Lifting device

Abstract

Lift devices according to the present disclosure can include a base and a linkage arrangement including a first link and a second link connected to the base at first and second fixed coupling locations, respectively. The lift devices can also include a lifting mechanism coupled to the first and second links, where the lifting mechanism is movable between a stowed position and a deployed position. Further, the first and second links are configured to pivot relative to one another in opposite directions as the lifting mechanism moves between the stowed and deployed positions.

Description

Technical Field

[0001] This invention relates to lifting devices, such as aerial work platforms. Background Technology

[0002] Existing aerial work platforms include a base and a retractable lifting mechanism formed by a series of interconnected, foldable support members. The support members include a first pair of lower foldable support members and a second pair of lower foldable support members. The first pair of lower foldable support members is pivotally connected to the base at a fixed pivot point, and the second pair of lower foldable support members is slidably connected to the base using rollers. In another embodiment, both pairs of lower foldable support members are slidably connected to the base. With this configuration, the connection between the lifting mechanism and the base can be non-rigid.

[0003] Examples of existing aerial work platforms are disclosed in U.S. Patent Application Publication No. 2020 / 0399107A1. Other examples of lifting devices are disclosed in EP 0760 350A1, JP S62 147700U, GB 2 323 073 A, CN 207 030 833U, and US2 370 887A. Summary of the Invention

[0004] The lifting device according to this disclosure may include a base and a linkage arrangement including a first link and a second link connected to the base at a first fixed connection position and a second fixed connection position, respectively. The lifting device may further include a lifting mechanism coupled to the first link and the second link, wherein the lifting mechanism is movable between a retracted position and an extended position. Furthermore, the first link and the second link are configured to pivot relative to each other in opposite directions when the lifting mechanism moves between the retracted position and the extended position.

[0005] The scissor lift according to this disclosure may include: a base having a first pair of fixed hinged positions and a second pair of fixed hinged positions; and a linkage arrangement including a first pair of links and a second pair of links pivotally connected to the first pair of fixed hinged positions and the second pair of fixed hinged positions, respectively, and a coordinating mechanism configured to coordinate the movement of the first pair of links and the second pair of links. Furthermore, the scissor lift may include a retractable lifting mechanism having a plurality of foldable support members that cooperate with each other to allow the lifting mechanism to move between a retracted position and an extended position, wherein the foldable support members include a first pair of lowermost foldable support members and a second pair of lowermost foldable support members connected to the first pair of links and the second pair of links, respectively. A platform is coupled to the upper end of the lifting mechanism, and an actuator is coupled to at least one of the foldable support members for moving the lifting mechanism from the retracted position to the extended position. When the lifting mechanism moves from the retracted position to the extended position, the first pair of links is configured to pivot in a first direction, and the second pair of links is configured to pivot in a second direction opposite to the first direction. Furthermore, the position of the center plane of the lifting mechanism can remain essentially unchanged when the lifting mechanism moves between the retracted and extended positions.

[0006] Further according to this disclosure, a lifting device may include: a base having a first fixed connection position and a second fixed connection position; and a linkage arrangement including a first link and a second link connected to the base at the first and second fixed connection positions, respectively. The lifting device may also include a lifting mechanism coupled to the first and second links, wherein the lifting mechanism includes a plurality of foldable members and is movable between a retracted position and an extended position. Additionally, the lifting device may include a platform coupled to the upper end of the lifting mechanism. The first and second links of the linkage arrangement are configured to pivot relative to each other in opposite directions when the lifting mechanism moves between the retracted and extended positions. Furthermore, the linkage arrangement may be configured to cooperate with the lifting mechanism such that the position of the lifting mechanism across the central plane traversed between the first and second connection positions remains substantially unchanged when the lifting mechanism moves between the retracted and extended positions.

[0007] Furthermore, according to the present invention, a lifting device may include: a base; a lifting mechanism movable relative to the base between a retracted position and an extended position; a linkage arrangement including a first link and a second link; and a support assembly. Additionally, 1) the first link and the second link may be connected to the base at a first fixed connection position and a second fixed connection position and may be further connected to the lower end of the lifting mechanism, or 2) the first link and the second link may be connected to the support assembly at a first fixed connection position and a second fixed connection position and may be further connected to the upper end of the lifting mechanism. Furthermore, the first link and the second link are configured to pivot relative to each other in opposite directions when the lifting mechanism moves between the retracted and extended positions.

[0008] While exemplary embodiments have been shown and disclosed, such disclosure should not be construed as limiting the claims. It is anticipated that various modifications and alternative designs may be made without departing from the scope of this disclosure. Attached Figure Description

[0009] Figure 1 The present disclosure is a perspective view of a lifting device, which includes a base, a linkage arrangement connected to the base, a lifting mechanism connected to the linkage arrangement, and a support assembly or work platform assembly connected to the upper end of the lifting mechanism, wherein the lifting mechanism and the linkage arrangement are shown in a retracted position.

[0010] Figure 2 yes Figure 1 A perspective view of the lifting device, showing each of the lifting mechanism and linkage arrangement in the deployed position;

[0011] Figure 3 yes Figure 1 A side view of the lifting device, showing each of the lifting mechanism and linkage arrangement in the retracted position;

[0012] Figure 4 yes Figure 1 A side view of the lifting device, showing each of the lifting mechanism and linkage arrangement in the deployed position;

[0013] Figure 5 yes Figure 1 A partial exploded perspective view of the lifting device;

[0014] Figure 6 This is a perspective view of the base of the linkage arrangement and lifting device, showing the linkage arrangement in its retracted position;

[0015] Figure 7 It is a perspective view of the linkage arrangement and base of the lifting device, showing the linkage arrangement in its deployed position;

[0016] Figure 8 This is a side view of the linkage arrangement and a portion of the base, showing the linkage arrangement in a position between the retracted and extended positions;

[0017] Figure 9 It corresponds to Figure 8 A schematic diagram of the linkage arrangement;

[0018] Figure 10 Based on the schematic diagram of the linkage arrangement of this disclosure, a second embodiment of the timing mechanism of the linkage arrangement is shown;

[0019] Figure 11 Based on the schematic diagram of the linkage arrangement of this disclosure, a third embodiment of the timing mechanism of the linkage arrangement is shown;

[0020] Figure 12 Based on the schematic diagram of the linkage arrangement of this disclosure, a fourth embodiment of the timing mechanism of the linkage arrangement is shown;

[0021] Figure 13 Based on the schematic diagram of the linkage arrangement of this disclosure, a fifth embodiment of the timing mechanism of the linkage arrangement is shown;

[0022] Figure 14 Based on the schematic diagram of the linkage arrangement of this disclosure, a sixth embodiment of the timing mechanism of the linkage arrangement is shown;

[0023] Figure 15 This is a perspective view of yet another embodiment of the linkage arrangement according to this disclosure;

[0024] Figure 16 This is a partial perspective view of another lifting device according to the present disclosure, which includes a linkage arrangement connecting a lifting mechanism to a support assembly or a work platform assembly, wherein both the lifting mechanism and the linkage arrangement are shown in a retracted position; and

[0025] Figure 17 It is based on Figure 16 A partial perspective view of the lifting device, showing each of the lifting mechanism and linkage arrangement in the deployed position. Detailed Implementation

[0026] Detailed embodiments are disclosed herein as needed; however, it should be understood that the disclosed embodiments are merely exemplary and various alternative forms may be adopted. The accompanying drawings are not necessarily drawn to scale; some features may be enlarged or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but only as a representative basis for teaching those skilled in the art.

[0027] Figures 1 to 4A lifting device 10, such as an aerial work platform, is shown according to the present disclosure. In the illustrated embodiment, the lifting device 10 is formed as a scissor lift having a base 12, a linkage arrangement 14 connected to the base 12, a retractable lifting assembly or mechanism 16 connected to the linkage arrangement 14, and a support assembly (such as a work platform assembly 18) connected to the lifting mechanism 16. As will be explained in more detail below, the lifting mechanism 16 is capable of […]. Figure 1 and Figure 3 The retracted or collapsed position shown in the image is consistent with... Figure 2 and Figure 4 The work platform assembly 18 can be moved between the extended positions, as well as to various positions between the retracted and extended positions, to move the work platform assembly 18 to any of a plurality of desired use positions. Furthermore, the linkage arrangement 14 and the lifting mechanism 16 are configured to cooperate to control or otherwise influence the movement of the work platform assembly 18 when the lifting mechanism 16 moves between the retracted and extended positions.

[0028] For example, the lifting device 10 can be configured as a mobile vehicle. In this respect, the base 12 can be a vehicle body, frame, or chassis, and the lifting device 10 can be provided with one or more wheels 20, or other movement-promoting components, such as tracks, movably coupled to the base 12. One or more of the wheels 20 (e.g., front wheels) or other movement-promoting components can be driven by any suitable drive system 22 (such as an internal combustion engine, one or more electric motors, etc.) and guided by a steering system 24, allowing the lifting device 10 to be positioned at a desired location. Although the drive system 22 is... Figure 1 and Figure 3 The drive system 22 is schematically shown as a single unit, but it may include any suitable number of units (e.g., an engine or motor). For example, the drive system 22 may include a separate electric motor for each front wheel 20, or it may include a separate electric motor for each front wheel 20 and each rear wheel 20.

[0029] In another embodiment, the lifting device 10 can be a stationary device. In this case, the base 12 can be constructed, for example, as a stationary support structure.

[0030] Reference Figure 5 The base 12 also includes two or more connection or hinge positions 26 for connection with the linkage arrangement 14. Figure 5In the illustrated embodiment, the base 12 includes a first pair and a second pair (e.g., a front pair and a rear pair) of fixed hinge positions 26a and 26b, which define fixed pivot points for connection with the linkage arrangement 14. For example, the hinge positions 26 may be formed in the body portion of the base 12 or in a support member (such as a bracket) attached to the body portion. Furthermore, the body portion and / or support member may be made of any suitable material, such as metal and / or composite materials.

[0031] The linkage arrangement 14 includes two or more links 28, each link having a first portion or end connected to a hinged position 26 on the base 12, and a second portion or end connected to the lifting mechanism 16. Figures 1 to 5 In the illustrated embodiment, the linkage arrangement 14 includes a first pair and a second pair (e.g., a front pair and a rear pair) of links 28a and 28b, respectively, which are pivotally connected to the first and second pairs of fixed hinged positions 26a and 26b in any suitable manner (such as by means of pivot pins or other connecting members). Furthermore, when the lifting mechanism 16 moves between the retracted position and the extended position, the linkage arrangement 14 is capable of relative to the base 12... Figure 6 The collapsible position shown and Figure 7 Move between the shown unfolded positions.

[0032] The linkage arrangement 14 may also include a coordination mechanism or timing mechanism 30 associated with the links 28a, 28b of the linkage arrangement 14, and the coordination mechanism or timing mechanism is configured to coordinate (e.g., synchronize) the movement of the links 28a, 28b. While the timing mechanism 30 can have any suitable configuration, Figures 5 to 7 In the illustrated embodiment, the timing mechanism 30 includes a pair of timing links 32 respectively connected to a first pair of links 28a and a second pair of links 28b. Specifically, each timing link 32 has a first end 33 connected to at least one link in the first pair of links 28a and a second end 34 connected to at least one link in the second pair of links 28b. In the illustrated embodiment, the first pair of links 28a are fixedly connected together by a lateral extension member 36 (e.g., a rod, bar, etc.), and the first end 33 of each timing link 32 is pivotally connected to a corresponding downwardly extending link 38, which is fixedly connected to the lateral extension member 36. For example, the first end 32 of each timing link 32 may be pivotally connected to the corresponding link 38 by a pivot pin or other connecting member. Furthermore, the second end 34 of each timing link 32 may be directly pivotally connected to a corresponding link in the second pair of links 28b, such as by a pivot pin or other connecting member.

[0033] Reference Figures 1 to 4The lifting mechanism 16 is coupled to the linkage arrangement 14, enabling the lifting mechanism 16 to move together with the linkage arrangement 14. In the illustrated embodiment, the lifting mechanism 16 is a scissor lift structure formed by a series of connected, foldable support members 40 (such as rigid elements like rods, bars, etc.), which cooperate with each other to allow the lifting mechanism 16 to move between a retracted position and an extended position. Furthermore, in the illustrated embodiment, the lifting mechanism 16 includes two sets or two groups of such support members 40, one set on each side of the lifting device 10. Each set of support members 40 can be connected together using any suitable connecting member (such as a central or intermediate pivot pin 42 and an outer pivot pin 44). The central pivot pin 42 and the outer pivot pin 44 extend through adjacent support members 40 to pivotally connect the support members 40. The two sets of support members 40 can also be connected together using any suitable connecting member (such as laterally extending rods, bars, or struts). Support members 40 may include two or more support members 40 connected to the linkage arrangement 14 and two or more support members 40 connected to the work platform assembly 18. In the illustrated embodiment, support members 40 include lowermost support members 40a of a first pair and a second pair (e.g., a front pair and a rear pair) pivotally connected to the first pair of links 28a and the second pair of links 28b of the linkage arrangement 14 by pivot pins or other connecting members, and uppermost support members 40b of a first pair and a second pair (e.g., a front pair and a rear pair) pivotally connected to the work platform assembly 18.

[0034] The lifting device 10 also includes one or more actuators (such as hydraulic cylinders, pneumatic cylinders, electric linear actuators, etc.) associated with the lifting mechanism 16 and configured to move the lifting mechanism 16 from a retracted position to an extended position or between a retracted position and an extended position. In the illustrated embodiment, the lifting device 10 includes actuators 46 mounted to different support members 40 or different pairs of support members 40. Specifically, the actuators 46 have: a first end connected between a pair (e.g., a second pair) of lowermost support members 40a (e.g., connected to a lateral extension member (such as a rod, bar, or strut) connected to the pair of lowermost support members 40a); and a second end connected between a pair (e.g., a first pair) of uppermost support members 40b (e.g., connected to a lateral extension member (such as a rod, bar, or strut) connected to the pair of uppermost support members 40b). Furthermore, the actuators 46 are movable between a retracted position and an extended position to move the lifting mechanism 16 from a retracted position to an extended position.

[0035] In another embodiment, the lifting device 10 may include one or more actuators connected between the base 12 and one or more support members in the support member 40. In yet another embodiment, the lifting device 10 may include one or more actuators connected between the linkage arrangement 14 and one or more support members in the support member 40. In yet another embodiment, the lifting device 10 may include any combination of the above-described actuators. For example, the lifting device 10 may include one or more actuators connected between the base 12 and one or more support members in the support member 40, one or more actuators connected between the linkage arrangement 14 and one or more support members in the support member 40, and / or one or more actuators mounted to different support members 40. In any case, one or more actuators for moving the lifting mechanism 16 may be considered part of the lifting mechanism 16.

[0036] The work platform assembly 18 is coupled to the lifting mechanism 16 and includes support members (such as a base or work platform 48) and a control system 50 associated with the platform 48 to control the operation of the lifting device 10 (e.g., operation of the drive system 22, operation of the steering system 24, movement of the platform 48 via the linkage arrangement 14 and the lifting mechanism 16, and / or movement of the platform 48 relative to the lifting mechanism 16). Although the work platform assembly 18 can be coupled to the lifting mechanism 16 in any suitable manner, in the illustrated embodiment, the platform 48 has first and second pairs (e.g., front and rear pairs) slidable connection positions (e.g., slide rails) connected to the first and second pairs (e.g., front and rear pairs) of uppermost support members 40b. Each slidable connection position can receive a roller or other slidable element connected to the corresponding uppermost support member 40b. Support elements 52 (e.g., links) are also pivotally connected to the central portion of the platform 48 and connected to lateral extension members extending between the pair of uppermost support members 40b. In another embodiment, platform 48 may have a pair of fixed or hinged positions pivotally connected to a pair (e.g., the front pair) of uppermost support members 40b and a pair of slidable connection positions (e.g., rails) connected to another pair (e.g., the rear pair) of uppermost support members 40b.

[0037] The platform 48 of the work platform assembly 18 is sized to accommodate an operator thereon. A railing assembly or frame assembly 54 is disposed on the platform 48, and the frame assembly 54 includes one or more protective members or railings (e.g., toe plate, intermediate railing, and top railing) that cooperate to accommodate the operator within the frame assembly 54. The frame assembly 54 may also include a movable (e.g., pivotable) door 58 to allow the operator to enter and exit the work platform assembly 18.

[0038] The control system 50 may include any suitable controls for controlling the operation of the lifting device 10. For example, the control system 50 may include a control unit 60 (e.g., an electronic control unit, control box, or control panel) mounted on or supported by the platform 48 and having one or more controls for inputting control commands, such as buttons, switches, wheels, levers (e.g., joysticks), etc. The control system 50 may also include one or more other control units located at other locations on the lifting device 10. Furthermore, the control system 50 may include any suitable hardware and / or software for controlling the operation of any of the aforementioned systems, mechanisms, arrangements, or other components. For example, the control system 50 may include one or more processors communicating with or configured to communicate with one or more storage devices or memory units, which include computer-readable program instructions executable by the one or more processors, enabling the control system 50 to control the operation of the lifting mechanism 16, drive system 22, steering system 24, etc. The control system 50 may also, or alternatively, include one or more application-specific integrated circuits, programmable gate arrays, programmable logic devices, and / or digital signal processors.

[0039] Reference Figures 1 to 7 The operation of the lifting device 10 will now be described in more detail. When the lifting device 10 is in the desired position and is properly supported or otherwise supported, the operator can enter the work platform assembly 18 through the door 58. The operator can then use the controls of the control unit 60 to move the work platform assembly 18. For example, the control unit 60 can be used to control the operation of the actuator 46 so that the lifting mechanism 16 can be raised from the retracted position to the extended position.

[0040] As described above, the linkage arrangement 14 and the lifting mechanism 16 are configured to cooperate together when the lifting mechanism 16 moves between the retracted position and the extended position. (Refer to...) Figure 4For example, the linkage arrangement 14 can be configured to cooperate with the lifting mechanism 16 such that when the lifting mechanism 16 moves between the retracted position and the extended position, the position of the central plane P of the lifting mechanism 16 (which passes between the first pair of hinge positions 26a and the second pair of hinge positions 26b of the base 12, and passes through one or more center points of the lifting mechanism 16 when viewed from one side of the lifting mechanism 16) relative to the base 12 remains substantially unchanged. In this respect, for example, the linkage arrangement 14 and the lifting mechanism 16 can cooperate such that when the lifting mechanism 16 moves from the retracted position to the extended position (or any position between the retracted and extended positions, such as the intermediate position), the central plane P tilts from the bottom or lower end of the lifting mechanism 16 to the top or upper end of the lifting mechanism 16 by less than + / -5°, or less than + / -3°, or less than + / -1°, or less than + / -0.5°, and / or when the lifting mechanism 16 moves from the retracted position to the extended position, the position of a portion of the central plane P (e.g., a point or line on the central plane P corresponding to the lower end of the lifting mechanism 16) moves by less than + / -4 inches (+ / -10.16 cm), or less than + / -2 inches (+ / -5.08 cm), or less than + / -1 inch (+ / -2.54 cm), or less than + / -0.5 inches (+ / -1.27 cm).

[0041] Reference Figure 6 and 7 When the lifting mechanism 16 moves between the retracted and extended positions, the first pair of links 28a and the second pair of links 28b of the linkage arrangement 14 pivot in opposite directions. Furthermore, the timing mechanism 30 of the linkage arrangement 14 is configured to coordinate the movement of links 28a and 28b when the lifting mechanism 16 moves between the retracted and extended positions. In this regard, the timing link 32 of the timing mechanism 30 can coordinate or control the movement of links 28a and 28b such that the first pair of links 28a and the second pair of links 28b pivot substantially synchronously (e.g., at substantially the same speed). For example, the pivoting speed of the first pair of links 28a can be within + / - 10%, + / - 5%, + / - 2%, or + / - 0.5% of the pivoting speed of the second pair of links 28b.

[0042] Reference Figure 8 and Figure 9Further details regarding the linkage arrangement 14 and the associated timing mechanism 30 will now be discussed. For each timing link 32, a first end 33 and a second end 34 define a corresponding first connection position 63 and a second connection position 64, respectively. One of the first connection position 63 and the second connection position 64 is positioned below a plane 66 extending through the fixed hinge positions 26a, 26b of the base 12, and the other of the first connection position 63 and the second connection position 64 is positioned above the plane 66. Furthermore, when the linkage arrangement 14 moves between its retracted and extended positions (i.e., when the lifting mechanism 16 moves between its retracted and extended positions), the connection positions 63, 64 can be maintained on opposite sides of the plane 66.

[0043] Reference Figure 9 The corresponding first fixed hinge position 26a and second fixed hinge position 26b of the base 12 respectively define a first pivot axis 68a and a second pivot axis 68b that are parallel to each other and spaced apart from each other (see also...). Figure 5 For each timing link 32, when the lifting device 10 is viewed in a direction parallel to the first pivot axis 68a and the second pivot axis 68b respectively (e.g., viewed from one side of the lifting device 10), the first distance D1 between the first fixed connection position 26a and the first connection position 63 can be substantially equal to the second distance D2 between the second fixed connection position 26b and the second connection position 64. For example, distances D1 and D2 can be equal, or the first distance D1 can be within + / -10%, + / -5%, + / -2%, or + / -0.5% of the second distance D2.

[0044] Furthermore, the links 28 of the linkage arrangement 14 can be symmetrical. More specifically, links 28a can be symmetrical with respect to links 28b (for example, each link 28a can have a length from its corresponding connection position 26a to its connection position with its corresponding support member 40a, which is substantially equal to the length of each link 28b from its corresponding connection position 26b to its connection position with its corresponding support member 40a). With this configuration, the timing link 32 described above can effectively coordinate the movement of links 28 when the lifting mechanism 16 moves between the retracted position and the extended position.

[0045] Compared to existing lifting devices, the lifting device 10 according to this disclosure offers numerous advantages. For example, because the linkage arrangement 14 is connected to the base 12 at a fixed hinge position 26, the linkage arrangement 14 can provide a more rigid connection between the lifting mechanism 16 and the base 12. As a result, the stability (e.g., lateral stability) and operational feel of the lifting device 10 can be improved. Furthermore, the timing mechanism 30 of the linkage arrangement 14 can coordinate the movement of the linkage 28, such that the position of the center plane P of the lifting mechanism 16 relative to the base 12 remains substantially unchanged when the lifting mechanism 16 moves between the retracted and extended positions. Additionally, because the lifting device 10 can be configured at the base 12 without any sliding channels, the repair and maintenance of conventional sliding components such as rollers and pads can be eliminated, and more design freedom regarding the base construction can be provided. Furthermore, the linkage arrangement 14 can add additional lifting height to the lifting mechanism 16, which can allow for a reduction in the number and / or size of foldable components in the lifting mechanism 16 to achieve the desired lifting height.

[0046] As described above, the timing mechanism 30 can have any suitable configuration for coordinating the movement of the link 28 of the link arrangement 14. Figures 10 to 14 Schematic diagrams of other exemplary timing mechanism embodiments are shown. Furthermore, these figures illustrate a single first link 28a' and a single second link 28b' of the link arrangement 14', and links 28a' and 28b' may be symmetrical (e.g., links 28a' and 28b' may have the same length but are mirror images). It should be understood that the aforementioned timing mechanism 30 and any of the following embodiments can be used with any suitable link arrangement according to this disclosure having one or more first links and one or more second links. For example, any of the following embodiments can be used with a link arrangement having a pair of first links and a pair of second links, such that the same or similar base and lifting mechanism configurations described above can be used with the following embodiments. In the case of a single first link and a single second link, the base and lifting mechanism configuration can be modified or adjusted as needed to accommodate the interaction with the first and second links. For example, the base may be provided with a first fixed hinge position and a second fixed hinge position (e.g., a front fixed hinge position and a rear fixed hinge position) that can be respectively connected to the first link and the second link, and the lifting mechanism may be provided with a first lower support member and a second lower support member (e.g., a front support member and a rear support member) that can also be connected to the first link and the second link.

[0047] exist Figure 10In the illustrated timing mechanism embodiment, the timing mechanism 130 includes an actuator 132, such as a hydraulic cylinder, a pneumatic cylinder, an electric linear actuator, etc., having a first end 134 connected (e.g., pivotally connected) to a first link 28a' and a second end 136 connected (e.g., pivotally connected) to a second link 28b'. In this embodiment, a suitable control system (e.g., the control system 50 described above) can be used to control the actuator 132 and the actuators (e.g., actuator 40) of the corresponding lifting mechanism (e.g., lifting mechanism 16) such that the movement of the actuators can be coordinated (e.g., synchronized). For example, the control system can control the extension speed and retraction speed of the actuator 132 such that these speeds correspond to the extension speed and retraction speed of the actuator of the lifting mechanism, respectively. Furthermore, in the illustrated embodiment, the first link member or arm A′ (which may be, for example, part of the first link 28a′, or another link fixedly connected to the first link 28a′) and the second link member or arm B′ (which may be, for example, part of the second link 28b′, or another link fixedly connected to the second link 28b′) have the same length. In another embodiment, the first arm A′ and the second arm B′ may have different lengths, and the size and / or operating speed of the actuator 132 may be adjusted such that the movement of links 28a′, 28b′ is coordinated (e.g., synchronized) and correlated with the movement of the corresponding lifting mechanism.

[0048] exist Figure 11 In the illustrated timing mechanism embodiment, timing mechanism 230 includes a first actuator 232 connected to a first link 28a′ and a second actuator 234 connected to a second link 28b′. The opposite ends of actuators 232 and 234 may also be connected to base 12′. Each of these actuators 232 and 234 can also be any suitable actuator, such as a hydraulic cylinder, pneumatic cylinder, electric linear actuator, etc. In the illustrated embodiment, the first arm A′ and the second arm B′ have the same length, and the first actuator 232 and the second actuator 234 also have the same length. Furthermore, actuators 232 and 234 can be controlled such that they rotate the first link 28a′ and the second link 28b′ at substantially the same speed but in opposite directions. For example, actuators 232 and 234 can be controlled by a hydraulic circuit or by a control system (such as the control system 50 described above). In another embodiment, arms A′ and B′ may have different lengths, and the operation of actuators 232 and 234 may be adjusted accordingly to coordinate (e.g., synchronize) the rotation of links 28a′ and 28b′ (e.g., such that links 28a′ and 28b′ rotate at substantially the same speed but in opposite directions).

[0049] In other embodiments, the timing mechanism may include a first timing link and a second timing link, wherein the first timing link has a first end connected to a first link 28a' and a second end movably associated with a base 12', and the second timing link has a first end connected to a second link 28b' and a second end movably associated with a base 12'. Figure 12 In the illustrated embodiment, for example, the timing mechanism 330 includes two timing links, such as a first timing link 332 and a second timing link 334, each having a first end and a second end. In the illustrated embodiment, the first arm A′ and the second arm B′ have the same length, and the first timing link 332 and the second timing link 334 also have the same length. The timing mechanism 330 also includes a first gear 336 and a second gear 338, which are respectively engageable with each other and rotatably connected to the base 12′ (e.g., symmetrically positioned relative to fixed hinge positions 26a′, 26b′ on the base 12′). The second end of the first timing link 332 is connected (e.g., pivotally connected) to the first gear 336, and the second end of the second timing link 334 is connected (e.g., pivotally connected) to the second gear 336. When the associated lifting mechanism (e.g., lifting mechanism 16) moves between the retracted and extended positions, this movement also causes links 28a' and 28b' to move, which in turn causes timing links 332 and 334 to move and thereby rotate gears 336 and 338. The interaction of gears 336 and 338 results in controlled, coordinated (e.g., synchronized) movement of links 28a' and 28b'.

[0050] exist Figure 13In the illustrated embodiment, the timing mechanism 430 further includes two timing links as described above, such as a first timing link 432 and a second timing link 434, each having a first end and a second end. The timing mechanism 430 also includes a movable guide member 436 mounted on the base 12', such that the guide member 436 is movable relative to the base 12 in both upward and downward directions. In the illustrated embodiment, the guide member 436 includes a lateral extension link 438 connected to a vertical extension member 440 (e.g., a rod or bar), which is received in or otherwise cooperates with a guide element 442 (such as a guide channel formed in or attached to the base 12'). The second end of the first timing link 432 is connected to a first portion of the guide member 436 (e.g., the first end of the lateral extension link 438), and the second end of the second timing link 434 is connected to a second portion of the guide member 436 (e.g., the second end of the lateral extension link 438). When the associated lifting mechanism (e.g., lifting mechanism 16) moves between a retracted position and an extended position, the movement of links 28a', 28b' is coordinated or controlled by the constrained movement of guide member 436 relative to guide element 442. In another embodiment, guide member 436 may have multiple parts movably connected together, and each part may be received in or otherwise cooperate with the guide element (such as a guide channel formed in or attached to base 12').

[0051] exist Figure 14 In the illustrated embodiment, the timing mechanism 530 further includes two timing links as described above, such as a first timing link 532 and a second timing link 534, each having a first end and a second end. The timing mechanism 530 also includes a rotatable member 536 (such as a pivot arm) rotatably mounted on the base 12' at a hinged position defining a pivot axis 537, and the rotatable member 536 having a first portion or segment 538 and a second portion or segment 540 extending in opposite directions away from the pivot axis 537. The second end of the first timing link 532 is pivotally connected to the first segment 538 of the rotatable member 536 (e.g., the first end of the rotatable member 536), and the second end of the second timing link 534 is pivotally connected to the second segment 540 of the rotatable member 536 (e.g., the second end of the rotatable member 536). In the illustrated embodiment, timing links 532 and 534 have the same length, and segments 538 and 540 of the rotatable member 536 have the same length. However, in another embodiment, timing links 532 and 534 may have different lengths, and segments 538 and 540 of the rotatable member 536 may also have different lengths.

[0052] As described above, any timing mechanism implementation disclosed can be used with any suitable linkage arrangement according to this disclosure having one or more first links and one or more second links. For example, if Figures 10 to 14 Any of the embodiments shown can be used with a linkage arrangement having a pair of first links and a pair of second links. The corresponding timing mechanism can also be configured as a pair of timing mechanisms, such that one timing mechanism in the pair can be connected to one of the first links and one of the second links, and the other timing mechanism can be connected to the other first link and the other second link. As another example, the pair of first links can be (e.g., by a lateral extension member) fixedly joined together, and the pair of second links can also be (e.g., by a lateral extension member) fixedly joined together, such that a single timing mechanism can be connected between the pair of first links and the pair of second links.

[0053] As a more detailed example, Figure 15 A link arrangement 14″ is shown, having a first pair and a second pair (e.g., a front pair and a rear pair) of links 28a″ and 28b″ respectively. The first pair of links 28a″ is fixedly connected together by a first lateral extension member 610 (e.g., a rigid rod, bar, etc.), and the second pair of links 28b″ is fixedly connected together by a second lateral extension member 612 (e.g., a rigid rod, bar, etc.). Furthermore, the first pair of links 28a″ and the second pair of links 28b″ are pivotally connected to a first pair of fixed hinge positions 26a″ and a second pair of fixed hinge positions 26b″ respectively formed on a base 12″. Additionally, the linkage arrangement 14″ includes a timing mechanism 30″ having a single timing link 32″ connected between a first pair of links 28a″ and a second pair of links 28b″. In the illustrated embodiment, a first end of the timing link 32″ is pivotally connected to a downwardly extending first connecting member 614 (e.g., a rod, bracket, etc.), which is fixedly connected to a first lateral extension member 610, and a second end of the timing link 32″ is pivotally connected to a second connecting member 616 (e.g., a rod, bracket, etc.), which is fixedly connected to a second lateral extension member 612. With this configuration, a single timing link 32″ can coordinate the movement of the two pairs of links 28a″, 28b″.

[0054] It should be noted that any of the aforementioned components can be made of any suitable material and in any suitable manner. For example, any component of any of the aforementioned linkage arrangements can be made of metals and / or composite materials, such as steel, ductile iron, aluminum, carbon fiber, glass fiber plastic, etc. As a more detailed example, the linkage members of the linkage arrangement can be made of stamped metal, steel tubing, or cast steel.

[0055] It should also be noted that any of the above-described linkage arrangements can be used to connect the lifting mechanism (e.g., lifting mechanism 16) and the support assembly (e.g., work platform assembly 18) of a lifting device (e.g., lifting device 10). For example, any of the above-described linkage arrangements can be flipped and connected between the lifting mechanism and the support assembly or work platform assembly. Depending on the construction of the lifting mechanism (e.g., whether the lifting mechanism includes one or two sets or two sets of foldable members), the support member (such as the platform of the support assembly) can be provided with two or more fixed connection or hinged positions, and the linkage arrangement can similarly be provided with two or more links for connection to the hinged positions.

[0056] As a more detailed example, Figure 16 and Figure 17 The lifting device 10″′ according to the present disclosure is shown, which includes a linkage arrangement 14″′ connecting the lifting mechanism 16″′ to a support assembly or a work platform assembly 18″′. The lifting mechanism 16″′ includes two sets or two sets of foldable support members 40″′, wherein each side of the lifting device 10″′ has one set of foldable support members, and the work platform assembly 18″′ includes a support member or platform 48″′, which is provided with a first pair and a second pair (e.g., a front pair and a rear pair) of fixed hinge positions 26a″′ and 26b″′ that define fixed pivot points, and the linkage arrangement 14″′ is similarly provided with a first pair and a second pair (e.g., a front pair and a rear pair) of links 28a″′ and 28b″′ connecting the fixed hinge positions 26a″′, 26b″′ and the uppermost support member 40b″′ of the lifting mechanism 16″′. Specifically, the first pair of links 28a″′ and the second pair of links 28b″′ are pivotally connected (e.g., using pivot pins or other connecting members) to corresponding first pair of fixed hinge positions 26a″′ and second pair of fixed hinge positions 26b″′ of the platform 48″′. These hinge positions 26a″′, 26b″′ may be formed in the body portion of the platform 48″′ or in a supporting member, such as a bracket attached to the body portion. Furthermore, the first pair of links 28a″′ and the second pair of links 28b″′ of the linkage arrangement 14″′ are pivotally connected (e.g., using pivot pins or other connecting members) to the first and second pairs (e.g., a front pair and a rear pair) of the uppermost supporting member 40b″′ of the lifting mechanism 16″′. Additionally, the linkage arrangement 14″′ may include a coordination mechanism or a timing mechanism for when the linkage arrangement 14″′ and the lifting mechanism 16″′ are respectively in... Figure 16 The collapsible position shown and Figure 17When moving between the shown deployment positions, the movement of links 28a″′ and 28b″′ of the linkage arrangement 14″′ is coordinated (e.g., synchronized). In the illustrated embodiment, the linkage arrangement 14″′ includes a coordination mechanism or timing mechanism 30″′ similar to the timing mechanism 30 described in detail above, and the coordination mechanism or timing mechanism 30″′ operates in a similar manner to the timing mechanism 30, so that further description of the timing mechanism 30″′ is unnecessary.

[0057] In other embodiments, the linkage arrangement 14″' of the lifting device 10″' may include any suitable coordinating or timing mechanism, such as those described above and / or Figures 10 to 15 Any timing mechanism implementation shown. It should be noted that in the case where the above timing mechanism implementation includes one or more components connected to a base (such as base 12') (e.g., Figures 11 to 14 In the embodiment shown, when the timing mechanism is used in conjunction with the lifting device 10″′, these components may alternatively be connected to the work platform assembly 18″′ (e.g., platform 48″′).

[0058] The lifting device 10″′ may further include a base (not shown) that is the same as or similar to the base 12, base 12′ or base 12″ described above, and a linkage arrangement that is the same as or similar to the linkage arrangement 14, linkage arrangement 14′ or linkage arrangement 14″ described above, for connecting the base to the lower end of the lifting mechanism 16″′ in the same or similar manner as described in the above description. Alternatively, the lifting device 10″′ may include a base that is connected to the lower end of the lifting mechanism 16″′ in any suitable manner.

[0059] Therefore, the lifting device according to the present invention may include a linkage arrangement according to the present disclosure for connecting a base to a lifting mechanism, or for connecting the lifting mechanism to a support assembly, such as a work platform assembly. Furthermore, the lifting device according to the present invention may include a first linkage arrangement according to the present disclosure for connecting a base to a lifting mechanism, and a second linkage arrangement according to the present disclosure for connecting the lifting mechanism to a support assembly (such as a work platform assembly).

[0060] The following paragraphs provide aspects of some implementations according to this disclosure.

[0061] The lifting device according to this disclosure may include a base, a lifting mechanism movable relative to the base between a retracted position and an extended position, a linkage arrangement including a first link and a second link, and a support assembly. Furthermore, 1) the first link and the second link may be connected to the base at a first fixed connection position and a second fixed connection position and may be further connected to the lower end of the lifting mechanism, or 2) the first link and the second link may be connected to the support assembly at a first fixed connection position and a second fixed connection position and may be further connected to the upper end of the lifting mechanism. Additionally, the first link and the second link are configured to pivot relative to each other in opposite directions when the lifting mechanism moves between the retracted position and the extended position.

[0062] According to the lifting device described in paragraph

[0061] , the first link and the second link are connected to the support assembly at the first fixed connection position and the second fixed connection position, and are also connected to the upper end of the lifting mechanism.

[0063] According to the lifting device described in paragraph

[0062] , the linkage arrangement includes a timing link connected to the first link and the second link.

[0064] According to the lifting device described in paragraph

[0062] , the linkage arrangement includes an actuator having a first end connected to a first link and a second end connected to a second link.

[0065] According to the lifting device described in paragraph

[0062] , the linkage arrangement includes a first actuator pivotally connected to a first linkage and a second actuator pivotally connected to a second linkage.

[0066] According to the lifting device described in paragraph

[0062] , the linkage arrangement includes a first gear and a second gear rotatably mounted on a support assembly, as well as a first timing link and a second timing link, wherein the first timing link has a first end connected to the first link and a second end connected to the first gear, and the second timing link has a first end connected to the second link and a second end connected to the second gear.

[0067] According to the lifting device described in paragraph

[0062] , the linkage arrangement includes a first timing link and a second timing link, and a movable guide member mounted on a support assembly, such that the guide member can move along a plane located between a first fixed connection position and a second fixed connection position, wherein the first timing link has a first end connected to the first link and a second end connected to the movable guide member, and the second timing link has a first end connected to the second link and a second end connected to the movable guide member.

[0068] According to the lifting device described in paragraph

[0062] , the linkage arrangement includes a first timing link and a second timing link and a pivot arm pivotally mounted on a support assembly, wherein the first timing link has a first end connected to the first link and a second end connected to the pivot arm, and the second timing link has a first end connected to the second link and a second end connected to the pivot arm.

[0069] While exemplary embodiments have been described above, these embodiments are not intended to describe all possible forms according to this disclosure. In this regard, the terms used in the specification are descriptive rather than restrictive, and it should be understood that various changes may be made without departing from the spirit and scope of this disclosure. Furthermore, features of various embodiments may be combined to form other embodiments according to this disclosure.

Claims

1. A lifting device, the lifting device comprising: Base; A linkage arrangement comprising: a first link and a second link, the first link and the second link being spaced apart from each other and pivotally connected to the base at a first fixed connection position and a second fixed connection position, respectively; and a timing mechanism associated with and configured to coordinate movement of the first link and the second link such that the first link and the second link can pivot substantially synchronously, wherein the timing mechanism defines a connection position relative to one of the first link and the second link, the connection position being located below a plane extending through the first fixed connection position and the second fixed connection position; and A lifting mechanism, comprising a first support member and a second support member, wherein the first support member and the second support member are pivotally connected together by a central pivot pin and are respectively pivotally connected to a first link and a second link, wherein the lifting mechanism is movable between a retracted position and an extended position; The first link and the second link are configured such that when the lifting mechanism moves between the retracted position and the extended position, they pivot about a first pivot axis and a second pivot axis respectively and in opposite directions relative to each other, and do not overlap when viewed in a direction parallel to the first pivot axis and the second pivot axis.

2. The lifting device of claim 1, further comprising an actuator associated with the lifting mechanism and configured to move the lifting mechanism from the retracted position to the extended position, wherein the actuator is separate from the timing mechanism.

3. The lifting device according to claim 2, wherein the timing mechanism includes a timing link connected to the first link and the second link.

4. The lifting device according to claim 3, wherein the timing link has a first end and a second end that respectively define a first connection position and a second connection position, and wherein one of the first connection position and the second connection position is located below a plane extending through the first fixed connection position and the second fixed connection position, and the other of the first connection position and the second connection position is located above the plane.

5. The lifting device according to claim 4, wherein the first fixed connection position and the second fixed connection position respectively define the first pivot axis and the second pivot axis, and wherein when the lifting device is viewed in a direction parallel to the first pivot axis and the second pivot axis, a first distance between the first fixed connection position and the first connection position is substantially equal to a second distance between the second fixed connection position and the second connection position.

6. The lifting device according to claim 1, wherein the linkage arrangement further includes: An additional first link is pivotally connected to the base at an additional first connection position; a lateral extension member is fixedly connected to the first link and the additional first link; and a downwardly extending link is fixedly connected to the lateral extension member, wherein the timing mechanism includes a timing link having a first end pivotally connected to the downwardly extending link and a second end connected to the second link.

7. The lifting device according to claim 1, wherein the timing mechanism includes an actuator connected to the first link and the second link.

8. The lifting device according to claim 1, wherein the timing mechanism comprises a first actuator connected to the first link and a second actuator connected to the second link.

9. The lifting device according to claim 1, wherein the timing mechanism includes a first timing link and a second timing link, the first timing link having a first end connected to the first link and a second end movably associated with the base, and the second timing link having a first end connected to the second link and a second end movably associated with the base.

10. The lifting device according to claim 9, wherein the timing mechanism further comprises a first gear and a second gear, the first gear and the second gear being capable of engaging with each other and rotatably connected to the base, wherein the second end of the first timing link is connected to the first gear, and the second end of the second timing link is connected to the second gear.

11. The lifting device of claim 9, wherein the timing mechanism further comprises a movable guide member mounted on the base such that the guide member is movable relative to the base in an upward and downward direction, and wherein the second end of the first timing link is connected to the guide member, and the second end of the second timing link is connected to the guide member.

12. The lifting device according to claim 9, wherein the timing mechanism further comprises a rotatable member rotatably mounted on the base, and wherein the second end of the first timing link is pivotally connected to the rotatable member, and the second end of the second timing link is pivotally connected to the rotatable member.

13. The lifting device according to claim 12, wherein the rotatable member includes a pivot arm.

14. A scissor lift, the scissor lift comprising: A base having a first pair of fixed hinge positions and a second pair of fixed hinge positions; A linkage arrangement comprising: a first pair of links and a second pair of links, the first pair of links and the second pair of links being pivotally connected to a first pair of fixed hinge positions and a second pair of fixed hinge positions, respectively, such that the first pair of links and the second pair of links are spaced apart; and a timing mechanism associated with the first pair of links and the second pair of links and configured to coordinate the movement of the first pair of links and the second pair of links such that the first pair of links and the second pair of links can pivot substantially synchronously, wherein the timing mechanism is connected relative to one pair of links of the first pair of links and the second pair of links below a plane extending through the first pair of fixed hinge positions and the second pair of fixed hinge positions; A retractable lifting mechanism includes multiple foldable support members that can cooperate with each other to allow the lifting mechanism to move between a retracted position and an extended position. Each foldable support member includes a first pair of lowermost foldable support members and a second pair of lowermost foldable support members respectively connected to a first pair of links and a second pair of links. Each of the first pair of lowermost foldable support members is pivotally connected to a corresponding foldable support member in the second pair of lowermost foldable support members via a central pivot pin. Platform, the platform being connected to the upper end of the lifting mechanism; and An actuator, the actuator being coupled to at least one of the foldable support members, for moving the lifting mechanism from the retracted position to the unfolded position, wherein the actuator is separate from the timing mechanism; The first pair of links is configured to pivot about a first pivot axis in a first direction when the lifting mechanism moves from the retracted position to the extended position, and the second pair of links is configured to pivot about a second pivot axis in a second direction opposite to the first direction, such that the second pair of links does not overlap with the first pair of links when viewed in a direction parallel to the first and second pivot axes, and wherein the position of the central plane of the lifting mechanism remains substantially unchanged when the lifting mechanism moves between the retracted position and the extended position.

15. The scissor lift of claim 14, wherein the timing mechanism comprises a single pair of timing links connected to the first pair of links and the second pair of links, each of the single pair of timing links comprising a first end connected to the first pair of links and a second end connected to the second pair of links.

16. The scissor lift of claim 15, wherein the linkage arrangement includes a lateral extension member fixedly connected to the first pair of links, and two downwardly extending links fixedly connected to the lateral extension member, and wherein the first end of each timing link in the single pair of timing links is pivotally connected to a corresponding downwardly extending link in the downwardly extending links.

17. The scissor lift of claim 16, wherein for each timing link of the timing links, the first end and the second end respectively define a first connection position and a second connection position, and wherein one of the first connection position and the second connection position is located below the plane extending through the first pair of fixed hinge positions and the second pair of fixed hinge positions, and the other of the first connection position and the second connection position is located above the plane.

18. The scissor lift of claim 14, wherein the timing mechanism comprises a single timing link having a first end connected to the first pair of links and a second end connected to the second pair of links.

19. The scissor lift of claim 18, wherein the linkage arrangement includes a lateral extension member fixedly connected to the first pair of linkages, and the first end of the timing linkage is connected to the lateral extension member.

20. The scissor lift of claim 19, wherein the linkage arrangement further comprises a downwardly extending connecting member fixedly connected to the lateral extension member, and the first end of the timing link is pivotally connected to the downwardly extending connecting member.

21. The scissor lift of claim 19, wherein the linkage arrangement further comprises an additional lateral extension member fixedly connected to the second pair of links, and the second end of the timing link is connected to the additional lateral extension member.

22. The scissor lift of claim 21, wherein the linkage arrangement further comprises a connecting member fixedly connected to the additional lateral extension member, and the second end of the timing link is pivotally connected to the connecting member.

23. A lifting device, the lifting device comprising: The base has a first fixed connection position and a second fixed connection position; A linkage arrangement comprising: a first link and a second link, the first link and the second link being spaced apart from each other and pivotally connected to the base at a first fixed connection position and a second fixed connection position, respectively; and a timing mechanism associated with the first link and the second link and configured to coordinate movement of the first link and the second link such that the first link and the second link can pivot substantially synchronously, wherein the timing mechanism defines a connection position relative to one of the first link and the second link located below a plane extending through the first fixed connection position and the second fixed connection position; A lifting mechanism comprising a plurality of foldable members cooperating with each other, enabling the lifting mechanism to move between a retracted position and an extended position, wherein the plurality of foldable members includes a first foldable member and a second foldable member pivotally connected together by a central pivot pin, and the first foldable member and the second foldable member are pivotally connected to a first link and a second link, respectively; and A platform, which is connected to the upper end of the lifting mechanism; The first and second links of the linkage arrangement are configured to pivot about a first pivot axis and a second pivot axis, respectively, and in opposite directions relative to each other, when the lifting mechanism moves between the retracted and extended positions, and do not overlap when viewed in a direction parallel to the first and second pivot axes. The linkage arrangement is also configured to cooperate with the lifting mechanism such that the position of the central plane through which the lifting mechanism passes between the first and second fixed connection positions remains substantially unchanged as the lifting mechanism moves between the retracted and extended positions.

24. The lifting device of claim 23, further comprising an actuator associated with and configured to move the lifting mechanism from the retracted position to the extended position, wherein the actuator is separate from the timing mechanism, and wherein the lifting mechanism is a scissor lift structure.

25. The lifting device according to claim 23, wherein the timing mechanism includes a timing link connected to the first link and the second link.

26. The lifting device of claim 23, wherein the timing mechanism includes an actuator having a first end connected to the first link and a second end connected to the second link.

27. The lifting device of claim 23, wherein the timing mechanism comprises a first actuator pivotally connected to the first link and a second actuator pivotally connected to the second link.

28. The lifting device according to claim 23, wherein the timing mechanism includes a first gear and a second gear rotatably mounted on the base, and a first timing link and a second timing link, wherein the first timing link has a first end connected to the first link and a second end connected to the first gear, and the second timing link has a first end connected to the second link and a second end connected to the second gear.

29. The lifting device of claim 23, wherein the timing mechanism includes a first timing link and a second timing link and a movable guide member mounted on the base, such that the guide member is movable along a plane located between the first fixed connection position and the second fixed connection position, wherein the first timing link has a first end connected to the first link and a second end connected to the movable guide member, and the second timing link has a first end connected to the second link and a second end connected to the movable guide member.

30. The lifting device of claim 23, wherein the timing mechanism includes a first timing link and a second timing link and a pivot arm pivotally mounted on the base, wherein the first timing link has a first end connected to the first link and a second end connected to the pivot arm, and the second timing link has a first end connected to the second link and a second end connected to the pivot arm.

31. The lifting device according to claim 30, wherein the second end of the first timing link is pivotally connected to a first section of the pivot arm, and the second end of the second timing link is pivotally connected to a second section of the pivot arm.

32. A lifting device, the lifting device comprising: Base; A lifting mechanism that is movable relative to the base between a retracted position and an extended position, wherein the lifting mechanism includes a first support member and a second support member pivotally connected together by a central pivot pin; A linkage arrangement comprising: a first link and a second link spaced apart from each other; and a timing mechanism associated with and configured to coordinate the movement of the first link and the second link such that the first link and the second link can pivot substantially synchronously; and Support components; The first connecting rod and the second connecting rod are connected to the base at a first fixed connection position and a second fixed connection position, and are also connected to the lower end of the lifting mechanism, such that the first connecting rod and the second connecting rod are pivotally connected to the first support member and the second support member, respectively; or the first connecting rod and the second connecting rod are connected to the support assembly at a first fixed connection position and a second fixed connection position, and are also connected to the upper end of the lifting mechanism, such that the first connecting rod and the second connecting rod are pivotally connected to the first support member and the second support member, respectively; and The first link and the second link are configured to pivot about a first pivot axis and a second pivot axis respectively and in opposite directions relative to each other when the lifting mechanism moves between the retracted position and the extended position, and do not overlap when viewed in a direction parallel to the first pivot axis and the second pivot axis, and wherein the timing mechanism defines a connection position located below or above a plane extending through the first fixed connection position and the second fixed connection position.

33. The lifting device of claim 32, further comprising an actuator associated with and configured to move the lifting mechanism from the retracted position to the extended position, wherein the actuator is separate from the timing mechanism.

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