US888794A

US888794A - Starting means for gas-engines.

Info

Publication number: US888794A
Application number: US31578706A
Authority: US
Inventors: David Fergusson
Original assignee: GEORGE N PIERCE Co
Current assignee: GEORGE N PIERCE Co
Priority date: 1906-05-08
Filing date: 1906-05-08
Publication date: 1908-05-26
Anticipated expiration: 1925-05-26

Description

No. 888,794. PATENTED MAY 26, 1908.

D. FERGUSSON STARTING MEANS FOR, GAS ENGINES.

APPLICATION FILED MAY 8,1906.

Z/ L Znesses Y Y cfiahdfia, mlwvenlan UNITED sTA'rEs PATENT OFFICE.

DAVID FERGUSSON, OF BUFFALO, NEW YORK, ASSIGNOR TO GEORGE N. PIERCE COMPANY, OF BUFFALO, NEW YORK.

Specification of Letters Patent.

Patented May 2c, 1908.

Application filed May 8, 1906. Serial No. 315,787..

T 0 all whom it may concern:

Be it known that 1, DAVID 'FERGUSSON a subject of .the King of Great Britain, residing atBuffalo, in the county of Erie and State of New York, have invented a new and useful Improvement in Starting Means for Gas- Engines, of which the following is a specification.

In starting internal combustion or explosive gas engines it is ordinaril necessary to turn the crank shaft by han to draw a charge of fuel into the engine cylinder and compress it reparatory to theautomatic operation of t e engine. If the normal comression is not relieved in the cylinder durmg the compression stroke of the piston, great exertion is required to turn the crank shaft by hand and the operator is liable to be injured in the event of premature firing of the fuel charge and consequent sudden and violent backward rotation of the engine shaft. It has heretofore been customary to open the exhaust valve to relieve the compression when starting the engine, but

has usually been accomplished by actuatingsome device before turning the engine shaftand as aseparate or distinct operation from turning the shaft.

The primary object of this invention is to provide means' offvery sim le, desirable and efficient construction, ca a le of easy operation, for both relieving t e compression and turning the engine shaft by the movement of a single startinglever or device.

Other objects of the invention are the pro vision of simple means which will connect or couple the starting device to the engine shaft when the former is moved in the operative direction and will automatically release the engine shaft upon the return of the starting device to the initialposition to prevent. noise and wear of the parts during the running of the engine, .and also to prevent possible injury to the operator or to the starting mechanism in the event of the back firing of the engine; to especially adapt the starting device to multiple cylinder engines with a view to making the device of the minimum number ofparts and ofvery simple and inexpensive construction.

Still another object of the invention is to provide means for the purpose stated of the desirable construction hereinafter described and set forth in the claims.

In the accompanying drawings: Figure 1 is a side elevation, partly insection, of an engine equipped with starting means embodying the invention. Fig. 2 is a fragmentary sectional elevation thereof in line 22, Fig. 1. .Fig. 3 is a plan view, artly in section, of the starting device and associated parts. Fig. 4 is a fragmentary sectional elevation of the cams for one exhaust valve, the cam shaft and shaft shifting device, showing the parts in the shifted osition. Fig. 5 is a transverse sectional e eva tion of the cam shaft and one pair of cams. Fi 6 is'a detail sectional elevation, on an en argedscale, of the spring device for returning the camshaft to normal position after it has been shifted by the starting means.

The starting means forming the subject matter of this invention is shown in the drawings and will be hereinafter described'as appl ed to an explosive gas engine of the fourcycle type havmg four cylinders and pistons, one of which stons produces a working stroke for each half revolution of the engine shaft. Each 0 linder has an exhaust valve and the severe exhaust valves are actuated by a corresponding number of cams or operating devicesdriven by the engine. Beside each exhaust cam is a second or relief cam or operating device which is driven by the engine but is normally in an inoperative relation to the exhaust valve. By shifting the camsor devices the relief cams or operating'devices are brought intoo erative relation to the exhaust valves, so t at when the engine shaft is turned the valves will be opened in the proper sequence to relieve the compression in the cylinders in the com ression strokes of the pistons. A starting ever or device is provided and means which, when the lever is moved in one direction, couple or connect the lever to the engine shaft and turn said shaft, said means automatically releasing the shaft when the starting lever or device is released or returned to its normal position. When the starting lever or device 1s moved to turn the engine shaft it. actuatos means for shifting the valve operatin cams or devices to place therelief cams or evices in operativerelation to the exhaust valves during the j first portion of the o erative movement of the starting lever an before the engine shaft is turned, so that the exhaust valves will be opened andthe comression in the cylinder or cylinders relieved liefore the pistons commence their compression strokes, The invention is not necessarily restricted in application to a multiple cylinder four-cycle engine such as described.)

Like letters of reference refer to like parts in the several figures.

A A A A re resent the four cylinders of the engine, a t e casings of the exhaust valves therefor, one of which exhaust valves .is shown at a, and a the rods or parts for lation to the lifting rods or parts for the exhaust valves of the respective cylinders A A A A Thecams c are differently positioned" on thecam shaft and the latter is driven in any suitable manner, for instance, by gear wheels (1 d, from the engine'shaft B at the proper speed to operate the'several exhaust valves in theproper sequence. These parts 'of the engine may be of any usualior suitable construction. Their operation is well known. The other parts of the engine which are not necessary to an understanding of the invention are not shown or; described.

The cam shaft C is referably j ournaled so as to he ca able of sli ing endwise and is provided besi e the several exhaust came with relief cams orv operating devices E for the exhaust valves. The exhaust and relief cams c and E canbe separate parts separately secured to the cam shaft, or they ean be formed by properly shaped portions on a single integral part. in the normal position of the cam shaft, shown in his. 1, the err-- haust cams are operative relation to, .or op osite to, the lifting rods for the exhaust va yes, and the relief cams are held in an in 1liperativi-r position to one side cf the valve ting rods so to turn p'astrthe same with out actuating them. By shifting the cam shaft endwise slightly, the relief cains'are placed'in operative position opposite to the Valve lifting rods without moving the ex:

haust cams out of operative position, see Fig;. 4, so that the exhaust cams'will 0 en the valves for the exhaust strokes and t e relief cams will open thevalves for the compressionstrokes ofthe pistons. 1

Any suitable means may be employed for holding the exhaust cam shaft in its normal position and returnin it to this osition after it, has been. sln. cams inoperative position. The means shown in'the drawings, see Figs. 1 and 6 consist of a coil spring F arranged in a spring pocket fsecur'ed to the engine casing oppositeone end of the exhaust cam shaft, and hear-in. at one end against a plunger j which. is confined in the sprin poclret and to place it e relief automatic operation of the as event of the bash firing ofthe engine the spring F b the starting mechanism, as will be resent y described.

' re resents the starting device, preferably, t ough not necessarily, consisting of a lever fulcrurned' on a stud or pivot gsecured to the engine casing eccentricallywith reference to the engine shaft. Secured to the engine shaft adjacent to the startin lever is a wheel, preferably a ratchet whee formed by integral teeth on the fly-wheel b of the engine. A pawl or clutch device I is carried by the starting lever and is adapted in the movemeat of said lever in one direction to engage the teeth of the ratchet wheel H to turn Bald wheel and the engine shaft. The pawl shown is pivoted to the starting lever. and is in Fig. 2, the paw is held I) itsxstbp i out of enga ement with the teat of the ratchet whee As the starting lever is fulcrumed eccentrically with reference to the engine shaft, when it is moved in the forward or operative direction, that is, upwardl in Fig... 2, the pawl will approach the whee and come in contact with one of the teeth thereof, as indicated by dotted lines in said Fig. 2. In the continued movement of the starting lever the pawl will 1yield a ainst the action of its spring and 'wil be held by said sprint in enga 'ement with a tooth of the ratdhet whee so that the latter will be'turned by the lever. in the return movement of the starting lever the pawl willbe held by its springagainst the teeth of'the ratchet wheel until it strikes its stop 11 and is thereby caused to recede from the teeth of the ratchet wheel in the remainder of the return movement. of

the starting lever. Thus by one or more quick forward movements of the starting lever the ratchet wheel be engaged and turned sufficiently to start the en e, and upon each return movement of thed e irer the pawl will be automatically moved out of engagement with the ratchet wheel soa's to permit the latter to turn forwardly with theengme shaft by reason of its momentum, orthe In the pawl will leave the ratchet wheel: and free the-starting lever therefrom before itreaches the limit of its return movement, and thus a stop stud or projection Ill ice

Jilin the valve lifting rods by the com a gift.

injury to the starting mechanism or to the operator is prevented." The starting lever is preferably returned to the initial position by a sprin K connected to the lever and to any suitab e stationary part k of'the engine, and is arrested in the initial position by striking an suitable etc or part Won the e ine. T e' .lever is a so preferably vi ed with a handle or operating device anytconvenient or desired form which may extend to any convenient oint for operation, for instance,- to the vicinity of the seat of an automobile, where the starting device is applied to the engine on an automobile.

e starting means are above described as comprising a lever fulcrumed eccentrically with'reference to the engine shaft and rovided with a pawl for coo eration wit a ratchet wheel secured to t e engine shaft, but manifestly the operating device or lever could be differently arran ed and provided with different means for re easablycou )ling, clutchin or connecting it with a di erent sort of w eel or part secured or connected to the engine shaft, so that the wheeler part will be engaged and actuated to turn the engine shaft when the startin one direction and-to re ease or free the wheel or part when the operating device is moved in the opposite direction, and the invention is not limited to the articular coupling or connecting means for, t is starting device and en ineshaft above described.

he cam shaft is shifted. lengthwise to place the relief cams in operative relation to a part or device actuated by the starting ver or device duringthe first ortion of the operative movement thereo Different devices may be employedfor this purpose. The device shown in the drawings consists of a bar or 'wedg'e L pivoted to the starting lever and havingan inclined or'cain face I, see Figs. Sand 4, adsated to engage the end of the cam shaft C. 1 en the starting lever is moved in the forward or operative direction, this cam face slides against the end of the cam shaft and shifts the latter endwise in its bearings against the action of its returning spring F. The shifting bar is preferably curved concentrically with the pivot of the startin lever'and passes through a slotted guide 1 by which it is held opposite to the end of the cam shaft. The uide l shown consists, of a hollow cap-or bus in surrounding the end of the cam shaft an secured in the bearin' boss or lug l on the casing for mechanism areso proportioned and role that the inclined face of the shifting bar will enlgofe and shift the cam shaft to place the re 1e came in operative relation to the exhaust valve lifting rods before the pawl or clutch device engages and'tiirns the starting wheel 'and'en'gine shaft, so that the exhaust device is moved in" devices for said valve one of w The parts of the start' {E 5. The combine valves will be opened and the compression relieved. inthe c 'linders before the pistons are moved in their compression strokes.

In starting the'engine it is only necessary for the operator to pull the handle of the starting lever G up one or more times. During the first-portion of the movement of the starting lever, the cam shaft C will be shifted and the relief cams E placed in operative 'relation to the exhaust valve lifting rods and thereafter during the same movement of the handle and levertlie. starting wheel H will be engaged and the engine shaft turned.

l/Vhen the engine starts the handle is re- Y leased and the parts of the starting mechanismpermi-tted to return to their inactive or rest' position.

I claim as my invention:

1. The combination with an engine having a relief valve, of a rotatable operating .device for said relief valve which is driven by the engine and is normally in an inoperative relation to saidrelief valve, means for start- M ingthe engine, and a device which is connected to said starting means and is moved ,thereby transversely with respect to said operating device for moving the same axially into operative relation to said relief valve, substantially as set forth.

2. The combination with an engine having a relief valve, of a rotary operating cam for said relief valve which'is driven by the engine and is normally in an inoperative relation to said relief valve, means for starting the engine, and means moved by said starting means transversely with respect to the axis of said cam for shifting the cam axially into operative relation to said relief valve, I

substantially. as set forth.

The combination with an engine having an exhaust valve, a rotar cam for actuating the same in the nornia operation of the en ine, of a part on said cam 'WlllCll is normally in an inoperative relation to the valve, means for startin the engine, and awcdge moved transverse y of the axis of said cam by said starting means for shifting said cam axially to place said part thereof into operative relation to said valve, substantially as set forth.

4. The combination with an engine having an exhaust valve, of two rotary operating ich is normally in an operative relation and the other and a wedge which is moved by said starting means transversely of the axis of said rotary devices for shifting said second operatin device axially into operative relation to sai valve,'substantially as set ,forth'.

tion with an engine having an exhaust valve, of two rotati cams driven by the engine and one of whic is normally in an inoperative relation to said ox-" haust valve, means for startin the engine, and a wedge moved transverse v of the'axis of said cams by said starting means for shifting the inoperative cam axiallv into o erative relation to said valve, substantial as set forth.

6. The combination with an engine having an exhaust valve, of a cam shaft, two cams on said shaft, one of which is normally in an inoperative relation to said valve, means for starting the engine, and a wed e which is movedtransversely of said earn 5 iaft by said starting means for shifting said cam shaft endwise to place said ino )erative cam into operative relation to sai valve, substantially as set forth 7. The combination with an engine having an exhaust valve, of an endwise movable cam shaft, means for yieldingly'holding said shaft in the normal position, two cams on said shaft, one of which 1s normally in an inoperative relation to the exhaust valve, means for starting the engine, and a wedge moved transversely of said camshaft by said starting means for shifting said shaft. endwise to lace said inoperative cam into operative reliition to the exhaust valve, substantially as set forth.

8. In a multi le cylinder engine having an exhaust valve or each cylinder, the combination ofa cam shaft, a pair of cams on said shaft for each of said valves, one of the cams for each valve being normally in an inoperative relation to its valve, means for starting the engine, and a wedge which is moved transversely of said cam shaft by said starting means for shifting said shaft endwise to place said'inoperative cams into operative relation to the several exhaust valves, substantially as set forth.

9. The combination with an engine having an exhaust valve, of a cam shaft, two cams on said shaft for operating said exhaust valve, one of said cams being normally in an inoperative relation to said valve, means for startin the engine, and a bar having an in clined ace which is moved with said starting means for shifting said cam shaft to move said inoperative cam into 0 erative relation git-I11 said exhaust valve, su stantially as set ort 1.

10. The combination with an en 'ine having a rellef valve, of an o crating device for said relief valve which is riven by the engine and is normally in an inoperative relation to said relief valve, a starting lever for the engine which swin s toward and from said valve-operating iievice, and a device which moves with said lever and shifts said operating device in a direction transversely of the plane of movement of said lever to place the operatin device in operative relation to said relief va ve, substantially as set forth.

11. The combination with an engine having a shaft and a relief valve, of a cam which is driven by said engine and is normally in an inoperative relation to said relief valve, .:1 starting lever pivoted to swing transversely of said engine shaft, clutch mechanism operated by said lever for turning said engine shaft, and a wedge connected toand operated by said starting lever for shifting said cam into operative relation to said relief valve,-substantiall v as set forth.

12. In an engine, the combination of a starting wheel, a starting lever fulcrumed eccentrically with reference to said wheel, a clutchin device which is carried by said lever &I1( is moved by said lever into enga e- 'ment with said wheel, and a sto on said ever for limiting the movement 0 said clutch device toward said wheel and for moving said clutch device out of engagement with said wheel when said lever is moved in one direc-' tion, substantially as set forth.

13. In an engine, the combination of a starting ratchet wheel, a starting lever fulcrumed eccentrically with reference to said ratchet Wheel, a pawl carried by said lever and pressed toward said ratchet wheel, and a DAVID FERGUSSON. Witnesses:

CHARLES W. PARKER, C. B. lIoRNnscK.