A platform fall arrest device

Abstract

The application discloses a platform anti-falling device, which comprises an eccentric wheel, a limiting block and an upper lifting joint, the upper lifting joint is provided with a strip-shaped hole extending along the moving direction of the upper lifting joint, the limiting block is inserted into the strip-shaped hole and is in sliding fit with the strip-shaped hole along the extension direction of the strip-shaped hole, a reset spring for pulling down the upper lifting joint is connected between the upper lifting joint and the platform, the platform is provided with a sliding rail mechanism in sliding fit with the platform, the eccentric wheel is in transmission connection with the upper lifting joint, the eccentric wheel is provided with a separation part and a pressing part which are arranged in sequence along the circumferential direction, the pressing part is pressed on the sliding rail mechanism after the upper lifting joint moves downward and the eccentric wheel rotates, the separation part is opposite to the sliding rail mechanism after the upper lifting joint moves upward and the eccentric wheel rotates, and the separation part is arranged in interval with the sliding rail mechanism, the upper lifting joint can be moved before the platform moves under the pulling action of the reset spring, the action of the eccentric wheel pressing against the sliding rail mechanism can be quickly completed, and the platform cannot move downward any more, thereby avoiding the delay of the anti-falling work in the prior art.

Description

Technical Field

[0001] This invention relates to the field of fall protection technology, and in particular to a platform fall protection device. Background Technology

[0002] With the rapid development of the construction industry, the number of high-rise and super high-rise buildings is increasing year by year, making transportation platforms indispensable for material storage and loading / unloading. Existing transportation platforms rely on wire ropes to lift a driven wheel, which poses a risk of falling if the wire rope breaks. A proposed fall-prevention lifting platform (CN109534246B) includes a lifting platform body and columns. The columns are spaced apart on both sides of the lifting platform body, forming side walls. Each side wall has a driven wheel on its inner side and a fall-prevention component on its outer side. This component engages with the columns to prevent the lifting platform from falling. While this design prevents the platform from falling if the wire rope breaks, the fall-prevention component still requires a period of time during the fall before it activates, inevitably causing a delay in the fall prevention mechanism. Summary of the Invention

[0003] The purpose of this invention is to provide a platform fall prevention device to solve the problems existing in the prior art. It can quickly complete the action of the eccentric wheel pressing against the slide rail mechanism by lifting the joint under the action of the return spring, thereby ensuring that the platform no longer moves down and avoiding the delay in fall prevention work in the prior art.

[0004] To achieve the above objectives, the present invention provides the following solution: The present invention provides a platform fall protection device, comprising an eccentric wheel rotatably connected to a platform, a limiting block fixed to the platform, and an upper lifting joint movably disposed on the platform in a vertical direction for lifting the platform. The upper lifting joint has a strip-shaped hole extending in its moving direction. The limiting block is inserted into the strip-shaped hole and slides with it in the extending direction of the strip-shaped hole. A return spring for pulling down the upper lifting joint is connected between the upper lifting joint and the platform. The platform is equipped with a slide rail mechanism that slides with it. The eccentric wheel is drivenly connected to the upper lifting joint and has a separation part and a pressing part arranged sequentially in a circumferential direction. The pressing part presses against the slide rail mechanism after the upper lifting joint moves down and the eccentric wheel rotates. The separation part faces the slide rail mechanism after the upper lifting joint moves up and the eccentric wheel rotates, and is spaced apart from the slide rail mechanism.

[0005] Preferably, the eccentric wheel includes an eccentric wheel body, which is divided into the separating part and the extruding part in sequence along its circumference.

[0006] Preferably, the radius of the eccentric wheel body gradually increases from the separation section to the compression section.

[0007] Preferably, the eccentric wheel body is provided with a meshing part located circumferentially between the extrusion part and the separation part, and the lifting connector is provided with a rack extending in the vertical direction, the rack meshing with the meshing part for transmission.

[0008] Preferably, the slide rail mechanism includes a vertically extending bearing surface, on which a strip-shaped protrusion extends in the same direction, and on which a vertical slide groove is provided on the platform for fastening and sliding connection with the strip-shaped protrusion.

[0009] Preferably, the platform has an installation channel on the side near the bearing surface, the eccentric wheel body and the lifting connector are both located in the installation channel, the vertical slide groove includes two sidewalls that are spaced apart in the horizontal direction and both extend in the vertical direction, one of the sidewalls separates the vertical slide groove and the installation channel, the separating part is spaced apart from the corresponding sidewall, and the pressing part abuts against the corresponding sidewall and presses the strip protrusion.

[0010] Preferably, the inner surface of the vertical groove and the outer surface of the strip-shaped protrusion both have a textured surface.

[0011] Preferably, a pair of pulleys are rotatably connected to the platform. The pulleys are symmetrically arranged on both sides of the strip-shaped protrusion in the horizontal direction. The two side walls of the vertical slide groove are provided with openings for the pulleys to expose and contact the strip-shaped protrusion.

[0012] Preferably, the platform includes a load-bearing part and a sliding part distributed in a horizontal direction. The load-bearing part is equipped with goods to be lifted and transported, and the sliding part is provided with a plurality of pairs of pulleys, with each pair of pulleys being equally spaced in a vertical direction.

[0013] Preferably, the top of the lifting joint is connected to a wire rope for lifting it to the platform.

[0014] The present invention achieves the following technical effects compared to the prior art:

[0015] First, because the lifting connector used to lift the platform is connected to the eccentric wheel drive, when the platform needs to be lifted, the lifting connector moves upward, pulling the return spring. The strip-shaped hole moves with the lifting connector, and its bottom contacts the limit block, which in turn drives the platform upward. Simultaneously, the return spring is stretched, and the movement of the lifting connector drives the eccentric wheel to rotate. The separating part on the eccentric wheel faces the slide rail mechanism, creating a gap between it and the slide rail mechanism to ensure smooth platform lifting. When the lifting head suddenly disconnects from the lifting drive mechanism, the return spring, under its elastic force, quickly pulls the lifting connector downward. The platform moves, causing the eccentric wheel to rotate. The pressing part on the eccentric wheel contacts the slide rail mechanism and applies a pressing force to the slide rail mechanism. Then, the platform will fall under the action of gravity, causing the platform and the limiting block to move downward relative to the lifting joint. When the limiting block presses down on the strip hole, it will increase the pressing of the eccentric wheel on the slide rail mechanism, thereby completing the locking. In the whole process, the lifting joint can move before the platform under the action of the return spring, quickly completing the action of the eccentric wheel pressing against the slide rail mechanism, thus ensuring that the platform no longer moves downward, avoiding the delay in the anti-fall operation in the prior art.

[0016] Second, the eccentric wheel includes an eccentric wheel body, which is divided into a separation part and a compression part along its circumference. That is to say, the separation part and the compression part are each part of the structure of the eccentric wheel body, and there is no need to set up an additional separation part and compression part to connect with the eccentric wheel body, and it ensures that the compression of the slide rail mechanism is sufficient.

[0017] Third, the radius of the eccentric wheel body gradually increases from the separation part to the compression part. By linearly changing the radius of the eccentric wheel body, the eccentric wheel body can gradually compress the slide rail mechanism as it rotates with the lifting joint, ensuring the gradual and effective compression of the slide rail. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 The eccentric wheel design dimensions for this invention Figure 1 ;

[0021] Figure 3 The eccentric wheel design dimensions for this invention Figure 2 ;

[0022] Among them, 1-steel wire rope, 2-lifting connector, 3-strip hole, 4-limiting block, 5-eccentric wheel, 6-slide rail mechanism, 7-pulley, 8-reset spring, 9-platform, 10-installation channel. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The purpose of this invention is to provide a platform fall prevention device to solve the problems existing in the prior art. It can quickly complete the action of the eccentric wheel pressing against the slide rail mechanism by lifting the joint under the action of the return spring, thereby ensuring that the platform no longer moves down and avoiding the delay in fall prevention work in the prior art.

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] like Figures 1 to 3 As shown, this embodiment provides a platform fall prevention device, including an eccentric wheel 5 rotatably connected to a platform 9, a limiting block 4 fixed to the platform 9, and an upper lifting joint 2 movably disposed on the platform 9 in the vertical direction for lifting the platform 9. Preferably, the top end of the upper lifting joint 2 is connected to a steel wire rope 1 for lifting it to the platform 9. Through the cooperation of the steel wire rope 1 and the winch, the upper lifting joint 2 can move up and down through the steel wire rope 1. The lifting connector 2 has a strip-shaped hole 3 extending along its moving direction. The limiting block 4 is inserted into the strip-shaped hole 3 and slides along the extension direction of the strip-shaped hole 3. Preferably, the limiting block 4 has a columnar structure, and the two ends of the strip-shaped hole 3 along its extension direction are respectively arc-shaped mechanisms that match the structure of the limiting block 4 to ensure full contact between the two and avoid shaking. The lifting connector 2 is connected to the platform 9 by a return spring 8 for pulling down the lifting connector 2. The platform 9 is equipped with a slide rail mechanism 6 that slides with it. The eccentric wheel 5 is driven by the lifting connector 2. Specifically, the rotation axis of the eccentric wheel 5 extends horizontally. During the upward or downward movement of the lifting structure, the eccentric wheel 5 can be driven to rotate through the transmission mechanism. It has a separation part and a pressing part arranged in sequence along the circumference. The pressing part is pressed onto the slide rail mechanism 6 after the lifting connector 2 moves down and the eccentric wheel 5 rotates. The separation part faces the slide rail mechanism 6 after the lifting connector 2 moves up and the eccentric wheel 5 rotates, and is spaced apart from the slide rail mechanism 6.

[0027] Since the lifting connector 2 used to lift the platform 9 is connected to the eccentric wheel 5, when the platform 9 needs to be lifted, the lifting connector 2 moves upward, pulling the return spring 8. The strip hole 3 moves with the lifting connector 2, and its bottom contacts the limit block 4, which in turn drives the platform 9 to rise. Simultaneously, the return spring 8 is stretched, and the movement of the lifting connector 2 drives the eccentric wheel 5 to rotate. The separating part on the eccentric wheel 5 faces the slide rail mechanism 6, creating a gap between it and the slide rail mechanism 6 to ensure the platform 9 rises smoothly. When the lifting head suddenly disconnects from the lifting drive mechanism, the return spring 8, under its elastic force, quickly pulls down the lifting connector 2. As the platform 9 moves, it drives the eccentric wheel 5 to rotate. The pressing part on the eccentric wheel 5 contacts the slide rail mechanism 6 and applies a pressing force to the slide rail mechanism 6. Then, the platform 9 will fall under the action of gravity, causing the platform 9 and the limiting block 4 to move downward relative to the lifting joint 2. When the limiting block 4 presses down on the strip hole 3, it will increase the pressing of the pressing part of the eccentric wheel 5 on the slide rail mechanism 6, thereby completing the locking. In the whole process, the lifting joint 2 can move before the platform 9 under the pulling action of the return spring 8, and quickly complete the action of the eccentric wheel 5 pressing against the slide rail mechanism 6, thereby ensuring that the platform 9 no longer moves downward, avoiding the delay in the anti-fall operation in the prior art.

[0028] The eccentric wheel 5 includes an eccentric wheel 5 body, which is divided into a separation part and a pressing part along its circumference. That is to say, the separation part and the pressing part are part of the structure of the eccentric wheel 5 body, and there is no need to set up an additional separation part and pressing part to connect with the eccentric wheel 5 body, which ensures that the pressing of the slide rail mechanism 6 is sufficient.

[0029] Moreover, the radius of the eccentric wheel 5 gradually increases from the separation part to the compression part. By linearly changing the radius of the eccentric wheel 5, the eccentric wheel 5 can gradually compress the slide rail mechanism 6 as it rotates with the lifting joint 2, ensuring the gradual and effective compression of the slide rail.

[0030] In a preferred embodiment of the present invention, the eccentric wheel 5 body is provided with a meshing part located circumferentially between the extrusion part and the separation part, and the lifting connector 2 is provided with a rack extending in the vertical direction. The rack meshes with the meshing part for transmission. The meshing part is part of the structure of the eccentric wheel 5 body, and its outer peripheral edge is provided with meshing teeth. The meshing part is then connected to the rack through the meshing teeth. During the upward or downward movement of the lifting connector 2, the rack moves with it. The rack meshes with the meshing part, so that the rack can drive the eccentric wheel 5 to rotate effectively, and fully avoids problems such as the eccentric wheel 5 rotating back.

[0031] Furthermore, the slide rail mechanism 6 includes a vertically extending bearing surface, on which a strip-shaped protrusion extends in the same direction. The platform 9 is provided with a vertical slide groove that engages and slides on the strip-shaped protrusion. The vertical slide groove engages and slides on the strip-shaped protrusion to ensure the stability of the platform 9 sliding along the strip-shaped protrusion.

[0032] In a preferred embodiment of the present invention, an installation channel 10 is provided on the side of the platform 9 near the bearing surface. The eccentric wheel 5 and the lifting connector 2 are both located in the installation channel 10. The vertical slide groove includes two sidewalls that are spaced apart in the horizontal direction and extend in the vertical direction. One sidewall separates the vertical slide groove and the installation channel 10. The separating part is spaced apart from the corresponding sidewall. The pressing part abuts against the corresponding sidewall and presses the strip-shaped protrusion. That is, the pressing part presses the corresponding sidewall, and the sidewall abuts against the strip-shaped protrusion, thereby generating a corresponding frictional force between them, which is sufficient to drive the platform 9 to stop moving downward. Preferably, in order to ensure that the frictional force between the sidewall of the vertical slide groove and the strip-shaped protrusion is sufficient, the inner surface of the vertical slide groove and the outer surface of the strip-shaped protrusion are both roughened. Furthermore, in order to reduce the complexity of setting the roughened structure, it is preferable to set the roughness between the inner surface of the corresponding sidewall and the outer surface of the strip-shaped protrusion.

[0033] As another preferred embodiment, the vertical slide groove has an opening on the side wall near the eccentric wheel 5. After the eccentric wheel 5 rotates, the pressing part can extend into the vertical slide groove through the opening and abut against the strip protrusion. The other side wall is driven by the reaction force to approach the strip protrusion, so as to fully ensure the braking effect on the platform 9.

[0034] The platform 9 is rotatably connected to a pair of pulleys 7, which are symmetrically arranged on both sides of the strip-shaped protrusion in the horizontal direction. Openings are provided on both sides of the vertical sliding groove for the pulleys 7 to expose themselves and contact the strip-shaped protrusion. The pair of pulleys 7 allows the platform 9 to slide smoothly on the strip-shaped protrusion, ensuring a smooth sliding connection between the platform 9 and the protrusion. The pulleys 7 can be directly replaced by bearings. Preferably, the radial cross-section of the strip-shaped protrusion is I-shaped, and the pulleys 7 abut against the grooves on both sides of the I-shaped structure. The external structure of the pulleys 7 is adapted to the structure of the grooves on both sides to ensure the stability of the sliding of the platform 9.

[0035] Furthermore, the platform 9 includes a load-bearing part and a sliding part distributed in the horizontal direction. The load-bearing part is equipped with goods to be lifted and transported, and the sliding part is provided with several pairs of pulleys 7. Each pair of pulleys 7 is equally spaced in the vertical direction. Through the cooperation of multiple pairs of pulleys 7 and strip protrusions, the stability of the platform 9 when moving is further ensured.

[0036] As a preferred embodiment of the present invention, such as Figure 2As shown, when the wire rope is normally lifting the platform, the eccentric wheel (integrated with the gear) and the center O1, O of the support shaft are on the X-line, the eccentricity is 001e, and the distance between the outer circle of the eccentric wheel and the slide rail is h. Figure 3 As shown, when the wire rope breaks, the return spring pulls the rack connected to the lifting joint downwards, driving the gear of the eccentric wheel to rotate by an angle α, causing the eccentric wheel to eliminate the distance h and press against the slide rail mechanism. As the platform falls, it presses even tighter, thus quickly locking the platform and stopping its descent. Several calculations are involved in the locking of the eccentric wheel.

[0037] 1. The distance e between the center 01 of the eccentric wheel and the center 0 of its rotation axis is 0 = 001 and lies on the X-axis. When the eccentric wheel rotates around 0 by an angle a, the relationship between the lift h of its outer circle D in the X direction and the equation (see...) Figure 3 ):

[0038] h=e(1-cosα)---[1]

[0039] Lift in the Y direction:

[0040] hy=esinα---[2]

[0041] 2. Force analysis of the eccentric wheel when locking the platform (according to...) Figure 3 The normal force N of the slide rail mechanism on the eccentric wheel, the force P of the rotating shaft on the eccentric wheel, and F are the frictional forces between the slide rail mechanism and the eccentric wheel.

[0042] F=W=fN---[3]

[0043] In equation [3], f is the friction coefficient between the eccentric wheel and the slide rail mechanism. It is related to the material and surface quality. W is the platform gravity. Figure 3 The angle θ between the lines of action of forces P and N is the self-locking angle that the eccentric wheel must satisfy when clamping.

[0044] fgθ=h y / (D / 2-ecosa)=esinα / (D / 2-ecosα)≤f---[4]

[0045] 3. Determining relevant dimensions when clamping the eccentric wheel.

[0046] 3.1 When the eccentricity e between the outer center of the eccentric wheel and the shaft, the rotation angle a when clamped, and the friction coefficient f of the clamping surface are known,

[0047] From formula [4] tagθ=esinα / (D / 2-ecosα)≤f, we get: D≥2esinα / f+2ecosa,

[0048] That is, D≥2e(sinα / f+cosα)---[5]

[0049] 3.2 Distance from the center 0 of the eccentric wheel shaft to the clamping surface of the slide rail mechanism:

[0050] a=D / 2-ecosα---[6]

[0051] 4 Calculation Examples

[0052] Assuming the eccentricity e of the eccentric wheel is 5mm, the rotation angle during fall prevention is:

[0053] α = 45°, f = 0.15.

[0054] 4.1 Outer diameter of eccentric wheel:

[0055] D≥2e(sinα / f+cosα)=2x5×(sin45° / 0.15+cos45°)=54.212

[0056] For safety reasons, we set D = 70mm.

[0057] 4.2 Distance from the center 0 of the eccentric wheel shaft to the clamping surface of the slide rail mechanism:

[0058] a=D / 2-ecosα-70 / 2-5×cos45°-31.464mm.

[0059] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0060] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0061] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A platform fall arrest device, characterised in that, The eccentric wheel is rotationally connected to the platform, the limiting block is fixed to the platform, the upper lifting joint is movably arranged on the platform in the vertical direction and is used to lift the platform, the upper lifting joint is provided with a strip-shaped hole extending along the moving direction of the upper lifting joint, the limiting block is inserted into the strip-shaped hole and is in sliding fit with the strip-shaped hole along the extension direction of the strip-shaped hole, the upper lifting joint and the platform are connected with the reset spring which pulls down the upper lifting joint, the platform is matched with the sliding rail mechanism in sliding fit, the eccentric wheel is in transmission connection with the upper lifting joint, the eccentric wheel is provided with the separation part and the extrusion part which are arranged in sequence in the circumferential direction, the extrusion part is extruded on the sliding rail mechanism after the upper lifting joint moves downward and the eccentric wheel rotates, and the separation part is opposite to the sliding rail mechanism after the upper lifting joint moves upward and the eccentric wheel rotates, and the separation part is arranged in interval with the sliding rail mechanism. When the platform needs to be lifted, the upper lifting joint moves upward and pulls the reset spring, and when the upper lifting joint is disconnected with the lifting driving mechanism, the reset spring pulls down the upper lifting joint under the action of the elastic force. The eccentric wheel includes the eccentric wheel body, the eccentric wheel body is sequentially divided into the separation part and the extrusion part along the circumferential direction, the radius of the eccentric wheel body gradually increases from the separation part to the extrusion part, the engagement part is arranged between the extrusion part and the separation part along the circumferential direction of the eccentric wheel body, the upper lifting joint is provided with the rack extending in the vertical direction, the rack is in transmission with the engagement part, the sliding rail mechanism includes the bearing surface extending in the vertical direction, the bearing surface is provided with the strip-shaped protrusion extending in the same direction, and the vertical sliding groove is arranged on the platform in buckling and sliding connection with the strip-shaped protrusion.

2. The platform fall arrest device of claim 1, wherein, The platform is provided with the installation channel on the side close to the bearing surface, the eccentric wheel body and the upper lifting joint are located in the installation channel, the vertical sliding groove includes two side walls which are arranged in interval in the horizontal direction and extend in the vertical direction, one side wall separates the vertical sliding groove and the installation channel, the separation part is arranged in interval with the corresponding side wall, the extrusion part abuts on the corresponding side wall and extrudes the strip-shaped protrusion.

3. The platform arrestment device of claim 2, wherein, The inner surface of the vertical sliding groove and the outer surface of the strip-shaped protrusion are both in the rough surface structure.

4. The platform arrestment device of claim 3, wherein, The platform is rotationally connected with the pulleys arranged in pairs, the pulleys are symmetrically arranged on both sides of the strip-shaped protrusion in the horizontal direction, and the two side walls of the vertical sliding groove are both provided with the openings for the pulleys to expose and contact the strip-shaped protrusion.

5. The platform arrestment device of claim 4, wherein, The platform includes the bearing part and the sliding part which are distributed in the horizontal direction, the bearing part is provided with the goods to be lifted and conveyed, and the sliding part is provided with a plurality of pairs of pulleys which are equally spaced in the vertical direction.

6. The platform arrestment device of claim 5, wherein, The top end of the upper lifting joint is connected with the steel wire rope for lifting the platform.

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