Conical winding of elongated material

Abstract

An arrangement of elongated material wound in a plurality of layers on a spool having a cylindrical core, a bottom flange and a top flange. A first series of layer form a conical basis of elongated material on the core where elongated material is present at the bottom flange in a larger amount than at the top flange. A second series of layers is wound over the conical basis. The conical basis is formed by a first layer being wound on the cylindrical core between the bottom flange and the top flange in a first number of windings, a second layer being wound on the first layer in a second number of windings being equal to or smaller than the first number of windings, the second layer reaching the bottom flange, where additional layers are wound on the second layer in numbers of windings.

Claims

1. An arrangement of elongated material wound in a plurality of layers on a spool, said spool comprising a cylindrical core, a bottom flange and a top flange, a first series of layers forming a conical basis of elongated material on the core so that elongated material is present at the bottom flange in a larger amount than at the top flange, a second series of layers being wound over the conical basis and extending from the bottom flange to the top flange thereby keeping a conical form of the wound elongated material, wherein the conical basis is formed by: a first layer being wound on the cylindrical core between the bottom flange and the top flange in a first number of windings, a second layer being wound on the first layer in a second number of windings, said second number of windings being equal to or smaller than the first number of windings, said second layer reaching the bottom flange but not necessarily the top flange, additional layers being wound on the second layer in numbers of windings where these numbers of windings decrease on average as the conical basis is being formed, said additional layers reaching the bottom flange.

2. The arrangement according to claim 1, wherein the top flange is conical.

3. The arrangement according to claim 2, wherein the bottom flange is conical.

4. The arrangement according to claim 3, wherein said bottom flange and said top flange form an angle with a plane that is perpendicular to the cylindrical core, said angle ranging from 10 to 40.

5. The arrangement according to claim 1, wherein the elongated material is a metal wire or a metal cord.

6. The arrangement according to claim 1, wherein the elongated material has a tensile strength less than 1000 MPa.

7. The arrangement according to claim 6, wherein the elongated material is an annealed low-carbon steel wire.

8. The arrangement according to claim 1, wherein said elongated material has a diameter ranging from 0.15 mm to 2.20 mm.

9. The arrangement according to claim 1, wherein said conical basis forms an angle with the cylindrical core, said angle ranging from 1 to 15.

10. A method of winding a plurality of layers of an elongated material on a spool, said method comprising the following steps: providing a spool with a cylindrical core, a bottom flange and a top flange; forming a conical basis on the cylindrical core with a first series of layers by: winding a first layer between the bottom flange and the top flange in a first number of windings; winding a second layer in a second number of windings, said second number of windings being equal to or smaller than the first number of windings, said second layer reaching the bottom flange but not necessarily the top flange; winding additional layers on the second layer in numbers of windings, where these numbers of windings decrease on average as the conical basis is being formed, said additional layers reaching the bottom flange.

11. The method according to claim 10, the method further comprising the step of: winding a second series of layers over the conical basis and extending between from the bottom flange to the top flange thereby keeping a conical form of the wound elongated material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 gives a schematic view of the prior art of conical winding.

(2) FIG. 2a illustrates how the conical basis the conical winding according to the invention is built and FIG. 2b illustrates how the process of winding is carried out after building the conical basis.

(3) FIG. 3 illustrates in more detail the building of the conical basis according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(4) FIG. 1 shows a prior art embodiment 100 of metal wire 101 conically wound on a spool 102. The spool 102 has a cylindrical core 104, a conical bottom flange 106 and a conical top flange 108. The windings of wire 101 are forming conical layers, starting with a short mounting layer 110, followed by a somewhat longer descending layer 112, a mounting layer 114 greater in length than the previous layer 112, a descending layer 116 again great in length than the previous layer 114, a mounting layer 118 greater in length than the previous layer 116, a descending layer 120 greater in length than the previous layer 118, and so on until a conical basis is formed.

(5) This way of conical winding with conical layers 110-120 may lead to unwinding problems, particularly in case of stationary unwinding. Stationary unwinding is a way of unwinding whereby the spool stands still, i.e. the spool is not rotating. The wire 101 is unwound over the top flange 108, e.g. over a ring 122 or over a pay-off installation as disclosed in U.S. Pat. No. 5,028,013. During the unwinding operation, the wire 101 receives a twist per rotation or per winding. The unwinding problems are likely to occur when at the same time the wire 101 to be unwound is close to the core 104 and the angle between the wire 101 and the top flange 108 is small. The smaller the angle , the greater the tension in the wire 101. More precisely, problems occur not when the wire 101 is very close to the top flange 108, but when the wire 101 is at a distance of 3 to 8 cm from the top flange 108.

(6) Due to a combined effect of the greater tension in the wire 101, the twist given to the wire 101 and the swinging effect of the wire 101, previous windings may jump up and over following windings leading to windings being clamped. When it comes up to these windings to be unwound, the tension in the wire 101 increases leading to vibrations of the spool 102 and even to fractures of the wire 101.

(7) As shown on FIG. 1, the risk for fractures occurs at a moment where the complete conical basis still is to be unwound, i.e. at a moment when there is still a substantial amount of wire 101 on the spool 102.

(8) FIG. 2a shows a right side of a spool 102 and building up of layers according to the invention.

(9) A first pair of layers 202, 204 extends between the bottom flange 106 and the top flange 108: a mounting layer 202 and a descending layer 204. The second pair of layers 206, 208 starts from the bottom flange 106, but does not reach until the top flange 108. This second pair of layers 206, 208 has less number of windings than the first pair of layers 202, 204. The third pair of layers 210, 212 also starts from the bottom flange 106 and has less number of windings than the second pair of layers 206, 208. This goes on until a conical basis 214 has been formed.

(10) FIG. 2b illustrates the continuation of the winding process. After formation of the conical basis, the followings layers 216, 218, 220 and 222 all extend between the bottom flange 106 and the top flange 108.

(11) FIG. 3 illustrates winding per winding the way of building up the conical basis 214. The circles with a cipher 1 inside refer to windings of the first mounting layer 202, the circles with a cipher 2 inside refer to windings of the second descending layer 204, the circles with a cipher 3 inside refer to windings of the third mounting layer 206, the circles with a cipher 4 inside refer to windings of the fourth descending layer 208, the circles with a cipher 5 inside refer to the windings of the fifth mounting layer 210 and the circles with a cipher 6 inside refer to windings of the sixth descending layer 212.

(12) The advantage of the invention is explained as follows. As mentioned, problems with unwinding are likely to occur when at the same time the wire to be unwound is close to the core 104 and the angle is small. Referring to FIG. 2a as well as to FIG. 3, this occurs in the first pairs of layers, e.g. 202, 204. This means that problems such as vibrations or fracture of the wire may occur at a moment in time when the spool is almost empty. This is in big contrast with the prior art where the problems are likely to occur at the beginning of the unwinding of the complete conical basis.

(13) FIGS. 1, 2a, 2b and 3 are only for illustrations. In practice the number of layers needed to make the conical basis may be larger. It all depends upon the geometry of the spool, more particularly the height of the spool, the winding pitch, and the angle formed by the conical basis with the core of the spool and the diameter of the elongated material.

(14) The height of the spool may range from 100 mm to 500 mm and more, e.g. from 200 mm to 450 mm.

(15) Winding tensions vary and depend upon the breaking load of the elongated material. Low carbon steel wires of 0.25 mm may be wound with a winding tension of 2 Newton, low carbon steel wires of 0.65 mm may be wound with a winding tension of 10 Newton.

(16) The winding pitch may range from 1 mm to 5 mm, e.g. from 2 mm to 4 mm. Anyway, the winding pitch is greater than the diameter of the elongated element.

(17) In order to have an angle of 2 with a spool height of 300 mm, the number of layers needed to make this conical basis mainly depends upon the diameter of the elongated material and may vary between 5 layers (big diameter of more than 0.65 mm) and more than 100 layers (small diameter less than 0.23 mm).

LIST OF REFERENCE NUMBERS

(18) 100 arrangement of spool and wire

(19) 101 wire

(20) 102 spool

(21) 104 core

(22) 106 bottom flange

(23) 108 top flange

(24) 110 first mounting layer

(25) 112 second descending layer

(26) 114 third mounting layer

(27) 116 fourth descending layer

(28) 118 fifth mounting layer

(29) 120 sixth descending layer

(30) 122 guiding ring

(31) 202 first mounting layer

(32) 204 second descending layer

(33) 206 third mounting layer

(34) 208 fourth descending layer

(35) 210 fifth mounting layer

(36) 212 sixth descending layer

(37) 214 conical basis

(38) 216-218-220-222 layers upon conical basis