Adjustable lifting platform lifting anti-pressing foot device of lift truck and working method

Abstract

The present application relates to the technical field of working vehicles, and discloses an adjustable lifting working vehicle rear platform lifting anti-foot-pressing device and a working method, which comprises a first fixed frame fixedly arranged below the tail of the working vehicle, a first telescopic frame in sliding connection with the first fixed frame, a baffle with both ends fixedly connected with the first telescopic frame and used for shielding the gap between the lifting platform and the tail of the working vehicle, a protruding portion provided at the bottom of the baffle and in movable abutment with the lower surface of the lifting platform, and an elastic reset member with both ends connected with the first fixed frame and the baffle respectively. The elastic reset member is in a pre-tensioned state, and the protruding portion always has a tendency to be tightly attached to the lifting platform upward through the tension. The anti-foot-pressing device realizes the real-time shielding of the dynamic gap by the baffle. Moreover, the baffle is decoupled from the lifting platform and is provided with a stroke difference, so that the baffle can be early limited and sealed to the gap in the rising stage.

Description

Technical Field

[0001] This invention relates to the technical field of work vehicles, and in particular to an adjustable lifting work vehicle rear platform lifting anti-foot-pressing device and its working method. Background Technology

[0002] In logistics warehousing, engineering maintenance, and material handling, various types of work vehicles (such as scissor lifts and material handling vehicles) are typically equipped with vertically lifting work platforms. During the lifting and lowering of the work platform, a gap that dynamically changes with the height is formed between the edge of the platform and the vehicle's fixed frame.

[0003] In existing technologies, although some lifting platforms are equipped with fixed guardrails, these primarily aim to protect personnel from falls. When the platform descends, the dynamic gap between the platform bottom and the fixed components below often lacks effective real-time protection. If operators stand improperly at the platform edge, or if foreign objects intrude into this gap, serious accidents such as foot crushing, squeezing, or shearing can easily occur. Summary of the Invention

[0004] In view of the problem of feet being easily trapped in the existing lifting platforms of work vehicles, the present invention is proposed.

[0005] Therefore, the purpose of this invention is to provide an adjustable lifting platform rear platform anti-foot-pinching device and its working method, the purpose of which is to prevent feet from being pinched during lifting.

[0006] To solve the aforementioned technical problem of foot pinching, the present invention provides the following technical solution: an adjustable lifting platform anti-foot-pinching device for a lifting work vehicle, comprising a first fixed frame, fixedly installed below the rear of the work vehicle; a first telescopic frame, slidably connected to the first fixed frame; a baffle, fixedly connected at both ends to the first telescopic frame, used to cover the gap between the lifting platform and the rear of the work vehicle; the bottom of the baffle has a protrusion, which movably abuts against the lower surface of the lifting platform; an elastic reset member, whose two ends are respectively connected to the first fixed frame and the baffle; the elastic reset member is in a pre-stretched state, and the protrusion always tends to press against the lifting platform upwards through the tension.

[0007] As a preferred embodiment of the adjustable lifting operation vehicle rear platform lifting anti-foot-pressing device of the present invention, the rear of the operation vehicle is further provided with a second fixed frame, and the second fixed frame is slidably connected to a second telescopic frame; the lifting platform is fixedly connected to the bottom of the second telescopic frame.

[0008] As a preferred embodiment of the adjustable lifting operation vehicle rear platform lifting anti-foot-pressing device of the present invention, wherein: the rising stroke L1 of the baffle is less than the rising stroke L2 of the lifting platform; when the lifting platform moves upward to the baffle and the top end of the first fixed frame abuts at the limit, the baffle stops moving, the lifting platform disengages from the protrusion and continues to move upward.

[0009] As a preferred embodiment of the adjustable lifting platform anti-foot-pressing device for the lifting work vehicle of the present invention, wherein: the first fixed frame forms a guide cavity into which at least part of the first telescopic frame extends and slides vertically, the guide cavity is surrounded by three side walls of the first fixed frame, and forms an opening extending in the lifting direction in the direction toward the outer side of the first telescopic frame; a guide member is provided between the first fixed frame and the first telescopic frame, the guide member includes a guide part and a follower support part, the guide part is provided on the first fixed frame and extends in the lifting direction of the baffle, the follower support part includes a base provided on the outer side of the first telescopic frame, the follower support part rises and falls with the first telescopic frame, and is provided with a rolling element that rolls in contact with the guide part.

[0010] As a preferred embodiment of the adjustable lifting platform anti-foot-pressing device for the lifting operation vehicle of the present invention, wherein: the guide portion is a limiting rail protruding from the inner side wall of the first fixed frame toward the first telescopic frame, and the limiting rail extends in the vertical direction; the base forms a holding cavity surrounding the outer periphery of the limiting rail, and has a front support portion and a rear support portion respectively located on the front and rear sides of the limiting rail, and a lateral support portion located on the side of the limiting rail facing the first telescopic frame; the rolling element includes a front roller, a rear roller, and a lateral roller respectively disposed on the front support portion, the rear support portion, and the lateral support portion, and the front roller, the rear roller, and the lateral roller respectively roll in contact with the front guide surface, the rear guide surface, and the lateral guide surface of the limiting rail.

[0011] As a preferred embodiment of the adjustable lifting platform anti-foot-pressurization device for the lifting operation vehicle of the present invention, wherein: the guide portion is formed by the inner wall surface of the three side walls of the first fixed frame; the base is a hinged support seat, the hinged support seat includes a mounting plate connected to the outer side surface of the first telescopic frame, and a hinged support portion disposed on the mounting plate, the hinged support portion being rotatably connected to a cradle; the rolling element includes three rollers disposed at the top of the cradle, the three rollers being respectively disposed facing the inner wall surface of the three side walls, and respectively rollingly contacting the corresponding inner wall surface.

[0012] As a preferred embodiment of the adjustable lifting operation vehicle rear platform lifting anti-foot-pressing device of the present invention, wherein: an elastic return component is provided between the cradle and the first telescopic frame, the elastic return component includes a pressure rod, a box body and an elastic pressure block, the pressure rod is connected to the cradle and swings with the cradle, the box body is disposed in the first telescopic frame, and the elastic pressure block is disposed in the box body; the pressure rod extends into the box body and presses the elastic pressure block when the cradle swings relative to the hinged support.

[0013] As a preferred embodiment of the adjustable lifting platform anti-foot-crushing device for the lifting operation vehicle described in this invention, the pressure rod is provided with a sliding groove, and a sliding column and an internal spring are provided inside the pressure rod. The sliding column is slidably arranged along the sliding groove. One end of the internal spring abuts against the pressure rod, and the other end abuts against the sliding column. The sliding column has an abutting end facing the inner wall of the box. The abutting end of the sliding column extends out of the pressure rod through the sliding groove. When the swing amplitude of the rocker arm increases, the inner wall of the box presses against the abutting end, causing the sliding column to move along the sliding groove and compress the internal spring.

[0014] As a preferred embodiment of the adjustable lifting operation vehicle rear platform lifting anti-foot-pressing device of the present invention, the elastic return component is in two sets, and the two sets of elastic return components are respectively arranged on both sides of the cradle; when the cradle swings to one side, the pressure rod of one set of elastic return components presses the corresponding elastic pressure block; when the cradle swings to the other side, the pressure rod of the other set of elastic return components presses the corresponding elastic pressure block.

[0015] Another object of the present invention is to provide a working method for an adjustable lifting platform rear platform anti-foot-damping device for an adjustable lifting work vehicle, applicable to the aforementioned adjustable lifting platform rear platform anti-foot-damping device, wherein: it includes, When the lifting platform moves downward, its lower surface presses against the protrusion, overcoming the tension of the elastic reset member, and causing the baffle and the first telescopic frame to move downward. When the lifting platform moves upward, the elastic reset member releases the tension, causing the baffle to move upward synchronously to block the gap; when the baffle rises to the point where it is limited by the top of the first fixed frame, the baffle stops moving, the lifting platform disengages from the protrusion and continues to rise until the predetermined position.

[0016] The beneficial effects of this invention are as follows: The baffle of this invention, through its protruding portion and movable contact with the lifting platform, combined with the pre-tension force of the elastic reset component, achieves real-time blocking of dynamic gaps. Furthermore, the baffle is decoupled from the lifting platform and has a stroke difference, allowing the baffle to pre-stop and seal the gap during the rising phase, while the lifting platform can detach from the baffle and continue running to the same height, completely eliminating the risk of injury from being pinched at a high position.

[0017] By setting a guide between the first fixed frame and the first telescopic frame, the first telescopic frame forms rolling contact with the guide part through rolling elements when it rises and falls with the baffle, reducing the sliding friction between the first telescopic frame and the first fixed frame, and reducing the swaying, wobble, and jamming of the baffle during the rising and falling process. In the limit track type guide structure, the front roller, rear roller, and side roller respectively roll contact with different guide surfaces of the limit track, which can constrain the first telescopic frame from multiple directions. In the cradle type guide structure, the cradle can swing slightly relative to the base and is elastically constrained by the elastic return component, thereby adapting to positional deviations caused by off-center loading, assembly gaps, or frame deformation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. 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 adjustable lifting platform anti-foot-pressing device of the present invention.

[0020] Figure 2 This is a front view structural schematic diagram of the adjustable lifting operation vehicle rear platform lifting anti-foot-pressing device of the present invention.

[0021] Figure 3 This is a schematic diagram of the adjustable lifting operation vehicle with rear platform lifting anti-foot-pressing device according to the present invention.

[0022] Figure 4 This is a schematic diagram of the limiting track-type guide component of the adjustable lifting operation vehicle rear platform lifting anti-foot-pressing device of the present invention.

[0023] Figure 5 This is a schematic diagram showing the cooperation between the limiting rail and the rolling element of the adjustable lifting platform anti-foot-pressurization device of the present invention.

[0024] Figure 6 This is a schematic diagram of the cradle-type guide component of the adjustable lifting operation vehicle rear platform lifting anti-foot-pressing device of the present invention.

[0025] Explanation of reference numerals in the attached drawings: 100, First fixed frame; 101, Guide cavity; 200, First telescopic frame; 300, Baffle; 301, Protrusion; 400, Guide component; 401, Guide part; 401a, Limiting track; 402, Follow-up support part; 402a, Base; 402b, Rolling component; 402c, Cradle; 402d, Elastic return assembly; 402d1, Pressure rod; 402d2, Box body; 402d3, Elastic pressure block; 402d4, Slide groove; 402e, Sliding column; 500, Lifting platform; 600, Elastic reset component; 700, Second fixed frame; 800, Second telescopic frame; 900, Working vehicle. Detailed Implementation

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0027] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0028] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0029] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0030] Example 1

[0031] Reference Figures 1-3 The first embodiment of the present invention provides an adjustable lifting platform anti-foot-crushing device for a lifting work vehicle. This device includes a first fixed frame 100, which is fixedly installed below the rear of the work vehicle 900; and a first telescopic frame 200, which is slidably connected to the first fixed frame 100.

[0032] The first fixed frame 100 serves as the reference component for the entire anti-foot-pressing device and is fixedly installed under the chassis at the rear of the work vehicle 900 by bolting or welding. Its installation position must avoid the original vehicle structure to ensure sufficient space for the subsequent vertical sliding of the first telescopic frame 200.

[0033] The baffle 300 is fixedly connected to the first telescopic frame 200 at both ends and is used to block the gap between the lifting platform 500 and the rear of the work vehicle 900. The bottom of the baffle 300 is provided with a protrusion 301, which is in contact with the lower surface of the lifting platform 500.

[0034] Both ends of the baffle 300 are rigidly connected to the first telescopic frame 200, and rise and fall synchronously with the first telescopic frame 200 within the first fixed frame 100, ensuring that it is always positioned in the gap between the lifting platform 500 and the rear of the work vehicle 900. A protrusion 301 is integrally formed or fixedly provided at the bottom of the baffle 300. This protrusion 301 extends laterally into the running trajectory of the lifting platform 500 and directly contacts its lower surface. Because it is a movable contact rather than a fixed connection, it allows the two to separate during a specific stroke.

[0035] The elastic reset member 600 has its two ends connected to the first fixed frame 100 and the baffle 300, respectively. The elastic reset member 600 is in a pre-stretched state, and the protrusion 301 always tends to stick to the lifting platform 500 upward through the tension.

[0036] In this embodiment, the elastic reset member 600 is preferably a high-strength tension spring, with its top end connected to the top of the first fixed frame 100 and its bottom end connected to the baffle 300. In the initial installation state, the elastic reset member 600 is in a pre-stretched state, generating a continuous upward pulling force. This pulling force is sufficient to overcome the weight and friction of the baffle 300 and the first telescopic frame 200, ensuring that the protrusion 301 remains firmly attached to the lower surface of the lifting platform 500.

[0037] The work vehicle 900 is equipped with a second fixed frame 700 at its rear, which is slidably connected to a second telescopic frame 800. The lifting platform 500 is fixedly connected to the bottom of the second telescopic frame 800. The work vehicle 900 originally had a second fixed frame 700 and a second telescopic frame 800 at its rear to support the lifting of the main body of the lifting platform 500. The lifting of the lifting platform 500 can be achieved using the vehicle's own slings or other lifting methods, which will not be elaborated upon here. The first fixed frame 100 and the first telescopic frame 200 are arranged independently of the second fixed frame 700 and the second telescopic frame 800 to guide the movement of the anti-pinch baffle 300 and avoid interference with the main load-bearing structure.

[0038] Reference Figure 2The lifting stroke L1 of the baffle 300 is less than the lifting stroke L2 of the lifting platform 500. L1 is the maximum vertical displacement of the baffle 300 relative to the first fixed frame 100, and L2 is the total lifting displacement of the lifting platform 500 relative to the rear of the work vehicle 900. When the lifting platform 500 moves upward to the limit stop where the baffle 300 and the top of the first fixed frame 100 meet, the baffle 300 stops moving, the lifting platform 500 disengages from the protrusion 301 and continues to move upward.

[0039] When the lifting platform 500 descends, the bottom surface of the platform forces the baffle 300 downward by pressing against the protrusion 301. At this time, the elastic reset member 600 is further stretched and stores energy, and the baffle 300 effectively prevents personnel's feet from accidentally entering the gap under the platform. When the lifting platform 500 rises, the elastic reset member 600 releases its tension, pulling the baffle 300 to rise synchronously with the platform. When the baffle 300 rises to the end of its stroke L1, that is, when its top abuts against the limiting top of the first fixed frame 100, the baffle 300 stops moving and completely seals the gap. Since the stroke L2 of the lifting platform 500 is longer, after the baffle 300 stops, the lifting platform 500 continues to rise and disengages from the protrusion 301 until it is flush with the rear floor of the work vehicle 900. This design ensures that the gap remains closed during the final stage of the platform's ascent, achieving full-stroke anti-pinch and anti-compression protection, and the baffle 300 does not affect the lifting of the lifting platform 500.

[0040] Example 2

[0041] Reference Figure 4 and Figure 5 This is a second embodiment of the present invention, which differs from the first embodiment in that: the first fixed frame 100 forms a guide cavity 101 into which the first telescopic frame 200 at least partially extends and slides vertically and vertically. The guide cavity 101 is surrounded by three side walls of the first fixed frame 100, and has an opening extending in the vertical direction in the direction facing the outer side of the first telescopic frame 200. A portion of the first telescopic frame 200 extends into the guide cavity 101 through the opening and is able to slide vertically and vertically relative to the first fixed frame 100 along the guide cavity 101.

[0042] A guide member 400 is provided between the first fixed frame 100 and the first telescopic frame 200. The guide member 400 includes a guide portion 401 and a follower support portion 402. The guide portion 401 is provided on the first fixed frame 100 and extends along the lifting direction of the baffle 300. The follower support portion 402 includes a base 402a provided on the outer side of the first telescopic frame 200. The follower support portion 402 moves up and down with the first telescopic frame 200 and is provided with a rolling member 402b that rolls in contact with the guide portion 401.

[0043] The guide portion 401 is a limiting rail 401a that protrudes from the inner wall of the first fixed frame 100 toward the first telescopic frame 200, and the limiting rail 401a extends in the vertical direction. The limiting rail 401a serves as a guide reference during the lifting and lowering process of the first telescopic frame 200, and it is provided to protrude relative to the inner wall of the first fixed frame 100 so that the rolling element 402b can form a rolling limiting engagement with it from multiple directions.

[0044] Specifically, the first fixed frame 100 can be a frame-like component extending in the vertical direction, with a cross-section that is approximately a groove-shaped structure with an opening on one side. The three sidewalls of the first fixed frame 100 together form a guide cavity 101, which is used to accommodate at least a portion of the first telescopic frame 200, allowing the first telescopic frame 200 to slide vertically within the guide cavity 101. The opening is located on the side of the first fixed frame 100 facing the outer side of the first telescopic frame 200 and extends along the lifting direction of the first telescopic frame 200, allowing the first telescopic frame 200 to extend into the guide cavity 101 from this opening. A guide member 400 is disposed between the first fixed frame 100 and the first telescopic frame 200 to provide rolling guidance when the two move relative to each other. The guide portion 401 is fixed or integrally formed on the first fixed frame 100, and its length direction is consistent with the lifting direction of the baffle 300 and the first telescopic frame 200; the follower support portion 402 is disposed on the outer side of the first telescopic frame 200 and moves synchronously with the first telescopic frame 200. The base 402a serves as the mounting base for the follower support 402 and is used to mount the rolling element 402b. The rolling element 402b maintains rolling contact with the guide 401, so that when the first telescopic frame 200 moves up and down relative to the first fixed frame 100, the sliding fit is converted into at least a partial rolling fit.

[0045] The base 402a is a clamping base, forming a holding cavity surrounding the outer periphery of the limiting track 401a, and has a front support and a rear support located on the front and rear sides of the limiting track 401a respectively, as well as a lateral support located on the side of the limiting track 401a facing the first telescopic frame 200.

[0046] Thus, the base 402a forms an enveloping fit with the limiting track 401a in cross-section, so that the first telescopic frame 200 can be constrained by both the front-back and lateral directions during the lifting and lowering process.

[0047] The rolling element 402b includes a front roller, a rear roller, and a side roller respectively disposed on the front support portion, the rear support portion, and the side support portion. The front roller, the rear roller, and the side roller respectively make rolling contact with the front guide surface, the rear guide surface, and the side guide surface of the limiting track 401a.

[0048] The limiting rail 401a can be a strip-shaped convex rail extending along the height direction of the first fixed frame 100. It can be integrally formed with the first fixed frame 100, or it can be fixed to the inner wall of the first fixed frame 100 by welding, bolting, or riveting. The limiting rail 401a protrudes from the inner wall of the first fixed frame 100 toward the first telescopic frame 200, forming a raised guide structure in its cross-section that can be partially surrounded by the base 402a. The base 402a can be a clamping base, with a holding cavity formed inside or on one side facing the limiting rail 401a. The holding cavity is arranged around at least three lateral areas of the limiting rail 401a. The front support and the rear support are located on both sides of the limiting rail 401a in the longitudinal direction of the work vehicle, respectively, for mounting the front roller and the rear roller; the lateral support is located on the side of the limiting rail 401a facing the first telescopic frame 200, for mounting the lateral roller. The front roller makes rolling contact with the front guide surface of the limiting rail 401a, and the rear roller makes rolling contact with the rear guide surface of the limiting rail 401a. Together, they restrict the swinging of the first telescopic frame 200 and the baffle 300 in the forward and backward direction of the work vehicle. The lateral roller makes rolling contact with the lateral guide surface of the limiting rail 401a, which is used to restrict the first telescopic frame 200 from deviating towards the opening direction of the first fixed frame 100. The three rollers form an enveloping rolling engagement around the limiting rail 401a, so that the first telescopic frame 200 moves stably along the limiting rail 401a during the lifting and lowering process.

[0049] During use, when the lifting platform 500 moves downward and presses against the protrusion 301, the baffle 300 causes the first telescopic frame 200 to slide downward relative to the first fixed frame 100. At this time, the base 402a moves downward synchronously with the first telescopic frame 200, and the front roller, rear roller, and lateral roller roll along the corresponding guide surfaces of the limiting rail 401a. When the front roller and rear roller abut against the front and rear sides of the limiting rail 401a respectively, they can limit the swinging of the first telescopic frame 200 and the baffle 300 in the front-rear direction of the work vehicle 900; when the lateral roller abuts against the lateral guide surface of the limiting rail 401a, it can limit the first telescopic frame 200 and the baffle 300 from shifting in the opening direction.

[0050] When the lifting platform 500 moves upward, the elastic reset component 600 drives the baffle 300 and the first telescopic frame 200 to rise. At this time, the rolling component 402b continues to roll along the limiting track 401a, so that the first telescopic frame 200 remains in a guided state during the rising process, reducing the shaking of the baffle 300 caused by the uneven load of the lifting platform 500, vehicle body vibration, or assembly gaps.

[0051] Since both ends of the baffle 300 are fixedly connected to the corresponding first telescopic frames 200, the guide members 400 can be respectively set on the first telescopic frames 200 on both sides of the baffle 300. That is to say, a set of limiting rails 401a, bases 402a and rolling members 402b can be set between the first telescopic frames 200 and the first fixed frames 100 at the left and right ends of the baffle 300. The two sets of guide members 400 can be symmetrically arranged relative to the middle of the baffle 300, so that both ends of the baffle 300 are subject to rolling guidance constraint during the lifting and lowering process, avoiding twisting or unilateral deflection of the baffle 300 after being subjected to force at one end.

[0052] The base 402a is disposed in the top region of the first telescopic frame 200, that is, at one end of the first telescopic frame 200 that extends into the guide cavity 101 of the first fixed frame 100. Since the base 402a and its rolling element 402b are located in the top region of the first telescopic frame 200, when the first telescopic frame 200 moves downward, the base 402a remains in the guide cavity 101 of the first fixed frame 100, and maintains cooperation with the limiting rail 401a through the rolling element 402b, thereby preventing the first telescopic frame 200 from laterally disengaging from the opening relative to the first fixed frame 100.

[0053] A stop is provided at the lower end of the first fixed frame 100 or the lower end of the limiting track 401a. When the first telescopic frame 200 moves downward to a predetermined limit position, the base 402a or the rolling element 402b abuts against the stop to limit the first telescopic frame 200 from moving further downward, thereby further preventing the first telescopic frame 200 from detaching from the first fixed frame 100.

[0054] Through the above structure, the limiting track 401a, the base 402a, and the front, rear, and lateral rollers together form a limiting track-type rolling guide structure. This structure can form multi-directional rolling constraints on the first telescopic frame 200 when it rises and falls with the baffle 300, which reduces the sliding friction between the first telescopic frame 200 and the first fixed frame 100, and also reduces the swaying, wobble, and jamming of the baffle 300 during the rising and falling process.

[0055] The remaining structure is the same as that in Example 1.

[0056] Example 3

[0057] Reference Figure 6This is the third embodiment of the present invention, which differs from the second embodiment in that: the guide portion 401 is formed by the inner wall surface of the three side walls of the first fixed frame 100; the base 402a is a hinged support seat, which includes a mounting plate connected to the outer side surface of the first telescopic frame 200, and a hinged support portion disposed on the mounting plate, the hinged support portion being rotatably connected to a rocker arm 402c; the rolling element 402b includes three rollers disposed at the top of the rocker arm 402c, the three rollers being disposed facing the inner wall surface of the three side walls respectively, and respectively rolling contacting the corresponding inner wall surface.

[0058] In this embodiment, the inner walls of the three side walls of the first fixed frame 100 serve as guide portions 401, and no separate limiting rails are provided. The inner walls of the three side walls are located at different lateral positions of the first telescopic frame 200, forming a three-point rolling support for the three rollers at the top of the rocker arm 402c. The base 402a is a hinged support seat, and its mounting plate can be a plate-shaped component, fixedly connected to the outer side of the first telescopic frame 200; the hinged support portion can be an ear plate, a hinge seat, or a support protrusion with a shaft hole, extending from the mounting plate toward the guide cavity 101 of the first fixed frame 100. The rocker arm 402c is rotatably connected to the hinged support portion via a rotating shaft, pin, or hinge shaft, allowing the rocker arm 402c to swing at a small angle relative to the first telescopic frame 200. The three rollers are located at the top of the rocker arm 402c and face the inner walls of the three side walls of the first fixed frame 100, respectively. Three rollers roll into contact with the corresponding inner wall surfaces, causing the cradle 402c to move synchronously with the first telescopic frame 200 as it rises and falls. Simultaneously, the three rollers form a rolling support between the three inner walls. Since one side of the first fixed frame 100 is open, the cradle 402c has compensation space in that opening direction, allowing for slight oscillation when the first telescopic frame 200 is subjected to eccentric loading or assembly errors, thereby reducing the risk of rigid jamming.

[0059] An elastic return assembly 402d is provided between the rocker arm 402c and the first telescopic frame 200. The elastic return assembly 402d includes a pressure rod 402d1, a housing 402d2, and an elastic pressure block 402d3. The pressure rod 402d1 is connected to the rocker arm 402c and swings with the rocker arm 402c. The housing 402d2 is located in the first telescopic frame 200, and the elastic pressure block 402d3 is located inside the housing 402d2. The pressure rod 402d1 extends into the housing 402d2 and presses the elastic pressure block 402d3 when the rocker arm 402c swings relative to the hinged support.

[0060] An elastic return component 402d is disposed between the rocker arm 402c and the first telescopic frame 200 to provide elastic constraint to the rocker arm 402c when it swings. The pressure rod 402d1 can be an arc-shaped rod, a bent rod, or a rod-shaped member with an arc-shaped motion trajectory; one end is connected to the rocker arm 402c, and the other end extends into the housing 402d2. As the rocker arm 402c swings around the hinged support, the pressure rod 402d1 swings synchronously with the rocker arm 402c, and its end extending into the housing 402d2 is displaced within the housing 402d2. The housing 402d2 can be a hollow box-shaped member fixed to the outer side of the first telescopic frame 200, with an internal space for the pressure rod 402d1 to extend into and swing. An elastic pressure block 402d3 is disposed within the housing 402d2 and located on the movement path of the pressure rod 402d1. The elastic pressure block 402d3 can be made of rubber, polyurethane, elastic rubber, or elastic composite material. When the rocker arm 402c swings relative to the hinged support, the pressure rod 402d1 presses against the elastic pressure block 402d3, causing the elastic pressure block 402d3 to undergo elastic deformation and provide reverse support to the pressure rod 402d1, thereby limiting the rocker arm 402c from continuing to swing and assisting the rocker arm 402c in returning to its initial posture.

[0061] The pressure rod 402d1 has a sliding groove 402d4. The pressure rod 402d1 has a sliding column 402e and an internal spring. The sliding column 402e is slidably arranged along the sliding groove 402d4. One end of the internal spring abuts against the pressure rod 402d1, and the other end abuts against the sliding column 402e. The sliding column 402e has an abutting end facing the inner wall of the box 402d2. The abutting end of the sliding column 402e extends out of the pressure rod 402d1 through the sliding groove 402d4. When the swing amplitude of the rocker arm 402c increases, the inner wall of the box 402d2 presses against the abutting end, causing the sliding column 402e to move along the sliding groove 402d4 and compress the internal spring.

[0062] The pressure rod 402d1 can be a rod-shaped structure with an internal receiving cavity. A groove 402d4 is formed along the length of the pressure rod 402d1 or along the moving direction of the sliding column 402e. The sliding column 402e is disposed inside the pressure rod 402d1 and can slide relative to the pressure rod 402d1 along the groove 402d4. The abutting end of the sliding column 402e extends out of the pressure rod 402d1 through the groove 402d4 and faces the inner wall of the housing 402d2. An internal spring is disposed inside the pressure rod 402d1, with one end abutting against the inner wall, limiting step, or spring seat of the pressure rod 402d1, and the other end abutting against the sliding column 402e. When the rocker arm 402c swings slightly, the pressure rod 402d1 mainly presses against the elastic pressure block 402d3, which provides flexible support. When the swing amplitude of the rocker arm 402c increases, the abutting end of the sliding column 402e contacts and is compressed against the inner wall of the housing 402d2. The sliding column 402e moves along the slide groove 402d4 into the pressure rod 402d1, while compressing the internal spring. Thus, the elastic pressure block 402d3 and the internal spring form a graded elastic fit: the elastic pressure block 402d3 is used to compensate for displacement during small swings, and the internal spring is used to provide further buffering and limiting support when the swing amplitude increases.

[0063] There are two sets of elastic return components 402d, which are respectively located on both sides of the rocker 402c. When the rocker 402c swings to one side, the pressure rod 402d1 of one set of elastic return components 402d presses the corresponding elastic pressure block 402d3. When the rocker 402c swings to the other side, the pressure rod 402d1 of the other set of elastic return components 402d presses the corresponding elastic pressure block 402d3.

[0064] Two sets of elastic return components 402d are respectively disposed on both sides of the rocker arm 402c. When the rocker arm 402c swings to one side, the pressure rod 402d1 on that side presses against the corresponding elastic pressure block 402d3; when the rocker arm 402c swings to the other side, the pressure rod 402d1 on the other side presses against the corresponding elastic pressure block 402d3. Thus, no matter which direction the rocker arm 402c swings, the elastic return component 402d on the corresponding side can form an elastic constraint, reducing the swaying of the first telescopic frame 200 and the baffle 300 during the lifting and lowering process.

[0065] Two sets of elastic return components 402d are symmetrically arranged relative to the swing center of the rocker arm 402c. Each set of elastic return components 402d includes a pressure rod 402d1, a housing 402d2, and an elastic pressure block 402d3, and the pressure rod 402d1 of each set of elastic return components 402d is connected to the corresponding side of the rocker arm 402c. The two housings 402d2 are fixed to corresponding positions on the outer side of the first telescopic frame 200, so that the pressure rods 402d1 on both sides can extend into the corresponding housings 402d2. When the rocker arm 402c swings to one side, the pressure rod 402d1 on that side further displaces into the corresponding housing 402d2 and presses the corresponding elastic pressure block 402d3; when the rocker arm 402c swings in the opposite direction, the pressure rod 402d1 on the other side presses the other set of elastic pressure blocks 402d3. Through the alternating compression of the elastic return components 402d on both sides, the cradle 402c can be elastically constrained in both opposite swing directions, avoiding the problem of insufficient compensation in one direction when only one side is equipped with an elastic structure. This arrangement on both sides can also make the force on the cradle 402c more balanced, reducing the unilateral tilt of the first telescopic frame 200 and the baffle 300 during the lifting and lowering process.

[0066] During use, when the baffle 300 causes the first telescopic frame 200 to rise and fall relative to the first fixed frame 100, the base 402a moves synchronously with the first telescopic frame 200, and the rocker arm 402c rolls against the inner walls of the three side walls of the first fixed frame 100 via three rollers at its top. Because the three rollers are positioned facing three different inner wall surfaces, the rocker arm 402c can obtain rolling support in three directions during the rising and falling process, so that the first telescopic frame 200 no longer relies solely on the inner wall of the first fixed frame 100 for sliding friction guidance.

[0067] When the baffle 300 moves downward under the pressure of the lifting platform 500, if the force exerted by the lifting platform 500 on the protrusion 301 is uneven, or if there is an assembly gap between the first fixed frame 100 and the first telescopic frame 200, the first telescopic frame 200 may become slightly tilted. At this time, the cradle 402c can swing at a small angle relative to the hinged support, and the three rollers roll along the corresponding inner wall surfaces to adjust the contact position, thereby allowing the cradle 402c to adapt to the slight positional deviation between the first telescopic frame 200 and the first fixed frame 100.

[0068] Because the first fixed frame 100 forms an opening in the direction facing the outer side of the first telescopic frame 200, the cradle 402c has a certain compensation space in the direction of the opening. This structure avoids the first fixed frame 100 forming a rigid four-sided closed constraint on the cradle 402c, allowing the cradle 402c to adaptively adjust by swinging when subjected to eccentric load, reducing the risk of jamming of the first telescopic frame 200 during the lifting and lowering process.

[0069] When the rocker arm 402c swings slightly, the pressure rod 402d1 connected to the rocker arm 402c swings synchronously with the rocker arm 402c and extends into the housing 402d2. The pressure rod 402d1 presses against the elastic pressure block 402d3 inside the housing 402d2. After being compressed, the elastic pressure block 402d3 undergoes elastic deformation, thereby providing reverse support to the pressure rod 402d1, causing the rocker arm 402c to tend to return to its initial position.

[0070] When the swing amplitude of the rocker arm 402c increases further, the elastic deformation provided by the elastic pressure block 402d3 alone may be insufficient to absorb the large off-center load impact. At this time, the end of the sliding column 402e that abuts against the inner wall of the housing 402d2 is pressed by the inner wall of the housing 402d2, and the sliding column 402e slides relative to the pressure rod 402d1 along the slide groove 402d4, compressing the internal spring. Thus, the pressure rod 402d1 not only obtains the first stage of elastic support through the elastic pressure block 402d3, but also obtains the second stage of elastic buffering through the sliding column 402e and the internal spring.

[0071] Through the above-described coordination, when the cradle 402c swings slightly, the elastic pressure block 402d3 can provide a relatively gentle compensation effect; when the cradle 402c swings more significantly, the internal spring further participates in compression, thereby improving the support strength of the cradle 402c. This structure can provide graded buffering and return constraint on the sway of the first telescopic frame 200 without rigidly locking the cradle 402c.

[0072] The remaining structure is the same as that in Example 1.

[0073] Example 4

[0074] This embodiment also provides a working method for an adjustable lifting platform anti-foot-pressing device for a lifting work vehicle. The adjustable lifting platform anti-foot-pressing device for a lifting work vehicle in the above embodiment includes the following: when the lifting platform 500 is moving downward, its lower surface presses against the protrusion 301 to overcome the tension of the elastic reset member 600, thereby driving the baffle 300 and the first telescopic frame 200 to move downward. When the lifting platform 500 moves upward, the elastic reset member 600 releases the tension, causing the baffle 300 to move upward synchronously to block the gap; when the baffle 300 rises to the point where it is limited by the top of the first fixed frame 100, the baffle 300 stops moving, the lifting platform 500 disengages from the protrusion 301 and continues to rise until the predetermined position.

[0075] Specifically, when the lifting platform 500 of the work vehicle receives a descent command and begins its downward movement, the lower surface of the lifting platform 500 contacts and presses against the protrusion 301 at the bottom of the baffle 300. Since the protrusion 301 only makes movable contact with the lower surface of the platform, the downward movement of the lifting platform 500 directly overcomes the upward pulling force of the elastic reset member 600, forcibly pushing the baffle 300 and the first telescopic frame 200 fixedly connected to it to move downward synchronously.

[0076] During the movement, the baffle 300 is always located at the dynamic gap between the lifting platform 500 and the rear of the work vehicle 900, forming a moving barrier to prevent personnel's feet or foreign objects from entering under the platform.

[0077] As the lifting platform 500 moves upward from its low position back up, the downward pressure on the protrusion 301 gradually decreases as the lifting platform 500 rises. At this time, the elastic reset member 600, which is in a pre-stretched state, begins to release its elastic potential energy, generating an upward pulling force that drives the baffle 300 and the first telescopic frame 200 to rise upward in tandem with the lifting platform 500.

[0078] When the device approaches the height of the rear of the work vehicle, as the baffle 300 rises to the top of the first fixed frame 100, i.e., the end of the rising stroke L1, the upper edge of the baffle 300 abuts against the limiting end of the frame and forcibly stops its movement. Since the total rising stroke L2 of the lifting platform 500 is greater than L1, the lifting platform 500 continues to move upward after the baffle 300 is limited. At this time, the lower surface of the lifting platform 500 naturally disengages from the protrusion 301 and a displacement difference is generated. This continues until the lifting platform 500 rises to the predetermined position flush with the floor of the work vehicle. During this stage, the baffle 300 has been locked in the highest position in advance, achieving complete sealing of the dangerous gap in advance and preventing personnel injury accidents at the last moment when the platform is flush.

[0079] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise changed, and the nature or number or position of discrete elements may be altered or changed. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. Therefore, the invention is not limited to the particular embodiments but extends to a variety of modifications that still fall within the scope of the appended claims.

[0080] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the currently considered best mode for carrying out the invention, or those features that are not relevant to implementing the invention) may be omitted.

[0081] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An adjustable lift truck rear platform lift anti-heeling device characterized by: include, The first fixed frame (100) is fixedly installed below the rear of the work vehicle (900); The first telescopic frame (200) is slidably connected to the first fixed frame (100); The baffle (300) is fixedly connected to the first telescopic frame (200) at both ends and is used to block the gap between the lifting platform (500) and the rear of the work vehicle (900); the bottom of the baffle (300) is provided with a protrusion (301), and the protrusion (301) is in movable contact with the lower surface of the lifting platform (500); The elastic reset member (600) has its two ends connected to the first fixed frame (100) and the baffle (300) respectively; the elastic reset member (600) is in a pre-stretched state, and the protrusion (301) always tends to stick to the lifting platform (500) upward by the tension. The first fixed frame (100) forms a guide cavity (101) into which the first telescopic frame (200) extends at least partially and slides up and down. The guide cavity (101) is surrounded by three side walls of the first fixed frame (100) and has an opening extending in the lifting direction in the direction toward the outer side of the first telescopic frame (200). A guide (400) is provided between the first fixed frame (100) and the first telescopic frame (200). The guide (400) includes a guide portion (401) and a follower support portion (402). The guide portion (401) is provided on the first fixed frame (100) and extends along the lifting direction of the baffle (300). The follower support portion (402) includes a base (402a) provided on the outer side of the first telescopic frame (200). The follower support portion (402) moves up and down with the first telescopic frame (200) and is provided with a rolling element (402b) that rolls in contact with the guide portion (401).

2. The adjustable lift truck rear platform lift anti-heeling device of claim 1 wherein: The rear of the work vehicle (900) is also provided with a second fixed frame (700), and the second fixed frame (700) is slidably connected to a second telescopic frame (800); the lifting platform (500) is fixedly connected to the bottom of the second telescopic frame (800).

3. The adjustable lift truck rear platform lift anti-heeling device of claim 2 wherein: The upward stroke L1 of the baffle (300) is less than the upward stroke L2 of the lifting platform (500); when the lifting platform (500) moves upward to the point where the baffle (300) abuts against the top of the first fixed frame (100), the baffle (300) stops moving, the lifting platform (500) disengages from the protrusion (301) and continues to move upward.

4. The adjustable lift truck rear platform lift anti-heeling device of claim 3 wherein: The guide part (401) is a limiting track (401a) that protrudes from the inner sidewall of the first fixed frame (100) toward the first telescopic frame (200), and the limiting track (401a) extends in the vertical direction. The base (402a) forms a holding cavity surrounding the outer periphery of the limiting track (401a), and has a front support portion and a rear support portion located on the front and rear sides of the limiting track (401a) respectively, as well as a lateral support portion located on the side of the limiting track (401a) facing the first telescopic frame (200). The rolling element (402b) includes a front roller, a rear roller, and a lateral roller respectively disposed on the front support portion, the rear support portion, and the lateral support portion. The front roller, the rear roller, and the lateral roller respectively make rolling contact with the front guide surface, the rear guide surface, and the lateral guide surface of the limiting track (401a).

5. The adjustable lift truck rear platform lift anti-heeling device as set forth in any of claims 1-3, wherein: The guide portion (401) is formed by the inner wall surface of the three side walls of the first fixed frame (100); The base (402a) is a hinged support, which includes a mounting plate connected to the outer side of the first telescopic frame (200) and a hinged support portion disposed on the mounting plate. The hinged support portion is rotatably connected to a rocker arm (402c). The rolling element (402b) includes three rollers disposed at the top of the rocker arm (402c). The three rollers are respectively disposed facing the inner wall surface of the three side walls and respectively rolling contact with the corresponding inner wall surface.

6. The adjustable lift truck rear platform lift anti-heeling device of claim 5 wherein: An elastic return assembly (402d) is provided between the rocker arm (402c) and the first telescopic frame (200). The elastic return assembly (402d) includes a pressure rod (402d1), a box body (402d2), and an elastic pressure block (402d3). The pressure rod (402d1) is connected to the rocker arm (402c) and swings with the rocker arm (402c). The box body (402d2) is located in the first telescopic frame (200), and the elastic pressure block (402d3) is located inside the box body (402d2). The pressure bar (402d1) extends into the housing (402d2) and presses against the elastic block (402d3) when the rocker arm (402c) swings relative to the hinged support.

7. The adjustable lift truck rear platform lift anti-heeling device of claim 6 wherein: The pressure rod (402d1) is provided with a sliding groove (402d4), and a sliding column (402e) and an internal spring are provided inside the pressure rod (402d1). The sliding column (402e) is slidably arranged along the sliding groove (402d4). One end of the internal spring abuts against the pressure rod (402d1), and the other end abuts against the sliding column (402e). The sliding column (402e) has an abutting end facing the inner wall of the box (402d2). The abutting end of the sliding column (402e) extends out of the pressure rod (402d1) through the slide groove (402d4). When the swing amplitude of the rocker arm (402c) increases, the inner wall of the box (402d2) presses against the abutting end, causing the sliding column (402e) to move along the slide groove (402d4) and compress the internal spring.

8. The adjustable lift truck rear platform lift anti-heeling device of claims 6 or 7 wherein: The elastic return assembly (402d) consists of two sets, which are respectively located on both sides of the cradle (402c); When the rocker arm (402c) swings to one side, the pressure rod (402d1) of one set of elastic return components (402d) presses the corresponding elastic block (402d3). When the rocker arm (402c) swings to the other side, the pressure rod (402d1) of the other set of elastic return components (402d) presses the corresponding elastic block (402d3).

9. A method for operating an adjustable lifting platform anti-foot-damaging device for a lifting work vehicle, applicable to the adjustable lifting platform anti-foot-damaging device for a lifting work vehicle according to any one of claims 1 to 8, characterized in that: include, When the lifting platform (500) moves downward, its lower surface presses against the protrusion (301), overcoming the tension of the elastic reset member (600), and causing the baffle (300) and the first telescopic frame (200) to move downward. When the lifting platform (500) moves upward, the elastic reset member (600) releases the tension, causing the baffle (300) to move upward synchronously to block the gap; when the baffle (300) rises to the limit at the top of the first fixed frame (100), the baffle (300) stops moving, the lifting platform (500) disengages from the protrusion (301) and continues to rise until the predetermined position.

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