U.S. patent application number 17/254423 was filed with the patent office on 2021-04-29 for coupler control system.
This patent application is currently assigned to Miller UK Limited. The applicant listed for this patent is Miller UK Limited. Invention is credited to Gary MILLER, Keith MILLER, Howard REAY, Gavin URWIN, Stephen VERLANDER.
Application Number | 20210123211 17/254423 |
Document ID | / |
Family ID | 1000005360216 |
Filed Date | 2021-04-29 |
United States Patent
Application |
20210123211 |
Kind Code |
A1 |
MILLER; Keith ; et
al. |
April 29, 2021 |
COUPLER CONTROL SYSTEM
Abstract
A coupler control system (10) for coupler on an excavator arm
(14) of an excavator (12), the coupler comprising a hydraulic
actuator (60), the excavator comprising a solenoid valve (20) for
controlling operation of the coupler's hydraulic actuator (60), the
excavator arm (14) comprising a boom arm (36) and a stick (40),
both operated by separate hydraulic actuators, and a bucket
actuator (44) for rotating an accessory relative to the stick (40),
the coupler control system (10) comprising a controller linked to
the solenoid valve (20) for controlling operation of the coupler's
hydraulic actuator (60), a status indicator (22), a coupler control
switch (24) for locating in the cab of the excavator and a pressure
sensor (28) for connecting to the hydraulic system for at least one
of the hydraulic actuators for the boom arm, the stick or the
bucket actuator, wherein the coupler control switch and the status
indicator are connected to the controller, the pressure sensor is
arranged to sense when the hydraulic fluid of the hydraulic system
is at a pressure less than a predetermined pressure signifying a
grounding of the coupler, the controller is connected to the
pressure sensor to detect that sensed state of the pressure and the
controller is arranged, in response to that detection, to provide
an indication to the operator via the status indicator.
Inventors: |
MILLER; Keith; (Cramlington,
GB) ; MILLER; Gary; (Cramlington, GB) ; URWIN;
Gavin; (Cramlington, GB) ; REAY; Howard;
(Cramlington, GB) ; VERLANDER; Stephen;
(Cramlington, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Miller UK Limited |
Cramlington Northumberland |
|
GB |
|
|
Assignee: |
Miller UK Limited
Cramlington Northumberland
GB
|
Family ID: |
1000005360216 |
Appl. No.: |
17/254423 |
Filed: |
June 21, 2019 |
PCT Filed: |
June 21, 2019 |
PCT NO: |
PCT/GB2019/051750 |
371 Date: |
December 21, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02F 3/3618 20130101;
E02F 9/264 20130101; E02F 3/3622 20130101; E02F 3/3663 20130101;
E02F 9/226 20130101 |
International
Class: |
E02F 9/22 20060101
E02F009/22; E02F 9/26 20060101 E02F009/26; E02F 3/36 20060101
E02F003/36 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 25, 2018 |
GB |
1810410.9 |
Claims
1. A coupler control system for coupler on an excavator arm of an
excavator, the coupler comprising a hydraulic actuator, the
excavator comprising a solenoid valve for controlling operation of
the coupler's hydraulic actuator, the excavator arm comprising a
boom arm and a stick, both operated by separate hydraulic
actuators, and a bucket actuator for rotating an accessory relative
to the stick, the coupler control system comprising: a controller
linked to the solenoid valve for controlling operation of the
coupler's hydraulic actuator; a status indicator; a coupler control
switch for locating in the cab of the excavator; and a pressure
sensor for connecting to the hydraulic system for at least one of
the hydraulic actuators for the boom arm, the stick or the bucket
actuator; wherein: the coupler control switch and the status
indicator are connected to the controller; the pressure sensor is
arranged to sense when the hydraulic fluid of the hydraulic system
is at a pressure less than a predetermined pressure signifying a
grounding of the coupler; the controller is connected to the
pressure sensor to detect that sensed state of the pressure; and
the controller is arranged, in response to that detection, to
provide an indication to the operator via the status indicator.
2. The coupler control system of claim 1, wherein the predetermined
pressure is a set pressure between 0 and 60 barg.
3. The coupler control system of claim 1, wherein the status
indicator is a visual indicator.
4. The coupler control system of claim 1, wherein the connection to
the solenoid valve is via a connection to a solenoid valve manifold
assembly comprising the solenoid valve for controlling operation of
the coupler's hydraulic actuator and solenoid valves for the boom
arm's actuator.
5. The coupler control system of claim 4, wherein the pressure
sensor is part of the manifold assembly.
6. The coupler control system of claim 1, wherein the pressure
sensor is remote from the controller, it being connected to the
hydraulics for the boom arm's actuator.
7. The coupler control system of claim 1, wherein the controller
has a plug socket to fit in a control socket on the solenoid valve
for controlling operation of the coupler's hydraulic actuator or a
manifold assembly comprising the solenoid valve for controlling
operation of the coupler's hydraulic actuator, and a second control
socket to receive an OEM plug socket connected to the cab control
cables, the controller thus then being connectable to the excavator
between the OEM plug socket and the solenoid valve for controlling
operation of the coupler's hydraulic actuator or the manifold
assembly comprising the solenoid valve for controlling operation of
the coupler's hydraulic actuator.
8. The coupler control system of claim 1, wherein the status
indicator comprises a visual indicator provided on the excavator
arm, which visual indicator is within the line of sight of an
operator sitting in a cab of the excavator.
9. The coupler control system of claim 1, wherein the status
indicator comprises a visual indicator in a cab of the excavator,
which visual indicator is within the line of sight of an operator
sitting in a cab of the excavator.
10. (canceled)
11. The coupler control system of any preceding claim, wherein the
status indicator is a visual indicator that can display more than
one colour, a first colour signifying the detection of the pressure
below the predetermined pressure for the boom cylinder hydraulics,
and the second colour signifies operation of the coupler's actuator
by the coupler control switch.
12. (canceled)
13. The coupler control system of claim 1, further comprising a
counter for counting a period of detection of the pressure below
the predetermined pressure wherein the coupler control system
disables operation of the coupler control switch until a
predetermined time period of the pressure below the predetermined
pressure has passed.
14. (canceled)
15. The coupler control system of claim 13, wherein the
predetermined time period is at least 3 seconds.
16. An excavator comprising an excavator arm with a coupler on an
end thereof, the coupler comprising a hydraulic actuator for
opening and closing a latch of the coupler, the excavator
comprising a solenoid valve for controlling operation of the
coupler's hydraulic actuator, the excavator arm comprising a boom
arm and a stick, both operated by separate hydraulic actuators,
wherein the excavator comprises a coupler control system for the
coupler, the excavator comprising a solenoid valve for controlling
operation of the coupler's hydraulic actuator, and a bucket
actuator for rotating an accessory relative to the stick, the
coupler control system comprising: a controller linked to the
solenoid valve for controlling operation of the coupler's hydraulic
actuator; a status indicator; a coupler control switch for locating
in the cab of the excavator; and a pressure sensor for connecting
to the hydraulic system for at least one of the hydraulic actuators
for the boom arm, the stick or the bucket actuator; wherein: the
coupler control switch and the status indicator are connected to
the controller; the pressure sensor is arranged to sense when the
hydraulic fluid of the hydraulic system is at a pressure less than
a predetermined pressure signifying a grounding of the coupler; the
controller is connected to the pressure sensor to detect that
sensed state of the pressure; and the controller is arranged, in
response to that detection, to provide an indication to the
operator via the status indicator.
17. The excavator of claim 16, wherein the coupler controlled by
the coupler control system comprises a front jaw for receiving a
first attachment pin of an accessory, a rear jaw for receiving a
second pin of the accessory, the latch being associated with the
rear jaw and the hydraulic actuator being associated with the
latch.
18. (canceled)
19. The excavator of claim 17, wherein the coupler comprises a
latching member for the front jaw in addition to the latch for the
rear jaw.
20. The excavator of claim 19, wherein the latching member for the
front jaw is operated also by operation of the hydraulic actuator
of the coupler either directly or via a release mechanism.
21. (canceled)
22. A method of controlling decoupling an accessory from a coupler
on an excavator arm of an excavator, the excavator being as defined
in claim 16, wherein if the excavator arm, coupler and accessory
are maintained not in contact with the ground, with the boom arm
actuator carrying the boom arm, the stick, the coupler and the
accessory, the decoupling procedure cannot commence, whereas upon
contacting the ground with the accessory for a predetermined period
of time not less than two seconds, whereby the coupler control
system detects a pressure in the hydraulics for the boom arm
actuator of less than a predetermined pressure not more than 60
barg for that predetermined period, the status indicator will then
provide an indication of readiness to decouple whereafter the
coupler control switch can be switched to cause the decoupling
process to occur.
23. The method of claim 22, wherein said switching of the coupler
control switch is from a first state to a different, accessory
decouple, state.
24. The method of claim 22, wherein if the coupler control switch
is in an accessory decouple state when the accessory is first
touched to the ground to commence the determination of the
predetermined time period, the decoupling procedure cannot commence
until the switch is switched into a non-decouple state, and the
time period determination recommenced.
25. The method of claim 22, wherein the decoupling procedure, when
commenced will additionally control the excavator arm to raise the
coupler off the accessory after completion of the decoupling
procedure.
26. (canceled)
27. (canceled)
Description
[0001] The present invention relates to a coupler control system
for controlling the coupling or decoupling of an accessory onto or
from a coupler on an excavator arm of an excavator. One such
accessory could be an excavator bucket.
[0002] Couplers, also known as quick couplers, quick hitches or
excavator couplers, for coupling accessories to the excavator arm
of an excavator are well known in the art. The couplers generally
comprise a top part that is connectable to an excavator arm using
two attachment pins (via two pairs of holes provided for those
attachment pins) and a bottom part for engaging two further
attachment pins, on the accessory. In modern couplers, the bottom
part typically comprises two jaws, rather than holes. Those jaws
engage respective ones of those two further attachment pins of the
accessory, and a closure mechanism for at least one of those jaws
is provided, usually driven by an actuator, such as a screw-drive,
or a hydraulic cylinder, operable from the cab of the excavator via
a coupler control system, for actuating the closure mechanism
between a closed and open position. The closed position secures the
accessory to the coupler by the pins being locked into the
jaws.
[0003] A common feature of many such couplers is that one of the
two jaws is usually referred to as a front jaw. Its opening (for
receiving a first or front one of the two attachment pins of the
accessory) is generally directed out of a first end of the coupler.
This first end is commonly referred to as the front end as it is
the end that is guided first onto an accessory pin. The direction
that the opening faces the forward direction lies generally
parallel to an imaginary line joining the two pairs of holes in the
top part of the coupler, as used for attachment of the coupler to
the end of the excavator arm, i.e. at a zero angle thereto.
Sometimes the direction that the opening faces is angled slightly
upwards from that line, perhaps by up to an angle of up to
15.degree. from parallel to then ramp the bottom wall to tend to
hold the first pin therein, but often it is parallel to that
line.
[0004] The second jaw is then usually referred to as a rear jaw, as
it lies nearer the opposite (back or rear) end of the coupler,
albeit in the bottom wall of the coupler. It generally opens
downwardly, i.e. in a direction that is generally perpendicular to
the line of the front jaw, or the imaginary line between the two
pairs of holes in the top half of the coupler. As with the front
jaw, the rear jaw also may be off that perpendicular, perhaps by up
to 15.degree..
[0005] The jaws from the side of the coupler appear singular, but
often the jaws are bifurcated--especially the rear jaw, as there
are working mechanisms inside the coupler, and they often need to
be serviceable, whereby the two parts allow a gap between them for
accessing the serviceable parts.
[0006] Commonly the jaws are formed integrally to the body of the
coupler, although they can be made of a harder steel than the main
body of the coupler, and joined thereto during the production of
the coupler.
[0007] For the purpose of this application we hereinafter refer to
the jaws as the rear jaw and the front jaw.
[0008] The rear jaw commonly has the closure mechanism, which
comprises a latching member and the actuator. For most couplers the
latching member is described as a hook or a closure plate. The
latching member can be slid or pivoted between a latched position
and an unlatched position by using the actuator. In the latched
position, the opening of rear jaw is at least partially closed by
the latching member. In the unlatched position, the latching member
is retracted out of the latching position so as to leave the jaw's
opening as open as needed to allow the second attachment of the
accessory to be located therein. This may be a full retraction to
completely clear the opening of the rear jaw, or a less complete
retraction wherein the opening of the jaw is only partially
obscured less obscured than needed for latching the second pin of a
given accessory (different accessories may have different pin
spacing, so often there is a degree of variance in the latching
position during use of a coupler.
[0009] The unlatched position is both for allowing upward insertion
of the second attachment pin in the rear jaw, and for allowing a
previously captured second attachment pin to be removed from the
rear jaw downwardly.
[0010] The insertion [or removal] of the second attachment pin with
respect to the rear jaw is usually after [prior to] capture of the
first attachment pin in the front jaw, and is achieved by rotating
the coupler to drop [lift] the rear jaw relative to the front jaw.
During either the attachment or decoupling of the accessory, it is
best if the accessory is on the ground, or a solid surface, so that
it is less likely to move unintentionally relative to the coupler.
However, many latching mechanisms require a degree of inversion of
the coupler to release a blocking member within the coupler, which
inverted condition is typically a "crowd" position a term in the
art referring to the position in which the arm and coupler is
curled under and towards the cab to locate the first attachment pin
of the accessory above the second attachment pin, i.e. the front
jaw pointing generally upwards. See, for example, GB2330570,
GB2441332 and WO2008/029112. Difficulties with this action,
however, include the need to train the operator, the common need to
have the accessory above the ground, and the typical need to put
the boom arm pointing fairly high up in the air to allow the
accessory to rotate under the excavator arm, whereby it is
difficult to achieve in a low-height tunnel.
[0011] It would therefore be desirable to provide a system for
operating a coupler during the coupling or decoupling process, and
a coupler for use with this process, wherein the method of
attachment and/or detachment is made more straightforward, but in
which the prevention of incorrect attachment and detachment is
retained.
[0012] According to the present invention there is provided a
coupler control system for coupler on an excavator arm of an
excavator, the coupler comprising a hydraulic actuator, the
excavator comprising a solenoid valve for controlling operation of
the coupler's hydraulic actuator and the excavator arm comprising
at least a boom arm operated by a first hydraulic excavator
actuator, the coupler control system comprising a control system,
usually comprising a controller, or boxes, for attaching to the
solenoid valve of the excavator, either directly or via a cable, or
wirelessly, a status indicator and a coupler control switch for
locating in the cab of the excavator, wherein the coupler control
switch and the status indicator are connected to the controller,
characterised in that the coupler control system comprises a
pressure sensor for connecting to the hydraulic system for the boom
arm's hydraulic actuator, the pressure sensor being arranged to
sense when the hydraulic fluid of the boom arm's hydraulic actuator
is at a pressure less than 50 barg, the controller being connected
to the pressure sensor to detecting that sensed state and being
arranged, in response thereto, to provide an indication to the
operator via the status indicator.
[0013] The controller may be in the form of a single controller. It
may be directly connected to the solenoid valve of the coupler's
actuator, or it may be wirelessly connected thereto.
[0014] Instead of the pressure sensor looking at the pressure of
the boom arm's hydraulic fluid, it may look at the hydraulic fluid
pressure of the hydraulic actuator for the stick, or the hydraulic
fluid pressure for a bucket actuator (for rotating the accessory
relative to the stick). If any of these are between 0 and 60 barg,
this again signifies that the excavator arm is not loaded by a
weight at the end of the arm, signifying that the accessory is
grounded. This action can be known as a touch on the ground.
[0015] In a preferred arrangement, the excavator arm comprises all
three actuators for the boom arm, the stick and the bucket actuator
and a manifold for solenoid valves for ach of them. The manifold
can also have the solenoid valve for the coupler's actuator. The
pressure being looked at is the main pressure driving the relevant
actuator, be that as preferred the boom arm, or instead the stick
actuator, or the bucket actuator.
[0016] Commonly a pressure sensor is mounted either on the actuator
or by the solenoid valve therefor. It could instead be in a feed
line.
[0017] Instead of the monitored pressure being below 50 barg, the
monitored pressure for any particular excavator actuator might be
below any predetermined pressure, that alternative predetermined
pressure being perhaps the minimum pressure needed in the
hydraulics for the boom cylinder for the boom cylinder to lift the
free end of the excavator arm, be that with or without a coupler
and accessory, off the ground. That minimum pressure will vary
dependent upon the size of the excavator arm or the position of the
stick, and can be custom set for any given excavator
arm/coupler/accessory arrangement a smaller excavator arm, for
example, may require a smaller predetermined pressure as the
trigger. A figure well below that minimum, however, is useful as it
will operate straight away for a wider range of excavator arms.
Preferably it is 50 barg, or a predetermined pressure between 10
barg and 60 barg.
[0018] Preferably the status indicator is a visual indicator. It
may be an audio indicator or both an audio and visual
indicator.
[0019] Preferably the pressure sensor is connected to the
controller by a wired connection. Alternatively it could be a
wireless connection. The switch and sensor might likewise be
wirelessly connected to the control system, or wired thereto.
[0020] In a preferred system, the sensor, the switch, status
indicator and the controller are all discrete units, connected
together wirelessly.
[0021] Preferably the solenoid valve of the excavator is a solenoid
valve manifold comprising also a solenoid valve for the boom
actuator. The pressure sensor thus might be part of the controller.
Alternatively the pressure sensor may be separate thereto for
example attached to a solenoid valve of the boom arm actuator, such
as at the base of the boom arm.
[0022] Preferably the controller has a plug socket to fit in a
control socket on the solenoid or manifold, and a second control
socket to receive an OEM plug socket connected to the cab control
cables, the controller thus then being connectable to the excavator
between the OEM plug socket and the solenoid or manifold.
[0023] In one embodiment, the status indicator is provided on the
excavator arm, and has a visual indicator within the line of sight
of the operator to the excavator arm.
[0024] Alternatively, the status indicator can be in the cab of the
excavator, for example a visual indicator in or on a sun visor of
the excavator or in or on a screen pillar of the excavator.
Alternatively, the visual indicator could be incorporated into the
coupler control switch or into or on the dashboard of the
excavator, or elsewhere visible to the operator during use of the
excavator.
[0025] Haptic feedback may even be provided for the status
indicator.
[0026] Preferably the status indicator comprises an array of
LEDs.
[0027] Preferably the status indicator is a visual indicator that
can display more than one colour, a first colour signifying the
detection of the below 50 barg status for the boom cylinder
hydraulics.
[0028] Preferably that indication is amber.
[0029] Preferably the second colour signifies operation of the
coupler's actuator by the coupler control switch. Preferably it is
a red indicator.
[0030] Preferably the coupler control system also comprises a
counter, preferably as part of the controller. With the counter,
the coupler control system can count and indicate detection of the
pressure below 50 barg for a predetermined period of time.
Preferably the coupler control system disables operation of the
coupler control switch until that predetermined time period has
passed.
[0031] Preferably the predetermined period of time is a period of
at least two seconds and more preferably three seconds, four
seconds or five seconds. However, it may be any predetermined
period of time, although preferably non zero. It may be a time
period set by the operator. After all, an operator may prefer a
longer period of time, especially if he is less experienced with
operating the excavator.
[0032] Preferably there is a minimum period of time of at least two
seconds.
[0033] The coupler control system of the present invention may be
supplied onto the excavator during production of the excavator so
that the components thereof are integrated into the build of the
excavator. Alternatively they may be provided as a retro-fit
kit.
[0034] Preferably the visual indicator has an adhesive back for
attachment to the excavator in a line of site to the operator of
the excavator. Preferably it is attached to a side of the excavator
arm that is facing the cab.
[0035] Preferably the controller comprises a plug socket adapted to
fit a control socket provided in the solenoid valve or the solenoid
valve manifold.
[0036] Preferably the coupler controlled by the coupler control
system comprises a front jaw for receiving a first attachment pin
of an accessory, a rear jaw for receiving a second pin of the
accessory, a latch associated with the rear jaw and a hydraulic ram
associated with the latch. Preferably the latch is a latching hook.
The latch may be pivotable relative to the coupler's housing. The
hydraulic ram will be connected to the controller via the solenoid
valve.
[0037] Preferably there is no blocking mechanism in the coupler for
selectively jamming the latch against retraction from a latching
condition when the hydraulic ram is operated. As such, without the
coupler control system, the coupler would perform a decoupling
process irrespective of the orientation thereof. The coupler
control system thus providing the blocking function by deactivating
the control switch for the coupler.
[0038] The coupler may comprise a latching member for the front jaw
as well. Preferably the latch for the front jaw is operated also by
operation of the hydraulic ram either directly or via a release
mechanism. Preferably the latching member for the front jaw also
operates in response to the hydraulic ram irrespective of the
orientation of the coupler.
[0039] The coupling member for the front jaw may have an extended
condition in which it becomes disengaged from the opening mechanism
therefor.
[0040] The present invention also provides a method of decoupling
an accessory from a coupler on an excavator arm of an excavator
comprising providing a coupler control system as defined above,
wherein if the excavator arm, coupler and accessory are maintained
not in contact with the ground, the decoupling procedure cannot
commence, as the coupler control switch is deactivated, whereas
upon contacting the ground for a predetermined period of time not
less than two seconds, the coupler control system detects a
pressure in the hydraulics for the boom cylinder of less than 50
barg for that predetermined period, the visual indicator then
provides an indication of readiness to decouple whereafter the
coupler control switch is reactivated to allow a decoupling process
to occur upon the operator toggling the coupler control switch from
a first state to a different, accessory decouple, state.
[0041] Again, instead of the monitored pressure being below 50
barg, the monitored pressure might be below any predetermined
pressure, that alternative predetermined pressure being perhaps the
minimum pressure needed in the hydraulics for the boom cylinder for
the boom cylinder to lift the free end of the excavator arm, be
that with or without a coupler and accessory, off the ground. That
minimum pressure will vary dependent upon the size of the excavator
arm or the position of the stick, and can be custom set for any
given excavator arm/coupler/accessory arrangement a smaller
excavator arm, for example, may require a smaller predetermined
pressure as the trigger. A figure well below that minimum, however,
is useful as it will operate straight away for a wider range of
excavator arms. Preferably it is 50 barg, or a predetermined
pressure between 10 barg and 60 barg.
[0042] Preferably upon said toggling of the coupler control switch
from the first state to a different, accessory decouple, state, the
decoupling procedure automatically occurs by the system powering
the coupler actuator in a manner to withdraw the latching
mechanisms of the coupler.
[0043] Preferably the coupler control system additionally controls
the excavator arm to raise the coupler off the accessory after
completion of the decoupling procedure.
[0044] Preferably the raising of the excavator arm additionally
comprises rotation of the coupler to disengage the front jaw from
the accessory.
[0045] Preferably the status indicator remains off after the
predetermined time period if the coupler control switch is in the
different, accessory decouple, state when the predetermined time
period is being counted.
[0046] Preferably the deactivation of the coupler control switch is
maintained after the predetermined time period if the coupler
control switch is in the different, accessory decouple, state when
the predetermined time period is being counted.
[0047] Preferably the status indicator remains off after the
predetermined time period if the pressure exceeds 50 barg while or
after the predetermined time period is being counted. This may be
timed out after the coupler control switch is switched to the
different, accessory decouple, state.
[0048] Preferably the deactivation of the coupler control switch is
maintained if the pressure exceeds 50 barg while or after the
predetermined time period is being counted. This may be timed out
after the coupler control switch is switched to the different,
accessory decouple, state.
[0049] The present invention also provides a method of installing
the coupler control system of the present invention onto an
excavator, comprising taking the controller, unplugging an
excavator control cable from a solenoid valve of the excavator to
render the port therefor vacant, plugging in the controller into
that now vacant port, plugging in the coupler control cable into a
port on the controller, attaching the visual indicator onto the
excavator in a position that is within the line of sight of the
excavator operator when he is in his cab, and positioning the
coupler control switch in the cab of the excavator for use by the
operator. In one embodiment, the method also includes attaching a
pressure sensor to the solenoid valve for the boom arm's actuator.
Often times, however, the solenoid valve for the hydraulics of the
boom arm are integrated into a solenoid valve manifold with the
port thereof taking control cables for all the actuators of the
coupler and excavator arm.
[0050] These and other features of the present invention will now
be described in greater detail, purely by way of example, with
reference to the accompanying drawings in which:
[0051] FIG. 1 schematically shows an excavator fitted with the
coupler control system of the present invention;
[0052] FIG. 2 schematically shows an example of a coupler of the
present invention;
[0053] FIG. 3 schematically shows an example of the present
invention attached to a solenoid valve;
[0054] FIG. 4 schematically shows an alternative arrangement of the
present invention as provided for retro-fitting to an excavator
without a main solenoid manifold;
[0055] FIGS. 5 to 8 schematically show operation of an excavator
incorporating the present invention in normal use where the coupler
control switch is inoperable due to the function of the coupler
control system;
[0056] FIGS. 9 and 10 schematically show use of the excavator with
only a brief touch on the ground, whereby the excavator functions
without a long enough period of placement on the ground to allow
use of the decoupling procedure;
[0057] FIGS. 11 to 13 schematically show an embodiment where
commencement of the enablement of the coupler control switch is
achieved by placement of the coupler on the ground for more than
three seconds but it then being terminated by raising the excavator
arm;
[0058] FIGS. 14 to 16 schematically show operation of the excavator
in a manner to allow the accessory decoupling to be carried out;
and
[0059] FIG. 17 shows a flow chart for the coupler control system of
the present invention in a preferred configuration.
[0060] Referring first of all to FIG. 1, there is shown an
excavator 12 with an excavator arm 14 having an accessory 34 in the
form of a bucket on the free end thereof. The excavator arm 14
comprises a boom arm 36 with a boom actuator or cylinder 38 on a
first side thereof. A corresponding boom actuator or cylinder is
also provided on the other side thereof. The excavator arm 14
further comprises a stick 40 pivotally connected to the boom arm 36
so as to pivot under the control of an arm cylinder 42. Contraction
of the arm cylinder 42 straightens the stick relative to the boom
arm. Extension of the arm cylinder 42 instead folds the stick 40
under the boom arm 36. The boom cylinders 38 instead raise or lower
the boom arm 36.
[0061] The accessory 34 is pivotally connected to the end of the
stick 40, which connection is via a coupler that has an actuator
for controlling release of the accessory from the arm of the
excavator. A more preferred coupler would be a coupler such as the
coupler of FIG. 2. Either way, the accessory 34 can rotate relative
to the stick 40 by operation of a bucket cylinder 44, which
cylinder 44 is extended to curl the accessory 34 into a crowd
position, and which bucket cylinder 44 is contracted for opening
the bucket face 46 or tipping contents out therefrom. The accessory
34 can alternatively be mounted onto the excavator arm 14 in a
reverse direction, whereby this control action is reversed. The
actuator for controlling release of the accessory, however, still
works the same way by opening one or both jaws of the coupler into
which attachment pins of the accessory can be attached or released,
as known in the art.
[0062] The excavator 12 comprises a rear end in which an engine
therefor is located. The engine is used to power the tracks of the
excavator, but also the hydraulic systems of the excavator arm and
coupler, for operation of the various actuators or cylinders. The
engine also provides power for maintaining a charge in a battery
for the excavator.
[0063] The excavator 12 also has a cab 50 in which the operator
sits.
[0064] In that cab, a coupler control switch 24 is provided. The
coupler control switch 24 is for selective operation of the
actuator that controls the coupling or decoupling of the accessory
34 from the end of the excavator arm 14.
[0065] Finally, the excavator comprises a visual indicator 22,
visible by the operator from his seat in the cab 50, which in this
embodiment is located on a side of the excavator arm that faces the
operator.
[0066] In most excavators, an access hatch is provided towards the
back of the excavator either to the side or rear of the coupler for
accessing a solenoid valves or solenoid valve manifold of the
excavator, the solenoid valve or manifold thereof being for
controlling at least the coupler actuator that controls the
coupling or decoupling of the accessory 34 from the end of the
excavator arm 14. Preferably it is a manifold of solenoid valves so
that it also controls the boom cylinder, the bucket cylinder and
the arm cylinder.
[0067] In accordance with the present invention, a controller 18 is
connected to the solenoid valve for operation of the present
invention. If the solenoid valve is located elsewhere, the
controller would preferred to be located elsewhere too, so as still
to be on the solenoid valve or solenoid valve manifold as this
maintains simplicity for the wiring loom of the present
invention.
[0068] As shown in FIG. 2, an example of a coupler suitable for use
with the present invention is shown.
[0069] Although many forms of coupler can be used with the present
invention, both existing and new, ideally the coupler should be
able to operate the actuator that controls the coupling or
decoupling of the accessory 34 from the end of the excavator arm 14
without manipulation of the coupler into different orientations so
as to allow release of blocking members in the coupler. As such,
the preferred couplers for use with the present invention have no
blocking means for hindering movement of the latching member for
the rear jaw. An ability to block the opening of the latch for the
front jaw of the coupler, which thus then can secure the first
attachment pin of an accessory in the front jaw even if the rear
jaw is released may nevertheless be preferred so as to allow
retention of the accessory in the event of an erroneous release of
the second attachment pin in the rear jaw.
[0070] As can be seen, in FIG. 2 the coupler 16 has a top part with
two apertures 52 by way of which pins in the stick 40 of the
excavator arm can be attached to the coupler 16. Then, in the
bottom part of the coupler there is a front jaw 54 and a rear jaw
56.
[0071] The rear jaw has a pivoting latching hook 58 although a
sliding latch may alternatively be provided.
[0072] The actuator 60 that controls the coupling or decoupling of
the accessory 34 from the end of the excavator arm 14 is also
provided, and it comprises a cylinder for driving a piston 62 in
and out therefrom for moving the pivoting latching hook 58 forward
or backwards.
[0073] Due to the latching hook securing the rear pin by moving the
hook rearwardly from the front jaw, and since the first pin 68 and
the second pin 66 are relatively fixed with respect to one another
by virtue of them being mounted within the structure of the
accessory 34, the latching hook 58 can secure a first pin in the
front jaw as it tightens a second pin 66 in the rear jaw 56.
[0074] A front latching member 70 is also provided, for example to
catch the first attachment pin 68 in the event that the second
attachment pin 66 was to be missed by the swinging of the pivoting
latching hook 58, i.e. in the event of an inappropriate use of the
coupler 16. That front latching member 70 can be lifted from its
default latching condition, as shown in FIG. 2, into an open
position by virtue of a rear finger 72 on the actuator 60 being
able to engage a first side of a release arm 74 that is mounted on
the pivot pin of the piston 62. The other side of that release arm
74 can then engage against a surface of a flange 76 to rotate the
front latching member 70 into an open configuration, thus releasing
the front pin 68 from the front jaw 54. As the front latch member
70 is sprung into the closed condition as shown in FIG. 2 by a
Roster spring 78, or some other form of biasing means, in the
process of attaching the accessory 34 to the coupler 16, first the
first pin 68 is clicked into the front jaw 54, and then the rear
jaw 56 is lowered onto the second attachment pin 66 before then
powering out the piston 62 from the actuator 60 to draw tight the
pivoting latching hook 58 against the second pin 66.
[0075] Referring next to FIG. 3, a schematic drawing is provided
which shows a simplified arrangement for the coupler control system
of the present invention. As can be seen, a connector 80 is
provided for connecting the coupler control system to a connection
point 96 on the solenoid valve 20. That connector 80 is a part of a
controller 18 of the present invention. The controller 18 is
incorporated with the connector 80 as a single component. FIG. 4 is
similar, but with additional components.
[0076] Power for the controller 18 is provided by the excavator's
battery 48. That battery is also connected to the coupler control
switch 24 to provide the current controlled by the switch 24. The
switch 24 may be retro-fitted into the cab of the excavator, or it
may be an OEM switch provided in the cab during production of the
excavator, the wires for which were thus already present.
[0077] In this embodiment the coupler control switch 24 is a rocker
switch, but it may be a toggle switch or a push button switch or
any other kind of switch as might be desired by a manufacturer. The
switch 24 connects with the controller 18 to allow the controller
to control whether the switch is deactivated or useable to control
the actuator within the coupler.
[0078] As the connector 80 is connected to the solenoid valve 20 of
the excavator, it provides the connection for the switch 24 to the
solenoid valve for the actuator within the coupler.
[0079] In excavators where the solenoid valve is part of an
assembly or manifold that includes sensors for determining
hydraulic pressures in the control lines for the various actuators
60, 42, 38, 44 of the excavator arm 14 and coupler 16, the
controller 18, via the connector 80, can read the pressures of the
boom cylinder 38 direct from the solenoid valve assembly or
manifold 20, to which it is connected.
[0080] A visual indicator 22 is then provided in the rocker switch,
a control line for which follows the line of the connection between
the switch 24 and the controller 18. Alternatively a separate
status indicator can be wired from the controller, as per FIG. 1,
for example.
[0081] With reference to FIG. 4, an alternative arrangement is
shown for where the solenoid valve 20 does not have a pressure
sensor 28 for the boom cylinder's pressure line. This arrangement
is suitable for a retro-fit arrangement as well.
[0082] In this embodiment a battery connection is again provided
between the battery 48 and the controller 18, albeit via a fuse
(which will likely be provided for either embodiment). The
configuration further has the coupler control switch, which may be
new or pre-existing as shown it was pre-existing, and thus
connected to an original solenoid connector 84 albeit with a single
cable connection thereto, the cable having two wires to allow the
power feed from the original solenoid connector, and the switched
return likewise therefrom.
[0083] Also connected to the controller 18 is a pressure switch 28,
which pressure switch 28 is connected to the boom cylinder's
hydraulic circuit elsewhere on the excavator, such as at the base
of the boom arm 36, or the base of the boom cylinder 38, whereat a
separate solenoid valve therefor may be provided.
[0084] Additionally a visual indicator 22 is provided, which can be
on the excavator arm, as per FIG. 1, by way of example. As shown
this is an LED array, although other status indicators can instead
(or additionally) be provided.
[0085] With these two arrangements, the controller 18, via the
pressure switch 28, can determine whether the boom arm cylinder 38
has a pressure below 50 (fifty) barg, signifying that the accessory
34 is at rest on a surface such as the ground 98, whereupon a
counter 94 can determine whether this remains present (or that
pressure substantially constant) for a predetermined period of time
(preferably at least 2 seconds, and more likely at least 3
seconds). The controller will then illuminate the status indicator
22, and enable use of the switch 24. Activation of the switch can
then control the actuator inside the coupler.
[0086] Further preferred operations of the coupler control system
will now be described with reference to FIGS. 5 to 17, where FIGS.
5 to 16 show modes of operation of the excavator and the response
thereto by the coupler control system, whereas FIG. 17 shows a flow
chart of preferred operational control.
[0087] Referring first to FIGS. 5 to 8, there is shown an excavator
12 incorporating either one of the above-mentioned coupler control
systems. In FIG. 5, the excavator arm is lowered into a near (but
not) ground touching condition, with the coupler control switch 24
positioned in a "do-not-operate ram" position. The visual indicator
22 shows no illuminations, signifying a non-operative state of the
switch 24 of the coupler control system 10. In this condition, as
the boom arm 36 carries the weight of itself and the stick, coupler
and accessory, the pressure in the boom cylinders 38 will be above
a predetermined safety pressure, for example the above-mentioned 50
barg.
[0088] FIG. 6 then shows powering of the boom cylinder 30 to lift
(rotate up) the boom arm 36, with the coupler control switch 24
unchanged. The visual indicator 22 is still showing no lights,
whereby it is still indicating the switch 24 of the coupler control
system to be in a deactivated or dormant state.
[0089] FIG. 7 now shows the excavator arm 14 still in an elevated
position but the coupler control switch 24 has now been toggled
into a decouple activation position. The coupler control system,
however, has not identified the low pressure state for the pressure
switch/sensor 28, and thus the switch 24 still remains in its
deactivated/dormant state, as signified by the visual indicator 22
still showing no lights.
[0090] FIG. 8 then shows the boom arm 36 lowered to engage the
coupler 16 to the ground 92, but still the visual indicator 22
shows no lights signifying that the switch 24 of the coupler
control system remains deactivated or dormant. This is a preferred
feature of the present invention, as in this preferred arrangement
the switch of the coupler control system remains deactivated or
dormant if the coupler 16 is placed on the ground when the coupler
control switch is switched to a decouple procedure activate
condition. This is beneficial as it provides safety during use of
the excavator for digging or earth moving processes it can only go
into the decoupling procedure when the switch starts in a
no-decouple position.
[0091] Referring next to FIGS. 9 and 10, FIG. 9 shows the coupler
16 located on the floor so that the boom arm 36 is in a rest
condition and the hydraulic pressure sensed by the pressure sensor
28 will be less than 50 barg. However, shortly after putting down
the bucket 34 on the ground 92, it is lifted again as shown in FIG.
10, whereby the duration of rest on the ground was less than the
prerequisite predetermined time period, e.g. three seconds. As
such, the switch 24 for the coupler control system 10 remains
dormant, as signified by the lack of indication on the visual
indicator 22. This is the case whether the coupler control switch
is in a decouple state or whether it remains in the non-decouple
condition.
[0092] Referring next to FIG. 11, the accessory 34 has again been
placed on the ground 92, but this time for a count meeting the
required predetermined time period, such as at least three seconds
94. As the switch is in the first (non-decouple) condition,
signifying the desire not to commence the decoupling procedure, the
coupler control system allows the visual indicator and the
controller/switch to enter a state of decoupling readiness, as
signified by illumination on the visual indicator 22. In this
embodiment, the indication is an amber illumination as this colour
is widely recognised as being a condition of hazard (in that the
decoupling procedure can now be commenced, which clearly allows the
coupler to release the accessory). However, as the accessory is on
the ground, it is actually a safe condition for release of the
accessory from the coupler.
[0093] In the preferred embodiment, the illumination is more than
one light. Preferably it is a separated illumination, offering a
greater chance of it being seen by the operator.
[0094] Preferably the illumination comprises one or more LEDs, in
this case two clusters of LEDs separated along an illumination
barg. As shown there can be three LEDs in each cluster, although
other arrangements are possible, including illumination of readable
warnings.
[0095] As shown in FIG. 12, however, the boom cylinder 38 is
re-pressurised by the operator to lift the boom arm 36, thus
lifting the accessory 34 off the ground 92. This immediately
deactivates the switch 24 and the coupler control system 10 turns
off the visual indicators 22. The coupler can thus no longer be
operated to release the accessory, keeping the accessory safe,
despite the earlier possibility of releasing it.
[0096] In this situation, the coupler control system 24 remains in
its decouple-prevention condition even if, as shown in FIG. 13, the
switch 24 is then subsequently switched to its decouple activation
position--as the coupler control system 10 has deactivated the
switch 24, no decoupling process occurs.
[0097] Referring next to the sequence of FIGS. 14 to 16, FIG. 14
shows the accessory 34 having been placed on the ground 92 two
seconds earlier--a count of two seconds has thus elapsed, as
shown.
[0098] Furthermore, the coupler control switch 24 is in its first
condition signifying a desire not to decouple, thus allowing the
count towards the predetermined period.
[0099] As the predetermined time period has not yet elapsed, the
visual indicator 22 remains turned off.
[0100] The counting process might be indicated to an operator as
well, via the visual indicator, or another visual indicator, but
that is not shown as in the illustrated embodiment it isn't shown
to the operator.
[0101] FIG. 15 shows the visual indicator 22 after the three
seconds 94 has elapsed and the amber lights return. As shown, the
accessory 34 is still on the ground 92. The coupler control switch
24 has not yet been turned on to activate the decoupling
procedure.
[0102] Referring next to FIG. 16, while the amber lights were
illuminated, and the accessory remained on the ground, the coupler
control switch 24 is now toggled into the activation condition
which turns the visual indicator 22 into its action warning
condition, which in this instance is a full strip of illumination,
preferably in red, to signify that decoupling is now occurring.
This may be a flashing warning or a solid warning. An audio warning
might also be provided.
[0103] In response to that activation, therefore, the warning
lights change and the decoupling procedure commences.
[0104] Preferably the coupler control system automatically performs
a decoupling procedure with the coupler. With preferred couplers,
this is merely an actuation of the actuator within the coupler to
open the two jaws of the coupler.
[0105] While the controller 18 operates the actuator 60 in the
coupler 16, it is preferred that it also freezes operation of the
boom cylinder, the arm cylinder and the bucket cylinder. This then
prevents movement of the accessory 34 during the decoupling
procedure. However, some decoupling procedures may require rotation
of the coupler to release blocking bars. Where the controller
connects to a solenoid valve manifold, and is thus connected to the
control solenoid valves for the excavator arm actuators, the
controller may also operate the additional rotation steps for the
coupler, either by controlling the bucket cylinder 44, or by
operating the bucket cylinder and the arm cylinder 42 and/or the
boom cylinder 38.
[0106] When the coupler actuator 60 has completed its movement,
thus releasing the two attachment pins of the accessory, the
controller 18 may then additionally actuate the bucket cylinder to
rotate the rear jaw of the coupler off the second attachment pin of
the accessory and subsequently the arm cylinder 42 to move the
stick 40 and thus the front jaw so as to remove the coupler from
the accessory.
[0107] These later movements of the excavator arm, however, might
instead be performed by the operator.
[0108] The feature of freezing the arm bucket and boom cylinders is
optional. There may be benefits of leaving them operable by the
operator so that he can counter any movement of the accessory.
Alternatively, for certain couplers he may need to implement a
crowd position for the final actuation of the coupler.
[0109] The coupler control system of the present invention
therefore will only permit actuation of the decoupling procedure
upon sensing a stationary, on ground condition of the accessory by
means of detecting a below predetermined pressure in the boom
cylinder 38, either at the boom cylinder 38 or at the solenoid
valve therefor.
[0110] Furthermore, preferably a decoupling procedure can only
occur when the coupler control switch starts from a do-not-decouple
position. This prevents inadvertent decoupling of the accessory if
it is placed on the floor with the rocker switch in the wrong
position during digging procedures.
[0111] Referring finally to FIG. 17, a flow chart for a preferred
coupler control system 10 is shown. As can be seen, the timer or
counter 32 may be constantly operating or may be selectively
operable by the controller. When the coupler control switch 24 is
on, i.e. in the activate (decouple) position, the timer gets re-set
so the coupling control system and switch is effectively disabled
until the coupler control switch 24 is put into the do-not-decouple
(or first) position.
[0112] Assuming the coupler control switch 24 is in the
do-not-decouple (or first) position, the system next considers
whether the pressure switch or sensor for the boom cylinder
pressure is on (i.e. detecting a pressure above the predetermined
pressure for the given excavator arm). This pressure switch can be
the pressure sensor 28 at the bottom of the boom arm 36, or the
pressure sensor 28 in the controller 18, dependent upon the
excavator being used. In the preferred embodiment it is to
determine whether the boom cylinder hydraulics are under a pressure
exceeding 50 barg (or some other predetermined pressure signifying
a rest or grounded accessory condition).
[0113] As discussed before, different excavator sizes may require
different predetermined pressures--a smaller excavator (with a
smaller excavator arm) might need a 20 or 30 barg limit rather than
a 50 barg limit.
[0114] Other pressures can be pre-set for particular
excavators.
[0115] If the pressure switch or sensor 28 is indicating a pressure
in excess of 50 barg, or the set predetermined pressure, such as by
being turned off, or by being turned on, depending upon its
particular arrangement, once again the time is re-set and the test
reverts to the beginning to check that the coupler control switch
is appropriately set into the do-not-decouple state. However, if
the pressure switch or sensor determines a lower pressure than 50
barg, the counter will count the length of the time that the
pressure stays there, at least up to the predetermined time period
(by default three seconds). During this time, the status indicator
stays off.
[0116] If the three seconds have been counted, the status indicator
then indicates as such, e.g. by the amber light(s) being turned on,
to signify readiness for decoupling.
[0117] A fixed time period after that may then be provided for
moving the coupler control switch 24 into a decouple activation
condition, signifying a choice by the operator to decouple the
accessory.
[0118] If the switch 24 is turned to activate the decoupling
procedure, then the solenoid valve for controlling the actuator 60
in the coupler 34 is turned on, the decoupling warning is given,
such as by the visual indicator turning red, and the amber light
turning off, and the decoupling procedure commences.
[0119] Alternatively, if the coupler control switch 24 is not
turned to the decouple actuation condition, the solenoid valve 20
for the actuator 60 of the coupler 34 stays off and ultimately the
amber light will turn off to return back to looking at the pressure
switch 28, which may then either still be detecting the low
pressure in which case it cycles through again to create a flashing
of the amber light, or the amber light stays off as the pressure
again increases due to the excavator arm being once again in
use.
[0120] Instead of flashing the warning, the warning may stay on
until the excavator arm is in use again.
[0121] A further switch or a further position for the switch may
also be provided for permanently disengaging the coupler control
system until such a time as it wants to be actuated. For this
purpose, a three position switch may be desirable. A separate
switch may instead provide this function.
[0122] The present invention has therefore been described above
purely by way of example. Modifications in detail may be made to
the invention within the scope of the claims appended hereto.
* * * * *