Abstract: A window sash assembly includes a window sash having an upper rail and at least one side rail that form a corner of the window sash. A slot at the window sash corner opens laterally outwardly from the corner and is defined in part by opposed linear tracks on the upper rail. A tilt latch is disposed in the slot, and includes a housing having opposed sidewalls and outwardly extending ledges overlying the sidewalls slidably received over the tracks on the upper rail. A flexible resilient spring element on each sidewall is spaced from the associated ledge such that the tracks on the rails are slidably received between the ledges and the spring elements.

Abstract: A window sash assembly includes a window sash having an upper rail and at least one side rail that form a corner of the window sash. A slot at the window sash corner opens laterally outwardly from the corner and is defined in part by opposed linear tracks on the upper rail. A tilt latch is disposed in the slot, and includes a housing having opposed sidewalls and outwardly extending ledges overlying the sidewalls slidably received over the tracks on the upper rail. A flexible resilient spring element on each sidewall is spaced from the associated ledge such that the tracks on the rails are slidably received between the ledges and the spring elements. The spring elements preferably comprise at least one arcuate spring, most preferably a plurality of arcuate springs, on each sidewall of the housing with concave portions opposed to the ledge. The housing preferably is of molded plastic construction, and the arcuate springs preferably are integrally molded with the housing.

Abstract: The invention provides a process for extracting bitumen from oil sands. The process includes the step of conditioning the oil sands by adding hot water and steam to the oil sands. The conditioned oil sands are then introduced into a separation zone. Separation of the oil sands into a bitumen froth phase, a middlings phase and a tailings phase occurs in the separation zone. Water with air dissolved therein is continuously injected under pressure upwardly through the separation zone. The water is at a low temperature relative to the oil sands. At least two of the phases are then separately withdrawn from the separation zone.

Abstract: The invention provides a process for extracting bitumen from oil sands. The process includes the step of conditioning the oil sands by adding hot water and steam to the oil sands. The conditioned oil sands are then introduced into a separation zone. Separation of the oil sands into a bitumen froth phase, a middlings phase and a tailings phase occurs in the separation zone. Water with air dissolved therein is continuously injected under pressure upwardly through the separation zone. The water is at a low temperature relative to the oil sands. At least two of the phases are then separately withdrawn from the separation zone.

Abstract: Oil containing sludges are treated for the recovery of oil therefrom to render the resultant sludge disposable, by a process of conditioning the sludge to destabilize the emulsified phase thereof, centrifuging the destabilized sludge to obtain a solids-rich material which is largely hydrocarbon free and disposable, and a supernatant, hydrocarbon-containing liquid, and then subjecting the supernatant so formed to liquid/liquid phase separation. The conditioning is conducted so as to prepare a conditioned sludge characterized by a solids content of less than 50% by weight, a water content of less than 90% by weight, an oil phase with an API gravity of less than 12.degree., a continuous aqueous phase, and the solids in the sludge being primarily water wetted, this conditioned sludge being ready for centrifugation.