US2117852A - Hydraulically operated reversing mechanism - Google Patents

Description

f yMay 17, 193s.

w. J. PEARMAIN HDRAULICALLY O/PERATED REVERSING MECHANISM ined N0v..18, 1955 7 sheets-sheet 1 May 17, 1938. w. J'. PEARMAIN 2,117,852

HYDRULICALLY CPERTED REVERSING MECHANISM Filed Nov. 18, 1935 '7 Shef'bS-Sheet 2 I May 17,11938. w. .LPEARMAIN 4' 2,117,852

HYDRAULICALLY OPERATED REVERS ING MECHANISM Filed Nov. 18,1935 '7 SheebS-Shee'b 5 May 1 7, 1938. w. J. PEARMAIN 2,117,852

HYDRAULICALLY OPERTED REVERSING MECHANISM Filed Nov. 18, 1935 7 Sheets-Sheet 4 May 17, 1938. I w J, PEARMMN 2,117,852

HYDRAULICALLY OPERATED EVERSING MECHANISM Filed-Nov. 18; 1955 7 :amas-sheetl 5 May.17, 1938. w. J. PEARMIN 2,117,852

l HYDRAULICALLY OPERA'ED REVERSING MEGHANISM Filed Nov. 18, 1935 7 Sheets-Sheet 6 Patented May 17, 1938 PATENT `OFFICE mmmomy oPEnArEo nsvsnsnvc nmonmsm william J. Femm. mme, wis., asumir to Twin Diso Clutch Company, Bac

ine, Wis., a

corporation of Wisconsin Application .November 13, 1935, Serial No.. &2?!

My invention relatesto a. reversing mechanism provided with an improved clutch device and actuating means therefor for effecting a transmission of power between driving and driven shafts and is more particularlyconcerned with a mechanism of this character for marine service.

ln marine power installations, particularly those employing internal combustion engines, it is necessary to step down the revolution speed of the engine to a point that is satisfactory for the eiilclent operation of the propeller. Ordinarily this reductionls effected through a sultable arrangement of gearing which includes a reversing device. The reduction features ci this invention, however, may be omitted wherever desired, as it simply constitutes an ancillary phase oi my improved device.

Se i'ar as the arrangement ofgears and reversing clutches is concerned, the disclosure ci the present application is substantially identical with those ci my eopending applications, Serial Nos. 70;?,093 and 720,677, led January it, lille, end April lt, lg3d, respectively. ln each of these mechanisms,v however, the spring-actuated clutches were engaged and disengaged hy manual operation, but this arrangement ls satisfactory for high capacity units, because of the hand eiort required.

lt is therefore one object of my invention to provide a hydraulically operated reversing :mechu anism in whichthe control ls manual and the reversing clutches are thrown into and out or engagement hy hydraulic pressure established by a pump' connected to the principal shaft oi the mechanism which is driven by the main power source.

A further object is to devise a mechanism ot' the character indicated which is sell-contained in respect of lubrication and in which the lubri eating oil is pumped through o. circuit arranged to accommodate the lubricating requirements ci the mechanism and which includes devices that are actuable by the oil pressure to operate the reversing clutches.

These and further objects oi my invention will be set forth in the following specication, reiference being had to the accompanying drawings, and the novel means 'cy which said objects are ericctuated will ce denitely pointed out in the claims.

ln vthe drawings:

Figure l is anend View of the mechanism, as

viewed inthe direction ofthe arrow'i in Fig. 2.

Fig. 2 is a sectional elevation taken along the line 2 2 in Fig. l, looking in the direction of the (ci. lcs-sv) arrows, the clutch actuating mechanism -being illustrated in neutral position.

Fig. 3 is an enlarged sectional view, corresponding to a portion of Fig. 2, showing the reversing clutches in neutral position and the manually controlled, hydraulically actuated mechanism for operating the clutches;

Fig. 4 is a view similar to Fig. 3, but showing the hydraulic mechanism shifted to a position for Yengaging the forward drive clutch.

Fig. 5 is an enlarged, sectional elevation of the oil pump, as viewed in Fig. 2.

Figs. c, 7 and t are sections along the lines 6 6, l--l and in Eig. 5, looking in the direction of the arrows, and uw in detail, structural features oi the oil pump.

Fig. s is a sectional view taken along the line in Fig. d, looking in the direction ci the arrows, and showing the port plate for the oil pump.

rug. io is c. plus new, partly in section, of the reciprocating valve for the hydraulic mechanism, as viewed in the direction of the arrow lll in Fig. 3, the hydraulic cylinder of the hydraulic mechanl and the oil pump being shown in simple plan view beneath the valve.

Fig. ll is a diagrammatic view, partly in section, showing the oil circuit which is utilized to lullricate the mechanism and which forms an important part ci the hydraulic control therefor.

Referring to 2 and 3, the numeral ill designates a it which may be considered as the main power source und which has a flywheel il attached 4to the end thereof. The flywheel has holted to its right face, as viewed in Fig. 2, an internally toothed ring lil which meshes and therefore has driving connection with a similarly toothed spider it that is mounted on the left extremity oi' a. driving shaft it and rotates therewith. iler the purpose oi description, the shaft it will he regarded as the driving shaft of the reversing mechanism. This shaft extends across the interior ol. housing it and it is intermediately provided with an enlarged, splined portion it (see Fig. 3l which has fitted thereon a pair oi drums'll and. iti whose open ends 'ia-ce in opwlsite directions. These drums are fastened together by screws it in order to provide common, shiitalole member which is adapted for axial movement along the portion lll, but partalres of the rotary movement of the shaft it.

The drum il carries e. plurality of iixeddiscs til 'which are arranged in alternating relation to a piuralityof similar disks il supported on a huh 22. This huh is provided with an annular,

ange-like portion 22a between which and the opposite face of the drum I l', the discs 20 and' 2I are adapted to be clamped in order to provide the forward drive clutch of the mechanism. The hub 22 is freely rotatable at its right end on a ball bearing 23 and adjacent the splined portion I6 upon a ball bearing 24, the inner races of the bearings 23 and 24 tting closely the adjacent portions of the shaft I4. Adjacent the bearing 23, the periphery of the hub 22 is formed as a pinion 25 by directly cutting the teeth thereon, or a separate vpinion may be keyed or otherwise secured to the hub 22. The pinion 25 (see Fig. 2) meshes permanently with an internal gear 2t that is fastened to a driven shaft 2 which projects without the housing l5 and may be suitably' connected to a propeller or other type of shaft. As shown in Fig. 2, the pinion 25 is disposed above, or to one side of, the axis of the shaft 2T, thereby providing space for an additional pinion to transmit a reversing drive to the shaft 2l, as hereinafter described.

A thrust bearing 23 encircles the hub 22 with its inner race iitting closely around the hub and abutting against a shoulder 28a provided thereon. The outer race of the same bearing is rredly retained Within a cage 29 that is provided on a web Sil which extends upwardly from the bottom of the housing l5. The bearing 2d, therefore, not only resists a portion of the thrust of the mechanism during direct drive, but it also operates as a support for the right end of the driving shaft i4, the support operating through the hub 22 and the bearings 23 and 2li.

The drum i8 also supports a plurality of friction discs 3l which are arranged in alternating relation to a plurality ofl friction discs 32 that are carried by a hub it and these last named discs are adapted to be clamped between an annular iiange 33B' provided on the hub 33 and the adjacent face of the hub lil, thus constituting the reversing clutch of the mechanism. ls with the direct drive clutch, the hub 33 is freely rotatable upon the outer races of ball bearings Sid and 35, Whose inner races snugly t the shaft lil. A pinion is xedly mounted on the hub @il so as to rotate therewith and this end of the shaft Eil is sup`a ported by means of a thrust bearing 371, similar to the bearing 23, whose inner race snugly ts the periphery of the hub t@ and abats against a shoulder 37a provided on the same hub. The outer race of the same bearing is iixedly retained within a cage 38 forming a part of a web 3S which extends upwardly from the bottom of the housing I5. The bearing Eil serves as'fa support for the left end of the driving shaft lli, in'addition to taking a portion of the thrust of the mechanism during reverse drive.

The pinion 36 is in constant mesh with a gear 4@ xedy attached to one end of a counter-shaft il that is rotatably mounted in bearings d2 and 43 that are carried in the webs 3@ and 3S, respectively. The opposite end of the shaft 4i has iixedly connected thereto a pinion 4d that is in permanent mesh with the internal gear 26 and located on the opposite side of the axis of the shaft 21 from the pinion 25.

The inner race of a ball bearing 45 is clamped between the adjacent faces of the drums il and I8 by the screws I9 (see Fig. 3) and encircling and xedly connected to the outer race-of the same bearing is a yoke 46 which is provided with a pair oi?` laterally extended trunnions 4l which project from opposite sides thereof (see Fig. 1). A pair of arms 48 are pivotally mounted on the trunnions 41. respectively, and the lower end of each arm is bifurcated as at 4l! to embrace a block Sli that is freely rockable on a pin 5I, the latter being conveniently mounted in the wall of the housing. The upper ends of the arms 48 are pivotally connected to stub arms 52, respectively, which project laterally in opposite directions from a link $3 (see Fig. 3) whose movements to and fro, as hereinafter described, eiects a rocking of the arms 48 on their respective pivots to thereby throw either of the aforesaid clutches into engagement. In the relative positions shown in Fig. 3, these clutches occupy neutral or nondriving positions.

The foregoing structural features of the forward and reverse drive clutches and the asso-1 elated gearing are substantially identical with those disclosed and claimed in the aforesaid pending applications. The present invention essentially diers from the latter in the hydraulic gear provided for actuating the clutches and this mechanism will now be described.

Referring to Figs. 2, 5, 6 and '7, the left end 54 of the housing l5, as viewed in Fig. 2, is counter bored where the shaft lll extends therethrough and a closure plate 55 is seated in the bottom of this counterbore. A. pump chamber ring 5t is also closely iitted in the counterbore and is pinned to the ring 55. The 'inner diameter of the ring 5t is somewhat greater than the diameter of the shaft lil and the bore of the ring is eccentrically located with respect to the shaft, the center oi the bore being located a short distance below the center of the shaft,'as clearly .indicated in Fig. 7, for a. purpose hereinafter explained. A pump rotor 5l is drivably connected to the shaft I4 and the left face thereof, as viewed in Fig. 5, closely' ts the adjacent face oi the ring 55.

A plurality of radial slots 53 are cut inwardly from the peripheral face of the rotor iii and a vane 5d is freely slidable in each of these slots, so that when the pump rotor is operating, each o the varies will be moved outwardly into contact with the bore of the chamber ring lit. As clearly indicated in Fig. 7, the eccentricity of the bore of the ring et, in conjunction with the pump rotor, defines suction and delivery chambers t@ and (il, respectively. The chamber @E is in communication with an intermediate chamber 62 having the parti-annular shape indicated in Fig.' 6 and which is located in a cover plate @3 that is securely held to the housing end 54, the pump rotor operating between this cover plate and the ring 55. The intermediate chamber t2 communicates through a suction port 54, also formed in the cover plate t3, and one end rof a suction pipe GE is in communication with this port, the opposite end of the pipe terminating in thev lower end of the housing l5 and specifically in a reservoir por tion thereof, as hereinafter described.

The delivery chamber 6I of the pump communicates with a second intermediate chamber 66, also of parti-annular shape as indicated in Fig. 6, and which is also formed in the cover plate $3. |li'he chamber 66 communicates with a delivery port El' within which is mounted one end of a delivery pipe 68 whose opposite end is mounted in the wall of a valve housing 69 so as to deliver iiuid into the interior of this housing. (See Fig, 10.)

A piston valve 'l0 is reciprocably mounted in the housing B9 and is provided with piston portions liand I2 which are spaced and connected by a-neclr 13 that defines with the valve housing a receiving chamber 74 which is in communication with the delivery end of the pipe 68. As illustrated in Fig. 3, the piston valve l is occupying ,a neutral position and completely masks ports lthe extremity of the rod has aiiixed thereto a connector part 8|A which is pivotally attached to the adjacent end of the link 53 so that, when the piston 18 is moved in either direction, a corresponding rocking movement of the levers H8 is effected.

One end of a link 82 is also pivctally connected to the part 8| and one end of a link 83 is pivotally connected to an intermediate portion yof the link 82, and the opposite end of the link 83 is pivoted in the valve rod 84. The other end of the link 82 is pivotally connected to one end of a link 85 and the opposite end of the latter link is pivotally connected to a lever 86 that is fixedly mounted on a rock shaft 81 suitably journaled in the housing I and which extends outwardly thereof for aixation to an operating handle 88. Accordingly, when the handle 86 is rocked forwardly or rearwardly, or toward the left or right, respectively, as viewed in Fig. 2, the piston valve 'Hl will be moved accordingly, but without moving the piston lt.

Referring to Fig. 10, the exhaust of the iluid chamber 'M is provided by a port 89 formed in the wall of the valve housing and which terminates in a valve seat 90 that is adapted to be engaged and to thereby close the port t9 by a valve 9i. rll'his valve operates in a housing extension 92 .Whose open end is closed by a plug d3. An adjusting screw at is threaded through theplug @i and the inner end thereof engages a spring plate di?. One end of a coil spring il@ bears against the plate [iii and the opposite end against the valve iii. By suitably choosing the spring @it and appropriately adjusting lthe screw 9d; any desired pressure may be set up in the yvalve di ,and when this pressure is exceeded by a rise in pressure in the fluid chamber it, iluid will escape through the port t@ into an exhaust pipe iii, one end of which is mounted in the housing extension 32 and is in communication with the interior thereof.

The exhaust pipe di passes through a wall of the housing it and thence through a cooler 9d of any appropriate design and through which cooling. water may be circulated by ineans of the pipes 99.. A return pipe Hilti leads from the cooler @il and its delivery end is mounted in the cover plate ti'and is in communication with a port tdi, also provided in this plate (see Figs. 5 and 6). Fluid passing through the port Mii is discharged intoan annular chamber lili, also provided in the cover plate, and which encii'cles the driving shaft itl (see Figs. 5 and 6). i radial passage it@ is drilled in the shaft iti, the outer end oi this passage registering with the chamber tilt? and the inner end with an axial hole idf-i that extends the length of the driving shaft iii.

The left end of the passage'iili is` closed by a plug itil), so that iluidintroduced into the passage must move toward the right. Similar radial passages lil and till! are provided in the driving shaft, the inner ends of these passages being in `communication with the arial passage Miti and the outer ends registering with passages idd and lila provided in the hubs t3 and 22, all respectively. lBy this means, it is possible to deliver lubricating oil, which is the uid employed to operate the hydraulic gear above described, between the faces of the clutch discs when-they are inthe separated condition illustrated in Fig. 3,`

or when either clutch is disengaged.

The axial hole |05 continues to the right extremity of the driving shaft, so that the lubricating oil may be thrown from ther end I I0 thereof onto the internal gear 2t. The oil which escapes from the end of the driving shaft ultimately is collected in a reservoir iii provided in the bottom of the housing i5 and free movement of this oil from the ends of the housing through the webs 39 and 30 is permitted by passages H2 and H3, respectively.

The operation of my improved reversing mechanism will now be described.y Referring to Figs.

2, 3 and 4, it Will be assumed that the shaft i0 is rotating at some determined speed, which rotation is in turn transmitted to the driving shaft I4 by the spider i3, and that the shifting arms 4B occupy the neutral position shown in Fig. 3. In this position of the-indicated parts, it will be noted that, while the clutch drums il and i8 are rotating with the shaft N, the shifting arms 48 and the parts which operate the same permit this rotation by reason of the association of the yoke it with the outer race of the ball bearing 65.

If now itis desired to transmit a direct or forward drive to the driven shaft 2l, the hand lever 88 will be rocked toward the left, as viewed in Fig. 2, which movement would be forward'with respect to the position of the reversing mechanism in a boat, for example. This movement of the lever 83 will accordingly shift the piston valve 'it toward the left, as viewed in Fig. 3, and substantially to the dotted position indicated in Fig. i, the intermediate linkage also assuming the dotted position shown in the same iigure. cause of the pivotal connection of the link d2 with the part di, the aforesaid movement oi the hand lever d@ does not aiiect the piston it.

The piston valve iii being shifted toward the left, as just stated, the piston portions it and iii uncover the ports i5 and it, respectively, so that oil under pressure as established by the pump rotor el] will pass through .the connecting pip'e, ports and passagesinto the duid chamber llt' and thence through the port iii into the chamber itil to the leit oi the piston liti. lit wiil be understood that up until the time that the piston valve 'itl is shifted, lubricating oil is being raised through the pipe te by the oil pump and then delivered to the pipe titi, from which it passes through the duid chamber 'it in the valve housing tit and, be-n cause of the pressure established, the valve @i is unseated, thus permitting the uninterrupted dow oi the oil through the pipe ill?, cooler 9d, pipe it@ and thencethrough the axial passage it@ to the internal gear it, and then to the .reservoir i il i However, when the piston valve l@ is shifted toward the left, a relief ior this oil ow'is perinitted 'oy the passage oi the oil into the chamber iii and the ensuing reduction in oil pressure on the valve iii either permits this valve to close entirely or to partially close, dependent upon the setting of the spring tit.

The oil that is delivered into the chamber iifi moves the piston 'it toward the right, as viewed in Fig. 3, thereby throwing the shifting arms tid in the same direction and throwing into engagement the forward drive clutch by compressing the friction discs iii and 2i between the drum il' and the hub ange iin.

With the forward drive clutch in engagement, the drive from the shaft it is transmitted through the ywheel Il, spider I3, driving shaft I4, the right hand or forward drive clutch comprising the drum l1, friction discs 2li and 2l and hub 22, which in the present instance also in chicles the diivingpinion 25 that is in mesh with the internal gear 26 and thence to the driven shaft 21.

The piston 18 is moved toward the right by the oil pressure until the forward drive clutch is deflnitely in engagement and, at this time, the positions of thepiston, piston valve and associated linkage is substantially as indicated hy full lines in Fig. fi. In other words, the shifting of the piston it has also occasioned a slight return of the piston valve toward the right, as viewed in Fig. 4, from the dotted line position to which the piston valve had been originally moved loy the hand lever 8&3. However, this relocating of the piston valve is not sumcient to rnaslf` the ports 'i5 and lil, so that oil under pressure is maintained in the chamber l it in order to continue the engagement of the forward drive clutch. After the required pressure has been established in the chamber lill, any excess in oil pressure that may he established by the oil pump will be relieved through the re lief valve il and the oil then passing through the port 89 will complete the circuit as hereinloefore described. Moreover, any oil that may have originally been in the'chamber IE5 to the right of the piston it, es viewed in Fig. 3, will he exhausted through the port it and then through the open end il@ of the valve housing 5s. Oil escaping through the indicated openings simply drips over the mechanism beneath and is finally collected in the reservoir ill.

lf now it is desired to reverse the drive to the mechanism, the operating handle te will he rocked toward the right, as viewed in Fig. 2 to thereby move, through the associated linkage, the piston valve l@ toward the richt, as viewed in Figs. 3 and 4i, and. substantially to a position at the opposite end of the housing corresponding to that indicated in dotted lines in Fig. t. 'During this movement, the chamber lii will loe placed in communication with oil under pressure in the chamber ifi through the port lt, while the cham" her l ifi will he opened to the exhaust through the port le, es permitted hy the open end lll et the left end of the housing @it In other words, the valve position will he exactly the reverse of that hereinhefore described.

Accordingly, the piston 'le will he moved. toward the left, as viewed in Fig. 3, and any oil that may he in the chamber Ele will he exhausted as aforesaid. The shifting arms itfwill accordingly he rocked toward the left, as viewed in Fig. 3, thus throwing into engagement the reversing clutch, as formed hy the drum iii, friction discs Si and '22 and the hub iiange 33e.

The reverse drive will then occur through the following ports: The ywheel ll, spider i3, driving shaft it, reversing or left hand clutch, pinion 36, gear tu, counter-shaft Lil, pinion (it, and then through the internal gear it to the driven shaft 2l.

Any iubricating oil that is not exhausted through the openings llt or lil, dependent upon the direction ofdrive, is finally exhausted through the relief valve 9i, pipe el, cooler 98, and return pipe itil, for final passage through the axial hole I Min the driving shaft. As before stated, some of the oil passing through this hole in the driving shaft is sprayed onto the friction discs, while the remainder passes through the end of the shaft and is sprayed onto the internal gear for final collection in the reservoir l l I.

It will be understood that the nature of -the linkage connection between the piston valve I and the piston rod 19, in conjunction with the movement of the operating lever 8B, is such, that when the operating handle is moved from the forward drive position illustrated in Fig. 4 to the lneutral position illustrated in Fig. 3, the piston valve l0 will be moved to a position such that the piston portion l2 thereof will communicate the chamber HE with the fluid chamber lll through the port lt and will communicate the chamber lit with the exhaust opening lll through the port l5. Oil pressure will accordingly move the piston lil toward the left, as viewed in Fig. 3, and, during this movement, the piston valve 'lll-is slow'- ly movedto the masking position, illustrated in Fig. 3, whereupon the indicated movement of the piston 'lil will cesse and the piston will then occupy the position shown in Fig. 3. A similar movenient occurs when the operating handle is moved from a reverse position to the neutral position.

lin order to insure adequate lubrication of the pump rotor and the free and positive movement of the venes 59 in their slots, angularly inclined oil passages llt (see Figs. 8 and 9) communicate the intermediate chambers t2 and 66 with partiennular grooves l i9 and l2@ provided in the face of the cover plate ed. The grooves il@ and i2!) are located in a position such that they substantially register with the inner ends of the slots 58 (see Fig. and. hence oil under pressure maintalus the outward position of the varies, thus avoiding any necessity for springs.

ln the event of the installation of these mech. anisins in craft. provided with twin screws and eccorly with propeller shafts running in opposite directions, the suction and delivery pipes and e@ would oe reversed from the positions indicated in Fig. 3, according to the direction of rotation of the shaft of the engine to which the particules reversing mechanism is connected.

lf the hydraulic gear shouid fail for any reason, it is still possible to operate the mechanism for forward drive lov virtue-of the loar lil which is thresded through en end well E22 of the housing. ns illustrsted in Fig. 2, this har is shown as unconnected to the linlr. 53 and this arrangement is normal, so long as the hydraulic gear is functioning. In the event of a failur of the latter, however, the linlr 53 is disconn ed from the part di and is connected to the adjacent end of the har lil. If the nut i255 is then backed off sufliciently, rotation of the nut i211 will serve to pull the har liil toward the right and hence throw the forward drive clutch into engagement.

A reversing mechanism of the character indicated above-xnay he huilt for use in installations requiring high capacity, because the operating eort required to octuate the forward andreverse clutches is provided by the operation of the mechanism itself through the medium of oil pressure. Moreover, this pressure is created by the use of a medium which is in turn utilized to lubri- -cate the mechanism as a whole, so that the latter is a fully self-contained unit( g I claim: "Y

1. In a. reversing mechanism, the combination of a driving shaft, a pair of gears freely rotatable on the shaft, clutches for positively driving either of the gears, a member shiftable to engage either clutch, and. hydraulic means for shifting the member comprising a cylinder, a. double-acting piston operating in the cylinder and connected of a housing having an'oil reservoir, a driving' to the member, a manually controlled valve for admitting fluid to either end of the cylinder, a

pump driven by the shaft, and a pipe connecting the pmp and valve for delivering fluid under pressure to the cylinder.

2. In a reversing mechanism, the combination of a driving shaft, a pair of gears freely rotatable on the shaft, clutches for positively driving either of the gears, a member shiftable to engage either clutch, and hydraulic means for shifting the member comprising a cylinder, a double-acting piston operating in the -cylinder and connected to the member, a manually controlled valve for admitting fluid to either end of the cylinder, a.-

pump driven by the shaft, a pipe connecting the pump and valve for delivering fluid under pressure to the cylinder, and a release valve in comy munication with the admission valve adapted to maintain a constant pressure in the pipe leading from the pump to the valve.

3. In a reversing mechanism, the combination of a driving shaft,` a pair of gears freely rotatable on the shaft, clutches for positively driving either of the gears, a member shiftable to engage either clutch, and hydraulic means for shifting the member comprising a `cylinder having a port adjacent each end, a double-acting piston operating in the lcylinder and connected to the member, a reciprocableA valve adapted to mask the ports when in neutral position and shiftable to open the ports to the incoming fluid and exhaust, respectively, a pump driven by the shaft, and a pipe connecting the pump and valve for 'delivering fluid under pressure thereto.

4. In a reversing mechanism, the combination of a driving shaft, a pair of gears freely rotatable on the shaft, clutches for positively driving either of the gears, a member shiftable to engage either clutch, and hydraulic means for shifting the member comprising a cylinder hav'- ing a port adjacent eachA end, a double-actin piston operating in the cylinder and connecte to the member, a manually controlled, reciprocable .valve adapted to mask the ports when in neutral position and shiftable to open the ports Ato the incoming iluid and exhaust, respectively, a connection between the valve and piston constructed and' arranged to provide for manual actuation of the valve in either direction independently of the piston and an automatic shifting of the valve whenthe piston is subjected to pressure, a pump driven by the shaft, and a pipe connectingthe pump and valve for delivering fluid under pressure thereto.

5. In a reversing mechanism, the combination of a housing having an oil reservoir, a driving shaft in the housing, a pair of gears freely rotatable on the shaft, clutches for .positively driving eitherof the gears, a member shiftable to Aengage either clutch, a hydraulically actuated -necting the reservoir and pump,4 and means for returning fluid from the device to the reservoir. 6. In a reversing mechanism. the combination shaft in the housing, a pair of gears freely rotatable' on the shaft, clutches for positively driving either of the gears, a member shiftable to engage either clutch, and hydraulic means for shifting the member comprising a cylinder having a port adjacent each end, a double-acting piston operating in the cylinder and connected to thev member, a manually controlled, reciprocable valve adapted to mask the ports when in neutral position and shiftable to open the ports to the incoming fluid and exhaust, respectively, a pump driven by the shaft, a suction pipe connecting the reservoir and pump, a delivery pipe connecting the pumpand valve, and means for returning Vthe fluid from the cylinderto the reservoir.

7. In a reversing mechanism, the combination of a housing having an oil reservoir, a driving shaft in the housing' having an axial oil passage and radial oil passages extending therefrom, a pair of gears freely rotatable on the shaft, clutches for positively driving either of the gears, a kmember shiftable to engage either clutch, and hydraulic means for 'shifting the member comprising a cylinder having a port adjacent each end thereof, a manually controlled, reciprocable valve adapted to mask the ports when in neutral position and shiftable to open the ports to the incoming oil and exhaust, respectively, a pump housing encircling the shaft and having suction and delivery chambers, a pumping element driven by the shaft within the housing, a suction pipe connecting the reservoir with the suction chamber, a delivery pipe connecting the delivery chamber with the valve, and a return pipe connecting the exhaust side of the valve with the housing,` said last-named housing connection being in communication with a port formed in the housing and adapted to register with one of said radial passages, whereby theoil passing. through the return pipe is delivered into 'the axial passage, and certain of the other radial passages being located along the shaft to discharge oil on the clutches.

8. In a reversing mechanism. the `combination of a kdriving shaft, a pair of gears freely rotatable on the shaft, clutches for positively driving either of the gears, a member shiftable to engage either clutch, and hydraulic means for shifting the member comprising a cylinder having a port adjacent each end, a double-acting piston' operating in the cylinderand connected to the member, areciprocable valve adapted to mask the ports when in neutral position and shiftable to open the ports to the incoming fluid and exhaust, respectively, a ilrst link pivotally mounted on the rod of the piston, a second link pivotally connected at its ends to the valve and first link, respectively, vmeans for manuallyl actuating the ilrst link to thereby manually actuate the valve in. either direction independently of the piston, the valve being responsive to movements of the piston when the latter is subjected to pressure, a pump driven by the shaft, and a pipe connecting the pump and valve for deliver- -ing uid under pressurev thereto. WILLIAM J. PEARMAIN.

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