In modern day sash windows, you're a lot more prone to find a spring balance (or sash equilibrium) technique. It is a spring-loaded unit which counters the force of gravity, in influence holding your sash window open up without the require for cords, pulleys and people steel counterweights.  It’s quick https://tweezers-for-shaping-eyeb50503.theisblog.com/35775031/considerations-to-know-about-sash-windows