Orthopedic orthosis for reduction and fixation in orthopedics department

Abstract

The invention discloses a reduction and fixation orthopedic orthosis for the orthopedics department, and belongs to the technical field of medical instruments. Comprising a fixing plate, a placing groove is formed in the front surface of the fixing plate, a bottom plate is arranged on the lower surface of the fixing plate, a placing plate is fixedly connected to the inner side wall of the bottom plate, a connecting plate is fixedly connected to the right side of the fixing plate, a winding groove is formed in the front surface of the connecting plate, and a winding rod is arranged in the winding groove; by arranging a winding rod and a plurality of first fixing belts and cooperating with a worm and worm gear transmission structure in the adjusting mechanism, an operator only needs to rotate a rotating disc, the multiple first fixing belts can be synchronously wound through the winding rod, binding belts do not need to be sequentially tied, the wearing time is greatly shortened, in the emergency treatment scene, fixing of the limbs of a patient can be rapidly completed, and the practicability is high. The situation that treatment of other life-endangering injuries is delayed due to the tedious wearing process is avoided, and the overall treatment efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an orthopedic reduction and fixation orthosis. Background Art

[0002] In the field of orthopedic treatment, orthopedic reduction and fixation orthoses are a very important type of medical device, widely used in scenarios such as the reduction and fixation of fractures and dislocations, as well as the correction of limb deformities caused by various orthopedic diseases. Their structure usually includes components such as polymer materials, metal brackets, and straps. In actual treatment, they can apply appropriate external force to the fracture or dislocation site, helping the bone return to its normal position. During the fixation period, they can stabilize the injured area, limit improper limb movement, create favorable conditions for bone healing, and alleviate patients' pain. For limb deformities, they can also gradually reshape the limb form and improve limb function and appearance through continuous correction force. They play an irreplaceable and key role in the process of orthopedic rehabilitation.

[0003] Then, the existing orthosis requires multiple straps to be tightened in sequence, and medical staff or rescue workers need to adjust the tightness of the straps one by one. During this process, the patient's injured limb may move unnecessarily due to not being fixed in time, aggravating the injury. This cumbersome wearing process will also take up a lot of emergency time, affect the treatment of other life-threatening injuries, and reduce the overall treatment efficiency. Summary of the Invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a solution to the problem that existing orthoses require multiple straps to be tightened in sequence, the cumbersome wearing process will take up a lot of emergency time, affect the treatment of other life-threatening injuries, and reduce the overall treatment efficiency.

[0005] Technical solution: An orthopedic reduction and fixation orthosis, comprising a fixing plate, a front surface of which is provided with a placement groove, a lower surface of which is provided with a bottom plate, and an inner side wall of which is fixedly connected to the placement plate;

[0006] The right side of the fixed plate is fixedly connected to a connecting plate, a front surface of the connecting plate is provided with a winding groove, a winding rod is provided inside the winding groove, and an outer side wall of the winding rod is fixedly connected to a plurality of fixing belts 1, and a side of the plurality of fixing belts 1 away from the winding rod is fixedly connected to the left side of the front surface of the fixed plate;

[0007] An adjustment mechanism is provided on the upper surface of the connecting plate.

[0008] Furthermore, a movable groove is provided on the front surface of the connecting plate and located below the winding groove, and a sliding plate 1 is slidably connected to the inside of the movable groove, and the upper surface of the sliding plate 1 is rotatably connected to the plug rod 1 through a rotating shaft, and the lower surface of the sliding plate 1 and the inner lower surface of the movable groove are fixedly connected with a plurality of springs 1, and the inner upper surface of the winding groove is rotatably connected to the plug rod 2 through a rotating shaft, and the upper and lower surfaces of the winding rod are provided with plug interfaces, and the opposite ends of the plug rod 1 and the plug rod 2 respectively extend to the inside of the two plug interfaces.

[0009] Furthermore, the upper surface of the placement plate is provided with a plurality of through-type communicating holes, the inner left side and the inner right side of the bottom plate are provided with a plurality of through-type air inlet holes, and the upper surface of the bottom plate is provided with a plurality of fixing belts 2.

[0010] Furthermore, the adjusting mechanism includes a rotating disc, a rotating rod is fixedly connected to the center of the lower surface of the rotating disc, the bottom end of the rotating rod extends to the interior of the winding groove and is fixedly connected to a worm, the outer wall of the winding rod is fixedly connected to a worm wheel, and the outer wall of the worm wheel is meshingly connected to the outer wall of the worm.

[0011] Furthermore, a through-type vertical ventilation groove is provided on the inner rear surface of the placement groove, and a ventilation inclined groove is provided on the left side and the right side of the inner side wall of the bottom plate and above the placement plate.

[0012] Furthermore, the inner left and right sides of the movable groove are provided with limiting grooves, the left and right sides of the sliding plate 1 are fixedly connected with sliders, and the opposite sides of the two sliders are respectively slidably connected to the inner sides of the two limiting grooves.

[0013] Furthermore, a sliding cavity is integrally formed inside the connecting plate and above the winding groove, and a sliding plate 2 is slidably connected to the inside of the sliding cavity. The lower surface of the sliding plate 2 is fixedly connected to the lower surface of the interior of the sliding cavity with two springs 2, and the upper surface of the sliding plate 2 is rotatably connected to a U-shaped limiting slide rod, and a plurality of limiting circular holes are opened on the upper surface of the rotating disk, and the U-shaped limiting slide rod extends from one end of the sliding plate 2 to the inside of the limiting circular hole in front.

[0014] Furthermore, an anti-slip groove is integrally formed on the outer side wall of the rotating disc.

[0015] Beneficial Effects: By providing a reeling rod and multiple fixing straps, in conjunction with the worm and worm gear transmission structure in the adjustment mechanism, the operator only needs to rotate the rotating disk to simultaneously reel in multiple fixing straps via the reeling rod, eliminating the need to tighten the straps one by one. This significantly shortens donning time and allows for rapid fixation of the patient's limbs in emergency treatment scenarios, avoiding delays in the treatment of other life-threatening injuries due to a cumbersome donning process, thereby improving overall treatment efficiency.

[0016] Through the coordinated design of the movable slot, the first sliding plate, the first plug-in rod, the second plug-in rod, and the plug interface, the reeling rod can be quickly installed and fixed in the reeling slot, and the angle can be easily adjusted according to the patient's limb condition, ensuring that the first fixation belt can fit the limb tightly. At the same time, the self-locking nature of the worm wheel and the worm, as well as the locking effect of the U-shaped limiting slide bar on the rotating disc, can prevent the first fixation belt from loosening after being worn, ensuring the stability of the fixation effect and reducing the risk of secondary injury caused by improper fixation.

[0017] The connecting holes on the placement plate, the air inlet holes on the bottom plate, the ventilation vertical slots of the placement slots, and the ventilation oblique slots on the inner side of the bottom plate cooperate with each other to form a full-range air circulation channel, which can effectively reduce the accumulation of sweat at the contact point between the patient's limbs and the orthosis, and reduce the risk of skin infection. In addition, the setting of multiple fixing straps not only strengthens the fixation, but also reserves space for air circulation, further improving the comfort of patients for long-term wearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 It is a schematic diagram of the overall structure of the connecting plate and the adjustment mechanism of the present invention;

[0020] Figure 3 1 is a front view structural diagram of a cross section of a connecting plate of the present invention;

[0021] Figure 4 is a schematic side view of the cross section of the connecting plate of the present invention;

[0022] Figure 5 It is a schematic diagram of the overall structure of the winding rod of the present invention;

[0023] Figure 6 This invention Figure 3 Schematic diagram of the enlarged structure at A in the middle;

[0024] Figure 7 This invention Figure 4 Schematic diagram of the enlarged structure at point B in the middle.

[0025] In the figure: 1. fixed plate; 2. placement groove; 3. bottom plate; 4. placement plate; 5. connecting plate; 6. winding groove; 7. winding rod; 8. fixing belt 1; 9. adjustment mechanism; 10. movable groove; 11. sliding plate 1; 12. plug-in rod 1; 13. spring 1; 14. plug-in rod 2; 15. plug interface; 16. connecting hole; 17. air inlet; 18. fixing belt 2; 19. ventilation vertical groove; 20. ventilation inclined groove; 21. limiting groove; 22. slider; 23. sliding cavity; 24. sliding plate 2; 25. spring 2; 26. U-shaped limiting slide rod; 27. limiting circular hole; 28. anti-slip groove; 901. rotating disk; 902. rotating rod; 903. worm; 904. worm wheel. DETAILED DESCRIPTION

[0026] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Example

[0028] like Figure 1-Figure 5 As shown, an orthopedic reduction and fixation orthosis is provided, comprising a fixing plate 1, a placement groove 2 being provided on the front surface of the fixing plate 1, a bottom plate 3 being provided on the lower surface of the fixing plate 1, a placement plate 4 being fixedly connected to the inner side wall of the bottom plate 3; a connecting plate 5 being fixedly connected to the right side of the fixing plate 1, a winding groove 6 being provided on the front surface of the connecting plate 5, a winding rod 7 being provided inside the winding groove 6, a plurality of fixing belts 8 being fixedly connected to the outer side wall of the winding rod 7, the plurality of fixing belts 8 being fixedly connected to the left side of the front surface of the fixing plate 1 on one side away from the winding rod 7; an adjusting mechanism 9 being provided on the upper surface of the connecting plate 5;

[0029] When it is necessary to wear the orthopedic reduction and fixation orthosis, the patient's limb is first placed on the placement groove 2 of the fixation plate 1 and the placement plate 4 on the inner side of the bottom plate 3, and then the adjustment mechanism 9 is operated, which will drive the winding rod 7 in the winding groove 6 to rotate. During the rotation of the winding rod 7, multiple fixing belts 8 can be wound up at the same time, so that the fixing belt 8 can be quickly tightened and fit the patient's limb to achieve fixation, and complete quick wearing. The adjustment mechanism 9 can be used to simultaneously wind up multiple fixing belts 8, without the need to tighten multiple straps in sequence, which can significantly shorten the wearing time. In emergency treatment, the injured limb can be quickly fixed, reducing the risk of secondary injury. It is easier for patients or caregivers to operate, reducing the difficulty of self-care and the burden of care. At the same time, the synchronous winding of multiple fixing belts 8 can ensure uniform force, improve fixation stability, and also reduce the time for medical staff to provide guidance and assistance, thereby improving medical efficiency.

[0030] like Figure 1 、 Figure 2 、 Figure 4 、 Figure 6 and Figure 7As shown, a movable groove 10 is provided on the front surface of the connecting plate 5 and below the winding groove 6. A sliding plate 11 is slidably connected to the interior of the movable groove 10. The upper surface of the sliding plate 11 is rotatably connected to a plug rod 12 via a rotating shaft. The lower surface of the sliding plate 11 and the inner lower surface of the movable groove 10 are fixedly connected to a plurality of springs 13. The inner upper surface of the winding groove 6 is rotatably connected to a plug rod 2 14 via a rotating shaft. Plug interfaces 15 are provided on the upper and lower surfaces of the winding rod 7. The opposite ends of the plug rod 12 and the plug rod 2 14 respectively extend to the interiors of the two plug interfaces 15.

[0031] The movable slot 10 has a limit slot 21 formed on the left and right sides thereof. The left and right sides of the sliding plate 11 are fixedly connected with sliders 22. The opposite sides of the two sliders 22 are respectively slidably connected to the inside of the two limit slots 21.

[0032] Initially, the winding rod 7 is outside the winding slot 6. At this time, multiple fixing belts 8 are in a loose and expanded state, which will not form an obstacle to the patient's limbs being placed in the placement slot 2. The patient can easily and smoothly place the limbs in the placement slot 2 and the placement plate 4. When the patient's limbs are placed in place, the sliding plate 11 is pressed downward, and the sliding plate 11 slides downward in the movable slot 10. The left and right sliders 22 slide synchronously in the limit slots 21 to ensure that the sliding plate 11 moves smoothly. At the same time, the spring 13 is compressed to make the connecting rod 12 descend with the sliding plate 11. At this time, the plug-in interface 15 under the winding rod 7 is aligned with the plug-in rod 12 and inserted. Then, the pressure on the sliding plate 11 is released, and the spring 13 rebounds to push the sliding plate 11 upward, driving the plug-in rod 12 to rise and tightly fit into the plug-in interface 15 under the winding rod 7. Then adjust the winding rod 7 The angle of the reel 11 is adjusted so that the plug-in interface 15 at the top is aligned with and inserted into the plug-in rod 2 14, completing the quick fixation of the reeling rod 7 in the reeling slot 6. In the initial state, the reeling rod 7 is not in the reeling slot 6, effectively avoiding the obstruction of the fixing belt 8 to the patient's wearing, greatly reducing the difficulty of putting the limb in. The plug-in fixation method of pressing the sliding plate 11 and adjusting the angle of the reeling rod 7 is simple and intuitive to operate, and the reeling rod 7 can be quickly installed in place without complicated steps, laying a convenient foundation for the subsequent control of the reeling rod 7 to rewind the fixing belt 8 through the adjustment mechanism 9. At the same time, the cooperation of the slider 22 and the limit groove 21 ensures the stability of the sliding plate 11 when sliding, and the rebound effect of the spring 13 can ensure the tightness of the connection between the plug-in rod 12 and the plug-in interface 15, thereby improving the reliability of the reeling rod 7 after fixation and further optimizing the wearing experience of the orthosis.

[0033] like Figure 1 As shown, the upper surface of the placement plate 4 is provided with a plurality of through-type communication holes 16, the inner left side and the inner right side of the bottom plate 3 are both provided with a plurality of through-type air inlet holes 17, and the upper surface of the bottom plate 3 is provided with a plurality of fixing belts 18;

[0034] A through-type ventilation vertical slot 19 is provided on the inner rear surface of the placement slot 2, and a ventilation inclined slot 20 is provided on the left and right sides of the inner side wall of the bottom plate 3 and above the placement plate 4;

[0035] When the patient wears the orthosis, the outside air can enter the bottom plate 3 through the multiple air inlet holes 17 below the bottom plate 3, and the air flows upward through the multiple through-type connecting holes 16 on the upper surface of the placement plate 4, directly acting on the part where the patient's limbs are in contact with the placement plate 4, and the ventilation vertical grooves 19 can promote the circulation of air in the placement grooves 2, so that the air on the back side of the limbs can circulate, and the various ventilation structures cooperate with each other to form a full-range air circulation path, and the gap reserved by the fixing belt 2 18 when fixing the limbs further enhances the fluidity of the air, thereby effectively reducing the stuffiness of the contact part between the patient's limbs and the orthosis, reducing the risk of skin itching, redness and swelling and even infection caused by sweat accumulation due to long-term wearing, improving the patient's wearing comfort, and keeping the limb skin dry, which is beneficial for the patient to maintain good treatment compliance during rehabilitation and promote smooth bone healing.

[0036] like Figure 1 、 Figure 2 、 Figure 3 and Figure 7 As shown, the adjustment mechanism 9 includes a rotating disk 901, a rotating rod 902 is fixedly connected to the center of the lower surface of the rotating disk 901, the bottom end of the rotating rod 902 extends into the interior of the winding groove 6 and is fixedly connected to a worm 903, and the outer wall of the winding rod 7 is fixedly connected to a worm wheel 904, and the outer wall of the worm wheel 904 is meshed with the outer wall of the worm wheel 903;

[0037] When it is necessary to control the winding rod 7 to rotate through the adjustment mechanism 9 to tighten the fixing belt 8, the operator only needs to rotate the rotating disk 901, and the rotating disk 901 will drive the rotating rod 902 fixedly connected to the center of its lower surface to rotate synchronously. The bottom end of the rotating rod 902 extends into the inside of the winding groove 6 and is fixedly connected to the worm 903. Therefore, when the rotating rod 902 rotates, it drives the worm 903 to rotate together, and the outer wall of the winding rod 7 is fixedly connected to the worm gear 904, and the worm gear 904 is meshed with the outer wall of the worm 903. The rotation of the worm gear 903 drives the worm gear 904 to rotate, and then drives the winding rod 7 to rotate in the winding groove 6 to achieve the winding operation of the fixing belt 8. When it is necessary to stop winding or adjust the tightness of the fixing belt 8, just stop rotating the rotating disk 901. Because the worm gear 904 and the worm gear The rod 903 is self-locking. In the absence of external force driving the worm 903 to rotate, the worm wheel 904 cannot drive the worm 903 to rotate in the opposite direction, thereby effectively preventing the winding rod 7 from rotating due to factors such as the return force of the fixing belt 8 during the winding process, ensuring that the fixing belt 8 is always in a stable tightening state, so that the tightening adjustment of multiple fixing belts 8 can be completed by manual operation by only one person without the need for complex tools, and the meshing transmission of the worm wheel 904 and the worm 903 can achieve precise speed control, which is convenient for the operator to fine-tune the tightness of the fixing belt 8 according to the actual situation of the patient's limbs, thereby improving the comfort and stability of the fixation. At the same time, the anti-rotation effect brought by the self-locking property avoids the problem of loosening of the fixing belt 8 due to accidental rotation of the winding rod 7, thereby affecting the fixation effect, and further ensures the fixation reliability of the orthosis.

[0038] like Figure 7 As shown, a sliding cavity 23 is integrally formed inside the connecting plate 5 and above the winding groove 6. A sliding plate 24 is slidably connected to the interior of the sliding cavity 23. Two springs 25 are fixedly connected to the lower surface of the sliding plate 24 and the lower surface of the interior of the sliding cavity 23. A U-shaped limiting slide 26 is rotatably connected to the upper surface of the sliding plate 24. A plurality of limiting circular holes 27 are opened on the upper surface of the rotating disk 901. The U-shaped limiting slide 26 extends from one end of the sliding plate 24 away from the second sliding plate to the interior of the front limiting circular hole 27.

[0039] When the tightness of the plurality of fixing belts 8 is adjusted, the U-shaped limiting slide bar 26 extends away from one end of the sliding plate 24 to the inside of the front limiting circular hole 27 corresponding to the upper surface of the rotating disk 901, thereby further locking the rotating disk 901 to prevent it from accidentally rotating in a non-operating state. When it is necessary to rotate the rotating disk 901 again to adjust the tightness of the plurality of fixing belts 8, the U-shaped limiting slide bar 26 is pulled upward, and the U-shaped limiting slide bar 26 will drive the sliding plate 24 to slide upward in the sliding cavity 23 and stretch the spring 25, so that the end of the U-shaped limiting slide bar 26 disengages from the limiting circular hole 27, thereby canceling the limit on the rotating disk 901, and the rotating disk 901 can be rotated freely at this time. 01 to adjust the tightness, the U-shaped limit slide 26 and the limit circular hole 27 can be used to cooperate with each other to provide a double locking effect after the tightness of the fixing belt 8 is adjusted. Combined with the self-locking properties of the worm gear 904 and the worm 903, the reliability of the locking of the rotating disk 901 is further improved, and the situation that the rotating disk 901 accidentally rotates due to external forces such as vibration and collision, which causes the tightness of the fixing belt 8 to change is effectively avoided, thereby ensuring the stability of the fixing effect. At the same time, when adjustment is needed, the U-shaped limit slide 26 only needs to be pulled up to cancel the limit. The operation is simple and quick, and no additional tools are required. It not only meets the stability of the locking, but also takes into account the flexibility of adjustment, thereby greatly improving the convenience and safety of use.

[0040] like Figure 3 and Figure 7 As shown, the outer side wall of the rotating disc 901 is integrally formed with an anti-slip groove 28;

[0041] When the operator rotates the rotating disk 901 to adjust the tightness of the fixing belt 8, the anti-slip groove 28 can effectively increase the friction between the hand and the outer wall of the rotating disk 901. Even if the operator's hands are sweaty or water-stained or wearing gloves, the anti-slip groove 28 can fit the hand to avoid slipping, allowing the operator to hold the rotating disk 901 more firmly, thereby accurately controlling the rotation force and angle, ensuring that the tightness adjustment of the fixing belt 8 is more accurate and smooth. At the same time, the design of the anti-slip groove 28 is ergonomic, which can improve the comfort of the hand when holding the rotating disk 901, reduce hand fatigue caused by long-term operation, make the entire adjustment process more labor-saving and convenient, and further optimize the operating experience of the orthosis.

[0042] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An orthopedic reduction and fixation orthosis, comprising a fixing plate (1), characterized in that: The front surface of the fixing plate (1) is provided with a placement groove (2), the lower surface of the fixing plate (1) is provided with a bottom plate (3), and the inner side wall of the bottom plate (3) is fixedly connected with a placement plate (4); The right side of the fixed plate (1) is fixedly connected to a connecting plate (5), a front surface of the connecting plate (5) is provided with a winding groove (6), an interior of the winding groove (6) is provided with a winding rod (7), an outer side wall of the winding rod (7) is fixedly connected to a plurality of fixing belts (8), and the side of the plurality of fixing belts (8) away from the winding rod (7) is fixedly connected to the left side of the front surface of the fixed plate (1); An adjustment mechanism (9) is provided on the upper surface of the connecting plate (5).

2. The orthopedic reduction and fixation orthosis according to claim 1, characterized in that: A movable groove (10) is provided on the front surface of the connecting plate (5) and below the winding groove (6); a sliding plate (11) is slidably connected to the interior of the movable groove (10); the upper surface of the sliding plate (11) is rotatably connected to a plug-in rod (12) via a rotating shaft; the lower surface of the sliding plate (11) and the inner lower surface of the movable groove (10) are fixedly connected to a plurality of springs (13); the inner upper surface of the winding groove (6) is rotatably connected to a plug-in rod (14) via a rotating shaft; an insertion interface (15) is provided on the upper and lower surfaces of the winding rod (7); the opposite ends of the plug-in rod (12) and the plug-in rod (14) respectively extend to the interior of the two insertion interfaces (15).

3. The orthopedic reduction and fixation orthosis according to claim 1, characterized in that: The upper surface of the placement plate (4) is provided with a plurality of through-type communicating holes (16), the inner left side and the inner right side of the bottom plate (3) are both provided with a plurality of through-type air inlet holes (17), and the upper surface of the bottom plate (3) is provided with a plurality of fixing belts (18).

4. The orthopedic reduction and fixation orthosis according to claim 1, characterized in that: The adjusting mechanism (9) comprises a rotating disc (901), a rotating rod (902) fixedly connected to the center of the lower surface of the rotating disc (901), a bottom end of the rotating rod (902) extending to the interior of the winding groove (6) and fixedly connected to a worm (903), an outer side wall of the winding rod (7) fixedly connected to a worm wheel (904), and an outer side wall of the worm wheel (904) meshingly connected to the outer side wall of the worm wheel (903).

5. The orthopedic reduction and fixation orthosis according to claim 1, characterized in that: A through-type ventilation vertical groove (19) is provided on the inner rear surface of the placement groove (2), and a ventilation inclined groove (20) is provided on the left and right sides of the inner side wall of the bottom plate (3) and located above the placement plate (4).

6. The orthopedic reduction and fixation orthosis according to claim 2, characterized in that: The movable groove (10) is provided with a limiting groove (21) on the left and right sides thereof, and the left and right sides of the sliding plate (11) are fixedly connected with sliders (22), and the opposite sides of the two sliders (22) are respectively slidably connected to the inside of the two limiting grooves (21).

7. The orthopedic reduction and fixation orthosis according to claim 4, characterized in that: A sliding cavity (23) is integrally formed inside the connecting plate (5) and above the winding groove (6), and a sliding plate 2 (24) is slidably connected inside the sliding cavity (23), and two springs 2 (25) are fixedly connected to the lower surface of the sliding plate 2 (24) and the lower surface of the interior of the sliding cavity (23), and a U-shaped limiting slide rod (26) is rotatably connected to the upper surface of the sliding plate 2 (24), and a plurality of limiting circular holes (27) are opened on the upper surface of the rotating disc (901), and the U-shaped limiting slide rod (26) extends from one end of the sliding plate 2 (24) to the inside of the limiting circular hole (27) in front.

8. The orthopedic reduction and fixation orthosis according to claim 4, characterized in that: The outer side wall of the rotating disc (901) is integrally formed with an anti-slip groove (28).

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