US2243883A - Maneuvering gear for reversible internal combustion engines - Google Patents

Description

June 1941- e. E. RAMSTAD" MANEUVERING GEAR FOR REVERSIBLE INTERNAL COMBUSTION ENGiNES Filed Feb. 27, 1939 5 Sheets-Sheet 1 MULTIPLE. PORTBD COCK,

(Ittornegs June 3, 1941. RAMSTAD 2,243,883

MANEUVERING GEAR FOR REVERSIBLE INTERNAL COMBUSTION ENGINES Filed Feb. 27, 1939 5 Sheets-Sheet 2 FROM STARTING .AKR. RECEIV ER,

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attorneys June 1941- e. E. RAMSTAD 2,243,883 HANEUVERING GEAR FOR REVERSIBLE INTERNAL COHBUSTION ENGINES Filed Feb. 27, 1939 s Sheets-Sheet s Gttomegs June 1941- G. a RAMSTAD 2,243,883

MANEUVERING GEAR FOR REVERSIBLE INTERNAL COMBUSTION ENGINES .F'iled Feb. 27, 1939 5 Sheets-Sheet 4 6 Jnpmtor sieolw e Exam/flab June 3, 1941. s. E. RAMSTAD 3. 83 IANBUVERING GEAR FOR REVERSIBLE INTERNAL COMBUSTION ENGINES Filed Feb. 27, 1939 5 Sheets-Sheet 5 3nnentor Emma BB a a? i Gttornegs Patented an; 3, 1941 MANEUVERING GEAR FOR. REVERSIBLE INTERNAL COMBUSTION ENGINES George E. Ramstad, Milwaukee, Wis., assignor to N ordberg Manufacturing Company, Milwaukee, Wis., a corporation of Wisconsin Application February 27, 1939, Serial No. 258,777

20 Claims.

This invention relates to maneuvering gears for internal combustion engines and particularly for Diesel and similar enginesof the type including air starting valves. The engines may be twocycle or four-cycle, but a four-cycle engine is chosen for illustration.

The object of the invention is to produce a maneuvering gear having a single controlling handle which operates not only the reverse gear but also an engine brake, an air starting mechanism, and the fuel control. Arrangements of this sort are particularly desirable for ship propulsion, and the present invention has demonstrated its utility in commercial installations.

The controlling handle has a mid position which is a neutral position in all respects, except that a fluid pressure brake is then applied to the engine to maintain it at rest. Movement of the controlling handle in either direction from this mid position within the limits necessary to cause actuation of the reverse gear of the engine, releases the brake.

Movement of the controlling handle through definite reversing ranges, one on each side of the mid position (stop position) operates valves which cause reverse actuation of a reversing motor which sets the valve gear of the engine for forward and reverse running selectively. Such setting corresponds with the direction in which the controlling handle is moved from mid-position.

An interlock between the reversing motor and the controlling handle is provided and operates through the valve mechanism which controls the reversing motor in such a way that until the reversing motor has completely responded, the controlling handle cannot be moved beyond the reversing ranges. However, so soon as the reversing motor has completely responded, the maneuvering gear freed, so that its controlling handle may be moved further to a position in which air is supplied to the starting headers.

' The interlock is so contrived that if the reversing motor stops short of full stroke for any reason, the interlock prevents motion to air starting position in both directions until the reversing motor moves toone of its limiting positions.

The air starting valves used are of the known type in which normally retracted cam followers can be shifted into coactive relation with cams which then serve to actuate the starting valves in timed relation to the engine crank. The desired shifting of the followers is caused by the admission of starting air to the starting header.

Thus the starting action is initiated and termicontrol of the fuel feed rate.

nated merely by turning the air on and off. Devices of this type are well known in the art and take many specifically different forms.

Preferably throughout the ranges of motion thus far described, the fuel pump controller is positioned by a cam on the maneuvering shaft in its zero fuel feeding position; but movement of the controlling handle in either direction beyond the air starting position, cuts off the starting air and then causes progressive increase of fuel feed.

The valve which admits air to the starting header is operated by one or the other of two switch cams carried by the maneuvering shaft, in such a way that the valve is opened and then allowed to close as the controlling handle moves away from its mid position, but because of the switching of the cam, is not operated upon return to neutral position. As neutral position is closely approached, however, the switch cam is reset so as to function on the next shift away from neutral position.

The new arrangement has a number of advantages. It can be applied to any valve reversing gear, although it is here shown for illustration as applied to a valve reversing gear having two sets of cams, -a forward set and a reverse set, mounted on an axially shiftable cam shaft.

Thus the single maneuvering handle may be used to start the engine with compressed air in eitherdirection, control its speed while running on fuel oil, in either direction, stop the engine and apply the brake. The engine may then be again started-in either direction. If the en-.

gine be restarted in the same direction in which it was running previously, so no shift of the reversing gear is required, the operator is free to shift directly to air starting position, but if the engine is restarted in the contrary direction, the maneuvering handle is locked against entering the corresponding air starting position until the reversing gear has completely responded.

Thus the engineer is left in complete control of the duration of time he maintains the engine in air starting position as well as in complete However, a check is placed against too rapid attempted reversal,

such check being limited to the period actually necessary to effect the reversal of the distributing valve gear of the engine. Once such reversal has occurred, the operator is again free as to manipulation.

The invention also includes a simple manually operable means for shifting the reversing gear of the engine, either for valve setting or to meet some emergency rendering the pneumatic reversing gear temporarily ineffective.

An important advantage of the maneuvering gear is that the maneuvering shaft may be located in various positions adjacent the engine and thus may be located to suit particular installation problems. This follows from the fact that all except two of the connections between the maneuvering mechanism proper and the reversing braking and starting devices (all of which are necessarily mounted on the engine) are pneumatic and require only piped connections. The two exceptions involve linkages or the equivalent which have a limited range and speed of motion, so that they may be variously designed without serious difficulty. These are the linkage from the fuel control 'cam follower to the fuel pump adjusting mechanism and the interlock linkage between the reversing mechanism and the maneuvering shaft.

The preferred embodiment of the invention will now be described by reference to the accompanylng drawings, in which:

Fig. 1 is a diagrammatic perspective view partly in section, showing the actuating mechanism for reversing the engine, and specifically for shifting the cam followers to clear the cam shaft. then moving the cam shaft, and then restoring the followers.

Fig. 2 is a perspective diagram with parts shown in section. This view includes the maneuvering shaft with its cam and associated follower for the fuel pump controller, and the cams.

and associated followers for those valves which control, respectively, the engine brake, the motor shown in Figure l for operating the reversing gear, and thesupply of air to the starting header.

Note-Figs. 1 and 2 together comprise 9. diagram of the essential components of the maneuvering gear, without limitation to the preferred relative positions thereof.

Fig. 3 is a view partly in se'ctionand partly in elevation, looking at the forward end of a multi-cylinder marine engine and illustrating the preferred location of the parts shown in Figs. 1 and 2 (a cover plate being removed).

Fig. 4 is a view partly in elevation and partly in section, showing the left side-of the engine at the forward end thereof. In this view the casing for the maneuvering gear and the reversing gear is broken away. The engine is' drawn as it would appear with one of the cover plates normally overlying the valve cams and followers removed to expose these parts to view.

Fig. 5 is an enlarged axial sectional view through one of the cylinders showing the location and arrangement of the valve mechanisms, both for fuel and starting air, and the location and arrangement of the corresponding fuel pump and the control shaft for all the fuel pumps,

there being one such pump 'for each cylinder.

Fig. 6 is a' development of the cam which shifts the cam shaft of the engine. Fig. '7 is an enlarged section through the maneuvering shaft, the plane of section being indicated by the line 1- "I of Fig. 3. In this view one of the switch cams and its carrier is shown in section and the other is shown in elevation.

Fig. 8 is a plan view of the parts shown in Fi '7.

Fig. 9 is a plan view of the axially shiftable cams which operate the admission valves to supply air selectively to the two ends of the engine-reversing motor cylinder. This view indicates the actual positions of the cams and foilowers.

As stated, the invention may be applied to any engine having a reversing'gear' which may be set in two alternative positions to change the timing of events so that they will correspond to forward running and reverse running, and provided the air starting gear is of a type which is so reversed, and may be rendered active for either direction of running simply by the admission of starting air to the starting header.

While engines corresponding to this general description are well known and consequently need not be set forth in detail, it appears to be necessary to describe in'general terms one type of such engine to indicate one way in which the present invention can be applied, and to serve as the basis for a clear and intelligible description of operation. Consequently one such engine will be generally described with the understanding that the description is exemplary and not limiting.

Turning now to Figure l, the vertically shiftable member H typifies the reversing controller, i. e., a part which in its uppermost position, as shown in Figure 1, sets the engine to operate in its forward direction and in its lowermost position sets the engine to operate in its reverse direction. The specific way in which it does this is not a part of the invention, but one known way will now be described.

The member Ii carries a rack H which meshes with a pinion 13 fast to a larger gear I. The gear I4 meshes with a pinion l5 fast on a reversing crankshaft l6 which is parallel with .the cam shaft ll of the engine and is approximately coextensive in length therewith. The gear train just described is such that when the member ll moves from one of its limiting positions to the other, the shaft i6 will rotate through 360 of angle. The cam) shaft H is driven from themain crankshaft of the engine at proper speed. In a four-cycle engine this speed is one-half the angular speed of the crankshaft. The present engine is assumed to be of the four-cycle type. Since these parts are conventional, the crankshaft and driving train to the cam shaft are not illustrated.

As is common in such engines, the cam shaft 1! is splined to the gear which drives it so that its angular relationship .to the engine crankshaft is fixed, but the cam shaft may be shifted axially to bring either of two sets of cams selectively into co-ac-tive relationship with the cam followers and push rods.

In Figure 1, the forward cam for the inlet valve of one cylinder is indicated at Hi and the reverse cam for the same inlet valve is indicated at I81. The push rod for this inlet valve is indicated at i9 and carries a roller 2| which serves as a cam follower and co-acts 'with one or the other of the cams l8f, I81, depending on the axial position of the cam shaft [1.

The push rod I9 operates an inlet valve and acts thereon through a rocker. The valve and rocker are not shown in the drawings but the rocker is similar to the exhaust valve rocker 31 of Figure 5. The valve is a poppet valve mounted in the cylinder head, and is forced in an opening direction by upward motion of the push rod 19, as usual. Valves of this type are so well known for inlet and exhaust purposes in Diesel engines that illustration and detailed description are deemed unnecessary.

Fast on the shaft I6 is a spiral cam 22. This cam 22 has a groove 23 whose form is indicated in the development diagram (Figure 6). The groove 23 in the cam 22 receives a follower roller 24 fast in the upper end of a shifter yoke 25 fulcrumed on the frame of the engine. The lower end of the yoke 25 is forked and connected with a sleeve 28 which is swiveled between collars on the end of the cam shaft I! in such a way as to permit rotation of the shaft l7 and permit the arcuate movement of the lower end of the yoke 25, so that rocking motion of the shifter yoke 25 entails simple axial shifting of the shaft I1.

As'indicated in Figure 6, the groove 23 in cam 22 is so formed that in the first 127 of rotation of the cam the yoke 25 is not moved. -In the next 106 of rotation of the cam 22 the yoke 25 is shifted through its entire range of motion which is so chosen as to interchange the cams l8f, |8r beneath the roller 2|. In the remaining 127 of rotation of the cam 22, the yoke 25 remains at rest.

The lower end of the push rod 9 is guided by a link 2'! pinned at 28 to the push rod I9 and connected to a crank 29 fast on the shaft l6, so that the crank turns with the cam 22. When the member H is at either limit of its movement, the crank 29 is horizontal and extends away from the push rod l9. Consequently as the shaft |6 rotates from either of its limiting positions, the push rod l9 and roller 2| are displaced laterally so as to clear both the cams |8f, |8r, then the cam shaft I1 is shifted axially to interchange the cams, and finally the push rod l9 and roller 2| are restored to their active positions with reference to the selected cam.

In a four-cycleengine each cylinder is equipped with an inlet valve, an air starting valve, an exhaust valve and a fuel pump, and the timing of each of these devices must be chan ed to reverse the direction of running. All of these devices are operated by push rods and all of the push rods are shifted during reversals bycrank and connecting rod elements identical with the parts 21, 28 and 29. These three numerals are applied to these par s wherever such arts ap e r. irrespective of the particular push rod with which they are connected. Thus in Figure these components appear and happen to be those which control th Dnsh rod 32. 'Tt s un erst od. of course, that all the cranks 29 are aligned on the shaft l6 and swing in unison. so that all the push rods are moved out in unison and then restored in unison.

In Figure 4 thetwo cams for the a r startin valve are indicated at 3|f and 3| r and the r push rod is indicated at .32. The two cams for the. exhaust valve are indicated at 33; and 33r and their push rod at 34. Two cams for ac uatin the fuel pump are indicated at 35f and 35r and their push rod is indicated at 36.

Figure 5 shows some of the mechanism operated by the push rods just mentioned. The push rod-34 in that figure is hidden by the push rod 32, but operates a rock lever 31 which, throu h the adjustable thrust nose 38, engages the stem 39 of the exhaust valve. The spring s own at 4| is the seating spring for the exhaust valve. This exhaust valve, as viewed in Figure 5, is behind the fuel injecting nozzle 42 but is wholly distinct therefrom. The inlet valve and its rocker are forward of the plane .of section in Figure 5 but are essentially similar to the corresponding parts of the exhaust valve mechanism (see the parts: 31, 38, 39 and 4| in Figure The fuel pump indicated generally at .43 is an ordinary fuel injecting measuring pump of a type so well known in the art as'hardly to require description. It discharges through the pipe 40 to the fuel injection nozzle 42.

The measuring pump 43 includes a plunger not shown, which isforced upward by the push rod 36 and when pushed upward delivers 011 through the pipe 49 to the nozzle 42. The complunger stroke at which the spill-back and consequently the termination of fuel delivery, occurs.

Thus injection starts at a definite point in the cycle and continues for a variable portion of the working stroke, depending on the position of the member 44. which. therefore. typifies any adjustalble means for varying the quantity of fuel injected per cycle.

Pumps of this general spill-back type are illustrated, among other places, in the patent to Ehrat, No. 2,127,165, August 16, 1938.

There is a pump 43 for each cylinder in the engine and the controlling racks 44 of the varis Dumps are adjust d in un son by a rock shaft 45 having parallel arms 46. one connected with each rack 44. The shaft 45 is connected by an arm 41, link 48. bell crank 49 and link 5| to the cam follower 52 whose position is controlled by the maneuvering gear hereinafter described.

The air header for the air starting valves is indicated at 53 in Figure 5 and is connected to starting valves, one for each cylinder. one such starting valve being indicated by the numeral 54 applied to its body in Figure 5.

It will be observed in Figure 4 that the push rod 32 of the air starting valve is shown in a raised position, so that it cannot co-act with its cams 3| f, 3|r, and this position is assumed by the push rods for all the air starting valves when the air supply is turned off and the header 53 is vented. This action is provided for in the c struction of the valves 54.

The air valve proper is a poppet valve 55 opening toward the interior of the cylinder 56. The valve is ur ed in a closing direction partly by pressures existing in the cylinder and partly by a coil compression spring 51 surrounding the upper portion of its stem. The valve may be forced in an opening direction by the adjustable thrust nose 58 on the rock lever 59, which rock lever is connected to the upper end of thepush rod 32. The rocker 59 is drawn in a counterclockwise d rection as viewed in Figure 5. by the coil tension spring 6|.

The rock lever 59 is fulcrumed eccentrically at 62 on a yoke 63 which is journaled on the shaft 64 and which has lugs engaging a groove 65 in the upper end of the piston 68. The piston 56 works through a limited range in a cylinder formed in the upper portion of the housing 64, reacts against spring 51, and is subject, on its lower end, to pressure in the starting air header 53 to which it is connected by the pipe 61.

- When the header 53 is under pressure the piston 66 is forced upward to its limit of motion, shifting the yoke 63 and lowering the fulcrum 62, so that the push rod 32 is shifted downward until its roller is in co-active relation with the air starting cams 3If or 3Ir, whichever is in active position. When the header 53 is vented the springs restore the parts to the positions illustrated, raising push rod 32.

In Figure 5 one of the engine pistons is indicated at 68 and its connecting rod at 69. Rod 69 is of course connected at its lower end to one of the cranks on the engine crankshaft (not shown).

The mechanism so far described is merely one form of reversing mechanism and air starting mechanism, with which the improved maneuvering gear can be used. No novelty is here claimed for this mechanism per se, and no limitation to its exclusive use for reversing and starting purposes is even implied.

To shift member I I of Figure 1, use is made of a pressure motor and associated stabilizing cylinder. The pressure motor cylinder is indicated at II and the stabilizing cylinder-at 12. They are arranged in tandem and are separated by a head I3 which has a collecting chamber I4 with drain pipe for removing any oil which may escape from cylinder 12 and to prevent entrance of air into the upper end of cylinder 12. In the cylinder II is a motor piston 16 and in the cylinder 12 is a controlling piston I1, both mounted on a piston rod 18, directly connected to the upper end of the member II. The working spaces in cylinder 12 above and below the piston 11 are normally connected together by way of pipes clearly shown in Figure 1 through an adjustable throttling needle valve I9.

The control piston 11 can be used to shift the valve mechanism, that is, to shift the member II upward and downward by manually operable means intended for use only in connection with valve setting and under conditions when air pressure is not available.

This mechanism comprises an oil pump 8| connected by pipe 82 with a multiple ported plug cock diagrammed in Figure l as two sections through the single cock. This cock thus combines a fourway cock 83 and a functionally related stop cock 84. It will be understood that the parts are formed in a single shell and in a single rotary plug so that the cock elements diagrammatically illustrated at 83 and 85 operate in unison Normally 84 is open as shown and 83 closes the communication to pipe 82 and also the vent 85. The cock plug can be turned in either direction from the normal position illustrated, in which event the conection through restricting valve 19 is closed and the pump 8| will be connected with one or the other end of the cylinder 12 (depending on the direction in which the cock is turned), the opposite end of the cylinder being simultaneously connected to the vent 85.

With the cocks so set, the pump 8| may be operated to move the piston I1 and the member II slowly in one or the other direction, depending on the setting in the cocks.

The connection 86 with the ported check valve 81 leads from the pressure lubricating circuit of the engine and is for the purpose of keeping the cylinder I2 constantly filled with lubricating oil. The parts 8| to inclusive form merely an accessory mechanism not directly concerned with the engine control, but'are useful in conjunction therewith.

Referring now particularly to Figure 2, and incidentally to Figures 3 and 4, which show the actual location and form of the parts, maneuvering mechanism proper will be described.

In Figure 2 the pipe 9| leads from the starting air receiver, in which receiver, as usual, air for starting is stored under pressure, the air being supplied to the receiver by any means common in the art. The valve 92, controlled by the hand wheel 93 and threaded stem 94, controls flow from pipe 9| to the chamber 95. When the valve zontally across the forward end of the engine below the "forward end of the cam. shaft I1, and

consequently below and to one side of the member II with its rack l2.

The shaft IOI has fixed to it a pinion I02 which meshes with a sector gear I03. The sector gear I03 and the control arm I04 are both fast on a shaft I05 which is journaled in a portion of the engine housing. The arrangement is such that motion of the handle I04 through a moderate angular range will rotate the maneuvering shaft IOI through its entire functional range. In the commercial embodiment this is Near the right hand end of the shaft MI is fixed a cam I06 with which co-acts the lower end of the follower 52. This, as has already been explained, is linked to the adjusting racks 44 of the fuel pumps.

The shaft IOI is shown in its mid position, that 1s, in the position in which the engine is stopped.

quently the members 44 for zero fuel feed.

In the example illustrated and as indicated on Figure 2' by legends, the shaft IOI, as viewed in Figures 2 and 3, turns over away from the observer to set the engine for astern running and turns over toward the observer to set the engine for forward running.

Fixed on the shaft IN is a cam I01. This cam coacts with the follower I08 holding that follower up in the neutral or stop position of the shaft IM and permitting the follower to descend rather rapidly as the shaft is turned in either direction from that position.

The follower I08 reacts through a coil compression spring I09 on a plunger I I I which, when forced upwardly, shifts two reverseiy seated poppet valves upward, such upward shifting closing the lower or exhaust valve H2 and opening the upper or supply valve H3. The valves H2 and H3 engage each other so that they can close only selectively. The supply valve H3 is urged to its seat by a coiled compression spring II4. When opened it admits air from the manifold I to the space II between the two valves, and since at that time the exhaust valve II2 will be closed and since the space H5 is connected by a pipe II6 to a brake cylinder III, the effect is to energize the brake cylinder. This occurs at least in the neutral or "stop position.

The brake cylinder II! is indicated diagrammatically in Figure 2, but it will be understood that when energized it forces the brake shoe against the engine fly-wheel and functions to hold the engine at rest. Since fly-wheel brakes are known in the art and since the construction of the brake is conventional, it is deemed unnecessary to illustrate the brake in complete detall.

When the follower I08 is allowed to descend upon rotation of the cam IN, the exhaust valve H2 opens and vents he brake cylinder through the exhaust port I I8. At the same time the supply valve II3 closes against its seat, partly under the urge of the spring H4 and partly under the urge of supply pressure.

The design of the cam I0! is such that the brake will be completely released while the engine is being put through its reversing cycle and before the reversing gear enters the air starting position. Within the limits just stated the necessary angle of motion of shaft IOI to vent the brake cylinder I I1 is a matter of design. The important thing is to release the brake before starting air is admitted to the header 53 as hereinafter described. It is considered advisable, but not strictly necessary, to keep the brake applied until just before the starting air is admitted.

Connected to the air manifold I00 is an air valve body H9 and an air valve body I2I which house valves arranged to be operated selectively by cam mechanism mounted on the shaft I0.. These valves serve to admit air to the opposite ends of the cylinder II, that is, to the spaces above and below the piston I6. The valve mechanisms housed in bodies H9 and I2I are essentially similar, but have slightly different operating characteristics and hence will be separately described.

Mounted within the valve body H9 is a poppet valve I22 urged in a closing direction by pressure in the manifold I00 and by the coil compression spring I23. When forced open the valve admits air from the manifold I00 to a pipe I24 which communicates through the check valve I25 with the pipe I26. Pipe I26 is in free communication with the upper end of the cylinder II above piston I6, The valve I22 has a fluted pilot I21 below which is a cylindrical stern I28. The stem I28 may be pushed upward to open valve I22 by a cam follower I29. When so pushed upward the stem I28 closes the guideway and prevents discharge through the vent port I3I. When the valve I22 is closed, the pipe I24 is vented but not the pipe I26. When the valve I22 is opened the pipe I24 and also the pipe I26 are subject to starting air pressure arriving fromthe manifold I00. Separate means are provided to vent pipe I26.

The valve housing I2I contains a poppet valve 132 which is urged closed partly by a coil compression spring I33 and partly by supply pressure in the manifold I00. When forced from its seat it admits air from the supply manifold I00 to the pipe I34. The valve I32 has a fluted pilot I35 and below that a cylindrical stem I36 which, when forced upward by the cam follower I31, closes the guide passage and thus disconnects the pipe I 34 from the vent port I 38.

The pipe I34 leads to the lower end. of the housing I39 (Figure 1) beneath a piston. I. This piston Is urged downward by a coil compression spring I42 and functions as a valve. In its lowermost position it interrupts communication between the pipe I34 and a pipe I43 and at the same time connects the pipe I43 with atmosphere by way of the vent port I44 formed in the side of the housing I39.

When the piston MI is forced upward overpowering spring I42, it permits communication between the pipes I34 and I43 and disconnects pipe I 43 from the vent .port I44. The pipe I43 is connected through a check valve I45 with the lower end of cylinder II, i. e., with the working space below the piston 16. The check valve I45 has a small bleed port I46 and the arrangement of parts is such that when the pipe I34 is under pressure It is connected with pipe I43 which pernitlis free flow to the lower end of the cylder.

Conversely, when the pipe I34 is vented to atmosphere by way of port I38 in valve body I2I, the piston I4I descends and serves as an auxiliary vent valve for the lower working space in cylinder-"II. However, exhaust flow is then limited to the rate permitted by the bleed port I46.

With a reversing gear such as that described, with reference to Figure 1, the shaft I6 under both forward and reverse running conditions, has a tendency to turn in a counterclockwise direction (as viewed in Figures 1 and 5). This follows from the fact that in both directions of running the cranks 29 are in the position shown in Figure 1 and there are four such cranks per cylinder, each with a connecting rod such as 21. The effect is to impose a strong counter-clockwise bias on the shaft I6 in both running positions. Consequently, the piston I H is used to operate a latch or detent which is effective to retain the shaft in its reverse running setting (the opposite one from that shown in Figure 1) until pressure is admitted to the pipe I34 for the purpose of shifting the piston II and consequently rotating the shaft I6 counter-clockwise. With the parts in the position of Figure 1, no latch is needed because the piston is forced by the rotary bias of shaft I6 to its uppermost limit of motion and is there retained by the bias of the shaft.

To effect the desired latching action a disk I4! is fixed on the shaft I6 and has a ratchet lug I48 with which a latch I49 pivoted at I5I coacts. The piston I4I is connected by a piston rod I52 and link I 53 with the latch member I49 in such a way that when the piston I4I moves upward, the latch is disengaged from the ratchet lug I48. Thus the latch resists counter-clockwise rotation of the shaft I6 when that shaft is turned to its limiting position clockwise, but is ineffective in the reverse direction.

The mechanism for operating the valves H9 and I2I can now be described.

Splined on the shaft IN is a sleeve I54 and swiveled on this sleeve is a ring I55. The ring I 55 is connected by the radial arms I56 with a sleeve I5'I swiveled on the shaft I58. The sleeve I5! is connected by the arm I59, link I6I and arm I 62 with the shaft I63. Portions of the shaft I63 appear both in Figure 1 and Figure 2. The actual location of the parts I54 to- I63 is clearly shown In Figures 3 and 4.

The shaft I63 carries an arm I64 which has a roller cam follower I65. This roller works in the zig-zag cam slot I66 formed in the lower end of the member II. The parts are so arranged that as the member II descends from the position shown in Figures 1 and.3, the sleeve 2 I54 is moved half its travel to the left; during about one-third of the traverse of the'member II, then dwells, and .then moves the remainder of its travel to the left.

The p p se of this motion is to afford an interlock.

The sleeve I54 carries two reversely arranged 'simiiarcams I61 and I68 which, in Figure 2, are shown more distantly spaced from eachother than they actually are in the commercial device. The true spacing is indicated in Figures 3 and 9.

The cam I61 has an inclined portion I69 so dimensioned that if the shaft IOI 'is turned in As best shown'in Figure 2, the follower I28 is in position to engage the inner edge of the inclined portion I68 of cam I61 and the follower I31 is beyond the outer edge of the cam I88. If, now, the shaft IIII be turned toward the astem rangesrthat is, over away from the observer as viewed in Figure 2, the inclined portion I68 of cam I61 will open the valve I22, admitting air under pressure via pipe I24, check valve I25 and pipe I26, to the space above the piston 16. At this time the valve I32 is closed, pipe I34 is vented, piston I is down, and the space below the piston 16 is vented to atmosphere. Consequently piston 16 will start to move downward.

As it moves downward, the cam I66 will cause the sleeve I54 to shift part way to the left as, viewed in Figure 2, so that cam I68 will now align with follower I31 and follower I29 is still inengagement with cam I61. However, the distance that the operator can rotate the shaft IIJI is limited by collision of the follower I29 with the shoulder "I on cam I61 until the member II completes its excursion, at which time the final movement to the left of the sleeve I54 will carry the cam I81 so far to the left that the shoulder I'II clears the follower I28. The purpose of this is to prevent the operator, acting under the stress of an emergency, from admitting air to the starting headers before the reversing gear can complete its reversing function. Observe, however, that we have just been dealing with an attempt to start the engine astern when the reversing sear is set for forward running.

Assume, now, that the shaft I III is in the position of Figure 2 and that the piston 16 is in its forward running position as shown in Figure 1 and that the operator tries to go to air starting position forward. The follower I31 is beyond the outer edge of the cam I12 and consequently the operator can go directly to air starting position without interference or delay. It will be observed that the two cams are symmetrical and that the cam slot I68 on the member II is symmetrical, so that similar interlocking action is secured in both directions of manipulation.

To analyze the motion, it is necessary to start with the piston 16 in its lowermost position, in which event the sleeve I54 would be in its leftmost position, so that the follower I31 is in the path of its cam and follower I28 is outside the path of its cam.

It will be observed that the check valve I25 prevents exhaust of the pipe I26 through the valve H9 and that the pipe I26 is not provided with any auxiliary exhaust valve, such as the mechanism enclosed in the housing I38 of Figure 1. It is necessary, therefore, to provide means for exhausting the pipe I26 and the space Within cylinder 1I above piston 16. This is afforded by a separate exhaust valve mounted in the casing I14.

A branch of the pipe I26 leads to the casing I14 above the poppet valve I15. This valve has a seating spring I16 and normally closes against flow to an exhaust port I11 but may be forced open by a cam follower I18. This follower is actuated at proper times by a cam I18 fast on the shaft II. The cam is so formed that when the shaft IOI is in its neutral or stop position the valve I15 is closed. It remains closed if the shaft IIJI is swung toward astern operation, but is opened and held open by the cam in all forward running pmitions of shaft IIII.

The sole function of the valve I15 is to vent the pipe I26. A similar cam actuated vent valve, appropriately timed, could be used to vent the pipe I43 and would involve a mere duplication. However, because the valve mechanism in the housing I39 performs the desired function and the added function of operating the latch I48, the illustrated arrangement is preferred.

The pilot valve I8I controls the supply of air to the starting header 53. The pipe 98 already described supplies air to the chamber I82 above an admission and exhaust valve I 83. This valve is normally in its lower position, so that the pipe 96 is connected with the pipe I84, so that the pipe I84 is normally under supply pressure. However, if the cam follower I be forced upward, the valve I83 is shifted upward, entering and thus closing the passage between chamber I82 and pipe I84, thereby cutting off the supply of air to the pipe I84 and at the same time venting that pipe to atmosphere through the vent port I86.

The follower I 85 and also the followers I18, I31 and I29 are provided with feathers to prevent them from rotating in their guides, as is clearly shown in Fig. 2.

The pressure in the pipe I84 controls an admission and exhaust valve which either vents the header 53 or connects it with supply. This valve, as shown in Figure 2, is mounted in the same housing with the valve 82. A piston I81 is urged upward by a spring I88 and is subject on its lower face to the pressure in pipe I84. On its upper face it is subject to supply pressure arriving from chamber 85.

Connected to the piston I 81 is a supply valve I89 having an area smaller than the area of the piston I81 nd controlling communication with a chamber I I connected by pipe I92 with header 53. Thus, if pipe I84 is connected to supply, the fluid pressures acting on piston I81 are equalized and the spring I88, together with supply pressure, holds the valve I88 closed. However, if the pipe I84 be vented to atmosphere, supply pressure acting on the upper side of piston I81, which has a greater area than the valve I89, forces the piston downward and opens the'valve, admitting air from the supplyto the chamber I9I and consequently by way of pipe I92 to the starting header 53.

To vent the starting header a second reversely seated valve I93 is used. This valve has an area less than the effective area of the valve I89. When the valve I89 opens, the valve I93 closes, disconnecting the chamber I 9| from the vent port I94. Similarly, when the valve I89 closes, the vent valve I93 opens, so that the starting header is vented, with the result that the springs 51 shift pistons 66 downward, drawing all the push rods 32 upward to inactive position.

The valve I 8| controls the supply of starting air for both directions of running, and conse quently is operated by two identical cams, one of which functions to start ahead, and the other of which functions to start astern.

Since the maneuvering shaft IIII has to turn beyond the air starting position to a normal operating range, the two cams which operate the follower I85 must pass beyond that follower. While they must operate the valve I8I in motion away from the stop or neutral position, they should not operate it in motion toward the stop or neutral position. Switch cams are used to meet this requirement.

The shaft IIlI carries two arms I95 and I96, each provided with ways parallel with the axis of the shaft IUI. In these Ways on each of the arms is provided a corresponding longitudinally slidable cam block. The arm' I95 carries the cam block I91 and the arm I96 the cam block I98.

These two cam blocks are counterparts of each other, that is, one is right-handed and the other is left-handed. Each has an oblique shoulder indicated with reference to each block at I99. An

explanation of the operation of one cam block- Assume that the shaft IUI is turned in the astern direction of Figure.2 until the cam block I98 enters under the follower I85, forcing it upward. This will admit air to the starting header 53 until the cam block rides under and frees the follower. When it does, the descent of the follower will terminate the supply of air and vent the header 53. Just after the follower I85 is freed, terminating the supply of starting air, the cam I06 will have turned far enough to start the descent of the follower 52 consequently initiating the supply of fuel to the engine.

When the shaft IIlI is turned back toward the neutral position, the follower I85 strikes the inclined shoulderI99 and slides the cam block I98 to the left, so that the follower passes the cam without being lifted. Just before the shaft IUI reaches its neutral or stop position and after the cam block I98 is passed beyond the follower I85, the end of the cam block which is beveled for that purpose as indicated at 20I, strikes a fixed lug 202 mounted on a portion of the frame and restores the cam block to its normal or active position. (See Figure 8.)

To retain the blocks I91 and I98 in their normal or active positions against accidental displacement, an impositive detent illustrated in Figure 7 is used. This comprises a latch'nose 203 urged outward by aspring 204 and'latching impositively into a V-groove'205 cut across the back of the cam block.

The general operation of the device has been traced as the description proceeded, and accordingly it appears unnecessary to set it forth in detail- However, the timing of event with reference to the angular displacement of the shaft IIII in the commercial embodiment of the invention is significant and will be stated.

In that particular embodiment the brake is on in the neutral position and for 16 the shaft IIJI in either direction from such position. The reversing functions take place in angular ranges of 18 measured in each direction from the neutral position, which means that the shoulders HI and I13 engage the cam followers and prevent further motion at 18 from the neutral position in each direction. There is then an idle travel of 5", the admission of starting air occurring in a range lying between 23 and 37. The starting notch or at 33 from the neutral position. Beyond the starting range there is an idlerange of 3 before the supply of fuel commences at 40. The range for adjustment of fuel extends from 40 to giving a 50 range for fuel adjustment. This permits a gradually modulated control. These values are illustrative of good commercial practice.

The invention provides a control in which a controller operates the reversing mechanism in a mid-range and applies an engine brake substantially throughout the entire range .of reversal. The same controller, when moved beyond the reversing range, operates the air starter, and when moved beyond the air starting range operates a fuel controller progressively.

Only one limitation is imposed on the manipulation of this control and that is effective only if the reversing gear must function. In such case the controller is arrested before it enters air starting position but only if the operator tries to shift the controller too fast and then only until the reversing gear has functioned. It is then automatically freed. Thus the controller is freely movable to all positions except under one abnormal condition, occasioned by hasty manipulation.

An important function of the dwell in the cam I66 is to position both cams I61 and. I68 so that their limiting shoulders HI and I13 will function in the event that the piston 16 and the member II stop at part-stroke. For example, if the engineer starts a reversing function and then starts to shift back before the reversing movement is completed, he cannot enter the air starting position in either direction until the reversing mechanism has shifted fully. Because of this dwell, the interlock is made eifective in both directions when, but only when, its functions are required.

As stated, the invention is applicable to a wide range of engines and not merely to that described. Further, an important aspect of the invention is that the maneuvering shaft IIJI and its associated .valve mechanisms may be variously located. The follower 52 has only limited and relatively slow motion. The same is true of the connections between the cam I68 and the sleeve I54. Consequently these connections can assume various forms which will permit the location of the shaft MI in almost any position near the engine that a particular installation may require. What is claimed is:

1. The combination of an internal combustion pressure actuated reverscondition the .engine' for forward and for reverse running; a maneuvering shaft rotatable in each direction from a neutral position; valve means operable to reverse said engine having a fluid ing motor operable to reversing motor; a cam mechanism operable by of rotation of detent is actually located reverse rotations of said shaft from said neutral position and effective in limited reversing ranges, one on each side of said neutral position, to operate said reversing valve means reversely; means for arresting rotation of said shaft at the limit of each reversing range until said reversing motor has responded fully to said valve means; and means operable by rotation of said shaft into ranges beyond said reversing ranges to operate said engine.

2. The combination of an internal combustion engine having a fluid-pressure actuated reversing motor operable to condition the engine for forward and for reverse running and including means to retain it in forward and reverse positions; valve means for reversely actuating said motor comprising normally closed inlet valves each associated with a normally open vent valve so arranged that the opening of an inlet valve entails closure of the related vent valve; a maneuvering shaft rotatable in each direction from a neutral position; a cam mechanism operable by reverse rotations of said shaft from said neutral position. and effective in reversing ranges one on each side of said neutral position to open a corresponding inlet valve, the parts being so arranged that rotation of the shaft beyond said ranges permits closure of the inlet valve so opened; and means operable by rotation of said shaft into ranges beyond said reversing ranges to operate said engine.

3. The combination of an internal combustion engine having a fluid-pressure actuated reversing motor operable to condition the engine for forward and for reverse running, said motor being biased to move in one direction, at least in the forward and reverse positions of the motor; valve means for reversely actuating said motor comprising normally closed inlet valves each associated with a normally open vent valve so arranged that the opening of an inlet valve entails closure of the related vent valve; a maneuvering shaft rotatable in each direction from a neutral position; a cam mechanism operable by reverse rotations of said shaft from said neutral position, and effective in reversing ranges one on each side of said neutral position to open a corresponding inlet valve, the parts being so arranged that rotation of the shaft beyond said ranges permits closure of the inlet valve so opened; means operable by rotation of said shaft into ranges beyond said reversing ranges to operate said engine; a latch serving automatically to latch said motor in one of its limiting positions against motion in response to said bias; and pressure operated latch actuating means responsive to the opening of one of said inlet valves for disengaging said latch.

4. The combination with the structure defined in claim 3 of auxiliary exhaust means for said reversing motor associated'with said latch actuating means and'so arranged that the auxiliary exhaust is opened and the latch is disengaged selectively and in alternation one with the other.

5. The combination of an internal combustion engine having a fluid pressure actuated reversing motor operable to condition the engine for forward and for reverse running; a maneuvering shaft rotatable in each direction from a neutral position; valve means operable to reverse said reversing motor; a cam mechanism operable by reverse rotations of said shaft from said neutral position and effective in limited reversing ranges, one on each side of said neutral position, to operate said reversing valve means reversely; an interlock interposed between said shaft and motor and serving to prevent said shaft from moving beyond the reversing range until the responsive shift of said motor is completed; and means operable by rotation of said shaft into ranges beyond said reversing ranges to operate said engine.

6. The combination defined in claim 5, in which the interlock comprises a, cam-shifting connection between said reversing motor and said cam mechanism so arranged as to limit the motion of the cam mechanism by engagement of the cam with a portion of said reversing valve means until said motor has responded to the actuation of said valve means and has shifted said cam to clear the same.

7. The combination of an internal combustion engine having a fluid-pressure actuated reversing motor operable to condition the engine for forward and for reverse running; valve means for reversing actuating said motor comprising normally closed inlet valves each associated with a normally open vent valve so arranged that the opening of an inlet valve entails closure of the related vent valve; a maneuvering shaft rotatable in each direction from a neutral position; a cam mechanism operable by reverse rotations of said shaft from said neutral position, and effective in reversing ranges one on each side of said neutral position to open a corresponding inlet valve, the parts being so arranged that rotation of the shaft beyond said ranges 'permits closure of the inlet valve so opened; an interlock interposed between said shaft and motor and serving to prevent said shaft from moving beyond the reversing range until the responsive shift of said motor is completed; and means operable by rotation of said shaft into ranges beyond said reversing ranges to operate said engine.

8. The combination defined in claim 5 in which the interlock is so contrived that when the motor is in positions intermediate forward and reverse positions the interlock inhibits rotation of the maneuvering shaft beyond both reversing ranges, and in the two limiting positions of the motor permits motion of the shaft beyond one corresponding reversing range while inhibiting motion beyond the other range.

9. The combination defined in claim 7 in which the interlock is so contrived that when the motor i in positions intermediate forward and reverse positions the interlock inhibits rotation of the maneuvering shaft beyond both reversing ranges, and in the two limiting positions of the motor permits motion of the shaft beyond one corresponding reversing range while inhibiting motion beyond the other range.

10. The combination of an internal combustion engine having an air starting mechanism adapted to be rendered active by the supply of compressed air thereto and having a fluid pressure actuated reversing motor operable to condition the engine for forward and for reverse running; a maneu vering shaft rotatable in each direction from a neutral position; valve means operable to reverse said reversing motor; a cam mechanism operable by reverse rotation of said shaft from said neutral position and effective in limited reversing ranges, one on each side of said neutral position,

to operate said reversing valve means reversely;

an interlock interposed between said shaft and motor and serving to prevent said shaft from moving beyond the reversing range until the responsive shift of said motor is completed; air valve means for supplying compressed air to said starting mechanism; means whereby said shaft opens and then closes the air valve means just mentioned as the shaft turns beyond each reversing range; means for inhibiting the opening of the air valve means on motion of the shaft toward neutral position; and means operated by the shaft in motion ranges reached after said air valve means has closed and serving to vary progressively the fuel feed to the engine.

11. The combination of an internal combustion engine having a fluid pressure actuated reversing motor operable to set the engine for forward and for reverse running; a fluid pressure brake operable to arrest motion of the engine; a maneuvering shaft rotatable in each direction from a neutral position; a brake controlling cam operable by said shaft; a brake valve operable by said brake controlling cam to apply the brake when the shaft is within the reversing ranges hereinafter specified; valve means operable to reverse said reversing motor; a cam mechanism operable by reverse rotation of said shaft and efiective in limited reversing ranges, one on each side of said neutral position to operate said reversing valve means reversely; and an interlock between said shaft and motor, serving to prevent said shaft from turning beyond a reversing range until a responsive shift of said motor has been completed.

12. The combination of an internal combustion engine having an air starting mechanism adapted to be rendered active by the supply of compressed air thereto; and having afluid pressure actuated reversing motor operable to condition the engine for forward and reverse running both as to air starting, and as to internal combustion opera tion; a maneuvering shaft rotatable in each direction from a neutral position; valve means operable to reverse said reversing motor; a cam mechanism operable by reverse rotation of said shaft and effective in limited reversing ranges one on each side of said neutral position, to operate said reversing valve means reversely; an interlock between said shaft and motor and serving to prevent said shaft from turning beyond a reversing range until a responsive shift of said motor is completed; air valve means for supplying compressed air to said starting mechanism; means whereby said shaft opens and then closes the air valve means just mentioned as the shaft turns beyond each reversing range; means for inhibiting opening of the air valve means on motion of the shaft toward neutral position; and means whereby the shaft exerts a control on fuel supplied to the engine and serves to increase the fuel supplied in motion ranges reached after said air valve means is closed.

13. The combination of an internal combustion engine having an air starting mechanism adapted to be rendered active by the supply of compressed air thereto, and having a. fluid pressure actuated reversing motor operable to condition the engine for forward and reverse running both as to air starting, and as to internal combustion operation; a fluid pressure brake operable to arrest motion of the engine; a maneuvering shaft rotatable in each direction from a neutral position; a cam operable by said shaft; a brake valve operable by said cam to apply the brake at least when the shaft is in said neutral position; valve means operable to reverse said reversing motor; a cam mechanism operable byreverse rotation of said shaft and effective in limited reversing for inhibiting opening of the air valve means on motion of the shaft toward neutral position; and means whereby the shaft exerts a control on fuel supplied to the engine and serves to increase the fuel supplied in motion ranges reached after said air valve means is closed.

14. The combination of an engine having a reversing motor operable in reverse directions to set the engine for forward running and for reverse running; a maneuvering shaft having a neutral position; valve means operable by reverse movements of said shaft within limited reverse ranges on each side of said neutral position to operate said reversing motor reversely; an interlock between said reversing motor and said maneuvering shaft, saidinterlock permitting free motion of said shaft throughout said reversing ranges but serving to prevent motion of the shaft in each direction beyond such ranges until said motor has fully responded; an air starting mechanism for said engine arranged to be set for reverse operations by said reversingimotor and adapted to be rendered active by the supply of starting air to said starting mechanism; valve means arranged normally to out off said supply of air; a cam follower operable to cause said valve means to supply air to said starting mechanism; a pair of cams carried by said shaft and each arranged to actuate said follower to establish and then interrupt such supply as the maneuverin shaft moves away from said neu 'tral position beyond a corresponding reversing range; and means rendered effective by return motion of said shaft toward said neutral position to render that cam which has operated the follower, ineflective to operate the follower during the return movement.

15. The combination of an engine having a reversing motor operable in reverse directions to, set the engine for forward running and for reverse running; a maneuvering shaft having a neutral position; valve means operable by reverse movements of said shaft within limited reverse ranges on each side of said neutral position to operate said reversing motor reversely; an air starting mechanism for said engine arranged to be set for reverse operations by said reversing motor and adapted to be rendered active by the supply of starting air to said starting mechanism; valve means arranged normally to cut of! said supply of air; a cam follower operable to cause said valve means to supply air to said starting mechanism; a pair of cam carriers mounted on said shaft; a pair of cams, one movably mounted in each of said carriers, each having a normal position in which, upon motion of the shaft away from said neutral position, the cam serves to actuate said follower to establish and then interrupt such supply of air; and positively acting switching means rendered effective by return motion of said shaft toward said neutral position to force said cam to an inactive position and then as the shaft nears neutral position, restore it to active position.

16. The combination of a valve biased to close and operable to supply starting air to an engine; a maneuvering shaft having a neutral position; a cam shiftably mounted on said shaft and arranged to open the said valve to supply starting air as said shaft is moved away from said neutral position, and then free the valve to permit it to close; and positively acting switch means rendered effective by return motion of said shaft toward said neutral position to shift said cam out of coactive relation with said valve and then positively restore the cam to active position.

17. The combination of an air starting valve; a cam follower operable to actuate said valve; a maneuvering shaft having a neutral position from which it is rotatable in opposite directions; a pair of cams shiftably mounted on said shaft and normally positioned to actuate said follower selectively and then release the follower as the maneuvering shaft is reversely rotated from its neutral position; a switch surface formed on each cam and arranged to coact with the fol-- lower as the shaft thereafter is turned back toward neutral position, to shift the cam while the follower remains inert; and means effective substantially as the maneuvering shaft reaches neutral position to shift said cam back to its normal position.

18. The combination of an air starting valve; a cam follower operable to actuate said valve; a maneuvering shaft having a neutral position from which it is rotatable in opposite directions; a pair of cams shiftably mounted on said shaft and normally positioned to actuate said follower selectively and then release the follower as the maneuvering shaft is rotated reversely from its neutral position; a switching surface formed on each cam and arranged to coact with the follower as the shaft thereafter is turned back to ward neutral position, to shift the cam while the follower remains inert; means effective substantially as the maneuvering shaft reaches neutral position to shift said cam back to its normal position; and impositive detents for retaining said cams in their normal positions.

19. The combination of an internal combustion engine having a fluid pressure actuated reversing motor operable to condition the engine for forward and reverse running and including means for retaining said motor in its forward and in its reverse running positions; valve means for reversely actuating said motor and comprising normally closed inlet valves each associated with a normally open vent valve so arranged that opening of an inlet valve entails closure of the related vent valve; a maneuvering shaft rotatable in each direction from a neutral position, such motion including reversing ranges on opposite sides of such neutral position; a mechanism operable by reverse rotations of said shaft within said reversing ranges to open according to the direction of rotation from neutral position a selected inlet valve, the parts being so arranged that rotation of the shaft beyond the reversing ranges permits closure of the inlet valve previously opened; means for preventing the operation of said reversing shaft beyond said reversing ranges until said motor has completed its responsive motion; and means operable by rotation of said shaft into ranges beyond said reversing ranges to operate said engine.

20. The combination of an internal combustion engine having a fluid pressure actuated reversing motor operable to condition the engine for forward and reverse running and including means for retaining said motor in its forward and in its reverse running positions; valve means for reversely actuating said motor and comprising normally closed inlet valves each associated with a normally open vent valve so arranged that opening of an inlet valve entails closure of the related vent valve; a maneuvering shaft rotatable in each direction from a neutral position, such motion including reversing ranges on opposite sides.

of such neutral position; a mechanism operable by reverse rotations of said shaft withinsaid reversing ranges to open according to the direction of rotation from neutral position a selected inlet valve, the parts being so arranged that rotation of the shaft beyond the reversing ranges permits closure of the inlet valve previously opened; means for preventing the operation of said reversing shaft beyond said reversing ranges until said motor has completed its responsive motion; and means operable by rotation of said shaft into a starting range and a distinct operating range each beyond said reversing ranges and each distinct from the other to operate said engine by pressure fluid and by the injection of fuel.

GEORGE E. RAMSTAD.

CERTIFICATE OF CORRECTION.

Patent No. 2,215,885 June 5, 19in.

GEORGE E. RAMSTAD. It is hereby certified that error appears inthe printed specification of the above numbered patent requiring correction as follows: Page 8, sec- 0nd column, line 22, claim 7, for the word "reversing" read --reversely-, page 10, first column, line 20, claim 17, for "switch" read "switching"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of July, A. D. 191 1.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents.

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