As the world leader in constant force spring technology, John Evans’ Sons (est. 1850) has produced well over 100 million high-performance constant force window balance spring products for the window manufacturing industry.
The following innovations are the result of John Evans’ Sons’ unparalleled experience and technical expertise in window balance springs.
Patent Information by product series.
Di FLEX 500 BALANCE SERIES
…The most flexible constant force balance system for 1/2” sash windows.
Offers the following:
- Ability to transition from a fixed coil balance to an inverted coil balance by simply changing the mounting orientation and attaching a mounting clip to the coil spring.
- Reduced SKUs, springs are pre-assembled in holders (singles and doubles), and quickly make triple and quad assemblies by connecting the spring assemblies.
