US3238967A - Insertable check valve unit - Google Patents

Description

March 8, 1966 R. F. SMITH INSERTABLECHECK VALVE UNIT 2 Sheets-Sheet 1 Original Filed Jan. 26, 1962 INVENTOR RUSSELL F. SMITH AGENT March 8, 1966 R. F. SMITH INSERTABLECHECK VALVE UNIT 2 Sheets-Sheet 2 Original Filed Jan. 26, 1962 INVENTOR RUSSELL F. SMITH AGENT United States Patent M 3,238,967 INSERTABLE CHECK VALVE UNIT Russell F. Smith, Ferguson, Mo., assignor to ACF Industries, Incorporated, New York, N.Y., a corporation of New Jersey Original application .ian. 26, 1962, Ser. No. 169,012, new Patent No. 3,198,128, dated Aug. 3, 1965. Divided and this application Apr. 24, 1964, Ser No. 362,279 1 Claim. (Ci. 137516.21)

This invention relates to pumps, and more particularly to a diaphragm pump of a type especially suitable for pumping automotive fuel to the carburetor for an internal combustion engine, the diaphragm of the pump being operable by a drive from the engine.

This application is a division of my copending application Serial No. 169,012, filed January 26, 1962, now Patent No. 3,198,128, which in turn is a continuation-inpart of the copending application Serial No. 122,025, filed July 5, 1961, now Patent No. 3,150,601.

One of the problems occurring with conventional diaphragm fuel pumps is the problem of vaporization of fuel in the pump, with the attendant possibility of interruption of flow of fuel to the carburetor, this being customarily referred to as vapor lock. It will be understood that the fuel is highly volatile, having a tendency to pass from the liquid to the vapor state, which tendency is, of course, increased by heating. Since the fuel pump is conventionally mounted on the engine to be driven thereby, heat is transferred from the engine to the pump, and thereby to fuel in the pump. Unless this heat is effectively dissipated, vapor lock may occur due to vaporization of fuel in the pump.

Accordingly, one of the objects of this invention is the provision of a pump which, while being of simple, economical construction, is adapted effectively to dissipate heat from the pump so as effectively to reduce the tendency for volatilization of fuel in the pump, thereby to reduce the possibility of vapor lock. In general, this is accomplished by utilizing a pump body of thin-walled heat-conductive construction such as to provide for transfer of heat outward through the wall of the body at such a rate as substantially to reduce the tendency for volatilzation of fuel within the body. The pump body is formed to provide a pumping chamber and an intake cavity and a discharge body, and the pump includes a diaphragm closing the pumping chamber, an intake check valve in the intake cavity and a discharge check valve in the discharge cavity. With the body of thin-walled heat-conductive construction, heat is effectively dissipated from the pumping chamber and from the intake and discharge cavities, thereby maintaining fuel in the pump in a relatively cool state to reduce the tendency toward volatilization such as would otherwise be present. The pump body may be formed of relatively thin sheet metal, which provides for a simple economical construction while at the same time providing for effective heat dissipation. Additionally, the outside surface of the body may be made heat-reflective to decrease the absorption of heat by the body from ambient temperatures.

Further objects of the invention are the provision of means in the discharge cavity or in both the discharge and intake cavities for damping pulsations in the pressure of fuel delivered by the pump, so as to maintain a more uniform rate of delivery of fuel to the carburetor, and the provision of an improved check valve construction such as to avoid distortion of the check valves when they are assembled with the pump body, thereby to maintain the accuracy of the seats of the check valves. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions Patented Mar. 8, lfifih hereinafter described, the scope of the invention being indicated in the following claim.

In the accompanying drawings, in which several of various possible embodiments of the invention are illustrated:

FIGURE 1 is a view in elevation illustrating a diaphragm pump of this invention in use on the engine of an automotive vehicle for pumping fuel from the fuel tank of the vehicle to the carburetor for the engine, the pump being of a type that may be referred to as an inverted pump;

FIGURE 2 is a vertical section of the pump shown in FIGURE 1;

FIGURE 3 is a bottom plan of FIGURE 2;

FIGURE 4 is an enlarged vertical cross section of a check valve used in the pump;

FIGURE 5 is a bottom plan of the FIGURE 4 check valve;

FIGURE 6 is a fragmentary vertical cross section of a pump similar to the FIGURE 2 and including a first type of pulsationdamping means;

FIGURE 7 is a fragmentary vertical cross sectional similar to FIGURE 6 illustrating a second type of pulsation-damping means and also illustrating certain modifications in the pump construction;

FXGURE 8 is a half-section in perspective of a modified version of the pulsation-damping means of FIGURE 7; and

FIGURE 9 is a fragmentary vertical cross section similar to FIGURE 2 illustrating another type of pulsationdamping means and also illustrating certain modifications in the pump construction.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to FIGURE 1 of the drawings, there is indicated at A an automotive vehicle having an engine E on which is mounted a fuel pump P of this invention. Fuel is delivered from fuel tank T of the vehicle through a line L1 to the fuel pump P and delivered by the latter through a line L2 to the carburetor C for the engine. The carburetor is mounted on the intake manifold of the engine, and an air filter F is shown mounted on the air horn of the carburetor.

As appears in FIGURE 1-3, pump P is a so-called inverted pump, i.e., its inlet and outlet are located at the bottom of the pump. As shown in detail in FIGURES 2 and 3, pump P comprises a rocker arm housing 1 which is open at one end (its left end as appears in FIGURE 2), this end being referred to as the inner end of the housing. This housing is of generally rectangular form in vertical cross section and of decreasing height from its inner end to its outer end (which is closed). At its inner end it has aflange 3 for attaching it to the engine E. A rocker arm 5 is pivoted at 7 in the housing for rocking motion on a horizontal axis transverse to the housing. Arm 5 has aportion 5a projecting out of the open inner end of the housing, and is biased to rock clockwise as viewed in FIGURE 2 by a spring 9. When the pump is mounted on the engine, thefree end portion 5a of the rocker arm is engaged by an engine-driven eccentric or cam 11. On rotation of the cam through half a revolution from its FIGURE 2 position (wherein the low point of the cam engagesportion 5a of the rocker arm), the rocker arm is rocked counterclockwise from its FIGURE 2 position against the bias of spring 9. The latter is adapted to return the arm clockwise during the succeeding half-revolution of the cam.

Extending downward from the rocker arm housing 1 at its outer end is a hollowconical pump head 13. Anopening 15 is provided between the interior of housing 1 and the hollow head T3 at the top of the latter. The conical head has an outwardly projecting comparatively thickflat flange 17 at the bottom. The bottom of this flange constitutes a seating surface for the margin of anannular diaphragm 19 consisting of a relatively thick disk of flexible fuel-resistant material, such as a suitable synthetic rubber, which when in unstressed condition, is flat or substantially flat. The outer margin of the diaphragm is clamped against the bottom offlange 17 by apump body 21 which, as illustrated in FIGURE 2, is of one-piece thin-walled sheet metal construction, formed of shallow cup shape, having a bottom orend wall 23 and a flaring, rounded annularperipheral wall 25 defining apumping chamber 26, with an outwardly extending annularflat flange 27 at the top ofwall 25, and acylindric rim 29. Thebody 21 is maintained in assembly withhead 13 by spinning therim 29 over onflange 17 of the head as indicated at 31, with the margin of the diaphragm clamped betweenfiange 17 andflange 27 under suflicient pressure to provide a fuel-tight seal all around the margin of the diaphragm.

The diaphragm is adapted to be pulled or flexed upward by a diaphragm-actuatingrod 33 and to be flexed downward by aspring 35. Rod 33 extends upward throughhead 13 and through the opening 15 at the top of the head into the rocker arm housing 1. The rocker arm 5 has aslot 37 at its end in housing 1 receiving therod 33. The latter has acollar 39 at its upper end engageable by this end of the arm 5. The rod extends slidably through an oil seal and rod guide 41 held in an annular recess at the top of thehead 13 by the reaction on aseal retainer ring 43 of thespring 35, this spring being a coil compression spring surrounding the rod. The diaphragm is mounted on the lower end of therod 33 between a pair ofcircular plates 45 and 47,plate 45 being the upper plate andplate 47 the lower plate. The upper plate is formed with an annular corrugation orrib 49 forming a seat for confining the lower end ofspring 35. The upper plate is of larger diameter than the lower plate and the margin of the upper plate which overhangs the lower plate is flared outward and downward to provide arim 51 constraining the diaphragm to have an annular, free,nonreversing loop 53. The lower plate has acurved rim 55 engaging the loop. In the downward position of the diaphragm illustrated in FIGURE 2, the outside of the loop engages therounded flaring wall 25 of thepump body 21. When arm 5 is rocked counterclockwise by cam 11, it lifts the rod and pulls the diaphragm upward. This loads thespring 35. Then when arm 5 rocks clockwise,spring 35 is adapted to drive the diaphragm and rod downward.

The sheetmetal pump body 27 is formed with two integral deepdrawn rounded-bottom cylindricalcupshaped projections 57 and 59 extending downward from thebottom wall 23 ofbody 21 on opposite sides of the center of the bottom wall.Projection 57 defines an inlet passage orintake cavity 61 andprojection 59 defines an outlet passage ordischarge cavity 63. Aninlet nipple 65 is provided at the lower end ofprojection 57, and anoutlet nipple 67 is provided at the lower end ofprojection 59. In FIGURE 2,inlet nipple 65 is shown as a straight nipple, andoutlet nipple 67 is shown as an elbow nipple. It will be understood that, in the installation shown in FIGURE 1, supply line L1 is connected toinlet nipple 65 and discharge line L2 is connected tooutlet nipple 67.

Thenipples 65 and 67 are fixed to therespective deepdrawn projections 57 and 59 by inserting the respective collared ends 66 and 68 into a central aperture in the bottom of therespective projections 57 and 59 and swaging the metal of the projections tightly against the nipple ends, as shown to form a fuel tight seal. The collared nipple ends 66 and 68 each have grooves formed in the surface of the collars so that the swaged metal is pressed into the grooves to prevent a rotation displacement of the nipples. The sheet metal construction of the pump thus lends itself to a universal adjustment of thenipple 67, for

example, in 360 to accommodate any required directional departure of the inlet fuel line L2. In asimilar manner nipple 65 may also be formed with an elbow to accommodate any directional approach of inlet line L1. This universal adjustability of thenipples 65 and 67 provides a flexibility of use with different engine arrangements, which is not available in pumps fabricated from castings.

Anintake check valve 69 is provided in theintake cavity 61 and adischarge check valve 71 is provided in thedischarge cavity 63.Nipple 65 provides for connection of supply line L1 tointake cavity 61 upstream from theintake check valve 69 andnipple 67 provides for connection of discharge line L2 to dischargecavity 63 downstream from thedischarge check valve 71. These check valves are of identical construction. As shown in FIGURES 4 and 5, each check valve comprises a circular sheetmetal valve seat 73 having acylindric rim 75 sized for a press fit in eithercavity 61 orcavity 63, as the case may be.Seat 73 has acentral hole 77 with anannular boss 79 around the hole extending in the same direction as therim 75. Surrounding the central hole is a series ofports 81 arranged in a circle around the center hole. The dimension of each of these ports as measured along the stated circle is less than the distance measured radially of theseat 73 from the periphery of thecenter hole 77 to the periphery of theseat 73. More particularly, the ports are circular holes of smaller diameter than the center hole. The are equally and closely spaced around the stated circle at intervals such as to leavespokelike portions 82 of thevalve seat 73 between the ports with these spokelike portions narrower than the diameter of the ports.Seat 73 is preferably dished inwardly to a slight extent in the direction in which rim 75 andboss 79 project therefrom (i.e., downwardly dished as viewed in FIGURE 4). This dishing may be of the order of 1 /2 for example. Fitted in theboss 79 is a hollow sheet metal stem 83 which is closed at its lower end as indicated at 85 in FIGURE 4.Stem 83 has an apertured mushroom head 87 at its other end constituting a spring seat. A ring-shapeddisk valve member 89, which may be made of a suitable fuel-resistant synthetic rubber for cushioned sealing is slidable on the stem and is biased toward engagement with the valve seat by a coil compression spring 91 surrounding the stem and reacting from the head 87. In assembling the stem with the valve seat, thestem 83 is pressed in thecentral hole 77 in the valve seat and the closed end of the stem is deformed as indicated at 93 to lock the stem in the seat and seal the central hole.

Theintake check valve 69 is pressed in theintake cavity 61 with itsstem 83 extending upward and thedischarge check valve 71 is pressed in thedischarge cavity 63 with its stem extending downward (see FIGURE 2). It has been found that, with the ports in the valve seat formed as herein described, rather than being formed as relatively long slots in the valve seat, stresses such as would cause distortion of the valve seats during the operation of pressing the seats into the cavities are avoided, and the original accuracy of the seats is preserved. At the same time, the total port area is adequate for flow of fuel.

In the operation of the pump shown in FIGURE 2,diaphragm 19 is flexed up and down by the action of arm 11 andspring 35. On an upward (suction) stroke of the diaphragm, theintake check valve 69 opens and thedischarge check valve 71 closes, and fuel is drawn into the pumpingchamber 26 below the diaphragm. On a downward (discharge) stroke of the diaphragm, theintake check valve 69 closes and thedischarge check valve 71 opens, and fuel is forced out through line L2 to the carburetor. Since thepump body 21 is formed of sheet metal, it is of thin-walled heat-conductive construction such as to provide for transfer of heat outward there through at such a rate as substantially to reduce the tendency for volatilization of fuel within the body, thereby reducing the possibility of vapor lock. In this respect,

it will be observed that heat transmission occurs not only throughwalls 23 and 25 of pumpingchamber 26 but also through the walls and bottoms ofprojections 57 and 59, all of which are thin-walled, so that heat is dissipated at a relatively rapid rate. The rate may be increased by making the outer surface of the pump body heat-reflective, as by bright zinc plating of the exterior of the pump body. With such plating, heat is reflected from the body for cooler operation of the pump and increased transmission of heat from fuel in the pump body to the exterior.

Making the pump body of sheet metal not only provides a thin-walled construction for effective heat dissipation, but also provides an economical construction, the pump body itself being economical to manufacture and economical to assemble with the rocker arm housing 1, the assembly operation simply involving the spinning over ofrim 29 of the pump body onflange 17 of thehead 13. A typical pump body having a diameter (measured at rim 29) of three and one-half inches may be made of suitable steel plate 0.035 inch thick, for example. In general, the advantages of the invention may be attained with a pump body having a wall thickness less than 0.050 inch.

FIGURE 6 illustrates a pump similar to that shown in FIGURE 2 provided with means for damping pulsations in pressure of fuel delivered by the pump so as to maintain a more uniform rate of delivery of fuel to the carburetor. As shown in FIGURE 6, the cup-shaped projections of thepump body 21 are drawn deeper than in FIGURE 2, and are designated 57a and 59a. In each cup is pressfitted apartition 101 having acentral hole 103 and a circular series ofports 105 around thecentral hole 103. The portion of the partition around the center hole is cupped as indicated at 107 to form a seat for a hollow resilientcompressible ball 109 which may be made, for example, of a suitable fuel-resistant synthetic rubber. In theintake cup 57a the partition is arranged withseat 107 extending upward andball 109 below the partition. In thedischarge cup 59a, the partition is arranged withseat 107 extending downward andball 109 above the partition. The hollow resilientcompressible balls 109 act like air chambers or air domes to damp pulsations of pressure of fuel in the intake and discharge cavities by contraction and expansion thereof, and tend to equalize pressure of fuel delivered to the carburetor.

FIGURE 7 illustrates a modification in which the cupshaped projections of thepump body 21 are constituted by separately formedcup members 57b and 59b. Each of these has an outwardly extending rim 111 at its upper end and extends down through anopening 113 provided in thebottom wall 23 of the pump body, the rims engaging thebottom wall 23 and being suitably soldered thereto. This three-piece type of construction for thepump body 21 has the advantage over the one-piece type of pump body shown in FIGURE 6, for example, in that, for a given cup height, it permits the cups to be arranged closer together, as may be desirable. In this respect, it will be observed that with deep-drawn integral cups as in FIG- URE 6, it is necessary that the cups be relatively widely spaced to permit deep drawing.

FIGURE 7 also illustrates another type of pulsation damping means comprising an annular hollow resilientlycompressible member 121 axially positioned in eachprojection 57b and 59b, each of these members being made, for example, of a suitable fuel-resistant synthetic rubber. Thecentral passages 125 through these members provide for flow of fuel, and pulsations are damped by contraction and expansion of the members, which act like air chambers or air domes.

FIGURE 8 illustrates a modification of the pulsation clamping members of FIGURE 7, showing an annular re silientlycompressible member 121a made of closed-cell foam rubber of a fuel-resistant variety. Such members may be conveniently obtained by segmenting an extruded tube of the closed-cell foam rubber material. They are placed incups 57b and 59b in the same manner asmembers 121 shown in FIGURE 7.

FIGURE 9 illustrates another arrangement for pulsation damping on the discharge side of the pump only. As shown therein, the intake cup, designated 57c, is a relatively short cup (as in FIG. 2), formed as a separate piece and soldered to the pump body as in FIGURE 7. The discharge cup comprises ashell 131 having a cylindricupper end portion 133 received in an opening in thebottom wall 23 ofpump body 21 in the same manner as in FIGURE 7, and a flaringlower portion 135. Thedischarge check valve 71 is pressed into thecylindric portion 133. The flaring lower portion has an outwardly projecting flatannular flange 137 at its lower end constituting a seating surface for a diaphragm 139 made, for example, of a suitable fuel-resistant synthetic rubber. The outer margin of the diaphragm is clamped against the bottom offlange 137 by therim 141 of aninverted dome 143 and the parts are held in assembly by spinning arim 145 onflange 137 over on therim 141 of the dome. The diaphragm 139 and the dome provide anair chamber 147 sealed ofi from theshell 131, pulsations being damped by flexing of the diaphragm. Thedischarge nipple 149 is connected to shell 131 above the diaphragm 139.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

A check valve assembly for a pump having a wall formed with an opening, said valve assembly comprising a sheet metal valve seat having a ported valve seat surface formed with a series of ports arranged in a circle and an outer marginal cylindrical rim generally at right angles from a face of said seat, a central opening formed in said seat defined by a flange extending in the direction of said rim, a valve retainer including a stem snugly fitted within said central opening and extending below said flange and having an enlarged terminal portion below said flange, said stem forming a closure for said central opening, said stem having a spring seat portion at the other end thereof, a disk valve slidably mounted on said stem between said spring seat portion and said valve seat, and a coil spring mounted around said stem between said spring seat portion and said disk valve and biasing said disk valve against said ported valve seat surface.

References Cited by the Examiner UNITED STATES PATENTS 248,902 11/ 1881 Whitman 137-454.2 1,976,464 10/1934 Shallenberg l37543.15 X 2,087,417 8/1937 Peo 137543.15 X 2,531,532 11/1950 Rossman 13752S X 2,777,464 1/ 1957 Mosely 1375 16 2,803,265 8/1957 Coffey 137-543.l5

ISADOR WEIL, Primary Examiner.

WILLIAM F. ODEA, Examiner.

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