Abstract:
Surgical gripping forceps are provided with one or two gripping jaws movable relative to a main body, wherein each moveable one of the gripping jaws has a pivot pin, fixed in position relative to the main body, and a lever arm. The lever arms are articulated via at least one push element. For this purpose each movable one of the gripping jaws has its own pivot pin. From the midline of the main body, the individual pivot pin has at least a distance greater than 38% of the maximum width of the main body or maximum diameter of the main body. The microsurgical gripping forceps operate with customary force for actuating the forceps, and permit a substantial applied clamping force.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from Ser. No. PCT/EP2007/007412 filed Aug. 23, 2007, the entire contents of which are herein incorporated by reference. This application in turn claims priority from DE App. Ser. No. 10 2006 040 5293 filed on Aug. 30, 2006. 
     
    
     FIG. SELECTED FOR PUBLICATION 
       [0002]    
       FIG. 2 
     
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    The invention relates to a surgical gripping forceps with two gripping jaws movable relative to a main body, wherein each gripping jaw has a pivot pin, fixed in position relative to the main body, and a lever arm, and wherein the lever arms are articulated via at least one push element. 
         [0005]    2. Description of the Related Art 
         [0006]    Laparoscopic surgery requires a special set of instruments. What all the instruments have in common is miniaturization, for which reason laparoscopic surgery is also known as endoscopic microsurgery. The instruments are introduced into the abdomen through long sleeves having a diameter generally between four and twelve millimeters, usually via Torkar sleeves, and they are operated with manual force outside the abdominal cavity. 
         [0007]    In microsurgery, one needs to have both fine gripping instruments for the preparation and also large ones for the extraction of resected organs. Various gripping instruments with a diameter of three, five or ten millimeters are available. On the one hand there are atraumatic forceps and on the other hand toothed forceps. They have gripping jaws that are pointed or broad, fine or large. Sometimes the gripping instruments also have locking mechanisms. 
         [0008]    The gripping forceps must be simple and safe to use. This includes a transmission of manual force by the gripping forceps mechanism. It is also advantageous for the gripping forceps, that is, the part which extends out from the Torkar sleeve in the abdomen, to have the fewest parts possible. Few parts always means few movable joints. This lowers the risk of injury and facilitates the disinfecting of the gripping forceps. The latter holds only when the particular forceps is not a disposable kind. 
         [0009]    A convention gripping forceps is known from U.S. Pat. No. 5,342,390, the entire contents of which are herein incorporated fully by reference. The gripping jaws of this forceps are mounted on a shared pivot pin. The pivot pin intersects the center line of the main body of the forceps. As a result, and as a detriment, the lever arms formed on the gripping jaws and moved via the gripping jaws are necessarily only relatively short in configuration. As an additional detriment, a separate push element acts on each lever arm of the gripping jaws. 
       ASPECTS AND SUMMARY OF THE INVENTION 
       [0010]    One aspect of the present invention proposes a solution that overcomes at least one of the detriments noted above. 
         [0011]    Another aspect of the present invention is to develop a surgical gripping forceps which, with a customary force for actuating the forceps, enables a substantial clamping force of the forceps between the gripping jaws while also minimizing the number of structural parts for a forceps of small size. 
         [0012]    In another aspect of the present invention, a solution is provided wherein at least one and preferably each gripping jaw has its own pivot pin. The individual pivot pin has at least a distance from the center line of the main body greater than 38% of the maximum width of the main body or maximum diameter of the main body. 
         [0013]    In one aspect of the present invention surgical gripping forceps are provided with one or two gripping jaws movable relative to a main body, wherein each moveable one of the gripping jaws has a pivot pin, fixed in position relative to the main body, and a lever arm. The lever arms are articulated via at least one push element. For this purpose each movable one of the gripping jaws has its own pivot pin. From the midline of the main body, the individual pivot pin has at least a distance greater than 38% of the maximum width of the main body or maximum diameter of the main body. The microsurgical gripping forceps operate with customary force for actuating the forceps, and permit a substantial applied clamping force. 
         [0014]    According to another alternative aspect of the present invention, there is provided a surgical gripping forceps apparatus, said apparatus comprising: (a) a main body; and (b) at least two gripping jaws extending outwardly from said main body, wherein at least one of said gripping jaws is movably arranged relative to said main body, and wherein said at least one movable gripping jaw further comprises: (i) a pivot pin, fixed in position relative to said main body, said pivot pin having at least a distance from a center line of said main body greater than thirty-eight percent (38%) of one of the maximum width of said main body and a maximum diameter of said main body; and (ii) a lever arm, wherein said lever arm is articulated via at least one push element. 
         [0015]    According to another alternative aspect of the present invention, there is provided a forceps apparatus, the apparatus comprising: a main body, the main body further comprising: (a) a tube segment, the tube segment comprising: (i) a central bore in which a push element is guided therethrough, (ii) a housing tube, and (iii) a plurality of adapter elements located at a rear end of the tube segment and further situated in a fixed relationship to each one of the plurality of adapter elements, and wherein the main body is detachably fastened to the housing tube, and (b) a fork segment, the fork segment having at least two fork arms, each of the fork arms are arranged on the tube segment and capable of gripping an object under direction of an apparatus user, and (c) wherein the main body is detachably fastened to the housing tube by means of a quarter-turn fastener. 
         [0016]    According to another aspect of the present invention, there is provided a surgical gripping forceps apparatus, the apparatus comprising: (a) a main body, and (b) at least two gripping jaws extending outwardly from the main body, wherein at least one of the gripping jaws is movably arranged relative to the main body, and wherein the at least one movable gripping jaw further comprises: (i) a pivot pin, fixed in position relative to the main body, the pivot pin having at least a distance from a center line of the main body greater than thirty-eight percent of the maximum width of the main body or a maximum diameter of the main body, and (ii) a lever arm, wherein the lever arm is articulated via at least one push element, and (c) a push element in the main body, the push element capable of articulating one or more of each of the movable gripping jaws. 
         [0017]    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  
         [0018]      FIG. 1  is a perspective left front view of a closed gripping forceps according to one aspect of the present invention. 
           [0019]      FIG. 2  is a perspective right front view of an open gripping forceps. 
           [0020]      FIG. 3  is a perspective rear view of  FIG. 3 . 
           [0021]      FIG. 4  is a top plan view of a gripping forceps. 
           [0022]      FIG. 5  is a schematic side view of half the gripping forceps in a closed position. 
           [0023]      FIG. 6  is a schematic side view of half the gripping forceps in an open position. 
           [0024]      FIG. 7  is a schematic side view of the whole closed gripping forceps. 
           [0025]      FIG. 8  is a schematic side view of the whole open gripping forceps. 
           [0026]      FIG. 9  is a partial sectional top view of a gripping forceps with only one gripping jaw in a closed position. 
           [0027]      FIG. 10  is a partial sectional top view of a gripping forceps as in  FIG. 9 , in a half-open position. 
           [0028]      FIG. 11  is a partial sectional top view of a gripping forceps as in  FIG. 10 , in a fully open position. 
           [0029]      FIG. 12  is a front perspective view of a main body member. 
           [0030]      FIG. 13  is a front perspective view of a push element. 
           [0031]      FIG. 14  is a front perspective view of a gripping jaw member. 
           [0032]      FIG. 15  is a perspective view of an alternative embodiment of a gripping forceps according to the present invention. 
           [0033]      FIG. 16  is a partial member of a gripping forceps embodiment as in  FIG. 16 . 
           [0034]      FIG. 17  is a perspective view of a pushing element according to  FIG. 15 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]    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 maybe 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. 
         [0036]    Referring now to  FIGS. 1-3  a surgical gripping forceps in closed and opened views are presented. The gripping forceps comprises a main body  10 , a push element  40 , two gripping jaws  60 ,  70 , and a guide bolt  30 . 
         [0037]    The main body  10 , also see  FIG. 12 , consists of a tube segment  11  and a fork segment  15 . The tube segment  11  has a central bore  12 , in which the push element  40  is guided. At its rear end, two adapter elements  14  situated opposite each other are formed. By these adapter elements  14 , the main body  10  is fastened to a housing tube (not shown) in detachable manner, e.g., by means of a quarter-turn fastener. 
         [0038]    The fork segment  15  has two fork arms  16 ,  26 , which are arranged on the tube segment  11 . The outer walls of the fork arms  16 ,  26  are, for example, parts of a cylindrical shell. The diameter of this cylinder is the diameter  22  of the main body. In the sample embodiment, it amounts to 4.8 mm. The inner walls of the fork arms  16 ,  26  are planes lying parallel to each other. The spacing between the planes corresponds, e.g., to the inner diameter of the central bore  12 . At their front ends, the fork arms  16 ,  26  each have a bore  28 . The bores  28 , aligned with each other, have a center line  29  that intersects perpendicularly the center line  13  of the main body  10 . 
         [0039]    The front fork arm  16  per  FIG. 12  has a groovelike recess  17 , of U shape for example, above the bore  28 . The bottom of the recess has partially the surface of a cylindrical shell. The center of the cylindrical shell is an upper pivot axis  61 . The rear fork arm  26  has a comparable recess  27 . The latter is oriented downward here and partially encloses a lower pivot axis  71 . The pivot axes  61 ,  71  and the center line  29  of the bores  28  lie in the same plane. This plane is oriented normal to the center line  13  of the main body  10 . 
         [0040]      FIG. 13  shows the push element  40 . It consists of a push pin segment  41 , a guide segment  42  and a bearing segment  45 . The push pin segment  41 , by which the push element  40  is mounted in the main body  10 , has a cylindrical shape. At its free end it can have a threaded bore. Then, in the latter, the actuating rod led through the housing tube of the forceps is detachably secured. The threaded bore, the housing tube, and the actuating rod are not shown in the figures. 
         [0041]    After the push pin segment  41  comes the guide segment  42 . The latter has at least approximately the shape of a cuboid, similar to that shown, with two plane side surfaces  43  parallel to each other. In the assembled gripping forceps, these side surfaces  43  lie against the inner walls of the fork arms  16 ,  26  of the main body  10 . Here, they have the function of twist prevention, among other things. The curved partially cylindrical surfaces which adjoin the side surfaces  43  at top and bottom belong to a cylinder whose diameter corresponds to the diameter of the main body. 
         [0042]    The guide segment  42  passes into a bearing segment  45 . The bearing segment  45  corresponds to a thin-wall plate, which has two link pins  48 ,  49  and a guide groove  51 . The link pins  48 ,  49  have center lines  58 ,  59  parallel to each other. The two center lines  58 ,  59  subtend a plane that lies normal to the center line  52  of the push element  40 . The upper link pin  48  per  FIG. 13  is oriented in front, while the lower one  49  is facing the rear. The two link pins  48 , 49  have the same distance from the center line  52 . The distance between the center lines  58 ,  59  is more than ⅔ of the diameter  22  of the main body. The link pins  48 ,  49  have a diameter, e.g., of 1 mm (millimeter). 
         [0043]    In the middle between the link pins  48 ,  49  is a straight guide groove  51 , which is open at the free end of the bearing segment  45 . The closed end of the guide groove  51  has a partially cylindrical rounding. The center line of the rounding intersects the center line  52  of part  40  perpendicularly. 
         [0044]      FIG. 14  shows one of two gripping jaws  60 . It is the upper gripping jaw in spatial relation to the parts  10  and  40  shown in  FIGS. 12 and 13 . The gripping jaw  60  consists of a jaw segment  62  and a pivot region segment  63 . The jaw segment  62  has the shape of half of a longitudinally divided cylinder. The diameter of this cylinder coincides with the diameter  22  of the main body. The front free end of the jaw segment  62  is rounded. The radius of the rounding corresponds to half the diameter  22  of the main body. 
         [0045]    The pivot region segment  63 , at least approximately in the shape of a circular disk, extends in the front half of the gripping jaw  60 . That is, the rear plane surface of the pivot region segment  63 —contacted by a bearing surface  46  of the bearing segment  45  of the push element  40 —lies in a plane which is half the width of the bearing segment  45  away from the central plane of the structural parts. The center line  68  of the structural part runs in this plane of centers. Also on this line lies the atraumatic jaw gripping surface  83 , which is flat here, see  FIG. 2 . 
         [0046]    In the upper region, the pivot region segment  63  has a forward extending pivot pin  65 . The pivot pin  65 , which has a center line  61 , has a cylindrical outer contour, at least at the bottom. Beneath the pivot pin  65  is a crescent-shaped guide cavity  67 . The radius of curvature of the guide cavity  67  has a center point which lies on the center line  61  of the pivot pin  65 . Consequently, the guide cavity  67  has at least one circular arc edge  81  whose center point likewise lies on the center line  61 . Beneath the guide cavity  67 , a link cavity  66  is produced in the pivot region segment  63  at the bottom. For example, the link cavity  66  is a straight groove, whose width is slightly larger than the diameter of the link pins  48 ,  49  of the push element  40 . The bottom of the cavity here as well as the surface of a cylindrical shell in part. 
         [0047]    In  FIG. 14 , an accessory dashed line  69  has been drawn on the visible plane surface which lies against the inner wall of the respective fork arm  16 ,  26  of the main body  10  when the gripping forceps is assembled. The accessory line  69 , furthermore, is perpendicular to the plane of the jaw gripping surface  83 . On this accessory line  69  lie the front contour line of the pivot pin  65  and the edge of the rear flat wall of the link cavity  66 . 
         [0048]    The fifth and last structural part of the gripping forceps is the cylindrical guide bolt  30 , see  FIG. 2 . Its diameter in the sample embodiment is 1 mm. Its length is slightly less than the main body diameter  22 . It sits in the bores  28  of the gripping arms  16 ,  26 , for example, by means of a transverse press fit. 
         [0049]    All five parts  10 ,  30 ,  40 ,  60 ,  70  of the gripping forceps are made from a stainless or acid resistant steel, for example, such as chromium steel X20Cr13. 
         [0050]    Before explaining the interaction of the parts of the forceps, the functional principle shall be briefly discussed. The functional principle is represented in  FIGS. 5 and 6 , at first for only one gripping jaw  60 . 
         [0051]    According to  FIG. 5 , the gripping jaw  60  is a jaw segment  62  on which a lever arm  64  is fastened by a link cavity  66  and a pivot pin  65 . The main body  10  is a straight guideway  12  with a pivot pin bearing  17  arranged thereon. The push element  40  is mounted in the straight guideway  12 . This engages with the link cavity  66  via a link pin  48 . 
         [0052]    To open the gripping jaw  60 , the push element  40  is pushed to the left into the straight guide  12 . The link pin  48  acts on the link guideway  66 . This along with the lever arm  64  and the jaw segment  62  swivels upward in the clockwise direction. At the same time, the pivot pin  65  rotates in the pivot pin bearing  17  of the main body  10 , see  FIG. 6 . 
         [0053]    The principle for the overall gripping forceps is shown in  FIGS. 7 and 8 . For this, the sketches presented in  FIGS. 5 and 6  are first shown mirrored at the bottom. Then original and mirror image are pushed together until the gripping jaws  60 ,  70  per  FIG. 4  lie against each other. Now, to make do with a single straight guideway  12 , both link pins  48 ,  49  are firmly arranged on a shared push element  40 . 
         [0054]    The individual parts  10 ,  30 ,  40 ,  60 ,  70  of the actual gripping forceps, see  FIG. 12 to 14 , are mounted by shoving the push element  40  with its guide segment  42  almost completely forward into the bore  12  of the main body  10 . The depth of insertion is shown in  FIG. 9 . Now, the upper gripping jaw  60  is inserted from the top into the gap between the front fork arm  16  and the bearing surface  46  of the push element  40 . The gripping jaw  60  is now in the extended position, i.e., its center line  68  runs parallel to the center line  13  of the main body  10  during the insertion process. During the downward movement, the pivot pin  65  of the gripping jaw  60  comes to rest in the cavity  17  of the main body  10 . At the same time, the link cavity  66  of the gripping jaw  60  is pushed via the link pin  59  of the push element  40 . The inserting of the gripping jaw  60  is finished once the center line  68  of the gripping jaw  60  coincides with the center line  13  of the main body  10 . The lower gripping jaw  70  is inserted from the bottom in comparable manner. 
         [0055]    In this arrangement of the structural parts, five cavities or bores lie at least partially superimposed in the link region of the gripping forceps. These are—looking in from the outside—the two bores  28  of the fork arms  16 ,  26 , the two crescent-shaped guide cavities  67 ,  77  of the gripping jaws  60 ,  70 , and the guide groove  51  of the push element  40 . Finally, the guide bolt  30  is inserted through all cavities and secured, see  FIG. 1 to 4 . 
         [0056]    The function of the crescent-shaped cavity  67  of the gripping jaw  60 , not yet described, shall be explained in  FIG. 9 to 11 . In these figures, the gripping forceps is shown in longitudinal section without the lower gripping jaw  70 . Furthermore, a piece has been broken off from the push element  40 . 
         [0057]    The main body  10  supports the gripping jaw  60  in the cavity  17  and on the guide bolt  30 . The pivot pin  65  lies in the cavity  17 , which is open to one side. The crescent-shaped guide cavity  67  encloses the guide bolt  30 . Now, to prevent an unintentional upward movement of the pivot pin  65  or gripping jaw  67 , the guide cavity  66  lies against the guide bolt  30  at least via the edge  81 . Thanks to the abutment of the guide cavity  67  against the guide bolt  30 , it is possible to situate the pivot axis  61  of the gripping jaw  60  far from the center line  13  inside the main body  10 . This enables a large lever arm for the gripping forceps. 
         [0058]      FIGS. 15 to 17  show a surgical gripping forceps in another modified configuration in opened representation. For this configuration, basically only the differing features will be described, making reference to  FIG. 1 to 14  and then description. The same reference numbers in the FIGS. designate the same or identically acting elements and the numbers with an “a” designate differing elements. 
         [0059]    The gripping forceps likewise comprises a main body  10 , a push element  40 , two gripping jaws  60   a,    70   a  and a guide bolt  30 . However, only one of the gripping jaws  60   a  is mounted movable in the main body  10  by means of a guide bolt  30 . The other of the gripping jaws  70   a,  on the other hand, is inserted stationary in the main body  10  or forms a single piece with the latter. 
         [0060]      FIG. 16  shows the nonmovable one of the gripping jaws  70   a.  The lower gripping jaw is in spatial relation to the structural parts  10  and  40  represented in  FIGS. 15 and 17 . The nonmovable gripping jaw  70   a  likewise consists of a jaw segment  72   a,  but instead of a pivot region segment it has a modified rear segment  73   a.  The jaw segment  62  in this configuration has the shape, for example, of an elongated ridge or a broadened blade. 
         [0061]    The rear segment  73  a extends in the front half of the gripping jaw  70   a,  as in the first embodiment. That is, the back plane surface of the rear segment  73   a  makes contact with a bearing surface of the bearing segment of the push element  40  and lies in a plane away from the plane of centers of the structural parts, especially by half the width of the bearing segment. The center line of the structural part lies in this plane of centers. The atraumatic jaw gripping surface  83   a,  which is likewise flat here, also lies on this line ( FIG. 15 ). 
         [0062]    In the upper region, the rear segment  73   a  has a forward extending pin  75   a  similar to the pivot pin of the first embodiment. The pin  75   a,  which has a center line  58 , has an outer cylindrical contour at least at the bottom. Beneath the pin  75   a  is a cylindrical cavity  77   a,  instead of a crescent-shaped guide cavity. The cylindrical cavity  77   a  sits on the guide bolt  30  ( FIG. 15 ). Due to this configuration, the lower gripping jaw  70   a  is inserted in the main body  10  so that it cannot move or pivot. 
         [0063]    Alternatively, one could also use a main body  10  forming a single piece with such a gripping jaw  70   a.    
         [0064]      FIG. 17  shows a modified push element  40 . Again, it consists of a push pin segment  41 , a guide segment  42  and a bearing segment. The push pin segment  41  adjoins the guide segment  42 . The latter, again, has the shape of a cuboid, for example, with two plane side surfaces  43  parallel to each other. The guide segment  42  passes into a front bearing segment  45 . 
         [0065]    The bearing segment  45  again corresponds to a thin-wall plate, for example, having in this configuration a guide groove  51  but only one such link pin  48 . In other words, there is no link pin  49   a  on the opposite side, which would have served to operate the stationary gripping jaw  70   a.  Accordingly, no link cavity  76   a  is required at the bottom in the gripping jaw  70   a,  contrary to the corresponding gripping jaw in the rear segment  73   a  beneath the cavity  77   a.