Apparatus For Electrohydraulically Forming Tubular Elements

Abstract

This invention relates to a novel apparatus for forming or reforming tubular elements by positioning a tubular element internally of a split mold and generating an electrical discharge in a chamber internally of each tubular element whereby a shock wave is created to radially outwardly expand the chamber and force the tubular element into conformity with the split mold cavity.

Parent Case Text

This is a continuation application of application Ser. No. 749,885, filed Aug. 2, 1968, entitled APPARATUS FOR ELECTROHYDRAULICALLY FORMING TUBULAR ELEMENTS, now abandoned.

Description

A primary object of this invention is to provide a novel apparatus for "stylizing" one-piece metallic can bodies or similar tubular elements by hydraulic and electrohydraulic forces. The term "stylizing" is intended to mean the reforming of a tubular can body to a desired configuration, and more specifically to not only changing the over-all contour of the can body but to impress, emboss or otherwise transfer minute details to an exterior surface of the can body. For example, from the standpoint of consumer acceptance it might be found desirable to manufacture can bodies in which beer is to be packaged to a "beer barrel" configuration such that upper and lower end portions are of a smaller diameter than a central body portion, and the latter is preferably provided with circumferential grooves disposed in axially spaced relationship. This imparts to the can body the appearance of a "miniature" beer barrel.

In accordance with the invention one-piece can bodies are sequentially delivered by a lifter platen to a position beneath a pair of mold bodies of a split mold in axial aligned relationship to a support carrying a flexible chamber. The can body is elevated and a peripheral flange thereof is clamped between a portion of the chamber support and portions of the mold body upon the closing of the split mold. Liquid under pressure is then delivered to the chamber which causes the progressive expansion thereof which in turn forces the can body into general conformity with a mold cavity of the split mold. At this point the pressure is not sufficiently high to transfer minute details from the mold cavity to the exterior surface of the can body. Thereafter an electrical discharge is created in the chamber while still under pressure to create a high energy shock wave to terminate the stylizing operation by forcing the exterior surface of the can body into intimate contact with the mold cavity upon the momentary high-force expansion of the chamber. Thereafter the pressure is relieved, the chamber is purged, the split mold is opened, and the lifter platen is lowered to remove the stylized can body incident to the discharge thereof from the apparatus.

In addition to the broader aspects of the invention heretofore described, it is also a primary object of the invention to clamp each can body in the split mold in such a manner as to produce stylized can bodies of substantially uniform repetitive heights, and to provide novel means for increasing the clamping forces in proportion to the increase of pressure in the chamber.

Still another object of this invention is to provide a novel apparatus for stylizing can bodies in the manner heretofore set forth wherein novel linkage means are provided for closing the split molds in such a manner which preloads the links of the linkage mechanism to thereby effectively clamp closed the split molds and resist the high forming forces, particularly the electrohydraulic force which approximates 30,000 p.s.i.

Still another object of the invention is to provide novel means for pressurizing the fluid chamber in the form of an intensifier which is so arranged in a hydraulic system that noncorrosive hydraulic fluid is used to pressurize the corrosive medium (saline solution) within the chamber to thereby reduce the high cost which would otherwise be involved in employing noncorrosive stainless steel or other material in a hydraulic system containing only corrosive fluid.

A final object of this invention is to provide a novel apparatus of the type heretofore set forth wherein a plurality of split molds and expansible chambers are carried by a turret, each of the chambers includes a pair of electrodes, and both the power supply and a storage capacitor (or inductor) are located externally of the turret thereby eliminating the necessity of high voltage rotary electrical and hydraulic connections as well as eliminating the need for a splash-proof ignitron which would otherwise be required if the storage capacitor were carried by the turret.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter, and the several views illustrated in the accompanying drawings.

IN THE DRAWINGS

FIG. 1 is a highly schematic top plan view of the apparatus of this invention, and illustrates the various operations which are performed and the areas at which they are performed between the time a can body is fed to a turret of the apparatus and thereafter discharged therefrom in its stylized form.

FIG. 2 is a schematic view of one of a plurality of split molds and expansible chambers carried by the turret, and illustrates the manner in which a can body on a lifter platen is raised upwardly into external telescopic relationship to the expansible chamber and internal telescopic relationship to a mold cavity.

FIG. 2A is a schematic view similar to FIG. 2, and illustrates the can body in its uppermost position as a pair of split mold bodies begin to close.

FIG. 2B illustrates the mold of FIG. 2A in its completely closed and locked position with a peripheral flange of the container body clamped between a support of the expansible chamber and portions of the mold bodies.

FIG. 2C is a schematic view with a portion of the expansible chamber broken away for clarity, and illustrates the chamber being radially expanded under the influence of hydraulic pressure to conform the can body to the general contour of the mold cavity.

FIG. 2D is a schematic view of the can body after it has been stylized by the discharge of electrical energy across a pair of electrodes to transfer intimate cavity designs to the exterior of the now stylized can body.

FIG. 2E is a schematic view illustrating the open position of the mold and the now purged chamber, and illustrates the stylized can being removed by downward movement of the bottom die body or lifter platen.

FIG. 3 is a timing diagram, and indicates the relationship between turret rotation and the relationship of a can body to the operations being performed relative thereto.

FIG. 4 is a schematic illustration of the hydraulic system of the apparatus, and illustrates a fluid isolator or intensifier for pressurizing the expansible chambers.

FIG. 5 is a fragmentary top plan view of the apparatus with certain structure removed for clarity, and illustrates means for feeding can bodies to the apparatus, the manner in which four split molds carried by a turret are opened and closed, and means for discharging stylized can bodies from the turret.

FIG. 6 is a fragmentary axial sectional view taken through the apparatus with certain portions removed for clarity, and illustrates the mounting of the turret, and cam and cam follower means for lifting a can body carried by a bottom die body into external telescopic relationship to one of the expansible chambers prior to closing the split mold associated therewith.

FIG. 7 is a fragmentary side elevational view, partially in section, taken generally along line 7--7 of FIG. 8, and illustrates a linkage mechanism associated with each split mold for opening and closing the same through the operation of a cam and cam follower mechanism.

FIG. 8 is a fragmentary sectional view taken generally along line 8--8 of FIG. 7 and more clearly illustrates the four split molds and the linkage mechanisms associated therewith.

FIG. 9 is a fragmentary sectional view taken generally along line 9--9 of FIG. 8 when the split mold is at a feed station, and illustrates the manner in which a can body is transferred from a star wheel to a position in alignment with the open split molds by a cam and cam follower mechanism.

FIG. 10 is an enlarged fragmentary sectional view taken generally along line 10--10 of FIG. 9, and illustrates a plurality of passages for connecting a vacuum source to the under side of a can body carried by the bottom die body for holding the can body thereon.

FIG. 11 is a sectional view taken generally along line 11--11 of FIG. 10, and illustrates one of a plurality of compression springs associated with the lower die body or platen.

FIG. 12 is a fragmentary sectional view of another platen, and illustrates the convex configuration of a chamber when employed in conjunction with a bottom seamed or seamless can body.

FIG. 13 is a cross sectional view taken generally along line 13--13 of FIG. 6, and illustrates four vacuum lines each of which is associated with one of the platens.

FIG. 14 is a fragmentary cross-sectional view similar to FIG. 9 but taken at a position at which the can body has been lifted by the platen to its uppermost position, and illustrates a cam follower for supporting the platen during the forming operation.

FIG. 15 is a perspective view of one of the split mold bodies, and illustrates the particular configuration of a cavity formed therein.

FIG. 16 is a fragmentary perspective view of one of the split molds, and illustrates the manner in which a cam and cam follower associated with a linkage mechanism closes the split mold.

FIG. 17 is a fragmentary sectional view taken through the split mold and linkage mechanism of FIG. 16, and illustrates the manner in which the cam follower is moved upwardly to close the split mold.

FIG. 18 is an axial sectional view taken through one of four identical transducers of the apparatus, and illustrates an interior rigid cage structure surrounded by an expansible bag-like element which defines the expansible chamber, and additionally illustrates the container body in external telescopic relationship thereto.

FIG. 19 is a cross-sectional view taken generally along line 19--19 of FIG. 18, and illustrates the manner in which one of a pair of electrodes is connected to a conductor.

FIG. 20 is a sectional view taken generally along line 20--20 of FIG. 18, and illustrates the manner in which the other of the electrodes is connected to a conductor and passage means for introducing and removing liquid from the chamber.

FIG. 21 is a cross-sectional view taken generally along line 21--21 of FIG. 18, and more clearly illustrates the internal cage structure of the transducer and particularly a plurality of circumferentially spaced electrode-supporting pillars.

FIG. 22 is a fragmentary cross-sectional view taken through a stationary central supporting column of the turret, and illustrates a pair of rotary valves forming a portion of the hydraulic system of FIG. 4 for pressurizing and purging the transducer chambers.

FIG. 23 is a cross-sectional view taken generally along line 23--23 of FIG. 22, and more clearly illustrates the manner in which the valves are coupled to each of the four transducers and to drain.

FIG. 24 is a fragmentary cross-sectional view of one of the transducers, and illustrates alignment between stator and rotor contacts for creating an electrical discharge across the electrodes.

FIG. 25 is a sectional view taken long line 25--25 of FIG. 24, and more clearly illustrates the relative position between the stator and rotor contacts at the time of discharge.

GENERAL DESCRIPTION

The can body stylizing apparatus of this invention is generally designated by the reference numeral 10 and includes a rotatable turret 12 which carries four identical split molds 13 (FIG. 2), a transducer 14, and a bottom mold body or platen 15. Referring in particular to FIGS. 1 through 2D, a can body C is delivered to an infeed star wheel 16 which transfers the can body C in overlying relationship to the platen 15 which is moved counterclockwise, as viewed in FIG. 1. A vacuum holds the can body C upon the platen 15 as the platen 15 rises upwardly to position the can body C in external telescopic relationship to an expansible chamber 17 of the transducer 14. As the platen 15 is elevated mold bodies 18, 20 defining therebetween a mold cavity 21 begin to close (FIG. 2A), fully close, and clamp a peripheral flange F between a portion of the transducer 14 and portions of the split molds 18, 20 (FIG. 2B) at which point the split molds 18, 20 are locked and the vacuum is cut off (FIG. 2B).

Liquid is then introduced into the interior of the chamber (FIG. 2C) to progressively expand the chamber and thereby radially expand the container C into general conformity with the contour of the cavity 21. At a pressure of approximately 600-800 p.s.i. the can body C is not in intimate contact with the cavity surface and any minute details thereon would not be totally and accurately transferred to the can body exterior. In order to transfer such minute details an electrical discharge is created across a gap between a pair of electrodes 19, 22 which creates a momentary shock wave resulting in a force of approximately 30,000 p.s.i. which forces the exterior of the can body C into intimate contact with the mold cavity 21.

The chamber 17 is purged, the platen 15 is decompressed and lowered (FIG. 2E), the split mold 13 is subsequently fully opened, and the now stylized can body is removed from the apparatus by a discharge star wheel 23 (FIG. 1).

DETAILED DESCRIPTION

Referring in particular to FIG. 6 of the drawings, the turret 12 includes a stationary tubular upstanding support 24 which is fixed to an underlying portion (not shown) of a frame F'. A rotatable tubular member 25 surrounds the support 24 and a lower end portion thereof includes a flange 26 to which is welded a gear 27. A suitable bearing 8 is positioned between the gear 27 and the lower end portion of the support 24 while a bushing 30 is disposed between reduced end portions 31, 32 of the support 24 and the rotatable member 25, respectively.

Another stationary support 33 (FIG. 6) of a generally annular configuration is supported above the support member 24 and in axial alignment therewith by a plurality of supporting rods 34. A bearing assembly 35 mounts a tubular member 36 for rotation relative to the stationary support 33. The tubular member 36 carries a table 37 at its upper end and is secured at its flanged lower end (unnumbered) to another tubular member 38 which is in turn secured to the reduced end portion 32 of the rotatable member 25. In this manner rotation imparted to the rotatable member 25 by the gear 27 is transferred by the tubular members 36, 38 to rotate the table 37 as well as a turret member 40 which is welded or otherwise secured to the tubular member 38.

The turret member 40 is formed by an upper annular plate 41, a lower annular plate 42 and a peripheral plate 43. Four identical transducers, each being referred to generally by the reference numeral 14, are suspendingly supported from the lower plate 42 at points equidistant from the axis of rotation of the turret member and in 90.degree. spaced relationship to each other.

Referring in particular to FIG. 18 of the drawings, each of the transducers 14 includes an internal rigid cage structure 46 defined by a plurality of circumferentially spaced conductive rods 47 which are welded at their lower ends to a conductive electrode support 48 and at their upper ends to a conductive metallic plate 50. The rods 47 pass through bores 51 in an annular insulating member 52 which is in internal telescopic relationship to an annular supporting collar 53 which is suspended from the plate 50 by a flanged clamping collar 54. A plurality of springs 55 permit limited axial movement of the collar 53 relative to the plate 50. The annular insulating member 52 further includes a pair of passages 56, 57 which are in fluid communication with respective passages 58, 59 of the plate 50 (FIG. 20) and collectively the passages 56 through 59 function to introduce a fluid medium, such as a low (4 percent) concentrate saline solution, into the interior of an expansible chamber 17 defined in part by a flexible bag-like element 61. A pair of passages 62, 63 likewise formed in the annular insulating member 52 are in fluid communication with respective passages 64, 65 of the plate 50 for purging the liquid from the chamber 17.

Another annular insulating member 66 is threadably secured to the plate 50 at its upper end portion and the electrode 19 passes through a bore 67 thereof in axially aligned spaced relationship to the electrode 22 to therebetween define an electrode-electrode gap 68 across which electrical energy is discharged to expand the bag-like element 61 radially outwardly during the second phase of the stylizing operation heretofore described in conjunction with FIG. 2D.

The bag-like element 61 is supported at its upper end portion within a chamber 70 of the collar 53 by means of a two-piece piston 71 which is mounted for limited axial movement in the chamber 70. The piston 71 is prevented from moving completely out of the chamber 70 by means of a restraining collar 72. A lower annular arcuate surface 73 of the piston 71 is contoured to clamp the peripheral flange F of each of the can bodies C in conjunction with the mold bodies 18, 20, as will be described more fully hereafter. The clamping force is increased in proportion to an increase in pressure internally of the chamber 17 by means of a pair of ports 74 which conduct incoming pressurized liquid from the passages 56, 57 into the chamber 70 above the piston 71.

Each transducer 14 is suspended from the plate 42 of the turret member 40 by a plurality of circumferentially spaced bolts 75 (FIGS. 18 and 19) received in flanged insulators 76 which project through bores 77 of the plate 42. An annular insulator 78 maintains the plate 42 in spaced relationship to a conductive plate 80 into bores 81 of which each of the bolts 75 is secured.

The conductive plate 80 is connected to the electrode 19 by a coupling 82 which includes a conductive collar 83 and a conductive plate 84. The conductive plate 80 is likewise supported in spaced relationship to the plate 50 by a plurality of bolts 85, each of which passes through insulators 86, 87 and is threadably secured in a bore 88 of the plate 50. Conductors 90, 91 are secured to the respective plates 80, 50 by bolts and nuts (unnumbered). Current will therefore flow along a path traced from the conductor 90, the conductive plate 80, the collars 83, 84, the electrode 19, the electrode 22, the support 48, the rods or pillars 47, the plate 50 and the conductor 91.

Reference is now made to FIGS. 7 through 9 which illustrate the manner in which each of the platens 15 is mounted for sliding movement upon the rotatable member 25 between a lowermost position (FIG. 9) at which time the can body C is removed from the infeed star wheel 16 to an uppermost position (FIG. 15) at which time the split mold 13 is completely closed. Four plates 92 (FIG. 8) are secured in a conventional manner to the rotatable member 25, and at upper and lower ends of each plate 92 is a radially outwardly directed bracket 93, 94, respectively (FIGS. 6, 7 and 9). The brackets 93, 94 each have a pair of bores (unnumbered) which receive cylindrical rods 95, 96. The rods 95, 96 are in parallel relationship to each other and define a slide path for a slide 97 which includes a pair of bores 98, 100 (FIG. 10) in which are received the rods 95, 96. A bracket 101 which carries the platen 15 is secured to the slide 97. Thus, upon upward movement being imparted to the slide 97 from the position shown in FIG. 9 the slide 97 is guided upwardly by the rods 95, 96 to the position shown in FIG. 24 while opposite movement is likewise guided by the rods 95, 96.

Each of the slides 97 is reciprocated upwardly and downwardly during the rotation of the rotatable member 25 by means of a cam track 102 (FIG. 6) which encircles the rotatable member 25 and is suitably secured to the frame F'. A cam roller or follower 103 is positioned in a groove 109 of the cam track and is secured to the slide 97 by a plate 104. As the rotatable member 25 rotates each slide 97 carried thereby similarly rotates as does each plate 104 and platen 15 whereupon the cam follower 103 lifts and lowers each platen 15 in sequence to the operations being performed by the apparatus 10.

Each platen 15 includes a tubular supporting head 105 which is bored at 106 and counterbored at 107 (FIG. 11). A lip of the head is rounded as at 108 to receive the bottom radius of the can body C. A cylindrical insert 110 having a peripheral flange 111 is positioned within the bore 106 while a reduced stem 112 thereof is positioned in a bore 113 of the bracket 101. A plurality of springs 114 disposed in opposed recesses of the bracket 101 and the head 105 normally urge the latter upwardly to the position illustrated in FIG. 11. However, the head 105 may move downwardly until a shoulder 115 contacts the upper surface of the bracket 101. The insert 110 is secured in the position illustrated in FIG. 11 by means of a bolt 116 which permits sliding movement and prevents rotational movement. A pin 117 force fit into a bore 118 of the bracket 101 includes an end portion slidably received in a bore 120 of the head 105 to likewise permit vertical sliding movement of the head 105 while preventing rotation thereof.

A generally inverted U-shaped bracket 121 is secured to the under side of the bracket 101 and carries cam roller or follower 122 which rides upon a cam track 123 (FIG. 14) supported by an upright support 124 of the frame F'. The function of the springs 114 is to permit the can body C to be placed under a predetermined compressive force between the head 105 and the shoulder 73 of the transducer 14 prior to the closing of the split mold 13. The function of the cam follower 122 when it is on the upper portion of the cam track 123 is to support the bracket 101 against the extremely high forces (30,000 p.s.i.) created during an electrical discharge across the electrodes 19, 22.

The can C is preferably held on the head 105 of the platen 15 by a partial vacuum created in the bore 107 (FIG. 11). The volume beneath the bottom wall of the can C is connected to a conventional vacuum source (not shown), such as a vacuum pump, by a passage 125 in the head 110, a radial port 126 (FIG. 10) in the stem 112 and a portion of the bracket 101, a port 127 which opens into the bore 98 of the slide 97, an annular chamber 128 between the bore 98 and the exterior surface of the rod 95, a radial bore 130 (FIG. 9) in the rod 95, an axial passage 131 in the rod 95, a passage 132 at the lower end of the rod 95 which passes through the plate 92 and terminates at a passage 133 in the rotatable member 25, a passage 134 and a conduit 135 which passes through an opening (unnumbered) in the gear 27. Suitable seals (unnumbered) are provided for preventing undesirable leakage.

FIG. 12 illustrates a modified platen 15' wherein a head 105' having a bore 106' and a counterbore 107' receives an insert 110' having a convex upper surface 136. The surface 136 is formed of a convex configuration to cooperate with a correspondingly contoured dome-shaped bottom B' of a container C'.

The split molds 13 are of identical construction and the mold bodies 18, 20 thereof are mounted for sliding movement relative to each other between the open and closed positions illustrated in FIGS. 7, 8 and 16. The mold bodies 18, 20 are supported from the lower plate 42 of the turret member 40 by means of a plate 140 to one side of each of the molds 13 (FIG. 8) and a pair of plates 141, 142 at an opposite side of each of the molds. The uppermost ends of the plates are welded to the under side of the plate 42 while the lower ends are rigidly connected together by a pair of cylindrical rods 143, 144. The rods 143, 144 are preferably coupled to the plates 141, 142 in a removable manner as, for example, by projecting threaded end portions through bores of the plates 140 through 142 and employing nuts to fasten the assembly whereupon the split molds 13 can be readily removed, repaired or replaced.

The mold bodies 18, 20 include aligned bores in each of which is a bushing 145, 146 through which is respectively received the rods 143, 144, as is best illustrated in FIG. 16.

The molds 13 are opened and closed by a linkage mechanism 150 (FIG. 16) which includes a pair of rods 151, 152 each of which is surrounded by bushings 153 in the bores 155. The bores 155 are in alignment with bores 156 of the mold body 20 which receive an end portion of each of the rods 151, 152. The end portions of the rods 151, 152 carry flanges 157 and are secured in position by a nut 158, in a manner clearly illustrated in FIG. 16.

Each of the rods 151, 152 includes a bifurcated end portion 160 which is secured by a pivot pin 161 to a link 162. Each of the links 162 is in turn connected to a generally T-shaped member 163 by a pin 164. The T-shaped member 163 is supported by a pair of plates 165, 166 which are welded to the under side of the plate 42 of the turret member 40, and the lower end portions thereof are pivotally connected by a pin 167 to a bifurcated extension 168 of the member 163. The extension 168 is in turn connected to a link 170 by a pin 171 and another pin 172 secures each of the links 170 to a bifurcated portion 173 of each of the mold bodies 18.

Each of the T-shaped members 163 includes a further bifurcated portion 174 which is connected to a link 175 by a pin 176. The link 175 is in turn pivotally connected by a pin 177 to a rod 178 which is mounted for sliding telescopic movement in a sleeve 180 (FIGS. 6 and 7) carried by the turret member 40. Each rod 178 is prevented from rotating by a groove and key, which is generally designated by the reference numeral 181. A cam follower or roller 182 is carried by the upper end portion of each of the rods 178 and is received in a cam track 183 which is fixedly secured to the under side of the stationary support 33, in the manner best illustrated in FIG. 6 of the drawings.

As the turret member 40 rotates the follower 182 moves in the track 183 to raise and lower each of the rods 178 to respectively close and open each of the split molds 13, in the manner best illustrated in FIG. 17. Upon upward movement of the rods 178, the rods 151, 152 are drawn to the left as viewed in FIG. 16 to pull along therewith the mold body 20 while the downward pivoting movement of the extension 168 from the position shown in FIG. 17 to that shown in FIG. 16 moves the mold body 18 from left to right until the bodies are in the closed position shown in FIG. 16. It will be noted that the link 170 applies a force through the mold body 18 in a direction opposite to that which draws the mold body 20 toward the mold body 18. Thus, it is possible by the linkage mechanism 150 to preload the split molds 13 in the closed position to thereby effectively resist forming forces which might otherwise tend to open the same.

Reference is now made to FIGS. 24 and 25 of the drawings which illustrate a pair of contacts 185, 186 secured by bolts 187 to an insulating plate which is in turn secured by bolts 190 to a bifurcated bracket 191 which is secured to a vertical plate 192. The plate 192 is fixedly secured in any conventional manner, as by welding, adjacent each of the transducers. The contact 186 is connected to its associated transducer by the conductor 90 while the contact 185 is connected to the transducer by the conductor 91.

Another pair of contacts 195, 196 are supported from a post 197 adjacent the rotatable turret member 40. The contacts 195, 196 are each secured by bolts and nuts 197 to a generally L-shaped insulating member 198 having a recess 200 in which is seated a plate 201 having an arcuate aperture 202 through which passes a bolt 203. A pivot pin 204 and an insulating bushing associated therewith journals each of the members 198 for slight pivoting movement relative to the pivot pin 204, as indicated by the unnumbered double headed arrows in FIG. 25. A spring 205 is connected to each of the plates 201 and a pin 206 passing through a support member 207 which is conventionally secured to an upstanding support 208 of the apparatus frame F'. The contacts 195, 196 are mounted for pivotal movement to permit the faces thereof to come into intimate contact during the rotation of the rotatable member 40 such that upon reaching the position shown in FIGS. 24 and 25 a discharge is created across the electrodes 19, 22 from a source of electrical energy (not shown) such as a storage inductor or capacitor which is connected to the contacts 195, 196 by conductors (not shown).

A pair of rotary valves 210, 211 (FIG. 22) form part of a hydraulic system 215 (FIG. 4) of the apparatus 10. The valve 210 includes a sleeve-like housing 212 which rotates with the tubular member 38 and includes four conduits 213 which pass through openings 214 and are each connected to an associated one of the transducers 14. A stationary sleeve 216 is fixedly support atop a rigid conduit 217 and includes an interior chamber 218 which is connected to an annular channel 220 of the housing 212 by four ports 221. Liquid within the chamber 218 is connected to a drain by means of a plurality of tubular bolts 222 of the valve 210 which open into the chamber 218 and into an annular passage 223 formed between the conduit 217 and another conduit 224. The conduit 217 is connected to a check valve 225 (FIG. 4) and to a conduit 226 which is in turn connected to a pump 227.

The valve 211 delivers low concentrated saline solution to the various transducers by means of the conduit 224, a chamber 228 in the sleeve 216, a plurality of ports 230 in the sleeve 216, an annular channel 231, and a plurality of conduits 232 which are each connected to one of the transducers 14 and a fluid isolator 235 (FIG. 4) in a manner which will be described immediately hereafter in conjunction with a description of the operation of the apparatus 10.

STYLIZING OPERATION

The infeed star wheel 16 rotates counterclockwise as viewed in FIG. 1 during which time the clockwise rotation of the turret 12 brings the platen 15 into underlying axial registration with the can body C. At this time a vacuum is being drawn over the flow path heretofore described relative to FIGS. 9 through 11 of the drawings and as the can body C seats upon the shoulder 108 (FIG. 11), the can body C is firmly held upon the head 105 of the platen 15 as the latter begins to rise as the cam follower 103 (FIG. 6) moves upwardly under the influence of the cam track 109 (FIG. 6). During this upward movement the platen 15 is guided by the slide 97 as it moves upwardly along the rods 95, 96 (FIGS. 7 to 9).

During the upward movement of the platen 15 a solenoid valve SV6 (FIG. 4) is operated to conduct water from a suitable source through a conduit 236 to the pump 227 to avoid loss of its "prime." The solenoid valve SV6 is one of a plurality of valves associated with each of the transducers which is operated in sequence by a plurality of timing cams (not shown) which are rotated in a conventional manner in synchronism with the rotation of the turret 12 to initiate the various operations of the apparatus 10.

A pair of solenoid valves SV3 and SV5 are then operated to conduct a low (4 percent) concentrate saline solution to an outlet chamber 237 of the intensifier 235 and to the chamber 17 of the transducer 14. The saline solution is created by conducting water from a suitable source through a valve 238 (FIG. 4) and diverting the flow through a check valve 240, a needle valve 241, a brine tank 242 and a conventional rotometer 242 which monitors the saline solution flowing through a conduit 243 which, as need be, may be supplied with fresh water flowing through a check valve 244, a needle valve 245, a pressure regulator 246 and a rotometer 247 to provide the desired concentrate of the solution to the conduit 224 which delivers the same to the chamber 228 of the valve 211 (FIG. 22) and thence to a selected one of the transducers through the conduit 232 which is connected to a conventional accumulator 251 by a conduit 252. The conduit 252 continues the flow of the solution through a valve (unnumbered) of the solenoid valve SV5, a conduit 253, a check 254, a conduit 255, a conduit 256 which includes a branch 257 having a check valve 258 and conduits 260, 261 (FIG. 5) which are connected to the ports 58, 59 (FIG. 20). This begins to fill the chamber 17 of the transducer 14 with the low concentrate saline solution, and also fills the outlet chamber 237 of the fluid isolator 235 through a conduit 262.

The platen 15 continues to rise and eventually reaches the top of its stroke at which time the flange F contacts the shoulder 73 of the transducer piston 71 and upon the contact of the cam follower 122 with the cam surface 123 (FIG. 14) the head 105 compresses the springs 114 to intimately urge the flange F against the shoulder 73, as is best illustrated in FIG. 18. This upward movement also raises the piston 71 slightly upwardly from the position shown in FIG. 18 to allow clearance between the can body flange F and clamping shoulders 263 of each of the mold bodies 18, 20 as they are closed about the can body C.

After the platen 15 is fully raised and the springs 114 are compressed the die bodies 18, 20 begin to close as the cam follower 182 (FIGS. 6 and 16) begins to rise by means of the cam track 183 which draws the associated rod 178 upwardly to eventually close the mold through the linkage 150, in the manner heretofore described.

The vacuum is now cut off to the platen 15 in a conventional manner and the solenoid valve SV5 is closed to terminate the saline solution feed. A solenoid valve SV2 is then operated to switch a valve 264 to its power position at a time that the chamber 17 is at line pressure (40 p.s.i.) and after the mold bodies 18, 20 have been fully closed. During the introduction of the solution into the chamber 17 air is expelled between the container body C and the exterior of the bag-like element 61 as the latter conforms to the contour of the can body C, although the latter is not deformed at this time. A continuously operating motor M (FIG. 4) drives a pump 265 to conduct hydraulic fluid into a chamber 266 of the isolator 235 behind a piston 267 over a flow path defined by a conductor 268, a check valve 270, a conventional rotary joint 271 carried by the rotating table 37 (FIG. 6), a conduit 272, and a conduit 273. As the pressure begins to increase in the chamber 266 a piston 279 begins to move downwardly to increase the pressure in an accumulator 274 through a conduit 275 and to also increase the pressure within the chamber 17 through the conduit 262, the conduit 256, the conduits 260, 261, the ports 58, 59, and the passages 56, 57. The pressure is increased in the chamber 17 until it is approximately between 600-800 p.s.i. at which time the bag-like element 61 is expanded radially outwardly to force the container body into general conformity with the mold cavity 21. However, at this time the fluid pressure is insufficient to intimately urge the exterior surface of the can body C into intimate relationship to the fine details of the mold cavity surface.

The introduction of the fluid into the chamber 17 also increases the clamping force exerted upon the can body flange F due to the ports 74 (FIG. 18). The gradual expansion of the can body C also expels air from between the can body and the die except in the fine detail areas.

The continued rotation of the turret 12 eventually brings the rotary contacts 185, 186 into alignment with the stationary contacts 195, 196, respectively, which closes a circuit from the stored energy source (not shown) which causes a discharge across the electrodes 19, 22 and the spark gap 68 to cause a momentary shock wave which expands the bag-like element 61 further outwardly at a force up to 30,000 p.s.i. This results in the further radial expansion of the can body C and urges the exterior surface thereof into intimate contact with the fine detailed portions of the mold cavity 21. An ignitron may be placed in series with the stored energy source to more accurately control the discharge of the capacitor and the ensuing electrohydraulic (E-H) pulse. While a force of 30,000 p.s.i. has been indicated as being satisfactory for most operations, the pressure developed may be approximately between 25,000-75,000 p.s.i. for less than 100 micro-second at a capacitor discharge across the electrodes of 30,000 joules at 10,000 volts.

After the can has been "stylized" the solenoid valves SV2 and SV6 are closed to respectively remove the drive pressure to the fluid isolator 235 and to close the flow from the conduit 236 to the pump 227. With the valve 264 now in its drained position the pressure in the accumulator 274 acting through the conduit 275 forces the piston 279 upwardly and hydraulic fluid in a chamber 266 is conducted to a reservoir by the conduit 273, the valve 264, a conduit 278, a rotary valve 280 adjacent the rotary valve 271, a conduit 281 and a reservoir 282 which is preferably connected to the pump 265 by a conduit 283. As the piston 273 rises fluid is withdrawn from the chamber 17 through the passages 62, 63 (FIG. 20), passages 64, 65, conduits 237, 238 and a conduit 262 until such time as the pressure within the chamber 17 is zero, as is the pressure within the chamber 70 (FIG. 18) which releases the clamping force of the piston 71. As the mold bodies begin to open a solenoid valve SV4 is operated to its open position and the centrifugal pump 227 continues to remove the fluid from the chamber 17 through the conduits 287, 288, the conduit 213 (FIG. 22) of the valve 210, the valve 210, the conduit 217, the check valve 225 and the conduit 226. The centrifugal pump 227 creates a vacuum internally of the chamber 17 such that the bag-like element 61 collapses against the pillars 47 of the cage 46 (FIG. 2E) to permit the now stylized can body to be readily removed therefrom during downward movement of the platen 15.

Vacuum is again applied to the platen 15 to clamp the stylized can body to the head 105 and the platen 15 begins to lower as its roller 122 descends along the cam surface 123 to completely decompress the springs 114 just prior to the die bodies reaching their fully opened position under the influence of the cam track 183, the cam follower 182 and the rod 178 associated with the linkage mechanism 150. After the die bodies 18, 20 are fully open and the springs 114 are fully decompressed, the platen 15 begins to lower as the follower 103 descends to the lower position of the cam track 109, after which the vacuum to the platen is discontinued and the stylized can body is discharged to the star wheel 21.

Between approximately 302.degree.-312.degree. the cam track 183 is contoured to close the die bodies partially in order that the die bodies can clear the star wheels 16, 21, the vacuum is again applied to the platen 15 for subsequent can body pick-up, and the solenoid valves SV4 and SV6 are respectively closed and opened to terminate the draining of the chamber 17 and the intensifier 235, and to provide water to the evacuation pump 227 to prevent the loss of its prime. Thereafter the cycle of the apparatus 10 continues in the manner heretofore described.

It is pointed out that the saline solution is a corrosive liquid and care must be taken in order that the saline solution does not admix with the noncorrosive hydraulic fluid introduced into the chamber 226 of the fluid isolator 235 (FIG. 4). To this end a pair of O-ring seals 290, 291 surround the piston 279 on opposite sides of the radial port 292 which is connected by a conduit 293 to a check valve 294 which is in turn connected by a conduit 295 to the conduit 213. Any hydraulic fluid which seeps past the O-ring seal 290 is thereby withdrawn from the area between the seals 290, 291 during the purging of the chamber 17 upon the operation of the centrifugal pump 227. Likewise, any of the corrosive saline solution which seeps upwardly past the O-ring seal 291 is likewise conducted to drain through the port 292, the conduit 293, the check valve 294, etc. during the purging of the chamber 17.

If some slight contamination of the saline solution does occur, it may be removed prior to being introduced into the chamber 237 of the isolator 235 by removing a portion of the conduit 262 and directing the saline solution from the conduit 255 directly to the conduit 284, a filter 296, a check valve 297 and a conduit 298 connected to the remaining portion of the conduit 262, while reverse flow can be prevented by a conduit 300, a check valve 301, and a conduit 302.

While preferred forms and arrangements of parts have been shown in illustrating the invention, it is to be clearly understood that various changes in details and arrangement of parts may be made without departing from the spirit and scope of this disclosure.

Claims

The embodiments of the invention in which an exclusive property or privelege is claimed are defined as follows:

1. Apparatus for reforming tubular elements comprising means for conveying tubular elements between loading and discharging stations, mold means carried by said conveying means for receiving the tubular elements in cavities of said mold means, flexible chamber means internally of each mold means and in telescopic relationship to the tubular element therein, means for periodically conducting a fluid medium into said chamber means, means for generating an electrical discharge in said chamber means whereby each tubular element is reformed by the fluid medium to the configuration of the cavities, means for opening each mold means for the removal of each reformed tubular element therefrom, means surrounding said chamber means for clamping a peripheral edge of each tubular element against cooperating clamping surface means of each mold means, means for increasing the pressure of the fluid medium in the chamber means prior to the operation of said generating means, and means for increasing the clamping force between said clamping means and said clamping surface means depending upon the increase of pressure of the fluid medium in the chamber means.

2. Apparatus for reforming tubular elements comprising means for conveying tubular elements between loading and discharging stations, mold means carried by said conveying means for receiving the tubular elements in cavities of each mold means, flexible chamber means internally of each mold means and in telescopic relationship to the tubular element therein, means for periodically conducting a fluid medium into said chamber means, means for generating an electrical discharge in said chamber means whereby each tubular element is reformed by the fluid medium to the configuration of the cavities, means for opening each mold means for the removal of each reformed tubular element therefrom, means surrounding said chamber means for clamping a peripheral edge of each tubular element against cooperating clamping surface means of each mold means, said surrounding means is a member mounted for sliding movement externally of said chamber means, and means for moving said member toward said clamping surface means for clamping the peripheral edge of each tubular element.

3. Apparatus for reforming tubular elements comprising means for conveying tubular elements between loading and discharging stations, mold means carried by said conveying means for receiving the tubular elements in cavities of said mold means, flexible chamber means interiorly of each mold means and in telescopic relationship to the tubular element therein, means for periodically conducting a fluid medium into said chamber means, means for generating an electrical discharge in said chamber means whereby each tubular element is reformed by the fluid medium to the configuration of the cavities, means for opening each mold means for the removal of each reformed tubular element therefrom, means surrounding said chamber means for clamping a peripheral edge of each tubular element against cooperating clamping surface means of each mold means, said surrounding means is an annular piston mounted for sliding movement externally of said chamber means, a housing surrounding said piston and defining a chamber therewith, and means for introducing a fluid medium into said chamber for moving said piston toward said clamping surface means for clamping the peripheral edge of each tubular element.

4. Apparatus for reforming tubular elements comprising means for conveying tubular elements between loading and discharging stations, mold means carried by said conveying means for receiving the tubular elements in cavities of said mold means, flexible chamber means internally of each mold means and in telescopic relationship to the tubular element therein, means for periodically conducting a fluid medium into said chamber means, means for generating an electrical discharge in said chamber means whereby each tubular element is reformed by the fluid medium to the configuration of the cavities, means for opening each mold means for the removal of each reformed tubular element therefrom, said tubular elements are closed at one end thereof and are open at another end, rigid immovable means for clamping the closed end of each tubular element between said chamber means and said mold means, and means for clamping the open end of each tubular element between said chamber means and said mold means whereby the reformed tubular elements are of generally uniform heights due to localized reforming of the tubular elements between the clamped ends thereof.

5. Apparatus for reforming tubular elements comprising means for conveying tubular elements between loading and discharging stations, mold means carried by said conveying means for receiving the tubular elements in cavities of said mold means, flexible chamber means internally of each mold means and in telescopic relationship to the tubular element therein, means for periodically conducting a fluid medium into said chamber means, means for generating an electrical discharge in said chamber means whereby each tubular element is reformed by the fluid medium to the configuration of the cavities, means for opening each mold means for the removal of each reformed tubular element therefrom, said mold means include a plurality of split molds, each split mold is defined at least in part by a pair of mold bodies which are movable away from each other by said opening means and toward each other by closing means, said opening and closing means include linkage means coupled to each of said mold bodies, one of said linkage means is operative by said closing means to draw one of the pair of mold bodies toward and into contact with the other of the mold bodies, and the other of said linkage means is operative by said closing means to push the other of the mold bodies toward and into contact with said one mold body.

6. The reforming apparatus as defined in claim 5 wherein said one and another linkage means include a plurality of pivotal links, and said links are disposed in generally parallel relationship in the closed position of said mold bodies.

7. The reforming apparatus as defined in claim 6 including means mounting said mold bodies for guidable sliding movement relative to each other between the open and closed positions thereof.