John W. Koshak is head and founder of Elevator Safety Solutions, Inc., and a member of Elevator World, Inc.’s Board of Directors and Technical Advisory Group. He is also current president of the International Association of Elevator Consultants. Directly prior to reactivating his company in September 2008, Koshak served as director of Codes and Standards for North America for thyssenkrupp Elevator. He was formerly in research at thyssenkrupp Research, Innovation and Design. Koshak got his start in the industry in 1980 at Westinghouse Elevator Co. and has worked for Dover Elevator, Amtech Elevator and Adams Elevator Equipment Co., where he was vice president of Technical Support. He was a National Elevator Industry Educational Program instructor from 1982 to 1991, designed the LifeJacket hydraulic-elevator safety and holds several patents for elevator-component designs. Koshak is a member of the ASME A17 Standards Committee and a past chairman of the Elevator Escalator Safety Foundation.
Conclusion of series examines components used in electric elevator systems that provide safe traction. In Part 1 (ELEVATOR WORLD, August 2017), we learned the design basics of traction, starting with friction up to how a designer establishes the required traction and then uses angle of wrap and groove design to ensure there is always adequate…Read More
Unintended loss of traction, resulting from component deterioration, for example, is very hazardous and can allow an elevator to move uncontrolled. Four factors determine and control traction: The traction ratio of car and counterweight The area of contact of hoist ropes on the drive sheave The coefficient of friction/friction factor between the hoist ropes and…Read More