US2266585A

US2266585A - Fuel pump

Info

Publication number: US2266585A
Application number: US266257A
Authority: US
Inventors: Christiaan H Bouvy
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-04-06
Filing date: 1939-04-06
Publication date: 1941-12-16
Anticipated expiration: 1958-12-16

Description

Dec.16, l1941.` c, H, BoUvY FUEL PUMP Filed April e, i959 2 Sheets-Sheet 1 l IMI Tm/afar una Derc. 16, 1941. c. H. BoUvY 2,266,585

FUEL PUMP A Filed Apri] 6, 1959 2 Sheets-SheefI 2 NVENTOR.

f/5M #15mg BY 75W @uw @QMMWYMQ ATTORNEYs Patented Dec. 16, 1941 f UNITEDY STATES PATENT OFFICE FUEL PUMP Christiaan H. Bouvy, Detroit, Mich.

Application April 6, 1939, Serial N0. 266,257

(Cl. 10B-152) 6 Claims.

This invention relates to a fuel pump and has particularly to do with a fuel pump for internal combustion engines.

In the past it has been common to provide vacuum operated fuel pumps in which two pumping members are interconnected and it has been common to provide snap action connections between the control valves and the pumping members to control pressure or vacuum to the pumping members. The present invention contemplates a fuel pump which is self-contained in that no mechanical connection -is necessary between the pump and an operating part of the engine. The pump of the present invention is to be operated by differential pressures, one of the pressures being atmospheric and the other being sub-atmospheric. However, if found desirable the range of the pressure differential can be changed, one pressure being atmospheric and the other above atmospheric.

A further object of the invention has 1to do with provision of a pump which will furnish a supply of fuel to an engine, as required at a limited maximum pressure. An additional object has to do with the provision of a fuel pump in which the two pumping elements operate independently of .each other as far as mechanical connection is concerned.

It is a further object of the invention to provide a fluid-operated fuel pump with a simplified valve structure. The vacuumA operated pump has the advantage that it can be mounted outside of the engine compartment in a cool location so as to avoid trouble from vapor locking. Also, the feed line to the fuel pump, which is under sub-atmospheric pressure, is not exposed to the heat in the engine compartment, as is the case with a mechanical operated pump mounted on the engine.

Other features and objects of the invention having to do with details of construction and operation, as, for example, the arrangement of ports in the valve-cylinder structure, will be further brought out in the following description and claims.

In the drawings:

Fig. 1 is a horizontal longitudinal section taken through a fuel pump constructed in accordance with the present invention.

Fig. 2 is a vertical section of the invention Y taken on lines 2--2 of Fig. 1. Section lines I-I of Fig. 2 refers to the section of Fig. 1.

Fig. 3 is a transverse section taken on the lines 3-3 of Fig. 2.

Fig. 4 is a diagrammatic presentation of the pump for purposes of illustration, each of the passageways shown in the plane of the section.

Referring to Fig. 4, a fue] pump is showngenerally at 5 and consists of two housings 6 and 1 connected by a valve housing 8. Each ofthe housings v6 and I is divided into two compartments by diaphragms 9 and III, respectively. To the Vleft of the diaphragm 9 and to the right of the diaphragm I are fuel pumping chambers and I2, respectively. To the right ofv the diaphragm 9 and to the left of diaphragm 0 are actuating or vacuum chambers |3 and I4.

A fuel tank I is connected to pumping chamber II through pipe I6 and check valve |'I and to pumping chamber I2 through pipe I8 and check valve I9. A carburetor is connected to pumping chamber |I through pipe 2| and check valve 22 and to chamber I2 through pipe 23 and check valve 24. Stops 25 are provided in chambers and I2 to limit the outward moveme'nt of the diaphragms. Springs 26 and 2'I are provided in chambers I3 and I4, respectively, and these springs tend to urge the diaphragms 9 and lllvtoward .the stops 25.

The valve housing 8 vis provided with axialQ cylinder openings land 3|, .these cylinders being separated by a wall 32. vPortopenings 33a and 33h in cylinders 30 and 3|, respectively, open into a passageway 33 connected via passageway 34 to a sourceof vacuum. Port openings 35a and 35h in cylinders 30 and 3|, respectively, open into y a passageway 35 connected via passageway 36 to the' atmosphere. Fig. 4 shows that Vacuum port y 33h in cylinder 3| is located to the left of the a atmospheric port 35h in cylinder 3|, while vacuum port33a in cylinder 30 is also located to This non-symmetrical arrangement of ports is necessary `for proper operation.

Arport 3'I is formed in the wail of` cylinder 3|! and is connected by a passageway 38 to chamber I3. A similar Dort 39 is formed in the wall of the cylinder 3| and is connected to the chamber I4 by a passageway 4U. The axialwidth of

Y ports

31 and 39 is equal to the axial distance between the inner edge of vacuum port 33a and the outer edge of atmospheric port 35a, and also equal to the axial distance between the outer edge each provided with

annular grooves

43 and 44. A suitable groove is also provided in the piston for packing to provide for frictonal contact between piston and cylinder. Connected to each diaphragm 9 and I8 are

rods

45 and 46, respectively. Each of these rods is provided with spaced collars 41 and 48. The portion of the

rods

45 and 46 between the collars 41 and 48 is passed through an axial opening 49 in each of the pistons 38 and 3I, this opening being smaller than the collars 41 and 48. The inner ends of the pistons 38 and 3I are also provided with recesses in which the collars 41 may slide. It will be seen that the space between the collars 41 and 48 is greater than the length of the opening 49 so that there will be a-lost motion between movement of the rods and the pistons.

Referring now to the operation of the pump as shown in Fig. 4 the diaphragm I8 has just completed a discharge pumping stroke and is connected to the atmosphere through

passageways

36 and 35, port 35h, groove 44, port 39 and passageway 40. The diaphragm 9 has just completed an intake pumping stroke to the right and is now connected to the atmosphere through

passageways

36 and 35, port 35a, groove 43, port 31 and passageway 38. With the diaphragms in these positions, the fuel pumping chamber I2 has been ensmalled and the fuel pumping chamber I I has been enlarged and lled with fuel from the tank I5. diaphragm 9, will tend to ensmall the pumping chamber II, forcing the fuel through the check valve 22 and to the carburetor 28 through the pipe 2I During the rst stages of the movement of the diaphragm'S to the left, the piston 42 will remain in the position shown. VWhen the collar 41 on rod 45 contacts the shoulder at the end of the opening 49 of piston 42, the piston will start moving to the left with the diaphragm 9. When the piston 42 is moved to the left a predetermined amount, the groove 44 in the piston will rst be cut oil from port 35hl and atmospheric passageway 35 and then be connected to port 33h and to the passageway 33 in the valve housing, The passageway 33 is connected to subatmospheric pressure conduit 34 and 4consequently the actuating chamber I4 will be connected to sub-atmospheric pressure through passageway 34, passageway 33, port 33h, groove 44, port 39 and passageway 40. At this time lthe diaphragm I8 will start to move to the left in its intake stroke. Because of the lost motion between the collar 48 on rod 46 and the piston 4| there will be no movement of the piston 4I during the first stages of the movement of the diaphragm I8.

VAfter about half the stroke of the diaphragm is completed, the collar 48 will contact the piston 4I and move the same to the left thereby cutting off the chamber I3 from atmospheric port 35a and passageway 35, and as the piston 4I reaches the end of its leftward movement, the

chamber I3 will be connected to sub-atmospheric pressure through

passageways

34 and 33, vacuum port 33a, groove 43, port 31, and passageway 38. 'I'his will initiate the intake stroke of diaphragm 9. Chamber II will again be illled with fuel through pipe I6 and check valve I1 and the diaphragm I8 will then move to the right by the action of the spring 21 and will discharge fuel through the valve 24 to the carburetor. It will be seen that if the need for fuel to the carburetor is discontinued, the pump will cease its operation until demand is re-established, in which'c'ase, either

spring

26 or 21 may force its respective The spring 26, operating on thel diaphragm outward against the reduced fuel pressure in the discharge line feeding the carburetor. At this time the pump will again start to operate.

It is at the end of the discharge pumping stroke of diaphragm 9 that the actuating chamber I4 is connected to sub-atmospheric pressure and it is at the end of the intake stroke of diaphragm I8 that actuating chamber I3 is connected to sub-atmospheric pressure.l Similarly, at the end of the intake stroke of diaphragm 9, the chamber I4 is connected to atmospheric pressure and at the end of the discharge pumping stroke of diaphragm I8 the chamber I3 is connected to atmospheric pressure.

Referring now to the embodiment of the invention shown in Figs. 1, 2 and 3, reference characters from Fig. 4 have been applied torFigs. 1, 2 and 3 where they identify similar parts. The housing for the fuel pump in Figs. 1 and 2 is made up of a central housing 58 and two end housings 5I and 52 bolted appropriately to the center housing with diaphragms 9 and I8 interposed. Each of the housings 5I and 52 are provided with end chambers 53' and 54 respectively with suitable bail means 55 for holding the same in position. The end housing 5I is provided with an entrance port 56 leading to the housing 53. A filter screen 51 separates the end chamber 53 from entrance valves 58 and 59, and chamber 53 serves as sediment chamber. These valves are check valves of common construction. The valve 58 gives one way connection to chamber I2 and the valve 59 gives vone way connection to chamber II through passageway 68 in the housings 5I, 58 and 52. The chamber 54 which serves as an airdome to reduce pressure uctuations, is connected to the carburetor through a port 6I. A check valve 62 gives a one way connection from the chamber II to the chamber 54 and the check valve 63 gives a one way connection from chamber I2 to chamber 54 through a passageway 64 inhousings 52, 58 and 5I. The embodiment of the pump shown in Figs. 1 and 2 is mounted in operation so that the sediment chamber 53 is at the bottom and the airdome chamber 54 is at the top. Diaphragms 9 and I8 are clamped between reinforcing discs 65 and 66 which can serve also as stop members by contacting the housings at the ends of the stroke of y the diaphragm.

This sleeve 61 has twov cylinders 38a and :HaV

formed in each end and separated by the wall 32. These lcylinders which correspond to cylinders 38 and 3I of Fig. 4, are connected by the ports 33a and 33h and passageway 33 which is open to the suction or sub-atmospheric passage 34. Passageway 35 also connectsv the atmospheric ports 35a andy 35b in the cylinder walls and is open to the atmospheric passage 36.

Passageways

33 and 35, each in the form of an axial groove on the outside of the sleeve 61are diametrically positioned, as shown particularly in Figs. 2 and 3. In Fig. l the -

ports

31 and 39 and the

passageways

38 and 48, formed as axial grooves in sleeve 61, are shown diametrically positioned in the sleeve 61, the passageway 38 leading to chamber I3 and the passageway 48 leading to chamber I4. Within the cylinders of sleeve 61 are pistons 4Ia and 42a each provided with

grooves

43 and 44 respectively,

.as described in connection with Fig. 4. Rods 68 and 69 are attached to the diaphragms 9 and4 I8 respectively, which are clamped between the discs B and 66, and each rod is provided with a portion having a reduced diameter at its inner end to be received within an opening of the pistons #Ia and 42a. There is a lost motion connection between the pistons and rods as previously described. The operation of the embodiment of the invention shown in Figs. 1, 2 and 3 is identical with that described in Fig. 4 and will not be repeated in detail.

As shown in Figs. l and 2, the chambers I3 and I4 are connected to atmosphere and the diaphragm 9 is ready to start a discharge pumping 33h so that the source of sub-atmospheric pres-` sgre Will be connected to chamber I4 throughpasasgeway 40, port 39, groove 44, port 3317 and passageway 33. Similarly, when the diaphragm I0 has been moved to the right by differential pressures a predetermined distance, the piston 4Ia will then be shifted to the right to disconnect the chamber I3 from the atmospheric port and later be connected to the sub-atmospheric pressure through the passageway 38, port 31, groove 43, port 33a and pasasgeway 33. This will cause movement of the diaphragm 9 to the left and the chamber I4 will then be again connected to atmosphere as shown.

It is, of course, within the contemplation of the invention that a pressure above atmospheric be used in actuating chambers I3 and III. In such cases, a means equivalent to

springs

26 and 21 should be provided to urge the diaphragms in a direction opposite to that in which they are now urged by the springs.

What I claim is:

1. In a liquid fuel pump, opposed coaxial chambers, pumping elements in said chambers to divide each chamber into a fuel pumping chamber and-.an actuating chamber, means urging said pumping elements in a direction to ensmall said fuel pumping chambers, a central valve housing positioned between said pumping chambers, coaxial cylindrical recesses in said valve housing, valve members in said recesses, means connecting said valve members respectively to said pumping elements, an atmospheric passageway connecting said valve recesses, a sub-atmospheric passageway connecting said valve recesses, passageways connecting each of said actuating chambers with one of said valve recesses, said valve members being arranged to be shifted to connect respectively said atmospheric and subatmospheric passageways with said actuating chambers, the valve member connected to one pumping element being adapted to control the connection of pressure to the actuating chamber of the other pumping element.

2. In a liquid fuel pump, opposed coaxial chambers, pumping elements in said chambers to divide each chamber into a fuel pumping cham'- ber and an actuating chamber, means urging said pumping elements in a direction to ensmall said fuel pumping chambers, a central valve housing positioned between said pumping chambers, coaxial cylindrical recesses in said valve housing, valve members in said recesses, means forming a lost motion connection between said valve members respectively and said pumping elements, atmospheric passageway connecting said valve recesses, a sub-atmospheric passageway connecting said valve recesses, passageways connecting each of said actuating chambers with one of said valve recesses, said valve members being arranged to be shifted to connect respectively said atmospheric and sub-atmospheric passageways with' said actuating chambers, the valve member connected to one pumping element being adapted to control the connection of pressure to the actuating chamber of the other pumping element.

3. In a liquid fuel pump, a central housing having inlet and outlet openings for iiuid operation, a bore extending longitudinally of said housing, end pieces attached at each end of said housing forming operating chambers at each end of said housing, diaphragms in each of said chambers dividing the same into pumping chambers and actuating chambers, a wall centrally of said bore dividing the same into aligned valve chambers, valve members slidable in each of said valve chambers, means operably connecting each of said valve members with the diaphragm at its respective end of the housing, and passageways connecting`said valve chambers with said fluid inlet and outlet openings, the valve member connected to one diaphragm being adapted to control the connection of pressure to the other diaphragm and vice versa.

4. In a liquid fuel pump, a housing having two spaced, coaxial pumping chambers, inlet and'outlet openings for actuating fluid, and coaxial bores between said chambers, valves in said bores, diaphragms dividing said chambers into actuating and pumping sides, means connecting'each of said valves with a diaphragm whereby movement of a diaphragm actuates the valve connected therewith, and passageways formed in said housing between said openings and the actuating sides of said diaphragms whereby movement of one valve by one diaphragm controls the connection oftactuating uid to the other diaphragm and vice versa.

5. In a liquid fuel pump, a housing having two spaced, coaxial pumping chambers, inlet and outlet openings for actuating fluid, and bores arranged on an axis parallel with the axis of said spaced chambers, diaphragms dividing said chambers into actuating and pumping sides, means connecting each of said valves with a diaphragm whereby movement of a diaphragm actuates the valve connected therewith, and passageways formed in said housing between said openings and the actuating sides er said diaphragms whereby movement of one valve by one diaphragm controls the connection of actuating fluid to the other diaphragm anl'vice versa.

6. In a liquid fuel pump, a housing having two spaced coaxial pumping chambers, inlet and outlet openings for actuating fluid, and central bore connecting said chambers, diaphragms dividing said chambers into actuating and pumping sides, the actuating sides facing the central bore, a sleeve in said bore having surface openings there- 1n to connect the inlet and outlet openings of said housing with the actuating sides of said chambers, valves in each end of said sleeve, means connecting each of said valves with a diaphragm whereby movement of a diaphragm actuates the valve connected therewith, said` valves having surface openings arranged to cooperate with the openings of said sleeve whereby the movement of a valve connected to one diaphragm controls the connection of actuating uid to the other diaphragm and vice versa.

` CHRISTIAAN H. BOUVY.