Fuel conservation system for internal combustion engines

A system is provided for varying the number of active cylinders in a multi-cylinder internal combustion engine, in response to the operating requirements of the engine. When the engine reaches that part of its operating range where the torque requirement is such that operation of all of the cylinders is not required to provide adequate and efficient power, certain cylinders are rendered inactive, thereby reducing the fuel consumed by the engine. A control system is provided which, upon sensing a reduced torque requirement upon the engine, activates a switch which de-energizes the spark generating electrodes of certain cylinders, and concurrently activates solenoid valve means whereby fuel vapor in the deactivated cylinders may be bypassed through the cylinders and returned to the fuel supply system of the engine for later use. In one embodiment of the system, novel spark producing means is provided which includes the fuel bypass valve means. The spark producing means is so constructed that it may be substituted for a conventional spark plug of an internal combustion engine thereby providing for simple and economical installation of the fuel conservation system upon existing internal combustion engines.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to methods and apparatus for conserving 
fuel in, and extending the operating life of, internal combustion engines 
and more particularly, but not by way of limitation, to methods and 
apparatus for selectively deactivating one or more cylinders of a 
multi-cylinder internal combustion engine in response to the torque 
requirements on said engine thereby reducing the fuel consumption of the 
engine. 
2. Description of the Prior Art (Prior Art Statement) 
The following statement is intended to be a Prior Art Statement in 
compliance with the guidance and requirements of 37 CFR Sections 1.56, 
1.97 and 1.98 and with Section 609 of the Manual of Patent Examining 
Procedure. 
U.S. Pat. No. 2,078,178 to Johnson shows a device where fuel is bypassed 
from the combustion chamber concurrent with a deactivation of the spark 
plug in that chamber. It will be noted, however, that the Johnson device 
is very dissimilar from the present invention, the principle dissimilarity 
being that the fuel bypass and ignition deactivation of the Johnson 
apparatus is not automatically provided in response to engine speed, 
engine torque or any other engine operating parameter. The fuel bypass and 
ignition deactivation of Johnson is provided by manual means only. That 
is, the valve 22 providing for fuel bypass is activated manually by 
turning the thumb screw 23 thereby moving the valve 22 to an open or 
closed position. When the valve 22 is moved to an open position, the 
extension 24 is concurrently moved into electrically grounding contact 
with the conductor 25 which is attached to the spark plug 15 thereby 
grounding out the plug and preventing sparking of the same. Furthermore, 
the Johnson device does not include any means by which fuel bypass can be 
accomplished in a conventional engine through an arrangement similar to 
the "spark valve" of the present invention. 
U.S. Pat. No. 2,544,463 to Mallory shows a system for cutting off the fuel 
supply to an engine in conjunction with cutting off the electrical 
ignition to the engine. 
A multitude of systems are provided in the prior art for controlling the 
ignition of an engine in response to engine speed. An example of such 
systems is U.S. Pat. No. 3,022,777 to McCloy. McCloy describes an internal 
combustion engine speed governing means which includes a normally open 
grounding circuit closable by a speed sensitive switch and communicating 
electrically with a commutator ring rotatable with the distributor which 
directs spark inducing circuits to the several cylinders of the engine. A 
conductor system is provided which connects the ring to such individual 
spark inducing circuits to cause intermittent interruption of the 
grounding circuit to that there is excluded therefrom, selected spark 
inducing circuits. In this way, selective cylinders are rendered 
temporarily inoperative in response to the engine speed, and the remaining 
cylinders continue to operate. By this means, the speed of the engine is 
governed. 
Other systems in the prior art similar to McCloy, showing such ignition 
control are U.S. Pat. Nos. 3,974,805 to Kondo; 3,863,616 to Wood; 
3,884,203 to Cliffgard, 3,703,889 to Bodig; 3,158,143 to Heidner, 
2,656,827 to Conover; 1,624,975 to Reece; 1,603,744 to Burton; 1,390,376 
to Oglesby; and 970,794 to Carlson. 
A more refined ignition control system responsive to a combination of 
engine parameters is that shown in U.S. Pat. No. 4,003,354 to Canup. One 
of the parameters to which the Canup system is responsive is the torque 
load on the engine as shown by the torque sensor 48 of Canup. 
Several devices have been seen in the prior art which provide means for 
bypassing unused fuel through a combustion cylinder of an engine. These 
have principally been found in the diesel engine art where electrical 
ignition means is not used. For example, U.S. Pat. No. 3,919,986 to Goto 
shows a system by means of which the output of a diesel engine is 
controlled by discharging a portion of the combustible mixture from the 
combustion chamber prior to the ignition thereof. By this means, the 
output of the Goto device is controlled. A similar concept is shown in 
U.S. Pat. No. 1,456,337 to Pullin. Additionally, U.S. Pat. No. 1,898,602 
to Stamsvik shows a system wherein the flow of fuel to certain cylinders 
of a multi-cylindered engine is cut off at low engine speeds. 
It is seen therefore that none of the apparatus of the prior art include a 
system wherein the explosive charge of selected cylinders is bypassed 
through the cylinder and returned to the fuel supply system, automatically 
in response to variable engine parameters. 
SUMMARY OF THE INVENTION 
A system is provided for varying the number of active cylinders in a 
multi-cylinder internal combustion engine, in response to the operating 
requirements upon the engine. When the engine reaches that part of its 
operating range where the torque requirement is such that operation of all 
of the cylinders is not required to provide adequate and efficient power, 
certain cylinders are rendered inactive and the fuel flow to those 
cylinders is recycled to the fuel supply system, thereby reducing the fuel 
consumed by the engine. A control system is provided which, upon sensing 
the low torque requirement upon the engine, activates a switch which 
de-energizes the spark generating electrodes of certain cylinders, and 
concurrently activates solenoid valve means whereby unburned fuel in the 
deactivated cylinders may be bypassed through the cylinders and returned 
to the fuel supply system of the engine for later use. Novel spark 
producing means is provided which includes the fuel bypass valve means. 
The spark producing means is so constructed that it may be substituted for 
a conventional spark plug of an internal combustion engine, thereby 
providing for simple and economical installation of the fuel conservation 
system upon existing internal combustion engines. 
It is therefore a general object of the present invention to provide an 
improved fuel conservation apparatus for internal combustion engines. 
A further object of the present invention is to provide means for 
automatically controlling combustion in preselected cylinders of a 
multi-cylindered engine in response to engine torque requirements. 
Another object of the present invention is to provide means for 
concurrently deactivating the ignition system of a cylinder while 
bypassing a combustible fuel mixture through the cylinder. 
Yet another object of the present invention is the provision of apparatus 
adaptable to a conventional engine, by means of which ignition of the 
cylinders is controlled while concurrently bypassing the combustible 
mixture through that orifice in the engine which conventionally houses the 
ignition spark producing means. 
Other and further objects, features and advantages of the present invention 
will be readily apparent to those skilled in the art upon a reading of the 
description of preferred embodiments which follows when read with 
reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
Referring now to the drawings and particularly to FIG. 1, the fuel 
conservation system of the present invention is shown and generally 
designated by the numeral 10. The system 10 includes combustion chambers 
12, 14, 16, 18, 20, 22, 24 and 26. Each of the combustion chambers is 
connected to an intake manifold 28 by means of an intake passage 30. The 
intake manifold 28 is connected to a carburetor 32 by means of a fuel 
vapor supply line 34. Non-vaporized fuel is supplied to the carburetor 32 
by means of a fuel inlet line 36 which is also connected to a fuel storage 
tank (not shown). Air, for mixture with the fuel to provide a combustible 
fuel vapor is provided to the carburetor 32 by means of the air inlet 38, 
the flow of such air being controlled by throttle valve 40. It will be 
noted that all of the components described to this point are those which 
are typically found in an internal combustion engine. Also electrical 
spark ignition of the combustible fuel vapor in each of the combustion 
chambers is provided by an ignition system which is controlled by means of 
the distributor 42. 
The improvement on the conventional internal combustion engine which is 
provided by the present invention is a system which, in response to a 
preselected value of engine torque load, acts to conserve the fuel 
consumed by the engine by deactivating the ignition means of preselected 
cylinders, while concurrently bypassing the fuel vapor mixture through 
said cylinders and returning the same to the fuel supply system. This is 
accomplished in the following manner. 
Conventional timing control electronics 44 are provided which include 
engine torque load sensing means and control apparatus responsive thereto 
for activating an electronic switch means 46 when the engine torque load 
reaches a preprogrammed operating range. In an automobile, for example, 
more torque is required to accelerate from zero velocity to cruising spped 
than is required to maintain cruising speed once it is attained. The 
timing control electronics 44 of the present invention therefore includes 
a torque load sensing means and control apparatus responsive to the 
sensing means, when the sensing means indicates a certain lower magnitude 
of torque load, to activate the switch means 46 which deactivates the 
ignition system of cylinders 12, 14, 16 and 18 while concurrently 
providing for bypass of the fuel vapor from those cylinders, as will be 
explained further below. 
The torque load sensing means of the timing control electronics 44 can be 
of any of a number of conventional designs well known to those skilled in 
the art. A particularly appropriate torque sensing means for the present 
invention includes signal input means 43 and 45 which provide electrical 
inputs corresponding to throttle position and vehicle speed, respectively. 
Additionally, input means 47, connected to the distributor 42, provides an 
input signal corresponding to the engine RPM. 
Torque, as well as each of those variables upon which torque load is 
dependent, has an influence upon the fuel economy of the engine. At low 
torque levels the individual cylinders of a multicylinder engine are not 
operating at their most efficient level. By reducing the number of 
operating cylinders, those cylinders which are operating are required to 
supply a greater portion of the torque required, and they operate in a 
more efficient manner thereby increasing the fuel economy of the engine. 
A sensing transducer (not shown) connected to the input means 43 for 
sensing throttle position would preferrably be of the linear displacement 
type. The throttle position is an important variable upon which the amount 
of fuel supplied to the engine is dependent. 
A sensing transducer (not shown) connected to the input means 45 for 
sensing vehicle speed is preferrably a rotating optical or magnetic 
transducer coupled to a speedometer cable of a conventional vehicle or to 
another vehicle component whose rotational speed is directly related to 
vehicle speed, such as an output shaft from a transmission. 
The timing control electronics 44 is designed to sense the torque 
requirement of the engine based upon the input signals described above. 
Depending upon the sophistication and accuracy required, other vehicle 
parameters having an influence on engine torque requirements may be 
accounted for by providing appropriate sensing means and by appropriate 
modification of the timing control electronics 44. 
The ignition system connecting the distributor 42 to the spark inducing 
means of each of the cylinders includes spark plug wires 48, 50, 52 and 54 
leading respectively to cylinders 20, 22, 24 and 26. Those leads are 
connected to conventional spark producing means in a manner well known to 
the prior art. Additionally, spark plugs wires 56, 58, 60 and 61 are 
provided connecting the distributor 42 respectively to the spark producing 
means of cylinders 12, 14, 16, and 18. The switch means 46 is 
interconnected with spark plug wires 56, 58, 60 and 61 at a location 
intermediate the distributor 42 and the respective spark producing means 
of the cylinders, and is interconnected with the spark plug wires in such 
a manner that ignition signals from the distributor 42 can be interrupted 
by activation of the switch means 46. 
The electronic switch means 46 contains four individual switches (not 
shown) connected to timing control electronics 44 by connecting means 62, 
63, 64 and 65, and responsive to signals from timing control electronics 
44 to de-energize the spark producing means of cylinders 12, 14, 16 and 18 
by interruption of the signals carried by spark plug wires 56, 58, 60 and 
61 respectively. De-energization is preferrably accomplished by grounding 
of the spark plug wires. In engines having an electronic ignition system, 
however, de-energization may be accomplished by controlling the low 
voltage input (not shown) to the distributor 42. 
The timing control electronics 44 also controls the bypass system for the 
unused fuel vapor from cylinders 12, 14, 16 and 18, in the following 
manner. Each of the cylinders 12, 14, 16 and 18 includes a fuel bypass 
means 66, 68, 70 and 72, respectively. Each of the fuel bypass means is in 
fluid communication with its respective cylinder and with a fuel return 
line 74. By means of the fuel return line 74, unused fuel vapor is 
returned to the carburetor 32 as shown in solid lines, or alternatively, 
may be returned to the intake manifold 28 by means of the alternate return 
line 76, as shown in phantom lines. 
It will be appreciated that depending upon the particular application of 
the fuel conservation system of the present invention, it may be desired 
to return the unused fuel vapor to one or more of several points within 
the fuel supply system. For example, if the operation of the engine is 
such that the combustible fuel vapor mixture passes through the cylinder 
12, 14, 16 and 18 relatively unchanged, that is retaining the droplets of 
fuel suspended in the air, the fuel may be directly returned to the 
cylinders for combustion by means of either of the fuel return lines 74 or 
76 as shown. However, if, in passing through the engine, the fuel vapor 
mixture begins to deteriorate substantially, that is if the fuel droplets 
coalesce to the point that the finely dispersed fuel and air mixture is 
lost, it may be necessary to return the unused fuel to a point upstream of 
the carburetor, i.e., to the fuel storage tank (not shown) upstream of the 
fuel inlet line 36. In this latter type of fuel return system the fuel 
vapor should be passed through a condensor (not shown) located 
intermediate of the fuel return line and the fuel storage tank (not 
shown). 
In the various embodiments of a fuel return system described above, 
particularly the first two where fuel vapor is recycled to the carburetor 
or intake manifold, it is often desirable to include a conventional surge 
tank 77 to smooth out the pressure fluctuations in the fuel return system. 
Each of the fuel bypass means 66, 68, 70 and 72 is controlled by the timing 
control electronics 44 by means of signals transmitted through electrical 
connecting means 78, 80, 82 and 84, respectively. 
The operation of the fuel conservation system 10 can be described by the 
following example. In an automobile having a conventional multi-cylindered 
internal combustion engine, the timing control electronics 44 is set so 
that when the automobile reaches a cruising velocity and the torque load 
upon the engine falls below a sensed predetermined level, signals are sent 
to the switch means 46, thereby de-energizing the ignition means of one or 
more of the cylinders 12, 14, 16 and 18. Concurrently, signals are sent to 
the corresponding fuel bypass means 66, 68, 70 and 72, thereby activating 
the same and allowing the fuel vapor from the de-energized cylinders to be 
passed through the fuel bypass means into the fuel return lines 74 so that 
it may be recycled within the fuel supply system. In this manner, when the 
load requirements upon the engine are such that all eight of the cylinders 
are not required, some of the cylinders are taken out of operation thereby 
effectively providing an engine with a lesser number of operating 
cylinders, characterized by the attendant fuel economy. When the torque 
requirements on the engine rise above the preset level, for example when 
the automobile begins to climb a hill, the timing control electronics 44 
once again sends signals to the switch means 46, thereby reactivating the 
ignition means of the previously de-energized cylinders. Concurrently 
signals are sent to the fuel bypass means, thereby closing the same so 
that all cylinders are once again in operation and the full power of an 
eight cylinder engine is provided. 
Referring now to FIG. 2, a presently preferred embodiment of the fuel 
bypass means of the present invention is shown in a partially schematic 
manner and is generally designated by the numeral 100. The fuel bypass 
means 100 will hereinafter be referred to as the spark valve 100. The 
spark valve 100 is so constructed that it may be placed in a conventional 
internal combustion engine in place of the conventional spark plug. The 
spark valve 100 includes a casing 101 which threadedly engages a 
conventional spark plug orifice (not shown) by means of its threaded end 
102. In structural and electrical connection to the threaded end 102 is a 
grounded electrode 104 which is similar to the analogous component of a 
conventional spark plug. Spaced from the grounded electrode 104 is a high 
voltage electrode 106 which is encased in an electrode insulator 108. An 
end of the high voltage electrode 106 is provided with connector means 110 
by means of which the high voltage electrode 106 is electrically connected 
to one of the spark plug wires 56, 58, 60 or 61. For the sake of brevity, 
further connections of the spark valve 100 with associated components of 
the fuel conservation system 10 will be referred to only with respect to 
the cylinder 12. The connector means 110 is therefore connected to the 
spark plug wire 56. The components of the spark valve 100 discussed to 
this point are essentially the same as the analogous components of a 
conventional spark plug. 
The high voltage electrode 106 and the electrode connector 108 pass through 
an orifice 112 in the side of the casing 101. It is necessary that the 
electrode insulator 108 sealingly engage the orifice 112 so that high 
pressure gases cannot escape therebetween, as will be further shown below. 
The electrode insulator 108 is held within the casing 101 by means of a 
supporting protrusion 114. Internal to the casing 101 at an intermediate 
portion thereof is a dividing wall 116 which includes a valve seat 118. 
The casing 101 also includes a second end 120. Held within the second end 
120 and the dividing wall 116 is a valve member generally designated by 
the numeral 122 which includes a valve head 124 and a valve stem 126. At 
the end of the valve stem 126, opposite the valve head 124, is attached a 
valve retainer 128 which forcibly engages a resilient valve spring 130 
located external of the casing 101 between the retainer 128 and the second 
end 120. The valve head 124 intimately contacts the valve seat 118 when 
the valve is in a closed position. The valve member 122 will normally be 
retained in a closed position by means of the resilient valve spring 130. 
The valve spring 130 is a helical spring which is in a state of 
compression thereby forcibly urging the valve head 124 into contact with 
the valve seat 118. 
The valve member 122 and the dividing wall 116 separate the interior of the 
casing 101 into a first chamber 131 and a second chamber 133. 
When it is desired to open the valve member 122 and permit fuel vapor to be 
bypassed through the spark valve 100, solenoid windings 132 are energized. 
Within the windings 132 is located a solenoid core 134 which is connected 
to the valve stem 126. When windings 132 are energized, the core 134 and 
the valve stem 126 are urged downwardly so that the valve head 124 moves 
away from the valve seat 128. The solenoid windings 132 are connected to 
conventional timing control electronics 44 by means of the electrical 
connecting means 78. It is understood that the solenoid windings 132 and 
core 134 are shown only in a schematic manner. 
Communicating with the second chamber 133 is a bypass orifice 136 leading 
to the fuel return line 74 of FIG. 1. The bypass orifice 136 may also be 
referred to as a fluid outlet. Intermediate of the orifice 136 and the 
return line 74 is a one-way check valve 138 for allowing flow of unburned 
fuel vapor from the orifice 136 to the return line 74. 
Seal means 140 are disposed between the valve stem 126 and the second end 
120 of the casing 101 to prevent the escape of high pressure exhaust gases 
around the valve stem. 
In the operation of the spark valve 100, when the valve member 122 is in a 
closed position--that is, when the valve head 124 is intimately contacting 
the valve seat 118--the spark valve 100 operates in the same manner as 
does a conventional spark plug. That is, a spark is produced between the 
grounding electrode 104 and the high voltage electrode 106, thereby 
igniting fuel in the cylinder 12 and powering the engine. 
When the voltage to the electrode 106 is interrupted by the switch means 46 
as controlled by the timing control electronics 44, however, the solenoid 
windings 132 are concurrently energized by a similar signal from the 
timing control electronics 44 by means of the electrical connecting means 
78, thereby causing the valve head 124 to move away from the valve seat 
118 and permitting fuel from the cylinder 12 to be bypassed through the 
spark valve 100 and to the fuel return line 74. The flow of fuel vapor 
from the cylinder 12 to the fuel return line 74 is by means of the 
following path. Fuel vapor from the cylinder 12 moves into the casing 101 
through the fluid inlet at its threaded end 102 as indicated by the arrow 
142. The fuel then flows through the annular opening between the valve 
seat 118 and the valve head 124, thence through the bypass orifice 136, 
and through the check valve 138 to the fuel return line 74. 
The amount of fuel vapor which can flow through the spark valve 100 is a 
function of the cross-sectional area of the flow passage. Therefore, the 
bypass orifice 136 will desirably be as large as possible. This bypass 
orifice is intended to be shown only in a diagramatic fashion, and it is 
understood that it preferably is constructed in such a manner as to 
provide the least resistance to flow of fuel vapor from the cylinder 12 to 
the fuel return line 74. The specific construction, of course, depends 
upon the physical structure of the engine to which the spark valve 100 is 
added. 
It is also noted that the broad concept of the fuel conservation system 10 
includes bypass means 66 constructed to be completely separate from the 
spark producing means of the cylinder 12. This is accomplished, in one 
form, by an additional valve in the cylinder head. It can also be 
accomplished by means of a T-shaped manifold having a first end for 
threadedly engaging a conventional spark plug hole, a second end connected 
to a solenoid operated bypass valve and a third end having disposed 
therein a spark plug of conventional design. The specific embodiment to be 
used for a given application will depend upon the performance requirements 
of the engine. 
Thus, the apparatus for fuel conservation in an internal combustion engine 
of the present invention is well adapted to carry out the objects and 
attain the ends and advantages mentioned, as well as those inherent 
therein. While certain embodiments of the invention have been described 
for the purpose of this disclosure, numerous changes in the construction 
and arrangement of parts can be made by those skilled in the art, which 
changes are encompassed within the spirit of this invention as defined by 
the appended claims.