Title of Invention

A METALLIC CARD CLOTHING FOR ROLLERS AND/OR CYLINDERS OF CARDING MACHINES

Abstract

The invention relates to a metallic card clothing for rollers and/or cylinders of carding machines, which rollers or cylinders have a higher circumferential speed of 1500/min and the cylinder metallic card clothing having a total height of < 3 mm and a base width of < 0.7 mm, the metallic card clothing comprising teeth width a positive front angle (a) of more than or equal to 0°, the teeth having a head angle (p) which is > 87°, the length L of the head surface (8) extending at said angle from the tooth tip (5) to the tooth back (70) being at least 15% of the length of the tooth pick.

Full Text

The present invention relates to metallic card clothing for rollers and/or cylinders of cleaners, carding machines, which rollers or cylinders have a higher circumferential speed than rollers arranged upstream in the fiber flow direction, the card clothing having teeth with a positive front angle of =0°. The rollers in question are e.g. licker-ins, strippers or transfer rollers on carding machines, and the cylinders of a carding machine. Said rollers or cylinders actively take over raw fiber material with the front edge of thefront angle of the teeth of the corresponding metallic card clothing. The problem in such card clothings is that positive front angles are needed for ensuring an easy fiber take-over. This, however, tends to make the tooth tip leaner, which makes said card clothings more sensitive during assembly and also during resharpening. Moreover, impurities or dirt in the raw fiber material may be impaled more easily. It is therefore the object of the present invention to provide a metallic card clothing of the above-indicated type which eliminates the drawbacks observed in the prior art while maintaining good take-over properties. The object is achieved in a metallic card clothing of the above-indicated typed in that the teeth have a head angle which is >85°, preferably > 87°, the length of the head surface extending at said angle from the tooth tip to the tooth back being at least 12% of the length of the tooth pitch. The advantages resulting from such a tool shape are that a clogging of the card clothings is prevented on the one hand and that although the card clothing still shows the aggressiveness or activity needed for carding, it is obtuse to contamination. Furthermore, the teeth of the metallic card clothing are more stable and less sensitive during assembly and resharpening. Moreover, in the case of soiled raw fiber materials, such as cotton, and impaling of foreign matter is prevented. As a result, the card clothing need not be cleaned so often. On the whole, it has been found that apart from the advantages to be expected the carding quality is also improved. According to a preferred embodiment the head angle of the tooth is 90 . This has the effect that even after a regrinding of the card clothing the same conditions prevail on all teeth, which in turn improves the carding quality. Morever, it is particularly preferred when the length of the head surface is at least 25% of the tooth pitch. It is further preferred when the length of the head surface is at least three times, preferably five times. the width thereof. Finally, it has been found to be advantageous when the length of the head surface is greater than or equal to half the tooth height, measured from the tooth base to the tooth tip. This yields a relatively low card clothing which surprisingly creates favorable carding conditions. It is particularly preferred when the length of the head surface corresponds to the tooth height. Finally, it is also advantageous when the tooth back adjacent to the head surface encloses an angle between 20 and 30°, preferably 25°, with the subsequent tooth front. This opening angle between tooth back and .................................... tooth front tends to be smaller than in the prior-at card clothings. It is however adequate for ensuring an easy take-over of the fibers from the roller arranged upstream in the work direction. The above-described metallic card clothing is particularly well suited for cylinders of cotton carding machines so-called high-performance carding machines having a circumferential cylinder speed of more than 1500 m/min and a cylinder metallic card clothing having a total height of less than 3 mm and a base width of less than 0.7 mm. Therefore particular protection is sought for such a cotton carding machine equipped with a metallic card clothing according to the invention. Embodiments of the present invention will now be explained in more detail with reference to a drawing, in which: Fig. 1 is a schematic illustration of a carding machine in a side view; Fig. 2 shows the tooth geometry of a metallic card clothing according to a first embodiment; Fig. 3 is a sectional view of the illustration of Fig. 2 along line III-III; Fig. 4 shows the geometry of a metallic card clothing according to a further embodiment; and Fig. 5 is a sectional view taken along line V-V of Fig. 4. Fig. 1 is a schematic illustration showing a carding machine comprising a cylinder, feed rollers 2, a licker-in 3 and strippers 4. The....................................... circumferential rotational direction of the rollers is shown in Fig. 1 by corresponding arrows. The card clothing described in the following refers to such rollers or sylinders that actively take over fibers from rollers arranged upstream in the work direction. These are by way of example the licker-in 3, the strippers 4 and, particularly, cylinder 1 in the illustration shown in Fig. 1. Fig. 2 only shows in sections a sawtooth wire of a metallic card clothing, as is provided for the cylinder shown in Fig. 1. This is a sawtooth wire having a total height of 2 mm and a tooth pitch, measured from the tooth tip 5 to the next one 5', of 1.7 mm. The front angle a of the tooth front 6 measured relative to the vertical is 40º in the illustrated embodiment. In contrast to the formerly known metallic card clothings, the tooth back 7 does not directly follow the tooth tip. Rather, a head surface 8 is first provided. The angle of the head surface surface ß, again measured relative to the vertical, is 87° in the embodiment shown in Fig.2. The length L of the head surface 8 is 0.5 mm, its width B (cf. Fig.3) is 0.07 mm. The tooth height H, measured from the tooth base to the tooth tip 5, is slightly less than 0.5 mm. The angle ? enclosed by the tooth front 6 and the tooth back 7 is 24° in the illustrated embodiment. Figs. 4 and 5 show a further variant of a sawtooth wire for an inventive metallic card clothing. Identical and similar components are provided with the same reference numerals as in the preceding embodiment. In contrast to the former embodiment, the distance between tooth tip 5 and neighbouring tooth tip 5' is just 1.5 mm. The front angle a is just 30°. The angle ? enclosed between tooth front 6 and tooth back 7 is 25° in this embodiment. Operation and function of the above-described embodiments shall now be explained in more detail in the following. The two embodiments do not fundamentally differ from each other. The sawtooth wire shwon in Fig.2 has, however, a larger front angle which is in principle favorable for a more active fiber take-over. Of importance to the two variants is, however, that at a relatively small tooth height a long head surface is provided that is almost not inclined and therefore gives the tooth tip and the whole card clothing an enhanced stability. Apart from these advantages, however, it should be emphasized that the tooth geometry is virtually not changed even after regrinding of the card clothing, so that virtually the same conditions prevail on all teeth on the one hand and the carding quality does not change even after grinding of the card clothings on the other hand. The card clothings are mounted in the conventional way. WE CLAIM 1. A metallic card clothing for rollers and/or cylinders of carding machines, which rollers or cylinders have a higher circumferential speed of 1500/min and the cylinder metallic card clothing having a total height of and a base width of width a positive front angle (a) of more than or equal to 0°, characterized in that the teeth having a head angle (p) which is > 87°, the length L of the head surface (8) extending at said angle from the tooth tip (5) to the tooth back (70) being at least 15% of the length of the tooth pick. 2. The metallic card clothing as claimed in claim 1, wherein the head angle (p) of the tooth is 90°. 3. The metallic card clothing as claimed in claim 1 or 2, wherein the length (L) of the header surface (8) is at least a quarter of the tooth pitch. 4. The metallic card clothing as claimed in any one of the claims 1 to 3, wherein the length (I) header surface (8) is at least three times, preferably five times the width (8) thereof. 5. The metallic card clothing as claimed in any one of the claims 1 to 4, wherein the length (I) header surface (8) is greater than or equal to half the tooth height (H), measured from the tooth base to the tooth tip (5). 6. The metallic card clothing as claimed in any one of the claims 1 to 5, wherein the tooth back (7) adjacent to the head surface (8) enclosed an angle (Y) between 20° and 30°, preferably 25°, with the subsequent tooth front (6). 7. The metallic card clothing as claimed in any one of the claims 1 to 6, wherein the tooth height (H) is smaller than/equal to 0.5mm. The invention relates to a metallic card clothing for rollers and/or cylinders of carding machines, which rollers or cylinders have a higher circumferential speed of 1500/min and the cylinder metallic card clothing having a total height of mm and a base width of width a positive front angle (a) of more than or equal to 0°, the teeth having a head angle (p) which is > 87°, the length L of the head surface (8) extending at said angle from the tooth tip (5) to the tooth back (70) being at least 15% of the length of the tooth pick.

Documents:

1231-KOLNP-2005-FORM 27.pdf

1231-kolnp-2005-granted-abstract.pdf

1231-kolnp-2005-granted-claims.pdf

1231-kolnp-2005-granted-correspondence.pdf

1231-kolnp-2005-granted-description (complete).pdf

1231-kolnp-2005-granted-drawings.pdf

1231-kolnp-2005-granted-examination report.pdf

1231-kolnp-2005-granted-form 1.pdf

1231-kolnp-2005-granted-form 13.pdf

1231-kolnp-2005-granted-form 18.pdf

1231-kolnp-2005-granted-form 2.pdf

1231-kolnp-2005-granted-form 26.pdf

1231-kolnp-2005-granted-form 3.pdf

1231-kolnp-2005-granted-form 5.pdf

1231-kolnp-2005-granted-reply to examination report.pdf

1231-kolnp-2005-granted-specification.pdf