Abstract: A blast head has an air cushion device that directs a flow of relatively high velocity air inwardly and toward the surface being blasted from around the periphery of the blast head. This air flow creates a barrier preventing the escape of particles and debris from the blast head and also creates a so-called ground effect; i.e. the air flow between the head and the surface creates a force that lifts the head off the surface being blasted so that the head floats on cushion of air.

Abstract: In a blast head for a vacuum blasting operation, abrasive particles in a stream of compressed air are directed against a work surface and removed by vacuum. Ambient air is directed into the blast head upstream of the work surface to reduce frictional forces between the blast head and the work surface due to the vacuum. The ambient air is admitted through a one-way spring biased valve. The flow of ambient air into the blast head is controllable by adjusting the spring force in the valve.

Abstract: A blast head for a vacuum-blasting machine has a deflecting surface oriented at an angle to the direction in which particles under pressure are sent through the blast head. The blast head has an inner, blast jacket, an outer, vacuum jacket, and a blast head body connected to the vacuum jacket by a flexible bellows. The blast head body is secured to the blast jacket to permit axial movement of the blast jacket relative to the vacuum jacket.

Abstract: A vacuum blasting machine with a sealed waste transfer system has a collapsible sleeve that provides a containment interface between the waste chamber and the waste collection drum. The periphery of one end of the sleeve is secured around the periphery of the opening in the waste collection drum. In the transfer operation, the other end of the sleeve is pulled over the dump housing, providing an impervious containment barrier between the dump housing and the interior of the collection drum. The drum has a vent opening with a bushing to which a vent line is attached. A vent line connects the collection drum to the interior of the waste chamber via a valve.

Abstract: A vacuum blasting machine with a sealed waste transfer system has a collapsible sleeve that provides a containment interface between the waste chamber and the waste collection drum. The periphery of one end of the sleeve is secured around the periphery of the opening in the waste collection drum. In the transfer operation, the other end of the sleeve is pulled over the dump housing, providing an impervious containment barrier between the dump housing and the interior of the collection drum. The drum has a vent opening with a bushing to which a vent line is attached. A vent line connects the collection drum to the interior of the waste chamber via a valve.