Abstract: A positive buoyancy programmed motion pool cleaning device is adapted for operation under a floating pool cover. The pool cleaning device is given positive buoyancy with floats fore and aft, both floats being adapted to provide positive buoyancy towards the pool cover while riding on an upper water bearing against the under surface of the pool cover. In this adaptation each float defines a concavity having a circumscribing annulus. At the interior of the concavity there is an outlet of a high volume, low pressure jet pump. Typically the high volume, low pressure jet pump includes a low volume, high pressure jet entraining and expanding water flow from beneath the floats through and elongate tube up, to, and discharging within the concavity. Preferably, the concavity and pump outlet are arranged with the pump outlet somewhat off center of the annulus walls so that pool cover plugging of the pump outlet does not occur. In operation, the concavity forms a water bearing pressure pocket.

Abstract: A positive buoyancy programmed motion pool cleaning device is adapted for rolling operation under a floating pool cover so that encountered cover discontinuities such as folds, borders and tears do not interrupt and stop the operation of the device. The pool cleaning device is of the type that has two positive buoyancy portions, these portions typically being positioned fore and aft. At least one and preferably two inverted casters are utilized, the casters each preferably becoming the positive buoyancy portion of the cleaning device. Overall positive buoyancy of the cleaning device causes the caster to ride on the overlying cover at the cover pool interface. The caster is provided with a fairing to reduce drag. A ramp at the leading end of the caster on the upward edge of the inverted fairing allows encountered cover discontinuities to pass smoothly over the fairing to the upwardly exposed caster.

Abstract: A positive buoyancy programmed motion pool cleaning device is adapted for rolling operation under a floating pool cover so that encountered cover discontinuities such as folds, borders and tears do not interrupt and stop the operation of the device. The pool cleaning device is of the type that has two positive buoyancy portions, these portions typically being positioned fore and aft. At least one and preferably two inverted casters are utilized, the casters each preferably becoming the positive buoyancy portion of the cleaning device. Overall positive buoyancy of the cleaning device causes the caster to ride on the overlying cover at the cover pool interface. The caster is provided with a fairing to reduce drag. A ramp at the leading end of the caster on the upward edge of the inverted fairing allows encountered cover discontinuities to pass smoothly over the fairing to the upwardly exposed caster.

Abstract: An improved water-level control method and apparatus automatically maintains the water level in a pool by selectively filling or draining water as required during the period that the circulating system is not operating.