Note: Descriptions are shown in the official language in which they were submitted.
lZ~39~81
A process and de~ice for feeding a thin binder impregnated un-
cured primary web of mineral wool onto a recei~ing conveyor
The present in~ention re1ates to a process for feeding a thin
binder impregnated uncured mineral wool web on a receiving con-
~eyor and to a de~ice for carrying out the process according to
the preamble of claims 1 and 9.
When manufacturing mineral wool sheets, it is crucial to achie~e a
product that is as uniform and homogenous as possible, yielding a
higher insulation capacity. Moreo~er, it should be as elastic as
possible at a low density, requiring the fibres to be extended
mainly in the sheet plane. Due to the elasticity, the sheet may be
compressed for the packing and transport step.
in order to achie~e this, a thin primary web, of which the basis
weight ~aries in the range of 110 to 450 g/m , preferably 100
to 200 g/m is collected on a collecting con~eyor immediately
after the defibration. The thinner the primary web, the better
the quality of the finished product. In order to keep the capacity
on the desired level while producing a thin primary web, the speed
of the primary web as well as that of its con~eying de~ices has to
be high. Normally, the speed of the primary web is o~er 100 m/min,
howe~er, the basis weight of the primary web being only in the
range of 100 to 200 g/m , an e~en higher speed is required in
order to keep the capacity on the desired le~el.
Various methods of folding mineral wool webs are described in the
US patent specification 2 450 916 from 1948 and the somewhat
younger GB patent specification 772 628, among others. These ha~e
subsequently been completed with methods of folding the primary
web by means of pendulum con~eyors.
~289381
When pendulum con~eyors are being used for the feeding out of pri-
mary web, it is critical that the speed of the output end is about
the same as that of the primary web, in order to a~oid folding or
stretching of the web at the output moment.
Up till now, the pendulum mechanism usually has comprised an ope-
ration, in which the extreme positions ha~e been highest
abo~e the recei~ing con~eyor, and the lower dead point of the
pendulum has been closest to the recei~ing con~eyor. In order to
achie~e the desired capacity with the thin primary webs, the out-
put rate of the pendulum con~eyors should increase, howe~er this
is not feasible with known de~ices. In fact, a high speed pendu-
lum conveyor that feeds out a light web and has a high pendulum
frequency yields an inexact laying of the primary web. A pendulum
con~eyor dri~en in a known manner by a connecting rod and oscil-
lating along a circular arc imparts a speed to the output end of
the con~eyor that is maximal when the pendulum is in the central
position and decreases sinusoidally to zero in the extreme posi-
tion, from where a sinusoidal acceleration reoccurs. The output
end of such a pendulum con~eyor must, in its lowest position, be
disposed c. 0,2 times the output width, which normally is 2 m,
abo~e the fed out wool web, in order to allow the primary web to
be deposited in an uniform layer on the recei~ing con~eyor without
being stretched. The distance between the pendulum and the recei~-
ing con~eyor being that long up to 40 cm and more, the fed out
web will get une~en edges. The output rate being c. 130 m/min,
the irregularities of the secondary web formed will be c. +/_ ~a
of the output width. This signifies that the secondary web must be
imparted a correspondingly larger width in order to achie~e a
faultless web of the desired width, since the undesired material
has to be cut off. This means a great loss of material.
Pendulum output mechanisms, in which the folding process is car-
ried out by continuously feeding out the primary web at a constant
height abo~e the support, at a constant height, are also known. An
128998~
articulation system for maintaining the output end of the pendulum
mechanism at a constant height abo~e the receiving con~eyor is
pro~ided, and the to and fro motion is obtained by a chain/con-
necting rod-mechanism. The speed profile of the oscillating motion
has a constant speed period in the middle and a sinoidal retarda-
tion and acceleration phase in each end position. The pendulum
must be rapidly retarded and accelerated in the end positions for
the pendulum motion to correspond to the output amount of the
primary web per unit of time, causing great strains in the mechan-
ical constructions. Consequently, the mechanism is appropriate
only at output rates below c. 100 m/min.
Another drawback of pendulum mechanisms ha~ing a high pendulum
frèquency is constituted of the strong flows of air generated
by the rapid back and fro motion of a pendulum mechanism ha~ing a
large surface. The air flows hamper the depositing of the thin
primary web onto the bed.
Prior known are thus pendulum mechanisms for feeding thin pri-
mary webs in o~er-lapping layers on a recei~ing con~eyor.
However, they all present considerable drawbacks; the edges are
uneven, causing great loss of material, the speeds are too low to
fullfil the capacity requirement, the retardation and acceleration
forces are strong, causing great mechanical stress in the con-
structions: the problem of air flow jeopardizes the depositing of
the primary web.
The purpose of the present in~ention is to reduce or totally
eliminate these drawbacks, and especially to obtain an exact out-
laying with e~en edges and a web with high homogeneity, and this
has been achie~ed by pro~iding a method and a de~ice, of which the
main characteristics are presented in claims 1 and 6
In a preferred embodiment of the in~ention a prior known dri~e
system is used, imparting to the oscillating pendulum con~eyor,
called pendulum from now on, a constant rate of motion in the
~ ~r
1289981
middle of the pendulum motion and a sinusoidally decreasing
respecti~ely increasing speed in the extreme positions of the
pendulum motion. The period ha~ing constant speed may be in
the range of 30 to 60% of the entire pendulum swing. The
constant speed of the pendulum in the central area equals totally
or nearly totally the output rate of the primary web. This enab-
les the pendulum to be disposed closer to the recei~ing surface,
at about half of the distance allowed by con~entional crank dri~e,
thus ensuring considerably better the deposit and the fixation of
the primary web on the recei~ing con~eyor.
In areas outside the phase ha~ing a constant speed the pendulum
is dri~en at a sinusoidally decreasing respecti~ely increasing ra-
te, while the pendulum pursues its pendulum motion. At least
during part of the motion at a decreasing respecti~ely increa-
sing rate in the extreme positions of the pendulum swing, the
output end of the pendulum is arranged to rise in the final phase
of the pendulum motion and to sink in the initial phase. Due to
the changing of the height of the pendulum in the retardation re-
spectively the acceleration phase, potential energy is stocked
respectively discharged, resulting in less stress forces on the
mechanism than those generated when the output end of the pendulum
describes a horizontal path o~er the entire pendulum swing.
The pendulum motion, consisting of a central portion ha~ing a
constant speed and two extreme portions having retarding and ac-
celerating speeds, is appropriately produced by means of an end-
less dri~e chain running over two coplanar interspaced chain
wheels, whereby a connecting rod connects the pendulum with a
carrier on the dri~e chain. The centre distance of the chain
wheels corresponds to the portion of the pendulum motion ha~ing
a constant speed and half the circumference of each wheel corres-
ponds to the pendulum motion ha~ing retarding and accelerating
speed.
~28998~
The pendulum motion consisting of a central portion ha~ing
constant speed and two extreme portions ha~ing retarding and
accelerating speed may also be produced by means of a so-
called Ferguson gear, in which the rotary motion is transmitted
by elliptical gear wheels.
The output end of the pondulum may be guided to mo~e along diffe-
rently shaped paths in the course of the pendulum motion. The most
simple embodiment is an arched trajectory, whereby the pendulum
swings around a stationary point of bearing. In such an embodi-
ment, the pendulum operates with great accuracy at output rates of
c. 200 m/min. This is allowed by the fact that the output end of
the pendulum may strike ~ery close to the recei~ing con~eyor, and
closest thereto at the midpoint of the total swing, whereby the
fed out primary web may be immediately fixed into the underlying
fed out wool web and thus remains undisturbed by the air flows
caused by the pendulum motion. In the extreme positions of the
pendulum motion the lower end of the pendulum rises c. 0.1 times
the output width i.e. appr. 20 cm with an output width of 200 cm,
resulting in a more exact position for the edge folding, due to
the smaller folding loop of the wool web. Another ad~antage of
this embodiment is that the pendulum may be relati~ely short, c.
0.7 to 1.0 times the output width, i.e. c. 140 to 200 cm, which
results in lower mass-moments of inertia and smaller stresses in
the dri~ing de~ice. The air flow disturbances are also reduced by
a shorter pendulum.
In this embodiment, the pendulum may be adjusted to strike at
its closest point only 5 to 10 cm above the recei~ing con~eyor
and thus to fix almost immediately the fed out web into the
central area of the trajectory. This results in a wool web ha~ing
~ery e~en edges. At a constant speed of abo~e c. 50% of the out-
put width, which is 200 cm, and a maximum pendulum swing of 80%
and a pendulum length of c. 75% of the output width, i.e. 150 cm,
the pendulum rises c. 12%, i.e. 24 cm, in the extreme positions.
~289981
Another preferred embodiment of the in~ention is the one in which
the pendulum and its output end are made to mo~e horizontally at
a constant height abo~e the recei~ing con~eyor in the central zo-
ne of the pendulum swing and to rise abo~e this in the outmost
positions.
The rising motion may be started at any point after the mid point
of the pendulum motion, but at the latest during the retardation
phase of the pendulum motion, thus allowing for the primary web,
which is fed out from the output end of the pendulum at a constant
rate, enough space below the output end which then mo~es at a low-
er rate than the output rate of the primary web. The rising mo-
tion thus starts at the earliest immediately after the mid point
of the pendulum motion, the pendulum and its output end then
describing a continuous arched line, or at the latest at such a
point before the extreme position of the pendulum swing, that
enough space is allowed to be formed below the rising pendulum for
the accumulating loop to settle under control and to form an e~en
edge during the re~erse motion.
The path described by the output end may be a linearly rising,
circular, progressi~ely arched line or ~arious combinations of
these.
By means of various guide de~ices the pendulum or its output end
is forced to de~iate from the natura1 pendulum motion ha~ing a
circular output path. From the moment there is a de~iation from
the natural pendulum motion, the oscillating point of the pendulum
must be ~ertically mo~able or the swinging radius of the output
end be ~ariable.
An output traiectory consisting of a mainly horizontal central
portion and an arched end portion being desired, an arm mounted on
bearings in the pendulum may for instance comprise a lower end
that is pi~otally mounted on bearings outside the pendulum, thus
1~89g81
forcing the pendulum to describe an essentially horizontal path.
During this part of the motion the oscillating point of the pen-
dulum sinks/rises. The oscillating point has been disposed so as
to reach a stop or else stop in the position in which the pen
dulum is to pass into a rising motion in the outmost zone of the
pendulum swing respecti~ely sinking motion in the same zone during
the re~erse motion. The mounting of the arm on bearings in the
pendulum is disposed so as to enable the pendulum to oscillate
with regard to the arm at this stage, e.g. be means of fork bear-
ings. A spring may appropriately be disposed between the connec-
ting rod top of the pendulum and the arm guiding the height posi-
tion of the pendulum, whereby the acceleration and retardation
forces are partly equilibrated in the extreme positions of the
pendulum.
The motion of the pendulum may also be guided by for instance a
fixed guide disposed symmetrically with regard to the central
axis along which a wheel mounted on bearings in the pendulum or a
sliding body are disposed to mo~e. The trajectory of the output
end will then correspond to the shape of the guide. The height of
the guide abo~e the ouptut end is determined by the optimization
of geometry and mass forces.
The oscillating point of the pendulum may alternati~ely be sta-
tionary while the output end is radially mo~able in relation to
the oscillating point.
The in~ention will be described more in detail belGw as a number
of preferred embodiments of the in~ention and referring to the
enclosed figures, in which:
figure 1 presents a schematical representation of the pendulum
motion of two preferred embodiments; the motion of the pendulum
at a constant speed and subsequently at a retarded and an accele-
rated speed, while the output end of the pendulum describes a cir-
~ Z89~
cular path (case A) respectively the motion of the pendu1um at a-
constant speed and subsequently at a retarded and an accelerated
speed while the output end during the constant speed phase moves
at a constant height above the receiving conveyor and during the
retardation respectively acceleration phase moves along an arched
path (case 8),
figure 2 shows a preferred embodiment of the pendulum including
the associated driving device and the pendulum shown in three
different positions, and
figure 3 shows another preferred embodiment of the pendulum in-
cluding the associated driving device and showing the pendulum in
three different positions.
In figure 1, the right side of the figure shows the case (A), in
which the pendulum both during the period at a constant speed and
the period at a retarded and an accelerated speed oscillates
around the point P, which is stationary in this case, and the
output end describes a circular arc. The pendulum is driven by
the guide device D by means of a chain having constant speed.
A connecting rod V is mounted on bearings on a carrier to the
drive chain at the point T and to the pendulum mechanism at the
point K . In the drive chain the points 1 to 12 have been mark-
ed, whereby the points 1 and 7 indicate the central position of
the pendulum, the points 4 and 10 the extreme positions of the
pendulum and the points 12 and 2 respectively 6 and 8 the limits
of the area having a constant speed. When the point T of the
connecting rod is in the position 1, the pendulum is suspended
from the oscillating point P and the position of the output end is
indicated by the number 1 (A). From 1 to 2 the connecting rod mo-
ves at a constant speed and the output end describes a circular
arc since the oscillating point P is stationary. From 2 to 4 the
pendulum moves with retardation, changes the direction o~ motion
at the point 4 and from 4 to 6 with acceleration, while the out-
,
~2sssal
put end describes a rising respecti~ely sinking circular arc fromthe connecting rod 6 to 7 mo~es at a constant speed, while the
ouput end describes a rising respecti~ely a sinking circular arc.
Depending on the position of the fastening point KA on the pen-
dulum with regard to the dri~e de~ice D, more or less geometrical
assymmetry is achie~ed, i.e. the points 3 and 5 respecti~ely 2 and
6 deviate somewhat from each other, which appears from the rough
drawing. The pendulum rises in the extreme position 4 c. 24 cm,
which also appears from the figure drawn in the scale 1:10, and
forms a controlled loop of the primary web at the turning point.
Owing to the smaller distance of the output end to the recei~ing
con~eyor S and the synchronization between the output rate and
the oscillating rate of the output end, the fed out primary web is
rapidly fixed to the bed, which also appears from the rough draw-
ing. The motion of the pendulum from the point 7 to 1 is the re-
verse image of the motion between the points 1 and 7, howe~er not
represented.
The left side of figure 1 shows the case (B) in which the output
end of the pendulum during the period of constant speed mo~es at a
constant height abo~e the recei~ing con~eyor SB and during the
period of retarded and accelerated motion mo~es along a circular
path. In the central position of the pendulum, point 7, the oscil-
lating point of the pendulum is at P but sinks to the point P
during the dri~e motion up to point 8, whereby the output end mo-
~es along a horizontal line. During the retardation phase from
point 8 to 10 and the acceleration phase from point 10 to 12, the
oscillating point P is kept stationary and the output end descri-
bes a circular arc. As it appears from the figure, the recei~ing
con~eyor SB is situated higher than in case A, because the
oscillating point of the pendulum is higher placed in the central
position in case B.
,
-:
,
`
~289~8~
The pendulum rises in its extreme position c. 16 cm, which appears
from the figure. The looping is well controlled also in this case
due to the short distance of the primary web to the bed particu-
larly o~er the distances 7-8 and 12-1 and to the synchronization
between the output rate and the oscillating rate of the output end
o~er these distances.
In order to make the output end of the pendulum mo~e horizontally
during a major part, in the shown cases 50% of the pendulum swing,
whereby the oscillating point must mo~e from P to P, special
measures are required. Two preferred embodiments of such arrange-
ments are shown in f;gures 2 and 3.
Figures 2 and 3 show the pendulum part of a machine for producing
mineral wool web and the associated dri~e mechanism. The recei-
~ing con~eyor of the primary web is marked with 1, the associated
pendulum con~eyor with 2, the two opposite con~eyors with 2a and
2b and the conducting rollers in the output end with 3a and 3b.
The receiving con~eyor has been marked with 4, the dri~e mechanism
with 5, the two wheels of the dri~e mechanism with 5a and 5b and
the connecting rod with 6. The parts 1 to 6 correspond mutually
in the figures 2 and 3 and ha~e thus been marked with the same
numbers.
In figure 2, the wheel that conducts the pendulum motion in a
guide de~ice has been marked with 7 and the axis of the wheel fi-
xed on the pendulum con~eyor with 7a. The guide along which the
wheel 7 has been arranged to run and which determines the tra-
jectory of the output end has been marked with 9. The output end
of the pendulum con~eyor has been marked with 10.
When producing a mineral wool web, the primary web is fed out on
its recei~ing con~eyor 1 and runs further between the con~eyors
2a and 2b into the pendulum mechanism 2, and is fed out at the
output end 10. The pendulum swings to and fro while the primary
web is being fed out between the conducting rollers 3a and 3b. As
i289~
the connecting rod mo~es between the dri~e wheels 5a and 5b, the
distance b , the wheel 7 gains a constant rate of motion and
simultaneously mo~es o~er the plane portion of the guide 9, whe-
reby the conducting rolls 3a and 3b co~er the distance Bl at a
constant height abo~e the recei~ing conveyor. As the connecting
rod mo~es along the circumference of the dri~e wheels, equalling
the distances b2, the wheel 7 mo~es o~er the upwards bended end
of the guide 9, whereby the output end of the pendulum describes a
corresponding arched path o~er the distance B2. The position of
the guide 9 is determined by the desired kinetic geometry. The
oscillating point 22 of the pendulum is displacable along the line
of the central pendulum motion and the recei~ing con~eyor 1 of the
primary web is mounted on bearings by articulation in order to be
able to ~ertically follow the motion of the input end of the
pendulum.
Figure 3 shows another preferred embodiment of the pendulum of the
in~ention. The lower end of an arm 20 is fixed on bearings outsi-
de the pendulum on the central line of the oscillating motion, and
its upper end is mounted on fork-bearings to the bearing point 8
of the connecting rod 6 on the pendulum. The bearing point 8 is
disposed to run in the fork 21 at the upper end of the arm. The
oscillating point 22 of the pendulum is ~ertically displacable
along the central line of the motion and the recei~ing con~eyor 1
of the primary web is mounted on bearings by articulation in or-
der to be able to follow the mo~ements of the pendulum ~ertically,
likewise as in the preceding case. As the connecting rod mo~es
o~er the horizontal area between the dri~e wheels the pendulum is
drawn into an angular position while the oscillating point mo~es
downwards until its reaches a stop 23 at the end of the constant
speed period. The stop pre~ents the oscillating point from
being further dispaced downwards and the pendulum is forced to
swing around the oscillating point P fixed by now. During this
retarding part of the motion the fastening point 8 is displaced
upwards in the fork 21 and thus does not pre~ent the pendulum
from rising along an arched line. During the subsequent accelera-
tion phase the pendulum swings down and the output end 10 descri-
bes the same arched line, while the fastening point 8 simulta-
neously is displaced towards the bottom of the fork 21. The same
motion is repeated in the opposite direction.
It is ad~antageous to dispose a spring between the central axis
and the arm 20 to pick up part oF the retardation and acceleration
forces generated by the oscillation of the pendulum.
The embodiments of figures 2 and 3 each show a pendulum motion
composed so that the horizontal or essentially horizontal output
motion coincides with the phase ha~ing a constant speed and the
rising respecti~ely sinking motion coincides with the phase ha~ing
retarded respecti~ely accelerated speed. The controlled trajectory
of the output end, de~iating from the arched trajectory, may of
course be adjusted to start at any point during the periGd of
constant speed b or the period of retarding or accelerating
motion b2.
As stated abo~e, the retardation and acceleration forces are less
than in prior used methods, partly due to the rising motion at
the sides of the output and partly due to a smaller pendulum ha-
~ing less mass.
It is ob~ious that a person skilled in the art is able to accomp-
lish the in~enti~e idea of a pendulum motion rising in the extreme
positions, ha~ing a constant rate of motion in the central phase
of the pendulum swing, in several different manners in addition to
the embodiments described abo~e.
