DE8609423U1 - Measuring and / or scribing device - Google Patents

Description

Measuring and / or scribing device

The invention relates to a! ⁷ IeB and / or scribing device of the type mentioned in the preamble of claim 1.

In a known device of this type (DE-PS 26 13 451) has the compensation device inside the column is a counterweight on, which is attached directly to the pull rope and is contained within the column so that it can move freely. The counterweight is there made of lead. This has the disadvantage that it makes the column and thus the entire measuring and / or marking device relatively heavy will. There are large ones that need to be accelerated or decelerated Crowds. This is particularly detrimental when such measuring and / or scribing devices are particularly large To enable working speeds when measuring and / or scribing, especially with CNC-controlled machines of this kind. It is also disadvantageous that it is free in the interior of the pillars hanging compensation weight when moving the device inside the column and swing back and forth from the inside can strike against the column. This not only results in uncomfortable Noise, but can also cause the column to be deformed or damaged. Γ. ·· -particularly when relatively far down moving cross slide and accordingly located relatively high up Kömpsrisationsgewicht has this free pendulum movement of the The cumulative weight also has the disadvantage that it

The column is stimulated to vibrate more strongly. The pendulum movements of the compensation weight affect the accuracy of the measuring device in any case and, depending on the height of the compensation weight, generate additional vibrations in the column. The production The lead compensation weight brings with it certain problems. Lead dust, lead shavings and fall the same lead material waste, which is polluting and also harmful to the health of the workforce. could be. For that reason alone, one strives to be as close as possible

of lead as a material for the compensation weight from B

received, but so far was not replaceable. From f |

Adjustment problems are also disadvantageous; because with it the weight compensation is achieved to some extent, all the parts, the weight of which is to be compensated, must i.e. cross slide, cross arm, pick-up head including tools to be used in it, are weighed beforehand, so that you know their weight and then edit the compensation weight accordingly.

These measurement and adjustment work and subsequent assembly work, as a result, are time-consuming and expensive. Nevertheless, a weight adjustment and therefore weight relief can only be achieved within limits; because as soon as When handling the device, another tool with a different weight is used, the one to be compensated changes Total weight, so that the compensation is then only inadequate or no longer given, depending on changing weight on the tool side. A subsequent one Weight adjustment to changing tool weights is not possible.

The invention is based on the object of providing a measuring and / or scribing device as described in the preamble of claim 1 Art to create in which the difficulties identified with regard to the Kompensationseirichtung are eliminated, in particular a weight saving and an increase in measurement accuracy is achieved, with the

Possibilities for a more sensitive adaptation to yourself changing weights to be compensated, e.g. when changing tools, are created, and the device is simpler can be manufactured, assembled and adjusted.

In the case of a measuring and / or scribing device of the type mentioned in the preamble of claim 1, the object is achieved according to the invention by the features in the characterizing part of claim 1.
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Such a pressure cylinder for weight compensation requires previous compensation weights, especially made of lead, no more. This eliminates all initially associated with such weights.

• 1 & described disadvantages. Nothing can happen inside the column to swing back and forth more freely and strike from the inside against the Sä-jle and especially when it is relatively high Stand inside the column stimulate the column to additional vibrations and in general the measurement accuracy affect. The environmental problems associated with lead are also eliminated. Above all is an essential one Weight reduction achieved. This leads to smaller masses to be accelerated and decelerated, whereby the device enables higher working speeds, in particular measuring speeds, and thus overall becomes more effective. This also leads to an increase in the measurement accuracy. It is also advantageous that the individual parts of the device, the weight of which is to be compensated, are no longer costly beforehand Need to be weighed wisely. The device can be installed quickly and easily, the compensation being due appropriate setting of the pressure medium supply of the pressure medium cylinder set quickly and easily e.g. by setting or adjusting a pressure regulator in the pressure medium supply. Elaborate Adjustment work is therefore not necessary for the most exact weight compensation possible.

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that an adaptation to changing weights to be compensated is possible in the same way without any problems. Will .one tool in the tool holder against another If you replace a tool that has a different weight, you only need, for example, the pressure regulator in the pressure medium supply of the pressure cylinder to be adjusted accordingly. This means that it can be adjusted quickly and easily on changing weights to be compensated possible.

Advantageous further developments of the invention result from claims 2-8. Through the design of the pressure medium cylinder As a telescopic cylinder, a considerable weight compensation can be achieved with relatively short columns and small internal column dimensions can be achieved. Due to the

male according to claim 7 is the working length of the compensation device shortened, which is particularly advantageous in the case of relatively short columns if only a single-acting column Pressure cylinder is used.

The safety of a measuring and / or marking device equipped with a compensation device with a pressure cylinder is significantly increased if the features of claim 9 as further essentials in this device Features of the invention are used. By such a Safety braking device ensures that in the event of a failure of the pressure medium supply and omission of the weight relief the relevant relieved device & ile now not move down by itself and cause possible physical injury or property damage.

Rather, it is guaranteed that .jei a failure of the pressure medium supply then the safety brake device automatically detects this and occurs automatically and the compensation device is mechanically blocked.

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Further advantageous features of this safety braking device result from claims 10-25. It is thereby achieved that the safety brake device particularly inexpensive, small, light and compact and without any difficulties, just like the at least one Pressure medium in the compensation device in the hollow inside of the column. With everything, the safety braking device is able to operate automatically address and block in the event of a pressure medium failure and

- * "uouBi σ ü C ι r SciuSü uci Ξ i Π S r ZWcI ι αΰκΕΠ LjnnxGnr \ Ling u85 The pulling rope absorbs the relatively large forces in a braking manner. The safety braking device is light, inexpensive and easy to assemble. You can before the Assembly of the at least one pressure medium cylinder can be combined with it to form a structural unit then installed together with this inside the column.

Further details and advantages of the invention result from the following description.

The full text of the claims is above not reproduced solely to avoid unnecessary repetition, but instead by naming the Claim number is referred to, whereby all of these claim features are expressly stated at this point and to be regarded as being essential to the invention.

The invention is explained in more detail below with reference to an exemplary embodiment shown in the drawings explained. Show it:

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Fig. 1 is a perspective shear view of a three-dimensional measuring and / or scribing device with straightening plate, 5

FIG. 2 is a schematic, partially sectioned side view of only part of FIG Column of the measuring and / or scribing device,

Fi £. 3 sine schsrriatiSj to the tsil gsschnittsns Side view of a safety brake device in the column, g

FIG. 4 shows a schematic section along the line IV-IV in FIG. 3,

Fig. 5 I.

and B is a schematic section and plan view ^hl only the collet chuck of the safety brake mechanism in Fig. 3 and 4.

In Fig. 1, a stationary straightening plate 11 supported by a foot 10 and having an upper plane surface is shown only by way of example 12 shown, on which workpieces to be measured and / or marked can be clamped. The straightening plate $ 11 carries an upper, yyy, on the long side visible here

approximately angled rail 14 and below this a guide rail 15, on and along these a three-dimensional measuring and / or scribing device 16 can be moved along the longitudinal side of the straightening plate 11, namely ^! with a slide 17 with a vertical column 18 held on it, perpendicular to the plane surface 12, on which a cross slide 19 can be displaced, in which a transverse arm 20 is held displaceably in the horizontal direction and thus parallel to the plane surface 12. At the end of the cross arm 20 there is a recording head 21 of a known type for a measuring and / or scribing device.

The cross slide 19 thus carries the cross arm 20 with the receiving head 21 and has a significant " Iiches weight, which can be up to 50 kg or more can.

In another * not shown embodiment the column 18 is on a lower foot similar to the carriage 17, which is on the top of a guide, Straightening plate or the like. is held displaceable in the horizontal direction.

For easy movement of the cross slide with cross arm 20 along column 18 is the cross slide 19 at least substantially relieved of weight by means of a compensation device 22. The column 18 is in Interior hollow. The compensation device 22 is located with at least all essential parts in the hollow Inside the column 18. At the compensation device A pull rope 29, which runs at least partially inside the column 18, engages over the upper end of the column a deflection device 30a there in the form of a deflection roller is deflected and with the outside of the column 18 running, freely visible part up to the cross slide 19 is performed and attacks on this.

The compensation device 22 has at least one pressure medium cylinder 23 within the legs 18. Of the Part of this, here the cylinder housing 24, is solid connected to the column 18. The lower end of the cylinder housing 24 in FIG. 2 is attached to the foot part 25 which also the column 18 is firmly attached. The other, relatively movable part of the pressure medium cylinder 23, here its piston 26 and the piston rod 27 fixed to it are coupled to the pull rope 29.

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The pressure medium cylinder 23 is designed in one stage here. It is designed as a single-acting cylinder, its Piston 26 is acted upon with pressure medium only on one piston surface 28, which is to the upper end of the column 31 points out. This is between this piston surface 28, the inner peripheral surface of the cylinder housing 24 and the upper end cover 32 of which forms a working space 33 to which pressure medium is supplied via a pressure medium line 34 will. The pressure medium enters the working space 33 at the end adjacent to the end cover 32 with dom pressure ρ in the direction of the arrow. Not further shown are control and regulation parts belonging to the pressure medium feed circuit, e.g. valves, pressure regulators and the pressure medium generator.

In the embodiment shown, the pressure medium cylinder z3 designed as a pneumatic cylinder. The pressure medium therefore consists of compressed air. The cylinderfaum, that is formed on the other side of the piston 26 facing away from the piston surface 28 is freely vented to the outside.

The pressure medium cylinder 23 is single-stage here.

In another exemplary embodiment, not shown the pressure medium cylinder is instead designed as a hydraulic cylinder. Furthermore, the Druckmittelzyli-ider

be multi-stage both in the design as a pneumatic cylinder and as a hydraulic cylinder, e.g. as a telescopic cylinder be designed.

As FIG. 2 shows in particular, the piston rod is 27

at the upper end of the cylinder housing 24 closed off by the end cover 32. At the free At the end of the piston rod 27, a second deflection device 30b in the form of a deflection roller is also held, which is free is rotatably mounted in a fork screwed to the piston rod 27. This is located within the Column 18. Also arranged at the upper end of column 18

Deflection roller 3Da is held in a fork so that it can rotate freely. The pull rope 29 starts from an upper fixed point 35 at the upper end of the column 31, is then via the second IJm-

steering device 30b with a wrap angle of b

guided about 180 ° and arrives from there to the first deflection device 3Da _1, which is also wrapped around with an angle of wrap of 180 °. From there, the pull rope 29 leads to the cross slide 19. The amount of pressure medium and / or the pressure of the pressure medium in the working chamber 33 is regulated by means of a pressure regulator (not shown) in such a way that a force acts on the piston surface 28 that corresponds to the weight of the cross slide 19 with the cross arm 20 ,. Pick-up head 21 and tool attached to it

each compensated as well as possible, in such a way that 15

the entire unit is held freely floating on the column 18 in practically any position. Included is due to the amount of pressure medium and / or the pressure in the working chamber 33 by simply adjusting the pressure regulator

a very simple, quick and sensitive adjustment 20

changing weight forces to be compensated possible, which change due to the fact that different tools are inserted into the receiving head 21 depending on the measuring task which have different weights, whereby the total weight of cross slide 19 with cross arm 20

and pick-up head 21 including the tool seated therein changes. The pressure cylinder 23 is particularly easy to move, which is also the weight compensation benefits and allows the device 16 to be handled with as little effort as possible *

The compensation path is reduced by the two deflection devices 30a and 30b. It goes without saying that the inner UmlenkvorrichLü ■ ^ 30b can also be omitted,

depending on the length of the column 18. Then it engages over the 35

upper deflection device 30a guided pull rope 29 directly on the piston rod 27. The column 1B is at least partially relieved of the compensation weight> What

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the accuracy increases. The compensation device 22 is in particular in the area of the column 18 to record a considerable weight saving, as a result of which there is less to be accelerated with regard to the column 18 and masses to be decelerated when the column 18 is moved with the carriage 17. The device 16 therefore enables higher measuring speeds, which is especially true for fully motorized devices with CNC control is beneficial. The compensation device 22 enables a simple one in the manufacture of the device 16 and inexpensive manufacture, assembly and adjustment. It is no longer the weight of the individual components that matters which do not have to be weighed. Nor is it necessary for one inside the column 1 β to be attached compensation weight now its weight to be very precise on the other weights to be compensated. The compensation device 22 becomes simple assembled and then set the compensation force by adjusting the pressure regulator. This diminishes the manufacturing and assembly costs and reduces the effort for adjustment considerably. It is also advantageous that all the disadvantages associated with the compensation weight made of lead, which is otherwise arranged within the column 18, are eliminated. The compensation device 22 is stationary within the column 18 and cannot move in the transverse direction move freely and hit the column 18 from the inside. This enables the measurement accuracy to be increased. from Another advantage is that the upper end of the column 18 is no longer exposed to vibrations to such a considerable extent that would otherwise be recorded with the compensation weight oscillating back and forth inside.

If the cross slide 19 is raised in FIG. 1, then Via the pressure medium line 34 pressure medium into the working space 33 introduced in a corresponding amount and / or with a corresponding pressure «If the cross slide 19 in Fig.1

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^ "is moved downwards, the pull rope 29 is the Piston rod 27 pulled up and pressure medium from piston 26 displaced from the working chamber 33 through the pressure medium line, the outflow quantity and / or the pressure can be set to the required dimension by the pressure regulator,

If the pressure medium supply fails, the cross slide 19 is prevented from falling. Serves for this a arranged inside the column 1ß safety brake device 36 on the pressure medium cylinder 23, the between the cylinder housing 24 on the one hand and the piston rod 27 on the other hand is effective and in their in Fig.3 The release position shown releases the piston rod 27 for translational movement, but not in one Braking position shown the piston rod 27 against translational movement locks. Details of the safety brake device 36 can be seen in particular from FIGS. 3-6 evident. The safety brake device 36 is acted upon by the same pressure medium with the pressure P (Fig. 3).

beats, with which the pressure medium cylinder 23 of the compensation device 22 is fed. So that is Safety braking device 36 under the same pressure held in their release position (Fig. 3). If the pressure in the working chamber 33 drops below a predetermined value

On the other hand, the pressure of the safety brake device 36 also falls in the same way as the minimum value automatically falls into its braking position.

The safety brake device 36 has at least one SO piston 37, which is designed as a disk and contains a slide ring 39 and a sealing O-ring 40 in an inner groove 38 and, in the same way, in an outer groove 41 a slide ring 42 and a sealing O-ring. Includes ring 43. The piston can be acted upon by the pressure medium on one side only on the piston surface 44, and in doing so against the action of axially acting disc springs 45. The piston 37 works axially

* Tendon 46, here from one of the piston rod penetrated collet 47 is made. The collet 47 works directly on the piston rod 27.

The piston 37 is located in an approximately pot-shaped Brake housing 48, which is in the area of the bottom 49 of the The piston rod 27 is penetrated and is arranged coaxially to it. The brake housing 48 is adjacent to the base 49 End by means of a flange 50 there directly on the upper end cover 32 of the cylinder housing 24 flanged by means of screws 51.

At the end facing away from the cylinder housing 24, the brake housing 48 is closed by means of a cover 52, which carries a central, inner and approximately tubular guide section 53 through which the piston rod is passed through. Between the cover 52 and the cylindrical brake housing wall 54 is located for Sealing an O-ring 55. In the cover 52 is a pressure

^ O Mittelkänal 56 contained in one between the Lid 52 and the piston surface 54 formed axial pressure chamber 57 opens. Is on the pressure medium channel 56 a pressure medium feed line 58 is connected, which carries the same pressure medium as the pressure medium line 34.

If via the pressure medium line 34 pressure medium in the Working space 33 is initiated and thus the compensation device 22 is functional, will be the same Pressure medium with the pressure ρ at the same level or with a slightly varied pressure also via the pressure medium feed

SQ line 58 and the pressure medium channel 56 introduced into the axial pressure chamber 57, where it acts on the piston surface 44 and moves the piston 37 in FIG. 3 downward against the action of the disc springs 45. The piston is guided with its inner peripheral surface and the sliding ring on the outer peripheral surface of the guide section and is displaceable * With the outer peripheral surface, the piston 37 is on the inside of the brake housing.

Wall 54 out and sealed there.

The collet 47 is held in the brake housing 48 and in the braking position (not shown) with a radial one ° Clamping force can be applied, which in the event of a pressure drop by means of |

an axial movement of the piston 37 under the action I.

the springs 45 in Fig. 3 can be generated upwards. With its -, closed,;, end 59 located at the bottom in FIGS. 3 and 5, the collet 47 is axially and radially in one | Ring seat BO held in the bottom 49 of the brake housing 4B. |

The other, opposite and slotted end 61 the collet 47 can be supported axially at the free end of the guide section 53, but can rebound radially. For springing in and out of the

1 "formed tongues of the collet 4 / 'at this end 61 the collet 47 is here surrounded by at least one actuating member 62. The actuating member 62 here consists of a resilient star washer 63 of the type also known as" ring clamping "star washer. These are spring washers, roughly meandering in the circumferential direction, which enable a force-fit connection by means of radial bracing of their cylindrical outer circumferential surface 64 against their cylindrical inner peripheral surface 65 seated on collet 47 in the region of end 61, these spring washers being approximately V-shaped outer Contain slots 66 and approximately radial inner slots 67. The at least one star washer 63 has an inclined position roughly like a plate spring when the safety brake device 36 is in the release position according to FIG and in a position other than input riff can be moved with the collet 47. Drop in pressure in the pressure chamber 57, the star wheel 63 is under _he d action of the relaxing springs 45 displaced axially in opposite directions and in a position in engagement with the collet 47th

On the side of the piston 37> that of the pressure chamber 57 is opposite, there is a piston 37 in the brake housing 4b guided sleeve 6B, which with its outer peripheral surface on the inside of the brake housing wall 54 is slidably guided. The sleeve 6B contains

the side facing downward in FIG. 3 has an annular recess 69, into which the disc springs 45 engage and in which they are radially guided and axially supported. The other end of the disc springs 45 is supported on the floor iÖ 49.

On its side facing the piston 37, the sleeve 68 contains a recessed ring seat 70 in which the Star disk 63 held and with its outer circumferential surface 64 is supported. Located in the area of the ring seat 70 axially between the sleeve 68 and the piston 37 Pressure ring 71. This presses axially against the star disk 63 in the axial area adjacent to the outer circumferential surface 64, whereby the star disk 63 is held in the ring seat 70.

In the release position shown in Fig. 3, the piston surface 44 with the pressure medium is under the pressure ρ applied. The piston 37 is at least slightly in FIG. 3 axially shifted downward with accompanying displacement of the sleeve 68 against the action of the disc springs 45. This axial | acts via the pressure ring 71 Pressure force from the piston 37 also on the axial area, the the outer circumferential surface 64 of the star disk 63 adjacent is. The star disk 63 is thus displaced axially downward in the area of its outer circumferential surface 64 in FIG. This has a greater inclination in relation to the plane of the piston 37 with the effect that the inner circumferential surface 65 of the star disk 63 does not exerts a pressure force directed radially from the outside inward on the slotted end 61 of the collet 47. The collet 47 does not exert any clamping force on the piston rod 27.

If the pressure medium supply fails via the pressure medium line 34 ″ to the compensation device 22, the pressure medium feed also falls via the pressure medium feed line 58 to Druäkraurn 57 from * The piston surface 44 is not more loaded. This allows the piston 37 over the relaxing disc springs 45 and the sleeve 68 in Fig. 3 are moved axially upwards. With the shift of the sleeve 68, its ring seat 70 is also displaced relative to the non-displacing guide section 53 on the cover 52 the star disk 63 changed, which now snaps into an approximately diametrical plane. In the area of the inner peripheral surface 65 of the star disk 63 is now a radial pressure force directed from the outside inwards, which acts on the slotted end 61 of the collet 47, which in this area around the piston rod spanned. The piston rod 27 is now relative to the brake housing 48 and thus to the cylinder housing 24 against axial Relative displacement blocked. The tension exerted

is sufficient to now the entire, so far through the compensation device 22 compensated weight of the cross slide 19 with Querarrn 20, recording head 21 and therein to hold the tool located. Through this automatic Incidence of the safety braking device 36 at

compressed air failure is guaranteed that then the Cross slide 19 with cross arm 20 does not fall down by itself and cause injuries or damage. The safety braking device 36 is simple. It is so small axially and radially that it

^{There is} space in the interior of the column 18, whereby they are attached to the pressure medium cylinder 23 at the end in a particularly simple manner, and can therefore be preassembled together with the latter. As a result of this safety brake device 36, the particular advantages of the compensation device 22 with a pressure medium cylinder can therefore be used to the full.

Claims (1)

Expectations 1. I ⁷ IeB- and / or scribing device, with a vertical, inside hollow column (18) on which a cross slide (19) is arranged vertically freely displaceable, which by means of a compensation device (22) at least essentially is weight-relieved, which is contained in the interior of the column (16) and engages the cross slide (19) via a pull rope (29) which is guided at the upper end of the column (31) via a deflection device (30a), characterized in that the compensation device (22) has at least one pressure medium cylinder (23) in the column (18), one part of which, in particular the cylinder housing (24), is firmly connected to the column (18) and the other part, in particular a piston, which is movable relative to it (26) with piston rod (27), with the pull rope (29) is coupled. 2. measuring and / or scribing device according to claim 1, characterized in that the pressure medium cylinder (23) is designed as a pneumatic cylinder. «Β 3. measuring and / or scribing device according to claim 1 or 2, characterized in that the Pressure cylinder [23] is designed in one stage. 4. measuring and / or scribing device according to claim 1 or 2, characterized in that the Multi-stage pressure cylinder, preferably as a telescopic cylinder, is formed. 5. Measuring and / or scribing device according to one of the claims 1-4, characterized in that the pressure cylinder [23D as a single-acting one Cylinder is formed, the piston (26) of which only on the one, pointing to the upper Säuienende [31] Piston surface (28) is acted upon with pressure medium. 6. measuring and / or scribing device according to claim 5, characterized in that the piston rod (27) is led out of this at the upper end of the cylinder housing (24). 7. Measuring and / or scribing device according to one of claims 1-6, characterized by a second deflection device (3Db) provided inside the column (18) and held at the end of the piston rod (27) is, wherein the pull rope (29) from an upper fixed point (35) at the upper end of the column (31) extends over the second deflection device (30b) is guided and by there to the first deflection device (30a) at the upper end of the column (31) and from there to the cross slide (19) is led. 8 <measuring and / or scribing device according to one of claims 1 - ¹ 7, characterized in that each deflecting device (30a, 30b) has a deflecting roller rotatably mounted in a fork. 5 9. measuring and / or scribing device according to claim 1, characterized by a safety brake device (36) within the column (18) on at least one pressure medium cylinder (23), which is between the Cylinder housing (24) and piston rod (27) is effective and in their release position (Fig. 3) the piston rod (27) releases the piston rod (27) against translational movement in its braking position locks. 10. Measuring and / or scribing device according to claim 9, characterized in that the Sicherheitshe.itsbremseinrichtung (36) acted upon by the pressure medium of the pressure medium supply of the pressure medium cylinder (23) and f under the pressure of the pressure medium in their release ■ position (Fig. 3) is held, on the other hand automatically when the pressure drops below a predetermined minimum value falls into its braking position. 11. measuring and / or scribing device according to claim 9 or 10, characterized in that the j Safety braking device (36) one on one side and j against the action of at least one spring (45) from the pressure fi has medium acted upon piston (37) which axially S on a tendon [62,63,46,47) working on I. the piston rod (27) works. 12ϊ measuring and / or scribe device according to claim 11, as characterized by, that the piston (37) in one end connected to the cylinder housing (24) and held thereon brake housing (48) \ ■ i is kept slidable and sealed. tit * · ■ *
I t * ff = 4 - ι * 13. measuring and / or scribing device according to claim 12, characterized in that the Brerns housing (46) coaxially to the cylinder housing (24) j is arranged and is flanged to this end and that the brake housing (4B) is penetrated by the free end of the piston rod (27). 14. Measuring and / or scribing device according to claim 12 or 13, characterized in that the 1Ö brake housing (4B) facing away from the cylinder housing (24) End is closed by means of a cover (52) which has an inner, from the piston rod (27) interspersed guide section (53), the outer peripheral surface of which has a guide seat for the piston (37) forms in the brake housing (48). 15. Measuring and / or scribing device according to claim 14, characterized in that in the cover (52) of the brake housing (48) a pressure medium channel (56) is contained in the between the lid (52) and the piston (37) formed axial pressure chamber (57) opens out and to which a pressure medium feed line (58) is connected. 16. Measuring and / or scribing device according to one of the claims 11 - 15, characterized in that the piston (37) is designed as a disc, with their outer circumferential surface compared to the Inner surface of the brake housing wall (54) is sealed and displaceable along this. 17. Measuring and / or scribing device according to one of claims 11-16, characterized in that that the clamping member (46) has a collet (47) penetrated by the piston rod [27), which in the Brake housing (48) is held and applied in the braking position with a radial clamping force is that in the event of a pressure drop by means of an axial movement α β ac te 9 es ce of the piston (37) under the action of at least oinen spring (45) can be generated. 18, measuring and / or scribing device according to claim 17> characterized in that the collet (47) with its closed end (59) axially and radially in an annular seat (BO), preferably in the bottom (49), of the brake housing (4B ) and that the opposite, slotted end (61) ^{AU of} the collet (47) can be supported axially on the cover (52), preferably at the end of the guide section (53), but can be rebounded radially. 1 ¹ S. measuring and / or scribing device according to claim 17 or 1B, characterized in that the collet (47) at the slotted, rebounding end (61) is surrounded by at least one actuating member (62), which from the piston (37) when it is one-sided Pressurization against its at least 20 '. a spring (45) is axially displaceable and disengaged from the collet chuck (47) when the pressure medium drops under the effect of the at least one spring (45) axially in opposite directions and displaceable into a position in engagement with the collet (47) is. 20. Pleß- and / or scribing device according to claim 19, characterized in that the actuating member (62) as a resilient star washer (63) is trained. .21. Measuring and / or scribing device according to claim 19 or 20, dad u rch characterized in that the actuating member (62) as in the circumferential direction approximately meander-shaped spring washer is formed, a force-fit connection through radial bracing of its cylindrical outer circumferential surface (64) against their cylindrical inner circumferential surface (BS) sitting on the collet (47). 22. Measuring and / or scribing device according to one of claims 11-21, characterized in that that the piston (37) is on the side opposite the piston surface (44) acted upon by pressure medium, is acted upon by an axial spring force, in particular by disc springs (45). 23. Measuring and / or scribing device according to one of the claims 11 * 22, thereby marked, that on the side of the piston (37) which is opposite the piston surface (44) acted upon by pressure medium, a sleeve (68) guided in the brake housing (4B) and on which the axial spring force acts, in particular the TellBrfedern (45) on the other hand on the brake housing (4B) are supported. 24. Measuring and / or scribing device according to one of claims 20-23, characterized in that that the sleeve (BB) on the side facing the piston (37) has a recessed ring seat (70) in which the star washer (63), in particular the spring washer, held and supported with its outer peripheral surface (64) is. 25. Measuring and / or scribing device according to claim 24, characterized by one in the area of the ring seat (70) axially between the sleeve (6B) and the piston (37) arranged pressure ring (71), the axially against the star washer (63), in particular the spring washer, in the area adjacent to the outer peripheral surface (64) Axial area presses and holds it in the ring seat (70).