U.S. patent application number 15/136701 was filed with the patent office on 2016-08-18 for couplers.
This patent application is currently assigned to Doherty Engineered Attachments Limited. The applicant listed for this patent is Jeremy Glen DOHERTY, Paul James DOHERTY. Invention is credited to Jeremy Glen DOHERTY, Paul James DOHERTY.
Application Number | 20160237656 15/136701 |
Document ID | / |
Family ID | 52993219 |
Filed Date | 2016-08-18 |
United States Patent
Application |
20160237656 |
Kind Code |
A1 |
DOHERTY; Jeremy Glen ; et
al. |
August 18, 2016 |
COUPLERS
Abstract
A coupler for attaching an implement to a machine, the coupler
including a body portion, a first jaw configured to engage a first
attachment portion associated with the implement; a moveable jaw
configured to engage a second attachment portion associated with
the implement; and a first sensor located on the body portion
configured to detect the presence of the implement adjacent to the
body portion and to indicate one of a safe position in which the
implement is securely held by the coupler and an unsafe position in
which the implement is not securely held by the coupler.
Inventors: |
DOHERTY; Jeremy Glen;
(Papamoa, NZ) ; DOHERTY; Paul James; (Papamoa,
NZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DOHERTY; Jeremy Glen
DOHERTY; Paul James |
Papamoa
Papamoa |
|
NZ
NZ |
|
|
Assignee: |
Doherty Engineered Attachments
Limited
Mount Maunganui
NZ
|
Family ID: |
52993219 |
Appl. No.: |
15/136701 |
Filed: |
April 22, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/NZ2014/000221 |
Oct 22, 2014 |
|
|
|
15136701 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02F 3/3618 20130101;
E02F 3/3663 20130101; E02F 3/3622 20130101; E02F 9/264
20130101 |
International
Class: |
E02F 9/26 20060101
E02F009/26; E02F 3/36 20060101 E02F003/36 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 22, 2013 |
NZ |
NZ616928 |
Claims
1. A coupler for attaching an implement to a machine, wherein the
implement includes a first attachment portion and a second
attachment portion, the coupler including: a body portion; a first
jaw configured to engage the first attachment portion; a moveable
jaw; an actuator configured to move the moveable jaw with respect
to the body portion between an engaging position in which it
engages a second attachment portion associated with the implement
and a disengaging position in which it does not engage the second
attachment portion; and a first sensor located on the body portion
configured to detect the presence of the implement adjacent to the
body portion; a sensor configured to determine if the first
attachment portion is engaged by the first jaw; an indicator unit
configured to provide an indication to a user that the first sensor
detects the presence of the implement adjacent to the body
portion.
2. The coupler as claimed in claim 1, wherein the first jaw is a
fixed jaw.
3. The coupler as claimed in claim 2, wherein the fixed jaw is
formed integrally with the body portion.
4. The coupler as claimed in claim 1, wherein the coupler is
configured to attach to an articulated arm.
5. The coupler as claimed in claim 1, wherein the first jaw is
configured to engage with a first attachment portion in the form of
a pin.
6. The coupler as claimed in claim 5, wherein the first jaw is
substantially `U` shaped.
7. The coupler as claimed in claim 6, wherein the moveable jaw is
slidably coupled to the body portion so that the moveable jaw moves
in a sliding motion between the engaging position and the
non-engaging position.
8. The coupler as claimed in claim 1, including a sensor configured
to detect whether the movable jaw is in the engaging position.
9. The coupler as claimed in claim 1, including a sensor configured
to detect whether the movable jaw is in the non-engaging
position.
10. The coupler as claimed in claim 1, wherein the movable jaw
includes a substantially `U` shaped engaging portion configured to
receive the second attachment portion.
11. The coupler as claimed in claim 1, wherein the first sensor is
located proximate the moveable jaw.
12. The coupler as claimed in claim 11, wherein the first sensor is
positioned so as to abut a portion of an implement when, in use,
the implement is positioned such that the second attachment portion
is engageable by the moveable jaw.
13. The coupler as claimed in claim 12, wherein the first sensor is
positioned so as to abut the second attachment portion of the
implement, or part thereof.
14. The coupler as claimed in claim 1, including a third sensor
configured to detect the presence of the first attachment portion
within the first jaw.
15. A system for coupling an implement to a machine, the system
including: a coupler having a body portion including a fixed jaw
attached to the body portion and configured to engage a first
attachment portion associated with the implement; a moveable jaw
moveably attached to the body portion and configured to engage a
second attachment portion associated with the implement; an
attachment between the coupler and the machine, the attachment
configured to impart a rotation to the coupler about a pivot axis
parallel to a width of the fixed jaw, wherein, in use, rotation of
the coupler about the pivot axis allows the body portion of the
coupler to be rotated relative to the implement first attachment
portion, and a first sensor located on the body portion configured
to detect the presence of the implement adjacent to the body
portion when the moveable jaw is not engaged with the implement and
at a location spaced apart from the fixed jaw.
16. The system as claimed in claim 15, including a second sensor
configured to detect whether the movable jaw is in an engaging
position.
17. The system as claimed in claim 15, including a second sensor
configured to detect whether the movable jaw is in a non-engaging
position.
18. The system as claimed in claim 15, including a third sensor
configured to detect the presence of the first attachment portion
within the fixed jaw.
19. The system as claimed in claim 15, including an indicator unit
that indicates a sensor status.
20. The system as claimed in claim 19, wherein the indicator unit
is located remotely to the coupler.
21. The system as claimed in claim 15, integrated with, or coupled
to, a control system associated with the machine to which the
coupler is attached.
22. The system as claimed in claim 21, wherein the control system
associated with the machine to which the coupler is attached limits
one or more functions of the machine if in use, the second
attachment portion of the implement is detected as not being
adjacent to the body portion of the coupler.
23. A method of coupling an implement to a machine using a coupler,
the coupler having a body portion including a fixed jaw attached to
the body portion and configured to engage a first attachment
portion associated with the implement; a moveable jaw moveably
attached to the body portion and configured to engage a second
attachment portion associated with the implement, and a first
sensor located on the body portion and configured to detect when
the second attachment portion of the implement is adjacent to the
body portion when the moveable jaw is not engaged with the
implement and therefore in a position in which it can be engaged by
the moveable jaw, the method including the steps of: a) engaging
the implement first attachment portion with the fixed jaw; b)
rotating the coupler about a pivot axis parallel to a width of the
fixed jaw so as to rotate the body portion towards the implement;
c) detecting, by way of the first sensor, whether the second
attachment portion of the implement is in a position in which it
can be engaged by the moveable jaw; d) outputting a signal
indicative of whether the second attachment portion is in a
position in which it can be engaged by the moveable jaw.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of parent International
Patent Application No. PCT/NZ2014/000221, filed on Oct. 22, 2014.
The entire disclosure of the prior application is hereby
incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to improvements in and
relating to couplers, in particular to couplers for attaching an
implement to a machine.
BACKGROUND ART
[0003] Couplers are commonly used for releasably attaching various
implements to a machine. An example of such a machine is an
excavator. The couplers used by excavators commonly include at
least one, or often two jaws. The jaw(s) each engage a pin on an
implement to secure the implement to the coupler. The couplers are
often remotely operable to release and engage an implement. The
main reason for this is for ease of use. However, it may also be
due to the fact that the implement to be attached is often large
and/or heavy and is therefore impossible to move manually, or
alternatively is likely to injure personnel attempting to manually
attach the implement to the machine.
[0004] One problem that exists with remotely operable couplers is
that it is difficult to tell whether the implement is in the
correct position which allows the jaws of the coupler to engage
with the implement pin(s) and thereby secure the implement to the
coupler ready for use. Due to the large size and weight of some
implements this poses a substantial risk to personnel and or
equipment in the event in which the coupler is not correctly
engaged. An unsecured implement may come free of the coupler and
fall, potentially causing substantial damage, injury or death.
[0005] This danger has been mitigated in part by providing sensors
which indicate when an implement is locked into a jaw of the
coupler. This is typically achieved by locating sensors in one or
more of the jaws of a coupler. The sensors indicate positive
engagement of the implement with the jaws. However, such systems
still require the operator to judge whether the implement is in the
correct position to allow it to be correctly engaged with the
coupler. Often a number of attempts must be made before positive
engagement is achieved. This problem is particularly prevalent with
excavators where the coupler is positioned some distance from the
operator of the excavator, and the coupler is often obscured from
direct view by the excavator arm.
[0006] Some couplers include a sensor that determines whether a pin
is secured in a jaw of the coupler. An example of this type of
coupler is described in GB2009/002602.
[0007] However, the type of coupler described in GB2009/002602 can
result in an unsafe situation. This situation arises when the
sensor detects the presence of an implement pin within the moveable
jaw, yet the implement is not properly secured. One example of when
this situation may arise is if the actuator associated with the
moveable jaw is faulty. When the coupler is oriented to a position
in which the faulty actuator is bearing the weight of the
implement, by way of a pin in the movable jaw, the actuator may
move under the weight of the implement from a locked position to a
position in which the implement is not secured. The operator still
sees a locked status from the sensor and, unaware of this
situation, may then operate the unsecured implement in a manner
which risks damage, injury or death.
[0008] Other issues can arise due to wear of the implement pins.
Some couplers that include sensors in one of the jaws may detect a
worn pin as being locked in the jaw(s) of the coupler, yet the pin
maybe worn to a degree whereby the actuator cannot move the jaw
sufficiently far to fully engage the pin. In use, and under load,
it may therefore be possible for the implement to pull free from
the coupler due to insufficient overlap between the pins and the
jaws.
[0009] It would therefore be useful to have a system which alerts
an operator when the coupler and implement to be attached are in
the correct position for coupling.
[0010] All references, including any patents or patent applications
cited in this specification are hereby incorporated by reference.
No admission is made that any reference constitutes prior art. The
discussion of the references states what their authors assert, and
the applicants reserve the right to challenge the accuracy and
pertinence of the cited documents. It will be clearly understood
that, although a number of prior art publications are referred to
herein, this reference does not constitute an admission that any of
these documents form part of the common general knowledge in the
art, in New Zealand or in any other country.
[0011] Throughout this specification, the word "comprise", or
variations thereof such as "comprises" or "comprising", will be
understood to imply the inclusion of a stated element, integer or
step, or group of elements integers or steps, but not the exclusion
of any other element, integer or step, or group of elements,
integers or steps.
[0012] It is an object of the present invention to address the
foregoing problems or at least to provide the public with a useful
choice.
[0013] Further aspects and advantages of the present invention will
become apparent from the ensuing description which is given by way
of example only.
DISCLOSURE OF THE INVENTION
[0014] The present invention relates to a method and apparatus for
engaging an implement with a coupling device and indicating a
secure state to an operator of the coupler without the need for
latching the implement in place. The present invention is
particularly useful in respect of couplers that are used to couple
implements to a back hoe, or excavator. However, the method and
apparatus should not be seen as being limited to use solely with
such machines.
[0015] According to one aspect of the present invention there is
provided a coupler for attaching an implement to a machine, the
coupler including:
[0016] a body portion;
[0017] a first jaw configured to engage a first attachment portion
associated with the implement;
[0018] a moveable jaw configured to engage a second attachment
portion associated with the implement; and
[0019] a first sensor located on the body portion configured to
detect the presence of the implement adjacent to the body
portion.
[0020] In preferred embodiments the first jaw is a fixed jaw.
[0021] Preferably the fixed jaw is attached to or formed integrally
with the body portion. An integral attachment could be one in which
the fixed jaw is formed from the same piece of material as the body
portion, or alternatively the fixed jaw could be attached in a way
in which the fixed jaw and body portion are fixed together,
examples of such attachment may include welding, bolting, riveting
or the like.
[0022] In some preferred embodiments the coupler may be configured
to attach to an articulated arm.
[0023] Preferably the articulated arm is a back hoe.
[0024] In preferred embodiments the fixed jaw is substantially `U`
shaped, the opening of the `U` facing in an outward direction
substantially parallel to the length of the body portion.
[0025] In preferred embodiments the fixed jaw is configured to
engage with a first attachment portion in the form of a pin.
[0026] In preferred embodiments the moveable jaw is moveable
between:
[0027] an engaging position in which it engages the second
engagement portion; and
[0028] a non-engaging position in which it does not engage the
second engagement.
[0029] In a particularly preferred embodiment the moveable jaw is
slidably coupled to the body portion so that the moveable jaw moves
in a sliding motion between the engaged position and the
non-engaging position. However, the moveable jaw may also be
rotatable or pivotal between the engaged position and the
non-engaging position.
[0030] In preferred embodiments the movable jaw includes a
substantially `U` shaped engaging portion configured to engage with
the second attachment portion.
[0031] Preferably, the opening of the `U` faces in an opposite
direction to the fixed jaw when in the engaging position.
[0032] The coupler of the present application is for use with an
implement that includes an attachment in the form of two spaced
apart parallel pins or the like. The spacing between the jaws in
the non-engaging position is such that when a first pin of the
implement is positioned in the U shaped fixed jaw the implement can
be rotated to position the second pin opposite the U shaped opening
of the moveable jaw. Moving the moveable jaw to the engaging
portion increases the spacing between the fixed and movable jaws
and locks the moveable jaw in the coupler.
[0033] In preferred embodiments the first sensor is located
adjacent the moveable jaw.
[0034] In preferred embodiments the first sensor is positioned so
as to be abutted by a portion of the implement when, in use, the
implement is positioned such that the second attachment portion is
engageable by the moveable jaw. In use, when the implement is
rotated to position the second pin opposite the moveable jaw the
second attachment portion, or part of the implement, abuts the
coupler. The weight of the implement presses on the sensor to
indicate the second attachment portion is in a safe position, i.e.
the first attachment portion of the implement is secured in the
fixed jaw and cannot, for example, bounce free.
[0035] Preferably the first sensor is positioned so as to abut the
second attachment portion of the implement, or part thereof.
[0036] It will be appreciated that the first sensor may be
positioned in a number of locations along the length of the body
portion, provided it is capable of either directly or indirectly
detecting when the second attachment portion is opposite to and
engageable by the moveable jaw. In use, the first attachment
portion is hooked/engaged by the first/fixed jaw of the coupler.
The coupler is then rotated, causing the second attachment portion
to swing towards the coupler. When the first sensor detects the
second attachment portion as being opposite the moveable jaw, the
operator can activate the moveable jaw to lock the implement in
place. Alternatively, if the implement only requires moving, or
lifting, onto a transport vehicle the operator does not necessarily
need to activate the moveable jaw. The reason for this is that when
the second attachment portion of the implement is detected as being
located proximate the coupler body the first attachment portion is
located within the first, or fixed, jaw of the coupler. In this
position the weight of the implement is sufficient to prevent the
implement from unhooking from the first/fixed jaw. In some
embodiments the functionality of the machine may be limited when
the moveable jaw is not engaged with the second attachment portion
of the implement, for example the maximum speed, angle on which the
machine will operate, rate of movement of one or more components,
or height to which the implement can be lifted may be limited.
[0037] In use, when the first attachment portion of an implement is
engaged with the fixed jaw, sensing of the implement as being
adjacent to the body portion at a location spaced apart from the
fixed jaw indicates the angular position of the coupler relative to
the implement.
[0038] In some preferred embodiments the coupler may include a
second sensor configured to detect whether the movable jaw is in
the engaging position, or non-engaging position. The second sensor
may take a number of forms. However it will typically take the form
of a sensor configured to measure the state of an actuator
associated with movement of the moveable jaw.
[0039] In some preferred embodiments the coupler may include a
third sensor configured to detect the presence of the first
attachment portion within the fixed jaw.
[0040] In some preferred embodiments the second sensor may sense
the position of a component associated with the moveable jaw.
[0041] Preferably the actuator is a hydraulic cylinder and the
second sensor is configured to measure the expansion and/or degree
of contraction of the actuator.
[0042] In use, the first sensor is used in combination with the
second sensor and/or third sensor to indicate whether the implement
is securely retained by the coupler. It will be appreciated by a
person skilled in the art that for the implement to be securely
retained the implement first attachment portion must be retained in
the first jaw, the implement must be adjacent to the body portion
of the coupler and the moveable jaw must be in the engaging
position.
[0043] The third sensor indicates that the first attachment portion
has been hooked by the fixed jaw; this indicates to the operator
that the coupling can be safely rotated. The first sensor indicates
when the second attachment is positioned opposite the moveable jaw,
this indicates that the first attachment portion is safely secured
in the fixed jaw and also indicates that the implement can be
locked into position by moving the moveable jaw to the engaging
position. The second sensor indicates that the movable jaw is in
the engaging position.
[0044] According to a further aspect of the present invention there
is provided a system for coupling an implement to a machine, the
system including:
[0045] a coupler having a body portion including a fixed jaw
attached to the body portion and configured to engage a first
attachment portion associated with the implement; a moveable jaw
moveably attached to the body portion and configured to engage a
second attachment portion associated with the implement;
[0046] an attachment between the coupler and the machine, the
attachment configured to impart a rotation to the coupler about a
pivot axis parallel to a width of the fixed jaw, wherein, in use,
rotation of the coupler about the pivot axis allows the body
portion of the coupler to be rotated relative to the implement
first attachment portion, and
[0047] a first sensor located on the body portion configured to
detect the presence of the implement adjacent to the body portion
and at a location spaced apart from the fixed jaw.
[0048] In some preferred embodiments the system for coupling may
include a second sensor configured to detect the position of the
movable jaw. It should be appreciated that measurement of the
position of the movable jaw may be made directly, or indirectly.
Direct measurement may involve, for example measuring the physical
position of the jaw. Indirect measurement may involve sensing the
position of a component associated with the moveable jaw. In such
alternatives the position of the component being measured is
directly relatable to the position of the moveable jaw.
[0049] Preferably the second sensor configured to detect the
position of the movable jaw senses whether the movable jaw is in an
engaging position, or a non-engaging position.
[0050] In some preferred embodiments the system may include a third
sensor configured to detect the presence of the first attachment
portion within the fixed jaw.
[0051] In preferred embodiments the system includes an indicator
unit. The indicator unit provides an indication to an operator of
the system when the presence of the implement is detected as being
adjacent to the body portion.
[0052] In preferred embodiments the indicator unit includes an
electronic indicator; examples of electronic indicators may
include, but should not be limited to, visible lights such as LEDs,
alarms, buzzers or tactile feedback or the like.
[0053] In preferred embodiments the indicator unit is located
remotely to the coupler.
[0054] In some preferred embodiments the system may be integrated
with, or coupled to, a control system associated with a machine to
which the coupler is attached.
[0055] In some preferred embodiments the control system associated
with the machine to which the coupler is attached may limit one or
more functions of the machine if, in use, the implement is not
sensed as being adjacent to the body portion. Non-limiting examples
of appropriate features that may be limited are, hydraulic power, a
reduced range of motion, a reduced rate of movement, or
similar.
[0056] According to a further aspect of the present invention there
is provided a method of coupling an implement to a machine using a
coupler, the coupler having a body portion including a fixed jaw
attached to the body portion and configured to engage a first
attachment portion associated with the implement; a moveable jaw
moveably attached to the body portion and configured to engage a
second attachment portion associated with the implement, and a
first sensor located on the body portion configured to detect the
presence of the implement adjacent to the body portion and at a
location spaced apart from the fixed jaw, the method including the
steps of:
[0057] engaging the implement first attachment portion with the
fixed jaw;
[0058] rotating the coupler about a pivot axis parallel to a width
of the fixed jaw so as to move the underside of the body portion
towards the implement;
[0059] detecting, by way of the first sensor, whether the second
attachment portion of the implement is in a position in which it
can be engaged by the moveable jaw;
[0060] outputting a signal indicative of whether the second
attachment portion is in a position in which it can be engaged by
the moveable jaw.
[0061] In use, the outputting of a signal of step d) indicates the
implement is in a position whereby the implement can be locked into
position by the moveable jaw.
[0062] According to a further aspect of the present invention there
is provided a sensor configured to be used with a coupler for
attaching an implement to a machine, the sensor including
[0063] an insulating portion formed from a resilient electrically
insulating material, the insulating portion having a base on one
side and a receiving surface on the opposite side; and
[0064] a conductive member configured to be retained on the
receiving surface,
[0065] wherein the conductive member is electrically isolated from
the base of the insulating portion.
[0066] In use the sensor operates in conjunction with the chassis
of the machine to which the coupler is attached. The machine,
coupler body, and implement to be attached form an electrically
conductive path through which a current can flow. In use current
passes through the machine, into the coupler and through the
implement via the first attachment; which is held in the fixed jaw.
The implement forms a mechanical switch which is closed, i.e.
conducts current, when a portion of the implement abuts the
conductive member of the sensor. When the implement first
attachment is located in the first jaw and the implement does not
contact the conductive member of the sensor a closed circuit is not
formed and no current flows. Preferably an insulated return wire is
provided from the conductive member to a detection circuit.
[0067] In preferred embodiments the conductive member is configured
to be electrically coupled to an electrical signal detector.
[0068] In preferred embodiments the conductive member is configured
to project outwards from the receiving surface of the insulating
portion.
[0069] In preferred embodiments the base is configured to be
attached to a surface of the coupler.
[0070] In preferred embodiments the insulating portion is
elongate.
[0071] In preferred embodiments the conductive member is
elongate.
[0072] In preferred embodiments the conductive member is
configured, in use, to abut a portion of an implement when a second
attachment portion of the coupler is in a position in which it can
be engaged by a moveable jaw of the coupler.
[0073] In preferred embodiments the sensor is configured to be
compressed between a portion of the implement and a portion of the
coupler body.
[0074] Preferred embodiments of the present invention may provide a
number of advantages over the prior art, examples of which may
include:
[0075] indicating to an operator when an implement is in a position
in which actuating a moveable jaw of a coupler will engage the
moveable jaw with the implement, thereby securing the implement to
the coupler;
[0076] providing a warning to an operator when an implement is no
longer securely held in a secure position, for example in the event
whereby the actuator fails and disengages the moveable jaw;
[0077] providing a warning system that indicates an unsafe
condition whereby an implement may be engaged with the coupler, but
due to wear, or actuator fault may not be safely held in the
coupler.
BRIEF DESCRIPTION OF DRAWINGS
[0078] Further aspects of the present invention will become
apparent from the following description which is given by way of
example only and with reference to the accompanying drawings in
which:
[0079] FIG. 1a shows a plan view of a coupler in accordance with
one preferred embodiment of the present invention;
[0080] FIG. 1b shows a plan view of the coupler of FIG. 1 in an
engaged position;
[0081] FIG. 2 shows a cross sectional view of the coupler of FIG.
1.
[0082] FIG. 3a shows a perspective view of a sensor in accordance
with one preferred embodiment of the present invention;
[0083] FIG. 3b shows an exploded view of the sensor of FIG. 2a;
[0084] FIG. 4 shows a plan view of the coupler of FIG. 1 and an
attached implement in an unsecure position;
[0085] FIG. 5 shows a plan view of the coupler of FIG. 1 and an
attached implement in a secure position;
[0086] FIG. 6 shows a plan view of the coupler of FIG. 1 and an
attached implement in an engaged position,
[0087] FIGS. 7a-7c show schematic views of a system for coupling an
implement to a machine in accordance with one preferred embodiment
of the present invention.
BEST MODES FOR CARRYING OUT THE INVENTION
[0088] With reference to FIG. 1a, 1b, 2 and 4, 5 and 6 there is
shown a coupler as generally indicated by 1. Coupler 1 includes a
body portion 2 to which is attached a fixed jaw 3. The jaw 3 is
fixed in the sense that it does not move with respect to the body
portion 2. It will be appreciated that fixed jaw 3 may take a
number of forms without departing from the scope of the present
invention. For example, fixed jaw 3 may be formed integrally with
the body portion of coupler 2, or it may be attached to the body
portion 2 by way of bolts or other suitable fasteners.
[0089] Fixed jaw 3 includes a `U` shaped opening 3a facing in an
outward direction substantially parallel to the length of the body
portion. The `U` shaped opening is configured to receive the
circular cross section of a first attachment pin 12a (shown in FIG.
2) of an implement (shown in FIGS. 4, 5 and 6) the first pin 12a
extends across the width of the fixed jaw 3 so as to be
substantially transverse to the length of body portion 2.
[0090] A moveable jaw 4 is moveably attached to the body portion 2.
The movable jaw 4 includes a substantially `U` shaped engaging
portion 4a, the opening of the `U` facing in an opposite direction
to the `U` shape of the fixed jaw 3. The `U` shaped engaging
portion 4a is configured to receive a second attachment pin 12b
(shown in FIG. 2), which, in use, extends across the width of the
movable jaw 4. In the embodiment shown in FIG. 2 a second sensor 40
detects the position of movable jaw 4 by measuring the position of
the shaft of hydraulic ram 41 (shown in FIG. 2), and a third sensor
14 detects the presence of first pin 12a in fixed jaw 3.
[0091] The moveable jaw 4 is configured to slide along a portion of
the length 4b of the coupler body portion 2 towards and away from
fixed jaw 3. In use, movement of the moveable jaw 4 alters the
spacing between the fixed jaw 3 and the moveable jaw 4, this
movement facilitates the clamping, or engagement of an implement
with the coupler 1. It should be appreciated that alternatives to
sliding movement of the moveable jaw 4 may be considered, for
example, the movable jaw may rotate rather than slide. The manner
in which the fixed jaw and moving jaw provide clamping of an
implement is explained in greater detail later in this document
with respect to FIGS. 2 to 5.
[0092] A person skilled in the art will appreciate that the
configuration of the fixed jaw 3 and moveable jaw 4 will depend on
the type of attachment portions provided on a particular
implement
[0093] The moveable jaw 4 is moveable between a non-engaging
position, shown in FIG. 1a wherein the moveable jaw is positioned
relatively closer to the fixed jaw 3 and an engaging position,
shown in FIG. 1b, wherein the moveable jaw 4 is positioned
relatively further from the fixed jaw 3.
[0094] The coupler 1 also includes a first sensor 5 located on the
body portion 2, the first sensor 5 is positioned adjacent to the
moveable jaw 4.
[0095] Referring now to FIGS. 3a and 3b that show the sensor 5 in
more detail, the first sensor 5 includes an insulating portion 6
formed from a resilient electrically insulating material. The
insulating portion 6 has a base 7 on one side and a receiving
surface 8 on the opposite side. A cable 10 is sandwiched between
conductive member 9 and the receiving surface 8 to which the
conductive member 9 is attached. The insulating portion 6 base 7
is, in use, attached to the coupler body 2. Because the conductive
member 9 is insulated by the insulating portion 6 there is no
electrical connection between the coupler body and the conductive
member 9. In use the conductive member 9 is configured to abut a
portion of an implement. If the implement is in contact with the
coupler body portion, for example by way of a first attachment
portion of an implement being held by the fixed jaw 3, and the
implement is in contact with the conductive member 9 an electrical
circuit is completed between the coupler 1, through the body of the
implement, and the cable.
[0096] It should however be appreciated that the present invention
could be performed using various types of sensors, such as, for
example, proximity sensor, mechanical switches, or the like.
[0097] Typically the first sensor 5 will be elongate, so as to
cater for a range of differently spaced first and second attachment
pins. The insulating portion 6 compresses when an implement presses
against the conductive member 9, this allows contact to be made
between the implement and the conductive member 9 whilst allowing
the implement to bear against the body portion 2.
[0098] Coupler 1 is configured to attach to a machine by way of
connection points 11a and 11b. Typically the machine will include
an articulated arm such as a back hoe. Connection points 11a and
11b allow for rotation of the coupler about an axis substantially
parallel to the width of the fixed jaw 3.
[0099] With reference to FIGS. 4 to 6 there is shown a coupler 1 to
which an implement in the form of an excavator bucket 12 is
attached. Excavator bucket 12 includes a first attachment portion
in the form of pin 12a and a second attachment portion, spaced
apart from the first attachment portion, in the form of pin 12b.
FIG. 2 shows the implement 12 first attachment portion pin 12a
engaged within fixed jaw 3.
[0100] FIG. 4 shows the coupler of FIG. 2 in a position in which
the coupler 1 has been rotated about a pivot axis parallel to a
width of the fixed jaw 3. Rotation is facilitated by an attachment
(not shown) between the coupler 1 and the machine (not shown).
[0101] Rotation of the coupler 1 rotates the body portion 2
relative to the first attachment portion pin 12a, thereby moving
the moveable jaw 4 towards the second attachment portion 12b. It
will be appreciated that, in use, the implement will typically hang
from the fixed jaw 3 by way of the first attachment portion pin
12a. The hanging orientation of the implement will therefore be
dictated by its centre of mass relative to the first attachment
portion pin 12a.
[0102] Rotation of the coupler 1 results in the excavator bucket 12
second attachment portion 12b pressing against the first sensor 5
conductive member 9 compressing insulating portion 6. Compression
of the insulating portion 6 allows the second attachment portion
12b to bear against the coupler body portion 2 whilst completing an
electrical circuit through the coupler fixed jaw 3, the first
attachment portion 12a, the excavator bucket 12, the second
attachment portion 12b, the conductive member 9 and cable 10.
[0103] Completion of the electrical circuit is indicative of the
position of pin (12b) with respect to the body portion (2).
Therefore, it is possible to determine whether the coupler (1) is
in a position in which movable jaw (4) can engage pin (12b).
Completion of the circuit results in an indication to a user that
the implement second attachment portion pin 12b is in a position in
which the movable jaw 4 can be moved from a non-engaging position
(shown in FIG. 4), wherein the second engagement portion 12b is
able to move freely relative to the body portion 2, to an engaging
position (shown in FIG. 6), wherein the second engagement portion
12b is engaged by, and held substantially fixed relative to, the
body portion 2 by the moveable jaw 4.
[0104] With respect to FIGS. 7a to 7c there is shown a schematic of
a system for coupling an implement to a machine. The system
includes coupler 30 of the type shown in FIGS. 1 to 2, coupler 30
includes a third sensor 31 which is provided for association with
the fixed jaw and is positioned so as to detect the presence of the
first attachment portion 12a within the fixed jaw. A first sensor
32 is positioned adjacent the moveable jaw and is configured to
detect the presence of the implement when it is adjacent to the
body portion of the coupler. An indicator unit 33 is located
remotely from the coupler 30 and includes a relay switch 36 to
toggle between safe indication light source 34 and unsafe
indication light source 35. The third sensor 31 and first sensor 32
are connected in parallel by way of sense wire 37 and through the
chassis 38 of the coupler.
[0105] The circuit through sense wire 37 is completed when either
third sensor 31, or first sensor 32, provides a current path. When
current flows through sense wire 37, relay 36 activates safe
indication light source 34, shown in FIGS. 7a and 7b. Activation of
safe indication light source 34 can occur in two circumstances:
[0106] the first attachment portion pin 12a is not located in the
fixed jaw and second attachment portion pin 12b is not detected as
being adjacent the coupler body, OR
[0107] the first attachment portion pin 12a is located in the fixed
jaw and second attachment portion pin 12b is detected as being
adjacent the coupler body.
[0108] Variants that include a second sensor for measuring the
position of the moveable jaw 4, shown in FIG. 2, will also require
that the moveable jaw is in the engaged position. This is in
addition to the requirements detailed in step b) above. Typically
such variants would incorporate a second sensor which sits in
parallel with the first and third sensors. When the jaw is in a
non-engaging position the second sensor 40 completes the circuit
through sense wire 37 and thereby indicates an unsafe condition.
The advantage of monitoring the position of the moveable jaw is
that if the actuator, hydraulic ram of FIG. 2, fails and
disengages, or fails to move, the moveable jaw to engage the second
work attachment pin 12b the operator is alerted.
[0109] It will be appreciated by persons skilled in the art that
the system of FIGS. 7a-7c is provided by way of example only and
that there are numerous circuit configurations that could provide
the same or similar functionality, therefore the example provided
should not be seen as being limiting.
[0110] In some alternatives the system may also include a further
sensor (not shown) that indicates the position of the movable jaw
4. Numerous alternatives exist by which the jaw position could be
measured, not limiting examples of which include, measuring the
shaft position of a hydraulic cylinder associated with the movable
jaw, measuring a hydraulic pressure provided to the movable jaw, or
direct measurement of the position of the jaw.
[0111] In some alternatives the system may also limit one or more
functions of the machine when an implement is not detected as being
secure within the fixed jaw, i.e., when the unsafe indication light
source 35 is active. Non-limiting examples of limitation of one or
more functions of the machine may include reduced hydraulic power,
a reduced range of motion, or a reduced rate of movement.
[0112] It will be appreciated by persons skilled in the art that
the detection of the implement moving away from the body of the
coupler may be indicative of a number of unsafe conditions. For
example, in the event in which the actuator fails and releases one
of the implement pins the implement will swing away from the
coupler, at which time the operator will be alerted as to the
unsafe operating condition.
[0113] A further example is the situation whereby the implement
pins may be worn. Whilst pin detection sensors in the jaws may
indicate the presence of the pins in the jaws, indication of the,
or a, pin moving away from the coupler body, but still remaining
within the jaw, is indicative of pin wear. If a pin is worn to the
point whereby it begins to move away from the coupler body during
use, the operator will be alerted. Once the pins begin moving in
the coupler jaws during use the rate of wear will increase
substantially. By alerting the operator early remedial action may
be taken early avoiding costly downtime in the event of a pin
failure, and also avoiding safety risks
[0114] Aspects of the present invention have been described by way
of example only and it should be appreciated that modifications and
additions may be made thereto without departing from the scope
thereof.
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