Actuating element and a pair of rocker units for an actuating element

An actuating element for actuating an instrument for performing minimally invasive interventions comprises a first handle half-shell and a second handle half-shell movable relative to each other and connected with each other at one end by a biasing mechanism; a tube arranged substantially centrally between the handle half-shells; a linkage mechanism arranged between the handle half-shells and the tube in order to transmit an actuating movement of the handle half-shells; a locking mechanism with a latching rocker arranged on the first handle half-shell and a locking rocker arranged on the second handle half-shell, wherein the two rockers enter into locking connection with each other through an opening provided therefor in the tube when the handle half-shells are moved together, and wherein the rockers are mounted around a pivot axis such that a swiveling or pivoting movement of the rockers lies within a plane defined by the handle half-shells.

TECHNICAL FIELD

The present invention relates to an actuating element as well as a pair of rocker units for an actuating element. In particular, the present invention relates to an actuating element for actuating an instrument for performing minimally invasive interventions which operatively interacts with a handle of the actuating element.

DESCRIPTION OF THE STATE OF THE ART

Actuating elements of this generic type are known. For example, US 2010/0004677 A1 discloses an actuating element comprising two handle half-shells that can be moved relative to each other, wherein the two handle half-shells are connected together at one end by a pretensioning or biasing mechanism and a tube is provided essentially in the middle between the two handle half-shells. In order to transmit an actuating movement of the handle half-shells, a linkage mechanism arranged between the handle half-shells and the tube is provided, the linkage mechanism being operatively connected to a rod running inside the tube. A similar configuration is also known from DE 102 93 222 B4. Further, U.S. Pat. No. 6,322,578 B1 discloses an actuating element comprising two handle half-shells that can be moved relative to each other. The known actuating element comprises two rocker units (catches) that are engaged upon actuation of the two handle half-shells and that can engage in a snappingly manner with each other. Each rocker unit is positioned in a respective handle half-shell such that upon closure of the handle half-shells they engage with complementary snap-in elements. Upon meeting of the snap-in elements, the two handle half-shells edge each other away around an axis generally parallel to the central tube axis, resulting in a swiveling movement of the handle half-shells transverse to the extension of the handle half-shells.

SUMMARY OF THE INVENTION

By contrast, according to the invention, an actuating element having the features as disclosed herein, are proposed.

Thus, the actuating element of the invention has a locking or snap-in mechanism that permits the actuating element to be locked when the handle half-shells are moved or squeezed together.

The locking mechanism comprises a latching or snap-in rocker arranged on a first handle half-shell and a locking rocker arranged on a second handle half-shell. When the handle half-shells are moved together, these two rockers enter into a locking connection with each other, through an opening in the tube provided for this purpose.

In one possible embodiment, provision is made for both rockers to be released from the locking connection by renewed actuation of the handle half-shells while these are in the together position.

In a further possible embodiment, the locking rocker is provided with a locking element and the latching rocker is provided with an undercut that can be brought into operative interaction with the locking element on the locking rocker.

The locking rocker and/or the latching rocker may each comprise a set screw or adjusting screw.

Further advantages and embodiments of the invention may be derived from the description and the attached drawing.

It is apparent that the aforementioned features, and those which are still to be mentioned below, may be used not only in the respectively stated combination, but also in other combinations or also by themselves, without departing from the scope of the present invention.

The invention is schematically illustrated in the drawing by an exemplary embodiment, and it will be described in detail below, with reference to the drawing.

DETAILED DESCRIPTION OF THE INVENTION

In the Figures, like elements and also elements having the same function are depicted with the same reference numerals.

FIG. 1shows a lateral partial sectional view of an actuating element10according to the invention for actuating an instrument that operatively interacts with the handle to perform minimally invasive surgical interventions. For the sake of simplifying the drawing and for greater clarity, only the actuating element itself is shown. The instrument used for minimally invasive interventions (which could be, for example, a clamp, forceps, scissors, or similar) is not illustrated. The connection between the instrument and the actuating element is made in a manner known to a person skilled in the art.

The actuating element10according to the invention comprises two handle portions12,14(called handle half-shells in the context of this application) which at one end (13,15) are connected with each other via a pretensioning or biasing mechanism. In the exemplary embodiment illustrated, the pretensioning mechanism comprises a shaft receptacle16with a gripping spring18. The handle half-shells may be formed integrally with the shaft receptacle or the biasing mechanism, respectively. This measure allows the manufacture and diminishes friction between the parts during use and also reduces mechanical wearout. The handle spring may, as appropriate, be formed integrally with the biasing mechanism.

A tube20is arranged substantially in the middle between the two handle half-shells12,14, said tube serving, in principle in a known manner, to transmit an actuating movement of the handle half-shells12,14. A linkage mechanism comprising a pair of articulated or linkage arms22is provided for transmitting this relative movement of the handle half-shells12,14, said articulated arms pivoting at one end respectively around a rivet24on one of the two handle half-shells12,14, and at the other end around a common pivoting point (or pivot axis), namely a pin26on a sliding element28guided in the tube20. For this purpose, an axial slot40is provided in the tube20.

Furthermore, the actuating element10according to the invention comprises a locking mechanism allowing the actuating element10to be arrested or locked when the handle half-shells12,14are squeezed together.

The snap-in or locking mechanism according to the invention comprises a latching rocker30arranged on a first handle half-shell12, as well as a locking rocker32arranged on a second handle half-shell14. The two rockers30,32enter into contact with each other through an opening38provided therefor in the tube20when the handle half-shells12,14are moved together. The two rockers30,32are designed in such a way that when they make contact they snappingly interlock with each other and thus prevent the pretensioned/biased handle half-shells12,14from moving apart again, such that the handle half-shells12,14are locked in this position.

When renewed pressure is applied to the handle half-shells12,14, the interlocking of the two rockers30,32is released such that the handle half-shells12,14can return to their starting position (shown in the Figure) under the action of the pretensioning.

The two rockers30,32may be designed, for example, in such a manner that one of the rockers30possesses an undercut which, when contact is made with the other rocker32, locks into a locking element provided thereon. The locking element can, for example, be a locking nose or snap-in nose.

As can be seen in the Figure, the two rockers30,32are suitably pivotably arranged on a respectively assigned handle half-shell. To this end, the two rockers30,32are pivotally arranged around a pivot axis54. As can be seen readily fromFIG. 1, the pivot axis54extends perpendicular to the drawing plane and thus substantially perpendicular to a longitudinal axis of the tube20. This results in a swiveling movement of the two rockers30,32in a plane that is spanned or generated by the two handle half-shells12,14.

For biasing the two rockers, pressure springs36are provided, respectively, as well as grub screws or threaded pins34for adjustment purposes. Each pressure spring36and grub screw34are arranged on opposite sides of the respective rocker pivot axis. This arrangement of the spring36outside of the rocker body, as it can be recognized from the depiction of the Figure very easily, allows for a more sensitive, i.e. more accurate adjustment of the rocker biasing and thus the rocker locking force. As a result, the fine tuning is enhanced. The use of a (inexpensive) pressure spring instead of a torsion spring supports this as the pressure spring exercises its force in a more constant manner than the torsion spring which thus allows for a more sensitive actuation.

The two rockers30,32according to the invention are illustrated in more detail inFIGS. 2 to 4.

FIG. 2Ashows a perspective view andFIG. 2Ba lateral plan view of a locking rocker32according to the invention. Correspondingly,FIG. 3Ashows a perspective view andFIG. 3Ba lateral plan view of a latching rocker30according to the invention.

Both rockers30,32each comprise a rocker body50or52having a central borehole through which passes the pivot axis54. The two rocker bodies50,52are substantially equal in design and particularly, each has a cam-shaped side56. The cam shape56facilitates the guidance of the rocker. On both sides of the cam curving, shoulders are formed. A first of these shoulders serves for engagement with the pressure spring36(cf.FIG. 1as well as the embodiments ofFIGS. 8 and 9). The opposing second shoulder serves, in the case of the embodiment ofFIG. 1, for engagement with the threaded pin34.

On the side opposite the cam-shaped side56each rocker50,52has a rocker neck58. The operative locking or snap element of the respective rocker is located at the end of each rocker neck58distal from the rocker.

On its rocker neck58the locking rocker32has a locking element62. The locking element62projects from the rocker neck58in a direction perpendicular to the axis of elongation A of the latter. The locking element62has an essentially oval shape, the main axis of which is inclined in relation to the axis of elongation. The angle of inclination can be for example 15° or 30° or 45° (measured clockwise in the depiction shown in the Figures). Other angles of inclination are also possible and are obvious to the person skilled in the art from his understanding of the present disclosure.

On its rocker neck58the latching rocker30has an element61having an undercut60. The element61projects from the rocker neck58in a direction perpendicular to the axis of elongation A. The element61has a substantially oval shape, the main axis of which is inclined in relation to the angle of elongation. The angle of inclination is selected to correlate with the angle of inclination of the locking element62of the locking rocker32and may, for example, be 15° or 30° or 45° (measured in the counter-clockwise direction in the depiction shown in the Figures).

The undercut60is provided on the oval shape of the element61such that it points in the direction of the rocker body56and is suitable for receiving a tip64of the oval locking element62, said tip pointing towards the rocker body56of the locking rocker32. When the opposed pivotally arranged rockers30,32approach each other, the said tip64of the locking element62comes into contact with the element61of the latching element30at an oval surface63distal from the rocker. The two rockers then push each other aside, so that they pivot around their respective pivot axes54, and the tip64slides along the surface63, then around an edge65of the undercut60, where it slips into the undercut60and engages therein. This interlocking position is illustrated, by way of example, inFIGS. 4A, 4B and 4C.

As already described above, the two rockers30,32are unlocked again by applying renewed pressure to the handle half-shells12,14so that, under the action of the pretensioning, the latter return to their starting position. The described swiveling of the two rockers in the plane spanned by the two handle half-shells, as can be seen easily in the Figures, has the advantage that no transverse movement of the rockers transverse to this plane occurs, as it is known from the prior art, thus avoiding according transverse forces which can disturbingly occur in the use of the actuation element of the prior art. The actuation element of the invention can thus be used in a more precise manner as no transverse pressure forces onto the handle are present any longer.

FIGS. 5A and 5Bshow embodiments of the two rockers30,32having projections74, each having a threaded borehole70,72, which are suitably designed to receive set screws (not shown). The threaded boreholes70,72run essentially parallel to the axis of elongation A of each rocker30,32and essentially perpendicular to the pivot axis of each rocker30,32. By means of the set screws it is possible to adjust the positioning of each rocker so that the tip64of the locking element62comes into contact with the element61of the latching rocker at the desired point and the two rockers are correctly interlocked so that the subsequent unlocking can take place immediately without any complications or snagging occurring. Similar rockers according to the invention are shown inFIGS. 10A to 10D, the rocker bodies50,52of which are designed more slender or narrow.

As can be seen easily from theFIGS. 3A, 3B, and5B the undercut60of the oval element61has a hole59or bore in its inner apex end. The hole59can—as in the shown embodiment—be substantially circular. The axis of the hole59extends substantially parallel to the pivot axis54. The hole59is made such that the end64of the engaging element62can be received therein. This hole59ensures that the two engaging elements61,62of the two rockers30,32do not disengage and move apart from each other in their locked position on their own, i.e. without renewed actuation of the rockers by means of the handle half-shells. Or in other words, the hole59minimizes the risk of unintentional disengaging of the rocker locking.

Analogously toFIG. 1,FIG. 6shows a lateral partial sectional view of an embodiment of an actuating element10′ according to the invention for actuating an instrument for performing minimally invasive interventions, said instrument being operatively interactive with the handle, and said actuating element having latching/locking rockers according toFIGS. 5A and 5B, with set screws76or78being provided in these rockers. The position of each rocker30,32, can be adjusted by how much the respective set screw76or78is screwed in.

Corresponding to the illustrations ofFIGS. 4A and 4B,FIGS. 7A and 7Bshow the interlocking position of the latching/locking rockers ofFIGS. 5A and 5B.

FIGS. 8 and 9show lateral partial sectional views of two further embodiments of actuating elements10″ or10′″ respectively for actuating an instrument for performing minimally invasive interventions, said instrument being in operative interaction with the handle. In these two embodiments the respective edges of the latching/locking rockers30,32opposite the biasing spring36rests on a shoulder80formed on the associated handle half-shell. The height of the shoulder80is matched to the shape of the rocker so that the desired alignment of each latching/locking rocker can be achieved. The rocker pair30,32used in the actuating element10″ ofFIG. 8is shown enlarged and in more detail inFIGS. 11A to 11D.