Extensible test mold

Abstract

The invention provides a test mold capable of being opened. The test mold comprises a handle, the near end of the transmission mechanism is connected with the handle; the distraction assembly is connected with the far end of the transmission mechanism, and the distraction assembly comprises a main body piece and a first distraction piece movably arranged on the main body piece; when the handle rotates, force acts on the first opening piece through the transmission mechanism, so that the first opening piece and the main body piece get close to each other or get away from each other. According to the test mold capable of being expanded, the length size of the expanding assembly can be adjusted by rotating the handle, so that a doctor can accurately simulate the condition of being implanted into an object only through one test mold in the operation process, other test molds do not need to be frequently inserted and taken out in the operation process, damage to surrounding tissue is avoided, and the operation efficiency is improved. The risk of operative complications is reduced, and the success rate of an operation is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a expandable trial mold. Background Art

[0002] Intervertebral fusion is a surgical procedure mainly used to treat lumbar diseases such as lumbar disc herniation, spinal stenosis, and spondylolisthesis. The process of intervertebral fusion surgery includes establishing a minimally invasive channel to enter the lesion area, or performing an open surgery to expose the diseased intervertebral disc and vertebral body, then cleaning the lesion area. Under the condition of minimizing damage to the surrounding tissues during the surgery, a fusion cage is implanted between adjacent vertebral segments through an auxiliary instrument tool, and it will fuse with the adjacent vertebral bodies to form a whole, stabilizing the spine.

[0003] In the trial mold used in the planning of intervertebral fusion surgery, the trial mold acts as a measuring instrument during the intervertebral fusion surgery, and is generally used to measure size data such as diameter and depth during orthopedic surgery. For traditional fixed-size intervertebral fusion cages, different specifications and sizes of trial molds need to be inserted, compared, and removed one by one from small to large before implantation until the correct size suitable for the patient is matched, and the whole process should be evaluated under fluoroscopic imaging to determine the appropriate length and position of the final implant. This greatly increases the surgical time, and during the surgery, frequent insertion and removal of different-sized trial molds to determine the size data of the implant will cause tissue damage and increase the surgical risk. Summary of the Invention

[0004] The purpose of the present invention is to provide an expandable trial mold, which can adjust the size of the trial mold, reducing the surgical time and surgical risk.

[0005] To achieve the above purpose, in a first aspect, the present invention provides an expandable trial mold including: A handle; A transmission mechanism, the proximal end of which is connected to the handle; An expansion assembly, connected to the distal end of the transmission mechanism, the expansion assembly including a main body member and a first expansion member movably arranged on the main body member; When the handle rotates, a force is applied to the first expansion member through the transmission mechanism, so that the first expansion member and the main body member approach or move away from each other. In some embodiments, the expansion assembly further includes a first connecting member located inside the first expansion member and fixedly connected to the first expansion member, and the first connecting member is in transmission connection with the transmission mechanism.

[0006] In some embodiments, the transmission mechanism includes a transmission shaft, a first support shaft, a first gear, a worm, and a first worm gear; The first support shaft is rotatably arranged inside the first expansion member; Both the first worm gear and the first gear are sleeved on the first support shaft and fixedly connected to the first support shaft. The worm is meshed with the first worm gear, and the proximal end of the worm is fixedly connected to the distal end of the transmission shaft. The proximal end of the transmission shaft is fixedly connected to the distal end of the handle. One side wall of the first connecting member is provided with a first rack structure, and the first rack structure is meshed with the first gear.

[0007] In some embodiments, the transmission mechanism further includes a first bearing sleeved on the end of the first support shaft, and the first bearing is fixedly connected to the main body member.

[0008] In some embodiments, the number of the first bearings, the first connecting members and the first gears are all two. The two first bearings are respectively sleeved on the two end parts of the first support shaft and are both fixedly connected to the main body member. The two first gears are sleeved on the first support shaft at intervals. The two first connecting members are arranged in the first expanding member at intervals and are respectively meshed with a corresponding one of the first gears.

[0009] In some embodiments, the transmission mechanism further includes at least one washer, and the washer is slidably sleeved on the end of the worm. When the worm rotates, the washer remains stationary.

[0010] In some embodiments, the lead angle of the worm is set to be less than its equivalent friction angle, and the transmission efficiency of the worm is less than 50%.

[0011] In some embodiments, the expanding assembly further includes a second expanding member and a second connecting member. The second expanding member is movably arranged on the main body member and is oppositely arranged with the first expanding member. The second connecting member is located in the second expanding member and is fixedly connected to the second expanding member, and the second connecting member is in transmission connection with the transmission mechanism. When the handle rotates, a force is applied to the first expanding member and the second expanding member through the transmission mechanism, so that the first expanding member and the second expanding member approach or move away from each other.

[0012] In some embodiments, the transmission mechanism further includes a second support shaft, a second gear and a second worm gear. The second support shaft is rotatably arranged in the second expanding member and is oppositely arranged with the first support shaft. The second worm gear and the second gear are both sleeved on the second support shaft and fixedly connected to the second support shaft; The distal end of the worm is meshed with the second worm gear, and the proximal end of the worm is fixedly connected to the distal end of the transmission shaft; One side wall of the second connecting member is provided with a second rack structure, and the second rack structure is meshed with the second gear.

[0013] In some embodiments, the transmission mechanism further includes a second bearing sleeved on the end of the second support shaft, and the second bearing is fixedly connected to the main body member.

[0014] In some embodiments, the number of the second bearings, the second connecting members and the second gears is two; The two second bearings are respectively sleeved on the two ends of the second support shaft and are both fixedly connected to the main body member; The two second gears are sleeved on the second support shaft at intervals; The two second connecting members are arranged in the second expanding member at intervals and are respectively meshed with a corresponding one of the second gears.

[0015] In some embodiments, a transmission channel is formed on the main body member; The transmission shaft is a double universal coupling, and the distal end of the transmission shaft is movably inserted into the transmission channel and fixedly connected to the proximal end of the worm.

[0016] In some embodiments, a first notch is formed on one side wall of the first expanding member close to the transmission channel, and a second notch is formed on one side wall of the second expanding member close to the transmission channel; When the first expanding member and the second expanding member approach each other, the diameter of the region formed by the cooperation of the first notch and the second notch is greater than the diameter of the transmission channel.

[0017] In some embodiments, distance marks are provided on partial side walls of the first connecting member and the second connecting member; Visual windows are formed on the first expanding member, the second expanding member and the main body member corresponding to the distance marks.

[0018] In some embodiments, the handle includes a holding portion, a connecting rod and a rotating portion; The holding portion has a hollow structure; The transmission shaft is movably inserted into the holding portion, and the proximal end of the transmission shaft is fixedly connected to the distal end of the connecting rod; The rotating portion is a ratchet handle, and the distal end of the ratchet handle is fixedly connected to the proximal end of the connecting rod.

[0019] The beneficial effects of the expandable test mold provided by the present invention are as follows: 1. The expansion component is connected to the handle through a transmission mechanism. By rotating the handle, the length dimension of the expansion component can be adjusted. Therefore, during the operation, only one such test mold is needed for the doctor to accurately simulate the situation inside the implanted object, and there is no need to frequently insert and remove other test molds during the operation, avoiding damage to the surrounding tissues, reducing the risk of surgical complications, and improving the success rate of the operation.

[0020] 2. The handle, the transmission mechanism and the expansion component are closely matched, and the handle has a self-locking function, enabling the expansion component to have a good expansion effect, improving the surgical efficiency, shortening the operation time, and reducing the pain and surgical risk of the patient.

[0021] 3. A visual window is provided on the expansion component, and the size of the expansion component after adjustment can be observed at any time during the operation, improving the accuracy during the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the expandable test mold according to the embodiment provided by the present invention; Figure 2 It is an exploded view of the expansion component and the transmission mechanism according to the embodiment provided by the present invention; Figure 3 It is a partial structural diagram of the transmission mechanism according to the embodiment provided by the present invention; Figure 4 It is a schematic structural diagram of the worm after installing a washer according to the embodiment provided by the present invention; Figure 5 It is a schematic structural diagram of the expandable test mold according to another embodiment provided by the present invention; Figure 6 It is a schematic structural diagram of the transmission mechanism connected to the first connecting member and the second connecting member according to the embodiment provided by the present invention; Figure 7 It is a schematic diagram of the first expansion member and the second expansion member arranged oppositely according to the embodiment provided by the present invention; Figure 8 It is a schematic structural diagram of the transmission mechanism connected to the first connecting member and the second connecting member according to another embodiment provided by the present invention; Figure 9 It is a schematic structural diagram of the main body member according to the embodiment provided by the present invention; Figure 10 It is a schematic structural diagram of the expandable test mold when the holding part completely accommodates the transmission shaft according to the embodiment provided by the present invention.

[0023] Reference numerals: Handle 1, gripping portion 11, connecting rod 12, rotating portion 13, transmission mechanism 2, transmission shaft 201, first support shaft 202, first gear 203, worm 204, first worm wheel 205, first bearing 206, washer 207, second support shaft 208, second gear 209, second worm wheel 210, second bearing 211, expansion assembly 3, main body 31, cylindrical structure 311, transmission channel 312, first expansion member 32, first notch 321, first connecting member 33, first rack structure 331, second expansion member 34, second notch 341, second connecting member 35, second rack structure 351, visible window 36. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the usual meanings understood by people with general skills in the field to which the present invention belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Unless otherwise specified, the "connection" described in this article can be a direct connection or an indirect connection, that is, connected through an intermediate.

[0025] In addition, it should be understood that the orientations or positional relationships indicated by "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. in this document are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. The "first" and "second" in this document are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0026] As used herein, the term "distal end" refers to the end that is away from the operator and closer to the patient; the term "proximal end" refers to the end that is closer to the operator and away from the patient.

[0027] In view of the problems existing in the prior art, an embodiment of the present invention provides a test mold that can be expanded. Figure 1and Figure 2 As shown, the expandable trial mold includes a handle 1, a transmission mechanism 2, and an expansion assembly 3. Among them, the proximal end of the transmission mechanism 2 is fixedly connected to the distal end of the handle 1, and the distal end of the transmission mechanism 2 is connected to the expansion assembly 3. The expansion assembly 3 includes a main body member 31 and a first expansion member 32 movably disposed on the main body member 31. Both the main body member 31 and the first expansion member 32 are sleeve-shaped structures. The first expansion member 32 is sleeved at one end of the main body member 31, and the end surface of the first expansion member 32 away from the main body member 31 is used to abut against the vertebral body surface. When the handle 1 rotates, a force is applied to the first expansion member 32 through the transmission mechanism 2, so that the first expansion member 32 and the main body member 31 approach or move away from each other.

[0028] In this embodiment, a convex sliding groove is provided on the outer side wall of the main body member 31 along its extending direction, and a concave sliding groove is provided on the inner side wall of the first expansion member 32 along its extending direction. The concave sliding groove is adapted to the convex sliding groove. Through the mutual cooperation of the concave sliding groove and the convex sliding groove, the stability of the first expansion member 32 during the sliding process is ensured.

[0029] In addition, it can be understood that for the expandable trial mold provided in this embodiment, since the length dimension of the expansion assembly 3 can be adjusted by rotating the handle 1, only one such trial mold is needed during the operation to enable the doctor to accurately simulate the situation inside the implanted object, and there is no need to frequently insert and remove other trial molds during the operation, avoiding damage to the surrounding tissues and reducing the risk of surgical complications, thereby improving the success rate of the operation.

[0030] Reference Figure 1 and Figure 2 As shown, in some embodiments, the expansion assembly 3 further includes a first connecting member 33 located inside the first expansion member 32 and fixedly connected to the first expansion member 32. The first connecting member 33 is in transmission connection with the transmission mechanism 2. When the handle 1 drives the transmission mechanism 2 to rotate, the transmission mechanism 2 can apply a rotational acting force on the first connecting member 33, and the first connecting member 33 can drive the first expansion member 32 to move along its extending direction after being stressed.

[0031] Specifically, in combination with Figure 3 , 4As shown in the figure, the transmission mechanism 2 includes a transmission shaft 201, a first support shaft 202, a first gear 203, a worm 204 and a first worm gear 205. The first support shaft 202 is rotatably arranged in the first expanding member 32. Both the first worm gear 205 and the first gear 203 are sleeved on the first support shaft 202 and fixedly connected to the first support shaft 202. Therefore, the first support shaft 202, the first worm gear 205 and the first gear 203 can rotate synchronously. The helical tooth structure near the distal end of the worm 204 meshes with the first worm gear 205, and the proximal end of the worm 204 is fixedly connected to the distal end of the transmission shaft 201, such as by welding or fixed pin connection. The proximal end of the transmission shaft 201 is fixedly connected to the distal end of the handle 1. In addition, a first rack structure 331 is provided on one side wall of the first connecting member 33. The extending direction of the first rack structure 331 is the same as the extending direction of the first expanding member 32, and the first rack structure 331 meshes with the first gear 203.

[0032] In this embodiment, when the handle 1 drives the transmission shaft 201 to rotate, the transmission shaft 201 will drive the worm 204 to rotate synchronously. When the worm 204 rotates, it will drive the first worm gear 205 to rotate. When the first worm gear 205 rotates, it will drive the first support shaft 202 and the first gear 203 to rotate. Since the first gear 203 meshes with the first rack structure 331, it will drive the first connecting member 33 and the first expanding member 32 to move. It can be understood that due to the close cooperation relationship among the handle 1, the transmission mechanism 2 and the expanding assembly 3, the expandable test die in this embodiment has a compact structure, a relatively small overall size, is convenient to operate and use, improves the surgical efficiency, shortens the surgical time, and reduces the pain and surgical risk of the patient.

[0033] Reference Figures 1 to 3 As shown in the figure, in some embodiments, the transmission mechanism 2 further includes a first bearing 206 sleeved on the end of the first support shaft 202, and the first bearing 206 is fixedly connected to the main body member 31.

[0034] In this embodiment, an installation structure groove can be provided on the inner side wall of the main body member 31 for installing the first bearing 206. By providing the first bearing 206 at the end of the first support shaft 202 and fixedly connecting the first bearing 206 to the main body member 31, the smoothness of the rotation of the first support shaft 202 is ensured, and at the same time, the torsional failure of the main body member 31 caused by force is avoided.

[0035] It should be noted that in this embodiment, the numbers of the first bearing 206, the first connecting member 33, and the first gear 203 are all two. By setting the numbers of the first bearing 206, the first connecting member 33, and the first gear 203 to two, the stability of the first expanding member 32 during movement is further ensured. Specifically, the first worm gear 205 is sleeved on the middle part of the first support shaft 202 and fixedly connected to the first support shaft 202. The two first bearings 206 are respectively and symmetrically sleeved on the two end parts of the first support shaft 202 and are both fixedly connected to the main body member 31 to further ensure the smoothness of the first support shaft 202 during rotation and also further ensure the stability of the main body member 31. The two first gears 203 are spaced apart and sleeved on the first support shaft 202, and the two first gears 203 are symmetrically arranged on both sides of the first worm gear 205 respectively. The two first connecting members 33 are spaced apart and arranged in the first expanding member 32 and are respectively meshed with a corresponding first gear 203.

[0036] In some embodiments, the numbers of the first bearing 206, the first connecting member 33, and the first gear 203 are all one. Compared with this embodiment, the stability of the expandable test mold provided by this embodiment is a bit worse.

[0037] Refer to Figure 1 、 Figure 2 and Figure 4 As shown in

[0038] In this embodiment, the number of the washers 207 is two, which are respectively sleeved on the two ends of the worm 204 to improve the stability of the worm 204 during rotation. It can be understood that since the washer 207 is slidable, when the worm 204 rotates, the relative sliding between the washer 207 and the worm 204 cancels its axial movement to ensure that the position of the washer 207 remains unchanged all the time.

[0039] In some embodiments, the lead angle of the worm 204 is set to be less than its equivalent friction angle, and the transmission efficiency of the worm 204 is set to be less than 50%.

[0040] In this embodiment, by setting the lead angle of the worm 204 to be less than its equivalent friction angle, the reverse self-locking performance of the worm 204 can be achieved. And in order to further improve the self-locking performance, the transmission efficiency of the worm 204 is set to be less than 50%.

[0041] In some embodiments, in order to further improve the self-locking performance of the worm 204, the transmission ratio i of the worm 204 may be designed to be in the range of 15-50.

[0042] refer to Figure 5 , Figure 6 and Figure 7 As shown, in some embodiments, the expansion assembly 3 further includes a second expansion member 34 and a second connecting member 35, and the second expansion member 34 is movably arranged on the main body 31 and arranged opposite to the first expansion member 32. The second connecting member 35 is located in the second expansion member 34 and is fixedly connected to the second expansion member 34, and the second connecting member 35 and the first connecting member 33 are respectively located on both sides of the first gear 203, and the second connecting member 35 is transmission-connected to the transmission mechanism 2. When the handle 1 rotates, the transmission mechanism 2 applies force to the first expansion member 32 and the second expansion member 34, so that the first expansion member 32 and the second expansion member 34 are moved closer to or away from each other.

[0043] In this embodiment, the structure of the second opening member 34 is the same as that of the first opening member 32, and the inner side wall of the second opening member 34 is also provided with a concave slide groove along its extension direction, and the concave slide groove on the second opening member 34 is adapted to the convex slide groove on the main body 31 to ensure the stability of the second opening member 34 during the sliding process. It should be noted that by adding the second opening member 34, the two-way opening of the test mold is achieved, the adjustable range of the test mold is increased, and the applicability of the test mold is further improved.

[0044] Further, the transmission mechanism 2 further includes a second support shaft 208, a second gear 209 and a second worm gear 210, which are used to transmit power to the second opening member 34. Specifically, the second support shaft 208 is rotatably arranged in the second opening member 34 and is arranged opposite to the first support shaft 202. The second worm gear 210 and the second gear 209 are both sleeved on the second support shaft 208 and fixedly connected to the second support shaft 208, and the second worm gear 210 is arranged corresponding to the first worm gear 205, and the second gear 209 is arranged corresponding to the first gear 203. The distal end of the worm 204 is located between the second worm gear 210 and the first worm gear 205, and the two side walls are respectively meshed with the first worm gear 205 and the second worm gear 210, and the proximal end of the worm 204 is fixedly connected to the distal end of the transmission shaft 201. A second rack structure 351 is arranged on one side wall of the second connecting member 35, and the second rack structure 351 is meshed with the second gear 209.

[0045] In this embodiment, when the handle 1 is rotated, the transmission mechanism 2 can drive the first expanding member 32 and the second expanding member 34 to move in opposite directions simultaneously, so as to realize the expansion and retraction of the expanding assembly 3.

[0046] In some embodiments, the transmission mechanism 2 further includes a second bearing 211 sleeved on the end of the second support shaft 208. The second bearing 211 is symmetrically arranged with the first bearing 206, and the second bearing 211 is fixedly connected to the main body member 31.

[0047] In this embodiment, by arranging the second bearing 211 on the second support shaft 208, the stability of the second support shaft 208 during rotation is ensured.

[0048] Reference Figure 6 and Figure 8 As shown, in some embodiments, the number of the second bearings 211, the second connecting members 35 and the second gears 209 is two. Wherein, the second worm wheel 210 is sleeved on the middle part of the second support shaft 208 and is fixedly connected to the second support shaft 208. The two second bearings 211 are respectively and symmetrically sleeved on the two end parts of the second support shaft 208 and are both fixedly connected to the main body member 31 to further ensure the smoothness of the second support shaft 208 during rotation and also further ensure the stability of the main body member 31. The two second gears 209 are sleeved on the second support shaft 208 at intervals, and the two second gears 209 are respectively arranged symmetrically on both sides of the second worm wheel 210. The two second connecting members 35 are arranged in the second expanding member 34 at intervals and are respectively engaged with a corresponding second gear 209.

[0049] In this embodiment, by setting the number of the second bearings 211, the second connecting members 35 and the second gears 209 to two, the stability of the second expanding member 34 during movement is further ensured.

[0050] Reference Figures 5 to 9 As shown, in some embodiments, a transmission channel 312 is formed on the main body member 31. Specifically, the main body member 31 has a protruding cylindrical structure 311, and the transmission channel 312 is formed on the cylindrical structure 311 and conducts the main body member 31. The transmission shaft 201 is a double universal coupling, and the distal end of the transmission shaft 201 is movably inserted into the transmission channel 312 and fixedly connected to the proximal end of the worm 204.

[0051] In this embodiment, since the transmission shaft 201 is a double universal joint, when the handle 1, the double universal joint, and the expansion assembly 3 have an angle, this angle difference can be compensated so that the double universal joint can achieve continuous power transmission while maintaining a relative positional relationship.

[0052] Furthermore, a first notch 321 is formed on a side wall of the first opening member 32 close to the transmission channel 312, and a second notch 341 is formed on a side wall of the second opening member 34 close to the transmission channel 312. When the first opening member 32 and the second opening member 34 are close to each other, the diameter of the area formed by the first notch 321 and the second notch 341 is larger than the diameter of the transmission channel 312.

[0053] It is understandable that, since the transmission channel 312 is opened on the cylindrical structure 311, in order to prevent the first opening member 32 and the second opening member 34 from being affected by the cylindrical structure 311 when they are brought close to each other, the first opening member 32 is provided with the first notch 321 on one side wall close to the transmission channel 312, and the second opening member 34 is provided with the second notch 341 on one side wall close to the transmission channel 312, and the diameter of the area where the first notch 321 and the second notch 341 match can be adapted to the cylindrical structure 311. In this way, when the first opening member 32 and the second opening member 34 are brought close to each other and closed, the internal parts thereof can be prevented from accidentally falling off when the trial mold is placed in and taken out, thereby improving the safety of the operation.

[0054] In some embodiments, the side walls of the first connecting member 33 and the second connecting member 35 are partially provided with scale distance marks. The first opening member 32, the second opening member 34 and the main member 31 are provided with visual windows 36 corresponding to the scale distance marks.

[0055] In this embodiment, medical personnel can directly read the moving distances of the first propping member 32 and the second propping member 34 according to the visual window 36 during the operation, so as to facilitate rapid and accurate measurement during the operation.

[0056] In some embodiments, the handle 1 includes a grip portion 11, a connecting rod 12, and a rotating portion 13. The grip portion 11 is a hollow structure, the transmission shaft 201 is movably disposed in the grip portion 11, the proximal end of the transmission shaft 201 is fixedly connected to the distal end of the connecting rod 12, and the rotating portion 13 is a ratchet handle, and the distal end of the ratchet handle is fixedly connected to the proximal end of the connecting rod 12.

[0057] In this embodiment, the gripping portion 11 plays a gripping role. The gripping portion 11 is sleeved on the transmission shaft 201. The surface of the gripping portion 11 is designed with concave and convex features to meet the human hand gripping habits. The distal end of the gripping portion 11 has a hexagonal circumferential arc, which can contact and cooperate with the support component 3 without slipping. The hollow structure of the gripping portion 11 is a hexagonal deep hole, which can completely accommodate the transmission shaft 201. When the gripping portion 11 completely accommodates the transmission shaft 201, it can be regarded as an integrated connecting rod, such as Figure 10 When the gripping portion 11 is pushed back to completely expose the transmission shaft 201, since the transmission shaft 201 is a double universal coupling, the spreading assembly 3 can move and spread along with the vertebral body within a certain taper range, as shown in FIG. Figure 5 As shown, the surgical incision area is effectively reduced.

[0058] In addition, it should be noted that the ratchet handle in this embodiment is a common ratchet mechanism, which is mainly composed of a ratchet, a pawl, a spring, a baffle and a handle 1. The specific combination and connection method is not described in detail here. When the ratchet handle rotates, the pawl is clamped into the tooth groove of the ratchet under the action of the spring, forming a temporary locking structure to prevent the ratchet handle from rotating by itself without force, so that the ratchet handle has a self-locking function.

[0059] The above is only a specific implementation of the embodiment of the present application, but the protection scope of the embodiment of the present application is not limited thereto, and any changes or replacements within the technical scope disclosed in the embodiment of the present application should be included in the protection scope of the embodiment of the present application. Therefore, the protection scope of the embodiment of the present application should be based on the protection scope of the claims.

Claims

1. A test mold that can be expanded, characterized in that: include: handle; A transmission mechanism, the proximal end of which is connected to the handle; A spreading component connected to the distal end of the transmission mechanism, the spreading component comprising a main body and a first spreading member movably arranged on the main body; When the handle rotates, a force is applied to the first spreading member through the transmission mechanism, so that the first spreading member and the main body member are moved closer to each other or farther away from each other.

2. The expandable trial mold according to claim 1, characterized in that: The expansion assembly further includes a first connecting member located in the first expansion member and fixedly connected to the first expansion member, and the first connecting member is transmission-connected to the transmission mechanism.

3. The expandable trial mold according to claim 2, characterized in that: The transmission mechanism includes a transmission shaft, a first support shaft, a first gear, a worm and a first worm wheel; The first support shaft is rotatably disposed in the first support member; The first worm wheel and the first gear are both sleeved on the first support shaft and fixedly connected to the first support shaft; The worm is meshed with the first worm wheel, and the proximal end of the worm is fixedly connected to the distal end of the transmission shaft; The proximal end of the transmission shaft is fixedly connected to the distal end of the handle; A first rack structure is disposed on one side wall of the first connecting member, and the first rack structure is meshed with the first gear.

4. The expandable trial mold according to claim 3, characterized in that: The transmission mechanism further includes a first bearing sleeved on the end of the first support shaft, and the first bearing is fixedly connected to the main body.

5. The expandable trial mold according to claim 4, characterized in that: The number of the first bearing, the first connecting member and the first gear are all two; The two first bearings are respectively sleeved on the two ends of the first support shaft and are fixedly connected to the main body; Two first gears are sleeved on the first supporting shaft at intervals; The two first connecting members are arranged in the first opening member at intervals and are respectively meshed with a corresponding one of the first gears.

6. The expandable trial mold according to claim 3, characterized in that: The transmission mechanism further comprises at least one washer, and the washer is slidably sleeved on the end of the worm; When the worm rotates, the washer remains stationary.

7. The expandable trial mold according to claim 3, characterized in that: The lead angle of the worm is set to be smaller than its equivalent friction angle, and the transmission efficiency of the worm is less than 50%.

8. The expandable trial mold according to any one of claims 3 to 7, characterized in that: The expansion assembly further includes a second expansion member and a second connecting member; The second opening member is movably disposed on the main body and is disposed opposite to the first opening member; The second connecting member is located in the second opening member and is fixedly connected to the second opening member, and the second connecting member is in transmission connection with the transmission mechanism; When the handle rotates, force is applied to the first and second spreading members through the transmission mechanism, so that the first and second spreading members are moved closer to or farther from each other.

9. The expandable trial mold according to claim 8, characterized in that: The transmission mechanism also includes a second support shaft, a second gear and a second worm gear; The second support shaft is rotatably disposed in the second support member and is disposed opposite to the first support shaft; The second worm gear and the second gear are both sleeved on the second support shaft and fixedly connected to the second support shaft; The distal end of the worm is meshed with the second worm wheel, and the proximal end of the worm is fixedly connected with the distal end of the transmission shaft; A second rack structure is disposed on one side wall of the second connecting member, and the second rack structure is meshed with the second gear.

10. The expandable trial mold according to claim 9, characterized in that: The transmission mechanism further comprises a second bearing sleeved on the end of the second support shaft, and the second bearing is fixedly connected to the main body.

11. The expandable trial mold according to claim 10, characterized in that: The number of the second bearing, the second connecting member and the second gear is two; The two second bearings are respectively sleeved on the two ends of the second support shaft and are both fixedly connected to the main body; Two second gears are sleeved on the second supporting shaft at intervals; Two second connecting members are arranged in the second opening member at intervals and are respectively meshed with a corresponding second gear.

12. The expandable trial mold according to claim 3, characterized in that: The main body is provided with a transmission channel; The transmission shaft is a double universal coupling, and the distal end of the transmission shaft is movably arranged in the transmission channel and is fixedly connected to the proximal end of the worm.

13. The expandable trial mold according to claim 12, characterized in that: A first notch is formed on a side wall of the first support member close to the transmission channel, and a second notch is formed on a side wall of the second support member close to the transmission channel; When the first support member and the second support member are close to each other, the diameter of the area formed by the cooperation of the first notch and the second notch is larger than the diameter of the transmission channel, and the first notch and the second notch are closed to surround the transmission channel.

14. The expandable trial mold according to claim 8, characterized in that: Part of the side walls of the first connecting member and the second connecting member are provided with distance marks; The first propping member, the second propping member and the main body are provided with visible windows corresponding to the distance marks.

15. The expandable trial mold according to claim 3, characterized in that: The handle comprises a gripping portion, a connecting rod and a rotating portion; The gripping portion is a hollow structure; The transmission shaft is movably inserted into the gripping portion, and the proximal end of the transmission shaft is fixedly connected to the distal end of the connecting rod; The rotating part is a ratchet handle, and the distal end of the ratchet handle is fixedly connected to the proximal end of the connecting rod.

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