JPS6137041B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a chuck having a radially adjustable pawl within the chuck body, the pawl being in axial contact with an axially forward pawl portion transversely to the chuck axis. and a rear pawl portion, each of which is radially adjustable and guided within the chuck body;
Only the rear pawl part engages with a drive member for driving the pawl, and the rear pawl part is provided with a coupling slide that can be connected and disconnected and is guided parallel to the chuck axis. When the connected slider is connected, both claws are
associated for radial entrainment of the front pawl portion by the rear pawl portion, and in the cutting condition releases the front pawl portion for radial adjustment independent of the rear pawl portion; and the coupling slider is forcibly guided by an externally operable adjustment member for adjustment between the two coupling states;
The adjusting element itself is of the type that is guided approximately radially adjustable in a rear pawl part and has a guide surface for forced axial guidance of the coupling slide.

The advantage of this type of chuck is that, by simply adjusting the coupling slider, both pawl parts can be connected to each other for the tightening process, or the front pawl part can be replaced or Alternatively, it is possible to separate the two pawl parts from each other when adjusting them relative to the rear pawl part in order to change the clamping diameter. If both pawl parts are separated from each other and the front pawl part is adjusted or replaced, the rear pawl part
It does not change its position within the chuck body and, in particular, remains engaged with the drive member which produces the radial pawl adjustment. This engagement therefore generally does not need to be released for changing the pawl or changing the clamping diameter. Since the engagement of the drive member with the rear pawl part is always maintained and the front pawl part can nevertheless be replaced, an additional adjustment distance is provided for the drive member to enable release of the pawl. There is no need to keep it. In already proposed chucks of the type mentioned above,
It is possible to lock the clamping movement of the drive member if the coupling slide is not in the fully connected state and thus prevent starting of the lathe.
For this purpose, the chuck body has a stop surface on the rear end face of the slider on the side of the rear pawl part opposite to the front pawl part, which stop surface fixes the slider in the connected state. . The chuck main body has a notch on this stopper surface, and when the rear pawl portion occupies the appropriate position, the connecting slider projects into the notch in the axial direction and engages in the radial direction, completely stopping the chuck. It can be adjusted to a disconnected state. Since the rear pawl part is locked against radial adjusting movements via the slider projecting into the recess, the drive element that engages with the rear pawl part no longer allows any axial tightening adjustment. can't do it. This locking of the drive member itself prevents starting of the lathe. because,
This is because the rotary drive of the lathe is not released by the distance control device which is normally provided for safety reasons for the movement of the drive member. Furthermore, in this chuck the adjusting member is a pin which can be pushed in radially towards the chuck axis against the force of a spring, which is provided with a window in the coupling slider and allowing its adjusting movement. It penetrates through
In the region of the window, it also has a guide surface for adjusting the coupling slide, for which purpose the coupling slide rests on the guide surface with a corresponding guide projection.

Furthermore, a power-operated chuck having a radially adjustable pawl within the chuck body is known, for example from US Pat. No. 2,729,459, in which approximately A radially adjustable centrifugal weight is provided which operates a lever that acts on the pawl against centrifugal force, the lever acting on a tangent to a circle about the axis of rotation of the chuck body. They are pivotable about an axis located in the direction and each carry one centrifugal weight. In this case, the centrifugal weight is located inside or outside the chuck body or flange. The flange is fixed on the rear side of the chuck body coaxially with respect to the axis of rotation and serves to connect the chuck body to the lathe spindle. In particular, the centrifugal weight is freely adjustable guided in a radial guide groove of the chuck body or flange by means of a guiding addition and is pivotally connected to the lever end holding it. be able to. For this purpose, the lever end can be designed as a coupling ball that engages in a recess in the guide extension. This lever is mounted with a fixed pivot axis in the chuck body.

Such centrifugal force compensation means cannot be readily applied to chucks of the first mentioned type.
This is because the connection to the rear pawl part of the lever, which is operated by a centrifugal weight and acts on the pawl against centrifugal force, is due to the arrangement of the connecting slider in the rear pawl part and the adjustment of the connecting slider. Due to the provision of the adjustment element, it is difficult for reasons of space, and it is also difficult to create a connected state in which the coupling slider is connected parallel to the chuck axis, ie practically in the longitudinal direction of the lever. This is because it is initially unthinkable to use the coupling slider itself for this connection of the lever, since it has to be adjusted between the disconnected and disconnected states.

The object of the invention is to provide a chuck of the type mentioned at the outset, in a structurally simple and operationally reliable manner.
A device is provided to compensate for the centrifugal force acting on the pawl.

In order to achieve this objective, the configuration of the present invention includes:
A substantially radially adjustable lever is disposed on the chuck, and a lever is pivotably supported between the centrifugal weight and the pawl, one end of which is loaded by the centrifugal weight, and the other end of which is loaded with the centrifugal weight. When the force is applied to the pawl in the opposite direction, the end of the lever on the pawl side (the other end) pivots in a receptacle formed in the axial rear end of the coupling slider. connected to the coupling slider in such a way that the lever is carried along by the coupling slider during an adjustment movement between the two coupled states; For this purpose, the lever is movable in the chuck body at its fulcrum and at its connection to the centrifugal weight in the longitudinal direction of the lever by the axial adjustment distance of the coupling slide.

The advantage achieved by the invention is that, in the chuck according to the invention, a swiveling motion with centrifugal force compensation is provided, despite the fact that the connecting slide is guided in the rear pawl part and that an adjustment element is provided. The connection to the rear pawl part of the lever is made in a very advantageous manner in terms of loading, i.e. directly on the coupling slider itself, so that the chuck body is not fixed in the pivot axis of the lever, but is movable parallel to the chuck axis. The lever is located within the coupling slider, so that the lever participates in the connecting and severing movements of the coupling slider without interfering with these movements. Also in the configuration of the present invention, for safety reasons the adjustment of the coupling slider to the disconnected state allows the end of the slider to protrude into the notch in the chuck body described above that locks the radial pawl adjustment. This can only be possible by doing so.

In one advantageous embodiment, the lever end on the pawl side is a spherical bearing head which engages in a receptacle in the end of the connecting slide, and which is provided with a tangential direction of a circle about the chuck axis. It is held within the receptacle by a joint having a pivot axis extending in the receptacle. This coupling ensures the driving of the lever by the coupling slider during axial adjustment between the connected and the shrunken coupling state. The spherical thickening of the bearing head compared to the lever shaft not only creates favorable conditions for the transmission of radial forces from the lever end to the coupling slider, but also , the diameter of the connecting slider and the diameter of the notch in the chuck body that accommodates the slider in the shrunk connected state are selected so that the pivoting movement of the lever shaft passing through this notch is controlled by the rear pawl portion. This makes it possible in a particularly simple manner to ensure that the radial tightening stroke is not disturbed by the walls of the recess. In order to form the pivot axis of the coupling, the bearing head has a transverse passage coaxial therethrough with the pivot axis of the coupling and, facing the opening of this transverse passage, extends from the wall of the receptacle. Advantageously, a recess is formed in the lateral channel, in which the ball held in the transverse channel engages. In order to keep the balls in this engaged state, a longitudinal passage is opened in the transverse passage and approximately perpendicular thereto, into which a rod is pushed up to the transverse passage; can push the rows of balls in the transverse channel outwards, so that in each case the outer balls are pushed into their respective notches.

The lever support in the chuck body, which allows longitudinal movement of the lever, can be constructed particularly simply in the following manner. That is, the lever rests in the lever pivoting direction with a spherical bearing part on a ring-shaped bearing surface of the chuck body, which bearing surface extends axially over the adjustment distance of the coupling slider, and which The bearing part is movable along the support surface parallel to the chuck axis. Furthermore, in order to make a longitudinal movement of the lever particularly easily possible also at its connection in the centrifugal weight, it is provided that the centrifugal weight is radially displaceably guided and for the lever end loaded thereby. Each has a receptor part of
The receiving part has a substantially cylindrical section extending parallel to the chuck axis, in which the lever engages with a substantially spherical bearing head, which supports the receiving part. The receptacle may be in contact with a wall of the receptacle and may be axially movable in the receptacle by at least the adjustment distance of the coupling slide.

Furthermore, the adjusting element passes through a window provided in the coupling slider and allowing an adjusting movement of the slider, and has a guide surface in the area of the window, the coupling slider being able to move through the guide surface via the guide projection. In one advantageous embodiment of the invention, the guide projection for adjusting the coupling slider in the fractured coupling state is provided by a projection on the end of the lever on the pawl side. The projection projects into the window of the coupling slider through a receptacle for the lever end. In other words, the coupling slider can be adjusted by means of this projection and the lever connected to it by the adjusting member into the severed coupling state, that is, towards the rear in the axial direction, in which case this adjusting movement Therefore, it is not necessary to provide a specific guide projection on the coupling slide itself. Overall, this results in an extremely simple design and assembly of the connection between the lever and the coupling slide.

In the following, the configuration of the present invention will be specifically explained with reference to embodiments shown in the drawings.

In the drawings, the chuck body is generally designated 1 and the pawls radially adjustable guided therein are generally designated 2. A radial guide groove, generally designated 3, is provided in the chuck body for guiding the pawl. In the axial section of FIG. 1 only one pawl is shown. However, such a chuck has more than just one pawl, generally three pawls 2. Claw 2
for its radial adjustment is in operative engagement with a drive member 4, which in the illustrated embodiment has an axially adjustable drive sleeve 5, which drive sleeve 5 is wedge hook 6,
It engages with the pawl 2 via 7. In this case, a wedge hook 6 is provided on the drive sleeve 5 and a wedge hook 7 is provided on the pawl 2.

When the drive sleeve 5 is moved towards the left in FIG. 1, the pawls are moved radially inwardly, whereas the drive sleeve 5 is adjusted axially in the opposite direction. The pawls are moved radially outward. The drive sleeve 5 is actuated in the usual manner by a clamping cylinder, not shown, whose clamping piston is connected to the drive sleeve 5 via a draw rod or a draw tube through a hollow lathe main shaft, also not shown. be able to. Moreover, such a power tightening cylinder can also be arranged directly in the chuck body 1. In place of the wedge hooks 6, 7 provided in the illustrated embodiment, it is also possible to use known coupling members for mediating the drive of the pawl 2 by the drive member 4.

The pawl 2 extends radially and transversely to the chuck axis 9, in the exemplary embodiment in a plane perpendicular to the chuck axis 9, with an axially forward pawl portion 2a.
and a rear pawl portion 2b in the axial direction. The two pawl parts 2a, 2b are each radially adjustable guided in a guide groove of the chuck body 1, i.e. the front pawl part 2a is guided with a guide groove 10 into the guide strip 11 of the chuck body 1.
The rear cylindrical pawl portion 2b is guided along the cylindrical guide groove 12 of the chuck body 1.
Guided inside. Both claw parts 2a, 2b
Of these, only the rear pawl portion 2b is connected to the drive member 4,
In the exemplary embodiment, it therefore engages with the wedge hook 6 of the drive sleeve 5. is movably guided in the rear pawl portion 2b parallel to the chuck axis 9;
The connecting and severable connecting piece, which is configured as a connecting slide 8 of approximately circular cross section and which is held rigidly, in other words non-adjustably, in the pawl part 2b in the radial direction, can be connected as shown. serves to rigidly connect both pawl parts 2a, 2b in the connected state for radial entrainment of the front pawl part 2a by the rear pawl part 2b;
On the other hand, when the coupling slider 8 is in a retracted position in the axial direction (not shown), that is, in the severed coupling state, the front pawl portion 2
a is released for an independent radial adjustment with respect to the rear pawl part 2b, so that the front pawl part 2a is completely removed from the radial guide groove 3 and replaced by another pawl part. be able to. On the other hand, the rear pawl portion 2b is not replaceable and is always engaged with the drive member 4.

The coupling slide 8 has a coupling head 17 which, when the coupling slide 8 is advanced as shown, radially locks into the coupling receptacle 18 of the front pawl part 2a. operatively engaged. The connection receiving portion 18 is connected to the front pawl portion 2 facing the rear pawl portion 2b.
It is formed by horizontal teeth provided on the dividing surface of a. The connecting head 17 is provided with corresponding teeth, which, as shown in FIG.
is engaged with the teeth of

For adjustment between the connected and disconnected connection states, the coupling slide 8 is forcibly guided by an externally operable adjustment member 13. The adjusting element 13 itself is guided in a substantially radially adjustable manner in the rear pawl part 2b and has inclined guide surfaces 13.1 and 13.2 for forced axial guidance of the coupling slide 8. ing. In detail, the adjusting member 13 is a cylindrical pin which can be pushed radially inwardly into the chuck axis 9 against the restoring force created by the spring 14, and which is inserted into the coupling slide 8. Through a window 15 which is provided and which allows an axial adjusting movement thereof, an inclined guide surface 1 is provided in the area of this window 15.
3.1 and 13.2.

The chuck body 1 has a stop surface 19 for the rear end face 20 of the coupling slide 8 on the side of the rear pawl part 2b opposite to the front pawl part 2a. This stop surface 19 locks the coupling slider 8 in the connected state. In this case, the connecting slide 8 does not face the cutout 21 formed in the stop surface 19. Rear claw part 2
When b is in the illustrated position, the connecting slider 8 can enter the notch 21 in the axial direction,
The coupling slider is thereby axially adjustable up to the severed coupling state. Therefore, when the coupling slider protrudes into the cutout 21, it locks the rear pawl portion 2b in the radial direction, and the drive member 4 is no longer subject to axial tightening adjustment. can't do it. Therefore, in the torn connection state, if the connection between the rear pawl portion 2b and the front pawl portion 2a is released by the coupling slider 8 at one pawl 2, the lathe will Unable to start.

The adjustment member 13 is shown in the unpressed position in the drawing. The adjustment member allows movement of the coupling slide 8 into the torn coupling state only when pushed in radially. spring 14
When the adjustment member 13 performs a return movement under the action of the return force generated by the connecting slider 8
are adjusted again into the connected state by means of the inclined guide surface 13.1. When not pressed in, the adjusting member 13 moves the coupling slider 8 in the connected state to the inclined guide surface 13.
1 and a radial stop surface 13.3. Therefore, when the adjustment member 13 is in this position, the connecting slide 8 cannot penetrate into the recess 21 of the chuck body 1. By adjusting the rear pawl portion 2b in the radial direction, the connecting slider 8
In order to push the adjustment member 1 into the notch 21,
I have to press 3.

In order to compensate for the centrifugal forces acting on the pawl parts 2a, 2b, the chuck is provided with approximately radially adjustable centrifugal weights 16, one centrifugal weight being provided for each pawl. , only one centrifugal weight 16 is shown in FIG. In the exemplary embodiment, this centrifugal weight 16 is guided so as to be radially movable in a groove 16a of a connecting flange 18a which connects the chuck body 1 to a main shaft (not shown) by means of a screw 22. A lever 23 is provided between the centrifugal weight 16 and the pawl 2, and this lever 23 is rotatably supported on a fulcrum 24 within the chuck body. The lever 23 has one end loaded by the centrifugal weight 16, and the other end pushing the pawl 2 in a direction opposite to the centrifugal force. For this purpose lever 2
3 is formed at the axial end of the coupling slide 8 so as to be pivotable at the lever end on the pawl side and with an engaging action in order to achieve a good force transmission at least radially inwardly. It is seated in a receiving part 25 that is located in the center. Furthermore, this lever end is connected to a coupling slide 8, such that the coupling slide 8 carries the lever 23 during adjustment movements between the two coupling states.

In order to make this longitudinal adjustment of the lever 23 possible, the lever 23 is moved by at least the axial adjustment distance of the coupling slide 8 onto the chuck body, at its fulcrum 24 on the chuck body 1 and at its connection to the centrifugal weight 16. It is possible. The lever end on the pawl side is designed as a spherical bearing head 23.1 and is thicker than the lever shaft 23.2. The recess 21, which receives the coupling slider 8 for locking the rear pawl part 2b, has a width equal to the diameter of the coupling slider 8, so that the pawl 2 performs a tightening stroke and the lever 23 moves accordingly. When pivoting, the wall 21.1 of the recess 21 does not prevent the pivoting movement of the lever 23. In order to achieve entrainment of the lever 23 during axial adjustment of the coupling slide 8, the bearing head 23.1 is coupled by a joint 26, which has a pivot axis tangential to a circle about the chuck axis. It is held within the receiving portion 25 of the slider 8. To form the pivot axis of the joint, the bearing head 23.1 has a transverse passage 23.3 coaxial therethrough with the pivot axis. The wall of the receptacle 25 has a recess 27 facing the transverse passage opening, which is also designed as a passage opening, in which the ball held in the transverse passage 23.3 is inserted. 23.4 is engaged. In order to ensure this engagement of the ball 23.4 into the cutout 27, a longitudinal channel 2 is inserted into the transverse channel 23.3.
3.5 is open, and in this vertical passage there is a horizontal passage 23.3 from the lever end on the centrifugal weight 16 side.
The rod 28 is pushed in until the end. This rod 28 pushes the rows of balls in the transverse channel outwards, so that in each case the outer balls are pushed into the associated recess 27.

In the direction of lever pivoting, the lever 23 rests with a spherical bearing part 23.6 on a ring-shaped bearing surface 29 of a bearing ring 30, which is inserted immovably in the chuck body 1. extends axially over the adjustment distance of the coupling slider 8;
Along this support surface the bearing part 23.6 is movable parallel to the chuck axis 9. If the bearing part 23.6 has a circular cross section, the bearing surface 29 will generally have the shape of a cylindrical surface. The movability of the lever 23 is controlled by the centrifugal weight 16.
In order to ensure that the centrifugal weights 16 also have one receptacle 16.1 in each case,
for the lever end loaded thereby. The receptacle 16.1 has an approximately cylindrical section extending parallel to the chuck axis 9, in which the lever 23 rests against the bearing head 23.1.
7, the bearing head being constructed as part of the ball. The bearing head 23.7 is in contact with the wall 16.3 of the receiving part 16.1 and extends at least by the adjustment distance of the coupling slide 8.
It is axially movable within 6.1. in this case,
In order to allow for the shortest possible dimensions in the axial direction, the bearing head 23.7 can be cut out to form a flat end face 16.2.

In order to be able to adjust the connection slide 8 into the torn connection state by pressing down on the adjustment member 13, the adjustment member 13 has, on the side facing the lever 23, an inclined guide surface 13. It has 2. The guide projection associated with this guide surface 13.2 is formed by a projection 31 of the lever end on the pawl side, which passes through a receptacle 25 for the lever end into the coupling slide 8. It has entered window 15. Therefore, when the adjusting member 13 is pushed down toward the window 14, the lever 2 is first moved via the guide surface 13.2 and the inclined surface 31.1 of the projection 31.
3 is pushed back in the axial direction, and this lever
3.4, the coupling slide 8 is moved through the joint connection formed by 3.4 and thereby adjusted to the severed coupling state. This is because the locking by the locking surface 33 is released. This means that the ramp 13.2 only engages the projection 31 of the lever 23 after the locking surface 33 has been moved out of the area of the stop surface 13.3. For this purpose, a corresponding dead distance 32 is provided between the projection 31 and the inclined surface 13.2.

[Brief explanation of the drawing]

FIG. 1 is an axial sectional view of a chuck according to the invention, and FIG. 2 is an enlarged sectional view taken along the line -- in FIG. 1...chuck body, 2...claw, 2a and 2b...
Pawl portion, 3...Guide groove, 4...Drive member, 5...Drive sleeve, 6 and 7...Wedge hook, 8...Connection slider, 9...Chuck axis, 10...Guide groove,
DESCRIPTION OF SYMBOLS 11...Guiding strip, 12...Guiding groove, 13...Adjusting member, 13.1 and 13.2...Guiding surface, 13.3...
Stopper surface, 14... Spring, 15... Window, 16... Centrifugal weight, 16.1... Receiving part, 16.2... End surface, 1
6.3... Wall surface, 16a... Groove, 17... Connection head, 18... Connection receiving part, 18a... Connection flange,
19...Stopper surface, 20...End face, 21...Notch, 21.1...Wall surface, 22...Screw, 23...Lever, 23.1...Support head, 23.2...Lever shaft, 23.3...Side passage, 23 .4...Ball, 2
3.5...Vertical passage, 23.6...Supporting part, 23.7
... bearing head, 24 ... fulcrum, 25 ... receiving part, 26
...Joint, 27...Notch, 28...Rod, 29...
Support surface, 30...Support ring, 31...Protrusion, 31.
1... Inclined surface, 32... Dead distance, 33... Locking surface.

Claims (1)

Claims: 1. A chuck having a radially adjustable pawl within the chuck body, the pawl having an axially forward pawl portion and an axially rearward pawl portion transversely to the chuck axis. It is divided into a claw part,
Both pawl parts are respectively radially adjustable guided in the chuck body, with only the rear pawl part engaging a drive member for driving the pawl; A connectable and disconnectable connecting slide is provided, which is guided parallel to the chuck axis and which in the connected state holds both pawl parts in a radius of the front pawl part by the rear pawl part. coupled for directional entrainment, and in the disengaged state releases the front pawl part for radial adjustment independent of the rear pawl part, and the coupling slider is connected in both coupled states. For the adjustment of the distance, the adjustment element is forcedly guided by an externally actuable adjusting element, which itself is guided approximately radially adjustable with a rear pawl, and the axial forced guidance of the coupling slider is A centrifugal weight 1 adjustable approximately in the radial direction in a type having a guide surface for
A lever 23 is rotatably supported between the centrifugal weight 16 and the pawl 2, and one end of the lever 23 is loaded by the centrifugal weight 16 and the other end is subjected to centrifugal force. acts on the pawl 2 in the opposite direction, the other end of the lever 23 being pivoted in a receptacle 25 formed in the axial rear end of the coupling slide 8 and at least radially The lever 23 engages inwardly in the receptacle and is connected to the coupling slide 8 in such a way that the lever 23 is carried by the coupling slide 8 during an adjustment movement between the two coupling states. chuck, characterized in that the lever 23 is movable in the chuck body 1 at its fulcrum 24 and at its connection to the centrifugal weight 16 in the longitudinal direction of the lever by the axial adjustment distance of the coupling slide 8. 2 Support head 2 with a spherical lever end on the pawl side
3.1 into a receptacle 25 at the end of the coupling slide 8, said bearing head 23.1 having a pivot axis extending tangentially to a circle about the chuck axis 9. Receptacle 25 by means of fitting 26
The chuck according to claim 1, which is maintained within the scope of claim 1. 3. To form the pivot axis of the joint, the bearing head 23.1 has a through-through transverse passage 23.3 coaxial with the pivot axis and facing the opening of this transverse passage. Claim 2, characterized in that a cutout 27 is formed in the wall of the receiving part 25, in which the ball 23.4 held in the transverse channel 23.3 engages. Check. 4 Opening into the transverse passage 23.3 is a longitudinal passage 23.5 approximately perpendicular to it, into which a rod 28 is pushed as far as the transverse passage 23.3; 4. A chuck as claimed in claim 3, characterized in that it pushes the rows of balls in the transverse passage outwards, thereby forcing the outermost balls in each case into the associated recesses (27). 5 The lever 23 rests in the lever pivoting direction with a spherical bearing part 23.6 on a ring-shaped support surface 29 of the chuck body 1, which supports the axis over the adjustment distance of the coupling slide 8. 2. A chuck as claimed in claim 1, in which the bearing part (23.6) extends in the direction along which the bearing part (23.6) is movable parallel to the chuck axis (9). 6 The centrifugal weights 16 are radially displaceably guided and each have a receptacle 16.1 for the lever end loaded thereby, which receptacle 16.1 is for the chuck. It has an approximately cylindrical section extending parallel to the axis 9, in which the lever 23 engages with an approximately spherical bearing head 23.7, which supports the receptacle. 16. The chuck according to claim 1, which is in contact with the wall surface 16.3 of 16.1 and is axially movable in the receptacle 16.1 by at least the adjustment distance of the coupling slide 8. 7. The adjusting member passes through a window provided in the connecting slider and allowing an adjusting movement of the slider, and has a guide surface in the area of the window, on which the connecting slider can be moved via the guide projection. A guide projection 31 at the end of the pawl side is in contact with the guide projection for adjusting the connection slider 8 to the disconnected state.
The projection 31 is formed by a connecting slide 8 through a receptacle 25 for the lever end.
A chuck according to claim 1 projecting into the window 15 of the claim 1.