CN114052847B

CN114052847B - Endoscopic surgical instrument and protection device therefor

Info

Publication number: CN114052847B
Application number: CN202010747318.1A
Authority: CN
Inventors: 唐志; 张岚; 董文君
Original assignee: Micro Tech Nanjing Co Ltd
Current assignee: Micro Tech Nanjing Co Ltd
Priority date: 2020-07-29
Filing date: 2020-07-29
Publication date: 2024-02-02
Anticipated expiration: 2040-07-29
Also published as: CN114052847A

Abstract

The application discloses an endoscopic surgical instrument comprising: the endoscope surgical instrument comprises an outer tube, a needle, an actuating member and an outer tube, wherein the needle can extend out of the outer tube and retract into the outer tube under the actuating action of the actuating member, the endoscope surgical instrument further comprises a protection device for preventing the outer tube from being stabbed by the needle when the outer tube is bent, and the protection device comprises a protection ring arranged on the inner wall of the outer tube, and the protection ring at least surrounds the needle tip of the needle when the needle retracts into the outer tube. The application also discloses a corresponding protection device. According to the present invention, it is possible to help prevent the outer tube from being scratched by the needle when bending by providing a protective ring that can be disposed within the outer tube of an endoscopic surgical instrument to surround the needle tip.

Description

Endoscopic surgical instrument and protection device therefor

Technical Field

The present invention relates to medical instruments for endoscopic diagnosis and treatment, and more particularly, to an endoscopic surgical instrument with a needle and a protector for the same.

Background

Currently, there are few endoscopic surgical instruments with a needle (e.g., a puncture needle) on the market, near the needle, with a structural design for protecting the needle tip and/or an outer tube that is sleeved outside the needle, so that the needle tip can stab the outer tube when passing through a larger curve, resulting in curling and dullness of the needle tip, blocking puncture and even failing to go out of the needle, and possibly stabbing the outer tube and even scratching the endoscope.

Thus, there is a need to develop a new type of endoscopic surgical instrument with a needle in which a needle/outer tube protection device is provided so that the needle tip and/or outer tube can be effectively protected while the needle passes through a curve and can easily pass through the curve.

Disclosure of Invention

It is an object of the present invention to provide an endoscopic surgical instrument and a protection device therefor which at least partly solves the problem of protecting the needle tip and/or the outer tube from damage when the needle passes through a curve.

According to one aspect of the present invention there is provided an endoscopic surgical instrument comprising: the endoscope surgical instrument comprises a needle, an actuating element connected to the tail of the needle, and an outer tube sleeved outside the needle and the actuating element, wherein the needle can extend out of the outer tube and retract into the outer tube under the actuating action of the actuating element, the endoscope surgical instrument further comprises a protection device for preventing the outer tube from being stabbed by the needle when the outer tube is bent, and the protection device comprises a protection ring arranged on the inner wall of the outer tube, and the protection ring at least surrounds the needle tip of the needle when the needle is retracted into the outer tube.

In some advantageous embodiments, the guard ring is made of a material having a hardness greater than that of the outer tube, preferably the guard ring is made of a metallic material.

In some embodiments, the actuating member may be an inner tube extending through the outer tube, the needle may be a needle and coupled to the tip of the inner tube, and the endoscopic surgical instrument may further include a handle assembly coupled to the outer tube and the inner tube, respectively, for manipulating the inner tube in and out of motion relative to the outer tube.

According to another aspect of the present invention, there is provided a protective device for an endoscopic surgical instrument as described above, the protective device comprising a protective ring, a ring wall of the protective ring being formed with a discontinuous or thinned structure of material in a direction of an axial direction of the protective ring.

In some advantageous embodiments, the protective ring has a plurality of grooves formed in its annular wall, the plurality of grooves extending at least in the circumferential direction of the protective ring and being staggered such that adjacent grooves in the axial direction of the protective ring are offset from each other in the circumferential direction of the protective ring.

Advantageously, the direction of extension of the plurality of slots may be parallel to the circumference of the protection ring.

Preferably, the plurality of slits have a width of 0.05mm or less, and the axial direction-adjacent slits have a pitch of 0.2mm or less in the axial direction.

Further, it is preferable that the plurality of slits have the same length, and the length is equal to or greater than a quarter of the circumference of the protection ring.

In further advantageous embodiments, at least one groove is formed on the outer surface of the ring wall of the protection ring, at which groove the ring wall thickness of the protection ring is reduced, the at least one groove extending at least in the circumferential direction of the protection ring, and the ring wall of the protection ring has a continuous, smooth inner surface.

In other advantageous embodiments, a plurality of scale structures are formed on the annular wall of the protection ring, each scale structure is formed by deflecting a part of material of the annular wall of the protection ring towards the axis along the needle point direction of the needle head, and the plurality of scale structures are staggered.

Preferably, the spacing between the axially adjacent scale structures in the axial direction is equal to or less than twice the height of the scale, and the distance that the tail ends of the scale structures deviate from the annular wall to the axis is greater than the thickness of the annular wall.

Preferably, the scale structure has rounded ends, and a width of a root portion of the scale structure connected to the annular wall of the protection ring is greater than a distance in the circumferential direction of the circumferentially adjacent scale structure.

In some advantageous embodiments, the protection device may further comprise an end tube, and one end of the protection ring is connected to the end tube.

Preferably, the outer surface of the end tube has a barb or threaded projection structure formed thereon for securing the end tube to the inner wall of the member receiving the end tube.

The guard ring and the end tube may be joined together by welding or riveting.

Advantageously, one end of the end tube may be formed with a flange for limiting. The flange is adapted to bear against an end face of a distal end of an outer tube of an endoscopic surgical instrument.

Preferably, the guard ring is made of a metallic material.

According to yet another aspect of the present invention, there is provided a protective device for an endoscopic surgical instrument as described above, comprising a protective ring, the ring wall of the protective ring being wavy in shape along the axial direction of the protective ring and having a smooth inner surface.

According to embodiments of the present invention, by providing a protective ring that may be disposed within an outer tube of an endoscopic surgical instrument to surround a needle tip, it may be helpful to prevent the outer tube from being lacerated by the needle when bent.

Drawings

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

FIG. 1 is a schematic view of a protective device and endoscopic surgical instrument according to a first embodiment of the present invention;

FIG. 2 is an enlarged view of a portion of an endoscopic surgical instrument according to a first embodiment of the present invention;

FIG. 3 is a perspective view of one example of a protective ring according to a first embodiment of the present invention employed in the endoscopic surgical instrument shown in FIG. 2, wherein a notch is formed in the protective ring;

FIG. 4 is an enlarged view of a portion of the guard ring of FIG. 3;

fig. 5 is a modified example of the guard ring shown in fig. 3 and 4;

FIG. 6 is a schematic cross-sectional view of one example of a protective ring according to a second embodiment of the present invention applicable to endoscopic surgical instruments, wherein a groove is formed in the protective ring;

FIG. 7 is a perspective view of one example of a protective ring according to a third embodiment of the present invention applicable to an endoscopic surgical instrument, wherein the protective ring has a scale structure formed thereon;

FIG. 8 is a view of the protective ring of FIG. 7 taken in the direction indicated by the arrow in FIG. 7;

FIG. 9 schematically illustrates a state of the guard ring of FIG. 7 during formation, wherein the scale structure has not been deflected toward the center of the guard ring;

FIGS. 10 and 11 schematically illustrate the relative partial dimensions of the scale structure on the guard ring of FIG. 7;

FIG. 12 is a schematic view of one example of a protective ring according to a fourth embodiment of the present invention applicable to endoscopic surgical instruments, wherein the protective ring has an axially wave-shaped ring wall;

FIG. 13 is an enlarged view of a portion of an endoscopic surgical instrument according to a second embodiment of the present invention; and

FIG. 14 is a schematic view of a protective device employed in the endoscopic surgical instrument shown in FIG. 13, wherein the protective device includes a protective ring and an end tube.

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.

In the present invention, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate an azimuth or a positional relationship based on that shown in the drawings. These terms are only used to better describe the present invention and its embodiments and are not intended to limit the scope of the indicated devices, elements or components to the particular orientations or to configure and operate in the particular orientations.

Fig. 1 is a schematic structural view of an endoscopic surgical instrument 10 and a protection device provided therein according to a first embodiment of the present invention.

As shown in fig. 1, the endoscopic surgical instrument 10 includes a needle 11, an actuator 12 connected to the tail of the needle 11, and an outer tube 13 sleeved outside the needle 11 and the actuator 12. The needle 11 is connected to the tip of the actuator 12 and is adapted to extend from the distal end 13a of the outer tube 13 out of the outer tube 13 and back into the outer tube 13 under the actuation of the actuator 12. Fig. 1 shows the state in which the needle 11 is retracted inside the outer tube 13.

The needle 11 may be, for example, a puncture needle, but is not limited thereto. In the example shown in fig. 1, the actuator 12 is an inner tube which extends through the outer tube 13 and is axially movable relative to the outer tube 13. In other examples, actuator 12 may also be, for example, a pushrod, although the invention is not limited in this respect. As shown in FIG. 1, endoscopic surgical instrument 10 may further include a handle assembly 14 at a proximal end 13b of outer tube 13 distal from needle 11, handle assembly 14 being coupled to outer tube 13 and inner tube 12, respectively, and operable to manipulate the advancement and retraction of inner tube 12 relative to outer tube 13.

In use, endoscopic surgical instrument 10 is advanced with needle 11, inner tube 12 and outer tube 13 into the body of the subject being treated. During the pushing process, the needle 11 is kept retracted inside the outer tube 13; when the distal end of the outer tube 13 is in a bent state, the needle 11 is in a curve formed by the outer tube 13, which often punctures the inner wall of the outer tube 13, and may cause damage to the needle. The inventors of the present invention have noted this problem and have proposed that a protective device 100 for preventing the outer tube 13 from being stabbed by the needle 11 when bending is further provided in the endoscopic surgical instrument 10 according to an embodiment of the present invention.

According to the first embodiment of the present invention, the protection device 100 includes a protection ring 100a provided on the inner wall of the outer tube 13. When the needle 11 is retracted into the outer tube 13, the guard ring 100a surrounds at least the tip 11a of the needle 11 (see fig. 1).

In some implementations, the guard ring 100a may be formed as a separate annular member and fixedly or movably positioned inside the distal end 13a of the outer tube 13. For example, the guard ring 100a may be bonded to the inner wall of the outer tube 13. In other implementations, the guard ring 100a may also be formed as a portion of the inner wall of the outer tube 13, for example, by physically/chemically treating the inner wall of the distal end portion of the outer tube (the portion of the inner wall surrounding the needle tip portion of the needle) so that the portion of the inner wall has a greater hardness than the other portions of the inner wall, thereby preventing the outer tube from being damaged by the needle tip. The invention is not limited to the use of a particular form of guard ring.

The guard ring 100a has a hardness greater than that of the outer tube 13. For example, the guard ring 100a may be made of a material having a hardness greater than that of the outer tube 13. Preferably, the guard ring 100a is made of a metallic material, such as stainless steel, nitinol, or the like.

In some advantageous embodiments, the annular wall of the guard ring 100a is formed with a discontinuous or thinned structure of material in the direction of the guard ring axis. This will be described below in connection with fig. 2 to 11.

Fig. 2 is a partial enlarged view of the endoscopic surgical instrument 10 according to the first embodiment of the present invention, and fig. 3 shows a perspective view of one example of a protection ring (protection ring 110) according to the first embodiment of the present invention employed in the endoscopic surgical instrument 10 shown in fig. 2. As more clearly shown in fig. 3, a plurality of slits 112 are formed in the annular wall 111 of the protection ring 110, so that the material of the annular wall 111 of the protection ring 110 is discontinuous in the axial direction of the protection ring. The plurality of slits 112 extend in the circumferential direction of the protection ring 110 (in the direction indicated by the arrow in fig. 3), and are staggered such that the slits (for example, slits 112a, 112b shown in fig. 3) adjacent in the axial direction of the protection ring 110 are offset from each other in the circumferential direction of the protection ring 110. The guard ring 110 is preferably made of metal. The staggered arrangement of the slots 112 allows the guard ring 110 to flex more easily and with a degree of resiliency, thereby facilitating the smooth passage of the guard needle 11 and outer tube 13 through various bends in the body of the subject being treated.

In the example shown in fig. 3, a plurality of slits 112 may be formed on one circumferential turn of the annular wall 111 of the protection ring 110; however, the present invention is not limited thereto, and fewer slits, such as one or two slits, may be formed on one circumferential turn of the annular wall, for example.

Fig. 4 is an enlarged view of a portion of the guard ring 110 shown in fig. 3; as shown in fig. 4, the slit 112 has a very long and narrow shape. Preferably, the width w of the slit 112 is less than or equal to 0.05mm, more preferably the width w is less than or equal to 0.03mm, which allows the inner wall of the guard ring 110 to still correspond to a smooth surface with respect to the size of the needle tip 11a of the needle 11. In this way, the needle tip 11a contacts the guard ring 110 during the curve, and slides on the smooth and hard inner wall of the guard ring 110, so that the needle tip 11a is not damaged, nor the outer tube 13 is stabbed.

Preferably, the axially adjacent slots 112 are spaced apart by 0.2mm or less in the axial direction, so that the slots 112 are more closely spaced in the axial direction. This is advantageous in that, on the one hand, the flexibility of the guard ring 110 is increased to be more easily bent with the outer tube 13, and on the other hand, the increase in the width w of each of the slits 112 of the guard ring 110 on the outer side (the side away from the center of bending) when bent is suppressed. Suppressing the increase in the width w of the slit 112 is advantageous in maintaining the smoothness of the inner wall of the guard ring 110 with respect to the needle tip 11a, thereby preventing the needle tip 11a from being damaged.

In addition, as shown in fig. 3 and 4, the plurality of slits 112 may be configured to have the same length l, which is advantageous in achieving the same mechanical strength and elasticity of the protection ring 110 in various directions of the annular wall 111, and the like, and also has advantages in terms of design and manufacturing. The length l of the plurality of slots 112 is preferably equal to or greater than one-fourth the circumference of the guard ring 110.

In the examples shown in fig. 2-4, the plurality of slots of the protective ring extend along the circumference of the protective ring; however, the present invention is not limited thereto. Fig. 5 shows a modification of the guard ring 110 shown in fig. 3 and 4, the guard ring 110'. As shown in fig. 5, the plurality of slits 112 'of the guard ring 110' extend not only in the circumferential direction but also in the axial direction; in other words, the extending direction of the plurality of slits 112' is inclined with respect to the circumferential direction of the protection ring. Preferably, as shown in fig. 5, the direction in which the notch 112 'extends forms an acute angle θ of 30 ° or less with respect to the circumferential direction of the protection ring 110'.

Fig. 6 schematically illustrates one example of a protective ring (protective ring 120) according to a second embodiment of the present invention that may be applied to an endoscopic surgical instrument 10. As shown, at least one groove 122 is formed on the outer surface of the annular wall 121 of the protection ring 120, and the groove 122 extends at least in the circumferential direction of the protection ring 120. The thickness of the annular wall 121 of the guard ring 120 is reduced at the recess 122. The groove 122 may be, for example, a continuous spiral groove, or may be, for example, a plurality of grooves having an arrangement as shown in fig. 4 or 5. With respect to the slots 112, 112', the grooves 122 are formed only on the outer surface of the protective annular wall and do not extend through to the inner surface of the annular wall. In this way, the guard ring 120 with the groove 122 can have a continuously smooth inner surface.

Since the outer surface of the guard ring 120 is formed with the groove 122 of the thinned wall material and the groove extends at least in the circumferential direction, the guard ring 120 can have improved bending deformation capability while the guard ring 120 can maintain a continuous, smooth inner surface, which is advantageous in preventing damage to the needle tip and the outer tube.

An example of a protective ring (protective ring 130) according to a third embodiment of the present invention that can be applied to an endoscopic surgical instrument 10 will be described next with reference to fig. 7 to 11.

Fig. 7 is a schematic perspective view of the guard ring 130, and fig. 8 is a view of the guard ring 130 taken in the direction indicated by the arrow in fig. 7.

As shown in fig. 7 and 8, a plurality of scale structures 132 are formed on the annular wall 131 of the guard ring 130, each of the scale structures 132 is formed by a portion of the material of the annular wall 131 being deflected toward the axial center in the direction of the needle tip 11a of the needle 11, and the plurality of scale structures 132 are staggered.

The guard ring 130 may be manufactured by, for example, engraving a groove (as shown in fig. 9) corresponding to the outline of the scale structure 132 in the annular wall 131 of the guard ring 130 using a laser engraving technique, and then pressing the scale inward to deflect it to a predetermined degree using a special tool.

As shown in fig. 10, the scale structure 132 preferably has rounded ends, and the width D of the root portion of the scale structure 132 connected to the annular wall 131 is greater than the distance D of the circumferentially adjacent scale structure 132 in the circumferential direction.

Further, as shown in fig. 10, the scale structure 132 has a height H in the axial direction, and the axially adjacent scale structures 132a, 132b of the guard ring 130 have a spacing H in the axial direction, preferably H is equal to or less than twice the scale height H.

Further, as shown in fig. 11, the distance B by which the end of the scale structure 132 is deviated from the annular wall 131 toward the axial center is preferably larger than the thickness B of the annular wall 131. However, this is not necessary as long as the distance B by which the tip of the scale structure 132 is deflected toward the axial center by the annular wall 131 ensures that when the protection ring 130 is bent with the outer tube 13, the deflected scale structure 132 can shield the opening area on the annular wall 131, thereby preventing the needle tip 11a from passing through or being caught in the opening area.

According to the third embodiment of the present invention, although the inner wall of the guard ring 130 is not a smooth surface, since the scale on the guard ring wall located on the outer side shields the opening area and does not form a barrier to the needle tip 11a in the direction along the needle tip 11a when such guard ring 130 is bent, the guard ring 130 can prevent the needle tip or the outer tube 13 from being damaged when the outer tube 13 is bent.

Meanwhile, since a part of the material of the annular wall 131 is cut and deflected toward the axial center, in other words, the annular wall 131 forms a discontinuous structure of the material in the axial direction, the protective ring 131 has a better bending deformation capability, and thus can be bent more flexibly with the outer tube 13.

Various embodiments of a discontinuous or thinned structure of material formed axially of the guard ring wall are described above in connection with fig. 2-11. However, it should be understood that the guard ring according to embodiments of the present invention is not limited to a discontinuous structure or a thinned structure having the above-described materials. For example, a protective ring 140 according to a fourth embodiment of the present invention, as shown in fig. 12, has a continuous annular wall 141 of material, the annular wall 141 being in a wavy shape in the axial direction. Such a guard ring 140 may also be referred to as a "bellows-type" guard ring. When the bellows-type protector ring 140 is bent with the outer tube, the wavy shape of the outer-located ring wall 141 is unfolded so that a smooth inner surface along which the needle tip 11a is guided to slide can be formed, thereby preventing the needle tip or the outer tube from being damaged.

An endoscopic surgical instrument 10' and a protective device 200 according to a second embodiment of the present invention are described below in connection with fig. 13 and 14.

The endoscopic surgical instrument 10' according to the second embodiment of the present invention has substantially the same structure as the endoscopic surgical instrument 10 according to the first embodiment of the present invention, except that: as shown in fig. 13 and 14, in the endoscopic surgical instrument 10', the protective device 200 includes an end tube 200b in addition to the protective ring 200 a; one end of the protective ring 200a is connected to the end tube 200b, and the end tube 200b is adapted to be fixedly connected to a distal end 13a of the outer tube 13 of the endoscopic surgical instrument 10' adjacent to the needle 11 a.

The protection ring 200a according to the second embodiment of the present invention may be the same protection ring as the protection ring 100a of the protection device 100 according to the first embodiment of the present invention, and will not be described again.

The protective ring 200a and the end tube 200b may be integrally formed or may be separately formed and then fixedly connected together, for example, by welding or riveting. Of course, the invention is not limited in the particular manner in which the protection ring and end tube are connected. For example, the two may be fixed together by bonding or interference fit.

Referring to FIG. 14, in an advantageous embodiment, a barbed or threaded raised structure 200b-1 may be formed on the outer surface of the end tube 200b for securing the end tube 200b to the inner wall of the outer tube 13 of the endoscopic surgical instrument 10'.

Further, as shown in fig. 13 and 14, one end of the end pipe 200b may be formed with a flange 200b-2 for limiting. Flange 200b-2 is adapted to abut against the end face of distal end 13a of outer tube 13 when protective device 200 is assembled to endoscopic surgical instrument 10'. Such a configuration facilitates axial positioning of the protective device 200 on the outer tube 13.

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 endoscopic surgical instrument, comprising: a needle, an actuating member connected to the tail of the needle, and an outer tube sleeved outside the needle and the actuating member, the needle being capable of extending out of the outer tube and retracting into the outer tube under the actuation of the actuating member, wherein the endoscopic surgical instrument further comprises a protection device for preventing the outer tube from being scratched by the needle when the outer tube is bent, the protection device comprising a protection ring provided on an inner wall of the outer tube, the protection ring surrounding at least the tip of the needle when the needle is retracted into the outer tube, and

the annular wall of the protection ring is formed with a discontinuous structure or a thinned structure of material in the axial direction of the protection ring, wherein:

the discontinuity includes a plurality of slits having an elongated shape and having a width configured such that the annular wall of the protective ring has a smooth inner surface relative to the needle tip;

the thinning structure includes at least one groove formed on an outer surface of a wall of the guard ring such that the wall of the guard ring has a smooth inner surface relative to the needle tip.

2. The endoscopic surgical instrument of claim 1, wherein the guard ring is made of a material having a hardness greater than the outer tube.

3. The endoscopic surgical instrument of claim 1, wherein the guard ring is made of a metallic material.

4. The endoscopic surgical instrument of claim 1, wherein the plurality of slots extend at least in a circumferential direction of the protective ring and are staggered such that axially adjacent slots of the protective ring are circumferentially offset from one another.

5. The endoscopic surgical instrument according to any one of claims 1-4, wherein the protective device further comprises an end tube, one end of the protective ring being connected to the end tube for fixed connection to a distal end of the outer tube proximate the needle.

6. The endoscopic surgical instrument according to claim 5, wherein the outer surface of the end tube is formed with barbs or threaded raised structures for securing the end tube to the inner wall of the outer tube.

7. The endoscopic surgical instrument according to claim 5, wherein one end portion of the end tube is formed with a flange for limiting and the flange abuts against an end face of the distal end portion of the outer tube.

8. The endoscopic surgical instrument according to claim 6, wherein one end portion of the end tube is formed with a flange for limiting and the flange abuts against an end face of the distal end portion of the outer tube.

9. A protective device for an endoscopic surgical instrument, the endoscopic surgical instrument comprising a needle having a needle tip, wherein the protective device comprises a protective ring, a ring wall of the protective ring being formed with a discontinuous or thinned structure of material in a direction of an axial direction of the protective ring, wherein:

the thinning structure includes at least one groove formed on an outer surface of a wall of the guard ring such that the wall of the guard ring has a smooth inner surface relative to a tip of the needle.

10. The protective device of claim 9, wherein the plurality of slits extend at least in the circumferential direction of the protective ring and are staggered such that slits adjacent in the axial direction of the protective ring are offset from each other in the circumferential direction of the protective ring.

11. The protective device of claim 10, wherein the plurality of slots extend in a direction parallel to a circumference of the protective ring.

12. The protective apparatus according to claim 11, wherein the width of the slit is 0.05mm or less, and a pitch of the slits adjacent in an axial direction in the axial direction is 0.2mm or less.

13. The protective device of claim 12, wherein the plurality of slots have the same length and the length is equal to or greater than one-fourth of a circumference of the protective ring.

14. The protective apparatus of claim 9, wherein the at least one groove extends at least in a circumferential direction of the protective ring.

15. The protective apparatus of any one of claims 9-14, wherein the protective apparatus further comprises an end tube, one end of the protective ring being connected to the end tube.

16. The protector of claim 15, wherein the outer surface of the end tube has a barb or threaded boss structure formed thereon for securing the end tube to the inner wall of the member receiving the end tube.

17. The protector of claim 15, wherein one end of the end tube is formed with a flange for limiting.

18. The protector of claim 16, wherein one end of the end tube is formed with a flange for limiting.