Surgical instrument

In a surgical instrument having at least one jaw part (6, 7) which is turnable around a pin (11), the jaw part (6, 7) is connected via a receiver (8, 9) with the pin (11), and the jaw part (6, 7) is detachably fastened with respect to the receiver (8, 9).

BACKGROUND OF THE INVENTION 
The present invention relates to a surgical instrument having at least one 
jaw part which is rotatable around an axis. 
Such surgical instruments are known and available on the market in many 
forms and embodiments. The corresponding jaw parts can serve for cutting, 
clamping, twisting-off, shearing, or the like. As a rule, they serve for 
performing given surgical interventions in man or animal. These 
instruments and their development have increased considerably in 
importance, as a result in particular of endoscopy. 
As example, reference is had here to a surgical instrument in accordance 
with P 43 32 497.5. 
In all of these instruments, the jaw parts are connected by a corresponding 
pull or push element with actuating members, for instance scissor arms. 
Upon actuation of the scissor arms, the jaw parts are opened and closed. 
In this connection, either both jaw parts can be movable or one jaw part 
can be stationary and the other jaw part moved. As soon as the jaw parts 
are worn out, the instrument is thrown away. 
There are also available on the market disposable instruments which are 
intended only for one operation and are then discarded. These disposable 
instruments are supplied in sterile packings, so that the disposing of the 
packing and of the instrument itself represents a considerable expense and 
is very problematic based on environmental considerations. 
The object of the present invention is to provide a surgical instrument 
which can be repeatedly reused and in which wear of the jaw parts does not 
constitute a problem. Furthermore, the possibility of sterilizing the 
instrument is to be facilitated. 
In order to achieve this object, the jaw part is connected via a receiver 
to the pin and the jaw part is detachably fastened with respect to the 
receiver. 
The basic concept of the present invention is that, particularly when worn, 
the jaw part can be detached from the receiver and be replaced by a new 
jaw part. In this way, the rest of the surgical instrument is fully 
retained and can be sterilized and repeatedly reused. Since the jaw part 
constitutes only an extremely slight portion of the manufacture work and 
cost of the surgical instrument, the present invention results in a 
substantial reduction of the cost, particularly in hospitals. 
As jaw part, a large number of embodiments can enter into consideration. It 
need merely be seen to it that the action of the jaw parts does not 
conflict with their detachable connection. In other words, the jaw part 
should not carry out any activity in which a strong pull is exerted on the 
jaw parts. In particular, there enters into consideration a development of 
the jaw parts as scissor blades, as well as jaw parts which are used today 
in biopsy forceps. 
The rest of the instrument is preferably so designed that it can easily be 
sterilized. For this, a surgical instrument in accordance with P 43 32 
497.5 offers itself. 
After detachment from the receiver, the jaw parts can either be thrown away 
and replaced by new ones, or they can be sterilized and/or reworked. A 
dull scissor blade can, for instance, be ground fresh and used again. 
Thus, the invention contributes considerably to reducing waste, in which 
connection, furthermore, only a slight amount of packing is necessary for 
the surgical instrument and the jaw parts. Of course, it is also possible 
to use on the same instrument different jaw parts with which different 
activities can be carried out. 
In a preferred embodiment, the jaw part has an extension with a guide slot 
which cooperates with a guide arm on a support plate of the receiver. This 
guide arm effects a targeted fastening of the jaw part to the receiver or 
a corresponding detent element. Therefore, there should also be provided 
on the receiver, in addition, a shoulder against which the jaw part 
strikes for the limiting of its motion. 
For the fastening by detent of the jaw part with respect to the receiver, 
it is preferred to provide in the region of the guide slot a detent hole 
which cooperates with a detent element. This detent element can be 
provided separately on the receiver, as a result of which, to be sure, the 
total length of the jaw is increased by about 3 mm. Since this is not 
always desirable, it is possible to use the above-mentioned pin also as 
detent element. In other words, the jaw part, guided by the guide arm in 
the guide slot, is pushed so far along the receiver that the guide slot 
strikes against the pin. By briefly pressing on the jaw part, the pin then 
slides into the detent hole, the guide slot opening somewhat for a short 
time. 
The receiver itself then has, on the other side of a hole for the pin, a 
nose extension which is articulated via a spread lever to a pull or push 
element. This pull or push element effects the rotation of the receiver, 
and thus of the jaw part, around the pin. 
In another embodiment, an elastic element which in position of use engages 
behind at least one undercut, an edge, or the like in or on the receiver 
is arranged on the jaw part and/or the receiver. 
This engagement by the elastic element means that a loosening of the jaw 
part from the receiver can only take place when the elastic element has 
been deflected in such a manner that it no longer engages behind the 
undercut, regardless of the nature thereof. This also means, however, that 
some expedient must be provided in order to effect a deflection of the 
elastic element. In this way, the reliability of the fastening of the jaw 
part on the receiver is assured and, in particular, the operator need no 
longer fear that a jaw part will become detached from the receiver during 
an operation in the human body and that can be removed from the body again 
only with great difficulty, for instance in the case of endoscopic 
interventions. 
For the reliable detachable fastening of the jaw part on the receiver, 
there are many possibilities. In this connection, it is immaterial whether 
the elastic element be present on the jaw part or on the receiver. The 
inventive concept always covers in all cases also the reverse arrangement. 
The following description of two embodiments is therefore merely 
illustrative. 
In the first embodiment, the jaw part has an extension with which there is 
associated an elastic tongue having a detent nose. From a purely 
manufacturing standpoint, this tongue can be suitably produced by 
stamping. In this connection, a suitable tongue can remain in a guide slit 
or else in a C-shaped slot. 
It is essential that the detent nose engage behind an undercut and at the 
same time become free from this undercut by deflection of the tongue. In 
order to facilitate this, the elastic tongue should have a tapered region 
which facilitates the deflection. 
As undercut, there can be used any projection or, in particular, also slot 
in the receiver, into which the detent nose snaps. In this case, it is 
desirable that, upon the insertion of the jaw part into the receiver, the 
jaw part be guided so that the detent nose also reaches the corresponding 
undercut. For this purpose, corresponding guide arms on the receiver 
serve, they cooperating, for instance, with guide slots. However, the same 
purpose is served also by a simple trough-shaped development which is 
formed at the end on the jaw part or a corresponding extension on the jaw 
part. This development seeks a congruent projection on the receiver. 
In another embodiment of the invention, the elastic element consists 
essentially of a detent strip which snaps behind an edge of the guide arm 
on the receiver. The guide arm preferably also has grooves on both sides 
into which arms which extend into the opening of a step-wise recess are 
guided. In this connection, on the one hand, the object is satisfied that 
the jaw part is guided upon the connecting with the receiver while, on the 
other hand, the advantage is also obtained that the jaw part cannot be 
loosened from the receiver even if it is bent-off laterally from the 
receiver. The arms in the grooves prevent the lateral breaking-out of the 
jaw part, so that a placing of this jaw part on a receiver from the 
outside is also possible. 
Particular attention is to be paid to the fact that the detachable 
fastening of the jaw part is effected in such a manner that the jaw part 
does not unintentionally loosen from the rest of the surgical instrument, 
for instance in the body of a patient. In other words, detent hole and pin 
must be so adapted to each other that while the pushing-on of the jaw part 
is possible, nevertheless a pulling-off of the jaw part can take place 
only under difficult conditions. Therefore, in a preferred embodiment of 
the invention, a mounting adapter is provided which permits better access 
to and better handling of the jaw parts. The jaw parts are so arranged in 
the mounting adapter that they cannot be shifted. At the same time, 
however, there is an opening in the mounting adapter into which the front 
part of the surgical instrument without the jaw parts can be introduced. 
Since in this case, the mounting adapter permits a greater pressure upon 
the clipping of the jaw parts onto the pin, the diameter of the detent 
hole can, for instance, be made somewhat smaller or else the thickness of 
the extension having the detent hole can be increased. This is so adapted 
that the pulling-off of the jaw parts with only two fingers is no longer 
possible. 
Of course, many possibilities which lie within the scope of the present 
invention are conceivable for a mounting adapter.

DETAILED DESCRIPTION 
FIG. 1 shows, for a surgical instrument in accordance with the invention, a 
front part of an outer tube 1 in which a connecting rod 2 (see FIG. 3) 
slides. Adjoining the outer tube 1 is a holder 3 which, as shown in FIG. 
2, forms a fork with two fork arms 4 and 5, between which the two jaw 
parts 6 and 7 are inserted. In the present embodiment, both jaw parts 6 
and 7 are developed as scissor blades. 
For the connecting of the jaw parts 6 and 7 to the holder 3, and for the 
turnable mounting, there are provided two receivers 8 and 9 which are 
connected to each other and to the fork arms 4 and 5 via a locking screw 
10. Adjoining the locking screw 10 there is a detent pin 13, shown in FIG. 
2, around which the receivers 8 and 9 and the jaw parts 6 and 7 are 
turnably arranged. 
The turnability of the receivers 8 and 9 around the detent pin 11 is 
effected by a movement of the connecting rod 2 in the direction x, in 
which connection the connecting rod 2 is connected with the receivers 8 
and 9 via spreading levers, of which only one spreading lever 12 is shown 
in FIG. 1. These spreading levers 12, on the one hand, form a pivot pin 13 
with the connecting rod 2 and, on the other hand, a pivot joint 14 with 
the receivers 9 and 8 respectively. Since the spreading levers 12 are 
arranged towards the outside, the receivers 8 and 9 are turned around the 
detent pin 11 upon a movement of the connecting rod 2 in the direction x, 
as a result of which an opening and closing of the jaw parts 6 and 7 takes 
place. A similar arrangement is described in P 43 32 497. 
Each jaw part 6 and 7 has, in accordance with FIGS. 4 and 6, a plate-shaped 
extension 15, in which a guide slot 16 is formed. Near an end surface 17, 
a detent hole 18 is arranged in the region of the guide slot 16. 
Each receiver 8 and 9 has a support plate 19 and, arranged thereon via a 
shoulder 20, a nose extension 21 which has a hole 22 to receive the swivel 
joint 14. 
On the support plate 19, there is placed a guide arm 23 which, upon the 
placing together of jaw parts 6/7 and receivers 8/9, slides into the guide 
slot 16. In this way, the jaw part 6/7 is guided in direction towards a 
detent hole 24 which, in the position of use, is passed through by the 
detent pin 11. By pressure on the jaw part 6 or 7, the detent pin 11 snaps 
into the detent hole 18 in the region of the guide slot 16, whereby the 
jaw parts 6/7 are detachably connected to the receiver 8/9. 
Jaw parts 6 and 7 are preferably located in a mounting adapter 25 which is 
preferably so developed that the jaw parts 6 and 7 rest snugly in a recess 
26 of a housing 27. The housing 27 is preferably provided on its outer 
surface with a fluting 28, so that a better transmission of force is 
effected upon the pushing of the mounting adapter 25 on the two receivers 
8 and 9. In this connection, the diameter of the detent hole 18 is reduced 
to such an extent as compared with the diameter of the detent pin 11 that 
a pushing-on by means of the mounting adapter 25 is possible, but a 
pulling-off of the jaw parts 6/7 from the receivers 8/9 by means of only 
the fingers of the operator or some other person is not possible. 
For the better fixing of the jaw parts 6/7 and the handling thereof upon 
the pushing onto the receivers 8 and 9, holes 29 are furthermore provided 
in the jaw parts 6/7, through which holes pins, for instance, can be 
inserted for locking the jaw parts 6/7 in the mounting adapter 25. 
For the receiving of the receivers 8/9, the mounting adapter 25 furthermore 
has a guide channel 30 which leads the receivers 8 and 9 to the jaw parts 
6 and 7. 
In a further embodiment, shown in FIG. 9, a jaw part 6.1 has an extension 
15.1, two strips 31 and 32 forming a guide slot 16.1. Within this guide 
slot 16.1, there is arranged an elastic tongue 33 which has a detent nose 
34. Furthermore, a neck 35 of the tongue 33 is tapered, so that a 
deflecting of the tongue 33 out of a position of rest, described later, is 
facilitated. 
Towards its end, engagement projections 36 and 37 are formed on each strip 
31, 32, said projections engaging, in position of use, in corresponding 
troughs 38 and 39 of a receiver 8.1 (see FIG. 11). The receiver 8.1 has a 
wider nose extension 21.1 into which, on the one hand, a hole 22 is 
developed to receive a joint part (not further shown) and, on the other 
hand, a hole 24.1 to receive a pin. 
Adjoining the nose extension 21, there is a support plate 19.1 which is, in 
part, extended over still by a guide arm 23.1 which extends from the nose 
extension 21.1. This guide arm 23.1 terminates in front of a 
hammerhead-shaped transverse slot 40, adjoining which there is a 
longitudinal slot 41 which, in its turn, separates the support 19 into two 
support strips 42 and 43. 
Upon the insertion of the jaw parts 6.1 and 7.1 into the corresponding 
receivers 8.1 and 9.1, the extensions 15.1 slide along the support plate 
19.1, the elastic tongues 33.1 and 33.2 of the two jaw parts 6.1 and 7.1 
respectively being deflected outward with respect to each other. This is 
made possible in the manner that the tongues 33.1 and 33.2 are cut in 
wedge shape so that they leave a wedge-shaped free space 44 open between 
them. Upon the snapping into the transverse slot 40, the detent noses 34 
engage behind corresponding undercuts 45 which are formed by the 
transverse slot 40 upon the transition into the longitudinal slot 41. 
This arrangement assures also the possibility of a simple loosening of the 
jaw parts 6.1 and 7.1 from the corresponding receivers 8.1 and 9.1. It is 
merely necessary to introduce a corresponding tool into the longitudinal 
slot 41 or transverse slot 40 which deflects the elastic tongues 33.1 and 
33.2 apart from each other, as a result of which the detent noses come 
loose from the undercuts 45. 
The embodiment of a structural part shown in FIGS. 15 and 16 is similar to 
that shown in FIGS. 9-14. To be sure, in this case, an extension 15.3 does 
not have a continuous guide slot, but the elastic tongue 33 is formed from 
the extension 15.3 by means of a C-shaped slot 53. 
Furthermore, the extension 15.3 has on its end a trough-shaped development 
54 which cooperates with a corresponding engagement projection (not shown 
in detail) of a correspondingly shaped receiver. 
A receiver 8.2 in accordance with FIGS. 15 and 16 also has a support plate 
19.2 which is developed on a nose extension 21.2. On this support plate 
19.2 there is a guide arm 23.2 the rear edge 46 of which is at distance a 
from the nose extension 21.2. From this edge 46, a rising surface 47 
rises, it then terminating in a block-like extension 48. In this 
block-like extension 48 there are developed, from the front, adjoining the 
support plate 19.2, two grooves 49.1 and 49.2 into which, in position of 
use, arms 50.1 and 50.2 of a jaw part 6.2 engage. These arms 50.1 and 50.2 
are parts of a stepped recess 51 which is formed from a corresponding 
extension 15.2. In this way, a detent arm 52 is then developed also on the 
end of the extension 15.2. This detent arm 52 snaps into the region 
between the edge 46 and the nose extension 21.2 and engages behind the 
edge 16. At the same time, the jaw part 6.2 is guided with the arms 50.1 
and 50.2 in the grooves 49.1 and 49.2 of the guide arm 23, so that, in 
this way, the jaw part 6.2 is held fast on the receiver 8.2 The advantage 
of this embodiment of the connection between jaw part 6.2 and the receiver 
8.2 is that the jaw part 6.2 can be detached from the receiver 8.2 only 
when the detent arm 52 or the extension 15.2 is so bent-off that the 
detent arm 52 can slide onto the rising surface 47. In this case, it is 
immaterial whether the corresponding guide arms from adjacent recesses are 
directed towards each other or in opposite directions towards the outside.