Bendable pipe

p0001The invention relates to a bendable tube, in particular as a shank for a flexible endoscope.

p0002Fiberscopes according to the prior art exhibit at the distal end to a highly flexible, freely deflectable portion to control in a body cavity or the like, for example, selected tissue regions targeted visually and / or to treat by means of additional auxiliary instruments.

p0003Furthermore shafts with a flexible section at effective inside the body or cutting Fräsinstrumenten in minimally invasive surgery are known. despite laterally angled cutting head The latter is a high power transmission to be possible because the material to be processed, for example, bone can be hard and tough circumstances.

p0004In the endoscope shaft is known from DE-GM 69 38 905 is a flexible section of one of a plurality of axially arranged in a row, hingedly interconnected ring members. In the preparation of the articulated connections between the individual ring sections need to be mounted separately. Another, out of the<patcit id="pcit0001" dnum="DE1766209C"><text>DE-PS 17 66 209</text></patcit> known flexible endoscope shaft has loosely on four control wires strung together that is not form-locking intermeshing cylinder sections.

p0005Another of the <patcit id="pcit0002" dnum="DE1816973C"><text>DE-PS 18 16 973</text></patcit> known flexible endoscope tube arrangement consists of successively arranged pipe sections, which interlock by means of projections and recesses without a form-locking, but detachable from one another. Out<patcit id="pcit0003" dnum="EP0612496A1"><text>EP 0612496 A1</text></patcit> is a similar shaft for medical instruments known, which consists of successively arranged pipe sections which are partially joined by axes and partly by projections and recesses with each other a form-fitting. However, due to there only part shape conclusion that an additional traction placed under the pipe sections tension wires is required to hold the pipe sections together. On off<patcit id="pcit0004" dnum="EP0626604A2"><text>EP 0626604 A2</text></patcit> known flexible endoscope tube is constructed from pipe sections, the 90 ° offset from one another nose and Ausnehmungspaare have alternately connecting the pipe sections form-fit to each other. There, too, tension wires are for obtaining the bond provided, is set on the same time the control of the deflection magnitude and direction of the endoscope tube.

p0006Finally, from <patcit id="pcit0005" dnum="DE2447510A"><text>DE-OS 24 47 510</text></patcit> discloses a flexible endoscope shaft, comprising a cylindrical mesh, on the outside of a plurality of inter-engaging deflecting elements are arranged. Each deflecting element has at one end a projection and at the other end a recess.

p0007In all the above mentioned, known, flexible shafts, the disadvantage that their structure can be manufactured for a relatively expensive and, secondly, only in combination with other components for the intended use. These known flexible endoscope shafts therefore have the significant disadvantage that their production is costly and complicated because of their design. In the manufacture of these known flexible endoscope shafts also has the disadvantage that a plurality of individual components assembled and must be stored.

p0008In one of the <patcit id="pcit0006" dnum="US5152744A"><text>US-PS 51 52 744</text></patcit> known, a flexible portion having the endoscope shaft, the elastic deformability of stare at each shaft is achieved by alternately arranged in the wall recesses which are such that the individual sections of webs of a certain width are materially connected to one another. However, there is the risk that a too strong bending of the flexible portion causes a breaking of one or more connecting webs.

p0009The object of the present invention is to provide a bendable tube, in particular as a shank for a flexible endoscope, which on the one hand avoids the above-discussed disadvantages of the prior art and on the other hand allows simple and therefore economic production. Furthermore, additional funds will account for setting individual pipe sections to as completely as possible to use the remaining space within the tube for other channels, optical devices, mechanical devices and the like.

p0010The device even part of the above object is achieved by a bendable tube according to the features listed in the claim. 1 The invention accordingly provides a bendable tube, in particular as a shank for a flexible endoscope before, which is composed of pipe sections in which adjacent pipe sections are physically separated from one another by a peripheral separating gap but positively connected at least in the direction of the longitudinal axis of the tube with each other, and a pipe section having at least four or more to the adjacent pipe section facing lugs, at least one nose in the corresponding recess of the adjacent pipe section engages positively.

p0011In this case, at least one, but preferably associated with each lug a recess in the adjacent pipe portion, whereby on the one hand a good flexibility is ensured in all directions in spite of a positive connection and on the other hand the stability of the tube so formed in comparison with the prior art, is considerably improved. each recess is advantageously formed by the formed between two adjacent lugs of the same pipe section gap, so to join the bond between adjacent pipe sections lugs and recesses to one another and thus form a positive connection in all directions.

p0012The inventive bendable tube may be virtually any design can be angled depending on the arrangement and formation of the joint. The positive connection between adjacent pipe sections ensures that torsional, tensile and bending forces can be reliably absorbed, so it result in corresponding design of the parting line, as exemplified claimed in the dependent claims and described in the following description, bendable pipes for nearly any purpose. Thus it is possible with appropriate design of the interlocking elements, to allow the angle of deflection in only one or in several planes. Thus, the bending can be made possible as a rotation of the tube in itself.

p0013A built according to the principle of the invention bendable tube, however, can be used not only as a shank for a flexible endoscope, but also for numerous other applications. In the field of endoscope technology such a tube can be used for example as a trocar, which is rigid during the actual piercing through the trocar therein and after removal of the trocar is flexible. Furthermore, such a pipe can be used as reinforcement for a flexible hose outside or inside, it can serve as Kardanersatz or also be designed as a high frequency electrode. Such a tube can also be used as chain, namely a hollow chain use. A use as a stent, z. B. a stent, as esophagus or trachea support is possible. The formed by another bendable pipe sections flexible tubular member may be formed by a plurality engaged with each other standing identical pipe sections, which will be particularly favorable with regard to manufacturing technology and storage. but it can also be combined different pipe sections, not only in terms of axial length, but also in the formation of the interlocking elements.

p0014According to the invention, an articulating pipe section at least four pointing towards the adjacent tube section lugs which positively engage in corresponding recesses of the adjacent tube section. In order to form a flexible tube several such mutually articulating tube sections are required. These adjacent two tubulars tubulars have in axial direction of the pipe saw to one side at least four lugs and to the other side corresponding recesses on four.

p0015There may also be provided more than four tabs for each pipe section, which engage in a corresponding number of recesses of the adjacent tube section. Preferably also in this case the tabs are arranged such that between adjacent lugs in turn a recess is formed, in which can engage a lug of the neighboring pipe section. In this way, an intimate teeth adjacent pipe sections is achieved in a structurally simple manner. The shape of the individual lugs and corresponding recesses depends on its function. It will provide a minimum of four mushroom-shaped tabs to reliably form a circuit to the adjacent pipe section with corresponding recesses in which are these lugs ensure. The flexibility of the tube can be determined on the one hand by the shape of the nose and the other by the width of the parting line. To enable targeted angling, it is expedient to provide the mushroom-shaped nose with an at least sectionally partially circular outer contour.

p0016In order to increase the torsional strength of such a tube and, for example, allow the bending in one plane only, it is appropriate to provide in addition to the aforementioned mushroom-shaped lugs one or more rectangular tabs that correspond to the rectangular recesses and engage therein. Such guide tabs but the angular deflection need not be necessarily limited direction, if this offset seen in the longitudinal axis of the tube are arranged to each other. The offset may be achieved in a simple manner in that the recesses are arranged offset relative to the corresponding nose by a certain angle to each pipe section. However, it can also be provided groups of different tube sections which are alternately engaged with each other.

p0017According to a development of the invention, by appropriate shaping of the lugs and recesses not only a bendable or flexible tube to be created, but also changeable in its length tube when namely between mutually engaging lugs and recesses in the undercut a defined play in the axial direction is provided. Such axial length compensation, for example, be expedient if the pipe is used as a flexible shaft and an axial compensation is similar to a spline or the like required.

p0018In a further development, the mushroom-shaped lugs and correspondingly shaped recesses may be oriented oblique to the longitudinal axis of the tube, such that extends an imaginary axial extension of noses or recesses helically around the tube. If in such an embodiment, in turn, is provided in the region of the undercuts a defined play between lugs and recesses, as can be achieved by arranging traction means and / or pressure inside or outside of the tube a rotational movement by producing an axial movement. So it can be specifically controlled by controlling the axial tube length of the twist angle between the beginning and end of the tube.

p0019The above pipe sections to form the bendable tube according to the invention can be prepared, for example, as injection molded parts inexpensively in large numbers, the arrangement of tabs and recesses shall be such that an assembly by elastic bending of tabs or recesses is possible.

p0020As a rule, much more favorable but the method for producing such a tube will be angled, as can be used for example as a flexible endoscope shaft, a hollow shaft, a chain, a flexible trocar as a stent or the like. Accordingly, a rigid tube is divided by a separation process in the aforementioned pipe sections. In this case, an assembly of the pipe sections to each other is omitted. The tube can be supplied before the preparation of the joints of a surface finish, which further simplifies manufacturing. With a suitable separation process it will not be generally necessary to feed the individual tube sections of a post-processing.

p0021The production of the joints can be carried out in principle with every conceivable cutting process. Particularly in thin-walled tubes, as are some sets in the endoscope technology, separating will be preferred by a laser beam, as this gives rapid and economical production at nachbearbeitfreier parting line is possible. In the case of thick-walled pipes of larger diameter, the parting line can also be effected by firing also, by milling, and in yet larger pipes. Another separation process will be the chemical or electrochemical separation. Also in this case a post-processing of the parting line usually will be dispensed with.

p0022The invention is explained in more detail with reference to embodiments shown in the drawing. Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>a side view of two connected, produced by a separation process tube sections of a first Ausführungsforin according to the invention;</dd><dt>FIG. 2</dt><dd>a section through the in <figref idrefs="f0001">figure 1</figref> Sections shown along the section line II-II;</dd><dt>Fig. 3a</dt><dd>a second embodiment of the invention two produced a separation process portions of a flexible shaft in a first extended position;</dd><dt>FIG. 3b</dt><dd>the embodiment of <figref idrefs="f0003">Fig. 3a</figref> in a second extended position,</dd><dt>FIG. 3c</dt><dd>a variant of this second embodiment, in view to <figref idrefs="f0003">Fig. 3a</figref>.</dd><dt>Fig. 4</dt><dd>a third, produced by a separation process embodiment of two form-fit contiguous sections in longitudinal section,</dd><dt>Fig. 5</dt><dd>the two sections according <figref idrefs="f0004">figure 4</figref> in side view,</dd><dt>Fig. 6</dt><dd>sections according <figref idrefs="f0004">figure 4</figref> the angled state and sectional representation <figref idrefs="f0004">Fig. 4</figref>.</dd><dt>Fig. 7</dt><dd>a fourth, produced by a separation process embodiment of a form-fitting three contiguous sections in the longitudinal section (section line VII-VII in <figref idrefs="f0005">Fig. 9</figref>) In an extended arrangement,</dd><dt>Fig. 8</dt><dd>execution to <figref idrefs="f0005">Fig. 7</figref> according to an angled position and representation <figref idrefs="f0005">Fig. 7</figref>.</dd><dt>Fig. 9</dt><dd>execution to <figref idrefs="f0005">Fig. 7</figref> in 90 ° rotated about the longitudinal sectional view (section line IX-IX in <figref idrefs="f0005">Fig. 7</figref>) and</dd><dt>Fig. 10</dt><dd>the arrangement by <figref idrefs="f0005">Fig. 7</figref> according to an angled position and representation <figref idrefs="f0005">Fig. 9</figref>,</dd></dl>

p0023In the separation process a parting line is cut in a rigid tube in a self-contained web, which is preferably carried out by laser beam. By laser beam racing can be in a rigid tube, for example a meandering parting line, as in<figref idrefs="f0001">figure 1</figref> Groove 3 shown cut so that contiguous pipe sections 1 and 2 are formed (in <figref idrefs="f0001">figure 1</figref> are shown) only two of these pipe sections. It is advantageous that the individual pipe section is already being processed and assembled finished with the completion of the laser cutting process, without any further post-processing, and each section has a homogeneous thickness.

p0024In connection with the in <figref idrefs="f0002">figure 2</figref> cross-section shown by the two pipe sections 1 and 2 longitudinally in the <figref idrefs="f0001">figure 1</figref> shown section line II-II can be clearly seen that at the height of the section II-II visible kerf saw 3 in the circumferential direction of a pipe section four against each other by 90 ° offset tabs 11 and four also 90 ° staggered recesses 12 forms, the in substantially the same contour as the mushroom-shaped lugs have eleventh Each section 1.2 of each lug 11 is a respective recess 12 opposite in the axial direction. The recesses form circumferentially seen each undercuts the nose. This can not be separated without damage to the individual sections. The degree of flexibility is dependent on the width of the parting line 3, the length and the diameter of the single element.

p0025Of course, the number of provided to one side of tabs 11 and recesses 12 is not limited to the number 4th Through four alternating lugs and recesses to a very good flexible deflection in all levels can be achieved in the room.

p0026Also, the joints of a pipe section comprising a plurality of sections can be formed such that each are offset in axial direction adjacent noses and recesses in the circumferential direction by a certain angular amount.

p0027With the help of the <figref idrefs="f0001">figures 1</figref> and <figref idrefs="f0002">2</figref> Subdivision of a shaft tube shown to flexible endoscope shafts, flexible trocar sleeves, flexible forceps, flexible endoscopes and techno as well as flexible shafts for cardan shafts in bone and cartilage milling or the propeller shafts themselves are manufactured.

p0028When in <figref idrefs="f0003">3a</figref> illustrated embodiment, the parting line 3 'between two adjacent identical pipe sections 1', 2 'carried out so that the lying in recesses 22 lugs 21 are spaced apart by the shape of their undercuts a defined distance, so that a defined play S is ensured in the axial direction , A so executed flexible endoscope shaft can be varied in length and is for example in connection with instruments advantageous to perform using alternately inflatable and ventable annular cuffs wormlike movements to be introduced with the help of this instrument movement, for example, more easily into the intestine or other body channels to. The<figref idrefs="f0003">Figures 3a and 3b</figref> show the two portions 1 'and 2' in the two end positions in which the flexible shaft has its shortest and longest linear expansion. However, the use of such in<figref idrefs="f0003">3a</figref> shown the pipe sections 1 ', 2', if appropriate, an outer shaft, or other suitable guide means necessary to prevent adjacent portions can be disengaged, which is possible for example at a bend. This can be prevented, for example by a short thin-walled annular cylinder part either outside or inside the interlocking tube sections.

p0029When based on <figref idrefs="f0003">FIG. 3c</figref> illustrated embodiment is between the undercuts, connecting adjacent pipe sections in the longitudinal direction of the tube form-fitting manner with each other, are provided not only an axial clearance S, but also the tabs 23 and the corresponding recesses 24 skewed with respect to the longitudinal axis 5 of the pipe, such that an imaginary extension 6 of these protrusions 23 and recesses 24 helically tube bypasses. In such an arrangement then the axial clearance S is less a length compensation, similar to a spline or the like, but for producing a rotary movement. For, if the pipe sections of the in<figref idrefs="f0003">FIG. 3c</figref> The method illustrated in the final position shortest longest end position, wherein the lateral projections against which the protrusions 23 of the recesses 24, then takes place around a bend of the pipe about its longitudinal axis 5, and that between the end tube portions. This bending about the longitudinal axis 5 may be used to generate a targeted rotational movement may be provided when inside or outside of the tube corresponding pulling and / or pushing means. With such an arrangement, for example, an instrument within a shaft to be rotated without a rotational movement to the control is required. The parting line 3'c is thus opposite the parting line 3 'arranged in the region of its longitudinal extent obliquely to the axis of the fifth

p0030The <figref idrefs="f0004">Figures 4 to 6</figref> show two form-fitting interengaging identical tube sections 1 ", 2" of a third embodiment, which are cut from a rigid tube. Both tube sections 1 ", 2" have two trained in an axial direction of first tabs 31 with part-circular contour which gegeneinanderin Umfangsrichtungum are 180 ° offset. In the same axial direction, the pipe sections have second lugs 33 with a rectangular contour, which are also arranged circumferentially offset by 180 ° and each offset by 90 ° relative to the first part circular lugs 31st Moreover, both the pipe sections 1 '', 2 "between each of the first part-circular lugs 31 and the second rectangular lugs 33, recesses 34, 35 and arranged between two recesses nose 32, which also, with appropriate dimensioning of the lugs 31, 33 optionally can be dispensed with. the recess 34 undercuts the first lugs 31. In the other axial direction If both tube sections 1 ", 2" first Ausnehrnungen 36 with part-circular contour which are opposite to the first lugs 31 axially. Furthermore, both pipe sections have 1 ", 2" the rectangular second lugs 33 opposite second rectangular recesses 37 on the projections 32 as well as additional receiving recesses 38.

p0031As <figref idrefs="f0004">figure 6</figref> shows, the two sections can 1 "and 2" bend each other, said part-circular first lugs 31 of the second section 2 "form-locking in the partly circular first recesses 36 of the first portion 1" and the second lugs 33 and 40 in the rectangular recesses 37 and 41 are pivotable without their being able disengage. Thus, a flexible shaft portion provided with pipe sections 1 ', 2' in accordance with the<figref idrefs="f0004">Figures 4 to 6</figref> is provided, be used beispieisweise on a distal end portion controllable for flexible endoscopes Techno and when a bend is desired in only one plane.

p0032The reference to the <figref idrefs="f0005">Figures 7 to 10</figref> Variant shown differs from the reference to the <figref idrefs="f0004">Figures 4 to 6</figref> illustrated characterized in that the recesses of a pipe section to the corresponding lugs of the same tube section are not coaxial, but offset by 90 ° to each other, so that successive pipe sections in other planes are always angled alternately.

p0033In the <figref idrefs="f0005">Figures 7 to 10</figref> are 'denotes, in each case three tubular sections are shown, the adjacent tube sections 1' '' and 2 ''. Each pipe section has in the figures the left side, two substantially rectangular tabs 43 which are offset by 180 ° to each other. For this purpose, each offset by 90 ° are part-circular lugs 41. Between the noses 41 and 43 lugs 42 are arranged, which can be eliminated with appropriate dimensioning corresponding to the projections 32 of the third embodiment, where appropriate. Between the tabs 41 and 42 recesses 44 are formed between the lugs 42 and 43 recesses 45th

p0034For the in <figref idrefs="f0005">Figures 7 to 10</figref> right side, the pipe sections to substantially rectangular tabs 50 and disposed therebetween nose couples 49th Between two lugs 49 a partially circular recess 46 is formed between two adjacent lugs 50 a rectangular recess 47. The offset by 180 ° to each other part-circular recesses 46 serve to receive the tabs 41 of the right adjacent pipe section. This connection between the lugs 41 and the recesses 46 forms a joint function about the common center point axis of the lugs 41. Moreover, it is achieved in the direction of the longitudinal axis 5 of the pipe or pipe section by this positive-locking elements form a circuit. The rectangular tabs 43, together with the rectangular recesses 47 guides, which increase the torsional stiffness of the tube in the extended and bent state.

p0035Characterized in that the corresponding to the tabs 41 recesses 46 and the corresponding to the lugs 43 recesses are offset 47 of the same pipe section at 90 ° to each other, resulting alternating an angular deflection in a and then in an offset thereto by 90 ° plane, thereby at sufficient number of pipe sections, a flexible tube in all directions is provided, which has a high intrinsic stability and a compact structure. The in comparison to the third embodiment (<figref idrefs="f0004">FIGS. 4-6</figref>) May devoted to a level greater bending radius of the tube may be at least partially offset by a reduction of the pipe sections, as it is possible due to the staggered arrangement of recesses and lugs.

p0036Allen previously described embodiments have in common that the person responsible for the mobility of the individual pipe sections parting line is cut by a laser beam cutting process of a rigid shaft tube. Of course, the invention is not limited to the reference to the<figref idrefs="f0001 f0002 f0003 f0004 f0005">Figures 1 to 10</figref> Described embodiments limited. For example, when the separating gap is designed so that it cuts any straight pipe sections but inclined pipe sections from the rigid shaft, thereby an orientation of the flexible movability of the shaft portion or a certain curvature be preset thereof.

p0037Further, for example pipe sections may <figref idrefs="f0001">figure 1</figref> accordance with such <figref idrefs="f0003">3a</figref> or even the <figref idrefs="f0004 f0005">Figures 4 to 10</figref> be combined in a mobile shaft portion.