JP2703590B2 - Fastening tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a fastener called a chuck provided for holding a tool such as a drill bit and a driver bit in an electric drill, an electric screwdriver and the like.

[Prior art]

In a fastener that allows the tool to be attached and detached without using a chuck handle, in addition to a handle fixed to a shaft to which power is transmitted, a sleeve rotatable with respect to the shaft is provided, and this sleeve is rotated. In some cases, a plurality of claws for tightening are moved in the radial direction. By rotating the sleeve while grasping the handle, the tool can be clamped and held and removed. Here, this kind of fastener has a characteristic that when the work is performed by applying rotation to the shaft, relative rotation occurs between the shaft and the sleeve. For this reason, there is a possibility that the claws may spread due to this relative rotation and the tightening force may be loosened when performing the screw tightening operation or the punching operation,
With this, the work cannot be performed with confidence. However, if the direction of rotation of the sleeve that occurs at this time is set to be the direction of tightening the claw, rotating the shaft only in one direction does not cause any other problem, but electric With a tool like a screwdriver that allows the screw to be loosened by rotating the shaft in the reverse direction, the relative rotation that occurs between the shaft and the sleeve during this work causes the claws to spread and the tool It may come off during work. As a countermeasure for this, for example, JP-A-55-144910 and JP-B-57-43363 are provided with ratchet pawls and teeth which engage with each other between a sleeve and a shaft as locking means. It is shown. The engagement prevents the relative rotation between the shaft and the sleeve in the direction in which the claws are loosened.

[Problems to be solved by the invention]

In this case, not only must the ratchet pawls and teeth be provided, but also the number of parts and the number of assembling steps increase due to the mounting of the ratchet pawls. There was slight loosening because locking could only be performed at the engagement position between the teeth and the teeth. The present invention has been made in view of such a point, and an object of the present invention is to provide a fastener that can be manufactured at low cost with a small number of parts and that can be locked at an arbitrary position. is there.

[Means for Solving the Problems]

Thus, the fastening device according to the present invention includes a shaft to which power is transmitted, a sleeve rotatable with respect to the shaft, and a fastening claw that moves radially with rotation of the sleeve with respect to the shaft. A locking means for locking the rotation of the sleeve with respect to the shaft, and a releasing means for releasing the lock, wherein the locking means is wound around the outer periphery of the shaft and has one end locked to the sleeve, and A coil spring whose end is linked to unlocking means capable of rotating with respect to the sleeve and whose diameter is changed by rotation of the unlocking means with respect to the sleeve, wherein the unlocking means is provided over the outer periphery of the sleeve and is attached to the sleeve. With the required play in the direction of rotation It is rotatable with respect to rotation, and is characterized in that it is a rotating ring that changes the diameter of the coil spring by rotation within the limited range, and the locking means is wound around the outer periphery of the shaft and one end is attached to the sleeve. A coil spring that locks and has the other end linked to unlocking means capable of axial movement with respect to the sleeve and changes the diameter by movement of the unlocking means with respect to the sleeve. A rotating ring that is provided so as to cover and is integrally connected to the sleeve in the rotational direction and slidable in the axial direction with respect to the sleeve, and changes the diameter of the coil spring by the sliding movement. Has features. [Operation] According to the present invention, the rotation of the sleeve with respect to the shaft is locked, that is, the sleeve is prevented from being loosened by winding the shaft with the coil spring having one end locked to the sleeve. In addition, the unlocking and the removal of the bit need only be performed by grasping the rotating ring and operating the rotating ring. [Embodiment] Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. A metal cylindrical shaft 1 whose rear end is connected to an output portion of a power tool by a collar 15 and a set screw 16 provided inside is described below. A flange 14 is formed at the front end, a female screw 13 is cut on the inner peripheral surface, and a cylindrical handle 3 is press-fitted and fixed at the rear end. Screwed. A sleeve 8 having a groove 80 formed on the outer peripheral surface and a screw 88 formed on the front end side is disposed on the outer periphery of the front portion of the shaft 1, and further, a torsion coil spring type is provided between the handle 3 and the sleeve 8. Are disposed. Each of the plurality of claws 5 for tightening a tool such as a drill bit and a driver bit has an inclined outer surface, and has an engagement piece 50 at a rear end.
The engaging piece 50 is engaged with an engaging groove provided in the float screw 6.
60 is engaged. Each of the claws 5 is accommodated in a slit 70 formed in a conical metal guide block 7, and a wing piece 51 is formed on a conical surface on the outer surface of the guide block 7.
Are engaged. In the figure, reference numeral 75 denotes a part of the guide block 7. The guide block 7 and the pawl 5 are accommodated in a tapered bush 4 connected to the front end of the sleeve 8 by a screw 88. The guide block 7 is also fixed to the taper bush 4 and the sleeve 8, and these rotate integrally. The operating ring 2 surrounding the outer periphery of the tapered bush 4 on the rear end side and the outer periphery of the sleeve 8 is provided with a projection 20 protruding from the inner peripheral surface thereof by a groove 80 formed on the outer peripheral surface of the sleeve 8.
Is engaged. However, since the width of the groove 80 is considerably larger than the width of the projection 20, there is play between the sleeve 8 and the operation ring 2 in the rotation direction. The operation ring 2 has a pressing projection 21 on the inner peripheral surface at the rear end. The coil spring 9 wound around the shaft 1
Is to reduce its diameter and exert a spring force in the direction of winding around the shaft 1. One end 91 is inserted into a hole provided in the sleeve 8 and locked, and the other end 91 is
Is held in contact with the side surface of the pressing projection 21 of the operation ring 2 by the spring elasticity of the coil spring 9 itself. Then, the rotation of the shaft 1 in the direction indicated by U in FIG. When the operation ring 2 is rotated in the direction indicated by T in FIG. 2 within the range of play with respect to the sleeve 8, the pressing projection 21 provided on the operation ring 2
The sleeve 8 rotates freely with respect to the shaft 1 in order to press the other end 92 of the shaft 1 and loosen the coil spring 9. In mounting the tool with the fastener, the rear end of the tool is inserted through the opening at the front end, and the electric tool is operated while holding the operation ring 2 to rotate the shaft 1 in the S direction in the drawing. At this time, the coil spring 9 whose one end is locked to the sleeve 8 which does not rotate together with the operation ring 2 is to be dragged by the rotation of the shaft 1 to expand its inner diameter. 1 rotates without being affected by the coil spring 9. At this time, since the operation ring 2 is grasped, the rotation of the taper bush 4 and the guide block 7 together with the sleeve 8 and the float screw 6 are also stopped. 6 moves forward and moves each claw 5 forward. As a result, the claws 5 that position the wing pieces 51 between the guide block 7 and the inner peripheral surface of the tapered bush 4 gather at the center in the radial direction and tighten the tool. When performing the work to loosen the screw,
It rotates in the direction indicated by U in the figure. in this case,
Since the coil spring 9 which is dragged by the rotation of the shaft 1 and is rotated around the shaft 1 is strongly wound around the shaft 1, the shaft 1 and the sleeve 8 are coupled via the coil spring 9. Relative rotation of the sleeve 8 is locked. Therefore, the pawl 5 does not spread due to the relative rotation of the operation ring 2 with respect to the shaft 1. Next, removal of the tool can be performed by rotating the shaft 1 in the direction shown by the arrow U while holding the operation ring 2. That is, when the operating ring 2 is gripped and the shaft 1 is rotated in the direction of the arrow U, the sleeve 8 also starts to rotate at the same time, but since the operating ring 2 has play with the sleeve 8 in the rotating direction, the sleeve 8 has a play. If 8 starts rotating, coil spring 9
8 and operating ring 2 with both ends locked
The coil spring 9 is loosened by the relative rotation between and the shaft 1 rotates thereafter. For this reason, the claws 5 are widened and the tightening of the tool is released. 4 and 5 show another embodiment. Here, the operating ring 2 does not have play in the rotation direction with respect to the sleeve 8, but the operating ring 2 can be freely slid in the axial direction with respect to the sleeve 8, and the pressing protrusion 21 provided on the inner surface of the operating ring 2 is provided. This is different from the above-described embodiment in that the other end 92 of the coil spring 9 engaging with the coil spring 9 is bent obliquely. In this case, when the operation ring 2 is positioned forward, only the base end of the bent other end 92 of the coil spring 9 abuts on the pressing projection 21, but the operation ring 2 is slid backward. When this is done, the pressing projection 21 also comes into contact with the distal end side of the other end 92 and moves it in the direction indicated by P in FIG. 5, that is, in the direction in which the coil spring 9 is loosened. , The lock between the sleeve 8 and the shaft 1 is released.

【The invention's effect】

As described above, in the present invention, the lock releasing means is wound around the outer periphery of the shaft, one end of which is engaged with the sleeve, and the other end is linked to the unlocking means capable of rotating or axially moving with respect to the sleeve. A coil spring that changes its diameter by movement with respect to the sleeve is used as locking means, and the rotation of the sleeve with respect to the shaft is locked by loosening the shaft by the coil spring, that is, the loosening is prevented. In addition to the reduced number of parts, it can be provided at low cost and can be locked at any position, so it can be locked without any slight loosening, and it is provided over the outer circumference of the sleeve. Limited with the required play in the rotational direction relative to the sleeve A rotation ring that is rotatable relative to the sleeve within the enclosure and changes the diameter of the coil spring by rotation within the limited range, or is provided so as to cover the outer periphery of the sleeve, and is united in the rotation direction with respect to the sleeve. Since the rotating ring that is connected and is slidable in the axial direction with respect to the sleeve and changes the diameter of the coil spring by the sliding movement is used as the unlocking means, the lock by the coil spring is released and the tool is removed. In order to release the lock and rotate the sleeve with respect to the shaft to release the tool, simply rotate the rotating ring or rotate the rotating ring while grasping the rotating ring. All you have to do is unlock Removal of Le is easy.

[Brief description of the drawings]

1 and 2 are longitudinal sectional views of one embodiment of the present invention and XX.
FIG. 3 is an exploded perspective view of the same, FIG. 4 and FIG.
The figure is a vertical sectional view and a sectional view taken along line YY of another embodiment,
Reference numeral 1 denotes a shaft, 2 denotes an operation ring, 5 denotes a pawl, 6 denotes a float screw, 8 denotes a sleeve, and 9 denotes a coil spring.

Claims (2)

(57) [Claims] 1. A shaft to which power is transmitted, a sleeve rotatable with respect to the shaft, a claw of a fastener for radially moving with rotation of the sleeve with respect to the shaft, and a sleeve with respect to the shaft. A fastening device comprising: a lock means for locking rotation; and a release means for releasing the lock, wherein the lock means is wound around the outer periphery of the shaft and has one end locked to the sleeve, and the other end rotated with respect to the sleeve. A coil spring, which is linked to the unlocking means that is enabled to change its diameter by rotation of the unlocking means with respect to the sleeve, wherein the unlocking means is provided over the outer periphery of the sleeve and is required in the rotation direction with respect to the sleeve. It is fixed with play and can rotate relative to the sleeve within a limited range. Tool clamping, characterized in that in rotation in the limited range is a rotating ring for changing the diameter of the coil spring. 2. A shaft to which power is transmitted, a sleeve rotatable with respect to the shaft, a tightening claw that moves radially with rotation of the sleeve with respect to the shaft, and a sleeve with respect to the shaft. A fastener comprising: a locking means for locking the rotation; and a releasing means for releasing the lock, wherein the locking means is wound around the outer periphery of the shaft, one end of which is locked to the sleeve, and the other end of which is a shaft with respect to the sleeve. A coil spring that is linked to the unlocking means that is movable in the direction and that changes its diameter by moving the unlocking means with respect to the sleeve; the unlocking means is provided to cover the outer periphery of the sleeve and rotates in the rotational direction with respect to the sleeve; And are slidable with respect to the sleeve in the axial direction, Fasteners, characterized in that the slide movement is a rotary ring for changing the diameter of the coil spring.