US2391525A - Coupling means - Google Patents

Description

'Dec. 25, 1945. w. J, SPENGLER' COUPLING MEANS Fi led June 15, 1942 INVENTOR ATTORNEY Patented Dec. 25, 1945 conrrnvcr MEANS Walter J. Spengler, Sidney, N. 3. assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application June 15, 1942, Serial No. 447,104

12 Claims.

This invention relates to couplings and more particularly to means for connecting two rotatin'g parts, such as parts of an internal combustion engine ignition system, so that automatic angular adjustments of said parts may be effected during rotation thereof, whereby the timing of the sparks produced by the ignition system in the engine cylinders may be automatically varied.

One of the objects of the present invention is to provide novel apparatus for mechanically coupling two rotating elements to each other while permitting of angular adjustment of one of said elements relative to the other.

Another object of the invention is to provide a novel automatic variable coupling for rotating parts which functions in accordance with the speed of rotation of said parts.

A further object is to provide novel means for automatically effecting adjustments in the timing of the ignition system of an internal combustion engine.

Still another object is to provide novel coupling means of the above character whereby two rotating parts may be automatically angularly adjusted in one direction relative to each other at one speed of rotation and in the other direction at a higher speed of rotation.

A still further object is to provide a novel, centrifugally responsive device for effecting an automatic variable connection between two rotatable parts.

Another object is to provide novel means adapted for use in the ignition system of an internal combustion engine for effecting spark advance at one engine speed and a retardation of the spark at a higher engine speed or vice versa.

Another object is to provide a novel ignition apparatus for an internal combustion engine whereby the sparks in the cylinders of the engine may be both advanced and retarded relative to the position of the pistons in said cylinders by a single, centrifugally actuated unit for coupling two rotating parts which are adapted for relative angular movement.

Another object is to provide coupling means of r the above character which also functions to some extent as a flexible coupling to avoid damage which might otherwise be occasioned by sudden shocks and quick changes of speed.

The above and further objects and novel features of the invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawing. It is to be expressly understood, however, that the drawin is for the purpose of 11- (Cl. G l-25) lustration only and is not intended asa definition of the limits of the invention; reference for this latter purpose being had primarilyto the appended claims.

In the drawing, wherein like reference characters refer to like parts throughout the several views,

Fig. 1 is a side elevation, partly in section and with parts broken away, showing amagnetoincorporating one form of the novel coupling unit comprehended by the present invention, the section of the coupling unit being taken on line l-l of Fig. 2;

Fig. 2 is an end elevation looking from left to right in Fig. 1, showing only the coupling unit apart from the magneto and with portions of the springs broken away; and,

Fig. 3 is a sectional view, with parts broken away, taken substantially 0n 1ine3-3 of Fig. 2.

Only oneembodiment of the invention is illustrated in the drawing, by way of example,'in the form of a coupling unit adapted for use in the ignition system of an internal combustion engine. As shown, the novel coupling unit of the invention is incorporated in amagneto for the purpose of automatically varying, the timing of the sparks in an ignition system relative to the positions of the pistons in the engine in which the sparks occur. The form of coupling unit shown in Figs. 1 to 3 is employed for connecting a rotating part of an engine (not shown) to the rotor shaft ill in a magneto Ll which may be of any suitable design well-known in the art and, hence, is only partially shown. In a manner also well understood by those skilled in the art, the rotor of the magneto is drivably connected with a circuit breaker cam (not shown) which operates in timed relation to the rotor and determines the time of the occurrenceofthe sparks in the engine cylinders. In a structure of this character wherein the timing cam is driven by the mag neto rotor, the coupling unit of the present invention is preferably located so that the rotor and the cam are affected alike by adjustments made by said unit, thereby insuring the opening of the primary circuit, of the magneto coil at the most advantageous moment for efiicient operation irrespective of the adjustments effected by the coupling unit. I

In the form shown, the novel coupling means of Fig. 1, whereby shaft Ill is flexibly connected to an engine driven part for automatic, angular adjustment relative thereto, comprises two end members [2 and I3 and an intermediate force'- transmitting member M. In a manner to be more fully described hereafter, these members are novelly mounted about shaft I and novel centrifugally responsive means I5 and I6 are provided for drivably connecting end members I2 and I3, respectively, to said intermediate member.

For the purposes of description, end member I2 may b considered as the driving member of the coupling since it is connected, although not necessarily, to the prime mover; which in the present instance is a rotating part of an engine on which magneto II is mounted. As shown, the hub portion I! of member I2 is provided, at one end thereof with external splines I8 that are adapted to engage an internally splined rotating part of the engine. A bearing sleeve I'9 is fitted into driving member I2 and is loosely mounted on' a smooth reduced portion of shaft III for free. angular movement relative thereto; A'n arm integral with or rigidly attached to driving member I2 extends in a radial direction from the axis of rotation of shaft It in" the plane of intermediate member I4; which is, in turn. loosely'm'ounted on' the hub 2I of endmember'l-df'or free, angular movement relative thereto. A bearing ring' 22 is preferably fitted in' member l4 to engage the bearing surface ofhub 2 I.

The centrifugally responsive means I5 provided for operatively connecting members I2 and I 4 comprises a lever which is preferably fabricated from two angular plates 23; 23 and a weight 24 interposed between said plates adjacent one end thereof, said parts being secured to ether by any suitable means, such as screws or bolts 25. The outside plates of lever 23;. 24 straddle arm 20 and member I4 and are pi votally secured to the outer end of said arm by meansof a pivot in 26'. An enlarged central portion of pin 26 (Fig. 1) acts as spacing'means: for arms: 23, 23 and is surrounded by a loose fitting: bearing sleeve 25a in arm20; Ina manner'toa-ppear hereafter. abearing pin 21' connects the'er'dsofplat'es' 23. 23 which straddle member I14 and slidably extends through av slot 28 irr saidi member; As shown; said slot extends generally ina radial direction; as viewed irrFig. 2. fromthe axis of'rotation: of the coupling unit. but the same'may be given a variety of contours depending upon the resultsdesired. Suitable resilient means. such as acoil spring 29. is connected: to lever 23; 24 at an and to driving member I2 at 31. said springv being under a' predetermined tension-when the above-describedparts are stationary for holding said parts in the positions illustrated. with bearing. pin 21 engaging the outer end of slot 28.

When the above-described parts are rotated in a counter-clockwise direction (Fig. 2) at or above a predetermined angular speed. the centrifugal force acting on the weighted end of lever 23. 24 causes thelatter to pivot counter-clockwise about pivot 26 a ainst'the efforts of spring 29 and the inertia of the parts and, hence, move bearing pin 21 tothe inner end of slot 28, This latter movement of pin- 21 necessitates angular movement of intermediate member I4 relative to driving member I 2 since pivot 26 is-nearer the. inner end of slot 28 tharrit is to the outer end. of saidslot. ='I.'hus, at apredet'ermined. angular speed. of member I2, the centritugall'y responsivemeans Iibecomes effective to cause a predetermined, angular movement of end member I2 relative to intermediate member I4. For example; member I'4-wil1 be moved in a counter-clockwise direction relative to driving: member I2 when the weighted end of lever 23. 24 is thrown outwardly by centrifugal force. Since member I4 is connected, in. amanner to appear hereafter, to the magneto rotor, the latter is moved ahead with respect to the engine driving member when weight 23, 24 moves outwardly and causes an advance in the timing of the sparks in the engine cylinders relative to the positions of the pistons in said cylinders.

It will be understood that by properly designing the, parts above described a variety of modes of operationmaybe obtained. If the relative angular positions of members I2 and I 4 or, in the illustrated structure, spark advance is plotted against the angular speed of member I2. the contour of the curve obtained may be greatly varied, for example, by changing the contour of slot 28, by changing: thev initial tension or design of spring 23, by changing the connecting points or other characteristics of the several parts so that the relationship between the increase in spring tension and theincrease ineffective centrifugal force, as weight I'5'moves outwardly, is changed or by pro- Viding: additional springs: that come into operation at diiferent positionsiot weight. I15. The spark advance or're'lative movement-obtainedlmay, for example;. be either gradual or abrupt or it may be obtained in aseriesrof abrupt or gradual steps.

End. member I.-3, which; may be conveniently referred to as-th'e-driven element of the coupling unit, isdrivably connected to rotor shaft: win the illustrated embodiment by means of splines within hub 2I that mesh with. externalv splines 32 on said shaft. Driven-member, in the formshown, is made up of two parts 33 and; 34- rigidly connected together by rivets 35 but these parts may be integral.

Centrifuga-llyresponsivemeans I-B-areprovided for drivably connecting, driven member I3 to: intermediate member I4, said means being similar to but having different operating characteristics than the connecting means between members I2 and I4 heretofore. described. Inthe form illustrated, means I6 comprises two flat arcuataplates or arms.36,. 3.6 which extend on opposite sides of radially extending arm 3401! member I3 and are pivotally securedl thereto by means including pivot pin. 3I-. In. order to insure freepivotal movement of the partsthus connected together, a bearing sleeve 38 (Fig. 3) fits-into an openingin arm 34 around an. enlarged central portion of pin 31, said enlarged portion serving as means for spacing the centrifuga1.weights.3'6, 36.

Arm 34 is preferably in the same radial plane as member I4 50 that connecting arms: 36, 36 also extend on opposite sides of said. member. The ends of said arms adjacent member I4 are connected together by a pin. 39' (Fig. 3) having an enlarged central portion which servesto space the arms. Surrounding the enlargedcentralportion of pin 39' and being free for angular movement thereonis a. cylinder or tube4ll which has a loose rolling or sliding fit, in an elongated slot M in. member I4. Pin 39 and. bearing sleeve 40, which thus have relatively frictionless engagement with the walls. of slot 4I may be considered as a part of the centrifugally responsive means I6 which includes the arms. 36, 36. The connection at pin. Z'I'between. arms 23, 23 and member I4 may be the same asv the connection at pin 39 to thereby provide a relatively frictionless connection.

Roller sleeve 40 is normally held. against the inner end of slot M, as shown in Fig. 2, by suitable resilient means, suchzas. a pair of coil. springs 42, 43. The upper ends of. said springs as viewed in the drawing, are secured by means of suitable adapters 44 to opposite ends of a pin 45 thatlextends through weights 36, 36 at a point between pivots 31 and 39, said pin being surrounded. by suitable spacer sleeves 46. The other end of spring 42 is secured to an angularly extending portion 41 of member l3 while the other end of spring 43 is secured to a bar 48 which freely extends through an elongated opening 49 in member l4 and is fixed to portion 4! of member l3.

In the embodiment described above, the parts of the coupling unit are held in assembled relation by a nut 50 which is threaded onto the end of rotor shaft II). In order to insure free, angular movement of members l2 and I4 relative to each other and to member l3, a force-transmitting washer or ring BI is interposed between bearing sleeves I9 and hub 2| of member IS. The other end of hub 2| either engages or effectively engages a shoulder on shaft l0. Since member l3 and shaft H! are, in effect, rigidly connected to one another, they may be considered as a single element.

' When the driving and driven parts l2 and I 3 are rotated in a counter-clockwise direction, as viewed in Fig. 2, at a predetermined speed, which is higher than that required to cause weight means 23, 24 to move outwardly, in the manner described above, springs 42, 43 will yield to the centrifugal forces acting on Weight means 16. The free end of said weight means will then move outwardly as the speed increases until roller 40 contacts the outer end of slot 4|. This movement of weight arms 36, 36 may be gradual or relatively abrupt, depending upon the design, connection and arrangement of the parts, the same as explained above in connection with centrifually responsive means IS. The effect of the above-mentioned movement. of Weight means It is to shorten the connection between members l3 and I4, thereby causing member l3 and shaft ill to move angularly in a clockwise direction, as viewed in Fig. 2, relative to member l4. Since during this functioning of weight means I 6 there is no relative angular movement of members I? and M, the driven element 13 and rotor shaft Iii are effectively retarded with respect to driven member 12, thereby causing a retardation of the sparks in the ignition system served by magneto to centrifugal forces.- The coupling units pro vided may be employed in a novel manner to automatically control the spark setting of. an ignition system in an infinite variety of ways for the purpose of obtaining eflicient and economical operation at substantially all speeds. Furthermore, the novel coupling means provided are simple in construction and operation and are also compact and reliable.

Although only one embodiment of the invention is illustrated and described in detail, it is to be expressly understood that the same is not limited thereto. As will now be apparent to those skilled in the art, various changes, such as in the design and arrangement of parts illustrated, may be made in the illustrated embodiment of the invention without departing from the spirit and scope thereof. For a definition of the limits of the invention, reference is had primarily to the appended claims.

What is claimed is: 1. Apparatus of the class described comprising a rotatable driving member, a rotatable driven member and means drivably connecting said members whereby the latter rotate together and are adapted for limited angular movement relative to each other, said connecting means comprising an intermediate element movable angularly relative to both of said members, centrifugally responsive means pivotally mounted on one of said members, other centrifugally responsive mean pivotally mounted on the other of said members, resilient means resisting movement of each of said centrifugally responsive means in response to centrifugal forces, and a pin and slot connection between each of said centrifugally responsive means and said intermediate element.

2. In apparatus of the class described, at least two rotatable members adapted for limited an- As the angular speed of the parts is reduced to or slightly below the predetermined speeds at which weight means I5 and i6 reach the out- Ward limits of their movements, in the manner above described, springs 29 and 42, 43, respectively, return said weight means to their normal or illustrated positions, thereby reversing the relative angular movements of the parts and, hence, the advance or retardation of the spark caused by the outward movements of said weight means. Thus, an engine may, for example, be operated at one spark setting for low speeds, at an advanced spark setting for intermediate speeds and at a retarded spark setting for high speeds, the spark setting being automatically effected by the apparatus of the present invention.

There is thus provided novel coupling means for rotatable parts, such as a magneto rotor and drive shaft therefor, whereby relative angular movements of said parts in either direction may be automatically effected during rotation there of, and whereby relative angular movements in opposite directions may be effected as the speed of rotation increases. Additionally, sald coupling means are so constructed as to efiect different relative angular movements of the connected parts at predetermined speeds thereof in response gular movement relative to each other, and means for drivably connecting said members including an intermediate connecting element angularly movable relative to both of said members, centrifugally responsive means connecting said element and one of said members and other centrifugally responsive means connecting said element and the other of said members, one of said centrifugally responsive means being adapted to efi'ect relative angular movement of said members in one direction in response to centrifugal forces and the other of said centrifugally responsive means being adapted to effect relative angular movement of said members in the other direction in response to centrifugal forces.

3. Apparatus of the class described comprising a rotatable driving member, a rotatable driven member, and means for drivably connecting said members whereby the latter may have limited relative angular movement, said connecting means comprising centrifugally responsive means for efiecting relative angular movement of said members in one direction in response to centrifugal forces and other centrifugally responsive means for effecting relative angular movement of said members in the other direction in response to centrifugal forces, the major portions of both of said centrifugally responsive means being mounted to rotate in approximately the same path.

4. In apparatus of the class described, a rotatable driving member, a driven member mounted for rotation with an angular movement relative to said driving member, each of said members having: a. radially extending arm portion, said am. portions being; positioned to. rotate in substantially the. same path, and? means; for operatively cormecting said; members includingoentrifugally' responsive means pivotally' mountied: onv eachof said arms, and; means including am intermediate member having a sliding connection with said: centrifugally responsive means operatively connecting said centrifugally responsive': means whereby the latter are; eifectiveto effect relative angular movement of said members in different directions; at difierent. speeds at rotation: thereof in response. to centriiugat forces actingv onsaid' responsive means.

5; Apparatus ot the class described comprising rotatable driving: means, rotatable driven means, and means for drivably connecting said driving and driven means whereby th latter may have limited angular movement relative to each other, said connecting means including: first cent-rindgally responsive means and: second centrifugally responsive means for effecting. relative: angular movement of said driving and: driven means, said first and second centriiugallyresponsive means being adapted to become operative: for effecting: relative angular movement ofsaid driv-- ing. and driven means at differentspeeds as the speed of. rotation of said: drivingv and driven means increases.

6-. Apparatus oi the class described comprising. driving. and driven rotatable members adapted. for angular movement relative to each other, an intermediate torque-transmitting, element movable. angularlyrelative to both of. said members, said element and said. members having radially extending portions adapted: to rotate in. substantially the same circumferential path, centrifugally responsive means operatively connecting the radially extending portions of said element and one of said: members and other centrifugally responsive means operatively connecting the radially extending portion of said element and the other of said members, and resilient means. for resisting movement of both of said centrifugally responsive. means, said resilient means and said centrifugally responsive means being so mounted and proportioned that the latter become operative at different speeds of rotation of said members to effect relative angular movements of said members in opposite directions in response to centrifugal. forces acting on said centriiuga-lly responsive means as the speed of rotation of saidmembersincreases.

7. Apparatus of the class describedcomprising arotatable driving member, a rotatable drivenmember fixed against axial movement relative tosaid driving member, means drivably connecting said members whereby the latter rotate together andare adapted for limited angular movement relative to each other, said connecting' means comprising centrifugally responsive means. for effecting relative angular movement 0tsaid members in different directions during different ranges of speeds of rotation as the speed of rotation increases, and. at least. two independent resilient means for controlling the movements of said centrifugally responsive means in response to centrifugal forces during different rangesof. speeds of said members.

8. In; apparatus of the. class described, at least two rotatable members fixed against axial movemenses relative tov each other and adapted for limited'. angular movement: relative to each other, means? for drivably connecting said members including centrifugally responsive means rotatable with said members for firsteffecting relative angular movement. of said members. irr one direction and then: effecting; relative. angular movement of said: members in the other direction as the speed of. rotatiom of said members increases, and atleast two: independent resilient means for controlling the movement of. said centritugally responsive. means in response. to. centrifugal forces; during different ranges of: speeds of said members;

9. Apparatus: of theclass describedl comprising at. least two: rotatable members adapted for limited angular movement relativev to each other, and means:- for drivablyt connecting; said! members, including anintermediate element movable angularly relative to both of said. members, centrifugally responsive means mounted on. one of said members, other .centrifugally responsive means mounted: on the other 05 saidmembers, resilient. means resistin movement of each 05 said. centriiugally responsive means in response to centrifugali forces and a sliding. connection between eaclr of saidf centrifiugally' responsive means and said; intermediate element.

i 10;. Apparatus of the class described. comprising two rotatable members. adapted for angular movement relative to: each: other, and. means drivably connecting said. members, including an intermediate element loosely mounted on one of said members, centrifugallyresponsive means connecting one of said members to said element, other centrifugally responsive means: operable independently of said first-mentioned centrifugally responsive means connecting said. element to the other of said: members and resilient means resisting movementof each of the=centrifugal1y responsive means relative: to said element and members.

11. Apparatus of theclass described comprising two rotatable: members adapted. for angular movement relative to each other, and. means for drivably connecting saidmembers, comprising an intermediate element movable angula-rly relative to both of said members, centrifugally responsive means connecting one of. said members and said element and adaptedv toeffect a, relative angular movement thereof, other centrifugally responsive means operable. independently of said firstmentioned centrifugally responsive means connecting saidelement and the other of. saidmembers andadapted to effect relative angular movement thereof and resilien-tmeansresisting movement of eaclr of said centri-fugally responsive means-in responseto centrifugalforces.

12-.. Apparatus of. the class described comprising. two rotatable; members adapted for angular movement. relative to each. other, and means drivably connecting said members and. adapted to eilect angular-movement of oneof. saidmembers relative totheother, saidconnecting means comprising anintermediate element'movable angularly relative. to both of said. members. and pivotally mounted centrifugally responsive means and. a pin and slot connection for operatively connecting. each of said membersto said element.

WALTER J.. SPENGLER.

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