US2416982A - Engine shaft actuated locomotive valve gear of the suspended eccentric rod type - Google Patents

Description

2,4 16,982 E GEAR S. D. DEKLE March 4, 1941.

ENGINE SHAFT ACTUATED LOCOMOTIVE VALV OF THE SUSPENDED ECCENTBIC ROD TYPE Filed May 10. 1944 4 Sheets-Sheet l INVENTOR SWW/afl. E/rzf.

@La ATTORNEY March 4, 1947. 5, D, DEKLE 2,416,982

ENGINE SHAFT ACTUATED LocoMo'rIvE VALVE GEAR 0F THE SUSPENDED ECCENTRIG Non TYPE Filed. May 10. 1944 4 Sheets-Sheet 2 Z 4 6' 8 M Il( 75 zu una /a arroz/vf' Y March 4, 1947. s. D. DEKLE 2,416,982

ENGINE SHAFT ACTUATED LCOMTIVE VALVE GEAR OF THE SUSPENDED ECCENTRIC ROD TYPE Filed May 10, 1944 4 Sheets-Sheet 3 J5 M fhtw/wea y 17 PVs/rfa l Fu rvr/:vn fg .56 7

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INVENTOR.

March 4, 1947. s, D, DEKLE 2,416,982

ENGINE SHAFT ACTUATED LOCOMOTIVE VALVE GEAR 0F THE SUSPENDED ECCENTRIG ROD TYPE Filed May 10, 1944 4 Sheets-Sheet 4 r2' VERSE M mi Patented Mar. 4,4 1947 UNITED STATES PATENT OFFICE ENGINE SHAFT ACTUATED LOCOMOTIVE VALVE GEAR OF THE SUSPENDED 11 Claims. 1

This invention relates to valve gears and, more particularly, to such for operating a locomotive.

The principal object of my invention, generally considered. is to provide a steam-engine valve gear of improved construction and operation.

Another object of my invention is to provide a valve gear which requires only a small amount of lap to obtain perfect valve events, as compared to the larger valve laps of other types of gear, thereby cutting down excessive wearing of valves and bushings, especially when in running cut-oil.

A further object of my invention is to provide a valve gear that gives a greater amount of starting `power when obtaining full valve travel by quickly opening the steam port at the beginning of the piston stroke and delaying closing of the exhaust port when the piston is nearing completion of its stroke.

A still further object of my invention is to pro- 'vide a valve gear in which the wearing points are greatly reduced, as. by the elimination of combination levers and union links.

An additional object of my invention is to provide a light-weight gear which is readily accessible and which is provided with a self-aligning bushing in the back end of the combination eccentric blade, thereby eliminating side stress and strain to the blade. due to lateral motion in the driving wheels.

Another object of the valve gear is to satisfactorily allow for the fall and rise of the engine frame when going around curves, by making the valve gear eccentric rod ratio large, that is, sixteen to one.

Other objects and advantages of the invention, relating to the particular arrangement and construction of various parts, will become apparent as the description proceeds.

Referring to the drawing illustrating my invention,

Figure l is a Side elevation of the forward parts of the running gear of a steam locomotive, including one embodiment of my improved valve gear.

Figure 2 is a fragmentary plan of the gear and associated parts shown in Figure 1.

Figure 3 is a vertical sectional view on the line III- III of Figure l, in the direction of the arrows, the gear, however, being shown in neutral position, as illustrated diagrammatically in Figure 8.

Figure 4 is a diagrammatic illustration of the gear when the reversing mechanism is in full driver I2.

2 forward position and the main crank in its forward dead center position.

Figure 5 is a View corresponding to Figure 4, but showing the positions of the parts when the main driver has turned 90 in moving forward.

Figure 6 is a view corresponding to Figure 5, but showing the positions of the parts when said driver has turned another 90 forward.

Figure is a view corresponding to Figure 6, hut showing the positions of the parts when the driver has turned still another 90 in moving forward.

Figure 8 is a diagrammatic illustration of the gear when the reversing mechanism is in neutral or running cutoi position, the full line positions of the gear otherwise corresponding with Figure 7, and the dotted line positions attempting to show the positions of the parts when the main driver is in the angular positions represented by Figures 4, 5 and 6.

Figure 9 is a view corresponding to Figure 8, but showing the positions of the parts when the reverse mechanism is positioned for full travel reverse operation.

Figure 10 is a valve ellipse or displacement curve for a valve gear embodying my invention.

Referring to the drawings in detail, like parts being designated by like reference characters, and first considering Figures 1, 2 and 3, it will be seen that I have illustrated one embodiment of my invention as applied to a steam locomotive having on each side, only one of which is i1- lustrated, a forward driving wheel I I and a main driving wheel I2. Said wheels are journaled with respect to a locomotive frame I3 carrying a cylinder I4 with a steam chest I5. In the cylinder reciprocates a driving piston I6 and in the steam chest is a piston valve Il, illustrated only in the diagrammatic views of Figures 4 to 9 inclusive.

The piston I6 has a rod I 8 connected to a cross head I9 slidable on a guide 2| and to which is pivoted a connecting rod 22, the other end of which is pivoted to the main crank pin 23 of the An eccentric crank 24 is attached to a preferably axial extension 25 on` the main crank pin 23 and preferably set so that its free end trails the movement of the main crank pin 90 when the drivers are moving forward.

To the free end of the eccentric crank is pivoted the eccentric rod or blade 26, the forward or free end of which is, in turn, pivotally carried by radius arms 21 and 28. The upper ends of the radius arms are connected to intermediate portions of a reversing member or yoke 29, as by pivot pins 3| and 32, respectively, as shown most clearly in Figure 3.

The reverse yoke 29 is part of the reversing mechanism for the gear. Its upper portion is bifurcated to straddle the forward end of a reach rod 33 and it is connected thereto by pivot pin 34.

The lower portion of the yoke 29 is also bifurcated and straddies a link block 35 which is slidable in an arcuate link or segment 35, said block being connected to the yoke 29 by a pivot pin 31. The link 36 is mounted on the top of a gear frame 39, in turn carried by the main locomotive frame I3. The lower bifurcated portions of the yoke 29 are each, in turn, bifurcated and straddle outer and inner elements 39 and 4I of the frame 38, and their lower ends carry generally rectangular blocks 42 and 43 by means of pivot pins 44 and 45, said blocks being adapted to reciprocate vertically with respect to said frame 38 as the yoke is moved by the reach rod 33.

The rise and fall of the lower ends of the reverse yoke is accounted for by the fact that the link slot 46 in which the block 35 moves has a radius of curvature (in the embodiment illustrated 3714") which is longer than the distance between the block 35 and the line passing through the axes of the pivot pins 44 and 45 (in the embodiment illustrated 26") This reciprocation movement is provided to insure the desired sequence of valve events. In the embodiment illustrated these blocks reciprocate of an inch, thereby allowing the reverse yoke to give the correct radius through the radius arms to the front end of the eccentric rod or blade.

The gear frame 38 also carries a bell crank 41 comprising an elongated hub portion 48 mounted between the elements 39 and 4I of the gear frame 38 as on pivot pin 49. From the hub 48 projects an arm i in a generally forward, horizontal direction and the forward end of which is straddled by a transmission link 52 to which it is connected as by means of pivot'pin 53.

The lower end of the transmission link is also bifurcated and straddles a portion of the eccentric rod 26 intermediate the ends but near the connection with the radius arms 21 and 28, being connected thereto as by means of pivot pin 54.

The other bell crank arm 55 depends from the hub 43 and is desirably bifurcated, straddles, and is connected to the rear end of, a valve rod 56, as by pivot pin 51. The front end of the valve rod is connected to the valve cross head and valve stem 53 by means of pivot pin 59.

The reverse yoke 29 is operated to vary the cutoff provided by the gear and for the reversal of the direction of travel, as desired, by the reach rod 33, the rear end of which is connected to the outer crank 6I of a reversing shaft 62, as by means of pivot pin 63, and the inner crank 64 of which is connected to the front end of reversing shaft 65, as by pivot pin 66. The reversing shaft is, in turn, manually operable as by means of reversing lever 61 to which it is connected, as by means of pivot pin 68.

Referring now to the diagrammatic representation in Figure 4, it will be seen that, when the piston I6 is in forward dead-center position, the rear end of the eccentric rod 26 is disposed 90 behind the crank-connected end of the rod 22 so that, when the reversing mechanism is in the forward corner, as illustrated in Figure 1, the valve I1 is just starting to admit steam, represented by the arrow 69 in Figure 4, from the live steam compartment 16 of the chest I5 through port 1| in front of the piston I6, the rear portion of said valve I1 having opened port I2 to exhaust and so as to avoid back pressure. This position corresponds with the point 13 on the valve ellipse of Figure 10.

Figure 5 shows the relative positions of the valve gear parts when the drive wheel I2 has moved forward through an angle of During this movement the piston I6 has moved approximately half of its stroke or to a point designated by the reference character 14 in Figure 10. At the same time, the valve as shown has completely opened the port 1I and is starting to close it. In other words, the valve, during this 90 movement, has advanced from a slight opening of the steam port to beyond the full opening thereof.

Figure 6 shows the position of the parts while the locomotive is moving forward, but with the crank in rear dead-center position. During this movement from Figure 5 to Figure 6 cut-off has occurred, as designated by the reference character 15 in Figure 10, followed by release, designated by reference character 16 in Figure 10, upon opening cf the port 1I to the exhaust chamber 11. Figure 6, therefore, corresponds with Figure 4, except that steam, represented by the arrow 18. is here just being admitted to the rear of the piston I6, with the forward end of the cylinder open to exhaust, the point on Figure 10 corresponding with this position being designated by the reference character 19.

Figure '7 shows Vthe succeeding position of the mechanism in which the driver I2 has turned through another 90 in a forward direction, in which position the port 12 is fully open to admit steam back of the piston i6, exhaust taking place through port 1I to exhaust chamber 'I1 in front of said piston, corresponding generally with position 8| on the valve ellipse diagram of Figure 10. It will therefore be seen that Figure 7 corresponds with Figure 5, except thatthe directions of motion of the valve and piston are reversed and the position of `the valve is at approximately the opposite end of the valve chamber.

Figure 8 combines the positions of Figures 4 to '7, inclusive, for the gear when the reverse mechanism is in neutral or what might be designated as running cut-off position, that is, with the gear set for minimum steam consumption or earliest possible cut-oit. This is represented by the thinnest ellipse, marked 82, in the diagram of Figure l0, the point 13 on said ellipse corresponding with thesetting when the rear end of the eccentric `rod is positioned at 93 in forward travel. The point B4 on said ellipse 82 shows the cut-off which in the embodiment illustrated is at about 44.2% of the stroke. When the driver moves through 90 to place the rear end of the eccentric rod at point 85, the position of thegear in Figure 10 is represented at 86 or during the expansion of the steam aftercut-oi. The next point 81, representing the position of the rear end of the eccentric rod after another movement of 90, is shown in Figure l0 by the reference character 19, and the full line position of the gear is represented on Figure lll-by the reference character 86.

Figure 9 corresponds with Figure 8, except that the positions of the parts are shown for full reverse motion. Reference character 9 shows the position of the rear end of the eccentric rod when the mechanism is otherwise as in Figure '1, and the characters 9|, 92 and 93, respectively, show the positions of the rear end of the eccentric rod when the mechanism is otherwise as in Figures 6. 5 and 4.

The points on Figure on the rearward motion valve ellipse 94 which correspond, respectively, with points 9|, 92, 93 and 89 are 19, 95, 13 and 96.

From the foregoing disclosure, it will be seen that I have provided a valve gear which operates solely from a single connection with the main crank pin, the adjustment of the cut-ofi" and reversal thereof being accomplished by a yoke mounted on a frame and carrying the front end of the eccentric rod on radius arms, pivot friction being thereby substituted, in almost all instances, by sliding friction, and all parts of the gear being conveniently accessible for lubrication and maintenance.

The valve ellipse illustrated in Figure 10 shows that the events of port opening, cut-off, release and compression occur when the valve is relatively remote from its dead center and, therefore, moving at relatively great speed. This means that these events occur quite quickly, thereby improving the power output of the locomotive by promptly admitting steam to the cyllnder and cutting it off without appreciable Wire drawing.

A consideration of Figure 1D will also show that the valve ellipses are substantially symmetrical, particularly for forward travel, that great economy in the use of steam may be accomplished in running cut-off and positions adjacent thereto, and all of these advantages are obtained when using a very small lap, which, in the embodiment illustrated, is 3A of an inch, the exhaust lap being negative, that is, amounting to a clearance of 3/m of an inch.

The following table shows various features of one embodiment of my gear, having 28" cylinders, 7/32" lead, and 65/3H valve travel when moving forward:

connection therewith. Thus the fall and rise of the engine frame when going around curves is satisfactorily allowed for, as when the reverse yoke is positoned for full forward or reverse travel, the ratio in relation to the main crank pin is approximately 16:1. In other words, a vertical movement of the frame of even as much as one inch with respect to the Wheels, as upon rounding a curve, involves a relative movement of the transmission link 52 of only about 11g inch, so that the corresponding valve movement is minimized, as contrasted with that in the Brown Patent No. 1,076,406, for example, in which the ratio is apparently less than 7:1.

Although preferred embodiment of my invention has been disclosed, it will be understood that modifications may be made within the spirit and scope of the appended claims.

I claim:

l. In a steam-engine valve gear, in combination with a frame, a. main crank pin and a valve, an eccentric rod, one end of which is pivoted with respect to a point substantially 90 out of phase, but movable with said crank pin, reversing mechanism to which the other end of said rod is pivoted to cause it to swing in an arc about a center determined by the setting of said mechanism, said mechanism comprising a reverse yoke carrying a block slidable in a link fixed to the top of said frame, said yoke having normally depending end portions carrying blocks vertically reciprocable in said frame, radius arms the upper ends of which are pivotally carried by intermediate portions of said yoke and the lower ends of which are pivotally connected to the free end of said eccentric rod, a bell crank lever pivoted to said frame, a transmission link connecting one arm of said lever to an intermediate portion of said eccentric rod, and a valve rod con- The above data were obtained with a gear having 28" stroke, l2" eccentric crank radius, and 37%" link radius. The length between end pivots of the gear parts were: eccentric rod. 79%"; transmission link, 325%@ arm of bell crank to which connected, 81/ valve rod, 6335"; arm of bell crank to which connected, 11%'2 radius arms, 32"; reverse yoke, S31/21; distance from radius arms connecting points: (l) to link block, 10"; (2) to yoke blocks, 16",

The distance on the eccentric rod between the points of connection with the transmission link and with the radius arms was 4%". This means that said distance is about, but less than, 11g of the distance from the transmission link connecco necting another arm of said lever to said valve,

to operate the latter.

2. In a steam-engine valve gear, in combination with a gear frame, a main crank pin and a valve, an eccentric crank secured to said pin and with its free end trailing it 90 in forward motion, an eccentric rod, one end of which is pivoted to said free crank end, reversing mechanism comprising an arcuate link fixed to said frame, a reversing member, a block carried thereby and slidable in said link, means for moving said member, a link movably supporting the other end of said rod from a part of said reversing member below said block, a bell crank lever, pivoted to said frame, a transmission link contion with the eccentric rod to the eccentric crank necting one arm of said lever to an intermediate portion of said eccentric rod, and a valve rod connecting another arm of said lever to said valve, to operate the latter.

3. In a steam-engine valve gear, in combination with a frame, a main crank pin and a valve, an eccentric rod, one end of which is pivoted with respect to a point substantially 90 out of phase but movable with said crank pin, a reverse yoke, a, link fixed to the top of said frame, a block car ried by said yoke and slidable in said link, said yoke having normally depending end portions carrying blocks vertically rcciprocable in said frame, radius arms, the upper ends of which are pivotally carried by intermediate portions of said yoke and the lower ends of which are pivotally connected to the free end of said eccentric rod, a bell crank lever pivcted to said frame, a transmission link connecting one end of said lever to an intermediate portion of said eccentric rod, and a valve rod connecting another arm ci said lever to said valve, to operate the latter.

4. In a steam-locomotive valve gear, in corn bination with a frame, a main crank pin and a valve, an eccentric rod, one end of which is pivoted with respect `to a point substantially 90 out of phase, but movable with said crank pin, a reversing member having a lower end portion movably connected to said frame, and an upper end portion, operating means connected to said upper end portion, link means connecting the other end of said rod to said member intermediate said upper and lower end portions, a bell crank lever pivoted to said frame, with one arm extending substantially horizontaal and another arm depending therebelow, a transmission link connecting the substantially horizontal arm of said lever to an intermediate portion of said eccentric rod, and a valve rod connecting the depending arm of said lever to said valve, to operate the latter, `the point of connection of the transmission link to the eccentric rod being close to the point of suspension of said rod from said reversing member link means, whereby the valve movement due to the fall and rise of the frame with respect to the main crank pin when the locomotive is going around curves is minimized and satisfactorily allowed for.

5, In a steam-engine valve in combination with a frame and a valve, valve-actuating mechanism, and reversing mechanism for said actuating mechanism comprising a yoke, a link fixed to the top of said frame, a block carried by said yoke and slidcble in said link, said yoke having normally depending and portions carrying blocks vertically reciprocable in said frame, and radius arms to said actuating mechanism, carried by intermediate portions of saitl yoke.

6. In a steam-engine valve gear, actuating mechanism for the valve comprising linkage including an eccentric rod moved solely by connection with the main crank pin and supported on a frame intermediate said pin and valve, and a reverse yoke carrying a block slidable in a link xed to the top of said frame, said yoke having normally depending end portions carrying blocks vertically reciprocabe in said frame, radius arms the upper ends ci which are pivotally carried by intermediate portions of said yoke and the lower ends of which are pivotally connected to the free end of said eccentric rod.

7. In a steam-engine valve gear, in combination with a gear frame, a main crank pin and a valve, an eccentric crank secured to said pin and with its free end trailing it 99 in forward motion, an eccentric rod, one end of which is pivoted to said free crank end, a reverse yoke carrying a block slidable in a link fixed to the top of said frame, said yoke having normally depending end portions carrying blocks vertically reciprocabie in said frame, radius arms the upper ends of which are pivotally carried by intermediate portions or said yoke and the lower ends of which are pivotally connected to the free end of said eccentric rod, a bell crank lever pivotcd to said frame and l0 with one arm extending substantially horizontal and another arm depending therebelow, a trans mission link with its lower end pivoted to said eccentric rod near its front end and its upper end pivoted to the free end of said substantially horizontal bell crank arm, and a valve rod with its rear end pivoted to the free end of said depending bell crank arm and its front end pivoted to said valve for operating it.

8. In a steam-locomotive valve gear, in combination with a frame, a main crank pin and a valve, an eccentric rod, one end of which is pivoted with respect to a point substantially 90 out of phase, ibut movable with said crank pin, a reversing member having an upper end portion to which operating means is connected, and bifurcations extending downwardiy therefrom, straddling portions of said frame, and with lower end portions movably connected `to said frame portions, links connecting portions of said member intermediate its upper and lower end portions to the other end of said rod to cause it to swing in an arc about a center determined by thc setting of said member, a bell crank lever pivoted to said frame, a transmission link connecting one arm of said lever to an intermediate portion of said eccentric rod, and a valve rod connecting another arm of said lever to said valve, to operate the latter, the point of connection of yhe transmission link to the eccentric rod being close to the point of suspension of said rod from said reversing member links, whereby the valve movement due to the fall and rise of the frame with respect to the main crank pin when the locomotive is going around curves is satisfactorily minimized and allowed for.

9. In a steam-engine valve gear, actuating mechanism for the valve comprising a frame, an arcuate link fixed to said frame, a reversing member, a block carried thereby and slidable in said linkl means for moving said member, an eccentric crank, an eccentric rod coupled thereto at one end, a link movably supporting the other end of said rod from a part of said reversing member below said carried block, and means operatively connecting an intermediate portion of said rod to said valve.

li). In a steam-engine valve gear, actuating mechanism for a valve comprising aA frame, an arcuate link fixed to said frame, a reversing member, a block carried thereby and slidablc in said link, a, portion of said member normally depending below said block being mounted to reciprocate with respect to said frame as the member oscillates, means for moving said member, an

05 eccentric crank, an eccentric rod coupled thereto at one end, means movably supporting the other end of said rod from said reversing member, and means operatively connecting an intermediate portion of said rod to said valve.

11. In a steam-engine valve gear, actuating mechanism for the valve comprising a frame, an arcuate link fixed to said frame, a reversing member, a block carried thereby and slidahle in said link, means for moving said. member, an eccentric crank, an eccentric rod coupled thereto at one end, link means movably supporting the other end of said rod from a part. of seid reversing momber beneath said Unk, a be2 crank pvoted to said frame, means connecting an intermediate pox tion of said 350d to one arm of crank, and means operatively connecting the oher arm of said cfank to said Valve.

SAMUEL D. DEKLE.

REFERENCES CITED The following reforme-251 :Jo of record 1u the le of this patent:

Number UNITED STATES PATENTS Name Date Brown Oct. 21, 1913 Snider Juy 18, 1916 Trent Oct. 13, 1931 Brown Sept, 3, 1914 Talhert, Jan. 18, 1916 Harris Mar. 22, 1927

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