# US 9,038,783 B2 · Rope sway mitigation via rope tension adjustment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,038,783 B2 - Document ID: US9038783B2 - Status: Granted - Kind: B2 - Application number: 13/387,595 - Filed: 2009-07-29 - Published: 2012-05-24 - Granted: 2015-05-26 - Earliest claimed: 2009-07-29 - Assignees: Otis Elevator Company - Applicants: Randall Keith Roberts; Mark R. Gurvich; Richard N. Fargo - Inventors: Randall Keith Roberts; Mark R. Gurvich; Richard N. Fargo - Web page: https://patentgrep.com/patent/US9038783B2 ## CPC - B66B 7/068: {Cable weight compensating devices} - B66B 7/08: for connection to the cars or cages, e.g. couplings - B66B: ELEVATORS; ESCALATORS OR MOVING WALKWAYS ({apparatus for raising or lowering persons on theatrical stages or the like A63J5/12} ; funicular railbound systems with rigid ground-supported tracks and cable traction, e.g. cliff railways, B61B9/00; arrangements of ammunition handlers in vessels B63G3/00; hoists, lifts, or conveyors for loading or unloading in general B65G; braking or detent devices controlling normal movements of winding drums or barrels B66D; ship-lifting devices E02C; garages for many vehicles with mechanical means for lifting vehicles E04H6/12; hoists for feeding ammunition or projectiles to launching apparatus or to loading mechanisms F41A9/00) ## Abstract A rope sway mitigation device for an elevator system includes a rope tension adjuster connected to a plurality of ropes operably connected to an elevator car. The rope tension adjuster is configured to adjust a tension of at least one individual rope of the plurality of ropes thereby mitigating excitation of natural frequencies of the plurality of ropes during sway of at least one component of the elevator system and or a building in which the elevator system is located. Further disclosed is an elevator system including a rope sway mitigation device and a method of rope sway mitigation in an elevator system. ## Claims ### Claim 1 An elevator system comprising: an elevator car having a plurality of ropes operably connected thereto; a sway detection sensor configured to detect sway of at least one component of the elevator system and/or a building in which the elevator system is disposed; and a rope tension adjuster in operable communication with the sway detection sensor, the rope tension adjuster configured to increase a tension of at least one of the individual ropes of the plurality of ropes and to decrease a tension of at least one of the individual ropes of the plurality of ropes to mitigate excitation of natural frequencies of at least one of the plurality of ropes when the sway detection sensor detects sway of the at least one component of the elevator system and/or the building. ### Claim 2 (depends on 1) The elevator system of claim 1 wherein the rope tension adjuster increases tension on a first group of ropes of the plurality of ropes and decreases a tension on a second group of ropes of the plurality of ropes. ### Claim 3 (depends on 1) The elevator system of claim 1 wherein a total tension of the plurality of ropes remains substantially constant. ### Claim 4 (depends on 1) The elevator system of claim 1 wherein the rope tension adjuster comprises a plurality of hydraulic cylinders connected to the plurality of ropes. ### Claim 5 (depends on 4) The elevator system of claim 4 including a pump that urges fluid from a first group of hydraulic cylinders of the plurality of hydraulic cylinders to a second group of hydraulic cylinders of the plurality of hydraulic cylinders. ### Claim 6 (depends on 5) The elevator system of claim 5 wherein fluid pumped to the second group of hydraulic cylinders increases a tension of the ropes of the plurality of ropes connected thereto. ### Claim 7 (depends on 5) The elevator system of claim 5 wherein pumping fluid from the first group of hydraulic cylinders decreases a tension of the ropes of the plurality of ropes connected thereto. ### Claim 8 (depends on 1) The elevator system of claim 1 wherein the plurality of ropes comprise suspension ropes and/or compensation ropes. ### Claim 9 A rope sway mitigation device for an elevator system comprising: a rope tension adjuster connected to a plurality of ropes connected to an elevator car, the rope tension adjuster configured to increase a tension of at least one individual rope of the plurality of ropes and decrease a tension of at least one individual rope of the plurality of ropes thereby preventing excitation of natural frequencies of the plurality of ropes during a building sway event. ### Claim 10 (depends on 9) The rope sway mitigation device of claim 9 wherein the rope tension adjuster increases tension on a first group of ropes of the plurality of ropes and decreases a tension on a second group of ropes of the plurality of ropes. ### Claim 11 (depends on 9) The rope sway mitigation device of claim 9 wherein a total tension of the plurality of ropes remains substantially constant. ### Claim 12 (depends on 9) The rope sway mitigation device of claim 9 wherein the rope tension adjuster comprises a plurality of hydraulic cylinders connected to the plurality of ropes. ### Claim 13 (depends on 12) The rope sway mitigation device of claim 12 including a pump that urges fluid from a first group of hydraulic cylinders of the plurality of hydraulic cylinders to a second group of hydraulic cylinders of the plurality of hydraulic cylinders. ### Claim 14 (depends on 13) The rope sway mitigation device of claim 13 wherein fluid pumped to the second group of hydraulic cylinders increases a tension of the ropes of the plurality of ropes connected thereto. ### Claim 15 (depends on 13) The rope sway mitigation device of claim 13 wherein pumping fluid from the first group of hydraulic cylinders decreases a tension of the ropes of the plurality of ropes connected thereto. ### Claim 16 (depends on 12) The rope sway mitigation device of claim 12 including a solenoid valve configured to equalize tension on the plurality of ropes. ### Claim 17 A method of rope sway mitigation in an elevator system comprising: detecting sway of at least one component of the elevator system and/or a building in which the elevator system is disposed; increasing tension of at least one of a plurality of ropes operably connected to an elevator car and decreasing tension of at least one of the plurality of ropes operably connected to the elevator car in response to detection of sway of the at least one component of the elevator system and/or the building; and mitigating excitation of natural frequencies of the plurality of ropes via the tension adjustment thereby preventing sway of the plurality of ropes. ### Claim 18 (depends on 17) The method of rope sway mitigation of claim 17 comprising increasing a tension on a first group of ropes of the plurality of ropes and decreasing a tension on a second group of ropes of the plurality of ropes. ### Claim 19 (depends on 17) The method of rope sway mitigation of claim 17 comprising urging hydraulic fluid into a first group of hydraulic cylinders connected to a first group of ropes of the plurality of ropes thereby increasing a tension on the first group of ropes and decreasing a tension on a second group of ropes of the plurality of ropes. ### Claim 20 (depends on 19) The method of rope sway mitigation of claim 19 comprising: detecting an end of the sway of the at least one component of the elevator system and/or the building; and urging hydraulic fluid away from the first group of hydraulic cylinders thereby equaling tension of individual ropes of the plurality of ropes.