Patent ID: 8020669

Claim:
An elevator, comprising: an elevator car; a counterweight; a set of hoisting ropes; a traction sheave of a first material; one or more first rope pulleys on the elevator car; one or more second rope pulleys on the counterweight; elevator car guide rails; and counterweight guide rails; wherein the elevator car is suspended on the set of hoisting ropes using the one or more first rope pulleys, wherein the counterweight is suspended on the set of hoisting ropes using the one or more second rope pulleys, wherein the elevator car moves on the elevator car guide rails, wherein the counterweight moves on the counterweight guide rails, wherein the set of hoisting ropes includes a plurality of individual hoisting ropes, each having a substantially round cross-section, wherein each individual hoisting rope includes a load-bearing part twisted from steel wires, wherein the traction sheave is provided with a plurality of rope grooves, wherein each of the rope grooves comprises a solid surface of the first material, wherein each of the rope grooves generally conforms to a substantially circular shape, has a groove bottom and groove sides and has an opening for receiving one of the individual hoisting ropes, wherein a width of the opening is less than a diameter of the rope groove, wherein the traction sheave has a coating adhesively bonded to each of the plurality of rope grooves, wherein at the groove bottom of each of the rope grooves, a thickness of the coating, measured in a direction perpendicular to a rotation axis of the traction sheave, from a hoisting-rope-contacting surface of the coating to the solid surface of the first material, is less than or equal to about 3 mm, wherein at the groove bottom of each of the rope grooves, the thickness of the coating, measured in the direction perpendicular to the rotation axis of the traction sheave, from the hoisting-rope-contacting surface of the coating to the solid surface of the first material, is substantially less than half a thickness of the individual hoisting rope running in the respective rope groove, wherein at the groove sides of each of the rope grooves, the thickness of the coating is less than or equal to about 3 mm, wherein, in each rope groove, the coating has a crescent-shaped cross-section covering the groove bottom and the groove sides of the rope groove, and wherein the coating is thicker at the groove bottom of each of the rope grooves than at the groove sides of the respective rope groove.