U.S. patent application number 13/127059 was filed with the patent office on 2011-12-22 for coupler with coupling status sensors.
This patent application is currently assigned to Miller International Limited. Invention is credited to Doreen Jacqueline Miller, Gary Miller, Ronald Keith Miller.
Application Number | 20110313625 13/127059 |
Document ID | / |
Family ID | 40138247 |
Filed Date | 2011-12-22 |
United States Patent
Application |
20110313625 |
Kind Code |
A1 |
Miller; Gary ; et
al. |
December 22, 2011 |
COUPLER WITH COUPLING STATUS SENSORS
Abstract
A coupler (24) for coupling an accessory (28) to an excavator
arm (12) of an excavator (10), the coupler comprising a first jaw
(30) that points in a generally longitudinal direction relative to
the frame of the coupler (24), the jaw (30) being for receiving a
first attachment pin of an accessory (28) and having a first sensor
(40) for detecting the presence of an attachment pin therein, the
coupler (24) further having a second jaw (32), or a latch (34),
longitudinally spaced from the first jaw (30), and being for
receiving a second attachment pin of the accessory (28), and having
a second sensor (42) for detecting the presence of an attachment
pin therein. The sensors (40, 42) transmit or send signals to a
receiver (46, 48) for notifying the driver of the coupling status
of the coupler (24) with respect to the accessory (28).
Inventors: |
Miller; Gary; (Tyne &
Wear, GB) ; Miller; Ronald Keith; (Newcastle Upon
Tyne, GB) ; Miller; Doreen Jacqueline; (Washington,
GB) |
Assignee: |
Miller International
Limited
Gibrattar
GB
|
Family ID: |
40138247 |
Appl. No.: |
13/127059 |
Filed: |
November 3, 2009 |
PCT Filed: |
November 3, 2009 |
PCT NO: |
PCT/GB2009/002602 |
371 Date: |
May 27, 2011 |
Current U.S.
Class: |
701/50 ;
403/27 |
Current CPC
Class: |
E02F 3/3663 20130101;
E02F 3/365 20130101; E02F 9/26 20130101; Y10T 403/20 20150115 |
Class at
Publication: |
701/50 ;
403/27 |
International
Class: |
E02F 9/24 20060101
E02F009/24; E02F 3/36 20060101 E02F003/36; E02F 9/20 20060101
E02F009/20 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 3, 2008 |
GB |
0820116.2 |
Claims
1. A coupler for coupling an accessory to an excavator arm of an
excavator, the coupler comprising a first jaw that points in a
generally longitudinal direction relative to the frame of the
coupler, the first jaw being configured for receiving a first
attachment pin of an accessory and a second jaw longitudinally
spaced from the first jaw with respect to the frame of the coupler,
the second jaw being configured for receiving a second attachment
pin of the accessory, the second jaw including a latch for locking
the second attachment pin into the second jaw of the coupler,
wherein a sensor is provided for one of the first and second jaws
for detecting the presence or the absence of an attachment pin in
the said first or second jaw and outputting a signal to signify
said detected presence or absence.
2.-41. (canceled)
42. The coupler of claim 1, in combination with a receiving unit or
a transmitter, wherein signals from the sensor are transmitted or
sent along a wire to the receiving unit, or to the transmitter, for
allowing an indication of the sensed information to be passed to a
user.
43. The coupler of claim 1, in combination with a receiving unit or
a transmitter, wherein signals from the sensor are transmitted or
sent wirelessly to the receiving unit, or to the transmitter, for
allowing an indication of the sensed information to be passed to a
user.
44. The coupler of claim 1, in combination with a display, the
display, in use, being located within a cab of the excavator to
whose arm the coupler is attached, wherein the sensed information
from the sensor is displayed on the display
45. The coupler of claim 1, wherein the sensor is one of, or a
combination of one or more of, a strain sensor, a PTM
(push-to-make) switch, a magnetic sensor, an optical sensor and a
capacitance sensor.
46. The coupler of claim 1, wherein a second sensor is provided for
detecting one of the presence of an attachment pin in the second
jaw, and the presence of an attachment pin in or against the
latch.
47. The coupler of claim 46, wherein the second sensor is mounted
directly onto or into a pivoting or sliding latch.
48. The coupler of claim 1, wherein signals from the or each sensor
are transmittable to a receiving unit with a coding, whereby the
source or sources of the transmitted signals, with respect to which
sensor they came from, is discernable by the receiving unit.
49. The coupler of claim 1, provided in combination with an
indicator unit for indicating sensed information to the user from
the coupler, the indicator unit having a visual indicator for
illustrating sensed information, wherein the indicator unit has a
light for the first jaw, the light illuminating when an attachment
pin is sensed within the first jaw and wherein the indicator unit
has a light for the second jaw or the latch, the light illuminating
when an attachment pin is sensed within the said second jaw or
latch.
50. The coupler of claim 49, wherein the indicator also has a light
for illuminating when an attachment pin is not sensed.
51. The coupler of claim 1, further comprising an actuator for
operating the coupler's latching mechanism, wherein a third sensor
is incorporated into or onto the actuator for sensing one of the
extension state of the actuator, and, when the actuator is a
hydraulic ram that is mounted within the frame of the coupler, the
hydraulic pressure within the ram.
52. The coupler of claim 1, further comprising a sensor of a
work-tool recognition system for identifying information regarding
an attached accessory.
53. The coupler of claim 1, wherein a sensor is provided on the
coupler for detecting, in use, a loading applied to a lifting eye
of the coupler.
54. A coupler for coupling an accessory to an excavator arm of an
excavator, the coupler comprising: a first jaw that points in a
generally longitudinal direction relative to the frame of the
coupler, the first jaw being for receiving a first attachment pin
of an accessory; a second jaw longitudinally spaced from the first
jaw with respect to the frame of the coupler, for receiving a
second attachment pin of the accessory, the second jaw including a
latch for locking the second attachment pin into the second jaw of
the coupler; and an actuator for operating the coupler's latching
mechanism; and a sensor provided on the coupler, the sensor being
incorporated either into or onto the actuator for detecting status
information of the actuator, or into or onto a lifting eye of the
coupler for detecting loading applied to a lifting eye of the
coupler.
55. A method of notifying to a driver of an excavator the accessory
engagement status of a coupler attached to an end of the
excavator's arm, wherein the coupler is in accordance with claim 1,
comprising sensing an accessory engagement status of the coupler
using the or each sensor and transmitting or sending that sensed
information to a notification unit near the driver.
56. The method of claim 55, wherein one of the sensor system and
the notification system is linked to the hydraulic control system
of the excavator, whereby if an unsafe accessory engagement status
is sensed, the hydraulic system's output is restricted.
57. The method of claim 55, wherein one of the sensor system and
the notification system is linked to the engine management system
of the excavator, whereby if an unsafe accessory engagement status
is sensed, the engine's power is restricted.
58. The method of claim 55, wherein the coupler transmits
information regarding the accessories and/or excavators to which it
is, and/or has been, attached, for receipt by a receiver in or on
an excavator.
59. A method of notifying to a driver of an excavator the accessory
status of a coupler attached to an end of the excavator's arm,
wherein the coupler is in accordance with claim 54, comprising
sensing an accessory status of the coupler using the sensor and
transmitting or sending that sensed information to a notification
unit near the driver.
60. The method of claim 59, wherein one of the sensor system and
the notification system is linked to the hydraulic control system
of the excavator, whereby if an unsafe accessory status is sensed,
the hydraulic system's output is restricted.
Description
[0001] The present invention relates to a coupler for remotely
attaching accessories, such as buckets, to an excavator arm of an
excavator, e.g. from the cab of the excavator, the coupler being
provided with coupling status sensors.
[0002] Couplers for remotely attaching accessories to an excavator
arm of an excavator are well known per se. However, few such
couplers have sensors built into them. Nevertheless, such couplers,
with sensors, are known, and one such coupler is disclosed in
EP1318242, to Geith Patents Limited. That document discloses a
coupler with a sensor for detecting when the coupler has been moved
into a crowd position (i.e. a fully curled position), and control
electronics for permitting the coupler to commence a decoupling
procedure only while the coupler is in that crowd position. That
crowd position is deemed to be a safe position for decoupling
procedures since in that crowd position, the coupler is arranged
such that its front jaw is pointing at least partially upwards,
whereby an accessory to be attached, or detached, which coupler
will already have an attachment pin located within that front jaw,
cannot fall off the coupler even if all other retaining mechanisms
for that accessory are released.
[0003] Another prior art coupling system is disclosed in
US2004/0244575. It likewise looks for the occurrence of the crowd
position. However, it does so by monitoring for a full extension of
one of the excavator arm's hydraulic rams, i.e. the ram that causes
the crowd position to occur.
[0004] Despite the prior art teachings, however, there is still a
possibility that a user will misuse couplers by using them, for
example, for transporting accessories without a proper coupling of
the accessory onto the coupler, e.g. by just hooking an attachment
pin of an accessory onto that front jaw without completing the
coupling procedure (i.e. by engaging/locking the second attachment
pin of the accessory into the rear jaw of the coupler). Such
improper uses can give rise to dangerous situations since the
attachment can often be shaken out of that front jaw, or it can be
accidentally released from that front jaw if the arm and coupler
are uncurled. This danger is particularly prevalent given that it
is not always immediately apparent whether the accessory is
properly attached to the coupler, e.g. upon a user returning to the
excavator after a lunch break, and since the accessories are often
extremely heavy and large, especially in the mining industries,
whereby an accidental decoupling can present a serious risk of
serious injury to the user and bystanders alike.
[0005] The present invention, therefore, seeks to provide a
mechanism for preventing or dissuading a user from engaging in such
improper uses of couplers.
[0006] According to the present there is provided a coupler
comprising a first jaw that points in a generally longitudinal
direction relative to the frame of the coupler, the jaw being for
receiving a first attachment pin of an accessory, wherein a sensor
is provided for that jaw for detecting the presence of an
attachment pin therein.
[0007] The sensor may be adapted to output a signal to signify the
presence of an attachment pin in the jaw. Alternatively, or in
addition, the sensor may be adapted to output a signal to signify
no detected presence of an attachment pin in the jaw.
[0008] The sensor's signal may be transmitted or sent to a
receiving unit, or to a transmitter, for allowing an indication of
the sensed information to be passed to a user. The transmission may
be along a wire, or it may be wireless, for example a radio
transmission. Such wireless transmitting technologies are well
known in the automobile arts. See, for example, keyless entry
systems, tire pressure monitoring systems, and Bluetooth.RTM.
systems for linking mobile telephones to the vehicle's audio
system.
[0009] The user to whom the sensed information is passed,
preferably sees, hears or feels the indication while he is within a
cab of the excavator to which the coupler is attached. That
receiving unit, or a display/indicator mechanism therefor, may
therefore be integrated into the excavator's dashboard. In another
arrangement, the receiving unit, or a display/indicator mechanism
therefor, may be provided as one or more separate components for
fitting onto or into the excavator, again preferably within the cab
of the excavator. The user, while in the cab, can thus be notified
whether an attachment pin is positioned in that first jaw.
[0010] The sensor may be a strain sensor. This could detect the
presence of an attachment pin within the jaw since accessories, and
excavator arms, are generally very heavy. Therefore, even if the
accessory is resting on the ground, the weight of the accessory, or
the weight of the arm, will usually cause a force to be applied to
the jaw by the accessory's attachment pin. That force will stress
the jaw, thereby creating a detectable strain, perhaps in the
throat of the jaw. Therefore, a strain gauge located at or in the
jaw would be able to detect the presence of an attachment pin
within that jaw.
[0011] Other possible sensors might be contact sensors, e.g. PTM
(push-to-make) switches. Yet further possible sensors might be
magnetic sensors--the attachment pin is usually made of steel. The
skilled person will appreciate, however, that numerous different
sensors, or combinations thereof, could be used for detecting the
presence, or not, of an attachment pin within the jaw. The
advantage of a strain sensor, however, is that it will detect the
presence of the attachment pin irrespective of where the pin bears
against the jaw, since the stain will be distributed around the
throat of the jaw.
[0012] The coupler may also comprise a second jaw, longitudinally
spaced from the first jaw with respect to the frame of the coupler.
That second jaw is preferably facing substantially downwards, i.e.
approximately perpendicularly to the first jaw, and away from the
end of the arm of the excavator that is attached to the coupler.
The second jaw is for receiving a second attachment pin of the
accessory, and it is preferably associated with a pivoting or
sliding latch for locking that second attachment pin within that
second jaw. In some known couplers, however, just the pivoting or
sliding latch is provided--the jaw is omitted.
[0013] Preferably a sensor is associated with that second jaw, or
the pivoting or sliding latch. That second sensor can be instead of
the first sensor, or in addition to the first sensor.
[0014] The second sensor is preferably also for detecting the
presence of, or the absence of, an attachment pin. However, that
detection is for the second jaw, or for the pivoting or sliding
latch, instead of the first jaw.
[0015] Preferably the second sensor is mounted directly onto or
into to the pivoting or sliding latch, or onto or into that second
jaw's alternative locking mechanism. Locating it into or onto a
pivoting or sliding latch, however, is most preferred since most
commercial couplers feature either a pivoting hook or a sliding
plate for providing such a locking function.
[0016] Preferably the second sensor is a strain gauge. However, any
suitable sensor could be provided, as for the first sensor.
[0017] The second sensor may have similar or identical features to
the first sensor. However, upon transmitting the signals to the
receiving unit, the source of the signals, i.e. with respect to
which sensor they came from, is preferably discernable by the
receiving unit. For transmissions made wirelessly, this can easily
be achieved by using ID codes in the transmitted signals, or even
by using a single transmitter for transmitting both sensors'
signals in receiver-recognisable manner. Such coding technologies
are well known in radio transmitting arts, such as tyre pressure
monitors.
[0018] It should also be observed that sensors and transmitters can
readily be made suitably tough to cope with the environments to
which couplers are exposed by using designs developed for tyre
pressure monitors. After all, such prior art systems are designed
to cope with high speed tyre environments, and the associated
forces encountered therein. Therefore, a further discussion of the
specific design of suitable sensors and transmitters is not
required herein.
[0019] The indicator unit for indicating the sensed information to
the user is preferably in the cab of the excavator. It preferably
has visual indicators. They preferably separately provide an
indication of the coupling status of the first and second jaws,
i.e. whether there is an attachment pin in the respective jaw. In a
simple embodiment, that may be by means of a light for each jaw.
For example, the light for a jaw could be illuminated when an
attachment pin is located within the relevant jaw, or perhaps when
an attachment pin is not located within the relevant jaw. The user
can therefore instantly determine the accessory engagement status
of the coupler.
[0020] In a preferred embodiment, a green light signifies safety
and a red light signifies danger. Therefore, when both jaws are
correctly engaged against a pin, i.e. the front jaw's sensor senses
the presence of a pin, and the rear latch's sensor also senses the
presence of a pin, two green lights can show on the indicator unit.
This indicates a safe mounting of an accessory on the coupler.
However, if only one pin is sensed, a red light could be
illuminated. That would indicate an unsafe mounting condition.
[0021] An alternative arrangement would have a green light show
when the first jaw is correctly engaging a pin, but with a red
light showing for the second jaw until that second jaw is correctly
engaged with the second pin.
[0022] It is possible also to illuminate green lights when no pin
is sensed, since the coupler would then not be attached to an
accessory, whereby it is safe--there is no risk of an accessory
falling off of the coupler. This is useful since couplers typically
also feature a lifting eye, which can be used for lifting items
with chains or ropes.
[0023] A third sensor, and a third light, might also be
incorporated into the coupler at the hydraulic ram. It can sense
the location of the latch mechanisms by determination of the state
of the ram. That status information can also be transmitted to the
receiver for analysis and evaluation. Likewise, a sensor could be
provided for sensing the orientation of the coupler.
[0024] These and other sensors may be used together with other
sensors to build a virtual picture of the condition of the coupler
for analysis by a control system, which control system can provide
suitable warnings to the user if dangerous conditions are
encountered, or simply feedback to the user to assist with coupling
or decoupling procedures since those procedures usually require a
number of steps to be undertaken, and the control system could
signal to the user when a particular step has been completed, e.g.
retraction/advancement of the ram, or inversion of the coupler. See
WO2008/029112 or GB0808113.5 for disclosures of various coupling
and decoupling procedures.
[0025] The sensing systems, or the receiver, can be linked to the
hydraulic control system of the excavator. With such an
arrangement, if an unsafe condition is sensed, the hydraulic
system's output can be restricted. For example, the detection of
just one attachment pin, e.g. in the first (front) jaw, could cause
not just the illumination of a red light on the display unit for
the second jaw's sensor, but also a restriction in the operability
of the excavator arm. For example, lifting or swinging motions
might be restricted, prevented or slowed. One such restriction
might be the provision of a half throttle setting for the
hydraulics, or rotation limits for swinging elements. These
restrictions could prevent unsafe digging activities from being
carried out, but without preventing dangerous situations from being
recoverable using the hydraulics. A user would thus be prevented or
discouraged for undertaking unsafe working practices with the
excavator and coupler.
[0026] In addition to controlling or limiting the hydraulics
usability, the excavator's manoeuvrability or engine power might
also be linked to the sensing system, or to the receiver, whereby
they might also be restricted if a dangerous or unsafe accessory
condition is sensed. This could be useful since it could
additionally prevent movements of the excavator around a worksite
while an accessory is incorrectly mounted onto the coupler. That
would further prevent or discourage improper operator practices,
thereby further reducing the possibility for a user to expose
himself, or others, to dangerous situations of his own making.
[0027] In one embodiment, an additional or separate sensor forms
part of a work-tool recognition system. The work-tools for such a
system are additionally provided with a readable or transmittable
indicator. That indicator might be optically, magnetically,
inductively or capacitively readable, or it might be a transmitted
signal that can be received and read by the coupler's sensor. Such
transmissions can be via wires or they can be wireless.
[0028] In preferred embodiments, the indicator is either a barcode
(and the sensor on the coupler is a barcode reader) or an RF
(radio-frequency) transmitted signal, which signal might be emitted
in response to an interrogation by a sensor on the coupler, or in
response to a circuit being completed by the coupling process. Such
RF signals would preferably be in the form of a transmitted ID
code, or in the form of a more informative signal containing an ID
code and some other usable information.
[0029] The other usable information is preferably indicative or one
or more of the following parameters: tool type (i.e. bucket,
grabber or drill), tool weight or tool capacity (to allow the
operator, or the excavator itself, to know/decide whether the
excavator is man enough to handle to tool), tool serial number (to
allow the specific tool to be tracked), tool age or duty cycle (to
allow the operator, or the excavator itself, to know/decide whether
the tool is still safe to use, or whether it is likely to suffer a
fatigue failure), and tool configuration (e.g. attachment pin size
or attachment pin spacing, to allow the coupler to know whether the
tool is mountable onto the coupler).
[0030] Likewise, a sensor might be provided on the coupler to read
information from the excavator or the excavator arm. For that
purpose, the excavator and/or the excavator arm can be additionally
provided with a readable indicator. Similar readable indicators as
those that are disclosed above for the accessory could be suitable
also for the excavator and/or the excavator arm.
[0031] Instead of mounting the additional sensors onto or into the
coupler, the additional sensors might be mounted onto the
accessory, or onto the excavator arm/excavator, with the coupler
then having the readable/transmittable indicator(s).
[0032] With these additional sensors and indicators, couplers,
excavators and accessories can be recognised, and thus known
limitations of the accessories, couplers or excavators can be
accommodated by the control electronics of the excavator. For
example, if an accessory such as a drill is attached, the excavator
might want to be limited as to how much lateral force gets applied
to the accessory during drilling operations. With such a tool
recognition system, such limitations can be imposed automatically
by the excavator's control electronics, thereby reducing the
likelihood of, or preventing, operator error causing severe damage
to accessories.
[0033] Preferably the sensed information is sent to the excavator's
receiver for processing by the excavator's OEM ECU. That ECU
preferably has a memory for storing use information for particular
tools or accessories.
[0034] Likewise, preferably an ECU is located in the coupler, also
with a memory, whereby information as to which accessories and
which excavators have been attached to the coupler can be stored,
or even to allow the coupler to have its own intelligence for
enabling it to refuse to couple to accessories that fall outside
the achievable capacities of that coupler, i.e. accessories that
are too heavy.
[0035] Additional sensors might also be provided in the coupler to
sense the loading applied to the coupler during use of an
accessory. Those sensors could be the above-mentioned strain
gauges. These could be used to sense overload conditions in the
coupler during such use. Those overload conditions might be
overloading of the coupler, e.g. the jaws or the latching hook, or
of the lifting eye, or they might be overloading of the accessory,
e.g. where the coupler has recognised the accessory to have a
maximum loading capacity, or a maximum digging/drilling force
capacity. The coupler could then emit a warning to the operator to
inform the operator of that overload condition, or it may signal
that condition instead to the excavator's receiver/ECU, whereby the
excavator can impose operational restrictions automatically.
[0036] Sensors might also be provided in the coupler, or in the
accessory, or in the excavator, to provide
coupler/accessory/excavator tracking capacity, e.g. by the use of
GPS sensors, and memorising the identity and location of each
accessory/excavator/coupler coupling combination. Then, that stored
information might be used to locate specific products in the
future, or for tracking the movement of specific products. This
allows the movements of a company's fleet and assets to be tracked.
Further it can assist in the tracking down of stolen accessories or
couplers.
[0037] A specific embodiment of the present invention will now be
described, by way of example only, with reference to the
accompanying drawings, in which:
[0038] FIG. 1 schematically illustrates an excavator fitted with a
coupler in accordance with the present invention; and
[0039] FIG. 2 schematically illustrates details of that
coupler.
[0040] Referring first to FIG. 1, there is shown an excavator 10
comprising an excavator arm 12, a cab 14, an engine area 16, tracks
18 and hydraulic rams 20 for controlling the operation of the
excavator arm 12.
[0041] A coupler 24 in accordance with the present invention is
attached to the free end 22 of the excavator arm 12. For that
purpose, two attachment points 26 (see FIG. 2) are provided on the
coupler 24, and two attachment pins (not shown) extend through
those attachment points 26 for making the attachment. This type of
attachment system is conventional in the art.
[0042] An accessory 28 is then attached to that coupler 24. As a
result, the excavator 10, via its excavator arm 12 and hydraulic
rams 20, can be used to perform operations with the accessory
28.
[0043] In this embodiment, the accessory 28 is a bucket, so normal
operations will be digging.
[0044] Referring now to FIG. 2, additional details of the coupler
24 will be described.
[0045] The two arm attachment points 26 are positioned in a top
portion of the coupler 24. The bottom portion of the coupler 24
then has the accessory attachment components. They include a front
jaw 30 and a rear jaw 32, each of which will engage attachment
pins, but this time on the accessory 28. For that purpose, the
front jaw 30 points substantially longitudinally relative to the
main axis of the coupler 24 (i.e. towards the cab in FIG. 1),
whereas the rear jaw 32 points downwardly, i.e. towards the main
body of the accessory. As such, the front or first jaw 30 can pick
up the accessory by hooking onto a first attachment pin of the
accessory, and the second attachment pin of the accessory can then
be swung into the open mouth of the rear or second jaw 32. Then,
via a pivoting latching hook 34, the rear jaw 32 can be closed for
securing the second attachment pin as well. The accessory 28 is
thus fully coupled onto the coupler 24.
[0046] The pivoting latching hook 34 is driven into its
pin-engaging position by the coupler's own hydraulic ram 36, i.e. a
hydraulic ram 36 that is contained within the coupler 24.
[0047] The above features of the coupler are also all conventional.
They are also interchangeable with alternative mechanisms known in
the art. For example, additional securement mechanisms can be
incorporated into the coupler, such as in GB2330570 or
WO2008/029112. Further, instead of a pivoting latching hook 34, a
sliding latching plate might be preferred. Likewise, instead of the
hydraulic ram 36, a screwthread drive, or merely a lever-releasable
spring could be provided for moving the pivoting or sliding latch
34.
[0048] The rear of the coupler 24 is also provided with a lifting
eye 38. This allows items to be safely hoisted using ropes or
chains.
[0049] All of the above elements of the illustrated coupler are
known or conventional in the art. Therefore, their respective uses
and applications should not need to be discussed further. It should
be appreciated, however, that these couplers can be provided in a
wide range of sizes, i.e. in sized that are suitable for use with a
range of excavators.
[0050] The inventive features of the present invention are the
additional elements disclosed in the following passages:
[0051] The coupler is adapted to include sensing and communication
technologies. They serve to provide information to the excavator
driver in the cab via a display, although the information might be
presented elsewhere if preferred. The presentation of the
information, however, allows the status of the coupler, or of any
coupling/decoupling procedure, i.e. "work tool attachment status"
to be communicated to the driver. Likewise it can be reported to a
control system in the excavator for providing automated interlocks,
which once implemented can prevent certain undesirable or unsafe
actions from being carried out by the operator until an appropriate
verification of the coupler's condition or status is achieved by
the system.
[0052] Manual overrides might be provided. However, it would be
preferable if they could be avoided to ensure that no improper uses
can occur.
[0053] The provision of such interlocks, or "limp modes", such as
reduces throttles, or restricted movement ranges, or reduces
hydraulic power, will greatly improve workplace safety by
preventing or averting dangerous operations of the excavator, or by
minimising or eliminating misuse opportunities.
[0054] The sensing and communication technologies, in the
illustrated embodiment, comprise a selection of sensors, any one of
which can provide a useful and advantageous function in its own
right. The first sensor 40 is a sensor provided for the first jaw
30. It is for detecting whether an attachment pin is located within
that front jaw 30. This could be a proximity sensor, a touch or
push actuated sensor or a parameter measuring sensor--e.g. a stress
or strain measurement or sensing device. It is shown to be located
at the throat of the front jaw 30. This is where an attachment pin
will typically sit, whereby it will usually be the optimum
position. However, it is possible that more than one sensor, in
different positions on that jaw 30, will be necessary to ensure
that any attachment pin within that jaw can be sensed. This would
be of particular value in front jaws having dual-radiused throats
(see, for example, Registered Community Design No. 000452271.0003).
That is because a second sensor in the wall of the larger radiused
portion of the jaw would allow a large diameter attachment pin,
i.e. one which would not fit into the back of the throat of the jaw
30, also to be sensed.
[0055] The optional second, or further sensor 42 is provided for
the second or rear jaw 32. In this embodiment it is located in the
pivoting latching hook 34. This second sensor 42 can be identical
to the first sensor, in that it is also for detecting the presence
of an attachment pin in its associated jaw--the rear jaw 32. By
positioning it in the hook, it will only detect the attachment pin
upon the engagement of that attachment pin by the pivoting latching
hook 34. This prevents a false detection of an unsecured attachment
pin. However, if a separate sensor detects the location of the
hook, that same level of detection could be achieved with the
second sensor being located in the throat of the second jaw.
[0056] Again more than one sensor might be provided since different
attachment pins might engage against different parts of the jaw, or
against different parts of the hook, especially where the two
attachment pins are from an accessory that has a different
centre-to-centre pin spacing.
[0057] The coupler of this exemplary embodiment also has a third
sensor 44, which sensor is located within or upon the hydraulic ram
36. It might likewise be located within the ram's hydraulic
supply-line. This sensor serves to detect either or both hydraulic
pressure or hydraulic ram extension status. Such data can serve to
allow an even better picture of the coupler's status to be
determined. For example, it allows the position of the pivoting
latching hook 34 to be checked, or it can identify a hydraulic
fluid leak.
[0058] Other sensors, not shown, can include orientation sensors,
for determining whether the coupler has been inverted, or perhaps
to what degree it has been inverted. These can be helpful in
ensuring that a decoupling procedure is not commenced while the
accessory 28 is in an unsafe position relative to the coupler 24,
i.e. such that it could fall from the coupler if the rear jaw was
opened.
[0059] Yet further sensors might be provided to identify
information from the accessory themselves, for example from a
transponder in the accessory, for detecting accessory type or
accessory capacities, which information can also be of potential
use to a central control unit. That information could be stored in
the transponder within the accessory.
[0060] In the illustrated embodiment, the various sensor components
are shown to be integrated into the components of the couplers. As
such, the coupler is bespoke fabricated with the sensors built
therein. It should be appreciated, however, that sensors will be
incorporatable into existing couplers, or known coupler designs, by
way of retrofits. Likewise, the associated control electronics,
such as those that will be found in the coupler's central control
unit 46 in FIG. 2, can be either pre-built onto or into the
coupler's frame as an integrated part of the coupler 24, or they
might be an aftermarket addition.
[0061] In the illustrated embodiment, the first two sensors 40, 42
are adapted to sense the presence of an attachment pin in their
respective jaw or hook, and the third sensor 44 serves to detect
the hydraulic pressure within the hydraulic ram 36. That sensed
data is then either intermittently or continuously sent to the
associated control electronics for analysis, or for transmission to
further control electronics such as a receiver 48 in the cab. The
resulting status information about the coupler is then displayed to
the user, or else (or in addition) the data is acted upon by the
excavator's own control electronics in the appropriate manner, such
as by allowing excavator operations, or by implementing appropriate
"limp modes" for the detected coupler status. Numerous possible
actions in that regard are possible. For example, the display could
have lights signifying good or bad conditions for each sensor, such
as a green light for a good sensed condition and red for a bad
sensed condition, with the display showing all green lights when an
accessory is fully coupled to the coupler, and at least one red
light when an accessory is detected to be incorrectly coupled to
the coupler. A limp mode for the excavator would be likely to be
implemented whenever such a red light is indicated.
[0062] As indicated above, it will be appreciated that the jaws'
sensors should be designed to detect a variety of different
attachment pins, such as pins with different radiuses, or different
centre-to-centre pin spacings. This is because an excavatore will
frequently be used with a variety of different accessories, and not
all necessarily from the same manufacturer--such different
accessories often have different pin spacings, or different pin
radiuses. Further, attachment pins can become worn, whereby the pin
spacing between the two pins of an accessory can vary over
time.
[0063] It will also be appreciated that the sensors should be
capable of handling, or at least be protected from, the various
harsh environmental conditions that a coupler is likely to be
exposed to, such as temperature extremes, regular exposures to
abrasive materials such as stones, rocks and mud, rough handling,
and also immersion in sea water, fresh water or mud. Such toughened
sensor technologies are already available, such as from
neighbouring fields like tyre pressure monitors.
[0064] In one preferred embodiment, the pin sensors 40, 42 in the
front and rear jaws 30, 32 are stress or strain sensing sensors.
The can detect the presence of an attachment pin within a jaw since
accessories are generally very heavy, whereby the jaws will be
exposed to significant loading under the weight of an attached
accessory. Such stress or strain sensors could therefor detect the
presence of an attachment pin by the detection of such forces.
Further, since those forces will be experienced around the jaw,
rather than just at a specific location on the jaw (i.e. the
contact location between the pin and the jaw), the location of the
sensor is less significant in determining the ability of the sensor
to achieve its function.
[0065] Instead of stress or stain sensors for the first and second
sensors, however, proximity sensors might be provided. They could
detect the proximity of an attachment pin within the jaws.
[0066] In the illustrated embodiment, the three illustrated sensors
40, 42, 44 are connected to the central control unit 46 either with
wires or wirelessly--the sensors can be wired to the central
control unit 46, or they can have their own radio transmitters
built into them. That central control unit 46 therefore receives
the sensed signals from those sensors and can compile that
information ready for transmission to the receiver 48 in the cab 14
as intermittent databursts. That receiver 48 is shown to be within
the cab of the excavator 10, but it could be elsewhere, with it
instead being connected to a display.
[0067] The receiver therefore receives the transmissions through a
wireless transmission such that the receiver can process the sensor
data and cause the display or the excavator's control system to act
appropriately. The present invention therefore allows the coupler
to transmit its own coupler status information reliably to the
driver in the cab of the excavator.
[0068] It will be appreciated that transmission and receiver
technologies suitable for such transmissions are well developed in
various arts, including tyre pressure monitors. Further, any
necessary coding or pairing systems for such transmission/receiver
pairs are well developed in those arts. A further discussion of
them here is therefore not necessary.
[0069] In place of a wireless transmission to the cab, a wired
system could be used to transfer the data. This has the advantage
of no local power being needed at the coupler--the sensors could be
powered by the excavator's own power system. However, wireless
transmissions are preferred since they are easier to incorporate
into existing excavators and couplers--they need minimal setting
up, and can readily allow couplers to be removed from the excavator
for servicing.
[0070] To power the wireless transmitters, preferably an onboard
power system is provided on the coupler. That could simply be a
battery within the central control unit 46. However, a generator
might be alternatively be provided on the coupler for generating
the required power through kinetic energy recovery--couplers
experience a great deal of shaking when they are in use.
[0071] Where a battery is provided, a further sensor might be
provided to monitor battery power. The sensor system could
therefore also provide a low battery power signal in its
transmission when a low battery status is detected to alert the
operator of that fact.
[0072] The display or man-machine interface (MMI) in the cab (for
indicating the sensor information, or coupler status information)
can be programmed to provide its information in a number of ways,
or just such that it interacts with the excavator's controls in a
number of different ways.
[0073] In one system, the signals are translated into visual
indicia such as lights or coupler status representations, such that
a display can guide the operator through an accessory coupling or
decoupling procedure by providing graphical indications when
certain individual steps of that coupling or decoupling process
have been achieved. This can be helpful since that information is
not always possible to see from within the cab (e.g. the position
of the pivoting latching hook).
[0074] Alternatively, or additionally, the interface can provide
excavator functionality lockouts (i.e. "limp modes") in response to
certain detected situations, such as an incomplete coupling of an
accessory to the coupler (e.g. just in the front jaw). In this
regard, specific excavator or excavator arm movements can be
restricted or disabled until the coupling procedure has been
completed. Alternatively, engine or hydraulic power may be reduced,
whereby digging or manoeuvring is made more difficult. That should
dissuade the driver from commencing or continuing an improper use
of the coupler/excavator.
[0075] One preferred feature, however, is that when no attachment
pin is detected, full functionality for the excavator is allowed.
That is because the coupler is usually fitted with a lifting eye
38, which is often used for lifting items on a chain or rope. To
disable that function would be a significant inconvenience.
Further, without such freedom to move in an uncoupled condition,
manoeuvring the coupler and excavator to align the front jaw with a
first attachment pin of a new accessory for coupling thereto would
also be is made more difficult, which would also obviously be
undesirable.
[0076] With regard to the limp modes, one such mode could be a low
power mode in which the throttle is limited to a maximum of a
quarter throttle. That could be for either the excavator's engine
or just for the hydraulic pump.
[0077] It will also be observed that the sensor 44 for the
hydraulic ram 36 could provide an additional overriding control,
whereby in the event of the detection of a failure in that
hydraulic system, that alone would be enough to cause a limp mode
to be effected.
Certain Additionally Optional Features are as Follows:
[0078] To enable wireless transmissions to be recognised by the
receiver 48, transmissions can be coded with unique identity
information that can be transmitted for identifying the
coupler/sensors from which the transmission had originated.
[0079] Transmissions could perhaps also include details of the
accessory that is connected to the coupler, e.g. accessory type
information. That would be detectable by a sensor on the coupler
that can read information from a transceiver on the accessory.
[0080] Duty cycle information, such as hours used or cycle
completed, might be monitored by the control system, either at the
coupler or at the receiver. That information could be logged at the
coupler and transmitted to the receiver, or logged at the receiver,
whereby accessories having a finite duty life can be tracked and
repaired or replaced as and when necessary.
[0081] Likewise, other sensed information can be logged or
transmitted, such as work-tool recognition information, excavator
recognition information, pairing information, tool suitability
information (e.g. tool capacities, types, or sizes), tool or
coupler use information (e.g. current loading information), and
tracking information (e.g. GPS positioning information) for
allowing fleet or asset tracking to be automatically carried out,
or for it to be discernable at a later date from stored
information.
[0082] From the above disclosure, therefore, the present invention
provides a coupler for coupling an accessory to an excavator arm of
an excavator, the coupler comprising a first jaw that points in a
generally longitudinal direction relative to the frame of the
coupler, the jaw being for receiving a first attachment pin of an
accessory and having a first sensor for detecting the presence of
an attachment pin therein, the coupler further having a second jaw,
or a latch, longitudinally spaced from the first jaw, and being for
receiving a second attachment pin of the accessory, and having a
second sensor for detecting the presence of an attachment pin
therein. Other features may then be added to it as described
above.
[0083] It will also be appreciated that this disclosure also
provides for further embodiments in which the additional sensors
replace one or the other, or both, of the first two sensors. In the
most preferred embodiments, however, the sensors of the coupler, or
a central transmitter, are adapted to transmit or send signals to a
receiver for notifying the driver or operator regarding the
coupling status of the coupler, or the loading status of the
coupler, so as to keep the driver informed as to that status, or in
more advanced embodiments, to allow the excavator to apply
operational limitations to the control electronics/hydraulics when
problems are identified.
[0084] Although the present invention has been described above
purely by way of an illustrated example, and by way of possible
alternative or additional features, it will be appreciated that
modifications in detail may be made to the invention within the
scope of the claims as appended hereto.
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