Sawtooth clothing for a card or carding machine
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-02-08
- Publication Date
- 2026-04-01
AI Technical Summary
Existing sawtooth sets for cards or carding machines suffer from suboptimal fiber transfer between the drum and doffer or worker roller due to fiber adhesion in recesses, leading to inefficient fiber guidance and transport.
The sawtooth set features teeth with wave-shaped depressions on the tooth face, increasing in size from the tip to the base, connected by convex radii, which enhance fiber transport by increasing pressure and adhesion at the tooth tip, while maintaining curvature and avoiding zero radii or edges, allowing for efficient fiber transfer.
This design significantly improves the transmission factor between rollers, reducing fiber damage and enhancing adhesion, resulting in improved fiber processing efficiency and longer service life without compromising stability.
Smart Images
Figure EP2024053255_28112024_PF_FP_ABST
Abstract
Description
[0001] Title: Sawtooth set for a carding machine or card
[0002] Description
[0003] The invention relates to a sawtooth set for a carding machine or carding machine with a tooth base and a plurality of successively arranged teeth which rise above the tooth base, wherein each tooth has a tooth face, a tooth tip and a tooth back and each tooth back merges into the tooth face of the following tooth via a rounded tooth base, according to the preamble of claim 1.
[0004] EP 2756119 B1 discloses a clothing for an edging roller on a carding machine or a clothing for the doffer of a carding machine with at least one recess in the tooth face. This clothing has the disadvantage that an increased number of fibers adhere to the recesses on the tooth face, which results in suboptimal fiber transfer between the cylinder and the doffer or between the cylinder and the worker roller.
[0005] The object of the invention is to improve the transmission factor between the cylinder and the doffer on the carding machine, or between the cylinder and the worker roller or turner roller on the carding machine. In particular, the guiding or transport of the fibers from the tooth base to the tooth tip is to be improved so that they can be more easily taken over by the subsequent roller set. At the same time, the fiber adhesion at the tooth tip is to be increased.
[0006] This object is achieved by a sawtooth assembly according to the preamble of claim 1 with the characterizing features. Advantageous developments of the invention are specified in the dependent claims.
[0007] The sawtooth clothing for a carding machine or carding machine has a tooth base and a plurality of successively arranged teeth that rise above the tooth base. Each tooth has a tooth face, a tooth tip, and a tooth back, and each tooth back transitions into the tooth face of the following tooth via a rounded tooth base.
[0008] The invention provides that each tooth has at least two, preferably at least three wave-shaped depressions in its tooth face (wave trough), which increase in size with increasing distance from the tooth tip, wherein the depressions are each formed by first radii, wherein at least two first radii are each directly or indirectly connected by a further second radius (wave crest). The tooth face can preferably have between two and five depressions. The depressions are designed as concave recesses in the tooth face, the contour of which is formed by a constant first radius. The concave recesses or depressions are directly or indirectly connected by convex second radii, so that the fibers are transported smoothly to the tooth tip.
[0009] The first depression in the area of the tooth tip can be at a distance (X1) from the tooth face, and each subsequent depression with increasing distance from the tooth tip can be at least 40% greater (X2, X3) from the tooth face than the previous depression. The depressions or troughs become larger towards the base of the tooth and accumulate more fibers there. Or conversely, because the depressions at the tooth tip are each a smaller distance from the tooth face, they fill with fibers more quickly, which increases the pressure for transporting the fibers to the tooth tip. The state of the art provides for depressions with a constant distance from the tooth face, which means that the amount of fiber in the depressions does not change. Only the geometry of the depression, not its decreasing size towards the tooth tip, causes fiber transport.
[0010] Preferably, the first radius of the concave recess forming the depression is a maximum of 0.16 mm, preferably a maximum of 0.15 mm, and particularly preferably a maximum of 0.12 mm. Thus, the concave recesses of the depressions (wave troughs) have a greater curvature than is known from the prior art. The greater curvature also results in increased transport of the fibers to the tooth tip, without the curvature being able to end at a zero radius or at an edge.
[0011] It is advantageous for the second radius (wave crest) connecting the depressions (wave trough) to be at most equal to the size of the first radii of the depressions. The fibers glide evenly to the tooth tip, reversing their direction (vertical-horizontal-vertical).
[0012] Horizontal and vertical sections can be arranged between the first radii of the depressions (wave trough) and the connecting second radius (wave crest), which increase in size with increasing distance from the tooth tip. This allows the increasing depression or concave recess to be realized toward the tooth base while maintaining constant radii. At the same time, the sections can additionally support fiber transport. The sections can be straight or curved.
[0013] For this purpose, the horizontal sections can each be inclined at an angle to the horizontal toward the tooth tip, so that the fibers from the concave recess or depression are continuously transported to the tooth face for transfer to the next depression. The same applies to the vertical connecting sections, which are advantageously inclined at an angle to the vertical into the depression, so that the fibers are pushed from the wave crest, i.e., the convex second radius on the tooth face, into the next higher depression.
[0014] The tooth face can have a face angle to the vertical of 35° to 45°, preferably 40°, which makes the sawtooth clothing aggressive on cotton and fiber blends.
[0015] The face angle at the tooth tip can be between 45° and 55°, preferably 50°, relative to the vertical, with the transition into the extended tooth face occurring continuously through a radius (r). The resulting additional inclination of the tooth tip into the tooth face holds the fibers on the outermost circumference of the clothing wound onto the roller before transfer.
[0016] Preferably, the tooth back can have a first straight or convex section that transitions into a second convex section at the tooth tip. The combination of the second, more inclined convex section of the tooth back with the more aggressive face angle at the tooth tip results in high efficiency in processing the fibers with a long service life, without compromising the stability of the teeth.
[0017] Preferably, the first straight or convex section of the tooth back has an angle of 50° - 70° to the vertical.
[0018] Surprisingly, it has been shown that fiber damage can be reduced if the width of the teeth at the tooth tip (top profile thickness) is proportional to the size of the first indentation. This applies, for example, to an average fiber length between 30 mm and 60 mm, as in cotton or PET / CV blends. The depth of the first indentation, which is assigned to the tooth tip, can be at least a quarter of the top profile thickness Y. With this ratio, tests have shown that fiber damage is minimized during the transfer of the fibers to the clothing of a subsequent roll.
[0019] The sawtooth clothing is preferably used on a worker roller or turner roller of a carding machine, or on a doffer of a card.
[0020] The sawtooth clothing according to the invention increases the transfer factor between the cylinder and the doffer on the card. When used on a carding machine between the cylinder and the worker roller or turner roller, the adhesion of the fibers to the tooth tip is improved. The decreasing size of the depression (wave trough) from the tooth base to the tooth tip causes an increase in pressure on the fiber volume, so that the fibers are inevitably transported to the tooth tip.
[0021] Further measures improving the invention are described in more detail below together with the description of a preferred embodiment of the invention with reference to the figures.
[0022] They show:
[0023] Fig. 1a -1b: a schematic view of the fitting according to the invention in a side view and a sectional view;
[0024] Fig. 2a - 2c: an enlarged view of the individual tooth geometry.
[0025] Figures 1a and 1b show a section of a clothing 1 with a tooth root 2 and, here, three teeth 3, which can have a length of several hundred meters in one manufacturing process. The tooth root has a width B and a height H1. On a first side 8 of the clothing 1, the tooth root 2 merges into the tooth 3 without interruption or step, where it forms a vertical surface. On the opposite second side 9, the tooth root 2 merges into the tooth 3 via a first inclined step and a radius, which tapers towards the tooth tip 7. Between the adjacent teeth 3 of the clothing 1 wound onto a roller, there is a free space for the fibers to be processed.
[0026] Each tooth 3 has a tooth back 4, a tooth tip 7 and a tooth face 5, wherein the tooth face 5 merges via a tooth base 6 into the tooth back 4 of a tooth 3 arranged in front of it. The tooth base 6 merges at a radius R from the tooth back 4 into the subsequent tooth face 5. The tooth back has a first section 4.1 which, starting from the tooth base 6, forms a straight or slightly convex contour. The first section of the tooth back 4.1 is followed by a second section 4.2 of the tooth back which is convex and ends in the tooth tip 7. The tooth back 4 can, for example, be arranged or inclined at an angle E of 50° to 70° to the vertical.
[0027] The tooth face 5 has an angle a of 35° to 45°, preferably 40° to the vertical.
[0028] The teeth have a spacing L at the tooth tips 7, which can be between 2 mm and 4 mm. The tooth base 2 can have a height H1 of 0.7 mm and 1.5 mm. The height H of the set 1 can be between 2.5 mm and 5 mm. At the tooth tip 7, the set 1 can have a width Y of at least 0.25 mm.
[0029] For an average fiber length between 30 mm and 60 mm, for example, with cotton or PET / CV blends, a surprising correlation has been found between the width Y of the clothing at tooth tip 7 (upper profile thickness) and the depth of a first depression V1. The depth X1 of the first depression V1, which is assigned to tooth tip 7, should be at least a quarter of the upper profile thickness Y; in this example, with Y=0.25 mm, X1 should be at least 0.06 mm. With this ratio, tests have shown that fiber damage is minimized during the transfer of the fibers to the clothing of a subsequent roller.
[0030] According to Figures 2a-2c, the sawtooth set has at least two wave-shaped depressions V1, V2 in the tooth face 5, preferably at least three wave-shaped depressions V1, V2, V3 in the tooth face 5, in which the depressions V1, V2, V3 have a greater curvature, i.e., a smaller first radius, than in the prior art. For this purpose, a small first radius R1=R2=R3 is used, which is a maximum of 0.16 mm, preferably a maximum of 0.15 mm. Preferably, the first radius can be a maximum of R1=R2=R3=0.12 mm. With increasing distance from the tooth tip 7, the wave-shaped depressions V1, V2, V3 are more pronounced and thus arranged deeper in the tooth face 5, whereby each depression V1, V2, V3 increases from the tooth tip 7 by at least 40% compared to the previous depression in the depth X1, X2, X3 to the tooth face 5 or in the distance from the tooth face 5: 1.4 x X1 = X2, 1.4 x X2 = X3.For example, the first recess V1 can have a first distance X1 of 0.06 mm to 0.1 mm from the tooth face 5. The second recess V2 then has a distance X2 of 0.08 mm to 0.14 mm from the tooth face 5. The third recess V3 can have a distance X3 of 0.12 mm to 0.2 mm from the tooth face 5.
[0031] Viewed in profile, the depressions V1 - V3 form a wave trough, and the connecting second radius RB on the tooth face 5 between the depressions V1 - V3 forms a wave crest. The wave troughs of the depressions V1 - V3 are formed by the corresponding first radii R1 - R3. The second radii RB and the first radii R1 - R3 can be directly connected to one another or indirectly connected by straight or curved sections A1.1, A1.2, A2.1, A2.2, A3.1, A3.2, which have a different length and inclination to the vertical or horizontal.
[0032] The transition of the first radii R1, R2, R3 to the second radius RB of the tooth face in the tooth face 5 can be straight at least in a short section A1.1 ... A3.2 and thus inclined to the vertical A1.2, A2.2, A3.2 or horizontal A1.1, A2.1, A3.1, so that the fibers are always inevitably transported to the tooth tip 5. The sections from the tooth tip 5 to the tooth base 6 become increasingly longer. The sections A1.1, A2.1, A3.1 are inclined by the respective associated angle y y2 and y3 by at least 5°, maximum 10° to the horizontal upwards to the tooth tip 7 in order to improve fiber transport to the tooth tip 7. The theoretical right angle between the horizontal sections A1.1, A2.1, A3.1 and the vertical sections A1.2, A2.2, A3.2 is increased by the angles y1, Y2 and y3.
[0033] The vertical sections A1.2, A2.2, and A3.2 are inclined by the corresponding angles Ö1, Ö2, and Ö3, from a minimum of 1° to a maximum of 8° to the vertical, so that the theoretical right angle between the horizontal sections A1.1, A2.1, and A3.1 and the vertical sections A1.2, A2.2, and A3.2 is reduced by the angles Ö1, Ö2, and Ö3. This contributes to the fibers first entering the first radius R1-R3 and then being transported further to the tooth tip. The transfer of the fibers to the clothing of the subsequent roller is improved.
[0034] Starting from the first depression V1, the tooth tip 7 has an even greater inclination ß of 45° to 55° to the vertical, preferably 50° to the vertical, whereby the fibers adhere to the tooth tip 5 and thus the transfer of the fibers to the clothing of the subsequent roller is improved. The transfer factor between the rollers is thus increased. The transition into the extended tooth face 5 can be continuous through a radius r. Due to the associated additional inclination of the tooth tip 7 into the tooth face 5, the fibers are held on the outermost circumference of the clothing wound onto the roller before the transfer.
[0035] The invention has the advantage that the transmission factor increases with higher speeds of the worker and turner rollers on the carding machine or the fiber transfer on the carding machine between the drum and the doffer increases.
[0036] Reference symbol
[0037] 1 set
[0038] 2 tooth base
[0039] 3 tooth
[0040] 4 tooth backs
[0041] 4.1 , 4.2 Sections of the tooth back
[0042] 5 Tooth breast
[0043] 6 Tooth base
[0044] 7 Tooth tip
[0045] 8 first page
[0046] 9 second page
[0047] A1.1 ...A3.2 sections
[0048] B Width tooth base
[0049] H Set height
[0050] H1 Foot height
[0051] H2 tooth height
[0052] L Distance between teeth r Radius Tooth tip
[0053] R radius tooth base
[0054] R1 , R2, R3 first radius recess
[0055] RB second radius tooth breast
[0056] V1. V2. V3 In-depth
[0057] X1, X2, X3 distance
[0058] Y Tooth width at the tooth tip a Angle of tooth face ß Angle of tooth tip y1 , y2, y3 Inclination of recess V to the horizontal
[0059] Ö1 , ö2, ö3 Inclination of recess V to the vertical
[0060] £ Angle tooth back
Claims
Patent claims 1 . Sawtooth clothing for a carding machine or carding machine with a tooth base (2) and a plurality of successively arranged teeth (3) which rise above the tooth base (2), each tooth (3) having a tooth face (5), a tooth tip (7) and a tooth back (4) and each tooth back (4) merging into the tooth face (5) of the following tooth (3) via a rounded tooth base (6), characterized in that each tooth (3) has at least two, preferably at least three wave-shaped depressions (V1, V2, V3) in its tooth face (5) (wave trough), which increase in size with increasing distance from the tooth tip (7), the depressions (V1, V2, V3) being formed by first radii (R1, R2, R3), at least two first radii (R1, R2 or R2, R3) being connected directly or indirectly by a second radius (RB) each (wave crest).
2. Sawtooth set according to claim 1, characterized in that the first depression (V1) in the region of the tooth tip (7) has a distance (X1) from the tooth face (5), and each further depression (V2, V3) with increasing distance from the tooth tip (7) has a distance (X2, X3) from the tooth face (5) that is at least 40% greater than the previous depression (V1, V2).
3. Sawtooth set according to claim 1, characterized in that the first radius (R1, R2, R3) forming the recess (V1, V2, V3) is a maximum of 0.16 mm, preferably a maximum of 0.15 mm, particularly preferably a maximum of 0.12 mm.
4. Sawtooth set according to claim 1, characterized in that the second radius (RB) connecting the recesses (V1, V2, V3) has at most the size of the first radii (R1, R2, R3) of the recesses (V1, V2, V3).
5. Sawtooth set according to claim 1, characterized in that horizontal and vertical sections (A1.1, A1.2, A2.1, A2.2, A3.1, A3.2) are arranged between the first radii (R1, R2, R3) and the second radii (RB), which sections increase in size with increasing distance from the tooth tip (7).
6. Sawtooth set according to claim 5, characterized in that the horizontal sections (A1.1 - A3.1) are each inclined by an angle (y1, y2, y3) to the horizontal to the tooth tip (7).
7. Sawtooth set according to claim 5, characterized in that the vertical sections (A1.2 - A3.2) are each inclined by an angle (Ö1, ö2, ö3) to the vertical into the recess (V1, V2, V3).
8. Sawtooth set according to claim 1, characterized in that the tooth face (5) has a face angle (a) to the vertical of 35° to 45°, preferably 40°.
9. Sawtooth set according to claim 1, characterized in that the breast angle (ß) at the tooth tip (7) has an angle of 45° to 55°, preferably 50°, to the vertical.
10. Sawtooth set according to claim 1, characterized in that the tooth back (4) has a first straight or convex section (4.1) which merges into a second convex section (4.2) at the tooth tip (7).
11. Sawtooth set according to claim 10, characterized in that the first straight or convex section (4.1) of the tooth back forms an angle (E) of 50° to the vertical - 70° iced up.
12. Sawtooth clothing according to claim 2, characterized in that the distance (X1) of the first recess (V1) is at least 25% of the tooth width (Y) at the tooth tip (7).
13. Sawtooth clothing according to one of the preceding claims, designed for use on a worker roller or turner roller of a carding machine, or for use on a doffer of a carding machine.