Abstract:
The invention relates to surgical gripping forceps with two gripping jaws movable relative to a main body, with each gripping jaw having a stationary pivot axis relative to the main body, and a lever arm, and with the lever arms being articulated via at least one push element. Each gripping jaw has its own pivot axis. The distance between the individual pivot axis and the midline of the main body is at least greater than 38% of the maximum width of the main body or the maximum diameter of the main body. The present invention also provides microsurgical gripping forceps that a substantial clamping force between the gripping jaws with customary force for actuating the forceps.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from Ser. No. PCT/EP2007/005245 filed Jun. 14, 2007, the entire contents of which are herein incorporated by reference. This application in turn claims priority from DE App. Ser. No. 10 2006 028 001.6 filed on Jun. 14, 2006. 
     FIGURE SELECTED FOR PUBLICATION 
     
       FIG. 2 
     
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to surgical gripping forceps with two gripping jaws movable relative to a main body. More specifically, the present invention relates to surgical gripping forceps with movable gripping jaws, with each gripping jaw having a stationary pivot axis relative to the main body, and a lever arm, and with the lever arms being articulated via at least one push element. 
     2. Description of the Related Art 
     The related art involves gripping forceps known from, for example, U.S. Pat. No. 5,342,390. As noted in &#39;390, the gripping jaws of these forceps are disposed on a jointly used pivot pin. The pivot pin intersects the midline of the main body of the forceps. In this way, the lever arms molded at the gripping jaws, through which gripping jaws are moved, can inevitably be developed relatively short. Also, a separate push element acts on each lever arm of the gripping jaws. 
     What is not appreciated by the prior art is the need for substantial claming force in a small size while allowing for customary or minimized actuating force. 
     ASPECTS AND SUMMARY OF THE INVENTION 
     The present invention is based on the now-recognized problem of developing surgical gripping forceps that allow a substantial clamping force with a customary force for actuating the forceps. Now appreciated by the inventors, the goal is to realize a small number of components with a small structural size of the forceps. 
     An object of the present invention is to provide surgical gripping forceps wherein each gripping jaw has its own pivot axis. The distance between the individual pivot axis and the midline of the main body is greater than about 38% of the maximum width of the main body or the maximum diameter of the main body. 
     Laparoscopic surgery requires special instruments. What all instruments have in common is the miniaturization, which is why laparoscopic surgery is also called endoscopic microsurgery. The instruments are inserted into the abdomen through long sleeves that generally have a diameter of between four to 12 millimeters, usually via Torkar sleeves, and they are operated manually outside of the abdominal cavity. 
     Microsurgery requires micro gripping instruments for the preparation as well as macro instruments for the extraction of resected organs. Various gripping instruments with a diameter of three, five or ten millimeters are available. There are atraumatic forceps as well as toothed forceps. They have gripping jaws that are pointed or wide, micro or macro. Some of the gripping instruments also have locking mechanisms. 
     The gripping jaws must be designed to be operated simply and safely. This includes a large manual force multiplication by the gripping forceps mechanism. It is also especially advantageous if the gripping forceps, i.e. the part that protrudes in the abdomen from the front of the Torkar sleeve, has as few parts as possible. Fewer parts always also means fewer joints for movement. This reduces the risk of injury and facilitates the disinfection of the gripping forceps. Logically, the latter applies only if the appropriate forceps are not a disposable device. 
     The present invention relates to a surgical gripping forceps with two gripping jaws movable relative to a main body, with each gripping jaw having a stationary pivot axis relative to the main body, and a lever arm, and with the lever arms being articulated via at least one push element. Each gripping jaw has its own pivot axis. The distance between the individual pivot axis and the midline of the main body is at least greater than 38% of the maximum width of the main body or the maximum diameter of the main body. The present invention also provides microsurgical gripping forceps that a substantial clamping force between the gripping jaws with customary force for actuating the forceps. 
     The above, and other aspects, features and advantages of the present invention will become apparent from the following description read in conduction with the accompanying drawings, in which like reference numerals designate the same elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of the present invention for gripping forceps shown in a closed view. 
         FIG. 2  is an opposite side perspective view of  FIG. 1  with the forceps open. 
         FIG. 3  is a rear perspective view of the embodiment in  FIG. 2 . 
         FIG. 4  is a top plan view of the embodiment in  FIG. 1  in a closed position. 
         FIG. 5  is a side graphical view of half of a gripping forceps according to the present invention in a closed position noting motion lines. 
         FIG. 6  is a side graphical view of the embodiment in  FIG. 5  but in an open position noting motion lines. 
         FIG. 7  is a side elevational view of the complete gripping forceps shown in a closed position. 
         FIG. 8  is the side elevational view in  FIG. 7  in an open position. 
         FIG. 9  is a partial cutaway view of a gripping forceps with only one gripping jaw shown in a closed position. 
         FIG. 10  is a partial cutaway view of a gripping forceps as in  FIG. 9  but with the jaw in a half open position. 
         FIG. 11  is a partial cutaway view of a gripping forceps as in  FIG. 9  but with the jaw in a completely open position. 
         FIG. 12  is a perspective view of a main body element of the present invention. 
         FIG. 13  is a perspective view of a push element of the present invention. 
         FIG. 14  is a perspective view of a gripping jaw element of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to several embodiments of the invention that are illustrated in the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms, such as top, bottom, up, down, over, above, and below may be used with respect to the drawings. These and similar directional terms should not be construed to limit the scope of the invention in any manner. The words “connect,” “couple,” and similar terms with their inflectional morphemes do not necessarily denote direct and immediate connections, but also include connections through mediate elements or devices. 
     Referring now to  FIGS. 1-3 , surgical gripping forceps  1  of the present invention are shown in closed and open representations. The gripping forceps comprise a main body  10 , a push element  40 , two gripping jaws  60 ,  70  and a guide pin  30 . 
     The main body  10  (further noted in  FIG. 12 ) includes a tube section  11  and a fork section  15 . The tube section  11  has a boring  12  in which the push element  40  is guided. Two opposing adapter elements  14  are molded at the back end of said push element. Via adapter elements  14 , the main body  10  is removably attached at a housing tube (not shown convenience), for example by means of a quarter-turn fastener mechanism. 
     Fork section  15  has two fork arms  16 ,  26  that are arranged at the tube section  11 , as shown. The outer walls of the fork arms  16 ,  26  are parts of a cylinder jacket, for example. The diameter of said cylinder is the main body diameter  22 . In the embodiment, it is 4.8 mm. The interior walls of the fork arms  16 ,  26  are planes that are located as parallel opposites. The distance of the planes, for example, corresponds to the interior diameter of the boring  12 . At their front ends, fork arms  16 ,  26  have a respective borings  28 ,  28 . The borings  28 ,  28 , which are in true alignment, have a designated midline  29  that perpendicularly intersects with the midline  13  of the main body  10 , as shown graphically. 
     Each front fork arm  16  (see  FIG. 12 ) has above the boring  28  a recess  17  that is U-shaped, as a groove, for example. The base of the recess partially has the surface area of a cylinder jacket. The center of the cylinder jacket is an upper pivot axis  61 . The rear fork arm  26  has a comparable recess  27 . The latter is orientated downward here and in part encloses a lower pivot axis  71 . The pivot axes  61 ,  71  and the midline  29  of the borings  28  are located on one plane. This plane is aligned normally relative to the midline  13  of the main body  10 . 
     Referring additionally now to  FIG. 13 , which depicts the push element  40 . Push element  40  includes a push pin section  41 , a guide section  42  and a bearing section  45 . The push pin section  41 , which accommodates the push element  40  in the main body  10 , has a cylindrical form. At its free end, the push pin section has a tapped hole, if applicable. In the latter, the actuating rod guided in the housing tube of the forceps is then removably fastened. The tapped hole, the housing tube and the actuating rod are not shown in the figures. 
     Push pin section  41  is followed by the guide section  42 , as shown (see also  FIG. 13 ). The latter has at least approximately the form of a cuboid with two planar, parallel facing side surface areas  43  (as shown). During use, with the assembled gripping forceps, these side surface areas  43  bear against the interior walls of the fork arms  16 ,  26  of the main body  10 , where they act as rotation prevention. The bent partial cylinder areas that border the side surface areas  43  at the top and bottom are part of a cylinder that has a diameter corresponding to the diameter of the main body. 
     Guide section  42  transitions into a bearing section  45 . The bearing section  45  corresponds to a thin-walled plate that has two link pins  48 ,  49  and a guide groove  51 . The link pins  48 ,  49  have opposite parallel midlines  58 ,  59 . Both midlines  58 ,  59  clamp a plane that is normally positioned relative to the midline  52  of the push element  40 . The upper link pin  48  according to (see  FIG. 13 ) is orientated forwardly, whereas the lower pivot pin  49  is aligned backwardly. Both link pins  48 ,  49  have the same distance relative to the midline  52 . The distance between the midlines  58 ,  59  is more than two-thirds of the main body diameter  22 . The link pins  48 ,  49  have a diameter of 1 mm, for example. 
     In the center between the link pins  48 ,  49  is a straight guide groove  51 , which is open toward the free end of the bearing section  45 . The closed end of the guide groove  51  has a part-cylindrical round corner. The midline of the round corner perpendicularly intersects the midline  52  of the structural component  40 . 
     Referring additionally now to  FIG. 14 , one of two gripping jaws  60  is detailed in perspective view. In the spatial relationship to the structural components  10  and  40  shown in  FIGS. 12 and 13 , this is the upper gripping jaw. Gripping jaw  60  is comprised of a jaw section  62  and a pivot area section  63 . Jaw section  62  has the form of half of a longitudinally divided cylinder. The diameter of said cylinder corresponds to the main body diameter  22 . The front free end of the jaw section  62  is rounded. The round corner radius corresponds to half of the main body diameter  22 . 
     The at least approximately circular disk-shaped pivot area section  63  runs in the front half of the gripping jaw  60 , i.e., the rear planar area of the pivot area section  63 —which contacts a bearing surface area  46  of the bearing section  45  of the push element  40 —is on a plane that is removed from the plane of the structural component center by half the width of the bearing section  45 . The structural component midline  68  runs in said center plane. Also on the structural component midline  68  is the atraumatic jaw gripping surface area  83 , which is planar here (see  FIG. 2 ). 
     In the upper area, the pivot area section  63  has a forward orientated pivot pin  65 . The pivot pin  65 , which has a midline  61 , has at least toward the bottom a cylindrical outer contour. There is a sickle shaped guide recess  67  below the pivot pin  65 . The bending radius of the guide recess  67  has a midpoint that is on the midline  61  of the pivot pin  65 . Consequently, the guide recess  67  has at least one edge  81  shaped like the arc of a circle, and the midpoint of said edge is also on the midline  61 . Below the guide recess  67 , a pivot link recess  66  is worked into the pivot area section  63  from the bottom. The pivot link recess  66  is a straight groove, for example, and the width of said groove is slightly greater than the diameter of the link pins  48 ,  49  of the push element  40 . Here too, parts of the base of the recess have the surface area of a cylinder jacket. 
     As noted in  FIG. 14 , a dashed auxiliary line  69  has been drawn on the visible planar surface area that bears against the interior wall of the appropriate fork arm  16 ,  26  of the main body  10  when the gripping forceps are assembled. Auxiliary line  69  is furthermore perpendicular on the plane of the jaw gripping surface area  83 . The front jacket line of the pivot pin  65  and the edge of the rear, planar wall of the pivot link recess  66  are on said auxiliary line  69 . 
     The fifth and last structural component of the gripping forceps is the cylindrical guide pin  30 , see for example  FIG. 2 . In the first embodiment, pin  30  has a diameter of approximately 1 mm, and its length is slightly less than the main body diameter  22 . Pin  30  sits in the borings  28  of the gripping arms  16 ,  26 , for example by means of a cross press fit. 
     Preferably, all five parts  10 ,  30 ,  40 ,  60 ,  70  of the gripping forceps are respectively made of a rust- and acid resistant steel, such as the chromium steel X20Cr13, for example. 
     Before explaining the cooperation of the forceps components, the operating principle is discussed briefly. Referring now to  FIGS. 5 and 6  which pictorially first show the operating principle for only one gripping jaw  60 . 
     As noted in  FIGS. 5-8 , gripping jaw  60  is a jaw section  62 ,  72  to which a lever arm  64 ,  74  with a recess  66 ,  76  and a pivot pin  65 ,  75  is fastened. The main body  10  is a boring  12  with a recess  17  arranged thereon. The push element  40  is disposed in the boring  12 . It engages with the pivot link recess  66 ,  76  via a link pin  48 . 
     During operation, to open the gripping jaw  60 , the push element  40  is moved toward the left (as shown) in the boring  12 . The link pin  48  urgingly acts on the pivot link recess  66  that, together with the lever arm  64  and the jaw section  62 , pivots upward in clockwise fashion. While doing so, the pivot pin  65  rotates in the recess  17  of the main body  10  (see for  FIG. 6 ). 
     Referring additionally now to  FIGS. 7 and 8  which depict the principle for the entire gripping forceps as noted herein. To that end, the outlines shown in  FIGS. 5 and 6  are first reflected downward. Then the original and the mirror image are slid into one another until the gripping jaws  60 ,  70  are located together, according to  FIG. 4 . To make do with a straight guide  40  here, both link pins  48 ,  49  are firmly arranged on a joint push element  40 . 
     During assembly, the individual parts  10 ,  30 ,  40 ,  60 ,  70  of the actual gripping forceps, (see  FIGS. 12 to 14 ), are assembled in that the push element  40 , with its guide section  42  first, is slid almost completely into the boring  12  of the main body  10 . The insertion depth is shown in.  FIG. 9 . Then the upper gripping jaw  60  is inserted from the top into the gap between the front fork arm  16  and the bearing surface area  46  of the push element  50 . In this way, the gripping jaw  60  is in extended position, i.e., its midline  68  runs parallel to the midline  13  of the main body  10  during  5  the insertion process. In the downward movement, the pivot pin  65  of the gripping jaw  60  comes to bear in the recess  17  of the main body  10 . Pivot axis  61  is spaced a distance  21  from the midline  29  of boring  28  and pivot axis  71  is spaced by the same distance  21  from the midline  29  of the boring  28 , thereby facilitating movement of the law section along directional arrows  2 . 2 . At the same time, the pivot link recess  66  of the gripping jaw  60  is slid over the link pin  49  of the push element  40 . The insertion of the gripping jaw  60  is completed as soon as the midline  68  of the gripping jaw  60  corresponds to the midline  13  of the twain body  10 . The lower gripping jaw  70  is inserted in the same manner from below. 
     With this arrangement of structural components, five recesses and/or borings are, at least partially, positioned on top of each other in the pivot area of the gripping forceps. Viewed from outward to inward, these are the two borings  28  of the fork arms  16 ,  26 , the two sickle shaped guide recesses  67 ,  77  of the gripping jaws  60 ,  70  and the guide groove  51  of the push element  40 . Finally, the guide pin  30  is then inserted through all recesses and affixed; see again  FIGS. 1 to 4 . 
     The function of the sickle shaped guide recess  67  of the gripping jaw  60 , which has not been described so far, is shown now in  FIG. 9 to 11 . As noted therein, the gripping forceps are shown in longitudinal section without the lower gripping jaw  70 . Also, a piece is broken out of the push element  40   
     The main body  10  accommodates the gripping jaw  60  in the recess  17  and on the guide pin  30 . The recess  17 , which is open on one side, accommodates the pivot pin  65 . To prevent an unintended upward travel of the pivot pin  65  and/or the gripping jaw  60 , the guide-pivot link recess  66  bears against the guide pin  30  at least via the edge  81 . Because the guide recess  67  bears against the guide pin  30 , it is possible to situate the pivot axis  61  of the gripping jaw  30  far away from the midline  13  within the main body  10 . This allows a large gripping forceps lever arm. 
     The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. In the claims, means- or step-plus-function clauses are intended to cover the structures described or suggested herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, for example, although a nail, a screw, and a bolt may not be structural equivalents in that a nail relies on friction between a wooden part and a cylindrical surface, a screw&#39;s helical surface positively engages the wooden part, and a bolt&#39;s head and nut compress opposite sides of a wooden part, in the environment of fastening wooden parts, a nail, a screw, and a bolt may be readily understood by those skilled in the art as equivalent structures. 
     Having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes, modifications, and adaptations may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.