US3400697A

US3400697A - Speed control device

Info

Publication number: US3400697A
Application number: US420558A
Authority: US
Inventors: Cupit Carl; Christopher J Oliva; Jr Charles Broad; Ralph A Gritchen
Original assignee: International Harverster Corp
Current assignee: Navistar Inc
Priority date: 1964-12-23
Filing date: 1964-12-23
Publication date: 1968-09-10
Anticipated expiration: 1985-09-10

Description

United States Patent f 3,400,697 SPEED CONTROL DEVICE Carl Cupit, Plainiield, Christopher J. Oliva, Chicago,

Charles Broad, Jr., Westchester, and Ralph A. Gritehen,

Park Forest, 11]., assignors to International Harvester Company, a corporation of Delaware Filed Dec. 23, 1964, Ser. No. 420,558 6 Claims. (Cl. 123-97) This invention relates to engine speed control devices. More particularly, the invention relates to speed control devices of a centrifugal type used to vary the quantity of fuel and air supplied to an engine in response to changes in engine load or in response to changes in position of an associated speed control lever.

One problem associated with conventional centrifugal speed control devices relates to providing sensitive controls that are responsive to small speed changes at relatively low engine speeds.

Thus, an object of this invention is to provide an improved speed control device.

Another object is to provide a centrifugal speed control device that is responsive to small changes in engine speed from a selected engine speed within a low to intermediate speed range.

A further object of the invention is to provide a speed control device of the centrifugal type having two springs opposing centrifugal action of flyweights including a weaker spring that senses and responds to small changes in engine speed at low and intermediate engine speeds.

Still another object of the invention is to provide a centrifugal engine speed control device having auxiliary spring means that is responsive to small changes in engine speed at low and intermediate speeds as well as a primary spring that is operative for regulating engine speeds at intermediate to high operating speeds to enable accurate speed selection throughout tht range of low to high engine speeds.

These and other objects of the invention will become apparent from the following description when considered in conjunction with the accompanying drawing, wherein:

FIG. 1 is a somewhat diagrammatic view in section of a speed control device constructed in accordance with the principles of the present invention;

FIG. 2 is a sectional view of a portion of the device shown in FIG. 1 with a speed selection lever shown in a different position.

Referring to the drawing, there is shown a speed control device or governor 10 for an associated engine, not shown, including an engine-driven governor shaft 12 secured within a governor pinion assembly 14 and having a governor weight carrier 16 secured thereto serving as a pivotal support for a pair of governor weights or flyweights 18 which rotate with the shaft.

The driven shaft 12 supports a thrust sleeve assembly 20 including a sleeve 22 and ball :bearing 23 for rotation as well as axial sliding movement on the shaft 12 toward and away from the pinion assembly 14.

The fiyweights 18 each have an inwardly extending finger 24 extending inwardly toward a center of rotation 26 of the shaft 12 and adapted to engage one end 28 of the sleeve adjacent the pinion assembly 14. During operation of the engine, the flyweights 18 tend to swing pivotally outwardly with respect to the shaft center of rotation 26, as indicated by the arrows. As the flyweights swing outwardly, the fingers 24 move pivotally to the right, as viewed in the drawing, urging the sleeve 22 to the right.

The speed control device 10 includes a housing 30 and speed change lever means 32 including a forked arm 33 positioned against the ball "bearing 23 biasing it to the left and a body portion 35 pivotally secured 3,400,697 Patented Sept. 10, 1968 "ice to the housing and connected to conventional fuel throttling mechanism, not shown, to vary the quantity of fuel supplied to the engine. The speed control device 10 also includes a speed selection lever 34 pivotally mounted on the housing to selectively change the speed of the engine and a leaf type cantilevered spring assembly 36 secured to the speed selection lever 34 for move ment with the speed selection lever 34 upwardly and downwardly as viewed in the drawings about a center of rotation 38. The spring assembly 36 includes a mounting base 37 which is secured to lever 34 and a leaf spring 39 which is cantilevered outwardly from the mounting base 37 and which has a far end 40 having an opening, not shown, therein for connective receipt of a looped end 42 of a governor coil spring 44 connected at its other end 46 to the speed change lever 32 and urging the speed lever 32 to move in a counterclockwise direction about a center of rotation 47 toward an increased :fuel position to increase the speed of the associated engine.

The leaf spring 39 is a relatively softer or weaker spring in comparison to the relatively stronger coil spring 44 and hence spring 39 is more sensitive to small changes in position of the speed change lever 32. Accordingly, spring 39 is adapted to regulate low and intermediate engine speeds below a predetermined speed; and the relatively stronger coil spring 44 is adapted to regulate the higher engine speeds above the predetermined speed.

The speed selection lever 34 has an upper surface 48 which is adapted to engage or support a lower surface 50 of the leaf spring when speed selection lever 34 is moved to a predetermined upper position for higher engine speeds as illustrated in FIG. 2.

Having now described the invention, its operation should be clear. The engine speed regulation device 10 incorporates engine actuated centrifugal goveinor weights 18 which act on speed change lever 32 to throttle the amount of fuel supplied to the engine. With increases in rotational shaft speed, the governor weights force thrust sleeve 22 to the right, as viewed in the drawing, against speed change lever means 32 to rotate it clockwise, decreasing fuel supplied to the engine. Resilient means comprising a first governor spring 44 opposes the action of the flyweights by urging the speed change lever 32 counterclockwise toward a full or relatively increased fuel position. Second resilient means comprising a relatively weaker governor spring connected to lever 34 and adapted to rotate with it, cooperates with the first spring to assist it in opposing the action of the flyweights in rotating the speed change lever 32 clockwise.

To increase engine speed, the speed selection lever 34 is raised, moving the two springs upwardly and rotating speed change lever means 32 counterclockwise in fuel increasing direction to urge the thrust sleeve 22 to the left tending to collapse the governor weights. The increased fuel supplied to the engine tends to increase the speed of the rotating shaft 12 and the governor weights 18 I0- tate outwardly from the shaft to a predetermined spring balancing point at which point the thrust of the governor fingers to the right against the sleeve 22 is equal to the force of the springs urging the sleeve to the left; at this point the speed of the engine is stabilized, as is well understood.

The one spring is relatively weaker than the other spring and is consequently more sensitive to and more responsive to small speed changes in the relatively lower speed ranges; hence the softer of the two springs regulates the speed change lever at low and medium range speeds. As engine speed is increased by raising the speed selection lever 34, spring tension increases and both springs operate to resist the action of the flyweights in moving the speed change lever toward a decreased fuel position. At a predetermined raised positon of the speed selection lever 34 to achieve a predetermined speed, means are provided for rendering the weaker spring ineffective, that is, the speed selection lever 34 moves into a spring supporting position and the reactive effect of the weaker spring is completely expended. Thus, the weaker of the two springs is rendered ineffective above a predetermined relatively higher engine speed; and control of speeds higher than this predetermined speed are governed by the stronger of the two springs.

Accordingly, the unique spring tensioning mechanism of the present invention achieves a centrifugal speed control device which is sensitive to and responsive to small speed changes throughout a wide speed range from low to high speeds.

Since modifications of the details of the structure as illustrated are contemplated, the invention should be limited only by the scope of the appended claims. The invention is claimed as follows:

1. In a centrifugal governor including a housing, a fuel control member, engine actuated centrifugal flyweights acting on said member to move it toward a lower fuel position, a first governor spring o posing the action of the flyweights said spring having first and second ends, said first end being connected with said fuel control member to urge it toward a fuller fuel position, said second end being connected to said housing, the improvement comprising: a second governor spring interconnected directly to said second end of said first governor spring and said housing and adapted to cooperate with said first governor spring in opposing the action of the flyweights, said second governor spring being relatively weaker than said first governor spring and being adapted to oppose the action of said flyweights; and stop means to render said second governor spring ineffective when said member approaches a predetermined position corresponding to a predetermined engine speed.

2. In a device for controlling the delivery of fuel to an engine to be controlled and being sensitive to the speed of said engine and having:

a governor shaft rotating at an engine related speed;

a thrust sleeve positioned on said shaft and rotating therewith, said thrust sleeve being adapted for sliding movement axially on said shaft;

a fuel control member adapted to be engaged by said sleeve when it is moved axially in one direction n said shaft;

governor Weights pivotally connected to said rotating shaft, each of said Weights having a radially 1nwardly extending finger adapted to engage said sleeve, said weights being adapted to swing radially outwardly with increases in the speed of said rotating shaft, said fingers being adapted to move said sleeve axially away from said shaft against said fuel control member to move it toward a position to decrease the fuel supplied to said engine;

resilient spring means opposing the action of the flyweights and connected with said fuel control member to increase the fuel supply to said engine;

and speed selection means to vary the effective force of said resilient spring means in opposing the action of the flyweights to vary the engine speed, the improvement comprising:

second resilient spring means having first and second ends and being connected at its first end to said speed selection lever and being connected at its second end to said first resilient spring means, said second resilient spring means being adapted for movement upwardly and downwardly with said speed selection lever to vary the effective spring force opposing the outwardly swinging action of the flyweights, said second resilient means being relatively weaker than said first resilient means, said speed selection means having spring rest means thereon adapted to support said second resilient spring means and render it ineffective when said speed selection means is moved to a predetermined position corresponding to a predetermined intermediate engine speed.

3. In a device for controlling the delivery of fuel to an engine and being sensitive to the speed of the engine, said device having:

a governor shaft rotating at an engine related speed;

a thrust sleeve supported on said shaft and rotating therewith, said thrust sleeve being adapted for sliding movement axially on said shaft;

a fuel control member adapted to be engaged by said sleeve when it is moved axially in one direction;

governor weights pivotally secured to said rotating shaft, each of said Weights having a radially inwardly extending finger adapted to engage said sleeve, said weights being adapted to swing radially outwardly with increases in the speed of said rotating shaft, said fingers being adapted to move said sleeve in said one direction against said fuel control member to move it into a position to decrease the fuel supplied to said engine;

a coil spring opposing the action of the flyweights, said coil spring having two ends and being connected at one end to said fuel control member to increase the fuel supplied to said engine;

and rotatable speed selection means to vary the effective force of said coil spring in opposing the action of the flyweights, the improvement comprising:

a leaf spring secured at its one end to said speed selection means in cantilevered fashion for rotation with said speed selection means and connected at its other end to a second end of said coil spring, said leaf spring being adapted for rotation with said speed selection means to vary the spring force opposing the outwardly swinging action of the flyweights, said leaf spring being relatively weaker than said coil spring, said speed selection means having spring rest means thereon adapted to support said leaf spring between the ends of said spring and render it ineffective when said speed selection means is moved to a predetermined position corresponding to a predetermined intermediate engine speed.

4. In a device for controlling the delivery of fuel to an engine including a fuel control member, engine actuated centrifugal flyweights acting on said member to move it toward a position to decrease the amount of fuel supplied to said engine, a first governor spring opposing the action of the flyweights and connected to said member to urge it to increase the amount of fuel supplied to said engine, the improvement comprising: a second governor spring connected to said first governor spring and cooperating therewith, said second governor spring being a relatively weaker spring than said first governor spring; and means to render said second governor spring ineffective at a preselected engine speed, whereby engine speeds below a predetermined engine speed are regulated by said second governor spring and whereby engine speeds above a predetermined speed are governed by said first governor spring.

'5. In a selectively variable constant speed governor for an engine including a shaft rotating at an enginerelated speed, fuel control means to control the fuel delivered to the engine, governor weights pivotally connected to said shaft and adapted to engage said fuel control means to urge said fuel control means to decrease the amount of fuel supplied to said engine as the speed of said engine shaft increases, first spring means connected to said fuel control means acting on said fuel control means to increase the amount of fuel supplied to said engine, speed selection means connected to said spring means and adapted for movement to vary the tensile force of said spring means acting in opposition to a centrifugal action of said weights, the improvement comprising: second spring means connected to said first spring means and cooperating therewith, said second spring means being relatively weaker than said first spring means and adapted to oppose the action of said governor weights at relatively lower engine speeds, said second spring means being of the leaf type and being secured in cantilevered position to said speed selection means for movement therewith, said speed selection means including means to render said second spring means ineffective when said speed selection means is moved into a predetermined position to achieve a predetermined engine speed, whereby said second spring means governs the speed of said engine at relatively lower engine speeds and said first spring means governs the speed of said engine at relatively higher engine speeds.

6. In an engine governor including a fuel control member, engine actuated centrifugal fiyweights acting on said member to move it toward a position to decrease the amount of fuel supplied to said engine, a coil spring connected to said fuel control member opposing the action of said flyweights and urging said fuel control member to a position to increase the amount of fuel supplied to said engine, and a speed selection lever to vary the position of said fuel control member, the improvement comprising: a leaf spring having two ends and being secured at a first end to said speed selection lever for movement therewith with a second end cantilevered therefrom, said leaf spring being connected at its second end to said coil spring, said speed selection lever being adapted to render said leaf spring ineffective when said speed selection lever is moved to a position corresponding to a predetermined intermediate fuel position of said fuel control member, said leaf spring being relatively weaker than said coil spring whereby said leaf spring acts to govern the speed of said engine at relatively lower engine speeds and said coil spring acts to govern the speed of said engine at relatively higher engine speeds.

References Cited UNITED STATES PATENTS 1,325,478 12/1919 Krebs 73-546 2,507,689 5/1950 Buck 73-537 RALPH D. BLAKESLEE, Primary Examiner.

Claims

1. IN A CENTRIFUGAL GOVERNOR INCLUDING A HOUSING, A FUEL CONTROL MEMBER, ENGINE ACTUATED CENTRIFUGAL FLYWEIGHTS ACTING ON SAID MEMBER TO MOVE IT TOWARD A LOWER FUEL POSITION, A FIRST GOVERNOR SPRING OPPOSING THE ACTION OF THE FLYWEIGHTS SAID SPRING HAVING FIRST AND SECOND ENDS, SAID FIRST END BEING CONNECTED WITH SAID FUEL CONTROL MEMBER TO URGE IT TOWARD A FULLER FUEL POSITION, SAID SECOND END BEING CONNECTED TO SAID HOUSING, THE IMPROVEMENT COMPRISING: A SECOND GOVERNOR SPRING INTERCONNECTED DIRECTLY TO SAID SECOND END OF SAID FIRST GOVERNOR SPRING AND SAID HOUSING AND ADAPTED TO COOPERATE WITH SAID FIRST GOVERNOR SPRING IN OPPOSING THE ACTION OF THE FLYWEIGHTS, SAID SECOND GOVERNOR SPRING BEING RELATIVELY WEAKER THAN SAID FIRST GOVERNOR SPRING AND BEING ADAPTED TO OPPOSE THE ACTION OF SAID FLYWEIGHTS; AND STOP MEANS TO RENDER SAID SECOND GOVERNOR SPRING INEFFECTIVE WHEN SAID MEMBER APPROACHES A PREDETERMINED POSITION CORRESPONDING TO A PREDETERMINED ENGINE SPEED.