US2400442A - Control apparatus - Google Patents

Description

May 14, 1946.

R. R. STEVENS CONTROL AEPARATUS IFiled March 50, 1944 ATTORNEY Patented May 14, 1946 Roy R. Stevens',` Forest Hillsla.,v assignor to The I Westinghouse Air Brake Company, Wilmerding,\Pa., a corporation of Pennsylvania .Application March 30, 1944, Serial No. 528,677

s Claims. (o1. 121-387) y This invention relates to 'control apparatus and more particularly to means for controllingfthe speed or power output of an internal" combustion engine. l

lIn internal combustion engines, such as the Diesel type', which employlcompressed air for controlling the starting ofthe yengine and for4 controlling the supply of fuelto the engine,..it is desirable when the engine is running, that/a loss i of the compressed air, dueforexample 4tcl-rupture of a fluid pressure supplypipejwill not re, sult in stoppingv ofthe-engine, sinee-it'- mightibe impossible to restart the engine.r Further, such undesired stopping of. the engine might result in a disaster which could possibly be averted if the engine did. noty stop,y by control of the engine speed or output by auxiliary speed control means sucliv as hand operated throttle lever on the engine.

The vprinci-pal object of the invention is therefore the provision of a pneumatic speedcontrol apparatus for an internal Vcombustion kengine which provides for adjustment of the 'speedfand amount to allow operation of the engine at a minimum or idling speed, and to supply fuel to the engine in an amount to cause operation of the'engine at a maximum speed or maximum degree of power output. Adjustment of leverZ toA any position between idle and "full speed is adapted to vary the fuel supply to the engine as required to provide for operation ofthe engine at a corresponding speedV or degree lof output..

'For controlling adjustment of lever 2, there are provided in the structure shown in Fig. lja speed control'device '3 and a stop device 4, while an operators control valvedevice 5 is arranged to control operation of the devices 3 and 4.

The speedv control device 3 comprises a casing containing a movable member preferably in the form of a flexible diaphragm 6 having at one side a pressure chamberv 1 open to a speed control pipe 8 andhaving atvthe opposite side a non#l A rod Ill-is secured cen-l pressure chamber 9.1

by followers II andI2 trally to the diaphragm and a nut I3 and extends through the non-.presfor stopping ofthe engine by ui'd under prese. y

sure and which isso arranged as to prevent stopping of the engine in case of loss of the supply of fluid under pressure. l

Other objects and advantages will beappa'rent from the following more detailed description of the invention. 'i

In the accompanying drawing, Fig, l isA 'andia-' grammatic view, partly Vin section and partlyl in outline, yof a fuel control apparatus embodying one form of the invention; and Fig.- 2 is a view similar to a portion of Fig. l butembodyinganother form of the invention.v

Description," l Y' As shown in Fig; 1, ther reference numeral., I..

indicates a rockable shaft for'v varying thefuel supply to an internal combustion engineand for" cutting olf the supply of fuel to said' engine'.` lThe shaft I may control thesupplyof fuel directly-by".

being arranged to adjustv the fue] injectors lon* the engine, or, if desired,'said shaft may kcontrol the adjustment of .a speed governor' arranged to control the fuelsupply to the engine. The` spe-v cific fuel control means controlled by thejshaft'.

.I is immaterial to the invention.

A lever 2 is connected y'to shaft Ifoiff'rockirig.

have stopj` idle and i" full speed positions as indicated in thedrawingi for adjusting the shaft I to provide, respectively,

same and this lever may for cutting off of the supply of fuel to the engine. to stop it,tcl supply fuel to the engine in an sure chamber 9 .and a suitable :bore in the casing tothe' exterior thereof. A calibrated regulating spring I4 encircling the rodrIU within the nonpressure chamber is supported at one end on the casing, while the opposite end bears againstv the' follower II. The spring I4 is` under pressure for urging the diaphragmli to the position shown in the drawing and to oppose, with increasing force,

movement of said diaphragm and of rod IIJ from this position to a position which may be defined by follower I I contacting the casing..

The stop device 4 comprises va casing containing' a'mcvable member which may bein the form of a piston I6 having at one side a chamber I'I open to a control pipe II!` and having at the opposite side a non-pressure chamber I9. A rod r2Il secured at one end to piston I6 projects at its opposite end against piston I6.l This'spring through the non-'pressure chamberl I9 and a suit' able bore in the casing to thel exterio'rthereof.

A spring ZI eneirclingrod' 2ll within chamber I9 issupported at'4 one end on the casing and bears is under pressure for constantly urging the piston I6 in thedirection for contact With an vannular stop 22- provided in pressure' chamber II and isv operativel to yieldably oppose movement of said l. piston from this position to a position' arranged tobe defined by contact between said piston and an annular stop shoulder 23 provided in the nonpressure 4chamber i9.

The piston rod 2i! extends from the pistonin the same direction as the rod I0 extends from the diaphragm G, and the end of rod 20 is connected by a pin 24 to one end of a lever 25, while the end of rod I3 is connected by a pin 25 to said lever intermediate its ends.- The opposite end of lever 25 is connected by a pin 21 to one end of a link 28, while the opposite end of Said link is connected by a pin 29 to the free end of the engines speed or fuel control lever 2.

The operators control device may comprise a self-lapping valve device 30 of any suitable structure arranged to either open the control pipe 3 to .atmosphere or to supply fluid from a fluid pressure supply pipe 3| to pipe 8 at any desired pressure up to a maximum degree. For

able in the position shown in the drawing to pro-f vide for opening of pipe 8 to atmosphere and operable upon displacement from this position into the device to supply fluid to pipe 8 at a pressure proportional to the degree of such displacement.

A cam 33 mounted to turn with a shaft 34 is provided for controlling the plunger 32, and a lever 35 is connected with shaft 34 for turning same. The llever 35 has stop, idle and full speed" positions as indicated in the drawing and which positions it will be noted correspondA tothe positions of the fuel controllever 2.

The peripheral surface of cam.33 Iwhich contacts plunger 32 is so formed as to allow movement of said plunger to its outermostpo'sition shown in the drawing with the lever 35 in and between stop and idle positions, but to displace said plunger into the self-lapping valve device 33 upon movement of lever 35 from idle position in the direction of full speed position, and to permit movement of said` plunger out of said device upon movement of said lever in the direction from full speed position to idle position. The cam 33 is so designed that the degree of displacement of the plunger 32 into the selflapping valve device will vary in proportion to the distance the lever 35 is away from idle position, whereby the pressure of nuid effective in pipef8 may be adjusted between atmospheric pressure provided in idle position of lever 35 and any degree up to a maximum which will be obtained with said lever in full speed position.

The operators control device further comprises a poppet valve 36 contained in a chamber ,37 and arranged to .control communication between said chamber and a chamberY 38. Chamber 3'| is connected to the fluid pressure supply pipe 3|, while chamber 38 is connected to pipe I8. A spring 39 in chamber 31 acts on the valve `36 for urging it towards its closed position, and saidvalve is provided with anunseating stem 4U projecting through chamber 38 and a bore in the casing into operativealignment With the peripheral surface of cam 33. Beyond that portion of cam 33 that is arranged for operating plunger 32 of the self-lapping valve device 33, there is provided a raised portion 4| forengaging the valve stem 43 to open the poppet valve 36 when the operators control lever 35 is moved into the stop position. When the .operators control lever 35 is in idle and full speed position or any intermediate position, the raised portion 4| will be moved out of contact with valve stem 4G `to allow closing of valve 33 by spring 33. rihe valve stem 4i! may 'be provided with one or more uid pres-v sure release grooves 42 of such length as to conneet chamber 38 to the exterior of the casing and atmosphere with the valve 36 closed. With valve' 36 open the outer ends of groove 42 will be dis,-

posed within the bore in the casing in which the valve stem 40 is mounted.

In operation, with the operators control lever 35 in stop position, the self-lapping valve device 30 will open pipe 8 and thereby pressure chamber 'l in the speed control device 3 to atmosphere, so that spring |4 will be permitted to hold the diaphragm Il and rod IU in the positions shown in the drawing. Further, with the control lever 35 in stop position, the poppet valve 33 will be open and allow fluid under pressure to ow from the supply pipe 3| to pipe |8 and thus Vinto pressure chamber in the stop device 4,

and' this pressure, eiective on piston I6, will ymove-said pistonand the rod to the position 4 in which it is lshown in the drawing.

' With the speed control rod I0 and stop device rod 20 both positioned as shown in the drawing, the lever 25, and linkf28 will assume the positions shown in the drawing and thus position the fuel control lever 2 and shaft in their stop positions for cutting oflthe supply of fuel to the engine to permit stopping thereof.

To allow the engine to be started and then run, the lever 35 may be moved from stop positionv to idle position and the engine may be started in conventional manner in response to such movement of said lever or by an independent maneuvering control lever, which, however is immaterial tothe invention. n

The movement of lever 35 from stop position to idle position, however,-permits closure of the poppet valve 36 andl release of fluid under pressure from pressure chamberi'l in the stop device 4 by way of the release grooves 42 in the poppet valve stem. Piston I6 in the stop device 4 is then moved by spring 2| into contact with stop shoulder 22 and this pulls the connected end of lever 25 in toward the casing to a new position.

With the operators control lever 35 in idle position still opening chamber 7 in the speed control 3 to atmosphere, the parts of said device will be in the position in which they are shown in the drawing so that movement of lever 25 by the stop device 4 as just described will rock said lever about its connection with the speed control device 3 and pull the fuel control lever 2 from its stop or fuel ycutoff position to its "id1e position to provide for supply of fuel to they engine in an amount suflicient to allow starting of the engine and operation thereof atan idling speed.

It will now be seen that this movement of the operators control lever 35 from stop position to idle position has no effect upon the speed control device 3; it merely causes operation of the stop device 4 to move the fuel control lever 2 to its idle position.

At the time of starting the engine, the operator may desire to provide a greater amount of fuel to theV engine than obtained in idle position of lever 2 and this may be accomplished by moving the lever 35 from stop position past idle position in the direction of its full speed position to any desired degree. Upon such operation of lever 35, the stop device 4 will operate as above described to change the position of the connected end of lever 25, and at the same time the self-lapping valve device 30 will operate to supply through ,pipe 8' to chamber in the speed controldevice 3, uid lat a pressure corresponding to the position of the operators control lever 35.

When the pressurey of fluid thus provided in chamber 'I of the speed control device 3 is inatomic` 3,

creased suiicientlyptozovereome spring I4, the

.diaphragm 'will move or'defle'ct to a position inI whichthe increasing 'pressure of said spring balances the pressurev of fluid. This movementof diaphragm 6 andlrod ||J AVwilly rock the lever 25 about its connection withlrod 2i) of-,the stop 'device 4, and thuspullthe fuel-controlrlevery 2 past its idle position'in the direction of full speed to a position corresponding to the position of diaphragm 6 in the speed control'device 3 and thus in accordancewith the'speed posi' tion of the operators control lever 35. After the engine is 'startedit will thenrun on fuelat a speedv determined by the'position of the fuel control lever 2 which corresponds tothe position of the loperators control lever.

'After the engine has been started `and is run'- ning on'fuel, 'the operator, by moving his con-V ent. It will thus be seen that withilui'd under pressure j released from -'the stop device 4, the operator by proper adjustment of lever 35 between idle and full speed may*` obtain operation of s the engine at any desired speed. n

When the operator desires to stop the engine he will move the control lever to stop position to open chamber v1 in thespeed control device 3 to atmosphere and to permit the parts `of' said device to return to the position in whichthey are shown in the drawing. vThis operation of lever 35 also opens thepoppet .valve 3.5 to supply fluid under pressure to the stop device 4 for causing the 'parts thereof to again assume the position in which they are shown Vin vthe drawing, and this operation of the stop device' actuates lever 25 to positively returnrtheY fuel control Ylever 2 to its fuel cutoff or stop position for cutting off all supply of,r fuel tothe engine to stop it.

From the abovek description it will now be seen 0 that since fluid under pressure is released 4from the stop device 4 while the engine is running, a failure or loss of the supply of fluid under pressure through pipe 3| to the operatorscontrol device and a consequent lossof fluid under pressure from chamber 1 in the Speed control device 3, will only result in operation of the speed control device 3 to move the fuel control lever y2 to "idle position. A loss of fluid under pressure will not therefore cause stopping of the engine. In order to stop the engine fluid under pressure is required for operating the stop device 4.

If desired, the functions of the speed control device 3 and stop device!! may be combined in a single device, such as a speed and stop control device shown in Fig. 2.

The speed and stop control Vdevice 45 comprises a casing containing a movablemeinber 46 having at one side a pressure chamber 41 arranged to is arranged for engagement byl follower to limit deflection-of.diaphragm 46 in the opposite direction by fluid under'pressure supplied through pipes td chamber 41. The non-pressure chamber 48fcontains a coil spring 55a which encircles the rod-49 and one end of said spring engages the follower 50. The parts so far described correspond functionally to parts of the speed control device 3..

The diaphragm operated rod 49 loosely extends through a central opening provided in a spring seat and the outer end of said rod is connected by. a pn'5lA to a lever 51 corresponding functionallyto lever-25 inFig. 1 of the-drawing. One end of llever 51 is connected by a pin 53 to alink 59, the opposite end of which link is fulcrumed on a `pin secured in the casing of the structure. The opposite end of lever 51 is connected by pin-21 to link 28 which is connect-ed by pin 29 tothe fuel l control lever 2. y

'rhespring seat 55 is mounted to vslide man' opening provided through the casing and is provided in -the'non-pressure chamber 4B with an enlarged cup-shaped portion 6| in which the adjacent end of control spring 55a is supported. The

:portionof yspring seat 55 Yextending through the casing isiprovided with screw-'threads upon which an adjusting nutv 62 is mounted outside ofY the casing. This nut |52 is provided Vfor engagement with the casing to limit movement of the spring seat 55 into the non-pressure chamber 48, while contact between the cup-shaped portion 6| and the interior wall of the non-pressure chamber is adapted to limit movement of the spring seat 55 in the opposite direction. s I

' Ihe speed and stop control device 45 further comprises a movable member preferably in the form of a flexible diaphragm E3 having at one side a pressurechamber 64 connected to the stop pipe I8 `and having at the opposite side a non-pressure `chamber 65. A follower 66 disposed in chamber in contact with diaphragm 63 has a stem |51y and supplying fluid underpressure to pipe I8, dia- I phragm chamber 41 will be open to atmosphere while fluid under pressure will be supplied to diaphragmy chamber G4. The pressure of uid thus effective on diaphragm 53 will actuate said diaphragm to rock lever 59 in a clockwise direction which will move the spring seat 55 into the nonvpressure chamber 48 to the position defined by contact between the nurl 62 and the casing. This movement of spring seat 55 will change the positionof `the supported end of spring 55a which be connected to the speed control pipe 8 and hav@-- ing at the opposite sidea non-pressure chamber; '48. A rod 49 is connected centrally to diaphragm 46 by means of followers 5|] and 5| and a nut 52. The casing is provided with a stop shoulder' 53 for contact by follower 50 to limit deiiection of diaphragm 45 in one direction, While a shoulder 54 will rexert sufficient pressure on the diaphragm follower 50 to deilect the diaphragm to the position shown in the drawing, and the resulting movement of rod 49 will rock the lever 51 to move the fuel control arm '2 to its stop position.

In order to move the fuel Acontrol arm out of its Astop position to supply fuel to the engine toy permit starting and running ofthe engine, the

operator 'ivill move control lever 35 from its stop position to some position beyond idle in the direction of full speed in order to supply fluid at some degree of pressure in excess of atmospheric pressure .to pipe 8 and thus to diaphragm chamber 41, while at the same time opening pipe I8 and diaphragm chamber 64 to atmosphere. sulting release of fluid under pressure from diaphragm chamber 64 will relieve the pressurer of lever B9 on the spring seat 55, while the fluid pressure supplied to diaphragm chamber 41 will deflect the diaphragm 46 in the direction of the non-pressure chamber 48. tion of diaphragm 41 will merely act through spring 55a to move the spring seat 55 to the position in whichthe portion 6| contacts the casing and further deflection will then compress the spring 55a and the diaphragm will continue to.

deflect until the force of said spring counter-balances the force incident to pressure of fluid provided in chamber 41.

'I'his deection of diaphragm 46 will act through rod 49 to operate the lever 51. to pull the fuel control lever 2 out of its fuel cutoff or stop position and through its idle position to a position corresponding to the pressure of fluid provided in chamber 41, whereupon fuel will be supplied to the engine to permit starting and running thereof. With this structure it should be noted that fuel will not be supplied to the engine upon movement of lever 35 from its stop position to itsidle position since in idle position no fluid under pressure will be provided in diaphragm chamber 41 as required to actuate the diaphragm 46 for moving the fuel control arm 2 out of its fuel cutoff or stop position to a position for supplying fuel. In other words, it is necessary to provide a certain pressure of fluid in diaphragm chamber 41 upon release of fluid from chamber 64 to obtain fuel to provide for starting and running of the engine.

After the engine has been started and is vrunning on fuel, the speed of the engine may be reduced to idling, if desired, by moving the operator s control lever 35 to its idle position which will effect a complete release of fluid under pressure from chamber 41. The spring 55a will then act to move the diaphragm 46 in the direction of the pressure chamber 41 and such movement transmitted through rod 49 and lever 51 will move the full control lever 2 in the direction of its idle position. This movement will continue until the fuel control arm obtains its idle position and will then cease, since in the corresponding positio-n of diaphragm 46 and with the portion 6| on the spring seat 55 in contact with the casing, the spring 55a will have expanded to its free height and no longer exert force against the diaphragm.

Should the operator now desire to accelerate the engine, he will move lever 35 out of idle position in the direction of fuel speed position and thus provide fluid under pressure in diaphragm chamber 41. The diaphragm 46 will then deflect, against the opposing pressure of spring 55a, to a position corresponding to the pressure of fluid acting in chamber 41, and this movement will pull the fuel control lever 2 to a corresponding position to provide the desired increase in speed or power output of the engine. Adjustment of the lower 35 to any position between idle and full speed will provide a corresponding speed or degree of power output, as Will be apparent.

If the operator desires to stop the engine he will move the lever 35 to its stop position for opening chamber 41 to the atmosphere and for supplying fluid under pressure to chamber E4 to deect diaphragm 63 and thereby actuate lever 69 to push the spring seat 55 into the casing until the nut 62 engages the casing, and this movement Initially, this deflec- The re-' of said seat will act'throughv spring 55a to move the diaphragm 4tY to the position in lwhich it is shown in the drawing. This movement of diaphragm 46 will in turn operatethe lever 51 to push the fuel control arm 2 to its stop position for cutting off the supply of fuel to the engine whereupon the engine will stop.

As in the structure shown in Fig, 1 of the drawing, it will now be seen that with the structure shown in'Fig. 2, a failure of the supply of fluid under pressure with theengine running can not result instopping of the engine, but due to the loss of uid under pressure from diaphragm chamber 41 can only result in operation of the structure to reduce the speed of the engine to idling. Stopping of the engine requires fluid under pressure. Thusin case of loss of fluid under pressure the engine will continue to operate and its speed may be controlled by conventional auX- iliary or hand operated means usually associated with engines of this type,

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A fluid pressure control apparatus for selectively moving a control element toeither a rst position or a second position or out of said second position ina direction away from said first position comprising in combination, first and second relatively movable members in said casing means subject to pressure .of fluid in, respectively, first and second chambers, control means selectively operable to eifect a supply of fluid under pressure to either one of said chambers and to at the same time open the other one of said chambers to atmosphere to release fluid under pressure therefrom, said control means being also opera-ble to open both of said chambers to atmosphere at the same time, mechanism operatively connecting said movable members to said control element, and spring means acting on said mechanism and operable, when both of said chambers are open to atmosphere, to effect operation of said mechanism to move said control element to said second position, said first movable member being operable in response to pressure of fluid supplied to said first chamber to effect operation of said mechanism to move said control element to said rst position, and said secondmovable member being operable in response to pressure of fluid supplied to said second chamber to move said control element out of said second position in a direction away from said first position.

2. A fluid pressure control apparatus for selectively moving a control element to either a first position or to a second position or out of said second position in a direction away from said first position comprising in combination, casing means, first and second relatively movable members in said casing means subject to pressure of fluid in, respectively, first and second chambers in said casing means, a control spring in said casing means, acting on said rst movable member in op* position to pressure of fluid in said first chamber, a regulating spring in said casing means acting on said second movable member in opposition to pressure of fluid in said second chamber, a lever have ing one end connected to said rst movable member, means arranged to connect the opposite end of said lever to said control element, means operl atively connecting said second movable member to said lever lat a point intermediate the ends thereof, control means selectively oper-able to effect a supply of uid under pressure to either one of saidV chambers and to at the same time open the other one of said chambers to atmosphere to release fluid under pressure therefrom, said control means being also operablevto open both of said chambers to atmosphere at the same time, said rst movable member beingmovable against said control spring, in response to supply of fluid under pressure to said first chamber, to actuate said lever to move said control element to said rst position and being movable by said control spring upon opening said first chamber to atmosphere to actuate said lever to move said control element to said second position when said second chamber is also open to atmosphere, and said second movable member being adjustable against said regulating spring in response to fluid under pressuresupplied to said second chamber to actuate said lever to adjust said Control element out of said second position in a direction away from saidrst position.

3. A fluid pressure control apparatus for seleck chambersand at the same time to open the other one of said chambers to atmosphere to release iluid under pressure therefrom, said control means being also operableto open both of said chambers -to atmosphere at the same time, a spring in'sad casing means acting on said second movable member in opposition to pressure of fluid in 'said second chamber, mechanism connecting said rst member to said spring and operable by said rst member in response to supply of fluid under pressure to said first chamber to effect operation of said spring to move said second member to one position, said rst movable member being operable uponvreleas'e of iluid under pressure fromsaid iirst chamber to provide for said springbecoming ineffective on said second member in a different position of said second member,V said second member ybeing adjustable out of said different position in a direction away from said one position in response to supply of fluid under pressure to said second chamber, and mechyanism connecting said second member to said control element and operable to adjust said control element in accordance with the position of said second member. f

ROY R. STEVENS.

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