Note: Descriptions are shown in the official language in which they were submitted.
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ROLL FORMING LINE WITH PUNCHING TOOL
Description of Invention
This invention relates to a roll forming line.
A conventional line for producing roll formed-metal products has at least
one of a punching machine, comprising at least one punching unit, and a roll
forming machine, comprising a plurality of roll forming passes. It is
desirable
that the punching machine is adaptable in order to reduce the productive time
spent in changing the configuration of the punching machine.
Hitherto such adaptation of the punching machine has been time
consuming.
An aim of the invention is to provide a new or improved roll forming
line whereby the above mentioned problem is overcome or is reduced.
According to the invention we provide a roll forming line comprising at
least one punch unit wherein said at least one punch unit comprises a punch
having a punch head and ~ fluid operated actuating means having an output
element operable to move the punch head to punch a workpiece, the punch unit
having at least one of the following expedients:
a) adjustment means to adjust the pouch n~ansversely of said line,
b} cushioning means to cushion operation of said actuating means.
Electronic conri~ol means may be provided to control movement of said
output element.
The punch head may be slidable relative to a body by said actuating
means.
The actuating means may be c~uTied by a punch unit and the body may
be movable h~ansverseiy of the line relative to said punch unit.
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The body may comprise an upper limb in which said punch head is
slidable and a lower limb in which is provided an element which co-operates
with the punch head to punch the workpiece, the upper and lower limbs being
spaced apart by a gap to receive the workpiece.
Two bodies may be provided disposed side by side to receive opposite
sides of the body in the respective gap.
The or each body may be movable relative to the punch unit by the
adjustment means in a direction to transversely of said line.
The adjustment means may comprise an electric motor.
Alternatively, the adjustment means may comprise a fluid operated ram.
The fluid may be a gas such as air or a liquid such as oil.
Sensing means may be provided to sense the position of the or each
punch head transversely of the line.
Where the adjustment means is an electric motor the sensing means may
comprise an electric motor provided with an encoder.
Alternatively, whether the adjustment means is or is not an electric
motor, the sensing means may comprise a position transducer to sense the
position of the or each punch head.
The position n~ansducer may sense the position of the body and thereby
sense the position of the or each punch head.
The position transducer may provide a linear transducer or a
potentiometer.
The adjustment means and the sensing means may be connected in a
closed loop arrangement so that the or each punch may be positioned in a
desired position n~ansversely of the line.
Tlie sensing means may provide a signal to an electronic control unit in
dependence on the position of the or- each punch head.
The electronic contz~ol unit may be programmed to move the each body
during passage of a workpiece through the punch machine in order to permit
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the or each punch head to operate on the workpiece at least at two different
lateral positions.
Preferably said different lateral positions are at different longitudinal
positions along the line.
The or each fluid operated actuating means may comprise a piston
movable in a cylinder under fluid pressure and cushioning means to cushion
movement of the piston towards the punching end of its stroke.
The or each actuating means may comprise a position sensor to provide
a signal dependent upon the cylinder attaining a position adjacent to the end
of
its travel in the cylinder in the punching direction to operate said
cushioning
means.
The piston may be movable in the cylinder in a punching direction by
application of a pressure differential applied to the piston by the fluid in
the
cylinder.
The pressure differential may be applied to the piston by supply of fluid
under pressure to the side of the piston remote from the punching end of the
stroke and supply of fluid under the same pressure to the opposite side of the
piston, the area of the piston on said one side being greater than the area of
the
piston on the other side.
Movement of the piston in the return direction may be as a result of
connection of said side of the piston to reservoir whilst said other side of
the
piston remains connected to fluid under pressure.
The cushioning means may comprise a valve operable in dependence on
said signal to reduce the pressure differential applied by the fluid to the
piston
in the direction to cause said movement towards the punching end of the piston
stroke.
The valve may interrupt the supply of fluid to the side of the piston
remote from the punching end of its stroke and connect the other side of the
piston being connected to fluid under pressure.
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The valve may be provided in the fluid path to the cylinder and in a first
position to direct the fluid during the punching operation and movable to a
second position to direct the fluid during said return operation.
The roll forming line may further comprise a plurality of roll passes to
bend the workpiece into a desired shape.
The invention will IlOW be described by way of example with reference
to the accompanying drawings wherein,
Figure 1 is a plan view of a production line comprising metal forming
machines according to the present invention,
Figure 2 is a cross-section through a punching machine according to the
first aspect of the IrrVellt1011 111 a plane perpendicular to the axis of
travel of the
metal strip,
Figure 3 is a top view of the punching machine of Figure 2,
Figure 4 is a cross-section on line 4-4 of Figure 2,
Figure 5 is a cross-section on line S-5 of Figure 2,
Figure 6 is a side view, partly in section, of a hydraulic actuator of the
punching machine shown in Figures 2 to 5,
Figure 7 is a fragmentary diagrammatic illustration of part of a hydraulic
circuit relating to the hydraulic actuator of Figure G,
Figure 8 is an end view of a roll forming pass of a rolling machine in a
first configuration ,
Figure 9 is an end view of the roll pass of Figure 8 in a second
configuration,
Figure 10 is a side view of the roll pass of Figure 8, and
Figure 11 is a top view of the roll pass of Figure 8.
'The line, as shown in Figure 1, of the present example comprises a
plurality of machines for forming products from strip metal and comprises an
un-toiler 10 of conventional type. Ship metal is unwound from a coil mounted
on the un-toiler 10 and passes, via a peeler and flattener as necessary, to a
crop
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shear 11 where the snip is provided with a leading edge which is at right
angles
to the length of the strip.
The strip then passes to a looper 12. The formation of a loop on the
strip metal enables the line to accommodate, in conventional manner, changes
in the speed of the strip passing along the line.
The strip then passes to a punching machine 13 comprising three punch
units embodying the first aspect of the invention. If desired the punching
machine may comprise any desired number of punch units from 1 upwards.
The punching machine punches holes or notches in the sri~ip.
Downstream of the punching machine 13 is a cut-to-length shear 14 in
which lengths of material are separated from the roll to produce a product of
a
desired length. The discrete separated lengths of punched material are fed by
a
conveyor, such a skew conveyor, to a roll forming machine 15.
The roll forming machine 15 comprises a plurality of roll passes at least
one of which comprises a roll pass as shown in Figures 8 to 11.
Downsh~eam of the roll for-rning machine is a run out table 16. The
production line may be varied from that described above to include as
appropriate numbers of the elements described above or other conventionally
provided elements depending on the desired product and the nature of the metal
being acted upon.
In a punching machine embodying the invention each of the three punch
units of the punching machine 3 comprises a punch unit 20 as shown in Figures
2to7.
The punch unit 20 comprises a bridge unit ha~~ing a pair of end plates 21
and a top plate 22. An aperture 21 a is provided in the end plates 21 in which
the strip metal is received. A pair of punches 23 are disposed between the end
plates 21. Each punch 23 comprises a C-shaped body 24 comprising an upper
limb 24a having a punch head 2~ slid:rble therein and a lower limb 24b with a
gap 24c therebetween. The open side of the C-shaped body 24 of each punch
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23 faces longitudinally of the punch unit 20 such that when the strip metal is
introduced into the punch unit in the direction shown at A on Figure 4 it may
pass through the aperture 21 a of one end plate 21, tlwough the gap 24c of
each
C-shaped frame 2-1 and throul;h tl~e aperture 21 a of the other end plate 21.
Each punch head 25 has a punching end part 25a.
The left hand i.e. leading, end plate 21 in Figure 4 is provided with
upper and lower guides 21b, 21c to guide the strip metal through the punches
23. The lower limb 24b of the C-shaped body 24c is disposed below the
punch head 25 and comprises a raised part 26a which houses a die 26b which is
to co-operate with the punching end part 25a of the punch head 25 to form an
aperture or notch in the sheet metal of a desired configuration depending upon
the shape of the punching end part 25a of the punch head 25 and the die of the
lower end pairt 2G.
Each punch 23 is attached by bolts 27a to a traversing plate 27 slidable
in a guide defined by a base part 28, a side part 28a and a cover part 28b_
disposed either side of the traversing plate 27, the base pau 28, side part
28_a
and cover part 28b being connected together by bolts 28c. An internally
threaded nut part ?9 is attached to the hvversing plate 27 and is in threaded
connection with a threaded rod 30. The threaded rod 30 is housed in roller
bearings 31, 32 and is driven by a servo motor 33. The base parts 28a, end
plates 21 and servo motors 33 are attached to a bridge base unit 34.
Actuating means 35 are provided for each punch 23 comprising a
cylinder 36 having a piston 3Ga and a piston rod 36b. The actuating means 35
further comprises a timing plate 37 having a groove 38 which provides a
slideway in which a flange 39 attached to an upwardly extending part 40 of the
punch 23 is received. The piston rod 36b of the cylinder 3G acts on the timing
plate 37 via a plunger 41. Upwardly extending rods 42 attached to the timing
plate 37 are received in apeaures 4 ~ provided in the top plate 22, and are
slidable therein to ~~uide the timing plate 37.
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In operation, a work piece comprising strip metal is passed into the
punch unit in direction A through aperture 21 a of the left hand end plate 21.
The strip metal is guided by guides 21b and 21c and passes through the gap 24c
and between the punch head 25 and die 2Gb of each punch 23. Hydraulic fluid
is supplied to either or both of the cylinders 35 according to the pattern it
is
desired to punch in the strip. The or each cylinder 35 acts via plunger 41 on
the timing plate 37, which depresses the punch head 25 of the punch 23 such
that the punching end part 25a of the punch head 25 passes through the strip
metal to foam a hole or notch therein.
The punch machine 1G provides a relatively high speed of production
with a minimum of noise and vibration.
The actuator 35 is provided with a suitable position indicator for the
piston 36. In the present example this comprises a linear tz~ansducer 44
having
a body 44a fixed to the cylinder 3G and housing element 44b which is movable
with the piston 36. The linear transducer, in conventional manner, provides an
input to a micro-processor based on a control unit to provide information as
to
the position of the piston 3Ga relative to cylinder 3G.
The actuator 35 also is provided with a servo valve 45 which is supplied
with hydraulic fluid under pressure on a line 46 whilst a line 47 is provided
to
connect the valve 45 to a reservoir. A branch line 46b is provided to connect
the line 46 to the piston rod side of the cylinder 3G. The valve 45 is
connected
by a line 48 to the opposite side of the piston 36a. In the first position of
the
valve 45 as shown in Figure 7, no fluid flow to or from above the piston 36a
is
permitted.
In use, when the electronic unit provides a suitable signal to the servo
valve 45 it is moved to a second position so as to feed fluid under pressure
from
line 46 to line 48 to cause piston 3Ga to move in a punching direction as a
result
of the pressure differential on the piston due to the area of the piston 36 or
the
piston rod side thereof being smaller than the area of the piston on the
opposite
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side. Hence piston rod 36b moves downwardly and thus causes the punch to
punch a workpiece.
Shortly before the piston 3Ga reaches the full mechanical length of the
stroke permitted by the length of the relevant region of the cylinder 36 the
linear transducer 44 provides a signal to the electronic control unit which
sends
a signal to the valve 45 to cause the valve to move to a third position so
that the
side of the piston 3Ga opposite to the piston rod 36b is connected by the line
48
to reservoir. The piston rod side of the piston 36a is connected by the line
46b
to fluid under pressure. Further downward movement of the actuator as a result
of inertia is prevented by a reversed pressure differential acting; on the
piston
36a and the piston 3Ga and hence tl~e piston rod 3Gb and the punch is moved
upwardly by the pressure of oil in the lines 4G and 4Gb oil above the piston
36_a
being returned to reservoir on lines 48 and 47. As the piston moves upwardly
the linear transducer 44 senses when it approaches the end of its mechanically
permitted stroke and the servo valve 45 is moved to its first position in
which
flow of fluid from above the piston is prevented. As a result upward movement
is cushioned.
Although in the present example the position of the piston 36a is
determined by a linear transducer other suitable means may be provided such as
a potentiometer. In all cases a closed loop electronic circuit using a micro-
processor controlled electronic control unit programmed with a suitable
software program is used.
The al-rangement described above allows the punch to operate so that the
piston 36_a is cushioned from both punching and return movement and can be
accurately brought to rest at the top and bottom of its working stroke which
is
within the full mechanical stroke of a piston within the cylinder.
In addition the position of the top and bottom of the working stroke can
be accurately adjusted lIl SIllall steps for example of 0.1 mm to allow for
setting
adjustments for the simplicity of setting the tooling after for example re-
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grinding of the tool rig or other re-setting. Such adjustment may be
conveniently provided in the software program so as to be conveniently set up
by a user.
When it is desired to v~uy the location of the punched holes or notches,
e.g. motors with encoders on setting up the line for a production run the
servo
motors 33 are actuated to move the or each punch 23 laterally to the desired
position. The position of the or each punch 23 is monitored electronically and
be fed back to a control system which may further conri~ol the motors, thus
providing a closed loop with feedback and the or each punch unit can thus be
computer controlled to quickly vary the punch setting.
To alter the shape or size of the punched holes, each punch 23 can be
easily removed from the traverse plates 27 by removing the bolts 27a and
replaced by a further punch 23 having punching end pants 25a of a desired size
or shape.
Where it is desired that both punches always operate together only to
punch pairs of holes, a single timing plate 37 engaging both punches 23 can be
provided, and actuated by a single cylinder 3G. Operation of the cylinder will
operate both punches 23 at the same time. In the configuration comprising a
pair of cylinders 3G as shown in Figures 2 to ~, the cylinders may be operated
independently to provide pairs of punched holes or other punch patterns as
desired. Further alternatively, only a single punch 23 may be provided if
desired. The punch unit 20 is therefore easily and quickly re-configurable to
provide a punch pattern having a particular spacing size or pattern of holes
as
required.
If desired, and as in the present example, tlu~ee longitudinally disposed
punch units 20 are provided and the metal strip is moved longitudinally to
position a desired pouion thereof in operative relationship with each punch
unit
to that a desired pattern of apertures and/or notches may be achieved.
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Although in the above example the adjustment means have comprised
servo motor 23 having encoders, if desired electric motors not having an
encoder could be provided with a suitable transducer to provide feedback to
the
electronic control unit. Further altel-natively instead of providing an
electric
motor suitable hydraulic or pneumatic cylinders with a suitable transducer may
be provided to move the punches h~ansversely of the line.
When during operation of the line, it is desired to vary the lateral
position of the punched holes or notches at the same or different longitudinal
positions of the workpiece the servo motors 33 may be actuated, during
operation of the line, so as to move the or each punch 23 laterally to the
desired
initial position and then to a desired further position or further positions.
In
such a case when the workpiece is in a first longitudinal position
corresponding
to a first lateral position of the punch or punches the or each punch 23 will
then
be actuated to form a desired hole or notch arrangement, then the workpiece is
moved to a desired second longitudinal position and the servo motor or motors
33 actuated to move the or each punch laterally to the second desired lateral
position whereupon the or each punch is then actuated again to form a desired
hole or notch configuration and similarly for any other desired position
either
laterally and/or longitudinally at which the or each punch is desired to be
operated.
As in the case of operation of the servo motors 33 on set-up of the
machine, as described above, the position of the or each punch 23 is monitored
electronically and fed back to a control system which further controls the
motors 33 thus providing a closed loop with feedback so that the or each punch
limit is thus computer controlled to quickly vary the punch setting during
operation of the machine. Of course if a different configuration of hole or
notch is required at different positions then a different set of punches would
be
used but again the lateral position of the or each additional punch may be
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varied either on set-up or in use as described above by operation of the
appropriate servo motors 33.
A guide table is provided for the lateral guiding of ship upstream and
downstream of the punching machine.
A roll foaming machine embodying the invention comprises a plurality
of roll forming passes 50 one of which is shown in Figures 6 to 9. Each
successive pass progressively forms the work piece from a flat shape to a
final
shape, in the present example to be described hereinafter a C-shape, and
punched with a pattern of apertures provided by a punching machine as
described hereinbefore. The punching machines and roll foaming machines as
described herein may of course be used independently as required.
The first pass will now be described by way of example but it will be
accepted that apart from the form of the individual rolls all the passes will
be
similar.
Each roll foaming pass 50 comprises a first stand 51 and a second stand
52 disposed alongside one another, 111o11Ilted on a base unit Sla 52a_
respectively. Base units S l a, 52a may be mounted such that they are moveable
in a lateral direction transverse to the direction of navel of the work piece
to
vary the separation between the first stand 51 and the second stand 52. Either
or both stands may be moveable in this fashion, and may be moved either by a
manual technique such as a hand wheel, or by semi-automatic or fully
automatic control systems.
The work piece may be driven by drive rollers provided in drive
sections, not shown, in which the work piece is passed between a pair of drive
rollers. The pinch between the drive rollers may be adjusted in accordance
with the gauge of the work piece. Where the drive section is at least partly
laterally adjustable in similar fashion to the base units Sla, 52a of the roll
forming pass described above, drive may be provided to the drive rollers from
a
fixed drive source by a universal shaft.
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The first stand ~ 1 comprises a first upright 53a and a second upright 53b
attached to the base part S la. The upright parts 53a 53b are connected at
their
upper ends by a top plate 54. Each upright 53a, 53b comprises a projecting
part 55_a SSb projecting towards the opposing upright part and parallel
thereto.
Received on the projecting pants SSa SSb is a slider plate 56 having recesses
56a 56b at either end in which cowesponding projecting parts SSa SSb are
received. The slider plate SG is connected to a piston of a pneumatic ram 59
mounted on the top piste S4. Tlie slider plate is thus moveable in a generally
vertical direction by the ram 59 guided by the projections SSa, SSb. Mounted
on the base plate Sla are a pair of upright guide rods 61a_, 61b received in
corresponding holes 62a, G2b in the slider pact SG. A stop means 63 is
provided
attached to the base plate S l a disposed between the rods 61a 61b to limit
downward movement of the slider SG.
Mounted on the slider plate SG is a first roller 64 having a fillsto-conical
portion 64a tapering in a direction away from the slider plate 56 with a
generally cylindrical portion G4b at the nawow end of the fi-usto-conical
portion
64_a. The roller 64 is mounted on a shaft 65 by bearings 65a. The shaft 65 has
an eccentric mounting part G6, the eccentricity is not shown in the figures,
which is received in bearin l;s GGa in a sleeve G7 fixed to the slider 56. The
roller 64 is mounted upon the shaft G5 which has a longitudinal axis which is
offset from a longitudinal axis of the mounting pau 66 received in the
bearings
66a. An end portion of the mounting part G6 is attached to a lever G8, the
lever
68 being offset with respect to the part GG. The end of the lever 68 distant
from
the mounting part 66 is attached to one end of a pneumatic ram 69, the other
end of the ram 69 being attached to the slider SG. The bore side of the
cylinder
69a of the pneumatic ram is supplied with air under pressure, thus acting to
move lever G8 in an anti-clockwise direction as seen in Figure 8, into
engagement with a first stop G8a
The roller 64 is held on the shaft 65 by an end cap 65b.
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The first stand ~ I further comprises an upper roller 70 and a lower roller
71. The rollers 70 and 71 each comprise a first generally cylindrical portion
70a, 71a disposed away from the stand S I and a fi-usto-conical portion 70a,
71_a
having its widest part adjacent the cylindrical poaion 70a, 71a and tapering
towards the part 51.
The lower roller 70 is mounted on shaft 72 received in bearings 72a and
held on shaft 72 by an end cap 72b. The shaft 72 is fixedly mounted in a
sleeve
73 provided in the slider SG.
The upper roller 69 mounted on a shaft 74, by bearings 74a. The shaft
74 has an eccentric mountin l; part 75, the eccentricity is not shown in the
figures, which is received in bearinbs 75a provided in the slider 56. Again,
the
shaft 74 has a longitudinal axis which is offset from the longitudinal axis of
the
mounting palrt 75. :~s with the first roller G4 an end portion of the mounting
part 75 is provided with a lever 77 offset from the mounting part 75 and
attached pneumatic ram 78. The other end of the pneumatic ram 78 is
connected to the slider SG. The pneumatic ram 78 comprises a cylinder 78_a,
air
under pressure being supplied to both sides of said cylinder 78_a such that
the
pneumatic cylinder 78 acts on a lever 77 to rotate it in a generally anti-
clockwise direction as seen in Figure 8 into engagement with a stop 74a.
The second stand 52 comprises a first roller 90 having the same features
and being mounted in the same fashion as roller G4 and a lower roller 91
having
the same features and being; mounted in the same fashion as lower roller 70 of
part 51.
In operation, the first stand 51 and second stand 52 are disposed
opposite each other as shown in Figure G such that rollers 64 and 90 are
coaxial
and rollers 70 and 91 are coaxial.
Strip metal is introduced into the roll forming unit in the direction B
shown in Figure 8. The metal strip in between the rollers G4, 71 and 90, 91 in
the present example, is formed to the first shape of rolling a C-shaped
profile.
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Forming of the metal strip to a desired profile is accommodated by the
pressure
applied to the ram without causing any movement of the ram. However,
dependant on the gauge of the metal strip introduced, the resulting resistance
of
the strip arising from the gauge of the workpiece may force the roller 64
upwardly, forcing the shaft 65 to rotate about the axis of mounting part 66,
thus
acting to increase the gap between roller 64 and roller 71. This movement is
opposed by the ram 69 acting on lever 68 to rotate the shaft 65 about the axis
of
the mounting pact G6 producing an increased downwards force on the roller 65.
The roller 91 on the stand 52 operates in similar fashion. The roll forming
unit
thus accommodates strip metal of different gauges without requiring any
external alteration. Clockwise movement of the lever 68 is limited by a stop
69b_. The eccentric mounting of the roil G4 restrains downward movement of
the roll 64 as a result of downward force applied thereto by the introduction
of
the 7 between the roll 64 and the roll 71.
If it is desired to produce an article hamng a Z-shaped profile rather than
a C-shaped profile then, prior to the introduction of strip metal into the
roll
forming unit, the roll forming unit is moved to the configuration shown in
Figure 7. By actuating the pneumatic ram 59, the slider 56 is moved
downwards until its lower surface abuts the stop 63. In this position, the gap
between the rollers 65 and 69 is aligned with the gap between rollers 90 and
91.
Strip metal inh~oduced in the direction B thus has opposite edges folded in
opposite directions at the first stage of foaming a Z-shaped profile.
The forming of the metal sri~ip to the desired profile is accommodated by
the pressure applied to the ram 78 without causing any movement of the ram.
However, dependent upon the gauge of the metal snip introduced the resulting
resistance of the stl-ip arising from the gauge of the workpiece may force the
roller 70 upwardly, forcing the shaft 7~ to rotate about the axis of the
mounting
part 75 by acting to increase the gaN in the roller 64 and the roller 70. This
movement is opposed by the ram 78 acting on lever 77 to rotate the shaft 74
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1S
about the axis of the mounting part 7S to produce an increased downwards
force on the roller 70. The roller on the stand S2 operates in a similar
fashion
with the C-shaped embodiment described hereinbefore. Clockwise movement
of the Iever 77 is limited by a stop 79b.
The roll forming unit is thus quickly and easily adaptable to provide one
of two different rolling profiles and to accommodate different gauges of
metal.
The roll forming unit is operated in conjunction with drive means comprising
at
least one set of non-shaping driven rollers to move the workpiece. At least
the
first pass in a roll foaning machine 1 S is not driven. Although in the
majority
of cases the roll-fot~ning passes are kept separate from driven rollers it
will be
appreciated that one or more roll forming passes may be provided with drive
means. The absence of drive means for the forning rollers enables the rollers
to be moveable as set out above to accommodate different metal gauges without
the necessity of providing means to transfer drive to the rollers. Further, if
the
rollers were driven they would simultaneously be flying to drive metal strip
and
provide a bending force. This could lead to inconsistent driving speed of the
strip and cause slip and damage to the strip and machinery.
A line may thus comprise at least punching machines 12 comprising one
or more punch units 20 and/or rolling machines l~ comprising one or more
rolling units S0.
The features disclosed in the foregoing description, or the following
claims, or the accompanying drawings, expressed in their specific forms or in
terms of a means for pei-fonning the disclosed function, or a method or
process
for attaining the disclosed result, as appropriate, may, separately, or in any
combination of such features, be utilised for realising the invention in
diverse
forms thereof.
