US3523443A

US3523443A - Hydraulic press

Info

Publication number: US3523443A
Application number: US664431A
Authority: US
Inventors: Herbert Allen
Original assignee: Cameron Iron Works Inc
Current assignee: Cooper Industries LLC
Priority date: 1967-08-30
Filing date: 1967-08-30
Publication date: 1970-08-11
Anticipated expiration: 1987-08-11
Also published as: GB1207687A; FR1544472A; DE1627808A1

Description

Aug. 11, 1970 ALLEN 3,523,443

HYDRAULI C PRES 5 Filed Aug. 30. 196'? 5 Sheets-Sheet 1 Herberz /l//e/2 INVENTOR.

. 7 W M Z H. ALLEN HYDRAULIC PRESS 5 Sheets-Sheet 2 Filed Aug. 30, 1967 x N n Herbert I //en I N VEN TOR.

Aug. 11, 1970 ALLEN 3,523,443

HYDRAULIC PRESS Filed Aug. 30. 1967 5 Sheets-Sheet 5 Herbert A /efl INVENTOR.

ATTORNEYS Aug. 11, 1970 ALL-EN 3,523,443

HYDRAULIC PRESS Filed Au fso, 1967 5 Sheets-Sheet 4 INVENTOR.

A g 11, 1970 H. ALLEN 3,523,443

Filed Aug. 30. 1967 5 Sheets-Sheet 5 United States Patent 3,523,443 HYDRAULIC PRESS Herbert Allen, Houston, Tex., assignor to Cameron Iron Works, Inc., Houston, Tex., a corporation of Texas Filed Aug. 30, 1967, Ser. No. 664,431

Int. Cl. B21j 9/12 US. Cl. 72-453 29 Claims ABSTRACT OF THE DISCLOSURE A hydraulic press comprising a frame having upright sides, a first platen fixed to one end of the frame, and a second platen supported between the ends of the frame for movement toward and away from the first platen. Cylinders are arranged between the platens in substantially parallel, longitudinally and laterally extending rows, with alternate cylinders in each row forming a first set extending from the inner face of one platen and the remaining cylinders forming a second set extending from the inner face of the other platen. The axes of the cylinders are parallel and the axis of each cylinder is laterally offset from the axis of each adjacent cylinder in the same row by a distance not substantially greater than the the sum of their inner radii. Each ram of a first set of rams is sealably reciprocal in a cylinder of the first set and in force-transmitting relation with adjacent cylinders of the second set, and each ram of a second set of rams is sealably reciprocal a cylinder of the second set and in force-transmitting relation with adjacent cylinders of the first set. A means is also provided for introducing hydraulic fiuid into each cylinder so as to urge the rams and thus the platens in opposite directions.

This invention relates generally to hydraulic presses. More particularly, it relates to improvements in hydraulic presses of the type having a plurality of rams for moving one of the platens thereof relative to another platen.

In conventional hydraulic presses of this type, cylinders for the rams are arranged between the inner faces of fixed and movable platens, so that the die or other work-forming part on the movable platen can be pressed against the work supported on another platen. In the interest of maintaining the length and width of the platens as small as possible, and thus reducing to a minimum the size and cost of the press, each cylinder is normally disposed with its outer walls as close as possible to the outer walls of adjacent cylinders. Nevertheless, even with this arrangement, it has normally been necessary to space the axes of adjacent cylinders from one another a distance at least as great as the sum of their outer radii.

Thus, according to conventional practices, large capacity presses require more, or larger, ram cylinders and larger platens, even though the increased working area on the platens is not needed. This greatly increases the cost of the press since its frame must be made stronger to withstand the increased bending moments across the platens and the ends of the frames. Consequently, there is a need for a press having a ram arrangement which enables an increased power capacity without the need for the correspondingly larger platens heretofore thought necessary.

Perony Pat. No. 2,197,441 shows a hydraulic press in which the cylinders are arranged in laterally and longitudinally extending rows, with alternate cylinders of one row extending outwardly from one platen and the remaining cylinders of the row extending outwardly from the other platen to permit adjacent cylinders in such row to be spaced apart a distance less than the sum of their outer radii. Thus, Perony makes it possible to arrange more ram cylinders within a given area outside the platen faces than can be arranged between the faces of conven- 3,523,443 Patented Aug. 11, 1970 tional platens. However, as will be aparent from the Perony patent, the working area between the inner faces of the platens is severely limited by the rods which extend from the ram in each cylinder extending from one platen to connection with the other platen. Consequently, there is a limitation on the size and shape of the die or other working forming part which may be disposed between the platens; or, conversely, Peronys platens must be made large to accommodate the work, thereby defeating the objective of reducing the size of the press. Furthermore, and as will also be apparent from the Perony patent, the pressure responsive areas of the rams must be relatively small because of the rods, so that the alleged advantage of increased power capability per unit of working area is questionable.

An object of this invention is to provide a hydraulic press having a ram arrangement which enables the power capacity of the press to be increased without a corresponding increase in platen size, but which nevertheless provides little or no obstruction to the working area between the platens.

A further object is to provide a press of the character described in the foregoing object in which the headroom need be increased, as compared with such conventional ram arrangements, not more than the stroke of the rams.

A more particular object is to provide such a hydraulic press having a compact and simplified arrangement for supplying hydraulic fluid to the ram cylinders.

A more particular object is to provide such a ram ar rangement in which the loads thereon are substantially evenly distributed between the various rams and cylinders.

These and other objects are accomplished, in accordance with the illustrated embodiment of the invention, by a hydraulic press comprising a frame having upright sides and upper and lower ends which .form a loop. Fixed platens are mounted within the loop at the upper and lower ends of the frame, and an intermediate platen is mounted within the loop for vertical movement with respect to the frame and the fixed platens. More particularly, a novel arrangement of hydraulic rams is disposed between inner faces of the one fixed platen and the movable platen so as to move the latter toward and away from work supported on the other fixed platen.

Cylinders for the rams are arranged between the platens on two levels and with their axes perpendicular to the inner faces thereof. The ram sealably reciprocable in each cylinder is in force-transmitting relation with the platen toward which the open end of the cylinder faces, and a means is provided for introducing hydraulic fluid into each cylinder so as to urge the platens in opposite directions.

Preferably, the cylinders on one level extend from the inner face of one platen, and the cylinders on the other level extend from the inner face of the other platen. More particularly, each ram sealably reciprocable in a cylinder on each level is in force-transmitting relation with adjacent cylinders on the other level.

The axis of each cylinder on each level is laterally offset from the axis of each adjacent cylinder on the other level by a distance less than the sum of the inner radius of one cylinder and the minimum outer radius of the other cylinder. More particularly, the outer walls of the rams of these adjacent cylinders are spaced apart a distance less than the minimum wall thickness. Consequently, the press of this invention has considerably greater power potential for a given working area than a press having the rams arranged in a conventional manner. At the same time, since the rams are arranged between the inner faces of the movable platen and one of the fixed platens, the opposite face of the movable platen is free from obstruction which would limit the working space between it and the other fixed platen.

In the preferred embodiment of the invention illustrated in the drawings, the cylinders are arranged in substantially parallel, longitudinally and laterally extending rows, with alternate cylinders in each row forming a first set, which are on one level to extend from the inner face of one platen, and the remaining cylinders forming a second set, which are on the other level to extend from the inner face of the other platen. Thus, each of the rams sealably reciprocable in a cylinder of the first set is in force-transmitting relation with adjacent cylinders of the second set, and each of the rams sealably reciprocable in a cylinder of the second set is in force-transmitting relation with adjacent cylinders of the first set.

In this illustrated embodiment of the invention, the axis of each cylinder in a set is spaced from the axes of adjacent cylinders in the other set by a distance which is at least equal to, but not substantially greater than, the sum of the radii of such adjacent cylinders. In this way, the rams of one set are free to move in side-by-side relation to those of the other set, so that, with the open ends of the cylinders of the sets substantially adjacent one another, this ram arrangement requires additional head room, as compared with the conventional arrangements, not substantially greater than a stroke of the rams.

A first load plate is connected to the open ends of the cylinders of the first set and to the ends of the second set of rams, and a second load plate is connected to the open ends of the cylinders of the second plate and to the ends of the first set of rams. In order to provide a substantially balanced arrangement, there are odd numbers of cylinders in each laterally and longitudinally extending row. In the interest of compactness, it is also preferred that the axes of laterally and longitudinally extending rows of cylinders be arranged in planes substantially perpendicular to one another, with the outer ends of the cylinders of each set being substantially adjacent the outer ends of the cylinders of the same set in each adjacent row.

In the drawings, wherein like reference characters are designated by like parts:

FIG. 1 is a perspective view of a hydraulic press having fixed platens at its upper and lower ends, a movable platen intermediate the fixed platen, and hydraulic rams arranged between the upper fixed platen and the movable platen in accordance with the illustrated embodiment of the present invention;

FIG. 2 is a vertical sectional view through one lateral row of the rams in closed positions, as seen along broken line 22 of FIG. 7;

FIG. 3 is a view similar to FIG. 2, but through an adjacent lateral row of closed rams, as seen along broken line 33 of FIG. 7;

FIG. 4 is a view similar to FIG. 2, but with the rams moved to open position so as to force the movable platen downwardly toward the lower fixed platen;

FIG. 5 is a vertical sectional view similar to FIG. 3, but with the rams moved to open positions, as in FIG. 4;

FIG. 6 is a horizontal sectional view of the ram arrangement, as seen along broken line 66 of FIG. 2;

FIG. 7 is a horizontal sectional view of the ram arrangement, as seen along broken line 7-7 of FIG. 2; and

FIG. 8 is a horizontal view of the ram assembly with the rams open, as seen along broken line 8-8 of FIG. 4.

With reference now to the details of the above-described drawings, and with particular reference to FIG. 1, the hydraulic press, which is indicated in its entirety by reference character 20, includes a frame 21 having uprights 21a connected at the upper and lower ends 21b and 21c, respectively, of the frame so as to form a loop. The uprights as well as the lower end of the frame are supported on a massive concrete footing 22 disposed beneath floor level 23. As illustrated in FIG. 6, the uprights 21a are made up of spaced-apart, laminated walls 24 which are interconnected by bolts 24a and held in fixed space relation by spacers 24b about the bolts.

An upper fixed platen 25 is supported by the frame beneath its upper end 2112, and a lower fixed platen 26 is supported by the lower end 21c of the frame near the floor level 23. An intermediate movable platen 27 is disposed between the fixed

platens

25 and 26 for movement vertically therebetween. All of the platens are, of course, disposed within the loop between the uprights of the frame. The movable platen 27 is forced downwardly toward the lower fixed platen 26 by means of a hydraulic ram assembly disposed between the opposite faces of the movable platen and the upper fixed platen. Thus, the lower face of the movable platen 27 is moved toward the upper face of the lower fixed platen 26 to press a work piece supported above the platen 26. This work piece may be a forging contained in a die and moved onto the upper surface of the platen 26 by means of a slide 29. A movable die may be supported from the lower face of the movable platen 27 for cooperation with the lower die in producing the desired forging.

The movable platen 27 is guided in its vertical movement within the loop by connection to a pair of vertically reciprocable guide columns 31 on each of the front and back sides of the frame uprights. More particularly, each of the guide columns 31 has a lower end received within a guide cylinder 32 mounted on the frame adjacent the uprights 21. As best shown by the breakaway of FIG. 1, the lower end of each such cylinder is closed to form a pressure chamber 33 beneath the lower end 34 of the guide column 31. Thus, with the guide column sealably slidable within the cylinder, pressure may be admitted to the chambers 33, so as to raise the columns and thus the platen 27, or exhausted therefrom to permit the guide columns to be forced downwardly, in a manner to be described.

As well known in the art, these guide columns are primarily useful in raising the movable platen 27 toward the upper fixed platen 25 upon completion of a pressing operation. For purposes of stability, the ends of the guide columns 31 are guidably slidable within outwardly extending portions of the

platens

25 and 26 on each of the front and rear sides of the frame. The corners of the movable platen 27 are provided with connectors 35 which fixedly connect to the guide columns 31.

As best shown in FIGS. 2 to 8, the ram assembly intermediate the

platens

25 and 27 comprises a first set of cylinders 36 on an upper level and extending downwardly from the lower face of platen 25, and a second set of cylinders 37 on a lower level and extending upwardly from the upper face of platen 27. Each of a first set of rams 38 is sealably reciprocable within a cylinder 36, and each of a lower set of rarns 39 is sealably reciprocable each within a cylinder 37. The axes of each of the cylinders is perpendicular to the platen face from which it extends, so that the axes of all the cylinders are parallel to one another.

More particularly, and as best shown in FIG. 8, the cylinders and rams are arranged in laterally and longitudinally extending rows, and there are odd numbers of rams in each longitudinal row as well as in each lateral row. Thus, in the illustrative embodiment of the invention shown in the drawings, there are five rams in each longitudinally extending row, and three rams in each laterally extending row, thereby providing a total of fifteen rams for exerting force between the

platens

25 and 27.

As shown in the drawings, each of the outermost and intermediate lateral rows of rams is made up of two rams 38 of the upper set and one ram 39 of the lower set. Each of the other lateral rows has one ram 38 of the upper set and two rams 39 of the lower set. Thus, there are three rams 38 in each of the outermost longitudinal rows and two in the longitudinal row. On the other hand, there are two rams 39 in each of the outermost longitudinal rows and three in the intermediate longitudinal row. Consequently, adjacent rams in each longitudinal and lateral row of rams, as seen in FIG. 8, are

alternately rams of the upper set or rams of the lower set.

As shown in FIGS. 2 to 5, a load plate 40 is connected to the open ends of each of the cylinders 36, and another load plate 41 is connected to the upper open ends of the cylinders 36. Each of the rams 39 is connected to the lower side of load plate 40, and each of the rams 38 is connected to the upper side of load plate 41. Thus, upon introduction of hydraulic fluid into each cylinder on the inner end of the ram reciprocal therein, the rams 38 transmit force through the load plate 41 to the cylinders 37 for moving the platen 27 in a downward direction. At the same time, the rams 39 transmit force through the load plate 40 to the cylinders 36 so as to assist in moving the platen 27 downwardly.

More particularly, as shown in the illustrated embodiment of the invention, the cylinder Walls are of uniform inner and outer diameters and the walls of adjacent cylinders in each row, Whether lateral or longitudinal, overlap one another. Consequently, as best shown in FIG. .8, adjacent rams in each row are tangent to one another as they move side-by-side between opened and closed positions. In this embodiment, therefore, the axes of adjacent cylinders in each row are laterally offset a distance substantially equal to the sum of their inner radii, rather than the sum of their outer radii, as in ram arrangements of conventional presses.

However, in accordance with the broader concept of this invention, the adjacent rams of each row need not be precisely tangent to one another, so long as they'are closer than the thickness of the wall of either of the cylinders in which they are reciprocable. Thus, as previously mentioned, and as it is used in the claims to define the' spacing between the axes of adjacent cylinders in each row, the expression not substantially greater than the sum of their inner radii means a distance somewhere between the sum of the inner radii of said cylinders and the sum of the radius of a ram in one of the cylinders and the outer radius of its adjacent cylinder.

As previously described, in this very compact arrangement illustrated, the outer walls of the cylinders of each set are substantially adjacent the outer walls of the cylinders of the same set in each adjacent row. Reference in this respect is directed to FIG. 6, wherein the cylinders 36 of the upper set are shown to be substantially tangent in the manner described, as well as to FIG. 7, wherein the cylinders 37 of the lower set are similarly shown. More particularly, and as is apparent from FIG. 8, the laterally and longitudinally extending rows of cylinders are disposed with their axes perpendicular to one another.

As can be seen from FIGS. 2 and 3, when the platen 27 is raised, as by means of the guide columns 31, the

rams

38 and 39 are closed" in the sense that they are fully retracted into their respective cylinders. When so retracted, the lower ends of the rams 38 of the upper set are on substantially the same horizontal level as the upper ends of the rams 39 of the lower set, and the

load plates

40 and 41 are adjacent one another.

However, upon opening of the rams due to the admission of hydraulic fluid to the cylinders, the upper and lower sets of rams are caused to move relatively in opposite axial directions. That is, although the set of rams 39 which are supported from the load plate 40 do not actually move, the set of rams 38 move downwardly to force the lower load plate 41 in a downward direction. In any case, as can be seen from FIGS. 4 and 5, when the rams 38 move downwardly, their lower ends move past the upper ends of the rams 39 and then in side-by-side relation along intermediate portions thereof.

This telescoping of the upper and lower sets of rams results in the headroom of the over-all ram assembly being increased a minimum amount. That is, since the strokes of the rams are effectively in opposite directions, the headroom will be increased only a distance equal to the height of one set of rams, at least in comparison with a conventional ram assembly having a single set of rams movable in a single direction with respect to a single series of cylinders.

In operation of the press, pressure fluid within the pressure chamber at the lower end of each cylinder may be relieved during this downward forcing of the platen 27, which is less than the permissible downward stroke of guide columns 31 within cylinders 32. Then, when the desired press has been imposed on the work piece beneath the platen 27, hydraulic fluid within the

cylinders

36 and 37 of the ram arrangement is relieved, and pressure fluid is readmitted to the pressure chambers within the cylinders 32 so as to lift the columns 31 and thus the platen 27 upwardly, thereby returning the rams to the closed position shown in FIGS. 2 and 3.

As shown in FIGS. 2 to 5, the load plate is connected to each of the cylinders 37 by means of upwardly extending bolts 40a, and each of the rams 39 of the lower series is supported from the load plate 40 by means of downwardly extending bolts 40b, the heads of which rest upon the upper side of the load plate 40. The load plate 41 is connected to the upper ends of the cylinders 37 by means of downwardly extending bolts 41a, while the load plate is supported from the lower ends of the rams 38 of the upper sets by means of upwardly extending bolts 41b.

Seal rings 400 are carried within the openings in the load plate 40 through which the rams 38 move so as to seal about them as they reciprocate within the cylinders 36. Similar rings 410 are carried within the openings of the lower load plate 41 to seal about rams 39.

Each of the cylinders 36 has its upper end located within an annular recess 42 on the lower face of platen 25 so as to locate it against sidewise displacement. It also has an inwardly extending flange within the guide recess 42 so that the hydraulic fluid acts thereon to urge the cylinder in an upward direction, thereby supplementing the mechanical connection to the platen 25. For the same purpose, the lower end of each of the cylinders 37 of the lower sets is received in an annular guide recess 43 in platen 27, and has an inwardly extending flange on its lower end exposed to hydraulic fluid therein.

The load from each of the innermost rams (indicated by A in FIG. 8) in each of the laterally and longitudinally extending rows is transmitted to four adjacent cylinders. With the exception of the corner rams (indicated by C), the outer rams (indicated by B) transmit their load to three adjacent cylinders. Each corner ram is in the upper set and transmits its load to only two adjacent cylinders. Thus, as will be apparent from FIG. 7, there are no rams of the lower set for transmitting force between the platen 27 and load plate 41.

However, as shown in each of FIGS. 1, 2, 4 and 7, posts 44 extends between these corners of the lower face of lower load plate 41 and the upper face of movable platen 27, to more evenly distribute the load transmitted between them. As shown in FIGS. 2 and 4, pins 45 at the opposite ends of the posts are retained within holes in the opposite faces of the load plate upright.

Preferably, the manifold for supplying hydraulic fluid to each of the cylinders for moving the rams to open position is disposed within the upper fixed platen 25, thereby simplifying the construction of the press. For this purpose, fluid passages 46 extending longitudinally through platen 25, as shown in each of FIGS. 2 to 5, may be interconnected with one another by means of laterally extending passages (not shown), all of which may in turn be connected with passages leading to the exterior of the platen 25 for the purpose of admitting hydraulic fluid to and exhausting it from the various cylinders.

As also shown in FIGS. 2 to 5, each of the passages 46 connects with a downwardly extending passage 47 connecting with the lower face of platen 25. Certain of the passages 47 are thus connected to the interior of cylinders 36, while others connect with the lower face of platen 25 exteriorly of the cylinders 36, and more particularly generally in alignment with the axis of a cylinder 37 of the lower set. A conduit 48 extends downwardly from each of the latter vertical passages 47 for connection at its lower end to an axial passage 49 through a ram 39, thereby connecting a lateral passageway of the manifold with the interior of a cylinder 37 of the lower set. Since each of the rams 39 is suspended from the load plate 40, which in turn is connected to the lower ends of cylinders 36, the lower end of each conduit 48 need only fit within a counterbored portion of the upper end of ram conduit 49. From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is: 1. A hydraulic press, comprising a frame having upright sides and upper and lower ends, a first platen fixed to one end of the frame, a second platen supported between the ends of the frame for movement toward and away from the first platen, cylinders arranged between the platens with their axes lying in substantially parallel, longitudinally and laterally extending planes, with alternate cylinders in each plane forming a first set extending from the inner face of one platen and the remaining cylinders forming a second set extending from the inner face of the other platen, the axes of the cylinders being parallel, a first set of rams each reciprocable in a cylinder of the first set and in force-transmitting relation with adjacent cylinders of the second set, a second set of rams each reciprocable in a cylinder of the second set and in force-transmitting relation with adjacent cylinders of the first set, means for introducing hydraulic fluid into each cylinder so as to urge said rams and thus said platens in opposite directions, means on the open end of each cylinder to provide a bore which forms a continuation of the inner diameter of the cylinder, said bore having an annular recess, and means confined in the recess for sealing about the ram reciprocable within said cylinder, the adjacent cylinder axes in each plane being laterally offset from one another by a distance less than the sum of the inner radii of said cylinders plus the radial thickness of said sealing means, so that the rams of one set may pass the rams of the other set with small clearance therebetween.

2. A hydraulic press of the character defined in claim 1, wherein the laterally and longitudinally extending planes are substantially perpendicular to one another, and the outer walls of the cylinders of each set are substantially adjacent the outer walls of the cylinders of the same set whose axes lie in adjacent planes.

3. A hydraulic press, comprising a frame having up right sides and upper and lower ends, a first platen fixed to one end of the frame, a second platen supported between the ends of the frame for movement toward and away from the first platen, cylinders arranged between the platens with their axes lying in substantially parallel, longitudinally and laterally extending planes, with alternate cylinders in each plane forming a first set extending from the inner face of one platen and the remaining cylinders forming a second set extending from the inner face of the other platen, each pair of adjacent cylinder axes in each plane being parallel and laterally or longitudinally offset by a distance not substantially greater than the sum of the inner radii of the cylinders through which the adjacent axis of each pair extend, a first set of rams each sealably reciprocable in a cylinder of the first set,

' a second set of rams each sealably reciprocable in a cylinder of the second set, a first load plate connected to the open ends of the cylinders of the first set and to the ends of the second set of rams, a second load plate connected to the open ends of the cylinders of the second set and connected to the ends of the first set of rams, and means for introducing hydraulic fluid into each cylinder so as to urge said rams and thus said platens in opposite directions.

4. A hydraulic press of the character defined in claim 3, including posts extending between the corners of one load plate and the movable platen.

5. For use in a hydraulic press, apparatus comprising a pair of oppositely facing platens relatively movable toward and away from one another, a first cylinder ex tending from the inner face of one platen, a second cylinder extending from the inner face of the other platen with its axis parallel to the axis of the first cylinder, a first ram reciprocable in the first cylinder and in forcetransmitting relation with the second cylinder, a second ram reciprocable in the second cylinder and in forcetransmitting relation with the first cylinder, means for introducing hydraulic fiuid into each cylinder so as to urge said rams, and thereby said platens, in opposite directions, means on the open end of each cylinder to provide a bore which forms a continuation of the inner diameter of the cylinder, said bore having an annular recess, and means confined in the recess for sealing about the ram reciprocable within said cylinder, the axes of said cylinders being laterally offset from one another by a distance less than the sum of the inner radii of said cylinders plus the radial thickness of said sealing means, so that the rams may pass one another with small clearance therebetween.

6. Apparatus of the character defined in claim 5, wherein said hydraulic fluid introducing means includes fluid passages in said one platen connecting with each of said cylinders.

7. For use in a hydraulic press, apparatus comprising a pair of oppositely facing platens relatively movable toward and away from one another, first and second cylinders extending from the inner face of one platen, a third cylinder extending from the inner face of the other platen, thev axis of the third cylinder being parallel to the axes of the first and second cylinders, a ram reciprocable in each of the first and second cylinders and in force transmitting relation with the third cylinder, a ram reciprocable in the third cylinder and in force-transmitting relation with the. first and second cylinders, means for introducing hydraulic fluid into each cylinder so as to urge said rams and thus said platens in opposite directions, means on the open end of each cylinder to provide a bore which forms a continuation of the inner diameter of the cylinder, said bore having an annular recess, and means confined in the recess for sealing about the ram reciprocable within said cylinder, the axis of the third cylinder being laterally ofiset from the axis of the first cylinder by a distance less than the sum of the, inner radii of said third cylinder and said first cylinder, respectively, plus the radial thickness of said sealing means, and the axis of the third cylinder being laterally offset from the axis of the second cylinder by a distance less than the sum of the inner radii of the third cylinder and second cylinder, plus the radial thickness of said sealing means, so that the ram reciprocable in the third cylinder may pass each of the rams reciprocable in the first and second cylinders, respectively, with small clearance therebetween.

8. Apparatus of the character defined in claim 7, wherein the axes of the three cylinders lie substantially on one plane.

9. Apparatus of the character defined in claim 7, wherein the outer walls of the first and second cylinders are substantially adjacent one another.

'10. For use in a hydraulic press, apparatus comprising a pair of oppositely facing platens relatively movable toward and away from one another, first and second cylinders extending from the inner face of one platen, third and fourth cylinders extending from the inner face of the other platen, the axes of the cylinders being parallel, a ram reciprocable in each of the first and second cylinders and in force-transmitting relation with the third and fourth cylinders, a ram reciprocable in each of the third and fourth cylinders and in force-transmitting relation with the first and second cylinders, means for introducing hydraulic fluid into each cylinder so as to urge said rams and thus said platens in opposite directions, means on the open end of each cylinder to provide a bore which forms a continuation of the inner diameter of the cylinder, said bore having an annular recess, and means confined in the recess for sealing about the ram reciprocable within said cylinder, the axis of each of the first and second cylinders being laterally offset from the axis of each of the third and fourth cylinders a distance less than the sum of the inner radii of said first cylinder and each of said third and fourth cylinders, respectively, and the second cylinder and each of said third and fourth cylinders, respectively, plus the radial thickness of said sealing means, so that the rams reciprocable in the first and second cylinders may pass the rams reciprocable within the third and fourth cylinders with small clearance therebetween.

11. Apparatus of the character defined in claim wherein the outer walls of the first and second cylinders are substantially adjacent one another, and the outer walls of the third and fourth cylinders are substantially adjacent one another.

12. A hydraulic press, comprising a pair of oppositely facing platens relatively movable toward and away from one another, nine cylinders arranged between the platens with their axes lying substantially parallel in longitudinally and laterally extending planes of three each, the corner and center cylinders forming a first set and extending from the inner face of one platen and the remaining cylinders forming a second set and extending from the inner face of the other platen, each pair of adjacent cylinder axes in each plane being parallel and laterally or longitudinally offset a distance not substantially greater than the sum of the inner radii of cylinders through which the adjacent axes of each pair extend, a first set of rams each sealably reciprocable in a cylinder of the first set, a second set of rams each sealably reciprocable in a cylinder of the second set, a first load plate connected to the open ends of the cylinders of the first set and to the ends of the second set of rams, a second load plate connected to the, open ends of the cylinders of the second set and connected to the ends of the first set of rams, and means for introducing hydraulic fluid into each cylinder so as to urge said rams and thus said platens in opposite directions.

13. Apparatus of the character defined in claim 12, wherein the load plates are substantially adjacent one another when the rams are fully retracted in their cylinders.

14. Apparatus of the character defined in claim 12, including means carried by the load plates for sealing about the rams.

15. Apparatus of the character defined in claim 12, wherein said means for introducing hydraulic fluid includes fluid passages in said one platen connecting with each of said cylinders.

16. A ram assembly for a hydraulic press having a pair of oppositely facing platens relatively movable toward and away from one another, comprising a first cylinder having a first ram reciprocable therein, said first cylinder being adapted to extend from the inner face of one platen, a second cylinder having a second ram reciprocable therein, said second cylinder being adapted to extend from the inner face of the other platen, the axes of the first and second cylinders being parallel to one another and laterally offset from one another a distance not substantially greater than the sum of the inner radii of said cylinders, a first load plate connected to the open end of the first cylinder and to the second ram and surrounding the first ram, a second load plate connected to the open end of the second cylinder and to the first ram and surrounding the second ram, and means sealing between each ram and the cylinder in which it reciprocates so that, upon introduction of hydraulic fluid into each cylinder, the rams and thus the platens from which they are adapted to extend, are urged in opposite directions.

17. Apparatus of the character defined in claim 16, wherein said sealing means is carried on said load plates.

18. A hydraulic press, comprising a frame having upright sides and upper and lower ends, a first platen fixed to one end of the frame, a second platen supported between the ends of the frame for movement toward and away from the first platen, cylinders arranged between the platens on two levels and with their axes perpendicular to the inner faces thereof, the axis of each cylinder on each level being laterally offset from the axis of each adjacent cylinder on the other level by a distance less than the sum of the inner radius of one cylinder and the minimum outer radius of said adjacent cylinder, a ram sealably reciprocable in each cylinder and in force-transmitting relation with the platen toward which the open end of the cylinder faces, a first load plate connected to the open ends of the cylinders on one level and to the ends of the rams reciprocable in the cylinders on the other level, a second load plate connected to the open ends of the cylinders on said other level and connected to the ends of the rams reciprocable in the cylinders on said one level, and means for introducing hydraulic fluid into each cylinder so as to urge said platens in opposite directions.

19. Apparatus of the character defined in claim 18, wherein the outer walls of the cylinders on each level are substantially tangent to the outer walls of adjacent cylinders in the same level.

20. Apparatus of the character defined in claim 18, wherein the cylinders on one level extend from the inner face of one platen and the cylinders on the other level extend from the inner face of the other platen, and each ram sealably reciprocable in a cylinder on each level is in force-transmitting relation with adjacent cylinders on the other level.

21. For use in a hydraulic press, apparatus comprising a pair of oppositely facing platens relatively movable toward and away from one another, first and second cylinders disposed between the inner faces of the platens with their axes perpendicular to said faces, said cylinders being on different levels between the platens and having their axes parallel to one another, first and second rams reciprocable in the first cylinder and second cylinder, respectively, and in force-transmitting relation with the platen toward which the open end of said cylinder faces, means for introducing hydraulic fluid into each cylinder so as to urge said platens in opposite directions, means on the open end of each cylinder to provide a bore which forms a continuation of the inner diameter of the cylinder, said bore having an annular recess, and means confined in the recess for sealing about the ram reciprocable within said cylinder, the axes of said cylinders being laterally offset from one another by a distance less than the sum of the inner radii of said cylinders plus the radial thickness of said sealing means, so that the rams may pass one another with small clearance therebetween.

22. Apparatus of the character defined in claim 21, wherein one of said cylinders extends from the inner face of one platen and the other extends from the inner face of the other platen, and the ram sealably reciprocable in said one cylinder is in force-transmitting relation with the other cylinder and the ram sealably reciprocable in said other cylinder is in force-transmitting relation with the one cylinder.

- 23. Apparatus of the character defined in claim 22, wherein the open ends of the cylinders lie in substantially the same plane when the rams are retracted therein.

24. Apparatus of the character defined in claim 22, wherein the sides of the rams are substantially tangent to one another.

25. For use in a hydraulic press, apparatus comprising a pair of oppositely facing platens relatively movable toward and away from one another, three cylinders disposed between the inner faces of the platens with their axes perpendicular to said faces, the first and second of said cylinders being on one level between the platens and the third cylinder being on another level therebetween, the axis of each cylinder being parallel to the axis of the other cylinders, a ram reciprocable in each of the cylinders and in force-transmitting relation with the platen toward which the open end of said cylinder faces, means for introducing hydraulic fluid into each cylinder so as to urge said platens in opposite directions, means on the open end of each cylinder to provide a bore which forms a continuation of the inner diameter of the cylinder, said bore having an annular recess, and means confined in the recess for sealing about the ram reciprocable within said cyl inder, the axis of the third cylinder being laterally offset from the axis of the first cylinder by a distance less than the sum of the inner radii of said third cylinder and said first cylinder, plus the radial thickness of said sealing means, and the axis of the third cylinder being laterally offset from the axis of the second cylinder by a distance less than the sum of the inner radii of the third cylinder and second cylinder, plus the radial thickness of said sealing means, so that the ram reciprocable in the third cylinder may pass each of the rams reciprocable in the first and second cylinders, respectively, with small clearance therebetween.

26. Apparatus of the character defined in claim 25, wherein the outer walls of the first and second cylinders are substantially tangent to one another.

27. Apparatus of the character defined in claim 25, wherein the first and second cylinders extend from the inner face of one platen and the third cylinder extends from the inner face of the other platen, and each of the rams sealably reciprocable in said first and second cylinders is in force-transmitting relation with the third cylinder and the ram sealably reciprocable in the third cylinder is in force-transmitting relation with at least one of the first and second cylinders.

28. A hydraulic press, comprising a frame, a first platen fixed to the frame, a second platen mounted on the frame for movement toward and away from the first platen, a first set of cylinders extending from the inner face of the first platen, a second set of cylinders extending from the inner face of the second platen with their axes parallel to the axes of the first set, a ram sealably slidable within each cylinder, means for introducing pressure fluid into each cylinder so as to move the ram there in relative to the platen from which said cylinder extends, a first load plate connected to the open ends of the cylinders of the first set and to the ends of the rams slidable in the cylinders of the second set so as to transmit the forces on said rams through said cylinders of said first set and thereby to the fixed platen, and a second load plate connected to the open ends of the cylinders of the second set and connected to the ends of the rams slidable in the cylinders of the first set, so as to transmit the force on said rams through said cylinders of the second set and thereby to the movable platen.

29. For use in a hydraulic press, apparatus comprising a pair of oppositely facing platens relatively movable toward and away from one another, a first cylinder extending from the inner face of one platen, a second cylinder extending from the inner face of the other platen, the axes of said first and second cylinders being parallel, a ram slidable within each cylinder, means for introducing pressure fluid into each cylinder so as to move the ram therein relative to the platen from which said cylinder extends, means connecting the ram in the first cylinder to the second cylinder so as to transmit the force on said ram through said second cylinder and thus to said other platen, means connecting the ram in the second cylinder to the first cylinder so as to transmit the force on said ram through said first cylinder and thus to said one platen, means on the open end of each cylinder to provide a bore which forms a continuation of the inner diameter of the cylinder, said here having an annular recess, and means confined in the recess for sealing about the ram reciprocable within said cylinder, the axes of said cylinders being laterally offset from one another by a distance less than the sum of the inner radii of said cylinders plus the radial thickness of said sealing means, so that the rams may pass one another with small clearance therebetween.

References Cited UNITED STATES PATENTS 2,197,441 4/ 1940 Perony 72453 3,205,749 9/ 1965 Schenk 72-453 3,274,819 9/ 1966' Knowles 72453 3,333,457 8/1967 Allen 72-453 3,338,573 8/1967 Lukas 100269 CHARLES W. LANHAM, Primary Examiner G. P. CROSBY, Assistant Examiner US. Cl. X.R. 72455; 100269'