Guiding device for lifting equipment with scissor device with expansion wedge technology

Abstract

This invention relates to a guiding device for a lifting device with a scissor lift using an expanding wedge technology. The lifting device has an expanding unit for lifting the load, wherein rollers (7) of the expanding unit are each configured to roll on lifting curve tracks of the inner and outer scissor halves of the scissor lift, and wherein the expanding unit is designed to move the rollers (7) toward the scissor lift support of the scissor lift. Here, to stabilize the guiding device of the expanding unit, a triple hinge coupling mechanism (1, 2, 3) with dual kinematic instability is provided, wherein the outer hinge point (5) of the expanding unit is connected to a fixed support by means of the triple hinge coupling mechanism (1, 2, 3). This guiding device reduces axial forces and moments, especially when the lifting device is under uneven load or dynamic load conditions acting on the rollers and lifting curve tracks, thereby significantly reducing the maintenance requirements, particularly for the roller assembly.

Description

Technical Field

[0001] The present invention relates to a lifting device having a scissor lift mechanism using an expanding wedge technique, according to the preamble of claim 1. Background Technology

[0002] Lifting equipment (lifting platform) with scissor lifts based on the principle of expansion wedge technology has high maintenance costs in the roller area of ​​the expansion unit.

[0003] The present invention aims to significantly reduce maintenance costs, improve availability, and expand its application scope by significantly improving the lateral and parallel guidance of the expansion unit along the curved track.

[0004] Existing technology includes scissor lifts with screws driven by expanding wedge technology. Figure 1 As shown in the figure, which will be referred to below, in a scissor lift based on the principle of the expanding wedge, at least one expanding unit 3 moves longitudinally toward the scissor support 5 along a lifting curve track, which is respectively arranged at the inner scissor half 1 and the outer scissor half 2, in order to open the scissor fork. The design of the curve track can advantageously influence both the actuation force of the expanding unit and the force in the transmission system, and can also achieve uniform lifting motion. Furthermore, by using the expanding wedge technology, a very flat structural form of the lifting device can be achieved. However, the expanding unit bears a very high load. To prevent it from running off the lifting curve during lifting motion, i.e., the rollers not jumping off the curve track or similar situations, a lateral guide 4, such as a guide rod, is required.

[0005] In addition to high radial load, axial load F 轴向 The torque M also acts on the expansion unit, and the axial load and torque are distributed through a non-uniform load distribution F in the lateral direction. Δx，负载 And the force F acting laterally on the upper frame 6 横向 Similarly, the tilting of the upper frame relative to the lower frames 6 and 7 via the scissor arms can apply additional torque load to the expansion unit, which also causes the expansion unit to tilt. In belt-actuated lifting platforms, the expansion unit must also absorb the additional torque caused by the uneven belt tension of multiple parallel-running belts. The superposition of the aforementioned unfavorable load conditions places high demands on the lateral and parallel guidance of the expansion unit. The solutions known from the prior art are very maintenance-intensive, wear-prone, and sensitive to torque loads, which limits the application range of the entire lifting equipment and / or leads to increased maintenance costs.

[0006] To prevent rollers from accidentally jumping off curved tracks, it is known to use shaped rollers and curved discs to guide the expansion unit along the curved track. For example, this structure is known from the "scissor lift" by Heckert et al., document DE 101 00 710 C1. However, since the rollers of the expansion unit already bear strong radial loads, the additional axial loads and torques transmitted directly to the rollers via the scissor mechanism and traction mechanism adversely affect the rollers' service life. Furthermore, the relubrication intervals for the rolling pairs must be kept extremely short, as dry running under high loads can lead to premature wear and damage in a short time. Similarly, the shaped rollers and curved discs are very sensitive to shocks and impacts, which can also cause damage and lead to excessive maintenance costs.

[0007] Patent document DE 102 09 387 C1 - Heckert's "scissor lift" illustrates another solution in which the expansion unit is linearly guided by an additional guide unit. However, this structure creates an unfavorable leverage ratio in the lower lifting position because the expansion unit with guide rails and the guide support move away from each other when the scissor section closes, requiring a large design for both the guide support and the guide rails. This negatively impacts the overall size of the scissor lift. Furthermore, high-load linear sliding or rolling guides are very maintenance-intensive. Therefore, it is impossible to provide an economical manufacturing solution and maintenance-free operation.

[0008] Document US 2003 / 0075657 A1 - Joubert's "Scissor lift with combined wedge and lever mechanism" shows an expansion unit with a slider, wherein the guiding function is achieved here by the slider structure and the screw that guides the slider.

[0009] Publication DE 10 2006 006 467 A1 - Neumann's "scissor lift" also shows an expansion unit with a slider.

[0010] Another solution is described in publication DE 10 2010 052 615 A1. Here, a guide element is associated with the axis of the expansion unit for lateral guidance, the guide element acting between the inner scissor blade and the corresponding outer scissor blade. Because the guide element, as previously described, bears a high load, very high wear and consequently high maintenance costs can be adversely inferred due to the relative movement between the expansion unit and the scissor blades. Summary of the Invention

[0011] Therefore, the object of the present invention is to provide a guiding device for a lifting device having a scissor lift with an expanding wedge technology (“expanding wedge-scissor lift”), the guiding device having low maintenance requirements and effectively reducing the axial force and shear torque acting on the rollers.

[0012] The solution to the stated objective includes a lifting device according to claim 1. Here, a guiding device for a lifting device with a scissor lift using an expanding wedge technique is proposed, wherein the lifting device has an expanding unit for lifting the load, wherein the rollers of the expanding unit are each arranged to roll on lifting curve tracks of the inner and outer scissor lift halves, and wherein the expanding unit is designed to move the rollers toward the scissor lift support of the scissor lift. Here, the guiding device for stabilizing the expanding unit has a triple hinged coupling mechanism with dual kinematically indeterminate joints, wherein hinge points (3, 4, 5) are configured as rotation axes, and wherein the outer hinge point of the expanding unit is connected to a fixed support by means of the triple hinged coupling mechanism. The guiding device reduces axial forces and moments, particularly acting on the rollers and lifting curve tracks under uneven loads or dynamic loads, thereby significantly reducing maintenance requirements, especially for the roller arrangement.

[0013] Advantageous designs of the device according to the invention are given in the dependent claims. The features and advantages described herein can be realized individually or in a reasonable combination.

[0014] Connecting the hinge point on the fixed support side to one of the scissor halves provides a compact, space-saving solution. In an alternative embodiment, the hinge point on the fixed plate side can be connected to the base frame or base plate of the lifting device. This saves space within the lifting mechanism.

[0015] Advantageously, the hinge axes of the triple-hinged coupling mechanism are respectively oriented parallel to the axis of the roller. With this embodiment, the roller can be minimized from axial forces on curved tracks, independently of the lifting state.

[0016] In a favorable design, the articulations of the triple articulated coupling mechanism (1, 2, 3) are arranged such that the articulations do not extend beyond the lifting device when the scissor lift is closed, and each articulation is provided with a distance from the dead point of the coupling mechanism during operation. Therefore, impeccable guidance is guaranteed in each lifting position, and collisions between the triple articulated coupling mechanism and the frame or load of the lifting device are eliminated. The distance from the dead point can be achieved, for example, by making the sum of the coupling rods substantially longer than the distance between the outer articulation points of the coupling mechanism in the maximum lifting position.

[0017] In an advantageous variation, at least two of the hinges in the triple-hinged coupling mechanism each have a rotating shaft oriented parallel to the axis of the roller and equipped with at least two rotating or pivoting supports. This embodiment is particularly effective at absorbing torques (“shear moments”) introduced by uneven load distribution or by the dynamic characteristics of the load.

[0018] Especially in long-structured lifting equipment, two guiding devices can be installed, one on the fixed support side and one on the floating support side, to further improve stability. If necessary, this can simplify the structural design of the scissor lift, as the lateral forces and moments acting on the scissor arms are smaller. Attached Figure Description

[0019] Embodiments of the solution according to the present invention are described below with reference to the accompanying drawings.

[0020] This is shown here: Figure 1 The diagram shows a side view, front view, and top view of a lifting device (scissor lift) according to the prior art. Figure 2 – 5 shows schematic diagrams in a plane of four different variations of the solution according to the invention. Figure 6 – 7 shows the basis of the boot device Figure 5 The illustration includes a front view and a side view of a modified technical embodiment, as well as... Figure 8 – 9 shows Figure 6 and Figure 7 A perspective view of a technical embodiment (in the raised and lowered positions of the lifting device, which is not shown). Detailed Implementation

[0021] Figure 1 This illustration shows a scissor lift platform with a screw driven by an expanding wedge technology as a lifting device in the prior art. Here, to open the scissor mechanism, at least one expanding unit 3 moves longitudinally toward the scissor support 5 along a lifting curve track, which is respectively arranged at the inner and outer scissor halves 1 and 2. Lateral guides 4, such as guide rods, absorb axial forces to a limited extent. Figure 1 A lifting platform with a screw drive is shown. However, the guiding device according to the invention described below is also applicable to, for example... Figures 6 to 9 The expansion driver in the flat band technology shown.

[0022] exist Figures 2 to 5The diagram shows four different variations of the invention in a planar view. For illustration purposes, only the lifting curve with the expansion unit and the object according to the invention is arranged on the fixed support side of the scissor lift. Arrangements on the floating support side or both sides are also possible.

[0023] This invention essentially comprises a guiding device with a triple articulated coupling mechanism having a hinge point 4 on the fixed support side, and connecting to an expansion unit at the outermost hinge point 5. The kinematic indeterminacy of the coupling mechanism in the plane allows for a very high degree of flexibility regarding connection and design possibilities. The guiding behavior can be specifically adapted to specific situations through the design of the lengths of the coupling rods 1 and 2, and the positions and dimensions of the hinge points 3 to 5.

[0024] Figure 2 and Figure 3 The variant illustrates two compact, space-saving solutions, in which hinge point 4 on the fixed support side connects to one of the scissor halves. The resulting short length of coupling links 1 and 2 achieves advantageous guiding behavior with minimal manufacturing costs. Figure 2 The modified, ground-level fixation of the scissor arm on the fixed support side provides exceptionally high stability. If no suitable method is available for... Figure 2 or Figure 3 The modified structure is integrated into the structural space of the lifting equipment. Figure 4 and Figure 5 Two variations illustrate alternative embodiments of the invention, wherein the hinge point on the fixed support side is arranged at the upper frame or base / plate of the lifting device.

[0025] exist Figures 6 to 9 The middle shows Figure 5 Exemplary technical implementations of the variant, wherein, Figure 6 Showing the front view, Figure 7 A side view is shown (in the lifting position above the lifting device). Figure 8 and Figure 9 A 3D diagram is shown.

[0026] exist Figures 6 to 9In the illustrated variant, expansion units 5, 6, and 7 are driven by three parallel running flat belts via a centrally located guide roller 6 (not shown). The four running rollers 7 of the expansion units run along the inner and outer lifting curve tracks of the scissor lift, where the coupling mechanisms 1-4, according to the invention, serve a guiding function. However, during integration, care must be taken to maintain a sufficiently large distance from the dead point of the coupling mechanism at all times during operation so that the movement of the expansion units along the lifting curve tracks is not negatively affected. The hinge point 4 on the fixed support side is designed as a bearing seat and can be fixed to the base frame or substrate. Thus, the axial force and torque acting on the expansion units are discharged to the bottom or substrate via the guide mechanism according to the invention (alternatively, under limited conditions, the upper frame of the lifting mechanism is also applicable).

[0027] The core of the invention of the solution shown here lies in designing and integrating a triple articulated coupling mechanism with dual kinematically indeterminate hinge points on the side of the fixed support into any lifting device with a scissor mechanism and an expansion wedge technology, such that high spatial forces and moments are absorbed at the outermost hinge point (where the expansion unit is fixed), and the length of the coupling rods and the position of the hinge points can be flexibly designed so that they are not higher than the upper frame when the scissor section is closed (the lower lifting position of the lifting device), and that there is a certain distance from the dead point of the coupling mechanism during operation, without negatively affecting the compact size of the lifting device.

[0028] Here, the expansion unit is thus unloaded, and large misalignments are prevented, which has a positive impact on wear, especially on the service life of the rollers. Furthermore, the invention allows for highly flexible structural design through its planar freedom, as the lengths of the connection points and coupling rods can be individually adapted to existing conditions, thereby enabling cost-effective retrofitting of existing systems. Compared to solutions with maintenance-intensive linear sliding or rolling guides or pivoting sliding bearing discs, the guide mechanism according to the invention can operate maintenance-free because only a small rotation angle exists in the axis of rotation, and this axis of rotation can be designed economically and with low wear using appropriate sliding bearing implementations. This also enables high resistance to shock, impact, dirt, and dust, and allows for economical construction and operation.

Claims

1. A lifting device having a scissor lift mechanism using expanding wedge technology, in, The lifting device has an expansion unit for lifting the load. The rollers (7) of the expansion unit are each configured to roll on the lifting curve tracks of the inner and outer scissor halves of the scissor fork device, and the expansion unit is designed to move the rollers (7) toward the scissor support of the scissor fork device. Its features are, The lifting device has a guiding device for stabilizing the expansion unit. The guiding device includes a triple hinge coupling mechanism (1, 2, 3) with double kinematic indeterminate structure, wherein the hinge points (3, 4, 5) are configured as rotation axes, and the outer hinge point (5) of the expansion unit is connected to a fixed support member by means of the triple hinge coupling mechanism (1, 2, 3).

2. The lifting device according to claim 1, Its features are, The coupling rod is designed to be without a slider.

3. The lifting device according to claim 1 or 2, Its features are, The rotation axis of the hinge point on the scissor side of the triple hinge coupling mechanism (1, 2, 3) is arranged coaxially with respect to the rotation axis of the roller (7) of the expansion unit.

4. The lifting device according to any one of claims 1 to 3, Its features are, The hinge point (4) on the side of the fixed support is connected to one of the scissor halves.

5. The lifting device according to any one of claims 1 to 3, Its features are, The hinge point (4) on the side of the fixed support is connected to the base frame of the lifting device.

6. The lifting device according to any one of claims 1 to 3, Its features are, The hinge point (4) on the side of the fixed support is connected to the base plate.

7. The lifting device according to any one of the preceding claims, Its features are, The arrangement of the hinges of the triple articulated coupling mechanism (1, 2, 3) is selected such that the hinges do not extend beyond the lifting device when the scissor lift is closed, and each hinge has a distance from the dead point of the coupling mechanism during operation.

8. The lifting device according to any one of the preceding claims, Its features are, The axes of the hinge portions (3, 4, 5) of the triple hinge coupling mechanism (1, 2, 3) are each oriented parallel to the axis of the roller (7).

9. The lifting device according to any one of the preceding claims, Its features are, At least two of the hinges (3, 4, 5) of the triple hinge coupling mechanism (1, 2, 3) each have a rotating shaft that is axially oriented parallel to the roller (7) and has at least two rotating or pivoting supports.

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