JPH0460761B2 - - Google Patents

Description

[Detailed description of the invention] 【Technical field】

The present invention relates to a fastening tool called a chuck, which is provided for holding tools such as drill bits and driver bits in electric drills, electric screwdrivers, and the like.

[Background technology]

A tightening device that allows tools to be attached and detached without using the chuck handle.
Some devices are equipped with a rotating ring that can rotate freely relative to the shaft through which power is transmitted, and by rotating this rotating ring relative to the shaft, multiple tightening pawls can be moved in the radial direction. .
That is, by rotating the rotary ring relative to the shaft, the tool can be tightened and held and removed. By the way, this type of tightening tool has a characteristic that when the shaft is rotated to perform work, relative rotation occurs between the shaft and the rotating ring. For this reason, when tightening screws or drilling holes, there is a risk that the claws will spread out due to this relative rotation and the tightening force will loosen. I can't do it with care. However, if the direction of rotation of the rotating ring that occurs at this time is set so that it is the direction that tightens the pawl, there will be no particular problem with a shaft that rotates only in one direction. In devices such as electric screwdrivers that allow you to loosen screws by rotating the shaft in the opposite direction, the relative rotation that occurs between the shaft and the rotating ring during this operation causes the claw to loosen. It may spread and the tool may come off during work. To this end, the present applicant proposed in Japanese Patent Application No. 61-10834 a locking means for locking the rotation of the rotary ring relative to the shaft to prevent loosening of the tightening of the tool by the claws during the work, and In order to attach and detach the tool, we have proposed a device in which the above-mentioned lock can be released by sliding the rotary ring in the axial direction. However, in the above device, a spring is provided that biases the rotating ring in the axial direction, and the rotating ring must be slid against this spring to release the lock. When attaching and detaching, the user had to rotate the rotating ring while sliding it against the spring, which was inconvenient to use. Of course, without the spring, this problem would not occur, but without the spring, the lock could be inadvertently released and the tool could come off.

[Purpose of the invention]

The present invention has been made in view of these points, and its purpose is to securely hold a tool by locking the rotating ring, and to
To provide a fastener that allows easy attachment and detachment of tools.

[Disclosure of the invention]

Therefore, the fastener according to the present invention includes a shaft to which power is transmitted, a rotating ring that is rotatable with respect to the shaft, and a tightening tool that moves in a radial direction as the rotating ring rotates with respect to the shaft. A groove is formed between the pawl, a rotary ring that is movable in the axial direction, and the shaft, and has a wedge-shaped cross section in a direction perpendicular to the axial direction and is inclined in the axial direction, and a groove disposed within the groove. a locking means which locks the rotary ring from rotating in one direction with respect to the shaft, locks the rotation of the rotary ring with respect to the shaft, and is unlocked by sliding the rotary ring in the axial direction; A rotary ring locking means for holding the rotary ring in the unlocked state and a spring for biasing the rotary ring toward the locked position, the rotary ring being in the unlocked state. can be maintained mechanically. The present invention will be described in detail below based on an illustrated embodiment. FIGS. 1 to 7 show one embodiment.
The metal cylindrical shaft 1, whose rear end is connected to the drive shaft 10, has a tapered surface 11 on its outer peripheral surface in the middle in the axial direction, the diameter of which decreases toward the rear, as shown in FIGS. 1 and 3. In addition, an irregularly shaped cross section 12 is provided at the rear end, and a female thread 13 with a reverse thread is cut into the inner circumferential surface of the front end.
A cylindrical handle 3 is press-fitted into the irregular cross section 12 of the shaft 1, and a float screw 6 is screwed into the female thread 13. The plurality of claws 5 that tighten the tool 4, which is a drill bit or a driver bit, all have sloped outer surfaces and have an engaging piece 50 at the rear end. It is engaged with an engagement groove 60 provided in the float screw 6. Also, each nail 5
is housed in a slit 70 formed in the conical metal guide block 7, and the blades 51 are engaged with the conical surface on the outer surface of the guide block 7. The rotating ring 2 has a cylindrical synthetic resin main body 20
and a metal locking fitting 23 which is also cylindrical and fixed within the rear part of the main body part 20,
The lock fitting 23 rotates together with the main body 20 by engaging a groove 24 formed on its outer circumferential surface with a protrusion 21 formed on the inner circumferential surface of the main body 20. Further, a taper bush 25 is connected to the front end of the main body portion 20.
The rotating ring 2 and the taper bush 25 are
A protrusion 22 formed on the inner circumferential surface of the main body 20
By engaging with a groove 26 formed at the rear end of the taper bushing 25, the rotary ring 2 is rotated as a unit, and the rotary ring 2 can freely move in the axial direction with respect to the taper bushing 25. The float screw 6, the guide block 7, and the plurality of pawls 5 are housed inside the taper bush 25 and the rotary ring 2, and between the inner surface of the rear end of the taper bush 25 and the outer surface of the shaft 1, A ring-shaped cap 16 and a washer 17 made of fluoroethylene resin are provided for axial engagement with the taper bushing 25, and a washer 17 made of fluoroethylene resin is provided. A projection 71 is provided on the guide block 7 which engages the groove 26. The guide block 7 and the float screw 6 are rotated together by a claw 5 that engages with both, and the float screw 6 is movable in the axial direction with respect to the guide block 7. Next is the locking means, which is the rotating ring 2.
A silent ratchet (freewheel) composed of a plurality of grooves 40 formed between the inner circumferential surface of the shaft 1 and the outer circumferential surface of the shaft 1, and a needle roller 9 disposed within each groove 40. It is formed with a one-way clutch. Each groove 40 is formed by a concave groove provided on the inner peripheral surface of the lock fitting 23 between the tapered surface 11 of the shaft 1 and the lock fitting 23 of the rotating ring 2, and is formed in the axial direction of the shaft 1. The cross-section in the direction perpendicular to is wedge-shaped. When the needle roller 9 bites into the groove 40, the rotating ring 2 is locked with respect to the shaft 1. Further, the groove 40 has an inclination along the tapered surface 11 of the shaft 1, and the rotary ring 2 is made slidable in the axial direction with respect to the shaft 1, so that the cross-sectional area of the groove 40 can be varied by this movement. By doing so, the above lock can be released. The rotating ring 2 is urged forward in the axial direction by a spring 30 disposed between the rotating ring 2 and the handle 3. The groove 40 is biased in a direction in which the cross-sectional area becomes smaller. Now, the above-mentioned handle 3 is made of synthetic resin, and its outer circumference is surrounded by a slit 32, and its inner circumference is fixed to the shaft 1 with a lock connected by a thin hinge part 33. Piece 3
1 is provided. This locking piece 31 is provided with a locking pawl 34 formed by an undercut on its edge on the side of the rotating ring 2, and a locking groove 27 formed in an annular shape extending over the entire circumference on the outer peripheral surface of the rotating ring 2.
It can be locked freely. However, when attaching the tool 4 to the lever fastener, insert the rear end of the tool 4 through the tip opening, and while grasping the handle 3, press the The rotary ring 2 may be rotated in the direction indicated by the arrow F in FIG. At this time, since the locking means holds the rotary ring 2 and the shaft 1 in a separated state, the rotation of the rotary ring 2 with respect to the shaft 1 is not hindered, and as the rotary ring 2 rotates, the taper bush 25, the guide block 7 and the float screw 6 are connected to the shaft 1.
The float screw 6, which is screwed into the shaft 1, moves forward to move each pawl 5 forward. As a result, the claws 5 that position the wing pieces 51 between the guide block 7 and the inner circumferential surface of the taper bush 25 converge to the center in the radial direction and tighten the tool 4. When tightening screws, etc., when the shaft 1 is rotated in the _T1 direction in Fig. 4, a relative rotation occurs in the rotating ring 2 in the direction of arrow F.
Although this is not the direction that locks the rotating ring 2 with respect to the shaft 1 as described above, the tool 4
The rotation is in the direction of tightening, which makes it even more desirable. When loosening screws, use shaft 1.
is rotated in the direction shown by arrow _T2 in FIG. In this case, the needle roller 9 in contact with the outer peripheral surface of the shaft 1 is moved in the direction of biting into the groove 40 having a wedge-shaped cross section, and as a result, the rotating ring 2 is locked with respect to the shaft 1. In other words, rotating ring 2 relative to shaft 1
This prevents the claws 5 from spreading out due to relative rotation. Next, the tool 4 is removed by rotating the rotary ring 2 with respect to the shaft 1 in the direction shown by arrow U in FIGS. 4 and 5 to spread the claws 5. Since the rotation of the rotary ring 2 with respect to the shaft 1 is locked by the rotation of the rotary ring 2, as shown in FIG. Let's do it. When the rotating ring 2 is moved backward against the spring 30, the groove 40
Since the cross-sectional area of the needle roller 9 becomes larger and the needle roller 9 is no longer in contact with both the shaft 1 and the rotating ring 2, the rotating ring 2 will not be locked. When the rotary ring 2 is moved toward the handle 3, the locking pawl 34 of the locking piece 31 on the handle 3 locks onto the hinge portion 33.
Due to the elasticity of the locking groove 27 of the rotating ring 2
Since the rotary ring 2 is locked against the handle 3, there is no need to manually hold the rotating ring 2 moved toward the handle 3 side against the spring 30, and once the state shown in FIG. The tool 4 can be removed by simply rotating the rotary ring 2 relative to the handle 3 in the same manner as when the tool 4 is attached. As shown in FIG. 7, if the locking pawl 34 is released from the rotating ring 2 by pushing the rear end of the locking piece 31 of the handle 3, the rotating ring 2 will return to its original state under the bias of the spring 30. return to the state. In the embodiment shown in FIGS. 8 and 9, the rotary ring 2 is attached to the taper bush 25, which is a member that rotates integrally with the rotary ring 2 and whose inner surface guides the radial movement of the tightening pawl 5 as described above. A groove 28 having a shorter length than the groove 26 is provided adjacent to the groove 26 provided at the rear end edge of the taper bush 25.
If the rotary ring 2 is rotated in the direction of loosening the tightening by the claws 5 while the rotary ring 2 is slid toward the handle 3 side, the protrusion 22 provided on the inner surface of the rotary ring 2 at the initial stage.
is moved from the groove 26 to the groove 28, thereby preventing the rotating ring 2 from returning in the axial direction. In order to release the engagement between the groove 28 and the protrusion 22, it is sufficient to turn the rotary ring 2 a little in the opposite direction, that is, in the direction that tightens the pawl 4. The protrusion 22 moves into the groove 26 and returns to its original state under the force of the spring 30. In the embodiment shown in FIG. 10 and below, a leaf spring 72 is provided on the inner surface of the guide block 7 in order to prevent the tool 4 from tilting when the tool 4 is attached to the first embodiment. It is something.
That is, three leaf springs 72 exhibiting elasticity in the radial direction are installed at equal intervals on the inner circumferential surface of the guide block 7 and in a portion located between the claws 5 in the circumferential direction, and when the claws 5 are spread. When the tool 4 is inserted, the tool 4 is temporarily held by these leaf springs 72 without tilting, and even when installing a small diameter tool 4, the tool 4 is temporarily held coaxially with the fastener. Tool 4 to be
There is no need to worry about the inclination of the tool 4 when tightening it.

【Effect of the invention】

As described above, since the present invention includes the rotary ring locking means for holding the rotary ring in the unlocked state, the rotary ring is rotated relative to the shaft in the unlocked state to attach and detach the tool. During this process, the unlocked state is mechanically maintained, and for this reason, the only operation required to actually attach and detach the tool is to turn the rotating ring relative to the shaft, making it easy to attach and detach the tool. be. In addition, the operation for opening and closing the claws only requires rotating the rotary ring, and there is no need to operate other members or change hands during operation, and the operation is easy. Since the locking means for locking the rotary ring locks the rotation of the rotary ring in only one direction, it is only necessary to slide and rotate the rotary ring when rotating in one direction.
Furthermore, the rotating ring is biased to the locked position by a spring, so after sliding the rotating ring to release the lock and opening or closing the claw, the rotating ring will automatically lock due to the spring. Even if the screws are tightened or loosened with the lock released by mistake in order to return to the position,
There is no chance of the nails coming loose during work.

[Brief explanation of the drawing]

FIG. 1 is a cutaway front view of one embodiment of the present invention, and FIG.
The figure is a front view of the same as above, Figure 3 is an exploded perspective view of the same as above,
Figure 4 is a cross-sectional view taken along the line A-A in Figure 1, Figure 5 is a cross-sectional view showing the locked state, Figure 6 is a longitudinal cross-sectional view showing the unlocked state, and Figure 7 is a cross-sectional view of the rotating ring. 8 is an exploded perspective view of another embodiment; FIG. 9 is a plan view of the same taper bushing; FIG. 10 is an exploded perspective view of another embodiment;
FIG. 11 is a longitudinal cross-sectional view of the same as above, FIG. 12 is a cross-sectional view of the same as above, FIG. 1 is the shaft, 2 is the rotating ring, 3 is the handle, 4 is the tool, 5 is the claw, 27
indicates a locking groove, and 31 indicates a locking piece.

Claims (1)

[Scope of Claims] 1. A shaft to which power is transmitted, a rotary ring rotatable with respect to the shaft, and a tightening pawl that moves in a radial direction as the rotary ring rotates with respect to the shaft; A groove is formed between a rotary ring that is movable in the axial direction and the shaft, and has a wedge-shaped cross section in a direction perpendicular to the axial direction and is inclined in the axial direction, and a groove disposed within the groove. and a rolling member that locks the rotating ring from rotating in one direction relative to the shaft.
a locking means for locking rotation of the rotary ring relative to the shaft and unlocking by axial sliding of the rotary ring; A fastener comprising a spring biasing a rotating ring to a locked position. 2. The tightening tool according to claim 1, wherein the rotating ring locking means is formed on a handle fixed to the shaft. 3. The rotating ring locking means is formed in a tapered bush that rotates together with the rotating ring and whose inner surface is a tapered surface for radial movement of the pawl. Fasteners listed.