US702038A - Regulation of speed and power engines. - Google Patents

Description

No. 702,038. Patented :une lo, |902.4

E. THMsoN. REGULATION 0F SPEED AND PWERENGINES..

(Appumion med Nov. 4, 1899.)

Il ki-V :11% n' I Patented :une lo, |9022 E. THOMSON.

REGULATION 0F SPEED AND PDWER ENGINES.

(Application Bled Nov. 4, 1899.) (No Modem' Y f 2 vsheets-sheet 2.

me nonms Ferias ce, Pnmuumo.. wsnmaron. D. c.

UNITED STATES i PATENT FFICE.

ELU-1U THoMsoN, oF, swnMiPso'oT'r, MASSACHUSETTS.

'REGULATION oF SPEEDj AND PWER ENGINES;v

SPECIFICATION forming pere ef Lettere Patent No. 702,038, dated June 10,1902.

' t Ippiieeiioniea N0ember'4.1s99.j seein No. 735,749. oro man.)

T all whom, it may concern: Y

Be it known that I, ELIHU THOMSON, a citizen of the United States, residing in Swampscott, in the county of Essex and State of Massachusetts, have invented certain new and luseful Improvements in the Regulation of Speed and Power Engines, ofwhich the following is a specification.

a The present invention relates to the-regulation of speed and power engines, such as may be used for the propulsion of automobiles and similarI work.

My invention may be applied to the operation of various types of engines from which power is obtained, and itis particularly applicable to the form of engine forming the subject of my application for patent filed April 13, 189s, seria1N0.'677,449. This en-I gine ispractically anV engine designed for'superheated steam, securing thehighest economy of water consumption for a n on-conden-s-v ing plant, and is provided with'puppet-valves forfsteam admission and a cam-shaft foreplerating the puppet-valves, which cam-shaft may be so moved or adjustedythavt the period of the taking of steam isvaried by making the cut-off early or late. Theexhaust .ofthe engine passes out of steam-ports uncovered by the piston near the end of its stroke, al-

though other exhaust means may ofcourse be provided. Y.

. My present invention relates to the control of such engines and may be briefly described as embodying a centrifugaldevice operated by the engine, which centrifugal `device as the speed rises automatically opens a throttle-valve, which when the engine is stopped is nearly closed. At the same time that the centrifugal device or other speed-responsive mechanism as it gradually opens its throttlecontrol valve on the rise of speed, also diminishes the period of the stroke of the engine during which steam Vis admitted to the cylinder or cylinders. In other words, the cutoff is made earlier as the speed rises.' The longest admission is that at starting, while the throttle-valve is nearly closed or the steam wire-drawn, while the running condition is a throttle-valve wider open as the speed increases and a cut-off earlier as the speed increases. By this means in my invention I am enabled to secure a gradual starting and also to set a limit to the speed of running, depending upon the condition and use ofpower. Forautomobile-work the speed will not in myinyention rise to its highest point except lon a good level roaddemanding small power, andgin such case the running will be vmore economical on account of the earlier cut-0E.` For hill-climbing the speed will automatically fall and the torque of the engine will increase, owing to the longer time of admission of steam during the working stroke. I thus re- "lieve'the operator of all necessity for personal control or attention during these changes, and I also secure -the results by simply providing for the operators use a throttle-valve in additionto Ithe' governing-throttle or inV lcombination with the same, whereby he may fat will open and close the steam-passage to the engine at some'convenient point withL jout seriouslyinterfering with the functions of the otheroperating mechanism, as before outlined. a

In my invention I also provide a means for governing at will the set or adjustment ofthe centrifugal or speed-response control device whereby its action may be changedin .such a waythat its functions may be completedor performed during changes offspeed at diffe-r- 'ent speeds relatively-that is'to say, if the gov- .erning device be set to respond readilyto aj rious forms of engine without departing from" my invention in any essential particular.

Figures 1 and 2 show diagonal viewsofthe engine with my control apparatus attached. Figs. 3, 4, and 5 are views showing its arrangement as applied to the driving of automobiles. Figs. 6 and 7 are other details. Y

Referring now to Figs.` 1 yand 2 C C represent a range of cylinders-sayfour in num- IOO ber-the pistons of which operate cranks contained in the crank case K. (Cranks not shown.) These cranks serve to revolve the shaft upon which the governor G G is mount` ed, and this shaft is geared or otherwise connected by transmitting mechanism to the axle A of the vehicle. The admission of steam to the cylinders is under control of the puppetvalves P, actuated by a suitable cam-shaft K2, the cam projections from which, as indicated at J, are arranged in accordance with well-known principles, such that a motion endwise of the sleeve carrying the cam J J J J upon the cam-shaft will vary the time that the puppet-valves are open du ring the stroke, and in addition a further motion may cause reversal of the engine, though this latter is no feature of the present invention. Other arrangements of variable cams can of course be made. I have, however, shown the one mentioned for simplicity as typifying other arrangements having the same purpose in View. The sleeve carrying the cams J J J J may be made to tend in one direction by a.

spring, as at S, and be positively moved in the other by the Agoverning device to be described. The governor G G may be a centrifugal arrangement, with weights carried on pivoted arms, and a spring S2 may be provided, tending to keep the weights in toward the shaft. As the weights are removed by centrifugal force during the rotation, the spring S2 is compressed in the usual way, and the grooved collar D is moved along the shaft.

`This collar in moving actuates a lever L,

which draws the sleeve carrying the cams J J J J along 'the cam-shaft K2, the camshaft itself being geared to the engine-shaft, as indicated to the left, and splined to the sleeve. The arrangement of the cams J J J J is such that as the speed rises and the collar D moves to the left the narrowing portion of the cams will be brought into action in opening the valves P of the engine for steam admission. On the other hand, when the engine is at rest the spring S (or other device for the same purpose) draws the cam-sleeve over, so as to give the cams their full elitect of keeping the valves P open during a considerable portion of the stroke. A second spring S2 may be provided to act upon the governor G G and may be manually adjusted by a moving collar given any definite position by any operating-lever, or the effect of speed upon the governor may be adjusted in other well-known ways. This collar is indicated simply at D2 and may be used to compress or extend the spring S2, as desired, thereby making the governor G Gvariably responsive to the various speeds or of varying sensitiveness to a given speed.

It must be understood that the governor G G has no function in maintaining a definite speed, as in the case of an ordinary steamengine; neither has it any deinite speed-limiting function, as that will depend upon the work to be done or the resistance to be overcome by the engine. Lever L has in addition an attachment at Z for the valve-stem of the throttle-valve V, which valve when the parts are at rest is almost closed, thus almost completely throttling the steam passing through the pipe T to the engine through the valves P, rbc., it being assumed that the steam comes from below upward in the direction of the arrow. A hand-lever H, which is provided with retaining-catches, so that it maybe placed in any position on the arc A2 by inserting the catch in the notches in said arm, moves a steam admission valve V2. When thrown downward to the right, the handle Il opens full steam from the supply-pipe W to the pipe T. It is sometimes desirable that this action be made to take place in stages of opening ofthe valve. Therefore the notches in the arc A2 to the right of the hand-lever H are provided, as shown, though these are not essential. It is also desirable sometimes that the lever H be used for reversal in reversing the engine. To this end a suitable gearing, as a chain N or other device, is provided for actuating an arm B, the purpose of which is to throw the cam-bearing sleeve upon which the cams J J J J are mounted over to the left far enough to bring into action the sections of the cams, as at J2, which open the valves P for admitting the steam, so as to cause reverse rotation. This reverse action of the handle ll might of course be omitted from my invention, if desired, without affecting its action otherwise. In this reversing action the handle H is thrown to the left. When it is thrown to the right to admit steam, a port b in the valve V2 of quite large dimensions is openedfor the steam-that is, the valve is given a wide opening and the arm B is carried suiciently far to the right so as not to interfere with the movements of the cam-bearing sleeve on the cam-shaft K2 in response to the speed acting on governor G G. 'When the handle His thrown far to the left for reversal, a small port (in dicated at a) may be opened for the steam, so that no rapid motion during the reversal can ever be obtained. The opening E in Fig. 2 shows the exhaust-passage of the engine. Also in Fig. 2 the rod R may communicate the means for operating the stem D2 by changing the tension or compression of the spring S2. V2 may represent one of the wheels of a vehicle driven by the mechanism.

Fig. 3 represents the mounting of a power plantjust described upon the vehicle, driving the vehicle-wheels W2 W2 through suitable gearing. In this case the puppet-valves are shown as four in number in section, and some of the similar parts are lettered similarly.

In the plan view, Fig. 4, similar parts are seen, and the gear-box Y appears, asin Fig. 2, as a case containing gear or transmitting mechanism from the engine shaft to the wheel-shaft. Differential gearing may be IOO IOS

IlO

embodied in this mechanism; but as this is no part of the presentinventi'on there is no need of further describing it.

Fig. 5 shows an end view more in outline than Fig. 2. l The operation of the devices is briefly as follows: Assume the machineat rest and the .handle H in the position shown in Fig. l, with the steam-pressure on the supply pipe W from any suitable boiler or generator. If valve V2 be opened by throwing the handle H over to the right anddown, steam is admitted to pipe T, which is the supply-pipe of the engine; but it is wire-drawn or throttled at V, so that it can escape but slowly to the engine. As the same time the cams J J .IJ are so set that the puppet-valves P will be kept open for admission of steam during, for example, two-thirds ot the working stroke of the piston in the cylinders. Under these conditions the engine will take a moderate start without the care of the operator. There will be no toorapid acceleration; neither will the` drain upon the steam nor the strainsupon the engine be at all abnormal or high. It' now motion is acquired with continued acceleration, the governor G G begins the process of compressing the spring S2 and moving the lever L so as to do two things-wiz., diminish` the time of admission of steam duringthe stroke by moving the cam-carrying ysleeve to the right, and also at the same time that this progressive movement takes place as `thespeed rises the valve V is opened, 'so that it gives much less obstruction to the incoming steam.

, The valve V in this way continues opening the entire throw of the cam-carryin g sleeve is It the sleeve D2 be manually set in new positions, so as to compress or expand this spring S3 differently, then the actions of the governor without being essentiallychanged are slightly modified as to the range of speed they cover. If the vehicle with the handle H thrown so as to open the valve V2 is runningA along on a level and strikes a grade demanding a greater torque, the governor G G will partially collapse and movev the cam so as to Vgive a greater time of admission; but if this occurs to any considerable extent, soas to put too high a drain upon the steam-supply, the throttle V closes and wire-draws the snpclimbing the grade, and thus'the condition of steam-supply in the boiler or generator controls that of steam-supply in the engine.

ing valve V instead of drawing an unlimited amount from the boiler or generator, such as might be the case with the valve V absent. Moreover, the care of this condition is removed from the operator or he is relievedY from any thought of the maintenance of steamsupply, the only control being the opening and closing of thevalve V2 at intervals kby simple motion, the range of whichV need not be accurately adj usted. In going down grade (as when the weight of the vehicle driven by the engine may be suicient to drive the whole plant) the handle H may be moved so as to entirely cut oft the steam, in which case the engine acts in a measure as a brake, or the sleeve D2 may be moved by the operator so as to make the response of the governor G G to speed more sensitive-in other words, a lower speed being attained, will cut vthe steam oft by diminishing the cut-ois to the limit.

Instead of the valve V being at the start slightly open,"as described, there can be a by-pass opening, such as y, Fig. 6, ora bypass valve and operating-lever, such'as y2,

Fig. 7, this valve being adjusted to the de- IOO sired degree of opening for the same purpose as before described.

What I claim as new, and desire to secure by Letters lPatent of the-United States, is;

l. In combination with a variable-speed engine, an automatic regulator acted upon 'by changes in speed, a cut-0E valve, `a throttlevalve,means `for decreasing the period of open ing of the cut-off as the speed rises, and means for correspondingly increasing theopening of the throttle'as the closing of said cut-off takesl place.

2.- In combination with a variable-speed engine, an automatic regulator for'governingl the engine which acts progressively over a wide range of speed, ,a cut-oft valve, a throttlevalve, and meanslactuated by the regulator for correspondingly decreasingthe period of IIO IZO

opening of the cut-ott andincreasing the openj ing in the throttle as the speed of the engine rlses. t

3. Inan automatic regulating device for variable-speed steam or vapor engines, the combination of a cylinder a variable cut-off 'for admitting steam to vthe cylinder, a valve in the steam-supply pipe adj usted to beslightly open at the start, a speed-responsiveA device acting automatically, a means actuated by the device, whichv during the increasevin speed, is arranged to vary the cut-oit in a manner to diminish the time of steam admission, and also to open the throttle-valve in the steamsupply pipe, and manual means for varying the action of the speed-responsive device du ring operation.

4. In combination, an engine having a cylinder, a throttle and a cut-off valve with an automatic regulator for maintaining a constant engine torque comprising a speed-responsive device progressively operative over a Wide range of speed, means actuated by the regulator as the speed rises for gradually opening the throttle-valve, means for actuating the cut-0E valve, and a connection between said means and the regulator whereby as the throttle-valve is opened under antincrease of speed, the opening of the cut-off valve is correspondingly decreased at or about the same instant, wherebya new and definite relation of the valves is established for each change in speed.

5. In an automatic regulating device for steam or vapor engines, the combination of a variable cut-off or steam admission, a throttlevalve in the steam-supply pipe adj usted to be slightlyT opened at the start, a speed-responsive device which,dnring an increase of speed, adjusts the cut-off so as to diminish the time of steam admission, and also acts to open the throttle-valve in the steam-supply pipe, thereby admitting more steam to the steam-chest of the engine, a manually-operated throttle for turning on and off the Steam-supply, a reversing mechanism, and manually-operated means for operating the said mechanism.

G. In an automatic regulating device for steam or vapor engines, the combination of a main throttle-valve, an operating-handle therefor, a subsidiary throttle-valve normally open to a slight extent even when the engine is at rest, a variable cut-0E controlling the steam admission to the cylinder, a speed-responsive device, and mechanism for opening the subsidiary throttle, and at the same time acting on the variable cut-oli? to diminish the steam admission as the speed rises.

7. In an automatic regulating device for steam or vapor engines, the combination of a main throttle-valve, an operating-handle therefor, a subsidiary throttle-valve normally opened to aslight extent even when the engine is at rest, a variable cut-off controlling the steam admission to the cylinder, a speed-responsive device, mechanism actuated by the device for opening the subsidiary throttle and at the same time diminishing the steam admission at the cut-off as the speed rises, and manually-controlled means for adjusting the speed-responsive device for varying the position which it takes under different speeds of running, thereby changing its sensitiveness.

8. In an automatic torque-regulator device for steam or vapor engines, the combination of a speed-responsive device, a subsidiary throttle-valve norm ally opened to a slight eX- tent, puppet-valves for regulating the admission of steam to the engine, cams for actuating the valves, and a leverwhich is acted upon by the speed-responsive device for simultaneously opening the subsidiary throttle and adjusting the cams so as to decrease the interval that the admission-valves are opened on an increase iu speed.

9. In an automatic regulating device for engines the combination of a main throttlevalve, a handle for actuating the throttle, Valves for regulating the admission of steam to the engine, means actuated bythe throttlelever for varying the opening and closing of these valves, a subsidiary throttle-valve arranged to be opened at all times, a speed-responsive device, a pivotally-supported lever acted upon by the speed-responsive device for opening the subsidiary throttle and closing the steam-admission valves, the valves being so arranged that as the throttle-valve opens the admission valves remain closed for a longer period of time, means for opposing the action of the lever, and a spring or its equivalent for adjusting the effect of said means on the lever.

In witness whereof I have hereunto set my hand this 31st day of October, 189).

ELU-IU THOMSON.

Witnesses:

DUGALD MoKILLoP, CHAs. B. BETHUNE.

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