US3133531A - Governor - Google Patents

Description

May 19, 1964 T, F. CRAMER 3,133,

' GOVERNOR Filed Sept. 19, 1960 2 Sheets-Sheet l BY THOMAS F. CRAMER WMad-ub TORNEYS T. F. CRAMER May 19, 1964 GOVERNOR 2 Sheets-Sheet 2 Filed Sept. 19, 1960 2 VEN TUE I) l2 MAN/FOLD sovzelvoe INVENTOR. THOMAS F CRAMER ATTORNEYS United States Patent O This invention relates to governors for internal combustion engines and more particularly to a governor which is responsive to the speed of the engine or to the road speed of the vehicle and to the vacuum pressures of the engine. The invention further relates to an engine governor mechanism.

In the past, governing systems used a cut-off point, by means of restrictionsin the vacuum cross bleed pickups, to aid in controlling or governing the engine. These systems performed adequately in most cases, but it was found that in some cases, particularly with carburetors having large bores, there was not enough vacuum to obtain the proper or desired cut-01f.

This invention overcomes the problem by providing means for restricting the bleeding of manifoldvacuum into the venturi vacuum line until after the cut-01f point is reached and a predetermined manifold vacuum is obtained. K

Accordingly, it is an object of the present invention to provide a governing system for an internal combustion engine, said system including a governor responsive tothe speed of the engine or to the road speed of the vehicle 'and means for restricting the bleeding of manifold vacuum into the venturi vacuum line. after the cut-oif point is reached and a predetermined manifold vacuum is obtained.

Another object. of the present invention is to provide a governing system for an internal combustion engine, said systemincluding a governor responsive to the speed of the engine or tothe road speed of the .vehicle, said governor including afluid pressure operated motor, and valve means associated with the passagerneans connecting the venturi-and manifoldto the fluid motor and operative upon the attainment of a predetermined speed and a predetermined manifold vacuum to res trict the transmission of manifold vacuum to the motor.

Still another object of the present invention-isjto provide a governing system for an internal combustion engine hav- 'ing a throttle, said system including a governor responsive to the speed of the engine or to the road speed of the vehicle, said governor including a fluid pressure operated motor, and valve means associated with the passage means connecting the venturi and manifold to the fluid motor and operative upon the attainment of'a predetermined speed and a predetermined manifold vacuum to restrict the transmission of manifold vacuum to the motor, said throttle 'means being moved in a closing direction by ,the fluid jmotorwhich is actuated by venturi vacuum.

ings, illustrating apreferred embodiment of the invention, wherein:

FIGURE 1 is an elevational view in partial cross section showing the invention as it may be used in a governing system, and a diagrammatic illustration showing the entire governing system.

FIGURE 2 is an elevational view in partial cross section showing a modified form of valve incorporated in the governing system. v I 7 Referring now to the drawings in greater detail, FIG.- URE 1 illustrates a carburetor-.10 which is mounted on a manifold 12 of an internal combustion engine. The carburetor 10 includes a body 14 having an air inlet passage 16 and a fuel nozzle 18 discharging into the induction passage 20. The fuel nozzle 18 is located in the venturi 22. A throttle plate 24 is provided in the passage below the venturi 22 and is held therein by a rotatableithrottle shaft 26 which is appropriately carried in the body 14.

A vacuum operated device or motor 30, commonly referred to as a governor diaphragm assembly, is mounted on the boss 32 extending from the carbutetor body 14. The assembly 30includes a body 36 formed to provide recesses, or chambers 38 and 40. The recess 40 is covered by means of a flexible diaphragm 42 which is secured to the body 36 by means of a cover member 44 formed to provide an airtight chamber 46. The flexible diaphragm 42 forms a wall of the chamber 46. The cover member 44 may be secured to the body 36'by any suitable means such as screws 47.

As shown by FIGURE 1, the diaphragm 42 has secured to the center thereof, in'a conventional manner, a rod 48 passing through a passage 50 in the body 36. The rod 48 has a laterally extending end 52 pivotally secured to the lever 54 which is rigidly secured to the end of the primary throttle shaft 26 which extends into the chamber :38. An adjustable pin 60, carried by the body 36, extends into'the recess 38. A fixed pin 64 is secured to the lever 54. A tension spring 58 is attached betweenthe adjustable pin 60 and the fixed pin 64 and tends to hold the throttle plate 24 in an open position. An atmospherically vented cover plate 66 may be securedby screws 68 to the body'36, thereby protecting the mechanism within the recess or chamber 38.

Fixed to the otherend of shaft 26 is a plate or lever '70 which abuts against the manual throttle control rod 72. A spring 74 has one end fixed to plate 70 and the other end fixed to any means, such as a pin 76, which is "connected to the carburetor body 14 so as to allow the spring 74 to close the throttle plate 24. The venturi pick- 'up has a restriction' 82'therein and connects with the manifold pickup 84 in passage 86, by means of passage 88, chamber and passage 92 which has restriction 94 therein. A governor cut-ofl valve 129 is provided or interposed in betweenpassagesSS and92 'as will be subsequently described.

1 Located at any desired position on the engine is a governor valve assembly 93 comprising a stationary for rotation with theshaft 96 is a'laterally extending sleeve 98 having a spring 100 mounted within the axial passage 102 in the sleeve 98 by attachment. on one end to the internally threaded member 104, which is keyed in passage 102. Spring 100 is adjustable axially of sleeve 98 by, turning the adjustment screw 106 which is reached by moving theaccess screw 108. The other end of the spring 100 is secured to the governor weight 110 movable axially within the chamber 112. against the spring '100. The weight 110 has at the free end thereof a valve 114 which is adapted to close the orifice 116 when the weight 110 is forced outwardly due to the rotation of the shaft 96 and the sleeve 98 in accordance with engine or vehicle speed. The engine or vehicle speed at which the orifice 116 is closed is dependent, of course, upon the adjustment of .the spring 100. It should be understood that other governor valve structures may be employed.

A vacuum balancing air bleed is provided through the governor assembly 93 to chamber 46 when orifice 116 is uncovered. Conduit 118, between the air intake passage 16 of the carburetor and the housing 94, and conduit 122, between the housing 94 and the passage 123 in the body 36, are provided so that when the engine or vehicle is operating at a speed insuflicient to close the orifice 116, engine vacuum will draw clean air through the conduit 118 into the housing 94, through the orifice 116 into the chamber 112, through the passage 102 and the axial passage 120 in the shaft 96, and thence through the conduit 122 to the governor diaphragm assembly 30. When the engine reaches governed speed, the orifice 116 is nearly closed and the air bleed through conduit 122 is restricted. When this occurs and after a predetermined manifold vacuum is attained as will be subsequently described, the vacuum in the chamber 46 urges the diaphragm 42 downwardly, as viewed in FIGURE 1, against the spring 58 to close the throttle plate 24. As previously mentioned, in the past governing systems used a cut-off point, by means of restrictions in the cross vacuum bleed pickups, to aid in controlling or governing the engine. These systems were adequate in most cases, but it was found that in some cases, particularly with carburetors having'large bores, there was not enough vacuum to obtain the proper or desired cut-01f as just described.

' In order to overcome this problem, the governor cutoff valve 129 is provided for restricting the bleeding of manifold vacuum into the venturi vacuum line after the cut-off point is reached and a predetermined manifold vacuum is obtained. A piston 130 is provided in the body 36 beneath chamber 90 and has a spring 132 acting against the bottom thereof which biases the piston 130 in an upward direction as viewed in FIGURE 1. The tension of the spring 132 may be adjusted by means of the screw 134. It should be observed that passage 86 also connects piston chamber 131 with manifold vacuum. Tied into conduit 122 is conduit 136 which is connected to passage 138 and chamber 90.

The engine speed governor assembly 93 automatically adjusts the power input of the engine as the torque load decreases or increases, and acts in such a way as to prevent, within certain limits and under normal operating conditions, engine speed from exceeding a predetermined maximum. The governor assembly 93 is not in operation until the predetermined cut-off speed is approached under normal operating conditions. Under such normal operating conditions, the horsepower of the engine increases up to the governor cut-off speed at which point the governor assembly 93 begins to close to restrict the air bleed through conduit 122 to chamber 46and continues to close the throttle plate 24 as "further unloading of the engine takes place.

Prior to the :present invention, at speeds approaching the cut-off speed under normal operating conditions,

the throttle plate 24 is usually in a substantially open spOsitiOn. At such time the venturi vacuum is relatively 'high while'the manifold vacuum is relatively low. As

a result, the manifold vacuum bleeds into the venturi vacuum passage 88 thereby diluting the venturi vacuum. It has been found that under these conditions the governor vacuum which is provided by the combination of venturi and manifold vacuums, is not suflicient to ac 3 'tuate the fluid motor so as to obtain a satisfactory As a result, the spring 132 moves the piston 129 against the upper end of the chamber 131 to restrict the bleeding of manifold vacuum into the venturi vacuum passage 88. The relatively high venturi vacuum is sufficient, upon the closing of the orifice 116 provided in the governor assembly 93, to provide an initial actuating source for the fluid motor 30 so as to begin to move the throttle plate 24 in a direction to decrease the speed of the engine.

Immediately thereafter, once the throttle plate 24 starts to close, the manifold vacuum increases. Upon the attainment of a predetermined manifold vacuum as set by the adjustment 134, the pressure differential across the piston will have increased to a point where the pressure differential is greater than the force of spring 132. Consequently, the piston 130 is moved downwardly against the spring 132. As a result, the manifold and venturi vacuums again combine to provide the governing vacuum for controlling the position of the throttle plate 24. This is a gradual process, and the governing then becomes conventional, in that both manifold and venturi vacuums are used for throttle plate control.

FIGURE 2 shows a modification of the present invention and, where appropriate, the same numerical designations will be utilized. The specific modification relates to the governor cut-off valve.

The actuating device 30 and the speed sensing device 93 are schematically represented in FIGURE 2. Leading from the actuating device 30 is passage 123 which connects with the conduit 122. The modified cut-off valve includes a housing 142 which is'divided into a pair of chambers 144 and 146 by the movable diaphragm 148. The diaphragm is retained in between the divided parts of the housing 142 by appropriate fastening means such as screws 150. The housing 142 includes the cap 152 which carries an adjustment screw 154 and nut 156 exteriorly of the housing 142. The chamber 146 is vented to the atmosphere by means of passage or port 158. The housing 142 has an extension portion 160 which defines a chamber 162 which has a valve seat provided in wall 166. The wall 166 forms one side of chambers 162 and 168. Chamber 168 is connected by means of conduit 170 to manifold vacuum. The diaphragm 148 has fixed thereto a valve 174 which extends through an opening provided in the partition 176 dividing chambers 146 and 162. The valve member '174 extends through partition 176 and is axially in line with the valve seat 164. A spring 178 has one end which is seated against the member 180 carried by the adjustable screw 154 and has the other end urging the diaphragm 148, which carries the stem or valve member 174, in a valve closing direction. A nut 182 fits over the valve 174 and holds an 0 ring seal 184 in place.

Although the operation of this construction or modification is similar to the embodiment shown in FIG- URE 1, it will be briefly discussed. With the speed of the sensing or governing device 93 operating in a wellknown manner, and at some speed below the cut-off speed, the manifold vacuum is relatively high and causes the valve member 174 to move to the left so as to unseat the valve 174. This permits venturi vacuum and restricted manifold vacuum bleed to enter conduit 122. Also, inlet air passes through the engine speed governing device 93, conduit 122 to the chamber 46 provided in the actuating device 30. Hence, for carburetors of large bore diameters the transmitted pressure is not sufficrent to actuate the diaphragm 42.

At speeds approaching the cut-off speed, under normal operating conditions, the differential pressure across the diaphragm 148 is less than the force of spring 178. 'As a result, thespring 178 moves the valve member to the venturi vacuum passage 88. The relatively high venturi vacuum is suflicient upon the closing of the orifice 116 provided in the governor assembly 93 to provide an initial actuating source for the fluid motor 30 so as to begin to move the throttle 24 in a direction to decrease the speedof the engine. I

Immediately thereafter, once the throttle plate 24 begins to close, the manifold vacuum increases. Upon attainment of a predetermined manifold vacuum the pressure differential 'across the diaphragm 148 is greater than the force of spring 178. Consequently, the valve 174 is moved away fromthe valve seat 164. 'As a result, the manifold and venturi vacuums again combine to provide the governing vacuum for controlling the position of the throttle plate 24. As mentioned previously, this is a gradual process and the governing again becomes conventional in that both manifold and venturi vacuums provide a source of governing vacuum which is used for throttle plate control.

The drawings and the foregoing specification constitute a description of governor in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. An engine speed control mechanism for an internal combustion engine comprising a carburetor having a throttle, a venturi and a manifold, a fluid motor connected to said throttle for controlling the movement of said throttle, an engine speed governor for determining the cut-01f speed for the engine, an air bleed passage connecting said motor to the atmosphere through said governor to prevent operation of said motor, said bleed passage being substantially closed to atmosphere by the governor upon the approaching of the cut-off speed, wall means defining a pair of axially aligned cylinders of different diameters having their adjacent ends interconnected, a stop abutment formed by said wall means at the place where said cylinders intersect, one cylinder which has the smallest diameter being located above the other cylinder, a piston in said other cylinder, resilient means interposed between said piston and the remaining end of said other cylinder for biasing said piston towards said stop abutment, a first passage connecting said venturi to said one cylinder, a second passage connecting said manifold to the upper and lower portions of said other cylinder, and a third passage connecting said air bleed passage to said one cylinder, said piston being responsive to the force of the aforesaid resilient means and to the difference in manifold and venturi pressures on opposite sides thereof Which are effective to move said piston away from said stop abutment at speeds below the aforesaid cut-otf speed to permit the manifold and venturi vacuums to combine with the air in the air bleed passage, and which are effective upon the approaching of the aforesaid cut-off speed to move said piston against said stop abutment to block the entry of manifold vacuum into the upper portion of said other cylinder thereby preventing the bleeding of manifold vacuum into said first passage, said piston being held by said resilient means against said stop abutment for a relatively short period of time until the manifold vacuum increases to a predetermined value which is determined by the closing movement of said throttle as controlled by the venturi vacuum acting in said motor.

2. An engine speed control mechanism as defined in claim 1 wherein means are provided for adjusting the force of said resilient means.

3. An engine speed control mechanism for an internal combustion engine comprising a carburetor having a throttle, a venturi and a manifold, said venturi and manifold each providing a source of vacuum, a fluid motor connected to said throttle for controlling the movement of said throttle, an engine speed governor for determining the cut-off speed for the engine, an air bleed passage con- 6 t necting said motor to the atmosphere through said governor to prevent operation of said motor, said bleed passage being substantially closed to atmosphere by said governor upon the approaching of the cut-off speed, a first passage connecting said venturi to said motor, a second passage connecting said manifold to said motor, a venturi vacuum responsive valve in control of said second passage havingan open position and a closed position, an

expansible chamber having a movable wall connected to said valve, a third passage connecting said expansible chamber and second passage, said third passage being arranged parallel to said second passage and providing an unrestricted connection between said expansible chamber and the source of manifold vacuum, said expansible chamber being otherwise completely sealed so as to be at all times subjected to the full value of the instantaneous manifold vacuum, resilient means for biasing said movable Wall and valve in a direction to close said valve and block vacuum communication between said manifold and said motor, said movable wall and valve being responsive to the force of the aforesaid resilient means and to the manifold and venturi vacuums acting on said movable Wall and said valve respectively which are elfective to open said valve at speeds below the aforesaid cut-off speed to connect the manifold vacuum to said motor through said second passage, and which are effective upon the approaching of the aforesaid cut-off speed to close said valve to block vacuum communication between said manifold and said motor, said valve being held in a closed position for a relatively short period of time until the manifold vacuum increases to a predetermined value which is determined by the closing movement of said throttle as controlled by the venturi vacuum acting in said motor.

4. An engine speed control mechanism defined in claim 3 wherein said valve and said movable wall are integrally connected.

5. An engine speed control mechanism defined in claim 3 wherein said resilient means is in the form of a spring located in said expansible chamber.

6. An engine speed control mechanism defined in claim 5 wherein means are provided for varying the effectiveness of said spring.

7. An engine speed control mechanism for an internal combustion engine comprising a carburetor having a throttle, a venturi and a manifold, said venturi and manifold each providing a source of vacuum, a fluid motor connected to said throttle for controlling the movement of said throttle, an engine speed governor for determining the cut-off speed for the engine, an air bleed passage connecting said motor to the atmosphere through said governor to prevent operation of said motor, said bleed passage being substantially closed to atmosphere by the governor upon the approaching of the cut-off speed, a cut-off valve assembly including a housing, a wall dividing said housing into a pair of chambers, a valve seat in one of said chambers, a diaphragm in the other of said chambers which is subjected on one side thereof to atmospheric pressure, a valve stem connected on one end to said diaphragm and extending through an opening in said wall into said one chamber, a valve on the other end of said stem, which cooperates with said valve seat to form a variable orifice, means sealing the opening in said wall through which said stern extends, and resilient means biasing said valve towards said valve seat, a first passage connected to said manifold at a point below the throttle when the throttle is in a closed position, said first passage leading from said manifold to said one chamber through said variable orifice and to said other chamber at the other side of said diaphragm, a second passage connecting said venturi to said one chamber, and a third passage connecting said air bleed passage to said one chamber, said diaphragm being responsive to the difference in manifold vacuum and atmospheric pressure which is effective to move said valve member away from said valve seat against said resilient means at speeds below the aforesaid cut-off speed to connect the manifold and venturi vacuums to said air bleed passage, and which is effective upon the approaching of the aforesaid cut-off speed when the force of said resilient means is greater than said diflerence to move said valve member against said valve seat to block the entry of manifold vacuum into said one chamber to prevent the bleeding of manifold vacuum into said sec- 0nd passage, said valve member being held against said valve seat by said resilient means until the manifold vacuum increases to a predetermined value initiated by the closing movement of said throttle as controlled by the venturi vacuum acting in said motor.

8/ An engine speed control mechanism defined in claim 3 wherein said movable wall' is in the form of a diaphragm which is operatively connected to said valve.

References Cited in the file of this patent UNITED STATES PATENTS 2,315,912 Udale Apr. 6, 1943 2,356,017 Udale Aug. 15, 1944 2,362,655 Mallory Nov. 14, 1944 2,450,037 Dulong Sept. 28, 1948

Claims (1)

1. 7. AN ENGINE SPEED CONTROL MECHANISM FOR AN INTERNAL COMBUSTION ENGINE COMPRISING A CARBURETOR HAVING A THROTTLE, A VENTURI AND A MANIFOLD, SAID VENTURI AND MANIFOLD EACH PROVIDING A SOURCE OF VACUUM, A FLUID MOTOR CONNECTED TO SAID THROTTLE FOR CONTROLLING THE MOVEMENT OF SAID THROTTLE, AN ENGINE SPEED GOVERNOR FOR DETERMINING THE CUT-OFF SPEED FOR THE ENGINE, AN AIR BLEED PASSAGE CONNECTING SAID MOTOR TO THE ATMOSPHERE THROUGH SAID GOVERNOR TO PREVENT OPERATION OF SAID MOTOR, SAID BLEED PASSAGE BEING SUBSTANTIALLY CLOSED TO ATMOSPHERE BY THE GOVERNOR UPON THE APPROACHING OF THE CUT-OFF SPEED, A CUT-OFF VALVE ASSEMBLY INCLUDING A HOUSING, A WALL DIVIDING SAID HOUSING INTO A PAIR OF CHAMBERS, A VALVE SEAT IN ONE OF SAID CHAMBERS, A DIAPHRAGM IN THE OTHER OF SAID CHAMBERS WHICH IS SUBJECTED ON ONE SIDE THEREOF TO ATMOSPHERIC PRESSURE, A VALVE STEM CONNECTED ON ONE END TO SAID DIAPHRAGM AND EXTENDING THROUGH AN OPENING IN SAID WALL INTO SAID ONE CHAMBER, A VALVE ON THE OTHER END OF SAID STEM, WHICH COOPERATES WITH SAID VALVE SEAT TO FORM A VARIABLE ORIFICE, MEANS SEALING THE OPENING IN SAID WALL THROUGH WHICH SAID STEM EXTENDS, AND RESILIENT MEANS BIASING SAID VALVE TOWARDS SAID VALVE SEAT, A FIRST PASSAGE CONNECTED TO SAID MANIFOLD AT A POINT BELOW THE THROTTLE WHEN THE THROTTLE IS IN A CLOSED POSITION, SAID FIRST PASSAGE LEADING FROM SAID MANIFOLD TO SAID ONE CHAMBER THROUGH SAID VARIABLE ORIFICE AND TO SAID OTHER CHAMBER AT THE OTHER SIDE OF SAID DIAPHRAGM, A SECOND PASSAGE CONNECTING SAID VENTURI TO SAID ONE CHAMBER, AND A THIRD PASSAGE CONNECTING SAID AIR BLEED PASSAGE TO SAID ONE CHAMBER, SAID DIAPHRAGM BEING RESPONSIVE TO THE DIFFERENCE IN MANIFOLD VACUUM AND ATMOSPHERIC PRESSURE WHICH IS EFFECTIVE TO MOVE SAID VALVE MEMBER AWAY FROM SAID VALVE SEAT AGAINST SAID RESILIENT MEANS AT SPEEDS BELOW THE AFORESAID CUT-OFF SPEED TO CONNECT THE MANIFOLD AND VENTURI VACUUMS TO SAID AIR BLEED PASSAGE, AND WHICH IS EFFECTIVE UPON THE APPROACHING OF THE AFORESAID CUT-OFF SPEED WHEN THE FORCE OF SAID RESILIENT MEANS IS GREATER THAN SAID DIFFERENCE TO MOVE SAID VALVE MEMBER AGAINST SAID VALVE SEAT TO BLOCK THE ENTRY OF MANIFOLD VACUUM INTO SAID ONE CHAMBER TO PREVENT THE BLEEDING OF MANIFOLD VACUUM INTO SAID SECOND PASSAGE, SAID VALVE MEMBER BEING HELD AGAINST SAID VALVE SEAT BY SAID RESILIENT MEANS UNTIL THE MANIFOLD VACUUM INCREASES TO A PREDETERMINED VALUE INITIATED BY THE CLOSING MOVEMENT OF SAID THROTTLE AS CONTROLLED BY THE VENTURI VACUUM ACTING IN SAID MOTOR.

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