Medical bidirectional fixed torque screwdriver
By designing a medical bidirectional constant torque screwdriver, which adopts a housing, cutting head and ratchet structure, bidirectional torque control is achieved, solving the problem of equipment damage caused by unidirectional torque in the existing technology, and meeting the precision assembly and extreme working conditions requirements of medical scenarios.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU CED MEDTECH CO LTD
- Filing Date
- 2025-04-28
- Publication Date
- 2026-07-21
Smart Images
Figure CN224523227U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of medical screwdriver technology, and in particular to a medical bidirectional constant torque screwdriver. Background Technology
[0002] Torque screwdrivers play a crucial role in the assembly of medical devices, such as orthopedic implant fixation, minimally invasive surgical instrument assembly, and wearable medical device maintenance. Medical applications place specific demands on torque control: on the one hand, they must meet the stringent assembly accuracy standards of the ISO 13485 medical device quality management system (e.g., spinal screw implantation torque error ≤ ±3%); on the other hand, they must withstand extreme conditions such as high-frequency, high-temperature, and high-pressure sterilization (121℃ steam sterilization, ≥5 times per week) and corrosive media (sodium hypochlorite disinfectant). However, existing medical torque screwdrivers mostly utilize unidirectional constant torque technology from the industrial field, exhibiting significant shortcomings in disassembly, rework, and reassembly processes.
[0003] Currently, mainstream products in the medical field still rely on unidirectional torque screwdrivers. When performing operations such as reverse disassembly of orthopedic locking screws or adjustment of pacemaker fixing bolts, operators are forced to switch to torque-free control mode. Clinical studies have shown that such operations result in thread stripping in 28% of repair cases (data source: *Journal of Medical Device*, 2022), especially in titanium alloy implanted screws in osteoporosis patients, where excessive reverse torque may cause microcracks at the bone interface. Meanwhile, traditional solutions are insufficient to meet the demands of emerging medical technologies: for example, surgical robot end effectors require lightweight tools with a diameter ≤15mm, independently adjustable forward and reverse torque (0.3-5 N·m forward, 0.1-3 N·m reverse), and must be resistant to gamma-ray sterilization.
[0004] Therefore, it is necessary to develop a bidirectional constant torque screwdriver that is adaptable to medical scenarios, so as to meet the upgrade requirements of medical precision assembly from "one-way controllability" to "two-way traceability". Utility Model Content
[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a medical bidirectional constant torque screwdriver to solve the problem that the torque screwdrivers in the prior art can only provide a constant torque in one direction.
[0006] To achieve the above and other related objectives, this utility model provides a medical bidirectional torque screwdriver, comprising a housing and a cutting head. The housing includes a cavity, and the cutting head includes a connecting body and a first connecting portion. The first connecting portion is located at the bottom of the cavity, and the cutting head body is located outside the housing. A cutting head ratchet is fitted on the first connecting portion. A double-sided ratchet and a torque ratchet are sequentially provided on the cutting head ratchet. A guide rail is provided on the side wall of the cavity, and a slider that can slide relative to the guide rail is provided on the torque ratchet. A rear cover is provided on the top of the housing, and a gasket is provided below the rear cover. A screw is provided between the gasket and the first connecting portion. An elastic element is fitted on the screw. One end of the elastic element is connected to the torque ratchet, and the other end of the elastic element abuts against the gasket.
[0007] In some embodiments of this utility model, the outer diameter of the first connecting part is larger than the outer diameter of the cutter head body.
[0008] In some embodiments of this utility model, the cutter ratchet includes a connected cutter ratchet body and a second connecting part, wherein the cutter ratchet body is located at the bottom of the cavity, and the double-sided ratchet and the torque ratchet are sequentially sleeved on the second connecting part.
[0009] In some embodiments of this utility model, the bottom of the first connecting part is provided with a first protrusion, and the bottom of the cutter ratchet is provided with a groove that cooperates with the first protrusion.
[0010] In some embodiments of this utility model, the inner diameter of the second connecting part is equal to the inner diameter of the cutter ratchet body; the outer diameter of the second connecting part is equal to the inner diameter of the double-sided ratchet; and the outer diameter of the double-sided ratchet is equal to the outer diameter of the cutter ratchet body.
[0011] The outer diameter of the torque ratchet is equal to the outer diameter of the cutter ratchet body; at least a portion of the inner diameter of the torque ratchet is equal to the outer diameter of the second connecting portion;
[0012] The outer diameter of the ratchet body is smaller than the diameter of the cavity.
[0013] In some embodiments of this utility model, the cutter ratchet body includes a first ratchet tooth, the double-sided ratchet includes a second ratchet tooth and a third ratchet tooth, the first ratchet tooth and the second ratchet tooth cooperate with each other, and the torque ratchet includes a fourth ratchet tooth, the fourth ratchet tooth cooperates with the third ratchet tooth.
[0014] In some embodiments of this utility model, the number of guide rails is 3 to 6, and the number of sliders corresponds one-to-one with the number of guide rails.
[0015] In some embodiments of this utility model, a second protrusion is provided on the top of the torque ratchet, one end of the elastic member is sleeved on the second protrusion, and the other end of the elastic member abuts against the gasket.
[0016] In some embodiments of this utility model, the first connecting part is provided with a screw receiving cavity, a portion of the screw is disposed in the screw receiving cavity, one end of the screw is threadedly connected to the screw receiving cavity, and there is a nut receiving cavity between the rear cover and the gasket, with the nut end of the screw disposed in the nut receiving cavity.
[0017] In some embodiments of this utility model, the elastic element is a spring.
[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0019] This invention provides a constant torque in both directions, preventing damage to the equipment when using it under conditions where screws need to be tightened and torque needs to be limited.
[0020] This utility model provides two types of screwdrivers with different top torque values, where the torque for loosening the screw (the set loosening torque value) is greater than the torque for tightening the screw (the set tightening torque value), thereby achieving:
[0021] 1. Screws tightened with this screwdriver can be unscrewed normally with this screwdriver;
[0022] 2. This screwdriver can unscrew screws with a torque less than the screw-out torque of this screwdriver (set loosening torque value);
[0023] 3. This screwdriver cannot unscrew screws that require a torque greater than the screw-out torque of this screwdriver (the set loosening torque value). Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the structure of the medical bidirectional constant torque screwdriver of this utility model.
[0025] Figure 2 for Figure 1 A schematic diagram of the AA-direction cross-section structure.
[0026] Figure 3 This is a structural schematic diagram of the medical bidirectional constant torque screwdriver (excluding the housing and back cover) of this utility model.
[0027] Figure 4 for Figure 3 A schematic diagram of the AA-direction cross-section structure.
[0028] Figure 5 This is a three-dimensional structural diagram of the medical bidirectional constant torque screwdriver (excluding the housing and back cover) of this utility model.
[0029] Figure 6 This is a three-dimensional structural diagram of the blade of this utility model.
[0030] Figure 7 This is a top view of the medical casing of this utility model.
[0031] Figure 8 This is a three-dimensional structural diagram of the medical shell of this utility model.
[0032] Figure 9 This is a schematic diagram of the main structure of the double-sided ratchet of this utility model.
[0033] Figure 10 This is a three-dimensional structural diagram of the double-sided ratchet of this utility model.
[0034] Component designation explanation:
[0035] 1. Shell
[0036] 11. Cavity
[0037] 111 guide rail
[0038] 2. Blade head
[0039] 21. Blade Body
[0040] 211 First protrusion
[0041] 22 First connecting part
[0042] 221 Screw receiving cavity
[0043] 3. Ratchet with blade tip
[0044] 31. Ratchet body of the cutter head
[0045] 311 First ratchet
[0046] 32 Second connecting part
[0047] 4 Double-sided ratchet
[0048] 41 Second ratchet
[0049] 42 Third ratchet
[0050] 5 Torque Ratchet
[0051] 51 Fourth ratchet
[0052] 52 sliders
[0053] 53 Second protrusion
[0054] 6. Back cover
[0055] 7 gaskets
[0056] 71 Nut Receiving Cavity
[0057] 8 screws
[0058] 9. Elastic components Detailed Implementation
[0059] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. These embodiments are only used to illustrate this utility model and are not intended to limit it.
[0060] The terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0061] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0062] Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0063] like Figures 1-10 As shown, this utility model embodiment provides a medical bidirectional constant torque screwdriver. Specifically, as... Figure 2The screwdriver includes a housing 1 and a cutting head 2. The housing 1 includes a cavity 11. The cutting head 2 includes a connecting body 21 and a first connecting part 22. The first connecting part 22 is located at the bottom of the cavity 11. The cutting head body 21 is located outside the housing 1. A cutting head ratchet 3 is fitted on the first connecting part 22. A double-sided ratchet 4 and a torque ratchet 5 are sequentially provided on the cutting head ratchet 3. A guide rail 111 is provided on the side wall of the cavity 11. A slider 52 that can slide relative to the guide rail 111 is provided on the torque ratchet 5. A rear cover 6 is provided on the top of the housing 1. A gasket 7 is provided below the rear cover 6. A screw 8 is provided between the gasket 7 and the first connecting part 22. An elastic element 9 is fitted on the screw 8. One end of the elastic element 9 is connected to the torque ratchet 5, and the other end of the elastic element 9 abuts against the gasket 7.
[0064] In the medical bidirectional constant torque screwdriver provided in this embodiment of the utility model, in order to prevent the first connecting part 22 located at the bottom of the cavity 11 from sliding out of the cavity 11, the outer diameter of the first connecting part 22 is larger than the outer diameter of the screwdriver body 21.
[0065] In the medical bidirectional constant torque screwdriver provided in this embodiment of the utility model, such as Figure 2 The cutter ratchet 3 includes a cutter ratchet body 31 and a second connecting part 32 connected together. The cutter ratchet body 31 is located at the bottom of the cavity 11, and the double-sided ratchet 4 and the torque ratchet 5 are sequentially sleeved on the second connecting part 32.
[0066] In the medical bidirectional constant torque screwdriver provided in this embodiment of the utility model, the ratchet 3 and the cutter head 2 are injection molded together. For example... Figure 6 The bottom of the first connecting part 22 is provided with a first protrusion 211, and the bottom of the cutter ratchet 3 is provided with a groove that cooperates with the first protrusion 211. Through the cooperation of the first protrusion 211 and the groove, the relative sliding between the cutter head 2 and the cutter ratchet 3 can be prevented.
[0067] In the medical bidirectional constant torque screwdriver provided in this embodiment of the utility model, such as Figure 2 The outer diameter of the ratchet body 31 is smaller than the diameter of the cavity 11. The inner diameter of the second connecting portion 32 is equal to the inner diameter of the ratchet body 31; the outer diameter of the second connecting portion 32 is equal to the inner diameter of the double-sided ratchet 4; the outer diameter of the double-sided ratchet 4 is equal to the outer diameter of the ratchet body 31; the outer diameter of the torque ratchet 5 is equal to the outer diameter of the ratchet body 31; at least a portion of the inner diameter of the torque ratchet 5 is equal to the outer diameter of the second connecting portion 32.
[0068] In the medical bidirectional constant torque screwdriver provided in this embodiment of the utility model, such as Figure 3The cutter ratchet body 31 includes a first ratchet 311, which is located between the cutter ratchet body 31 and the double-sided ratchet 4. The double-sided ratchet 4 includes a second ratchet 41 and a third ratchet 42. The second ratchet 41 is located between the double-sided ratchet 4 and the cutter ratchet body 31, and the third ratchet 42 is located between the double-sided ratchet 4 and the torque ratchet 5. The first ratchet 311 and the second ratchet 41 cooperate with each other. The torque ratchet 5 includes a fourth ratchet 51, which is located between the torque ratchet 5 and the double-sided ratchet 4. The fourth ratchet 51 cooperates with the third ratchet 42.
[0069] In the design, when the elastic force of the elastic element 9 remains constant, the tightening torque can be achieved by simultaneously changing the angle of the first ratchet 311 on the ratchet body 31 and the second ratchet 41 on the mating double-sided ratchet 4; the loosening torque can be achieved by simultaneously changing the angle of the fourth ratchet 51 on the torque ratchet 5 and the third ratchet 42 on the mating double-sided ratchet 4. Alternatively, the tightening and loosening torques can be increased simultaneously by adjusting the spring force.
[0070] In the medical bidirectional constant torque screwdriver provided in this embodiment of the utility model, the number of guide rails 111 is 3 to 6, and the number of sliders 52 corresponds one-to-one with the number of guide rails 111. In a specific embodiment, as shown... Figure 8 The number of guide rails 111 and the second protrusion can be, for example, four. The slider 52 can slide relative to the guide rails 111, thereby driving the torque ratchet 5 to move up and down.
[0071] In the medical bidirectional constant torque screwdriver provided in this embodiment of the utility model, such as Figure 2 The torque ratchet 5 has a second protrusion 53 on its top, one end of the elastic member 9 is sleeved on the second protrusion 53, and the other end of the elastic member 9 abuts against the gasket 7.
[0072] In the medical bidirectional constant torque screwdriver provided in this embodiment of the utility model, the first connecting part 22 is provided with a screw receiving cavity 221. One end of the screw 8 is threadedly connected to the screw receiving cavity 221 and fixed in the screw receiving cavity 221 of the first connecting part of the screw head. There is a nut receiving cavity 71 between the rear cover 6 and the washer 7. The screw 8 includes a screw body and a nut. The nut end of the screw 8 is located in the nut receiving cavity 71. For example, the washer 7 is provided with a through hole, the diameter of which is smaller than that of the nut. In this way, the nut is located in the nut receiving cavity, and the screw body passes through the through hole and is connected to the screw receiving cavity 221.
[0073] In the medical bidirectional constant torque screwdriver provided in this embodiment of the utility model, the elastic element 9 can be, for example, a spring.
[0074] In the medical bidirectional constant torque screwdriver provided in this embodiment of the utility model, the rear cover 6 and the housing 1 are bonded together with adhesive.
[0075] The working process of this utility model:
[0076] 1. Turn clockwise (tighten the screw)
[0077] Initial state: When the screwdriver rotates clockwise, the housing 1 drives the torque ratchet 5 to rotate via the guide rail 111.
[0078] Locking stage: Torque ratchet 5 and double-sided ratchet 4 are locked, and at this time they rotate as a whole. Cutter head ratchet 3 and double-sided ratchet 4 are also locked, and torque is transmitted to the screw through the cutter head 2.
[0079] Torque limiting: When the torque applied to the screwdriver head reaches the set tightening torque value, the friction between the double-sided ratchet 4 and the screwdriver head ratchet 3 is insufficient to continue transmitting torque, and the double-sided ratchet 4 and the screwdriver head ratchet 3 begin to slide relative to each other. At this time, the spring is compressed, which acts as a buffer to prevent further torque transmission, thereby protecting the screw and screwdriver.
[0080] Notification function: When the double-sided ratchet 4 and the cutter head ratchet 3 begin to slide, a "clicking" sound is usually emitted to remind the operator that the torque has reached the set value.
[0081] 2. Turn counterclockwise (to loosen the screw)
[0082] Initial state: When the screwdriver is turned counterclockwise, the screwdriver head ratchet 3 and the double-sided ratchet 4 are locked, and the torque ratchet 5 and the double-sided ratchet 4 are separated.
[0083] Locking phase: Torque is transmitted to the screw through the cutter head ratchet 3 and the double-sided ratchet 4 to loosen the screw.
[0084] Torque limiting: When the torque applied to the cutter head 2 reaches the set loosening torque value, the friction between the double-sided ratchet 4 and the torque ratchet 5 is insufficient to continue transmitting torque, and the double-sided ratchet 4 and the torque ratchet 5 begin to slide relative to each other. At this time, the spring is compressed, which acts as a buffer to prevent further torque transmission.
[0085] Notification function: Similarly, when the ratchet starts to slide, it will make a "clicking" sound to remind the operator that the torque has reached the set value.
[0086] In this invention, the tightening torque of the screwdriver is set to be less than the loosening torque. This invention provides two types of screwdrivers with different top torques, where the torque for loosening the screw (set loosening torque) is greater than the torque for tightening the screw (set tightening torque), thereby achieving:
[0087] 1. Screws tightened with this screwdriver can be unscrewed normally with this screwdriver;
[0088] 2. For screws where the torque required to unscrew the screw is less than the screw-out torque of this screwdriver (the set loosening torque value), this screwdriver can still unscrew the screw normally;
[0089] 3. This screwdriver cannot unscrew screws that require a torque greater than the screw-out torque of this screwdriver (the set loosening torque value).
[0090] In summary, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value.
[0091] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.
Claims
1. A medical bidirectional constant torque screwdriver, characterized in that, The device includes a housing (1) and a cutting head (2). The housing (1) includes a cavity (11). The cutting head (2) includes a connecting body (21) and a first connecting part (22). The first connecting part (22) is located at the bottom of the cavity (11). The cutting head body (21) is located outside the housing (1). A cutting head ratchet (3) is sleeved on the first connecting part (22). A double-sided ratchet (4) and a torque ratchet (5) are sequentially provided on the cutting head ratchet (3). The side wall of the cavity (11) is... A guide rail (111) is provided, and a slider (52) that can slide relative to the guide rail (111) is provided on the torque ratchet (5); a rear cover (6) is provided on the top of the housing (1), and a gasket (7) is provided below the rear cover (6). A screw (8) is provided between the gasket (7) and the first connecting part (22). An elastic element (9) is sleeved on the screw (8). One end of the elastic element (9) is connected to the torque ratchet (5), and the other end of the elastic element (9) abuts against the gasket (7).
2. The medical bidirectional constant torque screwdriver according to claim 1, characterized in that, The outer diameter of the first connecting part (22) is larger than the outer diameter of the cutter body (21).
3. The medical bidirectional constant torque screwdriver according to claim 1, characterized in that, The cutter ratchet (3) includes a connected cutter ratchet body (31) and a second connecting part (32), wherein the cutter ratchet body (31) is located at the bottom of the cavity (11), and the double-sided ratchet (4) and the torque ratchet (5) are sequentially sleeved on the second connecting part (32).
4. The medical bidirectional constant torque screwdriver according to claim 1, characterized in that, The bottom of the first connecting part (22) is provided with a first protrusion (211), and the bottom of the cutter ratchet (3) is provided with a groove that matches the first protrusion (211).
5. The medical bidirectional constant torque screwdriver according to claim 3, characterized in that, The inner diameter of the second connecting part (32) is equal to the inner diameter of the cutter ratchet body (31); the outer diameter of the second connecting part (32) is equal to the inner diameter of the double-sided ratchet (4); the outer diameter of the double-sided ratchet (4) is equal to the outer diameter of the cutter ratchet body (31); The outer diameter of the torque ratchet (5) is equal to the outer diameter of the cutter ratchet body (31); at least a portion of the inner diameter of the torque ratchet (5) is equal to the outer diameter of the second connecting part (32); the outer diameter of the cutter ratchet body (31) is smaller than the diameter of the cavity (11).
6. The medical bidirectional constant torque screwdriver according to claim 3, characterized in that, The cutter head ratchet body (31) includes a first ratchet tooth (311), the double-sided ratchet (4) includes a second ratchet tooth (41) and a third ratchet tooth (42), the first ratchet tooth (311) and the second ratchet tooth (41) cooperate with each other, and the torque ratchet (5) includes a fourth ratchet tooth (51), the fourth ratchet tooth (51) cooperates with the third ratchet tooth (42).
7. The medical bidirectional constant torque screwdriver according to claim 1, characterized in that, The number of guide rails (111) is 3 to 6, and the number of sliders (52) corresponds one-to-one with the number of guide rails (111).
8. The medical bidirectional constant torque screwdriver according to claim 1, characterized in that, The torque ratchet (5) has a second protrusion (53) on its top, and the elastic element (9) is sleeved on the second protrusion (53).
9. The medical bidirectional constant torque screwdriver according to claim 1, characterized in that, The first connecting part (22) is provided with a screw receiving cavity (221), one end of the screw (8) is threadedly connected to the screw receiving cavity (221), and there is a nut receiving cavity (71) between the rear cover (6) and the gasket (7), and the nut end of the screw (8) is located in the nut receiving cavity (71).
10. The medical bidirectional constant torque screwdriver according to claim 1, characterized in that, The elastic element (9) is a spring.