[0001] The invention relates to a mast truck according to the preamble of the appended claim
1.
[0002] In particular, the invention relates to reach trucks meant for warehouse operations,
said trucks being used for transporting containers, boxes and similar items to warehouse
racks and for unpacking said items from the racks. The features required of these
trucks are agility in operation, small size, particularly small dimensions in the
moving direction of the machine, and good visibility for the driver.
[0003] A mast truck suitable for warehouse operation is a truck moving on at least three
wheels and provided with a mast structure comprising a fixed mast structure, as well
as two movable carriages and a lifting carriage. The mast and carriages are rectangular
structures formed of vertical profiles and transversal supports welded thereon. The
mast is connected to the truck either in stationary fashion or so that it can be inclined
around an axis. Inside the mast there is arranged a moving carriage, an intermediate
carriage that moves vertically along the mast profiles by intermediation of guiding
wheel bearings. Inside the intermediate carriage there is arranged another moving
carriage that moves with respect to the intermediate carriage by intermediation of
guiding wheel bearings. The lifting carriage moves in a similar way with respect to
the top carriage. Hydraulic cylinders are generally used for lifting and lowering
the carriages. In the first operational step of the mast truck, i.e. the free lifting
step, the lifting carriage is lifted to the top end of the top carriage, and in the
next step, the lifting step proper, the intermediate carriage and the top carriage
are lifted to their top positions.
[0004] The thrusting motion of the cylinders, i.e. jacks, as well as the motion of the carriages
to their top positions cause power torques that should be more or less in balance.
[0005] Known free-lifting mast trucks generally include at least three lifting jacks, two
at the sides of the mast structure and one in the middle, in which case both the middle
jack and the side jacks obstruct the driver's range of vision when the driver is sitting
behind the mast structure. Other elements obstructing the view are the power transmission
means of the jacks, pipes connecting the hydraulic cylinders and tubes required by
various auxiliary devices.
[0006] The critical measure is the length of the mast truck. The longer the mast truck,
the larger its turning radius, and the more difficult it is to drive the truck in
narrow aisles in between the racks. Here the term 'mast truck length' means its length
dimension in the driving direction.
[0007] The object of the invention is to reduce the length of a reach truck, and thus also
to reduce the truck's turning radius, and to improve the visibility through the mast
structure while keeping the power torques in balance.
[0008] From the patent GB-A-2 264 282 or from GB-A-2 236 091 there is known an arrangement
where the gap between the mast structures is open, and the lifting operation is carried
out by two jacks only. The jacks are, however, placed behind the mast when seen in
the driving direction, which means that the truck has a normal length. Owing to the
placing of the jacks, the power transmission chains proceed in a way that disturbs
visibility and increase the blind area. In the mast truck according to said invention,
the power torques created during the lifting operation are not sufficiently balanced
from the point of view of ideal operation.
[0009] The object of the invention is achieved by realizing the lifting operation of the
truck by means of two jacks that are placed in the transversal direction of the truck,
i.e. transversally to the driving direction, at the sides of the mast structure, and
by turning the power transmission wheel provided at the end of the free-lifting jack
for 90°, so that the direction of its axis is perpendicular to the driving direction.
In order to balance the power torques, the power transmission wheels attached to the
upper structure of the intermediate carriage are arranged, with respect to each other
and the axis of symmetry, so that a balance of torque is achieved.
[0010] By placing both jacks outside the mast structure, the power transmission means can
be aligned, so that the blind areas are minimized. Likewise the tubes required by
the auxiliary devices can be arranged so that they do not obstruct the view.
[0011] The most important novel features of a swinging mast truck according to the invention
are apparent from the characterizing features set forth in the appended claim 1.
[0012] An essential factor for reducing the length of the mast truck and for minimizing
the blind areas is the placing of two jacks at the sides of the mast structure and
the turning of the power transmission wheel, located at the free end of the free-lifting
jack piston, to be parallel with the driving direction, so that the wheel surface
is turned by 90°. This means that the mast truck dimensions are reduced in the driving
direction. The direction of the power transmission wheel located at the free end of
the free-lifting jack requires that the power transmission band is respectively turned
for 90° before it reaches the transmission wheel at the fixed end of the jack. This
is arranged by means of a band turning element which is arranged in said band, in
the section between said wheels.
[0013] In the structure according to the invention, the power transmission wheels attached
to the upper structure of the intermediate jack can be arranged, with respect to each
other and to the symmetry axis, so that during the lifting step the power transmission
chains passing through the power transmission wheels create power torques that are
in balance. This is something that a man skilled in the art can do on the basis of
his experience.
[0014] Owing to the structure according to the invention, the tube or tubes of the mast
truck can be arranged to proceed outside the driver's field of vision, mainly along
the same path as the power transmission chains.
[0015] A few preferred embodiments of the invention are explained in more detail below,
with reference to the appended drawings, where
- figure 1a
- illustrates the mast structure of a mast truck according to the invention, seen in
a vertical illustration from behind, from the driver's point of view and as extended
to the working position,
- figure 1b
- illustrates the top part of figure 1a, cut at the line 1ab and shown in an enlarged
scale;
- figure 1c
- illustrates the bottom part of figure 1a, cut at the line 1ab and shown in an enlarged
scale;
- figure 2
- illustrates the mast truck according to figures 1a - 1c, seen in a larger scale and
in the initial position;
- figure 3
- illustrates the mast truck according to figure 1, seen in a larger scale in a vertical
illustration and in the same direction after the free-lifting step, when the lifting
carriage is lifted to the top end of the top carriage;
- figure 4
- illustrates the mast truck according to figure 1, seen in a vertical illustration
from the side and in the rest position;
- figure 5
- illustrates the mast truck according to figure 2, seen in a top-view illustration;
- figure 6
- illustrates the mast truck of figure 2, seen in a 3D illustration, in a smaller scale
and in the initial position;
- figure 7
- illustrates the band turning element in a 3D illustration, seen in a larger scale;
and
- figure 8
- illustrates the top part of a mast truck according to another embodiment, seen from
the driver's point of view and in the initial position.
[0016] The embodiment illustrated in the drawings represents a mast structure that is attached
to the truck. The truck housing is supported by at least three wheels, at least one
of which is a traction wheel.
[0017] In figure 1a, there are seen three separate mast sections I, II and III that are
roughly of the same height. In the width direction of the truck, the mast sections
are installed in a telescoping fashion and connected slidably to each other. Each
section I, II, III of the mast structure is made of vertical profile pairs 10, 11
and respectively 12, which are welded together at the bottom and top ends by means
of transversal supports 4 and 5, 6 and 7, and respectively 8 and 9. The mast I is
connected to the truck either in a stationary fashion or so that it can be inclined
in the direction of the lengthwise axis of the truck, i.e. in the driving direction.
The middle mast section is the intermediate carriage II that moves vertically by intermediation
of guide wheel bearings with respect to the profiles 10 of the mast section I. The
innermost mast section is the top carriage III, which moves in similar fashion in
the profiles 11 of the intermediate carriage II. The lifting carriage is realized
in the form of a fork lift 19, figure 6, and it moves with respect to the top carriage
III. The profiles 12 and 11 of the top and intermediate carriage III, II, as well
as the profiles 10 of the mast I are I-profiles. As an alternative, the profiles of
the mast I can be U-profiles.
[0018] The mast structure, figure 1a, comprises two hydraulic cylinders, 14 and 20. The
cylinders operate in two steps. The first operation step is carried out by the free-lifting
jack 14, which lifts the fork lift 19 to the top end III of the fork lift 19, whereafter
another lifting jack 20 pushes the intermediate carriage II upwards in the vertical
direction. At its top end, the free-lifting jack 14 is attached to the top support
7 of the intermediate carriage, in which case the piston 14
m thereof performs a downwardly thrusting direction and shifts the fork lift 19 to
the top end of the top carriage III, figure 3. The motion of the piston is transmitted
by means of power transmission elements comprising a chain 29, a chain wheel 13 located
at the free end of the piston 14
m of the free-lifting jack, a chain turning element 15, figure 7, chain wheels 16 and
17 attached to the top support 7 of the intermediate carriage II and a chain wheel
18 attached to the top support structure 9 of the top carriage III. In the power transmission
chain 29, there is used a chain turning element 15 that turns the chain coming from
the chain wheel 13 by 90° with respect to its lengthwise axis, so that the chain enters
the chain wheel in the correct position, i.e. at an angle of 90° with respect to the
chain wheel 1, figure 6. At the other end, the chain 29 is fixedly attached to the
mast top support structure 5, of which the cut sections 5 are illustrated in the drawings.
The chain passes around the chain wheel 13 located at the free end of the piston 14
m of the free-lifting jack 14, around the chain wheels 16 and 17 located in the top
support structure 7 of the intermediate carriage II and via the chain wheel 18 located
in the top support structure 9 of the top carriage III to the fork lift 19. The chain
alignment has been selected so that it causes a minimal blind area, figure 1a.
[0019] The free-lifting piston 14
m and the chain 29 moved thereby cause a counterclockwise torque at the top end of
the intermediate carriage II, while the chain passes over the chain wheels 16 and
17. Said counterclockwise torque is balanced in the top support structure 7 of the
intermediate carriage II by means of chains 25 and 26. One end of the chain 25 is
attached to the top support structure 5 of the mast I and proceeds via the chain wheel
21 to the bottom support structure 8 of the top carriage III. The chain wheel 21 is
turned by 90° with respect to the chain wheels 16 and 17, figure 6, so that its axis
is transversal to the truck driving direction. One end of the chain 26 is attached
to the top support structure of the mast I and proceeds over the chain wheels 22 and
23, attached to the top support structure 7 of the intermediate carriage II, to the
bottom support structure 8 of the top carriage, being attached thereto at the other
end, figures 2 and 3. The fastening points of the bottom ends of the chains 25 and
26 in the bottom support structure 8 of the top carriage III are arranged so that
in the bottom position of the mast, the chain alignments proceed between the profiles
10 and 12, so that the blind area is minimal. On the other hand, the fastening points
of the top ends of the chains 25 and 26 in the top support structure 5 of the mast
I are asymmetric with respect to the central axis A-A, figure 1c. Hence the asymmetric
positioning of the chain wheels 21 and 22, 23 causes a clockwise torque for the intermediate
carriage II.
[0020] Thus the chain wheel 21 fits in a small space transversally to the driving direction,
and does not increase the blind area in the driver's view. The fastening points of
the ends of the chain 25 in the top support structure of the mast I and respectively
in the bottom support structure 8 of the top carriage III are located directly underneath
the chain wheel 21, and consequently do not enlarge the blind area. The chain 2 in
turn is at one end attached to the top support structure 5 of the mast I, mainly at
the same distance from the central axis A-A of the mast I as the chain 25, and it
passes around the chain wheels 22 and 23 attached to the top support structure of
the intermediate carriage II to the bottom support structure 8 of the top carriage,
to outside the second jack with respect to the central axis A-A of the mast truck,
according to figures 1a, 2 and 3. Thus the asymmetric positioning of the chain wheels
21, 22 and 23 causes in the intermediate carriage a torque in the opposite direction.
[0021] The chain 26 passes over both wheels 22, 23. The chain wheels 22 and 23 can also
be replaced by a single chain wheel with a larger diameter than the wheels 22 and
23, figure 8.
[0022] The bottom end of the jack 20 that performs the second step in the lifting operation
is attached to the mast structure I, and the top end thereof is attached to the top
support structure 7 of the intermediate carriage II. The jacks 1 and 20 are hydraulically
coupled in series by means of a pipe 2, figure 5. The area of the piston 14
m of the jack 1 is larger or at least equal to the area of the piston 20
m of the jack 20. The ratio of the areas is utilized for controlling the order of the
operation of the jacks, so that the free-lifting jack is operated first owing to its
smaller weight level.
[0023] The continuous operation of the mast structure is best understood from figures la-3.
In figure 2, the mast is in its initial position, i.e. in the rest position. Now the
chain turning element 15 is near the chain wheel 16 located in the top support structure
7 of the intermediate carriage II. In the first step of the lifting operation, the
piston of the free-lifting jack 14
m moves vertically downwards, at the same time moving the chain wheel 13 attached thereto.
Over the chain wheel, there passes the free-lifting chain 29 which is at one end attached
to the top support structure 5 of the mast I, and at the other end to the fork lift
19. The motion of the chain wheel lifts the fork lift 19 in the proportion of the
motional lengths 1:2, i.e. the length proceeded by the fork lift is doubled with respect
to the length proceeded by the chain wheel 1. At the end of the stroke of the piston
14
m of the free-lifting jack 14, the situation corresponds to figure 2. The chain turning
element 15 has proceeded to the vicinity of the chain wheel 1 attached to the piston
14
m of the free-lifting jack. The chain wheels 16 and 17 cause a counterclockwise torque
in the top support structure of the intermediate carriage II. In the next step of
the lifting operation, the piston 20
m of the lifting jack 20 moves upwards, at the same time moving the intermediate carriage
II and the free-lifting jack 14 attached thereto, in the proportion 1:1 of the motional
lengths. The chain wheels 21, 22 and 23 attached to the top support structure of the
intermediate carriage II transmit the stroke of the piston 20
m of the lifting jack 20 to the top carriage III, thus lifting the carriage to the
top position. In the second step of the lifting operation, the asymmetric alignment
of the power transmission chains 25 and 26 causes a clockwise torque in the intermediate
carriage II, and thus balances the counterclockwise torque created during the first
step of the lifting operation. At the end of the stroke of the second lifting jack,
the chain turning element 15 has moved to the vicinity of the chain wheel 1, located
in the top structure of the intermediate carriage II, figure 2. Thus the chain turning
element 15 moves back and forth between the extreme position of the initial position,
located near the chain wheel 16, to the extreme position according to the truck working
position, which is situated near the chain wheel 13.
[0024] The return of the mast structure to the rest position takes place in reversed order.
[0025] The controlling of the tubes 27, figure 3, can be realized so that it causes as little
blind area as possible. The tubes are fixedly attached to the top support structure
5 of the mast I, wherefrom they pass via the chain 13, 16, via the tube wheel 28 and
the chain wheel 18 to the fork lift 19. At the chain wheel 13, the tubes proceed in
parallel with the chain 29, but at the chain wheel 16 they proceed over it, while
the chain 29 passes underneath; then they pass underneath the tube wheel 28 attached
to the top support structure 7 of the intermediate carriage II, so that they are directed
on top of the free-lifting chain 29 according to figure 2.
[0026] The minimum length of the mast structure is formed of the dimensions of the profiles
10, 11 and 12. The length of the mast structure according to the above described embodiment
is formed, in addition to the profiles 10, 11 and 12, of the width of the power transmission
chain 25, figure 5. The space taken up by the chain 29 in the lengthwise direction
of the mast can be reduced by shifting the location of the free-lifting jack 14 somewhat
forward in the proceeding direction of the truck. Therefore the profiles 10, 11 and
12 are worked at the top end, so that the chain wheels 16, 17 and 18 can be placed
in line with the free-lifting jack.
[0027] The extendable mast structure specified above, comprising two moving carriages, is
not restricted to the figures and described embodiments exclusively, but it can be
modified within the scope of the appended claims and according to the know-how of
a man skilled in the art.
1. A mast truck, particularly a reach truck meant for warehouse operations, comprising
- a mast structure including a fixed mast (I) and at least two moving carriages (II
and III), one of which is an intermediate carriage (II) and movable vertically with
respect to the fixed mast (I), and the other is a top carriage (III) and movable vertically
along the intermediate carriage (II), and further including a lifting carriage (19),
which is supported by the top carriage (III) and movable vertically along the top
carriage;
- two hydraulic cylinders (14, 20) for moving the carriages (19, II, III), the first
of which is a free-lifting jack (14), causing the lifting carriage (19) to be shifted
to the top end of the intermediate carriage (II), and the second is a lifting jack
(20), causing the intermediate carriage (II) and the top carriage (III) to be shifted
to their top positions, while the free-lifting jack (14) is arranged to operate first,
and the lifting jack (20) is arranged to operate thereafter;
- and band-like power transmission elements (29, 25, 26), passing through transmission
wheels (13, 16, 17, 18, 21, 22, 23) and transmit the thrusting motions of the cylinder
pistons (14m, 20m) to the carriages (II, III, 19);
so that the first band-like power transmission element (29), which is arranged to
transmit the thrusting motion of the piston (14
m) of the free-lifting jack, is at one end attached to the top support structure (5)
of the fixed mast (I), passes around the wheel (13) located at the free end of the
piston (14
m) of the free-lifting jack (14) and further passes around the wheels (16, 17), attached
to the top support structure (7) of the intermediate carriage (II), proceeding over
the outermost wheel (16) and underneath the innermost wheel (17), and further over
the wheel (18) located in the top support structure (9) of the top carriage (III),
wherefrom it continues to the lifting carriage, to which its other end is attached;
the second band-like power transmission element (26), which is arranged to transmit
the thrusting motion of the lifting jack piston (20
m), is at one end attached to the top support structure (7) of the mast (I), passes
over the at least one wheel (22, 23) attached to the top support structure (7) of
the intermediate carriage (II), wherefrom it continues to the bottom support structure
(8) of the top carriage (III), whereto it is attached; and
a third band-like power transmission element (25), which also is arranged to transmit
the thrusting motion of the lifting jack piston (20
m), is at one end attached to the top support structure (5) of the mast (I), passes
around the wheel (21) attached to the top support structure (7) of the intermediate
carriage (II) and proceeds to the bottom support structure (8) of the top carriage
(III), where it is attached, at a spot that is located at the same distance from the
symmetry axis (A-A) of the mast truck as the fastening spot of the other band-like
power transmission element (26), but on the opposite side of said symmetry axis (A-A);
in which case the alignments of the band-like power transmission elements are chosen
in order to achieve a balance between the opposite torques created thereby during
the operational steps of the mast truck,
characterized in that
the free-lifting jack (14) and the lifting jack (20) are both located substantially
on the same level of the mast truck that is transversal to the motional direction
of the mast truck, one on one side and one on the other side of the mast truck;
that the axis of the wheel (13) located at the end of the free-lifting jack (14) is
transversal to the proceeding direction of the truck;
that in the first band-like power transmission element (29), there is arranged a band
turning element (15) in order to turn the power transmission element by 90° around
its lengthwise axis along the distance between said wheel (13) located at the end
of the free-lifting jack (14) and said outermost wheel (16) attached to the top support
structure (7) of the intermediate carriage (II); and that the lifting jack piston
(20
m) is arranged to move upwards.
2. A mast truck according to claim 1, characterized in that the band-like power transmission elements (29, 26, 25) for transmitting the thrusting
motion of the jack pistons (14m, 20m) are chains.
3. A mast truck according to claim 1 or 2, characterized in that the hydraulic cylinders (14, 20) are coupled in series by means of a pipe (24).
4. A mast truck according to any of the claims 1 - 3, characterized in that the wheels (16, 17, 22, 23, 21), surrounded by the band-like power transmission elements
(29, 26, 25), said wheels being placed in the top support structure (7) of the intermediate
carriage (II) are located, with respect to the proceeding direction of the truck,
at right angles to the symmetry axis (A-A) of the mast structure, so that the power
torques created during the operational step of the truck are mainly balanced.
5. A mast truck according to claim 4, characterized in that the diameter of the wheel (32) surrounded by the second band-like power transmission
element (26), said wheel being placed in the top support structure (7) of the intermediate
carriage (II), is so large that the clockwise power torque created by the power transmission
element during the operational step of the mast truck is capable of balancing the
counterclockwise torques of the first and third power transmission elements (29, 25).
6. A mast truck according to claim 5, characterized in that the wheel surrounded by the second band-like power transmission element (26), said
wheel being located in the top support structure (5) of the intermediate carriage
(II), is replaced by two adjacent wheels (22, 23) having smaller diameters, while
the element (26) passes over both wheels (22, 23).
7. A mast truck according to any of the preceding claims, characterized in that the tube (27) or tubes required by auxiliary devices are arranged to proceed along
the same route as the power transmission band (29) of the free-lifting jack (14),
but so that while the power transmission band (29) passes around the wheels (16, 17)
attached to the top support structure (7) of the intermediate carriage (II), over
the outer wheel (16) and underneath the inner wheel (17), the tube (27) only passes
over the outer wheel (16) and proceeds to a tube wheel (28) attached to the top support
structure (7) of the intermediate carriage (II), passing underneath said wheel and
further over the wheel attached to the top support structure of the top carriage (III),
while the tube wheel (28) is located above two wheels (16, 17) surrounded by the power
transmission element (29), transversally to the driving direction, on that side of
the wheel (18) placed in the top structure (9) of the top carriage (III) that falls
on the side of the free-lifting jack (14).
1. Gabelstapler, insbesondere ein für Arbeiten in einem Warenlager gedachter Schiebegerüststapler,
umfassend:
- eine Maststruktur, welche einen festen Mast (I) umfasst und wenigstens zwei Laufgestelle
(II und III), von welchen eines ein Zwischengestell (II) ist und vertikal in Bezug
auf den festen Mast (I) bewegbar ist, und das andere ein oberstes Gestell (III) ist
und entlang dem Zwischengestell (II) vertikal bewegbar ist, und welche Maststruktur
weiter ein Hubgestell (19) umfasst, welches durch das oberste Gestell (III) getragen
ist und entlang dem obersten Gestell vertikal bewegbar ist;
- zwei Hydraulikzylinder (14, 20) um die Gestelle (19, II, III) zu bewegen, von welchen
der erste eine frei hebende Hubvorrichtung ist (14), welche das Hubgestell (19) dazu
veranlasst, zu dem obersten Ende des Zwischengestells (II) bewegt zu werden, und der
zweite eine Hubvorrichtung (20) ist, welche das Zwischengestell (II) und das obere
Gestell (III) dazu veranlasst, zu ihren obersten Positionen bewegt zu werden, wobei
die frei hebende Hubvorrichtung (14) eingerichtet ist, um als erste zu wirken, und
die Hubvorrichtung (20) eingerichtet ist, um danach zu wirken; und
- bandähnliche Kraftübertragungselemente (29, 25, 26), welche über Übertragungsräder
(13, 16, 17, 18, 21, 22, 23) laufen und die Schubbewegungen der Zylinderkolben (14m,
20m) zu den Gestellen (II, III, 19) übertragen;
so dass das erste bandähnliche Kraftübertragungselement (29), welches eingerichtet
ist, um die Schubbewegung des Kolbens (14m) der frei hebenden Hubvorrichtung (14)
zu übertragen, an einem Ende an der obersten Tragstruktur (5) des fixen Mastes (I)
befestigt ist, um das an dem freien Ende des Kolbens (14m) der frei hebenden Hubvorrichtung
(14) angeordnete Rad (13) herum läuft und weiter um die an der obersten Tragstruktur
(7) des Zwischengestells (II) befestigten Räder (16, 17) herum läuft, weiter über
das äußerste Rad (16) und unter dem innersten Rad (17) geführt ist, und weiter über
das in der obersten Tragstruktur (9) des obersten Gestells (III) angeordnete Rad (18)
läuft, wovon es zu dem Hubgestell läuft, an welchem sein anderes Ende befestigt ist;
und
das zweite bandähnliche Kraftübertragungselement (26), welches eingerichtet ist, um
die Schubbewegung des Kolbens (20m) der Hubvorrichtung zu übertragen, ist an einem
Ende an der obersten Tragstruktur (7) des Mastes (I) befestigt, läuft über das wenigstens
eine Rad (22, 23), welches an der obersten Struktur (7) des Zwischengestells (II)
befestigt ist, von wo es weiter zu der unteren Tragstruktur (8) des obersten Gestells
(III) läuft, woran es befestigt ist; und
ein drittes bandähnliches Kraftübertragungselement (25), welches ebenfalls eingerichtet
ist, um die Schubbewegung des Kolbens (20m) der Hebevorrichtung zu übertragen, ist
an einem Ende an der obersten Tragstruktur (5) des Mastes (I) befestigt, läuft um
das an der obersten Struktur (7) des Zwischengestells (II) befestigte Rad (21) und
weiter zu der unteren Tragstruktur (8) des obersten Gestells (III), wo es an einem
Punkt befestigt ist, der im selben Abstand von der Symmetrieachse (A-A) des Gabelstaplers
angeordnet ist, wie der Befestigungspunkt des anderen bandähnlichen Kraftübertragungselements
(26), jedoch an der entgegengesetzten Seite dieser Symmetrieachse (A-A);
in welchem Fall die Ausrichtungen der bandähnlichen Kraftübertragungselemente gewählt
sind, um ein Gleichgewicht zwischen den entgegengesetzten Momenten zu erreichen, welche
durch sie während der Betriebsschritte des Gabelstaplers erzeugt werden,
dadurch gekennzeichnet, dass die frei hebende Hubvorrichtung (14) und die Hubvorrichtung (20) beide im Wesentlichen
auf derselben Höhe, welche quer zu der Bewegungsrichtung des Gabelstaplers ist, des
Gabelstaplers angeordnet sind, eine an einer Seite und eine an der anderen Seite des
Gabelstaplers;
dass die Achse des an dem Ende der frei hebenden Hubvorrichtung (14) angeordneten
Rads (13) quer zu der Fortbewegungsrichtung des Gabelstaplers ist;
dass in dem ersten bandähnlichen Kraftübertragungselement (29) ein Banddrehelement
(15) eingerichtet ist, um das Kraftübertragungselement entlang der Distanz zwischen
diesem Rad (13), welches an dem Ende der frei hebenden Hubvorrichtung (14) angeordnet
ist, und dem äußersten Rad (16), welches an der obersten Tragstruktur (7) des Zwischengestells
(II) befestigt ist, um 90° um seine Längsachse zu drehen; und
dass der Kolben (20m) der Hubvorrichtung eingerichtet ist, um sich nach oben zu bewegen.
2. Gabelstapler nach Anspruch 1,
dadurch gekennzeichnet, dass die bandähnlichen Kraftübertragungselemente (29, 26, 25) zur Übertragung der Schubbewegung
der Kolben (14m, 20m) der Hubvorrichtungen Ketten sind.
3. Gabelstapler nach Anspruch 1 oder 2,
dadurch gekennzeichnet, dass die Hydraulikzylinder (14, 20) mittels einer Leitung (24) in Serie gekoppelt sind.
4. Gabelstapler nach einem der Ansprüche 1 bis 3,
dadurch gekennzeichnet, dass die Räder (16, 17, 22, 23, 21), welche von den bandähnlichen Kraftübertragungselementen
(29, 26, 25) umgeben sind, und welche Räder in der obersten Tragstruktur (7) des Zwischengestells
(II) platziert sind, bezüglich der Fortbewegungsrichtung des Gabelstaplers in rechten
Winkeln zu der Symmetrieachse (A-A) der Maststruktur angeordnet sind, so dass die
während der Betriebsschritte des Gabelstaplers erzeugten Kraftmomente größtenteils
ausbalanciert werden.
5. Gabelstapler nach Anspruch 4,
dadurch gekennzeichnet, dass der Durchmesser des von dem zweiten bandähnlichen Kraftübertragungselement (26) umgebenen
Rads (32), welches Rad in der obersten Tragstruktur (7) des Zwischengestells (II)
platziert ist, so groß ist, dass das Kraftmoment im Uhrzeigersinn, welches durch das
Kraftübertragungselement während des Betriebsschritts des Gabelstaplers erzeugt wird,
in der Lage ist, die Momente gegen den Uhrzeigersinn der ersten und dritten Kraftübertragungselemente
(29, 25) auszubalancieren.
6. Gabelstapler nach Anspruch 5
dadurch gekennzeichnet, dass das von dem zweiten bandähnlichen Kraftübertragungselement (26) umgebene Rad, welches
Rad in der obersten Tragstruktur (5) des Zwischengestells (II) angeordnet ist, durch
zwei benachbarte Räder (22, 23) ersetzt ist, welche kleinere Durchmesser haben, während
das Element (26) über beide Räder (22, 23) läuft.
7. Gabelstapler nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet, dass die Leitung (27) oder von Zusatzgeräten benötigte Leitungen angeordnet sind, um entlang
desselben Wegs zu laufen, wie das Kraftübertragungsband (29) der frei hebenden Hubvorrichtung
(14), aber so, dass während das Kraftübertragungsband (29) um die an der obersten
Tragstruktur (7) des Zwischengestells (II) befestigten Räder (16, 17) läuft, über
das äußere Rad (16) und unter das innere Rad (17), die Leitung (27) nur über das äußere
Rad (16) und weiter zu einem Leitungsrad (28) läuft, welches an der obersten Tragstruktur
(7) des Zwischengestells (II) befestigt ist, unter diesem Rad her läuft und von da
weiter über das Rad, welches an der obersten Tragstruktur des obersten Gestells (III)
befestigt ist, während das Leitungsrad (28) über zwei Rädern (16, 17), welche von
dem Kraftübertragungselement (29) umgeben sind, und quer zur Fahrtrichtung angeordnet
ist, an der Seite des Rads (18), welches in der obersten Struktur (9) des obersten
Gestells (III) platziert ist, welche auf die Seite der frei hebenden Hubvorrichtung
(14) fällt.
1. Camion à mât, particulièrement un camion de portée conçu pour des opérations d'entreposage,
comprenant
une structure de mât comprenant un mât fixe (I) et au moins deux chariots mobiles
(II et III), dont l'un est un chariot intermédiaire (II) et mobile verticalement par
rapport au mât fixe (I), et l'autre est un chariot supérieur (III) et mobile verticalement
le long du chariot intermédiaire (II) et comprenant en outre un chariot de levage
(19), qui est supporté par le chariot supérieur (III) et mobile verticalement le long
du chariot supérieur ;
deux vérins hydrauliques (14, 20) destinés à déplacer les chariots (19, II, III),
dont le premier est un vérin de levage libre (14), forçant le chariot de levage (19)
à être décalé vers l'extrémité supérieure du chariot intermédiaire (II) et dont le
deuxième est un vérin de levage (20), forçant le chariot intermédiaire (II) et le
chariot supérieur (III) à être décalés vers leurs positions supérieures, alors que
le vérin de levage libre (14) est disposé pour fonctionner le premier, et le vérin
de levage (20) est disposé pour fonctionner par la suite ;
et des éléments de transmission de puissance en forme de bande (29, 25, 26) passant
à travers des roues de transmission (13, 16, 17, 18, 21, 22, 23) et qui transmettent
les mouvements de poussée des pistons des vérins (14m, 20m) aux chariots (II, III, 19) ;
afin que le premier élément de transmission de puissance en forme de bande (29), qui
est disposé pour transmettre le mouvement de poussée du piston (14m) du vérin de levage libre, soit fixé au niveau d'une extrémité à la structure de
support supérieure (5) du mât fixe (I), passe autour de la roue (13) située au niveau
de l'extrémité libre du piston (14m) du vérin de levage libre (14) et passe en outre autour des roues (16, 17), fixées
à la structure de support supérieure (7) du chariot intermédiaire (II), avançant sur
la roue la plus à l'extérieur (16) et en dessous de la roue la plus à l'intérieur
(17) et en outre sur la roue (18) située dans la structure de support supérieure (9)
du chariot supérieur (III), d'où il continue vers le chariot de levage, auquel son
autre extrémité est fixée ;
le deuxième élément de transmission de puissance en forme de bande (26), qui est agencé
pour transmettre le mouvement de poussée du piston du vérin de levage (20m) est fixé au niveau d'une extrémité à la structure de support supérieure (7) du mât
(I), passe sur au moins une roue (22, 23) fixée à la structure de support supérieure
(7) du chariot intermédiaire (II), d'où il continue vers la structure de support inférieure
(8) du chariot supérieur (III), à laquelle il est fixé ; et
un troisième élément de transmission de puissance en forme de bande (25), qui est
également agencé pour transmettre le mouvement de poussée du piston du vérin de levage
(20m), est fixé au niveau d'une extrémité à la structure de support supérieure (5) du
mât (I), passe autour de la roue (21) fixée à la structure de support supérieure (7)
du chariot intermédiaire (II) et avance vers la structure de support inférieure (8)
du chariot supérieur (III), où il est fixé, au niveau d'un point qui est situé à la
même distance de l'axe de symétrie (A - A) du camion à mât que le point de fixation
de l'autre élément de transmission de puissance en forme de bande (26), mais du côté
opposé dudit axe de symétrie (A - A) ;
auquel cas les alignements des éléments de transmission de puissance en forme de bande
sont choisis afin d'atteindre un équilibre entre les couples opposés créés ainsi pendant
les étapes opérationnelles du camion à mât, caractérisé en ce que
le vérin de levage libre (14) et le vérin de levage (20) sont tous les deux situés
sensiblement sur le même niveau du camion à mât qui est transversal à la direction
de mouvement du camion à mât, un d'un côté et l'autre de l'autre côté du camion à
mât ;
en ce que l'axe de la roue (13) située au niveau de l'extrémité du vérin de levage libre (14)
est transversal à la direction d'avancée du camion ; en ce que dans le premier élément de transmission de puissance en forme de bande (29), est
disposé un élément de tournage de bande (15) afin de tourner l'élément de transmission
de puissance de 90° autour de son axe dans le sens de la longueur le long d'une distance
entre ladite roue (13) située au niveau de l'extrémité du vérin de levage libre (14),
et ladite roue la plus à l'extérieur (16) fixée à la structure de support supérieure
(7) du chariot intermédiaire (II) ;
et en ce que le piston du vérin de levage (20m) est disposé pour se déplacer vers le haut.
2. Camion à mât selon la revendication 1, caractérisé en ce que les éléments de transmission de puissance en forme de bande (29, 26, 25) destinés
à transmettre le mouvement de poussée des pistons de levage (14m, 20m) sont des chaînes.
3. Camion à mât selon la revendication 1 ou 2, caractérisé en ce que les vérins hydrauliques (14, 20) sont couplés en série au moyen d'un tuyau (24).
4. Camion à mât selon l'une quelconque des revendications 1 à 3, caractérisé en ce que les roues (16, 17, 22, 23, 21) entourées par les éléments de transmission de puissance
en forme de bande (29, 26, 25), lesdites roues étant placées dans la structure de
support supérieure (7) du chariot intermédiaire (II), sont situées par rapport à la
direction d'avancée du camion, à angles droits par rapport à l'axe de symétrie (A-A)
de la structure de mât, afin que les couples de puissance créés pendant l'étape opérationnelle
du camion soient principalement équilibrés.
5. Camion à mât selon la revendication 4, caractérisé en ce que le diamètre de la roue (32) entourée par le deuxième élément de transmission de puissance
en forme de bande (26), ladite roue étant placée dans la structure de support supérieure
(7) du chariot intermédiaire (II), est tellement grand que le couple de puissance
dans le sens des aiguilles d'une montre créé par l'élément de transmission de puissance
pendant l'étape opérationnelle du camion à mât est capable d'équilibrer les couples
dans le sens inverse des aiguilles d'une montre des premier et troisième éléments
de transmission de puissance (29, 25).
6. Camion à mât selon la revendication 5, caractérisé en ce que la roue entourée par le deuxième élément de transmission de puissance en forme de
bande (26), ladite roue étant située dans la structure de support supérieure (5) du
chariot intermédiaire (II), est remplacée par deux roues adjacentes (22, 23) présentant
des diamètres plus petits, alors que l'élément (26) passe sur les deux roues (22,
23).
7. Camion à mât selon l'une quelconque des revendications précédentes, caractérisé en ce que le tube (27) ou des tubes requis par des dispositifs auxiliaires sont disposés pour
avancer le long de la même route que la bande de transmission de puissance (29) du
vérin de levage libre (14), mais afin que pendant que la bande de transmission de
puissance (29) passe autour des roues (16, 17) fixées à la structure de support supérieure
(7) du chariot intermédiaire (II), sur la roue extérieure (16) et en dessous de la
roue intérieure (17), le tube (27) passe uniquement sur la roue extérieure (16) et
avance vers une roue à tube (28) fixée à la structure de support supérieure (7) du
chariot intermédiaire (II), passant en dessous de ladite roue et en outre sur la roue
fixée à la structure de support supérieure du chariot supérieur (III), alors que la
roue à tube (28) est située au-dessus des deux roues (16, 17) entourées par l'élément
de transmission de puissance (29), transversalement à la direction d'entraînement,
sur ce côté de la roue (18) placée dans la structure supérieure (9) du chariot supérieur
(III) qui tombe du côté du vérin de levage libre (14).