A sorting conveyor for transporting objects and unloading objects at one or more unloading stations adjacent the conveyor. The sorting conveyor includes a conveyor track, a train of conveyor carts connected end-to-end, and an opposed roller motor assembly. The opposed roller motor assembly may include a motor; a support frame attached to the conveyor track for supporting the motor; and a pair of cantilevered, drive rollers connected to the motor and to one pivot block assembly and another pivot block assembly adapted for positioning the drive roller adjacent to one surface of an extended fin driven member. The pivot block assemblies may be coupled together with a self-tensioning adjustment assembly. In some examples, the self-tensioning adjustment assembly may be adapted so that movement of each pivot block assembly mirrors movement of the other pivot block assembly.

一种分选输送机，用于运输物体并且在邻近于该输送机的一个或多个卸载站处卸载物体。该分选输送机包括一个输送机轨道、一连串端对端连接的输送机小车、以及一个对置式滚轮马达组件。该对置式滚轮马达组件可以包括：一个马达；附接至该输送机轨道上用于支撑该马达的一个支撑框架；以及连接至该马达并且连接至一个枢转块组件和另一个枢转块组件上的一对悬臂式连接的驱动滚轮，这些枢转块组件被适配成用于将该驱动滚轮定位一个延伸的鰭状物从动构件的一个表面附近。这些枢转块组件可以与一个自张紧式调节组件联接在一起。在一些实例中，该自张紧式调节组件可以被适配成使得每个枢转块组件的运动是另一个枢转块组件的运动的镜像。