FORMING THE SAME

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of, and priority to, U.S. Provisional Application No. 63/293,818 filed on 26 December 2021, U.S. Provisional Application No. 63/293,821 filed on 26 December 2021, and U.S. Provisional Application No. 63/294,470 filed on 29 December 2021.

Each of the aforementioned applications is incorporated by reference herein in its entirety, and each is hereby expressly made a part of this specification.

TECHNICAL FIELD

The disclosure relates generally to cord-reinforced conveyor belts, such as steel cord conveyor belts employed in mining conveyors used for efficiently transporting heavy materials (ores) over long distances, and more particularly to such conveyor belts with zero-stage splices between sections thereof and methods of forming such splices.

BACKGROUND

Steel cord reinforced conveyor belts are primarily used in heavy duty bulk solids handling applications, such as mining and general mineral transport below and above ground. Conventional steel cord conveyor belts used in heavy duty applications are typically comprised of a cured rubber as a top layer (the carry cover layer), a cured rubber as a bottom layer (the pulley cover layer), and an internal steel reinforcement layer which is situated between the top layer and the bottom layer. The internal steel reinforcement layer (the tension carcass) is disposed in a cured core rubber layer which is situated between the top layer and the bottom layer.

The prominent material used in such conveyor belts generally is a moderately flexible elastomeric or rubber-like material, and the belt is typically reinforced by a plurality of longitudinally extending steel cords or cables which are positioned within the belt and extend along the length thereof. Long steel cord conveyor belts are comprised of multiple belt sections that are joined via splices. Such splices are typically formed by stripping ends of the belt sections and intermingling the steel cords of the belt sections with each other and vulcanizing the rubber over the splices. Such splices are usually the weakest part of the overall conveyor belt because lateral tension distribution and coupling between the longitudinal steel reinforcing cords is provided by the flexible elastomeric or rubber-like material. This material is typically far weaker than the steel reinforcing cords themselves. Additional weakness in splices may arise due to adhesion limitations to the surface of the steel reinforcing cords.

Multiple step (stage) splices have been designed and are utilized in heavy duty conveyor belt construction. However, it is desirable to attain further improvements in durability, reliability, strength, and/or service life of the conveyor belt and the splices between the various sections of a conveyor belt.

It has been proposed to join the steel cord ends together via the adhesion of a brazing alloy within a metallic ferrule. Opposing individual cable ends, of which there may be more than 100 pairs, are inserted into the brazing alloy fdled ferrule. Subsequently, each of the ferrules is carefully heated such that only the brazing alloy melts without the heating process changing the material structure of the steel cords themselves. Such a process generally includes bending and/or repositioning of relatively heavy and inflexible steel cords.

Accordingly, it is desired to improve the strength and durability of the splices in steel cord reinforced conveyor belts in a cost and time effective manner to enhance the repair of existing conveyor belting, and the installation of replacement conveyor belting and for new conveyor systems (and installations thereof). Overall costs may be reduced as a result, e.g. costs associated with the conveyor belt system, the belt itself, the conveyor belt supporting frame and idlers, as well as costs associated with the pulley, motor drive, speed reducer and gearbox (by reduction in size requirements).

SUMMARY

The disclosure describes achieving splices in conveyor belts that exhibit improved dynamic strength and durability by bonding cords via specific cost and time effective methods, e.g. by eliminating the need for multiple step splices. Improvements in the service life of conveyor belts and conveyor belt reliability may also be achieved. Since splices between various sections of conveyor belts are typically the weakest area of the conveyor belt, such improvements in splice strength may allow for belts having lower ST ratings to be utilized to meet needed performance requirements. For instance, splices in commercial conveyor belts currently have a dynamic splice efficiency which is typically within the range of 50% to about 55%. Multi-step splice layouts may be relatively time consuming and costly to manufacture and construct in the field. Conveyor belts which are manufactured utilizing splices disclosed herein may exhibit a dynamic splice efficiency of 70%, 80%, 100% or even greater (i.e. stronger than the parent belt) and may be constructed faster and cheaper. For example, in some cases it is found that the belt safety factor may be reduced from the conventional 6.7: 1 to that 5: 1 or lower.

In some aspects, there is disclosed a conveyor belt which is reinforced with steel cables, and which includes a first section and a second section which are joined together with a splice. In some embodiments, the splice bonds a first set of steel cables from the first section of the conveyor belt to a second set of steel cables from the second section of the conveyor belt with an elastomeric adhesive, and the first set of steel cables and the second set of steel cables are contained within a flexible circumferential sheath at the point of where the first set of steel cables are bonded to the second set of steel cables. In some embodiments, the splice bonds a first set of steel cables from the first section of the conveyor belt to a second set of steel cables from the second section of the conveyor belt with an elastomeric adhesive, and wherein the first set of steel cables and the second set of steel cables are longitudinally and vertically aligned with semi-circumferential inserts at the point of where the first set of steel cables are bonded to the second set of steel cables. In some embodiments, the splice joins a first set of steel cables from the first section of the conveyor belt to a second set of steel cables from the second section of the conveyor belt with a formed-in-place braze alloy casting.

In an aspect, the disclosure describes a method of forming a resiliently deformable zero-stage splice of a cord-reinforced conveyor belt by joining a first cord segment to a second cord segment. The method also includes, while the first and second cord segments are disposed end-to-end and spaced apart from each other to define a gap, confining elastomeric adhesive in the gap and around the first and second cord segments using a pliable sheath for the elastomeric adhesive to allow at least partial curing of the elastomeric adhesive to form sheathed adhesive that adhesively couples the first and second cord segments to each other; and after at least partial curing of the elastomeric adhesive, forming a matrix comprising a reinforcement carcass around the sheathed adhesive, and carry and pulley cover layers over the reinforcement carcass and the sheathed adhesive, so as to form the zero-stage splice.

In an aspect, the disclosure describes a cord-reinforced conveyor belt. The cord - reinforced conveyor belt also includes a first cord segment; a second cord segment disposed end-to-end adjacent to the first cord segment and spaced apart from the first cord segment to define a gap between the first and second cord segments; elastomeric adhesive disposed in the gap and around the first and second cord segments; a pliable sheath confining the elastomeric adhesive during curing so as to form sheathed adhesive that is resiliently deformable and adhesively couples the first and second cord segments to each other; and a matrix including a reinforcement carcass around the sheathed adhesive, and carry and pulley cover layers over the reinforcement carcass and the sheathed adhesive so as to define a zero-stage splice.

In an aspect, the disclosure describes a kit for forming a resiliently deformable zero-stage splice of a cord-reinforced conveyor belt by joining a first cord segment to a second cord segment disposed end-to-end and spaced apart from each other to define a gap. The kit also includes elastomeric adhesive; and a pliable sheath for the elastomeric adhesive for confining the elastomeric adhesive in the gap and around the first and second cord segments to allow at least partial curing of the elastomeric adhesive to form resiliently deformable sheathed adhesive that adhesively couples the first and second cord segments to each other, the zero-stage splice being formed by, after at least partial curing of the elastomeric adhesive, forming a matrix comprising a reinforcement carcass around the sheathed adhesive, and carry and pulley cover layers over the reinforcement carcass and the sheathed adhesive.

In an aspect, the disclosure describes a method of forming a zero-stage splice of cord-reinforced conveyor belt by joining a first cord segment to a second cord segment. The method also includes disposing in a receptacle the first and second cord segments end-to-end and spaced apart from each other to define a gap, the receptacle being elongated and open along the first and second cord segments; disposing brazing paste into the receptacle to fill the gap and to at least partially surround the first and second cord segments, disposing a cap over the first and second cord segments to close the receptacle to form a crucible surrounding the brazing paste, and heating the crucible to heat the brazing paste for forming a joint between the first cord segment and the second cord segment.

Embodiments can include combinations of the above features. Further details of these and other aspects of the subject matter of this application will be apparent from the detailed description included below and the drawings.

DESCRIPTION OF THE DRAWINGS

Reference is now made to the accompanying drawings, in which:

FIG. 1A is partial perspective view of a two disjointed sections of cord-reinforced conveyor belt, in accordance with an embodiment;

FIG. IB is a longitudinal cross-sectional view of two cord segments stripped of surrounding matrix to allow joining to form a zero-stage splice, in accordance with an embodiment;

FIG. 2A is a lateral cross-sectional view of two cord segments surrounded by adhesive and receiving a sheath thereon, in accordance with an embodiment;

FIG. 2B is a lateral cross-sectional view of FIG. 2A showing the sheath being wrapped around the adhesive and the two cord segments, in accordance with an embodiment;

FIG. 2C is a longitudinal cross-sectional view of a zero-stage splice formed by completing the joint shown in FIG. 2B, in accordance with an embodiment;

FIG. 3 is a perspective view of a pliable sheath, in accordance with another embodiment;

FIG. 4 is a lateral cross-sectional view of a joint between the cord segments formed using the pliable sheath of FIG. 3, in accordance with an embodiment;

FIG. 5 is an enlarged view of region in FIG. 3, in accordance with an embodiment;

FIG. 6 is a top cross-sectional view of a zero-stage splice between cord segment, in accordance with an embodiment;

FIG. 7 is a flow chart of an exemplary method of forming a resiliently deformable zero-stage splice of a cord-reinforced conveyor belt by joining a first cord segment to a second cord segment;

FIG. 8 is a lateral cross-sectional of conveyor belt with a brazing joint, in accordance with an embodiment;

FIG. 9A is a cross-sectional view of an example step during formation of the brazing joint, involving receiving the cord segments and brazing paste in a receptacle;

FIG. 9B is a cross-sectional view of another example step during formation of the brazing joint, involving closing the receptacle using a cap to form a crucible; FIG. 9C is a cross-sectional view of an example step during formation of the brazing joint, involving heating the crucible using electromagnetic induction; and

FIG. 10 is a flow chart of an exemplary method of forming a zero-stage splice of cord-reinforced conveyor belt by joining a first cord segment to a second cord segment.

DETAILED DESCRIPTION

The following disclosure relates to cord-reinforced conveyor belts having improved splices between various sections of the conveyor belts, and methods of forming the same. In such conveyor belts the steel reinforcing cords are bonded together within zero-step or zero-stage splices.

In various embodiments, methods of affixing multiple cords, e.g. steel cables, together described here may allow for a zero-stage splice without compromising, or reducing a compromise of, the strength or durability of the splice. In some embodiments, such splices may offer improved strength and durability as compared to existing technologies.

In various embodiments, splices disclosed herein may exhibit a dynamic efficiency in the range of 50-70%, 80-90%, or 100% or more of the reinforcing steel cable carcass strength and durability, may have a relatively small size by having no steps or stages (e.g. in terms of the longitudinal length thereof), and/or may have low overall material component cost.

In various embodiments, methods for forming such splices may lead to decreased steel cable preparation time, decreased splice layout time, decreased splice construction time, decreased overall splice preparation time, a reduction in the size of the vulcanizing press needed for curing (the splice), and a reduction in the downtime of the conveyor belt to the user of the conveyor belt.

Aspects of various embodiments are described in relation to the figures.

FIG. 1A is partial perspective view of a two disjointed sections 12A, 12B of cord-reinforced conveyor belt 10, in accordance with an embodiment.

The conveyor belt 10 comprises separate sections 12A, 12B elongated along a longitudinal direction 14 and spliced to each other along a lateral plane 16. The sections 12A, 12B in FIG. 1A are shown prior to a splice being formed between them.

The conveyor belt 10 is reinforced by a plurality of cords 18. In some embodiments, a primary strength of the conveyor belt 10 is provided by the cords. The plurality of cords 18 may be substantially coplanar, e.g. these may be a plurality of coplanar steel reinforcing cables. In various embodiments, the cords 18 may be steel cords.

The cords 18 are surrounded by a reinforcement carcass 20, i.e. the reinforcement carcass 20 may contain the cords 18. A carry cover layer 22 and a pulley cover layer 24 extend over the cords 18 and may define exterior-most layers of the conveyor belt 10. It is understood that there may be additional layers in the conveyor belt 10.

The cords 18 may each have a diameter 17 such that the reinforcement carcass 20 surrounds the cords 18. Each of the cords 18 may be spaced apart from its respective adjacent cords by distance 19. The distance 19 may be less than the diameter 17.

FIG. IB is a longitudinal cross-sectional view of two cord segments 18A, 18B stripped of surrounding matrix to allow joining to form a zero-stage splice, in accordance with an embodiment.

The cross-section is parallel to the longitudinal direction 14 and a (lateral) vertical direction 26.

The cord segments 18A, 18B are disposed end-to-end and adjacent to each other. The (ends of the) cord segments 18A, 18B are spaced apart from each other to define a gap 28 therebetween. In various embodiments, the gap may be between or on the order of 5 to 50 mm.

The matrix comprises the reinforcement carcass 20, the carry cover layer 22, and the pulley cover layer 24.

The cord segments 18A, 18B are shown as monolithic sections for clarity. However, it is understood that the cord segments 18A, 18B may comprise a plurality of strands and/or a plurality of cord segments formed of strands. As referred to herein, the cord segments 18A, 18B may refer to portions of cords exposed for forming a splice.

In methods of joining or splicing cords (e.g. steel cables) described herein, adjoining sections 12A, 12B (segments) of the conveyor belt 10 are bonded together in the splices between two or more sections of the belt. The methods described herein may be employed in connecting steel cables which are comprised of various types of steel and with various types of cable construction. In some embodiments, the steel cables may be galvanized or may be brass plated.

In various embodiments, it is understood that aspects described herein may be applicable to a variety of cable or cord diameters and cable or cord pitches (i.e. the lateral distance between adjacent cords in the conveyor belt 10). FIG. 2A is a lateral cross-sectional view of the two cord segments 18A, 18B surrounded by adhesive and receiving a sheath thereon, in accordance with an embodiment.

FIG. 2B is a lateral cross-sectional view of FIG. 2A showing the sheath being wrapped around the adhesive and the two cord segments, in accordance with an embodiment.

Referring to FIGS. 2A-2B, the lateral cross-section shown parallel to the lateral plane 16, i.e. parallel to the (lateral) vertical direction 26 and a (lateral) horizontal direction 27.

FIG. 2C is a longitudinal cross-sectional view of a zero-stage splice 34 formed by completing the joint shown in FIG. 2B, in accordance with an embodiment.

Elastomeric adhesive 30 is disposed in the gap 28 and around the cord segments 18A, 18B. For example, the elastomeric adhesive 30 may be a polymeric or a hybrid polymer adhesive. For example, the elastomeric adhesive 30 may be composed of MS Polymer™ (comprising polymers with silane terminal functionality) or other polymer combining properties of polyurethane-based adhesive/sealant and silicone-based adhesive/sealant. The elastomeric adhesive 30 may be referred to as such due to it forming an elastomer (retaining elasticity) upon curing, e.g. in some embodiments the elastomeric adhesive 30 may be a non-elastomer in an uncured state. In various embodiments, the elastomeric adhesive 30 may be curable by application of pressure, and/or exposure to air, moisture, and/or heat, e.g. over a period of time. For example, in some embodiments, a full curing time may be between 24 and 48 hours.

In some embodiments, the elastomeric adhesive 30 may have a minimum thickness to achieve a desired bond strength and/or elastic properties, e.g. in some embodiments the thickness may be at least 1 mm. Minimum thickness here may refer to a smallest distance between separate bonding surfaces that is bridged by the elastomeric adhesive 30 to bond the bonding surfaces.

A pliable sheath 32 confines the elastomeric adhesive during curing so as to form sheathed adhesive, as seen in FIG. 2C. The sheathed adhesive is resiliently deformable (when cured) and adhesively couples the cord segments to each other via the pliable sheath 32. When the elastomeric adhesive 30 is fully cured, the sheathed adhesive may provide a strong bond between the cord segments 18A, 18B and may be resiliently deformable (or flexible) so as to allow joint between the cord segments 18A, 18B to undergo lateral stress and/or shear, e.g. while being drawn over a pulley. In splicing the cord segments 18A, 18B together the elastomeric adhesive 30 may be applied over a sufficient distance in the longitudinal direction 14 from respective ends of the cord segments 18A, 18B facing the gap 28. Then the pliable sheath 32 in the form of a U-shaped flexible sheath of a length equal to about the longitudinal distance spanned by cord segments 18A, 18B may be placed over the aforementioned ends prior to full curing of the elastomeric adhesive 30 and/or prior to completion of less than half of a curing cycle of the elastomeric adhesive 30.

In various embodiments, the elastomeric adhesive 30 may be elastic in an uncured state. In some embodiments, the elastomeric adhesive 30 may be a one-component adhesive and/or act as a sealant. In various embodiments, the elastomeric adhesive 30 may have an initial tack of more than 200 kg/m ² (full surface bonding). In various embodiments, a representative elastomeric adhesive may be Soudaseal Supertack™ or the like. Such an elastomeric adhesive may exhibit the requisite tensile and shear strength, along with desired modulus of elasticity and desired tack interval. In various embodiments, the adhesive may allow elastic bonding of objects and/or elastic structural bonding. Properties of an example adhesive are tabulated in Table 1.

TABLE 1

PROPERTIES DESCRIPTION

Basis MS Polymer™

Consistency Stable paste

Curing system Moisture curing

Skin formation at 23°C and 50% R.H. Ca. 5 min

Curing speed at 23°C and 50% R.H. 3 mm/24h

Hardness in fully cured state 65 ± 5 Shore A

Density 1,55 g/ml

Maximum allowed distortion ± 20 %

Max. tension (ISO 37) in fully cured state 2,91 N/mm ²

Elasticity modulus 100% (ISO 37) in fully cured state 2,18 N/mm ²

Temperature resistance in fully cured state -40 °C 90 °C

Application temperature 5 °C — > 35 °C Depending on the ST rating of the conveyor belt, the longitudinal distance d where elastomeric adhesive 30 is applied may be <7=ST/40 mm. This formula is derived from the elastomeric adhesive fdl factor to the cable surfaces, tensile strength, and shear strength. For example, in the case of an ST6800 conveyor belt (ST rating of 6800), the longitudinal distance d may be about 170 mm. In the case of a cord (or cable) of diameter about 10 mm, an appropriate elastomeric adhesive 30 applied and cured along such a distance may cause a 100% tension load transfer by the elastomeric adhesive 30 from the cable to the pliable sheath 32 (the circumferential flexible sheath described previously). The pliable sheath 32 may provide the coupling between the cord segments 18A, 18B via the elastomeric adhesive 30.

It is understood that, in various embodiments, the cord segments 18A, 18B may be prepared prior to application of the elastomeric adhesive 30. For example, the cord segments 18A, 18B may be cleaned and/or treated with a cleaner and/or an adhesion promoter or surface activator used for activating surfaces to improve adhesion. In some cases, the surface activator may be formed of a solvent mixture with additives. In various embodiments, any porous surfaces may be primed with an epoxy primer such as Primer 150™.

In the case of a representative ST6800 conveyor belt, with an inter-cable (inter-cord) spacing of 7 mm, and with a pliable sheath 32 having a thickness of 2 mm, the parallel sheaths may intrude into the cable interstitial space by 2 x 2 mm. It will be realized that for smaller ST ratings and smaller diameter cords, the flexible sheath thickness may be reduced.

A portion 31 of the pliable sheath 32 may be elongated longitudinally (in the longitudinal direction 14) along the cord segments 18A, 18B so as to cover the elastomeric adhesive 30. The portion 31 may be received on to a first side of the gap 28 so as to confine the elastomeric adhesive 30. The pliable sheath 32 may be positioned above the cord segments 18A, 18B as it is received thereupon.

A second side of the gap 28 may be opposite to the first side of the gap 28. For example, the first side may be a side of the gap proximal to the carry cover layer 22 and the second side may be a side of the gap proximal to the pulley cover layer 24, or the first side may be a side of the gap proximal to the pulley cover layer 24 and the second side may be a side of the gap proximal to the carry cover layer 22.

The portion 31 may extend arcuately laterally (in the horizontal direction 27) over the cord segments 18A, 18B so as to complementarity engage with cord segments 18A, 18B. For example, such a portion 31 may be semi-cylindrical, partially semi-cylindrical, and/or in the form of arc of a circle extruded along the longitudinal direction 14. For example, a U-shaped flexible sheath may have a diametric width to accommodate the diameters of cable, i.e. the cord segments 18A, 18B. The pliable sheath 32 and the two respective ends of the cords segments 18A, 18B may be bonded together by the elastomeric adhesive 30 in the splice.

In various embodiments, the pliable sheath 32 may incorporate suitable form bands at its extreme or terminal ends in order to hold its shape during transport and handling. In various embodiments, these can be of wire, elastomer, plastic or the like and are not shown in the drawings for clarity.

In some embodiments, the pliable sheath 32 may be foldable and (at least partially) wrapped around the elastomeric adhesive 30. The pliable sheath 32 may be folded around a second side of the gap 28 opposite to the first side of gap 28 to partially or fully wrap the pliable sheath 32 around the elastomeric adhesive 30.

In various embodiments, the pliable sheath 32 may be wrapped, e.g. partially or circumferentially, around the elastomeric adhesive 30 by drawing of opposed ends of the pliable sheath 32 towards each other. The opposed ends may be spaced apart from each other when the pliable sheath 32 is so wrapped so to form a slight gap without an overlap. In some embodiments, an overlap may be allowed with no gap.

The elastomeric adhesive 30 may be in its tack curing interval while the pliable sheath 32 is being circumferentially wrapped around the cable ends over the previously described longitudinal distances over which the elastomeric adhesive 30 is applied. In various embodiments, this may ensure that the flexible sheath 32 stays in place while full or primary adhesive curing process takes place. For example, primary adhesive curing may refer to such curing as may be sufficient to complete assembly of the splice into a state wherein it may be allowed to rest or be prevented from supporting loading so as to allow subsequent curing to achieve required splice strength and/or integrity.

In various embodiments, the pliable sheath 32 may be wire mesh, e.g. it may be composed of metal strands intertwined with each other. In some embodiments, the pliable sheath 32 may comprise carbon steel or stainless steel wires, strands or the like. In some embodiments, the pliable sheath 32 may be comprised of carbon fiber or like strands exhibiting suitable tensile strength and flexibility.

The reinforcement carcass may be formed between the sheathed adhesive and one or more adjacent cord segments to couple the adjacent cord segments to the cord segments 18A, 18B via the sheathed adhesive. The one or more adjacent cord segments may be laterally adjacent to the cord segments 18A, 18B in the horizontal direction. In various embodiments, adjacent cord segments of the one or more adjacent cord segments may be spaced apart from the sheathed adhesive by less than a diameter of the adjacent cord segment.

In various embodiments, as shown in FIG. 2C, the elastomeric adhesive 30 may be excreted out of opposed ends of the pliable sheath 32 that are longitudinally spaced apart along the cord segments 18A, 18B. This may cause adhering of the reinforcement carcass 20 to the cord segments 18A, 18B. As shown in FIG. 2C, the elastomeric adhesive 30 may be sandwiched between the pliable sheath 32 and the cord segments 18A, 18B.

A matrix 36 is formed over the sheathed adhesive 38. This includes forming a reinforcement carcass 20 around the sheathed adhesive 38, forming a carry cover layer 22 over the reinforcement carcass and the sheathed adhesive, and forming a pulley cover layer 24 over the reinforcement carcass and the sheathed adhesive 38.

Such a matrix 36 may be formed after the elastomeric adhesive 30 has fully cured. In such a state, the cables may be (circumferentially) bonded to the pliable sheath 32 and may therefore bond cable ends together. The splice may be finished using methods and materials for affixing the elastomeric layers of the conveyor belt 10 together at the point of the splice. For instance, the carry cover layer 22 and the pulley cover layers 24 of the conveyor belt 10 may be bonded to the reinforcing layer (the reinforcement carcass 20) utilizing splicing procedures.

FIG. 3 is a perspective view of a pliable sheath 132, in accordance with another embodiment.

The pliable sheath 132 comprises separate components, insert 40A and insert 40B, that together may provide sheathing to the elastomeric adhesive 30 without fully sheathing ends of the cord segments 18A, 18B.

Insert 40A may be a first type of insert suitable for confinement of elastomeric adhesive to form a joint of a splice. Insert 40B may be a second type of insert suitable for confinement of elastomeric adhesive to form two separate, adjacent joints of the splice. In various embodiments, two inserts of the first type may be used to form a joint, or two inserts of the second type may be used to form a joint.

FIG. 4 is a lateral cross-sectional view of a joint between the cord segments 18A, 18B formed using the pliable sheath 132 of FIG. 3, in accordance with an embodiment.

FIG. 5 is an enlarged view of region 5 in FIG. 3, in accordance with an embodiment. In the embodiment of FIG. 4, the inserts 40A, 40B confine the elastomeric adhesive 30 at respective first and second sides of the gap 28. While the inserts 40A, 40B may be separate and (laterally) spaced apart from each other around the cord segments 18A, 18B, they together form the pliable sheath 132 for sheathing the elastomeric adhesive 30. In various embodiments, the elastomeric adhesive 30 is configured to form an elastomer adhesively bonded to the pliable sheath 132 and the cord segments 18A, 18B.

The inserts 40A, 40B may be elongated longitudinally along the cord segments 18A, 18B so as to provide a sufficient longitudinal length for the elastomeric adhesive 30.

In various embodiments, each of the inserts 40A, 40B is dimensioned (i.e. length 46) to extend no more than about the diameter 17 of the cord segments 18A, 18B between the carry cover layer 22 and the pulley cover layer 24, or slightly larger, so as to avoid generating bump(s) or protrusion(s) in the conveyor belt 10 signifying splice location(s).

When assembled as shown in FIG. 4, the inserts 40A, 40B arcuately extend laterally over the cord segments 18A, 18B opposite to each other and towards each other around the elastomeric adhesive 30. Each of the inserts 40A, 40B may define respective ends 42A, 42B facing the cord segments 18A, 18B and opposite to each other. The ends 42A, 42B may be arcuately extended laterally over the cord segments 18A, 18B. For example, the ends 42A, 42B may be semi-cylindrical or extruded with a convex cross-section facing the cord segments 18A, 18B.

The insert 40A may define an end 44A opposite to the end 42A. The end 44A may define an elongated face spaced apart from the cord segments 18A, 18B that is suitable for handling by a user. For example, the elongated face (end 44A) may be substantially flat and may extend the longitudinal length of the insert 40A.

The insert 40B may define an end 44B opposite to the end 42B. As shown in FIG. 4, the end 44B may be arcuately extended laterally so as to face another cord segment(s) laterally adjacent to the cord segments 18A, 18B. The end 44B may then confine elastomeric adhesive 30 around the adjacent cord segment(s) so as to simultaneously form two separate joints. Advantageously, this may reduce time required for assembly.

In various embodiments, the ends 42B, 44B are convex or semi-cylindrical facing away from each other, i.e. with their apex (intermediate) position defining a smallest separation between the ends 42B, 44B rather than a largest separation therebetween. A flexible connector 48 may connect ends 42B, 44B so as to allow a lateral size of the insert 40B to be varied by compression of the connector 48 between the ends 42B, 44B. This may facilitate positioning of the insert 40B between cords and gaps therebetween, e.g. the insert 40B may be made smaller, positioned in place, and then released to engage with the elastomeric adhesive 30. In various embodiments, the connector 48 may be partially or completely composed of foam or other deformable material.

In various embodiments, the inserts 40A, 40B may be configured such that the sheathed adhesive 38 is embedded within the reinforcement carcass 20. Such embedding may ensure that the thicknesses of the carry cover layer 22 and the pulley cover layer 24 are substantially uniform over and around the zero-stage splice, e.g. to avoid protrusions and bumps as mentioned earlier. In various embodiments, the pliable sheath 132 may positioned in the matrix 36 away from surfaces of the cord segments 18A, 18B facing the carry cover layer 22 and the pulley cover layer 24 such that the pliable sheath 132 is prevented from intruding thereinto. In various embodiments, the elastomeric adhesive 30 may be positioned around the cord segments 18A, 18B such that confining of the elastomeric adhesive 30 by the pliable sheath 132 avoids intrusion thereof into the carry cover layer 22 and the pulley cover layer 24 when the matrix 36 is formed. For example, surfaces of the cord segments 18A, 18B facing, or closest to, the carry cover layer 22 and the pulley cover layer 24 may be substantially free of the elastomeric adhesive 30.

Once the sheathed adhesive 38 is assembled, the elastomeric adhesive 30 is cured. In some embodiments, the elastomeric adhesive 30 is cured by heat applied to the matrix 36 to form the zero-stage splice. For example, the elastomeric adhesive 30 may be cured by heating the material composing the reinforcement carcass 20 around the elastomeric adhesive 30 to simultaneously form the reinforcement carcass 20 and cause heat-curing of the elastomeric adhesive 30. For example, high temperature curing may be achieved efficiently. In some embodiments, partial or full curing of the elastomeric adhesive 30 may take place without heat.

In some embodiments, the splice may be finished (immediately or soon) after the elastomeric adhesive 30 has tack cured and is thereby lightly bonding the steel cables to the inserts 40A, 40B (< 10% of cured strength) and is therefore bonding the cable ends lightly together. For example, the insertion of small amounts of uncured core rubber into remaining cable interstices, the addition of new uncured top and bottom cover rubber, and other steps may be carried out. The carry cover layer 22 and the pulley cover layer 24 may be bonded to the reinforcement carcass 20 by procedures such as hot vulcanization, which is used to cure (crosslink) the uncured rubber in the splice construct, and simultaneously cure the elastomeric adhesive used. In various embodiments, at the vulcanization temperatures used, the elastomeric adhesive may cure fully at twice the rate of rubber.

In various embodiments, the elastomeric adhesive 30 may be a commercially available super adhesive exhibiting the requisite tensile and shear strength along with desired modulus of elasticity and desired tack interval, along with the ability to handle typical splice vulcanization temperatures. As such, the elastomeric adhesive 30 may be heat cured and/or chemically cured. As described above, heat curing may be achieved by vulcanization of the matrix 36. As opposed to cured rubber having an adhesion strength range of 2-3 N/mm ² , the adhesion strength of super adhesives may range from 20 to 35 N/mm ² or more. Depending on the tension rating of the steel cable in the conveyor belt, the longitudinal distances over which adhesive is applied, and over which the pliable sheath 132 (at least partially) encircles the cord segments 18A, 18B, may be about d = ST/x. This formula is derived from the elastomeric adhesive fill factor to the cable surfaces and its tensile and shear strength. In the case of an ST5400 belt, x=25 and the longitudinal distances are 216 mm. In the case of an 11 mm diameter cable, this may provide a 100% tension load transfer by the elastomeric adhesive from the cables to the inserts 40A, 40B.

In various embodiments, the inserts 40A, 40B may be semi-rigid or pliability. Semi-rigidity or pliability may refer to a structure that may retain its shape but may be deformable upon application of force. In various embodiments, the inserts 40A, 40B may be made of a mesh as shown in FIG. 5. For example, the mesh may be a metal mesh. The inserts 40A, 40B may be composed of strands of metal that are knitted or woven (intertwined). In some embodiments, the metal mesh may be embedded in elastomer to provide flexibility. In some embodiments, the metal mesh may be embedded in epoxy to provide flexibility. In various embodiments, the inserts 40A, 40B may be comprised of stainless steel or synthetic strands such as aramid or like strands exhibiting suitable tensile strength and flexibility. In various embodiments, the inserts 40A, 40B may be comprised of a multitude of carbon steel wires or strands that are interwoven to distribute tensile forces much as is done in conventional wire ropes.

In various embodiments, the inserts 40A, 40B may be composed of a material with greater tensile strength than a material forming the cord segments 18A, 18B. For example, in circumstances where the conveyor belt 10 employs wire rope comprised of improved plow steel (IPS), the inserts 40A, 40B may be constructed of extra improved plow steel (EIPS) or extra extra improved plow steel (EEIPS). This ensures that the tensile strength of the inserts 40A, 40B is at least equal to, if not greater than the steel cords themselves in the inter-cable volume available to an insert for joining.

It is understood that the inserts 40A, 40B may incorporate suitable form bands along their length or extreme (terminal) ends in order to allow them to hold shape during transport and handling. Such features may be made of wire, elastomer, plastic or the like and are not shown for clarity.

FIG. 6 is a top cross-sectional view of a zero-stage splice between cord segments 18A, 18B, in accordance with an embodiment.

In FIG. 6, a pliable sheath may be formed using inserts 40A, 40B that may be flexible, semi- circumferential, and of suitable length and diametric width

In splicing the steel cables together, elastomeric adhesive may be applied over the cable facing surface of the inserts 40A, 40B. These inserts 40A, 40B may be inserted such that they are vertically and longitudinally aligned with the ends of the cord segments 18A, 18B, and which may then span or overlap a sufficient longitudinal distance of the respective cable ends. The insertion may be carried out during the tack curing interval for said elastomeric adhesive.

FIG. 7 is a flow chart of an exemplary method 700 of forming a resiliently deformable zero-stage splice of a cord-reinforced conveyor belt by joining a first cord segment to a second cord segment.

Step 702 of the method 700 includes, while the first and second cord segments are disposed end- to-end and spaced apart from each other to define a gap, confining elastomeric adhesive in the gap and around the first and second cord segments using a pliable sheath for the elastomeric adhesive to allow at least partial curing of the elastomeric adhesive to form sheathed adhesive that adhesively couples the first and second cord segments to each other. Confining the elastomeric adhesive may include supporting the elastomeric adhesive.

Step 704 of the method 700 includes, after at least partial curing of the elastomeric adhesive, forming a matrix comprising a reinforcement carcass around the sheathed adhesive, and carry and pulley cover layers over the reinforcement carcass and the sheathed adhesive, so as to form the zero-stage splice.

In some embodiments of the method 700, the elastomeric adhesive is configured to form, upon curing, an elastomer adhesively bonded to the pliable sheath and the first and second cord segments. In some embodiments of the method 700, the elastomeric adhesive is a polymeric adhesive.

In some embodiments of the method 700, at least partial curing of the elastomeric adhesive includes maintaining the elastomeric adhesive at least partially uncured until the matrix is being formed.

In some embodiments of the method 700, the matrix includes a material, and forming the matrix includes heating the material around the elastomeric adhesive to at least partially simultaneously form the matrix and cause heat-curing of the elastomeric adhesive.

In some embodiments of the method 700, the sheathed adhesive is embedded within the reinforcement carcass such that thicknesses of the carry and pulley cover layers are substantially uniform over and around the zero-stage splice.

In some embodiments of the method 700, the elastomeric adhesive is positioned around the first and second cord segments such that confining of the elastomeric adhesive by the pliable sheath avoids intrusion of the pliable sheath into the carry and pulley cover layers when the matrix is formed.

In some embodiments of the method 700, surfaces of the first and second cord segments facing the carry and pulley cover layers are substantially free of elastomeric adhesive.

In some embodiments of the method 700, the pliable sheath is positioned away from surfaces of the first and second cord segments facing the carry and pulley cover layers such that the pliable sheath is prevented from intruding into the carry and pulley cover layers when the matrix is formed.

In some embodiments of the method 700, the pliable sheath is formed of a first insert and a second insert separate and spaced apart from the first insert.

In some embodiments of the method 700, confining the elastomeric adhesive in the gap and around the first and second cord segments using the pliable sheath includes confining the elastomeric adhesive at a first side of the gap using the first insert.

In some embodiments of the method 700, confining the elastomeric adhesive in the gap and around the first and second cord segments using the pliable sheath includes confining the elastomeric adhesive at a second side of the gap opposite to the first side using the second insert, the first and second sides facing away from the carry and pulley cover layers. In some embodiments of the method 700, the first and second inserts are elongated longitudinally along the first and second cord segments and laterally spaced apart from each other while confining the elastomeric adhesive.

In some embodiments of the method 700, each of the first and second inserts are dimensioned to extend no more than about a diameter of the first cord segment and a diameter of the second cord segment between the carry and pulley cover layers.

In some embodiments of the method 700, the first and second inserts are semi-rigid and arcuately extend laterally over the first and second cord segments opposite to each other and towards each other around the elastomeric adhesive.

In some embodiments of the method 700, each of the first and second inserts defines a corresponding semi-cylindrical end facing the first and second cord segments.

In some embodiments of the method 700, the first insert defines an elongated face spaced apart from the first and second cord segments so as to be suitable for handling.

In some embodiments of the method 700, the first and second inserts each include a metal mesh.

In some embodiments of the method 700, the metal mesh is embedded in elastomer. In some embodiments, the metal mesh may be embedded in epoxy.

In some embodiments of the method 700, the first insert defines a first end and a second end opposite to the first end, the first end arcuately extending laterally over the first and second cord segments. In some embodiments of the method 700, the second end arcuately extends laterally so as to face a third cord segment laterally adjacent to the first and second cord segments to confine elastomeric adhesive around the third cord segment.

In some embodiments of the method 700, the first insert is elongated so as to be suitable to be elongated longitudinally along the first and second cord segments.

In some embodiments of the method 700, the first insert is dimensioned to extend no more than about a diameter of the first cord segment and a diameter of the second cord segment between the carry and pulley cover layers.

In some embodiments of the method 700, each of the first and second ends are semi-cylindrical facing away from each other. In some embodiments of the method 700, the first insert comprises a flexible connector between the first and second ends so as to allow the first insert to be compressed between the first and second ends to facilitate positioning of the first insert between the third cord segment and the first and second cord segments.

In some embodiments of the method 700, the flexible connector is composed of foam.

In some embodiments of the method 700, the pliable sheath is foldable so as to be partially wrapped around the elastomeric adhesive.

In some embodiments of the method 700, confining the elastomeric adhesive in the gap and around the first and second cord segments using the pliable sheath includes receiving a portion of the pliable sheath on to a first side of the gap. In some embodiments of the method 700, the portion is elongated longitudinally along the first and second cord segments and arcuately extends laterally over the first and second cord segments.

In some embodiments of the method 700, confining the elastomeric adhesive in the gap and around the first and second cord segments using the pliable sheath includes folding the pliable sheath around a second side of the gap opposite to the first side to partially wrap the pliable sheath around the elastomeric adhesive.

In some embodiments of the method 700, folding the pliable sheath around the second side of the gap includes drawing opposed ends of the sheath towards each other to wrap the pliable sheath around the elastomeric adhesive while keeping the opposed ends spaced apart from each other.

In some embodiments of the method 700, the first and second sides of the gap face the carry and pulley cover layers.

In some embodiments of the method 700, the pliable sheath is composed of metal strands intertwined with each other.

In some embodiments of the method 700, forming the reinforcement carcass around the sheathed adhesive includes forming the reinforcement carcass between the sheathed adhesive and one or more adjacent cord segments to couple the adjacent cord segments to the first and second cord segments via the sheathed adhesive.

In some embodiments of the method 700, the one or more adjacent cord segments are laterally adjacent to the first and second cord segments. In some embodiments of the method 700, adjacent cord segment of the one or more adjacent cord segments is spaced apart from the sheathed adhesive by less than a diameter of the adjacent cord segment.

In some embodiments of the method 700, the elastomeric adhesive is excreted out of opposed ends of the pliable sheath that are longitudinally spaced apart along the first and second cord segments to cause the elastomeric adhesive to adhere the reinforcement carcass to the first and second cord segments.

FIG. 8 is a lateral cross-sectional of conveyor belt with a brazing joint 60, in accordance with an embodiment.

In forming this joint between cord segments 18A, 18B, a lower semi cylindrical receptacle (a hemispherical shaped cradle or other partial envelope of suitable length) is brought up underneath the pair of opposing cord segments 18A, 18B to a position where the receptacle is not touching the ends of the cord segments 18A, 18B facing each other, but provides an annular (semi cylindrical or hemispherical) gap of suitable size between the cord segments 18A, 18B and the receptacle. This receptacle longitudinally overlaps each of the cord segments 18A, 18B for a suitable distance and can also provide end spacers or seals that contact the cords. Thereafter, a braze alloy paste (e.g. containing filler metal and flux) may be applied and filled into a gap between the cord segments 18A, 18B, as well as onto each of the cord segments 18A, 18B (the annular gap described above) for a suitable longitudinal distance. In various embodiments, the brazing paste may partially fill in and be held by the receptacle. Thereafter, an upper semicylindrical cap (a hemispherical shaped cap of suitable length, complementary to the receptacle) is brought down from above the pair of cord segments 18A, 18B to a position where the cap is not touching the ends of the cord segments 18A, 18B facing each other, but provides an annular (semicylindrical or hemispherical) gap of suitable size between the cord segments 18A, 18B and the cap. This cap longitudinally overlaps each cord segments 18A, 18B for a suitable distance and may also provide end spacers or seals that contact the cord segments 18A, 18B.

The receptacle and cap together then form a complete circumferential envelope thereby physically captivating the cord segments 18A, 18B along with braze alloy paste layers and braze alloy paste filled gap within an easily removable cable diameter conforming casting envelope which can be made of a suitable heat resistant material such as graphite, ceramic or the like. Depending on the ST rating (diameter) of the steel cable (cord) in the conveyor belt, the longitudinal braze overlap distances may be in the range of 5 mm to 20 mm on each cable end, the braze layer thickness around each of the cables may be in the range of 1 mm to 3 mm, and the braze gap length may be in the range of 5 mm to 20 mm. Thereafter, the braze alloy paste may be heated, e.g. electromagnetically heated, to its melting point and in the process the steel cable ends may also be heated to a lesser temperature in order to promote molten braze alloy wetting and wicking of the exterior and interior of the steel cable ends for a controlled distance. Such a heating process may ensure that the material structure of the steel cables is not altered. After cooling and solidification, the receptacle and cap that together form the complete circumferential envelope may be easily removed and relocated to the next pair of opposing cable ends for its joining operation. As described here, the two ends of the steel cables may be joined together by a formed in-place braze alloy casting in the splice.

FIG. 9A is a cross-sectional view of an example step during formation of the brazing joint 60, involving receiving the cord segments 18A, 18B and brazing paste 68 in a receptacle 62.

FIG. 9B is a cross-sectional view of another example step during formation of the brazing joint 60, involving closing the receptacle 62 using a cap 64 to form a crucible 66.

FIG. 9C is a cross-sectional view of an example step during formation of the brazing joint 60, involving heating the crucible 66 using electromagnetic induction.

The steps in FIGS. 9A-9C may effect the joining of two steel cable ends with a formed in place braze alloy casting.

The cord segments 18A, 18B are disposed in a receptacle 62, end-to-end and spaced apart from each other to define a gap therebetween and/or between the cord segments 18A, 18B and the receptacle 62.

As shown in FIGS. 9A-9C, the receptacle 62 may be elongated and open along the cord segments 18A, 18B. Brazing paste 68 may then disposed into the receptacle 62 to fill such gaps and to at least partially surround the cord segments 18A, 18B.

Once the brazing paste 68 is filled in, a cap 64 may disposed over the cord segments 18A, 18B to close the receptacle 62, e.g. along its elongated and open side, to form a crucible 66 surrounding the brazing paste 68.

In various embodiments, the crucible 66 defines a complete circumferential envelope physically captivating steel cable ends, braze alloy paste layers thereon, and braze alloy paste filled gap within an easily removable encircling encasement (with a defined or predetermined diameter), which may provide ease of use. Such an encasement conforms to the casting envelope and may be made of a suitable heat resistant material such as graphite, ceramic, or the like.

Heating the crucible may then heat the brazing paste 68 to form the brazing joint 60.

In some embodiment, such heating may be provided by induction heating coils 70A, 70B suitably placed adjacent the steel or other cable ends surrounded by braze alloy and the casting envelope. Such an assembly may be rapidly electromagnetically heated in order to melt the braze alloy. Through this controlled heating process, steel cable ends may also be heated to a lesser temperature relative to the braze alloy in order to promote molten braze alloy wetting and wicking of the exterior and interior of the steel cable ends for a controlled distance. For example, heating may occur through electromagnetic induction as well as heating by conduction from the brazing paste 68. The heating process may be configured to ensure that the material structure of the steel cables is not altered.

After forming of the brazing joint, e.g. after cooling and solidification of the brazing paste, the receptacle 62 and cap 64 are removed, e.g. for re-use in another joint. Such steps are not illustrated here.

After the cords 18 are bonded together as described above, the splice can be completed using methods and materials for affixing the elastomeric layers of the conveyor belt together at the point of the splice. For instance, the carry cover layer 22 and the pulley cover layer 24 may be bonded to the reinforcement carcass 20. In form the matrix 36, the brazing joint 60 is directly covered and surrounded by matrix material, e.g. material composing the reinforcement carcass 20.

FIG. 10 is a flow chart of an exemplary method 1000 of forming a zero-stage splice of cord- reinforced conveyor belt by joining a first cord segment to a second cord segment.

Step 1002 of the method 1000 includes disposing in a receptacle the first and second cord segments end-to-end and spaced apart from each other to define a gap. The receptacle may be elongated and open along the first and second cord segments.

Step 1004 of the method 1000 includes disposing brazing paste into the receptacle to fill the gap and to at least partially surround the first and second cord segments.

Step 1006 of the method 1000 includes disposing a cap over the first and second cord segments to close the receptacle to form a crucible surrounding the brazing paste. Step 1008 of the method 1000 includes heating the crucible to heat the brazing paste for forming a joint between the first cord segment and the second cord segment.

Some embodiments of the method 1000 include removing the receptacle and the cap after the joint is formed.

Some embodiments of the method 1000 include, after removing the receptacle and the cap, forming a carry cover layer above the joint and a pulley cover layer below the joint to sandwich the joint.

In some embodiments of the method 1000, the receptacle and cap together form the crucible.

In some embodiments of the method 1000, the receptacle and cap are each semi-cylindrical such that they together form a cylindrical shape defining the crucible.

In some embodiments of the method 1000, the first and second cord segments are substantially stripped of a reinforcement carcass.

In some embodiments of the method 1000, the receptacle includes graphite, and the cap includes graphite.

As can be understood, the examples described above and illustrated are intended to be exemplary only.

The embodiments described in this document provide non-limiting examples of possible implementations of the present technology. Upon review of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made to the embodiments described herein without departing from the scope of the present technology. For example, it is understood that methods for forming splices may be carried out by human operations with or without machine assistance and may be implemented with the aid of kits containing components such as the pliable sheath and the elastomeric adhesive. Yet further modifications could be implemented by a person of ordinary skill in the art in view of the present disclosure, which modifications would be within the scope of the present technology.