Note: Descriptions are shown in the official language in which they were submitted.
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~ackground of the Invention
(1) Field of the Invention
This invention relates to extrusion presses, and more particularly
to die transfer mechanisms on extrusion presses.
(2) Description of Prior Art
An extrusion press is utili~ed to force A heated metal slug or
billet through a shaped orifice called a die stack. The die stack is
mounted in a carrier which may in turn be supported on a horizontal
track or gibs fixed to a massive vertically arranged platen. The die
is aligned with a passageway or egress hole in the plate or platen
lO which provides reinforcement thereagainst, while permitting the metal
to be forced and extruded therethrough. It is necessary to change
the die from time to time to permit changes in the extrusion pattern
or to replace a worn die. Several methods have been proposed in
the art and are shown in U.S. Patents 2,858,017 to Kent et al; and
lS 3. 653, 247; 3 , 844,151 and 4,103 , 529 to Huertigen . The patent to Kent
et al, discloses a die shifter having a first cylinder mounted on the
side of the platem adjacent and connected to a die slide assembly,
with a second cylinder attached to the platen with a rod which pulls
on the bottom of the die slide assembly. Both the first and second
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cylinders are used to shear the extruded article, whereupon the secondcylinder is used to shift the slide slightly from in front of the orifice
in the platen to enable an operator to lift the die out through the top
of the slide using a crane or the like, and replacing it similarly.
5 The '247 patent to Huertigen shows a die slide with empowering means
therefor extending distantly off one side of the press. The '151 patent
to Huertigen shows a die slide arrangement using a chain and sprockets
adapted to move a die in conjunction with hydraulic unitJ to a transfer
station. This type of die shifting mechanism is susceptible to contamination
lO from metal particles and necessitates constant cleaning and maintenance
of the hydraulic unit components.
It is an object of the present invention to provide a die slide
assembly which is compact and unobtrusive.
It is a further object of the present invention to provide a die
15 slide assembly which does not require constant cleaning and maintenance
as would some of the prior art.
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srief Summary of the Invention
The present invention comprises a die slide assembly
for an extrusion press, the slide assembly including a die
seated in a die holder, which die holder is movably supported
on a tracX adjacent one of the platens in the extrusion
press. The die holder is shuttleable to a convenient die
transfer station on one side of the platen by a dual
hydraulic piston and cylinder arrangement. One of the
hydraulic cylinders is arranged to be carried by the shuttle
mechanism itself to reduce the length of cylinder required
bo complete the die transfer to the side of the platen.
By carrying one of the hydraulic units on the shuttle
itself, the length of the piston rod and cylinder is reduced
considerably. This design minimizes the overall width
requirements for the extrusion press, as well as simplifies
the maintenance and operating procedures therefor, by
eliminating or restricting portions of the hydraulic unit
that would be otherwise exposed to contamination from the
scraps generated during extrusion of billets in the machine.
According to a further broad aspect of the
present invention there is provided an extrusion press having
a discharge assembly which comprises a platen against which
a die is supported for extrusion of material therethrough.
A'lholder is provided for the die and mounted for sliding
movements along the platen between an extrusion position and
a die transfer station. A two part assembly igl~moanted on
~ the platen for sliding movements with the holder. The
; assembly includes a primary slide containing a main cylinder
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and a secondary cylinder. A main piston is provided and
has a rod extending in one direction through one end of
the main cylinder and is secured to the platen. A secondary
piston has a rod extending in the opposite direction
through the opposite end of the secondary cylinder. The
secondary piston rod is fixed to a secondary slide forming
part of the assembly and is detachably secured to the holder.
The cylinders are arranged so that when the main and
secondary pistons and rods are fully retracted in their
respective cylinders, the holder and die are located in
extrusion position, and when the main and secondary pistons
and rods are fully extended, the secondary slide is moved
away from the primary slide and the holder and die are
located at the transfer station.
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Brief Descri;~tion of the Drawings
The objects and advantages of the present invention will become
more apparent ~,vhen viewed in conjunction with the following drawings,
in ~,vhich:
Figure 1 is an elevational view of a die slide assembly for an
e~trusion press constructed according to the principles of the present
invention; and
Figure 2 is a sectional elevational view of the empowering means
of the die slide assembly.
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Description of the Preferred Embodiment
Referring now to the drawings in detail, and particularly to
Figure 1, there is shown a portion of an extrusion press 10 comprising
a heavy front platen 12 and a heavy rear platen with a main press
5 cylinder mounted therebetween, not shown, the front and rear platens
being connected by an arrangement of four tie rods 14 that take up
the thrust of the extrusion operation therebetween. A die stack 16
is supported in a U-shaped die stack holder 18. The die stack holder
18 is movably disposed in a die slide assembly 20. The die stack 16
10 is of cylindrical configuration, configured orifice (s) having at least
one configured orifice 22 which is in line with an orifice or egress
hole extending through the front platen 12. The die slide assembly
20 includes a lower support track or gib 24 and an upper support
track or gib 26 both attached to and extending off of the rear or inwardly
15 directed face of the front platen 12. An empowering means 30, shown
in section in Figure 2, is arranged to mate with the die slide assembly
20. The empowering means 30 comprises a two-piece frame assembly
32 which is movable transversely of the front platen 12. The frame
assembly 32 includes a primary slide block 34. The primary slide
20 block 34 supportively encloses a pressurizable main cylindrical housing
36. A main piston head 38 is slidably arranged within the main housing
36, on a main piston rod 40. The end opposite the piston head 38
of the main piston rod 40 is securely connected to an arm 42 attached
to the front platen 12. The main piston head 38 has a plurality of
25 piston rings or seals 44 disposed thereon to prevent pressurizable
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fluid from seeping therepast. The primary slide block 34
also supportively encloses and secures a pressurizable
secondary cylindrical housing 46. A secondary piston head
48 having a plurality of piston rings or seals 54 thereon,
is slidably arranged within the secondary cylindrical
housing 46, on the distal end of a secondary piston rod 50.
The end opposite the piston of the secondary piston rod 50
is connected to a transport slide block 52. The transport
slide block 52 and the primary side block 34 are both
arranged in a sliding relationship between the upper and
lower support tracks or gibs 26 and 24, and they are in
close proximity with one another when both piston heads 38
and 48 are fully retracted in their respective housings 36
and 46.
A "T"-key S8 is secured to the lower edge of the
side face of the transport slide block 52. A "T"-slot 60,
as shown in Figure 1, is disposed in the lower portion of
one side of the die holder 18. A die hold-down finger 62
is attached to the face of the.primary slide block 34.
The hold-down finger 62 is disposed parallel to and is
spaced apart from the face of the transport slide block 52,
and extends through a bore 64 in the die holder 18, permitting
it to provide hold-down support to the die stack 16 when a
shear blade, not shown, is lifted from alongside the die
stack 16. The projecting end of the hold-down finger 62
has a curvilinear or angular surface 66 thereon to contact
the periphery of the die ring of the die stack 16 thereadjacent.
A die transfer station 70 is disposed on the side
of the front platen 12, opposite the side of the arm 42.
The die transfer station 70 comprises a lower support track
72 which may be arranged perpendicular
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to the die slide assembly 20. A transfer table 75is sliclably mounted
on the support track 72, at the level of the die slide assembly 20,
~,vhich assembly may intersect the lower support track 72 at roughly
its mid-point. The transfer table 75 may have another U-shaped die
5 stack holder 74 slidably arranged thereon, and may include a die
holder shuttle assembly, such as pressurized cylinders or the lil~e,
not shown, for moving the transfer table 75 with the first and/or the
second die holder 18 and 74 therewith. It is to be noted that the second
die holder 74 has a "T"-slot 76 near the bottom on one side thereof.
In operation of the extrusion press 10, the main press cylinder
forces a ram, not shown, to push a billet or slug of materi~1 to be
extruded through the configured orifice 22 in the die stack 16. The
forces generated in the die stack 16 are directed through the d;.e stack
holder 18 and the massive front platen 12. The tie rods 1~, which ;
15 are secured to a frame supporting the ram and to the rear platen,
not shown, absorb the stresses generated in the extrusion press 10.
The tail end of extruded billet may be cut off by a vertically arranged
shear, not shown, which shear may be disposed above the die 16 adjacent
the middle of the platen 12. When the vertically arranged shear is
20 lifted, there is a drag between it and the face of die stack 16 which
tends to lift the die stack 16 in the die stack holder 18. The die hold-
down finger 62 prevents vertical movement of the die stack 16 during
this portion of the operation.
When a die is to be changed, fluid under pressure from a suitable
25 fluid pressure source, not shown, may be delivered to the proximal
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end of the main piston shaft 40 through a conduit 41 and
passage 43 causing the entire frame assembly 32 to extend
to the left as seen in Fig. 2 along the main piston shaft
40 and to traverse across the front platen 12 along the
die slide assembly 20. Any extrusion remaining within the
die orifice 22 and the coaxial opening in the front platen
is sheared off at the plane therebetween. Fluid under
pressure may be deli~ered from the end of cylindrical
housing 36, through a conduit 45 (Fig. 1) and a passage 47
(Fig. 2), against the secondary piston head 48 within the
secondary cylindrical housing 46, either during pressuriza-
tion of the main cylindrical housing 36, or after that
occurrence, to effect movement of the secondary piston rod
50 out of the primary slide block 34, to cause continued
transverse movement of the transport slide block 52 and the
die stack 16 and die stack holder 18 thereattached. The
die hold-down finger 62 is retracted from its position
adjacent the die periphery and is withdrawn through the
` bore 64 in the die stack holder 18 as the transport slide
block 52 is separated from its position adjacent the
primary slide block 34. The die stack 16 and the die stack
holder 18 can be transferred to the transfer table 75 mounted
on the support track 72 on the side of the platen 12.
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The trans~er table 75 may then be moved by a
pressurizable piston and cylinder unit, not shown, away
from its association with the transport slide block 52,
thus d~sengaging the die stack holder 18 therefrom by
sliding the "T"-slot 60 away from its position enclosing
the "T"-key 58, permitting subsequent servicing of the
disengaged die stack 18. The new die holder 74, with
whatever die may be arranged therewith, none being shown,
may be attached to the transport slide block 52 by sl.Ldably
mating the "T"-slot 76 in the new die holder ~4 with the
"T"-key 58. Retracting the secondary and primary piston
rods 50 and 40, within their respective housing by exhaust-
ing fluid pressure from conduit 41 and delivering fluid
pressure through a conduit 49, passage 51 and conduit 53
leading from the conduit 49 to the left end of housing 46
effects displacement of the new die holder 74 and whatever
die is associated therewith to its pr,oper position at the
extrusion position adjacent the front platen 12.
Thus, there has been shown an extrusion press having
a die transfer system which eliminated an excessive projection
of pressurizable cylinders from the sides of the platen, and
which permits a relatively easily maintainable and efficient
die shearing operation free from the contamination and size
problems associated with the prior art extrusion press machines.
It is intended that the appended claims for the present
invention be interpreted as exemplary only, and not in a
limiting sense.
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