US3635254A

US3635254A - Valve assembly

Info

Publication number: US3635254A
Application number: US850829A
Authority: US
Inventors: Robert D Mitchell
Original assignee: Holley Carburetor Co
Current assignee: Holley Performance Products Inc
Priority date: 1969-08-18
Filing date: 1969-08-18
Publication date: 1972-01-18
Anticipated expiration: 1989-01-18

Abstract

A valve assembly having a housing with an inlet and outlet, has a stem valve situated therein and resiliently urged in the flowincreasing direction; a collarlike member slidably contained within the housing and carried by the stem valve is, upon application of sufficient force, movable with respect to the stem valve; when the stem valve is forced in the flow-decreasing direction the collar is held against movement by an abutment permitting relative motion between the stem valve and collar with such relative motion continuing until a predetermined rate of flow is attained through the valve assembly.

Description

nited States Patent 51 Jan. 18, 1972 itchell VALVE ASSEMBLY [72] Inventor: Robert D. Mitchell, Madison Heights,

Mich.

[73] Assignee: Holley Carburetor Company, Warren.

Mich.

[22] Filed: Aug. 18, 1969 [211 App]. No.: 850,829

[52] U.S.Cl.... ..l38/45, 251/122, 251/285 [5 1] Int. Cl ..Fl5d 1/00 [58] Field 0! Search 138/45; 251/122, 285

[56] References Cited UNITED STATES PATENTS 2,147,945 211939 Hann et al ..25i/285 X Primary Examiner-Laverne D. Geiger Assistant Examiner-Richard J. Sher Attorney-Walter Potoroka, Sr.

[57] ABSTRACT A valve assembly having a housing with an inlet and outlet, has a stem valve situated therein and resiliently urged in the flowincreasing direction; a collurlike member slidubly contained within the housing and carried by the stem valve is, upon upplication of sufficient force. movable with respect to the stem valve; when the stem valve is forced in the flow-decreasing direction the collar is held against movement by an abutment permitting relative motion between the stem valve and collar with such relative motion continuing until a predetermined rate of flow is attained through the valve assembly.

5 Claims, 3 Drawing Figures a /0,,U',; -f kg m: t E2: 206 I c; r 2 g:

1 VALVE ASSEMBLY BACKGROUND OF THE INVENTION In air valve type of carburetors, as well as other types of carburetors employing movable fuel metering rods, it is accepted practice, in the prior art, to employ such things as cams and/or levers to move the metering rods in accordance with sensed parameters as indicated, for example, by the angular deflection of the air valve within an air valve type carburetor.

The metering rods are thusly raised or lowered through a cooperating metering orifice or jet which is separately secured to the body of the carburetor. This arrangement results in at least two major disadvantages. That is, first, the installation of such metering rods into the metering orifices becomes difficult in that the rods must somehow be guided into place within such metering orifices. This process usually requires several attempts. Secondly, such rods assembled within the carburetor must be tested and somehow adjusted for both rates of flow as well as equal minimum flows on carburetor fuel test stands which, again, is difficult and time consuming.

The invention as herein disclosed is concerned with the solution of the above as well as other problems.

SUMMARY OF THE INVENTION According to the invention, a valve assembly comprises a housing, means formed at a first end of said housing for detachably securing said housing to an associated structure, outlet conduit means fonned in said first end, inlet. conduit means formed through a wall of said housing for communication with a source of fluid to be metered by said valve assembly, a valve orifice formedin said housing generally between said inlet conduit means and said outlet conduit means, an axially movable valve member at least partly received within said housing and movable toward and away from said valve orifice, said valve member including a contoured metering surface adapted to be received within said valve orifice, said contoured surface and said valve orifice being effective to cooperatively define therebetween varying effective flow areas for the metering therebetween of said fluid, and first and second abutment means carried respectively by said housing and said valve member, said first and second abutment means being normally effective to at times effect abutting engagement therebetween and thereby establish a predetermined relationship between said contoured surface and said valve orifice in order to define therebetween a predetermined effective flow area, at least one of said abutment means being forcibly movable in order to adjust the distance by which said valve member can be normally moved toward said valve orifice.

Accordingly, a general object of this invention is to provide a valving arrangement or assembly which can be, as a unit, quickly and easily assembled to or removed from a cooperating structure and which, further, has abutment means which, at times, can be forcibly moved with respect to one of the valving components carrying such abutment means in order to quickly establish a predetermined effective metering orifice therein.

Other more specific objects and advantages of the invention will come apparent when reference is made to the following detai ed description considered in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS In the drawings, wherein certain details may be omitted from one or more views for purposes of clarity:

FIG. I is an elevational cross-sectional view of a carburetor structure employing the invention;

FIG. 2 is an enlarged axial cross-sectional view of the valve assembly shown in FIG. 1 but with certain elements thereof illustrated in operating positions different from that shown in FIG. I; and

FIG. 3 is a view similar to that of FIG. 2 but showing the various elements in operating positions the same as that shown in FIG. I.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in greater detail to the drawings, FIG. I illustrates a carburetor 10 having a body 12 with at least one primary bore or induction passage I4 and at least one secondary bore or induction passage 16 formed therethrough so as to have the discharge ends thereof respectively communicating with inlets l8 and 20 of the engine intake manifold 22.

A main fuel discharge nozzle 24, situated generally within the throat 26 of a venturi 27 formed in the induction passage 14, communicates with the primary fuel bowl 28 as by means of a conduit 30 and suitable fuel metering means (not shown), in a manner well known in the art, in order to at times discharge fuel into the induction passage in accordance with the rate of airflow through the venturi 27.

Additionally, an idle and part throttle fuel system, including ports 32 and 34 for discharging fuel into the induction passage 14 during idle and part throttle engine operation, is in commu nication with the fuel bowl 28 as by means of a conduit 36 and suitable fuel-metering means (not shown).

A throttle valve 38, secured to a throttle shaft 40 for rotation therewith, is situated within induction passage 14 for controlling the discharge therethrough of combustible mixture into the inlet 18 of intake manifold 22. The opposite end of induction passage 14 may be provided with a choke valve 42 secured to a choke shaft 44, for rotation therewith, in order to at times provide a degree of restriction to the flow of air therethrough. The choke valve 42 may be positioned by any suitable means either manually or automatically controlled many of which are well known in the art. As fragmentarily illustrated, the upper portion of carburetor body 12 may be provided with a suitable air cleaner assembly 46.

The secondary induction passage 16 is illustrated as containing a throttle valve 48, suitably secured to a throttle shaft 50 for rotation therewith, and an air valve 52 secured to a shaft 54 for rotation therewith. Shaft 54 is also provided with actuating cam means 56 which may be adjustably angularly positioned with respect to both the air valve 52 and shaft 54 as by an adjustment screw 58.

A fuel discharge nozzle 60 having an open end 62 for discharging fuel into the induction passage 16, communicates at its other end, via conduit means 64 and fuel valve means 66 in series therewith, with the fuel supply within the fuel bowl 68. Suitable lever means 70 (somewhat schematically shown) pivoted as at 72 serves to operatively interconnect the air valve 52 and the valve assembly 66.

FIG. 2, an enlarged fragmentary portion of FIG. 1, illustrates the valve assembly 66 as being comprised of an outer generally tubular housing 74 having an open upper end 76 and an open lower end defining a conduit portion 78 which is also provided with an externally threaded portion 80 which, as illustrated, is adapted to threadably engage an internally threaded portion 82 in a lower wall 84 of fuel bowl 68. An elongated valve stem 86 situated generally within the housing 74 is provided with a lower tapered or contoured surface 88 which, as will be seen, cooperates with an orifice 90 formed in the ringlike member 92 being of relatively thin cross section can be snapped into a circumferential groove formed in the wall of conduit portion 78 or, if desired, may be initially set onto a circumferential shoulder formed in the wall of conduit 78 and retained thereagainst as by peening over the portion illustrated at 94.

A second shoulder 96 serves to retain an annular spring abutment 98 for abuttably engaging the lower end of a compression spring 100 which has its upper end engaging the lower surface 102 of a movable annular stop-guide 104 which is slidingly received with the cylindrical portion 106 of housing 74 while being press-fitted onto the cylindrical surface portion 108 of stem 86. A third internally formed annular shoulder 110 provides a positive stop or gauging surface against which the lower surface 102 of collarlike guide 104 is at times abutted.

An upper annular stop member 112, which may be pressfitted on its outer diameter into the cylindrical surface 106,

has an inner diameter 114 which slidably receives the portion 108 of stem 86 therethrough. As first seen in FIG. 1, the upper end 116 of valve stem 86 is adapted to be in contact with the end of arm portion 118 of lever 70 so as to be axially positioned in accordance with the movement of lever 70. The housing 74 is preferably provided with suitable tool-engaging surfaces such as the radially directed notches or recesses 120 formed at the upper end thereof whereby the entire valve assembly 66 may be positively threadably engaged with portion 82 and seated as against a suitable annular seal 122. Further, housing 74 is preferably provided with a plurality of radially directed orifices or

conduit portions

124 and 126 which collectively form inlet means for the fuel within the bowl 68.

As is well known in the art, an air valve type of carburetor differs from the other common type of carburetor primarily in that no main venturi (such as venturi 27) is provided within the secondary induction passage for creating a venturi vacuum of a value varying in accordance with the velocity air rate flow through the venturi throat. (Such venturi vacuum" is employed for causing metered fuel flow from the associated fuel bowl to the main nozzle.) Instead of such a venturi, the air valve type carburetor employs a pivotally supported air valve, upstream of the throttle valve, which functions, by deflecting in accordance therewith the opening and closing of an associated fuel metering valve so as to thereby provide the proper fuel-air ratio of the combustible mixture being discharged by the carburetor into the engine intake manifold.

OPERATION OF THE INVENTION In view of the above, and with reference to primarily FIGS. 1 and 2, the operation of the invention is briefly as follows. During engine shut down, the air valve 52 is maintained in its nominally closed position somewhat as illustrated in FIG. 1. (In order to do this a suitable spring, not shown, may be employed and operatively connected to the air valve shaft 54in a manner as to resist opening movements of the air valve 52. In such situations it is also good practice to provide means whereby such resilient resistance can be varied or adjusted as to meet the particular air requirements of the associated engine.)

When the engine is started and becomes self-sustaining and the throttle valve 48 possibly rotated to some part throttle position, the airflow through the secondary induction passage 16 causes the air valve 52 and shaft 54 to rotate some amount counterclockwise, as viewed in FIG. 1, thereby permitting spring 100 of valve assembly 66 to urge valve stem 86 upwardly against arm end 118 of lever 70. Consequently, lever 70 is rotated some amount counterclockwise about its pivot 72 maintaining portion 71 in contact with the contoured surface 88 forrned thereon, results in a larger effective flow area being defined between stem valve surface 88 and the orifice 90 of valve orifice member 92. This in turn permits a greater rate of fuel flow from fuel bowl 68 through inlet means 124, 126, through the effective flow area of orifice 90, through

conduits

78 and 64 and finally discharged into induction passage 16 by means of nozzle 60.

In view of the above it can be seen that generally as air valve 52 is increasingly opened stern valve 86 is correspondingly moved upwardly thereby providing for greater rate of fuel flow through the metering orifice collectively defined by orifice 90 and contoured stern valve surface 88.

The valve assembly 66 provides a number of advantages, some of which can be better understood if reference is made to FIGS. 2 and 3 and consideration is given to the method of constructing or assembling the valve assembly. For example, once the components comprising the valve assembly 66 are formed, the valve orifice member 92 is assembled to housing 74, which may be threadably engaged to a suitable connector or coupling 130 as illustrated in FIG. 3, and then the lower spring seat 98 is slipped down against shoulder 96. Following this, spring 100 is placed-within housing 74 against the spring seat 98. Next, the collar or guide 104 is placed within the upper open end 76 of cylinder 106, thereby causing a slight compression of spring 100, and held in such position while the stern valve 86 is inserted'through the inner diameter 128 of collar guide 104.

It should be remembered that the inner diameter 128 is slightly smaller than the diameter of cylindrical portion 108 of stem valve 86. Therefore, because of such an interfering fit therebetween, the inner diameter 128 of collar guide 104 will initially be engaged at some point along the tapered or contoured surface 88.

Suitable flow test equipment may be provided and operatively connected to the valve assembly 66 as generally illustrated by phantom line in FIG. 3. For example, a source of fuel (or fuel-simulating fluid, as the case may be) 132 is effective for supplying fuel, via conduit means 134 and 136 and a suitable fuel flow rate meter or readout device 138 serially connected therewith, to a suitable housing 140 detachably secured to the housing 74 so as to enable the fuel supplied thereto to flow through the inlet means 124 and 126. The conduit portion 142 of connector 130, in turn, communicates with a suitable low-pressure sink or receiver 144.

With the test fluid flowing into

inlets

124 and 126 and out through conduit 142, and with the elements of the valve assembly 66 in the conditions described above, the stem valve 86, along with the collar guide 104 situated on the tapered portion 88, is moved downwardly against the resistance of spring until the lower surface 102 of collar 104 engages and abuts against the shoulder 110. When this occurs, the stem valve 86 is forced downwardly through the collar 104 (the further movement of which is prevented by shoulder causing the collar 104 to be pressed onto the cylindrical surface 108 of stem valve 86.

Such downward movement of stem valve 86 is forcibly continued while the fuel-rate readout device 138 is continually observed until such device 138 indicates that a predetermined rate of fuel flow (as controlled by the effective flow area defined between tapered surface 88 and fixed orifice 90) has been achieved. When this happens, the stern valve 86 is no longer forced downwardly relative to the collar 104 and, as a consequence thereof, the predetermined rate of fuel flow is simultaneously attained. In the structure illustrated the said predetermined rate of fuel flow is a predetermined minimum rate of flow; therefore, it can be seen that anytime the lever 70 (FIG. 1) moves stem valve 86 downwardly to a point whereat collar 104 abuts against shoulder 110, the valve assembly 66 will deliver the predetermined minimum rate of fuel flow to the nozzle 60. It should, of course, be apparent that the lever 70, and mechanism associated therewith, is incapable of producing a force on stem valve 86 sufficient to cause relative motion between stem valve 86 and collar 104 after the collar 104 abuts against shoulder 110.

After the relative positions of stem valve 86 and collar or minimum fuel flow stop 104 have been established as set forth above, the upper stop or maximum fuel flow limiter 112 may be press-fitted into the upper open end 76 of cylinder 106. The position of stop 112 is so selected as to cause the stop to function as a maximum fuel overtravel stop.

In view of the preceding it can be seen that the invention provides a valve assembly 66 which is an integral self-contained assembly which can be quickly and easily threadably secured to a carburetor structure (or removed therefrom for replacement purposes) without any attendant problems of alignment because the valve housing 74, stem valve 86 and related details constitute a unitary package. Further, the valve assembly 66 can be checked by itself for proper metering characteristics and, as well, have its predetermined minimum rate of fuel flow accurately and quickly established prior to its incorporation into the carburetor structure. This becomes an important advantage in the assembly of the overall carburetor because, once the valve assembly 66 is assembled to the carburetor a built-in stop (provided by the coaction of minimum flow stop collar 104 and shoulder 110) exists for the determination of the other related carburetor components. That is,

the air valve 52 is first positioned in its corresponding position and then the actuating lever means, such as lever 70, is adjusted so as to cause the stem valve 86 to be depressed until the collar 104$ abuts against shoulder 110, thereby automatically determining the exact positions of all components for establishing the required minimum rate of fuel flow and the overall flow range qualification setting for portion 88.

The carburetor 10, has been illustrated mainly for the purpose of providing an environment in which the operation and benefits of the valve assembly 66 could be better described. However, it should be clear that the valve assembly of the invention is not limited to use merely with such a carburetor structure or to a carburetor at all.

Although only one preferred embodiment of the invention has been disclosed and described, it is apparent that other embodiments and modifications are possible within the scope of the invention as defined by the appended claims.

I claim:

1. A valve assembly, comprising a housing, means formed at a first end of said housing for detachably securing said housing to an associated structure, outlet conduit means formed in said first end, inlet conduit means formed through a wall of said housing for communication with a source of fluid to be metered by said valve assembly, a valve orifice formed in said housing generally between said inlet conduit means and said outlet conduit means, an axially moveable valve member at least partly received within said housing and moveable toward and away from said valve orifice, said valve member including a contoured metering surface adapted to be received within said orifice, said contoured surface and said valve orifice being effective to cooperatively define therebetween progressively varying effective flow areas between a minimum flow area and a maximum flow area for the metering therethrough of said fluid, the end of said valve member, which is opposite the end thereof received within said orifice, protruding beyond said housing so as to be adapted for actuation by means positioned externally of said housing, first and second abutment means carried respectively by said housing and said valve member, said first and second abutment means being normally effective to at times effect abutting engagement therebetween and thereby establish a predetermined relationship between said contoured surface and said valve orifice in order to define therebetween a predetermined effective flow area, said first and second abutment means being normally fixed but being forcibly movable with respect to each other in order to adjust the distance said valve member can normally be moved toward and away from said orifice, said second abutment means being freely slidably received within said housing, and spring means operative between said housing and said second abutment means for normally resiliently urging said valve member in a direction away from said valve orifice.

2. A valve assembly according to claim 1 wherein said means formed at a first end of said housing for detachably securing said housing to an associated structure comprises a threaded portion, wherein said first abutment means is disposed internally of said housing, wherein said second abutment means is disposed externally on said valve member and slidably received within said housing, said second abutment means comprising a collarlike member including a mounting aperture formed therethrough, said mounting aperture being of a dimension permitting said collarlike member to be pressed onto the outer surface of said valve member and to be forcibly adjustably moved relative thereto.

3. A valve assembly according to claim 1 wherein said means formed at a first end of said housing for detachably securing said housing to an associated structure comprises a threaded portion, wherein said first abutment means is disposed internally of said housing, wherein said second abutment means is disposed externally on said valve member and slidably received within said housing, said second abutment means comprising a collarlike member including a mounting aperture formed therethrough, said mounted aperture being of a dimension permitting said collarlike member to be pressed onto the outer surface of said valve member and to be forcibly adjustably moved relative thereof, said spring means being situated within said housing and operative between said housing and said collarlike member, said spring means being effective to resiliently resist movement of said collarlike member and said valve member in a direction toward said valve orifice and having a resistive force insufi'rcient to cause relative movement between said collarlike member and said valve member when said valve member is moved in a direction toward said valve orifice.

4. A valve assembly according to claim 3 wherein said housing includes a second open end for freely receiving therethrough said valve member and said first means comprises a positive stop means carried by said housing for limiting the travel of said valve member and said collarlike member in a direction away from said valve orifice through the action of said spring means.

5. A valve assembly according to claim 4 wherein said first positive stop means comprises an annular portion carried by said housing internally thereof, said annular portion being positioned as to be in the path of travel of said collarlike member when said valve member and collarlike member are moved in a direction away from said valve orifice.

Claims

3. A valve assembly according to claim 1 wherein said means formed at a first end of said housing for detachably securing said housing to an associated structure comprises a threaded portion, wherein said first abutment means is disposed internally of said housing, wherein said second abutment means is disposed externally on said valve member and slidably received within said housing, said second abutment means comprising a collarlike member including a mounting aperture formed therethrough, said mounted aperture being of a dimension permitting said collarlike member to be pressed onto the outer surface of said valve member and to be forcibly adjustably moved relative thereof, said spring means being situated within said housing and operative between said housing and said collarlike member, said spring means being effective to resiliently resist movement of said collarlike member and said valve member in a direction toward said valve orifice and having a resistive force insufficient to cause relative movement between said collarlike member and said valve member when said valve member is moved in a direction toward said valve orifice.