US2874640A - Pump - Google Patents

Description

1959 H. H. VICKERS I 2,874,640

PUMP

Filed March 11, 1954 2 Sheets-Sheet 1 FIG.'I

Herbert H. Vickers Inventors By Attorney H. H. VICKERS PUMP Feb. 24, 1959 2 Sheets-Sheet 2 Filed March 11, 1954 I r r Alf! FIG. 2

Inventor Herbert H. Vickers Attorney United States Patent PUMP Application March 11,1954, Serial No. 415,563

3 Claims. 01. 103-31 This invention relates to pumping apparatus and more particularly relates to apparatus adapted to charge fuel to an internal combustion engine. Still more particularly this invention relates toapparatus adapted to separately charge predetermined amounts of fuel to individual cylinders of 'a multiple-cylinder internal combustion engine. a

It is well known that the distribution of fuel to individual cylinders of a multiple-cylinder internal combustion engine has a substantial effect on the operation of such an engine, especially in regard to engine power and fuel economy. In the case of a multiple-cylinder internal combustion engine which employs a carburetor and an intake manifold which are common to all cylinders, it is not unusual to have a wide variation in the amounts of fuel distributed to the difierent cylinders. Thus some of the cylinders will operate. on the lean side and others on therich side of that required for maximum power or maximum. fuel economy, as thecase may be. For a particular engine, improvement of fueldistribution is one of the principalways in which power can be gained. Normally, however, for a particular engine the advantage to be gained directly as a reduction in fuel consumption due to the better distribution is small. However, the resultant improved performance of the engine that is gained due to'the better fuel distribution Will permit readjustmentof the air-fuel mixture by reducing the amount of fuel required so as to afford increased economy in this manner. There are also a number of other advantages to be gained from improved fuel distribution, such as easier engine starting, especially under conditions.ojf.extremely low temperature,.elimination of carburetor icing,

better accelerationcharacteristics under heavy load cone. dit'ions, and elimination of 'vapor look when operating under conditions of exteme heat. I Although, of couse, the engine performance depends upon the particular mixture of air and fuel reaching the 7 cylinders, the distribution problem is mainly attributable.

to the fuel portion of the mixture due to the peculiar volatility properties of a liquid fuel. More specifically, when employing a conventional carburetor the fuel may reach the cylinder -as a. combination of avaporized fraction, an atomized fraction, anda liquid heavy endsfr'action, sothat under these. conditions optimum distribution ofthe fuel is extremely difiicult to obtain. Manufacturers of fuels are constantly striving to; improve the volatility characteristics'of their fuels in order to improve this distribution offuel to the various cylinders of an engine, However,'there is a limit as to the improvement which can be gained in this manner, asliquid fuels, such as gasolines, are a mixture of hydrocarbons'having different volatility characteristics so that perfect distribution with conventional carburetion devices is therefore inherently limited. l e

In regard to the air-fuel mixture, it is, of course, essential that combustible proportions be employed, If this is the case, then'the rate at which the flame is propagated throughout the combustible mixture in 'the' cylinder, "and consequently the time required inan engine to develop maximum pressure, is dependent in avery large measure on theproportions of air and fuel being used. If the mixture is either too lean or too rich, the rate of combustionwill be decreased and consequently the power of the engine will be reduced. For any given cylinder there is an optimum ratio of air tofuel required to develop maximum power atany given speed and load. The limits of flammability for mixtures of air and normal gasoliues are approximately 7:1 by weight at the low or rich end of the mixture scale and about 20:1 at the high or lean end. Complete combustion of the air-fuel mixture for commercialgasolines occurs at approximately 15: 1. For conventionalautomotive engines maximum engine horse power is developed at a mixture strength of about 12.5:1

and maximum fuel economy usually is obtained at, or

slightly above, the 15:1 ratio required for complete combustion. It is readily apparent, then, that the full power and maximum economy requirements differ. This is in large measure overcome in automotive engines by suitable carburetion devices that furnish a fairly rich mixture to provide maximum power for acceleration and a' reasonably lean mixture to provide good fuel economy at substantially constant speed; Howeve'r,even at substantially constant speed there is a compromise made between power and fuel economy so that the air-fuel ratio is usually set someplace between 12.5:1 and 15:1. Normally when operating at substantially constant speed and load conditions, fora rather small sacrifice in maximum power, the air-fuel ratio may be increased considerably to give an appreciable increase in the, economy of Thus it will be seen that the power and.

A number of different steps have been taken to im- 1 prove the distribution, of fuel to individual cylindersof fill an internal combustion engine, For example, as previously mentioned, the volatility of the fuel itself has been improved. Also heating devicesh'ave been installed in conjunction with the intake manifolds to imp rove the vaporization of the fuel, However, one of themost significant steps'taken to improve fuel distribution has been" the development of separate fuel injectiondevices for each individual cylinder. Such fuel distribution devices have to date been employed extensively in theaircr'aft engine an'd'the diesel engine fields.

combustion engine. Briefly, the present invention cornprises an individualiinjection device foreachindividual cylinder of an internal combustion'engine. Each injection device of this invention includes a Bourdon tube which is provided with a pressureiresponsiveinlet means for receiving a liquid fuel from a' fuel source common! to all of the feed means and a pressure responsive outletmeans for,.discharging a predetermined amount of liquid-,- fuel therefrom to the cylinder. associated withit. ln combination with theBourdontube is a variable control device for adjusting'the amount. of run dischargedIfrom the Bo'urdon tube." ran-mama controlf ..devieef includes achamber which is divided into two fluid tight compart However, hereto- ,mentsbya flilid tightfiexible' diaphragm with one of One end of' theiBourdon tube:- is'ma-intained ina fixed position while the otherendis" connected to operating means associated 'Withits particular cylinder. Theopen atingmeans flexes the Bourdon tube inone direction so as? to therebyincreasetheeffectivevolume 'of the Bourd'on' tube inordertolpermit fuel'to be taken into the interior of the Bourdon tubeqthrough the inlet means. At the appropriate time du'ringthe cycle of the associated'cylinderthe operating means; flexes the Bourdon tube in the other direction so as to thereby decrease the effective volume of the Bourdon tube in order to discharge fuel therefi'om into the. cylinder associated therewith; 'Duringth'e discharge movemenLo'f'the Bourdon tube the flexible diaphragm of the variable control device is alsofiexed due to the pressure created by the fiexure of the Bourdon tube. This displacementof, the diaphragm, therefore, in effect increases the effective volume of the Bourdon" tube and the. limit of this ex:

pansion of the diaphragm is controlledby the position,

of the piston member. Thus the greater the movement of the diaphragm, the less fuel' is pumped to the cylinder. The position of the piston member is. controlled by the accelerator of the engine. whiehiscommon toall injection,

devices. Provisionis made for. minor changes in. the position of the piston member. tov permit. manual adjustment of each injection device- In the. above described manner a predetermined. anddefinite amount of. liquid fuel may be discharged separately into. each cylinder. of amultiple cylinder. internal; combustion engine.

It is an object of. this invention to provide apparatus for improving the performance andfeconomy of operation of internal. combustion engines.

It is a further object of. this. invention. toprovide asimple, inexpensive, and dependable apparatus for separately charging a predetermined and definite amount of fuel to each cylinder of a multiple cylinder internal combustion engine.

These and other objects of: this invention will be apparent from a reading of this specification, which will best be understood when read. in conjunction with the. drawings, in which: a

Fig. 1 is a diagrammatic showing of a four cylinder drawing of engine 14 shown in- Fig.1 is-purely schema-tiev and shows only those parts. of enginev 14. which. are necessary for an understanding of this invention. The parts not shown are conventional to internalpcornbustion engines,.and their operation and arrangement will. be readily understoodby thoseskilled in. the art. Cylinders, 10, 11,

able therein. Thus'pistons 15, 16, 17' and 18arearranged respectively within cylinders 10, 11, Hand 13.. Each 12, and 13. are each provided with a piston axially movpiston is preferably provided with piston rings. Connecting rods '19,- 20, 21, and 22 are respectively connected to pistons 15, 16, 17 and 18 at their lower ends andare respectively eonnected to cranks 23, 24, 25 and 26 of crankshaft 27 -at'their othere n'ds. Crankshaft '27 is supported by bearings28and 29 which arearranged'at the two ends of'crahkshaft17 such t hat crankshaft ll islf axially rotatable therein.

Engine 14 delivers two power strokes for each revolution-of-crankshaft- 27: Thus-in Fig. 1- cylinderlfl is about to begin the power-or working stroke, cylinder 11 is about to begin the exhaust stroke, cylinder 12 is about to begin the suction or intake stroke, and cylinder 13 is about to begin the compression stroke. Each of the cylinders will fire 0ne;-f'0r every two revolutions of crankshaft 27 with the order of firing being cylinders 10, 11, 12 and 13. However, it is to be understood that the present invention is, not limited; to this particular arrangement or number. of cylinders. On the power stroke the ignited combustible mixture of air and fuel expands to move the pistondownwards inFig. 1; on the exhaust'stroke the piston moves upward in Fig. 1 to discharge the exhaust: gases from thecylinder which were formed by the combustion occurring in the power stroke; on the intake or suction stroke the piston moves downward again to draw in a combustible air-fuel mixture;

and on the compression stroke the combustible air-fuel Arranged on one end of crankshaft 27 is gear 30,

which is rotated by crankshaft 27. Meshing with gear- 30 is gear 31 which is provided in this system to mesh with, gears 30 and 34 to drive gear 34. in the samedirection as gear 30. It will be noted that gear 31 rotates at the same speed as gear 30 and crankshaft 27. Gear 31 is arranged 'on shaft 35,, which is Supp rted in bearings 32 and 33. Gear 34 is designed, to rotate at one-half of the speed of gears 30 and 31 and crankshaft 27. and 'it is arranged on one end, of camshaft 36, which is sup ported at its ends by bearings 37 and 38.Wh er'ein it is adapted to rotate. Arranged alongcamshaft 36 inspaced relation to each other are cams39, 40, 41, and 42. These cams are arranged consecutively ninety degrees apart from each other in respect to their angular positions;

Cooperating with cams 39, 40, 41, and 42 are their respective cam followers, 43, 44, 45,. and 46, which are attached to the ends of push rods, 47, 48, 49, and respectively. The respective push rods extend at their other ends into fuel injection devices 51, 52, 53, and 54. These push rods are the operating means by which the. fuel, injection devices. of this invention are actuated so that a separate predetermined amount of fuel will be discharged into eaeh'of cylinders 10, 11, 12, and 13. The rotation of camshaft 36 causes the cams thereon to rotate so that a reciprocating motion is imparted to the push rods due to the cooperation of the cams and cam followers- Thefseparate amounts of fuel discharged from feed. injection devices 51, 52, 53, and 54 are respectively conducted to cylinders 10, 11, 12, and 13 by means. of conduits. 55, 56, 57and 58. Arranged at the end of each conduit at the fuel inlet to each cylinder is .a spring loaded injector nozzle which is designed to open at a given predetermined pressure to permit fuel to flow through the conduits. The nozzle in the open position sprays a definite amount of fuel into the cylinder and immediately thereafter closes to effect a seal against any pressure existing in the cylinders. In effect the spring loaded injector nozzles function as flow check means, holding against pressure in an upstream direction through the conduits 55, 56, 57 and 58. Thus spring loaded injector nozzles 59, 60, 61, and 62 are arranged respectively in conduits 56, 57, and 58 immediately prior to their respective cylinders. Any suitable'conventional pressure responsive nozzle which will perform the functioncontemplated may be employed. A typical spring loaded injector nozzle of the. character contemplated is'one such as illustrated in the'publication Diesel shown in detail.

Engines" by B. J. Van Bongart, D. Van Nostrand Company, Inc., New York, 1938, by Fig. 92 onpage 109 thereof.

Liquid fuel is fed to fuel injectiondevices 51, 52, 53, and 54 through inlet conduits 63, 64, 65, and 66 respectively, which all communicate with common conduit 67, which in turn communicates with the source of fuel such as fuel tank 74. A fuel pump 75 may be installed in conduit 67, if necessary, to provide any pressure which may be required to assure passage of fuel from fuel tank 74 to the fuel injection devices of this invention. Mechanicallyconnected to fuel injection devices 51, 52, 53, and 54 are push'rods 68, 69, 70, and 71 respectively, which are connected attheir other ends to bar 72. Connecting rod 73, which is connected to bar 72, is adapted to be actuated by the accelerator (not shown) of engine 14. Operation of the accelerator depresses or raises push rods 68, 69,70, and 71 to thereby regulate the amount of fuel injected into engine .14 as will be hereinafter described in greater detail.

\ Referring nowto-Fig. 2. fuel injection device 52 is It is to be understood that fuel injection devices 51, 53 and-54 areidentical in design to fuel injection device '52. Reference character 80 designates a mounting block which may be the cylinder head of engine 14 upon'which the other parts of fuel injection device 52 are mounted. Supported upon mounting block 80 is housing 81, which is secured to mounting block 80 by bolts 78 and which encloses some of the working parts of fuel injection device 52. Push rod 48 extends up into housing 81 through opening76 in mounting block 80, and it is longitudinallymovable therein. The end of push rod 48 within housing 81 is adapted to cooperate with ball 85 of bolt 82, which is threaded into arm 83 of rocker arm 84 and locked in place by means of nut 79. Ball 85 of bolt 82 is adaped to engage socket 86 arranged at the end of push rod 48.

Rocker arm 84 is pivotally mounted on pivot 87 arranged on the upper end of support 88 which in turn is secured at its lower end to mounting block'80. Arm 89 of rocker arm 84 is adapted to cooperate with one end of valve stem 90, which is guided by'slot 91 in mounting block 80. In this specific embodiment of the present invention the lower end of valve stem 90 is connected to the air inlet valve (not shown) associated with cylinder 11 so that the pivotal movement of rocker arm 84- will operate the air inlet valve through valve stem 90 so that the air inlet valve will be opened and closed at the appropriate times in the cycle of cylinder 11. In moving downwardvalve stem 90 opens the air inlet valve. Valve stem 90 is provided at its upper end with an an nular flanged member 92 which is rigidly secured thereto and which engages spring 93 which is disposed between annular flanged member 92 and mounting block 80. Thus when connecting rod 48 is raised, rocker arm 84 is turned in a counterclockwise direction so that arm 89 depresses valve stem 90, which compresses spring 93;

and when connecting rod .48 ,islowered, rocker arm 84 is turned in a clockwise direction due to the force, exerted;

on arm 89 by spring 93 acting through valve stem 90.

Arm 94 of rocker arm 84 is integral therewith and I extends upward from pivot 87 substantially perpendicular.

to arms 83 and 89. Arm 94 is provided in its upper end with slot 94 which cooperates with pivot 96 of arm 95 to provide a pivotal connection'between the lower end of arm 95 and the upper end of arm 94. .Pivot 96 is positioned at the lower end of arm 95, is integral'there-.

at their point ofjuncture. The upperend' of arm 95is' connected to pivot 97, Wh ChiIiS supported byirneans of fixed arm98 to mounting block. 99, which in turn issecured to housing 81 by means of'one or n'iore'bolts 77.

Mounting block 99 is thus rigidly fixed to mounting block by means of housing 81.

Pivot 97 is mounted on arm 98 at a position substantially coinciding with the center of the arc of 'an arcuate tube 100. End 101 of tube 100 is secured to the end of arm 95 which is adjacent to pivot 96 by any conventional means such as by welding. Tube 100 is a slender, thin-walled tubewith its one end 101 being closed and its other end 102 being open. -Tube 100 is ofthe type, used in Bourdon pressure gauges but is not restricted thereto. It will be hereinafter termed Bourdon tube 100 to imply that there is a definite relationship between the shape of the tube and the volume and pressure of fluid contained therein. Bourdon tube 100 is preferably formed in an arc of at least about and preferably has a generally elliptical shape in transverse cross section. If desired, Bourdon tube 100 may be coiled in an arc ex ceeding 360. Bourdon tube 100 is constructed of a-material such as stainless steel, carbon steel or Monel metal which is capable of withstanding a maximum bursting pressure of at least about 2000 p. s. i. End-102 of Bourdon tube 100 is rigidly fixed to block 99. Thus any longitudinal movement of push rod 48 turns rocker arm 84 so that arm' 94 causes arm to pivot, which in turn causes a movement of end 101 of Bourdon tube 100.

The resultant flexure of Bourdon tube causes a change in shape thereof which results in a change inthe volume or capacity of the interior of Bourdon tube 100; Thus when a fluid is sealed in the interior of Bourdon tube 100, any flexure of the tube will result in a change in pressure on the particular fluid.

In the particular arrangement shown in Fig. 2 when end 101 of Bourdon tube'100 is moved slightly to the left in the drawing, the volume of Bourdon tube 100 is decreased, which causes an increase in pressure of any fluid contained therein. Because Bourdon tube 100 'is generally'elliptical in transverse cross section, the movement of end 101 of Bourdon tube 100 to the left in Fig. 2 will increase the major axis of this ellipse and will decrease the minor axis so that the resultant trans-. verse cross sectional area of Bourdon tube 100 is decreased. It is to be understood that the lengthof Bourdon tube 100 remains substantially constant at all times. On the other hand, when end 101 of Bourdon tube 100 is moved slightly to the right in the drawing, the volume of Bourdon tube 100 isincreased, which causes a de-.

crease in pressure of any fluid contained therein. Thus the movement of end 101 of Bourdon tube 100 to the right in Fig. 2 decreases the major axis of the ellipse and increases the minor axis so that the resultant transverse cross sectional'area of Bourdon tube 100 is increased;

position, end 101 of Bourdon tube 100 is moved to the,

left in Fig. 2 so that the volume of Bourdon tube 100 is at its smallest value in this particular arrangement. On the other hand, when push rod 48 moves downward to its lowest position, end 101 of Bourdon tube 100 is moved to the right in Fig. 2 so that the volume of Bourdon tube 100 is at its largest in this, particular arrangement. The particular position of push rod 48 at any one moment will bedependent, of course, upon the position of cam 40 on camshaft 36. Push rod 48 and Bourdon tube 100 are shown at their intermediate positions in Fig. 2. When in this intermediate position, Bourdon tube 100 is preferably in its preformed natural and unstressed Communicating with end 102 of Bourdon tube 100 is one end of fuel inlet passageway 110, which is bored from block 99. The other end of fuel inlet passageway communicates with chamber 111, which is bored out of,

block 99 and whichvin turn communicates, at its other end with enlarged chamber 112. Plug '113, which is par-Q tially threaded, is arranged in chamber 112' engaging 7 the-men l hread etblc ls 9 h c -Part l defin chamber In its int rmediat Por ion p u 13 s ecked awns? hat n hi portion plu .1 is s a fr m he w ll fo m n c amber 11 ad 11. of P s 1315 main in d i a flui igh r a o sh p it block 99 by means of annular gasket 115, which is disposed therehetween. Communicating With chamber 112 at a rointt sins t ke dQ n p r i n o Pl s 113 is nl 16 of c nd 6 thrc hi h li u d fuel enters f l injection device 52. Inlet 116 is indicated by the dotted circle shown in chamber 112 in Fig. 2. Plug 113 is provicled in its necked down intermediate portion with a horizontal bored opening 117 which communicates with the interior of chamber 112. Plug 113 is also provided at its end, adjacent to chamber 111 with a vertical bored opening 118 which communicates at one end with opening 117 and at the other end with chamber 111. Opening 118 in plug 113 formsseat 119, which is circular in form. Cooperating with seat 119, is ball 120, which is generally maintained in fluid tight contact with seat 119 by means of spring 121 arranged in chamber 111. Seat 119, ball 1% and spring 121 a1'e designed to provide a check valve arrangement for fuel inlet passageway 110. The strength of spring 121 is selected to be substantially less than the force exerted on ball 120 by the fuel in opening 118 so that ball 120 will be displaced from seat 119 when the pressure of the fuel in the interior of Bourdon tube 100 is slightly less than the pressure of thefuel in opening 118. Gasket 122 is arranged around seat 119 between block 99 and the end of plug 113 adjacent seat 119 to prevent the passage of fuel from chamber 112 to chamber 111 other than through opening 118.

The manner in which fuel is drawn in Bourdon tube 100 on the intake or suction strokes is as follows. When push rod 48 is moved downwards, rocker arm 84 is turned such that arm 94 is turned to the right in Fig. 2. The movement of arm 94 causes arm 95 to also move to the right and in so doing causes end 101 of Bourdon tube 100to move to the right also. This movement or flexure of Bourdon tube 100 enlarges the volume of Bourdon tube 100 as previously described, which causes a decrease in pressure of the fuel therein. When the pressure of the fuel in Bourdon tube 100 becomes slightly less than the pressure of the fuel in conduit 64, which occurs almost immediately after the suction stroke in the Bourdon tube is begun, fuel will flow from conduit 64 through inlet 116 into chamber 112' around the necked down portion of plug 113 and then through openings 117 and 118 of plug 113 into chamber 111 by forcing ball 120 away from seat 119. The fuel then passes through chamber 111 through fuel inlet passageway 110 into the interior of Bourdon tube 100. Chambers 111 and 112, openings 117 and 118, and passageway 110 are in effect a continuation of inlet conduit 64. In this manner fuel is drawn into Bourdon tube 100. This in effect their is the intake stroke of the pumping apparatus of this invention. On the other hand, when the pressure in Bourdon tube 100 exceeds the pressure in conduit 64, such as occurs when push rod 48 is moving upward so that Bourdon tube 100 is flexed in the opposite directior ball120 is forced by spring 121 back against seat 11 9 to thereby prevent passage of fuel from Bourdon tube 100 back into conduit 64. In the continuous optat n at he a p us f thi in en o al of e fo en ioned, ham s and p a e y will. e l ed w h fuel at all times. Of course, it is to be understood that he fie eu ial Pres ure b en he te ior o ou tube 100 and conduit 64 must be sufficient to overcome the slight force exerted on ball 120 by spring 121 efore fu Will flo n Bourdon e Also communicating with end 102 of Bourdon tube 100 in?! ischar e passa wa 123, w ch s bc out Of block B u don tube u inlet pa sage y 0 ist' u disc r a ew 113 f m a so a Y- shaped opening in block 99. Fuel discharge passageay 231 en ar e a t disc ge oup 1 is arranged in thisenlarged end of fuel discharge passageway 123 and the threads of coupling 124 engage the internal threading of block 99, which partially defines the enlarged end of passageway 123, to thereby secure coupling 124 thereto. Coupling 124 is provided with nut 125 which is turned down against annular gasket 126 to provide a fluid tight external seal between coupling 124 and block 99. Communicating with fuel discharge passageway 123 through coupling 124 is conduit 56, which is secured to coupling 124 by fastening means 127. Fuel is thus discharged from Bourdon tube 100' through fuel discharge passageway 123 and coupling 124, which are in effect an extension of conduit 56. The fuel then passes through conduit 56 to cylinder 11 through spring loaded injection nozzle 60. In this specific embodiment of the present invention the fuel is discharged into cylinder 11 during the suction stroke together with an appropriate amount of air which is introduced through the air inlet valve operated by valve stem 90. However, it is to be understood that, if desired, the time of injection could be changed so that the fuel would be injected at the end of the compression stroke and during the power stroke. This change would merely involve a change in timing of the particular elements involved and will be apparent to those skilled in the art. As previously mentioned, spring loaded injection nozzle 60 is arranged at the end of conduit 56 to regulate the flow of fuel into cylinder 11 as well as to spray the fuel into cylinder 11. Spring loaded injection nozzle 60 is designed to open in response to a predetermined pressure developed in Bourdon tube 100 when the tube is flexed for discharge. Normally a setting responsive to a pressure of about 100 p. s. i. in conduit 56 will be suflicient when the fuel is discharged during the suction stroke of cylinder 11. If it should be desired to discharge fuel into cylinder 11 at the end of the compression stroke and during the power stroke then a setting responsive to about 1000 p. s. i. will be required due to the pressure existing in cylinder 11 at that part of the cycle. After discharge of the fuel charge into cylinder 11, spring loaded injection nozzle 60 is closed by the force of its spring so that no material can move backwards from cylinder 11 into the interior of Bourdon tube 100. The function and operation of nozzle 60 is similar to an injection nozzle employed in Diesel engines and will be apparent to a person skilled in the art.

Communicating with fuel discharge passageway 123 is chamber 130, which comprises passageway 131 and compartment 132 which are cored out of block 99. Compartment 132 is an enlarged opening in block 99, and plug 133, which is threaded, is arranged therein and is secured to internal threading of block 99, which partially defines compartment 132. Arranged between the lower end of plug 133 and the annular wall of block 99 defining the adjacent side of compartment 132 is diaphragm 134. Plug 133 is turned down into compartment 132 so that diaphragm 134 is held securely in place by the resultant compressive force. Diaphragm 134 is made of a flexible material which is capable of withstanding many flexures without losing its elastic properties such as an oil-resistant rubber or metal such as brass, steel or Monel. In effect then, only passageway 131 of chamber communicates in fluid relationship with fuel discharge passageway 1 23, as diaphragm 134 provides a fluid tight seal between passageway 123, and compartment 132.

Plug 133 is provided with an axially arranged, preferably cylindrical, opening 139 which extends the entire length thereof. Cooperating with opening 139 is plunger 129, which comprises head 136 and piston 13,8. Arn ed Wit n Qu ui 1.39 i p on 3 which s l y movable therein. Plug 133 is provided at its outer end with an annular recess'135, which is larger in diameter than opening139 spring 1 37. is arranged around piston 138 of plunger 129 an is partially-compressed between 9 recess 135 of plug 133 and head 136 of'plunger129; The bottom of piston 138 of plunger 129is normally spaced from diaphragm 134 so that expansion chamber 132' is formed therebetween. Expansion chamberi132' is provided in this invention to permit expansion of diaphragm 134 in response to pressure exertedthereon .by the liquid fuel is passageway 131. .The degree of expansion of diaphragm 134 is thus. governed bythe position of piston 138 of plunger 129, and as a result, therefore, determines the amount of fuel which 'is discharged from Bourdon tube 100 into cylinder 11. While passageway 131 is shown in Fig. 2 as communicating directly with fuel discharge passageway 123, it iszto be understood that "this particular arrangement is not essential, as it is. only essential that passageway 131 be in fluid communication with the interior of Bourdon tube 100.

Head 136 ,of plunger 129 is provided with a threaded opening 128 with the threads engaging bolt 140. Cam 141, which has an eccentric bearing surface 146,"is adapted to cooperate with the head of bolt 140" so that as arm 141 is turned about pivot 142, plunger 129 is raised or depressed in opening 139 in plug 133 to thereby vary the size of expansion chamber 132. Arm-141 is rigidly fixed to arm 143, which is actuated by push rod 69 associated with the accelerator of engine 14. Thus, when push rod 69 is depressed, arm 141 is rotated in a'counterclockwise direction in Fig; 2' so that the smaller radius portion of arm 141 is brought into contact with bolt 140. Spring 137 then forces plunger129 out of opening 139 in plug 133 so thatexpansion chamber 132 isthereby enlarged. Expansion chamber 132' is providedwith vent line 145 so as to permit free movement of diaphragm 134 and plunger 129; w

During the discharge stroke'of Bourdontube 100 diaphragm 134 is expanded outwards .due to the pressure buildup in Bourdon tube 100 and passageway 131 un'tilit contacts the bottom of piston 138 of plunger 129; The particular position of piston 138 will govern 'how much diaphragm 134 is expanded. By regulating the displacement of diaphragm 134 in this manner it 'is possible to thereby vary-the amount of fuel pumped from Bourdon tube 100 to cylinder 11; Without the variable. control device comprising piston 138, diaphragm 134, and charm ber 1 32', Bourdon tube 100 would pump the same amount of fuel on each discharge stroke. In general, the

position'of piston. 138 will be regulated by the accelerat ing mechanism of-the engine through push rod} 69, al-

though provision is made for a minor manual adjustment by means of bolt 140 which may be turned to thereby ad uSt the position of piston 138 by varying the combined length of bolt140'and plunger 129.

.In the operationof this invention, during the intake stroke of Bourdon tube 100, diaphragm 134 remains in discharge stroke. Thereafter, at thecommence'mentof the intake stroke, the pressure in Bourdon tube 100 is decreased to the'point where spring loaded nozzle closes. Also at the commencement of the intake stroke of Bourdon tube 100, diaphragm 134, due to its elastic properties, returns to its normal fiat position. Passageway 131 is kept small so that thediaphragm 134 will not be drawn into it, but if the strength of diaphragm 134 is insufiicient, a metal screen (not shown) may be arranged under it so that on the intake stroke, diaphragm 134 will not be withdrawn from its flat position into passageway 131. How ever, it is to be understood that even should diaphragm 134 be drawn back partially into passageway 131, the apparatus of the present invention would still be workable. However, it is essential that this amount of withdrawal be constant, so it is therefore preferable to employ such a metal screen. The edge 139' of opening 139 is rounded to permit easier expansion .of the diaphragm into the chamber 132';

Inthe above-described manner diaphragm 134 and its associated elements provide the necessary variable control deviceessential to 'the successful application of Bourdon tube 100 to 'automotiveengines. By adjusting the position of piston 138 it is possible to regulate the amount of fuel pumped from substantially zero to an amount equivalent to the maximum pumping capacity of the Bourdon tube 100. It is, of course, necessary to select a Bourdon tube of such a capacity that it will pump at least the maximum amount of fuel required by cylinder 11. Also it is necessaryto provide a maximum capacity for expansion chamber-132 which is substantially equal to the the flat position shown in Fig. 2. At the end of the-intake stroke the Bourdon tube, together with the passageways communicatingwith it, arefilled with fuel and diaphragm 134 is still in,the fiat positiom: The intake stroke of Bourdon tube 100 extends from the time that end 101 is at the extreme left in Fig. 2 until end 101 has moved to the extreme right in the drawing. Thereafter the Bourdon tube 109 beginsits discharge stroke by moving from right to left in Fig. 2. Immediately after the discharge stroke has begun, the pressure on the fuel in the;interi or of Bourdon tube 100;is increased so that ball 120 seats upon seat 119 to prevent the flow of fuel back into conduit 56. This increased pressure-also'forces diaphragm 60 opens and permits a definite amount of fuel to be injected into cylinder 11 throughout the remainder of the volume of the maximum pumping capacity of Bourdon tube so that the amount of fuel pumped to cylinder 11 maybe reduced to .a low value or zero. Thus in the situation where piston 138 is in contact with diaphragm 134..and diaphragm 134 is therefore maintained in its flat position, the maximum charge of fuel will be pumped to cylinder 11. When piston 138 is withdrawn to its position farthest from the fiat position of diaphragm 134, the minimum charge of fuel will be pumped to cylinder 11.

In the above-described m'annerthisinvention provides in efiect a separate pumping and metering means for charging fuel to each cylinder. It is thus readily apparent from the drawings and foregoing description that the apparatus of this invention is simple, accurate, dependable and inexpensive, and that this invention is therefore economically practical for use especially in automotive engines of the passengers car and truck type; The elements of this invention are easily made and do not require any expensive exact machined parts as do the conventional individual fuel injection devices employed in aircraftand diesel engines. It is to be understood that the apparatus of this invention may be employed with any type-of internal combustion engine operating with any number of strokes per cycle or having any number of cylinders, including a single cylinder engine. Likewise his to' be understood that this invention may be employed with stationary or mobile internal combustion engines. Although in the specific embodiment of this invention shown in Fig. 1, the fuel is shown as being charged directly to the individual cylinders, it is to be further understood that the fuel charge may be combined with the air-enteringeach individual cylinder so that a combustible mixture is fed to the cylinder. In this case a spray nozzle or other atomization apparatus would be employed. However, it. is preferable to inject the fuel directly into the individual cylinders, as better engine performance will normally be obtained.

The following is an example of the size and capacity required of Bourdon tube 100 when it is utilized with an automobile engine. A typical automobile engine, for example, may require a gasoline charge which varies from about 0-0.5 cubic centimeter per cylinder. The particular charge required will depend of course upon the s aman '11 particular speed-and'load conditions involved inoperating the automobile. A Bourdon tube which is constructed of steel and which is capable of withstanding a maximum bursting pressure of about 2,000 p. s. i. may be employed. This Bourdon tube has been preformed into an arc of about 200 on a 1.5 inch radius and has a wall thickness of about 0.06 inch. The circumference of the generally elliptically shaped interior of the Bourdon tube in transverse cross-section is about 1.14 inches with a minor axis of about 0.15 inch. By increasing the are of the Bourdon tube about by moving one end of the tube about 0.4 inch while maintaining the other end fixed, the volume of the interior of the Bourdon tube will be decreased by about 0.5 cubic centimeter. Thus about 0.5 cubic centimeter will be discharged from the Bourdon tube due to the change in volume of the tube, providing, of course, that the diaphragm of the adjusting mechanism is main.- tained in its flat position. If a fuel charge of less than 0.5 is required then the diaphragm is permitted to expand a slight amount by adjusting piston 138 so that a quantity of fuel less than 0.5 cubic centimeter is charged to the cylinder. Thus the present invention is ideally suited to intermittently pump accurate minute amounts of liquid. While this invention has been described specifically in connection with its application to liquid fuels and internal combustion engines, it is to be clearly understoodthat the apparatus of this invention may be employed to pump other kinds of liquids in other applications.

What is claimed is:

1. A pump of the character described adapted to inter mittently discharge a definite amount of liquid therefrom which comprises a mounting block, an arcuate tube closed at one end and open at the other end,. the open end of said tube being secured to said mounting block, anarm pivotally mounted on. said mounting block at a position substantially coinciding with the. center of thearc of said tube, the closed end of said tube being secured to said arm, means for turning said arm about its pivot, a source of liquid, said mounting block being provided with an inlet passageway which communicates at one end with the open end of said tube and which communicates at its other end with said source of liquid, said inlet passageway being provided with check valve adapted to permit passage of liquid into the interior of said tube through said inlet passageway at a. predetere mined liquid pressure in said tube and adapted to prevent liquid passing from the interiorof said tube back to said source of liquid, said mounting block being also provided withan outlet passageway which communicates at one end with the open end of said tube, and at the opposite end with a spring loaded valve adapted to permit discharge of liquid from said tube through said outlet passageway at apredetermined liquid pressure in said tube and adapted to close said passageway after.

said liquid is discharged, said mounting block being further provided with a passageway ,communicatingqat one end with the interior of said tube through said outlet passageway, a diaphragm arranged with one side across the other end of said passage in fluid-tight relation therewith, said mounting block being further provided with a chamber bounded on one side by the side of said diaphragm opposite said passage, a piston disposed in said chamber and adapted to be positioned at a variable distance from said diaphragm, means for changing .the position of said pistonin said chamber in relation to said diaphragm.

2 A pump of the character described including a Bourdonrtype, arcuately curved tube having a sealed end, and an'opposite end defining a chambered portion, a fixed mount for said latter end, asupport arm mounted at one end for pivotal oscillation, the other end of said armbeing secured to said tube sealed end, inlet and outlet conduits each having an open end in communication with said tubechambered portion and a flow check means in each conduit holding against pressure in an upstream direction through each conduit, said conduits between said flow check means and with said tube forming a pump chamber, and a means adapted selectively to-vary the discharge volume of said pump chamber, comprisinga passageway defined in the wall of said outlet conduit, said passageway communicating with said conduit and opening outwardly therefrom, a fluid and pressure tight diaphragm closure for said passageway of a material resiliently deformable under pressure, said diaphragm closure disposed across said passageway so as substantially to resist deformation toward said outlet conduit, and an adjustable limit stop adapted to be disposed in variable contact relation to said diaphragm closure sov as to, limit deformation of said diaphragm closure outwardly andaway from said outlet conduit within an adjustable, predetermined limit range.

3 Apump of the; character described including a Bourdon-type, arcuately curved tube having a sealed end, andanoppositeend defining a chambered portion, a fi ed mount. for said latter end, a support arm mounted at one end for pivotal oscillation, the other end of said arm being secured to said tube sealed end, inlet and outlet conduits each having an open end in communication with said tube chambered portion and a flow check means in each conduit holding against pressure in an upstream direction through each conduit, said conduits between; said flow. check means and with said tube forming a pump chamber, and a means adapted selectively to vary the discharge volume of said pump chamber, comprising a cylindrical fitting having a first end secured to one wall of said pump chamber outlet conduit and in substantial communication with said outlet conduit by way of a passageway defined in said wall, a flexible diaphragm separating the interior of said cylinder from said. chamber, said diaphragm being substantially rigidly maintained against flexure toward said chamber, a piston-like limitstop extended into said cylinder through the other end thereof and disposed for reciprocal movement longitudinally thereof, said stop limiting flexure of said diaphragm into said cylinder, resilient means urging said stop longitudinally of said cylinder in one direction; means for moving said stop in an opposite direction longitudinally of said cylinder against the resistance of said resilient means, means for adjusting the extent of reciprocal travel of said stop, and a vent from said cylinder opening therefrom adjacent said diaphragm.

- References Cited in the file of this patent UNITED STATES PATENTS 1,973,180 Scott Sept. 11, 1934 1,982,023 Ritz Nov. 27, 1934 2,019,650 Bischof Nov. 5, 1935 2,040,847 Hesselman, May 19, 1936 2,047,167 Heller July 7, 1936 2,619,907 Paterson Dec. 2, 1952 FOREIGN PATENTS 3,152 Great Britain Dec. 8, 1904 108,77 Great Britain Aug. 23, 1917

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