The invention relates to a storage and retrieval device having a mast movable along a lower travel rail and an upper guide rail, having a lift truck movable along the mast on a lift guide, having a mast support arranged on the mast side opposite to the lift truck, and having a chassis bearing a running gear for support on the travel rail.
In a known storage and retrieval device of this type (EP 2 502 873 A1), a chassis supported on a travel rail via a running gear is provided, on which the mast is arranged in a middle section. On the mast side facing away from the chassis end having a traction drive, a mast support is linked between the mast and the chassis end opposite to the traction drive. The lift truck, which is movable along the mast on a lift guide, is located on the side of the chassis facing toward the traction drive, and therefore it can be lowered only down to the chassis and not down into the region of the travel rail. Since the mast is pivotably supported on the chassis and the mast support can be adjusted in its length, the mast can be set in its inclined position. The articulated supporting of the mast and the mast support does prevent a torque transmission from the mast to the chassis, however, the chassis is strained by bending as a result of the superimposed load by the mast and its load, which requires a comparatively heavy chassis construction.
So as not to have to accept the lift restriction of the lift truck by the chassis, in addition (EP 2 589 550 A1), arranging the mast at one end of the chassis and supporting it by a mast support linked at the other chassis end, such that a load accommodation means of the lift truck, which protrudes beyond the chassis and is offset downward, can be lowered below the height level of the chassis, is known. However, the prerequisite for this is a storage and retrieval device which is supported on two travel rails, between which the load means may be lowered accordingly. With the arrangement of the mast in the region of a chassis end, bending torques of the chassis as a result of the weight load by the mast can be substantially avoided, but the bending torques which are transmitted by a torque load of the mast on the chassis have to be absorbed.
In order that a mast inclination in the direction of the shelf aisle caused by the bending strain of the chassis can be avoided, in a storage and retrieval device having two masts, between which the lift truck is guided, it is proposed (EP 0 509314 A1), that the two masts not be supported on a common chassis, but rather each on one chassis, specifically in the middle between the running wheels of the chassis coupled to one another, and therefore a symmetrical bending strain of the chassis with respect to the masts results with the effect that the bending of the girders of the chassis accommodating the masts merely cause a vertical displacement of the masts, but not a mast inclination. However, the chassis have to be designed as correspondingly rigid, in order to be able to absorb the bending torques acting on the masts, which occur in particular during the acceleration and deceleration of the storage and retrieval device in the aisle direction.
The invention is therefore based on the object of designing a storage and retrieval device movable along a travel rail such that in spite of a comparatively light construction, the occurring loads can advantageously be dissipated to the travel rail and the restrictions otherwise occurring due to a chassis with respect to the lift truck movement do not have to be accepted.
Proceeding from a storage and retrieval device of the type described at the outset, the invention achieves the stated object in that the mast and the mast support form the chassis, and the running gear has in each case one running gear group arranged on the mast and on the mast support, wherein the two running gear groups are supported in a bearing frame provided at the base of the mast and the mast support.
Since a separate chassis is not provided, which in particular absorbs the superimposed loads due to the mast and its strains and dissipates them via the running gear onto the travel rail, but rather the mast and the mast support themselves form the chassis, a significantly lighter and stiffer construction results in relation to the prior art. Because of the omission of a separate chassis, the running wheels of the two running gear groups, which typically also assume the lateral guiding, are to be provided in bearing frames at the base of the mast and the mast support. These bearing frames can be formed in the case of smaller masts by the mast and/or the mast support themselves. In the case of higher demands on the carrying capacity, separate bearing frames can be used, which are inserted, for example, into the base of the mast and/or the mast support. Since the mast and the mast support are therefore each supported as such via running wheels of separate running gear groups in a load-dissipating manner on the travel rail, the bending torques otherwise occurring in the region of the chassis as a result of the mast accommodation and support are avoided. Moreover, the rigidity of the construction is significantly enhanced.
However, dispensing with a separate chassis is not only accompanied by advantages with respect to a construction simplification and a weight savings, but rather also remedies the restriction given by a separate chassis of the travel path of the lift truck as it is lowered into the lowermost position, because the lift truck can be lowered along the mast down to the travel rail. This applies in particular if the lift guide for the lift truck extends below the upper edge of the travel rail for the running gear. In the case of a predefined guide length for the lift truck, the lift guide extended downward in the region of the travel rail means a shorter guide length for the lift truck above the guide rail, which is accompanied by an enlargement of the travel path of the lift truck in the region of the upper guide rail for the mast.
If the mast and the mast support are connected to form a triangular formation, mast and mast support thus form a construction which meets high strength demands, in particular if this triangular formation is stiffened like a framework or is formed by a connecting plate between mast and mast support. A rigid connection between mast and mast support is in no way required, however. Thus, mast and mast support can also be linked in an articulated manner with one another, wherein the spacing between the running gear groups of the mast and the mast support can be adjustable, for example, by a positioning drive, and therefore, inter alia, influence can be taken on the rigidity of the construction via the spacing between the running gear groups of the mast and the mast support. To accelerate the storage and retrieval device, a greater spacing between the running gear groups can thus be selected, which can be kept small in the end region of the shelf aisles.
If a belt drive is provided for the lift truck, its endlessly guided belt can thus be guided via deflection rollers supported in the bearing frame of the mast base to a drive arranged on the bearing frame of the mast support, in order to ensure an advantageous weight distribution due to the displacement of the belt drive to the side of the mast support. Because of the absence of a separate chassis, there is sufficient space present for this purpose between the mast and the mast support.
A tensioning unit is typically provided for tensioning the endlessly guided belt of the belt drive. In order that this tensioning unit does not restrict the travel path of the lift truck in the lower or in the upper end position, one end of the belt can be fastened on a clamping plate connected in a displacement-fixed manner to the lift truck and the other end of the belt drive can be fastened on a clamping plate adjustable in the belt longitudinal direction with the aid of a tensioning drive, wherein the two clamping plates arranged adjacent to one another overlap one another in the belt longitudinal direction, and therefore the space requirement of the tensioning unit in the belt longitudinal direction substantially corresponds to the length of the clamping plates enlarged by the tensioning path.
A wheel drive, in particular a friction wheel drive interacting with the travel rail or a gearwheel drive interacting with a toothed rack associated with the travel rail can be provided in a typical manner for driving the storage and retrieval device along the travel rail. In this case, arranging the wheel drive on the bearing frame of the mast support suggests itself, to achieve a favorable weight distribution between the running wheels of the mast and the mast support. Instead of a wheel drive interacting with the travel rail or a toothed rack, however, the running gear groups associated with the mast, on the one hand, and the mast support, on the other hand, can be connected to a continuous drive extending along the travel rail, with the aid of which the storage and retrieval device can be moved along the travel rail. The span of the continuous drive connecting the two running gear groups to one another can assume the connection between mast base and base of the mast support in this case, because this span of the continuous drive is only strained by tension as a result of the occurring forces between mast and mast support.
To expand the possible uses of a storage and retrieval device according to the invention, the mast support can have a lift guide for a lift truck, in particular if the mast support engages in the region of the upper end on the mast, and therefore the lift truck of the mast support can also store and retrieve on the full height of the shelf, but this is not required.
Finally, in the case of high demands on the carrying capacity on the side of the mast facing away from the mast support, a mast-parallel guide mast connected to the mast by tension or pressure struts can be provided, which is supported via a running gear group on the travel rail and has a lift drive for the lift truck guided between the mast and the guide mast. Since the guide mast essentially only has to absorb the guide forces for the lift truck, a connection to the mast via pressure or tension struts is sufficient, particularly because the proportional weight of the loaded lift truck is dissipated onto the travel rail via the running gear group associated with the guide mast.
The subject matter of the invention is illustrated by way of example in the drawing. In the figures
The storage and retrieval device according to
The lift truck 15 is movable on a lift guide 16 along the mast 1 and can be moved by means of an endless belt drive 17. The arrangement is made in this case such that the belt 18 of the belt drive 17 is guided via deflection rollers 19 supported in the bearing frame 12 of the mast 1 to a drive 20 arranged in the bearing frame 12 of the mast support 2, via which one reflection roller 21 for the toothed belt 18 is driven. Depending on the rotational direction of the drive 20, the lift truck 15 can thus be moved along the lift guide 16 on the mast 1.
As can be inferred from
A tensioning unit 25 is provided for tensioning the belt 18 of the belt drive 17, which, according to
To drive the chassis formed from the mast 1 and the mast support 2, a wheel gearing is provided, which is designed according to the exemplary embodiment as a friction wheel gearing interacting with the travel rail 3. The lateral guide rollers 10 of the running gear group 7 are laterally pressed as friction rollers against the vertical web of the travel rail 3 and driven via a motor 31.
The exemplary embodiment according to
Moreover, it is indicated in
The base of a storage and retrieval device according to the invention defined by the spacing of the two running gear groups 6 and 7 can also be established according to
In order that heavy loads can also be accommodated by the lift truck 15, according to
Number | Date | Country | Kind |
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A50408/2016 | May 2016 | AT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/AT2017/050009 | 4/28/2017 | WO | 00 |