US2529204A - Fuel pump - Google Patents

Description

NOV- 7 1950 c. w. VAN RANsT E'rAL 2,529,204

FUEL. PUMP Filed June '7, 1946 Patented Nov. 7, 1950 UNITED STATES YPATENT OFFICE FUEL PUMP Cornelius W. Van Ranst and Ward D. Smith, Dearborn,.Mich.; said Smith assignor, by mesne assignments, to said Van Ranst Application June 7, 1946, Serial No. 675,113 8 Claims. (Cl. 10S-#150) The present invention relates -generally to internal combustion engines and it has particular relation to a fuel pump.

Fuelpumps employing pulsating diaphragmsare generally used in motor vehicles for the purpose of supplying fuel to the carburetor. These pumps are operated, as a rule, by cam means on the engine cam shaft, and the present invention is concerned with a fuel pump of this general character.

One object of the present invention is to provide an improved fuel pump of the above generally indicated type employing a pulsating diaphragm, which is simple in construction, economn ical of manufacture and assembly, and which is reliable and eiiicient in operation.

It is also an object of this invention to provide a fuel pump having an improved and highly durable diaphragm, and improved means mounting'the diaphragm in the pump.

Another object of this invention is to provide a fuel pump having improved means for pulsa-- ting the diaphragm thereof.

Another object of the present invention is' to provide a fuel pump having improved means by which the extent of movement of the diaphragm is varied in response to the fuel pressure within the pump and in which the fuel pressure acts to limit the engagement between the engine cam shaft and the fuel pump bell crank operated thereby.

A further object of this invention is to provide a fuel pump having an improved casing construction eliminating the need for a cover and securing means therefor.

It is also an object of this invention to provide a fuel pump having an improved construction which eliminates the possibility of accidental disassembly of the diaphragm pulsating means as a result of the vibration and jarring incurred in normal operation. Y

Other objects of the invention will become apparent from the following specification, the drawings related thereto, and the claims hereinafter set forth.

For a better understanding of the invention reference may be had to the drawings wherein:

Figure l is a sectional view of a'fuel pump constructed according to one form of the invention;

Figure 2 is a reduced sectional view of the structure shown in Figure 1 taken substantially along the line 2-2 thereof;

Figure 3 is a reduced fragmentary sectional view of the structure of Figure 1 taken substantially along the line 3-3vthereof; `and l 2 Figure 4 'is a reduced plan View of the structure shown in Figure l.

Referring to the drawings, the fuel pump comprises a casing having a lower part Ill and an upper part I I having flanges I2 and I 3 respectively formed thereon and fastened together lloy screws I4. The casing thus provided isdivided by a diaphragm V'I5 having a marginal portion I6 having an enlarged anchoring bead I'I integrally formed on its periphery. The marginal portion I6 and bead I'I are received in a complementary recess I8 formed in the flange I2 of the lower part of the casing. The marginal portion I6 is slightly thicker than the central portion of the diaphragm and thicker than the depth of the recess I8 in which it is received, such that prior to assembly it extends a little above the upwardly presenting face of the flange I2. y v

When the pump is assembled, the marginal portion is compressed into the recess I8 by the marginal portion I9 of a metal disk 20, the construction and function of which will be hereinafter described. The engagement of the bead I'I in the recess I8 serves to locate the diaphragm.I This construction provides a metal to metal con;` tact, outwardly of the diaphragm, between'the marginal portion I9 of the disk and the ange I2 of the lower part of the casing. This contact limits the clamping force which may be applied to the marginal portion of the diaphragm' and thereby prevents excessive flattening and hence weakening thereof. For this reason, this con' struction prevents careless workers from im-` properly assembling the pump by applying too great a pressure to the diaphragm. The thick? ness of the marginal portion of the diaphragm and the depth of the recess I8 in which it is received, are such that when the diaphragm is clamped in position, the thickness of marginal portion remains at least as great as that ofthe central portion of the diaphragm.

An annular sealing bead 2I is formed on the upper surface of the marginal portion of the diaphragm and is received in a groove formed-in the lower surface of the disk 2l), to provide a seal at the lower side of the disk. For providing a seal at the upper side of the disk, a gasket 22 is disposed between the marginal portion of the disk and the flange I3 on the upper part of the casing.

The diaphragmA is constructed of suitable material such as synthetic rubber having high resistance to the action of hydrocarbon fuel Vand it is flexible so that it may be moved relative to its marginal portion. At its center the diaphragm is held between two disks 24 and 26 which are connected at their centers by a pin 28.

During operation of the pump the diaphragm moves upwardly and downwardly or in other words, pulsates. This movement is imparted to the diaphragm I5 through a U-shaped bracket the base of which is securely held against the lower surface of the disk.-24 by the pin 28 which extends through an 'aperture in the bracket 30 and has a shoulder 32 which engages the bracket. A bell crank 34 is pivotally mounted on the lower part I0 of the casing by a pin 3B and has its inner end 38 bifurcated and pivotally connected to the depending arms of .the U- shaped bracket 30hy rivets 40. .The outerend v of the bell crank 34 extends upwardly from'- its pivotal connection to the casing and isv adapted to engage a cam 44 formed on the engine cam shaft 46.

A spring 48 is disposed between the depending arms of the bracket `3E] :andbetweenthe bifurcated ends 38 of the bell crank 34 andnormally urges-the diaphragm upwardly andthe bellcrank in a clockwise direction as Viewed in Figure 1. The upper end-of the spring 48 encircles thepin 28 and engages .thebasetof the bracket 30, andrits lowerv end engages-the wall ofthev lower part I0 of the casing and is held in .position by Y,an .annular boss 50 integrally formed thereon..andwhich it encircles.

The .lower .part |0.of the casing has a 4base portion 52 adapted to engage and be secured to engine block 54, .and carrying a sealing ring 56 .which engages -said engine-block to forma tight Aseal between the engine block and the base. For securing the fuel pump to the engine, the base portion -52 is provided with apertures 58 adapted to receive studs -68 .mounted in the engine block. One-.of these apertures-.58 is disposedso -that its aX-is. intersectsthe axis. of the pin 36 withthe result that when the base. portion 52 is'mounted on the engineblock 54,.the nut y6I receivedon the stud limits the movement flthe -pin inone direction. .For limiting -movement -ofv the pinin the opposite direction a slightly enlarged head` 82 is integrally formed thereon. WhenV the, pin is assembled,.the headis dis-posed to engage vthe nut 6| to limit .movementoutwardly and to .engage the vcasingto limitmovementinwardly. This construction prohibitsremoval vof the ypin Y36 while `thefuel .pump is mountedion the engine .and therefore eliminates all Ypossibility rof the pin- 36 fallingout kas the result of the Vibration or .jarring .incidentto operationof the engine.

The-.upper part II of the vcasing includes van inner cylindrical wall 66 and an outer cylindrical wall68. The inner wall 66 divides the upper part II into an inner vapor and fuel chamber 'maand .an outer vapor and fuelchamber 12. An inlet connection II opens into the inner chamber 10, and theI outer chamber 'I2 is provided with an outlet'connection 13 through which the pump supplies, fuelto the carburetor.

A circular plate or valve seat 74 has an annular projection 'I6 on one side thereof which carries asealing ring v'I8 and is received inthe lower end of the inner cylindrical wall 66 with which it has a pressfiit. Inwardlyf of the` pro'- jection I6 the plate 'I4 has a second annularprojection80 formed thereonwhich co-operates with a-similar projection-82, formed on the'u-pper par-t Ilot-.the casing, inwardly of-.the inner wall 66, to position and support a screen84 disposed Y within the inner vapor and l fuel chamber `v'|0.

Internally of the projection the plate 'I4 is provided with a plurality of openings 86 for allowing the flow of fuel froml one chamber to the other.

The disk 20 is mounted between the flanges I2 and I3, as described above, and extends across the casing. Its central portion is upwardly7 oiTseta-nd isproyided with a -large central opening 94 `,and smaller marginal openings 96. At its upper side, the disk 20 has an annular rib *98 located between the opening 94 and the marginal openings 96. mfor a disk-like rubber valve |00 which has an .annular downwardly opening channel portion |02 This rib serves as an anchor fitting therib and also sealing against the valve seat 14, outwardly of openings 86. The valve |00 has an opening |04 at its center and around this opening it' has an upwardly extending annular sealing bead |06 adapted to engage the under side of the valve seat 14, inwardly of openings-86. `Outwardly of the channel: |02, the Valve I00has a similar :annular bead |08 on its under side which is adapted to engagethe Vdisk20 outwardlyof-the openings 96. The valve`|00 may be composed .of any of the synthetic rubbers which` areresilient and iiexible--and highly resistant to the acti-on of hydrocarbon fuel as well as resistant to corrosion.

During the operation ofthe pump, the downward movement of the diaphragm I5 causes the central portion of ythe-resilient valve |00 to be flexed downwardly unseating the sealing bead |06 from thevalve seat 14 and causing'fuel to flow into the inner fuel and vapor vchamber l0 through the -inlet opening 'II and-then downwardly through the openings 86 in the valve seat, the central opening |04 in the valve, andthrough the opening 94 -to-thelower'side Iof the metal disk `20. vDuring this vmovement of the diaphragm, the sealing bead |08 is held firmly against the disk 20 to close the openings 96 therein. Upon upward s movementY of the diaphragm I5, the sealing `bead |06 -seats y'against the valve seat 'I4 .and closes the openings 86, while the outer marginal portion of the yvalve |00 is iiexed upwardly unseating thesealingbead |08 from the disk 20and uncovering the openings 96. During this upward-movement of the diaphragm, fuel flows upwardly through the-"openings 96 into vthe outer Vapor andffuel chamber 'I2 and to the carburetor through the outlet connection 13. .The resiliency of the valve |00 causesthe sealing beads |06 and |08 to'return to theirsealing position 'in which they engage the valve seat 'I4 and the disk V2!) respectively, at all times lwhen they vare not unseated` by the action of the diaphragm I5.

Although l'onlyone specific embodiment of the inventionhas been illustrated and described in detail, it will *ne-apparent to those skilled in the art that various modifications and changes maybe made without departing from'the'spirit of the invention .andV from'the scope ofthe'appended'claims.

` What is claimed is:

1. In a fuel pump, a casing, means'including valves dening van'. inlet chamber and an outlet chamber, a'diaphragm operable to pump fuel through said chambers, means .for Apulsating said dia-phragmaid last' named means being'responsive to variations' inthe fuel pressure within said chambers to vary the extent of movement of said diaphragm and 'including a'depending "element connected to said diaphragmgabell crank pivotally mounted lon-said 'casing having'ione end" pivotally connected to said element and the other end adapted to engage a cam, and spring means urging said bellcrank into engagement with said cam, said last named means being responsive to said variations in the fuel pressure within said chambers to vary the contact between said other end of said bell crank and said cam and thereby to vary the stroke of said diaphragm.

2. In a fuel pump, a casing, means including valves defining an inlet chamber and an outlet chamber, a diaphragm operable to pump fuel through said chambers, means for pulsating said diaphragm including a depending element connected to said diaphragm, a bell crank pivotally mounted on said casing and having one end pivotally connected to said element and its other end adapted to engage a rotary cam, and a spring biasing said other end of said bell crank toward said cam, said last named means being responsive to variations in the fuel pressure in said chambers to vary the extent of movement of said diaphragm by varying the Contact between said cam and said bell crank.

3. In a, fuel pump, a casing, means including valves defining an inlet chamber and an outlet chamber, a diaphragm operable to pump fuel through said chambers, means for pulsating said diaphragm including a U-shaped bracket connected to said diaphragm, a bell crank pivotalli7 mounted on said casing and having one end bifurcated and pivotally connected to said U- shaped bracket and its other end adapted to engage a rotary cam, and a spring disposed between the arms of said U-shaped bracket and engaging said bracket at one end and said casing at the other end to bias said other end of said bell crank toward said cam, said last named means being responsive to variations in the fuel pressure in said chambers to vary the extent of movement of said diaphragm by varying the contact between said cam and said bell crank.

4. In a fuel pump, a casing comprising an upper part and a, lower part, said upper part comprising a cup-shaped lelement having inner and outer downwardly extending Walls integrally formed thereon, a valve seat plate mounted in the lower end of the inner of said walls and extending across the opening at the lower end of said inner wall, 9, diaphragm extending across said casing between said parts, means including valves dividing said upper part into an inlet chamber and an outlet chamber, and means for pulsating said diaphragm.

5. In a fuel pump, a sub-assembly comprising a diaphragm, a U-shaped bracket secured to said diaphragm, a bell crank having one end bifurcated and pivotally connected to said bracket and its other end adapted t engage a cam, said bell crank being apertured intermediate its ends for pivotally supporting said bell crank on the casing of said fuel pump.

6. In a fuel pump, a casing, means including valves defining an inlet chamber and an outlet chamber, a diaphragm operable to pump fuel through said chambers, means for pulsating said diaphragm, said last named meansbeing responsive to variations in the fuel pressure at one side of said diaphragm to vary the extent of movement of said diaphragm, said last named means including a bellcrank pivotally mounted on said casing and having one end operatively connected to said diaphragm and the other end adapted to engage a cam, and said last named means being responsive to said variations in said fuel pressure to vary the contact between said other end of said bellerank and said cam to effect said variations in the extent of movement of said diaphragm.

7. In a fuel pump, a casing including an upper member and a lower member, said upper member having integrally formed inner and outer annular wall portions and an upper end wall portion, a valve plate member mounted in the lower end of said inner annular wall portion, a diaphragm extending across said casing between said members, means including valves dividing said upper member into an inlet chamber and an outlet chamber, and means for pulsating said diaphragm to eiTect a pumping action, said upper end wall portion closing both said chambers at their upper ends.

8. In a fuel pump, a casing including an upper member and a lower member, said upper member having integrally formed inner and outer annular wall portions and an upper end wall portion deninga central chamber and an annular chamber surrounding said central chamber, an element disposed within said central chamber for removing foreign substances from fuel passing therethrough, an apertured plate member mounted in the lower end of said inner annular wall portion and supporting said element, a diaphragm extending across said casing between said members, means including valves dividing said upper member into an inlet chamber and an outlet chamber, and means for pulsating said diaphragm to effect a pumping action, said upper end wall portion closing both said chambers at their upper ends.

CORNELIUS W. VAN RANST. WARD D. SMITH. Y

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,852,643 Collins Apr. 5, 1932 1,881,255 Whitacre Oct. 4, 1932 1,893,217 Babitch Jan. 3, 1933 1,903,481 Schweisthal Apr. 11, 1933 1,905,207 Babitch et al. Apr. 25, 1933 1,912,659 Schweisthal June 6, 1933 1,965,497 Johnson July 3, 1934 1,980,091 Rockwell Nov. 6, 1934 2,003,420 Babitch et al. June 4, 1935 2,016,580 Schulze et al. Oct. 8, 1935 2,036,452 Babitch et al. Apr. 7, 1936 2,266,297 Babitch et al. Dec. 16, 1941 2,426,965 Coffey Sept. 2, 1947

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