US2042616A - Automatic spark adjuster - Google Patents

Description

June 2, 1936. H. .1. DE N. M COLLUM 2042616- AUTOMATIC SPARK ADJUSTER Original F'iied Feb. 24, 1953 INVENTOR Henry J.eM Mc'6'oll um ATTORNEY Patented June 2, 1936 UNH'E STATES PATENT OFFIE Application February 24, 1933, Serial N0. 658,381 .Renewed. October 31, 1935 8 Claims.

'This invention relates 110 the automatic re-v tardation of the ignition spark Torinterna1 combustion cengines installed on road vehicles 01' m0- 1:0r cars of any description, and has for its 0bject the temporary production of such retardation whenever the vehicle is started. into motion from a condition of rast, 01' :has its existing rate of motion substantially accelera;ted 01 is being driven up a, grade, under all nf which conditions substantial reta;rdation of the moment of ignition 0T each .cylincler charge '0f fuel beyond tha.t at Whic'h the best results are Obtained. When running at uniform speed er under lighter loads, is desirable for smooth and. efficient operation of the engine, und for the avoidance of internal strains and overheating. The spar-k is also retarded when the engine is idling.

The best .form of apparatus embodying my invention, e 1t present kno-wn 130 me, anal sundry modifications thereof, are illustrated in -the accompanying sheet of drawings, in which,

Fig. 1 is a plan view '0f a portion of an interna;l combustion enginerand the circuit breaker for the ignition system there0f, with my invention applied thereto, cer.tain parbs being broken away and others shown in section.

F'ig. 2 is a similar side elevatian, 0n a smaller scale.

Fig. 3 isa view of a modification,

Fig. 4, is a detail of another modification, 'and Fig. 5 shows the invention applied to another form o'f ignitiom device.

Throughout the drawing like r.eference characters indicate 'like parts.

In all =the figures 0f the drawing, the numeral l indicates the cylinder block of a standard for-m of motor for automobile construction, the n-umeral 2 is the intake manifold, andthe numeral 3 is Ehe carburetor therefo-r. 'Ihe carburetor 3 has the usual throttle valve sha;ft 4, carrying stop arm 5, yieldingly forced towa;rd stop 5m, so placed. as to hold throttle valve in idling p0sici0n, loy tension spring 6, anchored a't 1, andmanuall5 controllecl by a lost-motion linkage 48 extending 130 accelerator pedal 9, normal'ly retracted b-y expansion spring 10 confined betWeen it a nd the footboard. H.

A standard form of ro'tary circuit breaker o1 spark timer for the= ignition system having the cylindricl casing 29 is shown in Figs. 1 110 3 0f the drawing. In the interior of said casing are pivoted at 23, 23, two circui't breaker arms 23, 24, carrying bear'ing lugs 28, 28, cooperating with multiple cam 21 secured 130 a shaft 22 geared to rotatewith the engine crank-sha'ft. These breaker (C1. ISO-77') arms 24, 2G, are electrically co'nnecoed. m the bindlng post 26, while the fixed. contacts 21., 21, with which they cooperate, are grounded. The springs 25, 2'5, normally hold the 2irms 24 against contaccs 2'l' until the cam 2| momentarilyseparates the points one after the other and breaks the circuit, thereby producing the spark for ignition of each cylincler charge. 'Ihe casing 29 is loosely journaled on cam-shaft 22, which rotates in a clockwise direction as indicated -loy the arrow in Fig. 1. The casing and circuit breaker arms 22 carried therein are prevented from ro-ta;ting by rod !9 pivc-tesl at one end to the external Casing Ing, o1 lever arm 2B, and ab ehe ooher end anchored in any desired way in a position which Will properly time the moment of each breaking of the circuit ancl consequent spark production. If the lug is movedslight'ly in a clockwise direction, looking a1; Figs. 1 and. 2, so that the diametr'ical line I1I.17 is .moved to position x -ac the spar.k will be retared 110 that angular extent:

In p-ractically all modernmotor cars the spark timing is automatically controlled by a cen trifu'- gal or other governing mechanism geamed. to the engine, so that the spark is automatically ad.- vanced by rotating cam in a clockWise direction With respect so its axis more 01 less as the speed of revolution of the ehg1'ne crank-shaft increases. Under usual conditlons of operation the standard 4-cycle gas engine performs most efficiently with an ad.vance of the: ignition spark a number of degrees beyond the crank dea.d center. When starting, sharp'ly accelerating 01' lugging, (i. e. laboring ab very 10W sp'eed on high gear) with a heavy 1oad 0 :1 the engine, however, ehe spark must be somewhat less advanced. These conflicting requirements, which sometimes arise at the same engine speed, have made it impmcticalole 1:0 sei; the centrifugal governing mechanisms so aus 130 p-roduce ab theirminimum operating speed the amount o1 spark advance best suited for the first dass of conditions, such as the moderate running a1: a moderate speed a.long a level road with a lightly loaded. cm, because When the car is heavily loaded, or is going upgrade, or both, anal is running at the same speed, the spark should. be much less advanced. Consequently, the standard apparatus governed .by engine speed and now used 1:0 automatica-lly ad.- just, or time, the ignition spark are all set co produce a predetermined minimum spark advance which is too slight to p=r0duce highest efficiency under ordinary conclitions of running 011 a. smooth, level road, anti this has to be done 130 avoid an excess spark advance when starting, accelerating or lugging.

My invention, hereinafter to be described more in detail, can be used With, and a-s supplementary to, the said standard automatic speed actuated spark control, in that it automatically retards the spark when the car is started, accelerated, or driven uphill and that this is done independently of any contemporaneous speed responsive adjusted governor control.

With approximately uniform load conditions,

the spark should (generally speaking) be advanced proportionately to the engine speed, as every motorist knows, and the centrifugal gevernor fulfills this requirement, but has tobe set for level road conditions and does not compensate for any considerable increase in load at a given speed, such as occurs when a car is being driven up a. steep grade. When climbing a hil1 ehe throttle is opened wider, more combustible mixture is drawn into the cylinders for each cycle o1 operation, such larger Charge is more quickly und sharply compressed, and. the spark should be correspondingly retarded to prevent knocking, over-heating and straining of the motor, but I;he centrifugal, engine-driven spark controller always maintains the same spark advance for the same speed no matter what the load and throttle conditions. Also when the load on the engine is suddenly increased by throwing in the clutch on starting or shifting to a higher gear, the spark should be retarded sharply, but if the cantrifugal apparatus alone is in use, this retardation will not occur because it has been set to produce the greater angle of advance suitable for other conditions.

I have discovered that both o-f these difiiculties can be o-vercome if the extreme retardation of the spark so desirable under ehe above recited special conditions is automatically eifected by a device actuated by the combined influences of gravity and inertia, the simplest form of which is a smal1 pendulum connected to the'adjusting lug, or 1ever arm 26, of Ishe circuit breaker or ignition timer.

Referring to Figs. 1 anti 2, a pendulum weight I3 is there shown as suspended by rod I4 from shaft I2 journaled in the ears I6, I6, of the bracket I5, fastened to the top of the cylinder block I by screws 45, 45. Cross pins I'I, I'I, prevent shaft I2 from sliding endwise. The numeral I8 designates a. cra.nk arm projecting upward from shaft I2, and to which one end. of rod I9 is pivoted. The numerals 36 and 60 designate pins limiting the oscillations of pendulum rod I4.

This embocliment of my invention, shown in Figs. 1 and 2, operates as follows: Assuming that the car moves from right to left (as indicated by the arrow between Figs. 1 and 2) when running forward, the inertia of the pendulum weight I3 will cause it to lag behind when the car is started, or has its motion sharply accelerated; thus swinging the parts I 3, I 4, I8, I9, 26 into the broken line positions shown, and retarding the spark to the desired extent, until gravity has had time to pul1 the pendulum back to its normal position shown in fu1l lines. Similar1y, when the car is going upgrade, the pendulum swings toward the broken line position and stays there, thus retarding the spark more or less so long as the car is on an upgrade. As the spark must not be ret arded beyond the point corresponding to crank dead center, a stop, such as pin 60, must be provided to engage the train o1 mechanism at some point, either at the pendulum or at the timer, or at some intermediate point, to prevent; any such excess retardation. Also, as it; might not be advisable to have the spark abnormally advanced while going down hi1l, and certainly not when starting backvvards With the car, a second stop means, such as Ishe pin 36, should be installed to prevent the pendulum swinging too far to the left of its normal vertical position, shown in full lines. It is assumed, o1 course, that the usual centrifugally actuated timing device (not shown) operates an the cam 2I, or cam shaft 22, and that no manua11y operated control device for timing the spark is provided, the latter usually being omitted from modern pleasure car equipment.

In the arrangement shown in Fig. 3, the car is supposed to travel from left to right (as indicated by the arrow) When running forward, and an inertia device o1 the electro-magnetic type, (the details of which were not invented by me) is shown as another specific embodiment of the underlying principle of my generic invention. The body cf mercury 33 in the horizontally extending glass taube 32, supported 0n bracket 35, there serves as the inertia controlled element, taking I:he place of the pendulum hob I3 shown in Figs. 1 and 2. When the power clutch of the car engages and starts the car moving to the right, the mercury surges back to the left, anal bridges contacts 34, 36, thus completing circuit 3I through battery 38 ahd solenoid 31. The magnetic attraction then pulls core 39 into solenoid 3'I, expanding spring 4I, to which ehe core is connected by link 40. The lug, or lever arm 26, 01" the timer 29 is connected to this linkage ab any convenient point, and the spark is retarded accordingly. When the car is running at a. uniform speed on a level road I:he mercury 33 does not touch the contact, or short electrode '34, solenoid 31 is de-energized. and. spring ..4I pul1s the timer into its normally advanced. position. When the car runs up a steep hill, short electrode 34 is again immersed in the mercury and the spark is retarded as is desired.

Obviously, a, sliding weight, such as 53 (shown in Fig. 4), ha.ving an anti-friction mounting 54 on a, horizontal track 52, supported by a bracket 55 on any portion of the motor car, is the mechanical equivalent of the pendulum apparatus I3, I4, I2, shown in Figs. 1 and 2, for all purposes of this invention. Compression spring 56 would perform the function of keeping the weight in one position so long as the car is running ab a. uniform speed along a1evel road, just the same as gravity holds the bendulum I3, I4, in one position under similar conditions. starts, or accelerates, the inertia .of weight 53 would cause it to lag momentarily, thus compressing spring 56 and moving to the right along track 52. Thereupon, link II9, which should be connected to weight 53 a1: 51 and to 1ug I 20 on timer 23 (if this sliding weight were substituted for a swinging pendulum) would rotate the time r casing in the desired clockwise direction and automatically retard the spark momentarily as before.

When the lag caused by the weight inertia, has been overcome by spring 56 and the weight moved Also, when I;he car back to normal position (further acceleration of the car motion having ceased) the spark timing will return to normal. Also, whenever the car is driven uphill Weight 53 will tend to slide backward, compressing spring 56 more or less and correspondingly retarding the spark.

My inventi0n has been hereinabove described as applied to the older form of timer and dis- 75 tributor in which the entire casing 29 is rotated in one direction or the other to varythe degree of spark advance, laut in such c onstruction Izhe numerous wires (n0t shown) leading to the spark plugs and to the coil must be fiexed with every adjusting movement, thus requiring the pendu- 1um to do a considerable amount cf work. In Fig. 5, however, I have shown itas applled to a more modern form of spark adjusting and distributing apparatus in which the casing I29 is stationary, and on1y an internal plate (not shown) which carries the circuit breaker arms 24, 24, and cooperating contacts 2'I 2'I, rotates back ancl forth aber; shaft 22, being controlled for this purpose by lever arm 220 which projects radially from it through a s1ot 22I in the casing. The spark plug wires GI, GI, and the wire 62 so the coi1 then pass through the stationary cap 63 of casing I29 to the stationary contacts (not shown) of the stationary distributor head. The pendulum II3 of my invention can then be suspended from a pivot I I2 on the exterior of casing I29, ancl the pendulum rod. I I4 is provided with a s1ot I I8 through which the lever arm 228 projects. The pendulum then has 130 clo only the"work of rotating back anti forth the said light plate, which carries the circuit breaker arms and the coaperating contacts, and the apparatus is much more sensitive, thus permitting the use of a mueh lighter pendulum weight. Also, its operation is maintained uniform ab all times, being unaflected by variations in stiffness of the 1ead wires, such as might develop with age, or from readjustment of the wires such as might result from rewiring of the ignition system, etc.

II: will thus be seen that When my invention, in whatever form it is embodied, iscombinecl with the centrifuga], or other speed actuated, form 0f automatic spark adjuster, the resultant timing of the spark is a joint function of the two devices. If the engine is unloaded and running slow1y enough 120 cause the centrifugal apparatus to retard the spark to the minimum of which it is capable, and the clutch is thrown in, the pendu- 111m Will temporarily further retard the spark. If the car is running ab a speed such that the spark has been advanced a given number of degrees, and is suddenly accelerated, the pendulum will also momentarily further retard 117 to a greater or less extent according to the sharpness of the acceleration, and will thereafter gradually surrender all control of the timing to the centrifugal apparatus. If no centrifugal apparatus were employed, but the spark timing were manually effected, my invention would still automatically retard the spark during the desired periods above defined.

Various other changes cou1d be made in the details of construction here illustrated and described, and equally without departing from the underlying novel principle of my invention; which involves the use in some way of the inertia or weight of an element loosely mounted with reference to the running gear of a motor car, to automatioally retard the time of the ignition of the charge whenever the said element is suddenly put into motion, or accelerated in motion, or tl'1e car is driven onto an upgrade.

An additional automatic spark control which may be used in combination with my above described. invention, or independently thereof, is also illustrated in Figs. 2 and l. Referring to Fig. 1 another lug I20 is shown projecting from the other side of casing 29 and carrying a pin I49 projecting up through a s1ot 44 in a link 42,

which i s pivoteglab 43 I2o the accelerator linkage 8... The parts are so proportioned that after the retraction of the accelerator pedal 9 has allowed the t:hr0ttle valve to assurne idling position and the lost motion connection 48 in linkage 8 begins to open, the leih-band end of the s1ot 44 in link 42 will engage the pin I49, and the final movement of the aocelerator pedal 1:0 its position of rast will retard. the spark so zero position. This permits slow anti smooth idling and cons -zquentr economy of fue1. The abovedescribed serles o1" operations would also occur whenever the modifieol inertia element of Fig. 4 should be employed, wlth its rod. II9 conneeted to lug I20, as previously clescribed. When the accelerator peda1 is pressed down 110 open ehe throttle valve and the clutch has become sufficiently engaged to accelerate the motion of the car, the spring 56, or pendulum weight I3, first advanoes the spark to the normal position for which thecentrifugal governing device is Set, and thereafter the manipulation of the acoelerator has no effect on tl1e timing (because of the length of slot 44) unt'1l the parts again return to idling position. While the accelerator pedal is pressed' down to any extent suflicient to open the thrott1e valve beyond its idling p0sit-ion, pin I49 may then move freely in s1ot 44 without comi-ng in contact with either end thereof, so that the spark timing is thensolely under control of pendulurn I3 er slidingweight 53, which ever has been installed, together with the usual centrifugal governor.

Of course, in the modification shown in Fig. 4 the effeotive pull of spring I EI on lug. I2@ musi;

slightly exceecl the pull of the spring 55 in the oppositedireotion in Order 110 have the sparl: recarciation thus prod.uced by the pedal. 'When be car is started, or accelerated, or running uphill, however, the aecelerator pedal 9 will always be dep-ressed, so that the lost motion connection 44-I49 will release lug I20, and spring 56 and weight 53 will then have so1e control of the timer member 29, allowing the inertia or the gravitation of the weight 53 to properly retard. the spark during the starting and accelerating periods, or when hill climbing, in the desired manner before described.

Other means actuated by the pendulum, or equivalent inertia-controlled element, and. operative to retard the spark, might be substituted for the purely mechanical devices herein shown which mecham'cally s.hift the point in eaoh cycle of engine operation at which the circuit producing the spark is closed or opened, as the case may be.

Having described. my invention, I claim:

1. In a spark timing apparatus for a gas propelled motor car having adjustable ro'oary cirouit breakers normally sei; I;o produce the spark igniting the oylinder-charge somewhat in advance of the dead. center position of the crank cf the engine propelling said car, the combination of mechanism comprising an element of substantlal weight so mounted. on said. car as to be movable longitudinally thereof, with means actuated by said we-ight element operative to retard the spark whenever said weight element moves toward the rear of the said car; whereby, whenever the said car is started forward or has its motion in tha1; direction substantially accelerated, tne temporary lag in motion of said weight element will contemporaneously retard the spark.

2. A combination such as defined in claim 1 in which said weight element is a pendulum.

3. An apparatus such as defined. in claim 1 in Which said Weight element is slidingly mounted on a horizontal track combined with a, spring normally forcing said weight toward the fronl; of the said car.

4. An apparatus such as defined in claim 1 combined With means for preventing said weight element from moving far enough toward the rear of said car to retard the spark beyond the dea center position of the said engine crank.

5. An apparatus such as defined in claim 1 combined. with means for preventing said weight element from moving to any position that would advance the spark beyond the predetermined normal angle.

6. In a, spark timing apparatus for use on a. motor car having a throttle controlled carburetor delivering a combustible mixture to the intake manifold of the engine for propelling said car and an adjustable rotary circuit breaker normally set to produce the spark for igniting said mixture sornewhat in advance of the arrival of the crank of said engine at dead center position, the combination, with said above described apparatus of mechanism comprising an element; yieldingly mounted 011 such car and connected. to a sparktiming member of such circuit breaker, yielding means normally tending'to hold said element in a position which maintains such a normal spark timing, and means responsive only to sudden movements and acceleration of movement's of the car for automatically moving said element in a direction which will retard said spark; whereby such spark retardation is ensured wheneVer said car is started or accelerated in forward motion, or such carburetor throttle is brought to id1ing position.

7. In a spark timing apparatus for use on a motor car having a throttle controlled carburetor delivering a combustible mixture t0 the intake manifold of the engine which prope1s said car,

with a spring-retracted pedal controlling said throttle and an adjustable rotary circuit breaker having a member controlling the timing ofthe spark f0r igniting said mixture normally set to produce such spark somewhat in advance of the arrival of the crank of said engine at dead center position, the combination, with said above described apparatus, of a lost-motion connection from such pedal to sald spark-timing member and mechanism comprising an element yieldingly mounted on such car and connected 150 said sparktiming member of such circuit breaker, yielding means normally tending to hold seid element in a position which malntains such a normal spark timing, and means responsive only 130 sudclen movements and acceleration of movements of the car for automatically moving said element in a direction which will retard said spark; whereby such spark retardation is ensured whenever said car is started or accelerated in forward motion, or such carburetor th'rottle is brought to idling position.

8. In a spark timing apparatus for a motor car having an internal combustion engine for propelling it and. an acljustable rotary circuit breaker normally set to produce the spark igniting the cylinder charge somewhat in advance of the deadcentre position of the crank of said engine, the combination of mechanism comprising an element; so x'n0unted on said car as to be movable longitudinally thereof, with means actuated by said element and operative 120 retard the spark whenever said element moves toward the rear of the said. car; whereby, whenever said car is started forward, or has its motion in that direction substantially accelerated, the temporary lag in motion of said element will contemporaneously retard the spark.

HENRY J. DE N. MCCOLLUM.

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