GB266257A - Improvements in ventilators - Google Patents

Abstract

266,257. Nelson, F. N. Nov. 5, 1926. Ventilating-shaft tops.-A ventilator, more particularly for ships, comprises an air tube 2, Fig. 2, having an out-turned peripheral flange 5 at its upper end, a hood 11 supported above the upper end of the tube, a ring 6 fixed about the tube in spaced relation to the said flange 5, guiderods 8 fixed between the ring 6 and flange 5, and a float 14 encircling the tube and slidable on the guide-rods. The float 14 which is adapted to be lifted so as to abut against the flange 5 and hood 11, consists of a hollow annular ring and the rods 8 pass through openings formed in flanges 15 and ring 16 provided in the float. Gaskets 17, 19, on the hood and float respectively, make contact with a flange 14<1> on the float and flange 5 of the tube. When the ventilator is applied to a ship of small type, a weight in the form of a ring 20, slidable on the rods 8, is provided in order to close the float against the hood should the ship be capsized. A cowl casing consisting of the frusto-conical members 30, 31 surrounds the hood and upper portion of the tube, but such casing may be omitted and the valve is then operated by mechanical means only. The lower part of the casing is provided with a number of parts 32, normally closed by trap doors 33 mounted on hinges 34. The upper and lower edges of the doors overlap respectively the inner and outer faces of the casing so that the doors serve to discharge any large amount of water which may enter through the cowl 24. A drain pipe 38 is also provided in the casing. Mechanical means for lifting the float consists of lazy tongs 53 connected with the float by rods 50 and adapted to be operated by means of handles 58 on a shaft 54 as shown in Fig. 1. The shaft 54 may be operated from the bridge of a vessel by means of a motor and chain or cable. An alternative method of lifting the floats is by pivoted levers engaging the float and operable by chains passing over sprocket wheels or drums. The cowl 24 is adapted to be rotated by suitable gearing 25 - - 27. A pivoted cover plate 41 covers an opening in the tube 2, for the insertion of a fire hose.