US1877893A - Steam engine starting device - Google Patents

Description

Sept. 20, 1932. R. F. KNIGHT 1,377,893

STEAM ENGINE STARTING DEVICE I Filed Sept. '7, 1927 4 Sheets-Sheet 1 IN VEN TOR.

P 20, 1932- R. F. KNIGHT STEAM ENGINE STARTING DEVICE Filed Sept. 7, 1927 4 Sheet-Sheet 2 Sept. 20, 1932. R. FQKNIGHT 1,877,893

STEAM ENGINE STARTING DEVICE Filed Sept. 7, 1927 4 Sheets-Sheet 5 INVENTOR.

SepL'ZO, 1932. R. F. KNIGHT STEAM ENGINE STARTING DEVICE Filed Sept. 7. 1927 4 Sheets-Sheet 4 S I 4 5 W X we, stares PATENT. DFECE.

RONALD FRANK KNIGHT,

OF RAMSEY, NEW JERSEY STEAM ENGINE STARTING DEVICE Application filed September This invention relates to improvements in reciprocating fluidpressure engines, particularly steam locomotives, which, for reasons of economy, have a normal maximum cut-E shorter or earlier than experience shows to L be desirable for prompt and satisfactory starting. To enable such engines to start under load, itis usual to make provision for steam to be admitted after the main distributw ing valve means has cutoff, and continuing until the piston has reached a suficiently late percentage of its stroke to accomplish the desired purpose.

Anobject of this invention is to provide starting means for such engines by asystein of auxiliary steam ports controlled bysuit able valve means independent-of. the main distributing valve. The advantages possible by my proposed system include (1) The elimination of the objectionable feature of chanically putting the auxiliary ports out of action after starting, on variable cut-ofi enof action automatically when the. cut-off at the main valve is shortened'a predetermined amount, and without the employment of sep arate cut-out valves. These new and important features will permit the use of a very much earlier normal maximum cut-off than has heretofore been found practical, com-, bined with fewer moving parts and simpler. construction with all the attendant benefits, together with a more nearly perfect realiza-' tion of the possible economies. consequent upon the use of said short maximum cut-off."

Further features and advantages will'appear from the following description and claims 40 when taken in connection with the accompanying drawings. V

Figure 1 shows in more or less diagrammatic form, an embodiment of this invention in a steam engine cylinder, and the necessary operating means for same. a, b, 0 and quent positions of the valves, eccentrics and excessive pie-admission, common with the means now in use: (2) Provision for megines: (3) To so put said auxiliary ports out Figure 2, views d, shows the piston of Flg. 1 111.. various positions of 1ts stroke andthe conse-i 7,192 7. Serial No. 217,970.

.tion as it maybe applied to the cylinders of locomotives having inside. admission piston valves, operated, as is very general, by a gear 7 which is a combination of the move'ment of the piston .andof a' crank or its equivalent, operating-at a phase of 90 degrees to the main crank. Figure 4 shows, in centre line form, the positions assumed by the combination lever of Fig. 3, when the piston occupies the positions seen in Fig. 3 and the four views of Fig. 2, and indicates the corresponding relative positions of the points of connection of the main and auxiliary valves with the combinationilever.- Figure dis a section taken through 5-5 Fig. 3 minus the valves, and Figure 6 is an end view of the upper part 0 the combination lever of Fig. 3 and its connections. Fig.7 shows-in diagram form for reasons of clearness and simplicity-my device as it maybe arranged for use in conjunction with a Walschaert valve-gear and depicts the relative positions of the principal concerned parts when-the piston is at the end of its stroke. Fig.8 shows the same arrangement as Fig-7 but with the piston and valves in their relative positions when the auxiliary valve is about to admit steam to the cylinder. Fig. 9 also shows the arrangement of Fig. 7, but when the main valve is cutting off. Fig.

10 again illustrates the arrangement of Fig. 7, this time showing the piston and valves in their relative positions when the auxiliary valve is cutting off. 7 Referring now more particularly to the drawings :'Fig. 1. Cylinder 1 encloses piston 2, steam-chest 3 contains valve l (hereinafter called the main valve), which controls ports 5' and 6 (hereinafter called the'main ports), along which, steam, entering said steam-chest by way of passage 7, passes .al-

. ternately to the cylinder and thence to exhaust 8 in the usual way. Piston 2 by means of piston-rod 9, crosshead '10 (sliding in guidesnot shown), and connecting-rod 11, rotates crank-pinl2 of crank 13 aroundthe circular path .14, thus'turning the "crankshaft. Suitably located on saidgcrankshaft is an eccentric or crank indicated by itscentre-lfi, which, by means of eccentric-rod 16 connected at point 17 with valve-stem 18, operates said main valve 1 and arranged to out off steam from the cylinder 1, earlier than is deemed necessary for satisfactorily starting the engine. Thus far as described, the engine is normal. To assist in starting, 1 provide two auxiliary ports 19 and 20, each communicating with an end of cylinder 1, said auxiliary ports are so designed that the steam passing through them is so restricted that it can be efiective only at slow piston speeds: steam through passage 21 supplies said auxiliary ports, which are controlled by auxiliary valve 22. Also on the crankshaft, is suitably located a second eccentric or crank, indicated by its centre 23, and which, by means of auxiliary rod 24 connected at point 25 to auxililiary valve stem 26, operates said auxiliary valve 22 at a different phaseto that of the said main valve 4:: consequently, if auxiliary valve 22 be adjusted to admit steam at the same time or later than main valve l, it will cut off later than said main valve as shown by study of Figure 2. The main valve is shown about to open main port 5, the piston is virtually at the end of its stroke, and auxiliary V valve 22 has both auxiliary ports closed.

Fig. 2.. View (a). When crank 13 is revolved to the position shown in this view, the other moving parts occupy the posit-ions seen. Piston 2 has travelled about 12% of its stroke, main valve 4 is at the end of its travel, giving a maximum opening through main port 5,

and the auxiliary port 19 is about to admit steam to the cylinder. View (6) shows the main cut-off position, piston 2 has traversed about 38% of its stroke, and, when operating fast, completes its stroke virtually by the 1 return stroke.

expansive power of the imprisoned steam, due to auxiliary port restrictions aforesaid. It is also obvious that if the engine stopped in this position, it could not be restarted by steam from valve-chest 3. At this time auxiliary valve 22 is fully open, and steam,

main valve 4 and auxiliary valve 22 are in similar positions, relative to said piston, and so the same sequence of events occur on the Summarizing the chief features; steam is not admitted to the cylinder prior to admission by the main valve, the

auxiliary valve opens before main valve out off, and cuts off after the main valve has cut off, preferably, as in this case, ust as the main valve is about to exhaust, beyond which point it is obviously wasteful to continue auxiliary steam admission.

Fig. 3. Here is indicated in greater detail, a preferred method of applying the principles of this invention to a locomotive type cylinder having a main valve of inside admission piston type, operated by a Vv alschaert or similar style of gear. The auxiliary valve 22 is also of inside admission type, and is operated entirely by the main valve gear. It is too well known in the art to require illustration here, that member 31 of Fig. 3 of the style of gear mentioned, receives its motion from an eccentric or crank located at 90 de grees with the engine main crank, and is therefore at the centre of its stroke when the piston is on dead centres, and also that the main valve lap and lead are provided entirely by the combination lever which is operated jointly by the movement of the piston and member 31, connected at 32. Main valve 4 moves back and forth in its bushings 33, openings in which communicate with main ports 5 and 6 in the usual manner.

In the same steam chest, and located conveniently for operating connections, is auxilary valve 22, also sliding in perforated bushings, 3st, and communicating with the same ports 5 and 6. The respective valve actions can be followed by reference to Figure 1-.

Fig. This shows combination lever 29 in the corresponding positions it occupies when piston 2-is at each of the various positions shown in Fig. 3 and the four views of Figure 2; For convenience, these positions of the concerned parts are shown by the numeral l and letters a?) c and (Z atiixed to the numerals of the several parts, and the centre line BB indicates the central position of main valve a, the auxiliary valve 22 and connection 28. Points 28, 30 and 32 are indicated, as seen, by dots on the lever. It will be seen that the auxiliary valve opens at posi tion (a) and closes at (a), and that the main valve closes slightly later than at, piston position (6). As the main valve cut-off is progressively shortened (accomplished of course, by decreasing the travel of. point 32), the auxilary port will, open correspondingly later, to a less extent, and close earlier, until it finally fails to open at all, and the engine then operates on steam supplied by the main valve only, re ardless of engine speed. Figs. 7 to 10 inclusive show the piston and valves in four important relative positions. In Fig.

7- the crank is on dead centre, the main valve l showing lead and the au liary valve 22 is in its central position, which, thus arranged,

it occupies at this crank position regardless of any change of main valve cut-off during running.

Fig. 8. about to admit steam'to passage 5, the main valve l is well open and the piston at about Herethe auxiliaryvalve 22 is seen in its cut-01f position, the main valve 4 not yet uncovering passage 6 to exhaust and the piston 2 has travelled about of its stroke, on completion of which, of course,valve 22 will be as seen in Fig. 7, valve 4; will occupy. the same position relative to passage 6, which it occupies relative to passage 5 in Fig. 7.

I have herein referred to the application of this invention to steam operated engines, but it will be obvious that any expansible fluid could be used as the motive means: also that other than sliding types of valve may be employed, indeed any kind of valve that may be operated by the usual valve gears may be used as main or auxiliary valves under this invention. v

The auxiliary cut-oil can be regulated by design to take place at any desired piston position after the main valve has cut oil, preferably at that point where the main valve commences to open for release when operat-- ing at maximum travel. With this invention very short maximum main valve cut-ofi's may be employed, limited only by the point of release of that valve which should not be earlier than the desired maximum auxiliary valve cut-oil point. It will also be clearly seen that, where reversing means are employed, similar auxiliary valve action takes place in either direction of operation.

Furthermore, it is to be understood, while I have herein shown and described several preferred embodiments of this invention, the same is nevertheless susceptible of many minor modifications in the form, proportion, and relative arrangement of the several parts: and I accordingly reserve the privilege of adapting all such legitimate changes as may be fairly embodied within the spirit and scope of the invention as claimed.

What I claim is 1. A steam engine, including, (1) a cylinder having a main steam port and an auxiliary steam port each in direct connection with the cylinder bore, (2) a main valve to control said main port, (3) means for operating said main valve, (4:) an auxiliary valve-independent of said main valve-to control said auxiliary port, (5) a lap on said auxiliary valve, (6) means for operatively connecting said auxiliary valve with a member of said main valve operating means at a point on the latter to give said auxiliary valve actuation which, in conjunction with said lap, gives said auxiliary valve negative lead and a cut-off which is later than that of said main valve, and (7) means for shortening the cut-off of the main valve and for automatically shortening the travel of said auxiliary valve to close said auxiliary port when the main valve cut-ofi" is shortened.

cylinder, (3) a main valve to control said main port, (4) apiston type auxiliary valve independent of said main valveto control said auxiliary port, (5) a lap on said auxiliary valve, (6) a valve-gear to actuate both said main and auxiliary valves, (7) means for operatively connecting said main valve to said gear, (8) a member pivotally connected to said auxiliary valve and to a member of said valve-gear at a point on the latter to give said auxiliary valve a phase of actushortened.

RONALD FRANK KNIGHT.

2. A steam engine, including, a cyl- A I inder having a main steam port and an'auxiliary steam port each in direct connection with the cylinder bore, (2) a piston, in said

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