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Патент USA US3037761

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June 5, 1962
B. c. PHILLIPS
'
3,037,751
CHARGE FORMING METHOD AND APPARATUS
Filed July 20, 1959
2 Sheets-Sheet 1
20’
134 '
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72 74 7a
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62 50
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72 74 54
INVENTOR:
as
Fri-5'-
EBRNARD
[7. PHILLIPS.
BY
-
Mam
United States Patent O?ice
"
1
3,037,751
Bernard C. Phillips, Toledo, Ohio, assignor to The Tillot
CHARGE FORMING METHOD AND APPARATUS
son Manufacturing Company, Toledo, Ohio, a corpora
tion of Ohio
Filed July 20, 1959, Ser. No. 828,331
17 Claims. (Cl. 261—35)
This invention relates to a method of ‘forming a com
bustible fuel and air mixture and charge forming ap
paratus for use with an internal combustion engine, and
more especially to a charge forming apparatus embody
ing a diaphragm-controlled fuel inlet valve means where
in liquid fuel is delivered from a fuel reservoir or dia
3,037,? 51'
Patented June 5, 1962
2
retors no predetermined fuel level is maintained thus
rendering it dif?cult to provide for the temporary delivery
of additional fuel to a mixing passage for engine ac
celerating purposes as is accomplished by gravity ?ow of
fuel in carburetors embodying ?oat-controlled fuel inlet
valve means.
The present invention embraces a method of providing
for the temporary delivery of additional liquid fuel into
a mixing passage of a diaphragm type carburetor wherein
a ?uid pressure impulse is imparted to the diaphragm
controlling the fuel inlet valve means under the in?uence
of a sudden opening movement of the throttle valve for
temporarily increasing fuel flow through the carburetor
into the mixing passage to facilitate rapid engine ac
phragm chamber in the charge forming apparatus into 15 celeration.
an air and fuel mixing passage under the in?uence of as
The present invention embraces the provision of a
piration or dilferential pressure established by air ?ow
charge forming apparatus of the diaphragm type adapted
through the mixing passage, the method and apparatus
for use with two-cycle and four-cycle engines wherein an
of the invention involving the delivery of an increased
impulse is imparted to the fuel ?ow control diaphragm
amount of fuel into the mixing passage for engine ac
under the in?uence of the position of the throttle valve
celerating purposes to temporarily enrichen the normal
to promote temporary increase in the flow of liquid fuel
fuel and air mixture when the throttle is suddenly
into the diaphragm chamber and into the mixing passage
opened to increase the speed of the engine.
to provide for enrichened mixture for engine accelerating
Carburetors or charge forming devices embodying a
purposes.
diaphragm-controlled fuel inlet means for a diaphragm 25 Another object of the invention is the provision of a
chamber in the carburetor have come into extensive use
for delivering combustible fuel and air mixture to two
cycle engines of the types having particular utility for
charge forming apparatus or carburetor embodying a
diaphragm-controlled fuel inlet means and equipped with
a second diaphragm or movable means adapted to be in
powering chain saws, outboard motors, lawnmower-s and
?uenced by a sudden opening of the throttle valve for
the like, but such diaphragm carburetors up to the present 30 transmitting a ?uid pressure impulse to the fuel inlet con
time have not been extensively used for supplying com
trol diaphragm to effect a momentary increase in the flow
bustible mixture to engines of the so-called four-cycle
of liquid ‘fuel through the diaphragm chamber into the
or Otto cycle type.
mixing passage.‘
Diaphragm type carburetors, especially those for use
Another object of the invention is the provision of a
with low horsepower internal combustion engines of the 35 novel method and apparatus for temporarily enrichening
two-cycle type have been particularly successful by rea
the fuel and air mixture in a charge forming device re
son of certain characteristics of a two-cycle engine. In
sponsive to opening movements of the throttle valve, the
the operation of two-cycle engines, the fuel and air mix
method and apparatus being especially adaptable for use
ture is introduced into the crankcase of the engine and
on [four-cycle engines where a temporary enrichenment
following crankcase compression of the mixture, the 40 of the mixture is imperative under increased load and
same is channeled into the cylinder and therein com
speed conditions of the engine for proper operation.
pressed by movement of the piston prior to the ignition
Another object of the invention resides in the provision
or burning of the charge in the cylinder.
of means embodied in or associated with a carburetor or
The crankcase of an engine of the two-cycle type usually
charge forming apparatus equipped with a diaphragm
contains an appreciable amount or residue of wet mixture 45 controlled ‘fuel inlet valve which is substantially in
or liquid fuel which, when the throttle of the charge
stantaneously responsive to sudden opening movements
forming device or carburetor is opened, provides an ex
of the throttle valve in the mixing passage of the charge
cess of liquid fuel or wet mixture for temporarily en
forming apparatus for rapidly supplying additional fuel
richening the charge delivered into the engine cylinder
into the mixing passage through a pressure impulse im
50
facilitating rapid acceleration of the engine when the
parted to the fuel inlet controlling diaphragm.
throttle is quickly moved to full open or near open posi
tion. However certain types of two-cycle engines tend
to function with a dry crankcase and lack an excess of
liquid fuel or wet mixture in the crankcase for engine
accelerating purposes.
Four-cycle engines are usually equipped with compara
Further objects and advantages are within the scope
of this invention such as relate to the arrangement, op
eration and function of the related elements of the struc
ture, to various details of construction and to combina
55
tions of parts, elements per se, and to economies of manu
facture and numerous other features as will be apparent
tively short intake manifolds or ducts for conveying com
from a consideration of the speci?cation and drawing
bustible mixture from a charge forming device into the
of a form of the invention, which may be preferred, in
cylinders and practically no accumulation of liquid fuel or
which:
60
wet mixture is contained in the manifolds. In engines of
FIGURE 1 is a top plan view of a charge forming ap
this type any additional ‘fuel for temporarily enrichening
paratus or carburetor embodying the invention;
the mixture for engine accelerating purposes must be sup‘
FIGURE 2 is a bottom plan view of the carburetor
plied by means associated with the charge forming de
illustrated in FIGURE 1 with the fuel ?ow control dia
vice or carburetor.
phragm removed for purposes of illustration;
Heretofore the conventional ?oat-type carburetor has 65 FIGURE 3 is a longitudinal section-a1 view taken sub
been almost universally used for supplying combustible
stantially on the line 3——3 of FIGURE 1;
mixture to four-cycle engines as the ?oat-type carburetor
IGURE 4 is a transverse sectional view taken sub
embodies a ?oat-controlled fuel inlet valve which estab
stantially on the line 4-4 of FIGURE 2;
lishes a de?ned fuel level in a carburetor fuel chamber or
FIGURE 5 is a bottom plan view of a modi?ed form
bowl, and various means have been extensively used in 70 of carburetor embodying the invention;
?oat~controlled carburetors for delivering enrichened mix
FIGURE 6 is a longitudinal sectional view taken sub
ture to the manifolds. In most diaphragm type carbu
stantially on the line 6-—6 of FIGURE 5;
3,037,751
3
FIGURE 7 is a top plan ‘view of another form of
carburetor embodying the invention;
FIGURE 8 is a side elevational view of the carburetor
illustrated ‘in FIGURE 7 with a portion of the construc
tion shown in section;
FIGURE 9 is a longitudinal sectional view taken sub
stantially on the line 9-—~9 of FIGURE 7;
4
tion 56 which engages the periphery of the second dia
phragm 50 ‘as shown in FIGURES 3 and 4.
The circular planar region or boss portion 42 is pro
vided with a plurality of circumferentially spaced open
ings 58, and the ring 46 and plate 54 are formed with
openings aligned therewith to accommodate securing
screws 60, one of which is shown in FIGURE 4 threaded
into the openings 58 for securing the diaphragms 44, 50,
FIGURE 10 is a transverse sectional view taken sub
the annular member 46, the closure plate 54 in proper
assembled position to the body 10 as shown in FIGURES
3 and 4. The circular boss portion 56 of closure mem
ber 54 de?nes a circular chamber 62 which is vented in
stantially on the line 10—10 of FIGURE 7;
FIGURE 11 is a detail sectional view taken substan
tially on the line 11—11 of FIGURE 8, and
FIGURE 12 is a sectional view taken substantially on
the line 12—12 of FIGURE 8.
the outlet region 15 of the mixing passage through the
medium of ducts or channels 64 and 66, the ducts inter
Referring to the drawings in detail, and initially to the
form of the invention illustrated in FIGURES 1 through 15 secting in the member 54 as shown in 53.
The chamber 52 is vented to the atmosphere through
4, the charge forming apparatus or carburetor is inclu
a metering passage or restricted duct 68 which is of very
sive of a carburetor body or body member 10 preferably
small size or area for a purpose to be hereinafter ex
of die cast construction formed with a mixing passage
plained. The ?rst ‘diaphragm 44 provides a component
12 into which liquid fuel is delivered and mixed with
of means for controlling the ingress or ?ow of liquid fuel
the air in the passage providing a combustible mixture
into the chamber 40 from a fuel supply in accordance
for delivery to an internal combustion engine with which
with the normal rate of delivery of fuel into the mixing
the carburetor may be used.
passage 12. The fuel chamber 40 is unvented to the at
The mixing passage is formed with an air inlet 14, and
mosphere and is actuated or ?exed solely by aspiration
a Venturi 16 having a choke band or restricted region
or reduced pressure set up by the velocity of the air stream
25
18. The carburetor !body 10 is formed with ‘a mounting
moving through the mixing passage.
?ange 20 at the outlet end 15 of the mixing passage and
The aspiration or suction in the chamber 40 is effec
is provided with openings 21. The outlet of the mixing
tive to cause delivery of fuel through fuel discharge or
passage is adapted to register with an intake manifold of
delivery passages or nozzles hereinafter described open
a four-cycle type engine where the carburetor is used
with a four-cycle engine, or is adapted to register with 30 ing into the mixing passage 12. The diaphragm 44 is
also actuated by impulse pressure set up or established
a port in the crankcase of a two-cycle engine where the
in
the chamber 52 under certain operating conditions as
carburetor is used with an engine of the latter type, the
hereinafter explained.
openings 21 accommodating bolts or other means for
The central region of the closure member or plate 54
securing the mounting ?ange either to a manifold or an
engine crankcase construction.
Disposed in the ‘air inlet region 14 of the carburetor
body 10 is a choke valve 24 of the disk type mounted
upon a shaft 26 journaled for rotation in openings formed
in boss portions provided on the carburetor body. The
cc WI
is provided with a depending hollow boss portion 70,
the hollow region accommodating an expansive coil
spring 72. Disposed at each side of the second dia
phragm 50 are thin metal reinforcing disks or plates 73
and 74 and a rivet or member 75 extends through open
choke valve supporting shaft 26 is equipped with an ‘arm 40 ings in the plates and diaphragm. The expansive spring
72 bears against the disk or plate 74 on the lower side
or manipulating member 27 for manually rotating the
of the diaphragm 50 and normally ?exes or maintains
shaft. The outlet region of the mixing passage is pro
vided with a disk-type throttle valve 30 mounted upon
a throttle shaft 32 journaled in suitable bores formed in
the diaphragm 50 in the broken line position shown in
FIGURE 3.
An elongated recess 78 is formed in an upper wall de
45
the carburetor body 10.
?ning the shallow fuel chamber 40 in the body 10 and
The throttle shaft 32 is equipped with a manipulating
accommodates a lever 80 formed of sheet metal, the
arm or member 34, a coil spring 36 surrounding an ex
lever 30 being provided intermediate its ends with a loop
terior region of the shaft and engaging the arm 34 to nor
portion to accommodate a pin 82, shown in FIGURE 4,
mally bias or urge the throttle valve 30‘ toward engine
the pin 32 forming a fulcrum or pivotal axis for the lever
idling or substantially closed position. An adjusting screw
80. As shown in broken lines in FIGURE 2, the pin
(not shown) is associated with the throttle shaft 32 for
82 is formed with a threaded portion 83 which is thread
adjusting the idle position of the throttle valve 30. As
ed into a bore formed in the carburetor body to facili
particularly shown in FIGURES 2 through 4, the car
tate assembly of the lever in the carburetor body.
buretor body is formed with a generally circular recess
providing a relatively shallow fuel chamber 40 de?ned by 55 Disposed at opposite sides of the ?rst diaphragm 44
a circular portion 42.
A ?exible diaphragm or membrane 44 formed of im
are metal disks 84 and 85 and a member or rivet 86
extends through openings in the disks and diaphragm.
The head portion of the rivet 86 is adapted to be en
gaged by‘ the long arm 83 of the lever 30. An expansive
bon fuels extends across the shallow fuel chamber 40
and forms a ?exible wall of the chamber. Disposed be 60 coil spring 90 disposed in a circular bore 91 engages
the lever arm 88 and normally biases the arm 88 into
tween the circular periphery of the diaphragm 44 and the
engagement with the rivet 86 whereby movement of the
circular portion 42 is a sealing gasket 45 to provide a
pervious material resistant to deterioration by hydrocar
?uid tight seal between the periphery of the diaphragm
diaphragm 44 effects pivotal movement of the lever 80.
The short arm 92 of the lever St) is adapted to engage an
engages the opposite peripheral face of the diaphragm 44 65 end of a fuel inlet valve member or valve body 94.
The carburetor body 10 is formed with a threaded bore
as particularly shown in FIGURES 3 ‘and 4.
to receive a valve cage or valve guide fitting 96, the
Extending across the circular region de?ned by the an
fitting being provided with a central bore adapted to
nular member 46 is a second diaphragm or pressure im
and the carburetor body. An annular member or ring 46
pulse producing means ‘50 formed of ?exible impervious 70 loosely and slidably accommodate the valve member 94
which is preferably of rectangular cross-section. Ar
material and, in cooperation with the diaphragm 44, forms
ranged in a counter bore at the upper end of the ?tting
a second chamber 52 which provides an impulse region
96 is a valve seat or member 98 preferably formed of
or chamber for purposes hereinafter explained. Disposed
yieldable or semi-hard material such as neoprene or
at the opposite side of the second diaphragm 50 is a
closure plate or member 54 having a peripheral boss por 75 other suitable material which is resistant ‘to deterioration
5
3,037,751‘
6
by hydrocarbon fuels. The valve seat 98 is of annular
shape and provides a fuel inlet port 100.
A sealing gasket 1112 is disposed between the end of
mounted a second threaded valve member 142 provided
with a knurled ?nger grip or knob 143 for adjusting the
position of the member 142 for regulating or metering fuel
?ow to the secondary ori?ces. The member 1412 is pro~
the ?tting 96 and a ledge formed at the end of the bore
in the carburetor body accommodating the ?tting. The
vided with a tenon portion 144 terminating in a tapered
valve member or body 94 is formed with a cone-shaped
valve portion 145 which extends into and cooperates with
a bore 146 of reduced diameter which is in communica
valve portion 104, the apex region of the valve portion
104 extending into the port 100 and cooperating with the
tion with the bore 140*.
The bore 146 opens into the
valve seat 98 to regulate or control the ?ow of liquid
fuel from a supply into the diaphragm chamber or fuel
reservoir 40.
The carburetor body 10 is formed with a boss por
tion 106 provided with a threaded bore to accommodate
means of a channel or duct 148 shown in FIGURE 2.
control means extremely sensitive to minute pressure
where the throttle valve 30‘ is moved comparatively slowly
auxiliary chamber or region 134 adjacent the secondary
ori?ces.
The passages 122 and 140 are in communication by
The channel 148 is fashioned by drilling a passage from
a threaded ?tting 107 which is adapted to be connected
the
mounting ?ange region of the carburetor into the
with a fuel supply (not shown).
15 passage 122 as shown in FIGURE 2, and the entrance of
The body 10 is provided. with communicating passage
the drilled passage closed by a plug 151}. An air bleed
ways 108 and 109 through which liquid fuel from the
passage 152 opens into the mixing passage and establishes
supply flows to the port 100 in the valve seat 93. The
communication with the recess or region 134 adjacent the
fuel supply for the carburetor may be by gravity ?ow
secondary ori?ces, as shown in FIGURE 3. Through this
directly from a tank or receptacle, or the ?tting 107 con
arrangement air is bled into the fuel delivered through the
nected with a fuel pump for supplying liquid fuel under
secondary ori?ces 114 and 116.
pressure to the carburetor. The port 100 in the valve
The operation of the carburetor or charge forming de
seat 98 is of comparatively small diameter in order to
vice illustrated in FIGURES 1 through 4 is as follows:
present a minimum ‘area of the valve portion 104 to the
The operation of the carburetor will ?rst be described
pressure of the incoming fuel in order to render the fuel 25
from one position to another viz. as from an idling posi
variations in the chamber 40.
tion to an intermediate position and full open or high
The carburetor body includes ducts, channels or pas
speed engine operation position. The main fuel chamber
sages formed or drilled therein for conveying fuel from
the fuel chamber 40 into the mixing passage 12. In 30 or reservoir 30 is unvented and is therefore subservient
to the in?uence of aspiration or reduced pressure existent
the form shown in FIGURES 1 through 4, a main fuel
in the mixing passage 12 during engine operation.
delivery ori?ce or outlet 112 opens into the choke band
When the throttle is in idling position, that is, substan
18 of the Venturi 16. The fuel delivery arrangement
'tially closed position as illustrated in FIGURE 3 a high
includes secondary or supplemental ori?ces 114 and 116
suction or aspiration is existent on the engine side of the
opening into the mixing passage providing means for
delivering fuel into the mixing passage for idling and
low speed engine operation. The main ori?ce 112 is
for the pulpose of delivering fuel into the mixing pas
sage for high speed engine operation.
35
throttle 30 and is effective to cause ‘fuel to be delivered
from the chamber 40‘ through the idling ori?ce 114.
Whenever fuel is being delivered into the mixing passage
through any ori?ce or ori?ces, the amount of fuel in the
The main ori?ce 112 is in communication with a bore 110 chamber 40 is depleted and the aspiration or reduced
pressure is effective to ?ex the diaphragm 44 upwardly
or chamber 118 closed at its end by a plug 120. The
as viewed in FIGURES 3 and 4.
carburetor body is formed with a threaded bore 122
As the diaphragm 40 moves upwardly, the rivet or
adapted to threadedly receive a member 124 which is
member 86 exerts upward pressure upon the lever 80
provided with a knurled knob or ?nger grip portion 125.
swinging the lever in a counterclockwise direction as
The member 124 is provided with a stem 126 having
a tapered extremity or valve portion 127 which extends 45 viewed in FIGURE 4. This action permits the valve body
94- and valve portion 104 to move downwardly, whereby
into a bore 128 which is in communication with the
bore 118 adjacent the main or primary fuel discharge
ori?ce 112.
The bore or passage 122 in the carburetor body is in
communication with the fuel chamber 40 by means of
a port or duct 130 shown in FIGURE 2. Thus fuel en
ters the port 130 from the chamber 40 and ?ows past
the tapered valve 127, bore 118 and through the main
ori?ce 112 into the mixing passage for high speed en
gine operation. The fuel flow into the mixing passage
takes place by reason of the aspiration or reduced pres
sure existent in the mixing passage during engine opera
tion. By manipulating the valve member 124 the fuel
fuel flows ‘from the supply through the passages 1118, 109
and port 100 into the fuel chamber 46. The valve body 94
being of polygonal shape in cross-section facilitates fuel
?ow into the chamber 49 thence through an ori?ce or ori
?ces into the mixing passage. The rate of delivery of fuel
to the secondary ori?ces is regulated or metered by adjust_
ing the position of the valve member 142.
When the throttle valve 30 is moved gradually toward
open position, the secondary or low speed ori?ce 116 is
brought into operation delivering fuel from the region 134
into the mixing passage for low speed engine operation.
During partial open throttle condition, fuel may be de—
?ow through the main ori?ce may be regulated or me
livered into the mixing passage ‘from both the secondary
60 ori?ces 114 and 116. When the throttle 30‘ is moved
tered.
The form of the invention of FIGURES 1 through 4
gradually toward open position, the ‘air moving through
includes a secondary fuel delivery system by means of
the Venturi 16 increases in velocity.
the ori?ces 114 and 116. The ori?ce 114 may be re
When the air velocity in the Venturi 16 is substantial,
ferred to as an idling ori?ce and serves to deliver fuel
the in?uence of aspiration or reduced pressure causes fuel
65
into the mixing passage at the engine side of the throt
to be delivered from the fuel chamber 40 past the high
tle valve 30 when the throttle valve is in substantially
speed adjusting or metering valve 127 through the main
closed- or engine idling position as shown in FIGURE 3.
ori?ce 112 into the Venturi. When this condition ob
Means is provided for metering or controlling the flow
tains ‘a high engine speed, the discharge of fuel through
of fuel to a chamber, recess or region 134 for delivery
the secondary ori?ces 114 and 116 usually ceases, although
through the secondary ori?ces 114 or 116. The recess 70 there may be a period in the operation of the engine when
or region 134 is isolated from direct communication with
fuel delivery ‘from the ori?ces 114 and 116 may overlap
the fuel chamber 40 by means of a Welsh plug 136.
the delivery of fuel from the main ori?ce 112.
The body 10 of the carburetor is [formed with a
When the throttle valve 30 is again moved to nearly
threaded bore or passage 140‘ in which is adjustably 75 closed or idling position fuel delivery through the main
3,037,751
7
ori?ce 112 ceases and fuel is then delivered through the
second idling ori?ce 114 into the mixing passage.
The operation of the carburetor under conditions
wherein a temporary enrichenment of the mixture is estab
lished by the delivery of additional fuel into the mixing
passage in excess of the normal amount is as follows:
As previously mentioned when the throttle valve 30 is in
substantially closed position, that is, engine idling posi
tion, a reduced pressure or high aspiration exists in the
mixing passage on the engine side of the throttle valve
viz. at the right side of the valve as viewed in FIGURE 3.
In this position of the throttle valve under engine idling
operation, the suction or aspiration in the mixing passage
is effective through the passages 64 and 66 to establish
reduced pressure in the chamber 62 beneath the second
diaphragm 50.
Due to the substantial area of the dia
phragm 50, the reduced pressure in the chamber 62 ?exes
the diaphragm to its lower position as indicated in full
lines in FIGURE 3 and compresses the spring 72 to store
potential energy in the spring.
When the operator suddenly opens the throttle valve 3&1
to rapidly increase the speed of the engine, the pressure
effective on the passages 64 and 66 and chamber 62 is sub
stantially instantaneously increased, and the potential
energy is the compressed spring 72 flexes the diaphragm
50 upwardly at a rapid rate. As the vent 68 for the charm
ber 52 between the diaphragm 5t} and 44 is of small size,
8
ing the size of the air vent 68 in the member 46. By de
creasing the size of the vent 68 the magnitude of the
pressure impulse on the fuel control diaphragm 44 may be
increased and of a longer period of duration during which
an augmented amount of fuel ?ows through the main ori
?ce 112.
If the vent 68 is enlarged, the ?uid pressure impulse
acting against the diaphragm 44 will be of decreased
magnitude and of shorter duration due to a more rapid
equalization of pressure in the intermediate or impulse
chamber 52. Whenever the pressure is equalized in the
chamber 52, the fuel delivery from the chamber 40 into
the mixing passage continues under normal operating con
ditions.
FIGURES 5 and 6 illustrate a modi?ed form of carbu
retor arrangement embodying a pressure impulse fuel
flow acceleration means of the invention. In this form
the carburetor body It)’ is substantially the same shape
and character as the carburetor illustrated in FIGURES
1 through 4. This form of carburetor is formed with a
mixing passage having a portion 160 of circular cylindri
cal shape of substantially uniform cross-sectional area
from the air inlet region 14 to a ?ared outlet region 162 at
the mounting ?ange end of the carburetor.
The mounting ?ange 20' is of the same character as
that shown at 2% in FIGURE 1 and is adapted to be se
cured either to a manifold of a four-cycle engine or to the
crankcase of a two-cycle engine, depending upon the type
of engine with which the carburetor is used. The mixing
the air in chamber 52 and exerts a pressure impulse on
the under side of diaphragm 44 ‘forcing the fuel inlet con 30 passage at the air inlet end is provided with the choke
valve 24' mounted upon a shaft 26’. The throttle valve
trol diaphragm 44 upwardly thus opening the valve 9'4
30' is mounted upon a rotatable shaft 32'. The arrange
and permitting substantial increase in flow of fuel into
ment is provided with the fuel inlet control diaphragm
the chamber 40.
44-’ and an impulse diaphragm 50' which is associated with
This action substantially instantly increases the amount
a spring 72' in the same manner as shown in the construc
of fuel delivered through the main ori?ce 112 into the
tion
illustrated in FIGURES 1 through 4.
:mixing passage 12. The additional amount of fuel de
The diaphragm 44’ is engaged by a lever 80’ arranged
livered into the mixing passage temporarily enrichens the
the rapid upward movement of diaphragm 50 compresses
mixture delivered to the engine and hence causes a rapid
for cooperation with a fuel inlet valve in the manner shown
in FIGURE 4. Aspiration or reduced pressure in the mix
acceleration in the speed of the engine. After a short
ing passage 16% is transmitted through passages 64' and
40
period of time, the pressure in the intermediate chamber
66’ to the chamber 62' between the diaphragm 50' and
52 between the diaphragms is equalized or becomes atmos
the closure plate 54' whereby the chamber 62’ is under
pheric by air escaping through the restricted vent 68
the in?uence of differential pressures in the mixing pas
whereby the diaphragms 44 and 50 return to their posi
sage to cause movements of the diaphragm 50’ setting up
tions of normal operation.
pressure impulses effective to ?ex the fuel inlet control
When the throttle 30 is moved from open or near open
diaphragm 44 in an upward direction for the purpose of
position to an engine idling or substantially closed posi
accelerating fuel flow into the mixing passage.
tion, the pressure on the engine side of the throttle is
The annular member 46' is provided with a restricted
again reduced substantially and this reduced pressure or
air vent 63’ for equalizing the pressure in the intermediate
aspiration is transmitted to the chamber 62 through the
chamber 52'. Fuel flows through the inlet valve arrange
passages 64 and 66 to again cause the diaphragm St} to ment into the fuel chamber 40' as controlled by the po
be ?exed downwardly compressing the spring72.
sition of the diaphragm 44’.
Thus whenever the throttle valve 30 is moved to a
In this form of construction, the main fuel ori?ce 166
closed or nearly closed position, the spring '72 is com
is in communication with the auxiliary chamber or region
pressed and conditioned with potential energy in readi
134' and the secondary or idle ori?ce 168 is arranged to
ness to effect an upward pressure impulse, through the
open into the mixing passage at the engine side of the
medium of the air in chamber 52, upon the fuel inlet
throttle valve 30’ when the latter is in engine idling or
control diaphragm 44 to deliver automatically an in
nearly closed position.
creased amount of fuel through the main ori?ce 112
An air bleed tube 170 is angularly disposed in the man
whenever the throttle 30 is quickly moved to a full open
or near open position.
Through this method of storing potential energy in a
member responsive to aspiration or di?erential pressures
in the mixing passage, fuel flow is automatically increased
through the main ori?ce above that normally delivered to
the mixing passage whenever the throttle valve 30 is sud
denly moved toward a full open or near open position
providing an enrichened mixture for rapidly accelerating
the engine. This result is effected by reason of the dif
ferential pressures existent in different zones of the mixing
ner shown in FIGURE 6 and opens toward the air inlet
of the mixing passage to admit air into the recess or cham
ber 134' for admixing with the fuel delivered into the mix
ing passage. In this arrangement a single adjustment or
metering means is provided for regulating normal fuel
?ow from the fuel chamber 40' to the secondary chamber
or recess 134'.
As shown in FIGURE 5, a port 174 establishes com
munication between the fuel chamber 40’ and a passage
or bore 176 formed in the body. The bore is formed with
passage under the changing conditions at varying engine 70 a threaded portion to accommodate an adjustable valve
speeds and throttle positions.
member 178 of the general character of that shown at 142
The rapidity and magnitude of the impulse imparted to
in FIGURE 2, ‘the valve member 178 being provided with
the fuel ?ow control diaphragm 44 by upward movement
a knurled ?nger grip portion 180 to facilitate manual ad
of the second diaphragm 50 under the potential energy
justment. The bore or passage 176 is in communication
of the spring 72 may be regulated and controlled by vary
L
9
3,037,751
with the recess or chamber 134' by means of a passage
or duct 182 of reduced diameter.
A tenon portion of the valve member 178 is provided
with a tapered or needle valve portion 186 which extends
into and cooperates with the metering passage or restric
tion 182 for regulating fuel ?ow into the chamber 134'.
Adjustment of member 178 regulates the normal fuel ?ow
10
fuel chamber 240, and a diaphragm 244 extends across
the chamber 240 and forms a ?exible wall of the fuel
chamber. The diaphragm 244 is engaged at its peripheral
region by a circular member 246, the peripheral region
of the member 246 engaging the diaphragm 244 to secure
the same in sealing relation with a circular planar surface
242 on the body 210, a gasket 245 being disposed between
to both the main ori?ce 166 and the low speed or idling
the diaphragm and the body 210 to effect a seal.
ori?ce 168.
The fuel inlet control means is illustrated in FIGURE
The operation of the form of carburetor construction 10 10 and is inclusive of a lever 280, the long arm 288 of
shown in FIGURES 5 and 6 is as follows: With the throt
the lever being engaged by a rivet 286 at the central
tle valve 30' in engine idling or nearly closed position, fuel
region of the diaphragm 244. The lever is fulcrumed
flows from the fuel chamber 40’ through the port 174,
intermediate its ends on a pivot or fulcrum pin 282. The
passage 176, past the needle valve 186 through the re
short arm 290 of the lever is engaged with a lower end
stricted passage 182 and chamber 134' and into the mix 15 of a valve member or valve body 294, the upper end of
ing passage through the secondary ori?ce 168. When the
the valve body being provided with a tapered valve por
valve 34)’ is gradually opened the velocity in the central
tion 304 which cooperates with a ported valve seat 298.
region of the mixing passage 160 increases and fuel is
The port in the valve seat 298 is in communication with
delivered from the main ori?ce 166 although some fuel
a fuel inlet ?tting 307 through communicating passage
may continue to ?ow into the mixing passage through
ways 308 and 309.
the secondary ori?ce 168.
A coil spring 291 engages the lever 280 to normally
When the throttle 30' is in idling or nearly closed posi
bias the lever in a counterclockwise direction, as viewed
tion the aspiration or substantially reduced pressure on
in FIGURE 10, urging the valve portion 304 to valve
the engine side of the throttle valve 30', that is, at the
closing position. During fuel flow from chamber 240
right side of the throttle valve as viewed in FIGURE 6,
into the mixing passage, aspiration or reduced pressure
the pressure in the chamber 62’ is substantially reduced
set up in the chamber 240 from the mixing passage is
elfec-ting a compression of the spring 72'. When the valve
e?ective to elevate the diaphragm 244, which action
38’ is suddenly moved to open or nearly open position, the
swings the lever 280 counterclockwise to permit the valve
pressure adjacent the outlet end of the mixing passage
294 to move downwardly, opening the port in the seat
increases and this increase in pressure is communicated 30 298 whereby fuel from a supply (not shown) ?ows
to the chamber '62’v
through the ?tting 307, passages 308, 309 and the port
The potential energy stored in the spring 72' moves the
in the valve seat into the chamber 240'.
diaphragm 50 rapidly in an upward direction imparting,
The valve member 294 is loosely and slidably mounted
through the medium of the con?ned air in chamber 52',
within a ?tting 296 threaded into a bore in the carburetor
an upward impulse to the control diaphragm 44’, imme 35 body_ In this form of the invention an impulse dia
diately increasing the amount of fuel ?owing into the fuel
phragm is provided but is actuated by mechanical means
chamber 40' and hence increasing the amount of fuel
such as by movement of the throttle valve. The body
delivered into the mixing passage either through the main
of the carburetor is provided with channels and ducts
ori?ce 166 or the secondary ori?ce 168 to temporarily
adapted to convey fuel from the fuel chamber 240' into
enrichen the fuel and air mixture delivered to the engine.
the mixing passage. The main ori?ce 315 opens into the
In a short period of time, however, dependent upon
choke band 218 of the Venturi as shown in FIGURE 9.
the size of the air vent 68' the pressure in the intermediate
Disposed adjacent the main ori?ce is a ?tting 316
chamber 52’ is equalized and, when this occurs, the fuel
adapted to contain a ball check valve 317 to prevent back
control diaphragm 44' returns to its normal position in
bleeding through the main ori?ce duringfue-l discharge
?uenced thereafter by the aspiration or pressure existent 45 from the secondary ori?ce means. The ?tting 316 is pro
in the mixing passage to deliver fuel in a normal amount
vided with a reduced tubular tenon portion 318 which ex
either through the main ori?ce 166 or the secondary
tends into a well or supplemental chamber 320 shown in
ori?ce 168 or both depending upon the speed of operation
FIGURE 9. The chamber 320 is isolated from the fuel
of the engine. Under all conditions of operation of the
chamber 240 by means of a Welsh plug 341. An air
carburetor, some air is bled into the fuel through the
‘bleed passage 342 is in communication with the air inlet
tubular air bleed 172.
region 214 and with the supplemental chamber or well
A carburetor embodying a modi?ed form of the inven
320 as shown in FIGURE 9.
tion is illustrated in FIGURES 7 through 12 of the draw
The body 210 is formed with a bore 322 having a
ings. In this form, the carburetor body 218 is similar in
threaded portion to accommodate a threaded valve mem
shape to the body 10 shown in FIGURE 1. The car 55 ber 324 provided with a knurled ?nger grip or knob 326
buretor includes a mounting ?ange 220 which is adapted
for adjusting the position of the valve member 324.
to be secured to the manifold of an engine of the ‘four
The valve member is provided with a stem 327 provided
cycle type or with the crankcase of an engine of the two
with a tapered needle valve portion 328 which extends
cycle type. The mixing passage is inclusive of an air
into and cooperates with a restricted passage 329 for regu
inlet region 214, a Venturi construction 216 and a mix 60 lating the flow of fuel to the main or high speed ori?ce
ture outlet region 217 at the engine side of the throttle
315. A passage or duct 330, shown in FIGURE 11,
valve 230.
establishes communication between the fuel chamber 244]
The air inlet is provided with a choke valve 224
and the bore 322 for feeding fuel into the bore 322 and
mounted upon a rotatable shaft 226 and the outlet region
into the supplemental chamber or well 328‘.
217 of the mixing passage provided with a disk-type 65
As shown in FIGURES 9 and 12, the secondary sys
throttle valve 230 mounted upon a rotatable throttle shaft
232, The choke valve shaft 226 is provided with an arm
227 for manipulating the choke valve and the throttle
tem includes an idling ori?ce 345 and a low speed ori?ce
347 which open into a small chamber 348‘ formed in the
body of the carburetor, The chamber 348 is isolated
valve shaft 232 is provided with a manipulating arm 234
from the reservoir 240 by a Welsh plug 349.
for operating the throttle valve. A coil spring 236 sur 70
Formed in the body 218 is a threaded bore 352 which
rounds a portion of the shaft 232 exteriorly of the car
accommodates a valve body 354 having a threaded por
buretor body, the spring being engaged with the arm 234
tion threaded into the bore 352, the Valve member 354
to normally bias the throttle valve toward a closed posi
being provided with a knob 356 for adjusting the position
tion.
of
the valve member. The valve member 354 is formed
The carburetor body 210 is formed with a shallow 75
with a stem portion 358 having a tapered or needle-like
3,037,751
1l
extremity 360 which extends into and cooperates with a
restricted passage 362 which opens into the small cham
ber 348 of the secondary fuel delivery system to meter
fuel ?ow to the secondary ori?ces.
As particularly shown in FIGURE 12, a passage or
channel 364 is in communication with the chamber 320‘
and the bore 352 for conveying fuel from the well or sup
plemental chamber 320 to the bore 352 past the needle
valve 360 in passage 362 into the chamber 348 for de~
12
011 the throttle shaft 232. The chamber 376 is vented to
the atmosphere through an opening or passage 377.
The normal operation of the carburetor shown in FIG
URES 7 through 12 is essentially the same as the nor
mal operation of the carburetor illustrated in FIGURES
1 through 4 with the exception that the ball check mem
ber 317 disposed in the ?tting 316 adjacent the main
ori?ce functions to prevent back bleeding through the
main ori?ce into the secondary fuel discharge system when
livery into the mixing passage through the secondary 10 the latter is delivering fuel during idling or low speed
ori?ces 345 and 347.
The channel or passage 36-4 is
drilled into the body and the entrance of the drilled pas
sage closed by means of a plug 366 shown in FIGURE
12.
In the form of the invention shown in FIGURES 7
through 12, the arrangement for effecting delivery of ad
ditional fuel into the mixing passage for accelerating pur
poses is initiated by mechanical means such as by move
ment of the throttle toward open position. With par
ticular reference to iFIGURES 9 and 10, it will be seen
that the second or impulse diaphragm 250 is disposed
between the circular member 246 and a closure mem
ber 254.
In this form of construction the impulse chamber com
prises two compartments 252 and 252', the compartments
being partially separated by means of an inwardly extend
ing web 370 formed on the circular member 246 as shown
in FIGURES 9 and 10, a communicating passage 372
being provided in the web whereby the compartments
252 and 252' together provide an impulse chamber.
The closure member 254 is fashioned to provide a cham
ber 376 in which is disposed a lever 378 fulcrumed in
termediate its ends upon a pin or shaft 380. Arranged
at each side of the impulse diaphragm 250 are metal disks,
a rivet or member 382 extending through the disks as
shown in FIGURE 10, the head of the rivet or member
382 engaging one arm of the lever 378.
engine operations.
The ball check 317 serves an additional purpose in
that by closing of the main ori?ce a portion of the fuel
?owing through the chamber 328 to the secondary ori?ce
system enters and remains in the supplemental chamber
320 as an accelerating charge for subsequent delivery
through the main ori?ce.
When the operator moves the throttle rapidly to an
open position, the cam surface 388 simultaneously de
presses the rod 384- swinging the lever 378 to ?ex the
impulse diaphragm 250 upwardly, compressing the air
in the intermediate chamber 252 which imparts a pres
sure impulse on the fuel control diaphragm 244. The
diaphragm 244 is ?exed upwardly as viewed in FIGURE
10 permitting the valve 294 to open and admitting more
fuel into the fuel chamber 240.
The admission of added fuel into the chamber 240
provides for delivery of an increased amount of fuel into
the mixing passage through the main ori?ce 315 and this
is supplemented by the charge or amount of fuel present
in the well 320 which is immediately discharged by aspira
tion into the mixing passage when the throttle valve is
moved to an open position. After a short period of
time, the pressure in the intermediate chamber 252 is
equalized through the air vent provided by passages 388,
389 and restriction 390 so that the fuel control diaphragm
244 thereafter normally controls the ingress of fuel into
the chamber 24-0 in accordance with the rate of delivery
As particularly shown in FIGURE 10, the carburetor
of the fuel through the main ori?ce or through the sec
body 210, the circular member 246, and a ?ange region
of the closure member 254 are provided with aligned 40 ondary ori?ces.
It is desirable that the air vent restriction 390 be made
small enough so that the pressure in the impulse chamber
252 is equalized in a comparatively short period of time.
the lever 378, and the other end of the rod terminates in
The length of the acceleration impulse may be modi?ed
engagement with a cam surface 388 formed on the throt
tle shaft 232. As shown in FIGURE 8, the shape of 45 by changing the area of the vent restriction 390 and by
changing the contour of the cam surface 388 associated
the cam surface 388 on the throttle shaft 232 is con
with the throttle shaft 232.
?gurated whereby upon rotation of the throttle shaft to
It is to be understood that a bellows or similar means
move the throttle valve 23%) toward an open position,
may
be employed in lieu of the impulse diaphragm 250
the cam surface 388 moves the rod or shaft 384 down
and arranged to be operated by means associated with
wardly causing the lever 378 to be swung in a counter- ,
the throttle shaft in a manner to provide a fluid pressure
clockwise direction, as viewed in FIGURE 10, and exert
impulse effective on the fuel control diaphragm 244.
a rapid upward movement of the impulse diaphragm 250‘.
From the foregoing it will be apparent that the forms of
This movement of the impulse diaphragm in an up
the invention provide for temporary enrichenment of a
ward direction slightly compresses the air in the inter
fuel and air mixture for an internal combustion engine
mediate or impulse chamber 250 and causes an upward
which
is efficient and reliable in operation for accelerat
?exure of the fuel ?ow control diaphragm 244, which
ing purposes. The pneumatic or pressure impulse ac
action swings the lever ‘280 to a position whereby the
celerating arrangement of the invention is “position free”
valve 294- moves downwardly and admits additional fuel
i.e.
is adaptable for operation in all angular or inverted
into the chamber 240, thereby providing for additional
positions.
fuel delivered through the main ori?ce 315.
60
It is apparent that, within the scope of the invention,
As shown in FIGURE 9, the intermediate or impulse
modi?cations and different arrangements may be made
chamber 252 is vented into the air inlet region 214 of
other than as herein disclosed, and the present disclosure
the carburetor body by means of interconnected passage
bores to accommodate a shaft or rod 384 shown in FIG
URE 10. One end of the rod 384 engages an aim of
ways 389, 389’, and the metering restriction 390, the
latter being of minute size. The function of venting the
chamber 252 through a metering restriction 390 is to de
lay the equalization of pressure in the impulse chamber
252 at the time a pressure impulse is imparted to the
fuel ?ow control diaphragm 244 by positive upward
?exure of the impulse diaphragm 250.
A comparatively weak spring 392 is disposed between
the web 37 0 on the circular member 246 and the impulse
diaphragm 250 to maintain the rivet or member 382 in
continuous contact with the lever 378 and the rod 384
in continuous contact with the ‘cam surface 338 formed
is illustrative merely, the invention comprehending all
variations thereof.
1 claim:
1. A charge forming apparatus including, in combina
tion, means formed with a fuel and air mixing passage
and a recess, a throttle valve in the mixing passage, a
diaphragm forming with said recess an unvented fuel
chamber, an ori?ce opening into the mixing passage for
delivering fuel from the fuel chamber into the mixing
passage by aspiration in the mixing passage, a fuel inlet
formed in said means in communication with the fuel
' chamber, said diaphragm being responsive to differential
l3
3,03%,751
pressures in the mixing passage, means actuated by said
diaphragm for controlling flow of liquid fuel from a
supply into the fuel chamber, and means responsive to
movement of the throttle valve toward open position to
impart a pressure impulse to the diaphragm for admitting
additional fuel through the fuel inlet into- the fuel cham
14
phragm and rendered operative upon rapid movement of
the throttle valve toward open position to increase the
pressure in the impulse chamber effective on said ?rst dia
phragm to increase flow of fuel from the supply through
the fuel chamber and channel into the mixing passage.
6. Charge forming apparatus including, in combina
ber to accelerate the rate of fuel delivery through the
ori?ce into the mixing passage.
2. A charge forming apparatus including, in combina
tion, means formed with a fuel and air mixing passage and
rate of fuel delivered through the ori?ce into the mixing
7. Charge forming apparatus including, in combina
a recess, a ?rst diaphragm forming with said recess an
unvented fuel chamber, a throttle valve in the mixing pas
tion, means formed with a fuel and air mixing passage 10 sage, means including a channel for conveying liquid fuel
and a shallow recess, a throttle valve in the mixing pas
from the fuel chamber into the mixing passage by aspira~
sage, a diaphragm forming with said recess an unvented
tion in the mixing passage, fuel inlet valve means con
fuel chamber, an ori?ce opening into the mixing passage
trolled by movement of said diaphragm for regulating fuel
for delivering fuel from the fuel chamber into the mixing
flow from a supply into the fuel chamber, an impulse
passage by aspiration in the mixing passage, a fuel inlet 15 chamber, said diaphragm forming a wall of the impulse
formed in said means in communication with the fuel
chamber, a second diaphragm forming another wall of the
chamber, a valve for the inlet associated with and actu
impulse chamber, means rendered effective upon move
ated by said diaphragm for controlling flow of liquid fuel
ment of the throttle valve toward open position for moving
from a supply into the fuel chamber responsive to differen
said second diaphragm to transmit an impulse to said ?rst
tial pressures in the mixing passage, means responsive to
diaphragm through the air in the impulse chamber to in
movement of the throttle valve toward open position to
crease ?ow of fuel from the supply through the fuel cham
impart a pressure impulse to the diaphragm for admitting
ber and channel into the mixing passage, and a metering
additional fuel into the fuel chamber and increasing the
restriction for venting said impulse chamber.
passage, and means for regulating the duration of the 25 tion, means formed with a fuel and air mixing passage
pressure impulse.
3. A charge forming apparatus including, in combina
tion, means formed with a fuel and air mixing passage
and a shallow recess, a throttle valve in the mixing pas
sage, a diaphragm forming with said recess an unvented
fuel chamber, an ori?ce opening into the mixing passage
for delivering fuel from the fuel chamber into the mixing
passage by aspiration in the mixing passage, a fuel inlet
and a recess, a ?rst diaphragm forming with said recess
an unvented fuel chamber, a throttle valve in the mixing
passage, means including a channel for conveying liquid
fuel from the fuel chamber into the mixing passage by
aspiration in the mixing passage, fuel inlet valve means
controlled by movement of said diaphragm for regulating
fuel flow from a supply into the fuel chamber, an air
chamber, said diaphragm ‘forming a wall of the air cham
ber, a second diaphragm forming another wall of the air
chamber, said diaphragm being responsive to differential 35 chamber, said air chamber being vented through an air
pressures in the mixing passage, means actuated by said
metering restriction, and spring means responsive to
diaphragm for controlling ?ow of liquid fuel from a supply
rapid opening movement of the throttle Valve to effect
into the fuel chamber, an air chamber, means operative
movement of said second diaphragm to increase the pres
upon rapid movement of the throttle valve toward open
sure in said air chamber to impart an impulse to said
position to increase the pressure in the air chamber and 40 ?rst diaphragm through the medium of the air in the air
thereby impart a pressure impulse to the diaphragm for
chamber to increase flow of fuel from the supply through
admitting additional fuel into the fuel chamber to ac
the fuel chamber and channel into the mixing passage, the
celerate the rate of fuel delivery through the ori?ce into
size of said air metering restriction determining the dura
the mixing passage.
tion of the impulse effective on said diaphragm.
‘4. A charge forming apparatus including, in combina 45 8. A charge forming apparatus including, in combina
formed in said means in communication with the fuel
tion, means formed with a fuel and air mixing passage and
a shallow recess, a throttle valve in the mixing passage, a
?rst diaphragm forming with said recess, an unvented fuel
chamber, an ori?ce opening into the mixing passage for
tion, means formed with a fuel and air mixing passage
and‘ a shallow recess, a throttle valve in the mixing pas
sage, a ?rst diaphragm forming with said recess an un
vented fuel chamber, an ori?ce opening into the mixing
delivering fuel from the fuel chamber into the mixing 50 passage for delivering fuel from the fuel chamber into
passage by aspiration in the mixing passage, a fuel inlet
the mixing passage by aspiration in the mixing passage,
formed in said means in communication with the fuel
chamber, a valve for the inlet associated with and actu
a fuel inlet formed in said means in communication with
ated by said diaphragm responsive to differential pres
sures in the mixing passage for controlling flow of liquid
fuel from a supply into the fuel chamber, a second dia
phragm disposed adjacent to and spaced from the ?rst
and actuated by said ?rst diaphragm for controlling ?ow
of liquid fuel from a supply into the fuel chamber, said
?rst diaphragm being responsive to differential pressures
diaphragm, said diaphragms de?ning opposed walls of an
impulse chamber, and means effective upon rapid move
ment of the throttle valve toward open position to impart
movement to the ?rst diaphragm through the impulse
chamber for admitting additional fuel into the fuel cham
ber and increasing the rate of fuel delivered through the
ori?ce into the mixing passage.
the fuel chamber, a valve for the inlet associated with
in the mixing passage, a second diaphragm, said dia
phragms being spaced and de?ning opposed walls of an
air chamber, a closure plate exteriorly of the second dia
phragm and forming therewith a compartment, duct
means establishing communication between the compart
ment and the mixing passage, a spring in said compart
ment in engagement with the second diaphragm adapted
to control the position of said second diaphragm, and
5. Charge forming apparatus including, in combina
vent means for said air chamber.
tion, means formed with a fuel and air mixing passage 65 9. A charge forming apparatus including, in combina
and a recess, a ?rst diaphragm forming with said recess an
tion, means formed with a fuel and air mixing passage
unvented fuel chamber, a throttle valve in the mixing pas
and a recess, a throttle valve in the mixing passage, a
sage, means including a channel for conveying liquid fuel
?rst diaphragm forming with said recess an unvented
from the fuel chamber into the mixing passage by aspira 70 fuel chamber, an ori?ce opening into the mixing passage
tion in the mixing passage, fuel inlet valve means con
for delivering fuel from the fuel chamber into the miX
trolled by movement of said diaphragm for regulating fuel
?ow from a supply into the fuel chamber, a second dia
ing passage by aspiration in the mixing passage, a fuel
inlet formed in said means in communication with the
fuel chamber, a valve for the inlet associated with and
phragm forming .with said ?rst diaphragm an impulse
chamber, and spring means engaging the second dia 75 actuated by said first diaphragm for controlling ?ow of
3,037,751
liquid fuel from a supply into the fuel chamber, said ?rst
diaphragm being responsive to differential pressures in
the mixing passage, a second diaphragm spaced from
and disposed in parallelism with the ?rst diapragm and
forming with said ?rst diaphragm an air chamber, means
rendered effective upon movement of the throttle valve
to an unvented fuel chamber of variable volume, normal
ly regulating the rate of flow of fuel from a supply into
the fuel chamber by aspiration in the passage in ac
cordance with the rate of delivery of fuel into the mix
ing passage, and establishing an air pressure impulse upon
rapid opening movement of the throttle valve in the
toward open position for moving said second diaphragm
mixing passage effective to temporarily change the volume
in communication with the air chamber for determining
the duration of increased pressure in the air chamber.
impulse to restore normal regulation of the rate of fuel
?ow from the supply into the mixing passage.
14. The method of forming combustible mixture for
of the fuel chamber to increase fuel ?ow into the mixing
to compress air in said air chamber to actuate the ?rst
passage and provide an eniichened mixture in the mixing
diaphragm and increase fuel ?ow into the fuel chamber
and into the mixing passage, and restricted vent means 10 passage, and dissipating the air pressure providing the
10. A charge forming apparatus including, in combina
an internal combustion engine and temporarily increasing
tion, means ‘formed with a fuel and air mixing passage
and a shallow recess, a throttle valve in the mixing pas 15 fuel ?ow into an air and fuel mixing passage having a
throttle valve including establishing air flow in the pas
sage, a ?rst diaphragm forming With said recess an un
sage, transmitting reduced pressure caused by the aspira
vented fuel chamber, an ori?ce opening into the mixing
tion set up by the air ?ow to a ?exible membrane of a
passage for delivering fuel from the fuel chamber into
fuel chamber, normally regulating the rate of ?ow of fuel
the mixing passage by aspiration in the mixing passage, a
from a supply into the fuel chamber ‘by relative move
fuel inlet formed in said means in communication with
ment of the membrane by aspiration in the passage in
the fuel chamber, a valve for the inlet associated with
accordance with the rate of delivery of fuel into the mix
and actuated by said ?rst diaphragm for controlling ?ow
ing passage, and establishing a pressure impulse in an air
of liquid fuel from a supply into the fuel chamber, said
chamber effective on the membrane upon rapid opening
?rst diaphragm being responsive to differential pressures
movement of the throttle valve in the mixing passage for
in the mixing passage, a second diaphragm, said dia
temporarily changing the volume of the fuel chamber to
phragms forming opposed walls of an air chamber, a
increase fuel ?ow into the mixing passage and provide
member engaging the second diaphragm, means respon
an enrichened mixture in the mixing passage, and admit
sive to movement of the throttle valve toward open posi
ting air into the air chamber to equalize the pressure and
tion for effecting movement of said member and second
diaphragm to establish increased pressure in said air 30 restore normal regulation of the rate of fuel ?ow from
the supply through the fuel chamber into the mixing
chamber to actuate the ?rst diaphragm and increase fuel
passage.
?ow into the fuel chamber and into the mixing passage,
15. The method of forming combustible mixture for
and restricted vent means in communication with the air
an internal combustion engine and temporarily increas
chamber for determining the duration of increased pres
sure in the air chamber.
35 ing fuel ?ow into an air and fuel mixing passage having
a throttle valve including establishing air ?ow in the pas
11. A charge forming apparatus including, in combina
sage, transmitting pressure of aspiration set up by the air
tion, means formed with a fuel and air mixing passage
?ow in the mixing passage to a variable volume fuel
and a recess, a throttle valve in the mixing passage, a
chamber, normally regulating the rate of ?ow of fuel
shaft supporting the throttle valve, a ?rst diaphragm form
ing with said recess an unvented fuel chamber, an ori?ce 40 from a supply into the fuel chamber by the aspiration
in the passage in accordance with the rate of delivery of
opening into the mixing passage for delivering fuel from
fuel into the mixing passage, and establishing a ?uid
the fuel chamber into the mixing passage by aspiration
pressure impulse upon rapid opening movement of the
in the mixing passage, a fuel inlet formed in said means
throttle valve in the mixing passage effective to temporari
in communication with the fuel chamber, a valve for the
ly change the volume of the fuel chamber to increase fuel
inlet associated with and actuated by said ?rst diaphragm
?ow into the mixing passage and provide an enrichened
for controlling ?ow of liquid fuel from a supply into the
mixture in the mixing passage.
fuel chamber responsive to differential pressures in the
16. The method of forming a combustible fuel and air
mixing passage, a second diaphragm, an air chamber
mixture for an internal combustion engine for normal
formed between the diaphragms, means actuated by the
operation and for enrichening the mixture for accelera
throttle shaft for moving said second diaphragm to trans
tion purposes including ?owing air through a mixing
mit a pressure impulse by the air in the air chamber to
passage having a throttle valve therein, communicating
the ?rst diaphragm.
the differential pressure established by air ?ow in the
12. A charge forming apparatus including, in combina
mixing passage to a variable volume fuel chamber for
tion, means formed with a fuel and air mixing passage
delivering fuel from the chamber through a channel into
and a recess, a throttle valve in the mixing passage, a
the vmixing passage, normally regulating the rate of ?ow
shaft supporting the throttle valve, a ?rst diaphragm
of fuel from a supply to the fuel chamber by varying
forming with said recess an unvented fuel chamber, an
the volume of the fuel chamber by the pressure differen
ori?ce opening into the mixing passage for delivering fuel
tial in the mixing passage to establish a normal rate of
from the fuel chamber into the mixing passage vby aspira
delivery of fuel into the mixing passage, and establish
tion in the mixing passage, 21 fuel inlet formed in said
ing a pressure impulse exteriorly of the fuel chamber ef
means in communication with the fuel chamber, a valve
fective to temporarily reduce the volume of the fuel
for the inlet associated with and actuated by said ?rst
chamber upon rapid opening of the throttle valve in the
diaphragm for controlling ?ow ‘of liquid fuel from a
mixing passage to temporarily increase the ?ow of fuel
supply into the fuel chamber, said first diaphragm being
from the supply into the fuel chamber and from the fuel
responsive to differential pressures in the mixing passage,
chamber into the mixing passage to enrichen the mixture
21 second diaphragm, an air chamber formed by the dia
in the mixing passage for engine accelerating purposes,
phragms, and a lever arranged to be actuated by move
and dissipating the pressure impulse independently of the
ment of the throttle shaft for moving said second dia
position of the throttle valve.
phragm to transmit a pressure impulse to the ?rst dia
17. The method of forming a combustible fuel and air
phragm through the air in the air chamber.
mixture for an internal combustion engine for normal
13. The method of temporarily increasing fuel ?ow
operation and for enrichening the mixture for accelera
into an air fuel mixing passage for supplying combustible
tion purposes including ?owing air through a mixing pas
mixture to an internal combustion engine having a
sage having a throttle valve therein, communicating the
throttle valve including establishing air ?ow in the pas
sage, communicating the aspiration set up by the air flow
differential pressure established by air ?ow in the mix
17
3,037,751
ing passage to a movable surface of a variable volume
fuel chamber for delivering fuel ‘from the chamber
through a channel into the mixing passage, normally
regulating the rate of ?ow of fuel from a supply to the
fuel chamber by varying the volume of the fuel chamber 5
by the pressure differential in the mixing passage to
establish a normal rate of delivery of fuel into the mix
ing passage, establishing a pressure impulse exteriorly of
the fuel chamber and e?ective upon a ?exible surface of
the chamber to temporarily reduce the volume of the fuel
chamber upon rapid opening of the control valve in the 10
mixing passage to temporarily increase the flow of fuel
from the supply into the fuel chamber and from the fuel
18
chamber into the mixing passage to en-richen the mix
ture in the mixing passage, and dissipating the pres~
sure impulse independently of the position of the throttle
valve to restore normal rate of fuel delivery into the
mixing passage.
References Cited in the ?le of this patent
UNITED STATES PATENTS
2,387,271
2,601,975
2,823,905
2,841,372
Kittler et a1 ___________ __ Oct. 23,
Hunt ________________ __ July 1,
Brown ______________ __ Feb. 18,
Phillips ______________ _._ July 1,
1945
1952
1958
1958
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