US561520A

US561520A - Speed-modifying apparatus

Info

Publication number: US561520A
Authority: US
Publication date: 1896-06-02
Anticipated expiration: 1913-06-02

Description

(No Model.) 2 Sheets-Sheet 1. 1:'. H. RICHARDS. SPEED MODIFYING APPARATUS'.

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F. H. RICHARDS. vSPEED MQDIPYING APPARATUS. No. 561,520. Patented June 2, 1896.

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FRANCIS il. RICHARDS, OF HARTFORD, CONNECTICUT.

SPEED-MODIFYING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 561,520, dated June 2, 1896.

Application filed November Z1, 1895. Serial No. 569,626. (No model.)

To all whom it may concern:

Be it known that I, FRANCIS H. RICHARDS, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Speed-Modifying Apparatus, of which the following is a specification.

My invention relates to speed modifying or governing apparatus, the object being to provide a thoroughly-efficient apparatus of this character which is readily applicable to various forms of machines and mechanisms where a modification or variation in speed at successive or predetermined points in the operation thereof is an essential.

In the drawings accompanying and forming part of this application, Figure l is a central transverse section, taken in line 2 2, Fig. 2, of a speed modifying' or governing apparatus embodying the present improvements and illustrating in full lines a part of the main or power roll of a machine operatively connected with the apparatus, and showing also the positions assumed by the operative parts of the apparatus when the machine controlled thereby is running at its maximum speed. Fig. 2 is a front elevation of the apparatus with the face or frontplate removed and with portions broken away to more clearly illustrate the operative parts thereof. Fig. 31's an elevation, partly in section, of aportion of the apparatus, showing the positions assumed by the operative parts thereof when the speed of the machine controlled thereby has been slackened or reduced. Fig. 4 is a View similar to Fig. 3, illustrating the positions occupied by the operative parts of the apparatus when the machine controlled thereby has been stopped. Figs. 5 and 6 are detail views illustrating a valve casing or cylinder formone form of fluid-regulating valve.

ing part of. the apparatus illustrated by Fig. l.- Figs. 7 and S are detail views illustrating Fig. i) is a front elevation, partly in section, illustrating one modification of the invention. Fig. l0 is a front elevation thereof. Fig. ll illustrates in plan the valve operatin g or actuating mechanism shown by the modification, Figs. fl and l0. Figs. l2 and 13 are detail views of one modification of a fluid-regulating valve, andu Fig. l-fi is an elevation of the apparatus operatively connected with a motor or other driving `mechanism and with the main or powerroll of a machine.

Similar characters refer to like parts in all the figures of the drawings.

The speedmodifying apparatus herein shown and described is readily applicable to various forms of machines or mechanisms which require at any point or points in the operation thereof a variable speed or inovement. One instance of the practical application of my present improvements is disclosed in an application for patent for a weighing-machine liled simultaneously herewith. This weighing-machine embodies as an improvement thereof a variable-speed force-feeder4` power roll of some machine for example,

the main roll of a feeder or feeding apparatus for a Weighing-machine, such as is shown by my application hereinbefore referred toor said roll M itself may constitute the feeder or feeding device.

In the application of the speed-modifying apparatus herein shown and described to a feeder or feeding device of a weighing-machine it is possible to secure by a minimum expenditure of power a progressively decreasing speed of the feeder movement at predetermined pointsin the descent of the bucket, whereby a stream, at first of relatively large and then of progressively decreasing volume, may be fed or forced from the supply-chute, which contains the material to be weighed, into the bucket, this variation in speed in that art workingaveryimportant result.

The main roll M is shown supported by a hollow shaft 2, the peculiarfunction of which will be hereinafter described, the roll M being secured to said shaft 2 in some suitable manner for rotative movement therewith. The shaft 2 is illustrated carrying at the outer end or extremity thereof the speed modifying or governing apparatus, which is IOO designated in a general way by S and which, as shown, is adapted for rotative movement about the hollow supporting-shaft 2.

A shell or casing is illustrated at C and is shown consisting of the rear wall 3, and the annular wall it, joined thereto, and the removable front wall or face-plate 5, these forming an interior chamber or compartment for containing the operative parts and controlling devices of the speed-modifying apparatus.

The apparatus embodies two operativelyconnected members and variablepressure means acting against one of said members. In the form shown these driven and driving members consist of a pair of closely-meshing pinions (5 and 7, which are supported for rotative movement within the shell or casing 3 of the apparatus, the first-mentioned pinion constituting the driven pinion and the other the driving-pinion, and the driven pinion 0 will be carried bythe supporting-shaft 2, being ixedly secured thereto in some wellknown manner, as by keying.

The driving-pinion 7 has a revoluble movement about the fixed pinion Gand is shown loosely supported within the shell or casing C. This driving-pinion tends normally to move or rotate; but this tendency will be limited or prevented by the application of' pressure acting thereagainst, making the driving-pinion 7, so long as this pressure continues, a fixed pinion, whereby it will be et'- fective for imparting motion to its mate. lf the pressure against this pinion 7 be rcmoved or reduced, the latter will have a slipping or slackening movement, followed, naturally, bya reduction in speed of the machine or apparatus with which the speed-modifyin g apparatus is connected.

The shell or casing C is illustrated carrying the band Wheel or pulley S, which is shown (see Fig. 14) operatively connected with some suitable form of motor or driving mechanism, a belt 9 being illustrated as passed around said pulley 8 and also around the power or drive wheel l0 of the motor. (Not shown.) The direction of rotation of the pulley S, and hence the casing or shell C, which contains the operative and controlling parts of the apparatus, is indicated by the arrow (t, Fig. 2.

The speed-modifying apparatus embodies also two communicating compartments or chambers, one a pressure chamber or compartment and the other a storage chamber or compartment. A pressure being created in the pressure-compartment and the driving member or pinion 7 being in a position to have this pressure exerted thereagainst, this pressure will ettectually hold said member 7 against rotative movement, whereby it will be efl'ective as a power-transmitting factor. For securing this pressure some suitable fluid will be employed-for example, ordinary lubricating-oil, with which very satisfactory results have been obtained.

` The interior chamber or compartment of the casing C is shown subdivided by the bifurcated partition or wall l2, between the branches l2 and l2 of which the two pinions 6 and 7 will be rotative. This partition or wall l2 is shown separating the inner compartlnent of the casing or shell C into two separate and communicating fluid compartments or chambers, which constitute, respectively, a pressure-compartment for containing fluid under pressure and a storage-compartment, the pressure-compartment being` designated by X and the storage-compartment by X'.

As hereinbefore stated, the two pinions 6 and 7 are supported for rotative movement within the casing C, and the first-mentioned or driven pulley has been described as fixedly secured to the hollow supporting-shaft 2 for rotative movement therewith. There are shown formed in the rear wall 3 and the face or front plate 5 of the casing cylindrical sockets or openings for the reception and rotation therein of the shaft or pin 7 of the driving-pinion 7, the pinion being secured to its shaft in some well-known manner, or these may be integrally formed.

The driving-pinion 7 will have a revoluble rotative ineffective movement or period, and an alternating revoluble non-rotative eiiective movement or period, during which latter movement or period the driving-pinion 7 will be effective as a power-transmitting factor for imparting movement to the pinion G and through this to the shaft 2 and the roll M, carried by said shaft.

The direction of rotation of the speed-inedifying apparatus is indicated by the arrow a, Fig. 2. Let it be assumed that the apparatus is rotating in this direction and that there is no pressure acting against the pinion 7. On the rotation of the apparatus the drivingpinion 7 will be revolved about the driven pinion 6, and the resistance offered by the latter to will have the effect of rotating the dri ving-pinion in a direction coinciding with that of the apparatus and about its own axis, and hence naturally the pinion 7 will be ineffective to transmit movement to its mate G.

On the introduction of a fluid under pressure in the pressure-compartment X the pressure of such fluid acting against the teeth of the pinion 7 on the revolution of the same about the axis of the driven pinion G will e'tl'ectually limit and hold the pinion 7 against rotative movement, whereby the latter, when so held, will be effective to rotate the pinion 6 and through this the shaft 2 and the roll M. By. reducing the pressure in the pressurecompartment the pinion 7 will have a slipping or freer movement, the natural result being a reduction in rotative speed of the pinion 6, and hence the shaft 2 and the roll M supported thereby. As the pressure in the pressure-compartment is progressively decreased a progressively-decreasin g speed or reduction in movement of the pinion 6 naturally follows,due to the progressively-decreasin g pressure acting against said pinion 7.

IOO

IIO

As hereinbefore stated, the apparatus embodies communicating pressure and storage compartments, and for securing the requisite pressure a suitable fluid, as ordinary lubricating-oil, with which very satisfactory results have been secured, will be employed. The fluid utilized will be maintained in circuit form. Starting at the commencement of the operation of the apparatus from the pressure compartment X it will flow therefrom and into the communicating storage-compartment X',

thereby gradually reducing the pressure inV the first-mentioned compartment, followed by a gradual reduction in speed of the driven apparatus, and correspondingly increasing the pressure in the storage-compartment until the pressure in the two compartments is equalized or balanced, at which time the pinion 7 will be free to rotate about its axis, and during the revolution thereof about the pinion 6 Will bc ineffective as a power-transmitting factor, the result being a stoppage of the machine.

For securing a restoration of the pressure in the pressure-compartment to its maximum capacityor limit the rotary movements of the pinion '7 will be utilized to pump or suck the fluid back from the storage-compartment to be discharged into the pressure-compartment X in a manner to be hereinafter described, whereby the maximum pressure in the former may be secured. A

It will be remembered that the inner chamber or compartment of the shell or casing C has been described as separated or subdivided by a bifurcated partition v12,bet\veen the branches 12' and 12" of which the two pinions 6 and 7 are shown supported for rotative and the latter for revoluble movement about the former.

To guard against the accidental escape or leakage of the fluid employed in any other than the desired manner, the inner faces of the branches 12' and 12" are shown as having complementary curvedfaces, the curve thereof being defined by an arc struck from the axes or centers of movement of the two pinions 6 and 7, and the teeth thereof will have a rubbing contact With said curved faces.

The partition or Wall12 is illustrated as having a straight portion 13, in which there is shown formed a port or opening 13', Which affords a communication between the pressure and storage compartments X and X', and through which port or opening the fluid may flow or leak from the pressure into the storagescompartment, thereby reducing the pressure in the first-mentioned compartment or chamber and correspondingly increasing` that in the latter.

As a means for controlling and regulating the flow of the fluid from the pressure to the storage compartment a suitable valve will be employed, the movements of which valve may be controlled by some suitable member or part of the machine or mechanism to which the Speed-modifying apparatus may be applied.

There is shown (see Figs. 1, 2, and 3) located Within the apparatus and formed in the straight portion 13 of the` partition 12 a cylindrical socket 14E, and there is also illustrated tightly seated therein (see Figs. 5 and G) a valve cylinder or chamber 15, which is shown provided with ports 15' and 15", formed in the wall at diametrically opposite sides thereof, which communicate with the port 13' and with the compartments X and f.

The ports 15' and 15, which constitute, respectively, induction and eduction ports, are shown tapered for a purpose to be hereinafter described, and the fluid will flow from the pressure-compartment X into the port 13', thence through the induction-port 15',throu gh the cylinder, and through the eduction-port 15", and again through the port 13' into the storage-compartment X'.

A reciprocative slide-valve is shown at 16, and this valve is operative in the cylinder or casing 15, and Will have opening and closing movements for opening and closing the ports 15' and 15" to either permit or to prevent the leakage or flow of the fluid from pressurecompartment X to the storage-compartment X' of the apparatus.

The valve 16 is shown as reciprocative within the cylinder 15 and as having a reduced portion 16', about which the fluid employed will flow in passing from the pressure-compartment to the storage-compartment.

The face-plate 5 is shown having an opening 5', through which passes the valve-stem 16 of the reciprocative valve 16, a stuffing box 17 being provided to prevent the escape or leakage of the fluid at this point.

The fluid, it Will be remembered, has been described as maintained in circuit form. The pressure thereof in the pressure-compartment X, acting against the teeth of the movable pinion 7, limits the movement thereof,\vhe1e by it will be effective to impart movement to the pinion 6, and through this to the shaft 2 and roll M. The fluid flows from the pressure to the storage compartment, this flow decreasing the pressure in the former, followedby a corresponding reduction in rotative speed of the pinions 6 and 7, and hence of the speed of the driven apparatus.

The tapered ports in the valve-cylinder l5 are preferably employed, as when the valve is first opened a stream of very small volume will flow from the pressure to the storage compartments, which gradually increases in volume as the valve 16 is pushed inwardly or opened farther.

It will be assumed that the pressure in the compartments X and X' is equal and that the pinion 7 is rotating in the direction of the arrow b, the direction of rotation of the casing C being the same; but a partial rotation of t-he pinion 7 is necessary to so decrease the pressure in the storage-compartment as to leave this pressureless when the pinion 7 has made said partial rotation, this causing a restoration in pressure to its normal capacity in IIO the pressure-compartment X, so that on the continued rotation of the pulley the checking or braking influence of the pressure of the fluid will be restored.

The branches 12 and 12 of the partition 12 are each shown provided with a port, that in the branch 12/ being designated by 1S and that in the branch 12l being designated by '18', these communicating with each other and with the two compartments X and X. The branch 12 is shown having a port or opening, and the iiuid may liow through this port, and acting against the teeth of said pinion the pressure of such fluid effectually and positively holds said pinion against rotative movement. On the rotation of the pinion 7 in the direction indicated when the pressure in the two compartments is equal the teeth of said pinion will each take up or suck from the storage-compartment X a small quantity of the iiuid, which will be carried therewith on its rotation and be discharged through the port 1S in the branch 12/ into the pressurecompartment X, thereby increasing the pressure in the latter as the fluid is thus discharged from the rotating pinion into the pressure-compartment 5 but a partial rotation of the pinion 7 is necessaryT to restore the pressure in the pressure-compartment X to its normal or maximum capacity. The valve 1G, it being of course understood, is closed during this peculiar pumping action of the pinion for creating to its normal capacity or limit the pressure in the pressure-compartment X.

It will be remembered that the iiow of the tluid from the pressure-compartment X has been described as controlled by a reciprocative slide-valve which has opening and closing movements, to either permit or to prevent the iiow o'l the fluid from the pressure-compartment X into the storage-compartm ent X. The valve 1G is shownV as a balanced slidevalve, whereby but a minimum expenditure of power will be necessary to insure the positive operation of the same. The body of the valve 1G is shown interiorly bored to permit the liow through said bores of a small quantity of Fluid.

The valve-cylinder 15 is shown provided with a port 19, which communicates with the storage-compartment X; and it will be apparent that the iluid may flow through said port 19 and into the valve-cylinder 15 and thence through the valve-bores to the opposite side of the valve7 so that there will be maintained, throughout the operation of the valve at each end of the valve, a body of iluid, each of which counterbalances the other, and which insures apositive and steady movement of the valve during its opening and closing movements.

As a means for operating the Huid-regulating-valve 1G the latter will be operatively connected with some movable part of the machine or mechanism to which the apparatus may be applied. The face-plate 5 of the casing C is shown provided with a projecting support 20, which is shown supporting a slidable member 21, which is-illustrated operatively connected with the reciprocative valve 1G,and is also to be connected with some operative part of the apparatus or machine with which the speed-modifying apparatus may be connected. The slidable member 21, which has a sliding movement on the support 20, is shown having an upwardly-projecting arm 21', illustrated as formed integral therewith, this arm being also illustrated as connected with the valve-stein 16 of the valve 1G. Then this slidable member 21 is pushed inwardly, it will be apparent that the valve 16 will be thereby opened to permit the low of a stream of fluid through the

ports

15 and 15" from the pressure-compartment X into the storage-compartment X, this flow of the fluid from the pressure-compartment X to the storage-compartment X reducing the pressure of the iiuid acting against the pinion 7, thereby permitting a relatively free or slipping movement of the pinion 7, and hence a corresponding reduction in speed of the roll M. As the iiuid l'lows from the pressure-compartment X into the storage-compartment X through the tapered ports 15 and 15H the pressure in the former is gradually decreased and that in the latter gradually increased, due to the opening movement of the valve, until the pressure in the two compartments is equal or balances, at which time the pinion 7 will be again free to rotate and will be thereby ineiifective as a power-transmitting medium, this peculiar relation continuing so long as the ivalve is in its open position.

On the closure of the valve 1G the fluid will be prevented from lowing into the storagecompartment X from the pressure-compartment X, so that on the rotation of the pulley the pinion 7 will have a revoluble movement about the pinion 6 and a rotative movement about its own axis, during which rotative movement of the pinion it will be effective to pump or suck the fluid from the storage-compartment X to be discharged into the pressure-compartment X until this has resumed its normal capacity or efiiciency, at' which time said pressure, acting against the pinion 7 and iiowing through the port 1S, will cheek or prevent the rotative movement of the pinion 7, and hence the latter will be eli'ective as a power-transmitting factor for transmitting movement to the pinion 6 and through this to the roll M.

As before stated, the slidable member 21, which has been described as operatively connected with the valve 1G, will also be opera-- tively connected with some movable part of the machine or mechanism to which the apparatus may be applied. The slidable member 21 is shown provided with a peripheral groove or channel 22, in which are shown seated the connected straps 23 and 24 or other suitable device for non-rotative movement therewith. A bifurcated actuating-lever is IOO IOS

IIO

shown at 25, and will be pivoted, as at to some fixed part of the machine or mechanism. The support 2O is illustrated as provided with a stop 20" in the form of a disk, which is shown secured by means of a screw 20"' to the outer end of the shaft 2, and is adapted for limiting the outward movement of the member 21. The back plate 3 of the shell or casing C is also illustrated provided with an outwardly-projecting portion 3', and the outer end of this is shown provided with a stuffing-box 2G for preventing the accidental escape of fluid therefrom at this point.

Means communicating with the pressurecompartment X are provided for keeping the same constantly supplied with fluid, so that if from any cause the fluid should accidentally escape or leak fiuid sufficient to compensate for the leakage or loss may be supplied, so that the pressure in the pressurecompartment will be maintained at its proper efficiency throughout the entire operation of the apparatus.

It will be remembered that for supporting the roll M and the speed-modifying apparatus S a hollow shaft has been described. The inner end of the shaftis shown provided with a stuffing-box 27, which is shown having an opening 27 therein, through which is passed the bent tube or pipe 28, which carries, at the opposite end thereof, the fluid reservoir or cup 28, communicating with the pressurecompartment. The pipe 28 is of relatively small bore, so that the fluid will be supplied to the apparatus S under practically no pressure, and thereby not interfere with the accurate working of the apparatus. Tlie fiuid reservoir or cup 2S is also shown provided with a removable screw-threaded cap or cover 2S, which may be removed at will for filling the reservoir or cup 28' with the fluid employed.

The shaft 2 at a point adjacent to the apparatus S is shown provided with a seriesl of openings 2 coincident with an annular channel or depression 29, shown formed in the rear Wall of the apparatus, and communi eating with which annular channel is the port 2f ,Which also communicates with the storagecompartment X. It will be apparent then that the oil flowing from the fiuid reservoir or cup 2S Will flow through the hollow shaft 2 and into the storage-compartment X, from which it may b'c drawn or sucked by the pinion 7 on its rotation in the manner previously described, the oil being discharged into the pressure-compartment X.

In Figs. 9 to 14, inclusive, is illustrated one modification of the apparatus, a different form of valve being illustrated for regulating the flow of iiuid from the pressure-compartment.

The face-plate 5 is shown provided with a proj ect-in g portion 30, in which, as illustrated, is formed a 'curved or tortuous conduit or passage SO, communicating with the compartments X and X', through which the iiuid flows from the pressure to the storage compartment for the purpose of reducing the pressurein the former and hence correspondin gly decreasing the rotative movement of the roll M through the freeing of the pinion 7.

There is shown transversely intersecting the conduit 30 the valve seat or socket 3l, and the conduit or passage adjacent the valve seat or socket 3l is shown reduced.

The fluid-regulating valve is illustrated at 32 as a plug-valve and as having at diametrically opposite sides in its Wall the

tapered openings

32 and 32", which permit, as the valve 32 is opened or turned in its seat, the flow of a gradually-increasing stream from the pressure to the storage compartments of the apparatus.

The valve-stem 33 is shown passing through a stuffing-box 34, which latter is provided to guard against accidental escape or leakage of the fluid employed. The valve-stem 33 illustrated provided at its upper end with an actuating-arm 33, which is shown operativel y connected with the slidable member 2l, and hence through the latter With some operative or moving part of the machine or mechanism to which my apparatus may be applied for controlling the movements of said valve, and hence regulating the flow of the fluid from the pressure to the storage compartments thereof.

The slidable member 2l is shown provided with the inwardly-projecting arm 21, having an enlarged portion, in Which, as illustrated, is formed the longitudinal slot 2l, through which is passed the downwardly-projecting portion 33 of the actuating-arm 253/. It will be apparent that when said slidable member 2l is slid inwardly the arm 33 will be revolved or turned, and hence the valve will be opened to permit the passage of the fluid from the pressure to the storage compartment, and it will be evident that When said member 2l is moved in the opposite direction the arm 33 will be oppositely revolved or turned and the valve closed to prevent the flow of fluid from the pressure to the storage compartment, whereby on the rotation of the pinion 7 the fluid may be sucked from the storage-compartment to again create a pressure in the pressure-compartment, so that on the continued rotation of the apparatus S and the revolution of the pinion 7 about its mate G the latter will be positively held against rotative movement by the pressure of fluid thereagainst and will be effective as a powertransmitting factor.

Having thus described my' invention, I claiml. The combination with a casing comprising two compartments separated by a partition having ports, of two gears rotativelysupported between said compartments; a valvechamber in said partition having a tapered port or ports communicating with said compartments; and a valve operative in said chamber.

2. The combination with a casing comprising two compartments separated by a parti- IOC) IIO

tion having ports, of two gears rotativ ely supported between said compartments; fluidsupply means communicating with one of said compartments; a valve-chamber in said pai tition having a port between said compartments, and having also a second port communicatin g with said fluid-supply means; and a longitudinally-bored valve operative in said chamber.

3. The combination with a casing having two compartments therein, of a valve-chamber with ports; a valve; a pair of gears rotatively supported between said compartments; a hollow shaft for supporting one of said gears and communicating with one of said compartments; and a fluid-reservoir connected to said shaft.

4. The combination with a casing having a bifurcated partition with ports for separating the same into two compartments, said partition also having a socket and a port; of a cylindrical valve-chamber seated in said socket and having diametrically opposite ports in its wall communicatin g with the port in said partition; two gears rotatively supported between the said compartments; and a bored valve operative in said chamber and having a portion of its body of reduced diameter.

5. The combination with a casing separated into two compartments by a bifurcated partition, each of the branches of which is provided with a port; of a valve for controlling the supply of iiuid and a pair of gears rotatively supported between the branches of said partition.

G. The combination with a casing separated into two compartments by a bifureated partition provided with a valve-chamber having a tapered port or ports, 'each of the branches of said partition also having a port; of a pair of gears rotatively supported between the branches of said partition; and a valve operative in said chamber.

7. The combination with a casing separated into two compartments by a bifurcated pai# tition provided with a valve-chamber having a tapered port or ports communicating with said compartments, and having also a port in each of its branches; of a valve for controlling the supply of fluid; a pair of gears rotatively supported between said branches; a hollow shaft for supporting one of said gears and communicating with one of said compartments; and a fluid reservoir conneeted to said hollow shaft.

8. In an apparatus of the class specified, the

combination with a casingfembodyin g a pressure-compartir] ent and a communicating storage-compartment; of a pair of meshing pinions located within said casing, and constituting, respectively, a driven'pinion and a driving-pinion, the pressure of the fluid in the Huid-compartment governing the rotation of said driving-pinion, and the flow of the fluid in the pressure-compartment into the communicating storage-compartment reducing the pressure against said drivin g-pinion; a valve-chamber having a tapered port; and a valve located within said chamber, and having an opening movement to permit the iiow of a stream of gradually-increasing volume from the pressurescompartment into the storage-compartment.

9. ln an apparatus of the class specified, the combination with a casing, embodying a pressure-compartment for containing fluid under pressure; of a pair of meshing pinions located within said casing, and constituting, respectively, a driven pinion and a driving-pinion; a hollow shaft supporting said driven pinion and communicating with the pressure-compartment; and a fluid-reservoir com mu nicating with said hollow shaft.

10. In an apparatus of the class specified, the combination with a casing, having a bifurcated partition separating said easing into two compartments constituting, respectively,

a pressure-compartment and a storage-compartm ent; a port in said partition, and a valve for said port for controlling the flow of fluid from the pressure-compartir] ent into the storage-compartment; and a second port in said compartment for the return-flow of the fluid; and a pair of meshing pinions located in said casing.

ll. In an apparatus of the class specified, the combination with a casing, embodying communicating pressure and storage compartments; of a pair of meshing pinions operative in said casing; a bifurcated partition separating the two compartments, and having the inner faces of the branches of said partition defined by an arc struck from the centers of movement of said pinions, the teeth of said pinions having rubbing contact with said curved faces, and a valve for controlling the supply of fluid from the pressure-compartment to the storage-compartment.

FRANCIS H. RICHARDS.

Witnesses:

FRED. J. DOLE, E. C. WHITNEY.

IOC