Note: Descriptions are shown in the official language in which they were submitted.
~:113879~ :
Tllis is a division of copending application serial
no. 238,370, which was filed on 27 October 1975.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates, broadly speaking, to ~-
; apparatus for the multiple production of elongated product
such as wire. More specifically, this invention relates to
dies of particular design in which billet material, which
may be of indefinite leng-th, may be deformed to produce, -
; simultaneously, a plurali-ty of elongated products such as -
wire.
2. Description of the _rior ~rt
Simultaneous production of multiple wires from
the deformation of billet material is known to those familiar
with this art. ;
U.S. Patent, 3,394,579 (19H8) to Hall et al.
l discloses method and apparatus for extruding a plurality of - -~
;~ ~products simultaneously. In one embodiment, a single billet
is extruded through a die having plural apertures. In
another embodiment, a plurality of billets is simultaneously
extruded through respective apertures in a die having plural ;
apertures.
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; U.S. Patents 2,050,298 (1936) and 2,077,682 (1937)
both to Everett disclose assembling a plurality of discrete
billets in a bundle, placing the bundle in a metalli¢ sheath,
; packing the sheath around the bundle with a pulverulent or a --
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plastic material which functions as a separating medium ~ ;
between the billets, drawing the sheath and -the bundle - ~ -~
.
enclosed thereby through a series of dies, seriatim, to
reduce the sheath and -the enclosed bundle, and thereafter
removing the drawn sheath by chemical or electrolytic means
or by stripping the drawn sheath from the wires formed by the
drawn billets. ~
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i~33879~ ;
' . U. S. Patent, 3,540,114 (1970) to Roberts et al. ~'
discloses assembling a plurality of wires in a bundle,
placing the bundle in a sheathl applying a thin film of :.'
lubricant to the bundle, drawing the sheath and bundle
through a die to reduce the individual wires to fine filaments,
and then unwrapping or chemically etching the drawn sheath
''i~ to remove it from the filaments.
'.J The subject matter of this application represents
a further and subsequent development based on prior die
~` 10 designs ac.tually reduced to practice and disclosed in a '~
,~': copending application by Glenn L. Schmehl filed concurrently ~;
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i:,: herewith and entitled "Multiple Aperture Die."
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:. Summary of_the Invention ' ~: :
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'~'. : An object of this invention is to provide an .~ r '
' improved die for the simultaneous extrusion therethr~ough of
a plurality of w1res from billet material.
; ' : In accordance with one aspect of the present inventlon, .~ ~:
there is provided a die comprising: a die body having an entrance .~
" : ~ : :
'i ~ end; a plurality of dle aperures extending through said die
body; said'die apertures being arranged in the form of groups, ' .:
'.',: :: :~: each group comprislng a plurality of die.ap~ertures; a plurality
-. of flared mouths, each flared mouth being associated with one '~
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~ of said groups and opening toward the entrance end of said die ;'
"': body; one of said groups ls centered on the longitudinal axis ~.-;' .
'~;' of said die body, the others of said groups being radially spaced ,'.';.' :
~'~ around the sald centrally positioned groups.
In accordance with another aspect of the present ~''
,, invention there is provided a die comprlsing: a die body having
' an lnlet end and an outlet end; a first group of a plurality of
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die apertures extending through said die body, said group having
an entrance end and an exit end and centered on the longitudinal
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~387~8
axis of said die body; a flrst conical mouth extending from
the inlet end of said die body to the entrance end of said
flræt group, said first conical mouth opening from the entrance
end of said first group toward the inlet end of said die body;
a plurallty of second groups of die apertures, each of said
second groups comprising a plurality of die apertures and ;
having an entrance end and an exit end, said second groups of ~ ~
die apertures being radlally spaced around said first group ' :
of die apertures; a plurality of second conical mouths, each
second conical mouth being assoclated wlth one of said second `~
groups o~ die apertures, each second mouth extending from the
entrance end of its respective second group and intersecting .
the first conical mouth, said second conical mouths openlng ~`.. ~.
'~ :forwardly from the entrance end of its respective second group.
Br ef Description of t'he'Dr'awin~s '~
.....
~ ~: The prssent invention taken in conJunction with the
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~ invention described in copending Canadian patent application .
.'~;;:~ serial no. 238,370, filed on 27 October 1975 wi}l be described .
in detail.hereinbelow w~th the aid of the accompanying drawings
in which like numerals represent like parts in the several views;
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FIG. 1 rep.resents a medial longitudinal
~: section through one embodiment of the improved die;
FIG~ 2 represents a view in elsvation of the
entrance end of the improved die of FIG. l; ~:
FIG. 3 represents a partial medial longitudinal
section through the improved die of FIG. 1, showing in
phantom outline a rotary tool applied to a die aperture ~ :~
. to form ths mouth thereof;
FIG. 4 represents a medial longitudinal section
throu~h one form of extrusion apparatus incorporat1ng an
improved die, showing the plurality of elongated products
produced s1multaneously thereby;
FIG. 5 represents a view in elevation of the .
entrance end of an alternate embodiment of improved die; .,.-~
and
FIG. 6 represents a medial longitudinal section
~ of the die of FIG. 5, taken along the line 6-6 of FIG. 5.
.~: DE5CRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2, die 1 is
.,~ 20 seen as comprising a conical~mouth 2 at the apex of
'~ ~ which is provided a first die aperture 3 extending
, ,,~ - . ,
;~ through the said die 1 and communicating with passageway
,~ 4 at the rear end of the di~ 1. A plurality of secand
die ap~rtures 5 is formed through the conical mouth 2
~'s
- adjacent the entrance end 6 of the die 1, the said
second die apertures 5 being radially equispaced around
the die 1 as shown particularly in FI~. 2. Each of the ~ ~
second die apertures 5 is provided at its inlet end with - , :
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387~
a bevelled entry 7 arranged asymmetrically relative to ;~-
the longitudinal axis of the said se~cond die aperture 5
and extending toward the first die aperture 3. More ;i~
~ specifically, a line joinging the longitudinal axes of ~;
:~ the first die aperture 3 and a second die aperture 5 will .:
bisect the bevelled entry 7 of the said second die .
~; aperture 5. The included angle ~ at the intersection of
the bevelled entry 7 and the conical mouth 2 for each of
the second die apertures 5, as shown in FIGS. 1 and 3,
.10 advantageously will lie in the approximate range of .
45-50, although the invention is useful with other -~
values of ~. Each second die aperture 5 communicates
with a passageway $ at the rear end of the die l.
FIG. 3 shows a preferred method for~forming ~:
bevelled entries 7 at the inlet ends of second die .
apertures 5. At the location of each desired~second die
aperture 5 a cylindrlcal hole 9 is bored through, ... :~
as:indicated partially in dotted outline. Therea~fter, a ~
rotary tapered cutting tool 10, shown in phantom outline - :
: 20 ln the figure, is advanced into the cylindrical hole 9,
with one slde of the rotating tapered cutting~edge
parallel to the outer peripheral edge of the cylindrical
~hole 9, and with the longitudinal axis of the cutting
tool 10 parallel to a line extending between the longitudinal
,,,
axes of the first die aperture 3 and the cylindrical hole 9 :~
thereby completing the formation of the second die
aper.ture 5.
: It has been found that with the specific
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arrangement hereinabove described, a billet of material 11,
coated with die lubricating material such as castor oil,
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beeswax or polyethyle~e wax, when advanced into the mouth 2 -
of die 1 as in a hydrostatic extrusion process, will be : ~ ~
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evenly distributed among all of the said die apertures 3 and
5, so that each of the said die apertures 3 and 5 will receive
billet material at an equal rate~ and will produce extruded;~
product such as wire 12 at the same rate as the other die ~ ~-
apertures 3 and 5.
Die 1 has been shown with eight second die apertures
5, spiaced 45 apart. It will be understood that die 1 may have
as few as two such second die apertures 5 or more than eight
such second die apertures 5, radially equispaced around a first ~ -
die iaperture 3.
Die 1 may be used to particular advantage in
hydrostatic extrusion apparatus of the type disclosed in
U.S. Patent 3,740,985 (l973? . although it is capable of use
.
in other types of extrusion apparatuis. The said hydrostatic
extrusion apparatus will be briefly described hereinbelow
to aid in understanding the present invention.
U. S.~PateDt 3,740,985 discloses coating the ;~
elongated surface of~billet material with a shear transmitcing
medium which~may, fo~r example, be beeswax or polyethylens
~wax, and exerting through the shear transmitting medIum
a~frictional or viscous drag force along the elongated
surface~of the bil~l~et material~;thereby to advance the billet
:: , : : :~. :
;~ material through a die to produce extruded product. -
The shear transmitting medium desirably has
- high viscosity and shear strength, is capabIe of lubricating
the die, provides good wetting action on the biliet
material, and has minimal viscosity variation with respect
to pressure, temperature and shearing rate. ;~
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~ The means which exerts, through the shear
transmitting medium, viscous drag force along the elongated ~.
surface of -the billet material comprises trains of gripping .:
element segments, each train being contin~ously propelled by
pinion gears around a separate endless path, all of the ~ .
trains of gripping element segments meeting along one length
of travel from a first station upstream of a die to a second ~.
. station downstream of the die and cooperating along said .
common length of travel to form a continuously moving train `: :
10 of centrally apertured.gripping elements moving toward the
die. The inner peripheries of the said apertures engaging
~ the outer surface of the coating of shear transmitting ^
: med.ium on the billet material generate shear forces in the ~:
'! said medium which shear forces produce a frictional or
viscous drag force along the elongated surface of the billet
material to build up axial stress in the billet materlal and
.
~: advance the billet material through the die. A pressure
:~ cylinder surrounds the centrally ape~tured gripping elements : :
~;; upstream of the die and exerts a normal pressure gradlent on .~ ;
,! ~ 20 said gripping elements increasing toward the.die, whereby a
: normal stress gradient is built up in the billet material . . ~.
, increasing toward the die. These axial and normal stresses .~.
stress the billet material far above its yield strength and
increase its ductility, or capacity for deformation without
~ . .
~ fracture.
Specific details of the extrusion apparatus, .
. insofar as they do not relate to multiple extrusion and die
design, are not part of the present disclosure. Reference
should be made to U.S. Patent 3,740,985 if information on ~.
such details is desired.
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~ ~3879~
: The use of die 1 i5 illustrated in FIG. 4. ::
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Die 1 is supported in die stem 13 in the manner
disclosed in U.S~ Patent 3,740,985, the said die stem 13
~: having apertures extendiny therethrough in registry with .
apertures 4 and 8 of die 1. . ~
Billet 11, coated with shear transmitting medium ~ :
such as beeswax or polyethylene wax, is advanced to and
extruded through die 1 by means of gripping element . ~ -
A~ segments 14 propelled toward and past the die 1 by pinion .
10 gears (not shown) engaging teeth 15 on the exterior surfaces ;~
of the said gripping element segments 14, in the manner
taught in U.S. Patent 3,740,985. The gripping element
::segments 14 cooperating as a train of gripping elements `:~
constitute a pressure chamber surrounding the billet 11
snd exert,~through the coating of shear transmitting
: :medium, a frictional or viscous drag.force along the
surface of the billet ll thereby advancing the said ..
billet 11 sgainst dle l and through clie apertures 3 and 5
therein. : : : .
~: 20: ~ It will be understood that, in the manner ~ .
taught in U.S. Patent 3,740,985 the gripping elements
are surirounded.upstream of die 1 by a pressure cylinder
~: (not shown) whereby a normal pressure gradient i.ncreasing
~ toward die 1 and indicated diagrammatically by arrows of ~ ;
. increasing length in FIG. 4, is applied to the billet 11.
In the foregoing manner, axial and normal stress .;
~ gradients, increasing toward die 1 to a value above the ~-
: yield strength of the material of billet 11, are built
up in the billet 11 as the said billet is advanced, by
frictional or viscous drag force along its surface,
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3~37't338 ~;
toward and into die 1 and through die apertures 3 and 5
to produce simultaneously a plurality of extruded wires 12. `
FIGS. 5 and 6 show another embodiment of a
multiple extrusion die 16 having a 1ared mouth 17 extending
from the upstream or entrance end 18 of the said die 16 back
to a first multiple aperture grouping 19 within die 16 and -~
centered on the longitudinal axis thereof. The first ~ ~
multiple aperture grouping 19 is surrounded by several ,~ -
radially equispaced second multiple aperture groupIngs 20, `~ ~ ~
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; 10 each of which latter has a coni'cal mouth 21 at its entrance
~ end communicating with the flared mouth 17 through a conical
.~ ~ transitional opening 22.
..
The first multiple aperture grouping 19 comprises ;~
a central die aperture 23 to which the flared mouth 17 serves
'~ as a converging entry~ Each of.. the second multiple aperture
groupings~20 comprises a central die ape~.ture 23 to which the
conical mouth 21 serves as a converglng entry. The central
die apertures 23 of the first and second multiple aperture
groupings 19 and 20, respectively, are surrounded by several ;~
radially equispaced peripheral die apertures 24, the said
die apertures 23 and 24 extending through the body of the die -
16 to the downstream or exit end 25 thereof. Each periphçral
~die aperture 24 has a bevelled entry 26 extending around that
h~f of said die aperture 24 adjacent its respective central
die aperture 23. As seen particularly in FIG. 5, bevelled s ~
entries 26 are maximum dimension on the lines joining the `~ .
: ~ .
centers of die apertures 23 and 24. The central die ~
,~ :
~ apertures 23 are located on the longitudinal axis of the die ~
. .
16 t for the first multiple aperture grouping 19, and on the
longitudinal axes of the conical mouths 21, for the second
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multiple aperture groupings 20. The entrances to all o the
central die apertures 23 lie substantially on the same
transvexse plane through the die 16. The angles ~ and ~, as '.~:~
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show~ in FIG. 6, advantageously wlll be within the approximate
range of 45 -50, although the lnventlon is useful with other `.
values of ~ and ~
Advantageously, dle 16 may be employed in apparatus
of the type shown in U. S. Patent 3,740,985 in the same manner ~`
as die 1 shown in FIG. 4, .
The particular configuration of die 16 results in
an even distribution of billet material among all the first
and second multiple aperture groupings 19 and 20, and among
10 . all of the die apertures 23 and 24 in each of the first and :
second multiple aperture groupings 19 and 20. This even .
distribution of billet material to all the multiple aperture .i~
groupings 19 and 20 and to all of the die apertures 23 and 24
ln said multiple aperture groupings l9 and 20, provides for
., simultaneous extrusion at substantially equal velocities of .
multiple wires 12 of uniform quality.
Di~es l and 16~hereinabove disclosed have bsen
~: described in association with extrusion apparatus of the `
type~shown in U. 5, Patent 3,740,985. It should be
~:~: 20 ~understood ~hat these dies are capable of use in other types , :~ :
of apparatus whereby billet material may be operated upon to
produce simultaneously plural products. .`'. -~
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