CA1177615A - Cup forming mandrel, method, and article - Google Patents
Cup forming mandrel, method, and articleInfo
- Publication number
- CA1177615A CA1177615A CA000434249A CA434249A CA1177615A CA 1177615 A CA1177615 A CA 1177615A CA 000434249 A CA000434249 A CA 000434249A CA 434249 A CA434249 A CA 434249A CA 1177615 A CA1177615 A CA 1177615A
- Authority
- CA
- Canada
- Prior art keywords
- end portion
- sleeve
- mandrel
- container
- radial force
- 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
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Abstract
ABSTRACT OF THE DISCLOSURE
A cup-like container is formed with a rim by mount-ing a sleeve of thermoplastic sheet material on a mandrel, holding the sleeve in position on the mandrel by exerting a first radial force outwardly against the interior of an end portion of the sleeve, and heating the end portion. The end portion is then expanded, in a radial direction by the ap-plication of a second radial force outwardly against the in-terior of the end portion and the sleeve is translated along its longitudinal axis while the expanded end portion is held fixed against an abutment ring to cause the end portion to upset, thus forming the rim.
A cup-like container is formed with a rim by mount-ing a sleeve of thermoplastic sheet material on a mandrel, holding the sleeve in position on the mandrel by exerting a first radial force outwardly against the interior of an end portion of the sleeve, and heating the end portion. The end portion is then expanded, in a radial direction by the ap-plication of a second radial force outwardly against the in-terior of the end portion and the sleeve is translated along its longitudinal axis while the expanded end portion is held fixed against an abutment ring to cause the end portion to upset, thus forming the rim.
Description
117761~
This is a division of Patent Application Serial No. 377,954, filed May 20, 1981.
The present invention relates generally to containers such as cups and the like manufactured of plastic material. In par1:icular, the present invention relates to the manufacture of one-piece foam sheet material cups. For some 1:ime cups have been manufactured of expanded polystyrene beads by the well-known steam chest process. This method of cup manufacture has the inherent disadvantage in that each container, if so desired, must be individu<~lly decorated by an elaborate and time consuming process. It was then discovered that oriented foam sheet mater:ial could be produced and decorated on one side similar to and by techniques used in the paper decorating industry. The decorated foam sheet material was then C11t into rectangular shaped blanks which were then roLled into cylinders containing a single side seam. The cylinders were then placed on a mandrel with a portion of the cylinder protruding beyond the mandrel. The mandrel and the plastic foam sheet stock cylinder which it contained were then sub-jected to heat which in turn caused the foam sheet cylinder to shrink to the external configuration of the mandrel. A separate bottom closure has been used with the foam sheet cylinder to produce a two-piece container.
Also, a one-piece cup has been produced by merely pres-sing the extra material, that protrudes beyond the mandrel into a bottom structure. After the containers, such as cups for beverages, were produced by the above described method, the cup, were then subjected to a 1 17761 ~
separate rimming process which produced the familiar bead on the rim of the cup.
The present invention provides a method of form-ing a container rim,`includlng the steps of mounting a sleeve of thermoplastic sheet material on a mandrel, holding the sleeve in position on the mandrel by exerting a first radial force outwardly against the interior of an end portion of the sleeve, heating the end portion of the container where it is being held by the first radial force, expanding the end portion in a radial direction by the application of a second radial force outwardly against the interior of the end portion, transla-ting the sleeve along its longitudinal axis while holding the expanded end portion fixed against an abutment ring, and causing the end portion to upset, thus forming a rim on the container.
Preferably, the method includes the step of continu-ing the heating of the end portion during the upsetting of the end portion.
The invention will be more readily understood from the following description of a preferred embodiment shown in the drawings, in which:
Fig. 1 is a sectional view of an apparatus embody-ing the present invention.
Fig. 2 is a sectional view taken along the line 2-
This is a division of Patent Application Serial No. 377,954, filed May 20, 1981.
The present invention relates generally to containers such as cups and the like manufactured of plastic material. In par1:icular, the present invention relates to the manufacture of one-piece foam sheet material cups. For some 1:ime cups have been manufactured of expanded polystyrene beads by the well-known steam chest process. This method of cup manufacture has the inherent disadvantage in that each container, if so desired, must be individu<~lly decorated by an elaborate and time consuming process. It was then discovered that oriented foam sheet mater:ial could be produced and decorated on one side similar to and by techniques used in the paper decorating industry. The decorated foam sheet material was then C11t into rectangular shaped blanks which were then roLled into cylinders containing a single side seam. The cylinders were then placed on a mandrel with a portion of the cylinder protruding beyond the mandrel. The mandrel and the plastic foam sheet stock cylinder which it contained were then sub-jected to heat which in turn caused the foam sheet cylinder to shrink to the external configuration of the mandrel. A separate bottom closure has been used with the foam sheet cylinder to produce a two-piece container.
Also, a one-piece cup has been produced by merely pres-sing the extra material, that protrudes beyond the mandrel into a bottom structure. After the containers, such as cups for beverages, were produced by the above described method, the cup, were then subjected to a 1 17761 ~
separate rimming process which produced the familiar bead on the rim of the cup.
The present invention provides a method of form-ing a container rim,`includlng the steps of mounting a sleeve of thermoplastic sheet material on a mandrel, holding the sleeve in position on the mandrel by exerting a first radial force outwardly against the interior of an end portion of the sleeve, heating the end portion of the container where it is being held by the first radial force, expanding the end portion in a radial direction by the application of a second radial force outwardly against the interior of the end portion, transla-ting the sleeve along its longitudinal axis while holding the expanded end portion fixed against an abutment ring, and causing the end portion to upset, thus forming a rim on the container.
Preferably, the method includes the step of continu-ing the heating of the end portion during the upsetting of the end portion.
The invention will be more readily understood from the following description of a preferred embodiment shown in the drawings, in which:
Fig. 1 is a sectional view of an apparatus embody-ing the present invention.
Fig. 2 is a sectional view taken along the line 2-
2 of Fig. 1.
Fig. 3 is an enlarged sectional view of that por-tion represented by numeral 96 of Fig. 1.
Fig. 4 is a view similar to Fig. 3 which shows the segments in an outward position.
Fig. 5 is a view similar to Fig. 4 that shows the downward movement of the mandrel sleeve.
Fi~. 6 is a view similar to Fig. 5 wherein the contalner bead is completely formed.
THE PREFERRED EMBODIMENT
The apparatus for the manufacture o~ a container rrom a foam sleeve is show.n generally at l0 in Fig. l. A
base 12 is provided for the support o~ the mandrel 14 and its associated mechanism. The base mechanism can be, for example, a drum assembly o:r conveyor system that permits mobility cf the mandrel assembly. Since the container will be partialiy formed by the shrlnkage of the foam material, lt is desirable that the m;~ndrel pass through a heated zone such as an oven. A support column 16 is cantilevered normal to base plate 12 and as shown for convenience in an upright position in Fig. 1. Support column-16 contains a M anged head 18 at its free end and a reduced diameter 20 at its threaded end 22. A hollow cylindrically shaped support post 24 contalns a centrally pos1tioned bore 26 through which the reduced diameter 20 of support column l~ is inserted. As nut 28 ls tlghtened, support post 24 is clamped firmly against the top surface 30 o~ base 12. m us, base 12, support column 16 and hollow support post 24 are in fixed relation-ship wlth one another and do not move as does the remainder of mandrel 14 and lts associated parts which are described below.
Mandrel 14 is adapted for movement along support column 16 as described in detail. Mandrel 14 comprises a cylindrical section 32 which is supported at both ends. The top end 34 coacts with end plate 36 and bottom plate 38.
The top end plate 36 contalns an end closure that is recessed l 177B 1 ~
as at 40. This particular recess provides room ror the formation of the bottom structure Or a cup. Ir the bottom o~ the cup or container is not recessed, lt will not always maintain its stability when lt slts on a surrace that ls not exactly planar. A tubular ~;ectlon 42 is ~ormed as an inte-gral part o~ top end plate '36. Tubular sectlon 42 ls generally concentrlc with the cylindrical section 32 of mandrel 14, although the ext;erlor Or sectlon 32 may ln some instances have a slight taper to facllltate the removal Or COmpleted containers from the mandrel. me lnterior bottom end 44 cGntains an lnternally threaded bore 46 that is zdapted ~cr engagement wlth simllar threads on slide column 4. Thus it is possible to not only disengage cylindrical sectlon 32 from the remaining portion of mandrel 14, but it is also an added advantage to be able to ~uickly change the cyllndrlcal sectlon 32 to a longer or shorter plece wlthout entlrely dismantllng or replacing the overall assembly 10.
Sllde column 48 contalns a centrally positloned through bore 50 that has an internal diameter of greater extent than the outer dlameter of support column 16. A top slide bearlng 52 ls press ritted lnto the cen.trally posltioned bore 50 o~
sllde column 48. A similar bottom sllde bearing 54 is also press fitted into the lower section of slide column 48. Thus it can be observed that bearings 52 and 54 permit slide column 48 to move up and down while being guided by the outer surface of support column 16. ~lide column 48 ls biased in an upward position by the influence o~ compression sprlng 56 which is positioned around support column 16 so that it abutts against and extends from the lower end Or slide bearing 54 to the top inside surface 58 of hollow support post 24.
lsoal " ~
117761~
The low~r end o~ sllde column 48 contains a radlally out-wardly extending ~lange 60. A cyllndrlcal spacer bushing 62 ls pressed over the exteric,r Or sllde column 48 and ln abutt-ing relatlonship with the t;op surface o~ outwardly extending rlange 60. A cam disc 64 is posltloned in clrcum~erentlally slidlng en8agement with the outer sur~ace o~ spacer bushing 62 m e cam disc also has its bottom surrace restlng on the top surface Or outwardly extendlng ~lange 60. A handle 66 ls attached to cam dlsc 64 so that cam disc 64 can be rotated in either dlrection about ;pacer bushing 62. A series o~ cam pins 68 æ~e circumferentia:ly spaced around cam disc 64. The cam pins ~8 protrude in an upward direction and coact with c~m fol'owing tracks 70 whLch are positioned in radially outwardly movable segments 72. It can be determined from the description set rorth supra that slide column 48 moves up and down along support column :l6 and also supports movable seg-ments 72 which are adapted for movement in a radial direction Attention is once again directed to hollow support post 24. A cut-out 74 is provided so that handle 66 can move rreely up and down with mandrel 14. The free cylindrical end Or hollow support post 24 contains an internally cylindrical cavity 76 that is bounded on its interior side by air distri-bution ring 78. Air distribution ring 78 not only forms the lnterior wall of cavity 76, but it also provides the means for air egress ~rom cavity 76. Small air holes 80 permit a continuous flow o~ radially inwardly directed cooling air to flow from cavity 76. An a:ir infeed line 82 provides the air supply to cylindrical cavity 76. The radially inward cylin-drical extent of air distributian rlng 78 contains two concentrically positioned ba~le rings 84 and 86. The spaces 117761~
provlded between and ad~acent to ba~fle rln~s 84 and 86 create a turbulent ~low of air just arter the air has exlted air holes 80. It is to be understood that the size and spacing o~ holes 80 can be varied so as to provlde equal heati-ng around the arcuate~ extent o~ air distributlon ring 78.
An abutment rin~; 88 is supported on a ledge formed on the interior of hollow support post 24. The abutment ring 88 is ~ree to float ln a radial direction through the extent provlded for by gap 90. The vertical freedom Or abutment r ng 88 is restrained by the bottom of air distri-bution rin2 78.
Fig. 2 is a sec1;ional view taken along the lines 2-2 of Fig. l. Fig. 2 shows the movable segments 72 and the arcuate cam following tracks 70 that are formed into the lower bottom hal~ of each segment. Cam pins 68 are shown in engagement wlth cam following tracks 70. The cam disc 64 which supports cam pins 68 is shown beneath the movable seg-ments 72. The bottom pla1;e 38 contains a plurality of radially oriented slide bars 92 which protrude in a downward direction from the lower ~;urface of bottom plate 38. Sllde bar 92 can be best seen in Fig. l. Each movable segment 72 contains a radially milled groove 94 in its top surface that coacts with slide bar 92. The position of groove 94 is shown in Fig. 2 although :Lt ls apparent that groove 94 is in a position above section ;2-2. As each moYable segment 72 is cammed radially outward and inward under the influence of cam disc 64 and its attached cam pins 68, the movable seg-ments 72 all keep their alignment and move only in a radial 1 177~1 5 dlrection as desired.
Fig. 3 ls an enlarged fra~mentary view of that area shown in circle 96 on Fig. 1. The top sldewall Or an inverted ~oam plastlc contalner 98 ls shown in posltlon over the mandrel 14 and bottom plate 38. The movable segments 72, described heretofore, are in their radially inward position, thus their cylindrical outer surface 100 is rlush wlth the outer edge surface 102 of ~)ottom plate 38.
The leading or top end 104 of container 98 is ~ositioned so that it over]aps the outer surface of movable segment 72. Care is exerclsed to assure that edge 104 does not exter.d lower than the t;op surface 106 of abutment ring 88.
As the top end 104 of contalner 98 is positloned on mandrel 14, lt ls sub~ected to heated alr exiting from air holes 80.
The heat softened end 104 ls then ready for radlal expansion.
Flg. 4 ls a view similar to Fig. 3 except that movable segments 72 have been moved to their radially outer-most position, thus causin~; end 104 of container 98 to lncrease in diameter. At this time, hot air is be~ng directed by baffle rings 84 and 86 toward end 104 and its immedlate area. The end 104, in its radially expanded position, is in abutment with the top surface 106 of abutment ring 88.
Fig. 5 is a view similar to Fig. 4 except that the entlre mandrel 14 assembly has begun its downward movement, thus compressing compresslcn spring 56 which ls depicted ln Fig. 1. Since the end 104 of container 98 is in abutment with the top surface o~ abutment ring 88, it begins to bend or curl outwardly and back against the sidewall of container " ll77615 98. Of course, as previou-;ly polnt~d out, abutment ring 88 does not move down with mandrel 14 slnce lt ls rlgidly supported in a vertical dlrectlon by hollow support post 24.
Flg. 6 is a vlew slmilar to Flg, 5, however, the mandrel 14 has moved to its downwardmost position. As man-drel 14 moves downward, the end 104 of container 98 is completely folded back aga'inst the sidewall Or the container.
At thls time the hot air from alr holes 80 ls reduced so that lts impingement against the sldewall Or the contalner 98 will not have an adverse effect.
A.ter the rim has been formed on the contalner 98 as descrlbed and shown in ~lg. 6, the contalner is ready ~or removal from the mandrel 14. Referring once again to Fig. 1, an air source 108 is shown in base 12. The air source 108 ls in turn coupled to a concentrlcally relief cut 110 in the reduced dlameter sectlon 20 of support column 16. The alr that reaches relief cut 110 vla air source 108 communicates with alr passage 112 by way of air duct 114. Alr passage 112 ls rormed concentrically around support column 16 and is positloned between top sllde bearlng 52 and bottom sllde bearlng 54. Air duct 114 ls posltloned wlthln the central extent Or support column 16. Apertures are placed ln the sldes Or threaded bore 46, thus providing rurther communi-catlon for the alr as it progresses from air passage 112 to the space 116 between the lnner wall of cylindrical section 32 and the exterlor Or tubular section 42. Air egress holes 118 are positioned circumferentially around the perlpheral extent of the top end plate 36 Or mandrel 14. m us it can be observed that air from air æource 108 can be utili~ed to 3o create a force against the lnternal surface of a cup bottom~
. _ ~!
`I 177615 thus e~ectlng complet~d cup rrom the conrin~ment o~ mandrel 14 once the rim has been completely formed.
In the utili~atlon Or the contalner formlng apparatus heretorore described, a cyllndrical sleeve of oriented thermoplastic heat; shrlnkable plastic materlal is positioned on the mandrel and the leading edge Or the sleeve ls positioned as previously descrlbed and shown ln the drawlngs. A portlon of the cylindrlcal sleeve extends beyond the er.d of the mandrel and is subjected to a carerully controlled and dlrected heat source such as hot alr. The free end O~a the sleeve shrinks into a small elongate tube that is but a fraction Or the sleeve's origlnal dlameter.
The sleeve ~s, while ln the heat softened condltlon, pressed against the bottom of the mandrel to rorm an end closure on the container.
The mandrel is made to telesco~e upon itself when a force is applied to ~he free end. Thus, it becomes evident that the rim of the container is formed at the same time that the bottom of the container is pressed.
Thus lt becomes apparent that the present invention contemplates not only the apparatus for rorming a contalner, but also the method simultaneously forming the bottom Or a one-plece container and also the rim Or the container.
m e container thus produced by the present apparatus and`method has a rim that folds back upon itself, thus pro-viding a reinrorcement for the reception Or a closure. The rim is essentially two concentric cylindrical sections. me _.9_ .... . ~
ll77615 rirst seotlon ls that cy~ drlcal portion Or the sldewall near the top Or the container and the second section ls the cyllndrical section of slightly larger diameter positioned next to the first section. The two contiguous sectlons are, of course, coupled ~ogether at the ~ery top of the rim.
Fig. 3 is an enlarged sectional view of that por-tion represented by numeral 96 of Fig. 1.
Fig. 4 is a view similar to Fig. 3 which shows the segments in an outward position.
Fig. 5 is a view similar to Fig. 4 that shows the downward movement of the mandrel sleeve.
Fi~. 6 is a view similar to Fig. 5 wherein the contalner bead is completely formed.
THE PREFERRED EMBODIMENT
The apparatus for the manufacture o~ a container rrom a foam sleeve is show.n generally at l0 in Fig. l. A
base 12 is provided for the support o~ the mandrel 14 and its associated mechanism. The base mechanism can be, for example, a drum assembly o:r conveyor system that permits mobility cf the mandrel assembly. Since the container will be partialiy formed by the shrlnkage of the foam material, lt is desirable that the m;~ndrel pass through a heated zone such as an oven. A support column 16 is cantilevered normal to base plate 12 and as shown for convenience in an upright position in Fig. 1. Support column-16 contains a M anged head 18 at its free end and a reduced diameter 20 at its threaded end 22. A hollow cylindrically shaped support post 24 contalns a centrally pos1tioned bore 26 through which the reduced diameter 20 of support column l~ is inserted. As nut 28 ls tlghtened, support post 24 is clamped firmly against the top surface 30 o~ base 12. m us, base 12, support column 16 and hollow support post 24 are in fixed relation-ship wlth one another and do not move as does the remainder of mandrel 14 and lts associated parts which are described below.
Mandrel 14 is adapted for movement along support column 16 as described in detail. Mandrel 14 comprises a cylindrical section 32 which is supported at both ends. The top end 34 coacts with end plate 36 and bottom plate 38.
The top end plate 36 contalns an end closure that is recessed l 177B 1 ~
as at 40. This particular recess provides room ror the formation of the bottom structure Or a cup. Ir the bottom o~ the cup or container is not recessed, lt will not always maintain its stability when lt slts on a surrace that ls not exactly planar. A tubular ~;ectlon 42 is ~ormed as an inte-gral part o~ top end plate '36. Tubular sectlon 42 ls generally concentrlc with the cylindrical section 32 of mandrel 14, although the ext;erlor Or sectlon 32 may ln some instances have a slight taper to facllltate the removal Or COmpleted containers from the mandrel. me lnterior bottom end 44 cGntains an lnternally threaded bore 46 that is zdapted ~cr engagement wlth simllar threads on slide column 4. Thus it is possible to not only disengage cylindrical sectlon 32 from the remaining portion of mandrel 14, but it is also an added advantage to be able to ~uickly change the cyllndrlcal sectlon 32 to a longer or shorter plece wlthout entlrely dismantllng or replacing the overall assembly 10.
Sllde column 48 contalns a centrally positloned through bore 50 that has an internal diameter of greater extent than the outer dlameter of support column 16. A top slide bearlng 52 ls press ritted lnto the cen.trally posltioned bore 50 o~
sllde column 48. A similar bottom sllde bearing 54 is also press fitted into the lower section of slide column 48. Thus it can be observed that bearings 52 and 54 permit slide column 48 to move up and down while being guided by the outer surface of support column 16. ~lide column 48 ls biased in an upward position by the influence o~ compression sprlng 56 which is positioned around support column 16 so that it abutts against and extends from the lower end Or slide bearing 54 to the top inside surface 58 of hollow support post 24.
lsoal " ~
117761~
The low~r end o~ sllde column 48 contains a radlally out-wardly extending ~lange 60. A cyllndrlcal spacer bushing 62 ls pressed over the exteric,r Or sllde column 48 and ln abutt-ing relatlonship with the t;op surface o~ outwardly extending rlange 60. A cam disc 64 is posltloned in clrcum~erentlally slidlng en8agement with the outer sur~ace o~ spacer bushing 62 m e cam disc also has its bottom surrace restlng on the top surface Or outwardly extendlng ~lange 60. A handle 66 ls attached to cam dlsc 64 so that cam disc 64 can be rotated in either dlrection about ;pacer bushing 62. A series o~ cam pins 68 æ~e circumferentia:ly spaced around cam disc 64. The cam pins ~8 protrude in an upward direction and coact with c~m fol'owing tracks 70 whLch are positioned in radially outwardly movable segments 72. It can be determined from the description set rorth supra that slide column 48 moves up and down along support column :l6 and also supports movable seg-ments 72 which are adapted for movement in a radial direction Attention is once again directed to hollow support post 24. A cut-out 74 is provided so that handle 66 can move rreely up and down with mandrel 14. The free cylindrical end Or hollow support post 24 contains an internally cylindrical cavity 76 that is bounded on its interior side by air distri-bution ring 78. Air distribution ring 78 not only forms the lnterior wall of cavity 76, but it also provides the means for air egress ~rom cavity 76. Small air holes 80 permit a continuous flow o~ radially inwardly directed cooling air to flow from cavity 76. An a:ir infeed line 82 provides the air supply to cylindrical cavity 76. The radially inward cylin-drical extent of air distributian rlng 78 contains two concentrically positioned ba~le rings 84 and 86. The spaces 117761~
provlded between and ad~acent to ba~fle rln~s 84 and 86 create a turbulent ~low of air just arter the air has exlted air holes 80. It is to be understood that the size and spacing o~ holes 80 can be varied so as to provlde equal heati-ng around the arcuate~ extent o~ air distributlon ring 78.
An abutment rin~; 88 is supported on a ledge formed on the interior of hollow support post 24. The abutment ring 88 is ~ree to float ln a radial direction through the extent provlded for by gap 90. The vertical freedom Or abutment r ng 88 is restrained by the bottom of air distri-bution rin2 78.
Fig. 2 is a sec1;ional view taken along the lines 2-2 of Fig. l. Fig. 2 shows the movable segments 72 and the arcuate cam following tracks 70 that are formed into the lower bottom hal~ of each segment. Cam pins 68 are shown in engagement wlth cam following tracks 70. The cam disc 64 which supports cam pins 68 is shown beneath the movable seg-ments 72. The bottom pla1;e 38 contains a plurality of radially oriented slide bars 92 which protrude in a downward direction from the lower ~;urface of bottom plate 38. Sllde bar 92 can be best seen in Fig. l. Each movable segment 72 contains a radially milled groove 94 in its top surface that coacts with slide bar 92. The position of groove 94 is shown in Fig. 2 although :Lt ls apparent that groove 94 is in a position above section ;2-2. As each moYable segment 72 is cammed radially outward and inward under the influence of cam disc 64 and its attached cam pins 68, the movable seg-ments 72 all keep their alignment and move only in a radial 1 177~1 5 dlrection as desired.
Fig. 3 ls an enlarged fra~mentary view of that area shown in circle 96 on Fig. 1. The top sldewall Or an inverted ~oam plastlc contalner 98 ls shown in posltlon over the mandrel 14 and bottom plate 38. The movable segments 72, described heretofore, are in their radially inward position, thus their cylindrical outer surface 100 is rlush wlth the outer edge surface 102 of ~)ottom plate 38.
The leading or top end 104 of container 98 is ~ositioned so that it over]aps the outer surface of movable segment 72. Care is exerclsed to assure that edge 104 does not exter.d lower than the t;op surface 106 of abutment ring 88.
As the top end 104 of contalner 98 is positloned on mandrel 14, lt ls sub~ected to heated alr exiting from air holes 80.
The heat softened end 104 ls then ready for radlal expansion.
Flg. 4 ls a view similar to Fig. 3 except that movable segments 72 have been moved to their radially outer-most position, thus causin~; end 104 of container 98 to lncrease in diameter. At this time, hot air is be~ng directed by baffle rings 84 and 86 toward end 104 and its immedlate area. The end 104, in its radially expanded position, is in abutment with the top surface 106 of abutment ring 88.
Fig. 5 is a view similar to Fig. 4 except that the entlre mandrel 14 assembly has begun its downward movement, thus compressing compresslcn spring 56 which ls depicted ln Fig. 1. Since the end 104 of container 98 is in abutment with the top surface o~ abutment ring 88, it begins to bend or curl outwardly and back against the sidewall of container " ll77615 98. Of course, as previou-;ly polnt~d out, abutment ring 88 does not move down with mandrel 14 slnce lt ls rlgidly supported in a vertical dlrectlon by hollow support post 24.
Flg. 6 is a vlew slmilar to Flg, 5, however, the mandrel 14 has moved to its downwardmost position. As man-drel 14 moves downward, the end 104 of container 98 is completely folded back aga'inst the sidewall Or the container.
At thls time the hot air from alr holes 80 ls reduced so that lts impingement against the sldewall Or the contalner 98 will not have an adverse effect.
A.ter the rim has been formed on the contalner 98 as descrlbed and shown in ~lg. 6, the contalner is ready ~or removal from the mandrel 14. Referring once again to Fig. 1, an air source 108 is shown in base 12. The air source 108 ls in turn coupled to a concentrlcally relief cut 110 in the reduced dlameter sectlon 20 of support column 16. The alr that reaches relief cut 110 vla air source 108 communicates with alr passage 112 by way of air duct 114. Alr passage 112 ls rormed concentrically around support column 16 and is positloned between top sllde bearlng 52 and bottom sllde bearlng 54. Air duct 114 ls posltloned wlthln the central extent Or support column 16. Apertures are placed ln the sldes Or threaded bore 46, thus providing rurther communi-catlon for the alr as it progresses from air passage 112 to the space 116 between the lnner wall of cylindrical section 32 and the exterlor Or tubular section 42. Air egress holes 118 are positioned circumferentially around the perlpheral extent of the top end plate 36 Or mandrel 14. m us it can be observed that air from air æource 108 can be utili~ed to 3o create a force against the lnternal surface of a cup bottom~
. _ ~!
`I 177615 thus e~ectlng complet~d cup rrom the conrin~ment o~ mandrel 14 once the rim has been completely formed.
In the utili~atlon Or the contalner formlng apparatus heretorore described, a cyllndrical sleeve of oriented thermoplastic heat; shrlnkable plastic materlal is positioned on the mandrel and the leading edge Or the sleeve ls positioned as previously descrlbed and shown ln the drawlngs. A portlon of the cylindrlcal sleeve extends beyond the er.d of the mandrel and is subjected to a carerully controlled and dlrected heat source such as hot alr. The free end O~a the sleeve shrinks into a small elongate tube that is but a fraction Or the sleeve's origlnal dlameter.
The sleeve ~s, while ln the heat softened condltlon, pressed against the bottom of the mandrel to rorm an end closure on the container.
The mandrel is made to telesco~e upon itself when a force is applied to ~he free end. Thus, it becomes evident that the rim of the container is formed at the same time that the bottom of the container is pressed.
Thus lt becomes apparent that the present invention contemplates not only the apparatus for rorming a contalner, but also the method simultaneously forming the bottom Or a one-plece container and also the rim Or the container.
m e container thus produced by the present apparatus and`method has a rim that folds back upon itself, thus pro-viding a reinrorcement for the reception Or a closure. The rim is essentially two concentric cylindrical sections. me _.9_ .... . ~
ll77615 rirst seotlon ls that cy~ drlcal portion Or the sldewall near the top Or the container and the second section ls the cyllndrical section of slightly larger diameter positioned next to the first section. The two contiguous sectlons are, of course, coupled ~ogether at the ~ery top of the rim.
Claims (5)
1. The method of forming a container rim, including the steps of:
mounting a sleeve of thermoplastic sheet material on a mandrel, holding said sleeve in position on said mandrel by exerting a first radial force outwardly against the interior of an end portion of said sleeve, heating the end portion of the container where it is being held by said first radial force, expanding the end portion in a radial direction by the application of a second radial force outwardly against the interior of the end portion, translating the sleeve along its longitudinal axis while holding the expanded end portion fixed against an abut-ment ring, and causing the end portion to upset, thus forming a rim on the container.
mounting a sleeve of thermoplastic sheet material on a mandrel, holding said sleeve in position on said mandrel by exerting a first radial force outwardly against the interior of an end portion of said sleeve, heating the end portion of the container where it is being held by said first radial force, expanding the end portion in a radial direction by the application of a second radial force outwardly against the interior of the end portion, translating the sleeve along its longitudinal axis while holding the expanded end portion fixed against an abut-ment ring, and causing the end portion to upset, thus forming a rim on the container.
2. The method as claimed in claim 1 including the step of:
continuing the heating of the end portion during the upsetting of the end portion.
continuing the heating of the end portion during the upsetting of the end portion.
3. A method of forming a cup-like container including the steps of:
mounting a sleeve of thermoplastic sheet material on a mandrel, holding said sleeve in position on said mandrel by exerting a first radial force outwardly against the interior of an end portion of said sleeve, heating the end portion of the container where it is being held by said first radial force, expanding the end portion in a radial direction by the application of a second radial force outwardly against the interior of the end portion, translating the sleeve along its longitudinal axis while holding the expanded end portion fixed against an abut-ment ring, and causing the end portion to upset, thus forming a rim on the container, heating an opposite end portion of the sleeve to cause it to soften and shrink into partial conformity with the ex-ternal contour of said mandrel, and pressing the heat softened opposite end portion of the sleeve into a bottom closure for said container.
mounting a sleeve of thermoplastic sheet material on a mandrel, holding said sleeve in position on said mandrel by exerting a first radial force outwardly against the interior of an end portion of said sleeve, heating the end portion of the container where it is being held by said first radial force, expanding the end portion in a radial direction by the application of a second radial force outwardly against the interior of the end portion, translating the sleeve along its longitudinal axis while holding the expanded end portion fixed against an abut-ment ring, and causing the end portion to upset, thus forming a rim on the container, heating an opposite end portion of the sleeve to cause it to soften and shrink into partial conformity with the ex-ternal contour of said mandrel, and pressing the heat softened opposite end portion of the sleeve into a bottom closure for said container.
4. The method of forming a cup-like container inclu-ding the steps of:
mounting a sleeve of thermoplastic sheet material on a mandrel, holding said sleeve in position on said mandrel by exerting a first radial force outwardly against the interior of an end portion of said sleeve, heating the end portion of the container where it is being held by said first radial force, expanding the end portion in a radial direction by the application of a second radial force outwardly against the interior of the end portion, translating the sleeve along its longitudinal axis while holding the expanded end portion fixed against an abut-ment ring, and causing the end portion to upset, thus forming a rim on the container, the sleeve being a cylindrical sleeve having at least one side seam of overlapped configuration on said mandrel so that an opposite end portion of the cylindrical sleeve pro-trudes beyond an end of said mandrel, the sleeve being heated to cause it to soften and shrink into partial conformity with the external contour of said mandrel, and in which the pro-truding opposite end portion of said sleeve is pressed against a bottom forming portion of said mandrel to form a bottom closure for said container, the rim being formed simultaneously with said pressing.
mounting a sleeve of thermoplastic sheet material on a mandrel, holding said sleeve in position on said mandrel by exerting a first radial force outwardly against the interior of an end portion of said sleeve, heating the end portion of the container where it is being held by said first radial force, expanding the end portion in a radial direction by the application of a second radial force outwardly against the interior of the end portion, translating the sleeve along its longitudinal axis while holding the expanded end portion fixed against an abut-ment ring, and causing the end portion to upset, thus forming a rim on the container, the sleeve being a cylindrical sleeve having at least one side seam of overlapped configuration on said mandrel so that an opposite end portion of the cylindrical sleeve pro-trudes beyond an end of said mandrel, the sleeve being heated to cause it to soften and shrink into partial conformity with the external contour of said mandrel, and in which the pro-truding opposite end portion of said sleeve is pressed against a bottom forming portion of said mandrel to form a bottom closure for said container, the rim being formed simultaneously with said pressing.
5. The method as claimed in claim 3 or 4 including continuing the heating of the first-mentioned end portion during the upsetting thereof.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000434249A CA1177615A (en) | 1981-05-20 | 1983-08-09 | Cup forming mandrel, method, and article |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000377954A CA1168010A (en) | 1981-05-20 | 1981-05-20 | Cup forming mandrel, method, and article |
| CA000434249A CA1177615A (en) | 1981-05-20 | 1983-08-09 | Cup forming mandrel, method, and article |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000434249A Division CA1177615A (en) | 1981-05-20 | 1983-08-09 | Cup forming mandrel, method, and article |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000434249A Division CA1177615A (en) | 1981-05-20 | 1983-08-09 | Cup forming mandrel, method, and article |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1177615A true CA1177615A (en) | 1984-11-13 |
Family
ID=25669328
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000434249A Expired CA1177615A (en) | 1981-05-20 | 1983-08-09 | Cup forming mandrel, method, and article |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1177615A (en) |
-
1983
- 1983-08-09 CA CA000434249A patent/CA1177615A/en not_active Expired
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