[0001] The present invention relates to a truck-mounted forklift truck. Such a truck-mounted
forklift is usually used in combination with a truck for thereby loading and/or unloading
the cargo space of such a truck.
[0002] Truck-mounted forklifts are known in practice which are brought along by a truck
in order to enable independent loading and/or unloading. Such a truck-mounted forklift
is usually provided here with mounting elements whereby the truck-mounted forklift
can be mounted on the cargo space, particularly on a truck, and can be brought along
by such a truck. The forks of the truck-mounted forklift serve to pick up and/or set
down the cargo.
[0003] Such truck-mounted forklift trucks are provided with a number of wheels, at least
some of which are usually mounted on extendable wheel arms. The minimum overhang length,
i.e. the space necessary behind the truck for mounting of a truck-mounted forklift
to be brought along, can hereby remain limited. A problem is here that the extending
of the wheel arms for use reduces the robustness of the truck-mounted forklift due
to for instance clearance occurring between the extendable parts of a wheel arm. This
may result in undesirable situations with additional wear and possibly even unstable
cargo on the lifting arms during use.
[0004] The present invention has for its object to provide a truck-mounted forklift truck
whereby the above stated problems are obviated or at least reduced, such that the
loading and/or unloading of a cargo space using a truck-mounted forklift can be performed
more efficiently.
[0005] This object is achieved with a truck-mounted forklift truck for loading and/or unloading
a cargo space according to the invention, wherein the truck-mounted forklift truck
is provided with:
- a frame provided with mounting elements configured to mount the truck-mounted forklift
truck on a truck provided with the cargo space;
- a set of forks for picking up and/or setting down a cargo during the loading and/or
unloading;
- one or more wheel arms arranged on the frame and provided with a wheel, wherein the
wheel arms are extendable, wherein the wheel arm is provided with a shaped guide configured
to align the wheel arm in lateral direction for aligned extending and retracting of
the wheel arm.
[0006] The truck-mounted forklift truck can be connected to a truck with cargo space or
loading space in simple manner by providing a frame with mounting elements. In this
manner a truck-mounted forklift can be brought along during transport and is thereby
immediately available for loading and/or unloading using the forks of the truck-mounted
forklift. Use need therefore not be made of a forklift truck at the location in question.
The truck-mounted forklift is preferably provided here with a mast and associated
drive in order to thereby further increase the utility of the truck-mounted forklift.
Using the wheels and associated drive the truck-mounted forklift can be displaced
over a ground surface, particularly during loading and/or unloading of a truck.
[0007] The truck-mounted forklift is preferably provided with a steering mechanism with
which at least some of the wheels are steerable. It is hereby possible to manoeuvre
the truck-mounted forklift in effective manner when displacing cargo. Such a steering
mechanism can take diverse forms, for instance with a gear rack construction or with
a steering/turning cylinder. By providing extendable arms the truck-mounted forklift
can take a compact form relative to the overhang length. This has the advantage that
the space necessary on the rear side of the truck during transport can remain limited.
This prevents loading space being lost due to the use of a truck-mounted forklift.
[0008] By providing a shaped guide the extending and preferably also retracting of the wheel
arms can be performed in controlled manner. The shaped guide according to the invention
is configured to align wheel arms in lateral direction for the purpose of extending
and preferably retracting thereof. By guiding the relative movement of the (sub-)parts
of the wheel arms undesired clearance in lateral direction is prevented or at least
reduced. This increases the robustness of the truck-mounted forklift as a whole. The
undesired movement of the cargo as a result of clearance in the wheel arms or sub-parts
thereof is hereby additionally prevented. This increases the stability of the cargo
during displacement with the truck-mounted forklift. This reduces the risk of accidents.
[0009] In addition, wear is reduced and preferably concentrated on the wheel arm guide by
the aligned extending and preferably retracting of the wheel arms and wheel arm parts
using the shaped guide. The lifespan of the wheel arm and thereby the truck-mounted
forklift is hereby increased. The maintenance costs are also reduced. A further particular
additional advantage is that inspection of possibly occurring wear is possible in
simpler manner owing to the concentration thereof, preferably on the shaped guide.
[0010] In a currently preferred embodiment the alignment in a vertical direction during
use is ensured by the own weight of the truck-mounted forklift. This provides for
alignment of the (sub-)parts of the wheel arm from the underside.
[0011] The lateral alignment is therefore brought about by the shaped guide. This has the
further advantage that relative tolerances for wheel arm parts need not be as precise.
This simplifies production and mounting. This is particularly advantageous if wheel
arms and wheel arm parts are manufactured from tubular profiles or bent plates. Such
production can take place in simpler manner, whereby the cost price of the wheel arms
in particular, and the truck-mounted forklift as a whole, can be limited.
[0012] The shaped guide is preferably provided with a guide groove. This guide groove can
be arranged in the outer wheel arm part or the inner wheel arm part. In a currently
preferred embodiment an inner tubular part is provided extendably on an outer tubular
profile. These two wheel arm parts are thereby provided extendably and retractably
relative to each other. The guide groove is provided on at least one of these two
parts. In a currently preferred embodiment the guide groove is provided on the inner
part and a correspondingly shaped part (of the shaped guide) is arranged on the internal
surface of the outer part. If desired, this can be attached as a separate part, of
another material if desired.
[0013] In a currently preferred embodiment the shaped guide is provided on the upper side
of the wheel arm, particularly on and/or between the sub-parts of the extendable wheel
arm. A further shaped guide is still more preferably provided on the underside of
the wheel arm. It is otherwise likewise possible to provide the shaped guide only
on the underside. Providing two separate shaped guides, respectively on the underside
and the upper side of the wheel arm, improves the guiding still further and intensifies
the above stated effects further.
[0014] A further advantage of providing a shaped guide as separate component, or at least
a part of a shaped guide as separate component, is that the shaped guide thereby preferably
also functions to concentrate wear and that mounting and removal of the shaped guide
is in addition made relatively simple. This makes maintenance and repairs considerably
simpler because it is for instance possible to remove and replace this component of
the wheel arm in simple manner. The guide is here for instance screwed fixedly to
the tubular profile.
[0015] A further advantage is that by using the guides no additional filling is required
on the sides between the separate sub-parts of the wheel arm. This simplifies production
and mounting and additionally reduces the resistance during extending or retracting
of the wheel arms.
[0016] In an advantageous embodiment according to the invention the wheel arm is formed
wholly or partially from two sub-parts which are mutually connected with at least
one lateral weld.
[0017] Providing at least one of the parts of the wheel arm from separate parts simplifies
production of the wheel arm.
[0018] Providing separate parts for a sub-part of the wheel arm achieves that, instead of
a tubular profile as starting material, it is possible to use sheet material as starting
material. This sheet material can be bent in relatively simple manner with for instance
an angle bending machine, after which separate parts are then mutually connected,
preferably with a longitudinal weld on the side of the wheel arm for thereby providing
said lateral weld. In a currently preferred embodiment such a weld is arranged on
the side of the inner sub-part of the wheel arm, since alignment is in a currently
preferred embodiment realized by providing the guides on the upper side and/or underside
of the wheel arm. Hereby, there is sufficient space for the weld on the side. This
even has the additional advantage that the weld can be completely welded through,
whereby the connection between the separate parts of the inner sub-part of the extendable
wheel arm in particular can be made extremely strong and robust.
[0019] In a further advantageous embodiment the guide groove is provided with a V-shaped
groove.
[0020] Providing a V-shaped groove results in a self-centering, i.e. self-aligning, effect
in that during the relative movement the separate sub-parts of the wheel arm are themselves
urged into the correct position, and are held therein, by the shape. This results
in an effectively guiding element.
[0021] The V-shaped groove is provided here with two legs which are arranged at an angle
in a range of 2-25°, preferably in the range of 5-20°. An effective guide groove,
which can be realized in simple manner, can hereby be provided. In a currently preferred
embodiment it is thus for instance possible to mutually connect two separate parts
of an (inner) sub-part of the wheel arm via two lateral welds and to provide them
with a shaped guide on the upper side and underside. The V-shaped groove can hereby
be bent in effective manner in an angle bending machine, which groove can thereby
also be realized sufficiently accurately.
[0022] In a currently preferred embodiment a V-shaped groove is provided both on the upper
side and the underside of the wheel arm. In such an embodiment the angle on the upper
side is for instance about 20°, and on the underside about 10°. It has been found
that a good stability for the wheel arm is obtained hereby. It will be apparent that
other angles are also possible according to the invention.
[0023] The shaped guide preferably comprises a separate guide plate which can be mounted
separately on for instance the inner side of the outer tube of the wheel arm. This
guide plate is preferably provided from a plastic material, such that the plastic
wear part is realized. As already stated above, this enables an effective use including
maintenance and repairs.
[0024] In a further advantageous embodiment the truck-mounted forklift truck further comprises
one or more load carriers configured to carry cargo during displacement of the truck-mounted
forklift in a lateral direction, and provided with a tilting mechanism for moving
the load carrier downward and an unfolding mechanism for simultaneously unfolding
a support.
[0025] Providing a tilting mechanism and an unfolding mechanism also enables a support to
be unfolded during lowering of the load carrier from a folded-up position. This has
the advantage that the overhang length remains limited. This makes transport with
the truck-mounted forklift according to the invention more effective.
[0026] The invention also relates to a truck comprising a cargo space and a truck-mounted
forklift truck as described above, wherein the truck is provided with coupling elements
configured to be able to couple the truck-mounted forklift to the truck in co-action
with the mounting elements of the truck-mounted forklift.
[0027] Such a truck provides the same effects and advantages as stated for the truck-mounted
forklift.
[0028] The invention further also relates to a method for loading and/or unloading a cargo
space of a truck, comprising the steps of:
- uncoupling the truck-mounted forklift truck from the truck;
- extending the wheel arms;
- loading and/or unloading the truck with the truck-mounted forklift truck; and
- retracting the wheel arms and coupling the truck-mounted forklift truck to the truck.
[0029] Such a method provides the same effects and advantages as stated for the truck-mounted
forklift truck and/or the truck.
[0030] By making use of the invention cargo can be transported in effective manner with
the truck-mounted forklift truck as described above. This is because the robustness
and stability are increased, such that dangerous situations are also avoided.
[0031] Further features, advantages and details of the invention are described on the basis
of preferred embodiments thereof, wherein reference is made to the accompanying drawings,
in which:
- figure 1 shows a view of a truck-mounted forklift truck in an embodiment according
to the invention;
- figures 2 and 3 show views of a wheel arm from the truck-mounted forklift according
to figure 1; and
- figures 4 and 5 show views of a load carrier in an embodiment of the truck-mounted
forklift according to the invention.
[0032] Truck-mounted forklift truck 2 (figure 1) is provided with frame 4, wherein front
wheel 6 and second front wheel 8 are arranged on the front side. Steered wheel 10
is provided on the rear side. In a first embodiment front wheels 6, 8 are provided
fixedly and in a second embodiment also provided steerably.
[0033] In the shown embodiment truck-mounted forklift truck 2 is provided with mast construction
12 with forks 14 for picking up and setting down cargo. In the shown embodiment truck-mounted
forklift 2 is further provided with cab 14 with seat 16 and steering system 18.
[0034] In the shown embodiment (figure 1) wheels 6, 8 are provided on the front side of
truck-mounted forklift 2, arranged on wheels arms 20. Two load carriers 22 are further
arranged in the shown embodiments.
[0035] In the shown embodiment wheel arm 20 is provided with a first sub-part 24 and second
sub-part 26 (figures 2, 3). In the shown embodiment the first sub-part 24 is embodied
as an outer tubular profile which is mounted fixedly on frame 4 of truck-mounted forklift
2.
[0036] In the shown embodiment (figures 2, 3) inner sub-part 26 is embodied as a tubular
profile which is slidable in first sub-part 24. In the shown embodiment wheel guide
28 is formed by the V-shaped groove 30, arranged in inner, i.e. in use front, sub-part
26 in longitudinal direction thereof, and guide 32 which is secured to fixed sub-part
24 of wheel arm 20. In the shown embodiment guide 32 is arranged on the upper side
of wheel arm 20, between sub-parts 24, 26. In the shown embodiment a second wheel
guide 34 with an inverse V-shaped groove 36 and second guide 38 is also provided on
the underside of wheel arm 20. Also provided is drive 40 which makes it possible to
extend or retract sub-parts 24, 26 relative to each other.
[0037] In the shown embodiment front sub-part 26 is provided from separate parts, particularly
upper part 42 and lower part 44 (figure 3). In this embodiment both parts are manufactured
using an angle bending machine and then mutually connected using weld 46. Weld 46
extends in the longitudinal direction on side 48 of wheel arm 20. In this shown embodiment
upper shaped guide 28 is therefore arranged on upper side 50 of wheel arm 20 and second
guide 32 on underside 52 of wheel arm 20. On sides 48 space 54 is available between
sub-parts 24, 26. This enables and/or simplifies production tolerances and welds 46.
In the shown embodiment guide 32, 38 is provided with a plastic material. If desired,
a wear indicator can be provided here which indicates whether guide 32, 38 has to
be replaced.
[0038] In the shown embodiment wheel guides 32, 38 are provided with two legs 56, 58 (figure
3). Legs 58 are provided at angle α to the horizontal. In the shown embodiment angle
α lies in the range of 2-25°. It will be apparent that other angles and shapes are
likewise possible according to the invention. In the shown embodiment legs 56, 58
are provided to fit substantially against respectively the upper side and underside
of sub-part 26. Wheel guides 32, 38 are as it were provided truncated by the truncation
at the position where legs 56, 58 converge in order to reduce friction, among other
things.
[0039] Load carriers 22 (figure 4, 5) carry the cargo particularly during the lateral displacement
of goods. During such a lateral displacement wheels 6, 8, 10 of truck-mounted forklift
2 are in the shown embodiment placed completely laterally, whereby the truck-mounted
forklift is displaceable in lateral direction B instead of in forward direction A.
This is applied particularly in the case of elongate goods. In such a case load carriers
22 then contribute to a greater stability in that, in the case of two load carriers
22, they are arranged at a greater mutual distance than forks 14 of truck-mounted
forklift 2. In the shown embodiment a load carrier 22 is secured to frame 4 of truck-mounted
forklift 2 using support 60. Support 60 is thereby mounted fixedly on truck-mounted
forklift 2. Carrier part 62 is rotatable around shaft 64. Using connecting rod 66
as unfolding mechanism, support 68 is folded down automatically when load carrier
22 is moved downward around rotation shaft 64 in rotation direction C. In the shown
embodiment support 68 is provided with foot 70. By making use of the tilting and unfolding
mechanism, wherein support 68 rotates around shaft 72, the necessary space for load
carriers 22 in a folded-up state is limited. There is hereby no unnecessary adverse
effect on the overhang length.
[0040] In the shown embodiment control of load carriers 22 takes place using cylinder 74.
Automatic folding down and folding up of load carriers 22 is hereby simplified for
a user. If desired, it is possible to perform such a movement manually.
[0041] During transport truck-mounted forklift 2 is usually connected to the rear side of
a truck and/or mounted on or onto the loading floor thereof in a manner known in practice.
This is usually possible without loss of cargo space or loading space of the relevant
truck or trailer. The forks of mast construction 12 are herein for instance inserted
into box beams of trucks. Optionally, support is found here on an additional frame
and/or truck-mounted forklift 2 is fastened to the truck using chains.
[0042] When the desired location is reached, truck-mounted forklift 2 is uncoupled from
the truck in known manner and then used to load and/or unload goods from the cargo
space of the truck. During use a user steers truck-mounted forklift truck 2.
[0043] During use the wheel arms are extended and placed in a position of use. Inner (front)
sub-part 26 of wheel arm 20 here performs a translating movement relative to the outer
sub-part 24 of wheel arm 20. The shaped guide guides the front sub-part during the
extending movement. When the wheel arm is retracted, a reverse movement is performed.
If desired, it is possible not to extend wheel arm 20, or not to extend it wholly,
during use. This has the advantage that it is possible to get close to cargo.
[0044] It will be apparent that different embodiments of truck-mounted forklift 2 are possible.
As stated, it is for instance possible to provide a plurality of steerable wheels
10, for instance also on the front side, in combination with shown wheels 6, 8. All
wheels are hereby preferably steerable. In such an embodiment front wheel 8 (figure
1) is for instance turned using a cylinder or, alternatively, with a separate turning
cylinder 30. Wheel 6, 8 is here operatively connected to a frame part which is rotatable
round a substantially vertical axis, or a rotation axis having at least a relatively
large vertical component. This also applies to front wheel 6.
[0045] It is further possible to provide mast construction 12 in other embodiments, for
instance with a so-called scissor mast.
[0046] The present invention is by no means limited to the above described preferred embodiments
thereof. The rights sought are defined by the following claims, within the scope of
which many modifications can be envisaged. It is thus for instance possible to manufacture
parts of truck-mounted forklift 2 from plastic and/or metal. It is also possible to
give truck-mounted forklift 2 a different lifting capacity, depending on the intended
application.
1. Truck-mounted forklift truck for loading and/or unloading a cargo space, the truck-mounted
forklift truck comprising:
- a frame provided with mounting elements configured to mount the truck-mounted forklift
on a truck provided with the cargo space;
- a set of forks for picking up and/or setting down a cargo during the loading and/or
unloading;
- one or more wheel arms arranged on the frame and provided with a wheel, wherein
the wheel arms are extendable, wherein the wheel arm is provided with a shaped guide
configured to align the wheel arm in lateral direction for aligned extending and retracting
of the wheel arm.
2. Truck-mounted forklift truck according to claim 1, wherein the shaped guide is provided
with a guide groove.
3. Truck-mounted forklift truck according to claim 1 or 2, wherein the shaped guide is
provided on the upper side of the wheel arm.
4. Truck-mounted forklift truck according to claim 1, 2 or 3, wherein the shaped guide
is provided on the underside of the wheel arm.
5. Truck-mounted forklift truck according to any one of the foregoing claims, wherein
the wheel arm is formed from at least two sub-parts which are mutually connected with
at least one lateral weld.
6. Truck-mounted forklift truck according to any one of the foregoing claims, wherein
the guide groove is provided with a V-shaped groove.
7. Truck-mounted forklift truck according to claim 6, wherein the V-shaped groove is
provided with legs at an angle in the range of 2-25°, preferably in the range of 5-20°.
8. Truck-mounted forklift truck according to any one of the foregoing claims, wherein
the shaped guide further comprises a guide plate.
9. Truck-mounted forklift truck according to claim 8, wherein the guide plate comprises
a plastic wear part.
10. Truck-mounted forklift truck according to any one of the foregoing claims, further
comprising one or more load carriers configured to carry cargo during displacement
of the truck-mounted forklift in a lateral direction, and provided with a tilting
mechanism for moving the load carrier downward and an unfolding mechanism for simultaneously
unfolding a support.
11. Truck comprising a cargo space and a truck-mounted forklift truck according to any
one of the foregoing claims, and further provided with coupling elements configured
to couple the truck-mounted forklift to the truck in co-action with the mounting elements
of the truck-mounted forklift truck.
12. Method for loading and/or unloading a cargo space of a truck, comprising the steps
of:
- providing a truck and truck-mounted forklift truck according to any one of the foregoing
claims;
- uncoupling the truck-mounted forklift truck from the truck;
- extending the wheel arms;
- loading and/or unloading the truck with the truck-mounted forklift truck; and
- retracting the wheel arms and coupling the truck-mounted forklift truck to the truck.