U.S. patent application number 15/129027 was filed with the patent office on 2017-04-20 for a coupler for a wheel loader.
This patent application is currently assigned to VOLVO CONSTRUCTION EQUIPMENT AB. The applicant listed for this patent is VOLVO CONSTRUCTION EQUIPMENT AB. Invention is credited to Yonghui DONG.
Application Number | 20170107684 15/129027 |
Document ID | / |
Family ID | 54193911 |
Filed Date | 2017-04-20 |
United States Patent
Application |
20170107684 |
Kind Code |
A1 |
DONG; Yonghui |
April 20, 2017 |
A COUPLER FOR A WHEEL LOADER
Abstract
A coupler for a wheel loader is used for coupling an attachment
(102) to a lifting arm of the wheel loader. A bracket (100) is
installed between the lifting arm and the attachment (102). The
bracket's back face is pivotally connected to a lifting arm and the
bracket's front face is detachably connected to the attachment
(102). The attachment (102) has a pair of protrusions (104a,104b)
rearwardly extending from the lower back of the attachment (102)
and have locking holes pierced through their width. The bracket has
a pair of receiving slots (108a,108b) formed at the lower front of
the bracket and engaged with the protrusions(104a,104b). The
coupler has a shaft (202), and a pair of locking pins (204a,204b)
combined with the shaft by threads (216a,216b). The threads
(216a,216b) formed at one end of the shaft (202) are right handed
and the threads (216a,216b) formed at the other end of the shaft
(202) are left handed. When users turn the shaft (202) in one
direction,the locking pins (204a,204b) are extended and engaged
with the locking holes (a coupling position). When users turn the
shaft in the other direction,the locking pins are shortened and
released from the locking holes (a release position).
Inventors: |
DONG; Yonghui; (Jinan,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VOLVO CONSTRUCTION EQUIPMENT AB |
Eskilstuna |
|
SE |
|
|
Assignee: |
VOLVO CONSTRUCTION EQUIPMENT
AB
Eskilstuna
SE
VOLVO CONSTRUCTION EQUIPMENT AB
Eskilstuna
SE
|
Family ID: |
54193911 |
Appl. No.: |
15/129027 |
Filed: |
March 27, 2014 |
PCT Filed: |
March 27, 2014 |
PCT NO: |
PCT/CN2014/074212 |
371 Date: |
September 26, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02F 3/3631 20130101;
E02F 3/3609 20130101; E02F 3/3636 20130101; E02F 3/3672 20130101;
E02F 3/3668 20130101 |
International
Class: |
E02F 3/36 20060101
E02F003/36 |
Claims
1. A coupler for detachably connecting an attachment to the free
end of a lifting arm on a wheel loader, comprising: a bracket with
a back face pivotally connected to said lifting arm and a front
face detachably connected with said attachment; a first and a
second protrusions rearwardly extending from the lower back of said
attachment and laterally spaced apart from each other, said first
protrusion having a first locking hole pierced through its width
and said second protrusion having a second locking hole pierced
through its width; a first and a second receiving slots formed at
the lower front of said bracket and engaged with said first
protrusion and said second protrusion, respectively; a shaft which
has threads formed at both ends and installed at the lower part of
said bracket, wherein the threads formed at the one end of said
shaft are right handed and the threads formed at the other end of
said shaft are left handed; a first locking pin which has threads
corresponding to the threads formed at the one end of said shaft; a
second locking pin which has threads corresponding to the threads
formed at the other end of said shaft; a first holder fixed to said
bracket and supporting said first locking pin so as to prevent said
first locking pin from being rotated when said shaft is driven to
rotate, thereby enabling a rectilinear movement of said first
locking pin and disabling a rotational movement of said first
locking pin; a second holder fixed to said bracket and supporting
said second locking pin so as to prevent said second locking pin
from being rotated when said shaft is driven to rotate, thereby
enabling a rectilinear movement of said second locking pin and
disabling a rotational movement of said second locking pin; and
wherein said coupler has a coupling position of the attachment in
which said locking pins are extended and engaged with said locking
holes of said protrusions as said shaft rotates in one direction,
and a release position of the attachment in which said locking pins
are shortened and released from said locking holes of said
protrusions as said shaft rotates in the other direction.
2. The coupler of claim 1, wherein: said first locking pin is
longitudinally divided into a cylindrically cross-sectioned outer
part and a non-cylindrically cross-sectioned inner part, said outer
part being subject to be engaged with said first locking hole; said
second locking pin is longitudinally divided into a cylindrically
cross-sectioned outer part and a non-cylindrically cross-sectioned
inner part, said outer part being subject to be engaged with said
second locking hole; said first holder has a contacting surface
corresponding to the non-cylindrical contour of said inner part of
said first locking pin; and said second holder has a contacting
surface corresponding to the non-cylindrical contour of said inner
part of said second locking pin.
3. The coupler of claim 2, wherein: the cross-section of said inner
part of said first locking pin is partially flattened cylindrical
shape; and the cross-section of said inner part of said second
locking pin is partially flattened cylindrical shape.
4. The coupler of claim 2, wherein: the cross-section of said inner
part of said first locking pin is polygonal shape; and the
cross-section of said inner part of said second locking pin is
polygonal shape.
5. The coupler of claim 2, wherein: the longitudinal length of said
inner part of said first locking pin is longer than or at least
equal to the rectilinear moving stroke of said first locking pin
along said shaft; and the longitudinal length of said inner part of
said second locking pin is longer than or at least equal to the
rectilinear moving stroke of said second locking pin along said
shaft.
6. The coupler of claim 1, wherein: said first locking pin is
tubular and said threads of said first tubular locking pin are
formed at the internal surface of said first tubular locking pin;
and said second locking pin is tubular and said threads of said
second tubular locking pin are formed at the internal surface of
said second tubular locking pin.
7. The coupler of claim 1, wherein: said threads formed at said
shafts and said locking pins are multi start threads, whereby the
lead per rotation is increased.
8. The coupler of claim 6, wherein: said threads formed at said
shafts and said locking pins are multi start threads, whereby the
lead per rotation is increased.
9. The coupler of claim 1, wherein said shaft further comprising: a
driving section with a polygonal cross-section.
10. The coupler of claim 1, further comprising: a fixture wrapping
around said shaft and fixed to said bracket at its edges.
11. The coupler of claim 9, further comprising: a first fixture
wrapping around said shaft at the right side of said driving
section and fixed to said bracket at its edges; and a second
fixture wrapping around said shaft at the left side of said driving
section and fixed to said bracket at its edges.
12. The coupler of claim 1, wherein: said first receiving slot has
an outer wall with a first aperture receiving and securing the end
of said first locking pin in the coupling position of the
attachment; and said second receiving slot has an outer wall with a
second aperture receiving and securing the end of said second
locking pin in the coupling position of the attachment.
13. The coupler of claim 1, wherein: said first receiving slot has
an outer wall with a first indentation receiving and securing the
end of said first locking pin in the coupling position of the
attachment; and said second receiving slot has an outer wall with a
second indentation receiving and securing the end of said second
locking pin in the coupling position of the attachment.
14. A coupler for detachably connecting an attachment to the free
end of a lifting arm on a wheel loader, comprising: a bracket with
a back face pivotally connected to said lifting arm and a front
face detachably connected with said attachment; a first and a
second protrusions rearwardly extending from the lower back of said
attachment and laterally spaced apart from each other, said first
protrusion having a first locking hole pierced through its width
and said second protrusion having a second locking hole pierced
through its width; a first and a second receiving slots formed at
the lower front of said bracket and engaged with said first
protrusion and said second protrusion, respectively; a shaft which
has threads formed at both ends and installed at the lower part of
said bracket, wherein the threads formed at the one end of said
shaft are right handed and the threads formed at the other end of
said shaft are left handed; a first locking pin which has threads
corresponding to the threads formed at the one end of said shaft, a
cross-section of said first locking pin being partially
non-cylindrical shape, a contacting surface of said first locking
hole with said first locking pin corresponding to said
non-cylindrical contour of said first locking pin; a second locking
pin which has threads corresponding to the threads formed at the
other end of said shaft, a cross-section of said second locking pin
being partially non-cylindrical shape, a contacting surface of said
second locking hole with said second locking pin corresponding to
said non-cylindrical contour of said second locking pin; and
wherein said coupler has a coupling position of the attachment in
which said locking pins are extended and engaged with said locking
holes of said protrusions as said shaft rotates in one direction,
and a release position of the attachment in which said locking pins
are shortened and released from said locking holes of said
protrusions as said shaft rotates in the other direction.
15. The coupler of claim 14, wherein: the cross-section of said
first locking pin is partially flattened cylindrical shape; and the
cross-section of said second locking pin is partially flattened
cylindrical shape.
16. The coupler of claim 14, wherein: the cross-section of said
first locking pin is polygonal shape; and the cross-section of said
second locking pin is polygonal shape.
17. The coupler of claim 14, wherein: said first locking pin is
tubular and said threads of said first tubular locking pin are
formed at the internal surface of said first tubular locking pin;
and said second locking pin is tubular and said threads of said
second tubular locking pin are formed at the internal surface of
said second tubular locking pin.
18. The coupler of claim 14, wherein: said threads formed at said
shafts and said locking pins are multi start threads, whereby the
lead per rotation is increased.
19. The coupler of claim 14, wherein said shaft further comprising:
a driving section with a polygonal cross-section.
20. The coupler of claim 14, further comprising: a fixture wrapping
around said shaft and fixed to said bracket at its edges.
21. The coupler of claim 19, further comprising: a first fixture
wrapping around said shaft at the right side of said driving
section and fixed to said bracket at its edges; and a second
fixture wrapping around said shaft at the left side of said driving
section and fixed to said bracket at its edges.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a wheel loader, and more
particularly, to an attachment coupler for a wheel loader.
BACKGROUND OF THE INVENTION
[0002] Loaders have the facility for coupling and uncoupling an
attachment with a lifting arm or for switching between various
attachments such as a bucket, a clamp, or a fork.
[0003] A coupler is used to couple the attachment with the lifting
arm. Hydraulically powered displaceable pins are generally used for
the attachment coupler's locking. Namely, the attachment is guided
so that the locking holes are situated in a position in which
displaceable pins can be shot through them, following which these
pins, guided by controls located in the operating station, are
hydraulically activated and shot into the holes, thereby locking
the attachment with the lifting arm.
[0004] The hydraulically powered locking enables relatively rapid
change of attachments without leaving the operating site, but it
requires various hydraulic components such as actuators, conduits
and valves, thus making a complex structure. Also, the engine and
the whole machine should be turned on since this hydraulic coupler
depends upon existing machine hydraulics for activating the locking
pins.
[0005] On the other hand, manual couplers are relatively simple in
structure, but they require substantial efforts and time from users
for coupling or uncoupling for each and every locking position
between the bracket and the attachment.
SUMMARY OF THE INVENTION
[0006] According to one aspect of the present disclosure, there
provides a working machine, in this case a wheel loader which has a
coupler for coupling an attachment to a lifting arm. A coupler is
installed between the lifting arm and the attachments such as a
bucket, a clamp or a fork. The bracket's back face is pivotally
connected to the lifting arm and the bracket's front face is
detachably connected to the attachment.
[0007] The attachment has a pair of protrusions rearwardly
extending from the lower back of the attachment and laterally
spaced apart from each other. The protrusions have locking holes
pierced through their width. The bracket has a pair of receiving
slots formed at the lower front of the bracket and engaged with the
protrusions.
[0008] The coupler to lock the protrusions into the corresponding
receiving slots comprises a shaft fixed to the bracket by means of
fixtures and a pair of locking pins combined with the shaft by
threads.
[0009] The shaft has threads formed at both ends. The threads
formed at the one end of the shaft are right handed and the threads
formed at the other end of the shaft are left handed. The locking
pins are tubular, and inserted into the ends of the shaft,
respectively. The internal surface of the first tubular locking pin
has threads corresponding to the threads formed at the one end of
the shaft. Likewise, the internal surface of the second tubular
locking pins has threads corresponding to the threads formed at the
other end of the shaft.
[0010] The locking pins are longitudinally divided into two parts,
that is, a cylindrically cross-sectioned outer part and a
non-cylindrically cross-sectioned inner part. The cross-section of
the inner part can be partially flattened cylindrical shape or
polygonal shape.
[0011] A pair of holders are provided to support each of the
locking pins. The holders are fixed to the bracket. The contacting
surface of the holder corresponds to the non-cylindrical contour of
the inner part of the locking pin, thereby preventing the locking
pin from being rotated when the shaft is driven to rotate. That is,
the locking pins are rectilinearly moved due to a thread
interaction when the shaft rotates.
[0012] When users turn the shaft in one direction, for example
clockwise, locking pins installed on both ends of the shaft move
away from the center (extended), and the coupler has a coupling
position of the attachment in which the locking pins are extended
and the outer parts are engaged with the locking holes of the
protrusions. Likewise, when users turn the shaft in the other
direction, for example counter-clockwise, locking pins installed on
both ends of the shaft move toward the center (shortened), and the
coupler has a release position of the attachment in which the
locking pins are shortened and the outer parts are released from
the locking holes of the protrusions.
[0013] It is preferable that the shaft has a driving section with a
polygonal cross-section in order to enable users to turn the shaft
easily by using appropriate means such as a wrench.
[0014] It is preferable that the threads formed at the shafts and
the locking pins are multiple start threads which provide bigger
screw pitch so that the lead per rotation can be increased, which
can consequently minimize the effort of users when turning the
shaft.
[0015] The coupler of the present disclosure enables users to
couple or uncouple the attachment by one touch turning operation,
thus reducing the effort of users and saving time at work
sites.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a perspective view of the coupler and the
attachment according to one embodiment of the present
disclosure;
[0017] FIG. 2 is a disassembled perspective view of the coupler
according to one embodiment of the present disclosure;
[0018] FIG. 3A shows the coupler in its coupling position where the
locking pins are fully extended;
[0019] FIG. 3B shows the coupler in its release position where the
locking pins are fully shortened;
[0020] FIG. 4 is a perspective view of the bracket seen from the
lifting arm side and an enlarged view of part "A";
[0021] FIG. 5 is a disassembled perspective view of the coupler
according to another embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Reference will now be made in detail to embodiments of the
present disclosure, examples of which are illustrated in the
accompanying drawings. While the present disclosure will be
described in conjunction with the following embodiments, it will be
understood that they are not intended to limit the present
disclosure to these embodiments alone. On the contrary, the present
disclosure is intended to cover alternatives, modifications, and
equivalents which may be included within the spirit and scope of
the present disclosure as defined by the appended claims.
Furthermore, in the following detailed description of the present
disclosure, numerous specific details are set forth in order to
provide a thorough understanding of the present disclosure.
However, embodiments of the present disclosure may be practiced
without these specific details.
[0023] FIG. 1 shows a perspective view of a bracket 100 and an
attachment 102 according to one embodiment of the present
disclosure. Bracket 100 has a back face pivotally connected to the
free end of a lifting arm (not shown) of a wheel loader and a front
face detachably connected to attachment 102.
[0024] Throughout the entire description and claims, the wheel
loader is an example of the working machine to which the coupler of
the present disclosure applies. Therefore, it should be understood
that this coupler can apply to various kinds of working machine
which has a detachable and interchangeable tools as an attachment.
Some examples of such working machine are wheel loaders, track
loaders, excavators, and dozers. Likewise, the bucket is an example
of the attachment to which the coupler of the present disclosure
applies. It should be understood that this coupler can apply to
various kinds of attachment, for example, a clamp, a fork, a
breaker or a crusher.
[0025] Attachment 102 has a pair of hooks 110a, 110b rearwardly
extending from the upper back of attachment 102 and laterally
spaced apart from each other. Bracket 100 has a pair of cross bars
112a, 112b installed at the upper front of bracket 100.When
coupling attachment 102 to bracket 100, users bring attachment 102
to bracket 100 and have hooks 110a, 110b engaged with cross bars
112a, 112b.
[0026] Attachment 102 has a pair of protrusions 104a, 104b.
Protrusions 104a, 104b are rearwardly extended from the lower back
of attachment 102 and laterally spaced apart from each other.
Protrusions 104a, 104b have locking holes 106a, 106b pierced
through their width. Bracket 100 has a pair of receiving slots
108a, 108b.Receiving slots 108a , 108b are formed at the lower
front of bracket 100 and engaged with protrusions 104a, 104b.
[0027] FIG. 2 shows a disassembled perspective view of a coupler
200 according to the embodiment of the present disclosure.
[0028] The coupler 200 comprises a shaft 202 and a pair of tubular
locking pins 204a, 204b combined with shaft 202 by threads.
[0029] Shaft 202 has threads 216a, 216b formed at both ends. The
threads formed at the one end of shaft 202 (216a ) are "right
handed" and the threads formed at the other end of shaft 202 (216b
) are "left handed". Locking pins 204a, 204b are, at least
partially, tubular and inserted into the ends of shaft 202,
respectively.
[0030] The inside of the first tubular locking pin 204a has threads
218a corresponding to the threads 216a formed at the one end of
shaft 202. Likewise, the inside of the second tubular locking pin
204b has threads 218b corresponding to the threads 216b formed at
the other end of shaft 202.
[0031] The first locking pin 204a is longitudinally divided into
two parts, that is, a cylindrically cross-sectioned outer part 212a
and a non-cylindrically cross-sectioned inner part 210a. The
cross-section of inner part 210a can be shaped into a partially
flattened cylindrical shape or a polygonal shape.
[0032] Likewise, the second locking pin 204b is longitudinally
divided into two parts, that is, a cylindrically cross-sectioned
outer part 212b and a non-cylindrically cross-sectioned inner part
210b. The cross-section of inner part 210b can be shaped into a
partially flattened cylindrical shape or a polygonal shape.
[0033] A pair of holders 214a, 214b are provided to support
corresponding locking pins 204a, 204b, respectively. Holders 214a,
214b are fixed to bracket 100.
[0034] The contacting surface of the first holder 214a corresponds
to the non-cylindrical contour of the inner part 210a of the first
locking pin 204a. Therefore, the first locking pin 204a is
prevented from being rotated when shaft 202 is driven to rotate. In
other words, the first locking pin 204a is rectilinearly moved due
to a thread interaction when shaft 202 rotates.
[0035] Likewise, the contacting surface of the second holder 214b
corresponds to the contour of the inner part 210b of the second
locking pin 204b. Therefore, the second locking pin 204b is
prevented from being rotated when shaft 202 is driven to rotate. In
other words, the second locking pin 204b is rectilinearly moved due
to a thread interaction when shaft 202 rotates.
[0036] It is preferable that the longitudinal lengths of inner
parts 210a, 210b are longer than or at least equal to the
rectilinear moving strokes of locking pins 204a, 204b along shaft
202 so that the rotations of locking pins 204a, 204b are prevented
throughout the entire strokes of locking pins 204a, 204b.
[0037] When users turn shaft 202 in one direction, e.g., clockwise,
locking pins 204a, 204b move away from the center (extended), and
the coupler 200 has a coupling position of the attachment in which
locking pins 204a, 204b are extended and their outer parts 212a,
212b are engaged with locking holes 106a, 106b of protrusions 104a,
104b. FIG. 3A shows this coupling position where locking pins 204a,
204b are fully extended.
[0038] Likewise, when users turn shaft 202 in the other direction,
e.g., counter-clockwise, locking pins 204a, 204b move toward the
center (retracted), and the coupler 200 has a release position of
the attachment in which locking pins 204a, 204b are shortened and
their outer parts 212a, 212b are released from locking holes 106a,
106b of protrusions 104a, 104b. FIG. 3B shows this release position
where locking pins 204a, 204b are fully shortened.
[0039] It is preferable that the threads 216a, 216b of shaft 202
and the threads 218a,218b of locking pins 204a, 204b are multi
start threads. The multi start threads increase the lead per
rotation of locking pins 204a, 204b. Accordingly, locking pins
204a, 204b can have longer rectilinear moving strokes relative to
the rotation of shaft 202. In this embodiment, quadruple start
threads are used. Consequently, these multiple start threads
minimize the effort of users when turning the shaft.
[0040] It is preferable that shaft 202 has a driving section 208
with a polygonal cross-section in order to enable users to turn
shaft 202 easily by using an appropriate tool such as a wrench. In
this embodiment, the cross-section of driving section 208 is shaped
as hexagonal, and a hexagonal wrench is used to turn shaft 202.
[0041] FIG. 4 shows a perspective view of bracket 100 of the
embodiment of the present disclosure seen from a lifting arm side,
i.e., the back face of bracket 100 and an enlarged view of part
"A".
[0042] Referring to FIG. 4, reference numerals 206a, 206b are
fixtures used to affix shaft 202 to bracket 100. Fixtures 206a and
206b wrap around shaft 202 at the right side and at the left side
of driving section 208, respectively, in a less frictional manner
and bolted to bracket 100 at their edges. An anti-friction material
or coating (not shown) can be used on the contacting surfaces
between fixtures 206a, 206b and shaft 202.
[0043] Bracket 100 has an opening 304 in order to allow users to
access to drive section 208 of shaft 202 with a wrench.
[0044] According to the turning direction of shaft 202, coupler 200
has a coupling position of the attachment in which locking pins
204a, 204b are extended and engaged with locking holes 106a, 106b,
and a release position of the attachment in which locking pins
204a, 204b are shortened and released from locking holes 106a,
106b.
[0045] Referring back to FIG. 1, reference numerals 114a, 114b are
apertures formed at the outer walls 116a, 116b of receiving slots
108a, 108b. These apertures 114a, 114b secure the end of locking
pins 204a, 204b in the coupling position of the attachment.
Apertures 114a, 114b can be replaced with indentations in which the
end of locking pins 204a, 204b would not be exposed from the outer
walls 116a, 116b.
[0046] According to the embodiment described above, users can
achieve coupling or uncoupling the attachment to the machine by
simply turning the shaft in one direction or the other. Such a one
touch operation provided by the embodiment minimizes the effort of
users for coupling/uncoupling the attachment and saves time at work
sites.
[0047] FIG. 5 shows a disassembled perspective view of a coupler
according to another embodiment of the present disclosure.
[0048] FIG. 5 shows only a locking pin 412b of a pair of locking
pins and doesn't show the opposite locking pin. However, the
opposite locking pin has a same structure and function as locking
pin 412b, so it can be understood without additional details.
[0049] In this embodiment, the cross-sections of locking pin 412b
are non-cylindrical along their entire lengths or at least along
their outer parts that are subject to be engaged with the locking
holes of the protrusions. The cross-sections of this locking pin
412b can be shaped into a partially flattened cylindrical shape or
a polygonal shape.
[0050] In this embodiment, the contacting surface 414 of the
locking hole 416 of the protrusion correspond to the contour, i.e.,
the non-cylindrical cross-sections, of locking pin 412b, thereby
preventing locking pin 412b from being rotated when it is inserted
into locking hole 416. The contacting surfaces of aperture 418
formed at inner wall 420 of receiving slot 422 are also
corresponding to the contour, i.e., the non-cylindrical
cross-sections, of locking pin 412b. By this configuration, locking
pin 412b is rectilinearly moved due to a thread interaction when
shaft 402 rotates without the need of such holders shown in the
first embodiment of the present disclosure.
[0051] Although the invention has been described with reference to
the preferred embodiments in the attached figures, it is noted that
equivalents may be employed and substitutions made herein without
departing from the scope of the invention as recited in the
claims.
* * * * *