Abstract:
An apparatus for producing a fiber lap includes a generally vertically oriented feed chute in which fiber tufts are introduced at the top and from which a fiber lap is discharged at the bottom. There is provided a movable wall element for varying an effective width of the feed chute for altering the width of the fiber lap produced by the apparatus.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to an apparatus which is connected to a rollercard unit or carding machine upstream thereof for producing a fiber lap. The apparatus includes a feed chute into which fiber tufts are introduced at the top and are withdrawn as a fiber lap from the bottom. During this operation, an air stream enters the feed chute which exits therefrom through air exit openings provided in walls of the feed chute. 
     In practice, it is often a desideratum to obtain a fiber lap of different widths. If, for example, a changeover in the product occurs, it may be required to vary the lap width. According to known methods, the lap is brought to the desired width by cutting, blowing or suction, wherein the excessive material removed from the lap sides is reintroduced into the feed chute and is caused to participate again in the lap formation. It is a disadvantage of such an arrangement that it requires a certain additional technological input and further that the reintroduced lap edge portions pass more than once through lap formation and therefore may cause undesirable changes in the lap structure. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an improved apparatus of the above-outlined type by means of which a fiber lap can be produced with easily variable width without removing material from the lap sides. 
     This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the feed chute has at least one laterally displaceable wall element for varying the width of the fiber lap discharge opening of the feed chute, whereby the width of the delivered fiber tuft lap is varied. 
     By means of the arrangement according to the invention, it is feasible to produce fiber laps of different widths without the need of removing excessive marginal portions of the fiber lap. The laterally displaceable wall element is arranged immediately at the marginal zone of the lap and thus determines the width thereof. 
     According to a further feature of the invention, in a lap forming apparatus having an upper reserve chute and a lower feed chute, the lap width is expediently set in the lower feed chute. For this purpose, in the zone of the lateral feed chute wall, an obliquely downwardly oriented, angularly settable plate is provided which extends from the side wall to the air exit openings and the delivery rollers arranged at the discharge opening of the feed chute. The plate sealingly adjoins the lateral wall of the feed chute. The plate may have a U-shaped configuration whereby a sealing effect with respect to the front and rear walls of the lower feed chute is also achieved. By displacing the plate which practically in each position forms the hypotenuse of a triangle whose short sides are formed by the side wall and the delivery rollers, the position of the lap edge, that is, the lap width, may be varied in a stepless manner. Thus, the width and the position of the lap can be infinitely varied within the setting limits of the displaceable wall element. 
     In case the lap forming apparatus delivers divided laps, according to the invention several laps of variable width may be obtained. For such a case, the lap divider is provided with the obliquely oriented plates or the lap divider is itself so structured that the separating walls can be pivoted and displaced obliquely. The plates may be set and immobilized from the outside of the lower feed chute in case a constant lap width is required for a certain production period. For producing laps of predetermined shape, the wall elements can be displaced during operation. By coordinating the delivery roller speed with the motion of the wall elements, a desired number of different lap shapes may be obtained. This may lead to a reduction of waste during a subsequent lap cutting operation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a schematic front elevational view of a preferred embodiment of the invention. 
     FIG. 2 is a schematic sectional elevational view of another preferred embodiment of the invention. 
     FIG. 3 is a schematic front elevational view of another preferred embodiment of the invention. 
     FIG. 4 is a schematic perspective view of still another preferred embodiment of the invention. 
     FIG. 5 is a schematic front elevational view of a further preferred embodiment of the invention. 
     FIG. 6 is a schematic front elevational view of still another preferred embodiment of the invention. 
     FIG. 7 is a schematic top plan view of one part of a further preferred embodiment of the invention and a fiber lap produced thereby. 
     FIG. 8 is a schematic front elevational view of a further preferred embodiment of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning to FIG. 1, there is shown a feed chute 1 which, at its upper inlet opening for the fiber tufts is in communication with a pneumatic conveyor duct 2 and which, at its lower output end is provided with two delivery rollers 3, 4. In at least one chute wall, preferably in the lower zone of the front or rear wall, up to a certain height air outlet openings 5 are provided which may be constituted by a comb-like structure known by itself and disclosed, for example, in German Auslegeschrift (Application Published after Examination) No. 1,286,436. 
     In the feed chute 1 there is arranged a wall element 6, for example, a sheet metal plate whose width extends from the front wall to the rear wall of the chute 1. The upper end 6&#39; of the plate 6 is associated with a lateral wall 1a of the feed chute 1 while the lower end 6&#34; of the plate 6 is associated with the lower end of the chute 1, immediately above the delivery rollers 3 and 4. At its lower end 6&#34; the wall element 6 is at a distance from the lateral wall 1a and thus the wall element 6 extends obliquely downwardly towards the oppositely located chute side wall 1b from which the lower end 6&#34; is spaced as well. The wall element 6 may be displaced from a relatively steep position (shown in solid lines in FIG. 1) to a less steep position (shown in broken lines in FIG. 1) so that the fiber lap 9 discharged by the feed chute 1 may be varied in width. The upper zone of the wall element 6 reaches into the upper zone of the feed chute 1. The fiber tufts 7 fly as individual tufts downwardly through the major part of the feed chute 1. The width of their path is gradually reduced by the wall element 6 to prevent the tufts 7 from a premature bunching. There occurs only in the lower part of the feed chute 1 a fiber tuft accumulation (filling) 8 of the superimposed fiber tufts which are, from above, pneumatically densified by an air stream. The tuft filling 8 covers the air outlet openings 5. The air stream exits from the feed chute 1 through the air outlet openings 5. The densified fiber tuft filling 8 is withdrawn as a fiber lap 9 from the lower end of the feed chute 1 by means of the delivery rollers 3 and 4. 
     Turning now to FIG. 2, between the conveyor duct 2 and the lower feed chute 1 there is arranged an upper chute 10, from which the fibers are advanced into the feed chute 1 by means of a feed roller 11 and an opening roller 12. At the upper end of the feed chute 1 a fan 13 is arranged which directs an air stream into the feed chute 1. In the front wall 1c and the rear wall 1d of the feed chute 1 respective air outlet openings 5a and 5b are provided. The wall element 6 has upper and lower edges 6&#39; and 6&#34; which extend from the front wall 1c to the rear wall 1d. Underneath the delivery rollers 3 and 4 there is arranged a guide tray 14 for the lap 9. 
     Turning to FIG. 3, the wall element 6a is, at its upper edges, articulated at 14 to a vertical support plate 15 which is vertically displaceably connected with the stationary lateral wall 1a of the feed chute with the intermediary of a mounting element 16. 
     According to FIG. 4, lateral edges of the wall element 6b are bent angularly at 6b&#39; so that the wall element has an approximately U-shaped cross section. The lower terminal portion 6b&#34; of the wall element 6b which is situated in the zone of the air outlet openings 5a, 5b of the feed chute 1 is oriented parallel to the lateral walls 1a and 1b of the feed chute 1. The wall element 6b may be, in case of a sufficient own weight, supported at its upper zone (edge 6b&#34;&#39;) at the wall 1b. The lower part 6b&#34; may be supported (by means not shown) at its side on the chute wall where the air outlet openings 5a, 5b are provided. 
     FIG. 5 illustrates a vertical fiber tuft divider 17 which is arranged in the feed chute for dividing it into two partial chutes. The upper, rounded part of the divider 17 may reach approximately to the mid height of the feed chute 1, while the lower zone of the divider 17 extends into the divided fiber tuft columns 8a, 8b which leave the fiber chute 1 as respective divided laps 9a, 9b. The lateral walls 1a and 1b of the feed chute 1 are each associated with a wall element 6c and 6d, respectively, whose upper respective ends 18 and 19 extend into respective support devices 20 and 21 through non-illustrated slots provided in the lateral walls 1a and 1b. The support devices 20 and 21 are situated at the outside of the lateral walls 1a and 1b. The upper ends 18 and 19 of the respective wall elements 6c and 6d are vertically displaceably arranged in the support elements 20 and 21 so that a varying slope of the wall elements 6c and 6d and thus a varying width and degree of fiber tuft filling 8a and 8b of the lap 9a and 9b may be set. The oblique positioning of the wall elements may be effected in a continuous (stepless) manner. 
     Turning now to FIG. 6, a displaceable wall element 6e is associated with the tuft divider 17. The upper end of the wall element 6e is vertically displaceably carried in a support element 22 mounted on the divider 17. 
     FIG. 7 illustrates a feed chute 1 in which two wall elements 6f and 6g are arranged which are each connected with an externally located eccentric setting device 24, 25 by means of respective coupling elements 22, 23. Dependent upon the setting of the wall elements 6f, 6g, the width of the lap 9 discharged by the feed chute 1 is varied. In this manner, a fiber lap of predetermined varying contour may be obtained. 
     Turning to FIG. 8, the wall element 6h is formed of three parts which are displaceable telescopically in their longitudinal direction, so that in this manner the entire length of the wall element 6h may be varied. The uppermost part of the wall element 6h is mounted by means of a rotary articulation 26 to the lateral wall 1b of the feed chute 1. By rotating the articulation 26 and varying the length of the wall element 6h the width of the feed chute 1 is varied. 
     It will be understood that the above description of the present invention is susceptible to various changes, modifications and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.