Patent ID: 6868960

Claim:
A conveying apparatus comprising: a supporting frame: an article transporting bed which is oriented in spaced relation relative to the supporting frame; a first sensor borne by the article transporting bed; a second sensor borne by the supporting frame; a plurality of resilient supports mounted on both the supporting frame and the article transporting bed and which supports the article transporting bed in spaced relation relative to the supporting frame; a drive frame borne by the supporting frame; a third sensor borne by the drive frame, and wherein the first, second and third sensors each provide an output signal; a motor mounted on the device frame, and which rotates an eccentric mass to produce an oscillating force having a plurality of components; a moveable drive mass borne by the drive frame and which is influenced by the oscillating force; a spring mounted on both the drive frame, and on the supporting frame, and which influences the moveable drive mass, and wherein the spring has a variable spring rate, and wherein the plurality of components of the oscillating force which are at a given angle relative to the resilient supports may be controllably amplified by varying the spring rate of the spring; and a controller coupled in signal receiving relation relative to the output signals of each of the first, second and third sensors, and further coupled in speed controlling relation relative to the motor, and wherein the controller receives and utilizes the output signals of the respective sensors to determine a vibrational phase and amplitude of the article transporting bed relative to the supporting frame, and wherein the controller adjusts the speed of operation of the motor to substantially maintain the vibrational amplitude within a predetermined range.