418,972. Spray carburetters; induction pipes. SEIDEL, A., 9, Kaiserdamm, Charlottenburg, Berlin. Jan. 31, 1933, No. 37058. [Classes 7 (ii) and 7 (iii).] A carburetter has two or more choke tubes arranged in series, one of the tubes being controlled at its narrowest cross-section by a throttle or cut off valve comprising a pair of relatively movable flat plates having registering apertures. One of the choke tubes is provided with peripheral inlets for a fuel-air mixture, which is admitted to the main air stream. The rich mixture is formed by drawing air from a tube 29, Fig. 1, over a nozzle 28 supplying heavy fuel and it issues through an annular channel 30 and slits 31 into a main air stream which traverses a choke tube 3, controlled by a plate valve 19, 20. Openings 23, 25, in the valve, Fig. 10 register with the choke tube 3 the valve being actuated by a lever 14 having rollers 15, 16 which engage apertures 17, 18 in the plates 19, 20. During idling, the choke tube is closed and mixture, obtained by drawing air through a tube 9, Fig. 1, over a light-fuel nozzle 10, is supplied through an annular channel 11 and slits 12 to the mixing chamber or induction pipe, when the choke tube is opened. The idling mixture is suppressed by admitting air to the tube 9 through registering openings 32, 33, Fig. 10 in the plate valve. Below the choke tube 3 the induction pipe branches into a number of conduits 5, 6, 7, Fig. 1, preferably made from drawn copper tubes, which pass through an exhaust- or water-heated jacket 42. The conduits are long and of small cross-section; they impart a high velocity to the mixture, and fuel deposited on their walls is drawn from annular spaces 39, 40 surrounding Venturi tubes 35, 36 into the mixture stream. The Venturi tubes also damp out oscillations set up in the mixture stream when the inlet valve closes. A further Venturi tube is inserted in each member 38, by which a conduit is connected to the engine cylinder. If a large nozzle 10 is used additional air may be supplied during idling, through an opening 43, Fig. 10, in the plate valve and as the choke tube is opened the port 43 is first closed and then brought into register with the ports 32, 33 to suppress the idling mixture. In the modified construction shown in Figs. 4, 6 and 13, a rich fuel-air mixture is supplied to two choke tubes 3<1>, 3<11> located in separate conduits each branching into two passages 5<1>, 7<1> and 5<11>, 7<11> containing Venturi tubes 35<1>, 35<11> controlled by openings 23<1>, 25<1>, 23<11>, 25<11> in sliding plates 19, 20 ; openings 32<1>, 33<1> therein control an air channel 34 leading into an idling passage 9 which discharges through channels 9<1> into the conduits 5<1>, 7<1>. As the throttle lever 14 is operated, the ports 23<1>, 25<1>, 32<1>, 33<1>, 23<11>, 25<11> register in succession to open the choke tubes 35', the channel 34 which suppresses the idling mixture and the choke tubes 35<11>. A single nozzle 28 supplies heavy fuel to the two choke tubes 33<1> through a passage 29 and to a branch passage 46 containing a Venturi tube 47. When all the choke tubes 35<1>, 35<11> are open the mixture flows equally through the passages 29, 46, to the choke tubes 3<1>, 3<11> ; when, however, the choke tubes 35', 35<11> are closed, air is drawn through the choke tube 3<1> and the Venturi 47 into the channel 29 to compensate for an otherwise excessive flow from the nozzle 28. Air may be admitted to the channel 29 past a valve 53, and a valve 45 is provided to enable either light or heavy fuels or a mixture of both fuels to be used. When the float chambers 1, 2 are located at different levels, a conduit 50, connected to the channel 34 maintains a slight vacuum in the channel 48 so that a light fuel-air mixture is always available. In modifications (1) to produce a smooth transition when the choke tubes 35<11> are opened, the idling mixture is delivered to the conduits 5<11>, 7<11> as well as to the conduits 5<1>, 71; the passages leading to the conduits 5<1>, 7<1> are larger than those leading to the conduits 5<11>, 7<11>, so that during idling the larger part of this light fuel-air mixture is delivered to the conduits 5<1>, 7<1>. When the choke tubes 5<11>, 7" are opened, a channel controlled by apertures in the plates 19, 20 supplies air to the idling passage leading to the conduits 5<1> 7<1> so that the light fuel air mixture is equally distributed in the conduits 5<1>, 5<11>, 7<1>, 7" (2) the final choke tubes in the conduits 5<1>, 7<1> are omitted (3) the choke tubes 3, 3<1> instead of the choke tubes 35', 35<11> are controlled by the plates 19, 20 and (4) the construction shown in Fig. 1, has choke tubes 35 instead of the choke tubes controlled by the plates 19, 20. In the construction shown in Fig. 18, mixture is supplied during idling through a passage 3009' controlled by the plates 19, 20; as the plates are moved, the choke tube 3<1> is first opened, then, at or just before the opening of the choke tube 3" the conduit 3009<11> connected to the idling passage 9 is opened and, finally, when the choke tubes 3<1>, 3<11>, 3<111> are opened the idling mixture is distributed equally through the conduits 3009<1>, 3009<11>, 3009<111> into the conduits 159', 159<11>, 159<111>. The sum of the cross-sections of the conduits 159<1>, 159<11>, 159<111> is equal to or greater than the cross-section of the conduit 59 into which they discharge. The conduit 59 branches into conduits 59a, 59b, Fig. 20, and 59<c> 59d opening into channels 2059, 3059 leading to the valve chambers E<1> .... E<4> of a four cylinder engine, and the cross-section of the channels 2059 or 3059 is equal to the sum of the cross-sections of the channels 59a, 59b or 59c, 59d. The cylinders are also supplied from a larger conduit 54, Fig. 18 fed from a benzene carburetter 200, and controlled by throttles 158, 57, 58, the latter being connected together by toothed segments 57', 58<1>. In the construction shown in Fig. 21, the choke tubes 3<1>, 3" are opened in succession by the slide valve, and for maximum speed, a rotary valve 5000, normally held closed by a spring, is opened to connect a choke tube 3<111> through induction conduits 5059a, 5059b, 5059<c> to the inlet chambers E', E<2>, E<3> of a sixcylinder engine. When the valve 5000 is open, the choke tube 3<111> is fed with rich mixture from the channel 29 through a conduit 529, and when the valve is closed air is supplied from the choke tube 3<111> through the conduit 529, which contains a Venturi tube 547, to the channel 29. In a further modified construction Figs. 24 and 25, an excessive output of the light and heavy fuel nozzles 28, 44 is compensated during normal operation, by air admitted through a channel 650. A piston 653 having a bore 652 moves in the channel 650 and is connected through a bell-crank lever 654 and levers 656, 657 with a ring 658 having openings 660 which control channels 661 arranged annularly about the induction pipe 59 at the end adjacent the valve chambers. To obtain the maximum output the lever 654 is operated to move the piston 653 in the channel 650 ; thus cuts off the air supply and the channel 29 supplies an enriched mixture. Simultaneously, the lever 654 moves the ring 658 to admit air through an opening 663 and a conduit 662 into the valve chamber. The openings 660 may communicate with an annular groove 664 or they may open into the valve chamber separately.