CA1224430A - Integral end profile for a buckle resistant sanitary can and method of manufacture - Google Patents
Integral end profile for a buckle resistant sanitary can and method of manufactureInfo
- Publication number
- CA1224430A CA1224430A CA000426062A CA426062A CA1224430A CA 1224430 A CA1224430 A CA 1224430A CA 000426062 A CA000426062 A CA 000426062A CA 426062 A CA426062 A CA 426062A CA 1224430 A CA1224430 A CA 1224430A
- Authority
- CA
- Canada
- Prior art keywords
- bottom wall
- wall
- groove
- radius
- rim
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D51/00—Making hollow objects
- B21D51/16—Making hollow objects characterised by the use of the objects
- B21D51/26—Making hollow objects characterised by the use of the objects cans or tins; Closing same in a permanent manner
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D1/00—Containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material, by deep-drawing operations performed on sheet material
- B65D1/12—Cans, casks, barrels, or drums
- B65D1/14—Cans, casks, barrels, or drums characterised by shape
- B65D1/16—Cans, casks, barrels, or drums characterised by shape of curved cross-section, e.g. cylindrical
- B65D1/165—Cylindrical cans
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Ceramic Engineering (AREA)
- Rigid Containers With Two Or More Constituent Elements (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A sanitary can body is formed with an integral bottom wall which is pulled tight and profiled to form a series of concentric panels which are drawn taut and placed in tension by overstriking with the profiling tools., The resulting can, when manufactured of high strength plate, exhibits high resistance to buckling and good springback retention even when the plate weight is light.
A sanitary can body is formed with an integral bottom wall which is pulled tight and profiled to form a series of concentric panels which are drawn taut and placed in tension by overstriking with the profiling tools., The resulting can, when manufactured of high strength plate, exhibits high resistance to buckling and good springback retention even when the plate weight is light.
Description
` ' 322~0 B~CR~ROUND OF THE INVENTION
This invention relateæ to sanitary cans and more particularly to sanitary cans whera the bottom wall is integral with the side wall is distinct from a can body where the bottom wall is a separate disc which is seamed or ~oined to the cylindrical side wall. Such cans7 which flnd application as packages for a variety of food products are manufactured by a draw/redraw process wherein steel strip is blanked, drawn and redrawn to fonm a basic container body.
The basic container body ~s then flanged, contoured or profiled, trimmed and may even have the side wall strengthened by beading. The instant application is directed to the contouring or profiling of the integral bottom wall of the container body to strengthen it and provide a stable configuration.
A major market for the drawn can is the pet food market where the can is packed at low vacuum and its conten~s are sub~ected to severe process1ng conditlons. The can must be capable of withstanding the internal pressures developed dur~ng processing and pasteurization to avoid permanent distortionr That is, any d~stor~ion or bulging which occur3 during the processing must be overcome by the springback or pullback properties of the can body when the can has cooled.
Permanent distortion is termed buckling. Such a condition is objectionable because it lnterferes with container stacklng and even more so because it suggests that the container contents may be spoiled~ and therefore is unmarketable.
~ 2~43(~ ' Bucklin~ can occur during sPrvice as well as during processing. For example, cans packaged with pet food at a West l'oast cannery at sea level, and shipped over the Rocky Mountains to Denver, Colorado were ound ~o be permanently distended by the low atmospheric pressure encountered at the elevated altitudes during shipment.
This cannery has established a specification which called for the can to resi3t buckling at internal pressures as high as 25 psi and to have springback retention wherein the can body returned to its original eonfiguration when the internal pressures did not exceed 20 psi.
While heavy plate such as 701b. plate will necessarily afford increased strength and resistance to permanent distention, such a solution imposes an economic penalty which must ultimately be borne by the consumer.
Accordingly, it is an ob;ect of this invention to provide a sanitary can body with an integral bottom wall which affords a high level of resistance to permanent dlstortion by buckling and where the springback retention of ~he integral bottom wall ensure a stable configuration.
It is further an ob~ect of this invention to provide a sanitary can body wherein the buckle resistance exceeds ~5 psi and the sprlngback retention exceeds 20 psl.
It is further an ob~ec~ of this invention to provide a sanitary can body with an integral bottom wall which affords a high level of buckle and springback retention when msnufectured of high strength light weight plate.
This invention relateæ to sanitary cans and more particularly to sanitary cans whera the bottom wall is integral with the side wall is distinct from a can body where the bottom wall is a separate disc which is seamed or ~oined to the cylindrical side wall. Such cans7 which flnd application as packages for a variety of food products are manufactured by a draw/redraw process wherein steel strip is blanked, drawn and redrawn to fonm a basic container body.
The basic container body ~s then flanged, contoured or profiled, trimmed and may even have the side wall strengthened by beading. The instant application is directed to the contouring or profiling of the integral bottom wall of the container body to strengthen it and provide a stable configuration.
A major market for the drawn can is the pet food market where the can is packed at low vacuum and its conten~s are sub~ected to severe process1ng conditlons. The can must be capable of withstanding the internal pressures developed dur~ng processing and pasteurization to avoid permanent distortionr That is, any d~stor~ion or bulging which occur3 during the processing must be overcome by the springback or pullback properties of the can body when the can has cooled.
Permanent distortion is termed buckling. Such a condition is objectionable because it lnterferes with container stacklng and even more so because it suggests that the container contents may be spoiled~ and therefore is unmarketable.
~ 2~43(~ ' Bucklin~ can occur during sPrvice as well as during processing. For example, cans packaged with pet food at a West l'oast cannery at sea level, and shipped over the Rocky Mountains to Denver, Colorado were ound ~o be permanently distended by the low atmospheric pressure encountered at the elevated altitudes during shipment.
This cannery has established a specification which called for the can to resi3t buckling at internal pressures as high as 25 psi and to have springback retention wherein the can body returned to its original eonfiguration when the internal pressures did not exceed 20 psi.
While heavy plate such as 701b. plate will necessarily afford increased strength and resistance to permanent distention, such a solution imposes an economic penalty which must ultimately be borne by the consumer.
Accordingly, it is an ob;ect of this invention to provide a sanitary can body with an integral bottom wall which affords a high level of resistance to permanent dlstortion by buckling and where the springback retention of ~he integral bottom wall ensure a stable configuration.
It is further an ob~ect of this invention to provide a sanitary can body wherein the buckle resistance exceeds ~5 psi and the sprlngback retention exceeds 20 psl.
It is further an ob~ec~ of this invention to provide a sanitary can body with an integral bottom wall which affords a high level of buckle and springback retention when msnufectured of high strength light weight plate.
- 2 -12;~4430 It is finally an object of this lnvention to provide a method for manufacturing sanitary can bodies of light weight high strength plate which is compatible with conventional equipment and which ensures a high level of buckle resistance and springback retention.
SUMMARY QF TH~ I~VENTION
It may be seen that the aforementloned objects of the inventlon may be attained in a sanitary can body of the type having a peripheral outer flange at the top end of the can body, a cylindrical side wall symmetrical about an axis of rotation and joined to said flange, and a bottom wa~l Integral with the side wall and wherein the improvement is a profiled ¦ bottom wall comprising a peripheral rim, an annular upwardly directed coun~ersink groove, an annular outer panel, an snnular midpanel and an inner panel.
The peripheral bottom rim is ormed with an inwardly inclined outer rim wall, and an inner rlm wall, with said inner snd outer rim walls converging to form the root of the rimO The rim root is substantially tangent to a base plane~
¦which in turn is perpendicular to the axis of rotation. The linner wall of the rim is substantially perpendlcular to the base plane.
The annular countersink groove is upwardly directed being adjacent to and inwardly disposed of the rim, the countersink groove is formed with a radius of curvature of .050"
culminating at the crest of the groove. The outer groove wall merges with the inner rim wall.
~ 4~30 The annular outer panel, is disposed inwardly of ~he countersink groove and concentric theretoO The panel lies iD
a plane parallel ~o the base plane. The plane o the outer panel lies between the base plane which is tangent to the root of the rim and a plane tangent to the groove crest. The outer panel i8 ~oined to the inner wall o~ ~he countersink groov~ by a fllet or concavity which has a radius of curvature of .035".
The annular midpanel is disposed inwardly of the outer panel, concentric and parallel thereto and lying on a plane between the plane of the outer panel and the plane tangent to the groove crest. The midpanel is joined to the outer panel by an ogee. The ogee consists of an outer f;let and an inner convergence each of which have a radius o curvature of .035".
The inner panel is disposed inwardly of the midpanel and parallel thereto and lies on a plane between the midpanel plane and the plane tangent to the crest of the groove. The inner panel is joined to the midpanel by an ogee with an outer filet and an inner convergence each w~th a radius of curvature of .035".
The profiled bottom wall ls preferably drawn taut and placed in tension so that the panels resist permanent distention.
The sanitary can body is preferably made of TFS-CT
chromium treated tln free steel) which has been double educed with a DR9 temper and having a plate welght of 60 lbs.
er base box and a plate thickness of .0066~. A sanitary can anufactured by joining a closure to this sanitary can body as been found to resist buckling when sub~ected to internal pressures as high as 30-32 psi. Further9 lt has been shown that when ~he internal pressure does not exceed 30 psi the can body will exhibit springback by returning to the original configuration when the internal pressure is released.
The integral bottom wall of the sanitary can body is profiled by receiving the unprofiled can body in a cushioned barrel which has a bore substanti~lly equal in diam~ter to the external diameter of the finished can body, and whPrein the flange of the can body is supported by the barrel. The flange i~ clamped to the barrel. A punch sleeve with an external diameter subs~antially equal to the internal diameter of the can is introduced lnto the can body so that the nose of the punch sleeve engages the peripheral of the bottom wall o the can body thereby formlng the outer wall of ~he peripheral bottom rim. The invention will be described as if the portions of the tooling move independently. This is not essential to ~he satisfactory performance of ~he invention since some of the tool can move as a uni~. The cushloned barrel and the punch ~leeve are advanced carrying forward the clamped can body and causing the can body to engage a peripheral bead of a first or lower profile pad thereby completing formation of the bottom rim and pulling the planar bo~tom panel tightly across the crest of the peripheral bead.
A second or upper profile pad, coaxially received within the punch sleeve, is then advanced to engage the ~ight planar bottom wall between the flrst and second proflle pads thereby pulling the bottom wall over the peripheral bead to form the countersink groove and to initiate the forming of the outer 1~443(~
panel, ~he mldpanel and the inner panel. Further advanclng the second prufile pad to over6trike the bottom wall and thereby to fully set and define the countersink groo~e, the outer panel, the midpanel and the inner panel to tension the bottom wall and make the panel tau~ and flat. In another arrangement the upper profile pad and sleeve may move together as a unit when forming the end profile.
BRIEF DESCRIPTIO~ OF THE DRAWINGS
Figure 1 is an elevatlonal view of a sanitary can body with an integral bottom wall.
Figure 2 is a plan view of the sanitary can body of Figure 1.
Figure 3 is an enlarged sectional view of the can body taken in elevstion along the line 3-3 of Figure 2.
Figure 4 is an enlarged fragmentary cross sectlonal view through the dies for profiling the bottom wall of the can body. ThP can body is shown mounted on the puneh ln position for paneling.
Figure 5 is an enlarged fragmentary cross sect~on view through the dies for profiling the bottom wall of the can body. The ~an body is shown advanced by the punch sleeve so that the bottom wall is pulled tight.
Figure 6 i5 an enlarged fragmentary cross sectional view through the dies for profillng the bottom wall of the can body. The bottom wall is shown fully engaged by the upper and lower profiling pads whereby the panels are pulled taut and placed in tension.
~L2~4a~30 DETAILED DESCRIPTION OF T~E ILL~STRATED EMBODIMENT
Turning now in detail to Figures 1 and 2 of the appended drawings therein lllustrated is a sanitary can body embodying the present invention and comprising a cylindrical can body with a side wall an integral bottom, profiled to provide a stable configuration~ res1stant to buckling and with good springback retentlon. The can body has an open top wi~h a peripheral flange to which a can closure may be seamed in a conventional manner. The can body i9 drawn from chromium treated tin free steel wh~ch has been double reduced with a DR9 temper and a 60 lb plate weight. The can body ls employed for packagin~ low vacuum food products, specifically pet foods. The can body is a 307 x 112 with a flange diameter 34 equal to 3.500", an internal diameter 36 equal to 3.300" and a ¦ can height 38 of 1.750". Merely by changing the diameter of the bottom inner panel 58 is is possible to employ the configuration described to a wide range of can diameters.
The can body 20 has a side wall 26 which is inwardly inclined toward the base to form a peripheral rim 40 with a roo~ 41 upon which ~he can body rests~ The can body, which is symmetrical about axis of rotation 11-11 has a peripheral flange 22. The bottom wall 24 of the can body is profiled w~th a countersink groove 46, an outer planar panel 52, a midplanar panel 55 and an inner or central planar panel 58.
For convenience, a one-quarter section of the can body is shown in elevation in Figure 3. It should be noted however, 12~4430 ~hat dimensions 34, 36, 59, 60, 62, 64, 66, 68, 70 and 72 of Figure 3 are diametrical distances rather than radial distances from the ll-ll axis.
The peripheral flange 22 of the can bod~ 20 joins the side wall 26 with a conver~ence having a radlus of curvation 30 of .050". A break in the side wall occurs at 28, .2" above the plane of the base of the container body to form the periplleral supportlng rim 40. The outer wall 42 of the rim is lnwardly inclined to the slde wall 26. The outer wall 42 meets the inner wall 45 at the root of the rim 41, the location at which the plane of the ba~e of the container body effectively is tangent to the rim. The outer wall of the rim is formed with a convergence having a radius of curvature 43 equal to .044", with an origi~ located a distance 78 equal to .051" above the base plane and on a circle with a diameter 59 equal to 3.128". The inner wall of the rim is formed with a convergenee having a radius of curvature 44 equal to .OS0"
wlth an origin located a distance 80 equal ~o .057" above the base plane and lying on a circle with a diameter 60 equal to
SUMMARY QF TH~ I~VENTION
It may be seen that the aforementloned objects of the inventlon may be attained in a sanitary can body of the type having a peripheral outer flange at the top end of the can body, a cylindrical side wall symmetrical about an axis of rotation and joined to said flange, and a bottom wa~l Integral with the side wall and wherein the improvement is a profiled ¦ bottom wall comprising a peripheral rim, an annular upwardly directed coun~ersink groove, an annular outer panel, an snnular midpanel and an inner panel.
The peripheral bottom rim is ormed with an inwardly inclined outer rim wall, and an inner rlm wall, with said inner snd outer rim walls converging to form the root of the rimO The rim root is substantially tangent to a base plane~
¦which in turn is perpendicular to the axis of rotation. The linner wall of the rim is substantially perpendlcular to the base plane.
The annular countersink groove is upwardly directed being adjacent to and inwardly disposed of the rim, the countersink groove is formed with a radius of curvature of .050"
culminating at the crest of the groove. The outer groove wall merges with the inner rim wall.
~ 4~30 The annular outer panel, is disposed inwardly of ~he countersink groove and concentric theretoO The panel lies iD
a plane parallel ~o the base plane. The plane o the outer panel lies between the base plane which is tangent to the root of the rim and a plane tangent to the groove crest. The outer panel i8 ~oined to the inner wall o~ ~he countersink groov~ by a fllet or concavity which has a radius of curvature of .035".
The annular midpanel is disposed inwardly of the outer panel, concentric and parallel thereto and lying on a plane between the plane of the outer panel and the plane tangent to the groove crest. The midpanel is joined to the outer panel by an ogee. The ogee consists of an outer f;let and an inner convergence each of which have a radius o curvature of .035".
The inner panel is disposed inwardly of the midpanel and parallel thereto and lies on a plane between the midpanel plane and the plane tangent to the crest of the groove. The inner panel is joined to the midpanel by an ogee with an outer filet and an inner convergence each w~th a radius of curvature of .035".
The profiled bottom wall ls preferably drawn taut and placed in tension so that the panels resist permanent distention.
The sanitary can body is preferably made of TFS-CT
chromium treated tln free steel) which has been double educed with a DR9 temper and having a plate welght of 60 lbs.
er base box and a plate thickness of .0066~. A sanitary can anufactured by joining a closure to this sanitary can body as been found to resist buckling when sub~ected to internal pressures as high as 30-32 psi. Further9 lt has been shown that when ~he internal pressure does not exceed 30 psi the can body will exhibit springback by returning to the original configuration when the internal pressure is released.
The integral bottom wall of the sanitary can body is profiled by receiving the unprofiled can body in a cushioned barrel which has a bore substanti~lly equal in diam~ter to the external diameter of the finished can body, and whPrein the flange of the can body is supported by the barrel. The flange i~ clamped to the barrel. A punch sleeve with an external diameter subs~antially equal to the internal diameter of the can is introduced lnto the can body so that the nose of the punch sleeve engages the peripheral of the bottom wall o the can body thereby formlng the outer wall of ~he peripheral bottom rim. The invention will be described as if the portions of the tooling move independently. This is not essential to ~he satisfactory performance of ~he invention since some of the tool can move as a uni~. The cushloned barrel and the punch ~leeve are advanced carrying forward the clamped can body and causing the can body to engage a peripheral bead of a first or lower profile pad thereby completing formation of the bottom rim and pulling the planar bo~tom panel tightly across the crest of the peripheral bead.
A second or upper profile pad, coaxially received within the punch sleeve, is then advanced to engage the ~ight planar bottom wall between the flrst and second proflle pads thereby pulling the bottom wall over the peripheral bead to form the countersink groove and to initiate the forming of the outer 1~443(~
panel, ~he mldpanel and the inner panel. Further advanclng the second prufile pad to over6trike the bottom wall and thereby to fully set and define the countersink groo~e, the outer panel, the midpanel and the inner panel to tension the bottom wall and make the panel tau~ and flat. In another arrangement the upper profile pad and sleeve may move together as a unit when forming the end profile.
BRIEF DESCRIPTIO~ OF THE DRAWINGS
Figure 1 is an elevatlonal view of a sanitary can body with an integral bottom wall.
Figure 2 is a plan view of the sanitary can body of Figure 1.
Figure 3 is an enlarged sectional view of the can body taken in elevstion along the line 3-3 of Figure 2.
Figure 4 is an enlarged fragmentary cross sectlonal view through the dies for profiling the bottom wall of the can body. ThP can body is shown mounted on the puneh ln position for paneling.
Figure 5 is an enlarged fragmentary cross sect~on view through the dies for profiling the bottom wall of the can body. The ~an body is shown advanced by the punch sleeve so that the bottom wall is pulled tight.
Figure 6 i5 an enlarged fragmentary cross sectional view through the dies for profillng the bottom wall of the can body. The bottom wall is shown fully engaged by the upper and lower profiling pads whereby the panels are pulled taut and placed in tension.
~L2~4a~30 DETAILED DESCRIPTION OF T~E ILL~STRATED EMBODIMENT
Turning now in detail to Figures 1 and 2 of the appended drawings therein lllustrated is a sanitary can body embodying the present invention and comprising a cylindrical can body with a side wall an integral bottom, profiled to provide a stable configuration~ res1stant to buckling and with good springback retentlon. The can body has an open top wi~h a peripheral flange to which a can closure may be seamed in a conventional manner. The can body i9 drawn from chromium treated tin free steel wh~ch has been double reduced with a DR9 temper and a 60 lb plate weight. The can body ls employed for packagin~ low vacuum food products, specifically pet foods. The can body is a 307 x 112 with a flange diameter 34 equal to 3.500", an internal diameter 36 equal to 3.300" and a ¦ can height 38 of 1.750". Merely by changing the diameter of the bottom inner panel 58 is is possible to employ the configuration described to a wide range of can diameters.
The can body 20 has a side wall 26 which is inwardly inclined toward the base to form a peripheral rim 40 with a roo~ 41 upon which ~he can body rests~ The can body, which is symmetrical about axis of rotation 11-11 has a peripheral flange 22. The bottom wall 24 of the can body is profiled w~th a countersink groove 46, an outer planar panel 52, a midplanar panel 55 and an inner or central planar panel 58.
For convenience, a one-quarter section of the can body is shown in elevation in Figure 3. It should be noted however, 12~4430 ~hat dimensions 34, 36, 59, 60, 62, 64, 66, 68, 70 and 72 of Figure 3 are diametrical distances rather than radial distances from the ll-ll axis.
The peripheral flange 22 of the can bod~ 20 joins the side wall 26 with a conver~ence having a radlus of curvation 30 of .050". A break in the side wall occurs at 28, .2" above the plane of the base of the container body to form the periplleral supportlng rim 40. The outer wall 42 of the rim is lnwardly inclined to the slde wall 26. The outer wall 42 meets the inner wall 45 at the root of the rim 41, the location at which the plane of the ba~e of the container body effectively is tangent to the rim. The outer wall of the rim is formed with a convergence having a radius of curvature 43 equal to .044", with an origi~ located a distance 78 equal to .051" above the base plane and on a circle with a diameter 59 equal to 3.128". The inner wall of the rim is formed with a convergenee having a radius of curvature 44 equal to .OS0"
wlth an origin located a distance 80 equal ~o .057" above the base plane and lying on a circle with a diameter 60 equal to
3.102". The inner wall of the rim above the convergence is straight and essentially perpendicular to the base plane.
The countersink groove 46 is formed with a radius of cur~vature 48 equal to .050" the outer wall 49 of which merges with the inner rlm wall 50. The inner wall of the groove meets the outer wall of the groove at the crest of ~he groove 47 which lies a distance 76 equal to .150" above the base plane, and on a circle with a diameter 62 equal to 2.884l'.
The origin of radius 48 necessarily also lies on a circle with a diameter 62.
The countersink groove 46 is formed with a radius of cur~vature 48 equal to .050" the outer wall 49 of which merges with the inner rlm wall 50. The inner wall of the groove meets the outer wall of the groove at the crest of ~he groove 47 which lies a distance 76 equal to .150" above the base plane, and on a circle with a diameter 62 equal to 2.884l'.
The origin of radius 48 necessarily also lies on a circle with a diameter 62.
4 ~ 3 ~
A filet with a radius o curvature 58 equal to .035"
merges a planar panel 52 with the inner wall 50 of the countersink groove. l'he ilet has an origin, a distance 82 equal ~o .115" above the base plane and lying on a ~ircle with a diameter S4 equal ~o 2.696". The planar panel 52 has a surface which is parallel to the base plane.
~n ogee comprising a filet with a radius of curvature 53 equal to ~035" and a convergence with ~ radius of curva~ure 54 ~ equal to .035" outermerges planar panel 52 with midplanar panel 55. The origin of radius 53 is a dlstance 82 equal to .115" above base plane and lies on a circle with a diameter 66 equal to 2.210". The convergence radius 54 has its origin distance 84 equal to .069" and lies on a circle w~th a diameter 68 equal to 2.056". Planar panel 55 is parallel to the base plane.
An ogee comprising a filet with a radius of curvature 56 equal to .035" and a con~ergence with a radius of curvature 57 equal to .035" merges midplanar panel 55 with inner planar panel 58. The origin of radius 56 is a distance 86 equal to .143" abo~e the base plane and lies on a circle with a diameter 70 equal to 1.566". The origin of radius 57 is a distance 88 equal to .097" above the base plane and lies on a circle wi~h a diameter 72 equal to 1.413". Inner panel 58 is parallel to the base plane.
Figures 4 through 6 relate to tool~ng configurations and their use in manufacturing the aforementioned can body.
The can body is manufactured from precoated tin ree steel (TFS-CT) plate which has been double reduced. The steel strip has a DR9 temper with a plate weight of about 60 lbs.
1224~t~3~ 1 per base box. DR9 is a mill product specifica~ion which relates to the process by whlch the metal is cold reduced ln two stages with an annealling step between the cold working operations. The DR9 temper deno~es a plate which is hard and S which has a high tensile s~rength. The base box terminology for plate weight ls standard in the can maklng industry; it originally referred to the amount of steel in a base box of tin pla~e consisting of 112 sheets of steel each sheet sheared to 14" X 20". Today the base box refers to the amount of ste~l in 31360 square incheq whether in the form of coll or cut sheet.
The preferred method of manufacture employs ~wo presses.
In the first press steel strip is blanked in~o a disc and subsequently drawn into a shallow cup of large di~meter. In the second press the shallow cup with a planar bottom is deposited on the end of a cylindrical barrel whi h has a bore diameter substantially equal ~o the external diameter of ~he fin~shed can body. A punch wi~h an external di~meter substantially equal to the internal diameter of the finished can body enters the supported cup and pulls the cup down between the outer wall of the punch and the inner wall or bore of the barrel thereby redrawing the shallow cup lnto ~ can body of reduced ~iameter and increased height. At thls point the bottom wall of the can body is still planar. Where the lnished height of ~he can body is substantially ~reater than he cup height, it may be necessary to employ two redraw perations. This may be done by employing a single 1~4~3~) ~
multi station press as described in U.S Patent 4,262,510 or alternatlvely a series of presses may be employed with the proiling and flanging l~mited to the last press.
In accordance wlth the present inventlon the can body 20 is shown in Figure 4 after redrawing and in preparation for bo~tom profiling~ As shown in Figure 4, the bottom wall at this point is still of planar configuration, the flange 22 is formed and is captured between the top wall of the barrel 93 and ~ clamplng ring gO. It should be noted that the barrel is cushioned by suitable means, typically with a pneumatic cushion. The side wall 26 of the container body is shown captured between the cylindrical barrel 93 and the sleeve 92 o~ the punch. The nose 98 of the punch at this point has engaged the bottom wall of the can body there by forming the outer wall 42 o the peripheral rim of the container bottom.
The container is carried down by the advancing punch and barrel which operate ln cooperation. The upper profile pad 94 is shown in a retracted positlon.
The lower profile pad 96 is proximate to the advancing can body and tooling but has not at this point bePn engaged thereby~ 99 is a lif~ ou~ and clamp~ng device which ~s shown in a retracted positlon.
In Figure 5 the advancing punch and barrel have carried the can body forwArd to engage the peripheral bead 108 of the lower profile pad 96 thereby completing formation of the bot~om rim of the can body and pulling the planar bottom 43~il tightly across the crest 109 of the bead. The root 41 of the rim is shown lying between the outer rim wall 42 and ~he inner rim wall 45, and in contact with the upper surface of the lift out 99.
In Figure ~ the upper profile psd 94 which is coaxlally received within the pu~ch sleeve 92 is advanced to engage the tight planar bottom wall 23 thereby pulling the bottom wall over the crest of the perlpheral bead 108 to ~orm the countersink groove and ~o initiate the forming of an outer panel 52, a mid~anel 55 and an Inner panel 58. The advance of the punch is further increased to effect an overstriking of the bottom wall by introducing a shim 102 between the die block lO0 and the lower profile pad 96. This shim effects a .020" overstrike to accentuate the profile panels, place the panels ln tenæion and ma~e them tau~.
In Figure 6, the upper profile pads are tightly radlused to further assist in tensioning the panels of the bottom wall, thus, the peripheral bead of the lower profile pad 96 is formed with a radius of curvature .050" to form the outer bead wall 110, and the inner bead wall lll, with the outer and inner walls meeting at the crest of the bead lO9. The upper panel plate 115 is formed with corner radii 112 and 113 equal to .035"~ The plate walls 116 and 117 are substantially parallel to the axis of rotstion 11-ll and there~ore 2~ substantially perpendicular to the planar face of 115. The lower panel bead ring is formed with a radius of curvation 114 equal to .035" and perpendlcular side walls 121 and 122. The ~ 3 O
upper paneling bead ring i8 similarly formed with a radius of curvature 118 equal to .035" and with perpendicular side walls 119 and 120. The lower paneling plate which forms profile panel 58 i8 formed with 8 corner radiu~ 124 equal to .035" and with a perpendicular slde wall.
The clearance be~ween perpendicular tooling surfaces 117 and 121 and between surfaces 120 and 123 is equal to the stock thickness plus abou~ .0005" whereas the clearance between the inner wall o the perlpheral bead defined by radlus 108 and perpendicular wall 116 is about .0025".
The radial displacement between the origins of radius 113 and radius 118 i8 .322". The radical dlsplacement between the origins of radius 114 an~ 124 is .322".
Sanitary can bodies produced according to this method from TFS-CT steel double reduced to a DR9 temper, with a plate weight of only 60 lbs. per base box, have consistently resisted internal pressures of 30-32 psi wlthou~ exhibiting buckling or permanent distortion. Further; these can bodies have shown good springback retention where the internal pressure has not exceeded 30 psi~ These capabillties enable the sontainer to meet the customersl requirements of 25 psl buckle resistance and 20 psi springback retention with light weight plate despite the normal variations which may be encountered under production conditions.
Thus, it may be seen that the instant novel method has produced a high strength can body from light weight plate.
The can body has a high level of buckle resistance, good springback retentlon and may be manufactured with tooling ~L2~44~0 whlch is compatible with conventional apparatus.
While this invention has been described in relation to a 307 X 112 sanitary can for pet food it has been successfully employed for a variety of sanitary type cans including 300 X
405, 300 X408 3/4~ 301 X 106 and 307 X 200.25.
While ~he detailed disclosure and the drawings show and explain the upper profile pad 94 and the sleeve 92 as moving independently with respect to one another, that technique is used primarlly for clarity in connection with the explanation of the invention herein. Those skilled in the art will no doubt appreciate that the movement of the upper profile pad 94 and the sleeve 92 can be simultaneous in order to facilitate the simplicity of the tooling design and construction.
Likewise, other changes and modifications to the dimensions, shapes and structures can be included without departing from the overall concept set forth in the claims of this disclosure.
A filet with a radius o curvature 58 equal to .035"
merges a planar panel 52 with the inner wall 50 of the countersink groove. l'he ilet has an origin, a distance 82 equal ~o .115" above the base plane and lying on a ~ircle with a diameter S4 equal ~o 2.696". The planar panel 52 has a surface which is parallel to the base plane.
~n ogee comprising a filet with a radius of curvature 53 equal to ~035" and a convergence with ~ radius of curva~ure 54 ~ equal to .035" outermerges planar panel 52 with midplanar panel 55. The origin of radius 53 is a dlstance 82 equal to .115" above base plane and lies on a circle with a diameter 66 equal to 2.210". The convergence radius 54 has its origin distance 84 equal to .069" and lies on a circle w~th a diameter 68 equal to 2.056". Planar panel 55 is parallel to the base plane.
An ogee comprising a filet with a radius of curvature 56 equal to .035" and a con~ergence with a radius of curvature 57 equal to .035" merges midplanar panel 55 with inner planar panel 58. The origin of radius 56 is a distance 86 equal to .143" abo~e the base plane and lies on a circle with a diameter 70 equal to 1.566". The origin of radius 57 is a distance 88 equal to .097" above the base plane and lies on a circle wi~h a diameter 72 equal to 1.413". Inner panel 58 is parallel to the base plane.
Figures 4 through 6 relate to tool~ng configurations and their use in manufacturing the aforementioned can body.
The can body is manufactured from precoated tin ree steel (TFS-CT) plate which has been double reduced. The steel strip has a DR9 temper with a plate weight of about 60 lbs.
1224~t~3~ 1 per base box. DR9 is a mill product specifica~ion which relates to the process by whlch the metal is cold reduced ln two stages with an annealling step between the cold working operations. The DR9 temper deno~es a plate which is hard and S which has a high tensile s~rength. The base box terminology for plate weight ls standard in the can maklng industry; it originally referred to the amount of steel in a base box of tin pla~e consisting of 112 sheets of steel each sheet sheared to 14" X 20". Today the base box refers to the amount of ste~l in 31360 square incheq whether in the form of coll or cut sheet.
The preferred method of manufacture employs ~wo presses.
In the first press steel strip is blanked in~o a disc and subsequently drawn into a shallow cup of large di~meter. In the second press the shallow cup with a planar bottom is deposited on the end of a cylindrical barrel whi h has a bore diameter substantially equal ~o the external diameter of ~he fin~shed can body. A punch wi~h an external di~meter substantially equal to the internal diameter of the finished can body enters the supported cup and pulls the cup down between the outer wall of the punch and the inner wall or bore of the barrel thereby redrawing the shallow cup lnto ~ can body of reduced ~iameter and increased height. At thls point the bottom wall of the can body is still planar. Where the lnished height of ~he can body is substantially ~reater than he cup height, it may be necessary to employ two redraw perations. This may be done by employing a single 1~4~3~) ~
multi station press as described in U.S Patent 4,262,510 or alternatlvely a series of presses may be employed with the proiling and flanging l~mited to the last press.
In accordance wlth the present inventlon the can body 20 is shown in Figure 4 after redrawing and in preparation for bo~tom profiling~ As shown in Figure 4, the bottom wall at this point is still of planar configuration, the flange 22 is formed and is captured between the top wall of the barrel 93 and ~ clamplng ring gO. It should be noted that the barrel is cushioned by suitable means, typically with a pneumatic cushion. The side wall 26 of the container body is shown captured between the cylindrical barrel 93 and the sleeve 92 o~ the punch. The nose 98 of the punch at this point has engaged the bottom wall of the can body there by forming the outer wall 42 o the peripheral rim of the container bottom.
The container is carried down by the advancing punch and barrel which operate ln cooperation. The upper profile pad 94 is shown in a retracted positlon.
The lower profile pad 96 is proximate to the advancing can body and tooling but has not at this point bePn engaged thereby~ 99 is a lif~ ou~ and clamp~ng device which ~s shown in a retracted positlon.
In Figure 5 the advancing punch and barrel have carried the can body forwArd to engage the peripheral bead 108 of the lower profile pad 96 thereby completing formation of the bot~om rim of the can body and pulling the planar bottom 43~il tightly across the crest 109 of the bead. The root 41 of the rim is shown lying between the outer rim wall 42 and ~he inner rim wall 45, and in contact with the upper surface of the lift out 99.
In Figure ~ the upper profile psd 94 which is coaxlally received within the pu~ch sleeve 92 is advanced to engage the tight planar bottom wall 23 thereby pulling the bottom wall over the crest of the perlpheral bead 108 to ~orm the countersink groove and ~o initiate the forming of an outer panel 52, a mid~anel 55 and an Inner panel 58. The advance of the punch is further increased to effect an overstriking of the bottom wall by introducing a shim 102 between the die block lO0 and the lower profile pad 96. This shim effects a .020" overstrike to accentuate the profile panels, place the panels ln tenæion and ma~e them tau~.
In Figure 6, the upper profile pads are tightly radlused to further assist in tensioning the panels of the bottom wall, thus, the peripheral bead of the lower profile pad 96 is formed with a radius of curvature .050" to form the outer bead wall 110, and the inner bead wall lll, with the outer and inner walls meeting at the crest of the bead lO9. The upper panel plate 115 is formed with corner radii 112 and 113 equal to .035"~ The plate walls 116 and 117 are substantially parallel to the axis of rotstion 11-ll and there~ore 2~ substantially perpendicular to the planar face of 115. The lower panel bead ring is formed with a radius of curvation 114 equal to .035" and perpendlcular side walls 121 and 122. The ~ 3 O
upper paneling bead ring i8 similarly formed with a radius of curvature 118 equal to .035" and with perpendicular side walls 119 and 120. The lower paneling plate which forms profile panel 58 i8 formed with 8 corner radiu~ 124 equal to .035" and with a perpendicular slde wall.
The clearance be~ween perpendicular tooling surfaces 117 and 121 and between surfaces 120 and 123 is equal to the stock thickness plus abou~ .0005" whereas the clearance between the inner wall o the perlpheral bead defined by radlus 108 and perpendicular wall 116 is about .0025".
The radial displacement between the origins of radius 113 and radius 118 i8 .322". The radical dlsplacement between the origins of radius 114 an~ 124 is .322".
Sanitary can bodies produced according to this method from TFS-CT steel double reduced to a DR9 temper, with a plate weight of only 60 lbs. per base box, have consistently resisted internal pressures of 30-32 psi wlthou~ exhibiting buckling or permanent distortion. Further; these can bodies have shown good springback retention where the internal pressure has not exceeded 30 psi~ These capabillties enable the sontainer to meet the customersl requirements of 25 psl buckle resistance and 20 psi springback retention with light weight plate despite the normal variations which may be encountered under production conditions.
Thus, it may be seen that the instant novel method has produced a high strength can body from light weight plate.
The can body has a high level of buckle resistance, good springback retentlon and may be manufactured with tooling ~L2~44~0 whlch is compatible with conventional apparatus.
While this invention has been described in relation to a 307 X 112 sanitary can for pet food it has been successfully employed for a variety of sanitary type cans including 300 X
405, 300 X408 3/4~ 301 X 106 and 307 X 200.25.
While ~he detailed disclosure and the drawings show and explain the upper profile pad 94 and the sleeve 92 as moving independently with respect to one another, that technique is used primarlly for clarity in connection with the explanation of the invention herein. Those skilled in the art will no doubt appreciate that the movement of the upper profile pad 94 and the sleeve 92 can be simultaneous in order to facilitate the simplicity of the tooling design and construction.
Likewise, other changes and modifications to the dimensions, shapes and structures can be included without departing from the overall concept set forth in the claims of this disclosure.
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A sanitary can body of the type having a peripheral outer flange at the top end of the can body, a cylindrical side wall symmetrical about an axis of rotation and joined to said flange and a bottom wall integral with said side wall, the improvement a profiled bottom wall comprising:
a. a peripheral rim with an inwardly inclined outer rim wall and an inner rim wall the lower extremities of said inner and outer wall converging to form the root of said rim, said root being tangent to a base plane which plane is perpendicular to said axis of rotation;
b. an annular upwardly directed countersink groove, adjacent to and inwardly disposed of said rim said countersink groove being formed with a radius of curvature of .050" with a groove crest intermediate the outer wall of said groove and the inner wall of said groove.
c. an annular outer panel disposed inwardly of said countersink groove and concentric thereto said panel lying on a plane parallel to said base plane and intermediate said rim root and said groove crest and joined to said groove inner wall with a filet having a radius curvature of .035";
d. an annular midpanel disposed inwardly of said outer panel concentric and parallel thereto lying on a plane intermediate said outer panel and said groove crest and joined to said outer panel with an ogee having an outlet filet with a radius of curvature of .035" and an inner convergence with a radius of curvature of .035"; and e. an inner panel disposed inwardly of said midpanel, parallel thereto and lying on a plane intermediate said midpanel and said groove crest and joined to said midpanel with an ogee said ogee having an outer filet with a radius of curvature of .035" and an inner convergence with a radius of curvature of .035".
a. a peripheral rim with an inwardly inclined outer rim wall and an inner rim wall the lower extremities of said inner and outer wall converging to form the root of said rim, said root being tangent to a base plane which plane is perpendicular to said axis of rotation;
b. an annular upwardly directed countersink groove, adjacent to and inwardly disposed of said rim said countersink groove being formed with a radius of curvature of .050" with a groove crest intermediate the outer wall of said groove and the inner wall of said groove.
c. an annular outer panel disposed inwardly of said countersink groove and concentric thereto said panel lying on a plane parallel to said base plane and intermediate said rim root and said groove crest and joined to said groove inner wall with a filet having a radius curvature of .035";
d. an annular midpanel disposed inwardly of said outer panel concentric and parallel thereto lying on a plane intermediate said outer panel and said groove crest and joined to said outer panel with an ogee having an outlet filet with a radius of curvature of .035" and an inner convergence with a radius of curvature of .035"; and e. an inner panel disposed inwardly of said midpanel, parallel thereto and lying on a plane intermediate said midpanel and said groove crest and joined to said midpanel with an ogee said ogee having an outer filet with a radius of curvature of .035" and an inner convergence with a radius of curvature of .035".
2. A sanitary can body as recited in claim 1 wherein said bottom wall is drawn taut and placed in tension to form a stable distention resistant configuration.
3. A sanitary can body as recited in claim 2 manufactured from TFS-CT grade steel, double reduced with a DR9 temper and a plate weight of about 60 lbs. per base box.
4. A sanitary can manufactured by joining a closure to the sanitary can body as recited in claim 3 and wherein said can bottom has a buckle resistance within the range 25-32 psi and a springback retention greater than 24 psi.
5. A method of profiling the bottom wall of a sanitary can body having a side wall, a planar bottom wall integral therewith and having An open top with a peripheral flange comprising the steps of:
a. receiving said can body in cushioned barrel with said flange supported by said barrel;
b. clamping said flange to said barrel;
c. entering said can body with a cylindrical punch sleeve to engage the periphery of said bottom wall with the nose of said sleeve to thereby form the outer wall of a bottom rim;
d. advancing said punch sleeve and said cushioned barrel with said clamped can body to engage the peripheral bead of a first profile pad thereby completing formation of said bottom rim and pulling said planar bottom panel tightly across the crest of said peripheral bead;
e. advancing a second profile pad coaxially received within said sleeve to engage said tight bottom wall between said first and second profile pads thereby pulling said bottom wall over said peripheral bead to form the countersink groove in said bottom wall and to initiate the forming of an outer panel, a midpanel and an inner panel of said bottom wall;
f. overstriking said bottom wall with said second profile pad to fully set and define said countersink groove, said outer panel said midpanel, and said inner panel to tension said bottom wall and make said panels taut.
a. receiving said can body in cushioned barrel with said flange supported by said barrel;
b. clamping said flange to said barrel;
c. entering said can body with a cylindrical punch sleeve to engage the periphery of said bottom wall with the nose of said sleeve to thereby form the outer wall of a bottom rim;
d. advancing said punch sleeve and said cushioned barrel with said clamped can body to engage the peripheral bead of a first profile pad thereby completing formation of said bottom rim and pulling said planar bottom panel tightly across the crest of said peripheral bead;
e. advancing a second profile pad coaxially received within said sleeve to engage said tight bottom wall between said first and second profile pads thereby pulling said bottom wall over said peripheral bead to form the countersink groove in said bottom wall and to initiate the forming of an outer panel, a midpanel and an inner panel of said bottom wall;
f. overstriking said bottom wall with said second profile pad to fully set and define said countersink groove, said outer panel said midpanel, and said inner panel to tension said bottom wall and make said panels taut.
6. A method as recited in claim 5 wherein said tensioning of said bottom wall is facilitated by pulling the bottom wall around the tooling profile which has been radiused with a .035"
radius of curvature.
radius of curvature.
7. A method as recited in claim 2 wherein said bottom wall is pulled tight by employing a first profile pad wherein said peripheral bead has a radius of curvature of .050".
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US36984182A | 1982-04-19 | 1982-04-19 | |
| US369,841 | 1982-04-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1224430A true CA1224430A (en) | 1987-07-21 |
Family
ID=23457144
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000426062A Expired CA1224430A (en) | 1982-04-19 | 1983-04-18 | Integral end profile for a buckle resistant sanitary can and method of manufacture |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1224430A (en) |
| GB (1) | GB2119743B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9216247D0 (en) * | 1992-07-30 | 1992-09-09 | Cmb Foodcan Plc | Souffle:can ends |
| US6286705B1 (en) * | 1997-03-03 | 2001-09-11 | Abbott Laboratories | Container having tapered sidewall made from sheet material and lid to seal same |
| US7942283B2 (en) * | 2004-03-09 | 2011-05-17 | Marc Radow | Dispenser assembly |
| ES2348096T3 (en) * | 2005-02-05 | 2010-11-30 | Ball Packaging Europe Gmbh | STACKABLE FLAT BACKGROUND CAN. |
| JP4877538B2 (en) * | 2010-06-08 | 2012-02-15 | 東洋製罐株式会社 | Seamless can body |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1512490A (en) * | 1966-12-27 | 1968-02-09 | Futs Metalliques Gallay S A | Funds for metal drums |
| FR1533259A (en) * | 1967-05-09 | 1968-07-19 | Carnaud & Forges | Improvements to the crimped ends of metal cans, in particular for canned food |
| FR2137293B1 (en) * | 1971-05-18 | 1974-03-22 | Carnaud & Forges | |
| JPS5325186A (en) * | 1976-08-20 | 1978-03-08 | Daiwa Can Co Ltd | Metallic can for drink containing carbon dioxide or the like |
| ZA767130B (en) * | 1976-12-06 | 1977-10-26 | Metal Box Co Ltd | Containers |
| FR2379443A1 (en) * | 1977-02-04 | 1978-09-01 | Solvay | HOLLOW BODY IN THERMOPLASTIC MATERIAL |
| FR2382373A1 (en) * | 1977-03-02 | 1978-09-29 | Solvay | HOLLOW BODY IN THERMOPLASTIC MATERIAL |
| GB1600006A (en) * | 1977-03-26 | 1981-10-14 | Metal Box Co Ltd | Containers |
| FR2397333A2 (en) * | 1977-05-17 | 1979-02-09 | Ferembal Sa | IMPROVEMENTS TO BELLOWS FUNDS ESPECIALLY FOR TIN CANS |
-
1983
- 1983-04-07 GB GB08309411A patent/GB2119743B/en not_active Expired
- 1983-04-18 CA CA000426062A patent/CA1224430A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2119743B (en) | 1986-02-12 |
| GB2119743A (en) | 1983-11-23 |
| GB8309411D0 (en) | 1983-05-11 |
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