Apparatus for applying surgical clips

A surgical clip applying instrument is disclosed which includes a handle portion having a first handle and a second handle mounted for relative movement. The handles define a single closing stroke between an open position and a closed position. The closing stroke includes an initial throw, an intermediate throw, and a final throw. The clip applying instrument includes body portion extending distally from the handle portion and defining a longitudinal axis, and a plurality of surgical clips disposed within the body portion. A jaw assembly including first and second jaw portions is mounted at the distal end portion of the body portion and is movable between an approximated position and a spaced position. A jaw control mechanism is configured to move the jaw portions to the spaced position for reception of a distalmost clip in response to the initial throw of the handles. The jaw control mechanism is configured to maintain the jaw portions in the spaced position during the intermediate throw of the handles. In addition, the jaw control mechanism is configured to move the jaw assembly to the approximated position to deform the distalmost clip in response to the final throw of the handles. A clip advancer is also provided to individually distally advance the distalmost clip to the jaw assembly during the intermediate throw of the handles. A method for assembly of a surgical instrument is also disclosed.

BACKGROUND 
1. Technical Field 
The present disclosure relates to apparatus for applying surgical clips to 
body tissue. In particular, the disclosure relates to surgical clip 
appliers configured to be inserted through relatively narrow access 
devices such as those used in laparoscopic or endoscopic procedures. 
2. Description of the Related Art 
Laparoscopic procedures are performed in the interior of the abdomen 
through a small incision, e.g., through narrow endoscopic tubes or 
cannulas inserted through a small entrance incision in the skin. Minimally 
invasive procedures performed elsewhere in the body are often generally 
referred to as "endoscopic" procedures. Typically in such procedures, a 
tube or cannula device is extended into the patient's body through the 
entrance incision to provide an access port which allows insertion of 
various surgical instruments therethrough. These instruments are used for 
performing surgical procedures on organs, blood vessels, ducts, or body 
tissue far removed from the incision. Often during these procedures, it is 
necessary to apply hemostatic clips to blood vessels or various ducts to 
prevent the flow of body fluids therethrough during the procedure. 
Multiple endoscopic clip appliers (i.e., clip appliers that are able to 
apply multiple clips in endoscopic or laparoscipic procedures during a 
single entry into the body cavity) are described in commonly-assigned U.S. 
Pat. Nos. 5,084,057 and 5,100,420 to Green et al., the disclosures of 
which are hereby incorporated by reference herein. Other multiple 
endoscopic clip appliers are disclosed in commonly-assigned copending U.S. 
patent application Ser. Nos. 08/134,347, filed Oct. 8, 1993 by Pratt et 
al., now U.S. Pat. No. 5,607,436 and 08/515,341, filed Aug. 15, 1995 by 
Pier et al., the contents of which are also hereby incorporated by 
reference herein. 
One advantage of minimally invasive surgical procedures is the reduction of 
trauma to the patient as a result of accessing internal organs through 
smaller incisions. Known multiple endoscopic clip appliers have greatly 
facilitated the advent of more advanced minimally invasive procedures by 
permitting multiple clip applications during a single entry into the body 
cavity. Commercially available multiple endoscopic clip appliers are 
generally of 10 mm outer diameter and are adapted to be introduced through 
a 10 mm cannula. As minimally invasive procedures continue to evolve and 
the advantages thereof are extended to additional clinical applications, 
it has become desirable to further reduce incision size(s) and therefore 
the size of all instrumentation introduced therethrough. 
The structure of surgical instruments intended to perform numerous 
functions within a confined space is necessarily complex. Consequently, 
the assembly process for these instruments is often complicated and may 
involve numerous relatively small parts. 
It is therefore desirable to maximize the ease with which such instruments 
may be assembled. 
It is also desirable to provide a multiple endoscopic clip applier having 
structure which facilitates the application of surgical clips while 
further minimizing the required incision size at the surgical site. 
SUMMARY 
The subject disclosure is directed to a unique surgical clip applying 
instrument which includes a handle portion having first and second handles 
mounted for relative movement. The handles define a single closing stroke 
between an open position and a closed position. The closing stroke 
includes an initial throw, an intermediate throw, and a final throw. The 
clip applying instrument includes a body portion extending distally from 
the handle portion and defining a longitudinal axis, and a plurality of 
surgical clips disposed within the body portion. 
A jaw assembly, including first and second jaw portions, is mounted at the 
distal end portion of the body portion and is movable between a 
substantially approximated position and a spaced position. A jaw control 
mechanism is provided which cooperates with the jaw assembly to effectuate 
movement thereof. In one embodiment, the jaw control mechanism is 
configured to move the jaw portions from the substantially approximated 
position to the spaced position for reception of a distalmost clip in 
response to the initial throw of the handles. In a second embodiment, the 
jaw control mechanism ensures that the jaw portions are in the spaced 
position for reception of a distalmost clip in response to the the initial 
throw of the handles. 
The jaw control mechanism is configured to maintain the jaw portions in the 
spaced position during the intermediate throw of the handles. In addition, 
the jaw control mechanism is configured to move the jaw assembly to the 
substantially approximated position to deform the clip within the jaw 
assembly in response to the final throw of the handles. A clip advancer is 
also provided to individually distally advance a distalmost clip to the 
jaw assembly, preferably during the intermediate throw of the handles. 
A method for assembly of a surgical instrument is also disclosed which 
includes providing a handle subassembly having a driver member mounted for 
longitudinal movement in response to actuation of the handle subassembly. 
An actuator subassembly is provided including a proximal mounting portion 
for engagement with the driver member and a distal mounting portion. A 
tool subassembly is provided having a proximal mounting portion configured 
to engage the distal mounting portion of the actuator subassembly. The 
actuator subassembly is assembled with the handle subassembly such that 
the proximal mounting portion of the actuator subassembly is in engagement 
with the driver member. The actuator subassembly is assembled with the 
tool subassembly such that the proximal mounting portion of the tool 
assembly is in engagement with the distal mounting portion of the actuator 
subassembly.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
The preferred embodiments of the apparatus disclosed herein will be 
discussed in terms of endoscopic procedures and apparatus. However, use 
herein of terms such as "endoscopic" should not be construed to limit the 
present application to an apparatus for use in conjunction with an 
endoscopic tube. In addition, it is believed that the present apparatus 
may find use in laparoscopic or arthroscopic surgery wherein access to the 
surgical site is achieved through a narrow cannula, or a small incision. 
In the drawings and in the description which follows, the term "proximal," 
as is traditional, will refer to the end of the apparatus which is closest 
to the operator, while the term "distal" will refer to the end which is 
furthest from the operator. 
Referring now in detail to the drawings in which like reference numerals 
identify similar or identical elements, a preferred embodiment of the clip 
applying instrument of the subject disclosure is illustrated in FIG. 1, 
and is designated generally by reference numeral 10. Clip applying 
instrument 10 includes handle portion 12 having pivoting or movable handle 
14 and stationary handle 16. Manipulation of these handles 14, 16 actuates 
a tool assembly, such as jaw assembly 18, through elongated body portion 
20. The junction at which body portion 20 is joined to handle portion 12 
includes fluted rotation collar 22 for remotely varying the orientation of 
jaw assembly 18 relative to the surgical site. Jaw assembly 18 includes 
first and second juxtaposed jaw portions 24a and 24b, which are 
simultaneously movable between a substantially approximated configuration 
in which jaw portions 24a and 24b are in relatively close relation to one 
another and a spaced configuration in which jaw portions 24a and 24b are 
separatable at least a sufficient distance to receive a surgical clip 
therebetween. 
With continued reference to FIG. 1, movable handle 14 is shown in a fully 
open or "at-rest" position with respect to handle 16. Pivoting movement of 
movable handle 14 with respect to stationary handle 16 in the direction of 
arrow "A" from the open position to the closed position defines a closing 
stroke. During this closing stroke, jaw portions 24a and 24b are cammed 
open to a spaced configuration to receive a surgical clip. Upon further 
pivoting of movable handle 14, jaw portions 24a and 24b are maintained in 
the spaced configuration and the distalmost surgical clip is advanced 
between the spaced apart jaw portions. Final pivoting of movable handle 14 
approximates jaw portions 24a and 24b to deform the clip. 
The subject surgical clip applier 10 will be described with respect to 
various subassemblies. In particular, the surgical clip applier 10 
includes subassemblies for handle portion 12, jaw assembly 18, thrust bar 
72, and a clip advancement structure 130. For manufacturing economy, each 
of these subassemblies can be individually completed at separate 
workstations. Subsequently, the finished subassemblies may be put together 
in a final assembly procedure as will be described in greater detail 
below. 
The Handle Portion Subassembly 
FIG. 2 illustrates the components of handle portion 12 of instrument 10. 
Handle portion 12 includes left and right housing portions 26a and 26b 
respectively, in which the components of the handle portion are 
positioned. Housing portions 26a and 26b are positioned by pins 28a, 28b, 
28c and 28d inserted within apertures 30a, 30b, 30c and 30d, and secured 
together by sonic welding or other known means. Movable handle 14 is 
mounted to housing portions 26a and 26b by pin 32 which permits pivotal 
motion of handle 14 with respect to stationary handle 16. 
Movable handle 14 further includes clevis 34 connected to a driver member, 
such as pusher plate 36, by means of pin connector 38. Pusher plate 36 is 
mounted within longitudinal stepped bore 40 defined in housing portions 
26a and 26b for reciprocal longitudinal motion therein. Clevis 34 includes 
a pair of spaced apart shackles 42a and 42b, each of which has an 
elongated aperture 44a and 44b defined therethrough for reception of pin 
connector 38, which is slidable therein. This sliding arrangement permits 
the user to exert varying levels of torque on the jaw assembly 18 
depending upon the position of pivoting handle 14 with respect to 
stationary handle 16. In particular, greater torque may be necessary to 
close jaw portions 24a and 24b to deform a clip on a blood vessel than to 
cam open the jaw portions or to advance a clip to the jaw assembly. 
Pusher plate 36 is operatively connected to the jaw assembly as will be 
described below. Pusher plate 36 may be stamped or machined from a single 
piece of sheet metal or rigid engineering plastic. Pusher plate 36 
includes an aperture 46 for the reception of pin connector 38. Return 
spring 48, configured to engage shoulder portion 50 of pusher plate 36, is 
provided to normally bias pusher plate 36 proximally and thereby to 
normally bias movable handle 14 to the open position. Ratchet assembly 52 
includes rack 54 having a plurality of ratchet teeth 56 formed on a 
proximal portion of pusher plate 36 and pawl 58 disposed in handle portion 
12. Distal portion 60 and proximal portion 62 of rack 54 are devoid of 
ratchet teeth 56. Pawl 58 is rotatably mounted by pawl pin 64 and normally 
biased into engagement with the ratchet teeth of rack 54 by spring 66. As 
illustrated in FIG. 2A, each of the ratchet teeth 56 on rack 54 is shaped 
having a substantially vertical portion and a substantially sloping 
portion to permit incremental distal advancement of pusher plate 36 while 
restricting proximal movement of pusher plate 36. 
With continued reference to FIG. 2, pusher plate 36 includes bifurcated 
distal portion 68 having prongs 70a and 70b which facilitate rotatable 
mounting to an actuator, such as thrust bar 72. Alternatively, pusher 
plate 36 and thrust bar 72 may be connected by any other known distal 
mounting structure including, e.g. a ball-and-socket arrangement. 
Rotation collar 22 is operatively connected to thrust bar 72 and is 
angularly rotatable therewith. Rotation collar 22 includes annular flange 
portion 74 rotatably mounted within annular slot 76 formed in housing 
portion 26a and 26b. 
Jaw Assembly Subassembly 
With reference to FIG. 3, jaw assembly 18 includes elongated shank portions 
78a and 78b connected at crown portion 80. Midline 82 is defined through 
each of shank portions 78a and 78b. The portion of jaw assembly 18 
proximal to midline 82 constitutes the proximal portion of jaw assembly 
18. The portion of jaw assembly 18 distal to midline 82 constitutes the 
distal portion of jaw assembly 18. Resilience in shank portions 78a and 
78b permits relative approximation and spacing of juxtaposed jaw portions 
24a and 24b. A pair of elongated channels 84a and 84b is provided on the 
inner surfaces of jaw portions 24a and 24b for reception of a surgical 
clip as will be described below. Jaw assembly 18 further includes proximal 
legs 86a and 86b, having a plurality of radially outwardly extending tabs 
88a, 88b, 88c, and 88d formed thereon. These tabs are used for mounting 
and assembly as will be described in greater detail below. 
FIG. 3A illustrates, in enlarged form, a pair of position tabs 90a and 90b 
disposed on elongated shank portions 78a and 78b respectively, to cam jaw 
portions 24a and 24b as will be described below. 
Turning now to FIG. 4, each of jaw portions 24a and 24b includes raised 
camming surfaces 92a and 92b formed on the bottom surface thereof. In 
order to provide increased closing force, camming surfaces are disposed at 
a distal portion of jaw portions 24a and 24b adjacent inner surfaces 94a 
and 94b of jaw portions 24a and 24b. 
Thrust Bar Subassembly 
Referring to FIG. 5, thrust bar 72 extends along a substantial length of 
body portion 20. Distal portion 96 of thrust bar 72 has a semicircular 
cross-section and includes dual camming structure for opening and closing 
jaw portions 24a and 24b. First, channel structure 98 is configured with a 
racetrack-shaped groove pattern to control and cam jaw portions 24a and 
24b to a spaced-apart position and maintain the jaw portions in the 
spaced-apart position. Second, jaw closure structure 100 includes a 
bifurcated cam configuration to approximate jaw portions 24a and 24b about 
a surgical clip. 
As illustrated in FIG. 5A, channel structure 98 includes raised center 
block 102, having distal nose portion 103. Distal zone or recess 104 is 
disposed distal to center block 102. A pair of longitudinally elongated 
parallel channels 106a and 106b extend along the sides of center block 
102. Proximal zone or recess 108 is disposed proximal to center block 102. 
Position tabs 90a and 90b of jaw assembly 18 are configured to slide 
within channel structure 98. 
Jaw closure structure 100 includes a bifurcated configuration having a pair 
of camming surfaces 110a and 110b in a tapering V-shaped configuration to 
cooperate with raised camming surfaces 92a and 92b on jaw assembly 18. In 
particular, distal movement of thrust bar 72 moves camming surfaces 110a 
and 110b into surrounding arrangement with respect to raised camming 
surfaces 92a and 92b, thereby moving jaw portions 24a and 24b into 
approximation. 
A proximal portion of thrust bar 72 includes trip lever assembly 112. Trip 
lever assembly 112 includes trip lever 114 mounted on thrust bar 72 and 
disposed within longitudinally aligned recess 116. Trip lever 114 is 
rotatably retained therein by pivot pin 118 passing through transverse 
aperture 120. Distal tab 122 of trip lever 114 is normally biased upward 
by trip lever spring 124 disposed within cylindrical recess 126. It is 
contemplated that the trip lever and spring arrangement could be 
substituted with other equivalent structure including, e.g., a leaf spring 
or other resilient member. 
A hemispherical portion 128 of thrust bar 72 having a flat upper surface is 
provided distal to the trip lever assembly 112. Both hemispherical portion 
128 and trip lever assembly 112 are configured to engage with clip 
advancement subassembly 130 as will be described below. 
Clip Advancement Subassembly 
Turning now to FIG. 6, clip advancement subassembly 130 is depicted 
including upper housing 132, lower housing 134, and clip advancer or clip 
pusher 136. Upper housing 132 and lower housing 134, in combination, 
define a feed chute sized and configured to facilitate the stacking of 
surgical clips. With reference to FIG. 7, upper housing 132 has a 
substantially semicircular cross-section and includes groove 138 and 
recess 140. FIG. 8 illustrates lower housing 134 which includes base 
portion 142 and side walls 144a and 144b. An upstanding flange or clip 
stop 146 is provided at the distal portion of lower housing 134. 
Referring now to FIG. 9, upper housing 132 is connected to lower housing 
134 and together define a semicircular cross-section. Substantially 
rectangular feed chute 148 is defined by upper housing 132 and by side 
walls 144a and 144b and base portion 142 of lower housing 134. As shown in 
FIG. 6, feed chute 148 stores a stack 150 of U-shaped surgical clips 152 
therein, including a distalmost surgical clip 152a. Surgical clip stack 
150 is configured such that legs 154c of surgical clip 152c are 
substantially in contact with the crown portion 156b of the next distal 
surgical clip 152b. The stack 150 of surgical clips 152 is urged towards 
the distal portion of feed chute 148 by clip follower 158 which is biased 
distally by follower spring 160 positioned in recess 140 of upper housing 
132. The proximal end of spring 160 is retained by retainer block 162 
disposed adjacent flange 164 of lower housing 134. Clip stop 146 inhibits 
a distalmost surgical clip 152a from moving into the jaw assembly 18 by 
contacting the crown portion 156a of surgical clip 152a. 
Clip pusher 136 slides along groove 138 formed on an upper surface of upper 
housing 132. During a portion of the closing stroke of movable handle 14, 
clip pusher 136 is distally advanced by thrust bar 72, as will be 
described below. Clip pusher 136 is biased proximally by return spring 
166. A distal end of return spring 166 is retained by retainer block 162. 
With reference to FIG. 10, the proximal end of return spring 166 surrounds 
supporting pin 168 which is retained by flange 170 in clip pusher 136. 
With reference to FIG. 11, the distal end portion of clip pusher 136 
includes an angularly depending portion 172 including a bifurcated clip 
engaging portion 174 having a leading edge 176 and a sloping trailing edge 
177. 
Turning now to FIG. 12, the various components of clip advancement 
subassembly 130 are illustrated in combination. In particular, upper 
housing 132 and lower housing 134 are assembled. Clip pusher 136 is 
slidably mounted on upper housing 132 and biased proximally by return 
spring 166. 
FIG. 12A illustrates in enlarged form the position of distalmost surgical 
clip 152a at the distal end of feed chute 148. Legs 154a of surgical clip 
152a are stabilized by side walls 144a and 144b, and crown 156a is 
supported by clip stop 146. Angularly depending portion 172 of clip pusher 
136 extends into feed chute 148. Leading edge 176 of clip engaging portion 
174 is configured to contact crown 156a of surgical clip 152a to advance 
the clip beyond clip stop 146 as will be described below. 
With reference to FIG. 13 in conjunction with FIG. 14, nosepiece 178 
includes a pair of proximally extending members 180a and 180b defining a 
longitudinal slot 182 therebetween to direct angularly depending portion 
216 of clip pusher 140. A pair of resilient tabs 184a and 184b are mounted 
on the bottom portion of nosepiece 178 to apply a downward force on jaw 
portions 24a and 24b to provide positive engagement of the jaw portions 
with camming structures 98 and 100 on thrust bar 72. 
Method of Assembly 
Having thus described the internal components and/or subassemblies of 
instrument 10, the method of assembly will now be described. With 
reference to FIG. 20, endoscopic portion 20 is assembled from the 
previously described components. 
Jaw assembly 18 is positioned adjacent distal portion 96 of thrust bar 72 
such that position tabs 90a and 90b are disposed within channel structure 
98. 
At the distal portion of clip advancement subassembly 130, nosepiece 178 is 
positioned adjacent lower housing 134 such that angularly depending 
portion 172 of clip pusher 136 is slidable within slot 182. 
with reference to FIG. 15 in conjunction with FIG. 16, assembly of clip 
advancement subassembly 130 and thrust bar 72 will now be described. Base 
portion 142 of lower housing 134 is configured to rest partially on 
hemispherical portion 128 of thrust bar 72 and partially on jaw assembly 
18. Longitudinal slot 186 at a proximal portion of clip pusher 136 is 
positioned in interlocking arrangement with trip lever assembly 112. 
With continued reference to FIG. 15, a substantially cylindrical profile is 
defined by the combination of thrust bar 72, and clip advancement 
subassembly 130. Outer sleeve 188 is provided defining a cylindrical 
internal passage 190 therethrough having a circular cross-section. 
Internal passage 190 is sized to receive the assembled components 
described above, which are inserted into the distal end portion 192 of 
outer sleeve 188. Apertures 194a, 194b, 194c, and 194d at distal portion 
192 of outer sleeve 188 are configured to receive tabs 88a, 88b, 88c, and 
88d of jaw assembly 18 in snap-fitting arrangement. 
Turning now to FIGS. 17 and 18, the assembly of endoscopic portion 20 and 
handle portion 12 will now be described. Bifurcated distal portion 68 of 
pusher plate 36 is connected to a proximal mounting portion 197 of thrust 
bar 72. In particular, annular notch 196, is configured to be received by 
prongs 70a and 70b for angular rotation of thrust bar 72 with respect to 
pusher plate 36. Rotation knob (not shown) is slidable over this junction 
to prevent separation of the thrust bar 72 from pusher plate 36. 
Overall Operation of Instrument 
Having thus described the internal components and assembly of instrument 
10, the operation of the instrument will now be described. With reference 
to FIGS. 19 and 20, instrument 10 is initially disposed with movable 
handle 14 in the open or "at-rest" position. As illustrated in FIGS. 
21-22, position tabs 90a and 90b of jaw assembly 18 are disposed in 
channel structure 98, and more particularly in distal zone 104. Position 
tabs 90a and 90b are freely movable within the distal zone 104 as 
indicated by arm "B". Consequently, jaw portions 24a and 24b are freely 
movable between the spaced and the approximated positions. To facilitate 
insertion of jaw assembly 18 and endoscopic body portion 20 into a small 
diameter cannula, e.g., a 5 mm diameter cannula, jaw portions 24a and 24b 
may be manually approximated such that the jaw assembly 18 does not extend 
beyond the diameter of the outer sleeve 188, e.g., by the surgeon's 
fingers or by contact with the inner geometry of the 5 mm cannula. Movable 
handle 14 is maintained in the "at-rest" position during insertion of body 
portion 20 and jaw assembly 18 through the cannula. 
When the surgeon has placed the jaw assembly 18 adjacent the surgical site, 
a single closing stroke of movable handle 14 towards stationary handle 16 
is sufficient to first deploy and/or ensure that the jaw portions 24a and 
24b are in a spaced apart position adjacent or around the tissue or 
structure to be crimped, to sequentially advance a clip to the 
spaced-apart jaw portions, to reposition the clip-containing jaw portions, 
as desired, and to finally deform the clip on the desired structure. 
Closure from the "at-rest" position of movable handle 14 to a first 
intermediate position constitutes an initial throw thereof. Secondly, 
closure from the first intermediate position to a second intermediate 
position constitutes an intermediate throw. Finally, closure from the 
second intermediate position to the closed position constitutes a final 
throw. 
During the initial throw of handle 14, the position of handle 14 is 
intermediate to that shown in FIG. 19 and FIG. 23. Thrust bar 72 moves 
distally, and position tabs 90a and 90b begin to contact distal nose 
portion 103 of center block 108. Consequently, position tabs 90a and 90b 
are sequentially conveyed into parallel channels 106a and 106b, 
respectively. Simultaneously, jaw portions are moved to the spaced apart 
position for reception of a surgical clip 152a. 
The beginning of the intermediate throw is shown in FIGS. 23-30. As 
illustrated in FIG. 24, pawl 58 is in engagement with rack 54. With 
reference to FIG. 25, clip pusher 136 moves distally with thrust bar 72 
due to locking engagement of distal tab 122 of trip lever 114 with slot 
186 of clip pusher 136. FIG. 26 depicts clip follower 158 in biased 
relationship with the stack 150 of surgical clips 152. 
In FIGS. 27-28, clip engaging portion 174 advances the crown 156a of the 
distalmost surgical clip 152a distally to overcome the restraining force 
of clip stop 146. Clip camming surface 198 contacts crown 156a and directs 
legs 154a of surgical clip 152a into channels 84a and 84b on the inner 
surfaces of jaw portions 24a and 24b. 
FIGS. 29 and 30 show position tabs 90a and 90b ride in parallel channels 
106a and 106b. Due to interposition of center block 102 between position 
tabs 90a and 90b, jaw portions 24a and 24b are maintained and controlled 
in the spaced apart position against opening or closure. In addition, the 
spacing of jaw portions 24a and 24b is selected such that a tight 
frictional grip is created between jaw portions 24a and 24b and surgical 
clip 152a to prevent surgical clip 152a from falling out of the jaw 
portions. 
Referring to FIGS. 31-37, the operation of the end portion of the 
intermediate stroke will now be described. As illustrated in FIG. 32, 
movable handle 14 continues to advance pusher plate 36 distally. Pawl 58 
is engaged with the ratchet teeth 56 on rack 54 to index advancement of 
thrust bar 72 and to prevent distal movement thereof during clip 
advancement. As illustrated in FIG. 33, clip engaging portion 174 has 
advanced surgical clip 152a into channels 84a and 84b in the jaw portions. 
Referring to FIG. 34, thrust bar 72 advances trip lever 114 such that 
proximal tab 200 contacts protrusion 202 on outer sleeve 188 (See, FIG. 
35). As illustrated in FIG. 36, trip lever 114 pivots about pin 118 in the 
direction of arrow "C" against the bias of spring 124, and distal tab 122 
moves downward and out of slot 186 in clip pusher 136. With reference to 
FIG. 37, clip pusher 136 returns proximally in the direction of arrow "P" 
due to the bias of return spring 166. The resilience of angled portion 172 
and the shallow slope of trailing edge 177 enable clip engaging portion 
174 to ride over crown 156b of the next surgical clip 152b. 
With reference to FIG. 38 in conjunction with FIG. 39, handle 14 is moved 
through the final throw towards the closed position. As illustrated in 
FIGS. 40-41, position tabs 90a and 90b pass from the parallel channels 
106a and 106b to the proximal zone 108, in which jaw portions 24a and 24b 
are freely movable. Camming surfaces 110a and 110b on jaw closure 
structure 100 at the distal portion 96 of thrust bar 72 begin to engage 
raised camming surfaces 92a and 92b on jaw portions 24a and 24b. As 
illustrated in FIGS. 42-43, jaw portions 24a and 24b are gradually brought 
into approximation with distal movement of thrust bar 72. In particular, 
raised camming surfaces 92a and 92b are wider at the distal portion than 
at the proximal portion. Therefore, progressive movement of V-shaped jaw 
closure structure 100 cams jaw portions 24a and 24b closed. The proximity 
of jaw closure structure 100 and camming surfaces 92a and 92b to the 
distal portion of jaw portions 24a and 24b enables sufficient force to be 
exerted on jaw portions 24a and 24b to deform clip 152 and compress blood 
vessels or other body tissue surrounded thereby. 
A Second Preferred Embodiment of the Subject Instrument 
Turning now to FIGS. 44-49, another preferred embodiment of the clip 
applying instrument is disclosed at reference numeral 300. Instrument 300 
operates substantially as described above with regard to instrument 10, 
with the differences described hereinbelow. In particular, FIG. 44 
illustrates channel structure 302 disposed on thrust bar 304. Channel 
structure 302 includes raised center block 306 having a distal ridge 
portion 308 integral with thrust bar 304. In contrast to the channel 
structure 98 of instrument 10, the structure of distal ridge portion 308 
is interposed in the space defined by distal zone 104 of instrument 10. A 
pair of channels 310a and 310b are defined surrounding center block 306 
and proximal cavity or zone 312 is disposed proximal of center block 306. 
Channels 310a and 310b include distal angled channels 314a and 314b and 
longitudinally elongated parallel channels 316a and 316b. 
Referring to FIG. 45, jaw assembly 318 includes elongated shank portions 
320a and 320b having position tabs 322a and 322b. Position tabs 322a and 
322b ride in channels 310a and 310b to control spacing of jaw portions 24a 
and 24b. When movable handle 14 is disposed in the "at-rest" position, 
position tabs 322a and 322b are positioned at the distal end of angled 
channels 314a and 314b. In this configuration, jaw portions 24a and 24b 
are restrained in an approximated position against opening for insertion 
through a cannula. In contrast with the channel structure 98 of instrument 
10, the interposition of distal ridge structure 308 between position tabs 
322a and 322b prevents movement of jaw portions 24a and 24b to the spaced 
apart position. Upon further closure of movable handle 14, thrust bar 304 
is displaced distally and position tabs 322a and 322b traverse angled 
channels 314a and 314b. Jaw portions 24a and 24b are thereby cammed to the 
spaced apart configuration. Upon further closure of movable handle 14, 
position tabs 322a and 322b move within parallel channels 316a and 316b. 
The spacing of jaw portions 24a and 24b is therefore maintained against 
closure or opening. 
With reference to FIGS. 46-49, clip pusher 324 is biased proximally by 
return spring 186 as described above with respect to instrument 10. Clip 
pusher 324 includes a trip lever 326 disposed thereon for interlocking 
with thrust bar 304. This contrasts with instrument 10, wherein trip lever 
114 is disposed on thrust bar 72. Trip lever 326 is normally biased by 
leaf spring 328 such that proximal tab 330 extends downward. A protrusion 
332 is formed on thrust bar 304 to contact proximal tab 320. As 
illustrated in FIG. 46, protrusion 332 is spaced from trip lever 326 
during the initial throw of movable handle 14. This configuration permits 
jaw portions 24a and 24b to be cammed open before a surgical clip is 
advanced into the jaw portions. Referring to FIG. 47, when jaw portions 
24a and 24b are in the spaced-apart or open configuration, protrusion 332 
on thrust bar 304 contacts downwardly extending trip lever 326 to advance 
clip pusher 324 with thrust bar 304. 
As illustrated in FIG. 48, trip lever 326 contacts camming tab 334 disposed 
on outer tube 336 when clip pusher 324 has advanced the surgical clip into 
jaw portions 24a and 24b. Camming tab 334 pivots trip lever 326 against 
the bias of leaf spring 328 as shown by arrow "D". Proximal tab 320 moves 
upward and out of engagement with protrusion 332 on thrust bar 304. 
Consequently, FIG. 49 illustrates that return spring 166 moves clip pusher 
324 proximally to permit closure of the jaw portions 24a and 24b to deform 
the clip. 
It will be understood that various modifications may be made to the 
embodiments shown herein. For example, the jaw assembly and endoscopic 
portions may be sized to be accommodated in cannula assemblies of various 
sizes. Therefore, the above description should not be construed as 
limiting, but merely as exemplifications as preferred embodiments. Those 
skilled in the art will envision other modifications within the scope and 
spirit of the claims appended hereto.