US1317270A - Leox joseph creplet - Google Patents

Description

L. 1. pawn.

AUTOMATIC IEEEAPPARAIUS T0 UNIT All) REGUUIE {HE SPEED OF REVERSIBLE ENGINES. Arrucmon mm act. :0. "1a., sumo "I. i. m0.

1,317,270. Pat' nmdse t. 30, 1919.

3 MIKETHNIH l.

I INVENTOR 3y Ailomeys,

L. I. CREPLET.

AUTOMAIIC IELEAPPAHMUS T0 UMH AND RLGULAIE THE SPEED OF REVERSIBLE ENGINES.

' APPLICATION FILED ocr. 30. 19:64 RENEWED FEB. 6 IQIB.

1,317,270. PatentmlSept. 30, 1919.

3 SHEEIS-SHEEI 2.

INVENTOR i r 1 W!.TNE55= By A llorncys,

Gall/MU! Qwvu M L. J. CREPLET.

AUTOMATIC TELEAPPARAIUS T0 LIMII AND REGULHE THE SPEED OF REVERSIBLE ENGINES. APPLICATION HLED 0U. 30. I916. RlNEWED FEB. 6.1919.

1 ,3 1 '7, 270. Patemodbept. 30, 19:9.

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INVENTORV WITNESS (14 By A llorneys,

UNITED STATES PATENT OFFICE.

LEON JOSEPH GBEPLET, PARIS,- FRANCE.

AUTOMATIC TELEAPPAMTUS TO LII IMI'I AND REGULATE THE SPEED OF REVERSIBLE ENGINES.

Specification of Letters Patent.

Application filed October 30, 1916, Serial No. 128,489. Renewed February 6, 1919. Serial 110,215,455.

To' all whom it may concern:

Be it known that I, Liion J osnrn CnnrLE'r, a subject. of the King of Belgium, residing in Paris, France, have invented certain new and useful Improvements in Automatic Teleapparatus to Limit and Regulate the Speed of Reversible Engines, of which the followin is a specification.-

, his invention relates to variable speed and reversible engines 1nd to direct or remote controlling means therefor of the kind employing an ordinary governor driven by an electric motor the current of which is supplied or controlled by a dynamo driven from the engine to be overned; and the invention has for its 0 ject to provide im-' roved means for controlling such engines. ihe aforesaid type of controlling means is described in the specification of British Letters Patent No. 16,673, A. D. 1913, granted to me.

Accordin to the resent invention the engine (tur ine) or ot ier machine to be controlled drives a. dynamo which is in circuit with a constant voltage dynamo of higher voltage driven from an independent source, the two being inversely connected in the circuit, so that any diminution in speed of the former results in an increased resultant voltage in the circuit, or vice versa; and in the sa'nie circuit is introduced an electromotor which responds to such variations of voltage, whereby its speed varies inversely with variations of speed of the engine to be controlled; and this motor drives a centrifugal governor which in turn controls such engine, as by meansof its throttle. By means of a variable resistance inserted in the excitation circuit of such motor, the standard of normal speed of the latter, and

' hence that of theengme under control, may

gram;

Fig. 3 is a speed diagram;

Fig. 1 is a view illustrating the application of the invention to the control of marine turbinesfor driving a shi either forward or backward, the mechanical apparatus being shown in elevation and the electrical connections in diagram.

Referring first to Fig. 1, A is the machine, engine or prime mover, the speed of which isto be controlled, for example, a steam turbine: a is a shaft of this engine, which may be its power or driving shaft; d is a dynamo driven directly or indirectly from the shaft u; c is a constant voltage dynamo driven from any independent source; m is an elec tromotor which directly or indirectly drives a governor R, which latter is the governor controlling the engine A, as, for example, by means of a throttle P controlling the How of steam to such engine. Dynamo d is shown excited by a field coil b in shunt to dynamo c; dvniuno a is shown as excited by a shunt fiel coil f; motor m is shown as excited by a field coil h which is connected in sh'unt through a variable resistance or the dynamdd, whose excitation is constant for any given setting of the rheostat 1', furnishes 120 volts when its driving shaft 0 runs at the normal speed; that the direction of thcrlectromotive force D of dynamo d is opposed to the electromotive force E of dynamo 0, so that the voltage V fed at m is always the difference E-I), and hence has a value of 120 volts at the normal speed of the machine A; and that the governor R runs at a normal speed of say 240 R. P. M., for which speed the admission of steam corresponds to the work of the machine when the excitation of h is a minimum, and V is equal to 120 volts (neglecting the variation in speed of the governor from O to about five per cent., according as its sleeve is at the top or bottom of its movement.) Under these conditions, so long as the load of the machine A does not. vary, its speed and that of d is constant; the volta e V then remains Patented Sept. so, 1919.

example, the load increases, A and d slow V increases b the same amount; m and R speed up an the latter acts in the usual manner to increase the admission of steam. Thus, each time that the machine A runs irregularly the speed of R is affected inversely, and it varies the steam admission to adapt it to the new work required of the machine.

If it is desired to change the normal speed of thema'chine A, the rheostat r is moved, which varies the excitation of m and hence varies the s eed of R; thereby a new standard of spec for A is established.

The governor may be installed to act either as a means for limiting the speed or as a regulator of the speed.

Speed Zimiter.In the first case it only operates when the number of revolutions of the engine exceeds a predetermined value and it remains inactive so long as the number of revolutions is below that allowed. This is the case in winding engines, lifts, tram cars etc.

The speed-limiting apparatus fulfils five functions.

1. When starting, it is required only to act for the purpose of obviating shocks and excessive accelerations;

2. When the speed is constant, to prevent it from exceeding a predetermined value;

3. Starting from a certain position of the load to cause the engine to slacken radually so as to reach the desired point s owly;

4. If in consequence of inattention or of a wrong movement on the part of the operator the desired point is passed, to stop the engine before an? damage is done;

5. To modi y the rate of speed according to the circumstances of the work, the nature of the load, etc.-

To fulfil the first four conditions the position of the sliding contact of the rheostat is made to correspond with that of the load by means of any suitable mechanical connection, while being at the same time also under control of the control lever. Each time the control lever is displaced the slidingcontact moves a distance such that the governor is caused to act effectively on the valve gear of the engine.

This will be made clear by reference to Fig. 2,.which shows, as an example, a machine A which may be a hoisting engine such as are used in mines. The sliding contact r of the rheostat r is displaced by motion derived from the shaft 41 under control of lever L, which in this instance may correspond to the. ordinary reversing lever of such hoisting engines. From the shaft 0. is

driven, through reducing gearing, a shaft S from which movement is transmitted to the sliding contact 1'' at such rate that the latter makes nearly one complete turn while the load or cage of the hoist is making its complete travel.

The governor R, driven as before by a motor m, acts in the same manner as before described on a throttle P controlling the admission of steamto the engine. The governor R also acts on the controlling element F of the brake for the engine or hoisting drum, which element may be any known brake-controlling means. The connection between the governor sleeve and the throttle actuates the latter throu h a spring 15 which is compressed after the I rottle is closed, so as to permit the governor to a ply the brake when its sleeve completes its escerit. When the sleeve is at 21: the governor makes, for example, 245 R. P. M., the throttle is open, and the brake is ofi when the overnor falls (say) from 245 to 240 RP, the sleeve descends to 3/ and closes the throttle. If the governor continues to slow down, assing (say) from 240 to (sa 235 R. P. the sleeve descends to 2 while compressing the spring 15, and lifts the con-trolling arm of the brake-applying device F, which is thus applied more and more as the governor continues to slow down. It is understood that when the throttle is closed it will rmit suflicient leakageof steam to enable t e operator to manipulate the machine at all times, but at very slow speed.

The reverse lever L 1s conntcted in the usual manner to a shaft C which operates to IPXGIISG the valve gear in any known manner. An arm on this shaft carries a roller g which may occupy one of three .positions, v1zz- (1) when the lever is in the stopping position L";

(2) 9 when the lever is thrown fully over to L for'running forward;

(3) f when the lever is thrown fully over to L or running backward.

The roller g, when displaced to g or g, tightens a chain 11 which connects a pulley or sprocket wheel on the shaft S to a similar. wheel on the arbor of the sliding contact 1",- so that each time the lever L is displaced to drive the machine forward or backward, this causes a certain displacement of the contact r. This displacement, when the load is at the bottom of its tra'vel and the lever is thrown to L, causes the contact arm to ass from n to 'n (the resistance of the mac ine A preventing the chain from turning around the shaft S), which speeds-up the-governor and admits steam.

If the lever L were to be thrown in contrary direction to L, this would bring the roller to g and displace r from n to a, a position which slows down the governor so that its sleeve falls to z, and the brake is applied to prevent the niwchine'from runmug in the wron direction. Thus in the case of a hoist, w en the cage is at the hottom and the lever is brought to L, the brake is set, preventing the starting in the wrong direction; on the contrary when the cage has reached the to of its course the same movement of L to moves arm p away from n, which releases the brakeand allows the descent. I l

The resistance introduced in traversing the are from n to n is so proportioned that the throttle is opened sufiiciently to run the engine at a speed which is rapid with.- out being dangerous. 0

Fromvn to it the sliding contact 1*, by reducin the magnetism of motor m, tends to spec up the governor; hence the engine accelerates, this being the period of starting 0, Fig. 3. From a around to n the sliding contact does not modify the excitation of motor m; this is the period of normal runnin at constant speed a b, Fig. 3. Beyond 12 t e contact gradually increases the ex' citation andreduces the speed of the governor, which gradually cuts 01f the steam, and the engine slows down until at n the throttle is closed and the engine stops (in period bC, Fig. 3). If at this moment the engine is not sto ped, the governor slows dgwn enon l1 furt er to apply the brake.

Toward t 1e end of the travel the engineer, accordin to habit, throws lever L from L to L9. f he should forget to do this the contact 1" will arrive at a" before the end of the travel and will pass beyond this position, thus breaking the circuit through c; in consequence, the governor will slow down and apply the brake, thus avoiding all danr. Each time that the engine A reverses its direction, the electromotlve force D of the d namo d is reversed. This voltage must always be opposed to the voltage E, which is constant; to realize this condition a polechanging commutator may be introduced, driven by friction from the shaft 0:. This commutator is introduced between the armature of d and its exterior circuit in such manner that at each reversal of direction it transposes the connections. Such commutators and their mode of control are well known and form no part of the present invention.

The fifth object isattained, as will be seen, by having as much sliding contact resistance available to insert in the exciting circuit of the motor as eorres ends to the range of speeds to be realize Only one resistance is then in operation at a time, the others being cut out.

The maximum speed A (Fig. 3 depends upon the variation of magnetization which the sliding contact 1" produces, that is to say, upon the amount of the resistance which it introduces and suppresses gradually.

Let us assume, for example, that the maduced by half.

If there is given to the regulating re- ',sistance a value still less, the maximum speed of the machine will be reduced still more.

There will be provided as many regulating resistances for the sliding contact r as it is desired to have of maximum normal running speeds, but there will never be more than one 1n service.

The more the magnetization of m, that is to 'sa the voltage of its field h is varied, the greater will be the maximum speed of the machine A (Fig. 3).

A great number of maximum speeds A", A", etc., can be attained by varying the voltage of the field of m in the following manner. Upon the regulating rcsistum-e controlled by the. rheostat r, there is arranged in parallel a second resistance thatis modified by a sliding contact 8 (Fig. 2) operative by and; For example, if s is at a, all resistance is eliminated and no displacement of T will modify the magnetization of m and consequently the machine is forced to stop.

If s is put at 8,, the displacement of '1' would produce in the magnetization of mthe maximum variation.

On bringing it successively from s, to s, the machine will take on all maximum speeds from zero to A (Fig. 3).

Speed 'rcgulatar.lVhen the apparatus is re uired not merely to limit but also continua ly to govern the engine. the operator operates the sliding contact directly, and it is then made independent of the engine A. For moving the contact it may be carried by a hand lever L.

Each time the operator displaces this lever the governor acquires a new speed. and consequently by acting on the valve gear of the engine nnparts a new speed to the latter.

Before displacing the sliding contact the operator must set the valve gear of the engine in the required direction. The two operations are under control of a single lever L, as has been described with reference to Fig. 2.

When a forward and reverse movement of the drive shaft are obtained by two separate engines (on turbine boats for examp c).the mechanism opens sometimes the regulating valve of one engine and sometimes the reguto the lating valve of the other, accordin be dedirection of motion required, as wi scribedwith reference to Fig. 4.

This object may well be attained by roviding. each engine with a governor. he control lever then acts on the excitations of the motors operating the governors in the desired dii'ection.

This is illustrated in Fig. 4 where the two engines A A have their a mission valves P P operated by governors R R driven respectively by the motors m, m, the fields of which are in series with two rheostats r 1' controlled by sliding contacts r connected to the control lever L which is movable from the stoppin point Lto either full ahead at L or full astern at L. When this lever is at the stopping point the contacts occupy the ositions shown, the two governors then having their sleeves fully down and their admission valves closed. To run forward L is displaced from L to L, which leaves 1' out and cuts in 1-; this speeds up m and R, which latter 0 ns the forward admission valve P, driving the forward engine A while the motor m preserves an invariable s' eed, because the resistance 1' does not c ange. For runnin backward the contrary movement is ma e, which drops R to the mini-mum and speeds up m R which opens the admission to the backward runmug engine A. The governors R R may operate the admission valves P P in any suitable manner, as throu h the intervention of auxiliar oil motors, t e valves to which are control ed by the governors, as is well known and in common use on electro-generating turbines of constant speed. The main circuit has at E a uniform volta e generated by a dynamo (as c, Fig. 1), and is in series with the dynamo d which is driven from the propeller shaft a, the electrical arrangement eing thus the same in this respect as shown in Fig. 1. The pilots control apparatus Q is shown as similar to the existing marine telegraph. The lever L carries the sliding contact T which always makes contact with an are u connected to one circuit lead, and in its .midosition L" makes direct connection throug sliding contacts with the wires leading to the res ective exciting coils of the motors m 111.. Sn displacing the lever in one direction toward L it introduces the resistance r in series with the exciter of m; on dis lacing it in the contrary direction towar L it introduces the resistance r in" series with the exciter of m. By means of a reversin commutator as referred to hereinabove, t e electromotive force D generated by d 1 :is always opposed to the exterior voltage a g It results from these: arrangements that we have in the motors m m 240 volts when the screw is at rest;

240120=120 volts when the screw is at full speed forward or backward.

The governors are so adjusted that the sleeve of each is at its bottom stroke with the admission valve closed, as for example, 240 R. P. M.; or at its top stroke with the admission valve open at 250 R. P. M.

The resistances r r are so proportioned that when the screw is at rest, that is, when the voltage at the motors m m is at 240 volts, the governors make 3-240 R. P. M. for R and 240 R. P. M. for R if thehandie is at L; 500 R. P. M. for R and 240 R. P. M. for R if the handle is at L '240 R. P. M. for R and 500 R. P. M. for in if the handle is atL. v

Hence, if the handle is thrown from D to L, R accelerates and opens the admission valve P and the screw is driven (say) forward; R slows down as the potential at the motors gradually diminishes. At full speed it falls to 120 volts, which gives for the governors '-vm=250 R. P. for R.1

Consequently, the admission valve P for engine A is wide open and valve P remains closed. If the screw tends to race, as on lifting out of water, R slows down, shutting off the steam and reducing the speed to the normal.

It will be understood that for each intermediate position of the handle L the screw will take a speed roportional to the angle of dis lacement o L. When reversing the contro handle L, the conditions are reversed and the screw is driven in the contrary direction. v

.If the screw is at full speed and it is desired to reverse the speed very quick] it is only necessary to throw the andle over from one extreme position to the other. If from L to L the excitation of motor m is increased by (say? 4%, m slows down to 240 R. M. P. and a] steam is cut off from the turbine A. If the pilot thus reverses the lever instantl that is, before the screw has time to slow own, the governors at the end of this'movement will have 120 volts at their 12O R. P. M. for R motors; their speeds will therefore be half of that given above when the screw is at rest and the lever at L, namely =120 R. P. M. for R and g2=25o a. P. M. for R,

which shows that the governor for engine A is open, admitting counter-steam. Under the efi'ect of this steam the screw slows down rapidly, thus causing the voltage at the mothat the voltage it delivers is proportional'to its number of revolutions. A voltmeter shunted across its terminals will indicate or register at any distance the speed of the engine at ever instant.

In order t iat the governor may control the machine or engine to which it is attached according to a specified rule of working, it is not always suilicient that. it should act on Ihe driving force. In a case where the kinetic energy accumulated in the engine would prevent it from slowing down, or

where the engine continues to move in spite of the elimination of the driving force (as in the case of a hoist when the load is descending) it is necessary for the governor to create a resisting efl'ort. It may apply either the brake, or the counter-pressure steam (i. e. the steam used for reversing an engine) or a eounter-curi-(mt in an electric motor.

What I claim and desire to secure by Letters Patent of the United States is 1. llleans for controlling the speed of a machine comprising a governor, an electric motor continuously driving such governor, a

circuit feeding said motor including a source of constant voltage and a dynamo ,driven by the machine to be governed, generating a lesser variable voltage with its po tcntial opposed to that fromksaid source, whereby the speed of the motor varies in versely to that of the dynamo.

2. Means for controlling the speed of a machine comprising a governor, an electric motor continuously driving such governor, a circuit feeding said motor including a source of constant voltage and a dynamo driven by the machine to be governed, generating a lesser variable voltage with its potential opposed to that from said source, and

, a variable rheostat for controlling the excitation of said motoiz.

3. Means for controlling the speed of a machine comprising a-governor an electric motor continuously driving sue governor, a circuit feeding said motor including a source of constant voltage and a dynamo driven by the machine to be governed, and a plurality of variable rheostats'for controlling the excitation of said motor, having independcntmeans for o ratin them.

4, Means for contro ling t e speed of a machine comprising a governorthercfor, an electric motor contmuously driving the governor, a circuit fat-din such motor, a dynamo in said circuit driven by said machine, and means independent of said circuit for varying the excitation of said motor.

Means for auton'iatically controlling a reversible machine comprising a governor and a control gear including a reversing lever, an electric motor continuously driving said governor, a circuit feeding such motor, and means inde ndent of such circuit for varying the excitation of said motor, comprising a rheost-at operated by said reverslng glelar.

6. cans for controlling the speed of a machine, comprising a centrifugal governor controlling such machine, an electric motor driving such governor, a circuit feeding such motor, including a source of constant voltage, and a dynamo ,driven by the machine to be governed, and means controllable inde pendently of said circuit for varying the excitation of said motor.

7. Means for controlling the speed of a machine, comprisin a centrifugal governor, an electric motor riving such governor, a circuit feeding such motor, such circuit having a source of constant voltage, a dynamo of constant excitation driven by the machine to be governed, connected in said circuit, with its electromotive force opposed to and less than the voltage from said source, whereby the speed of the governor motor augments as that of said dynamo diminishes, and vice versa, so as to actuate the governor in the direction required for the regulation of the machine.

8. The system of claim 7 combined with means for varying the standard speed, comprising a resistance introduced in the inductor circuit of the governor motor, with 111811.

ually controlled means for varying such resistance.

9. The system of claim 7 combined with means for reversing the direction of rotation of such machine.

10. The system of claim 7 combined with means for reversin the machine, operated manually, and sp -controlling means 0 erated automatically from the machine to governed.

11. The system of claim 10, including a rheostat for changing the resistance in the inductor circuit of the governor motor, operated from both the reversing means and the machine. r

12. The system of claim 10, comprising a rheostat for chan 'ng the resistance in. the inductor circuit 0 the overnor motor, and means for operating it rom both the reversng means and the machine, such means comprising a connection for shifting the rheostat geared to'the machine to be governed,

and a connection to the reversing means signed my name in the presence of two subadapted to displace the rheostat to vary the QCIlblIlg wltnesses.

speed of the governor motor and hence to LEON JOSEPH CREPLET. centre} the speed of the machine in either Wit 5 dlrectlon. CHAS. P. PRESSLY,

In witness whereof, I have hereunto HENRI CARTIER.

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