Display device for a forklift truck

Abstract

Display device (3) for a forklift truck (1) with a load handling device (10) which can assume working positions (19, 20, 21, 22, 23), wherein the display device (3) can optically give a signal (13) which is assigned to a working position (19, 20, 21, 22, 23) of the load handling device (10) with respect to a target working position (21), characterized in that the signal (13) is a flashing signal of a light (15; 17; 24) when the load handling device (10) is approaching a position (20, 23) close to the target working position (21).

Description

[0001] The invention relates to a display device for an industrial truck. In particular, the invention relates to a display device for an industrial truck with a load-handling device that can assume working positions, wherein the display device can optically provide a signal associated with a position of the load-handling device relative to a target working position.

[0002] In the case of industrial trucks with a lifting mast, it is known from the prior art to design the lifting mast in such a way that a load-handling device such as a load fork that is movably guided on the lifting mast can be tilted forwards or backwards in the longitudinal direction of the vehicle by a certain angle relative to the vertical direction. On the one hand, this makes it easier to pick up or put down a load using the load handling device, as the device can be aligned relative to the load. On the other hand, it can primarily be used to secure the load during travel. For example, a pallet placed on a load fork is held securely on the load fork by tilting the load fork backwards, preventing it from slipping off the load fork, for example if the industrial truck brakes abruptly.The load handling device can be tilted into various working positions by tilting the load handling device together with the lifting mast as a whole. The mast can be rotated around a transverse axis of the vehicle at a lower mounting point and its inclination can be adjusted by tilt cylinders. In addition, or alternatively, a tilting option for the load handling device relative to the lifting mast or the frame of the industrial truck is also known.

[0003] In this case, the industrial truck operator is repeatedly faced with the task of moving the load handling device into a specific tilt or working position, usually the horizontal position of the load handling device corresponding to the vertical position of the mast in the case of a tiltable mast. Similar problems arise when moving a load handling device on a mast to a lifting height as the working position.

[0004] To assist in precisely approaching a specific incline, it is known to mount an indicator device in the form of a mechanical pendulum or pointer on the tilting mast, for example. It is also known to provide an indicator device within the operator's field of vision that indicates the current inclination of the load-handling device.

[0005] The disadvantage of this state-of-the-art technology is that reading the desired tilt position is often laborious. Whether the desired tilt position has been reached cannot be determined quickly and intuitively.

[0006] Furthermore, it is also known to provide pre-selection systems for fixed tilt positions and to move to these tilt positions automatically or semi-automatically by means of similarly fixed operating steps or by activating an additional switch.

[0007] A disadvantage of this state-of-the-art technology, however, is that in practice, the operating sequence is often perceived as cumbersome and time-consuming. Furthermore, it has been shown that in many cases, simply reaching the desired tilt position is sufficient, even within a certain permissible tolerance. Achieving the desired working position with absolute precision is not absolutely necessary and would require considerably more time.

[0008] From US 5 749 696 A a generic display device for an industrial truck with the features of the preamble of patent claim 1 is known.

[0009] US 5 131 801 A discloses a tilt angle indicator of a load handling device for an industrial truck, which comprises one or more lamps.

[0010] US 5 011 358 A discloses a lifting height and tilt angle display of a load handling device of an industrial truck, wherein a display is provided with several lamps for displaying the lifting height of the load handling device and several lamps for displaying the tilt angle of the load handling device.

[0011] US 8 157 500 B1 discloses a tilt angle indicator of a load handling device of an industrial truck, wherein the tilt angle indicator comprises a plurality of lamps that change when the tilt angle of the load handling device exceeds a preset range.

[0012] WO 2011 / 154 519 A1 discloses a lifting device for lifting and lowering vehicles, wherein the lifting device has a plurality of lighting devices, wherein each lighting device comprises a work space lighting and an operating state display lighting with at least one operating state, wherein different operating states of the lifting device are displayed by color change and / or selection of a predetermined lighting interval or a continuous light and / or different successive lighting sequences.

[0013] The present invention is based on the object of providing a display device for an industrial truck, by means of which the operation of the industrial truck is simplified and the reaching of a desired working position of the load handling device within a certain tolerance becomes possible very quickly.

[0014] The object is achieved by the display device according to the invention as defined in claim 1 and an industrial truck as defined in claim 11. Advantageous embodiments and further developments of the invention are specified in the subclaims.

[0015] The object is achieved according to the invention in that in a display device for an industrial truck with a load-handling device which can assume working positions, wherein the display device can optically give a signal which is associated with a position of the load-handling device in relation to a target working position, the signal is a flashing signal of a light when the load-handling device is approaching the target working position.

[0016] This advantageously allows intuitive and very rapid detection of the fact that an approach position has been reached shortly before the target working position in the movement of the load handling device. This allows sufficiently precise control of a target working position using the normal operating elements of the industrial truck, e.g., a joystick, in a very short time. It is of course also possible to control the target working position very precisely. The display device according to the invention is also easy to retrofit and can be implemented cost-effectively compared to automated control of target working positions. It is also conceivable for the display device according to the invention to store several target working positions, each of which provides approach positions from one or both sides with respect to the direction of movement of the load handling device.A sufficiently precise adjustment is made possible, since reaching the target working position within a certain tolerance is usually sufficient and can be done more quickly than a very precise alignment of the load-bearing device.

[0017] The load-handling device can be tiltable and the working positions can correspond to the inclination of the load-handling device.

[0018] The display device according to the invention is particularly advantageous for tilted load-handling devices, especially for load forks. In these cases, the tilt must be adjusted accordingly each time a load is picked up. At the same time, however, the load-handling device or load fork is regularly tilted during transport to secure the transported goods or load, so that the tilt must be readjusted again when the load is set down, particularly to a horizontal target working position.

[0019] In a further development of the display device, the load-handling device is guided on a lifting mast in a height-adjustable manner and the lifting mast can be tilted to adjust the inclination of the load-handling device.

[0020] Advantageously, the load handling device is guided on a lifting mast in a height-adjustable manner and the working positions correspond to the lifting heights of the load handling device.

[0021] This allows for simple, quick and intuitive adjustment with sufficient accuracy in relation to a lifting height as the target working position.

[0022] In an advantageous embodiment, the display device has the light as an optical signal, in particular an LED, which lights up in the target working position, flashes in the approach position and is otherwise switched off.

[0023] This also makes it clear whether the target working position has been reached and whether there is a large deviation from the target working position.

[0024] Advantageously, the light flashes in a first color in the approach position from a first side, lights up in a second color in the target working position and flashes in the first or a third color in the approach position from the second side.

[0025] This also clarifies the direction of movement required to reach the target working position.

[0026] In an advantageous development, the display device has a first light and a second light as an optical signal, wherein in the target working position the first light and the second light are illuminated, in the approach position from a first side the first light flashes while the second light is switched on, on the first side outside the approach position the first light is illuminated while the second light is switched off, in the approach position from a second side the second light flashes while the first light is switched on, and on the second side outside the approach position the second light is illuminated while the first light is switched off.

[0027] In this alternative embodiment, the direction of a required corrective movement is advantageously indicated by the two different lights for approaching the target working position from the two possible sides. For example, the first light can flash when a load fork, such as a load-handling device, is still tilted forward in an approach position to a horizontal position, and the second light can flash accordingly when tilted backward.

[0028] The first light and the second light can each have the shape of arrows with their tips pointing towards each other.

[0029] The arrows also indicate the direction of a necessary corrective movement.

[0030] It is also conceivable to use the display device according to the invention with regard to the setting of values ​​such as speed specifications or volume flow of an oil volume flow in a working hydraulic system for an attachment.

[0031] The object is also achieved by an industrial truck with a load-handling device that can assume working positions, wherein the industrial truck has a display device as described above.

[0032] The industrial truck offers the advantages already mentioned above. Particular advantages arise from an industrial truck in the form of a forklift truck with a tilting mast and a load-handling device mounted on this mast, as the load-handling device can be aligned horizontally with sufficient precision and very quickly.

[0033] Further advantages and details of the invention are explained in more detail with reference to the exemplary embodiments shown in the schematic figures. Fig. 1 schematically shows an industrial truck in the form of a forklift truck, Fig. 2a schematically shows an optical signal of a display device according to the invention in five working positions, Fig. 2b schematically shows an alternative optical signal of a display device according to the invention in five working positions, and Fig. 2c schematically shows an alternative optical signal of a display device according to the invention in five working positions.

[0034] The Fig. Figure 1 schematically shows an industrial truck 1 in the form of a forklift truck 2, which has the display device 3 according to the invention. Operating devices, such as a steering wheel 6, and the display device 3 are arranged in a driver's cab 4 with a driver's seat 5. A lifting mast 8 with a load fork 9 as a load-carrying device 10 is arranged on a front axle 7. The lifting mast 8 can be tilted by a tilt cylinder 26. A counterweight 12 is located above a rear axle 11.

[0035] The Fig. Figure 2a shows schematically a representation of an optical signal 13 of a display device 3 according to the invention for five working positions 14. The Fig. The working positions 14 shown in Figure 2a as schematic representations of a load fork 9 tilted on a lifting mast do not correspond to an optical signal displayed by the display device 3, but serve solely for explanatory purposes. The optical signal 13 has a first light 15 in the form of a first arrow 16 and a second light 17 in the form of a second arrow 18, the tip of which points to the tip of the first arrow 16. When the load fork 9 is tilted forward outside of an approach position from a first side 19, only the first light 15 lights up to indicate that a "backward" tilting movement is required to reach a horizontal position of the load fork 9 as a target working position 21. When the load fork 9 is in an approach position from the first side 20, the second light 17 lights up and the first light 15 flashes with increasing frequency the more a target working position 21 is reached.In the target working position 21, both the first light 15 and the second light 17 illuminate. If the load fork 9 is tilted backward outside of an approach position from a second side 22, only the second light 17 illuminates to indicate that a "forward" tilting movement of the load fork 9 is required to reach the horizontal target working position 21. When the load fork 9 is in an approach position from the second side 23, the first light 15 illuminates and the second light 17 flashes with increasing frequency the closer the load fork 9 approaches the target working position 21.

[0036] The Fig. Figure 2b shows schematically a representation of an alternative optical signal 13 of a display device 3 according to the invention for the five working positions 14 of the Fig. 2a. In this alternative embodiment, the optical signal 13 consists of a single light 24 in the form of an LED 25. When the load fork 9 is tilted forward outside the approach position from a first side 19, as well as when the load fork 9 is tilted backward outside the approach position from the second side 22, the light 24 is not illuminated. In the approach position from the first side 20, as well as in the approach position from the second side 23, the light 24 flashes with increasing frequency the closer the target working position 21 is reached. In the target working position 21, the light 24 is constantly illuminated.

[0037] The Fig. Figure 2c shows schematically a representation of an alternative optical signal 13 of a display device 3 according to the invention for the five working positions 14 of the Fig.2a. In this alternative embodiment, the optical signal 13 consists of a single light 24 that can illuminate in different colors. When the load fork 9 is tilted forward outside the approach position from a first side 19, as well as when the load fork 9 is tilted backward outside the approach position from the second side 22, the light 24 does not illuminate. In the approach position from the first side 20, the light 24 flashes in a first color with increasing frequency the closer the target working position 21 is reached. In the target working position 21, the light 24 illuminates constantly in a second color. In the approach position from the second side 23, the light 24 flashes in the first or a third color with increasing frequency the closer the target working position 21 is reached.

[0038] By means of the display device 3 according to the invention, it can be detected intuitively and very quickly that an approach position 20, 23 has been reached shortly before the target working position 21 in the movement of the load-carrying device 10 and a sufficiently precise control of the target working position 21 can take place in a very short time.

Claims

[1] Display device (3) for an industrial truck (1) with a load-carrying device (10) which can assume working positions (19, 20, 21, 22, 23), wherein the display device (3) can optically give a signal (13) which is assigned to a working position (19, 20, 21, 22, 23) of the load-carrying device (10) in relation to a target working position (21), characterized by that the signal (13) is a flashing signal of a light (15; 17; 24) at an approach position (20, 23) of the load-carrying device (10) close to the target working position (21). [2] Display device (3) according to claim 1, characterized by that the load-carrying device (10) is tiltable and the working positions (19,20,21,22,23) correspond to inclinations of the load-carrying device (10). [3] Display device (3) according to claim 2, characterized by that the load-carrying device (10) is guided vertically on a lifting mast (8) and the lifting mast can be tilted to adjust the inclination. [4] Display device (3) according to claim 2 or 3, characterized by that the target working position (21) is a horizontal position of a load fork (9) as a load-carrying device (10). [5] Display device (3) according to one of claims 1 to 4, characterized by that the load-carrying device (10) is guided vertically on a lifting mast (8) and the working positions correspond to lifting heights of the load-carrying device (10). [6] Display device (3) according to one of claims 1 to 5, characterized by that the display device (3) has as an optical signal (13) the light (24), in particular an LED (25), which lights up in the target working position (21), flashes in the approach position (20, 23) and is otherwise switched off. [7] Display device (3) according to claim 6, characterized bythat the light (24) flashes in a first color from a first side in the approach position (20), lights up in a second color in the target position (21) and flashes in the first or a third color from the second side in the approach position (23). [8] Display device (3) according to one of claims 1 to 7, characterized byin that the display device (3) has a first light (15) and a second light (17) as an optical signal (13), wherein in the target working position (21) the first light (15) and the second light (17) are illuminated, in the approach position from a first side (20) the first light (15) flashes while the second light (17) is switched on, on the first side outside the approach position (19) the first light (15) is illuminated while the second light (17) is switched off, in the approach position from a second side (23) the second light (17) flashes while the first light (15) is switched on, and on the second side outside the approach position (22) the second light (17) is illuminated while the first light (15) is switched off. [9] Display device (3) according to claim 8, characterized bythat the first light (15) and the second light (17) each have the shape of arrows (16,18) whose tips are arranged pointing towards each other. [10] Display device (3) according to one of claims 1 to 9, characterized by that the blinking frequency increases with increasing approach to the target working position (21). [11] Industrial truck (1) with a load-carrying device (10) which can assume working positions (19, 20, 21, 22, 23) and a display device (3) according to one of claims 1 to 10.

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