EP3254808B1 - Clamping tool and bearing slide for a clamping tool - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

• unmittelbar gegen eine Spannfläche, insbesondere eines Spanntisches, gespannt werden kann, um das Werkstück zu fixieren, oder
• mittelbar, insbesondere über eine von dem Spannwerkzeug gespannte Spannkette, zum Fixieren gegen die Spannfläche gespannt werden kann.

The invention relates to a clamping tool, by means of which a workpiece

• can be clamped directly against a clamping surface, in particular a clamping table, in order to fix the workpiece, or
• can be tensioned indirectly, in particular via a tensioning chain tensioned by the tensioning tool, for fixing against the tensioning surface.

Such clamping tools must be robust and long-lasting, generate large clamping forces with small operating forces, especially those applied manually using operating tools, and be characterized by simple, yet operationally reliable operation, which also means that the clamping tool is connected to a clamping table and the workpiece or a tensioning chain and the actuation to tension the tensioning tool must apply.

STATE OF THE ART

Are known, for example EP 0 391 346 B1 Clamping tools that have a clamping rail. The tensioning rail here has a bore, via which the tensioning rail can be screwed to a clamping table with a T-slot nut and thus fixed to the clamping table. The tensioning rail has an upwardly open longitudinal recess, which corresponds approximately to an inverted T in cross section. A clamping lever can be pushed into the longitudinal recess from the end face. The tensioning lever extends out of the tensioning rail along the vertical leg of the T of the longitudinal recess. Lateral bearing pins of the tensioning lever are guided in the transverse legs of the T of the longitudinal recess. The leadership takes place in such a way that on the one hand, a displacement of the tensioning lever in the longitudinal direction of the tensioning rail is possible and, on the other hand, a pivoting of the tensioning lever about a pivot axis relative to the tensioning rail predetermined by the bearing pin is possible. The tensioning lever forms a tensioning lever part into which a tensioning screw is screwed in one end area. Another tensioning lever part of the tensioning lever forms a clamping jaw for the workpiece or a linkage of a tensioning chain. When the clamping screw is screwed into the clamping lever, the clamping screw comes to rest on a clamping surface in the area of the bottom of the longitudinal recess of the clamping rail. The further screwing in of the clamping screw leads to a pivoting of the clamping lever and thus a clamping of the workpiece in the area of the clamping jaw.

In EP 0 714 734 B1 it is proposed to separate the guarantee of the longitudinal displacement of the clamping lever relative to the clamping rail from the guarantee of the pivoting of the clamping lever. For this purpose, it is proposed that the tensioning lever is not pivotably supported directly on the tensioning rail, but rather that the tensioning lever is pivotably supported on a bearing shoe. The bearing shoe is guided in the longitudinal direction in the recess of the tensioning rail, which is also T-shaped here. In addition to the pivotable mounting of the clamping lever, the bearing shoe also serves to support the clamping screw in the area of a clamping surface of the bearing shoe for generating the clamping force.

Fig. 1 shows a bearing shoe 1 according to EP 0 714 734 B1 in a side view while Fig. 2 shows a cross section II-II of the bearing shoe 1 with the clamping lever 20 inserted therein. The bearing shoe 1 has a roughly cuboid base body 2, from which two parallel ribs 3, 4 extend upwards. In the center in the transverse direction, from a front end face of the bearing shoe 1, a longitudinal recess 5 which is continuous in the vertical direction extends into the base body 2. Lateral to the longitudinal recess 5, the base body 2 has recesses 6, 7 by means of which a receptacle 8 is formed. The recesses 6, 7 or the receptacle 8 are or is laterally limited by vertical side walls 9, 10 of the bearing shoe 1 and limited at the top by angled portions 11, 12 which form bearing surfaces 13, 14 of the bearing shoe 1. The clamping lever 20 has lateral bearing journals 15, 16 which can be inserted into the receptacle 8 from below and form the bearing surfaces 17, 18 when these are supported on the bearing surfaces 13, 14 of the bearing shoe 1 while allowing pivoting about a pivot axis 19 . In the illustrated pivot position of the tensioning lever 20 relative to the bearing shoe 1, the ribs 3, 4 (and a part of the bends 11, 12) caught between the bearing journals 15, 16 of the clamping lever 20 on the one hand and thickenings 21, 22, so that the clamping lever 20 cannot be separated from the bearing shoe 1 in this pivoted position of the clamping lever 20. The top of the ribs 3, 4 is rounded off concentrically to the pivot axis 19, so that the ribs 3, 4 do not hinder pivoting. If the clamping lever 20 is pivoted in such a way that the ribs 3, 4 of the bearing shoe 1 are arranged in a circumferential area of the clamping lever in which there are no thickenings 21, 22, the clamping lever 20 can be removed from the bearing shoe 1. It is possible that the tensioning lever 20 is acted upon away from this assembly and disassembly position via a leaf spring, namely in an opening direction of the tensioning lever 20. In the transition area from the side walls 9, 10 to the bends 11, 12, the bearing shoe 1 forms steps with horizontal support surfaces 23, 24. With these support surfaces 23, 24, the bearing shoe is supported in the vertical direction on corresponding horizontal support surfaces of the tensioning rail. For further details on this clamping tool, see the patent EP 0 714 734 B1 referenced.

The pamphlet CH 450 871 A proposes a clamping tool by means of which a clamping force is to be generated which is oriented parallel to a clamping plane. Here, the clamping tool should be designed as flat as possible so that it does not protrude beyond the machining surface of a clamped workpiece, which is arranged on the side of the workpiece facing away from the clamping plane. For one embodiment of the clamping tool, this consists of a clamping lever which, with a web-like extension with a spherical bearing surface on one side, is to be inserted directly into a T-groove of a clamping plate and to be pivotably mounted in it. For another embodiment, an anchoring element, which is also referred to here as a base, is inserted into the T-slot of the clamping plate. A longitudinal section of the anchoring element is T-shaped so that it can be inserted positively into the T-slot of the clamping plate. The horizontal leg of the T is formed with a horizontal slot. The height of the slot and thus of the horizontal leg of the T can be increased via an anchoring screw, with which the anchoring element can be clamped to the T-slot of the clamping plate and thus fixed in this (regardless of the clamping of a workpiece). In another longitudinal section, the width of the anchoring element corresponds to the width of the vertical leg of the T of the T-slot of the clamping plate. Here, the anchoring element forms a concave, part-cylindrical and obliquely upwardly and forwardly open socket, on which the end-side soon bearing surface of the web-like extension of the clamping lever downwards on the Anchoring element is supported. An exit of the clamping lever upwards on the one hand from the T-slot of the clamping plate and on the other hand from the socket of the anchoring element when generating clamping forces with the clamping tool is avoided by the fact that the socket is open at an angle upwards and at the front, so that the tensioning lever is at most at an angle can exit upwards and forwards, but this is not possible if a workpiece is clamped on a front-side clamping surface of the clamping lever. To clamp the workpiece, the anchoring element is first fixed in the T-slot of the clamping plate adjacent to the workpiece in such a way that a gap remains between the anchoring element and the workpiece, which allows the clamping lever to be inserted obliquely from the front into the T-slot of the clamping plate and into the pan enables. In such a mounted state of the clamping lever, the assembly play between the front clamping surface of the clamping lever and the workpiece can be closed by actuating a clamping screw with which the clamping lever is pivoted in the pan and the clamping surface is pressed against the workpiece. For the clamping of the workpiece, an exact positioning of the anchoring element is required, in which case the extent of the said intermediate space between the anchoring element and the workpiece must be measured exactly. Furthermore, at the beginning of the actuation of the clamping screw (and before closing the space mentioned), manual care must be taken to ensure that the clamping lever does not inadvertently emerge from the T-slot of the clamping plate and the pan.

The pamphlet U.S. 1,490,063 A discloses a tensioning lever in which two parallel cover plates are connected to one another via connecting elements. A front connecting element here swivellably carries a clamping jaw, by means of which a workpiece is to be clamped from above. A rear connecting element forms a threaded hole for a clamping screw. A central connecting element is designed as a bearing pin, via which the clamping lever can be pivotably mounted on a base part. The base part has a base with a T-shaped cross section from which a bearing plate extends vertically upwards. The bearing plate forms hook-shaped bulges. The bearing plate can enter the space between the cover plates of the tensioning lever, with which the bearing pin of the tensioning lever can be hooked into the bulges, whereby the tensioning lever is pivotably mounted on the bearing plate.

Further prior art can be found in the publications WO 2007/115640 A1 , EP 1 955 816 A2 and CH 597 976 known.

OBJECT OF THE INVENTION

• der Fertigung,
• der Bauraumerfordernisse,
• der Robustheit,
• der Kraftübertragung,
• der einsetzbaren Fertigungsmethoden und/oder Halbzeuge,
• der Lagerbedingungen und/oder
• des Kraftflusses

verbessert ist.The present invention is based on the object of proposing a clamping tool which, in particular, with regard to

• manufacturing,
• the space requirements,
• the robustness,
• the power transmission,
• the manufacturing methods and / or semi-finished products that can be used,
• the storage conditions and / or
• of the power flow

is improved.

SOLUTION

The object of the invention is achieved according to the invention with the features of the independent claim. Further preferred embodiments according to the invention can be found in the dependent claims.

DESCRIPTION OF THE INVENTION

The invention proposes a tensioning tool which has a tensioning rail, a bearing shoe which is displaceably guided in the direction of a longitudinal axis with respect to the tensioning rail, a tensioning lever which is pivotably supported via lateral bearing journals on a receptacle formed by the bearing shoe, and a tensioning screw, which is preferably is screwed into an end region of a tensioning lever part of the tensioning lever. In this respect, the clamping tool can basically according to the in EP 0 714 734 B1 described embodiments be formed.

The invention is based on the knowledge that, according to the prior art, the receptacle formed by the bearing shoe has a complex geometry, which may also be It is complex to manufacture, since the inner and outer contours of the side walls 9, 10, the angled portions 11, 12 and the ribs 3, 4 and the bearing surfaces 13, 14 and support surfaces 23, 24 (cf. Fig. 2 ) is required with the required precision. On the basis of this knowledge, the invention proposes that the receptacle formed by the bearing shoe is open laterally, so that the side walls 9, 10, and possibly also the angled portions 11, 12, can be partially or completely omitted. As a result, the use of materials can be reduced, the weight can be reduced and production can be significantly simplified. On the other hand, the prior art requires that side walls of the tensioning rail, side walls 9, 10 of the bearing shoe and the bearing journals 15, 16 must be arranged next to one another in the lateral direction. If the side walls 9, 10 are omitted, a clamping tool of compact construction can be provided, at least in the area of the bearing journals 15, 16. Alternatively or cumulatively, it is possible that, without increasing the lateral dimensions in this area, the side walls of the tensioning rail or also the bearing pins 15, 16 and / or a base body of the tensioning lever can have a greater lateral extent, which results in a more solid and stiffer configuration. Under certain circumstances, the laterally open design of the receptacle also enables a tool such as a milling cutter or drill to be moved with lateral feed for manufacturing the bearing surfaces of the receptacle with, for example, milling or drilling machining of the bearing shoe.

In a further embodiment of the invention, the bearing shoe extends in the area of the bearing journals (under certain circumstances exclusively) along the outer surface of the bearing journals, while no material of the bearing shoe is arranged between the end faces of the bearing journals and the tensioning rail. Thus, only an air gap can remain between the end faces of the bearing journals and the inner surfaces of the tensioning rail facing them, but it is also possible for the end faces of the bearing journals to rest directly on the tensioning rail for lateral support and / or guidance.

For an exclusively or partially lateral guidance of the tensioning lever, there are various possibilities within the scope of the invention, only some of these possibilities being mentioned below:
For a proposal of the invention, the tensioning lever is guided laterally in the tensioning rail by the end faces of the bearing journals resting against guide surfaces of the tensioning rail. This results in a direct lateral support of the tensioning lever on the tensioning rail.

It is possible for another proposal of the invention that the tensioning lever is laterally supported on a lateral end face of the bearing shoe, while the bearing shoe is then laterally supported and guided with a further lateral end face on the tensioning rail. Thus, for this embodiment of the tensioning tool, the bearing shoe is arranged in the force flow between the tensioning lever and the tensioning rail for the lateral support.

For a further embodiment, however, it is also possible for the bearing surfaces of the bearing journals of the tensioning lever and of the bearing shoe to have steps. The clamping lever is then guided laterally with respect to the bearing shoe via the at least one step. In this way, the lateral support of the clamping lever takes place initially via the step on the bearing shoe. The bearing shoe is then guided laterally in the tensioning rail by a lateral side surface of the bearing shoe resting against a guide surface of the tensioning rail.

In a further embodiment of the clamping tool according to the invention, bearing surfaces of the bearing shoe, in particular in the mutually facing edges of the bearing surfaces, have a bevel. If there is such a bevel, the tensioning lever does not have to have a sharp corner, edge or an abrupt change in cross-section in this area. Rather, the tensioning lever can then be designed with an undercut or an edge radius, which reduces the notch effect and results in a higher load capacity and service life of the tensioning lever.

In principle, there are various possibilities encompassed by the invention for the geometric configuration of the bearing shoe. For one proposal of the invention, the bearing shoe has a flat base body which, for example, can have parallel upper and lower sides. Here, the base body can ensure vertical support of the bearing shoe with respect to the tensioning rail in the area of the upper and lower sides, while lateral support can take place in the area of the side surfaces of the base body. Alternatively or cumulatively, the top of the base body can provide a clamping surface on which the clamping screw can be supported. In addition to the base body, the bearing shoe possibly has two bearing arms which protrude from the base body and are cranked. Form the bearing arms then the bearing surfaces that limit the receptacle for the bearing pin of the clamping lever and serve to pivot the bearing pin of the clamping lever.

In a further embodiment of the invention, the bearing arms are multifunctional in that they do not only serve to support the bearing journals of the tensioning lever. Rather, in this case, the upper sides of the bearing arms have support surfaces via which the bearing shoe is supported upwards on the tensioning rail. This can result in a stiff support of the tensioning lever on the tensioning rail, for which the force flow runs via the bearing arms between the upper-side support surfaces and the bearing surfaces. The support surfaces are preferably flat, which can result in a large contact surface between these support surfaces and the tensioning rail. It is also possible for the support surfaces to be designed parallel to a support surface formed by the underside of the base body. With a suitable distance from the support surfaces of the tensioning rail with a play or transition fit or a play to the distance between the support surfaces formed by the upper sides of the bearing arms and the support surface formed by the underside of the base body, the bearing shoe can in this way be longitudinally displaceable in the vertical direction in the Be caught in the tensioning rail.

For the out EP 0 714 734 B1 Known embodiment are the support surfaces 23, 24 of the bearing shoe, via which the bearing shoe is supported upwards on the clamping rail, laterally offset with respect to the bearing surfaces 13, 14 of the bearing shoe 1, on which the bearing journals 15, 16 are supported. This leads to bending stress on the bearing shoe 1, particularly in the area of the bends 11, 12 (cf. Fig. 2 ). According to the invention it has been recognized that, according to a preferred embodiment of the clamping tool, it is advantageous if the bearing surfaces of the bearing arms, on which the bearing journals of the tensioning lever are supported, and the support surfaces of the bearing arms, in the area in which the bearing shoe is supported upward on the tensioning rail, have a lateral overlap of at least 50%, in particular at least 70%, 80% or even 100%, which reduces or eliminates bending stress of the type explained above and thus results in reduced component stress and increases the design leeway for the dimensioning of the components .

It is possible that the bearing arms and the base body are connected to one another via stiffening ribs. This is particularly the case when the bearing shoe is manufactured using a non-cutting manufacturing process (in particular casting or forging).

While the prior art EP 0 714 734 B1 known embodiments of the bearing shoe are complex in terms of geometry and height profile, the invention proposes for a further proposal that the base body and the bearing arms have the same material height, which can result in reduced material costs and the design freedom can be expanded.

In principle, any manufacturing method can be used to manufacture the bearing shoe, in particular casting, extrusion and / or forging, etc. For a particular embodiment of the invention, the bearing shoe is made from a plate-shaped semi-finished product. This can be, for example, a spring steel sheet made of spring steel, to name but a few non-limiting examples. In this case, the production of the bearing shoe can take place in such a way that a cutout is made in the end face of the plate-shaped semi-finished product. To the side of the recess, the remaining material of the plate-shaped semi-finished product then forms the bearing arms which protrude from the base body. In a further manufacturing step, the bearing arms are then cranked as a result of plastic deformation. The process steps mentioned can be carried out in any order. It is possible that these process steps are followed by post-processing, for example with milling of the bearing surfaces with the required accuracies and surface qualities.

According to a further proposal of the invention, the bearing surfaces of the bearing arms of the bearing shoe are designed to be continuous or open in the lateral direction. In this context, a "continuous bearing surface in the lateral direction" is understood to mean, in particular, a bearing surface which merges directly or at most via a chamfer or a small curve radius into an outer side wall of the bearing shoe, and / or bearing surfaces which can be interrupted between the two bearing arms , but are not covered laterally to the outside by the material of the bearing shoe. Such a configuration enables the bearing surfaces of the bearing arms of the bearing shoe to be produced by machining. In the simplest case, the bearing surfaces can be machined using a milling cutter or drill, with the tool advancing in the lateral direction. It is also possible, however, for a milling cutter to be moved into the semi-finished product from below, in which case, however, the milling cutter can also have a diameter that is greater than the lateral extension of the bearing shoe.

While the bearing surfaces have a high surface roughness for manufacturing the bearing surfaces using a casting or forging process, machining the bearing surfaces of the bearing arms can produce an ideal bearing surface, which in particular leads to a reduction in friction and any wear . The friction, which is opposed to the pivoting of the clamping lever between the bearing surfaces of the bearing shoe on the one hand and the clamping lever on the other, significantly influences the efficiency of the clamping tool, which describes the clamping force of the clamping tool that can be brought about with a predetermined actuation force of the clamping screw.

It is entirely possible that the clamping lever is supported in terms of its pivot position on the bearing shoe only by guiding the bearing journals of the clamping lever on the bearing surfaces of the bearing shoe on the one hand and by supporting the clamping screw on the support surface of the bearing shoe on the other hand. As a result, the tensioning lever can basically be freely pivoted in the closing direction from an open position predetermined by the position of the tensioning screw. It is possible that in this case a spring is used which acts on the tensioning lever in the opening direction in order to bring about a defined starting position which is predetermined by the tensioning screw.

For a proposal of the invention, an end region of the clamping screw, in particular a support plate of the clamping screw, is coupled to the bearing shoe. The coupling takes place in such a way that the end region of the clamping screw is held or caught on the bearing shoe in both directions of adjustment of the clamping screw, which can be done without play or with play. With or without play, a swivel angle of the tensioning lever is therefore also specified, the swivel angle being dependent on the screwing angle of the tensioning screw into the tensioning lever. In addition, the coupling takes place in such a way that the end region of the clamping screw is guided with one degree of freedom in a longitudinal direction of the bearing shoe with respect to the bearing shoe. Such a degree of freedom can be used for a change in the relative position of the end region of the clamping screw with respect to the bearing shoe with a change in the screwing angle of the clamping screw into the clamping lever. For example, such a coupling between the end region of the tensioning screw and the bearing shoe can take place through a groove running in the longitudinal direction of the bearing shoe with edge-side undercuts of the groove, into which a plate of the tensioning screw can be inserted, which is then transverse to the longitudinal axis of the groove as well as after is caught in the groove at the top and bottom.

For such an embodiment, it is possible for the clamping tool to be designed without an opening spring, in which case a pivot angle or a pivot angle range is nevertheless specified in accordance with the play. Under certain circumstances, by specifying the pivot angle or the pivot angle range, it can also be avoided that the clamping lever is unintentionally pivoted into an assembly and disassembly position in which the clamping lever can be removed from the bearing shoe or unintentionally emerges from it. Rather, it may be necessary to bring about the assembly and disassembly position that the clamping screw is completely screwed out of the clamping lever (and possibly also removed from the bearing shoe).

In principle, there are many options for designing the contact and guide areas between the bearing shoe and the tensioning rail. According to a proposal of the invention, the bearing shoe is guided on both sides in guide grooves of the tensioning rail. As a first approximation, these guide grooves each have a cross section corresponding to a lying U. In the area of the respective bearing journal of the tensioning lever, the bearing shoe (when viewed in a cross section) extends exclusively above the associated bearing journal and below the upper side leg of the lying U. This has the consequence that above the upper side leg of the lying U in this cross-section only the tensioning rail and the tensioning lever are arranged, which results in a small lateral construction in this area or a wider cross-section of the tensioning lever can be used without enlarging the lateral construction.

• eine Lagerfläche mit einer Stufe zur lateralen Abstützung,
• eine Fase,
• einen Grundkörper und zwei gekröpfte Lagerarme,
• ebene Abstützflächen,
• Lagerflächen und Abstützflächen der Lagerarme mit einer lateralen Überdeckung von zumindest 50 %,
• Versteifungsrippen,
• Grundkörper und Lagerarme mit derselben Materialhöhe,
• in lateraler Richtung durchgehende Lagerflächen,
• spanend hergestellte Lagerflächen der Lagerarme insbesondere mit einem lateralen Vorschub eines Fräsers,
• eine Kopplungseinrichtung oder eine Nut mit Hinterschneidungen zum Fangen eines Endbereichs der Spannschraube u. ä.

aufweisen, wobei der Lagerschuh auch aus einem plattenförmigen Halbzeug, bspw. mit stirnseitig eingebrachte Aussparung und plastischer Verformung zur Erzeugung gekröpfter Lagerarme, hergestellt sein kann.In the context of the invention, the bearing shoe arranged in the clamping tool (as explained above), for example.

• a storage area with a step for lateral support,
• a bevel,
• a base body and two cranked bearing arms,
• flat support surfaces,
• Bearing surfaces and supporting surfaces of the bearing arms with a lateral overlap of at least 50%,
• Stiffening ribs,
• Base body and bearing arms with the same material height,
• continuous storage areas in the lateral direction,
• Machined bearing surfaces of the bearing arms, in particular with a lateral feed of a milling cutter,
• a coupling device or a groove with undercuts for catching an end region of the clamping screw and the like.

have, wherein the bearing shoe can also be made from a plate-shaped semi-finished product, for example with a recess made on the end face and plastic deformation to produce cranked bearing arms.

Advantageous further developments of the invention emerge from the patent claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the description are merely exemplary and can come into effect alternatively or cumulatively without the advantages necessarily having to be achieved by embodiments according to the invention. Without changing the subject matter of the attached claims, the following applies with regard to the disclosure content of the original application documents and the patent: Further features can be found in the drawings - in particular the illustrated geometries and the relative dimensions of several components to one another and their relative arrangement and operative connection. The combination of features of different embodiments of the invention or of features of different patent claims is also possible in a way deviating from the selected back-references of the patent claims and is hereby suggested. This also applies to features that are shown in separate drawings or mentioned in their description. These features can also be combined with features of different patent claims. Features listed in the patent claims for further embodiments of the invention can also be omitted.

The number of features mentioned in the claims and the description are to be understood in such a way that precisely this number or a greater number than the specified number is present without the need for an explicit use of the adverb "at least". For example, when an element is mentioned, it is to be understood that there is exactly one element, two elements or more elements. These characteristics can be supplemented by other characteristics or be the only characteristics that make up the product in question.

The reference signs contained in the claims do not restrict the scope of the subject matter protected by the claims. They only serve the purpose of making the claims easier to understand.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1

zeigt eine Seitenansicht eines Lagerschuhs gemäß dem Stand der Technik.

Fig. 2

zeigt einen Querschnitt II-II durch einen Lagerschuh gemäß Fig. 1 mit darin gelagertem Spannhebel.

Fig. 3 bis 11

zeigen eine erste Ausführungsform eines Spannwerkzeugs und Bauelemente desselben in unterschiedlichen Ansichten und/oder Schnitten.

Fig. 12

zeigt eine weitere Ausführungsform eines Spannwerkzeugs in einem Querschnitt.

Fig. 13 bis 16

zeigen eine weitere Ausführungsform eines Spannwerkzeugs oder von Bauelementen desselben in unterschiedlichen Ansichten und/oder Schnitten.

Fig. 17 bis 21

zeigen eine weitere Ausführungsform eines Spannwerkzeugs oder Bauelemente desselben in unterschiedlichen Ansichten und/oder Schnitten.

In the following, the invention is further explained and described with reference to preferred exemplary embodiments shown in the figures.

Fig. 1

shows a side view of a bearing shoe according to the prior art.

Fig. 2

shows a cross section II-II through a bearing shoe according to Fig. 1 with clamping lever stored in it.

Figures 3 to 11

show a first embodiment of a clamping tool and components of the same in different views and / or sections.

Fig. 12

shows a further embodiment of a clamping tool in a cross section.

Figures 13 to 16

show a further embodiment of a clamping tool or of components of the same in different views and / or sections.

Figures 17 to 21

show a further embodiment of a clamping tool or components of the same in different views and / or sections.

FIGURE DESCRIPTION

In the description of the embodiments according to the invention, the same reference numerals are used in some cases as for the embodiment according to the prior art in FIG Figs. 1 and 2 Provided that the features identified to match in terms of geometry and / or function of at least partially. The same applies to the identification of the components for different embodiments according to the invention. With regard to further details of the clamping tool that are not described in greater detail here, reference is made, for example, to the patent specification EP 0 714 734 B1 referenced, the features described there being additionally transferable to the described embodiments according to the invention without thereby departing from the scope of the invention.

Fig. 3 shows a partially sectioned side view of a tensioning tool 25. The tensioning tool 25 consists of (or has) a tensioning lever 20, a tensioning screw 26, a bearing shoe 1 and a tensioning rail 27.

The tensioning rail 27 can be via two stepped through bores (cf. EP 0 714 734 B1 ) or, as shown here, via a stepped elongated hole 28 (cf. in this regard also EP 1 955 816 A2 ) can be mounted with a clamping body such as a wall, a floor or a clamping table and fixed to it.

In a longitudinal recess 5 of the tensioning rail 27, the bearing shoe 1 is guided displaceably in the direction of a longitudinal axis 29. The bearing shoe 1 forms support surfaces 30, 31 in the region of its upper side and a support surface 32 in the region of its lower side. With the support surfaces 30, 31, the bearing shoe 1 is supported upwards on support surfaces 33, 34 of the clamping rail 27, while the support surface 32 of the bearing shoe 1 is supported downwards on a support surface 35 of the clamping rail. When the bearing shoe 1 is displaced relative to the tensioning rail 27 along the longitudinal axis 29, there is a sliding movement of the support surfaces 30 to 35. The support surfaces 30 to 35 preferably form a clearance fit or play in the vertical direction. The support surfaces 30 to 35 are oriented horizontally (when the clamping tool 25 is arranged on a horizontal base). The bearing shoe 1 has a crank 36 in the area in which a convex receptacle 8 is formed in the area of the underside of the bearing shoe 1.

The tensioning lever 20 has a front tensioning lever part 37 and a rear tensioning lever part 38. The front end region of the clamping lever part 37 forms a clamping jaw 39 which can be clamped against a workpiece or to which a clamping chain can be attached. It is also possible that a workpiece protective plate is pivotably attached to a (blind hole or) through hole 40 of the clamping jaw 39, which provides an enlarged flat (or also curved according to the workpiece) contact surface for the workpiece. In the rear end area of the rear tensioning lever part 38, the tensioning lever 20 has a continuous threaded bore 41 into which the tensioning screw 26 is screwed. An end face 42 the clamping screw 26 is supported on a clamping surface 43 of the bearing shoe 1. Here, the clamping surface 43 can be formed by a clamping plate 44 formed directly and integrally by the clamping screw 26. However, it is also possible that the clamping plate 44 is formed separately from a base body of the clamping screw 26 and is pivotably connected to the base body via a ball joint. With regard to further details on this embodiment, reference is made to the ball pressure screw, as described, for example, by the applicant under order no. 310-12-036 or 310-12-040.

The tensioning lever 20 has lateral bearing pins 15, 16 which are rigidly connected to the tensioning lever parts 37, 38 via a web 45. Here, the bearing pins 15, 16 are below the connection of the clamping lever parts 37, 38. While it is basically possible that the clamping lever 20 is T-shaped and the two transverse legs of the T are each formed by a clamping lever part 37, 38, while the vertical leg des T is formed by the web 45, the tensioning lever 20 for the illustrated embodiment in the side view is approximately formed according to an isosceles triangle with a downwardly oriented tip, the bearing pins 15, 16 being arranged in the region of the lower tip of the triangle. In order to reduce weight, the clamping lever can have lateral impressions or recesses 46. For the illustrated embodiment, the bearing journals 15, 16 have an elliptical or egg-shaped geometry. The top of the bearing journals 15, 16 and the bearing surfaces 17, 18 provided by them and the bearing surfaces 13, 14 of the receptacle 8 of the bearing shoe 1 are cylindrical segment-shaped with a diameter that is larger than the vertical extension of the bearing journals 15, 16. The center point of the cylinder segments is the pivot axis 19 for the pivoting of the clamping lever 20 relative to the bearing shoe 1. However, other geometries of the bearing journals 15, 16 and the associated bearing surfaces 13, 14 are also possible, in particular circular bearing journals 15, 16 and / or other diameters of the cylinder segments.

In the partially sectioned side view according to Fig. 3 it can be seen that the tensioning rail 27 has a bevel 47 in the area of the rear end face in the area of the longitudinal recess 5. As a result of the bevel 47, the entry opening into the longitudinal recess 5 is enlarged, so that the insertion of the bearing shoe 1 into the longitudinal recess 5 is not only possible with the exact alignment of the bearing shoe 1 to the longitudinal axis 29, but also an inclined insertion from above is possible, which Introducing is significantly simplified.

Fig. 4 shows a cross section IV-IV through the clamping tool 25 according to FIG Fig. 3 in the area of the swivel axis 19. In Fig. 4 it can be seen that the tensioning rail 27 has side walls 9, 10. The side walls 9, 10 extend vertically or slightly V-shaped outwardly inclined over the entire height of the tensioning rail 27. In the cross section shown protrude from the side walls 9, 10 parallel pairs of transverse webs 48a, 48b arranged at the same heights , 49a, 49b and 50a, 50b inwards, the letter a describing a transverse web of the side wall 9, while the letter b describes a transverse web of the side wall 10. Here, the transverse webs 48, 49 delimit the stepped elongated hole 28. The transverse webs 48a, 48b have an extension such that the distance between the end faces of the transverse webs 48a, 48b is suitable for the passage of a fastening screw. Between the transverse webs 48, 49, the side walls 9, 10 have a spacing which is suitable for receiving a sliding block in the elongated hole 28 (cf. DE 20 2007 001 985 U1 especially with regard to the possibilities of designing the geometry of the elongated hole and the sliding block to enable good guidance and power transmission). The top of the transverse web 49a, 49b can be part of the support surface 35 of the tensioning rail 27. The end faces of the transverse webs 50a, 50b are spaced apart such that (possibly with the formation of lateral play) the tensioning lever 20 with the web 45 can protrude upward out of the tensioning rail 27. The undersides of the transverse webs 50a, 50b form the support surfaces 33, 34 of the tensioning rail 27, on which the support surfaces 30, 31 of the bearing shoe 1 are supported. Immediately below the support surfaces 30, 31, 33, 34 (i.e. without lateral offset) are the bearing surfaces 13, 14, 17, 18 of the bearing shoe 1 and the bearing journals 16, 17. In the area of the bearing surfaces 13, 14, 17, 18 and of the support surfaces 30, 31, 33, 34, the bearing shoe 1 consists of cranked parallel bearing arms 51, 52 with at least a first approximation (cf. also the deviations described below with a bevel) rectangular cross-section, the upper side of the bearing arms 51, 52 forms the support surfaces 30, 31, while the underside of the bearing arms 51, 52 forms the bearing surfaces 13, 14. The clamping lever 20 is supported in the area of the pivot axis 19 by the support of the bearing pins 15, 16 via the bearing arms 51, 52 on the transverse webs 50a, 50b of the tensioning rail 27. In the vertical direction, there are between the bearing journals 15, 16 and the transverse webs 50a , 50b only interposed the bearing arms 51, 52 with the rectangular cross-sections, the lateral extent of which corresponds to the extent of the support surfaces 30, 31, 33, 34 and the bearing surfaces 13, 14, 17, 18 or a maximum of ± 30%, a maximum of ± 20% or deviates from these by a maximum of ± 10%. The distance between the lateral end faces of the bearing journals 15, 16 corresponds approximately to the sum of the lateral extent of the web 45 and the lateral extent of the bearing arms 51, 52 named sum is slightly larger than the distance between the lateral end faces of the bearing journals 15, 16, the support of lateral forces which act on the clamping lever 20 takes place via the vertical contact surfaces of the web 45 on the vertical end faces of the bearing arms 51, 52 as well as via the outer ones vertical end faces of the bearing arms 51, 52 on the side walls 9, 10 of the tensioning rail 27. If, on the other hand, the sum mentioned is slightly smaller than the distance between the end faces of the bearing journals 15, 16, lateral forces acting on the tensioning lever 20 are directly supported, Via the end faces of the bearing journals 15, 16 on the side walls 9, 10. The bearing arms 51, 52 extend in one piece (with the formation of the crank 36) from the base body 2 of the bearing shoe 1. It is optionally possible for the bearing arms 51, 52 for the purpose of stiffening are additionally connected to the base body 2 via ribs 53 (cf. Fig. 9 ).

According to the prior art, the contact surfaces between the bearing journals 15, 16 of the tensioning lever 20 with the bearing shoe 1 (here with the bearing surfaces 13, 14, 17, 18) are offset laterally inward relative to the support surfaces 23, 24 with which the bearing shoe 1 is supported on the tensioning rail 27, from which the initially explained stress of the bearing shoe with a bending stress results. In contrast, in the cross-section in Fig. 4 It can be seen that here the corresponding supports are made with a lateral overlap of at least 50%, preferably at least 60%, at least 70%, at least 80%, at least 90% or at least 95% up to 100%, thus reducing or completely eliminating the Loading of the bearing shoe 1 with a bending stress is made possible.

In Fig. 4 it can be seen that the longitudinal recess 5 of the tensioning rail 27 in the area of the bearing journals 15, 16 is delimited by the tensioning rail 27 on both sides in the form of a lying U. Here, the base leg of the lying U is formed by the side wall 9, 10, while the side legs of the lying U are formed by the underside of the transverse webs 50a, 50b and the top of the transverse webs 49a, 49b. In this bearing and connection area between the tensioning lever 20 and the tensioning rail 27, the bearing shoe 1, here with the bearing arms 51, 52, extends exclusively above the bearing journals 15, 16 and below the upper side legs of the lying U.

Fig. 5 shows the tensioning rail 27 in a central vertical longitudinal section. However, shows Fig. 6 the tensioning rail 27 in a cross section VI-VI according to Fig. 5 .

Fig. 7 shows the clamping lever 20 in a partially sectioned side view, while Fig. 8 the clamping lever 20 in a cross section VIII-VIII according to Fig. 7 shows. In Fig. 8 it can be seen that the cross section of the tensioning lever 20 in the area of the web 45 and in the area of the tensioning lever parts 37, 38 does not differ or does not differ by more than 10% or 20%.

Fig. 9 shows the bearing shoe 1 in a partially sectioned side view, while Fig. 10 the bearing shoe 1 in a section XX according to Fig. 9 shows.

Fig. 11 shows the bearing shoe 1 in a plan view. As an optional possibility, the bearing shoe 1 according to Fig. 9 have a vertical threaded bore 54 via which a tension spring can be screwed to the bearing shoe 1. Such a tension spring can serve, on the one hand, to act on the tensioning lever 20 in the opening direction and thus to act on the end face 42 of the tensioning screw 26 against the tensioning surface 43. On the other hand, such a tension spring can be elastically supported on the support surface 35 of the tensioning rail 27, whereby a frictional force which counteracts the displacement of the bearing shoe 1 in the longitudinal recess 5 of the tensioning rail 27 can be specified by dimensioning the contact force of the tensioning spring on the support surface 35. With regard to the design of such a tension spring, reference is made, for example, to the leaf spring, which the applicant provides under order no. 360-100-09 is distributed (see also EP 0 714 734 B1 regarding further design options for the tension spring).

In Fig. 10 it can be seen that it is possible that the bearing arms 51, 52 each have a bevel 55, 56 at least on the inside of the bearing surfaces 13, 14. As a result of the bevel 55, 56, the edge or the transition from the bearing journals 15, 16 to the web 45 may be rounded or an undercut, which results in a reduced notch effect, in spite of the exact fit of the clamping lever 20 in the bearing shoe 1 .

According to Fig. 11 The bearing arms 51, 52 extend “fork-like” and parallel to one another from the base body 2 of the bearing shoe 1.

Fig. 12 shows a cross section accordingly Fig. 4 by a clamping tool 25 for another embodiment. Have here (otherwise Figures 3 to 11 corresponding configuration of the clamping tool 25) the bearing surfaces 13, 14 of the bearing journals 15, 16 of the tensioning lever 20 on the one hand and the bearing surfaces 17, 18 of the bearing shoe 1 in the cross section shown Correspondingly designed steps 57, 58, so that in this case also the bearing surfaces 13, 14, 17, 18 are able to transmit a lateral support force between the clamping lever 20 and the bearing shoe 1, which in turn is then through the vertical side surfaces of the bearing arms 51, 52 of the bearing shoe 1 can be supported on the side walls 9, 10 of the tensioning rail 27.

The components of the clamping tool 25 can be cast and forged, and the components can be reworked by milling, for example, in particular to produce the bearing surfaces 13, 14, the steps 57, 58 and the like.

Figures 13 to 16 show a further embodiment of a clamping tool 25 or of components of the same, the statements made about the previous embodiments apply here until further notice. While for this embodiment the tensioning rail 27 is unchanged compared to the previous embodiment, the tensioning lever 20 has a modified geometry with modified tensioning lever parts 37, 38 as well as a modified design of the web 45 and a modified vertical distance of the bearing pins 15, 16 from the tensioning lever parts 37, 38 in the vertical direction.

A changed design of the bearing shoe is particularly in the Figures 14 to 16 It can be seen: The bearing shoe 1 is here preferably made from a plate-shaped semi-finished product, for example a spring steel sheet. To form the bearing arms, a U-shaped end-face incision, a cutout or a recess 59 is made in the semi-finished product. The bearing arms 51, 52 are then plastically deformed to produce the offset 36. It goes without saying that the plastic deformation of the semifinished product can also take place first and then the cutout 59 can be produced. In a further milling or drilling operation, the bearing surfaces 13, 14 and any bevel 55, 56 can then be produced, whereby it is possible here for the milling cutter to be advanced from the bottom to the top (which is important for the formation of the bearing surfaces 13, 14 and / or the bevels 55, 56 applies) or a lateral advance is possible (which applies in particular to the production of the bearing surfaces 13, 14). In a final work step, the flattened, flat support surfaces 30, 31 can then be produced, in particular by means of milling. For the exemplary embodiment shown, the bearing shoe 1 has an essentially constant material height (approximately corresponding to the thickness of the plate-shaped semi-finished product), it being possible for the material height to be slightly reduced in the area of the flattened areas to form the support surfaces 30, 31.

In the Figures 17 to 21 a further embodiment of a clamping tool 25 or of components of the same is shown. For the previous exemplary embodiments, the clamping screw 26 was only coupled to the bearing shoe on one side due to the one-sided contact with the clamping surface 43 of the bearing shoe 1, which makes it possible to limit the opening movement of the clamping lever 20 and to generate the clamping force when the clamping screw 26 is screwed in. For the embodiment according to Figures 17 to 21 the bearing shoe 1 has a central groove 60 which is oriented in the direction of the longitudinal axis and which has lateral undercuts 61, 62. A clamping plate 44, which here is formed integrally and in one piece from the clamping screw 26 (although it is also entirely possible that the clamping plate is formed separately and is connected to a base body of the clamping screw 26 via a ball joint), is in the groove 60 behind the undercuts 61, 62 caught. This can be done with a play in the vertical direction or with a play fit or a transition fit.

The cross section of the groove 60 is shown in FIG Fig. 19 to recognize. In the area of the groove 60, the bearing shoe 1 is U-shaped in cross-section with a horizontal base leg 63 and vertical side legs 64, 65. The top of the base leg 63 serves to form the clamping surface 43 and thus to support the clamping force of the clamping screw 26. The Side legs 64 have rib-like transverse webs 66, 67, below which the undercuts 61, 62 are formed and on the lower support surfaces 68, 69 of which the clamping plate 44 is supported upwards. For the exemplary embodiment shown, the support surfaces 68, 69 are inclined in such a way that they run upwards (without this necessarily being the case). The lateral guidance of the clamping screw 26 takes place, as shown, through the end faces of the transverse webs 66, 67, it also being entirely possible for the lateral guidance to take place through the side legs 64, 65, on which the clamping plate 44 then comes to rest.

As in the top view according to Fig. 21 As can be seen, the groove is designed to be open on one side, namely in the direction away from the receptacle 8. The closed end of the groove 60 is arranged adjacent to the crank 36. The transverse webs 66, 67 run out at the closed end of the groove 60, so that an insertion opening 70 in the form of a segment of a circle results, with which the groove 60 is opened in this end region. Here, the edge of the insertion opening 70 extends over a circumferential angle of more than 180 °, in particular in the range from 200 ° to 270 °. The diameter of the insertion opening 70 is slightly larger than the diameter of the clamping plate 44, so that the clamping screw 26 with the clamping plate 44 from above into the insertion opening 70 and can be inserted into the groove 60. If the clamping screw 26 is then moved away from the receptacle 8 and the bearing arms 51, 52 along the longitudinal recess 5, the clamping screw 26 with the clamping plate 44 is caught between a bottom 71 of the groove 60 and the support surfaces 68, 69 of the transverse webs 66, 67.

The tensioning lever 20 is preferably assembled with the bearing shoe 1 as follows: First, the tensioning screw 26 is screwed into the tensioning lever 20. The clamping plate 44 of the clamping screw 26 is then inserted through the insertion opening 70 into the groove 60. If the clamping plate 44 of the clamping screw 26 is still in the end region of the groove 60 formed by the insertion opening 70, the bearing pins 15, 16 of the clamping lever 20 are arranged in the longitudinal direction in front of the receptacle 8. With a movement of the clamping lever 20 in the direction of the longitudinal axis 29, the clamping plate 44 of the clamping screw 26 moves to the rear in the groove 60, whereby the clamping plate 44 is then caught in the groove 60. At the same time, if necessary with a slight pivoting of the clamping lever, in Fig. 17 counterclockwise, the clamping lever 20 with the bearing pin 15, 16 into the receptacle 8. The assembly unit formed in this way with the tensioning lever 20, the tensioning screw 26 and the bearing shoe 1 can then be inserted into the tensioning rail 27.

Any materials with any manufacturing processes, alloys, or surface treatments can be used for the components of the clamping tool 25. A component can be cast, forged or extruded, or a plate-shaped semi-finished product can be used. It is possible that a surface of the component is surface-finished, in particular galvanized or nickel-plated. It is also possible for the components to be tempered. Long-term nitriding is possible, whereby a nitriding depth can be brought about. As a result of the laterally open receptacle 8, the bearing surfaces 13, 14 can be produced, for example, by milling, with the result that the quality of the bearing surfaces 13, 14 is improved, the wear is reduced and there is a lower frictional force. This can have the result that the clamping force brought about with an exemplary (actuating or) tightening torque at a certain level for the clamping screw 27 is increased by up to 50%. The bearing surfaces 13, 14 preferably have a radius.

The bearing shoe 1 can be produced from a plate-shaped semi-finished product.

The fact that the receptacle 8 is open at the side also makes it easier to clean the receptacle 8 in the event of soiling, and less soiling is deposited in the receptacle 8 in any case.

For an alternative embodiment, the base body 2 of the bearing shoe 1 is also designed with a continuous milling or recess in the area of the clamping surface 43, so that a clamping plate 44 of the clamping screw 26 is not on the bearing shoe 1, but rather through the bearing shoe 1 on the tensioning rail 27, the clamping screw 26 then extending through the said recess of the bearing shoe 1. A material is preferably used which has a very high tensile strength. The material can be spring steel.

For the embodiment shown, the clamping lever 20 has two lateral bearing pins 15, 16, which extend laterally outward from the web 45 and on the fork-like bearing arms 51, 52 of the bearing shoe 1, each with a bearing surface 13, 14 for an associated bearing pin 15, 16 are supported.

For another embodiment, likewise encompassed by the invention, the bearing shoe 1 can only have a central bearing arm instead of the fork-like design of the bearing arms 51, 52. In this case, the clamping lever 20 is designed with two fork-like webs. A single bearing pin can then extend between the webs of the clamping lever 20, which can be formed, for example, by a bearing pin inserted in the bearing eyes of the webs or a bearing pin screwed into the webs and extending in the lateral direction. This single bearing journal of the tensioning lever 20 can then be supported on the single bearing arm of the bearing shoe 1.

REFERENCE LIST

1

Bearing shoe

2

Base body

3

rib

4th

rib

5

Longitudinal recess

6th

Recess

7th

Recess

8th

admission

9

Side wall

10

Side wall

11

Angulation

12th

Angulation

13th

storage area

14th

storage area

15th

Journal

16

Journal

17th

storage area

18th

storage area

19th

Swivel axis

20th

Tension lever

21

thickening

22nd

thickening

23

Support surface

24

Support surface

25th

Clamping tool

26th

Clamping screw

27

Tensioning rail

28

Long hole

29

Longitudinal axis

30th

Support surface (above, bearing shoe)

31

Support surface (above, bearing shoe)

32

Support surface (below, bearing shoe)

33

Support surface (above, tensioning rail)

34

Support surface (above, tensioning rail)

35

Support surface (below, clamping rail)

36

Crank

37

Clamping lever part

38

Clamping lever part

39

Clamping jaw

40

Through hole

41

Threaded hole

42

Front side

43

Clamping surface

44

Clamping plate

45

web

46

Imprint

47

bevel

48

Crossbar

49

Crossbar

50

Crossbar

51

Bearing arm

52

Bearing arm

53

rib

54

Threaded hole

55

chamfer

56

chamfer

57

step

58

step

59

Recess

60

Groove

61

Undercut

62

Undercut

63

Base leg

64

Side thighs

65

Side thighs

66

Crossbar

67

Crossbar

68

Support surface

69

Support surface

70

Insertion opening

71

ground

Claims (18)

1. Clamping tool (25) comprising

   a) a clamping rail (27).

   b) a bearing shoe (1) which is supported for being displaced along a longitudinal axis (29) relative to the clamping rail (27),

   c) a clamping lever (20) which is supported by two lateral bearing journals (15, 16) for being pivoted by an accommodation (8) formed by the bearing shoe (1) and

   d) a clamping screw (26) which is screwed into a clamping lever part (37) of the clamping lever (20),
   characterised in that

   e) the accommodation (8) formed by the bearing shoe (1) is open at least in one lateral direction.
2. Clamping tool (25) of claim 1, characterised in that in the region of the bearing journals (15, 16) the bearing shoe (1) extends along the outer surface of the bearing journals (15, 16) whereas no material of the bearing shoe (1) is arranged between the front faces of the bearing journals (15, 16) and the clamping rail (27).
3. Clamping tool (25) of claim 1 or 2, characterised in that the clamping lever (20) is laterally guided in the clamping rail (27) by a contact of the front faces of the bearing journals (15, 16) with guiding surfaces of the clamping rail (27).
4. Clamping tool (25) of claim 1 or 2, characterised in that

   a) the clamping lever (20) is laterally supported on a lateral front face of the bearing shoe (1) and

   b) the bearing shoe (1) is laterally supported and guided by another lateral front face of the bearing shoe (1) on the clamping rail (27).
5. Clamping tool (25) of claim 1 or 2, characterised in that

   a) bearing surfaces (17, 18) of the bearing journals (15, 16) of the clamping lever (20) and bearing surfaces (13, 14) of the bearing shoe (1) comprise a step (57, 58) and the clamping lever (20) is laterally guided relative to the bearing shoe (1) by the at least one step (57, 58) and

   b) the bearing shoe (1) is laterally guided in the clamping rail (27) by a contact of a lateral side surface of the bearing shoe (1) with a guiding surface of the clamping rail (27).
6. Clamping tool (25) of one of the preceding claims, characterised in that the bearing surfaces (13, 14) of the bearing shoe (1) comprise a chamfered edge (55, 56).
7. Clamping tool (25) of one of the preceding claims, characterised in that the bearing shoe (1) comprises

   a) a base body (2) in particular having planar parallel upper and lower surfaces and/or

   b) two cranked bearing arms (51, 52) which form the bearing surfaces (13, 14) for supporting the bearing journals (15, 16) of the clamping lever (20) for being pivoted.
8. Clamping tool (25) of claim 7, characterised in that the upper surfaces of the bearing arms (51, 51) comprise supporting surfaces (30, 31) which preferably have a planar design and/or have an orientation parallel to a supporting surface (32) formed by the lower surface of the base body and by which the bearing shoe (1) is supported in upper direction on the clamping rail (27).
9. Clamping tool (25) of claim 8, characterised in that the bearing surfaces (13, 14) of the bearing arms (51, 52) and the supporting surfaces (30, 31) of the bearing arms (51, 52) have a lateral overlap of at least 50 %.
10. Clamping tool (25) of one of claims 7 to 9, characterised in that the bearing arms (51, 52) and the base body (2) are connected to each other by ribs (53).
11. Clamping tool (25) according to one of claims 7 to 9, characterised in that the base body (2) and the bearing arms (51, 52) have the same material heights.
12. Clamping tool (25) of one of claims 7 to 9 or of claim 11, characterised in that the bearing shoe (1) is manufactured from a plate-shaped semi-finished product.
13. Clamping tool (25) of claim 12, characterised in that

    a) a recess (59) is formed into the front side of the semi-finished product, the recess (59) being limited in lateral direction by the bearing arms (51, 52) and

    b) the bearing arms (51, 52) have a cranked design caused by a plastic deformation.
14. Clamping tool (25) of one of claims 7 to 13, characterised in that the bearing surfaces (13, 14) of the bearing arms (51, 52) of the bearing shoe (1) are continuous or open in lateral direction.
15. Clamping tool (25) of claim 14, characterised in that the bearing surfaces (13, 14) of the bearing arms (51, 52) of the bearing shoe (1) are manufactured by machining or metal-cutting.
16. Clamping tool (25) of one of the preceding claims, characterised in that one end region of the clamping screw (26), in particular a clamping disc (44) of the clamping screw (26),

    a) is guided with one degree of freedom along a longitudinal direction of the bearing shoe (1) relative to the bearing shoe (1) and

    b) is captured or held without a play or with some play in both movement directions of the clamping screw (26) at the bearing shoe (1).
17. Clamping tool (25) of one of the preceding claims, characterised in that the clamping tool (25) does not comprise an opening spring.
18. Clamping tool (25) of one of the preceding claims, characterised in that the bearing shoe (1) is guided on both sides in guiding grooves of the clamping rail having a cross-section corresponding to a lying U, the bearing shoe (1) in the region of the bearing journals (15, 16) of the clamping lever (20) and in a cross-section exclusively extending above the bearing journals (15, 16) and below the upper side legs of the lying U.

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