Card wire

Abstract

A card wire has consecutive teeth spaced apart in the longitudinal direction by a pitch. The teeth are bounded in the longitudinal direction by a tooth face on a first side and by a tooth back on a second side. Looking downwards in the height direction of the card wire, the tooth face and the tooth back of consecutive teeth merge in a tooth base and, looking upwards in the height direction, form a tooth tip. The tooth depth is defined by the greatest distance, in the height direction of the card wire, from the tooth tip to the tooth base. The ratio of pitch to tooth depth is less than 1.1. An interspace, measured at right angles to a tangent to an inflection point between tooth back and tooth base, between this inflection point and the opposite tooth face is greater than a quarter of the pitch.

Claims

1. Card wire (1) comprising in its longitudinal direction (L), consecutive teeth (2) which are spaced apart in the longitudinal direction (L) by a pitch (3), wherein the teeth (2) are bounded in the longitudinal direction (L) by a tooth face (4) on a first side and by a tooth back (5) on a second side, wherein, looking downwards in a height direction (H) of the card wire (1), the tooth face (4) and the tooth back (5) of consecutive teeth (2) merge in a tooth base (6) and, looking upwards in the height direction (H) of the card wire (1), form a tooth tip (8), wherein a tooth depth (7) is defined by a greatest distance, in the height direction (H) of the card wire (1), from the tooth tip (8) to the tooth base (6), wherein a ratio of pitch (3) to tooth depth (7) is less than 1.1, wherein an interspace (9), measured at right angles to a tangent to an inflection point (10) between tooth back (5) and tooth base (6), between this inflection point (10) and an opposite tooth face (4) is greater than a quarter of the pitch (3), wherein the tooth base (6) is shaped as an arc having a radius greater than one or both of one eighth of the pitch (3) or 0.4 mm.

2. Card wire (1) according to claim 1, wherein the pitch (3) is less than 3.2 mm.

3. Card wire (1) according to claim 1, wherein an angle enclosed by the tooth face (4) and the longitudinal direction (L) is between 45° and 65°.

4. Card wire (1) according to claim 1, wherein the tooth back (5) comprises at least two straight sections, wherein one straight section of the at least two straight sections, which borders on the tooth base (6), encloses a larger angle with the longitudinal direction (L) than does another of the at least two straight sections.

5. Card wire (1) according to claim 4, wherein a maximum extent of the straight section bordering on the tooth base (6) is 50% of the tooth depth (7).

6. Card wire (1) according to claim 1, wherein the tooth face (4) has an undercut (11).

7. Card wire (1) according to claim 6, wherein the undercut (11) in the tooth face (4) encloses an angle of 0° to 45° with the longitudinal direction (L).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a card wire according to the prior art.

(2) FIG. 2 shows an embodiment of a card wire according to the invention.

(3) FIG. 3 shows an enlarged detail from FIG. 2.

DETAILED DESCRIPTION

(4) FIG. 1 shows a card wire (1) according to the prior art. It shows a section of a card wire comprising 4 teeth (2). The card wire (1) is shown in a view perpendicular to the longitudinal direction (L) and perpendicular to the height direction (H). The pitch (3) and the tooth depth (7) are shown with arrows. The pitch (3) is measured in the longitudinal direction (L), the tooth depth in the height direction (H). The reference lines for the arrow showing the pitch (3) start from two tooth tips (8) of consecutive teeth (2). The arrow showing the tooth depth (7) runs between the deepest point of a tooth base (6) and a reference line, which again starts from a tooth tip (8). The card wire (1) illustrated has an undercut (11). Below the undercut (11), the tooth back (5) and the tooth face (4) are straight. Above the undercut (11), in the direction of the tip, the tooth back (5) and the tooth face (4) have differing portions.

(5) The card wire according to the invention, shown in FIG. 2, corresponds for the most part to the card wire of FIG. 1. In the tooth base (6), the card wire (1) has an interspace (9), which exceeds a quarter of the pitch (3). The interspace (9) is measured from an inflection point (10) at the transition between the tooth base (6) and the tooth back (5) to the face (4) of the next tooth. For better clarity, a detail from FIG. 2 is shown enlarged in FIG. 3.

(6) FIG. 3 shows two teeth (2) of a card wire (1) according to the invention. The foot segment is no longer shown in full, but has been cut off at the lower edge of FIG. 3. It is particularly evident that, starting from the inflection point (10), the interspace (9) is measured at an angle of 90° to the tangent at the inflection point (10). The tooth base (6) is circular-arc-shaped and transitions tangentially into the tooth back (5). Starting from the inflection point (10) in the upward direction, the tooth back (5) is straight. The angle of the tangent at the inflection point (10), at which the circular arc of the tooth base (6) transitions tangentially into the bordering straight section of the tooth back (5), does not change over the entire first straight section of the tooth back (5). This means that the inflection point (10), in accordance with its definition, is fixed non-ambiguously at the position shown. The straight section bordering on the tooth base (6) encloses a larger angle (12) with the longitudinal direction (L) than the angle (13) formed by a straight section further up. The angle (14) formed by the tooth face (4) is shown for the sake of completeness.

(7) TABLE-US-00001 List of reference numerals 1 Card wire 2 Tooth 3 Pitch 4 Tooth face 5 Tooth back 6 Tooth base 7 Tooth depth 8 Tooth tip 9 Interspace 10 Inflection point 11 Undercut 12 Angle formed by the straight portion, bordering on the tooth base, of the tooth back 13 Angle formed by another straight portion 14 Angle formed by the tooth face L Longitudinal direction of the card wire H Height direction of the card wire