US1640579A - Fuel-feed mechanism for oil engines - Google Patents

Description

ug 0 F. w. SEVERIN FUEL FEED MECHANISM FOR OIL ENGINES 3 sheets-sheet 1 1,640,519 AU8- 30 1927' F. w. SEVERIN FUEL FEED MECHANISM FOR OIL ENGINES Filed July 27. 1925v s sheets-sheet 2 1,640,579 All@ 30 1927' F. w. SEVERIN FUEL FEED MEcHANzsM Fon 01E ENGINES Filed July 27. 1925 :5 sheets-sheet 3 Patented Aug. 30, 1927.

UNITED STATES FRANK W. SEVERIN, OF CHICAGO, ILLINOIS.

FUEL-FEED MECHANISM FOR OIL ENGINES.

Application led July 27, 1925. Serial No. 46,379.

The invention relates to fuel feed mechalnism for oil engines.

One object of the invention is to provide imA roved fuel feed mechanism which is contro led by a governor which regulates the volume of fuel injected into the engine responsive to power requirements of the load, and in which the volume of the charges of the fuel is controlled by variation of the stroke of the fuel pump. Another object ofthe invention is to provide improved mechanism of this type in which the point of commencement of fuel injection is always the same under different speed and load coni5 ditions, the variation of the pump stroke resulting in varying the end of the injecv tion periods only.

A further object of the invention is to provide improved means for controlling the fuel pumps to selectively render any one or all of them inoperative or for manually operating the pumps when desired.

' Other; objects of the invention will appear from the detailed description. The invention consists in the several novel features hereinafter set forth and more particularly defined by` claims at' the conclusion hereof.

In the drawings: Fig. 1 is a section of mechanism embodying the invention. Fig. 2 is a 's'ection on line 2-2 of Fig. 1.. Fig. 3 is a section taken on line 3 3 of Fig. 1. Fig. 4 -is a horizontal section taken on line 4-4 of Fig. 1. Fig. 5 is a detail sectional view of one of the roller carrying slides and its guide. Fig. 6 is a section on an enlarged scale of one of the fuel pumps. Fig. 7 is av detail of the pump plunger. Fig. 8 is a detail of the adjustable collar on the pump plunger. Fi s. 9 and 10 are details of the pump operate valve in the pump barrel.

The invention. is exemplified in mechanism supported 1n a suitable frame or e bracket 10 which is usually mounted on the engine casing and carries a hollow shaft 11 which is eared to and driven by the crank shaft of the engine at a rotative speed suit'- able to the cycle of the engine. The mechanism shown is for a two-cylinder engine comprising a fuel pump and connections for each engine cylinder, although it is to be understood that the invention may be aplied to an engine having one or more cylinders, as well understood in the art.

longitudinal Each pump comprises a barrel or casing 12, which is provided with lugs 12a, which are bolted to the outer sides of the upright members l0a of the frame 10, and a piston 14, which is slidable in and fitted to a cylinder 13 in said casing. A spring 15 is applied t0 impart the retractile stroke to the pump piston, its outer end being interposed between the inner end of the casing and a collar 16 fixed to the piston. Collar 16 is adjustably connected to said piston, so that its outer end, which acts to feed the fuel oil to the injector, may be adjusted to vary the effective cycle of each pump stroke. For this purpose,vcollar 16 is connected by a screw-thread 16a to a screw-threaded stem 14 on the pump piston, and is split sothat it maybe firmly held in its assigned position by clamp-screws 16". A fuel chamber 21 is integrally formed with the pump casin to dispense with the icessity of provi ing communications between them. IA delivery pipe 22 is connected to deliver fuel from a suitable source'of supply into a duct 22", which delivers the fuel oil to the bottom of chamberl 21. A pet-cock 22b is connected to chamber 21, so that in initially'filling it, air can be discharged. from the chamber until it has been partially filled. A drain cock 22c is also connected to said chamber. vThe outer portion of the pump piston 14 is hollow, as at 14", and radial recesses 14 .are cut in the periphery of the pump piston to deliver fuel oil from the duct 22a into the hollow portion or outer end of the piston. The outer end of the piston is formed with a conical seat 14'l to engage the conical end of a valve 19, which.

is slidable in the outer end of pump cylinder'13. This valve is provided with a series 'of longitudinally extending peripheral slots 19a. which permit oil to flow from the pump cylinder into a chamber 18 adjacent the outer end of the cylinder and with an annular shoulder 19v adapted to engage a shoulder 12b formed in the casing 12, to limit the inward movement of valve 19 by a spring 20, which acts to hold the valve in its normal position yand permits it tok be shifted outwardly by and with the pump piston during t e injection cycle of the pumping stroke. The inner end of the spring is confined in a cylindrical chamber in the valve, and its outer end is held in a plug 18l which is screw-threaded to the casing 12 and closes the outer end of chamber 18. From chamber 18, the oil is forced through a duct 18b into a pipe 26, which is connected to deliver the oil in regulated quantities to the inspirator or injector for the engine cylinder. A check-valve 27 prevents backflow of the fuel.

In operation, the stroke of piston 14 is greater than that required for the maximum charges of fuel required by the engine, and each pumping stroke includes an idle cycle until the outer e'nd 14d of the piston seats against the valve 19, during which period oil will flow/from the opening 14b in the piston through cylinder 13 and slots 19a into the chamber 18, and a cycle during which the .piston is effective to pump oil while its seat 14-1 engages the inner end of valve .19 to cut off communication between the oil: 1n the piston and the chamber 18, and forces the valve outwardly to force a charge of oilv from the chamber 18 to the injector. By varying thestroke of the pump piston to increase or diminish the active cycle of its stroke, the volume of the charges may be regulated responsive to the power requirements of the load under control of the governor which correspondingly varies the stroke of the pump piston. This construction exemplifies one in which regulation of the volume of the chargesof fuel injected is regulated by the pump piston and dispenses with the necessity of a suction, by-pass or metering valve. The upper portion of chamber 21 forms an air cushion to destroy the inertia of the line of-oi-l between the supply tank and the oil in the piston and cylinder.

The mechanism for operating the pumps from shaft 11 comprises a cam 30 which is journalled on an eccentric 31 which is keyed tothe drive-shaft 11. This cam is adapted to operate the pumps in rotative succession,l

to vary the stroke of the pump pistons responsively to load variations by an automatic or centrifugal governor. Each pump piston is operated by cam 30 through a ro-ller 32 which bears against the periphery of said cam and is journalled on a pin 33. Said pin and roller are carried in a cylindrical member 34 which is slidably mounted in a depending lug 35 of an annular frame member 36, which is secured to the top of frame 10 by bolts 37. Each lug 35 is provided with inwardly extending arms 38 between which the inner end of member 34 is guided. A plate 39, secured to a flattened portion on the underside of member 34, engages the underside of arms 33 to secure the member and roller carried thereby againstrotation. An

abutment plate 40 held in the inner end of member 34 on shoulder 41 in said member is adapted to engage the inner end of the collar 16 to impart the pumping stroke to the pump piston. Spring v15, actlng against collar 16, retains the roller 32 in engagerollers 32 are in engagement with a portion 30a of the cam which is concentric with the veccentric 31, and as a result the active cycle of the pump piston always commences at the same point relatively to the crank shaft and piston movements of the engine, and'this, in practice, has been found to be an important feature, because it insures the timely delivery of the charges into the combustion chambers under varying speeds and loads. This result is attained, because rotative adjustment of the portion 30a of cam 30 by the governor does not vary the points at Which'the pump pistons engage thevalves 19 and commence the active pumping cycles. Normally, the cam portion 3()a 0f cam 30 is adapted to impart the'maximum'pumping stroke to the pistons, and as it is rotated by the governor, the points at which the pumping operation commences will remain the same, but the length of said strokes will be reduced to correspondingly reduce the active pumping cycles of the pistons and the extent to which the valves 19 are shifted, so that the charges of oil pumped to the injectors will be decreased responsively to the governor movement. Thisconstruction exemphfies one in which variable pumping strokes are imparted to the pump pistons to correspondingly vary the charges delivered to the injectors,without varying t-he.time of commencement of the delivery of the charges. It also exemplifies a construction in which the variations in the fuel charges delivered to the injector are effected by variation ofthe piston stroke and the valve operated by the piston,so that separate operating mechanism fora suction or control valve is dispensed with.

The governor mechanism for rotatably adjusting the cam 30 around eccentric 31 comprises a pair of weights-43, each pivoted by a pin 44 to an arm or extension 45 which is integral with the eccentric 31, so that the governor, arms will rotate with the shaft 11. Each Weight is provided With an' integral inwardly extending arm 46 provided with gear-teeth 47 which mesh with a gear 48 integrally formed on the lower end of cam 30. A spring 50 is applied to each' of the governor weights 43 to yieldingly resist their outward movement by centrifugal force and to retract them. Each spring is connected to an arm 51, which is pivoted by pin 52 to one of the eccentric arms 45. The tension of these springs is variable to adapt the governor for different running conditions,

and for this purpose each arm 51 is provided with an integral abutment lug 53 adapted to be engaged by a pin 54 which is radially slidable in the hub at the lower end of the lli) eccentric 31. These pins may be adjusted radially to rock arms 51 to vary the tension on springs lby a plunger 55, which is slidable in the hollow shaft -`11, and has a tapered lower end which, by vertical movement, is

vadapted to shift the pins 54. The upper holes in nut 57, so that by rotation of the cap, nut 57 may be turned to longitudinally adjust the plunger 55. A spring-pressed finger lever 62 is pivoted, at 63, to said cap and provided with a tooth 64 adapted to enter notches 65 in hub 58 to secure the nut in its adjusted position. Cap 60 is removably held on hub 58 by a screw 66 which extends intoan annular groove 67 in the upper portion of huh 58. An adjustable stop pin 68 is carried by one of the arms 45 on eccentric 31 to iix the normal position of said cam, and an adjustable stop-pin 69, carried by one of said arms 45, is adapted to engage the arm 46 of one of the governor arms to fix the maximum movement of cam 30hy the governor. v

In practice, it is sometimes desirable, for example in starting, to manually operate one or more of the pumps. It sometimes occurs that it is'desirable to render one ofthe pump pistons inoperative by the cam 30, for example, if one of the engine cylinders is not firing properly. 'For this purpose, mechanism is provided by which the pump pistons may be manually operated or `selectively rendered inoperative. This mechanism comprises an arm 70 for each pump' piston,

i which is pivoted at 71 to the underside of i operating the cam head 59 and is adapted to engage the head 33a of a roller pin 33 to force one of the pump pistons outwardly against the force of its retracting spring 15, so that itsoper-` ating roller 32 will be held free from enj gagement with 'the cam 30. Each arm 70 also carries an upwardly extending stud 72, which is adapted to be operated to shift the arm by a cam 73. This cam is disposed adjacent the underside lof head 59, and com-' prises an annular rib 74 having an eccentric Slot or cut-away portion l75 therein. Said cam is integral with the hub58, -Which extends through head 59, and a lever 76 for is iixed to said hub. A spring 77 is applied to each of the arms 70 to cause its stud 72 to be normally held against the inner periphery of rib74. Each of these springs has one of its'ends oo nnected to a stud 78 fixed tohead 59 and lts other end connected to an arm 79 integrally formed with arm 70, and these connections positions.

are arranged so that the spring will cross the dead-center and exert an inward pull on arms 7 0 when the studs 72 have' been shifted to engage the outer periphery of rib 74.

`Normally, the arms 70 and vcani 73 will be in the position shown by full lines in F ig..2, in

which the studs 72. will engage the inner periphery of rib 74 to hold the arms 70 in their inoperative position, so' that the heads 33a of the roller pins 33 will be free to permit the rollers and pump pistonsto be operated by thel cam v30. Whenit is desired to manually operate the pumps, as in starting the engine, the'operator will rotate the 'lever 76, so that, as the cam 73 is operated, springs 77, actingon arms 70, will `swing `them outwardly to cause studs 72 to enter the groove 75. After entering said groove, one side 7 5a thereof will act as a cam to force the studs 72 outwardly so that arms 470 will engage heads 33a and imparta ,pumping stroke to the pistons. The` operator may rotate the cam to operate one of the arms 70 or to operate them successively.- This ,manual pumping operation is effected by rotating the cam 73 infoneV direction. By reversing the rotation of said cam, the side 75b 0f groove 7 5-willengage the studs .72 andforce them inwardly to engage thev inner periphery of rib 74, which will force the arms 70 into the position shown by full lines in Fig. 2. By imparting selective strokes to the cam 73, either of the arms 70 may be operated to impart pumping strokesl to its pump piston or both of the arms may be operated in rotative succession. `The cam may also be manipulated to .selectively hold either or both of the arms 70 and the pump pistons controlled thereby in position to render the pistons inoperative by cam 30. `It will be understood that s rings 77 are applied to normally hold stu between the inner and outer peripheriesof rib 74, so that the studs will be ositively operated to swing the arms inward y or o utwardly according` to the direction in which the cam 73 is rotated. A` pin 80, carried by lever 7 6, is ada ted to enter sockets 81 in the upper face o head 59.` These are. located at points at which it may be desired to lock the cam 7 3, to hold said cam in such s 72 in a medial position yPin 80 is releasable by a ingere piece 82, which has a stem which is slidably y mounted in the handle 76-v of lever 76, and is suitably connected to release pin 8O against the force of a spring 83 which isv applied normally hold said pin in its operative position. l

This construction exempliiiescontrolling mechanism for fuel pumps, by which they may be singly, selectively or collectively rendered inoperative, l be singly or collectively operated to manuallyfo rate the fuel pumps. o 1 lMghanismY for controlling the starting and by which they may l of the engine by compressed air is mounted i may be modified Within the scope of the ap- I claim as new and .desire to pended claims, Without departing from the spirit and scope of the invention.

Having thus described the invention, what secure by Letters Patent, is:

l. In fuel feed mechanism for oil engines, the combination of a reciprocatory pump for feeding fuel oil tothe engine cylinder comprising a piston and a cylinder, a cam for operating the piston to pump the oil, a valve in the cylinder, for rendering the piston effective to deliveroil and operated by the piston, and means for adjusting the cam to vary the pumping stroke of the piston to vary the charges delivered to the engine.

2. In fuel feed mechanism for oil engines, the combination of a reciprocatory pump for feeding fuel oil to the engine cylinder comprising a piston and a cylinder, a rotatable cam for operating the piston to pump the oil, a valve in the cylinder, for renderingv the piston effective to deliver oil, andloperated by the piston, and mechanism Vfor adjusting the cam to vary the active cycle of the pumping stroke of the piston and to correspondingly vary the operation of the valve to vary the charges delivered to the engine.

3. In fuel feed mechanism for oil engines, the combination of a reciprocatory pump for feeding oil to the engine cylinder, comprising a piston having a duct extending to its inner end, and a cylinder in which the piston is slidable, means for delivering oil into the hollouT piston, a cam for operating the piston, a valve in the cylinder for closing the duct to ren-der the piston effective to deliver oil, operated by the inner end of the piston, and having a duct through which oil will flow, except when the valve is operated by the pist-on, and means for adjusting the cam to vary the pump strokes.

4. In fuel feed mechanism for o'il engines,

the combination of asupporting frame, an engine-driven shaft mounted in the frame, a reciprocatory pump for delivering charges of oil to the engine, comprising a piston and a cylinder supported by the frame and extending laterally from the shaft, a valve in the cylinder operated by the piston and for rendering the latter effective to deliver oil, a cam driven by the shaft for imparting pump strokes to the piston, and means for adjusting the cam to vary the pumping stroke of the piston so as to vary the charges deliveredto the engine.

5. In fuel feed mechanism for oil engines,

the combination of a supportingframe, a

vertically extending engine-driven, shaft With said eccentric, and a governor connected to rotate the cam on' the eccentric so as to vary the piston stroke.

6. In fuel feed mechanism for oil engines, the combination of a reciprocatory pump for delivering charges of oil to the engine, comprising a piston and a cylinder, an engine .driven shaft, an eccentric on and rotating With-said shaft, a cam for imparting pumping strokes to the piston mounted to rotate relativelyto and driven with said eccentric, and a governor connected-to rotate the cam on the eccentric to vary the piston stroke,

and a valve operated byand coacting With the piston to vary its eEective pumping cycle and the volume of the charges delivered responsively to variations in its stroke.

7. In fuel feed mechanism for oil engines, the combination of a reciprocatory pump for delivering charges of oil to the engine comprising a piston and a cylinder, -a n engine .driven shaft, mechanism for imparting variable strokes to the piston mounted to rotate relatively to and driven by said shaft,

a governor operatively connected to saidl mechanism, and means operated by and coact-ing with the piston to vary the effective cycle lof its stroke and the volume of the c arges delivered responsively to variations in its stroke, said means being formed so that the delivery of the oil by the pump will begin Withoutsubstantia'l variation in thetiming of the commencement of the oil delivery by the pump While said mechanism is in different positions. y

8. In fuel feed mechanism for oil engines, the combination of a reciprocatory pump for delivering charges of oil to the engine comprising al piston and a cylinder, an engine driven shaft, an eccentric on said shaft, av

cam for imparting pumping strokes to the piston mounted to rotate relatively to and `driven With said eccentric, a governor connected to rot-ate the cam relatively to the eccentric to vary the piston stroke, and

means coacting with the` piston to vary its effective-pumping cycle and the volume of the charges delivered responsively to variations in itsv stroke. said cam being rotatable to .vary the effective cycle of the pumping stroke Without substantial change in the timing ofthe commencement ofthe oil delivery by the pump.

9. In fuel feed mechanism for oil engines,

-1 rotatable by the governor without substantially varylng the'timing of the commencernent of the oil delivery by the pump while the cam is in its different positions.

10. In fuel feed mechanism for oil engines, the combination of a reciprocatory pump for delivering charges of oil to the engine. comprising a piston and a cylinder, an engine driven shaft, an eccentric on and rotating with said shaft. a cam for imparting pumping strokes to the piston mounted to rotate relatively to and driven with said :ccentric, a governor connected to rotate the :am relatively to the eccentric to vary the piston stroke, and aI valve operated by the piston coacting with it to vary its active cycle and the volume of the charges delivered from the cylinder .by the pump responsively to variations in its stroke, said cam being rotatable to its different sition without changing the timing of t e commencement of the delivery of oil by the piston.

11. In fuel feed mechanism for oil engines, the combination of a plurality of pumps for feeding oil to the engine, each comprising a piston and a cylinder enginedriven means for operating the plstons to pump fuel, a governor for adjusting the cam to vary the pumping strokesV of the piston, and a manually shiftable cam provided with means to selectively render any or all of the pistons inoperative.

12. In fuel feed mechanism for oil engines, the combination of a plurality of pumps for feeding oil to the lengine, each comprising 'a piston and a cylinder, an engine-driven cam for operating the pistons to pump fuel, a governor for adJusting the cam to vary the pumping vstrokes of the pistons, and a manually shiftable camprovlded with means to render any of the pistons moperative and for manually operating any or all the pistons to pump oil.

13. In fuel feed mechanism for oil engines, the combination of a drive-shaft, a plurality of pumps for feeding oil to the engine, each comprising a pistomand a cylinder, a cam on said shaft for operating the pistons to pump fuel, a governor for adj usting the camto vary they pumping strokes of the pistons, and a manually shiftable cam mounted to rotate around said shaft and provided with means to render any of the pistons inoperative and to manually operate them to pump fuel. l

14. In fuel feed mechanism for oil engines, the combination of a pump for feedformed in an integral portion of the casing below the piston and said connection and communicating with said delivery means forning an air cushion to destroy the inertia of the line of oil, and a cock on said receptacle for exhausting the air therefrom.

l5. In fuel feed mechanism for oil engines, the combination of a plurality of pumps for feeding oil to the engine, each comprising a piston and a cylinder, enginedriven means for operating the pistons to pump fuel comprising a cam, a governor for adjusting the cam to vary the pumping strokes of the, piston,A and means whereby any of the pump pistons may be selectively rendered inoperative by the cam and whereby the pistons may be manually operated.

16. In fuel feed mechanism for oil engines, the combination of a plurality of pumps for feeding oil to the engine. each comprising a piston and a cylinder, engine- -driven means for operating the pistons to pump fuel comprising a cam, a governor for adjusting the cam to vary the pumping strokes of the piston, and a rotatable member whereby any of the pump pistons may be selectively rendered inoperative by the cam and whereby the pistons may be manually operated.

Signed at Chicago, Illinois, this 9th day of July, 1925.

FRANK W. SEVERIN.

Images