Opening machine and an opening method

Abstract

An opening machine for separating the fibres from intermingled impurities in cotton tufts comprises a storage bin into which cotton tufts to be processed are introduced, and an opening cylinder associated with cleaning blades for separating the impurities from the fibres and with suction openings for removing the impurities and the fibres separately. The opening machine comprises a pre-opening roller for performing a preliminary opening of the tufts. The cotton material is withdrawn from the bin by feed rollers, is processed by the pre-opening roller, and is introduced into a chamber in the form of pre-opened tufts. A final feed roller withdraws the tufts from the chamber and supplies them to the opening cylinder. The final feed roller works at a withdrawal rate greater than that of the feed rollers to prevent accumulation of the tufts in the chamber.

What is claimed is:  
     
         1 . An opening machine for separating the fibres from intermingled impurities in cotton tufts, of the type comprising: 
 a storage bin into which cotton tufts to be processed are introduced,    an opening cylinder associated with means for separating the impurities from the fibres and with means for removing the impurities and the fibres, separately, from the opening machine,    the machine further comprising roller pre-opening means which are interposed between the storage bin and the opening cylinder and which can cooperate with one another to perform a preliminary opening operation on the tufts and to supply the tufts to the opening cylinder, in controlled manner, in an at least partially-opened and non-compacted condition.    
     
     
         2 . The opening machine of  claim 1 , wherein the roller pre-opening means comprise a pre-opening roller which can be rotated at controlled speed and which has projecting peripheral elements suitable for exerting an at least partial opening action on the tufts.  
     
     
         3 . The opening machine of  claim 2 , wherein the peripheral elements are inclined slightly in the direction of rotation of the pre-opening roller.  
     
     
         4 . The opening machine of  claim 2 , wherein the roller pre-opening means further comprise at least one second roller which is operatively associated with the pre-opening roller and which can be rotated at a controlled tangential velocity, in the same direction of rotation as the pre-opening roller, in order to exert the at least partial opening action on the tufts.  
     
     
         5 . The opening machine of  claim 4 , wherein the second roller has a clothing suitable for temporarily restraining the tufts thereon to permit at least partial opening of the tufts by means of the peripheral elements of the pre-opening roller.  
     
     
         6 . The opening machine of  claim 4 , wherein the second roller is located upstream of the pre-opening roller.  
     
     
         7 . The opening machine of  claim 4 , wherein the pre-opening means further comprise a third feed roller, located upstream of the pre-opening roller and beside the second roller, in order to cooperate with the second roller in the supply of the tufts from the storage bin to the pre-opening roller.  
     
     
         8 . The opening machine of  claim 4 , wherein the pre-opening roller is rotated at a tangential velocity greater than that of the second roller.  
     
     
         9 . The opening machine of  claim 1 , wherein it comprises a supply chamber located in an intermediate position between the roller pre-opening means and a final feed roller associated with the opening cylinder, the supply chamber being suitable for allowing the material to pass through in a non-compacted and partially-opened condition.  
     
     
         10 . The opening machine of  claim 9 , wherein: 
 the final feed roller which supplies the material withdrawn from the intermediate supply chamber to the opening cylinder, and    the rollers of the roller pre-opening means which withdraw the material from the storage bin,    have dimensions such, and/or are driven in a manner such, as to prevent accumulation of material inside the intermediate chamber.    
     
     
         11 . The opening machine of  claim 10 , wherein the final feed roller is arranged to supply the material from the intermediate chamber to the opening cylinder with a delivery rate no less than the amount of material withdrawn from the storage bin by the roller pre-opening means per unit of time.  
     
     
         12 . The opening machine of  claim 11 , wherein the final feed roller is arranged to supply the material from the intermediate chamber to the opening cylinder with a theoretical delivery rate about 20-50 times greater than the delivery rate of the roller pre-opening means, or the quantity of material withdrawn from the storage bin thereby per unit of time.  
     
     
         13 . The opening machine of  claim 9 , wherein the intermediate chamber comprises vent means for eliminating excessive air pressure.  
     
     
         14 . The opening machine of  claim 15 , wherein the vent means comprise a perforated plate or grating defining one of the walls of the intermediate chamber.  
     
     
         15 . The method of opening cotton tufts and the like by means of an opening machine according to  claim 1 , the method including the steps of: 
 a) introducing cotton tufts to be processed into a storage bin,    b) withdrawing the cotton material from a lower region of the bin by means of roller feed means,    c) pre-opening the cotton material withdrawn by the roller feed means, by means of a pre-opening roller rotated at controlled speed and having projecting peripheral elements suitable for exerting an at least partial opening action on the tufts,    d) introducing the tufts into an intermediate chamber in an at least partially-opened condition,    e) withdrawing the tufts from the intermediate chamber by means of a final feed roller operatively associated with an opening cylinder,    f) opening the tufts by means of the opening cylinder, separating the impurities from the fibres, and removing the impurities and the fibres, separately, from the opening machine.    
     
     
         16 . The method of  claim 15 , wherein the step e) of the withdrawal of the tufts from the intermediate chamber is achieved by adjustment of the speed of the roller feed means and of the speed of the final feed roller in a manner such as to prevent accumulation of the cotton material in the intermediate chamber.  
     
     
         17 . The method of  claim 16 , wherein the final feed roller is rotated in a manner such as to supply the material from the intermediate chamber to the opening cylinder with a theoretical delivery rate about 10-50 times greater than the delivery rate of the roller pre-opening means, or the quantity of material withdrawn from the storage bin thereby per unit of time.