Abstract: An actuator for use with a negative pressure fire suppression sprinkler system is disclosed. The actuator has three chambers, each chamber having a flexible diaphragm. One chamber is connected to the sprinkler system piping network. Its diaphragm moves in response to an increase in pressure in the piping network signaling a fire. The diaphragm in the second chamber opens an orifice in response to the motion of the first diaphragm. The open orifice allows water to flow from the third chamber to the ambient. The diaphragm in the third chamber moves in response to the water flow from the third chamber. The third chamber is connected to a valve controlling water flow to the piping network. Motion of the diaphragm in the third chamber actuates the valve, releasing water to the system.

Abstract: A grinding tool accessory for containing and removing dust formed by a grinding disk comprises: a flexible housing adapted for mounting on the grinding tool and defining a first chamber for collecting the dust prior to removal, the housing having an edge spaced from an outer perimeter of the grinding disk and defining an annular gap; the housing having an outlet adapted for connection to a source of vacuum and a dust collector; a brush extending from the edge and together with the grinding disk defining a second chamber, the brush having bristles with different lengths dimensionally related to the gap, dust being drawn from the second chamber into the first chamber through the gap and thereafter into the dust collector by the vacuum; and, the housing having at least one sealable hole to adjust the vacuum for optimizing containment and collection of the dust as the grinding tool is moved over flat and contoured portions of a work surface.