Patent ID: 6883955

Claim:
A system for agitating a liquid-containing can, comprising: an outer frame; an inner frame mounted to the outer frame and mechanically isolated therefrom, the inner frame comprising a can support location, a clamping plate, and means for supporting the clamping plate for movement toward and away from the can support location; a drive motor for driving the inner frame in order to agitate the can; a microprocessor; a clamping motor operable according to instructions of the microprocessor to drive the means for supporting the clamping plate to change the position of the clamping plate; an encoder for detecting the position of the clamping plate relative to the can support location; and means for detecting a current draw of the clamping motor, the means for detecting configured to detect the current draw for a baseline reference state, representing a state of operation when the clamping motor is driving the means for supporting the clamping plate without engagement thereof with a can at the can support location, and a clamping state, representing a prevailing actual state of operation when the clamping motor is driving the means for supporting the clamping plate into engagement with a can present at the can support location; the microprocessor being programmed to control movement of the clamping plate according to a subtractive comparison wherein the baseline reference state current draw is repetitively subtracted from the clamping state current draw and to stop and at least maintain the clamping plate in a can clamping position in response to a predetermined positive value of the subtractive comparison representing clamping engagement of the clamping plate with a can.