Roller conveyor with friction roll drive

Claim 1

A conveyor which comprises a stationary frame, a plurality of article supporting rollers rotatably mounted on the frame for rotation about respective axes in fixed relation to the frame, a plurality of housings pivotally mounted on the frame below the rollers, a friction roll rotatably mounted in each housing, each friction roll being adapted to drive at least one of the article supporting rollers, the axis of each friction roll and the axis of swinging of each housing being parallel to the axis of the associated article supporting roller, a diaphragm engageable with each housing, means for supplying fluid under a selected pressure to each of the diaphragms to cause each diaphragm to raise the associated housing to bring the associated friction roll into driving relation to the associated article supporting roller to provide a friction drive thereof while resistance to turning of said supporting roll does not exceed a magnitude corresponding to the selected pressure, and means for driving the friction rolls to drive the article supporting rollers, the means for driving the friction rolls including a sprocket member mounted on each friction roll, a drive chain course in mesh with the sprocket member, and a bottom plate releasably mounted on each housing underlying the drive chain course to hold the drive chain course in mesh with the associated sprocket member when the bottom plate is in a first position, the bottom plate being movable to a second position to release the drive chain course to permit disengagement of the drive chain course from the associated housing and sprocket member.