Buffer device for matching the output speed of a lap of a spreading-lapping machine to the input speed of a device for processing the lap downstream of the spreading-lapping machine.

Abstract

Crosslapper, in particular arranged at the outlet from a carding device producing a web of fibers, in particular nonwoven fibers, comprising a front belt carrying the web of fibers in the crosslapper to an infeed or accumulator carriage, a rear belt carrying the accumulated web to a layering carriage and an apron on an upper strand (2′; 2″; 2′″) of which the layering carriage deposits the web accumulated by the accumulator carriage alternately on the bias in one direction and in the other direction to form a lap (N) moving at a speed V1(t) that varies as a function of time, in particular in a periodic manner, the crosslapper also comprising an output belt strand (20′; 20″; 20″′) on which the lap (N) leaves the crosslapper at a speed V2(t) that is different from the speed V1(t), in particular at a constant speed, the lap (N) undergoing at least one turn between the upper strand (2′; 2″; 2′″) and the output belt strand (20′; 20″; 20′″), in particular through 180°, around a roller (3.2′; 4.1″; 3.7′″) mounted such that it can move in translation along the output belt strand (20′; 20″; 20′″), the lap (N) being sandwiched between another strand, turned in the opposite direction to the upper strand (2′), of the apron and the output belt strand (20′) and/or between another strand, turned in the opposite direction to the upper strand (2″; 2′″), of the apron and an upper strand of an intermediate apron (30″; 30′″) and/or between a lower strand of an intermediate apron (30″; 30′″) and the output belt strand (20″; 20′″).

1 . A crosslapper in particular arranged at the outlet of a carding device producing a web of fibers, in particular nonwoven fibers, comprising a front belt carrying the web of fibers in the crosslapper to an infeed or accumulator carriage, a rear belt carrying the accumulated web to a layering carriage and an apron on an upper strand ( 2 ′;  2 ″;  2 ′″) of which the layering carriage deposits the web accumulated by the accumulator carriage alternately on the bias in one direction and in the other direction to form a lap (N) moving at a speed V1(t) that varies as a function of time, in particular in a periodic manner, the crosslapper also comprising an output belt strand ( 20 ′;  20 ″;  20 ′″) on which the lap (N) leaves the crosslapper at a speed V2(t) that is different from the speed V1(t), in particular at a constant speed, the lap (N) undergoing at least one turn between the upper strand ( 2 ′;  2 ″;  2 ′″) and the output belt strand ( 20 ′;  20 ″;  20 ′″), in particular through 180°, around a roller ( 3 . 2 ′;  4 . 1 ″;  3 . 7 ′″) mounted such that it can move in translation along the output belt strand ( 20 ′;  20 ″;  20 ′″), the lap (N) being sandwiched between another strand, turned in the opposite direction to the upper strand ( 2 ′), of the apron and the output belt strand ( 20 ′) and/or between another strand, turned in the opposite direction to the upper strand ( 2 ″;  2 ′″), of the apron and an upper strand of an intermediate apron ( 30 ″;  30 ′″) and/or between a lower strand of an intermediate apron ( 30 ″;  30 ′″) and the output belt strand ( 20 ″;  20 ′″). 
     
     
         2 . The crosslapper according to  claim 1 , characterized in that the roller ( 3 . 2 ′,  4 . 1 ″,  3 . 7 ′″) is mounted such that it can move in translation in a direction parallel to the upper strand ( 2 ′;  2 ″;  2 ′″), in particular the horizontal direction. 
     
     
         3 . The crosslapper according to  claim 1 , characterized in that said other strand, turned in the opposite direction to the upper strand ( 2 ′), extends between two rollers ( 3 . 2 ′,  3 . 3 ′), which are mounted such that they can move in a translationally fixed manner, in particular in a back-and-forth movement. 
     
     
         4 . The crosslapper according to  claim 1 , characterized in that the upper strand of the intermediate belt ( 30 ″;  30 ′″) extends between two rollers ( 4 . 1 ″,  4 . 2 ″;  3 . 7 ′″,  3 . 8 ′″) which are mounted such that they can move in a translationally fixed manner, in particular in a back-and-forth movement. 
     
     
         5 . The crosslapper according to  claim 1 , characterized in that the lower strand of the intermediate belt ( 30 ″;  30 ′″) extends between two rollers ( 4 . 1 ″,  4 . 2 ″;  3 . 7 ′″,  3 . 8 ′″) which are mounted such that they can move in a translationally fixed manner, in particular in a back-and-forth movement. 
     
     
         6 . The crosslapper according to  claim 5 , characterized in that the intermediate belt ( 30 ″;  30 ′″) is an endless belt that can be moved in translation in a back-and-forth movement which extends around the two rollers ( 4 . 1 ″,  4 . 2 ″;  3 . 7 ′″,  3 . 8 ′″) that are mounted such that they can be moved in a translationally fixed manner. 
     
     
         7 . The crosslapper according to  claim 1 , characterized in that the output belt is air-permeable and the apron is an air-impermeable belt, in particular an endless belt. 
     
     
         8 . The crosslapper according to  claim 1 , in which the intermediate belt ( 30 ″;  30 ′″) is provided, and characterized in that the intermediate belt ( 30 ″;  30 ′″) is air-permeable. 
     
     
         9 . The crosslapper according to  claim 1 , characterized in that the upper strand ( 2 ′″) of the apron and the output belt strand ( 20 ′″) form part of the same endless belt and the arrangement is such that the lap (N) is sandwiched before the turn, during the turn and after the turn between the endless intermediate belt ( 30 ′″) and said same endless belt. 
     
     
         10 . An installation comprising a crosslapper according to  claim 1  and a further processing device arranged directly downstream of the crosslapper ( 1 ), and having an input belt moving at the speed V2(t)