U.S. patent application number 11/610211 was filed with the patent office on 2007-07-12 for coupler with improved jaw configuration.
This patent application is currently assigned to Tower Street Technologies Limited. Invention is credited to Gary Miller, Ronald Keith Miller, Gary Pendleton, Howard Reay.
Application Number | 20070157492 11/610211 |
Document ID | / |
Family ID | 38231375 |
Filed Date | 2007-07-12 |
United States Patent
Application |
20070157492 |
Kind Code |
A1 |
Miller; Ronald Keith ; et
al. |
July 12, 2007 |
Coupler With Improved Jaw Configuration
Abstract
An excavator coupler that is either attached to, or for
attachment to, an excavator arm of a digger for connecting an
attachment, such as a bucket, to the excavator arm of the digger,
the attachment having at least one bucket or coupler pin, wherein
the coupler comprises a jaw for engaging that pin, the jaw
comprising an interior space for the pin, and lips that partially
occlude the interior space so as to provide a profile for the jaw
that has a widened interior relative to either the gap between the
lips or the opening of the jaw, if narrower, one lip being provided
on an upper wall of the jaw and the other lip being provided on a
lower wall of the jaw.
Inventors: |
Miller; Ronald Keith;
(Newcastle Upon Tyne, GB) ; Miller; Gary; (Tyne
& Wear, GB) ; Pendleton; Gary; (Stanley, GB)
; Reay; Howard; (Tyne & Wear, GB) |
Correspondence
Address: |
Stephen B. Salai, Esq.;Harter, Secrest & Emery LLP
1600 Bausch & Lomb Place
Rochester
NY
14604-2711
US
|
Assignee: |
Tower Street Technologies
Limited
|
Family ID: |
38231375 |
Appl. No.: |
11/610211 |
Filed: |
December 13, 2006 |
Current U.S.
Class: |
37/468 |
Current CPC
Class: |
E02F 3/365 20130101;
E02F 3/3686 20130101; E02F 3/36 20130101 |
Class at
Publication: |
037/468 |
International
Class: |
E02F 3/96 20060101
E02F003/96 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 13, 2005 |
GB |
GB 200525379.4 |
Sep 4, 2006 |
GB |
GB 200617394.2 |
Claims
1. An excavator coupler adapted to be attached to an excavator arm
of a digger, and to be connected to an attachment, such as a
bucket, having at least one pin, wherein the coupler comprises: a
front jaw adapted for engaging a pin, the jaw having an opening for
the pin, the opening facing generally longitudinally relative to
the length of the coupler and the jaw comprising an interior space,
and lips that partially occlude the interior space so as to provide
a profile for the jaw that has a widened interior relative to the
narrower of the gap between the lips and the opening of the jaw,
and wherein one lip is provided on an upper wall of the jaw and the
other lip is provided on a lower wall of the jaw.
2. An excavator coupler adapted to be attached to an excavator arm
of a digger, and to be connected to an attachment, such as a
bucket, having at least one pin, wherein the coupler comprises: a
front jaw adapted for engaging a pin, the jaw having an opening for
the pin, the opening facing generally longitudinally relative to
the length of the coupler and the jaw comprising an interior space,
and at least one lip that partially occludes the interior space so
as to provide a profile for the jaw that has a widened interior
relative to the opening of the jaw, the lip being provided on
either an upper wall of the jaw or on a lower wall of the jaw, the
front jaw not being associated with a latching means.
3. An excavator coupler adapted to be attached to an excavator arm
of a digger, and to be connected to an attachment, such as a
bucket, having at least one pin, wherein the coupler comprises: a
front jaw adapted for engaging a pin, the jaw having an opening for
the pin, the opening facing generally longitudinally relative to
the length of the coupler and the jaw comprising an interior space,
and at least one lip that partially occludes the interior space so
as to provide a profile for the jaw that has a widened interior
relative to the jaw's opening, the lip being provided on an upper
wall of the jaw.
4. An excavator coupler adapted to be attached to an excavator arm
of a digger, and to be connected to an attachment, such as a
bucket, having at least one pin, wherein the coupler comprises: a
front jaw adapted for engaging a pin, the jaw having an opening for
the pin, the opening facing generally longitudinally relative to
the length of the coupler and the jaw comprising an interior space,
and at least one lip that partially occludes the interior space so
as to provide a profile for the jaw that has a widened interior
relative to the opening of the jaw, the lip being provided on a
lower wall of the jaw and a gravity operated latching means
associated with the front jaw, the latching means being provided on
an upper wall of the jaw and being arranged to operate under the
influence of gravity such that it will fall under the influence of
gravity from a normal latching position, in which it partially
occludes the interior space, into a non-latching position, upon
inverting the coupler.
5. The coupler of claim 1, wherein the jaw's interior space has an
intermediate portion behind the lips that is widened relative to
the gap defined by the opening and also widened relative to a back
portion of the interior space.
6. The coupler of claim 5, wherein the back portion of the jaw is
radiused in profile.
7. The coupler of claim 1, wherein the front jaw has a solid
construction extending across full width of the coupler.
8. The coupler of claim 1, wherein the front jaw is bifurcated.
9. The coupler of claim 1, wherein the depth dimension of the front
jaw is oriented in a direction that is inclined from parallel to
the longitudinal direction of the coupler.
10. The coupler of claim 1, wherein the coupler is provided with
another jaw which is downwardly facing.
11. The coupler of claim 10, wherein the downwardly facing jaw has
a latching hook or plate associated with it.
12. The coupler of claim 11, wherein the latching hook or plate is
a pivoting latching hook.
13. The coupler of claim 11, additionally comprising a safety pin
or a blocking bar for positioning behind or through the hook or
plate for locking or blocking it.
14. The coupler of claim 10, wherein the downwardly facing jaw is
wider in the longitudinal direction than the depth of the front
jaw.
15. The coupler of claim 1, wherein the profile of an intermediate
portion of the interior space is stepped outwardly relative to both
a back portion of the jaw and the lips.
16. The coupler of claim 1, wherein the profile of an intermediate
portion of the interior space is stepped outwardly relative to both
a back portion of the jaw and a lip of the jaw in both the upper
wall and the lower wall of the jaw.
17. The coupler of claim 1, wherein the profile of an intermediate
portion of the interior space is stepped outwardly from each lip,
but is not stepped outwardly relative to a back portion of the
jaw.
18. The coupler of claim 1, wherein the profile of an intermediate
portion of the interior space is stepped outwardly from a back
portion of the jaw in just one of the upper wall and the lower wall
of the jaw, and also from each lip.
19. The coupler of claim 15, wherein the width of the intermediate
portion, measured in the longitudinal direction of the coupler, is
at least twice the height of the tallest lip of the front jaw.
20. The coupler of claim 1, wherein the tallest lip of the jaw has
a height of between 8 and 20 mm.
21. The coupler of claim 1, comprising no active latch or catch for
the front jaw.
22. The coupler of claim 2, wherein the jaw's interior space has an
intermediate portion behind the lip that is widened relative to the
gap defined by the opening and also widened relative to a back
portion of the interior space.
23. The coupler of claim 2, wherein the coupler is provided with
another jaw which is downwardly facing.
24. The coupler of claim 23, wherein the downwardly facing jaw has
a latching hook or plate associated with it.
25. The coupler of claim 24, additionally comprising a safety pin
or a blockinq bar for lockinq or blockinq the hook or plate.
26. The coupler of claim 23, wherein the downwardly facing jaw is
wider in the longitudinal direction than the depth of the front
jaw.
27. The coupler of claim 2, wherein the profile of an intermediate
portion of the interior space is stepped outwardly relative to both
a back portion of the jaw and the lip.
28. The coupler of claim 2, wherein the lip of the jaw has a height
of between 8 and 20 mm.
29. The coupler of claim 2, comprising no active latch or catch for
the front jaw.
30. The coupler of claim 3, wherein the jaw's interior space has an
intermediate portion behind the lip that is widened relative to the
gap defined by the opening and also widened relative to a back
portion of the interior space.
31. The coupler of claim 3, wherein the coupler is provided with
another jaw which is downwardly facing.
32. The coupler of claim 31, wherein the downwardly facing jaw has
a latching hook or plate associated with it.
33. The coupler of claim 32, additionally comprising a safety pin
or a blocking bar for locking or blocking the hook or plate.
34. The coupler of claim 31, wherein the downwardly facing jaw is
wider in the longitudinal direction than the depth of the front
jaw.
35. The coupler of claim 3, wherein the profile of an intermediate
portion of the interior space is stepped outwardly relative to both
a back portion of the jaw and the lip.
36. The coupler of claim 3, wherein the lip has a height of between
8 and 20 mm.
37. The coupler of claim 4, wherein the jaw's interior space has an
intermediate portion behind the lip that is widened relative to the
gap defined by the opening and also widened relative to a back
portion of the interior space.
38. The coupler of claim 4, wherein the coupler is provided with
another jaw which is downwardly facing.
39. The coupler of claim 38, wherein the downwardly facing jaw has
a latching hook or plate associated with it.
40. The coupler of claim 39, additionally comprising a safety pin
or a blocking bar for locking or blocking the hook or plate.
41. The coupler of claim 38, wherein the downwardly facing jaw is
wider (i.e. longer in the longitudinal direction) than the depth of
the front jaw.
42. The coupler of claim 4, wherein the profile of an intermediate
portion of the interior space is stepped outwardly relative to both
a back portion of the jaw and the lip.
43. The coupler of claim 4, wherein the lip has a height of between
8 and 20 mm.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to GB 0525379.4, filed Dec.
13, 2005 and GB 0617394.2 filed Sep. 4, 2006 and expressly
incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A "SEQUENCE LISTING"
[0003] Not applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates to a jaw of a coupler for
coupling attachments, such as buckets, to the excavator arm of a
digger.
[0006] 2. Description of Related Art
[0007] Attachments used to be, and still sometimes are, attached
directly to the excavator arm of diggers by using bucket (or
coupler) pins, hereinafter called "pins". They extend through holes
both in the end of the excavator arm and in the attachments. The
pins link them together such that they are relatively pivotable by
manipulation of the arm.
[0008] The insertion of those pins through the holes has always
proved to be difficult or inconvenient, especially in view of the
heavy weight of some attachments. This is made worse by the fact
that all of the holes need to be carefully aligned in order for the
pins to be passed through them. To avoid this problem, therefore,
automated or "quick" couplers have been developed. They enable the
operator of the digger to couple the attachment to the excavator
arm from within the cab of the digger--the coupler is already
attached to the arm, usually by two more pins.
[0009] Some quick couplers also allow that coupling to be secured,
i.e. made safe from accidental disengagement. See, for example, the
couplers disclosed in GB2330570 (to Miller UK), GB2359062 (to
Miller UK), EP1318242 (to Geith), GB2332417 (to Redrock
Engineering) and U.S. Pat. No. 6,699,001 (to JRB), all of which
have such a safety feature.
[0010] GB2330570 discloses a coupler in which, in addition to the
two holes for coupling the coupler to the excavator arm, there are
two jaws for fitting onto the bucket pins. One of the jaws is
forward facing (for engaging a first pin of an attachment). The
other jaw is downwardly facing (for dipping down onto a second pin
of the attachment once the first pin is in the forward facing jaw).
A pivoting latching hook is associated with the downwardly facing
jaw. It is for latching the second pin in that downwardly facing
jaw. A blocking bar can then swing into a position behind the hook
to block the hook--the blocking bar prevents the hook from pivoting
backwards (i.e. out of its latched position).
[0011] The coupler disclosed in U.S. Pat. No. 6,699,001 also uses a
blocking bar. However, in place of the pivoting latching hook, a
sliding plate is provided.
[0012] GB2359062 also discloses a coupler having a blocking means.
However, the blocking means in that coupler is instead in the form
of a manual safety pin that is inserted behind the latching hook by
the operator, or his assistant, through the sidewalls of the
coupler.
[0013] The couplers in GB2332417 and EP1318242 instead have a latch
for each jaw. The latches are linked together such that either one
or the other of the latches will remain in a latched position while
the coupler is in use.
[0014] Despite the provision of safety features, an operator might
still use the coupler incorrectly. Therefore it would be desirable
to provide an integral or automatic safety feature for the couplers
whereby the likelihood of an accidental disengagement of an
attachment from the coupler can be further reduced, even where the
coupler is used incorrectly.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0015] These and other features of the present invention will now
be described in more detail with reference to the accompanying
drawings in which:
[0016] FIG. 1 shows a coupler of the present invention fitted onto
an excavator arm of a digger with an attachment--a bucket--attached
thereto;
[0017] FIG. 2 is a perspective view of a preferred coupler of the
present invention (all moving elements have been removed for
clarity);
[0018] FIGS. 3 and 4 are opposite side views of the preferred
coupler of the present invention, again with the internal mechanism
removed;
[0019] FIG. 5 is an end view of the preferred coupler, showing a
one-piece jaw; and
[0020] FIGS. 6 to 10 are sectional views through preferred front
jaw configurations.
BRIEF SUMMARY OF THE INVENTION
[0021] The present invention therefore provides an excavator
coupler having a top either that is attached to, or that is for
attachment to, an excavator arm of a digger, the coupler having a
bottom to which an attachment, such as a bucket, can be, or is,
connected, the attachment having at least one pin, wherein the
coupler comprises a front jaw for engaging that pin, the jaw having
an opening for the pin, the opening facing generally longitudinally
relative to the length of the coupler and the jaw comprising an
interior space, and lips that partially occlude the interior space
so as to provide a profile for the jaw that has a widened interior
relative either to the gap between the lips or to the opening of
the jaw, if narrower, and wherein one lip is provided on an upper
wall of the jaw and the other lip is provided on a lower wall of
the jaw.
[0022] Preferably the jaw's interior space has an intermediate
portion behind the lips that is widened relative to the gap between
the lips and also widened relative to a back portion of the
interior space.
[0023] Preferably the back portion defines a seat for the pin. The
pin can then sit in that seat when the attachment is secured
properly to the coupler.
[0024] Preferably the back portion of the jaw is generally circular
or radiused, i.e., defining a semi-tubular profile. That feature
provides a seat for a round bucket pin of an appropriate size
(which will be fractionally smaller than the radius of the back
portion), whereby the pin can sit firmly or securely within the
back portion of the jaw.
[0025] The radiused portion may comprise a curve with more than one
radius whereby two or more differently sized round pins can sit
firmly or securely within the back portion of the jaw. The two or
more radiused curves may be distinctly formed or might instead be
blended together.
[0026] Preferably the coupler is provided with another jaw which is
downwardly facing, i.e. away from the excavator arm, in use. It is
for receiving a second pin of the attachment.
[0027] Preferably the downwardly facing jaw has a latching hook or
a latching plate associated with it. The hook or plate is for
locking the second pin within the downwardly facing jaw upon
movement or advancement of that latching hook or plate into a
latched position.
[0028] Preferably the front jaw is a solid member that extends
across the full width of the coupler, and preferably with a
substantially constant cross section. However, it may be a
bifurcated jaw, e.g. by being formed by cutting or forming the
jaw's profile into two side plates of the coupler. Additionally or
alternatively, it might have a taper, usually on its bottom half,
e.g. to form (or partially form) a beak or a point. The taper can
ease or facilitate the engagement of the jaw with the first
pin.
[0029] If the coupler is made of a cast body, preferably milling
provides some of the finished surfaces of the coupler. The jaws may
be formed or finished by that milling process, or may be formed by
the casting. However, the jaws may instead be pre-formed as a
separate component, e.g. from a tougher material than the coupler's
main body. The jaw may then be welded or otherwise joined to that
body. That separate fabrication technique for the jaw, however, is
also preferably used when the coupler's main body is made from
plate stock, rather than by a casting technique.
[0030] Preferably the depth dimension of the partially occluded jaw
is oriented in a direction that is inclined from parallel to the
longitudinal direction of the coupler. The depth dimension of the
jaw may, however, be parallel to that longitudinal direction of the
coupler. Most preferably, however, the angle of inclination faces
upwards. The angle may be up to 20.degree. from the parallel
direction, but most preferably it is about 10.degree. from the
parallel direction.
[0031] Preferably the front jaw has a width that is less than the
widest width of the coupler--the width of the front jaw is measured
in a lateral direction of the coupler.
[0032] Preferably the downwardly facing jaw has two longitudinally
spaced end walls. Preferably the gap between the end walls is wider
than the depth of the first jaw--the width of the gap is measured
along the longitudinal direction of the coupler)
[0033] Preferably the gap of the downwardly facing jaw is at least
one and a half times wider than the diameter of a second pin of an
attachment suitable for attaching to the coupler. The width of the
gap might even be two or three times wider than such a pin. This
feature allows the coupler to be used for attaching a wide range of
different attachments to the same excavator arm, the attachments
having a range of different pin spacings, i.e. the spacing between
the pin centers on the attachments).
[0034] Preferably the downwardly facing jaw has a profile that
comprises two sides and a top that extends between the two sides.
The top preferably comprises two concave end portions and a central
convex portion between the two concave end portions. Those portions
may be blended together so as to provide a top for the jaw with a
smooth profile or shape.
[0035] Preferably the convex portion has a radius, the centre of
which lies substantially on the pivoting axis of the hook (when the
coupler has a pivoting latching hook for the downwardly facing
jaw).
[0036] Preferably the two sides are profiled so as partially to
occlude the opening of the downwardly facing jaw. The sides may be
rounded off at that opening, and may also be blended with the
concave end portions of the top of the jaw.
[0037] The lips of the front jaw may extend sharply inward from the
upper and lower walls of the jaw, like teeth. More preferably,
however, the inside wall of each lip has a curve that blends the
upper or lower wall so as to give a smooth profile.
[0038] The tips of the lips may be rounded or squared off.
[0039] Preferably the lips of the front jaw (or each half of it, if
bifurcated) are integrally formed with the rest of the front jaw,
thereby making the jaw a unitary structure.
[0040] The lips provide two dams that can resist movement of the
first pin out of that jaw (i.e. after it has been located into the
jaw by passing it through the opening (i.e. through the gap between
the lips).
[0041] Prior art front jaws usually have no lips, or no more than a
small ridge. As a result, in prior art front jaws, a pin would
normally be free to fall out of the jaw if it was allowed to slide
in the jaw (i.e. if it was not secured into the back of the jaw by
the engagement of the latching hook (or plate) against the other
pin). The dams of the present invention prevent that freedom to
fall out of the jaw.
[0042] It is noted, however, that FIG. 1 of GB2332417 shows a front
jaw having a lip on its bottom wall. That coupler, however, also
requires a latch for closing that jaw. The present invention
therefore also provides: an excavator coupler having a top either
that is attached to, or that is for attachment to, an excavator arm
of a digger, the coupler having a bottom to which an attachment,
such as a bucket, can be, or is, connected, the attachment having
at least one pin, wherein the coupler comprises a front jaw for
engaging that pin, the jaw having an opening for the pin, the
opening facing generally longitudinally relative to the length of
the coupler and the jaw comprising an interior space, and at least
one lip that partially occludes the interior space so as to provide
a profile for the jaw that has a widened interior relative to the
opening of the jaw, the lip being provided on either an upper wall
of the jaw or on a lower wall of the jaw, the front jaw not being
associated with a latching means.
[0043] The present invention also provides: an excavator coupler
having a top either that is attached to, or that is for attachment
to, an excavator arm of a digger, the coupler having a bottom to
which an attachment, such as a bucket, can be, or is, connected,
the attachment having at least one pin, wherein the coupler
comprises a front jaw for engaging that pin, the jaw having an
opening for the pin, the opening facing generally longitudinally
relative to the length of the coupler and the jaw comprising an
interior space, and at least one lip that partially occludes the
interior space so as to provide a profile for the jaw that has a
widened interior relative to the opening of the jaw, the lip being
provided on a lower wall of the jaw and the front jaw being
associated with a gravity operated latching means, that latching
means being provided on an upper wall of the jaw and being arranged
to operate under the influence of gravity such that it will fall
under the influence of gravity from a normal latching position, in
which it partially occludes the interior space, into a non-latching
position, upon inverting the coupler.
[0044] Preferably, in the non-latching position, the latching means
retracts fully from the opening of the jaw such that it no longer
occludes the interior space.
[0045] Preferably the profile of the intermediate portion of the
interior space is stepped outwardly relative to both the back
portion and or each lip, and more preferably both in the upper and
lower walls of the jaw. The intermediate portion may, however, be
stepped outwardly only from the or each lip, or from the or each
lip and just one of the upper wall or the lower wall of the back
portion.
[0046] The height of the or each lip is preferably between 8 and 20
mm, and more preferably between 10 and 17 mm. Preferably the height
of the or each lip is between one eighth and one third of the
diameter of the pin for which the jaw was designed (or higher), or
between one eighth and one third of the height of the opening of
the jaw (or higher) or between one eighth and one third of the
height (or diameter) of the back portion of the jaw. Most
preferably, however, it is about one quarter of the diameter of the
pin for which the jaw was designed, or about one quarter of the
height of the opening of the jaw or about one quarter of the height
(or diameter) of the back portion of the jaw.
[0047] Preferably, if a line was to extend across the opening of
the jaw, that line would extend substantially perpendicularly
between the top and the bottom of the coupler. More preferably,
however, the lower half of the jaw projects further outward than
the upper half of the jaw, whereby that line would be angled by
10.degree., or more, from that perpendicular. Then, where two lips
are provided, a pin jumping around in the jaw (i.e. when the
attachment and coupler are inverted such that the attachment is on
top of the coupler, e.g. when the excavator arm and the attachment
are in the crowd position) would not readily jump from behind the
lip in the upper wall (i.e. the one that is now lowermost due to
the inversion) to a position on top of the opposite lip, but
instead would jump to a position behind that opposite lip. This
makes the pin even less likely to jump out of the jaw. It should be
appreciated, however, that that jumping problem does not occur with
the coupler and attachment oriented the normal way up (i.e. with
the attachment below the coupler). That is because the weight of
the attachment will keep the pin behind the bottom lip.
[0048] Preferably, the intermediate portion having the widened
dimension is defined by cut-outs in either or both of the upper and
lower walls of the jaw. The cut-outs extend across the full width
of the jaw (i.e. laterally across the coupler). The lips and the
back portion are then the parts of the jaw that lie forward and
rearward, respectively, of those cut-outs.
[0049] Preferably the intermediate portion is defined by a cut-out
having a depth and a width, the width (measured longitudinally
relative to the coupler) being at least twice the depth. More
preferably, the width is more than three times the depth, and most
preferably the width is more than four times the depth. This
arrangement is to allow the pin to fall full depth into the
cut-out, rather than being prevented from doing so because the
cut-out is too narrow.
[0050] Preferably the cut-out is between 8 and 20 mm deep (whereby
a lip height of between 8 and 20 mm is provided). More preferably,
the cut-out is between 12 and 17 mm deep.
[0051] Preferably the cut-out is between 40 and 80 mm long. More
preferably the cut-out is between 46 and 72 mm long.
[0052] The present invention also provides an excavator coupler
having a top either that is attached to, or that is for attachment
to, an excavator arm of a digger, the coupler having a bottom to
which an attachment, such as a bucket, can be, or is, connected,
the attachment having at least one pin, wherein the coupler
comprises a front jaw for engaging that pin, the jaw having an
opening for the pin, the opening facing generally longitudinally
relative to the length of the coupler and the jaw comprising an
interior space, and at least one lip that partially occludes the
interior space so as to provide a profile for the jaw that has a
widened interior relative to the jaw's opening, the lip being
provided on an upper wall of the jaw.
[0053] Preferably no moving latch or catch is provided for the
front jaw.
[0054] Preferably the downwardly facing jaw is associated with a
latch or catch. That latch or catch is preferably a pivoting
latching hook, although it might instead slide between its open and
closed positions.
[0055] A safety pin or a blocking bar might be provided for the
latch or catch.
[0056] The present invention also provides a combination of an
attachment (such as a bucket) and a coupler, the coupler having a
front jaw and the attachment having a pin for engagement with the
front jaw, the front jaw having a front opening extending generally
in the longitudinal direction of the coupler relative to the length
of the coupler, the jaw having an upper wall with a cut-out therein
defining a back portion rearward thereof and a lip forward
thereof.
[0057] In each embodiment of the present invention, the opening
should face no more than 20.degree. from that longitudinal
direction of the coupler, but more preferably no more than
15.degree. from that longitudinal direction of the coupler. The
longitudinal direction extended between the front and rear ends of
the coupler, i.e. generally parallel to the top, the bottom and the
sides of the coupler.
[0058] Couplers, both of the prior art and of the present
invention, usually have a side plate that is positioned nearer the
top of the coupler than the jaw, which side plate lies in a plane
that is laterally stepped outwardly from the side of the coupler's
front jaw. That step-out defines a step-face that faces downwardly,
i.e. towards the two jaw. It is preferred that the couplers of the
invention similarly have such a step-face.
[0059] In conventional attachments, e.g. buckets, the front pin,
i.e. the pin for the front jaw of a coupler, is mounted
substantially perpendicularly between two plates. Each plate has an
upper surface (or is capped by something having an upper surface).
In use that upper surface faces the step-face. Preferably,
therefore, in accordance with another aspect of the present
invention there is provided a combination comprising a coupler of
the present invention (as defined above) having both a front jaw
and a step-face and an attachment having both a upper surface and a
front pin for engagement in the front jaw, wherein the upper
surface, in use, faces the step-face, and wherein the front jaw of
the coupler is spaced sufficiently downward from the step-face to
allow the upper surface of the attachment, in use, to be spaced
from the step-face both when the front jaw and the pin are properly
seated together, and when the pin is sitting behind the lip in the
upper wall, perhaps in a cut-out that defines that lip. This stops
any rubbing occurring between the coupler and the attachment, and
will prevent the engagement of the upper surface with the step-face
from preventing the pin from falling into the cut-out, or from
falling behind the lip.
DETAILED DESCRIPTION OF THE INVENTION
[0060] Referring first of all to FIG. 1, the excavator digger 10
has a rear excavator arm 12. The arm 12 has a coupler 14 of the
present invention attached thereto by way of pins, as known in the
art. The coupler 14 attaches a bucket 16 to the excavator arm 12 of
the digger 10 again by way of pins, as known in the art. The
excavator arm 12, the bucket 16 and the digger 10 are all shown in
dotted lines since only the coupler is of interest in the present
case.
[0061] Instead of a bucket 16, some alternative excavator
attachment might be secured to the excavator arm 12 of the digger
10 by the coupler 14.
[0062] As shown in FIGS. 2 to 5, the coupler 14 comprises a top
portion 18, a bottom portion 20, and two ends 22, 24. In normal
use, the front end 24 is the one that is shown to the right in FIG.
3 and the rear end 22 is the one that is shown to the left in FIG.
3. The front end 24 is therefore the end that would usually point
towards the digger when the digger operator is attempting to couple
an attachment to the coupler. By this arrangement, the operator can
see the front end so as to assist that coupling operation--that
front end will need to be brought into alignment with the
attachment during a first step of the coupling operation.
[0063] The top portion 18 comprises two pairs of holes 26 for
attaching the coupler 14 to the excavator arm 12 by using pins, as
shown in FIG. 1. The bottom portion 20, however, has two jaws 28,
30. Those jaws are also for engaging pins, but this time they are
pins 32 of the bucket 16 (see FIG. 1).
[0064] The first jaw 28 faces downwardly. It is called the
downwardly facing jaw 28. The second jaw 30 faces longitudinally
out of the front end 24 of the coupler 14. It is called the front
jaw 30.
[0065] The coupler is also provided with a lifting eye 36, which
can be used to attach things to the coupler for example with a rope
or a chain.
[0066] Although not shown, the first jaw 28 is associated with a
pivoting latching hook, as in GB2330570. It will be appreciated,
however, that a sliding plate or sliding hook might be substituted
for the pivoting latching hook, as in U.S. Pat. No. 6,699,001.
[0067] The latching hook pivots about a pivot hole 34 on a rod (not
shown), and its operation is known from GB2330570. A detailed
discussion of the operation of that latching hook is therefore not
required in this application.
[0068] The second, or front jaw 30 faces towards the front end 24
of the coupler 14 (almost parallel to the longitudinal dimension of
the coupler--it is inclined at an angle of just 10.degree. in the
illustrated embodiments). It opens at that end 24 at an opening, as
shown in FIG. 5.
[0069] The opening of the jaw is partially occluded by both a top
lip 38 and a bottom lip 40. Further, those lips 38, 40 extend
across a significant part of the width of the coupler 14. In an
alternative embodiment, however, the lips 38, 40 may be
intermittent across the width of the coupler, like spaced-apart
teeth.
[0070] The jaw is made as a solid one piece jaw of a toughened
steel. The body is made by casting. The jaw is then welded into
that cast body. That construction might be replaced, however, with
an additional number of components that are welded together. For
example, there might be a bifurcated jaw formed from two
appropriately shaped side plates that are welded onto a frame, the
side plates having two matching jaws cut into them. The lips then
might extend just across the widths of those sidewalls.
[0071] The lips provide the jaw with a new profile, when compared
to the front jaw in GB2330570.
[0072] The profile of the jaw includes the lips 38, 40, a
substantially semi-circular back portion 42 and an intermediate
portion 44. The lips 38, 40 have opposing flat faces that are
parallel to each other, whereby there is a constant gap between
them. The opposing faces might instead be rounded, however.
[0073] The gap between the top and bottom lips 38, 40 of the jaw 30
defines the diameter of the back portion 42 of the jaw 30.
[0074] Between the lips 38, 40 and the back portion 42 there is the
intermediate portion 44. The intermediate portion 44 is widened
relative to them both. This makes the lips 38, 40 partially occlude
the interior space defined by the back portion and the intermediate
portion.
[0075] The intermediate portion is both widened relative to the
dimension of the gap between the lips and widened relative to the
diameter of the back portion of the jaw 30. It might, however, only
be widened relative to the gap between the lips--the back portion
would then not be distinct from the intermediate portion.
Nevertheless, in the illustrated embodiment, the intermediate
portion 44 is widened relative to the back portion and the lips by
two stepped out portions (or cut-outs). One is in the upper wall 46
of the jaw. The other is in the lower wall 48 of the jaw 30. Those
cut-outs each comprises an angled step 50 (the two steps are
substantially opposite each other, although the step 50 in the
lower wall 48 is slightly further forward than the step 50 in the
upper wall 46). The step 50 (more clearly seen in FIG. 9, which
shows the jaw's preferred dimensions for a pin having a diameter of
80 mm) diverges from the back portion 42 to a flat wall section 52.
Then that flat wall section 52 extends forward up to the lip, with
a rounded or blended section 54 joining that flat wall section 52
to the lip.
[0076] The transitions between the back portion 42, the angled
steps 50, the flat wall sections 52, the rounded or blended section
54 and the lips 38, 40 can be sharp. However, they are more
preferably blended so as to avoid stress concentrations. The
backsides of the lips 38, 40, however, have a straight section
after the blended section 54. The straight section butts up to the
flattened tips of the lips, which flattened lips define the
opening. That transition may also be rounded, as can the opening.
Indeed, the tips of the lips can be rounded.
[0077] As discussed above, a lip is provided for the lower wall of
the front jaw of the coupler shown in FIG. 1 of GB2332417. That
jaw, however, does not have a cut-out that defines a back portion
for its jaw. The present invention is additionally differentiated
from that prior art coupler's front jaw by having a lip also on the
upper wall 46 of the jaw 30. Yet further, the preferred embodiments
of the present invention do not have a moving closing mechanism
(e.g. a catch or a hook) for the front jaw. The front jaw in
GB2332417, however, does require a moving closing mechanism.
[0078] In alternative embodiments of the present invention, only a
single cut-out might be provided, either in the upper wall or in
the lower wall, or the transitions between the various parts of the
jaw might be more or less blended than that illustrated, or the
back portion 42 might be wider or narrower than the gap between the
lips, or even the intermediate portion 44 may be either more or
less pronounced (i.e. more or less widened relative to either the
lips or the back portion or both of them).
[0079] The jaw configuration of the present invention, in use,
enables a pin to retain its location within the front jaw 30 even
in the event that the latching hook provided for the other jaw
(i.e. the downwardly facing jaw 28) is inadvertently withdrawn from
a latched position to an open or unlatched position, whereby the
pin would normally have been free to fall out of the front jaw
since the longitudinal position of the pin was no longer restrained
by that hook. There are two scenarios where that inadvertent
decoupling might have happened:
[0080] 1. If the coupler is in its upright position, i.e. above the
bucket, the pin in the downward facing jaw would be free to swing
out of that downwardly facing jaw if the coupler was to be lifted
by rotation of the bucket about the pin in the front jaw. Once
swinging freely (i.e. once the bucket is also lifted, only the
front jaw would be holding the weight of the bucket, via the pin in
that front jaw. Naturally, while the pin remains in the back
portion of the front jaw, the bucket will be carried. However, if
the front jaw was to be pointed downwardly by rotating the coupler,
then the pin in that front jaw would be likely to slide out of that
back portion. Without the lip, the pin would then fall out of the
coupler. The lip of the present invention, however, catches the pin
before it falls out, thereby preventing the pin from failing out.
That lower lip, in other words, forms a dam over which the bucket
pin is unlikely to be able to pass without violent shaking or
careful manipulation of the excavator arm.
[0081] 2. If the coupler was the other way up, i.e. in the "crowd"
position, then it is the other lip that forms the dam. However, in
that orientation, the pin in the "downwardly facing" jaw (i.e. the
one now pointing upwardly since the coupler is inverted) will not
try to disengage from that jaw as readily anyway since the weight
of the bucket holds the pin in that jaw, which in turn restricts
the amount of sliding available to the pins to, at most, the free
width of that downwardly facing jaw. Unfortunately, however, that
free width can be sufficiently long in couplers designed to fit to
attachments having a very wide range of pin spacings to allow
disengagement of the front pin from the front jaw. The dam,
therefore, again serves to prevent that disengagement. The lip in
that upper wall, therefore, is of particular benefit for universal
couplers, i.e. couplers designed to fit attachments having a wide
range of different pin centre spacings.
[0082] The lips also provide the advantage that no latching means
(or other moving part) for the front jaw is needed in order to
resist the disengagement of a pin from that front jaw in the event
of an inadvertent disengagement of the latching hook for the
downwardly facing jaw. The jaw, therefore, provides an inherent
safety feature, i.e. one involving no moving parts that can
fail.
[0083] Referring now to FIGS. 6, 7, 8 and 9, various preferred
front jaw dimensions are provided.
[0084] The jaw in FIG. 6 is a preferred jaw for a pin of 80 mm
diameter. It has a dual radiused back portion--40.1 mm and 35.1 mm.
It will therefore seat either a 80 mm pin or a 70 mm pin. It has
symmetrical cut-outs, each being 70 mm wide and 17 mm deep. The
ramp 50 is rounded rather than straight, unlike that of FIG. 9, and
the blended section 54 mirrors the shape of that ramp 50.
[0085] The two cut-outs will both allow a 80 mm pin to fall into
them to a depth that is about one quarter of the diameter of the
pin (actually 17/80 of the diameter). The jaw is also angled upward
from the longitudinal direction of the coupler by 10.degree..
[0086] The jaw in FIG. 7 is a preferred jaw for a pin of 65 mm
diameter. It also has a dual radiused back portion--32.6 mm and
30.1 mm. It will therefore seat either a 65 mm pin or a 60 mm pin.
It also has the symmetrical cut-outs, like the jaw in FIG. 6. The
cut-outs are 60 mm wide and 17 mm deep. The cut-outs will therefore
allow a 65 mm pin to fall into them to a depth that is about one
quarter of the diameter of the pin (actually 17/65 of the
diameter). The jaw is also angled upward from the longitudinal
direction of the coupler by 10.degree.,
[0087] The jaw in FIG. 8 is a preferred jaw for a pin of 50 mm
diameter. It also has a dual radiused back portion--25.1 mm and
22.6 mm. It will therefore seat either a 50 mm pin or a 45 mm pin.
It also has the symmetrical cut-outs, like FIGS. 6 and 7, however,
the ramp 50 and the blended section 54 is even more rounded. The
cut-outs are both 46 mm wide and 12 mm deep. The cut-outs will
therefore allow a 50 mm pin to fall into them to a depth that is
about one quarter of the diameter of the pin (actually 12/50 of the
diameter). The jaw is also angled upward from the longitudinal
direction of the coupler by 10.degree..
[0088] Then there is the jaw of FIG. 9. It is an alternative, but
still preferred jaw for a pin of 80 mm diameter. It does not have a
dual radiused back portion. The back portion has a fixed radius of
40.1 mm. The 80 mm pin will therefore seat very securely in the
back portion. As such, the coupler will be able to endure a higher
loadings. The cut-outs are not symmetrical since 1. the ramp 50 and
the blended section 54 do not match and 2. Since they are not
opposite each other. Further, their shapes are not mirrored on each
other. One is 20 mm deep (in the lower wall) and the other is 17 mm
deep (in the upper wall. Additionally, the lower one is 74 mm long,
whereas the upper one is 72 mm long. The lower lip 40 will
therefore provide a more resistant dam for the pin than the upper
lip 38. Nevertheless the pin does still fall into them to a depth
that is about one quarter of the diameter of the pin.
[0089] As with the other jaws, this jaw is also angled upward from
the longitudinal direction of the coupler by 10.degree..
[0090] Referring finally to FIG. 10, one final embodiment is
disclosed. This front jaw 30 has another jaw configuration. It has
a single lip 40, extending up from the lower wall 61 of the jaw 30.
However, it also has additional features. Firstly there is a
gravity-operated latching means or member 60. That gravity-operated
member 60 is a toggle in the upper wall 63 of the front jaw 30.
Secondly the lower wall 61 projects further forwards compared to
the upper wall, which widens the opening 31 of the jaw. This second
feature might not be required, however, for example if small
diameter attachment pins are used.
[0091] The toggle is a feature provided in the couplers disclosed
in GB0617394.4, the full contents of which are incorporated herein
by way of reference, and from which this case claims the benefit of
priority.
[0092] As disclosed therein the toggle 60 is mounted within a hole
64 in the upper wall 63 and is mounted for rotation about a pivot
axis, as defined by a peg or bolt 66 that passes through the hole
64 in a transverse direction (i.e. transverse to the sides of the
coupler). The bolt may be held in position by a bolt head and a
nut.
[0093] The toggle 60 may pivot about the bolt 66 between an open or
non-latching position in which the toggle 60 sits fully within the
hole 34, i.e. so as not to partially occlude the opening 31 of the
front jaw 30, and a closed or latching position, as shown in FIG.
4, in which part of the toggle (the part surrounding the bolt)
still sits within the hole 64, but in which the other end 62 of the
toggle 60 extends out of the hole 64 to partially close or occlude
the opening 31 of the jaw 24.
[0094] That toggle is mounted off-center relative to the bolt 36,
whereby it is balanced so that in a normal orientation of the
coupler 10, i.e. in an in-use orientation in which the front and
rear jaws (and therefore also any attachment pins held therein) are
generally level to each other, the toggle's center of gravity will
cause it to rotate under the influence of gravity into that latter
closed position in which the nose or end 62 descends into the front
jaw so as to partially close the opening 31 of the front jaw
24.
[0095] By having this arrangement, in normal use an attachment pin
within that front jaw will only be able to be removed from the
front jaw through the opening 31 of the jaw if the toggle was to
rotate out of its way. That is because attachment pins have a size
corresponding generally to the height of the front jaw. However,
further rotation of that toggle is not possible due to the
configuration of the toggle, the bolt and the hole. The toggle in
its closed position has a wall 78 that bears against a front wall
member 72 of the hole 64. Further, preferably that front wall
member 72, the bolt 66 and the toggle 60 are all reinforced,
toughened or hardened as well, whereby they should be able to
resist even a significant attempt to force an attachment pin out of
the jaw.
[0096] The toggle 60 preferably comprises at its first end
(surrounding the bolt) two perpendicular walls 74, 78 that
tangentially extend from a curved section 76. There is also a third
wall 79 that extends parallel to and perpendicular to the two other
walls 74, 78, respectively. Further, that first end has an aperture
therein through which the bolt 66 passes for pivotally mounting the
toggle 60 within the hole 64 of the front jaw 30. The aperture is
between the two parallel walls 78, 79 and runs parallel to all
three walls 74, 78, 79.
[0097] The hole 64 in the upper wall 63 of the front jaw 30 has a
flat bottom 81 and the inside surface of the front wall member 72
extends perpendicular to that flat bottom 81. That inside surface
also is flat.
[0098] The bolt 66 is arranged through the hole 64 of the first jaw
30 in a position that is spaced from, yet parallel to, both the
flat bottom 81 and the inside surface of the front wall member 72.
The distance of the bolt 66 from the inside surface is slightly
greater than the radius of the curved section 76 of the toggle. The
distance of the bolt 66 from the flat bottom is greater than its
distance from the inside surface.
[0099] The aperture in the toggle is arranged concentrically to the
curved section 76 of the toggle. As a result, the toggle will be
free to rotate within the hole 64 through a full 90.degree. range
of angles, i.e. between its open and closed positions. In the open
position, the first of the two perpendicular walls 74, 78 will bear
against the front wall 72 to provide a first rotation limitation
for the toggle. In the closed position, the second of the two
perpendicular walls 74, 78 will bear against the front wall 72 to
provide a second rotation limitation for the toggle. Changing the
angle between these two perpendicular walls 74, 78 will therefore
change the available range of angles of rotation for the
toggle.
[0100] In addition, the toggle comprises the opposite end 62--the
end 62 that extends out of the hole 64 when the gravity-operated
member 60 is in its closed position. That end 62 comprises a curved
wall 90 that will face towards an attachment pin when one is within
the front jaw and when the member 60 is in its closed position.
That curved surface, although optional, provides an increased area
of surface contact between the attachment pin and the toggle in the
event of an attempt to remove the attachment pin from the front jaw
through the opening of the jaw when the member is in its closed
position. As a result, forces are less concentrated on the
toggle.
[0101] No biasing member is provided for the toggle, whereby it
relies purely upon gravity for its orientation. However, as a
result it is free to rotate within that 90.degree. range if it is
acted upon by an external force. Accordingly, although the toggle
will prevent the withdrawal of an attachment pin from the front
jaw, the toggle will rotate to allow an attachment pin to be
inserted into the jaw.
[0102] By positioning the aperture for the bolt in the first end of
the toggle, the centre of gravity of the toggle is arranged towards
the second end of the toggle relative to its pivot axis. Thus the
gravity-operated member will default to a closed position whenever
the coupler is level. However, the toggle can be moved to its open
or non-latching position by rotating the coupler through an angle
of about 90.degree., i.e. into the crowd position.
[0103] The present invention has been described above purely by way
of example. However, modification in detail to the present
invention may be made within the scope of the invention as defined
in the claims appended hereto.
* * * * *