SURGICAL INSTRUMENT AND METHOD FOR ITS DIVISION

Description

[0001] The invention relates to a surgical instrument and a method for disassembling it.

[0002] Numerous surgical instruments are known from current technology that allow a surgical tool, such as an endoscope, forceps, or similar device, to be attached to a shaft. After the operation or treatment of the patient, the surgical instrument must be properly cleaned, and for this purpose, the tool and shaft must be separated. This disassembly is often a complex process.

[0003] Such a surgical instrument is known, for example, from DE 197 07 373 C1; there, a bayonet coupling provides a detachable connection between two tubular shaft instruments or instrument parts.

[0004] Based on this prior art, the object of the present invention is to provide a surgical instrument that is improved with regard to the separation and joining of tool and shaft, because it is more user-friendly and simpler.

[0005] This problem is solved by a surgical instrument having the features of claim 1.

[0006] Preferred embodiments of the surgical instrument are described in the dependent claims.

[0007] The next task involves creating an improved disassembly method for such surgical instruments.

[0008] This problem is solved by the method with the features of independent claim 6.

[0009] According to a first embodiment of the surgical instrument according to the invention, it has a shaft at the distal end of which a tool is detachably held. A pull rod is arranged longitudinally within the shaft to move the tool.

[0010] The drawbar is surrounded distally by a forked element and proximally by the shaft. The forked element has an end section on its side facing the shaft. Adjacent to or near the proximal end of the forked element, the shaft has at least one undercut. The shaft has a shoulder on its side facing the forked element, from which an end section with a reduced diameter extends, the end section having at least one recess. The inner diameter of the shaft is widened along a distal part of the end section. An elongated spring plate is inserted into the at least one recess of the shaft, the spring plate having a radially inwardly projecting locking lug at its end facing the forked element. The locking lug engages with the at least one undercut of the forked element.The drawbar has a circumferential thickening of its diameter on the section in front of the proximal end of the fork element, and the spring plate has a transverse rib that points towards the drawbar and lies between the end of the fork element and the circumferential thickening of the drawbar.

[0011] In this context, "distal-side" always means far from the operator, regardless of whether the operator is a human or a machine, i.e., a robot. The opposite is true for "proximal-side."

[0012] The device according to the invention advantageously provides a locking connection, wherein the locking lug, which is resiliently designed by the spring plate, engages in the undercut of the fork element in a mounting arrangement of the surgical instrument.

[0013] The fork element and shaft are securely guided against each other and structurally locked against rotation, allowing for easy disassembly of the shaft by applying pressure to the pull rod at the proximal end and sliding it distally. The thickened diameter of the pull rod acts on the crossbar of the spring plate and pushes the locking lug radially outwards.

[0014] The pull rod reaches an over-open position, which is evident from the increased opening angle of, for example, the jaws of the tool, and moves the spring-loaded locking lug outwards from the undercut of the fork element. This movement also moves the fork element out of the shaft. A twisting motion, as is common with bayonet connections known from the prior art, is advantageously unnecessary, making disassembly very simple; the same applies to assembly: The tool, for example, a pliers insert, is simply inserted axially into the shaft from the distal side with its distal end in a non-use position (in the case of pliers inserts, this would be closed pliers) and is gripped by the locking lug of the spring plate. The spring-loaded locking lug essentially springs into the undercut on the fork element due to its preload. The connection is thus secured directly from the outset.

[0015] When released, the opposite effect is easily achieved by creating the aforementioned over-open position, which disengages the locking lug from the undercut. This is accomplished by the axial force exerted on the pull rod by the proximal pressure, causing the thickened diameter of the pull rod to act on the transverse rib of the spring plate and push the locking lug radially outwards.

[0016] In a preferred embodiment of the surgical element according to the invention, the fork element has a shoulder from which the end section extends with a reduced diameter - thus a fork element can be realized whose attachable tool part has the same outer diameter as the fork element.

[0017] In a further preferred embodiment of the surgical element according to the invention, the end section of the fork element has two undercuts arranged on opposite sides of the cylindrical end section. Correspondingly, the end section of the shaft has two recesses, each containing a spring plate, so that in this variant there are two spring plates whose locking lugs engage in the two undercuts of the fork element. The two combinations of recess, spring plate, and undercut are arranged in a mounting configuration on opposite sides of the pull rod, thus achieving a stable component connection.

[0018] At least one recess in the shaft can be designed in the form of an elongated slot. This recess can be open at one end or closed at the other (essentially a recess with a closed border). It replicates the shape of the spring plate(s) and guides the radial outward movement of the locking lug when the shaft is disassembled from the tool.

[0019] In yet another embodiment of the surgical instrument according to the invention, the recess of the shaft has a section on its proximal side in which a bearing surface for a proximal end of the spring plate to be inserted is formed. The spring plate is simply placed onto the bearing surface or can be glued, screwed, welded or otherwise fastened.

[0020] The circumferential thickening of the drawbar can be annular, spherical, or conical. It is also possible that the thickening of the drawbar is only present in the sections adjacent to the spring plate(s). The transverse rib of the spring plate has a shape corresponding to the circumferential thickening, so that the circumferential thickening of the drawbar can interact directly with the transverse rib of the spring plate when the drawbar is moved distally to disassemble the surgical instrument. The transverse rib of the spring plate can be an attached rib, a material thickening directed towards the fork element, an inclination of the spring plate, or a bend incorporated within it.

[0021] Typically, a tool mechanism is operatively connected to the tool at one end distally and to the drawbar at the other proximally, enabling the tool to be moved via the drawbar. The tool is connected to the shaft via the fork element, so the drawbar is connected to the tool mechanism and the tool itself, and then to the fork element. The tool, for example, the jaws, is / are mounted in the fork element, which is rigidly connected to the shaft. The drawbar extends axially and rotatably through the shaft into the fork element, connecting to the mechanism that holds the jaws.

[0022] In a further embodiment of the surgical instrument according to the invention, two guide rail elements can extend along the end section of the fork element, while at least one undercut(s) is located adjacent to the end of the fork element. Two guide rail elements extend along the end section of the shaft from its distal end towards the shoulder. The two guide rail elements of the shaft slidably interact with the guide rail elements of the fork element, thus advantageously supporting the torsional stability of the fork element and shaft.

[0023] In yet another embodiment of the surgical instrument according to the invention, the guide rail elements of the shaft are recesses or ribs and are designed to correspond and interact with the guide rail elements of the fork element, which are ribs, recesses, or grooves. This type of guide rail element provides good linear guidance of the fork element and the end section of the shaft, both during disassembly and assembly of the surgical instrument.

[0024] Finally, in yet another embodiment of the surgical instrument according to the invention, the guide rail elements of the shaft are arranged offset from each other by 90 degrees relative to the recesses of the shaft. This arrangement offers good stability during disassembly and assembly.

[0025] In a further embodiment of the surgical instrument according to the invention, a retaining tube is arranged around the end section of the fork element and around the end section of the shaft in an assembled state. The retaining tube further comprises at least one, preferably two, closed recesses that lie above the recess(s) of the end section of the shaft when all components are in an assembled arrangement, i.e., when the locking lug of the respective spring plate engages in the respective undercut. The closed recess of the retaining tube overlaps only a partial area with that of the end section of the shaft and terminates before the bearing surface for the proximal ends of the respective spring plate. Because the retaining tube covers this section, the spring plate is secured against falling out. The closed recess of the retaining tube provides additional guidance for the linear movement of the spring plate.

[0026] A method according to the invention for disassembling a surgical instrument according to the invention comprises the steps Apply pressure to the drawbar in an axial direction at the proximal end of the drawbar and move the drawbar distally, thereby moving the circumferential thickening of the drawbar against the transverse web of the at least one spring plate and into an over-open position of the drawbar, thereby moving the locking lug radially outwards out of the at least one undercut of the fork element and releasing the tool by loosening the connection between the fork element and the shaft.

[0027] Since the fork element is inserted linearly into the end section of the shaft during assembly of the surgical instrument, the linear movement of the pull rod in the distal direction simultaneously ensures complete and therefore simple disassembly of the components. The reverse applies to assembly, as already described. In an alternative embodiment of the method, tension can also be applied to the pull rod to effect the disassembly of the components.

[0028] Further embodiments, as well as some of the advantages associated with these and other embodiments, will become clearer and more easily understood through the following detailed description with reference to the accompanying figures. Objects or parts thereof that are essentially the same or similar may be provided with the same reference numerals. The figures are merely a schematic representation of one embodiment of the invention. The features that can be derived from the description and the drawings can be applied individually or in any combination according to the invention without departing from the scope of this disclosure. Further advantages will become apparent from the following description of the drawings. The drawings illustrate an exemplary embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination.The expert will expediently consider the features individually and combine them into meaningful further combinations.

[0029] This shows: Fig. 1 a schematic view of the surgical instrument according to the invention, Fig. 2 a sectional view of the shaft with pull rod and mounted fork element, and Fig. 3 a perspective exploded view of the components of the connection between the fork element and the shaft of the surgical instrument with internal pull rod.

[0030] In Fig. 1 The figure shows a surgical instrument 1 with a shaft 2 that is arranged proximally on a handle 10. The handle 10 is shown as an example in this figure; a differently designed handle or, for example, a robotic arm can also be used. Distally, the shaft 2 is connected to a tool 101, which can be replaced. The tool is detachably mounted, allowing the surgical instrument 1 to be easily disassembled.

[0031] As mentioned in Fig. 2 and 3 As shown, a longitudinally movable pull rod 3 for moving the tool 101 is arranged inside the shaft 2. At its proximal end, the pull rod 3 can be connected to the handle 10 (not shown in the figure).

[0032] The drawbar 3 is surrounded in a distal end section by a fork element 4, both of which are cylindrical. The fork element 4 has an inner bore 45 whose inner diameter corresponds to the outer diameter of the drawbar 3, so that the drawbar 3 passes through the fork element 4. "Correspondingly" here means that the inner bore 45 is dimensioned slightly larger than the outer diameter of the drawbar 3, so that the drawbar 3 can be moved linearly. The fork element 4 has a shoulder 41 on its side facing the shaft 2, from which an end section GE extends (in a proximal direction). Fig. 2 The end section GE has a reduced outer diameter and has two undercuts 43 adjacent to its end 44, in which the outer diameter is further reduced. The end 44 of the end section GE is thickened again, so that two in the longitudinal section of the Fig. 2 Visible rectangular recesses, the undercuts 43, are formed. The end 44 of the end section GE is chamfered to facilitate the guidance of the fork element 4 into the shaft 2. The shaft 2, on the other hand, has a first shoulder 21 on its side facing the fork element 4. From this shoulder 21, an end section SE of the shaft 2 with a reduced diameter extends distally. Along the end section SE of the shaft 2, two closed recesses 22 extend, which are elongated, as shown in particular in Fig. 3 The shaft 2 has a second shoulder 23, from which the outer diameter of the shaft 2 decreases and a bearing surface 24 is formed. An elongated spring plate 5 is inserted into each recess 22 of the shaft 2, with a proximal end 53 of the spring plate 5 resting on the bearing surface 24. Each spring plate 5 has a radially inwardly projecting locking lug 51 at its end facing the fork element 4, which Fig. 2 each engages with one of the undercuts 43 of the fork element 4.

[0033] The drawbar 3 has a circumferential, spherical thickening 31 of its diameter at the section located in front of the proximal end of the fork element 4. Correspondingly, each spring plate 5 has a transverse web 52 which, as shown in Fig. 2 shown, points radially inwards towards the drawbar 3 and lies between the end of the fork element 4 and the annular thickening 31 of the drawbar 3.

[0034] To allow the pull rod 3 to be inserted into the shaft 2 from the distal side for mounting the surgical instrument 1, the inner diameter of the shaft 2 is widened along a distal part of the end section SE. This widened inner diameter is larger than the outer diameter of the pull rod 3 at its circumferential thickening 31.

[0035] In Fig. 3 It is shown that two webs 42 extend axially along the end section GE of the fork element 4 in the proximal direction for linear guidance of the fork element 4 and the shaft 2. Correspondingly, two recesses 23 extend along the end section SE of the shaft 2 from its end towards the shoulder 21. The webs 42 and recesses 23 form guide rail elements of the shaft 2 and the fork element 4 and can be slid into one another like rails for assembly. The webs 42 on the fork element 4 and the recesses 23 on the shaft 2 are arranged offset by 90° from the recesses 22 of the shaft 2 and the spring plates 5, so that when the spring plates 5 engage in the undercuts 43 during assembly of the surgical instrument 1, they are held stably from two sides, and no rotation of the components relative to each other can occur.

[0036] A sleeve 6 is arranged around the end section GE of the fork element 4 and around the end section SE of the shaft 2. The sleeve 6 has two closed recesses 61 which lie over the closed recesses 22 of the end section SE of the shaft 2 when all components are in an assembly arrangement, as shown. Fig. 2 It shows. The closed recesses 22 of the over-tube 6 overlap only in a partial area with those of the end section SE of the shaft 2 and end before the bearing surface 24 for the proximal ends of the spring plates 5.

[0037] The present invention provides a surgical instrument 1 and a method for disassembling it. The surgical instrument 1 has a shaft 2, at the distal end of which a tool 101 is detachably held, and a pull rod 3 arranged in the shaft 2 and longitudinally movable therein for moving the tool 101. The pull rod 3 is surrounded distally by a fork element 4 and proximally by the shaft 2. The fork element 4 has an end section GE with a reduced diameter on its side facing the shaft 2, with at least one undercut 43 adjacent to one end of the end section GE. Furthermore, the shaft 2 has a first shoulder 21 on its side facing the fork element 4, from which an end section SE with a reduced diameter extends.At least one recess 22 extends along the end section SE, and an inner diameter of the shaft 2 is widened along a distal part of the end section SE. An elongated spring plate 5 is inserted into the recess 22 of the shaft 2, the spring plate having a radially inwardly projecting locking lug 51 at its end facing the fork element 4, which engages with the undercut 43 of the fork element 4. The drawbar 3 has a circumferential thickening 31 of diameter at its section located in front of the proximal end of the fork element 4. The spring plate 5 has a transverse web 52 that points toward the drawbar 3 and lies between the end of the fork element 4 and the circumferential thickening 31 of the drawbar 3. The drawings, the description, and the claims contain numerous features in combination. It is advantageous for a person skilled in the art to also consider the features individually and combine them into meaningful further combinations. REFERENCE MARK LIST

[0038] 1 Surgical instrument 2 Shaft 21 Shoulder 22 Recess 23 Shoulder 24 Bearing surface 3 Pull rod 31 Circumferential thickening 4 Fork element 41 Shoulder 42 Web 43 Undercut 44 End 45 Inner bore 5 Spring plate 51 Detent lug 52 Crossbar 53 Proximal end 6 Cap tube 61 Recess 10 Handle 101 Tool GEEnd section fork element SEEnd section shaft

Claims

1. A surgical instrument (1) with a shaft (2), at the distal end of which a tool (101) is detachably held, and with a tension rod (3) which is arranged in the shaft (2) and is longitudinally movable therein for moving the tool (101), wherein the tension rod (3) is surrounded distally by a fork element (4), and is surrounded proximally by the shaft (2), wherein - the fork element (4) has, on its side facing the shaft (2), an end section (GE), adjacent to the end (44) of which there is at least one undercut (43), - the shaft (2) has, on its side facing the fork element (4), a first shoulder (21) from which an end section (SE) with reduced diameter extends, wherein at least one recess (22) extends along the end section (SE), and wherein an inner diameter of the shaft (2) is widened along a distal part of the end section (SE), and wherein into the at least one recess (22) of the shaft (2) is inserted an elongate spring plate (5), which, at its end pointing towards the fork element (4), has a radially inwardly pointing latching lug (51), which engages with the at least one undercut (43) of the fork element (4), and wherein the tension rod (3) has a circumferential thickened portion (31) of the diameter at its section lying in front of the proximal end of the fork element (4), and wherein the spring plate (5) has a transverse web (52) which points towards the tension rod (3) and lies between the end of the fork element (4) and the circumferential thickened portion (31) of the tension rod (3), and wherein the thickened portion (31) of the tension rod (3) acts on the transverse web (52) of the spring plate (5) such that it presses the latching lug (51) radially outwards.

2. The surgical instrument (1) according to claim 1, characterised in that - two guide rail elements extend along the end section (GE) of the fork element (4), - two guide rail elements extend along the end section (SE) of the shaft (2) from its end in the direction of the shoulder (21), wherein the two guide rail elements of the shaft (2) each interact displaceably with the guide rail elements of the fork element (4).

3. The surgical instrument (1) according to claim 2, characterised in that the guide rail elements of the shaft (2) are recesses (23) or webs, and in that, correspondingly for the interaction, the guide rail elements of the fork element (4) are webs (42) or recesses or grooves.

4. The surgical instrument (1) according to claim 2 or 3, characterised in that the guide rail elements of the shaft (2) are arranged offset by 90° relative to the at least one recess (22) of the shaft (2).

5. The surgical instrument (1) according to one of the preceding claims, characterised in that in the assembled state, a retaining sleeve (6) is arranged around the end section (GE) of the fork element (4) and around the end section (SE) of the shaft (2).

6. A method for disassembling a surgical instrument (1) according to one of claims 1 to 5, comprising the steps - exerting pressure on the tension rod (2) in the axial direction at the proximal end of the tension rod (2), thereby moving the tension rod (2) in the distal direction, - thus moving the circumferential thickened portion (31) of the tension rod (2) against the transverse web (52) of the spring plate (5) into an over-open position of the tension rod (2), thereby - moving the latching lug (51) radially outwards out of the undercut (43) of the fork element (4), and - by loosening the connection between the fork element (4) and the shaft (2), releasing the tool (101).