Abstract: Anti-entrapment drain cover [A] for pools is formed by a molded wheel-like cover unit [10] of radial dimensions greater than the radius of any pool sump or drain [10] to be covered, so as to extend over the drain floor radially beyond the drain. Radial ribs [14] below the cover unit define channels opening at the periphery to provide a side inlet [18] between each rib pair so that the periphery stands off the surface sufficiently for water flow through the inlets but with spacing insufficient for user grasping of the cover. Arcuate inlet recesses [20] open periphery between rib pairs, so water flows into the channels for draining without potential for pool user entrapment even if a pool user attempts to block them. Securements are such that the cover, which is user unbreakable, cannot be pulled away by the user.

Abstract: An anti-entrapment, anti-vortex swimming pool and/or wading pool drain cover having a discus or wheel-like configuration with a relatively large radius, substantially larger than the radius of a pool drain which the drain cover is intended to cover, so that the disk extends out over the pool floor or other surface having the drain, radially beyond the drain, the disk carrying beneath it a plurality of evenly spaced radial ribs which define between them channels opening at the periphery; the ribs support the cover on the surface in which the drain is located so that the disk periphery stands off that surface for water flow intake beneath through the side inlets; the ribs and channels control water flow beneath the disk so that water flows relatively evenly in the channels from the periphery and then into the drain without potential for pool user entrapment and substantially without vortex creation.

Abstract: A swimming pool treatment device for simultaneous introduction of at least two separately stored chemicals into the water of a swimming pool has an enclosed, selectively openable first hollow body portion for containing and dispensing a first chemical into the swimming pool water. At least a second enclosed, selectively openable hollow body portion is included for containing and dispensing at least a second chemical into the swimming pool water. The first hollow body portion and the at least a second hollow body portion are selectively detachably interengaged with one another. The first hollow body portion and the at least a second hollow body portion are selectively detachably interengaged with one another, to thereby provide a way to simultaneously introduce at least two separately stored chemicals into the water of the swimming pool.

Abstract: Chemical treatment device, i.e., a chlorinator for use in a swimming pool filtration and circulation system having a skimmer system with a water intake from the pool, a filter for receiving and filtering water intaken, and a pump for returning filtered water to the pool. The device has a vessel of synthetic material with a compartment for treatment chemical, and is provided with an array of break-opens at different levels for opening through from exteriorly of the vessel into the compartment. The device includes an arrangement for locating the vessel to receive flow of water entering the skimmer causing flow to be exposed to the chemical for dissolving it. Interior walls of the compartment diverge downwardly to prevent bridging of the chemical within the compartment. The compartment has a drain for discharging treated water into the skimmer system. Discharging may also take place through the break-opens.