Patent GB-327435-A (GB)
Title: Improvements relating to dry-pipe fire-extinguishing sprinkler systems
IPC: A62C35/64
Filed: 1928-12-03
Abstract: 327,435. Woosnam, A., (Automatic Sprinkler Co. of America). Dec. 3, 1928, Sprinklers, automatic; sprinkling apparatus, non-automatic.-In a drypipe sprinkling system, the distribution piping is maintained at atmospheric pressure, and the main water valve is opened, upon the fusion of a fusible link in the protected area, through the agency of a pneumatic impulse transmitted through a control piping to a valve operating means. The impulse may be one either of compression or exhaustion. Hand means for generating the impulse may be added, and the impulse may be arranged to open also secondarv valves at the entrance to each section of a sprinkling system. As shown in Fig. 1, the apparatus comprises a water pipe 12, main valve 15, and riser 14 with a plurality of branches 18, 19. Associated with each branch is a control piping 23 or 24 connected to a pipe 22 kept at atmospheric pressure by a small " bleeder " 33. In the branch 19, for example, is a fusible head 63, Fig. 4, which in closed position, holds open a toggle linkage 60, 61 and so expands a bellows 58 against a spring 66. The bellows 58 is in communication with the pipe 24, so that when the head 63 fuses and the bellows collapses, a pneumatic impulse passes through the pipes 24, 22 and expands a normally contracted bellows 36 to open the main valve. The latter, Fig. 2, comprises a valve 29 held to its seat 30 by a pivoted lever 28, an adjustable abutment 56, a lever 52, catch members 48, 54 and a pivoted lever 50. When the bellows 36 expands, it disengages a catch lever 42, allowing a weighted lever 40 to fall upon the lever 50 and disenage the catch-members 48, 54. The valve 29 then opens. In its fully open position, it closes the drip outlet 27 from the valve casing. A hand-operated valve, Fig. 6, may be provided at the entrance to a distributing pipe 19<b> or to a hose pipe 106, Fig. 1. This comprises a valve 68, screw-spindle 71, and hand-wheel 70. A pivoted lever 74 engages at one end between collars 72 on the spindle, so that as the latter is raised the lever tilts until a spring-pulled arm 82 upon.it passes its dead centre. The end 76 of the lever is then forcibly lowered by the spring 80 to collapse a normally expanded bellows 78, and so transmit an impulse to open the main water valve. A further hand control provided on the control pipe 23 comprises a normally expanded bellows 112 and a hand-lever 114 for collapsing it. Where a differential main water valve is employed, Fig. 7 (not shown), the expansion of the bellows 36 is arranged to open a drain valve from the differential chamber. In a modification, Fig, 9, a main valve 15<a> is provided in the water pipe 12<a>, and a secondary valve 116 is provided at the entrance to each distributing section. In this arrangement, a pneumatic impulse generated by an automatic or hand-operated device as previously described opens the particular valve 116 concerned, by means of a bellows 36, and at the same time compresses an expanded bellows 124 to relay the impulse to open the main valve 15<a>. The valves 116 and 15<a> are substantially as described with reference to Fig. 2. The valve 15<a> is operated both by relayed impulses from the valves 116, and direct impulses from a further sprinkling section 126.