US1814630A - Governor - Google Patents

Description

Jul 14, 1931. I J, 5, MYERS 1,814,630

GOVERNOR Fil y 1 1925 4 Sheets- Sheet 1 I 15." uers WITNESS INVENTOR ATTORNEY J. S. MYERS July 14, 1931.

GOVERNOR Fi led July 15, 1925 4 Sheets-Sheet 2 .JZSNqers WITNESS ATTORNEY July 14, 1931. J. s; MYERS GOVERNOR Filed July 15, 1925 4 Sheets-Sheet s .15. N qers INVENTOR WITNESS 7 7 ATTORNEY July ;4, 1931.

J. S.I.MYERS GOVERNOR Filed July 15,1925 4 Sheets-Sheet 4 .75. Mqers WITNESS ATTORN EY Patented July 14, 1931 UNITED STATES" PATENT OFFICE JOHN S. MYERS, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION PENNSYLV'ANIA GOVERNOR Application filed July 15,

' ratus of the character designated which shall be extremely sensitive to variations in speed of the prime moverand which shall effect a positive control of said speed.

A further object of my invention is to provide means associated with a governor operated by variable fluid pressure developed by a pump, for obtaining further and wider variations in pressure varying with the velocity of the fluid under pressure delivered by the pump.-

lhcse and other objects are obtained by apparatus made in'accordance with my invention and illustrated in the accompanying drawings wherein Fig. 1 is a View in elevation of an elastic fluid turbine having my improved governing apparatus applied thereto; Fig. 2 is a sectionalview of the pump and governing apparatus shown in Fig. 1; Fig. 3 is a View similar to Fig.2 but showing a modified form of my inventionemploying a different kind of pump from that shown in Fig.1; and Fig. 4 is a sectional view of a form of viscosity compensating mechanism adapted to be employed with my invention.

It has heretofore been proposed to govern a prime mover by variable fluid pressure operated governing apparatus, the variable fluid pressure being developed by a pump driven by the prime mover. such apparatus may be found in my Patent No. 1,533,888, issuedApril 14, 1925,and assigned to the \Vestinghouse .Electric and Manufacturing Company. In the apparatus described in the aforesaid patent, governing movements are effected by fluid pressure developed by a centrifugal pump driven by the prime mover and varying as the square of the speed thereof. l/Vhile such apparatus has proved to be eminently successful in operation, I have found that by the addition of a simple apparatus to the system, a far wider variation in pressure may be securedthan the variation in pressure developed by the pump alone and, as a result, the governing An example of 1925. Serial No. 43,811.

apparatus is simplified and made more sensitive to varlatlons 1n speed.

In accordance with my invention I may employ either a centrifugal pump, as shown in my patent'aforesaid, or I may employ a pump having purely a volume displacement characteristic, said volume displacement varying with the speed, such, for example, as a gear pump, and inter-pose a suitable'valve or orifice in the path of the fluid discharged from the pump, whereby it may be caused to develop a pressure varying withthe speed of the prime mover. WVith whatever type of pump employed, the major portion of the flowing through the converging-divergmg passage.

As the velocity of the fluid flowing through the converging-diverging passage increases,

its pressure decreases at the converged portion. Upon decreases in pressure developer by the pump, creases, the velocity of fluid flowing through the conve'rging-diverging passage decreases, and the pressure at the converged portio n of the passage increases. I therefore provide a governing apparatus which utilizes the volume of fluid pumped deboth of the 'beforementioned variable. pressures; employing the pressure which increases with a speed increase on one side of an operating piston, and the pressure which decreases with aspeed increase on the opposite side ofan operating piston. In the resultingapparatus, the effective change of pressure for a given change in speed is much greater than any heretofore known to me and the apparatus is therefore more sensitive and more effective in providing close regulation of the machine governed.

Referring now to the drawings for a better understanding of my invention I show in Fig. 1 at 10 an elastic fluid turbine having the volumeof fluid an admission valve 11 controlled by my improved fluid pressure governing apparatus at .12. Fluid pressure for operating the governing apparatus 12 is developed by a pump 13, driven directly from the turbine shaft and delivering relatively high pressure fluid to the governing apparatus at 12 through a con-duit 14. The inlet of the pump 13 is indicated at 17 and fluid passing to the inlet enters through a conduit 18. While a portion of the fluid under pressure developed by the pump 13 is piped directly from the discharge side of the pump to the governing apparatus at 12, the major portion of the fluid under pressure developed thereby is delivered to a fluid reservoir 19 through a conduit 21 in a manner to be more fully described later.

Referring now to Fig. 2 it may be seen that fluid discharged by the pump 13 into the conduit 21 passes through a converging-diverging passage or Yenturi nozzle 22. The fluid passing the converged portion of the passage 22 hasits velocity increased beyond the velocity of the fluid discharged by the pump, and the pressure thereat is consequently less than that eitherat the entrance or at the discharge side of the passage. Upon an increase in speed of the turbine 10, the pressure developed by the pump 13 increases as well as passing through the conduit 21. The volume passing through the conduit 21 increasing, efiects an increase in velocity at the converged portion of the pas sage 22 and the pressure thereat decreases. n my improved apparatus, therefore, the pressure delivered by the pump 13 and piped to the governing apparatus 12 through the conduit 14 increases upon increases in speed and decreases upon decreases in speed. At the same time, the pressure of the fluid in the converged portion of the passage 22 decreases upon increases in speed and increases upon decreases in speed. I accordingly provide a conduit 23 communicating ivith the converged portion of the passage 22 and leading to the governing apparatus 12 for operation thereof in a manner to be more particularly described later. I

In order to provide a dependable rate of change in pressure in the converged portion of the passage 22 per unit of change in speed of the primermover governed, it isdesirable that the pressure at the discharge side of the passage 22 be maintained substantially constant.- I have accordingly provided at the lower end of the conduit 21, within the reservoir 19, a relief valve 24 designed to keep said pressure substantially constant. The relief valve 24 has connected thereto a pistonmember 26'subjected, on its under side, to the pressure within the conduit 21 tending to force-v it upwardly and to force the valve 24 inan opening direction. Opposing the pressure acting against the piston member 26 is a Weight 27 carried by a lever 28. The lever 28 is pivoted at 29 and bears uppn the piston member 26 through a stem 31 abutting the IGVBIQS at a point between the weight 27 and the pivot 29. Should the pressure within the conduit 21 and at the discharge side of the passage 22 increase, the piston 26 is forced upwardly and the valve 24 opened wider, relieving the increased pressure. Should the pressure Within the conduit 21 tend to decrease, the Weight 27 causes the piston 26 to move the valve 24 in a closing direction, restricting the flow of fluid through the valve 24 and perlnitting the pressure Within the conduit to build up. In order that the pressure Within the conduit 21 may be regulated, I provide means for shifting the weight 27 along the lever 28 in the form. of-a rod 32 coupled to a bell crank lever 33 which is pivoted at 34 and which is operated through a stem 36, by a screw and nut connection 37. Upon rotating the stem 36, the bell crank lever arm connected thereto is raised or low ered and the weight 27 is'moved inwardly or outwardly along the lever 28, varying the force exerted upon the piston 26 by the weight 27. The stem 36 may be rotated by any suitable means such, for example, as a. hand wheel 38 which affords a ready means for moving the weight 27 along the lever 28 remotely from the weight 27, or by any other means known to the art. Inasmuch as vari ations in pressure in the conduit 21 vary the pressure at the converged portion of the passage 22, shifting the position of the Weight 27 effects a variation in the speed of the turbine 10.

Fluid flowing through the conduit 21 is utilized to operate an. ejector 41- having an inlet 42 and a discharge conduit 43. Fluid discharged through the conduit 43 preferably passes through an oil cooler 44 and from thence to a conduit 46. It will be apparent that the pressure developed by the ejector 41 and passing through the conduit 46 is below that of the pressure developed by the pump 13 and is such as to be desirable to employ in the lubrication of bearings. I accordingly show a conduit 48 leading from the conduit 46 to a bearing 49. After passing through the bearing 49 fluid is drained away therefrom through a conduit 51 and a branch conduit 52 back to the reservoir 19 (see Fig. 1). A portion of the fluid under pressure developed by the.ejector 41 is conveyed to the inlet 17 of the pump 13 through the conduit 18 which is connected to the conduit 46. In 0 asmuch as the pressure developed by the pump is the pressure delivered thereto at its inlet side plus the pressure due to its speed, it is highly desirable that a constant pressure be provided at the inlet side of a pump employed for developing governing pressure in order that said pressure may truly be a function of the speed of the prime mover. I accordingly provide a by-pass valve 54 in the conduit 46 which prevents a building up of pressure in the conduit 18 beyond a predetermined pressure. The by-pass valve 54 is biased towards its seat by a spring 56 of the desired tension. Should the pressure within the conduit 46 rise above the pressure determined by the load on the spring 56, the valve 54 is opened and fluid is by-passed thereby tl'n-ough a conduit 57 back to the reservoir 19.

The governing apparatus 12 embodies an operating cylinder 61 having disposed there'- in a piston 62 connected directly to the admission valve 11. through a stem 63. The piston 62 is biased downwardly, in a direction for I closing the valve 11, by a spring 64. On

the upper side of the piston 62 is a stem portion 66 of relatively large diameter which makes an approximately fluid-tight fit with the upper cover 67 of the cylinder 61. The purpose of the upper stem portion 66 of the piston 62 is to limit the area of the upper side of said piston and make it less than the area of the under side. Fluid under pressure developed by the'pump 13 is delivered through'the conduit 14 to the upper side of the piston 62 and, in addition to the force exerted by the spring 64, tends to force the piston downwardly and to force the valve 11 in a closing direction. Fluid under a pressure varying inversely with the velocity of the fluid flowing through the passage 22 is conveyed through the conduit 23 to the lower side of the piston 62 and acts upon the greater area of said piston, tending to force it upwardly against the force of the higher pressure acting on the upper side of said piston plus the force exerted by the spring 64. The initial deflection of the spring 64 may be varied by means of an adjusting screw 68 extending through the upper part of the governor and'connected to an abutment 69 bearing against the spring 64. Fluid leaking past the stem portion 66 of the piston 62- is free to pass to the reservoir 19 through a drain conduit 71. Fluid leaking by the stem 63 in the lower part of the cylinder 61 passes through a conduit 72'to the conduit 71 and thence to the fluid reservoir 19.

The operation of the apparatus so far described is as follows: Assume that the turbine 10 is running under normal load and at normal speed. The fluid under pressure developed by the pump 13 is conveyed to the upper side, or the side of lesser area, of the piston 62 and, in addition to the force of the spring 64, tends to force the piston downwardly. At the same time, fluid under a lesser pressure flowing through the converged portion. of the passage 22 is conveyed to the lower side of the piston 62 through the conduit 23 and bearing against the greater area of said piston tends to force the piston upwardly. Under the conditions assumed, under normal load and running at normal speed, the opposing forces acting on the piston 62 are equal and pressure -'duit 76, therefore,

the piston 62 remains stationary. Assume now'that there is an increase in speed of the turbine 10, increasing the fluid pressure developed by the pump 13 as well as increasing the volume of fluid flowing through the passage 22. The pressure in the converged portion of the passage 22 and acting against the lower side of the piston 62 decreases while the pressure developed by the pump increases in proportion to the square of its speed. The piston'62 is therefore promptly moved downwardly, imparting a closing movement to the admission valve 11. The piston 62 continues to move downwardlyuntil the load on the spring 64 has decreased sufliciently so that the lesser pressure acting against the lower side of the piston can balance the force exerted by the greater pressure plus the force exerted by the spring 64 against the upper side of the piston or side of lesser area.

Assume now that there is a decrease in the speed of the turbine 10. The pressure developed by the pump 13 decreases as well as the volume delivered thereby. \Vith a decrease in pressure and a decrease in volume, the pres Inasmuch as the force of the spring 64 is exerted to move the piston 62 in a direction for closing the admission valve 11, it -will be obvious that upon the admission valve closed. This will also occur upon shutting down the turbine 10. In order to start the turbine after being idle, it is necessary to introduce fluid under pressure into the system from an outside source. I accordingly show at 76 a conduit adapted for connection with fluid under pressure from some outside source, not shown, and connected to the conduit 21. A check valve 7 7 is provided in the conduit 76 which prevents aback flow of fluid from the conduit 21 When the pump 13 is in operation and developing fluid pressure. I further provide a check valve 78 within the ejector intake 42 which prevents an outflow of fluid from the conduit 21 when fluid is being admitted from an outsidesource. A si1nilar check valve 79 is provided at the inlet of the pump 13 to prevent an escape of fluid from the pump when fluid is being admitted to the system through the conduit 76. When pressure is being admitted to the coniti is free to build up pressure quickly within the conduit 21 and the conduits 23 and 14. As the pressures within-the conduits 23 and 14 are, under the circumstances described, equal, the pressure within the conduit 23 acting against the a failure of governing fluid 11 will be greater area of the piston 62 forces said pis ton upwardly and opens the admission valve 11, permitting the turbine to be started.

In order that the bearings may be lubri- 5 cated when starting the turbine and introducing fluid under pressure from an outside source, I provide a passage 80 in the relief valve 24 which permits a restricted flow of fluid into the Conduit 43 and from thence to the hearings in a manner already described.

Referring now to Fig. 3 I show a modifled form of my invention employing a gear pump which has the characteristic of displacing a variable volume of fluid in accordance with the speed of the prime'mover instead will'vary directly with the speed. In the drawing a pump is "shown at 81, such as illustrated and described in my copending application Patent No. 1,654,048, issued December 27, 1927, on an application which was copending herewith, and assigned to the Nestinghouse Electric and Manufacturing Company, and has an intake 82 and a discharge conduit 83. Inserted within the discharge conduit 83 is a converging-diverging nozzle which, when used in connection with'a gear pump, I prefer shall be of the compound variety comprising an outer convergingdiverging nozzle 84 and one or more inner converglng-diverglng nozzles, illustrated as two, 85 and 86. The purpose of compounding the converging-diverging passage is to secure a wider variation in pressure per unit of change in the velocity of the fluid passing therethrough than can be obtained with a 40 single orifice. The orifices or converged portions of the nozzles 84, 85 and 86 aflord sufficient resistance to the flow of, fluid delivered by the pump 81 to cause it to develop at its discharge side a pressure varying with the speed. The conduit 14 leading to the governor 12 and conveying the higher pressure is connected directly to the delivery passage 83,

while the conduit 23 conveying the lower pressure is connected to the throat or converged portion of the inner nozzle 86.

Connected to the throat of the nozzle 84 is a conduit 87 which maybe connected to the reservoir 19 (Fig. 2), whereby a greater quantity of fluid may be entrained from the reservoir and discharged at a lower pressure for use in the turbine bearings.

When starting the turbine 10, the fluid, usually lubricating oil, pumped by the pump 81 is liable to be cooler than when the turbine has been run for a considerable time, having a greater viscosity, and the resistance to flow through the nozzles 84, 85 and 86 willtherefore be greater. With a greater resistance to flow through the nozzles, the pressure at the discharge side of the pump for a given speed a uniform temperature and viscosity. I accordingly provide means responsive to the temperature of the fluid and consequently responsive to its viscosity for by-passing a part of the fluid delivered to the conduit 83 and V maintaining the fluid pressure delivered to the conduit 14- a true function of the speed of the turbine. The apparatus comprises an adjustable valve member 91 carried by a lever 92 which is pivoted at 93. The lever 92 is controlled by a thermostat 94- which is comprised of a series of alternating strips of metal 96 and 97, for example, brass and steel, having different coeflicients of expansion. A passage 98 leads from the discharge conduit 83 to the valve member 91 and fluid passing by said valve member 91 flows around the members 96 and 97 and. out at the top of the thermostat 94 through a conduit 99 into the discharge side of the converging-diverging passage. ranged that as the temperature of the fluid decreases, the valve 91 is raised, permitting a freer flow of fluid thereby and lowering the pressure in the conduit 83.

Uponan increase in temperature of the fluid, the lever 92 is lowered and the valve 91 is moved in a closing direction, restricting the flow'of fluid by the valve 91. In order that the rate of opening of the valve 91 per unit of change in temperature of the fluid may be varied, I provide a movable support 101 for the pivot 93 and provide an adjust- I ing screw 102 for moving said pivot longitudinally of the lever 92. Should the pivot 93 be moved inwardly of the thermostat 94 it is apparent that the rate of opening of the The members 96 and 97 areso ar- 93 be moved outwardly of the thermostat 94 the rate of opening of the valve 91 will be lessened.

The operation of this modification of my invention is as follows: Fluid from the fluid reservoir 19 supplied to the inlet of the pump 81 is pumped therethrough in a volume directly proportional to the speed of the turbine into the discharge conduit 83. The resistance to-flow within the discharge conduit causes pressure to build up at the delivery side of the pump varying directly with the speed of the turbine. At the same time, the thermostat 94 operates through the valve 91 and compensates for any changes in viscosity of the fluid and renders the pressure within the conduit 14 a truefunction ofthe speed of the pump 81. The major portion of the fluid delivered by the pump 81 passes through the nozzles 84, 85 and 86, having its pressure reduced in the throat portions thereof, said pressure varying inversely to the speed of the prime mover.' The conduit 23, leading to the governor 12, as shown in Fig. 2, connects directly with the converged portion of the nozzle 86 and serves to aid in the operation of the governor 12in a manner already described.

Where a centrifugal pump is employed with my invention, difliculties due to varying viscosity of the fluid employed are not so evident as where a gear pump is employed.-

Conditions may arise, however, where the varying viscosity of the fluid passing through the converging-diverging passage employed in the system will render erratic the pressure of fluid in the throat portion of passage. I accordingly show in Figs. 2 and 4 further apparatus designed to compensate for variations in the viscosity of the flu'id,-which may be used with equal effectiveness with a gear pump or a centrifugal pump. In these figures of the drawings, a converging-diverging nozzle 106 is shown having a converged or throatportion 107 Within the nozzle member 106 and extending longitudinally thereof I provide an adjusting member 108, said member being carried in suitable guides 10%) and 111 located at opposite ends of the nozzle 106. The adjusting member 108 is provided, intermediate its ends and adjacent the throat 107, with an en-v larged portion 112 substantially conforming in contour to the throat passage 107. One end of the compensating member 108 is connectedto a lever 113 which is operated by a thermostat 114 in the same manner as already explained for the thermostat 94. Fluid from the discharge side of the pump with which the nozzle 106 is associated is conveyed to the thermostat 114 through conduits 14 and 116 and passes outwardly thereof through a passage 117. The opposite endofn.

the compensating member 108 is provide with a spring 118 for biasing it inwardly of the nozzle member 106 and taking up slack in the thermostatic connections. In order to change the initial adjustment of the compensating member 108 it may be connected to the lever 113 by a screw and nut connection 119 and have the associated end of the member 108 squared as shown at 120 to fit a socket 121 having a stem extending outwardly of the thermostat 114 andoperable by means of ahand wheel 122. By rotating the hand wheel 122 the member 108 is turned in the screw and nut connection 119 and the enlarged portion 112 is moved inwardly or outwardly, as the case may be, of the throat portion 107. At 123 I show a drain conduit for. carrying away leakage by the adjusting mechanism.

The operation of this modification of my invention will be apparent. Fluid enters and passes through the nozzle member 106 in the direction shown by the arrows. When the fluid is relatively cool, the thermostat 114 is so connected that the enlarged portion 112 of the compensating member 108 is moved away from the throat portion 107, permit ting a freer flow of fluid therethrough. As

claims.

portion 112 toward the throat portion'107,

restricting the flow of fluid therethrough.

From the foregoing it will be apparent that I. have provided an improved governing apparatus extremely sensitive in operation and capable of effecting close control of the prime mover governed.

While I have shown my invention in but two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended What I claim is:

1. The combination with a prime mover, of a pump driven thereby for developing a fluid pressure varying with the speed thereof, a fluid reservoir, a discharge conduit.

leading from the pump to the fluid reservoir, a converging-diverging passage within the discharge conduit, a biased relief valve for maintaining a substantially constant pressure at the discharge side of the convergingdiverging passage, an ejector operated by fluid pressure passing the relief valve for supplying fluid under pressure to the inlet side of the pump, means for-maintaining the pressure supplied to the inlet side of the pump substantially constant, a fluid pressure operated governor including a biased element movable in response to variations in fluid pressure, means for subjecting one side of said element to the pressure delivered by the pump, and means for subjecting the other side of said element to the variable pressure in the converged portion of the passage.

2. In a fluid pressure operated governing apparatus for controlling the speed of a prime mover having a pump driven thereby for developing a fluid pressure varying as a function of only the speed thereof, the combination of an operating piston having a side of lesser and of greater area, a spring for biasing the piston in the direction of its side of greater area, conduit means leading from. the pump discharge to the side of lesser area, a converging-diverging passage provided in said conduit and other conduit means leading from the converged portion of the passage to the side of greater area.

3. The combination with a prime mover having an admission valve, of a pump driven by the prime mover for developing fluid pressure varying with the speed thereof, a

discharge conduit for the fluid under pres sion valve, a spring for biasing the difleri ,ential piston in a direction for closing the admission valve and in the direction of the side of greater area of said piston, conduit means leading from the pump discharge to the side of lesser area of the differential piston, 'and other conduit means leading from the converged portion of the passage to the side of greater area. i

4. The combination with a prime mover having an admission valve, of a pump driven by the prime mover for developing fluid pressure varying with the speed thereof, a discharge conduit for the fluid under pressure developed by the pump, said conduit having a converging-diverging passage provided therein, a fluid pressure operated governor for controlling the admission Valve and ac tuated by the resultant force exerted by the pressure of fluid developed by the pump opposed by force exerted by the pressure of fluid in the converged portion of the passage, a valve member for modifying the rate of flow through the passage, and means responsive to the temperature interposed in the path of the fluid discharged from the pump for actuating the valve member.

5. The combination with a prime mover having an admission valve, of a pump driven by the prime mover for developing fluid pressure varying with the speed thereof, a discharge conduit for the fluid under pressure developed by the pump, said conduit having a converging-diverging passage provided therein, a fluid pressure operated governor for controlling the admission valve and actuated by the resultant of force exerted by pressure of fluid developed by the pump opposed by force'exerted by the pressure of fluid in the converged portion of the passage, temperature responsive means disposed within the path of the fluid under pressure .developed by the pump, and means actuated by said temperature responsive means for varying the area of the converged portion of the passage.

6. The combination of a primernover having an admission valve, a pump driven by the prime mover for developing fluid pressure varying with the speed thereof, a discharge conduit for the fluid under pressure developed by the pump, said conduit having a converging-diverging passage provided therein, a fluid pressure operated governor for controlling the admission valve and actuated by the resultant of force exerted by pressure of fluid developed by the pump opposed by force exerted by pressure-of fluid in the converged portion of the passage, temperature responsive means disposed within the path of the fluid under pressure developed by the pump, a diverging-converging member disposed Within the converging-diverging passage, and an operative connection be tween the temperature responsive means and the diverging-converging member.

7. The combination of a prime mover having an admission valve, apump driven by the prime mover for developing fluid pressure varying with the speed thereof, a discharge conduit for the fluid under pressure developed bythe pump, said conduit having a converging-diverging therein, a governor for controlling the admission valve and operated by the diflerential of forces exerted by fluid pressure developed by the pump opposed by pressure of fluid in the converged portion of the paspassage' provided sage, temperature responsive means disposed operated governor having an element actu-' ated by the diiferentialof forces exerted by pressure of fluid developed by the pump opposed by pressure of fluid in the converged portion of the passage, a relief valve for controlling the pressure at the discharge side of the passage, a lever bearing upon the relief valve, a sliding Weightprovided on the lever for varying the force exerted thereby, and means remote from the Weight for varying the position thereof on the lever.

9. The combination with a prime mover having an admission valve, of a speed governing mechanism for controlling the speed of the prime mover comprising a piston connected to and directly actuating the admission valve, a spring biasing the piston and admission valve in valve-closing direction, a pump driven by the prime mover and providing a fluid pressure varying substantially only as the square of the speed of the prime mover,

conduit means for conve ing said fluid pres-. sure to said piston, said u1d pressure biasing the piston in valveclosing direction, a convergang-dlverging passage therein COIHIIlIlIlleating with said pump, and means for apply-' ing the fluid pressure obtaining at the throat of said converging-diverging passage to the piston in valve-opening direction; the varia'tions in the last-mentioned fluid pressure cooperating with the variations in the first-' mentioned fluid pressure to provide increased variation in deflection of the spring upon variation in speed.

10. In a governor for governing the speed of a prime mover having an admission valve,

, the combination of means developing a fluid pressure varying as the square of the speed of the prime mover, means providing a see ond fluid pressure varying inversely with the speed of the prime n1over,'valve operating mechanism forthe admission valve including a pressure responsive element and a spring biasing the element, said mechanism operat ing upon change in spring deflect-ion to provide a valvemovement proportional to the change in spring deflection, means for applying the first fluid pressure to the pressure rcsponsive element in valve closing direction, and means for applying the second fluid pressure to said element in opposition to the first fluid pressure so that the variations in the second fluid pressure assist the variations in the first fluid pressure to provide increased spring deflection and consequent increased valve movement.

11. In a governor for governing the speed of a prime mover having an admission valve, the combination of means for developing fluid pressure varying as a function of the speed of the prime mover, means responsive to said fluid pressure for providing a second fluid pressure varying inversely with the first fluid pressure, valve operating mechanism for the admission valve including a pressure responsive element and a spring biasing the element, said mechanism operating upon change in spring deflection to provide a valve movement proportional tothe change in spring deflection, means for applying the first fluid pressure to the pressure responsive element in valve closing direction, and means for applying the second fluid presfluid pressure so that the yariations in the second fluid pressure asslst the variations in the first ,fluid pressure to provide increased spring deflection and consequent increased valve movement.

12. In a regulating mechanism for providing a regulation in response to a variable governing force, the combination ofa movable element subjected to the governing force, a spring acting on said element, the deflection of said spring being changed upon change in the overning force, means for applying a thir force to said element, and means for providing, upon Variation in the governing force, a variation inthe third force which assists said variation in governing force to provide a change in deflection of said sprlng which is greater in proportion to the total' spring deflection than the change in governing force is to the total governing force, and

means controlled by said element for providing the regulation.

In testimony whereof, I have hereunto subscribed my name this eighth day of July,

JOHN s. MYERS.

sure to said element in opposition-tothe first

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