BACKGROUND

Embodiments disclosed herein relate to elevator systems, and more particularly to load bearing members to suspend and/or drive elevator cars of an elevator system.

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 belts for supporting the elevator car and achieving the desired movement and positioning of the elevator car.

Where a belt is used as a load bearing member, a plurality of tension elements, or cords, are embedded in a common jacket. The jacket retains the cords in desired positions and provide a frictional load path. In an exemplary traction elevator system, a machine drives a traction sheave with which the belts interact to drive the elevator car along a hoistway. Belts typically utilize tension members formed from steel elements, but alternatively may utilize tension members formed from synthetic fibers or other materials, such as carbon fiber composites.

In a carbon fiber composite tension member, the members are typically very stiff in bending, and at cross-sectional areas of tension members desired to provide a selected tensile performance, the tension member may be damaged under bending.

BRIEF DESCRIPTION

In one embodiment, a belt for an elevator system includes a plurality of tension members arranged along a belt width and extending longitudinally along a length of the belt. Each tension member includes a core member formed from a plurality of load carrying fibers, and a plurality of overwrap members surrounding the core member. A jacket material at least partially encapsulates the plurality of tension members.

Additionally or alternatively, in this or other embodiments the plurality of load carrying fibers are positioned in a matrix material.

Additionally or alternatively, in this or other embodiments the load carrying fibers are one or more of carbon, glass, aramid, nylon, and polymer fibers.

Additionally or alternatively, in this or other embodiments the matrix material is a polyurethane, polyester, vinylester, or epoxy material.

Additionally or alternatively, in this or other embodiments the plurality of overwrap members are synthetic fibers.

Additionally or alternatively, in this or other embodiments the synthetic fibers are one or more of Vectran™ or Dyneema® or Zylon® fibers.

Additionally or alternatively, in this or other embodiments the plurality of overwrap members are metallic wires.

Additionally or alternatively, in this or other embodiments the plurality of overwrap fibers are wrapped or braided around the core member. Additionally or alternatively, in this or other embodiments the jacket material is selected from the group consisting of polyurethanes, polyesters, ethylene propylene diene elastomer, chloroprene, chlorosulfonyl polyethylene, ethylene vinyl acetate, polyamide, polypropylene, butyl rubber, acrylonitrile butadiene rubber, styrene butadiene rubber, acrylic elastomer, fluoroelastomer, silicone elastomer, polyolefin elastomer, styrene block and diene elastomer, natural rubber or combinations thereof.

In another embodiment, an elevator system includes a hoistway, an elevator car positioned in the hoistway and movable therein, and a belt operably connected to the elevator car to suspend and/or drive the elevator car along the hoistway. The belt includes a plurality of tension members arranged along a belt width and extending longitudinally along a length of the belt. Each tension member includes a core member formed from a plurality of load carrying fibers, and a plurality of overwrap members surrounding the core member. A jacket material at least partially encapsulates the plurality of tension members.

Additionally or alternatively, in this or other embodiments the plurality of load carrying fibers are positioned in a matrix material.

Additionally or alternatively, in this or other embodiments the load carrying fibers are one or more of carbon, glass, aramid, nylon, and polymer fibers.

Additionally or alternatively, in this or other embodiments the matrix material is a polyurethane, vinylester, polyester, or epoxy material.

Additionally or alternatively, in this or other embodiments the plurality of overwrap members are synthetic fibers.

Additionally or alternatively, in this or other embodiments the plurality of overwrap members are metallic wires.

Additionally or alternatively, in this or other embodiments the plurality of overwrap members are configured to suspend the elevator car in the event of failure of the core member.

Additionally or alternatively, in this or other embodiments the jacket material is selected from the group consisting of polyurethanes, polyesters, ethylene propylene diene elastomer, chloroprene, chlorosulfonyl polyethylene, ethylene vinyl acetate, polyamide, polypropylene, butyl rubber, acrylonitrile butadiene rubber, styrene butadiene rubber, acrylic elastomer, fluoroelastomer, silicone elastomer, polyolefin elastomer, styrene block and diene elastomer, natural rubber, or combinations thereof.

