| 摘要 |
Apparatus for forming a cylindrical element from a fibrous web, the element having a predetermined density characteristic radially thereof, comprises an endless belt, guide means about which said belt is entrained and which are arranged to define a loop in said belt to which loop the fibrous web is fed, said guide means being arranged so that, in use, said loop extends around substantially the entire circumference of the element forming in said loop, means for driving said belt so as to thereby cause the fibrous web to be fed into said loop and there to roll up on itself, and means for progressively increasing the diameter of said loop, said loop diameter increasing means including a control member about which said belt is entrained and which is movable to vary the dimensions of said loop, and means for moving said control member so as to increase the diameter of said loop at a rate which is a function of the linear speed of the belt and the length and weight per unit length of the fibrous web so as to obtain the predetermined radial density characteristic of the cylindrical element to be formed in said loop.
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