Patent ID: 7614970

Claim:
A torque sensing assembly for an agricultural machine, comprising: an axially fixed sheave having an axis of rotation; an axially movable sheave movable along said axis in relation to said axially fixed sheave; a compression spring having a first end and a second end, said first end being positioned to engage said axially movable sheave; and a dual stage spring compression mechanism having a spring retainer that engages said second end of said compression spring, said dual stage spring compression mechanism being connected to said axially fixed sheave, said dual stage spring compression mechanism having a first stage compression device that compresses said compression spring by a first preload amount and a second stage compression device that compresses said compression spring by a second preload amount, said axially fixed sheave includes a first set of threaded holes and a second set of threaded holes, said first stage compression device including a first set of bolts that engage said first set of threaded holes, wherein tightening said first set of bolts compresses said compression spring by said first preload amount, said second stage compression device including a second set of bolts that engage said second set of threaded holes after said compression spring is compressed by said first preload amount, wherein tightening said second set of bolts compresses said compression spring by said second preload amount, said dual stage spring compression mechanism includes a spring preload ring, and a slide coupling that connects said spring preload ring to said spring retainer, said spring preload ring having a first plurality of holes through which said first set of bolts extend, each of said first set of bolts having a head that engages said spring preload ring to compress said compression spring when said first set of bolts are tightened.