DE2114004A1 - Clamping device - Google Patents

Description

Patent attorneys DIpL -. 'Nc *. ; 7. R. '. ETZ sen.

Dr. . . . ·. -.:.·.::Τ z jr. 82-16.8O2P (16.8O3H) March 23, 1971

t Mttnehan £ 2, Sleinederfetr. tO

GORLE-WHITE COMPANY LIMITED, Coventry (Warwickshire), Austria.

Clamping device

The invention relates to clamping devices, in particular yrifc.nrnoacken for sliding along a shaft in a desired Kl ^ rn-nstellung and securing on the shaft as well as exerting an Xlemmkraf o, which the shaft counteracts, with an elongated 3-neck part with a shaft receiving opening at its one end area and a clamping plate at its other end region for exerting the clamping force on a workpiece in a longitudinal direction of the shaft.

complete clamping jaw unit can consist of a shaft and two interacting clamping jaws, but alternatively only a single jaw for clamping a workpiece a solid base. The invention relates to both on eixizelr.e clamping jaws as well as on complete clamping

egg 14009/70 Tpo-t (7)

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A complete jaw assembly usually includes one reactive jaw, which remains stationary while clamping pressure is applied, and an active jaw, of which at least a part is printed against the workpiece in order to clamp it. In the application the words "active" and "reactive" are used applied to jaws with the meaning given in this paragraph.

One known method is to anchor an active jaw on a shaft by pivotably mounting the active jaw at a point between its end regions around a Bar teeth running along one side edge of the shaft is arranged with the jaw angularly about the pivot point moved by mechanical means such as a screw in the jaw, the end of which is at the opposite end The side edge of the shaft. The rotation of the screw in one direction causes the jaw to rotate to apply a clamping force. This shape of the jaw is, usually Called "GrARVER" jaw,

A disadvantage of this arrangement is that due to the spacing an initial coarse adjustment between the individual teeth on the shaft the position of the active jaw, which is determined by the positions of the teeth, is often insufficient to keep the jaw moving Bring the jaw in contact with the workpiece or really close to the workpiece, allowing excessive movement the screw (and therefore the movable jaw) is required to achieve the final clamping position, therefore the arrangement is unsuitable as a fast acting mechanism. Another disadvantage of this arrangement is the Cost of producing the rack.

As an alternative solution, it has been proposed to form the active clamping jaw near one end with a collar or ring, which the

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Shank surrounds, and a clamping plate on a screw pin to it hold, which is arranged in a threaded hole near the other end of the jaw; the clamping plate provides the work surface the jaw.

The initial rough adjustment of the jaw is done by sliding it along the shaft. With subsequent Rotation of the screw pin in one direction to press the clamping plate against the workpiece creates a reaction, which adjusts the jaw angularly relative to the shaft, whereby it is achieved that a group of diagonally opposite corners of the collar or ring detected by friction opposite surfaces of the shaft so as to To generate reaction force that causes the final clamping between the jaws.

With this structure, the effectiveness of the blocking effect on the shaft increases with an increase in the ratio between the effective axial length of the collar, i.e. the distance in one direction along the shaft between the diagonally opposite ones Corners of the collar and the distance between the opposing faces of the shaft. However, the effective axial length of the collar cannot be reduced to a small distance as the jaw must be suitable for use in operation withstand occurring loads. These two conflicting requirements detract from the value of this design.

Another disadvantage of this type of jaw is that the application of a vibratory or shock movement to the jaw or the workpiece against which it rests causes the fixed frictional abutment of the collar or ring to be overcome and the consequent movement of the collar or ring under the action of the resilience of the material to a reduction or leads to a total loss of clamping force.

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The invention has for its object a clamping jaw as well to develop a clamping jaw unit in which the friction contact of the clamping jaws on the shaft after their sliding movement Safe means is guaranteed so that any vibration or impact forces that occur do not affect the clamping force.

In the case of a clamping jaw, this task becomes the one mentioned at the beginning Kind according to the invention in that the clamping jaw has a first contact piece for frictional contact with that of the clamping plate facing side of the shaft and a second contact piece for frictional contact on the side facing away from the clamping plate in a position along the shaft in the direction of the clamping force from the first contact piece, which tar.lageoberflache with a Schaf is provided with projections of a considerably narrow radius, which during the clamping process of elastic deformation the shaft surface to the tips or ridges of the projections on the first contact piece corresponding recesses to serve.

Both contact pieces preferably have: shaft contact surfaces with projections, e.g. Ribs of considerably narrow radius, aie during the clamping process of the elastic deformation of the shaft surface to the tips or ridges of the projections the contact pieces corresponding recesses serve.

Due to the nature of the frictional mutual abutment between the first contact piece or the contact pieces and the; Shank can be an extremely good relief system between egg clamping jaw and thorn S-. ¹ ha ft without damaging the surface ue _t shaft. The use of conventional teeth instead of rounded protrusions would result in substantial damage to the surface of the stem after extensive use as a result of permanent deformation of the stem surface by the teeth. It was found that 3 after the

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Principle, a sufficient friction system

zi? j.bar is, a reliable clamping effect on the clamping jaws to v ^ rloirr n, also in a vibration environment,

I) I ^ * 'Ileinrn, iraf ο can focus on the clamping jaw as a reaction ε force from £ T' - ü: jt, incerning the workpiece against the clamping jaw ar'J- ^ it, in which case the clamping jaw a reaction jaw ict. Alternatively, the clamping jaw can also use a mechanism to press the clamping plate against the workpiece. For this purpose the --rsV- can - "with respect to the oiitaiCtstUck Bactcenteils in a fixed La -? -In et ^f, and the second contact piece can with respect to the iao.-centcilc be oeweglich, said force applying means superiors are serially to move the second contact piece with respect to the cheek part on G '- n Gcnaft. Since this movement leads to a tilting ae-ε .iaoiiefiteils, the second contact piece tenants to the 3v>,. ·: .oowe ^ uHfi oezhe cheek part, urxd man must take precautions that this movement is possible-

Preferably, both contact pieces are with respect to the Baoke part free s'jhv / OiiKb-ar, so that they exactly match the Ooorfläcnen oor: Shank to be aligned, and in the case of a aztivcn jaw they keep this exact alignment unabriUr4 "i ^ of the swiveling of the cheek part.

r, w «i. tucκε D ^ züglich Bacrcenteils of a connecting member, aac fiii ο a ir Ad: ^c ie, the means for moving the .zweiten Konta .-: ti.. around the middle lpurxkt the pivoting movement of the harvesting contact tu ex: - :: aiig brought 1st and at the other end pivotable -U8K carries the second contact tick,

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In practice, the connecting link is expediently designed in the form of two parallel connecting link parts, one part of which is attached to one side of the clamping jaw, the connecting link serves to guide the second contact pin eks so that it assumes a position with an effective clamping function results. It has been experimentally found that in the absence of such a link there is a tendency ₃ for the active jaw to slide as a whole along the shaft during a clamping operation due to the reaction of the clamping force between the clamping plate and the workpiece before a substantial mutual Frictional contact between the clamping plates and the workpiece is achieved. This happens because the friction system between the contact pieces and the shaft tends to be disturbed by the initial part of the clamping process. However, once a substantial clamping force is established, the substantial frictional forces will secure the jaw to the shaft regardless of the existence of the link. Thus, the connecting link is preferably set up with a small amount of free JSplels so that once a substantial clamping force has been built up it becomes free and plays no further role in the operation of the KIe mrnnbaekenvor direction.

In many situations, an active jaw and a reactive jaw according to the invention are associated together used with a single shaft. However, a reactive jaw according to the invention or an active jaw according to the invention can be used of the invention can be used individually under certain circumstances. For example, allows an active jaw to be connected with a fixed shaft to use a Kleattnkraf t exert a reactive jaw on a workpiece by clamping the workpiece against a solid base Shank can be used in a jig to hold some or all of the components that are being worked on.

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to hold regardless of whether the workpiece is against the reactive Jaw is pressed by an active jaw according to the invention.

According to a further development of the invention, an active clamping jaw for sliding along a shaft into a desired one Clamping position and exerting a clamping force which the shaft counteracts, an elongated jaw part with a shaft receiving opening at its one end region and a clamping plate at its other end region for exerting the clamping force on a workpiece in a longitudinal direction of the shaft Friction system of the two contact pieces is provided on the shaft, the first contact piece being articulated on the jaw part and the second contact piece by guide means for free movement relative to the jaw part on an arcuate path the pivot of the first contact piece is guided and side force exertion means for exerting a force on the second contact piece are provided opposite the cheek part towards the shaft, so that the two contact pieces during the clamping process attack with friction on the shaft and the jaw part executes an angular movement with respect to the contact pieces and the clamping force effect on the clamping plate results.

According to another development of the invention, there is a clamping jaw unit provided, the two clamping jaws each with a clamping plate and means for pressing the clamping plates relative to one another comprises, wherein the clamping plates each have a rotatable workpiece engaging part and the two clamping jaws so aligned or alignable that the rotatable parts are freely rotatable about a common axis.

With this device, a workpiece, which is clamped between the two rotatable parts, can rotate without the Clamping effect is disturbed. The same considerations apply to the rotation of a clamping device with respect to a workpiece.

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A relative rotation between a workpiece and a clamping device can occur as a result of acting vibrations, occur, and so the utilization of this latter embodiment of the invention is essential to the proper functioning of a Jaw unit contributing factor in a vibrating environment.

The invention is illustrated by means of one in the drawing Embodiment explained in more detail; show in it:

pig «1 is a perspective view of a clamping device according to the invention;

FIG. 2 shows a section of the clamping device shown in FIG. 1;

5 shows a view of part of the clamping device according to FIGS. 1 and 2 in the direction of arrow III in Fig. 2;

4 shows the surface of a contact piece in detail; and

Fig. 5 shows a modified form of the clamping device according to the invention.

The clamping device according to FIGS. 1 to k comprises a shaft 11, an active clamping jaw 12 and an inactive clamping jaw 15.

The shaft 11 is a length of rolled steel strip and can be, for example, 51 »75 mm wide and 6.55 mm thick. There This standard steel strap is readily available, it is possible to use a choice of shaft lengths in conjunction with the Use the same active and reactive jaws to create either a compact clamping device or a clamping device with a large distance between the jaws. Although it is intended that clamping devices having a. active jaw and one reactive jaw and one If the shaft is to be sold and used as a unit, many users can choose a number of active and passive jaws to buy and this in connection with separately purchased steel

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want to use ribbon. If z.ß. the clamping device is to be built into a clamping device, the clamping device of suitable rectangular cross-section steel strip with a number of active and reactive clamping jaws, which are attached to suitable Places are appropriate,

The reactive jaw IJ consists primarily of two 3andstahlpreßteile 14 and 15, which are fastened to each other leaving a gap by four transverse pins l6. The space between the pressing parts 14 and 15 is slightly larger than the thickness of the shaft II, and most of this excess is picked up by a number of dimples 17, the inner halo the Pre3teile 14 and I5 are pressed inwards. These ' • Dimples guide the active clamping jaw during a sliding movement between the jaw and the shaft. The two pressing parts 14 and 15 together with the pins Io form a Backentfcil.

An oiac.n end portion of the reactive jaw member sits a clamp plate l8, the nc hereinafter ^ n will be described in more detail, at the end portion of ReaktivoaoiCfiiiteils facing away from the clamp plate l8 there are two contact pieces I9 and 21 with respect to the uactcent ^ ilc means of transverse pivot pins 22 or 25

will. The pivot pins 22 and 25 can be held axially by F ^ derklips 20 axially in position d

! ct to Kcnta;; tücx. itjt Vj in the configuration shown at the lower part of the depth aer jaw arranged in the exerts a cjio Klernmplatto 18 downward clamping force on the workpiece. 3EI this arrangement, the first contact piece 21 is actually above the contact piece I9, although a part of the contact piece 21 up to the level of the contact; tücki:? Vj hinabreieht.

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Pig. 4 shows on a larger scale the contact piece I9 and the Details of its surface which rests on the shaft 11 during the clamping process. This shaft contact surface 24 has a Number of lateral ribs or projections 25. These protrusions are shown schematically and not to scale, In terms of fluids, it has been found suitable that the Dimensions are as follows:

Pitch between adjacent projections: 1.52 mm; Depth of protrusions from ridge to root: 2.54 mm; Curve radius of the ridges: 2.54-3.81 mm.

These dimensions, and in particular the pitch and depth of the projections, are not critical and there could be any Dimensions generally be suitable in this order of magnitude. The essential aspect of these dimensions is that the radius of the curve of the burrs should be such that the surface of the shaft 11 by engagement of the clamping process Projecting ribs is elastically deformed. If the curve radius of the protruding back is too small, the kick is exceptional high surface loads, which lead to permanent deformation of the shaft surface. On the other hand, if the The radius of the protruding ribs is immeasurably large, that is Extent of surface deformation very limited, and that between the. Frictional force generated by the shaft and the contact pieces can be insufficient to achieve a sufficient clamping effect, especially in a vibrating environment. The material the contact piece should be sufficiently hard to withstand any significant deformation of the contact piece during operation to prevent. High alloy steel or other, usually Materials used as cutting tool materials are suitable.

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Although the above description of a contact piece has been given with particular reference to the contact piece 19,. The contact piece 21 is of course similar to the contact piece 19, as are the contact pieces of the active clamping jaw 12 are trained accordingly.

Referring again to FIGS. 1 and 2, the contact piece 19 is arranged with respect to one of the transverse pins 16 so that the angular rotation of the contact piece about its pivot pin 22 is limited. This ensures that the surface of the contact piece, which rests on the surface of the shaft 11 is always the surface 24.

The contact piece 21 has a shaft contact surface 26 accordingly the shaft contact surface 24. This surface 26 has a recess at 27 to one of the transverse pins 16 at a distance to let through. A single band spring 28 rests on the back of the contact piece ^ 21 and presses it against the shaft 11. When the shaft is removed, the pin 16 in the recess 27 prevents the spring 28 from touching the contact piece essential way shifts. The spring 28 engages via a further transverse pin 16 and engages around a pivot pin 29 which belongs to the clamping plate l8.

The clamping plate 18 will now be described in detail with reference to FIGS. The clamping plate comprises a pressed steel yoke Jl which has two upwardly directed legs which individually reach past the sides of the outer ends of the steel pressings 14 and 15. The pivot pin 29 passes through aligned holes in the yoke J51 and in the pressings 14 and 15 to pivot the yoke about a transverse axis on the jaw member. The lower part of the yoke connecting the two legs is flat and has a central one

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round hole 32, a freely rotatable clamping disc 33 is mounted in the hole 32 by means of an upwardly directed pin 34. The pin 34 has a head 35 of the same diameter as the general diameter of the pin 34 and a neck 36 immediately below the head. A spring clip 37 through the pivot pin 29 is held, engages the constriction 36 and thus holds the pin 34 of the clamping disc 33 in the hole 32. However, the clamping disc can be removed by pulling straight axially and then re-locked in place. at In many special clamping processes, it is desirable to replace the clamping disk with another workpiece contact element, which is adapted to the shape of the workpiece. The simple clipping and unclipping device of the clamping disc enables this exchange in a very simple way.

The pivot pin 29 has a central part of slightly reduced diameter, and the spring 28 engages around this reduced Diameter part so that it defines the pin 29 laterally.

The active jaw 12 corresponds in many respects to the reactive jaw I3. Where the individual parts meet exactly correspond, they are designated with the same reference numerals as those of the reactive clamping jaw, but additionally point a preceding 1 in front of the reference numbers. So the active jaw comprises two pressing parts 114 and II5, which by a Number of pins II6 are connected, and a clamping plate II8. There are two contact pieces II9 and 121 in the same way.

The fundamental difference between the active and the reactive clamping jaw relates to the assembly of the contact piece II9. This contact piece II9 can move freely with respect to the jaw part. The two pressing parts 114 and 115 have arcuate clearance slots 101 which receive a pin 102 which penetrates the contact piece II9. A pair of connecting

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Connecting link serving connecting levers 103, which are articulated around the pivot pin 123 of the contact piece 121, are also articulated on the pin 102 so that it can move freely on an arc, the center of which is in the pivot pin 123. The arcuate slots 101 come into contact with the pin only at the end points of its movement. A square nut 104 is held in two corresponding square openings in the pressing parts 114 and 115 in a position behind the contact piece 119, and this nut carries a manually operated screw 105 which is screwed into the nut 104 and against the rear side during the clamping process of the contact piece 119 pushes. This rear side of the contact piece 119 has 105 »running the form of a vertical arc-shaped groove, and the end of the screw in this groove, has a corresponding part spherical surface of slightly lesser radius than the groove. This ensures that the contact between screw 105 and contact piece 119 does not prevent relative vertical movement between these parts and that forces between these parts are essentially within a vertical median plane.

The operation of the clamping device will now be described first with reference to the reactive clamping jaw 13. When a workpiece is attached between the two clamping plates 18 and II8, the plate II8 can be made to exert a clamping force, as will be described below. The counterforce of the clamping plate 18 of the reactive clamping jaw reacts to this force. A vertically upward force on the clamping plate 18 in the arrangement shown tends to rotate the reactive jaw about its mounting location on the shaft 11, which in turn generates substantial compressive forces between the contact pieces and the shaft in response to the applied moment. These substantial compressive forces lead to blocking frictional forces in a direction along the shaft that are significantly greater than

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are the force acting on the clamping plate 18, from which it follows that the reactive jaw remains in position regardless of the load acting on the clamping plate. the Spring 28 results in an easy initial gripping of the shaft by the contacts so that the reactive jaw maintains its position even without the action of a load. When a typical clamping load is reached, the Reaction forces between the shaft and the contact pieces sufficient to cause the rib projections 25 (Fig. 4) been pressed into the surface of the shaft and thereby improve the friction system. The deformation of the shaft is elastic nature, so that the surface of the shaft is not damaged. Due to the fact that the contact pieces are pivotably mounted, the forces between the contact pieces and the shaft are evenly distributed over the surface.

The active jaw could be used as a reactive jaw, and in such a case the operation would be as described above for the reactive jaw. However, it is the main intended use of the active jaw to enable a clamping force by moving the clamping plate 118 in one direction towards the Workpiece is brought into action. To effect this clamping operation, the screw 105 is turned in such a direction rotated so that it presses the contact piece 119 against the shaft 11. Viewed in a different way, this screwing process serves to to pull the upper left part (in the drawing) of the active jaw part to the left (in the drawing) away from the shaft. So the entire jaw part comes to rotate about the pivot pin and thereby to exert pressure on the clamping plate 118 against the workpiece. Pressure and frictional forces between the contact pieces 119 and 121 and the shaft 11 according to the equal forces of the reaction jaw develop as

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Result of the rotation of the jaw part and the application of a force to the workpiece by the clamping plate 118. The clamping force can be increased by further turning the screw 105. and the resulting increase in the clamping force on the workpiece leads to correspondingly increasing forces between the shaft and the contact pieces 119 and 121.

During the initial tightening of the screw 105 to create an initial clamping force, in the absence of the connecting links 105 there is the possibility that the active jaw 12 as a whole on the shaft 11 in response to the initial Clamping force on the workpiece before any positive engagement is achieved between the contact pieces and the shaft is, slipped down. It is believed that the balance between the clamping force and the frictional forces during the initial Part of the clamping process due to practical factors such as slight irregularities in the surface between the Screw and the contact piece 119 can be achieved. However, the attachment of the links 103 leads to more secure Holding the contact piece 119 in its desired position, so that it is a simple matter to achieve the required clamping forces. The links 103 take none significant share of the main terminal load, and due to the fact that they have somewhat oversized holes for engaging the associated tenons, they tend to come free and do not accept any load when the clamping force is increased.

A clamping device as shown in Figs. 1 to 4, remains effective even in a vibrating environment despite the fact that it functions based on frictional forces. The nature of the engagement between the contacts and the shaft has been found to withstand vibration without any tendency for the clamping force to be reduced by sliding one or the other jaw along the shaft.

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There can also be a vibration that tends to affect the workpiece rotate, the workpiece rotate freely due to the nature of the clamping plates, and such rotation does not cause the workpiece to be released from the clamping device.

An alternative application of an active jaw according to the invention is shown in FIG. A shaft 51 is on one Worktop 52 fixed by means of a clamping bracket 55. One active jaw 54 is attached to shaft 51. This active Jaw can be used to clamp a workpiece of any height within the limits of shaft 51 to the worktop 52 to be clamped.

Active and reactive clamping jaws according to the invention according to the above Description can be used in a wide range of applications in conjunction with suitable shafts.

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Claims (13)

Claims ί 1. Clamping jaw for sliding along a shaft into a desired one Positioning and plague sitting on the shaft as well as exercising a Clamping force counteracted by the shaft with an elongated jaw part with a shaft receiving opening at one of its end regions and a clamping plate at its other end portion for applying the clamping force to a workpiece in a longitudinal direction of the shaft, characterized in that the jaw has a first contact piece (e.g. 21) for the frictional System on the side of the shaft (e.g. 11) facing the clamping plate (e.g. 18) and a second contact piece (e.g. 19) for frictional contact on the side facing away from the clamping plate in a position along the shaft in the direction of Having clamping force from the first contact piece, which is connected to a shaft abutment surface (e.g. 24) with protrusions (e.g. ribs 25) is provided with a considerably narrow radius, which during the clamping process of the elastic deformation of the shaft surface to the tips or ridges of the projections on the first contact piece corresponding depressions serve. 2. Clamping jaw according to claim 1, characterized in that both contact pieces (e.g. 21, 19) shaft contact surfaces (e.g. 24) with projections (e.g. 25) of a considerably narrow radius. ^. Clamping jaw according to claim 1 or 2, characterized in that that it is designed as a passive clamping jaw (13). 4. clamping jaw according to claim 1 or 2, characterized in that that the second contact piece (e.g. 119) in a direction towards the The shaft (e.g. 11) is movable for the purpose of pivoting the jaw part (e.g. 114, 115) and thus forms an active clamping jaw (12). 1098A1 / 13U 21U004 5. clamping jaw according to claim 3 or 4, characterized in that that both contact pieces (21, 19 or 121, 119) are articulated on the jaw part (14, 15 or 114, 115) and during the clamping process Align exactly to the shaft (11). 6. Clamping jaw according to claim 5, characterized by a spring (28 or 128) for resilient pressing in one direction of rotation and easy application of the first contact piece (21 or 121) to the shaft (11) even in the absence of a load on the clamping plate (18 or 118). 7. Clamping jaw according to one of claims 4, 5 according to 4 or 6 according to 5 and 4, characterized in that the movement of the second contact piece (119) is linked to the jaw part (114, 115) Link (103) is controllable. 8. Clamping jaw according to claim 7 with reference back to claim 5 according to 4, characterized in that the connecting member (103) is articulated on the pivot pin (123) of the first contact piece (121) is. 9. Clamping jaw according to claim l _s, characterized in that the first contact piece (121) is articulated on the jaw part (114, 115) and the second contact piece (119) by guide means (101, 102) for free movement relative to the jaw part on an arcuate path is guided around the pivot pin (123) of the first contact piece and that side force exertion means (104, 105) are provided for exerting a force on the second contact piece towards the shaft (11) opposite the jaw part, the two contact pieces being in contact with the shaft under friction during the clamping process and the jaw part executes an angular movement with respect to the contact pieces and caused the clamping force on the clamping plate (118) 109841 / 13U i ₉ . 21H004 10. Clamping jaw according to one of the preceding claims, characterized characterized in that the clamping plate (l8, 118) on the jaw part (14, 15 or 114, 115) hinged around a transverse pin (29 or 129) and has a removable workpiece support part (clamping disc 35). 11. Clamping jaw according to claim 10, characterized in that the removable workpiece engaging part (clamping disc 33) is rotatable is. 12. Clamping jaw unit with a shaft, characterized by an active clamping jaw (12) according to one of the preceding claims and a passive clamping jaw (I3) according to one of the preceding claims. 13. Jaw assembly with one attached to a base Shaft, characterized by an active clamping jaw (54) according to one of Claims 1, 2 or 4 to 11. 1QS841 / 1314 ι ^ϊ0 ■ ♦ Blank page