Unit and a method for feeding tobacco in a machine for manufacturing tobacco products

Abstract

In a cigarette maker, shredded tobacco passes through a feed and transport section toward a unit by which divided particles of the tobacco are gathered into at least one stream providing the filler for cigarettes. By positioning one or more sensors either along the feed and transport section or at a point upstream, relative to the feed direction of the tobacco, it becomes possible to identify the type of tobacco being handled at any given moment, so that when production schedules include a changeover from one brand to another, supervisors can be certain that the right type of tobacco has been selected, and ensure that different types of tobacco will not mingle.

1 . A tobacco feed unit in a machine for manufacturing tobacco products, comprising: 
 means by which shredded tobacco is fed along a predetermined path toward a unit of the machine by which tobacco particles are formed into at least one stream;    sensing means deployed along the predetermined path, by which the tobacco is identified according to type before it reaches the forming unit.    
   
   
       2 . A unit as in  claim 1 , wherein tobacco is supplied from at least one inlet duct to a tobacco feed and transport section comprising: 
 at least one header chamber into which the inlet duct discharges and in which the shredded tobacco collects;    a carding unit fed with tobacco from the header chamber;    a descending duct into which tobacco is directed from the carding unit;    an ascending duct of which the top end connects with the unit forming the stream of tobacco;    a transport device by which the tobacco is conveyed from a bottom end of the descending duct toward a bottom end of the ascending duct.    
   
   
       3 . A unit as in  claim 2 , wherein sensing means comprise at least one sensor placed upstream of the carding unit, relative to the flow of tobacco.  
   
   
       4 . A unit as in  claim 3 , wherein the sensor is placed in the header chamber.  
   
   
       5 . A unit as in  claim 3 , wherein the sensor is placed in the inlet duct or upstream of the selfsame duct.  
   
   
       6 . A unit as in  claim 2 , wherein sensing means comprise at least one sensor placed downstream of the carding unit, relative to the flow of tobacco.  
   
   
       7 . A unit as in  claim 6 , wherein the sensor is placed in the descending duct.  
   
   
       8 . A unit as in  claim 6 , wherein the sensor is mounted along the transport device.  
   
   
       9 . A unit as in  claim 6 , wherein the sensor is placed in the ascending duct.  
   
   
       10 . A unit as in  claim 3 , wherein the sensors are olfactory sensors.  
   
   
       11 . A unit as in  claim 3 , wherein the sensors are infrared sensors.  
   
   
       12 . A unit as in  claim 3 , wherein sensing means further comprise a central processing unit by which input signals from the sensors are received and compared with stored parameters related to different types of tobacco, in such a way as to generate an output signal identifying the type of tobacco advancing currently along the predetermined path.  
   
   
       13 . A machine for manufacturing tobacco products, comprising at least one garniture assembly forming a continuous tobacco rod, a tobacco feed and transport section as in  claim 2 , equipped with sensing means.  
   
   
       14 . A method of feeding tobacco in a machine for manufacturing tobacco products as in  claim 13 , including the steps of: 
 shutting down the machine to suspend production of a first brand of tobacco product made from a first type of tobacco;    replacing the first type of tobacco with a second type of tobacco from which to manufacture a second brand of tobacco product;    activating sensing means in order to identify the type of tobacco being handled by the machine before initiating production of the second brand of tobacco product.    
   
   
       15 . A method as in  claim 14 , including the further steps of closing off the header chamber to prevent the second type of tobacco from flowing into the carding unit, feeding a predetermined quantity of the second type of tobacco into the header chamber by way of the inlet duct, and activating sensing means deployed upstream of the carding unit for an interval of time sufficient to identify the type of the new tobacco.  
   
   
       16 . A method as in  claim 14 , including the step of emptying the machine of the first type of tobacco, wherein the step of activating the sensing means consists in activating at least one sensor placed downstream of the carding unit for an interval of time sufficient to verify that there is no trace of the first type of tobacco in the machine before initiating production of the second brand of tobacco product.