Patent Publication Number: US-2021161550-A1

Title: Transporter with locking device

Description:
BACKGROUND 
     The invention relates to a transporter of the type set out in the preamble of Claim  1 . 
     Transporters of the type in question are used in resectoscopes, particularly in urology when performing surgical work in the bladder and the urethra. They are used, for example, in conjunction with electrosurgical passage instruments for resection and vaporization of tissue, for example of tissue in the lower urinary tract. For this purpose, the resectoscopes comprise a longitudinally displaceable electrode instrument which, after the insertion of the resectoscope, can be advanced with its distal working end out of the distal end of the shaft tube of the resectoscope. 
     At its proximal end, the electrode instrument is connected to the transporter of the resectoscope, by which it can be displaced in the longitudinal direction in order to execute the cutting movement. The transporter is usually fastened removably on the proximal end of the shaft tube of the resectoscope. 
     The transporter has a longitudinally displaceable carriage, to which the electrode instrument can be coupled for joint longitudinal movement. The transporter is usually actuated by the fingers of one hand, which fingers engage on the carriage and on the stationary parts of the transporter that are rigidly connected to the guide tube. The movement of the transporter can in this case take place, for example, counter to a restoring spring, which can be designed as a leg spring or leaf spring. Examples of instruments are described in DE 10 2011 011 216 A1, US 2004/0242959 A1, U.S. Pat. No. 6,358,200 and DE 35 00 527 A1. 
     The coupling between the transporter and work instruments that can be longitudinally displaced by the latter, for example an electrode instrument, or other stationary system components, such as the shaft, is usually effected via latching connections. For example, when the proximal end of the electrode instrument is brought into contact with the corresponding connection partner in the transporter, the insertion of the electrode instrument generally effects an automatic latching of the instrument. By contrast, the unlatching of the electrode instrument usually has to be assisted manually. 
     The latching of the electrode instrument is at present effected by an undercut of an elongate latch element in a groove provided for this purpose in the instrument shaft. The latch element is for this purpose arranged transversely with respect to the longitudinal direction of the work instrument and of the resectoscope shaft in the transporter. By means of an insertion bevel on the latch element, the shaft of the inserted work instrument generates a force which displaces the latch element along its own longitudinal axis and transversely with respect to the longitudinal axis of the work instrument. By means of a counter-pressure exerted by a spring element, the latch element is then pressed back to its starting position and the undercut in the latching connection is ensured. The spring element used in the latching connection can be, for example, a compression spring or a shaped elastomer part. 
     In order to ensure a defined rest position of the latch element, even without a latched-in work instrument, and to prevent undesired dismantling, the latching connection usually comprises a built-in blocking element which is set into an aperture of the latch element and prevents the latch system from undesirably falling out of the transporter. 
     The unlatching of the work instrument or of the other latched system components is effected by the operating personnel manually displacing the latch element transversely with respect to the longitudinal axis of the transporter. 
     Since the latch element is arranged movably in a channel inside a connection body of the transporter, a narrow gap is present around the latch element, and this narrow gap can be accessed only with difficulty during cleaning and sterilization. Moreover, the displacements of the latch element can lead to smears of dirt in this gap. In addition, the channel in which the latch element is arranged inside the connection body is often closed on both sides of the transporter. On one side, the channel is closed by a side wall of the transporter, and on the other side it is closed by the spring element, for example in the form of a shaped elastomer part, or an actuation element. This additionally makes cleaning difficult and creates further cavities that are difficult to clean. It is also possible for dirt to gather in the aperture that is provided in the latch element for the blocking element. Moreover, the use of a shaped elastomer part as spring element entails the risk that, as a result of the deformation that occurs upon actuation of the latch element, dirt may become trapped in the spring element at places that are difficult to clean or that cannot be cleaned at all. 
     The object of the present invention is therefore to make available a transporter that can be more easily and more reliably cleaned, particularly in the region of the latch system provided for the latching of work instruments and other system components. 
     DESCRIPTION 
     This object is achieved by a transporter having the features of Claim  1  and by a resectoscope having the features of Claim  14 . 
     The invention relates, particularly in a first aspect, to a transporter for a resectoscope for endoscopic surgery, wherein the transporter has a connection body and, for connection to a system component in the connection body, a latch system comprising an elongate latch element, which is arranged preferably transversely with respect to the longitudinal axis of the transporter and has an engagement opening or an engagement groove, and a spring element, characterized in that one or more irrigation channels, arranged parallel to the longitudinal axis of the latch element, are formed between latch element and connection body. 
     In a preferred embodiment, the invention relates to a transporter for a resectoscope for endoscopic surgery, wherein the transporter is designed to control the longitudinal displacement of a work instrument having an elongate shaft portion and, for connection to the proximal end region of the work instrument, has a latch system comprising an elongate latch element, arranged transversely with respect to the longitudinal axis of the transporter and with a lateral engagement opening, and a spring element, characterized in that the latch element has one or more irrigation grooves arranged parallel to the longitudinal axis of the latch element. 
     In a related aspect, the invention relates to a resectoscope for use in endoscopic surgery, characterized in that it comprises a transporter according to the invention and preferably a system component latched in the transporter, particularly preferably a work instrument. 
     By the incorporation, according to the invention, of irrigation grooves into the latch element and/or into the connection body, irrigation channels are formed in the transporter which are accessible from the outside and which facilitate and improve the cleaning and sterilization of the latch system. All the elements of the latch system can be rinsed all around with irrigation liquid during cleaning and/or can be reached by sterilization gas during sterilization. The danger of continuous contamination of the instruments is thus greatly reduced compared to the prior art. 
     The latch system modified according to the invention is suitable for transporters used in endoscopic surgery. A high degree of cleanness and sterility is particularly important for these instruments. The transporters are generally parts of a resectoscope that additionally usually has a shaft part with a tubular shaft and an elongate optic insertable into the shaft part through the transporter. The parts of the resectoscope may be adapted to the requirements of the particular intervention and therefore vary. 
     In addition to the transporter, shaft part and optic, the resectoscopes can have further parts, for example an illumination means, such as an optical fibre bundle, and various work instruments (passage instruments) which are guided through the shaft of the resectoscope to the site of the intervention and which can be used there for manipulation of tissue, for example. 
     The transporter has a connection body in which the latch system according to the invention is arranged. The connection body thus directly adjoins the latch system, in particular the latch element of the latch system, but also the other components of the latch system. If the transporter is to be designed for longitudinal displacement of the latched system component, the connection body can be the carriage of the transporter, for example, or a part of the carriage. 
     The transporter is designed by means of the latch system for connection to a system component. Preferably, the connection body in particular of the transporter is designed for connection to a system component. This means that the system component can be held releasably by the latch system in the transporter, particularly in the connection body thereof. 
     The latch system is suitable for the latching of different parts. The system component can therefore be any component (part) of a resectoscope that is intended to be connected releasably to the transporter, in particular to the connection body thereof. The system component is not then part of the transporter. The system component can be chosen, for example, from the group comprising work instrument (passage instrument), optic, shaft tube system (e.g. outer tube and/or inner tube) and others. In a preferred embodiment, the system component is a work instrument. In another embodiment, the system component is an optic. 
     It will be appreciated that the transporter according to the invention can comprise not just one latch system as described herein, but also several of them, in which case the various latch systems are each designed and arranged for the latching of different system components. The transporter can comprise, for example, one, two, three or more of the latch systems described herein, preferably two or more. 
     As has been mentioned, the latchable system component is preferably a work instrument. These are generally arranged in a resectoscope in a longitudinally displaceable manner, so as allow the specialist medical team flexibility at the intervention site. The transporter can accordingly be designed to control the longitudinal displacement of a work instrument. Suitable work instruments that can be used for an intervention in endoscopic surgery are known to specialists in the field. For example, the work instrument can be an electrode instrument or a stone collection instrument, the work instrument described herein preferably being an electrode instrument. 
     The electrode instrument has an elongate shaft portion (shaft part) and is designed as a passage instrument for a resectoscope, i.e. as an instrument that is insertable into an opening of the body through a resectoscopic shaft tube. At its distal end, the electrode instrument has an electrode to which high-frequency current can be applied. The electrode can be a cutting loop, a vaporization head (PlasmaButton) or other commercially available electrode. The electrode is preferably a cutting-loop electrode. Corresponding electrodes and electrode instruments are known to specialists in the field. 
     The electrode instrument can be a bipolar electrode instrument, which comprises the electrode as part of an electrode assembly. In this case, the electrode instrument will comprise, for example, a second electrode in the distal end region of the electrode instrument, designed as neutral electrode. Alternatively, the second electrode (neutral electrode) can also be arranged on other elements of the distal end region of the resectoscope. Of course, the electrode instrument can also be designed as a monopolar instrument. 
     The system component can have an elongate shaft portion. The longitudinal axis of the system component is preferably parallel to the longitudinal axis of the resectoscope shaft or of the transporter. The proximal end region of the system component can be connected to the latch system. However, it is also conceivable to connect, i.e. latch, a lateral face of the system component to an engagement opening or engagement groove arranged laterally on or in the connection body. The latch system is preferably designed, however, for connection to the proximal end region of the system component. In this embodiment, the proximal end region of the system component is insertable into the engagement opening or engagement groove of the latch system. 
     If the system component is a work instrument, the work instrument can be longitudinally displaceable inside the shaft of the resectoscope by the transporter, i.e. is axially movable in a distal direction and a proximal direction. For attachment to the resectoscope, the work instrument has the elongate shaft portion which, in order to produce a connection that provides coupling in terms of movement, can be latched at its proximal end region on a carriage comprised by the transporter. The carriage typically slides on a tube and is held with pretensioning in a rest position via a spring unit. Thus, the work unit, e.g. the electrode, at the distal end can be moved towards and away from tissue that is to be cut, without the whole resectoscope having to be moved. In addition, by virtue of the longitudinal displaceability of the work instrument, it is possible for example to clamp tissue between a distal electrode and the insulation insert and remove it from the intervention site. 
     The proximal end region of the shaft portion of the work instrument is connected to the transporter by means of a latch system. The latch system is part of the transporter and is preferably arranged inside the carriage of the transporter. In this way, the work instrument, after it has been latched inside the carriage, can be moved together with the latter. 
     The latch system of the transporter according to the invention always comprises a latch element and a spring element and, in addition, can optionally comprise a blocking element. The latch system is arranged inside and on the transporter such that the latch element and optionally the blocking element are arranged for the most part, i.e., by about 50% or more, inside the transporter. For this purpose, the transporter has a corresponding channel-shaped hollow (channel). The latter is open at least on one side of the transporter, preferably on both sides. The hollow is more or less complementary in shape and size to the latch system. As has been described above, however, free gaps are present in the edge regions of the latch element, of the spring element and of the blocking element, which free gaps arise in the course of production and/or are necessary for ensuring a free rotatability and displaceability or other functions of the latch system. 
     The latch element is elongate and arranged transversely with respect to the longitudinal axis of the transporter. The latch element can have a shaft part and, at one end, a head part which has a greater diameter than the shaft part. This head part can serve, for example, to support the spring element. Shaft part and head part preferably have a substantially round cross section, optionally with recesses for the irrigation grooves. In other words, the latch element can have, in its shaft part, a substantially cylindrical shape, optionally with recesses for the irrigation grooves and the blocking groove. 
     The latch element has in its lateral surface, i.e. laterally in relation to its longitudinal axis, one or more lateral engagement openings and/or one or more lateral engagement grooves. One of the engagement openings or one of the engagement grooves is arranged and suitable for the insertion of one part of the system component, preferably the proximal end region of the work instrument. 
     The engagement opening can be formed like a channel and have a substantially cylindrical interior. The engagement opening can extend through the shaft part of the latch element like a channel. The engagement opening can thus generate an opening at both sides of the latch element. Alternatively, the engagement opening can be closed at the side opposite the work instrument. 
     The engagement groove can have a U-shaped cross section or a cross section in the shape of part of a circle and can extend through the shaft part of the latch element. The groove is preferably open at both ends along its longitudinal direction, i.e. allows a gas or a liquid to flow through. 
     The engagement opening and the engagement groove are arranged transversely with respect to the longitudinal axis of the latch element. 
     The latch element can have further engagement openings, for example for the engagement of a blocking element. However, according to the invention, it is preferable that a blocking element is arranged in a blocking groove in the outer wall of the latch element, as is described elsewhere herein. 
     To permit the insertion and automatic latching of the system component, preferably the work instrument, into the latch element, the engagement opening or the engagement groove can have a partially funnel-shaped inlet region, i.e. an inlet region bevelled on one side. The engagement opening or engagement groove is widened in this inlet region. During insertion, the proximal end of the work instrument can slide along a bevel surface of the inlet region and thus move the latch element to the side, i.e. transversely with respect to the longitudinal axis of the transporter, in such a way that the spring element designed as a compression spring is compressed. 
     The engagement opening or engagement groove provided for the system component, preferably the proximal end region of the work instrument, can additionally comprise one or more latch elements or grooves which enter into a latching connection with a latch element or a groove on the work instrument. In this way, a suitable undercut in the latching connection can be ensured. 
     One or more irrigation channels arranged parallel to the longitudinal axis of the latch element are formed according to the invention between latch element and connection body. The irrigation channels can be formed either by the formation of irrigation grooves in the outer wall of the latch element or by formation of irrigation grooves in the inner face of the connection body adjoining the latch element. A combination of irrigation grooves on both parts is also conceivable and is possible within the scope of the invention. Thus, in one embodiment, the latch element has one or more irrigation grooves arranged parallel to the longitudinal axis of the latch element. Alternatively or in addition, the connection body can have one or more irrigation grooves arranged parallel to the longitudinal axis of the latch element and preferably adjoining the latch element. Within the scope of the invention, it is also conceivable to form irrigation grooves in both parts, in such a way that an irrigation groove of the latch element in each case adjoins an irrigation groove of the connection body. 
     The irrigation grooves can each have a cross section in the shape of part of a circle, e.g. a hemispherical cross section, or a U-shaped cross section. The irrigation grooves are suitable for generating a liquid channel via which liquid can be flushed through gaps present between the latch element and the other parts of the transporter. For this purpose, the irrigation grooves are preferably open at both ends of the elongate latch element or of the adjoining connection body, in order to allow irrigation liquid to flow in and out. The two ends of the latch element are the ends lying along the longitudinal axis of the latch element. Inside the transporter, these ends are oriented towards the sides of the transporter (laterally). Irrigation liquid and/or gas (sterilizing gas) can accordingly be conveyed through the irrigation grooves from a lateral face of the transporter to the contralateral face of the transporter. 
     The latch element or the connection body can have one or more irrigation grooves, i.e. for example one, two, three, four or more irrigation grooves. In a preferred embodiment, the latch element or the connection body, preferably the latch element, has four irrigation grooves. The irrigation grooves can be distributed about the longitudinal axis of the latch element, on its circumference, or on the inner circumference of the hollow space of the connection body. All the irrigation grooves are preferably spaced apart equidistantly from one another. Thus, in a latch element or connection body with four irrigation grooves, the grooves can be arranged at 0°, 90°, 180° and 270° on the circumference thereof or on the inner circumference of the hollow. Pairs of irrigation grooves lying opposite each other are preferably arranged on the latch element or on the inner circumference of the hollow. 
     The latch system can moreover comprise an elongate blocking element which is arranged, transversely with respect to the longitudinal axis of the latch element, in a blocking groove in the outer wall of the latch element. In the absence of the work instrument, the blocking element prevents the latch system from falling out of the transporter. The blocking element has an elongate shaft of which one end, preferably the proximal end, is arranged at least partially in an opening of the transporter or of the carriage, which opening is not part of the latch element. In other words, this end is arranged in a body of the transporter surrounding the latch system. The other end of the blocking element, preferably the distal end, is arranged in a blocking groove of the latch element. Thus, in the absence of the work instrument, a part of the blocking element bears on a lateral face of the blocking groove and thereby prevents further movement of the latch element in the direction of the spring force exerted by the spring element. The blocking element can comprise a head part which is accessible from outside the connection body and which has a wider diameter. 
     The blocking groove is arranged laterally in the shaft part of the latch element. The blocking groove is preferably located in the end region of the latch element that does not adjoin the spring element. The blocking groove can have a cross section in the shape of part of a circle. It preferably adjoins one or more irrigation grooves and forms an irrigation channel with the irrigation groove(s). These irrigation channels formed by the irrigation grooves, and optionally by the blocking groove, extend preferably over the entire length of the latch element. 
     The blocking groove is at least in part designed with a shape and size complementary to the blocking element. However, in the longitudinal direction of the latch element, the blocking groove has a diameter greater than the width of the blocking element, in order to ensure a desired displaceability of the latch element in the longitudinal direction of the latch element. 
     The latch system moreover comprises a spring element. The spring element exerts a spring force in the direction of an outer side of the transporter, for example the outer side facing away from a blocking element. When the shaft of the work instrument is inserted into the engagement opening, a pressure is thereby exerted on the shaft in order to secure the undercut (clamping action). The spring element is preferably a compression spring, for example a helical compression spring, or an elastic shaped part. In preferred embodiments, the spring element is a helical compression spring. Since the latter does not create additional cavities in the latch system, the latch system thus obtained can be cleaned more easily and more reliably. It is particularly preferable that the spring element, in particular the helical compression spring, is made of metal. Suitable spring elements are known to specialists in the field. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Illustrative embodiments of the invention are shown schematically in the drawings, in which: 
         FIG. 1  shows a lateral, schematic sectional view of a resectoscope according to the invention, which has a transporter and an electrode instrument, the latter being longitudinally displaceable by means of the carriage of the transporter; 
         FIG. 2  shows a lateral, schematic sectional view of a transporter according to the invention, with an electrode instrument which is longitudinally displaceable by means of the carriage of the transporter; 
         FIG. 3  shows a schematic sectional view of a part of a transporter from the prior art, said transporter having a latch system with a latch element, a spring element and a blocking element, the latch element having no irrigation channels; 
         FIG. 4  shows a schematic sectional view of the part from  FIG. 3 , rotated through 90°; 
         FIG. 5  shows a schematic sectional view of the latch system of a transporter according to the invention, from the longitudinal direction of the transporter, in which the irrigation grooves of the blocking element can be seen, and 
         FIG. 6  shows a schematic sectional view of the latch system of an alternative transporter according to the invention, from the longitudinal direction of the transporter. 
     
    
    
     ILLUSTRATIVE EMBODIMENTS 
     Further advantages, characteristics and features of the present invention will become clear from the following detailed description of illustrative embodiments in which reference is made to the accompanying drawings. However, the invention is not limited to these illustrative embodiments. 
       FIG. 1  shows a lateral, schematic sectional view of a resectoscope  12  according to the invention, which has a transporter  10  and an electrode instrument  42 , the latter being longitudinally displaceable by means of the carriage  62  of the transporter  10 . The electrode instrument  42  is the system component  13  of the transporter  10  that is intended to be held releasably on the transporter  10  by means of a latch system  18 . 
     The resectoscope  12  has a shaft  46  comprising a shaft tube system  48 , which is indicated by hatching and which, in a manner not shown, consists of an outer tube and an inner tube. Extending inside the shaft tube system  48  is an optics guide tube  50  and, inside the optics guide tube  50 , an optic  54 . Extending between optics guide tube  50  and shaft tube system  48  is a work instrument  14 , which is designed as an electrode instrument  42 . In addition, an illumination means, for example in the form of an optical fibre bundle, extends in the inside of or outside the optics guide tube  50 . In addition, further elements not shown here may extend in the resectoscope  12 , for example a separate irrigation tube and the like. In its distal end region, the shaft tube system  48  comprises, in a manner not shown here, openings through which contaminated irrigation liquid can flow into the space between outer tube and inner tube and can drain off through the resectoscope shaft  46 . 
     By means of a guide element  52 , which has a cross section in the shape of part of a circle, the electrode instrument  42  is protected against displacements that deviate from the longitudinal direction of the shaft  46 , for example transversely with respect to the longitudinal direction. The guide element  52  is supported on the optic  54 . The electrode instrument  42  is mounted longitudinally displaceably on the optics guide tube  50  and has an elongate shaft  16 . 
     The proximal end of the shaft  16  of the electrode instrument  42  is latched in the interior of the carriage  62  of the transporter  10  in a manner not shown in  FIG. 1 . The carriage  62  can thus be regarded as connection body  15  in the embodiment shown. By actuation of the grip parts  56 ,  58 , the electrode instrument  42  can be moved in a constrained axial movement in the distal and proximal direction. It can be pushed beyond the distal end of the optics guide tube  50  and of the shaft tube system  48 . The operator is thus also able to manipulate tissue that is located further away from the resectoscope tip. At its distal end, the electrode instrument  42  has an electrode  44 , which is designed as a cutting loop and by means of which tissue can be removed by electrosurgical ablation. A high-frequency electrical voltage is applied to the electrode  44  in order to cut tissue. 
     The resectoscope  12  shown has a passive transporter  10  in which, by relative movement of the grip parts  56  and  58  arranged proximally from the resectoscope shaft  46 , the carriage  62  is displaced in the distal direction towards the distal, first grip part  56  counter to a spring force applied by a spring bridge  60 . In the displacement of the carriage  62  in the distal direction towards the grip part  56 , the electrode instrument  42  is forced in the distal direction by the latching (not shown in  FIG. 1 ) in the latch system  18 . Upon relaxation of the grip parts  58 ,  56 , the spring force generated by the spring bridge  60  forces the carriage  62  back to its rest position, wherein the electrode instrument  42  is pulled in the proximal direction. Upon the rearward displacement of the carriage  62 , an electrosurgical intervention can be performed with the electrode instrument  42  without manual force from the operator, i.e. passively. 
       FIG. 2  shows a lateral, schematic sectional view of the transporter  10  according to the invention shown in  FIG. 1 , with the electrode instrument  42  longitudinally displaceable by means of the carriage  62  of the transporter  10 , and with the optics guide tube  50 , but without the shaft tube system  48  of the resectoscope  12  and without the optic  54 . It will be seen that the electrode instrument  42  is inserted with the proximal end region of its shaft portion  16  into the carriage  62  of the transporter  10  and is held thereby. 
       FIGS. 3 and 4  show schematic sectional views of a part of a transporter  10  from the prior art, which comprises a latch system  18  with a latch element  20 , a spring element  24  and a blocking element  34 . The transporter  10  from the prior art differs from the transporter  10  according to the invention shown in  FIG. 5  mainly in that the latch element  20  of the transporter  10  shown in  FIGS. 3 and 4  has no irrigation channels.  FIG. 4  shows a schematic sectional view of the part from  FIG. 3  rotated through 90°. 
     The proximal end region of the shaft portion  16  of a work instrument  14  is shown which, in  FIG. 3 , is located above an engagement opening  22  and has not yet been inserted into the latter and not yet latched in place therein. The end region has a diameter smaller than the diameter of the engagement opening  22 . The engagement opening  22  is arranged in the shaft region of the latch element  20  and fully traverses the latter, i.e. is designed in the form of a channel that is open at both ends. By insertion of the shaft portion  16  into the half-funnel-shaped end region of the engagement opening  22 , the latch element  20  is displaced along its longitudinal axis in the direction of the blocking element  34  or in the direction of the funnel start (to the left in  FIG. 3 ). 
     As is described elsewhere herein, the engagement opening  22  and the end region of the shaft portion  16  of the work instrument  14  can have complementary latching lugs and latching grooves (not shown) and can thus form an additional latching connection. Moreover, by means of the spring element  24 , a latching lug of the latch system is at all times pressed onto the bottom of the latching groove, i.e. a pressure is exerted on the shaft of the work instrument  14 . In this way, the undercut within the latch system  18  is ensured. Seen from the direction of the longitudinal axis of the latch element  20 , the spring element  24  is arranged at one end of the latch element  20 . The spring element  24  is designed as an elastic shaped body and, in contrast to the latch element  20  and the blocking element  34 , is arranged partially outside the transporter  10 . The part of the spring element  24  protruding laterally from the side wall of the transporter can be used for manual actuation of the latch element  20 , in particular for releasing a latching connection present between the work instrument  14  and the latch system  18 . If a (manual) pressure is exerted on the spring element  24 , the force is transmitted to the latch element  20 , via an optional force transmission element  64 , and the latch element  20  is displaced along its longitudinal axis in the interior of the transporter  10 . In this way, the clamping and/or latching connection between engagement opening  22  and shaft portion  16  is released, such that the work instrument  14  can be easily removed from the resectoscope  12 . 
     The transporter  10  moreover has a blocking element  34  which is arranged in part in a second engagement opening  22  and in part in a channel (not shown in detail) in the connection body  15 . In this way, the latch element  20  is held in the transporter  10 , and protected from falling out, even when there is no work instrument  14  arranged in the first engagement opening  22 . The blocking element  34  is of elongate shape and is oriented transversely with respect to the longitudinal direction of the latch element  20  and parallel to the longitudinal direction of the transporter  10  and of the shaft  46 . The engagement opening  22  provided for the blocking element  34  is preferably designed as a channel substantially parallel to the engagement opening  22  provided for the work instrument  14 . Moreover, in the longitudinal direction of the latch element  20 , it is wider than the diameter of the blocking element  34 , so as not to impede the desired displacement of the latch element  20  in its longitudinal direction. The additional width, i.e. the width beyond the diameter of the blocking element, preferably corresponds to the desired stroke of the latch element  20 . 
       FIG. 5  shows a schematic sectional view of the latch system  18  of a transporter  10  according to the invention, from the longitudinal direction of the transporter  10 , in which the irrigation grooves  26  of the blocking element  34  can be seen. The transporter  10  according to the invention differs from the one shown in  FIGS. 3 and 4  at least in terms of the irrigation grooves  26  shown here. Other features, such as the arrangement of the blocking element  34  in an engagement opening  22  or the use of an elastic shaped body as spring element  24 , can also be applied in the transporter  10  of the present invention. 
     The irrigation grooves  26  of the latch element  20  extend parallel to the longitudinal axis of the latch element  20 , from one end of the latch element  20  to the other. This ensures that irrigation liquid can flow all the way through during cleaning. The irrigation grooves  26  have a U-shaped cross section. 
     At its end lying outside the connection body  15 , the latch element  20  has a head portion which has a greater diameter than the shaft portion of the latch element  20  extending into the interior of the transporter  10 . The side of the head portion directed towards the shaft portion serves as a bearing surface for a spring element  24 , which is designed as a metallic helical compression spring. The spring element  24  lies with its other end on a shoulder of the connection body  15  and exerts an outward pressure. 
     However, the latch system  18  is held in the connection body  15  of the transporter  10  by the blocking element  34 . The blocking element  34  is designed substantially like the blocking element  34  shown in  FIGS. 3 and 4 . However, it does not engage in a complementary engagement opening but instead in a blocking groove  36 , which is formed in the outer wall of the latch element  20  and of which the longitudinal axis is transverse to the longitudinal axis of the latch element  20 . The blocking groove  36  is wider than the diameter of the blocking element  34 , such that the desired displacement of the latch element  20  is not impeded. 
       FIG. 6  shows a schematic sectional view of the latch system  18  of an alternative transporter  10  according to the invention, from the longitudinal direction of the transporter  10 . In a manner not shown, the latch element  20 , like the one shown in  FIG. 5 , comprises irrigation grooves  26  which are each suitable for forming an irrigation channel  25  between the latch element  20  and the connection body  15 . 
     In contrast to the transporter  10  according to  FIG. 5 , the spring element  24  of the transporter  10  shown in  FIG. 6  is arranged on that side of the latch element  20  opposite an unlatching element  66 . The channel (hollow) provided in the connection body  15  for the latch element  20  is not open at both sides of the connection body  15  and is instead closed at one end. The spring element  24  is arranged on the closed side of this channel and is supported at one side on the end of the channel and at the other side on the latch element  20 . To support the spring element  24 , the latch element  20  has, at this end, grooves which extend about the longitudinal axis of the latch element  20  in the longitudinal direction thereof. 
     The unlatching element  66  is an actuation element (button) with which the latching connection between the work element  14  and the latch system  18  can be released. For this purpose, the unlatching element  66  is arranged on that side of the latch element  20  opposite the spring element  24 , i.e. on the side where the channel provided for the latch element  20  in the connection body  15  is open towards the outside. 
     In addition, the latch system  18  shown in  FIG. 6  also differs from the one shown in  FIG. 5  in that the proximal end region of the work element  14  is not arranged in an engagement opening  22  of the latch element  20  but in an engagement groove  23 . The engagement groove  23  is arranged in the outer wall (lateral face) of the latch element  20 . The longitudinal axis of the engagement groove  23  extends transversely with respect to the longitudinal axis of the latch element  20 . 
     The blocking element  34  has a head region which is accessible from outside the connection body  15  and which has a wider diameter than the shaft portion of the blocking element  34  arranged inside the connection body  15  and the blocking groove  36 . 
     Although the present invention has been described in detail on the basis of the illustrative embodiments, it is obvious to a person skilled in the art that the invention is not restricted to these illustrative embodiments but rather that modifications are possible, whereby individual features can be omitted or different types of combinations of features can be implemented, without departing from the scope of protection of the accompanying claims. The present disclosure covers all combinations of the individual features shown. 
     LIST OF REFERENCE SIGNS 
       
     
       
         
           
               
               
             
               
                   
               
             
            
               
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                 transporter 
               
               
                 12 
                 resectoscope 
               
               
                 13 
                 system component 
               
               
                 14 
                 work instrument 
               
               
                 15 
                 connection body 
               
               
                 16 
                 shaft portion 
               
               
                 18 
                 latch system 
               
               
                 20 
                 latch element 
               
               
                 22 
                 engagement opening 
               
               
                 23 
                 engagement groove 
               
               
                 24 
                 spring element 
               
               
                 25 
                 irrigation channel 
               
               
                 26 
                 irrigation groove 
               
               
                 28 
                 end of the latch element 
               
               
                 30 
                 lateral transporter face 
               
               
                 32 
                 contralateral transporter face 
               
               
                 34 
                 blocking element 
               
               
                 36 
                 blocking groove 
               
               
                 38 
                 outer wall 
               
               
                 40 
                 irrigation channel 
               
               
                 42 
                 electrode instrument 
               
               
                 44 
                 electrode 
               
               
                 46 
                 shaft 
               
               
                 48 
                 shaft tube system 
               
               
                 50 
                 optics guide tube 
               
               
                 52 
                 guide element 
               
               
                 54 
                 optics 
               
               
                 56 
                 grip part 
               
               
                 58 
                 grip part 
               
               
                 60 
                 spring bridge 
               
               
                 62 
                 carriage 
               
               
                 64 
                 force transmission element 
               
               
                 66 
                 unlatching element