Electrosurgical bipolar forceps with a pivotally mounted locking element

Abstract

The invention relates to an electrosurgical bipolar forceps (10) comprising: a first arm (12) and a second arm (14) which are pivotably mounted relative to each other by a pivot joint (16); a cutting unit (70) which is slidably mounted on the first arm (12) between a proximal position and a distal position; a locking element (96) which is pivotably mounted on the first arm (12) between a locking position and a release position, wherein the locking element (96) in the locking position prevents the cutting unit (70) from moving from the proximal position towards the distal position;and a release mechanism (98) comprising a release element (100) which is displaceably arranged on the first leg and is operatively connected to the second leg in such a way that the release element is displaced along the first leg by closing the pliers and exerts a release force on the locking element which pivots the locking element from the locking position into the release position.

Description

[0001] The disclosure relates to an electrosurgical bipolar forceps for preparing, in particular grasping, cutting and / or sealing, tissue, especially vessels, in surgical applications.

[0002] Such an electrosurgical bipolar forceps typically comprises a first arm and a second arm, which are pivotally mounted relative to each other. On a distal side of the pivot joint, the forceps have a clamping arrangement 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.

[0003] The present disclosure is based on the objective of improving the user-friendliness of an electrosurgical bipolar forceps with a movable cutting unit.

[0004] This problem is solved by an electrosurgical bipolar forceps having the features of claim 1.

[0005] 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 ensures particularly safe handling of the pliers. However, the handle assembly can also be designed in other ways that allow the user to handle the pliers.

[0006] The pliers according to the invention also comprise a cutting unit with a cutting edge for cutting tissue clamped by the clamping arrangement. The cutting unit is slidably mounted on the first leg, in particular along a sliding axis, between a proximal position and a distal position. The cutting unit is slidable from the proximal position to the distal position to perform a cutting operation, at least when the pliers are closed, and in particular only when the pliers are closed. A cutting operation is thus performed by sliding the cutting unit from the proximal position to the distal position. Preferably, the cutting edge of the cutting unit is arranged on a distal end face, i.e., on an end face of the cutting unit facing away from the user during intended use of the pliers. Preferably, the sliding axis is oriented perpendicular to the pivot axis of the pivot joint.

[0007] The pliers according to the invention also comprise a locking element which 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. When the locking element is in the locking position, cutting operations are therefore prevented by the locking element. In the release position, however, the locking element allows the cutting unit to move from the proximal position towards the distal position, so that cutting operations can be carried out. Preferably, the pivot axis of the locking element is aligned parallel to the pivot axis of the pivot joint.

[0008] According to the invention, the pliers also include a release mechanism for pivoting the locking element from the locked position to the released position. The release mechanism comprises a release element that is movably arranged on the first leg. The release element is operatively connected to the second leg, particularly mechanically, such that closing the pliers causes the release element to be moved along the first leg, thereby applying a release force to the locking element that pivots it from the locked position to the released position. Thus, the locking element can be pivoted from the locked position to the released position simply by closing the pliers. The locking element can be operatively connected to the release element directly or indirectly, i.e., via at least one further element.

[0009] The inventors recognized that the claimed release mechanism could increase the user-friendliness of the pliers. Due to the claimed design of the release mechanism, the locking element pivots into the release position when the pliers are closed. The cutting unit is thus virtually automatically released for cutting operations when the pliers are closed. No additional unlocking by the user is required.

[0010] Preferably, the locking element is operatively connected to the release element in such a way that only the release force can be transmitted to the locking element by the release element, but not a force acting in the opposite direction to the release force. The locking element can then be pivoted from the locked position to the released position by the release element, but not from the released position to the locked position.

[0011] In some embodiments, the locking element is designed so that it does not project beyond the first leg in any pivot position towards the second leg. This reliably prevents unintentional manual unlocking of the cutting unit by the user.

[0012] In some preferred embodiments, the release element is formed by a connecting rod comprising a first bearing structure, which is slidably and rotatably mounted on the first leg, and a second bearing structure, which is rotatably mounted on the second leg. During opening and closing operations of the pliers, the first bearing structure of the connecting rod is displaced along the first leg, particularly within or on an elongated guide structure of the first leg. Furthermore, the first bearing structure is rotated relative to the first leg, and the second bearing structure is rotated relative to the second leg. The displacement of the first bearing structure along the first leg allows the release force to be transmitted to the locking element. The connecting rod also has the advantage of stabilizing the pliers against lateral forces.Within the scope of the disclosure, the term "lateral forces" refers to forces that act on the jaws of the pliers parallel to the pivot axis of the swivel joint and radially offset from the pivot axis of the swivel joint. Consequently, lateral forces can cause the jaws of the pliers to twist relative to each other. However, the connecting rod stabilizes the pliers against lateral forces and thus against twisting of the jaws. Preferably, the second bearing structure is fixedly arranged on the second jaw and rotatably mounted.

[0013] The release element can also be implemented in other ways. For example, the release element can also be formed by an element of a cable pulley system.

[0014] In some preferred embodiments, the pliers are provided with an elastically deformable element that applies a spring force to the locking element in the release position, forcing the locking element from the release position into the locked position. This ensures that the locking element can be pivoted back into the locked position to relock the cutting unit. Preferably, the elastically deformable element is a spring assembly.

[0015] The presence of the elastically deformable element is preferred because it ensures a particularly reliable return of the locking element to the locked position, especially regardless of the orientation of the pliers. However, the locking element can also be pivoted from the release position to the locked position in another way.

[0016] In some preferred embodiments, the locking element is manufactured by waterjet cutting. The locking element is thus a waterjet-cut part. Waterjet cutting allows for the precise production of even fine structures. Furthermore, waterjet cutting is suitable for processing a wide variety of materials. Alternatively, the locking element can also be manufactured by laser cutting or an etching process. Preferably, the locking element is made of a metallic material, particularly by waterjet cutting.

[0017] In some preferred embodiments, the elastically deformable element, in particular the spring unit, is formed monolithically with the locking element. By using a monolithic unit consisting of the locking element and the elastically deformable element, the number of components can be reduced, resulting in cost savings.

[0018] In some preferred embodiments, the elastically deformable element is formed by a meandering extension of the locking element. This allows for the creation of an elastically deformable element that exhibits sufficient flexibility for the desired movement of the locking element. Preferably, the monolithic unit consisting of the locking element and the meandering extension is manufactured by waterjet cutting. This allows for the precise formation of a suitable meandering extension. Furthermore, manufacturing by waterjet cutting has the advantage of low thermal stress, which has a positive effect on the spring action of the meandering extension.

[0019] In some preferred embodiments, the locking element is connected to the cutting unit by a detent in the locked position. This applies at least when the cutting unit is in the proximal position. Preferably, the detent is a permanent detent. A permanent detent exists when it cannot be released by applying a force to the cutting unit in a distal direction. The permanent detent, however, can be released by pivoting the locking element from the locked position to the release position. A permanent detent reliably prevents unwanted distal displacement of the cutting unit when the pliers are open.

[0020] In some preferred embodiments, the locking element is provided to have a detent hook. In the locked position, the detent hook engages behind a detent projection of the cutting unit to form the detent connection.

[0021] In some preferred embodiments, the locking connection between the cutting unit and the locking element can be formed by moving the cutting unit from the distal to the proximal position, even when the locking element is in the locked position. The locking connection can therefore still be formed even if the locking element is already in the locked position. Preferably, for this purpose, a contact surface of the locking element, which comes into contact with the cutting unit when the cutting unit is moved into the proximal position, and / or a contact surface of the cutting unit, which comes into contact with the locking element when the cutting unit is moved into the proximal position, are oriented obliquely to the sliding axis of the cutting unit. This causes the locking element to pivot out of the locked position and move out of the way of the cutting unit when the cutting unit is moved towards the proximal position.If the cutting unit is sufficiently displaced towards the proximal position, the locking element pivots back into the locking position, thereby forming the latching connection.

[0022] In some preferred embodiments, the pliers are provided with a snap-action spring that can be actuated by pivoting the locking element into the release position. A snap-action spring is a curved disc that deforms elastically under the influence of a force. As soon as the force exceeds a certain threshold, the snap-action spring snaps into place. This snapping action generates feedback that is audible and / or haptic to the user of the pliers. The snap-action spring thus provides the user with information regarding the pivot position of the locking element. For example, the snap-action spring is arranged and designed such that it snaps into place when the cutting unit is unlocked. Preferably, the snap-action spring is attached to the first leg of the pliers. Alternatively, the snap-action spring can also be attached to the locking element.

[0023] In some preferred embodiments, the locking element has an actuating arm that can be pressed against the snap disc spring by pivoting the locking element into the release position. Preferably, the actuating arm is formed monolithically with the base body of the locking element.

[0024] In some preferred embodiments, the first leg comprises a sheet metal stack as a support. Preferably, the sheet metal stack has two outer sheets and at least one inner sheet between the outer sheets. Such a sheet metal stack can be manufactured cost-effectively. Preferably, the sheets of the sheet metal stack are attached to one another, in particular welded together. Preferably, the first leg also has at least two handle parts made of plastic, which are arranged on opposite sides of the sheet metal stack. The sheet metal stack is thus arranged between the handle parts. The handle parts are attached to one another by several press-fit pins. The handle parts can improve the user-friendliness of the pliers. The press-fit pins can be inserted through through-holes formed in the sheet metal stack.

[0025] In some preferred embodiments, the locking element is pivotably mounted on one of the press-fit pins. This reduces manufacturing costs, as an existing component is used for mounting the locking element.

[0026] In some preferred embodiments, an end section of the elastically deformable element facing away from the locking element is held between two press-fit pins. This reduces manufacturing costs, as two existing components are used to support the elastically deformable element.

[0027] In some embodiments, the second leg is provided to have a sheet metal stack as a support.

[0028] 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, the same 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 figures are shown schematically: Fig. 1 A side view of an electrosurgical bipolar forceps with a first arm and a second arm; Fig. 2 a side view of the open pliers with the handle removed; Fig. 3 a side view of the closed pliers with the handle removed; Fig. 4 a side view of the supporting structures of the legs; Fig. 5 an exploded view of the supporting structure of the first leg; Fig. 6 the supporting structure of the first leg with a slidingly mounted blade; Fig. 7 a connecting rod of the pliers; and Fig. 8A-8G Detailed views of the pliers at different times during a cutting process.

[0029] Fig. Figure 1 shows a side view of an electrosurgical bipolar forceps 10. The forceps 10 have a first arm 12 and a second arm 14. The arms 12 and 14 are connected by a pivot joint 16 (see Figure 1). Fig. 2 to 4) are mounted to pivot about a pivot axis 18. The pliers 10 can be opened and closed by pivoting the arms 12 and 14. Fig. Figure 2 shows the maximum opening state of the pliers 10. Fig. Figure 3 shows the pliers 10 in the closed position.

[0030] 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.

[0031] 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.

[0032] Fig. Figure 4 shows a side view of the pliers 10 without the handle parts 28. In the present embodiment, the first leg 12 has a sheet metal stack 32 as a support structure. Fig. Figure 5 shows an exploded view of the lamination stack 32. The lamination stack 32 has two outer sheets 34 and an inner sheet 36, which is arranged between the outer sheets 34. In the assembled clamp 10, the sheets 34 and 36 are attached to one another, preferably welded together.

[0033] The plastic handle parts 28 of the first leg 12 are arranged on opposite sides of the sheet metal assembly 32 when the pliers 10 are mounted. The handle parts 28 are secured by several press-fit pins 38 (see, for example, the figure shown in ... Fig. 8D) are attached to each other. The press-fit pins 38 are inserted through through openings 40 formed in the sheet metal stack 32.

[0034] In the present embodiment, the second leg 14 also has a sheet metal package 42 as a supporting structure.

[0035] The clamping elements 22 and 24 each form a different electrode of the bipolar clamp 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 clamp 10 is closed, an activation structure 68 of the first leg 12 is pressed against the activation switch 66. This activates the activation switch 66 and thus the alternating current. Preferably, the activation switch 66 has a V-shaped notch. This prevents the activation structure 68 from slipping off the activation switch 66.

[0036] 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. Fig. Figure 7 shows a perspective view of connecting rod 46.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The connecting rod 46 stabilizes the clamp 10 against lateral forces. Specifically, a lateral force acting on the first leg 12 can be transferred to the connecting rod 46 via the first bearing structure 48. A lateral force acting on the second leg 14 can be transferred to 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.

[0041] 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.

[0042] As mentioned previously, it shows Fig. 2 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 e.g. Fig. 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 with the limit stop 60 prevents further displacement 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 position, so that the connecting rod 46 defines the maximum opening position.

[0043] 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, the figure shown in the illustration), 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. Fig. 3 and Fig. 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.

[0044] 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.

[0045] The connecting rod 46 has two opposing side flanks 122. When the clamp 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 clamp 10 is closed.

[0046] The forceps 10 also features a cutting unit 70, which is slidably mounted along a sliding axis between a proximal and a distal position. The cutting unit 70 allows the cutting of tissue clamped and, in particular, sealed between the clamping elements 22 and 24.

[0047] The cutting unit 70 has a blade 72 for this purpose (see Fig. 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 stack 32. The inner sheet 36 is recessed in the area of ​​the blade 72.

[0048] The cutting unit 70 also has a rack 76 (see e.g. Fig. 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.

[0049] The proximal position of the cutting unit 70 (see e.g. Fig. 6 and Fig. 8A) is the inserted position or starting position of the cutting unit 70. To perform a cutting operation, the cutting unit 70 is moved from the proximal position to the distal position (see Fig. 8C). The cutting edge 74 is positioned distally in the area of ​​the clamping arrangement 20 between the clamping elements 22 and 24.

[0050] 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 operation of the drive unit 80, at least one trigger 82 is attached to the drive unit 80, which projects laterally from the first leg 12.

[0051] 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.

[0052] The pliers 10 also have a reset mechanism 88 for resetting the cutting unit 70 from the distal position towards the proximal position. The reset mechanism 88 comprises a reset element 90, which is displaceably arranged on the first leg 12 and is operatively connected to the second leg 14 such that, when the pliers 10 are opened, the reset element 90 is displaced along the first leg 12 and exerts a reset force on the cutting unit 70, which moves the cutting unit 70 from the distal position towards the proximal position.

[0053] 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, the connecting rod 46 exerts the return force on the cutting unit 70 when the pliers 10 are opened.

[0054] In this case, the return element 90, i.e., the connecting rod 46, indirectly applies the return force to the cutting unit 70. Therefore, 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 is, for example, Fig. See it in 8D.

[0055] 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.

[0056] Preferably, in addition to the return element 90, the return mechanism 88 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 is in Fig. 6 can be seen. 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 to a projection 94 of the rack 76 (see Fig. 6).

[0057] The pliers 10 also have a locking element 96, which is pivotably mounted on the first arm 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 is, for example, Fig. 8A can be seen. In the release position, the movement of the cutting unit 70 from the proximal position towards the distal position is enabled. This is, for example, in Fig. 8B can be seen. Consequently, cutting operations can be carried out 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.

[0058] In order to pivot the locking element 96 from the locking position to the release position, the pliers 10 have a release mechanism 98.

[0059] 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 in such a way 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 locking position into the release position.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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 at an angle 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. This causes the locking element 96 to pivot towards the release position and thus move out of the way of the cutting unit 70.

[0066] 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.

[0067] The function of the pliers 10 will be described below using the following examples: Fig. 8A to 8G are explained again in a coherent manner.

[0068] Initially, the pliers 10 are in their maximum open 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 in Fig. 8A shown.

[0069] 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 is in Fig. 8B can be seen.

[0070] The cutting unit 70 is now released and can be moved from the proximal position to the distal position, as shown in Fig. Figure 8C shows that a proximal end of the drive unit 80 is now in operative connection with the first bearing structure 48 of the connecting rod 46. When the pliers 10 are opened from this position, the connecting rod 46, via the drive unit 80, applies the restoring force to the cutting unit 70, 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 Fig. 8D shown.

[0071] Because the displacement of the first bearing structure 48 is limited by the limit stop 60, the cutting unit 70 is not pushed into its proximal position by the first bearing structure 48. However, the return spring 93 ensures that the cutting unit 70 returns to its proximal position.

[0072] In Fig. Figure 8E shows how the contact surface 108 of the cutting unit 70 contacts 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 8E). Fig. 8F). If 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 Fig. 8G). The cutting unit 70 is then locked again.

Claims

[1] Electrosurgical bipolar forceps (10), comprising: a first leg (12) and a second leg (14), wherein the legs (12, 14) are pivotably mounted to each other by means of a pivot joint (16), wherein the clamp (10) has a clamping arrangement (20) on a distal side of the pivot joint (16) with a first clamping element (22) forming a first electrode and a second clamping element (24) forming a second electrode, and wherein 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, a cutting unit (70) with a cutting edge (74) for cutting fabric clamped by the clamping arrangement (20), wherein the cutting unit (70) is slidably mounted on the first leg (12) between a proximal position and a distal position, 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 the cutting unit (70) from moving from the proximal position towards the distal position and releases it in the release position, and a release mechanism (98) for pivoting the locking element (96) from the locking position to the release position, wherein the release mechanism (98) has a release element (100) which is displaceably arranged on the first leg (12) and is operatively connected to the second leg (14) in such a way 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 locking position to the release position. [2] Electrosurgical bipolar forceps (10) according to claim 1, characterized by , that the release element (100) is formed by a connecting rod (46) which has a first bearing structure (48) which is slidably and rotatably mounted on the first leg (12) and a second bearing structure (50) which is rotatably mounted on the second leg (14). [3] Electrosurgical bipolar forceps (10) according to any one of the preceding claims, characterized by , that the pliers (10) have an elastically deformable element (102), in particular a spring unit (102), which applies a spring force to the locking element (96) in the release position, forcing the locking element (96) from the release position into the locking position. [4] Electrosurgical bipolar forceps (10) according to any one of the preceding claims, characterized by , that the locking element (96) is manufactured by waterjet cutting, in particular from a metal material. [5] Electrosurgical bipolar forceps (10) according to the preceding claim, characterized by , that the elastically deformable element (102) is formed monolithically with the locking element (96). [6] Electrosurgical bipolar forceps (10) according to the preceding claim, characterized by , that the elastically deformable element (102) is formed by a meandering extension of the locking element (96). [7] Electrosurgical bipolar forceps (10) according to any one of the preceding claims, characterized by , that the locking element (96) is connected to the cutting unit (70) in the locking position by a locking connection, in particular a non-removable one. [8] Electrosurgical bipolar forceps (10) according to the preceding claim, characterized by , that the locking element (96) has a locking hook (104) which, in the locking position, engages behind a locking projection (106) of the cutting unit (70) to form the locking connection. [9] Electrosurgical bipolar forceps (10) according to one of claims 7 and 8, characterized by , that the locking connection can be formed with the locking element (96) in the locking position by moving the cutting unit (70) from the distal position to the proximal position. [10] Electrosurgical bipolar forceps (10) according to any one of the preceding claims, characterized by , that the pliers (10) have a snap disc spring (112) which can be actuated by pivoting the locking element (96) into the release position. [11] Electrosurgical bipolar forceps (10) according to the preceding claim, characterized by , that the locking element (96) has an actuating arm (114) which can be pressed against the snap disc spring (112) by pivoting the locking element (96) into the release position. [12] Electrosurgical bipolar forceps (10) according to any one of the preceding claims, characterized by, that the first leg (12) has a sheet metal package (32) and at least two plastic handle parts (38) arranged on different sides of the sheet metal package (32), wherein the handle parts (32) are attached to each other by several press-fit pins (38). [13] Electrosurgical bipolar forceps (10) according to the preceding claim, characterized by , that the locking element (96) is pivotably mounted on one of the press-fit pins (38). [14] Electrosurgical bipolar forceps (10) according to one of claims 12 and 13, characterized by , that an end section of the elastically deformable element (102) facing away from the locking element (96) is held between two press-fit pins (38).

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