EP3819255B1 - Industrial truck, in particular reach truck - Google Patents

Description

The invention relates to an industrial truck, in particular a reach truck, with two wheels arranged at a distance from one another in the transverse direction of the vehicle and a third wheel arranged at a distance from the two wheels in the longitudinal direction of the vehicle, the industrial truck having at least one support element arranged laterally next to the third wheel and adjustable in height in the vertical direction of an actuator between a raised position and a lowered support position on a vehicle frame of the industrial truck can be adjusted in the vertical direction, wherein in the lowered support position the industrial truck can be supported with the support element on a roadway, the actuator being connected to the support element by means of a coupling rod mechanism Actuation is operatively connected.

In industrial trucks of this type with a three-wheel chassis, it is known to provide a support element, a so-called bump stop, next to the third wheel on the outside of the vehicle, in order to improve lateral stability and thus the residual capacity, particularly when stacking and unstacking loads of the industrial truck. The residual capacity of the industrial truck is determined, among other things, by the vertical distance of the support element from the roadway and thus from the ground.

However, there is a conflict of objectives here: on the one hand, the smallest possible vertical distance between the support element and the roadway is desired in order to achieve a high residual capacity of the industrial truck, but on the other hand, the distance between the support element and the roadway should be as large as possible in order to to enable one to drive over thresholds and bumps in the ground and on the other hand to compensate for the tire wear of the third wheel, which is usually designed as a steered and driven drive wheel. For this it is known, depending on the height of a lifting mast of the industrial truck, the size of the vehicle frame, the vehicle weight of the industrial truck and the maximum load weight of a recorded load using spacer plates a specific vertical distance between the support elements fixed to the vehicle frame and the roadway.

From the DE 43 03 007 C1 a generic industrial truck is known which has at least one vertically adjustable support element on the side next to the third wheel, which can be adjusted in the vertical direction by means of an actuator between a raised position and a lowered support position on a vehicle frame of the industrial truck, wherein in the lowered support position the industrial truck can be supported on the roadway with the support element in order to increase the residual capacity of the industrial truck. This document discloses the features of the preamble of claim 1. In an industrial truck with height-adjustable support elements according to DE 43 03 007 C1 is disadvantageous in that the support elements have a fixed stroke and the tire wear on the third wheel, which is designed as a drive wheel, and uneven ground are not compensated. If the tires on the third wheel are correspondingly worn, it can happen that the support elements hit the ground when lowered and the further extension of the support elements lifts the industrial truck with the third wheel off the road so that the industrial truck can no longer be moved. The same applies if there are corresponding unevennesses in the floor. If there is a corresponding elevation below a support element, it can happen that the corresponding support element touches down on the corresponding elevation when extending downwards and the truck with the third wheel lifts off the roadway as the support elements continue to extend, so that the truck no longer moves can be.

The EP 2 805 911 A1 discloses an industrial truck designed as an order-picking industrial truck with two wheels arranged at a distance from one another in the vehicle transverse direction and a third wheel arranged at a distance from the two wheels in the longitudinal direction of the vehicle, the industrial truck having at least one support element arranged to be height-adjustable in the vertical direction on the side next to the third wheel, which by means of a hydraulic cylinder trained actuator between a raised position and a lowered support position on a vehicle frame of the truck in the vertical direction is adjustable, wherein in the lowered support position a support of the industrial truck with the support element on a roadway can be achieved.

From the EP 2 067 738 A1 discloses an industrial truck with two wheels spaced apart from one another in the vehicle transverse direction and a third wheel spaced apart from the two wheels in the vehicle longitudinal direction, the industrial truck having a support element on the side next to the third wheel. The support element is formed by a hexagonal prism whose outer lateral surfaces are at different distances from a bore axis of a fastening bore of the prism, with which the prism is fastened to the industrial truck. By turning the prism into different installation positions, the ground clearance on the prism can be adjusted and changed.

The object of the present invention is to provide an industrial truck of the type mentioned at the outset that is improved with regard to the disadvantages mentioned.

This object is achieved according to the invention in that the coupling rod mechanism is supported on a support element which can be adjusted in the vertical direction and which, when the support element is lowered onto the roadway, enables further actuation of the actuator and the coupling rod mechanism which does not lead to a further extension and a further extension movement of the support element . This ensures that the actuator via the coupling rod mechanism on the one hand
Support element shifts and on the other hand shifts the support element. This makes it possible that after the support element has been placed on the roadway, further actuation of the actuator does not lead to a further extension and a further extension movement of the support element, but further actuation of the actuator leads to a displacement of the support element. As a result, the tire wear on the third wheel and/or uneven ground can be faded out in a simple manner and the lifting of the industrial truck with the third wheel off the roadway can be prevented.

According to a preferred embodiment of the invention, the third wheel is arranged centrally in the transverse direction of the vehicle and two supporting elements are provided on the side of the third wheel. With two support elements next to the drive wheel on both sides of the vehicle, the residual capacity of the industrial truck can be improved in a safe manner by extending the support elements into the support position.

According to an advantageous embodiment of the invention, the connecting rod mechanism has a first connecting rod which is connected at a first end to the support element and at a second end is connected to the actuator, and a second connecting rod which is connected at a first end to the support element is connected and at a second end communicates with the actuator. This makes it possible in a simple manner for the actuator to be able to actuate and displace both the support element and the support element, so that the adjustment path of the actuator can be variably divided between a displacement path of the support element and a displacement path of the support element, so that after the support element has been placed on of the roadway upon further actuation of the actuator to prevent further extension and a further extension movement of the support element and to convert the further actuation of the actuator into a corresponding displacement path of the support element.

The actuator is advantageously connected to the first coupling rod and the second coupling rod by means of a third coupling rod. The third coupling rod allows in a simple way a compensating movement between the actuator and the first and the second coupling rod in order to adjust the displacement of the Divide actuator variable on a displacement path of the support element and a displacement path of the support element.

Advantageously, the actuating drive is designed as a linear drive with an actuating rod that can be extended and retracted. The supporting element and the supporting element can be actuated in a simple manner with a linear drive via the coupling rod mechanism.

The support element can be arranged on the industrial truck so that it can be adjusted in the vertical direction by means of a linear guide.

According to an advantageous embodiment of the invention, the support element is arranged to be adjustable in the vertical direction by means of at least one rocker on the industrial truck. With a swing arm, the support element can easily be arranged on the industrial truck so that it can be adjusted in the vertical direction.

If, according to an advantageous embodiment of the invention, the support element is arranged on the industrial truck so that it can be adjusted in the vertical direction by means of two rockers, which are designed as a parallelogram suspension, an adjustment of the support element in the vertical direction can be achieved with little construction effort with the two rockers, which in the Support position of the support element can transmit and absorb high forces.

The support element is preferably urged into the raised position by means of a spring device. With a spring device, the support element can be loaded into the raised position in a safe and simple manner, in order to achieve high ground clearance for the industrial truck.

The spring device is expediently designed as a tension spring which acts on the rocker and on the vehicle frame.

According to an advantageous embodiment of the invention, the support element is designed as a sliding piece arranged to be longitudinally displaceable in a vertical slot.

This results in a simple construction of the vertically adjustable support member.

The support element is advantageously acted upon by a spring device supported on the vehicle frame, in particular a compression spring. With a spring device acting on the support element, it is possible that when the actuator is actuated, initially only the support element extends downwards and only then, when the support element has been lowered onto the roadway, further actuation of the actuator to move the support element against the force of the Spring device leads. Safe operation of the support element and safe lowering of the support element onto the roadway can thus be achieved with the spring device.

Advantageously, the prestressing of the spring device can be adjusted by means of an adjusting element, in particular an adjusting screw.

According to a development of the invention, a locking device is provided that locks the support element in the lowered support position and can be actuated between a release position and a locking position, the locking device being operable from the release position to the locking position upon further actuation of the actuator by the coupling rod mechanism. With a locking device, the support element actuated in the support position can be locked in a simple and safe manner in order to be able to absorb high forces from the support element in the support position of the support element and to be able to introduce them into the vehicle frame. If the locking device is actuated by the coupling rod mechanism from the release position to the locking position during further actuation of the actuating drive, after the support element has been lowered onto the roadway, the further actuation and movement of the actuating drive and the coupling rod mechanism can be used to move the locking device into the locking position actuate. This enables the locking device to be actuated easily and safely using the actuator that is already present.

According to an advantageous embodiment of the invention, the locking device has a toothed element arranged on the support element first toothed element and a second toothed element which is arranged on an actuating lever and is provided with a toothing, which second toothed element can be brought into engagement with the first toothed element in the locking position. With a toothed element arranged on the support element and a toothed element arranged on the actuating lever, a locking device can be formed in a simple manner, which enables positive locking in the locking position by the toothed elements being in engagement.

According to a preferred embodiment of the invention, the actuating lever is pivotably arranged and can be actuated by the coupling rod mechanism. This enables the locking device to be easily actuated into the locking position by the actuator and the connecting rod mechanism.

According to an advantageous development of the invention, the actuating lever is acted upon in the direction of the release position by a spring device supported on the vehicle frame, in particular a compression spring. The locking device can be easily actuated into the release position by a spring device acting on the actuating lever.

According to an advantageous development of the invention, in addition to the height-adjustably arranged support element, a support element arranged fixedly on the vehicle frame is provided. This increases the operational safety of the industrial truck in a simple manner, since if there is a fault or defect in the height-adjustably arranged support element, the fixed support element is effective in order to increase the residual capacity of the industrial truck.

With regard to a small installation space requirement, there are advantages if, according to an advantageous embodiment of the invention, the height-adjustably arranged support element is arranged inside the fixedly arranged support element.

According to an advantageous development of the invention, the actuator is controlled by an electronic control device, with the electronic control device being designed in such a way that the support element is controlled as a function of the lifting height of a load handling device of the industrial truck and/or as a function of the travel speed of the industrial truck. This allows on simply the "material transport" operating state, in which a picked-up load is lowered and the industrial truck travels at high driving speed from a first location to a second location, for example in a storage area, and the "storage/retrieval" operating state of a load are determined, in which the load handler is raised and the truck only moves slowly. If the electronic control device automatically moves the height-adjustable support element to the raised position in the “material transport” operating state, high ground clearance can be achieved in order to enable thresholds and uneven floors to be driven over. If the electronic control device automatically moves the height-adjustable support element to the lowered support position in the "Storage/Retrieval" operating state, the ground clearance can be reduced in order to increase the residual capacity of the industrial truck when storing or retrieving a load.

The industrial truck according to the invention has a number of advantages. With the height-adjustable support elements, the vertical distance between the support elements and the roadway can be automatically reduced in the "storage/retrieval" operating state with the support elements in the support position, in order to increase the residual capacity of the industrial truck. In the "material transport" operating mode, a high ground clearance can be achieved with the support elements raised, in order to enable thresholds and uneven floors to be driven over. When lowering the support elements into the support position, the tire wear of the third wheel and/or unevenness in the ground are taken into account and compensated for in the industrial truck according to the invention, and it is prevented that when the support elements are extended after the support elements have been placed on the roadway, further actuation of the actuator results in lifting of the third wheel leads off the road.

Figur 1

ein erfindungsgemäßes Flurförderzeug in einer schematischen Seitenansicht,

Figur 2

das Flurförderzeug der Figur 1 in einer schematischen Draufsicht,

Figur 3

ein Abstützelement des erfindungsgemäßen Flurförderzeugs in einer Seitenansicht,

Figur 4

einen Ausschnitt der Figur 3 in einer Schnittdarstellung,

Figur 5

einen Ausschnitt der Figur 4 in einer vergrößerten Darstellung,

Figur 6

einen Ausschnitt der Figur 4 in einer vergrößerten Darstellung,

Figur 7

einen Ausschnitt der Figur 4 in einer vergrößerten Darstellung,

Figur 8

einen Ausschnitt der Figur 3 in einer vergrößerten Darstellung,

Figur 9

eine Schnittdarstellung gemäß der Figur 4 in der angehobenen Stellung des Abstützelements und

Figur 10

die Figur 9 in der abgesenkten Abstützstellung des Abstützelements.

Further advantages and details of the invention are explained in more detail with reference to the exemplary embodiment illustrated in the schematic figures. Here shows

figure 1

an industrial truck according to the invention in a schematic side view,

figure 2

the industrial truck figure 1 in a schematic plan view,

figure 3

a support element of the industrial truck according to the invention in a side view,

figure 4

a section of figure 3 in a sectional view,

figure 5

a section of figure 4 in an enlarged view,

figure 6

a section of figure 4 in an enlarged view,

figure 7

a section of figure 4 in an enlarged view,

figure 8

a section of figure 3 in an enlarged view,

figure 9

a sectional view according to figure 4 in the raised position of the supporting element and

figure 10

the figure 9 in the lowered support position of the support element.

In the Figures 1 and 2 an industrial truck 1 according to the invention is shown. The industrial truck 1 is designed as a reach truck 2 in the illustrated embodiment.

The industrial truck 1 has a three-wheel chassis and is supported on a roadway FB by means of two wheels 3, which are arranged on wheel arms 4 of a vehicle frame 5, and a third wheel 6, which is arranged on the vehicle frame 5. In the exemplary embodiment shown, the wheels 3 are designed as non-steered and non-driven load wheels. In the exemplary embodiment shown, the third wheel 6 is designed as a steerable drive wheel driven by means of a traction drive, for example an electric traction motor, which is not shown in detail. The two wheels 3 are arranged at a distance from one another in the transverse direction Q of the vehicle. The third wheel 6 is spaced apart from the two wheels 3 in the longitudinal direction L of the vehicle. For example as a drive wheel trained third wheel 6 is seen in the vehicle transverse direction Q arranged centrally. The two wheels 3 are each from the centrally located third wheel 6 - as in connection with the figure 2 can be seen - spaced in the vehicle transverse direction Q and are located on the corresponding vehicle outsides.

A driver's canopy 7 with a driver's workplace is arranged vertically above the third wheel 6 on the vehicle frame 5 .

Between the two wheel arms 4, a mast 8 is arranged to be displaceable in the longitudinal direction L of the vehicle by means of a thrust drive, which is not shown in detail. A load handling device 9 is arranged on the mast 8 so that it can be raised and lowered by means of a lifting drive, which is not shown in detail. In the exemplary embodiment shown, the load handling device 9 is designed as a load fork with two forks.

The industrial truck according to the invention is provided with two vertically adjustable supporting elements 10 which are arranged laterally next to the third wheel 6 in the area of the outside of the vehicle. The support elements 10 are thus spaced apart from the two wheels 3 in the longitudinal direction L of the vehicle and are arranged at the level of the third wheel 6 . In the transverse direction Q of the vehicle, the supporting elements 10 are arranged at a lateral distance from the third wheel 6 .

In addition, a support element 11 fixedly arranged on the vehicle frame 5 can be arranged in the region of each support element 10 arranged to be adjustable in height in the vertical direction.

In the Figures 3 to 8 the support element 10 arranged on one side of the vehicle is shown, on which the structure of the two height-adjustable support elements 10 is described in more detail. On the opposite side of the vehicle, a support element 10 constructed analogously to the support element 10 shown is arranged.

The height-adjustable arranged supporting element 10 is - as in the figure 3 can be seen - is - by means of an actuator 15 between a raised position and a lowered support position on the vehicle frame 5 of the truck 1 in the vertical direction V adjustable. The figure 3 shows the height-adjustably arranged supporting element 10 in the raised position. In the lowered support position of the support element 10 arranged in a height-adjustable manner, the industrial truck 1 can be supported on the roadway FB with the support element 10 extended downwards.

The actuating drive 15 is operatively connected to the adjustable support element 10 by means of a coupling rod mechanism 20 in order to actuate it. The coupling rod mechanism 20 is also supported on a support element 21, which can be adjusted in the vertical direction V and which, when the supporting element 10 is lowered onto the roadway, enables further actuation of the actuating drive 15 and the coupling rod mechanism 20, which does not lead to a further extension and a further extension movement of the supporting element.

The support element 10 is arranged to be adjustable in the vertical direction V on a holder 22 arranged on the vehicle frame 5 . The holder 22 has two spaced-apart holding plates 22a, 22b, of which in FIG figure 3 only the retaining plate 22a lying at the front in the side view is shown.

The actuating drive 15 is supported on the vehicle frame 5 by means of a further holder 23 .

In the figure 3 the support element 10 fixedly arranged on the vehicle frame 5 is also shown.

In the figure 4 is a section of figure 3 shown in a sectional view, wherein the holding plate 22b of the holder 22 is shown.

The coupling rod mechanism 20 has - as from the figure 4 and the figure 5 can be seen in which an enlarged section of the figure 4 shown - a first coupling rod 30, which is connected at a first end to the height-adjustable support element 10 and at a second end to the actuator 15, and a second coupling rod 31, which is connected at a first end to the support element 21 is connected and is connected to the actuator 15 at a second end.

Furthermore, the actuating drive 15 is connected to the first coupling rod 30 and the second coupling rod 31 by means of a third coupling rod 32 . The third coupling rod 32 thus connects the actuator 15 to the height-adjustable support element 10 via the first coupling rod 30 and to the support element 21 via the second coupling rod 31.

In the exemplary embodiment shown, the actuating drive 15 is designed as a linear drive, for example an electric linear drive, with an actuating rod 34 that can be extended and retracted. The actuator 15 is controlled by an electronic control device 35 .

The first coupling rod 30 is articulated to the height-adjustable support element 10 at an articulation axis G1 and articulated to the third coupling rod 32 at an articulation axis G2. The second coupling rod 31 is articulated at an articulation axis G3 on the support element 21 arranged to be adjustable in the vertical direction V and articulated at the articulation axis G2 on the third coupling rod 32 . The third coupling rod 32 is attached in an articulated manner to the actuating rod 34 of the actuator 15 at a joint axis G4.

The coupling rods 30, 31 are arranged between the two holding plates 22, 22b of the holder 22.

The height-adjustable support element 10 is - as from the figure 4 and the figure 6 can be seen in which an enlarged section of the figure 4 is shown - by means of at least one rocker 40, 41 on the arranged on the vehicle frame 5 of the truck 1 holder 22 in the vertical direction V adjustable.

In the exemplary embodiment shown, the height-adjustable support element 10 is arranged on the holder 22 so that it can be adjusted in the vertical direction V by means of two rockers 40, 41, which are designed as a parallelogram suspension. The two rockers 40, 41 are arranged spaced apart from one another in the vertical direction V, the rocker 40 forming a lower rocker and the rocker 41 forming an upper rocker.

The rocker 40 is rotatably arranged on the holder 22 on an axis of rotation D1 and on the height-adjustable support element 10 on an axis of rotation D2 arranged. The rocker 41 is rotatably arranged on the holder 22 on a rotation axis D3 and on the height-adjustable support element 10 on a rotation axis D4. In the exemplary embodiment shown, the axis of rotation D4 is arranged coaxially with the joint axis G1. The axes of rotation D1 to D4 of the two rockers 40, 41 form a parallelogram, so that with the two rockers 40, 41 a parallelogram suspension and a parallelogram guidance of the height-adjustable support element 10 is achieved.

The height-adjustable support element 10 is acted upon by a spring device 45 in the raised position. In the exemplary embodiment shown, the spring device 45 is designed as a tension spring 46 which engages with a first end on the upper rocker 41 and with a second end on the vehicle frame 5 or on the vehicle frame 5 arranged holder 22 acts. For this purpose, the upper rocker 41 is designed as a two-armed lever, which has a first lever arm 41a, on which the axis of rotation D4 is arranged, and a second lever arm 41b, on which the spring device 45 acts.

The rockers 40, 41 and the spring device 45 are arranged between the two holding plates 22a, 22b of the holder 22.

The adjustable in the vertical direction V arranged support member 21 is - as from the figure 4 and the figure 7 can be seen in which an enlarged section of the figure 4 is shown - as a longitudinally displaceable arranged in a vertical slot 51 slider 50 is formed. The vertically arranged long hole 51 is formed in the holder 22 . In the exemplary embodiment shown, each of the two holding plates 22a, 22b of the holder 22 is provided with a corresponding elongated hole 51, in which a sliding piece 50 is arranged in a longitudinally displaceable manner, so that two sliding pieces 50 are provided as a support element 21, which are connected to the coupling rod 31.

The support element 21 is acted upon by a spring device 55 supported on the holder 22 and thus on the vehicle frame 5 . In the exemplary embodiment shown, the spring device 55 is designed as a compression spring 56 which generates a compressive force acting vertically downwards on the support element 21 . In the exemplary embodiment shown, the spring device 55 can be adjusted in terms of its pretension by means of an adjusting element 57, for example an adjusting screw. The The adjusting element 57 is arranged on a stop plate 58 arranged on the holder 22 and enables the compression spring 56 to be adjusted in the pretension via a spring plate, which is not shown in detail.

How from the figure 3 , the figure 7 and the figure 8 can be seen in which an enlarged section of the figure 4 is shown - there is also a locking device 60 which locks the height-adjustable support element 10 in the lowered support position and can be actuated between a release position and a locking position. After the support element 10 has been placed on the roadway, the locking device 60 can be actuated by the coupling rod mechanism 20 from the release position into the locking position as the actuating drive 15 is actuated further.

The locking device 60 has a first toothed element 61 which is arranged on the support element 21 and has a toothing V1, and a second toothed element 62 which is arranged on an actuating lever 64 and has a toothing V2 and which can be brought into engagement with the first toothed element 61 in the locking position. For this purpose, the first toothed element 61 is fastened to the sliding piece 50 . In the exemplary embodiment shown, a first toothed element 61 is fastened to each of the two sliders 50, so that two first toothed elements 61 are provided. How from the figure 3 and the figure 8 As can be seen, one of the toothed elements 61 is arranged on the outside of the holding plate 22a, which is attached to the sliding piece 50, which can be displaced in the slot 51 of the holding plate 22a, for example by means of fastening screws 59. A further toothed element 61 is arranged correspondingly on the outside of the holding plate 22b , which is fixed to the sliding piece 50, which is slidable in the slot 51 of the holding plate 22b. The actuating lever 64 is correspondingly provided with two second toothed elements 62 which are arranged on the outer sides of the two holding plates 22a, 22b.

The actuating lever 64 is on a pivot axis S1 - as shown in FIG figure 7 can be seen - arranged pivotably on the holder 22. The actuating lever 64 is arranged between the two holding plates 22a, 22b of the holder 22.

The actuating lever 64 can be actuated by the coupling rod mechanism 20 into the locking position of the locking device 60 . The actuating lever 64 is designed for this purpose as a two-armed lever which is connected to a first lever arm 64a with the Tooth elements 62 is connected. This can - as from the figure 7 and 8th as can be seen - a fastening bolt 65 can be fastened to the first lever arm 64a, which extends outwards through corresponding elongated holes 66 in the two holding plates 22a, 22b and is connected to the two toothed elements 62 on the outer sides of the holding plates 22a, 22b. On a second lever arm 64b of the actuating lever 64 there is an actuating surface 68 on which the actuating lever 64 can be actuated by means of the coupling rod mechanism 20 .

The actuating lever 64 is acted upon by a spring device 70 supported on the holder 22 and thus on the vehicle frame 5 in the direction of the release position of the locking device 60 . In the exemplary embodiment shown, the spring device 70 is designed as a compression spring 71 which acts on the lever arm 64b opposite the coupling rod mechanism 20 and is supported on the holder 22 .

How from the figure 4 and the figure 6 As can be seen, the height-adjustable support element 10 is designed as a push rod 10a, on which the rockers 40, 41 are articulated. A support plate 10b is fastened to the underside of the push rod 10a, for example with a fastening screw 90. The support plate 10b can be provided with a distance sensor. One or more spacer discs 91 can also be arranged between the push rod 10a and the support plate 10b.

The holder 22 with the support element 10 that can be adjusted in the vertical direction V on the holder 22 is arranged on the upper side of the vehicle frame 5 . In order to be able to lower the support element 10 down onto the roadway, the vehicle frame 5 is provided with a recess 95 through which the support element 10 extends to the underside of the vehicle frame 5 .

The fixed support element 11 consists - as from the figure 4 and the figure 6 can be seen - from a plate 11a, which is attached to the underside of the vehicle frame 5, for example by means of several fastening screws 96. Furthermore, one or more spacers 98 can be arranged between the vehicle frame 5 and the plate 11a. The height-adjustable support element 10 is arranged within the fixed support element 11 . about that To be able to lower the support element 11 down onto the roadway, the fixed support element 11 is provided with a recess 97 through which the height-adjustable support element 10 extends through the fixed support element 11 .

The function of the invention is based on the below figures 9 and 10 described.

The figure 9 shows the height-adjustable support element 10 in the deactivated state, in which the actuating rod 34 of the actuator 15 is in the retracted state (in FIG figure 9 to the left) and by means of the coupling rod mechanism 20, the vertically adjustable support element 10 is retracted upwards and is in the raised position. The coupling rods 30, 31, 32 are located in the figure 9 shown position in which the coupling rods 30, 31, 32 are arranged like a Y. The coupling rod 31 is positioned by means of the spring device 55 . The coupling rod 30 is positioned by means of the spring device 45 . The adjustable support element 10 is - as from the figure 6 is retracted upwards and is in the raised position within the fixed support element 11. The actuating lever 64 is acted upon by the spring device 70 into the release position of the locking device 60, in which the toothed elements 62 are not in engagement with the toothed elements 61. The adjustable support element 10 is in an operating state "material transport" of the industrial truck 1 in the retracted position at the top figure 9 This operating state is detected by the electronic control device 35 that controls the actuator 15, for example when the load handling device 9 is lowered below a limit lifting height by means of a corresponding sensor and/or the industrial truck 1 is traveling faster than a minimum driving speed. The fixed support element 11 is attached at such a height that the fixed support element 11 can come into contact with the roadway FB when the industrial truck 1 is cornering with the load handling device 9 lowered in order to prevent the industrial truck 1 from tipping over.

Goes the truck 1 from the operating state "material transport" in the operating state "storage / retrieval", for example by the electronic control device 35 lifting the load handling device 9 above the Limit lifting height is detected and / or the truck 1 is moving slower than the minimum driving speed, the control device 35 automatically controls the actuator 15 in such a way that the actuating rod 34 moves in the figure 9 exits on the right. The spring forces of the spring devices 45 and 55 and the lever ratios of the coupling rods 30, 31, 32 and the rocker 41 are designed in such a way that when the actuating rod 34 of the actuator 15 is extended, initially only the adjustable support element 10 is extended downwards by means of the coupling rod 30 However, the support element 21 is held in its position by the spring device 55 . In this first operating range of the actuator 15, the adjustable support element 10 is thus adjusted downwards until the support element 10 is lowered onto the roadway FB and touches down on the roadway FB. In the first operating range, however, the support element 21 is not displaced by means of the coupling rod mechanism 20 and is held in position by the spring device 55 . Since the mechanical resistance is increased by the placement of the support element 10 on the roadway FB, further actuation of the actuating drive 15 and a further extension movement of the actuation rod 34 in a second actuation area adjoining the first actuation area results in the support element 21 being moved by means of the coupling rod 31 is displaced upwards against the force of the spring device 55 in the elongated hole 51 and the support element 21 thus deflects upwards against the force of the spring device 55 . The further actuation of the actuator 15 and the further extension movement of the actuating rod 34 in a second actuation area adjoining the first actuation area, after the support element 10 has been placed on the roadway FB, therefore does not lead to a further extension and a further extension movement of the support element 10.

The support element 21, which is adjustable in the vertical direction V and on which the coupling rod 31 is supported, thus enables further actuation of the actuating drive 15 and the coupling rod mechanism 20, which does not result in further extension, when the adjustable support element 10 is lowered onto the roadway FB and a further extension movement of the support element 10 leads.

With the vertically adjustable and actuated by the coupling rod mechanism 20 support element 21 is thus achieved that the adjustment of the actuating rod 34 of the actuator 15 is variable to a displacement of the support element 10 and a displacement path of the support element 21 divides. The vertically adjustable support element 21 thus enables variable compensation, with which tire wear on the third wheel 6 and/or uneven ground can be compensated for.

In the second operating range, the operating rod 34 of the actuator 15 can thus continue after the placement of the adjustable support element 10 on the roadway FB figure 9 extend right without causing further extension of the support element 10 down until the coupling rods 30, 31 in the figure 10 reach the position shown, in which the coupling rods 30, 31 are vertically one above the other and the coupling rods 30, 31, 32 are arranged like a T. Upon further actuation of actuator 15 in the second actuation range - as soon as the coupling rods 30, 31 are vertically one above the other - the actuating lever 64 is actuated by the coupling rod mechanism 20 and pivoted counterclockwise about the pivot axis S1 against the force of the spring device 70, for example by a or more of the coupling rods 30, 31, 32 come into contact with the actuating surface 68 of the actuating lever 64. By pivoting the actuating lever 64, the toothed elements 62 arranged on the actuating lever 64 engage with the toothed elements 61 arranged on the sliding pieces 50, so that the locking device 60 is urged into the locking position in which the lowered support element 10 is locked.

In the figure 10 the height-adjustable support element 10 is shown in the activated state, in which the support element 10 is in the lowered support position. Opposite of figure 9 When the actuating rod 34 is extended to the right and the coupling rod mechanism 20, the supporting element 10 is lowered down onto the roadway FB and the supporting element 21 is pushed upwards in the elongated hole 51 against the force of the spring device 55 and the actuating lever 64 is actuated to move the locking device 60 into the to actuate the locking position.

When the actuating lever 64 is actuated by the coupling rod mechanism 20, during the locking process, with the toothed elements 61, 62 engaging with one another, the adjustable support element 10 can be moved vertically upwards between 0 mm and the tooth spacing of the teeth V1, V2 of the toothed elements 61, 62 be moved. As a result, a minimum distance between the lowered supporting element 10 and the roadway FB can be ensured. The minimum distance can be easily adjusted via the tooth pitch of the teeth V1, V2 of the toothed elements 61, 62.

In the in the figure 10 When the height-adjustable support element 10 is in the activated state shown, the smallest possible distance between the lowered support element 10 and the roadway FB is provided for maximum residual capacity of the industrial truck 1 on the one hand and ground clearance for maneuvering movements or storage and retrieval maneuvers on the other.

By means of a distance sensor arranged on the support plate 10b, the downward extension of the support element 10 or the placement of the support element 10 on the roadway FB can be monitored and, in the activated state of the support element 10 via the control device 35, only a low driving speed for maneuvering movements or entry and outsourcing maneuvers are permitted.

An independent functional test of the height-adjustable support elements 10 can also be carried out with the control device 35, for example after the industrial truck 1 has been switched on, as well as a functional test and a plausibility check, for example if two height-adjustable support elements 10 are present on the left and right of the industrial truck 1.

Claims (19)

1. Industrial truck (1), in particular a reach truck (2), having two wheels (3) arranged at a distance from each other in the vehicle transverse direction (Q) and a third wheel (6) arranged at a distance from the two wheels (3) in the vehicle longitudinal direction (L), wherein, laterally beside the third wheel (6), the industrial truck (1) has at least one supporting element (10) arranged to be adjustable in height in the vertical direction (V), which is adjustable in the vertical direction (V) by means of an actuating drive (15) between a raised position and a lowered supporting position on a vehicle frame (5) of the industrial truck (1), wherein, in the lowered supporting position, the industrial truck (1) can be supported on a roadway (FB) by using the supporting element (10), wherein the actuating drive (15) is operatively connected by means of a coupling rod mechanism (20) to the supporting element (10) for the actuation of the latter, characterized in that the coupling rod mechanism (20) is supported on a support element (21) which is adjustable in the vertical direction (V) and which, when the supporting element (10) is lowered onto the roadway (FB), permits further actuation of the actuating drive (10) and of the coupling rod mechanism (20).
2. Industrial truck according to Claim 1, characterized in that the third wheel (6) is arranged centrally in the vehicle transverse direction (Q), and two supporting elements (10) are provided at the side of the third wheel (6) .
3. Industrial truck according to Claim 1 or 2, characterized in that the coupling rod mechanism (20) has a first coupling rod (30), which is connected to the supporting element (10) at a first end and is connected to the actuating drive (15) at a second end, and has a second coupling rod (31), which is connected to the support element (21) at a first end and is connected to the actuating drive (15) at a second end.
4. Industrial truck according to Claim 3, characterized in that the actuating drive (15) is connected to the first coupling rod (30) and the second coupling rod (31) by means of a third coupling rod (32).
5. Industrial truck according to one of Claims 1 to 4, characterized in that the actuating drive (15) is formed as a linear drive with an actuating rod (34) that can be extended and retracted.
6. Industrial truck according to one of Claims 1 to 5, characterized in that the supporting element (10) is arranged on the industrial truck (1) via at least one rocker arm (40; 41) such that it can be adjusted in the vertical direction (V).
7. Industrial truck according to Claim 6, characterized in that the supporting element (10) is arranged on the industrial truck (1) by means of two rocker arms (40, 41), which are designed as a parallelogram suspension, such that it can be adjusted in the vertical direction (V) .
8. Industrial truck according to one of Claims 1 to 7, characterized in that the supporting element (10) is biased into the raised position by means of a spring device (45).
9. Industrial truck according to Claim 8, characterized in that the spring device (45) is formed as a tension spring (46), which acts on the rocker arm (40; 41) and on the vehicle frame (5).
10. Industrial truck according to one of Claims 1 to 9, characterized in that the support element (21) is formed as a sliding piece (50) arranged such that it can be displaced longitudinally in a vertical slot (51).
11. Industrial truck according to one of Claims 1 to 10, characterized in that the support element (21) is acted on by a spring device (55) supported on the vehicle frame (5), in particular a compression spring (56).
12. Industrial truck according to Claim 11, characterized in that the pretension of the spring device (55) can be adjusted by means of an adjusting element (57), in particular an adjusting screw.
13. Industrial truck according to one of Claims 1 to 12, characterized in that a locking device (60) which locks the supporting element (10) in the lowered supporting position and which can be actuated between a release position and a locking position is provided, wherein the locking device (60) can be actuated from the release position into the locking position by the coupling rod mechanism (20) during the further actuation of the actuating drive (15).
14. Industrial truck according to Claim 13, characterized in that the locking device (60) has a first toothed element (61) arranged on the support element (21) and provided with toothing (V1), and a second toothed element (62) arranged on an actuating lever (64) and provided with toothing (V2) which, in the locking position, can be brought into engagement with the first toothed element (61).
15. Industrial truck according to Claim 14, characterized in that the actuating lever (64) is arranged such that it can be pivoted and can be actuated by the coupling rod mechanism (20).
16. Industrial truck according to Claim 14 or 15, characterized in that the actuating lever (64) is loaded in the direction of the release position by a spring device (70) supported on the vehicle frame (5), in particular a compression spring (71).
17. Industrial truck according to one of Claims 1 to 16, characterized in that in addition to the supporting element (10) that is arranged to be adjustable in height, a supporting element (11) arranged fixedly on the vehicle frame (5) is provided.
18. Industrial truck according to Claim 17, characterized in that the supporting element (10) that is arranged to be adjustable in height is arranged inside the fixedly arranged supporting element (11).
19. Industrial truck according to one of Claims 1 to 18, characterized in that the actuating drive (15) can be controlled by means of an electronic control device (35), wherein the electronic control device (35) is designed in such a way that the supporting element (10) is controlled depending on the lifting height of a load-carrying means (9) of the industrial truck (1) and/or depending on the speed of travel of the industrial truck (1) .

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