Patent ID: 8342313

Claim:
A conveyor comprising: a conveyor belt advancing in a direction of belt travel from an upstream end to a downstream end, wherein the conveyor belt includes a plurality of rollers extending through the thickness of the conveyor belt and rotatable in the direction of belt travel; a movable stop positioned along the conveyor; a first actuator coupled to the movable stop to move the movable stop between a blocking position blocking conveyed articles and a release position allowing articles to pass; a movable bearing surface disposed below the conveyor belt in a carryway zone extending proximate to and upstream from the movable stop; a second actuator movable into and out of contact with the rollers from below to cause the rollers to rotate by frictional rolling contact with the bearing surface when in contact with the rollers as the conveyor belt advances; wherein the rollers in the conveyor belt not contacting the bearing surface are freely rotatable; and wherein the operation of the first and second actuators is coordinated so that the movable bearing surface is in contact with the rollers when the movable stop is in the release position to propel articles downstream past the movable stop in the release position and wherein the movable bearing surface is out of contact with the rollers when the movable stop is in the blocking position to allow blocked articles to accumulate under the freely rotatable rollers upstream of the stop in the blocking position with low back line pressure.