Abstract: A fire protection system for a clean room semiconductor fabrication facility involves the use of a low pressure carbon dioxide source and a discharge system to extinguish fires detected in or near the tools. Each tool is plumbed with dedicated carbon dioxide suppression agent discharge plumbing. The system individually monitors each tool for fire, preferably using infrared radiation sensors and linear heat detection cable. A remote control panel responsive to the fire detectors controls the discharge of carbon dioxide suppression agent unless there is operator intervention. A user interface at or near the respective tool includes various manually actuated controls to override the automatic operation of the fire protection system, and therefore allow a supervisor to eliminate or at least minimize the amount of clean up, repairs and downtime associated with the discharge of carbon dioxide suppression agent in case of a false alarm. The components of the fire protection system (e.g.

Abstract: An improved recessed sprinkler head including a frame having a base portion with an outlet to be connected to a source of water under pressure. The frame also includes a pair of curved arms which extend outwardly from the base portion and are connected together at a junction. The outlet is normally enclosed by a cap which is retained in position by a releasable mechanism that includes an element arranged to release when the sprinkler head is exposed to a predetermined elevated temperature. A disc-like support member having a central aperture of sufficient size to receive the arms of the frame is slipped upwardly over the frame after the sprinkler head is connected to the water line, and the support member includes a pair of opposed flexible resilient tabs that are adapted to engage an abutment on the base portion of the frame. An annular sleeve is positioned outwardly of the frame, and the lower end of the sleeve defines a decorative ring.

Abstract: A liquid flow indicator for use in an automatic sprinkler system. The indicator is adapted to be attached to a water line and includes a non-metallic vane retainer or support which is mounted within an opening in the water line. A flexible one-piece plastic vane is pivoted to the retainer and has a generally circular body portion which is disposed transversely within the pipe. If the water line is opened downstream of the indicator, the flow of water within the line will pivot the vane, causing a magnet in the upper end of the vane to move into proximity with a sensor to complete an electrical circuit and generate a signal indicating that the water line has been opened. The retainer is formed with a pair of aligned recesses which are sealed apart by a central wall and the upper head of the vane which contains the magnet, is located in one recess, while the sensor is in the other recess.

Abstract: An improved concealed sprinkler head for an automatic sprinkler system. The sprinkler head includes an orifice body that is mounted above the ceiling of the building and is connected to the water line. The body has an outlet which is normally closed by a valve cap, and the cap is held in the closed position by a lever assembly which includes a lever and a leaf spring. The lever has a pair of parallel spaced arms and a tube, which houses a fusible metallic element, extends between the arms. Balls are located within the ends of the tube on either side of the fusible element and impressed into the ends of the element, and the balls are engaged with sockets in the arms. One end of the lever is engaged with an abutment on the valve body and the opposite end of the lever is engaged with the leaf spring which is fulcrummed on the abutment. The leaf spring bears against the tube and urges the tube in a downward direction.

Abstract: An improved concealed sprinkler head for an automatic sprinkler system. The sprinkler head includes an orifice body that is mounted above the ceiling of the building and is connected to the water line. The body has an outlet which is normally enclosed by a valve cap, and the cap is held in the closed position by a latch assembly which includes a latch bar. One end of the latch bar is provided with a projection which engages an abutment on the orifice body while the opposite end of the latch bar is provided with a recess which contains a fusible metallic element, and a movable member, such as a ball or a series of balls, is engaged with the fusible element and projects outwardly from the latch bar and is engaged with a second abutment on the orifice body. The latch bar carries a decorative plate that is mounted flush against the ceiling and has a series of openings to provide improved heat transfer to the fusible element.