Note: Descriptions are shown in the official language in which they were submitted.
CA 03135312 2021-09-28
WO 2020/201418
PCT/EP2020/059389
LOCKING DEVICE FOR COUPLING A WEAR ELEMENT TO A SUPPORT IN AN EARTH
MOVING MACHINE
DESCRI PTION
Field of the Invention
The invention relates to a locking device for coupling a wear element to a
support in an earth
moving machine, the support comprising a housing and the wear element
comprising a hole
such that, in an assembled position, the housing and the hole are at least
partially aligned
(that is, partially overlapping), where the locking device is suitable for
being introduced inside
the housing.
In the present description and claims it has to be understood that, when it is
said that "the
housing and the hole are at least partially aligned (that is, partially
overlapping)", what is
meant is the following:
- the hole defines a hole longitudinal axis
- the housing defines a housing longitudinal axis
- in an assembled position, both longitudinal axes are parallel to each other
and close to each
other or coincident in space
- a cross section of said hole projected according to the hole longitudinal
axis overlaps, or,
at least partially overlaps, the cross section of said housing
- the hole and the housing are mutually exclusive in the sense that neither
the hole includes
part of the housing or the whole housing nor the housing includes part of the
hole or the
whole hole
- the hole and the housing are aligned in the sense that, in a direction
according to both
longitudinal axes, one of them starts when the other finishes (in the case
when there is a
complete overlapping). In the case when there is only a partial overlapping,
those parts of
the hole and the housing that correspond to the overlapping area are aligned.
It must be taken into account that a locking device is designed for a specific
support and
wear element pair. The designer must therefore know all the details of both
the support and
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 2 -
PCT/EP2020/059389
wear element affecting the locking device. The designer must particularly know
the relevant
dimensions of both the support and wear element for the design of the locking
device.
Additionally, it must be taken into account that the wear system is designed
to sustain given
wear. In this sense, the expected wear of the wear system and how it will
affect the locking
device and the dimensions of the wear element and of the support affecting the
locking
device are also known. All these data are "starting information" when a
specific locking device
has to be designed. Therefore, it must be considered that all this information
"is part of the
locking device itself" since they are pre-established values for the design
thereof. So,
although the claims may define an entity (e.g., the locking device as such),
it is admissible
that they refer to the wear element, the support or parts thereof when
defining the locking
device, as, in fact, the relevant data of the wear element and the support are
implicitly part
of the locking device as such.
State of the Art
Earth moving machines are used in excavation, demolition, construction,
mining, and
dredging works and similar activities. They generally have a shovel or bucket
where the
material is collected. The shovel or bucket is subjected to high stresses and
erosion,
particularly in the area of the lip (also referred to as blade). As a result,
the shovel or bucket
usually has a plurality of wear elements protecting it against wear and
impacts and/or
improving penetration in the ground, such as teeth, supports or tooth bars
(also referred to
as adapters), and/or (front and side) guards, for example.
All these wear or protective elements and, particularly the teeth, are
subjected to high
mechanical stress, plastic deformations, and intense wear. For this reason,
they usually have
to be replaced with a certain frequency when the fracture thereof or the wear
sustained so
requires. Furthermore, these machines can work in a wide range of
applications, in which it
may be necessary to change the design of the teeth to improve performance of
the bucket.
The wear elements can be attached to other wear elements (such as a tooth
attached to an
adapter) and/or can be attached to the lip or blade of the bucket or shovel
(such as an adapter
attached to a lip).
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 3 -
PCT/EP2020/059389
The wear or protective elements can be fixed mechanically (easier and faster
to change) or
welded (less expensive but hard to change and with the risk of damaging the
blade with the
weld), depending on the degree of abrasiveness of the ground and on the
dimensions of the
machine. It must also be taken into account that large earth moving machines,
particularly
those operating in quarries and mines, are essential for production in said
sites. To that end,
the inactivity times of these machines may significantly affect productivity
thereof, and it is of
great interest that the wear elements can be changed quickly, safely, and on
site, without
having to take the machine or the bucket to a shop to use special equipment.
To that end, it
is usually advantageous for the wear elements to be fixed mechanically and to
use, to that
end, a locking device, for example a pin.
Usually the wear element has a cavity in which a nose arranged in the support
(for example,
the adapter) on which the wear element will be assembled is housed. A through
hole goes
through the nose, defining a housing, and at least one of the walls of the
cavity has a hole
such that, in an assembled position, the hole or holes in the walls of the
cavity are
superimposed on (i.e., aligned or overlapping with) the housing and the
locking device (which
is substantially an elongated pin) can be introduced through the hole in the
wall of the cavity
until it is housed in the housing. In the assembled position, the locking
device partially
projects from the housing and (at least partially) occupies the hole in the
wall of the cavity.
The wear element is thereby locked in the assembled position. This
superimposing (or
alignment or overlapping) does not have to be complete, where partial
superimposing is
sufficient provided that it is sufficient for the insertion of the pin. This
is also valid in the
present invention. In certain cases, it is the wear element that has a nose
and the support
that has a cavity in which, in the assembled position, the nose is housed, but
otherwise, the
rest of the concept works in a similar fashion.
The locking elements indicated above, such as the one described in document EP
1 741 842
Al, for example, are known.
However, in certain cases it has been observed that locking devices of the
state of the art
present some drawbacks. Thus, for example, it would be desirable to have
locking devices
which can be housed completely inside the housing before positioning the wear
element on
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 4 -
PCT/EP2020/059389
the nose of the support, since this facilitates the assembly and disassembly
of the locking
device, particularly in those cases in which the wear elements are very close
to one another.
In other cases, the locking device (or the tip of the locking device which is
in contact with the
wear element) not being subjected to a force that pushes it against the wear
element, i.e.,
the locking device working independently of the wear element, is sought.
Moreover, there is
always a need to make locking devices in the most cost-effective and simplest
manner
possible.
Description of the Invention
The object of the invention is to overcome these drawbacks. This is achieved
by means of a
locking device of the type indicated above, characterized in that the locking
device
comprises:
- a locking element with a locking end and an internal end opposite the
locking end,
- an internal element,
- movement means suitable for moving the locking element with respect to the
internal
element, in a reversible manner, between a retracted (or withdrawn) position
and an
extended (or deployed) position, where the movement between retracted position
and the
extended position defines a direction of movement, and
- elastic means which, in the extended position, exert a force in the
direction of the direction
of movement that tends to move the locking element closer to the internal
element.
Preferably in the retracted position the locking element is completely within
said housing and
completely outside of said hole.
In the present invention, the wear element has a cavity in which a nose
arranged in the
support (for example, the adapter) on which the wear element will be assembled
is housed.
A hole in the nose defines a housing and one of the walls of the cavity (the
one facing the
open end of the housing) has another hole such that, in an assembled position,
the hole in
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 5 -
PCT/EP2020/059389
the wall of the cavity is superimposed on (i.e., aligned or overlapping with)
the housing and
the locking device (which is substantially an elongated pin) can be introduced
through the
hole in the wall of the cavity until it is housed in the housing.
Alternatively, the hole in the
nose may be a through hole (so that the housing has two open ends), in which
case there
may be two holes in both walls of the cavity facing the open ends of the
housing.
In general, in the retracted position the locking element must be completely
within the
housing so that the wear element can be put over the nose of the support
without being
impeded by the locking element. In the retracted position the locking element
is completely
outside the hole,
In the extended position part of the locking element (the corresponding
locking end or at least
part of the corresponding locking end) is outside the housing and is in the
hole, so that it is
able to be in contact with the wear element (in fact, it will be in contact as
this contact will
precisely be the responsible of fixing the wear element to the support. The
part of the locking
element that goes into the hole is simultaneously going out of the housing, as
the housing
and the hole are mutually exclusive (I.e., none of them includes, comprises or
surrounds the
other).
Preferably in the extended position the locking end is blocking the wear
element, while in the
retracted position the locking element is out of the blockage of the wear
element. In fact, the
housing has a main axis that is parallel to the direction of movement, and the
hole is after
the open end of the housing. In order to put the wear element in the assembled
position with
the support, the wear element has to be moved in an assembling direction. This
assembling
direction forms an angle greater than 60 with the direction of movement
(preferably greater
than 75 and more preferably greater than 85 ). So, when the locking device is
in the ex-
tended position, part of it (the locking end or, at least, part of the locking
end) is in the hole
and, therefore acts as a blockage against a possible movement of the wear
element in the
assembling direction. On the contrary, when the locking element is in the
retracted position,
the locking device is completely out of the hole, i.e., it is out of the
blockage of the wear
element. So, the wear element can move freely in the assembling direction.
One of the additional advantages of the present invention is that its
configuration facilitates
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 6 -
PCT/EP2020/059389
disassembly, since the force of the elastic means facilitates the retraction
(or withdrawing) of
the locking device.
Another advantage of the present invention is in that the locking device is
inside the housing
of the support, since the user thereby does not have to take the locking
device out when
changing the wear element, but rather can extract the wear element and put a
new on in
place without handling the locking device. That is particularly interesting
since it is often not
necessary to change the locking device (which can continue to be operative)
when the wear
element is changed, which allows achieving cost savings.
Preferably, the locking device comprises a capsule housing therein the
internal element and
at least the internal end of the locking element. It is particularly
advantageous that, in the
retracted position, the locking element is also housed in its entirety inside
the capsule. It is
likewise advantageous for the capsule to have a cross-section which, in at
least one area, is
larger than the hole of the wear element. The capsule coming out of the
housing of the
support and not being able to pass through the hole is thereby prevented in
the assembled
position.
Advantageously, the elastic means are a spring, although other elastic means
are possible.
Preferably, the movement means comprise rotation means. The rotation means
transform a
rotation into a longitudinal movement.
Advantageously, the locking element is a cylindrical body with a base facing
the internal
element and the internal element is also a cylindrical body with a base facing
the locking
element. This geometry of both elements allows a particularly advantageous
embodiment of
the rotation means in which the base of the internal element facing the
locking element
comprises a first inclined surface and the base of the locking element facing
the internal
element comprises a second inclined surface, where in the retracted position,
both inclined
surfaces are superimposed on one another, and during a movement between the
retracted
position and the extended position the second inclined surface slides over the
first inclined
surface, causing the movement of the locking element with respect to the
internal element.
In other words, as a result of the inclined surfaces a rotational movement can
be transformed
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 7 -
PCT/EP2020/059389
into a linear movement according to the direction of movement. In this
embodiment, the force
exerted by the elastic means tends to bring the first inclined surface and the
second inclined
surface together.
In the previous case, a preferred embodiment is one where the base of the
internal element
facing the locking element comprises a first seating surface arranged at the
end of the first
inclined surface which, in the extended position, is closer to the locking
element, and the
base of the locking element facing the internal element comprises a second
seating surface
arranged at the end of the second inclined surface which, in the extended
position, is closer
to the internal element, where in the extended position, both seating surfaces
are
superimposed on one another. The extended position is thereby rendered a
stable position
and the locking device does not tend to retract to retracted position due to
the force exerted
by the elastic means. It is particularly advantageous for one of the seating
surfaces to
comprise a first elevation at the end of the seating surface opposite the
attachment area
between the seating surface and its corresponding inclined surface. This first
elevation
thereby defines an "end of stroke" and prevents the rotation from continuing
beyond what is
expected. Another particularly advantageous solution is when one of the
seating surfaces
comprises a second elevation at the end of the seating surface close to the
attachment area
between the seating surface and its corresponding inclined surface. This
second elevation
prevents, for example due to the vibrations and impacts to which the wear
element is
subjected, the locking element and the internal element from rotating with
respect to one
another until the seating surfaces are no longer in contact with one another,
with the
subsequent risk that the locking device is retracted due to the force
generated by the elastic
means. The second elevation must be sized such that it prevents this
involuntary rotation but
allows the voluntary rotation performed at will to retract the locking device.
Likewise in the previous case, another preferred embodiment is when the base
of the internal
element facing the locking element comprises a first guide surface opposite
the first inclined
surface and the base of the locking element facing the internal element
comprises a second
guide surface opposite the second inclined surface, where, in the retracted
position, the first
guide surface and the second guide surface are superimposed on one another,
and during
a movement between retracted position and the extended position, the second
guide surface
slides along the first guide surface. In this case, when indicating that each
guide surface is
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 8 -
PCT/EP2020/059389
opposite its corresponding inclined surface, this means is that both surfaces
have a spatial
orientation in the same direction but in opposite senses. As will be seen
below in the
examples shown in the drawings, in some cases the inclined surface and its
corresponding
guide surface will be facing one another, whereas in other cases they will be
on opposite
sides of a projection, i.e., "their backs" will be facing one another. With
this orientation of the
two guide surfaces (opposite the corresponding inclined surfaces), the force
exerted by the
elastic means tends to separate one guide surface from the other. This
embodiment allows
facilitating the retraction of the locking device, since the guide surfaces
guide the locking
element when it transitions from the extended position to retracted position.
This embodiment
is compatible with the additional improvements indicated in the preceding
paragraph.
Additionally, in the event that the embodiment includes a second elevation
like the one
indicated above, then another additional improvement is when the second
elevation has a
maximum elevation point having a maximum height, in the sense of the direction
of
movement, with respect to the seating surface, and the guide surface
corresponding to the
inclined surface corresponding to the seating surface extends, in the
direction of movement,
beyond the maximum elevation point. The guide surface thereby performs its
guiding function
from the first instant of the retraction movement, which is when the second
elevation is
overcome.
Preferably, transitioning from retracted position to the extended position is
achieved by
means of a rotation of the locking element with respect to the internal
element of 360 or
less, preferably 180 or less, and very preferably 90 .
Advantageously, the rotation means comprise a hole arranged at the base of the
locking
element opposite the internal element, where the hole is coaxial with the
direction of
movement and does not present cylindrical symmetry according to the direction
of
movement.
Preferably, the locking device comprises anti-rotation means suitable for
preventing rotation
thereof with respect to the support. These anti-rotation means are
advantageously arranged
in the capsule.
Preferably, the locking device comprises air discharge means communicating the
space
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 9 -
PCT/EP2020/059389
comprised between the locking element and the internal element with the
outside. In fact, in
some cases the air remaining in this space is compressed when the locking
device is
retracted and generates an overpressure which hinders (and even prevents)
retraction. The
air discharge means allow the air trapped in this space to be discharged,
preventing the
generation of overpressure in this space.
Advantageously, the locking device comprises an 0-ring at an intermediate
point of the side
surface of the locking element. The purpose of this 0-ring is to prevent,
during operation of
the earth moving machine, dirt and/or fines (fines are understood in the
present description
as small-sized particles) from getting into the wear device. However, this 0-
ring may
exacerbate the risk of the overpressure indicated above being generated. It is
therefore
particularly advantageous for the air discharge means to comprise an air
discharge conduit
extending between the space comprised between the locking element and the
internal
element and an upper end, where the upper end of the air discharge conduit is,
according to
the direction of movement, below the 0-ring when the locking element and the
internal
element are in the extended position, and is, according to the direction of
movement, above
the 0-ring when the locking element and the internal element are in the
retracted position.
Therefore, when the locking device is extended, the upper end of the discharge
conduit is
"behind" the 0-ring and the entry of dirt and/or fines into the locking
element is prevented,
but, upon initiating retraction of the locking element, the upper end of the
discharge conduit
is located above the 0-ring, such that the air can exit the space comprised
between the
locking element and the internal element and the generation of an overpressure
hindering or
preventing retraction of the locking device is prevented.
Preferably, the air discharge conduit is a cavity arranged between the outer
side surface of
the locking element and the side surface of said capsule.
A preferred embodiment of a locking device according to the invention is when
the device
comprises a rod with a first end fixed to the internal element and a second
end housed inside
a cavity arranged in the locking element, where the second end is suitable for
being moved
according to the direction of movement along the cavity, where the cavity has
an opening
oriented towards the internal element and with the rod going through same, and
where the
elastic means are arranged between the second end of the rod and the opening.
In this case,
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 10 -
PCT/EP2020/059389
it is particularly advantageous for the first end of the rod to be fixed (and
preferably screwed)
to the internal element. It is also particularly advantageous for the locking
element to have a
mounting hole coaxial with the direction of movement and with a diameter
greater than the
maximum diameter of the rod such that the rod is suitable for being housed in
the cavity
through the mounting hole. In fact, the rod preferably has a head at its end
acting as a stop
for the elastic means, where this head is what defines the maximum diameter of
the rod. It is
also advantageous for the device to comprise a plug closing the mounting hole
to prevent
dirt and stones from entering through the mounting hole.
Another preferred embodiment of a locking device according to the invention,
equivalent to
the preceding embodiment but "inverted", is when the locking device comprises
a rod with a
first end fixed to the locking element and a second end housed inside a cavity
arranged in
the internal element, where the second end is suitable for being moved
according to the
direction of movement along the cavity, where the cavity has an opening
oriented towards
the locking element and with the rod going through same, and where the elastic
means are
arranged between the second end of the rod and the opening. Like in the
previous case, it is
advantageous for the first end of the rod to be screwed to the locking
element, for the internal
element to have a mounting hole coaxial with the direction of movement and
with a diameter
greater than the maximum diameter of the rod such that the rod is suitable for
being housed
in the cavity through the mounting hole, and for the device to comprise a plug
closing the
mounting hole.
In a further preferred embodiment of a locking device according to the
invention is when the
device comprises a capsule housing therein the internal element and at least
the internal end
of the locking element and, additionally, the device comprises a rod with a
first end fixed to
the locking element and a second end housed inside a hollow space arranged in
the capsule
between the internal element and an inner end of the capsule opposed to an
open end of the
capsule, where the second end is suitable for being moved according to the
direction of
movement along the hollow space, where the internal element has a central
opening
communicating the locking element with the hollow space and with the rod going
through the
central opening, and where the elastic means are arranged between the second
end of the
rod and the central opening.
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 11 - PC
T/EP2020/059389
This last embodiment has some advantages:
- it allows to use stronger elastic means, in particular stronger springs,
as they can have a
greater outer diameter.
- it is easy to manufacture and to assemble.
- if the evacuation of the compressed air through the air discharge means,
is not possible (or
only partly possible), this embodiment offers two improvements: the stronger
elastic means
will compress further the air and the hollow space provides more room in which
the air can
be compressed (meaning a lower compression rate).
- the inner end of the capsule is closed, so that a welding step is avoided.
In general, it is
advantageous that the inner end is closed (directly i.e., the capsule having a
base wall, or by
welding the base of the internal element to the inner end of the capsule) in
order to avoid
that the earth particles and dust go into the mechanism of the locking device.
- it is possible to deliver to the user a single assembly (i.e., not a
plurality of parts). This is
particularly interesting in the case when the device comprises two locking
elements, with two
movement means and two elastic means, as, with this preferred alternative, a
locking device
having only one capsule with all the remaining elements inside and fixed, can
be assembled
and delivered to the user.
In this last embodiment, preferably the first end of the rod is screwed to the
locking element
or, alternatively, it is fixed to the locking element through a hinged joint.
It can generally be considered that the elastic means have a length D in an
unloaded state,
measured in the sense of the direction of movement, and are suitable for being
compressed
at most to a length T, measured in the sense of the direction of movement, and
that the
locking element and the internal element separate a distance E upon moving
from the
retracted position to the extended position, measured in the sense of said
direction of
movement. Advantageously, the difference between D and T is greater than or
equal to E. It
is thereby assured that the elastic means are not compressed above their
allowable value.
In general, one advantage of the present invention is that the elastic means
exert a force
which helps to retract the locking device. This allows providing another
advantageous
solution which is achieved when the elastic means are in a partially
compressed state when
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 12 -
PCT/EP2020/059389
the locking element and the internal element are in the retracted position. It
is thereby
assured that the elastic means are exerting a force along the entire path
between the
deployed position and retracted position, which assures that the locking
element reaches the
retracted position completely (i.e., it prevents the risk of being slightly
deployed, which may
occur if the elastic means stop exerting any force in the retracted position).
Additionally, the
elastic means preventing the locking device from moving out of its retracted
position in an
unwanted manner during the undesired handling thereof, is also achieved. In
this case,
taking into account the definition of T and E indicated above, and considering
that the elastic
means in the partially compressed state have a length P, measured in the sense
of said
direction of movement, then it is advantageous for the difference between P
and T to be
greater than or equal to E, to assure that the elastic means are not
compressed above their
allowable value.
Another advantageous embodiment of the invention is when the locking device
comprises:
- a second locking element identical to the aforementioned locking element,
- second movement means identical to the aforementioned movement means and
suitable
for moving the second locking element with respect to the internal element, in
a reversible
manner, between a retracted position and an extended position, where the
movement
between the retracted position and the extended position takes place in the
same direction
of movement indicated above,
- second elastic means identical to the elastic means indicated above
which, in the extended
position, exert a force in the direction of the direction of movement that
tends to move the
second locking element closer to the internal element.
Essentially, this final embodiment consists of a locking device extending at
both ends. It is
common for the housing in the nose of the support to be a through hole and for
the wear
element to have two holes, each of them located on opposite walls of the
cavity. In these
cases, the locking device is to be fitted in both holes, such that the wear
element is locked
at two points. This final embodiment allows achieving this objective.
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 13 -
PCT/EP2020/059389
Brief Description of the Drawings
Other advantages and features of the invention will become apparent from the
following
description, in which preferred embodiments of the invention are described in
a non-limiting
manner in reference to the attached drawings. In the drawings:
Figure 1 shows a perspective view of a wear element partially assembled on a
support and
an exploded view of a first embodiment of a locking device according to the
invention.
Figures 2 to 5 show a perspective view and top, front, and side views,
respectively, of the
locking device of Figure 1 in the extended (or deployed) position.
Figures 6 and 7 show front and side views, respectively, of the locking device
of Figures 2 to
5, without the capsule.
Figure 8 shows a view equivalent to Figure 6, but with the locking device in
the retracted
position.
Figure 9 shows a longitudinal section view, according to the direction of
movement, of the
locking device of Figure 8.
Figure 10 shows a longitudinal section view, according to the direction of
movement, of the
locking device of Figure 6.
Figure 11 shows a perspective view of a support in which two locking elements
according to
the invention are introduced.
Figure 12 shows an exploded view of a second embodiment of a locking device
according to
the invention.
Figure 13 shows a top view of the locking device of Figure 12.
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 14 -
PCT/EP2020/059389
Figure 14 shows a longitudinal section view, according to the direction of
movement, of the
locking device of Figure 12 in the retracted position.
Figure 15 shows a longitudinal section view, according to the direction of
movement, of the
locking device of Figure 12 in the extended position.
Figures 16-18 show details relating to an air discharge system according to
the invention.
Figure 19 shows a perspective view of another embodiment of a locking device,
without the
capsule.
Figure 20 shows a perspective view of the internal element of the locking
device of Figure
19.
Figure 21 shows a side view of a further embodiment of a locking device,
without the capsule.
Figure 22 shows an exploded view of the locking device of Figure 21.
Figures 23 and 24 show a longitudinal section view, according to the direction
of movement,
of the locking device of Figure 21, in a retracted position (Figure 23) and in
an extended
position (Figure 24).
Figure 25 shows an equivalent view to Figure 24 but of another embodiment of
the locking
device.
Figures 26 and 27 show a longitudinal section view of two possible capsules
for the locking
device of Figure 21.
Detailed Description of Embodiments of the Invention
Figures 1 to 10 show a first embodiment of a retaining device according to the
invention. The
device comprises a locking element 1, an internal element 2, a rod 3, a spring
4, and a closing
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 15 -
PCT/EP2020/059389
element 5. The locking element 1 has an 0-ring 6 extending along its side
perimeter. These
components are housed inside a capsule 7. When the locking device is in the
extended
position, a locking end 8 of the locking element 1 projects from the capsule 7
(see Figures 2,
4, and 5).
The device is housed in a housing 9 provided in the nose of a support 10 (in
Figure 1, a weld
on nose). Next, a wear element 11 (in Figure 1, a tooth) is positioned over
the support 10.
The wear element 11 has a cavity suitable for housing therein the nose of the
support 10 and
has a hole 12 in one of the side walls of the cavity. In the assembled
position, the hole 12 at
least partially overlaps the housing 9, such that the locking end 8 can
project from the housing
9 and be housed in the hole 12, which causes the locking of the wear element
11 in the
support 10.
The locking element 1 and the internal element 2 are substantially cylindrical
bodies suitable
for being housed inside the capsule 7, which is also cylindrical. The two
cylindrical bodies
are arranged such that their axes coincide (and they coincide with the
direction of
movement). Therefore, the cylindrical body forming the locking element 1 has a
base facing
a base of the cylindrical body forming the internal element 2.
The internal element 2 is welded to the capsule 7 at the lower part of both
elements (see
Figures 14 and 15), such that the internal element 2 is fixed to the capsule
7, whereas the
locking element 1 can rotate with respect to the capsule 7. In turn, the
capsule 7 has a side
projection 14 which prevents the capsule 7 from being able to rotate with
respect to the
housing 9. This side projection 14 thereby defines anti-rotation means.
In this first embodiment, the movement means comprise rotation means. The
rotation means
include a first inclined surface 15 arranged at the base of the internal
element 2 facing the
locking element 1 and a second inclined surface 16 at the base of the locking
element 1
facing the internal element 2. The first and the second inclined surfaces 15
and 16 have a
helical configuration, such that they can slide with respect to one another
upon rotation of
the locking element 1 with respect to the internal element 2. Due to this
helical configuration,
the rotation also causes a movement in the direction of the axis of the
helical surface, which
is therefore the direction of movement. In fact, the internal element 2 has
two first inclined
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 16 -
PCT/EP2020/059389
surfaces 15 and the locking element 1 also has two second inclined surfaces
16, such that
each first inclined surface 15 is paired with a second inclined surface 16.
At the end of each inclined surface 15 and 16 there is a seating surface 17
(the first seating
surface and the second seating surface, respectively). When the locking device
is in its
extended position (see Figures 6 and 7), the locking element 1 and the
internal element 2
are supported on one another through their respective seating surfaces 17,
which thereby
define a stable locking position.
The seating surface 17 of the internal element 2 comprises a first elevation
18 at the end
opposite the attachment area between the seating surface 17 and the first
inclined surface
15. This first elevation 18 prevents the locking element 1 from being
inadvertently rotated
beyond this point, which would cause it to be abruptly retracted. The seating
surface 17 of
the internal element 2 also comprises a second elevation 19 at the end close
to the
attachment area between the seating surface 17 and the first inclined surface
15. In this
case, the purpose of this second elevation 19 is to prevent, due to the
vibrations and shaking
to which the locking device is subjected during use, the locking element 1
from being able to
move from the stable position defined by the seating surfaces 17 and being
retracted due to
the force of the elastic means.
As can be seen, in this first embodiment the transition from the retracted to
the deployed
position (and vice versa) is achieved by means of a 90 rotation (a fourth of
a turn). To
perform this rotation, the base of the locking element 1 which is at the
locking end 8, i.e., the
base opposite the internal element 2, has an hole 20 suitable for inserting a
rotating tool.
This hole 20 has a shape with a substantially square cross-section.
The elastic means comprise a coil spring 4. The spring 4 is assembled around a
rod 3. The
rod 3 has a first end 21 fixed to the internal element 2 by means of a screw
13. The second
end 23 of the rod 3 is housed inside a cavity 24 arranged in the locking
element 1 and is
suitable for being moved according to the direction of movement along the
cavity 24 when
the locking device is extended or retracted. The second end 23 has a head 25
retaining the
spring 4. The cavity 24 has an opening 26 oriented towards the internal
element 2 and with
the rod 3 going through same. The opening 26 has a smaller size than the
spring 4, such
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 17 -
PCT/EP2020/059389
that the spring 4 is retained between the head 25 and the opening 26. To
facilitate the
assembly of the ensemble, the opening 26 is in a closing element 5 which is
screwed to the
locking element 1. The closing element 5 has a larger diameter than the head
25, such that
it is possible to introduce the head 25 and the spring 4 into the cavity 24
and then screw the
closing element 5 in the locking element 1.
In the present description and claims all the movements between the different
elements of
the device have been indicated in relative terms and merely for the purpose of
explaining the
operation of the device. Actually, the internal element 2 is fixed to the
capsule 7 (for example,
by welding) and the capsule 7 is fitted in the housing 9, since it is larger
than the hole 12.
Therefore, what actually moves with respect to the support 10 and the wear
element 11 is
the locking element 1.
Figures 12 to 18 show a second embodiment of a locking device according to the
invention.
The main difference between this second embodiment and the embodiment
described above
resides in the fixing of the rod 3 and the manner of assembling it in the
device. In this case,
the locking element 1 has a mounting hole 27 coaxial with the direction of
movement and
with a diameter greater than the maximum diameter of the rod 3 (i.e., the
maximum diameter
defined by the head 25). The rod 3 can therefore be housed in the cavity 24 by
introducing it
through the mounting hole 27. The end of the rod 3 opposite the head 25 is
threaded and
goes through the opening 26 (which is smaller than the spring 4 in this case,
since the spring
4 is also introduced in the cavity 24 through the mounting hole 27). This
threaded end can
be screwed to the internal element 2, such that the ensemble is assembled. A
plug 28 closes
the mounting hole 27.
In the two embodiments shown, the locking element is larger than the internal
element and
the cavity in which the head of the rod and the spring are housed is in the
locking element.
However, it would be possible to design a locking device in which the rod is
fixed to the
locking element and the internal element is large enough to house therein a
cavity containing
the head of the rod and the spring, i.e., a configuration "symmetrical" to the
one shown in the
preceding examples.
The second embodiment of Figures 12 to 18 also includes air discharge means
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 18 -
PCT/EP2020/059389
communicating the space comprised between the locking element 1 and the
internal element
2 with the outside. However, these air discharge means may be included in a
manner that is
exactly identical in the first embodiment or the "symmetrical" embodiments
indicated above.
The purpose of these air discharge means is to prevent the overpressure
generated in the
space comprised between the locking element 1 and the internal element 2 upon
trying to
retract the locking device. The 0-ring 6 hinders the passage of air from this
inner space to
the outside. To prevent this overpressure, the locking device includes an air
discharge
conduit 29 extending between this inner space and an upper end 30 of the air
discharge
conduit 29. The position of this upper end 30 is important. The purpose of the
0-ring 6 is to
prevent dirt and/or fines from getting into the locking device. Therefore,
when the locking
device is extended, it is important for the 0-ring 6 to be able to perform its
function, so the
upper end 30 of the air discharge conduit 29 must be "below" the 0-ring 6 (see
Figure 15
and the enlarged detail of Figure 17). When the locking device is retracted,
the upper end 30
of the air discharge conduit 29 must be "above" the 0-ring 6, such that
communication is
established between the inner space and the outside which allows the exit of
the air (see
Figure 14 and the enlarged detail of Figure 16). The most advantageous aspect
is that the
upper end 30 of the air discharge conduit 29 is close to (below) the 0-ring 6
when the locking
device is extended, such that upon initiating retraction, the upper end 30 is
quickly located
above the 0-ring 6 and the overpressure generated in the inner space is as low
as possible.
The air discharge conduit 29 has been formed from a cavity or gap between the
outer side
surface of the locking element 1 and the inner side surface of the capsule 7.
Specifically, the
inner side surface of the capsule 7 is not completely cylindrical, but rather
has a segment
(the one corresponding to the air discharge conduit 29) that is oval-shaped or
ellipsoidal (see
Figure 18, which schematically shows a cross-section of the locking element 1
and the
capsule 7). Therefore, between both sides surfaces there is a gap that is
sufficient for
allowing the passage of air. In any case, this gap must large enough so as to
assure that the
0-ring 6 no longer applies a sealed closure.
Figures 19 and 20 show another embodiment of a locking device according to the
invention.
The same references have been used for those elements which are common with
the
preceding embodiments. In this new embodiment, the main difference resides in
the fact that
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 19 -
PCT/EP2020/059389
the base of the internal element 2 facing the locking element 1 comprises a
first guide surface
31 opposite the first inclined surface 15 and the base of the locking element
1 facing the
internal element 2 comprises a second guide surface 32 opposite the second
inclined surface
16. In other words, the locking element 1 has a helical finger 33 which is
suitable for being
housed in a helical housing 34 arranged in the internal element 2. The helical
finger 33
defines the second inclined surface 16 and the second guide surface 32, which
are on
opposite sides of the helical finger 33. In turn, the helical housing 34
defines the first inclined
surface 15 and the first guide surface 31, which are two opposing faces of the
helical housing
34.
As can be seen in Figure 19, in the retracted position the first guide surface
31 and the
second guide surface 32 are superimposed on one another. Upon rotation of the
locking
element 1 to take it to its extended position, the second guide surface 32
slides along the
first guide surface 31.
The second elevation 19 generally has a maximum elevation point 35 (in the
solution shown
in the drawings it is an arris) having a maximum height, in the sense of the
direction of
movement, with respect to the seating surface 17. This maximum height is
determined such
that it is assured that the locking element 1 cannot "jump out" of the seating
surface 17 onto
the first inclined surface 15, but it is low enough such that it can be
overcome when taking
the locking element 1 to its extended position. The first guide surface 31
(which corresponds
to the first inclined surface 15 which, in turn, corresponds to the first
seating surface 17)
extends, in the direction of movement, beyond the maximum elevation point 35.
It is thereby
assured that when the locking element 1 is in its extended position and
rotation starts to take
the locking element 1 to its retracted position, the two guide surfaces 31 and
32 immediately
come into contact once the locking element 1 has overcome the maximum
elevation point
(35) of the second elevation 19.
Figure 11 shows an example in which two locking devices are used for fixing a
wear element
to a support. However, it would also be possible to use one locking device
which, while
having a single internal element, has two locking elements extending on each
side of the
internal element, as discussed above.
-" PDF f =n.
CA 03135312 2021-09-28
WO 2020/201418 - 20 -
PCT/EP2020/059389
Figures 21 to 24 show another preferred embodiment of a locking device
according to the
invention. The same references have been used for those elements which are
common with
the preceding embodiments, although some of them are organized in a different
way. The
device comprises a locking element 1, an internal element 2, a rod 3 and a
spring 4. The
locking element 1 has an 0-ring 6 extending along its side perimeter. These
components are
housed inside a capsule 7. When the locking device is in the extended
position, a locking
end 8 of the locking element 1 projects from the capsule 7 (see Figures 23 and
24). The
internal element 2 is fixed to the capsule 7 through fixing means 41
(preferably a bolt) at an
intermediate point of the capsule 7, so that between the bottom of the
internal element 2 and
the inner end 37 of the capsule 7 there is a hollow space 36. As in previous
embodiments,
the capsule 7 has a side projection 14 which prevents the capsule 7 from being
able to rotate
with respect to the housing (9). The main difference between this embodiment
and the
previous ones resides in the fixing and positioning of the rod 3 and the
spring 4. In this case,
the rod 3 has the first end 21 that is threaded, and it is threaded to the
locking element 1.
The second end 23 of the rod 3 is housed inside the hollow space 36 and is
suitable for being
moved according to the direction of movement along the hollow space 36 when
the locking
device is extended or retracted. The second end 23 has a head 25 retaining the
spring 4.
The internal element 2 has a central opening 39 communication the locking
element 1 with
the hollow space 36 and with the rod 3 going through this central opening 39.
The central
opening 39 has a smaller size than the spring 4, such that the spring 4 is
retained between
the head 25 and the central opening 39.
Figure 25 shows a variant of this last embodiment in which the first end 21 of
the rod 3 is not
threaded to the locking element 1 but fixed to the locking element 1 through a
hinged joint
(40).
Figure 26 shows one embodiment of locking device that is formed by two locking
devices as
shown in Figures 21 to 24 faced opposite to each other and with the inner end
37 of both
capsules 7 welded together. Figure 27 is a variant of the locking device of
Figure 26 in which,
instead of having two capsules 7 welded together, the device has only one
capsule 7.
-" PDF f =n.
