Force and form closure Force closure Gravity constraint spring constraint Weight constraint: the weight of the follower system is sufficient to maintain contact Spring constraint: the spring must be properly designed to maintain contact 1. Form closure a groove maintains positive action. Grooved cam mechanism) A constant-diameter cam or conjugate cam a constant-diameter cam Q(房 (等径凸轮) 力分x a dual or conjugate cam (共轭凸轮)Force and form closure 1. Force closure:Gravity constraint & Spring constraint: Weight constraint:the weight of the follower system is sufficient to maintain contact. Spring constraint: the spring must be properly designed to maintain contact. 1. Form closure: A groove maintains positive action.(Grooved cam mechanism) A constant-diameter cam or conjugate cam. a dual or conjugate cam (共轭凸轮) a constant-diameter cam (等径凸轮)