U.S. patent application number 13/661814 was filed with the patent office on 2014-04-10 for work tool coupler linkage.
This patent application is currently assigned to CATERPILLAR SARL. The applicant listed for this patent is CATERPILLAR SARL. Invention is credited to Florin Neamtu, George Pinther, Leigh Reeves, John Salay, Sage Smith.
Application Number | 20140096419 13/661814 |
Document ID | / |
Family ID | 50431603 |
Filed Date | 2014-04-10 |
United States Patent
Application |
20140096419 |
Kind Code |
A1 |
Pinther; George ; et
al. |
April 10, 2014 |
WORK TOOL COUPLER LINKAGE
Abstract
An electrically actuated coupling device for a machine and an
implement is disclosed. The device includes a frame and an electric
motor coupled to a drive shaft that extends between right and left
ends of the frame. The motor causes the shaft to extend or retract
from each end of the frame simultaneously. Each end of the frame
includes a guide for receiving a latch. Each latch is pivotally
coupled to a spring and each spring is pivotally coupled to a
specially shaped lever which is pivotally coupled to the frame as
well as an end of the shaft. The electric motor may be activated by
the operator from within the cab.
Inventors: |
Pinther; George; (Raleigh,
NC) ; Smith; Sage; (Apex, NC) ; Salay;
John; (Pittsboro, NC) ; Neamtu; Florin; (Apex,
NC) ; Reeves; Leigh; (Sanford, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CATERPILLAR SARL |
Geneva |
|
CH |
|
|
Assignee: |
CATERPILLAR SARL
Geneva
CH
|
Family ID: |
50431603 |
Appl. No.: |
13/661814 |
Filed: |
October 26, 2012 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13647105 |
Oct 8, 2012 |
|
|
|
13661814 |
|
|
|
|
Current U.S.
Class: |
37/468 |
Current CPC
Class: |
E02F 3/3659 20130101;
E02F 3/3627 20130101; E02F 3/364 20130101 |
Class at
Publication: |
37/468 |
International
Class: |
E02F 3/36 20060101
E02F003/36 |
Claims
1. An electrically actuated coupling device, comprising: a frame
having a right end and a left end; an actuator or extendable member
extending between the right and left ends of the frame, the
actuator causing the extendable member to expand outwards towards
the right and left ends of the frame simultaneously and to retract
inwards away from the left and right ends of the frame
simultaneously; the right end of the frame including a right guide
for slidably receiving a right latch, the left end of the frame
including a left guide for slidably receiving a left latch; the
right latch pivotally coupled to a right spring, the right spring
pivotally coupling the right latch to a right lever at a first
pivot point, the right lever being pivotally connected to the frame
at a second pivot point, the right lever being pivotally connected
to the shaft at a third pivot point; the left latch pivotally
coupled to a left spring, the left spring pivotally coupling the
left latch to a left lever at a fourth pivot point, the left lever
being pivotally connected to the frame at a fifth pivot point, the
left lever being pivotally connected to the shaft at a sixth pivot
point; wherein an angle between a first line extending through the
first and second pivot points and a second line extending through
the second and third pivot points ranges from greater than
20.degree. to less than 35.degree.; and wherein an angle between a
third line extending through the fourth and fifth pivot points and
a fourth line extending through the fifth and sixth pivot points
ranges from greater than 20.degree. to less than 35.degree..
2. The coupling device of claim 1 wherein the second and third
pivot points are separated by a first length, the first and second
pivot points are separated by a second length and the first length
is greater than the second length; and wherein the fifth and sixth
pivot points are separated by a third length, the fourth and fifth
pivot points are separated by a fourth length and the third length
is greater than the fourth length.
3. The coupling device of claim 2 wherein a ratio of the first
length to the second length ranges from greater than 1 to about
1.75; and a ratio of the third length to the fourth length ranges
from greater than 1 to about 1.75.
4. The coupling device of claim 3 wherein the ratios range from
greater than 1.31 to about 1.45.
5. The coupling device of claim 1 wherein an angle between a first
line extending through the first and second pivot points and a
second line extending through the second and third pivot points
ranges from greater than 20.degree. to less than 35.degree.; and
wherein an angle between a third line extending through the fourth
and fifth pivot points and a fourth line extending through the
fifth and sixth pivot points ranges from greater than 20.degree. to
less than 35.degree..
6. The coupling device of claim 1 wherein an angle between a first
line extending through the first and second pivot points and a
second line extending through the second and third pivot points
ranges from greater than 27.degree. to less than 31.degree.; and
wherein an angle between a third line extending through the fourth
and fifth pivot points and a fourth line extending through the
fifth and sixth pivot points ranges from greater than 27.degree. to
less than 31.degree..
7. The coupling device of claim 1 wherein an angle between a second
line extending through the second and third pivot points and an
axis of the shaft ranges from greater than 10.degree. to less than
25.degree.; and wherein an angle between a fourth line extending
through the fourth and fifth pivot points and an axis of the shaft
ranges from greater than 10.degree. to less than 25.degree..
8. The coupling device of claim 1 wherein an angle between a second
line extending through the second and third pivot points and an
axis of the shaft ranges from about 13.degree. to about 18.degree.;
and wherein an angle between a fourth line extending through the
fifth and sixth pivot points and an axis of the shaft ranges from
about 13.degree. to about 18.degree..
9. A machine comprising: a cab; right and left lift arms coupled to
a frame having a right end and a left end; an actuator with an
extendable member extending between the right and left ends of the
frame, the actuator causing the extendable member to expand
outwards towards the right and left ends of the frame
simultaneously and to retract inwards away from the left and right
ends of the frame simultaneously; the right end of the frame
including a right guide for slidably receiving a right latch, the
left end of the frame including a left guide for slidably receiving
a left latch; the right latch pivotally coupled to a right spring,
the right spring pivotally coupling the right latch to a right
lever at a first pivot point, the right lever being pivotally
connected to the frame at a second pivot point, the right lever
being pivotally connected to the shaft at a third pivot point; the
left latch pivotally coupled to a left spring, the left spring
pivotally coupling the left latch to a left lever at a fourth pivot
point, the left lever being pivotally connected to the frame at a
fifth pivot point, the left lever being pivotally connected to the
shaft at a sixth pivot point; and wherein the second and third
pivot points are separated by a first length, the first and second
pivot points are separated by a second length and the first length
is greater than the second length; wherein the fifth and sixth
pivot points are separated by a third length, the fourth and fifth
pivot points are separated by a fourth length and the third length
is greater than the fourth length; and wherein a ratio of the first
length to the second length ranges from greater than 1.31 to less
than 1.75, and a ratio of the third length to the fourth length
ranges from greater than 1.31 to less than 1.75.
10. The machine of claim 9 wherein the ratios range from greater
than 1.31 to about 1.45.
11. The machine of claim 9 wherein an angle between a first line
extending through the first and second pivot points and a second
line extending through the second and third pivot points ranges
from greater than 20.degree. to less than 35.degree.; and wherein
an angle between a third line extending through the fourth and
fifth pivot points and a fourth line extending through the fifth
and sixth pivot points ranges from greater than 20.degree. to less
than 35.degree..
12. The machine of claim 9 wherein an angle between a first line
extending through the first and second pivot points and a second
line extending through the second and third pivot points ranges
from about 27.degree. to about 31.degree.; and wherein an angle
between a third line extending through the fourth and fifth pivot
points and a fourth line extending through the fifth and sixth
pivot points ranges from about 27.degree. to about 31.degree..
13. The machine of claim 9 wherein an angle between a second line
extending through the second and third pivot points and an axis of
the shaft ranges from greater than 10.degree. to less than
25.degree.; and wherein an angle between a fourth line extending
through the fourth and fifth pivot points and an axis of the shaft
ranges from greater than 10.degree. to less than 25.degree..
14. The machine of claim 9 wherein an angle between a second line
extending through the second and third pivot points and an axis of
the shaft ranges from about 13.degree. to about 18.degree.; and
wherein an angle between a fourth line extending through the fifth
and sixth pivot points and an axis of the shaft ranges from about
13.degree. to about 18.degree..
15. A method for coupling and decoupling a tool to and from a
machine having right and left lift arms, the method comprising:
coupling a frame having a right end and a left end to the right and
left lift arms, the frame supporting an actuator with an extendable
member extending between the right and left ends of the frame, the
right end of the frame including a right guide for slidably
receiving a right latch, the left end of the frame including a left
guide for slidably receiving a left latch, the right latch
pivotally coupled to a right spring, the right spring pivotally
coupling the right latch to a right lever at a first pivot point,
the right lever being pivotally connected to the frame at a second
pivot point, the right lever being pivotally connected to the shaft
at a third pivot point, and the left latch pivotally coupled to a
left spring, the left spring pivotally coupling the left latch to a
left lever at a fourth pivot point, the left lever being pivotally
connected to the frame at a fifth pivot point, the left lever being
pivotally connected to the shaft at a sixth pivot point; aligning
the right and left latches with right and left openings in the
tool; activating the actuator to extend the extendable member
outwards towards the right and left ends of the frame thereby
causing the right and left latches to be received in the right and
left openings of the tool; and activating the actuator to retract
the extendable member inwards away from the right and left ends of
the frame thereby causing the right and left latches to be
withdrawn from the right and left openings of the tool; wherein an
angle between a second line extending through the second and third
pivot points and an axis of the shaft ranges from about 13.degree.
to about 18.degree. and wherein an angle between a fourth line
extending through the fifth and sixth pivot points and an axis of
the shaft ranges from about 13.degree. to about 18.degree..
16. The method of claim 15 wherein the second and third pivot
points are separated by a first length, the first and second pivot
points are separated by a second length; wherein the fifth and
sixth pivot points are separated by a third length, the fourth and
fifth pivot points are separated by a fourth length; and wherein
ratios of the first length to the second length and the third
length to the second length range from greater than 1.31 to less
than 1.75.
17. The method of claim 15 wherein the second and third pivot
points are separated by a first length, the first and second pivot
points are separated by a second length; wherein the fifth and
sixth pivot points are separated by a third length, the fourth and
fifth pivot points are separated by a fourth length; and wherein
ratios of the first length to the second length and the third
length to the second length range from greater than 1.32 to about
1.40.
18. The method of claim 15 wherein an angle between a first line
extending through the first and second pivot points and a second
line extending through the second and third pivot points ranges
from greater than 20.degree. to less than 35.degree.; and wherein
an angle between a third line extending through the fourth and
fifth pivot points and a fourth line extending through the fifth
and sixth pivot points ranges from greater than 20.degree. to less
than 35.degree..
19. The method of claim 15 wherein an angle between a first line
extending through the first and second pivot points and a second
line extending through the second and third pivot points ranges
from about 27.degree. to about 31.degree.; and wherein an angle
between a third line extending through the fourth and fifth pivot
points and a fourth line extending through the fifth and sixth
pivot points ranges from about 27.degree. to about 31.degree..
20. The method of claim 17 wherein an angle between a second line
extending through the second and third pivot points and an axis of
the shaft ranges from about 13.degree. to about 18.degree.; and
wherein an angle between a fourth line extending through the fifth
and sixth pivot points and an axis of the shaft ranges from about
13.degree. to about 18.degree..
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of application Ser. No.
13/647,105, filed on Oct. 8, 2012.
TECHNICAL FIELD
[0002] This disclosure relates generally to a quick coupling device
for a tool/implement for a machine and, more particularly, to a
quick coupling device that may be actuated by the operator from the
cab of the machine.
BACKGROUND
[0003] Machines frequently have lift arms with tools or implements
disposed at the ends of the lift arms. The tools or implements may
include as buckets, blades and the like. To simplify and expedite
the exchanging or replacement of such tools, the lift arms are
typically equipped with an attachment frame that includes coupling
devices for quickly coupling and decoupling the various implements
from the frame. Some of these coupling devices may also be
power-operated to reduce the necessity for manual intervention and
for ease of operation. Further, some coupling devices may be
actuated from inside the cab of the machine.
[0004] In U.S. Pat. No. 6,866,467, a hydraulically-actuated quick
coupling device includes an attachment frame. A pair of latch
members is disposed at each end of the attachment frame and the
latch members are movable between a latched position and an
unlatched position. A link has first and second end portions with
the first end portion of the link connected to the latch member. A
pivot member has first and second end portions and a central
portion with the first end portion pivotally connected on the
attachment frame and the second end portion pivotally connected on
the second end portion of the link. A cylinder has a head end
connected to the attachment frame and a rod end connected to the
central portion of the pivot member. The cylinder is operable for
moving the latch member between the disengaged and engaged
positions.
[0005] A low amount of force is required when the tool and coupler
are very clean, but in dirty conditions or with a lack of scheduled
lubrication or maintenance, the linkage can stick or jam, causing
the operator to have to use a pry bar to force the linkage loose
and engage/disengage the work tool.
SUMMARY
[0006] In one aspect, an electrically actuated coupling device is
disclosed. The disclosed device may include a frame having a right
end and a left end. The disclosed device may also include an
electric motor with a drive shaft extending between the right and
left ends of the frame. The motor may be used to cause the shaft to
expand outwards towards the right and left ends of the frame
simultaneously and to retract the shaft inwards away from the left
and right ends of the frame simultaneously. The right end of the
frame may include a right guide for slidably receiving a right
latch. The left end of the frame may include a left guide for
slidably receiving a left latch. The right latch may be pivotally
coupled to a right spring. The right spring may pivotally couple
the right latch to a right lever at a first pivot point. The right
lever may be pivotally connected to the frame at a second pivot
point. The right lever may also be pivotally connected to the shaft
at a third pivot point. Similarly, the left latch may be pivotally
coupled to a left spring. The left spring may pivotally couple the
left latch to a left lever at a fourth pivot point. The left lever
may also be pivotally connected to the frame at a fifth pivot
point. The left lever may also be pivotally connected to the shaft
at a sixth pivot point. Further, an angle between a first line
extending through the first and second pivot points and a second
line extending through the second and third pivot points may range
from greater than 20.degree. to less than 35.degree., and,
similarly, an angle between a third line extending through the
fourth and fifth pivot points and a fourth line extending through
the fifth and sixth pivot points may also ranges from greater than
20.degree. to less than 35.degree..
[0007] In another aspect, a machine is disclosed that may include a
cab. The machine may also include right and left lift arms that may
be coupled to a frame having a right end and a left end. The
machine may also include an electric motor with a drive shaft that
extends between the right and left ends of the frame. The motor may
cause the shaft to expand outwards towards the right and left ends
of the frame simultaneously and retract inwards away from the left
and right ends of the frame simultaneously. The right end of the
frame may include a right guide for slidably receiving a right
latch and the left end of the frame may include a left guide for
slidably receiving a left latch. The right latch may be pivotally
coupled to a right spring. The right spring may pivotally couple
the right latch to a right lever at a first pivot point. The right
lever may be pivotally connected to the frame at a second pivot
point. The right lever may also be pivotally connected to the shaft
at a third pivot point. The left latch may also be pivotally
coupled to a left spring. The left spring may pivotally couple the
left latch to a left lever at a fourth pivot point. The left lever
may be pivotally connected to the frame at a fifth pivot point and
the left lever may be pivotally connected to the shaft at a sixth
pivot point. The machine may also include a control switch for
controlling the motor wherein the control switch is disposed inside
the cab. Further, the second and third pivot points are separated
by a first length and the first and second pivot points are
separated by a second length. The first length is greater than the
second length. The fifth and sixth pivot points are separated by a
third length and the fourth and fifth pivot points are separated by
a fourth length. The third length is greater than the fourth
length. A ratio of the first length to the second length ranges
from greater than 1.31 to less than 1.75, and a ratio of the third
length to the fourth length ranges from greater than 1.31 to less
than 1.75.
[0008] In another aspect, a method for coupling and decoupling a
tool to and from a machine having right and left lift arms is also
disclosed. The method may include coupling a frame having a right
end and a left end to the right and left lift arms. The frame may
support an electric motor with a drive shaft extending between the
right and left ends of the frame. The right end of the frame may
include a right guide for slidably receiving a right latch and the
left end of the frame may include a left guide for slidably
receiving a left latch. The right latch may be pivotally coupled to
a right spring and the right spring may pivotally couple the right
latch to a right lever at a first pivot point. The right lever may
also be pivotally connected to the frame at a second pivot point
and to the shaft at a third pivot point. The left latch may be
pivotally coupled to a left spring. The left spring may pivotally
couple the left latch to a left lever at a fourth pivot point. The
left lever may be pivotally connected to the frame at a fifth pivot
point and to the shaft at a sixth pivot point. The method may
include aligning the right and left latches with right and left
openings in the tool. The method may further include activating the
motor to expand the shaft outwards towards the right and left ends
of the frame thereby causing the right and left latches to be
received in the right and left openings of the tool. Further, the
method may also include activating the motor to retract the shaft
inwards away from the right and left ends of the frame thereby
causing right and left latches to be withdrawn from right and left
openings of the tool. Further, an angle between a second line
extending through the second and third pivot points and an axis of
the shaft ranges from about 13.degree. to about 18.degree. and an
angle between a fourth line extending through the fifth and sixth
pivot points and an axis of the shaft ranges from about 13.degree.
to about 18.degree..
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of a machine coupled to a
bucket.
[0010] FIG. 2 is a plan view of a disclosed coupling device, with
the latches in an intermediate position.
[0011] FIG. 3 is a perspective view of the disclosed coupling
device, particularly illustrating the latches in an intermediate
position.
[0012] FIG. 4 is a partial perspective view of the disclosed
coupling device, particularly illustrating the right latch in an
intermediate position.
[0013] FIG. 5 is a partial plan view of the disclosed coupling
device, particularly illustrating the right latch in an
intermediate position.
[0014] FIG. 6 is a partial plan view of the disclosed coupling
device, particularly illustrating the left latch in an intermediate
position.
[0015] FIGS. 7-8 are partial plan views showing the left latches
and associated linkages in retracted and extended positions
respectively.
[0016] FIG. 9 is another partial plan view of the disclosed
coupling device, particularly illustrating the right latch in a
retracted position and an angle defined by a line drawn through the
first and second pivot points and a line drawn through the second
and third pivot points as well as an angle defined by a line drawn
through the third and second pivot points and an axis of the shaft;
and
[0017] FIG. 10 is a plan view of the left lever of the disclosed
coupling device.
DESCRIPTION
[0018] FIG. 1 illustrates a machine 10 that may be equipped with
the quick coupling device 11 shown in FIG. 2. In the example shown,
the machine 10 is a skid steer loader. The machine 10 includes a
frame 16 that is supported above ground by a plurality of ground
engaging elements 13. While the ground engaging elements 13 are
wheels, in the example shown, this disclosure is also applicable to
track-type machines as well. The machine 10 also includes a pair of
spaced apart lift arms 14 and an implement 15, in the form of a
bucket that may be coupled to the lift arms 14. The machine 10 may
be used with a variety of implements, other than the bucket shown
at 15. To quickly and easily disconnect or decouple the implement
15 from the machine 10, it would be advantageous to include a quick
coupling/decoupling device like that shown at 11 in FIG. 2.
[0019] Turning to FIG. 2, the coupling device 11 includes a frame
16 with a right end 17 and a left end 18. The frame supports a
motor 19 that drives an expandable and retractable shaft assembly
21. As will be apparent to those skilled in the art, the motor
19/shaft assembly 21 combination may be replaced by a hydraulic
cylinder or another type of actuator and extendable member. The
shaft assembly 21 includes a right end 22 and a left end 23. The
right and left end 22, 23 of the shaft assembly 21 are coupled to
right and left levers 24, 25 respectively. As will be explained in
greater detail below, the right and left levers 24, 25 pivot when
the shaft assembly 21 is expanded or retracted. For example, when
the shaft assembly 21 is retracted, upward bias is imposed upon the
right and left springs 26, 27 respectively. The right and left
springs 26, 27, as explained in greater detail below, are coupled
to right and left latches 28, 29 at the pivot points 20, 30
respectively. The right and left latches 28, 29 are used to couple
the frame 16 to the implement 15 as shown in FIG. 1. Also shown in
FIG. 2 are right and left guides 31, 32 which slidably receive the
latches 28, 29 respectively.
[0020] Turning to FIG. 3, the right and left latches 28 are also
shown in extended positions. To retract the latches 28, 29, the
shaft assembly 21 is retracted inwardly, that is, both the right
end 22 and the left end 23 are retracted inwards or away from the
right and left ends 17, 18 of the frame 16. The right spring 26 may
be pivotally coupled to the lever 24 at a first pivot point 33. The
right lever 24 may be pivotally coupled to the right end 17 of the
frame 16 at a second pivot point 34. Further, the right lever 24
may be pivotally coupled to the right end 22 of the shaft assembly
21 at a third pivot point 35. Similarly, the left lever 25 may be
pivotally coupled to the left spring at a fourth pivot point 36.
The left lever 25 may also be pivotally coupled to the left end 18
of the frame 16 at a fifth pivot point 37, and the left lever 25
may be pivotally coupled to the left end 23 of the shaft assembly
21 at a sixth pivot point 38.
[0021] Turning to FIG. 4, the right lever 24 includes a front plate
41 coupled to a rear plate 42. The plates 41, 42 may be welded
together, connected together in some other fashion or may be a
unitary structure. As shown in FIG. 4, the right end 22 of the
shaft assembly 21 has been moved to the left in the orientation of
FIG. 4 thereby biasing the third pivot point 35 to the left. This
causes the right lever 24 to pivot about the second pivot point 34
in a downward direction as indicated by the arrow 43. Movement of
the right lever 24 in the direction of the arrow 43 causes the
first pivot point 33 to move downward thereby compressing the right
spring 26. The right spring 26 which is pivotally coupled to the
right latch 28 at the pivot point 20 presses the right latch 28
downward through the right guide 31 to the latching or coupling
position shown in FIG. 4.
[0022] A plan view of the position shown in FIG. 4 is also shown in
FIG. 5 and a plan view of the left side 18 of the frame in the
coupled or extended position is shown in FIG. 6. Also shown in
FIGS. 5-6 are shaped opening 44, 57 which can receive a tool in the
event the coupling device 11 becomes stuck or jammed. Further,
FIGS. 5-6 also illustrates the outwardly extending tabs 45, 47 of
the front and rear plates 41, 42 and 141, 142 of the right and left
levers 24, 25 respectively. The tabs 45, 47 are visible to the
operator in the cab 46 of the machine 10 so the operator has a
visual indication that the coupling device 11 is in the coupled or
latched position shown in FIGS. 4-6. As shown in FIG. 9, the tab 45
is obscured and not clearly visible to the operator, thereby
indicating to the operator that the coupling device 11 is in the
decoupled or detached position shown in FIG. 3.
[0023] FIGS. 7-8 illustrate the retraction and extension of the
left latch 29, which may operate in the same fashion as the right
latch 28. In FIG. 7, the shaft assembly 21 has been retracted, or
moved to the left in the orientation of FIGS. 7-8. The pivot point
38 of the lever 25 has been moved to the left and upwards, thereby
causing the pivot point 36 to pull upward on the spring 27, which
causes the left latch 29 to retract upward into the guide 32.
Conversely, in FIG. 8, the shaft assembly 21 has been extended, or
moved to the right in the orientation of FIGS. 7-8. The pivot point
38 of the lever 25 has been moved to the right and downwards,
thereby causing the pivot point 36 to bias the spring 27 downwards,
which causes the left latch 29 to outward from the guide 32.
[0024] FIG. 9 illustrates geometrically the improved performance of
the coupling device 11. Specifically, the lever 24 includes three
pivot points including the first pivot point 33, which pivotally
couples the lever 24 to the spring 26. The lever 24 also includes a
second pivot point 34 which may pivotally couple the lever 24 to
the frame 16. Finally, the lever 24 includes a third pivot point 35
which may pivotally couple the lever 24 to the right end 22 of the
shaft assembly 21. It has been found that an angle 51 defined by a
first line 52 that extends through the first pivot point 33 and the
second pivot point 34 and a second line 53 that extends through the
second pivot point 34 and the third pivot point 35 may be greater
than 20.degree. and less than 35.degree. for optimal operation.
While the angle 51 may range from greater than 20.degree. to less
than 35.degree., a narrower range of from about 27.degree. to about
31.degree. may provide even better performance. In one example, the
angle 51 may be about 29.degree.. Similarly, another angle 54 has
surprisingly been found to have an effect on the performance on the
coupling device 11. The angle 54 is defined by the line 53 that
extends through the second and third pivot points 34, 35 and the
axis 55 of the shaft assembly 21. The angle 54 may range from
greater than 10.degree. to less than 25.degree.. While the angle 54
may range from greater than 10.degree. to less than 25.degree., a
narrower range of from about 13.degree. to about 18.degree. may
provide a more optimal performance. In one example, the angle 54 is
about 16.degree..
[0025] The dimensions of the levers 24, 25 have also been
surprisingly found to be useful in optimizing the performance of
the coupling device 11. The left lever 25 is illustrated in FIG. 7.
It also includes a shaped opening 57 for receiving a tool in the
event the coupling device 11 becomes stuck or jammed. The fourth,
fifth and sixth pivot points are shown at 36, 37, 38 respectively
and they correspond to the first, second and third pivot points 33,
34, 35 of the right lever 24. The distance between the fourth and
fifth pivot points is shown at 61. The distance between the fifth
and sixth pivot points is shown at 62. It has been surprisingly
found that the ratio of these two distances affects the performance
of the coupling device 11. First, the length or length 62 is
greater than the length or length 61. Further, a ratio of the
length 62 to the length 61, for effective operation of the coupling
device 11, may range from greater than 1 to about 1.5. While the
ratio of the length 62:length 61 may range from greater than 1 to
about 1.5, and more optimal performance may be found using a ratio
falling within the range of from about 1.32 to about 1.45. In one
embodiment, the ratio of the length 62 to the length 61 is about
1.4. It has been found that using two pivot points 36, 38 instead
of a single pivot point coupling the lever 25 to both the left
spring 27 and the shaft assembly 21 permits the coupling device 11
to have a higher engagement force, which enables the coupling
device 11 to operate effectively in non-optimal conditions such as
where corrosion may exist, debris or dirt may have infested the
linkage, maintenance or lubrication may be required, etc.
INDUSTRIAL APPLICABILITY
[0026] The coupling device 11 has been described above. It may be
used to quickly and easily change implements 15 on the machine 10
and the activation of the coupling device 11 may be performed by
the operator in the cab 46. All that is required is that the right
and left latches 28, 29 be aligned with corresponding openings in
the tool or implement 15. Then the operator activates the motor 19
(or hydraulic system or actuator) to extend the shaft assembly 21
(or cylinder or extendable member) outward which results in the
right and left latches 28, 29 extending downward through their
respective guides into the openings of the tool or implement 15.
Disengagement of the tool or implement 15 from the frame 16 is also
easily accomplished by activating the motor and retracting the
shaft assembly 21 laterally inwards away from the right and left
ends 17, 18 of the frame 16.
* * * * *