Method for manufacturing rupture disks

An improved method of manufacturing a rupture disk containing one or more scores or perforations from a sheet metal section comprising the steps of cutting the sheet metal section into a disk, forming a concave-convex dome in the disk by applying pressurized fluid to one side thereof, and then forming one or more scores or perforations in the concave-convex dome of the disk while continuing to apply pressurized fluid thereto. Automated apparatus for carrying out the method of the invention is also provided.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to a method and apparatus for 
manufacturing rupture disks, and more particularly, but not by way of 
limitation, to an improved method and apparatus for manufacturing rupture 
disks containing one or more scores or perforations from sheet metal 
sections. 
2. Description of the Prior Art 
Many fluid pressure relief devices of the rupturable type have been 
developed and used heretofore. Commonly, such rupturable pressure relief 
devices include a rupture disk supported between a pair of supporting 
members or flanges which are in turn connected to a relief connection in a 
vessel or system containing fluid pressure. When the fluid pressure within 
the vessel or system exceeds the design rupture pressure of the disk, 
rupture occurs causing excess fluid pressure to be relieved from the 
vessel or system. 
Various types of rupture disks and rupture disk assemblies have been 
developed and used which fall within three general categories, i.e., those 
that rupture in tension known as "conventional" rupture disks, those that 
reverse and then rupture known as "reverse buckling" rupture disks and 
composites of both the conventional and reverse buckling types. Composite 
rupture disk assemblies generally include one or more rupture disks 
combined with one or more perforated members such as vacuum supports, 
protection members, members which tear or rupture when a primary rupture 
disk ruptures, etc. While some rupture disks and composite assemblies are 
flat, most include an annular flat flange portion to facilitate clamping 
between supporting members or flanges connected to a concave-convex dome 
portion which ruptures when excess fluid pressure is exerted on the disk. 
In the operation of a reverse buckling rupture disk, the fluid pressure is 
exerted on the convex side of the dome portion of disk, and upon failure, 
the dome portion reverses and then ruptures. Fluid pressure is exerted on 
the concave side of conventional rupture disks and the disks rupture in 
tension. 
Metal rupture disks of both the reverse buckling type and conventional type 
have heretofore included one or more scores on a surface of the 
concave-convex portion which create lines of weakness so that upon rupture 
of the disk, the concave-convex portion tears along the lines of weakness 
and opens with little or no fragmentation of the metal. Various methods of 
manufacturing scored rupture disks have heretofore been developed. For 
example, a method of manufacturing reverse buckling scored disks is 
disclosed in U.S. Pat. No. 3,921,556 issued Nov. 25, 1975 and assigned to 
the assignee of the present invention. While such method as well as other 
methods have been used successfully for manufacturing scored reverse 
buckling rupture disks, because of deformation and stresses which are 
produced in the disks, a number of reforming and annealing steps have 
heretofore been required to produce rupture disks having desired 
operational characteristics. Generally, in all of the heretofore used 
methods of manufacturing scored or perforated rupture disks, the stresses 
and deformation produced when forming the scores or perforations have 
brought about less than optimum operational characteristics or require 
additional manufacturing steps. 
By the present invention an improved method and automated apparatus for 
carrying out the method are provided for manufacturing scored and 
perforated rupture disks of the conventional, reverse buckling and 
composite types wherein deformation and stresses in the disks due to the 
manufacturing process are reduced and all or part of the time-consuming 
and expensive reforming and annealing procedures previously required are 
eliminated. 
SUMMARY OF THE INVENTION 
By the present invention there is provided an improved method of 
manufacturing a rupture disk containing one or more scores or perforations 
from a sheet metal section comprising the steps of cutting the section 
into a disk, forming a concave-convex dome in the disk by applying 
pressurized fluid to one side thereof, and forming the one or more scores 
or perforations in the concave-convex dome of the disk while continuing to 
apply pressurized fluid thereto. Automated apparatus for carrying out the 
method is also provided. 
It is, therefore, an object of the present invention to provide an improved 
method and apparatus for manufacturing rupture disks containing one or 
more scores or perforations from sheet metal sections. 
A further object of the present invention is the provision of a method and 
apparatus for manufacturing scored rupture disks, both of the conventional 
and reverse buckling types, wherein fewer stresses and less deformation of 
the metal results as a consequence of the manufacturing process. 
Another object of the present invention is the provision of a method and 
apparatus for manufacturing reverse buckling scored rupture disks wherein 
all or at least a part of the reforming and annealing steps heretofore 
required for producing such disks with required operational 
characteristics are eliminated. 
Yet another object of the present invention is the provision of automated 
apparatus for manufacturing rupture disks containing one or more scores or 
perforations. 
Other and further objects, features and advantages of the present invention 
will be readily apparent to those skilled in the art upon a reading of the 
description of preferred embodiments which follows when taken in 
conjunction with the accompanying drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring now to the drawings, and particularly to FIGS. 1-6, the automated 
apparatus of the present invention for manufacturing rupture disks 
containing one or more scores or perforations from sheet metal sections is 
illustrated and generally designated by the numeral 10. The apparatus 10 
is formed of metal and includes a rectangular base 12 having a pair of 
rectangular vertical side supports 14 and 16 attached to opposite end 
portions thereof. A circular opening 18 is centrally positioned in the 
base 12 and a cylindrical pedestal 20 is attached to the base 12 over the 
opening 18. Positioned on opposite sides of the pedestal 20 and attached 
to the base 12 are conventional hydraulic cylinders 22 and 24 having 
vertically extending lever arms 26 and 28, respectively. 
The lever arms 26 and 28 of the hydraulic cylinders 22 and 24 are rigidly 
attached to a rectangular platform 30. The platform 30 is of a size 
corresponding with the base 12 and the opposite end portions 32 and 34 of 
the platform 30 extend over the upper ends of the supports 14 and 16. 
Three spaced apart vertical guide pins 36 are attached to the end portion 
32 of the platform 30 which slidably extend into complementary bores 38 
disposed in the support 14. In a like manner, three vertical guide pins 40 
are attached to the end portion 34 of the platform 30 which slidably 
extend into complementary bores 42 disposed in the support 16. 
The platform 30 includes a circular opening 44 (FIG. 1) disposed therein, 
and attached to the lower side of the platform 30 around the opening 44 is 
a clamping and cutting assembly generally designated by the numeral 46. As 
best shown in FIGS. 1, 4 and 5, the assembly 46 is comprised of a fixed 
cylindrical cutting member 48 which is rigidly attached to the platform 30 
by a plurality of cap screws 50. The cutting member 48 includes an 
inwardly extending flange portion at the bottom thereof forming an 
upwardly facing annular shoulder 52 interiorly thereof. 
Slidably disposed within the cutting member 48 is a cylindrical clamping 
member 54 which includes an upper outwardly extending flange portion which 
forms a downwardly facing annular shoulder 56. The clamping member 54 is 
of a vertical size such that it is free to slide vertically within the 
cutting member 48 between a lowermost position whereby the annular 
shoulder 56 thereof abuts the annular shoulder 52 of the cutting member 48 
and an uppermost position whereby the upper annular end 58 of the clamping 
member 54 abuts the lower side of the platform 30. The lower annular end 
60 of the clamping member 54 includes at least two and preferably three 
downwardly extending locating hole punches 62 spaced in predetermined 
relationship thereon. 
As shown in FIGS. 1 and 4, the upper annular end 58 of the clamping member 
54 includes an annular recess 64 formed therein within which a 
conventional O-ring 66 is disposed. In addition, a plurality of springs 68 
are positioned in complementary opposing recesses formed in the ends 58 of 
the clamping member 54 and the platform 30. The springs 68 urge the 
clamping member 54 to its lowermost position with respect to the cutting 
member 48 as illustrated in FIG. 1. 
Removably positioned on top of the cylindrical pedestal 20 is a cylindrical 
rupture disk forming die 70. As shown in FIGS. 1, 2 and 3, the cylindrical 
die 70 is removably held in alignment with the clamping and cutting 
assembly 46 on the pedestal 20 by a pair of clips 72 and a pair of 
alignment pins 74. The alignment pins 74 are attached to the bottom face 
of the die 70 and extend into complementary bores disposed in the pedestal 
20. The clips 72 include tongue portions 76 which extend into 
complementary grooves in the die 70 and the clips 72 are held to the 
pedestal 20 by bolts 78. 
The upper face of the die 70 has a forming configuration comprised of an 
outer annular flat portion 80 (FIGS. 1 and 3) surrounding an inner 
dish-shaped recess 82. Disposed in the annular flat portion 80 of the die 
70 are three openings 84 of complementary position and size with the 
locating hole punches 62 of the clamping member 54. The openings 84 
communicate with enlarged passageways 86 which extend from the openings 84 
downwardly through the die 70 to the bottom face thereof where they 
communicate with the central opening in the cylindrical pedestal 20 which 
in turn communicates with the opening 18 in the base 12. Another passage 
88 is disposed vertically through the die 70 from the recess 82 to the 
bottom face thereof whereby the recess is communicated with the opening in 
the cylindrical pedestal 20. 
Attached to the top of the platform 30 are a pair of spaced apart 
vertically positioned rectangular support members 90 and 92. The top ends 
of the support members 90 and 92 are in turn attached to a horizontally 
positioned rectangular support member 94. A hydraulic cylinder 96 is 
attached to the bottom side of the member 94 whereby the lever arm 98 of 
the cylinder 96 extends vertically downwardly. Attached to the arm 98 is a 
horizontally positioned rectangular striker plate 100 (FIGS. 1 and 6) and 
attached to the bottom side of the plate 100 is a vertically positioned 
elongated cylindrical ram 102 (FIGS. 1 and 4) which slidably extends 
through the circular opening 44 in the platform 30. 
An annular seal unit 104 is bolted to the top surface of the platform 30 
around the opening 44 therein by a plurality of bolts 106. The seal unit 
104 includes an annular recess 108 positioned adjacent the outside surface 
of the cylindrical ram 102 and a conventional O-ring 110 is disposed in 
the recess 108. 
As shown in FIGS. 1 and 5, attached to the downwardly facing circular end 
of the ram 102 by a plurality of cap screws 112 is a score forming blade 
assembly 114 which includes a circular base member 116 to which a blade 
member 118 of cross configuration is attached. The base member 116 
includes a vertical passage 120 extending therethrough which aligns and 
communicates with a vertical passage 122 in the cylindrical ram 102. The 
vertical passage 122 intersects and communicates with a horizontal passage 
124 which extends through a side of the ram 102 and is threaded for 
receiving a conventional fitting to which a hose is attached (not shown). 
Referring now specifically to FIGS. 1, 6, 7 and 8, a pair of microbar 
assemblies 130 and 132 are attached to the platform 30 on opposite sides 
of the ram 102 and are positioned parallel to each other and to the ends 
of the striker plate 100. The microbar assemblies 130 and 132 function in 
combination with the striker plate 100 to limit the downward movement of 
the ram 102 and blade assembly 114 attached thereto. 
The microbar assemblies 130 and 132 are identical and the following 
description of the assembly 132 applies equally to the assembly 130. As 
best shown in FIGS. 7 and 8, the microbar assembly 132 is comprised of a 
base member 134 which includes an upwardly facing rectangular recess 136 
extending over its entire length. The bottom surface 138 of the recess 136 
is inclined with respect to the member 134 and an elongated substantially 
rectangular bearing member 140 is disposed in the recess 136 of the base 
member 134. The bottom surface 142 of the member 140 which is in contact 
with the bottom surface 138 of the recess 136 is inclined similarly to the 
surface 138 whereby the top 144 of the member 140 remains parallel to the 
bottom of the base member 134 when the member 140 is moved laterally with 
respect to the base member 134. However, as will be understood, when the 
member 140 is moved to the right with respect to the base member 134, the 
distance between the top surface 144 thereof and the bottom of the base 
member 134 increases. Conversely, when the member 140 is moved to the left 
with respect to the base member 134, the distance between the surface 144 
thereof and the bottom of the base member 134 is decreased. 
Semicircular laterally extending grooves 146 and 148 are disposed in the 
adjacent surfaces 138 and 142 of the base member 134 and bearing member 
140, respectively, and the groove 148 includes threads while the groove 
146 does not. A threaded shaft 150 is disposed within the semicircular 
grooves 146 and 148, the threads of which engage the threads of the groove 
148, and a knob 152 for rotating the shaft 150 is attached to one end 
thereof. The shaft 150 is prevented from moving with respect to the base 
member 134 by a flange portion 154 at one end thereof and a continuous 
annular recess 156 at the other end thereof into which a protuberance 158 
in the semicircular groove 146 of the member 134 extends. As will now be 
apparent, when the shaft 150 is rotated by rotating the knob 152, the 
member 140 is moved laterally either increasing or decreasing the overall 
height of the assembly 132. 
Referring now to FIG. 9, the apparatus 10 is schematically illustrated in 
conjunction with the hydraulic fluid conduits, valves, controls and pump 
for operating the hydraulic cylinders 22, 24 and 96 and with the conduits 
and valves for causing pressurized fluid to flow through and be exhausted 
from the passages 122 and 124 of the ram 102 and the passage 120 of the 
blade assembly 114. More specifically, the upper hydraulic fluid ports of 
the hydraulic cylinders 22 and 24 are communicated with a header 170 by 
conduits or hoses 172 and 174, respectively. The lower ports of the 
cylinders 22 and 24 are communicated with a header 176 by conduits or 
hoses 178 and 180, respectively. The headers 170 and 176 are communicated 
with the ports of a conventional solenoid operated hydraulic control valve 
182 by conduits 184 and 186, respectively. 
The upper port of the hydraulic cylinder 96 is connected by a conduit or 
hose 188 to a port of a conventional solenoid operated hydraulic fluid 
control valve 192. The lower port of the cylinder 96 is connected to 
another port of the control valve 192 by a conduit 194. 
A conventional hydraulic fluid pump 196 is provided the inlet connection of 
which is connected by a conduit 198 to a hydraulic fluid accumulator and 
return system (not shown, but designated by the symbol .hoarfrost.). The 
discharge of the pump 196 is connected by a conduit 200 to a conventional 
hydraulic fluid pressure regulator 202, and a conduit 204 leads hydraulic 
fluid from the pressure regulator 202 to the hydraulic fluid inlet port of 
the valve 182. A conduit 206 connected to the conduit 204 leads hydraulic 
fluid to the inlet port of the valve 192. 
A conduit 208 connects a port of the valve 182 to the hydraulic fluid 
return system and a conduit 210 connects a port of the valve 192 to the 
return system. A conduit 212 is connected to the conduit 200 and to the 
return system, and a solenoid operated valve 214 is disposed in the 
conduit 212. Conventional hydraulic fluid pressure switches 216, 217 and 
218 are connected to the conduits 206, 174 and 188, respectively. 
A conduit 200 leads pressurized fluid, such as pressurized air, from a 
source thereof to a solenoid operated valve 202. A conduit or hose 204 
leads the pressurized fluid from the valve 202 to the opening 126 in the 
ram 102 which is communicated with the passages 122, 124 and 120 
previously described. A conduit or hose 206 is connected to the conduit or 
hose 204 and to a solenoid operated shutoff valve 208. The valve 208 is in 
turn connected by a conduit 210 to a flow restrictive orifice assembly 
212. The assembly 212 is in turn communicated to the atmosphere or a vent 
by a conduit 214. 
OPERATION OF THE APATUS 10 
As will be understood by those skilled in the art, the operation of the 
apparatus 10 is controlled by a conventional electric control system which 
can in turn be operated manually or operated by a computer, etc. The 
electric control system operates the solenoids of the hydraulic control 
valves and the other valves described herein which in turn control the 
operation of the hydraulic cylinders 22, 24 and 96 and the application of 
pressurized fluid or the exhausting thereof. More specifically, the 
apparatus 10 is ready to commence the manufacture of a scored or 
perforated rupture disk from a sheet metal section as it is shown in FIGS. 
1 and 9. More specifically, referring to FIG. 9 hydraulic fluid is pumped 
from the hydraulic fluid return and accumulator system by the pump 196 
through the conduit 198 and into the conduit 200. The conduit 200 leads 
the hydraulic fluid to the pressure regulator 202 which controls the 
hydraulic fluid pressure at a predetermined level. From the pressure 
regular 202, hydraulic fluid flows by way of the conduit 204 to the 
control valve 182 which routes the hydraulic fluid by way of the conduit 
186 through the header 176 and the conduits 178 and 180 into the lower 
ports of the cylinders 22 and 24 which causes the platform 30 and the 
apparatus attached thereto to be moved upwardly away from the die 70. The 
upper ports of the cylinders are communicated by the conduits 172 and 174, 
the header 170 and the conduit 184 to the hydraulic fluid return system by 
way of the valve 182 and the conduit 208. 
In a like manner, hydraulic fluid flowing to the control valve 192 by way 
of the conduit 206 connected thereto is routed to the lower port of the 
hydraulic cylinder 96 by way of the conduit 194 and hydraulic fluid is 
exhausted from the upper port thereof by way of the conduit 188, the valve 
192 and the conduit 210 to the return system which causes the plate 100 
and ram 102 to be moved upwardly by the hydraulic cylinder 96. 
The manufacturing process is begun by placing a substantially square sheet 
metal section 300 (FIGS. 1 and 3) on the rupture disk forming die 70, 
i.e., on the upwardly facing forming face of the die 70. As will be 
understood, the sheet metal section 300 is generally cut from a larger 
sheet, it is flat and it can be formed of any of a variety of metals 
depending upon the particular application in which the rupture disk 
manufactured therefrom is to be used. Generally, the particular metal used 
and the thickness thereof are predetermined by prior experience or by 
trial and error. 
After placing the sheet metal section 300 on the rupture disk forming face 
of the die 70, the hydraulic fluid control valve 182 is reversed whereby 
hydraulic fluid flows from the valve 182 through the conduit 184, through 
the header 170 and through the conduits 172 and 174 into the hydraulic 
cylinders 22 and 24 by way of the upper ports thereof. This in turn causes 
the pistons within the hydraulic cylinders to move downwardly and 
hydraulic fluid to flow from the cylinders 22 and 24 by way of the lower 
ports therein, the conduits 178 and 180, the header 176 and the conduit 
186 to the valve 182 and into the hydraulic fluid return system by way of 
the conduit 208. 
The downward movement of the pistons within the hydraulic cylinders 22 and 
24 moves the lever arms 26 and 28 thereof and the platform 30 attached 
thereto downwardly. The platform 30 is maintained in proper alignment by 
the guide posts 36 and 40 which move downwardly within the bores 38 and 42 
in the support members 14 and 16. As the platform 30 moves downwardly, the 
clamping and cutting assembly 46 moves towards the die 70 and the sheet 
metal section 300 positioned thereon. The three punches 62 (FIG. 1) 
extending from the annular face 60 of the clamping member 54 first come 
into contact with the sheet metal section 300 as the assembly 46 moves 
downwardly and the punches 62 punch locating holes in the section 300. The 
circular metal parts punched from the section 300 when the locating holes 
are formed therein drop through the passages 86 in the die 70 and through 
the interior of the pedestal 20 and the opening 18 in the base 12. As the 
platform 30 and the assembly 46 continue to move downwardly, the annular 
clamping face 60 of the clamping member 54 contacts the sheet metal 
section 300 and rigidly clamps it against the annular flat portion 80 of 
the forming face of the die 70. The continued downward movement of the 
platform 30 causes the springs 68 between the clamping member 54 and 
platform 30 to be compressed and the cutting member 48 to continue its 
movement towards the die 70. The external diameter of the cylindrical die 
70 is slightly less than the internal diameter of the cylindrical cutting 
member 48 so that when the bottom face of the cutting member 48 contacts 
the portions of the sheet metal section 300 overlapping the periphery of 
the forming face of the die 70, the continued downward movement of the 
cutting member 48 causes the overlapping portions of the section to be 
sheared therefrom. When the hydraulic cylinders 22 and 24 have moved the 
platform 30 to its lowermost position, the clamping face 60 of the 
clamping member 54 is positioned against the section 300 which is in turn 
clamped against the flat annular portion 80 of the forming face of the die 
70. In addition, the lower portion of the cutting member 48 overlaps an 
upper portion of the die 70, all as shown in FIG. 10. 
The hydraulic fluid pressure switch 217 (FIG. 9) attached to the conduit 
174 senses the pressure of the hydraulic fluid exerted within the 
cylinders 22 and 24, and when such pressure reaches a predetermined level 
thereby indicating that the section 300 is rigidly clamped between the 
clamping member 54 of the assembly 46 and the die 70 and that the cutting 
member 48 has been moved downwardly whereby the section has been cut into 
a disk, the pressure switch 217 closes or otherwise sends an electric 
signal to the electric control system whereby the second phase of the 
manufacturing operation is commenced. 
The second phase of the manufacturing operation involves forming a 
concave-convex dome in the section 300 which has previously been cut into 
a disk. This is accomplished by the opening of the valve 202 (FIG. 9) 
whereby pressurized fluid, preferably pressurized air, is caused to flow 
from a source thereof by way of the conduit 200, through the valve 202 and 
the conduit 204, through the passages 122 and 124 in the ram 102 and 
through the passage 120 in the plate 116 of the blade assembly 114. 
Referring now to FIG. 11, the O-ring 66 provides a seal between the top 
face of the clamping member 54 and the bottom surface of the platform 30 
and the O-ring 110 provides a seal between the member 104 and the outside 
surface of the ram 102. Thus, the space between the top surface of the 
sheet metal disk 300 and the plate 116 of the blade assembly 114 is sealed 
and the pressurized fluid flowing into the space by way of the passage 120 
creates a force on the top side of the disk 300. The pressurized fluid 
forces the disk 300 downwardly against the surface of the dish-shaped 
recess 82 in the forming face of the die 70 as shown in FIG. 11. The 
passage 88 in the die 70 allows air trapped between the bottom surface of 
the sheet metal disk 300 and the surface of the recess 82 to escape as the 
disk is forced against and conformed to the forming face of the die 70 
whereby a concave-convex dome is formed therein. 
Referring again to FIG. 9, after the pressurized fluid has been applied to 
the sheet metal disk 300 for a predetermined period of time, the valve 202 
is shut off and the valve 208 is opened whereby pressurized fluid within 
the space between the blade assembly 114 and sheet metal disk 300 is 
exhausted by way of the passages 120, 122 and 124, the conduit 204, the 
conduit 206, the valve 208, the conduit 210, the orifice assembly 212 and 
the conduit 214. However, because the orifice 212 restricts the flow of 
pressurized fluid therethrough, the fluid pressure exerted on the sheet 
metal disk 300 within the apparatus 10 is exhausted therefrom slowly. 
While fluid pressure is being applied to the disk 300, the hydraulic 
control valve 192 is activated whereby hydraulic fluid flows by way of the 
conduit 206 to the valve 192 and through the conduit 188 into the top port 
of the hydraulic cylinder 96. This causes the piston within the cylinder 
96 to move downwardly which in turn causes hydraulic fluid to flow through 
the lower port of the cylinder, through the conduit 194, through the valve 
192 and into the hydraulic fluid return system by way of the conduit 210. 
As the lever arm 98 of the cylinder 96 moves downwardly, the plate 100 and 
ram 102 attached thereto also moved downwardly whereby the blade assembly 
114 attached to the ram 102 forceably contacts and forms scores in the 
concave-convex dome portion of the disk 300 as shown in FIG. 11. 
Prior to forming the disk 300, the microbar assemblies 130 and 132 are each 
adjusted in height so that the desired depth of score is formed in the 
disk 300 and the blade assembly 114 is prevented from being damaged. That 
is, the bottom surface of the plate 100 contacts the microbar assemblies 
130 and 132 immediately after the blade assembly 114 contacts the disk 300 
whereby scores of desired depth are formed on the disk 300 and the blade 
assembly is prevented from moving downwardly too far whereby it forceably 
contacts the die 70 and damages the die 70 or the blades 118. When the 
apparatus 10 is utilized to form rupture disks with perforations therein, 
i.e., the blade assembly attached to the ram 102 perforates the disk, the 
microbar assemblies 130 and 132 are set such that the blades of the blade 
assembly perforate the disk but do not contact the forming face of the die 
70 in a manner whereby damage to the die or the blade assembly results. As 
previously described, the height of the microbar assemblies 130 and 132 is 
adjusted by rotating the knobs 152 and shafts 150 (FIGS. 7 and 8) whereby 
the members 140 are moved laterally with respect to the base members 132 
thereof. 
After the scores have been formed in the disk 300, the blade assembly 114 
is maintained in forceable contact with the concave-convex dome portion of 
the disk 300 for a period of time, i.e., for a predetermined "dwell time". 
The pressure switch 218 (FIG. 9) attached to the conduit 188 senses the 
hydraulic fluid pressure in the top portion of the cylinder 96, and when 
the pressure reaches a predetermined level the hydraulic fluid flow into 
the cylinder is stopped to thereby control the maximum score blade force 
exerted on the disk 300. 
The hydraulic control valves 182 and 192 are next activated whereby the 
flow of hydraulic fluid to the cylinders 22, 24 and 96 is reversed and the 
platform 30 as well as the ram 102 and plate 100 are moved upwardly to 
their uppermost positions. The rupture disk 300 formed by the apparatus 10 
having the shape and form illustrated in FIGS. 12 and 13 is removed from 
the apparatus 10 and replaced with a new flat sheet metal section 
whereupon the manufacturing process is repeated to form another rupture 
disk, etc. 
Referring once again to FIG. 9, the pressure switch 216 senses the 
hydraulic fluid pressure in the system downstream of the pressure 
regulator 202. If the pressure becomes too high for any reason, i.e., 
above a predetermined set point, the switch 216 closes and causes the 
valve 214 to open whereby pressure is relieved from the system. Other 
safety controls which will suggest themselves to those skilled in the art 
can also be used in the apparatus 10. 
As shown in FIGS. 12 and 13, the rupture disk 300 produced includes an 
annular flat flange portion 301 connected to a concave-convex dome portion 
303 by an annular transition connection 305. The annular flat flange 
portion 301 includes three locating holes 302 for receiving locating pins 
which are positioned in a predetermined pattern whereby the disk 300 
cannot be installed upside down and the concave-convex portion 303 
includes four scores 304 positioned in a cross pattern whereby the scores 
extend radially outwardly from a central portion to the periphery of the 
dome portion. 
As will be understood, both the rupture disk forming die 70 and the score 
forming blade assembly 114 can be removed from the apparatus 10 and 
replaced with other rupture disk forming dies and score or perforation 
forming blades to produce rupture disks of different configurations 
containing different score or perforation patterns. For example, as shown 
in FIG. 14, a rupture disk 400 having the same configuration as the 
rupture disk 300 can be produced except that instead of a cross score 
pattern formed by four straight line scores, the rupture disk 400 includes 
a single score 402 forming a partial circle in the concave-convex dome 
portion thereof. 
A rupture disk 500 having yet another score pattern formed in the 
concave-convex dome portion thereof is illustrated in FIG. 15. That is, 
the rupture disk 500 contains three scores 502 which form a pattern 
comprised of two opposing arcs of a circle connected at intermediate 
points by a straight line score. 
FIG. 16 illustrates a perforated rupturable member 600 which can be formed 
by the apparatus 10 having a concave-convex dome portion which includes 
perforations 602 formed therein, i.e., triangular cut-outs whereby 
crossing straps 604 remain. 
FIG. 17 illustrates an alternate form of perforated rupturable member 
wherein the perforations form a plurality of apertures 702 connected by 
slits 704 extending radially outwardly from a central portion of the 
concave-convex dome portion of the disk to the periphery thereof. 
FIG. 18 illustrates yet another form of perforated rupturable member 800 
wherein the perforations are in the form of four slits 802 extending 
radially outwardly from a central portion of the disk. 
A variety of other rupture disks, rupturable members, vacuum supports and 
other disk products can be produced in accordance with the method of the 
present invention utilizing the apparatus 10. 
In forming all of the variety of disk products which can be formed with the 
apparatus 10, a concave-convex dome is first formed in a sheet metal disk 
by applying pressurized fluid to one side thereof followed by forming the 
scores or perforations in the concave-convex dome of the disk while 
continuing to apply pressurized fluid thereto. This is accomplished in the 
apparatus 10 by forceably contacting the concave-convex dome of the disk 
300 with the blade assembly 114 (FIG. 11) prior to or immediately upon the 
opening of the valve 208 which exhausts the pressurized fluid from the 
apparatus 10. Because of the orifice assembly 212 or other equivalent flow 
restriction means in the pressurized fluid exhaust flow path, pressurized 
fluid remains in the apparatus 10 after the scores or perforations are 
formed on the rupture disk being produced. This in turn reduces the 
stresses produced in the disk by the scoring or perforating. In addition, 
after the blade assembly attached to the ram 102 is brought into forceable 
contact with the rupture disk being produced to form the scores or 
perforations therein, the blade is preferably maintained in forceable 
contact with the disk for a predetermined dwell time. This again reduces 
the stresses formed in the disk and allows the metal of the disk to become 
well settled in its new shape before the various forces exerted on it are 
removed. 
Because the scores or perforations formed in the disk are formed while 
fluid pressure is maintained on the disk and because the score or 
perforation forming blade is maintained in forceable contact with the disk 
for a dwell time, the rupture disks produced by the method of this 
invention in the apparatus 10 have fewer stresses therein and generally do 
not require annealing to relieve stresses. This reduction or elimination 
of the requirement for annealing reduces the manufacturing cost of the 
rupture disks produced and allows rupture disks to be produced which are 
formed of metals which could not heretofore be utilized because they could 
not be annealed. Examples of such metals are silver, tantalum, titanium 
and platinum. 
The blade assembly of the apparatus 10 forms all of the scores or 
perforations produced in the rupture disks being manufactured at one time, 
which makes the scores or perforations more uniform in depth, width and 
other characteristics and the scores or perforations are more precise in 
configuration and orientation than those formed using prior manufacturing 
methods, all of which brings about a superior rupture disk product. In 
addition, because of the use of the microbar assemblies 130 and 132 in 
combination with the rest of the apparatus 10, more precise control of 
variables can be accomplished which in turn brings about the manufacture 
of rupture disks having better operational characteristics than heretofore 
possible. 
Thus, the method and apparatus of the present invention are well adapted to 
carry out the objects and attain the ends and advantages mentioned as well 
as those inherent therein. While presently preferred embodiments of the 
invention have been described for purposes of this disclosure, numerous 
changes can be made in the construction and arrangement of parts, which 
changes are encompassed within the spirit of this invention as defined by 
the appended claims.