Note: Descriptions are shown in the official language in which they were submitted.
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BACKHOE MOUNTING
BACKGROUND OF THE INVENTION
1. Field of the Invention: Thls invention relates to excavator
machlnes and more particularly to vehicles on which a backhoe is moun-ted to
form an excavator machine.
2. Description of the Prior Art: Attempts have been made heretofore
to maximize the effectiveness and efficiency of backhoes and the vehicles
on which they are mounted by reducing the size and weight of both the
backhoe and the vehicle for a specified digging depth and capacity, or,
stated differently, by increasng the digging depth or capacity without
0 increasing the size and weight. For example, in U.S. Patent 4,272,222Davis an additional rigid link was added to the previously ]cnown backhoe
linkage to increase the digging depth of the backhoe. The backhoe boom is
articulated so as to present a joint between the inner and outer sec-tions
thereof. The joint is located in a position that is spaced outwardly from
the point of pivoting attachment of the lift cylinder to the support for
the boom, and the rigid link transversely and pivotally interconnects the
lift cylinder and the inner section of the boom.
In the present invention a subframe for mounting a backhoe is pivotally
connected to the main frame of the vehicle about a transverse axis near one
end of the main frame. Means are provided for selectively pivoting the
backhoe mounting subframe between a work position and a transport position.
Additional means are provided for securing the backhoe mounting subframe to
the vehicle main frame either at the work position or at the -transport
position. A backhoe is ~ounted on the backhoe mounting subframe.
FIGURE 1 is a profile view of an excavator machine which embodies this
invention,
FIGURE 2 is a partia] side elevation of the machine in the work
position,
FIGURE 3 is a similar partial side elevational view with the machine in
the transport position,
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FIG~RE 4 is a partial plan view of the machine in the work position
showing elements of the present invention,
FIG~RE 5 is a partial view o~ the machine in the transport position
from an elevated position showing pivoting and latching devices,
FIGURE 6 is a partial view showing a latching device and its cylinder
operator in the unl.atched position, and
FIGURE 7 is a similar view to FIG. 6 except showing the machine in the
latched condition.
In FIG. 1 and in other figures the numeral 10 indicates generally a
backhoe mounting mechanism in accordance with the present invention. As
shown a backhoe 12 is mounted by means of the present invention on a
vehicle 1~ to form an excavator machine which is designated in its entirety
by the numeral 16. The vehicle 1~ includes a main fra~e membe.r 18 which is
seen in FIGS. 1-5. A backhoe mounting subframe 20 is pivotally mounted on
frame 18 to pivot about axis 22. As seen in FIG. 4 the backhoe mounting
subframe includes a pair of forwardly extending vertical brackets 24 and 26
connected to the two sides of the vehicle frame 18 to pivot the subframe 20
on frame 18 about axis 22. The axis 22 is formed by a pair of pivot pins
on opposite sides of the vehicle and subframe, the pin on the near side in
FIGS. 2 and 3 being indicated by -the number 28. Subframe 20 also includes
a pair of rearwardly extending upper and lower horizontally disposed
bracket portions 31 and 32; see FIGS. 2 and 3. Also included in the
backhoe mounting mechanism 10 is a swing frame 3~ which is connected
between horiæontal brackets 31 and 32 to pivot about axis 36 with respect
to such brackets. This swing frame construction allows the backhoe 12
which is mounted on swing fxame 3~ to pivot through an arc of almost 180
from one side of the machine to the other.
FIGURE 2 of the drawing shows the backhoe mounting subframe 20 in the
work position. In this condition a hydraulic cylin.der 38 which connects
between the subframe 20 and the vehi.cle main frame 18 is retracted causing
the subframe to be pivoted to its lowermost and innermos-t position. When
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cylinder 38 is extended the subframe is pi~oted upwardly and outwardly to
-the posi-tion shown in FIG. 3. This is the transport position. A
transverse latching device 40, mounted on vehicle frame 18, which is shown
in FIGS. 4 through 7, is operable by the vehicle operator to latch subframe
20 to vehicle frame 18. Such latching mechanism is shown in the latched
condition in FIGS. 4, 5 and 7. In FIG. 6 it is shown in the unlatched
condition. The latching mechanism 40 comprises a hydraulic cylinder 42
which is extended to latch the subframe -to the main frame and retracted to
accomplish unlatching. As illustrated in FIG. 4 the latching mechanism 40
0 includes pins 44 and 46 at opposite ends oE the mechanism which when
extended project into openings 45 and 47 respectively in the brackets 24
and 26 on the opposite sides of subframe 20. This is the work position.
There is another pair of openings in brackets 24 and 26, one of which
appears at 49 in FIG. 3, into which the pins 44 and 46 project when the
machine is in the transpor-t position. Referring to FIGS. 6 and 7 pin 46 is
connected to cylinder 42 at 48 while pin 44 is connected with a collar 50
at location 52, and collar 50 in turn is connected to the piston rod 54
forming a part o~ cylinder 42. A spring 56 is provided to urge the
latching mechanism 40 toward the latched position when cylinder 4~ is not
pressurized.
When the cylinder 42 is pressurized and the latching mechanism 40 is in
the unlatched condition the backhoe mounting subframe 20 and the backhoe
mounted on it may be moved between the work position, shown in dashed lines
in FIG. 1, and the transport position, shown in solid lines in FIG. 1, by
operating a hydraulic cylinder 38 which is connected between the main frame
18 and the subframe 20. The hydraulic cylinders 38 and 42 both are
operated remotely by the operator of the vehicle in a known manner.
Reference herein to "hydraulic cylinder" means a double acting linear
hydraulic motor comprising an outer barrel portion with both ends closed
and an internal piston forming variable volume chambers between the piston
and the respective ends of the barrel portion. The piston is mounted on a
rod which projects throuqh the closure at one end of the barrel portion.
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Pivoting the backhoe 12 and its subframe mountinq 20 to the work
position allows the lowest part of the subframe and also the backhoe to be
closer to the ground than previously known backhoe designs. Since the
backhoe is located closer to the ground in the working or digging position
it can dig deeper than previously known backhoes with the same length boom
and dipper stick. When the backhoe is in the transport position the center
of gravity of the backhoe 12 is farther forward than when it is in the work
position. This transfers more of the backhoe weight towards the front of
the machine 14 giving the machine excellent balance which allows the
operator to drive the machine on the highway at transport speed without
undue bouncing of the machine or loss of control. When the subframe 20 is
in the transport position the 1owest part of the backhoe is on the same
level as the lowest part of the vehicle frame, which facilitates
maneuvering the machine. Another advantage of this invention when the
backhoe is in the store position is that the most rearward point of the
backhoe is within the turning radius of the machine, meaning that the
operator need not be concerned about the rear part of the backhoe hitting
something during a turning maneuver.
While we have described and illustrated herein a preferred embodiment
of our invention which is also the best mode contemplated for carrying it
out, it will be understood that changes and modifications may be made. It
should be understood, therefore, that we intend to cover by the appended
claims all such changes and modifications which fall within the true spirit
and scope of our invention.
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