Abstract: An activator assembly for an automatic sprinkler head having a fluid flow control valve comprising releasable lever means serving to hold the valve closed, and a control assembly including a fusible element, heat conductive fin means and a retaining ring all mounted upon an axial post, the lever means abutting the retaining ring and being released by axial displacement of the retaining ring when the fusible element responds to a predetermined temperature.

Abstract: A concealing housing for a ceiling-mounted fire sprinkler head in which a bottom cap is automatically released to uncover the sprinkler head in the advent of a fire, the housing comprising a body supported by the sprinkler head, and a plurality of connecting studs to hold the cap to the body, each stud being of sheet metal and being releasably connected at a foot portion by low-temperature solder to the cap and threaded by a head portion through a hole in the body until an intermediate shoulder on the stud engages the body said stud being bent over at its head portion for retention upon the body.

Abstract: A supervisory alarm accessory for a fire sprinkler stop valve of the type including a rotatable valve actuator driving a valve spindle. The accessory contains an adaptor sleeve connectable between the actuator and the spindle to rotate with the actuator. The adaptor sleeve has an externally threaded part, and a fixed housing supported on the sleeve to permit relative rotation of the sleeve and enclosing the threaded part. A follower is threadably engaged with the threaded part and keyed to the housing. An alarm generator, and activating arrangement are supported on the housing and provide an activating connection between the alarm generator and the follower to initiate an alarm.

Abstract: A valve for sealing closed the fluid supply orifice in a sprinkler head body, comprising a sealing plug having a projection extending axially towards the supply orifice when assembled on the body, a resilient membrane having an annular portion captured over the projection and for compression between the plug and the body to seal the supply orifice, and a tail portion attachable to the body, whereby upon jettisoning of the plug with opening of the supply orifice the plug remains attached to the body by the tail portion at least until the plug is clear of the fluid jet issuing from the orifice.