Former Head With Rotary Drum

Abstract

There is disclosed a former head ( 1 ) with rotating drums ( 9, 10 ), in which is mounted needle rollers ( 11, 12 ), and which is used in dry forming of fibrous web or tissue ( 4 ). The drums ( 9, 10 ) are composed of at least two semi-cylindrical segments ( 9 A, 9 B; 10 A, 10 B) readily separating in axial direction, and which are mounted on a bearing ring ( 14 ) protruding into the drums ( 9, 10 ). The drum segments are held together on the bearing ring ( 14 ) by means of a segmented clamping ring ( 18 ). By such design, it is possible to perform rapid mounting and dismounting of the drum without need for dismounting the needle rollers ( 11, 12 ).

1 . A former head of the kind that includes at least one rotary drum, which at each end is mounted in a bearing gable in which a needle roller is mounted, and which is used for dry forming of fibrous web, where a fibre material mixed with air may be fed by injection into the rotary drum, characterised in that the drum is composed of at least two partly cylindric, readily separatable segments which are mounted on a bearing ring at each of their ends, the bearing ring projecting from the bearing gable and into the drum, that the drum segments are held together on the bearing ring by a corresponding segmented clamping ring, and that the needle roller is mounted on a bearing bracket in the bearing gable.  
   
   
       2 . Former head according to  claim 1 , characterised in that clamping ring segments, drum segments and bearing rings have means for releasable securing of the clamping ring segments and the drum segments to the bearing rings.  
   
   
       3 . Former head according to  claim 2 , characterised in that the means for releasable securing include a screw passing through holes in the clamping ring segments and the drum segments and which is screwed into the bearing ring.  
   
   
       4 . Former head according to  claim 1 , characterised in that the bearing ring has an outer diameter corresponding to the inner diameter of the drum, that a projecting back is provided on the outer side of the bearing ring, and that the end parts of the drum segments are profiled for forming a groove for accommodating the back of the bearing ring.  
   
   
       5 . Former head according to  claim 4 , characterised in that the clamping ring segments have an internal groove for accommodating the profiled end parts of the drum segments.  
   
   
       6 . Former head according to  claim 1 , characterised in that further clamping rings are disposed at one or more intermediate positions between the ends of the drum, and that such further clamping rings are mutually displaced on possible succeeding drums.  
   
   
       7 . Former head according to  claim 1 , characterised in that the bearing brackets for the needle roller are disposed inside the bearing gables.  
   
   
       8 . Former head according to  claim 8 , characterised in that the bearing brackets of the needle rollers are supporting the needle rollers spaced apart from the ends thereof.  
   
   
       9 . Former head according to  claim 1 , characterised in that the drum segments, which are assembled into forming a drum, have the same or varying perforations.