GB413630A - Improvements in carburettors - Google Patents

Abstract

413,630. Spray carburetters. WATCHORN, R., 404, West Highland Avenue, Redlands, California, U.S.A.-(Assignees of Jolmston, H. A. ; State Street, Redlands, California, U.S.A.) Oct. 14, 1932, No. 28777. Void [Abridged as open to inspection under Sect. 91 of the Acts, Oct. 16, 1933]. [Class 7 (iii).] In a carburetter, an air stream whirling about an axis of rotation and travelling therealong has fuel injected into it on the line of the axis. A converging spiral passage then forces the air and fuel into spiral rotation from which they pass through a port in a cylindrical throttle valve. Inclined fins 20, Figs. 1 and 5, impart a rotary motion to air sucked through an inlet 16 past a conical valve plug 22 normally held against a seat 15 by a spring 23, the tension of which can be increased, to use the plug as a choke, by displacement of a central rod 25 by a stud 35 on a lever 34 operated by an external lever 31, Fig. 2. Tapering walls 39, 41 constrain the air to swirl in vortex from towards a fuel valve 50 located substantially at the apex of the vortex, the mixture then pursuing a narrowing spiral course between an external spiral wall 61 and an inner cylindrical wall 63 which is cut short at 66 to leave an entrance port 65 to a cylindrical throttle valve 69. The throttle valve 69 is rotatable by an arm 101 to control the port 65 and to its spindle 62 is secured an arm 103, the effective length of which is adjustable by a slide 106 connected at its outer end by a ball and socket joint 109 to an adjustable link 111. The opposite end of the link 111 engages a bell crank lever 118 adapted to raise, against spring pressure, a needle valve 53 which co-operates with the coned end 51 of a fuel nozzle 46. The arm 103 is adjusted angularly on the spindle 62 to determine whether movement of the throttle shall effect rapid or slow opening of the fuel valve. The spiral whirl of the mixture is converted to a helical motion as it passes downwards through the open bottom of the throttle valve into a spherical expansion chamber 85 and a stepped spiral cone member 91, loosely mounted on the spindle 62 and lightly pressed against the entrance 100 to the spherical chamber 85, deflects the whirling mixture outwards, whereupon the lower half of the chamber 85 contracts it again before passing it to the port 86 of the induction manifold, the arrangement ensuring thorough vaporization and mixing. In a modification, a choke valve 168, Fig. 9, normally closes the entrance to helical passages 140 leading to a mixing chamber 142, the walls of which first diverge and then converge to form a conical seat 146 for a throttle valve 154 in the form of a double cone. The upper cone 153 of the valve 154 confines the whirling air and directs it past a fuel nozzle 180 to the space between the raised valve 154 and the seat 146, where it acquires a vortex motion which continues into the engine cylinder.