Abstract: A shaker with an open frame, sides, a flat bottom and open ends. The shaker has pre-lubricated sealed bearings and a self-lubricating plastic gear with a metal gear, which not only educes the amount of friction between gear teeth, reduces maintenance and noise resulting from the gears and enables applicant to provide an integral open frame in which the gears are supported. The gears may be inserted into the frame through the openings in the frame. This provides for easy assembly and the absence of lubricant is especially important in the food industry and other industries where contamination of products would be objectionable.

Abstract: Applicant has discovered that the use of plastic gears in connection with metal gears on a main gear reduces the amount of friction between gear teeth and in addition reduces noise resulting from the assembly. Applicant's shaker herein requires a minimal amount of maintenance and will operate for long periods of time. Moreover, Applicant's shaker requires little or no lubrication. The gears may be disposed between the two parts of the housing and the eccentric weights outside the housing or visa versa.

Abstract: A coupling including a seal which has an outer periphery that is adapted to be pressed into the inner periphery of a hollow cylindrical sleeve of a gear coupling. An annular flange is integrally attached to the ring and the flange extends radially inwardly and toward and is adapted to underlie the external teeth on the hub of the coupling. The flange terminates in an inwardly directed sealing surface that is adapted to sealingly engage an external cylindrical surface on the hub. The sealing surface on the flange is adapted to be disposed on a plane passing through the center of curvature of the tips of the hub teeth perpendicular to the central axis of the coupling.

Abstract: A shaker having a hollow housing in the form generally of two hollow cylinders with the central axes disposed from one another and integrally connected together with a closed end and an end shield covering the second end. A first shaft is supported on bearings in the first cylinder concentric to it, with an eccentric weight attached to the first shaft. A second shaft concentric to the second cylinder is supported on bearings concentric to the second cylinder. Only one end of the housing, the other end is closed, has an end cap and the shafts are connected by helical pinions so that the helical pinions urge the weights and shafts in opposite directions from one another.