US2312212A

US2312212A - Governor

Info

Publication number: US2312212A
Application number: US350394A
Authority: US
Inventors: Herbert C Edwards
Original assignee: Timken Roller Bearing Co
Current assignee: Timken Co
Priority date: 1940-08-03
Filing date: 1940-08-03
Publication date: 1943-02-23
Anticipated expiration: 1960-02-23

Description

Feb. 23, 1943. H. c. EDWARDS 2,312,212-

GOVERNOR I Filed Aug. 3, 1940 4 Sheets-Sheet l Feb. 23, 1943- H. c. EDWARDS ,3 2 2 GovERNdR Filed Aug. I5,- 1940 4 Sheets-Sheet 2 Fen 23,1943. ,H. c. E wx s GOVERNOR- Filed Au.

.3,- 1940 4 sheetsshe eif t" N/AwroR:

1/15 41-1-0 ma i Patented Feb. 23, 1943 UNITED STATES PATENT OFFICE Herbert C. Edwards, Massillon, Ohio, assignor to The Timken Roller Bearing Company, Canton, Ohio, a corporation of Ohio v Application August 3, 1940, Serial No. 350,394

'lClaims.

- This invention relates to speed regulating devices for internal combustion engines and more particularly centrifugal speed governors for controlling the output of fuel injection pumps for One of the princompression ignition engines. cipal objects of the present invention is to provide a completely enclosed self-contained governor that will hold the engine at correct and uniform idling speed, that will limit the top speed of the engine and that will allow the operator full control over the engine between idling and top speeds. Other objects are to provide for adiusting the idling and high speeds of the engine and to enable such adjustment to be made outside of the governor housing, to incorporate in the governor means for completely shutting off the flow of fuelto the engine and to provide for simplicity. and cheapness of construction "of the governor and ease of assembly of the parts thereof. The invention consists in the governor and in the construction, combinations and arrangements of parts hereinafter described and claimed. 1

In the accompanying drawings, which form part of this specification and wherein like symbols refer to like parts wherever they occur,

Fig. 1 is an outer end view of a speed governor embodying my invention, Fig. 2 is aside elevational view of said governor.

Fig. 3 is a vertical central longitudinal section through said governor on the line 3-3 in Fig. 1, the governor-being shown associated with the cam shaft and fuel feed control rod of the fuel injection pump for a compression ignition engine,

Fig. 4 is a vertical transverse section through i the governor on the line 4-4 in Fig. 2,

Fig. 5 is a similar section on the line 5--5 in- Fig. 2; and i Fig. 6 is :a fragmentary vertical section along the line 6-4 in F 5.

The centrifugal speed regulating device or governor shown in the accompanying drawings comprises a housing A adapted to be removably seicuredto one end of a fuel injection pump, of *whichonly the horizontally reciprocatory fuel control rod B and the horizontal'cam shaft C :are shown. The cam shaft C .is adapted to be driven by or inunison with the engine (not shown) supplied by said pump; and the fuel feed con- =trol rod B is slid in the direction of the governor to decrease the quantity of fuel supplied to said engine and is slid in the opposite direction to =increase'the fuel supply.

-.5 shown in Fig. 3 of the drawings, the pump opposing end wall of the governor housing A has vertically spaced openings I and 2 extending horizontally therethrough adapted to receive the ends of the fuel feed control rod 13 and cam shaft C, respectively, of the fuel injection pump. Fixed to the portion of the cam, shaft C located within the governor housing A is a gear 3 which intermeshes with a pinion 4 located directly thereabove on a horizontal shaft 5 that extends longitudinally of said housing. The inner end of this pinion or governor shaft 5 isrotatably supported in a taper roller bearing 8 mounted in an annular seat I provided therefor in the pump opposing or inner end wall of the governor housing; and said shaft extends through an opening 8 in the outer end wall of said housing and has its outer end journaled in a tapered roller bearingil mounted in a cap II! that is removably secured by cap screws I l to said outer end wall over said opening.

A thrust sleeve is slidably mounted on the governor shaft 5 and is adapted to be slid outwardly therealong by means of a pair of weighted centrifugal levers. l3 that are pivotally supported, as

at M, for swinging movement towards and away from said shaft, on a spider l5 rigid therewith.

Each of the centrifugal levers I3 is provided at the and remote from its weighted end with a finger l6 adapted, when said lever swings outwardly, to exert an end thrust on the inner end of the thrust sleeve l2 and with a second finger ll adapted to abut against the spider l5 and thus limit the outward swinging movement of said lever. Mounted on the thrust sleeve l2 between an annular shoulder l8 thereon and the outer end thereof is a suitable ball thrust bearing l9 located in an annular sleeve or 'casing 20 having an external peripheral annular groove 2| therein.

1a cupped washer 26 sleeved on the governor shaft; and this spring seat is held by said springs against ahorseshoe or C-washer 21 that straddles said shaft between said spring seat and the inner end of the outermost roller bearing 9 for said shaft. The tension of the two

high speed springs

22 and 23 is adjusted by inserting shims 28 in the cup-shaped spring seat 26 for the outer ends thereof. Surrounding the two high speed springs is a third compression coil spring 29, hereinafter referred to as the auxiliary idling speed spring, one end of this spring seating against an annular shoulder 30 provided therefor in the supporting cap ID for the outermost roller bearing 9 and the other end bearing against an annular seat 3| provided therefor in the opposing end of the outer casing 20 for the roller thrust bearing IS.

The fuel feed control rod B of the pump is shifted axially to vary the quantity of fuel delivered by the pump to the engine by means of a manually operable control or throttle lever 34 located outside of the governor housing alongside either side wall thereof. This lever is fixed to the exposed end of a horizontal control or throttle shaft 35 that is disposed crosswise of the governor shaft 5 beneath the governor actuated ball thrust bearing l9 thereon. The ends of this throttle shaft are journaled in bushings 36 that fit within alined circular openings 31 provided therefor in the opposite side walls of the governor housing A and have outstanding flanges 36 at their outer ends that are rigidly secured by means of suitable screws 36 flatwise to the outer faces of said side walls. The portion of the throttle shaft 35 between its supporting bushings 36 is offset radially to form a crank 40 and has a pair of ears or lugs 4| that extend radially from said shaft on the side thereof remote from said crank and in line with the ends thereof.

A yoke lever 42 has its lower end disposed between the longitudinally spaced ears 4| of the throttle shaft 35 opposite the crank portion 40 thereof; and said end of said lever is pivotally supported between said ears on a pivot pin 43 that extends through registering openings provided therefor in said ears and said end of said yoke lever. The yoke lever pivot pin 43 is held in place by a head 44 at one end thereof and a cotter pin 45 that extends through the other end thereof. The yoke lever has an opening 46 that extends therethrough intermediate the ends thereof in a direction transverse of the pivot pin 43. The governor shaft 5 extends through the opening 46 in the yoke lever and the ball thrust bearing I9 is also disposed in said opening. As shown in Fig. 4 of the drawings, the yoke lever is provided on opposite sides of the opening 46 therein with axially alined horizontally disposed trunnions or pins 41 that project inwardly into said opening and seat in the annular groove 2| in the annular casing 20 of the ball thrust bearing |6..

The yoke lever 42 extends above the ball thrust bearing l9 and terminates on either side of a vertical plane passing centrally .through the governor shaft in an outstanding lug. or ear 46 that has an adjustable link connection with the end of the fuel feed control rod B that extends into the governor housing through the opening I provided therefor in the pump opposing end of said housing. This link or turn buckle connection comprises an end fitting 49, having one end secured by a horizontal pivot pin 49a to the lug 46 at the upper end of the yoke lever, an end fitting 60, having one end secured by a horizontal pivot 6| to the adjacent end of the fuel feed control rod B, and a connecting rod 52 threaded into the adjacent ends of said fittings. As shown in Fig. 3 of the drawings, one end of the rod has a right hand thread and the other end has a left hand thread, whereby rotation of said end fittings 46 and 50. The connecting rod 52 has a notched wheel 53 rigid therewith intermediate between the ends thereof; and the top 1 of the governor housing has an opening 54 extending therethrough above the wheel, whereby a suitable tool may be inserted into the housing to engage and rotate said wheel. This opening is closed by means of a threaded plug 55. notched wheel is releasably held in the desired position of rotary adjustment by means of a bowed leaf spring 56 that spans from end fitting to end fitting and bears against the notched.

periphery of said wheel. One end of this spring is riveted to one of the end fittings of the connecting link and the other end has a longitudinal sliding connection with the other end fitting.

A suitable fuel conduit 51 extends horizontally through the upper portion of the governor housing from end to end thereof along the vertical center line thereof and serves as a fuel inlet or by-passageway for the pump. A coil compression spring 66, hereinafter referred to as the idling speed spring, has one end seated in a hollow screw 66 that is threaded through the outer end wall of the housing above the bearing supporting cap I. The other end of the idling speed spring 56 seats in a recess 60 provided therefor in the opposing end face of the yoke lever 42.

- manually shifting the fuel feed control rod B in rod causes relative endwise movement of the twothe direction of decreased fuel to completely out off the fuel supply to the engine and thus stop the operation thereof. This mechanism comprises a horizontal shaft 6| that extends transversely of the governor housing through one of two alined openings 62 located one in each side wall of said housing, the other opening being closed by a suitable closure plate 62a. As shown .in Fig. 5 of the drawings, the stop shaft 6| is iournaled in a bushing 63, which is mounted inthe opening 62 and has a flange 64 at the outer end thereof that seats flatwise against the outer face of the side wall of the governor housing. An annular plate 66 is sleeved on the stop shaft in abutting relation to the flange 64 of the bushing 63 and said flange and plate are secured together and to the side wall of said governor hous-' ing by screws 66. The stop shaft 6| extends out- .wa-rdly beyond the annular plate 65 and has a" stop lever 61 secured thereto. The stop lever 61" and shaft are provided with interfitting longi-Q tudinal ribs and grooves 66, whereby said lever,-

may be angularly adjusted relative to the shaft; Movement of the stop lever 61 endwise of the stop shaft 6| is prevented by means of a pin 6! that extends transversely through the hub of .said lever and seats in an annular groove I6 provided therefor in said shaft.

The stop shaft 6| extends inwardly beyond the inner end of its supporting bushing 62 and has the hub of a stop finger 1| mounted thereon between said end of said bushing and a cotter pin I2 extending through said shaft between theinner end thereof and said hub, said shaft and hub having interfitting longitudinal ribs and grooves which permit relative angular adjustment thereof. The finger 1| is adapted to swing upwardly and outwardly into engagement with one end of the pin 6| that pivotally connects the end fitting 60 of the connecting link to the fuel feed control rod. The finger H is normally held clear of the pivot pin 5| by means of a torsion spring 13 that is. sleeved on the bushing 6| and the hub of said finger, with one end anchored The.

to said bushing and the other end anchored to said hub. The pin engaging edge of the finger -H is convexly curved, as at I4, to contact with the pin ii in a plane passing horizontally through the axis thereof.

The governor is also provided with a stop mechanism for limiting the movement of the fuel feed control rod in the direction of maximum fuel feed. As shown in Figs. and 6, this control rod stop mechanism comprises a screw 15 that is threaded downwardly through the top 'of the governor housing adjacent to the end of id rod and terminates in a ball-shaped lower end portion 16 which bears against one arm of a rock lever 11 which is held against said end by a torsion spring 18. As shown in the drawings, the rock lever 11 is rotatably supported on a horizontal pin located in an opening I! provided in the side wall of the housing; and the torsion spring 18 is coiled around said pin between said lever and a head said pin 3i, with one end anchored to said lever and with the other end bearing against an abutment 32 on the underside of the top of the housing." The pivot pin or stud If is secured within the opening 19 by means of a nut 43 threaded on the outer end of said stud. The opposite side wall of the housing is provided with an opening 79a similar to and in alinement with the opening 13 for the stud 3i, whereby the stud may be mounted in either side wall of the housing. The opening 19a is closed by a closure cap 34.

As shown in Fig. 2, the throttle lever 34 has a split hub portion 34a and. a clamp bolt 34b extending therethrough, whereby said lever may be firmly clamped to the throttle shaft 35'. The hub of the throttle lever 34 is provided with a radially' extending lug 85 adapted in one the lever to abut against an idling speed stop pin :36 and another position of said "against a high speed stop screw 31. The idling speed stop 83 is fixed to a plate 38 that is interposed between the hub of the throttle lever .;34'and the adjacent throttle shaft bushing 33 ,and has an opening for the throttle shaft 35; "and the high speed stop screw 31 is threaded through a lug 39 on said plate with one end in position to be engaged by'the lug 35 on the hub f flthethrottle lever 34. This plate is secured .,.to the bushing 36 by the securing screws 34 ftherefor and has a circular series of holes 30 "thereon, whereby said plate, together with the stops it and 81, may be angularly adjusted relative to the hub of the throttle levers. I For convenience in assembling the;parts of the governor, the governor housing A is split verti- '1 cally in two sections, as shown in Figs. 2 and 3. "The inner housing section li is adapted to be ibolted directly against the end of the fuel injec- ;,tion pump and "and the fuel feed control rod stop mounted :therein; and the outer section 82 is secured to isaid inner section by dowel pins 83 and cap ,screws 94.

Theoperation of the hereinbefore described "speed governor is as follows: The governor comes into operation only at maximum and idling en- 'g'ine speeds, at all other times the operator controls the speed of the engine by manipulating the f throttle lever 34 and thuscause the yoke lever 42 to pivot about the trunnions n that extend .into the annular groove 2| in the casing 23 of jfthe hall thrust bearing i9. when the throttle 'i'lever 34 is swung in the direction of the idling lever to abut has the fuel cut-off mechanism swings in the direction of the outer end wall of the governor housing and pulls the fuel feed control rod in the direction of decreased fuel feed; and when said throttle lever is swung in thedi- 5 rectiun of the high speed stop 31, the upper end formed on the inner end of position of p speed stop, the upper end of the yoke lever 42 of said yoke lever swings in the direction of the pump opposing end wall of the governor housing and thus pushes said fuel feed control rod endwise in the direction of increased fuel feed. when the centrifugal governor weights i3 are closed and the thrust sleeve I2 is in abutting relation to the fingers ii of the weights, the ball thrust bearing is is spaced away from the seat 24'for the inner ends of the two

high springs

22 and 23, this space constituting the idling speed range of said thrust sleeve and said weights. In this position of the thrust sleeve, the two high speed springs are inoperative and the governor weights operate on the thrust-sleeve when the speed of the engine increases to thereby slide said sleeve outwardly along the governor shaft 5 and thus cause the yoke lever 42 to swing about the crank pivot pin 43 of the throttle shaft 35 as a center and move the fuel feed controlrod in the direc-, tion of decreased fuel feed. During the operation of the governor in the idling speed setting thereof, the idling speed spring 58 yieldably resists outward swinging movement of the governor weights l3 and thus operates to maintain a proper uniform idling'speed, while the auxiliary idling speed spring 29 serves to prevent delay in the fuel feed rod movement when the throttle lever 34 is moved towards high speed when the engine is operating within the idling speed range. Above idling speed, the two high speed springs 22 and 23 are placed under compression by the pressure of the ball thrust bearing is against the inner spring seat 24, spring 58 and the auxiliary idling speed spring 29 because of their much greater loading; and

the governor operates to limit the engine to a predetermined top speed.

When it is desired to stop the engine, the stop lever 61 is rotated against the force of the coil torsion spring I3 to swing the stop finger 'li upwardly into engagement with the pivot 5i that connects the connecting link to the fuel feed control rod, thus shifting said rod far enough in the direction of decreased fuel feed supply to completely cut off the flow of fuel to theengine. The notched wheel 53 of the connecting link or turn buckle may be rotated to lengthen or shorten en said link. If the fuel feed control rod comes to a full open position too soon the link is shortened and if the reverse is true, the link is lengthened. The high speed stop screw 81 may be adjusted so that, when the thrust bearing I8 is in contact with the spring seat 24, full travel of the fuel feed rod is obtained when the lug '35 on the throttle lever 34 strikes said stop screw. When the throttle lever 34 is set for normal full load operation of the engine, the rock lever 'l'i serves as a maximum fuel feed stop for the fuel feed control rod. However, in the event that the engine is overloaded while operating at the desired maximum speed, the engine speed decreases, thus decreasing the compressive force of the governor on the two high speed springs 22 and 23. This decrease in the endwise pressure of the governor on the two high speed springs causes said springs to increase the force transmitted thereby to the rock lever 11 through the yoke lever 42 and the

link connection

43, 52, Ill and II with the fuel feed control rod 3. This increased force or pressure of the pin Ii against thus dominating the idling speedthe rock lever or arm 'I'I causes the upper, stop screw engaging branch thereof to bend or spring downwardly, thereby permitting further movement of the fuel feed control rod B in the direction of increased fuel feed and thus increasing the quantity of fuel delivered to the engine and providing increased torque sufficient to carry the overload. Thus, at low speed, the increased force transmitted by the

springs

22 and 23 to the rock lever or arm 11 is sufilcient to bend or distort the same and thus increase the fuel feed, while at high speeds, such force diminishes due to the endwise pressure of the governor on said springs and permits said rock lever to spring back to its normal shape and thus shift the fuel feed control rod B back to its normal maximum fuel feed stop position.

In assembling the governor, the inner end section SI of the governor housing A with the stop mechanism and the fuel out off mechanism mounted therein is attached to the end of the pump The connecting link, including the end fittings 49 and 50 and the rod 52 is then attached to the fuel feed control rod B and the gear 3 fixed to the crank shaft C. The governor shaft and its bearings I and 9, the yoke lever 42, the high speed springs 22 and 23 and the auxiliary idling speed spring 29 are then inserted in place. Then the connecting link is secured to the yoke lever. After this, the outer section of the housing 92 is secured to the inner section 9| thereof. The throttle shaft 35 is then inserted in the large openings in the sides of the governor housing for the bushings 36 and the lower end of the yoke lever 42 is positioned between the lugs 4| on said shaft and secured thereto by the pin 43. The

bushings 3G for the throttle shaft are then inserted in the holes in the side walls of the governor housing. The bearing cap it is then secured to the outer end wall of the governor housing, the idling spring 58 and its supporting cap screw 58 are then mounted in place and said spring adjusted for tension after the governor has been put into operation in order to obtain satisfactory idlingspeed.

Obviously, the hereinbefore described governor admits of considerable modification without departing from the invention, Therefore, I do not wish to be limited to the precise details shown and described, except as required by the appended claims.

What I claim is:

1. A speed governor for an internal combustion engine, said governor comprising a shaft adapted to operate in unison with said engine, a thrust sleeve slidably mounted on said shaft and adapted to be moved longitudinally thereof in response to the speed thereof, a lever adapted to be actuated in one direction by such movement of said thrust sleeve, a spring associated with said lever for yieldably resisting the movement imparted thereto by said thrust sleeve, a link adapted to operatively connect said lever with a fuel feed control member for said engine, said link connection including a pin extending laterally therefrom, manually operable means for actuating said lever to vary the position of said fuel feed control member, a stop in position to be engaged by said pin to establish a normal maximum fuel feed position for said lever, and a manually operable spring retracted member mounted for swinging movement lengthwise of said link into engagement with said pin to thereby move said link connection and the lever and against the resistance of said spring to fuel shutoff position.

2. A speed governor for internal combustion engines, said governor comprising a shaft adapted to operate in unison with said engine, a thrust sleeve slidably mounted on said shaft and adapted to be moved longitudinally thereof in response to the speed thereof, a lever pivoted for swinging movement lengthwise of said shaft and adapted to be actuated in one direction by said thrust sleeve, a coil compression *spring mounted on said shaft for yieldably resisting movement imparted to said lever by said thrust sleeve, a link pivotally connected at one end to said lever, a pivot at the other end of said link adapted to connect said link to a fuel feed control member for said engine, a stop in position to be engaged by said pivotal connection to establish a normal maximum fuel feed position for said lever, said stop being yieldable under the influence of said spring when the latter is relieved of the pressure of said sleeve to thereby permit fuel feed movement of said lever beyond the normal maximum fuel feed position thereof 'and means cooperating with said pivotal connection between said link and said fuel feed control member for moving said link and lever against the resistance of said spring, said means comprising a rock shaft disposed transversely of said link, a lever for operating said shaft, 8 finger fixedto said shaft for movement lengthwise of said link into and out of engagement with said pivot, afixed bushing rotatably supporting said rock shaft, and a coil torsion spring connection between said rock shaft and bushing for yieldably holding said finger out of engagement with said pivot.

3. A speed governor for an internal combus tion engine, said governor comprising a shaft adapted to operate in unison with said engine. said governor comprising a thrust sleeve mounted on said shaft and adapted to be slid longitudinally thereof in response to the speed thereof, a thrust bearing mounted on said thrust sleeve for movement therewith longitudinally of said shaft, a lever pivotally supported at one end andadapted to be operatively connected atits other end to a fuel feed control memberfor said engine, said lever being pivotally connected between said ends with said bearing, whereby by vary the position of the fuel feed controlmember connected to said other end of said lever, a high speed coil compression spring mounted around said shaft and operable to yieldably resist the movement imparted to said lever by said thrust bearing after a predetermined movement of the latter, and two idling speed springs for yieldably resisting movement imparted to said lever by said thrust sleeve prior to the resistance offered by said high speed spring, one of said idling speed springs cooper-' ating with said lever adjacent to its point of connection with said fuel feed control member,"

the other of said idling speed springs surrounding said high speed spring and cooperating with said thrust bearing to resist longitudinal move'-' ment thereof due to the thrust reaction of said fuel feed control member thereon whenever said fuel feed control member connected thereby lever is bctuated by said manually operable the speed thereof to move said lever against the resistance of said spring in the direction of decreased fuel feed, and a stop for establishing a normal maximum fuel feed position for said lever, said stop being yieldable under the infiuence of said spring when said spring is relieved of the pressure of said sleeve and is thereby free to exert pressure sufficient to overcome the resistance of said yieldable stop and permit further fuel feed movement of said lever beyond the normal maximum luel feed position thereof.

5. A speed governor for internal combustion engines, said governor comprising a shaft oper ating in unison with said engine, a lever adap to control the quantity of fuel supplied to said engine, a spring for urging said lever in the direction oi increased fuel feed, a i v t sleeve slidably mounted on said shalt an adapted to be moved longitudinally thereof in response to the -1-. thereof tomove said lever against the resistance of said spring in the direction of decreased fuel feed, manually operable means for actuating said lever to vary the fuel food, menu ally operable means for moving said lever against the resistance of said spring to, fuel cut-ed position, and an. adjustable stop for establishing a normal maximum fuel feed position ior said lever, said stop being yieldable under the iii-=1 fiuence of said spring when said spring is-relieved of the pressure of said sleeve and is thereby tree to exert pressure sufilcient to overcome the re sistanee of said yieldable stop and permit lur ther fuel teed movement of said lever beyond the normal maximum fuel feed position there oi, said stop being adapted to return to its norroal position when said spring is again subjected to are pressure of said sleeve to. thereby return said lever to normal'maidmum fuelieed position.

d. A speed governor for internal combustion engines, said governor comprising a shalt oper ating in unison with said engine, a lever adapted to control the quantity of fuel supplied to said engine, a spring for urging said lever in the di= rection oi increased fuel feed, athrust sleeve slidabiyinounted on saidshatt and adapted to be moved lonaitudin thereof in response to the speed ther to move said lever against e resistance of said spring in the direction oi de creased fuel feed, manually operable means for actuating said lever to vary the fuel iced, menually operable means for moving said lever against the resistance of said spring to ifuel out 0E position, and a stop for establishing a nor mal maximum fuel feed position for said lever, said stop comprising a pivotal armand an abutment therefor, said arm being engaged with said abutment in said normal maximum fuel feed position of said lever, by the pressure of said spring, said arm being yieldable under the influence of said spring when said spring is relieved of the pressure of said sleeve and is thereby free to exert pressure sufdcient to overcome the resistance of said yieldable arm and permit further fuel feed movement oi said lever be yond the normal maximum iuel feed position thereof, said yieldable arm being adapted to return to its normal position when said spring is again subjected to the pressure of said sleeve to thereby return said fuel feed control lever to normal maximum fuel feed position.

7. A speed governor for internal combustion engines, said governor comprising a shalt oper ating in unison with said engine, a lever, a linis pivotally connected at one end to said lever and adapted for pivotal connection at its other end with a. fuel feel control member for said engine, a spring for urging said lever in the direction of increased fuel feed, a thrust sleeve slidably mounted on said shalt and adapted to be moved longitudinally thereof in response to the speed thereof to move said lever against the resist ance of said spring in the direction of decreased fuel feed, manually operable means for actuat ing said lever tovary the fuel feed, manually operable means engaaeable with the pivotal connection between said lint: and fuel teed con trol member for moving said lever against the resistance of said spring to fuel cut-oh position,

and a stop for establishingta normal maximum fuel i'eed position for said lever, said stop com prising a rock/arm and an abutment therefor,

said arm being movable by said pivotal conned tion into engagement with said abutment in the normal maximum fuel feed position of said leve said arm being yieldable under the influence of said spring when said spring is relieved of pressure of said sleeve and is thereby tree exert pressure sufficient to overcome the resist ance of said yieldable arm and pet turther fuel feed movement of said lever beyond normal maximum fuel feed position thereof, said arm being adapted to return to its normal posi tion when said spring is again subjected the pressure of said sleeve to thereby return said lever to normal maximum :luei feed position.