TECHNICAL FIELD
[0001] The invention concerns in general the technical field of crane solutions. Especially
the invention concerns safety solution for crane tracks.
BACKGROUND OF THE INVENTION
[0002] Traditionally crane tracks are manufactured of track elements coupled together in
some known manner. The track elements, also known as track profiles, are traditionally
manufactured of iron, which has provided hard enough structure in order to meet the
challenges in lifting heavy objects. However, the problem with the iron made track
elements is that they are heavy to manufacture, but also to build up. Moreover, as
the crane bridge is many times moved manually in the crane track from a first location
to another the operation requires lot of power and energy.
[0003] The above mentioned challenges, among other reasons, established a need for light
crane track structures especially in application areas wherein there is not necessary
need for heavy crane solutions. In the light crane solutions the crane track is typically
manufactured from steel or aluminum.
[0004] Fig. 1 illustrates an example of a crane solution in which the crane structure, i.e.
the girder 101, is to be fastened in a ceiling with fasteners 103. A hoist 105 is
coupled in the girder 101 with a trolley 107. The trolley 107 is arranged to travel
along a runway arranged inside the girder 101 by means of shaping the inner part of
the girder 101 accordingly. The crane solution in Fig. 1 is an example and there are
multiple types of crane solutions available for need. The most common system has two
parallel runways 101, trolleys 107 inside them and girder 101 fixed to those trolleys.
The trolley 107 is arranged to travel along this girder (so called bridge crane).
[0005] Fig. 2 discloses a cross-sectional illustration on a crane track solution according
to a prior art solution. The figure discloses the girder 101, the fastener 103 and
the trolley 107. The trolley 107 comprises a body part 201 into which tyres 203 are
fastened with a shaft. The sizes of the tyres 203, as well as material of the tyres,
are advantageously adjusted to the size of the runway so that the rolling resistance
is minimized. The hoist 105 is configured to be fastened in the trolley 107 with the
shaft 205. Fig. 2 discloses how the runway for moving the trolley 107 along the girder
101 is achieved by shaping the girder 101. The control for moving the trolley 107
along the girder 101 and the control for using the hoist 105 may be arranged manually
or by means of a controller, which provides control signals for motors within the
trolley and the hoist. The delivery of control signals to the respective motors can
be arranged either in wired or wireless manner by using known communication technologies.
[0006] One problem with the known solutions, especially when the crane track is manufactured
from aluminum, is that the weight-carrying capacity, or at least the durability of
such tracks, may be limited. In operation the course of the trolley along the girder
101 repeats itself i.e. many times the lifting and downlifting of a load happens in
the same locations. Thus, the stress towards the crane track is emphasized in some
locations of the track. Another fact is that the stress is shock-type in nature, especially
when lifting a load, but also a continuous vibration exists towards the structure
during the lifting and downlifting. The stress causes weakening of the track in the
course of time and track may break down. In the worst case the trolley together with
hoist and load may fall down, which causes damages in the crane solution and causes
costs in a form of repairing costs but also in the form of downtime of the system.
Moreover, the fall down of the mentioned parts may cause personal injuries to personnel
operating the system.
[0007] Thus, there is continuous need for improving the safety in crane solutions.
SUMMARY OF THE INVENTION
[0008] An objective of the invention is to present a crane track structure and a crane for
improving safety. Another objective of the invention is that the crane track structure
and the crane improve safety by increasing an endurance of the crane track structure
with the present invention.
[0009] The objects of the invention are reached by a crane track structure and a crane as
defined by the respective independent claims.
[0010] According to a first aspect, a crane track structure comprising a girder is provided,
wherein a portion of the girder forms a runway providing at least one surface for
at least one tyre of a trolley configured to travel at least partly within the girder,
the said portion of the girder further comprising at least one cavity running at least
partly along the length of the girder wherein the crane track structure further comprising
at least one supporting means arranged in the at least one cavity.
[0011] The supporting means may be configured to be fastened within the cavity in at least
one of the following manner: chemically, mechanically. The mechanical fastening may
be arranged by modifying a surface of at least one of the following: an inner wall
of the cavity of the girder, supporting means. The mechanical fastening may also be
arranged with at least one of the following: wedge-shaped structure of the supporting
means, wedge or sleeve in at least one end of the supporting means.
[0012] The structure may further comprise at least one end plate mountable with the girder,
wherein the at least one end plate comprises at least one through hole for conveying
the supporting means through the end plate in order to fastening the supporting means
with the end plate. The fastening of supporting means may be arranged with a fastening
element against the end plate. The fastening of supporting means may also be arranged
by bending at least part of the supporting means extending through the at least one
through hole of the end plate against the end plate.
[0013] The supporting means within the structure may be at least one of the following: a
flat bar, a tube, a cable, a wire or a wire rope.
[0014] According to a second aspect, a crane is provided wherein the crane comprises a crane
track structure as described above.
[0015] The exemplary embodiments of the invention presented in this patent application are
not to be interpreted to pose limitations to the applicability of the appended claims.
The verb "to comprise" is used in this patent application as an open limitation that
does not exclude the existence of also un-recited features. The features recited in
depending claims are mutually freely combinable unless otherwise explicitly stated.
[0016] The novel features which are considered as characteristic of the invention are set
forth in particular in the appended claims. The invention itself, however, both as
to its construction and its method of operation, together with additional objects
and advantages thereof, will be best understood from the following description of
specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0017]
- Fig. 1
- illustrates a crane solution according to a prior art,
- fig. 2
- illustrates a cross-sectional illustration on a crane track solution according to
a prior art,
- fig. 3
- illustrates a structure according to an example of the present invention,
- fig. 4
- illustrates another example of a structure according to an example of the present
invention, and
- figs. 5 a-b
- illustrate examples of an implementation of the invention according to the present
invention.
DETAILED DESCRIPTION
[0018] The present invention relates to a utilization of a shape of a crane track profile
for establishing a novel safety structure. Fig. 3 illustrates an example of a track
profile in which the solution according to an example of the present invention is
implemented. In the following detailed description it is used a term girder 101 in
order to refer to track profile for emphasizing that the referred part in the crane
solutions is the one in which the trolley 107 travels. The trolley 107 comprises the
body part 201 and the tyres 203 coupled with the shaft to the body part 201. According
to the invention the profile of the girder 101 is such that it comprises at least
one cavity 301 traveling at least part of a length of the girder 101 and the location
of the cavity 301 within the girder 101 is at least partly below the runway of the
trolley 107. For the sake of clarity the runway of the trolley 107 refers to opening
within the girder 101, which provides necessary surface or surfaces 303 on which the
tyres 203 of the trolley 107 may roll when the trolley 107 is moved along the runway.
[0019] According to an example of the invention at least part of the at least one cavity
301 is configured to be equipped with a supporting means 305, which increases support
to the structure and thus mitigating the risk that the girder 101 breaks down in the
course of time. Additionally, as the supporting means 305 may advantageously be selected
so that it is manufactured from a material having stronger durability than the girder
101 itself, the idea of equipping the girder 101 with the supporting means improves
the safety even if the girder 101 breaks down. Namely, the supporting means 305 may
increase the durability of the girder 101 to maintain its shape as well as to provide
support for the trolley 107 if some break down of the girder 101 happens.
[0020] Some examples of the supporting means 305 are a flat bar, a tube, a cable, a wire
or a wire rope. The flat bar or the tube may have a hollow or a solid structure. The
supporting means 305 may be implemented by having one or more mentioned elements in
any combination arranged in the at least one cavity 301 of the girder 101. The material
of the supporting means may be, but is not limited to, iron, any alloy comprising
iron, composite material, carbon fiber or nylon.
[0021] According to an example of the invention the size of the supporting means 305 is
such that it may be push in the cavity by providing additional force to the supporting
means 305. In other words, the supporting means 305 and the inner wall of the cavity
301 comprise such a mutual friction that the supporting means 305 locks removably
within the cavity 301. Such an arrangement provides the necessary support also in
case of breakdown of the girder 101 at some location. According to another example
of the invention the supporting means 305 may be locked in the cavity 301 with some
compound applicable for fastening two parts together. For example, the locking may
be arranged by providing applicable glue between the inner wall of the cavity 301
and the supporting means 305, when the supporting means 305 are installed in the cavity
301 and thus fastening the supporting means 305 in the cavity 305. According to some
further example of the invention the supporting means 305 may be equipped with some
mechanical fastening means. The mechanical fastening means may e.g. be a hook arranged
in at least one end of the supporting means 305, which may be hooked over the girder
101 at the respective end. It is also possible to arrange a specific anchor structure
for the hook on the girder 101. Any similar mechanical fastening means to the hook
may be used, such as an applicable wedge or sleeve incorporated at the end or ends
of the supporting means 305. Furthermore, it is possible to modify the surface of
the supporting means 305 so that it provides a mechanical locking when pushed in the
cavity 301. For example, the surface may be modified by roughening it with a file
tool or similar in order to increase the friction between the elements. Also, a lamella
structure may be arranged on the surface of the supporting means 305 for gaining the
frictional effect and thus locking the elements together as tightly as needed. It
is also possible to modify the inner surface of the cavity 301 in order to increase
the friction between the elements. In addition to the mentioned ways of implementing
the necessary locking the supporting means 305 may be shaped in such a manner that
it locks within the cavity 301. An example of the applicable cross-sectional shape
of the supporting means may be a triangle with optimal dimensions for the cavity i.e.
the apexes of the triangle touch the inner surface of the cavity along the length
of the supporting means 301. Furthermore, the supporting means 305 may be wedge-shaped
so that it is possible to convey in the cavity from one end of the girder 101 and
by locking the other end with some locking means, the supporting means 305 is adjusted
in place. Also in some implementations the cavity may be shaped in a manner that it
provides locking arrangement into at least one direction with the supporting means
305. The cavity may e.g. be wedge-shaped into which an applicable supporting means
305 are inserted.
[0022] In typical implementations of crane tracks end plates are arranged to the girder
101. The purpose of the end plates is to limit the movement of the trolley 107, but
also to protect the runway against dirt. Further, the end plates also limit the movement
of cable trolleys as well as increase a strength of the structure in general and provides
also fastening possibility of the track e.g. on the ceiling. Fig. 4 illustrates a
crane track solution with a girder 101 equipped with the supporting means 305 according
to the present invention in which end plates 401 are arranged to at least limit the
runway of the trolley 107. The end plates 401 may be fastened with the girder 101
with known means, such as bolts, screws or similar.
[0023] In some crane track solutions so called joint element, such as a track joint, is
used in coupling two track profiles together. The joint elements may be used in the
similar manner as the end plates in providing tools for fastening the supporting means
in the structure. Thus, in this context the term end plate shall be considered to
cover any joint element used in crane tracks.
[0024] Fig. 5a illustrates a more detailed example of the present invention as a side view,
when an end plate 401 is utilized in fastening the supporting means 305 within the
structure. In the present example the supporting means 305 is such that it is flexible
to adjust in the structure. The supporting means 305 may be a wire rope in the present
example. An applicable through hole is arranged in the end plate 401 in order to convey
the supporting means through the end plate 401. When the end plate 401 is fastened
with the girder 101 it is possible to lock the supporting means 305 in the structure
with an applicable fastening element 501. The fastening element 501 is advantageously
such that it comprises a locking mechanism for the supporting means 305. For example,
the fastening element 501 may comprise necessary number of through holes or grooves
into which the supporting means 305 are to be adjusted and the locking may be arranged
with screws 503, for example, as illustrated in Fig. 5b. The type of the fastening
element 501 may differ from the one illustrated in Fig. 5a and Fig. 5b. In some example
of the invention the fastening element 501 may be one or more bolts for which counter-holes
are arranged in the end plate 401. Thus, the supporting means 305 may be fastened
to the end plate 401 by tightening the one or more bolts when the supporting means
501 is arranged between the bolts and the end plate 401. The utilization of end plates
401 for fastening the supporting means 305 in the structure has also the advantage
in providing a further stabilizing effect into the structure as a whole. This is because
the supporting means 305 combines the end plates and thus stabilizes the whole structure.
[0025] According to some further example of the invention the supporting means 305, when
it is manufactured from rigid material, may be conveyed through the end plates 401
via an applicable through holes and fastened by bending the supporting means 305 along
the surface of the end plate 401. The bending may be implemented with any known manner
by providing the necessary power for the supporting means 305.
[0026] When describing the present invention multiple inventive solutions are provided in
order to fasten supporting means 305 to a crane track structure. Even if the inventive
solutions are mainly described separately in the description above, it is possible
to combine the separate solutions in any manner within the inventive idea defined
in the independent patent claims. As a non-limiting example it is possible to utilize
glue in fastening the supporting means 305 with the girder 101, but in addition to
that it is possible to use the end plates for additionally fastening the supporting
means 305 within the structure.
[0027] In some implementations of the present invention the supporting means 305 may be
arranged only in some parts of the girder 101. Advantageously, they can be arranged
to those locations into which the stress is directed to due to operational reasons.
[0028] Above it is disclosed a structure for improving safety in crane solutions. As said,
the described structure advantageously prevents, or at least slows down, the drop
down of the trolley if the runway of the trolley at least partly breaks down.
[0029] Some advantageous embodiments according to the invention were described above. The
invention is not limited to the embodiments described. The inventive idea can be applied
in numerous ways within the scope defined by the claims attached hereto.
1. A crane track structure comprising a girder (101), wherein a portion of the girder
(101) forms a runway providing at least one surface for at least one tyre of a trolley
(107) configured to travel at least partly within the girder (101), the said portion
of the girder (101) further comprising at least one cavity (301), the cavity (301)
running at least partly along the length of the girder (101), characterized in that the crane track structure further comprising at least one supporting means (305)
arranged in the at least one cavity (301).
2. The crane track structure according to claim 1, wherein the supporting means (305)
is configured to be fastened within the cavity (301) in at least one of the following
manner: chemically, mechanically.
3. The crane track structure according to claim 2, wherein the mechanical fastening is
arranged by modifying a surface of at least one of the following: an inner wall of
the cavity (301) of the girder (101), supporting means (305).
4. The crane track structure according to claim 2, wherein the mechanical fastening is
arranged with at least one of the following: wedge-shaped structure of the supporting
means (305), wedge or sleeve in at least one end of the supporting means (305).
5. The crane track structure according to claim 1, wherein the structure further comprising
at least one end plate (401) mountable with the girder (101), wherein the at least
one end plate (401) comprises at least one through hole for conveying the supporting
means (305) through the end plate (401) in order to fastening the supporting means
(305) with the end plate (401).
6. The crane track structure according to claim 5, wherein the fastening of supporting
means (305) is arranged with a fastening element (501) against the end plate (401).
7. The crane track structure according to claim 5, wherein fastening of supporting means
(305) is arranged by bending at least part of the supporting means (305) extending
through the at least one through hole of the end plate (401) against the end plate
(401).
8. The crane track structure according to any of the preceding claims, wherein the supporting
means (305) is at least one of the following: a flat bar, a tube, a cable, a wire
or a wire rope.
9. A crane, characterized in that the crane comprises a crane track structure of any of the preceding claims.