Patent GB-157359-A (GB)
Title: Improvements in automoone internal combustion motors
IPC: F02M1/00
Filed: 1921-01-10
Abstract: 157,359. Bayerische Motoren Werke Akt.-Ges. June 20, 1918, [Convention date]. Spray carburettors.-Engines for automobiles and the like, having an exceptionally large working volume and high ratio of compression, are provided with a multi-chambered carburettor of which the individual chambers may be successively opened and closed by a centrifugal, electric, or other gover. nor to give the most favourable opening for the prevailing number of revolutions, which opening may be manually reduced at will but not increased; the effect of the arrangement being to economize fuel, minimize the use of or dispense with the changespeed gear, and to obtain smooth and silent driving. The carburettor has a by-pass nozzle 26, and carburetting chambers 1, 2, 3 controlled by throttle valves 4, 5, 6, the levers 11, 12, 13 of which are actuated by pins engaging specially spaced slots 8, 9, 10 in a rod 7 and are returned by springs 14, 15, 16. A centrifugal governor 17 driven by the engine and provided with a selfbraking device acts upon the rod 7 through a bellcrank lever arm 17<a>. At the other end of the rod 7 there is a tubular casing 18 relatively to which a rod 20 with stop 23 may slide, the rod being normally pushed as far as possible out of the casing by a spring 22 acting upon plates 19, 21. The rod 20 is jointed and attached to a throttle lever 25. The force of the spring 22 is such as to overcome the resistance of the springs 14, 15, 16 without itself suffering any further compression. In the position shown in Fig. 1, the motor is about to be started, only the nozzle 26 being in action. After starting, the governor will move the lever arm 17<a> to the left, and lever 25 is moved to cause rod 7 to follow and contact with this lever, the spring 22 probably being slightly compressed during this movement owing to the braking effect of the governor. The first throttle 4 is opened and the engine speed increases, the lever arm 17<a> moves still further to the left and is followed by rod 7 owing to the compression in spring 22. If a further increase in speed is required, the lever 25 is moved further forward and the same sequence of movements occurs until eventually the throttle 5 is opened. When the engine is giving its maximum performance the parts are in the positions shown in Fig. 4, spring connections allowing the levers 11, 12 to move without further moving their respective throttle valves. In the act of throttling down, the lever 25 is drawn back as shown in Fig. 5, the arrangement of the slots permitting the valve 6 to close fully and valve 5 partly. The engine speed decreases and the lever 17<a> gradually moves towards the rod 7. If now the vehicle reaches a decline, the lever 17<a> is again removed from rod 7, but if an incline is encountered, the lever arm 17<a> moves towards the right and moves rod 7 to the right against spring 22 allowing the throttles to close, and producing the most favourable air speed through the carburettor. In a modification, the spring 22 is dispensed with, each carburetting chamber being provided with two throttles, one being actuated by the lever 25 and the other by the governor. The above described method of control, which is the reverse of that usually employed, may be combined with means to prevent a maximum speed being exceeded. This may be effected as shown in Fig. 7, where the lever arm 17<a> is actuated through a rack 44, pinion 45, and cam-groove 46. The roller 47 reaches its highest point when the maximum speed has been reached, any further increase resulting in the lowering of the roller and the moving of lever arm 17<a> to the right to close the throttles. Specifications 145,648 and 157,234. are referred to.