The present invention relates to a minimally invasive surgical instrument, and in particular, to a trocar sealing element.
A trocar is a surgical instrument, that is used to establish an artificial access in minimally invasive surgery (especially in rigid endoscopy). Trocars comprise in general a cannula and an obturator. The surgical use of trocars generally known as: first, make the initial skin incision at the trocar insertion site, then insert the obturator into the cannula, and then together they facilitated penetration of the abdominal wall through incision into the body cavity. Once penetrated into the body cavity, the obturator is removed, and the cannula will be left as access for the instrument get in/out of the body cavity.
In rigid endoscopy surgery, it is usually necessary to establish and maintain a stable pneumoperitoneum for the sufficient surgical operation space. The cannula comprises a sleeve, an outer body, a seal membrane (also known as instrument seal) and a duck bill (also known as closure valve). Said cannula providing a channel for the instrumentation in/out of the body cavity, said outer body connecting the sleeve, the duck bill and the seal membrane into a sealing system; said duck bill normally not providing sealing for the inserted instrument, but automatically closing and forming a seal when the instrument is removed; said seal membrane accomplishing a gas-tight seal against the instrument when it is inserted.
In a typical endoscopic procedure, it is usually set up 4 trocars (access), i.e. 2 sets of small diameter cannula (normally 5 mm in diameter), and 2 sets of large diameter cannula (normally 10˜12 mm in diameter). Instruments, in general passing through a small cannula are only for ancillary works; herein one large cannula as an endoscope channel, and the other large cannula as the main channel for surgeon to perform surgical procedures. Through said main channel thereof, 5 mm diameter instruments used in approximately 80% of the procedure, and said large cannula used in approximately 20% of the procedure; furthermore, 5 mm instruments and large diameter instruments need to be switched frequently. The small instruments are mostly used, so that the sealing reliability of which is more important. The large instruments are more preferably used in a critical stage of surgery (such as vascular closure and tissue suturing), therein switching convenience and operational comfort are more important.
As illustrated in
As illustrated in
As illustrated in
The instrument inserted into the sealing membrane and moved during surgical procedure, there is large frictional resistance between the wrapped area and the inserted instrument. Said large frictional resistance is normally easy to cause the seal inversion, poor comfort of performance, fatigue performance, even result in cannula insecurely fixed on the patient's abdominal wall etc., such that the performance of cannula assembly is affected.
Among the defects caused by the large frictional resistance, the seal inversion is one of the most serious problems that affecting the performance of the cannula. As illustrated in
There are many factors affecting the frictional resistance, and the comprehensive effects of various factors must be considered in the perspective of mechanics and tribology. The seal membrane is preferably produced from rubber such as natural rubber, silicone or polyisoprene, its mechanical properties including super elastic and viscoelastic. Although the mechanical model of the rubber deformation process is complicated, it can still apply the generalized Hooke's law to describe approximately its elastic behavior, and Newton's internal friction law to describe the viscous behavior. Research suggests that the main factors affecting the friction of the two surfaces in contact between the rubber and the instrument include: the smaller the friction coefficient of said two surfaces, the smaller the friction is; the better lubrication condition of said two surfaces in contact, the friction smaller is; the smaller normal pressure of said two surfaces, the friction smaller is. Comprehensively considering the above factors, the present invention proposes better solutions for reducing the frictional resistance between the seal membrane and the inserted instrument.
In addition to said frictional resistance greatly affecting the performance of the cannula assembly, the stick-slip of the seal membrane is another main factor affecting the performance of trocar. Said stick-slip means that when the instrument moves longitudinally in the sleeve, the sealing lip and lip-adjacent area sometimes are relatively statically attached to the instrument (at this point, the friction between the instrument and the seal membrane is mainly static friction.); but sometimes it produced a relatively slippery phenomenon with the instrument (at this point, the friction between the instrument and the seal membrane is mainly dynamic friction.); and said static friction is much greater than said dynamic friction. The two frictions alternately occur, which causes the movement resistance and speed of the instrument in the seal membrane to be unstable. It is easy to be understood for those skilled in the art, that in minimally invasive surgery the surgeon can only use surgical instruments to touch (feel) the patient's organs and observe a part of the working head of the instruments through endoscopic image system. In this case where the vision is limited and it cannot be touched, the surgeon typically uses the feedback of the resistance when moving instruments as one of the information to judge whether the operation is abnormal nor not. The stick-slip affects the comfort of operation, the accuracy of positioning, and even induces the surgeon to make false judgment.
During the surgical application of the cannula, the stick-slip is difficult to avoid, but can be reduced. Researches have shown that said stick-slip is affected by two main factors: one is that the smaller the difference between the maximum static friction and the dynamic friction, the weaker the stick-slip is; the other is that the larger the axial tensile stiffness of the seal membrane, the weaker the stick-slip is. Avoiding excessive the hoop force between the seal membrane and the instrument, reducing the two surfaces contacted, maintaining good lubrication, respectively, can reduce the difference between the maximum static friction and the dynamic friction, thereby reducing stick-slip, meanwhile, increasing the axial tensile stiffness of the seal membrane also helps to reduce the stick-slip phenomenon. The invention also proposes measures for improving stick-slip.
A pleated seal membrane is disclosed in U.S. Pat. No. 7,789,861 (Chinses Patent Family CN101478924B). As illustrated in
The geometry of the pleats (89) can be designed to minimize or eliminate hoop stress in the pleated portion of the seal membrane 80 when an instrument is introduced. This geometric relationship, herein conforms to the following equation:
h=pleat wall height as a function of radius
r=radius
ri=the largest radius designed for the insertion through the seal membrane
rid=radius at inside diameter of pleat section of the seal membrane
P=number of pleats
In the embodiment disclosed in U.S. Pat. No. 7,798,671, the inner diameter of the opening 81 in the relaxed state is between 3.8˜4.0 mm. The elasticity of the seal membrane 80 is sufficient to ensure that the opening 81 can be expanded to gas-tightly engage a surgical instrument with 12.9 mm diameter. The seal membrane 80 contains 8 linear pleats 89. Therefore, h in this embodiment should conform to the following formula:
h≥3.14/8√{square root over (r2+(6.45)2−22)}
Theoretically increasing the number of pleats 89 can reduce said h. In the prior art described above, the non-pleated seal membrane is usually designed to have the thickness of the wall 0.5 to 0.7 mm. If a pleated seal membrane is used to reduce the hoop force, it is advantageous to use thicker pleat walls. That is, if the thickness of the seal membrane is greater than 0.5, the number of pleats is usually not more than 8, otherwise it cannot be manufactured. The circumference of the opening 81 is usually 11.9˜12.5 mm diameter, and the thickness of each pleat wall is usually not less than 0.5 mm. 8 pleats have 16 pleat walls in total, and more pleats will make manufacturing very difficult or impossible to manufacture. Therefore, the manufacturable seal membrane conforming to this formula has h≥2.4 mm.
The schematic diagram of the seal membrane in the U.S. Pat. No. 7,789,861 does not conform to the above formula. As illustrated in
Refer to
Refer to
Refer to
In summary, the pleated trocar seal disclosed in U.S. Pat. No. 7,789,861 is not incomplete. Further analyzing the complexity of the clinical application of the trocar, and comprehensively considering effects of various factors, the invention proposes improved pleated trocar seal.
In conclusion, one object of the invention is to provide a trocar seal membrane, said seal membrane comprises a proximal opening, a distal aperture, a sealing lip, and a sealing wall from the distal aperture extending to the proximal opening, said distal aperture formed by a sealing lip for accommodating the inserted instrument and forming a gas-tight seal. Said the sealing wall includes a proximal surface and a distal surface. Said seal membrane can ensure a reliable seal for the inserted 5 mm instrument, and reduce frictional resistance and improve stick-slip when a large-diameter instrument is inserted.
As described in the background, the wrapped area formed by the sealing lip and the lip-adjacent area when a large diameter instrument inserted, is the major factor cause of frictional resistance. For reducing said frictional resistance, comprehensive consideration should be given such as reducing the radial stress between the instrument and the seal membrane, reducing said wrapped area, and reducing the actual contact area of the two surfaces. It is easy to understand for those skilled in the art that in accordance with the generalized Hooke's law and Poisson effect, enlarge hoop circumference, and reduce hoop strain (stress), thereby reducing radial strain (stress). But it should be noted that it is impossible to enlarging the hoop circumference in order to reduce the strain of the sealing lip which will result in reduced sealing reliability when applying 5 mm instruments. Since the stress in the lip-adjacent area is highly concentrated when applying a large diameter instrument, the hoop circumference of the lip-adjacent area should be rapidly increased. In regard to outside the lip-adjacent area, since the strain (stress) is small, it is not necessary to adopt measures to enlarge the hoop circumference. In addition, enlarging the hoop circumference, in the meantime increasing the axial tensile stiffness in the lip-adjacent area and maintain good lubrication (reducing difference between the maximum static friction and dynamic friction), thereby the stick slip in the lip-adjacent area is improved.
In one aspect of the present invention, said seal membrane comprises a proximal opening, a distal aperture, and a sealing wall from the distal aperture extending to the proximal opening, said distal aperture formed by a sealing lip for accommodating the inserted instrument and forming a gas-tight seal. Said sealing lip comprises a longitudinal axis and a transverse plane substantially perpendicular to said axis. Said sealing wall comprises a plurality of pleats extending laterally from the sealing lip. Each said pleat comprises a pleat peak, a pleat valley and a pleat wall extending there between. And in the lip-adjacent area, the depth of the pleat wall gradually increases along the longitudinal axis; while outside the lip-adjacent area, the depth of which gradually decreases along the longitudinal axis.
Alternatively, the angle between said pleat peak and said pleat valley relative to said transverse plane conforms to the following equation:
tan=tan function
cos=cosine function
P=number of pleats
R=The distance from the pleat as the starting point for measurement to the central axis of the sealing lip
Ri=the largest radius designed for the surgical instrument through the seal membrane
β=the angle between the pleat peak and the transverse plane
α=the angle between the pleat valley and the transverse plane
By theoretical analysis and related research, it is shown that reducing the value of the guiding angle α is advantageous for reducing the length of said wrapped area. In an optional embodiment, 8 pleats are adopted; the angle between said pleat valley and the transverse plane is 0°≤α≤25°. In another optional embodiment, thickened pleat peaks are adopted. Said thickened pleat peak, that is, the thickness of the wall at the pleat peak is greater than the thickness of the pleat wall. The thickened pleat peak acts as reinforcing ribs, a plurality of thickened pleat peaks together to strengthen the axial tensile stiffness of the sealing wall. Since the pleats enlarge the hoop circumference in the lip-adjacent area, the thickened pleat peaks enhance the axial tensile stiffness without significantly increasing the hoop tensile stiffness; that is, increasing the axial stiffness without increasing the hoop force, such that which can effectively reduce the stick-slip described in the background.
In another aspect of the present invention, said seal membrane comprises a proximal opening, a distal aperture, and a sealing wall from the distal aperture extending to the proximal opening; said distal aperture formed by a sealing lip for accommodating the inserted instrument and forming a gas-tight seal; said sealing lip, which is cylindrical, comprises a longitudinal axis and a transverse plane substantially perpendicular to said axis. Said sealing wall comprises a plurality of pleats extending laterally from the sealing lip; each said pleat comprises a pleat peak, a pleat valley and a pleat wall extending there between. Said seal membrane comprises a flange and a conical sidewall extending from the flange; said conical sidewall and said pleat are intersected. When said pleats extending laterally outward, in the lip-adjacent area the depth of said pleats gradually increases along the longitudinal axis; outside the lip-adjacent area the depth of said pleats gradually decreases along the longitudinal axis. Said seal membrane also includes an outer floating portion extending from the flange to the proximal opening. Optionally, the thickness of the conical sidewall is less than the thickness of the pleat wall.
The other object of the invention is to provide a trocar seal assembly. Said seal includes a lower retainer ring, a seal membrane, a protector, an upper retainer ring, an upper body, an upper cover; said seal membrane and said protector device are sandwiched between the upper retainer ring and the lower retainer ring, said 4 mutually overlapping protectors used to protect the seal membrane from sharp edges of the inserted instrument. The proximal opening of said the seal membrane sandwiched between the upper body and the upper cover, said outer floating portion makes the seal membrane and protector float laterally in the housing formed by the upper body and the cover.
It is believed that the above invention or other objects, features and advantages will be understood with the drawings and detailed description.
A more complete appreciation of this invention, and many of the attendant advantages thereof will be readily apparent as the same becomes better understood by reference to the following detailed description, where:
In all views, the same referred number shows the same element or assembly.
Embodiments of the invention are disclosed herein, however, it should be understood that the disclosed embodiments are merely examples of the invention, which may be implemented in different ways. Therefore, the invention is not intended to be limited to the detail shown, rather, it is only considered as the basis of the claims and the basis for teaching those skilled in the art how to use the invention.
Said seal membrane 330 includes a proximal opening 332, a distal end aperture 333, and the sealing wall extending from the distal end to the proximal end, said sealing wall including a proximal surface and a distal surface. Said aperture 333 formed by a sealing lip 334 for accommodating an inserted instrument and forming a gas-tight seal. Said sealing lip 334 may be non-circular. As described in the background of the invention, the circumference of the sealing lip should be short and strong enough to ensure sealing reliability when a 5 mm diameter instrument is inserted. In the present embodiment, the sealing lip 334 is circular, defining its radius as Rlip, so that the circumference of the sealing lip is approximately equal to 2*Rlip*π (π=3.14159), usually the circumference of the sealing lip is 11.8˜13.8 mm. The cross-section of said sealing lip is circular, usually its radius is 0.7 to 1.0 mm diameter.
Said the seal membrane 330 also including the flange 336; The sealing wall 335 has one end connected to the sealing lip 334 and the other end connected to the flange 336; a floating portion 337 has one end connected to the flange 336 and the other end connected to said proximal end 332. Said flange 336 can be applied for mounting the protector device 360. Said floating portion 337 including one or several plurality of radial (lateral) pleats such that the entire seal membrane assembly 380 can float in the assembly 300.
Said assembly 380 can be made from a variety of material s with a range of different properties. For instance, said seal membrane 330 is made of a super elastic material such as silicone or polyisoprene; said protector device 360 is made of a semi-rigid thermoplastic elastomer; and said lower retainer ring 320 and said upper retainer ring 370 are made of a relatively hard rigid material such as polycarbonate.
Said sealing lip 134 comprising a longitudinal axis 158, and a transverse plane 159 that is generally perpendicular to the longitudinal axis 158. Said sealing wall 335 includes a plurality of pleats 340. The pleats 340 and the sealing lip 334 are circumscribed and extend laterally away from the axis 358. Said pleats 340 include pleat valleys 342a, 342b; pleat peaks 343a, 343b; and a pleat wall 341. Sealing wall 335 includes 8 said linear pleats 340, in the present embodiment, although a more or less number of pleats can be employed. In the present embodiment, said pleats 340 are conically arranged around the sealing lip 334. Said pleats 340 intersect the flange 336 and its extended wall 338 to form an intersection line 345a, 345b. A part of the frustum wall 339 intersects the pleat wall 341 to form an intersection line 344a, 344b; The frustum wall 339 intersects the extended wall 338 to form an intersection line 346a, 346b. Defining the angle between the pleat valley 342a (342b) and the transverse plane surface 359 as a guide angle α; Defining the angle between the pleat peak 343a(343b) and the transverse plane surface 359 as a guide angle β; Defining the angle between the pleat valley 342a (342b) and the pleat peak 343a (343b) as a wave angle θ; and ranges of them are from 0° to 90°.
When the pleats 340 extending laterally outward, in the lip-adjacent area, the depth of said pleat wall 341 gradually increases along the longitudinal axis; outside the lip-adjacent area the depth of said pleats 341 gradually decreases along the longitudinal axis. The height of the pleat wall can be measured along the wall surface between the pleat valley 342a (342b) and the pleat peak 343a (343b).
Taking the longitudinal axis 358 as a rotary axis, making a cylindrical surface (not shown) with a radius RI divides the seal membrane 330 into an inner portion 356 (as in
As shown in
In an optional embodiment, thickened pleat peaks are adopted. Said thickened pleat peak, that is, the thickness of the wall at the pleat peak is greater than the thickness of the pleat wall. Said thickened pleat peak has the function of reinforcing ribs. In this embodiment, 8 thickened pleat peaks act as 8 reinforcing ribs, together to strengthen the axial tensile stiffness of the sealing wall 335. Since said pleats 340 enlarge the hoop circumference in the lip-adjacent area, the thickened pleat peaks enhance the axial tensile stiffness without significantly increasing the hoop tensile stiffness; that is, increasing the axial stiffness without increasing the hoop force, such that which can effectively reduce the stick-slip described in the background. In this embodiment, there are 8 thickened pleat peaks, while more or less which also can increase the axial tensile stiffness.
In summary, said pleats has the functions of enlarging hoop circumference, reducing the wrapped area, reducing the actual contact area of the two surfaces between the instrument and the seal membrane, increasing the axial tensile stiffness, etc., and therefore the frictional resistance and the stick-slip can be greatly reduced, and the probability of inversion is reduced.
As described in the background, when a 5 mm diameter instrument is inserted, it is considered only relying on the hoop force of the sealing lip to ensure sealing reliability. Therefore, it is not possible to reduce hoop strain (stress) by enlarging hoop circumference of the sealing lip when a large diameter instrument is inserted, however, the method of enlarge the hoop circumference can be used to reduce hoop strain (stress) in the lip-adjacent area. The strain in the lip-adjacent area is larger (high concentration stress area), and the closer to the sealing lip, the greater the strain (stress), and the closer to the sealing lip, the greater the strain (stress). Therefore, it is necessary to rapidly enlarging hoop circumference in the lip-adjacent area. However in the present embodiment, the larger the pleat angle θ, the rate of the hoop circumference in the lip-adjacent area enlarges. The pleat angle θ is the guide angle α, the guide angle β, and the number of pleats P, and conform to the following equation.
cos θ=cos α cos β cos(180/P)+sin α sin β
cos=cosine function
sin=sin function
P=number of pleats
α=the angle between the pleat valley and the transverse plane
β=the angle between the pleat peak and the transverse plane
θ=the angle between the pleat peak and the pleat valley
Theoretically, the larger θ is, the better. That is it can quickly enlarge the hoop circumference in the lip-adjacent area, so the hoop force in pleats is fast minimized; while said hoop force is not the only factor that causes the frictional resistance to be large in the background. Rapidly reducing the hoop force in pleats, it is also necessary to comprehensively consider reducing the wrapping area and reducing the actual contact area of the two surfaces between the instrument and the seal membrane. By theoretical analysis and related research, it is shown that reducing the value of the guiding angle of the pleat wall in the lip-adjacent area (in this embodiment the guiding angle of the pleat wall is defined by the pleat valley guiding angle α and the pleat peak guiding angle β) is advantageous for reducing said wrapped area, but too small guiding angle will sacrifice the guiding performance of the seal membrane, therefore, when determining the value of the guiding angle, the smaller value should be taken as far as possible under the premise of satisfying the guiding performance.
According to the above equation, when the difference value (D-value) between α and β is the smallest, the equation on the right side of the equal sign takes the maximum value, that is, θ takes the minimum value. When the difference value between α and β is larger, the θ become larger. A smaller guide angle is advantageous to reduce the wrapped area. It is necessary to satisfy a large θ angle as well as satisfying a small introducing angle, so the smaller the angle α, the better. When the value of the angle α is determined, the value of β is selected according to the rate of increase of the circumferential circumference required for the design, that is, β is determined by the rate at which the height of the pleat wall increases. Optionally, in one embodiment, the geometric relationship of the pleats conforms to the following equation:
tan=cosine function
cos=cosine function
P=number of pleats
R=The distance from the pleat as the starting point for measurement to the central axis of the sealing lip
Ri=the largest radius designed for the surgical instrument through the seal membrane
β=the angle between the pleat peak and the transverse plane
α=the angle between the pleat valley and the transverse plane
It can be understood according to the above equation that a reasonable combination of R, α, β, P can make the region laterally outward from the measurement point, the change of which shape is mainly manifested by the local macroscopic displacement of the material, the produced strain (stress) is mainly manifested by local bending deformation, rather than the overall microscopic molecular chain elongation, thereby reducing the hoop force in a large extent. It can be understood according to the above equation that the larger the number of pleats P, the smaller the values of α, β angle can be selected, but in actual manufacturing, usually no more than 8 pleats, more pleats will make manufacturing very difficult or impossible to manufacture. Normally 2.5 mm≤R≤(Ri+R0)/2; Normally 2.0 mm≤R0≤2.2 mm: If the value of R is less than 2.5 mm, the transition area at the sealing lip will be too large; if the value of R is greater than (Ri+R0)/2, the effect of enlarging the hoop circumference in the lip-adjacent area and reducing the hoop force is not obvious. Optionally, the number of pleats P=8; the largest radius designed for the surgical instrument through the seal membrane Ri=6.45; the range of values is 3≤R≤4.
When R=3, α=0°, then β≥36.8°;
When R=3, α=20°, then β≥48.6°;
When R=3, α=25°, then β≥50.6°;
When R=3, α=30°, then β≥53°;
When R=4, α=0°, then β>31.5°;
When R=4, α=20°, then β≥44.4°;
When R=4, α=25°, then β≥47.20°;
When R=4, α=30°, then β≥50°.
Usually β should be less than or equal to 50°, and a larger β causes said wrapped area to increase. The above theoretical calculations have shown that with R (3≤R≤4) as the radius cylindrical surface intersects with pleats, when a large diameter instrument is inserted, pleats deformation in the inside of the cylinder is shown as the comprehensive effect of overall tensile deformation and local bending deformation; while the material of pleats in the outside of the cylinder is mainly manifested by local bending deformation and the overall displacement. When α>25°, to achieve the aforementioned effect, β should be greater than 50°, which will cause the wrapped area to be too large. Therefore, it is appropriate to be 0≤α≤25°.
Defining the axis of said sealing lip 434 as the longitudinal axis 458, and a transverse plane 459 that is generally perpendicular to the longitudinal axis 458. Said sealing wall 435 includes a plurality of pleats 440. The pleats 440 and the sealing lip 434 are circumscribed and extend laterally away from the axis 458. Said pleats 440 include pleat valleys 442a, 442b; pleat peaks 443a, 443b; and a pleat wall 441. Sealing wall 435 includes 8 said linear pleats 440, in the present embodiment, although a more or less number of pleats can be employed. Said pleats 340 and the frustum wall 439 extend to be intersected and form an intersection line 444a, 444b; the frustum wall 339 and said flange 436 extend to be intersected.
When the pleats 340 extending laterally outward, the depth of said pleat wall 441 gradually increases along the longitudinal axis (in the lip-adjacent area the depth of pleats gradually increases), and then gradually decreases along the longitudinal axis (outside the lip-adjacent area the depth of said pleats gradually decreases). The height of the pleat wall can be measured along the wall surface between the pleat valley 442a (442b) and the pleat peak 443a (443b).
Said lip 434 has a cylindrical portion, which when intersected with the pleats 89 results in a line 445a, 445b; said line 445a (445b) defines a triangular region 338 pointing distally to the tip, corresponding to each peak 443a (443b).
In an optional embodiment, thickened pleat peaks are adopted. Said thickened pleat peak, that is, the thickness of the wall at the pleat peak is greater than the thickness of the pleat wall. Said thickened pleat peak has the function of reinforcing ribs. In this embodiment, 8 thickened pleat peaks act as 8 reinforcing ribs, together to strengthen the axial tensile stiffness of the sealing wall 435. Since said pleats 440 enlarge the hoop circumference in the lip-adjacent area, the thickened pleat peaks enhance the axial tensile stiffness without significantly increasing the hoop tensile stiffness; that is, increasing the axial stiffness without increasing the hoop force, such that which can effectively reduce the stick-slip described in the background. In this embodiment, there are 8 thickened pleat peaks, while more or less side walls also can increase the axial tensile stiffness. While the thickness of said frustum wall 439 is much smaller than the thickness of the pleat wall 441, which is mainly to reduce the deformation force outside the lip-adjacent area. When the seal membrane 440 is used in conjunction with the aforementioned protection device 160, the instrument is unlikely to contact said frustum wall 439, so a thinner thickness can be used without fear of damage to the seal membrane; said thicken pleat valley plays a role in increasing the axial tensile stiffness of the sealing wall 435, and therefore a thinner frustum wall 439 can be used to reduce the stress generated by the frustum wall 439 relative to the flange rotation and bending deformation when the sealing lip and its adjacent area are diastolic.
Likewise, said pleats has the functions of enlarging hoop circumference, reducing the wrapped area, reducing the actual contact area of the two surfaces between the instrument and the seal membrane, increasing the axial tensile stiffness, etc., and therefore the frictional resistance and the stick-slip can be greatly reduced, at the same time, the probability of inversion is reduced or the operational comfort of the seal membrane after inversion can be improved.
It will be readily apparent to those skilled in the art that a reasonable fillet transition can avoid stress concentration or easier deformation of certain areas. Since the diameter of the seal membrane is small, especially the diameter of the area near the sealing lip is smaller, such a small diameter and different chamfers that the appearance of the seal membrane looks different. In order to clearly show the geometric relationship of elements, the embodiment of the description in the invention is generally the graphics after removing fillet.
Many different embodiments and examples of the invention have been shown and described. Those ordinary skilled in the art will be able to make adaptations to the methods and apparatus by appropriate modifications without departing from the scope of the invention. The structure and the manner of fixing of the protector assembly disclosed in U.S. Pat. No. 7,788,861 are used in the example of the present invention. However, the structure and the manner of fixing of the protector assembly disclosed in U.S. Pat. No. 7,798,671 can be used, and in some applications, the protector assembly may not be included. It has been mentioned many times in the invention that the concave-furrow extends laterally outward from the sealing lip, and the so-called “extending laterally outward” should not be limited to a straight line. Said “extending laterally outward” can be a spiral, a line segment, a multi-section arc line and so on. In the invention, the positional relationship of the intersecting surfaces composed of said concave-furrow and the intersection line thereof are described with reference to specific embodiments, and the methods of increasing curved surfaces to form a multifaceted mosaic or using of the high-order curved surface to make the intersection line and the concave-furrow shape to look different from said embodiment. However, it can be considered not deviated from the scope of the invention, as long as it conforms to the general idea of the invention. Several modifications have been mentioned, to those skilled in the art, other modifications are also conceivable. Therefore, the scope of the invention should follow the additional claims, and at the same time, it should not be understood that it is limited by the specification of the structure, material or behavior illustrated and documented in the description and drawings.
Number | Date | Country | Kind |
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201610622195.2 | Aug 2016 | CN | national |
This application is a continuation of International Patent Application No. PCT/CN2017/093601 with a filing date of Jul. 20, 2017, designating the United States, now pending, and further claims priority to Chinese Patent Application No. 201610622195.2 with a filing date of Aug. 2, 2016. The content of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/CN2017/093601 | Jul 2017 | US |
Child | 16249898 | US |