US2738968A - Snap-action governor - Google Patents

Description

March 20, 1956 G. FLElscHEl. 2,738,968

SNAP-ACTION GOVERNOR Filed May 20, 1950 3 Sheets-Sheet l T 1:1.1A-

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EN? T13-4- INI/EN TOR. 671,5' 7M /2 5/5 c//EL 50 BY V fauw March 20, 1956 G. FLElscHEl. 2,738,958

SNAP-ACTION GOVERNOR Filed May 20, 1950 I5 Sheets-Sheet 2 INVENTOR. QQ S70/v /f/scf/Ez,

March 20, 1956 G. FLEISCHEL SNAP-ACTION GOVERNOR Filed May 20, 1950 3 Sheets-Sheet 3 BY cmm United States Patent() p 2,738,968V p 4staar-ACTION GovERNoR Gaston Fleischel, Paris, France; dedicated (by mesnieassignments) to the free use anti'benetit of the public A `Application May 20, 195o, sedative-163,240 4 Claims. (c1. 264-17) trifugal force, as the gradual speed increase operates againsttincreased tensioning of theresisting spring or jump'between two -extrem'e positions as the speed exceeds or =drops below- Vpredetermined values,'- the former device` being clas'sitied as a static governorand'the latter VVas astatic governor. This'rnotion is Vfinallyl transmitted to a mechanismwhich adjusts or modifies the operating com ance with the governor position.A Y v A i In a large iieldo applications, spring loaded -govefors ditions ofthe apparatus sought tobe controlled in accordcauses shifting of a control member lengthwise of the rotating shift, or in any other directions through lever or other J operating connections.

Further and more specic objects of the present invention will in part be obvious and in part will be specifically .pointed out in the following description of several illustrative embodiments of the invention.

in the drawings annexed hereto, and hereof,

Figure l is a vertical section through one form of device constructed according to and embodying the present invention, illustrating a single governor with two spaced equilibriums and characterized by the absence of linkage;

Figure 1A is a graphic illustration of the theoretical operation of the devices in accordance with the present invention;

Figure 2 is a vertical section through another embodiment of my invention as applied to a double governor with three equilibrium positions and characterized by the absence o`f linkage;

Figure 3 is a vertical section through still another cmbodiment of the present invention as applied to `a double governor with three equilibrium positions and characterized bythe absence of linkage;

Figure 4 is alvertical section through'a further embodiforming a .part

i ment lof ythe present invention as applied to a single have to 'be eifective only within aV :fairly narrow frange aroundone or several definite speeds. It istlie aim-'of the 'inventionv to v`provide a'fgvernor havi'n'g'a control member which determines-the working( conditions-Which shifts suddenly fromv yone operative position'to *another operative position. rlhissuddenppositive'shift'is the snapaction referred-to "herein, In this invention, this" snap'- action is achievedby giving to -the effective driving `force of the governor control member, as Vthe motion begins, an excess of force over the opposing force of the spring, taking into consideration the variation of the strength ofsaid spring 'between two or more operative positions.

The main object of the present invention is the provision of a simple spring-loaded governor of the astatic type wherein the rate of increase in centrifugal force by movement of the rotating masses away from the axis of `rotation a ainst kthe anta onistic s rin is in excess of the increase in spring tension, above that of the preloading of said spring, in such a manner that any motion startedby the centrifugal force overcoming the strength of the preloaded spring, is accelerated all along the motion, whereby the snap-action effect is achieved.

Another main object of the present invention is the provision of a spring loaded governor providing a plurality of snap-actions resulting in shifting of a control member in stepped fashiorlk positively and suddenly `from starting position to one or more successive spaced posi- "tions of equilibrium.

Other and associated main objects of the present invention are 'the provision of a spring loaded governor lproviding a snap-action etect wherein the increased spring torce is suddenly overcome wholly by the increase `in centrifugal force developed by the rotating masses; or alternately wherein the increased spring force is suddenly overcome partly by the increase in centrifugal vforces developed by the rotating masses and partly by levers or linkage systems disposed within the governor or interposed between the governor and the opposed spring.

vAnother object of the invention is the provision of a spring-opposed snap-action governor wherein thcmovemeut of masses outwardly from the axis of rotation governor `with three equilibrium positions 'andcharacterized by the absence of linkage;

' Figure :5 is a vertical section through a still further embodiment ofthe present invention as applied to 'a governor providing snap action resulting partly by mass movement and partly by internally arranged variable linkage;

Figures 6 and? are views partly in section and partly in side elevation of modifications of the present invention as applied to' governors providing snap action partly by mass movement and partly by externally arranged levers;

Figure 8 is a similar View of a governor providing three equilibrium positions partly by mass movement and partly by externally arranged levers;

Figure 9 is a similar view of a governor providing two equilibrium positions partly by mass movement and partly by externally arranged levers, but operating at a variable angular velocity, in a predetermined range, in accordance with the requirements of the device connected therewith; and

Figures 10, l1 and l2 are similar views of the same type ofgovernor providing a three position snap action, partly by mass movement and partly by externally arranged levers, operating at two different angular velocities, each variable in a given range, according to requirements of the device associated therewith.

In connection with the present invention, it will be demonstrated how a governor can actuate a signal such as an electric signal having two operative equilibrium positions, as signal on, signal oli.

Referring to Figure l, wherein means wholly within the governor are provided to achieve the desired snapaction, a jump between two equilibrium positions, my device is indicated generally by reference numeral 10 n including a rotatable shaft 12 on which is axially fixed portion 3l) extending from a circle having a radius equal to the distance between the center-line of shaft 12 and point 31. The normal spacing between shell 14v and plate24, at 23,' is that of 'the diameter of trapped vballs 22, Z2. The head 32 of sleeve 26 bears against-an arm 34 fixed to a sliding shaft 36, behind which is-disposed [a helical compression spring 3S, positioned between sh'aft 36 and a suitable stop 4t). The normal compression for the preloading of spring 38 urges shaft 36, arn134`and sleeve 26 into the position of Figure 1 with the balls 22 pressed against shell 10.

The axial shifting of collar 26 yand attached plate 24 is caused by the force lof rotating balls or Weights 22 pushing against the inclined surface of the cone which engages the balls 22 when the resolved axial component of said force against said surface is stronger than the force of the biased or preloaded spring 38. This'occurs at a given angular velocity, called hereafter the Vgovernor specific velocity; belowV said velocity due to spring 38 action, all parts remain inthe position shown in Figure l. When the action of balls on the engaged surface ofthe cone 30 overcomes the force'of spring 3S, the cone 3i) and hub 26 begin a sliding motion toV the'left, as in Figure l, 'thereby compressing the spring 33 and increasing the force of the spring 38 urging the cone 31B and the hub 26 to the right. Y Y 7 To overcome this increase of resistance of spring 3S against the axialmovement of shaft 36 and sleeve 26, vvithoutanyV change in angular velocity, it is necessary to build up lsufficient force as to result in an axialinovetion. As the'motion starts, the increase-of spring tension is shown by line CD while increasing centrifugal force ment-of shaft r36 despite the increased force of spring' d8. f

Due to the cone shape of plate 24, theV axial push ,rey-y mains proportional to the centrifugal force developed,

which increases accordingly. This result is achieved as a resultl of the'radial Vmovement, of balls 22, '22. The

centrifugal force is proportional to the radius of thecenter of gravityofthe balls, vthe mass of said balls', Yand thesquare of the angular velocit;l thereof. Thus, since the weight or mass of the balls is a constantfactor, and it .is undesirable to chanvgethe angular velocity sincev to do so is inconsistent with the desired snap action, thevonly way`it is possible to secure anV increase in centrifugal force is by an increase in the radialpositioning of the center of gravity of the balls. Such increase is obtained by form-` ing cone portion 30 of such angularity that the ball movement between the governor in closed position, as in Figure 1, and in openv position, where balls bear against the cylindrical ange 16, is large enough to insure the needed increase. That is, the increase in the axial Vcomponent of the force of the balls 22 as they move radially outwardly against .the surface of thec one 30 is greater than the increase in the force of the compression spring 38 as the cone 30 moves axially toward the spring 38, thus resulting in the balls 22 and cone 30 jumping from one extreme position to another.

With the structure of Figure l, the governor operates as follows: y

As long as angular velocity remains below the specific velocity, the governor remains closed, the preloaded spring being stronger than the axial push of the centrifugal force. When the specitic velocity is reached, the motion starts, the force exerted by balls 22 developing to a point beyond that of the preload of the spring. This starting motion increases both the spring resistance and the force exerted by balls 22; but as the latter increase is faster than the former, the starting motion is accelerated, and the gov-v ernor jumps to its open positionk despite the increased spring resistance. And as the balls reach the cylinder flange 16 and are held there by the continuing velocity, the governor stays open.

Figure 1A is a diagram showing the magnitude of all acting forces. Forces are plotted vertically against governor axial travel indicated as a between two extreme locations, al and a2. Line 1131 is the preloaded force of spring 3S; BC is the force needed to overcome frictions; thus alC is the push developed by the centrifugal force at the specific velocity at the starting point of mo#4 follows line CH. The shaded area shows the excess of centrifugal force over the spring force.

There is snap action'too in the return' motion from open to closed position of the governor. Assuming that the governor is open, the velocity being above the specific value, and that the velocity decreases, the magnitude of the governor axial push is to be read on the vertical line Yn2,y andV goes down from the upper part of said line. The compressed spring resistance corresponds now to a2B2 with a friction loss BZG. The return motion begins when the axial push value falls below point G and is accelerated .because the slope of axial push decrease GK is more inclined than that of spring decrease GE. Thus the acting force which in that way is delivered by the .spring takes advantage over the resisting one, now the governor axial push, and snap action is obtained this way too.

Hereaften line B1B2 will be referred to as spring characteristic, and lines CH or GK as governor characteristic,

it being understood that there is a governor characteristic for each direction o f motion if friction `is taken in consideration. g

It is essential,therefore, that in a governor with built in snapl action, the slope of .the governor characteristic depending on balls or weights having radial travel must be greater than theV slope of the spring characteristic.

. v yIn Figure 2, is illustrated atwo-stage snap acting device V,contained wholly .within a vdouble governor; this device lis ldesigned in view to insure three operative positions, the governor jumping from the first to the second equilibrium positionv at specic velocity and from the second to .the

third equilibrium posi/tion at another specific velocity.

,Sjmilarparts are referred to by similar reference numerals (although .the effective members as 34,42, 44 and the like-havebeen omitted, as will' be readily understood).

In this device,- a smallshell 14a'- is axiallyand lslidably mounted ongvan 4extension v12a of shaft 12 for rotationl with cone 30 (as in Figure l). However, balls 22a, 22a, trapped within lshell 14aV are smaller and lighter than the v masses 2,2, l,22,in shell 14.` In this case, masses 22, V22. will move outwardly first, at the first specic velocity of shaft 12, shifting plate Z8 and vshell 14d attached thereto by collar 29 lengthwise of shafty12.- This'r'st step snap action will be followed by a second snap action, when the second velocity of shaft 12 is reached weights 22a, 22a thereupon shifting plate 23a still further vaxially of the shafts and a second time creating a state of unbalance as to overcome the increased tension of spring 38. .It is to be noted that masses 22, 22a originally are equidistant from the axis of rotation; but that at speed, theyameter; thus to insure two different specific velocities,l balls 22 must. be'spaced further from shaft i2 axis than balls 22h, when both elementary governors are close l. Two shells `14 and Mb are provided, plate of shell 14 being'secured to shell rdb for'nicvement therewith axially of shaft 12 and stub iZb by collar'ZZ, masses 22b,"22b trapped in shell lid-b are closer to the axis of rotation than are masses 22, 22 in shell iii, "l'hus, masses 22, 22 will, in response to speed increase the shaft 12, shift out first, creating a snap action movement of stub shaft Zb through collar 29h, shell Mb, plate 2gb and collar 26b.

l Herer as the starting radii of balls 22 and 22hA are :iframes different, the aperture angles of cones and 30b must also be different.

Figure 4 is an illustration of a single governor giving three operative or equilibrium positions with built-in snap action.

In Figure 4, a two stage three position operating device is illustrated, also wholly contained within the governor assembly, wherein shaft 40 has a shell 42 secured thereto for rotation therewith, shell 40 having an annular flange 44. Within the recess of shell 42, a collar 46 is fastened to shaft 40 having Aradially extending slotted arms 48, 49, within which are trapped weighted balls or masses S0, 50. A plate 52 is provided, axially slidable along shaft 40 and capped by a collar 54; Plate 52 isV flat adjacent the shaft, as at 56, but there are two successive conical surfaces, one 58 of Vwider angle aperture than the other 60; as a result the axial component of the centrifugal force which is transmitted to the plate 52 by the balls is relatively greater when the balls ride along surface 58 than when they ride along surface 6i).

Thus, when the yiirst specific velocity is reached, the balls jump radially until they meet the second conical surface where they are stopped by the sudden decrease in the transmitted axial component of the centrifugal force which does notexceed the force of the compressed spring 38 due to the change of the profile. This is the second operative or equilibrium position of governor. But when the other specic velocity is reached, the increase of centrifugal force enables the balls to start a new jump until they reach the external flange 44, where they are stopped in the third operative or equilibrium position.

In this case, both stages have snap or step action if the less widely opened cone 60 is designed as to give to this peculiar part of the governor a more inclined char acteristic than that of the spring.

To use the three equilibrium positions of said device in a practical way, any kind of control member may be used. For instance, a rod 62 may be disposed within and through the casing 64 of-said control mcmber, bearing against compression coilAspring 38. Three control positionsmay be provided, within casing64, as at A, B, C. Thus, as in the lposition of Figure `4, with masses 50, 5t) against plate portion 56,\rod 62 will operate through position A. When shaft 40 reaches the iirst specific velocity, masses 50 travel outwardly and against plate 52vat portion 58 thereof, rod 62 is snap or step shifted to position B. Similarly, when shaft 40 reaches the second specific velocity, masses 50, 50 bearing against conical surface 60 will move plate. 52 still furtheroutwardly and rod 62. will shift to position C against the further compression of spring 38.

As pointed out above, spring 38 and governor characteristic are such that as the governor speed increases from range to range, the spring will be overcome. suddenly each time, permitting the snap action change through rod 62.

The embodiments of Figures l, 2, 3 and 4 have in common the structural similarity that an adequate travel of the masses outwardly from the axis of rotation, when a specific speed of rotation is reached, is directly responsible for the snap-action through the angled faces of the axially shiftable plates and a correct inside diameter of cylinder 16. Sometimes it is diilicult to build the snap action only on the travel of the governor masses. ure 5 shows, for instance, how a governor having hinged masses may be disposed for snap action partly by the masses travel and partly by increasing the force of the axial component of the centrifugal force by an adequate design of a leverage system transforming the centrifugal force into said axial force.

In its general construction, the governor is of one well known type. Rotatable shaft 70 has fixed thereon, for rotation therewith, a collar 72 having radially extending split arms 74, 74 within which are pivoted masses 76, 76. The masses are pivoted otfcenter, with longer portions 77 extending rearwardly. The .shorter portions 78 have mounted at their front ends rollers 80, 8i). A circular plate 82 is provided, which may be fiat, as shown in Figure 5, but which, within the scope of the present invention, may be conical or curved (not shown) to add an additional effect to that of the linkage; plate 82 vhaving a recessed nose portion 84 slidably fitting over a shaft extension 86 in line with shaft 7i). A lever arm 88 is pivoted as at 90, lever S8 being swingable between a rear stop 92 and a front stop94. A compression coil spring 96 is provided, secured at one end to arm 88 and to a support 98 at its other end, spring 98 being normally biased to urge arm 88 towards stop 92 and nose 84. Plate 82 is axially slidable on shaft extension 86, but rotates therewith due to the slot and key connection as indicated at 99.

.lt is obvious that the electric ,signal 100 will not operate when the governor is closed, as in the position of Figure 5. When the governor opens, the angular motion of lever arm 88 completes the electrical circuit putting the signal in operation. A snap or jump action is necessary to insure a good make-and-break contact in the electrical circuit.

Spring 96 will function to maintain lever arm 88, nose 84, plate 82 and masses 76, 76 in the position of Figure 5 until the specific speed of rotation of shaft 70 is attained, at which time masses 77, 77, by pivoting about the ends of arms 74, 74, begin to swing outwardly. The masses 76 are so mounted and pivoted that upon the governor reaching its specific velocity the axial thrust of the centrifugal force on the weights 76 increases at a greaterrate than the opposing compression springV 96 Idue to both the increased centrifugal -force as the weights 77 swing outwardly and the increased mechanical ad vantage as the movementy of the roller 80 approaches a path parallel to the plate 82. Consequently upon `the governor reaching its specific velocity, the plate 82 and hence treme position of open contacts to the other extreme position of closed contacts.

When the contacts are lopen the center of gravity of Y the governormass 77 is positioned as indicated at R1, the

Fis-

. dotted line leading to the pivot 79 representing the effective torque arm of the mass 77. As the mass center of gravity rotates about 79 toiposition R2 the point of Vcontact between plate 82 and roller 80 has a decreasing torque arm which becomes zero when the line of pivot 79and pin 81 is perpendicular to the plane of plate 82. Up to this position the more R1 is displaced in the direction of Ra the more effective are the masses 77 incompressing spring 96.

The embodiment illustrated in Figure 5 is provided with a leverage system within the rotating portion of the governor in order to achieve suiicient axial thrust to overcome the initial and increased opposing force of the antagonistic spring in order to obtain the snap action between spaced equilibrium points. However, when space does not permit the use of governors of this type, the effective snap action can still be obtained in accordance with my invention by disposing between the spring and the governor a linkage of such construction so as to multiply'the effect of the movement of the governor control, in order to insure the characteristics illustrated by the shaded areas in Figure la.

This linkage structure can be incorporated within the governor, or associated with it externally. In Figure 5, the linkage structure is incorporated within the governor. In Figures 6 'to 12, the linkage is externally located, but associated with the governor'.

Sometimes it may be necessary to use a governor like a ball governor in which no internal variable leverage can be used, while a lack of space may not permit the mass travel necessary for the desired snap action. In this case, a suitable mechanism may be located outside of the governor and cooperate and be associated therewith, as shown on Figures 6 to l2.

the control lever arm 88 will jump from the exmeshes 7 In this case, the external leverage acts all along the axial travel, providing a mechanical advantage to the axial thrust or a disadvantage to the spring action in order to permit the axial thrust caused by the centrifugal `forces Y of the rotating `masses to increase -at a greater rate than the opposing antagonistic force thus effecting a snap or jump action between two equilibrium positions.r

in all of the devices of Figures 6 to 12, the centrifugal 1 force is developed within a shell as 110 secured to rotatrotational speedof shaft 112, control member 116 is shifted outwardly of shell 11i?. However, it should be noted that the centrifugal force of the balls 114 in the device illustrated in Figs. 6V and 7 does not, by itself, increase sutiiciently beyond the specific velocity to provide the snap action achieved earlier. Hence, a mechanism must be provided to eifect a snap or jump action between positions of equilibrium in response to a force or thrust increasing ata rate suicient to overcome the increasing7 antagonistic force of the spring. This mechanism is provided externally of the rotating portion of the governor. Figure 6l shows a two position governor whose Vsnap acdoes lever arm 144 between-stops 152, 154'. This construction dilers from that of Fig. 6 in the leverage arrangement-which provides al lever for the axial push and anotherfor the spring.. It is apparent from Fig. 7 that, due to the inclination of the push lever 164 andof the spring lever 168, the axial-motion, when thel governor overcomes the initial force of the spring 176, increases the effective length of the push and decreases the eliective lengthof the spring lever, thus effecting the desired snap or step action between two points.

in many installations, spring loaded centrifugal governors with snap action are lused with complementary equipment. This equipment must Vnot interfere with or prevent the desired snap-action, and, preferably, should complement same.

in 8 there is illustrated a single governor coupled with a leverage providing-three spaced stepped operative positions, that is operating with snap action at two specic velocities. This construction is valuable when the governor cannot be built directly for more than two positions. The governor is shown at its closed position; a T-shaped lever Silwith a normal extension 394i terminating in a roller'3tl6, is freely articulated on a fixed pin 306, and receives the governor axial push. A tension spring 398 with Ya fixed end 311i, is attached to a second levcr 252 freely articulated on a'iixed pin 316 yand this second lever'actuates the control member 2l?. by a linlr tionis obtained bythe provision of a mechanism of the VVaforesaid type in combination with a governor har/inginsuilicient'thrust per se.

in the embodiment illustrated in Fig. 6, .a bell-crank 1d@ is provided,I having angled v.arms 142, 144, the lever being pivotally fixed atv1r46. A tension coil spring 143,

securcdrto the end of arm' 314.2," urges arm 142 against plate lio, arm 142 having Ya. roller 154i at its end in rolling contact with plate '116. Thevother arm 144 is trapped letween two stops152, '154, and has a contact' member 156 at its free end. As the resistance of spring 14S is overcome by the movementV of platev116 under the inflnenceof masses 114, 114, Varm 144 is snapped over, about its pivot 146 for instance to complete a circuit between contact` 156 and a spaced contact 153.

in the above construction, the snap action is obtained upon the governor'reaching its specific velocity asa te# suit of the increasing centrifugal derived thrust as the weights move outwardly and of the increasing mechanical advantage ot the governor thrust over the antagonistic spring as the lever 142 is urged counter-clockwise. When the governor overcomes the initial force of the spring 148, the arm 142 rotates counter-clockwise about pivot 145 against spring 14S. However, this movement increases the component of the governor thrust acting in opposition to the antagonistic spring 148 at a greater rate than the increased tension of the spring due to the change in ther'evolving angle of said thrust. This results in a v jump ofthe shell 116, crank 140 and contact 156 from its initial equilibrium position to a second extreme position l Vof equilibrium.

In Fig. 7, there is illustrated another embodiment of the present invention of the type illustrated in Fig. 6 in which a snap or jump action between twoequilibiium extreme positions is Vachieved by means of a suitable variable mechanical advantage mechanism.' In this alternative construction, an armed lever or crank 161) is pivoted at 162, and has arm 16d;- with a roller 166 at its end bearing against platell, and an arm l at the other side bearing against a compression coil spring 170 bearing against a support 15). The middle arm 182 is provided with a contact 184 acting as control member of the governor and in line with a contact 18S of an electrical circuit (not shown), branch 182 pivoting between stops 186, 188 as 250. Along the edge of lever 252 which confronts lever 3190, there are several spaced elevated fulcrum points 3ft?. and 314. Whcnthe governor velocity, is below the lowest specii'ic velocity. both levers t'a'lie the position shown in Fig. 8, lever 252 engagingy the lever Zilli through the fulcrumZ and stopped oy the hubv of said lever, due to spring action. rihe location of fulcrum` 312 and the characteristics of spring 333 arersu'ch that when the tirst specific velocity is reached; thefgovcrnor axial thrust rotates bothrlevcrsyand said levers rotate about their respcctivepivots and at the same timecan be regarded as having angularV motion toward eachother about the movable ulcrum-312 such that the fat faces forming an acute angle with fulcrum 312 as a vertex suddenly snap together' in-a manner similar to the action of elements 24:8 and 252 whichl are shown open in Figi?. and closed in Fig. 1l., At the higher specific velocity,`both levers are rotated'again, but this time through the fulcrum 31.4, and assumes the position shown in Fig. l2. The location of the fulcrums 312 and 314 determines the higher specific velocity relatively tothe lower specific velocity.

As can vbe seen in Figs. 8, ll and l2, the successive snap orstep actions at the first specific velocity about fulcrum 312 and at 'the second specific velocity about fulcrum 314i is achieved as a result of both the increased centrifugal derived thrust as the weights move outwardly and ofzthe increasing mechanical advantage of the goveiner thrust over the force of the antagonistic spring as the shell advances axially. ln thc lirst step the thrust transmission is through the fulcrum EEZ andin the second step it is through the fulcrum 314i. As above set forth, the characteristics of this system is determined by the configuration of the levers, the location of the ul crums, -the position and strength of the spring and the y characteristics of' the rotating portion of the governor.'

Some applications require a variable specific velocity withina given range as, for example, in snap-action governors for use in automatic automotive transmissions. Fig.,9 illustrates a snap-action governor with externally located cooperating linkage as applied to an automotive transmission with two ditferent drive ratios, requiring al 9 erative velocity is to add to the spring loaded governor 110 an auxiliary control device such as a vacuum operated diaphragm which is responsive to the degree of vacuum in the engine intake manifold and is a measure of the' power required by the drive of the automobile at a given time.

Referring to Fig. 9, the governor 110 is mounted on a rotatable shaft 112 of the drive transmission preferably connected to the driven shaft. Near its center, or apex, governor control member 126 is flattened, and bears against a roller 262 mounted at the end of arm 204 of the bell .crankl which is rotatably pivoted by means of pin 206. A tension spring 208 connects the end of arm 204 to a fixed point 2id, and is obliquely mounted urging the bell crank 200 in a clockwise direction. The actuation of lever 200 by governor 110 is as described with respect to Fig. 6.

Assuming that control of the transmission is effected through a control device 210, as for cxainple, an hydraulic oil distributor, having a laterally slidable 4rod 212, as the valve of said distributor, rod 212is connected by link 214, to arm 216 of the bell crank 290. As the governor control member 116 moves from one operative position to another, control rod 212 is, or should have, two spaced operating positions which may correspond to two drive transmission ratios. If the spring-loaded governor 110 were the only means to cause change from one operative position to the other, this change would aways occur at `the same predetermined R. P. M. and at the same specific angular velocity w. The down shift would aways occur at a little below w. v

The governor 110 and spring 208 are preferably so constructed that the angular velocity w corresponds to the minimum of car velocity at which the shifting is desired. VTo Vprovide the upper specitic velocity W, another tension spring 236 is added, with one .end secured 4to a fixed point 238 and the other end attached to a lever 232 freely articulated on pin 266 on which leverr 200 also is'frree to rotate." To transmit the force .of spring 236 to the governor,` lever 232 has a shoulder 234 which is bent to engage the edge of arm 204 whereby a-clockwise force may be imparted to crank 260 in addition to that of spring 20S. 4

The vacuum equipment 222 is used to obtain all specific velocities between w and W, in operating the control 210. A closed chamber 222 is separated into two parts by a flexible diaphragm 226, with the left part connected to the intake manifold by a pipe 224, the other part-being under atmospheric pressure. VThe guide 228 of the diaphragm is connected by a link 23d to lever 232, in such a manner as to have the torce created by the vacuum actingagainst the spring 236. Due to shoulder 234, the vacuum force cannot act on the governor', nor on spring 208, but only reduce the action of spring 236. l

When the engine is operating at full power, throttle wide open, there is no appreciable vacuum in chamber 222, and both springs exert their full strength against lever arm 204. The shifting occurs at velocity W. When the engine is operating at less than full power, throttle .only part open, there is some degree of vacuum in chamber 222. The force of the vacuum exerts a pull on rod 228, link 230 and lever arm .232, thereby removing some degree of pressure from spring 236 upon lever arm 204. Thus, the main crank .200 will jump from one to the other Yof its equilibrium positions at a lower angular velocity. If engine load is small enough because the throttle is lightly depressed, the vacuum in chamber 222 is sufficient to overcome spring 236 and eliminate completelythe effect of said spring as any factor in the spring loading of lever 204. Under such conditions, only spring 208 will be effective and the shift will occur at the predeterminedvnumber of R. P. M. w. And all intermediate `shifting velocitiesare possible becauserthe vac uum force can take any intermediate value between its maximum and. its minimum.

Athe governor when the upper specific velocity is If improperly designed, the vacuum may disturb the governor snapaction. At a given engine or car velocity and at a given throttle opening, the rate of the vacuum is constant all along the control member stroke while the strength of spring 236 increases when the governor opens. This would interfere with the snap-action. To correct this situation, it is desirable to provide to the subassembly comprising the vacuum device, lever 232 and spring 236 a decreasing mechanical advantage as the motion advances to help the internal motion of said sub-assembly. This is obtained by any of the means explained before, for instance by a convenient Obliquity given to both link 230 and spring 236 relatively to lever 232. Rods 230 and 260 may be controlled by the throttle or accelerator pedal rather than by engine manifold vacuum acting upon diaphragms 226, if desired.

It is obvious in Fig. 9 that the increasing effective arm lever of the vacuum force when the governor opens, and the decreasing effective arm lever of the spring encourage the snap or jump action of the system due to the variation ot' interposed levers as explained. Outside of vacuum chamber, lever and spring, all other parts operate as explained for Figure 6.

ln cases where a transmission controlled by a governor has more than two ratios, three or more, the governor must be provided with three or more operative positions in addition to the variable speed disposition explained on Figure 9.

in Fig. l() is illustrated a three position governor arrangement for a three ratio transmission including the variable speed dispositions by vacuum with parts similar to other figures Abeing similarly numbered. An inverted bell crank 240 is pivoted at 242. One arm 244 has a roller 246` at its end bearing against governor plate 116. The other, arm 248 of crank 240, normally depends at substantially right angles to shaft 112 at its rest position. This construction is an equivalent of the T-shaped lever 300 of Fig. 8. Control mechanism 210 has shaft 212 projecting therefrom and connected by link 250 to an arm 252 of a bell crank 254 provided with an integral arm 258.v Diaphragm rod 228 is connected to a link 260 which is pivoted to lever 263 which in turn is pivoted 'to thel joint of crank 254. The lever 268 is provided with projecting ledge 270 bearing on arm 258. Tension coil springs 272, 274' are secured to arms 26S and 25S, and to fixed pins 276, 278 respectively. As governor plate 116 is shifted outwardly on increase in rotation of shaft 112, acting on lever arm 244, lever 240 pivots about 242 and arm .248 is swung against a corner 312 of an outwardly extending shoulder 280 on arm 252 said shoulder having sharp corners or fulcrums 312 and 314. The first Vposition of the parts is illustrated in Fig. l0. This position corresponds to a governor velocity below the lower specific velocity. The second position is illustrated in Fig. ll, with arm 248 lying atly against shoul* der y280 of arm 252, at which point control rod 212 is shifted vone vunit into sub-assembly 210. This position is obtained when governor velocity is between both specific velocities. As the lever arm 244 is further actuated by reached, arm 248 shifts to the position illustrated in Fig. l2, pivoting about the corner of shoulder 280 moving control 212 still -further into the sub-assembly 212, the three control Lpositions being indicated, for instance, at I, K and L (Fig. l0).

All of the governors may be provided with restoring springs to return `them to a position of low or zero speed of rotation. However, spring 308 preferably returns cone 116 as the governor force decreases. Spring 96 can likewise return masses 77 unless R2 is permitted to move beyond the point where the line of 79-81 is perpendicular to plate 82 so as to lock. The masses 7'7 vcould then be restored by a vspring acting between them or manually lwith a lever controlled by the operator. Normally the position Rz is sutiicient to close the contacts of circuit 10G and spring 96 can restore the masses 77. In Fig. 7

grasses as the governor force drops with the contacts 184, 85 closed, spring 7i) rotates arm lSZ clockwise and restores governor lill?. Spring MS has thesame action in Fig. 6 and also spring 20S `in Fig. 9 andspring 274 in Fig. 10. The governor devices aretprimarily automatic control means and are self-restoring- This structure is a combination of the multi-position device shown in Fig. 8 with the variable velocity disposition explained in Fig. 9. Thus, all complementary explanations given for such figures apply here, as apply all precautions to be taken relatively to multiple positions and vacuum levers. The result is a multiple position yand variable angular velocity governor with snapaction not impaired in'any way by any of the additions imposed upon by the special use o1" the governor.

lu summary, snapwaction can be built completely inside of any kind of governor by designing the travel of center of gravity of masses long enough in accordance to the spring increase; this way, the snap-action results from an increase of radius of center of gravity of masses which is faster than the increase of the force of thc antagonistic spring all along the axial motion of the governor. This applies as well to single governors with two operative positions, Fig. l, or with more than two positions, Fig. 4, or to'more complicated governors like those shown in Figs. 2 and 3.

lf the travel of the masses cannot be built up enough to provide the wanted snap-action, an increase of the governor axial push relatively to the centrifugal force can be produced in some kinds of governors by simple alteration of the internal leverage transforming the centrifugal force into the axial push ofy the governor-cxample, 1Eig. 5, relative to a hinged governor.-

lf both adequate masses travel and internal leverage cannot be designed as to insure completely the wanted snap-action, then an external variable leverage has toV be used. Figures 6 and 7 show this solution for a single A governor having two operative positions and Fig. 8 lfor a single governor completed by a lever device conferringl to it more than two positions.

if one or several variable operating velocities are needed, and special devices added to the governor for this purpose, these devices like the multi-position mechanisms, mustV not bring trouble to the snap-action and have to be carefully checked. The correct mounting of a variable velocityl mechanism in supplement to yan external snapaction leverage is shown in Figure 9 with a single two position governor.

Gf course. some precautions have to be taken with any multiple position device; Figures l0, ll and l2 show how to assemble correctly a variable velocity mechanism and a multi-position device with a single governor provided with an external snap-action leveraget I claim:

l. A governor mechanism of the type described comprising a rotatable member, a weight eccentrically mounted relative to the axis of rotation of said member and adapted to rotate therewith, said member being provided with aradially extending guide engaging said weight and restricting the path of movement thereof, a thrust member axially slidable relative to said rotatable member and having a portion thereof registering with said guide and sloping toward the opposing portion of said guide as said portion extends radially outwardly, a varying mechanical advantage link mechanism and biased spring means having a characteristic constant selected to provide a first rate of force increase and acting through said link mechanism urging said thrust member toward said rotatable member whereby said sloped portion bears against said weight, the

relative angle of said sloped portion with respect to theV axis of rotation being such that for a velocity of rotation of said weights equal to the specific governor velocity for the combination, thc reactive force required to be exerted on said conical surface to maintain the weights in position increases at a rate greater thanrsaid 'first rate of force l2 increase, said angle of slope and the characteristics of said link mechanism and said spring means being such that upon said rotatable member rotating at a predetermined speed the thrust imparted to said thrust member by said weights as a result of the centrifugal force thereof is sutiicient to overcome the opposing thrust of the spring means through said link mechanism causing said thrust member to recede from said rotatable member and permitting said weight to move radially outward, the rate of increase of the thrust due to the increased centrifugal force on said weights as they move outwardly and the increased mechanical advantage of said link mechanism in favor of said thrust member being greater than the rate of increase of thrust of the opposing spring means thereby resulting in said thrust member jumping in snap fashion from its initial point to a second point of equilibrium where lthe force opposing further axial movement of the thrust member is at least equal to the centrifugal force derived thrust, said link mechanism comprising a pivoted bell crank having one arm bearing against said thrust member and the other arm connected to said spring means whereby upon rotation of said bell crank by said thrust member the moment arm and relative tangential component of the thrust of said thrust arm increases and the moment arm and relative tangential component of said spring means decreases and wherein means are provided for varying the loading of said spring means in response to a predetermined control.

with a radially extending guide engaging said weight and restrictingthe path of movement thereof, a thrust member axially slidable relative toV said rotatable member and having a portion thereof registering with said guide and sloping toward the opposing portion of said guide as said portion extends radially outwardly, a varying mechanicalV Y advantage link mechanism and biased spring means having a characteristic constant selected to provide a first rate of force increase and acting through said link mechanism urging said thrust member toward said rotatable member whereby said sloped portion bears against said weight, the relative angle of said sloped portion with respect to the axis of rotation being such that for a velocity of rotation of said weights equal to the specific governor velocity for thecombination, the reactive force required to be exerted on said conical surface to maintain the weights in position increases at a rate greater than said first rate of force increase, said angle of slope and the characteristics of said link mechanism and said spring means being such that upon said rotatable member rotating at a predetermined speed the thrust imparted to said thrust member by said weights a-s a result of the centrifugal force thereof is suflicient to overcome the opposing thrust of the spring means through said link mechanism causing said thrust member to recede from said rotatable member and permitting said weight to move radially outward, the rate of increase of the thrust due to the increased centrifugal force on said weights as theyy move outwardly and the iucreased mechanical advantage of said link mechanism in favor of said thrust member being greater than the rate of increase of thrust of the opposing spring means thereby resulting in said thrust member jumping in snap fashion from its initial point to `a second point of lequilibrium where the force opposing further axial movement of the thrust member is at least equal to .the centrifugal force derived thrust, said link mechanism comprising a pivoted bell crank having a plurality of spaced fulcrum points on one arm thereof and having the other arm connected to said spring means, and a pivoted lever bearing against said thrust member and engaging one of said fulcrum points furthest removed from the pivoted end of said bell crank when said governor mechanism is in rest `position and engaging at said second point of equilibrium another of said fulcrum points more closely spaced to the pivoted end of said bell crank the force of the thrust member being insufficient, at said predetermined speed, to overcome the force of the loaded spring means through said other fulcrum point but upon said weights being rotated at a second greater predetermined speed -said thrust member jumps in snap like fashion to a third equilibrium position in a manner similar to the action from said initial position to said second equilibrium position.

3. A governor mechanism of the type described comprising a rotatable member, a weight eccentrically mounted relative to the axis of rotation of said member and adapted to rotate therewith, said member being provided with a radially extending guide engaging said weight and restricting the path of movement thereof, a thrust member axially slidable relative to said rotatable member and having a portion thereof registering with said guide and sloping toward the opposing portion of said guide as said portion extends radially outwardly, a varying mechanical advantage link mechanism and biased spring means having a characteristic constant selected to provide a first rate of force increase and acting through said link mechanism urging said thrust member toward -said rotatable member whereby said sloped portion bears against said weight, the

relative angle of said sloped portion with respect to the axis of rotation being such that for a velocity of rotation of said weights equal to the specific governor velocity for the combination, the reactive force required to be exerted on said conical surface to maintain the weights in position increases at a rate greater than said first rate of force increase, said angle of slope and the characteristics of said link mechanism and said spring means being such that upon said rotatable member rotating at a predeter mined -speed the thrust imparted to said thrust member by said weights as a result of the centrifugal force thereof is suiiicient to overcome the opposing thrust of the spring means through said link mechanism causing said thrust member to recede from said rotatable member and permitting said weight to move radially outward, the rate of increase of the thrust due to the increased centrifugal force on said weights as they move outwardly and the increased mechanical advantage of said link mechanism in favor of said thrust member being greater than the rate of increase of thrust of the opposing spring means thereby resulting in said thrust member jumping in snap fashion from its initial point to a second point of equilibrium where the force opposing further axial movement of the thrust member is at least equal to the centrifugal force derived thrust, said link mechanism comprising a pivoted bell crank having a plurality of spaced fulcrum points on one arm thereof and having the other arm connected to said spring means, and a pivoted lever bearing against said thrust member and engaging one of said fulcrum points furthest removed from the pivoted end of said bell crank when said governor mechanism is in rest position and engaging at said -second point of equilibrium another of said fulcrum points more closely spaced to the pivoted end of said bell crank the force of the thrust member being insufiicient, at said predetermined speed, to overcome the force of the loaded spring means through said other fulcrum point but upon said weights being rotated at a second greater predetermined -speed said thrust member jumps in snap like fashion to a third equilibrium position in a manner similar to the action from said initial position to said second equilibrium position, and auxiliary second spring means responsive to a control device for imparting a supplementary variable moment to said bell crank in the same direction as said first spring means thereby to correspondingly vary said first and second predetermined snap activating speeds.

4. A governor mechanism of the type described comprising a rotatable member, a weight eccentrically mounted relative to the axis of rotation of said member and adapted to rotate therewith, said member being provided with a radially extending guide engaging said weight and restricting the path of movement thereof, a thrust member axially slidable relative to said rotatable member and having a portion thereof registering with said guide and sloping toward the opposing portion of -said guide as said portion extends radially outwardly, a varying mechanical advantage link mechanism and biased spring means having a characteristic constant selected to provide a first rate of force increase and acting through said link mechanism urging said thrust member toward -said rotatable member whereby said sloped portion bears against said weight, the relative angle of said sloped portion with respect to the axis of rotation being such that for a velocity of rotation of said weights equal to the specific governor velocity for the combination, the reactive force required to be exerted on said conical surface to maintain the weights in position increase at a rate greater than said first rate of force increase, said angle of slope and the characteristics of said link mechanism and said spring means being such that upon said rotatable member rotating at a predetermined speed the thrust imparted to said thrust member by said weights as a result of the centrifugal force thereof is sufficient to overcome the opposing thrust of the spring means through said link mechanism causing said thrust member to recede from said rotatable member and permitting said weight to move radially outward, the rate of increase of the thrust due to the increased centrifugal force on said weights as they move outwardly and the increased mechanical advantage of said link mechanism in favor of said thrust member being greater than the rate of increase of thrust of the opposing spring means thereby resulting in said thrust member jumping in snap fashion from its initial point to a second point of equilibrium where the force opposing further axial movement of the thrust member is at least equal to the centrifugal force derived thrust, said link mechanism comprising a pivoted bell crank having a plurality of spaced fulcrum points on one arm thereof and having the other arm connected to said spring means, and a pivoted lever bearing against said thrust member and engaging one of said fulcrum points furthest removed from the pivoted end of said bell crank when said governor mechanism is in rest position and engaging at said second point of equilibrium another of said fulcrum points more closely spaced to the pivoted end of said bell crank the force of the thrust member being insufficient, at said predetermined speed, to overcome the force of the loaded spring means through said other fulcrum point but upon said weights being rotated at a second greater predetermined speed said thrust member jumps in snap like fashion to a third equilibrium position in a manner similar to the action from said initial position to said second equilibrium position, and auxiliary second spring means responsive to the pressure in the intake manifold of an internal combustion engine for imparting a supplementary variable moment to said bell crank in the same direction as said first spring means thereby to correspondingly vary said first and second predetermined snap activating speeds.

References Cited in the file of this patent UNITED STATES PATENTS Re.21,844 Vetter June 24, 1941 1,135,054 schacht Apr. 13, 1915 1,137,110 Balough Apr. 27, 1915 1,844,674 Norris Feb. 9, 1932 2,088,427 Maurer July 27, 1937 2,109,615 Durham Mar. 1, 1938 2,187,207 McCabe Jan, 16, 1940 2,207,340 Claus July 9, 1940 2,306,696 Hale Dec. 29, 1942 2,341,624 Kieser Feb. l5, 1944 2,430,799 Aspinwall Nov. 11, 1947 2,495,617 Wallace Ian. 24, 1950 FOREIGN PATENTS 465,593 Germany Sept. 26, 1928

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