This application relates to rigging, and in particular to new a master coupling link and related assembly used in the lifting of heavy objects, such as with a crane or other lifting device.
Master links or master coupling links are typically a single connection point to which a crane or hoist hook can be attached. Conveniently, master coupling links allow for slings, chains or other forms of tension elements extending to various locations on a load to be coupled together in a way that permits a wide range of adjustment for each such element. U.S. Pat. No. 4,068,467 discloses one such master link.
Master links are subject to great loads and stresses. In addition, master links are used in environments where providing for speeding rigging and de-rigging is advantageous. Conventionally available master coupling links do not provide a sufficiently robust yet flexible solution.
Described below are embodiments of a master coupling link and assembly that address the problems of the prior art.
According to some embodiments, a master coupling link assembly comprises a master coupling link and at least one sub-coupling link. The master coupling link has a first eye dimensioned to receive a lifting hook and at least two second eyes separated from said first eye. The at least one sub-coupling link is coupled to the master link at one of the at least two second eyes. The sub-coupling link is formed with the master coupling link.
The at least one sub-coupling link can comprise a primary eye and at least one secondary eye separate from the primary eye. The sub-coupling link can be coupled to the master coupling link by the intersection of the primary eye of the sub-coupling link and the first eye of the master coupling link.
The sub-coupling link can comprise two secondary eyes. The sub-coupling link can be coupled to the master coupling link without welding.
The master coupling link can be formed by casting. The sub-coupling link can be formed by casting or forging. The master coupling link and the sub-coupling link can each be formed without welds.
The at least one sub-coupling link can have tri-lobed shaped periphery. The at least one sub-coupling link can have at least a portion with an I-beam shaped cross-section. The at least one sub-coupling link can have rounded contact surfaces.
The master coupling link can have a curved surface with a first radius and the sub-coupling link can have a mating surface with a radius substantially the same as the first radius. The first eye and the at least one second eye can be dimensioned relative to each other to avoid point loading when the first eye and the second eye contact each other.
The assembly can comprise an electronically readable identification device attached to the assembly. At least the master coupling link can be made of a cast steel comprising 0.16-0.23% carbon, 0-0.80% silicon, 0-0.40% sulfur, 1.4-2.0% nickel, 0.04-0.12% vanadium, 0.70-1.00% manganese, 0-0.40% phosphorus, 0.30-0.45% chromium and 0.035-0.080% aluminum, with the balance being iron.
According to a method, a master coupling link assembly is formed by forming a master coupling link having a first eye dimensioned to receive a lifting hook and at least two second eyes separated from the first eye, and forming at least one sub-coupling link having at least one primary eye. The forming of a master coupling link and the forming of at least one sub-coupling link can take place in their recited order, opposite their recited order or approximately simultaneously. The master coupling link and the sub-coupling link are coupled together following the two forming acts.
For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatuses, and systems should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and subcombinations with one another. The methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the disclosure and does not pose a limitation on the scope of protection unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
In
Each sub-coupling link 14 is in turn coupleable to another object, such as to an upper end of one or more cable slings 16. In
The master coupling link 12 has a body 22 that defines an opening or major eye 24, such as for a hook of a crane, and at least one minor eye 26 for the one or more sub-coupling links 14. In the illustrated implementation, there are two minor eyes 26, and each receives one of the two sub-coupling links 14.
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For example, in the illustrated embodiment, two sub-coupling links 14 can be formed first, such as by casting or forging, and then inserted into a suitable mold for casting the master link 12. The forming of the master coupling link 12 can then be carried out such that it is formed having each of its two minor eyes 26 coupled to a respective one the two sub-coupling links 14. For example, a no-bake casting or other suitable molding process can be used. Other equivalent forming methods and sequences could be used. It would be possible, of course, to form the master coupling link 12 first and then form the sub-coupling links 14 in coupled condition relative to the master coupling link. Because the master coupling link 12 and the sub-coupling link 14 preferably do not have welds or other types of junctions or seams, they inherently have greater strength, integrity, and reliability. For example, the reliability of the assembly is not dependent on the quality of a weld in the master link 12 and/or in sub-coupling links 14 and/or skill of a welder.
The primary eye 64 is dimensioned to allow the sub-coupling link 14 to be engaged with one of the eyes 26 of the master coupling link 12, yet to move freely relative to the master coupling link 12 without binding. Similarly, each of the secondary eyes 66 is dimensioned to allow the sub-coupling link 14 to be engaged with another object, such as a sling 16, yet to allow free movement without binding. By comparing
Similar to the master coupling link 12, the sub-coupling link 14 is preferably formed to have an I-beam shaped cross section as shown in
Preferably, the master coupling link 12 and the sub-coupling link 14 have complimentary cross sections in at least one position. Referring to
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For example, the RFID tag 74 can be set in a recess 75 as best shown in
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Although the assembly can be formed of any suitable material, one preferred material is cast steel. In some embodiments, the cast steel comprises 0.16-0.23% carbon, up to 0.80% silicon, up to 0.40% sulfur, 1.4-2.0% nickel, 0.04-0.12% vanadium, 0.70-1.00% manganese, up to 0.40% phosphorus, 0.30-0.45% chromium, and 0.035-0.080% aluminum, with the balance being iron. Such a cast steel has good yield and tensile strengths, ductility and toughness, even at low temperatures. The components can be subjected to a heat treating process, during which the cast components are normalized, austentized and quenched, and water quenched from tempering temperature. The resulting hardness is preferably in the range of 277-293 BHN.
In view of the many possible embodiments to which the disclosed principles may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting in scope.
This is the U.S. National Stage of International Application No. PCT/US2011/037127, filed May 19, 2011, which was published in English under PCT Article 21(2), which in turn claims the benefit of U.S. Provisional Application No. 61/346,128, filed on May 19, 2010, which is incorporated herein in its entirety.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2011/037127 | 5/19/2011 | WO | 00 | 1/30/2013 |
Publishing Document | Publishing Date | Country | Kind |
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WO2011/146702 | 11/24/2011 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
1713901 | Hanson | May 1929 | A |
2703476 | Donaldson | Mar 1955 | A |
4068467 | Schreyer et al. | Jan 1978 | A |
4248469 | Knox | Feb 1981 | A |
4941698 | Klibert et al. | Jul 1990 | A |
5836631 | Coe | Nov 1998 | A |
6604769 | Herman et al. | Aug 2003 | B2 |
6948752 | Crow | Sep 2005 | B1 |
20110175383 | Segura | Jul 2011 | A1 |
Number | Date | Country |
---|---|---|
1232991 | Aug 2002 | EP |
57-196079 | Dec 1982 | JP |
62-013985 | Jan 1987 | JP |
03-023191 | Jan 1991 | JP |
Entry |
---|
International Search Report for PCT/US2011/037127 (mailed Jan. 12, 2012). |
Number | Date | Country | |
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20130134725 A1 | May 2013 | US |
Number | Date | Country | |
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61346128 | May 2010 | US |