Abstract: A clamping mechanism is provided for mixing apparatuses and other apparatuses that utilize clamping mechanisms. The clamping mechanism incorporates a clutch mechanism which prevents overtightening of the clamp mechanism in the closed or clamping direction. Also, the clamping mechanism incorporates a plurality of pins that serve as a stop to prevent the traveling arm of the clamp mechanism from being tightened against the stationary arm and further serve as a bias for the clutch mechanism to bias the male and female clutch components into a mating engagement thereby enabling the clamping mechanism to be easily rotated out of the fully open position and prevent a jamming of the clamping mechanism in the fully open position.

Abstract: Mixing apparatus develops a clamping pressure on a container to be mixed by bringing a pair of pressure plates together through the application of driving force developed by cranking a crank arm. A pawl and rachet arrangement prevents rotation of the crank arm in a direction which would loosen clamping pressure, unless a pawl unlocking knob is activated. Clamping pressure is limited by a clutch plate arrangement. Mixing apparatus is enclosed within a cabinet having a door interlock system which also automatically activates a brake for positively stopping further movement of the mixing apparatus.