Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Insert element for guiding a rope or cable, rope or cable guide roller
and method of manufacturing an insert element
The present invention relates to an insert element for guiding a rope or
cable, a
rope or cable guide roller and a method for manufacturing the insert element.
Insert elements, sometimes also called linings, are used for rope pulleys or
also
for deflection pulleys of a ropeway, be it an aerial ropeway, a rail ropeway
or a
drag lift. The purpose of the insert elements is to support and guide a rope
or ca-
ble. Furthermore, insert elements also have a sound-absorbing and vibration-
damping effect. Due to the provision of such elements in sensitive systems
such
as ropeways, the wear of such insert elements must be monitored regularly in
or-
der to be able to replace them in good time before they fail. Such monitoring
is
usually carried out by trained personnel inspecting the insert elements. The
shape
of the insert element is measured using a gauge or caliper and compared with
an
initial state. Based on a deviation of the shape of the insert element from
its initial
state, a wear condition can be inferred. Due to the often difficult-to-reach
insert el-
ements (for example on the supports of a cable car), monitoring the insert ele-
ments is labor-intensive, difficult, time-consuming and therefore expensive.
It is therefore the object of the present invention to simplify the monitoring
of an in-
sert element.
This object is solved with an insert element with the features of claim 1,
with a
rope or cable guide pulley with the features of claim 13 and with a method for
manufacturing the insert element with the features of claim 14. Preferred
embodi-
ments are given in the dependent claims.
According to one aspect of the invention, an insert element for guiding a rope
or
cable, in particular for a cableway installation, is provided, comprising a
surface
layer with a first surface layer side which is designed to come into contact
with a
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rope or cable to be guided, and a second surface layer side opposite the first
sur-
face layer side, and an indicator element which is arranged on and/or in the
sur-
face layer, and wherein the indicator element is designed to indicate a state
of
wear of the insert element.
According to one aspect of the present invention, the insert element can also
be
used in pulleys for lifts, elevators, cranes, etc. Basically, wherever a cable
or rope
is guided, runs along or is deflected. The invention also relates to so-called
wear
strips, which can be provided as lockable strips instead of one-piece, closed
rope
pulley insert elements. For example, such wearable bands can protect a rope or
cable from direct contact with a building or other structures. The rope or
cable may
be a load-bearing structure. In particular, the cable or cord may be non-
current-
carrying (i.e. power supply) elements. Such a dual function would be
counterpro-
ductive, as a cable used for power supply should not be used to carry a load
at the
same time. Nevertheless, test currents or similar can be conducted through the
ca-
ble or rope.
According to one aspect of the invention, insert elements, linings or linings
for rope
pulleys protect the rope or cable on the one hand and the rope pulley itself
or ra-
ther the usually metallic rope pulley sheaves that form it on the other.
Furthermore,
the bearing of the rope pulley and the supporting structure can also be
protected.
Furthermore, insert elements can also provide increased comfort when guiding
the
rope through a pulley by ensuring mechanically and acoustically quiet running.
For
this purpose, the insert element can be made of a softer and/or more elastic
mate-
rial than the pulley on which the insert element can be provided. Accordingly,
the
insert element can be made as a one-piece ring, for example from an elastomer
or
rubber. The insert element can be realized with or without flexible textile
fabric or
flexible wire mesh inserts. For high loads, the insert element can be made of
a
plastic, which can comprise polyurethane as the base polymer and can belong to
the category of thermoplastics or thermosets.
In contrast to the prior art, with the insert element according to the
invention it is
not necessary for a person to be in the immediate vicinity of the insert
element in
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order to check the state of wear of the insert element. Rather, it is
sufficient for the
insert element to be inspected from a distance, since the indicator element
can be
used to easily recognize the state of wear of the insert element. For example,
when used in ropeway systems, it may be sufficient to inspect an insert
element
from the ground, for example using binoculars, and thus obtain immediate infor-
mation about the state of wear. This can significantly reduce the time
required for
inspection, so that the wear condition of an insert element can be checked,
for ex-
ample, as it passes by during an operating run. In this way, the previously
known
time-consuming and risky work of checking the insert elements can be reduced
or
avoided and at the same time it can be ensured that the state of wear can be
ob-
jectively determined independently of the person carrying out the inspection
thanks to the objective display by the indicator element. This ensures that
the in-
sert element is always replaced at the same time. In contrast, purely visual
and in-
dividual inspection by a person does not guarantee that several insert
elements
are assessed objectively at the same time. Consequently, by using the insert
ele-
ment according to one aspect of the present invention, replacement intervals
of
the insert elements can be standardized.
The insert element can be a separate part and designed to be fixed in a
roller. The
roller, in turn, can be held rotatably on a structure such as a support. For
example,
the pulley can be rotatably mounted on the structure by means of a plain
bearing
or roller bearing. A rope or cable can be placed on the insert element and sup-
ported and/or guided by it. A cable guide direction can designate the
direction in
which the cable to be guided extends. The insert element can also be designed
to
protect the cable against lateral displacement transverse to the cable guide
direc-
tion. For this purpose, the insert element can have a lower strength than the
pul-
ley. In other words, the insert element can be formed from an elastic material
that
at least partially surrounds the cable to be guided. In order to improve a
guiding
property, the insert element can at least partially adapt to the shape of the
rope to
be guided.
Preferably, the insert element is designed as a single piece. In other words,
the in-
sert element cannot be disassembled into its components in a non-destructive
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manner. This can ensure high stability and simple manufacture of the insert
ele-
ment. In particular, with a one-piece or integral insert element, a defined
position-
ing (for example during a central production of the insert element) is
ensured, so
that the indicator element always has the same relative position, for example
to
the surface layer, with several insert elements. This can ensure a consistent
deter-
mination of wear on the insert element.
The surface layer can be a volume layer that extends in all three spatial
directions.
In particular, in a cross-section transverse to the direction in which the
cable is
guided, the surface layer can have a first surface layer side and a second
opposite
surface layer side. A surface of the surface layer on the first surface layer
side and
a surface of the surface layer on the second surface layer side can be many
times
larger than the side surfaces of the surface layer. The first side of the
surface layer
can have such a shape that the rope or cable can be reliably guided through
the
insert element. To this end, the first surface layer side can, for example,
have a
shape that is complementary to the rope or cable to be guided. Preferably, the
first
surface layer side has such a shape that the rope is at least partially
accommo-
dated in the surface layer. For this purpose, the surface layer can be
recessed on
the first surface layer side, for example, and/or have an area that is formed
from a
different (e.g. softer) material.
The indicator element can be influenced and/or changed by an operation (i.e.
by
the contact between the rope and the surface layer and/or the indicator layer)
in
such a way that a wear condition of the insert element, in particular of the
surface
layer, can be indicated by the indicator element (for example a condition of
the in-
dicator element). The indicator element can, for example, be a further layer
that is
arranged, for example, on the second surface layer side of the surface layer.
The
indicator element can then become visible as a result of wear on the surface
layer,
so that it can be quickly and easily determined from the outside looking at
the first
surface layer side that the surface layer or the insert element is in a
certain state of
wear. In the case of a ring-shaped core element, for example, the state of
wear
can be determined by looking at the outside in the radial direction of the
core ele-
ment (i.e. the contact side between the core element and the rope or cable).
For
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this purpose, the indicator element can, for example, have a different color
from
the surface layer. For example, the surface layer can be black and the
indicator el-
ement white. This ensures that the high contrast makes it quick and easy to
recog-
nize that the indicator layer has come into contact with the surface of the
core ele-
ment.
According to a further aspect of the present invention, the indicator element
can be
a strip which is provided on the first surface layer side of the surface layer
at least
in the region in which the rope is guided through the surface layer. For
example,
the indicator element can be a strip-like element which is located
transversely to
the direction in which the rope is guided and/or along the direction in which
the
rope is guided in or on the first side of the surface layer. In this case, the
indicator
element can also have a different color from the surface layer. During
operation,
the surface layer and the indicator element can be abraded. In this case, the
indi-
cator element can have a lower material thickness than the surface layer, so
that
at some point during abrasion the indicator element has disappeared (i.e. is
no
longer visible), so that when viewed on the first surface layer side it can be
recog-
nized whether the indicator element is still present there or not.
Furthermore, the
indicator element or the indicator elements may have a tapering or widening
shape
pointing away from the first surface layer side. The visible indicator element
can
thus be thicker or thinner depending on the wear. The indicator element can
thus
indicate whether and/or to what extent the surface layer is worn. Particularly
in the
embodiment in which the indicator element extends transversely to the rope
guide
direction, it is easy to recognize in which area of the first surface layer
side a par-
ticularly large abrasion by the rope or cable has taken place. In this way, it
is also
possible to draw conclusions about an operating condition (for example,
eccentric
guidance of the rope, uneven loading of the core element, etc.). As a result,
opera-
tion can be further optimized and safety increased.
Preferably, several indicator elements can be provided in or on the surface
layer.
For example, several indicator elements can be provided as layers parallel to
the
first surface layer side in a way that builds on one another. Each indicator
layer
can have a different color. It is conceivable, for example, that the indicator
element
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closest to the first surface layer side has a green color, the next indicator
element
has an orange color and the next indicator element has a red color. In the
present
embodiment, the insert element can therefore have a total of three indicator
ele-
ments, each of which is designed as a separate layer. During operation, the
sur-
face layer is then at least partially worn away first, so that the first
(green) indicator
element becomes visible. The indicator element can thus indicate that the
surface
layer is already worn, but that further operation of the insert element is
still possi-
ble (by the green color of the first indicator element). If the first
indicator element is
also worn, the second indicator element (yellow layer) appears and indicates
that
the insert element will soon be worn and needs to be replaced. As soon as the
red
indicator element becomes visible, the indicator element indicates that the
insert
element now needs to be replaced. Similarly, the insert element can have a
large
number of different layers as indicator elements so that close monitoring of
the in-
sert element is possible. It is also conceivable that the indicator element
extends
variably relative to the first surface layer side. In this way, a visible
pattern can be
created on the first side of the surface layer when the surface layer is worn.
The
pattern can change depending on the sealing state. For example, the indicator
ele-
ment can extend in a wavelike manner relative to the first side of the surface
layer.
The variable arrangement of the indicator element means that a state of wear
can
only be detected by specialist personnel and/or image recognition systems and
not
by passengers or visitors. This prevents untrained persons from
misinterpreting
the indicator element.
On the one hand, the above insert element reduces the potential danger for the
personnel who have to inspect the insert elements, and on the other hand it re-
duces the effort involved in determining the wear of the insert element. For
exam-
ple, the insert element can be checked from a certain distance during an opera-
tional journey.
Preferably, the indicator element covers the first surface layer side and/or
the sec-
ond surface layer side at least partially or in sections.
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In the case where the indicator element is designed as a volume layer, the
indica-
tor element can cover the surface layer at least in the area where the rope or
cable
comes into contact with the surface layer. In other words, in this case the
indicator
element can be arranged on the first side of the surface layer. Alternatively,
or ad-
ditionally, the indicator layer can be provided on the second surface layer
side (i.e.
on the side of the surface layer facing away from the rope or cable) and
extend
over the second surface layer side. In this case, the indicator layer only
appears
when the surface layer is worn. Alternatively, or additionally, the indicator
layer can
also cover the first side of the surface layer and/or the second side of the
surface
layer in sections. In this case, the indicator element can be arranged as
strip ele-
ments (e.g. transverse to or along the rope guide direction). The indicator
element
can thus be arranged depending on the use of the insert element. For example,
a
sectional arrangement of the indicator element can be advantageous in a case
where the cable or rope comes into contact with the surface layer in a
previously
known area. On the other hand, a flat arrangement of the indicator element can
be
provided in a case where it is not clear in advance where wear will occur. The
lat-
ter can be the case, for example, with large-area insert elements. This means
that
the insert element can always be provided appropriately for the intended use.
It is
also conceivable to provide the indicator element within the surface layer.
For ex-
ample, at half the material thickness of the surface layer. This means, for
example,
that a wear condition can be indicated when the insert element is half worn.
Con-
sequently, reliable monitoring of the expected service life of the insert
element can
be provided.
Preferably, the surface layer comprises SBR, NR, NBR, EPDM, CSM, BR and/or
FKM.
This means that the surface layer can have sufficient elasticity to ensure
that the
cable or rope is guided securely and that the necessary soundproofing and
vibra-
tion damping effects are achieved. Furthermore, the materials SBR (styrene-
buta-
diene rubber), NR (natural rubber), NBR (acrylonitrile-butadiene rubber), EPDM
(ethylene-propylene-diene rubber), CSM (hypalon), BR (polybutadiene rubber)
and/or FKM (fluororubber) are easy to process, so that the surface layer can
be
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CA 03231355 2024- 3- 8
produced easily and in a suitable form. In particular, the insert element can
be a
vulcanization product. In addition, the above-mentioned materials are
inexpensive
and therefore make the manufacturing process of the insert element efficient.
Fur-
thermore, the surface layer may comprise a mixture of the above materials. The
above materials or blends thereof may each constitute the base polymer and may
be augmented by additives such as carbon black, etc. In this way, the desired
properties (such as color) that are required for the intended use of the
insert ele-
ment can be easily achieved.
Preferably, the indicator element comprises PE, PP, TPE, PA and/or PETP.
With the above materials, the indicator element can have suitable properties
in or-
der, on the one hand, to be able to suitably indicate the state of wear and,
on the
other hand, to have sufficient strength in order, for example, to guide the
rope or
cable safely and suitably in the event of contact with it and still indicate
the state of
wear of the insert element. In other words, the indicator layer can comprise
PE
(polyethylene), PP (polypropylene), TPE (thermoplastic elastomers), PA (polyam-
ides) and/or PETP (polyethylene terephthalate). Furthermore, the indicator ele-
ment can also comprise mixtures of the above materials. The above materials
could merely represent the base polymer and comprise further additives, such
as
carbon black and so on. Consequently, the indicator element can also be
suitably
adapted to the respective area of use of the insert element and have
sufficient
strength and resistance for long-term operation.
Preferably, the indicator element and the surface layer have different
properties,
such as in particular hardness, density, tensile strength, elongation at
break, abra-
sion, rebound elasticity, compression set, tear propagation resistance, glass
tran-
sition temperature, electrical conductivity and/or swelling.
The surface layer preferably has a Shore-A hardness of greater than 81 Shore.
In
contrast, the indicator element can have a Shore-A hardness of less than 80
Shore. It has been found that in the above-mentioned range, a particularly
high en-
ergy efficiency (especially with regard to the deformation of the insert
element) can
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CA 03231355 2024- 3- 8
be achieved when using the insert element in a guide roller for a cableway
system.
The fact that the indicator element has a lower hardness compared to the
surface
layer can ensure that the indicator element is eroded faster than the surface
layer
on contact with the rope or cable, so that a state of wear can be clearly and
easily
recognized even from a certain distance. The hardness can, for example, be de-
termined in accordance with DIN 53505, DIN EN ISO 868 or analogue.
The density of the indicator element is preferably lower than the density of
the sur-
face layer. Preferably, the density of the indicator element is less than 1.25
g/cm3
and the density of the surface layer is preferably greater than 1.25 g/cm3 .
This en-
sures that the wear condition of the insert element can be clearly indicated.
The
density can preferably be determined in accordance with the EN ISO 1183-1
standard. Preferably, the surface layer has a density in the range of 1.26
g/cm3 to
1.28 g/cm3 . This ensures that the weight of the insert element is in a
suitable
range for use in particular in conjunction with a pulley for a cableway
system. In
this case, particularly efficient operation of the pulley is possible.
The tensile strength can indicate the maximum mechanical tensile stress that a
material can withstand before it fails (e.g. tears). Preferably, the surface
layer has
a tensile strength of greater than 15 N/mm2 . In contrast, the indicator
element can
have a tensile strength of less than 15 N/mm2 . In this range, it can be
ensured
that the surface layer has sufficient resistance to failure. This can ensure
the re-
quired safety when guiding a rope or cable. In contrast, a lower tensile
strength is
sufficient for the indicator element, as this is only partially used, if at
all, to guide
the rope or cable. The areas shown above can be used to form a particularly
effi-
cient insert element, as the indicator element can be equipped with a lower
tear re-
sistance and is therefore less expensive.
Elongation at break can be a characteristic value that indicates a permanent
elon-
gation of a component in relation to its initial length when the component is
loaded
by a force. In other words, the elongation at break can indicate the
deformation ca-
pacity of a component. Preferably, the elongation at break can be determined
in
accordance with the DIN 53504-S2 standard. Preferably, the surface layer has
an
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elongation at break of at least 120%. In contrast, the indicator element has
an
elongation at break of at least 200%. This ensures that safe operation of the
insert
element is guaranteed without the risk of premature failure, even if the
indicator el-
ement is involved in guiding the rope or cable.
Abrasion (also known as abrasion or erosion) can refer to a loss of material
on the
surface of components. Abrasion can be caused by mechanical stress, such as
friction, and/or by environmental influences. Very small particles can usually
be
produced when material is removed from the component. In materials science,
abrasion can also be referred to as wear. Preferably, the abrasion is
determined
as a volume according to the ISO 4649 - Method A standard. Preferably, the sur-
face layer has an abrasion of greater than 160 mm3 . In contrast, the
indicator ele-
ment has an abrasion of preferably less than 160 mm3 . Furthermore, the
abrasion
of the surface layer and the indicator element can be limited to a maximum of
200
mm3 . This can also ensure permanent operation of the insert element. This is
par-
ticularly advantageous if the indicator element is located in the material of
the sur-
face layer. Furthermore, the upper limit on abrasion can prevent excessive
mate-
rial from entering the environment.
The rebound resilience can be used to assess the elasticity behavior of
elastomers
under impact stress. Preferably, the surface layer has a rebound resilience of
at
least 40 %. In contrast, the indicator element preferably has a rebound
resilience
of less than 40 %. Preferably, the rebound resilience is determined in
accordance
with the DIN 53512 standard. Furthermore, the surface layer and the indicator
ele-
ment can have a rebound resilience of at least 25 %. This ensures that the
rope or
cable is guided securely on the insert element without bouncing off it, thus
ena-
bling the rope to be guided securely.
Compression set is a measure of how elastomers behave during prolonged con-
stant compression set and subsequent relaxation. Preferably, the compression
set
is determined over 24 hours at 70 C and 20 % deformation in accordance with
the
ISO 815 type B standard. Preferably, the surface layer can have a compression
set of less than 20%. In contrast, the indicator element can have a
compression
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CA 03231355 2024- 3- 8
set of at least 20%. This ensures that the rope is guided securely even if the
insert
element is subjected to prolonged loading. Furthermore, it can be ensured that
the
indicator element reliably indicates a state of wear of the core element. A
particu-
larly durable core element can be provided in the above area.
The volume resistivity can be a measure of how well a component conducts elec-
trical current. The volume resistivity results from the measured volume
resistivity
multiplied by the measurement area divided by the sample length. Preferably,
the
volume resistivity is determined in accordance with the IEC 62631-3-2
standard.
Preferably, the surface layer has a volume resistivity of less than 6.7*1013
Ohm*cm. In contrast, the indicator layer preferably has a volume resistivity
of at
least 5 times 1014 Ohm*cm. This ensures that the indicator element is
electrically
non-conductive. This is advantageous if, for example, a conductive surface
layer is
used (e.g. with a volume resistivity of 1.9 times 105 Ohm*cm). In this case,
it is
possible to detect when the rope is in contact with the insert element only
via the
indicator element, and thus the electrical resistance increases significantly.
In
other words, a voltage can be applied to a rope or cable to be guided, which
can
be measured at a conductive surface layer. As soon as the surface layer is
worn
and the rope or cable is only in contact with the insert element via the
indicator el-
ement, an increased resistance can be detected. This allows the conclusion to
be
drawn that the surface layer is worn. Alternatively, this configuration can
also be
designed the other way round, so that the surface layer is non-conductive and
the
indicator element establishes an electrically conductive connection between a
de-
tector element (e.g. sensor element) and the cable to be guided. In this case,
it is
also possible to detect (in this case by establishing an electrical
connection) that
the surface layer is worn.
The tear propagation resistance can for example be determined in accordance
with ONORM C 9446:2007 02 01. The tear propagation resistance can be the
maximum force required to produce a crack in the material and can be related
to
the thickness of the material. A ratio of the tear propagation resistance of
the sur-
face layer to the tear propagation resistance of the indicator element can
prefera-
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bly be in a range of 0.7 to 1.9. It has been found that in this range, the
indicator el-
ement can be reliably held in the surface layer or on the surface layer, even
if the
surface layer is already largely worn. This ensures that the indicator element
relia-
bly indicates the state of wear even if the surface layer is worn to an
advanced
stage. Furthermore, the rope or cable can be reliably supported by the
indicator el-
ement even if the wear of the surface layer is already in an advanced stage.
The glass transition temperature can preferably be determined in accordance
with
the ISO 11357-2 standard. Preferably, the surface layer has a glass transition
tern-
perature of at least 70 C. In contrast, the indicator element can have a lower
glass
transition temperature. The glass transition temperature can be a temperature
above which a polymer changes to a rubbery to viscous state. In other words,
if
the glass transition temperature is exceeded, the surface layer can abruptly
change its properties, which are necessary for guiding a rope. It is therefore
ad-
vantageous if the surface layer has a sufficiently high glass transition
temperature
to ensure that the rope is guided safely through the core element even during
con-
tinuous operation. In contrast, the indicator element can have a lower glass
transi-
tion temperature, as the indicator element is not primarily responsible for
guiding
the rope, particularly in the case where the indicator element is only
provided in
sections or partially on the surface layer. Consequently, an efficient
interaction of
the surface layer and the indicator element can be achieved. Furthermore, due
to
the above determined glass transition temperature of the surface layer, the
insert
element can also be used with fast rotating pulleys (i.e. with higher heat
genera-
tion during operation).
Preferably, the indicator element comprises a fabric, at least a thread,
fluorescent
material, colored liquid, in particular ink, and/or a film.
The fabric can, for example, be a textile surface fabric that comprises at
least two
thread systems and is provided extensively in the surface layer or on the
surface
layer. If the surface layer is worn to such an extent that the fabric is
visible from
the outside, the wear condition of the insert element can be determined. The
fabric
can also be made of wires, cord or other elements, for example. Preferably,
the
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fabric also has a stabilizing effect, so that radial forces acting on the
insert element
can be absorbed by the fabric. This allows the insert element to be thinner,
which
can save production costs. Furthermore, the insert element can also be used
for
small rolls.
The at least one thread can be arranged in or on the surface layer in such a
way
that the thread comes to light (i.e. becomes visible from the outside) when
the sur-
face layer is worn. This allows conclusions to be drawn about the state of
wear of
the insert element. The thread can be arranged straight or curved in the
surface
layer. Preferably, the thread can have a distinctive color (for example, a
lighter
color than the surface layer) so that it can be easily identified even from a
greater
distance.
The fluorescent material can be used to detect the state of wear of the insert
ele-
ment. Furthermore, the fluorescent material can have the additional property
that
an emission of light takes place after excitation of the material. Photons can
be
emitted when light is emitted. For example, an insert element to be examined
can
be irradiated with a light source so that any fluorescent material
recognizable on
the surface emits light accordingly. This means that an insert element can be
checked for wear even in the dark. This can simplify the maintenance of an
insert
element. The fluorescent material can be applied to or in the indicator
element in
the form of paint or lacquer. The light source used to excite the fluorescent
mate-
rial can be a UV light source, for example. In principle, any fluorescent
material is
suitable for use in conjunction with the indicator element.
The colored liquid can for example be arranged in capsules in the surface
layer. In
the event of wear or abrasion of the surface layer, these capsules can be dam-
aged so that the liquid comes to the surface of the insert element. This makes
it
easy to recognize that the insert element has reached a certain state of wear.
In
this embodiment, it is advantageous that even with minor abrasions, the liquid
is
distributed over a large area of the surface of the insert element, so that
even with
minor damage to the surface layer, it is easy and straighfforward to recognize
that
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a certain state of wear has been reached. The capsule with the liquid can be
ar-
ranged in the surface layer at a certain distance in the radial direction from
the first
surface layer side. Furthermore, differently colored liquids can also be
provided
depending on a position in the insert element (for example, depending on a dis-
tance from the first surface layer side). Thus, the different colors appearing
on the
surface of the insert element can be used to determine how far wear of the
insert
element has progressed.
The foil can be a plastic foil or an aluminum foil, which is arranged parallel
to the
first surface layer side in the insert element. If the surface layer is worn,
the foil
can be partially or completely exposed and thus indicate the wear condition of
the
insert element. It is also conceivable to mix an aluminum powder into the
surface
layer, which becomes visible when the surface layer is worn. This makes it
particu-
larly easy to realize the indicator element.
Preferably, the insert element comprises at least one conductivity sensor,
which is
designed to detect a voltage applied to a rope or cable passing through the
insert
element.
This embodiment can be realized in two ways: Firstly, the surface layer can be
an
insulating material, as is the case with aerial tramways, for example. In this
case,
the cable running through the insert element is used to transport a signal
(e.g. a
telephone signal). If the insert elements were not insulated, this signal
would be
disturbed and would not reach the receiver in a suitable form. In contrast,
the indi-
cator element can be designed to be conductive. If the surface layer is rubbed
off
to such an extent that the cable passing through the insert element comes into
contact with the indicator element, a circuit can be closed and the signal con-
ducted through the cable can be detected by the sensor on the insert element.
This means that remote monitoring can also be used to determine whether an in-
sert element is worn or not. Furthermore, this system can also detect the
exact po-
sition of the worn core element in a larger system. On the other hand, it is
possible
that the surface layer is designed to be conductive and the indicator element
is
provided in the surface layer or on the second side of the surface layer and
has an
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CA 03231355 2024- 3- 8
insulating property. If the surface layer is worn, tension can be transmitted
from
the rope passing through the insert element to the insert element as long as
the
surface layer has a certain thickness. If the surface layer is worn and the
abrasion
is so great that the rope is in contact with the indicator element (e.g. with
the indi-
cator layer), the rope is insulated and tension can no longer be measured. In
this
case, it is also possible to detect that the core element is worn.
Preferably, the indicator element comprises at least one metal rod and/or a
wire.
For example, the metal rod can be located in the surface layer at right angles
to
the direction in which the cable is guided. If the surface layer is worn or
abraded to
such an extent that the wire reaches the surface (i.e. the first side of the
surface
layer), it can be determined that the surface layer is worn. This offers the
ad-
vantage that no further abrasion is possible or at least greatly reduced by
the
metal rod, as the metal rod has a significantly higher strength than the
surface
layer. For this purpose, the metal rod can be arranged in a predetermined
position
(i.e. at a predetermined distance from the first surface layer side) in the
surface
layer at which it is desired that the insert element is replaced. In this way,
a wear
limit of the insert element can be defined in a simple manner, which
nevertheless
allows continued operation of the insert element.
Similarly, a wire can be arranged in or on the surface layer and thus have a
similar
effect to the metal rod. Furthermore, different wires separated from each
other can
be arranged in different positions within the surface layer. For example, each
wire
can have a different distance from the first side of the surface layer. The
wires can
differ in color, for example. If the surface layer is abraded to such an
extent that a
wire comes into contact with the surface of the surface layer, the wire can be
rec-
ognized and a wear condition can be indicated. During further operation, the
wire
(in contrast to the metal rod) can be worn further, i.e. removed from the
insert ele-
ment (until the next wire appears). Different wear states can be indicated by
differ-
ent colors of the different wires. It is also conceivable to apply a voltage
to each
wire and measure this separately for each wire. If the applied voltage can be
measured, it can be assumed that the insert element is still intact. If, on
the other
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CA 03231355 2024- 3- 8
hand, no voltage can be measured on one or more wires, it can be assumed that
these wires have already been removed from the insert element by reducing the
material thickness of the surface layer. Since the distance of the individual
wires to
each other and to the first surface layer side is known, an abrasion depth or
a
state of wear can be precisely defined according to the intervals at which the
wires
are provided in the insert element. Furthermore, this wear condition can also
be
determined by remote and/or automated maintenance. This means that detailed
monitoring of a system, which for example comprises a large number of system
el-
ements, is easily possible. It is also conceivable to provide an automated
system
for monitoring the wear condition of at least one insert element. The
monitoring
system can, for example, automatically issue an alarm when a predetermined
wear condition is reached. This can ensure that a worn insert element is
detected
and replaced in good time.
Preferably, the insert element comprises a plurality of indicator elements
which are
distributed in a radial direction of the insert element, and wherein each
indicator el-
ement has different properties.
The radial direction of the insert element can refer to an insert element that
has a
ring-like shape. Nevertheless, the insert element can also be a flat body. In
any
case, the radial direction may be a direction that is orthogonal to the first
overlay
side and extends to the second overlay side. The provision of several
indicator el-
ements is similar to the provision of different wires at different distances
from the
first cladding layer side in the above embodiment. In other words, different
wear
conditions can also be realized with other indicator elements by providing the
indi-
cator elements at different distances from the first surface layer side.
Preferably, a ratio of the material thickness of the surface layer and the
material
thickness of the indicator element in a radial direction of the insert element
is in a
range from 0.01 to 0.7, preferably in a range from 0.07 to 0.5, more
preferably in a
range from 0.1 to 0.3.
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CA 03231355 2024- 3- 8
It was found that in a first area there is optimum interaction between the
surface
layer and the indicator element. This is particularly true if the indicator
element is
designed as an indicator layer. The first-mentioned area is particularly
advanta-
geous with regard to the occurrence of stresses between the two layers, as the
two layer thicknesses are in such a ratio to each other that no stress peaks
occur
at the interface between the surface layer and the indicator layer. This
ensures the
durability of the insert element.
In the second area mentioned, the advantage is that even if several indicator
ele-
ments are provided (in the second ratio specified above, the material
thicknesses
of all existing indicator layers are added together), sufficient cohesion of
all individ-
ual layers is ensured.
Furthermore, it was found that in the last defined area, a state of wear of
the insert
element is indicated long enough by the in the last area so that maintenance
per-
sonnel can take note of it. This means that a state of wear of the insert
element
can be reliably indicated over a sufficient period of time and can also be
reliably
detected.
Preferably, the insert element comprises a fabric layer which is designed to
absorb
radial forces, wherein a ratio of the material thickness of the surface layer
and the
material thickness of the fabric layer in a radial direction of the insert
element is in
a range from 0.8 to 9, preferably in a range from 1 to 8, more preferably in a
range
from 2 to 6.
The first area mentioned above offers the advantage that the insert element
can
be used in a wide range of applications. For example, the insert element can
also
be used in systems in which a large radial force acts on the insert element.
Even
in such a case, safe operation can be realized.
In the second area mentioned above, the fabric layer is just as thick as the
surface
layer or thinner. The advantage here is that an overall thinner insert element
can
be provided and sufficient abrasion reserves can be realized by the surface
layer.
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CA 03231355 2024- 3- 8
At the same time, the insert element offers sufficient resistance to absorb
radial
forces.
It was found that the latter area represents an optimum, particularly when
operat-
ing cable car systems. Here, the radial forces occurring in cable car systems
can
be sufficiently absorbed and yet a sufficiently thin insert element can be
provided
so that efficient operation is possible.
Preferably, the surface layer has on its first surface layer side a cross-
section
transverse to a cable or cable guide direction, a guide region and two
protective
regions adjacent to the guide region, wherein the guide region has a
depression
which is recessed by a depression spacing relative to at least one of the
shoulder
regions, and wherein a ratio of a width of both shoulder regions in the cross-
sec-
tion transverse to the cable or cable guide direction and the depression
spacing is
in a range from 0.2 to 5, preferably in a range from 0.4 to 3, more preferably
in a
range from 0.7 to 2.5. cable guide direction and the recess spacing is in a
range
from 0.2 to 5, preferably in a range from 0.4 to 3, more preferably in a range
from
0.7 to 2.5.
This means that the first side of the surface layer can be structured in such
a way
that the cable can be guided through the surface layer in a defined manner.
Pref-
erably, the recess is round and has the recess spacing as a radius. This
allows the
first side of the surface layer to be complementary to a cable or rope to be
guided,
which improves the guidance. The specified ratios indicate a ratio of the
depth of
the recess to a width of the insert element transverse to the cable guide
direction.
The first ratio offers the advantage that any type of rope or cable is
compatible
with the insert element without any problems. For example, even very thick
ropes
can be suitably guided through the insert element. Furthermore, the range of
use
of the insert element in the first area defined above is very large, so that
the insert
element can be used in a variety of applications. In the second range defined
above, there is the advantage that even in applications in which forces are
applied
to the insert element transversely to the radial direction of the insert
element and
to the direction in which the rope is guided, the insert element has
sufficient
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CA 03231355 2024- 3- 8
strength or resistance to such acting forces due to the shoulder areas, so
that per-
manent operation is possible. In other words, the force acting on the shoulder
ar-
eas depends on the depth to which the rope sinks into the recess of the insert
ele-
ment. Thus, the second area defined above provides optimum lateral stiffness
while at the same time efficiently guiding the rope. The last area defined
above of-
fers the advantage that an optimal lateral guidance property for the rope or
calf is
provided by the insert element, whereby the insert element can be realized
with
minimal use of material.
According to a further aspect of the present invention, there is provided a
rope or
cable guide pulley comprising an insert member comprising a surface layer
having
a first surface layer side adapted to come into contact with a rope or cable
to be
guided and a second surface layer side opposite the first surface layer side,
and
an indicator member arranged on and/or in the surface layer side, and wherein
the
indicator member is adapted to indicate a wear condition of the insert member,
and a bearing portion for rotatably supporting the rope or cable guide pulley.
Such a pulley can be used, for example, in cable cars, elevators, cranes etc.
to de-
flect and/or guide a rope or cable. The insert element can also be designed ac-
cording to one of the above insert elements.
According to a further aspect of the present invention, there is provided a
method
of manufacturing a core member for guiding a rope or cable, in particular
accord-
ing to any of the above aspects, the method comprising the steps of:
Provision of an indicator element,
Application of the indicator element in or on a surface layer, and
Vulcanization of the indicator element and the surface layer,
whereby the indicator element can indicate a state of wear of the insert ele-
ment.
Furthermore, the method can include a step of cutting or milling a groove into
the
first face of the surface layer. The groove can extend in the direction of the
cable
guide. The indicator element (for example a different colored tape) can be
inserted
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CA 03231355 2024- 3- 8
into the groove and then vulcanized together with the surface layer. In this
way,
the indicator element can be bonded to the surface layer. Preferably, the
indicator
element is located at the deepest point of the indentation in the surface
layer. The
recess can be designed in such a way that the rope or cable to be guided does
not
touch the deepest point of the recess at the start of operation of the insert
element.
The cable or rope can only come into contact with the deepest point of the
recess
and abrade the indicator element as a result of wear or abrasion of the
surface
layer. If the indicator element is no longer visible, it can be defined that a
certain
state of wear has been reached. For example, when the indicator element is no
longer visible, the insert element can be replaced.
The embodiment variants and advantages listed above in connection with the de-
vice also apply analogously to the method and vice versa. Individual features
of in-
dividual embodiments can be combined with each other to form new embodi-
ments. The advantages of the individual features then also apply to the new em-
bodiment. In the following, embodiments to be preferred are described in
detail
with reference to the figures. They show:
Fig. la schematic and perspective view of an insert element
according to an
embodiment of the present invention,
Fig. 2a cross-section of the insert element shown
in Fig. 1 transverse to
a cable guide direction,
Fig. 3a schematic surface view of an insert element according to a further
embodiment of the present invention,
Fig. 4a schematic surface view of an insert element
according to a further
embodiment of the present invention,
Fig. 5a schematic cross-section of an insert element of a
further embodi-
ment according to the present invention, and
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CA 03231355 2024- 3- 8
Fig. 6a schematic cross-section of an insert element
according to a further
embodiment of the present invention.
Fig. 1 is a schematic and perspective view of an insert element 1 according to
an
embodiment of the present invention. The insert element 1 according to the pre-
sent embodiment has a ring-like shape and is only shown in sections in Fig. 1
for
simplification. The insert element 1 has a surface layer 2. The surface layer
2 has
a first surface layer side 6, which represents an outer side of the surface
layer 2
(i.e. facing the environment), and a second surface layer side 7, which
represents
an inner side of the surface layer side 2. An indicator layer is provided on
the sec-
ond surface layer side 7 as an indicator element 3. Furthermore, the surface
layer
2 has a cable guide area 5 and two shoulder areas 4 on its first surface layer
side
6. The two shoulder areas 4 enclose the rope guide area 5 in their center. A
rope
or cable to be guided (not shown in the figures) comes to rest in the rope
guide
area 5 so that the rope or cable comes into contact with the surface layer 2.
The
cable guide area 5 has a recess 8, which is recessed radially inwards in
relation to
the shoulder areas 4. The cable is guided through the insert element 1 in a
cable
guide direction 10 (in Fig. 1 from right to left or from left to right). In
other words,
the cable can move in the cable guide direction 10. The insert element 1 can
also
move (i.e. rotate) according to the movement of the rope. For example, a
pulley on
which the insert element 1 is arranged can rotate. Guiding the rope can cause
the
surface layer 2 to wear, particularly since a relative speed between the rope
and
the core element is not equal to zero. The wear causes abrasion, which causes
the surface layer 2 to lose material. If the surface layer 2 is worn down to
such an
extent that the indicator layer 3 appears (i.e. is visible from the outside in
a surface
view of the core element), the state of wear of the core element can be
recognized
from the outside. Accordingly, it can be determined that the insert element 1
needs
to be replaced.
Fig. 2 is a section through the insert element 1 shown in Fig. 1 at right
angles to
the cable guide direction 10. In Fig. 2, the cable guide direction therefore
runs into
and out of the sheet plane. In Fig. 2, the recess 8 can be seen in the cable
guide
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CA 03231355 2024- 3- 8
area 5. It can also be seen that the indentation 8 has a radius that defines
the in-
dentation. Furthermore, the radial direction 20 and an axial direction 30 are
shown
in Fig. 2. The indicator layer 3 of the present embodiment is bonded to the
surface
layer 2 by vulcanization. This can ensure that there is sufficient cohesion
between
the surface layer 2 and the indicator layer 3.
Fig. 3 is a surface view of an insert element 1 according to a further
embodiment
of the present invention. In this embodiment, the surface layer 2 also has two
shoulder regions 4 and a rope guide region 5. However, in the present embodi-
ment, the indicator element is not arranged as an indicator layer on the
second
surface layer side 7 of the surface layer 2, but as strip-like elements which
extend
in the axial direction parallel to one another and transversely to the cable
guide di-
rection 10. The indicator elements 3 extend both in the shoulder areas 4 and
in the
rope guide area. This means that wear can be indicated over the entire width
of
the core element 1. In the present embodiment, the indicator elements 3 are lo-
cated on the surface of the core element 1 (i.e. on the first surface layer
side 6), so
that if the indicator elements 3 are no longer present, it can be concluded
that a
certain state of wear of the core element 1 has occurred.
In another embodiment not shown, further indicator elements are arranged
inside
the surface layer 2 in addition to the indicator elements 3 attached to the
surface.
The indicator elements 3 differ in their color. More precisely, the indicator
elements
3 that are arranged on the surface of the surface layer 2 (i.e. on the first
surface
layer side 6) differ from the indicator elements 3 that are arranged inside
the sur-
face layer 2. This means that different color coding can be used to easily and
readily identify how far the wear of the insert element 1 has progressed.
Fig. 4 shows a surface view of an insert element 1 according to a further
embodi-
ment of the present invention. The present embodiment largely corresponds to
the
embodiment shown in Fig. 3, with the difference that the indicator elements 3
now
run in the direction of the cable guide 10. In the present embodiment, one
indicator
element is arranged at the deepest point of the recess 8 in the cable guide
area 5
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CA 03231355 2024- 3- 8
and one indicator element 3 in each of the shoulder areas 4. This means that a
pe-
riodically occurring uneven load on the insert element 1 due to uneven wear of
the
indicator elements 3 can also be detected.
Fig. 5 is a cross-section through an insert element 1 according to a further
embod-
iment of the present invention. The embodiment shown in Fig. 5 essentially
corre-
sponds to the embodiment shown in Fig. 2, with the difference that the
indicator el-
ement 3 is not formed as an indicator layer, but as a plurality of capsules
contain-
ing a colored liquid. The capsules 3 are arranged at different depths within
the sur-
face layer 2. In other words, the capsules 3 are arranged at different
positions in
the radial direction 20 of the insert element I. If the surface layer 2 is now
worn by
a cable or rope, the capsules can be damaged and the liquid can escape to the
first surface layer side 6. The colored liquid can indicate that a certain
state of
wear of the insert element 1 has been reached.
Fig. 6 is a schematic cross-section of a further embodiment of the present
inven-
tion. The embodiment shown in Fig. 6 essentially corresponds to the embodiment
shown in Fig. 3, with the difference that the indicator element 3 comprises
wires
extending in the cable guide direction 10, which are arranged inside the
insert ele-
ment 1. The wires 3 are arranged at different distances from the first surface
layer
side 6 of the surface layer 2 and can thus indicate different wear states of
the in-
sert element 1 by the wires 3 coming to the surface on the first surface layer
side
6. In a further embodiment, a voltage can be applied to the wires 3 and
measured
by a sensor. Damage to a wire 3 (for example due to wear) can cause the
voltage
to change. In particular, each wire can be monitored individually and
separately.
This means that remote diagnosis can be used to detect the extent to which the
in-
sert element is worn.
The rope guide direction can also be referred to as the circumferential
direction for
round insert elements. In a further embodiment not shown, the indicator
element is
formed as a structure on the surface of the surface layer (i.e. on the first
surface
layer side 6). For example, the indicator element 3 is an indentation in a
rope
guide area 5 and if the indentation is no longer present, it can be concluded
that a
- 23 -
CA 03231355 2024- 3- 8
certain wear condition has occurred. In a further embodiment not shown, the
insert
element comprises, in addition to the surface layer and the indicator element,
a
fabric layer designed to absorb radial forces.
Reference sign list:
1 Insert element
2 Surface layer
3 Indicator element
4 Shoulder area
5 Rope guide area
6 First surface layer side
7 Second surface layer side
8 Deepening
10 Cable guide direction
Radial direction
Axial direction
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CA 03231355 2024- 3- 8
