embodiments of surgical instruments in accordance with the present disclosure will now be described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical structural elements . as shown in the drawings and described throughout the following description , as is traditional when referring to relative positioning on a surgical instrument , the term “ proximal ” refers to the end of the apparatus which is closer to the user and the term “ distal ” refers to the end of the apparatus which is further away from the user . referring now to the drawings , wherein like reference numerals identify identical or similar structural elements of the subject device through out the several views , there is illustrated in fig1 - 13 , a surgical instrument , designated generally by reference numeral 10 . u . s . patent application ser . no . 11 / 786 , 933 , filed on apr . 13 , 2007 , the entire content of which is incorporated herein by reference , describes in detail the structure and operation of an exemplary surgical instrument that may incorporate or be used with the presently disclosed adapter assembly . as seen in fig1 and 1a , a rotational interface 100 is shown connected with or otherwise supported on surgical instrument 10 . surgical instrument 10 includes a housing 12 , at least one drive assembly 14 and at least one energy source for powering the at least one drive motor ( not shown for clarity ). as seen in fig1 a , rotational interface 100 is configured and adapted to operatively interconnect and couple any one of a number of end effectors to surgical instrument 10 . for example , rotational interface 100 is configured and adapted to operatively interconnect and couple an endo - gastrointestinal anastomosis end effector 90 , an end - to - end anastomosis end effector 91 , or a transverse anastomosis end effector 92 to surgical instrument 10 . reference may be made to u . s . patent publication no . 2009 / 0145947 , filed jan . 14 , 2009 , the entire content of which is incorporated herein by reference for a detailed discussion of the construction and operation of the endo - gastrointestinal anastomosis end effector 90 . reference may be made to u . s . patent publication no . 2009 / 0179063 , filed mar . 20 , 2009 , the entire content of which is incorporated herein by reference for a detailed discussion of the construction and operation of the end - to - end anastomosis end effector 91 . reference may be made to u . s . pat . no . 6 , 817 , 508 , issued nov . 16 , 2004 , the entire content of which is incorporated herein by reference for a detailed discussion of the construction and operation of the transverse anastomosis end effector 92 . as seen in fig2 , housing 12 of surgical instrument 10 supports the drive assembly 14 . drive assembly 14 includes a drive shaft 15 translatably , slidably , or rotatably supported between right side half - section 12 a and left side half - section 12 b of housing 12 , for movement of the drive shaft 15 along or about a longitudinal ‘ x ’ axis of surgical instrument 10 . each of the end effectors 90 , 91 , and 92 includes at least one axially translatable drive member therein that is connectable with the drive shaft 15 , and that is configured and adapted to at least one of open and close the jaw assemblies by approximating or separating the anvil assembly and the cartridge assembly to / away from one another , and to fire the end effector to expel staples contained in the cartridge assembly for formation against the anvil assembly and possibly to actuate a knife blade along the staple line . each of end effectors 90 , 91 , and 92 may further include an axially translatable drive member therein that is configured and adapted to cause an articulation of end effector 90 , 91 , and / or 92 . with continued reference to fig1 and 1a , a detailed description of the construction and operation of rotational interface 100 is provided . rotational interface 100 includes a knob housing 102 configured and adapted to connect to a nose portion 20 ( fig2 ) of the housing 12 . knob housing 102 includes an articulation lever 104 mounted on the forward end of housing 12 to facilitate articulation of the drive assembly 14 with respect to the longitudinal ‘ x ’ axis . knob housing 102 may be formed in a pair of knob housing halves , namely an upper knob housing half 102 a and a lower knob housing half 102 b . rotational interface 100 further includes an outer tube 106 extending from a distal end of knob housing 102 along longitudinal ‘ x ’ axis . knob housing 102 and outer tube 106 are configured and dimensioned to contain the components of rotational interface 100 . outer tube 106 may be dimensioned such that outer tube 106 may pass through a typical trocar port , cannula or the like . knob housing 102 is secured to outer tube 106 in such a manner that rotation of knob housing 102 results in rotation of the outer tube 106 . as seen in fig2 , 3 , and 6 , the nose portion 20 of the housing 12 defines a cylindrical passageway 21 that contains an electrical coupling assembly 110 . the electrical coupling assembly 110 includes a spool 120 and a bushing 150 ( see fig9 and 10 ). electrical coupling assembly 110 allows passage of a portion of the drive shaft 15 through a center passage 122 in the spool 120 . the bushing 150 is restrained by and is fixed with respect to the housing 12 . the spool 120 has an elongate tubular portion 124 that is rotatably attached within the bushing 150 . as seen in fig9 and 10 , a distal portion 121 of the spool 120 includes a distal flange 126 extending radially outward from the elongate tubular portion 124 . a proximal flange 128 extends about the proximal end 123 of the elongate tubular portion 124 . proximal flange 128 abuts against distal flange 126 and has a radius 137 that is relatively smaller than a radius 138 of distal flange 128 . a helical recess 130 extends longitudinally about the elongate tubular portion 124 between the distal flange 126 and the proximal flange 128 . the distal flange 126 defines a distal , longitudinally extending passageway or channel 132 through the distal flange 126 . a distal boss 134 extends distally about the distal channel 132 from the distal flange 126 . a shoulder 136 is defined by the difference of radius 137 and radius 138 of the distal flange 126 . the radius 137 is sized to allow an inner portion 136 a to fit inside cylindrical passageway 21 and an outer portion 136 b to be slightly larger than the cylindrical passageway 21 . the bushing 150 has a center aperture 152 that is sized to receive the proximal portion 123 of the elongate tubular portion 124 . the aperture 152 allows the bushing 150 to be placed about the elongate tubular portion 124 and slide up to the proximal flange 128 . a proximal boss 156 extends proximally from the bushing 150 . a proximal , longitudinally extending passageway or channel 154 is defined in an outer edge 158 of the bushing 15 . a proximal boss 156 extends proximally about the proximal channel 154 of the bushing 150 . a recessed circumferential channel 160 encircles at least a portion of the outer edge 158 of the busing 150 . as shown in fig3 , 6 , and 9 - 13 , the surgical instrument 10 includes an electrical wire 24 having a first portion extending through the proximal channel 154 of the bushing 150 , a second portion wrapped about the elongated tubular portion 124 , and a third portion that extends distally through the distal channel 132 of distal flange 126 . with reference to fig3 , the bushing 150 is nested between the right side half section 12 a and the left side half section 12 b of the housing 12 . at least one protrusion 40 extends from the nose portion 20 into the radial channel 160 of the bushing 150 to rotationally secure the bushing 150 in place relative to the nose portion 20 and to prevent longitudinal movement of the bushing 150 . as seen in fig3 and 6 , the distal flange 126 of the spool 120 is rotatably interposed between the nose portion 20 of the housing 12 and the knob housing 102 , allowing the spool 120 to rotate and preventing the spool 120 from moving along the longitudinal ‘ x ’ axis . the housing 12 prevents proximal movement of the spool 120 by the abutment of the shoulder 136 with the nose portion 20 . distal movement of the spool 120 is prevented by abutment of the distal flange 126 with the knob housing 102 . as seen in fig4 - 6 , the surgical instrument 10 includes a rotation limiting mechanism 50 that interacts with the outside of the nose portion 20 and the inside of the knob housing 102 . the rotation limiting mechanism 50 includes a ball bearing 52 located within both a longitudinal recess 103 , in the upper knob housing half 102 a , and a spiral cam slot or helical recess 22 ( see fig2 ), defined about the nose portion 20 of housing 12 . the rotation limiting mechanism 50 allows the rotational interface 100 to rotate about the nose portion 20 . as shown , rotation limiting mechanism 50 allows the rotational interface 100 to rotate approximately 700 °; however other degrees of rotation are envisioned . with reference to fig4 and 5 , the longitudinal recess 103 defines a neutral detent 103 a half way between a proximal end 103 b and a distal end 103 c of the longitudinal recess 103 . the neutral detent 103 a provides a tactile indication to the user of a neutral position of the rotational interface 100 . the ball bearing 52 travels longitudinally within the longitudinal recess 103 as the knob housing 102 of rotational interface 100 is rotated about the longitudinal ‘ x ’ axis . the ball bearing 52 is shown in a neutral position in fig6 , a distal most extreme position in fig7 , and in a proximal most extreme position in fig8 . in use , as the rotational interface 100 is rotated about the nose portion 20 , the ball bearing 52 is also rotated about the nose portion 20 . the ball bearing 52 rides in the helical recess 22 and is prevented by further travel when ball bearing 52 reaches one of the extreme ends 13 b , 103 c of longitudinal recess 103 to thereby limit the degree of rotation of knob housing 102 of rotational interface 100 . at the extreme ends of the longitudinal recess 103 , the ball bearing 52 acts against the ends 103 b , 103 c thereof to prevent the rotational interface 100 from rotating further with respect to the housing 12 . with reference to fig1 - 13 , the wire 24 is shown in various stages during the rotation process of the rotational interface 100 . the wire 24 is relatively loose about the spool 120 when the rotational interface 100 is in a neutral position and the ball bearing 52 is in the neutral detent 103 a , as shown in fig6 . the wire 24 is unwrapped and is forced radially outward about the spool 120 , as shown in fig1 , when the rotational interface 100 is rotated in a first direction and the ball bearing 52 is drawn distally . rotating the rotational interface 100 in a second direction , opposite to the first direction , as shown in fig1 , wraps the wire 24 tighter about the spool 120 to draw the wire 24 radially inward toward the spool 120 . the helical recess 130 may provide a predefined path for the wire 24 as the wire 24 is tightened about the spool 120 . by adding or subtracting the number of loops of wire 24 wrapping around spool 120 and adjusting the length of the helical and longitudinal recesses ; the rotational range of spool 120 , knob housing 102 , and / or rotational interface 100 can be increased or decreased . in order to reduce electrical noise emissions and / or susceptibility , it is contemplated that circumferential shielding may be added around wire 24 wrapped around spool 120 and / or wires may be twisted . it should be understood that the foregoing description is only illustrative of the present disclosure . various alternatives and modifications can be devised by those skilled in the art without departing from the disclosure . accordingly , the present disclosure is intended to embrace all such alternatives , modifications and variances . the embodiments described with reference to the attached drawing figures are presented only to demonstrate certain examples of the disclosure . other elements , steps , methods and techniques that are insubstantially different from those described above and / or in the appended claims are also intended to be within the scope of the disclosure . therefore , the above description should not be construed as limiting , but merely as exemplifications of embodiments . those skilled in the art will envision other modifications within the scope and spirit of the present disclosure .
a surgical apparatus for performance of a surgical procedure on body tissue is provided and includes a housing , an elongate tubular member , a drive assembly , an electrical coupling component , and an electrical wire . the elongate tubular member is at least partially supported by the housing and defines a center lumen and a longitudinal axis . the drive assembly extends from the housing into the center lumen of the elongate tubular member . the electrical coupling component is located about the drive assembly . the electrical wire extends from within the housing into the elongate tubular member . the electrical wire is wrapped about the electrical coupling component , which allows the elongate tubular member to rotate about the longitudinal axis while allowing the electrical wire to be fixed within the housing and the elongate tubular member .