1. A tape advancing system for precisely advancing a tape through a targeting area, the tape having first and second opposing faces wherein the second face is positioned by the system for irradiation by a laser within the targeting area, the system comprising:
a first positioning device configured to receive the first face of the tape against a first positioning surface;
a second positioning device configured to receive the first face of the tape against a second positioning surface that is substantially perpendicular to the first positioning surface, the tape twisting by substantially 90\xb0 between the first and second positioning devices;
a third positioning device configured to receive the second face of the tape against a third positioning surface that is substantially parallel to the second positioning surface, wherein the third positioning surface imparts a tensioning force to the tape against the second positioning surface as the tape is advanced through the system;
a first guide wing configured to receive the first face of the tape against a first guide wing surface that is substantially parallel to the third positioning surface to further position the tape so that the tape is aligned with the targeting area;
a second guide wing configured to receive the second face of the tape against a second guide wing surface that is substantially parallel to the first guide wing surface so that the tape passes through the targeting area; and
a drive roller having a longitudinal axis parallel to the first and second guide wing surfaces and configured to receive the first or second face of the tape against its surface, wherein the tape is pressed between the drive roller and an idler roller to create a tension on the tape sufficient to pull the tape through the system.
2. A tape advancing system according to claim 1, wherein the positioning devices comprise cylindrical rods.
3. A tape advancing system according to claim 1, wherein the tape is provided on a spool having a longitudinal axis parallel to a longitudinal axis of the first rod.
4. A tape advancing system according to claim 3, wherein the first surface of the tape is in contact with the first positioning surface as the tape is exhausted from the spool.
5. A tape advancing system according to claim 4, wherein the first positioning device is adjustable along a first plane that is substantially orthogonal to the first and second surfaces of the tape to ensure that the first surface of the tape is in contact with the first positioning surface as the tape is exhausted from the spool.
6. A tape advancing system according to claim 1, further comprising a tensioning device configured to apply tension to the tape by providing a compressing force against the first face of the tape towards the third positioning surface of the third positioning device.
7. A tape advancing system according to claim 1, wherein the first and second guide wings comprise chordal cross-sections wherein the first and second guide wing surfaces are proximate to the point on the exterior surfaces of the first and second guide wings where an arcuate surface meets a flat surface of the chordal cross-section.
8. A tape advancing system according to claim 7, wherein the first and second guide wings are each rotationally adjustable to control the rotational position of the first and second guide wing surfaces.
9. A tape advancing system according to claim 7, wherein the flat surface of the second guide wing is oriented toward the first guide wing such that the tape contacts an edge of the second guide wing where a flat surface meets an arcuate surface of its chordal cross-section.
10. A tape advancing system according to claim 9, wherein the angle between the flat surface of the second guide wing and the second face of the tape is greater than 90\xb0.
11. A tape advancing system according to claim 1, further comprising a groove formed in the exterior surface of the second guide wing surface for receiving the tape therein, wherein a width of the groove is slightly larger than the width of the tape.
12. A tape advancing system according to claim 1, wherein the idler roller is adjustable with respect to the drive roller in order to adjust the amount of tension provided to the tape as the tape is advanced through the system.
13. A tape advancing system according to claim 1, further comprising pinch rollers configured to receive the tape from the second guide wing and to compress the tape therebetween to reduce surface protrusions on the tape.
14. A tape advancing system according to claim 1, wherein the tape is pressed between the drive roller and an idler roller to create a tension on the tape sufficient to pull the tape through the system at a substantially constant velocity.
15. A method for advancing a tape through a targeting area, the method comprising:
receiving a tape having first and second opposing faces, wherein the second face is positioned for irradiation by a laser within a targeting area, from a tape source;
imparting a first positioning force on the first face of the tape to position the tape in a first direction along a first axis;
imparting a second positioning force on the first face of the tape to position the tape in a first direction along a second axis perpendicular to the first axis, the tape twisting by 90\xb0 between the first and second positioning forces;
imparting a third positioning force on the second face of the tape to further position the tape in a second direction along the second axis opposite to the first direction along the second axis, the third positioning force imparting a tensioning force to the tape opposite to the second positioning force as the tape is advanced through the system;
guiding the tape into the targeting area by imparting a first guiding force on the first face of the tape to further position the tape in the first direction along the second axis;
guiding the tape out of the targeting area by imparting a second guiding force on the second face of the tape to further position the tape in the second direction along the second axis; and
pulling the tape from the tape source while a position of the tape is affected by the positioning and guiding forces.
16. A method according to claim 15, wherein any or all of the positioning forces are adjustable in their respective directions.
17. A method according to claim 15, further comprising applying tension to the tape to slow its advance substantially where the third positioning force is applied to the tape.
18. A method according to claim 15, wherein guiding the tape into the targeting area by imparting a first guiding force further comprises imparting the first guiding force with a first guide wing surface.
19. A method according to claim 15, wherein guiding the tape out of the targeting area by imparting a second guiding force further comprises imparting the second guiding force with a second guide wing surface.
20. A method according to claim 19, wherein imparting the second guiding force further comprises orienting a flat surface of a second guide wing towards the targeting area.
21. A method according to claim 15, further comprising imparting a fourth positioning force on the edges of the tape and along the first axis.
22. A method according to claim 21, wherein the fourth positioning force is applied by the second guide wing.
23. A method according to claim 15, further comprising compressing the first and second surfaces of the tape with a compression force after it exits the targeting area.
24. A method according to claim 23, wherein the compression force is employed for the pulling of the tape.
25. A method according to claim 23, wherein the compression force is adjustable.
26. A method according to claim 15, further comprising pulling the tape from the tape source at a substantially constant velocity while a position of the tape is affected by the positioning and guiding forces.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-20. (canceled)
21. An endoscopic instrument, comprising:
a housing;
a spring carrier supported within the housing;
a shaft assembly configured for releasable engagement with the housing and the spring carrier, the shaft assembly including first and second shaft members and a bushing, the bushing slidably engaged to the first shaft member and fixedly engaged to the second shaft member such that the first shaft member is slidable relative to the second shaft member and the bushing;
an end effector supported at a distal end of the shaft assembly; and
a locking mechanism including a first locking component and a second locking component, the locking mechanism transitionable from an unlocked condition permitting insertion and removal of the shaft assembly from the housing, and a locked condition, wherein the first locking component engages the first shaft member with the spring carrier such that actuation of the spring carrier effects axial movement of the first shaft member, and the second locking component engages the busing with the housing to longitudinally fix the bushing and the second shaft member relative to the housing.
22. The endoscopic instrument according to claim 21, wherein the second shaft member is coaxially disposed within the first shaft member.
23. The endoscopic instrument according to claim 21, wherein the bushing defines an annular groove and wherein, in the locked condition, the second locking component is engaged within the annular groove to longitudinally fix the bushing and the second shaft member relative to the housing.
24. The endoscopic instrument according to claim 23, wherein the second locking component is a latch defining an aperture configured to receive the bushing therethrough.
25. The endoscopic instrument according to claim 23, wherein the bushing is rotatable relative to the housing when engaged therewith.
26. The endoscopic instrument according to claim 21, wherein the first shaft member includes a proximal flange and wherein the first locking component, in the locked condition, is configured to engage the proximal flange with the spring carrier to thereby engage the first shaft member with the spring carrier.
27. The endoscopic instrument according to claim 26, wherein the first locking component is a C-shaped locking member.
28. The endoscopic instrument according to claim 26, wherein the first shaft member is rotatable relative to the spring carrier when engaged therewith.
29. The endoscopic instrument according to claim 21, wherein the first and second locking components are fixedly engaged with one another.
30. The endoscopic instrument according to claim 29, wherein at least a portion of the first locking component or the second locking component extends from the housing to enable manual manipulation thereof to transition the locking mechanism between the locked condition and the unlocked condition.
31. The endoscopic assembly according to claim 21, wherein the end effector includes an ultrasonic jaw member and a clamping jaw member, the clamping jaw member movable relative to the ultrasonic jaw member between a spaced-apart position and an approximated position in response to sliding of the first shaft member relative to the second shaft member.
32. The endoscopic assembly according to claim 31, further comprising a handle operably coupled to the housing and the spring carrier, the handle movable relative to the housing to actuate the spring carrier to, in turn, slide the first shaft member relative to the second shaft member.