US2995958A - Rotatable tool-holder or work-holder for a machine-tool - Google Patents

Description

15, 1961 F. e. JUNGELING ETAL 2,995,958

ROTATABLE TOOL-HOLDER OR WORK-HOLDER FOR A.MACHINETO0L Filed July 20, 1959 2 Sheets-Sheet 1 I Nl EN TOR s FR/EDHELM 6. JUNGELI'NG CORNFLiS de 505 MARTINUS 7. SALTERS A 'is.

Aug. 15, 1961 F. e. JUNGELING ETAL 2,995,958

ROTATABLE TOOL-HOLDER 0R WORK-HOLDER FOR A MACHINETOOL Filed July 20, 1959 2 Sheets-Sheet 2 INVENTORS iEDHE 'LM e. JLNGELI'NQ 0 NE de 05R MART s a. SALTERS Un fi d ta s Pat n 2,995,958 ROTATABLE TOOL-HOLDER 0R WORK-HOLDER FOR A MACHINE-TOOL Friedhelm G. Jiingeling, Amsterdam, Cornelis de Boer,

Za'andam, and Martinus J. Salters, Amsterdam, Netherlands, assignors to Staatsbedrijf Artillerie-Inrichtingen, Zaandam, Netherlands Filed July 20, 1959, Ser. No. 828,407 3 Claims. (Cl. 74-813) The invention relates to a rotatable toolholder or work-holder for a machine-tool which is provided with a mechanism for immobilizing said holder in various positions.

The invention has for object to improve this type of holder in such manner that the stopping elements adjust themselves and may be reworked in a simple manner, so that differences in the pitch of said members on the holder can easily be corrected.

According to the invention an axially displaceable cylindrical stopping pin is supported in a stationary part of the frame in which the rotatable holder is supported. This holder is supported in such a manner that said pin can freely rotate through a restricted angular distance about its own axis. Abutment pins of circular section are mounted in the holder each in a more or less radial direction and each being freely rotatable in the holder through a restricted angular distance. The abutment pins are distributed over the circumference of the holder and are provided with an abutment face adapted to engage a corresponding abutment face on the stopping pin. With this arrangement the abutment pins and the stopping pin are freely rotatable they can adjust themselves, so that a plane of contact of the abutting faces of said pins in the adjusted position of the holder is obtained. The freely rotatable abutment pins may easily be removed from the holder for reworking their abutment faces for correcting the pitch of the pins. When correcting a pitch which is too small the abutment face of the pin concerned is to be ground off and when correcting a pitch which is too large it will be required to replace the pin by a pin still having on its abutment face an excess of material so that the face can be reworked exactly to the required size.

When wear on the abutment faces of the stopping pin and the abutment pins occurs or when clearance occurs in the bearing holes for said pins in the stationary frame or in the holder respectively, the abutment pins are to be replaced by new pins having an excess of material on their abutment face for further reworking said face in order to obtain the correct pitch of the pins.

According to the invention it is also possible to correct a difference in the pitch of the abutment pins without requiring replacing the pin or even the removal of an abutment pin for reworking its abutment face. To this end the abutment face of one or more of the abutment pins encloses an angle with the axis of the pin and said pin is mounted for axial adjustment in the holder. If the abutment pin is displaced outwardly or inwardly with respect to the holder, the inclined abutment face on said pin is also displaced, whereby a correction of a pitch difference is obtainable.

For rotating the holder it is required to move the stopping pin in the stationary part axially out of the path of the abutment pins, so that the holder then may be rotated through an angle somewhat larger than required and then may be rotated in the reverse direction after the stopping pin has been returned to its operating position. In the new adjusted position the abutment faces of the abutment pins and the stopping pin are again contacting. This rotation of the holder may be obtained by a ratchet gear, a worm drive, or the like.

The invention will be further described with reference to the accompanying drawing showing an embodiment of a hydraulically operated holder having five different positions of adjustment.

In the drawing:

FIG. 1 shows a longitudinal sectional view of the holder taken of line II on FIG. 2.

FIG. 2 is a cross-sectional view taken on line IIII of FIG. 1.

FIGS. 3 and 4 show two different positions of the ratchet gear for rotating the holder.

FIG. 5 is an enlarged cross-section of part of the holder, having an axially adjustable abutment pin and FIG. 6 is a sectional view taken on line VI-VI of FIG. 5.

The disk-shaped holder 1 is secured on a shaft 2 which, by means of bearings 3 and 4, is rotatably supported in a casing 5. Secured to shaft 2 is a friction disk 6 for braking the rotation of the holder 1 on the disk 7 which is secured against rotation to the casing 5. This disk is urged against the friction disk 6 by means of studs 9 loaded by a spring 8 so that the disk 6 exerts a constant drag on holder 1. By varying the tension of the springs 8 the friction encountered by the friction disk 6 on the disk 7 may be varied.

A cylindrical, axially displaceable stopping pin 10 is supported freely rotatable in the casing 5, and by means of a hydraulic cylinder 11 said pin may be moved out of its position of operation and returned into said position.

Five abutment pins 12 are supported freely rotatable in the holder 1 and each of said pins is provided with a flat abutment face 13 adapted to bear against a corresponding flat abutment face 14 on the stopping pin 10. The rotation of both the abutment pin 10 and the abutment pins 12 is restricted to a small angular displacement by a locking element.

The abutment pins 12 preferably are not directed radial- 1y so that the pins provide a larger bearing surface in the body of the holder with the result of less danger of the pins bending and flexing.

The casing is provided with an aperture 15 closed by a cover plate 16. As said plate can be removed the abutment pins 12 may readily be removed for regrinding the abutment face 13 if required, in mounted position of the holder.

A disk 18 is mounted on the hub 17 of the holder 1 for free rotation thereon and said disk on part of its circumference is provided with teeth 19 meshing with a rack 20 also constituting the piston rod of a hydraulic cylinder 21 and serving to rotate the holder 1 through the intermediary of a panel mechanism now to be described. A bolt 22 is rotatably supported in the disk 18 and on said bolt a double pawl 23 is secured. As the bolt 22 extends in an oblong hole 24 of the pawl 23 said pawl is adapted to slide with respect to disk 18. A roller 26 presses on the point 25 of pawl 23 and is supported on' balls in a cylindrical body 27 loaded by a spring 28 for urging the roller 26 on the point of pawl 23. Said pawl with its hole 24 is locked in either of its extreme posi-f tions with respect to the disk 18 by a ball 29 urged against the bolt 22 by a spring 30. Pawl 23 cooperates with teeth 31 provided on the hub 17 of the holder 1.

The device described above operates as follows:

FIG. 2 shows the device in its initial position, in which the abutment pin 12 is pressed against the stopping pin 10 under the influence of the pressure reigning in the cylinder 21. This pressure is transmitted to the holder by the arm 23a of pawl 23 engaging the notch 32 between the ratchet teeth 31. In FIG. 2 the pawl 23 is shown in its position in the end of the hole 24 and locked by the pressure of the roller 26 exerted on the point 25 f l I i 2,996,958

of the pawl and by the pressure of ball 29. As the point 25 of the pawl, the center of the cross section of the bolt 22 and the center of the teeth 31 are not lying on a straight line the pawl arm 23a is urged into the notch 32. Thus the accurately ground abutment faces 13 and 14 of the abutment pin 12 and the stopping pin are forced together by a constant pressure.

For rotating the holder to its following position the hydraulic cylinder 21 is set into operation so that the rack is moved to the left, whereby the disk 18 carrying the pawl 23 is rotated in clockwise direction. Thereby the pawl arm 23a is forced out of the notch 32 between the ratchet teeth 31 by means of its inner face and the pawl arm 2312 under the influence of the pressure roller 26 will be urged into the notch 34 between the ratchet teeth 31 as shown in dotted lines in FIG. 2.

The holder 1 continues to rotate until it has moved through an angular distance somewhat exceeding one fifthof its circumference and the following abutment pin 12a has passed the stopping pin 10, which latter in the meantime has been returned to its inoperative position by cylinder 11. Moreover pawl 23 with its oblong hole 24 is moved on bolt 22 to the full line position shown in FIG. 3, in which the point 25 of the pawl, the center of bolt 22 and the center of the ratchet teeth 3-1 are not lying on a straight line, so that the pawl arm 23b is urged into the notch 34 between teeth 31. Since the abutment pin 12a has now passed the stopping pin 10 by a slight amount the pin 10 may now be returned to its operative position by cylinder 11. The pawl 23 and the ratchet teeth 31 are now in the full line position shown in FIG. 3.

Thereupon the rack 20 is again moved to the right toward its retracted position as seen in FIG. 2 by cylinder 21, whereby the disk 18 with the pawl 23 is rotated in counter-clockwise direction and the pawl arm 23b is moved in the notch 34 between the ratchet teeth 31 until the sloping face 35 on the pawl arm 23b contacts the adjacent ratchet tooth 31. Under the influence of said sloping face 35 the pawl arm 2312 will then be lifted out of the notch 34 again and the pawl arm 23a with its face 33 will fall down on the preceding ratchet tooth 31 as shown in dotted lines in FIG. 3. The rotation of the disk 18 together With the pawl 23 is continued, whereby the pawl arm 23a falls into the notch 36 between the ratchet teeth 31 as shown in FIG. 4.

If rotation of disk 18 continues, pawl 23 with its oblong hole 24 moves on bolt 22 and the holder with its abutment pin 12 is moved back through the slight angular distance by which the pin 12 has passed its intended position until the pin contacts the stopping pin 10, so that the position shown in FIG. 2 is reached in which the holder 1 has been moved angularly exactly 72 degrees corresponding to one fifth of its circumference and the rack 20 has reached its original retracted position.

As with said reversed rotation of the holder each abutment pin 12 is moved slowly through a slight angular distance for engaging the stopping pin 10, injurious impact strain on the pins 10 and 12 is prevented so that a smooth running of the holder without wear of said pins is provided.

As shown in FIG. 5 the abutment face 13 of pin 12 encloses an angle With the axis of said pin. The rotation of the abutment pin 12 in the holder is restricted by a 4 screw '37 engaging a recess 38 at the circumference of the pin.

The abutment pin 12 has an axial bore 39 in which a bolt 40 extends having screw threads at its inner end 41 by means of which it is screwed in the holder 1 and secured against displacement by a locking screw 42.

The abutment pin 12 is secured against axial displacement on the bolt 40 between a collar 43 and a ring 44. By inserting a screw driver through the aperture 15 in the stationary frame 5 and after the locking screw 42 has been loosened bolt 40 together with pin 12 may be screwed inwards or outwards with respect to the holder, whereby the abutment face 13 is displaced and will increase or decrease the angular displacement of the holder. In this Way differences in the pitch of the abutment pins may be corrected.

The device may be operated in such a manner that first the bearing pressure between the pins 10 and 12 is relieved before returning the stopping pin 10 to its inoperative position for a next rotation of the holder, so that thereby also Wear on the abutment faces of the pins is avoided.

Instead of hydraulically the device described above may also be operated pneumatically or mechanically.

What we claim is:

1. In a device comprising a rotatable part to be immobilized in at least one position with respect to a stationary part, the combination of a pin-like stopping member mounted in said stationary part displaceable between an extended and a retracted position and freely rotatable through a limited angle about its axis, said stopping member having an abutment face at a side thereof, at least one pin-like abutment member mounted in said rotatable part freely rotatable through a limited angle about its axis and having an abutment face at a side thereof, said stopping member and said abutment member being disposed to be engageable with each other along their abutment faces in the extended position of said stopping member, the projection of the axis of said stopping member along a plane coincident with a radius of said rotatable part intersecting the axis of said abutment member in the abutting position of said members, and means for maintaining the abutting relation of the abutment faces of said members during immobilization of the rotatable part.

2. A device as claimed in claim 1, wherein said abutment face of said abutment member is disposed at an angle with the axis of said member, said member being axially adjustably mounted in said rotatable part.

3. A device as defined in claim 2, wherein said abutment member is provided with a bore, a bolt member extending through said bore and supporting said abutment member so as to prevent it from axial displacement, said bolt member being threaded in said rotatable part for axial adjustment of said abutment member upon rotation of said bolt member.

References Cited in the file of this patent UNITED STATES PATENTS 635,853 Henn Oct. 31, 1899 1,511,447 Drissner Oct. 14, 1924 1,578,232 Ferris Mar. 23, 1926 2,531,198 Bruet et al Nov. 21, 1950

Images