US1466470A - Combustion engines - Google Patents

Description

Aug. 2a, 1923. 1,466,470

E. DODSON APPARATUS FOR CONTROLLING'THE IGNITION PdINT IN INTERNAL COMBUSTION ENGINES Filed April 15 1922 3 Sheets-Sheet 1 mam Aug. 28, 1923.

' E. DODSON APPARATUS FOR CONTROLLING THE IGNITION POINT IN INTERNAL COMBUSTION ENGINES Filed April 15 1922 3 Sheets-Sheet 2 .AITTORNEY MTNESSES Aug. 28, 1923. 1,466,470

E. DODSON APPARATUS FOR CONTROLLING THE IGNITION POINT IN INTERNAL COMBUSTION ENGINES Filed April 15 1922 3 Sheets-Sheet 3 IN NTOR WITAESSES umi 014m,

ATTORNEY Patented Aug. 28, 1923.

UNITED STATES PATENT OFFICE.

EDWARD DODSON, OF LONDON, ENGLAND.

Application filed April 15, 1922.

To all whom it may concern:

Be it known that I, Enwinu) DODSON, a subject of the King of England, residing at London, England, have invented certain new and useful ln'iprovements in ripparatus for Controlling the Ignition Point in Internal-Combustion Engines, of which the following is a specification.

My invention relates to apparatus for controlling the ignition point in internal combustion engines, of the kind in which the suction effect of the engine is employed to advance the point of ignition against the action of gravity or a spring tending always to retard the ignition.

It is the object of the invention so to con trol the spring effect relatively to the suction effect that the apparatus may be as sensitive at the open position of the throttle (when the changes of induction pressure are relatively slight), as at the partly-closed or closed position when they increase in magnitude.

According to this invention, means are employed to decrease the suction eflect relatively to the gravitational or spring effect as the engine throttle is closed and vice versa, and these means may comprise either a lever (or asystem of levers), the moment of which is variable by the agency of a member displaceable along the arm of the lever to or from its fulcrum (or this displaceablemember may itself form the fulcrum), and actuated by the movements of the engine throttle, or, inasmuch as the closure or partial closure of the throttle valve produces a corresponding depression in the induction pipe, additional suction-operated apparatus may be employed to vary. the position of the lever fulcrum, instead of actuating it by a connection with the throttle valve. )Vith either arrangement the lever, which is operatively connected to the ignition member, tends to turn in one direction under the action of the engine suction, and in the opposite direction under the act-ion of a spring or the like, and themovement of the throttle or the action of the additional suction device acts positively to weaken the moment of the spring, (or conversely to increase the moment of the main or primary suction device) when the throttle is fully open, and vice versa, when it istclosed.

The manner of carrying out the invention IN INTERNAL-COMBUSTION Serial No. 553,280.

is illustrated diagrammatically by the accompanying drawings in which Figures 1 and 2 illustrate a construction in which there is an operative connection between the throttle valve and the movable fulcrum of the lever, Figure l shewing the relative positions occupied by the several parts when the throttle is closed (or nearly so), while Figure 2 shews the positions occupied when the throttle is fully open. Figure 3 shows a modified construction in which the operative connection of the throttle and movable fulcrum is replaced by additional suction apparatus, the arranlgemcnt otherwise being as in Figure 1, anc

Figure 4, to a smaller scale than the fore going, shews the application to an engine or the apparatus shewn in Figures 1 and 2.

The ignition device shown at A is pro vided with the usual advance and retard mechanism A connected by a hinged link A with a lever B pivoted at B to a fixed member such as a part F carried by the engine to which the invention is applied. A tension spring 13 anchored at one end to a convenient fixed point F and at the other end connected to a flexible strip or the like 13 attached at B to a curved part l3 of the lever B, ensures a substantially constant leverage of the spring throughout the range of movement of the lever B.

In the position shewn in Figure 1, the ignition is in the fully advanced position, and the spring B acts continually to retard it. This action is opposed by the suction effect in the induction pipe F at a position between the closed throttle F and the cylinders F, such effect being transmitted by way of a conduit C to a bellows C anchored at one end C to a fixed part, and at the other end C connected by a hinged link C with a lever D fulcrumed at D to a fixed member. The lever D is arrangedside by side with the lever B, and interposed between them is a roller E, preferably divided into three separate rollers located side by side the middle one E as shown by the broken line being slightly smaller in diameter than the outer ones so that it engages the lever B only, while the outerrollers engage the lever D only, which is there thickened sufficiently to permit this. The roller is thus engaged by the respective lewhich the roller E occupies relative to the rcspectivelulcr' B and D and the amount of suction pertaining; at the time. Accord ingly, therefore, this roller is mounted at the end of a link E which is operativel connected with the hand control lever F of the throttle valve F located in the induo tion pipe F As it is desirable that the movement of the roller E away from the tulcra B and D should be relatively small at the nearly closed position or the throttle, but should continually increase in magnitude as the throttle F is opened, a toggle system oi? linkage is employed to effect this, comprising the bell/crank lever G (pivoted to a fixed part) of which one arm G is substantially parallel with the throttle arm F upon the throttlevalve'F, and is connected with it by a link G The other arm G of the bell "crank le'verconstitute's with the link 13* the toggle mechanism, being substantially in line withit when the throttle is closerhbut approaching or reaching a position at right angles to itjwhen the throttle is fully opened, Thus it will be'evident that movement of the roller E acting to reduce the spring effect will be very, slight while the throttle is partly closed, but will be considerably greater when the throttle is fully opened, and consequently (the suction pressure is relatively small, the mechanism ensuring that at this position the spring B shall ,haveits least effect, or conversely, that the suction shall have its greatest er'iect.

To enable independent adjustment of the position of the roller E to suit particular types of engines and to effect this it necessary while theengine is running, the link f has a threaded connection at E with the member by which it is hinged to the arm G of'the bell crank lever G, any known or convenient ari'a1'1geinent being provided to ensure that its effective length is varied when it is rotated. Furthermore to facilitate starting and to ensure a correct location of the ignition device for this purpose, a notch maybe provided at B in the lever B so that the roller E will readily engage the notch, and thus ensure the correct position. The engagement oft-he rollerwith both levers B and D is at all times ensured by the spring action and the suction etl'ect which act in conjunction with one another to thrust the respective levers against the roller from opposite sides of it.

The use of the bellows C avoids frictional losses and/or leakages which are liable to arise if a cylinder and piston are employed, and it also tends thereby to render the apparatus more sensitive to changesofpressure.

The disposition of the parts as shown in Figure 2 will be clearly understood from the toregoii'rgdescription of the apparatus, and it will be partlcularly noticed from this arrangement that although some change of leverage takes place with the lever D by reason of the movement of the roller E, is comparatively slight ascoinpared with the changes of leverage of the'lever B. If through reduction of load any increase of suction occurs with the throttle 't'u open, the increased suction will act to overcome the force of the spring B and will advance the ignition as is desirable, while any closure oi the throttle, while it acts to move the roller nearer to the fulcra of the levers B and D, will also at the same time product-i a decrease of the suction effect which is tending to overcome the spring B and to advance the ignition too much. i

From the foregoing description, the modi li'cation illustrated in Figure 3 will be read ily understandable, inasmuch as the only changes are in the Ina-line of controlling the position of the roller E. For this pur- 'a link H extending troni'the movahlelwail H of a bellows H constituting theadditionai or supplementary suction device. This latter hasits fixed wall at H and from this a conduit H extends to the induction n it :2

to secure by Letters Patent of the United States is 1. In an internal combustion engine, the combination with the induction pipe and a throttle valve therein, of an ignition timingdevice, a suction ope'rated device communicating with the said i'nductionpipe 'so as to advance the said timing device with each increase ot suction, a lever system interposed between the said suction and timing devices, a spring arranged to oppose the suction advance, and means actuated by a variation in the position of the said throttle valve to vary the position of the fulcra of the said lever system.

2. In an internal combustion engine, the combination with the induction pipe and a throttle valve therein of an ignition timing device, an induction pipe, a suction-operated device connected with said induction pipe and adapted to advance said timing device with increase of suction, a lever actuated by said suction device, a lever connected with said timing device, a. displaccable member forming an operative connection between said levers and movable along them to vary their respective acting leverages, a spring adapted to oppose suction advance and means dependent upon the position of said throttle for varying the position oi said displaceable member connecting said levers.

3. In an internal combustion engine, the combination with the induction pipe and a throttle valve therein of an ignition timing device, an induction pipe, a suction-operated device connected with said induction pipe and adapted to advance said timing device with increase of suction, a lever actuated by said suction device, a lever connected with said timing device, a displaceable member forming an operative connection between said levers and movable along them to vary their respective acting leverages, a spring adapted to oppose suction advance, means dependent upon the position of said throttle for varying the position oi said displaceable member connecting said levers, and a toggle linkage system connecting said displaceable member with said means, adapted to produce an increasing degree of movement of said member as said throttle appreaches its fully open position.

In an internal combustion engine as claimed in claim 3, the combination with the displaceable member and the control means therefor, of an adjustable linl; adapted to vary the acting position oi said displaceable member.

5. In an internal combustion engine, the

combination with the induction pipe and a throttle valve therein of an ignition timing device, a suction-operated device connected with said induction pipe and adapted to advance said timing device with increase of suction, alever actuated by said suction device, a second lever side by side with the first-mentioned lever and connected to said timing device, a roller located between said levers and displaceable along them, a spring acting upon said timing device and said lever connected therewith to cause said lever to bear against said roller and hold it against the first-mentioned lever, and an operative connection between said roller and the aforesaid throttle valve whereby the leverage of said levers is varied in accordance with the movements of the throttle valve.

6. In an internal combustion engine as claimed in claim 5, locating the levers connected respectively with the suction device and the ignition timing device, so that when said roller is opposite the fulcrum of the ignition advance lever it is at a distance from the fulcrum of the suction actuated lever.

7. In aninternal combustion engine, the combination with the induction pipe and a throttle valve therein of an ignition timing device, a control lever for said throttle valve, a bellows, a conduit connecting said bellows with said induction pipe at a point between said throttle valve and the cylinder of said engine, means for connecting said bellows with said ignition timing device, adapted to advance said timing device with increase of suction, said means comprising two levers pivot-ed side by side, one connected with said bellows, the other connected with said timing device, a roller located between said levers and displaceable along them adapted to vary their effective leverages, a spring acting in opposition to the suction of said bellows upon said timing device, tending thereby to retard it and also to compress said displaceable roller between said levers, a toggle link system connecting said roller and said throttle control lever, adapted progressively to increase the roller move ment along said levers, as the throttle is opened, and vice versa, means for adjusting the position occupied by said roller at any given throttle position, and a notch in the lever connected with said timing device, located opposite the pivot of the lever con nected with said bellows, constituting a location for said roller when said throttle valve is in its closed position.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

EDWARD DODSON.

\Vitnesses:

STANLEY WV. HUGHES, A. I. ORUMP.

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