US2157578A - Reversible internal combustion engine - Google Patents

Description

9, 1939- E. o. P. THEGE ET AL 2,157,578

REVERSIBLE INTERNAL COMBUSTION ENGINE Filed April 25, 1956 2 Sheet s-Sheet l 91K smmwa v/m V55 May 9, 1939. E. o. P. THEGE ET AL REVERSIBLE INTERNAL COMBUSTION ENGINE Filed April 23, 1936 2 Sheets-Sheet 2 Patented May 9, 1939 EdvinOssian 1 INTIENAL COMBUSTION ENG .lhege and John Henry Percival wliliamllllhll, Stockholm. Bwedemaflgnors uuamumssunmmsm 'muamsuuss. mam

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Means hitherto used for direct reversal of internal combustion engines by means of compressed air have the disadvantage that it has not been possible to elect the reversal in a suiiiciently short space of time. This is due to the fact that, in reversing the direction of motion, it has been necessary first to place the control lever in the stop position and to let the engine come to a stop before the admission oi compressed air for the purpose of starting the engine in the opposite direction. Ii. this is neglected it may occur that the engine continues its movement in the same direction which will cause further delay or danger and losses of compressed air. In such a case, distance or remote control has generally not been feasible as, at a distance, it is impossible to determine when the engine has stopped and to determine the instant at which compressed air may be admitted for eflecting the reversal of the engine.

The present invention relates to a reversing mechanism for internal combustion engines, by

the use of which the above mentioned diiiloulties are avoided and which thus permits the reversal, i. e. the admission oi compressed air for changing the direction of motion, to be effected immediately without the necessity for waiting until the engine has stopped. Hence, the control lever is according to this invention moved directly from the forward position into the rearward position, or vice versa, without having first to be placed in the stop position until the engine has stopped. An arrangement of this kind has the advantage that the reversal takes place much more rapidly. and, besides, it may be used with remote control, in which case as mentioned above he who performs the operation has no opportunity of determining whether the engine has come to rest or not.

Some of the auxiliary apparatus used in reversing may be constructed in many different ways, and thus the invention is not restricted to any particular design of this apparatus.

In order to explain more clearly the principle underlying the invention, there is illustrated in the accompanying drawings a suitable embodiment which will be hereinafter described.

Fig. 1 is a view partly in elevation and partly in section of a starting valve and reversing valve arrangement embodying the invention.

Fig. 1a is a transverse cross-section on reduced scale taken generally along the lines la-la oi Fi 1;

Fig. 2 is a longitudinal cross-section showing on enlarged scale a part of the valve mechanism shown in Fig. 1;

Fig. 3 is a transverse cross-section through the valve mechanism shown in Fig. 2 and also shows in cross-section an engine exhaust valve .controlled thereby;

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l'ig.4isasectionsimiiartol"lg. Sshowing'tbe partsotthevalveotl'lgsdandt in a diii'erent position;

Fig. 5 is a section partly in elevation showing an engine cylinder with its associated starting and exhaust valves; and

Fig. 8 is a sectional view partly in elevation of the starting control valve shown in Fig. 1.

In said embodiment, Figure 1 illustrates previously known arrangements for supplying compressed air to the starting valves from a special regulating member (distributing slide valve). These arrangements, with the exception of a mechanism supplying compressed air to the exhaust valves, are known for instance from the U. 8. Patent No. 1,886,234, and. therefore. they will here only be described in a summary way.

Each of the working cylinders of the engine is provided with a starting valve I and all these valves are via pipes I and a common conduit 8 communicating with an air admission valve 4. Valve 4-, to which compressed air is admitted through a pipe I from a suitable receiver (not shown), is provided with .a control lever I and communicates via a pipe I with a housing I in which is located a distributing slide valve or sleeve 9. The valve case 8 and the distributingvalve are shown in transverse section on smaller scale in Fig..1a and it will be evident from this transverse section that the case 8 communicates with all the starting valves I through conduits I 0. The distributing slide valve 9 is rotated in the one or the other direction, the rotary motion being transmitted from the crank shaft of the engine by means or a suitable gear comprising a gear wheel ll mounted on the slide valve shalt l2. Said shaft is driven at the same speed as the crank shaft, and the valve 9 is slidably but not rotatively adjustable on the shaft II. The displacement of the slide valve is eflected by means of a hand lever is which may be placed in the positions "ahead, stop and reve The connection between the hand lever l8 and the distributing valve 8 is formed by levers ll, l5 and a link it. The reversing operation of the arrangement above described has already been indicated in the foregoing.

. It need here only be stated that the compressed air distributed to the various conduits II by the distributing valve 9 is operative in the starting valves I for opening these valves, so that starting air coming from the opened air admission valve I is supplied via the pipes 3 and 2 at the right moment to each of the cylinders in a dennite order of sequence.

In order to render possible more rapid manoeuvring than is possible with the use of the arrangement above described, the cylinders oi the engine are, according to the present invention, provided with special exhaust valves which,

when the piston is at the upper dead center, are opened in order to discharge into the atmosphere the compression air from the cylinders at the end of the compression stroke. The opening of these exhaust valves may be eflected by means of compressed air which is admitted from a special distributi'ng'member, preferably in the form of a slide valve (32, Figs. 1, 2, 3 and 4), which may be driven from the previously mentioned distributing slide valve 9 by means of asuitable claw or dog-clutch connection. However, there is nothing to prevent the slide valve 32 from being driven by other suitable means, and hence the transmission of motion from'the distributing slide valve 9 is only to be considered as an example of realization, which is illustrated on the accompanying drawings wherein Figs. 1 and 1a show both a longitudinal and a transverse section of a previously known arrangement;

The case or shell 29 of the slide valve for distributing air to theexhaust valves (hereinafter called the second slide valve) is, as already mentioned, connected to the case 8 of the distributing valve 9 (called the first distributing valve). In the distributing valve 9 there is secured a carrier in the form of a shaft 3| extending into the second distributing valve 32 .and provided with a claw 33 (Figures 2 to 4), which is adapted, upon the rotation of the shaft in the one or the other direction, to cooperate with or press against the one or the other side of a corresponding claw 34 located on the second distributingvalve 32. The mutual positions of the claws 33 and 34 are shown in the position for forward movement in Figure 3 and in that for reverse movement in Figure 4. As will be apparent from these figures,

the claw 33 of the shaft 3| may be turned through an angle of 180 in relation to the claw 34 of the second distributing valve 32, which takes place when the direction of rotation is changed from ahead" to "reverse or vice versa.

The compressed air conveyed from the air admission valve 4 through the pipe 1 to an axial bore (dotted lines) in the first distributing valve 9 continues to the second distributing valve 32 through a bore 35 (Figure 2) in the carrier shaft 3|. From the bore 35 passages 39 and 31 branch ofi, which passages are adapted to register with passages 38 and"39 provided in the second distributing valve 32, so that air can enter into recesses 40, 4| in the valve 32. Upon rotation of the valve the edges of the recesses 49, 4| will respectively open and shut passages 42, 43, 44 and 45 provided in the housing or shell 29 of the second distributing valve 32.

From the passages 42, 43, 44 and 45 the air is conducted through pipes 49 to corresponding exhaust valves 59. Each exhaust valve is maintained open as long as compressed air is admitted through conduit 49. The exhaust valve is shut, on the other hand, by the pressure in conduit 49 being released when the compressed air is discharged from the same through one of the recesses 41, 41a (Figure 2), when the second distributing valve 32 is in the position for forward or reverse movement, the passages 46 in the valve case then registering with the recess 41a. (for forward movement) or the recess 41 (for reverse movement). The passages 36, 33 and the recess 49 form a connection for the compressed air upon the reversal from reverse to ahead, and the passages 31, 39 and the recess 4| a connection for the compressed air upon the reversal from ahead" to "reverse. In order that the drawings shall not become too complicated, only the ans-1.57s

passages 31, 39 and the recess 4| have been shown in Figures 3 and 4. The passages 39, 33 and the recess 49 are situated on the opposite side in relation to the passages 31, 39 and the recess 4|. Moreover, the slide valve 32 as shown in Figure 2 occupies an intermediate position (the stop position).

The reversal from full speed ahead" to full speed reverse takes place in the following manner:

(l) The control lever I3 is moved from the for- "ward position directly into the reverse position.

Due to this the passages 31, 39 and 4| in the slide valve 32 are set in such positions as to register 1 with the passages 42, 43, 44 and 45 in the valve case 20.

31 in the carrier shaft 3| registers with the pas-' sage 39 in the second distributing valve 32 (see Figure 3), so that compressed air is supplied to the exhaust valves 5|), which on account of the above mentioned adjustment takes place at the moment when the corresponding crank passes the upper dead center. Due to compressed air admitted into the cylinders through the starting valves, there will be obtained a greater strength of compression than normally, causing the engine to be rapidly braked through the increased compression in one cylinder after the other. However, the compressed air will not get an opportunity of expanding, but is allowed to escape through the exhaust valves 59 when the crank has passed the upper dead center. When the engine has as a result come to rest, it immediately starts in the opposite direction, driven by air from the starting valves At this instant the slide valve 32 comes to a stop on account of the friction against the valve case, and continues to stand still until the claw 33 has turned through anangle of 180 and carries the claw 34 with it in the new direction of rotation (see Figure 4). By this means the passage 31 is evidently turned through an angle of 180 and communicates no longer with the passage 39 in the slide valve 32 (see Figure 4). By this means the air is shut off from the exhaust valves 50, and hence these cease to operate and are closed under spring action. The exhaust valves 50 may be of such a nature that at the same time they act as safety valves.

According to the embodiment of the exhaust valves shown in Figure 3 these valves communicate via passages 53 with passages 56 provided in the cylinder cover, for example. In the valve cage there is slidably arranged a valve stem 51, the upper end 52 of which normally forms a sealing join against a valve seat under the influence of a spring 59. A passage 54 leads from the valve seat to a silencer for example. In connection with the valvestem 51 there is provided a plunger 59, above which compressed air is introduced through the previously mentioned pipe 49, said air efl'ecting the opening of the exhaust valve, so

that air compressed in the engine cylinder is discharged into the atmosphere at the end of the compression stroke. As appears from the foregoing the exhaust valves are evidently operated pneumatically, i. e. arranged to be started into operation by means of compressed air admitted. In conjunction with the reversal the use of such valves involves certain advantages, and the pneumatic valve control of the exhaust valves forms, therefore, an essential part of the invention.

As already pointed out the drawings illustrate only an example of realization, the various parts of which may be altered in many different ways within the scope of the invention.

We claim:

1. A reversible internal combustion engine of the kind in which air is compressed in the engine cylinders including pneumatically actuated relief valves for discharging air compressed in said cylinders, distributing valve means mechanically operated from the engine for automatically supplying compressed air to said relief valves at timed intervals to open the same at the ends of the compression strokes of the respective cylinders, and engine control means including an operating member shiftable to forward and reverse positions, said distributing valve means including mechanism operable to continue to supply compressed air to said relief valves after shifting of said member from one of said positions only so long as the engine continues to rotate in the same direction as that occurring prior to the shifting of said member.

2. A reversible internal combustion engine of the kind in which air is compressed in the engine cylinders, including pneumatically actuated relief valves for discharging air compressed in the engine cylinders to a zone of low pressure, and

means including an engine driven distributing valve for automatically supplying compressed air at timed intervals to said relief valves to open the same at the ends of the compression strokes of the respective cylinders, said relief valves including pressure responsive parts opening under the influence of excessive compression pressures in said cylinders, whereby to cause the relief valves to act as safety valves for said cylinders.

3. A reversible internal combustion engine of the kind in which air is compressed in the engine cylinders, including pneumatically actuated relief valves for discharging air compressed in the engine cylinders, distributing valve means for supplying compressed air to said relief valves to open the same at the ends of the compression strokes of the respective cylinders, starting valves for the engine cylinders, distributing valve means for supplying compressed air to said starting valves, means for mechanically operating both of said distributing valve means from the engines, a control member for controlling the direction of operation of the engine, and means for adjusting the position of said distributing valve means in response to movement of said control member.

4. A reversible internal combustion engine of the kind in which air is compressed in the engine cylinders, including pneumatically actuated relief valves for discharging air compressed in the engine cylinders, starting valves for the engine cylinders, engine driven distributing valve means for supplying compressed air to said starting valves, engine driven distributing valve means for supplying compressed air to said relief valves to open the same at the ends of the compression strokes of the respective cylinders, an engine control member for shifting the positions of said distributing valve means, and a lost motion connection between the engine and the second mentioned distributing valve means operative upon reversal of the direction of rotation of the engine to cut off the supply of compressed air distributed by the second mentioned distributing valve means to said relief valves.

5. A reversible internal combustion engine including air starting and reversing means, said means including an engine driven air distributing valve and a. control member for shifting said distributing valve to forward and reverse positions, pneumatically actuated relief valves for discharging to a zone of low pressure air compressed in the engine cylinders, a second distributing valve for delivering compressed air to said relief valves to open the same at the ends of the compression strokes of the respective cylinders, the second mentioned distributing valve being shiftable in response to movement of said control member from either of the terminal positions of the latter to cause said relief valves to open, and there being a lost motion driving connection between the engine and the second mentioned distributing valve for causing the supply of compressed air to saidrelief valves to be cut off upon reversal of direction of rotation of the engine after the shifting of said control member to effect such reversal.

6. In areversible internal combustion engine, the combination with air starting and reversing means including a control member shiftable to forward and reverse positions, of pneumatically actuated relief valves for the engine cylinders, and engine driven distributing valve means for admitting compressed air to said relief valves to open the same at the ends of the compression strokes of the respective cylinders, said distributing valve means being shiftable in response to movement of said control member from one of its terminal positions to cause said relief valves to be opened and being automatically responsive to reversal of direction of rotation of the engine subsequent to such shift of said control member to cut off the supply of operating air to said relief valves, whereby to effect automatic closure of the same upon such reversal of the engine.

'7. A reversible internal combustion engine of the kind in which air is compressed in the engine cylinders including pneumatically actuated relief valves for discharging air compressed in said cylinders, distributing valve means mechanically operated from the engine for automatically supplying compressed air to said relief valves at timed intervals to open the same at the ends of the compression strokes of the respective cylinders, and engine control means including an operating member shiftable to forward and reverse positions, said distributing valve means including mechanism operable to continue to supply compressed air to said relief valves after shifting of said member from one of said positions as long as the engine continues to rotate in the same direction as that occurring prior to the shifting of said member and means automatically actuated by reversal of the direction of rotation of the engine after shifting of said member for causing the supply of compressed air to said relief valves to be interrupted.

EDVIN' OSSIAN PARCIVAL THEGE. JOHN HENRY WILLIAM JULIUS.

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