US1292014A

US1292014A - Valve mechanism for hydraulic presses.

Info

Publication number: US1292014A
Application number: US24491018A
Authority: US
Inventors: Eugene Munger
Original assignee: Continental Gin Co
Current assignee: Continental Gin Co
Priority date: 1918-07-15
Filing date: 1918-07-15
Publication date: 1919-01-21
Anticipated expiration: 1936-01-21

Description

E. MUNGER. VALVE MECHANISM FOR HYDRAULIC PRESSES.

APPLICATION FILEDJULY 15.1918.

Patented J an. 21, 1919.

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APPLICATION FILED JULY 15.19l8.

Patented Jan. 21,1919.

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E. MUNGER. VALVE MECHANISM FOR HYDRAULIC PRESSES.

APPLICATION FILED lULY 15.1918.

Patented Jan. 21, 1919.

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APPLICATI'ON FILED JULY 15. IBIB.

Patented Jan. 21,1919.

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- EUGENE HUNGER, or BIRMINGHAM, ALABAMA, ASSIGNOR 'IO CONTINENTAL em COMPANY, OF BIRMINGHAM,

ALABAMA, A CORPORATION OF VALVE MECHANISM FOR HYDRAULIOIPRESSES.

' To all avhomit may. concern:

Be it known that I, EUGENE MUNGER, a citizen of the United States of America, residing at Birmingham, in the county of Jefferson and' State of Alabama, have invented certain new and useful, Improvements in Valve; Mechanism for Hydraulic Presses, of which the following is a specification.

This invention relates to hydraulic cotton trampers, baling presses and the like, and has for its object to perfect the automatic operation of the tramper platen and to so control the hydraulic valve mechanism that the ap aratus will'operate with ease and reliabillty and without the creation of excessive pressures in the valve mechanism or the causing of severe jolts or jars to the press or piping system My invention contemplates no change in the press itself or in the type of press cylinder or platen that may be employed but is addressed more particularly to the hydraulic valve mechanism and the means employed for its automatic control. To obtain the desired functioning of the hydraulic valve mechanism it is desirable that the distribution valve should be designed to avoid the trapping of the h draulic' pressure and the creation therein '0 abnormal fluid pressures. Such a distributing valve mechanism while disclosed in this application forms ject matter of a separate application Serial No. 210,951, filed January 8th, 1918.

The valve mechanism described'in my said application comprises a four-way distributing valve under control of which the hydraulic pressure is delivered to and exhausted from the press cylinder and also a by-pass valve automatically controlled by the tramperand having for by-passing of the hydraulic fluid back to the of its stroke to pump when the press platen reaches the end prevent the building up of high pressures in the cylinder and piping system.

One object of my present invention is to Specification of Letters latent.

improve the mechanism the subits obj ect the Patented Jan. 21, 1919.

Application filed July 15, 1918. Serial No. 244,910.

for effecting the automatic operation of this by-pass valve to the end that it will function at the end of both the up and down strokes of the platen plunger and that it will be opened gradually on the down stroke of the plunger and automatically released so as to permit it to close and develop a pressure in the cylinder sufficient to raise the platen so that the latters return stroke may be automatically accomplished. It will be obvious that if all functions of this by-pass valve are automatic and controlled by the direct movement of the platen itself, the by-pass valve when opened by the descent of the platen would remain open unless closed by hand, and while open would prevent the delivery of sufficient pressure to lift the platen plunger.

A further object of my invention is to give the distributing valve a slow movement as it reverses the pressure at the bottom of the platen plunger stroke, as I have found that a rapid throw of the distributing valve, when controlling the high pressures in the press cylinders, 1s productive of severe jolting and jarring of the Whole press and its distribution piping system.

A further object of my invention is to simplify the mechanism for controlling the reversal of the distributing valve responsive to the movements of the platen of the press box and to this end I contemplate the employment of lost-motion connections in the operating mechanism which imparts the slow movement to throw the distributing valve in one direction and .a spring and latch which will operate responsive to the filling of the press box to reverse the distributing valve and restore it to the direct control of its slow moving operating mechanism which will accomplish its return stroke when the platen reaches the end of its 'down stroke.

My invention also comprises the various detalls of construction and arrangements of parts whichare hereinafter pointed out in the accompan drawings which. form a part of this spec cation, and in which 1 Figure l is a perspective view partly broken away of the hydraulic tramper press for baling cotton.

Fig. 2 is a plan view of Fig. 1.

Fig. 3 is a diagrammatic view illustrating the several parts of the valve operating mechanism and fluid pressure circulating system in outline.

Fig. 4: is a detail perspective view of the valve operating mechanism with the gear case cover removed. V

Fig. 5 is a front elevation of the gear case with the cover removed and the gear in neutral position.

Fig. 6 is a sectional view taken on the line 6-6 of Fig. 5. 1

' Fig. 7 is a detail view in side elevation of the operating mechanism for the b -pass valvec when' the platen is in its lowere position, the by-pass valve being shown in vertical section. 1 a

Fig. 8 is a partial sectional view taken on the line 88 of Fig. 7.

Similar reference numerals refer to similar parts throughout the drawings.

I have illustrated my invention in connection with a hydraulic tramper press mechanism comprising any standard type of press box 1 having above it an outwardly swinging apron 2 suspended by hanger bars 3 from hinge hooks 4 mounted on an I-beamfi or like member forming'part of the overhead frame work. This apron is adapted to be pressed outwardly by the cotton when the press box is filled in the manner well understood in this art by any suitable mechanism (not shown), and thecotton is adapted to be compressed in the press box by a vertically reciprocable platen 6 which is suitably connected to a piston rod 7 operated by a piston which reciprocates in a vertical cylinder 8 suitably mounted on the I-beams 5 and having afluid pressure supply pipe 9 leading from its top to a distributing valve casing 10 and a like pipe 11 leading from its bottom to said valve casing. Fluid pressure is supplied tothe valve casing 10 from any suitable pump 12 flowing therefrom through pipe 13 past check valve 14: to a pipe 15 entering the bottom of the distributing valve mechanism and returning normally through the exhaust pipe 16 to the tank 16 A lever 17 is pivotally mounted in a hearing bracket 18. and is so hung that its upper end is in position to come in contact with a trigger 19 and its lower end to come in contact with the apron 2, when the latter has been pushed nut by the pressure of cotton fed to the press box. When this occurs, the trigger which is mounted on the pivot 20' (Fig. 2) will be lifted from in front of the collar 21 which is mounted on the outer end aaeac a of a valve stem 22 which serves to operate the distributing valve in the casing 10. A detailed description of this valve and its casing is omitted as the same forms the subjectmatter of a pending application aforesaid, it being suflicient to say that any four-way valve structure may be used which will deliver fluid pressure from pipe 13 to the has a vertical flange 30'surrounding its side 7 edge toward the valve and also its outer edge. ihe outer end of this flange is outturned to receive the pivot bolt 20 on which the trigger 19 is fulcrumed. A suitable opening is provided in this flange to receive and guide the valve stem 22, this opening being too small to permit the passage of the collar 21. When the machine is set up to start with the valve mechanism in position shown in Figs. 2 and 3, the pressure is in pipe 11 and the spring 26 is compressed and is held under compression by the trigger 19 engaging the collar 21. As soon as the pressure of the cotton moves the. apron 1 sufliciently to cause the lever 17 torock the trigger 19 and release the collar 21, the spring will force the valve stem to the right to quickly "reverse the valveand direct the pressure into pipe 9 while opening'pipe 11 to the exhaust. At the sametime the lever 24 will be moved about its pivot 2%, causing its free end to shift from the right to the left hand end (Fig. 2) of a slot 31 in a bar 32. A safety lever 33, pivoted for vertical movement in bearings 34 on the plate 25, is normally held out of position to engage the block 23 by a tension stirrup 35 which is locked to the press in the manner well understood in this art. When this stirrup is taken ofi the press, which is necessary to turn the press box, the lever 33 is balanced so that its weighted head will fall between the block 23 and the valve casing 10, thus preventing the valve stem 22 being moved by accident until the press box in proper position and the stirrup is again attached thereto. The gear case 37 is rigidly connected to the bar 32 and Within the gear case is a pinion 38 mounted on a shaft 39 having on its outer end without the gear case a beveled gear i0 meshing with a beveled gear ill on a counter-shaft42 which has fast thereon a sprocket gear 43'which is continul to the axis which lie substantially at ously driven from any suitable source of power by a chain 44. The shaft 42 is mounted on bearing brackets 45 bolted to a plate 46 which in turn is bolted to the adjacent I-beam 5. Bearings 47 for the shaft 39 are also bolted to the plate 46. A casting 48 is rigidly secured to the gear case and projectsbeyond the same opposite to and in llne with the bar 32 and at its free end this casting 48 is provided with an elongated head having therein the vertically elongated slot 49 in which an arm 50 on the cam 51 is slidably engaged, the arm carrying preferably a bearing pin 52 which travels in the slot 49. The cam 51 is mounted in suitable overhung bearings 53 on the plate 46 and is provided with a slot 54, the straight end portions of right angles to each other and are joined by a curved neck struck on an arc concentric with the cams axis.

Referring to Figs. 4, the upper end of the slot 54 is disposed substantially closer of the cam than is the lower end of the slot-and my object in' thus'arranging the slot is to roduce thereb a vertical adjustment for tli which has a bearing pin 56 working in This lever 55, as will be seen more fully in Fig. 7, is a floating lever since its onlyfulcrum is formed by a pin 57 at the top of the link 58, which at its lower end 18 pivotally mounted on the stem 59 of a bythat the press t pass valve 60. The other end of the lever is bent horizontally at 61 to project into the path of a lug 62 carried by a trip block 63 which is secured by set screws 64 on a rod 65 that isvertically disposed and mounted to reciprocate with the press platen 6. The trip block is so disposed relatively to the floatin lever55 that it will engage and deis near end of the latter only at the completion of the down stroke ofthe press platen. This operation is shown taking place-in Fig. 7 and it will there be observed cam 51 operating as shown in full on the far end of thelever 55 is in position to hold that end of the lever in a lowered position, and it thus forms a fulcrum about which they lever as a whole swings when engaged and depressed by the lines, Fig. 7,

- trip block lug 62. This compression of the lever 55 results in forcing the by-pass valve from dotted to full line position, Fig. 7, thereby by-passing the fluid flowing to the valve mechanism through pipe 13 so that it is shunted throu h a pipe 65, by-pass valve asing 66 to a pipe 67 whence it returns to 16. This opening movent of the by-pass valve compresses a ring 68 which will close the valve as soon aseither end of the- 55 is leased.

The trip block 63 carries a bracket 69 areend of the ever 55- rocked from full to 62 and havmg bolted thereto a vertica elongated trip block 70, the ends of which pro ect above and below the bracket 69 and have reversely sloping faces disposed toward a lever 71 pivotally mounted .on a bearing bracket 72 so that it will rock in a vertical plane. The lever carries a crank 73 to which a pull rod 74 is connected at one end while its other end isconnected to a bell crank lever 75 pivoted on a horizontal bearing bracket 76 and carryin at its upper end a roller 77, see Fig. 5, w ich engages the underside of the ear case 37. The trip block is dispose so that its under beveled end will-engage the lever 71 in advance of the lug 62 engaging the floating lever 55 and the block 70 18 adapted to follow down and continue to depress the lever 71 until the platen 6 reaches its extreme lowered 'position. A coil tension spring 78 is interposed in the pull rod 74 so that it will act yieldingly to lift the gear case relatively to the in. This movement of the gear case willbring into mesh with the gear 38 the lower portion of its rack teeth 79 so that the ear 38 will act to move the gear case first in a direction to ull the bar 32 away from the lever 24 until the latter is engaged by the left hand end of the slot 31 (see Fi 3), whereupon the further movement 0 the gear case in the same direction acts to shift the valve rod 22 to the left, compressing spring 26, reversing the valve and moving the shoulder 21 beyond the latch 19 which drops into position behind the same, whereupon the rack teet 79, travels around the curved rack sector and engages the upper rack teeth to return the gear case bar 32 to initial position,'as shown in Fig. 3. As seen in Fi 6, the gear case 37 is left open on its sid e toward the gear 40 which drives the shaft 39. Bolted to the opposite side of the gear case is a box plate 80 to which the

parts

32 and 48 are preferably attached and this plate has along its horizontal center line a guide flange 81 spaced equi-distantly between the upper and lower rack sections,-

ear 38 reaches the end of the lower flange 81 which thereby. serves to hold the rack and gear 38 in positive engagement during the forward and reverse shifts of the gear case. The gear case 37 is thus moved slowly in the manner described to effect a reversal of thedistributing valve and it carries with it the casting 48, and by the coiiperation of theslot 49 in the latter and the arm 50 on the cam 51, the latter is dotted position (Fig. 7).

When this rocking movement starts, the end I 61 of the lever 55 is held depressed by the trip in ,62, and the initial rocking movement 0% the cam .51, by reason of the shape of its slot 54, will give a further depression to the right hand end of the lever 55, causing it to more fully open the by-pass valve 60 so as to insure a low pressure in the pip ing before the reversing operation of the valve takes place. The continued movement of the cam 51 servesto raise the. lever 55 to its dotted line position, Fig'. 7', thus closing the by-pass valve 60 and permitting the pressure 'to build up in the valve casing 10 and to flow through pipe 11 into the lower end of cylinder 8 and raise the platen.

- As the platen rises, the lug 62 releases the When the platen reaches the top of its stroke it will engage a screw 83 in the outer 63 and the .,crew 83 are adjustable so. ..s to

ing lever 55 to the end of a lever 84 pivoted on a horizontal bearing bracket 85 and pivotally connected to the pin 86 which connects the lower end of link 58 to the upper endof the by-pass valve stem 59. A link 87 pivoted on this hearing .85 is also connected to the "pin 57 which pivotally connects the top of the link 58 to the floating lever 55, thus furnishing a rocking support which will'jconfine the floatdesired path of travel throughout its movements. When the platen thus moves the lever 84, it depresses and opens-the Iby-pass valve 60 and by-passes the fluid in the manner described, the platen meanwhile being held in raised position by the action of the check valve 14:. on the res- I sure in the pipes 15 and 11, and the p aten stays in raised position until the apron 2 is tripped responsive to the filling of the press box with cotton, whereupon the latch 19 is tripped, the spring 26 snaps the valve stem 22 to reverse the distributing valve and pressure is admitted to thertop of the cylinder and exhausted from the bottom of the cylinder .so that the downward or pressure stroke of the platen results. At the completion. of this stroke the agencies described will first partially and then completely by-pass the fluidso as to prevent abnormally high'pressures beingcreated in the distribution system while the slowly acting-gear case 37 moves to reverse the dis: tributing valve, whereupon the pressure is diverted to the lower end of the cylinder and exhausted from the upper end and the platen automatically rises. The trip block matically acacia obtain the tions. V

The gear case 37 is typical of anyslow moving reversing mechanism which can be automatically started and stopped under control of the platen, and the slotted bar 32 is typical of any lost-motion connection between the gear case and the valve setting lever 2i which will provide ample time for opening the by-pass valve prior to reversing the distributing valve so that this will not occur in the presence of high pressure and also so that the reversing movement of the valve at the completion of the pressure stroks will be efi'ected slowly as contrasted with the'rapid reversal permitted by the action of the released spring 26 24; the completion of the up stroke of the platen.

Having thus described my invention, what 1 claim as new and desire to Secure by Letters Patent, is: V

1. In a hydraulic tram-per press, a cylinder and its piston, a platen operated by the piston, a fluid pressure distributing system for the cylinder comprising a distributing valve and a by-pass valve to short circuit said distributing valve, and mechanisms automatically responsive to the completion of the platens power stroke for shifting the distributing valve and temporarily opening the by-pass valve.

demred g for the trip Tue- 2. In a hydraulic press, a reciprocable platen, a power cylinder having its piston .operably connected to said platen, a distrilwution system for the fluid pressure comprising distributing valve for the cylinder and a by-pass valve arranged to short circuit the distributing valve and cylinder, and I laten controlled automatic 'mechanisms e ective at the completion of the platens power stroke to reverse the distributing valve and open the by-pass valve during said revel-sai 3 In a hydraulic ress, a platen, a power cylinder having a. piston operatively con- .nected to said platen, a distribution system for the fluid pressure comprising a distributing valve for-the cylinder and a by-pass valve arranged to short circuit the distributing valve, and platen controlled automatic mechanisms effective at both ends of the platensz stroke to open said icy-pass valve and reverse the distributing valve, and

means responsive to the filling oi the press to restrainthe reversal of the distributing valve at'the completion of the platens up stroke.

4. In a hydraulictraanper prem, a cylinder and its piston, a platen operated by the l piston, a fluid pressure distributing system for the cylinder comprising a distributing, valve, a by-pass valveto short. circuit said distributing valve, and mechanisms auto responsive to the platen at the completion or its power stroke for operating means responsive to the return the by-pass valve and'shifting the distributing valve to start the platen on its return stroke, said mechanism for shifting the distributing valve comprising means adapted to impart a-slow reversing movement to said valve.

5. In a hydraulic press, a platen, a power cylinder having a piston operatively connected to said platen, a distribution system for the fluid pressure comprising a distributing valve for the cylinder and a by-pass valve arranged to short circuit the distributing valve, platen controlled automatic mechanisms effective at both ends of the platens stroke t reverse the distributing valve, and means responsive to predetermined conditions to restrain the reversal of the distributing valve at the completion of the platens return stroke, the automatic mechanism which reverses the distributing valve at the completion of the platens power strok comprising a driving element and an intermittently operable driven means adapted to lmpart a slow reversing movement to said distributing valve and a; platen operated trip mechanism controlling the of said driven means.

6. In combination with a hydraulic press having a cylinder and a platen operable thereby, a pressure fluid distributing system comprising a distributing valve for the cylinder, and operating mechanism for said valve =compris1ng a constantly rotatlng driven element, a reciprocable element driven thereby, means automatically operable at the completion of the platens power stroke to connect said driving and driven elements, means to automatically disconnect said driving and driven elements at the completion of the reciprocation of the driven element, a lost-motion operating connection between the driven element and distributing valve, and automatic valve means in said fluid distributing system to short circuit said distributing valve during its oper ation by said driven elemen 7. In a hydraulic tramper press, a cylinder and'its piston, a platen operated by the piston, a fluid pressure circulating system for the cylinder comprising a distributing valve, a by-pass valve toshort circuit said distributing valve, mechanisms automatically controlled by and responsive to the platen at the completion of its power stroke for reversing the distributing valve and opening the by-pass valve during such reversal, said mechanism for operating the distributing valve comprising means adapted to impart a slow reversing movement to the distributing valve, latch controlled spring means which are set by said reversing movement of the distributing valve, and stroke of the press the platen and the recharging of intermittent operation to free said spring means to impart a quick reversing movement to said distributing valve.

8. In combination with a hydraulic tramper press comprising a cylinder and its piston, a platen operable by said piston, a fluid pressure distribution system comprising a distributing valve, and automatic mechanism controlled by the movement of 'the platen at the completion of its power stroke for reversing said distributing valve, said mechanism comprising a transmission means adapted to impart a slow gradual movement to said distributing valve to reverse it and start the platen on its return stroke.

9. In a hydraulic tramper press, a press cylinder, its piston and a press platen operable thereby, a fluid pressure distributing system for the cylinder comprising a distributing valve, a mechanism for automatically reversing said valve at the completion of the platens power stroke comprising a constantly rotating gear, a gear case comprising a segmental gear normally out of mesh with said rotating gear, means controlled by the descending platen to bring said gears into mesh, and means to hold the gears in mesh until the gear case has completed its cycle of movement, a lever for shifting the distributing valve, means mova'ble with the gear case which engage and move said lever in one direction only to reverse'said valve with a slow movement,

a spring. opposing and which is compressed by said reversing v-alve movement, a latch holding said compressed spring in restraint, and means responsive to the recharging of the press 'to trip said latch and release said spring to operate the reversing valve, as and for the purposes described.

10. In a hydraulic tramper press com prising a press cylinder, a piston and a platen, a fluid pressure distributing system which includes a distributing valve for the cylinder, an automatic valve operating mechanism the valve, a of the valve WhlCll reverses it at the completion of the platens power stroke, a bar having a slot in which the free end of said lever works, a segmental gear to ,reciprocate said bar, a driving gear adapted to reciprocate the segmental gear, mechanism controllable by, the descending platen to bring said gears into mesh, means to hold the gears in mesh until the segmental gear completes its cycle of movement, said lever being operable in one direction by said slotted bar to reverse said valve and compress said spring, the valve in said reversed position with said spring compressed, said slot bein adapted to permit the free return to initia comprising a lever coupled 'to' spring opposing that movement latch means to holda position of said lever, and mechanism responsive to the recharging of the press for relatch mechanism to permit said spring to shift said reversing valve, .stantially as described.

leasing said sub- 11. In a hydraulic tramper press, a press cylinder and itspiston, a fluid pressure distribution system comprising a distributing valve and a by-press valve toshort circuit the fluid pressure relatively to said distributing valve, a press platen operable by the piston, automatic platen controlled mechanisms for reversing said distributing valve at each end of the platens stroke, mechanism to restrain the reversal of the distributing valve at the completion of the platens return stroke until the press has been recharged, automatic means to open completion of the platens power stroke,

mechamsm requiring the joint action of said valve reversing mechanism and the platen to hold the by-pass valve open, and means to cause the by-pass valve to close at the completion of said reversal of the distributin valve.

13. 'l e combination with a hydraulic tramper press, of a fluid pressure distribution system for the press cylinder comprising a distributing valve and a by-pass valve to short circuit the distributing valve, a floating lever for operating vthe by-pass valve, an element movable with the platen and adapted to engage said lever at the cornpletion of the platens power stroke, automatic mechanism controlled by. the platen for reversing the distributing valve at the completion of the platens power stroke, and an element movable with said mechanism and forming a shifting fulcrum which, in

conjunction with said platen element, will hold the by-pass valve open only during said reversal of the distributing valve.

-14. In a hydraulic tramper press, the com- 'nat1on with a press cylinder and platen v operable thereby, of a fluid pressure distri-- on system for the cylinder comprising stribnting valve and a by-pass valve ajpted to short circuit the distributing valve, automatic mechanism controlled by thedescent of the press platen for rovers aaeaora said distributing valve at the completion of the power stroke of the press, a crowable by said mechanism, a floating lever operable jointly by said cam and said descending platen to open said by-pass valve, said cam assuming position at the completion of the reversing valve stroke which permits said by-pass valve to close, substantially as described. a i

15. In a hydraulic tramper press, the combination with a press cylinder and platen operable thereby, of a fluid pressure distribution system for thecylinder comprising a distributing valve and a self closin by-pass valve adapted to short circuit the istributing valve, automatic mechanism controlled by the descent of the press platen for reversing said distributing valve at the completion of the power stroke of the press, a reciprocable cam movable by said mechanism, a heating lever operable jointly by said cam and said descending platen to open said Toy-pass valve, said cam assuming position at the completion of the reversing valve stro which permits the by-pass valve to close,

substantially as described.

16. In combination, ahyulic press cylinder, a platen operable thereby and a fluid pressure distribution system for the cylinder comprising a distributing valve and a by-pass valve adapted to short circuit the distributing valve, of automatic mechanism controlled by the platen and adapted to reverse said distributing valve at the completion of the platens power stroke, a double cam operable by said mechan, a floats ing lever having one end operable by the cam and its other end interposed in the path of an element on the descending platen and operable thereby about the cam as a l v to open the by-pass valve, said cam being adapted upon resuming its initial position to permit the by-pass valve to close, and

means to close the by-pass valve when re" leased from the joint action of the platen element and cam;

17. In combination, a hydraulic press cylinder, a platen operable thereby and a fluid cram r pressure distribution system for the cylinder 7 comprising a distributing valve and a bypass valve adapted to short circuit the reversing valve, of automatic mechanism controlled by the platen and adapted to reverse said distributing valve at the completion out the platens power'stroke, a cam operable by a said mechanism, and a floating lever he one end. operably engaged by the cam an its other end interposed in the path of an element on the descending platen and op erable thereby about the cam as a fulcr to open the by-pass valve, said cam bein shaped as it moves in each cycle with said mechanism to at first further open the byp ss valve and then to cl it,

I .its free end adapted 18. The 4 combination with. a hydraulic press organization comprising a cylinder,

piston, platen and a fluid pressure distribu tion system for the cylinderincludin a distributing valve 'and. a self closing fiy-pass valve adapted to short circuit the distributing valve, a. check valve between the by-pass and distributing valve, a stem forthe by pass valve, a lever having a fixed pivot conthe stem and havin to be engaged an meved'by the platen at the completion of its return 'stroke, a second le'ver connected to nected at one end to said stem and having one end adapted to be engaged and moved by the platen at the i5 completion of its power stroke, a, shifting fulcrum for said second lever, and mechanism for reversin said distributing valve at the completion 0 the latens 'power stroke and for shifting said f illcrum sufiiciently to pegmit said by-pass valve tdclose at the completion of said reversing valve movement.

In testimony whereof I a my signature. EUGENE MUN GER. Witne'ss;

NoMm WELSH.