US Patent 9879829 Tank module interface for fluid reservoirs

The combination of a reservoir having an interface defining an aperture, the interface including a wall extending into the reservoir, the reservoir having a recessed groove in an upper surface about the aperture, the recessed groove including a plurality of recesses thereon: a head unit having an exterior shape complementary to the shape of the aperture, the head unit being positioned within the aperture; the head unit having an inwardly extending rim corresponding to the aperture circular wall, the head unit including a lug, the head unit lug engaging one of recesses, the head unit having a seal ring about an outer periphery of the head unit inwardly extending rim, the seal ring engaging the aperture wall and the head unit inwardly extending rim.