Patent Publication Number: US-10786263-B2

Title: Endoscopic reposable surgical clip applier

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/545,508 filed Aug. 15, 2017, the entire disclosure of which is incorporated by reference herein. 
    
    
     BACKGROUND 
     Technical Field 
     This disclosure relates to surgical clip appliers. More particularly, the present disclosure relates to endoscopic reposable surgical clip appliers having a reusable handle assembly, at least one reusable shaft assembly, and at least one disposable clip cartridge assembly. 
     Description of Related Art 
     Endoscopic surgical clip appliers are used for a number of distinct and useful surgical procedures. In the case of a laparoscopic surgical procedure, access to the interior of an abdomen is achieved through narrow 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, a tube or cannula device is extended into the patient&#39;s body through the entrance incision to provide an access port. The port allows the surgeon to insert a number of different surgical instruments therethrough using a trocar and for performing surgical procedures far removed from the incision. 
     During a majority of these procedures, the surgeon must often terminate the flow of blood or another fluid through one or more vessels. The surgeon will often use a particular endoscopic surgical clip applier to apply a surgical clip to a blood vessel or another duct to prevent the flow of body fluids therethrough during the procedure. 
     Endoscopic surgical clip appliers having various sizes (e.g., diameters), that are configured to apply a variety of diverse surgical clips, are known in the art, and which are capable of applying a single or multiple surgical clips during an entry to the body cavity. Such surgical clips are typically fabricated from a biocompatible material and are usually compressed over a vessel. Once applied to the vessel, the compressed surgical clip terminates the flow of fluid therethrough. 
     During endoscopic or laparoscopic procedures it may be desirable and/or necessary to use different size surgical clips or different configured surgical clips depending on the underlying tissue or vessels to be ligated. In order to reduce overall costs of an endoscopic surgical clip applier, it is desirable for a single endoscopic surgical clip applier to be loadable with and capable of firing different size surgical clips as needed. 
     Accordingly, a need exists for endoscopic surgical clip appliers that include reusable handle assemblies, reusable shaft assemblies, and disposable clip cartridge assemblies, with each clip cartridge assembly being loaded with a particularly sized clip (e.g., relatively small, relatively medium, or relatively large). 
     SUMMARY 
     The present disclosure relates to reposable endoscopic surgical clip appliers. 
     According to an aspect of the present disclosure, a hub assembly for use with an endoscopic assembly of a reposable surgical clip applier is provided. The hub assembly includes an outer housing defining proximal and distal end surfaces which define a channel therethrough, a driver gear slidably supported within the channel, a transmission gear slidably and rotatably supported within the channel, and a display gear slidably and rotatably supported within the channel. Each of the driver gear, transmission gear, and display gear is configured for reciprocal movement within the channel. Distal advancement of the driver gear causes a corresponding distal advancement of the transmission gear and distal advancement of the transmission gear causes a corresponding distal advancement of the display gear. The transmission gear is caused to be rotated in a first direction during each distal advancement of the driver gear and the display gear is caused to be rotated in a second direction during a predetermined distal advancement of the transmission gear. 
     In aspects, a portion of the channel may define a pair of opposed bosses having an upper portion and a lower portion. 
     In certain aspects, the driver gear may define a plurality of teeth on a distal portion thereof. 
     In other aspects, the transmission gear may define a plurality of teeth on a proximal portion thereof, the plurality of teeth configured to selectively engage the plurality of teeth of the driver gear to cause rotation of the transmission gear in the first direction during engagement therewith. 
     In certain aspects, the plurality of teeth of the transmission gear may be configured to engage the upper portion of the pair of opposed bosses to further rotate the transmission gear in the first direction. 
     In aspects, the transmission gear may define a pair of opposed teeth on a distal portion thereof. 
     In other aspects, the display gear may define a first plurality of teeth on a proximal portion thereof configured to engage the lower portion of the pair of opposed bosses. Engagement between the first plurality of teeth and the lower portion of the pair of opposed bosses may cause rotation of the display gear in the second direction during a predetermined proximal retraction of the display gear corresponding to the predetermined distal advancement of the transmission gear. 
     In certain aspects, the display gear may define a second plurality of teeth on the proximal portion thereof. The second plurality of teeth may be disposed radially inward of predetermined teeth of the first plurality of teeth and configured to selectively engage the pair of opposed teeth of the transmission gear. 
     In other aspects, the second plurality of teeth may define a pair of teeth corresponding to the pair of teeth of the transmission gear. 
     In certain aspects, an outer surface of the display gear may define a plurality of portions having a contrasting color. 
     In aspects, the outer housing may define a plurality of windows therethrough. A greater portion of each of the plurality of portions may have a contrasting color that is visible through each window of the plurality of windows after each predetermined distal advancement of the transmission gear. 
     In certain aspects, each engagement of the plurality of teeth of the driver gear with the plurality of teeth of the transmission gear may cause the transmission gear to rotate 1/24 th  of a rotation in the first direction. 
     In aspects, each engagement of the plurality of teeth of the transmission gear with the upper portion of the pair of opposed bosses may cause the transmission gear to rotate a further 1/24 th  of a rotation in the first direction. 
     In other aspects, predetermined distal advancement of the transmission gear may correspond to ½ of a rotation of the transmission gear. 
     In aspects, the display gear may be configured to rotate 1/24 th  of a rotation in the second direction during engagement of the second plurality of teeth of the display gear with the pair of opposed teeth of the transmission gear. 
     In certain aspects, the first plurality of teeth of the display gear may engage the lower portion of the pair of opposed bosses during proximal translation thereof after the predetermined distal advancement of the transmission gear. Engagement of the first plurality of teeth of the display gear and the lower portion of the pair of opposed bosses may cause the display gear to rotate a further 1/24 th  of a rotation in the second direction. 
     In other aspects, the hub assembly may further include a display gear biasing element interposed between a distal surface of the display gear and a proximal facing surface defined by the channel. The display gear biasing element may be configured to bias the display gear in a proximal direction. 
     In certain aspects, the hub assembly may further include a spindle translatably supported within the channel. The spindle may be in selective communication with the driver gear. 
     In aspects, the hub assembly may further include an overstroke mechanism disposed within a distal portion of the channel. 
     In certain aspects, the overstroke mechanism may be in mechanical communication with the spindle. The overstroke mechanism may be configured to permit an overextension of the spindle and inhibit damage to a pair of jaws associated with the endoscopic assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A particular embodiment of a surgical clip applier is disclosed herein with reference to the drawings wherein: 
         FIG. 1  is a perspective view of a reposable endoscopic surgical clip applier, according to the present disclosure including a reusable handle assembly, and a first endoscopic assembly and a second endoscopic assembly each selectively connectable to the handle assembly; 
         FIG. 2  is perspective view of the reposable endoscopic surgical clip applier including the reusable handle assembly and the first endoscopic assembly connected thereto; 
         FIG. 3  is a perspective view of the handle assembly with at least a housing half-section removed therefrom; 
         FIG. 4  is a perspective view, with parts separated, of the handle assembly of  FIGS. 1-3 ; 
         FIG. 5  is an enlarged perspective view of the indicated area of detail of  FIG. 4 , illustrating a pawl switch and a pawl actuator of the handle assembly of  FIG. 1 ; 
         FIG. 6  is a further perspective view of the pawl switch of  FIG. 5 ; 
         FIG. 7  is a further perspective view of the pawl actuator of  FIG. 5 ; 
         FIGS. 8-9  are various perspective views of the pawl switch and the pawl actuator of the handle assembly, shown in operation with the pawl switch in an un-actuated condition and the pawl actuator engaged with a pawl of a ratchet assembly; 
         FIG. 10  is a top plan view of the pawl switch and the pawl actuator of the handle assembly, shown in operation with the pawl switch in the un-actuated condition and the pawl actuator engaged from the pawl of the ratchet assembly; 
         FIG. 11  is a transverse, cross-sectional view of the handle assembly of  FIG. 1  as taken through  11 - 11  of  FIG. 1 , illustrating the pawl switch in an actuated condition; 
         FIGS. 12-13  are various perspective views of the pawl switch and the pawl actuator of the handle assembly, shown in operation with the pawl switch in the actuated condition and the pawl actuator disengaged from the pawl of the ratchet assembly; 
         FIG. 14  is a top plan view of the pawl switch and the pawl actuator of the handle assembly, shown in operation with the pawl switch in the actuated condition and the pawl actuator disengaged from the pawl of the ratchet assembly; 
         FIG. 15  is a perspective view, with parts separated, of the first endoscopic assembly of  FIG. 1 ; 
         FIG. 16  is a top, plan view of the first endoscopic assembly of  FIGS. 1 and 15 ; 
         FIG. 17  is a transverse, cross-sectional view of the first endoscopic assembly of  FIGS. 1 and 15-16 , as taken through  17 - 17  of  FIG. 16 ; 
         FIG. 18  is a perspective view illustrating an initial connection of the handle assembly and the first endoscopic assembly; 
         FIG. 19  is a longitudinal, transverse cross-sectional view illustrating the initial connection of the handle assembly and the first endoscopic assembly; 
         FIG. 20  is an enlarged view of the indicated area of detail of  FIG. 19 ; 
         FIG. 21  is a longitudinal, transverse cross-sectional view illustrating a complete connection of the handle assembly and the first endoscopic assembly; 
         FIG. 22  is an enlarged view of the indicated area of detail of  FIG. 21 ; 
         FIG. 23  is a longitudinal, transverse cross-sectional view illustrating an initial actuation of the handle assembly with the first endoscopic assembly connected thereto; 
         FIG. 24  is an enlarged view of the indicated area of detail of  FIG. 23 ; 
         FIG. 25  is a longitudinal, transverse cross-sectional view illustrating a complete actuation of the handle assembly with the first endoscopic assembly connected thereto; 
         FIG. 26  is perspective view of the reposable endoscopic surgical clip applier including the reusable handle assembly and the second endoscopic assembly connected thereto; 
         FIG. 27  is a perspective view, with parts separated, of the second endoscopic assembly of  FIGS. 1 and 26 ; 
         FIG. 28  is a perspective view, with parts separated, of a shaft assembly of the second endoscopic assembly; 
         FIG. 29  is a perspective view of the distal end of the shaft assembly of the second endoscopic assembly with an outer tube removed therefrom; 
         FIG. 30  is an enlarged view of the indicated area of detail of  FIG. 29 ; 
         FIG. 31  is an enlarged view of the indicated area of detail of  FIG. 29 ; 
         FIG. 32  is a perspective view of the distal end of the shaft assembly of the second endoscopic assembly with the outer tube and a pusher bar removed therefrom; 
         FIG. 33  is an enlarged view of the indicated area of detail of  FIG. 32 ; 
         FIG. 34  is an enlarged view of the indicated area of detail of  FIG. 32 ; 
         FIG. 35  is a perspective view of the distal end of the shaft assembly of the second endoscopic assembly with the outer tube, the pusher bar and a clip channel removed therefrom; 
         FIG. 36  is an enlarged view of the indicated area of detail of  FIG. 35 ; 
         FIG. 37  is an enlarged view of the indicated area of detail of  FIG. 35 ; 
         FIG. 38  is a perspective view of the distal end of the shaft assembly of the second endoscopic assembly with the outer tube, the pusher bar, the clip channel and a pair of jaws and a filler component removed therefrom; 
         FIG. 39  is a perspective view of the distal end of the shaft assembly of the second endoscopic assembly with the outer tube, the pusher bar, the clip channel, the pair of jaws, the filler component, and a wedge plate removed therefrom; 
         FIG. 40  is a longitudinal, transverse cross-sectional view illustrating a complete connection of the handle assembly and the second endoscopic assembly, prior to actuation of a trigger of the handle assembly; 
         FIG. 41  is a longitudinal, transverse cross-sectional view illustrating a complete actuation of the handle assembly with the second endoscopic assembly connected thereto; 
         FIG. 42  is a perspective view of another embodiment of an endoscopic assembly provided in accordance with the present disclosure; 
         FIG. 43  is a longitudinal, cross-sectional view of the endoscopic assembly of  FIG. 42 , as taken through  43 - 43  of  FIG. 42 ; 
         FIG. 44  is a perspective view, with parts separated of the endoscopic assembly of  FIG. 42 ; 
         FIG. 45  is a longitudinal, cross-sectional view of an outer housing of the endoscopic assembly of  FIG. 42 ; 
         FIG. 46  is a perspective view of a cartridge cylinder of the endoscopic assembly of  FIG. 42 ; 
         FIG. 47  is a perspective view of a spindle of the endoscopic assembly of  FIG. 42 ; 
         FIG. 48  is a perspective view of a display gear of the endoscopic assembly of  FIG. 42 ; 
         FIG. 48A  is a longitudinal, cross-sectional view of the display gear of  FIG. 48 ; 
         FIG. 49  is a rear view of the display gear of  FIG. 48 ; 
         FIG. 50  is a perspective view of a transmission gear of the endoscopic assembly of  FIG. 42 ; 
         FIG. 51  is a rear view of the transmission gear of  FIG. 50 ; 
         FIG. 52  is a side view of a driver gear of the endoscopic assembly of  FIG. 42 ; 
         FIG. 52A  is a longitudinal, cross-sectional view of the driver gear of  FIG. 52 ; 
         FIG. 53A  is a front view of a lockout spring of the endoscopic assembly of  FIG. 42 ; 
         FIG. 53B  is a perspective view of the lockout spring of  FIG. 53A ; 
         FIG. 54  is a longitudinal, cross-sectional view of the endoscopic assembly of  FIG. 42 , shown in a partially actuated position; 
         FIG. 55  is a longitudinal, cross-sectional view of the endoscopic assembly of  FIG. 42 , shown with the driver gear of  FIG. 52  engaged with the transmission gear of  FIG. 50 ; 
         FIG. 56  is a longitudinal, cross-sectional view of the endoscopic assembly of  FIG. 42 , shown in a fully retracted position; 
         FIG. 57  is perspective, cross-sectional view of the endoscopic assembly of  FIG. 42 , shown with the transmission gear of  FIG. 50  engaging a portion of the outer housing of  FIG. 45 ; 
         FIG. 58  is a longitudinal, cross-sectional view of the endoscopic assembly of  FIG. 42 , shown with the driver gear of  FIG. 52  and the transmission gear of  FIG. 50  in a partially actuated position; 
         FIG. 59  is a perspective, cross-sectional view of the endoscopic assembly of  FIG. 42 , shown with the transmission gear of  FIG. 50  partially engaging the display gear of  FIG. 48 ; 
         FIG. 60  is a longitudinal, cross-sectional view of the endoscopic assembly of  FIG. 42 , shown with the display gear of  FIG. 48  engaging a portion of the outer housing of  FIG. 45 ; 
         FIG. 61A  is a side view of the endoscopic assembly of  FIG. 42  shown with a portion of a shaded region of the display gear of  FIG. 48  visible; 
         FIG. 61B  is a side view of the endoscopic assembly of  FIG. 42  shown with a greater portion of the shaded region of the display gear of  FIG. 48  visible; 
         FIG. 62  is a perspective, cross-sectional view of the endoscopic assembly of  FIG. 42  showing the lockout spring of  FIG. 53A  engaging a portion of the spindle of  FIG. 47 ; 
         FIG. 63  is a perspective view with parts separated of an overstroke mechanism for use with the endoscopic assembly of  FIG. 42 ; 
         FIG. 64A  is a side view of the overstroke mechanism of  FIG. 63 ; 
         FIG. 64B  is a longitudinal, cross-sectional view of the overstroke mechanism of  FIG. 63  shown in an initial, unactuated position; 
         FIG. 64C  is a longitudinal, cross-sectional view of the overstroke mechanism of  FIG. 63  shown in a partially actuated position; 
         FIG. 64D  is a longitudinal, cross-sectional view of the overstroke mechanism of  FIG. 63  shown in a fully actuated position; 
         FIG. 64E  is a side view of the overstroke mechanism of  FIG. 63  shown in a fully actuated position; and 
         FIG. 65  is a schematic illustration of a robotic surgical system configured for use in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Embodiments of reposable endoscopic surgical clip appliers, 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  FIGS. 1-29 , an endoscopic surgical clip applier in accordance with an embodiment of the present disclosure, and assembly in a particular configuration, is generally designated as  10 . Surgical clip applier  10  generally includes a reusable handle assembly or actuation assembly  100 , at least one disposable or reusable endoscopic assembly  200  selectively connectable to and extendable distally from handle assembly  100 ; and optionally at least one disposable surgical clip cartridge assembly (not shown) selectively loadable into a shaft assembly of a respective endoscopic assembly  200 . 
     Briefly, the shaft assembly of endoscopic assembly  200  may have various outer diameters such as, for example, about 5 mm or about 10 mm, depending on intended use. Further, the shaft assembly may have various relatively elongated or shortened lengths depending on intended use, such as, for example, in bariatric surgery. In one embodiment, in bariatric surgery, the shaft assembly may have a length of between about 30 cm and about 40 cm. Further, the shaft assembly may be configured to fire and form a specific type of surgical clip, either individually or multiply. However one skilled in the art should appreciate that the shaft assembly may have any length in excess of about 30 cm and the present disclosure is not limited to any of the above identified lengths. 
     In accordance with the present disclosure, as will be discussed in greater detail below, an endoscopic assembly or a surgical clip cartridge assembly (not shown) may be loaded with a particularly sized set of surgical clips (e.g., relatively small surgical clips, relatively medium surgical clips, or relatively large surgical clips). It is contemplated that clip cartridge assemblies may be configured to be selectively loaded into the shaft assembly of a respective endoscopic assembly  200 , and to be actuated by the same or common handle assembly  100 , to fire and form the surgical clip(s) loaded therein onto underlying tissue and/or vessels. 
     Referring now to  FIGS. 1-14 , handle assembly  100  of surgical clip applier  10  is shown and will be described. Handle assembly  100  includes a housing  102  having a first or right side half-section  102   a  and a second or left side half-section  102   b . Housing  102  of handle assembly  100  further includes or defines, as seen in  FIGS. 3 and 4 , a nose  102   c . Housing  102  of handle assembly  100  may be formed of a suitable plastic or thermoplastic material. It is further contemplated that housing  102  of handle assembly  100  may be fabricated from stainless steel of the like. 
     Handle assembly  100  includes a trigger  104  pivotably supported between right side half-section  102   a  and left side half-section  102   b  of housing  102 . Trigger  104  is biased by a biasing member  104   a  (e.g., a return spring, compression spring or torsion spring) to an un-actuated condition. Specifically, biasing member  104   a  ( FIG. 4 ) acts on a feature of trigger  104  and on a feature of housing  102  to bias or urge trigger  104  to the un-actuated condition. Trigger  104  includes a drive arm  104   b  extending therefrom. Drive arm  104   b  may be integrally formed therewith or may be separately and fixedly secured to trigger  104 . Drive arm  104   b  may define a curved, radiused or filleted upper distal surface. 
     As illustrated in  FIGS. 3, 4 and 8-14 , trigger  104  supports or is provided with at least one linear rack  152  of teeth  152   a  of a ratchet assembly  150 , as will be described in detail below. 
     With reference to  FIGS. 3, 4, 11 , handle assembly  100  includes a drive plunger  120  operatively connected to trigger  104 . Specifically, drive plunger  120  is slidably supported within housing  102  and defines a pair of opposed, axially extending slots  120   a  formed in an outer surface thereof. Slots  120   a  of drive plunger  120  are configured to slidably engage or receive opposed tabs  102   d  of housing  102 . Drive plunger  120  further defines a proximally extending trigger slot  120   b  formed in a proximal portion thereof for operatively receiving drive arm  104   b  of trigger  104 . Trigger slot  120   b  defines a distal surface or wall  120   c  against which a distal surface of drive arm  104   b  of trigger  104  contacts in order to distally advance drive plunger  120  during an actuation of trigger  104 . 
     Drive plunger  120  further includes a tooth  120   d  ( FIG. 11 ) projecting into trigger slot  120   b . Tooth  120   d  projects substantially toward trigger  104  and includes a distal surface or wall  120   d   1  (spaced proximally from distal surface or wall  120   c  of drive plunder  120 ), and a proximal, angled wall  120   d   2  tapering to a relatively smaller height in a proximal direction. 
     Drive plunger  120  additionally includes a tab or fin  120   e  projecting from a surface thereof. Tab  120   e  of drive plunger  120  may be substantially aligned or in registration with tooth  120   d  of drive plunger  120 . Tab  120   e  of drive plunger  120  may project in a direction substantially opposite to tooth  120   d  of drive plunger  120  or to trigger  104 . 
     With reference to  FIGS. 1-4 and 11 , handle assembly  100  includes an endoscopic assembly release lever  130  pivotally supported on and connected to housing  102  via a pivot pin  132 . Pivot pin  132  is supported in housing  102 . Release lever  130  includes a proximal end  130   a  extending proximally of pivot pin  132 . Proximal end  130   a  of release lever  130  includes a wall  130   c  dimensioned to extend toward a pawl switch  140  of handle assembly  100 , as will be described in greater detail below. 
     Release lever  130  includes a distal end  130   b  extending distally of pivot pin  132 . Distal end  130   b  of release lever  130  includes a catch or tooth  130   d  projecting therefrom, in a direction towards drive plunger  120 . Catch  130   d  may be located distal of drive plunger  120 . 
     A biasing member  134 , in the form of a leaf spring, may be provided which tends to bias distal end  130   b  and catch  130   d  of release lever  130  towards drive plunger  120  of handle assembly  100 , and tends to bias proximal end  130   a  of release lever  130  away from pawl switch  140 . Specifically, biasing member  134  tends to maintain catch  130   d  of release lever  130  in engagement with an engagement feature (e.g., annular channel  212   c ) of endoscopic assembly  200 , as will be described in greater detail below. 
     With reference to  FIGS. 3, 4 and 11-14 , as mentioned above, handle assembly  100  includes a ratchet assembly  150  supported within housing  102 . Ratchet assembly  150  includes, as also mentioned above, at least one linear rack  152  of teeth  152   a  supported on and projecting from trigger  104 . Ratchet assembly  150  further includes a ratchet pawl  154  pivotally connected to housing  102  by a pawl pin at a location wherein pawl  154  is in substantial operative engagement with rack  152 . Ratchet assembly  150  further includes a pawl spring  156  configured and positioned to bias pawl  154  into operative engagement with rack  152 . Pawl spring  156  functions to maintain the tooth or teeth  154   a  of pawl  154  in engagement with teeth  152   a  of rack  152 , as well as to maintain pawl  154  in a rotated or canted position. 
     Pawl  154  is engagable with rack  152  to restrict longitudinal movement of rack  152  and, in turn, trigger  104 . In use, as trigger  104  is actuated (from a fully un-actuated position), rack  152  is also moved, into engagement with pawl  154 . Rack  152  has a length which allows pawl  154  to reverse and advance back over rack  152 , when rack  152  changes between proximal or distal movement, as trigger  104  reaches a fully actuated or fully un-actuated position. The relative lengths and sizes of rack  152  of ratchet assembly  150 , trigger  104  and drive plunger  120  define a stroke length of trigger  104 , drive plunger  120  or handle assembly  100  (e.g., a “full stroke”). 
     Turning now to  FIGS. 1, 2, 4, 11 and 18 , handle assembly  100  includes a rotation knob  160  rotatably supported on nose  102   c  of housing  102 . Rotation knob  160  includes a central axial bore  160   a  having an annular array of longitudinally extending grooves  160   b  ( FIG. 18 ) formed in a surface thereof. Grooves  160   b  of rotation knob  160  function as clocking and alignment features for the connection of endoscopic assembly  200  with handle assembly  100 . Rotation knob  160  further includes a plurality of finger grip ribs  160   c  projecting from an outer surface thereof. 
     With reference to  FIGS. 3 and 4-14 , handle assembly  100  further includes a pawl switch  140  and a pawl actuator  142  each pivotally supported in housing  102 . Pawl switch  140  is operatively connected to pawl actuator  142  and is operable to selectively move pawl actuator  142  into or out of engagement with pawl spring  156 , and in turn pawl  154 , of ratchet assembly  150  whereby pawl  154  may be selectively engaged by pawl spring  156 . In this manner, when pawl  154  is moved out of engagement with pawl spring  156 , trigger  104  is free to open and close as needed due to pawl  154  having minimal blocking effect on rack  152  of ratchet assembly  150 . As such, trigger  104  may be partially actuated (without having to be fully actuated), and may be returnable to a fully un-actuated position. Such a feature permits the user to partially squeeze or actuate trigger  104  for performing a cholangiogram procedure or the like. 
     Pawl switch  140  includes a finger lever  140   a  projecting from housing  102 , whereby pawl switch  140  may be actuated by a finger of a user. Housing  102  of handle assembly  100  may be provided with guard walls  102   d  disposed on opposed sides of finger lever  140   a  in order to inhibit inadvertent actuation of pawl switch  140 . Pawl switch  140  is movable, upon actuation of finger lever  140   a , between a first position in which ratchet assembly  150  is “on” or “activated”, and a second position in which ratchet assembly  150  is “off” or “de-activated.” It is contemplated that pawl switch  140 , and in turn ratchet assembly  150 , default to the first position. 
     Pawl switch  140  further includes a first flange  140   b  projecting a first distance from a pivot point thereof, and a second flange  140   c  projecting a second distance from the pivot point thereof, wherein the projection of the second flange  140   c  is greater than the projection of the first flange  140   b . First flange  140   b  of pawl switch  140  is selectively engagable by wall  130   c  of proximal end  130   a  of release lever  130 . In this manner, each time an endoscopic assembly  200  is attached to handle assembly  100 , and release lever  130  is actuated, wall  130   c  of release lever  130  engages first flange  140   b  of pawl switch  140  to move pawl switch to the first position ( FIGS. 19-22 ). 
     Pawl switch  140  also includes a ramp or camming surface  140   d  projecting therefrom which selectively engages a tab or finger  142   a  of pawl actuator  142  to slidably move pawl actuator  142 , and in turn pawl spring  156 , into and out of operative engagement/registration with/from pawl  154 . 
     Pawl actuator  142  is pivotally connected to housing  102  and operatively connected to pawl switch  140  such that actuation of pawl switch  140  actuates pawl actuator  142 . Pawl actuator  142  is slidably supported on a pair of support pins  143   a ,  143   b , and a biasing member  144  is provided to bias pawl actuator  142  against pawl switch  140 . In operation, with reference to  FIGS. 11-14 , when pawl switch  140  is actuated to the second position, ramp or camming surface  140   d  of pawl switch  140  acts on tab  142   a  of pawl actuator  142  to transversely slide pawl actuator  142  along support pins  143   a ,  143   b  and move pawl spring  156  out of operative engagement/registration with pawl  154 , thereby disabling the operability of ratchet assembly  150 . Also, as pawl actuator  142  is slid transversely along support pins  143   a ,  143   b , pawl actuator  142  biases biasing member  144 . 
     Further in operation, with reference to  FIGS. 8-10 , when pawl switch  140  is actuated to the first position, ramp or camming surface  140   d  of pawl switch  140  is moved to permit biasing member  144  to expand and transversely slide pawl actuator  142  along support pins  143   a ,  143   b , whereby pawl spring  156  is moved back into operative engagement/registration with pawl  154 , thereby enabling or re-enabling the operability of ratchet assembly  150 . 
     Turning now to  FIGS. 1, 2, 16 and 17 , an embodiment of an endoscopic assembly  200 , of surgical clip applier  10 , is shown and described. Endoscopic assembly  200  includes a hub assembly  210 , a shaft assembly  220  extending from hub assembly  210 , and a pair of jaws  250  pivotally connected to a distal end of shaft assembly  220 . It is contemplated that endoscopic assembly  200  may be configured to close, fire or form surgical clips similar to those shown and described in U.S. Pat. No. 4,834,096, the entire content of which is incorporated herein by reference. 
     Hub assembly  210  functions as an adapter assembly which is configured for selective connection to rotation knob  160  and nose  102   c  of housing  102  of handle assembly  100 . Hub assembly  210  includes an outer housing  212  having a cylindrical outer profile. Outer housing  212  includes a first or right side half section  212   a , and a second or left side half section  212   b . Outer housing  212  of hub assembly  210  defines an outer annular channel  212   c  formed in an outer surface thereof, and at least one (or an annular array) of axially extending ribs  212   d  projecting from an outer surface thereof. Outer annular channel  212   c  of outer housing  212  of endoscopic assembly  200  is configured to receive catch  130   d  of release lever  130  of handle assembly  100  ( FIGS. 19-22 ) when endoscopic assembly  200  is coupled to handle assembly  100 . 
     Ribs  212   d  of outer housing  212  function as a clocking/alignment feature during connection of endoscopic assembly  200  and handle assembly  100  with one another, wherein ribs  212   d  of outer housing  212  of endoscopic assembly  200  are radially and axially aligned with respective grooves  160   b  of rotation knob  160  of handle assembly  100 . During connection of endoscopic assembly  200  and handle assembly  100 , ribs  212   d  of outer housing  212  of endoscopic assembly  200  are slidably received in respective grooves  160   b  of rotation knob  160  of handle assembly  100 . 
     The connection of hub assembly  210  of endoscopic assembly  200  with rotation knob  160  of handle assembly  100  enables endoscopic assembly  200  to rotate 360°, about a longitudinal axis thereof, relative to handle assembly  100 . 
     Outer housing  212  of hub assembly  210  further defines an open proximal end  212   e  configured to slidably receive a distal end of drive plunger  120  of handle assembly  100 , when endoscopic assembly  200  is coupled to handle assembly  100  and/or when surgical clip applier  10  is fired. 
     As mentioned above, endoscopic assembly  200  includes a shaft assembly  220  extending distally from hub assembly  210 . Shaft assembly  220  includes an elongate outer tube  222  having a proximal end  222   a  supported and secured to outer housing  212  of hub assembly  210 , a distal end  222   b  projecting from outer housing  212  of hub assembly  210 , and a lumen  222   c  ( FIGS. 15 and 17 ) extending longitudinally therethrough. Distal end  222   b  of outer tube  222  supports or defines an outer clevis  222   d  for pivotally supporting a pair of jaws  250 , as will be described in greater detail below. 
     Shaft assembly  220  further includes an inner shaft  224  slidably supported within lumen  222   c  of outer tube  222 . Inner shaft  224  includes a proximal end  224   a  projecting proximally from proximal end  222   a  of outer tube  222 , and a distal end  224   b  defining an inner clevis  224   c  for supporting a cam pin  224   d  which engages camming slots  252   c ,  254   c  of a pair of jaws  250 , as will be described in greater detail below. 
     With reference to  FIGS. 15 and 17 , hub assembly  210  includes a drive assembly  230  supported within outer housing  212  thereof. Drive assembly  230  includes a cartridge cylinder  232  having a cup-like configuration, wherein cartridge cylinder  232  includes an annular wall  232   a , a proximal wall  232   b  supported at and closing off a proximal end of annular wall  232   a , an open distal end  232   c , and a cavity or bore  232   d  defined therewithin. 
     Drive assembly  230  also includes a cartridge plunger  234  slidably supported within bore  232   d  of cartridge cylinder  232 . Cartridge plunger  234  is fixedly supported on inner shaft  224 , at the proximal end  224   a  thereof. Cartridge plunger  234  is sized and configured for slidable receipt within bore  232   d  of cartridge cylinder  232  of drive assembly  230 . A ring, flange or the like  235  may be fixedly supported at a distal end of bore  232   d  of cartridge cylinder  232 , through which proximal end  224   a  of cartridge plunger  234  extends and which functions to maintain cartridge plunger  234  within bore  232   d  of cartridge cylinder  232 . 
     Drive assembly  230  includes a first biasing member  236  (e.g., a compression spring) disposed within bore  232   d  of cartridge cylinder  232 . Specifically, first biasing member  236  is interposed between proximal wall  232   b  of cartridge cylinder  232  and a proximal surface of cartridge plunger  234 . First biasing member  236  has a first spring constant “K 1 ” which is relatively more firm or more stiff, as compared to a second spring constant “K 2 ” of a second biasing member  238 , as is described in detail below. 
     Drive assembly  230  further includes a second biasing member  238  (e.g., a compression spring) supported on proximal end  224   a  of inner shaft  224 . Specifically, second biasing member  238  is interposed between a proximal flange  222   d  of outer tube  222  and a distal surface of cartridge plunger  234 . Second biasing member  238  has a second spring constant “K 2 ” which is relatively less firm or less stiff, as compared to the first spring constant “K 1 ” of first biasing member  236 . 
     As illustrated in  FIGS. 15 and 17 , endoscopic assembly  200  includes a pair of jaws  250  pivotally supported in a clevis  222   d  at distal end  222   b  of outer tube  222  by a pivot pin  256 . The pair of jaws  250  includes a first jaw  252  and a second jaw  254 . Each jaw  252 ,  254  includes a respective proximal end  252   a ,  254   a , and a respective distal end  252   b ,  254   b , wherein proximal ends  252   a ,  254   a  and distal ends  252   b ,  254   b  of jaws  252 ,  254  are pivotable about pivot pin  256 . Each proximal end  252   a ,  254   a  of respective jaws  252 ,  254  defines a cam slot  252   c ,  254   c  therein which is sized and configured to receive cam pin  224   d  of inner shaft  224 . In use, as inner shaft  224  is axially displaced relative to outer shaft  222 , inner shaft  224  translated cam pin  224   d  thereof through cam slot  252   c ,  254   c  of jaws  252 ,  254  to thereby open or close the pair of jaws  250 . 
     When the pair of jaws  250  are in an open position, and a new, unformed or open surgical clip (not shown) is located or loaded within the distal ends  252   b ,  254   b  of jaws  252 ,  254  of the pair of jaws  250 , as inner shaft  224  is moved distally relative to outer shaft  222 , cam pin  224   d  is translated through cam slots  252   c ,  254   c  of jaws  252 ,  254 . As cam pin  224   d  is translated through cam slots  252   c ,  254   c  of jaws  252 ,  254  the distal ends  252   b ,  254   b  of jaws  252 ,  254  are moved to the closed or approximated position to close and/or form the surgical clip located or loaded therewithin. 
     The dimensions of jaws  252 ,  254  and of cam slots  252   c ,  254   c  of jaws  252 ,  254  determines an overall length required to move jaws  252 ,  254  from a fully open position to a fully closed position, defining a closure stroke length of the pair of jaws  250 . 
     With reference now to  FIGS. 19-25 , an operation or firing of surgical clip applier  10 , including endoscopic assembly  200  operatively connected to handle assembly  100 , is shown and described. With endoscopic assembly  200  operatively connected to handle assembly  100 , and with a new, unformed or open surgical clip (not shown) is located or loaded within the distal ends  252   b ,  254   b  of jaws  252 ,  254  of the pair of jaws  250 , as trigger  104  of handle assembly  100  is actuated drive bar  104   b  of trigger  104  acts on drive plunger  120  to distally advance drive plunger  120 . As trigger  104  is actuated, pawl  154  of ratchet assembly  150  begins to engage rack  152  thereof. With pawl  154  engaged with rack  152 , trigger  104  may not return to a fully unactuated position until trigger  104  completes a full actuation or stroke thereof. 
     As drive plunger  120  is distally advanced, a distal end of drive plunger  120  presses against proximal wall  232   b  of cartridge cylinder  232  of drive assembly  230  of endoscopic assembly  200  to distally advance cartridge cylinder  232 . Due to first spring constant “K 1 ” of first biasing member  236  being larger or greater than second spring constant “K 2 ” of second biasing member  238 , as cartridge cylinder  232  is advanced distally, cartridge cylinder  232  distally advances first biasing member  236 , which in turn acts on cartridge plunger  234  to distally advance cartridge plunger  234 . As cartridge plunger  234  is distally advanced, cartridge plunger  234  distally advances inner shaft  224  relative to outer shaft  222 . Being that second biasing member  238  is interposed between proximal flange  222   d  of outer tube  222  and distal surface of cartridge plunger  234 , as cartridge plunger  234  is distally advanced, cartridge plunger  234  also compresses second biasing member  238 . 
     As inner shaft  224  is distally advanced relative to outer shaft  222 , inner shaft  224  distally advances cam pin  224   d  through cam slot  252   c ,  254   c  of jaws  252 ,  254  to close the pair of jaws  250  and to close and/or form the surgical clip (not shown) loaded within the pair of jaws  250 . Cam pin  224   d  of inner shaft  224  is advanced distally until cam pin  224   d  reaches an end of cam slots  252   c ,  254   c  of jaws  252 ,  254  of the pair of jaws  250  and/or until the distal ends  252   b ,  254   b  of jaws  252 ,  254  of the pair of jaws  250  are fully approximated against one another (e.g., in contact with one another or fully closed on the surgical clip (not shown)), whereby cam pin  224   d  may not have reached the end of cam slots  252   c ,  254   c  of jaws  252 ,  254 . This position may be considered a hard stop of the pair of jaws  250 . The axial distance that cam pin  224   d  has traveled from a proximal-most position thereof to when cam pin  224   d  reaches the end of cam slots  252   c ,  254   c  of jaws  252 ,  254  or when the distal ends  252   b ,  254   b  of jaws  252 ,  254  of the pair of jaws  250  are fully approximated against one another, may also define the closure stroke length of the pair of jaw  250 . 
     When the pair of jaws  250  have reached the hard stop, or when the cam pin  224   d  has reached an end of the closure stroke length, pawl  154  of ratchet assembly  150  of handle assembly  100  may not have cleared rack  152  thereof, and thus blocks or prevents trigger  104  from returning to a fully unactuated position thereof. Since the pair of jaws  250  cannot close any further, and since cam pin  224   d  cannot be advanced distally any further, inner shaft  222  is also stopped from further distal advancement. However, as mentioned above, in order to return trigger  104  to the fully unactuated position, trigger  104  must first complete the full actuation stroke thereof. As such, as trigger  104  is further actuated to complete the full stroke thereof, as drive plunger  120  is continued to be driven distally, the distal end of drive plunger  120  continues to press against proximal wall  232   b  of cartridge cylinder  232  of drive assembly  230  of endoscopic assembly  200  to continue to distally advance cartridge cylinder  232 . 
     With inner shaft  222 , and in turn cartridge plunger  234 , stopped from any further distal advancement, as cartridge cylinder  232  is continued to be advanced distally, cartridge cylinder  232  begins to and continues to compress first biasing member  236  until such time that pawl  154  of ratchet assembly  150  of handle assembly  100  clears and disengages rack  152  thereof. With pawl  154  of ratchet assembly  150  clear and disengaged from rack  152 , trigger  104  may be released and returned to the fully unactuated position by hand, by a return spring  104   a  of trigger  104  and/or by first biasing member  236  and second biasing member  238  of endoscopic assembly  200 . 
     In accordance with the present disclosure, the trigger stroke length for trigger  104  of handle assembly  100  is constant or fixed, while the closure stroke length of the pair of jaws  250  may vary depending on the particular endoscopic assembly  200  connected to handle assembly  100 . For example, particular endoscopic assemblies  200  may require the pair of jaws  250  thereof to travel a relatively greater or smaller distance in order to complete a full opening and closing thereof. As such, various sized and dimensioned endoscopic assemblies, including a hub assembly in accordance with the present disclosure, substantially similar to hub assembly  210 , may be connected to the universal handle assembly  100  and be actuatable by the universal handle assembly  100 . 
     Accordingly, various endoscopic assemblies, constructed in accordance with the principles of the present disclosure, may be provided which are also capable of firing or forming or closing surgical clips of various sizes, materials, and configurations, across multiple platforms for multiple different manufactures. 
     Turning now to  FIGS. 26-29 , an endoscopic surgical clip applier, in accordance with the present disclosure, and assembly in another configuration, is generally designated as  10 ′. Surgical clip applier  10 ′ generally includes reusable handle assembly  100 , at least one disposable or reusable endoscopic assembly  400  selectively connectable to and extendable distally from handle assembly  100 ; and optionally at least one disposable surgical clip cartridge assembly (not shown) selectively loadable into a shaft assembly of a respective endoscopic assembly  400 . 
     Turning now to  FIGS. 1, 2, 16 and 17 , an embodiment of an endoscopic assembly  400 , of surgical clip applier  10 ′, is shown and described. Endoscopic assembly  400  includes a hub assembly  410 , a shaft assembly  420  extending from hub assembly  410 , and a pair of jaws  450  pivotally connected to a distal end of shaft assembly  420 . It is contemplated that endoscopic assembly  400  may be configured to close, fire or form surgical clips similar to those shown and described in U.S. Pat. No. 7,819,886 or 7,905,890, the entire contents of each of which is incorporated herein by reference. 
     Hub assembly  410  also functions as an adapter assembly which is configured for selective connection to rotation knob  160  and nose  102   c  of housing  102  of handle assembly  100 . Hub assembly  410  includes an outer housing  412  having a cylindrical outer profile. Outer housing  412  includes a first or right side half section  412   a , and a second or left side half section  412   b . Outer housing  412  of hub assembly  410  defines an outer annular channel  412   c  formed in an outer surface thereof, and at least one (or an annular array) of axially extending ribs  412   d  projecting from an outer surface thereof. Outer annular channel  412   c  of outer housing  412  of endoscopic assembly  400  is configured to receive catch  130   d  of release lever  130  of handle assembly  100  ( FIGS. 28 and 29 ) when endoscopic assembly  400  is coupled to handle assembly  100 . 
     Ribs  412   d  of outer housing  412  function as a clocking/alignment feature during connection of endoscopic assembly  400  and handle assembly  100  with one another, wherein ribs  412   d  of outer housing  412  of endoscopic assembly  400  are radially and axially aligned with respective grooves  160   b  of rotation knob  160  ( FIG. 18 ) of handle assembly  100 . During connection of endoscopic assembly  400  and handle assembly  100 , ribs  412   d  of outer housing  412  of endoscopic assembly  400  are slidably received in respective grooves  160   b  of rotation knob  160  of handle assembly  100 . 
     The connection of hub assembly  410  of endoscopic assembly  400  with rotation knob  160  of handle assembly  100  enables endoscopic assembly  400  to rotate 360°, about a longitudinal axis thereof, relative to handle assembly  100 . 
     Outer housing  412  of hub assembly  410  further defines an open proximal end  412   e  configured to slidably receive a distal end of drive plunger  120  of handle assembly  100 , when endoscopic assembly  400  is coupled to handle assembly  100  and/or when surgical clip applier  10 ′ is fired. 
     As mentioned above, endoscopic assembly  400  includes a shaft assembly  420  extending distally from hub assembly  410 . Shaft assembly  420  includes an elongate outer tube  422  having a proximal end  422   a  supported and secured to outer housing  412  of hub assembly  410 , a distal end  422   b  projecting from outer housing  412  of hub assembly  410 , and a lumen  422   c  ( FIG. 27 ) extending longitudinally therethrough. Distal end  422   b  of outer tube  422  supports a pair of jaws  450 . 
     Shaft assembly  420  further includes an inner shaft  424  slidably supported within lumen  422   c  of outer tube  422 . Inner shaft  424  includes a proximal end  424   a  projecting proximally from proximal end  422   a  of outer tube  422 , and a distal end  424   b  configured to actuate the pair of jaws  450  to form a surgical clip (not shown) that has been loaded into the pair of jaws  450 . Proximal end  424   a , as illustrated in  FIGS. 28 and 29 , may define a hook  424   c  or other translational force coupling feature. 
     With reference to  FIGS. 27-29 , hub assembly  410  includes a drive assembly  430  supported within outer housing  412  thereof. Drive assembly  430  includes a cartridge cylinder  432  having a cup-like configuration, wherein cartridge cylinder  432  includes a longitudinally split annular wall  432   a , a proximal wall  432   b  supported at and closing off a proximal end of annular wall  432   a , an open distal end  432   c , a cavity or bore  432   d  defined therewithin, and a pair of axially extending slits  432   e . Cartridge cylinder  432  includes an annular flange  432   f  provided at distal end  432   c  thereof. A ring, flange or the like  435  may be fixedly supported at a proximal end of cartridge cylinder  432 . 
     Drive assembly  430  also includes a cartridge plunger or key  434  slidably supported within bore  432   d  and within slits  432   e  of cartridge cylinder  432 . Cartridge plunger  434  is selectively connectable to proximal end  424   a  of inner shaft  424 . Cartridge plunger  434  is sized and configured for slidable receipt within slits  432   e  and bore  432   d  of cartridge cylinder  432  of drive assembly  430 . Cartridge plunger  434  includes an elongate stem or body portion  434   a  having a proximal end  434   b , and a distal end  434   c , wherein distal end  434   c  of cartridge plunger  434  is configured for selective connection to proximal end  424   a  of inner shaft  424 . Cartridge plunger  434  further includes a pair of opposed arms  434   d  supported at the proximal end  434   b  thereof and which extend in a distal direction along stem  434   a  and towards distal end  434   c . Each arm  434   d  terminates in a radially extending finger  434   e , wherein fingers  434   e  project from cartridge cylinder  432  when cartridge plunger  434  is disposed within cartridge cylinder  432 . 
     Drive assembly  430  may also include a collar  437  defining a lumen therethrough and through with inner shaft  424  and stem  434   a  of cartridge plunger  434  extend. Collar  437  includes an outer annular flange  437   a  extending therefrom. 
     Drive assembly  430  includes a first biasing member  436  (e.g., a compression spring) disposed about cartridge cylinder  432 . Specifically, first biasing member  436  is interposed between ring  435  supported on cartridge cylinder  432  and fingers  434   e  of cartridge plunger  434 . First biasing member  436  has a first spring constant “K 1 ” which is relatively more firm or more stiff, as compared to a second spring constant “K 2 ” of a second biasing member  438 , as is described in detail below. 
     Drive assembly  430  further includes a second biasing member  438  (e.g., a compression spring) supported on stem  434   a  of cartridge plunger  434  and on collar  437 . Specifically, second biasing member  438  is interposed between a flange  437   a  of collar  437  and proximal end  434   b  of cartridge plunger  434 . Second biasing member  438  has a second spring constant “K 2 ” which is relatively less firm or less stiff, as compared to the first spring constant “K 1 ” of first biasing member  436 . 
     Turning now to  FIGS. 26-41 , shaft assembly  420  of endoscopic assembly  400  includes at least a spindle  440  slidably supported in lumen  422   c  of outer tube  422 , a wedge plate  460  slidably supported within lumen  422   c  of outer tube  422  and interposed between the pair of jaws  450  and spindle  440 ; a clip channel  470  fixedly supported in lumen  422   c  of outer tube  422  and disposed adjacent the pair of jaws  450  (supported in and extending from distal end  422   b  of outer tube  422 ) on a side opposite wedge plate  460 , and a pusher bar  480  slidably supported in lumen  422   c  of outer tube  422  and being disposed adjacent clip channel  470 . 
     Spindle  440  includes a proximal end  440  defining an engagement feature (e.g., a nub or enlarged head) configured to engage a complementary engagement feature provided in distal end  424   b  of inner shaft  424 . Spindle  440  further includes a distal end  440   b  operatively connected to a jaw cam closure wedge  442  via a slider joint  444 . Jaw cam closure wedge  442  is selectively actuatable by spindle  440  to engage camming features of the pair of jaws  450  to close the pair of jaws  450  and form a surgical clip “C” loaded therewithin. 
     Slider joint  444  supports a latch member  446  for selective engagement with spindle  440 . Latch member  446  may be cammed in a direction toward spindle  440 , wherein latch member  446  extends into a corresponding slot formed in spindle  440  during actuation or translation of spindle  440 . In operation, during distal actuation spindle  400 , at a predetermined distance, latch member  446  is mechanically forced or cammed into and engage a channel of spindle  440 . This engagement of latch member  446  in the channel of spindle  440  allows slider joint  444  to move together with jaw cam closure wedge  442 . Jaw cam closure wedge  442  thus can engage the relevant surfaces of the pair of jaws  450  to close the pair of jaws  450 . 
     As illustrated in  FIGS. 28 and 39 , slider joint  444  is connected, at a proximal end  444   a  thereof, to a channel formed in spindle  440 . A distal end  444   b  of slider joint  444  defines a substantially T-shaped profile, wherein the distal end  444   b  thereof is connected to jaw cam closure wedge  442 . Latch member  446  functions as a linkage and is disposed to move through an aperture  444   c  in slider joint  444  to link with another fixed member and prevent slider joint  444  from advancing jaw cam closure wedge  442 , and thus preventing the camming of jaw cam closure wedge  442  from camming the pair of jaws  450  to a closed condition during an initial stroke of trigger  104 . 
     Spindle  440  is provided with a camming feature configured to move a cam link  448  (pivotably connected to a filler component  466 , as will be described in greater detail below) a perpendicular manner relatively to a longitudinal axis of spindle  440  during a distal advancement of spindle  440 . 
     Clip channel  470  of shaft assembly  420  slidably retains a stack of surgical clips “C” therein for application, in seriatim, to the desired tissue or vessel. A clip follower  472  is provided and slidably disposed within clip channel  470  at a location proximal of the stack of surgical clips “C”. A biasing member  474  is provided to spring bias clip follower  472 , and in turn, the stack of surgical clips “C”, distally. A clip channel cover  476  is provided that overlies clip channel  470  to retain and guide clip follower  472 , biasing member  474  and the stack of surgical clips “C” in clip channel  470 . 
     As mentioned above, shaft assembly  420  includes a pusher bar  480  for loading a distal-most surgical clip “C 1 ” of the stack of surgical clips “C” into the pair of jaws  450 . Pusher bar  480  includes a pusher  480   a  at a distal end thereof for engaging a backspan of the distal-most surgical clip “C 1 ” and urging the distal-most surgical clip “C 1 ” into the pair of jaws  450 . Pusher bar  480  includes a fin or tab  480   b  extending therefrom and extending into a slot  482   a  of a trip block  482 . Fin  480   b  of pusher bar  480  is acted upon by a biasing member (not shown) that is supported in trip block  482  to bias pusher bar  480  in a proximal direction. 
     In operation, in order for spindle  440  to advance pusher bar  480  during a distal movement thereof, spindle  440  supports a trip lever  484  and a biasing member  486  (e.g., leaf spring). During a distal movement of spindle  440 , as illustrated in  FIG. 31 , a distal nose or tip  484   a  of trip lever  484  selectively engages pusher bar  480  to distally advance pusher bar  480  and load distal-most surgical clip “C 1 ” into the pair of jaws  450 . 
     Also as mentioned above, shaft assembly  420  further includes a wedge plate  460  that is biased to a proximal position by a wedge plate spring  462 . Wedge plate  460  is a flat bar shaped member having a number of windows formed therein. Wedge plate  460  has a distal-most position wherein a tip or nose of wedge plate  460  is inserted between the pair of jaws  450  to maintain the pair of jaws  450  in an open condition for loading of the distal-most surgical clip “C 1 ” therein. Wedge plate  460  has a proximal-most position, maintained by wedge plate spring  462 , wherein the tip or nose of wedge plate  460  is retracted from between the pair of jaws  450 . 
     As illustrated in  FIGS. 28 and 38 , wedge plate  460  defines a “U” or “C” shaped aperture or window  460   b  in a side edge thereof. The “C” shaped aperture or window  460   b  of wedge plate  460  selectively engages a cam link  448  supported on a filler plate  466 . Cam link  448  selectively engages a surface of “C” shaped aperture or window  460   b  of wedge plate  460  to retain wedge plate  460  in a distal-most position such that a distal tip or nose  460   a  of wedge plate  460  is maintained inserted between the pair of jaws  450  to maintain the pair of jaws  450  splayed apart. 
     Shaft assembly  420  further includes a filler component  466  interposed between clip channel  470  and wedge plate  460 , at a location proximal of the pair of jaws  450 . Filler component  466  pivotably supports a cam link  448  that is engagable with wedge plate  460 . In operation, during a distal advancement of spindle  440 , a camming feature of spindle  440  engages a cam link boss of cam link  448  to thereby move cam link  448  out of engagement of wedge plate  460  and permit wedge plate  460  to return to the proximal-most position as a result of biasing member  462 . 
     Trip block  482  defines an angled proximal surface  482   b  for engagement with a corresponding surface of trip lever  484  that will be discussed herein. As mentioned above, notch or slot  482   a  of trip block  482  is for receipt of fin  480   b  of pusher bar  480 . In order to disengage trip lever  484  from a window  480   c  ( FIG. 31 ) of pusher bar  480 , and allow pusher bar  480  to return to a proximal-most position following loading of a surgical clip “C” into the pair of jaws  450 , angled proximal surface  482   b  trip block  482  engages trip lever  484  to cam trip lever  484  out of window  480   c  of pusher bar  480 . It is contemplated that spindle  440  may define a first cavity and a second cavity therein for receiving trip lever  484  and trip lever biasing spring  486 , respectively. The first cavity may be provided with a pivoting boss to allow trip lever  484  to pivot between a first position and a second position. Trip lever biasing spring  486  may rest in the second cavity. 
     Trip lever biasing spring  486  functions to maintain a tip of trip lever  484  in contact with pusher bar  480 , and more specifically, within window  480   c  of pusher bar  480  (FIG.  31 ) such that distal advancement of spindle  440  results in distal advancement of pusher bar  480 , which in turn results in a loading of a distal-most surgical clip “C 1 ” in the pair of jaws  450 . 
     With reference to  FIGS. 28, 33 and 36 , clip applier  10 ′ also has a lockout bar  490 . Lockout bar  490  includes a first end, and a second opposite hook end. The second hook end of lockout bar  490  is adapted to engage clip follower  472  of shaft assembly  420 . Lockout bar  490  is pivotally retained in a slot formed in clip follower  472 . Lockout bar  490  does not by itself lockout clip applier  10 ′, but instead cooperates with the ratchet mechanism  150  of handle assembly  100  to lock out clip applier  10 ′. 
     Lockout bar  490  is adapted to move distally with clip follower  472  each time clip applier  10 ′ is fired, and clip follower  472  is advanced distally. In operation, each time a surgical clip “C” is fired from clip applier  10 ′, clip follower  472  will advance distally relative to the clip channel  470 . 
     Pusher bar  480  defines a distal window therein (not shown). In operation, when clip follower  472  is positioned beneath pusher bar  480  (e.g., when there are no remaining surgical clips), a distal end  490   a  of lockout bar  490  will deflect upward (due to a biasing of a lockout biasing member  492 ), and enter a distal window  480   d  of pusher bar  480  to engage pusher bar  480  at a distal end of distal window  480   d . Further, a proximal end  490   b  of lockout bar  490 , defines a hook ( FIG. 37 ), which is rotated into and engages an aperture defined in a floor of clip channel  470 . 
     With the distal end of pusher bar  480  disposed within distal window  480   d  of pusher bar  480 , pusher bar  480 , and in turn, spindle  440  cannot return to a fully proximal position. Since spindle  440  cannot return to the fully proximal position, pawl  152  of ratchet mechanism  150  of handle assembly  100  cannot return to the home or initial position relative to rack  154  thereof. Instead, pawl  154  will remain in an intermediate position along rack  154 , thus preventing trigger  104  from returning to a fully unactuated position. 
     With continued reference to  FIGS. 26-29 , an operation or firing of surgical clip applier  10 ′, including endoscopic assembly  400  operatively connected to handle assembly  100 , is shown and described. With endoscopic assembly  400  operatively connected to handle assembly  100 , as trigger  104  of handle assembly  100  is actuated drive bar  104   b  of trigger  104  acts on drive plunger  120  to distally advance drive plunger  120 . As trigger  104  is actuated, pawl  154  of ratchet assembly  150  begins to engage rack  152  thereof. With pawl  154  engaged with rack  152 , trigger  104  may not return to a fully unactuated position until trigger  104  completes a full actuation or stroke thereof. 
     As drive plunger  120  is distally advanced, a distal end of drive plunger  120  presses against proximal wall  432   b  of cartridge cylinder  432  of drive assembly  430  of endoscopic assembly  400  to distally advance cartridge cylinder  432 . Due to first spring constant “K 1 ” of first biasing member  436  being larger or greater than second spring constant “K 2 ” of second biasing member  438 , as cartridge cylinder  432  is advanced distally, ring  435  acts on first biasing member  436  which in turn acts on fingers  434   e  of cartridge plunger  434  to push cartridge plunger  434  distally. As cartridge plunger  434  is distally advanced, cartridge plunger  434  distally advances inner shaft  424  relative to outer shaft  422 . Being that second biasing member  438  is interposed between a flange  437   a  of collar  437  and proximal end  434   b  of cartridge plunger  434 , as cartridge plunger  434  is distally advanced, cartridge plunger  434  also compresses second biasing member  438 . 
     As inner shaft  424  is distally advanced relative to outer shaft  422 , inner shaft  424  actuates a clip pusher (not shown) which in turn acts on a distal-most surgical clip (not shown) of a stack of surgical clips (not shown) to distally advance the distal-most surgical clip into the pair of jaws  450 . Following loading of the distal-most surgical clip into the pair of jaws  450 , the distal advancement of inner shaft  424  effects a closure of the pair of jaws  450  to form the surgical clip loaded therewithin. 
     When the pair of jaws  450  have fully closed to form the surgical clip loaded therein, or when the pair of jaws  450  have reached a hard stop, pawl  154  of ratchet assembly  150  of handle assembly  100  may not have cleared rack  152  thereof, and thus blocks or prevents trigger  104  from returning to a fully unactuated position thereof. Since the pair of jaws  450  cannot close any further, inner shaft  422  is also stopped from further distal advancement. However, as mentioned above, in order to return trigger  104  to the fully unactuated position, trigger  104  must first complete the full actuation stroke thereof. As such, as trigger  104  is further actuated to complete the full stroke thereof, as drive plunger  120  is continued to be driven distally, the distal end of drive plunger  120  continues to press against proximal wall  432   b  of cartridge cylinder  432  of drive assembly  430  of endoscopic assembly  400  to continue to distally advance cartridge cylinder  432 . 
     With inner shaft  422 , and in turn cartridge plunger  434 , stopped from any further distal advancement, as cartridge cylinder  432  is continued to be advanced distally relative to cartridge plunger  434 , cartridge cylinder  432  begins to and continues to compress first biasing member  436  until such time that pawl  154  of ratchet assembly  150  of handle assembly  100  clears and disengages rack  152  thereof. With pawl  154  of ratchet assembly  150  clear and disengaged from rack  152 , trigger  104  may be released and returned to the fully unactuated position by hand, by a return spring (not shown) of trigger  104  or handle assembly  100  and/or by first biasing member  436  and second biasing member  438  of endoscopic assembly  400 . 
     With reference to  FIGS. 42-53B , another embodiment of an endoscopic assembly is provided and generally identified by reference numeral  500 . The endoscopic assembly  500  is similar to the endoscopic assembly  400 , and therefore, for purposes of brevity, only the differences therebetween are described in detail hereinbelow. 
     The hub assembly  510  of the endoscopic assembly  500  includes an outer housing  512  having a generally cylindrical outer profile and includes a first or right side half section  512   a  and a second or left side half section  512   b . An outer surface of the outer housing  512  of the hub assembly  510  defines an outer annular channel  512   c  therein to receive the catch  130   d  of the release lever  130  of the handle assembly  100  ( FIGS. 28 and 29 ) when the endoscopic assembly  500  is coupled to the handle assembly  100 . 
     An inner surface  514  ( FIG. 45 ) of the outer housing  512  of the hub assembly  510  defines a channel  516  therethrough extending through proximal and distal end surfaces thereof. A proximal portion  516   a  of the channel  516  is configured to slidably receive a portion of a cartridge cylinder  520  therein. A medial portion  516   b  of the channel  516  is disposed adjacent and distal to the proximal portion  516   a . The greater width of the medial portion  516   b  defines a distal facing surface  516   c  at an intersection of the proximal portion  516   a  and the medial portion  516   b . A distal portion of the medial portion  516   b  defines an annular flange  516   d  extending radially inward and having a proximal facing surface  516   e  and an opposite, distal facing surface  516   f . The annular flange  516   d  defines a generally rectangular profile configured to slidably receive a driver gear  560  and inhibit rotation of the driver gear  560  therewithin. 
     The inner surface  514  of the outer housing  512  defines a chamber  516   g  that is disposed adjacent and distal to the annular flange  516   d . The chamber  516   g  defines a width that is greater than the annular flange  516   d  and the medial portion  516   b , although it is contemplated that the width of the chamber  516   g  may be equal to or less than the width of the medial portion  516   b . The inner surface  514  of the outer housing  512  defines a pair of opposed bosses  518  adjacent to, and extending from, the annular flange  516   d . Each boss of the pair of opposed bosses  518  defines a generally rectangular profile extending in a distal direction from the annular flange  516   d  and defining an upper portion  518   a  and a lower portion  518   b . The lower portion  518   b  extends further in a distal direction than the upper portion  518   a  and upper portion  518   a  extends radially inward a greater amount than the lower portion  518   b  such that each of the upper portion  518   a  and the lower portion  518   b  selectively engage different components of the hub assembly  510 . A distal portion of the upper portion  518   a  defines a first bevel  518   c  that is angled in a distal to proximal direction (e.g., the distal most portion is closest to a medial portion of the chamber  516   g ). A distal portion of the lower portion  518   b  defines a second bevel  518   d  that is oriented in an opposite direction than that of the first bevel, such that the first and second bevels  518   c  and  518   d  are oriented in a mirrored fashion about a longitudinal axis X-X ( FIG. 45 ) defined through the channel  516 . 
     The inner surface  514  of the outer housing  512  defines a plurality of windows  516   h  therethrough at a distal portion of the chamber  516   g . As will be described in further detail hereinbelow, the plurality of windows  516   h  enable a contrasting color  558  ( FIG. 48 ) disposed on the display gear  550  to be visible therethrough when a final surgical clip of a plurality of surgical clips has been formed. A distal end wall  516   i  of the chamber  516   g  defines a counter bore  516   j  configured to receive an over-stroke sleeve  610  ( FIG. 44 ) of an over-stroke mechanism  600 . An inner surface of the counterbore  516   j  defines a plurality of longitudinally extending slots  516   k  configured to engage a corresponding plurality of longitudinally extending splines defined on an outer surface of the over-stroke sleeve  610 . A distal most portion  516 L of the channel  516  is configured to slidably receive a portion of the outer shaft  422  of the endoscopic assembly  400  therethrough. 
     The cartridge cylinder  520  includes an elongate body  520   a  defining a proximal end wall  520   b  and a distal end wall  520   c  ( FIG. 46 ). The proximal end wall  520   b  is configured to engage the drive plunger  120  of the handle assembly  100 , such that distal advancement of the drive plunger  120  causes a corresponding distal advancement of the cartridge cylinder  520  within the proximal portion  516   a  of the channel  516 . The elongate body  520   a  defines a radially extending flange  522  adjacent to the distal end wall  520   c  and defines a proximally facing surface  522   a . As illustrated in  FIG. 46 , the proximally facing surface  522   a  is configured to abut the distal facing surface  516   c  of the medial portion  516   b  when the cartridge cylinder  520  is in an initial, proximal position and inhibit further proximal translation thereof. The distal end wall  520   c  of the cartridge cylinder  520  defines a longitudinally extending boss  524  that extends in a distal direction therefrom. The longitudinally extending boss  524  defines a channel  526  through a distal end portion thereof configured to slidably receive a linkage  530 . A distal end portion of the longitudinally extending boss  524  defines a lateral bore  524   a  extending normal to the channel  526 . Lateral bore  524   a  is configured to receive a proximal linkage pin  532  to rotatably secure the linkage  530  thereto, such that distal advancement of the cartridge cylinder  520  effectuates a corresponding distal advancement of the linkage  530 . 
     The linkage  530  ( FIG. 44 ) defines a generally rectangular profile extending between proximal and distal end portions  530   a  and  530   b , respectively, although it is contemplated that the linkage may define other suitable profiles such as elliptical, etc. The linkage  530  defines proximal and distal apertures  530   c  and  530   d  therethrough at corresponding proximal and distal end portions  530   a ,  530   b  thereof. The proximal aperture  530   c  is configured to receive the proximal linkage pin  532  therein to rotatably secure the linkage  530  to the cartridge cylinder  520  (e.g., the proximal linkage pin  532  is received within the proximal aperture  530   c  of the linkage  530  and the lateral bore  524   a  of the cartridge cylinder  520 ). The distal aperture  530   d  is configured to receive a distal linkage pin  534  that is configured to couple the spindle  540  to the linkage  530 . 
     With reference to  FIG. 47 , the spindle  540  defines a generally cylindrical profile extending between proximal and distal end portions  540   a  and  540   b , respectively, although it is contemplated that the spindle  540  may define other suitable profiles, such as elliptical, rectangular, square, etc. An outer surface  540   c  of the spindle  540  defines a pair of opposed flats  542  thereon, and defines a slot  544  therethrough at the proximal end portion  540   a  of the spindle  540 . The slot  544  extends through a proximal end surface  540   d  defined on the proximal end portion  540   a  such that the linkage  530  may be slidably received therein. The outer surface  540   c  of the spindle  540  defines a transverse hole  546  therethrough that is oriented normal to the slot  544  such that when the linkage  530  is received within the slot  544 , the transverse hole  546  and the distal aperture  530   d  of the linkage  530  are coaxially aligned. The distal linkage pin  534  is configured to be received within the transverse hole  546  to rotatably secure the linkage  530  to the spindle  540  such that distal advancement of the linkage  530  causes a corresponding distal advancement of the spindle  540  and proximal retraction of the linkage  530  causes a corresponding proximal retraction of the spindle  540 . The pair of opposed flats  542  define a channel  548  through a medial portion thereof that is configured to slidably receive an over-stroke pin  630  ( FIG. 44 ) of the over-stroke mechanism  600  therein. Although generally illustrated as being disposed at a medial portion of the spindle  540 , it is contemplated that the channel  548  may be disposed at any location along the length of the spindle  540 . The outer surface  540   c  of the spindle defines a transverse slot  540   e  therethrough configured to selectively receive a portion of the lockout spring  592  therein. The transverse slot  540   e  is oriented normal to the channel  548  and is longitudinally disposed such that the transverse slot  540   e  extends entirely therethrough. As can be appreciated, the transverse slot  540   e  may be a single slot or may include a pair of opposed slots that do not extend within the channel  548 . The transverse slot  540   e  is disposed at a location configured to permit the lockout spring  592  ( FIG. 44 ) to be received therein once the final surgical clip of the plurality of surgical clips has been formed, as will be described in further detail hereinbelow. 
     Turning now to  FIGS. 48 and 49 , the hub assembly  510  of the endoscopic assembly  500  includes a display gear  550  rotatably and slidably disposed within the chamber  516   g  of the channel  516 . The display gear  550  defines a generally cylindrical profile extending between proximal and distal end surfaces  550   a  and  550   b , respectively. The proximal and distal end surfaces  550   a  and  550   b  of the display gear  550  define an aperture  552  therethrough that is configured to slidably receive the spindle  540  therein. The proximal end surface  550   a  of the display gear  550  defines an annular relief  554  thereon and terminating at a proximal facing surface  554   a . The proximal facing surface  554   a  of the display gear  550  defines a plurality of teeth  556  thereon. The plurality of teeth  556  is arranged in a circumferential direction about the proximal facing surface  554   a . The plurality of teeth  556  defines a first plurality of teeth  556   a  having a first thickness and a second plurality of teeth  556   b  having a second thickness. In this manner, the second plurality of teeth  556   b  extends radially inward a greater amount than the first plurality of teeth  556   a . In embodiments, the first plurality of teeth  556   a  includes twelve teeth, although it is contemplated that any suitable number of teeth may be utilized depending upon the needs of the procedure being performed. Although generally illustrated as including a pair of teeth defined on the proximal facing surface  554   a  at diametrically opposed locations, it is contemplated that the second plurality of teeth  556   b  may include any suitable number of teeth and each tooth may be disposed at any suitable location relative to one another. In operation, the first plurality of teeth  556   a  is configured to selectively engage the lower portion  518   b  of the pair of opposed bosses  518  of the inner surface  514  of the outer housing  512  and the second plurality of teeth  556   b  is configured to selectively engage the pair of opposed teeth  568   b  of the transmission gear  560 . 
     The proximal facing surface  554   a  of the annular relief  554  defines an annular slot  554   b  ( FIG. 48 a   ) extending towards the distal end surface  550   b . The annular slot  554   b  of the annular relief  554  is configured to selectively receive a portion of the transmission gear  560 , as will be described in further detail hereinbelow. A proximal portion of an interior surface  552   a  of the aperture  552  defines an annular groove  552   b  ( FIG. 48 a   ) therein configured to receive and retain the lockout spring  592  therein. The distal end surface  550   b  of the display gear  550  defines a counterbore  552   c  therein that is defined concentric with the aperture  552  and terminates at a distal facing surface  552   d . The counterbore  552   c  is configured to abut a display gear biasing element  580 . In embodiments, the distal end surface  550   b  of the display gear  550  may define a planar configuration configured to abut the display gear biasing element  580 . 
     An outer surface  550   c  of the display gear  550  defines a plurality of sections having a contrasting color  558 . The contrasting color  558  may be any suitable color capable of indicating to the clinician that the number of surgical clips remaining in the clip cartridge assembly (not shown) is below a certain threshold and that the last remaining surgical clip within the clip cartridge assembly has been formed. In this manner, as the display gear  550  is rotated, the amount of the contrasting color  558  that is visible through the plurality of windows  516   h  of the outer housing  512  increases until the entirety of each window of the plurality of windows  516   h  displays the contrasting color  558  to indicate that there are no surgical clips remaining in the clip cartridge assembly. 
     With reference to  FIGS. 50 and 51 , the hub assembly  510  of the endoscopic assembly  500  includes a transmission gear  560  rotatably and slidably disposed within the chamber  516   g  of the channel  516 . The transmission gear  560  defines a generally cylindrical profile extending between proximal and distal end surfaces  560   a  and  560   b , respectively. The proximal and distal end surfaces  560   a ,  560   b  define a throughbore  562  therethrough that is configured to slidably receive the spindle  540  therein. The proximal end surface  560   a  defines a counterbore  564  therethrough terminating at a medial portion of the transmission gear  560 , although it is contemplated that the counterbore  564  may terminate at any suitable depth. The proximal end surface  560   a  defines a plurality of teeth  566  thereon configured to selectively engage a portion of teeth defined on the driver gear  570  and a portion of the upper portion  518   a  of the pair of opposed bosses  518  of the inner surface of the outer housing  512 , as will be described in further detail hereinbelow. Each tooth of the plurality of teeth  566  defines a generally horizontal portion  566   a  and a generally beveled portion  566   b  such that as the generally beveled portion  566   b  of the transmission gear  560  engages the first bevel  518   c  of the upper portion  518   a  of the pair of opposed bosses  518 , the transmission gear  560  is caused to rotate. 
     The distal end surface  560   b  defines an annular relief  568  terminating at a distal facing surface  568   a . Although generally illustrated as terminating at a medial portion of the transmission gear  560 , it is contemplated that the annular relief  568  may terminate at any suitable portion of the transmission gear  560 . The annular relief  568  defines an outer surface  568   a  including a pair of opposed teeth  568   b  disposed thereon. Each tooth of the pair of opposed teeth  568   b  defines a beveled surface  568   c  configured to abut a corresponding tooth of the second plurality of teeth  556   b  of the display gear  550 . The annular relief  568  of the transmission gear  560  is configured to be received within a portion of the annular relief  554  of the display gear  550  to provide additional support and help maintain concentricity between the transmission gear  560  and the display gear  550 . 
     With reference to  FIGS. 51 and 52 , the hub assembly  510  of the endoscopic assembly  500  includes a driver gear  570  slidably disposed within the chamber  516   g  of the channel  516 . The driver gear  570  defines an elongate body extending between proximal and distal end portions  572   a  and  572   b , respectively. The elongate body of the driver gear  570  defines a generally square profile when viewed in a proximal to distal orientation and is configured to be slidably received within the annular flange  516   d  of the channel  516  such that the driver gear  570  is inhibited from rotating with respect to the annular flange  516   d . The distal end portion  572   b  defines a radially extending flange  574  having a generally cylindrical profile. A distal face  574   a  of the radially extending flange  574  defines a plurality of teeth  576  extending distally therefrom. Although generally illustrated as having four teeth, it is contemplated that the plurality of teeth  576  may include any suitable number of teeth, such as two, three, five, six, etc. Each tooth of the plurality of teeth  576  defines a generally horizontal upper surface  576   a  and a generally beveled surface  576   b  disposed opposite thereto. As can be appreciated, the orientation of the horizontal upper surface  576   a  and the beveled surface  576   b  of the plurality of teeth  576  are opposite (e.g., mirrored) to that of the beveled portion  566   b  and the horizontal portion  566   a  of the plurality of teeth  566  of the transmission gear  560 . As will be described in further detail hereinbelow, the pair of opposed bosses  518  of the inner surface  514  of the outer housing  512 , the first and second plurality of teeth  556   a ,  556   b  of the display gear  550 , the plurality of teeth  566  and the pair of opposed teeth  568   b  of the transmission gear  560 , and the plurality of teeth  576  of the driver gear  570  cooperate to rotate the display gear  550  each time a surgical clip is formed. 
     An outer surface  570   a  of the driver gear  570  defines a longitudinal slot  570   b  therein configured to slidably receive the distal linkage pin  534  therein. As can be appreciated, engagement of the distal linkage pin  534  within the longitudinal slot  570   b  maintains the orientation of the spindle  540  relative to the driver gear  570  during longitudinal movement of the spindle  540 . Additionally, during proximal retraction of the spindle  540 , the distal linkage pin  534  abuts a proximal portion of the longitudinal slot  570   b  to urge the driver gear  570  in a proximal direction. The proximal end portion  572   a  and the distal face  574   a  of the radially extending flange  574  define a throughbore  578  therethrough that is configured to slidably receive the spindle  540  therethrough. 
     With reference to  FIGS. 43 and 44 , a display gear biasing element  580  is interposed between the distal end wall  516   m  of the channel  516  and the distal end surface  550   b  of the display gear  550 . The display gear biasing element  580  biases the display gear  560  in a proximal direction such that the first plurality of teeth  556  of the display gear  550  engage the second bevel  518   d  of the lower portion  518   b  of the pair of opposed bosses  518  ( FIG. 45 ). Although generally illustrated as being a coil spring, it is contemplated that the display gear biasing element  580  may be any suitable biasing element such as a compression spring, an extension spring, a leaf spring, a Bellville washer or plurality of Bellville washers, an elastomer spring, a gas spring, etc. 
     A return biasing element  590  is disposed within the medial portion  516   b  of the channel  516  and is interposed between the distal end wall  520   c  of the cartridge cylinder  520  and the annular flange  516   d  of the channel  516 . Although generally illustrated as being a coil spring, it is contemplated that the return biasing element  590  may be any suitable biasing element capable of biasing the cartridge cylinder  520  in a proximal direction, such as a compression spring, and extension spring, a leaf spring, a Bellville washer or plurality of Bellville washers, an elastomer spring, a gas spring, etc. 
     With reference to  FIGS. 53A and 53B , the lockout spring  592  defines a generally lemniscate configuration, although other suitable configurations are also contemplated. The radially inward extending portions of the lockout spring  592  terminate at an interior portion thereof, such that each side of the lockout spring  592  remains in a spaced apart configuration forming a gap  592   a  therebetween configured to slidably receive the spindle  540  therein. A medial portion of the lockout spring  592  defines a pair of opposed tabs  592   a  defining a generally planar configuration, although other suitable configurations are also contemplated. The lemniscate profile of the lockout spring  592  biases the pair of opposed tabs  592  toward one another, thereby reducing the gap  592   b  formed therebetween. An upper and lower portion of the lockout spring  592  is configured to be received within the annular groove  552   b  of the display gear  550  such that the lockout spring  592  is retained therein and inhibited from rotating relative to the display gear  550 . 
     In operation, the spindle  540  is disposed within the gap  592   b  defined between the pair of opposed tabs  592  and is permitted to reciprocate therein during the formation of each surgical clip. Once a final surgical clip has been formed, the spindle  540  is permitted to advance in a distal direction until the pair of opposed tabs  592   a  of the lockout spring  592  align with the transverse slot  540   e  of the spindle. The bias of the lockout spring  592  urges the pair of opposed tabs  592   a  in a medial direction such that each tab of the pair of opposed tabs  592  is received within the transverse slot  540   e  to inhibit further translation of the spindle  640  in a distal or proximal direction. 
     With reference to  FIGS. 43 and 54-62 , in operation and in an initial state, the return biasing element  590  biases the cartridge cylinder  520  in a proximal direction to an initial, retracted position. In this initial position, the distal linkage pin  534  abuts a proximal portion of the longitudinal slot  570   b  of the driver gear  570  and causes the driver gear to be placed in an initial, proximal position. Additionally, the display gear biasing element  580  biases the display gear  550  in an initial, proximal position such that the first plurality of teeth  556   a  of the display gear  550  engage the lower portion  518   b  of the pair of opposed bosses  518  of the inner surface  514  of the outer housing  512 . 
     As the clinician actuates the trigger  104  of the handle assembly  100 , the drive plunger  120  is driven in a distal direction and abuts the proximal end wall  520   b  of the cartridge cylinder  520 . Continued actuation of the trigger  104  causes the drive plunger  120 , and thereby the cartridge cylinder  520 , to further advance in a distal direction and compress the return biasing element  590 . Distal advancement of the cartridge cylinder  520  causes a corresponding distal advancement of the linkage  530  and spindle  540 . During initial advancement of the spindle  540 , the distal linkage pin  534  translates within the longitudinal slot  570   b  of the driver gear  570  to allow distal advancement of the spindle  540  without causing a corresponding distal advancement of the driver gear  570 . As the trigger  104  is further actuated, the distal linkage pin  534  abuts a distal portion of the longitudinal slot  570   b  and causes the driver gear  570  to also advance in a distal direction. Continued actuation of the trigger  104  causes further distal advancement of the spindle  540  and a corresponding distal advancement of the driver gear  570  until the driver gear  570  engages the transmission gear  560 . During engagement of the driver gear  570  with the transmission gear  560 , the generally beveled portions  566   b  of the plurality of teeth  566  of the transmission gear  560  abut the generally beveled surfaces  576   b  of the plurality of teeth  576  of the driver gear  570  thereby causing the transmission gear to rotate 1/24 th  of a rotation (e.g., 15 degrees). Although generally illustrated as rotating in a counterclockwise direction, it is contemplated that the transmission gear may also be caused to rotate in a clockwise direction. 
     Additional actuation of the trigger  104  causes further distal translation of the transmission gear  560  and engagement of the transmission gear  560  with the display gear  550 . Due to the configuration of the first and second plurality of teeth  556   a ,  556   b  of the display gear  550 , the display gear  550  is caused to rotate only every 6 actuations of the trigger  104 . As such, the display gear  550  and the transmission gear  560  are oriented such that the first and second plurality of teeth  556   a ,  556   b  of the display gear are misaligned with the pair of opposed teeth  568   b  of the transmission gear, thereby resulting in no rotation of the display gear  550 , and a second scenario wherein the display gear  550  and the transmission gear  560  are oriented such that the first and second plurality of teeth  556   a ,  556   b  of the display gear are aligned with the pair of opposed teeth  568   b  of the transmission gear such that the display gear  550  is caused to rotate. 
     More specifically, in the first scenario, the pair of opposed teeth  568   b  of the transmission gear  560  are misaligned with the second plurality of teeth  556   b  of the display gear  550 . In this instance, the pair of opposed teeth  568   b  of the transmission gear  560  abut the proximal facing surface  554   a  of the display gear and drive the display gear  550  in a distal direction and compressing the display gear biasing element  580 . At this point, the spindle  540  continues to be urged in a distal direction and form a surgical clip that is loaded between the pair of jaws  450  of the endoscopic assembly  400 . 
     Once the surgical clip has been formed and the clinician releases the trigger  104  of the handle housing  100 , the return biasing element  590  biases the cartridge cylinder  520  in a proximal direction, thereby urging the linkage  530  and spindle  540  in a proximal direction. The display gear biasing element  580  biases the display gear  550  in a proximal direction and causes the transmission gear  560  and driver gear  570  to also translate in a proximal direction. The display gear biasing element  580  continues to urge the display gear  550  in a proximal direction causing the proximal facing surface  554   a  of the display gear  550  to abut the lower portion  518   b  of the pair of opposed bosses  518  of the inner surface  514  of the outer housing  512 . In this instance, because the display gear  550  has not rotated relative to the lower portion  518   b  of the pair of opposed bosses  518 , the first plurality of teeth  556   a  engage the lower portion  517   b  of the pair of opposed bosses  518  at a similar location from where they were initially, resulting in no rotation of the display gear  550 . 
     As the transmission gear  580  disengages from the display gear  550  and the transmission gear  560  is further urged in a proximal direction, the generally beveled portions  566   b  of the plurality of teeth  566  of the transmission gear  560  abut the first bevel  518   c  of the upper portion  518   a  of the pair of opposed bosses  518  and cause the transmission gear  560  to rotate a further 1/24 th  of a rotation (e.g., 15 degrees), resulting in a total rotation of 1/12 th  of a rotation (e.g., 30 degrees). As can be appreciated, the amount of rotation of the transmission gear  560  is correlated to the number of surgical clips to be fired, and therefore, the amount of rotation during each firing of a surgical clip may vary accordingly. 
     In the second scenario, the pair of opposed teeth  568   b  of the transmission gear  560  are aligned with the second plurality of teeth  556   b  of the display gear  550 . In this instance, the beveled surface  568   c  of each tooth of the pair of opposed teeth  568   b  abuts a respective tooth of the second plurality of teeth  556   b  to cause the display gear  550  to rotate. Although generally shown as rotating in a clockwise direction, it is contemplated that the display gear  550  may also rotate in a counterclockwise direction. Continued actuation of the trigger  104  further urges the transmission gear  560  in a distal direction, causing the display gear  550  to rotate 1/24 th  of a rotation (e.g., 15 degrees) and urge the display gear  550  in a distal direction and compressing the display gear biasing element  580 . At this point, the spindle  540  continues to be urged in a distal direction to form a surgical clip that is loaded between the pair of jaws  450  of the endoscopic assembly  400 . 
     Once the surgical clip has been formed and the clinician releases the trigger  104  of the handle housing  100 , the return biasing element  590  biases the cartridge cylinder  520  in a proximal direction, thereby urging the linkage  530 , and the spindle  540 , in a proximal direction. The display gear biasing element  580  biases the display gear  550  in a proximal direction and causes the transmission gear  560  and the driver gear  570  to also translate in a proximal direction. The display gear biasing element  580  continues to urge the display gear  550  in a proximal direction causing the first plurality of teeth  556   a  of the display gear  550  to abut the beveled surface  518   d  of the lower portion  518   b  of the pair of opposed bosses  518 , which causes the display gear  550  to rotate a further 1/24 th  of a rotation (e.g., 15 degrees), resulting in a total rotation of 1/12 th  of a rotation (e.g., 30 degrees). As can be appreciated, the amount of rotation of the display gear  550  is correlated to the number of surgical clips to be fired, and therefore, the amount of rotation per engagement with the lower portion  518  of the pair of opposed bosses  518  may vary accordingly. As described hereinabove, the display gear  550  is configured to rotate twice for a given stack of surgical clips (e.g., once every 6 clips). Thus, after the initial 1/12 th  of a rotation (e.g., 30 degrees), a portion of the contrasting color  558  of the display gear  550  is visible through the plurality of windows  516   h  of the outer housing  512  ( FIG. 61A ). After the second 1/12 th  of a rotation (e.g., 30 degrees) of the display gear  550 , the entirety of the each window of the plurality of windows  516   h  is filled by the contrasting color  558  of the display gear  550  to indicate that all of the surgical clip with the clip cartridge assembly have been formed ( FIG. 61B ). 
     After the second 1/12 th  of a rotation of the display gear  550 , the pair of opposed tabs  592   a  of the lockout spring  592  align with the transverse slot  540   e  of the spindle  540 , permitting the pair of opposed tabs  592   a  to be received within the transverse slot  540   e  ( FIG. 52 ). Once received within the transverse slot  540   e , the pair of opposed tabs  592   a  inhibit proximal and distal translation of the spindle  540  (e.g., locking the spindle  540  in place) such that if the clinician actuates the trigger  104  of the handle assembly  100  again, the clinician is unable to actuate the trigger  104  and close the pair of jaws  450  of the endoscopic assembly  400  to prevent injury to the patient and medical personnel and prevent damage to the surgical clip applier  10 ′. 
     With reference to  FIGS. 43, 44, and 62 , it is contemplated that the endoscopic assembly  400  may include an over-stroke mechanism  600  disposed within the counterbore  516   j  of the channel  516  of the outer housing  512 . The over-stroke mechanism  600  includes an over-stroke sleeve  610 , an over-stroke biasing element  620 , and an over-stroke pin  630 . The over-stroke sleeve  610  defines a generally cylindrical configuration extending between proximal and distal end surfaces  610   a  and  610   b , respectively. The proximal and distal end surfaces  610   a ,  610   b  define an aperture  612  therethrough configured to slidably receive the outer shaft  422  of the endoscopic assembly  400  therein. The proximal end surface  610   a  defines a counterbore  614  ( FIG. 64B ) therethrough terminating at a proximal facing surface  614   a  ( FIG. 64B ). The counterbore  614  is configured to receive the over-stroke biasing element  620  therein. Although generally illustrated as being a coil spring, it is contemplated that the over-stroke biasing element  620  may be any suitable biasing element such as a Bellville washer, a plurality of Bellville washers, an elastomeric spring, a gas spring, a leaf spring, etc. 
     An outer surface  610   c  of the over-stroke sleeve  610  defines a longitudinal slot  616  therethrough adjacent the proximal end surface  610   a . Longitudinal slot  616  is configured to slidably receive the over-stroke pin  630  therein and act as a travel limiter for the spindle  540 . As illustrated in  FIG. 64B , the over-stroke biasing element  620  is interposed between the proximal facing surface  614   a  of the over-stroke sleeve  610  and the over-stroke pin  630 . The outer surface  610   c  of the over-stroke sleeve  610  defines a generally crenellated profile having a plurality of longitudinally extending splines  618  configured to engage the plurality of longitudinally extending slots  516   k  of the counterbore  516   j  of the channel  516 , such that the over-stroke sleeve  610  is inhibited from rotating relative to the outer housing  512 . 
     For a detailed description of exemplary over-stroke mechanisms for use with endoscopic surgical clip appliers such as those described herein, reference can be made to U.S. Provisional Patent Application Ser. No. 62/527,222 to Baril, filed Jun. 30, 2017 and titled “ENDOSCOPIC REPOSABLE SURGICAL CLIP APPLIER,” the entire content of which is incorporated by reference herein. 
     With reference to  FIGS. 64A-64E , the operation of the over-stroke mechanism  600  will be described where the spindle  540  has translated in a distal direction further than is normal during the forming a surgical clip. In the initial, unactuated position, the over-stroke pin  630  is disposed within an aperture defined within a proximal portion of the outer shaft  422 , within the channel  548  of the spindle  540 , and within the longitudinal slot  616  of the over-stroke sleeve  610 . During actuation of the trigger  104  of the handle assembly  100 , the spindle  540  is urged in a distal direction such that the over-stroke pin  630  transitions from a distal position within the channel  548  of the spindle  540  to a proximal position within the channel  548 . If the trigger  104  is further actuated, the spindle  540  is further urged in a distal direction which can cause damage to the pair of jaws  450  of the endoscopic assembly  400 . To prevent damage to the pair of jaws  450 , as the spindle  540  translates further in a distal direction, the over-stroke pin  630 , and therefore the outer shaft  422 , is urged in a distal direction along with the spindle  540 , thereby causing the over-stroke biasing element  620  to compress. The compression of the over-stroke biasing element  620 , and resulting distal translation of the outer shaft  422 , eliminates further clamping of the pair of jaws  450  and prevents any damage to the pair of jaws  450 . Upon release of the trigger  104  of the handle assembly  100 , the over-stroke biasing element  620  urges the over-stroke pin  630  in a proximal direction and returns the outer shaft  422  to its initial, proximal position. The longitudinal slot  616  of the over-stroke sleeve  610  inhibits the over-stroke pin  620  from translating in a proximal direction past the initial, proximal position of the outer shaft  422 . 
     It is further contemplated that the over-stroke mechanism  600  may prevent damage to the pair of jaws  450  if the pair of jaws  450  become jammed or an object otherwise becomes lodged between the pair of jaws  450 . In this manner, as the spindle  540  is coupled to the outer shaft  422 , distal translation of the spindle  540  causes the outer shaft  422  to concurrently translate in a distal direction if the pair of jaws  450  are unable to close. For a detailed description of the operation of the over-stroke mechanism  600 , reference can be made to U.S. Provisional Patent Application Ser. No. 62/527,222 to Baril, previously incorporated by reference herein. 
     In accordance with the present disclosure, the trigger stroke length for trigger  104  of handle assembly  100  is constant or fixed, while the closure stroke length of the pair of jaws  450  of endoscopic assembly  400  connected to handle assembly  100  is different than, for example, the closure stroke of the pair of jaws  250  of endoscopic assembly  200 . For example, endoscopic assembly  400  may require the pair of jaws  450  thereof to travel a relatively greater or smaller distance as compared to the pair of jaws  250  of endoscopic assembly  200  in order to complete a full opening and closing thereof. As such, universal handle assembly  100  may be loaded with, and is capable of firing, either endoscopic assembly  200  or endoscopic assembly  400 . 
     In accordance with the present disclosure, while the trigger stroke length of trigger  104  of handle assembly  100  is constant, the closure stroke length for the pair of jaws  250 ,  450  of each endoscopic assembly  200 ,  400  is unique for each respective endoscopic assembly  200 ,  400 . Accordingly, each drive assembly  230 ,  430  of respective endoscopic assemblies  200 ,  400  functions to accommodate for the variations in the closure stroke lengths for the pair of jaws  250 ,  450  of respective endoscopic assemblies  200 ,  400 . 
     To the extent consistent, handle assembly  100  and/or endoscopic assemblies  200 ,  400  may include any or all of the features of the handle assembly and/or endoscopic assemblies disclosed and described in International Patent Application No. PCT/CN2015/080845, filed Jun. 5, 2015, entitled “Endoscopic Reposable Surgical Clip Applier,” International Patent Application No. PCT/CN2015/091603, filed on Oct. 10, 2015, entitled “Endoscopic Surgical Clip Applier,” and/or International Patent Application No. PCT/CN2015/093626, filed on Nov. 3, 2015, entitled “Endoscopic Surgical Clip Applier,” the entire content of each of which being incorporated herein by reference. 
     Surgical instruments such as the clip appliers described herein may also be configured to work with robotic surgical systems and what is commonly referred to as “Telesurgery.” Such systems employ various robotic elements to assist the surgeon and allow remote operation (or partial remote operation) of surgical instrumentation. Various robotic arms, gears, cams, pulleys, electric and mechanical motors, etc. may be employed for this purpose and may be designed with a robotic surgical system to assist the surgeon during the course of an operation or treatment. Such robotic systems may include remotely steerable systems, automatically flexible surgical systems, remotely flexible surgical systems, remotely articulating surgical systems, wireless surgical systems, modular or selectively configurable remotely operated surgical systems, etc. 
     The robotic surgical systems may be employed with one or more consoles that are next to the operating theater or located in a remote location. In this instance, one team of surgeons or nurses may prep the patient for surgery and configure the robotic surgical system with one or more of the instruments disclosed herein while another surgeon (or group of surgeons) remotely control the instruments via the robotic surgical system. As can be appreciated, a highly skilled surgeon may perform multiple operations in multiple locations without leaving his/her remote console which can be both economically advantageous and a benefit to the patient or a series of patients. 
     The robotic arms of the surgical system are typically coupled to a pair of master handles by a controller. The handles can be moved by the surgeon to produce a corresponding movement of the working ends of any type of surgical instrument (e.g., end effectors, graspers, knifes, scissors, etc.) which may complement the use of one or more of the embodiments described herein. The movement of the master handles may be scaled so that the working ends have a corresponding movement that is different, smaller or larger, than the movement performed by the operating hands of the surgeon. The scale factor or gearing ratio may be adjustable so that the operator can control the resolution of the working ends of the surgical instrument(s). 
     The master handles may include various sensors to provide feedback to the surgeon relating to various tissue parameters or conditions, e.g., tissue resistance due to manipulation, cutting or otherwise treating, pressure by the instrument onto the tissue, tissue temperature, tissue impedance, etc. As can be appreciated, such sensors provide the surgeon with enhanced tactile feedback simulating actual operating conditions. The master handles may also include a variety of different actuators for delicate tissue manipulation or treatment further enhancing the surgeon&#39;s ability to mimic actual operating conditions. 
     Referring to  FIG. 65 , a medical work station is shown generally as work station  1000  and generally may include a plurality of robot arms  1002 ,  1003 ; a control device  1004 ; and an operating console  1005  coupled with control device  1004 . Operating console  1005  may include a display device  1006 , which may be set up in particular to display three-dimensional images; and manual input devices  1007 ,  1008 , by means of which a person (not shown), for example a surgeon, may be able to telemanipulate robot arms  1002 ,  1003  in a first operating mode. 
     Each of the robot arms  1002 ,  1003  may include a plurality of members, which are connected through joints, and an attaching device  1009 ,  1011 , to which may be attached, for example, a surgical tool “ST” supporting an end effector  1100 , in accordance with any one of several embodiments disclosed herein, as will be described in greater detail below. 
     Robot arms  1002 ,  1003  may be driven by electric drives (not shown) that are connected to control device  1004 . Control device  1004  (e.g., a computer) may be set up to activate the drives, in particular by means of a computer program, in such a way that robot arms  1002 ,  1003 , their attaching devices  1009 ,  1011  and thus the surgical tool (including end effector  1100 ) execute a desired movement according to a movement defined by means of manual input devices  1007 ,  1008 . Control device  1004  may also be set up in such a way that it regulates the movement of robot arms  1002 ,  1003  and/or of the drives. 
     Medical work station  1000  may be configured for use on a patient  1013  lying on a patient table  1012  to be treated in a minimally invasive manner by means of end effector  1100 . Medical work station  1000  may also include more than two robot arms  1002 ,  1003 , the additional robot arms likewise being connected to control device  1004  and being telemanipulatable by means of operating console  1005 . A medical instrument or surgical tool (including an end effector  1100 ) may also be attached to the additional robot arm. Medical work station  1000  may include a database  1014 , in particular coupled to with control device  1004 , in which are stored, for example, pre-operative data from patient/living being  1013  and/or anatomical atlases. 
     Reference is made herein to U.S. Pat. No. 8,828,023, the entire content of which is incorporated herein by reference, for a more detailed discussion of the construction and operation of an exemplary robotic surgical system. 
     It is contemplated, and within the scope of the present disclosure, that other endoscopic assemblies, including a pair of jaws having a unique and diverse closure stroke length thereof, may be provided with a drive assembly, similar to any of the drive assemblies described herein, for accommodating and adapting the closure stroke length for the pair of jaws thereof to the constant trigger stroke length. 
     Accordingly, various endoscopic assemblies, constructed in accordance with the principles of the present disclosure, may be provided which are also capable of firing or forming or closing surgical clips of various sizes, materials, and configurations, across multiple platforms for multiple different manufactures. 
     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.