Cordless, balanced venetian blind or shade with consistent variable force spring motor

摘要: A cordless, balanced venetian blind or shade with a constant variable spring motor includes conventional window covering components without the outside hanging lifting cords cord locking mechanisms. One more force motors are employed, preferably comprising springs which vary in thickness width along their length as they wound around storage drums. spool, preferred embodiment, is coupled to one of drums serve wind cause be raised lowered, simply by manipulation bottom bar system. Due difference spring, system compensates for increasing weight on and decreasing it lowered.