Патент USA US2412360код для вставки
Dec. 10, ¿1946. C. F. SCHORN ' 2,412,360 POWER CONTROL Filed March l4, 1942 2 Sheets-Sheet v.1 76 /64 f77” Dec. .10, 1946. c. ' F. scHoRN 2,412,360 A Pow'ER CONTROL _ Filed March 4, 1942 2 Sheets-Sheet 2 2,412,360 Patente'd Dec. 10, 1946 UNITED STATES PATENT OFFICE 2,412,360 POWER CONTROL Carl F. Schorn, Detroit, Mich., assigner to George ' M. Holley and Earl Holley Application March 4, i942,V serial No. 433,371 4 Claims. ( Cl. 170-135.6) 1 2 , This invention relates to the control of a vari I1 and ultimately engaging with a stop 14 l0 able pitch propeller driven by an airplane engine in which the pitch is automatically adjusted to keep the engine at any desired speed. The object of this invention is to improve the cated in a rotating arm 15. A cam face 2l on the weight I5 engages with the roller I8 mounted on the rotating element I9. existing power controls so that a manually op erated lever will select the speed of the engine desired and that this speed Will automatically select the manifold air pressure desirable at that speed. The product of revolutions per minute and manifold air pressure is roughly proportional to indicated horsepower. Another object of this invention is to avoid the need for the use of broken links so that straight through pull and push links can be used. As a result, the control unit can be bench-tested, as it is a self -contained unit. Other objects are to facilitate the operation of the device when cold and to provide means to render the device inoperative when idling the engine, and in both circumstances, to permit the manual operation of the throttle. The reason manual operation is necessary at low speed, es pecially at idling speeds, is that the centrifugal control of the variable pitch propeller is in op eration at low speed. In the drawings: Fig. l shows the general elevation of the mech anism. A light spring 2li causes the roller I8 to be held in contact with the cam face 2 I. By this means, as the weight I5 rotates clockwise, the roller I8 is moved to the left the desired amount, thus compressing thespring 28 and sliding a shaft 23 to the left which engages with a number of baro metric elements 23, which are located in a cham ber 24 which is in communication through a pipe 25‘with the pressure on the engine side of a throttle 61 in an air entrance 19. The pressure in the chamber 24 is usually described as at manifold air pressure (see Fig. l). The reason for this is that a supercharger is generally used, in which case this connection 25 is on the engine side of the >supercharger (not shown) which is usually located just before the inlet valve air entrance to the engine cylinder. To simplify the disclosure the supercharger is not shown. The barometric element 23 engages on the right with the sliding shaft 22 and on the left with a servo motor valve 216 which, in its turn, engages with a compression spring 34, which takes up the back lash between the valve 26 and the barometric element 23 and the sliding shaft 22. 'I'he gover nor characteristics are controlled by the spring 30 I 1 slightly modified by the springs 20v and 34. Fig. 2 shows a plan view of part of the control The movement to the left of the valve 26 mechanism. causes a piston 21 to move to the right in the Fig. 3 shows in cross sectional elevation the cylinder 28. Oil under pressure is admitted to combined centrifugal and barometric controls. the servomotor through the pipe 53 and when Fig. 4 shows a plan View of the manually op 35 the valve 26 is moved to the left, as it is when erated lever and the links connected to it. there is a decrease of pressure in the chamber Y Fig. 5 shows the normal relation between revo 24, oil flows down a passage 54 and pushes this lutions per minute and manifold air pressure, piston 21 to the right. The oil at the right of the and also the relation for best economy. piston 21 then escapes through a passage 55 In Fig. 1 a speed control lever 36 slidabli7 en~ 40 through the valve 26 to an o-il outlet 56. gaging with a quadrant 39 controls the pitch A rod 51 is pivoted to the guide 58 which is of a propeller 81 through alink 49, rack and connected to a piston rod 59 mounted on the pinion 16, centrifugal governor 11, a hydraulic piston 21. The rod 51 is connected to a link 58 pitch-changing device 18, 19, 80. This device mounted on a bracket 52 (Fig. 2). The link 58 forms no part of this invention and is a well 45 is formed in the shape of a crank and is con known device in general use for several years. nected to a link 50 (Fig. 2). The link 60 is con A cam I0 provides a control to change the datum nected to the throttle arm 6I (Fig. 1) through a of the centrifugal mechanism to obtain better economy curves. This is shown in Fig. 3 where its rotation causes a sleeve II to slide in a bear ing I2. 'I’he sleeve I I ' carries a rotating shaft l I3 driventhrough a slot I4 at a speed in propor tion to the speed of the engine. Governor weights pin 62 on the end of which is a ball'63. ' The ball 63 slides in a slot in the element 54. 'I‘his ele 50 ment 54 is connected to the rod 41 which is piv otally mounted on the control lever 36. lA lever 65 is mounted on a pivot 6E, which pivot is mount-` ed on this main speed control lever 35. This lever carries a link 48 which slides inside the ele I5, one of which is shown pivoted at I6, rotate clockwise at high speed compressing the spring 55 ment 64. Arounded end 68 of the link 48 en 2,412,360 3 4 gages with the ball 63 when the lever 65 is rotated anti-clockwise and the ball 63 then engages with a movable stop 69 which, when moved to the right, compresses a spring 1E), manually closing the throttle 61 by means of a throttle lever 6I. A rod 43 is pivotally connected to the lever 65 tween the revolutions per minute of the engine and manifold air pressure for bestv economy, that is, the relation whichY exists when cruising lean and running the Vengine slower and opening the and this rod 43 carries a roller 38 which engages with a surface êû of the quadrant 39. When the throttle wider than with the normal curve. When the cam I6 is rotated anti-clockwise, the manifold pressure follows the curve of better economy. The curve to the right shows the nor-v roller 38 engages with an inclined surface 4I and rides on a surface 42, the lever 65 is rotated. The order to free the device from the servo-v shown in the drawings, motor and prevent interference with the above ~ sumes as a rule. mal -curve with the cam liìin the position as The slowe-ran engine runs at any given power, the less fuel it con mentioned manual means for closing the throttle, The‘adjustable stop it, Fig. 3, which is mount a by-pass valve 29 is provided which gives a free ' ed on the rod varm 15 limits the maximum re opening 35 between the passages 54 and 55 when sponse toA speed of the 1centrifugal weightV lever this Valve is rotated anti-clockwise about 45° ' l5, so‘as to limit the maximum boost pressure. Otherwise, during a. dive an excessivey boost pres (Fig. 3) . ¿In the position shown, which is the op erative position, a small opening 3| causes the device to function as described above, but per mits a circulation of a small quantity of oil at all times in addition to that which leaks around the sure would be possible. Points E and F (Fig. 5) represent the maximum boost pressures con trolled by the adjustable stop 11i and the movable cam i6. The point 1E corresponds to înraximiim piston 2l. A by-passpassage 32 -connects the boost pressure with a normal Ycurve with the passage 54 with the valve 29 and a by-pass 35i cam l@ in positionshown and the point F to the connects the passage 55u/'ith the valve 29. maximum 'boost pressure with the maximum A rod 46 is pivotally connected to- the lever 65 25 economy curve with camV l@ rotated counter at the point which is normally located opposite a pivot 6i on which the lever 36 is’mounted and clockwise. The inclined Vsurface 41 (Fig. 1') ' may be mount rotated (Fig. Äl). Hence, rotation of the lever ed on a slidable element 84 held on the quadrant 36 does'notnormally move the- link d6. The link ` se'by studs es and ae. The holes in the quad é‘ßïtravels with the link 4l' and at a slightly faster 30 rant 3Q may be -slotted so that the exact location rate than vthe link d'7, and hence slightly faster of the inclined surface ¿il> maybe adjusted. than‘the element ‘64. The link £6 is connected Operation , with the lever 62 to the valve 29. Hence, when ever the 'roller 38 >rides on the surface 42 and Yis depressed, the valve 29 rotates anti-clockwise and the servomotorZE, 21, 59, 56, 51 is rendered in operative. ~At the same time the rounded end 68 engages with the ball ‘63 and the throttle 6l is thus closed manually. In order to permit this servomotor to be ren dered inoperative at any time and not merely whenthe lever 36 is rotated anti-‘clockwise into the position for minimum speed, a handle 35 on the throttle lever 35 is made so that >it can be ‘depressed and'when itis depressed, it'slides inside `When the speed'control lever" 36 ¿is -moved counterclockwise, the roller 38 rotates'on thefsur iace 46 >down the inclined Ysurface fêlìandalong the surface 132. When the ’throttle lever'361is moved in 'the anti-clockwise direction (Fig. ~51), that is to say, in the idling position, .the `rod f4!! moves to the right and engages with Vthe v.ball end’63 and closes the throttle lever'âi, causing the throttle 6l to close. v'In OtherÍWordS, the 4con trol ceases to'be auto-matic. The `~end oi ith'e >rod '48 is provided vwith the element " ‘6% which is ' rounded to permit freedom of Vmoti-on in the "hol a cylinder ‘l2 integral with-the lever 36, com low element 64. When the control-lever Sâlis'in pressing a spring 13 and carrying with it the its low speed position, the end V68y kengages with rod 43 and the roller -38. In order that the handle the ball`63 which, in its turn, engageswith'the 35 can rotate without rotating the rod d3, a ball sliding element 69 and compresses the spring lil. joint isprovided-on the end of the rod d3. In 50 The throttle llever '6I isfthus moved anti-clock order-vthat-the handle 35 can be locked in the wise and the throttle 61 is closed manually. depressedV position, a pin 59] is provided in the As the lever 65 is rotated counter-clockwiseby `handle and an L-shaped slot 5i in the cylinder the depression of the -rod 43, it carries over to 12 is also provided. Hence, when the handle S5 ie left the link 4`6which causes the lever 582 to isldepressed compressing the» spring 73, the pin rotate anti-clockwise and thus moves withit‘the 5D is lowered to the level of the horizontalleg valve 29 inthe anti-clockwise direction, vwhich of the L-shaped’slot 5|.y The handle 35 is then as described above,»places the passage y303 (Fig. 3) rotated anti-clockwise 'looking` down and the pin in a positionto allow free communication on both 5€! iscarried over to the rightinside the L-shaped »sides of the piston 2l'. The servomotor thus'be slot 5I. The roller 38 is thus locked in the lower 60 comes inoperative during theidling position and Y position and the valve 29 is thus moved to permit hence no unusual eiiort is required'to close the free circulation between the sides of the piston throttle vâì'ito theidling position. 2l. Hence, under this condition, the speed con >Let us assume that’the engine isrun'ning Vat trol Vlever 36 becomes an ordinary Ithrottle con 1500 revolutions per minute 'and manifold «air trol lever, that is, it can be used to open the pressure corresponding tothe point A on the'nor throttle further than the position selected by mal curve oiFig. 5. vLet vus assume further that centrifugaly governor so that extra power is avail the throttle 67 is to Vbe openedgThisfis accom able Vif'the automatic mechanism fails. plished as follows: , ' ' g ' y Fig. 5 shows the relation between the revolu- _ The speed control lever 36 is. moved in the tions per minute and the manifold air pressure clockwise direction. The link'ßg 'acts'on the pro'- j measured in inches of mercury. As the revolu peller pitch gear 'Tl-8u, Immediately the'rev'o ktionsîper minute increase, the permissible mani lutions per minute would increaseandthemani fold pressure increases. Hence,any increase in fold air pressure would fall to the point B, be~ speed calls for an increase _in‘manifold pressure. cause the element 69 `wouldnot immediately en gage' the ball'63. The lowered manifold air pres > V-The curve to the left shows the relation be 2,412,360 5 6 sure is due to the increased air iiow at a given throttle and the fall in pressure causes the ele ment 23 to expand. As a result, the valve 26 is of the engine by varying the pitch of the propel moved to the left, thereby admitting oil pressure from the line 53 to the passage '54. The piston 21 then moves to the right carrying with it the rod 57. rThe rod il@ moves to the left carrying With it the pin 53 which moves the throttle lever ler, a throttle lever, an automatic controlling de vice therefor comprising a second engine-driven centrifugal governor, a barometric device opera i) tively connected to said second centrifugal gov ernor and slidably mounted so that it is moved bodily thereby, a variable pressure chamber en closing said barometric device and connected to 6| clockwise, opening the throttle 61 and raising the air inlet so as to be maintained at the pres the manifold air pressure in 30 and hence in pipe 10 sure of the air entering the engine, a source of 25 and in the chamber 2li, to the point C, which iiuid under pressure, a servomotor valve opera would also be located on the normal curve. tively connected to the barometric device and to Meanwhile, the governor il maintains the speed >the second governor so constructed and arranged of the propeller constant at the speed determined that it controls the now of said fluid under pres by the position of the lever 30. sure, a servomotor operatively associated with If this point C is not on the desired normal said servomotor valveand adapted to be operated curve, it is corrected by changing the contour of by said fluid under pressure and by said servo the cam surface 2i. When the cam l0 is moved motor valve, a link connection from said servo to the left counter-clockwise and the sleeve il motor to said throttle lever adapted to move the moves to the left at any given speed, the capsule so throttle so as to maintain the pressure in the air 23 is translated to the left, carrying With it the entrance to the engine at the pressure required to valve 2S, compressing the spring 34. Oil pressure move the servomotor valve into its neutral posi then ilows down the pipe 53, passage 54, the pis tion. ton 21 moves to the right, the link 60 moves to 2. A device as set forth in claim 1 in which >the left carrying With it the ball 53. The throttle there is a casing supporting said automatic mech anism and in which second centrifugal governor 51 is then moved towards the wide open throttle position, but the link 49 is not moved and there fore, the revolutions per minute of the engine is slidably mounted with respect to said casing, means for sliding the second centrifugal gover remain stationary and therefore, the point C nor, the pressure responsive device and the servo moves up to point D. The point D is vertically 30 motor valve laterally so as to vary the pressure above the point C because the speed is constant automatically maintained in the air entrance to and the distance C-D corresponds to the dis the engine with each speed of the engine. tance between the tvvo curves, the better economy 3. A device as set forth in claim 1 in which curve and the normal curve. The capsule re there are additional valve means so located that sponds to changing pressures virtually on a 35 when open it renders the servomotor inoperative, straight line; hence the cam l0 need be calibrated manually controlled mechanism for said valve for only tvvo positions. mounted on said manually operated control de The probable relationship is that point A cor vice and so constructed and arranged as to be responds to 23" mercury at 1500 R. P. M.; point operated at vany position of said control device, B corresponds to 22" mercury at 1700 R. P. M.; 40 a yieldable link connecting the throttle with the point C corresponds to 26” mercury at 1700 manually operated device and adapted to man R. P. M.; point D corresponds to 29" mercury at ually control the throttle lever when said servo 1700 R. P. M.; point E corresponds to 40" mer motor is inoperative, cury at 2350 R. P. M.; and point F corresponds to 4. A device as set forth in claim 1 in which 45” mercury at 2350 R. P. M. there are additional valve means so located that What I claim is: when open it renders the servomotor inoperative, 1. In combination With an internal combustion a link connected to said valve and to said man engine having an air entrance and a throttle ually operated control device, a second link also valve therein adapted to control the air ñoW to connected to said manually operated device and the air inlet of the engine, a variable pitch pro 50 so constructed and arranged as to push the throt peller driven by said engine and an engine-driven, tle lever into the closed position when the man variable speed centrifugal governor for control ually operated control device is set in the posi ling the engine speed by varying the pitch of said’ tion of minimum speed of the engine so that the propeller, a manually operated control device for throttle may be easily closed Whenever the auto said governor and connected to the variable speed 55 matic throttle control device is disconnected. means of said governor so as to control the speed CARL F. SCHORN.