Medical plaster saw

Abstract

This utility model discloses a medical plaster saw, which includes: a swing head assembly, a positioning seat, and a main body, connected sequentially along the Y direction; a saw blade is disposed on the saw blade shaft and located outside the swing head assembly, the saw blade shaft is rotatably mounted inside the swing head assembly, a section of the saw blade shaft facing the main body, a saw blade shaft seat, and a driven ball are connected sequentially; a preset distance is formed between the driven ball and the axis of the saw blade shaft along the X direction; the driven ball contacts the two side walls of an annular groove on a disc, and forms a rotational gap with the inner wall of the swing head assembly; the disc is sleeved on a fixing pin, the fixing pin is fixed to the swing head assembly and extends along the X direction; and a driving ball is eccentrically disposed at the end of a motor shaft and contacts the two side walls of an annular groove on the disc; the motor shaft is rotatably disposed on the positioning seat and extends into the main body along the Y direction; the axis of the motor shaft is coaxial with the axis of the saw blade shaft. The main body of this utility model is coaxial with the axis of the saw blade shaft, thus not obstructing the doctor's view during operation.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, and in particular relates to a medical plaster saw. Background Technology

[0002] Plaster saws are used to remove plaster casts from limbs after recovery from fractures and other injuries. Existing plaster saws have a large size due to the parallel arrangement of the handle and the saw blade axis, which can obstruct the doctor's view and prevent the cutting of specific areas (such as the inside of a bent arm). To solve these problems, an eccentric ball-operated plaster saw has been invented, with the handle and saw blade mounting axis coaxial, thus not obstructing the doctor's view. Utility Model Content

[0003] The purpose of this utility model is to provide a medical plaster saw, in which the handle of the oscillating saw is coaxial with the axis of the saw blade mounting shaft, thus not obstructing the doctor's view during operation. The technical solution adopted is as follows:

[0004] A medical plaster saw, comprising:

[0005] The oscillating head assembly 13, the positioning seat, and the main body 1 are connected sequentially along the Y direction;

[0006] A saw blade 12 is disposed on a saw blade shaft 11 and located outside the swing head assembly 13. The saw blade shaft 11 is rotatably mounted inside the swing head assembly 13. A section of the saw blade shaft 11 facing the main body 1, a saw blade shaft seat 10, and a driven ball 9 are connected in sequence. A preset distance is formed between the driven ball 9 and the axis of the saw blade shaft 11 along the X direction. The driven ball 9 contacts the two side walls of the annular groove opened on the disc 6 and forms a rotational gap with the inner wall of the swing head assembly 13.

[0007] The disc 6 is used to drive the driven ball 9 to rotate around the axis of the saw blade shaft 11. It is sleeved on the fixing pin 8, which is located on the swing head assembly 13 and extends along the X direction.

[0008] The active ball 5 is eccentrically located at the end of the motor shaft 4 and contacts the two side walls of the annular groove on the disc 6; the motor shaft 4 is rotatably mounted on the positioning seat and extends into the main body 1 along the Y direction; the motor corresponding to the motor shaft 4 is located inside the main body 1.

[0009] The axis of the motor shaft 4 is coaxial with the axis of the saw blade shaft 11.

[0010] Preferably, the head-swinging assembly 13 includes:

[0011] A first installation channel and a second installation channel extend along the Y direction and are connected; the first installation channel is used to install the saw blade shaft 11 and is open at one end facing the saw blade 12; the second installation channel is used to install the saw blade shaft seat 10, the driven ball 9 and the disc 6;

[0012] And a pin hole extending along the X direction for installing a fixing pin 8, wherein the fixing pin 8 is interference-fitted with the pin hole; the pin hole is connected to the second installation channel.

[0013] Preferably, a bearing cover, a bearing, a transition cylinder, a bearing, and a bearing cover are sequentially arranged in the first installation channel.

[0014] The first bearing cover is interference-fitted with the swing head assembly 13, and the second bearing cover is placed on the step, which is formed between the first installation channel and the second installation channel. One end of the saw blade shaft 11 is located outside the first bearing cover, and the other end passes through the first bearing, the transition cylinder, the second bearing, and the second bearing cover in sequence, and extends toward the second installation channel.

[0015] Preferably, the positioning seat has a third mounting channel that corresponds to the second mounting channel and is used to install the motor shaft 4;

[0016] A sealing ring is installed on the inner wall of the No. 3 installation channel, and a No. 3 bearing is installed in the sealing ring. The No. 3 bearing is placed on the shoulder of the motor shaft 4.

[0017] Preferably, an axial fixing piece 7 is engaged between the second installation channel and the disk 6, and the fixing pin 8 passes through the axial fixing piece 7. Both of the axial fixing pieces 7 are in contact with the disk 6, and the side of the axial fixing piece 7 facing the disk 6 is flat to fit the disk 6.

[0018] Preferably, the saw blade shaft 11 is fitted inside the saw blade shaft seat 10, and the side of the saw blade shaft seat 10 facing the disc 6 is an inclined surface. A driven ball 9 is installed on the inclined surface, forming an angle with the axis of the saw blade shaft 11.

[0019] Preferably, both the active ball 5 and the driven ball 9 are tangent to the two side walls of the annular groove.

[0020] Preferably, the motor shaft 4 is fixed to the inner wall of the main body 1.

[0021] A design method for a medical plaster saw, based on the aforementioned medical oscillating saw, includes the step of designing the oscillation angle of the saw blade 12, specifically including:

[0022] Step 1A: Mark two points on an adult's skin and measure the distance L1 between the two points under normal conditions;

[0023] Then, pull the skin until pain is felt, and measure the distance L2 between the two points again.

[0024] Preliminary determination of skin elasticity: C1 = L2 - L1;

[0025] Step 1B: Considering the skin elasticity of all population groups, multiply the skin elasticity obtained in Step 1A by a safety factor to obtain the final skin elasticity C2 = a * C1; 0 < a < 1;

[0026] Step 1C: Calculate the central angle corresponding to the arc length C2 according to the formula for calculating the diameter and arc length of the saw blade 12; the central angle is the rotation angle of the saw blade 12.

[0027] Step 1D: The swing angle of saw blade 12 is the rotation angle / 2.

[0028] Compared with the prior art, the advantages of this utility model are:

[0029] 1. The layout of the oscillating head assembly and the main body (motor) axis is coaxial, which enables the coaxial bias ball to drive the saw blade shaft to make high-frequency small-angle reciprocating motion around the saw blade axis. This does not obstruct the operator's field of vision for sawing and makes it easier for the operator to observe the sawing situation.

[0030] 2. Due to the deflection angle range of the saw blade 12 [-3.5°, 3.5°], the skin remains elastic within this range, so the skin will not be damaged during the cutting of plaster.

[0031] 3. This plaster saw features a coaxial layout and can be designed in a slim, compact shape, further reducing overall weight. It is easy to grip, and its spherical and disc-like shapes are traditional and regular, making it easy to manufacture, simple to assemble, low-cost, and readily available for widespread adoption.

[0032] 4. The mechanical vibration of the structural transmission is small (the motor axis and the saw blade axis are arranged coaxially, and the active ball, passive ball and the groove surface of the disc are tangent and always maintain point contact), further realizing that the sawing noise at the highest speed is controllable to ≤75 decibels.

[0033] 5. Further reduce the external dimensions of the plaster saw (the motor axis and the saw blade axis are arranged coaxially, which is in contrast to the existing swing saws on the market where the motor and saw shaft are arranged in parallel intervals, resulting in a larger external dimension).

[0034] 6. It has 1-6 adjustable motor speeds, which can be adjusted by doctors (operators), which helps to reduce the noise of the plaster saw and improve the efficiency of sawing plaster. Attached Figure Description

[0035] Figure 1 This is a cross-sectional view of a medical plaster saw.

[0036] Figure 2 This is an outline drawing of a medical plaster saw.

[0037] Figure 3 A schematic diagram showing the installation of the active ball on the motor shaft;

[0038] Figure 4 This is a structural diagram of the motor shaft;

[0039] Figure 5 This is a structural diagram of the saw blade bearing seat;

[0040] Figure 6 This is a partial exploded view of a medical plaster saw.

[0041] Figure 7 This is a structural diagram of the annular groove;

[0042] Figure 8 This is a diagram showing the state of the system after the saw blade swings 3.5°.

[0043] Figure 9 This is a diagram showing the state of the system after the saw blade swings -3.5°.

[0044] Figure 10 This is a state diagram of the system when the saw blade is in its initial position.

[0045] Figure 11 A schematic diagram for obtaining the swing angle of the saw blade;

[0046] Figure 12 for Figure 1 A partial view.

[0047] Among them, 1-main body, 2-speed control knob, 3-power switch;

[0048] 4-Motor shaft, 5-Driving ball, 6-Disc, 7-Axial fixing plate, 8-Fixing pin, 9-Passive ball, 10-Saw blade shaft seat, 11-Saw blade shaft, 12-Saw blade, 13-Swing head assembly. Detailed Implementation

[0049] The medical plaster saw and its design method of this utility model will be described in more detail below with reference to the schematic diagrams, which illustrate preferred embodiments of this utility model. It should be understood that those skilled in the art can modify the utility model described herein while still achieving the advantageous effects of this utility model. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit this utility model.

[0050] A medical plaster saw comprises an eccentric ball mounted on a motor shaft driving a disc with an annular groove. Power is transmitted to another eccentric ball mounted on one side of the disc through a specific angle setting, thereby driving the saw blade mounting shaft to perform radial reciprocating sawing of plaster around the saw blade axis. This invention addresses the problem of existing plaster saws having a large structural size (including those using eccentric fork drives), particularly the large eccentricity between the saw blade mounting shaft and the handle, which leads to inconvenience and potential hazards from accidental sawing due to the need to change the grip direction when sawing plaster.

[0051] like Figures 1-12 Medical plaster saws include:

[0052] The swing head assembly 13, the positioning seat, and the main body 1 are connected sequentially along the Y direction by fasteners; the main body 1 is the grip handle.

[0053] The saw blade 12 is disposed on the saw blade shaft 11 and located outside the swing head assembly 13. The saw blade shaft 11 is rotatably mounted inside the swing head assembly 13. The section of the saw blade shaft 11 facing the main body 1, the saw blade shaft seat 10, and the driven ball 9 are connected in sequence. A preset distance is formed between the driven ball 9 and the axis of the saw blade shaft 11 in the X direction (i.e., the driven ball 9 is eccentrically set). The driven ball 9 contacts the two side walls of the annular groove opened on the disc 6 and forms a rotation gap with the inner wall of the swing head assembly 13.

[0054] The driven ball 9 is eccentrically positioned, forming a lever arm between itself and the axis of the saw blade shaft 11, and the disk 6 transmits torque to the saw blade shaft seat 10.

[0055] The disc 6 is used to drive the driven ball 9 to rotate around the axis of the saw blade shaft 11. It is sleeved on the fixing pin 8, which is set on the swing head assembly 13 and extends along the X direction. The disc 6 and the fixing pin 8 are clearance-fitted. The driven ball 9 will not generate a motion that rotates around its own axis.

[0056] The active ball 5 is eccentrically positioned at the end of the motor shaft 4 and contacts the two side walls of the annular groove on the disc 6; the motor shaft 4 is rotatably mounted on the positioning seat and extends along the Y direction into the main body 1; the motor corresponding to the motor shaft 4 is fixed inside the main body 1. The active ball 5 does not rotate around its own axis.

[0057] The axes of the main body 1, the motor shaft 4, the saw blade shaft seat 10, and the saw blade shaft 11 are all coaxial (coincident).

[0058] Furthermore, the end face of the motor shaft 4 where the drive ball 5 is mounted is an inclined end face. The inclined end face is arranged perpendicularly to the drive ball mounting hole, which facilitates the precise positioning of the tool used to machine the drive ball mounting hole and is also beneficial for axial limiting of the drive ball after interference fitting. The inclined surface and the drive ball limiting surface are parallel and coincident.

[0059] The inclined end face is arranged perpendicular to the active ball mounting hole, that is, the normal of the inclined end face is parallel to the axis of the active ball mounting hole.

[0060] Preferably, the spherical surfaces of the driving ball 5 and the driven ball 9 are both tangent to the two side walls of the annular groove. The diameters of the driving ball 5 and the driven ball 9 are equal.

[0061] The section of the saw blade shaft 11 facing the main body 1, the saw blade shaft seat 10, and the driven ball 9 are connected in sequence. The specific connection method involved is as follows:

[0062] The saw blade shaft 11 is fitted inside the saw blade shaft seat 10. The side of the saw blade shaft seat 10 facing the disc 6 is an inclined surface. A driven ball 9 is fixedly installed on the inclined surface, forming an angle with the axis of the saw blade shaft 11.

[0063] Regarding head oscillation component 13:

[0064] The head swing assembly 13 includes:

[0065] A first installation channel and a second installation channel extend along the Y direction and are connected; the first installation channel is used to install the saw blade shaft 11 and is open at one end facing the saw blade 12; the second installation channel is used to install the saw blade shaft seat 10, the driven ball 9 and the disc 6;

[0066] And a pin hole extending along the X direction for mounting the fixing pin 8, the pin hole connecting to the second mounting channel. Specifically, the fixing pin 8 and the pin hole are interference-fitted.

[0067] Regarding Installation Channel 1:

[0068] The No. 1 bearing cover, the No. 1 bearing, the transition cylinder, the No. 2 bearing, and the No. 2 bearing cover are installed sequentially in the No. 1 installation channel.

[0069] The No. 1 bearing cover is interference-fitted with the swing head assembly 13, and the No. 2 bearing cover is placed on the step, which is formed between the No. 1 installation channel and the No. 2 installation channel. One end of the saw blade shaft 11 is located outside the No. 1 bearing cover, and the other end passes through the No. 1 bearing, the transition cylinder, the No. 2 bearing, and the No. 2 bearing cover in sequence, and extends towards the No. 2 installation channel.

[0070] like Figure 1 As shown, the outer ring of bearing number one is secured in mounting channel number one, and the outer ring remains stationary.

[0071] The outer ring of bearing No. 2 is secured in mounting channel No. 1, and the outer ring remains stationary.

[0072] The transition tube is installed in the No. 1 installation channel.

[0073] Regarding installation channel number two:

[0074] An axial fixing piece 7 is installed between the second installation channel and the disc 6. A fixing pin 8 passes through the axial fixing piece 7, and both axial fixing pieces 7 are in contact with the disc 6. The side of the axial fixing piece 7 facing the disc 6 is flat to fit the disc 6.

[0075] "Adaptation" means that the axial fixing plate 7 and the fixing pin 8 remain stationary, and the disk 6 swings around the fixing pin 8, with the plane A on the disk 6 contacting the plane B on the axial fixing plate 7 and swinging on the surface of plane B.

[0076] Regarding the positioning seat:

[0077] A third mounting channel, corresponding to the second mounting channel, is provided inside the positioning seat for mounting the motor shaft 4.

[0078] A sealing ring is installed on the inner wall of installation channel number three, and bearing number three is installed inside the sealing ring. Bearing number three is placed on the shoulder of motor shaft 4. The outer ring of bearing number three remains stationary.

[0079] In addition, a power switch 3 and a speed control knob 2 are provided on the main body 1.

[0080] The power switch, power supply, and motor form a closed loop.

[0081] Adjusting the speed control knob 2 allows the motor to have 1-6 different speeds. Specifically, the speed control knob is thin and round, with numbers 1-6 engraved on the ring surface. The ring end face corresponding to the number has resistors and springs of different lengths, which are connected to a specific speed controller.

[0082] Because existing plaster saws lack adjustable cutting speed, they cannot accommodate saw blades of different diameters, resulting in inconsistent linear speeds of the rotating blades. This further impacts the efficiency of sawing plaster at the same rotation speed. Cutting linear speed—for example, saw blades with smaller diameters require higher rotation speeds to achieve higher linear speeds.

[0083] In this embodiment, the axis of the active ball 5 and the axis of the motor shaft 4 are at an angle of 3.5° to achieve an eccentric setting, and the active ball 5 and the motor shaft 4 are interference-fitted.

[0084] The center hole of the disc 6 is passed through by the cylindrical pin 8 and is fixed in the center hole of the oscillating head assembly 13 by two disc angular fixing pieces 7.

[0085] The driven ball 9 has the same diameter as the driving ball 5 and is fixed on the 45-degree inclined surface of the saw blade bearing 10.

[0086] The saw blade bearing seat 10 has a square through groove in the axial direction, which is coaxially and tightly fitted with the saw blade shaft 11.

[0087] The uppermost end face of the saw blade shaft 11 has a cross step for mounting a circular or fan-shaped saw blade 12. The saw blade 12 is fastened to the saw blade shaft 11 by an internal hex bolt and a pressure plate.

[0088] Pressing the power switch 3 powers on the motor located inside the main body 1. At this time, the motor shaft 1 drives the active ball 5 to rotate, causing the disc 6 to swing back and forth around the fixed pin 8 at ±3° (imagine the swinging of a rattle). The direction of rotation of the motor 1 remains unchanged. During one rotation of the motor, the disc 6 swings back and forth, and the saw blade 12 swings back and forth around the saw blade shaft 11.

[0089] Depend on Figures 8-9The direction in which disc 6 swings towards the paper is the positive direction. When disc 6 swings at 3.5°, saw blade 12 rotates counterclockwise.

[0090] As the disc 6 reciprocates, the power is transmitted through the annular groove of the disc 6 to the driven ball 9, which is tangent to the annular groove. The driven ball 9 reciprocates around the saw blade shaft 11 at a small angle, and simultaneously transmits the reciprocating motion through the saw blade shaft seat 10 and the saw blade shaft 11 to the saw blade 12 to perform high-frequency reciprocating motion around the saw blade axis, thereby realizing integrated power transmission and ultimately achieving the function of sawing plaster.

[0091] The principle by which the oscillation of disk 6 is converted into the rotational motion of driven ball 9 is as follows:

[0092] The driven ball 9 is connected to the saw blade bearing 10 as a whole. The saw blade bearing 10 only has rotational freedom about the Y direction (the direction of the axis of the saw blade shaft). Therefore, when the disk 6 acts on the driven ball 9, the saw blade bearing 10 can only rotate about the Y direction.

[0093] The speed control knob 2, located on the side of the main body 1, has 1-6 speed settings, allowing for speed adjustment from 8000 to 15000 rpm. This makes it easier for doctors to adjust the speed (cutting efficiency) during actual operation.

[0094] Figure 12 for Figure 1 The two images are enlarged views of a portion of the image, so there will be slight differences in the shape of some components, such as the active sphere 5 and the driven sphere 9.

[0095] like Figure 11 As shown, the angle between the driven ball 9 in the saw blade fixing seat 10 and the axis of the saw blade shaft 11 is a fixed 45-degree angle, and the deflection angle of the driving ball 5 fixed on the end face of the motor shaft 4 is 3.5 degrees.

[0096] The specific experimental steps are as follows:

[0097] Step 1: Design the swing angle, i.e. the deflection angle, of the saw blade 12.

[0098] Step 1A: Mark two points on an adult's skin and measure the distance L1 between the two points under normal conditions.

[0099] Then, pull the skin until pain is felt, and measure the distance L2 between the two points again.

[0100] The preliminary skin elasticity C1 is determined to be (L2 - L1).

[0101] Step 1B: Considering the skin elasticity of all population groups, multiply the skin elasticity obtained in Step 1A by a safety factor to obtain the final skin elasticity C2 = a * C1; 0 < a < 1

[0102] Step 1C: Calculate the central angle corresponding to the arc length C2 according to the formula for calculating the diameter and arc length of the saw blade 12. The central angle is the range of rotation angles of the saw blade 12.

[0103] The saw teeth within the central angle range are the saw teeth that participate in the cutting motion.

[0104] like Figure 10 The saw blade has 2.5 teeth involved in the sawing motion, and the rotation angle of the saw blade is ±3.5° to both sides of the vertical line from the center of the saw blade. That is, the rotation angle range of the saw blade 12 is 7°.

[0105] The skin elasticity of an adult is 15 mm, and the calculated final skin elasticity C2 is 4 mm.

[0106] Step 1D: The swing angle of saw blade 12 is ±3.5°.

[0107] Step 2: Based on the swing angle of the saw blade 12, calculate the angle between the driving ball 5 and the axis of the motor shaft 4, and the angle between the driven ball 9 and the axis of the saw blade shaft 11.

[0108] When the eccentricity angle of the active ball 5 is ±3.5°, the output inclined surface on the active ball is designed so that the composite motion of the active ball drives the swing angle of the swing plate to ±3.5°. When the swing plate swings, it drives the driven ball to move. Due to the axial positioning of the driven ball, the circumferential speed (i.e., the circumferential rotation of the swing saw) of the driven ball needs to be faster than the vertical speed (axial speed) so that the circumferential direction can drive the component 11 to rotate in time. Otherwise, it will be stuck and unable to rotate. That is, the vertical speed is less than the tangential speed, which satisfies the inclination angle of less than 45 degrees. If the angle is 0 degrees, it is coaxial with the axis and the speed is 0, so it cannot rotate. Therefore, 45 degrees is selected as the angle of the driven ball so that the rotation speed of the driven ball is consistent with the swing direction and speed of the swing plate. Therefore, the angle between the driven ball 9 and the saw blade axis is 45 degrees.

[0109] Furthermore, in the embodiments, extensive experiments have shown that the swing angle of the saw blade 12 can only be guaranteed to be ±3.5° when the angle between the driving ball 5 and the axis of the motor shaft 4 is ±3.5° and the angle between the driven ball 9 and the axis of the saw blade shaft is 45 degrees.

[0110] The above are merely preferred embodiments of this utility model and do not constitute any limitation on this utility model. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and contents disclosed in this utility model without departing from the scope of the technical solutions of this utility model shall still fall within the protection scope of this utility model.

Claims

1. A medical plaster saw, characterized in that, include: The swing head assembly (13), the positioning seat, and the main body (1) are connected sequentially along the Y direction; A saw blade (12) is disposed on the saw blade shaft (11) and located outside the swing head assembly (13). The saw blade shaft (11) is rotatably installed inside the swing head assembly (13). A section of the saw blade shaft (11) facing the main body (1), a saw blade shaft seat (10), and a driven ball (9) are connected in sequence. A preset distance is formed between the driven ball (9) and the axis of the saw blade shaft (11) along the X direction. The driven ball (9) contacts the two side walls of the annular groove opened on the disc (6) and forms a rotation gap with the inner wall of the swing head assembly (13). The disc (6) is used to drive the driven ball (9) to rotate around the axis of the saw blade shaft (11), and it is sleeved on the fixing pin (8). The fixing pin (8) is set on the swing head assembly (13) and extends along the X direction. The active ball (5) is eccentrically located at the end of the motor shaft (4) and contacts the two side walls of the annular groove on the disc (6); the motor shaft (4) is rotatably located on the positioning seat and extends along the Y direction into the main body (1); the motor corresponding to the motor shaft (4) is located in the main body (1); The axis of the motor shaft (4) is coaxial with the axis of the saw blade shaft (11).

2. The medical plaster saw according to claim 1, characterized in that The oscillating head assembly (13) includes: A first installation channel and a second installation channel extend along the Y direction and are connected; the first installation channel is used to install the saw blade shaft (11) and is open at one end facing the saw blade (12); the second installation channel is used to install the saw blade shaft seat (10), the driven ball (9) and the disc (6); and a pin hole extending along the X direction for mounting a fixing pin (8), wherein the fixing pin (8) is interference-fitted with the pin hole; the pin hole is connected to the second mounting channel.

3. The medical plaster saw according to claim 2, characterized in that The No. 1 installation channel is sequentially equipped with the No. 1 bearing cover, the No. 1 bearing, the transition cylinder, the No. 2 bearing, and the No. 2 bearing cover. The first bearing cover is interference-fitted with the swing head assembly (13), and the second bearing cover is placed on the step, which is formed between the first installation channel and the second installation channel; one end of the saw blade shaft (11) is located outside the first bearing cover, and the other end passes through the first bearing, the transition cylinder, the second bearing, and the second bearing cover in sequence, and extends toward the second installation channel.

4. The medical plaster saw according to claim 2, characterized in that The positioning seat has a third mounting channel that corresponds to the second mounting channel and is used to install the motor shaft (4); A sealing ring is installed on the inner wall of the No. 3 installation channel, and a No. 3 bearing is installed in the sealing ring. The No. 3 bearing is placed on the shoulder of the motor shaft (4).

5. The medical plaster saw according to claim 2, characterized in that An axial fixing piece (7) is inserted between the second installation channel and the disc (6). The fixing pin (8) passes through the axial fixing piece (7). Both axial fixing pieces (7) are in contact with the disc (6). The side of the axial fixing piece (7) facing the disc (6) is a plane to fit the disc (6).

6. The medical plaster saw according to claim 1, characterized in that The saw blade shaft (11) is fitted inside the saw blade shaft seat (10). The side of the saw blade shaft seat (10) facing the disc (6) is an inclined surface. A driven ball (9) is installed on the inclined surface, forming an angle with the axis of the saw blade shaft (11).

7. The medical plaster saw according to claim 1, characterized in that Both the active ball (5) and the driven ball (9) are tangent to the two side walls of the annular groove.

8. The medical plaster saw according to claim 1, characterized in that The motor shaft (4) is fixed to the inner wall of the main body (1).

Images