Note: Descriptions are shown in the official language in which they were submitted.
l~J~''1'7~1~
This invention rela-tes to containers; to componentq
for such containers in the form of cylindrical one-piece
metal can bodie~ having an open end terminating in an outwarclly
directed peripheral flange mexging with a circumferentially-
extending neck portion (the can body being hereinafter referred
to as a "can body of the kind hereinbefore specified"); to ,
methods of forming said neck and flange in a can body of the
kind hereinbefore specified; and to apparatus for forming the
said peripheral flange and neck portion.
~ he purpose of the peripheral flange is usually to
provide an element to which a can end is secured after the can
has been filled, this securing being done by deforming the end
flange of the can body together with a peripheral flange of
the can end so as to form a double seam. ~he neck enables the
flange, and therefore the can end, to be of smaller diameter
, ~han i~ there were no neck; usually the radial depth of the
neok is such that the double seam has an external diameter
no greater than that of the cylindrical side wall. In some
types of metal container, such as those having realosable
lids of the so-called ~"lever" or "pry-off"~type, the member
seamed on to the end,of the can body is usually a ring in which
, the lid engages~
The e~d neck may serve another purpose, which is to
provide a aonvenient mean~ whereby a c~rrier can engage the
container; such carriers are designed t~ hold a plurality
. . . . . .
of containers and may be of~ for example~ paperboard o~ a
~lexible pla~tic~ material. ~he type of carrier which engages ~
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-the neck of a container of the kind with which ~hi~ specification
i~ concerned usuallg has a horizontal web in which there are
a plurality of holes, the periphery of each hole engaging
below the above-mentioned container double end ~eam so a~ to
support the container wholly or partly thereby. Where the
container body is necked, the neck can be 90 ~haped as to
provide ~ome measure of support and/or restraint ~or the
carrier web around the hole in the latter, and to assist in
locking the container to the web until the user wishes to pull
it awag from the carrier. ~ F
Various methods have been proposed for forming an
end neck a~d flange on a Qne~iece can body. Some methods
involve moulding the neck and/or the flange bg means of
circumferentially extending moulds. Other methods in~olve
rolling or spinning the neck and/or ~lange, using an external
~pinnin~ roil oo-operating with an internal member within the
aan bodg. In thase ~atter methods a~ known to us~ the can
bodg i9 supported rigidly by an internal mandrel or the like;
,the internal member may be a spinning roll or it may be the
mandrel which support~ the can body. In one suah method the neck
and flange are formed simultaneously in a can body supported
internally and rigidlg by a mandrel or chuck of an e~paning
type7 the neok and flange profile being formed by external
spinning rolls oo-operating with this mandrel.
In another method, the can bodg is supported internallg
by An an~il and endwise by a ~p~nnihg pilotj the neck and flange
beinglfo~med by a profiled, external spinning roll w~ich de~orms
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'781
the can body into a groove formed on the pilot and anvil,
the roll being moved axially of the can body.
In all these previously proposed methods, the final
profile of the neck and flange is determined by the profiles
of the tool elements used for forming them, in that the tool
elements (i.e., moulds, spinning rolls, mandrels, anvils, etc.)
are provided with working surfaces profiled to conform with the
required shape of the neck and/or the ~lange, and the metal
of the can body is deformed into conformity with these profiles.
It is thus necessary, if a different shape is required, to
change the tools so as to provide differently profiled tool
elements.
A method such as that mentioned above, in which an
expanding mandrel is used, enables end flanges and neck por-
tions to be produced reliably and economically even on can
bodies made in khe thinner and harder metals currently in
favour, in particular double-reducedjplate which is usually tin-
plate, but which may, for example, be mild steel or blackplate
suitably treated but not necessarily plated with another metal.
The present invention is also especially suitable for use with
these thinner and harder materials.
According to the invention, in a first aspect thereo~,
a method is provided ~or forming a peripheral end flange at an
open end of a cylindrical metal can body and a neck merging with
said flange, wherein said methoa comprises supporting the can
body in axial compression whilst deforming the can body, in
free space, adjacent said open end by applying an axial
shortening force thereto simultaneously with an inward radial
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~Lo~,4t~
~orce~
Preferably, the method includes the steps of: ~
supporting the can body endwise in axial compression between ~ .
a bottom support element, coaxially engaging the bottom of the
can body and defining a main axis, and an end support member
engaging a terminal edge of the body coaxially at said open
end, with a pilot element extending coaxially into said body
through the end support member, and effecting relative rota-
tion about said main axis between, on the one hand, said can
body, bottom support member, end support member and pilot
element and, on the other hand, an external forming member
whilst effecting relative radial movement between said can
body and said fo.rming member, relative axial movement between
said can body and forming element, and relative axial movement
between said end support member and bottom support element,
whereby to apply an axial shortening force to the body and to
maintain said endwise.supportl a constant axial spacing being
maintained between a circumferential first tool edge of the
pilot element and a second tool edge of the forming member,
whereby at least part of said neck and flange are formed in
free space by said second tool edge deforming the can body
about said first tool edge as fulcrum. :.
It is implicit in the method of the invention in its
preferred form as above defined, that the profiles or shapes of
the neck portion and end flange in the finished can body are'
produced by deforming the metal of the workpiece progres3ively
along the length of the end portion; in effect, the second tool :`:
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~o~
edge works its way along the sidewall end portion, ~orming
the required profile therein with the first tool ed~e engaging
the inside of the end portion to provide a fulcrum point for
the deformation effected by the second tool edge.
It will be realized that a feature of the method of
the invention as above defined is that, by contrast with
previously proposed methods mentioned hereinbefore, the profile
or shape of the neck portion and flange does not rely on the
provision of one or more tool surfaces formed with the re~uired
profile, because in the present invention the shape does not
have to be formed by bringing the material of the workpiece,
e.g., by moulding, rolling or spinning, into intimate engage-
ment and therefore conformity with such profiled tool surface
or surfaces, but is formed instead, in free space. This
does not, however, exclude the possibility, within the scope of
the invention, of some portion of the profile being in con-
formity with a profile of a tool edge. In general, however,
by the present invention, the material is wrought in a manner
such that it deforms to a shape determined partly by the
characteristics of the axial shortening force and radial force,
and therefore of the various relative motions, to which the
workpiece is su~]ected, i.e., the shape of the neck portion and
end flange, for a workpiece of a particular metallic material
having a given thickness, sidewall length and diameter,
predetermined by suitable choice of velocity variation and
relative timing of the radial moti~n between the second tool
edge and the workpiece in relation to the axial motion between
the workpiece and the first and second tool edges.
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~0&~7~31
It will be realized that in its preferred form as
above defined, the method o~ the invention, at any instant
during the process, provides contact in only three places
between the end portion of the workpiece and the tooling used
for forming the neck portion and flange, viz. at the terminal
edge, to provide radial restraint for the edge and to guide
it in its a~ial motion; at a single point on the inside surface
of the end portion, by the first tool edge, and at a single ?
point on the outside surface of the end portion by the second
tool edge. It follows that, by varying the characteristics
of the relative motions for a given workpiece, the shape or
profile to be given to the neck and flange can be changed at
will. In practice a wide variety of such shapes can be pro-
duced without any need to change parts of the tooling as would
- be necessary where the required profile depends on tooling
parts having particular profiles~ ~
Preferably, the first tool edge is kept stationary -
and the second tool edge is moved radially with respect to the
workpiece, the workpiece being moved axially with respect to
the first and second tool edges in a direction such that the
axial distance between the latter and the terminal edge of the
workpiece decreases to zeroO .
According to the invention, in a second aspect thereof,
apparatus is provided for forming a peripheral end flange at an
open end of a cylindrical metal can body and a neck merging with
said flange, said apparatus comprising opposed first and second
axial support means defining a main axis and being adapted for
supporting respectively a bottom end and an open end of said ;
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78~
body in axial compression, and inward radial force applying
means adjacent said second axial support means, said first and
second support means being arranged for axial movement relative
to each other such as to shorten the axial distance between
them, and said inward radial force applying means being movable
radially with respect to said main axis.
Preferably the apparatus comprises: a bottom support
element for coaxially engaging the bottom of the can body and
defining a main axis; an end support member coaxially opposed to
the bottom support eIement, for engaging a terminal edge o~ the
can body at said open end, a pilot member extending through the
end support member towards said bottom support element and
having a circumferential first tool edge, and an external
forming member having a second tool edge facing towards the said
main axis and disposed at a constant axial spacing from said
first tool edge, said end support member and bottom support
element being arranged for axial movement relative to each other ~ `
whereby to apply an axial shortening force to the can body, and
said end support member being arranged for axial movement past
the pilot element, and said forming member and end support mem-
ber being arranged for radial motion relativQ to each other.
Preferably the bottom support element comprises a lift
pad for ~upporting the end of the workpiece opposite said open
end, and the end support member is a limit ring adapted to engage
the terminal edge axially and to restrain it radi`ally, said lift
pad and limit ring being capable of axial movement independently
of each other.
The pilot member is typically a mandrel or chuc~ `
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having a circular edge to give contact substantially in a single
plane transver~e to the workpiece axis between said edge (being
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1~)8~78~L
sald first tool edge), a~d the workpis~e.
The ~orming member iB pre~erably a roller, rot~tabl~
about its own axi8 and having a simple circumferenti~l edge
profile defining said second tool edge. ~his latter edge may b~
~uch as to give contact substantially in a ~ingle plane, trans-
verse to the workpiece axis, at any in~tant between ~aid ~econd
tool edge and the end portion of the workpieoe. ~here may b~ two
or more of said ~eco~d tool elements.
The invention al~o include~ within it8 8CQp0 a metal
can body of the kind herei~before 6pecified, made b~ a method
according to said fi~t asp~ct o~ the i~vention; and also
includes within it~ ~cope a ¢ontainer compri~ing a ~aid can
body a~d having an end clo~ure member ~eamed to the peripheral
: flange ther~of.
Various embodiments of the invention will now be
desaribed, by way of example, with re~erence to the aacompanying
drawin~s, in whiah:-
~igure ~ is a diagrammati¢ ~ectional ele~atio~ `
showing part Or~ a can bod~ i~ a~so¢~ation with element~ of
apparatu~ in a simple embodlment of the invention;
~ igure~ 2 to 6 show re~pectively ~ive stages in thefo~m~tion of a ~eck portion and psripheral end flange of a can ~:
body, illustrating diagrammatically an example of a method
according to the i~vention~
~igure 7 i~ a ~implified sec~ional elovatio~ showing .
part~ of appar~tu~ in a further embodimant of the inven~ion; and
~ i~;ure~38 to 11 are ~ectional acrap elev~tiol~s ~howin~; :
~our example~ o~ ~cck portion~ and e~d flan~ee whioh may be
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~ormed in the practice of the invention~
Referrin~ to Figure 1, apparatu~ for forming a
peripheral flange 10 and a neck portion 1~ of ~ ca~ body 12
include~ end ~upport mea~s (her~inafter described) for ~upporting
coaxiRll~ therewith, and i~ ~xial cQmpre~ion~ a hollow metal work-
piece 13 in the form of a cylindrical metal can body. ~he l~tter
i~ of the ki~d compri~ing a thin c~ drical ~eamle~s ~idewall 14
havin~ an end portio~ 15 (~hown in chain-dotted lines); the
end portion 15 ha~ a terminal edge 16 defining a~ open end 17
of the workpieoe~ ~he workpicce 13 includes an integral
bottom wall (not ~hown in Fi~ure 1) which may be of any known
shape ~uch as the reverse-dom~d type~ part of which oan be ~een
at 18 in ~igur~ 2. ~he upper or open end of the cylindrical :
~idewall 14 o~ the workpie~e 13 is in thi~ ~xample ali~htl~
flared in the e~d portion 15 to define a ~mall initial flan~e 19.
~h~ workpiece 13 i~ preferably o~ double-reduced tinplate or
chemiaally-treated mild steel or bla¢kplate.
~ he ~upport means comprisea an end support member in bhe
~orm o~ a limit ring 20 having at its lower end ~n an~ular reb~te
21:~ox e~ga~ing th~ terminal edgo 16 And the fl~nge 10, and R
bot~om support m~mber in the rorm of a lift pad 22, not ~hown
in ~igure 1 but provided a~ in the arrangement Q~ ~igure 2 to
support the bottom wall 18 o~ the wor~piec~ ~rom below. Th~
lift p~d 22 and bhe limit ring 20 are arranged for controlled
moveme~t in the di~ection of the axis 23 o~ the workpie¢e 13
independently of each other in a manner whi¢h will become
oloar~r ~rom the d~criptio~ herei~aftor with referenc~ to
~igur~ 2 to 6.
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~ he apparatus al~o includes a pilot member in the form
of the m~ndrel or chuck 24 exte~di~g throu~h the limit ring 20,
and withi~ the hollow workpiece 13, tow~rds the lift pad 22.
In this ex~mple the chuck 24 consist~ of a simple di~c h~vin~ a
first peripheral tool edge 25 which i~ slightly r~diu~ed; and a
form~ng member i~ the form of a nsckin~ roller 26 having ~ ~econd
tool edge in the form of a simple radiused circum~erQ~tial edge ,~
profile 27, at a constant axial ~paci~g from the tool edge 25
~he ne¢king roller 26 i~ rotatable about it~ ow~ axis 28 in known
mann0r, a~d is also arranged for relative radial motion between
it~elf and the main axi~ 23 which is co~mo~ to the workpicce 13,
~he limit ri~g 20 and the li~t pad~22. This relativa motion i~
obtained b~ ~ontrolled radial movement of the roller 26 as
i~dicated by the arrow 29.
The limit ring 20 and the lift pad, the workpiece 13
a~d chu¢k 24 are rotatable together about the axi~ 23.
~ ha operation of theapparatus will be more clearly
under~tood by referen¢e to ~igure~ 2 to 6. ~he workpi~c~ 13
i~ ~upported o~ the lift pad 22 a~d raised thereby ~igure 2) `'
unkil th~ torminal ed~e 16 of tho workpiace e~gage~ in the limit ~-
ri~g rebate 21 as seen i~ ~igure 30 ~he limit rin~ 20 at ~hi~ ~
: ~tage i9 at its uppe~mo~t positio~, and the workpiece 13 i~ ~
out of co~tact with the chu¢k 24.
~ho workpiece 13 iB ~OW suppQrtad co~xiall~, in axial ~
compre~sio~, b~ t~e lift pad 22 and limit ring 20; the latter ~;
provides radial restraint for th~ terminal edge 16. It will
al~o bo seen that the chuck 24 lies internally of the workpiece 13
and that the sidewall 14 o~ the latter li~8 between the chuck 24
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and the necking roller 26 out~de the workpiece.
With the lift pad 22, limit ring 20, chuck ~4 and work-
pieoe 13 rotatin~ as ~ unit (as indica~ed b~ the arrow 31 i.n
~igure ~)~ the lift p~d 22 and limlt ring 20 are moved downwards
a~ indicated by the vertical arrows in Figure~ 4 to 6, B0 moving
the workpiece 13 down with them relati~e to the tool edg~ 25
and 27.
During thi~ axi~l motion the necking roller 26, ;~
rotating continuously about it~ own axis, i~ moved radially. `;~ ~ I
These axial (ver~ical) and radial (horizontal) movements of ~ ~
the workpiece 13 and roller 26 respecti~ely are tim6d 80 that ~ ::
a point 32 (~igure ~) on the roller ~dge surfAce 27 first mak~s
contact with the sidewall 14 of the workpiece 13 ~u~t where
the lower extremity 33 (Figure 6) of the neck ~ortion 11 i~ to bo.
As tha vertical downward movement o~ the workpieoe ~1 ;
conti~ues, ~urth~r horizontal mo~eme~t of tho necking roller 26
¢au~es the ~etal of the workpiece end portion 15 to bo d~formed
(~igur~ 4) in free 6pao0 by co-operation bstween the tool edgo 27 :~
of the roller and the tool edge 25 of the ¢huck, the odg~ 25
engaging th~ internaI surface o~ the wo~kpieoe in a common radial
(vertical) pl~ne with th~ point o~ contact 32 betweQn the edge 27
and the outer aurfa¢e of the workpiece. ~he tool edge 25 ~erve~
.,~
a~ a fulcrum for the controlled deformation o~ the metal in ~ree
space, to form a frusto-co~ical neo~ profile ~ f th~ radial
movement of the necki~ rollsr,26 i~ now ~topped whilst ~xial
motion of the workpieoe 13 conti~ues, a ¢ylindrical ne¢k profilo 35
will b~ ~ormed (~igure 5) above the profile 34.
igure!'5 reprefie~t~ the e~d of the forming oper~tion,
12~
iLo~ 7~L
the limit ring 20 havin~; reached its lowe~t position ~nd the
whole of the end portion 15 of th~ workpiece 13 having b~en fo~mcd
into the neck portion 11 and periph0ral end flang~ 10, the top
~urface of the latter b~ing defined by tho po~ition of th~
internal tool edge 25.
It will be ~een from th~ foregoing that th~ limit ring
20 ~erv~ not only to re8trair~ the termi.al edge 16 in the rAdi~l
dir~otion ~nd apply ~n ax~al ehoxt~nin~ force thsr~to, but al~o
to guide it i~ its axial motion ~o as to keep the still-unde~ormed:
part of tho workpiec~ (viz. ~6 in ~igure 4) ~teady in lt~ initial ~:~
~tate. It will be appreciated that, in order to achi~ve this, th~ :
provislo~ of the initial ~lange 19 i~ do3irablo, though not
.
~cossaril~ required in all cases~
Whilst the lift pad 22 move~ steadily downwArd~
through a di~tancc X during tho forming operation, tho limit
ring 20 mov~ downwards through a dist~nce Y which i~ ~rcat0r
th~n the dist~nce X. ~h~ velocity charact~ristic of the
mo~em~t of the limit rin~ 20 ie d~t~rmi~ed by th~ rate at
which metal i~ dra ~ away axiall~ there~rom, and will vary
aceordi~g to tho ~eck and flange profil~ required. It will
b~ under~tood that this variation can be predetermined~ and
clo~el~ controlled by any o~e of a number of known teohniquoe
~or the control o~ tools. In the ~ame wa~ tho predetermined
characteri~tlc~ of ~he rAdlal motion o~ tho neckin~ roller 26 :`;
can bo clo~oly conkrolled. It i8 of ¢our~e possible to provide
a chara¢t~ri~tic motio~ Or the lift pad 22 ~uch that it doe~ :
~ot movo a~ ~ub~tantially ¢on~ta~t volocity. By arranging
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t78~
the vertic~ d horizontal movemen~ respecti~el~ of the lifb
pad 22 and Iimit ring 20 and Or the roller 26 to have p~e-
determined ~elocity chara¢t~ri~bic~ ~nd by timing the~e
movemente~in a predetermi~ed mannér relative to ea¢h other, ' .
any de~ired neck and flange profile can be o~tained
In this connectlon it is to be noted that the c~uc~ 24, ;~
limit ring 20 ~nd necking roller 26 con~titut~ ~ tool set
which may readil~ be fitted a~ a ~imple modification to Q ~ :~
~tandard machi~e'o~ a known type ~or necking can bodies by
spinning, or for seAmin~ end member~ to c~n bodiea. Such
machine inolude8 the li~t pad 22, together with drive~ ~or
rotating the seaming roll and ~or moving it radlally; ~or
rotati~g the chuck ~nd li~t pad; *or moving the li~t pad up
a~d down; ~d ~or moving the chuck up and down. Since suah
machlne~ are well known in the art, they do not need to be,
describea in de~ail hero; it will readily be appreciat0d
~, that the ~rive for moving the chuck up ~nd down may be ooupled ~'
instead to the limitring 20 ~o a~ to effeot verti¢al movement
o~ the latter instead of the chuck 24. Coupli~g these ~ariou~ ~:
drives together 30 a~ to control the chara¢teristios a~ di~
auBsed above may be performed in any Xnown manner. ~There mRy~ .
~or example, be provided three timed cam~ ¢onbrollin~ re~pecbi~el~ ' :
the vertical mo~ementa Or the li~t pad and o~ the limit ring,
and the ra~ial or horizontal movement o~ the neokin~ roller, ,~
, all the aam~ being dri~en ~rom a ¢onstant-~peed,motor. Al~ernati~el~
a ~lmple ele¢tri¢al ¢on~rol ~ystem o~ ~he numerical, magnetic,
bape or !~pe~-boardll types m~y be pro~ided to oontrol the various
drive~ 'the~e ~y~tem~ ha~e the ad~antage.or bei~g ~er~ readil~
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re-programm~ble to ~ new profile af~ nac~c and fl~nge.
~ t will be apprecia~ed tha~ di~ou~sed ~rlier
h0rain, it i~ the charaateristi¢~ o~ the various relative
motio~s of the tool elements 20, 22, 25, 27, together with
tho inherent chara¢teri~ti¢~ of the material and dimension~
of the workpiece 13 it~elf, that determine the ~inal pro~ile
Or the neck portion 11 and end fl~nge 10. ~he wor~piece ~.
makes no ¢ontact wibh the chu~k 24 except at the tool edge 25
alth~ugh the formi~g o~ the r~diused portion 37 joining
the flange 10 to t~e c~lindriaal upper part 35 of the neok
p;ortion 11 is in this example assi~ted by the provision o~ the
r~diused tool edge 27 of the necking rollar 26.
~ igure ~ show~ the limit ring 20 returned bo it~
upper po~ition ~nd the ~ecking roller 26 bo i~ diseng~ged posibion,
whilst the lift pad 22 de~¢ends to enable the ~ini~hed oan
body 12 to be removedO
Re~errin~ ~ow bo ~i~ure 7, a ~onven~ional ~pin neaking
or ca~ e~d se~ming machine, haYing the various drives discussed
hereinabove, has a pair of arm~ 70 each adapted to aarry ~
spin~ing or ne¢kin~ roller 71. A neaXing head ~ase member 72
which i~ rotababl~ by a ~ubul~r spinnin~ or neaking spindle 73
(tha member 72 ~n~ spindle 73 being indicated by ohain-dot~ed :~
lines), has a n~aki~B and rl~ing bool 74 ~eaured t~ere~io. ! ;
~hs tool 74 i8 adapted to the mothod de~cribod abo~e with roforence
to Fi~ur~s 1 to 6 ~d comprises e~sentially a ring 75, ~ecurod ~o
tho member 7~ by ahollow nut 76; a c~uck 77 ~ocur~d bym~a~ not ~hown
toth~ riag75; a~d a limit ring 78 whiah i~ mountod coaxially around
~nd for axialmovemen~with respect to tho ri~g,75 a~d ohuck 77. :~
, ' " ' , ' ' ~' '. ' . . -
~478~ :
~he limit ring 78 i~ s~cured by a nut 80 ~o a ~ertical actu-
ating rod 81 which i~ movable (by suitable conventional mean~
not shown) axially through the member 72 a~d ring 75~ ~he
limit ring 78 ~8 constr~l~ed against rotation relative to the
ring 75 b~ webs 82 of the lattar engaging slots (not ~hown)
in the limit ring, but i8 rot~table with the actuating rod 81,
which extends up through the necking ~pindle 73. Thu~ the
whole tool 74, with the base member 72, i~ rotatable by the
~ecking 3pindl~ ?3~ but the limit ring 78 i8 a1BO movable
axi~lly by the actuating rod 81, which gi~es ~ull positi~e
co~tro} Or the movemenb of the limit ring 78. ~he lift pad 22
i8 ~upported o~ a base mem~er 83 by aompression springs 79.
~he base member 83 is movable up and down a~ e~p~a.ined herein-
be~ore wit~ xe~crenae to ~igures 2 to 6. ~he springs 79 serve
to pre-load the workpieae against the limit ring 78 by an amount
~u¢h a~ to indu¢e a fri¢tio~ tor~ue greater than the friational
torque i~duced by resi~tance o~ th~ workpiece to the ~eaking
operation. ;~
Operation oS the apparatus, compri0ing ths maahine
having the ~ecking:tool 74 ~nd rollers 71 of ~iguro 7, i~
ge~erAlly as ln the embod~ment de~cribed already with referenco
to ~igure~ 1 to 6. ~he use o~ two neoking rollers i9 pre-
~erred.
Re~err~ng ~o Figures 8 to 1~, the~e show ~our onl~ out
of m~ny po~sibl~ pro~ s of ~eck portions and end flange which
may b~ obtained by method~ and ~pparatus such a~ thos~ des¢ribed
~bove. A ~ifth su¢h profile is that shown in ~igure 6. In the
pro~ile ~how~ i~ Figure 8, the ~ec~ portion ~o~si~ts o~ ~
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cyli~drical portio~ 85 ~oined to the main part o~ the c~n
body sidewall 14 by a generally-radial portion 86. ~he out-
side diameter of t~e end flange 87 is ~ub~tanti~lly e~ual to
that of the sidewall 14.
~ he profile shown in Figure 9 enables an end clo~ure
member of ~ub~tantially smaller diameter than that o~ the ~ide-
wall 14 to be secured to the ca~ body by mean~ o~ the peripheral
end ~lange 90, the latter being joined to the ~idewall 14 ~::
through ~ relatively long frusto-conical ~eck portio~ 91.
~ igure 10 ~hows a more conventio~al pro~ile in which
a peripheral.end ~la~e 100 is a continuat1o~of a neck 101
havi~ a C-shaped cro~s-seation.
~ inallg, ~igure 11 illu~trate~ one example of a pro-
! ~ile in whio~ the neck portion oomprise~ more bha~ o~e ne¢k 110,
111, ~oined by a circum~erential bead ~12. , 5
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