Electrosurgical bipolar forceps with a connecting rod

Abstract

The invention relates to electrosurgical bipolar forceps (10), comprising: a first limb (12) and a second limb (14), which are pivotally mounted on each other by means of a pivot joint (16); and a stabilizing device (44) for stabilizing the forceps (10) against transverse forces, the stabilizing device (44) having a connecting rod (46) mounted on the proximal side of the pivot joint (16), and the connecting rod (46) having a first bearing structure (48), which is mounted displaceably and rotatably on the first limb (12), and a second bearing structure (50), which is rotatably mounted on the second limb (14).

Description

[0001] Applicant:

[0002] Aesculap AG

[0003] At Aesculap Square

[0004] 78532 Tuttlingen

[0005] General Power of Attorney: 752190 . 9

[0006] 03920016WO 18.09.2025

[0007] BUR / KUN / MAY

[0008] Title: Electrosurgical bipolar forceps with a

[0009] connecting rod

[0010] Description

[0011] The disclosure relates to an electrosurgical bipolar forceps for preparing, in particular grasping, cutting and / or sealing, tissue, especially vessels, in surgical applications.

[0012] Such an electrosurgical bipolar forceps typically comprises a first arm and a second arm, which are pivotally mounted relative to each other. The forceps have a clamping arrangement on a distal side of the pivot joint, with a first clamping element forming a first electrode and a second clamping element forming a second electrode. Electrosurgical bipolar forceps are generally known as surgical sealing and / or cutting instruments. For sealing, tissue grasped or clamped between the clamping elements of the arrangement is subjected to high-frequency (HF) alternating current, which flows between the two electrodes and through the grasped tissue. This heats and seals the tissue. For cutting clamped and, in particular, sealed tissue, a movable cutting unit with a cutting edge may be provided.

[0013] US patent 10,111,699 B2 discloses electrosurgical forceps with a cutting unit to which a locking mechanism is associated. The locking mechanism comprises a push plate that is coupled to the cutting unit for movement. The locking mechanism also comprises a flat locking arm that is movably guided in an L-shaped guide slot of the push plate. When the forceps are opened / closed, the locking arm is displaced along the guide slot. If the locking arm is arranged in a section of the guide slot extending longitudinally along the forceps, the push plate and the cutting unit can be displaced. A stabilizing effect with respect to lateral forces in connection with the locking arm is not disclosed.

[0014] The present disclosure is based on the objective of providing an electrosurgical bipolar forceps with improved handling. In particular, the forceps are to be stabilized against the interlocking of the arms.

[0015] This problem is solved by an electrosurgical bipolar forceps having the features of claim 1.

[0016] The forceps according to the invention comprise a first leg and a second leg, the legs being pivotably mounted relative to each other by a pivot joint. On a distal side of the pivot joint, the forceps have a clamping arrangement. The distal side of the pivot joint is the side facing away from the user when the forceps are used as intended. The clamping arrangement comprises a first clamping element, which forms a first electrode of the forceps, and a second clamping element, which forms a second electrode of the forceps. Tissue can be clamped between the clamping elements of the clamping arrangement, in particular to seal the clamped tissue. Preferably, the first clamping element is part of a distal section of the first leg and the second clamping element is part of a distal section of the second leg. On a proximal side of the pivot joint, the forceps have a handle for handling the forceps.The proximal side of the swivel joint is the side facing the user when the pliers are used as intended. The handle assembly is formed by the proximal sections of the arms. Preferably, each arm has at least one finger opening to form the handle assembly. This allows for particularly safe handling of the pliers. However, the handle assembly can also be designed in another way that allows the user to handle the pliers.

[0017] The pliers according to the invention also comprise a stabilizing device for stabilizing the pliers against lateral forces. Within the scope of the disclosure, the term "lateral forces" refers to forces that act on the jaws parallel to the pivot axis of the swivel joint and radially offset from the pivot axis of the swivel joint. The stabilizing device comprises a connecting rod, preferably rigid, which is arranged on the proximal side of the swivel joint. The connecting rod comprises a first bearing structure, which is slidably and rotatably mounted on the first jaw, and a second bearing structure, which is rotatably mounted on the second jaw. During opening and closing operations of the pliers, the first bearing structure of the connecting rod is displaced along the first jaw. In addition, the first bearing structure is rotated relative to the first jaw, and the second bearing structure is rotated relative to the second jaw.Preferably, the first bearing structure is slidably mounted along a sliding axis that is aligned perpendicular to the pivot axis of the swivel joint. The inventors have recognized that the claimed stabilizing device with the connecting rod can improve the handling of the pliers. The connecting rod prevents the jaws from twisting due to transverse forces, particularly when closing the pliers. Consequently, the stabilizing device promotes the intended arrangement of the clamping elements relative to each other when clamping fabric. The claimed connecting rod has proven to be particularly effective because, when closing the pliers, the connecting rod lies flatter against the jaws, thereby further increasing the stabilizing effect of the connecting rod as the pliers are opened less fully.

[0018] Preferably, the ratio of the height of the connecting rod to its width in the cross-section of the connecting rod is at most 2:1, particularly preferably at most 1.5:1. The width of the connecting rod is its extent along an axis parallel to the pivot axis of the swivel joint. The height of the connecting rod is its extent along an axis perpendicular to both its longitudinal extent and the pivot axis of the swivel joint, i.e., to the width of the connecting rod. Such a width allows for a connecting rod with advantageous bending stiffness. Consequently, the connecting rod is particularly suitable for reliably absorbing transverse forces acting on the legs. Preferably, the connecting rod has a cross-section that is at least approximately square.

[0019] Preferably, the second bearing structure is fixedly mounted on the second leg and rotatably supported. Thus, only the first bearing structure is slidably mounted, namely on the first leg. This design of the stabilizing device is preferred because the movement of the connecting rod during opening and closing operations of the pliers is then clearly defined.

[0020] Preferably, the first leg has an elongated guide structure on which the first bearing structure is slidably and rotatably mounted. The elongated guide structure can be an elongated guide groove.

[0021] In some preferred embodiments, the guide structure has a proximal end, i.e., an end located closer to the user, and a distal end, i.e., an end further away from the user. The proximal and distal ends of the guide structure limit the movement of the first bearing structure along the guide structure in the proximal and distal directions, respectively. Preferably, the guide structure is linear. Consequently, the first bearing structure can be moved linearly along the guide structure. Preferably, the guide structure extends along the longitudinal axis of the first leg or parallel to the longitudinal axis of the first leg. When the pliers are closed, the connecting rod, or at least one main arm of the connecting rod, preferably extends along the longitudinal axis of the first leg or parallel to the longitudinal axis of the first leg.This design of the pliers allows for particularly effective stabilization through the connecting rod.

[0022] In some preferred embodiments, the guide structure is formed in an integral part of the first leg. The guide structure is therefore not located in a part movably attached to the first leg. In some embodiments, the guide structure is formed in a support structure of the first leg. The support structure can, for example, be formed by a sheet metal stack. In some other embodiments, the guide structure is formed in a handle part of the first leg made of plastic. The guide structure can also be formed jointly by the support structure and the handle part made of plastic.

[0023] In some preferred embodiments, the first bearing structure comprises at least one first bearing journal which is slidably and rotatably mounted on or in the elongated guide structure of the first leg. The first bearing structure may also have two first bearing journals which project laterally from the guide rod in opposite directions and are slidably and rotatably mounted in separate elongated guide structures of the first leg. Such a double-sided mounting on the first leg achieves particularly effective stabilization of the pliers. Preferably, the guide structure extends along the length of the first leg. The guide structure may be straight. Alternatively, the elongated guide structure may also have an angled profile. Preferably, the first bearing journal is cylindrical.

[0024] In some preferred embodiments, the guide structure is formed by an elongated hole formed in the first leg.

[0025] In some preferred embodiments, the second bearing structure has at least one second bearing journal, which is rotatably mounted on the second leg. The second bearing structure can also have two second bearing journals projecting in opposite directions from the guide rod and each rotatably mounted on the second leg. It is also possible for the second bearing structure to be slidably and rotatably mounted on or within an elongated guide structure of the second leg. Preferably, the second bearing journal is cylindrical. In some preferred embodiments, the at least one first bearing journal is monolithically formed with the connecting rod. This reduces the number of parts moving relative to each other, thereby achieving a particularly pronounced stabilizing effect.However, it is also possible that at least one of the first bearing pins is rotatably mounted on the connecting rod.

[0026] In some preferred embodiments, the at least one second bearing journal is monolithically formed with the connecting rod. This reduces the number of parts moving relative to each other, thereby achieving a particularly pronounced stabilizing effect. However, it is also possible for the at least one second bearing journal to be rotatably mounted on the connecting rod.

[0027] In some preferred embodiments, the connecting rod is an injection-molded part. Injection molding allows the connecting rod to be manufactured cost-effectively and precisely. Preferably, the connecting rod is made of plastic, particularly by injection molding.

[0028] In some preferred embodiments, the connecting rod is mounted on the first leg and the second leg in such a way that the first bearing structure of the connecting rod is pushed away from the pivot joint when the clamp is closed. This has the advantage of mechanically relieving the pivot joint, because when the clamp is closed, the point where lateral forces from the first leg are introduced into the connecting rod is pushed away from the pivot joint.

[0029] In some preferred embodiments, the pliers are provided with a maximum opening state, and the connecting rod prevents the pliers from opening beyond this maximum opening state. The connecting rod thus forms the opening limiter of the pliers. This makes it possible to design the area at the pivot joint as thin as possible, i.e., with less material and therefore less strength, without compromising the stability of the pliers.

[0030] In some preferred embodiments, the first leg, in particular the guide structure of the first leg, has a limit stop, and the first bearing structure, in particular the first bearing journal, rests against the limit stop in the maximum opening state. This prevents the limit stop from further displacement of the first bearing structure and consequently from opening the pliers beyond the maximum opening state.

[0031] In some preferred embodiments, the second leg has an elongated recess, and the connecting rod rests in this recess when the pliers are closed. Such a design of the stabilizing device has proven particularly effective, as the connecting rod gradually engages in the recess as the pliers close, thereby further enhancing the stabilizing effect of the connecting rod as the pliers open less. Preferably, the connecting rod rests in the recess without play when the pliers are closed. Preferably, the recess is shaped such that the connecting rod is positively guided into the recess when the pliers close.

[0032] The recess is bounded by two opposing side flanks. When the pliers are closed, the connecting rod is positioned between these side flanks. The connecting rod also has two side flanks, with each side flank of the connecting rod facing a different side flank of the recess when the pliers are closed. In some preferred embodiments, at least one of the side flanks of the connecting rod is convex. This means that the side flank of the connecting rod is curved towards the opposite side flank of the recess. This has the advantage that, when the pliers are closed, the connecting rod is guided into the recess by the convex shape of its side flank. Tilting of the connecting rod is reliably prevented. Preferably, the side flank of the connecting rod is convexly curved about an axis that runs along the longitudinal axis of the connecting rod.Preferably, both side flanks of the connecting rod are convex. If one or both side flanks of the connecting rod are convex, then the side flanks of the recess are preferably flat.

[0033] In some preferred embodiments, at least one of the side flanks of the recess is convex. The side flank of the recess is thus curved towards the connecting rod. This also has the advantage that, when the pliers are closed, the connecting rod is guided into the recess by the convex shape of the side flank. Preferably, the side flank is convexly curved about an axis that runs along the longitudinal axis of the recess. Preferably, both side flanks of the recess are convex. If one or both side flanks of the recess are convex, the side flanks of the connecting rod are preferably flat.

[0034] In some preferred embodiments, one of the legs, in particular the second leg, has an activation switch for activating the clamp, while the other leg, in particular the first leg, has an activation structure that can be pressed against the activation switch by closing the clamp. In these embodiments, the clamp is thus activated by closing the clamp. Activation of the clamp in this context means that the clamping elements of the clamp are subjected to high-frequency alternating current. The stabilizing device has proven particularly advantageous in this context, because it also ensures that the activation structure is pressed against the activation switch as intended when the clamp is closed.Preferably, a notch, in particular a V-shaped one, is formed on one side of the activation switch facing the activation structure. This reliably prevents the activation structure from slipping off the activation switch.

[0035] Preferably, the connecting rod is angled along its longitudinal extent.

[0036] In some preferred embodiments, the connecting rod has a longer main arm and a shorter secondary arm along its longitudinal extent, the latter being angled relative to the main arm. When the jaws are closed, the main arm rests against the second leg along its longitudinal extent. The secondary arm, on the other hand, bridges a gap between the elongated main arm and the first leg when the jaws are closed, particularly a gap between the elongated main arm and the guide structure of the first leg. Such a design of the connecting rod has proven particularly effective in stabilizing the jaws. The main arm resting against the second leg effectively prevents the legs from interlocking. Preferably, when the jaws are closed, the main arm rests in the aforementioned, particularly groove-like, recess of the second leg.

[0037] In some preferred embodiments, the pliers are provided with a cutting unit, in particular an elongated one, with a cutting edge for cutting tissue clamped by the clamping arrangement. The cutting unit is preferably slidably mounted on the first leg between a proximal and a distal position. Alternatively, the cutting unit can also be slidably mounted on the second leg between a proximal and a distal position. To perform a cutting operation, the cutting unit is slidable from the proximal to the distal position, at least when the pliers are closed. Preferably, the cutting edge of the cutting unit is arranged on a distal end face, i.e., an end face facing away from the user when the pliers are used as intended.

[0038] In some preferred embodiments, the cutting unit can be subjected to a restoring force by opening the pliers using the connecting rod, in particular by means of the first bearing structure of the connecting rod. This force displaces the cutting unit from the distal position towards the proximal position. The connecting rod thus has an additional technical function: it is part of a restoring mechanism that forcibly displaces the cutting unit from the distal position towards the proximal position when the pliers are opened.

[0039] In some preferred embodiments, the pliers are provided with a locking element that is pivotably mounted on the first leg between a locking position and a release position. In the locking position, the locking element prevents the cutting unit from moving from the proximal position towards the distal position. In the release position, the cutting unit is free to move from the proximal position towards the distal position. Preferably, the locking element can be subjected to a release force by closing the pliers using the connecting rod, in particular by means of the first bearing structure of the connecting rod, which pivots the locking element from the locking position to the release position. The connecting rod thus has an additional technical function.The connecting rod is part of a release mechanism by which the locking element is pivoted from the locked position to the release position when the pliers are closed.

[0040] Further advantages will become apparent from the description and the accompanying drawings. Exemplary embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. Here, identical reference numerals in different figures denote identical or at least functionally comparable elements. When describing individual figures, reference may also be made to elements from other figures. The following are shown schematically:

[0041] Figure 1 shows a side view of an electrosurgical bipolar forceps with a first arm and a second arm;

[0042] Figure 2 shows a side view of the open pliers with the handle removed;

[0043] Figure 3 shows a side view of the closed pliers with the handle removed;

[0044] Figure 4 shows a side view of the supporting structures of the legs;

[0045] Figure 5 shows an exploded view of the supporting structure of the first leg;

[0046] Figure 6 shows the supporting structure of the first leg with a slidably mounted blade;

[0047] Figure 7 shows a connecting rod of the pliers; and

[0048] Figures 8A-8G show detailed views of the forceps at different times during a cutting process. Figure 1 shows a side view of an electrosurgical bipolar forceps 10. The forceps 10 has a first arm 12 and a second arm 14. The arms 12 and 14 are pivotally mounted relative to each other about a pivot axis 18 by a pivot joint 16 (see Figures 2 to 4). By pivoting the arms 12 and 14, the forceps 10 can be opened and closed. Figure 2 shows the forceps 10 in their maximum opening position. Figure 3 shows the forceps 10 in the closed position.

[0049] The forceps 10 have a clamping arrangement 20 on a distal side of the pivot joint 16. The distal side of the pivot joint 16 is the side of the pivot joint 16 that faces away from the user when the forceps 10 are used as intended. The clamping arrangement 20 comprises a first clamping element 22 and a second clamping element 24. By closing the forceps 10, tissue can be clamped between the clamping elements 22 and 24. The first clamping element 22 is formed by a distal section of the first leg 12. The second clamping element 24 is formed by a distal section of the second leg 14.

[0050] The pliers 10 have a handle arrangement 26 on a proximal side of the swivel joint 16 for handling the pliers 10 by a user. The proximal side of the swivel joint 16 is the side of the swivel joint 16 that faces the user when the pliers 10 are used as intended. In this case, the handle arrangement 26 is formed by several handle parts 28 made of plastic. Finger openings 30 can be formed in the handle parts 28.

[0051] Figure 4 shows a side view of the pliers 10 without the handle parts 28. In the present embodiment, the first arm 12 has a sheet metal stack 32 as a supporting structure. Figure 5 shows an exploded view of the sheet metal stack 32. The sheet metal stack 32 has two outer sheets 34 and an inner sheet 36, which is arranged between the outer sheets 34. In the assembled pliers 10, the sheets 34 and 36 are attached to one another, preferably welded together.

[0052] The plastic handle parts 28 of the first leg 12 are arranged on opposite sides of the sheet metal stack 32 when the pliers 10 are mounted. The handle parts 28 are fastened to one another by several press-fit pins 38 (see, for example, Figure 8D). The press-fit pins 38 are inserted through through-holes 40 formed in the sheet metal stack 32.

[0053] In the present embodiment, the second leg 14 also has a sheet metal package 42 as a supporting structure.

[0054] The clamping elements 22 and 24 each form a different electrode of the bipolar forceps 10. The electrodes can be subjected to high-frequency alternating current. If tissue is clamped between the clamping elements 22 and 24, the alternating current flows between the two electrodes and through the clamped tissue. This heats and seals the tissue. In this embodiment, the second leg 14 has an activation switch 66 for activating the alternating current. When the forceps 10 are closed, an activation structure 68 of the first leg 12 is pressed against the activation switch 66. The activation switch 66, and thus the alternating current, is thereby activated. Preferably, the activation switch 66 has a V-shaped notch. This prevents the activation structure 68 from slipping off the activation switch 66.

[0055] In the present embodiment, the pliers 10 have a stabilizing device 44 for stabilizing the pliers 10 against lateral forces. The stabilizing device 44 has a connecting rod 46, which is arranged on the proximal side of the pivot joint 16. Figure 7 shows a perspective view of the connecting rod 46. The connecting rod 46 has a first bearing structure 48 and a second bearing structure 50. The first bearing structure 48 is slidably and rotatably mounted on the first leg 12. The second bearing structure 50 is fixedly and rotatably mounted on the second leg 14.

[0056] The first bearing structure 48 has two first bearing pins 52, which project laterally from the connecting rod 46 in opposite directions. The first bearing pins 52 are slidably and rotatably mounted in a respective elongated guide structure 54 of the first leg 12. In this case, the guide structures 54 are formed by elongated holes 56 in the handle parts 28. The second bearing structure 50 has two second bearing pins 58, which project laterally from the connecting rod 46 in opposite directions.

[0057] In this embodiment, the connecting rod 46 is an injection-molded part made of plastic. The first bearing journals 52 and the second bearing journals 58 are monolithically formed with the connecting rod 46.

[0058] The connecting rod 46 stabilizes the clamp 10 against lateral forces. Specifically, a lateral force acting on the first leg 12 can be transferred into the connecting rod 46 via the first bearing structure 48. A lateral force acting on the second leg 14 can be transferred into the connecting rod 46 via the second bearing structure 50. The connecting rod 46 therefore prevents the legs 12 and 14 from twisting relative to each other due to lateral forces.

[0059] The connecting rod 46 is arranged on the first leg 12 and on the second leg 14 such that the first bearing structure 48 is pushed away from the pivot joint 16 when the pliers 10 are closed. Thus, when the pliers 10 are closed, the first bearing structure 48 is pushed in a proximal direction towards the user. Conversely, when the pliers 10 are opened, the first bearing structure 48 is pushed away from the user in the opposite distal direction.

[0060] As mentioned previously, Figure 2 shows the open pliers 10, i.e., the maximum opening state of the pliers 10. When the pliers 10 are open, the first bearing structure 48 rests against a limit stop 60 of the first leg 12 (see, for example, Figure 8A). In this case, the limit stop 60 is formed by one end of the guide structure 54. The contact of the first bearing structure 48 against the limit stop 60 prevents further movement of the first bearing structure 48 in the distal direction. The connecting rod 46 thus prevents the pliers 10 from opening beyond the maximum opening state, so that the connecting rod 46 defines the maximum opening state.

[0061] In the present embodiment, the connecting rod 46 has a longer main arm 62 and a shorter secondary arm 64, which is angled relative to the main arm 62. When the clamp 10 is closed (see, for example, Figures 3 and 8C), the main arm 62 rests against the second leg 14 along its longitudinal extent. When the clamp 10 is closed, the secondary arm 64 bridges the gap between the main arm 64 and the guide structure 54.

[0062] In the present case, the second leg 14 has an elongated recess 118 in which the connecting rod 46, in particular the main arm 62, rests when the clamp 10 is closed. The recess 118 is bounded by two opposing side flanks 120, whereby only one of the side flanks 120 is always visible in the sectional views. Preferably, the connecting rod 46, in particular the main arm 62, rests in the recess 118 without play when the clamp 10 is closed.

[0063] The connecting rod 46 has two opposing sides

[0064] The side flanks 122 of the connecting rod 46 are located on the vise 10. When the vise 10 is closed, each side flank 122 of the connecting rod 46 faces a different side flank 120 of the recess 118. The side flanks 118 thus limit lateral movement of the connecting rod 46. Preferably, the side flanks 122 of the connecting rod 46 are convex. Due to the convex shape of the side flanks 122, the connecting rod 46 is securely guided into the recess 118 when the vise 10 is closed.

[0065] The forceps 10 also has a cutting unit 70, which is slidably mounted along a sliding axis between a proximal position and a distal position. The cutting unit 70 can cut tissue clamped and, in particular, sealed between the clamping elements 22 and 24.

[0066] The cutting unit 70 has a blade 72 (see Figure 6) with a cutting edge 74. The cutting edge 74 is arranged on a distal end face of the cutting unit 70 or the blade 72. In this embodiment, the blade 72 is slidably mounted between the outer sheets 34 of the sheet metal stack 32. The inner sheet 36 has a recess in the area of ​​the blade 72.

[0067] The cutting unit 70 also has a rack 76 (see, for example, Figure 8A) with a rack thread 78. The function of the rack 76 and the rack thread 78 will be explained in more detail later. The rack 76 can be formed monolithically with the blade 72 or attached to the blade 72.

[0068] The proximal position of the cutting unit 70 (see, for example, Figures 6 and 8A) is the retracted position or starting position of the cutting unit 70. To perform a cutting operation, the cutting unit 70 is pushed from the proximal position to the distal position (see Figure 8C). In the distal position, the cutting edge 74 is located in the area of ​​the clamping arrangement 20 between the clamping elements 22 and 24. The pliers 10 also have a user-operated drive unit 80. The drive unit 80 is slidably mounted on the first leg 12 along a further sliding axis, which is aligned parallel to the sliding axis of the cutting unit 70. The cutting unit 70 is coupled to the drive unit 80 in such a way that the cutting unit 70 is moved in the opposite direction when the drive unit 80 is moved.A cutting operation can therefore be carried out by pushing the drive unit 80 in a proximal direction, i.e., towards the user. The cutting unit 70 is then pushed in the opposite distal direction, i.e., away from the user. To facilitate the actuation of the drive unit 80, at least one trigger 82 is attached to the drive unit 80, projecting laterally from the first leg 12.

[0069] In this embodiment, the cutting unit 70 is motionally coupled to the drive unit 80 by a gear unit 116. The gear unit 116 is formed by the previously mentioned rack thread 78 of the cutting unit 70, by a rack thread 84 of the drive unit 80, and by a gear 86 that meshes with both the rack thread 78 and the rack thread 84.

[0070] The pliers 10 also have a return mechanism 88 for returning the cutting unit 70 from the distal position to the proximal position. The return mechanism 88 comprises a return element 90, which is displaceably arranged on the first leg 12 and is operatively connected to the second leg 14 such that the return element 90 is displaced along the first leg 12 by opening the pliers 10 and exerts a return force on the cutting unit 70, which moves the cutting unit 70 from the distal position to the proximal position. In this embodiment, the return element 90 is formed by the connecting rod 46, in particular by its first bearing structure 48. If the cutting unit 70 is in the distal position, then the connecting rod 46 applies the restoring force to the cutting unit 70 when the pliers 10 are opened.

[0071] In this case, the return element 90, i.e., the connecting rod 46, indirectly applies the return force to the cutting unit 70. The return element 90 does not come into direct contact with the cutting unit 70 when it is reset. Instead, the return element 90 transmits the return force to the cutting unit 70 via the drive unit 80. This can be seen, for example, in Figure 8D.

[0072] The return element 90 can also be implemented in other ways. For example, the return element 90 can also be part of a cable pull arrangement.

[0073] Preferably, the return mechanism 88, in addition to the return element 90, has a return spring 93 which applies a spring force to the cutting unit 70, thereby forcing the cutting unit 70 into the proximal position. The return spring 93 can be seen in Figure 6. In this case, a first end of the return spring 93 is attached to a projection 92 of the inner sheet 36 and a second end of the return spring 93 is attached to a projection 94 of the rack 76 (see Figure 6).

[0074] The pliers 10 also have a locking element 96, which is pivotably mounted on the first leg 12 between a locking position and a release position. In this case, the pivot axis of the locking element 96 is parallel to the pivot axis 18 of the pivot joint 16. In the locking position, the locking element 96 prevents the cutting unit 70 from moving from the proximal position towards the distal position. This can be seen, for example, in Figure 8A. In the release position, the cutting unit 70 can move from the proximal position towards the distal position. This can be seen, for example, in Figure 8B. Consequently, cutting operations can be performed when the locking element 96 is in the release position. In this case, the locking element 96 is pivotably mounted on one of the press-fit pins 38.

[0075] To pivot the locking element 96 from the locked position to the release position, the pliers 10 have a release mechanism 98. The release mechanism 98 comprises a release element 100, which is displaceably arranged on the first leg 12 and is operatively connected to the second leg 14 such that the release element 100 is displaced along the first leg 12 by closing the pliers 10 and exerts a release force on the locking element 96, which pivots the locking element 96 from the locked position to the release position.

[0076] In this embodiment, the release element 100 is formed by the connecting rod 46, in particular by its first bearing structure 48. Thus, when the pliers 10 are closed, the connecting rod 46 exerts the release force on the locking element 96, which pivots the locking element 96 from the locked position to the release position.

[0077] The release element 100 can also be implemented in other ways. For example, the release element 100 can also be part of a cable pull arrangement.

[0078] In this embodiment, the pliers 10 comprise an elastically deformable element 102, in this case an elastically deformable spring unit 102, which exerts a spring force on the locking element 96 in the release position, forcing the locking element 96 from the release position into the locked position. If the release element 100, i.e., the connecting rod 46, does not obstruct such a pivoting movement, the spring force causes the locking element 96 to pivot back from the release position into the locked position in order to re-lock the cutting unit 70.

[0079] In this embodiment, the locking element 96 is a waterjet-cut part made of a metal material. The spring unit 102 is monolithically formed with the locking element 96. In this case, the spring unit 102 is formed by a meandering extension of the locking element 96. An end section of the spring unit 102 facing away from the locking element 96 is held between two press-fit pins 38.

[0080] When the locking element 96 is in the locked position and the cutting unit 70 is in the proximal position, the locking element 96 and the cutting unit 70 are connected to each other by a permanent locking connection. For this purpose, the locking element 96 has a locking hook 104 which, in the locked position, engages behind a locking projection 106 of the cutting unit 70, thereby forming the locking connection.

[0081] In this case, the locking connection can be formed with the locking element 96 in the locked position by moving the cutting unit 70 into the proximal position. For this purpose, the cutting unit 70 and the locking element 96 each have a contact surface 108 or 110, respectively, oriented obliquely to the sliding axis of the cutting unit 70. When the cutting unit 70 is moved into the proximal position, the contact surfaces 108 and 110 come into contact with each other. The locking element 96 is thereby pivoted in the direction of the release position and thus moves out of the way of the cutting unit 70.

[0082] In this embodiment, the pliers 10 also include a snap disc spring 112, which can be actuated by pivoting the locking element 96 into the release position. When the snap disc spring 112 is actuated, it snaps into place, generating feedback that is audible and / or haptic to the user of the pliers 10. In this embodiment, the locking element 96 has an actuating arm 114 for actuating the snap disc spring 112. The actuating arm 114 can be pressed against the snap disc spring 112 by pivoting the locking element 96 into the release position.

[0083] The function of the pliers 10 is explained again in detail below with reference to figures 8A to 8G.

[0084] Initially, the pliers 10 are in the maximum opening position, in which the first bearing structure 48 rests against the limit stop 60. The cutting unit 70 is in the proximal position and is locked by the locking element 96. This is shown in Figure 8A.

[0085] When the pliers 10 are closed, the first bearing structure 48 is displaced along the guide structure 56 in the proximal direction. Upon sufficient proximal displacement, the connecting rod 46 applies the release force to the locking element 96. This causes the locking element 96 to pivot into the release position by bending the spring unit 102, and the snap disc spring 112 is actuated by the actuating arm 114. This can be seen in Figure 8B.

[0086] The cutting unit 70 is now released and can be moved from the proximal position to the distal position, as shown in Figure 8C. A proximal end of the drive unit 80 is now operatively connected to the first bearing structure 48 of the connecting rod 46. When the pliers 10 are opened from this position, the connecting rod 46 applies a restoring force to the cutting unit 70 via the drive unit 80, pushing the cutting unit 70 from the distal position towards the proximal position. In addition, the locking element 96 is pivoted into the locking position by the spring unit 102. This is shown in Figure 8D.

[0087] Because the displacement of the first bearing structure 48 is limited by the limit stop 60, the cutting unit 70 is not pushed into the proximal position by the first bearing structure 48. However, the return spring 93 ensures that the cutting unit 70 returns to the proximal position.

[0088] Figure 8E shows how the contact surface 108 of the cutting unit 70 engages the contact surface 110 of the locking element 96. Due to the alignment of the contact surfaces 108 and 110, the locking element 96 is pivoted out of the locked position (see Figure 8F). When the cutting unit 70 is in the proximal position, the locking hook 104 of the locking element 96 engages behind the locking projection of the cutting unit 70 (see Figure 8G). The cutting unit 70 is then locked again.

Claims

Patent claims 1. Electrosurgical bipolar forceps (10) comprising: a first arm (12) and a second arm (14), wherein the arms (12, 14) are pivotably mounted relative to one another by a pivot joint (16), wherein the forceps (10) has on a distal side of the pivot joint (16) a clamping arrangement (20) with a first clamping element (22) forming a first electrode and a second clamping element (24) forming a second electrode, and wherein the forceps (10) has on a proximal side of the pivot joint (16) a handle arrangement (26) for handling the forceps (10) by a user, and a stabilizing device (44) for stabilizing the forceps (10) against lateral forces, wherein the stabilizing device (44) has a connecting rod (46) arranged on the proximal side of the pivot joint (16), and wherein the connecting rod (46) a first bearing structure (48) which is slidably and rotatably mounted on the first leg (12),and has a second bearing structure (50) which is rotatably mounted on the second leg (14).

2. Electrosurgical bipolar forceps (10) according to claim 1, characterized in that the first bearing structure (48) has at least one, in particular cylindrical, first bearing pin (52) which is slidably and rotatably mounted on or in an elongated guide structure (54) of the first leg (12).

3. Electrosurgical bipolar forceps (10) according to claim 2, characterized in that the guide structure (54) is an elongated hole (56) formed in the first leg (12).

4. Electrosurgical bipolar forceps (10) according to one of the preceding claims, characterized in that the second bearing structure (50) has at least one, in particular cylindrical, second bearing pin (58) which is rotatably mounted on the second leg (14).

5. Electrosurgical bipolar forceps (10) according to one of claims 2 to 4, characterized in that the at least one first bearing pin (52) and / or the at least one second bearing pin (58) are monolithically formed with the connecting rod (46).

6. Electrosurgical bipolar forceps (10) according to one of the preceding claims, characterized in that the connecting rod (46) is an injection-molded part, in particular made of plastic.

7. Electrosurgical bipolar forceps (10) according to one of the preceding claims, characterized in that the connecting rod (46) is mounted on the first leg (12) and on the second leg (14) such that the first bearing structure (48) of the connecting rod (46) is pushed away from the pivot joint (16) by closing the forceps (10).

8. Electrosurgical bipolar forceps (10) according to one of the preceding claims, characterized in that the forceps (10) have a maximum opening state, and that the connecting rod (46) prevents the forceps (10) from opening beyond the maximum opening state.

9. Electrosurgical bipolar forceps (10) according to the preceding claim, characterized in that the first arm (12) , in particular the guide structure (54) , has a limit stop (60), and that the first bearing structure (48) is in contact with the limit stop (60) in the maximum opening state.

10. Electrosurgical bipolar forceps (10) according to one of the preceding claims, characterized in that the second arm (14) has an elongated recess (118), and that the connecting rod (46) lies in the recess (118) when the forceps (10) are closed, in particular without play.

11. Electrosurgical bipolar forceps (10) according to the preceding claim, characterized in that the recess (118) has at least one convexly shaped side flank (120), and / or that the connecting rod (46) has at least one convexly shaped side flank (122).

12. Electrosurgical bipolar forceps (10) according to one of the preceding claims, characterized in that one of the arms (14) has an activation switch (66) for activating the forceps (10), wherein the other arm (12) has an activation structure (68) which can be pressed against the activation switch (66) by closing the forceps (10).

13. Electrosurgical bipolar forceps (10) according to one of the preceding claims, characterized in that the connecting rod (46) has a longer main arm (62) and a shorter secondary arm (64) along its longitudinal extent, which is oriented at an angle to the main arm (62), wherein, when the forceps (10) are closed, the main arm (62) rests against the second leg (14) along its longitudinal extent and the secondary arm (64) bridges a gap between the main arm (62) and the first leg (12), in particular the guide structure (54) of the first leg (12).

14. Electrosurgical bipolar forceps (10) according to one of the preceding claims, characterized in that the forceps (10) has a cutting unit (70) with a cutting edge (74) for cutting tissue clamped by the clamping arrangement (20), wherein the cutting unit (70) is displaceably mounted, in particular on the first leg (12), between a proximal position and a distal position, and wherein the cutting unit (70) is displaceable from the proximal position to the distal position at least when the forceps (10) are closed in order to carry out a cutting operation.

15. Electrosurgical bipolar forceps (10) according to the preceding claim, characterized in that the cutting unit (70) can be subjected to a restoring force by opening the forceps (10) by means of the connecting rod (46), in particular by means of the first bearing structure (48) of the connecting rod (46), which displaces the cutting unit (70) from the distal position in the direction of the proximal position.

16. Electrosurgical bipolar forceps (10) according to one of claims 14 and 15, characterized in that the forceps (10) has a locking element (96) which is pivotably mounted on the first leg (12) between a locking position and a release position, wherein the locking element (96) in the locking position prevents displacement of the cutting unit (70) from the proximal position towards the distal position and releases it in the release position, and wherein the locking element (96) can be subjected to a release force by closing the forceps (10) by means of the connecting rod (46), in particular by means of the first bearing structure (48) of the connecting rod (46), which pivots the locking element (96) from the locking position to the release position.

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