Slideway for Travelling Flats in a Carding Machine

This application claims the priority of German Application No 41 08 921.9 filed Mar. 19, 1991.

The invention relates to a slideway for guiding clothed travelling flats in a carding machine. The travelling flats are advanced by means of at least one endless drive element such as a flexible belt. Opposite ends of each flat bar glide in a slideway along the work path of the flats, and after having reached the end of the work path, the flat bars ar carried back to the beginning of the work path by the endless driving element on the side opposite the slideways. The slideways have a central zone (hereafter also termed as "convex" zone) closely following the curvature of the main carding cylinder at the top portion thereof and two end zones (hereafter also termed as "concave" zones) which closely follow the curvature of the end sprockets of the travelling flats.

Conventionally, the slideway in which the flat bar ends slide is a one-piece plastic component which at one end is immobilized by a securing device at a location where the flat bars enter the slideway. At the end of the concave slideway portion a holding element is secured which clamps, with a clamping element, an end of the slideway by means of a screw-and-nut connection. The flat bars exert a pulling force on the slideway, whereby the concave slideway zones are likely to exert an excessive radial looping pressure on the flats which may lead to a wear of the slideway, to scores or the like. Further, loads as well as high temperatures or temperature variations may cause a plastic deformation of the slideway material which may lead to a faulty guidance of the flat bars in the concave inlet slideway zone.

It is an object of the invention to provide an improved slideway support from which the above-discussed disadvantages are eliminated and which, in particular, ensures a low wear of the slideway and a disturbance-free flat bar guidance during operation.

This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, each slideway is secured at a location to a lateral support element (for example, the card arch) of the carding machine.

By securing the slideway to a lateral support element, particularly to the flexible bend of the carding machine, interfering tension forces and thus undesired radial pressures on the slideway in the concave inlet slideway zone are avoided. In this manner, the entire tension force of the flat bars in the running direction is no longer converted into a circumferential, radially inwardly-directed pressure, so that undesired wear is effectively avoided. It is sufficient to provide the securement at a sole location, particularly at the beginning of the work path of the flats, in a transitional zone between the concave and convex zones of the slideway, in order to avoid undesired tension forces.

It is a particular advantage of the inventive measures that a clearance or air gap between the flat bars on the one hand and the slideway on the other hand is avoided. In case of a rigid slideway such a clearance or air gap cannot be eliminated and can lead to misalignments during run which promptly lead to wear. In case the slideway is rigid and tight, material is being shaved off until again air is present. Then, to the wear caused by the tight run there have to be added misalignments which lead to breaks in the synthetic material and an abrasion of the flats material. The continuous engagement by looping causes a shearing effect which pushes dirt from the track and thus such dirt has a greater difficulty to gain access to and settle between the flat bar and the plastic slideway guide.

FIG. 1 is a schematic side elevational view of carding machine including travelling flats, incorporating the invention.

FIG. 2 is a fragmentary enlarged side elevational detail of the travelling flats shown in FIG. 1, illustrating a preferred embodiment.

FIG. 3 is a side elevational view of the inlet end of a slideway with supporting element according to the invention.

FIG. 4 is a side elevational view of a one-part slideway according to a preferred embodiment of the invention having a relatively thick-walled convex zone and a relatively thin-walled concave zone.

FIG. 5 is a side elevational view similar to FIG. 4, showing a slideway securing device according to a further preferred embodiment of the invention.

FIG. 6 is a side elevational view of a further preferred embodiment of the invention, including an externally positioned support band.

FIG. 6a is a side elevational view of still another preferred embodiment of the invention showing weight application to a free end of the slideway.

FIG. 7 is a schematic side elevational view of a slideway formed of independent slideway zones according to yet another preferred embodiment of the invention.

Turning to FIG. 1, there is illustrated therein a carding machine which may be, for example, an EXACTACARD model, manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Germany. The carding machine has a feed roll 1 and a feed table 2 cooperating therewith, a licker-in 3, a main carding cylinder 4, a doffer 5, a stripping roll 6, crushing rolls 7 and 8, a fiber web guiding element 9, a sliver trumpet 10, calender rolls 1 and 12 as well as travelling flats 13. The direction of rotation of the front and rear flat supporting end rolls 15a and 15b which are tooth belt sprockets, indicated by respective arrows A and B, is opposite the direction of rotation of the main carding cylinder 4, as indicated by the arrow C. The flat bars 14 are advanced in the direction of the arrow D along a working path in a slideway 17 by a toothed belt 16. The beginning of the working path is situated adjacent the end sprocket 15b, whereas the end of the working path is located adjacent the end sprocket 15a. The flat bars 14 are advanced in the reverse direction E on the upper side of the travelling flats 13, opposite the slideway 17. The slideway 17 may be made of ZX 100 plastic which has approximately 80% polyester and has a high strength, small expansion, small propensity for plastic deformation, good dry friction properties and is furthermore wear resistant.

FIG. 2 illustrates in more detail the travelling flats shown in FIG. 1. The flat bars 14 engage the slideway 17 with the underside of the bar ends 14a. The teeth of the sprocket 15b engage the teeth on the inside of the toothed belt 16 and advance the lower flight of the belt 16 in the forward direction as indicated by the arrow D. Similarly, the sprocket 15a engages with its teeth the inside of the toothed belt 16 and advances the upper flight of the belt 16 in the direction of the arrow E. The outside of the toothed belt 16 is form-fittingly connected with that side of each bar end 14a that is remote from the clothing of the flat bar. The belt 16 presses the bar ends 14a onto a convex length portion 17b of the slideway 17. The convex portion 17b follows the curvature of the main carding cylinder 4. Also referring to FIG. 4, the opposite ends of the convex portion 17b are adjoined by concave slideway portions 17a and 17c which follow the curvature of the respective end sprockets 15b and 15a and which maintain the flat bars 14 in position in the course of their circular travel about the periphery of the end sprockets 15a and 15b. The concave slideway portions 17a and 17c may be plastic-coated steel bands. During return travel in the direction of the arrow E, the flat bar ends 14a lie loosely on the outer side of the upper reach of the belt 16. The upper reach is backed by two support rollers 40 and 41 shown in FIG. 1. The lower reach of the belt 16 and the carding cylinder 4 travel in the same direction (arrows C and D).

The slideway is arranged on the card arch 18 and is, at the location 19 which is in the zone of the convex portion 17b adjacent the end sprocket 15b, secured to the flexible bend 18 by a fastening device such as a clamping device or a metal/plastic connection or the like.

The concave portion 17a of the slideway 17 has a linear terminal part 17d of a length d. To the end of the terminal part 17d there is attached one end of a tension spring 21 which, at its other end, is secured to a stationary support 23. The spring 21 has soft spring characteristics to avoid a strong pressure by the concave portion 17a in a radially inward direction. As seen in FIG. 6, at the concave portion 17c, at the sprocket 15a, a similar spring arrangement is provided.

Turning to FIG. 3, on the outside of the concave portion 17a (as well as the non-illustrated concave portion 17c) there is provided a concavely bent support element 20a whose one end is pivoted to the slideway 17 at 20' so that the pressure of the concave portions 17a in the radial direction (as shown by the arrows P) may be adjusted relative to the respective end sprocket 15a or 15b.

Turning to FIG. 4, there is shown therein a one-piece slideway 17 having a relatively thick-walled convex portion 17b having a thickness a which resists expansion and two relatively thin-walled concave portions 17a and 17c which have a thickness b and which are flexible.

Turning to FIG. 5, the concave portion 17c is at its outer side in a shape-conforming engagement with a bent support band 23 made, for example, of steel, whose one end is held in a stationary support 25 while its other end is attached to a fixedly held tension spring 22. Thus, a portion of the band 23 is coaxially looped around the concave portion 17c. By virtue of this arrangement, the radial pressing effect of the concave portion 17c may be adjusted.

In FIG. 6, a support band 26 engages the underside of the convex portion 17b of the slideway 17 The support band 26 is trained about rollers 30a, 30b, 30c and 30d and one of its ends is secured to a stationary support 27 whereas its other end is attached to a tension spring 29 attached to a fixed support 28. According to FIG. 6a, the spring 21 secured to the end of the concave portion 17a is attached to one end of a bellcrank 33 which is pivotally held in a stationary support 32. To the other end of the bellcrank 33 a weight 34 is attached, whereby the bellcrank 33 is urged to rotate about pivot 32 in the direction of the arrow E.

As shown in FIG. 7, the three slideway portions 17a, 17b and 17c of the slideway 17 are separate components. The concave parts 17a and 17c are secured to the flexible bend 18 at locations of attachment 35 and 36, respectively.

Thus, according to the invention, by virtue of the soft-spring arrangements, the concave portions 17a and 17c of the slideway 17 exert only a slight resilient pressure in a radially inward direction and consequently, disadvantageously high loop-around pressures are avoided.

It is to be understood that the securing device which was shown and described as being provided on one side of the card may be duplicated on the other side thereof. An arrangement is feasible wherein the working travel of the flats 14 is opposite to the rotary direction of the carding cylinder 4. In such an arrangement the securement 19 is expediently provided adjacent the sprocket 15a.

It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.