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TITLE: "Device for securing teeth to tooth adapters of an
earth-moving machine through pins"
***
DESCRIPTION
Technical field
The present invention relates to a device for securing
implements to heavy machines by means of pins; in
particular, said implements may be teeth for earth-moving
machines.
Background art
In the field of heavy machines, devices are known
which are used for securing implements to such machines by
means of pins. Such devices can be used in combination with
different type of machines, including earth-moving
machines.
With particular reference to the field of earth-moving
machines, excavators, for example, are equipped with a
bucket or a blade connected to the end of a movable arm for
breaking up and moving earth, the characteristics of which
may vary extensively.
The bucket of such machines is generally fitted with
one or more teeth, or tips, which can be connected thereto
in a removable manner, so that such teeth can be replaced
when worn or should they break during use, without
requiring the replacement of the whole bucket, which would
be a very expensive and difficult task.
In particular, the teeth are secured in different ways
to protuberances, also known as tooth adapters, arranged
along the lower edge of the bucket. An old fastening method
requires the use of a pin or key to be forcedly driven with
a hammer into a series of holes between the tooth adapter
of the bucket and the tooth; once inserted, the pin is
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received into a deformable element, e.g. a rubber element
or ring, which can generate friction that holds the various
pieces in position while using the machine.
This method is, of course, not very safe and
practical, in particular when small excavators must be used
and the room between the tooth adapters of the bucket is
not enough to allow the use of a hammer. In addition, when
big pins are used much force needs to be exerted with the
hammer in order to insert the pin and create the required
friction with the ring.
Another problem is the low level of safety for
operators using hammers or clubs for inserting the pin.
A further drawback is that such devices work mainly by
friction, and the pin has much clearance within the spaces
in which it is inserted; therefore, there is more
likelihood that the pin might come off, particularly when
the bucket is working into hard ground or in the presence
of water: in such cases, vibrations and water will remove
the thin layer of earth deposited in the interstices
between the tooth, the bucket and the fastening device,
which is useful for increasing friction and holding the
pieces in mutual contact.
When the machine is in use, one or more pins coming
off will cause a number of problems, including: higher
costs; danger due to fall of tips from the bucket raised
above ground; wear of the "uncovered" tooth adapter, and
hence of the bucket itself.
For these reasons, in recent years less "invasive"
fastening techniques have been developed, which are however
not very practical, especially because they are prevalently
intended for use in building yard environments, where water
and debris are often present.
International application number:162014064394
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For example, document ES1068766U illustrates a device
comprising a partially threaded through pin, intended for
cooperating with a threaded washer having a locking means,
e.g. a groove, into which an operator inserts a screw or
pin for holding it in position, thereby preventing the
parts from coming out of their seat.
An additional drawback is that the (big) through pin
and the (small) locking screw must presumably be screwed by
using two different wrenches, resulting in a more complex
replacement operation. Moreover, when working in an outdoor
environment some of these parts may easily get lost, in
particular the locking screw. <Pages 3a, 3b, 3c>
Summary of the invention
It is one object of the present invention to provide a
device for securing teeth to a tooth adapted of an earth-
moving machine by means of pins, which can be produced in a
simple and economical manner.
It is a further object of the present invention to
provide a device having a number of functional features,
including ease of installation and removal, operator
safety, and reliability, mainly due to a reduced risk of
losing teeth from the tooth adapters.
In particular, according to one or more embodiments of
the present invention, a pin is used which can be manually
inserted into and extracted from suitable holes without
requiring the use of hammers, clubs or the like; this
technology is also referred to as "hammerless".
According to the present invention, this and other
objects are achieved through a device made in accordance
with the appended claim 1.
It is to be understood that the appended claims are an
integral part of the technical teachings provided in the
AMENDED SHEET
International application number:162014064394
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In the art are known some devices as described in
their respective documents.
For example, W02004007852 Al discloses a system for
coupling excavation equipment components is provided. The
system includes a retainer pin having first and second
detents which are extendable axially from a surface of the
retainer pin, in response to rotation of a valve seated at
least partially within a cylindrical bore which extends at
least partially through the retainer pin. In accordance
with the particular embodiment, the valve includes at least
one slotted portion configured to receive the detents at
least partially therein, when the detents are in a
retracted position.
According to US4067657, a ripper tip is mounted on the
end of a shank by a cylindrical pin disposed in aligned
bores formed therethrough. A camming member is reciprocally
mounted in each end of the pin to each have a first end
thereof engage the tip in bearing contact therewith. A set
screw is threadably mounted in the pin to engage a second
end of each camming member to urge it into such bearing
contact. In a first embodiment, the camming member is
disposed perpendicular relative to the longitudinal axis of
the pin and the set screw is disposed in parallel
relationship relative thereto whereas in a second
embodiment the camming member and set screw are each
disposed at an acute angle relative to the longitudinal
axis of the pin.
EP0343191 discloses a pin retainer assembly having a
keeper means for retaining earthworking tips on adapters.
Positive retention of earthworking tips on their adapters
by their retaining pins during its work cycle is extremely
important from an operational as well as a cost standpoint.
AMENDED SHEET
International application number:162014064394
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Keeper means for the pin is captured in a recess between a
nose of the adapter and a sidewall of the tips and includes
a washer slidably disposed on the pin and a resilient
retaining ring having a predetermined radial thickness
disposed in locking engagement in a groove on the pin and a
groove of the washer. One of the grooves in the pin and the
washer has a depth equal to or greater than the
predetermined radial thickness of the retaining ring and
the other one of the grooves has a depth sufficient to
prevent camming of the ring out of the groove and to
provide substantially the maximum cross-section width of
the ring in shear. In order to disassemble the pin, the
ring must be sheared or the washer fractured.
US2002023375 Al discloses a tooth assembly for an
excavating machine includes an adapter having first and
second surfaces and first and second sides. The first
surface of the adapter is generally tapered and converges
toward a first end of the adapter. A tooth point is coupled
with the adapter at the first end of the adapter, and the
tooth point has a contact edge opposite the first end of
the adapter. The tooth point also includes first and second
sides, the first side having a slot adapted to receive a
non-rotation ridge of a retainer pin to prevent rotation of
the retainer pin with respect to the tooth point. A second
end of the adapter is adapted to be removably coupled with
a tooth horn. The tooth assembly further includes a central
portion extending generally from the first side of the
adapter to the second side, the central portion defining a
central bore. In accordance with a particular embodiment, a
retainer pin with a non-rotation ridge may be coupled with
the central portion of the tooth assemble at least
partially within the central bore.
AMENDED SHEET
International application number:162014064394
Article 34 Am(pc-.-
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According to US6092958, a bottom mount pin retainer is
disclosed for retaining a mounting pin detachably mounting
a first member of a ground engaging tool to a second member
thereof. The pin retainer utilizes a retainer assemblage
that is adapted to relieve a snap-ring employed for
retaining the pin from high axial loads in an upward
direction while preventing axial movement of the pin in a
downward direction. A non-load bearing member used has
sufficient load bearing capacity to restrain the upward
movement of the snap-ring during the insertion of the pin
into the pin openings in order to seat the snap-ring in its
snap-ring groove in the pin.
AMENDED SHEET
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following detailed description of the invention.
Brief description of the drawings
Further features and advantages of the present
invention will become apparent from the following detailed
description, which is supplied by way of non-limiting
example with reference to the annexed drawings, wherein:
- Figure 1 is a view of an implement connected to a
machine by means of the present invention;
- Figure 2 is an exploded view of one example of a
device in accordance with the present invention;
- Figure 3 is a sectional view of the device shown in
Figure 2, in a retracted condition;
- Figure 4 is a sectional view of the device shown in
Figure 2, in an extracted condition;
- Figure
5 is a sectional view along line V-V of the
device shown in Figure 4;
- Figure 6 is a sectional view of a second embodiment of
the device;
- Figure 7 is a sectional view along line VII-VII of the
device shown in Figure 6.
Detailed description of the invention
With reference to the above-listed drawings, a device
1 connects an implement 3 to an implement carrier 4. In
particular, implement 3 is a tooth 3, and implement carrier
4 is a tooth adapter 4 of a bucket 5 belonging to an earth-
moving machine, e.g. an excavator useful for
excavating/moving earth.
As will be apparent to a man skilled in the art,
implement carriers 4, in this case tooth adapters 4 of
bucket 5, are shaped in such a way as to at least partially
enter a cavity formed in implements 3, which are intended
for being mounted on the machine and replaced as necessary.
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It is therefore necessary to use a device capable of firmly
keeping implement 3 in contact with implement carrier 4
while the machine is in use.
"Hammerless" device 1 comprises a pin 10 to be
5 removably inserted through at least one first aperture 12
on an implement 3 and one second aperture 14 on an
implement carrier 4 of a machine.
Device 1 comprises at least one expanding element 20
adapted to reversibly switch between a retracted position,
in which said expanding element 20 is at a minimum distance
from the longitudinal axis x-x of said pin 10, to an
extracted position, in which said expanding element 20 is
at a maximum distance from the longitudinal axis x-x of
said pin 10.
In accordance with an advantageous embodiment
illustrated in Figures 1 to 5, expanding element 20 is
adapted to reversibly switch from said retracted position
to said extracted position by moving in a plane
substantially perpendicular to the longitudinal axis x-x of
said pin 10. In other words, expanding element 20 is
adapted to reversibly switch from the retracted position to
the extracted position by moving transversally relative to
the longitudinal axis x-x of pin 10.
Device 1 further comprises at least one retaining
element 22 associated with at least one of said first and
second apertures 12, 14, and provided with at least one
seat 24 for at least partially receiving said at least one
expanding element 20 when said at least one expanding
element 20 is in said extracted position.
Retaining element 22 is associated with at least one
of the first and second apertures 12, 14 through methods
which are per se known; for example, it is possible that a
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cavity, also known as "counterbore", is formed on at least
one of said first and second apertures 12, 14, into which
retaining element 22 can be at least partially inserted.
Figure 1 shows one advantageous embodiment of the
present invention, wherein tooth 3 has a cavity into which
tooth adapter 4 is inserted, and two first apertures 12 are
present on the faces that delimit the cavity; pin 10 is
then inserted through the first apertures 12 on tooth 3 and
through the second aperture 14 on tooth adapter 4 of bucket
5.
That part of tooth adapter 4 which must be inserted
into the cavity of tooth 3 is also known as "catch";
however, reference will only be made below to tooth adapter
4 without departing from the protection scope of the
present invention.
Figure 2 shows one advantageous embodiment of the
present invention, wherein pin 10 has a substantially
cylindrical outer surface; other shapes are however also
conceivable, e.g. prismatic with a square, rectangular,
triangular, polygonal, etc. cross-section.
Expanding element 20 comprises a pair of balls on
diametrically opposed sides relative to axis x-x of pin 10,
which are adapted to move along a radial path while
reversibly switching between the extracted and retracted
positions.
Further variants are also conceivable, wherein the pin
contains a different number of expanding elements 20 (or
even just one).
In addition, expanding element 20 may, still in
accordance with the present invention, have other non-
limiting shapes, including: bar, parallelepiped, cylinder,
ellipse, etc.
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In other words, expanding element 20 (which in the
case illustrated herein is spherical in shape) is a movable
element, preferably a sliding element, susceptible of
moving between the extracted condition and the retracted
condition.
Retaining element 22 shown herein has a substantially
annular shape, and includes a seat 24 formed on the face of
retaining element 22 which is closer to pin 10. Said seat
24 is a recess so shaped as to easily receive expanding
element 20, which in this case consists of a pair of balls.
In the illustrated example, seat 24 advantageously has
a continuous annular development along the entire retaining
element 22, so as to be able to receive expanding element
irrespective of the angle between pin 10 and retaining
15 element 22.
In accordance with further variant embodiments (not
shown), device 1 comprises multiple seats 24 arranged on
retaining element 22, each one intended for receiving one
or more expanding elements 20.
20 Retaining element 22 may have different shapes,
preferably compliant with the shape of the cross-section of
pin 10, such as: square, rectangular, triangular,
polygonal, open section, "C" section, etc.
With reference to Figure 3, device 1 is in the
retracted position, in which expanding elements 20 (in this
case, balls) are close to axis x-x and do not protrude past
the outer surface of pin 10. Balls 20 are not in contact
with retaining element 22, and therefore a relative
movement (along the axis x-x) is possible between pin 10
and retaining element 22, which allows pin 10 to be
extracted from apertures 12, 14 and tooth 3 to be
disengaged from tooth adapter 4 of bucket 5.
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In the illustrated embodiment, device 1 comprises at
least one duct 26, formed in pin 10 and allowing the
reversible movement of the at least one expanding element
20 between the extracted condition and the retracted
condition.
Figure 4 shows device 1 in the extracted position, in
which balls 20 protrude at least partially past the outer
surface of pin 10 for mechanically cooperating with
retaining element 22 to prevent any relative movement
between pin 10 and retaining element 22, so as to firmly
engage tooth 3 with tooth adapter 4 of bucket 5.
Device 1 further comprises an actuator 30 adapted to
allow said at least one expanding element 20 to reversibly
switch from the retracted position to the extracted
position.
In particular, as shown in Figures 3 and 4, actuator
30 is a threaded screw to be at least partially inserted
into a hole 32 provided on the pin. A user will act upon
screw 30, typically by means of a wrench, in order to bring
said screw 30 closer to the at least one expanding element
20 until they come in contact with each other; at this
point, the tip of screw 30 will push, as it goes forwards,
expanding element 20 towards a position farther away from
axis x-x, i.e. towards the extracted position, thus
securing tooth 3 to bucket 5 and allowing the excavating
machine to be normally used. Likewise, when tooth 3 needs
to be replaced, the user will undo screw 30 to move the at
least one expanding element 20 into the retracted
condition, thus allowing removal of pin 10.
In Figure 5 two ducts 26 are visible, through which
the two balls 20 slide in order to switch from the
retracted position to the extracted position, and vice
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versa, under the action of actuator 30. Ducts 26 are
arranged radially relative to the axis x-x of pin 10, and
are substantially straight.
In this variant, screw 30 is coaxial to pin 10.
However, actuator 30 may also move along an axis that
does not coincide with axis x-x.
If actuator 30 is a threaded screw, it is also
conceivable to use a self-locking element, or self-locking
material, suitable for preventing the screw from loosing
accidentally and causing expanding element 20 to move from
the extracted position to the retracted position.
According to a further embodiment (not shown),
actuator 30 can move said at least one expanding element 20
by means of a gear or a gear system.
According to yet another embodiment, actuator 30 can
move said at least one expanding element 20 by means of a
lever or a lever system.
For simplicity, retaining element 22 will be referred
to below as a "ring", without however limiting the scope of
the invention.
Figures 6 and 7 illustrate a second embodiment of the
present invention, which comprises an elastic means 34
capable for bringing said at least one expanding element 20
towards one of the extracted position and the retracted
position. Advantageously, elastic means 34 is a spring,
such as a coil spring. Other per se known elastic means 34
may alternatively be used, such as, for example, a disk
spring, or an elastically deformable element, such as a
reed or a small bar, a rubber element, or chemical
materials having an elastic behaviour.
Preferably, elastic means 34 is adapted to bring
expanding element 20 towards the extracted position.
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After having inserted pin 10 through holes 12, 14 of
tooth 3 and of tooth adapter 4, the user will associate the
ring with pin 10; then, by operating actuator 30, the user
will bring the expanding element into the extracted
5 condition in order to mechanically secure the ring to pin
10, thereby preventing them from mutually sliding along
axis x-x, hence securing tooth 3 to tooth adapter 4. Thanks
to the presence of elastic means 34, which will tend to
hold expanding elements 20 in the extracted position, in
10 order to place the ring into the correct position along
axis x-x of pin 10 the user will have to slide the ring
along pin 10 against the resistance opposed by elastic
means 34, which will tend to hold expanding elements 20 in
the extracted condition. In fact, when pin 10 is not
associated with the ring, expanding elements 20 protrude at
least partially from the external side surface of pin 10,
and therefore the ring will encounter an obstacle while
sliding along pin 10.
In the absence of elastic means 34, there is a risk
that the ring might be incorrectly secured to pin 10. In
fact, in difficult working conditions the user might bring
expanding element 20 into the extracted condition without
however positioning the ring to correctly receive expanding
element 20 (i.e. without the ring and pin 10 being properly
aligned along axis x-x). In such a situation, pin 10 might
slide off the ring, resulting in the risk that pin 10 might
come out of the holes of tooth 3 and of tooth adapter 4,
thus causing the tooth to be detached from the tooth
adapter.
Therefore, the presence of elastic means 34 prevents
the risk that the ring might be incorrectly secured to pin
10, because it will be easy for the user to understand when
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pin 10 and the ring are in the proper mutual position, and
then to operate actuator 30 in order to lock expanding
elements 20 in the extracted condition, thus securing tooth
3 to tooth adapter 4. After the ring has been properly
positioned on pin 10, expanding elements 20 will, through
the effect of elastic means 34, move away from axis x-x of
pin 10, arranging themselves in the extracted condition in
abutment with seat 24 of the ring; at this stage, a short
vibration and a "clack" noise may be generated because of
the sudden movement of expanding elements 20. The user can
thus easily perceive that pin 10 and the ring have been
properly engaged.
In the illustrated example, elastic means 34 is
positioned between two expanding elements 20, and exerts a
repulsion force on such expanding elements 20 that tends to
move them away from axis x-x into the extracted position. A
first end (on the right in the drawing) of elastic means 34
is in contact with one expanding element 20, while a second
end (on the left) of elastic means 34 is in contact with
the other expanding element 20. Elastic means 34 is
arranged in ducts 26.
According to another variant (not shown), pin 10 may
be equipped with one elastic means 34 for each expanding
element 20. Elastic means 34 may be associated with an
abutment portion of pin 10; thus, a first end of elastic
means 34 is in contact with one expanding element 20, and a
second end of elastic means 34 is associated with the
abutment portion.
With particular reference to the illustrated
embodiment comprehensive of elastic means 34, in the
absence of actuator 30 one can engage/disengage pin 10 and
the ring by applying a force overcoming the force exerted
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by elastic means 34 to hold the expanding elements 20 in
the extracted condition, thus allowing mutual sliding
between pin 10 and the ring. In this case, actuator 30 will
contribute to hold expanding means 20 more firmly in said
extracted condition in contact with the ring, thus
minimizing the risk that pin 10 and ring might accidentally
come off.
In the particular variant embodiment shown in Figures
6 and 7, the outer surface of pin 10 has a shape that
limits the sliding of the ring along axis x-x of the same
pin 10.
Advantageously, the outer surface of pin 10 has two
different cross-sections along its axis x-x (the cross-
sections are perpendicular to the axis x-x). In particular,
pin 10 includes a first portion 10a with a smaller cross-
section and a second portion 10b with a larger cross-
section. In the variant that uses a substantially
cylindrical pin 10, the two cross-sections are two
circumferences having different diameters.
Portion 10a of pin 10 that extends from a first end of
the latter (the upper end in Figure 6) to expanding
elements 20 has a smaller cross-section; the remaining
portion 10b of pin 10 has a larger cross-section. Thus, the
outer surface of pin 10 has a configuration that resembles
two superimposed coaxial cylinders.
The difference between the cross-sections of the two
portions 10a, 10b of the outer surface of pin 10 creates a
projection (i.e. an abutment, a stop portion or the like)
which is useful for limiting the sliding movement of the
ring along pin 10, so that the ring can be correctly
positioned on pin 10 during the insertion step. Therefore,
after having inserted pin 10 through tooth 3 and tooth
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adapter 4, the user will push the ring towards pin 10; the
ring will slide over pin 10 until it meets the projection,
where it will stop. At this point, pin 10 and the ring will
be in the correct mutual position that will allow expanding
elements 20 to move into the extracted condition within
seat 24 of the ring, thereby securing the assembly.
The presence of elastic means 34 and of the projection
on the outer surface of pin 10 allows the operator to
associate together pin 10 and the ring in a faster, easier
and more reliable manner, thereby minimizing the risk of
incorrect assembly and obtaining a confirmation that the
parts have been assembled correctly.
It must be pointed out that the features of elastic
means 34 and of the projection may be individually present
in device 1 of the invention, and that they may be combined
with any other features of the present invention, unless
they are technically incompatible.
As can be seen in some of the drawings, device 1 may
be so shaped as to be able to receive a tool or wrench, so
that said device 1 can be held while an operator is acting
upon actuator 30. For example, if actuator 30 is a screw,
on the side opposite to said screw there may be a housing
adapted to receive a second tool (e.g. an Allen wrench), so
that the necessary torque can be applied without device 1
turning within apertures 12, 14.
Optionally, device 1 comprises a housing formed on pin
10 and shaped for receiving a tool or wrench. Housings are
generally formed at the ends of pin 10, along the
longitudinal axis x-x thereof. Device 1 illustrated in
Figure 6 comprises a pair of housings: the first housing 40
is located at hole 32 that accommodates actuator 30 (upper
part of the drawing), and the second housing 42 is formed
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at the end of portion 10b of the pin (lower part of the
drawing).
Advantageously, device 1 comprises a closing element
50, 52, e.g. a plug or the like, for closing the respective
housing. This will avoid undesired entry of debris and
dirt, ensuring better efficiency and a longer life of
device 1.
Closing element 50, 52 is removable, thus allowing the
tools to be inserted into respective housing 40, 42.
Closing element 50, 52 may be made of any material;
preferably it is made of rubber or plastic. Closing element
50, 52 may have many different shapes, e.g. cylindrical,
truncated cone, parallelepiped, etc.
Of course, without prejudice to the principle of the
invention, the forms of embodiment and the implementation
details may be extensively varied from those described and
illustrated herein by way of non-limiting example, without
however departing from the scope of the invention as set
out in the appended claims.
