Foldable stretcher tracked vehicle

Abstract

The utility model provides a kind of foldable stretcher tracked vehicle, belong to tracked vehicle technical field, this foldable stretcher tracked vehicle includes frame, chassis drive unit and wounded support element, the frame is made of two parallelly arranged scissors longitudinal rods, longitudinal rod adopts multiple groups of articulated lever segment to form parallelogram zoom mechanism, and each group of section contains mutually crossed articulated cover lever and holding lever;Two longitudinal rods are rigidly connected by tubular cross bracing, tubular cross bracing is evenly distributed along longitudinal rod length direction, lateral spacing and longitudinal rod width are adapted;The chassis drive unit is tracked structure, includes two pairs of wheel edge motor and track, wheel edge motor is respectively arranged in the hub outside of wheel, is connected by speed reducer and track drive wheel, track is wound in motor drive wheel outside;The both ends of the scissors longitudinal rod are respectively equipped with folding locking support, solve the problem of traditional foldable stretcher tracked vehicle in frame folding efficiency, track drive and frame linkage.

Description

Technical Field

[0001] This utility model belongs to the field of tracked vehicle technology, and more specifically, relates to a foldable stretcher tracked vehicle. Background Technology

[0002] Foldable stretcher tracked vehicles are specialized transport equipment designed for medical evacuation and emergency rescue scenarios. Their core function is to achieve a balance between mobility, compactness, and terrain adaptability in patient transport through a combination of a foldable frame structure and a tracked drive system. This type of equipment is particularly suitable for military medical evacuation, natural disaster relief, and field emergency medical services. When traditional wheeled stretchers are limited by rugged terrain, or fixed tracked vehicles are too bulky for rapid deployment, the foldable design allows for compact transport to the scene (e.g., fitting into a helicopter or off-road vehicle). Once unfolded, the high mobility of the tracks enables patient transfer across complex terrain.

[0003] Existing equipment of this type generally suffers from the following defects: Some designs use multi-segment articulated longitudinal bars, which, although adjustable in length, have more than 20 articulation points, requiring segment-by-segment operation during folding and taking more than 2 minutes to unfold, failing to meet the timeliness requirements of emergency rescue. Furthermore, numerous articulated components are prone to wear and tear, causing the frame to sway under load and even exhibit a "nodding" phenomenon (i.e., the front end of the longitudinal bar droops), increasing the risk of secondary injury to the injured. Traditional designs often use all-metal frames to improve rigidity, but the curb weight exceeds 80kg, making manual handling difficult. Using lightweight materials (such as aluminum alloy) requires sacrificing structural strength, causing the frame to undergo plastic deformation when traveling on rough terrain, failing tests on slopes exceeding 15°. Some equipment uses a single pin locking mechanism; when the tracks vibrate, the pin can easily loosen due to impact, causing the frame to unexpectedly contract. In one test case, when the equipment traversed a gravel road, the locking pin popped out due to vibration, causing the frame to instantly contract by 30% of its length, simulating a fall by an injured person. Traditional tracked vehicles require manual adjustment of the tension screw using a wrench. The tension must be recalibrated after each folding / unfolding, and each adjustment takes about 5 minutes. If the tension is insufficient, the tracks are prone to slipping; if the tension is too high, it will accelerate the wear of the drive wheels and tracks, shortening their service life. Utility Model Content

[0004] In view of this, the present invention provides a foldable stretcher tracked vehicle that solves the problems of traditional foldable stretcher tracked vehicles in terms of frame folding and unfolding efficiency and track drive and frame linkage, so as to realize the needs of compact and portable equipment, quick switching of state and adaptability to complex terrain for transporting the wounded.

[0005] This utility model is implemented as follows:

[0006] This utility model provides a foldable stretcher tracked vehicle, including a frame, a chassis drive unit, and a casualty support element, wherein:

[0007] The frame consists of two parallel scissor-type longitudinal bars. The longitudinal bars form a parallelogram scaling mechanism using multiple sets of hinged lever segments. Each set of segments includes a covering lever and a holding lever that are hinged to each other.

[0008] The two longitudinal bars are rigidly connected by tubular transverse bracing, which are evenly distributed along the length of the longitudinal bars, with the transverse spacing matching the width of the longitudinal bars.

[0009] The chassis drive unit is a tracked structure, which includes two pairs of wheel-side motors and tracks. The wheel-side motors are respectively located on the outside of the wheel hubs and connected to the track drive wheels through reducers. The tracks are wrapped around the outside of the motor drive wheels.

[0010] It also includes a control cabin, which houses a 2.2kWh battery pack and a wireless remote control module with a remote control distance of 100m, supporting remote control of driving speed (up to 5km / h) and steering. The control cabin is integrated into a hollow tubular support in the middle of the frame, housing the battery, motor controller, and wireless remote control module, with the remote control antenna extending from the end of the support.

[0011] Based on the above technical solution, the foldable stretcher tracked vehicle of this utility model can be further improved as follows:

[0012] The scissor-type longitudinal bar is provided with folding locking brackets at both ends. The folding locking brackets are connected to the ends of the longitudinal bar through hinge shafts. When unfolded, they vertically support the longitudinal bar, and when folded, they fit against the side of the longitudinal bar.

[0013] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: when the support is unfolded, it is at a 90° angle to the longitudinal bar (similar to a tripod structure), and physical limits prevent the frame from expanding excessively, ensuring the stability when the injured person is supported; when folded, the support is thin (e.g., ≤50cm), avoiding protrusion from the frame surface and causing scratches during handling, while also reducing the space occupied during storage.

[0014] Furthermore, the inner surface of the track is provided with a limiting pin, the track drive wheel is fitted on the outside of the wheel hub, the wheel-side motor drives the track to rotate around the drive wheel through a reducer, and the outer surface of the drive wheel is provided with trapezoidal tooth grooves that mesh with the limiting pins on the inner surface of the track for transmission.

[0015] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the limiting pins and the tooth grooves form a rigid engagement, which can increase the driving force by more than 30% compared with smooth tracks, and is especially suitable for climbing slopes or wet and slippery roads; the limiting pins are evenly distributed along the length of the track, which can guide the track to move along the axis of the drive wheel and avoid lateral deviation that could lead to derailment.

[0016] Furthermore, the wheel-side motor shaft also serves as the hinge shaft for the longitudinal rod segment. The motor housing is fixed to the end of the longitudinal rod segment by bolts, and an anti-loosening nut is provided at the shaft end.

[0017] Furthermore, the track can be hidden in a storage slot at the bottom of the frame. The storage slot is located below the longitudinal bar. The width of the storage slot is adapted to the width of the track. In the hidden state, the top surface of the track is in contact with the bottom surface of the storage slot. The grounding end of the track is provided with anti-slip teeth. The direction of the anti-slip teeth is perpendicular to the direction of travel. The track tension is adjusted by the adjusting screw at the end of the motor shaft.

[0018] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: when moving, the tracks are exposed to contact the ground, providing high passability; when stationary, they are hidden in the groove, reducing track wear and making the bottom flat, which is convenient for pushing on smooth indoor surfaces; the edge of the storage groove is higher than the outer surface of the track, which can prevent the injured limbs or foreign objects from being caught in the track.

[0019] Furthermore, a wing-shaped locking plate is provided in the middle of the frame. The locking plate is sleeved on the outside of the hinge screw of the longitudinal rod through a slot. The shape of the slot matches the head of the screw. The locking plate is fixed to the longitudinal rod by a spring buckle.

[0020] The beneficial effects of adopting the above-mentioned improved scheme are as follows: Compared with a single folding bracket, the airfoil locking plate simultaneously fixes the longitudinal rod segments both longitudinally (bracket) and laterally (locking plate), preventing the frame from accidentally unfolding during transportation. The airfoil locking plate refers to a slotted locking plate that engages with irregularly shaped screws and has a shape similar to an aircraft wing.

[0021] Furthermore, both ends of the tubular transverse support are inserted into the sleeve-type interface on the side of the longitudinal rod, and positioning pin holes are set inside the interface. The tubular transverse support is fixedly connected to the longitudinal rod by the pins.

[0022] Furthermore, the wheel-side motors of the chassis drive unit are arranged symmetrically, with the two wheel-side motors at the bottom of each longitudinal rod located at the front and rear hinge nodes of the longitudinal rod, respectively, forming a four-wheel drive structure.

[0023] Furthermore, when the frame is folded, the longitudinal segments contract in an accordion-like manner, and the tubular transverse bracing moves synchronously with the longitudinal segments. After folding, the length of the longitudinal segments is less than 1 / 2 of the unfolded length.

[0024] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the transverse support moves synchronously with the longitudinal rod segment, avoiding the "linkage lag" problem of the traditional folding structure and shortening the frame unfolding time; after folding, it takes the shape of a cuboid, which is convenient for standardized warehousing or multi-layer stacking transportation.

[0025] Furthermore, the casualty support element is made of flexible fabric and is fixed to the top of the longitudinal bar by Velcro or buckles. The fabric has load-bearing straps on both sides, and the load-bearing straps correspond to the hinge nodes of the longitudinal bar.

[0026] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the flexible fabric can bend with the frame folding, avoiding the crease damage of traditional rigid stretchers, and at the same time, it can be quickly disassembled and assembled with Velcro, which is convenient for disinfection or replacement; the load-bearing belt corresponds to the hinge node of the longitudinal bar (such as being located in the middle of the lever segment), so that the weight of the injured person is distributed to the longitudinal bar through the node, reducing the concentration of single-point load.

[0027] Compared with the prior art, the beneficial effects of the foldable stretcher tracked vehicle provided by this utility model are:

[0028] The frame employs a scissor-type longitudinal bar structure, forming a parallelogram scaling mechanism through multiple sets of hinged lever segments, allowing for rapid switching between working and folded states. When folded, its volume is significantly reduced, facilitating rapid deployment to rescue sites via vehicles, helicopters, and other transport vehicles. When unfolded, the frame connects the longitudinal bars via transverse rigid supports, forming a stable load-bearing structure capable of reliably carrying the injured. Foldable supports at the ends of the longitudinal bars provide vertical support during unfolding, forming a mechanical stop to prevent excessive expansion of the frame. A wing-shaped locking plate in the middle of the frame, in conjunction with hinged screws, locks the longitudinal bar segments, preventing the frame from loosening due to vibrations during transport. This dual locking mechanism ensures the frame maintains rigidity during load-bearing and movement, enhancing the safety of transporting the injured. The frame uses tubular transverse support rigidly connecting the longitudinal bars, combined with an optimized design of the hinged lever segments, reducing overall weight while maintaining structural strength, making the equipment easy to handle manually or move short distances independently, balancing mobility and portability in emergency rescue scenarios.

[0029] The tracks can be concealed in storage slots beneath the longitudinal bars, exposing them to the ground during movement to adapt to complex terrains (such as rough roads and snow), providing high mobility; when stationary or on smooth ground, the tracks are concealed in the slots to prevent wear and facilitate pushing, enabling flexible switching between multiple uses; wheel-side motors are mounted in pairs at the bottom of the longitudinal bars, with the motor shafts also serving as hinge shafts for the longitudinal bar segments, reducing transmission components and improving energy transfer efficiency. The integrated design of the drive unit and frame structure gives the equipment self-propelled mobility, eliminating the need for external thrust or traction, and allowing it to travel autonomously even on uneven roads.

[0030] The casualty support element is a flexible fabric fixed to the top of the longitudinal bar, which has a certain cushioning performance and can reduce the impact of bumps during transportation; the edge of the fabric is equipped with a fixing device (such as a seat belt connection point) to facilitate quick fixation of the casualty, taking into account both comfort and safety. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model 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.

[0032] Figure 1 Example diagram of a foldable stretcher tracked vehicle;

[0033] Figure 2 This is a side view of a foldable stretcher tracked vehicle;

[0034] Figure 3 A folding diagram of the frame of a foldable stretcher tracked vehicle;

[0035] The attached diagram lists the components represented by each number as follows:

[0036] 10. Frame; 11. Longitudinal bar; 12. Tubular transverse support; 20. Chassis drive unit; 21. Track; 22. Wheel-side motor; 30. Casualty support element. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0038] like Figures 1-3 The image shown is a first embodiment of a foldable stretcher tracked vehicle provided by this utility model. In this embodiment, it includes a frame 10, a chassis drive unit 20, and a casualty support element 30, wherein:

[0039] The frame 10 is composed of two parallel scissor-type longitudinal bars 11. The longitudinal bars 11 form a parallelogram scaling mechanism by using multiple sets of hinged lever segments. Each set of segments includes a covering lever and a holding lever that are hinged to each other.

[0040] Two longitudinal bars 11 are rigidly connected by tubular transverse bracing 12. The tubular transverse bracing 12 is evenly distributed along the length of the longitudinal bars 11, and the transverse spacing is adapted to the width of the longitudinal bars 11.

[0041] The chassis drive unit 20 is a tracked structure, which includes two pairs of wheel-side motors 22 and tracks 21. The wheel-side motors 22 are respectively located on the outside of the wheel hub and connected to the track drive wheel through a reducer. The tracks 21 are wrapped around the outside of the motor drive wheel.

[0042] In the above technical solution, folding locking brackets are provided at both ends of the scissor-type vertical rod 11. The folding locking brackets are connected to the ends of the vertical rod 11 through a hinge shaft. When unfolded, they vertically support the vertical rod 11, and when folded, they fit against the side of the vertical rod 11.

[0043] Transmission path: from wheel-side motor to reducer to track drive wheel and finally to track.

[0044] When unfolding the frame, manually flip the bracket to a vertical position and lock it into the slot at the end of the vertical bar; when folding, unlock the slot and press the bracket to make it fit against the side of the vertical bar.

[0045] Furthermore, in the above technical solution, the inner surface of the track 21 is provided with a limiting pin, the track drive wheel is fitted on the outside of the wheel hub, the wheel-side motor drives the track to rotate around the drive wheel through a reducer, and the outer surface of the drive wheel is provided with a trapezoidal tooth groove, which meshes with the limiting pin on the inner surface of the track 21 for transmission.

[0046] Furthermore, in the above technical solution, the wheel-side motor shaft also serves as the hinge shaft of the longitudinal rod 11 segment. The motor housing is fixed to the end of the longitudinal rod 11 segment by bolts, and an anti-loosening nut is provided at the shaft end.

[0047] Furthermore, in the above technical solution, the track 21 can be hidden in the storage groove at the bottom of the frame 10. The storage groove is located below the longitudinal rod 11. The width of the storage groove is adapted to the width of the track 21. In the hidden state, the top surface of the track 21 is in contact with the bottom surface of the storage groove. The grounding end of the track 21 is provided with anti-slip teeth. The direction of the anti-slip teeth is perpendicular to the direction of travel. The track tension is adjusted by the adjusting screw at the end of the motor shaft.

[0048] The track width should be slightly smaller than the lateral spacing of the drive wheels at the bottom of the longitudinal struts to avoid interference caused by the track protruding from the side of the frame. The storage slot is located below the longitudinal struts, and its width is equal to or slightly larger than the track width to ensure that the track can be fully embedded in the slot when folded, while avoiding track wobbling due to excessive gaps.

[0049] The storage slot can be U-shaped or grooved, with guide ramps on both sides of the slot to facilitate quick insertion or removal of the track.

[0050] The bottom of the trough is equipped with positioning protrusions, which form a longitudinal locking with the array of limiting pins on the inner surface of the track to prevent the track from moving along the length direction when it is folded up.

[0051] The trough edge is equipped with elastic limiting components (such as rubber pads) to achieve lateral fixation by squeezing the side of the track, while reducing vibration and noise.

[0052] The storage slot can be an integrated molded component (such as a metal stamping or injection molding part) at the bottom of the longitudinal bar. Its width corresponds to the hinge node position of the longitudinal bar segment, ensuring that the track retracts synchronously with the longitudinal bar when the frame is folded, thus avoiding adaptation failure due to structural misalignment.

[0053] Before folding the frame, stop the wheel-side motors through the control compartment, manually loosen the tracks, and push them into the storage slot. When unfolding, start the wheel-side motors and slightly rotate the drive wheels to allow the tracks to hang down naturally and detach from the slot.

[0054] Furthermore, in the above technical solution, a wing-shaped locking plate is provided in the middle of the frame 10. The locking plate is sleeved on the outside of the hinge screw of the longitudinal rod 11 through a slot. The shape of the slot matches the head of the screw. The locking plate is fixed to the longitudinal rod 11 by a spring buckle.

[0055] Furthermore, in the above technical solution, the two ends of the tubular cross brace 12 are respectively inserted into the sleeve-type interface on the side of the longitudinal rod 11, and the interface is equipped with a positioning pin hole. The tubular cross brace 12 is fixedly connected to the longitudinal rod 11 by the pin.

[0056] Furthermore, in the above technical solution, the wheel-side motors of the chassis drive unit 20 are arranged symmetrically, and the two wheel-side motors at the bottom of each longitudinal rod 11 are located at the front and rear hinge nodes of the longitudinal rod 11, respectively, forming a four-wheel drive structure.

[0057] Furthermore, in the above technical solution, when the frame 10 is folded, the longitudinal rod segments contract in an accordion-like manner, and the tubular transverse support 12 moves synchronously with the longitudinal rod 11. After folding, the length of the longitudinal rod 11 is less than 1 / 2 of the unfolded length.

[0058] Furthermore, in the above technical solution, the casualty support element 30 is made of flexible fabric and is fixed to the top of the longitudinal rod 11 by Velcro or buckles. The fabric has load-bearing straps on both sides, and the load-bearing straps correspond to the hinge nodes of the longitudinal rod 11.

[0059] Specifically, the principle of this utility model is as follows:

[0060] The scissor-type longitudinal bar consists of multiple sets of hinged lever segments forming a parallelogram-shaped scaling mechanism. Each set of segments is connected by a hinge axis, allowing rotation and linear movement around the connection point. When the transverse support moves to the sides, the longitudinal bar segments expand synchronously, increasing the frame length to the working state; when the transverse support moves towards the center, the longitudinal bar segments contract synchronously, folding the frame into a compact form. This structure, through the geometric characteristics of a parallelogram, ensures synchronous horizontal movement of the longitudinal bar, preventing structural twisting or jamming during folding.

[0061] The stabilizing effect of the folding bracket: In the unfolded state, the folding bracket and the longitudinal rod form a triangular support structure, which uses the principle of mechanical fulcrum to offset the longitudinal impact force on the longitudinal rod and prevent the frame from shrinking due to load.

[0062] Friction locking of the wing-shaped locking plate: The slotted locking plate engages with the head of the hinge screw, and the spring preload generates friction to prevent the longitudinal rod segments from sliding relative to each other, ensuring that the frame remains locked under vibration or impact conditions;

[0063] The wheel-side motor is mounted at the bottom of the longitudinal bar, and its shaft directly serves as the hinge shaft of the longitudinal bar segment, forming an integrated "drive-hinged" structure. When the motor is driven, the torque is directly transmitted to the track through the shaft, reducing energy loss in the intermediate transmission links; when the frame is folded / unfolded, the motor moves synchronously with the longitudinal bar segment, ensuring that the positional relationship between the track and the drive wheel is always matched.

[0064] The storage slot is located below the longitudinal bar, and its width is adapted to the track. When the frame is folded, the longitudinal bar segments contract, reducing the distance between the drive wheels. The track loosens due to elastic deformation and slides into the slot. When the frame is unfolded, the distance between the drive wheels increases, and the track is stretched to a preset tension. The limiting pins precisely mesh with the drive wheel teeth, achieving reliable transmission. This design automatically adjusts the track tension through the geometric constraints of the mechanical structure, requiring no manual intervention.

Claims

1. A foldable stretcher tracked vehicle, comprising a frame, a chassis drive unit, and a casualty support element, characterized in that: The frame consists of two parallel scissor-type longitudinal bars. The longitudinal bars form a parallelogram scaling mechanism using multiple sets of hinged lever segments. Each set of segments includes a covering lever and a holding lever that are hinged to each other. The two longitudinal bars are rigidly connected by tubular transverse bracing, which are evenly distributed along the length of the longitudinal bars, with the transverse spacing matching the width of the longitudinal bars. The chassis drive unit is a tracked structure, which includes two pairs of wheel-side motors and tracks. The wheel-side motors are respectively located on the outside of the wheel hubs and connected to the track drive wheels through reducers. The tracks are wrapped around the outside of the motor drive wheels.

2. The foldable stretcher tracked vehicle according to claim 1, characterized in that, The two ends of the scissor-type longitudinal bar are respectively provided with folding locking brackets. The folding locking brackets are connected to the ends of the longitudinal bar through hinge shafts. When unfolded, they vertically support the longitudinal bar, and when folded, they fit against the side of the longitudinal bar.

3. The foldable stretcher tracked vehicle according to claim 2, characterized in that, The inner surface of the track is provided with a limiting pin, the track drive wheel is fitted on the outside of the wheel hub, the wheel-side motor drives the track to rotate around the drive wheel through a reducer, and the outer surface of the drive wheel is provided with a trapezoidal tooth groove, which meshes with the limiting pin on the inner surface of the track for transmission.

4. A foldable stretcher tracked vehicle according to claim 3, characterized in that, The wheel-side motor shaft also serves as the hinge shaft for the longitudinal rod segment. The motor housing is fixed to the end of the longitudinal rod segment by bolts, and an anti-loosening nut is provided at the shaft end.

5. A foldable stretcher tracked vehicle according to claim 4, characterized in that, The track can be hidden in the storage slot at the bottom of the frame. The storage slot is located below the longitudinal bar. The width of the storage slot is adapted to the width of the track. In the hidden state, the top surface of the track is in contact with the bottom surface of the storage slot. The grounding end of the track is provided with anti-slip teeth. The direction of the anti-slip teeth is perpendicular to the direction of travel. The track tension is adjusted by the adjusting screw at the end of the motor shaft.

6. A foldable stretcher tracked vehicle according to claim 5, characterized in that, The frame is provided with a wing-shaped locking plate in the middle. The locking plate is sleeved on the outside of the hinge screw of the longitudinal rod through a slot. The shape of the slot matches the head of the screw. The locking plate is fixed to the longitudinal rod by a spring buckle.

7. A foldable stretcher tracked vehicle according to claim 6, characterized in that, Both ends of the tubular transverse support are inserted into the sleeve-type interface on the side of the longitudinal rod, and the interface has a positioning pin hole. The tubular transverse support is fixedly connected to the longitudinal rod by the pin.

8. A foldable stretcher tracked vehicle according to claim 7, characterized in that, The wheel-side motors of the chassis drive unit are arranged symmetrically, with the two wheel-side motors at the bottom of each longitudinal rod located at the front and rear hinge nodes of the longitudinal rod, forming a four-wheel drive structure.

9. A foldable stretcher tracked vehicle according to claim 8, characterized in that, When the frame is folded, the longitudinal segments contract in an accordion-like manner, and the tubular transverse bracing moves synchronously with the longitudinal segments. After folding, the length of the longitudinal segments is less than 1 / 2 of the unfolded length.

10. A foldable stretcher tracked vehicle according to claim 9, characterized in that, The casualty support element is made of flexible fabric and is fixed to the top of the longitudinal bar by Velcro or buckles. The fabric has load-bearing straps on both sides, and the load-bearing straps correspond to the hinge nodes of the longitudinal bar.

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