JPS5826730Y2 - Retractable 2-jaw chuck - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a retractable two-jaw chuck that grasps irregularly shaped workpieces that cannot be grasped with a three-jaw chuck while attracting them to the front surface of the chuck.

A two-jaw chuck is used to grasp irregularly shaped workpieces, such as castings and forged products, whose surface shapes and dimensions are slightly different for each item, and whose shapes cannot be grasped with a three-jaw chuck. In some cases, if the chuck has two opposing gripping jaws that cannot rotate, the gripping surface of the gripping jaws will hit the workpiece unevenly and the workpiece cannot be grasped reliably. With a chuck that can rotate within a fixed angle, depending on the way the workpiece is held, the clamping force during gripping may cause the workpiece to shift, resulting in poor centering, and cutting resistance may also cause the workpiece to shift. In particular, in thin-walled products with a small curling allowance, defective products occurred due to this centering failure.

The present invention is designed to grasp irregularly shaped workpieces such as castings and forged products, whose surface shapes and dimensions vary slightly from piece to piece, by moving one grasping claw of a retractable two-jaw chuck within a certain angle. The rotation of the other grasping claw is restricted, and the workpiece is positioned by contacting the gripping surface of the grasping claw whose rotation is regulated. To provide a retractable two-jaw chuck which is configured to grasp movable grasping claws while following the movement, and can simultaneously center and grasp an object.

Hereinafter, the present invention will be explained in detail with reference to an embodiment shown in the drawings.

1, two inclined holes 2 with a circular cross section are penetrated from the front surface 1a toward the internal cavity 3 at positions that bisect the circumference of the chuck body with an appropriate radius around the center of rotation; Two pawl drive frames 6 and 6A each having a gripping pawl 4 attached to the front end and an inward engaging groove 5 cut out perpendicularly to the axial direction on the rear side are installed in each of the inclined holes 2. Further, one of the pawl drive frames 6A is fitted with a locking means such as a key 7 between the inclined hole 2 of the chuck body 1, and the grasping pawl at the front end of the frame 6A is fitted so as to be slidable in the axial direction. With 4, rotation is restricted.

Further, a rear plate 8 is fitted on the rear side of the chuck body 1,
The claw 1 drive rods 6 and 6 are inserted into the center hole 8a of the rear face plate 8.
A hollow pull rod 9 equipped with a flange portion 9a that engages with the engagement groove 5 of A is slidably inserted, and the pull rod 9
A freely slidable draw screw 10 inserted into the center hole 1b of the chuck body 1 is fitted into the hollow hole 9b, and the pull rod 9 is tightened to the freely slidable draw screw 10 by a round nut 11. .

Further, a claw drive frame 6 is provided on the circumference of the flange portion 9a of the pull rod 9.
and an outer periphery 9C and a side surface 9d that engage with the engagement groove 5 of 6A,
A retaining portion 9f is provided in which the retaining portion 9e is formed flat, and a gap 12 is formed between the outer periphery 9C and the engagement groove 5 of the pawl driving frame 6 to allow the pawl driving frame 6 to rotate within a certain angle. There is.

With the chuck of this embodiment configured as described above, for example, it is possible to handle irregularly shaped workpieces that cannot be grasped with a three-jaw chuck, such as the shape shown in FIG. When gripping workpieces that differ slightly from one item to another, the workpiece is positioned by contacting the gripping surface 4a of one of the gripping claws 4 whose rotation is restricted, and then the draw screw 10 and the pull rod 9 are When it is slid to the left from the position shown in Figure 1 by the operation of a rotating cylinder (not shown),
The pawl drive frames 6 and 6A engaged with the pull bar 9 move diagonally backward toward the center of the chuck, and accordingly, the grasping pawls 4 and 4 attached to the front ends also move in the same direction and rotate. The gripping surface 4 of one of the gripping claws 4 (the lower one in Fig. 2) whose movement is restricted
The other rotatable grasping claw 4 (the upper one in Fig. 2) follows and grasps the workpiece that has been positioned by contacting with a, so that the positioned workpiece does not shift when grasped. Ensures centering.

In this way, the present invention is a retractable two-jaw chuck, in which the rotation of one grasping claw is regulated and the other grasping claw is configured to be rotatable within a certain angle, so that irregularly shaped objects that cannot be grasped with a three-jaw chuck can be handled easily. Even if the workpiece is a workpiece whose surface shape and dimensions are slightly different for each workpiece, such as a cast or forged product, the workpiece can be held in contact with the gripping surface of one gripping claw that does not rotate the workpiece. By simply positioning, centering and grasping can be performed simultaneously, and the feature is that setup time can be reduced and the occurrence of defective products due to poor centering can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a retractable two-jaw chuck showing an embodiment of the present invention, and FIG. 2 is a front view showing the gripping chuck in a gripping state. 1... Chuck body, 2... Slanted hole,
3...vacant room, 4...grasping claw, 5...
...Engagement groove, 6,6A...Claw drive frame, 7...
...Key, 9...Pull bar, 12...
·gap.

Claims (1)

[Scope of utility model registration request] At the positions where the circumference of the chuck body is equally divided into two, inclined holes with a circular cross section are provided, penetrating from the front side of the chuck body to the internal cavity, and in these inclined holes, a grasping claw is attached to the front end, and a shaft is attached to the rear side. A claw drive frame with an inward engagement groove cut out perpendicularly to the direction is inserted into the jaw drive frame, and the flange of the pull rod inserted into the center of the chuck body is inserted into the engagement groove of the claw drive frame. The claw drive frame can be rotated within a certain angle between the engagement groove of one of the claw drive frames and the outer circumference of the engagement part of the flange of the pull bar by engaging the engagement parts provided on the outer periphery of each part. This retractable two-jaw chuck is provided with a gap between the other jaw drive frame and the chuck body, and a locking means such as a key for restricting the rotation of the jaw drive frame is interposed between the other jaw drive frame and the chuck body.