JP2003210474A - Trocar - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new trocar that can be positively changed over to a lock state and a lock release state while positively shielding a puncture part. <P>SOLUTION: A protective shield part 40 surrounding the outer peripheral side of a puncture body and movable between the tip side and the base end side to a handle part 20 is provided with a cam projecting part 40b. A safe locking part 50 is provided with a cam drum 52 formed with a cam groove part 53, and an operating part 56c for rotationally operating the cam drum 52. A lock state and a lock release state are changed over by changing the position of the cam projecting part 40b in the cam groove part 53 according to the rotation of the cam drum 52. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trocar used in endoscopic surgery, and more particularly to a trocar provided with a safety lock mechanism for shielding a sharp puncture portion at its tip.

[0002]

2. Description of the Related Art Endoscopic surgery is a revolutionary method of surgical operation that is becoming widespread, and the method is to open a hole in the body wall at several places or several centimeters and insert the endoscope. After obtaining the field of view, insert forceps or a scalpel (female) through the other hole, and work while looking at the monitor screen of the endoscope. A trocar is used to form a hole for inserting an endoscope instrument such as the endoscope, forceps, and scalpel (female).

In general, this type of trocar mainly includes an obturator assembly and a cannula assembly. The obturator assembly has a sharp puncture portion at its tip, and punctures by pressing the puncture portion against the skin. The cannula assembly is inserted into the hole formed by the puncture portion. The obturator assembly is then withdrawn, leaving only the cannula assembly as a passageway for communication between the body and the body, and the endoscopic instrument is inserted through the cannula assembly and into the body.

By the way, since the puncture portion is very sharp, it is protected in the shield by the safety lock mechanism when not in use, and when the lock is released during use, the puncture portion is pierced from the shield. The part can be projected. Then, after being pressed against the skin with a large load and penetrating the skin, it is necessary to be protected again in the shield so as not to damage other organs, and a safety lock mechanism for that purpose is provided. As such a safety lock mechanism, for example, Japanese Patent Publication No. 56907/1993,
The thing described in Unexamined-Japanese-Patent No. 7-47077 is known. Japanese Examined Patent Publication (Kokoku) No. 5-56907 discloses a structure in which the obturator assembly is automatically unlocked by applying pressure in the distal direction, and after the puncture, the shield is locked again. The publication discloses a configuration in which the lock is released by sliding the button in the distal direction, and the shield is locked again after the puncture.

[0005]

However, in all of the above-mentioned conventional configurations, the operation in the distal direction is used as the trigger for unlocking, and the operation direction is the same as the operation direction for puncturing the trocar. Therefore, there is a problem that the operations are not separated and it is difficult to understand. In addition, there is a problem in that operability is poor when the button is slid toward the tip side.

Therefore, a first object of the present invention is to provide a novel trocar provided with a safety lock mechanism capable of reliably switching between a locked state and an unlocked state and capable of reliably shielding the puncture portion. Is to provide. A second object of the present invention is to provide a novel trocar with good operability.

[0007]

In order to achieve the above-mentioned object, the present invention provides a handle portion, a puncture shaft extending from the handle portion to the tip side, and a puncture body provided at the tip of the puncture shaft. A protective shield part that surrounds the outer side of the puncture body and is movable between the distal end side and the proximal end side with respect to the handle part, and within the handle part, the protective shield part moves to the proximal end side. A safety lock part that switches between a locked state where it becomes impossible to shield the puncture body and a lock released state where the protection shield part can move to the base end side,
In the trocar having the above-mentioned, the protection shield part cannot rotate relative to the handle part, and the protection shield part is provided with either a cam protrusion part or a cam drum formed with a cam groove part. The lock portion includes either the other of the cam drum formed with the cam protruding portion or the cam groove portion, and the operating portion for rotating the other of the cam drum formed with the cam protruding portion or the cam groove portion. That is, the lock state and the unlocked state are switched by changing the position of the cam protruding portion in the cam groove portion according to the rotation of the other one of the cam protruding portion or the cam drum in which the cam groove portion is formed. Characterize.

If either the cam protrusion or the cam drum having the cam groove is rotated relative to the handle, the protective shield that cannot rotate relative to the handle cannot rotate. In addition, relative movement occurs between the cam groove portion of the cam drum and the cam protruding portion. Then, the position of the cam protrusion in the cam groove changes. In this way, at one position, the protective shield part cannot move to the base end side, and the protective shield part can be locked, and at another position, the protective shield part can move to the base end side and the protective shield part becomes Can be unlocked. The cooperative operation of the cam protrusion and the cam groove makes it possible to reliably switch between the locked state and the unlocked state.

The operating portion rotates with respect to the handle portion, and either the cam protrusion or the cam drum having the cam groove can be rotated according to the rotation of the operating portion. As a result, the operation of the operation unit can be performed in a rotation direction different from the direction used for the trocar puncture work, the operations can be clearly separated, and are easy to understand, and the operability is also good. Become.

Further, the operating portion and the other one of the cam drum having the cam projection or the cam groove are biased in the same rotational direction, and the operating portion rotates in the opposite direction to the biased direction. When the operation force is released, the other one of the cam protrusion and the cam drum having the cam groove is rotated in the same opposite direction. Thus, the operating portion can be rotated to the original position independently of either the cam protrusion or the cam drum in which the cam groove is formed. As a result, when the operating force of the operating portion is released, the operating portion returns to the original position independently of the other of the cam protruding portion or the cam drum having the cam groove portion by the biasing force, and the operating portion returns to the original position. Even if is operated again, the other of the cam protrusion or the cam drum having the cam groove formed on the other side cooperates with the cam protrusion of the protective shield portion independently of the operation portion, so that a malfunction occurs. There is no.

The protective shield portion is biased toward the distal end side, and when the protective shield portion is once moved to the base end side in the unlocked state, the cam projection portion is moved to the initial locked position of the cam groove portion. It can be configured to move.

[0012] Within the scope of the claims, the safety lock portion can optionally be composed of the cam drum and the operating portion. The cam drum and the operating section may be integrated or may be separate parts.

Within the scope of the claims, optionally, the safety lock portion is rotated integrally with the operating portion in addition to the cam drum and the operating portion, and the central axis of the rotating portion is provided with respect to the cam drum and the operating portion. Can be moved in the direction, and the cylinder is engaged with the cylinder arranged on the outer peripheral side of the cam drum, and the rotation of the cylinder can be transmitted to the cam drum. And a clutch portion that does not transmit rotation to the cam drum. In this case, the engagement of the cylinder with the clutch part can be switched to the disengagement by moving the cam protrusion, and the movement of the cam protrusion from the locked position to the unlocked position can be used. You can
Therefore, it is preferable to form a cam on the cylinder that engages with the cam protrusion. In addition, spring means for urging the cylinder in the engagement direction may be provided.

It is preferable that the cam drum, the operating portion, the cylinder and the clutch portion are all biased in the same rotational direction.

Further, it is preferable that the protective shield portion is always biased toward the base end side. Further, in the cam groove portion, the cam projection portion that prohibits the movement of the protection shield portion toward the base end side and the movement of the protection shield portion toward the base end side are permitted, but return to the first position. Is a prohibited second position, and a third position in which the protective shield part has moved from the second position to the base end side,
A fourth position, which is capable of making a transition from the third position and making a transition to the first position, may be provided.

It is also possible to provide an indicator showing the locked state and the unlocked state on either the other of the cam protruding portion or the cam drum formed with the cam groove portion.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The following embodiments do not limit the present invention. In the following description, the operator side is referred to as the base end side (or the upper end side), and the side away from the operator is referred to as the tip end side (or the lower end side).

FIG. 1 is an overall view of the trocar of the present invention. As shown in FIG. 2, the trocar 10 mainly includes an obturator assembly 12 and a cannula assembly 1.
4 and the obturator assembly 12 and the cannula assembly 14 are detachably connected.

3 and 4 are exploded perspective views of the obturator assembly 12. The obturator assembly 12 is roughly divided into a puncture / handle portion 16 and a shield / lock portion 18.

The puncture / handle portion 16 has a housing 20 composed of left and right housing members 20A and 20B, and a base end portion inserted into the housing 20 so that the housing 2
The puncture shaft 22 consisting of puncture shaft members 22A and 22B fixed to the top of the housing 20 through almost 0, a lid 24 (see FIG. 4) for covering the top of the housing 20, and a tip of the puncture shaft 22 And the puncture body 26.

Housing member 20A and housing member 2
The receiving portion 20a of the housing member 20A and the boss 20b of the housing member 20B are fitted into the housing 0B to form an integral housing 20, which constitutes a handle portion that the operator holds. In addition, by fitting the bosses 24a protruding from the inner surface of the lid 24 to the receiving portions 20c and 20d formed on the tops of the housing members 20A and 20B, respectively, the housing members 20A, 20B and the lid 24 are connected. The fitting is held more reliably. Buttons 28, 28 are swingably attached between the two ends of the housing members 20A, 20B. At the tip of each button 28, a claw piece 28a extending toward the cannula assembly 14 is formed, and by the elastic force of the button 28 itself having a U shape,
The claw piece 28a is locked to the cannula assembly 14.
In addition, the two buttons 28, 28 are pressed inward against their elastic force and the claw pieces 28a, 28a are tilted inward, whereby the locking is released, and the obturator assembly 12 and the cannula assembly 14 are released. And can be separated.

At the top of the housing member 20A, the base end of the puncture shaft member 22A is inserted into the central hole 20e formed on the central axis. The proximal end of the puncture shaft member 22A having the center hole 20e inserted therein is fixed to the housing 20 by an E ring 23. Puncture shaft member 2
2A, 22B and the puncture body 26 are integrally assembled by fitting the portions formed at their ends and having irregularities in the direction orthogonal to the central axis to each other. These are composed of separate parts for easy assembling, but they can be made into one piece or can be integrally processed by welding or the like. Since the movement in the direction orthogonal to the central axis is restricted by the protective shield section 40 described later, the integrity is always maintained.

Next, the shield of the obturator assembly 12
The lock portion 18 is roughly divided into a protective shield portion 40 and a safety lock portion 50.

The protective shield part 40 includes a shield member 40A and a shield member 40A as shown in FIGS.
A hollow tube composed of B and a bullet member 40C,
The puncture shaft 22 and the puncture body 26 are inserted inside thereof so as to be relatively movable along the central axis direction. The shield members 40A, 40B and the bullet member 40C are formed as separate parts to facilitate the assembling, but may be integrated. A groove corresponding to the thickness of the puncture body 26 is formed inside the bullet member 40C, and the puncture body 26 can slide in the groove. Bullet member 40
An opening 40a communicating with the groove is formed at the tip of C, and the tip of the puncture body 26 can pass through the opening 40a and project from the protective shield 40. The base end portion of the shield member 40A is inserted into the housing 20, and a cam protrusion 40b protruding in the radial direction as far as a T shape is formed at the end thereof, and the cam protrusion 40b is a cam groove portion described later. For use with 53. Both ends of the cam protrusion 40b are slidably fitted in vertical grooves 20f (FIG. 3) and 20g (FIG. 4) formed in the housing members 20A and 20B, whereby the housing 20 which is a handle portion. On the other hand, the protection shield part 40 is relatively movable along the central axis but is not relatively rotatable. The above-mentioned protective shield part 40 has the lid 24 on the base end side.
The compression spring 42 interposed between the puncture body 26 and the puncture body 26 constantly urges the puncture body 26 toward the tip side, and thus urges the tip of the puncture body 26 to be covered.

Next, the safety lock portion 50 includes a cam drum 52 composed of cam drum members 52A and 52B, a cylinder 54, an operating ring 56, a clutch ring 58, and
And housed in the housing 20 while being biased in the same rotational direction.

The cam drum 52 is arranged in the housing 20 so as to surround the base end portion of the protective shield portion 40, and includes cam drum members 52A and 52B. As shown in FIGS. 6 and 7, the cam drum members 52A, 52
B is composed of separate parts to facilitate the assembling, but it can be made into an integrated product and operates integrally. That is,
Recessed portion 52a formed at the base end of the cam drum member 52A
To the convex portion 5 formed at the tip of the cam drum member 52B.
2b is fitted and the cam drum members 52A and 52B are connected. On the side surface of the cam drum 52 connected to the cam drum members 52A and 52B, a pair of cam groove portions 5 that cooperates with the cam protruding portion 40b of the protection shield portion 40.
3 is formed. Therefore, the pair of cam groove portions 53 are inserted into both ends of the cam protrusion 40b of the protection shield portion 40. During assembly, cam drum members 52A and 52B
Before the and are connected, the cam protrusion 40b of the protection shield part 40 is connected to the cam groove portion 5 formed in the cam drum member 52A.
3 and then the cam drum member 52B is connected to the cam drum member 52A, and as a result, the cam projection 40b of the protection shield 40 is inserted into the closed cam groove 53.
Restrain.

An indicator 52e is formed at the tip of the cam drum member 52A so as to project in the radial direction. The indicator 52e is provided on the housing member 20.
The indicator opening 20h (see FIG. 4) formed on the side surface of A and extending in the circumferential direction is slidably fitted to face the outside. In the indicator 52e, the protective shield part 40 is in a locked state (ON) depending on the position in the circumferential direction.
Or the unlocked state (OFF), preferably with a color different from that of the housing 20 so that the ON / OFF state of the lock can be clearly confirmed. Good to do.

A pair of projecting portions 52c, 5c projecting toward the base end side, that is, upward, is provided at the base end portion of the cam drum member 52B.
2c and a pair of flange portions 52d protruding in the outer diameter direction,
52d is formed.

A receiving portion (not shown) is formed on the inner peripheral surface of the cam drum member 52A, and one end 60a of the spring 60 is inserted into the receiving portion. The other end 60b of the spring 60 is hooked on the lower portion inside the housing member 20A, and the spring 60 constantly urges the cam drum 52 counterclockwise as viewed from the base end side.

The cam groove 53 has a locking lateral groove 53a.
A triangular main groove 53b, and a small triangular cam projection 53c formed in the middle of the bottom of the triangular main groove 53b,
Is provided. As schematically shown in FIG. 17, since the cam drum member 52A is biased counterclockwise by the spring 60 and the protective shield part 40 is biased toward the tip side, the cam of the protective shield part 40 is biased. Protrusion 4
0b passes through the cam groove portion 53 through the lock lateral groove 53a. The height of the cam projection 53c is the same as that of the puncture body 26.
Is smaller than the play in the central axis direction between the tip of the bullet and the opening 40a of the bullet member 40C.

The cylinder 54 is arranged so as to surround the outer peripheral side of the cam drum 52. As shown in FIG. 8 and FIG. 9, the cylinder 54 has a cam projection 40b of the protective shield 40 which is inserted through the cam groove 53.
Openings 54a, 54b larger than the cam groove portion 53 are formed on the side surface so that the same can be inserted. A cam surface 54f with which the cam projection 40b of the protective shield 40 engages is formed at the center of the bottom of the opening 54a on the tip side, as will be described later. The right side of 54f is higher than the left side. Further, at the base end of the cylinder 54, a pair of ratchet protrusions 54c, 54c protruding toward the base end, that is, upward,
A pair of flange portions 54g, 54g protruding in the outer diameter direction are formed. A vertical surface 54c1 parallel to the central axis direction and an inclined surface 54c2 having an angle with respect to the central axis direction are formed above the ratchet protrusions 54c and 54c. A pair of leaf spring portions 54d, 54d are formed on the tip end side of the cylinder 54.
The tip of 54d elastically contacts a step surface formed in the housing 20. The cylinder 54 is constantly urged toward the base end side by the spring force of the plate spring portions 54d and 54d. However, since the tip end of the cylinder 54 comes into contact with the flange portion 52d formed on the cam drum member 52B, further displacement of the cylinder 54 toward the base end side is restricted. Further, a hook portion 54e protruding in the outer diameter direction is formed on the side surface of the cylinder 54, and one end 62a of a spring 62 (see FIG. 3) is hooked on the hook portion 54e. The other end 62b of the spring 62 has the housing member 2
It is also hooked on a hook portion (not shown) formed inside 0A, and this spring 62 allows the cylinder 5
No. 4 is always urged counterclockwise when viewed from the base end side.

The operation ring 56 is arranged on the outer peripheral side of the base end portion of the cylinder 54. As shown in FIG. 10, the operation ring 56 has a ring-shaped main body 56a. Body 56
A pair of recesses 56b, 56b are formed on the inner peripheral surface of a, and the flanges 54g, 54g of the cylinder 54 are fitted into the recesses 56b, 56b. Therefore, the operation ring 56 and the cylinder 54 rotate integrally. However, the cylinder 54 can slide with respect to the operation ring 56 along the central axis direction. In addition, the operation ring 56 includes an operation portion 5 that extends from the main body 56a in the outer diameter direction.
6c is formed. The operating portion 56c is slidably fitted in an operating opening 20i (see FIG. 4) formed on the side surface of the housing member 20A and extending in the circumferential direction, and is exposed to the outside. The operation unit 56c is operated by an operator to switch from the locked state to the unlocked state according to the position in the circumferential direction.

The clutch ring 58 corresponds to the cam drum 5
2, the cylinder 54 and the operation ring 56 are arranged on the base end side, that is, on the upper side. As shown in FIG. 11, the clutch ring 5
8 has a ring-shaped main body 58a, and a pair of a small frame portion 58b having a small circumferential length and a large frame portion 58c having a large circumferential length are provided on the inner peripheral surface of the main body 58a. Are formed one by one. The ratchet projections 54c of the cylinder 54 are engaged with the small frame portions 58b, and the large frame portions 5b
The protruding portion 52c of the cam drum 52 is inserted into 8c. Further, a hook portion 58d is formed on the outer peripheral side of the main body 58a, and one end 64a of a spring 64 (see FIG. 3) is hooked on the hook portion 58d. The other end 64b of the spring 64 is similarly hooked on a hook portion (not shown) formed inside the housing member 20A, and the clutch 64 is always counterclockwise when viewed from the base end side by the spring 64. It is urged around. As will be described later, the clutch ring 58 transmits the clockwise rotation from the cylinder 54 side to the cam drum 52, while preventing the counterclockwise rotation from the cylinder 54 side from being transmitted by the cam drum 52. Is.

12 and 14 show the locked state and the unlocked state as viewed from the clutch ring 58 side, that is, the base end side when the safety lock portion 50 and the protective shield portion 40 configured as described above are assembled. 13 and 15 are side views of the locked state and the unlocked state, respectively, when the safety lock part 50 and the protective shield part 40 are assembled. Illustrations of the springs are omitted in each drawing.

The operation of the trocar constructed as above will be described. In the initial state, as described above, the cam protruding portion 40b of the protective shield portion 40 is located in the locking lateral groove 53a of the cam groove portion 53 of the cam drum 52 (FIGS. 16 (a) and 17 (a)). Position 1). Therefore, the protection shield part 40 cannot move along the central axis direction.
The puncture body 26 is housed in the bullet member 40C at the tip of the puncture body, and thus the tip of the sharp puncture body 26 is covered. This is the locked state.

Next, the lock is released to operate the trocar. Therefore, the operating portion 5 of the operating ring 56
6c is operated to the unlocked position, the housing 20
It is rotated clockwise from the end of the operation opening 20i to the opposite end (about 70 degrees). Then, the operation ring 56
The cylinder 54 rotates integrally with the rotation of the. As shown in FIG. 12, the ratchet projection 54c of the cylinder 54 presses the clutch ring 56 because its vertical surface 54c1 is in contact with the small frame portion 58b of the clutch ring 56. Since the protruding portion 52c of the cam drum 52 is in contact with the large frame portion 58c of the clutch ring 56, the cam drum 52 also rotates together.

When the cam drum 52 rotates, the cam protruding portion 40b of the protective shield portion 40, which is inserted through the cam groove portion 53, cannot rotate with respect to the housing 20, so that the locking lateral groove 53a is escaped. , Relatively moves to a position where the cam projection 53c is overcome (see FIG. 1).
6 (b) and FIG. 17 (b)). As described above, since the height of the cam protrusion 53c is smaller than the play in the central axis direction between the tip of the puncture body 26 and the opening 40a of the bullet member 40C, when the cam protrusion 40b gets over the cam protrusion 53c. In addition, the puncture body 26 does not jump out of the opening 40a of the bullet member 40C even if the protective shield part 40 retracts.

In this way, the cam projection 40b becomes the cam projection 5
As the cam drum 52 is urged counterclockwise by the spring 60 when the vehicle passes over 3c, the cam protrusion 53c abuts the cam protrusion 40b, and the second protrusion shown in FIGS. 16B and 17B. Maintain the state of position. with this,
The lock is released.

The cam projection 40b is provided on the cam surface 5 of the opening 54a of the cylinder 54 when it goes over the cam projection 53c.
When it goes along 4f and gets over the cam projection 53c, it pushes down the raised portion on the right side of the cam surface 54f of the opening 54a of the cylinder 54. Then, the cylinder 54
The leaf springs 54d and 54d are deformed and move toward the tip side with respect to the cam drum 52. As a result, the ratchet protrusion 54c of the cylinder 54, which is engaged in the small frame portion 58b of the clutch ring 58, is
It escapes from the small frame portion 58b and is released from the restraint of the clutch ring 58. Then, the urging force of the spring 62 causes the cylinder 54 to rotate counterclockwise and return to the initial position. Along with this, the operating ring 56 also rotates, and the operating portion 56c returns to the locked position. Also, the clutch ring 58 from which the ratchet protrusion 54c has escaped
Also rotates counterclockwise by the biasing force of the spring 64 and returns to the initial position. That is, except for the cam drum 52,
Cylinder 54, operating ring 56 and clutch ring 58
Will return to the original position, but since the protruding portion 52c of the cam drum 52 is inserted into the large frame portion 58c of the clutch ring 58, it must move relatively within the frame width of the large frame portion 58c. You can do it. Also,
The indicator 52e of the cam drum 52 moves to the OFF position of the indicator opening 20h, indicating that the lock is released. Even if the operating portion 56c is operated again in this state, the relationship between the cam drum 52, that is, the cam groove portion 53 and the cam protruding portion 40b does not change carelessly, and the state is stable.

In the unlocked state, the cam protruding portion 40b of the protective shield portion 40 can move to the base end side of the cam groove portion 53. Therefore, when the housing 20 is gripped and the tip is pressed against the skin, the protective shield portion 40
Can move to the proximal end side relative to the housing 20, so that the puncture shaft 22 and the puncture body 26 fixed to the housing 20 move toward the distal end side relative to the protective shield part 40. Then, the tip of the puncture body 26 protrudes from the opening 40a of the bullet member 40C of the protective shield part 40 and can puncture the body wall. Cam protrusion 4
0b moves toward the base end side from the cam projection 53c of the cam groove portion 53 (the third position in FIGS. 16C and 17C), the cam drum 52 is counterclockwise by the biasing force of the spring 60. Rotate around. Then, the cam protrusion 40b
Comes into contact with the wall surface on the left side when viewed from the side surface of the cam groove portion 53 (the fourth position in FIGS. 16D and 17D).

When the puncture body 26 is further punctured, the cam protrusion 40b moves to the base end side along the wall surface of the left wall of the cam groove 53. Then, when the perforation is completed and the protective shield portion 40 is released from the pressure from the body wall, the protective shield 40 moves toward the distal end side with respect to the housing 20 by the biasing force of the compression spring 42, and further, the cam drum 52. Is biased counterclockwise by the spring 60, so that the cam protrusion 4 of the protective shield 40 is
0b returns to the locking lateral groove 53a of the cam groove portion 53,
It is locked again (first position in FIGS. 16 (a) and 17 (a)). In this way, the tip of the puncture body 26 is reliably protected by the protective shield part 40.

(Other Embodiments) In the above embodiments, the safety lock portion 50 includes the cam drum members 52A and 52A.
Although the cam drum 52 is composed of B, the cylinder 54, the operation ring 56, and the clutch ring 58, the present invention is not limited to this, and a simpler configuration is possible. It is also possible to compose only. The cam drum and the operating ring are biased in the same rotational direction, and when the operating ring is operated so as to rotate in the direction opposite to the biased direction, the operating ring engages with the cam drum and the cam drum moves in the same opposite direction. Rotate to. Then, by the procedure shown in FIG. 17, the cam groove portion of the cam drum and the cam protruding portion 40b of the protection shield portion 40 are formed.
Is made for cooperation with. On the other hand, when the operating force is released, the operating ring is rotated independently of the cam drum to return to its original position by its urging force. In this way, it is possible to configure with a small number of parts, and the operation can be simplified.

Alternatively, as a simpler structure, the operation portion may be integrally formed on the cam drum, so that the safety lock portion may be composed only of the cam drum having the operation portion. Energize the cam drum in a certain rotation direction,
When the operating portion is operated so as to rotate in the direction opposite to the biased direction, the cam drum rotates and the cam groove portion of the cam drum and the cam protruding portion 40b of the protective shield portion 40 cooperate with each other by the procedure shown in FIG. You can do it. In this way, it is possible to configure with a smaller number of parts, and the operation can be further simplified.

In each of the above-mentioned embodiments, the protective shield portion is provided with the cam protrusion and the safety lock portion is provided with the cam drum. However, the present invention is not limited to this, and the protective shield portion is provided with the cam drum and the safety lock portion is provided. It is also possible to provide a cam protruding portion to be inserted into the cam groove portion of this cam drum.

[0045]

As described above, according to the present invention, it is possible to reliably switch between the locked state and the unlocked state by the cooperative operation of the cam protruding portion and the cam groove portion.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a trocar according to the present invention.

FIG. 2 is an overall perspective view of the trocar obturator assembly and cannula assembly of the present invention.

FIG. 3 is an exploded perspective view of an obturator assembly.

FIG. 4 is an exploded perspective view of an obturator assembly.

FIG. 5 is a perspective view of a protection shield part.

FIG. 6 is a perspective view of a cam drum.

FIG. 7 is an exploded perspective view of a cam drum.

FIG. 8 is a perspective view of a cylinder.

FIG. 9 is a perspective view of a cylinder.

FIG. 10 is a perspective view of an operation ring.

FIG. 11 is a perspective view of a clutch ring.

FIG. 12 is a plan view of the safety lock unit and the protective shield unit in a locked state viewed from the base end side.

FIG. 13 is a side view of the safety lock unit and the protection shield unit in a locked state.

FIG. 14 is a plan view of an unlocked state as seen from the proximal end side of the safety lock portion and the protective shield portion.

FIG. 15 is a side view of the safety lock unit and the protective shield unit in the unlocked state.

FIG. 16 is a diagram illustrating a cooperative operation of a cam drum and a protection shield part.

FIG. 17 is a development view showing the cooperative operation of the cam groove portion of the cam drum and the cam protruding portion of the protection shield portion.

[Explanation of symbols]

10 Trocar 20 Housing (handle part) 22 Puncture shaft 26 puncture body 40 Protective shield part 50 Safety lock part 40b cam protrusion 52 Cam Drum 53 Cam groove 56c operation part

Claims (4)

[Claims] 1. A handle portion, a puncture shaft extending from the handle portion to a distal end side, a puncture body provided at a distal end of the puncture shaft, and an outer peripheral side of the puncture body, and a distal end side with respect to the handle portion. The protective shield part that can be moved to and from the base end side, and the lock state in the handle part where the protective shield part cannot move to the base end side and shields the puncture body, and the protective shield part is the base end part. A trocar having a safety lock part for switching to an unlocked state so that the protection shield part cannot rotate relative to the handle part, and the cam projection part is provided on the protection shield part. Alternatively, either one of the cam drums in which the cam groove portion is formed is provided, and the safety lock portion is the other one of the cam drum in which the cam protrusion portion or the cam groove portion is formed, An operating portion for rotating either the other one of the cam protruding portion or the cam drum having the cam groove portion, and the cam depending on the rotation of the other one of the cam drum having the cam protruding portion or the cam groove portion. A trocar, wherein the locked state and the unlocked state are switched by changing the position of the protruding portion in the cam groove portion. 2. The operation section rotates with respect to the handle section, and either the cam protrusion or the cam drum having the cam groove section rotates in accordance with the rotation of the operation section. The trocar according to claim 1. 3. The operating portion and the other one of the cam protrusion and the cam drum in which the cam groove portion is formed are biased in the same rotational direction, and the operating portion rotates in a direction opposite to the biased direction. When the operation force is released, the other one of the cam protrusion and the cam drum having the cam groove is rotated in the same opposite direction. 3. The trocar according to claim 2, wherein the operating portion is rotated to the original position independently of the other of the cam protrusion and the cam drum having the cam groove formed therein. 4. The protection shield part is biased toward the tip side, and when the protection shield part is once moved to the base end side in the unlocked state, the cam projection part is positioned at the initial locked state of the cam groove part. Trocar according to any one of claims 1 to 3, characterized in that it moves to.