CROSS-REFERENCE TO RELATED APPLICATIONS
TECHNICAL FIELD
[0002] The technical field of reference of the present invention refers to the sector of
aerial cable transportation systems. Such specific technological application provides
for the presence of at least one transport unit in which passengers and/or goods are
transported. In these aerial cable systems, the transport units are moved in an aerial
mode along a predefined route by at least one supporting cable. The driving of the
units can be generated by a hauling cable or by a special motorization provided in
each unit. Along the route, structures are present for supporting portions of the
supporting cables known in the sector as "shoes". Such shoes are in particular present
both in the end stations and along possible intermediate pylon structures. In such
context, the present invention will deal with the problem of how to stably maintain
the supporting cable in the corresponding shoe also in the presence of adverse weather
events, such as for example strong lateral wind.
STATE OF THE ART
[0003] Aerial cable transportation systems are currently greatly widespread, and thus well
known to a person skilled in the art operating in this particular technical field.
In these systems, passengers and/or goods are transported along a route in special
transport units, for example cabins, chairs or the like. The route is delimited at
the opposite ends by two embarkation and disembarkation end stations, also known as
upstream and downstream stations. In particular, according to the present invention,
the term "aerial" refers to cable systems in which the transport units are moved along
at least one supporting cable in a raised position with respect to the ground below
(precisely aerial mode). The present invention refers to the aerial transportation
systems with one or with two supporting cables per branch. Therefore, for the sake
of simplicity in the continuation of the description, unless the contrary is explicitly
stated, the words "supporting cable" will also refer to the case where the supporting
cables are actually two. For the purposes of the present invention, the movement of
the units can be generated by a hauling cable to which all the units are coupled or
clamped, or by single motorizations present in the units, for example providing for
motorized trolleys that slide on the supporting cables. As is known, the hauling cable,
if present, is loop-sent between the end stations which are housed, for such purpose,
on special pulleys (of which at least one is motorized) and runs along the entire
route. On the contrary, the supporting cable is substantially fixed, i.e. is not moved
between the stations except for periodic maintenance phases. As already mentioned
in the foregoing, in an aerial cable transportation system of the type object of the
present invention, each transport unit comprises at least one trolley with rollers
which roll on the supporting cable.
[0004] An aerial cable transportation system as just described is very useful when the configuration
of the ground below, or other contour factors, does not make the classic land drive
practicable. For example, such aerial cable systems are used in the case where the
route to be travelled provides for significant altimetric jumps, also with considerable
slopes. Such route is typical of the zones of ski/mountain places and in such context
these systems are also called ski lifts. However, the present invention and the aerial
cable systems in general are also advantageously applied to urban contexts where the
ground transportation is congested.
[0005] As is known, it is often necessary to also provide, along the route, for intermediate
fixed structures between the end stations configured to support portions of the supporting
cable. A reason for requiring such intermediate fixed structures can be the excessive
distance between the end stations such not to enable arranging the cable in a single
span. Another reason can be the altimetric profile of the path in the case where there
are significant slope changes. Each intermediate fixed structure for supporting the
cable usually comprises a vertical supporting structure, such as a pylon or a tower,
on top of which devices for supporting the supporting cable are provided known as
"shoes". In particular, the shoe comprises a substantially U-shaped seat open at the
top for supporting the supporting cable. In systems with two supporting cables, the
seats are obviously two and parallel to each other. Along the shoe, the hauling cable,
if present, is instead supported by a series of rollers arranged below the seat of
the supporting cable.
[0006] With regard to what just described, the portion of supporting cable housed in the
seat of the shoe is less constrained because the trolley does not weigh on it and
it is thus freer to move. Vertical or longitudinal displacements are absorbed by the
system without any danger. On the contrary, a transversal displacement of the supporting
cable is very dangerous because it can bring the cable to come out of the relative
seat with consequent deviation of the cable from its theoretical line. There are adverse
weather conditions, such as strong transversal wind and/or mantle of ice on the cables
which, when detaching, can create a whiplash on the cable, whereby the supporting
cable can thus come out of its seat and derail. Although for such purpose the shoes
are laterally equipped with cable-catching devices, preventing such event is an object
pursued by all manufacturers in order to increase the safety of the system.
[0007] A first solution currently known for such purpose provides for installing along the
edges of the seat of the shoe fixed containment structures which effectively increase
the volume of the seat for offering greater shelter from the wind. However, this solution
is not optimal. Since the passage over the seat must in any case be free and without
obstacles for enabling the transit of the carriages, such fixed structures necessarily
have very reduced dimensions.
[0008] Based on the assumption that the problem of the supporting cable coming out of the
seat occurs most frequently during the stop of the system, when in fact there are
no circulating units which weigh on the cable anyway blocking it in some manner, there
currently exists a second solution configured to act only during such stop phases
of the system. This second solution provides for the presence of a movable arm pivotable
about an axis parallel to the axial direction of the supporting cable, which, like
a kind of level crossing, passes from a first position, in which it is substantially
transversal to the cable in contact with the seat closing the open upper end thereof,
to a second position in which it is substantially vertical and spaced apart from the
seat.
[0009] Also this second solution, although preferable with respect to the first one because
it does not obstruct the passage of the units during the operation of the system,
has some drawbacks. In fact, especially in systems with two supporting cables, such
arm must have a significant transversal length for closing both seats and such transversal
length translates into a considerable weight to raise (and maintain raised) rotating
about an axis parallel to that of the cables. From an engineering point of view, therefore,
such solution has constructive drawbacks which do not recommend its use.
[0010] Finally, it is specified that everything described thus far with regard to the shoes
present at the top of the pylons is also replicable at the disembarkation/embarkation
stations where there are exactly similar shoe structures for supporting the supporting
cables and where the same problems can thus occur. Furthermore, in the stations the
free space above the seats in which to rotate the aforementioned arms about an axis
parallel to that of the cables is often physically absent. Therefore, in many stations
the second solution described is not installable.
DESCRIPTION OF THE INVENTION
[0011] Based on such prior art, an object of the present invention is to manufacture an
innovative shoe assembly for supporting at least one supporting cable of an aerial
cable transportation system, wherein the shoe assembly is capable of solving the problems
of the prior art.
[0012] In particular, the object of the present invention is to provide a shoe assembly
for supporting at least one supporting cable of an aerial cable transportation system,
wherein the shoe assembly comprises an innovative safety device configured to hold
the supporting cable, in particular inhibit the transversal movements thereof, at
the relative seat during the stop phases of the system and which does not obstruct
the passage of the trolleys during the operation of the system.
[0013] In view of such objects, a shoe assembly that can be improved by the present invention
comprises:
- an inlet;
- an outlet;
- at least one seat extending from the inlet to the outlet for supporting the at least
one supporting cable;
- at least one safety device for holding or supporting the at least one supporting cable
at the corresponding at least one seat.
[0014] The above-mentioned elements are known per se to the person skilled in the art and
no further details are required for their understanding. Just for the sake of clarity,
it is noted that the terms "inlet" and "outlet" refer to the upstream and downstream
portions of the shoe, i.e. the portions at which the transport units enter and exit
the shoe. The seat supporting the supporting cable can per se have various different
shapes. However, usually and preferably the seat is substantially U-shaped with more
or less high side branches for making a groove which accommodates the supporting cable
and which is open at the top. The above list mentions "at least one seat" because
the present invention relates both to systems with one supporting cable as well as
to systems with two supporting cables. In the latter case, the seats are two and are
parallel to each other. Each seat obviously has a longitudinal development substantially
coinciding with the axis of the corresponding supporting cable. The features of the
safety device will be listed in the following. For the moment, it is emphasized that
"at least one safety device" means that a shoe can have one or more safety devices.
In case only one safety device is present, it is preferably located in the inlet zone
of the shoe. If two safety devices are present, these are preferably arranged in the
inlet zone and in the outlet zone of the shoe, respectively.
[0015] In such context, the main aspect of the present invention is to provide at least
one innovative safety device for holding the at least one supporting cable, i.e. substantially
inhibit the lateral or transversal movements thereof, at the corresponding at least
one seat, wherein each safety device (one or more if present) comprises:
- a supporting arm, preferably cylindrical, pivotable about a substantially vertical
axis A1 (or orthogonal to the axis of the supporting cable) passing at one end thereof
at the side of the at least one seat; and
- at least one blocking head coupled to the arm and configured to block (in the sense
of inhibiting at least the transversal movements) the at least one supporting cable
housed in the corresponding seat.
[0016] Therefore, according to the present invention, the safety device comprises a movable
arm (like a currently known prior art described in the foregoing) which, however,
in an innovative manner, is not pivotable about an axis parallel to the seat or to
the supporting cable but about an axis orthogonal to the seat or to the supporting
cable. In this manner, the movement of the arm is no longer of the level crossing
barrier type, but is of the door type in which the lifting of the arm is not provided.
Since it is not necessary to lift and keep elements raised (elements which could also
fall creating problems), no manoeuvring space for the arm above the seat is required.
[0017] Preferably, the supporting arm movable about the axis vertical to the supporting
cable is cyclically and selectively switchable between two different configurations,
in which:
- in the first configuration, the supporting arm is orthogonal to the axis of the cable
(or to the seat) and above the seat so that the at least one blocking head is located
at the at least one seat for blocking (inhibiting at least the transversal movements)
the at least one supporting cable; and
- a second configuration in which the supporting arm is parallel to and at the side
of the seat (rotation by 90° about the vertical axis) so that the at least one blocking
head (and the arm) does not represent an obstacle to the transit of the transport
units along the shoe assembly.
[0018] If the system comprises two supporting cables (and the shoe thus has two seats),
in a corresponding manner each safety device comprises a supporting arm provided with
two blocking heads which in the first configuration are located at the two seats.
[0019] If the arm supports only one blocking head, the latter is preferably movable along
the corresponding supporting arm for reaching in an adjustable manner the corresponding
seat and for compensating in an optimal manner transversal forces transmitted to the
head by the cable (in case of transversal wind for example).
[0020] If the arm supports two blocking heads, the latter are preferably independently movable
along the corresponding supporting arm for reaching in an adjustable manner the two
seats and for compensating in an optimal manner the different transversal forces transmitted
to the heads by the corresponding cables.
[0021] Preferably, the supporting arm is a cylindrical body so that the movement along the
arm of the blocking head(s) is a motion along the axis of said arm.
[0022] Preferably, the blocking head (or heads) is pivotable about the axis of the corresponding
(preferably cylindrical) supporting arm. This movement is useful because before rotating
the arm it is thus possible to lift the heads from the seats so that in the subsequent
rotation of the arm there is no danger of collision between heads and supporting cables.
[0023] Preferably, the blocking head (or heads) is substantially a U-shaped body so that
in the first configuration it forms an inverted U-shaped seat above the seat of the
cable capable of laterally blocking (holding) (inhibiting transversal movements) the
supporting cable as well as superiorly restricting the displacement thereof to a maximum
possible height. In fact, it is necessary to leave a vertical range of movement to
the cable so that it adapts to the different vertical loads that can be present.
[0024] Preferably, the blocking head (or heads) comprises a pair of facing idle rollers
which in the first configuration of the safety device are on opposite sides of the
supporting cable with vertical axes (orthogonal to the axis of the cable) for enabling
axial movements. An axial blocking of the cable would in fact be counterproductive
and would generate stresses and forces in the system.
[0025] Preferably, each blocking head can be provided with portions which in the first configuration
extend beyond the supporting cable and are in contact with (or face in proximity)
the structure of the shoe below the seat. Such contact portions advantageously create
the discharge points on the structure of possible transversal forces generated by
the cable (for example, by effect of crosswind). In fact, in this case the cable acts
on the rollers of the head and the latter discharges the strains onto the shoe only
at the contact portions preventing the propagation of strains in all of the mechanism.
Since each head is independently movable along the axis of the arm, such characteristic
is independent for each head so as to discharge in a different manner different forces
acting on the two supporting cables.
[0026] Preferably, the aforementioned contact portions can also be provided with heating
devices for melting or preventing the formation of ice on the heads in the contact
zone with the structure of the shoe.
[0027] Preferably, each blocking head comprises guiding portions configured to guide the
supporting cable into the seat also if partially not aligned with the theoretical
position. Such guiding portions are preferably lipped portions which in the first
configuration are on opposite sides of the seat which extend axially (parallel to
the axis of the cable) for a short section.
[0028] The present invention also extends to each aerial cable transportation system comprising
at least one shoe assembly as described in the foregoing and claimed. In general,
such a system comprises:
- at least one transport unit;
- at least one supporting cable for supporting the transport units;
- a driving device for driving the transport unit(s) on the at least one supporting
cable (for example a hauling cable or motorized carriages);
- at least one fixed structure of the station type for passenger embarkation and disembarkation
and/or of the pylon type.
[0029] In this context, the shoe assembly of the present invention can be provided in the
fixed structure in the form both of a station and/or of pylons.
[0030] Finally, the present invention also refers to the method for operating the aforementioned
aerial cable transportation system, wherein the method comprises the steps of:
- a) providing such a system;
- b) during the hours of operation of the system, switching the at least one safety
device into the second configuration (arm parallel to the cable and at the side of
the seats);
- c) during the stop of the system, switching the at least one safety device into the
first configuration (orthogonal arm above the seats).
LIST OF THE FIGURES
[0031] Further features and advantages of the present invention will become apparent from
the following description of a non-limiting example embodiment thereof, with reference
to the figures of the accompanying drawings, wherein:
- Figure 1 schematically shows a portion of an aerial cable transportation system that
can be improved with the present invention;
- Figure 2 shows the enlargement of the portion indicated by reference numeral II in
Figure 1;
- Figure 3 shows a portion of the system of Figure 2 in which a safety device is provided
according to an embodiment of the present invention;
- Figures 4-6 show the safety device of Figure 3 in different configurations of use;
- Figure 7 shows an enlargement of the safety device in the configuration of Figure
3;
- Figures 8-10 show different views and details of the safety device of Figure 3.
DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
[0032] Referring to the attached figures, Figure 1 schematically discloses a portion of
an aerial cable transportation system indicated as a whole by reference numeral 1
and which can be improved thanks to the present invention. In such non-limiting example,
the aerial cable system 1 comprises cables (indicated in Figure 1 in general by reference
numeral 2) and a passenger embarkation and disembarkation station 14 is visible. This
example comprises two parallel branches characterizing an ascending branch and a descending
branch of the system. The arrows A and B in Figure 1 indicate precisely the driving
directions of the ascending and descending branches. Figure 1 illustrates one of the
many transport units 3 present in the system, which are arranged one after the other
along both the ascending and descending branches. In the illustration of Figure 1,
a first transport unit 3 is at the station 14 inside which the transport units 3 are
usually disengaged from the cables 2. The second transport unit 3 shown in Figure
1 is travelling on the ascending branch and is arranged between the station 14 and
a first intermediate supporting fixed structure 15 in the form of a pylon 16. The
function of the pylons 16 arranged between the stations is to divide the cables into
distinct spans. Already in Figure 1 it is possible to note that the transport unit
3 of the shown example comprises a cabin 17 at the bottom and a supporting arm 18
(or suspension arm) at the top which connects it to the cable 2. Reference numeral
19 in Figure 1 schematically shows the device that connects the supporting arm 18
to the cable 2, in Figure 2 it will be described in greater detail in the form of
a trolley. In Figure 1, it is finally possible to note that a shoe assembly 4 for
supporting the cable 2 is present at the top of the pylon 16. Although Figure 1 shows
a system with several transport units, the present invention also extends to systems
with a single transport unit and/or systems in which the cabin or cabins travel in
both directions on the same branch of the system.
[0033] Figure 2 shows the enlargement of the portion indicated by reference numeral II in
Figure 1. In this figure, it is visible how the system 1 comprises two supporting
cables 2 and one hauling cable 13. However, for the purposes of the present invention,
the system can also comprise only one supporting cable, and the hauling cable can
also be replaced by similar means adapted to control the driving of the transport
unit. Figure 2 shows how the arm 18 is connected to the supporting cables 2 by means
of a carriage 19 provided with rollers 20 for rolling on the supporting cables 2.
Reference numeral 25 indicates the vice for the selective vicing to the pulling cable
13. The shoe 4 is only partly visible in Figure 2 (in Figure 1, the inlet portion
5 and the outlet portion 6 are visible very schematically). As is visible in Figure
2, along the shoe 4, the supporting cables 2 are housed at suitable U-shaped seats
on the upper end of the shoe 4 while the hauling cable 13 is housed along a series
of rollers 21 placed at a lower height. Therefore locally, the cable 2 can perform
axial, vertical and transversal movements in which the latter are to be restricted
for safety reasons and for preventing the cable 2 from coming out of the seat.
[0034] Figure 3 shows a portion of the system of Figure 2 in which a safety device is visible
according to an embodiment of the present invention, i.e. an innovative device configured
to hold (when required) the supporting cable in the seat of the shoe. In this example,
the seats (indicated by reference numeral 7) are two and parallel for housing the
two supporting cables 2. The development of the seats 7 or the axis of the supporting
cables 2 defines a longitudinal direction. Reference numeral 8 in Figure 3 indicates
an example of an innovative safety device according to the present invention. As is
visible in this figure, the safety device 8 comprises a substantially cylindrical
arm 9 having an axis A2 which supports two blocking heads 10. In the configuration
shown in Figure 3, the arm is arranged orthogonal to and above the seats 7 and the
heads 10 are at the seats 7 for holding the cables 2 in the seats 7. Such configuration
is the one which is imposed on the device 8 during the downtime phases of the system
1. In the phases of use of the system, the passage over the seats must obviously be
free so as not to create obstacles to the transit of the transport units.
[0035] Figures 4-6 show subsequent steps in which the safety device of figure 3 is in different
configurations for passing from the position of Figure 3 to a position in which it
frees the seats. In Figure 4 it is visible that the first controlled movement is the
rotation by 90° of the heads 10 about the axis A2 of the arm 9 so that the heads 10
no longer act on the cables 2. In Figure 5 it is visible that the second controlled
movement is the rotation of the arm 9 about the vertical axis A1 at one end thereof
placed at the side of the seats 7. In Figure 6 it is visible that the last controlled
movement is the rotation by 90° (in a direction opposite to that of Figure 4) of the
heads 10 about the axis A2 of the arm. The final outcome of these three rotations
brings the arm 8 and the heads 10 to be arranged at the side of the seats 7 parallel
to the cables 2 so as to reduce to the minimum the required bulk and so as not to
obstruct the passage of the carriages. Reference numeral 22 in these figures indicates
the motorization that controls these rotations.
[0036] Figure 7 shows an enlargement of the safety device in the configuration of Figure
3 and allows appreciating how the heads 10 are made. Each head comprises a base coupled
to the arm 9 and a free end shaped so that in the first configuration it forms an
inverted U-shaped seat over the seat 7 of the shoe 4. Reference numeral 23 indicates
a stop for blocking the rotation of the heads 10 in the correct position and reference
numeral 11 indicates idle rollers which in such configuration have vertical axes for
allowing axial movements of the cable 2.
[0037] Figure 8, and the enlarged detail of Figure 9, show a front view of the assembly
and allows seeing how the heads 10 do not allow the transversal coming out of the
cables 2. The arrows F1 and F2 in Figure 8 indicate that each head 10 is independently
movable along the arm 9 (along the axis A2) while reference numeral 12 in Figure 9
schematizes portions of the heads close to or at the structure of the shoe which are
heating devices (for example of the electric resistance type) suitable for preventing
the formation of ice on the heads 10 in the contact zone with the structure of the
shoe 4. These elements 12, which can also not be of heated type, also act as discharge
points for discharging the transversal forces coming from the supporting cable 2 onto
the shoe 4, thus preventing the forces from passing through the entire mechanism.
In fact, in case of transversal forces, the supporting cable 2 acts against the rollers
11 of the heads 10, which discharges these strains onto the shoe 4 only at the contact
elements 12. Such capability is offered by both heads in an independent manner since
they are independently movable in the direction of the axis A2 of the arm (a movement
which also enables absorbing geometric tolerances).
[0038] Finally, Figure 10 allows seeing the presence of lipped portions 24 which protrude
from the heads 10. In the first configuration, such portions 24 have an axial development
parallel to the cable 2 and act as guiding elements for directing the cable 2 into
the heads 10.
[0039] It is evident that modifications and variations can be made to the invention described
herein with respect to the example shown in the figures. In fact, the main aspect
of the present invention lies in the innovative safety device with movable arm as
claimed.
1. A shoe assembly for an aerial cable transportation system (1) comprising at least
one supporting cable (2) and at least one transport unit (3) moved on the supporting
cable (2); wherein the shoe assembly (4) comprises:
- an inlet (5);
- an outlet (6);
- at least one seat (7) extending from the inlet (5) to the outlet (6) to support
the at least one supporting cable (2);
- at least one safety device (8) to hold the at least one supporting cable (2) at
the corresponding at least one seat (7);
characterized in that
each safety device (8) comprises:
- a supporting arm (9) pivotable about a substantially vertical axis (A1) and passing
at one end thereof at the side of the at least one seat (7); and
- at least one blocking head (10) coupled to the supporting arm (9); in which
- in a first configuration, the supporting arm (9) is orthogonal to and above the
at least one seat (7) and the at least one blocking head (10) is at the at least one
seat (7) to hold the at least one supporting cable (2);
- in a second configuration the supporting arm (9) is parallel to and at the side
of the at least one seat (7) so that the supporting arm (9) and the at least one blocking
head (10) do not represent an obstacle to the transit of the at least one transport
unit (3) along the shoe assembly (4).
2. Shoe assembly as claimed in claim 1, wherein the shoe assembly (4) comprises a first
and second safety device (8) at the inlet (5) and outlet (6), respectively.
3. Shoe assembly as claimed in a claim 1 or 2, wherein the at least one blocking head
(10) is movable along the corresponding supporting arm (9).
4. Shoe assembly as claimed in any one of the preceding claims, wherein the at least
one blocking head (10) is pivotable about the axis of the corresponding supporting
arm (9).
5. Shoe assembly as claimed in any one of the preceding claims, wherein the at least
one blocking head (10) is substantially U-shaped such that at the at least one seat
(7) in the first configuration it laterally blocks the at least one supporting cable
(2) and superiorly restricts its movement to a maximum possible excursion.
6. Shoe assembly as claimed in claim 5, wherein the at least one blocking head (10) comprises
a pair of facing rollers (11) which in the first configuration are on opposite sides
of the at least one supporting cable (2) to allow axial movements.
7. Shoe assembly as claimed in any one of the preceding claims, wherein the at least
one blocking head (10) comprises contact or facing portions (12) proximate to a structure
of the shoe assembly (4) inferior to the seat such that lateral forces transmitted
by the cable (2) to the head (10) are discharged to the shoe assembly (4) only at
the contact portions (12).
8. Shoe assembly as claimed in claim 7, wherein contact portions (12) comprise heating
devices.
9. Shoe assembly as claimed in any one of the preceding claims, wherein the at least
one blocking head (10) comprises guiding portions (24) for the at least one supporting
cable (2) that in the first configuration are on opposite sides of the at least one
supporting cable (2) and extend axially.
10. Shoe assembly as claimed in any one of the preceding claims, wherein the shoe assembly
(4) comprises two parallel seats (7) to support two supporting cables (2) of an aerial
cable transportation system comprising two supporting cables; the supporting arm (9)
supporting two blocking heads (10) configured to block both supporting cables (2)
in the seats (7).
11. Shoe assembly as claimed in claim 10, wherein the two blocking heads (10) are independently
movable along the supporting arm (9).
12. Aerial cable transportation system; wherein the system (1) comprises:
- at least one transport unit (3);
- at least one supporting cable (2) to support the transport units (3);
- a driving device (13) for driving the transport units (3) on the at least one supporting
cable (2);
- at least one station (14) for passenger embarkation and disembarkation; and/or
- at least one structure (15) outside at least one station (14) ;
characterized in that
the at least one station (14) and/or the at least one structure (15) comprise a shoe
assembly (4) as claimed in any one of the preceding claims.
13. Method for operating an aerial cable transportation system for transporting passengers,
the method comprising the steps of:
a) providing a system (1) as claimed in claim 11;
b) during the hours of operation of the system (1) switching the at least one safety
device (4) to the second configuration;
c) during the stop of the system (1) switching the at least one safety device (4)
to the first configuration.