Abstract:
A clip detent spring forming part of a mechanism for inserting clips into the jaws of a clip applying instrument performs the tasks of engaging and separating a first in line clip from a line of clips carried by the mechanism, and the task of positioning the clip for insertion into the instrument jaws.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to surgical clip appliers embodied as an instrument having a supply of clips for rapidly deploying several clips in closing severed blood vessels and other small fluid carrying ducts in surgical procedures. There are many different designs for surgical clip applicators for a variety of surgical procedures including both open surgery and laparoscopy in which a clipping appliance fits through a trocar tube into a body cavity where the clips are applied. 
   A surgical clip applicator comprises an operating handle and clip applying mechanism having an operating cycle in which operating levers are squeezed together and released. In this operating cycle, a clip is applied in surgery and the clip applicator jaws are reloaded with a lead or first in line clip from a clip supply channel for clip application in the next applicator mechanism cycle. The applicator provides a moveable clip supply channel containing a line of clips that are released seriatim. 
   This invention provides a new and useful clip detent spring for separating the lead clip in the clip supply channel, and for moving the lead clip into a set position from which the lead clip is pushed into clip applying jaws. 
   SUMMARY OF THE INVENTION 
   A repeating multi-clip applier embodying the clip detent spring according to the present invention comprises an instrument having an operating handle housing and a removable, fully rotatable and disposable clip applying cartridge. A full squeeze and release of operating handles applies a clip to a surgical site and reloads another clip into clip applying jaws of the instrument. 
   The clip actuating mechanism includes a combined actuating rod and in-line clip supply channel together with clip indexing mechanisms arranged so that with a squeeze of the operating levers, the actuating rod moves rearward in the appliance to apply a clip in surgery, capture the next in-line clip, index a line of clips rearward away from the clip jaws; and that with release of the operating levers, the jaws open, the next in-line clip is loaded into the jaws, the second next in-line clip is separated from the line, and the clip indexing movement is reset for the next cycle. The clip applicator includes a novel detent spring for separating the first in line clip, and for moving the clip into position from which the clip is pushed into the operating jaws. 
   Specific examples are included in the following description for purposes of clarity, but various details can be changed within the scope of the present invention. 
   OBJECTS OF THE INVENTION 
   An object of the invention is to provide a clip applicator having an a clip applying cartridge with a clip detent spring. 
   Another object of the invention is to provide a clip applicator having an clip detent spring for separating a first in line clip and for moving the separated clip into a set position from which the clip is pushed into clip applying jaws. 
   Other and further objects of the invention will become apparent with an understanding of the following detailed description of the invention or upon employment of the invention in practice. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     A preferred embodiment of the invention has been chosen for detailed description to enable those having ordinary skill in the art to which the invention appertains to readily understand how to construct and use the invention and is shown in the accompanying drawing in which: 
       FIG. 1  is a perspective view of a clip detent spring according to the invention. 
       FIG. 2  is an enlarged side elevation of clip detent spring according to the invention. 
       FIGS. 3   a, b, c, d  and  e  are fragmentary section views of the sequence of (a) a clip loaded in the jaws ready to fire and clip fired, (b) next-in-line clip being detained, (c) line of clips in cartridge being indexed rearward, (d) next-in -line clip moved downward into loading position, and (e) next-in line-clip loaded into the jaws ready for firing. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to the drawing, the clip applying mechanism shown in  FIGS. 3   a-e  includes a stationary housing upper shell  34  and a stationary clip plate  41 . The upper housing shell supports the clip detent spring  44  and has a guide ramp surface  34   a  for positioning clips for movement into clip applying jaws (not shown). 
   A movable clip supply magazine  42  is positioned between shell  34  and clip plate  41 . The movable clip supply magazine receives a line of clips C urged forward within the magazine by a clip follower  42   b  and coil spring  42   g . The magazine has an integral base plate  42   b  with integral clip stop spring  42   k  and a forward pusher plate  42   i.    
   An operating handle (not shown) provides linear reciprocating motion to the clip supply mechanism such that the clip supply magazine slides back and forth (see arrows in  FIGS. 3   a-e ) with respect to the stationary housing and clip plate. 
   A preferred embodiment of the clip detent spring comprises a leaf spring tang  44   a  with spaced depending panels  44   b-c  of identical edge contour including inclined rear edges  44   d  terminating in forwardly directed notches  44   e  for engaging the shoulders of a lead clip to separate the lead clip from the line as the line of clips and the clip magazine are pulled rearward by clip stop spring  42   k  with a pull of the operating handle. On release of the handle and consequent forward movement of the clip magazine ( FIGS. 3   d-e ), the cartridge pusher plate  42   i  engages the rear surface of the detained lead clip and pushes it into the crimping jaws. 
   The action of clip moving components is shown in  FIGS. 3   a-e  starting with  FIG. 3   a  which shows components in forward position and a clip C J  in the instrument jaws. 
   Referring to  FIG. 3   a , a first in line of clips C F  is at rest under the detent spring notches  44   e  for the purpose of separating clip C F . The detent spring  44  is stationary in that it is affixed to the under side of the housing cover  34  in position to capture and hold the lead clip C F  at the end of the forward excursion of the clip supply magazine. The detent spring takes and separates the lead clip C F  from the clip line in preparation for movement of the lead clip into the applicator jaws on a subsequent applicator cycle. The detent spring separates clip C F  by reaction as the inclined rear edges  44   d  ride up ( FIG. 3   e ) on forwardly moving clip C F  and snap down ( FIG. 3   a ) as the clip passes the shoulders. Such clip capture occurs as the clip magazine reciprocates during operation of the applicator. 
   From the position of  FIG. 3   a , a rearward pull of the operating handle begins immediate rearward sliding movement of clip supply magazine  42  with respect to stationary upper shell  34  and stationary clip plate  41 . The clip detent spring  44  holds and separates clip C F  from the line of clips. The line of clips moves rearward with the clip cartridge as clip stop spring  42   k  is cammed upward ( FIG. 3   b ) by cam slot  41   b  in clip plate  41 . As movement continues ( FIG. 3   c ), the cartridge pusher plate  42   i  also moves rearward sliding underneath clip C F  and coming to rest behind the clip ( FIG. 3   d ) at the end of the rearward stroke of the operating handles. As pusher plate  42   i  slides behind clip C F , the clip detent spring  44  (having a normal downward spring force) pushes clip C F  downward into contact with clip ramp  41   c . When the operating handles are released, beginning from the position of  FIG. 3   d  and continuing to  FIG. 3   e , the clip cartridge pusher plate  42   i  engages clip C F , pushes it forward between upper shell ramp surface  34   a  and clip plate ramp  41   c  and on into the instrument jaws. As this forward motion occurs, the clip detent spring  44  rides up on clip C L  with notches  44   d  coming to rest behind the clip shoulder as illustrated in  FIG. 3   a.    
   Various changes may be made to the structure embodying the principles of the invention. The foregoing embodiments are set forth in an illustrative and not in a limiting sense. The scope of the invention is defined by the claims appended hereto.