane in which the surplus is removed from the tobacco stream is maintained at a constant distance from the belt conveyor.

Claims31

Dependent claims

A method of forming a filler of fibrous material, such as tobacco, comprising the steps of continuously feeding fibrous material at a variable rate and with a surplus above that which is required in the filler into a first portion of an elongated path to build up a stream and moving the thus obtained stream in a predetermined direction along said path whereby the surplus extends beyond a fixed plane;

removing the surplus which extends beyond said plane in a second portion of said path downstream of said first portion, as considered in said direction, to thus convert the stream into a filler;
monitoring the density of the filler;
and varying the rate of feed of fibrous material into the first portion of said path, including increasing the rate of feed when the monitored density of the filler decreases and reducing the rate of feed when the monitored density of the filler increases.

Apparatus for forming a filler of fibrous material, such as tabacco, comprising a conveyor defining an elongated path and arranged to transport fibrous material along said path in a predetermined direction;

a source of fibrous material;
adjustable means for feeding fibrous material at a variable rate from said source into a first portion of said path with a surplus above that which is required in the filler whereby the fibrous material forms in said first portion a growing stream and the conveyor transports the stream in said direction with the surplus extending beyond a predetermined fixed plane;
equalizing means for removing from the stream the surplus which extends beyond said fixed plane in a second portion of said path downstream of said first portion to thus convert the stream into a filler;
means for monitoring the density of successive increments of the filler and for generating signals whose characteristics are indicative of the monitored density of the respective increments;
and means for adjusting said feeding means in response to said signals so as to increase the rate of feed when the monitored density of the filler is on the decrease and to reduce the rate of feed when the monitored density of the filler is on the increase.

2 more elements

Dependencies are inferred from the claim text.

Method and apparatus for forming a filler of fibrous material

Life of this patent

Method and apparatus for forming a filler of fibrous material

Life of this patent

Abstract

Claims31