Surgical instrument with unlockable slider

Abstract

Surgical instrument (10) with: a base body (12) with a guide shaft (14) and a first handle branch (16) arranged at an angle to this, wherein the guide shaft (14) comprises a shaft guide (18); a slide (20) with a slide guide (22) which is designed to cooperate with the shaft guide (18) for the sliding bearing of the slide (20) on the guide shaft (14); a second handle branch (24) which is mounted on the base body (12) and is operatively connected to the slide (20) via a slide bearing (26) for transmitting an actuating force to the slide (20) in order to move the slide (20) relative to the guide shaft (14) in the direction of a distal end position; a return element (28) for generating a return force on the slide (20) opposite to the actuating force in order to return the slide (20) to a rest position relative to the guide shaft (14); and a limiting mechanism (30) for limiting a displacement of the slide (20) relative to the guide shaft (14) up to the rest position, wherein the limiting mechanism (30) comprises an actuating element (31) which, when actuated, allows a further displacement of the slide (20) in a proximal direction beyond the rest position, wherein the shaft guide (18) and the slide guide (22) cooperate to unlock the slide (20) when the slide (20) is pushed in a proximal direction beyond the rest position, so that the slide (20) can be released from the guide shaft (14) and remains connected to the second handle branch (24) via the slide bearing (26).

Description

[0001] The present invention relates to a surgical instrument and in particular a bone punch.

[0002] A bone punch is a surgical instrument used for precisely cutting, punching, or removing bone tissue. The instrument works on the principle of a punch, where a sharp cutting edge is forced through the bone tissue by force applied via a lever mechanism to create defined openings or cutouts.

[0003] Bone punches are primarily used in orthopedics and neurosurgery. In orthopedics, they are used to treat bone fractures, correct bone deformities, and prepare bone grafts. In neurosurgery, they are used to access the brain or spinal cord, for example, by removing sections of bone from the skull or spine. Other applications include traumatology, where they are used to treat complex fractures, and reconstructive surgery, where precise bone harvesting is required for transplantation.

[0004] This instrument enables surgeons to make controlled and reproducible cuts in hard bone tissue while preserving the surrounding soft tissue. The precision of the bone punch is particularly important in areas where millimeter-accurate cuts are required to protect critical anatomical structures.

[0005] Bone punches and comparable surgical instruments in terms of mechanical implementation have continuously evolved over the years to meet the requirements of modern medical procedures, especially with regard to the possibility of cleaning and ease of use for the user.

[0006] DE 202004017974 U1 discloses a surgical punching instrument with a fixed handle attached to a punching rail and an actuating lever pivotally mounted thereon. The instrument comprises a punching slide which is connected to the actuating lever via a short lever arm and is under the influence of a return spring. The punching slide rests with a flat sliding surface along its entire length on a flat guide surface of the punching rail and is guided axially along this rail by means of T-shaped profiled, interlocking guide elements that can be released by longitudinal displacement.The return spring, designed as a helical compression spring, is at least partially arranged and guided in a guide groove of the sliding surface of the punching slide by means of a guide shaft axially projecting through it, wherein a distal stop surface firmly connected to the punching slide is provided as a support bearing for the rear end of the return spring.

[0007] A further development of this technology is shown in DE 102009056099 A1, which describes a surgical instrument with a base part comprising a shaft and a fixed handle arm. A working part is slidably guided on the shaft, and a pivotable handle arm is arranged on the base part. The handle arm is pivotally mounted in an opening in the base part by means of a pivot pin that engages in a through-hole in the pivotable handle arm. To separate the pivotable handle arm from the working part, the pivot pin can be completely lifted axially out of the pivotable handle arm and is captive, thus remaining attached to the base part. The pivotable handle arm is captive, remaining attached to the base part, in the position separated from the working part.

[0008] The most recent development in this area is described in EP 3153115 A1, which describes a bone punch with a base consisting of a guide shaft and a handle attached to the guide shaft. The bone punch comprises a punching slide, which rests adjustably on an upper guide surface of the guide shaft, and an actuating lever, which is pivotally mounted between two spaced-apart side walls. The actuating lever forms an adjusting lever, via which it is operatively connected to the punching slide for its adjustment. The punching slide is guided longitudinally on the guide shaft by T-shaped profiled, interlocking guide elements that are releasable.The punching slide has a locking element in its distal end area, which, in the mounted state of the punching slide on the guide shaft, projects between the two side walls and has two laterally projecting positive locking elements, each side wall being provided with an inner longitudinal groove extending in the longitudinal direction of the guide shaft, distally limited, into which a positive locking element can be inserted in a longitudinally displaceable manner.

[0009] Despite these advances in the development of surgical instruments, and especially surgical punch instruments, challenges persist regarding their practical handling, cleaning, and maintenance. One problem lies in the complex disassembly of the instruments for cleaning purposes, as existing solutions often require multiple steps or specialized tools. This can lead to time losses in daily clinical practice and impair the efficiency of instrument reprocessing. Furthermore, in exceptional cases and with incorrect handling, the instruments may not be cleaned adequately.

[0010] Another problem is that with existing systems, separating components is often not intuitive, or components must be completely separated, which can lead to mix-ups or losses. This is particularly problematic in environments where several similar instruments are used and cleaned simultaneously.

[0011] In addition, existing solutions show weaknesses in terms of user-friendliness, as the unlocking mechanisms are often not ergonomically designed or require precise handling that is difficult to implement under time pressure or with limited visibility.

[0012] It was recognized that a surgical instrument was needed that could overcome one or more of these problems.

[0013] In one aspect, the present invention relates to solving this problem by providing a surgical instrument with a base body comprising a guide shaft and a first handle arm arranged at an angle to the guide shaft, wherein the guide shaft includes a shaft guide. The surgical instrument comprises a slide with a slide guide configured to interact with the shaft guide for the slidable mounting of the slide on the guide shaft. The instrument has a second handle arm mounted on the base body and operatively connected to the slide via a slide bearing for transmitting an actuating force to the slide in order to displace the slide relative to the guide shaft towards a distal end position.The surgical instrument includes a return element for generating a return force on the slide opposite to the actuating force, in order to return the slide to a rest position relative to the guide shaft. The instrument has a limiting mechanism for restricting movement of the slide relative to the guide shaft until it reaches the rest position. This limiting mechanism includes an actuating element which, when actuated, allows further movement of the slide in a proximal direction beyond the rest position. The shaft guide and the slide guide work together to unlock the slide when it has been moved proximal beyond the rest position, allowing the slide to be released from the guide shaft and remaining connected to the second handle branch via the slide bearing.

[0014] Preferred embodiments of the invention are described in the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention.

[0015] The surgical instrument according to the invention solves the problems of the prior art through an innovative unlocking mechanism that enables simple and intuitive disassembly for cleaning purposes. The limiting mechanism with its actuating element ensures that the slider can only be moved beyond its normal resting position by deliberate actuation, thus preventing unintentional disassembly during the surgical procedure.

[0016] The interaction of the shaft guide and slide guide enables controlled unlocking of the slide, which remains connected to the second handle branch via the slide bearing. This prevents the components from completely disassembling and reduces the risk of mix-ups or losses during instrument reprocessing.

[0017] The return mechanism ensures reliable retraction of the slide to its rest position after actuation and contributes to the ergonomic handling of the instrument. The combination of the main body with its angled first handle arm and swiveling second handle arm enables efficient force transmission for precise surgical procedures.

[0018] The innovative design of the instrument, with its form-fitting interlocking guide elements, ensures stable guidance of the slide during operation and safe unlocking when required, thereby optimizing both the functionality and ease of maintenance of the instrument.

[0019] In one embodiment, the actuating element comprises a push button. The actuating element includes a return spring for resetting the push button. The actuating element includes a stop element that is connected to the push button and mounted on the base body, and that interacts with a counter-stop element on the second handle arm. The stop element can be removed from the counter-stop element by actuating the push button. This embodiment offers a particularly user-friendly solution for unlocking the slide. The push button is an ergonomic actuating element that is easy to operate even under time pressure. The return spring ensures that the push button automatically returns to its initial position after actuation, thus preventing accidental continuous loading.The interaction of the stop element and the counter-stop element creates a reliable locking mechanism that is only released when the push button is deliberately pressed.

[0020] In one embodiment, the push button and the stop element are designed as sections of a cylindrical component. The stop element has a cross-section larger than that of an adjacent section. The cylindrical component can be, in particular, made of two parts, which can be screwed together. The push button can, in effect, be screwed onto a counterpart. This design solution enables a compact and robust construction of the actuating element. The cylindrical shape ensures even force distribution and precise guidance of the actuating element. The increased cross-section in the area of ​​the stop element creates a defined and rotationally secure stop surface, which guarantees reliable locking with the counter-stop element and simultaneously facilitates simple manufacturing.

[0021] In one embodiment, the shaft guide comprises a first profile and the slide guide comprises a second profile. In a first region, when the slide is between its distal end position and its rest position, the first and second profiles interlock positively to hold the slide on the guide shaft. In a second region, when the slide is extended proximally beyond its rest position, the first and second profiles do not interlock, allowing the slide to be released from the guide shaft. This profile design ensures secure guidance of the slide during normal operation through the positive engagement of the profiles in the first region. Simultaneously, the second region, where the profiles do not interlock, allows for controlled unlocking.This two-part profile design ensures that unlocking can only occur in a defined position, thereby increasing the safety and reliability of the instrument.

[0022] In one embodiment, the first or second profile has a projection with a T-shaped cross-section in a first region, which engages in a T-shaped recess on the other profile. The T-shaped profile design provides a particularly secure and stable connection between the slide and the guide shaft. The T-profile prevents the slide from lifting laterally off the guide shaft and ensures precise guidance even under high actuation forces. This proven profile shape also allows for easy assembly and disassembly by axial displacement.

[0023] In one embodiment, the second profile, in the region of a distal end of the slide, comprises two first guide elements projecting towards the first profile, forming a first cutout with a T-shaped cross-section. This arrangement of the first guide elements at the distal end of the slide ensures stable guidance within the instrument's working area. The two projecting guide elements together form the T-shaped cutout and ensure an even distribution of force on both sides of the profile. This increases the instrument's stability and precision during use.

[0024] In one embodiment, the second profile, located at the proximal end of the slide, comprises a second guide element projecting towards the first profile. This guide element has a second projection with a T-shaped cross-section and preferably simultaneously forms a first stop for the return element. The second guide element at the proximal end of the slide complements the guidance and ensures uniform force distribution and secure attachment along the entire length of the slide. This dual function as both a guide element and a stop for the return element allows for a compact design and reduces the number of components required. This simplifies the manufacturing and assembly of the instrument.

[0025] In one embodiment, the second profile, in the region of a proximal end of the slide, comprises a third guide element projecting towards the first profile. This guide element has a third projection with a T-shaped cross-section and preferably simultaneously forms a second stop for the return element. The third guide element reinforces the guidance in the proximal region of the slide and can serve as an additional stop for the return element. This arrangement enables precise positioning and guidance of the return element, thereby ensuring uniform force distribution and reliable return of the slide.

[0026] In one embodiment, the first profile has a projection extending towards the second profile at the distal end of the shaft, which engages in a groove of the second profile. This projection at the distal end of the shaft provides additional guidance and stabilization of the slide within the working area. The engagement with the groove of the second profile prevents lateral slippage and ensures precise alignment of the cutting edge or working element. This is particularly important for the accuracy of surgical procedures.

[0027] In one embodiment, the slide and guide shaft lie in contact with each other over a flat surface between a distal and a proximal section of the profiles. This flat contact between the profile sections ensures even force distribution and reduces point loads. This increases the instrument's service life and guarantees smooth and precise guidance of the slide. The flat contact also contributes to the instrument's stability under high actuation forces.

[0028] In one embodiment, the slide bearing on the second handle arm is designed as an elongated slot into which a fastening pin, mounted on the slide, engages. The elongated slot allows for defined movement of the slide when the second handle arm is actuated and simultaneously compensates for the pivoting movement of the handle arm. The fastening pin establishes a robust and reliable connection between the slide and the handle arm.

[0029] This arrangement ensures efficient power transmission and precise control of the slide movement.

[0030] In one embodiment, the return element comprises a spring, preferably a coil spring, which is particularly preferably arranged around a guide pin. The coil spring provides a uniform and reliable return force over the entire range of motion of the slide. The arrangement around a guide pin ensures precise guidance of the spring and prevents lateral deflection or tilting. This guarantees a constant return force and a long service life of the return element.

[0031] In one embodiment, the return element is arranged on the slide, preferably in the region of a proximal end of the slide. Arranging the return element on the slide enables a compact design and direct force transmission. Positioning it in the proximal region of the slide optimally utilizes the available installation space and allows for easy assembly and maintenance of the return element.

[0032] In one embodiment, the reset element is positioned in an area between the slide and the guide shaft and projects into recesses on both the slide and the guide shaft. This arrangement of the reset element ensures a protected position between the main components of the instrument. Projecting into the recesses of both components guarantees secure positioning and prevents the reset element from slipping or falling out. This contributes to the reliability and longevity of the instrument.

[0033] In one embodiment, the surgical instrument is designed as a punching instrument, preferably a bone punch. The instrument includes a cutting edge in the region of a distal end of the slide or guide shaft, with the cutting edge preferably being located on the slide. The design as a punching instrument or bone punch makes the instrument particularly suitable for orthopedic and neurosurgical procedures. The cutting edge on the slide enables precise cuts in bone tissue through the movement of the slide relative to the guide shaft. The arrangement of the cutting edge on the movable slide ensures a controlled cutting action and allows for precise application of the cutting force.

[0034] In one embodiment, a base body is understood to be a structural component suitable for supporting and connecting the main components of the surgical instrument. The base body can be made of a biocompatible material and forms the basic framework of the instrument.

[0035] In this context, a guide shaft is understood to be an elongated element suitable for enabling directed movement of the slide. The guide shaft may be equipped with guide elements that ensure precise guidance of the slide.

[0036] In this context, the term "first grip branch" refers to a handle suitable for holding and guiding the instrument. The first grip branch may be angled on the main body to allow for ergonomic handling.

[0037] In this context, a shaft guide is understood to be a guidance system suitable for directing the movement of the slide along the guide shaft. The shaft guide may include profiles or guide grooves.

[0038] In this context, a slide is understood to be a movable element suitable for performing a working function of the instrument. The slide may be provided with a cutting edge and be mounted to slide along the guide shaft.

[0039] In this context, a slide guide is understood to be a guide system suitable for interacting with the shaft guide and enabling controlled movement of the slide. The slide guide can have complementary profiles to the shaft guide.

[0040] In this context, a second handle arm is understood to be an actuating element suitable for transmitting force to the slider. The second handle arm can be pivotally mounted on the base body.

[0041] In this context, a slide bearing is understood to be a connecting device suitable for coupling the second handle branch to the slide.

[0042] The slide bearing can be designed as an elongated hole with a fastening pin.

[0043] In this context, a distal end position refers to the working position of the slide in which it is furthest from the user. In this position, the cutting edge can reach its maximum deflection and achieve the desired cutting action. The distal end position represents the position in which the slide has reached its greatest displacement in the working direction. A rest position, on the other hand, refers to the basic position of the slide in which the instrument is in a non-actuated state. In this position, the slide is held by the return element, and the instrument can be handled safely. The rest position is the starting position to which the slide automatically returns after actuation.

[0044] In this context, a proximal direction is defined as the direction towards the user of the instrument. Proximal movement means movement away from the working end of the instrument towards the handle. Moving the slider proximally beyond its rest position can activate the unlocking function. Distal movement, in this context, is defined as the direction away from the user towards the working end of the instrument. Distal movement means movement away from the handle towards the cutting edge or working element. Distal movement of the slider is achieved by actuating the second handle arm.

[0045] In this context, a return element is understood to be a spring-like element suitable for returning the slide to a starting position (rest position). The return element can be designed as a coil spring.

[0046] In this context, a limiting mechanism is understood to be a locking device suitable for limiting the movement of the slide. The limiting mechanism may include an actuating element for controlled release.

[0047] In this context, an actuating element is understood to be a control device suitable for activating a function of the instrument. The actuating element may be designed as a push button. Here, a push button is understood to be a control element suitable for triggering a function by applying pressure. The push button may be spring-loaded.

[0048] In this context, a stop element is understood to be a locking element suitable for limiting or preventing movement. The stop element can interact with a counter-stop element. In this context, a counter-stop element is understood to be a counterpart suitable for creating a locking effect with the stop element. The counter-stop element can be arranged on the second handle branch.

[0049] In this context, a first profile is understood to be a guide contour suitable for forming a positive-locking connection with a second profile. The first profile may have T-shaped cross-sections. A second profile is understood to be a complementary guide contour suitable for interacting with the first profile. The second profile may have corresponding cutouts or projections.

[0050] In this context, guide elements are understood to be structural components suitable for enabling directed movement. These guide elements can be designed as protruding areas with defined cross-sections.

[0051] In this context, a fastening pin is understood to be a connecting element suitable for coupling two components together. The fastening pin can engage in an elongated hole.

[0052] In this context, a cutting edge is understood to be a working element suitable for cutting or punching material. The cutting edge can be located at the distal end of the slide.

[0053] The invention is described and explained in more detail below with reference to some selected embodiments in conjunction with the accompanying drawings. These show: Fig. 1 a side view of a surgical instrument according to the invention with base body and handle branches; Fig. 2 Three views of the surgical instrument in the assembled state to visualize the unlocking and folding down of the slider; Fig. 3 different sectional views of the basic body with guide shaft and first handle branch; Fig. 4 different sectional views of the slide with slide guide and shaft guide; Fig. 5 different sectional views of the second handle branch with slide bearing; Fig. 6 and 7 different sectional views of the components of the actuating element; and Fig. 8 A view of a return element with spiral spring and guide pin.

[0054] The present invention relates to a surgical instrument with a releasable slide, enabling improved handling and maintenance. The surgical instrument comprises a base body with a guide shaft and a first handle arm, a sliding slide with a slide guide, a second handle arm for force transmission, a return element, and a limiting mechanism with an actuating element.

[0055] The surgical instrument features an easy-to-use release mechanism that allows the slide to be detached from the guide shaft while remaining connected to the second handle branch. This configuration offers advantages for cleaning, sterilization, and maintenance of the instrument, as the components can be partially separated. The release is achieved through the interaction of the shaft guide and the slide guide when the slide is moved proximally beyond a rest position.

[0056] The limiting mechanism normally prevents the slider from moving beyond its rest position. However, by actuating the actuator, further movement in the proximal direction can be allowed, thereby activating or triggering the unlocking mechanism.

[0057] The following figures all show the same embodiment of the surgical instrument from different angles and in varying levels of detail. Not all figures include all element labels, as these are limited to the relevant components for clarity. In particular, an embodiment of the surgical instrument is shown in which it is designed as a bone punch.

[0058] Fig. Figure 1 shows a side view of the surgical instrument 10. The surgical instrument 10 comprises a base body 12 with a guide shaft 14 and a first handle branch 16 arranged at an angle to the guide shaft. The guide shaft 14 extends distally (to the left in the illustration) from the base body 12 and includes a shaft guide 18. The distal direction refers to the direction towards the working end of the instrument, while the proximal direction refers to the opposite direction towards the user.

[0059] A slide 20 is slidably arranged on the guide shaft 14 and comprises a slide guide 22, which is designed to cooperate with the shaft guide 18 for the slidable mounting of the slide 20 on the guide shaft 14. At the distal end of the slide 20, a cutting edge 56 is arranged, which forms the cutting tool of the bone punch and is designed for cutting tissue material, in particular bone material.

[0060] A second handle arm 24 is mounted on the base body 12 and operatively connected to the slide 20 via a slide bearing 26. The slide bearing 26 is formed on the second handle arm 24 in the form of an elongated hole into which a fastening pin 27, mounted on the slide 20, engages. This arrangement allows an actuating force to be transmitted to the slide 20 in order to move the slide 20 relative to the guide shaft 14 towards a distal end position. Pressing the second handle arm 24 triggers a punching motion.

[0061] The surgical instrument 10 further comprises a limiting mechanism 30 for limiting the displacement of the slide 20 relative to the guide shaft 14 until it reaches its rest position. The limiting mechanism 30 includes an actuating element 31 with a push button 32. When actuated, the actuating element 31 allows the slide 20 to be displaced further in a proximal direction beyond its rest position.

[0062] The shaft guide 18 and the slide guide 22 work together to unlock the slide 20 when the slide 20 is pushed beyond its rest position in the proximal direction (on the right in the illustration). In this unlocked state, the slide 20 can be detached from the guide shaft 14 and remains connected to the second handle arm 24 via the slide bearing 26.

[0063] The surgical instrument 10 is operated by actuating the second handle arm 24, which transmits an actuating force to the slide 20 via the slide bearing 26. This force moves the slide 20 relative to the guide shaft 14 towards the distal end position. The return element (located in a space between the slide 20 and the guide shaft 14 in the illustrated embodiment) generates a return force that returns the slide 20 to its rest position.

[0064] Fig. Figure 2 shows three different operating states of the surgical instrument 10. In the upper illustration ( Fig. 2a) The surgical instrument 10 or the slide 20 is in the rest position. The slide 20 is held in its home position by the return element. The middle illustration ( Fig. 2b) shows the surgical instrument 10 in a state in which the slide 20 has been pushed beyond its rest position in a proximal direction by actuation of the limiting mechanism 30. In the lower illustration ( Fig. 2c) shows the surgical instrument 10 in a cleaning state in which the slide 20 is unlocked and folded away from the guide shaft 14, thus enabling complete cleaning of all components. Even in the cleaning state, the slide 20 remains connected to the second handle branch 24.

[0065] Fig. Figure 3 shows several sectional views of the base body 12 of the surgical instrument 10. The base body 12 forms the basic structure from which the guide shaft 14 extends. The guide shaft 14 includes the shaft guide 18, which is designed to guide and support the slide 20. Fig. Figure 4 shows several sectional views of the slide 20. The slide 20 includes the slide guide 22, which has a second profile 42. The second profile 42 is divided into several sections, including a first area 42a and a second area 42b. The interaction between the base body 12 and the slide 20 is described below with reference to the Fig. 3 and Fig. 4 described.

[0066] The shaft guide 18 comprises a first profile 40, which is designed to interact with the second profile 42 of the slide guide 22. The first profile 40 has a first region 40a and a second region 40b, which perform different functions in guiding and unlocking the slide 20. A first projection 44a, having a T-shaped cross-section, is arranged in the first region 40a of the first profile. The first projection 44a is designed to engage positively in a corresponding recess with a T-shaped cross-section in the second profile 42. This positive-locking connection allows the slide 20 to be held on the guide shaft 14 when the slide 20 is located between the distal end position and the rest position.

[0067] In the second section 40b of the first profile 40, the profile design is such that there is no positive-locking connection with the second profile 42. When the slide 20 is pushed beyond its rest position in a proximal direction, the profiles enter the area of ​​the second section 40b, thereby enabling the slide 20 to be released from the guide shaft 14 or to be folded down.

[0068] The first profile 40 has a projection 48 at the distal end of the guide shaft 14, which extends towards the second profile 42. The projection 48 is designed to engage in a corresponding groove of the second profile 42, thereby providing additional guidance and stabilization of the connection between the guide shaft 14 and the slide 20.

[0069] The shaft guide 18 also has a second cutout 46b and a third cutout 46c, which are designed to receive corresponding guide elements of the second profile 42. These cutouts enable the controlled sliding of the slide 20 along the guide shaft 14 and contribute to the stability of the guide connection.

[0070] The second profile 42 has three different guide elements. In the region of a distal end of the slide 20, the second profile 42 includes two first guide elements 41a projecting towards the first profile 40. The first guide elements 41a form a first cutout 46a with a T-shaped cross-section. The first cutout 46a is designed to engage positively with corresponding projections of the first profile 40.

[0071] In the region of a proximal end of the slide 20, the second profile 42 includes a second guide element 41b projecting towards the first profile 40. The second guide element 41b has a second projection 44b with a T-shaped cross-section. The second projection 44b can simultaneously form a first stop for the return element 28.

[0072] Additionally, the second profile 42, in the region of the proximal end of the slide 20, includes a third guide element 41c projecting towards the first profile 40. The third guide element 41c has a third projection 44c with a T-shaped cross-section. The third projection 44c can simultaneously form a second stop for the return element 28.

[0073] The second profile 42 further features a groove 50 into which the extension 48 of the first profile 40 engages. This arrangement enables precise guidance and positioning of the slide 20 relative to the guide shaft 14.

[0074] The various sections or areas of the second profile 42 interact with corresponding sections or areas of the first profile 40. In a first area 42a, the first profile 40 and the second profile 42 interlock positively when the slide 20 is located between the distal end position and the rest position. This positive connection holds the slide 20 to the guide shaft 14. In a second area 42b, the first profile 40 and the second profile 42 do not interlock when the slide 20 is extended proximally beyond the rest position. This configuration allows the slide 20 to be released from the guide shaft 14.

[0075] The slide 20 and the guide shaft 14 lie in contact with each other over a flat surface between a distal section of the profiles and a proximal section of the profiles. This flat contact ensures stable guidance and reduces play between the components during operation of the surgical instrument 10.

[0076] The unlocking function is based on the different interaction of the profiles in various areas. In a first area 40a, 42a, the first profile 40 and the second profile 42 interlock positively when the slide 20 is located between the distal end position and the rest position. This positive connection holds the slide 20 on the guide shaft 14.

[0077] In a second area 40b, 42b, the first profile 40 and the second profile 42 do not interlock when the slide 20 is pushed proximally beyond its rest position. The limiting mechanism 30 normally prevents the slide 20 from being pushed beyond its rest position. However, actuation of the actuating element 31 allows the slide 20 to be pushed further proximally beyond its rest position.

[0078] When the slide 20 is extended proximally beyond its rest position, the shaft guide 18 and the slide guide 22 work together to unlock the slide 20. In this state, the slide 20 can be detached from the guide shaft 14, while the slide 20 remains connected to the second handle branch 24 via the slide bearing 26. This unlocking function allows for easy disassembly and maintenance of the surgical instrument 10.

[0079] Fig. Figure 5 shows a side view of a second handle branch 24 of the surgical instrument 10. The second handle branch 24 is mounted on the base body 12 and serves to transmit an actuating force to the slide 20. By actuating the second handle branch 24, the slide 20 can be moved relative to the guide shaft 14 in the direction of a distal end position.

[0080] The second handle branch 24 includes a slide bearing 26, which is designed for operative connection with the slide 20. The slide bearing 26 can be designed in the form of an elongated hole into which a fastening pin mounted on the slide 20 engages, as shown in Fig. Figure 1 (fastening pin 27) is shown. This arrangement enables controlled force transmission from the second handle branch 24 to the slider 20.

[0081] A counter-stop element 38 is arranged on the second handle branch 24. The counter-stop element 38 interacts with a stop element 36, which is mounted on the base body 12 and connected to the push button 32, as shown in the Fig. Figures 6-7 show that the counter-stop element 38 serves to limit the movement of the second handle arm 24 and thus to control the displacement of the slide 20 in a proximal direction. By actuating the push button 32, the stop element 36 can be removed from the counter-stop element 38, thereby allowing further displacement of the slide 20 in a proximal direction beyond its rest position.

[0082] The force transmission occurs through the mechanical connection between the second handle branch 24 and the slide 20 via the slide bearing 26. When an actuating force is applied to the second handle branch 24, this force is transmitted via the slide bearing 26 to the slide 20, causing the slide 20 to move along the guide shaft 14.

[0083] The actuating element 31 of the limiting mechanism 30 has a structure that is located in the Fig. Figures 6-7 show the actuating element 31 comprising the push button 32, a return spring for resetting the push button 32, and a stop element 36, which is connected to the push button 32 and mounted on the base body 12.

[0084] As in Fig. As shown in Figure 6, the push button 32 and the stop element 36 are designed as sections of a cylindrically structured element. The cross-sectional view AA in Fig. Figure 6 illustrates the cylindrical construction of the push button 32, which has varying diameters along its length. The push button 32 has a receptacle for a coil spring 33, which serves to hold the return spring.

[0085] The stop element 36 is designed as an area with a cross-section increased compared to an adjacent area. This design enables it to interact with the counter-stop element 38 on the second handle branch 24. Fig. Figure 7 shows the stop element 36 in different views together with a screw part 35, which serves for fastening and storage on the base body 12.

[0086] The unlocking mechanism functions by allowing the stop element 36 to be removed from the counter-stop element 38 by actuating the push button 32. When the push button 32 is pressed, the stop element 36 moves axially and detaches from the counter-stop element 38. This allows the slide 20 to be moved further in a proximal direction beyond its rest position.

[0087] A return spring in a corresponding receptacle 33 ensures that the push button 32 automatically returns to its initial position after actuation. This returns the stop element 36 to the position in which it can interact with the counter-stop element 38 to ensure the normal limiting function of the limiting mechanism 30.

[0088] As in Fig.As shown in Figure 8, the return element 28 comprises a spring 52, which is designed as a coil spring. The return element 28 generates a return force on the slide 20 opposite to the actuating force. The return element 28 serves to return the slide 20 to a rest position relative to the guide shaft 14.

[0089] The spring 52 is arranged around a guide pin 54. The guide pin 54 extends coaxially through the spring 52 and provides a central axis for the spring 52. This arrangement ensures proper alignment of the spring 52 during compression and expansion. The spring 52 has a helical configuration and extends along the length of the guide pin 54. The guide pin 54 maintains the alignment of the spring 52 and prevents lateral movement during operation of the surgical instrument 10.

[0090] The return element 28 can be arranged on the slide 20, with an arrangement in the region of a proximal end of the slide 20 being possible. Alternatively, the return element 28 can be arranged in a region between the slide 20 and the guide shaft 14. In this configuration, the return element 28 projects into recesses on the slide 20 and on the guide shaft 14.

[0091] The spring 52 generates a continuous restoring force that pushes the slide 20 towards its rest position. When an actuating force is applied to the slide 20 via the second handle branch 24, the spring 52 compresses. After the actuating force is released, the spring 52 expands again and automatically returns the slide 20 to its rest position.

[0092] The invention has been comprehensively described and explained with reference to the drawings and the description. The description and explanation are to be understood as examples and not as limiting. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to a person skilled in the art when using the present invention and upon a detailed analysis of the drawings, the disclosure, and the subsequent claims.

[0093] In the claims, the words "comprise" and "with" do not preclude the presence of further elements or steps. The undefined article "a" or "an" does not preclude the presence of multiple elements. A single element or unit can perform the functions of several of the units mentioned in the claims. The mere mention of some measures in several different dependent claims is not to be understood as precluding the advantageous use of a combination of these measures. Reference numerals in the claims are not to be interpreted restrictively. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 202004017974 U1

[0006] DE 102009056099 A1

[0007] EP 3153115 A1

[0008]

Claims

[1] Surgical instrument (10) with: a base body (12) with a guide shaft (14) and a first handle branch (16) arranged at an angle to this, wherein the guide shaft (14) comprises a shaft guide (18); a slide (20) with a slide guide (22) which is designed to cooperate with the shaft guide (18) for the sliding bearing of the slide (20) on the guide shaft (14); a second handle branch (24) which is mounted on the base body (12) and is operatively connected to the slide (20) via a slide bearing (26) for transmitting an actuating force to the slide (20) in order to move the slide (20) relative to the guide shaft (14) in the direction of a distal end position; a return element (28) for generating a return force on the slide (20) opposite to the actuating force in order to return the slide (20) to a rest position relative to the guide shaft (14); and a limiting mechanism (30) for limiting a displacement of the slide (20) relative to the guide shaft (14) up to the rest position, wherein the limiting mechanism (30) comprises an actuating element (31) which, when actuated, allows a further displacement of the slide (20) in a proximal direction beyond the rest position, wherein the shaft guide (18) and the slide guide (22) cooperate to unlock the slide (20) when the slide (20) is pushed in a proximal direction beyond the rest position, so that the slide (20) can be released from the guide shaft (14) and remains connected to the second handle branch (24) via the slide bearing (26). [2] Surgical instrument (10) according to claim 1, wherein the actuating element (31) a push button (32); a return spring for resetting the push button (32); and a stop element (36) which is connected to the push button (32) and mounted on the base body (12) and which interacts with a counter-stop element (38) on the second handle branch (24), wherein the stop element (36) can be removed from the counter-stop element (38) by actuating the push button (32). [3] Surgical instrument (10) according to claim 2, wherein the push button (32) and the stop element (36) are designed as sections of a cylindrically constructed element; and the stop element (36) is designed as an area with a cross-section increased compared to an adjacent area. [4] Surgical instrument (10) according to any one of the preceding claims, wherein the shaft guide (18) comprises a first profile (40) and the slide guide (22) comprises a second profile (42), the first profile (40) and the second profile (42) interlock in a first area (40a, 42a) when the slider (20) is between the distal end position and the rest position to hold the slider (20) on the guide shaft (14); the first profile (40) and the second profile (42) in a second area (40b, 42b) when the slide (20) is pushed in a proximal direction beyond the rest position, do not interlock and allow the slide (20) to detach from the guide shaft (14). [5] Surgical instrument (10) according to claim 4, wherein the first profile (40) or the second profile (42) has in a first area a projection (44a) with a T-shaped cross-section which engages in a cutout (46a) with a T-shaped cross-section on the other profile. [6] Surgical instrument (10) according to one of claims 4 to 5, wherein the second profile (42) in the region of a distal end of the slider (20) comprises two first guide elements (41a) projecting towards the first profile (40), which form a first cutout (46a) with a T-shaped cross-section. [7] Surgical instrument (10) according to one of claims 4 to 6, wherein the second profile (42) in the region of a proximal end of the slide (20) comprises a second guide element (41b) projecting towards the first profile (40), which has a second projection (44b) with a T-shaped cross-section and preferably simultaneously forms a first stop for the return element (28). [8] Surgical instrument (10) according to one of claims 4 to 7, wherein the second profile (42) in the region of a proximal end of the slide (20) comprises a third guide element (41c) projecting towards the first profile (40), which has a third projection (44c) with a T-shaped cross-section and preferably simultaneously forms a second stop for the return element (28). [9] Surgical instrument (10) according to one of claims 4 to 8, wherein the first profile (40) has a projection (48) extending towards the second profile (42) in the region of a distal end of the shaft, which engages in a groove (50) of the second profile (42). [10] Surgical instrument (10) according to one of the preceding claims, wherein the slide (20) and guide shaft (14) lie flat against each other between a distal section of the profiles and a proximal section of the profiles. [11] Surgical instrument (10) according to one of the preceding claims, wherein the slide bearing (26) on the second handle branch (24) is formed in the form of an elongated hole into which a fastening pin (27) mounted on the slide (20) engages. [12] Surgical instrument (10) according to one of the preceding claims, wherein the return element (28) comprises a spring (52), preferably a coil spring, which is particularly preferably arranged around a guide pin (54). [13] Surgical instrument (10) according to one of the preceding claims, wherein the return element (28) is arranged on the slide (20), preferably in the region of a proximal end of the slide (20). [14] Surgical instrument (10) according to one of the preceding claims, wherein the return element (28) is arranged in an area between slide (20) and guide shaft (14) and projects into recesses on the slide (20) and on the guide shaft (14). [15] Surgical instrument (10) according to any of the preceding claims, wherein the surgical instrument (10) is designed as a bone punch; and a cutting edge (56) in the region of a distal end of the slide (20) or the guide shaft (14), wherein the cutting edge (56) is preferably arranged on the slide (20).

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