US3116906A - Throttle valve actuating apparatus - Google Patents

Description

Jam. 7, 1964 3,116,906

L- F. CALLAHAN THROTTLE VALVE ACTUATING APPARATUS Filed July 21, 51.961

' FIGQ 50 Y 4/ FIG.IO

INVENTOR.

LAWRENCE F CALLAHAN ATTORNEY United States Patent G THROTTLE VALVE ACTUATING APPARATUS Lawrence F. Callahan, Kenosha, Wis., assignor to American Motors Corporation, Kenosha, Wis., a corporation of Maryland Filed July 21, 1961, Ser. No. 125,737 8 Claims. (Cl. 251-64) The invention relates to a throttle valve actuating device for an internal combustion engine and has particular reference to a mechanism for momentarily retarding valve closing throughout the final few degrees of valve operating range.

The principal object of the invention is to provide mechanical means for momentarily retarding final valve closing.

Another object is to provide such a mechanism for the purpose of reducing the possibility of killing the engine by too rapid valve closing.

A further specific object of the invention is to provide mechanism for effecting limited frictional resistance to valve closing throughout the final 4 or degrees of the valve closing range.

Other objects and advantages of the invention will be apparent from the ensuing specification and appended drawing in which:

FIG. 1 is a side elevational view of a typical throttle valve actuating apparatus employing the inventive subject matter.

FIG. 2 is a fragmentary end view taken generally on the line 22 of PEG. 1 with parts broken in section.

FIG. 3 is a fragmentary view taken on the line 33 of FIG. 2 with parts broken in section.

FIG. 4 is a fragmentary view taken on the line 44 of FIG. 2, but with the throttle valve rotated to closed position.

FIG. 5 is a detail plan view of one component.

FIG. 6 is a detail plan view of another component.

FIG. 7 is a fragmentary sectional view similar to FIG. 3 but showing a modified form of the invention.

FIG. 8 is a detail plan view of a component of the device shown in FIG. 7.

FIG. 9 is a sectional detail view taken generally on the line 99 of 'FIG. 1.

FIG. 10 is a fragmentary sectional detail view of the end portion of the throttle valve shaft.

Referring to FIG. 1, I have shown a typical throttle valve actuating assembly as utilized in an automotive vehicle. A carburetor A is mounted on engine B and the throttle valve C is actuated by the rotation of accelerator shaft D. A foot pedal E is initially actuated for effecting rotation of the accelerator shaft.

The accelerator pedal E is mounted on the toeboard 10 and its upper end is connected to actuating rod 11 which projects through a suitable opening 12 in the toeboard. A bracket 13 has its base portion anchored to the toeboard as by means of screws 14. Crank 15 is carried by the bracket and one crank arm 16 is pivotally connected at 17 to the inner end of the actuating rod 11 and crank arm 18 is pivotally connected at 19 to the lower end of link 20. The upper end of link 20" is pivotally connected to the bracket 22 which is anchored, as by welding, to the accelerator shaft D.

A bracket 23 is anchored at its lower end to the side face of bracket 13 and carries a bearing 24 at its upper end. The bearing rotatively accommodates the outer end 25 of the accelerator shaft.

A tension spring 27 has one end 28 anchored to the bracket 13 and its other end 29 anchored to the pivot pin 17 which interconnects the crank arm 16 and actuating rod 11.

3 ,116,906 Patented Jan. 7, 1964 All of the foregoing throttle valve actuating mechanism forms the subject matter of a co-pending patent application, Serial No. 122,492, filed on July 7, 1961.

The throttle valve C is mounted within the carburetor housing 31 on the throttle valve shaft 32. The valve shaft projects exteriorly of the carburetor housing and has a bracket '33 anchored to the outer end thereof. The accelerator shaft D is bent at 34 and at 35 to provide the transverse end portion 36 which extends through the aligned openings 38 and 39 in bracket 33. Thus, rotation of the accelerator shaft is transmitted to the valve shaft 32 via rotation of bracket 3-3.

Referring to FIGS. 2 and 10, it will be noted that the outer end of the valve shaft has diametrically opposed flats 40 and 41 which lock the bracket 33 to the shaft so that it effects rotation of said shaft. A second set of diametrically opposed flats 42 and 43 serve to accommodate the spring Washer 45 and cam Washer 46. At the ends of the flats 4t) and 41 radially extending shoulders 47 and 48 are formed, against which the underside of bracket 33 bottoms.w The head portion 50 at the outer end of the valve shaft anchors the bracket against axial movement relative to said shaft.

Referring to FIGS. 5 and 6, the spring washer 45 is provided with a central opening 52 with flats 53 and 54 which coact with the shaft flats 42 and 43. The cam washer 46 likewise has a central opening 55 with flats 56 and 57 which coact with shaft flats 42 and 43. The cam washer has a cam surface identified generally with the numeral 58 formed therein, preferably as by means of a punch press operation. At the ends of the shaft flats 42 and 43 shoulders 60 and 61 are formed and when the underside 62 of the cam washer engages said shoulders under the influence of spring washer 45, the apex portion 63 of the cam will be slightly spaced from the end face 64 of the carburetor housing 31. A plug 65 may be pressed into the end wall of the carburetor housing and has a semi-spherical end surface 66 projecting outwardly therefrom. When the underside 62 of the cam washer is in contact with shaft shoulders 60 and 61, then there is preferably a slight clearance between the end of the nose portion 66 and the underside of the cam washer.

When the throttle valve moves to within 4 or 5 degrees of fully closed position, the inital portion 68 of the cam engages the nose of the plug 65 and when the throttle valve reaches fully closed position, the apex portion 63 of the cam will be resting on the plug nose as viewed in FIG. 4 and the spring washer 45 will be substantially fully compressed between the underside. 70 of the bracket 33 and the upper side 71 of the cam washer as shown in FIG. 4.

In the modified form of the invention as shown in FIGS. 7 and 8, the spring washer and cam means are incorporated in one component. The component is provided with a central opening having flats 81 and 82 which coact with the shaft flats 83 (only one of which is shown in FIG. 7). The washer forms a nearly complete circle; however, the gap 84 between the ends 85 and 86 make it possible to utilize the cam 87 as the spring (comparable to the spring washer 45). When the underside 88 of the washer is in contact with the shaft.

shoulders provided at the ends of the flats 83, there will preferably be a slight clearance between the cam and the end shoulder 64a of the carburetor housing and between the underside of the washer and the end 66a of the plug 65a.

Operation In the operation of the throttle valve actuating apparatus, the accelerator pedal is depressed to effect opening of the throttle valve. Downward movement of such pedal causes rod 11 to swing the crank arm 16 and 18 clockwise about the horizontal axis 90. Crank arm 18 pulls link 2% and bracket 22 downward to effect rotation of accelerator shaft D in a counter-clockwise direction viewing FIG. 9. Rotation of such shaft to fully open valve position will rotate the valve shaft 32 and bracket 33 to the position as indicated in FIG. 2. When the foot pressure on the accelerator pedal is released, the return spring 27 takes over and automatically returns the valve to fully closed posiiton. In fully closed position, the apex of the cam will overlie the nose of the plug 65 as shown in FIG. 4.

Viewing FIG. 2, the closing of the valve will cause ro tation of the bracket 33 clockwise to a position approximately 80 degrees beyond that shown in FIG. 2. The range of movement of the accelerator shaft from fully opened to fully closed position is indicated by the dimension X. Open position is indicated by the line 95 and closed position is indicated by the line 96. The final 4 or 5 degrees of valve closing is indicated by the dimension Y and it is during this range of movement of the valve shaft that the cam commences riding up on nose 66 against the resistance offered by the spring washer 45 until the washer is substantially flattened as indicated in FIG. 4. The resistance occasioned by the spring washer is calibrated in conjunction with the tension exerted by spring 27 so that the final 4 or 5 degrees of valve closing results in a slowing down of the closing movement of the valve shaft thereby preventing an abrupt valve closing condition. Thus, the likelihood of the engine dying as a result of abrupt valve closing is lessened.

Viewing FIG. 3, it will be noted that the clearance shown, for example, between the periphery of the spring washer 45 and the underside 70 of bracket 33 is greatly exaggerated for purposes of clarity in detail of the drawing; however, in practice the clearance between the various components need only be such as to assure that little or no frictional drag occurs during valve opening and closing throughout the range of operation other than the final few degrees of closing. Thus, in FIG. 3 the clearance shown between washer surface 62 and nose 65 and the clearance shown between the cam apex 63 and carburetor housing face 64 are also exaggerated.

Clearance exaggeration also exists in FIG. 7 between washer face 88 and nose 66a and between the cam surface and carburetor housing wall 64a.

I claim:

1. A carburetor throttle valve control mechanism comprising: a throttle valve; a shaft for rotatively actuating the valve between closed and open positions; a carburetor housing rotatively supporting the shaft, said shaft projecting beyond an end wall of the housing; means for actuating the rotation of the shaft to open the valve; spring means for effecting rotation of the shaft automatically to close the valve and means for resisting the valve closing effort of the spring means immediately prior to such valve reaching fully closed position, said means comprising: a cam surface rotatable with the shaft; an abutment on the carburetor housing situated in the path of rotation of the cam surface and resilient means on the shaft and being energized when the cam surface rides over the abutment.

2. A carburetor throttle valve control mechanism comprising: a carburetor housing; a throttle valve within the housing; a valve shaft carrying the valve and being rotatably supported by the housing and having an end projecting through one wall of the housing; means for effecting rotation of the shaft in valve opening direction to open the valve; spring means for automatically rotating the shaft in valve closing direction upon inactivation of the valve opening means; and means for resisting the valve closing effort of the spring means immediately prior to such valve reaching fully closed position, said means comprising: a cam surface rotatable With the shaft; cam receiving means non-rotatable with reference to the shaft and situated in the path of rotation of the cam surface and resilient means on the shaft for resisting movement of the cam surface over the cam receiving means.

3. A carburetor throttle valve control mechanism comprising: a carburetor housing; a throttle valve within the housing; a valve shaft carrying the valve and being rotatably supported by the housing and having an end projecting through one wall of the housing; means for effecting rotation of the shaft in valve opening direction to open the valve; spring means for automatically rotating the shaft in valve closing direction upon inactivation of the valve opening means; and means for resisting the valve closing effort of the spring means immediately prior to such valve reaching fully closed position, said means comprising: a washer non-rotatably mounted on the shaft and axially movable relative thereto; a cam surface on the washer; an abutment on the carburetor housing wall and situated in the path of rotation of the cam surface; resilient means on the shaft and normally urging the Washer in an axial direction along the shaft toward the abutment, said cam surface riding over the abutment and the resilient means serving to resist the riding of the cam surface over the abutment.

4. Apparatus as set forth in claim 3 wherein the torque load imposed on the shaft by the spring means in rotating the shaft in valve ciosing direction exceeds the resistance to such torque load occasioned by the resilient means as the cam surface rides over the abutment.

5. Apparatus as set forth in claim 3 wherein the shaft has a shoulder for limiting the axial movement of the Washer toward the abutment.

6. A carburetor throttle Valve control mechanism comprising: a carburetor housing; a throttle valve within the housing; a valve shaft carrying the valve and being rotatably supported by the housing and having an end projecting through one wall of the housing; means for effecting rotation of the shaft in valve opening direction to open the valve; spring means for automatically rotating the shaft in valve closing direction upon inactivation of the valve opening means; and means for resisting the valve closing effort of the spring means immediately prior to such valve reaching fully closed position, said means comprising: a washer non-rotatahly mounted on the shaft and axially movable relative thereto; a resilient cam surface on the washer; an abutment on the carburetor housing wall and situated in the path of rotation of the cam surface; said resilient cam surface riding over the abutment and simultaneously serving to resist the rotative torque imparted to the shaft by the spring means.

7. A carburetor throttle valve control mechanism comprising: a throttle valve; a shaft for rotatively actuating the vaive between closed and open positions; a carburetor housing rotatively supporting the shaft, said shaft projecting beyond an end wall of the housing; means for actuating the rotation of the shaft to open the valve; spring means for effecting rotation of the shaft automatically to close the valve and means for resisting the valve closing effort of the spring means immediately prior to such valve reaching fully closed position, said means comprising: cam means and resilient means associated with the shaft and with the carburetor housing; whereby rotation of the shaft in valve closing direction throughout the final few degrees of rotative movement causes energizing of the resilient means to effect such resistance to valve closing.

8. A carburetor throttle valve control mechanism comprising: a carburetor housing; a throttle valve within the housing; a valve shaft carrying the valve and being rotatably supported by the housing and having an end projecting through one wall of the housing; means for effecting rotation of the shaft in valve opening direction to open the valve; spring means for automatically rotating the shaft in valve closing direction upon inactivation of the valve opening means; and means for resisting the valve closing effort of the spring means immediately prior to such valve reaching fully closed position, said means comprising: a cam surface mounted on the shaft for axial movement relative thereto and being rotatable with the shaft; cam receiving means non-rotatable with reference to the shaft and situated in the path of rotation of the cam surface and resilient means on the shaft and being energized when the cam surface moves over the cam receiving means, thereby resisting the movement of the cam surface over the cam receiving means.

References Cited in the file of this patent UNITED STATES PATENTS

Claims (1)

1. A CARBURETOR THROTTLE VALVE CONTROL MECHANISM COMPRISING: A THROTTLE VALVE; A SHAFT FOR ROTATIVELY ACTUATING THE VALVE BETWEEN CLOSED AND OPEN POSITIONS; A CARBURETOR HOUSING ROTATIVELY SUPPORTING THE SHAFT, SAID SHAFT PROJECTING BEYOND AN END WALL OF THE HOUSING; MEANS FOR ACTUATING THE ROTATION OF THE SHAFT TO OPEN THE VALVE; SPRING MEANS FOR EFFECTING ROTATION OF THE SHAFT AUTOMATICALLY TO CLOSE THE VALVE AND MEANS FOR RESISTING THE VALVE CLOSING EFFORT OF THE SPRING MEANS IMMEDIATELY PRIOR TO SUCH VALVE REACHING FULLY CLOSED POSITION, SAID MEANS COMPRISING: A CAM SURFACE ROTATABLE WITH THE SHAFT; AN ABUTMENT ON THE CARBURETOR HOUSING SITUATED IN THE PATH OF ROTATION OF THE CAM SURFACE AND RESILIENT MEANS ON THE SHAFT AND BEING ENERGIZED WHEN THE CAM SURFACE RIDES OVER THE ABUTMENT.

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