GB833056A - Device for the controlled discharge of compressed fluid - Google Patents

Abstract

833,056. Fire extinguishers. SPARKLETS Ltd. May 21, 1958 [May 22, 1957], No. 16260/57. Class 47 [Also in Groups XXVIII, XXIX and XXXIV] A valve used for inflating tyres &c. or in a fire extinguisher has a housing which consists of threaded parts 10, 11, Fig. 2, is screwed into the neck of a cylinder 13 containing compressed fluid, such as carbon dioxide, air or nitrogen; the housing has a stepped bore in which is disposed the hollow stem 20 of a lift valve closure 21 embodying an annular resilient body that co-operates with a seat 23 on the inner end of the housing to close off the cylinder from the latter. The closure 21 is urged on to its seat 23 by a spring 32 and the pressure of the fluid in the cylinder. A filter 16 prevents the passage of any foreign matter from the cylinder to the valve. The upper end of the stem 20 is arranged to engage an annular resilient seal 40 disposed at the end of a piston 41 slidable in housing part 11, the piston having a bore 42 that opens into a portion 43 of increased diameter and against the end of which abuts an annular member 44 of silicon or natural rubber or similar resilient material that is held in place by a flanged sleeve 45 slidable over the piston 41, the sleeve incorporating a port 49. A bracket 48 clamped between the parts 10, 11 is formed with eyes 50 for the two ends of a looped operating lever 51, Fig. 3, the bracket also supporting a bolt 53, Fig. 2, which serves to prevent rotation of the sleeve 45 and to limit its outward travel; the bolt 53 also serves to anchor one end of a chain, the other end of which is secured to a Venturi nozzle 58. Lugs 59 are provided on the sleeve 45. The valve actuating mechanism may be removed without unseating the closure 21. When the apparatus is not in use the lever 51 is swung over the sleeve 45 and sprung over a washer 47 into the position shown in full lines until its lower portion contacts the cylinder 13 and its horizontal upper portion bears against protrusions 60, Fig. 3, on the under side of the lugs 59 so that any force applied to the end of the sleeve 45 caused by dropping the apparatus for example, causes the two sides of the lever 51 to be squeezed together so that the lever cannot spring over the washer 47. To inflate a tyre the lever 51, Fig. 2, is swung into the chain dotted position, the member 44 is pushed on to the tyre nipple and the lever is squeezed towards the cylinder 13 whereupon the sleeve 45 is caused to slide over the piston 41 first compressing the member 44 so that it grips the nipple and then moving the sleeve and piston as a unit until the seal 40 abuts the stem 20 and unseats the closure 21 so allowing the compressed fluid to enter the tyre via cross bores 36 and the interior of the stem 20 and the piston bore 42; the lever 51 is released when the desired tyre pressure obtains. If there is a blockage in the nipple the pressure builds up in portion 43 and the piston 41 and member 44 will be forced apart to allow the gas to escape through the port 49. When used as a fire extinguisher the venturi nozzle 58 is inserted in the member 44. The apparatus may also be used for inflating rubber dinghies, mattresses, footballs or for pressurizing fluid dispensers. The cylinder 13 is covered by a sleeve 61, Fig. 3, of low thermal conductivity.