US2003420A - Fuel pump - Google Patents

Description

June 4, 1935. A; M. BABITCH El AL 2,003,420

FUEL PUMP Filed 0611.26, 1955 2 Sheets-Sheet 1 250212411173 Zabizfb/v June 4, 1935. M, BABlTCH ET AL I 2,003,420

FUEL PUMP Filed Oct. 26, 1933 2 Sheets-Sheet 2 Patented June 4, 1935 UNITED 'STATES PATENT OFFICE FUEL PUMP Abraham M. Babitch and Gordon W. Harry,

Flint, Mich., assignors to A 0 Spark Plug Company, Flint, Mich., a corporation of Michigan Application October 26, 1933. Serial No. 695,314

13 Claims.

contain chambers constituting a variable volume pumping chamber, a receiving, filtering and sediment chamber, suitable valves and an air dome.

Other objects and advantages will be under.- stood from the following description.

The application is in part a continuation of an application of Babitch and Harry for Fuel pump, Serial No. 642,342, filed November 12, 1932.

In the drawings: I

Fig. l is a longitudinal section through the p p- I Fig. 2 is a view on line 2-2 of Fig. 1 with the cover removed and parts in section.

Fig. 3 is an exploded perspective of certain parts. Fig. fl is a longitudinal section'through a modifled form.

Fig. 5 is a section on line 5-5 of Fig. 4. Fig. 6 is a section on line 6-6 of Fig. 5.

I Fig. 7 is a section on line of Fig. 4.

Referring by reference characters to Figs. 1-3

' inclusive, numeral 5 is the upper body member and 1 is the lower member, these two members preferably formed by die casting. -Parts 5 and I. are secured together by fastening means 9, and clamp between them the peripheral portion of a gasoline impervious diaphragm The diaphragm is secured at its center to "a pumpstem |3'by means of discs l5 and IT and a nut l9 threaded to the stem.

The upper part 5 is recessed to form a variable volume pump chamber between the diaphragm H and a partition 2|. Above the partition the body 5 is formed into another chamber 23 which is segmental in shape, being closed by a radial wall 25 extending from a central boss2'l to the periphery.- From the central boss there is also a radial extension constituting a conduit 29 which merely extends through the segmental chamber 23 but does not close it. An opening 3| 'in the wall of body 5 communicates with the chamber 23. A screen 33 engages a shoulder on the top of the peripheral part of body 5 and is held in place in the following manner. A ring 35 is located above the peripheral part of the screen as shown. A cover 31 is supported above the ring 35 and overlies its edge. An apertured cap 39 is threaded at its lower end into the central boss 21 and holds the cover in position. At the upper end of the cap 39 is a cup 4| constitutin an air dome. The screen, near its center, is seated on a shoulder of the central boss. The radial wall 25 has a passage extending therethrough from a point above the screen to the pumpcham- 5 her. Within the passage is a spring 43 seated on a shoulder 45 and pressing upwardly .on a disc valve 41. which engages a valve seat constituted by the lower end of a hollow threaded plug 49. The fluid from opening 3| enters the chaml0- .ber 23, is freed from foreign matter by the screen,

flows through the hollow plug 49, passes the valve 41, and enters the pump chamber. This flow of fluid is produced by the suction stroke of thepump. Foreign matter which collects in the seg- 15 mental chamber 23 beneath the screen 33 may be removed by a valve member 34.

The central boss isapertured as shown and Y carries a valve seat 5|. The valve seat 5| is engaged by a valve 53 normally held to its seat by 20 any suitable resilient means such as 55. The

resilient means 55 engages a seat 56 held down by a spring 58. From the central boss an opening above the valve53 permits the flow of fluid through the passage in part 29. From this out- 25 let any suitable conduit may be provided to deliver the fuel to the carburetor of the. engine. j- The outflow of fluid is produced by the discharge stroke of the diaphragm.

The cam 51. which is on an engine cam shaft 59, operates to pushupwardly on a rod 6|. Rod 6| engages a lever 63 which preferably may be of laminated form as shown. The lever 63 is pivoted at 65 to the pump housing. A spring 61 in abutment with a housing wall 69 engages the lever 63 and operates to hold the end of the rod 6| in contact with the lever and cam. It is through this partition 69 that the pump stem l3 extends. ,The lever 63 has a lug 10 which may engage a pin 1| extending between the arms 13 v of a second lever 15 also pivoted to the pump casing at 11. The outer end'of lever 15 has a known form of interlocking connection with the pump stem l3 whereby theassembly of these parts may be conveniently made.

. By the construction described an upward movement of rod 6| produced by the cam rocks the lever 63 clockwise and when the lug 10 engages the pin H the lever 15 is rocked counterclockwise and the plunger and diaphragm execute a suction stroke. In this way the fuel is drawn into the pump chamber from the reservoir through the inlet valve 41. The discharge stroke is made by a spring 19. This spring is in abutment with the partition 69 and the diaphragm disc l5. The

pump therefore has a variable stroke depending upon the built-up pressure in the pump chamber and the strength of spring 19. When the built-up pressure in the pump chamber, resulting from a relatively small consumption of fuel, overcomes the spring 19, the lever 15 assumes a position such that its pin H is engaged .by the lug 10 of lever 63 only at the latter part of the stroke of lever 63. The pump therefore has a variable stroke to supply fuel in accordance with the demands of the engine without the provision of means for bypassing or overflow.

This pump has special utility in those installations where rotation of the cam is such that a rod reciprocated thereby moves in a direction the opposite of that required by the diaphragm in making the suction stroke. The use of the two levers 63and 15 constitutes a very simple means whereby the necessary operation is effected. It will be understood that the lost motion present in this pump takes place between the ing 10 and the pin 1I.

Referring now to the modified form shown by Figs. 4-7 inclusive, numeral I05 is the upper body member and I 01 the lower member. Parts I05 and I01 are secured together by fastening means I09 and clamp between them the diaphragm H I. Pump stems I I3 and discs I I5 and I I1 correspond in a general way to parts I3, I5, and I1 in Fig. 1. In this modification in place of nut I9 the end of stem H3 is headed as at II9 to hold the parts assembled.

The upper part I05 is recessed forming a pump chamber between the diaphragm III and the wall I2I which in this form is shown as a part separable from the die. cast member I05. This part I 2| may be secured by fastening. means I20. Above the wall I2I the body I05 is formed into another chamber I23 which is segmental in shape and closed by a radial wall I25 extending from a hollow boss I21, the axis of which is somewhat oiTset from the axis of the bodyI05. The radial wall extends to the periphery as shown. From boss I21 is a second radial extension constituting a conduit I 29. This conduit extends through but does not close the chamber I23. An opening I3I in the wall of body I05 communicates with cham-v ber I23. A screen. I33 engages a shoulder on the top of body I05. A packing ring I35 is located above the peripheral region of the screen. A

cover I31 is supported above ring I35 and overlies its edge. Y

The hollow boss I21 is closed at its upper end and at one side of its axis and in the axis of the body I05 is a screw-threaded opening I28. A fastening bolt I39 engages the cap I31 and is threaded into opening I28 sufliciently. to hold the periphery of the cap firmly against thering I35 as shown by Fig. 4.

The radial wall I 25 has a passage I30 extending axially from the region above the screen to the pump chamber. Within this passage is a plug I49 serving as a seat for a valve I41 held upwardly by a spring I43 supported by an abutment I45 carried by the wall I2 I. The fluid from opening I3I enters chamber I23, is freed-from foreign matter by the screen, flows through the passage I30 and passes to the pump chamber through the valve I41. This flow of fluid is produced by the suction stroke of the pump. Foreign matter which collects in chamber I 23 beneath screen I33 may be removed by a plug I34.

Within the hollow chamber of boss I21 is an outlet disc valve I53 normally held to a seat I 5|, provided on wall I2I, by a spring I55 engaging a suitably mounted abutment I56. From the region above this valve I53 is an opening communicating with the outlet passage I29. The space within the boss above the valve I53 serves as an air to the pump member I01'and works against a spring I65 which serves to maintain constant contact with the cam to prevent noise. Also pivoted on pivot I53 is a link I51. The end of link I61 has its end "I bent from the plane thereof and assembled with the pump stem- I I3 by being passed through a slot I13 therefor as shown by Fig. 7. By this arrangement the diaphragm assembly may be positioned to engage the end HI and then rotated to the locked position shown by Fig. 7 prior'to the assembly of the top portion I05. The lever I6I has a shoulder I 15 to engage a part I11 of link. I61 whereby under the action of the cam the lever and link may swing as a unit and pull the stem I I3 and make a suction pump stroke. The discharge is made by a spring I19 supported by the casing member I01 and engaging the diaphragm plate I I5.

The operation of the pump will be understood without further explanation. An important feature is the upper body part which is recessed to form with the diaphragm a pump chamber; which carries the valves; which is formed to provide a receiving, filtering and sediment collecting chamber; and which is provided with a self-contained air dome.

We claim: I

1. In a pump, a casing member provided with a recess, a movable pumping member cooperating with said recess to form a variable'volume pumping chamber, said casing member also recessed to form a receiving chamber, said casing wall having an opening to said receiving chamber, a filter dividing said chamber into first and second parts, an axially extending boss in the flrst part of said receiving chamber, a radial wall extending from said boss to the peripheral wall of said casing, said boss and wall breaking the circular continuity of said first part of said receiving chamber, inlet and outlet valves in said casing member and communicating with said pumping chamber, said outlet valve being in said boss, said boss above said outlet valve constituting an air dome, said radial wall having an axial passage communicating with the second part of the receiving chamber and with the pumping chamber by way of said inlet valve, said casing having radial conduit means extending to the wall thereof from a part of the boss above the valve.

2. The invention defined by claim 1, said axial boss having its axis coincident with the axis of said casing member.

3. The invention defined by claim 1, said axial boss having its axis displaced from the axis of said casing member and closed at its end remote from the pumping chamber, a cap for the casing member forming the closure for the second part of the receiving chamber. y

4. The invention defined by claim 1, said axial bosshaving its axis displaced from the axis of said F casing member and closed at its end remote from said pumping chamber, a cap for the casing member forming a closure for the second part of the receiving chamber, and fastening means holding the cap on said'casing, said fastening means located in the axis of said casing and secured in the closed end of said boss.

5. In a pump, a casing member, a movable element, said member and element forming a pumping chamber, said member also formed to constitute a reservoir, a wall extending radially within said reservoir and terminating in a. boss at a part of the wall removed from the casing periphery, an inlet valve controlling communication between said reservoir and pumping chamber, an outlet valve controlling fluid flow from the pumping chamber, said valves being located in said radial wall, the outlet valve being in said boss, means forming an air dome above a other casing member having a delivery passage from a position above said outlet valve, the radial said outlet valve to produce discharge at a uniform rate of flow, and a cap for said casing member forming a closure for said reservoir.

6. In a pump, a casing member provided with a recess, a movable member cooperating with said recess to form a variable volume pumping chamber, said casing member also recessed to 7. In a pump, a hollow casing member, a partition, mechanism forming a pump below said partition, a central boss in said casing member above the partition, inlet and outlet valves for said pump, the inlet valve forming a communication between the space above the partition and the pump, one of said valves being in said boss, 9. cover ior said casing member, an air I dome element engaging saidcover and threaded into said central boss, said air dome communicating with ,the space above said last-named valve. I 8. The invention defined by claim 7 togethe with a second casing member secured to and below said hollow casing member, a pump diaphragm between said casing members, means in said second casing member to operate said diaphragm, and means to secure said casing members together and peripherally clamp said diaphragm.

9. In a pump, cooperating casing members and a diaphragm clamped between said members, pump operating means in one of said casing members, a partition with a central boss in the other casing member, the partition and diaphragm constituting a variable volume pumping chamber, inlet and outlet valves for said pumping chamber, the outlet valve being in said central boss, a cover for said other casing member, a screen peripherally clamped between said other casing member and cover, an air dome member including an air dome 'to produce continuous flow threaded into said boss over said outlet valve and operable to hold said cover and screen in position. I

10. In a pump, cooperating casing members and a diaphragm clamped'between said members, pump. operating means in one of said casing members, a partition in the other casing member, the partition'and diaphragm forminga variable volume pumping chamber, a radial-wall above the partition forming a segmental reservoir, inlet and outlet valves in said wall, one valve being in the center of the casing, a cover for said reservoir, a screen clamped between the casing member and cover, an air dome element to produce a continuous flow secured to the wall above said outlet valve and serving to hold said cover and screen in position.

11 The invention defined by claim 10, said wall having a passage from the region above the screen to the pumping chamber below the partition, the inlet valve being in said passage, said other casing member having a fluid admitting opening to the region below the screen.

12. In a pump, a casing member, a movable pump member, means to move said movable pump member, said member recessed at one end to form a pumping chamber for said movable pump member, said casing having a transverse wall closing said recess, a radial wall in said casing member above said transverse wall and forming an arcuate receiving chamber, said casing having an opening communicating with said receiving chamber, said radial wall having a hollow, tubular boss at the end of the wall removed from the periphery of the casing, said radial wall also having a passage parallel with the tube of said boss, inlet and outlet valves in said passage and'tubular boss respectively, filtering means in said receiving chamber forming therein an upper region for clean fluid, said parallel passage arranged to provide communication from said upper region to said pumping chamber, and conduit means for the discharge of fuel from said boss above said outlet valve, said hollow boss having an upper end closure to form an air dome above the outlet valve.

-18. In a pump, a casing member,v a movable pump member, means to move said movable pump member. said member recessed at one end to form a pumping chamber for said movable pump member, said casing having a transverse gion for clean fluid, said parallel passage arranged to provide communication from said upper region to said pumping chamber, and' conduit meansfor the discharge of fuel from said boss above said outlet valve, said hollow boss be-' ing integrally closed at its upper end to form an air dome above the outlet valve.

' ABRAHAM M. BABITCH.

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