DE1427470A1 - Dressing device for grinding wheels - Google Patents

Description

The Cincinnati Milling Machine Co., Cincinnati, Ohio, V.St.A.

Dressing device for grinding wheels

The invention relates to a dressing device for grinding wheels, in particular for use belPrecision grinding machines.

When manufacturing angularly designed ring-shaped ball bearings, a workpiece profile must be ground having an arcuate portion and an adjacent rectilinear portion. It is common practice do not run the straight section exactly tangential to the arcuate section, but between them To leave a small saving on both surfaces, which keeps the balls in the arc-shaped ball track. The arched one Section must be sanded to a depth slightly greater than the depth to which the straight line Section needs to be sanded. Each of these two surfaces is generally made in a separate grinding process manufactured. First is the arcuate ball track

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Track ground and in a subsequent grinding process the straight section is then ground. But it is best to grind both the arcuate ball track section and the flat section in a single operation.

When grinding both profile surfaces in a single one In the grinding process, an exact 'grinding wheel profile must be generated and maintained. This requires exactly Working dressing device that generates a circumferential profile, the parts of which change during successive dressing processes do not change relative to each other. The grinding wheel profile has a small saving between its straight line Section and its arcuate section, then a cam disk guide is very difficult to save. The use of a cam disc also restricts the adaptability of the machine, since a different one for each profile Cam disc must be used.

The invention is therefore intended to create a dressing device with which a grinding wheel circumference existing arcuate section and a subsequent rectilinear section by means of a single one Dressing tool in a single dressing process can be produced without a cam disk guide.

Furthermore, a device is to be created with which an arcuate profile section and an adjacent straight profile intersecting this profile section labschnitt dressed on the circumference of a grinding wheel

will

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can be.

Furthermore, a dressing device is to be created in which the ahn of the dressing tool are changed can, in order to be able to dress several grinding wheel profiles with straight and curved profile sections in this way.

Furthermore, a device for dressing a 'straight profile section and an arcuate profile section be created with a continuous movement of the dressing tool, the device being simple is in construction and inexpensive to manufacture and yet is flawless and accurate during repeated operations is working.

In the case of the preferred form of the inventive Dressing device a dressing tool provided with a single cutting tip is used, which is in a slide is arranged. This carriage performs a reciprocating movement in a bracket, which with respect to the grinding disc is rotatably mounted. A rotating drive part develops a torque that is generated by the dressing device is divided in order to generate a movement of the carriage in the bracket and a rotary movement of the bracket, the bracket remains stationary during the movement of the slide. The relative movements the carriage and the bracket are adjustable to allow movement of the dressing tool over a path to produce, with the an arcuate profile section, the is cut by a straight professional cut, dressed can be used, but with which a profile can also be

. directs

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• ·

■ - 4 -

can be directed, in which the straight profile section runs tangential to the arc section. The device works precisely and the same profile can be dressed repeatedly will.

The dressing device for a grinding machine with a grinding wheel with a composite profile and with a dressing tool which is rotatably arranged near the grinding wheel, characterized in that that a sliding dressing component, in which the dressing tool is arranged, in a rotatable dressing component is mounted and can perform a transverse movement in this component; that the first dressing component is freer is movable than the second dressing component; that the second dressing component after a predetermined movement of the first dressing component is more freely movable than the first dressing component, and that a drive component is a Receives driving force and drives both dressing components in such a way that only one of these dressing components is at a time according to the relative freedom of movement between the-. sen components moved to their straight profile section and an arcuate profile section on the profile to dress the grinding wheel »

The invention is described below with reference to the drawings »

In the drawings is
·. Fig. 1 is a view of the dressing device | FIG. 2 shows a section along line 2-2 of FIG. 1; '.,

■ "■■■., Fig.! ⁵

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Fig. 3 is a section along line 3-3 of Fig. 2;

Fig. 4 is a section showing details of the drive device;

Fig. 5 is a section along line 5-5 of Fig. 4;

Fig. 6 is a schematic representation of the hydraulic Flow circuit for driving the dressing device;

7 shows an illustration of the electrical control circuit for switching the hydraulic flow circuit shown in FIG. 6;

Fig. 8 is a section along line 8-8 of Fig. 3, and Fig. 9 is a partial section of a grinding wheel with the profile of the sole circumference.

The dressing device (Fig. 1) is located behind the grinding wheel Io, which is located in the grinding wheel head Grinding machine is rotatably mounted. The dressing device is carried by a dressing carriage 12, which is from Housing 14 is carried, which is mounted on the grinding wheel head 11 and forms part of this head 11. (The grinding wheel Io rotates on an axis which is stationary with respect to the housing 14 of the grinding wheel head is.) The dressing slide 12 becomes the grinding wheel Io back and forth from the grinding wheel Io through selected Rotation of a compensation spindle 16 displaced, which is axially fixed with respect to the housing 14 and in threaded engagement with the dressing slide 12. By means of the compensation spindle 16, the dressing slide 12 is turned into with respect to the housing 14 to the grinding wheel Io moved to

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to hold the dressing device in a position in which a dressing operation is carried out when the diameter changes the grinding wheel has decreased Io through-wear.

At the end of the dressing slide 12, a support bracket 18 is attached, in which a bracket 2o is rotatably mounted is. The bracket 2o is held in the support bracket 18 by pins 22, 24 which extend from the bracket 2o into the support bracket protrude, in which the pins are in rotary contact with balls 26 and 28, respectively. The balls 26, 28 are in their place ΰοΐ-zen bearings attached to the console 18 in the console 18 3o or 32 held, is located above the bracket 2o In the support bracket 18 there is also a U-gear 34 through which a dressing tool 42 moves during the dressing process will. The transmission 34 is supported by two pistons 30, 38 (Fig. 6) driven, which is located in the rear Ünde the support bracket 18 attached cylinder block 4o move.

The single-tooth dressing tool 42 is carried by the bracket 2o and dressing the grinding wheel Io as it moves over the circumference of the grinding wheel. The dressing tool 42 (i'ig. 2 and 3) is the shifts in the bracket 2o on rolling balls 46% sichauf a carriage 44. The rolling balls 46 are received by the ball bearing structures 48, 5o of the bracket 2o and are held at a mutual distance from one another by ball cages 52, 54. The dressing tool 42 can be moved towards the grinding wheel Io and away from the grinding wheel Io by rotating a spindle 56

ver

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which is supported by a sleeve 58 which has a slot located on the rear side of the bracket 2o bo interspersed. The dressing tool 42 is held in the slide 44 in a fixed Mskels-Tallung. To this end has the dressing tool 42 has a longitudinal slot 62 located in one side (FIG. B), into which a slot in the slide 44 attached wedge 64 engages. If the dressing tool 42 is set in the axial direction so that it has a specific Radius, with the tip of the dressing tool a predetermined distance from that through the centers of the Rotary bearing balls 26, 28 has a going axis, then a ijerrs cn robber 66 tightened to the Yierkzeug 42 in the carriage 44 to hold immobile.

Kiird "the carriage 44 is moved in the bracket 20 and is in this case the bracket is held stationary, then a straight profile cut is made on the grinding wheel Io. If the movement of the carriage 44 in the bracket 2o is interrupted and the bracket 2o is rotated, then it moves the tip of the dressing tool 42 in an arcuate path and in this way aligns an arcuate profile section on the peripheral surface of the grinding wheel Io.

The transmission 34 shown in more detail in FIG. 4 a limited rotational movement is caused by the two reciprocating pistons 56, 38 of the cylinder block 4o (Fi, g. 6) given. With one piston 36, 38 'each, one end is one Ahtriebskette 68 connected, which at their midpoints

one

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a rotatable sleeve 72 is attached. The sleeve 72 ″ is mounted in ball bearings 74, Ib , which are held in a holding disk 77 fastened in the support bracket 18. When the chain 68 moves, the sleeve 72 rotates around the pin 22, around the ball 26 and around the pin bearing 3o At the lower end of the sleeve 72 a gearwheel 78 is fastened by means of a wedge 80 and is held on the sleeve 72 by a thread nut 82. A gearwheel segment 84 which is fastened on the upper end of a shaft 86 is in engagement with the gearwheel 706 which protrudes into the bracket 2o (Fig. 1) and is rotatably mounted in the bracket The lower end of the shaft 86 carries a gear 88 (Fig. 1) which is in engagement with a rack 9o which is on the Buck 'Side of the carriage 44 is located.

By means of this device, the reciprocating movement of the pistons 36, 38 (Fig. 6) is converted into a rotary movement of the sleeve 72 (Fig. 4) via the chain the gear segment 84 is transferred to the shaft $ 6. Shaft 86, gear 88 and toothed days 9o convert the torque into a reciprocating motion of the slide 44. So that the carriage 44 is moved by the 2ahnröd 88, the bracket 2o must have a greater resistance to movement than the carriage 44, since otherwise the bracket 2o is rotated by the rotation of the gear wheel 78. In order to create a resistance, the cone 18

one . _;

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an annular drag seal 92 is arranged, which rests against the annular surface 94 present on the upper side of the bracket 2o. The drag seal 92 does not hold only the Sihleifstaub out of the gear 34, but also creates a resistance to the movement of the bracket 2o which, in conjunction with the rolling balls 46, makes the carriage 44 more mobile than the bracket 2o. As a result, there is a rotation of the shaft 86 in the bracket 2o, so that the carriage 44 is moved laterally in the bracket 2o.

If the movement of the carriage 44 in the bracket is interrupted or stopped before the rotation of the sleeve 72 has been completed, then the residual torque generated on the gear segment 84 rotates the bracket 2o in the Carrying bracket 18. In one side of the bracket 2o there are two stops 98, loo (FIG. 2). In the same Side of the bracket 2o is a. third stop Io2 (FIG. 8), which, however, passes through the slide 44 to the opposite side and which can lie against the bottom or the bottom of a bore Io4 on this opposite side. The stop Io2 (Fig. 2) protrudes the side of the bracket 2o and is covered by a protective cap 96, which is usually used in grinding operations protects the adjustment knob Io2a of the stop. The stop 98 (Fig. 2) is a stationary stop and limits the Movement of the slide44 on the right side of the bracket 2o. The loo stop is an adjustable stop that is on

Job

* '■ £ 809808/0247

Place of the stationary stop 98 is used to reduce the movement of the carriage 44 to the right in the bracket 2o, namely up to a selected point, which is located to the left of the stationary stop 98. In Fig. 2 is located the carriage 44 is in its extreme right position. The left stop Io2 (Fig. 8) is related on the bracket 2o, into which the stop Io2 is screwed, 'adjustable. If the stop Io2 is in his extreme left position, then the extent is lob the permissible movement of the carriage 44 in the bracket 2o. The extent thus indicates the length of the straight path on which the dressing tool 42 can dress the grinding wheel.

It is assumed that, in the embodiment described, the sleeve 72 (FIG. 4) is actuated by actuating the piston 36, 38 (Fig. 6) can be rotated through a pendulum rotation of 18o degrees. Ninety degrees of that movement in one seal are necessary to. the slide 44 (Fig. 2) to move out of contact with the stationary stop 98 over the extent Io6, so that the carriage 44 rests against the left stop Io2. If the carriage 44 rests against the left stop Io2 and is the sleeve 72 (Fig. 4) rotated further in the same direction, then the remaining part of the rotary movement, namely 9o degrees, is transferred to the bracket 2o, see above that the bracket is rotated on an arcuate path. The contact of the stop Io2 by the carriage 44

represents

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- Ii -

establishes the carriage 44 in Mg el 2o. The one through the next continued rotation of the sleeve in the same direction is generated pressure via the stop Io2 on the bracket 2o transfer. The pressure that wants to turn the bracket 2o is greater than the resistance exerted by the drag seal 92 against the movement of the bracket 2o is created. During the continued rotation of the sleeve 72 over the second The bracket can therefore move ninety degrees more freely than the carriage 44.

By the movement of the carriage 44 in the bracket 2o and by the subsequent rotary movement of the bracket 2o For example, the dressing tool 42 is moved on a path which has a rectilinear path section and an arcuate path section Has. The tip of the dressing tool 42 can here be used to dress a grinding wheel Io, the circumference of which has a straight prefil section and has an arcuate profile section. If the stop Io2 (Fig. 8) is set so that the tip of the dressing tool 42 rotates on a radius equal to the perpendicular distance from the center of the fiadiusses to the through the tip is dressed rectilinear path section, then the rectilinear path section is tangential to the arcuate track section. The dressing device can in this case be used to produce such a profile to dress on the circumference of the grinding wheel Io. The Tangtntenpunkt and the center C of the arcuate track section

determine

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then determine a fulcrum centerline CL (Fig. 9) which as a reference line for changes in the ratio of the straight track section to the arcuate track section the path traversed by the dressing tool is used.

If the stop Io2 (Fig. 8) is set so that the movement of the carriage 44 in the bracket 2o at a , The point where the tip of the dressing tool ends 42 (Fig. 3) is rotated by a radius which is greater than the perpendicular Äfesisksxi distance from the center of the radius is to the rectilinear path section, then the rectilinear section dressed by the dressing tool intersects the arcuate section, i.e. the straight section is not tangential to the arcuate section. One The shape of this relationship is shown in FIG. The grinding wheel Io has a straight profile section Io8 and an arcuate profile section Ho. The rectilinear movement of the dressing tool is through the line 112 and is equal to dimension Io6 in FIG. 8. Will take all of the available linear motion. When used, the resulting profile shape has a straight section that is tangent to the arcuate section. However, the stop Io2 is quickly to the right (Fig. 8) adjusts, 'to shorten the path of the carriage 44 by an amount that is equal to the amount 114 and in this way the beginning of the arcuate path from the To offset the center of rotation line CL. Will the rectilinear Movement of the dressing tool 42 interrupted or stylish- '

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then the bracket 2o begins to rotate. The tip of the dressing tool 42 then works on an arcuate path, the radius R of which is greater than the perpendicular distance 116 from the center C of the arcuate section Ho to the straight section of the path. On the grinding wheel periphery, therefore, creates a step that is represented by the magnitude ¹ S, ie, the straight portion IO8 intersects the arcuate portion Ho The surface area 114 of the offset may be relative to the radius of It and the stage S can be expressed by the following equation.: Offset = Ύ R ² - (RS) ²

By calibrating the button Io2a (Fig. 8) of the stop Io2, the puller can be easily adjusted to dress an area of stepped shapes on the grinding wheel.

In the particular implementation described herein, it has been assumed that all rectilinear motion is so large that with complete movement of the carriage 44 a straight surface that is tangential to an arcuate one Surface runs, is dressed. If the slide movement were extended beyond the dimension Io6 (Fig. 8), then the device would dress a rectilinear surface that intersects the arcuate surface, whereby however, no step is created. In this case the offset would be in the opposite direction from the center of rotation

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center line CL and the offset shown in FIG 114 be.

When dressing the grinding wheel shape shown in FIG. 9, the dressing tool '42 is moved from position 118 over a straight path and a subsequent arcuate path and then stopped at position 12o. The dressing tool must then be returned to its starting position 118. This return takes place by reversing the movement of the pistons. 36, 38 (Fig. 6). The sleeve 72 (Fig. 4) is then rotated 180 degrees in the opposite direction. Initially, the carriage 44 moves more freely because the shaft 86 is rotated in a direction in which the carriage 44 is brought out of contact with the stop Io2 (FIG. 8) and is moved to the stop 98 (FIG. 2), the drag seal 92 (Fig. 4) counteracts the movement of the bracket (2o) in the opposite direction. The carriage 44 therefore moves first in the bracket 20 and only then does the bracket rotate into its starting position. During this movement, the dressing tool 42 is moved away from the grinding wheel Io (FIG. 9) and is returned to its starting position 118 without touching the grinding wheel. The dressing contact with the grinding wheel only takes place when the dressing tool 42 moves from the starting position 11b to the stop position or stop position 12o.

So that there is "certainty that the device

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direction always trains the same profile and that the distance ratio of the arcuate peripheral portion and the rectilinear Circumferential section always remains the same, the backward rotation of the bracket 2o to the starting position must always be in terminated at the same distance from the line LG. For this purpose, a stop bolt 122 (Figs. 4 and 5) is in one Fastened cap 124, which is adjustable with respect to the upper oeite of the support bracket and with the support bracket 18 is locked by a screw bolt 126. The stop bolt 122 penetrates an arcuate spacer slot 128 in console 18. The lower end of the stop bolt 122 rests against a stop 13o which is fastened in an angular bearing 132 which is on top of the The bracket 2o sits and moves with the bracket 2o, never Fig. B shows, the stop 13o rests on the stop bolt 122 in the starting position 118. The rotates during the dressing process Bracket 2o in the left direction (seen in Fig. 5) and the stop 13o moves away from the stop bolt 122 when dressing the arcuate section of the grinding wheel circumference he follows. When the bracket 2o is turned back, the stop 13o moves back to the stop pin 122 and rests against the bolt 122. The use of this rigid stop bolt 122 to complete reverse rotation • the bracket 2o then always gives the bracket 2o the same starting position with respect to the line LC. The stops 98, loo, Io2 (FIGS. 2 and 8) in the bracket regulate

the

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142747C

the movement of the slide 44, so that as a result repeated movements of the dressing tool always over an identical or take place in the same path in profile.

A shown in Fig. 7 electric dier cone circuit switches the hydraulic flow circuit of the dressing device shown in FIG. 6. In the initial state , the piston 36 is in the forward position shown and the piston 38 is in its retracted position. At the start of a dressing cycle is • therefore the limit switch · ILS is switched on and the limit switch 2LS is switched off. The switching point of both limit switches 1LS and 2L ^ "is set when the dressing device is set up hired to perform a specific job. This is when the limit switch ILS is switched on Relay 5CR switched on. The switch SW1 is short-termed 'closed to initiate the dressing cycle. During this short closing time of the switch SWt, the relay 1CR switched on via this switch and relay 2CR is switched on immediately via the contacts of relays 1CR and 5 CR. Relay 2CR creates a hold circuit to the contacts of Relay 5CR. Immediately the relay becomes 3CR via the contacts of the relays ICR, 2CR and 6CR, that for usual is closed, switched on. The solenoid 1SOL is then switched on via the contacts of relay 3CR. / ·

When the solenoid 1SOL is switched on, the piston of the reversing valve 134 becomes the one shown in FIG

position

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- IT -

Position shifted to the right. The main pressure line 136 is connected to line 138 in the cylinder block communicates with the left side of piston 36. Line 14o is to return line 142 via valve 134 tied together. The piston 36 is pushed to the right and the piston 38 follows the movement of the chain 68 Left. The sleeve 72 is rotated to the left and the dressing tool begins to move. At the same time will the limit switch 1Lü switched off and the relay 5CR is switched off. The switch SW1 can now be released as the interlocking circuit is switched on via the relays ICR and 5CR (usually closed), relay 1CR holds.

After the pistons 36 and 38 have finished their stroke the limit switch 2LS is switched by the piston 35 and as a result, the relay 6CR is turned on. When relay 6CR is switched on, relay 3CR is switched off and the solenoid 1SOL is switched off. The relay 4CR is at this point via the contacts of relay 5CR (for usually closed), also switched on via relays 1CR and 6CR. Relay 4 CR provides a holding circuit around the contacts of relay 6CR. Solenoid 2S0L is now switched on via the contacts of relay 4CR and the piston of valve 134 is moved to the left. Pressure line 136 is connected to line 14o and the return line 142 is connected to line 138. The movement of the

Pistons

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Piston 36, 38 is reversed to open dressing tool 42 to return to its original position. At the beginning of the return movement if the U-renz switch 2LS is switched off immediately, so that the relay 6CR is switched off. The limit switch 1IS is switched on after the end of the return movement. When the limit switch 1LS is switched, the relay 5CR wiä? D switched on. The relays ICR and 4CR are switched off when the relay 5CR is switched on. When switching off Relay 1CH also turns off relay 2CR, and when relay 4CR turns off, solenoid 2S0L is turned off.

The dressing cycle is then ended. The dressing tool has moved from its starting position to its end position moves and is then at its starting position returned. The length of the straight track section of the dressing tool 42 with respect to the arcuate web cut is determined by the extent to which the carriage 44 can move in the bracket 2o, this üusmass being determined by the setting of the stops loo and Io2 to each other and to the stationary stop 98 and further is determined by the size of the piston 36 and 38 produced rotational movement of the sleeve 72. The position or the relationship of the rectilinear section to the The arcuate section is determined by the setting of the stop Io2 with respect to the rotation center line CL (Fig. 9). .

oind the stops loo, Io2 (j? 'ig. 3 and 2) so

in-

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'S

set so that they hold the carriage 44 in a fixed ο division in the bracket 2o, the entire rotary movement The sleeve 72 (FIG. 4) is transferred to the bracket 2o, which then rotates with the sleeve 72. The stop 122 (Fig. B) is then set in the left direction so that a predetermined amount of arc movement of the bracket over, the point shown can also be done. The entire 180 ° rotation of sleeve 72 can then be used to to turn the bracket 2o through an 18o ° turn and an arcuate one along the entire width of the grinding wheel Io9 (FIG. 9) To train profile. The stop 122 is then moved in the slot 128 to the end opposite that shown End so that a full turn is possible. In the illustration, the stop 122 is in a position that allows the bracket 2o to be rotated through approximately 9o degrees, with one full movement of the carriage 44 over the dimension Io6. The range of rotation of the device described can therefore be any value can be set between 9o and 18o angular degrees. If a radius is desired on the grinding wheel profile that is smaller than 180 degrees and is on the grinding wheel profile if there is no straight section, then the stop 122 will open in the appropriate pitch set an exact starting position. The switching pistons of the limit switches 1LS and 2LS (Fig. 6) must then be like this be set so that they switch the control relays' at the right time, since the pistons 36 and 38 are not full

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Carry out a stroke in the cylinder block 4o.

The specific arching movements mentioned above are only to be used as explanatory examples. values, which are not intended to limit the scope of the invention.

Claims (9)

Claims ·. J Abriehtvorrichtung for a grinding machine with a grinding wheel having a composite profile and with a dressing tool that is close to the grinding wheel "rotatably arranged '," characterized in that a sliding dressing component (44), in which the dressing tool (42) is arranged, in a rotatable dressing component (2o) is mounted and can perform a transverse movement in this component (2o); that the first dressing component (2o) can move more freely is as the second dressing member (44); that the second dressing component (44) can move more freely after a predetermined movement of the first dressing component (2o) as the first dressing member, and that a drive member (72) receives a driving force and so does both dressing members drives that there is always only one of these dressing components depending on the relative freedom of movement between these components moved to a rectilinear profile section and an arcuate profile section on the Dressing the profile of the grinding wheel. 2. Apparatus according to claim 1, characterized j. that the drive device generating the movement . 809808 / 02A7. device (36, 38) is reversible to move the drive part (72), so that the dressing components (2o, 22) move individually in the reverse direction and the dressing tool (42) on return to its original position. 3. Apparatus according to claim 1 or 2, characterized in that a rotatable drive shaft (86) in the aeftaren dressing component (2o) stored and with the slide (44) is connected so that it moves with the carriage when it rotates, and that the drive shaft (86) with the drive part (72) is connected so that the initial rotation of this drive part (72) by one H predetermined The extent to which the rotation is transmitted to the drive shaft (86) located in this rotatable dressing component (2o) and moves the carriage (44) located in this component (2o); and that a harvest stop device (Io2) the Sliding movement of the carriage (44) in this rotatable component (2o) ends before the drive part (72) moves by this predetermined amount Has rotated to the extent, wherein the continued rotation of the drive shaft (86) causes the rotatable Component (2o) begins to rotate. 4. Apparatus according to claim 3, characterized in that second stops (98, loo) are present, which end the sliding movement of the carriage (44) before the drive part (72) moves to the predetermined extent in the opposite direction turned nat, where üurcü die continued rotation of this drive part (72) of rotatable component (2o) returned to its starting position 6AD ORIGINAL 8QS8U6 / Q2A7 -'22 - - 5. The device according to claim 4, characterized in that the first stop (Io2) is adjustable to to determine the relative extent of movement of the dressing components. 6. Apparatus according to claim 4 or 5, characterized characterized in that the first stop (Io2) and the second Ansihlag (98, loo) consist of two stops that can be divided into one, which are arranged in the rotatable component (2o), and that the settings change the path of the breaking tool, to aas ratio ■ or the position of the straight track section to change to the arched section of the railway. 7. Device according to one of claims 1 to 6, characterized in that the rotatable component a bracket (2o) is made in the abzichtschlitten (12) -. -Orders, and that the driving component (72) in this Slide (12) is mounted and about the "axis of rotation of the The bracket (2o) rotates. 8o. Device according to claim 7 _S .dadurch in that a ochleppdichtun £ (92) .is in vorgeseneri ochlitten (12) and the BiI ^ el (2o) anliegtj mbe! this dragging seal: ^ 1 ^ 2) the ^ ewegun ^ aes bracket ί.2ο) delayed and atirlct, as the Öchlitten (44) is more freely movable than the bracket (2o). 9. The device according to claim '{ or 8, characterized in that in the carriage (12) an adjustable stop (.122) is present, which is ah the üü _c ; eT (2o). BAD ORIGINAL } ^ Ll 8 09808/024? sets to the starting position for the dressing tool (42) determine. Io. Device according to one of Claims 3 to 9, characterized in that the drive shaft (86) is arranged parallel to the axis of rotation of the bracket (2o) and at a distance therefrom is ; that outside of the bracket (2o) on the drive shaft (86) a gear (84) is attached, which of the Drive component (72) is driven, and that a gear (88) is attached to the drive shaft (86) in the bracket, which is in engagement with a rack (9o) on the be slide (44) is attached "to the drive ^ egung on the Transfer slide (44). 8Q9808 / 0247