CLAMPING DEVICE FOR AN EXTERNAL FIXATOR

Description

[0001] The invention relates to a clamping device for connecting pins and / or rod elements of an external fixator for the treatment of bone fractures. The clamping device comprises a first clamp and a second clamp, wherein a tension element connecting the first clamp to the second clamp is provided along an axial direction in a through bore of both clamps. The tension element is mounted at one end in the second clamp and has a thread opposite the first end, which engages in a mating thread of a tightening element. The tension element is designed to tighten the first clamp and the second clamp by screwing its thread into the mating thread. The clamping device further comprises a spring element for pre-tensioning the first clamp and the second clamp.

[0002] Such clamps for use in an external fixator are known from the prior art. An external fixator serves to stabilize and fix bone fragments for the emergency, temporary treatment of a bone fracture and typically comprises a plurality of rod-shaped pins, clamping devices, and at least one rod element.

[0003] The pins, which typically have a significantly smaller diameter than the rod elements, are designed to be anchored in the bone fragments in such a way that they partially protrude through the skin of the injured person. For this purpose, the pins are, for example, designed in the form of screws that are screwed through the skin of the injured person into the bone fragments.

[0004] The ends of the pins protruding from the skin are connected to each other via clamping devices over the rod elements and fixed relative to one another. In simple bone fractures, it may be sufficient to secure only two bone fragments with pins and connect them with a single rod. In more complex bone fractures, it is sometimes necessary to connect many bone fragments. For this, numerous pins are screwed into the bone fragments and connected to each other via several rod elements, even across joints if necessary.

[0005] One advantage of stabilizing a bone fracture using an external fixator is that the bone fragments do not need to be exposed. The external fixator allows for temporary stabilization of the bone fragments, enabling the injured person to be transported. If there are other injuries, especially life-threatening ones, stabilizing the fracture with an external fixator allows for the prior treatment of these other injuries.

[0006] The use of an external fixator is particularly advantageous after natural disasters or in war zones. It allows injured individuals with stabilized bone fractures to be transported quickly from the disaster area or combat zone. Once the patient is in a condition that permits surgery, the external fixator is removed, and the bone fragments are fixed and stabilized together using internal devices such as nails, plates, or screws.

[0007] When using an external fixator, ease of use of the clamping devices is of particular importance. Especially in stressful situations and when the care of the injured person is urgent, it is desirable that the clamping devices can be operated without tools and applied and secured with just a few simple steps.

[0008] From US patent 2012 / 089,142 A1, a clamping device is known which has two clamps. Both clamps are connected by a bolt, which has a thread at each of its ends. The threads engage in nuts. When the nuts are screwed further onto the thread of the bolt, the clamps are tensioned and fixed in their position. Two springs serve to pre-tension the two clamps to transition from a wide-open position to a temporarily closed state. US patent 2018 / 132,897 A1 discloses a clamping device for connecting pins and rod elements of an external fixator. The clamping device has a first clamp and a second clamp, wherein a tension element connecting the first clamp to the second clamp is provided along an axial direction in a through bore of the first clamp (10) and the second clamp.The tensioning element is mounted at one end in the second clamp and has a thread at its opposite end. This thread engages with a mating thread of a tightening device, whereby the tensioning element is designed to clamp the first and second clamps by screwing its thread into the mating thread. Furthermore, the clamping device includes a spring for pre-tensioning the first and second clamps.

[0009] The object of the present invention is to provide an alternative clamping device which is very easy to operate and requires a significantly reduced number of components compared to the prior art.

[0010] The object of the invention is solved by a clamping device according to claim 1.

[0011] In the clamping device according to the invention, the tightening means is arranged between the spring element and the tensioning element. For the purposes of this invention, "between" refers to the axial direction. The tensioning element is supported at its first end in the second clamp. The second end, on which the thread of the tensioning element is located, is opposite the first end in the axial direction. Preferably, the first clamp and at least part of the second clamp are arranged between the first and second ends of the tensioning element. Furthermore, it is preferably provided that the tightening means is arranged directly or indirectly in contact with the first clamp. In particular, it is provided that the tightening means is arranged indirectly in contact with a first clamp, i.e., that the tightening means is operatively connected to the first clamp via a further component.When the thread of the pulling element is screwed into the mating thread of the tightening device, the first and second clamps are compressed together. This compression of the clamps creates tension, thereby holding rod elements or pins securely in the clamps.

[0012] If the clamps of the clamping device are not pre-tensioned, the spring mechanism of the clamping device creates a pre-tension. This pre-tension allows rod elements or pins to be held by the clamps without the clamps being tightly tightened. This advantageously facilitates easy operation and adjustment of the clamping device. The tensioning element, the tightening element, and the spring mechanism are arranged relative to each other such that, in the axial direction, the tightening element is positioned between the spring mechanism and the tensioning element. This results in significantly more favorable force flows when pre-tensioning and tightening the clamps, thus advantageously extending the maximum service life of the clamping device.

[0013] Preferably, the first clamp, the second clamp, the tensioning element, and the tightening device are made of a single metal. The tensioning element could be a tensile-resistant, elongated component. It could be a chain or a rope. Alternatively, the tensioning element could be a post component.

[0014] Advantageous embodiments and further developments of the invention can be found in the dependent claims and in the description with reference to the drawings.

[0015] According to a preferred embodiment of the present invention, the first clamp has a first clamping jaw and a second clamping jaw, and the second clamp has a third clamping jaw and a fourth clamping jaw, wherein the first clamping jaw, the second clamping jaw, the third clamping jaw, and the fourth clamping jaw each have a groove, wherein the grooves of the first clamping jaw and the second clamping jaw form an open first receiving groove for receiving a rod element, and wherein the grooves of the third clamping jaw and the fourth clamping jaw form an open second receiving groove for receiving a rod element, wherein the third clamping jaw and the fourth clamping jaw each have one, preferably two, further grooves, wherein the further grooves of the third clamping jaw and the fourth clamping jaw form at least one, preferably two, further open receiving grooves for receiving a pin.For this purpose, it is preferably provided that the first receiving groove is at least partially provided with first surface structures which are designed to engage in a form-fitting manner with complementary first further surface structures of a rod element and / or the second receiving groove is preferably provided at least partially with second surface structures which are designed to engage in a form-fitting manner with complementary first further surface structures of a rod element and / or the further receiving groove or the further receiving grooves are preferably provided at least partially with third surface structures which are designed to engage in a form-fitting manner with complementary second further surface structures of a pin.

[0016] This advantageously ensures that pins or rod elements can be held stably even when the clamps are not pre-tensioned. Preferably, the first, second, third, and / or fourth clamping jaws are formed in one piece. Furthermore, preferably, the first, second, third, and / or fourth clamping jaws are made of a metal, for example, aluminum, steel, or titanium. Preferably, the grooves of the first and second clamping jaws are arranged opposite each other along the axial direction. It is particularly preferred that the additional receiving grooves are arranged parallel to each other.Furthermore, it is particularly preferred that the additional receiving grooves are arranged at an angle and, in particular, perpendicular to the course of the second receiving groove.

[0017] It is conceivable that the first and second clamping jaws have interlocking structures designed to prevent rotation of the first clamping jaw relative to the second. It is also conceivable that the third and fourth clamping jaws have interlocking structures designed to prevent rotation of the third clamping jaw relative to the fourth. For this purpose, it is conceivable that the interlocking structures have pins projecting along the axial direction, which engage in recesses. This prevents the grooves from shifting relative to each other. Furthermore, it is conceivable that the first, second, and / or third surface textures have a toothed or grooved structure.

[0018] The spring element creates a preload such that, in the preloaded state of the clamping device, the diameter of the first receiving groove is smaller than the diameter of a rod element. Furthermore, the preload of the spring element causes, in the preloaded state of the clamping device, the diameter of the second receiving groove to be smaller than the diameter of a rod element, and the diameter of the subsequent receiving grooves to be smaller than the diameter of a pin. To insert a rod element or a pin into a receiving groove or a subsequent receiving groove, the rod element or pin is pressed laterally, i.e., with a direction of movement that is essentially orthogonal to the course of the respective receiving groove or subsequent receiving groove. In doing so, contrary to the preload, the diameter of the receiving groove or subsequent receiving groove is reduced.The diameter of the receiving groove is briefly increased before decreasing again when a rod element or pin is arranged in the receiving groove or further receiving groove. When a rod element is arranged in the receiving groove, the diameter of the receiving groove corresponds to the diameter of the rod element. When a pin is arranged in the further receiving groove, the diameter of the further receiving groove corresponds to the diameter of the pin. For the purposes of this invention, the diameter is the maximum distance along the axial direction between the two grooves of a receiving groove or a further receiving groove.

[0019] Because only laterally open receiving grooves or further laterally open receiving grooves for receiving rod elements or pins are present, the use of housings, in particular housings for receiving pins or for receiving rod elements, can be advantageously dispensed with. Preferably, therefore, the clamping device does not have a closed housing for receiving a rod element and / or a closed housing for receiving a pin.

[0020] Preferably, rounded insertion areas are provided on the open side of the receiving grooves to facilitate the insertion of the rod elements or pins. The rounded areas have no flat surfaces and allow for significantly easier assembly of the fixator.

[0021] According to the invention, the clamping device has a handwheel, the handwheel being engaged with the tightening element for rotating the tightening element, the tightening element being arranged in axial contact with the handwheel. This advantageously makes it possible to rotate the tightening element by means of the handwheel and thus screw the thread into the mating thread. Preferably, the handwheel is color-coded to contrast with the other elements of the clamping device. This has the advantage that, even in a stressful situation, the operator of the clamping device can immediately see where the clamping device is to be operated. Preferably, the handwheel is made of metal. It is conceivable that the handwheel has a lateral texture to facilitate operation. Preferably, the handwheel is rotatable relative to the first clamp.Furthermore, it is preferably provided that the handwheel is arranged in abutting the first clamp. In particular, it is provided that the first clamp is arranged between the second clamp and the handwheel. According to a preferred embodiment, the handwheel is arranged to partially enclose the first clamp. For this purpose, it is preferably provided that the handwheel has a projection which partially engages the first clamping jaw.

[0022] Preferably, the handwheel has a support element that is arranged against the first clamping jaw. The support element may project along the axial direction on the side of the handwheel facing the first clamping jaw. Alternatively, the support element may be arranged in a ring shape around the tightening element. The tightening element ensures that the handwheel is securely seated against the first clamping jaw and transmits the spring force of the spring element from the handwheel to the first clamping jaw for pre-tensioning.

[0023] According to the invention, the tightening means is arranged between the handwheel and the first clamp, with the mating thread of the tightening means being arranged in a first further bore of the tightening means aligned with the through bore, and an engagement part of the tightening means being positively engaged with a receptacle of the handwheel. When the handwheel is turned, the rotational movement advantageously causes the pulling element to move along the axial direction. In particular, it is provided that the handwheel and the tightening means are two separate components.

[0024] According to the invention, the handwheel has a recess, the spring element being arranged within the recess. The spring element is positioned against a support point of the handwheel and against a preloading element, the preloading element being in engagement with the tensioning element. The spring element is arranged such that a spring force of the spring element pulls the tensioning element along the axial direction towards the handwheel. This advantageously provides very efficient guidance of the preloading forces. Preferably, the spring element is arranged such that its spring force is directed along the axial direction. It is also conceivable that the recess of the handwheel is aligned with the bore. Preferably, the spring element is arranged completely within the recess.

[0025] According to a further preferred embodiment of the present invention, the pretensioning device comprises a locking screw whose secondary thread engages with a secondary thread of the tensioning element, with the spring element preferably being arranged against the underside of a screw head of the locking screw facing the support point. The pretensioning device is thus designed to transmit the spring force of the spring element to the tensioning element in such a way that the tensioning element is in a pretensioned state. For this purpose, the spring element, in conjunction with the tensioning element, ensures that the clamping jaws of the clamps between the bearing of the tensioning element in the second clamping jaw and the handwheel are pressed together so that rod elements or pins can be inserted into the corresponding receiving grooves and remain there independently and stably.Preferably, the screw head of the locking screw does not protrude beyond the handwheel in the axial direction. The locking screw also secures the clamping device against unintentional disassembly.

[0026] To transmit the spring force of the spring element to the handwheel, it is preferably provided that the support point is arranged between the handwheel's mounting and the handwheel's recess, wherein the support point is preferably formed integrally with the handwheel or wherein the support point has an annular disc which is inserted into an annular groove of the handwheel. Preferably, the locking screw extends through the support point. For this purpose, the support point has an opening through which a portion of the locking screw passes. In particular, the screw head of the locking screw is dimensioned such that it does not fit through the opening. Furthermore, it is preferably provided that the spring element is arranged around the locking screw.

[0027] According to a further preferred embodiment of the present invention, the receptacle has a profiled cross-section, preferably a corrugated and / or angular, particularly preferably a square, hexagonal, or octagonal cross-section, wherein the engagement part is arranged on an upper section of the tightening element, the upper section having a profiled cross-section, preferably a corrugated and / or angular, particularly preferably a square or hexagonal, cross-section. This advantageously ensures that the handwheel is securely engaged with the engagement part. Preferably, the tightening element has a lower section, the lower section being arranged in the bore, the lower section preferably having a round cross-section.

[0028] To provide high flexibility of the clamping device, it is preferably provided that the first clamp and the second clamp are rotatably mounted relative to each other about a rotational axis via a rotary joint and pivotally mounted relative to each other about a pivot axis arranged perpendicular to the rotational axis via a swivel joint, wherein the tension element for fixing the first clamp relative to the second clamp with respect to the rotational axis and the pivot axis is provided by screwing the thread into the mating thread. This advantageously makes it possible to simultaneously fix the clamping device with respect to both the rotational axis and the pivot axis, while also clamping the clamps.To move the clamping device from the pre-tensioned state, in which rod elements and pins can be inserted and the orientations of the clamps relative to the axis of rotation and the axis of swivel can be adjusted, to the tensioned state, in which the clamping device securely fixes the pins and rod elements in a predetermined position, only the application of tension to the tensioning element is necessary, preferably in a single step. This significantly simplifies the handling of the clamping device. The provision of an external fixator to injured persons is facilitated, especially in stressful situations, and the time required for treatment is reduced.

[0029] According to a further preferred embodiment of the present invention, the pivot joint comprises at least two pivot joint components rotatably mounted relative to each other about the axis of rotation and adjacent to each other, which can be locked in different angular positions relative to each other by means of the tension element, wherein a first further spring element is arranged between the pivot joint components, which is designed to clamp the pivot joint components away from each other in the axial direction, wherein the pivot joint components have fourth surface structures arranged opposite each other and designed to be complementary to each other, which are designed to engage positively in each other in different angular positions, wherein the first further spring element is preferably formed integrally with one of the pivot joint components.wherein the first additional spring element preferably projects axially from the pivot component. This advantageously ensures that the clamps can be rotated relative to each other with respect to the axis of rotation when pre-tensioned and are fixed relative to each other with respect to the axis of rotation when clamped. The first additional spring element also separates the pivot components of the pivot joint. Preferably, the first clamp has one of the pivot components, or the second clamp has one of the pivot components.

[0030] The tension element is preferably guided centrally through the pivot joint components forming the pivot joint. For this purpose, the pivot joint components also have the bore. The first additional spring element is preferably designed in the form of a wave spring. Preferably, the first additional spring element has rings or ring elements arranged concentrically to each other and around the axial axis, which are connected to each other by webs extending in the axial direction. It is conceivable that the first additional spring element is designed as a bending-resistant or bending-loaded and therefore flexurally elastic cylindrical beam spring. The first additional spring element is preferably integrally connected to a pivot joint component. For this purpose, it is conceivable that the first additional spring element projects axially from the pivot joint component.Preferably, the first additional spring element comprises a ring element which is integrally connected to the pivot joint component via webs. However, it is also conceivable that the first additional spring element is designed as a separate component. The pivot joint components are preferably disc-shaped and arranged opposite each other in the axial direction. Furthermore, it is conceivable that the fourth surface textures have a toothed or ribbed structure. It is also conceivable that the fourth surface textures are designed as circumferential toothed rings.

[0031] According to a further preferred embodiment of the present invention, the pivot joint comprises at least two pivot joint components which are pivotably mounted relative to each other about the pivot axis and are adjacent to each other, and which can be locked in different angular positions relative to each other by means of the tension element, wherein a second further spring means is arranged between the pivot joint components, which is designed to tension the pivot joint components away from each other in the axial direction, wherein the pivot joint components have fifth surface structures arranged opposite each other and designed to be complementary to each other, which are designed to engage positively in each other in different angular positions.

[0032] This advantageously ensures that the clamps can pivot relative to each other about the pivot axis when pre-tensioned and are fixed relative to each other about the pivot axis when clamped. The second spring element separates the pivot joint components of the pivot joint. Preferably, the first clamp has one of the pivot joint components. In particular, the second clamp has a pivot joint component. Alternatively, it is preferably the case that the second clamp has one of the pivot joint components. In particular, the first clamp has a pivot joint component.

[0033] The tension element is preferably guided centrally through the pivot joint components forming the pivot joint. For this purpose, the pivot joint components also have the bore. The second additional spring element is preferably designed as a leaf spring. In particular, it is provided that the leaf spring has a further opening arranged centrally, through which the tension element passes.

[0034] The pivot joint components are preferably disc-shaped and arranged such that one pivot joint component with a substantially cylindrical-convex side faces a substantially cylindrical-concave side of the other pivot joint component in the axial direction. Furthermore, it is conceivable that the fifth surface textures have a toothed or ribbed structure.

[0035] It is conceivable that one pivot joint component is integrally connected to a clamping jaw of a clamp, and that the other pivot joint component is integrally connected to a rotary joint component. Preferably, the other rotary joint component—that is, the rotary joint component not integrally connected to the pivot joint component—is integrally connected to a clamping jaw of the other clamp—that is, the clamp without a rotary joint component. In particular, it is provided that only the second additional spring element and an integral component comprising a pivot joint component and a rotary joint component are arranged between the first clamp and the second clamp.

[0036] According to a further preferred embodiment of the present invention, the pulling element is movably guided at its end in a ball joint of the second clamp, in particular the fourth clamping jaw, wherein the pulling element has a head end that is at least partially spherical, and the head end is movably guided in a joint socket of the pivot joint. This advantageously enables a high degree of mobility of the clamping device. The ball joint allows the pulling element to rotate about the axis of rotation and pivot about the pivot axis. In particular, this advantageously enables the pulling element to move in a 360° motion. The pulling element is not limited to a pivoting movement in a single plane. Furthermore, this advantageously ensures that only a very few components are required to implement the pivot joint.It is advantageously not necessary for an axle shaft to be arranged in an axle seat. The terms "guided" and "supported" are used synonymously within the meaning of the present invention.

[0037] To ensure that fixing and clamping the components of the clamping device is simple and requires minimal effort, the head end of the tensioning element preferably has at least one fixing groove into which a projection extending from the socket engages in such a way that rotation of the tensioning element about the axial direction is at least restricted. By restricting the rotation of the tensioning element about the axial direction, it is ensured that the tightening device can be turned onto the tensioning element using the handwheel.

[0038] Further details, features, and advantages of the invention will become apparent from the drawings and from the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the inventive concept.

[0039] They show: Fig. 1: a schematic exploded view of a clamping device according to an exemplary embodiment of the present invention; Figs. 2-7: schematic representations of a clamping device according to an exemplary embodiment of the present invention in different rotational or pivoting positions; Fig. 8a: a schematic sectional view or a schematic exploded view of a detail of a clamping device according to an exemplary embodiment of the present invention; Figs. 9a-c: schematic representations of a part of a clamping device according to an exemplary embodiment of the present invention; Figs. 10a, b: schematic representations of a tightening means of a clamping device according to an exemplary embodiment of the present invention; Fig. 11: a schematic representation of the third clamping jaw of a clamping device according to an exemplary embodiment of the present invention.12an external fixator, which has two clamping devices according to an exemplary embodiment of the present invention, Fig. 13a, on the rod element in sectional view or in perspective view for use with a clamping device according to an exemplary embodiment of the present invention.

[0040] Figure 1 Figure 1 shows a clamping device 100 according to a preferred embodiment of the present invention in a schematic exploded view. The clamping device 100 is designed to clamp pins 201 and rod elements 202 of an external fixator 200 (see Figure 1). Figure 12) to connect. An external fixator 200 is used, for example, for the temporary treatment of bone fractures. For this purpose, pins 201 are anchored in bone fragments of the fractured bone, for example, by screwing them in. At least one rod element 202 connects the pins 201 to each other and thus fixes the bone fragments relative to each other. The pins 201 and the at least one rod element 202 are connected for this purpose by clamping devices 100.

[0041] A clamping device 100 comprises a first clamp 10 and a second clamp 20. The first clamp 10 is formed by a first clamping jaw 11 and a second clamping jaw 12. The first clamping jaw 11 and the second clamping jaw 12 are preferably made in one piece from a metal, particularly preferably from aluminum, steel, or titanium. Both the first clamping jaw 11 and the second clamping jaw 12 each have a groove 13, 14, which are arranged opposite each other along the axial direction A such that the grooves 13, 14 form a first open receiving groove 16 for receiving a rod element 202. The second clamp 20 is formed by a third clamping jaw 21 and a fourth clamping jaw 22. The third clamping jaw 21 and the fourth clamping jaw 22 are also preferably made in one piece from a metal, particularly from aluminum, steel, or titanium.The third clamping jaw 21 and the fourth clamping jaw 22 have grooves 23, 24, which are arranged opposite each other along the axial direction A such that they form a second open receiving groove 28 for receiving a rod element 202. The third clamping jaw 21 and the fourth clamping jaw 22 also have further grooves 25. The further grooves 25, here two further grooves 25, are arranged at a 90° angle to the second open receiving groove 28 and lie opposite each other along the axial direction A. The further grooves 25 form further receiving grooves 29, which are designed to accommodate pins 201.

[0042] To secure the clamping jaws 11, 12, 21, 22 against rotation and to ensure that the grooves 13, 14, 23, 24 and the further grooves 25 are arranged opposite each other so that receiving grooves 16, 28 and further receiving grooves 29 are formed, respectively, interlocking structures 65 are provided on the opposing surfaces of the clamping jaws 11, 12 of the first clamp 10 and the opposing surfaces of the clamping jaws 21, 22 of the second clamp 20. In this case, the interlocking structures 65 have projections that engage in recesses (see in particular the following). Figure 11 ).

[0043] If rod elements 202 are arranged in the receiving grooves 16, 28, a first surface structuring 15 of the first clamp 10 or a second surface structuring 26 of the second clamp 20 engages in a first further surface structuring 204 of the rod elements 202 (see in particular Figure 13, which shows a cross-section of a rod element 202) and ensures a positive locking fixation of the rod elements 202 in the receiving grooves 16, 28. Preferably, the further receiving grooves 29 have third surface structures which engage in second further surface structures of the pins 201 and positively lock the pins 201 in the further receiving grooves 29.

[0044] To ensure a secure fit of the rod elements 202 or pins 201 in the clamping device 100, the clamping jaws 11, 12 of the first clamp 10 and the clamping jaws 21, 22 can be clamped against each other.

[0045] The first clamp 10 and the second clamp 20 each have a through bore 30 in which a tension element 31 is arranged along an axial direction A. The tension element 31 has an elongated, bolt-shaped body, at the first end 31' of which an at least partially spherical head end 32 is arranged. A thread 33 is arranged at a second end 31", which is opposite the first end 31'. The tension element 31 is arranged with its spherical head end 32 in a socket 34 of the second clamp 20. To prevent rotation of the tension element 31 relative to the socket 34 around the axial direction A, a protruding projection (not visible here for perspective reasons) of the socket 34 engages in a fixing groove 35 of the spherical head end 32.

[0046] In order to accommodate pins 201 and rod elements 202 in such a way that the bone fragments are fixed in an anatomically correct position relative to each other, the clamping device 100 must be designed to accommodate pins 201 and rod elements 202 with different spatial orientations, depending on the situation. This is achieved by adjusting the position of the first receiving groove 16 relative to the second receiving groove 28 and to the subsequent receiving grooves 29 (see Figures 2 to 7 ) the clamping device 100 has a swivel joint 60 which allows the first clamp 10 to be rotated about a rotation axis D relative to the second clamp 20.

[0047] The swivel joint 60 has rotatably mounted and adjacent swivel joint components 61, 62. One of the swivel joint components 62 is formed by the third clamping jaw 21. The other swivel joint component 61 is located opposite the third clamping jaw 21 in axial direction A. Both swivel joint components 61, 62 each have a fourth surface structure 64. The fourth surface structures 64 are designed here in the form of a toothed ring and are able to engage the swivel joint 60 in a positive-locking manner at different angular positions. To enable rotational movement of the swivel joint 60, a first additional spring element 63 ensures a spacing between the fourth surface structures 64. Figure 11Figure 1 shows the first additional spring element 63 in detail. The first additional spring element 63 is integrally connected to the third clamping jaw 21. It has webs 66 projecting from the third clamping jaw 21 in the axial direction A, which support a circumferential ring 67. The circumferential ring 67 separates the pivot components 61, 62 from each other, so that the fourth surface structures 64 do not engage with each other. When the pivot components 61, 62 are pushed towards each other in the axial direction A, the first additional spring element 63 bends and allows a positive locking of the fourth surface structures 64. This secures the clamping device 100 against further rotational movements about the axis of rotation D.

[0048] In the illustrated embodiment of the clamping device, a swivel joint component 62 is realized by the third clamping jaw 21.

[0049] For further adjustment of the position of the first receiving groove 16 relative to the second receiving groove 28 or the further receiving grooves 29, the clamping device 100 also has a pivot joint 70 for pivoting the first clamp 10 relative to the second clamp 20 about a pivot axis S, which is arranged perpendicular to the axis of rotation D. The pivot joint 70 is formed by pivot joint components 71, 72 and a second further spring element 73. One pivot joint component 71 has a concave-cylindrical surface, which is arranged opposite a convex-cylindrical surface of the other pivot joint component 72. The centers of the concave and convex-cylindrical shapes of the surfaces lie essentially in the center of the spherical head end 32 of the tension element 31. On the concave-cylindrical and convex-cylindrical surfaces, respectively, the clamping device 100 has a pivot joint 70.Each convex-cylindrical surface of the pivot joint components 71, 72 has a fifth surface structure 74, which is designed to interlock in different angular positions of the pivot joint 70. To enable pivoting movement of the pivot joint 70, the second additional spring element 73 ensures a spacing between the fifth surface structures 74. This second additional spring element 73 is designed as a leaf spring with a further opening 75 in the form of an elongated slot through which the tension element 31 extends. When the pivot joint components 71, 72 are pressed together against the spring force of the second additional spring element 73, the fifth surface structures 74 interlock positively and fix the first clamp 10 and the second clamp 20 relative to each other with respect to the pivot axis S.

[0050] In the illustrated embodiment of the clamping device 100, a pivot joint component 71 is realized by the second clamping jaw 12. Furthermore, the other pivot joint component 72 is integrally connected to a rotary joint component 61, which is not part of the third clamping jaw 21.

[0051] To achieve a fixation of the first clamp 10 relative to the second clamp 20 with respect to the axis of rotation D and the pivot axis S, and to achieve a tensioning of the first clamp 10 and the second clamp 20, the thread 33 of the tensioning element 31 engages in a mating thread of a tightening device 40 (see in particular Figure 8The tightening device 40 has an engagement part 43 which engages positively with a receptacle 44 of a handwheel 41 of the clamping device 100. When the handwheel 41 is turned, the tightening device 40 rotates with it, and the thread 33 of the pulling element 31 is turned into or out of the mating thread of the tightening device 40. The first clamping jaw 11, the second clamping jaw 12 with one of the pivot joint components 71, the other pivot joint component 72 with one of the rotary joint components 61, and the third clamping jaw 21 with the other rotary joint component 62 are arranged between the fourth clamping jaw 22 and the handwheel 41. When the thread 33 of the pulling element 31 is screwed into the counter thread of the tightening device 40, the pulling element 31 pulls the clamping jaws 11, 12, 21, 22, the rotary joint 60 and the swivel joint 70 together, so that the surface structures 15, 26, 64, 74 and 204 interlock in a form-fitting manner.With a single rotational movement of the handwheel 41, the rotary joint 60 and the swivel joint 70 are fixed and the clamps 10, 20 are clamped.

[0052] To ensure a positive engagement of the engagement part 43 with the handwheel 41, an upper section 43' of the engagement part 43 is arranged in a receptacle 44 of the handwheel 41. The receptacle 44 of the handwheel 41 is aligned with the bore 30. The receptacle 44 of the handwheel 41 has a profile. This profile can be wave-shaped, for example, similar to a Torx drive profile (Torx is a registered trademark) or a Stardrive drive profile (Stardrive is a registered trademark). Possible profiles include internal hexagonal, internal eight-round, or internal ten-round. However, all other polygonal shapes are also conceivable, for example, a square, hexagonal, or octagonal cross-section. This is particularly evident in the Figure 9c , which shows a view of the handwheel 41 from below. The upper section 43' of the engagement part 43 is shaped correspondingly to the profile of the receptacle 44. Figure 10 a shows a attractant 40. The profiled upper section 43' is clearly visible. Figure 10b shows a section through the upper section 43', which here has an octagonal cross-section.

[0053] The tightening element 40 projects into the bore 30 with a lower section 43". The support point 46 is preferably integrally connected to the handwheel 41. However, it is also conceivable that the support point 46 is formed by an annular disk which is inserted into an annular groove of the handwheel 41.

[0054] The clamping device 100 has a spring element 50, which is designed to pre-tension the clamping jaws 11, 12, 21, 22 of the first clamp 10 and the second clamp 20. For this purpose, the spring element 50 is arranged in a recess 45 of the handwheel 41 and bears against the support point 46 and against a pre-tensioning element 51 such that the spring force of the spring element 50 pushes the pre-tensioning element 51 away from the support point 46 along the axial direction A. The recess 45 is aligned with the receptacle 44 and has a round cross-section (see figure). Figure 9b(which shows the handwheel 41 from above). The preloading element 51 is designed as a locking screw, which engages with a further thread 53 and a further mating thread 47 of the tensioning element 31. The tightening element 40 is arranged between the tensioning element 31 and the spring element 50, so that the support point 46 is located between the tightening element 40 and the spring element 50. The spring element 50 bears against a screw head 52 of the preloading element 50. If the preloading element 51 is moved by the spring element 50 along the axial direction A, the tensioning element 31 is also pulled along the axial direction A, resulting in a preload of the clamping jaws 11, 12, 21 and 22. Reference symbol list:

[0055] 10 First clamp 11 First clamping jaw 12 Second clamping jaw 13 Groove 14 Groove 15 First surface texturing 16 First receiving groove 20 Second clamp 21 Third clamping jaw 22 Fourth clamping jaw 23 Groove 24 Groove 25 Further groove 26 Second surface texturing 28 Second receiving groove 29 Further receiving groove 30 Through hole 31 Tension element 31' First end 31" Second end 32 Head end 33 Thread 34 Joint socket 35 Fixing groove 40 Tightening device 41 Handwheel 42 First further hole 43 Engagement part 43' Upper section 43" Lower section in 44 Receptacle 45 Recess 46 Support point 50 Spring element 51 Preloading device 52 Screw head 60 Swivel joint 61 Swivel joint component 62 Swivel joint component 63 First additional spring element 64 Fourth surface texturing 70 Swivel joint 71 Swivel joint component 72 Swivel joint component 73 Second additional spring element 74 Fifth surface texturing 75 Further opening 100 Clamping device 200 External fixator 201 Pin 202 Rod element 204 First further surface structuring Aaxial direction D Rotation axis S Swivel axis

Claims

1. Clamping device (100) for connecting pins (201) and / or rod elements (202) of an external fixator (200) for the treatment of bone fractures, comprising a first clamp (10) and a second clamp (20), wherein a traction element (31) connecting the first clamp (10) to the second clamp (20) is provided along an axial direction (A) in a continuous bore (30) of the first clamp (10) and the second clamp (20), wherein the traction element (31) is mounted with a first end (31') in the second clamp (20) and has, at a second end (31") opposite the first end (31'), a thread (33) which engages into a mating thread of a tightening means (40), wherein the traction element (31) is provided for clamping the first clamp (10) and the second clamp (20) by screwing the thread (33) into the mating thread, wherein the clamping device (100) has a spring means (50) for pre-tensioning the first clamp (10) and the second clamp (20) , characterized by the tightening means (40) which is arranged between the spring means (50) and the traction element (31), wherein the clamping device (100) has a handwheel (41), wherein the handwheel (41) is in engagement with the tightening means (40) for rotating the tightening means (40), wherein the tightening means (40) is arranged abutting against the handwheel (41) along the axial direction (A) , wherein the tightening means (40) is arranged between the handwheel (41) and the first clamp (10), wherein the mating thread of the tightening means (40) is arranged in a first further bore (42) of the tightening means (40) aligned with the continuous bore (30), wherein an engagement part (43) of the tightening means (40) is in form-fitting engagement with a receptacle (44) of the handwheel (41) , wherein the handwheel (41) has a recess (45), wherein the spring means (50) is arranged within the recess (45), wherein the spring means (50) is arranged abutting against a support point (46) of the handwheel (41) and against a biasing means (51), wherein the biasing means (51) is in engagement with the traction element (31) , wherein the spring means (50) is arranged such that a spring force of the spring means (50) pulls the traction element (31) along the axial direction (A) in the direction of the handwheel (41).

2. Clamping device (100) according to claim 1, characterized by the first clamp (10) which has a first clamping jaw (11) and a second clamping jaw (12) and that the second clamp (20) has a third clamping jaw (21) and a fourth clamping jaw (22) , wherein the first clamping jaw (11), the second clamping jaw (12), the third clamping jaw (21) and the fourth clamping jaw (22) each have a groove (13, 14, 23, 24), wherein an open first receiving groove (16) for receiving a rod element (202) is formed by the grooves (13, 14) of the first clamping jaw (11) and the second clamping jaw (12) and an open second receiving groove (28) for receiving a rod element (202) is formed by the grooves (22, 24) of the third clamping jaw (21) and the fourth clamping jaw (22) , wherein the third clamping jaw (21) and the fourth clamping jaw (22) each have one, preferably two, further grooves (25), wherein at least one, preferably two, open further receiving grooves (29) for receiving a pin (201) are formed by the further grooves (25) of the third clamping jaw (21) and the fourth clamping jaw (22) , wherein the first receiving groove (16) is provided at least in sections preferably with first surface structurings (15) which are designed to engage in a form-fitting manner into complementarily formed first further surface structurings (204) of a rod element (202) and / or the second receiving groove (28) is provided at least in sections preferably with second surface structurings (26) which are designed to engage in a form-fitting manner into complementarily formed first further surface structurings (204) of a rod element (202) and / or the further receiving groove (29) or the further receiving grooves (29) is / are provided at least in sections preferably with third surface structurings which are designed to engage in a form-fitting manner into complementarily formed second further surface structurings (203) of a pin (201).

3. Clamping device (100) according to one of the preceding claims, characterized by the recess (45) which is arranged in alignment with the bore (30).

4. Clamping device (100) according to one of the preceding claims, characterized by the biasing means (51) which has a locking screw, the further thread (53) of which is in engagement with a further mating thread (47) of the traction element (31), wherein preferably the spring means (50) is arranged abutting against an underside of a screw head (52) of the locking screw facing the support point (46).

5. Clamping device (100) according to one of the preceding claims, characterized by the support point (46) which is arranged between the receptacle (44) of the handwheel (41) and the recess (45) of the handwheel (41), wherein the support point (46) is preferably formed integrally with the handwheel (41) or wherein the support point (46) comprises an annular disc which is inserted into an annular groove of the handwheel (41).

6. Clamping device (100) according to one of the preceding claims, characterized by the receptacle (44) which has a profiled cross-section, preferably a wave-shaped and / or angular, particularly preferably square, hexagonal or octagonal cross-section, wherein the engagement part (43) is arranged on an upper section (43') of the tightening means (40), wherein the upper section (43') has a profiled cross-section, preferably a wave-shaped and / or angular, particularly preferably square or hexagonal, cross-section.

7. Clamping device (100) according to claim 6, characterized by the tightening means which has a lower section (43"), wherein the lower section (43") is arranged in the bore (30), wherein the lower section (43") preferably has a round cross-section.

8. Clamping device (100) according to one of the preceding claims, characterized by the first clamp (10) and the second clamp (20) which are mounted rotatably relative to one another via a rotary joint (60) about an axis of rotation (D) and pivotably relative to one another via a swivel joint (70) about a pivot axis (S) arranged perpendicular to the axis of rotation (D), wherein the traction element (31) is provided for fixing the first clamp (10) relative to the second clamp (20) with respect to the axis of rotation (D) and the pivot axis (S) by screwing the thread (33) into the mating thread.

9. Clamping device (100) according to claim 8, characterized by the rotary joint (60) which comprises at least two rotary joint components (61, 62) mounted rotatably relative to one another about the axis of rotation (D) and adjoining one another, which can be locked relative to one another in different angular positions by means of the traction element (31), wherein a first further spring means (63) is arranged between the rotary joint components (61, 62), which is designed to bias the rotary joint components (61, 62) away from one another in the axial direction (A), wherein the rotary joint components (61, 62) have fourth surface structurings (64) arranged opposite one another and formed complementarily to one another, which are designed to engage into one another in a form-fitting manner in different angular positions , wherein the first further spring means (63) is preferably formed integrally with one of the rotary joint components (61, 62), wherein the first further spring means (63) particularly preferably protrudes from the rotary joint component (61, 62) in the axial direction (A).

10. Clamping device (100) according to one of claims 8 to 9, characterized by the swivel joint (70) which comprises at least two swivel joint components (71, 72) mounted pivotably relative to one another about the pivot axis (S) and adjoining one another, which can be locked relative to one another in different angular positions by means of the traction element (31), wherein a second further spring means (73) is arranged between the swivel joint components (71, 72), which is designed to bias the swivel joint components (71, 72) away from one another in the axial direction (A), wherein the swivel joint components (71, 72) have fifth surface structurings (74) arranged opposite one another and formed complementarily to one another, which are designed to engage into one another in a form-fitting manner in different angular positions.

11. Clamping device (100) according to one of the preceding claims, characterized by the traction element (31) which is movably guided at the end in a ball joint of the second clamp (20), in particular of the fourth clamping jaw (22), wherein the traction element (31) has a head end (32) formed spherically at least in regions, wherein the head end (32) is movably guided in a joint socket (34) of the swivel joint (70).

12. Clamping device (100) according to claim 11, characterized by the head end (32) of the traction element (31) which has at least one fixing groove (35), into which a projection protruding from the joint socket (34) engages in such a way that a rotation of the traction element (31) about the axial direction (A) is at least restricted.