WO1999044517A1

WO1999044517A1 - Tubular surgical instrument

Info

Publication number: WO1999044517A1
Application number: PCT/EP1999/000543
Authority: WO
Inventors: Bernhard Kupferschmid; Pedro Morales; Dieter Weisshaupt
Original assignee: Aesculap Ag & Co. Kg
Priority date: 1998-03-04
Filing date: 1999-01-28
Publication date: 1999-09-10
Also published as: DE19809120C1

Abstract

The invention relates to a tubular surgical instrument, comprising a shaft in which a push and pull rod is mounted in a movable manner, a gripping part and handle for displacing the push and pull rod in relation to the shaft, and connecting means which detachably join the gripping part on the one hand and the shaft and push and pull rod on the other hand. The shaft is fixed in an axial direction in an inner sleeve of the gripping part by means of a locking body which can be radially displaced in said inner sleeve and becomes embedded in a recess in the shaft. The radially outward movement of the locking body is limited by a stop end which is situated on the inner sleeve and can be moved into a position in which the locking body can be moved radially outwards. One end of the push and pull rod engages a recess of a holding device. To simplify the structure of said surgical instrument the holding device can move with the action of a spring into an advanced release position and against the action of said spring into a retracted locked position. In addition, the push and pull rod can move forward in the shaft only so far that when it is immovably fixed in the inner sleeve it engages the holding device and moves said holding device into the retracted locked position.

Description

Surgical tubular shaft instrument

The invention relates to a surgical tubular shaft instrument with a shaft, with a push or pull rod slidably mounted therein, with a handle part and a handle for moving the push or. Tension rod relative to the shaft, and with connecting means which releasably connect the handle part on the one hand and the shaft and the push or pull rod on the other hand, the shaft in an inner sleeve of the handle part by means of an immersion in a recess of the shaft in the inner sleeve radially displaceable locking body is fixed in the axial direction, the radial outward movement of which is limited by a stop on the inner sleeve, which is displaceable in a position releasing the radial outward movement of the locking body, and wherein the push or pull rod has one end in a recess engages in the handle part by the handle movable holding device.

Such a tubular shaft instrument is described for example in DE 44 21 584 C2.

With this known tubular shaft instrument, it is possible to detach the shaft on the one hand and the push and pull rod on the other hand from the grip part, for which purpose it is necessary to withdraw an outer handle which, via a special driver, stops the holding device for the push and pull rod against the force a spring. This makes them relatively high Operating forces necessary to push back the handle.

It is an object of the invention to simplify the construction of such an instrument, in particular with a view to reducing the forces required to move the handle releasing the connection.

This object is achieved according to the invention in a tubular shaft instrument of the type described in the introduction in that the holding device is displaceable under the action of a spring in an advanced release position and against the action of the spring in a retracted locking position and in that the push and pull rod in the shaft is only so can be advanced far so that when it is fixed in the inner sleeve in the position of the holding device, it moves the holding device into the retracted locking position.

In this construction, the release of the push and pull rod does not take place by moving a stop by the handle, but the push and pull rod moves the holding device against the action of a spring into a retracted locking position, and out of it, even when inserted Locking position, the holding device is automatically pushed out as soon as the shaft is released from its axial fixing, and this is done by withdrawing a stop which releases the locking body of the shaft to the outside. Only very small forces are necessary for this displacement of the stop; the holding device of the push and pull rod is released by its own Spring of the holding device which has been tensioned by the push-in and pull rod in the locking position.

The holding device can be a collet, as described for example in DE 44 21 584 C2.

In preferred embodiments, however, it is provided that the holding device comprises an axially displaceable receiving sleeve for the push and pull rod and a locking member radially displaceable therein, which plunges into an indentation of the push and pull rod in the inserted state and thereby axially fixes it in the receiving sleeve and whose radial outward movement is unimpeded in the displaced position of the receiving sleeve, but is prevented in the retracted position by an external stop. The holding device is thus constructed similarly to the locking of the shaft.

It is expedient if the stop is formed by an outer, widening sleeve on the handle part, in which the receiving sleeve is slidably mounted.

In particular, the locking element can be a ball.

According to a further preferred embodiment it is provided that a stop dips into the inner sleeve under the action of a spring, which fixes the locking body in its radially outer position in the absence of a shaft and which in the inner position Sleeve inserted shaft is pushed back so far against the action of the spring that the locking body is radially inwardly displaceable, and that the stop is fixed by the locking body in its radially outer position in its position releasing the locking body.

Such a configuration leads to the fact that when the tubular shaft is pulled out of the inner sleeve, the stop inevitably dips into the latter and fixes the locking body in its radially outer position. This in turn defines the displaceable stop in the release position, so that when a shaft is reinserted into the instrument, it can be easily inserted into it without the stopper of the locking body having to be shifted into the release position beforehand. It is already fixed in this release position by the stop dipping into the sleeve and released again as soon as the shaft is inserted into the inner sleeve, because the shaft moves the stop again against the action of its spring out of the inner sleeve, so that the locking body can then be moved radially inward again into the position defining the shaft in the inner sleeve, in which the locking body is then fixed by the outer stop.

Such an embodiment is particularly advantageous in connection with the features of the tubular shaft instrument described above, but it would also be usable with differently constructed tubular shaft instruments. for example with a tubular shaft instrument, as described in DE 44 21 584.

In such an embodiment, it is expedient if the stop is formed by an outer sleeve surrounding the inner sleeve and displaceable thereon, which has an area with a smaller inner diameter and an area with a larger inner diameter at an axial distance.

It can further be provided that the outer sleeve is displaced by a spring into a locking position in which the region with a smaller inner diameter surrounds a radial channel of the inner sleeve receiving the locking body.

In a further preferred embodiment it can be provided that a spring-loaded ejector dips into the inner sleeve and pushes the shaft out of the inner sleeve when the locking body is pushed radially outward. This pushing out pushes the shaft out of its locking position in the grip part, the same also applies to the push and pull rod, which is moved together with the shaft. The user can then remove the released unit from the shaft and push and pull rod practically without force from the instrument.

It is particularly advantageous if the ejector is formed by the stop dipping into the inner sleeve, that is if a component is provided that fulfills a double function, namely that of the ejector. thrower and on the other hand that of the stop, which prevents the radial immersion of the locking body.

It is expedient for the ejector or the stop to be formed by a sleeve surrounding the push and pull rod, in particular if the sleeve is continuously in contact with the shaft when it is inserted. In this way, the part of the shaft, which has no recess for receiving the locking body, forms a stop for this locking body, which is thus held in its radially outer position until the recess of the shaft is opposite to it, only then does it take place Fixing the shaft in the inner sleeve and at the same time also releasing the outer stop in the locking position.

Such an ejector is also used advantageously in a construction as described above, but it could also be used in tubular shaft instruments of different construction, for example an instrument as shown in DE 44 21 584 C2.

The following description of preferred embodiments of the invention serves in conjunction with the drawing for a more detailed explanation. Show it:

Figure 1 is a side view of a tubular shaft instrument with a handle part arranged coaxially to the tubular shaft. Fig. 2 is an enlarged longitudinal sectional view of area A in Fig. 1 with the shaft locked and with the push and pull rod and locked

Fig. 3 is a view similar to FIG. 2 with the shaft released and the push and release rods released.

The tubular shaft instrument shown in the drawing comprises a tubular shaft 1, at one end of which two movable tools 2 are mounted, for example pliers jaws or cutting a cutting tool. In the interior of the shaft 1, a push and pull rod 3 is mounted coaxially to this, which pivots the tools 2 in opposite directions via a not-shown and known transmission when the push and pull rod 3 is moved relative to the shaft 1.

The shaft 1 and the push and pull rod 3 are held together in a sleeve-shaped, step-widening housing 4, which in turn is connected by a shaft 5 to a handle part 6 of the instrument. In the exemplary embodiment shown, this grip part 6 is arranged coaxially to the shaft 1 and has a lateral handle 7, which moves an actuating rod 9 in the interior of the housing 4 via suitable gear elements 8, which are only shown schematically in the drawing. This actuating rod 9 extends through the shaft 5 and ends in the interior of the housing 4 in a cup-shaped extension 10. The housing 4 is mounted on the shaft 5 by an annular shoulder 11 freely rotatable about the longitudinal direction of the shaft 5, this annular shoulder 11 engages in a circumferential groove 12 on the outside of the shaft 5, which is formed on the one hand by a step 13 on the circumference of the Shaft 5 and, on the other hand, an internally threaded sleeve 14 screwed onto the end of the shaft 5.

This internally threaded sleeve 14 surrounds the cup-shaped extension 10 of the actuating rod 9 and lies close to this extension 10, the inner wall of the internally threaded sleeve 14 expanding towards its free end and thus forming an annular space 15 between the internally threaded sleeve 14 and the cup-shaped extension 10.

In the cup-shaped extension 10, a spherical locking element 17 is freely movably mounted in a radial opening 16, which enters the cylindrical interior 18 of the extension 10 when the female threaded sleeve 14 lies tightly against the outside of the extension 10 (FIG. 2) and which one is complete emerges from the interior 18 when the internally threaded sleeve 14 lies opposite the opening 16 with the formation of the annular space 15 (FIG. 3).

On the extension 10, a surrounding the actuating rod 9 coil spring 19 is supported, the other end of which rests on the end face 20 of the shaft 5, so that the actuating rod 9 is moved under the action of this coil spring 19 into an advanced position, which by a in not the drawing Stop shown is defined so that the annular space 15 is opposite the opening 16 (Fig. 3). Against the action of the coil spring 19, the actuating rod 9 can be displaced such that the inner wall of the internally threaded sleeve 14 is opposite the opening 16 without forming an annular space 15, so that the locking element 17 is inserted into the interior 18.

The housing 4 goes over to its front side into a sleeve 21, which has a radial opening 22 in its side wall, in which a spherical locking body 23 is freely displaceable in the radial direction.

In this sleeve 21 a further sleeve 24 is immersed, which widens in a cup shape in the transition of the sleeve 21 into the rest of the housing 4; In this cup-shaped extension 25, a helical spring 26 is supported, the other end of which rests on the end face 27 of the internally threaded sleeve 14, so that the sleeve 24 is maximally pushed into the sleeve 21 by this helical spring 26. In this advanced position, it covers the opening 22 on the inside, so that the locking body 23 is thereby displaced radially outwards and projects outwards beyond the sleeve 21 (FIG. 3).

The sleeve 24 can be partially moved against the action of the coil spring 26 from the sleeve 21 to the rear end of the instrument, to the extent that this opens the opening 22 and the locking body 23 can enter the interior 28 of the sleeve 21 (Fig. 2). The displacement of the sleeve 24 against the helical spring 26 takes place through the shaft 1, which can be inserted into the sleeve 21 against the inner wall thereof and rests with its end edge 29 on the sleeve 24. The shaft 1 and the sleeve 24 form a continuous circumferential surface on their outside, so that when the shaft 1 is inserted, the spherical locking body 23 still remains in its radially outwardly displaced position, since it is also displaced radially outwards by the shaft 1 becomes.

Only when a recess 30 on the outside of the shaft 1, which can have the shape of a circumferential annular groove, but which can also consist of discrete recesses distributed over the circumference, is opposite the opening 22, can the locking body 23 radially inward into this recess 30 immerse, thereby the shaft 1 is fixed in the sleeve 21 in the axial direction.

On the outside of the housing 4 is a sleeve 31 surrounding this sleeve-shaped longitudinally displaceable, the displacement of which is limited on the one hand by a step 32 on the housing 4 and on the other hand by a stop 33 screwed onto the sleeve 21. The handle 31 is pushed against the stop 33 by a helical spring 34 which surrounds the housing 4 and is supported thereon and on the handle 31 and can be withdrawn against the force of the helical spring 34.

In the area of the opening 22 there is a sleeve-shaped one in an annular space 35 of the handle 31 surrounding the sleeve 21 Insert 36 is screwed in, which has a rear region 37, which lies tightly against the outside of the sleeve 21, and a front region 38, which surrounds the sleeve 21 at a distance. A bevelled ring step 39 is arranged in the transition area between the areas 37 and 38.

If the handle 31 is advanced under the action of the coil spring 34 against the stop 33, the rear region 37 is opposite the opening 22, so that the spherical locking body 23 cannot protrude outwards from the opening 22, so it then projects into the interior 28 into it (Fig. 2). When the handle 31 is retracted against the action of the coil spring 34, the front area 38 faces the opening 22 and then the locking body 23 can be pushed out of the interior 28 so that it protrudes radially outward from the opening 22 (FIG. 3).

The push and pull rod 3 is slidably mounted in the shaft 1 and thereby moves the tools 2 in the manner described. The movement of the push and pull rod 3 in the shaft 1 is limited in both directions by stops, these stops are not recognizable in the illustration , They can be located in the area of the gear elements, which converts the movement of the push and pull rod 3 into a pivoting movement of the tools 2.

To insert a structural unit which comprises the shaft 1 and the push and pull rod 3, the handle 31 is first pulled back against the coil spring 34, until the front region 38 of the insert 36 is opposite the opening 22. Since the locking body 23 can move radially outwards in this position, this position of the handle 31 of the sleeve 24 enables it to be fully immersed in the sleeve 21 under the action of the helical spring 26 and thereby to move the locking body 23 into the radially extended position ( Fig. 3). From this position, the locking body 23 cannot return into the interior 28, since it is prevented from doing so by the sleeve 24 inserted into the sleeve 21. This means that the handle 31 can not return to the advanced position under the action of the coil spring 34, since the extended locking body 23 rests on the ring step 39 and thus fixes the handle 31 in the retracted position.

Without inserting a shaft 1 and a push and pull rod 3, the unit comprising the grip part 6 and the housing 4 remains in this position. The actuating rod 9 is moved under the action of the coil spring 19 into the advanced position, in which the spherical locking element 17 can deflect outwards into the annular space 15 in the manner shown in FIG. 3. In this starting position, both the interior 28 are therefore the Sleeve 21 and the interior 18 of the actuating rod 9 free from the locking body 23 or the locking element 17. It is therefore easily possible to insert the assembly of shaft 1 and push and pull rod 3 from the front into the sleeve 21 until the Front edge 29 of the shaft 1 strikes the sleeve 24 and this when the shaft 1 is pushed in further against the kung the coil spring 26 gradually slides out of the sleeve 21. The push and pull rod 3 enters the interior 18 of the extension 10 and moves the actuating rod 9 against the action of the coil spring 19 into a position in which the inner threaded sleeve 14 lies tightly against the outside of the extension 10 and thereby the spherical locking element 17 slides radially inward into the interior 28, the locking element 17 enters a recess in the form of a circumferential groove 40 at the end of the push and pull rod 3 and thus locks the push and pull rod 3 on the one hand and the actuating rod 9 on the other in the axial direction.

As soon as the recess 30 of the shaft 1 is opposite the opening 22, the spherical locking body 23 is pushed radially inwards into this recess 30, namely by the movement of the handle 31, which is pushed forward under the action of the coil spring 34 and thereby with it beveled ring step 39 moves the locking body 23 radially inwards. As soon as this has taken place, the push and pull rod 3 is also axially fixed in the sleeve 21, so that the instrument is ready for operation.

To loosen the shaft 1 and the push and pull rod 3, the procedure is reversed; it suffices to pull the handle 31 back against the action of the coil spring 34.

The sleeve 24 lies against the shaft 1, which in turn is loaded by the helical spring 26 and tries to push the shaft 1 out of the sleeve 21. Once the

Claims

Handle 31 is withdrawn, this pushing force can move the shaft 1, and this thereby pushes the spherical locking body 23 out of the recess 30 and moves it radially outward, so that the shaft 1 is finally completely released in the axial direction. The shaft 1 can thereby be pulled out of the housing 4 and takes the push and pull rod 3 with it. By pulling out the push and pull rod, the actuating rod 9 with the extension 10 can also move in the extension direction under the action of the helical spring 19 until the spherical locking element 17 lies in the region of the annular space 15 and can exit radially to the outside. As a result, the push and pull rod 3 is released from the actuating rod 9 and can be pulled out of the instrument together with the shaft 1. The sleeve 24 holds the spherical locking body 23 in the extended position under the action of the coil spring 26, and this results in described way that the handle 31 remains in the retracted position in which the coil spring 34 is tensioned. Starting from this position, a unit consisting of shaft 1 and push and pull rod 3 can be used again in the manner described above. PATEN TAN SP RUCHE

1. Surgical tubular shaft instrument with one

Shaft, with a push and pull rod slidably mounted therein, with a handle part and a handle for displacing the push and pull rod relative to the shaft, and with connecting means which releasably connect the handle part on the one hand and the shaft and the push or pull rod on the other connect, wherein the shaft is fixed in an inner sleeve of the handle part by means of an immersing into a recess of the shaft, radially displaceable in the inner sleeve locking body, the radial outward movement of which is limited by a stop on the inner sleeve, which in one Radially outward movement of the locking body releasing position is displaceable, and wherein the push and pull rod engages with one end in a recess of a holding device displaceable in the handle part by the handle, characterized in that the holding device (10, 17) under the action of a spring (19 ) advanced into one Ene release position and against the action of the spring (19) is displaceable in a retracted locking position and that the push and pull rod (3) in the shaft (1) can only be advanced so far that they in the inner sleeve (21) firmly- placed position in the holding device (10, 17) engaging this moves into the retracted locking position.

2. Instrument according to claim 1, characterized in that the holding device comprises an axially displaceable receiving sleeve (10) for the push and pull rod (3) and a radially displaceable locking element (17) therein, which in the inserted state into a recess (40 ) the push and pull rod (3) is immersed and thereby axially fixes it in the receiving sleeve (10) and its radial outward movement is unimpeded in the advanced position of the receiving sleeve (10), but prevented in the retracted position by an external stop (14) becomes.

3. Instrument according to claim 2, characterized in that the stop is formed by an outer expanding sleeve (14) in which the receiving sleeve (10) is slidably mounted.

4. Instrument according to one of claims 2 or 3, characterized in that the locking element (17) is a ball.

Instrument according to one of the preceding claims, characterized in that, under the action of a spring (26), a stop (24) is immersed in the inner sleeve (21) and, in the absence of a shaft (1), the locking body (23) in its radially outer position and the shaft (1) inserted into the inner sleeve (21) is pushed back so far against the action of the spring (26) that the locking body (23) can be moved radially inwards, and that the stop (31) is fixed by the locking body (23) in its radially outer position in its position releasing the locking body (23).

6. Instrument according to claim 5, characterized in that the stop is formed by an inner sleeve (21) surrounding, on this displaceable outer sleeve (36) having an area (37) with a smaller inner diameter and an area ( 38) with a larger inner diameter.

Instrument according to Claim 6, characterized in that the outer sleeve (36) is displaced by a spring (34) into a locking position in which the region (37) with a smaller inner diameter has a radial channel (22) of the inner one which receives the locking body (23) Surrounds sleeve (21).

8. Instrument according to one of the preceding claims, characterized in that in the inner sleeve (21) a spring-loaded ejector (24) is immersed, the shaft (1) with the locking body (23) pushed radially outward from the inner sleeve (21) pushes out.

9. Instrument according to one of claims 5 to 7 and 8, characterized in that the ejector (24) is formed by the stop immersed in the inner sleeve (21).

10. Instrument according to one of claims 5 to 9, characterized in that the ejector or the stop are formed by a sleeve (24) surrounding the push and pull rod (3).

11. Instrument according to claim 10, characterized in that the sleeve (24) with the shaft (1) inserted continuously against it.