CN113952108B

CN113952108B - Eye phototherapy instrument

Info

Publication number: CN113952108B
Application number: CN202111468815.9A
Authority: CN
Inventors: 谢静; 胡永岚; 张国辉; 李栋栋
Original assignee: Guan Yeolight Technology Co Ltd
Current assignee: Guan Yeolight Technology Co Ltd
Priority date: 2021-12-03
Filing date: 2021-12-03
Publication date: 2023-07-11
Anticipated expiration: 2041-12-03
Also published as: CN113952108A

Abstract

The application provides an eye phototherapy instrument, include: a body; a groove body is arranged on one side of the body corresponding to eyes of a human body, and a treatment device is arranged in the groove body; the treatment device comprises: the device comprises a mounting sleeve and a light shield; the mounting sleeve is arranged in the groove body; an irradiation channel is formed between the inner side wall of the groove body and the outer side wall of the mounting sleeve; a plurality of light sources are arranged in the irradiation channel and used for emitting therapeutic light; the light shield is coaxially arranged in the mounting sleeve and used for shielding therapeutic light emitted into the eyeball. The application provides an eye phototherapy instrument can form annular treatment area, avoids treatment light to penetrate into the eyeball, plays the hot compress effect to this region simultaneously, further promotes the blood circulation of eye, alleviates black eye, improves the sour bloated of eye.

Description

Eye phototherapy instrument

Technical Field

The present disclosure relates generally to the field of phototherapy, and in particular, to an ocular phototherapy apparatus.

Background

The eye phototherapy instrument is mainly used for carrying out therapeutic light irradiation on eyes and can play a role in auxiliary treatment;

in the prior art, the treatment light emitted by the eye phototherapy instrument is dispersed, the treatment effect is poor, and the treatment light is easier to directly irradiate the eyelid or eyeball position, so that the eye discomfort is caused, and the eye health is also influenced.

Disclosure of Invention

In view of the above-described drawbacks or shortcomings of the prior art, it is desirable to provide an ocular phototherapy apparatus that can solve the above-described technical problems.

The application provides an eye phototherapy instrument, include: a body; a groove body is arranged on one side of the body corresponding to eyes of a human body, and a treatment device is arranged in the groove body;

the therapeutic device includes:

the mounting sleeve is arranged in the groove body; an irradiation channel is formed between the inner side wall of the groove body and the outer side wall of the mounting sleeve; a plurality of light sources are arranged in the irradiation channel and are used for emitting therapeutic light;

the light shield is coaxially arranged in the mounting sleeve and used for shielding therapeutic light emitted to the eyeball.

According to the technical scheme provided by the embodiment of the application, the side wall of the irradiation channel is provided with the reflecting structure.

According to the technical scheme provided by the embodiment of the application, the light shield is provided with a fixing part fixedly arranged in the mounting sleeve and a light shield part which is connected with the fixing part and extends out of the groove body; the shading part is of an elastic horn structure.

According to the technical scheme provided by the embodiment of the application, the eye shield is arranged in the shading part, and the heating plate for hot compress and/or the microwave generator for massage are arranged on the eye shield.

According to the technical scheme provided by the embodiment of the application, two groove bodies are arranged; the body is provided with a connecting part and two mounting parts arranged at one side of the connecting part; the two mounting parts are provided with deformation intervals, and the groove body is arranged on the mounting parts.

According to the technical scheme provided by the embodiment of the application, the position adjusting mechanism for adjusting the deformation interval is arranged between the two mounting parts.

According to the technical scheme provided by the embodiment of the application, the mounting sleeve is of an elastic structure and is provided with a first side wall close to the upper part of the eyes of a human body; a first adjusting component is arranged on the first side wall;

the first adjustment assembly includes:

a first platen mounted on the first sidewall;

one end of the first connecting rod is fixedly connected with the first pressing plate;

the first adjusting gear is rotatably arranged on the body and is fixedly connected with the other end of the first connecting rod;

the first connecting rod is arranged along the radial direction of the first adjusting gear, the axial direction of the first connecting rod forms an acute angle with the first direction, and the first direction is perpendicular to the first pressing plate.

According to the technical scheme provided by the embodiment of the application, a first through hole communicated with the inner wall of the groove body is formed in the side wall of the body, and the edge of the first adjusting gear extends out of the first through hole; the body is provided with a third side wall close to one side of the human canthus;

the first adjusting gear is provided with a plurality of first clamping teeth along the circumferential direction, a first clamping rod is hinged to the third side wall, a first spring is arranged between the first clamping rod and the third side wall, and the free end of the first clamping rod is in fit limit with the first clamping teeth.

According to the technical scheme provided by the embodiment of the application, the mounting sleeve is provided with a second side wall close to the lower part of the eyes of the human body, and a second adjusting component is mounted on the second side wall;

the adjustment assembly includes:

a second platen mounted on the second sidewall;

one end of the second connecting rod is fixedly connected with the second pressing plate;

the second adjusting gear is rotatably arranged on the body and is fixedly connected with the other end of the second connecting rod;

the second connecting rod is radially arranged along the second adjusting gear, and the axial direction of the second connecting rod is acute with the first direction.

According to the technical scheme provided by the embodiment of the application, the side wall of the body is provided with a second through hole communicated with the inner wall of the groove body, and the edge of the second adjusting gear extends out of the second through hole;

the second adjusting gear is provided with a plurality of second clamping teeth along the circumferential direction, a second clamping rod is hinged to the third side wall, a second spring is arranged between the second clamping rod and the third side wall, and the free end of the second clamping rod is in fit limit with the second clamping teeth.

The beneficial effects of this application lie in: when the eye mask is used, the eye mask covers the eyeball area of a human body, the light source is started, and treatment light emitted by the light source is emitted to the eyes of a patient through an irradiation channel formed by the inner wall of the groove body and the outer wall of the mounting sleeve at the moment to form an annular centralized treatment area; the annular treatment area acts on the periphery of the eyeball (namely the orbit position) of the human body to carry out phototherapy on the position; the light shield can further shield the therapeutic light injected into the eyeball, so that discomfort is avoided; the light source emits therapeutic light and simultaneously releases heat, so that the heat-treatment device can perform a hot compress function on the position, further promote the blood circulation of eyes, relieve dark circles and improve the acid swelling of the eyes.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the following drawings, in which:

fig. 1 is a schematic structural diagram of an ocular phototherapy apparatus provided in the present application;

fig. 2 is a schematic structural view of the mounting sleeve 3 shown in fig. 1, on which a first pressing plate 7 and a second pressing plate 16 are mounted;

FIG. 3 is a schematic view of the first clamping bar 14 shown in FIG. 2 with a first handle 26 mounted thereon;

fig. 4 is a schematic structural view of the second clamping bar 20 shown in fig. 2, on which a second handle 27 is mounted;

fig. 5 is a schematic top view of the eye phototherapy apparatus shown in fig. 1.

Reference numerals in the drawings:

1. a body; 2. a tank body; 3. a mounting sleeve; 4. an illumination channel; 5. a light source; 6. a light shield; 7. a first platen; 8. a first connecting rod; 9. a first adjusting gear; 10. a first through hole; 11. a connection part; 12. a mounting part; 13. a deformation interval; 14. a first clamping rod; 15. a first spring; 16. a second pressing plate; 17. a second connecting rod; 18. a second adjusting gear; 19. a second through hole; 20. a second clamping rod; 21. a second spring; 22. a first adjusting lever; 23. a second adjusting lever; 24. an adjusting nut; 25. an arc-shaped shielding member; 26. a first handle; 27. a second handle; 28. a headband; 29. a buckle;

Detailed Description

The present application is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be noted that, for convenience of description, only the portions related to the invention are shown in the drawings.

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Please refer to fig. 1, which is a schematic structural diagram of an eye phototherapy apparatus provided in the present application, a body 1; a groove body 2 is arranged on one side of the body 1 corresponding to eyes of a human body, and a treatment device is arranged in the groove body 2;

the therapeutic device includes:

the mounting sleeve 3 is arranged in the groove body 2; an irradiation channel 4 is formed between the inner side wall of the groove body 2 and the outer side wall of the mounting sleeve 3; a plurality of light sources 5 are arranged in the irradiation channel 4, and the light sources 5 are used for emitting therapeutic light;

and a light shield 6 coaxially arranged in the mounting sleeve 3 and used for shielding therapeutic light injected into the eyeball.

In this embodiment, the two grooves 2 are provided and are respectively arranged corresponding to the eyes of the human body, so that phototherapy can be performed on the eyes at the same time; in other embodiments, the trough body 2 may be provided with only one and corresponding to a single eye, so that phototherapy can be performed for a single eye, and the phototherapy process does not affect visual activity of a patient, for example, ocular phototherapy can be performed simultaneously during operation or leisure.

Specifically, the light source 5 is disposed in the illumination channel 4, and any one or more of the following manners may be adopted:

1. is fixedly arranged on the outer side wall of the mounting sleeve 3 along the circumferential direction;

2. fixedly arranged on the inner wall of the groove body 2 along the circumferential direction;

3. is filled between the mounting sleeve 3 and the tank body 2 by a filler (e.g. rubber, silica gel).

Specifically, the type of the light source 5 may be any one or more of the following:

1. the LED lamp beads are embedded into the mounting grooves, and the mounting grooves are formed in the outer side wall of the mounting sleeve 3 and/or the inner wall of the groove body 2; preferably, the mounting groove is a chute, so that the LED lamp beads are arranged towards eyes of a human body.

2. The LED lamp strips are arranged on the outer side wall of the mounting sleeve 3 and/or the inner wall of the groove body 2 in a sticking or embedding mode.

3. A flexible OLED panel; is mounted on the outer side of the mounting sleeve 3 and/or the inner wall of the groove body 2 in a sticking or embedding way.

Preferably, the mounting sleeve 3 is an annular sleeve, and the groove body 2 is a circular groove, so that an annular irradiation channel 4 can be formed between the mounting sleeve 3 and the groove body 2, and phototherapy can be conveniently carried out on the periphery of the eye.

Preferably, an elastic connecting sleeve is arranged between the light shield 6 and the mounting sleeve 3, so that the influence on the light shield and the treatment effect caused by position change of the light shield 6 in the use process is avoided.

Preferably, the side wall of the mounting sleeve 3 is provided with an arc shielding member 25 corresponding to the corner and/or tail of the eye, and the arc shielding member 25 is made of elastic materials, such as silica gel, rubber, etc. Light rays can be further prevented from entering the eyeball by providing the arc-shaped shielding member 25, and discomfort is avoided.

Working principle: when in use, the light shield 6 is covered on the eyeball area of a human body, the light source 5 is started, and the therapeutic light emitted by the light source 5 is emitted to the eyes of a patient through the irradiation channel 4 formed by the inner wall of the groove body 2 and the outer wall of the mounting sleeve 3 to form an annular centralized therapeutic area; the annular treatment area acts on the periphery of the eyeball (namely the orbit position) of the human body to carry out phototherapy on the position; the light shield 6 can further shield the therapeutic light injected into the eyeball, so as to avoid discomfort; the light source 5 emits therapeutic light and simultaneously releases heat, so that the hot compress effect can be realized on the position, the blood circulation of eyes is further promoted, dark circles are relieved, and the acid swelling of the eyes is improved.

In a preferred embodiment, the side walls of the illumination channel 4 are provided with reflective structures.

Specifically, the reflecting structure is a specular reflecting layer or a polyhedral reflecting layer;

by arranging the reflecting structure, more treatment light rays can be emitted from the irradiation channel 4, the treatment light rays are prevented from being blocked by the side wall of the mounting sleeve 3 or the groove body 2 in the use process, and the treatment effect is improved.

In a preferred embodiment, the light shielding cover 6 has a fixing portion fixedly installed in the installation sleeve 3 and a light shielding portion connected to the fixing portion and extending out of the groove body 2; the shading part is of an elastic horn structure.

Specifically, the elastic horn body structure is made of elastic materials such as rubber and silica gel, so that after the eye is worn, the eye can be closely contacted with the shading part, and the shading part can be matched with the periphery of the eyeball through the horn body structure, so that the shading effect is good.

In a preferred embodiment, an eye shield is arranged in the shading part, and a heating plate for hot compress and/or a microwave generator for massage are arranged on the eye shield. By arranging the heating plate and the microwave generator, the eyeballs and the peripheries of the eyeballs can be subjected to hot compress and massage in the phototherapy process.

Example 2

On the basis of embodiment 1, in this embodiment, the mounting sleeve 3 is of an elastic structure, and the mounting sleeve 3 has a first side wall close to the upper part of the eyes of the human body; a first adjusting component is arranged on the first side wall;

the first adjustment assembly includes:

a first platen 7 mounted on the first side wall;

one end of the first connecting rod 8 is fixedly connected with the first pressing plate 7;

the first adjusting gear 9 is rotatably arranged on the body 1 and is fixedly connected with the other end of the first connecting rod 8;

the first connecting rod 8 is radially arranged along the first adjusting gear 9, an axial direction of the first connecting rod 8 forms an acute angle with a first direction, and the first direction is perpendicular to the first pressing plate 7.

Working principle: as shown in fig. 2, when the first adjusting gear 9 is driven to rotate positively and negatively, the first pressing plate 7 can be driven to press down and lift up respectively, and the mounting sleeve 3 has an elastic structure, so that the mounting sleeve 3 can be deformed under stress, the position of the first side wall is adjusted, and the irradiation area of the irradiation channel 4 is adjusted.

In this embodiment, the light source 5 is preferably fixedly mounted on the outer wall of the mounting sleeve 3 in the circumferential direction. So that the position of the light source 5 follows the change in adjusting the shape of the mounting sleeve 3, which helps to get more therapeutic light into the focal area of the patient.

In a preferred embodiment, a first through hole 10 communicated with the inner wall of the tank body 2 is arranged on the side wall of the body, and the edge of the first adjusting gear 9 extends out of the first through hole 10; the body 1 is provided with a third side wall close to one side of the human canthus;

the first adjusting gear 9 is provided with a plurality of first clamping teeth along the circumferential direction, the third side wall is hinged with a first clamping rod 14, a first spring 15 is arranged between the first clamping rod 14 and the third side wall, and the free end of the first clamping rod 14 is in fit limit with the first clamping teeth.

Specifically, the first clamping rod 14 is disposed on the third side wall and is located below the first adjusting gear 9;

specifically, one end of the first spring 15 is fixedly connected with the third side wall, and the other end is fixedly connected with the side wall of the first clamping rod 14 far away from the free end.

Working principle: as shown in fig. 2 and fig. 3, when the first adjusting gear 9 is driven to lower the first pressing plate 7, the first clamping rod 14 may rotate in a direction away from the third side wall under the action of the first clamping teeth, so as to drive the first spring 15 to stretch; when the first clamping rod 14 rotates to be in contact with the next first clamping tooth, the first spring 15 is restored, and the free end of the first clamping rod 14 is in contact limit with the first clamping tooth;

the first clamping connection rod 14 cannot rotate along the direction close to the third side wall under the action of abutting with the first clamping teeth, so that the upward movement of the first pressing plate 7 is limited, and the limiting effect is achieved.

Preferably, the first clamping rod 14 is provided with a first handle 26, and the first clamping rod 14 is rotated in a direction away from the third side wall by pulling the first handle 26, so that the limit can be released from the first clamping teeth.

In a preferred embodiment, the mounting sleeve 3 has a second side wall adjacent to the underside of the human eye, on which a second adjustment assembly is mounted;

the adjustment assembly includes:

a second platen 16 mounted on the second side wall;

a second connecting rod 17, one end of which is fixedly connected with the second pressing plate 16;

the second adjusting gear 18 is rotatably arranged on the body 1 and is fixedly connected with the other end of the second connecting rod 17;

the second connecting rod 17 is radially arranged along the second adjusting gear 18, and the axial direction of the second connecting rod 17 forms an acute angle with the first direction.

Working principle: as shown in fig. 2, when the second adjusting gear 18 is driven to rotate forward and backward, the second pressing plate 16 is driven to press down and lift up respectively, and the mounting sleeve 3 has an elastic structure, so that the mounting sleeve 3 can be deformed under force to adjust the position of the second side wall, thereby adjusting the irradiation area of the irradiation channel 4.

In a preferred embodiment, a second through hole 19 communicated with the inner wall of the tank body 2 is arranged on the side wall of the body 1, and the edge of the second adjusting gear 18 extends out of the second through hole 19;

the second adjusting gear 18 is provided with a plurality of second clamping teeth along the circumferential direction, the third side wall is hinged with a second clamping rod 20, a second spring 21 is arranged between the second clamping rod 20 and the third side wall, and the free end of the second clamping rod 20 is in fit limit with the second clamping teeth.

Specifically, the second clamping rod 20 is disposed on the third side wall and above the second adjusting gear 18;

specifically, one end of the second spring 21 is fixedly connected to the third side wall, and the other end is fixedly connected to the side wall of the second clamping rod 20 away from the free end.

Working principle: as shown in fig. 2 and fig. 4, when the second adjusting gear 18 is driven to raise the second pressing plate 16, the second clamping rod 20 can rotate along the direction away from the third sidewall under the action of the second clamping teeth, so as to drive the second spring 21 to stretch; when the second clamping rod 20 rotates to be in contact with the next second clamping tooth, the second spring 21 is restored, and the free end of the second clamping rod 20 is in contact with the second clamping tooth to limit;

the second clamping rod 20 cannot rotate along the direction close to the third side wall under the action of abutting with the second clamping teeth, so that the downward movement of the second pressing plate 16 is limited, and the limiting effect is achieved.

Preferably, the second clamping rod 20 is provided with a second handle 27, and the second clamping rod 20 is rotated in a direction away from the third side wall by pulling the first handle 27, so that the limit can be released from the second clamping teeth.

In this embodiment, the first adjusting component is disposed on the first side wall, and the second adjusting component is disposed on the second side wall, so that the shape of the mounting sleeve 3 can be adjusted by rotating the first adjusting gear 9 and the second adjusting gear 18, so as to adjust the irradiation area of the irradiation channel 4. Namely:

when the distance between the focus area of the patient and the edge of the eyeball is smaller, the adjusting gear can be driven to drive the pressing plate connected with the adjusting gear to compress the mounting sleeve 3 until the focus area can be irradiated by the light source.

When the distance between the focus area of the patient and the edge of the eyeball is larger, the adjusting gear can be reversely driven to drive the pressing plate connected with the adjusting gear, so that the deformation of the mounting sleeve 3 is recovered.

Meanwhile, the first clamping connection rod 14 and the second clamping connection rod 20 are arranged, so that the adjusting gear adjusted to the adapting position can be limited.

Example 3

In this embodiment, as shown in fig. 5, on the basis of embodiment 1, two grooves 2 are provided; the body 1 has a connecting portion 11 and two mounting portions 12 provided on one side of the connecting portion 11; a deformation space 13 is arranged between the two mounting parts 12, and the groove body 2 is arranged on the mounting parts 12.

Specifically, since the deformation interval 13 is provided between the two mounting portions 12, the deformation interval 13 of the two mounting portions 12 can be adjusted according to the distance between the eyes of different patients. The problem that the therapeutic light source cannot be accurately injected into the focus area due to the difference of the interocular distances of different patients is avoided, and the therapeutic effect is improved.

In a preferred embodiment, a position adjusting mechanism for adjusting the deformation interval is installed between the two mounting portions 12.

The position adjustment structure includes: the first adjusting rods 22 and the second adjusting rods 23 are respectively arranged on the two mounting parts 12, the first adjusting rods 22 and the second adjusting rods 23 are oppositely arranged, adjusting nuts 24 are movably connected to the first adjusting rods 22, and external threads for being in threaded connection with the adjusting nuts 24 are arranged at the end parts of the second adjusting rods 23.

Preferably, the body is of a U-shaped structure;

preferably, the headband 28 is installed on two sides of the body, and the adjusting buckle 29 is installed on the headband 28.

Preferably, a power supply for supplying power to the light source and/or the heating sheet and/or the microwave generator is installed in the connection part 11.

The foregoing description is only of the preferred embodiments of the present application and is presented as a description of the principles of the technology being utilized. It will be appreciated by persons skilled in the art that the scope of the invention referred to in this application is not limited to the specific combinations of features described above, but it is intended to cover other embodiments in which any combination of features described above or equivalents thereof is possible without departing from the spirit of the invention. Such as the above-described features and technical features having similar functions (but not limited to) disclosed in the present application are replaced with each other.

Claims

1. An ocular phototherapy apparatus, comprising: a body (1); a groove body (2) is arranged at one side of the body (1) corresponding to eyes of a human body, and a treatment device is arranged in the groove body (2);

the therapeutic device includes:

the mounting sleeve (3) is arranged in the groove body (2); an irradiation channel (4) is formed between the inner side wall of the groove body (2) and the outer side wall of the mounting sleeve (3); a plurality of light sources (5) are arranged in the irradiation channel (4), and the light sources (5) are used for emitting therapeutic light;

the light shield (6) is coaxially arranged in the mounting sleeve (3) and is used for shielding therapeutic light injected into the eyeball;

the mounting sleeve (3) is of an elastic structure, and the mounting sleeve (3) is provided with a first side wall close to the upper part of the eyes of a human body; a first adjusting component is arranged on the first side wall;

the first adjustment assembly includes:

a first platen (7) mounted on the first side wall;

one end of the first connecting rod (8) is fixedly connected with the first pressing plate (7);

the first adjusting gear (9) is rotatably arranged on the body (1) and is fixedly connected with the other end of the first connecting rod (8);

the first connecting rod (8) is radially arranged along the first adjusting gear (9), and the first pressing plate (7) can be driven to compress the mounting sleeve (3) by rotating the first adjusting gear (9).

2. The ocular phototherapy apparatus according to claim 1, characterized in that the side wall of the illumination channel (4) is provided with a reflective structure.

3. The ocular phototherapy apparatus according to claim 1, characterized in that the light shield (6) has a fixing portion fixedly mounted in the mounting sleeve (3) and a light shielding portion connected to the fixing portion and extending out of the groove body (2); the shading part is of an elastic horn structure.

4. The ocular phototherapy apparatus as defined in claim 3, wherein an eye shield is provided in the light shielding portion, and a heating sheet for hot compress and/or a microwave generator for massage are mounted on the eye shield.

5. The ocular phototherapy apparatus according to claim 1, characterized in that the trough body (2) is provided with two; the body (1) is provided with a connecting part (11) and two mounting parts (12) arranged on one side of the connecting part (11); a deformation interval (13) is arranged between the two mounting parts (12), and the groove body (2) is arranged on the mounting parts (12).

6. The ocular phototherapy apparatus according to claim 5, characterized in that a position adjusting mechanism for adjusting the deformation interval is installed between the two mounting portions (12).

7. The eye phototherapy apparatus according to claim 1, characterized in that a first through hole (10) communicating with the inner wall of the groove body (2) is provided on the side wall of the body, and the edge of the first adjusting gear (9) extends out of the first through hole (10); the body (1) is provided with a third side wall close to one side of the human canthus;

the first adjusting gear (9) is provided with a plurality of first clamping teeth along the circumferential direction, a first clamping rod (14) is hinged to the third side wall, a first spring (15) is arranged between the first clamping rod (14) and the third side wall, and the free end of the first clamping rod (14) is in limit fit with the first clamping teeth.

8. The ocular phototherapy apparatus according to claim 7, characterized in that the mounting sleeve (3) has a second side wall close to the underside of the human eye, on which second side wall a second adjustment assembly is mounted;

the adjustment assembly includes:

a second platen (16) mounted on the second sidewall;

one end of the second connecting rod (17) is fixedly connected with the second pressing plate (16);

the second adjusting gear (18) is rotatably arranged on the body (1) and is fixedly connected with the other end of the second connecting rod (17);

wherein the second connecting rod (17) is radially arranged along the second adjusting gear (18); when the second adjusting gear (18) is driven to rotate positively and negatively, the second pressing plate (16) can be driven to press downwards and ascend respectively, so that the mounting sleeve (3) can deform under stress, the position of the second side wall is adjusted, and the irradiation area of the irradiation channel (4) is adjusted.

9. The eye phototherapy apparatus according to claim 8, characterized in that a second through hole (19) communicating with the inner wall of the groove body (2) is provided on the side wall of the body (1), and the edge of the second adjusting gear (18) extends out of the second through hole (19);

the second adjusting gear (18) is provided with a plurality of second clamping teeth along the circumferential direction, the third side wall is hinged with a second clamping rod (20), a second spring (21) is arranged between the second clamping rod (20) and the third side wall, and the free end of the second clamping rod (20) is in limit fit with the second clamping teeth.