US1287659A - Magneto-impulser. - Google Patents

Description

Patented Dec 17 1918 2 SHEET$SHEET 1 I mum R K EVANS MAGNETO IMPULSER.

APPLICATION man JULY 29. me.

R. KfEVANS.

MAGNET'O IMPULSER.

APPLICATION FILED JULY 29.1918.

Pzitented Dec. 17, 1918.

2 SHEETSSHEET 2.

UNITED STATES PATENT ornrcn.

302mm) x. EVANS, or CHEBOYGAN, momeim, essronon are some r. o. s'mar'rox,

' or ELKHART, morons.

MAGNETO-IMPULSER.

Specification of Letters Patent. 1 Patented Dec. 17, 1918.

Application filed July 29, 1918. Serial No, 247,326.

of Gheboygan, in the county of Cheboygan and State of Michigan, have invented certain new and useful Improvements 1n Mag- .neto-Impnlsers; and I do hereby declare that the following is a full, clear, and ex- .act description thereof, reference being had late the accompanying drawings, and to the letters of reierencemarked thereon, which form a part of thisspecification.

My invention relates to mechanism for driving a magneto usedin connection with internal combustion engines for producing the current to effect the ignition of the charges in the engine, and relates more particularly to that class of mechanisms which operate to produce the maximum current flow or spark introduced into the cylinder or cylinders of the engine by means of a momentary acceleration of one of the moving parts of the magneto.

In starting a motor, the normal average sparking moment of the magneto connected therewith occurs when the crank of the piston compressing the gases in the cylinder is from zero to ten degrees ahead of the dead center on the upward stroke.

One of the objects of my invention, therefore, is to retard or arrest the normal rotation of the armature in relation to the crank shaft, while the crank shaft continues to advance. and then to release the armature at that minute element of time which intervcncs between the extreme moment of compression and the moment of explosion, so as to produce not only the explosion or impulse at the correct time but also to produce the maximum current fiow or spark at that particular moment.

Another object of my invention is not only to produce the explosion or impulse at the correct moment but predetermines the firing moment of the motor at all speeds under 180 R. l M.- regardless of any spark control which may have been provided for the purpose of advancing or retarding the tiring moment of the motor.

Another object is to eliminate all danger of backfire when the magneto is properly timcd with the motor so that the operator need give no attention to the position of the spark control when cranking the motor.

Another object is to provide a device which may be so adjusted that the motor and magneto may be properly timed for starting and for very low speed conditions and, which immediately upon the motor attaining a speed sufiicient for the impulser to become inoperative, the firing moment will advance to any desired degree of angularity thereby providing a much more desirable running condition of the motor without dependence on manual operation.

In other words, one of the principal objects of my invention isto so regulate the mechanism with respect to the magneto as to produce the maximum spark at low speed at any desired moment of ignition.

Another object of my-invention is to automatically retard the spark when it is in action by causing the armature to be at rest during the period that the driving shaft advances a predetermined annular distance, and then releasing the armature and automatically causing it to advance to its. nor-.-

mal position in relation to the motor crank shaft under an accelerated speed; the moment of acceleration being fixed in relation to the desired and predetermined moment of explosion in the cylinder on the compression and explosion stroke. Thus, no matter when the firing moment of the motor may occur at all speeds under 180 R. P. M. re

gardless of any spark which may have been provided for the purpose of advancing or retarding the firing moment of the motor, it is the object of my device to time the motor to fire at a position coinciding with the correct impulsing moment of the magneto.

It is desirable, in magnetos for multi 1e cylinder motors, that the impulser act with each explosion stroke. It is one of the principal objects of my invention, therefore, to provide a mechanism which in operation will result in two impulses. for each revolution of the magneto shaft, each one corresponding to the two explosion strokes of a four cylinder motor. I

It is another object of my invention to produce a simple, durable, relatively cheap mechanical construction in a spark regulator and impulser. for'the purposes above stated, in which all the working and fixed parts are contained within a casing or jacket, and in which the parts function automatically, so that the operator has only to apply, externally, the necessary power to rotate the magneto shaft,a mechanism which shall be so constructed as to produce the maximum of desired results with the minimum of vibration, jarring andwearing of the various parts.

In the drawings:

Figure 1 is a perspective view of the easing of a magneto to .which my improved (perspective view of a yoke by the rotatable driving Fig. 5 is a vertical, sectional view of the spark regulator and im ulser, taken upon the plane indicated by t e dotted line 55 of Fig. 2.

Fig. 6 is a view corresponding to that of Fig. 2 but taken upon the plane indicated by the sectional line 6-6 of Fi 5, and

' looking in the direction indicated y thenrows. v Fig. 7 is a sectional view, taken on the plane indicated by the dotted line 7 7 of Fig. 5, looking in the direction indicated by the arrows.

Fig. 8 is a vertical, sectional view through i the tapered portion of the armature shaft 'and the bearing hub of the. driven member, showing more clearly the integral lug and. its relation to a yielding member or spring .and showing also in dotted lines, the relative location on the opposite side of said driven member of the two awl members.

Beferringto that embo ime nt of my invention shown in the accompanying drawings, the casing A of the magneto contains the usual horse-shoe magnets, armature, and the like, not shown, and a journal bearin u for the armature or magneto shaft B. he shaft B is preferably provided with a tapered portion 5 and a threaded end portion 7). (l is a. drive shattconnccted by suitable couplings D with the coupling D, the latter being secured to or integral with a rotatable driving member 10.

The stationary support 1, suitably secured tothe'magneto frame A, is provided with an outwardly projecting, circular flange or wall 2. Upon the inner faceof the support 1 is a cam member 3, suitably. secured by screws t or otherwise in a predetermined position to said support. A rotatable driven member 5, of disk form, provided with an apertured bearin hub 6, is secured to the armature shaft B y the key 7. As shown in the drawing, the aperture of the driven member 5 and a portion of the a erture of its bearing hub 6, are taperec to fit over the correspondingly tapered portion I) of the shaft B. A spanner lock nut 8, provided with a hub 9, is interiorly screw threaded for engagement with the threaded 'end I) of the shaft, the diameter of thenut greater than the diameter of the end e hub bearing 6 so as to have overlapping engagement with the driving member 10. J The nut 8 being thus locked by the screw threads onto the armature shaft and the driven member 5 and its hub 6 being keyed to said shaft, said three partsrotate together and at the same time the nut 8 bearing against the face of the driving member 10 holds the latter in place. In practice, I recommend a small clearance, say .005 of an inch between the end of the hub 6 and the adjacent'surface of the nut B.

b fit The external diameter of the hub 9 issuch as to aiford bearing engagement thereof within the untapere the hub 6 of the driven member 5.

The driving member 10 is provided with an annular, upwardly extending wall 11', which at its up r margin is exteriorly recessed at 12, so t at said wall 11 at its upper end will fit within and register with the wall 2 of the sup ort 1, as clearly shown in Figs. 1 and 5. aid driven member 10 is provided with an interior bearing 'hub 13, which is centrally apertured to fit about and to have rotative, bearin engagement with the hub 6' Between the caring hub 13 and the circular wall 11, is an annular recess, spanned at one portion only by a radial rib 14. This recess provides space for the yielding member 15, which in the present instance =takes the form of a spiral spring. ()ne end of the spring 15 has permanent bearing against one side or face of the radial rib 141. The length of the spring 15 is such that its other end would rest against the o posite side of said radial rib 14 and won d so rest, except for the inter-position ofa movable lug 17 and a yielding stop or cushion 16 which, in the present instance, takes the form of leather packing (see Fig. 7). Said big 17 is integral with or fixedly connected to the driven member 5, and extends from that face thereoffrom which the hearing hub 6 extends.

.On. that side of .the driven member or disk 5, opposite that carrying the lug 17, are two studs or pins 18, 18. Each of said pins afl'ords a pivotal bearing support for a locking pawl 19, suitably apertured to fit over said pin. .Each pawl 19, at its outer end, is providedwith a lug 20, adapted. to engage the cam 3. The cam 3 is provided on its peripheral margin with a cut away apertured portion of lug 14.

portion 21 which terminates in a camshoulder 22. The lug 20 of the pawl is adapted, at certain periods in the movement hereinafter described, to fall into the outway portion 21 and to have locking engage ment with the cam shoulder 22, as clearly indicated in Figs. 2 and 6. i

23 is an apertured yoke, loosely and rotatively mounted upon a bearing shoulder 24 of the armature shaft bearing. Said yoke isvprovided With radially, outwardly and diametrically oppositely extending arms 25, the outer ends of said arms are set in and have engagement with suitable recesses 26 in the reduced end 12 of the Wall 11 of the driving h'ie'mber 10.

The operation of my invention is as fol lows: the drive shaft C is rotated in the usual manner and, through the couplings D, D", the driving member 10 is similarly rotated. Bythe engagement of the lug 17 on the driven member 5 between the yielding or spring member 15 with the lug 14 and the interposed. cushion 16 (see Fig. 7), the driving and driven members will be simultaneously rotated, until the outer end 2B of one of the pawls 19, swinging upon its stud 18, drops into the cut-away space 21 of the fixed cam 3 and comes into contact with the eamsshoulder 22. When the lug 20 is thus engaging the non-rotatable cam shoulder 22, and the driven member 5 is thus arrested, the rotary forward movement of the driving member 10 continues, though momentarily retarded in its speed by the resisting action of the spring 15 when compressed by the lug 17 against the radial The continued rotation of thedrivmg member 10, however, presently brings one of the arms 25 of the yoke 23 into a position when the pawl 19 is lifted by said arm from the cam shoulder 22. Thereupon the spring 15 Will immediately expand into its normal position with the efiect of causin the momentarily retarded but now released driven member 5 to again move forward in itspath of rotation, and with an accelerated motion, as compared with the speed of retation of the driving member 10; and thus, so to speak, catch up with the driving member 10.

This momentary retarding of the forward movement of the driven member 5 continues while the driving member 10 travels over an area of apparently 32 degrees. Thus the current flow or spark is produced at the proper and predetermined moment of time.

m'milar action takes place with respect to the secondpawl 19, as the revolution of the driving member IOrontinues. it will be understood that While the driving member 10 is makinn one complete revolution. the retardinggand then the accelerated forward movement of the'driven member and the magneto shaft will take place twice. There are tli'us produced two impulses for e single revolution of the shaft, COHQSQOHilL-fl; to the two explosion strokes of a four cyhnder motor.

I have stated that one nit-the objects of my To invention is to provide such an adjustment that the motor and magneto ma be properly timed for starting and for very low speed conditions and this may be accomplished by adjusting the position of? the '75 driven membewith respect to the armature shaft, and having in mind the accurate relation of the locking key-Way of said shaft to the fixed cam. in practice, when an cillating circuit breaker is used with my invention, this adjustment may be effected in the following manner:

The key-Way in the armature shaft will be milled in accurate relation to the lined cam. The keywvuy in the driven member 5 is then cut in such position that the hi9: 2% of the pawl 19 will engage the cam shoulder at the point at which the armature circuit breaker cam is 20 degrees before the position at which the circuit breaker will open at full advance, or on the peak of. the wave. it must be borne in mind that the .-:tan(lard range of spark control adapted for couuuerc-ial use, and required by the Government, is 32 degrees, and this range starts the full advance or high wave position in the dirertion of rotation. it, for example, the circuit breaker is set at er ll retard, it will be necessary to provide? that the impulse reach this point. in its forward travel. Therefore, by adding 32 degrees to the 20- degrees already allowed, and by adding;- (3 degrees additional as a margin of safety to insure the circuit breaker always opening, a range oi approximately 58 degrees is oh rained over which the impulser must operate. it ishighly desirable to a-fin the 21'? de- Qrees referred to ahead of the ful advance position, in order to insure the armature against saturation when its rotation tarded. to allow for the armature havnr ficient speed in its impulse heifore cuit breaker opens and to guard against any inaccuracies in time. i then" place ti 23 in such a position in the driving: member i i l0, that its "forward movement will c ul'i'nur through 68 degrees of rotation before said yoke comes in contact with and the lug 20 from the cam shoulder Thug 1 will be seen that the amount of impu the lugs and the yoke are operatln I substantially correspond with the pos Ii 6 (a tne ew tion at which ircuit breaker will open when the impulser is not operating; the former being: about (3 degrees later, on a perfect instru ment. The, momentof impulse may then be marked, one mark being: placed on a stationary shell 1 and another mark on the driving member 10. The I'iy Wheel of the motor is, then brought to a position at which it is I30 open. a

desired to fire the motor when cranked, and the marks thus made should then coincide and the driving coupling keyed to the drivin shaft.

pon cranking it will be found that the rotation of the armature shaft will be inter- -rupted at a point 58 degrees before the mo- It Wlll also be found that the motor cannot fire in advance, as it has already reached its firing position before the impulser is tripped. This operation just described refers to the use of my impulser with an oscillating circuit breaker.

In its use with a fixed circuit breaker, the latter is made to break at the peak of the wave and to secure anv desired position, it is only necessary to change the location of the key-way in the armature shaft in its relation to the predetermined position to fixed cam. Having already explained that 58 degrees is the correct wind or travel of assuming that the operator desires to run the motor to fire 12 degrees, for example, in advance of its firing moment in starting (subtracting the 12 degrees from the 58, leaving 46 degrees) he will key the armature shaft to the driven member 5 in such position that the move ment of the armature will be 46 degrees before the circuit breaker would normally the impulser, and

By timing the motor to fire at a position coinciding with the impulsin the magneto, it will be found t iat when the motor reaches a speed at which-the impulser becomes inoperative, the motor will automatically advance the desired 12 degrees. By thus adjusting the locking position of the cam shoulder 22 with relation to the center and to the armature, the interruption of the forward movement of the armature is caused io take. place at the desired, predetermined time. Thus the cam is initially adjusted or set in a pre determined position on the support.

it will be noted that the form in which my invention is embodied, as above described, is exceedingly simple, includes the fewest number of parts, is positive and accurate in its operation, is substantially dust and fool proof, and that once adjusted it is not liable to get out of order. Its efiiciency and durability are therefore limited only to the length of normal wear and tear in use.

Slight modifications may, of course, be

driving moment of j the firing moment of member .in juxtapositiom a rotatable magneto shaft, a stationary cam member in pixtapositlon to saidshaft, a driving member, a driven member on said shaft, means operatively connecting the driving and driven members, said means including means for accelerating the movement of the driven member, driven member adapted for ,engagement with the stationary cam member to retard the rotary movement of the driven member during a portion of its movement, and means located between member and in operative enga ement with the driving member for releaslng the cam engaging means.

In a device of the character described, a rotatable magneto shaft, a stationary cam member in juxtaposition to said shaft, a member, a driven member on said shaft, means operatively connecting the driving and driven members, 1 said means including means for accelerating the movement of the driven member, means on the driven member adapted for engagement with the stationary cam member to retard the rotary movement ofth'e driven member during a portion of its movement, and rotatable means in operative engagement with the driving member whereby the cam engaging means on the driven memberwill the cam and. the driven means on the be released from engagement with the cam member.

a rotatable magneto shaft, a stationary cam to said shaft, a driving member, a driven member upon and rotatable with said shaft, means operatively connecting the driving and driven members, said means including means for automatically accelerating driven member, means on her adapted for automatic engagen'ient; the cam member to retard the rotary move ment of the driven member during a portion of its movement, and means located between the cam and the driven member adapted to release said cam engaging means.

the movement of the the driven memwith 4. In a device of the character described,

a support having shaft bearing, a rotatable magneto shaft, a hub on said bearing, a stationary cam on the support, a driving member, a rotatable driven member-within the driving membe gand secured to said shaft, means operatively connecting the driving extending operatively operatively connecting arm in operative engagement with the 50 with the cam,

and driven members, means on the driven member adapted for engagement with the cam, and a yoke member rotatably mounted on said hub and provided with a radially arm in operative engagement with the driving member and adapted to contact with the cam engaging means.

5. In a device of the character described, a support having shaft bearing, a rotatable 10 magneto shaft, a hub on said bearing, a stationary cam ad]usted on the support in a predetermined position, a driving member, a rotatable driven member within the driving member and secured to said shaft, means connecting the driving and driven members, means on the driven member adapted for engagement with the cam, and a yoke member rotatably mounted on said hub and provided with a radially ex- 20 tending arm in operative engagement with the driving member and adapted to contact with the cam engaging means.

6. In a device of the character described, a support having shaft bearing, a rotatable 25 magneto shaft, a hub on said bearing, a stationary cam adjusted in a predeterminedrelation on the support, a driving member, a rotatable driven member within the driving member and secured to said shaft, means the driving and driven members, means .on the driven member adapted for engagement with the cam, .a yoke memb rotatably mounted on said hub and provided with a radially extenging 1'1V- ing member and adapted to contact with the 'cam engaging means, and means for producing relative movement between the driving and driven members and an accelerated 40 movement of the shaft when the cam engaging means is released.

7. In a device ofthe character described, a support having shaft bearing, a rotatable magneto shaft, a hub on said bearing, a stationary cam adjusted in a predetermined relation on the support, a driving member, a rotatable driven member within the driving member and secured to said shaft, means on the driven member adapted for engagement a yoke member rotatably mounted on said hub and provided with a radially extending arm in operative engagement with thedriving member and adapted to contact with the cam engaging means,

and means for producing relative movement between the driving and driven members an an accelerated movement of the shaft when the cam engaging means is released, said means embracing a radial rib in the driving member, a lag on the driven member projecting within the driving member and a yielding device interposed between the rib and the lug.

8. In a device of the character described, a

support having a shaft bearing, a hub on said bearing, a rotatable magneto shaft in said bearing, a stationary cam on said support, a rotatable driving member, a driven member on and rotatable with the shaft, a yoke member rotatably mounted on the bearing hub and positioned between the driven member and the cam. two radially projecting arms on the yoke the ends of which are in operative engagement with the driving member, two cam engaging members pivotally mounted. diametrically on the driven member adapted each in its turn to engage the cam, and means operatively connecting the driving and driven members adapted for producing relative moven'ient between them.

9. In a device of" the character described, a support having a shaft bearing, a hub on said bearing, a rotatable magneto shaft in said bearing, a stationary cam on said support, a rotatable driving member, a driven member on and rotatable with shaft a yoke member rotatably mounted on the bearing hub and positioned between the driven member and the cam, two radially projecting arms on the yoke the ends of which are in operative engagement with the driving member, two cam engaging members pivotally mounted diametrically on the driven member adapted each in its turn to engage the cam, and means operativeiy connecting the driving and driven members adapted for producing relative movement between them, twice in each revolution.

10. In a device of the character described, a support having a shaft bearing, a hub on said bearing, a rotatable magneto shaft in said bearing, a stationary cam on said support, a rotatable driving member. a driven member on and rotatable with the shaft, a yoke member rotatably mounted on the bearing hub and positioned between the driven member and the cam, two radially projecting arms on the yoke the ends of which are in operative engagement with the driving member, two cam'engaging members pivotally mounted diametrically on the driven member adapted each in its turn to engage thecam, and means operatively connecting the driving and driven members adapted for producing relative movement between them, twice in each revolution and time during a travel of approximately 32 degrees,

11. In a device of the character described, a support, a rotatable magneto shaft projecting therefrom, a stationary cam on said support, a driving shaft coupling in alinement with the magneto shaft, :1 driving member interposed between the shaft and said coupling, a driven member on the shaft, means for operatively connecting the drii ing and driven members, means on the driven member adapted UJ engage the cam, re easing means located between the driven ing a rotatable shaft, a cam member, a support on the magneto for said cam member, a

' driving member on the shaft, a driven memher mounted on the shaft, means associated with said driven member to engage the cam member and retard the movement of the driven'member, means operatively connecting the driving and driven members including means for accelerating the movement of the driven member upon its release, means located between the cam and the driven memthe release of the cam engaging means shall occur coincidentally with the high wave moment of the magneto.

In testimony, that I, claim the foregoing as my invention I. afiix my si ature in the presence of two witnesses, this 13th day of July A D. 1918.

RONALD K. EVANS.

Witnesses:

WILLIAM L. MEALS, KARL W. Dorm.

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