Note: Descriptions are shown in the official language in which they were submitted.
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FIELD OF THE INVENTION
This invention pertains to universal type
couplers for connecting a work implement to the front of
a tractor.
BACKGROUND OF THE INVENTION
It is known to provide a front frame attachment
to a tractor, so as to secure a work implement for industrial
or agricultural applications, or for lawn care. Such
attachments do, however, have several drawbacks:
1) for their installation on the tractor, they
require at least two persons: one driving the
tractor, the other adjusting the tractor attach-
ment hitch to the implement bracket assembly;
2) it is a safety hazard for a person to be
manipulating the attachment member between the
implement and the tractor with the tractor driver
displacing the tractor, especially when the tractor
driver is lnexperienced;
3) they are usually made in view of connection with a
specific tractor and/or implement, and accordingly,
each time one implement has to be replaced by another,
the attachment member must be changed as well;
this is, of course, time consuming and tiring for
the operator;
4) when one considers that the attachment member that
interconnects the work implement to the tractor
may cost up to half that of the implement ~ se;
it can be understood that it is highly cost-inefficient
to require a plurality of such attachment members
corresponding to the number of implements used.
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OBJECTS OF THE INVENTION
The main object of the invention is to provide
a coupler of the universal type, capable of releasably inter-
connecting any one of a wide variety of work implements
to most conventional farm and industrial tractors, lawn-and
garden tractors, and the like vehicles.
An object of the invention is to simplify the
process of connection of a work implement to a tractor
front end chassis.
An object of the invention is to reduce the time
required for the process of replacing one work implement for
another.
An object of the invention is to provide such
a coupler which requires only one operator to uncouple a
given implement as well as to couple an alternate implement
to the vehicle.
Accordingly, an important object of the above
coupler is to substantially decrease the safety hazards
related to the above-noted uncoupling and coupling
operations.
Another object of the invention is to decrease
the ratio of the price of the above-mentioned coupler to
the price of any one of many implements relative to the
corresponding ratio for conventional front tractor
mounting means.
SUMMARY OF THE INVENTION
A coupler for connecting a work implement to the
front portion of a tractor, comprising: a tenon part and
a mating mortise part; both parts of rectangular cross-
section; said mortise part: consisting of a hollow width-
and thickness-tapered open casing defining a mouth at the
larger rear end and a smaller opposite front end which is
adapted to be attached to said work implement or to said
tractor; said tenon part defining a main opened
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rigid frame having one tapered front and engageable into
said tapered casing to a coupled position, the rear end
of said tenon part adapted to be fixedly secured to the
other one of said work implement or of said tractor. Latching
means are provided to latch said tenon member within said
mortise member in the coupled position of the same. Spring
means are further provided, which act on the latching
means to cause the latter to bias the tenon member and
mortise member in coupled position. The latching means
preferably comprise a pivot lever transversely journalled
to said tenon frame and defining an intermediate offset
section and an outwardly-projecting handle, a rigid latch bar
carried by the offset lever section for translation of the
latch bar by said offset section during rotation of said
pivot lever handle, between a latching and an unlatching
position. The latch bar is guided in the tenon part for com-
bined longitudinal and vertical movement. During latching,
the bar moves rearwardly upwardly, so as to engage a slot
made in the top wall of said mortise casing and, finally,
abuts the rear end of said slot. Preferably, the spring
means consist of a compression spring located between said
offset lever section and said latch bar.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of one embodiment of
a tenon-and-mortise coupler according to the invention,
operatively interconnecting the front bottom portion of a
tractor chassis to the bracket assembly of a large push blade,
the blade and part of the tractor shown in dotted lines;
Figure 2 is an enlarged perspective view of a second
embodiment of the coupler operatively interconnecting the
front bottom portion of a tractor chassis to the bracket
assembly of a snowblower attachment, and the power take-off
drive shaft to the snowblower impeller, the tractor
and snowblower being partially shown in dotted lines.
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Figure 3 is an enlarged top plan view of the first
embodiment of coupler and associated bracket assembly of
Figure 1.
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.
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Figure 4 is a longitudinal sectional view of the
tenon portion of both embodiments`of the invention,
showing in dotted lines the alternate positions of the
movable elements;
Figure 5 is a longitudinal sectional view of the
tenon-and-mortisQ portions of both embodiments of the
invention, in their operative interlocked condition;
Figure 6 is a side elevation of the second
embodiment of the assembled tenon-and-mortise portions and
associated adjacent elements showing the relative play of
the assembly under hydraulic control;
Figure 7 $s an enlarged fragmentary top plan
view of the tenon portion of the coupler, its top wall
being partly broken to clearly shown the pivotal lcoking
lever;
Flgure 8 is an enlarged cross-sectional view taken
along llne 8-8 of Figure 7; and
Flgure 9 is a partial plan section taken along
line 9-9 of Figure 5.
DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION
Coupler 12 according to the invention includes
a tenon portion 14, adapted to be releasably secured to the
front bottom portion of the chassis 16 of a farm tractor
18, or the like vehicle, and a mortise portion 20 releas-
ably engageable with tenon portion 14 at one end, and at
the other end into the bracket assembly 22 of an implement,
such as a push blade 24 (Fig. 1). Coupler tenon 14 defines
a pair of sturdy elongated bars 26 (Fig. 3), interconnected
at one end by a transverse, rear plate ~8, and at the other
end by a rigid, transverse cylindrical tube 30. Bars 26
are parallel along a main rear portion thereof 26A but at
a short front end portion thereof corresponding to that of
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tube 30; they are converging toward each other at 26B, to
widthwise
form a tapered section having a total taper angle of about
3(). Bar sections 26B are symmetric. Moreover, the width
of bar sections 26B decreases toward tube 30, whereby the
top edges 27A, 27B of bar sections 26A, 26B are coplanar but
their bottom edges 27C, 27D are not, see Figure 4. Preferably
the bottom edges 27D make a thicknesswise taper angle of
about 7 with top edges 27A, 27B.
Mortise portion 20 defines a hollow tapered casing
32, having a rear mouth 34 at its larger end of such a shape
as to be adapted to be engaged by tenon-tapered section 26B-
30-26B. The length of legs 26B represents only about half the
length of mortise casing 32, whereby one-half of the hollow
of casing 32 is therefore free.
As best shown in Figures 5 and 7, the tenon portion
14 further includes crank-shaped lever 36 transversely jour-
nalled through the two bar sections 26A. Crank lever 36 has
an intermediate offset section 38 and one end extending out-
wardly from a bar 26A and bent to form a handle 40. Thus,
manual rotation of handle 40 brings lever 36 in rotation
with lever offset 38 making a circle of arc.
A transverse wall 42 (Fig. 3) interconnects the pair
of bar sections 26A, 26B. More particularly, wall 42
includes a front wall portion 44 interconnecting the bar top
edges 27A, 27B joining with tube 30 and overlying lever 36,
and a rear wall portion 46 interconnecting the bar bottom
edges 27C, whereby a steeply-inclined wall portion 48 is
defined therebetween.
A stirrup 50 is transversely mounted around lever 26
about lever offset 38, wherein lever 36 is movable longi-
tudinally and rotatively therein. A rear prong 52 of an
elongated latch bar 54 is inserted between and welded to
the two legs 56 of stirr~p50. To the front end of latch bar
54 is fixed a double-headed pin 58, which interconnects
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a pair of guide plates 60 taking in sandwich latch bar 54,
through angular slots 62 made in guide plates 60. The
latter include diverging rear legs 60A having concave
free ends 60B engaged against conforming crank lever 36, and
main parallel front legs 60C, through which pin 58 extends,
and having concave free ends 64 engaged against and conform-
ing to tube 30. Therefore, guide plates 60 are retained in
position by engaging tube 30 and crank lever 36 at its
ends, and by the heads of pin 58 which slidably overly the
outside of plates 60. A push rod 66 is slidable through web
57 of stirrup 50 and carries a push plate 72, which abuts
against lever offset 38 under the bias of a compression coil
spring 70 which extends between web 57 and push plate 72
and surrounds push rod 66. A stop ring 73, fixed to the
rear end of rod 66, is adapted to abut against web 57 in
its fully retracted-position.
Hence, it is understood that lever offset 38 is
taken in sandwich between spring-biased push plate 70 and
prong 52 of latch bar 54.
Latch bar 54 includes two lengthwisely-spaced
upt~rned.~ projections or latches 74 and 76. The rear
latch 74 is a safety latch adapted to releasably engage
a slot 78 in panel 44. The front latch 76 is the main
latch and is adapted to releasably engage a longer slot 80
in panel 44.
Due to the shape ofslots 62 and to the offset
38 of lever 36, latch bar 54 is movable during rotation
of lever 36 between an inoperative retracted position,
shown in dotted lines in Figure 5, where safety latch 74
i6 c~m~etely retraated~f.Eo~ slot 78, and main latch 76
is substantially flush with slot 80, to an operative
posltion, shown in full lines in Figure 5,where safety latch
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74 protrudes from slot 78 and main latch 76 from slot 80,
As shown in Figure 4, clockwise rotation of lever 36 from
the position 40a to forward position 40b of handle 40,
causes latch bar 54 to move from its forward position
and downward retracted position to its rearward and upward
latching position. In latching position, pin 58 engages
the upper horizontal leg of angular slots 62 (Fig. 5), while
lever offset 38 is upwardly rearwardly inclined from the
journalled portions of lever 36. When female portion 20 is
engaged by male portion 14, latch 76 in $ts operative, retract-
ed position will register with a long slot 82 in the top
wall of casing 32. In the latching position of latch bar
54, main latch 76 abuts against the rear end 82a of slot 82
under the bias of slightly-compressed spring 70. Thus,
mortise portion 20 is firmly retained over tenon portion
14, but wlll yield if subjected to a sudden large pulling
force: part breakage is thus prevented.
By having safety pin 84 (Figure 3) engage a through-
bore 86 made in safety latch 74, so that the safety pin 84
extends over panel 44, accidental retraction of latch bar 54
is prevented.
The implement bracket assembly 22 of the first
embodiment (Yigures 1, 3) consists of an open rectangular
casing 88 into which is engageable the tapered end 90 of
female portion casing 32. Casing 88 is pivoted at its front
intermedlate section to tapered end 90 by a vertical pivot
axle 92. Also, casing 88 includes a number of spaced bores
94 on its rear intermediate portion, concentric to pivot
ax~e 92. Anyone of bores 94 is adapted to selectively
register with a central sleeved bore 96 in mortise casing
32, and an L-shaped locking pin 98 is releasably engageable
through the registering bores 94, 96 to lock together casings
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32 and 88 at an adjusted angular angle. Thus, as best shown
in Figure 3, bracket assembly 22 and, thus, the angle of
implement, such as blade 24 to the rear of which assembly
22 is fixed, can be adjusted.
The second embodiment of coupler of the invention
is shown in Figures 2 and 6, and denoted 100. Coupler 100
is identical to coupler 12 but for the elements detailed
below. Coupler 100 is more specifically adapted to inter-
connect the front chassis 16 of tractor 18 to the bracket
assembly 102 of an implement, such as a snowblower accessory
104, which requires up-and-down movement and connection
of the tractor power take-off by a telescopic drive shaft 106, or
V-belt, c4nnected to snowblower impeller (not sho~n) for driving
the same. Simllar tenon-and-mortise sections 14, 20 are
provided; however, tenon bars 26 are further provided with
yokes 110, each welded at both ends to the exterior face
of a bar 26. A transverse pin 112 pivotally connects
to yoke 110 and bar 26 the piston rod 114 of a double-
acting hydraulic cylinder 116, the top end of which is pivot-
ally transversely mounted on a bracket plate 118 fixed
to an upper portion of tractor chassis 16.
The bars 26 are further pivotally connected at
their rear end to the chassis 16 by a horizontal pivotal
axle 120 at the top of an upturned rigid flange 122, each
fixedly secured to bars 26. Thus, cylinders 116 fed by
hydraulic lines 124, are adapted to hydraulically-control
pivotal movement about axle 120 of the whole coupler 100 and
associated bracket assembly 102, so as to raise snowblower
104 when not in use.
In the embodiment of Figure 1, side bars 26 may
be also be pivotally connected to the tractor chassis by
axle 120 and tenon portion 14 pivotally urged to an
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upper limit position abutting the underside of a stop
member 126 under the action of a tension spring 128.
For installation of the coupler 12 or 100, a
sir~gle person, the truck driver, drives tractor 18, so
that tenon part 14 engages mortise part 20. Then, he
turns off the tractor engine and immobilizes the tractor;
he steps down from the tractor seat; he operates handle 40
to latching position and inserts safety pin 84 into bore
86 to lock latch bar 54 in its operative position.
