Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
- The invention has as a general obJect the provision of
a powered ~ork llrt truck~ the fork tines of which can be posi-
tioned in elongated sockets carried by a motor truck and power
applied to the fork, the power having a downward movement whereby
the remainder of the fork lift vehicle is elevated to permit the
fork lift vehicle to be transported by the motor truck with the
fork lift vehicle out of contact with the road surface.
Another obiect of the invenkion is to provide a fork
lift vehicle of the class described above with a pair of forward
wheels which, in the normaI operation of the fork lift~ lie
laterally outwardly with respect to the fork and its tines and
wherein these ~orward wheels can be displaced rearwardly a~ least
to a point ad~acent the rear portion of the rork so that the
tines can be freely inserted in the sockets on the motor truck
without interference from said forward wheels. It would be poor
design to permanently locate the forward wheels ad~acent the
rear of the fork because it would greatly limit the load capacity
of the fork. ~urthermore, with the forward wheels displaced on a
transverse line approximately midway of the length of the fork
tines~ heavy loads can be handled without requiring a heavy
counterweight on the rearward portion of the fork lift vehicleO
Another object of the invention is to provide a fork
life vehicle with rearwardly retractable forward wheels wherein
one Or the ~orward wheels can be retracted in truck loading
operations where the retracted wheel, if left in its forward
position~ would interfere with a rear truck wheel and prevent
proper maneuvering of the rork lift vehicle to a position for
depositing its load on the truck bed.
Other objects and advantages of the invention will more
fully appear from the following description in connection wlth
the accompanying drawings:
Fig4 1 is a side elevational view of a fork lift vehicle
embodying one form o~ the invention;
Figo 2 is a front e~evational view of the ~ork li~t
vehicle;
F-lgu 3 is a horizontal sectional view taken approxi-
mately on the line 3-3 O:e Fig~ l;
Fig. 4 is an enlarged detail taken approx-lmatelylon the
line 4-4 of Fig~ 3;
Figo 5 is a horlzontal longitudinal sectional view
taken approximately on the line 5-5 of Fig~ 4;
Fig. 6 is an enlarged detail showing the ri~ht hal~ of
the structure in Fig~ 5 with the sub-~rame locking bol-t in an
alternate posltion;
Fig 7 is a side elevational view of the fork lift
vehicle with its ~orward wheel assembly shown in forwardly dls-
posed and retracted positions in broken and rull lines respec-
tively~ and showing the fork in broken and ~ull lines to illustrate
the manner in which the ~orward wheel assembly is elevated and
retracted and the fork is positioned for reception in suitable
sockets on the rear of the motor truck;
Fig. 8 is a side elevational view with portions broken
away of the fork lift vehicle in its secured position for trans-
portation in an elevated position by a motor truck;
Flg. 9 is a sectional vlew taken approximately on the
line 9-9 of Figo 85
Fig. 10 is an enlarged detail of the manner in which the
rear sub-frame for each forward wheel and auxillary whee~ is
pivotally supported for retraction from its ~orward posltion.
Figu 11 is a side elevational view of a fork 11ft
vehicle showing a different form of retractable forward wheel
structure;
Fig~ 12 is a view of the structure in Figo 11 with the
forward wheels retracted and the fork lift vehicle supported at
the end of a truck chassis.
The device of Figso 1 through 10 includes a fork lift
vehicle 14 having longitudinal frame side members 16 and one or
more cross members, a forward cross member being shown at 18. A
pair of vertical fork guide frames 20 extend upwardl.y ~rom
adjacent -the forward cross frame member 180 Each vertical guide
frame 20 is pivotally connected at 22 to one each o~ a pair of
upwardly and rearwardly extending brackets 24 welded to the cross
frame 18 as indicated at 26 in Fig. 2. The lower ends of the
vertical guide frame members 20 are connected by a cross member
28. The vertical frame members are connected at vertical~y
spaced points by cross members 30 and 320 Connected to the
lower vertical ~rame cross member 28 as indicated at 34, is the
lower end of a hydraulic cylinder 36 into which extends a piston
rod 38 having the conventional piston not shownO '['he lower end
of the cylinder 36 is provided with a hydraulic line connection
40 for the admission of pressurized hydraulic fluid beneath the
piston and the cylinder 36 and an upper connection 42 is pro-
vided for pressurized hydraulic fluid which acts against the top
of the piston in the cylinder 36. Thus~ both the upward and
downward skrokes of the piston rod 38 are power strokes.
The upper ends of the piston rod 3~ is connected to a
cross piece 44 whose ends are suitably secured to the upper ends
of a pair of spaced tubes 46 which as shown in Figo 3, are pro-
vided with rollers 48 rotating in the vertical stationary frame
members 20. Any suitable number of rollers 48 can be used at
vertically spaced points along their respective tubes 46. Short
forwardly disposed webs 50 connect the vertical tubes 46 with a
pair of vertically spaced fork cross members 52 and 54. The
outer ends of the fork cross members 52 and 54 are connected by
plates 56 and to each plate is welded or otherwise suitably
secured thereto a vertical portion 58 of a fork member 60g and
each fork member also including a horizontal tine 62.
The cross piece 30 extending between the vertical ~rame
members 20 is pivotally connected at 64 to a piston rod 66
extending into a hydraulic cylinder 68 whose left end is pivot-
ally connected at 70 to the top 72 o~ a fork li~t vehicle houslng
74 within which is located a hydraulic pump and reservoir) all
conventionally indicated by broken lines at 76, these being con-
ventional parts of a fork lift mechanismO Supported by the
housing 74 is a seat 78 and a steering wh~-el 80, and such other
: controls as are necessary to operate the fork lift vehicle.
These controls are not shown because they also are conventional
and well known in the artO
The cylinder and piston unit 68, 66 connected between
the housing 74 and the vertical frame members 20 are used to tilt
said frame members 20 and the fork mechanism so that the fork
members 60 and their tines 62 can be tilted somewhat as necessary
in the engagement and disengagement of articles, such as pallets,
and also to permit the .~ork to be tilted rearwardly sl:lghtly when
carrying a load which might otherwise tilt and fall forwardly
~rom the forkO
The rear of the fork lift vehicle is supported centrally
in a transverse direction by a single rear wheel 82 which is con-
nected by a chain 84 to a hydraulic motor 86, the latter beingdriven by the usual motor and main hydraulic pumpO The manner
in whlch the slngle rear wheel 82 is steered is also not illus-
trated since that mechanism is also quite conventionalO
On each side of the forward portion o~ the fork lift
vehicle is a wheel 900 Each wheel 90 is mounted on a stub axle
92 carrying a gear 940 A chain 96 drives the gear 94 from a
driving gear 98 on a hydraulic wheel motor lOOo The stub axle
92~ the wheel motor 100 and the respective gears are all sup-
ported by a sub-~rame 102 which is pivotally connected at 104 to
the forward portion o~ its respective main frame side member 16
The stub frame 102 as shown in Fig 5 has an of~set
rearward extension 106 which is mounted on the sub-frame pivot
104v The o~fset 106 is secured to the sub-frame 102 by welding
indicated at 108 in Fig. 5 so that said sub-~rarne 102 and off'set
rearward extension 106 are in e~ect a sin~le rigid structure~
Mounted in the sub-frame offsek 106 is a bearing 110 in which is
a stub sha~-t 112 which carries on its outer end an auxiliary
wheel 114.
When the sub-frame 102 is in its downward and forward
position as illustrated in Fig. 5, a pin 116 which prot.rudes
rearwardly from the rear end of the main sub-frame 102 lies in a
groove 118 in a ~orward end piece 120 in the main side frame 160
This pin and groove arrangement assists the sub-frame pivot 104
in securely holding the sub-frame in its forward position and
agalnst undue lateral shi~tingO
The forward side portion o~ the main ~rame 16 is pro-
vided with a hole 122 which matches a hole 12L~ in one side of
the sub~frame rearward extension 106 and matches with a hole 125
in the outer side o~ the sub-frame extension, Said extension 106
has one end o~ a sleeve 128 welded thereto as shown in Figo 5.
Extending through sleeve 1.28 is a locking bolt 130 which extends
through the holes 126 and 124 in the sub-frame extension and the
coinciding hole 122 in the side of the ~orward portion of' the
main frame member 160 Within the sleeve 128 is a spring 132 whose
outer or lower end as viewed in Fig. 5J iS anchored in the sleeve
1280 The inner or upper end o~ the spring is movable outwardly
in the sleeve 128 with the bolt 130 by reason o~ a pin 13~ which
is mounted in the bolt 130 and engages a convolution o~ the
springO me bolt 130 extends outwardly of the sleeve 128 and is
provided with a pull handle 1360 It will be seen that when the
handle 136 is pulled to pull the pin 130 ~rom the hole 122 in the
side of the forward end o~ the main frameJ the sub-~rame 102 and
lts rearward extension 106 can be swung upwardly and rearwardly
relative to the main frameO In order to retain the bolt ].30 in
its retracted position, the pin 134 has its outer end riding in
a slot 138, said slot having an ang].ed outer end in the manner o~
a bayonet slot 50 that when the bolt 130 is retracted as stated
above to the point where the pin 13l~ is at the outer end of the
slot 138, a slight counterclockwise turn of the bolt handle 136
will ].odge the pin in the angled end of the slot and releasably
hold the bolt 130 in its retracted position. Referring to Fig, 7
the sub-frame 102 has been released through manipulation of the
bolt 130 and swun~ from its roughly horizont;al forwardly dis-
posed pos:ition, indicated in broken lines~ t;o an upwardly and
somewhat rearwardly directed position shown in full ].ines~ In
order to accomplish this~ the fork 60 must be lowered into con-
tact with the ground and hydraulic force applied through the
conduit 42 at the upper end of the vertical cylinder 36. This
creates a downward push on the fork sufficient to elevate the
forward portion of the fork lift vehicle and more particularly
the forward wheels gO. The fork in this position is shown in
broken lines in Figo 7~ As the sub-frarne 102 and wheel 90 is
swung upwardly about the pivot 104~ the auxiliary wheel 114 will
be swung downwardly in a counterclockwise direction until it
engages the ground, or the fork can be forced downwardly to lift
the vehicle slightly more than shown in Fig. 7 until the sub-
frame 102 is swung to the full line position and then the fork
raised sufficiently for the auxiliary wheel 114 to engage the
ground in a vehicle supporting position. It will be noted that
in this position illustrated i.n Fig. 7~ the sub-frame 102 has
been swun~ rearwardly over vertical dead center so that the
weight of the fork lift vehicle on auxiliary wheels 114 will
maintain the sub-frame 102 in its rearward over center posi-tionO
lt will be seen that the wheels 90 in their retracted
position are ad~acent the rear of the fork 60 and more speci-
fically are actually rearward of the fork constructlon; theauxiliary wheels lie in a vertlcal plane also adjacent the rear
of the fork 604 This leaves the fQrk tines 62 e~tendin~ for-
wardly of any other portion of the fork lift vehicle, Ther~fore,
the ~ork can be raised to the full line position of Fig. 7 with
the tines 62 in alignment with tubular sockets 140 wh-lch are
mounted on inverted U-shaped ~upports 142 and 144 which extend
downwardly from the underside o~ the truck bed 146~ When the
tines 62 are aligned with the tubular sockets 140, the fork
lift vehicle can be drlven forwardly under power from the single
rear wheel 82 and the tines run only into the sockets 140 as
shown in Figo 80 In this figure it will be seen that each socket
140 has an upward rear slotted portinn 148 to receive a portion
of the vertical ~ork member 58 to assist in preventing the fork
elements from tilting in the sockets 140~
When the fork tines have been located in the sockets
140, power is applied to the fork to tend to move it in a down-
ward direction~ Since the fork tines are located in the sockets
14OJ the fork cannot move downwardly and the result is that the
remainder of the f'ork lift vehicle is raised. This raised posi-
tion is illustrated in Fig. 8.
In order to insure the retention of the fork tines 62
in the sockets 140 a winch 150 is mounted on each side of the rear
end of the truck bed 146~ the winch being rotated by a suitable
handle 152 on the winch shaft 154. A ratchet 156 and a suitable
pawl (the latter not shown) releasably secures the winch in the
customary manner. A cable 158 on the winch has an eye 160 on
its free end to permit the cable to be secured to a hook 162,
there being one of each cable and hook and the hook being located
on the rear portion of the main frame 16~ In Figs~ 11 and 12
there is illustrated a modification wherein forward wheels 164
each carried by a horizontal square shaft 166 are sli~able fore
and aft in a square tubing 168 mounted on the side of a fork lift
vehicle frame member 170, The forward end of the tube 168 term-
inates short of the forward end of the frame member 170 and the
square sha~t 166 which supports the wheel 164 is sufriciently long
to permit said wheel 164 to be extended to a vertical p:Lane which
intersects the fork tines 62. Carried on top of the square
tubi.ng 168 is a hydraulic cylinder 172 having pressure fluid
., connections 1.7~ which alternately serve as inlets and outlets so
that a piston (not shown) in the cylinder 172 and connected to a
piston rod 176 can retract the wheel 164 or move it forwardly to
the posîtion of Figo llo When the wheel is retracted, it lies at
the rear of the fork 60 so -that the fork tines 62 can be inserted
in their sockets 140 and the vehicle el.evat~ed to the position
of Figo 12 in the same manner as that described in connection
with the preceding embodimentO
From the foregoing it will be seen that this is a fork
lift vehicle which can be conveniently mounted upon the rear
portion of a motor truck for transportation without being re-
quired to tow the fork lift vehicle. It is provided with forward
working whee].s gO and in the other embodiment 16L~, which wheels
are located for~ardly of the rear of the fork body and generally
midway between the front and rear of~the hdrizontal tines~
These wheels are sturdy enough to support the loads for which the
fork lift vehicle was built. These wheels can be retracted and
the ~ork lift vehicle supported by rearwardly disposed auxiliary
wheels which need be strong enou~h only to support the unloaded
` fork lift vehicleO These auxiliary wheels permit maneuvering
of the vehicle to a position where the fork tines are in an
elevated position~ aligned with the tine-receiving sockets
carried by the motor truck.
It is important to note that in both embodiments of the
invention it is possible to retract one of the forward pair of
wheels so that the fork lif-t vehicle can maneuver close to the
rear corner of the t:ruck bed ~or unloading a ~.oaded pallet or
the like~ While it is not possible to travel any distance with
one of the forward wheels retracted and a heavy load on the fork~
the device is capable of displacing the load from the truck to
the fork lift vehicle by extending the retracted wheel while
~ ~;2;~ ~
removing the weight from an area on the truck bed where the
truck wheels interfere with the ~ront wheels of the fork lifto
It will o~ course be understood that various changes
can be made in the ~or~/ details, arrangement and proportions of
the various parts without departing rrom the scope o~ our inven-
tion.
