US1552768A - Hydraulic press apparatus - Google Patents

Description

E. M. aMilTH HYDRAULIC PRESS APPARATUS 1922 8 Sheets-Sheet 1 FIG./.

Filed Oct. 31,

Sept. 8 1925. 1,552,768

E. M. SMITH HYDRAULIC PRESS APPARATUS Filed Oct 31. 1922 8 Sheets-Sheet 2 Sept. 8, 1925. 1,552,768

E. M. SMITH HYDRAULIC PRESS APPARATUS Filed Oct. 31. 1922 8 Sheets-Sheet a a l nae 2701' 1 1. J g Hak m? M JZImrnq J:

E. M. SMITH HYDRAULI C PRES S APPARATUS Filed Oct. 31, 1922 8 Sheets-Shea;

MD 0 a III]! II llll lll SGML 11925. 552,768

E. M. SMITH HYDRAULIC PRESS APPARATUS Filed Oct. 31, 192 a sheets-sheet s Sept. 8, 1925.

E. M. SMITH HYDRAULIC PRESS APPARATUS Filed Oct. 51,

1922 8 Sheets-Sheet 6 F/Gii.

L L2 L3 E. M. SMETH Sept. 8, 1925.

HYDRAULIC PRESS APPARATUS 8 Sheets-Sheet 7 Filed Oct. 31, 1922 Ewen$r E MSml'flb imiib wwiimi E. M. SMETH HYDRAULIC PRESS APPARATUS 1922 8 Sheets-Sheet 8 Eiled Oct. 33,,

I M/UUT Patented Sept. 8, 1925.

UNITED STATES PATENT OFFICE.

ERIC 1. SMITH, OF SAL'I'FORD, ENGLAND.

HYDRAULIC PRESS APPARATUS.

To all whom it may concern:

Be it known that 1, ERIC MONTAGUE SMITH, engineer, a subject of the King of Great Britain, residing at Keynsham Manor,

Saltford, in the county of Somerset, England, have invented certain new and useful Improvements in Hydraulic Press Apparatus, of which the following is a specification. This invention refers to improvements in or relating to hydraulic press apparatus and has for its primary object the provision of an automatlcally acting self contained h draulic press, that is to say an apparatus t e operative parts of which are all contained within or carried by what is substantially a single casing and the parts of which will all act automatically.

Thus in my improved apparatus the power stroke of the ram is carried to a predetermined limit which is variable at will and there terminated automatically either by mechanical means controlled by the length of stroke or by the attainment of a redetermined pressure. After the end of t e power stroke the ram is automatically retracted in readiness for the next power stroke, and so on during the operation of the press.

A further ob ect of the invention is the provision of a variable stroke pump for transferring the pressure liquid to the ram cylinder, the length of the stroke of the pump being automatically varied in accordance with the resistance encountered.-

The improved hydraulic press apparatus according to the present invention comprises broadly a ram operating in a cylinder, a reservoir for containing the pressure-1i uid formed integral with or'directly attache to the ram cylinder, pumping means located 40 within said reservoir to force the pressureliquid therefrom into the ram cylinder, valve controlled passages inter-connecting the reservoir the cylinder and the pump, automatically acting means capable of variable setting to release the pressure in the ram cylinder and thereby terminate the power stroke of the ram and automatic means for retracting said ram.

Apparatus constructed in accordance with W my present invention are illustrated in the accompanying drawings in which Fig. 1 is a vertical sectional view of one construction of my hydraulic apparatus in which the main ram (after the power stroke) is returned by a jack ram located on the 011 reservoir side of the partition between the main ram chamber and the said oil reservoir; while the mechanism for operating the valves, at each end of the travel of the mainram, is shown mounted on the outside of the oil reservoir.

Fig. 2 is a vertical section of a slightly different construction of my hydraulic apparatus, which incorporates a jack ram for the power return stroke, together with a relatively small auxiliary ram (to allow rapid travel of the main ram during the idle part of the power stroke) both of which are shown contained within the main ram itself. Within the oil reservoir are shown twin-opposed pumps and valve-block unit, the automatic reversing mechanism together with its adjustable controlling rod, and the auto matic variable pump-stroke mechanism hereinafter described.

Fig. 2 is a diagram showing the valves and their actions in said apparatus Fig. 2.

Fig. 3 is a vertical sectional view of the up r art of another arrangement of my hy rau ic apparatus wherein all the parts are automatically caused to function; and this arrangement may conveniently be termed the full automatic apparatus, in so far that it is arranged to reverse automaticall either at a redetermined length of stro e or at a pre etermined total pressure v of the ram.

, crate within the main ram itself.

Fig. 7 is a separate view of the variable gear (hereinbefore referred to for operating the oil pump) for automatically varying the length or extent of the pump stroke without re uiring any variation either (a) of the speed of the shaft or (b) of the power (derive from any suitable source) applied to slaid shaft by which said pump is operate Fig. 8 is an end view (in elevation) on line 11-11 Fig. 7 looking in the direction of the arrow 2.

Fig. 9 is a similar view toFig. 6, but with the eccentric sleeve part of the said gear rotated into a different position relatively to the other parts of said gear.

F Referring now more particularly to is the main ram chamber. Bthe main ram, C the oil reservoir. D is the j ack ram.

In this apparatus (1 3% 1) the main casing E has the partition 1 formed integral therewith (by casting or otherwise) and also the jack ram cylinder E The part of the main casing E enclosing the oil reservoir C in this arrangement is formed integral with the part forming the main ram cylinder A.

E is removable cover fixed to the top, and E4 removable cover fixed to the bottom, of the said main casing E.

E E are downwardly extending. pins rigidl fixed to the underside of the partition E and fitting in corresponding holes in the ram B to prevent any axial rotation of the latter relative to the casing E.

B is stout rod attached to the top of the main ram Bi and adapted toslide through the gland E in the partition E and above the latter the jack ram D is attached to said rod 13 This rod B also has rigidly afiixed thereto the laterally extending arm B and the vertical rod B or if desired the vertical rod 13 may slidably pass through-the partition E and be rigidly fixed direct to the main ram B.

D is an oil outlet passage in the jack ram D controlled by the valve D which acts as a safety valve to prevent excessive retraction of the main ram, by coming into contact with the abutment D fixed in the cover E and being forced open to thereby release the pressure in the jack ram cylinder D F is spring controlled slotted quadrant (i. e. slotted at F) of automatically acting valve trip gearwhich quadrant is pivote at F on the fixed mount E on the top cover E and is provided with the downwardly extending rigid arm F which I will term the striker arm F.

F is a stirrup (provided with a roller) adapted to travel freely along the curved slot F 1 F is a stout spring attached at one end to said stirrup F and at its other end fixedly attached to a lug or anchorage F on the cover E; this point of anchorage F being in the vertical plane of the axis F about which the striker arm F oscillates.

B and B are two short rigid arms or devices adjustably mounted on the rod or post B and extending laterally therefrom so as to be adapted to alternately act on the crank in F fixed on the shaft F 2 of the quadrant to thereby partially rotate the latter around its axis F whereby the strong sprin F is put under tension until the stirrup has passed the dead centre-and can race down the slot F whereupon the quadrant is tilted over with a jerk or snap and with it the striker arm F and thus the striker arm F s is caused to oscillate back and forth withthe desired snap action in each direction alternately.

G is slide bar carryin two stout upright arms or posts G and which latter are located in the path of travel of the lower end of the striker arm F This slide bar G is held freely slidable in the guides or bearings G and G and towards its right hand end this slide bar G is provided with the cam surface G to act on (depress) one or other of the two valve rods H and H alternately against the action of springs arranged to return said valves and rods.

H is an oil pump; H are eccentrics on the shaft H (driven from any suitable source of power) to drive the plungers of the oil pumps H H.

H is an independent valve operating rod adapted to be actuated by hand to open communication through a passage not appearing in the sectional View Figure 1 between the main ram chamber A and the oil reservoir C, and thus enable the power stroke of the main ram to be stopped (by hand) if desired at any required point in said stroke.

H is the elongated stem of the valve H controlling the oil passage through the partition E between the main ram chamber A and the oil reservoir C. The valve stem H is automatically operated by the rigid arm B at the limit, of the power stroke of the. main ram B to thus automatically stop the power stroke if the main automaticall -acting mechanism, G, H H etc., F etc., s 011101 from any cause fail to function properly.

Any oil that may escape past the main ram B will be forced, by the underside of the latter, past the non-return valve H and delivered through the conduit H back into the oil reservoir C.

H is a safety valve in the pump circuit.

The 0 eration of this apparatus (Fig. 1) is as fol ows The pump H is actuated and forces oil (through passages not appearing in the sectional view Figure 1) from the oil reservoir G into the main ram chamber A and into the jack ram cylinder D of the jack ram D during the power stroke, at the end of which latter the rod B actuates the valve tri gear F, F, F", F", G, G, G, G, H, and thereupon the jack ram Dv (to which the pump continuously delivers oil under pressure) imparts the return stroke to the main ram B and the latter forces the 011 in the main ram chamber back into the oil reservoir C through the now open communication between the chambers A and C untll, at the end of the return stroke of the mam ram B, the valve trip gear aforesaid is actuated in the reverse direction whereupon the pump H again delivers oil under pressure to the main ram cylinder A; and the cycle is repeated, and so on.

Or if desired the pump H can be arranged to only deliver oil under pressure to the jack ram for the return stroke of the main ram and not during the power stroke of the latter.

Referring now more particularly to Figs. 2 and 2.

The parts of the valve trip gear F, F, G}, G G etc., are arranged inside the 011 reservoir C, and are actuated by the rod B attached to the main ram B and in this arrangement the quadrant F has rigidly fixed thereto the crank arm F 6 the outer end of which latter is acted on alternately by the devices B and B adjustably fixed on the rod B to thereby operate said trip 1ggear.

In this arrangement, the part of the main casing which encloses the oil reservoir chamber C is shown formed separately from the main casing E in which latter is formed the main ram cylinder A for the main ram B; the said two casingsor parts E E being secured to each other in an suitable manner. 01 said main casing E may if deiired be formed integral, for example as in n this apparatus (Fig. 2) the main ram B is itself formed hollow, i. e. so as to form the jack ram cylinder D and the auxiliary ram I) within the main ram B.

To the partition E is rigidly aflixed, coaxial with the main ram' cylinder A, the downwardly extending post or rod I, the cross sectional area of which is less than the interior bore (forming the jack ram cylinder D) of the main ram B through the to of which latter said rod I makes a close sli able fit (e. g. through an suitable gland or packing in the top end 0 said main ram B) while the lower end I of this post or 1nd I is formed like a double acting hydraulic piston; only in this case this head end I is, of

course, stationary and its cylinder (the main ram B) is reciprocated with respect to said head end orpiston P.

In order to ex lain the action of this press I will now describe it with reference to F i 2. I is an oil conduit through rod I leading from the oil ump conduit I to the auxiliary ram cylin or D below the head I I is an oil conduit leading from the pump conduit I to the jack ram 0 linder D above the head I (this chamber 5 is always open to the pump pressure while the press is workloaded valve which prevents oil under pressure from entering mainram cylinder A until the main ram B encounters greater resistance than can be overcome by auxiliary ram D. I is an automatic exhaust nonreturn valve from chamber A to reservoir C. 1 and I are respectively exhaust and in-let valves operated by the automatic valve 0 erating gear F, F F, G, G G etc., ig. 2). I is the valve controlling supply of oil from the pump to the jack ram D. I is a safety valve in the pump circuit which blows when the maximum working pressure is reached.

H is non-return valve; and H conduit through which any oil, which may escape past the exterior of the main ram B, is forced by the latter back into the oil reservoir chamber C. Automatically actin stroke limiting valves (such as H H in ig. 1) may be fitted; and also, if desired, a hand operated mechanism (such as the rod H Fig. 1) for manually stopping the power stroke of the main mm B at any desired point in said stroke.

The method of operation of the apparatus (Figs. 2 and 2) is as follows The ram B is about to commence the power stroke, the pumps to deliver oil to the auxiliary cyllnder D and j ack-ram cylinder D"; hence as main ram B descends it draws oil from reservoir G into main ram cylinder A through valve I. When ram B reaches its work the pressure from the pumps increases and o ens valve I, valve I then automatically c oses and the oil under pressure from the umps is delivered to the main ram 0 linder as well as auxiliary ram D and t e ram B continues to travel at full pressure. When the predetermined stroke has been completed the automatic valve gear, previously mentioned, closes valve I", opens exhaust valve I, and the automatic exhaust valve I opens. The jack ram cylinder D is still open to the full pressure from the pumps, hence ram B is returned to its original position and the oil from cylinders A and D is returned to reservoir C through conduits I I and I Referring now to the apparatus shown in Figs. 3 a) e:-

In this arrangement the oil pump plunger Z (Fig. 4) is operated by one or other of the three eccentrics L or L or L fixed on the driving shaft L, which latter is capable of being moved endwise so as to brin either one or other said eccentrics into posltion to operate said plunger and to be held in said position by ringing one or other of the circular grooves L or L or L' under the pivoted plate or pawl L (Fig. 5) so that the latter can rest msaid groove and thereb shaft {I during rotation.

Z are springs which through the medium of the cross head Z (Fig. 4) fixed to the plunger Z keep the anti-friction roller Z mounted on the outer end of sad Plunger pressed against the eccentric operating the said lunger e. g. against the eccentnc L as in igs. 4 and 5.

The oil under pressure from said pump is delivered into the main ram cylinder A for example through a conduit Z as indicated in dotted lines in Fig. 3; which conduit is in open connection with the conduit Z, see Fig. 3.

This conduit Z leads into the passage M but is normally held closed by the valve M which is forced down on its seating by the pin M which latter is forced down by the projection N on the lever N ivoted at N at one end, whilethe other en of this lever N is held down by the adjustable spring N and the tension on this spring N can be increased or diminished by revolving the nut or collar N on the screwed rod N which latter is attached to said lever N; so that the valve M can thus be set to lift at any predetermined pressure of the oil in the cylinder A and conduits Z Z".

When the predetermined pressure to which the valve M has been set is exceeded and the valve M lifts, thereupon the oil under pressure passes through the passage M and forces outwardly the plunger M the extension of which M forces (to the left) the lever M rigidly fixed on the rocker shaft Msee Figs. 3 and 5.

On this rocker shaft M there is also rigidly fixed the lever or trigger M notched at M (see Fig. 3) and normally kept pressed to the right by the spring M fixed on the back of said tri ger M and bearing against the inside of tie casing E of the oil chamber 0.

O is a lever pivoted at 0 in a fixed moiuit; the end 0 of this lever normally resting upon and being supported by the notch M of the trigger or lever member M; while the other end 0 of said lever (when the end 0 is supported on the notch M forces down, and keeps forced down, the valve 0 upon its seatin so as to close the outlet 0 leading from t e cylinder A into the. oil chamber C.

Through a lateral projection or lug 0 (Fig. 4) on the side of this lever 0 an adjustable screw pin 0 is mounted and adjusted to such position that when the end 0 of the lever O descends (upon withdrawal of the notch M thereupon the pin 0 forces down the. valve M and thereby releases the pressure of the oil in the conprevcnt endwise movement of the 1 duit M and cylinder M thus allowing the spring M to return the plunger M to its 'ori inal position. I

5' (Fig. 4) is upwardly extending n 6. rod fixed to the lever O, with the adjusta le collar 0 thereon.

B (Figs. 4 and 5) is vertical rodrigidly attached at its lower end to the main ram B (see Fig. 6) and towards its upper end this rod is provided with the adjustable collar 0 thereon; the collar 0 on the rod 0 bein in the upward path of travel of the collar The operation is as follows At the end of the return stroke and at the commencement of the power stroke of the main ram B the parts are in the position shown in Fig. 3. As the power stroke of the main ram B proceeds and eventually the predetermined pressure to which the valve M has been set-by t e""colla.r N) is reached, and the valve M is forced open by said pressure, thereupon the plunger M and extension M force the lever M and with it the trigger or lever member M to the left until the end 0 of the lever O is released (by the notch M and descends, and the other end 0 slightly ascends and allows the valve 0 to open and thereby release the oil pressure in the cylinder A; whereupon the return stroke is imparted to the main ram B by the spring B (see Fig,

6) which in this case is located in the hollow part of the main ram B and is'compressed therein against the fixed head B on the fixed rod B carried on the partition E of the casing E.

As the main ram arrives at the end of the return stroke, the rod B forces the collar 0 against the collar 0 on the rod 0 and the latter lifts the end 0 ofthe lever 0 until the notch M of the trigger M is forced by the sprin M under said end 0 of the lever O, and thereby the valve 0 1s again securely locked and held in the closed position, in readiness for the next power stroke which then commences; and so on.

4 Hence it willbe seen that the press can be set so that any desired pressure can be exerted on the main ram and on such predetermined pressure being reached or exceeded, thereupon the pressure is automatically released and the ram automatically re-. turned, and the parts reset automatically, and the next ower stroke commenced automatically an so on.

P (see Figs. 3 and 5) is a cam shaft adapted to be manually operated from the exterior of the casing E for example by a hand lever P as shown in Fig. 5.

P and P (see Figs. 3 and 5) are two cams fixedly mounted on said cam shaft P; the cam P is adapted to act on the lever M to thereby force the trigger M to reweaves lease the end 0 of the lever O (by hand) while the cam P will act on the under side of the lever 0 towards the end 0 thereof to raise the latter (by hand) when required.

If it is desired to operate this press as shown in Figs. 3 to 6 with reference to stroke and not ressurez- First of all ock the valve M by screwin the nut or collar N to its limit. This wil prevent the aforementioned pressurerelease from operating. The press can now be controlled with regard to the ram stroke as follows The main ram B has traversed to the predetermined length of its power stroke, the rod B which is rigidly connected to said ram B has brought the collar 0 down in contact with the lever M which is rigidly fixed to the shaft M, thus releasing end of lever 0 from notch M hence the mam exhaust valve 0 opens as previously described. The oil in cylinder A then exhausts to reservoir C through conduit 0, and the main ram B is returned to its initial position by the spring B (Fig. 6). At th end of this return traverse the collar 0 comes in contact with collar 0 which in turn by means of rod 0 pulls lever 0 upwards until the end 0 engages wlth the notch M in the sprin loaded lever M"; the main exhaust valve 3 is then closed and the press then starts on the next power stroke and so on.

It will thus be seen that the operation of this form of hydraulic apparatus is fullautomatic in very sense.

Referring now to Figs. 7 to 9, which show a special form of variable gear for operating the oil pump in my aforesaid hydraulic apparatus; this variable gear is as follows Q is shaft for operating the pump through the medium of said variable gear; this shaft Q being arranged to be' rotated at a constant speed and at a constant power derived from any suitable source of power or by hand operated means. This shaft Q is supported in the upright post R of the fixed frame It and in the axially adjustable bearing R in the upright part R of said fixed frame or support R; and shaft Q is incapable of endwise movement. The adjustable bearin -R is provided with a re: cess R adapte to receive therein one end of the spring S the other end of which latter bears in an annular recess T in the, end of the stout slidable sleeve or bush T which latter is splined on saidshaft Q so as to be slidable endwise on said shaft. R is a stop ring or stop plate (through which the power shaft Q passes freely) which is arranged and mounted in juxtapositionto the right hand end of the slidable bush T and supported in the upright R of the fixed frame through the medium of the screwed pins R which pass freely through said vertical support It and each aving the screwed nut R thereon (see Fig. 7) so that by correspondingly screwing said nuts R along said screw pins R in one direction or the other thereby the stop plate R can be adjusted toward or away from the slidablesleeve or bush T and thus form a fixed abutment at any desired oint to limit the movegneifi $0 the right 0 the slidable sleeve or By adjusting the bearing R -towards or away from said bush T thereby the spring i S is more or less compressed between sai bearlng R and bush T; and thus offers greater or less initial resistance to the endwise movement of the bush T.

The external periphery of this slidable bush T is eccentric with the bore thereof 1. e. eccentric with the shaft Q upon which latter same can slide axially along the feather Q The said external periphery of the bush T is provided with a. helical groove or female thread T On the exterior of this slidable bush T an eccentric ring U is mounted which ring is provided interiorly with a male thread U adapted to fit in the aforesaid helical groove or female thread T in th bush T.

The ring U is provided with the external flange U so as to hold in position on said ring U the sleeve or strap W which latter has the rod or rigid arm W rigidly attached thereto.

The sleeve or strap W is held in position on sald ring U by the aforesaid annular flange U and by means of the locking r' U screwed on to said ring U. This rigi rod W passes through the cross head or short shaft X (in which it is a sliding fit) the latter having trunnions or ends X journalled in the bearings X formed in the fixed frame R; and this rigid rod W below said bearing is thus caused to oscillate more or less and thereby to operate the pump-for example as indicated in dotted lines in Fig. 2 of the drawings.

The operation of this variable gear is as follows:

Upon the shaft Q being rotated the stout rigid rod W for operating the pump is oscillated for the maximum distance and consequently the maximum stroke is imparted to the pump.

As the pressure of the oil increases, i. e. as the resistance of the pump to its operation increases, thereby resistance to the rotation of the slidable bush T by the shaft Q increases and this resistance tends to cause said slidable bush T to slightly rotate (on the helical groove T and male thread U relatively to the ring U and, as the latter is held against any axial displacement, therefore the bush T will slide (along the shaft Q) towards the fixed abutment-R and further compress the s ring S in so doing, and

at the same time e relative ositions of the eccentrics T and U will chan d, and thus reduce the extent of the 0901 ation of the pump. operating rod W and thereby automatically increase the power; and, as further resistance is oifered b the pump thereby the slidable bush T will be caused to be moved further towards the fixed abutment R, until finally, if the resistance of the pump continues to increase the, two eccentrics T and U will be move into such position relatively to one another that no movement will be imparted thereby to the pump, and the operation of the pump will thereupon cease.

By adjusting the bearing ring R thereby the variable gear can be arranged to stop further pumping as soon as an predetermined pressure of the oil by sai pump has been attained.

This variable gear is shown ap lied in only one of the several alternative orms of apparatus illustrated in the accompanying drawings viz in Fig. 2 as aforesaid; but said variable gear may be applied for operating the pumps in any of the other forms of my apparatus as desired.

Hydraulic apparatus according Present invention has (inter alia) owin advantages 1. lf-contained, and hence portable.

2. No external piping.

3. No external working joint or gland under pressure.

4. Automatic control )of ram stroke in each direction.

5. Ram stroke automatically variable in relation to total ram stroke.

6. Automatic varying pum strokes.

(0:) which allows maximum oad to be predetermined at which ram will work.

(b) which allows ram to work with maximum efiiciency up to maximum load at constant horse power.

(a) which controls the speed of ram travel.

((1) enables -a large press to be worked by very small power from any suitable source; or by hand power if necessary.

7. Automatic valve trip mechanism.

a; Mechanically operated.

b Hydraulically operated.

ither of which two last-named mechanism can be instantly stopped by hand.

8.-Main .ram with integral jack ram for power reversal.

9. Main ram with an auxiliary ram and an inverted jack ram within itself for high speed traverse at low total pressure, and

power reversal.

10. Since whole unit is self-contained only a small quantit of liquid is used. which circulates continual y within the apparatus and hence this liquid can be of high qual- 1t y to preserve leathers and prevent corrosion and can be filtered so that no forei r matter can injure the valves or other wor iniparts.

self-contained hydraulic apparatus or hydraulic unit accor ing to th1s invention may be employed for various purposes such for example as the following Punching, shearing and riveting machines; bar croppin (for ferro-concrete work, etc.) structura section cropping; hot pressmg (instead of drop forging); piercmg and prewing purpose; nding and strai htemng machines; serrating corrugated iron sheets; notching structural sectlons; hydraulic loading on rolling mills, etc; briquette making presses; brick makmg and pottery moulding machines; foundry moulding; die castin ;independent control of nava guns, etc.; ollow-ware pressing in multiple; silver trade pressing; em-.

bossing; medalstriking, piercing, etc; fibre and paper compreming machines; baling (jute, tobacco, hay, cotton, etc; pressing machines); application to tensile and'compression testing machines; quartz and ore crushing; extract drug and cereal compressin nib making in multiple; hydraulic ar or press; book binding, etc. etc; or for any other machines or purposes to which same may be applicable.

What I claim is 1. A self contained hydraulic press apparatus comprising a ram operating in a cylinder, a reservoir for containing the pressure-liquid attached to the ram cylinder, pumping means located within the reservoir to force the pressure-liquid therefrom into the ram cylinder, valve controlled passages inter-connecting the reservoir the cylinder and the pumping means, automatically acting means capable of variable setting to release the pressure in the cylinder and thereby terminate the power stroke of the ram, and automatic means for retracting said ram.

2. A self contained hydraulic press apparatus comprising a ram operating in a cylinder, a pressure-liquid reservoir directly attached to the ram cylinder, a pump wlthin the reservoir! to transfer the pressure-liquid therefrom to the cylinder to actuate the ram,

.valve controlled passages inter-connecting the reservoir the cylinder and the pump, a rod attached to the ram and extending mto the reservoir and therein provided with an abutment adjustable thereon to engage, at any predetermined oint in the travel of said rod, a valve re easing device to open communication between the cylinder and the reservoir for return of the pressure-liquid, and automatic means for retracting the ram,

3. A self contained hydraulic press apparatus comprising a ram operating in a cylinder, a reservoir for the pressure-liquid directly attached to the cylinder, a pump within said reservoir to force the pressure-liquid to the ram cylinder, valve controlled passages inter-connecting the reservoir the cyl-' inder and the pump, a rod attached to the ram and extending through the division wall into the reservoir and carrying therein variable means to actuate, at any predetermined point in the power stroke of the ram a valve to open communicationbetween the reservoir and the cylinder to stop the power stroke of the ram and permit return of the pressure-liquid, and variable means for releasing the pressure-liquid in the cylinder upon the attainment of any predetermined pressure therein.

4. A self contained hydraulic press apparatus comprising a ram operating in a cylinder, a reservoir for the pressure-liquid directly attached to the cylinder, a pump within said reservoir to force the pressure-liquid to the ram cylinder, valve controlled passages inter-connecting the reservoir the cylinder and the pump, a rod attached to the ram and extending through the division wall into the reservoir and carrying therein variable means to actuate, at any predetermined point in the power stroke of the ram, a valve to open communication between the reservoir and the cylinder to stop the power stroke of the ram and permit return of the pressure-liquid, spring loaded system of levers and trip gear arranged within the reservoir and operating upon the attainment of a predetermined pressure in the ram cylinder to release the pressure-liquid in the ram cylinder thereby terminating the power stroke of the ram and permitting the return of the pressure-liquid to the reservoir.

5. A self contained hydraulic press apparatus comprising a ram operating in a cylinder, a reservoir for the pressure-liquid directly attached to the cylinder, a pump within said reservoir to force the pressure-liquid to the ram cylinder, valve controlled passages interconnecting the reservoir the cyland a variable tension inder and the pump, a rod attached to the ram and extending through the division wall into the reservoir and carrying therein variable means to actuate, at any predetermined point in the power stroke of the ram, a valve to open communication between the reservoir and the cylinder to stop the power stroke of the ram and permit return of the pressure-liquid and a variable tension spring loaded system of levers and trip gear operating upon the attainment of a predetermined pressure in the ram cylinder to release the pressure-liquid in the ram cylinder thereby terminating the power stroke of the ram and permitting the return of the pressure-liquid to the reservoir, and means for automatically retracting the ram after each power stroke.

6. A self contained hydraulic press apparatus comprising a ram operating in a cylinder, a reservoir for the pressure liquid directly attached to the cylinder, a pump located within the reservoir to force the ressure-liquid to the ram cylinder, variable stroke means to actuate the pump, the stroke automatically varying inversely as the counterpressure, valve controlled passages inter-connecting the reservoir the cylinder and the pump, a rod attached to the ram and extending through the division wall into the reservoir and carrying therein variable means to actuate, at any predetermined point in the power stroke of the ram, a valve to open communication between the reservoir and the cylinder to stop the power stroke of the ram and permit return of the pressure-liquid'and a variable tension spring loaded system of levers and trip gear operating upon the attainment of a predetermined pressure in the ram cylinder to release the pressure-liquid in the ram cylinder thereby terminating the power stroke of the ram and permitting the return of the pressure liquid to the reservoir, means for automatically retracting the ram after each power stroke and for commencing the next power stroke.

E. M. SMITH.

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