Source: http://www.google.com/patents/US5461850?dq=7,403,220
Timestamp: 2018-01-17 08:28:20
Document Index: 572060481

Matched Legal Cases: ['art 38', 'art 40', 'art 38', 'art 40', 'art 40', 'art 38']

Patent US5461850 - Multi-strand steel cord having a core and peripheral strands surrounding the ... - Google Patents
A steel cord (10) has a diameter D and includes a core strand (12) and up to nine peripheral strands (14) surrounding the core strand. The core strand (12) has a diameter D1 and the peripheral strands (14) have a diameter D2. The ratio core strand diameter to peripheral strand diameter D1/D2 is greater...http://www.google.com/patents/US5461850?utm_source=gb-gplus-sharePatent US5461850 - Multi-strand steel cord having a core and peripheral strands surrounding the core
Publication number US5461850 A
Application number US 08/160,293
Also published as CA2109904A1, CA2109904C, CN1043536C, CN1091791A, DE69315181D1, DE69315181T2, EP0602733A1, EP0602733B1
Publication number 08160293, 160293, US 5461850 A, US 5461850A, US-A-5461850, US5461850 A, US5461850A
Inventors Pol Bruyneel, Luc Bourgois
Patent Citations (11), Non-Patent Citations (4), Referenced by (54), Classifications (33), Legal Events (5)
US 5461850 A
A steel cord (10) has a diameter D and includes a core strand (12) and up to nine peripheral strands (14) surrounding the core strand. The core strand (12) has a diameter D1 and the peripheral strands (14) have a diameter D2. The ratio core strand diameter to peripheral strand diameter D1/D2 is greater than a predetermined value in order to enable rubber penetration. Each strand has a center of one or more center filaments (16, 22) and two or more layers of filaments (18, 20, 24, 26) surrounding the center. The twist angle of a radially outer layer is smaller than the twist angle of a radially inner layer of the same strand. A first free space (28) ranging from 0.0015×D to 0.0075×D is provided in at least the core strand between each pair of filaments (18) of the radially most inner layer.
1. A steel cord having a diameter D and comprising a core strand and up to six peripheral strands surrounding the core strand, the core strand having a diameter D1 and the peripheral strands having a diameter D2, a ratio of the core strand diameter to the peripheral strand diameter D1/D2 being greater than 1.05, each strand comprising a center of one or more center filaments and two or more layers of filaments surrounding the center, all the filaments of each layer having substantially the same diameter, a radially outer layer having a twist angle which is smaller than a twist angle of a radially inner layer of the same strand, the twist angle of each layer being determined by the diameters and a lay length of the filaments, a first free space ranging from 0.0015×D to 0.0075×D being provided in at least the core strand between each pair of filaments of the radially most inner layer.
4. A steel cord according to claim 1 wherein the first free space ranges from 0.002×D to 0.007×D.
6. A steel cord according to claim 5 wherein the second free space ranges from 0.003×D to 0.015×D.
20. A steel cord having a diameter D and comprising a core strand and up to five peripheral strands surrounding the core strand, the core strand having a diameter D1 and the peripheral strands having a diameter D2, a ratio of the core strand diameter to the peripheral strand diameter D1/D2 being greater than 0.70, each strand comprising a center of one or more center filaments and two or more layers of filaments surrounding the center, all the filaments of each layer having substantially the same diameter, the filament diameter in each layer being smaller than a total diameter of the center of the same strand, the filament diameter in a radially outer layer being smaller than the filament diameter in a radially inner layer of the same strand, a twist angle of a radially outer layer being smaller than a twist angle of a radially inner layer of the same strand, the twist angle of each layer being determined by the diameters and a lay length of the filaments, a first free space ranging from 0.0015×D to 0.0075×D being provided in at least the core strand between each pair of filaments of the radially most inner layer.
21. A steel cord having a diameter D and comprising a core strand and up to seven peripheral strands surrounding the core strand, the core strand having a diameter D1 and the peripheral strands having a diameter D2, a ratio of the core strand diameter to the peripheral strand diameter D1/D2 being greater than 1.39, each strand comprising a center of one or more center filaments and two or more layers of filaments surrounding the center, all the filaments of each layer having substantially the same diameter, a twist angle of a radially outer layer being smaller than a twist angle of a radially inner layer of the same strand, the twist angle of each layer being determined by the diameters and a lay length of the filaments, a first free space ranging from 0.0015×D to 0.0075×D being provided in at least the core strand between each pair of filaments of the radially most inner layer.
22. A steel cord having a diameter D and comprising a core strand and up to eight peripheral strands surrounding the core strand, the core strand having a diameter D1 and the peripheral strands having a diameter D2, a ratio of the core strand diameter to the peripheral strand diameter D1/D2 being greater than 1.73, each strand comprising a center of one or more center filaments and two or more layers of filaments surrounding the center, all the filaments of each layer having substantially the same diameter, a twist angle of a radially outer layer being smaller than a twist angle of a radially inner layer of the same strand, the twist angle of each layer being determined by the diameters and a lay length of the filaments, a first free space ranging from 0.0015×D to 0.0075×D being provided in at least the core strand between each pair of filaments of the radially most inner layer.
23. A steel cord having a diameter D and comprising a core strand and up to nine peripheral strands surrounding the core strand, the core strand having a diameter D1 and the peripheral strands having a diameter D2, the a ratio of the core strand diameter to the peripheral strand diameter D1/D2 being greater than 2.07, each strand comprising a center of one or more center filaments and two or more layers of filaments surrounding the center, all the filaments of each layer having substantially the same diameter, a twist angle of a radially outer layer being smaller than a twist angle of a radially inner layer of the same strand, the twist angle of each layer being determined by the diameters and a lay length of the filaments, a first free space ranging from 0.0015×D to 0.0075×D being provided in at least the core strand between each pair of filaments of the radially most inner layer.
The invention relates to a steel cord having a core strand and up to nine peripheral strands surrounding the core. Each strand comprises a center of one or more center filaments and two or more layers of filaments surrounding the center. Such a steel cord is often called a multi-strand steel cord.
Multi-strand steel cords must have a durable resistance to corrosion with a view to increasing their life span. Corrosion attack of the cords can be avoided not only by providing a suitable coating such as zinc but also by proper constructional features which allow rubber to penetrate between the individual steel filaments in the cord. Rubber penetration can be obtained by providing free spaces between the individual filaments. The situation with multi-strand steel cords is, however, not that simple as is the case with single-strand steel cords for the reinforcement of passenger or truck tires. A typical example of a multi-strand steel cord is a 7×19-construction. This steel cord has 133 individual steel filaments. Protecting every filament against corrosion attack means that every filament, even the center filaments of the core strand, should be enveloped with a rubber layer. As a consequence, relatively large spaces must be provided between neighbouring filaments. When providing large spaces between the filaments, however, the strands building up the cord and/or the cord structure itself loose their compact and uniform geometrical shape during embedment and, as a consequence, the cord no longer offers a uniform reinforcing level along its length. Moreover, it is always required that a certain given reinforcement level is achieved with the smallest possible volume of reinforcing material. This means that for a predetermined breaking load, the cross-sectional area of the steel cord should be as small as possible, which means that the outer diameter of each cord should be choosen as small as possible for a given steel section. It goes without saying that this requirement contravenes the above stated aim of providing relatively large spaces between neighbouring filaments in the cord.
It is an object of the invention to provide a multi-strand steel cord with a adequate rubber penetration coupled with a maximum reinforcement degree.
α.sub.2 =arctg[(d.sub.1 +d.sub.2)×π/LL.sub.2 ]×180/π
α.sub.3 =arctg[(d.sub.1 +d.sub.2 +d.sub.3)×π/LL.sub.3 ]×180/π
A first free space ranging from 0.0015×D to 0.0075×D, and preferably from 0.002×D to 0.007×D, is provided in at least the core strand between each pair of filaments of the radially most inner layer in order to enable the rubber to penetrate to the center filaments. Suitable absolute values of this first free space range from 0.010 mm to 0.075 mm. If the first free space has a value below the ranges mentioned, the chance for insufficient rubber penetration is great. If the first free space has a value above the ranges mentioned, too much volume will be occupied by the steel cord for a same predetermined breaking load.
A second free space being greater than the first free space, preferably ranging from 0.003×D to 0.015×D, and most preferably from 0.004×D to 0.012×D is provided in at least the core strand between each pair of filaments of the layer(s) surrounding the radially most inner layer. Suitable absolute values of this second free space range from 0.030 mm to 0.150 mm. The second free space must be greater than the first free space, since the second free space must not only allow the penetration of rubber in the layer(s) surrounding the radially most inner layer, but also the penetration of the rubber for the radially most inner layer and for the center. If the second free space has a value below the ranges mentioned, the chance for insufficient rubber penetration is great. If the second free space has a value above the ranges mentioned, too much volume will be occupied by the steel cord for a same predetermined breaking load.
The invention will now be explained in more detail with reference to the accompanying figures wherein
Referring to FIG. 1, a multi-strand steel cord 10 according to the first embodiment of the invention comprises a core strand 12 and six peripheral strands 14 which surround the core strand 12.
In this way a so-called 7×19 multi-strand steel cord is obtained.
The elongated rubberised cord of FIG. 2 can be manufactured by a vulcanisation process which is illustrated in FIG. 3. A mould comprising an under part 38 and an upper part 40 gives the element its round form. A space 41 is provided as a passage for the rubber. A space 42 should be provided between the under part 38 and the upper part 40 in order to avoid that the upper part 40 contacts the lower part 38 and to create the required pressure. Rubber is applied to the cord 10 under a pressure of at least 30 kg/cm2 at a temperature between 140° and 160° C.
A 7×19 steel cord 10 according to the invention was built as follows:
(S-lay) +6×0.75 mm (filaments 18), twist angle 16.47°+12×0.69 mm (filaments 20), twist angle 16.14°
(Z-lay) +6×0.61 mm (filaments 24), twist angle 11°+12×0.57 mm (filaments 26), twist angle 10.5°
cord: twist angle 17.88°, i.e. lay length of 66 mm, S-lay
This 7×19 steel cord according to the invention has been compared with a reference cord which does not have all features discussed above. The characteristics of the reference cord are as follows:
(S-lay) +6×0.74 mm, twist angle 17.54° +12×0.71 mm, twist angle 21.82°
(Z-lay) +6×0.63 mm, twist angle 13.9°+12×0.58 mm, twist angle 14.95°
An invention cord 10 is made as follows:
(S-lay) +6×0.26 mm (filaments 18), lay length 6 mm+12×0.24 mm (filaments 20), lay length 12 mm
(Z-lay) +6×0.21 mm (filaments 24), lay length 7.5 mm+12×0.20 mm (filaments 26), lay length 15 mm
US2567300 * Jun 30, 1949 Sep 11, 1951 American Steel & Wire Co Wire rope
US2792868 * Nov 21, 1951 May 21, 1957 Us Rubber Co Reinforced rubber article
US3240570 * Jul 18, 1963 Mar 15, 1966 United States Steel Corp Stranded wire structures and method of making the same
US3555789 * Feb 10, 1969 Jan 19, 1971 Pirelli Reinforcing metal cords
US4947636 * Feb 13, 1989 Aug 14, 1990 The Goodyear Tire & Rubber Company Metal wire cord for elastomer reinforcement
US4947638 * Dec 13, 1989 Aug 14, 1990 Sumitomo Electric Industries, Ltd. Steel cord for reinforcing rubber
BE10001626A * Title not available
JPH0221888A * Title not available
1 "Belt Cord Construction", Research Disclosure, No. 297, pp. 7-9, 29712, Emsworth, GB, Jan. 1989.
2 "Steel Cords of the 1+6+12-type", Research Disclosure, No. 343, pp. 857-859, 34370, Elmsworth, GB, Nov., 1992.
3 * Belt Cord Construction , Research Disclosure, No. 297, pp. 7 9, 29712, Emsworth, GB, Jan. 1989.
4 * Steel Cords of the 1 6 12 type , Research Disclosure, No. 343, pp. 857 859, 34370, Elmsworth, GB, Nov., 1992.
US6863103 * Nov 10, 2000 Mar 8, 2005 Bridgestone Corporation Steel cord for the reinforcement of a rubber article and tire
US7089724 * Feb 7, 2005 Aug 15, 2006 S.S. White Technologies Inc. Flexible push/pull/rotary cable
US7137483 * Jan 22, 2001 Nov 21, 2006 Hitachi, Ltd. Rope and elevator using the same
US8601782 * Nov 13, 2009 Dec 10, 2013 Bridgestone Corporation Steel cord for reinforcing rubber article and pneumatic tire
US8833414 Apr 28, 2010 Sep 16, 2014 Bridgestone Corporation Rubber article-reinforcing steel cord and pneumatic tire
US8899007 * Oct 28, 2010 Dec 2, 2014 Nv Bekaert Sa Open multi-strand cord
US8966872 * Nov 15, 2011 Mar 3, 2015 Nv Bekaert Sa Multi-strand steel cord with waved core strand
US9004128 * Jan 19, 2010 Apr 14, 2015 Bridgestone Corporation Steel cord for reinforcing rubber article and pneumatic tire
US9327555 Feb 18, 2014 May 3, 2016 Bridgestone Corporation Rubber article-reinforcing steel cord and pneumatic tire
US9428364 * Oct 21, 2004 Aug 30, 2016 Kone Corporation Elevator provided with a coated hoisting rope
US9663328 Nov 10, 2011 May 30, 2017 Otis Elevator Company Elevator system belt
US20030089551 * Jan 22, 2001 May 15, 2003 Kensuke Kato Rope and elecvator using the same
US20040029669 * Jul 10, 2003 Feb 12, 2004 Otico Reinforcing cable for a flexible endless caterpillar track
US20050060979 * Oct 21, 2004 Mar 24, 2005 Esko Aulanko Elevator provided with a coated hoisting rope
US20050178103 * Feb 7, 2005 Aug 18, 2005 S.S. White Technologies Inc. Flexible push/pull/rotary cable
US20080028740 * Oct 19, 2004 Feb 7, 2008 Kenichi Ushijima Cable Made Of High Strength Fiber Composite Material
US20110209808 * Nov 13, 2009 Sep 1, 2011 Bridgestone Corporation Steel cord for reinforcing rubber article and pneumatic tire
US20110284144 * Jan 19, 2010 Nov 24, 2011 Bridgestone Corporation Steel cord for reinforcing rubber article and pneumatic tire
US20120227885 * Oct 28, 2010 Sep 13, 2012 Nv Bekaert Sa Open multi-strand cord
US20120298403 * Jan 24, 2011 Nov 29, 2012 Johnson Douglas E Stranded thermoplastic polymer composite cable, method of making and using same
US20130261223 * Nov 15, 2011 Oct 3, 2013 Nv Bekaert Sa Multi-strand steel cord with waved core strand
EP1597183A1 † Jan 29, 2004 Nov 23, 2005 N.V. Bekaert S.A. An elevator rope
WO2013070224A1 * Nov 10, 2011 May 16, 2013 Otis Elevator Company Elevator system belt
U.S. Classification 57/212, 57/214, 57/218, 57/902
International Classification F16L11/10, D07B1/06, C08J5/06, B60C15/06, B60C9/00
Cooperative Classification D07B7/145, D07B1/16, Y10S57/902, D07B2501/2007, D07B2205/3067, D07B2501/2076, D07B1/0633, D07B1/0613, D07B2201/204, D07B2401/208, D07B2205/3071, D07B2201/2031, D07B2401/2015, D07B2201/2051, D07B2201/102, D07B2201/1084, D07B2201/1064, D07B2201/202, D07B2501/2046, D07B2201/1032, D07B2201/2011, D07B2201/2021, D07B2205/3092
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BOURGOIS, LUC;BRUYNEEL, POL;REEL/FRAME:006884/0719