US2325009A - Governor - Google Patents

Description

July 20; 1943. A. KALIN 2,325,009

e ovrmuoa Griginal Filed March 26, 1941 3 Sheets-Sheet 1 INVENTOR ALBERT KALIN ATTORNEY A. KALIN GGVERNQR Griginal Filed March 26, 194i 3 Sheets-Sheet 2 ATTORNEY July 20, 1943. A. KALIN GOVERNOR Original Filed March 26, 1941 3 Sheets-Sheet 3 Fag-3 "WEN-ken ALBERT KALIN ATTORNEY Patented July 20, 1943 UNITED STATES PATENT Divided and this application Septem ber 10, 1941, Serial No. 410,284

3 Claims.

This application is a division of my application Serial No. 385,228 flied March 26, 1941. In the parent application there is shown a governor for prime movers and other machinery substantially according to my Patent 2,219,229 issued October 22, 1940. Said governor, as in the patent, operates through a hydraulic fluid system including a servo-motor piston and cylinder, under the control of a pilot valve and weighing means, to regulate for instance speed of a Diesel engine to hold the speed constant notwithstanding variations in load on the engine.

The governor has an accumulator system operable automatically to maintain constant posi tive pressure in the hydraulic system so long as the governor and a suitable pumping system arranged to supply the governor with hydraulic fluid are driven by the-engine. The accumulator is spring loaded for operation such as to maintain the desired constant pressure in event of overdelivery by the pumping system and when the engine has been idle for a short time (sometimes a few seconds) the pressure is usually reduced to a low value by operation of the accumulator spring or springs and seepage of hydraulic fluid past various coacting working parts, notwithstanding close clearances between said parts. The hydraulic fluid in shutting down, as in the governor shown in the parent application, may purposely be dumped from the regulating servomotor and connected fluid passages, requiring recharging before the engine can be restarted. Upon restarting, because of initial lack of working hydraulic pressure, at least some time must elapse before the governor can take full control of the engine. This sometimes makes the operation of starting of the engine take longer than it should (e. g. more time than available in certain circumstances) and usually results in waste of starting power (e. g. air supply),

The provision of means separate from the governor to supply hydraulic fluid to the governor at suitable pressure in order to meet the problem outlined above is already known in the art; but, so far as I know, it has not previously been proposed to provide boosting hydraulic pressure means as part of the governor mechanism. The present arrangement utilizes air (or other elastic fluid maintained under pressure for starting pur poses) in a special servo-motor, built into the multaneously with or prior to performing the op- The mechanism comprising the principal subject matter of this application will usually be referred to herein for convenience as a booster-servo.

Another object is to provide a booster-servo cylinder and piston mechanism having shock absorbing means operable in event there is an insufficient supply of hydraulic fluid in the boosterservo cylinder 'when operation of the booster- I servo takes place0r in event the actuating (e. g. air) pressure for the booster-servo is excessiveto damp or cushion said operation.

A further object is to provide a booster-servo mechanism arranged to enable air at high pressure to be used to build up initial oil pressure in a governor, wherein the air and oil have no possibility of becoming mingled in a manner such as might cause improper operation of the gov ernor or an explosion-as will be more fully explained later herein.

Other objects and advantages of the invention will become apparent from the following description of a preferred form thereof, as shown in the drawings, in which:

Fig. 1 is a central sectional view of a speed governor incorporating the invention; Fig. 2 is a plan view of the governor, and Fig. 3 is a vertical sectional view thereof taken as indicated at 3--3 on Figs. 1 and 2.

In the governor mechanism shown herewith as one type of governor on which the booster-servo mechanism may be used, I (Figs. 1 and 3) is a base adapted to be mounted on an engine to be governed, 2 a power case surmounting the base, 3 a regulating servo-motor cylinder block attached as at one side of the power case, and 4 a speeder case for the speed responsive or weighing mechanism and adjusting means therefor.

A shaft Hi, to be drivingly coupled to the engine, is supported in the base as by a bearing H above which is an oil seal I2. The shaft carries a pump gear iii in a suitable pump chamber formed in the power case as shown in my said patent (the cooperating gear not being shown herein), and the pump is provided with a suitable reversible valve system, one of each of two pairs of valves being indicated at 23 and 24 respectively, for enabling the pump to draw hydraulic fluid from a sump S in the power case and speeder case (normal fluid level at L) which communicates with a pump inlet chamber It in the base.

During rotation of the shaft III by the engine, hydraulic fluid is maintained under constant operating pressure in ducts or passages I5, l6 and ii in cooperation with spring loaded accumulators (not shown) located at opposite sides of the passage l6 and communicating with the duct I6 as by cross passages one of which is indicated at H! (leftFig. 1). The accumulators maintain uniform pressure in the ducts l5, I6 and l l in the event of overdelivery by the pumpexcess fluid being discharged to the sump essentiallyi, as in the arrangement shown in said patent. Hydraulic fluid supplied to and maintained at the bore I! under constant pressure is controlled by operation of a pilot valve (plunger 20, sleeve 2| and other elements to be described later) to efiect movement of a servo-motor piston 22 in the proper direction to regulate the speed of the engine.

The pilot valve sleeve 2| is tightly fitted into a central vertical cylindrical bore 30 in a central portion of the power case which completely surrounds the valve sleeve. The valve sleeve has a cylindrical axial bore 3| which is open at both ends of the sleeve and in which various land portions of the pilot valve plunger are slidably fitted and enabled to rotate while maintaining respective lateral portsof the sleeve sealed, as will be apparent. The plunger has two main lands 25 and 26. The lower land 25 normally seals ports 28 of the pilot valve sleeve (open to constant pres- I sure at the bore IT) with reference to the central bore of said sleeve. The upper land 26 normally seals ports 29 of the pilot valve sleeve (open to the sump) against communication with the central bore of the sleeve. A neck portion 35 of the pilot valve plunger maintains an open space between the valve plunger and valve sleeve which; communicatesat all times with a duct 36 which, in turn, communicates freely with the lower end portion of the servo-motor cylinder, i. e. below the enlarged portion 31 of the servo-motor piston 22. The ports 28 of the sleeve which are normally blocked by the land 25 communicate freely at all times with the servo-motor cylinder ,above the piston portion 31 through a duct 38.

The reduced upward end 39 of the servo-motor piston slidably closes the upper end of the servomotor cylinder and reduces the effective area of the servo-motor piston relative to the lower eifective area of the piston, so that, with the same pressure admitted to the cylinder above and below the piston portion 31, the piston moves upwardly. l The piston has a power connection (regulating rod 40) extending downwardly out of the servo-motor cylinder block through a suitable sealing ring in a head member 42 to enable regulation of the governed engine.

Downward movement of the servo-motor piston reduces and eventually cuts ofi power input to the engine; and upward movement admits and increases such power input.

When the pilot valve plunger 20 is moved downwardly from its normal (illustrated) position, the land 25 opens the ports 28 to theinterior of the valve sleeve 2!, whereupon constant pressure from the bore l1 around the sleeve is admitted to the duct 36 past the neck 35 of the valve plunger; and the servo-motor piston is raised due to the area difierential of said piston.

When the pilot valve plunger is raised, the land 261by opening the ports 29 to communication with the interior of the valve sleeve 2l dumps operating fluid from the servo-motor cylinder below the piston portion 3'! to the sump through the duct 36, valve sleeve bore 3| and ports 29; and constant pressure from the bore I! through the duct 38 to the upper side of the pis- 0 wall portion around the flyton portion 31 then causes lowering of the servomotor piston.

The pilot valve plunger is maintained in the position shown, holding the servo-motor piston against movement, during normal operation of the engine, by reason of the operation of a flyball mechanism including a speeder spring 5| and fly-balls 52 pivoted on a rotary ball head 53. The fly-ball arms 54 bear upwardly at their" inner ends on a thrust member 55 rigid with the pilot valve plunger, tending to raise the plunger as the speed of the engine increases; but (e. g.), so long as the load on the engine remains constant at a given setting of the speeder spring, the downward force of the spring on the valve plunger holds said plunger against upward movement,-in other words in balanced position to maintain both lands 25 and 25 in closing rclation to their respective ports. Friction of the ball-arm fingers on the thrust member 55 causes the pilot valve plunger to rotate with the ball head during the entire operation of the governor.

The connection between the speeder spring and pilot valve plunger 20 may comprise an antifriction bearing assembly as in my Patent 2,219,229, which enables free rotation of the pilot valve plunger and non-rotation of the speeder spring.

The ball head 53 is journaled for rotation on a reduced upper end portion 56 of the pilot valve sleeve 2|. A depending hub portion 51 of the ball head which surrounds said portion 56 of the valve sleeve has gear teeth 58 which mesh with a driving gear not shown on a vertical shaft, the lower end of which is drivingly rigid with the pimp gear which cooperates with the pump gear in said patent. The ball head 53 has a circular balls which supports a sleeve 63 extending upwardly around the flyballs and having an inturned flange 64.

Isochronousoperation of the governor requires primary and secondary compensation, as is well known. The compensation system shown herein is essentially the same as that of the above identified patent and reference is directed to said patent for a more complete discussion of the same than given herein. Primary compensation is efiected hydraulically as a function of servomotor piston movement; and restrains the axial movement of the pilot valve in its operation to initiate movement of the servo-motor piston, thus preventing overtravel of said piston'both in reducing and increasing power input to the engine.

For primary compensation, fluid is moved in a compensation fluid duct 10 which extends through various parts essentially the same as in my said patent. A hollow piston H fixed to the upper end of the servo-motor block 3 operates in an axial bore 12 of 'the servo-motor piston 22 so as to serve as an actuating compensation pump in increasing and decreasing pressure at a space 13 below the pilot valve sleeve 2! and within the closed lower end of the bore 30 of the power case. The compensation fluid duct 10 is normally kept full of operating fluid from the sump through lateral holes 14 in a sleeve 74' (above servo-motor) the bore of which sleeve has restricted-communication with the compensation duct 10 at the upper end of the hollow piston 7|. The holes 74 are open outwardly to the sump in the speeder case. I

When load on the engine drops the fiy-balls move outwardly, thus raising the pilot valve This ball head drive is the same as shown .or the rack bar in the relative adjustment of parts plunger. As the pilot valve plunger is moved upwardly from its normally centered positioninitiating a downward or power input reducing movement of the servo-motor piston-suction on the fluid in the compensation fluid duct tends to evacuate the space 13' below the pilot valve sleeve. This acts, hydraulically, yieldingly to restrain the upward movement of the -pilot valve plunger, by virtue of a receiving compensation piston 15 connected to the pilot valve plunger by means of a coil spring 16 capable of imparting reversible restraining action on the plunger and capable of causing the piston I5 to turn with the valve plunger in the valve sleeve. The restraint (primary compensation) is only temporary because. as soon as the servo-motor piston starts to move downwardly, fluid begins to leak into the compensation duct (secondary compensation) from the sump at holes I4 and th restricted communication thereof with the compensation duct. The rate of leakage is regulated by an adjustable needle valve pin 18 between the holes 14 and the compensation duct. The space between the receiving compensation piston I5 and the pilot valve plunger communicates freely with the sump space of the power case.

Upon increase of load, resulting in a lowering movement of the pilot valve plunger, the reverse of the above described action takes place. The resulting upward or power-input-increasing movement of the servo-motor piston moves fluid in the compensation fluid duct [0, raising or tending to raise the receiving compensation piston 15, thereby to restrain the lowering movement of the pilot valve. Secondary compensation (leakage through the restriction at the needle valve 18) removes the restraining action of the compensation piston I5 on the pilot valve plunger as the speed is brought back to normal; but the direction of fluid leakage is reversed. Fluid leaks from duct 10 into the sump.

The above described arrangement in general is the same as that of my Patent 2,219,229, and the operation thus far is also essentially the same as in said patent.

Speed adjustment A speed control lever 80 extends diagonally of the speeder case in a horizontal plane as shown, by Fig. 2. The lever has an adjustable-trunnion connection with the speeder spring in the form of a block 8| (cylindrical sleeve) pivoted on aligned pins 82 which are carried by spaced portions of the lever, and anadjustable screw 83 in the block which bears downwardly on the speeder spring and may be locked in place in the block as by a nut 84 engaging the block. The right hand end of the speed adjusting lever 80 is supported-by a horizontal shaft 88 mounted in the speeder case as on pivot bolts 89 (Fig. 2), the

lever 80, as shown, being suspended from the shaft by a link 85 pivotally carried on a mounting assembly 88 concentric with the axis of the shaft. The mounting assembly shown includes parts I60 and I88 which are unessential so far as the invention claimed herein is concerned-I60 being a pinion adapted to be turned by teeth on a rack bar I6I supported as at I62 and extending to the upper end of the servo-motor piston 22, being held in contact with said piston by a spring I64. The vertical motion of the rack bar. as fully explained in the parent application, can be made to change the elevation of fulcrum of the speedadjusting lever (for speed droop adjustment) but said elevation will not be changed by said motion 88 and I illustrated.

I Power head As shown in Figs. 2 and 3 the end of the speed adjustment lever 80 opposite the fulcrum (i. e. left end. Fig. 2) is pivoted to an upright stem 90 of a power head piston 9| which operates in a vertical cylinder bore 92 formed in the speeder case, a portion of which latter (240) may extend below the top of the power case as showrr in Fig. 1 to accommodate the power head. The stem 90 is slidably guided for vertical movement in a cap 93 closing the upper end of the power head cylinder bore 92. The left hand end of the lever 80 is bifurcated to straddle the stem 90 and is provided with axially aligned horizontal pins 94, the proximate ends of which pivot in a ring 95 clamped to the upper end of the power head piston stem 90.

The power head piston is actuated hydraulically and is controlled by a follow-up valve the stem of which is shown at 96 within an axial bore of the piston stem 90, so that the piston moves up and down with the valve, 1. e. as the valve stem is moved up and down. The valve admits fluid from a constant pressure source (described later) into operative relation to the piston for movement of the latter up and down exactly as the valve stem 96 is moved. The

valve requires very little power to operate it, and thus the power required for changing speed, manually or by a Selsyn motor, may be made independent of the variable resistance of the speeder spring in opposing speed adjustment. "Constant pressure is applied to the upper side of the power head piston 9| (Fig. 3) to move the piston downwardly, through a duct comprising a vertical bore I00 (left Fig. 1) in the power case communicating with the bore I'l thereof, and bores in the speeder case comprising diagonal bore IOI, vertical bore I02 and a horizontal bore I03. The latter is shown in Fig. 3 connecting the upper end of the power head cylinder 92 with the vertical bore I02. The same pressure is applied to the lower piston face (larger) to move the piston upwardly as will be shown presently.

The power head valve is a cylindrical plug I05 on the lower end of the valve stem 08, which latter does not seal the bore 97 of the piston stern abovethe plug, whereas the plug is in sealing relation to the portion of the bore in which it slides. The plug I05 normally blocks two lateral ports I01 and I08 in the stem of the power head piston 9|. The port I0! communicates freely with the power head cylinder below the piston 9| through a duct I09; and the port I08 communicates directly with the effectively smaller cylinder above the piston. 9|. When the plug I05 is moved downwardly by the speed setting mechanism, fluid from the cylinder 92 below the piston 9I is vented to atmosphere along the valve stem 96, i. e. between it and the piston stem 90, whereupon pressure applied above the piston (smaller effective area) moves the piston downwardly until the plug again blocks the port I01. Similarly when the plug I05 is raised it unblocks the port I08 admitting constant pressure to the lower end of the power head cylinder 92, thus raising the piston to whatever extent the plug I05 has been raised and then blocking the port I08, stopping further upward travel of the piston.

Power head operating mechanism For operating the power head valve stem 96 there is provided, as shown in Figs. 2 and 3, a bell crank H pivotally supported on a horizontal shaft III in the speeder case. The bell crank has a horizontally extending bifurcated arm I I2 provided with a pin and slot connection H3 with the upper end of the said valve stem. An upstanding arm H4 of the bell crank has a yielding lost motion connection (compressible link, including a spring I I5 and bar I IS) with an arm H1, which latter is keyed to a speed adjustment shaft H8 suitably mounted in the speeder case parallel to the shaft III and at the right thereof (Figs. 1 and 2). The bar H6 is pivotally pinned to the arm H1 at H9 and has a slot I slidably embracing a pin I2I on the bell crank arm H4.

A clamping means I33 holds the arm I on the shaft H8. The shaft H8 may carry an adjusting arm I30 having an operating wheel I and mechanism (not shown) connecting the wheel with a fixed quadrant bar I31 for angular adjustment of said shaft. A friction detent spring I on the arm slides against the quadrant bar.

For increased speed adjustment the shaft H8 is rotated counterclockwise as viewcd.in Fig. 1; and by virtue of the yielding lost motion connection constituted by the spring H5, slot I20 and pin I2I the shaft I I8 cannot, upon turning of the shaft to increase speed-as at starting of governor operationbe moved so forcibly as to strain or break the arms H2, H4 or H1. The danger of such breakage occurring arises-from the fact that, until operating fluid pressure is built up in the hydraulic system by the gear pump or otherwise, the power head piston is oillocked against downward movement.

To enable the relationship between turning of the shaft I I8 and adjustment of the speeder lever to be changed, a slot I24 (Fig. 1) is provided in the upstanding arm H4 of the bell crank I I0, and the pin I2I can be locked in various positions along the arm I I4 thus changing the angle through which the bell crank (and consequently the lever 80) will swing with a. given angular movement of the adjusting shaft H8. The pin I2| has a clamping nut I2|a which is readily accessible through the top of the speedercase.

Booster servo Shown at the left in Fig. 3 and located at the left in Fig. 2 is a cylinder block portion 240 of the speeder case portion which contains the power head etc. previously described. Fig. 1, at the left, also shows part of the fluid duct system associated with the mechanism about to be described. The booster-servo is for enabling air pressure from the starting air line of a Diesel engine to be used to insure the building up of adequate pressure and supply of operating fluid in the governor during the operation of starting the engine, or previously.

- As shown in Fig. 3 the block portion 240 of the speeder case (hereinafter for convenience block 240) is bored upwardly from the bottom at 24I to a point near the top to receive a piston 242 having an imperforate partition 243 between its ends; a downwardly projecting hollow cylinder portion 244 below the partition, and an upwardly projecting hollow cylinder portion 245 above the partition. The piston 242 is normally forced downwardly, by a strong spring 246 in the upper part of the cylinder bore 24I, against a pluglike member 241 fixed to the block 240 and which nearly closes the lower end of the cylinder bore. The member 241 l. .s an axial bore 250 leadin therethrough and having an enlarged entrance portion threaded to receive an air pipe connector fitting (not shown) of the starting air line. Pressure in such lines is usually several hundred pounds. An upper cylindrical portion of the pluglike member 241 constitutes a fixed piston mating with the lower cylinder portion 244 of the piston 242. A cup shaped flexible sealing element 252 is secured to the fixed piston 241, so that air admitted through the bore 250 thereof will raise the hollow piston 242, compressing the spring 246.

Assuming the upper part of the cylinder bore 24I contains hydraulic fluid, the air line pressure will force such fluid out of the upper end of the block 240 through a duct 253 formed by intercepting bores in the top wall of the block 240 as clearly shown. The duct 253 (of. Figs. 1, 2 and 3) leads to the constant pressure space I1 etc. of the hydraulic system of the governor as through a vertical bore 254 (see Fig. 1) and check valve chamber 255part of bore I02which latter communicates with the duct comprised of bores I00 and I M (Fig. 1) already described. The check valve chamber 255 has a spring pressed ball 251 therein operative to prevent loss of pressure from the constant pressure chambers (I1 etc., including power head cylinder 92) of the governor after starting has been accomplished.

The booster-servo obtains hydraulic fluid from the speeder case portion of the sump through a duct comprising interconnected bores in the speeder case; 260', 26I, 262 and 263 (Fig. 2 particularly), past a gravity seated ball check 264 (Fig. 1) in the bore 262. The bore 263 intercepts the discharge duct 253 in the top of the booster cylinder block. The ball check 264 prevents return flow of fluid to the sump from the booster cylinder when the booster-servo piston is raised in starting.

In the event the governor stands idle for some time the spring loaded pressure accumulators will ordinarily force most of the fluid out of the constant pressure spaces into the sump. In such event subsequent operation of the booster-servo piston would be resisted only by the unloaded or nearly unloaded accumulator springs. Also if fluid happened to be low in the speeder case portion of the sump at the time the booster-servo piston 242 previously descended to draw a new supply of fluid from that portion of the sump and the sump supply failed to supply fluid there would be nothing but air in the upper part of the cylinder 2 to damp the upward movement of the booster-servo piston on the next actuation. In either event damage to the upper boosterservo cylinder head portions can be prevented by the present arrangement (Fig. 3), viz:

The upper cylinder portion 245 of the boosterservo piston slidably receives a dash pot plunger 265 having a small hole 268 extending therethrough to a downwardly open counterbore 261 of the Plunger. A compression spring 268 resting on the partition 243 extends into the counterbore 261 and operates, whenever necessary, to draw fluid into the chamber below the plunger through the hole 256 until the spring has become fully extended. The hole 266 of the plunger is aligned with the vertical portion of the duct 253 so that the hole 266 cannot be sealed by engagement of the plunger with the top of the cylinder bore 24I. A cross slot in the top of the plunger 265 prevents the plunger from blocking exit of hydraulic fluid from the booster-servo cylinder 2 to the duct 253 at the completion of the upward stroke of the booster-servo piston. .In the fully expanded position of the spring the plunger 2'65 stands a short distance above the top rim.

of the upper cylinder portion 245 of the boosterservo piston. Thus when air is applied to raise the booster-servo piston and the piston encounters little or no resistance except that afiorded by the pring 246 the impact of the booster-servo piston is cushioned by discharge of hydraulic fluid from the dash pot.

To prevent oil from entering the air starter line where it might cause an explosion if allowed to be carried into the engine along with the starting air, a vent hole is provided at 210 in the member 241 which serves as 'the fixed air piston. The illustrated position of the vent also prevents air which may leak past the sealingcup 252 from entering the hydraulic fluid of the governor along the outside of the hollow piston 242.

Starting air admitted to the chamber between the fixed and movable pistons 24'! and 242 can be bled out of said chamber at a ball check valve 212, Fig. 3, having a ball 213 which moves outwardly against a seat 214 in a sleeve 215 (overcoming the force of the ball spring 216) when air is applied to the line and which is pushed away from the seat by the spring when the air pressure finally drops say to around 75# per sq. in.

While the booster-servo mechanism is described above as operated by the starting air line of a Diesel engine and the governor mechanism is shown a adapted for speed governing of such engine, it will be understood that the boosterservo mechanism may be operated by any kind of fi'lld pressure and that the governor, by appropriate adaptation as Well known in the art, can be used for other purposes than speed regulation and control.

I claim:

1. In a speed governor wherein a weighing element drivingly connected to a rotary part of a mechanism to be governed controls regulation of such mechanism through a hydraulic relay, means operable by such rotary part to maintain a supply of hydraulic fluid under operating pressure during operation of the governor, said means including a reservoir 'for the fluid, a hydraulic booster piston and cylinder in upright position, the top of the cylinder having hydraulic fluid connections with said reservoir and said piston having a spring to force it downwardly in the cylinder capable of drawing a booster reserve supply therefrom and maintaining the reserve supply separate from the reservoir, and a motor operable by elastic fluid associated with the lower end of the booster piston and operable to cause said piston to rise in its cylinder and pump hydraulic fluid of the reserve supply to the reservoir for creating initial pressure upon tarting of the governor operation.

2. In argovernor for engines adapted to be started by compressed air, said governor employing a hydraulic fluid operated regulation sys tem, a casing for the governor providing a nor mal supply for hydraulic fluid, a substantially upright booster servo cylinder bore in the casing, a duct formed in the casing leading into an upper end portion of the cylinder bore and communieating with said normal fluid supply to charge the cylinder bore with hydraulic fluid from the system for subsequent redelivery to the system through said duct, a booster servo-piston in the cylinder bore, a spring acting downwardly on the piston to cause the piston normally to occupy a lower end portion of the bore when the cylinder bore is charged, an air cylinder bore extending upwardly in the piston from the lower end of the piston, a fixed plug element in the lower end of the cylinder member and having a piston portion slidably fitting the air cylinder bore, a duct in the piston portion of the plug element lengthwise thereof to supply air as from an enginestarting air supply to the air cylinder bore of the booster servo-piston for actuating the latter during starting of such engine, and a vent in one of said elements communicating with the lower end of the booster servo-cylinder for preventing intercharge of hydraulic fluid and air past the main cylinder surface and the air cylinder surface.

3. In a governor, weighing means responsive to a force factor of a mechanism orapparatus to be governed, a source of hydraulic pressure dependent upon sustained operation of the mechanism or apparatus to be governed, hydraulically-actuated regulating means for said mechanism or apparatus, a pilot valve operatively connected to said weighing means for controlling the supply of hydraulic fluid from said source to said regulating means, a casing, a bi-directional hydraulic motor mechanism in said casing operatively connected -to and constituting an adjusting means for said weighing means and supplied with fluid from said source, and means for supplying said weighing-means-adjusting hydraulic motor mechanism with operating hydraulc fluid during incipient as well as sustained operation of the mechanism or apparatus to be governed, said last-mentioned means comprising a hydraulicpressure boosting mechanism in said casing alongside said hydraulic motor mechanism and operative, in response to a starting condition of said mechanism or apparatus, to boost the hydraulic pressure derived from said source and delivered to said motor mechanism to a value suflicient to operate said motor mechanism at the inception of operation of said mechanism or apparatus to be governed. Y

ALBERT KALIN.

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