US1139255A - Dual ignition system. - Google Patents

Description

A. P. BRUSH.

DUAL IGNITION SYSTEM.

v Amlcmon man ma. 2|. 1912.

Patented May 1l, 1915.

A. P. BRUSH.

DUAL IGNITION SYSTEM. APPucATmN FILED 11111.21. 1912.

1,139,255. Patented 111331111915.

A 111111111111 "HvvgvllVV ull e) ff/1 W AnANsoN .1. BRUSH, or DETROIT, MICHIGAN.

DUAL IGNITION' SYSTEM.

T all 'whom'z't may concern.'

j fBe i ,knoW-nthat I, ALANsoN P.,fBRUsn, a Vcitizen of the United States, .residing at Detroit, inthe county of Wayne and State of Michigan, have invented la certain new' and useful Improvement in Dual Ignition Systems, of which the following' is a' full,

clear, and exact description.

VThis invention relates to improvements in so-called dual ignition systems, and has for itsobject the provision of means whereby a multiple cylinder engine equipped with such a system may be started by the ignition of a charge 1n the proper-cylinder without the necessity of cranking or otherwise turning over the engine to produce the igniting ark.

SPA multiple cylinder internal combustion engine of four or more cylinders will (if the cylinders contain an explosive mixture) usually start itself by the ignition of the mixture in that cylinder, whose piston has last passed the explosion point in its cycle when the engine was stopped. The expression usually is used, because in a four cylinder engine, for example, the engine may possibly, though not ordinarily, stop with all of the cranks so nearly on dead center that it cannot be thus started. Or the explosive mixture may produce so weak an explosion, or the friction of the engine may be so great as to prevent this method of starting. Barring these exceptions, however, it isfeasible to start internal combustion engines of this type in this way regularly.

The present state of the art is such that it is quite customary to produce the electric ignition current which is distributed to the various cylinders, by means of what is commonly called a magneto,-the electric current when the engine is in normal opera- 'tion being produced by the power of the Specification Yof Letters Batent.

nppneafinnmed Maron 21, 191e. :fserima esseci'.

Patented May 11, 1915.

wherein 'the battery or starting current is used 1n connection with an entirely sepalirate apparatusfrom the magneto involving the use of-an `additional set lof spark plugs, additionalltransforming' coil `orcoils, and

an additional vprimary lcurrent commuta-tor or timer.

'The dual system is thus seen to be materially simpler than the double ignition system, but with -the construction ofthel dual system Within the limitations imposed by the =proper functioning ofthe magneto `and the-engine, an engine of four vor more cylinders may and frequently does stop in such position 'that the battery current cannot -besucoessfully usedjto produce a starting spark :in-the proper cylinder with the engine at rest.

This invention has to do with a means of correcting-'this defect, and making the dual system as surely able to produce a starting spark in the proper cylinder as can be done with the double system,the means for producing this result including, in this instance, a special coupling through which the engine drives the magneto,-the function of this coupling being to permit the magneto armature and with it the distributer shaft, which it drives, being rotated through a part of a revolution in a direction opposite to that in which it normally runs, and means within this coupling device to automatically restore the armature shaft and distributer shaft which it drives to their proper relation to the engine shaft which drives them, either before orafter the engine has started. In explanation for the necessity of doingthis, be it known that the engine may stop 1n such position that the primary current interrupter or circuit breaker on the magneto may bein the open position, in which case, without* special apparatus not usually provided, the primary circuit cannot be closed at all and no spark can be produced, or the engine may be stopped in such position that, although the circuit breaker is in closed position so that a spark can be produced, the distributer of the secondary or ignition circuit may be in such position that the spark will be produced in the wrong cylinder for starting, in which event the engine will be started in the reverse direction. Both of these possibilities are entirely eliminated, if the magd neto armature be rotated backwardthrough an arc greater than the open circuit arc of the circuit breaker, usually ap roximately ninety degrees, since by doing t 1s the pr 1- mary circuit, if open, will be closed, or 1f closed, will be opened. If the c1rcu1t be open, the backward rotation will close 1t, and upon the return of the armature to its normal relation, the circuit so closed will be opened and a spark produced, and since the distributer will be rotated at the same time into its proper relation, the spark will be directed to the proper cylinder, or, if the circuit be closed, the backward rotation will open it and the starting spark will thus be produced, and because of thebackward rotation of the distributer shaft will be directed to the proper cylinder for starting.

In the drawings, wherein I have shown one embodiment of my invention, Figure 1 is an end elevation of a magneto adapted to be employed in the dual ignition system,

` and equipped with the main feature of the invention; Fig. 2 is a side elevation of the same, parts -being broken awa-y and other parts being in section; Fig. 3 is a diagrammatic representation of a simple form of dual ignition system in which my invention is utilized.

Referring, first, to Fig. 3, it will be seen that the dual ignition system here shown includes two sources of current, namely, the magneto 10 and the battery 11. Either one of these sources may be connected by means of a suitable switch 12 in circuitwith an interrupter or circuit breaker 13 which is usually operated directly by the magneto shaft and the primary 14 of an induction coil or a step-up transformer. The secondary 15 of the coil is in this case connected directly to the movable member of a' distributer 16, which is operated by the magvneto shaft and at a predetermined speed relative thereto, the stationary contacts of the distributer being connected to the spark plugs 17 of the engine, the system here shown being adapted for a four cylinder engine. It will be seen, therefore, that with both the magneto and battery, the same coil, interrupter and distributing mechanism are employed, and hence to start the engine with which this system is associated, it is essential that the interrupter be opened, so as to interrupt the primary circuit, and that the movable member of the distributer be electrically connected to the spark plug of that cylinder in which the rignition should take place to start the engine in the forward direction. However, by my invention, I am enabled to accomplish this result, and to attain the object before mentioned, as will be seen by reference to Figs. 1 and 2, con# sidered in connection with the diagrammatic representation of Fig. 3.

In Figs. 1 and 2, 18v represents the magneto shaft, and 19 the driving shaft which is alined with the magneto shaft, and is to be associated with suitable mechanism by which it may be rotated at the proper speed with reference to the crank shaft of the engine with lwhich it is used. In connection with the magneto, I have illustrated in Fig. 2, in a rather conventional and simple manner, the circuit breaker 13, and the distributer 16 previously referred to,-the cam for operating the circuit breaker being mounted directly upon the magneto shaft, and the distributer arm (the rotating element) being mounted upon the distributer shaftA which is operated by the magneto shaft by two-to-one reduction gearing.

In order that the engine may be started by simply igniting an explosive mixture in the proper cylinder with the battery as the source of current, I provide between the drive shaft 19 and the magneto shaft 18, a flexible coupling which may be designated as a whole by the reference character 20, this coupling being of a nature such that it enables the distributer and circuit breaker (and incidentally the magneto armature) to be turned backward so that the battery primary circuit may be interrupted and a secondary spark produced in the right cylinder. The coupling includes a disk 21 fixed to the drive shaft 19, and a wheel 22 fixed to the magneto shaft 18 and provided with an outwardly projecting flange which surrounds the disk 21. The driving element between the disk 21 and the wheel 22, and hence between the drive shaft and the magneto (and the rotating elements associated therewith) consists of a spiral or volute spring 23, the outer end of which is connected by a pin 24 to the disk 20, and the inner end of which is connected by a pin 25 to the wheel 22. The spring 23 is so tensioned that under normal conditions and during normal operation, the drive shaft 19 and the magneto will substantially preserve their required relationship, but in order that the proper relative positions maybe maintained with certainty, an automatic latch is provided for connecting them, and holding them in proper relationship. As shown, this latch includes a radially movable dog or plunger 26 mounted withln a radial, socket of the disk 21. This dog has a conical outer end adapted to' be thrown by centrifugal force into a notch in the overlying ange of the wheel 22. With this flexible coupling just described, I am enabled to turn the rota-ry parts of the circuit breaker and the distributer backward or in the reverse directions to those in which they are normally operated, by simply turning the wheel 22, and after these parts have thus been turned a suiiicient distance, the tension stored in the coupling spring during such movement will cause the said parts and the armature of the magneto to be restored to, or substanlto the side of the magneto.- The segment 27 has a V-shaped edge'which may frictionally engage a V-shaped groove in the periphery of thewheel 22, so that the rotation of the segment through a suitable arc or part of a revolution when frictionally engaging the wheel 22 will cause the wheel 22 to be rotated. The segment may be turned in any desired manner. In this instance the shaft 28 is provided with acrank 30 which may be connected to any suitable operating mechanism which may be actuated by the operator. Ifvthe wheel 22 and magneto armature are turned by the segment 27 through a part of a revolution backwardly against the tension of the spring and then released, they will be quickly returned by the spring to their former positions. To limit the movement of these parts under the action of the 'spring relative to the drive shaft, the disk 21 may be provided with a stop stud 31 adapted to be engaged by a similar stud 32 on the wheel 22. Y

To render my invention effective, the cylinder in which ignition is desired to start the engine from rest must, of course, contain explosive mixture. This cylinder is the one whose piston has finished its compression stroke and started on what would normally be the explosion or working stroke. This cylinder will contain explosive mixture if the ignition apparatus be cut out of service just before the engine last stopped, so as to leave the charge in said cylinder unexploded; o r the cylinder may be primed by any suitable priming apparatus. If, now, the battery is connected to the transforming, interrupting and distributing parts of the system, and if the magneto shaft is turned backward until the interrupter, if previously in closed position, is opened so as to interrupt'the primary circuit, or, if previously in open position, is closed so that the subsequent forward movement of the armature shaft under the action of the spring will cause the opening of the circuit breaker and hence of the primary circuit an igniting spark. will be produced in the proper cylinder for starting the engine.

It will be understood that after the movement of the segment 27 during which the wheel 22 is frictionally driven by the seg- .ment, the latter is moved out of engagement with this wheel so that the armature may be driven in the usual manner by the with.

drive shaft and in proper'relationship there- Having thus described my invention, what I claim is: V

1. In a dual ignition system for a multiple cylinder engine,-two sources of current comprising a battery and a magneto, the latter having associated therewith a drive shaft adapted to be operated by the engine, circuit interrupting and distributing mechanisms and comprising, Vrotary members adaptedto'be driven by said drive shaft,

and a coupling between the drive shaft and said rotary members by which the `latter .may be turned relative to lthe drive' shaft when the engine is at rest to interrupt the batterylcircuit and direct the spark to the proper cylinder for starting the engine inv the forward direction. i

2. In a dual ignition system for a multiple cylinder engine, two sources of' current, comprising a battery anda magneto, the latter having associated therewith a drive shaft adapted to be operated by the engine, cir- `cuit interrupting, distributing and transforming mechanisms and including rotary circuit breaker and distributer membersyassociated with the magneto so as to be driven thereby, and a flexible coupling between the drive shaft and the magneto by which the latter may be turned backward and thence will be restored to normal position relative to the drive shaft, so that the circuit breaker and distributer will interrupt the primary battery circuit and direct the high tension current to the proper cylinder for r starting the engine in the forward direction.

3. In a dual ignition system for a multiple cylinder engine, two sources of current comprising a battery and a magneto, the latter having associated therewith a drive shaft adapted to be operated by the engine, circuit interrupting, distributing and transforming mechanisms including rotary circuit breakers and distributer members associated with the magneto so as to be driven thereby, and a ieXible coupling between the drive shaft and magneto including a spring which enables the magneto to be turned backward relative to the drive shaft when the engine is at rest, and thence quickly in a forward direction, so that bymoving the circuit breaker and interrupter, the primary battery circuit may be interrupted, and a spark directed to the proper cylinder for starting the engine inthe forward direction.

4. In a. dual ignition system for a multiple I magneto so as to be driven thereby, and a coupling between the drive shaft and the magneto by which the latter may be turned backward and thence restored to normal position relative to the drive shaftso as to cause the primary battery circuit to be interrupted by the circuit breaker and the high tension current directed by the distributer to the proper cylinder for starting the engine in the forward direction, and means for locking themagneto shaft and drive shaft in proper relationship when the engine is in operation.

5. In a. dual ignition system for an internal combustion engine, two sources of current comprising a battery and a magneto, the latter having associated therewith a drive shaft adapted to be operated by the engine, circuit interrupting and distributing mechanisms comprising movable parts adapted to be actuated by the drive shaft, a switch by which either the battery or the magneto may be connected to the interrupting and distributing mechanisms, and a coupling between the drive shaft and circuit interrupting and distributing mechanisms by which the latter may be operated independently of the drive shaft when the engine is at rest so as to interrupt the battery circuit and direct a spark to the pro er cylinder for starting the engine in the orward direction.

In testimony whereof, I hereunto aiX my signature in the presence of two witnesses. ALANSON P. BRUSH. Witnesses:

H. R. SULLIVAN, A. F, Kwis.

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