US2348538A - Fuel pump - Google Patents

Description

May 9, 1944.

K. R. HAGEN 2,348,538

FUEL PUMP Filed July l. 1942 2 Sheets-Sheet 1 May 9, 1944. K. R. HAGEN 4 2,348,538

` FUEL PUMP V Filed July l. 1942 2 Sheets-Sheet 2 /m/E/v Tae Patented May 9, 1944 Y UNITED STATES- :IPATENT OFFICE,

Karl R. Hagen, Canton, 01110,. assignor to The Timken Roller BearingCompany, Canton, Ohio, a corporation of Ohio `Application July 1, 1942, Serial No. 449,224 iociaims. (ci. ros-20"!) This ,invention relates to pumps. particularly diaphragm pumps for supplying fuel to the charge forming device of an internal combustion engine. The invention has for-its. principal ob- II extends from end to end of said housing along a diameter of said chamber with its end portions presstted in axially alined cylindrical openings provided therefor in opposite ends of said hous-v between the pivots 23 therefor andthe pects to provide a strong, compact and durable 5 ing. The sleeveII has a closed end I2 disposed diaphragm pump of simple and economical conflush with the corresponding end of the housing struction, to facilitate assembly and disassembly I;,and the opposite end of said sleeve is left open of the parts, to increase the discharge capacity and has an exterior collar or shoulder` I3 disposed ofthe pump, to provide a continuous discharge in endwise abutting relation to the corresponding of fuel, and to provide readily accessible manually l end of said housing.

operable means for priming and ilushing the Reciprocable in the open end of the sleeve II pump. The invention consists inthe pump and in is an inwardly opening tappet cup I4 whoseclosed the construction, combinations and arrangements outer end is engaged by a power operatedl'otary hereinafter described and claimed. edge cam or tappet l5, which preferably forms In the accompanying drawings, which form l part ofthe fuel injection pump (not shown) that part of this specification and wherein like symiS t0 be Supplied with fuel by the fuel Supply bols refer to like parts wherever they occur, purhp-V Reoiprooable in the Sleeve l l between the Fig. 1 is a side elevational view of a pump emclosed end I2 thereof and the tappet Cup ll in bodying my invention, l i the open end thereof, is a cylindrical crosshead Fig. 2 is an end elevational view of said pump, 20 I6; and located in said sleeve, one on each side Fig. 3 is a central vertical longitudinal section of Said CroSShead, are tWo Coil Compression Springs through said pump on the line `3 3 in Fig. 1, I1 and I8 of substantially the same size, rate, and Fig. 4 is a central vertical transverse section capacity. The spring Il bearS at one end against through said pump'on the line l-lin Fig. 2l, the 'crosshead I6 and -has its other end seated Fig. 5 is a vertical section on the line 5-5 ine on a button I9 that is located in the tappet cup Fig. (i, r d I4 and has a convex spherical head that seats Fig. 6 is a` horizontal section on .the lineE-Ii` against the closed cam engaging end of Said oup- Ain Fig, 4; and a The other spring I8 seats-at one end against the Fig. 7 isa vertical section on the line 1`1 in other end of the orosshead I6 and at its other Fig. 4. l 3o end against the closed end I2 of thespring and My fuel pump comprises a casing including a. crosshe'ad supporting sleeve II. main housing or body member' I and horizontal A horizontal pin 20 ts in a diametrical bore intermediate and bottom plates 21and 3, respecprovided therefore in the crosshead I6 and extively, that are clampedV flatwise .'together and tends onopposite sides of said crosshead through to the underside of said housing by screws 4. "I'he 35 diemetrioelly opposed longitudinal guide Slots 2l intermediate plate 2 has a cent1-a1 circular recess provided 'therefore in the sleeve II. Duplicate 5 in the top thereof that'is covered by a horizonrook 'levers 22, preferably of laminated constructal diaphragm 6, which is clamped between said tion, are located in the chamber `II) of the housplate and the underside of the housing l and ing l, one on each Side of the orosshead Supportconstitutes the movable Wall of an expansible up- 40 ing Sleeve H and are Pivotauy Supported at One per or main pump chamber A formed by Said daend for vertical swingingv movement in said champhragm and recess. An accumulator or cushionber on axially alined vpivots 23 that project into ing chamber B is vformed below the pump cham.. said chamber from opposite sides4 thereof. 'Ihe ber A by a central circular reces's 'I in the bottom hqlizontal COSS Pin 2 Carried by the CIOSShead. of the intermediate plate 2 and a diaphmgm s 45 I6 extends on opposite sides of the sleeve II into `that covers'said recess and4 is clamped between. arcuate Slots 2,4 provided therefor in the free said intermediate plate and the bottom p1ate'3. ends of the rook levers 22 The diaphrasmor As shown in the drawings, the diaphragm or-demovable wall 6 of the upper pump chamber A formable wall 8 of the lower pulsation chamber hals an upright Stem 25vXed thereto Which eX- Bis pressed upwardy byacoil compression spring tends upWardy into the chamber III centrally '9 so as to reduce the capacity or volumetric conthereof endhaS oppostely extending arms 26 at tent of said chamber and deliver fuel therefrom. itsnpper end that terminate atA their outer ends 'Il'he housing or casingl has a central circular in trunnions' 21 that are pivotally Supported in cylindrical downwardly opening chamber I0 openings provided therefor inthe respective rock therein; and a hollow cylindrical horizontal sleeve levers 22 I0. The inlet end of the intake or inlet passage- Way or conduit 28 has a suitable inlet fitting 30 therein; and an outlet fitting 3I, similar to the inlet tting 30, is threaded into the outlet end of the outlet or discharge passageway 29. The inlet passageway 28 leads downwardly from the inlet tting 30v through the housing I into the intermediate plate 2, where it openslaterally A into the main or upper pump chamber A. The outlet passageway 29 leads from-the opposite side of the main pumping chamber A upwardly through the intermediate plate 2 and housing I to the outlet iltting 3l.

Mounted respectively in the inlet and outlet` passageways forming bores of the housing I are the inlet and outlet valve assemblies of identical construction, each valve assembly comprising a cage 32 and a valve seat member V33 fitting in said bore, and a disk valve 34 mounted in -said casing and yieldably held against said seat by'la coil compressionV spring 35. As shown in the'I drawings, the two valve assemblies are mounted in reverse positions in their respective passageways, so that the valve in the inlet passageway functions as an inwardly opening check valve and the valve in the outlet .passageway functions as an outwardly opening check valve. The outlet passageway 29 communicates at its lower or inner end through branch passageways 29a. with the -lower or accumulator or cushioning chamber B;

and said lower chamber is in continuous communication with said outlet passageway, outwardly 'of the outlet valve therein, throughan auxiliary outlet or discharge passageway 36 that leads horizontally from said chamber and thence upwardly at an oblique angle to the main outlet passageway.

The operation of they hereinbefore described fuel supply pump is as follows: When the drop or base circle of the cam or i; pet I5 moves into position opposite the closed o r end of the tappet cup I4, saidtappet cup is pressed against said cam by thespring I1, andthe crosshead I6 is slid outwardly in the same direction in the sleeve II by the expansive action of the pumping spring I8, whereby the slot-and- pin connections 20, 24 between said crosshead and the rock levers 22 cause the latter to swing upwardly on their supporting pivots 23 and raise the diaphragm or movable wall 6` of the main pump chamber A arid thus dr'aw fuel into said chamber through the valve inlet passageway 28. When the nose or rise of the edge cam I5 engages the tappetcup. I4, the

crosshead I6 is slid inwardl in th l y e s eeve H admits of considerable modiiication without deagainst the pressure 'of the springs I1 and I8 and the slot-and-. pin connections 20, 24 between said crosshead and the rock levers 22 cause the latter to swing downwardly on their supporting pivots 23 and depress the diaphragm 6 of the main pumping chamber A, thereby forcing the fuel from said chamber 'through the valved outlet passageway 29.

As the rates of the springs I1 and I8 are the'A same, the maximum stroke of the crosshead I6 is equal toone-half the stroke of the camor tappet I5, and the position of said crosshead in its'supporting sleeve II depends on the'balance of the forces-of the twosprings in the dierent positions of the tappet cup I4. Thus, the length of stroke of the crosshead I6 andthe quantity of yfuel drawn into and discharged from the main pumping chamber A vary according to the back press ure of the fuel in the fuel discharge line, the

quantity of fuel discharged depending on the fuel consumption of the engine regardless of the length of stroke of the cam I5.

- As each stroke of the diaphragm 6 of the main pump chamber A produces a pressure pulsam tion, there is an intermittent delivery of fuel from said chamber. With a minimum pressure, the

springs I1 and I8 will impart a full stroke to the crosshead I6; and, as the pressure builds up, the

stroke of the crosshead will be diminished until a maximum pressure is reached at which the crosshead remains stationary and .1o movement is imparted 'thereby to the diaphragm 6. When the fuel injection pump is not able to use the full discharge of the supply pump, the surplus fuel is forced into the auxiliary or accumulator chamber B,thus forcing the diaphragm or movable wall il4 thereof downwardly against the resistance of the loading spring 9 and increasing the capacity or volumetric content of said chamber; and, as

25 this auxiliarychamber is always in communication with the outlet passageway 29 outwardly of the outwardly opening check valve therein, the spring 9 will operate to force the fuel from the auxiliary chamber into the discharge line when 30 the pressure decreases between discharge strokes of the main pumping diaphragm 6 and thus maintain a constant discharge of fuel from the supply pump. This lower or auxiliary chamber B also increases the discharge capacity of the pump due to the fuel stored in said chamber during the intermittent peak pressures produced by the diaphragm 6 of 'the main pump chamber The above fuel supply pump is also provided with a vseparate or'auxiliary manually operable priming or ushing means. Said means preferably comprises a hand lever 31 i'lxed to the exposed outer end of a .horizontal rock shaft 39 that is journaled in the. housing I and extends into the chamber I0 therein, where it is provided with a. cam 39 adapted to swing downwardly into engagement with the inclined upper ledge of one -of the rock levers 22, to thereby force said lever and the diaphragm 6 connected therewith downwardly. The hand `lever 31 is normally held in inoperative position with-the cam 29 clear of the rock lever 22 by means vof a cill`t'orsion spring 49 having one end anchored to the housing and the other end hooked around 55 said lever. This hand lever may be operated to impart a' pumping stroke to the diaphragm 6 regardless of'the position of 4the pump actuating cam I5. n

Obviously, the hereinbefore described pump ber, and means for reciprocating said diaphragm' to successively increase and decrease the volumetric content of said chamber, said means including a member operatively connected to said diaphragm and reciprocable insaid casing in a i 76 direction transverse to thedirection of reciprocation of said diaphragm, a springifor moving said member in one direction, and a rotary cam for moving said member in the other direction against the pressure of said spring, and manually operable means for moving said member'in said' other direction against the pressure of said spring in all positions of said rotary cam.

2. A pump comprising a casing having an ex pansible chamber and inlet and outlet passageways communicating with said chamber, a diaphragm forming a movable wall for said chamber, and means for reciprocating said diaphragm to successively increase and decrease the volumetric content of saidchamber, said means including a member operatively connected to said 41li diaphragm and reciprocable in said casing in a direction transverse to the direction of reciprocation of said diaphragm, a spring for moving said member in one direction, and mechanically operable means for moving said member in the 2o other direction against the -pressure of said spring, said mechanically operable means coinprising a tappet cup reciprocable in said casing in the direction of reciprocation of said member,

parted to said tappet cup by said cam.

3. A pump comprising a casing having an expansible chamber and inlet and outlet passageways communicating with said chamber, a dia:

, phragm forming a movable wall for said chamber, and means for reciprocating said diaphragm Vto successively increaseand decrease the volumetric content of said chamber, said means including a member reciprocable in said casing and operatively connected to said diaphragm, a spring for displacing said member in onedirection, and

means for displacing said member in the other 10 direction including a power operated member and a spring between said member and lsaid power operated member, the two springs being of substantially equal strength, whereby the position oi' diaphragm and reciprocable in said casing trans versely o'f the direction of reciprocation of said diaphragm, .a spring interposed between said oasing and one end of said crosshead for displacing the latter in one direction, and means for displacing said crosshead in the other direction including a power-operated member and a spring between said member and th other end of said crosshead, and means for manually operating said diaphragm against the pressure of said rst mentioned spring.

6. A pump comprising a casing having an Aexpansible chamber and inlet and outlet passageways communicating with said chamber, a diaphragm forming a movable wall of said chamber, and means for reciprocating said diaphragm to successively increase and decrease the volumetric content oi said-chamber, said means including a crosshead operatively connected to said diaphragm and reciprocable in said casing trans. -versely of the direction of reciprocation o! said diaphragm, a spring interposed between said casing and one end of `said crosshead for displacing the latter in one direction, and means for dlsplacing said crosshead in the other direction including a power operated member and a spring between said member and the other. end of said crosshead, the connection between said crosshead and diaphragm including a rock lever pivotally supported in said casing i'or swinging movement alongside of said crosshead in the direction of reciprocation of said diaphragm, a slot in said lever, across-pin xed to said crosshead and extending into said slot, and a spindle connected to said diaphragm and pivotally connected to said lever between the pivot therefor and the slot therein.

7. A pump comprising a casing having an expansible chamber and inlet and outlet passa'geways communicating with said chamber, a diaphragm forming a movable wall of said chamber, and means for reciprocating said. diaphragm to successively increase anddecrease the volumetric4 content oi' said chamber, said means comprising seid member, is determined by the balance of a crosshead operatively connected to said diaforces of the two springs in the different positions of the power operated member andthe length of stroke of said member and the diaphragm actuated thereby vaies according to the back pressure in said outlet passagewa 4. A pump comprising a casing having an expansible chamber and inlet and outlet passageways communicating with said chamber, a diaphragm forming a movable -wall of said chamber, and means for reciprocating said diaphragm 65 to successively increase and decrease the volumetric content of said chamber, said means including a crosshead operatively connected to said diaphragml and reciprocable in said casing trans Vversely of the direction of reciprocation of said diaphragm, a spring interposed between said ca sing and one end of said crosshead for displacing the latter in one direction, and means for dis' placing said crosshead in the other direction including a power-operated member and a spring between said member and the' other end of said g crosshead.

5. A pump comprising a casinghaving an expansible chamber and inlet'and outlet passageways communicating with said chamber, a diaphragm forming a movable wall of said chamber, and means for reciprocating said diaphragm to successively increase and decrease the volumetric content of said chamber, said means including a crosshead operatively connected to said 50 for displacing the latter phragm and reciprocable in said casing transi ment of said diaphragm, a spring interposed between said casing and one end oi' said crosshead in one direction, and means for displacing said crosshead in the other direction including a power operated member and a spring between said member and the other end of said crosshead,sald connection between said crosshead and diaphragm including a rock lever pivotally supported in said casing for swing` ing movement alongside oi.' said crosshead in the direction of reciprocation of said diaphragm, a slot in said lever and disposed at an oblique angle to the direction of reciprocationof said crosshead, a cross-pin xed to said crosshead and extending into said slot, and a spindle connected to phragm forming a movable wall oi' said chamber,

and means for reciprocating said diaphragm to successively increase and decrease the volumetric content of said chamber, said means comprising a crosshead operatively `connected to Said diaphragm and reciprocable in said casingtransvers'ely of the direction of reciprocation of said diaphragm, a spring interposed between said casing and one end of said crosshead for displacing the-latter in one direction, and means for displacing said crosshead in the other direction including a power operated edge cam, a tappet cup and a spring between said tappet cup and the other end of said crosshead, said connection between said crosshead and diaphragm including a pair of rock levers pivotally supported in said casing for swinging movement on opposite sides of said crosshead in the direction of reciprocation of said diaphragm, slots in said levers, a crosspin fixed to said crosshead and extending on opposite sides thereof into said slots, anda spindle fixed to said diaphragm and pivotally connected to said levers between the pivots therefor and the slots therein.

9. A pump comprising a casing having an expansible chamber and inlet and outlet passageways communicating with said chamber, a diaphragm forming a movable wall of said chamber, and means for reciprocating'said diaphragm to successively increase and decrease the volumetric content of said chamber, said means comprising a sleeve mounted in said casing. transversely of the direction of reciprocation of said diaphragm,

' a crosshead reciprocable in said sleeve, a spring mounted in said sleeve between one end thereof and the corresponding end ofsaid crosshead for displacing the latter in one direction, and means for displacing said crosshead in the other direction including a power operated edge cam, a tappet cup reciprocable in said sleeve and a spring mounted in said sleeve between said tappet cup and the other end of said crosshead, said connection of said diaphragm, slots in said levers, a

cross-'pin iixed to said crosshead and extending .on opposite sides thereof through longitudinal slots in said sleeve into said slots in said levers and a spindle xed to said diaphragm and pivotally connected to said levers between the pivots therefor and the slots therein and a manually operable cam mounted in said casing and movable into engagement with one of said levers for operating the same in one direction of its swinging movement.

10. A- pump comprising a casing having an expansible chamber and inlet and outlet passageways communicating with said chamber, a diaphragm forminga movable wall for'said chamber, and means for reciprocating said diaphragm to successively increase and decrease the volumetric content of said chamber, said means comprising a member operatively connected to said diaphragm and reciprocable in said casing in a direction transverse to the direction of reciprocation of said diaphragm, a spring in engagement with one end of said member for moving the same v in one direction, and means for moving said member in the other direction against the pressure of4 said spring, .said means comprising a second spring having one end in engagement with the other end of said member, a tappet cup engaging the other end of said second spring, and a rotary edge cam engaging said tappet cup for moving the same against the pressure of said second spring. g K

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