U.S. patent number 3,872,188 [Application Number 05/331,198] was granted by the patent office on 1975-03-18 for apparatus for controlling and modulating engine functions.
This patent grant is currently assigned to ACF Industries, Incorporated. Invention is credited to Morris C. Brown, Forrest W. Cook, Kalert, Ralph E., Arthur C. Vollmer, Jerry H. Winkley.
United States Patent |
3,872,188 |
Brown , et al. |
March 18, 1975 |
APPARATUS FOR CONTROLLING AND MODULATING ENGINE FUNCTIONS
Abstract
Changes in barometric pressure and/or temperature can adversely
affect a number of engine functions. Apparatus is disclosed for
controlling and modulating a number of engine functions, including
carburetor idle fuel and main fuel supply, fuel enrichment during
acceleration and wide open throttle operation, as well as vacuum
applied to such vacuum motors associated with the engine as the
carburetor choke, the spark advance and automatic transmission
shift. Calibration features are provided for establishing a base
condition of operation as well as individual calibration of all the
various functions listed together with the ability to make base
calibration changes by application of an external signal.
Inventors: |
Brown; Morris C. (Florissant,
MO), Cook; Forrest W. (Webster Groves, MO), Kalert, Ralph
E. (Granite City, IL), Vollmer; Arthur C. (St. Charles,
MO), Winkley; Jerry H. (St. Louis, MO) |
Assignee: |
ACF Industries, Incorporated
(New York, NY)
|
Family
ID: |
23292988 |
Appl.
No.: |
05/331,198 |
Filed: |
February 9, 1973 |
Current U.S.
Class: |
261/39.2;
261/69.1 |
Current CPC
Class: |
F02M
7/28 (20130101); F02M 3/09 (20130101) |
Current International
Class: |
F02M
7/00 (20060101); F02M 3/09 (20060101); F02M
7/28 (20060101); F02M 3/00 (20060101); F02m
001/10 () |
Field of
Search: |
;123/119R,124A,124B
;261/DIG.2,39A,39B,69R,121B,177,179 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Antonakas; Manuel A.
Claims
1. In an internal combustion engine having a plurality of engine
functions operable by the suction created by the natural aspiration
of said engine during running condition, the improvement
comprising;
an attachment connected to said engine communicating on one side
with ambient air and on another side with at least one suction
controlled passage leading to at least one engine function
controlling means,
said attachment including a bellows responsive to barometric and/or
temperature changes of said atmospheric air to change a dimension
of said bellows,
said bellows being mounted in a housing, said housing also
including a pivotable plate surmounting said bellows,
at least one metering means being connected to said plate, said
metering means being adapted to meter ambient air to said at least
one engine function controlling means,
said pivotable plate being pivoted at one end thereof,
said plate adjustable contacting said bellows at an intermediate
position along the length of said plate,
said plate also having adjustable biasing means at the end opposite
said pivoted end, and
said biasing means constituting an adjustable spring adjustably
secured to said plate at a first end thereof and also adjustably
secured to said
2. Apparatus according to claim 1 in which the said also adjustably
secured portion of said spring includes means extending through
said housing whereby adjustment of said biasing means is made
externally of said
3. Apparatus according to claim 2 further including engine
operating condition sensing means, said sensing means including
means for translating said sensing to a movement for adjusting,
said means for adjusting being connected to said means extending
through said housing whereby to adjust said biasing means according
to changes in engine
4. Apparatus according to claim 3 in which said sensing means
comprises a temperature sensor in the exhaust system of said
engine.
Description
BACKGROUND OF THE INVENTION
There are a number of functions of the internal combustion engine
that are affected, usually adversely, by changes in operating
conditions such as barometric pressure, ambient temperature and
frequently one or more temperatures associated with the engine
itself. In the case of stationary engines, and other engines
operating under essentially constant load conditions, adjustments
can be made to achieve efficient operation of the engine under
these more or less constant conditions. In the case of the
automotive engine, no single set of adjustments are capable of
compensating for the constantly changing variables surrounding the
engine.
Among the several engine functions that can be affected by changes
in altitude and temperature, the idle fuel and main fuel systems of
the conventional carburetor are very important. These fuel metering
systems are severely affected by changes in altitude; so much so,
that with an unmodified carburetor the engine will receive an
unnecessarily rich mixture whenever there is any great departure
from sea level. Customarily, this situation has been accepted
and/or tolerated with the exception that if an automotive vehicle
is normally used at higher altitudes a permanent change is made to
reduce the size of the metering jet or to install a larger metering
rod, or both, and such modification allows the engine to operate
correctly so long as the vehicle is kept at substantially the same
altitude. If this vehicle is driven to sea level conditions, then
the mixture may be unduly lean. In a somewhat similar manner,
changes in temperature which directly affect the temperature of the
fuel as well as that of the air entering the carburetor will also
cause undesirable changes in the air/fuel ratio discharged by the
carburetor to the engine. For automotive engines, little has been
done to alleviate these conditions other than the use of a hot idle
compensator which can admit some additional air to the intake
manifold when ambient conditions have exceeded some preselected
temperature and this addition of air without additional fuel has
the affect of leaning the mixture out at the higher ambient
temperature. While automotive carburetors normally have made no
compensation for the above-mentioned variables, many aircraft
carburetors over the years have necessarily embodied altitude
compensation, but because of the considerable differences in the
carburetors used on aircraft with respect to those used on
automobiles, the overall approach to correcting fuel ratio is not
well suited to that of the automotive carburetor.
Power enrichment is another important carburetor function that is
adversely affected by changes in altitude and for which there has
been no compensation provided in commercial carburetors. Power
enrichment customarily is provided by opening an auxiliary fuel
passage or by moving a metering element so that additional fuel can
enter the main fuel system. In both cases, the manifold vacuum is
applied to one side of a diaphragm or piston and when manifold
vacuum is high only normal fuel quantities are allowed to enter the
main fuel system. When manifold vacuum becomes low then the movable
member shifts into another position, thus allowing enrichment fuel
to pass into the fuel system. The movable member (diaphragm or
piston) is normally biased by a spring to move toward the
enrichment position and the bias of this spring is overcome by the
manifold vacuum. If the spring is so adjusted that it will cause
enrichment whenever manifold vacuum drops below about 6 inches
mercury, then no enrichment occurs until the engine is heavily
loaded and usually a wide-open throttle condition has been reached.
On the other hand, when the same vehicle is operated at altitudes
of 5,000 feet or more, the power enrichment may come into play even
though the engine is relatively lightly loaded. This condition is
caused by the fact that barometric pressure at altitudes is
considerably less than that at sea level and this reduction in
ambient pressure is reflected in the intake manifold as a lesser
degree of manifold vacuum for normal operation. Accordingly, as the
engine is increased in its normal loading, the pressure condition
necessary for power enrichment may be reached far in advance of any
actual need for the enrichment.
There are other engine and vehicle functions that are also
dependent upon manifold vacuum and which functions can be adversely
affected by changes in altitude. One such engine function is the
advance and retard of the spark ignition which is normally done by
a diaphragm motor. Again, a considerable change in altitude may
cause the diaphragm motor to shift the spark advance at a time when
the engine does not require such a shift and this, then becomes an
undesirable result. In a similar fashion, some automatic
transmissions are equipped with a diaphragm actuated motor for
assisting in the shifting of the transmission mechanism. As is the
case of the spark advance, the automatic transmission vacuum motor
may come into play or fall out of play at an undesirable operating
condition.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a representation of an engine having the compensating
unit of the invention attached to the carburetor of the engine.
FIG. 2 is a plan view of the interior of the compensating unit.
FIG. 3 is a section along the lines of 3--3 of FIG. 2.
FIG. 4 is another section taken along the lines of 4--4 of FIG.
2.
FIG. 5 is a partial section of a carburetor showing the manner of
admitting air from the compensating unit into the main fuel system
of a carburetor.
FIG. 6 is a partial section of a carburetor showing the manner of
introduction of air into the idle system.
FIG. 7 is a partial sectional view of a carburetor showing a vacuum
controlled accelerating pump and having attached to said carburetor
a second vacuum controlled device and illustrating a passage for
air from the compensating unit to the vacuum passage in the
carburetor to modulate vacuum to the respective vacuum motors.
FIG. 8 is a partial plan view of a multibarrel carburetor
illustrating the compensating unit of the invention integrally
attached to the carburetor.
FIG. 9 is a partial section of the carburetor showing the idle fuel
adjustment screw and the air modulating passage from the
compensating unit.
FIG. 10 illustrates the air passage for passing air from the
compensating unit to the air metering portions of the carburetor of
FIG. 8.
FIG. 11 illustrates the communication of an air passageway of FIG.
8 with the secondary nozzle of the multibarrel carburetor of FIG.
8.
FIG. 12 is a partial section of the main fuel system of the primary
barrels of the carburetor of FIG. 8 illustrating the communication
of the modulated air from the compensating unit with the main fuel
nozzle.
FIG. 13 is another partial section of a carburetor showing the
vacuum piston which raises and lowers a fuel metering rod and
illustrating the vacuum passage which is modulated by the
compensating unit of the invention.
FIG. 14 is an elevation view of the compensating unit of FIG. 8
with the cover removed.
FIG. 15 is a sectional view of FIG. 14 with the cover in place.
FIGS. 16, 17, 18 and 19 are details of various construction
features of the compensating unit of FIGS. 14 and 15.
BRIEF DESCRIPTION OF THE INVENTION
In order to make the compensation for the various engine and
automotive functions described above, there is provided a
compensation unit which can be installed in the vehicle or made
integral with the carburetor as desired and this unit meters air
into the various systems involved in such a manner as to
automatically compensate for changes in engine operating
characteristics caused by changes in atmospheric pressure and/or
temperature.
Basically, the compensation unit includes a capsule which is
temperature and/or barometric sensitive to change its dimensions as
the altitude or the temperature varies. This capsule moves a plate
to which are attached a number of metering elements. One group of
metering elements are arranged in such a manner as to increase air
flow as the altitude increases and also increase air flow as
temperature increases. Another metering element is arranged to
operate in the opposite direction so that maximum air flow occurs
at low altitude and/or temperature and a decreasing quantity of air
flows as the altitude and/or temperature increases. The
first-mentioned group of metering elements provide an air bleed
into one or more of the fuel systems of the carburetor to overcome
the tendency toward richness as temperature and altitude increase.
Another metering element is adapted to admit larger quantities of
air at sea level and standard temperatures with a reduced quantity
of air as the altitude and/or temperature increases. This last
mentioned metering element serves to reduce what would normally be
a high manifold vacuum applied to some operative function of the
engine at low altitudes and low temperatures and to reduce the air
admitted with changes in those variables so that the vacuum
actually applied will remain substantially constant, irrespective
of any change in altitude or temperature.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 there is shown an altitude and/or temperature
compensating unit 10 attached to a carburetor 12 by a plurality of
conduits 14, 16, 18 and 20, which illustrate one realization of the
invention. Carburetor 12 is suitably mounted on an intake manifold
13 which delivers the usual air/fuel mixture to an engine 15.
Products of combustion are discharged from the engine into an
exhaust pipe 17 and thence to a muffler 19 from which the products
are discharged into the atmosphere. An air cleaner or filter 21 is
installed on carburetor 12 so that only clean filtered air is
delivered to the intake of the internal combustion engine.
Referring now to FIGS. 2, 3 and 4, compensating unit 10 is shown in
greater detail. The unit comprises a body portion 22 having a cover
23 which cover seals the unit from the atmosphere. Conduit 14,
which in this embodiment may be a rubber hose, is attached to a
nipple 24 for conducting clean air to the interior of unit 10.
Thus, the interior of unit 10 has air at substantially atmospheric
pressure inside it at all times. Any deviation from absolute
atmospheric pressure will be due to any pressure drop that may
occur across the filter element and air cleaner 21. Within housing
22, there is an ambient air condition responsive device 30 which,
in this instance, is a capsule of the bellows type which is
conditioned to have within it a predetermined air pressure which,
for barometric or altitude compensation represents a high degree of
evacuation of the interior of the capsule. Additionally, there may
be provided on the interior of capsule 30 a spring 32 which,
through proper biasing, makes the capsule responsive to give the
desired movement for a given change. High evacuation makes the
capsule almost totally responsive to barometric change, while
partial evacuation causes the capsule to respond to both barometric
and temperature change. Accordingly, the spring bias and degree of
evacuation will be chosen to achieve predetermined requirements.
The base of capsule 30 is secured to the housing 22 in any
convenient manner, in this instance by way of a boss 33. A detent
34 is provided at the upper end of capsule 30 for receiving an
adjustment screw 36 as will be hereinafter described. A plate 40 is
installed in an upper portion of housing 22 and is pivoted at 42 in
such a manner that it positions adjustment screw 36 above unit 30
so that changes of length in unit 30 occasioned by changes in
barometric pressure and/or temperature will cause plate 40 to move
upwardly and downwardly about the pivot 42.
A plurality of adjustment screws other than screw 36 are carried by
plate 40. These are identified as 44, 46, 48 and 50. Each such
adjustment screw is provided for the purpose of making final
adjustment and calibration of the metering elements and biasing
arrangements used in the device. Screw 44 at its lower extremity
contacts a metering pin 52 which, by way of conduit 16, controls
the quantity of air bled into the main fuel system. Such bleed air,
when increased in quantity serves to diminish the amount of fuel
delivered to the carburetor by the main fuel nozzle. When the bleed
air is reduced or cut off, a greater quantity of fuel is made
available through the main nozzle. Metering pin 52 is urged in an
upward direction by a biasing spring 54. Clean air from the
interior of housing 22 is admitted into the vicinity of metering
pin 52 by an air passageway 53 so that as pin 52 rises, the tapered
end portion uncovers the air entry passageway to admit air into
conduit 16 and thence, by way of conduit 16 to a passageway 55 in
the carburetor itself, which communicates with a portion of the
main fuel system and, in this instance, the anti-perk well 56. Air
passing into anti-perk well 56 then mixes with the fuel in
passageway 57 so that a mixture of air and fuel are discharged by
nozzle 58 into the boost venturi 60 of the carburetor. The fuel, of
course, is supplied from a constant level fuel bowl 62 and enters
the main fuel passage by way of a metering orifice 64 which is
controlled in part by a metering 66.
Air is bled into the idle fuel system in a manner substantially the
same as that described above with respect to the main fuel system.
Referring to FIG. 6, it will be seen that idle fuel is drawn by a
passage 70 from the main fuel passage 57 of FIG. 5 and passes
upwardly through a dip tube 71 and thence, through a restriction 72
where it is mixed with a quantity of air supplied by way of orifice
73, the resultant mixture then passes through restriction 74 where
additional air can be added by way of restriction 75, thence
downwardly by way of passage 77 to a cross-passage 78 which
terminates in the bore of the carburetor adjacent the throttle
valve.
Communication with the compensating unit is established by way of
restriction 79 and conduit 18 which connects with the compensating
unit and is supplied with metered air by way of metering pin 80
which is biased by way of a spring 81 in an outwardly direction and
which, as previously mentioned, is adjusted by way of adjustment
screw 46 carried on plate 40. It is to be mentioned that both
metering pins 52 and 80 are provided with a taper such that as
plate 40 moves upwardly, greater quantities of air are admitted
into conduits 16 and 18 thereby reducing the quantity of fuel
discharged by the main and idle fuel systems.
A final engine function that is accomplished by the compensating
unit of the invention is illustrated by two different embodiments
in FIG. 7. In that FIG. there are shown two vacuum responsive
devices in the form of diaphragm units. One of these controls the
step-up by which the carburetor is caused to provide enrichment
fuel under heavy-load or wide-open throttle conditions and the
other is a diaphragm motor such as can be used to control spark
advance or, in some instances, the shift mechanism of an automatic
transmission. It is to be recognized that any or all of these
vacuum responsive units could comprise a piston instead of a
diaphragm mechanism.
As shown in FIG. 7, conduit 20 is attached to the carburetor by
means of a tube 85 which intersects a passage 86 in the throttle
flange of the carburetor. Passage 86 enters the bore of the
throttle of the carburetor below the throttle valve 88. By means of
a branch passage, conduit 86 communicates with a space 90 below the
diaphragm of a diaphragm-type accelerating pump. The diaphragm is
shown at 91 and is attached by suitable retaining means to a stem
92 which is biased in an upwardly direction by spring 93. A cavity
94 on the upper side of the diaphragm is utilized for the
acceleration fuel provided by the diaphragm pump. In this instance,
the inlet and outlet of fuel to the space 94 is not shown for
convenience sake. Stem 92 is provided with a carrier bar 96 which
supports the metering rod 66. In the normal operation of the pump,
manifold vacuum acting in space 90 pulls the diaphragm down and
this permits the pumping space 94 to fill with fuel while at the
same time drawing the metering rod 66 down into the metering jet 64
to reduce the annular clearance between the taper of the metering
rod and the interior of the jet. Upon a reduction of vacuum, as
would come about if throttle 88 were opened more widely, spring 93
overcomes the vacuum and causes the diaphragm to move upwardly so
that fuel is discharged into the carburetor from the accelerating
pump and at the same time, metering rod 66 is drawn up to provide a
greater annular clearance, thus providing additional fuel to the
carburetor for enrichment purposes. This is commonly referred to as
step-up.
Referring now to FIG. 4, it will be seen that conduit 20
communicates with air metering means in the form of a metering rod
100 which is provided at its lowermost extremity with a reverse
taper metering section. As with the metering rods described
earlier, rod 100 moves up and down under the influence of biasing
spring 102 and carrier plate 40. Adjustment screw 48 makes final
calibration adjustments of the relationship of metering rod 100
with its metering orifice. Air is provided from the interior of
compensating unit 10 to the metering zone by way of a passage
104.
Returning to FIG. 7, there is shown an additional engine control
function connected by a pipe 110 to passage 86. Pipe 110
communicates with a vacuum motor 112 which is shown as a diaphragm
unit but which might be a piston-type device. Diaphragm unit 112 is
provided with a diaphragm 114 biased in a direction away from the
source of vacuum by a spring 116. An operating arm 118 is attached
to the opposite side from the biasing spring to the diaphragm. Arm
118 can be connected to any selected function, as for example, the
spark advance of the ignition distributor or to the shift mechanism
of an automatic transmission. Each of these engine functions may be
required to alter operating characteristics as the vehicle is
driven into changing conditions of altitude or temperature. Thus,
the vacuum motor 112 which receives a controlled vacuum signal
which is dependent upon the altitude and/or temperature can be made
to function in a desired and programmed manner. Although motor 112
is shown connected to the same system as the accelerator pump and
step-up of the carburetor, it could be divorced from that system as
would be obvious merely through the provision of a separate air
metering element corresponding to element 100 and a separate source
of vacuum together with a suitable connecting passage corresponding
to passage 20.
The foregoing description has described a system primarily for use
in a single barrel carburetor in which the altitude/temperature
compensating unit is separated from the carburetor and engine and
connected to the necessary components by means of flexible tubes or
hoses. It will be apparent that to the extent the
altitude/temperature unit controls carburetor functions, the unit
can be integrated with the carburetor structure and the various
hoses replaced with integral passages in the carburetor body
structure. In such an embodiment, the only remote locations
connected by tubes or hoses would be to the other engine functions
such as distributor vacuum motors and/or automatic transmission
control motors.
In the remaining figures of drawing, the basic concepts of the
invention are applied to a four-barrel carburetor and, for the most
part, these same concepts would be true of a two-barrel carburetor.
In making the description of the four-barrel carburetor, numbers
similar to that used in the single barrel carburetor will be used,
excepting that all numbers will be three-digit numbers in place of
mostly two-digit numbers used earlier, as for example, the number
14 will become 214, 20 will become 220, etc. A further difference
between the four-barrel embodiment and the single barrel embodiment
is that the passageways which were formerly separate conduits, such
as flexible rubber tubing, now are passages formed or drilled
integrally in the carburetor body and the altitude/temperature
compensation unit is also mounted directly on the carburetor
body.
Referring now to FIG. 8, there is shown the base of a compensating
unit 220 mounted on the body of a four-barrel carburetor 212. A
cover 223 is provided for covering up the operative mechanism of
the compensator unit. The four-barrel carburetor 212 has two
primary barrels and two secondary barrels. The primary barrels are
each equipped with an idle fuel system and a main fuel system while
the secondary barrels have only a single main fuel system each.
Since each of the fuel systems can be managed by single metering
pin, the unit 210 duplicates the metering capability of the
compensating unit 10 of FIG. 1 with the addition of one additional
capability for the secondary fuel nozzles. A passage 214
communicates at one end with the air horn of the carburetor and,
thus, with the space inside the air cleaner and its other end with
the interior of compensating unit 210. In this fashion, clean air
is supplied for all air metering functions. This last is shown also
in FIG. 10.
Also shown in FIG. 8 is a passageway 216 which extends from the
interior of unit 210 to a branch extending to each of the two main
nozzle wells indicated at 256. Similarly, a passage 218 is branched
to extend to the two idle fuel passages 277. A passage 213 extends
to a branching point where it separates and branches out to
secondary fuel wells 215. It is to be remembered that all of the
fuel passages and fuel systems in the four-barrel version are
substantially similar to the single barrel version shown in FIGS. 1
through 7. Principal difference being the secondary fuel nozzle and
secondary fuel well which are at least similar to the primary fuel
nozzle and well.
Multiple barrel carburetors are normally provided with a pair of
metering rods 266 which cooperate with a metering jet similar to
jet 64 of FIG. 5. In the embodiment shown, the metering rod 266 is
controlled in part by a vacuum actuated piston 291 which receives
vacuum by wat of passage 286. The passage 286 communicates with the
intake manifold at a point beneath the throttle valve and
communicates also with a passage 220 which terminates in the
compensating unit 210 where an air metering pin controls the
quantity of air that is admitted into the vacuum passage 286 to
regulate the vacuum therein.
Referring now to FIG. 13, vacuum piston 291 can also be forced into
an upward position by means of a rod 300 which is driven by a leaf
302 which in turn is driven by a cam 304 on throttle shaft 306.
Thus, when throttle shaft 6 is rotated in a direction to open the
throttle, the cam 304 will move leaf 302 upwardly to in turn move
rod 300 which in turn will lift the metering pin 266 the desired
amount. In this manner, additional fuel can be delivered to the
main nozzles of the primary barrel as the throttles are opened. On
the other hand, if there is a sudden loss of manifold vacuum, as
sometimes occurs, piston 291 is allowed to rise upwardly and this
in turn lifts the metering rod 266 to provide the fuel enrichment
usually desired under these conditions.
Referring now to FIGS. 14 through 18, the compensating unit 210 is
quite similar to the unit 10 of FIGS. 2, 3 and 4, and contains all
of the same features, although housed somewhat differently. Air
conduits 213, 214, 216, 218 and 220 are connected to a carburetor
as shown in FIG. 8. Plate 240 is hinged at 242 and carries a
plurality of adjustment screws. Adjustment screw 236 makes any
needed corrections or adjustments to the contact with barometric
and/or temperature capsule 230. Adjustment screws 244, 246 and 248
are provided to position metering pins in the same fashion as
screws 44, 46 and 48 of FIGS. 3 and 4. Additionally, biasing
adjustment screw 250 adjusts tension on a spring in the same manner
as does screw 50 of FIG. 3. A further metering screw 245 is
provided to adjust the position of the metering pin which controls
the air delivered to the secondary fuel nozzles by way of conduit
13 and, as explained earlier, this is in the same manner as the air
delivered to the primary main nozzles.
In FIGS. 8 through 19, the 200 series of numbers corresponds as
nearly as possible with the below 100 series of numbers in FIGS. 1
through 7. It is believed unnecessary to give a detailed
description of the various features of FIGS. 8 through 19 and a
brief description is believed sufficient.
FIG. 14 corresponds roughly to FIG. 2, with the exception that it
is configured for a multibarrel carburetor. FIG. 15 corresponds to
FIG. 3. FIG. 16 illustrates a means by which spring 251 can be
adjusted by means of screw 250 and also by means of a screw 253
which adjusts the bottom end of the spring 251. In a similar
manner, spring 251 can be adjusted by an external means, which, for
example, could be a temperature sensor 255 in communication with an
exhaust manifold 257 which by means of a thermal motor 259, can
adjust an arm 261 which in turn will adjust the spring 251. Thus,
as exhaust temperature changes, the bias on spring 251 will be
adjusted in accordance with engine operation to put a bias on plate
240 to thereby change the quantity of air bled into the fuel
metering systems in accordance with engine demands. FIG. 11 is
similar to FIG. 5, excepting that the fuel nozzle 271 is a
secondary main fuel nozzle and in all other respects, the air bleed
into the nozzle is similar to that of FIG. 5. FIG. 13 is similar to
the righthand portion of FIG. 7 in that it shows a means for
raising or lowering a metering rod 266 in accordance with the
position of the throttle. 306 is the primary throttle shaft and 304
is a cam on that shaft. The cam in turn moves a lever 302 which
raises and/or lowers a rod 300 which is in direct connection with
metering rod 266.
FIGS. 17 and 18 illustrate metering pins moved by plate 240. In
FIG. 17 metering pin 320 functions in the same manner as metering
pin 100 of FIG. 4 to reduce the quantity of air flowing through a
passage 322 which communicates with a motor such as diaphragm motor
112 of FIG. 7. In a similar manner, metering rod 280 of FIG. 18
functions much the same as metering rod 80 of FIG. 4 to increase
the amount of air bled into the fuel system when plate 240 rises
under the influence of reduced barometric pressure or increased
temperature and rod 280 can be adjusted as desired by screw 250 and
its associated nut.
From the foregoing it can be seen that a capsule sensitive to
barometric pressure and/or temperature can be utilized to adjust
air bleeds into various operative functions of an engine to thereby
control said functions as a result of changes in atmospheric
pressure and/or temperature. In general, it can be said that
whether the engine be equipped with a one-barrel, two-barrel, or
four-barrel carburetor, the air bleeds can be compensated in such a
manner that, with increasing altitude or decreasing barometric
pressure, the fuel supplied to the carburetor will be reduced in
accordance with such change and other operative functions of the
vehicle such as transmission shifts and/or spark advance or retard
can be accomodated in such a manner as to achieve optimum operation
of the engine and vehicle.
* * * * *