Abstract:
In order to be able to simplify the construction of a magazine for a surgical clip applicator comprising a receiving chamber for clips which are arranged one behind the other, are displaceable in the receiving chamber towards its open end and have two arms connected via a bridge and pivotable away from one another into an open position contrary to an elastic force and projections associated with these arms and projecting rearwards beyond the bridge, and comprising two opening tools which are located opposite one another, are movable towards one another like pincers and can be abutted on the projections of the respectively foremost clip, it is suggested that the opening tools be connected in a hinge-like manner to an advancing element displaceable in the magazine parallel to the direction of displacement of the clips and during its advancing movement in the direction towards the open end of the receiving chamber come to rest on a deflection surface of the magazine and thereby be pivoted inwards transversely to the direction of displacement towards the opening tool located respectively opposite.

Description:
This application is a continuation of international application number PCT/EP98/06775 filed Oct. 24, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to a magazine for a surgical clip applicator comprising a receiving chamber for clips which are arranged one behind the other and displaceable in the receiving chamber towards its open end, these clips having two arms which are connected via a bridge and pivotable away from one another into an open position contrary to an elastic force and projections which are associated with these arms and project rearwards beyond the bridge, and comprising two opening tools which are located opposite one another, are movable towards one another like pincers and can be abutted on the projections of the respectively foremost clip. 
     Magazines of this type are used to apply a larger number of clips from them, for example, for clamping the scalp during operations on the head. For this purpose, clip applicators with magazines are already known, in which the clips are stored one behind the other and from which the clips are moved forwards in steps. The respectively foremost clip is grasped by pincer-like opening tools which are movable on clip applicators of this type and mounted stationarily, and these pincer-like opening tools open the clip and apply it at the desired location (DE-PS 37 04 760). With devices of this type the opening tools are part of the devices, only the magazines with the clips accommodated therein can be exchanged. 
     The object of the invention is to design a generic magazine such that the construction of clip applicators of this type can, altogether, be simplified, in particular, due to the fact that the clip applicators do not require their own mechanism for opening and applying the clips. 
     BRIEF SUMMARY OF THE INVENTION 
     This object is accomplished in accordance with the invention, in a magazine of the type described at the outset, in that the opening tools are connected in a hinge-like manner to an advancing element displaceable in the magazine parallel to the direction of displacement of the clips and come to rest on a deflection surface of the magazine during the advancing movement of this advancing element in the direction towards the open end of the receiving chamber and are thereby pivoted inwards transversely to the direction of displacement towards the opening tool located respectively opposite. 
     With such a solution, the opening tools designed as hinge elements are thus part of the magazine and they are mounted in a simple manner in that they are connected in a hinge-like manner to an advancing element displaceable in longitudinal direction of the magazine. The advancing movement of the advancing elements is utilized to pivot these hinge elements inwards, and this advancing movement is generated by the abutment of the opening tools, which are connected in a hinge-like manner to the advancing elements, on a deflection surface of the magazine. This results in a particularly simple construction not only of the magazine but also of the entire clip applicator since it is sufficient to provide a mechanism on the clip applicator which moves the advancing elements back and forth in the magazine. Special opening tools on the clip applicator itself are no longer necessary. 
     As a result of this construction, very considerable opening forces can also be generated since the hinge element and the advancing element interact in the manner of a knee joint. The advancing movement is translated into a very slight angular pivoting, in particular, at the end of the advancing movement, and this very slight angular pivoting movement leads to a slight displacement of the opening tool on the clip to be opened, i.e. a reduction in the path of displacement occurs and thus an increase in the corresponding displacement force. The opening forces directed inwards are, for the rest, essentially taken over by the guide means for the advancing element, against which the advancing element abuts and on which the advancing element is thus supported. 
     It is particularly advantageous when the opening tools are pivotable outwards contrary to an elastic restoring force which is smaller than the force required to open the clips. As a result of this restoring force, the opening tools are pivoted inwards against the clips and abut with their free edges on the clips, in particular, on the projections of the respectively foremost clip but they do not yet open the clip since this elastic restoring force is smaller than the required opening force. This elastic abutment of the opening tools on the foremost clip results in the foremost clip being held between the opening tools until it is moved forwards into the application position. 
     A particularly advantageous development results when the opening tools are connected to the advancing elements in one piece via a weakened hinge area. 
     The opening tools and the advancing element can then consist, in particular, of a flexible plastic material so that a cheap construction of the magazine, which can, in this case, also be produced as a disposable part, results. 
     In accordance with a preferred embodiment it is provided for the deflection surface to be formed by the end wall of the magazine adjoining the open end of the receiving chamber on both sides. 
     A particularly advantageous construction results when the advancing element has entraining members which can be abutted on the clips for the step-wise advancement of the clips. 
     The advancing element thus undertakes an additional function, namely that of advancing all the clips which are stored in the magazine and which are moved forwards by the length of a clip with each advancing movement of the advancing element, wherein this advancing movement of the advancing elements also causes the closure of the opening tools at the same time. 
     In a preferred embodiment it is provided for the opening tools to abut on the projections of the foremost clip during the advancement of the advancing elements before the entraining members of the advancing element abut on following clips. As a result, the respectively foremost clip is moved further forwards than the remaining clips and thus is at a distance from the following clip which is sufficient for the insertion of the opening tools. 
     The entraining members are designed to be able to disengage from the receiving chamber so that the clips moved forward during the advancement of the advancing element are not drawn back again during the return movement of the advancing elements. The entraining members can thereby be disengaged from the receiving chamber in different ways; in a preferred embodiment it is provided for the entraining members to slide elastically along the clips when the advancing element is withdrawn, i.e., in this case, the clips themselves press the entraining members elastically outwards. 
     The entraining members can be designed, in particular, as spring tongues which protrude at an angle into the receiving chamber in the direction of advancement. Apart from the entraining function, the spring tongues also have the task with this construction of guiding the clips along their path of displacement and securing them against any tilting. 
     In a preferred embodiment it is provided for the advancing elements to be designed as half shells which together form the channel-like receiving chamber for the clips. 
     These half shells are fixed in position relative to one another in the direction of advancement, for example, by means of projections and undercuts interacting in a positive manner so that during the displacement of one advancing element in longitudinal direction the other advancing element is automatically taken along. 
     In this respect, it is advantageous when the half shells are mounted in an elongated housing of the magazine for displacement in its longitudinal direction. 
     In this respect, it may be provided for the half shells to be held in mutual abutment by the housing. As a result, a guidance of the half shells by the housing surrounding the half shells is, on the one hand, brought about; on the other hand, it is not necessary to permanently connect the two half shells securely to one another, the abutment by means of the surrounding housing is sufficient to fix the two half shells in position surrounding the clips. 
     The clips may be secured in position in the receiving chamber against any undesired rearward displacement in various ways, for example, by means of frictional engagement with the side walls. 
     In accordance with a particularly preferred embodiment, it is provided for retaining projections for the clips, which can be disengaged from the receiving chamber and are fixed in position in longitudinal direction of the magazine, to protrude into the receiving chamber. These are arranged such that the clips can be displaced forwards when the retaining projections are disengaged but are prevented from moving back when the retaining projections are engaged. 
     The retaining projections may, in particular, be movable flexibly out of the receiving chamber, i.e. the clips press the retaining projections flexibly out of the receiving chamber during advancement but abut on the retaining projections engaged in the receiving chamber during any rearward movement. 
     It is advantageous when the retaining projections are spring tongues which protrude at an angle into the receiving chamber in the direction of advancement. 
     In a preferred embodiment, the retaining projections are arranged on the side walls of the receiving chamber. An arrangement then results, with which the entraining members of the advancing elements are, for example, arranged on the upper side and the underside of the clips, the retaining projections, on the other hand, on the two side walls. 
     It is advantageous when the retaining projections are held on supports which are inserted laterally into the receiving chamber and fixed in position on the magazine so as to be axially non-displaceable. In this respect, these may, for example, be metal strips which have notches bent elastically inwards as retaining projections. 
     In accordance with a preferred embodiment it is provided for the advancing elements to have on their outer side recesses which adjoin one another in longitudinal direction and in which a transport entrainment means engages which can be displaced back and forth in the direction of displacement of the clips. This transport entrainment means displaces the advancing elements reciprocatingly back and forth in the magazine, wherein, on the one hand, the clips are moved forwards each time by one step while, on the other hand, the respectively foremost clip is opened for application and closed again. 
     It is favorable when the base of the recess is separated from the advancing element on three sides and forms the entraining member for the clips protruding into the receiving chamber. This results in a particularly simple, constructional design for the advancing elements. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The following description of preferred embodiments of the invention serves to explain the invention in greater detail in conjunction with the drawings. These show: 
     FIG.  1 : a longitudinal sectional view of a clip applicator with inserted magazine; 
     FIG.  2 : a sectional view along line  2 — 2  in FIG. 1; 
     FIG.  3 : a sectional view along line  3 — 3  in FIG. 2; 
     FIG.  4 : an enlarged partial longitudinal sectional view of the magazine with a clip advanced for application prior to opening; 
     FIG.  5 : a view similar to FIG. 4 with a clip advanced for application and opened and 
     FIG.  6 : a view similar to FIG. 4 with the clip applied and the advancing element withdrawn again. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The clip applicator illustrated in the drawings comprises a handpiece  1  with a stationary handle part  2  and an actuating handle  3  which is pivotally mounted thereon and is pivotable into a foremost position by means of a spiral spring  4  secured in position on the handle part  2 . 
     The handpiece  1  terminates towards the upper side with a flat contact surface  5 , on which an elongated housing  6  with a rectangular cross section is releasably held. This housing  6  is secured on the contact surface  5  by means of laterally projecting transverse pins  7 , which engage in a recess  8  of the handpiece  1  which is open towards the front, and by a locking member  9  which dips into a locking recess  10  of the handle part  2  and can be released by means of suitable actuating means which are not illustrated in the drawings. 
     The housing  6  is open at its rear end  11 ; at its front end  12  it is closed by an end wall  13  which has a central outlet opening  14  extending over the entire width of the housing. 
     Two advancing elements  15  designed as half shells and having the same construction are mounted in the interior of the housing  6  so as to be displaceable longitudinally. These advancing elements  15  abut on one another with their side edges  16  and here engage with projections  17  in recesses  18  of the respectively other advancing element  15  in a positive manner so that the two advancing elements  15  are thereby fixed in position relative to one another in longitudinal direction of the housing  6 . 
     The two advancing elements  15  facing one another with their open side fill the cross section of the housing  6  completely and enclose a receiving chamber  19  which extends over their length and serves to accommodate clips  20  which are U-shaped or C-shaped in cross section. 
     The two advancing elements  15  have on their upper side and underside, respectively, a number of recesses  21  which are of a parallelepiped design in the embodiment illustrated and are arranged along the center line of the advancing elements  15 . The base  22  of each recess  21  is of a relatively thin design and separated on three sides of the recess  21  so that the base  22  is connected to the advancing element  15  only at the rear transverse edge. In addition, the base  22  is deformed inwards so that these bases  22  form tongue-like entraining members  23  which project at an angle inwards and come to rest on the rear side of the clips  20  in a manner explained in more detail further on. The entraining members  23  can be pivoted elastically outwards so that they can be disengaged outwards from the receiving chamber  19  as a result. 
     An opening  24  is provided in the contact surface  5  of the handpiece  1  and a transport entrainment means  25  which engages in one of the recesses  21  of an advancing element  15  protrudes through this opening. During pivoting of the actuating handle  3 , this transport entrainment means  25  is moved forwards relative to the contact surface  5  and thereby takes along the two advancing elements  15 . It is thus possible to move the advancing elements forwards by pivoting the actuating handle  3  and move the advancing elements  15  back again by pivoting the actuating handle  3  back. The length of the path of displacement is thereby greater than the length of one clip  20 . 
     In the receiving chamber  19  formed by the two half-shell advancing elements  15 , strip-like or plate-like supports  26  are inserted along the side surfaces of the receiving chamber  19  and a row of spring tongues  27 , which are directed at an angle into the receiving chamber  19  towards the front end of the housing  6 , is separated out of these supports. The supports  26  are fixed in position on the housing  6  by suitable means, e.g., locking elements so as to be non-displaceable in longitudinal direction; the spring tongues  27  thus form retaining elements which protrude into the receiving chamber  19  and can be pivoted flexibly out of it. The distance between adjacent retaining elements is, like the distance between adjacent entraining members on the advancing elements  15 , determined by the length of the clips and is slightly greater than this. 
     At the front end, a wall section  28  is integrally formed on each of the two advancing elements  15  as an extension of the upper side and lower side, respectively, this wall section being connected to the rest of the advancing element in a hinge-like manner by a weakened area  29  such that the wall section  28  is pivotable inwards about a pivot axis extending transversely to the longitudinal direction of the receiving chamber  19 . This wall section  28  is pivoted inwards in its rest position and can be pivoted outwards contrary to an elastic restoring force. 
     The clips  20  filling the receiving chamber  19  one behind the other have two arms  31  which extend essentially parallel to one another and are connected to one another via a bridge  32 . They consist of an elastic material, for example, a sterilizable plastic and the two arms  31  are pressed towards one another with their free ends  33  due to the inherent elasticity of the material. These free ends  33  form clamping strips. 
     In extension of the two arms  31 , projections  34  project rearwards beyond the bridge  32  with outwardly directed recesses  35 ; these projections  34  serve to open the clips. When these projections  34  are brought closer to one another, the bridge  32  bent into the clip in the shape of an arc is deformed and the arms  31  open contrary to the elastic restoring force of the bridge  32 . 
     During use of the clip applicator described, a magazine accommodating the housing  6 , the advancing elements  15 , the supports  16  and a number of clips  20  inserted into the receiving chamber  19  one behind the other is placed on the contact surface  5  of the handpiece  1  in the manner described. The two advancing elements  15  are thereby located in a withdrawn position, the entraining members  23  designed as flexible locking tongues abut on the respective arms  31  of a clip  20  and thereby align the clip  20  relative to the receiving chamber (FIG.  1 ). 
     By actuating the actuating handle  3 , the advancing elements  15  are moved forwards, and the entraining members  23  thereby abut with their free edges on the rear sides of the clip  20  located in front of them; as a result, these clips  20  are moved forwards by a clip length together with the advancing element  15 . They thereby move the spring tongues  27  of the supports  26  elastically outwards and slide past them. 
     In their foremost position the clips  20  are advanced to such an extent that the spring tongues  27  can spring back into the receiving chamber again and are positioned with their free edges immediately behind the bridges  32  of the clips  20  moved past them. 
     When, following this advancing movement of the advancing elements  15 , the se are drawn back again, the clips  20  are prevented from moving backwards by the sprung-back spring tongues  27  and are held in their advanced position. During the return movement of the advancing elements  15 , the entraining members  23  designed as spring tongues slide along and past the clips  20  held in this manner until they come to rest laterally on the next following clip and position this in the manner described at the outset. All the clips  20  can therefore be displaced forwards by a clip length in the direction towards the outlet opening  14  of the receiving chamber  19  during each actuation of the actuating handle  3 . 
     The respectively foremost clip in the row of clips  20  arranged in the receiving chamber  19  is not moved forwards by an entraining member  23  of the advancing elements  15  but by the wall sections  28  arranged at the front end of the advancing elements  15 . 
     With the advancing elements  15  withdrawn, these wall sections engage with their free edges  36  in the recesses  35  of the projections  34  of the clip  20  and take this clip along during the advancement of the advancing element  15  to such an extent that the clip  20  projects out of the housing  6  with its arms  31  through the outlet opening  14  (FIG.  4 ). The holding force is thereby applied by means of the elasticity of the wall sections  28  directed inwards; this elastic force is sufficient to hold the clips  20  but not sufficient to open the clips  20 . 
     When the advancing elements  15  are advanced further, the wall sections  28  abut on the edges  37  of the end wall  13  of the housing  6  limiting the outlet opening  14  on both sides and are pivoted inwards even more during the further advancement of the advancing elements  15 , i.e. come closer to one another with their free edges  36 . The edges  37  of the end wall  13  thus form a deflection surface which pivots the wall sections  28  inwards on account of the advancing movement of the advancing elements  15 . 
     As a result of the movement of the free edges  36  of the wall sections  28 , which come closer to one another during this advancing movement of the advancing elements  15 , the projections  34  of the clips  20  are also brought closer to one another, and this leads in the manner described to an opening of the arms  31  contrary to the elastic closing force (FIG.  5 ). 
     As soon as the clip  20  engages around the desired point of application with the opened arms  31 , for example, the location of a cut in the scalp, the clip  20  can be closed again. For this purpose, it is sufficient to move the advancing elements  15  back again by means of the actuating handle  3 . The return movement of the advancing elements  15  occurs immediately the actuating handle  3  is pivoted forwards again; the return movement of the advancing element  15  is thereby aided by the spring force of the opened clip which is then closing. 
     Once the clip  20  has been closed and the advancing elements  15  withdrawn further, the wall sections  28  exit from the recesses  25  of the projections  34  again with their free edge  36  and release the clip  20  which is now in an application position (FIG.  6 ). During the further movement backwards of the advancing elements  15  the wall sections  28  slide along the following clip which is secured against any displacement backwards by the spring tongues  27  abutting on it. The free edges  36  of the wall sections  28  pass at the end of the return movement into the recesses  35  in the projections  34  of this clip  20  which can then be applied in the desired position during the next advancing cycle in the manner described. 
     The dimensions are selected such that the entraining members  23  maintain a distance to the clips  20  located in front of them when the advancing element  15  is completely withdrawn while the wall sections  28  already rest with the free edge  36  in the recess  35  of the foremost clip  20 . During the advancing movement of the advancing elements  15 , only the foremost clip is, first of all, pushed forwards and only then do the entraining members  23  abut on the remaining clips and push these forwards. As a result, the distance between the foremost clip and the following clip is increased so that sufficient space is created for the wall sections  28  which cause the clips to open to dip in. 
     As soon as the magazine has been emptied in the manner described, it may be removed from the handpiece  1  and replaced by a new, filled magazine. 
     It is favorable when the advancing elements  15  at least are manufactured in one piece from a flexible, sterilizable plastic material; the housing  6  may also consist of a sterilizable plastic material. The supports  26  with the spring tongues  27  are preferably designed as metal strips.