US2156104A - Vacuum fuel feed device - Google Patents

Description

paf'g, w39; A F. BARFQQ f 35593941 VACUUM FUEL DEVICE Filed Jn. 9, 1935 A 2 Sheevhcz't l I INVENTOR. TQEDEIUK AQFOD @Mgg TORNEY Z55, @3%. F', BARFQD Y. I VAGUUMHFUEL, 'FEED DEVICE Filed Jan. 9, 1955 INVENTOR; fDAQFoD BY @l c vTZEDERIK A TTORNEY.

.35 of Figure 1;

Patentedv 25, l1939 vVACUUM FUEL FEED Davies Frederik Barfod, South Bend, Ind., alsignor to -Bendix Products Corporation, South Bend, Ind.,

a corporation of Indiana AApplication January 9, 1935, serial No. .1,035

ZCIaims.

This invention relates to carburetors and more particularly to carburetors of the fuel lift type, which draw fuel from a supply tank positioned at a lower level than the fuel nozzle of the carbu- ,retor.r This application represents improvements in the carburetor disclosed in Milton E. Chandler Patent 2,051,820, issued August 25, 1936.

. An object of this invention is to provide an yimproved carbureting device which will lift fuel from the supply tank to a chamber positioned above the fuel nozzle of the carburetor, and sup- -ply the carburetor with fuel at constant pressure.

A further object is to provide an improved carbureting unit of simplified construction which l5 will eliminate the fuel pump orvacuum tank or# 'dinarily used therewith.

A still further object is to provide an improved fuel lii't carburetor of simplified construction, which may be economically manufactured and will be economical' and positive in operation.

Other objects and advantages of the invention will be apparent from the following detailed description, and from the illustrative embodiments of the invention in the accompanying drawings,

which are submitted merely for purposes of illustration, and are not intended to define the scope of the invention, reference being had for that purpose to' the appended claims.

, In the drawings wherein similar reference characters refer to similar parts throughout the several views:

Figure l is a vertical section illustrating apreferred embodiment of the invention;

. Figure 2 is a sectional view taken on line 2--2 Figure 3 is a sectional view taken on the line 6-6 of Figure 1;V

Figure 4 is a sectionalview taken on the'line 4-4' of Figure l; Figure 5 is an enlarged sectional view of the suction venturi;

Figure 6 is van enlarged sectional view of a suction valve;

Figure '7 is an enlarged sectional view showing a modified arrangement of the 'suction venturi and pressure responsive valve; and

Figure 8 is a diagrammatic view showingthe fuel passages disclosed in Figures 1 to 5.

Referringmore particularly tothe drawings, there is shown a carbureting unit having an upper or airhorn section III, a middle or body section i2 and a throttle body section I4, The upper and middle body sections are preferably formed of zinc or similar material suitable for die-casting.

' while the throttlebody section is preferably a sand casting. An air cleaner I6, of known construction, is flxed to airhorn I0 in the usual relation. vThe induction passage formed by .airhorn 00 I6 divides at section I2 into two parallel barrels in vacuum line 16 from chamber 54,.

(cl. loa-zas) u each of which supplies fuelfto s plurality of engine cylinders.

The flow of air through airhorn I6 is controlled by a choke valve I6 mounted on a shaft I6 and provided with a spring pressed poppet valve 26 to 5 permit a small amount of air to pass through airhorn I0 .when the suction is great enough to compress spring 22. 'I'he choke valve may be manulally controlled or may, beautomatically controlled by means such as' those disclosed in S. F. 1 Hunt Patent 2,031,709, issued February 25, 1936. Fuel is supplied to the carburetor from float chamber 24, through appair oi' fuel ducts 26 each of which terminates in a'fuel discharge nozzle 26 positioned to discharge at the most restricted 15 portion of a primary venturi 30 which in turn discharges at the most restricted portion of a secondary venturi 32. 'I'he venturis 66 and 62 are carried in middle body section kI2 and are preferably formed integral therewith. The lower 20 end of secondary venturi 32 is a slip ilt in the upper portion of barrel 34 formed in the throttle body section I4. 'I'he now of mixture through each of thecarbureting passages thus formed by the three described sections is controlled by a 25 throttle valve 36 mounted on a shaft 5 6 Journalled in thewalls of the throttle body section I4.

A ange .40 formed integral with the airhorn section I0 provides a. cover for float chamber 24 and accommodatesl a needle valve 42 which when 30 actuated by lever 44, ilxed to float 46 and pivoted at 48, controls -the flow of fuel into said oat chamber and maintains a constant level therein. The upper portion of flange 45 has a recess which cooperates with a correspondingV recess in the 35 lower portion of a superposed tank section 55 to vpivotally mounted by two-,arms 51 ilxed to the float and pivoted to the lower ends of two downwardly extending studs'". An arm 64 fixed to iloat 56 connects by means ofa spring 66 with a 45 shifting member 60 which has two parallel arms the lower ends of which are slotted. and pivoted at 16 to the lower ends of two studs 61. A float actuated slide valve 66 is slidably mounted in studs 19 and operates-to selectively admit atmospheric 5o pressure to chamber 54 through a chamber 66 which communicates -through anapertured felt pad 55, with the air cleaner I6.` A second slide` valve 62 operates to selectively cut oi! the vacuum member 60 connects with slide valves 66 and 62 in such a manner as to move the valves fromone of their extreme positions tothe other when the spring 66 is moved past the dead'centenformed by a pin 16. by mcvementof floot 56. As floot 60 Shifting 5s 58 rises, arm 84 rises also, moving spring 88 past pin 18 and causing shifting member 80 to exert an upward force on slide valves 88 and -62 which will vmove the valve upwardly, thereby opening passage 10 and closing vacuum line 16 to allow air to enter chamber 54 from the air cleaner. 'I'he pressure existing in the upper portion of chamber 54 will immediately rise to atmospheric, and fuel will flow out of said chamber through outlet member 58. As the fuel `level in chamber 54 drops, float 58 will rotate in a counterclockwise direction (Figures 2 and 3) around its pivot, thereby carrying arm 84 downwardly. As spring 66 passes the dead center at`16, it will cause lever 80 to rotate in the clockwise direction and exert a downward pull on slide valves 68 `and 82, closing air inlet passage 10 and opening port 14 and vacuum line 16 leading to the suction venturis 80 and 82, which will exert suction inv chamber 54 and draw fuel from supply tank 84 to chamber 54 through duct 86 while at the same time holding valve member |06 to its seat to prevent flow of 36. An unbalanced butterfly valve 84 is mounted on a shaft 88 in each barrel 34 between the inlets 83 and outlets 85 for the purpose of insuring a predetermined minimum suction in venturi 82, sothat sufficient air will be forced to ow therethrough, even at wide open throttle, to lift fuel from storage tank 84 to chamber 54S Each valve 84 is provided, at-its greater portion, with a bent lip 85 provided with a lug 61 which holds the valve from fully closing. An ad- Justable coiled spring 38 yieldingly urges valves 84 to the closed position. 'Ihis construction has been found to prevent iluttering, and the dragof lips 85 moves the valves to a very nearly open4 .position when the engine is operating at high speed and open throttle. Fuel for idling purposes is supplied through the conventional idling passages |02 and |04.

A sleeve valve 88 is loosely mounted in an enlarged bore 81 formed in vacu'um line 16, and is normally held in its uppermost position by a spring 9 I, in which position its notched upper end permits free'iiow of air past the valve. When the vacuum exceeds a predetermined value, however. it draws the valve 68 against the bottom of bore 81, so that the flow of air is restricted to an orice 83 formed in a plug in the valve, as shown. This construction limits the maximum suction which can be applied to chamber 54, and thus prevents fuel in liquid or vapor form from being drawn through the line 18.

Figure 7 illustrates an arrangement wherein v Aber preferably of i," throat diameter and having an entrance angle of 20, whereas the dis- A charge angle of the venturi is 6. The annular suction entrance |08 of the primary venturi is preferably The operation of the device thus far described is as follows. It is apparent from theforegoing'k description that irrespective ofthe position of throttle valves 36 sufficient -suction will at all times be present in the throat of primary venturi 80 to lift fuel from supply tank 84 to upper chamber-54. When the fuel lever in chamber 54 is at its highest point, 4represented by the line Y-Y in Figures 1 and 3, slide valve 88 will be in the position shown in Figures 2 and 3, in which position it permits air to enter through passage 10 and opening port 14 to permit the suction developed at venturi 80 to be transmitted to the chamber 54. The suction draws valve member |08 tightly to its seat, and draws fuel from the supply tank 84 to chamber 54, thus gradually raising the fuel level therein. Float 58 is moved upwardly by the rising fuel level, and when it approaches the position shown in Figures 2 and 3, the spring 66 will b e moved upwardly past dead center 18, and will thus overcome the resistance of valves 68 and 62 and move them upwardly, thereby closing port 14 leading to thel suction venturis and opening passage 10 to restore the pressure in chamber 54 to atmospheric. weight of the fuel being now augmented by atmospheric pressure, will thereupon force valve member |08 from its seat and the fuel will flow to reservoir 52, as before described, and the cycle will then be repeated.

I claim:

1. In a device of the class described, a variable level fuel chamber, a source of fuel communicating with the chamber below the lowest fuel level thereof, a source ofsuction, passages connecting said chamber with saidsource of suction and with atmosphere, valves in said passages, a float piv- Thev otally mounted in said chamber, and mechanism connecting said float with said valves comprising an oscillating member pivoted at one end and Ahaving its free end connected tothe valves, a

movable member fixed to the float and movable to opposite sides of the piv'ot of said oscillating member, and a tension spring connecting the movable member to the free end of thev oscillating member.

2. In a device of the class described: a variable level fuel chamber; a source of fuel communicating with the chamber; a source vof suction; passages connecting said chamber with said source of suction and with atmosphere; parallel valves in said passages so designedfthat when both are moved in the same direction one will close vand the other will open; a oat Vpivotally mounted within said chamber and mechanism connecting 'said oat with said valves comprising an oscillati member pivoted at one end and having its Ie end` connected to the valves, an arm fixed to thre float and projecting therefrom to the vicinity of the pivoted end of the oscillating member. and a tension spring connecting said.y arm to the free end of the oscillating member.

FREDERIK Bannon.

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