Patent ID: 6871832

Claim:
A two position, concrete flow leakage preventing shut-off valve adjustably mounted on a concrete delivery hose, whereby the flow of concrete through the hose can be controlled solely between an open concrete flow condition and a closed concrete flow condition, the valve comprising: an outer substantially rigid casing dimensioned to be disposed completely around the concrete delivery hose; flexible sleeve structure disposed within the casing along an entire inner surface thereof and defining a gas chamber between the casing and the sleeve structure, the concrete delivery hose passing entirely and continuously through the casing and the sleeve and isolating the concrete flow from the casing and the sleeve; a gas port extending through the casing and into the gas chamber whereby pressurized gas can be introduced into the chamber causing the sleeve structure to be forced radially inwardly to constrict and close upon the concrete delivery hose to define the closed concrete flow condition wherein concrete flow from an outlet end of the concrete delivery hose is terminated, and whereby pressurized gas can be exhausted from the chamber by a relief valve connected to and in communication with the gas port for quickly exhausting gas delivered to the gas port causing the sleeve to open upon the concrete delivery hose to define the open concrete flow condition; and an off/on indicator connected to and in communication with the gas port for indicating open and closed concrete flow conditions of the shut-off valve, wherein the casing and the sleeve structure define a tubular cuff assembly which is adjustably suspended upon the concrete delivery hose.