which defines a lower camming surface which then projects upwardly from the end of which is a vertically oriented finger gripping portion 86 which vertically oriented finger gripping portion 86 is that portion thereof that actually contacts and clamps the lower rim of the paint can or container 30 as clearly shown infig8 the lower camming surfaces of the transition portions 84 are that part of the gripping jaws against which the upper contact surface of the contact plate 60 abuts for causing the upward pivotal movement of the jaws during rotation of the threaded shafts 40 and 42 which in turn causes the upward movement of the spider 34 39 during the clamping process prior to actual mixing via the apparatus 10 the clamping plate 28 is also provided with a plurality of circumferentially located notches 90 as seen in fig9 which receive therethrough the projections of the finger gripping portions 86 of the plurality of jaws 80 the interior surfaces of the finger gripping portions 86 snugly enclose therein the lower rim of the paint can 30 to thereby not only firmly grasp the lower portion of the can to aid in the rotation thereof with the lower clamping plate 36 but also to achieve automatic centering of the can on the lower platen 28 during the clamping process it may therefore be seen that upon rotation of threaded shafts 40 and 42 to cause the upward movement of the spider 34 39 strike plate 60 firstly causes the upward pivotal movement of the six clamping jaws 80 to the point where they are in.