A work platform for vehicle servicing
By combining fixed fences, movable fences, and telescopic fences, the problem of poor adaptability of existing vehicle maintenance platforms has been solved, achieving safe protection and efficient maintenance for different vehicle models.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN BUS GROUP
- Filing Date
- 2025-08-25
- Publication Date
- 2026-07-21
AI Technical Summary
Existing vehicle maintenance platforms lack flexible protective structures and cannot adapt to different vehicle models, resulting in low safety and low maintenance efficiency.
The design combines fixed, movable, and telescopic fences, providing comprehensive protective coverage by dynamically adjusting the fence range to meet the maintenance needs of different vehicles.
It improves operational safety and adaptability, ensures the safety of maintenance personnel during vehicle maintenance, and enhances maintenance efficiency.
Smart Images

Figure CN224530565U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of vehicle maintenance technology, and in particular to a working platform for vehicle maintenance. Background Technology
[0002] The design of guardrails on vehicle maintenance platforms directly impacts operational safety, yet existing platforms suffer from significant deficiencies: one type lacks any protective guardrails, leaving workers vulnerable to falls due to shifted center of gravity when moving or crossing over to the vehicle roof, posing an extremely high safety risk. Another type, while equipped with guardrails, employs fixed structures that are difficult to adapt to different vehicle models. With narrow vehicles, gaps exist between the fixed guardrails and the vehicle's edge, increasing the risk of workers slipping and falling while at the edge of the vehicle, highlighting a significant safety hazard. With wide roofs, the guardrails fail to cover the roof's edge, requiring workers to cross over to reach the edge, leaving them completely exposed and significantly increasing the risk of falls. This lack of adaptability not only reduces maintenance efficiency but also amplifies safety hazards, failing to meet the maintenance needs of multiple vehicle models and high safety standards. Utility Model Content
[0003] The purpose of this utility model is to overcome the shortcomings of existing work platforms, such as insufficient protection, poor flexibility, and low safety, and to provide a work platform for vehicle maintenance.
[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0005] This utility model embodiment provides a work platform for vehicle maintenance, including: a support frame, an operating table, a fixed fence, a telescopic fence, and a movable fence; the operating table is horizontally installed at the top of the support frame; the fixed fence surrounds the left and right sides and the rear edge of the operating table and is fixedly connected to the support frame; the movable fence is located on the front side of the operating table, and the telescopic fence is connected to both the left and right sides of the movable fence, with the end of the telescopic fence away from the movable fence being movably connected to the fixed fence.
[0006] In one embodiment, the telescopic fence includes multiple sub-fences connected sequentially by hinges. The sub-fences located near the fixed fence are connected to the fixed fence by hinges, and the sub-fences located near the movable fence are connected to the movable fence by hinges.
[0007] In one embodiment, an extension platform is movably connected to the front side of the operating table.
[0008] In one embodiment, the extension platform is movably connected to the operating platform via a hinge on the side closest to the operating platform, and the left and right sides of the extension platform are also connected to the fixed fence via connecting ropes.
[0009] In one embodiment, the support frame includes a plurality of columns and a base, with the upper and lower ends of the columns connected to the base and the operating table, respectively.
[0010] In one embodiment, the column includes an outer tube and an inner tube. The bottom of the outer tube is connected to the base, and the top of the outer tube is slidably connected to the bottom of the inner tube. The top of the inner tube is connected to the operating table. A driving component is installed on the top of the outer tube, and the driving component is throttle-connected to the inner tube.
[0011] In one embodiment, a distance sensor is mounted on the bottom of the drive unit, and the distance sensor is communicatively connected to the drive unit.
[0012] In one embodiment, the work platform further includes a ladder, the bottom of which is mounted on the base and the top of which is connected to the operating table.
[0013] In one embodiment, the top of the ladder is connected to the operating table via a hinge, and the bottom is slidably connected to the base via rollers.
[0014] In one embodiment, a pulley assembly is provided below the base, and the pulley assembly is connected to the base by a screw.
[0015] The advantages of this utility model for vehicle maintenance work platform compared with the prior art are as follows: a fixed fence is used to enclose the left and right sides and the rear of the work platform to form basic protection; the movable fence and the telescopic fence work together to dynamically adjust the enclosure range of the fence so that the protection on the front side of the work platform can cover the top of the vehicle, thereby providing a safe working space for maintenance personnel. This not only ensures the stability of the basic protection of the work platform, but also realizes the dynamic adjustment of the fence protection range, which can adapt to the maintenance needs of different vehicles and improve the safety and adaptability of the operation.
[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 A schematic diagram of the working platform for vehicle maintenance when the telescopic fence provided in this embodiment of the utility model is in the retracted state;
[0019] Figure 2 This is a schematic diagram of the working platform for vehicle maintenance when the telescopic fence provided in this embodiment is in the unfolded state.
[0020] Attached Figure Labels
[0021] 1. Support frame; 11. Column; 111. Outer tube; 112. Inner tube; 12. Base; 13. Drive unit; 14. Crossbeam; 15. Reinforcing rib; 16. Distance sensor; 17. Pulley assembly; 2. Operating platform; 3. Fixed fence; 4. Telescopic fence; 41. Sub-fence; 5. Movable fence; 6. Extension platform; 7. Connecting rope; 8. Ladder; 81. Handrail; 82. Rollers; 9. Power supply assembly. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0024] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0026] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0028] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.
[0029] See Figures 1 to 2 As shown, this utility model provides a specific embodiment of a work platform for vehicle maintenance, including: a support frame 1, an operating platform 2, a fixed fence 3, a telescopic fence 4, and a movable fence 5; the operating platform 2 is horizontally installed at the top of the support frame 1; the fixed fence 3 surrounds the left and right sides and the rear edge of the operating platform 2 and is fixedly connected to the support frame 1; the movable fence 5 is located on the front side of the operating platform 2, and telescopic fences 4 are connected to both the left and right sides of the movable fence 5, with the end of the telescopic fence 4 away from the movable fence 5 being movably connected to the fixed fence 3.
[0030] Specifically, the core of this embodiment lies in adapting to the maintenance needs of different vehicles through an adjustable fence structure. Fixed fence 3 encloses the left, right, and rear sides of the operating platform 2, forming basic protection. Movable fence 5 works in conjunction with telescopic fence 4, dynamically adjusting the enclosure range so that the protection on the front of the operating platform 2 can cover the vehicle's roof, thus providing a safe working space for maintenance personnel. When the vehicle roof needs maintenance, the work platform is first moved to the front of the vehicle (or the vehicle is moved to the front of the operating platform 2), and maintenance personnel climb onto the operating platform 2. Then, the telescopic fence 4 is extended, causing the movable fence 5 to move towards the vehicle, placing both the movable fence 5 and the telescopic fence 4 above the vehicle's roof, expanding the enclosure range and bringing the roof under the protection of the fence structure, thus forming full-coverage protection for maintenance personnel. During non-maintenance periods, the telescopic fence 4 and movable fence 5 can be retracted to the vicinity of the fixed fence 3, reducing space occupation and facilitating the storage or movement of the work platform when not in use. The coordinated design of fixed fence 3, movable fence 5 and telescopic fence 4 ensures the stability of the basic protection of the operating platform 2 and realizes the dynamic adjustment of the fence protection range, thereby improving the safety and adaptability of the operation.
[0031] In one specific embodiment, the telescopic fence 4 includes multiple sub-fences 41, which are connected sequentially by hinges (not shown in the figure). The sub-fences 41 located near the fixed fence 3 are connected to the fixed fence 3 by hinges, and the sub-fences 41 located near the movable fence 5 are connected to the movable fence 5 by hinges.
[0032] Specifically, the telescopic function is achieved through the hinge connection of multiple sub-fences 41. The modular design allows for flexible adjustment of the fence length to adapt to different telescopic needs while ensuring structural strength. When the telescopic fence 4 needs to be extended, the movable fence 5 is pushed outward (away from the fixed fence 3), and the multiple sub-fences 41 unfold sequentially via hinges to form a continuous protective surface. When it needs to be shortened, the movable fence 5 is pushed inward, and the sub-fences 41 fold via hinges, reducing space occupation. Furthermore, the hinge connection method is simple and reliable, avoiding the use of complex mechanical structures and reducing costs. Simultaneously, the modular design of the sub-fences 41 facilitates maintenance and replacement; if a sub-fence 41 is damaged, it can be replaced individually rather than the entire structure.
[0033] It is understandable that the telescopic fence 4 can also adopt a pull-out structure or a scissor structure formed by hinges.
[0034] In one specific embodiment, an extension platform 6 is movably connected to the front side of the operating table 2.
[0035] Specifically, after the movable barrier 5 and telescopic barrier 4 on the front side of the control panel 2 cover the top of the vehicle, the extension platform 6 is unfolded from the front of the control panel 2 (e.g., flipped downwards or slid outwards) so that its surface is flush with the control panel 2, forming a larger working surface. Maintenance personnel can stand on the extension platform 6 to perform maintenance on the edge of the vehicle's top or a wider area. The extension platform 6 increases the usable area of the control panel 2, avoiding the operational limitations caused by the control panel 2 being too narrow, and improving maintenance efficiency. At the same time, the movable connection design between the extension platform 6 and the control panel 2 facilitates storage and does not occupy extra space.
[0036] In one specific embodiment, the extension platform 6 is movably connected to the operating platform 2 on the side closest to the operating platform 2 via a hinge, and the left and right sides of the extension platform 6 are also connected to the fixed fence 3 via connecting ropes 7.
[0037] Specifically, when extending the extension platform 6, it is rotated along the hinge to flip it downwards to a horizontal position. At this time, the connecting rope 7 is taut, with one end fixed to both sides of the extension platform 6 and the other end fixed to the fixed fence 3, thus limiting the extension platform 6 from further downward rotation and keeping it flush with the operating platform 2. When storing, the extension platform 6 is lifted upwards, the connecting rope 7 is loosened, and the extension platform 6 is folded back to the front of the operating platform 2 via the hinge. The hinge connection ensures the flexibility of the extension platform 6's rotation, while the connecting rope 7 acts as an auxiliary limiting device to prevent the extension platform 6 from over-flipping due to external forces (such as wind) or operational errors, thus improving structural stability and safety. It is understood that the hinge can be a model with a self-locking function, which automatically locks the angle when the extension platform 6 is extended to a horizontal position; the connecting rope 7 can be made of steel wire rope, high-strength nylon rope, or chain, with both ends connected to the extension platform 6 and the fixed fence 3 via shackles or hooks.
[0038] In other embodiments, the extension table 6 may also adopt a pull-out structure, which can be pulled out from inside the operating table 2 via a slide rail.
[0039] In one specific embodiment, the support frame 1 includes a plurality of columns 11 and a base 12, with the upper and lower ends of the columns 11 connected to the base 12 and the operating table 2, respectively.
[0040] Specifically, the modular assembly of the support frame 1 is achieved through the separate design of the column 11 and the base 12, which facilitates transportation and installation, and makes it easy to adjust the number or layout of the column 11 according to the needs. The column 11, as the main load-bearing component, connects the operating table 2 and the base 12 to ensure the stability of the overall structure. The base 12 increases the contact area with the ground, reduces pressure, and prevents the operating table 2 from sinking into the soft ground.
[0041] Understandably, the base 12 can be integrated with a counterweight (not shown in the figure) to improve anti-tipping ability.
[0042] In one specific embodiment, the column 11 includes an outer tube 111 and an inner tube 112. The bottom of the outer tube 111 is connected to the base 12, and the top is slidably connected to the bottom of the inner tube 112. The top of the inner tube 112 is connected to the operating table 2. A driving component 13 is installed on the top of the outer tube 111, and the driving component 13 is connected to the inner tube 112 in a driving manner.
[0043] Specifically, in this embodiment, the telescopic function of the column 11 is achieved through a sliding connection between the outer tube 111 and the inner tube 112. The bottom of the outer tube 111 is fixed to the base 12, and the top of the inner tube 112 is connected to the operating platform 2. The drive component 13 is installed on the top of the outer tube 111 and directly drives the inner tube 112, forming a compact structure of "outer tube 111 fixed, inner tube 112 lifting". This design integrates the drive component 13 on the top of the outer tube 111, shortening the transmission path and improving the accuracy of lifting control; at the same time, the sliding connection method (such as a slide rail or bearing) reduces the friction between the inner tube 112 and the outer tube 111, ensuring the smoothness of the lifting process.
[0044] Understandably, the drive component 13 can be an electric push rod, a hydraulic cylinder, or other similar device, selected based on actual needs and cost considerations.
[0045] In one specific embodiment, a crossbeam 14 is connected at the top between two adjacent outer tubes 111 on the same side, and the bottom of the drive member 13 is mounted on the crossbeam 14.
[0046] Specifically, the crossbeam 14 enhances the overall structure of the column 11 and improves transmission efficiency. As the top connector of adjacent outer tubes 111, the crossbeam 14 is welded from steel square tubing, enhancing the cooperative load-bearing capacity between the outer tubes 111 and preventing deformation or tilting of the outer tubes 111 during lifting. Simultaneously, the crossbeam 14 provides a stable mounting platform 2 for the drive unit 13, allowing the drive unit 13 to be centrally located at the top of the column 11, shortening the transmission distance with the inner tube 112, and improving power transmission efficiency and control precision.
[0047] In one specific embodiment, a cross-arranged reinforcing rib 15 is provided between two adjacent outer tubes 111, with the top of the reinforcing rib 15 connected to the outer tube 111 and the bottom connected to the base 12.
[0048] Specifically, the overall rigidity and load distribution capacity of the column 11 structure are improved by diagonal cross bracing. The cross stiffeners 15 form a triangular stable structure similar to a truss. When the operating platform 2 is subjected to loads (such as the weight of personnel and tools), the downward pressure on the outer tube 111 is transmitted to the base 12 through the diagonal stiffeners, converting the concentrated load into a dispersed diagonal component force, effectively resisting the deformation or tilting of the outer tube 111. At the same time, the cross layout can resist external forces from the horizontal direction (such as wind force or lateral thrust during operation), maintaining the verticality of the column 11.
[0049] In one specific embodiment, a distance sensor 16 is mounted on the bottom of the drive unit 13, and the distance sensor 16 is communicatively connected to the drive unit 13.
[0050] Specifically, the distance sensor 16 detects the height difference between the operating platform 2 and the top of the vehicle in real time. Based on the sensor feedback, the drive unit 13 automatically adjusts the height of the column 11, achieving intelligent lifting and lowering of the operating platform 2. When the work platform moves near the vehicle, the distance sensor 16 detects the vertical distance from the bottom of the operating platform 2 to the top of the vehicle. The distance sensor 16 transmits the distance data to the control unit of the drive unit 13. The control unit calculates the required extension / retraction of the column 11 and activates the drive unit 13 to adjust the height of the column 11, automatically raising and lowering the operating platform 2 to a safe height that is level with or slightly higher than the top of the vehicle. This intelligent adjustment avoids human error and ensures precise alignment between the operating platform 2 and the top of the vehicle. Simultaneously, the automatic adjustment function improves work efficiency, making it particularly suitable for scenarios requiring frequent maintenance of vehicles at different heights.
[0051] Understandably, the distance sensor 16 can be selected from laser rangefinders, ultrasonic rangefinders, Hall effect sensors, etc., depending on the actual usage environment and accuracy requirements.
[0052] In one specific embodiment, the work platform further includes a ladder 8, the bottom of which is mounted on the base 12 and the top of which is connected to the operating table 2.
[0053] Specifically, ladder 8 serves as the access route to and from the base, featuring a simple, reliable, and low-cost structure. The design, with its bottom fixed to base 12 and top connected to operating platform 2, avoids gaps between ladder 8 and operating platform 2, preventing maintenance personnel from slipping and falling. Understandably, handrails 81 are provided on both sides of ladder 8 to enhance safety when ascending and descending.
[0054] In one specific embodiment, the top of the ladder 8 is connected to the operating table 2 via a hinge, and the bottom is slidably connected to the base 12 via rollers 82.
[0055] Specifically, this embodiment utilizes a combination of hinges and rollers 82 to allow the top of the ladder 8 to rotate as the operating platform 2 rises and falls, while the bottom is adjusted by sliding on the base 12 via the rollers 82, thus achieving automatic synchronization between the height of the ladder 8 and the operating platform 2. The hinges provide the rotational freedom between the top of the ladder 8 and the operating platform 2, while the rollers 82 compensate for positional changes caused by the rising and falling of the operating platform 2, ensuring that the ladder 8 always maintains a reasonable tilt angle and effective height, providing a stable access route for maintenance personnel.
[0056] Understandably, the rollers 82 installed at the bottom of the ladder 8 are universal rollers 82 with brake function; the base 12 is provided with a slide rail, and the rollers 82 slide along the slide rail to limit the movement direction of the bottom of the ladder 8 and prevent deviation; the braking device of the rollers 82 is controlled by a foot pedal or handle, and the brake pads are stepped on when fixed to prevent the ladder 8 from sliding accidentally.
[0057] In one specific embodiment, a pulley assembly 17 is provided below the base 12, and the pulley assembly 17 is connected to the base 12 by a screw.
[0058] Specifically, by setting a pulley assembly 17 under the base 12, the work platform is easy to move. The screw connection facilitates the installation and disassembly of the pulley assembly 17, and the height of the base 12 can be adjusted as needed by adjusting the length of the screw to adapt to uneven ground.
[0059] Preferably, the pulley assembly 17 includes, but is not limited to, a steering wheel (not shown in the figure) and a directional wheel (not shown in the figure). The combination of the steering wheel and the directional wheel enables the flexible movement and stable fixation of the work platform. The steering wheel facilitates the adjustment of direction, and the directional wheel ensures the stability of linear movement. The combination of the steering wheel and the directional wheel takes into account both the flexibility of movement and the stability of fixation.
[0060] In one specific embodiment, a power supply component 9 is also installed on the support frame 1, and the power supply component 9 is electrically connected to the drive component 13 and the distance sensor 16.
[0061] Preferably, the power supply component 9 is installed below the crossbeam 14. This embodiment achieves centralized power supply and optimized wiring by installing the power supply component 9 on the support frame 1 and electrically connecting the drive component 13 and the distance sensor 16. The power supply component 9 is installed below the crossbeam 14, utilizing the structural strength of the crossbeam 14 to provide physical protection against external impacts or environmental erosion (such as rain or dust), thus improving power supply stability. Simultaneously, the location below the crossbeam 14, close to the drive component 13 (such as a motor) and the distance sensor 16, shortens the power supply line length, reduces line clutter and signal attenuation, and ensures the reliability of the drive component 13's precise control and the sensor's real-time distance measurement functions. Furthermore, the centralized power supply design reduces maintenance difficulty, facilitates fault diagnosis and power management, and overall improves the system integration and operational stability of the work platform. In other embodiments, the power supply component 9 can also be installed on the base 12, column 11, or other locations.
[0062] Understandably, the power supply component 9 can be selected from lead-acid batteries, lithium-ion batteries, mains power modules, etc., based on actual needs (such as portability, power supply stability, cost).
[0063] The above embodiments are preferred implementations of this utility model. In addition, this utility model can also be implemented in other ways. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this utility model.
Claims
1. A work platform for vehicle maintenance, characterized in that, include: Support frame, operating platform, fixed fence, telescopic fence and movable fence; The operating platform is horizontally mounted on the top of the support frame; The fixed fence surrounds the left and right sides and the rear edge of the operating table and is fixedly connected to the support frame; the movable fence is located on the front side of the operating table, and the telescopic fence is connected to both sides of the movable fence, with the end of the telescopic fence away from the movable fence being movably connected to the fixed fence.
2. The work platform for vehicle maintenance according to claim 1, characterized in that, The telescopic fence includes multiple sub-fences, which are connected sequentially by hinges. The sub-fences located near the fixed fence are connected to the fixed fence by hinges, and the sub-fences located near the movable fence are connected to the movable fence by hinges.
3. The work platform for vehicle maintenance according to claim 1, characterized in that, An extension platform is movably connected to the front side of the control panel.
4. The work platform for vehicle maintenance according to claim 3, characterized in that, The extension platform is movably connected to the operating platform via a hinge on the side closest to the operating platform, and the left and right sides of the extension platform are also connected to the fixed fence via connecting ropes.
5. The work platform for vehicle maintenance according to claim 1, characterized in that, The support frame includes several columns and a base, with the upper and lower ends of the columns connected to the base and the operating table, respectively.
6. The work platform for vehicle maintenance according to claim 5, characterized in that, The column includes an outer tube and an inner tube. The bottom of the outer tube is connected to the base, and the top is slidably connected to the bottom of the inner tube. The top of the inner tube is connected to the operating table. A driving component is installed on the top of the outer tube, and the driving component is pulsatorically connected to the inner tube.
7. The work platform for vehicle maintenance according to claim 6, characterized in that, A distance sensor is mounted on the bottom of the drive unit, and the distance sensor is communicatively connected to the drive unit.
8. The work platform for vehicle maintenance according to claim 6, characterized in that, The work platform also includes a ladder, the bottom of which is mounted on the base and the top of which is connected to the operating table.
9. The work platform for vehicle maintenance according to claim 8, characterized in that, The top of the ladder is connected to the operating table via a hinge, and the bottom is slidably connected to the base via rollers.
10. The work platform for vehicle maintenance according to claim 6, characterized in that, A pulley assembly is provided below the base, and the pulley assembly is connected to the base by a screw.