the surgical instrument system illustrated in fig1 consists of an inventive surgical instrument system comprising a hollow shaft 1 as well as a medical shaft - type instrument 2 that can be inserted into the hollow shaft 1 . the hollow shaft 1 consists essentially of a hollow cylindrical tube on whose proximal end rinsing connections 3 and a coupling mechanism 4 for locked fixing of the medical shaft - type instrument 2 that is inserted into the hollow shaft 1 are positioned . in the illustrated embodiment of the hollow shaft 1 , the distal end of the hollow shaft 1 comprises a return spring 5 , but it is also possible of course to configure the distal end of the hollow shaft 1 in such a way that said end ends straight or has a distal end of a different shape or type . as can be seen in particular from fig2 and 3 , the hollow shaft 1 in the area of its distal end comprises three notches 6 that are distributed over the perimeter of the hollow shaft 1 and that configure point - shaped cams 7 that reduce the inside diameter of the hollow shaft 1 on the inside of the hollow shaft 1 . with the illustrated embodiment of the hollow shaft 1 , the cams 7 are positioned in a circle at an equal distance from the distal end of the hollow shaft 1 . it is also possible of course to arrange more or fewer cams 7 and cams 7 in other arrangements on the inside of the hollow shaft 1 . in addition , the illustrated configuration of the cams 7 as point - shaped cams 7 , which are formed by in - curving of the surrounding surface of the hollow shaft 1 , constitutes only one possible means of designing and configuring the cams 7 . what &# 39 ; s essential is that the cams 7 in some sections reduce the inside diameter of the hollow shaft 1 . the shaft - type instrument 2 configured as a mandrel , for instance an obturator , consists , as can be seen from fig1 , 4 , and 5 , essentially of a lengthwise extended shaft 8 whose distal end is configured as a rounded point 9 and on whose proximal end a handle 10 is positioned , which on the one hand facilitates the insertion and withdrawing of the shaft 8 into and out of the hollow shaft 1 and , on the other hand , constitutes a limiting stop for the insertion depth of the shaft 8 into the hollow shaft 1 . the handle 0 , in addition , comprises appropriate catching instruments to secure the shaft - type instrument 2 on the coupling mechanism 4 of the hollow shaft 1 . as can be seen in particular from fig4 and 5 , the shaft 8 of the shaft - type instrument 2 in the area of the distal end comprises three recesses 11 configured as grooves that are distributed over the perimeter of the shaft 8 and correspond with the cams 7 of the hollow shaft 1 . these grooves 11 serve , despite the cams 7 configured on the inside of the hollow shaft 1 , to completely fill the hollow shaft 1 with the shaft 8 of the shaft - type instrument 2 that is to be inserted , when this is required . as shown in fig7 , the cams 7 engage with the grooves 11 and thereby allow an essentially fully flat lining of the hollow shaft 1 by the shaft 8 of the shaft - type instrument 2 inserted into the hollow shaft 1 . when it is required , however , that free space , for instance in the form of a rinsing area 12 ( fig8 ), should remain between the inner surrounding surface of the hollow shaft 1 and the outer surrounding surface of the shaft of the shaft - type instrument 2 that is to be inserted into the hollow shaft 1 , these cams 7 configured on the inside of the hollow shaft 1 , with a shaft 13 without recesses 11 , for instance the shaft 13 of an endoscope lens system , produce this required distance because the shaft 13 with its surrounding surface is contiguous with the cams 7 and thus is held at a distance from the inside wall of the hollow shaft 1 . alternatively to the previously described configuration of the rinsing area 12 on a shaft without recesses 11 , it is also possible to configured the rinsing area 2 in that the depth of the recesses / grooves in the shaft 8 or 3 of the shaft - type instrument 2 is less than the height of the cams 7 , so that the width of the rinsing area 12 can be determined by the depth of the recesses / grooves 11 . the sectional view in fig8 shows a division of the rinsing area 12 into three rinsing channels . it should be pointed out that these rinsing channels are configured only in the immediate contact vicinity of the shaft 3 on the cams 7 , but before and behind the cams 7 the rinsing area takes up the entire perimeter surface between the inside surrounding surface of the hollow shaft 1 and the outer surrounding surface of the shaft 13 of the shaft - type instrument that is to be inserted into the hollow shaft 1 . in a first operational step , for instance by means of a sharp trocar mandrel , at least one skin incision is produced by which thereafter the medical instruments required for the endoscopic operation can be conveyed to the operating area . the medical instruments are inserted through the skin incision into the operating area by means of sleeves , such as the hollow shaft 1 , inserted into the skin incision . because the operationally produced cut of the skin incision is to be kept as small as possible , but thereafter medical instruments with a larger diameter must also be inserted into the operating area , it is necessary thereafter , after configuring the skin incision , to widen the skin incision by using the tissue elasticity . the widening can , for instance , be carried out by means of the shaft - type instrument 2 , which is pushed with its rounded point 9 forward into the skin incision and widens said incision with the conical shape of the point 9 upon further insertion of the shaft 8 . to be able to inserted the hollow shaft 1 into the skin incision simultaneously with the widening of the skin incision , first the shaft - type instrument 2 is inserted into the hollow shaft until the cams 7 of the hollow shaft 1 engage in the recesses / grooves 1 of the shaft 8 . in this combination depicted in fig6 , the instrument system is inserted into the skin incision . to avoid injuries of the tissue upon insertion of the hollow shaft into the skin incision by the sharp distal end edge of the hollow shaft 1 , it is urgently necessary in this stage of the operation that the shaft 8 of the shaft - type instrument 2 inserted into the hollow shaft 1 completely fills up the hollow shaft 1 , in particular at the distal end , in order thereby to ensure seamless transition from the outer diameter of the shaft 8 to the outer diameter of the hollow shaft 1 . after placing the hollow shaft 1 in the skin incision , the shaft - type instrument 2 in the form of an expansion mandrel can be withdrawn again from the hollow shaft 1 . the hollow shaft henceforth forms a free accessway to the operating area , through which further medical instruments can be inserted into the operating area . upon inserting an endoscope lens system into the operating area , to ensure a constantly clear field of vision it is necessary to rinse the lens system . as can be seen from fig8 , said necessary rinsing area 12 is produced inside the hollow shaft 1 in that the shaft 13 of the endoscope lens system has no recesses / grooves , so that the shaft 13 with its surrounding surface is contiguous with the cams 7 and thus is held at a distance from the inside wall of the hollow shaft 1 while forming the rinsing area 12 . to be able to insert the insertable medical shaft - type instrument 2 into the hollow shaft 1 in simple manner and in the correct alignment to the hollow shaft 1 , an additional cam 7 can be positioned on the inside of the hollow shaft 1 in addition in the area of the proximal end , and in the shaft 8 of the shaft - type instrument 2 that is to be inserted into the hollow shaft 1 a recess 11 can be configured that corresponds with the addition cam 7 and extends from the distal end of the shaft 8 to the height of the additional cam 7 . the surgical instrument system of this configuration is characterized in that it ensures both a range of possible uses and a constantly high degree of operating safety and ease of operation .
the invention relates to a surgical instrument system , which comprises a hollow shaft as well as a shaft - type instrument that can be inserted into the hollow shaft . to create a surgical instrument system that consists of a hollow shaft and of a medical instrument that can be inserted into the hollow shaft and that is both simple in construction and capable of a range of uses , it is proposed according to the invention that at least one cam that reduces the inside diameter of the hollow shaft should be positioned on the interior of the hollow shaft .