Abstract: A device for forcing fluid along a collapsible conduit is described which comprises a yoke including a web and first and second projecting leg members, a first roller supported between the first and second leg members for rotation about a first axis, a block member supporting an axle and a second roller for rotation about a second axis substantially parallel to the first axis, the second leg member and block member each having one or more holes therethrough for receiving bolts connecting the block and second leg member, a spring interconnecting each bolt and the second leg member for resiliently holding the block member and second roller in a substantially parallel juxtaposed position near the second leg member and the first roller, overcenter locking means interconnecting the second leg member and block member for selectively locking the block and second roller into resilient engagement with the second leg member and first roller with a collapsible conduit disposed between the first and second rollers, and a