US2196969A - Engine starter - Google Patents

Description

April 16, 1940.

ENGINE STARTER Filed Jan. 11, 1937 3 Sheets-Sheet 1 64 N V EN TOR. 23 AERGER I v 9 \/8 2o I ATTORNEYS. 35 Comma-$55010?- K. BERGER 2,196,969

April 16, 1940. K. BERGER ENGINE STARTER Filed Jan. 11, 1937 3 Sheets-Sheet 2 IN V EN TOR. E2652.

@iiffw A TTORNEYS,

April 16, 1940. K BERGER ENGINE STARTER FileclJan; 11, 1957 3 Shets-Sheet 3 INVENTOR. fiur: BEEGEQ A TTORNEYS.

25 cylinder in such manner that an easy engagement of the clutch heads is insured and all detrie mental or undesirable impact and strain on the Patented Apr. 16,1940

UNITED STATES e ENT OFFlCE 2,1,s6,9s9 it ENGINE STA TER Knute Berger, Seattle, Wash. Application January 11,1937, Serial No.1119,938

5 Claims. (01. 121 -37) This invention relates to engine starting means,

and has for its principal object to provide relatively inexpensive, eifective' and substantial means for'cranking, or startingheavy engines of the Diesel, or other internal combustion types.

More specifically stated, it is the object'of the present invention to provide an engine cranking mechanism wherein a rotatably mounted and longitudinally shiftable cranking shaft is axially alined with the engine shaft and is equipped for a one-Way drive clutch connection therewith for the starting operation, and wherein the cranking shaft is operatively connected with the piston of an air cylinder for rotation thereby upon admittance of air under pressure into the air cylinder;

the admittance of air to the cylinder being under control of a novel valve mechanism whereby, coincident with the adniittance of air pressure and rotation of the cranking shaft,'an application of air into another cylinderis effected whereby to I move the cranking shaft longitudinally and into a cranking connection with the engine shaft.

It is also an object of this invention to provide,

through the above-mentioned valve mechanism, for the application of air pressure into the said mechanism affected is avoided. I I

Another object of the invention is to provide means for effecting an automatic return of the I parts of the starting. device to normal position upon the starting of the engine I Still another object is to provide means for,

cushioning the drive of the starting piston at the end of its power stroke.

I Other objects of the invention reside in the details of constructionand in the combination of parts and in theirfmode of operation, as will hereinafter be described.

In accomplishing these'andother objects of the invention, I havepro vided'the improved de-' tails of construction, the preferred forms of which are illustrated in the, accompanying drawings, wherein- -Fig 1 is a view diagrammatically illustrating an engine and a starting or cranking equipment applied thereto in accordance with the present invention. i

Fig; 2 is an enlarged detaiL'partIy in section and partly in elevation,- of the present engine starting mechanism. I,

Fig. 20. is an enlarged detail of the double acting valve. 3

Fig. ,3 is anendelevation' of the starter mechanism; the control valve being omitted for better illustration. i

Fig. 4 is an enlarged, sectional detail on the axial line of the valve mechanism for controlling the application of air pressure for. moving the cranking shaft.

Fig. 5 is a cross'section on line5-5 in Fig. 4,

showing the valve disk in normal position.

Fig, 6 is a similar view at' a reduced scale showing the valve disk in exhaust position; Fig. 7 is an'axial section of the air cylinder;

Figs. 8 and 9 are sectional details respectively showing the air relief valve in the cylinder. Fig. 10 is a detail illustrating an alternative means for returning the parts of thestarter to the present invention, and this'shaft' is revolubly mounted by, and is slidable longitudinally within engine and starting equipment are supported. I At their adjacent ends, the engineshaft 2 and the cranking shaft 4, as shownin Fig. 2, are

equipped, respectively, with clutch heads I and 8 and these have annular flanges l and'B' equipped with ratchet teeth9 and Ill a'dapted',by' shifting shaft 4 endwise, to be brought into interconnecting contact whereby to provide a one way driving connection between shafts 4 and 2 for startina the engine.

Fixed on the shaft 4, at the'outer end of bearing 5, is an acceleratin g sheave wheel 12 through which the shaft may be rotated, "as will presently be described, and this wheel is provided in its hub portion l2 with a plurality of inwardly I opening sockets l3 in which vcoiled springs M are seated and retained under compression and which springs bear against a disk, or plate 15 disposed shaft 4 of the startingmechanisrn' embodied by a bearing 5 which is fixed-to,-.or is formed as a I part of a rigid frame structure 6 by which the against the outer end'of bearing 5, thus normally to retain the shaft l yieldingly at its outer limit of longitudinal travel at which position the clutch teeth of the parts 1 and 8 are disengaged. In order to start the engine through the me'diacy of shaft 4, it is necessary to bring the clutch heads intointerlocked relation and to r"o-- tate the shaft. After each cranking operation, it

by frame 6 and has its end portion wound upon As will be noted by reference to Fig. 3, the cable 23 1 the sheave wheel l2, and fastened thereto.

leads into the peripheral channel of the sheave l2 at its point of greatest diameter and is fixed to the wheel at the point of shortest diameter;

This disposition of the cable provides that, with-- the piston 59 located at the outer end of its cylinder !8, that being the right-hand end .as viewed in Fig. 1 and Fig. '7, should air pressure be applied to the cylinder to drive the piston toward the opposite end thereof, the longer cranking leverage provided through the sheave 12 at the start of the cranking operation will aid greatly in overcoming the inertia in the engine parts. Then, as the wheel I2 is rotated, the gradually decreased effective diameter of the wheel will effect the speeding up of the rotation of the cranking shaft as this inertia is overcome and the rate of travel of piston 19 increases. .The arrangement provides also for a relatively slow starting and then a quick acceleration of the cranking shaft that avoids undesirable strains and stresses.

The application of compressed air to the cy1- inder It! for starting the engine is under automatic control of a valve mechanism designated in its entirety in Fig. 2 by reference character 25. This mechanism, as seen in detail in Figs.

4 and 5, comprises a valve housing 26 that is fixed solidly in the frame structure 6 in alinement with shaft 4. At its inner end, this valve housing is formed with a cylindrical chamber 2! that is axially alined with shaft 4 and within which cylinder is slidably fitted an enlarged, piston forming portion 28 at the outer end of the shaft 4.

ing shifting of shaft i, and it is this shifting of shaft 4 in opposite directions that eiTects the engagement and disengagement of the teeth of clutch heads 1 and 8.

Formed in-the outer end of the valve housing 25 is a pocket 30 that is closed by a cover plate 3! bolted to the housing. A source of compressed air is designated, in Fig; 1, at 35, and this source is connected by a pipe 36,; through a valve device 3'! and pipe 38, with the closed pocket 3! the pipe 38 communicating. with through the cover plate 3!.

The construction of valve 3'! is such and it is so connected with the source of air pressure and the cylinder l8, that when in position, it closes the outlet of air from the supply and opens the pipe 38 to atmosphere to exhaust air' from the cylinder H? for return of piston I9 to normal position. 'When' valve 3? is opened, it effects a connection between pipes 36 and 36 for the admittance of air into clinder [8 to actuate the" piston is on its power stroke. As will be notedbestby reference to Fig. 4, the pocket 36 had a flat base surface, upon which a flat valve disk ll) is fitted in an air tight con- Movement of this piston 28 longitu-' dinally in the cylinder 2! effects a correspondthe pocket nection. The disk has an axial stem, or shaft 4! extended therefrom and revolub-ly contained. in an opening 52 leading into the cylinder 2?. This stem extends slidably into an axial. bore 43 in the outer end of. piston 28. A transverse key M fixed in the stem 4i and movable in a longitudinal slot 15 in the piston provides a positive connection between the shaft 5 and valve disk 40 whereby the disk is rotated in accordance With rotation of the shaft '2, but relative longitudinal movement of shaft l is permitted .on stem My The valve disk 40 is held tightly seated by I means of a coiled spring 58 that is confined under compression in an axial socket 5i in the outer face of the disk and bears, at its outer end,

against a ball 52which,=in turn seats against the cover plate 3!.

Formed through the valve disk, and extending through an angle of approximately about the disk center is anarcuateslot 553. 'When the disk is in its normal position, as just priorto an application of starting air, one end of this slot fill just slightly overlaps-a port or channel 62 which is formed in the valve housing and which provides a connection with a pipe 54 leading to the outer end of the air cylinder 28. Thus when air pressure is applied to the pocket 30,;it is communicated through the arcuate'slot 66, portor channel 62 and pipe 64 into one end of the cylinder l3 and actuates the piston toward the opposite end. The arcuate slot. 69 is of'such extent that it will maintain communication between the source of air pressure and cylinder it throughout the travel of the piston and the resu1tant;rotative.movement'of the shaft-t and valve disk. By reasonof the opening that is pro vided by the slot iifhjust slightly overlapping the port 62, flow of air under pressure to the cylinder l8 will be initially restricted to such extent that the piston 28 will be-actuate'd to engage'thef clutch heads 7 and 8 prior to the, application or air pressure to the cylinder I8 for effecting the rotary action of the shaft 4. i

It will be observed also that thereisa port 10 formed directly through the upper part of the disk, as shown in Fig. 5, andthatthis, when the'parts are in normal position and at the start of an operation, has direct registration with a port H in housing 26 leading into the inner end of cylinder 21. Thus, coincident with the application of air to the cylinder !3 there will bean application of air under pressure into .cylinder 21, thereby to overcome the pressureof springs l3 and to movethe piston 28and shaft -i-longitudinally, thus tocause the teeth of clutch heads I and 6 to be operatively engaged.

It, will now be understood thatfresultantto the application of air intopocket 30 by opening valve 31, there will be effected a movement'of piston "3 whereby, through the mediacy of cable 23 and sheave J2, the shaft 4 willbe' rotated, and also, by reason of longitudinal shiftingkof shaft 4, that the clutch heads will be. engaged so that the rotation of shaft 4 willeffectthe driving of the engine shaft 2 for the startingor cranking operation. v

By reasonof the factthat the registering openings 10 and H will provide a direct passage for compressed air admitted to the pocket'iiii into the cylinder2'l, and because the springs M- afford less resistance to shifting of the shaft 4 than'is afforded to the actuation of the cranking mechanism by spring I35, the piston 28 will be actuated inwardly to engage the clutch head "8 with athe clutch-ahead I :loefore there .is any ,.-ro,tation;:of' the crank shaft effected *by the rac- =tion of :the compressed air admitted to cylinder Referring again to Figs. 4 .and '5, ;it .zWill benoted that there is .a relativelyshort arcuate groove For channel .15 formed .in the under surface of the .valveidisk about the disk axis which,

' shortly after the valve disk starts to rotate by reason of application of air pressure into cylinder [8, will move into :a' position at which it serves as a communicating passage between the port 5!! and an .air exhaust port l'll opening upwardlyto atmosphere through the valve housing 7 wall. This prov-ides that, afterithe clutch heads haverbeen engaged for starting the engine, and after power has been. applied for rotating the shaft 4, air iwillibe exhausted from cylinder )2! and thus ,just as soon as driving contact between the teeth of the two clutch'heads is relieved, the

shaft 1! will be shifted outwardly by the action-of the springs l3,and the clutches thus disengaged.

This driving contact which. holds the ratchetteeth of the clutchesengaged will be relieved either by reason of the starting o'fthe engine-under its own power and turning at aiaster rate than the cranking shaft, -or by, reason of the piston i9 7 reaching itslimit of travel.

As soon asthe piston I Breaches it limit of travel in cylinder IS, the operator closes valve 31, and thus, as was previously explained; air is exhausted from the powerend of cylinder l8, and the piston is returned to normal position and ready for another starting operation by means of a coiledspring fi5 which is fixed atone end to frame 5 and is attached,"undertension, at its other end to-a cable 86, which leads over a sheave 81 onto the sheave l2 and is wound thereon in. a direction opposite to cable 23 and is attached-thereto.

In Figs. 10 and Ill-an alternative means for'returning the shaft 4 to normal position is shown.

In this, a helical spring 89" i's applied to the sheave and has oppositeends connected, respectively to the sheave as at 9! in Fig. 10, and to a I pin 90 fixed in frame 6.

' In order that the drive of piston l 9 in cylinder l8 may be cushioned on reaching the outer limit of its travel, an air cushion-valve mechanism is provided in the cylinder, as will best be understood by reference to Figs. '7, 8 and 9. This valve mechanism comprises a tubular valve stem 92 that is slidably-fitted in an axial'bore 93 in the cylinder end head 181). This stem has a valve head 94 at its inner end adapted to close over a pocket 95 formed'in the inner face of the head 18a about the stem 92, and from which pocket portsflfi open to atmosphere. A coiled spring 91,

seated in the pocket and bearing against the valve head, holds the valve yieldingly inopen position. The inward opening travel of the valve 52 between the inner end of the stem lll5'and a plug 508 that closes the outer end of the tubular stem 92. For reasons presently apparent, the

' spring I01 is stronger than spring 91.

When the. piston l9 moves on the power stroke under influence of compressed air admitted :th-rough pipe "64, it causes .a ready exhaustion of .air from the cylinder end through the pocket 95 and ports 96. However, as the piston nears its limitof travel, itengages the inner end of stem H15, and pushes it, together with stem 92 outward- .seat, andltherebycuts offlescape of air to atmos- 1y, thereby closing the valve :head 941 against its here. The trapped air then forms a cushion whereby the travel of piston l9is retarded and finally checked without detrimental impact.- As thepiston l9 returns to normal position, the stem [85 returns to normalposition in stem 92, and

valve94 moves toopen position under influence of 1 spring 91'.

Devices ofthis character are especially'useful for heavy Diesel engines, but maybe used on various other types with satisfaction. The mechanism is relativelyinexpensive, easy to apply, substantial and will operate effectively for the intended purpose. v Having thus described my invention, what I claim as new thereinand desire to secure by Letters Patent is:

1. The combination with an engine having a starting shaft equipped with a clutch head with teeth'of the ratchet type, of an engine starting means comprising a revolubly mounted cranking shaft having "a clutch head formed with teeth of ratchet type opposedly faced to those of the clutch head first mentioned; said cranking shaft disposed coaxially of the starting shaft, said clutch heads being fixed on adjacent ends of their respective shafts and normally disengaged, and said cranking shaft being adapted to be shifted in its mounting from a neutral position toward the said starting shaft to efiectaone-way holding and driving connection between the said clutch heads for a starting operation, a common source of power for both the shifting and. rotating movements of .the cranking shaft, means for applying the power to effect a shifting of the cranking shaft, power actuated means for rotating the cranking shaft, for a starting operation, means operable to delay the application of power to the 7 means for rotatingthe cranking shaftuntil after. the cranking shaft has been shifted to engage the starting shaft, means for terminating the application of shifting power to the cr'anking shaft after rotation has begun, and spring means acting against the cranking shaft to shift it to neutral position when the driving connection becomes ineffective.

2. The combination with an enginehaving a starting'shaft provided witha clutchhead formed 1 with ratchet teeth, of an engine starting means comprising a revolubly mounted cranking shaft having a clutch head formed with ratchet teeth opposing those of the first mentioned clutch head, and adapted to be shifted. in its mounting to effect a one-way driving connection between operation, normally inactive means for rotating the cranking shaft for a starting operation, means for admitting a fluid pressure medium to said normally inactive means for energizing it, and means acted on by said pressure medium for moving the cranking shaft to operatively engage the teeth of the clutch heads; said fluid pressure admitting means being operable to delay the .ad-'

mitting of the pressure medium to the normally inactive means for rotating said cranking shaft the said teeth of the clutch heads for a starting until after the latter has been shifted to engage the said starting shaft and also operable to terminate and to relieve the application of shifting "power to the cranking shaft after'rotationhas begun; and means acting against the cranking comprising a cranking shaft revolubly mounted and axially shiftable in its mountingbetween neutral position and a position at which it effects an operative connection with the crank shaft for starting the engine, a cylinder reciprocally containing one end of said cranking shaft therein as a 'piston, a powercylinder, a piston in the power cylinder, means connecting the latter piston with the cranking shaft whereby a power stroke of the piston effects rotation of the cranking shaft; a source of' pressure medium. and a distributing valve device through which said pressure medium -may be administered to'the cylinders to move the pistons therein to give the cranking shaft a rotating impulse and to shift the same axially to effect a starting connection with the engine shaft, means operable automatically to shift the cranking shaft to neutral position when the cranking impulse becomes ineffective; said distributing valve comprising a valve member operatively connected with the cranking shaft for rotation there by, and operable incident to rotation, to effect the exhausting of pressure medium from the sec- 0nd mentioned cylinder after cranking connection has been effected.

4. In combination, an engine crank shaft having a clutch jaw, an engine cranking'shaft axially alined therewith and having a clutch jaw at its inner endadapted to be engaged withthe clutch jaw of the crank shaft to effect a releasable cranking connection, a power cylinder having a piston, means operatively connecting the piston with the cranking shaft whereby an outward travel of the piston will rotate the cranking shaft for starting the engine, a cylinder operatively containing the outer end portion of the cranking shaft as a piston, a distributor valve having a connection with a source of pressure medium and also separate connections therethrough with both of said cylinders whereby the pressure medium may be administered to both cylinders; said connection through the distributing valveto the cranking shaft cylinder being normally open and unrestricted and adapted to be closed to the source of pressure and subsequently opened to atmospheric pressure, and the said connection to the power cylinder being normally in a restricted condition to delay the application of pressure'rnedium to the power cylinder to allow the cranking shaft to move axially toward vthe engine crank shaft to effect a cranking connection through their respective clutches before the power piston is actuated to rotate the cranking shaft, and means for exhausting pressure medium fromthe power cylinder for the return of its piston to" starting position, and yieldable spring actuated means for automatically returning the power piston upon the exhausting of the pressure medium! 5. The combination with an engine having a starting shaft, of a starting mechanism comprising a'revolubly mounted crankingshaft axially aligned with the starting shaft and axially shiftable in its mounting from a neutral position to a position at which its inner end effects an operative driving connection with the starting shaft, a piston on the outer end of the cranking shaft, a fixed cylinder within which the cra'nkingshaft piston is reciprocally mounted, a source of fluid pressure medium, a distributing valve mechanism comprising a housing, a valve member rotatable by the cranking shaft, a fluid connection between the source of pressure medium and the valve housing, a normally closeddouble action valve in the connection permitting the valve housing to be open to the atmosphere whenflclosed to the source of pressure medium, a fluid connection between the said valve housing and the cranking shaft cylinder, a port in said distributing valve member normally open to the connection between said valve housing and said cranking shaft cylinder providing for the application of, pressure medium. for shifting the cranking shaft, and-" maintaining said shifting pressure during rota- I tion of the cranking shaft, a second port inthe valve member adapted to relieve pressure within said shifting cylinderto the atmosphere before completion of the rotary motion of the said valvemember, an eccentric accelerating sheave fixed on the cranking shaft, a power cylinder having a reciprocating piston mounted therein, a cable connection between said'pistonand said eccentric accelerating sheave for starting the engine,"a

' fluid connection between the power cylinder and.

the distributing housing, and "a port in the distributing valve member partially restricting this connection but adapted to relieve this restriction as the cranking shaft is rotated, and a yieldable ,1

spring means for returning the power piston to its initial position upon relieving of the pressure in the cylinder through; the said double acting valve.

.KNUTE BERGER;

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