JP5798417B2 - Retractor - Google Patents

Description

  The present invention relates to a retractor that protects an incision during surgery.

  As a retractor, a pair of flange-like rings are connected to the peripheral edges of both ends of the cylindrical silicone rubber membrane on the inner circumference side, and one of the flange-like rings is inserted into the abdominal cavity from the incision so that the abdominal wall is There is one that is sandwiched by a flange-shaped ring from the inside and outside of the body and holds the incision in an expanded state by the expansion force of the silicone rubber film (for example, Patent Document 1).

  Such a retractor cannot be used for patients with a thick abdominal wall because the length between the two flanged rings is fixed, and there is a gap between the abdominal wall and the ring for patients with a thin abdominal wall. Therefore, there is a problem that the attachment of the retractor to the incision becomes unstable and the incision cannot be properly protected.

  On the other hand, Patent Document 2 discloses a retractor in which annular members are attached to both ends of a cylindrical flexible sleeve. In the retractor, the body inner annular member is inserted into the abdominal cavity, the outer body annular member is twisted, and the flexible sleeve is wound around the annular axis of the body outer annular member. The length of can be adjusted.

Utility Model Registration No. 30602106 Special table 2010-526603

  In the retractor of Patent Document 2, the flexible sleeve is prevented from being unwound from the outer annular member in a state where the outer annular member around which the flexible sleeve is wound is set on the abdominal wall surface of the subject. For this reason, the torsional rigidity of the outer annular member must be increased. However, the high torsional rigidity makes it difficult to twist the outer annular member when the operator winds the flexible sleeve around the outer annular member for length adjustment. This increases the operating force at the time.

  An object of the present invention is to provide a retractor capable of generating sufficient torsional rigidity when the operating force of the annular member is released while securing the ease of twisting of the annular member when adjusting the length between the annular members. Is to provide a vessel.

  The retractor according to the present invention includes a cylindrical flexible sleeve that is open at both ends, and an inner side in which a peripheral edge of the one end side opening is fixed so as to hold one end side of the flexible sleeve in an open state. An annular member and a peripheral edge of the opening on the other end side are fixed so as to hold the other end of the flexible sleeve in an open state, and the flexible sleeve is moved by reversing the inner and outer circumferences by twisting. A body outer ring member that can be wound and unwound in a twisting direction, and the body outer ring member has a block portion and an elastic stretchable portion connected in an alternating arrangement in the circumferential direction, and the elastic stretchable portion is The block portions are separated from each other in the circumferential direction during expansion, and the block portions are brought into contact with each other in the circumferential direction during reduction.

  According to the present invention, when the force that expands the outer annular member radially outward acts on the outer annular member, the elastic expansion and contraction portion expands, and the block portions adjacent to each other in the circumferential direction are separated in the circumferential direction. . Thereby, since the twist resistance between block parts is cancelled | released, a body outer side annular member becomes easy to twist. As a result, the operator can smoothly wind or unwind the flexible sleeve around the outer ring member. On the other hand, when there is no operating force to expand the body-side annular member outward in the radial direction, the elastic expansion / contraction part contracts due to the restoring force, and the block parts contact each other in the circumferential direction. Thereby, the torsional rigidity of the outer annular member is increased. Accordingly, when the operating force applied to the outer ring member is released after the elastic expansion / contraction part is wound around the outer ring member, the outer ring member is reversed inside and outside, and the flexible sleeve is removed from the outer ring member. Unwinding can be prevented.

  In one example, the block portions are set to a size and a shape that allow a contact force to produce a torsional rigidity of a predetermined value or more between the block portions when contacting each other in the circumferential direction.

  By setting the shape and size of the block part to obtain a predetermined contact force at the time of mutual contact in the circumferential direction, a desired torsional rigidity is generated in the outer annular member when the elastic expansion / contraction part is reduced. be able to.

In one example, the block portion has a polygonal shape in a torsional cross section ( a cross section when viewed in the circumferential direction of the body outer ring member) of the body outer ring member .

  By making the cross-section of the block portion a polygonal cross-section, when the outer body annular member is set on the abdominal surface of the subject in a contracted state, each block portion becomes difficult to perform inner and outer periphery inversion due to the presence of the corner portion. . Thereby, it is possible to effectively prevent the flexible sleeve from being unwound from the outer annular member when the retractor is set.

In one example, the block part and the elastic stretchable part are both rectangular in cross section in the torsional direction of the body outer ring member (cross section when viewed in the circumferential direction of the body outer ring member). And the long side of the rectangular cross section of the elastic stretchable part is substantially the same as the length between one opposite side of the rectangular cross section of the block part. The short side of the rectangular cross section of the elastic stretchable part is shorter than the length between the opposite sides of the rectangular cross section of the block part.

  By forming the elastic stretchable portion in a band shape, the inner peripheral side portion is sufficiently reduced in the reduced state where the elastic stretchable portion has both sides in the long side direction of the rectangular cross section as the inner and outer peripheral sides of the outer annular member. On the other hand, the outer peripheral side portion is not sufficiently reduced, and a difference occurs in the circumferential reduction force between the inner peripheral side and the outer peripheral side. This difference becomes unstable as a position in the torsional direction because it acts as a torsional force that eliminates the difference when the body-side annular member is slightly twisted. On the other hand, in the contracted state in which the elastic expansion / contraction part has both sides in the short side direction of the rectangular cross section directed to both sides in the axial direction of the outer annular member, the circumferential contraction force is equal on the inner peripheral side and the outer peripheral side. This equivalent state acts as a torsional force that attempts to return to the equivalent state even if the body-side annular member is slightly twisted. Therefore, when the outer ring member is set on the abdominal surface of the subject in a contracted state, the elastic expansion and contraction portion is in a contracted state in which both sides in the width direction are directed to both sides in the axial direction of the outer ring member, so that flexibility It is possible to effectively prevent the sleeve from unwinding from the outer annular member.

  In one example, the outer annular member has a blocking member between the block portions that prevents the flexible sleeve from entering between the block portions.

  Torsion of the outer annular member is performed in a state where the block portion is separated in the circumferential direction and the torsional rigidity of the outer annular member is reduced. At this time, a flexible sleeve is placed in the gap between the block portions. When it enters, the flexible sleeve is sandwiched between the block portions when the elastic expansion and contraction portion is reduced. The pinching of the flexible sleeve between the block portions makes it easy to slip between the block portions when the elastic expansion and contraction portion is reduced, and also narrows the inner diameter of the flexible sleeve to inhibit smooth extension between the block portions. The operability of twisting of the outer annular member is deteriorated. On the other hand, the blocking member prevents the flexible sleeve from entering the gap between the block portions when the elastic expansion / contraction portion expands in the circumferential direction, thereby preventing the flexible sleeve from entering the gap between the block portions. The sleeve is accurately prevented from being caught.

The perspective view of a retractor. The figure which shows a body outer side annular member in the expansion state to radial direction. The figure which shows a body outer side annular member in the contraction state to a radial direction. The figure which shows the torsion direction cross section and contact surface between the square blocks of a body outer side annular member. Explanatory drawing when attaching a retractor to a test subject's abdominal wall. FIG. 3 is a structural diagram of an outer body annular member obtained by partially improving the outer body annular member of the retractor of FIG. 1.

  The structure of the retractor 1 will be schematically described with reference to FIG. The retractor 1 is fixed to the inner periphery or the outer periphery of the body outer ring member 2 and the body inner ring member 3 with the outer peripheral ring member 2 and the body inner ring member 3 at both ends in the axial direction, and the opening peripheral edges of both ends in the axial direction. And a flexible sleeve 4.

  Both the body outer ring member 2 and the body inner ring member 3 are elastically deformable by a predetermined external force, and are circular in a free state. Typically, the body outer ring member 2 and the body inner ring member 3 are formed. Are circular with the same diameter. The body inner annular member 3 is composed of one member, and the shape of the cross section in the direction perpendicular to the annular axis is typically circular.

  The flexible sleeve 4 is configured such that the outer peripheral member on the outer annular member 2 side is outside the body by repeating reversal in one direction or the other of the inner and outer periphery of the outer annular member 2 around the annular axis of the outer annular member 2. The annular member 2 is wound or unwound. The flexible sleeve 4 is typically made of a thin material that is transparent and easy to wind and unwind around the outer annular member 2 and is strong. The axial length between the outer annular member 2 and the inner annular member 3 is adjusted by increasing or decreasing the amount of winding of the block portion around the outer annular member 2.

  With reference to FIG.2 and FIG.3, the structure of the body outer side annular member 2 is demonstrated. As will be described later, the body-side annular member 2 can be expanded and contracted in the radial direction by expansion and contraction of the belt-like elastic body 22, and FIG. 2 and FIG. It shows a state in an expanded state and a contracted state. In FIG. 2, (a) is the figure which looked at the body outer side annular member 2 in the axial direction of the retractor 1, and (b) is the figure which looked at the body outer side annular member 2 from the side of the retractor 1. FIG. 3 is a view of the outer annular member 2 as seen from the axial direction of the retractor 1.

  The body outer annular member 2 includes a rectangular block 21 and a belt-like elastic body 22 that are connected to each other in an alternating arrangement in the circumferential direction. The rectangular block 21 is substantially rigid, and the belt-like elastic body 22 is elastically stretchable and elastically twistable.

  In the rectangular block 21, two side surfaces on both sides in the circumferential direction of the body-side annular member 2 are referred to as contact side surfaces 23, and four side surfaces around the annular axis of the body-side annular member 2 are referred to as circumferential side surfaces 24. To do. The arc-shaped chamfer 25 is formed at the boundary between the peripheral side surfaces 24. The rectangular block 21 has a substantially cubic shape or a substantially rectangular parallelepiped shape that is long in the circumferential direction or the radial direction of the outer annular member 2.

  When the belt-like elastic body 22 is extended, the rectangular blocks 21 are separated in the circumferential direction, and the contact side surfaces 23 of the rectangular blocks 21 adjacent to each other in the circumferential direction are not in contact with each other. Therefore, the torsional rigidity or torsional resistance force of the body outer annular member 2 is small.

  When the belt-like elastic body 22 is reduced in the circumferential direction of the outer annular member 2, the rectangular blocks 21 approach in the circumferential direction, and the rectangular blocks 21 adjacent to each other in the circumferential direction are in contact with each other on the contact side surface 23. become.

  4A shows a torsional cross section between the square blocks 21 when the body-side annular member 2 is radially expanded, and FIG. 4B shows a contact side surface when the body-side annular member 2 is radially contracted. 23 shows the contact area. In FIG. 4, the left and right peripheral side surfaces 24 are the outer peripheral side and the inner peripheral side of the body-side annular member 2, respectively.

  In FIG. 4, the belt-like elastic body 22 is illustrated in a state in which the width direction is directed to the axial direction of the body-side annular member 2. In addition, the axial direction of the body outer side annular member 2 is defined as the direction in which the center line (one-dot chain line) in the body outer side annular member 2 of FIG. Moreover, about the strip | belt-shaped elastic body 22, the width direction and thickness direction are each defined as the direction along the long side and short side in the rectangular cross section of the strip | belt-shaped elastic body 22 to a twist direction, respectively. Synonymous. Supplementally, the cross section of the belt-like elastic body 22 in the twisting direction is configured to bend according to the torsional force. However, when the torsional force does not act on the belt-like elastic body 22, It is formed to have a rectangular cross section. The long side direction and the short side direction are defined with respect to the neutral rectangular cross section.

  In the contracted state of the belt-shaped elastic body 22 in the circumferential direction, that is, in the contracted and closed state of the outer annular member 2 in the radial direction, the width direction of the band-shaped elastic body 22 is the axial direction of the retractor 1 as shown in FIG. The contact of the square block 21 will be described assuming that (the vertical direction in FIG. 4).

  In Fig.4 (a), the strip | belt-shaped elastic body 22 is the state extended in the circumferential direction, and the contact side surface 23 is non-contact with the contact side side surface 23 of the square block 21 adjacent to the circumferential direction (FIG.4 (a)). In FIG. 3, the white outline indicates a non-contact state.) The rectangular cross section of the belt-shaped elastic body 22 is fitted inside the contact side surface 23 of the rectangular block 21, and the long side dimension of the rectangular cross section is equal to the side dimension of the contact side surface 23, and The dimension of the short side is set to be sufficiently smaller than the dimension of the side of the contact side surface 23.

  On the other hand, in FIG. 4B, the belt-like elastic body 22 is in a contracted state in the circumferential direction, and the contact side surfaces 23 facing each other in the circumferential direction of the body-side annular member 2 are in FIG. They are in contact with each other in the contact area indicated by hatching with crossed lines. Further, this contact region is a range that reaches the predetermined position on the outer peripheral side from the end on the inner peripheral side of the contact side surface 23 beyond the belt-like elastic body 22 to the outer peripheral side.

  In FIG. 4B, the contact region reaches a position beyond the belt-like elastic body 22 toward the outer peripheral side. For this purpose, the square block 21 is not a perfect rigid body in the circumferential direction, but a belt-like shape. At the time of contact with the adjacent rectangular block 21 in the circumferential direction due to the reduction of the elastic body 22, at least a part in the circumferential direction has an elastically deformable portion in which the inner circumference side appropriately shrinks in the circumferential direction from the outer circumference side. .

  In the rectangular block 21 of FIGS. 2 and 3, each contact side surface 23 is formed from one plane perpendicular to the circumferential side surface 24. On the other hand, in order to increase the contact area between the contact side surfaces 23 of the rectangular blocks 21 adjacent to each other in the circumferential direction when the belt-like elastic body 22 is reduced, each contact side surface 23 is formed from two plane portions. be able to.

  That is, when the body outer annular member 2 is contracted and closed, the rectangular blocks 21 adjacent to each other in the circumferential direction are viewed from the axial direction of the body outer annular member 2 (FIG. 3 shows the body outer annular member 2 from this direction). The contact area between the contact-side side surfaces 23 increases when the fan-shaped portion is squeezed toward the center of the outer annular member 2 than when it is rectangular. Therefore, the contact-side side surface 23 is not formed as one plane, but is formed in separate planes on the half portions on both sides of the belt-like elastic body 22, and when the body-side annular member 2 is contracted, 2 of each square block 21 is formed. The rectangular block 21 is formed so that the planes of the inner peripheral side half portions of the two contact side surfaces 23 have an inclination angle that is squeezed toward the center of the body outer ring member 2 when viewed from the axial direction of the body outer ring member 2. A fan-shaped contour is formed when viewed from the axial direction of the outer annular member 2.

  With reference to FIG. 5, a process when the retractor 1 is set on the abdominal wall 10 of the subject will be described. After forming the wound 15 on the abdominal wall 10 of the subject, the surgeon stands the body inner annular member 3 vertically with respect to the surface 11 of the abdominal wall 10 as shown in FIG. Push into body cavity 14 through wound 15.

  When the insertion of the body inner annular member 3 into the body cavity 14 is completed, the body outer annular member 2 is then lifted up a little as shown in FIG. 10 along the back surface 12. As a result, the body outer annular member 2 and the body inner annular member 3 are both substantially parallel to the abdominal wall 10 and return to a circular shape by elastic restoring force.

  Next, the surgeon pulls the body outer ring member 2 with two hands at both ends of a predetermined diameter radially outward, and then widens the interval between the square blocks 21. Thereby, the strip | belt-shaped elastic body 22 expand | extends, the square block 21 leaves | separates in the circumferential direction, and the contact side surface 23 of the square blocks 21 adjacent to each other in the circumferential direction is not in contact. Therefore, the frictional force resulting from the mutual contact of the contact side surfaces 23 does not occur, and the torsional rigidity or torsional resistance force of the outer body annular member 2 is small.

  In this way, the surgeon makes the torsional rigidity or torsional resistance of the outer annular member 2 small, and then the inner and outer peripheries are repeatedly reversed around the annular axis of the outer annular member 2 at the two locations. Thus, twisting is performed in opposite torsional directions. As a result, the flexible sleeve 4 is wound around the body outer annular member 2 at the end on the body outer annular member 2 side, the axial length of the flexible sleeve 4 is reduced, and the body outer annular member 2 is reduced. And the length between the body inner annular member 3 is reduced.

  When the axial length of the flexible sleeve 4 is approximately equal to the thickness of the abdominal wall 10, the surgeon finishes adjusting the length of the flexible sleeve 4, and as shown in FIG. The body outer annular member 2 is placed (set) on the surface 11 of the abdominal wall 10 of the subject. The body outer ring member 2 and the body inner ring member 3 are in close contact with the front surface 11 and the back surface 12 of the abdominal wall 10, respectively, and the flexible sleeve 4 expands in the radial direction, so that the wound 15 is expanded in a circular shape.

  In the set state of the retractor 1 to the abdominal wall 10, the body-side annular member 2 comes into contact with the contact-side side surfaces 23 of the rectangular blocks 21 adjacent to each other in the circumferential direction due to the reduction of the belt-like elastic body 22. Therefore, the mutual frictional force due to this contact functions as an increase in the torsional rigidity or torsional resistance of the outer annular member 2. Such an increase in torsional rigidity or torsional resistance leads to prevention of unintentional unwinding of the flexible sleeve 4 from the outer annular member 2 when the outer annular member 2 is set on the surface 11 of the abdominal wall 10. .

  When the retractor 1 is set on the abdominal wall 10, the square block 21 is such that one of the four peripheral side surfaces 24 faces the surface 11 of the abdominal wall 10. In this case, there are two cases where the width direction of the belt-like elastic body 22 is perpendicular to the abdominal wall 10 and parallel. However, due to the snap action of the band-shaped elastic body 22 in the torsional direction, the band-shaped elastic body 22 usually has its width direction oriented not in the radial direction of the body-side annular member 2 but in the axial direction of the body-side annular member 2. Stable in state. Therefore, the body-side annular member 2 is placed on the surface 11 of the abdominal wall 10 at a position where the width direction of the belt-like elastic body 22 is aligned in the direction perpendicular to the abdominal wall 10.

  This snap action will be described. In the contracted state in which the belt-like elastic body 22 has both ends in the width direction on the inner and outer peripheral sides, the inner peripheral portion is sufficiently reduced, whereas the outer peripheral portion is still pulled in the circumferential direction. For this reason, a predetermined difference occurs between the inner peripheral side and the outer peripheral side with respect to the circumferential reduction force. In this state, when the body outer annular member 2 is twisted even a little, the circumferentially reducing force is torsionally rotated in the torsional direction in which the circumferential reduction force is balanced between the inner peripheral side and the outer peripheral side, becoming an unstable state in the torsional direction. Yes.

  On the other hand, in the contracted state in which the belt-shaped elastic body 22 faces both sides in the width direction in the axial direction of the retractor 1, the circumferential contraction force is substantially balanced between the inner peripheral side and the outer peripheral side. For this reason, even if the body outer side annular member 2 is twisted a little, it will be in the stable state of the twist direction which returns to an equilibrium state.

  The body-side annular member 2 alternates between a stable state and an unstable state every time it is turned 90 ° in the twisting direction. The torsional force from the stable state to the unstable state is positive, while the torsional force from the unstable state to the stable state is negative. As a result, a snap action can be generated in the screw driving of the outer annular member 2.

  When the surgeon releases the twisting direction operating force to the outer annular member 2, the width direction of the belt-like elastic body 22 is usually stable in the twisting direction of the outer annular member 2 as shown in FIGS. 3 and 4. This is the axial direction of the outer annular member 2 that is in the state. Such a stable state in the torsional direction prevents the outer annular member 2 from being twisted into an unstable torsional direction in which the width direction of the belt-shaped elastic body 22 is the radial direction of the outer annular member 2.

  Such alternate repetition of the torsional stable state and unstable state of the belt-like elastic body 22 every 90 ° in the torsional direction functions as an increase in the torsional rigidity of the outer annular member 2. The increase in the torsional rigidity of the outer annular member 2 leads to prevention of unintentional unwinding of the flexible sleeve 4 from the outer annular member 2 when the outer annular member 2 is set on the surface 11 of the abdominal wall 10. .

  The polygonal cross section of the square block 21 in the torsional direction requires that the square block 21 be raised from the surface 11 with the chamfered portion 25 serving as a vertex as a fulcrum in order for the square block 21 to reverse the inner and outer circumferences on the surface 11 of the abdominal wall 10. Therefore, the inversion of the inner and outer periphery of the square block 21 is suppressed, and as a result, the torsional rigidity of the outer annular member 2 is increased.

  The body outer annular member 31 will be described with reference to FIG. The body outer ring member 31 has a structure in which an elastic film 32 is added to the body outer ring member 2 of FIGS. 6A is a view of the contracted outer body annular member 31 in the axial direction, FIG. 6B is a view of the contracted body outer ring member 31 viewed from the side, and FIG. 6C is the exterior of the body. It is the figure which looked at a part of body outside annular member 31 from the side in the state where the annular member 31 was extended and developed.

  2, the space between the contact-side side surfaces 23 of the rectangular blocks 21 adjacent to each other in the circumferential direction is opened to the periphery when the radial member 2 is expanded in the radial direction. There is a high possibility that the portion of the flexible sleeve 4 that has entered the open space is caught between the contact-side side surfaces 23 when the body-side annular member 2 is contracted. The sandwiching of the flexible sleeve 4 between the contact side surfaces 23 leads to a decrease in the contact force between the contact side surfaces 23.

  Therefore, in the body-side annular member 31, the elastic film 32 has side edges of the circumferential side surface 24 of the rectangular block 21 adjacent in the circumferential direction on both sides in the thickness direction of the belt-shaped elastic body 22 (short-side direction of the rectangular cross section). It is stretched between.

  Since the elastic film 32 does not exist on both sides in the width direction of the belt-like elastic body 22, when the body-side annular member 31 is viewed from the direction in which the thickness of the belt-like elastic body 22 can be seen (FIG. 6 (c) is from this direction. The outer annular member 31 is viewed.), And a gap is formed between the belt-like elastic body 22 and the outer annular member 31. This gap contributes to maintaining the ease of twisting in the range of the belt-like elastic body 22 in the circumferential direction of the body-side annular member 31.

  Since the elastic film 32 must follow the radial expansion and contraction of the outer annular member 31, the elastic film 32 is elastically deformed in the circumferential direction and the radial direction of the outer annular member 31, similarly to the belt-like elastic body 22. It is supposed to be.

  The width and thickness of the elastic film 32 are approximately equal to the width and thickness of the rectangular cross section of the belt-shaped elastic body 22 (see FIG. 4A), respectively, and the circumferential length of the elastic film 32 as viewed in the axial direction of the body-side annular member 31. The circumferential length of the outer body annular member 31 is substantially equal. In each elastic film 32, the side facing the belt-like elastic body 22 is referred to as an inner surface side, and the opposite side is referred to as an outer surface side. The elastic film 32 is formed so that the inner surface side is convex and the outer surface side is concave. As a result, when the outer annular member 31 is radially contracted, the elastic film 32 on the inner peripheral side of the outer annular member 31 is displaced toward the inner surface side and is folded between the rectangular blocks 21. . In addition, the elastic film 32 on the outer peripheral side of the outer annular member 31 is sufficiently widened to partition the rectangular blocks 21 from the outer peripheral side.

  In the body outer ring member 31, when the belt-like elastic body 22 is contracted, the elastic film 32 on the inner peripheral side is folded between the contact side surfaces 23 in the circumferential direction, so that the contact side surfaces 23 adjacent in the circumferential direction are in direct contact with each other. Without contact, the contact is made through the elastic film 32 on the inner peripheral side. Therefore, in the outer ring member 31, the contact surface between the contact side surface 23 and the elastic film 32 contacts with a predetermined pressing force in the circumferential direction, so that the torsional resistance force of the outer ring member 31 is between the contact surfaces. Arise. Due to this torsional resistance, as in the case of the outer annular member 2, the circumferential flexible sleeve 4 is unwound from the outer annular member 2 when the outer annular member 31 is set on the surface 11 of the abdominal wall 10. Can be suppressed.

  When the belt-like elastic body 22 is pulled and the body-side annular member 31 is expanded radially in order to wind or unwind the flexible sleeve 4 around the body-side annular member 31, the flexible sleeve 4 is In the short side direction of the rectangular cross section of the belt-like elastic body 22, the outer surface of the elastic film 32. In the long side direction of the rectangular cross section of the belt-like elastic body 22, the short side of the belt-like elastic body 22 and the elastic films 32 on both sides thereof. These side surfaces prevent entry into the gap between the contact side surfaces 23 in the circumferential direction. As a result, when the surgeon releases the operating force on the outer annular member 31 and the outer annular member 31 becomes free, the flexible sleeve 4 is sandwiched between the belt-like elastic bodies 22 in the circumferential direction. Is prevented.

  Although the present invention has been described with respect to the embodiments, the present invention is not limited thereto, and various modifications can be made within the scope of the invention.

  For example, in the embodiment, the flexible sleeve 4 is continuously fixed along the circumference of the outer annular member 2 and the inner annular member 3 continuously in the circumferential direction over the entire periphery of the opening. Is guaranteed, the fixed points may be discrete in the circumferential direction.

  The belt-like elastic body 22 has been described as having a rectangular cross section in the torsional direction, but may be a circle, triangle, or other polygonal shape.

  As a method for manufacturing the outer annular member 2 in which the square blocks 21 and the belt-like elastic bodies 22 are connected to each other in an alternating arrangement in the circumferential direction, the square blocks 21 and the belt-like elastic bodies 22 are individually prepared, and the square blocks There is a method of alternately connecting 21 and the belt-like elastic body 22 in series. In addition, an elastic band having a predetermined length is prepared, and the rectangular block 21 is divided into two equal parts, and the two equal parts of the square block 21 are fixed to the elastic band at predetermined intervals from each side of the elastic band. There is also a method in which the block 21 is manufactured and finally the ends of the elastic band are connected to each other.

  Instead of the belt-like elastic body 22, an annular coil spring can be adopted. In this case, each square block 21 is inserted through one coil spring at the center thereof, but can be moved along the center line of the coil spring without being fixed at each position of the coil spring.

  The square block 21 as the block portion has a substantially square or substantially rectangular cross section in the torsional direction of the outer body annular member 2, but may be a polygonal cross section. Further, in the polygonal cross section, it is assumed that the corner portion may be processed with R or the like like the chamfered portion 25 of the square block 21.

  In order to increase the contact force as torsional resistance when the square blocks 21 adjacent to each other in the circumferential direction contact each other on the contact side surface 23, fine irregularities and grooves that increase the friction on the contact side surface 23 are formed. can do. Alternatively, meshing teeth that engage with each other in the circumferential direction and prevent relative twisting in the torsional direction can be formed on the contact side surfaces 23 of the square blocks 21 adjacent to each other in the circumferential direction.

  The fine irregularities, grooves, and meshing teeth that increase the friction are folded on the contact surface between the contact side surface 23 and the inner surface of the elastic film 32 in the outer annular member 31 of FIG. It can also be formed on the outer surface portion of the elastic film 32 in contact with each other.

DESCRIPTION OF SYMBOLS 1 ... Retractor, 2 ... Body outside annular member, 3 ... Body inside annular member, 4 ... Flexible sleeve, 21 ... Square block (block part), 22 ... A belt-like elastic body (elastic elastic part), 31 ... an outer ring member, 32 ... an elastic film (blocking member).

Claims (5)

A cylindrical flexible sleeve opening at both ends;
A body inner annular member to which a peripheral edge of the one end side opening is fixed so as to hold one end side of the flexible sleeve in an open state;
The periphery of the opening on the other end is fixed so as to hold the other end of the flexible sleeve in an open state, and the flexible sleeve is wound in the twisting direction by repeatedly reversing the inner and outer periphery by twisting. A body outer annular member that can be rotated and unwound,
The outer annular member has block portions and elastic stretchable portions connected in an alternating arrangement in the circumferential direction,
The retractor according to claim 1, wherein the elastic expansion / contraction part separates the block part in the circumferential direction when extended and contacts the block part in the circumferential direction when contracted. The retractor of claim 1.
The said block part is set to the magnitude | size and shape in which the contact force which produces the torsional rigidity more than predetermined value between the said block parts at the time of mutual contact in the circumferential direction is obtained to a contact part. vessel. The retractor according to claim 1 or 2,
The retractor according to claim 1, wherein the block portion has a polygonal cross section when viewed in the circumferential direction of the outer annular member. The retractor according to any one of claims 1 to 3,
The block part and the elastic elastic part are both rectangular when viewed in the circumferential direction of the outer annular member,
The elastic expansion / contraction part is formed in a belt shape extending in the circumferential direction of the body-side annular member, and the long side of the rectangular cross section of the elastic expansion / contraction part is the length between one opposite side of the rectangular cross section of the block part. And the short side of the rectangular cross section of the elastic expansion / contraction part is shorter than the length between the opposite sides of the rectangular cross section of the block part. The retractor according to any one of claims 1 to 4,
The retractor according to claim 1, wherein the outer annular member has a blocking member between the block portions to prevent the flexible sleeve from entering between the block portions.

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