[0001] The present invention relates to a switch for a cable transportation system for moving
transportation units along a given track.
[0002] Cable transportation systems of the above type are described in documents
CH 671,929;
AT 404,010;
US 5,582,109;
EP 687,607;
AT 405,269;
EP 1,077,167;
EP 1, 088, 729;
IT 1,313,914;
IT 1,317,169;
IT 1,316,131;
IT 1,326,531;
WO 08/129,019;
WO 2009/019,259;
WO 2009/053,485.
[0003] The track of cable transportation systems of the above type sometimes has at least
one junction. One particular type of junction is where the track splits into two at
a stop station for two vehicles travelling in opposite directions. Junctions may also
be needed for other purposes, such as for access to a depot or simply to change route.
[0004] Cable transportation system tracks may comprise two-way and one-way sections, where
the transportation units pass in opposite directions.
[0005] Cable transportation systems of the above type comprise at least two endless haul
cables which are clamped to the transportation units by clamps integral with the transportation
units.
[0006] One example of a switch for cable transportation systems of the above type is described
in Patent
IT 1,326,531, in which the switch comprises a track section defined by two curved parallel rails,
which extend along respective arcs, are fitted to a pivot, and are designed to connect
different branches of the track, depending on the angular position of the pivot.
[0007] Though effective, the switch described has the drawback of having a very large, extremely
heavy moving part. Moreover, changing route involves considerable travel of the moving
part and so takes a long time.
[0008] Other types of cable transportation system switches are described in Patent Applications
EP 2,407,366 and
EP 2,441,636, wherein at least one movable rail with one degree of freedom along an operating
plane is moved between two given positions by an actuating system comprising a linear
actuator.
[0009] The switch described in
EP 2,407,366 has the advantage of being extremely simple and of minimizing the mass to be moved,
but does not allow for changing direction with curved rails.
[0010] Conversely, the switch described in
EP 2,441,636 has four movable rails and allows for curved rails, but the mass to be moved is considerable
and projects laterally with respect to the track.
[0011] It is an object of the present invention to provide a cable transportation system
of the above type designed to minimize the drawbacks of the known art.
[0012] According to the present invention, there is provided a cable transportation system
for moving transportation units along a given track, the cable transportation system
comprising a plurality of fixed rails in a given plane; and a switch located between
the fixed rails and comprising a plurality of movable rails designed to assume respective
work positions, in which the movable rails lie along the given plane, and respective
rest positions, in which the movable rails are located beneath the given plane.
[0013] This way, the movable rails may be straight or curved, the switch does not project
laterally with respect to the track, and the mass to be moved is extremely small.
[0014] In a preferred embodiment of the present invention, the switch comprises a first
and second movable rail movable alternately.
[0015] In other words, using only two movable rails, a switch can be formed with curved
and/or straight rails.
[0016] In a preferred embodiment of the present invention, the first and second movable
rail, in their respective work positions, rest against respective fixed rails.
[0017] In other words, the movable rails are supported to prevent further movement out of
their respective work positions.
[0018] Preferably, the first and second movable rail perform respective rotation-translation
movements; the respective work positions being located slightly beyond the top dead
centre positions of the respective rotation-translation movements.
[0019] This configuration of the movable rails, combined with their resting against the
fixed rails, provides for establishing naturally stable work positions of the movable
rails, with no need for active locking mechanisms.
[0020] In another preferred embodiment of the present invention, the switch comprises an
actuating assembly comprising one actuator for moving the first and second movable
rail.
[0021] This makes the switch extremely economical.
[0022] More specifically, the actuating assembly comprises an articulated mechanism comprising
the first and second movable rail.
[0023] In other words, the first and second movable rail form part of the same articulated
mechanism, which moves both.
[0024] Preferably, the articulated mechanism comprises a first articulated parallelogram
comprising the first movable rail, two first cranks, and a fixed structure; and a
second articulated parallelogram comprising the second movable rail, two second cranks,
and the fixed structure.
[0025] The first and second articulated quadrilateral produce respective rotation-translation
movements of the first and second movable rail.
[0026] In a preferred embodiment of the present invention, one of the first cranks and one
of the second cranks are linked, preferably rotate about a common axis of rotation,
and are connected by a shaft coaxial with the common axis of rotation.
[0027] This way, it is relatively easy to operate the first and second movable rail by a
single, preferably rotary, actuator.
[0028] In a preferred embodiment of the present invention, the first cranks are offset angularly
with respect to the second cranks.
[0029] This makes it possible to move the cranks alternately.
[0030] In a preferred embodiment of the present invention, the switch comprises supports
for supporting the movable rails in their respective rest positions.
[0031] The rest position is also conveniently defined by supports located next to the movable
rails, in a given space beneath the given plane.
[0032] In a preferred embodiment of the present invention, the supports are designed to
cushion the last part of the movement of the movable rails, close to the respective
rest positions.
[0033] This provides for arresting the movable rails smoothly.
[0034] Because the movable rails form part of the same articulated mechanism with one degree
of freedom, cushioning one of the movable rails in the rest position also cushions
the other movable rail in the work position.
[0035] Preferably, the cable transportation system comprises at least one auxiliary drive
system located close to the switch, to make up for the absence of the cable, which
would interfere with the switch.
[0036] Preferably, the auxiliary drive system is located beneath the given plane, so as
not to take up space on either side of the track.
[0037] A non-limiting embodiment of the present invention will be described by way of example
with reference to the attached drawings, in which :
Figures 1 and 2 show views in perspective, with parts removed for clarity, of a cable
transportation system in accordance with the present invention in two different operating
configurations;
Figures 3 and 4 show smaller-scale plan views, with parts removed for clarity, of
the Figure 1 and 2 system;
Figures 5 and 6 show schematic views in perspective, with parts removed for clarity,
of the Figure 1 and 2 system.
[0038] Number 1 in Figure 1 indicates as a whole a cable transportation system for moving
transportation units (not shown) along a track 2 comprising a junction 3. Track 2
is defined by fixed outer rails 4 and 5; fixed inner rails 6 and 7; and a switch 8
between fixed outer rails 4 and 5.
[0039] Track 2 comprises three sections 9, 10, 11 defined by fixed rails 4, 5, 6, 7 converging
towards switch 8. Cable transportation system 1 comprises auxiliary drive systems
12, 13, 14 for moving the transportation units (not shown). In the example shown,
auxiliary drive systems 12, 13, 14 comprise powered wheels designed to contact the
transportation units (not shown). Auxiliary drive systems 12, 13, 14 are used in the
absence of the haul cable (not shown), which is absent at switch 8 to avoid interfering
with it. In the example shown, auxiliary drive systems 12, 13, 14 are located between
fixed rails 4, 5, 6, 7. More specifically, auxiliary drive systems 12 and 14 are associated
with fixed rail 4, and auxiliary drive system 13 is associated with fixed rail 7.
[0040] Track 2 extends along a plane P, and switch 8 is movable crosswise to plane P. Switch
8 as a whole is contained beneath plane P. Switch 8 comprises two movable rails 15
and 16. Movable rail 15 is designed to connect fixed rails 4 and 7, and is parallel
to fixed rail 5. Movable rail 16 is designed to connect fixed rails 5 and 6, and is
parallel to rail 4.
[0041] Switch 8 comprises an actuating assembly 17 connected to movable rails 15 and 16
and for raising one of movable rails 15, 16 and simultaneously lowering the other.
[0042] As shown more clearly in Figures 5 and 6, actuating assembly 17 preferably comprises
a single rotary actuator 18, and an articulated mechanism 19 operated by actuator
18.
[0043] Articulated mechanism 19 comprises an articulated quadrilateral 20 comprising movable
rail 15, two cranks 21, 22, and a fixed structure 23; and an articulated quadrilateral
24 comprising movable rail 16, two cranks 25, 26, and fixed structure 23.
[0044] In other words, cranks 21 and 22 are hinged at one end to fixed structure 23, and
at the opposite end to movable rail 15.
[0045] Likewise, cranks 25 and 26 are hinged at one end to fixed structure 23, and at the
opposite end to movable rail 16.
[0046] Articulated quadrilaterals 20 and 24 are both operated by actuator 18.
[0047] Preferably, cranks 22 and 26 are hinged to fixed structure 23 about a common axis
A1. Cranks 22 and 26 are connected by a shaft 27 (Figure 5) which extends along and
rotates about axis A1, and is connected to actuator 18. Cranks 22 and 26 are offset
angularly about shaft 27.
[0048] Cranks 21 and 25 are hinged to fixed structure 23 about a common axis A2. Cranks
21 and 25 are connected by a shaft 28 which extends along and rotates about axis A2.
[0049] Cranks 21 and 25 are offset angularly about shaft 28.
[0050] Actuating assembly 17 provides for moving movable rails 15 and 16 along respective
planes substantially perpendicular to plane P.
[0051] Cranks 21 and 22 are designed so that the work position of movable rail 15 corresponds
to cranks 21 and 22 in close to their respective top dead centre positions. More specifically,
the work position of movable rail 15 corresponds to cranks 21 and 22 positioned just
slightly past their respective top dead centre positions.
[0052] This configuration provides for establishing a stable position of articulated quadrilateral
20.
[0053] More specifically, movable rail 15 performs a rotation-translation movement between
a raised work position and a lowered rest position.
[0054] Likewise, the work position of movable rail 16 corresponds to cranks 25 and 26 positioned
just slightly past their respective top dead centre positions. This configuration
provides for establishing a stable position of articulated quadrilateral 24.
[0055] Movable rail 16 performs a rotation-translation movement between a raised work position
and a lowered rest position. Angularly offsetting cranks 21, 22 on one side with respect
to cranks 25, 26 on the other side, and inverting the rotation direction, provide
for alternate operating configurations of switch 8.
[0056] With reference to Figure 3, movable rail 15 is positioned resting against a fixed
stop 29 located at the apex formed by fixed rails 6 and 7. Fixed stop 29 arrests rotation-translation
of movable rail 15, and prevents it from moving any further in a direction D1.
[0057] Likewise, as shown in Figure 4, movable rail 16 is positioned resting against a fixed
stop 30 located along fixed rail 5 to arrest rotation-translation of movable rail
16 and prevent it from moving any further in a direction D2.
[0058] Movable rails 15 and 16 are locked close to the top dead centre positions of their
respective rotation-translation movements. More specifically, rails 15 and 16 are
locked just past their respective top dead centre positions.
[0059] With reference to Figures 1 and 2, movable rails 15 and 16 rest on fixed supports
31.
[0060] Each support 31 comprises a base 32 housing a shock-absorbing member 33 designed
to contact one of movable rails 15, 16.
[0061] In the embodiment described and illustrated, and with reference to Figures 3 and
4, movable rail 16 is curved and integral with a frame 34 which, as shown more clearly
in Figures 5 and 6, is supported by two cranks 26.
[0062] In actual use, shaft 27 is rotated in opposite directions about axis A1 to alternatively
set movable rails 15, 16 to their respective work positions.
[0063] In Figure 1, movable rail 15 is set to the work position, and movable rail 16 to
the rest position resting on two supports 31. Anticlockwise rotation of cranks 26
and 22 about axis A1 lowers movable rail 15 and raises movable rail 16 into the work
position shown in Figure 2. As movable rail 16 nears the work position, movable rail
15 comes to rest on supports 31, which slow down the final stage in the movement of
articulated mechanism 19 as a whole until movable rail 16 is positioned resting against
stop 30.
[0064] Obviously, rotating cranks 22 and 26 in the opposite direction restores movable rail
15 to the work position and movable rail 16 to the rest position in the same way.
[0065] Clearly, changes may be made to the cable transportation system described herein
without, however, departing from the scope of the accompanying Claims.
1. A cable transportation system for moving transportation units along a given track,
the cable transportation system (1) comprising a plurality of fixed rails (4, 5, 6,
7) in a given plane (P); and a switch (8) located between the fixed rails (4, 5, 6,
7) and comprising a plurality of movable rails (15, 16) designed to assume respective
work positions, in which the movable rails (15, 16) lie along the given plane (P),
and respective rest positions, in which the movable rails (15, 16) are located beneath
the given plane (P).
2. A system as claimed in Claim 1, wherein the switch (8) comprises a first and second
movable rail (15, 16) movable alternately.
3. A system as claimed in Claim 1 or 2, wherein the first and second movable rail (15,
16), in their respective work positions, rest against respective fixed rails (7, 5).
4. A system as claimed in Claim 3, wherein the first and second movable rail (15, 16)
perform respective rotation-translation movements; the respective work positions being
located slightly beyond the top dead centre positions of the respective rotation-translation
movements.
5. A system as claimed in any one of the foregoing Claims, wherein the switch (8) comprises
an actuating assembly (17) comprising one actuator (18) for moving the first and second
movable rail (15, 16).
6. A system as claimed in Claim 5, wherein the actuating assembly (17) comprises an articulated
mechanism (19) comprising the first and second movable rail (15; 16) and having one
degree of freedom.
7. A system as claimed in Claim 6, wherein the articulated mechanism (19) comprises a
first articulated parallelogram (20) comprising the first movable rail (15), two first
cranks (21, 22), and a fixed structure (23); and a second articulated parallelogram
(24) comprising the second movable rail (16), two second cranks (25, 26), and the
fixed structure (23).
8. A system as claimed in Claim 7, wherein one of the first cranks (21, 22) and one of
the second cranks (25, 26) are linked, preferably rotate about a common axis of rotation
(A1; A2), and are connected by a shaft (27; 28) coaxial with the common axis of rotation
(A1; A2).
9. A system as claimed in Claim 8, wherein the first cranks (21, 22) are offset angularly
with respect to the second cranks (25, 26).
10. A system as claimed in any one of the foregoing Claims, wherein the switch (8) comprises
supports (31) for supporting the movable rails (15, 16) in their respective rest positions.
11. A system as claimed in any one of the foregoing Claims, wherein the supports (31)
are designed to cushion the last part of the movement of the movable rails (15, 16),
close to the respective rest positions.
12. A system as claimed in any one of the foregoing Claims, and comprising at least one
auxiliary drive system (12, 13, 14) located close to the switch (8).
13. A system as claimed in Claim 12, wherein the auxiliary drive system (12, 13, 14) is
located beneath the given plane (P).