Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
Many vehicles, such as fork lift trucks, have counterweights -
rigidly attached to an end portion thereof. Fork lift trucks normally do
not have springs between the frame and wheels, and one of the problems
encountered therewith, particularly when the truck has the so-called
cushioned tires thereon, is that the inertia forces of the counterweight
causes jolting shock loads to be exerted on the frame when the vehicle is
operated on rough surfaces. These shock loads are transmitted directly to
the frame and eventually to the operator. It is desirable to reduce the
shock loads on the frame. This would in turn decrease wear on the vehicle
and reduce operator fatigue caused by the shocks.
Summary of the Invention
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The present invention is directed to overcoming one or more of
the problems as set forth above.
According to the present invention, there is provided a vehicle
comprising: a frame assembly having an end portion; a counterweight
positioned adjacent the end portion of the frame assembly; means for
connecting the counterweight to the frame assembly and permitting limited
upward ant downward movement thereof relative to the frame assembly; and
resilient supporting means connected to the end portion of the frame
assembly and attached to the counterweight for resiliently supporting the
counterweight and for cushioning shock loads exerted on the frame assembly
in response to inertia force of the counterweight, said resilient supporting
` means being independent of said connecting means.
Brief Description of the Drawings
, Fig. 1 is a diagrammatic view in partial section of
a work vehicle having the apparatus of this invention; and
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Fig. 2 is a view taken along line II-II of Fig. 1.
Detailed Description
.eferring now to Fig. 1 of the drawing, a vehicle
such as a lift truck 10 includes a frame assembly 11 carried
by front and rear wheels 12 and 13, respectively. The frame
assembly includes a hood 14 having an end portion 16 and a
maln frame 17 having an end portion 18 extending rearwardly
beyond the rear wheels. The hood 14 is suitably releasably
connected to the frame in the usual manner. A counterweight
19 is positioned ad~acent the end portion of the hood. The
counterweight can be of any known construction and can have
passages partially shown at 21 extending therethrough for air
flow to or from a radiator 22.
A means 23 is provided for attaching the counter-
weight 19 to the end portion 16 of the hood 14 of the frame
assembly 11 to permit limited up and down movement thereof
relative to the frame assembly 11. The means includes two
palr of vertlcally spaced llnks 24, 26 and 24', 26' each
llnk havln~ flrst and second end portlons 27, 28. Each pair
Of llnks ~P~ posltioned on a respectlve side of the vehicle
with llnk 24 being spaced above the link 26. The first end
portions of the llnks are pivotally connected to the end
portion 16 of the hood 14 by pivot pins 29. The second end
portions of the links are pi~otally connected to the counter-
1 25 wel~ht 19 by pivot pins 31. It will be seen from the drawing
`~ that the arrangement of 11nks is such that they constitute a
parallelogram llnkage assembly.
A resilient supporting means 35 is mounted on the
I end portion 18 of the main frame 17 and is attached to the
`' 30 counterweight 19. The resilient supporting means is of a
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construction sufficient for resiliently supporting the
counterweight and for cushioning shock loads exerted on the
main frame due to the inertia force of the counterweight.
The resilient support means of the present disclosure includes
a fluid ~ack 36 having a cylinder 37 pivotally connected to
the end portion 18 by a pivot pin 38. A piston 39 is slidably `
disposed within the cylinder and a piston rod 41 has one end
attached to the piston in the usual manner with its other
end pivotally connected to the counterweight at a pivot 42.
Preferably, a pair of coil springs 43 and 44 are positioned
within the cylinder on opposite sides of the piston 39 and
resillently resist the retraction or extension of the piston
rod relative to the cylinder.
Alternatively, the coil springs 43 and 44 can be
deleted and the fluid jack 36 connected to an accumulator
for cushloning the retraction of the piston. Also, another
form of resilient supporting means may include a coil spring
or resilient elastomer positioned between the end portion 18
Or the frame 17 and the counterweight 19 in combination with
a shock absorber to dampen the oscillatory movement of the
counterweight.
A means is provided for pivotally connecting the
counterweight 19 to the rearward end portion 18 of the frame
11 so that the counterweight and hence the hood 14 can be
pivoted in unison relative to the frame between a first
`3 position at which the hood is seated on the frame as shown, and
a second position at which the hood is spaced from the frame.
~he means can be, for example, a laterally extending bore 46
formed in the counterweight, a bore 47 formed in the rearward
~ 30 end portion 18 of the frame and a pin, not shown, insertable
i into the bores 46 and 47.
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In the operation of the lift truck, when the rear
wheels 13 of the lift truck 10 contact a bump, for example a
rock, the immediate reaction is for the wheel and frame 17 to
move upward over the bump. ~owever, the counterweight acts
against the spring 44 which yields under the inertia force
of the counterweight permitting relative movement between the
counterweight and the frame. This cushions the shock loads due
to the inertia force of the counterweight and will minimize
the transmission of shock loads to the frame.
To prepare the truck for moving the hood 14 and
counterweight 19 to the second position, the piston rod 41 of
; the fluid ~ack 36 is retracted thereby lowering the counter-
wieght 19 relative to the hood. The counterweight will travel
in an arcuate pathway about the pins 29 and the bore 46 will
eventually be positioned in alignment with the bore 47. The
pin is then inserted lnto the bores 46 and 47 forming a
pivotal connection between the counterweight and the rearward
end portlon 18 of the frame. The means releasably connectlng
the hood to the frame are then released. Finally, the piston
rod 41 of the fluid ~ack 36 is extended causing the counter- t
weight to pivot about the pin in the bores 46 and 47. By virtue
o~ the hood being connected to the counterwelght, lt ls also
plvoted ln unlson wlth the counterwelght about the pin to the
second position. At the second position, the hood is spaced
from the frame so that the engine and related components are
readlly accesslble.
To return the hood 14 and counterweight 19 to the
. flrst position, the above sequence of events ~PC reversed.
Other aspects, ob~ects and advantages of this
invention can be obtained from a study of the drawings, the
disclosure and the appended claims.
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