3.4 Characteristics analysis of four-bar linkages 1. The grashof condition(曲柄存在条件) 2. Fourbar Quick-Return(急回特性) r3 Transmission angle pressure angle (传动角与压力角) r4 Toggle positions Dead-points (极限位置与死点) 5. Mechanical advantage(机械增益)3.4 Characteristics Analysis of four-bar linkages 1. The Grashof condition(曲柄存在条件) 2. Fourbar Quick-Return （急回特性） 3. Transmission angle & Pressure angle （传动角与压力角） 4. Toggle positions & Dead-points （极限位置与死点） 5. Mechanical advantage（机械增益）