Overload testing system

Abstract

In a first embodiment, an overload test system is provided for testing the overload mechanism of a traction system. The overload test system comprises a lower frame, an upper frame configured to be coupled to a traction wire, the upper frame being slidably connected to the lower frame, and a pressing element positioned between the upper frame and the lower frame to move the lower frame relative to the upper frame, wherein the lower frame and the upper frame are provided with passages for receiving the traction wire. In a further embodiment, a method is provided for testing the overload mechanism of a traction system. The method includes positioning the lower frame so as to be placed on the traction system, coupling the traction wire to the upper frame, the upper frame to which the lower frame is slidably connected, and applying a predetermined pressure to increase the traction force acting on the traction wire and to move the lower frame relative to the upper frame.

Description

Technical Field

[0001] This application claims the benefit and priority of European Patent Application Publication No. 23382606.4, filed on June 16, 2023.

[0002] This disclosure relates to an overload test system for testing an overload mechanism of a traction system of a lift device. Further, this disclosure relates to a method for testing an overload mechanism of a traction system of a lift device and a method for setting a load threshold of an overload mechanism of a traction system of a lift device.

Background Art

[0003] A lift device or lift system may be arranged in a structure for transporting goods or users up and down. A service lift device or service lift system is used to raise and lower technical staff or maintenance staff. These service lifts or service elevators may be provided, for example, in wind turbines, construction sites, cranes, silos, chimneys, and various types of towers. A building maintenance unit for performing maintenance work in a high-rise building or structure is also an example of a service lift system.

[0004] A load-carrying structure for transporting people and / or equipment is often in the form of an elevator-like structure that is lifted and / or lowered within a building structure, such as inside a wind turbine tower, and a hoist is used. For example, the load-carrying structure can be a lift platform or a lift cabin. A service lift system or service lift device can include a load-carrying structure suspended within a hoistway or lift path by a wire or wire rope. The load-carrying structure can be a lift cabin or carrier or lift platform, such as within a building maintenance unit.

[0005] A service lift or service lifting device may include a traction system for raising and lowering a load-carrying structure. In some examples, this drive system may be a traction system that uses a traction wire or traction chain. The traction system may be attached to or fitted to the load-carrying structure. The traction system may include a housing that includes a drive or traction mechanism, such as a motor that drives the traction or drive sheave. The motor may typically be an electric motor, but in principle other motors can also be used. The drive mechanism engages with a traction wire or traction chain for raising and lowering the load-carrying structure. Thus, the load-carrying structure may be supported by the traction wire or by the traction chain.

[0006] The use of such service lifts may require compliance with standards and safety regulations. For example, some standards regulate the rated load capacity of load-carrying structures, such as lift cabins or lift platforms. Load sensors or overload mechanisms may be used to prevent the use of load-carrying structures when excessive or overload, i.e., a load exceeding a load threshold, is detected. Load thresholds may be specified for specific applications or for specific types of load sensors or overload mechanisms.

[0007] In some cases, an overload mechanism may be installed within the towing system. The overload mechanism can detect overload by sensing the degree of stretching or pulling applied to the towing wire. When an overload is detected, a warning signal is triggered to alert that the load supported by the load-carrying structure exceeds the load threshold of the overload mechanism. The load threshold is associated with the rated load capacity of the lift system. For example, the load threshold of an overload mechanism is generally related to the rated load capacity, or the rated load capacity multiplied by a safety factor.

[0008] However, these overload mechanisms can wear out or occasionally become misaligned. Consequently, the load threshold of the overload mechanism can change over time. This can lead to the warning signal not being triggered after an overload has been reached. Therefore, the load-carrying structure may not be designed to withstand this excessive load. Thus, to ensure that the load-carrying structure is not carrying an excessive load, the overload mechanism must be inspected and adjusted regularly.

[0009] The overload mechanism can be tested by placing several weights inside the load-carrying structure to stretch the towing wire. If the overload mechanism detects an overload, a warning signal is output. This indicates that the load on the load-carrying structure is greater than the load threshold of the overload mechanism. However, this method suggests that personnel must transport several weights, such as heavy blocks, to the lift system. This can be complex for some lift systems. For example, transporting weights to some wind turbines, such as offshore wind turbines, can be time-consuming and labor-intensive. Furthermore, handling weights can pose safety risks. Additionally, personnel must be inside the load-carrying structure, such as a lift cabin or lift carrier, to test the overload mechanism. This can pose a high safety risk.

[0010] In other examples, a load-carrying structure might be pulled from below to simulate a load. However, this requires attaching a towing system to the underside of the load-carrying structure, which can represent a safety risk. Furthermore, attaching a towing system to the underside of the load-carrying structure can be time-consuming.

[0011] This disclosure provides examples of systems and methods that at least partially address some of the aforementioned shortcomings. [Overview of the project]

[0012] In a first embodiment, an overload test system is provided for testing an overload mechanism of a towing system of a lifting device. The lifting device may comprise a load carrier structure, a towing wire, and a towing system positioned on the load carrier structure to drive the load carrier structure along a lift path. The towing system may comprise a towing mechanism that engages with the towing wire to raise and lower the load carrier structure. The towing system may further comprise an overload mechanism to prevent movement of the load carrier structure when the load on the load carrier structure is greater than a load threshold. The overload mechanism may detect excessive load, i.e., a load on the load carrier structure greater than a load threshold, by sensing or monitoring the degree of towing or stretching applied to the towing wire.

[0013] Lifting devices and lifting systems are used interchangeably in this specification. Lifting devices may be service lifting systems or service lifting devices. For example, a service lifting system may be a building maintenance unit and / or may be installed in a narrow structure, such as inside a wind turbine tower.

[0014] A cargo handling structure is configured to support and transport people and / or equipment along a lift path. The cargo handling structure may be lifted and / or lowered to transport people and / or equipment within the structure. Examples of cargo handling structures may include lift cabins, lift cages, or lift platforms. Lift cages and lift platforms may be used in building maintenance units.

[0015] The overload test system comprises a lower frame and an upper frame configured to be coupled to a towing wire of a lifting device. The upper frame is slidably connected to the lower frame. The lower and upper frames are provided with passages for receiving the towing wire. The overload test system further comprises a pressing element positioned between the upper and lower frames to move the lower frame relative to the upper frame. The lower frame is configured to rest on the towing system of the lifting device.

[0016] When the upper frame is coupled to the traction wire and the lower frame is supported by the traction system, upward movement of the upper frame is prevented. Therefore, relative movement between the upper and lower frames creates a downward pressure toward the load-carrying structure, which causes an increase in the traction force on the traction wire. This increases the degree of stretching. Thus, the stretching of the traction wire can be sensed by an overload mechanism. The overload mechanism may detect excessive stretching of the traction wire, which suggests an excessive load. This can be used to test the function of the overload mechanism. For example, if the pressure applied by the pressing element is greater than the theoretical load threshold of the overload mechanism, and the traction force generated in the traction wire does not trigger a warning signal of the overload mechanism, this may indicate a malfunction of the overload mechanism.

[0017] According to this embodiment, testing of the overload mechanism is simplified, and the testing time for the overload mechanism is significantly reduced. Furthermore, the overload test system may be located in or on the load-carrying structure. Thus, the overload test system can also be installed from the landing platform. Consequently, installation work under the load-carrying structure is avoided. Furthermore, the handling and transport of heavy weights is avoided. As a result, safety risks are reduced. Moreover, the pressure provided by the pressing element can be precisely controlled. As a result, the extension of the traction wire can also be precisely controlled. Thus, the accuracy when testing the overload mechanism can be improved.

[0018] Furthermore, since the lower frame can be supported by a towing system, it can be mounted on a load-bearing structure such as a towing or hoisting mechanism. Thus, high pressure can be exerted by the lower frame toward the load-carrying structure without damaging it.

[0019] In a further embodiment, a method is provided for testing the overload mechanism of a towing system of a lifting device. The lifting device may conform to the lifting device of the previous embodiment. This method includes positioning the lower frame of the overload test system so as to rest on the towing system and coupling the upper frame of the overload test system with a towing wire. The lower frame is slidably connected to the upper frame. Then, a predetermined pressure is applied to move the lower frame relative to the upper frame in order to increase the tensile force exerted on the towing wire.

[0020] This method may employ an overload test system according to any of the examples provided herein. A predetermined pressure generates a predetermined load on the towing wire. This predetermined load may be greater than the expected rated load capacity, or the expected rated load capacity multiplied by a safety factor. Therefore, if the overload mechanism detects excessive stretching of the towing wire before reaching the predetermined load, this may indicate that the overload mechanism is not properly calibrated. In this case, since the load-carrying structure can still withstand a greater load, the load threshold of the overload mechanism can be adjusted to increase its value.

[0021] The advantages derived from this embodiment may be similar to those mentioned with respect to the first embodiment.

[0022] In yet another embodiment, a method is provided for setting a load threshold for an overload mechanism of a towing system of a lifting device. The lifting device may conform to the lifting device of the above-described embodiment. This method includes testing the overload mechanism according to any of the examples herein and adjusting the overload mechanism to set a load threshold corresponding to a predetermined pressure applied to the overload test system.

[0023] According to this aspect, the load threshold of the overload mechanism can be accurately set. The overload mechanism can thus be calibrated to ensure that a warning signal is output when the load is greater than a predetermined load (the load generated by a predetermined pressure). The overload mechanism can thus be accurately adjusted. In this way, the safety risk of using a luggage handling structure with incorrect calibration can be avoided.

Brief Description of the Drawings

[0024] Non-limiting examples of the present disclosure are described below with reference to the accompanying drawings.

[0025] [Figure 1] It is a diagram schematically showing a lift device according to an example of the present disclosure. [Figure 2] It is a diagram showing a traction system according to an example of the present disclosure. [Figure 3] It is a diagram showing the traction mechanism of the traction system of FIG. 2. [Figure 4A] It is a diagram respectively showing an overload mechanism when the traction load is smaller than the load threshold and when the traction load is larger than the load threshold according to an example of the present disclosure. [Figure 4B] It is a diagram respectively showing an overload mechanism when the traction load is smaller than the load threshold and when the traction load is larger than the load threshold according to an example of the present disclosure. [Figure 5] It is a diagram schematically showing an overload test system attached to a luggage handling structure according to an example of the present disclosure. [Figure 6A] It is a diagram respectively showing an overload test system in an initial position and an extended position according to an example of the present disclosure. [Figure 6B] It is a diagram respectively showing an overload test system in an initial position and an extended position according to an example of the present disclosure. [Figure 7A] It is an isometric view of an overload test system according to an example of the present disclosure. [Figure 7B] It is an isometric view of an overload test system according to an example of the present disclosure. [Figure 8] It is a cross-sectional view of the overload test system of FIGS. 7A and 7B. [Figure 9] This figure schematically represents a block diagram of a method for testing the overload mechanism of a towing system of a lifting device, according to an example of the present disclosure. [Modes for carrying out the invention]

[0026] In these figures, the same reference numerals are used to indicate matching elements.

[0027] Figure 1 schematically shows a lifting device having a load handling structure that can move up and down along a lift path. In this example, the load handling structure is a lift cabin 100. In other examples, the load handling structure may be a lift cage or a lift platform.

[0028] In this example, the lifting device is guided via a pair of tensioned wire ropes 121 arranged along a lift path that guides the movement of a cargo transport structure, which in this example is a lift cabin 100. The tensioned wire ropes 121 are positioned on the lateral sides of the cargo transport structure. Thus, the lifting device in this example is a wire-guided lifting system. In other examples, the upward and downward movement of the cargo transport structure may be guided by a structure, for example, the lifting system may be a ladder-guided lifting system.

[0029] The lift system in this example is a service lift system. In particular, the lift system in Figure 1 is a service lift system installed on a wind turbine tower. Therefore, a wind turbine tower may be equipped with the lift system in this example. In other examples, the elevator system may be located on other slender structures or may be a building maintenance unit.

[0030] The lift system in this figure includes a towing wire 110 that extends into the lift cabin or lift carrier 100 and passes through a towing system 140. In this example, the towing system 140 is located inside the lift cabin 100. The towing system 140 may be attached to a support structure of the cargo transport structure, such as the lift cabin 100. An opening 102 formed in the upper wall 101 of the lift cabin 100 allows the towing wire 110 to enter the lift cabin 100.

[0031] In this figure, the lift system or lifting device further comprises a safety wire 120. The safety wire 120 passes through a fall prevention device 130 connected to the lift cabin 100. The fall prevention device 130 may include an overspeed detector and a blocking system for preventing the lift cabin 100 from moving when an overspeed is detected by the overspeed detector. In this example, the fall prevention device 130 is engaged with the safety wire 120. However, in other examples, the fall prevention device may be directly engaged with the towing wire 110.

[0032] Figures 2 and 3 represent the towing system and towing mechanism of the lift system of Figure 1, respectively. The towing system 140 comprises a towing hoist or towing mechanism 150 located within a housing 151. The housing 151 encloses the towing mechanism 150. The towing wire 110 enters the housing 151 through an inlet hole 152 located in the upper part 154 and exits through an outlet hole 153 located in the bottom part 155 of the housing 151. In this example, the towing wire 110 passes completely around the towing sheave 160 and then exits the towing mechanism 150 through the outlet hole 153. In this example, the towing wire guide 161, the first pressure roller 162, and the second pressure roller 163 ensure that the towing wire 110 maintains contact with the towing sheave 160 along its entire circumference.

[0033] The traction system 140 in this example further comprises an electric motor 141 that drives a traction sheave 160 via a gear system 142 having one or more stages. The rotation of the traction sheave 160 causes the traction wire 110 to rise or fall. A cargo transport structure, such as a lift cabin 100, can thus be moved upward or downward. The traction system 140 may further comprise an electromagnetic brake that engages with a rotating part of the traction system 140, such as the shaft of the motor 141, the gears or shafts of the gear system 142, or the traction sheave 160. When power is supplied to the electromagnetic brake, the electromagnetic brake is released, causing the traction sheave 160 to rotate and potentially causing vertical movement of the cargo transport structure. Conversely, when power is not supplied to the electromagnetic brake, the brake pads prevent the rotation of the traction sheave 160 and prevent vertical movement of the cargo transport structure.

[0034] The towing system 140 in this example further comprises an overload mechanism 170. The overload mechanism 170 continuously measures the load supported by a load-carrying structure, such as a lift cabin 100 or a lift platform. In this example, the overload mechanism 170 measures the degree of stretching of the towing wire 110. Thus, the tensile force of the towing wire 110 is continuously monitored by the overload mechanism 170. The overload mechanism 170 in this example is located within the housing 151 of the towing mechanism 150. The overload mechanism 170 in this example is located between the inlet hole 152 and the towing sheave 160.

[0035] Figures 4A and 4B show, respectively, an overload mechanism according to an example of the present disclosure, for when the traction load is less than a load threshold and when the traction load is greater than a load threshold. The overload mechanism 170 in these figures is located inside the traction mechanism 150. In these figures, the overload mechanism 170 is located between the inlet hole 152 of the traction mechanism and the traction wire guide 161 around the traction sheave 160. The inlet hole 152 in this example includes an inlet hole bushing 156 that defines the opening of the inlet hole 152. The overload mechanism 170 includes a swivelable bracket 171 and a swivelable roller 172 that rotates toward an overload switch 173 as the traction force of the traction wire 110 increases.

[0036] In Figure 4A, the traction force on the tow wire 110 is lower than the load threshold set by the overload mechanism 170. As the traction force on the tow wire 110 increases, the bracket 171 rotates toward the overload switch 173. The extension of the tow wire 110 is thus continuously monitored by the overload mechanism 170. As shown in Figure 4B, when the extension or traction reaches the load threshold defined by the overload mechanism 170, the bracket 171 contacts the overload switch 173, and the overload mechanism 170 may output a warning signal. In some examples, the movement of the cargo transport structure may also be prevented when the overload switch 173 contacts the bracket 171.

[0037] The position of the overload switch 173 can be changed by the extension of a spring 174, which can be adjusted via a screw 175. The screw 175 may be rotated with a suitable tool from outside the load handling structure, for example, from outside the lift cabin 100. By changing the extension of the spring 174, the load threshold defined by the overload mechanism 170 can be adjusted.

[0038] Figure 5 schematically shows an overload test system mounted on a cargo handling structure according to an example of the present disclosure. The overload test system 10 is mounted on a lift cabin 100. However, in other examples, the overload test system 10 may be mounted inside the lift cabin 100 or in other types of cargo handling structures. The lift system in this example may follow any of the examples herein. The towing wire 110 passes through the opening 102 and the upper wall 101 of the lift cabin 100 towards the towing system (not visible in Figure 5). The towing system in this example is located inside the lift cabin 100.

[0039] The lift system in this example further includes a safety wire 120 that passes through a fall prevention device 130 located inside the lift cabin 100.

[0040] The overload test system 10 comprises a lower frame 20 and an upper frame 30. The upper frame 30 is slidably connected to the lower frame 20. The lower frame 20 and the upper frame 30 are provided with passages 21, 31 for receiving a traction wire 110. Thus, the traction wire 110 extends along the upper passage 31 and the lower passage 21.

[0041] The overload test system 10 in this example further comprises an upper bushing 50 and a lower bushing 40. The upper bushing 50 and the lower bushing 40 surround the traction wire 110 and are positioned inside the corresponding passages 31 and 21, respectively. Thus, the upper bushing 50 and the lower bushing 40 are configured to fit into the corresponding passages 21 and 31 and to receive the traction wire 110.

[0042] In this figure, the lower frame 20 is mounted on the towing system 140. Therefore, the lower frame 20 is configured to be mounted on or supported by the towing system 140. The lower frame 20 may be supported by the housing 151 of the towing mechanism 150, for example by the upper portion 154 of the housing 151 of the towing mechanism 150. In some examples, the lower bushing 40 has engaging portions that engage with the towing system 140, such as the inlet hole bushing 156 of the towing mechanism 150. Thus, pressure from the lower frame 20 can be effectively transmitted to the lift cabin 100 via the towing system 140, for example by the towing mechanism 150, without damaging the lift cabin 100.

[0043] The upper frame 30 in this figure is held in place by a wire clamp 60 positioned above the upper frame 30. In this example, the wire clamp 60 grips the towing wire 110. This prevents the wire clamp 60 from moving upwards. Thus, the upper frame is configured to be coupled to the towing wire 110. The upper bushing 50 may have an engaging portion that engages with the wire clamp 60.

[0044] The overload test system further comprises a pressing element 70 positioned between the upper frame 30 and the lower frame 20 to move the lower frame 20 relative to the upper frame 30. In this example, the pressing element 70 is configured to extend from an initial position to an extended position. When the upward movement of the upper frame 30 is prevented by the wire clamp 60, the extension of the pressing element 70 causes the lower frame 20 to move downward, which pushes the lift cabin 100. The downward movement of the lift cabin 100 can be prevented by the electromagnetic brake of the traction mechanism 150. Thus, the pressure exerted on the lower frame 20 and the upper frame 30 by the pressing element 70 causes the traction wire 110 to stretch. This increase in the traction force of the traction wire 110 is monitored by the overload mechanism 170.

[0045] Figures 6A and 6B show an example of an overload test system in its initial and extended positions, respectively. In Figure 6A, the overload test system 10 is in its initial position, and the pressing element 70 is not applying pressure to the upper frame 30 and the lower frame 20. In Figure 6B, the pressing element 70 is applying pressure to the upper frame 30 and the lower frame 20. This pressure causes the lower frame 20 to move relative to the upper frame 30, and the traction wire 110 extending through holes made in the upper frame 30 and the lower frame 20 to stretch.

[0046] In these figures, the lower bushing 40 surrounds the towing wire 110 and is positioned within the passage of the lower frame 20, while the upper bushing 50 also surrounds the towing wire 110 and is positioned within the passage of the upper frame 30. The lower bushing can be placed on the towing system, and the upper bushing is prevented by a wire clamp 60 that is clamped onto the towing wire 110. Since the upward movement of the upper frame 30 is restricted by the wire clamp 60, the relative movement caused by the pressing element causes the lower frame 20 to move downward, and consequently causes the towing system and the load-carrying structure to move downward.

[0047] In this example, the pressing element 70 comprises a hydraulic cylinder. In other examples, other types of pressing elements, such as pneumatic or mechanical pressing elements, may be used instead. The hydraulic cylinder may extend from a lower end connected to the lower frame 20 to an upper end connected to the upper frame 30. The distance between the lower and upper ends may increase when a predetermined pressure is applied to the hydraulic cylinder. Thus, the hydraulic cylinder may extend when a predetermined pressure is applied. This makes the upper frame 30 movable relative to the lower frame 20.

[0048] The hydraulic cylinder in this example is configured to be connected to a hydraulic power source. Therefore, the pressure applied to the upper and lower frames can be controlled. This allows a predetermined pressure to be applied. The pressure source may provide a specific pressure. The pressure generated by the pressure source may be selected to generate a predetermined load on the traction wire, i.e., a specific degree of stretching on the traction wire 110. The predetermined load on the traction wire 110 generated by the predetermined pressure may be the rated load capacity multiplied by a safety factor.

[0049] In some examples, the pressure source may be a manual pump. The manual pump may be connected to a hydraulic cylinder via a hose. The manual pump may provide a specific pressure to the pressing element. When the manual pump is activated, oil is released from the manual pump to the pressing element.

[0050] In these figures, a first connecting assembly 80 is connected to the upper frame 30 and slides through a slot 25 located in the lower frame 20. The first connecting assembly 80 in these figures comprises an upper roller 81 and a lower roller 82. The upper roller 81 and the lower roller 82 are rotatably connected to the upper roller and can move up and down along the vertical slot 25. Thus, the relative movement between the upper frame 30 and the lower frame 20 is restricted by the slot 25.

[0051] Although not shown in these figures, the overload test system may include a second connecting assembly that is connected to another side of the upper frame 30 and slides through a slot located on another side of the lower frame 20.

[0052] Figures 7A and 7B are isometric views of an overload test system according to an example of the present disclosure, and Figure 8 is a cross-sectional view of the overload test system shown in Figures 7A and 7B.

[0053] The overload test system 10 in this example includes a wire clamp 60 for clamping a tow wire (not shown in these figures). The wire clamp 60 is positioned above the upper frame 30 and restricts movement upward of the upper frame relative to the lower frame 20. The wire clamp 60 includes a first clamping component 61 and a second clamping component 62 for surrounding the tow wire. Connectors may be used to connect the first clamping component 61 to the second clamping component 62 to clamp the tow wire. In this example, multiple connectors 63 connect the first clamping component 61 and the second clamping component 62, pressing the first clamping component 61 and the second clamping component 62 against each other to clamp the tow wire between them. The wire clamp 60 can thus be mounted at any desired position on the tow wire. The connectors may include screws and nuts that are tightened with a specific pressure to ensure a secure connection of the wire clamp 60 relative to the tow wire.

[0054] In these figures, the upper bushing 50 is positioned below the wire clamp 60 and connects the upper frame 30 to the tow wire in a fixed position. In these figures, the upper bushing 50 comprises a first bushing component and a second bushing component to surround the tow wire. The bushing components may be joined together to encircle the tow wire. For example, an annular pressing element may be placed to surround and press the bushing portion. This configuration allows the upper bushing 50 to be attached to an existing tow wire.

[0055] The upper bushing 50 in these figures includes an insertion portion 51 configured to be inserted into a passage 31 of the upper frame 30. The outer diameter of the insertion portion 51 is smaller than the diameter of the passage 31. Thus, the insertion portion 51 can be fitted into the passage 31 of the upper frame 30. The upper bushing in this example further includes a stopper portion 52 for preventing the entire insertion of the upper bushing into the passage 31. The stopper portion 52 in these figures has an outer diameter smaller than the diameter of the passage 31 in order to prevent the insertion of the stopper portion 52 into the passage 31.

[0056] Furthermore, the upper bushing 50 in this example includes an engaging portion 53 that engages with the wire clamp 60. The uppermost region of the engaging portion 53 can be received within the passage defined by the wire clamp 60. The stopper portion 52 is positioned between the engaging portion 53 and the insertion portion 51.

[0057] In this example, the upper bushing 50 engaged with the wire clamp 60 allows the upper frame 30 of the overload test system 10 to be fixedly connected to the towing wire.

[0058] Similar to the upper bushing 50, the lower bushing 40 in these figures comprises a first bushing component and a second bushing component for surrounding the towing wire. The lower bushing 40 in this example comprises an insertion portion 41, a stopper portion 42, and an engaging portion 43. The insertion portion 41 is configured to fit into a passage 21 of the lower frame 20. The outer diameter of the insertion portion 41 is smaller than the inner diameter of the passage 21 of the lower frame so that it can be inserted into the passage 21. The stopper portion 42 has an outer diameter larger than the inner diameter of the passage 21 to prevent the stopper portion 42 from being inserted into the passage 21. The engaging portion 43 may engage with the towing system, for example, by fitting into an inlet hole of a towing mechanism.

[0059] In this example, the lower frame 20 comprises a base 22 with a passage 21. The lower frame 20 further comprises a first side wall 23 and a second side wall 24. The side walls 23 and 24 extend vertically from the base 22. Thus, the lower frame 20 may have a substantially U-shape. The side walls 23 and 24 may be welded to the base 22. The side walls 23 and 24 in these figures are provided with vertical slots 25 for guiding the vertical movement of the upper frame 30 relative to the lower frame 20.

[0060] In this example, the upper frame 30 comprises a base 32 with a passage 31 and two side walls 33, 34 extending perpendicularly from the base 32. Thus, the upper frame 30 has a substantially U-shape. The base 32 is supported by the flat portions of the side walls 23, 24 of the lower frame 20. The first side wall 33 and the second side wall 34 of the upper frame 30 extend toward the base 22 of the lower frame 20.

[0061] In this example, the side walls 33 and 34 of the upper frame 30 are positioned between the side walls 23 and 24 of the lower frame 20. Thus, the upper frame 30 can substantially engage with the lower frame 20. In other examples, the side walls 23 and 24 of the lower frame 20 may be positioned between the side walls 33 and 34 of the upper frame 30. The pressing element 70 in this example is positioned between the side walls 33 and 34 of the upper frame 30 and between the side walls 23 and 24 of the lower frame 20.

[0062] In this example, the pressing element 70 is a hydraulic cylinder. The hydraulic cylinder has an upper end connected to the base 32 of the upper frame 30 and a lower end connected to the base 22 of the lower frame 20. Therefore, the lower frame 20 is moved relative to the upper frame 30 by the stretching and compression of the pressing element 70.

[0063] In this example, the overload test system 10 includes a first connecting assembly 80 that slidably connects the first side walls 23, 33, and a second connecting assembly 85 that slidably connects the second side walls 24, 34. The first connecting assembly 80 is rotatably connected to the first side wall 33 of the upper frame 30 and slidably connected to the first side wall 23 of the lower frame 20 via a slot 25. The second connecting assembly 85 is rotatably connected to the second side wall 34 of the upper frame 30 and slidably connected to the second side wall 24 of the lower frame 20 via a slot 25 in the second side wall 24.

[0064] The connecting assemblies 80 and 85 in these figures comprise upper and lower rollers. The rollers are rotatably connected to the side walls 33 and 34 of the upper frame 30. These rollers can move through slots in the side walls 23 and 24 of the lower frame 20.

[0065] Figure 9 schematically shows a block diagram of a method for testing the overload mechanism of a towing system of a lift system according to one embodiment of the present disclosure. The overload mechanism 170, the towing system 140, and the lift system may conform to any of the examples herein. Method 500 may employ the use of the overload test system 10 according to any of the examples herein.

[0066] Method 500 includes positioning the lower frame 20 of the overload test system 10 so that it rests on the traction system 140, as shown in block 510. The lower frame 20 may be positioned on the inlet hole 152 of the traction mechanism 150 of the traction system 140.

[0067] In some examples, positioning the lower frame 20 to rest on the traction system 140 may include positioning the lower bushing 40 to rest on the traction system and inserting the traction wire 110 into the lower bushing 40. The traction wire 110 may be received by the lower bushing 40 by placing a first bushing component and a second bushing component around the traction wire 110. These bushing components may then be connected to surround the traction wire 110.

[0068] The engaging portion 43 of the lower bushing 40 may rest on the inlet hole bushing 156 of the traction mechanism 150. The engaging portion 43 may be inserted into the inlet hole bushing 156. The bushing component may be placed around the traction wire 110 and then slide through the traction wire to engage with the traction mechanism, for example, the inlet hole 152 or the inlet hole bushing 156. A portion of the lower bushing 40, such as the insertion portion 41, may be inserted into the passage 21 of the lower frame 20. This insertion may be stopped by a stopper portion 42 that can contact the lower surface of the base 22 of the lower frame 20. Thus, the traction wire 110 and the insertion portion 41 of the lower bushing 40 can be received by the passage 21.

[0069] Method 500 further includes connecting the upper frame 30 of the overload test system 10 to the traction wire 110, as shown in block 520. The lower frame 20 is slidably connected to the upper frame 30. The upper frame 30 and the lower frame 20 may conform to any of the examples herein.

[0070] The upper frame 30 may be connected to the towing wire 110 when the lower frame 20 is placed on the towing system 140. In some examples, connecting the upper frame 30 to the towing wire 110 includes placing an upper bushing 50 above the upper frame 30 and inserting the towing wire into the upper bushing 50. The towing wire may be inserted into the upper bushing and may include placing a first bushing component and a second bushing around the towing wire 110. Thus, the bushing component can surround the towing wire 110.

[0071] Connecting the upper frame 30 to the towing wire 110 may include inserting the upper bushing 50 into the passage 31 of the upper frame 30. The upper bushing 50 surrounding the towing wire 110 may slide through the towing wire toward the passage 31. The insertion portion 51 of the upper bushing 50 may be inserted into the passage 31. The insertion of the upper bushing 50 may be stopped by the stopper portion 52 of the upper bushing 50. Thus, the upper bushing 50 surrounding the towing wire 110 is housed within the passage 31.

[0072] In some examples, connecting the upper frame 30 to the towing wire 110 involves positioning the wire clamp 60 so that it rests on the upper bushing 50. Thus, the towing wire 110 can be clamped by the wire clamp 60 to prevent it from moving upward on the upper frame 30. Thus, the upper frame 30 can be fixedly connected to the towing wire 110. In some examples, clamping the wire clamp 60 onto the towing wire 110 may involve connecting a first clamping component 61 to a second clamping component 62 to press the towing wire 110 between them. The wire clamp 60 may be positioned so that it rests on the upper bushing 50 located inside the passage 31 when the lower bushing 40 is positioned on the passage 21 and rests on the towing system 140.

[0073] As shown in block 530, method 500 further includes applying a predetermined pressure to move the lower frame 20 relative to the upper frame 30 in order to increase the traction force exerted on the traction wire 110. The predetermined pressure is selected to generate a predetermined load on the traction wire 110. This predetermined load may be the rated load capacity, or the rated load capacity multiplied by a safety factor. The predetermined load is the load that should theoretically trigger the operation of the overload mechanism; in other words, the predetermined load should theoretically correspond to a load threshold set by the overload mechanism. In an elevator installed in a wind turbine, this predetermined load may be the rated load capacity of the lift system multiplied by a safety factor equivalent to 1.25.

[0074] In some examples, if the pressing element is a hydraulic cylinder, this method may further include connecting the hydraulic cylinder to a hydraulic source. The hydraulic source may be a manual pump. Then, hydraulic pressure may be actuated, for example, by an operator releasing oil by operating a manual pump, thereby providing a predetermined pressure to the hydraulic cylinder. The manual pump may be connected to the hydraulic cylinder and may provide dynamic pressure to the pressing element. Thus, the traction load applied to the traction wire can be gradually increased. This allows for precise increases in the load on the traction wire. The overload mechanism can thus be precisely tested.

[0075] Methods for testing overload mechanisms can be used to calibrate them. For example, if the threshold load is greater than a given load, the threshold load of the overload mechanism may be reduced. Conversely, if a given load is greater than the threshold load, the threshold load may be increased.

[0076] A method for setting a load threshold for an overload mechanism is provided. The overload mechanism 170, the traction system 140, and the lift system may conform to any of the examples herein. The method for setting a load threshold includes testing the overload mechanism 170 according to any of the examples herein and adjusting the overload mechanism 170 to set a load threshold corresponding to a predetermined pressure applied to the overload test system.

[0077] A predetermined pressure may be selected to generate a predetermined load on the traction wire 110. This predetermined load may be the maximum lift capacity, or the maximum lift capacity multiplied by a safety factor. Therefore, the predetermined load is the theoretical load threshold of the overload mechanism. However, as previously described, the load threshold can become misadjusted over time.

[0078] The pressing element 70 may exert progressive pressure on the upper frame 30 and the lower frame 20. This increase in pressure causes an increase in the traction force on the traction wire 110, which is continuously monitored by the overload mechanism 170. The overload mechanism 170 triggers a warning signal when the traction force on the traction wire 110 exceeds the load threshold of the overload mechanism 170.

[0079] In some examples, the overload mechanism 170 triggers a warning signal before reaching a predetermined load. Therefore, the load threshold is lower than the predetermined load. Thus, the load threshold of the overload mechanism 170 can be adjusted. Thus, the load threshold can be increased. The overload mechanism may be adjusted to increase the load threshold until the overload mechanism 170 outputs a warning signal when a predetermined pressure is applied.

[0080] If the load threshold is lower than a predetermined load caused by a predetermined pressure, the method for setting the load threshold of the overload mechanism 170 may include increasing the load threshold until the overload mechanism 170 outputs a warning signal when the predetermined pressure is applied.

[0081] In some cases, the overload mechanism 170 may not trigger a warning signal when a predetermined load is applied. Therefore, the load threshold is greater than the predetermined load. The overload mechanism 170 may therefore be adjusted to reduce the load threshold. If the load threshold is greater than a predetermined load caused by a predetermined pressure, the method for setting the load threshold of the overload mechanism 170 may include reducing the load threshold until the overload mechanism 170 no longer outputs a warning signal when the predetermined pressure is applied.

[0082] The overload mechanism may be adjusted from outside the load handling structure, for example, from outside the lift cabin. A tool may be used to rotate the screw 175 to change the extension of the spring 174. The position of the overload switch may be adjusted in this way. Thus, the load threshold can be adjusted.

[0083] For reasons of completeness, various aspects of this disclosure are presented in the following numbered clauses.

[0084] Clause 1: An overload test system for testing the overload mechanism of the traction system of a lifting device. Lower frame and An upper frame configured to be coupled to a towing wire of a lifting device, wherein the upper frame is slidably connected to a lower frame, It comprises a pressing element positioned between the upper frame and the lower frame, which moves the lower frame relative to the upper frame, An overload testing system in which the lower and upper frames are equipped with passages for receiving a towing wire.

[0085] Clause 2: Further comprising a wire clamp for clamping a tow wire above the upper frame to prevent upward movement of the upper frame, the wire clamp is, The first clamping component, The second clamping component, The overload test system according to Clause 1, comprising a connector that presses a first clamping component and a second clamping component together to clamp a traction wire between the first clamping component and the second clamping component.

[0086] Clause 3: The overload test system according to Clause 1 or 2, wherein the pressing element is configured to extend from an initial position to an extended position.

[0087] Clause 4: An overload test system as described in any one of Clauses 1 to 3, wherein the pressing element comprises a hydraulic cylinder.

[0088] Clause 5: The overload test system as described in Clause 4, wherein the hydraulic cylinder extends from its lower end connected to the lower frame to its upper end connected to the upper frame.

[0089] Clause 6: The overload test system described in Clause 5, wherein when a predetermined pressure is applied to a hydraulic cylinder, the distance between the lower and upper ends increases.

[0090] Clause 7: An overload test system as described in any one of Clauses 4 to 6, wherein the pressing element is configured to be connected to a hydraulic source.

[0091] Clause 8: An upper bushing configured to fit into a passage in the upper frame and to receive a traction wire, and / or An overload test system according to any one of Clauses 1 to 7, further comprising a lower bushing configured to fit into a passage in the lower frame and to receive a traction wire.

[0092] Clause 9: The overload test system according to Clause 8, wherein the upper bushing and / or lower bushing comprises a first bushing component and a second bushing component for surrounding the traction wire.

[0093] Clause 10: The upper bushing is An insertion portion having an outer diameter smaller than the diameter of the passage in the upper frame, configured so that the insertion portion is inserted into the passage, An overload test system according to any one of clauses 8 to 9, comprising: a stopper portion having an outer diameter larger than the diameter of the passage of the upper frame to prevent insertion into the passage.

[0094] Clause 11: An overload test system according to any one of Clauses 8 to 10, wherein the upper bushing comprises an engaging portion for engaging with a wire clamp.

[0095] Clause 12: The lower bushing is An insertion portion having an outer diameter smaller than the diameter of the passage in the lower frame, configured so that the insertion portion is inserted into the passage, An overload test system according to any one of clauses 8 to 11, comprising: a stopper portion having an outer diameter larger than the diameter of the passage of the lower frame to prevent insertion into the passage.

[0096] Clause 13: An overload test system according to any one of Clauses 8 to 12, wherein the lower bushing comprises an engaging portion that engages with the traction system.

[0097] Clause 14: The lower frame is A base with a passageway, A first side wall extending vertically from the base, An overload test system according to any one of clauses 1 to 13, comprising a second side wall extending vertically from the base.

[0098] Clause 15: The upper frame is A base with a passageway, A first side wall extending vertically from the base, It comprises a second side wall extending vertically from the base, The overload test system according to Clause 14, wherein the first and second side walls extend toward the base of the lower frame.

[0099] Clause 16: The overload test system as described in Clause 15, wherein the pressing element is positioned between the side wall of the upper frame and the side wall of the lower frame.

[0100] Clause 17: An overload test system as described in any one of Clauses 15 to 16, wherein the side walls of the upper frame are positioned between the side walls of the lower frame.

[0101] Clause 18: An overload test system as described in any one of Clauses 15 to 17, wherein the side wall of the lower frame is provided with a slot.

[0102] Article 19: A first connecting assembly is rotatably connected to a first wall of the upper frame and slidably connected to a first wall of the lower frame via a slot, The overload test system according to Clause 18 further comprises a second connecting assembly rotatably connected to a second side wall of an upper frame and slidably connected to a second side wall of a lower frame via a slot.

[0103] Clause 20: A method for testing the overload mechanism of the traction system of a lifting device, wherein the lifting device is Cargo transport structure, Towing wire and A towing system positioned on a load-carrying structure to drive the load-carrying structure along a lift path by engaging with a towing wire, the towing system comprising an overload mechanism to prevent movement of the load-carrying structure when the load on the load-carrying structure exceeds a load threshold, The method is Position the lower frame of the overload test system so that it is mounted on the traction system, An upper frame of an overload test system, wherein the lower frame is slidably connected to the upper frame, and the upper frame is coupled to a traction wire, A method comprising applying a predetermined pressure to move the lower frame relative to the upper frame in order to increase the traction force exerted on the towing wire.

[0104] Clause 21: The method of Clause 20, wherein positioning the lower frame so as to be mounted on the traction system includes positioning the lower bushing so as to be mounted on the traction system and inserting the traction wire into the lower bushing.

[0105] Clause 22: The method according to Clause 21, wherein inserting the towing wire into the lower bushing includes placing the first bushing component and the second bushing component around the towing wire.

[0106] Clause 23: The method of any one of Clauses 21 to 22, wherein positioning the lower frame so as to be mounted on the traction system includes inserting the lower bushing into the passage of the lower frame.

[0107] Clause 24: The method of any one of Clauses 20 to 23, wherein connecting the upper frame to the traction wire includes placing the upper bushing above the upper frame and inserting the traction wire into the upper bushing.

[0108] Clause 25: The method of Clause 24, wherein inserting the towing wire into the upper bushing includes placing the first bushing component and the second bushing component around the towing wire.

[0109] Clause 26: The method of any one of Clauses 24 to 25, wherein connecting the upper frame to the traction wire includes inserting the upper bushing into the passage of the upper frame.

[0110] Clause 27: The method of any one of Clauses 24 to 26, wherein connecting the upper frame to the towing wire includes positioning the wire clamp so that it rests on the upper bushing and clamping the towing wire with the wire clamp to prevent it from moving upward on the upper frame.

[0111] Clause 28: The method according to any one of Clauses 20 to 27, wherein the pressing element is a hydraulic cylinder, and the method comprises connecting the hydraulic cylinder to a hydraulic source.

[0112] Clause 29: The method according to Clause 28, wherein applying a predetermined pressure involves activating a hydraulic source to provide a predetermined pressure to a hydraulic cylinder.

[0113] Clause 30: A method for setting a load threshold for an overload mechanism of a towing system of a lifting device, wherein the lifting device is Cargo transport structure, Towing wire and A towing system positioned on a load-carrying structure to drive the load-carrying structure along a lift path by engaging with a towing wire, the towing system comprising an overload mechanism to prevent movement of the load-carrying structure when the load on the load-carrying structure exceeds a load threshold, The method is The overload mechanism shall be tested in accordance with any of the clauses 20 to 29, A method comprising adjusting an overload mechanism to set a load threshold corresponding to a predetermined pressure applied to an overload test system.

[0114] While only a few examples are disclosed herein, other substitutions, modifications, uses, and / or equivalents are possible. Furthermore, all possible combinations of the examples described are also encompassed. Therefore, the scope of this disclosure should not be limited by any particular example, but should be determined solely by a fair reading of the following claims.

Claims

1. An overload test system for testing the overload mechanism of a lifting device's traction system, Lower frame and An upper frame configured to be coupled to a traction wire of the lifting device, wherein the upper frame is slidably connected to the lower frame, The system includes a pressing element positioned between the upper frame and the lower frame, which moves the lower frame relative to the upper frame, An overload testing system comprising a lower frame and an upper frame, each having a passage for receiving the traction wire.

2. To prevent the upper frame from moving upward, a wire clamp is further provided above the upper frame for clamping the towing wire. The aforementioned wire clamp is The first clamping component, The second clamping component, The overload testing system according to claim 1, comprising a connector that presses the first clamp component and the second clamp component against each other to clamp the traction wire between the first clamp component and the second clamp component.

3. The overload test system according to any one of claims 1 to 2, wherein the pressing element is configured to extend from an initial position to an extended position.

4. The overload test system according to any one of claims 1 to 3, wherein the pressing element comprises a hydraulic cylinder.

5. An upper bushing configured to fit into the passage of the upper frame and to receive the traction wire, and / or The overload test system according to any one of claims 1 to 4, further comprising a lower bushing configured to fit into the passage of the lower frame and to receive the traction wire.

6. The overload test system according to claim 5, wherein the upper bushing and / or the lower bushing comprises a first bushing component and a second bushing component for surrounding the traction wire.

7. A method for testing the overload mechanism of the traction system of a lifting device, The aforementioned lifting device is Cargo transport structure, Towing wire and A towing system positioned on the cargo transport structure to drive the cargo transport structure along a lift path by engaging with the towing wire, the towing system comprising an overload mechanism to prevent movement of the cargo transport structure when the load on the cargo transport structure exceeds a load threshold, The aforementioned method, Position the lower frame of the overload test system so that it is placed on the traction system, The upper frame of the overload test system, wherein the lower frame is slidably connected to the upper frame, and the upper frame is connected to the traction wire, A method comprising applying a predetermined pressure to move the lower frame relative to the upper frame in order to increase the traction force exerted on the traction wire.

8. Positioning the lower frame so that it is mounted on the traction system is The lower bushing is positioned so as to rest on the traction system, The method according to claim 7, further comprising inserting the traction wire into the lower bushing.

9. The method according to claim 8, wherein inserting the towing wire into the lower bushing includes placing the first bushing component and the second bushing component around the towing wire.

10. The method according to any one of claims 8 to 9, wherein positioning the lower frame so as to be placed on the traction system includes inserting the lower bushing into the passage of the lower frame.

11. Connecting the upper frame to the traction wire is The upper bushing is placed above the upper frame, The method according to any one of claims 7 to 10, comprising inserting the traction wire into the upper bushing.

12. The method according to claim 11, wherein inserting the towing wire into the upper bushing includes placing the first bushing component and the second bushing component around the towing wire.

13. The method according to any one of claims 11 to 12, wherein connecting the upper frame to the traction wire includes inserting the upper bushing into the passage of the upper frame.

14. Connecting the upper frame to the traction wire is The wire clamp is placed so as to rest on the upper bushing, The method according to claim 13, further comprising clamping the towing wire with the wire clamp to prevent the upper frame from moving upward.

15. A method for setting a load threshold for an overload mechanism of a towing system of a lifting device, The aforementioned lifting device is Cargo transport structure, Towing wire and A towing system positioned on the cargo transport structure to drive the cargo transport structure along a lift path by engaging with the towing wire, the towing system having an overload mechanism to prevent the cargo transport structure from moving when the load on the cargo transport structure is greater than a load threshold, The aforementioned method, The test is performed on the overload mechanism, wherein the test step is the method according to any one of claims 7 to 14. A method comprising adjusting the overload mechanism to set the load threshold corresponding to the predetermined pressure applied to the overload test system.

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