PATENT SPECIFICATION
`
`(11)
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`1447 791
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`(21) Application No. 48106/73
`(31) Convention Application No.
`2 250 756
`
`(22) Filed 16 Oct. 1973
`
`(32) Filed 17 Oct. 1972 in
`
`..
`
`"
`
`(33) Germany (DT)
`(44) Complete Specification published 2 Sept. 1976
`(51) INT. CL.2 F02M 51/00
`F02D 5/02
`F02P 5/08
`(52) Index at acceptance
`G3N 251 286 287 BH
`FIB 2B12 2B13E 2Bl3F 2B13G 2B13M 2Bl5 2B16E
`2B16G 2Bl 2B4 2B7A 2D4Bl
`
`(54) IMPROVEMENTS IN AND RELATING TO INTERNAL
`COTv1BUSTION ENGINES HAVING ELEC'fRICAI.L Y
`CONTROLLED PETROL INJECTION
`
`(71) We, RoBERT BoscH GMBH, a
`German Company, of Postfach 50, 7 Stutt·
`gart 1, Gern1any, do hereby declare the in·
`vention, for which we pray that a patent
`5 may be granted to us, and the method. by
`which it is to be performed, to be particu(cid:173)
`larly described in and by the following
`statement:
`The invention relates to internal com-
`10 bustion engines h_aving electrically con(cid:173)
`trolled petrol injection.
`The invention is concerned with engines
`having injection systems of the type having
`at least one injection valve which is opened
`15 in synchronism with the rotation of the
`crankshaft and, by means of an electrical
`control system, is maintained open for a
`period dependent upon the pressure of the
`intake air downstream of the throttle valve
`20 or upon the flow of the intake air of the
`internal combustion engine, and having
`also a device for acting upon the internal
`combustion engine during overrun.
`Petrol injection systems for motor-vehicle
`25 internal combustion engines are already
`known in which for overrun operation,
`when, in spite of the throttle valve being
`closed, for example during downhill travel
`or braking, the internal combustion engine
`30 operates at a speed substantially greater
`than the idling speed, a circuit breaking
`device is provided which, in this operating
`state, either prevents the triggering of elec(cid:173)
`trical opening pulses and thereby blocks
`35 the control system or does not transmit the
`opening pulses provided by the control
`system to a power stage connected in series
`with the solenoid valve or valves. The cir(cid:173)
`cuit remains broken until the engine speed
`40 falls below a minimum speed providing a
`rufficient safety margin above the idling
`speed. Since injection does not take place
`during overrun, noxious gases cannot be
`emitted. However, the fact that, should the
`4S off period be prolonged, both the com·
`
`the exhaust
`bustion chamber und also
`system of the internal combustion engine
`may cool down substantially, has proved a
`disadvantage. The result is that, on the
`next acceleration operation, not only a sub· 50
`stantial power drop may occur, but also a
`substantial increase in the noxious hydro(cid:173)
`carbo~ content of the exhaust gas can be
`expected.
`regulator has 55
`A differential pressure
`therefore already been proposed which re(cid:173)
`sponds to the substantial pressure drop in
`the inlet manifold on the sudden closure of
`the throttle valve and which by-passes a
`small, slowly reducing amount of air past 60
`the closed throttle valve sufficient to main(cid:173)
`tain sufficiently high-energy combustion in
`the
`individual cylinders of
`the
`internal
`combustion engine during overrun.
`An electromagnetically actuated device is 65
`also
`known
`having
`a
`longitudinally
`movable shut-off device which, in the nor·
`111al position, projects into a by-pass duct
`by-passing the throttle valve and opens this
`duct to admit auxiliary air when a switch 70
`actuable by means of the throttle valve is
`closed when the throttle valve is in the id(cid:173)
`lim': position, and simultaneously an engine(cid:173)
`speed dependent switch is closed which
`switches to its open position on a fall in 71
`sPeed of the internal combustion engine,
`when the speed falls below a minimum
`value which
`is. however,
`substantially
`greater than the idling speed. The auxiliary
`air thus provided during overrun ensures 80
`sufficiently high energy of combustion. As(cid:173)
`sociated with this, however, is a substantial
`impairn1ent of the braking action of the in(cid:173)
`ternal combustion engine when operating
`on overrun.
`In accordance with the present invention
`there is provided an internal combustion
`engine having an electrically controlled,
`petrol injection system comprising at least
`one injection valve which is arranged to be 90
`
`85
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`BOSCH-DAIMLER EXHIBIT 1003
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`1447 791
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`80
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`opened in synchronism with the rotation of
`the crankshaft and, by means of an elec(cid:173)
`trical control system, to be maintained
`open for a period dependent upon the pres-
`S sure of the intake air downstream of a
`throttle valve of the engine or upon the
`flow of the intake air of the internal com(cid:173)
`bustion engine, a device for acting upon
`the internal combustion engine during over-
`10 run which devi~e comprises a control valve
`for auxiliary air arranged in a circuit by(cid:173)
`passing the engine throttle valve, and a
`spark
`timing device which
`is actuable
`together with the control valve and which
`15 is arranged to retard the ignition from its
`basic setting by 10° to 20° so that it
`occurs between 15° to 25° A.T.D.C.
`The invention will be described further,
`by way of example, with reference to the
`20 accompanying drawings, in which:-
`Fig. 1 shows a general arrangement of
`an internal combustion engine having an
`inlet manifold injection system;
`Figs. 2 to 7 are block circuit diagrams of
`25 electrical control systems
`for an elec(cid:173)
`tromagnetically actuable auxiliary air valve
`and an electromagnetically actuable spark
`timing device; and
`Figs. 8 to 10 show various embodiments
`30 in which the partial vacuum produced in
`the inlet manifold of the internal com·
`bustion engine is used as a servo force to
`actuate an auxiliary air valve and a spark(cid:173)
`timing adjusting element.
`internal
`35 The
`four-cylinder four-stroke
`combustion engine 10 shown in Fig. 1 is
`provided with a conventional high-tension
`ignition system
`including· four sparking
`plugs 11, each of which is associated with
`40 a respective cylinder of the internal com(cid:173)
`bustion engine. In the immediate vicinity of
`the inlet valves (not illustrated) of the in(cid:173)
`ternal
`combustion
`·engine
`an
`elec(cid:173)
`tromagnetically actuable injection valve 13
`AS i:vmounted· on, each oC the· branch- con(cid:173)
`nections of the inlet manifold 12 leading to
`the individual cylinders. Fuel is fed to each
`injection valve via a respective fuel line 14
`from a distributor 15. The fuel in the dis-
`50 tributor and in the fuel ·lines 14 is drawn
`from a fuel storage tan~ 1_8 by means of a
`pump 16 driven by an electric motor and
`is delivered to a pressure ;,regulator 17
`provided upstream of the distributor 15 for
`55 the purpose of maintaining the pressure of
`the fuel for delivery to the injection valves
`at a substantially constant value of ap-
`proximat~ly 2 atmosph~~es .. _
`. _
`Each of the injection valves 13 includes
`110 a solenoid winding (not shown), one end of
`which is connected to earth, while the
`other end of each of the windings is con(cid:173)
`nected by means of connecting leads 19 to
`a respective one of four resistors 20. The
`~5 resistors 20 are jointly connected to the
`
`collector of a power transistor 21, which is
`supplied with square-wave control pulses
`23 at each revolution of the crankshaft 24
`from an eJ~ctronic control system
`(de·
`scribed further below) by way of a trans- 70
`istor amplifier 22, the control system supp(cid:173)
`lying a current which opens the injection
`valves 13 for the duration of these pulses.
`The fuel injection quantity supplied to the
`inlet manifold and thence to the cylinders 7 5
`at each injection operation is proportional
`to
`the opening duration and must be
`adjusted according to the relevant oper(cid:173)
`ating state of the internal combustion en·
`gine.
`The control system 25, whose function it
`is to do this, is outlined in broken lines in
`Fig.
`1 and
`essentially
`comprises
`a
`monostable switching circuit consisting of a
`first switching transistor T1 of the PNP 85
`type and a second transistor T2 of the
`same type. The emitters of both transistors
`are connected by way of a positive supply
`line 26 to the positive pole of a motor
`vehicle battery (not shown) having a rated 90
`voltage of 12.6 volts, and serving as the
`operating current source. The collector of
`the first transistor Tl is connected by
`means of a load resistor 27, and the collec-
`tor of the second transistor T2 is con- 95
`nected by means of a load resistor 28, to a
`common negative supply line 29, which is
`connected to earth and to the negative pole
`of the vehicle battery. When the switching
`circuit 25 is in the static state, transistor 100
`T1 is maintained conductive by way of the
`resistor 30 which connects its base to the
`negative supply line 29; transistor T2 is
`then blocked. The unstable switching state
`of the switching circuit determining the 105
`opening duration of the solenoid valves 13
`is intiated when a cam 31, rotating at half
`the crankshaft speed, pushes a switch con-
`tact arm 32 associated with the cam 31 in
`opposition to the force of a restoring 110
`spring against its opposite contact con(cid:173)
`nected to the positive supply line 26 and
`thereby connects a control capacitor 33,
`which by that time has been charged by
`way of a resistor 35 to the positive supply 115
`line 26, through its negatively charged elec(cid:173)
`trode to the positive supply line. Transistor
`T1 is thereby blocked; transistor T2 and
`with
`it also
`the power
`transisto; 21,
`become conductive and the solenoid valves 120
`13 are opened. The solenoid valves close
`again when transistors T1 and T2 in the
`monostable switching circuit revert to their
`initial state.
`This instant is dependent upon the in- 125
`ductance of a primary winding 37 included
`in the collector circuit of transistor ·T2 and ,
`forming, together with a secondary winding
`38 and an adjustable iron core 39, a trans(cid:173)
`former. The iron core 39 is connected by 130
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`1447 791
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`means of a linkage 40 to the diaphragm of
`a pressure element 41, which is connected
`to the inlet manifold 12 immediately down(cid:173)
`stream, in the suction direction, of the
`5 throttle valve 48, which is actuable by
`means of an accelerator pedal 36. The
`lower the absolute pressure in the inlet
`manifold, the further the pressure element
`pulls the iron core out from between the
`10 primary and secondary windings, thereby
`reducing the inductance.
`One end of the secondary winding 38 is
`connected by way of a diode 45 to the
`base of transistor T1, and its other end to
`15 the junction of two resistors 43, 44 con(cid:173)
`nected between the positive supply line 26
`and the negative supply line 29. As soon
`as the switch contact arm 32 engages its
`opposite contact and blocks transistor Tl
`20 by way of a diode 42, transistor T2 is able
`to supply a current through the primary
`winding 37, this current increasing at a rate
`inversely proportional to
`the inductance
`and inducing in the secondary winding 38
`25 a voltage which maintains transistor T2
`conductive independently of the subsequent
`position of the switch contact arm 32, until
`the current in the primary winding 37
`reaches approximately its saturation value.
`30 The induced voltage blocking transistor T1
`by way of diode 45 reduces as the satura(cid:173)
`tion value is approached and ultimately
`drops to such an extent that the negative
`base bias voltage set by means of resistors
`35 43, 44 predominates at transistor T1 and
`permits transistor Tl to revert to its initial
`conductive state. As soon as this occurs,
`the power transistor 21 is blocked and the
`injection operation ends.
`In this injection system, in order to be
`able to use the pressure converter, com(cid:173)
`prising the pressure element 41 and the
`variable-inductance
`transformer,
`to
`de(cid:173)
`termine the injection quantity even when,
`45 during overrun, the internal combustion en(cid:173)
`gine initially described is propelled, for ex(cid:173)
`ample, during downhill running or braking,
`by the mass of the vehicle at a speed
`which, in spite of the throttle valve being
`50 closed, is substantially greater than the id(cid:173)
`ling speed, an auxiliary air valve referenced
`50 in Fig. 1 is provided in a by-pass line
`which by-passes the throttle valve 48 and
`which includes two by-pass sections 57 and
`55 58. Furthermore, a spark timing device 51
`is provided,
`essentially comprising
`a
`mounting plate 54, rotatable about the
`camshaft 53 of the internal combustion en(cid:173)
`gine, for .~ contact breaker 55 cooperating
`60 with a four-throw contact breaker cam 56
`on the camshaft 53.
`A common control system 60 (Figs. 2 to
`7) is provided for actuating the. auxiliary
`air valve 50 and the spark timing device
`65 51. An electromagnet 61, connected to the
`
`40
`
`auxiliary air valve 50, and a second elec(cid:173)
`tromagnet 62 adapted to actuate the spark
`timing device 51, are connected to the out-
`put of this control system. In order to de(cid:173)
`tect the overrun state, units of information 7'J
`each represented by a small box in Figs. 2
`to 7 can be fed to the control system 60,
`for example, as shown in Fig. 2, by means
`of an engine speed transducer 63 and a
`throttle valve transducer 64, in which case 75
`the engine speed transducer may be in the
`form of a switch which, on a fall in the
`speed of the internal combustion engine,
`changes its switching state when the speed
`falls below a predetermined minimum 80
`speed, which is greater, however, than the
`idling speed, for example 1000 rpm. The
`transducer 64 may also be constructed as a
`switch, which can be connected
`to
`the
`throttle valve shaft and which changes its 85
`switching state when the throttle valve re(cid:173)
`verts to its idling position in which it sub(cid:173)
`stantially closes the inlet manifold 12 and
`the auxiliary air necessary
`to maintain
`combustion in the cylinders of the internal 90
`combustion engine
`is supplied by
`the
`auxiliary air valve 50 which then switches
`to its open position.
`As shown in Fig. 3, instead of an engine
`speed switch 63 .or in addition to an engine 95
`speed transducer, a gear position trans(cid:173)
`ducer 65 may be provided, which supplies
`a signal, dependent upon the gear engaged
`in a gearbox (not shown) connected to the
`internal combustion engine, to the control 100
`system 60, and which cooperates with a
`clutch position
`transducer 66, which
`provides a control signal when a clutch
`(also not shown), arranged between the in(cid:173)
`ternal combustion engine 10 and the gear- 105
`box, is operated.
`If the internal combustion. engine is con(cid:173)
`nected to an automatic gearbox, as shown
`in ~ig .. 4. a transducer 67 can be provided,
`whtch IS caused by the relevant switching 110
`stage to. deliver a control signal to the con-
`trol system 60.
`With reference to the block circuit dia(cid:173)
`gram shown in Fig. 5, the internal com(cid:173)
`bustion engine 10 incorporates .in its inlet 115
`manifold a pivotable diaphragm plate ac-
`ting as an air intake flow meter and con(cid:173)
`nected to. a switch 68 which changes its
`switching state at a presettable pivot angle
`y. In order to detect the overrun state, i.e. 120
`when the vehicle is driving the engine, it is
`also possible, as illustrated in Fig. 6, to
`provide, in addition to the throttle valve
`switch 64 connected to the throttle valve, a
`vehicle speed transducer 69 which changes 125
`its switching state when the speed v of the
`vehicle driven by the internal combustion
`engine 10 falls below a predetermined
`value.
`When the exhaust gases of the internal 130
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`combustion engine are passed through a
`thennal and/or catalytic reactor, which is
`not shown in the drawings, it is often de(cid:173)
`sired to heat such a reactor quickly during
`5 the warming-up phase of the internal com(cid:173)
`bustion engine and thereby cause it to
`operate. In such a case, when the internal
`combustion engine is cold, retardation of
`10 the spark can be effected not only during
`overrun but also during slow idling. For
`this purpose, as shown in Fig. 7, besides
`two
`transducers shown
`in Fig. 2.
`the
`namely, the engine speed transducer 63 de(cid:173)
`pendent upon the speed n of the internal
`15 combustion engine, and the throttle valve
`switch 64, an engine temperature sensor 70
`may be provided which, instead of the en(cid:173)
`gine speed switch 63, causes the control
`20 system 60 to retard the spark timing by
`means of the spark timing device 51 and
`at the same time to open the auxiliary air
`valve 50. In addition to the three trans(cid:173)
`ducers 63, 64. 70 mentioned, a fourth
`transducer 71 may be used to transmit
`25 other information to the control system 60.
`Such infonnation may, for example, relate
`to the temperature of a thermal and I or
`chemical reactor arranged in the exhaust
`system of the internal combustion engine.
`In the arrangement according to Fig. 8,
`the auxiliary air valve 50 and the spark
`timing device 51 are not actuated by
`means of an electromagnet 61 or 62, but
`is provided by
`the
`the servo power
`35 negative pressure created in the inlet man(cid:173)
`ifold 12 of the internal combustion engine
`when the throttle valve 48 is closed or nea(cid:173)
`rly closed. To control this servo power, a
`servo valve 75, connected to, the control
`40 system 60, is provided, which is actuated
`by means of an electromagnet (not illus(cid:173)
`trated in detail) and which, when this mag(cid:173)
`net
`is energised. connects a pressure
`element 76, connected to the auxiliary air
`45 valve 50, and a spark timing adjusting
`element 77, connected to the spark timing
`device 51, to the inlet manifold 12 down·
`stream of the throttle valve. 48 in the air
`intake direction.
`50 The pneumatically operated auxiliary air
`valve may.
`as
`illustrated very dia(cid:173)
`grammatically
`in Fig. 9, comprise
`two
`valve chambers 81 and 82 in a housing 80,
`the valve chambers 81 and 82 being
`55 separated from each other by a diaphragm
`83. The first valve chamber 81 accom(cid:173)
`modates a compression spring 84 abutting
`the diaphragm 83 and can be connected by
`means of a connecting pipe 85 to an input
`60 86 of the servo valve 75. The connecting
`line 58, included in the by-pass circuit,
`through which air extracted upstream of
`the throttle valve 48 can enter the circuit,
`is connected to the second valve chamber
`65 82. A pipe 87, used instead of the air out-
`
`let pipe referenced 57 in Fig. 1, is inserted
`inside the second valve chamber 82 far en(cid:173)
`ough to enable the auxiliary air to be cut
`off by means of a valve plate 88 provided
`at the centre of the diaphragm 83 when 70
`the first valve chamber 81, the servo valve
`71 being in its normal position, is con(cid:173)
`nected to atmosphere via the output line
`89 of the latter and the compression spring
`8.:.:. consequently holds the valve plate 88 in 75
`abutment with the air outlet pipe 87. When
`the servo valve 75 is switched on by the
`control system 60 and then connects the
`first valve chamber 81 to the inlet man(cid:173)
`ifold via the pipe line 85, the negative pres- 80
`sure takes effect and lifts the diaphragm
`83 so far from the air outlet pipe 87 that
`auxiliary air is able to pass from the line
`58 via the air outlet pipe 87 to a point
`downstream of the closed throttle valve 48. 85
`In the spark timing device as shown in
`Fig. 10, in order to rotate the mounting
`plate 54, shown in Fig. 1, for the contact
`breaker 55,
`the spark timing adjusting
`element 77 is arranged in tandem with a 90
`second negative pressure element 91,
`providing a basic setting which is con(cid:173)
`nectible to the inlet manifold by means of
`a control line 92 via an idling bore, which
`is not shown in detail. The spark timing 95
`adjusting element 77
`is connected, as
`shown in Fig. 8, via a suction pipe 94,
`together with the pipe 85 from the pressure
`element 76 to the connection 86 of the
`servo valve 75. When the servo valve 75 is 100
`switched on by the control system 60, the
`in
`the spark
`timing
`negative pressure
`adjusting element 77 moves an actuating
`rod 95, connected to the mounting plate
`54. in the direction of the arrow and 105
`thereby rotates the mounting plate 52 so
`far that the firing instant is moved 15° to
`20 o in the spark retard direction from its
`basic setting, namely, approximately 5o
`A.T.D.C. The ignition processes are then 110
`triggered at a crankshaft angle of 20 o to
`25 o A.T.D.C. This causes the braking ac-
`tion of the internal combustion engine to
`be fully maintained on overrun, although,
`owing to the auxiliary air supplied while 115
`the throttle valve 48 is closed and to the
`resultant extra amount of fuel injected, the
`combustion processes in the cylinders of
`the internal combustion engine are main-
`tained.
`WHAT WE CLAIM IS:-
`1. An internal combustion engine hav-
`ing an electrically controlled, petrol in(cid:173)
`jection system comprising at least one in(cid:173)
`jection valve which is arranged
`to be 125
`opened in synchronism with the rotation of
`the crankshaft and, by means of an elec(cid:173)
`trical control system to be maintained open
`for a period dependent upon the pressure
`of the intake air downstream of a-throttle 130
`
`120
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`1447 791
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`valve of the engine or upon the flow of the
`intake air of the internal combustion en(cid:173)
`gine, a device for acting upon the internal
`combustion engine during overrun, which
`5 device comprises a control valve
`for
`auxiliary air arranged in a circuit by-pass(cid:173)
`ing the engine throttle valve, and a spark
`timing device which is actuable together
`with
`the control valve and which
`is
`10 arranged to retard the ignition from its
`lOa
`to 20a so that it
`basic setting by
`occurs between 15° to 25° A.T.D.C.
`2. An internal combustion engine as
`claimed in claim 1 in which the spark tim(cid:173)
`IS ing device is arranged to retard the ignition
`from its basic setting by 15 o to 20 o.
`3. An internal combustion engine as
`claimed in claim 1 or 2, in which an en(cid:173)
`gine speed transducer and a throttle valve
`20 transducer are provided for the device in
`order to identify overrun operation.
`4. An internal combustion engine as
`claimed in claim 3, in which the engine
`speed transducer includes a switch which is
`25 adjusted so that, on a fall in the speed of
`the internal combustion engine, the switch(cid:173)
`ing state of the switch changes when the
`speed falls below a predetermined mini(cid:173)
`mum value greater than the idling speed.
`5. An internal combustion engine 'as
`claimed in claim 3, in which the throttle
`valve transducer comprises a switch which
`is actuable by means of a shaft of the
`throttle valve and which changes
`its
`35 switching state when the throttle valve re(cid:173)
`turns to its closed position.
`6. An
`internal combustion engine as
`claimed in claim 3, in which, instead of an
`engine speed transducer or in addition to
`40 an engine speed transducer, a gear position
`transducer is provided, which provides a
`signal dependent upon the gear engaged in
`a gearbox.
`7. An internal combustion engine as
`45 claimed in claim 6, in which a clutch posi(cid:173)
`tion transducer is provided which delivers
`a control signal to the device when the
`clutch is operated.
`8. An internal combustion engine as
`50 claimed in any of claims 1 to 7, having in
`its
`inlet manifold a diaphragm plate,
`pivotable against a restoring force and ac(cid:173)
`ting as an air intake flow meter, a switch,
`whose switching state changes at a pre-
`5.5 determined pivot angle of the diaphragm
`plate, being connected to the shaft or the
`diaphragm plate to deliver a control signal
`to the device.
`9. An internal combustion engine as
`60 claimed in any of claims 1 to 8, in which a
`vehicle speed transducer is provided to de(cid:173)
`tect the overrun state whose switching state
`changes when the speed of a vehicle driven
`by
`the internal combustion engine falls
`65 below a predetermined value.
`
`10. An internal combustion engine as
`claimed in any of claims 1 to 9, in which
`the exhaust system of the engine includes a
`thermal and I or catalytic reactor and in
`which a temperature sensor, provided in 70
`the exhaust system of the internal com·
`bustion engine, operates in parallel with
`the engine speed transducer and at low ex(cid:173)
`haust gas temperatures retards the spark
`timing device and opens the auxiliary air 75
`valve during slow idling.
`11. An internal combustion engine as
`claimed in any of claims 1 to 10, in which
`an electromagnet is provided for actuatin.f!
`the spark timing control, or the auxiliary 80
`air valve or both.
`12. An internal combustion engine as
`claimed in any of claims 1 to 10, in which
`an electromagnetically actuable servo valve
`is connected to the inlet manifold of the 85
`internal combustion engine downstream of
`the throttle valve in the air intake direc(cid:173)
`tion, the servo valve connecting, in its open
`position, at least one vacuum controlled
`element to the partial vacuum in the inlet 90
`manifold.
`13. An internal combustion en!!:ine a.'>
`claimed in claim 12, in which the pre\,..sure
`element is the auxiliary air control valve
`which has two valve chambers in its hous- 95
`ing and a diaphragm separating the two
`valve chambers, the diaphragm being acted
`upon by the pressure of a spring accom(cid:173)
`modated in one of said valve chambers
`connectibl~ by the servo valve to the inlet 100
`manifold
`and urging
`a valve plate,
`arr~nged at the centre of the diaphragm,
`agamst the end face of an auxiliary air
`outlet pipe communicating with· the other
`to which an 105
`of said valve chambers
`auxiliary air inlet pipe is connected.
`·
`14. An internal combustion engine as
`claimed in claim 13 in which said outlet
`pipe is located centrally of the other of
`said valve chambers.
`15. An internal combustion engine as
`claimed in claim 12, 13 or 14, in which a
`second vacuum controlled element, whose
`control line is connected to the inlet man(cid:173)
`ifold by way of an idling bore, is arranged 115
`in tandem with the first vacuum controlled
`element, wliich is connectible by way of
`the servo valve to the inlet manifold.
`~6. A.n int~rnal ~ombu~tion engine as
`clatme?.m clatm 15 u~ which an actuating 120
`rod, wruch acts eccentncally on a mounting
`plate rotatable about the axis of the con-
`tact breaker cam for the ignition contact
`breaker, is connected to said first vacuum
`controlled element.
`17. An internal combustion engine sub(cid:173)
`stantially as illustrated in Fig. 1 having an
`overrun device constructed and adapted to
`as
`hereinbefore
`operate
`substantially
`particularly described with reference to and 130
`
`110
`
`125
`
`Page 5 of 10
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`

`

`6
`
`1447 791
`
`6
`
`as illustrated in Fig. 2; or Fig. 3; or Fig. 4;
`or Fig. 5; or Fig. 6; or Fig. 7; and having
`a servo valve constructed substantially as
`illustrated in Fig. 8; or Fig. 9; or Fig. 10
`5 of the accompanying drawings.
`
`W. P. THOMPSON & CO.,
`Coopers Buildings,
`12 Church Street,
`Liverpool. Ll 3AB.
`Chartered Patent Agents.
`
`Printed for Her Majesty's Stationery Office by The Tweeddale Press Ltd., Berwick·upon·Tweed, 1976.
`Published at the Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copie~
`may be obtained.
`
`Page 6 of 10
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`

`

`I 447 791
`4 SHEETS
`
`COMPLETE SPECIFICATION
`This drawing is a reproduction of
`the Original on a reduced scale.
`SHEET I
`
`Fig.1
`
`57
`
`I
`
`53~ I I
`I
`
`Page 7 of 10
`
`

`

`I 44":7 791
`4 SHEETS
`
`COMPLETE SPECIFICATION
`This drawing is a reproduction of
`the Original on a reduced scale.
`SHEET 2
`
`I•
`
`I•
`
`60
`
`67
`
`oo
`
`oo
`
`t=ig.2
`
`63
`
`64
`
`J:ig.J
`65
`
`66
`
`64
`
`Fig.4
`67
`
`64
`
`Fig.s
`
`68
`
`60
`
`Page 8 of 10
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`

`

`I 447 791
`4 SHEETS
`
`COMPLETE SPECIFICATION
`This drawing Is a reproduction of
`the Original on a reduced scale.
`SHEET 3
`
`F/g.6
`69
`
`64
`
`Fig.7
`63
`
`64
`
`r--,
`............
`77-r
`'-- _.J
`
`70
`
`6'0
`
`60
`
`J:ig.8
`
`60
`
`Page 9 of 10
`
`

`

`I 447 791
`4 SHEETS
`
`COMPLETE "SPECIFICATION
`This drawing is a reproduction of
`the Original on a reduced scale.
`SHE.E.T 4
`
`Fig.9
`
`83
`
`t
`
`Page 10 of 10
`
`