A positive displacement sorter, comprising: a plurality of interconnected parallel slats defining an endless web that travels in a longitudinal direction, an upper surface of said web defining an article-conveying surface; a plurality of pusher shoes, each of said shoes travelling along at least one of said slats in order to laterally divert articles on said conveying surface, each of said shoes having a diverting member extending below said conveying surface; a plurality of diverting rails below said conveying surface, each of said diverting rails capable of engaging said diverting member to cause the associated shoe to travel laterally to divert an article; a plurality of diverters, each for selectively diverting at least one of said diverting members from a non-diverting path extending longitudinally along said sorter to one of a plurality of diverting rails in a diverting state; wherein said diverting member comprises a rotary bearing, at least one of said diverters comprising: a gate having a diverting surface, said gate selectively movable between a diverting state and a non-diverting state, wherein said gate positions said diverting surface to engage said bearing in the diverting state; and an actuator moving said gate between the non-diverting state and the diverting state, said actuator comprising an electrically operated rotary actuator, the sorter being characterized in that: the gate is rotatable between said diverting state and said non-diverting state about a generally horizontal axis, and the electrically operated rotary actuator has a generally horizontal axis of rotation. a plurality of interconnected parallel slats defining an endless web that travels in a longitudinal direction, an upper surface of said web defining an article-conveying surface; a plurality of pusher shoes, each of said shoes travelling along at least one of said slats in order to laterally divert articles on said conveying surface, each of said shoes having a diverting member extending below said conveying surface; a plurality of diverting rails below said conveying surface, each of said diverting rails capable of engaging said diverting member to cause the associated shoe to travel laterally to divert an article; a plurality of diverters, each for selectively diverting at least one of said diverting members from a non-diverting path extending longitudinally along said sorter to one of a plurality of diverting rails in a diverting state; wherein said diverting member comprises a rotary bearing, at least one of said diverters comprising: a gate having a diverting surface, said gate selectively movable between a diverting state and a non-diverting state, wherein said gate positions said diverting surface to engage said bearing in the diverting state; and an actuator moving said gate between the non-diverting state and the diverting state, said actuator comprising an electrically operated rotary actuator, the sorter being characterized in that: the gate is rotatable between said diverting state and said non-diverting state about a generally horizontal axis, and the electrically operated rotary actuator has a generally horizontal axis of rotation. a gate having a diverting surface, said gate selectively movable between a diverting state and a non-diverting state, wherein said gate positions said diverting surface to engage said bearing in the diverting state; and an actuator moving said gate between the non-diverting state and the diverting state, said actuator comprising an electrically operated rotary actuator, the sorter being characterized in that: the gate is rotatable between said diverting state and said non-diverting state about a generally horizontal axis, and the electrically operated rotary actuator has a generally horizontal axis of rotation. the gate is rotatable between said diverting state and said non-diverting state about a generally horizontal axis, and the electrically operated rotary actuator has a generally horizontal axis of rotation.