US2139832A - Governor for internal combustion engines - Google Patents

Description

Dec. 13, 1938. w. E. LEIBING GOVERNOR FOR INTERNAL COMBUSTION ENGINES Filed Sept. 19, 1956 3 Sheets-Sheet l Dec. 13, 1938.

W. E. LEIBING GOVERNOR FOR INTERNAL COMBUSTION ENGINES Filed Sept. 19, 1936 3 sheets-sheet 2 "I III llllllllllfl 4 3 wu WWW WWW/bl)? E Lab/W Dec. 13, 1938.

W. E. LEIBING GOVERNOR FOR INTERNAL COMBUSTION ENGINES 19, 1936 5 Sheets-Sheet 3 uad m bun awe/whom h W/mm Z7. Law/27y MM 9 %WM Patented Dec. 13, 1938 UNITED STATES PATENT OFFICE GOVERNOR FOR INTERNAL COMBUSTION ENGINES Application September 19, 1936, Serial No. 101,665

11 Claims.

The present invention relates to governors for internal combustion engines andmore particularly to devices for governing or limiting, to a predetermined maximum, the speed of vehicles 5 driven by internal combustion engines.

It is a primary object of the present invention to devise a practical and eflicient governor for location entirely externally of the conduit or manifold through which the combustible mixture 10 passes but which is responsive to conditions within the engine. This object is accomplished by associating the governing device with the accelerator mechanism and the carburetor throttle so that the latter is responsive both to manual 15 control and to changes in pressure (vacuum) within the engine intake manifold.

Heretofore all marketed forms of governors have embodied a valve device in addition to the conventional throttle valve and like the latter,

343 located within the intake manifold. When such devices are installed in the modem or most widely used carburetor, conditions result which are often undesirable and which require correction, due to the fact that an auxiliary valve is 35 located in the intake conduit and cannot perform its governing function without disturbing the normal function of the carburetor. The modern carburetor depends for correct mixture, at speeds corresponding ,to normal governed speeds, on

39 the position of the carburetor throttle which, de-

pending upon its position, controls the flow of fuel through both the main jets and the low speed or closed throttle jets. For example, a speed, of 2500 R. P. M. on the engine, when con- 55 trolled by the carburetor throttle calls for a. considerable amount of the fuel to be furnished by the closed throttle jets, and only a portion of the fuel from the main jets. At such a speed, however, with a governor blade placed between the i carburetor and the engine, the carburetor throttie is usually held by the driver in a wide open position and therefore the lay-pass around the carburetor throttle is inoperative and only the main jets are providing the fuel. This loss of L fuel causes the engine speed to fall ofi from the desired governed speed and the governor to surge back and forth, not from any fault of the governor setting, but solely because the carburetor throttle is not in the proper position to produce the correct air-fuel ratio for the amount of air passing through the carburetor.

It follows that inasmuch as the carburetor requires the throttle valve to be varied to obtain correct running mixture, a governing device acti5 ing directly upon the carburetor throttle would have some advantages over a governor of the type embodying a. valve within the intake conduit.

Accordingly, it is a major object of the present invention to provide a governor that may be installed without disturbing the proper mode of functioning of the carburetor.

Another important object is to provide a governor installation wherein the load on the engine at any throttle position is capable of causing the throttle to open in a manner substantially eliminating any possibility of stalling the engine. signing the governor that the throttle valve will surge toward open position in response to decreased vacuum caused by increased loads. In this connection it is a further important object to provide means for limiting the surge so that the vehicle will not accelerate too rapidly, particularly from a standing start.

It is a further object to provide a governor that may be installed adjacent the carburetor side of the engine without disturbing the air cleaner, brackets, etc., that are at present attached to the carburetor as a part thereof.

It is a further major object of the present invention to provide a governor mechanism connected directly to the engine throttle and responsive to varying vacuum conditions and to springs, but which has a follow-up action and causes no increased resistance to throttle rod opera tion. 7

Another object of this invention resides in the provision of a governor having a momentary over-run or full-flow action. This is accomplished by associating the governor with emergency means whereby for a controlled short period of time the full performance of the engine is obtainable to permit a momentary vehicle speed in excess over that of the normal governed speed. Many persons, including legislators and makers and users of automotive vehicles, object to the use of speed governors because of their belief that many collisions and accidents are avoidable by the sudden and immediate use of speed to the full capability of the vehicle. The present invention contemplates a device which meets this objection to the use of a governor.

A further object of my invention is to provide means for preventing discouraging continuous use of the emergency over-run mechanism, and this means preferably comprises a yleldable stop resisting complete depression of the ac This object is accomplished by so deas an approximate governing device.

Another major object of this invention is to devise a novel and eflicient governor for direct -connection with the throttle valve operating lever. Subordinate objects are to provide a device of this character which is simple in construction and easy to assemble, and to incorporate in such a device one or more adjustments which are effective and easily made.

Further specific or detailed objects reside in the provision of a novel pressure-responsive bellows and in the provision of novel spring constructions for resisting contracting movement of the bellows. I

The foregoing and further important objects of the present invention will clearly appear from a consideration of the following description and the appended claims, when taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a longitudinal sectional view through a preferred form of governor of the present invention connected between the accelerator pedal and thethrottle valve lever of an internal combustion engine. In this view the parts of the governor are shown corresponding to a partially depressed accelerator pedal position when the engine is under substantially no load.

Figure 2 is a longitudinal sectional view through the governing device of Figure 1, with the parts thereof shown in a position corresponding to substantially fully depressed accelerator pedal and heavily loaded engine.

A Figure 3 is an end view of the device of Figures 1 and 2 as seen when looking toward the lef hand end of Figure 2.

Figure dis a view showing the governing mechanism of Figure 1 in elevation and in association with mechanism for permitting momentary overrun of theengine, the latter mechanism being shown in vertical section.

Figure 5 is an enlarged sectional view of the details of the valve assembly of the over-run means of Figure 4. V

Figure 6 is a view similar to Figure 1 with the ,goveming unit thereof shown in elevation and associated with means for limiting surge of the governor toward open throttle positions.

Figure 7 represents a longitudinal sectional view through a modified form of governing mechanism, and mounting means therefor.

With continued reference to the drawings wherein like characters are employed to designate corresponding parts, and with particular reference for the moment to Figures 1 and 2, a governor assembly G is inserted as a unit between a pair of throttle rod sections l0 and I2 for tempering or modifying the manual control that the operator of a vehicle normally has upon the engine throttle valve through use ofthe accelerator pedal.

The throttle rod section III has its rear end pivoted at l3 to an accelerator lever M which forms part of a conventional manual control device pivoted at IE to the floor board l6 and operable through depression of a foot pedal I'I. Depres; sion of the pedal I1 is yieldingly resisted by a spring l8. For a purpose that will .later become apparent the pivot 13 is located relatively close to the accelerator pivot l5 instead of at the lower .end of the lever l4, which would receive one end of a conventional throttle rod if the engine were being operated in the normal ungoverned manner. a g

The forward end of the rod section 12. is pivoted'at It to the upper--end of a conventional throttle lever 20 which actuates a conventional carburetor butterfly valve 22 that is disposed within a conventional down draft conduit 23 leading into a'conventional internal combustionv engine manifold 24. The conduit 23 carries the usual throttle lever stops, including an idling adjustment 25. A flexible hose connection 26 extends between the interior of the manifold and the governing unit G for transmitting engine manifold pressures (vacuum) to the governing device.

The governing unit G comprises a cylindrical shell or container 21 having an end wall 28 through which the rod section i2 is freely slidable. By means of apertures 30 or the like this shell always contains air at atmospheric pressure. The other end of the container is closed by an annular wall 32 which centrally receives an externally threaded block 33 that has a close but sliding fit on the rod section Ill. The rod section in passes through this block into the container and at its inner end it is screw-threaded to receive an adjustable reactance member 34. As will be explained later the block 33 and the member 34 are designed to afford adjustments for varying the governed speed of the vehicle in such manner as to obtain accurate governing action under various conditions of operation.

The rod section In is pinned at 35 to a yoke or bracket 36 which in turn is securely fastened to the end of wall 32 of the container. tainer, therefore, is positively connected to the accelerator pedal and moves therewith throughout the permissible range of movement of the accelerator pedal. The other rod section I! floats with respect to the container and its control over the throttle valve lever is effected through spring action and vacuum conditions as follows:

A coil compression spring 31 which, when expanded or relaxed, is of approximately the length of the container is arranged axially with one end snapped into position in a recess on the inner side of the block 33. A smaller and shorter spring 33, likewise axially arranged, is secured at one end to the adjustable member 34. spring pack or assembly is surrounded and enclosed by a bellows 40 which is capable of elongation to substantially the full length of the container. One end of this bellows is secured and sealed against the container plate 32 by a ring 42, and the other end is fastened to the rim of a disc 43 which is secured by a pin 44 to the rear end of the throttle rod section l2.

The flexible hose 28 is placed in communication with the interior of the bellows assembly by a nipple 45 which extends through the container plate 32, and hence, when the engine is running there is always a. tendency for the bellows to contract longitudinally due to the fact that the engine produces a vacuum while the exterior of the bellows assembly is constantly under atmospheric air pressure. To prevent radial collapse of the bellows under these conditions a series of smooth rings 46 is provided, the rings being arranged in spaced relation along the length of the bellows. These sustaining rings permit use of thin and very flexible rubber materiaksuch for example as that sold on the market under the name Duprene".

The spring 31,- which may be called the tripping spring, is so calibrated that in its relaxed or most expanded position, it has sufllcient strength to resist engine manifold pressures at all speeds below the selected governed speed, but that at a speed equivalent to the selected governed speed The con- Thisv the engine manifold pressures are sumcient to compress the spring slightly as a result of contact between the disc t3 and the forward end of the spring. This slight compression of the spring causes the throttle lever to partially close and thereupon a lower engine manifold pressure is immediately attained, causing the bellows to still further contract. It is assumed, for example, that this contraction has started from a position corresponding to that shown in Figure 2, where the engine is under heavy load and the pressure within the bellows is therefore sumciently high that when augmented by the expanding action of the spring 3! it has placed the bellows in a position of substantially maximum longitudinal extension. It may be assumed that the accelerator pedal is at this time fully depressed so as to positively shove the container as far as it can go in the direction of the throttle and it maybe further assumed that the operator will keep the accelerator pedal in this depressed condition in order to assure travel of the vehicle at its maximum governed speed. Should the load now be picked up or lessened, the contracting action of the bellows just mentioned will take place because the engine will tend to run at higher speeds, thus to create ahigher vacuum in the intake manifold and therefore within the bellows.

Spring 31 is preferably wound in a variable pitch so that during the contracting action just discussed, a soft start will take place in compression of the spring and yet a rapid increase in the rate of build-up or resistance of the spring to contraction will be attained. Assuming that the contraction continues as a result of less and less load on the engine, the vacuum within the bellows will eventually overcome the increasing resistance of the large spring 87 and the disc 33' will eventually engage the forward end of the smaller spring 38. The last mentioned spring also is preferably made with a variable pitch, but it is stiffer than the other spring. Assuming these two springs to be properly designed, and set accurately by means yet to be described to maintain a predetermined governed speed, a point will be reached at which the difierential pressure, in and without the bellows, will be in equilibrium with the opposing forces setup by the two springs. Assuming further that the engine is .now under no load, this would be called the no-load governed position or speed, corresponding tothe position of the parts of the assembly as illustrated in Figure l wherein the large spring is considerably compressed and the small spring is slightly compressed.

In this position of parts (Figure l-no load) it may be assumed that the container has been manually pushed as far towards the right as possible, but with the internal mechanism properly set it is impossible for the operator to exceed the degree of throttle opening indicated in Figure l and given the legend Governed (no load). It is further necessary, of course, that the distance between the pivots l3 and IS on the ac-. celeratcr lever be so related to the governor and to the length of the throttle lever that the spring pack or assembly, which is mounted on the container, cannot be shoved too far to the right. It is for this reason that the pivot I3 is located at a high point instead of at the lower end of the lever where the throttle rod is conventionally con-. nected.

Applications of load will cause the bellows to expand until eventually the full load position of the bellows is obtained as illustrated in Figure 2.

This corresponds to the throttle lever position designated at Wide open in Figure 1. The range, through which the engine is governed automatically by varying load application, is

designated in Figure 1 with reference to throttle position by the angle marked Governed range (varying load). It is, of course, necessary that the accelerator pedal be completely depressed to obtain a wide-open throttle position under heavy load, and it is, of course, also necessary that the pedal be sumciently depressed in other positions within the governed range to produce a throttle position corresponding to governed speed if maximum vehicle speed is desired.

Assuming now that it is desired to return the engine from accelerated condition to idling or closed throttle position, the accelerator is first released whereupon the spring l8 swings the lever id to pull the rod section i0, and with it the container 21 toward the left in Figure 1. As the springs 31 and 38 are carried bodily with the container, this movement reduces the spring pressure on the disc 413 with the result that atmospheric pressure externally of the latter causes contraction of the bellows and movement of the rod section l2 towards the left. This movement of the rod section it is automatically continued until an equilibrium point is reached within the governing device corresponding substantially to the throttle lever position marked Idling in Figure 1. Preferably, this equilibrium point will not quite be reached when the throttle lever makes contact with the idling adjustment 25.

It should be observed that in neither direction of movement of the governor is there any unusual resistance set up against either downward or return movement of" the accelerator pedal. The governing mechanism has an automatic follow-up action as above described, so that relatively small force may be applied to the pedal H to accelerate the vehicle, and the usual spring I8 is sufficiently strong to return the pedal when said force is removed. It should further be observed that when the accelerator pedal is depressed to start the vehicle, or when the pedal has already been depressed and the load on the engine increases, the governing device operates automatically to cause a surge or immediate forward movement of the rod section l2 with a corresponding immediate increased throttle opening. This characteristic prevents stalling of the engine if an attempt is made to start the vehicle.

-being adjusted for a lower speed, to become weaker, for the forces tending to close the governor are becoming lighter in the tripping or starting position. On the other hand, it requires the final or abutment spring 38, when being adjusted for a lower speed, to become stronger, for the pressures after closing are lower and the bellows would develop considerably more power when the engine is set for, say, a governed speed of 1500 R. P. M., than it would where set at, say,

2500 R. P. M. The opposite holds true when ad-- justing the springs for higher governed speed, for

efiecting the rotation. A pin 48, parallel to the axis of the governing unit, is secured at one end to the adjustment member 34, as previously described, and the other end of this pin slidably projects into a hole 53 in the front of the block 33, without, however, filling the hole, It follows that when the block 33 is adjustably rotated, the member 34 will be simultaneously rotated by the pin connection and that if the two adjustment elements 33 and 34 have threads of different pitch they will travel axially at different speeds during the adjustment, as permitted by the sliding connection between the pin 48 and block 33.

Actually. the threads on the inner end of the rod section in are opposite or reverse to those on the member 33, and therefore when the latter is rotated for purpose of adjustment it travels axially in one direction while the member 34 travels axially in the opposite direction. Therefore, assuming a right hand thread to be on member 33 and a left hand thread to be on the member 34, it follows that when the block 33 is screwed in it will move to the right and simultaneously cause the member 34 to move to the left. Further, by varying the pitch of thread on members 33 and 34 with respect to each other, any definite amount of relative movement required may be obtained. For example, if a sixteen pitch thread is used on member 33 and a thirty-two pitch thread used on member 34, one full revolution of member 33 in a clockwise direction will move said member inch to the right and at the same time move the member 34 inch to the left.

Selection of proper thread pitches, and proper spring strengths and variable pitches will be made to suit the particular type of engine and vehicle upon which the governor is to be mounted. Subsequently, after installation, proper adjustment by rotation of the block 33 may be made to preselect a particular governed speed within a given range of possible governed speeds or to make corrections toward maintenance of a given governed speed throughout the life of the particular engine, in which the vacuum conditions may vary as a result of prolonged use and wear. Any suitable sealing or locking means may be providedto prevent tampering or unauthorized adjustment of the governing unit.

As previously stated, governors are frequently criticized because they prevent full acceleration of the vehicle,that is, acceleration beyond the governed speed temporarily for the purpose of avoiding accidents. lustrated, in association with the assembly of Figure 1 an emergency full-flow or over-run device. The flexible conduit 26 of Figure 1 has been out between its ends to form two sections 26a and 26b, and the two severed ends thus formed have been inserted in sockets provided in a valve block or housing 52, as best seen in the large view of Figure 5. The housing 52 has a vertical cylindrical chamber 53 which is in communication with the severed ends of the conduit by means of a pair of passages 54. A cylindrical valve 55 is In Figure 4 there is 11- slidably mounted in the chamber 53 andis provided with a peripheral groove 56 which, in the position illustrated in Figure 5, establishes coinmunication between the conduit sections 26a and 2617 by way of passages 54. 'Normally, atmospheric pressure exists above the valve, and a spring 51 disposed below the valve has suflicient strength to maintain the valve at this time in the position illustrated in Figure 5 so that normally the bellows of the governor assembly is in communication with the engine manifold.

A second peripheral groove 58 is provided on the valve above the groove 56 and this second groove is in communication, by way of a cross passage 66 with an axial hole 62 which is in communication with the atmosphere by way of the bottom of the valve chamber and a port 63. Therefore, should the valve be pushed downwardly to bring the groove 58 into registry with the passages 54, communication between the governor and the engine manifold would be disrupted and the interior of the governor bellows placed under atmospheric pressure. 'Under such a condition the internal mechanism of the governor would be in the position illustrated in Figure 2, and therefore, should the driver completely depress the accelerator pedal the throttle would be placed in wide open position. The means for pushing the valve downwardly to obtain this condition is as follows:

A bracket 64, secured to the engine or to any part of the vehicle provides a pivotal support for the center of a bellcrank 65, one arm of which is connected to the throttle rod section ID by means of a link 66 and a clamp Bl, and the other arm of which is positioned above a compression spring 63 in close association or connection therewith. The spring 68 is directly above the valve 55 and in the space between these members there is interposed a bellows 10. The lower end of the bellows 10 is fastened in sealing engagement with the valve housing 52 and the upper end is movable vertically. Normally the bellows is under atmospheric pressure by way of a fitting 12 having a restricted aperture extending between the interior of the bellows and the atmosphere.

With the parts in the position illustrated in Figure 4, let it be assumed that an emergency arises and that the operator jams the accelerator pedal all the way down to the floor board. This causes a sudden clockwise oscillation of the bell crank 65 and a quick transmission of movement to the bellows 10 by way of spring 68. The application of this downward cushioned force to the upper end of the bellows causesthe latter to shorten quickly to compress the air contained therein and, in so doing, to urge the valve 55 downwardly until it seats against the bottom of the chamber 53, thus rendering the governing device inoperative and giving the operator com; plete control of the vehicle in the manner previously explained. The valve housing is supported by the bracket 64 to hold it against movement during this operation. 1

The length of time during which the bellows of thegovernor is in communication with the at-L mosphere through the valve 55 will depend upon the vertical width of the annular groove 53 and the size of the aperture of the fitting 12, each of which may be pre-selected during manufacture and the latter of which may be varied after installation by any suitable adjustment. Aftera few seconds of time the spring 51 will return the valve 55 to its normal illustrated position, due to lowering of pressure within the bellows 10 .as

. celerator movement.

brought about either by removing the force applied to the accelerator pedal or by escape of air from the bellows into the atmosphere through slow leak device 12 or by both expedients.

To prevent the vehicle operator from taking advantage of the mechanism just described and cheating the governor by tramping rapidly on the accelerator pedal, a relatively heavy coil spring 73 is provided on the floor board below the accelerator pedal. A slow depression of the accelerator pedal is insufficient to render the governor inoperative, as the pressures thus created within the bellows 10 are dissipated through the slow leak device 72 at a high enough rate to prevent sufficient pressure build-up to force the valve 55 downwardly. The relatively heavy spring 73 is of such length that it sets up resistance over approximately the last half of the ac- Normally, therefore, its presence is unobjectionable and in emergencies it could offer no objection to a driver who under the impetus of danger should suddenly jam the throttle wide open, but its presence would present a very disagreeable task to the driver who attempted pumping" the car along at speeds in excess of the governed speed.

The bumper spring 13 may be used by itself as an approximate governing device having the same safety or emergency feature ascribed to it above. For example, in transporting new vehicles for purposes of delivery under their own power, such springs may be used below the accel-,

erator pedals to normally discourage the operators from driving the vehicles at excessive speeds. The spring has suflicient strength to make it a diiiicult and disagreeable task to hold the accelerator pedal down to the floor board constantly under a steady pressure, but it is sufiiciently yieldable to permit depression of the accelerator pedal under a quick blow delivered by the foot of the operator.

It was pointed out in connection with Figures 1 and 2 that the governing device of this invention automatically causes the throttle to surge slightly toward open position upon increase of load (in the engine, this sudden surge having the advantage of preventing stalling of the engine. In the hands of an unskilled ,orcareless driver this surge may prove undesirable, particularly when starting and accelerating the vehicle from a standing stop. For, should the accelerator be depressed too far or too suddenly, the resulting surge from the governor would tend to jerk the vehicle into motion and thereafter accelerate it too rapidly. For the purpose of preventing this undesirable condition from arising while maintaining the advantages of the surge effect, I have devised the following auxiliary mechanism.

With reference to Figure 6 of the drawings, a link or rod 15 is connected between the throttle and the lower end of the accelerator lever H. The forward end of this rod is directly pivoted at Hi to the upper end of the throttle lever 20 and the-rearward end is provided with an elongated slot 16 which receives a pin 11 carried at the lower end of accelerator lever M. The parts are shown in their relationship to one another when the engine is in idling position, at which time the accelerator pedal is completely elevated, and in this position it will be noted that a small clearance at 18 of say, /8 to A; of an inch, exists between pin 11 and the left hand end of the slot 16. Let it be assumed that the vehicle is standing with the parts in the illustrated idling position and that the operator lets the clutch in while simultaneously making a move toward feeding gas to the engine. If the operator inadvertently fails to depress the accelerator pedal or depresses it insufiiciently to pick up the load from a standing start, the load will tend to stall the engine,

but in so doing will increase the pressure in the -manifold and cause the governing device to tend to surge toward the right to increase the throttle opening. The clearance provided at 18 is suflicient to permit a large enough surge to prevent the engine from stalling. On the other hand, when this clearance 18 has been taken up, no additional automatic throttle opening is permitted, and therefore the vehicle cannot accelerate more rapidly than intended. Upon further depression of the accelerator pedal, the rod 15 is permitted to move forwardly with the throttle rod section it! and the throttle lever 20. The slot I6 in the rod '75 isof sufiicient length to permit complete depression of the accelerator pedal.

With the surge-limiting arrangement just described, should the accelerator pedal be depressed suddenly or a little too far for the intended vehicle acceleration, either during starting or after starting the vehicle, a small surge will be permitted but this surge can never cause the throttle to run ahead of the accelerator more than an amount corresponding to the clearance 18. The throttle can, of course, go to wide open position when the load in sumcient to prevent the vehicle from exceeding governed speed, because the lower end ofthe accelerator lever M has an arc of full travel corresponding to the arc of full travel of the throttle lever from idling to wide open position. However, complete depression of the accelerator pedal is alone insumcient to force the throttle to wide open position because the pivot point 13 is so high that the governor container and spring assembly can only be positively moved a relatively shortv predetermined distance toward the right by depression of the accelerator pedal.

The auxiliary devices of Figures i and 6 may, of course, be used together as well as individually in association with the mechanism of Figures 1 and 2.

In Figure 7 there is shown a modified form of governor wherein the container, comprising a shell 21a and end walls 28a and 32a, is so mounted a that it is substantially held against axial movement relative to the throttle rod sections Illa and Ho. The forward end wall 28a of the container is pivotally connected at 88 to a link 82 which is supported on or adjacent the throttle valve pivot which receives the throttle valve lever 28. Support for the container is completed by the throttle rod section Illa which, however, in this instance is not connected to the container but is slidable longitudinally thereof. The rod section Illa is connected to the lower end of an accelerator lever in conventional manner instead of at a higher point as in Figure 1. The rear end of rod section |2a extends through the bellows disc 43, to which it is secured as in Figure 2, and is pivotally connected at 83 to one end 'of a link 84. The link 84 has an elongated slot 85 which freely receives a pin 86 that extends through a forked portion 81 of the rod section IBa.

Springs 31a and 38a are provided as in the form of Figure 2, and in this instance they are mounted at their rear ends on a pair of adjustable members 88 and 92. Member 88 is preferably shaped as a block and has an externally threaded end 89 adjustably screwed into a portion of a yoke or bracket 36a that may be termed the base member of the device and is secured to wall 32a. Member 88 also has a longitudinal slot 90 into which freely projects a radial pin 93 carried by the other adjustable member 92.

The members 88 and 92 therefore rotate in unison and as they have external threads of difierent and reverse pitches, they will upon adjustment have the same effect upon the springs 31a and 38a as was set forth in connection with the adjustable members 33 and 34 of Figure 2.

In operation of the modified form of Figure 7, positive manual movement of the throttle lever away from idling position is obtained by depressing the accelerator considerably to engage the pin 86 with the right hand end of the slot 85. A forward automatic surge then follows to carry the throttle towards governed position. The bellows and associated parts can get to the relative positions illustrated in Figure 7 only when the throttle is fully depressed and the engine is under load. There will, of course, be a governed range for this form just as for that of Figures 1 and 2, with the throttle position depending upon the amount of load on the engine and the maximum governed speed setting. Here, however, due to the fact that the container and spring pack does not move forwardly with the accelerator and rod Illa, the spring 31a is made slightly longer than spring 31 of Figures 1 and 2, in order to cause or permit the throttle to go to wide open position under heavy load. The slot 85 is of a length corresponding substantially to the range of throttle movement from a no-load governed position tofull-load governed position. To restore the throttle to idling position, or to a position below the governed no-load position, the accelerator pedal is permitted to rise and withdraw the rod section Illa fromthe governor container to thus bring the pin 86 into contact with the left hand end of slot 85, which in turn moves 1 the rod section l2a rearwardly.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive,

. the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In combination with an internal combustion engine having a throttle valve and a manually operable accelerating device and a governor responsive to engine vacuum to limit the speed of the engine to a predetermined maximum by control over the throttle valve, an emergency overrun device for rendering said governor inoperative and affording complete manual control of the throttle valve to its wide open position by said accelerating device.

2. In combination with an internal combustion engine having an intake manifold controlled by a throttle valve, a governor comprising a base memher, an adjustable block mounted on said member for movement relative thereto, a pressure responsive member including a movable element interposed between said base member and said throttle valve, and connected to said intake manifold, manually operable accelerating means including a rod slidably mounted in said adjustable block.

and a lost motion connection between said rod;

and said movable element.

3. In combination with an internal combustion engine having an intake manifold controlled by a throttle valve, a governor comprising a base member, an adjustable block mounted on said member for movement relative thereto, a pressure responsive member including a movable element interposed between said base member and said throttle valve, and connected to said intake manifold, means for mounting said base member ally operable mechanism including a rod having means for moving said throttle valve from open toward closed position and permitting limited opening movement-of said throttle valve.

4'. In combination with a governor for an internal combustion engine, means to operate said governor in accordance with a predetermined characteristic of the fuel fiowto said engine to limit the engine to a predetermined maximum speed, manually operated means for controlling said engine, and means connected to said latter means for rendering said governor operating means temporarily inoperative to permit engine speeds in excess of the governing speed for a predetermined period of time.

5. In combination with a governor for an internal combustion engine, means to operate said governor in accordance with the vacuum in the intake manifold of said engine to limit the engine to a predetermined maximum speed, manually operated means for controlling said engine, and means connected to said latter means for temporarily subjecting said governor operating means to a pressure in excess of the engine vacuum to permit engine speeds in excess of the governed speed for a predetermined period of time.

6. In combination with the throttle operating mechanism of an internal combustion engine, resilient means to oppose movement of said mechanism in a direction to open the throttle of said engine through a range corresponding to the normal speed of operation of said engine under average conditions with a normal resistance, and to oppose movement of said mechanism in a direction to further open the throttle of said engine through a range corresponding to excessively high speeds of said engine with a relatively high resistance to discourage continued operation of said engine at such high speeds.

7. In combination with the throttle operating mechanism of an internal combustion engine, resilient means to oppose movement of said mechanism in a direction to open the throttle of said engine through a range corresponding to the normal speed of operation of said engine under average conditions, and additional resilient means arranged to supplement the action of said first means and furnish a relatively high resistance when said mechanism is moved in a direction to further open the throttle of said engine through in fixed relation to said throttle valve, and manua range corresponding to relatively high speeds secure said fixed element relative to the throttle pivot. 9. In combination with a governor for the throttle of an internal combustion engine, an accelerator rod connected to said throttle for manual operation of the same, said rod being connected to the accelerator in a manner to move in a definite proportion therewith, means for varying the length of said rod in accordance with the vacuum in said engine, and means including a lost motion connection connected to said throttle and to said accelerator at a point to move a greater distance than said rod for a corresponding movement of said accelerator.

10. In combination with an internal combustion engine, a throttle, a manually operable accelerator for said throttle, a throttle rod and governor assembly between said throttle and said accelerator, said assembly comprising a vacuum responsive device connected to the vacuum manifold of said engine and operative to change the length of said. throttle rod in accordance with changes in the vacuum in the manifold of said engine, and resilient means to oppose changes in the length of said throttle rod caused by increases in said engine vacuum, said resilient means being effective upon said vacuum responsive device throughout its entire range of movement whereby a balance is maintained in all positions, and the length of said throttle rod is immediately changed to open said throttle upon any decrease in the engine manifold vacuum effective upon said vacuum responsive device.

11. In the combination defined in claim 10, means operative by said accelerator to limit the degree of surge of said throttle toward open position.

WILLIAM E. LEIBING.

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