HEIGHT-ADJUSTABLE PLATFORM STAIRS

Description

[0001] The present invention relates to a height-adjustable platform staircase according to the preamble of claim 1.

[0002] Height-adjustable platform stairs are not yet widespread, unlike passenger lifts, which are used in a variety of ways, including in building cleaning, construction, and event technology, to transport individuals or very small groups of two or three people to a height of several meters above ground level for work, including overhead work. In addition to vertically transporting passenger lifts, there are also those that, like a crane, can lift and swivel a personnel basket on a usually telescopically extendable arm.

[0003] For the essentially vertical transport of a person or persons on a platform of a platform staircase, the platform features a surrounding fall protection device, such as a railing, and is often attached to a telescopic mast. The individual segments of the telescopic mast are moved relative to each other via cables, racks, or other suitable power transmission systems, resulting in a vertical movement of the platform. Various drive concepts are available for moving the mast segments and the platform. Both hydraulic and electric motor-driven units are used.

[0004] If a motor drive is not required, the platform can be moved manually by one person. Due to the relatively solid construction of the telescopic mast, the platform, and possibly the person(s) being transported, this can require considerable effort. The higher the load capacity and the maximum lifting height, the greater the effort required.

[0005] Such a manually operated device is described in WO2012 / 024378 A2. There, the power is transmitted from the manual actuation device via a threaded rod with a trapezoidal thread to spur gears, which in turn act on the mast segments.

[0006] In addition to the physical effort required for such solutions, there is still the problem that access to conventional personnel lifts can only be achieved in the lowest position for safety reasons. However, if additional tools are needed during work, or if the person wishes to leave the platform for other reasons, this is only possible by winding the personnel lift down to its starting position, allowing them to exit. However, this is time-consuming and can delay work considerably.

[0007] DE 84 08 413 U1 describes a height-adjustable work platform solution that allows access at any height. Access is via a height-adjustable ladder. This poses a risk to the user, especially when materials or tools need to be transported upwards. Such a ladder is also prone to errors, as it can easily become jammed or malfunction.

[0008] Manual work platforms also include designs in which the platform, similar to a table, is height-adjustable via four telescopes and a manual hoist, while the stairs, usually in the form of a four-stringer staircase, adjust their height as a passive element. This design is economically unattractive for small platform sizes, especially those smaller than one square meter.

[0009] CN 204716124 U and US 3,664,458 A disclose mobile height-adjustable platform stairs.

[0010] US 441,722 A discloses another height-adjustable staircase.

[0011] Therefore, the object of the present invention is to provide a height-adjustable platform staircase according to the preamble of claim 1, which allows access to the platform at any height setting, allows easy operation of the manually operated height adjustment and can be used quickly and easily anywhere without any safety or stability concerns.

[0012] This object is achieved according to the invention by claim 1. Advantageous embodiments emerge from the subclaims.

[0013] According to the invention, the platform staircase is constructed with a platform and a staircase articulated thereto. Furthermore, it comprises a floor frame and a lifting mechanism for adjusting the height of the staircase. The lifting mechanism comprises at least an upper and a lower part, but may also comprise any number of additional intermediate parts. The upper part is connected, in particular rigidly, to the platform, and the lower part, in particular rigidly, to the floor frame. The height adjustment can be performed mechanically or electrically. Preferably, a lifting mechanism with a manually operated crank is used. This is robust and, for example, resistant to moisture. An electric drive for the lifting mechanism can also be used instead. Additional safety features such as a self-locking gear or an automatic locking device are preferred in this embodiment.

[0014] According to the invention, the height adjustment of the platform stairs is made possible by a tension element, in particular a cable pull, which is connected to the platform or an upper part of the lifting mechanism. The tension element, in particular the cable pull, is deflected by a deflection element, in particular a deflection pulley, which is mounted on the floor frame or on a lower part of the lifting mechanism.

[0015] According to the invention, the staircase is connected to the platform at its upper end, preferably at its end, in an articulated manner. This articulated connection is preferably achieved via joints.

[0016] In the invention, the staircase hinged to the platform is a four-stringer staircase. Two stringers are arranged on each side. The two stringers are arranged parallel to each other on each side. The two stringers form a parallelogram on each side.

[0017] In the invention, the two stiles on each side are connected to each other via a parallelogram guide. The steps are movably mounted on the stiles, so that the treads of the steps remain in a substantially horizontal alignment even when the stiles are moved relative to each other. However, it is also possible for the steps to deviate from the horizontal by a few degrees when adjusting the height of the stairs. This deviation is preferably less than 20 degrees, more preferably less than 10 degrees, and especially less than 5 degrees.

[0018] Preferably, the height-adjustable platform staircase according to the invention is movable. It can thus be moved to any location and adjusted to the required platform height. For this purpose, two casters are attached to the base frame of the staircase and two to the base frame of the lifting mechanism. Fixed casters are preferred for the base frame of the lifting mechanism, and swivel casters for the staircase. The casters also allow the distance between the base frames to be adjusted when the lifting mechanism is activated. During lifting, the base frames are pulled toward each other by the tension element.

[0019] In a preferred embodiment, a spring or spring element is mounted on each side between the two stringers of the four-stringer staircase. This spring or spring element creates a preload between the two stringers. In a preferred embodiment, the spring is designed as a tension spring.

[0020] As already explained above, according to the invention the staircase is articulated at its upper end to the platform, preferably at the front end. This connection is preferably limited to a specific angular range so that the staircase does not lie too flat or too steeply against the platform. For this purpose the stiles of the movable staircase are connected to the platform so that they can be pivoted through a specific angular range. This angular range is limited in that the connection arrangement of at least one stile to the platform has a stop. As a result, the gradient of the staircase during height adjustment is limited to a specified range between a maximum and a minimum. e.g. in the lowest end position to a minimum of 20 degrees to the horizontal, in particular to a minimum of 30 degrees, and in the uppermost end position to less than 70 degrees, in particular to 60 degrees.

[0021] In a preferred embodiment, a stair railing is mounted on the two lower stiles of the movable staircase. Alternatively, the railing can be attached to the upper stiles of the movable staircase, but for ergonomic reasons, attachment to the lower stiles of the movable staircase is preferred.

[0022] According to the invention, two or more telescopic pulleys are preferably provided near the end of the platform opposite the movably mounted staircase, in particular no more than 10 cm from this end. These telescopic pulleys extend between the floor frame and the platform and serve to support the platform against a tilting movement in a transverse direction perpendicular to the extension of the staircase on the platform.

[0023] Preferably, these telescopic hoists and / or the lifting mechanism are connected to the platform at a fixed angle in the transverse direction, in particular at a fixed angle of 90 degrees.

[0024] The telescopic pulleys can be extended or retracted using the lifting mechanism. They are preferably fully extended at the height adjustment stop and fully retracted at the lower height adjustment stop. This design, in addition to the stop for the angle adjustment of the stairs, allows for the creation of an additional mechanism that limits the adjustable height of the height-adjustable platform stairs to a specified range between a maximum and a minimum.

[0025] When the lifting mechanism is operated, the incline of the platform and the steps changes by a certain amount. This is technically determined by the design of the height-adjustable platform stairs. The tension element is connected to the stairs at the bottom on one side and to the platform on the other. The stairs are attached to the side of the platform opposite the tension element's pivot point on the platform. When the lifting mechanism raises the platform, the tension element, which is guided via the deflection element, pulls the stairs with its lower side towards the platform and the lifting mechanism. The stairs assume a steeper position, and the raising of the platform on the stair side goes hand in hand with the raising of the platform on the tension element pivot point side.

[0026] Thanks to the inventive design, the platform remains essentially horizontal, except for a slight tilt of the platform during height adjustment. The steps also remain essentially horizontal during height adjustment. However, due to the fixation to the stiles and their parallelogram movement, small deviations from a perfectly horizontal alignment of the platform may occur.

[0027] This inclination relative to the horizontal lies in a very small percentage range, deviating from the horizontal by less than 3°, in particular less than 2° and most preferably 1.5° in each direction. The inclination of the platform steps is at its maximum deflection in the two end positions and the middle position, i.e. the lowest and highest adjustable heights. The change in inclination during operation of the lifting mechanism is cosine-shaped, from a maximum inclination at the lowest height of the height-adjustable platform steps above the horizontal to a maximum inclination of the height-adjustable platform steps in the other direction and back. In all areas between these extreme settings, the inclination of the steps and the platform is lower.

[0028] In the case of a sinusoidal increase or decrease in inclination, it passes through two positions where the platform is exactly horizontal.

[0029] Preferably, the positions of the horizontal alignment are chosen so that they are exactly in the middle between the maximum deviations.

[0030] The horizontal extension of the platform, and thus its technically determined inclination, can be set and / or adjusted via the height of the platform stairs and thus via the fine adjustment of the length of the tension element.

[0031] In a further embodiment, the traction element is mounted on the platform and / or the stairs in an adjustable manner. The position at which the pulley is mounted on the floor frame can also be adjustable. This allows the height-adjustable platform stairs to be easily adapted to the respective conditions. For example, on very uneven work terrain, such as with tall grass or bushes, the position at which the pulley is mounted on the floor frame of the stairs can be moved upwards, thus allowing greater ground clearance for the movable platform stairs.

[0032] The traction element is attached to the stairs at one end close to the ground, preferably below the second-to-lowest step, and in particular no more than 30 cm from the ground. The other end is attached near the end of the platform opposite the stairs, in particular no more than 10 cm from this end. The traction element runs over the pulley.

[0033] The traction element extends with its essentially horizontal strand parallel to the ground and essentially parallel to the platform.

[0034] In a further embodiment, the telescopic pulleys that support the platform near the end opposite the stairs are spaced from this end by at least 10% of the platform's length. This allows the operating elements of the lifting mechanism, in particular the crank of a mechanical lifting device, to be easily relocated far enough below the platform that the platform stairs can be pushed completely up against a wall without leaving a gap between the platform and the wall. This protects the lifting mechanism, as it cannot be damaged if it is carelessly pushed up against the wall.

[0035] Further advantages, details and features will become apparent from the following description of several embodiments of the invention with reference to the drawings.

[0036] They show: Fig. 1 shows a schematic representation of a height-adjustable platform staircase according to the invention in a side view in one possible embodiment; Fig. 2 shows a schematic representation of a height-adjustable platform staircase according to the invention in a front view in one possible embodiment; Fig. 3 shows schematic representations of a height-adjustable platform staircase according to the invention in a side view in two possible embodiments; and Fig. 4 shows schematic representations of a section of a height-adjustable platform staircase according to the invention in a detailed view in three possible embodiments.

[0037] Fig. 1 shows a schematic representation of a height-adjustable platform staircase according to the invention in a side view in one possible embodiment. The height-adjustable platform staircase 1 is constructed with a platform 3 and a staircase 5 articulated thereto. It also has a floor frame 7 and a lifting mechanism 9, in particular comprising two parts, for adjusting the height of the staircase. In this exemplary embodiment, the floor frame 7 is equipped with rollers 8 on both sides, i.e. on the side of the lifting mechanism 9 (floor frame 7.1) and on the side of the staircase 5 (floor frame 7.2), but can also be designed with fixed supports on the side opposite the staircase 5 (floor frame 7.1) or even be fixed to the floor. According to the invention, the floor frame on the staircase 5 (floor frame 7.2) should be movable, in particular movable, in order to enable height adjustment. However, the mobility of this floor frame 7 must be ensured.2 does not necessarily have to be realized by rollers 8.2. The floor frame 7.2 can also be movable, for example, on rails or by other mobile structures.

[0038] Such mobility of the floor frame 7.2 allows the height-adjustable platform stairs to be moved to any location and to the required platform height. Preferably, four rollers 8 are attached for this purpose – two rollers 8.2 on the floor frame of the stairs (floor frame 7.2) and two rollers 8.1 on the floor frame of the lifting mechanism (floor frame 7.1). These four rollers 8 can be identical, e.g., as swivel casters, but preferably, fixed casters 8.1 are mounted on the floor frame of the lifting mechanism (floor frame 7.1) and swivel casters 8.2 are mounted on the floor frame of the stairs (floor frame 7.2). This arrangement of the various roller types allows easy moving and maneuvering of the height-adjustable platform stairs 1, even in confined spaces.

[0039] Preferably, the rollers 8 on each side, i.e., the two rollers 8.2 on the base frame of the stairs (base frame 7.2) and the two rollers 8.1 on the base frame of the lifting mechanism (base frame 7.1), have a comparatively wide track width. This secures the height-adjustable platform stairs 1 against lateral tipping.

[0040] According to the invention, the height adjustment of the platform stairs 1 is enabled by a tension element 11, in particular a cable pull, which is connected to the platform 3 or an upper part of the lifting mechanism at a first anchoring point 13. This anchoring point 13 is located near the end of the platform 3 opposite the stairs 5, in particular no more than 10 cm from this end. The deflection of the tension element 11, in particular the cable pull, is achieved via a deflection element 15, in particular via a deflection pulley, which is mounted on the floor frame 7.1 or on a lower part of the lifting mechanism 9, in particular close to the ground and / or no more than 30 cm from the ground.

[0041] At its other end, the tension element 11, in particular the cable pull, is connected to the lower part of the staircase 5 at a further anchoring point 17. This anchoring point 17 is preferably located close to the ground, in particular below the second lowest stair step 12 and / or no more than 30 cm from the ground.

[0042] The rollers 8 described above also allow adjustment of the distance between the floor frames 7.1 and 7.2 when the lifting mechanism 9 is actuated. When lifting, the floor frames 7.1 and 7.2 are pulled towards each other by the pulling element 11.

[0043] According to the invention, the staircase 5 attached to the platform 3 is a four-string staircase. The two stringers 21 and 23 of the staircase 5 on each side are arranged parallel to each other. In this embodiment, the two stringers 21 and 23 form a parallelogram with the platform 3 and the floor frame 7.2 on each side.

[0044] The staircase 5 is articulated at its upper end to the platform 3 and at its lower end to the floor frame 7.2. This articulated connection 19 is made via four joints, each attached to the upper and lower ends of each stile 21 and 23. The joints of the lower stiles 21 and the two joints of the upper stiles 23 are coaxial with each other at the top and bottom.

[0045] In this exemplary embodiment, the connection 19 between the stiles 21 and 23 and the platform 3 is limited to a specific angular range, thus preventing the staircase 5 from being too flat or too steep against the platform 3. For this purpose, the stiles 21 and 23 of the movable staircase 5 are connected so as to be pivotable relative to the platform 3 only through a specific angular range. This angular range is determined by the fact that the connection arrangement of at least one stile 21 and / or 23, here both stiles 21 and 23, to the platform 3 has an angle limiting stop 29 that limits the pivoting angle. If there were no such stop 29, the staircase 5 could be pushed onto a gradient steeper than 60° if handled improperly. On such a steep gradient, the height-adjustable platform staircase 1 could potentially tip over.Such an angle limit stop 29 automatically prevents improper handling of the height-adjustable platform stairs.

[0046] The steps 25 are movably mounted on the stiles 21 and 23, so that the treads of the steps 25 remain in a substantially horizontal alignment even when the stiles 21 and 23 are shifted relative to one another, but in particular do not deviate from the horizontal 39 by more than a few degrees.

[0047] In Fig. 1 A spring or spring element 27 is mounted between the two stiles 21 and 23 on each side. However, it is also possible for this spring or spring element 27 to be mounted on only one side of the staircase 5. This spring or spring element 27 creates a pre-tension between the two stiles, which in turn causes increased tension in the tension element 11, particularly in the cable pull, and thus counteracts unintentional pushing together of the floor frames 7.1 and 7.2. The additional tensioning force increases the force for manual height adjustment in the upward direction and slightly reduces it in the downward direction. This design also limits the height adjustment and thus the gradient of the staircase 5. The spring element 27 therefore also serves - like the angle limit stop 29 described above - both to ensure the stability of the height-adjustable platform staircase 1 and to ensure safety.

[0048] In this embodiment, a stair railing 31 is mounted on the two lower stiles 21 of the movable staircase 5. Furthermore, the height-adjustable platform staircase 1 has a railing 33 on the platform 3, which in this embodiment is provided with a door 35. This door 35 can, for example, close like a garden gate, i.e., have only one leaf, but a design similar to a salon door or any other door is also conceivable. The door 35 can preferably close automatically when released by being attached to the railing 33 of the platform 3 by means of hinges and a spring element. The railing can be mounted as in this example, but other attachments are also within the meaning of the invention. For example, it is also possible not to permanently attach the stair railing 31 or the railing 33 of the platform 3, but to allow removal.For example, the railing 33 and / or the stair railing 31 can be removed. This allows for even more flexible use of the platform staircase 1 according to the invention.

[0049] At the end of the platform 3 opposite the stairs 5, one, but preferably several telescopic pulleys 37, particularly preferably two telescopic pulleys 37, are fixedly mounted at a fixed angle. In this embodiment, these are provided approximately 10 cm from the end of the platform 3 opposite the stairs 5. These telescopic pulleys 37 extend between the floor frame 7.1 and the platform 3 and serve to support the height-adjustable platform stairs 1 against a tilting movement in a transverse direction, i.e., here, into or out of the plane of the drawing.

[0050] In this embodiment, the lifting mechanism 9 can be attached either to one of these two telescopic pulls 37, to both, next to one or between both telescopic pulls 37, but should be connected to at least one of the telescopic pulls 37 so that they can be extended or retracted by the lifting mechanism 9.

[0051] Fig. 2 shows a schematic representation of a height-adjustable platform staircase according to the invention analogous Fig. 1 Front view. The height-adjustable platform staircase 1 is constructed with the platform 3 and the staircase 5 hinged to it. It also features a base frame 7 and a lifting mechanism 9 for adjusting the height of the staircase. In this embodiment, the base frame 7 is equipped with casters.

[0052] The stairs 5 attached to the platform 3 and the stair railing 31 attached to it are shown schematically in the background in this embodiment and this view.

[0053] Furthermore, the height-adjustable platform staircase 1 has a railing 33 on the platform 3, which in this embodiment is provided with a double-leaf door 35. The door 35 can preferably close automatically when released, as it is attached to the railing 33 of the platform 3 by means of hinges and a spring element.

[0054] In this version, two telescopic pulleys 37 are fixedly mounted at the end of platform 3 opposite the stairs 5. These telescopic pulleys 37 extend between the floor frame 7.1 and platform 3.

[0055] The lifting mechanism 9 is mounted here between, or more precisely in the middle between, the two telescopic pulleys 37 and is equipped with a crank (as indicated). In this example, the lifting mechanism 9 is a manual lifting mechanism that can be operated manually via the crank. However, electric or other types of mechanical lifting mechanisms are also possible.

[0056] Fig. 3A und 3B show the height-adjustable platform stairs 1 analog Fig. 1 in the two end positions of the height adjustment, namely the lowest ( Fig. 3A ) and highest ( Fig. 3B ) adjustable height. It can be seen that the inclination of the platform 3 and the treads of the steps 25 hardly changes, in particular it deviates by less than 1.5° in each direction from the horizontal 39. The inclination of the platform stairs is here, i.e. in the two end positions and thus the lowest ( Fig. 3A ) and highest ( Fig. 3B ) adjustable height, in its maximum deflection.

[0057] Fig 4A, 4B und 4C show the connection 19 between the stile 21 and the platform 3 in a detailed view. As already mentioned, this connection 19 is limited to a specific angle range, so that the stairs 5 do not rest too flat or too steeply on the platform 3. The stop 29 limits the pivot angle. This limits the gradient of the stairs 5 during height adjustment to a specified range between a minimum ( Fig. 4A ) and a maximum ( Fig 4C ) limited.

Claims

1. A height-adjustable platform staircase (1), comprising a platform (3) and a staircase (5) attached thereto in an articulated manner, comprising a floor frame (7.1, 7.2) and a lifting mechanism (9), in particular comprising two parts, for the height adjustment of the staircase (5), wherein the staircase (5) is connected to the platform (3) or an upper part of the lifting mechanism (9) via a traction element (11), in particular a cable pull, the traction direction of which is deflected via a deflection element (15), in particular via a deflection roller, which is mounted on the floor frame (7) or on a lower part of the lifting mechanism (9), characterized in that the staircase (5) attached to the platform (3) in an articulated manner is a four-bar staircase and in each case two of the four bars (21, 23) of the staircase (5) are arranged on each side, so that the bars (21, 23) span a parallelogram with the platform (3) and the floor frame (7) on each side, and in that the two bars (21, 23) are connected to each other via a parallelogram guide per side and the steps (25) are movably mounted on the bars (21, 23), so that the tread surfaces of the steps (25) remain in a substantially horizontal orientation even when the bars (21, 23) are displaced relative to each other.

2. The platform staircase (1) according to claim 1, characterized in that the staircase (5) is connected in an articulated manner at its upper end to the platform (3), in particular at the end opposite the lifting mechanism (9) and / or an upper articulation point of the traction element (11), in particular via two joints each at the upper end of each bar (21, 23), which joints extend coaxially relative to each other.

3. The platform staircase (1) according to any one of the preceding claims, characterized in that a spring or a spring element (27) is attached on each side between the two bars (21, 23) of the staircase (5) such that it builds up a pretension between the two bars (21, 23), and in particular in that the spring is designed as a tension spring.

4. The platform staircase (1) according to any one of the preceding claims, characterized in that the bars (21, 23) of the movable staircase (5) are connected to the platform (3) such that they can be tilted by a specific angle range, wherein the connection arrangement of at least one bar (21) to the platform (3) comprises a stop (29) which limits the pivoting angle such that the pitch of the staircase (5) is limited to a fixed range between a maximum and a minimum during the height adjustment.

5. The platform staircase (1) according to any one of the preceding claims, characterized in that a staircase railing (31) is mounted on the two lower bars (21, 23) of the movable staircase (5).

6. The platform staircase (1) according to any one of the preceding claims, characterized in that 2 telescopic cables (37) are provided which extend between the floor frame (7) and the platform (3) and serve to support the platform (3) against a tilting movement in a transverse direction.

7. The platform staircase (1) according to claim 6, characterized in that the transverse direction extends transversely to the extent of the staircase (5) on the platform (3).

8. The platform staircase (1) according to any one of the preceding claims, characterized in that the lifting mechanism (9) comprises a middle position which lies between an upper and a lower end position, and in that, in the middle position, the inclination of the platform staircase (1) lies opposite to the inclination of the two end positions.

9. The platform staircase (1) according to claim 8, characterized in that the traction element (11) is adjustably mounted on the platform (3) and / or on the staircase (5), in particular via the position of the deflection roller, and in that the horizontal extent of the platform staircase (1) can be set or adjusted via the traction element (11).

10. The platform staircase (1) according to any one of the preceding claims, characterized in that the traction element (11) is fastened to the staircase (5) below the second-lowest staircase step (12), in particular not more than 30 cm away from the floor, and extends with its substantially horizontal run substantially parallel to the platform (3).

11. The platform staircase (1) according to claim 6, characterized in that the telescopic cables (37) support the platform (3) close to the end which lies opposite the staircase (5), in particular spaced apart from this end by at least 10% of the length of the platform (3).

12. The platform staircase (1) according to any one of claims 6 or 11, characterized in that the telescopic cables (37) and / or the lifting mechanism (9) are connected to the platform (3) in an angularly fixed manner in the transverse direction, in particular at a fixed angle of 90 degrees.

13. The platform staircase (1) according to any one of the preceding claims, characterized in that the telescopic cables (37) and / or the lifting mechanism comprise stops which limit the stroke of the lifting mechanism (9) such that the staircase (5) extends in the lowermost end position at more than 20 degrees to the 10 horizontal (39), in particular at 30 degrees, and in the uppermost end position at less than 70 degrees, in particular at 60 degrees.