Industrial truck, especially order picker

Abstract

Industrial truck, in particular order picker (1), with a drive unit (5) and a load unit (3) that can be raised and lowered vertically relative to the drive unit (5) by means of a lifting device (25), the load unit comprising load arms (2a, 2b) which are supported on a track by means of at least one load roller (10a, 10b) each, wherein the load roller (10a, 10b) is rotatably mounted in a load roller carrier (11a, 11b) which is pivotably arranged on the load arm (2a, 2b) and which is operatively connected to a lifting track (16) arranged on the drive unit (5) by means of a linkage (13a, 13b) and a lever arrangement (15), the lifting track being designed as an inclined surface, characterized in that the lever arrangement (15) comprises a coupling shaft (30) to the outer regions of which the linkages (13a, 13b) are articulated, wherein the The coupling shaft (30) between the linkages (13a, 13b), particularly in the central area, is provided with a single deflection lever (34),which is in operative connection with the lifting track (16), wherein a roller (35) is rotatably arranged on the deflection lever (34), by means of which the deflection lever (34) runs along the lifting track (16) formed by the inclined surface.

Description

[0001] The invention relates to an industrial truck, in particular an order picker, with a drive part and a load part which can be raised and lowered vertically relative to the drive part by means of a lifting device, the load part comprising load arms which are each supported on a track by means of at least one load roller, wherein the load roller is rotatably mounted in a load roller carrier which is pivotably arranged on the load arm and which is operatively connected by means of a linkage and a lever arrangement to a lifting track arranged on the drive part which is designed as an inclined surface.

[0002] Industrial trucks are known as low-lift trucks, high-lift trucks, or order pickers. These trucks can be designed as pedestrian-guided, stand-on, or seated trucks.

[0003] In industrial trucks of this type, the load arms can be raised by approximately 10 to 20 centimeters using the lifting device. The load arms form a load fork on the load side and are attached to a lifting carriage, which is mounted on the drive unit and can be moved vertically using the lifting device. A load located above the load fork, such as a pallet, can be lifted by raising the lifting carriage and thus the load arms and then moved with the industrial truck. This corresponds to the design of a conventional low-lift pallet truck or order picker.

[0004] In addition, in the case of industrial trucks of this type with an initial lift device, the load section can also feature a lifting frame in addition to the elevating load arms, on which a carrying fork is guided for vertical movement. The carrying fork can be used to pick up, transport, and lift loads to heights of several meters, enabling tasks such as stacking loads and operating shelves.

[0005] The lifting device, which generates the force required to lift the load section, generally comprises at least one hydraulic lifting cylinder, which is supplied by a hydraulic pump driven by an electric lifting motor. The lifting motor and hydraulic pump are generally located in the drive section of the pallet truck. Industrial trucks of this type with a liftable load section also have a lever arrangement and a linkage that connect the part of the lifting device located in the drive section to the load rollers arranged on the load arms. These components, which are also part of the lifting device, transmit the lifting movement of the lifting cylinder located in the drive section to the load rollers arranged on the load arms in the load roller carriers in such a way that the vertical distance between the load rollers and the load arms changes synchronously with any change in the length of the lifting cylinder.

[0006] DE 38 08 007 A1 discloses an industrial truck with a drive section and a load section that can be raised and lowered vertically relative to the drive section by means of a lifting device. The load section comprises load arms that are each supported on a track by at least one load roller. The load rollers are rotatably mounted in a load roller carrier that is pivotally mounted on the load arm and actuated by means of a linkage and a lever arrangement. The lever arrangement consists of a lever plate that is welded to a shaft that is rotatably mounted on the load section and to which the linkages are pivoted. The lever plate is pivotally mounted on the drive section by means of a bearing bush. A pivot lever is welded to the bearing bush, to which a hydraulic cylinder is pivoted in a transverse bore. Furthermore, guide rods are provided that enable the load section to be guided parallel to the drive section when raising and lowering the load section.

[0007] EP 1 028 086 B1 discloses an industrial truck designed as an order picker, in which the load section formed by two load arms is arranged on the load section so that it can be raised or lowered by means of a lever arrangement formed by parallelogram levers. When the load section is raised or lowered relative to the drive section, the load section moves along a circular arc, which leads to a movement of the load section relative to the drive section in the longitudinal direction of the vehicle.

[0008] In order to avoid this movement of the load part with respect to the drive part in the longitudinal direction of the vehicle and to achieve a straight vertical movement of the load part when raising and lowering, it is known to provide a lever arrangement for actuating the rods instead of parallelogram levers, which cooperates with a lifting track on the drive part.

[0009] EP 1 690 823 A2 discloses a generic industrial truck designed as an order picker. The load roller supports arranged in the load arms and equipped with load rollers are each connected by means of a linkage to a lever device, which is connected to a lifting track arranged on a vertical frame section. The lever device comprises a vertically arranged deflection lever connected to the corresponding linkage, which is operatively connected to a corresponding lifting track. This requires two deflection levers and two lifting tracks, resulting in a complex design for the lifting device. Furthermore, two lifting tracks and two deflection levers require complex adjustment and adaptation of the load rollers.The vertical arrangement of the two lifting tracks and the two deflection levers also results in the transmission of the support forces on the lifting tracks into the vertical frame section, which is subjected to bending loads due to the support forces on the lifting tracks and, in the case of an asymmetrical load distribution on the two load arms, also to torsional loads. Therefore, the vertical frame section must be designed with corresponding stability. This further increases the construction complexity of the industrial truck.

[0010] The present invention is based on the object of providing an industrial truck of the type mentioned at the outset which has a reduced construction cost.

[0011] This object is achieved according to the invention in that the lever arrangement comprises a coupling shaft, to the outer regions of which the rods are each pivoted, wherein the coupling shaft is provided between the rods, in particular in the central region, with a single bell crank which is operatively connected to the lifting track, wherein a roller is rotatably arranged on the bell crank, by means of which roller the bell crank runs along the lifting track formed by the inclined surface. According to the invention, the two rods connected to the load roller supports are thus pivoted on a coupling shaft, wherein between the pivot points of the two rods the coupling shaft is provided with a single bell crank which is operatively connected to a single lifting track. This makes it possible to reduce the construction effort since only one bell crank and one lifting track are required to actuate the two rods.In addition, the adjustment effort for the load rollers is simplified by only one lifting track and one deflection lever.

[0012] According to a preferred embodiment of the invention, the coupling shaft is pivotally mounted about a horizontal transverse axis on the load part, in particular a lifting carriage of the load part, with the rods being articulated to the coupling shaft at a distance from the transverse axis. Upon rotation of the coupling shaft during the lifting or lowering of the load part via the bell crank located on the lifting track, the rods can be easily actuated and thus the load roller supports pivoted via the coupling shaft pivotable about the transverse axis and the rods articulated to the coupling shaft at a distance from the transverse axis.

[0013] According to an advantageous embodiment of the invention, the transverse axis of the coupling shaft is arranged above the lifting track and the rods over the entire lifting range of the load part. Such an arrangement of the lifting track and the rods below a horizontal plane passing through the transverse axis of the coupling shaft allows for a space-saving design and a space-saving arrangement of the rods, the bell crank, and the lifting track.

[0014] According to an advantageous development of the invention, the lifting track is arranged on a horizontal frame section of the drive part, wherein the deflection lever is arranged essentially horizontally when the load part is lowered and extends in the direction of the drive part. Such a horizontal lifting track, which is arranged on a horizontal frame section of the drive part, enables a favorable force flow and a favorable force introduction of the support forces acting on the lifting track to a horizontal frame section of the drive part, even with an asymmetrical load distribution on the load arms. With a lifting track arranged centrally in the longitudinal direction of the vehicle, a symmetrical introduction of the support forces into the drive part is also achieved. This can further reduce the construction complexity of an industrial truck according to the invention.The essentially horizontal arrangement of the bell crank when the load part is lowered also enables a space-saving arrangement of the bell crank.

[0015] Such a horizontal arrangement of the bell crank is achieved in a simple manner if, according to a preferred embodiment of the invention, the bell crank is arranged tangentially on the coupling shaft.

[0016] According to a preferred embodiment of the invention, the lifting track is designed as an inclined surface of a lifting element arranged on a horizontal frame plate of the drive part between two longitudinal beams of the drive part. A surface, preferably inclined toward the load part, and thus a lifting track for the bell crank, can be easily formed on a lifting element. The attachment and support of the lifting element on a horizontal frame plate between two longitudinal beams of the drive part enables a space-saving arrangement with favorable force flow and favorable force transmission of the supporting forces of the lifting track into the drive part with minimal construction effort.

[0017] If, according to an advantageous development of the invention, the lifting element is arranged on the frame plate in a horizontally adjustable manner in the longitudinal direction of the industrial truck, the position of the load rollers can be adjusted in a simple manner and with good accessibility.

[0018] When designing the industrial truck as an order picker, a more advantageous design is achieved if the lifting track is located below a driver's platform. The lifting track can be installed below a driver's platform that can be raised or fixed to the drive section, requiring minimal space, while still allowing the support forces of the lifting track to be transferred to the drive section with minimal construction effort.

[0019] Further advantages and details of the invention are explained in more detail with reference to the embodiment shown in the schematic figures. Fig. 1 an industrial truck according to the invention in a perspective view, Fig. 2 the industrial truck in a perspective view from below with the load section lowered, Fig. 3 the industrial truck in a perspective view from below with the load section raised, Fig. 4 the industrial truck in a side view with lowered load section, Fig. 5 the industrial truck in a side view with the load section raised, Fig. 6 the load part of the industrial truck in a perspective view

[0020] In the Fig. Figure 1 schematically shows an industrial truck according to the invention designed as an order picker 1, in particular a low-level order picker. It shows a load section 3 comprising two load arms 2a, 2b, which is mounted on a vertical parapet wall 4 of a drive section 5 so that it can be raised and lowered in the vertical direction. The parapet wall 4 is attached to two laterally spaced longitudinal beams 7a, 7b of the drive section 5, which are attached in the front area to another vertical parapet wall 8. Between the two vertical parapet walls 4 and 8, a driver's workstation is formed by a driver's stand platform (not shown), which can be arranged fixedly or so that it can be raised on the drive section 5.Adjacent to the parapet wall 8 and opposite the driver's workplace, a receiving space (no longer shown) for an energy supply unit (for example a battery block), an aggregate space for a drive unit of a drive wheel on the drive part side, a pump motor for supplying a lifting device and power electronics are arranged.

[0021] To support the load part 3 on a roadway, a load roller device formed by two load rollers 10a, 10b is arranged at the ends of the load arms 2a, 2b, which - as can be seen from the Fig. 6 - are rotatably mounted in load roller supports 11a, 11b. The load roller supports 11a, 11b are each pivotably mounted on the load arms 2a, 2b about a horizontal transverse axis 12. For actuation, the load roller supports 11a, 11b are each connected to a rod assembly 13a, 13b designed as a push rod. A lever arrangement 15 is provided for actuating the rod assembly 13a, 13b when raising or lowering the load part 3 relative to the drive part 5, which lever assembly is operatively connected to a lifting track 16 arranged on the drive part 5.

[0022] The load part 3 includes - as in the Fig. 2 to 6 - a lifting carriage 20 provided with the load arms 7a, 7b, which is arranged vertically movable by means of corresponding guide rollers 21 in vertical guides 22 of the parapet wall 4. For raising or lowering the load part 3 relative to the drive part 5, a lifting device 25 formed by two laterally spaced lifting cylinders 24a, 24b is provided. The lifting cylinders 24a, 24b are - as in the Fig. 1 - are attached to a cross connection of the parapet wall 4 and are connected to an upper cross strut of the lifting carriage 20.

[0023] According to the invention, the lever arrangement 15 is formed by a coupling shaft 30, which is pivotably mounted on side plates 31a, 31b of the lifting carriage 20 about a horizontal transverse axis 32. At the outer regions, the coupling shaft 30 is provided with downward-pointing lever arms 33a, 33b, to which the rods 13a, 13b are articulated. Between the lever arms 33a, 33b, the coupling shaft 30 is provided in its central region with a single, single-armed reversing lever 34, which extends in the direction of the drive part 5 and is operatively connected to the lifting track 16. The reversing lever 34 is arranged tangentially to the coupling shaft 30 in the lower region of the coupling shaft 30.

[0024] A roller 35 is rotatably arranged on the reversing lever 34, by means of which the reversing lever 34 runs along the lifting track 16.

[0025] The lifting track 16 is designed as a surface of a lifting element 36 inclined in the direction of the load part 3, which - as in particular the Fig. 2 to 5 - is attached and supported to a horizontal frame section 37 of the drive part 5 between the two longitudinal beams 7a, 7b. The frame section 37 is formed by a horizontal frame plate 38, which is designed as a horizontal flange section of a fastening angle of the parapet wall 4, by means of which the parapet wall 4 is attached to the two longitudinal beams 7a, 7b.

[0026] The lifting element 36, and thus the lifting track 16, is horizontally displaceable in the longitudinal direction of the industrial truck and is adjustable by means of an adjustment means 39. The adjustment means 39 is formed by an adjustment screw which is arranged in a cross strut 40 connecting the longitudinal members 7a, 7b and is operatively connected to the lifting element 36. For attachment to the frame plate 38, the lifting element 36 is provided with a flange plate 41 which is fastened to the frame plate 38, for example by means of several fastening screws arranged in corresponding elongated holes in the flange plate 41. The flange plate 41 is fastened to the frame plate 38 from above, wherein the frame plate 38 is provided with a recess 42 through which the lifting element 36 extends downwards.

[0027] As from the Fig. 2 and the Fig. As can be seen in Figure 4, the lifting element 36 is located within the vertical extension and thus within the height of the longitudinal beams 7a, 7b. The deflection lever 34 is arranged horizontally in the fully lowered position of the load part 3 and is therefore also located substantially within the height of the longitudinal beams 7a, 7b.

[0028] When lifting the load part 3 relative to the drive part 5 by means of the lifting cylinders 24a, 24b, the deflection lever 34 with the roller 35 runs along the lifting track 16 formed by the slope of the lifting element 36, whereby the coupling shaft 30 is pivoted about the transverse axis 32 and thus the load roller supports 11a, 11b are pivoted downwards about the pivot axis 12 via the rods 13a, 13b which are articulated on the coupling shaft 30 and designed as push rods. Fig. 3 and Fig. 5 shows the load part 3 in the fully raised position.

[0029] The transverse axis 32 of the coupling shaft 30 is located above the rods 13a, 13b and above the lifting track 16 over the entire lifting range of the load part 3, whereby an arrangement of the bell crank 34 and the lifting track 16 within the height of the longitudinal beams 7a, 7b and thus below a driver's platform arranged on the longitudinal beams 7a, 7b is achieved.

[0030] By using only one deflection lever 34, which runs along a centrally arranged lifting track 36, as well as the support and fastening of the lifting track 36 to the horizontal frame plate 38 of the drive part 5, a simple structure with a space-saving arrangement of the lever arrangement 15 and the lifting track 16 between the two longitudinal beams 7a, 7b is achieved. In addition, a symmetrical and central introduction of the support forces of the lifting track 16 into the horizontal frame plate 38 and thus the longitudinal beams 7a, 7b of the drive part 5 results, whereby the construction effort can be further reduced due to a favorable force flow. In addition, the adjusting element 39 and the adjustment of the lifting track 36 in the vehicle's longitudinal direction enable simple and quick adjustment and adaptation of the position of the load rollers 10a, 10b on both load arms 2a, 2b.

Claims

[1] Industrial truck, in particular order picker (1), with a drive part (5) and a load part (3) which can be raised and lowered vertically relative to the drive part (5) by means of a lifting device (25), which load part comprises load arms (2a, 2b) which are each supported on a track by means of at least one load roller (10a, 10b), wherein the load roller (10a, 10b) is rotatably mounted in a load roller carrier (11a, 11b) which is pivotably arranged on the load arm (2a, 2b) and which is operatively connected by means of a linkage (13a, 13b) and a lever arrangement (15) to a lifting track (16) arranged on the drive part (5), which is designed as an inclined surface, characterized byin that the lever arrangement (15) comprises a coupling shaft (30), to the outer regions of which the rods (13a, 13b) are each articulated, wherein the coupling shaft (30) is provided between the rods (13a, 13b), in particular in the central region, with a single deflection lever (34) which is operatively connected to the lifting track (16), wherein a roller (35) is rotatably arranged on the deflection lever (34), by means of which roller the deflection lever (34) runs along the lifting track (16) formed by the inclined surface. [2] Industrial truck according to claim 1, characterized by that the coupling shaft (30) is pivotally mounted about a horizontal transverse axis (32) on the load part (3), in particular a lifting carriage (20) of the load part (3), wherein the rods (13a, 13b) are articulated on the coupling shaft (30) at a distance from the transverse axis (32). [3] Industrial truck according to claim 2, characterized bythat the transverse axis (32) of the coupling shaft (30) is arranged above the lifting track (16) and the rods (13a, 13b) over the entire lifting range of the load part (3). [4] Industrial truck according to one of claims 1 to 3, characterized by that the lifting track (16) is arranged on a horizontal frame section (37) of the drive part (5), wherein the deflection lever (34) is arranged substantially horizontally when the load part (3) is lowered and extends in the direction of the drive part (5). [5] Industrial truck according to one of claims 1 to 4, characterized by that the reversing lever (34) is arranged tangentially on the coupling shaft (30). [6] Industrial truck according to claim 4 or 5, characterized by that the lifting track (16) is designed as an inclined surface of a lifting element (36) which is arranged on a horizontal frame plate (38) of the drive part (5) between two longitudinal beams (7a, 7b) of the drive part (5). [7] Industrial truck according to one of claims 4 to 7, characterized by that the lifting element (36) is arranged on the frame plate (38) so as to be horizontally adjustable in the longitudinal direction of the industrial truck (1). [8] Industrial truck according to one of claims 1 to 7, characterized by that the lifting track (16) is arranged below a driver's platform.

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