Patent Description:
Elevator systems are useful for carrying passengers, cargo, or both, between various levels in a building. Some elevators are traction based and utilize load bearing members such as ropes or belts for supporting the elevator car and achieving the desired movement and positioning of the elevator car.

Where belts are used as a load bearing member, a polyurethane sheath or skin is typically positioned over and adhered to a polymer matrix composite (PMC) core. In at least some belts, poor adhesion between a polyurethane or other elastomer sheath and the polymer matrix composite core, for example carbon fiber/epoxy, of a composite belt remains a challenge even after reactivation, for example plasma, mechanical, or chemical reactivation, of the PMC core to the elastomer sheath extrusion or coating application. Additionally, the fiber/epoxy composite core and the elastomer have poor fire resistance. Fire retardation standards are some of the key safety requirements that each belt is required to meet.

A need remains for a polymer composite belt design that promotes adhesion between the polyurethane sheath/skin and the PMC core, and also improves flame resistance.

<CIT> discloses a belt for drive systems, said belt consisting of an elastic and flame-retardant belt body made from a polymeric material and at least one flame retardant additive.

<CIT> discloses a rope of a lifting device, an elevator, and a method for manufacturing the rope.

In one aspect, a belt for an elevator system (e.g. an elevator system as herein described) comprises:.

In an aspect of any of the above, the core is at least one of but not limited to a carbon fiber or aramid fiber or glass fiber thermoset polymer resin composite core, or a carbon fiber or aramid fiber or glass fiber epoxy or polyurethane or bis-maleimid or phenolic or polyimide or polyester or silicone thermoset polymer resin composite core, or mixtures and blends thereof.

In an aspect of any of the above, the core is at least one of a carbon fiber thermoset resin composite core, an aramid fiber thermoset resin composite core, a glass fiber thermoset resin composite core, an epoxy thermoset resin composite core, and combinations thereof.

In an aspect of any of the above, the elastomer and phosphonate blended bonding agent includes at least one of but not limited to a poly-phosphonate homopolymer, phosphonate oligomer, phosphonate carbonate co-oligomer, poly-phosphonate-polycarbonate copolymer, phosphonate ester co-oligomer, and poly-phosphonate-polyester copolymer and blends thereof.

In an aspect of any of the above, the at least one of but not limited to poly-phosphonate homopolymer, phosphonate oligomer, phosphonate carbonate co-oligomer, poly-phosphonate-polycarbonate copolymer, phosphonate ester co-oligomer, and poly-phosphonate-polyester copolymer (and optionally blends thereof) are blended in a weight within a range of <NUM>% to <NUM>% in an embodiment, within a range of <NUM>% to <NUM>% in another embodiment, and within a range of <NUM>% and <NUM>% in another embodiment.

In an aspect of any of the above, the elastomer and phosphonate blended bonding agent is formed as a tie-layer positioned between the core and the sheath.

In an aspect of any of the above, the tie-layer is extruded onto the core, and the sheath is extruded onto the tie-layer.

In an aspect of any of the above, the tie layer is applied by pultrusion onto the core; and the sheath is applied by pultrusion onto the tie layer.

In an aspect of any of the above, the sheath is extruded onto the core.

In an aspect of any of the above, the sheath is applied by pultrusion onto the core.

In one aspect, an elevator system comprises:.

In one aspect, a method of forming a belt (e.g. a belt as herein described) for an elevator system (e.g. an elevator system as herein described), comprises:.

In an aspect of the above, the method includes providing a core includes providing at least one of but not limited to a carbon fiber or aramid fiber or glass fiber thermoset polymer resin composite core, or a carbon fiber or aramid fiber or glass fiber epoxy or polyurethane or bis-maleimid or phenolic or polyimide or polyester or silicone thermoset polymer resin composite core, or mixtures and blends thereof.

In an aspect of any of the above, providing a core includes providing at least one of a carbon fiber thermoset resin composite core, an aramid fiber thermoset resin composite core, a glass fiber thermoset resin composite core, an epoxy thermoset resin composite core, and combinations thereof.

In an aspect of any of the above, the elastomer and phosphonate blended bonding agent includes at least one of but not limited to poly-phosphonate homopolymer, phosphonate oligomer, phosphonate carbonate co-oligomer, poly-phosphonate-polycarbonate copolymer, phosphonate ester co-oligomer and poly-phosphonate-polyester copolymer, and blends thereof.

In an aspect of any of the above, the method includes blending the at least one of but not limited to poly-phosphonate homopolymer, phosphonate oligomer, phosphonate carbonate co-oligomer, and poly-phosphonate-polycarbonate copolymer, phosphonate ester co-oligomer and poly-phosphonate-polyester copolymer in a weight within a range of <NUM>% to <NUM>% in an embodiment, within a range of <NUM>% to <NUM>% in another embodiment, and within a range of <NUM>% and <NUM>% in another embodiment.

In an aspect of any of the above, the method includes forming the elastomer and phosphonate blended bonding agent as a tie-layer positioned between the core and the sheath.

In an aspect of any of the above, the elastomer is a thermoplastic polyurethane (TPU) or other thermoplastic or thermosetting elastomer polymer or rubber.

Referring now to <FIG>, an exemplary embodiment of an elevator system <NUM> is illustrated. The elevator system <NUM> includes an elevator car <NUM> configured to move vertically upwardly and downwardly within a hoistway <NUM> along a plurality of car guide rails (not shown). Guide assemblies mounted to the top and bottom of the elevator car <NUM> are configured to engage the car guide rails to maintain proper alignment of the elevator car <NUM> as it moves within the hoistway <NUM>.

The elevator system <NUM> also includes a counterweight <NUM> configured to move vertically upwardly and downwardly within the hoistway <NUM>. The counterweight <NUM> moves in a direction generally opposite the movement of the elevator car <NUM>. Movement of the counterweight <NUM> is guided by counterweight guide rails (not shown) mounted within the hoistway <NUM>. In the illustrated, non-limiting embodiment, at least one load bearing member <NUM>, for example, a belt, coupled to both the elevator car <NUM> and the counterweight <NUM> cooperates with a traction sheave <NUM> mounted to a drive machine <NUM>. To cooperate with the traction sheave <NUM>, at least one load bearing member <NUM> bends in a first direction about the traction sheave <NUM>. Although the elevator system <NUM> illustrated and described herein has a <NUM>:<NUM> roping configuration, elevator systems <NUM> having other roping configurations and hoistway layouts are within the scope of the present disclosure.

<FIG> illustrates a composite belt <NUM> including a polyurethane or elastomer or rubber sheath or skin <NUM>. In one embodiment, the polyurethane sheath <NUM> is an extruded thermoplastic polyurethane (TPU) sheath. The belt <NUM> also includes a polymer matrix composite core <NUM>, for example, a carbon fiber/epoxy thermoset resin composite core. A coated or co-extruded adhesive tie-layer <NUM> is provided between the sheath <NUM> and the core <NUM>. In one embodiment, the adhesive tie-layer <NUM> includes a polymer blend of a TPU or elastomer or rubber and at least one of a poly-phosphonate homopolymer, phosphonate oligomer, phosphonate carbonate co-oligomer, poly-phosphonate-polycarbonate copolymer, phosphonate ester co-oligomer, poly-phosphonate-polyester copolymer or a combination thereof.

Referring now to <FIG>, in an embodiment of the belt <NUM>, the adhesive tie-layer <NUM> includes one or more layers that are fully internal to the sheath <NUM>. The adhesive tie-layer <NUM> at least partially surrounds and/or encapsulated one or more sections of the core <NUM> as illustrated. The embodiment of <FIG> allows the sheath <NUM> to be positioned between one or more pultrusions in an embodiment, explained in further detail below, of the tie-layer <NUM>.

The core <NUM> of one or more embodiments is constructed of a structural component and a binder to form a monolithic tension element. The structural component can be carbon fiber, aramid fiber, glass fiber, and/or other materials with sufficiently high specific tensile strength. In an embodiment, a fiber alignment of the structural material is substantially parallel. The fiber alignment is at least <NUM>% aligned in the length direction in an embodiment and at least <NUM>% aligned in the length direction in another embodiment. The binder or material that holds the structural component together is constructed of a thermosetting material in an embodiment, such as epoxy, polyurethane, bis-maleimid, phololic, polyimide, or silicone material or a thermoplastic material to name non-limiting examples. Additional components/materials are added to the thermoset material in an embodiment to improve bonding and other features of the core material. In one non-limiting example, one or more phosphonate oligomer or polymers are added to the binder or material that holds the structural component together at a concentration of between <NUM>% and <NUM>%.

The core <NUM> of one or more embodiments has any cross sectional geometry including, circular, oval, hexagonal or quadrilateral to name non-limiting examples. In an embodiment, the cross sectional geometry of the core <NUM> is a quadrilateral with an aspect ratio greater than one, i.e., rectangular, where its long axis is parallel to the traction surface. The thickness of the core <NUM> in an embodiment is between <NUM> and <NUM> and, in another embodiment, is between <NUM> and <NUM>. In embodiments having a quadrilateral geometry, the thickness of the core <NUM> is between <NUM> and <NUM> and the width of the core <NUM> is between <NUM> and <NUM>. In embodiments having a rounded geometry, such as circular and ovoid geometries to name two non-limiting examples, a radius is between <NUM> and <NUM> in an embodiment and between <NUM> and <NUM> in another embodiment.

In one embodiment, the phosphonate containing oligomers and polymers form miscible blends with TPU or elastomer or rubber polymers as well as with epoxy thermoset resins. Accordingly, in one embodiment, the adhesive tie-layer <NUM> has chemical affinity to both the sheath <NUM> and the core <NUM>, and can therefore act as an adhesive tie-layer between the sheath and the core material. The phosphonate oligomers and polymers are flame retardant (FR) additives for TPUs or elastomers or rubbers and epoxy resins in low loading levels (<NUM>% to <NUM>% wt by way of non-limiting example and <NUM>% to <NUM>% wt by way of another non-limiting example) and can be blended into the respective polymers to form a sheathed composite belt with improved fire resistance.

The TPU or thermoplastic elastomer or thermoplastic rubber/phosphonate oligomer polymer blends are melt extrudable. Accordingly, the tie-layer <NUM> and the sheath <NUM> can be extruded or co-extruded or extrusion coated or co-extrusion coated onto the composite belt core <NUM>. Alternatively the tie-layer <NUM> can be applied as a solvent-borne coating onto the belt core <NUM> by running the belt <NUM> through a bath or through other on-line coating applicators, for example a flooded rolls nip, a metered roll application, etc. The sheath <NUM> can then be extruded onto the tie-layer coated belt core <NUM>. In one embodiment, the belt <NUM> may enable the use of the same or other FR additives in the TPU or elastomer or rubber sheath <NUM> and core <NUM> as may be necessary for improved belt properties, for example traction/slip, flex, wear, etc..

In one or more embodiments, the tie-layer <NUM> is extruded onto the belt core <NUM>. In an embodiment, the sheath <NUM> is extruded onto the tie-layer <NUM>. In an embodiment, the sheath <NUM> is extruded onto the core <NUM>.

In one or more embodiments, the tie-layer <NUM> is applied by pultrusion onto the belt core <NUM>. In an embodiment, the sheath <NUM> is applied by pultrusion onto the tie-layer <NUM>. In an embodiment, the sheath <NUM> is applied by pultrusion onto the core <NUM>.

In an alternative embodiment, illustrated in <FIG>, a belt <NUM> includes phosphonate oligomer or polymers that are added to at least one of a sheath <NUM> and a core <NUM> for adhesive compatibility and FR. The elastomer and phosphonate blended bonding agent may be mixed with a resin that forms the core. Alternatively, the elastomer and phosphonate blended bonding agent may be mixed with a resin that forms the sheath. In one embodiment, the elastomer and phosphonate blended bonding agent is mixed with a resin that forms the core and a resin that forms the sheath.

In an embodiment, the sheath <NUM> is extruded onto the core <NUM>. The sheath <NUM> of an embodiment includes a thermosetting elastomer or rubber polymer blended with polyphosphonates bonding additive polymers or oligomers. The sheath <NUM> of an embodiment is applied by pultrusion onto the preformed core <NUM>. The core <NUM> is formed by pultrusion in an embodiment. The polyphosphonate bonding additives are included in a resin of the core(s) <NUM> in one or more embodiments.

In one embodiment, the adhesion between the sheath <NUM>, <NUM> and a core <NUM>, <NUM> may improve fire resistance performance of the respective belt <NUM>, <NUM>. In one embodiment, the fire resistance performance of the resulting belt may be improved without the use of halogens or other substances that are not recommended for building applications. Additionally, the oligomeric additives may not embrittle or substantially deteriorate the mechanical properties of the elastomer or the epoxy. In one embodiment, the additives may toughen the resulting material or be employed as the cross-linker or hardening agent in urethanes and epoxies, respectively.

Claim 1:
A belt (<NUM>, <NUM>) for an elevator system (<NUM>) comprising:
a core (<NUM>, <NUM>);
an elastomeric sheath (<NUM>, <NUM>) positioned over the core (<NUM>, <NUM>); and
an elastomer and phosphonate blended bonding agent adhering the core (<NUM>, <NUM>) to the sheath (<NUM>, <NUM>);
characterised in that the elastomer and phosphonate blended bonding agent is mixed with a resin that forms the core (<NUM>, <NUM>).