US3150412A

US3150412A - Radial press

Info

Publication number: US3150412A
Application number: US113768A
Authority: US
Inventors: Donald H Newhall
Original assignee: Harwood Engineering Co
Current assignee: Harwood Engineering Co
Priority date: 1961-05-31
Filing date: 1961-05-31
Publication date: 1964-09-29
Anticipated expiration: 1981-09-29

Description

Sept. 29, 1964 D. H. NEWHALL 1 RADIAL PRESS Filed May 51, 1961 5 Sheets-Sheet l Septv 1964 D. H. NEWHALL' 3,150,412

" RADIAL PRESS Filed May 31, 1961 jo j! 5 Sheets-Sheet 2 P 29, 1964 D. H. NEWHALL 3,150,412

RADIAL PRESS Filed May 31, 1961 5 Sheets-Sheet 3 D. H. NEWHALL Sept. 29, 1964 RADIAL PRESS 5 Sheets-Sheet 4 Filed May 31, 1961 Sept. 1964 D. H. NEWHALL 3,150,412

RADIAL PRESS Filed May 51, 1961 5 Sheets-Sheet 5 United States Patent 3,150,412 RADIAL PRESS Donald H. Newhali, Walpole, Mass, assignor to Harwood Engineering Qompany, Walpole, Mass., a corporation of Massachusetts Filed May 31, 1961, @er. No. 113,763 7 Claims. (Cl. 18-455) The present invention relates to improvements in a high pressure press.

It is a principal object of the invention to provide a press which is of simple and efficient construction, is compact, and at the same time capable of effecting a substantial compression of the subject material at the very high pressures required which may amount to several million pounds per square inch, and which is capable of producing these results with a minimum expenditure of power.

It is a further object of the invention to provide a high pressure press of this general description having a plurality of cooperating wedge-shaped press members hereinafter referred to as punches in which there is provided a novel, and effective means to apply pressures of the same amount simultaneously to a plurality of said press members and thereby to generate the desired pressure in a sample under test.

In accordance with the objects above noted, a feature of the invention consists in the provision of a novel pressure applying means in the form of a pressure exerting cylinder within which are fitted a series of tapered punches having space enclosing tips, in combination with a suitable means for exerting a powerful compressive pressure against said cylinder evenly about the periphery thereof, which will effectively reduce the diameter of the cylinder and thereby produce an identical inward movement of each individual punch at a uniformly graded pressure. f

In the preferred form of the invention shown the pressure exerting cylinder assembly comprises a metallicpressure exerting cylinder which is surrounded by a jacket through which fluid under pressure is applied to compress the cylinder wall into a substantially reduced diameter within the limits of resiliency of the material employed, and thereby to exert a corresponding compressive pressure on the punches contained within said cylinder.

It is another object of the invention to provide a high pressure press of the general type illustrated in which punches may be readily substituted for one another from a large selection of punches of different kinds for the processing of samples of many different shapes and sizes and under widely varying conditions.

With these and other objects in View as may hereinafter appear, the several features of the invention consist in the devices, combinations and arrangements of parts hereinafter set forth which together with the advantages to be obtained thereby will be readily understood by one skilled in the art from the following description taken in connection with the accompanying drawings, in which:

' FIG. 1 is a perspective view of a high pressure press embodying therein the several features of the invention; FIG. 2 is a fragmentary view in elevation and partly in section illustrating one of the supporting and centering springs for the pressure cylinder;

FIG. 3 is a detail exploded perspective view of two axially opposed punches and the spacer members associated therewith;

FIG. 4 is a view in front elevation partly in section of a radial press embodying the several features of the invention;

punches fully compressed.

3,150,412 Patented-Sept. 29,- 1964 FIG. 5 is an enlarged detail sectional view illustrating particularly the jacketed pressure cylinder together with the press members shown in FIG. 7;

FIG. 6 is a sectional view taken on a line 6-6 of FIG. 5;

FIG. 7 is an exploded perspective view of the wedgeshaped press members;

FIG. 8 is a diagrammatic sectional plan view similar to FIG. 7, showing the load distribution through the wedge-shaped punches;

FIG. 9 is a view similar to FIG. 8 but showing the load distribution when the air spaces between adjacent punches are closed;

FIG. 10 is a detail sectional side view of a cylindrical sample made up to test a specimen wire;

FIG. 11 is a diagrammatic View in vertical section illustrating one method of providing additional pressure support for the vertical punches, in a system adapted for the testing of a cylindrical sample;

FIG. 12 is a diagrammatic plan sectiontaken on a line 12-12 of FIG. 11 illustrating horizontally acting punches having a concave tip portion to receive said cylindrical sample;

FIG. 13 is a fragmentary sectional plan view showing a modified form of punch including a hard steel base portion and a carbide tip portion;

FIG. 14 is a plan section taken on a line 1414 of FIG. 13;

FIG. 15 is a sectional view in elevation of the pressure cylinder having mounted thereon four punches engaging a sample having the shape of a tetrahedron;

FIG. 16 is a plan section taken on a line 16-16 of FIG. 15;

FIG. 17 is a sectional view in elevation illustrating an arrangement of eight punches in applicants press adapted for testing an eight-sided sample; v FIG. 18 is a plan section taken on a line 1818 of FIG. 17;

. FIG. 19 is a fragmentary View of a spherical sample tested by the arrangement of punches shown in FIGS. 17 and 18 but with the tips formed as concaved spherical segments;

FiG. 20 is a sectional view in elevation illustrating an alternative arrangement of six punches adapted for the testing of a spherical sample;

1 FIG. 21 is a plan section taken on a line 21-21 of FIG. 20;

FIG. 22 is a sectional view in elevation illustrating an arrangement of six punches in which the horizontally arranged punches within the pressure cylinder are first moved inwardly to a maximum pressure position, and further pressure is then applied through the two end punches;

FIG. 23 is a sectional view taken on a line 23-23 of FIG. 22, the press being shown in open position;

FIG. 24 is a view similar to FIG. 23, but with the horizontally disposed punches fully compressed;

FIG. 25 is a sectional view in elevation of a radial press having six punches which are adapted to be first brought to a fully compressed position and thereafter additional pressure applied, as for example by heating the sample with crossing electrical currents;

FIG. 26 is a plan section. of FIG. 25 taken on a line 26-26 of FIG. 25, the several punches being shown in their open position; and

FIG. 27 is similar to FIG. 26, but with the several The invention is herein disclosed as embodied in a multiple punch type apparatus which comprises a plurality of punches disposed in a spaced enclosing relation in a single plane, which for convenience of illustration will be assumed to be a horizontal plane, each said punch having tapered sides for fitting said punches together to form said enclosed space, and two end punches cooperating with said plurality .of punches, which for convenience of illustration will be assumed to operate vertically. Said end punches and said plurality of circularly arranged punches have additionally tapered surfaces which fit together in such a manner as to further enclose said space. The faces of the several punches above described when moved toward one another define a reaction chamber in which a specimen material is placed to be subjected to high pressures.

A feature of the illustrated construction consists in the provision of a novel and highly effective device for applying pressure against a plurality of circularly arranged punches, which takes the form of a pair of coaxial cylinders, surrounding the horizontal punches, the axis of the cylinders being normal to the plane of the punches, the inner cylinder being in contact with the bases of the punches, with an arrangement of conical shoulders or abutments on the cylinders and associated packing therewith so as to form a fluid jacket or envelope, as particularly shown in FIGS. 5, 11 and 13, which acts, when fluid under heavy pressure is forced into said jacket or envelope, to bow the wall of the inner cylinder inwardly and thereby to force each of the four horizontal punches inwardly under an exactly equalized compressive pressure.

In the illustrated construction pressure is applied to the vertically movable punches by means of a press including a fixed bottom punch plate and a vertically movable top plate.

Another feature of the invention consists in the construction and arrangement of the radial press assembly including the pressure cylinder, the multiple horizontally arranged punches contained therein, and the cooperating axially acting punches, to produce an accurate positioning of the several elements of said assembly with relation to a sample and with the equal spacing required between adjacent punches to insure the utmost unimpeded advance and most efiicient effort of each of said punches.

The radial press illustrated in the drawings as embodying in a preferred form the several features of the invention comprises a cylindrical punch containing assembly 29 supported on a vertical axis and having an inside compression cylinder 22, referred to as the jacketed cylinder, and an outside jacket supporting cylinder 24-, referred to as the jacketing cylinder, as shown in FIG. 5. The inside jacketed cylinder 22 is formed at its upper end with a portion of larger diameter providing a shoulder 26. The outside jacketing cylinder 24 is formed at its down end with a portion of smaller diameter providing a shoulder 28.

The annular space enclosed between the inside cylinder 22 and outside cylinder 24, and bounded at the ends by the abutments 26, 28 provides a jacket 36 adapted to receive fluid under very high pressure. The two ends of the jacket are sealed in by means of suitable packings 32 and 34. The inside jacketed cylinder 22 is made sufiiciently thin to be strain-sensitive to the pressure exerted by a medium introduced into the jacket, so that the diameter of the internal surface will become appreciably smaller as the jacket pressure is increased. The outside jacketing cylinder 24 is made up of substantially thicker walls of metal and provides an outer shell of great strength capable of withstanding the greatest jacket pressure which may be applied.

Contained within the jacketed cylinder 22 are four press members or

punches

36, 38, 4t) and 42, pyramidally shaped, which are disposed about the inner periphery of the jacketed cylinder 22 to substantially enclose a central area within the cylindrical assembly 20 in a horizontal plane. The outer faces of the respective punches 36 to 42 inclusive are formed as segments of a cylinder and are normally in contact with the inner surface of the jacketed cylinder 22. For the retracted oil-pressure position of the press shown in FIGS. 5 and 6, for example, the punches 3t], 33, st) and 42 are spaced apart from one another. As pressure is applied through the jacket 3%) the jacketed cylinder 22 is con ted so that the punches move inward- 13/, at the same time reducing but not wholly closing the spaces therebetween.

For fully enclosing, and for applying pressure to said central area vertically, two

additional punches

44 and 46 are provided, loosely mounted within the cylindrical chamber for axial movement relative thereto. Each of

sai riches

44 and 46 is formed with a tapered end portion which is fitted with relation to corresponding tapers formed on the respective top and bottom sides of the transversely acting punches 36, 33, 4t 42, and with a cylindrical base portion which is loosely fitted into the jacketed cylin for axial movement relative thereto.

As best shown in FIG. 5, the bottom punch 46 is fixedly mounted on a base 48 being held in position by ring 49 secured to the base which also carries four

upright guide posts

59, 51, 52, and 53 A crosshead 54- is rigidly connected across the upper ends of the

guide bars

50, 51, 52 and 53, to form a rigid frame which includes the base -33, guide posts, and crosshead 54.

The upper vertical punch 34 is secured to a crosshead which is guided upon and is vertically movable with relation to said guide posts 50, 52.. The punch 44 and crosshead 56 are connected to a ram 58 and ram cylinder 6% which is secured to the fixed crosshead 54. Fluid under pressure is admitted to the cylinder 60 by means of an inlet pipe 62 in order to apply pressure through the vertical punches 4-4, 46. A second pressure supply pipe 61 is connected with the lower end of the cylinder 69, so that pressure may be applied when so desired to move the vertical punch upwardly and thereby to relieve the pressure applied against the central area of the press, and for the entire removal of the punch 44 to facilitate the loading and removal of specimens from the press.

It will be understood that the cylindrical assembly 20 is freely adjustable vertically as a unit so that the

punches

36, 38, it) and 42 operating in a horizontal plane will be automatically centered with relation to the two

vertical punches

44, 46 as the upper punch 44 moves downwardly with relation to the stationary punch 46, to apply pressure through the press.

The several punches may be readily centered in assembly with relation to each other by means of two spacing members 63 and 64 (see FIG. 3) which are made of a light corrugated material and are readily crushed when pressure is applied. The spacing member 63 is in the shape of a truncated hollow pyramid which fits snugly over the tip portion of the bottom punch 46. Each of the laterally acting punches is then dropped into position together with the sample. Next the spacing member 64 is introduced, and finally the top punch 44, which is thus accurately positioned with relation to the lateral punches. The press is now ready for operation.

The entire cylindrical punch containing assembly 20 is movably supported to assume at all times a mean position between the top and

bottom punches

44, 46 which are located respectively by

rings

65 and 66 on the cross head 56 and base 48. To this end four vertically disposed supporting springs including springs 67, 68 (see FIGS. 1 and 2) are secured at equally spaced intervals about the periphery of the cylindrical punch containing assembly. Each spring is secured at its center to the said assembly at the mid-portion thereof and has bowed upper and lower end portions which engage respectively with the crosshead 56 and base 48. The assembly is thus freely adjustable both vertically and horizontally with relation ot the vertical punches.

The inner or jacketed cylinder which is preferably made of steel, may be reduced in diameter under pressure by a substantial amount, without exceeding the clastic limit of the material, thus imparting a movement of equal and substantial extent to each of the

several punches

36, 38, 40 and 42 engaged thereby.

An example of the manner in which the applicants radial press will operate is illustrated by the following example:

The radial press as shown specifically in FIGS. 1 to 7 inclusive, but'employing the carbide tipped punches of FIGS. 13 and 14 of the drawings is assumed to have a jacketed cylinder 22 with an internal diameter of 25 inches and a wall thickness of 1 inch. Said cylinder acts through composite punches, each having a cylindrical steel base 101 (see FIGS. 13 and 14) and a cemented carbide tip 102, 2.5 inches thick, upon a cubical sample of pipestone, silver chloride, or other material having the same compressibility, and having a volume of 3 cubic inches (each side being 1.443 inches across). Assuming that a jacket pressure of 20,000 p.s.i. is applied, the sample will be subjected to a pressure of 1,500,000 p.s.i. Under these conditions the compression of the sample will amount to .084 inch on a side and the loss in volume will amount to 17%.

The apparatus above described is capable of developing suificient pressure to enable an investigator to examine a wide range of material phenomena such, for example,'as polymorphic transitions known to exist in materials such as barium, caesium, carbon, bismuth and many other substances. The diamond from carbon is a, well-known example of such a transition. The apparatus is simple and economical both in construction and operation, is readily assembled and. disassembled, and lends itself most etfectively to a wide range of experimental techniques. The jacketed construction described further provides a maximum safeguard against hazards resulting from failure of material at the high pressures necessarily employed.

An important feature of the construction shown, for example, in FIG. 6 consists in the small spaces indicated at 71 between adjacent punches. In this figure a block 72 of somewhat plastic pressure resistant material, for example, talc, pipestone, silver chloride or pyrophyllite, containing a specimen, not shown, is placed in the enclosed area in contact with each of the four punches 36 to 42 inclusive. The top and

bottom punches

44, 46 are similarly brought into the press start position shown in FIG. in which small spaces indicated at 73 are provided. The spaces 71 and 73 above referred to are chosen of such width that the adjacent punches do not touch one another during t e advancing or pressure applying movement of the punches. As long as the punches do not touch, the force from the jacket pressure transmits a radial force only which is directed against the specimen containing block. Should the punches touch, some of that force would be dissipated in making a tangential load on ethe punches (see FIG. 9), and but little, if any, force would reach the sample, depending upon the area in contact and the ductility of the material in contact.

It will be understood that the distribution of forces in each punch is such that the small tip portion is required to carry the heaviest loads. Added lateral support is provided for the heavily stressed tip portion of the punch by permitting a small amount of filling material to flow terial.

into the spaces between said punches adjacent said tips.

So long as the air space between adjacent punches is otherwise maintained, the loss of pressure applied against the sample as a result of the lateral pressure thus applied is well compensated for in the added support afforded to the heavily stressed tip of the punch. Assuming that pipestone or pyrophyllite is employed in the construction of the sample, it is well known that as pressure is built up, a small amount of this material will fiow into the ends of said separating spaces thus providing the required lateral support for the heavily stressed tips of the punches.

FIGS. 11 and 12 illustrate an arrangement of the press assembly in which a cylindrical space is enclosed by the horizontally disposed punches, the ends of said space ple 106 under a very high pressure.

being enclosed by two vertically disposed punches. The

horizontally disposed punches designated generally at 74, 75, 76 and 77 are each formed of hard steel and with arcuately shaped tip segments of carboloy designated respectively at 78, 7%, 80 and 81. These carboloy tips as best shown in FIG. 12 are arcuately shaped to engage with a cylindrically shaped sample 82. The horizontally disposed punches above described are supported within a pressure cylinder which may be the pressure cylinder 22 of FIGS. 4, 5 and 6 and are separated as best shown in FIG. 12 by spaces 83 which are of suificient width to permit an unimpeded inward movement of the punches. The assembly shown in F168. 11 and 12 is further provided with two vertical punches including a vertically movable top punch 84 and a bottom punch 86. These punches are cylindrically formed with tapered portions which are arranged to fit into arcuately shaped end portions of the transverse punches 74 to 77 inclusive. As best shown in FIG. 11, each of said

vertical punches

84 and 86 is provided with a straight cyiindrical end portion which is fitted within the ends of carboloy tips 78 to 81, inclusive, for engagement with the two ends of the sample 82. In this form of the device, means are provided for strengthening the two end portions at the point of intersection of the cylindrical tip and the tapered base portion. A relatively plastic ring S8 is fitted to the upper ends of the carboloy tip portions '78 to 81 inclusive in the clearance space provided between the vertical punch 84. and the associated horizontally disposed punches '74 through 77 inclusive. When the punch 84 is moved downwardly to exert an endwise pressure on the cylindrical sample 82, the plastic ring 88 being compressed between said surfaces will flow sufiiciently to provide a transverse support for the relatively weak intersection of the cylindrical and tapered portions of punch 84. The lower vertical punch 86 similarly is given additional lateral support by means of a plastic ring 96) which abuts the lower ends of the carboloy inserts 78, 79, 80, 81, and

provides a similar support for the intersecting cylindrical and tapered portions of the lower vertical punch 86.

FIGS. 13 and 14 illustrate still another construction of the load bearing tip portions of the several cooperating punches. In these views the body of the punch 101 is made of hard steel and the entire tip portion 102 is made of a very hard material, as for example, tungsten carbide. A typical operation which may be carried out in accordance with the invention will be described in connection with FIG. 10 of the drawings. A specimen wire 104 is tested for resistance as a function of temperature and pressure. A sample 106 is prepared which comprises the specimen wire 104 embedded in suitable pressure transmitting material 108 such as silver chloride, and the ends of the wire are connected to

metallic discs

110, 112 connected into a suitable electric circuit (not shown). The cylindrical package thus formed is then wrapped in a layer of insulating material 114 which is also ductile to ensure the transmission of pressure through the ma- The sample is then completed by adding a thick layer of a suitable tough pressure transmitting material such as talc, pipes-tone, or pyrophyllite.

When the specimen is positioned in the press and pressure is now applied to the radially disposed

punches

74, 75, 76 and 77 by the introduction of fluid under pressure into the jacket 30, and is applied to the vertically arranged

punches

84 and 86 by the introduction of fluid under pressure into the upper end of ram cylinder 60 (FIG. 4), the several punches are forced inwardly placing the sam- The contraction of the inner jacketed cylinder insures an equal advance of each of the four punches engaged thereby and an exactly balanced even pressure against all portions of the sample about said transverse periphery. The pressure of the fluid introduced into the upper end or" the ram cylinder 60 is adjusted to cause the two end punches to exert an identical pressure against the two ends of the sample.

As the pressure is increased, a small amount of the outer layer 116 of the sample, for example, pyrophyllite is forced into spaces between adjacent punches thus providing transverse support for tip portions thereof.

It will be understood that the space enclosed by the cooperating punches of a press suitable for carrying out the test above described is not necessarily in the shape of a cube, may for example, be cylindrical in shape and much longer than it is wide. The test shown in FIG. may be carried out without the use of pressure exerting vertical punches, or with such punches employed only to prevent extrusion of the sample endwise.

Assuming that power is now passed through the specimen wire 104 to heat the wire, the temperature generated by the electric current, and the voltage drop across the ends of the wire can readily be observed as pressure and temperature are varied, thus disclosing the desired resistance parameters.

The radial press assembly herein illustrated is well adapted for operation with many different arrangements and shapes of punches for operation on many different kinds and shapes of sample to be tested.

One general form of sample having four or more triangular surfaces against which pressure is applied is the right pyramid. FIGS. and 16 illustrate one form of such a sample in the form of a tetrahedron 111 which is shown as an inverted three-sided pyramid. The punch assembly comprises three horizontally

movable punches

113, 115 and 117 spaced around the interior face of the pressure cylinder 22, and having the bottom surfaces thereof arranged to slide on the base plate 48 of the press. A thin sheet of Tellon, or a similar lubricating material such as molybdenum sulphide or colloidal copper, is inserted between the base plate 48 and the

movable punches

113, 115 and 117. These materials, and particularly Teflon, my be expected to insure an easy sliding movement of said punches irrespective of the amount of the down load imposed thereon. With this arrangement a single vertically acting punch 118 is provided which acts against the three

punches

113, 115 and 117 supported as above noted on the base plate 48. The proportions and shape of the right pyramidal sample to be tested may be readily varied by a choice in the number of transverse punches employed to produce a four or five or more sided pyramid. The height of the sample as compared to its base area may readily be increased to increase the proportion of the lateral pressure applied as compared with the vertical pressure required to offset the vertical thrust component of the three horizontal punches 1E3, 115 and 117.

FIGS. 17 and 18 illustrate another arrangement of the punches contained within the pressure cylinder assembly to obtain a more evenly distributed pressure throughout a rhombic sample to be tested. In this embodiment of the invention eight punches are employed, an upper set of four punches including punches 120, 122 and two additional punches not shown and a lower set of four

punches

128, 130, 132 and 134, said punches having spaces therebetween to permit an unimpeded compressive inward movement of said punches. A vertical ram 136 is arranged to exert a downward pressure on the upper group of punches including 1211*, and 122, the lower group of punches being supported on the fixed base 48 of the press. A thin sheet of lubricating material 138 such as Teflon is preferably placed between the ram 136 and the upper group of punches, and a similar sheet of lubricating material 140 is mounted between the base 48 and the lower group of punches 128 to 134- inclusive to avoid frictional loss as a result of vertical pressures. A Teflon film is preferably placed also between each of the punches and the engaging inner load bearing surface of the pressure cylinder to facilitate axial movement of said punches with relation to the cylinder wall. It will be noted that the rhombic sample 142 may be separated across the transverse axis to provide two right four-sided pyramids. This construction is of particular value because of the elficient distribution of force throughout the sample and further because of the ease of assembly of the sample to be tested and the punches therewith within the pressure cylinder 22. The arrangement of the punches in this construction is such that the punches tend to be selfcentering so that no separating element is necessary to provide equal air spaces between said punches prior to the application of pressure thereto.

FIG. 19 illustrates a variant of the construction illustrated in FIGS. 17 and 18 in which the tungsten carbide tips of the eight punches employed are shaped to form an enclosed space which is spherical in shape. This form has the imponant advantage that the stresses set up in the sample by the operation of the several punches are evently distributed and are equalized throughout the mass of the sample. The actual pressure to which one or more specimens embodied in the sample may be subjected is more readily calculated and controlled, and the risk of fracture of the sample or of adjacent portions of the apparatus is greatly minimized.

FIGS. 20 and 21 illustrate another embodiment of the invention in which a spherical sample is tested. This embodiment comprises four horizontally disposed punches 15%, 152, 154 and 156, each being formed of a hard steel base and a carboloy tip which is concave to form a spherical segment. In this form of the device two vertical punches 158 and 169 are provided which are formed f hard steel with carboloy tips concaved to close the top and bottom punches of this spherical cavity. The spherical construction shown provides for a most efficient application of the impressive force throughout all portions of the sample to be tested.

FIGS. 22 to 27 inclusive illustrate still another embodiment of the invention in which the several punches contained within the pressure cylinder are subjected to compressive forces suflicient to advance the punches inwardly to a position in which they become self-supporting and capable of withstanding a further substantial increase of pressure. Such further increase in pressure may be effected mechanically, as particularly illustrated in FIGS. 22 to 24 inclusive, or in some instances by heating the sample, as for example, by electrical means as shown in FIGS. 25 to 27 inclusive. Referring particularly to FIGS. 22 to 24, an arrangement of six punches is shown mounted within the pressure cylinder including four radially disposed punches 17ll, 2'72, 174 and 176. Said radially disposed punches are constructed and arranged with relatively wide spaces separating them except for the internal or tip portions of said punches which are separated by much smaller spaces indicated at 180. The radial punches and the spaces are so proportioned that a compressive inward movement of said punches to their inmost position will cause said spaces 180 to be entirely closed. The tip portions of the radial punches 1769 to 176, as specifically shown in FIG. 24, will then be engaged with one another and each tip will thus derive additional support from its pressure contact with the adjacent punches on both sides thereof. In this embodiment of the invention the two

vertical punches

182, 184 are adapted now to be forced relatively toward one another to still further increase the total pressure exerted against a sample 186.

In the alternative construction of FIGS. 25 to 27 inclusive the same radial punches 1'70 to 176 may be employed, but two vertical punches 128, in this instance will be similarly formed to provide a relatively wide separation of the vertical from the horizontal punches throughout the outer portions of the punches, but a relatively small separation at tip portion thereof. It is here assumed that all of the punches are moved inwardly under the influence of a compressive force which will move the several punches simultaneously to a fully compressed 9 position as show nin FIG. 27 in which the tip portions of all of said punches will engage with one another under high pressure to provide a maximum of lateral support for said tip portions. In this case an electric circuit is employed to apply a substantial amount of concentrated heat to the sample. The circuit employed comprises two

electrodes

192, 193 connected respectively to radial punches 17d and 174. Further, in this form of the device, a cooling water jacket 200 is provided around the pressure cylinder to draw off excess heat generated in the process. In this form of the device, pressure is initially applied against a sample 202 mechanically by the simultaneous advance of each of several punches in response to the application of a compressive force until said punches reach a fully compressed position in which the tip portion of each punch is engaged with and derives a substantial lateral support from said contact with each punch adjacent thereto. Thereafter the electric circuit is energized applying an electrical heating current to the sample which is thus caused to expand with a consequent rapid further rise of the pressure load to which the said punches are subjected.

The invention having been described what is claimed is:

1. In a high pressure press, the combination of a pressure applying assembly for directing pressure against an enclosed space including a pressure applying metallic cylinder having load bearing internal wall surfaces, said walls being of a thickness to support within the limits of elastic recovery high compressive external pressures applied about the periphery of said cylinder, and a metallic jacketing cylinder, said cylinders being separated and having formed therebetween shouldered fluid pressure sealing 10 of an enclosed space in the form of a tetrahedron said sides tapering longitudinally and inwardly toward the axis of said cylinder having the apex of said sides toward said axial bearing surface and an additional tapered punch disposed toward the opposite end of said cylinder having the tip end thereof forming a fourth side of said tetrahedron lying in a plane perpendicular to said cylinder axis closing the base of said tetrahedron, and press means acting simultaneously with tions to apply a compressive force upon said tetrahedral end portions and high pressure sealing means defining a fluid pressure containing jacket externally of said metallic cylinder, a plurality of circularly arranged tapered punches engaging said load bearing internal wall surfaces about the periphery of said walls and having central space enclosing tip portions, and means for applying fluid under pressure to said jacket thereby compressing said metallic cylinder to an extent within said limit of elastic recovery and moving said punches radially inwardly to apply a compressive force upon said enclosed space.

2. In a high pressure press, according to claim 1, the combination of supporting means on which said pressure applying cylinder is freely axially adjustable, a fixed pressure exerting element having an axially directed load bearing surface at one end of said cylinder, a movable pressure exerting element having an axially directed load bearing surface at the other end of said cylinder, axially movable tapered punches engaging said axially directed load bearing surfaces, pressure operated means acting simultaneously with said means for applying inwardly directed pressure against said cylinder to apply compressive pressure against said movable pressure exerting ele ment, and thereby to move said punches inwardly from both said radial and axial directions with a corresponding axial adjustment of said cylinder.

3. In a high pressure press, the combination of a pressure applying assembly for directing pressure against an enclosed space including a pressure applying metallic cylinder having load bearing internal wall surfaces, said walls being of a thickness to support within the limits of elastic recovery high compressive externalpressures applied about the periphery of said cylinder, and a metallic jacketing cylinder, said cylinders being separated and having formed therebetween shouldered fluid pressure sealing end portions and high pressure sealing means defining a fluid pressure containing jacket externally of said metallic cylinder, pressure supporting elements having axially directed load bearing surfaces at each end of said cylinder, three tapered punches fitted circularly within said cylinder in contact with said load bearing internal wall surfaces and in sliding contact with one of said axial load bearing surfaces, the inwardly disposed tip ends thereof defining three adjacent sides enclosed space.

4. In a high pressure press, the combination of load bearing surfaces arranged for directing pressure against an enclosed space including a pressure applying metallic cylinder having load bearing internal wall surfaces, said walls being of a thickness to support within the limits of elastic recovery high compressive external pressures applied about the periphery of said cylinder, and a metallic jacketing cylinder, said cylinders being separated and having formed therebetween shouldered fluid pressure end portions defining a fluid pressure containing jacket externally of said metallic cylinder, a relatively fixed axially directed load bearing surface at one end of said cylinder, and an axially movable load bearing surface at the other end of said cylinder, a plurality of tapered punches fitted within said cylinder in contact with said load bearing wall surface, and a tapered punch at each end of said cylinder in contact with said respective axially directed load bearing surface, the inwardly disposed tip ends of said punches defining said enclosed space, resilient means supporting said cylinder permitting adjustment of said cylinder longitudinally of its axis, and means for applying compressive fluid pressure against said punches including means for applying fluid under pressure to said jacket thereby compressing said steel cylinder around the periphery thereof to reduce the internal diameter of said cylinder, and means for applying pressure to move said movable axially directed load bearing surface, said cylinder and punches fitted therein moving axially to maintain a centered relation between said end punches.

5. In a high pressure press, the combination of load bearing surfaces arranged for directing pressure against a sample containing enclosed space including a pressure applying metallic cylinder having walls of substantial thickness, load bearing internal Wall surfaces the walls of said cylinder being of a thickness to support within the limits of elastic recovery high compressive external pressure applied about the periphery of said cylinder, a metallic jacketing cylinder, said cylinders being separated and having formed therebetween shouldered fluid pressure sealing end portions and high pressure sealing means defining a fluid pressure containing jacket externally of said metallic cylinder, additional pressure exerting elements having axially directed load bearing surfaces, said elements being relatively movable axially of said cylinder, a group of tapered punches fitted at equally spaced intervals about the inner periphery of said cylinder and slidably supported against one of said axially directed load bearing surfaces, a second group of punches fitted at equally spaced intervals against the inner periphery of said cylinder adjacent said first mentioned punches and slidably supported against the other of said axially directed load bearing surfaces, the inner ends of said punches having faces shaped to enclose said space, each said face being shaped to exert pressure both radially and axially inwardly of said space, and means for applying fluid under pressure to said jacket to produce compressive pressure against said cylinder around the periphery thereof and against said additional pressure exerting elements to apply a compressive force through said punches against a sample contained in said enclosed space.

6. In a high pressure press, the combination of a pressure applying assembly for directing pressure against an enclosed space including a pressure applying metallic cylinder having load bearing internal wall surfaces, said Walls being of a thickness to support Within the limits of elastic recovery high compressive external pressures applied about the peri hery of said cylinder, and a metallic jacketing cylinder, said cylinders being separated and having formed therebetween shouldered fluid pressure sealing end portions and high pressure sealing means defining a fluid pressure containing jacket externally of said metallic cylinder, pressure exerting elements at each end of said cylinder having opposed axially directed load bearing surfaces, a plurality of tapered punches supported Within said cylinder arranged so that the tip portions thereof define an enclosed space, a plurality of said punches being arranged circularly for engagement with the load bearing internal wall surfaces within said cylinder, and certain of said punches having engagement with said axially directed load bearing surfaces, means for applying fluid under pressure to said jacket thereby compressing said metallic cylinder within said limit of elastic recovery and moving the punches engaged thereby radially inwardly, and independent pressure applying means acting against at least one said axially directed load bearing surface to move said punches engaged there with axially inwardly.

7. In a high pressure press, the combination of a pressure applying assembly for directing pressure against an enclosed space including a pressure applying metallic cylinder having load bearing internal wall surfaces, said walls being of a thickness to support within the limits of elastic recovery high compressive external pressures applied about the periphery of said cylinder, and a metallic jacketing cylinder, said cylinders being separated and having formed therebetween saouldered fluid pressure sealing end portions and high pressure sealing means defining a fiuid pressure containing jacket externally of said metallic cylinder, pressure exerting elements at each end of said cylinder having opposed axially directed load bearing surfaces, a plurality of tapered punches supported within said cylinder arranged so that the tip portions thereof define an enclosed space, a plurality of said punches being arranged circularly for engagement with the load bearing internal wall surfaces within said cylinder, and certain of said punches having engagement with said axially directed load bearing surfaces, and means for applying iluid under pressure to said jacket thereby compressing said metallic cylinder within said limit of elastic recovery and moving the punches engaged thereby radially inwardly to apply a compressive force upon said enclosed space.

References Cited in the file of this patent UNITED STATES PATENTS 2,367,779 Hull Jan. 23, 1945 2,612,673 Billner Oct. 7, 1952 2,658,237 Cuppett et al Nov. 10, 1953 2,876,072 Coes Mar. 3, 1959 2,941,252 Bovenerly June 21, 1960 2,996,763 Wentorf Aug. 22, 1961 3,011,043 Zeitlin et al Nov. 28, 1961

Claims

4. IN A HIGH PRESSURE PRESS, THE COMBINATION OF LOAD BEARING SURFACES ARRANGED FOR DIRECTING PRESSURE AGAINST AN ENCLOSED SPACE INCLUDING A PRESSURE APPLYING METALLIC CYLINDER HAVING LOAD BEARING INTERNAL WALL SURFACES, SAID WALLS BEING OF A THICKNESS TO SUPPORT WITHIN THE LIMITS OF ELASTIC RECOVERY HIGH COMPRESSIVE EXTERNAL PRESSURES APPLIED ABOUT THE PERIPHERY OF SAID CYLINDER, AND A METALLIC JACKETING CYLINDER, SAID CYLINDERS BEING SEPARATED AND HAVING FORMED THEREBETWEEN SHOULDERED FLUID PRESSURE END PORTIONS DEFINING A FLUID PRESSURE CONTAINING JACKET EXTERNALLY OF SAID METALLIC CYLINDER, A RELATIVELY FIXED AXIALLY DIRECTED LOAD BEARING SURFACE AT ONE END OF SAID CYLINDER, AND AN AXIALLY MOVABLE LOAD BEARING SURFACE AT THE OTHER END OF SAID CYLINDER, A PLURALITY OF TAPERED PUNCHES FITTED WITHIN SAID CYLINDER IN CONTACT WITH SAID LOAD BEARING WALL SURFACE, AND A TAPERED PUNCH AT EACH END OF SAID CYLINDER IN CONTACT WITH SAID RESPECTIVE AXIALLY DIRECTED LOAD BEARING SURFACE, THE INWARDLY DISPOSED TIP ENDS OF