Head fixing device

Abstract

The invention relates to a head fixing device, and belongs to the technical field of head fixing frames, the head fixing device comprises three head nails which are arranged in an annular array and used for extruding the head, each head nail is axially and movably installed in a corresponding jacking column, and a rubber cushion block is fixed to the end, facing the center of the array, of each jacking column; the abutting columns are axially installed on the end face of an installation ring in a sliding mode, a plurality of sliding seats are further fixed to the end face of the installation ring in an annular array mode, a driving ring is rotatably installed on the sliding seats, and flat threads are arranged on the end faces, making contact with each other, of the driving ring and the installation ring so that when the driving ring rotates, all the abutting columns move synchronously in the axial direction. All the rubber cushion blocks push the head to the central position of the mounting ring; and the nail head of the head nail can axially and slidably extend out of the rubber cushion block to be in contact with the cortical bone of the skull. The head can be conveniently, efficiently, safely and effectively fixed.

Description

Technical Field

[0001] The invention relates to the technical field of head fixing frames, and in particular to a head fixing device. Background Art

[0002] The existing neurosurgical headframe is also called a cranial surgery headframe or head fixation frame. It is a device specifically used for neurosurgery, mainly used to fix the patient's head to ensure the stability and precision of the surgical area. This headframe plays a vital role in the operation. It is usually connected to the operating table to ensure that the patient's head remains stable during the operation, which can greatly improve the accuracy and safety of the operation. It can also be used in conjunction with the brain traction system to further fix and adjust the patient's head position, which is particularly important in cranial surgery.

[0003] The most common existing head fixation frame is the three-top head fixation frame, which uses three head pins in a circular array to be inserted into the patient's head, contacting the cortical bone of the skull, and then preventing the head from moving. This positioning method requires manual movement of the head to the exact position in the early stage, that is, medical staff need to move the head many times, adjust the position, and even manually mark lines on the patient's head, and then drive the three head pins to move axially to surround the head and fix the head. This is very troublesome, and once the initial position of the head is not accurate, or the depth of the insertion of the three head pins is inaccurate, either the patient's head will be seriously injured due to the insertion of the head pins, or one or two of the insertion depths will be obviously insufficient, and there will be no sufficient compression contact with the cortical bone, resulting in head displacement in subsequent operations. Therefore, in clinical practice, the head pins can only be adjusted slowly and manually, relying entirely on the operator's experience level.

[0004] In addition, in the prior art, the head frame uses a head pin, which is a lossy positioning element, to fix the head because it is not feasible to directly use some instruments to press against the scalp to fix the head, because the skull and scalp can easily slide relative to each other when squeezed, thereby causing the skull to move. Therefore, the head pin is used for fixation. However, as a traumatic fixation device, the head pin itself will slightly enter the patient's head. Therefore, the existing head fixation device is relatively cumbersome in terms of the placement of the head to match the position of the head frame in the early stage of head fixation, and it is also difficult to accurately control the depth of the head pin inserted into the head. Both efficiency and safety need to be further improved. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a head fixing device to solve the problem that the head fixing equipment in the prior art is inconvenient to operate and lacks safety and controllability when fixing the head.

[0006] The present invention is achieved through the following technical solutions:

[0007] A head fixing device, comprising three annular arrays of head nails for squeezing the head, each of the head nails being axially movably mounted in a corresponding tightening column, and a rubber pad being fixed at one end of each tightening column toward the center of the array;

[0008] The tightening column is axially slidably installed on the end face of a mounting ring, and a plurality of slide seats are fixed in a circular array on the end face of the mounting ring. The slide seat is used for rotatable installation of an active ring, and flat threads are provided on the end faces of the active ring and the mounting ring that contact each other, so that when the active ring rotates, all the tightening columns move axially synchronously to make all the rubber pads push the heads to the central position of the mounting ring; the nail head of the head nail can axially slide out of the rubber pad and contact the cortical bone of the skull.

[0009] Furthermore, the surface of the slide seat has an arc-shaped strip-shaped slide groove, and the bottom end surface of the active ring is installed in the strip-shaped slide groove in a sliding fit.

[0010] Furthermore, an operating handle is provided on one side of the active ring, and an outer side of the active ring is coaxially provided with an outer gear ring, and the outer gear ring is drivingly connected to the main shaft of the micro motor.

[0011] Furthermore, a cylindrical through hole is provided in the center of the rubber pad, and the cylindrical through hole can allow the nail head of the head nail to freely pass axially.

[0012] Furthermore, the tightening column has an axial mounting hole, and the head nail is axially movably mounted in the mounting hole; the head nail comprises a nail head section, a middle section and a nail tail section which are arranged in sequence, the nail tail section is connected to the pushing element for axial movement, the diameter of the middle section is larger than the other two sections, and an insulating tube is embedded and fixed on the inner side of the middle section close to the cylindrical surface, a sliding groove is provided on the upper side surface of the insulating tube along the length direction, a conductive rod is inserted in the insulating tube, a conductive key is protrudingly fixed on the inner side wall of the mounting hole, and the conductive key passes through a groove on the surface of the middle shaft and then passes through the sliding groove to maintain sliding contact with the conductive rod;

[0013] A conductive sleeve is provided in the port of the mounting hole near one end of the elastic pad. When the head nail axially extends out of the elastic pad, the end of the conductive rod is squeezed into contact with the end of the conductive sleeve, so that a power supply circuit that controls the start and stop of the pushing element is disconnected. At this time, the nail head of the head nail just reaches the position in contact with the cortical bone of the skull.

[0014] Furthermore, the insulating tube is a screw-shaped structure, and the insulating tube is threadably mounted on a step surface formed between the middle section and the head nail section.

[0015] Furthermore, the end of the conductive rod is a cylindrical structure, and its diameter is larger than that of the remaining rod sections, and the end of the conductive rod extends out of the step surface; the conductive sleeve is axially slidably fitted on a conductive plug with a T-shaped longitudinal section, and is elastically connected to the conductive plug, and the conductive plug and the conductive sleeve are both installed in an insulating base, and the insulating base is embedded and fixed in the mounting hole, and when the step surface contacts the positioning step at one end of the mounting hole near the rubber pad, the end of the conductive rod is inserted into the insulating base, and the conductive sleeve is further pressed into the insulating base.

[0016] Furthermore, the present invention also includes a positioning sleeve axially slidably installed in the mounting hole near the positioning step, the positioning sleeve has a connecting plate at one end outside the mounting hole, and a plurality of locking bolts are arranged in an annular array on the connecting plate and screwed into the end face of the tightening column, the end of the locking bolt has a cylindrical gear, and a positioning shaft ring is also fixed near the cylindrical gear, the positioning shaft ring is rotatably installed on the end face of the connecting plate, all the cylindrical gears are meshed with an inner gear ring rotatably installed on the end face of the tightening column, so that when the inner gear ring is rotated, all the locking bolts synchronously push the connecting plate to move axially, so that the end of the positioning sleeve facing the step surface moves to the set position and contacts with the step surface for positioning.

[0017] Furthermore, there are several sliding screws in an annular array on the inner gear ring, and the nuts of the sliding screws are slidably installed in an annular groove. The annular groove is opened on the end face of the tightening column, so that after loosening the nut on the sliding screw, it can be rotated according to the inner gear ring, so that all cylindrical gears can rotate synchronously.

[0018] Furthermore, the pushing element includes a driving stud that rotates with the nail tail section but does not separate from each other. The driving stud is threadedly installed in the installation hole. A driving motor is installed on one end of the driving stud located outside the tightening column. The opening and closing of the driving motor is controlled by the power supply circuit.

[0019] The beneficial effects of the present invention are:

[0020] The head fixing device adjusts the head to an initial position, i.e., the center of the mounting ring, in advance through a tightening column provided with a rubber pad, and then inserts each head pin beyond the end of the tightening column into the head to contact the cortical bone of the skull, thereby positioning the head, thereby preventing the problem of the skull slipping relative to the scalp during later operations, which may occur if the scalp is simply squeezed to fix the head. The device also avoids the difficulty in quickly controlling the position of the head when the head pin is directly inserted into the head in the prior art, and the difficulty in pre-positioning the head. It can also avoid the deviation of the insertion point due to slight shaking of the head when inserting the head, which may require multiple attempts to position the head, causing more injuries to the patient, and insufficient safety in use, especially requiring extremely high experience of the operator.

[0021] In more detail, in the present invention, due to the pre-adjustment of the position of the head by the telescopic column, the pre-contact positioning of the rubber pad and the head, relatively speaking, the distance of the head nail extending out of the rubber pad can be controlled more accurately, because the rubber pad itself has a certain positioning effect. Moreover, because the head is not a regular circle after all, therefore, when centering, the rubber pad itself has a certain elasticity, which allows the force of some tightening columns to be greater than that of the other tightening columns when the head is initially pre-positioned and clamped, thereby more fully ensuring that the rubber pad is in compression contact with the head, and better preparing for the insertion of the head nail.

[0022] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A front view of the present invention;

[0024] Figure 2 A longitudinal cross-sectional schematic diagram of the tightening column in the present invention;

[0025] Figure 3 for Figure 2 A schematic diagram of an enlarged structure at A in the middle;

[0026] Figure 4 for Figure 2 A schematic diagram of an enlarged structure at B in the figure.

[0027] In the figure: head nail 1, nail head section 101, middle section 102, nail tail section 103, mounting ring 2, active ring 3, tightening column 4, mounting hole 401, rubber pad 5, operating handle 6, slide seat 7, drive motor 8, conductive key 9, sliding groove 10, conductive rod 11, insulating tube 12, conductive sleeve 13, conductive bolt 14, insulating seat 15, positioning step 16, positioning sleeve 17, connecting plate 18, cylindrical gear 19, positioning shaft ring 20, inner gear ring 21, locking bolt 22, nut 23, nut 24, drive stud 25. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0031] See also Figure 1 , the present invention provides a technical solution: a head fixing device, which, in terms of its specific structure, mainly includes three head pins 1 in an annular array, which are specially used for squeezing the head, that is, the function is similar to the head pins 1 of the traditional head frame. The key is that each head pin 1 in the present embodiment is axially movably installed in a corresponding tightening column 4, and a rubber pad 5 is fixed to one end of each tightening column 4 facing the center of the array. The rubber pad 5 has a certain elasticity and is mainly used to contact with the head to move the head to adjust the position. During this initial adjustment process, no loss will be caused to the head and the patient will not feel uncomfortable. At the same time, the tightening column 4 in the present embodiment is axially slidably installed on the end face of a mounting ring 2. Specifically, a plurality of slide seats 7 are also fixed in an annular array on the end face of the mounting ring 2, such as Figure 1These slide seats 7 are used for rotatable installation of an active ring 3, so that when the active ring 3 rotates, it can rotate around the axis of the mounting ring 2, and flat threads are provided on the end faces of the active ring 3 and the mounting ring 2 that contact each other. Through the special design of the flat threads, when the active ring 3 rotates under the drive of external force, all the tightening columns 4 can move axially synchronously, so that all the rubber pads 5 can push the head to move, and finally push the head to the central position of the mounting ring 2, so as to achieve pre-positioning of the head, and there will be no harm in this process. Then, on this preliminary positioning extrusion, the nail head of the head nail 1 is axially slidably extended out of the rubber pad 5, so as to contact the cortical bone of the skull, so as to achieve the purpose of fixing the head and avoid the problem of loose fixation due to easy sliding between the scalp and the exposed bone. In actual production, the surface of the slide seat 7 has an arc-shaped strip groove, and the bottom end surface of the active ring 3 is slidably mounted in the strip groove. In order to facilitate rotation, an operating handle 6 can be provided on one side of the active ring 3 to realize manual operation. In addition, the outer side of the active ring 3 also has an outer gear ring (not shown in the figure) coaxially, and the outer gear ring is connected to the main shaft of the micro motor to realize automatic adjustment. In addition, in production, if Figure 2 The center of the rubber pad 5 has a cylindrical through hole, through which the nail head of the head nail 1 can freely pass axially. Then, after the head is pre-fixed by the rubber pad 5, the head nail 1 is more likely to directly contact the exposed cortical bone and fix the head.

[0032] like Figure 2-3 As shown, in this embodiment, the tightening column 4 has an axial mounting hole 401, and the head nail 1 is axially mounted in the mounting hole 401, and the head nail 1 includes a head section 101, a middle section 102 and a tail section 103 arranged in sequence, wherein the tail section 103 is connected to a pushing element, and the pushing element can be an electrically controlled starter or hydraulic device to control the axial movement of the head nail 1. The diameter of the middle section 102 of the head nail 1 is larger than that of the other two sections, thereby forming a corresponding step surface, and as shown in FIG. Figure 2 An insulating tube 12 is embedded and fixed inside the middle section 102 near the cylindrical surface. In practice, the insulating tube 12 can be a screw-shaped structure, which is easy to install on the middle section 102 for quick disassembly. Specifically, the insulating tube 12 is threadedly installed on the corresponding step surface formed between the middle section 102 and the head nail 1. On the upper surface of the insulating tube 12, a sliding groove 10 is provided along the length direction. A conductive rod 11 is inserted into the insulating tube 12. The conductive rod 11 can conduct electricity. At the same time, a conductive key 9 is protrudingly fixed on the inner wall of the mounting hole 401. This conductive key 9 can conduct electricity and can be connected to the corresponding wire (for example Figure 2The conductive key 9 passes through a groove on the surface of the middle shaft, and then passes through the sliding groove 10 to maintain sliding contact with the conductive rod 11, so that the head nail 1 always maintains electrical connection with the corresponding wire during the axial movement. In addition, a conductive sleeve 13 is required to be provided in the port of the mounting hole 401 near the end of the elastic pad. In the specific production, similarly, this conductive sleeve 13 is also connected to the corresponding wire. In use, when the head nail 1 axially extends out of the elastic pad, the end of the conductive rod 11 is squeezed and contacted with the end of the conductive sleeve 13, so that a power supply circuit that controls the start and stop of the driving element is disconnected. Once the circuit is disconnected, the driving element stops working and the head nail 1 stops moving immediately. At this time, the nail head of the head nail 1 can just reach the position of contacting the cortical bone of the skull to achieve fixation of the head, and the fixing force is highly controlled to avoid excessive damage to the head.

[0033] In this embodiment: Figure 3 The end of the conductive rod 11 is a cylindrical structure, and its diameter is larger than the other rod segments. The end of the conductive rod 11 extends out of the step surface. At the same time, the conductive sleeve 13 is axially slidably fitted on a conductive plug 14 with a T-shaped longitudinal section, and is elastically connected to the conductive plug 14. Specifically, it can be elastically connected through a cylindrical spring. The conductive plug 14 and the conductive sleeve 13 are both installed in an insulating base. The conductive plug 14 is as shown in FIG. Figure 2-3 In more detail, the insulating base is embedded and fixed in the mounting hole 401, and the step surface formed by the nail head section 101 and the middle section 102 of the head nail 1 stops moving when it contacts the positioning step 16 at one end of the mounting hole 401 near the rubber pad 5. At this time, the end of the conductive rod 11 is inserted into the insulating base, and the conductive sleeve 13 is further pressed into the insulating base to realize the conduction of the above-mentioned power supply circuit.

[0034] In this embodiment: Figure 2 and Figure 4The inside of the jacking column 4 also includes a positioning sleeve 17 that is axially slidably installed at the mounting hole 401 near the positioning step 16. The positioning sleeve 17 is located at one end outside the mounting hole 401, and is integrally provided with a connecting plate 18. A plurality of locking bolts 22 are arranged in a circular array on the connecting plate 18. These locking bolts 22 pass through the connecting plate 18 and are screwed into the end face of the jacking column 4. The length of the locking bolts 22 is sufficient to always be in the jacking column 4 without being disengaged. At the same time, a cylindrical gear 19 must be coaxially fixed to the end of the locking bolt 22. A positioning collar 20 is also fixed near the cylindrical gear 19. The positioning collar 20 is rotatably installed on the end face of the connecting plate 18 and can drive the connecting plate 18 to move axially. All cylindrical gears 19 are meshed with an inner gear ring 21 rotatably installed on the end face of the jacking column 4, so that when the inner gear ring 21 is rotated, all the locking bolts 22 move synchronously with the threads, thereby pushing the connecting plate 18 to move axially, so that the positioning sleeve 17 can move axially well and avoid the movement of each locking bolt 22. Due to the different distances, the end face of the positioning sleeve 17 is not in the set plane, for example, not in the vertical plane, resulting in errors in contact and positioning with the above-mentioned step surface. However, through the design structure, the end of the positioning sleeve 17 facing the step surface can be moved to the set position, so that it can accurately fit with the step surface for contact and positioning. In addition, if the positioning sleeve 17 is to move axially, the locking bolt 22 must also move axially, and the locking bolt 22 must be rotated. However, due to the limitation of the inner gear ring 21, it cannot rotate, thereby achieving the key role of firmly and accurately installing and positioning the positioning sleeve 17. In order to fix the inner gear ring 21, in this embodiment, Figure 4 As shown, a plurality of sliding screws can be arranged in an annular array on the inner gear ring 21, and the nuts 24 of these sliding screws are slidably mounted in an annular groove, and this annular groove is provided on the end face of the tightening column 4, so that after slightly loosening the nut 23 on the sliding screw, the inner gear ring 21 can be pressed to rotate, so that all the cylindrical gears 19 can rotate synchronously, and when the positioning sleeve 17 is pushed into place, the nut 23 is tightened to fix the inner gear ring 21, and the structure is simple and ingenious.

[0035] Finally, in the above embodiments, the driving element is as follows Figure 1-2 As shown, it mainly includes a driving stud 25 that rotates with the nail tail section 103 but does not separate from each other. The driving stud 25 is threadedly installed in the mounting hole 401 and moves axially in the form of a threaded pair to drive the head nail 1 to move. The driving stud 25 mentioned above can be installed with one end located outside the tightening column 4, and a driving motor 8 is installed for transmission. The opening and closing of the driving motor 8 is controlled by the power supply circuit, and then when the extension length of the head nail 1 is controlled by the positioning sleeve 17, it is indirectly achieved by controlling the start and stop of the driving motor 8.

[0036] In the above description of the present invention, it should be noted that the terms "one side", "the other side", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply 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 limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0037] In addition, the term "same" does not mean that the parts must be absolutely the same, but slight differences are allowed. The term "vertical" only means that the positional relationship between the parts is more vertical than "parallel", and does not mean that the structure must be completely vertical, but can be slightly tilted.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A head fixing device, comprising three head pins (1) in an annular array for squeezing the head, characterized in that: Each of the head nails (1) is axially movably installed in a corresponding tightening column (4), and a rubber pad (5) is fixed to one end of each tightening column (4) facing the center of the array; The tightening column (4) is axially slidably mounted on the end face of a mounting ring (2), and a plurality of slide seats (7) are fixed in a circular array on the end face of the mounting ring (2). The slide seat (7) is provided for rotational mounting of an active ring (3), and flat threads are provided on the end faces of the active ring (3) and the mounting ring (2) that contact each other, so that when the active ring (3) rotates, all the tightening columns (4) move axially synchronously, so that all the rubber pads (5) push their heads to the central position of the mounting ring (2); the nail head of the head nail (1) can axially slide out of the rubber pad (5) and contact the cortical bone of the skull.

2. The head fixing device according to claim 1, characterized in that: The surface of the slide seat (7) has an arc-shaped strip-shaped slide groove, and the bottom end surface of the active ring (3) is installed in the strip-shaped slide groove in a sliding manner.

3. The head fixing device according to claim 1, characterized in that: An operating handle (6) is provided on one side of the active ring (3), and an outer side of the active ring (3) is also coaxially provided with an outer gear ring, which is transmission-connected to the main shaft of the micro motor.

4. The head fixing device according to claim 1, characterized in that: The rubber pad (5) has a cylindrical through hole at its center, and the cylindrical through hole allows the nail head of the head nail (1) to freely pass axially through the hole.

5. The head fixing device according to claim 1, characterized in that: The tightening column (4) has an axial mounting hole (401), and the head nail (1) is axially movably mounted in the mounting hole (401); the head nail (1) comprises a nail head section (101), a middle section (102) and a nail tail section (103) which are arranged in sequence, and the nail tail section (103) is connected to the pushing element for axial movement, the diameter of the middle section (102) is larger than that of the other two sections, and an insulating tube (12) is embedded and fixed on the inner side of the cylindrical surface of the middle section (102), and a sliding groove (10) is provided on the upper side surface of the insulating tube (12) along the length direction, and a conductive rod (11) is inserted into the insulating tube (12), and a conductive key (9) is protrudingly fixed on the inner side wall of the mounting hole (401), and after the conductive key (9) passes through a groove on the surface of the middle shaft, it passes through the sliding groove (10) and maintains sliding contact with the conductive rod (11); A conductive sleeve (13) is provided in the port of the mounting hole (401) near one end of the elastic pad. When the head nail (1) extends axially out of the elastic pad, the end of the conductive rod (11) is squeezed into contact with the end of the conductive sleeve (13), so that a power supply circuit for controlling the start and stop of the pushing element is disconnected. At this time, the nail head of the head nail (1) just reaches the position in contact with the cortical bone of the skull.

6. The head fixing device according to claim 5, characterized in that: The insulating tube (12) is a screw-shaped structure, and the insulating tube (12) is threadably mounted on a step surface formed between the middle section (102) and the head nail (1) section.

7. The head fixing device according to claim 6, characterized in that: The end of the conductive rod (11) is a cylindrical structure, and its diameter is larger than that of the remaining rod sections, and the end of the conductive rod (11) extends out of the step surface; the conductive sleeve (13) is axially slidably fitted on a conductive bolt (14) with a T-shaped longitudinal section, and is elastically connected to the conductive bolt (14); the conductive bolt (14) and the conductive sleeve (13) are both installed in an insulating base, and the insulating base is embedded and fixed in the mounting hole (401); when the step surface contacts the positioning step (16) at one end of the mounting hole (401) by the rubber pad (5), the end of the conductive rod (11) is inserted into the insulating base, and the conductive sleeve (13) is further pressed into the insulating base.

8. The head fixing device according to claim 7, characterized in that: The invention also comprises a positioning sleeve (17) axially slidably mounted on the mounting hole (401) near the positioning step (16); the positioning sleeve (17) has a connecting plate (18) at one end outside the mounting hole (401); a plurality of locking bolts (22) are arranged in an annular array on the connecting plate (18) and are screwed into the end face of the tightening column (4); the end of the locking bolt (22) has a cylindrical gear (19); a positioning collar (20) is fixed near the cylindrical gear (19); the positioning collar (20) is rotatably mounted on the end face of the connecting plate (18); all cylindrical gears (19) are meshed with an inner gear ring (21) rotatably mounted on the end face of the tightening column (4); when the inner gear ring (21) is rotated, all locking bolts (22) synchronously push the connecting plate (18) to move axially, so that the end of the positioning sleeve (17) facing the step face moves to a set position and contacts the step face for positioning.

9. The head fixing device according to claim 8, characterized in that: The inner gear ring (21) has a plurality of sliding screws in an annular array, and the nuts (24) of the sliding screws are slidably mounted in an annular groove, and the annular groove is provided on the end surface of the tightening column (4), so that after the nuts (23) on the sliding screws are loosened, they are rotated in accordance with the inner gear ring (21), so that all cylindrical gears (19) can rotate synchronously.

10. The head fixing device according to claim 5, characterized in that: The pushing element comprises a driving stud (25) which is rotationally matched with the nail tail section (103) but does not separate from each other. The driving stud (25) is threadedly mounted in the mounting hole (401). A driving motor (8) is transmission-mounted on one end of the driving stud (25) located outside the tightening column (4). The opening and closing of the driving motor (8) is controlled by the power supply circuit.

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