US1819209A - Mechanism for controlling the supply of liquid fuel to internal combustion engines - Google Patents

Description

Aug. 18, 1931. F. B. STEARNS 1,319,209

MECHANISM FOR CONTROLLING THE SUPPLY OF LIQUID FUEL To INTERNAL COMBUSTION ENGINES Filed May 25, 1925 4 sheets-sheet 1 Snow/"bi Aug. 18, 1931. F. B. STEARNS 1,819,209

MECHANISM FOR CONTROLLING THE SUPPLY OF LIQUID FUEL TO INTERNAL COMBUSTION ENGINES Filed May 25 1925 4 Sheets-Sheet 2 Fig.5.

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g- 1 1931- F. B. STEARNS 1,819,209

MECHANISM FOR CONTROLLING THE SUPPLY OF LIQUID FUEL 1'0 INTERNAL COMBUSTION ENGINES Filed May 25 25 4 Sheets-Sheet 3 INVENTOR ATTORNEY,

Aug. 18, F. B. STEARNS 1,819,209

MECHANISM FOR CONTROLLING THE SUPPLY OF LIQUID FUEL TO INTERNAL COMBUSTION ENGINES Filed May 25 925 4 Sheets-Sheet 4 FIG. 10.

0 JM Invali- M4 an ATTORNEY.

Patented Aug. 18, 1931 UNITED STATES PATENT OFFICE FRANK BALLO'U STEARNS, OF CLEVELAND, OHIO MECHANISM non. CONTROLLING THE SUPPLY on LIQUID FUEL 'ro INTERNAL COMBUSTION ENGINES Application filed May 25,

This invention relates to internal combustion engines of the type in which liquid fuel is injected under pressure into the working cylinder, and more particularly to the valve 5, operating mechanism for controll ng the quantity of fuel which is in ected into the cylinder.

One of the objects of my invention 1s to provide a fuel feeding system, for engines 10 of the liquid fuel type, in which the quantity of fuel which is fed into a cylinder durmg the injection period can be varied by adjustment of the mechanism which operates the needle valve of the fuel injecting nozzle.

1 Another object of my invention is to provide a fuel feeding system, in which mechanism is provided topositively seat and unseat the needle of the fuel injecting nozzle.

Still another object of myinvention is to 20 provide mechanismfor operatingthe needle valve in the fuel feeding systems for engines,

which can be readily adjusted to regulate the timing of the injection period relative to the piston stroke.

25 These and other objects, and the invention itself will be fully described in the following A specification.

In the-accompanying drawings, Fi 1 is a medial sectional view of a cylinder an en- 30 gine showing an embodiment'of my invention associated therewith; Fig. 2 is a side elevation of the same with the gear cover on the engine base in section; Fig. 3 is-a horizontal sectional view taken on line 3-3 of-Fig. 1; 35 Fig. 4 is a' plan view of the needle rocker arm; Fig. 5 is a side elevation of thesame; Fig. 6 is a side'elevation of one of the rocker arms which is associated with the needle rocker arm; Fig. 7 is an end elevation of the same; Fig. 8 is a perspective view of the yoke which is connected with associated needle operating rocker arms; Fig. 9 is a side elevation of a'cylinder with a modified embodiment of my invention shown associated therewith; Fig; 10 is a top plan view of the needle operating mechanism of the modified embodiment of my invention; F i 11 is an enlarged end elevation of the modi ed form of needle operating mechanism; Fig. 12 is an enlarged side elevation of the modified mechanism for 1925. Serial- No. 32,734.

operating the needle; Fig. 13 is an end view of the adjusting mechanism of the modified form; Fig. 14 is an enlarged side elevation of the cam for positively operating the needle operating mechanism; and Fig. 15 is a section of the cam taken on line 1515 of Fig. 14.

Referring to the drawings by charactersof reference, inwhich like characters illustrate similar parts, represents the base of an internal combustion engine upon which a cylinder 21 is secured. A piston 22 is reciprocable in the cylinder and is connected to the crank shaft 23 .by the rod 24. The cylinder head 25 is shown cast integrally with the cylinderand is provided with a centrally located pocket within which the needle cage 26 is seated. A nozzle 27 projects through the base of the head, into the c linder, and is secured against the lower en .of the cage by a cap 28. A needle, or valve member 29 extends through a bore extending axially through the cage and is adapted to seat against the inner wall of the outlet end of the nozzle and close the injection passage extending therethrough. fuel passage 30 extends through the cage and terminates in the vertical bore therein, which bore is o,f a larger diameter than the needle from the point of juncture with the passage to its lower end, thereby permitting the fuel to pass into the nozzle around the needle. Suitable conduits connect the fuel passage with a source of fuel supply. A shaft 32 is carried by the engine base, parallel with. the crank shaft, and is driven therefrom by the intermeshing gears 33 and 34:. The engine so far described is substantially the same as that shown and described in detail in my Patent No. 1,7 22,772, issued July 30, 1929, and reference may be had thereto for such details which may not be described herein, with the exception of'the mechanism for controlling the injection of the fuel which is the subject matter of this invention.

The mechanism for operating the fuel needle 29 is driven from the cam shaft by means of a helical gear 35 which is keyed to such shaft. A shaft 36 extends vertically, parallel to and exteriorly of the cylinder, and projects at its lower end through a beariJ 37 into the interior of the engine base. A bearing 38 is positioned within the housing 41 and the shaft extends at its lower end intermediate the housing and a helical gear 39 which is keyed to the shaft 36. A nut 40 is secured upon the end of the shaft and maintains the gear 39 against vertical displacement. The shaft is so positioned that the helical gear 39 meshes with the helical gear upon the shaft 32 and the shaft 36 is rotated through such gears. A portion of the base is open at the side of the gear 39 and a cover plate 41 is bolted to the base, over such opening, thereby permitting ready access to the interior of the base adjacent the worm gears.

A bracket 42 is secured by'bolts 46 to the top and the side of the cylinder head, and carries the mechanism which is operated by the driven shaft 36 for operating the needle 29. The side portion of this bracket provides a support for the horizontally extending cam shaft 43, and is formed with a bearing 44 within which such shaft is maintained by hearing caps 45 which are secured thereto by studs. A helical gear 47 is keyed to the shaft 43 and the shaft 36 is positioned to extend adjacent thereto, so that a. helical gear 48, which is keyed upon the upper reduced end thereof, will mesh with the gear 47. A castillated nut is screwed upon the upper end of the shaft 36 to retain the gear 48 against vertical displacement. It will be observed that the lead of the teeth of the gears 39 and 48 secured to the shaft 36 are arranged to extend in opposite directions, and that the teeth of the gears 35 and 47 are formed to cooperate respectively therewith.

The upper portion of the bracket is provided with a pair of spaced ribs which are provided with aligned bearings 49 in which a shaft 50 is secured. A rocker arm 51 is arranged to extend intermediate the parallel ribs of the bracket and is provided with a bearing 52 through which the shaft 50 extends. The upper end of this arm is formed to normally extend in substantially a horizontal plane and provide a pair of,spaced guide members 53, while the lower end thereof extends downwardly .at an angle and a pin 54 is secured adjacent the end thereof and projects from one side thereof. A roller 55 for engaging a cam 'groove is carried by the projecting end of the pin 54. The guide members 53 are substantially rectangular in outline and are provided with guideways of a similar outline. A pivoted lever 56 is provided with a bearing 57 which is rotatably mounted upon a shaft 58 secured in bearings 59 in the ends of the ribs which extend from the bracket 42. The outer end 60 of this lever 5 6 is formed similarly in outline to the guide members53 of the rocker arm 51 and when assembled will extend intermediate the same. The guide member 60 is formed with an opening 61, similar to those in the associated guide members, which also serves as a uide way. A substantially square bearing lock 62 extends transversely through each of the guideways in the members 53 and 60 and a pin 63 extends through central. apertures therein, thereby connecting the member 60 with the members 53. The arms 64 of a yoke extend adjacent the outside of the guide members 53 and the ends of the pin 63 ex itend therethrough, being secured against displacement by a cotter key 65. The arms 64 terminate in a stem 66 beyond the outer end of the guide members.

The inner end of the pivoted lever is arranged to reciprocate the needle 29 for opening and closing the injection passage in the fuel nozzle 27. The lever is provided with a vertically extending bore 65 and having its end wall split vertically. The wall forming the bore is threaded and a threaded socket member 66 is mounted in the upper portion thereof. The needle valve 29 extends through a bore in a lower threaded socket member 67 which is mounted in the lower end of the bore 65. The inner faces of the sockets 66 and 67 are concave and engage a ball 68 which is secured to the upper projecting end of the needle. A stud 69 extends through the split ends of the pivoted lever 56 and serves to clamp the pivoted lever against the sockets. By unloosening this stud the position of the sockets can be quickly adjusted vertically, thereby adjusting the position of the needle relative to the pivoted lever.

A housing 70 is arranged to extend in a plane above the needle, and is provided with depending spaced legs 71 having the base thereof turned out. The leg bases bear upon the top of the cage 26 and are secured thereupon by a clamp 72. The clamp is bolted to the top of the engine head by studs 73 and is provided with arms 74 which extend over the base of the bracket legs, and a stud is provided at the fork of the legs to clamp the housing 70 in position upon the cage. By releasing the stud at the fork, the housing and cage can be removed from the engine. The housing is provided with an aperture 75, in alignment with the needle valve when assembled, and a screw cap 76 is provided to close the upper end thereof. A coil spring 77 is mounted in the aperture 75, one end of which bears against the cap and the other end of which engages a flange 78 formed on the upper-end of the socket 66, preferably projecting beyond the base of the lever in which it is secured. The tension of the spring can be varied by adjustment of the cap, and is also utilized for the purpose of cushioning the movement of the valve operating mechanism, thereby relieving some of the strain it is subjected to, and also, assisting the responsiveness of the pivoted lever in the closing operation.

A cam 79, shown in detail in Figs. 14 and 15, is keyed to the shaft 43 which is driven by the shaft 36 fromthe cam shaft. This cam is of the internal groove type and one side thereof is provided with a circling-- groove therein. The hub 81 of the cam is provided with a radially extending recess 82 within which a removable member is secured by a stud 83. The removable member is provided with an abutment 84 which extends into the substantially circular groove 80 and a recess 85 complementary to the abutment is formed in the cam at the opposite side of the groove. The grooved side of the cam is arranged so that the roller 55 carried by the rocker arm 51 will extend into and be positively actuated thereby. The cam, it will be observed, will be retained longitudinally intermediate the crank arm and-the bearings of the bracket adjacent thereto. VVith' engines in which fuel is injected under pressure, the period of time that the needle is unseated to admit a fuel charge is an infinitesimal fraction of a second, and to obtain the best results it is therefore necessary that a positive valve operating mechanism be provided. With this form of cam the recess in the groove insures positive closing of the needle and a definite opening period for the same, as the ends of the recess 85 cooperated with the cam abutment to operate the cam roller in opening and closing.- The closing end of the recess will overcome the inertia on the roller and force it back into the circular portion of the groove immediately when the movement over the abutment surface is completed. It will thus be seen that the arm 51 will remain stationary while the roller rides in the circular portion of. the groove, and that during the period the roller is in engagement with the abutment the arm will be definitely and positively rocked on its pivot.

' The degree to which the needle is lifted from its seat is regulated by the degree to which the pivoted lever 56 is rocked, while the degree to which the rocker arm rocks is controlled by the point on its length at which it is connectedby the pin 63 with the crank lever which is rocked uniformly-by the cam. Thus by moving the yoke arms 64 back or forth, the lift of the needle valve can be reg ulated a greater or less distance, or will not be operated at all. I provide mechanism, preferably hand manipulated, by which the connection of the pivoted crank arm with the pivoted lever can be regulated and maintained. The bracket 42 is provided with an extension 86,'having a bearing 87 into which a shaft 88 is rotatablymounted. A pair of spaced arms 89 are keyed to the shaft 88 and extend upwardly therefrom, the ends of the arms being connected by a pin 90 which is rotatably mounted in apertures adjacent the ends thereof. A wing screw 91 is threaded through the pin 90 and is swiveled 1n the arms and is secured thereto.

shaft 63 can be moved to adjust the relation of the rock arm with the lever arm. A pair of radially extending arms 93 extend from the bearing 87 and an arcuate toothed segment 94 extends intermediate the ends of the A handle 95 is pinned to the shaft 88 and a slidable catch 96 is carried thereby. A spring 97 normally maintains the catch seated intermediate a pair of the teeth on the segment, the catch being removed from the teeth when pressed therefrom byan extension rod 98.

It will be seen that the guideways in the guide members 53 and 60 extend at one end over the pivotal connection of the crank 51, and the pin 63 and its bearings 62 mounted in the guideways can be moved the length of the guideways. By moving the handle 95, the shaft 88 will be rotated, thereby rocking the arms 89 and the pin 90 and thus moving the yoke back or forth. The pin 63 being carried by the yoke, its position will therefore determine the degree to which the arm 56 is rocked by the operation of the rocker arm 51. It will thus be seen'that' when the pin 63 is directly over the shaft 50 that the arm 51 can rock without effecting any movement of the lever 56, so that in such relatiori the needle will remain closed. As the handle is moved upward, the pin 63 will move away from the vertical plane of the shaft 50 and the rocking of the arm 51 will cause the lever 56 to rock. The

further the pin is moved from a plane above sition closing the injection outlet in the nozzle. 'When the lever'95is adjusted so that the desired quantity of fuel will be injected into the cylinder during the explosion period, the

catch is released and will lock with the seg-' ment, thereby maintaining the relation of the crank arms so that the definite quantity of fuel desired to be injected during each explosion operation will remain constant.

I have described mechanism which will positively seat and unseat the fuel in ecting needle, and which can also be adjusted to vary the quantity of fuel which is injected into the cylinder. Associatedwith suchmechanism, I also provide mechanism whereby the timing of the lifting of the needle valve can be readily set indifferent relations to the crank shaft from which it is driven. A bracket 99 is secured to the cylinder b studs 100', and is provided with a bearing 101 which is located to serve as a guide and support for the shaft 36. Another bearing 102 is formed integrally with this bracket, and extends in a vertical plane in spaced relation below the bearing 101. The shaft 36 also extends through the bearing 102, and a cage 103 lextends around the shaft and through the bracket and a pinion 111 is keyed to the shaft.

The pinion is arranged to mesh with the rock 107 carried by the cage. The shaft 109 is carried by similar bearings 112 at each side of the bracket and a hand lever 113 is keyed to a projecting end of the shaft. A bracket 114 is secured to the bearing 102 by studs and carries a toothed segment 115 with which a catch 116 engages. A spring 117 normally causes the catch to'engage the teeth of the segment, and a rod 118 extends from the catch by which the catch can be released from the segment teeth by pressing it inwardly.

The shaft 36 is mounted so that it can be reciprocated vertically, and by moving the hand lever up or down the shaft 109 and the gear 111 will be rotated, thereby reciprocating the rack 107 and with it the shaft 36. The cage 103 is loosely mounted upon the shaft so that the shaft can rotate v while being adjusted vertically. It has been previously point ed out, that the helical gears 39 and 48 carried by the shaft 36 are arranged so that their teeth extend in opposite directions, and thus by moving the. shaft vertically, the relation of the rotation of shaft 36 with the cam shaft and crank shaft will be varied.- In this manner, thetime at which the abutment in the cam strikes the cam roller to rock the needle operating arms will be shifted as desired relative to the rotation of the crank shaft and consequently the stroke of the piston. It will be seen that such adjustment will time the injection period of the fuel sooner or later with respect to the stroke of the piston, while the engine is either inoperative or in operation. The catch 116 will maintain the shaft 36 stationary vertically when the desired timing relation is obtained.

In Figs. 9 to 12, I have illustrated a modified form of another embodiment of my invention which I will now describe.

The stem of the spring seated needle valve 29 which normally closes the fuel passage, extends beyond the top ofthe cylinder head and is reciprocated intermittently by mechanism which is actuated by the cam 79 secured to rotate with the cam shaft 16 located exteriorly ,of the engine base.

engine in any conventional manner, and is provided with a flange17. The QXtGIIOI end face of such flange is provided with radially extending serrations 18 which are positloned to interlock with the serrated face 19 of the cam. The cam is mounted upon a reduced end of the cam shaft 16, which reduced end is rotatably mounted in a bearing bracket 120 secured to the engine by the bolts 121. The cam is provided with arcuate grooves through which studs 122 extend and are screwed into the flange 17, the arcuate grooves being provided so that the cam can be rotated to adjust its relation with the cam shaft without disassembling the adjacent parts, it being understood that the serrated faces are disengaged sufficiently to permit such rotation of the cam when adjusting. The cam in this embodiment can be adjusted only when the engine is not running, and the cam is secured to the cam shaft in such relation that the abutment 84 will actuate the valve operating mechanism at the point in the piston stroke which gives the best results for the variations in the power which is needed.

A bracket 125 is secured to the engine base adjacent the bracket 120, and a rocker shaft 127 is mounted therewith to pivotally support the crank arm 126. One end of crank is provided with a follower 128 which is positioned to ride in the groove 80 in the cam. The other end of the crank arm is bifurcated and is provided with slots 129 which extend arcuately in substantially a horizontal plane to a point over the shaft 127 upon which the arm is pivotally mounted. A bell crank 130 is provided adjacent the slotted end of the crank arm, and a pin 131 projects therefrom and is arranged to extend through the slots. One end of the bell crank extends substantially in a vertical plane and a rod 132 is screwed into an aperture therein. The other end of the bell crank extends in substantially a horizontal plane parallel with the crank arm. The rod 132 is connected to a pivoted rocker arm 160 which is connected to recip rocate the valve needle. The valve will be lifted from-its seat a distance proportionate to the distance the rod is moved downwardly by the crank arm while riding over the abutment 24 of the cam. It will be seen that on each revolution of the cam, the abutment will rock the arm in the same manner as set forth will pass into the cylinder while the needle is lifted and the distance the valve is moved from its seat will-determine the quantity of fuel injected.

In this embodiment the quantity of fuel injected can be varied by mechanism for regulating the distance the valve rod ,is moved by the crank arm, and I utilize, preferably, hand operated mechanism for this purpose. A hand lever 133 is secured at its base, to a shaft 134; which is pivotally carried by a bracket 135 A link 136 is also secured at one end to the shaft 134 and the other end' movement of the bell crank will move the pin .131 in the slot 129." When the pin 131 is in the same vertical plane with the shaft 127, the bell crank and the rod 132 will not be moved verticallyby the rocking of the pivoted crank 126, and in such relation the valve will not be opened. As the pm 131 of the bell crank is moved away from the shaft 127, the bell crank will be vertically reciprocated the same distance as the throw of the pivoted lever at the point at which the pin 131 is positioned. It will be seen that the throw of the lever increases toward its end, so that the rod 132 will be reciprocated the greatest distance when the pin 131 is positioned at the end of the slot removed from the shaft 127. The throw of the cam is suflicient to admit the desired quantity of fuel to develop the maximum power which the engine is designed to develop.

A curved bracket 140 is secured by studs 141 to the side of the cylinder, and is provided with a slotl43 through which a screw stud 144 extends. The stud 144is screwed into the hand lever 133, so that when the stud is tightened the hand lever is secured stationary. When the stud is loosened the hand lever is free to adjust the bell crank pin in any position in the slot 129, thus regulating the movement of the rod 132 and the distance the valve is unseated.

It will be seen, that I have provided a simple device which can be easily adjusted to inject a desired quantity of fuel into the cylinder, and which can also be adjusted in the same manner to render the mechanism ineffective for unseating the valve.

Various changes can be made in the construction of the described embodiment of my invention without departing from the spirit 7 of the invention and the scope of the appended claims.

I claim: 1. In a valve operatlng mechanlsm for 1nternal combustion engines, a liquid fuel injecting valve, operating mechanism therefor, power transmission mechanism between the crank shaft ofthe engine'and the valve opcrating mechanism, including a rotary element and a pair of opposed helical gears mounted for rotary and axialmovement in unison, a helical gear in driving connection with the rotary element and inmesh with one .of said pair of helical gears, a helical gear in driven connection with the engine crank shaft and meshed with the other of the pair of helical gears, means for moving the helical gears axially to advance the rotary element a fraction of a revolution on its rotational axis to change the time relative to the rotation-of the engine crank shaft at which valve movement for fuel injection occurs and means cooperating with the valve operating mechanism to change the amount of valve movement independently of the time of said movement. I

2. In a valve operating mechanism for internal combustion engines, a liquid fuel injecting valve, valve operating mechanism therefor, power transmission mechanism between the crank shaft of the engine and the valve operating mechanism, including a rotary cam a pivoted cam lever, a cam follower on one side of the pivot and on the other side of the pivot a connection between the lever and the valve for operating it, a pair of opposed helical gears mounted for rotary and axial movement in unison, a helical gear having driving connection with the cam to rotate it and meshed with one of the pair of helical gears, a helical gear having driven connections with the engine crank shaft and meshed with the other of the pair of helical gears, manually operable means for moving the helical gears axially to advance the cam a fraction of a revolution on its rotational axis to change the time relative to the rotation of the crank shaft at which fuel injection occurs and means for adjustably changing the effective length of the cam leveron the side of the pivot opposite the cam follower to change the amount of fuel injection.

3. In a valve operating mechanism for internal combustion engines, a liquid fuel injecting valve, valve operating mechanism for opening and closing the valve, power trans operable means for moving thehelical gears axially toadvance thecam a fraction of a revolution on its rotational axis to change the time relative to the rotation of the crank shaft at which the fuel valve opens, and means for adjustably varying the amount of movement of the valve operating mechanism to vary the amount of'opening movement of the valve to vary the amount of fuel injected independently of the timing of the injection.

4:. In a valve mechanism for an internal combustion engine, a fuel valve, a rocking valve lever, one arm of which is connected to the valve, the other arm of which is bifurcated, a transversely arranged lever-moving pin in the bifurcation, moving-means for periodically moving the pin to rock the lever and operate the valve, and adjusting-means for moving the pin in the bifurcation to vary the throw of the lever for varying the amount of the valve movement, said pin-moving means comprising a pivotal lever, provided on one side of the pivot with a bifurcation normally substantially parallel with the bifurcation of the valve lever and enclosing said pin, and on the other side of the pivot provided with a cam follower, a rotary groove type cam for the follower adapted to intermittently give an impulse to the follower to rock the cam lever to move the pin transversely of the bifurcation and rock the valve lever, said pin adjusting means comprising a link connected at one end to the said pin and at the other end to operable means for adjustably moving the link to cause the pin to be adjust-ably moved along the parallel bifurcations of the cam lever and of the valve lever, and means for fixing the link in any said adjusted position, the said bifurcations and the said groove type cam positively seating and unseating the valve and preventing over-travel thereof at all speeds.

5. In a valve mechanism for internal combustion engines, a fuel valve, a rocking valve lever connected to the valve and provided with a double guideway, means for moving the valve lever comprising a cam operable pivoted lever provided with a double guideway on one side of the pivot normallysubstantially parallel with the guideway of the valve lever, a double track cam and a cam follower between the tracks on the side of the pivot for operating the cam lever, a connecting element pivotally connecting the two guideways and movable longitudinally thereon, whereby when the lever is moved by the cam its motion is transmitted through the connecting element to the valve lever to rock the same, and means for adjustably varying the throw of the valve lever to adjustably vary the amount of opening of the valve, said means comprising a link connected to said connecting element for moving the element longitudinally on both of said ways simultaneously when in their parallel relation, the said double guideways and double track cams efi'ectmg positive seating and unseating of the valve and preventing overtravel thereof at all speeds.

Signed at Cleveland, in the county of Guyahoga and State of Ohio, this 28th day of Aprll, 1925.

FEANK.BALLOU STEARNS.

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