US1923473A

US1923473A - Downdraft carburetor

Info

Publication number: US1923473A
Application number: US467494A
Authority: US
Inventors: Beard Bert
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-07-12
Filing date: 1930-07-12
Publication date: 1933-08-22
Anticipated expiration: 1950-08-22

Description

Aug. 22, 1933. B. BEARD DOWNDRAFT CARBURETOR Original Filed July 12, 1950 INVENTOR. BERT Bram).

BY M W ATTORNEY.

Patented Aug. 22, 19 33 I v A I I UNITED STATES: PATENT orrics Q DOWNDRAFT caanu mtroa Bert Beard, Detroit, Mich, assignor to George Mpliollity, Detroit, Mich. 1

,Application July 12, 1930. serial No. 461,494,

Renewed November 9, 1932' 8 Claims. (01. 251-34) This invention relates to a downdraft carbu- 2, line 28-31. An idling and low speed fuel ar-' 'retor having a high speed fuel nozzle combined rangement Y-Z is of a well known typ as with an air vented compensating nozzle. shown connected to the annular chamber W The specific object of this invention is toapthrough the restricted passage X, but as this is 5 ply an accelerating pump to-the air vented comnot part of this invention its specific details need pensating nozzle, and a constant gravity head notbe described. 1 p to the high speed fuel nozzle. 8 l v Fig. 2 shows a modificationof the construc- In the figures all-the essential parts of theintion shown in Fig. 1 with the valve N located vention are arranged on one plane so as to sim-' outside of the pump cylinder B and in the float plify the description. g I chamber-A. An arm vV attached as a bracket Fig. 1 shows the preferred construction. p to the arm U is arranged to engage with the up! 2 shows a modification of Fig. 1.- per endof the valveNwhen the throttle is opened In the figures A is the float chamber containwide. n ing the usual float mechanism which is no part Operation.

of this invention, B is the pump cylinder 10- l I cated wholly within the float chamber, C is the When the engine is idling on the low speed guiding portion of a piston which consists of passages XY--.Z. the check valve F is in the the parts C, D, E and F. B being the piston position shown, that it is suspended on the step proper which comes in contact with the fuel. on the extension-C, and fuel thus freely passes This piston D is carried on C! which is an exfrom A through G into the piston cylinder B, tension from C. A spring Eseparates the part as the check valve F leaves the perforation in C from D. The piston D is perforated, and the D open- When the throttle is opened the fuel in perforation is. closed by an annular check valve B acting on the check valve F raises it against the F. This'check valve F is carried on a step on perforated piston D thus closing this perforation 5 the extension C. The fuel entrance to the cyland'trapping the fuel in the cylinder B, which inder B is through the opening G located betherefore is forced through H into the perforated low the level in the fioat chamber A. The fuel passage J. The fuel discharges from J into the outlet from the cylinder B is through the reannular passage K and so into the throat of stricted orifice H, then through the perforated the venturi P. Normally air enters about V and o tube J to the annular nozzle'K. In the center fiows into the annular chamber W which surof the annular nozzle K an air passage M is rounds J, and this air enters through the per provided for still further a.tomizing the fuel. foration and thus mingles with the fuel therein. In the bottom of the cylinder 13 a valve N is lo-- When the throttle is open beyond half way that cated, which is adapted to engage with the ex-. is to say at speeds corresponding to 55 miles 35 tension C. Whenthe piston descends this valve per hour, C the extension "from the piston C N is opened and so admits fuel to a passage 0 engages with the valve N, then the fuel is forced which discharges into the throat of a Venturi up 0 as well as through J. This fuel discharges tube P, into the throat of which the annular at 0 below the level in the float chamber A. nozzle K also discharges. It will be noted that Hence-if the throttle is held wide open on a hill 46 the passage 0 discharges into P morethan A? for example, and the engine speed drops so that below the level in the float chamber A. The practically no depression exists in the venturi P venturi P discharges into the mixture outlet Q then fuelfiows from A to B past the valveN in which is located the throttle R. vThis throt-- up the passage 0, into the-venturi P, and contle R is controlled by a lever S, which is manna 'tinues to flow under the infiuenceof gravity head 45 ally controlled at one end and is connected atinthefioat chamber A. This feature is disclosed l00 the other end through the rod T with the rod in the applicant's copending application Serial] U. U engages with the upper side of the pis- No. 422,516 filed January 22, 1930. The function ton C so that when the throttle R. is opened of the spring E is to provide a, followup for the piston CD--E--F descends. The perfothe pump discharge so that when the throttle is so rated tube J is vented to the air entrance through snapped opened the pump continues to disthe passage V which communicates with an ancharge. This well known feature is taken from nular chamber W, which surrounds the perthe Munson Patent 1,228,692. As theoutlet of forat'ed tube J. This being the well known 0 into P is below the fuel level in the float chard- Daimler construction as shown in the British her there isno necessity to connect. the assageO v: 5t Daimler Patent No. 10,786 of the year 1885 page with the pump cylinder B, and if t e valve N is removed from the bottom of the cylinder 13, as shown in Fig. 2, substantially equivalent results will be obtained. The valve N is then operated by an arm V' attached to V so that the valve N opens at the same angular position of the throttle R as the valve N in Fig. 1 opens.

-What I claim is:

1. In a carburetor having an air entrance, a mixture outlet, a throttle valve therein, a mixture chamber intermediate the throttle and the air entrance, a constant level fuel supply chamber, an accelerating pump fed therefrom, a piston in said pump, means interconnecting said piston with said throttle, an outlet from said pump discharging into said mixing chamber said outlet being vented to the: atmosphere at a point above the level in said supply chamber, a second outlet from said pump discharging into said mixture chamber at a point below the level of said fuel supply, valve means engaging with said pump controlling said second fuel outlet whereby said second fuel outlet is only in operation when the throttleis substantially .wide open.

2. In a carburetor having an air entrance, a

outlet from said pump discharging into said mixture chamber at a point below the level of said fuel supply, valve means engaging with said pump controlling said second fuel outlet whereby said second'fueloutiet is only in operation when the throttle is substantially wide open.

3. In' a downdraft carburetor having an air. entrance, a mixture outlet, a throttle valve therefrom, a piston in said pump, means interconnecting said piston with said'throttle, an outlet from said pump discharging into said mixing chamber said outlet being vented to the atmosphere at a point above the level in said supply chamber, another outlet from said fuel chamber discharging into said mixture chamber at a point I below the level in said fuel chamber, valve means Bti.

controlling said second outlet interconnected with said throttle so that said second fuel outlet is only, in operation when the throttle is substan-,

tially wide open. a v

4. In a downdraft carburetor having an air entrance, a mixture outlet, a throttle valve therein, a mixture chamber intermediate the throttle and the air entrance, a constant level fuel supply chamber, an accelerating pump fed therefrom,

a piston in said pump, yieldable means interposed chamber, another outlet from said fuel chamber discharging into said mixture chamber at a point below the level in said fuel chamber, valve means controlling said second outlet interconnected with said throttle so that said second fuel outlet is only in operation when the throttle is substantially wide open.

5. In a carburetor having an air entrance, a mixture outlet, a throttle valve therein, a mixture chamber intermediate the throttle and the air entrance, a constant level fuel supply chamber, an accelerating pump fed therefrom, a piston in said pump, means interconnecting said piston with said throttle, an outlet from said pump discharging into said mixing chamber said outlet being vented to the atmosphere at a point above the level in saidsupply chamber, an air vented well associated with said outlet, another outlet from said fuel chamber discharging into said mixture chamber at a point below the level in said fuel chamber, valve means controlling said second fuel outlet interconnected with said throttle so that said second fuel outlet is only-in operation when the throttle is substantially'wide open.

6. In a carburetor having an air entrance, a mixture outlet, a throttle valve therein, a mixture chamber intermediate the throttle and the air entrance, a constant level fuel supply chamber, an accelerating pump fed therefrom, a piston in said pump, yieldable means interposed between said piston and said throttle, an outlet from said pump discharging into .said mixing chamber saidoutlet being vented to the atmosphere at a point above the level in said supply chamber, an air vented well associated with said outlet, another outlet from said fuel chamber discharging into said mixture chamber at a point below the level in said fuel chamber, valve means controlling said second fuel outlet interconnected with said throttle so that said second fuel outlet is only in operation when the throttle is substan tially wide open. a

'7. In a carburetor having an air entrance, a mixture outlet, a throttle valve therein, amixture chamber intermediate the throttle. and the air 20 entrance, a constant level fuel supply chamber, an accelerating pump fed therefrom, a piston in said pump, means inter-connecting said piston with said throttle, an outlet from said pump'discharging into said mixture chamber at a point below the level of said fuel supply means, valve means engaging with said pump and controlling said outlet whereby said fuel outlet is held open when the throttle is substantially wide open.

8. In a carburetor having an air entrance, a

mixture outlet, a throttle valve therein, a mixture chamber intermediate the throttle andthe air entrance, a constant level fuel supply chamber, an accelerating pump fed therefrom, a piston in said pump, yieldable means interposed between said piston and said throttle, an outlet from said pump discharging into said mixture chamber at'a point below the level of said fuel supply means, valve means engaging with said pump and controlling said outlet whereby said fuel outlet is held open when the throttle is substantiallywide open;

' BERT BEARD.