Electric driver

Abstract

To provide a small-sized electric driver facilitating attachment / detachment of a driver bit.SOLUTION: An electric driver 1 which includes a chuck 20 capable of attaching / detaching a driver bit 2 is so configured that the chuck is composed of a sleeve-shaped chuck 21 shaft which is rotated with drive of a motor and into which the driver bit can be inserted, an annular groove 22 disposed in the inner peripheral surface of the chuck shaft, and an annular coil spring 23 stored along the annular groove; the driver bit having an annular engagement groove on the outer peripheral surface is inserted into the chuck shaft; and the driver bit is held by engaging the coil spring with the engagement groove 2a of the driver bit. The electric driver allows the driver bit to be easily attached only by insertion into the chuck, and to be easily removed only by pulling out the driver bit from the chuck.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a handy-type electric driver, particularly an electric driver used in surgical operations.

Background Art

[0002] As an electric driver, for example, a medical electric driver, there is one shown in Patent Document 1. Many medical electric drivers employ any one of a one-touch sleeve, a drill chuck, and a keyless chuck as a chuck mechanism for attaching a driver bit. The one-touch sleeve is configured to fix the driver bit by pulling the lock ring forward, inserting the driver bit, and when the hand is released in this state, the lock ring returns to its original position by the force of a spring. The drill chuck is configured to tighten and fix the driver bit to the chuck using a dedicated chuck key. The keyless chuck is configured to open and close the chuck by rotating a cylindrical sleeve and attach the driver bit thereto.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since any of the above-mentioned medical electric drivers has a structurally complex chuck mechanism, the number of parts is large and it becomes large-sized, so it has been difficult to use in a narrow space such as a surgical operation. In addition, since the user has to manually operate the chuck when attaching and detaching the driver bit, the replacement work becomes troublesome in a medical field where the replacement frequency of the driver bit is high for hygiene management.

[0005] The present invention was created in view of the above problems, and an object thereof is to provide a power driver that is small and allows a driver bit to be easily attached and detached.

Means for Solving the Problems

[0006] In a power driver provided with a chuck capable of attaching and detaching a driver bit, the chuck includes a sleeve-shaped chuck shaft that rotates with the drive of a motor and through which the driver bit can be inserted, an annular groove provided on the inner peripheral surface of the chuck shaft, and an annular elastic member housed along this annular groove. When a driver bit having an annular engagement groove on its outer peripheral surface is inserted into the chuck shaft, the elastic member fits into the engagement groove of the driver bit, and the power driver is configured to hold the driver bit.

[0007] It is preferable that the elastic member of the chuck is configured by connecting coil springs in an annular shape.

[0008] It is preferable that the inner diameter side of the elastic member of the chuck is normally positioned inside the inner peripheral surface of the chuck shaft, and is pushed and expanded to a position outside the inner peripheral surface of the chuck shaft as the driver bit is inserted. When the engagement groove of the driver bit reaches the position of the elastic member, it returns to its normal position and fits with the engagement groove of the driver bit, thereby being configured to hold the driver bit.

[0009] It is preferable that the elastic member of the chuck is configured to elastically deform when the driver bit held by the chuck is pulled, and the engagement with the engagement groove of the driver bit is released, thereby removing the driver bit from the chuck.

[0010] It is preferable that the power driver is for medical use and is used in a surgical operation for screwing a medical screw into a fractured part.

Effects of the Invention

[0011] The electric driver of the present invention can be easily attached simply by inserting the driver bit into the chuck, and can be easily removed simply by pulling out the driver bit from the chuck. In addition, since the number of components constituting the chuck is small, it can be miniaturized.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, 1 is an electric driver. This electric driver 1 is composed of a main body portion 10, a chuck 20 disposed at its tip portion, and a driver bit 2 attached to this chuck 20.

[0014] The driver bit 2 has an annular engagement groove 2a on its outer peripheral surface, and is configured to fit with a chuck 20, the details of which will be described later.

[0015] A motor (not shown) driven by an external power source is built in the main body portion 10. This motor is configured to be driven when an operator operates a switch 11 provided on the main body 10, and a chuck shaft 21 of the chuck 20, the details of which will be described later, is connected to the output shaft of the motor via a speed reducer (not shown).

[0016] As shown in FIG. 2, the chuck 20 is composed of a bottomed sleeve-shaped chuck shaft 21 and an annular coil spring 23 housed in a fitting groove 22 provided on the inner peripheral surface of the chuck shaft 21.

[0017] The chuck shaft 21 is composed of a main body 21a connected to the output shaft of the motor and a stepped sleeve-shaped holder 21b connected to the tip of the main body 21a. Further, since the chuck shaft 21 is rotatably supported, the main body 21a and the holder 21b are configured to rotate integrally with the drive of the motor.

[0018] Also, the main body 21a and the holder 21b are connected so as to provide a predetermined gap between the stepped portion 21bb of the holder 21b and the tip portion 21aa of the main body 21a, and the gap forms a fitting groove 22 provided on the inner peripheral surface of the chuck shaft 21 described above. This fitting groove 22 forms an annular shape extending in the circumferential direction on the inner peripheral surface of the chuck shaft 21, and the coil spring 23 is housed so as to be fitted into the fitting groove 22.

[0019] The coil spring 23 is formed by connecting both ends of a general coil spring into an annular shape. Normally, the inner diameter side of the coil spring 23 is located inside the inner peripheral surface of the chuck shaft 21, that is, a part of the coil spring 23 is exposed from the inner peripheral surface of the chuck shaft 21.

[0020] Subsequently, when the driver bit 2 is inserted into the chuck shaft 21 of the chuck 20, the coil spring 23 is pushed and expanded by the driver bit 2, so that the inner diameter side of the coil spring 23 is pushed and expanded to a position outside the normal position.

[0021] After that, when the engaging groove 2a of the driver bit 2 reaches the position of the coil spring 23, the coil spring 23 that has been pushed and expanded outward returns to the normal position and is configured to hold the driver bit 2 by fitting with the engaging groove 2a of the driver bit 2.

[0022] On the other hand, when removing the driver bit 2 held by the chuck 20, pulling the driver bit 2 causes the coil spring 23 to elastically deform and expand outward. For this reason, the fitting between the coil spring 23 and the engaging groove 2a of the driver bit 2 is released, and the driver bit 2 can be removed from the chuck 20.

[0023] According to the chuck 20 of the electric driver 1, the driver bit 2 can be easily attached simply by inserting the driver bit 2 into the chuck 20 without the operator operating the chuck 20, and can be easily removed simply by pulling out the driver bit 2 from the chuck 20. Further, since the number of parts constituting the chuck 20 is small, it can be miniaturized.

[0024] In particular, the electric driver 1 is suitable for medical use in a surgical operation of screwing a medical screw into a fractured part. This is because the coil spring 23 used in the chuck 20 of the electric driver 1 is considerably damaged by the friction caused by the rotation of the driver bit 2. However, in a surgical operation, since the electric driver 1 is used with a lower torque compared to industrial applications, the damage received by the coil spring 23 is limited.

[0025] Note that the electric driver 1 can be variously modified without departing from the gist of the present invention. In the above embodiment, the coil spring 23 is shown as an example of the elastic member, but an elastic ring made of rubber may be used instead.

Explanation of reference numerals

[0026] 1 Electric driver 2 Driver bit 2a Engagement groove 10 Main body part 11 Switch 20 Chuck 21 Chuck shaft 21a Main body 21aa Tip part 21b Holder 21bb Step part 22 Fitting groove 23 Coil spring

Claims

1. In an electric driver having a chuck to which a driver bit is detachable, the chuck is composed of a sleeve-shaped chuck shaft that rotates as the motor is driven and into which the driver bit can be inserted, an annular groove provided on the inner peripheral surface of the chuck shaft, and an annular elastic member housed along this annular groove. The driver bit having an annular engagement groove on its outer peripheral surface is inserted into the chuck shaft, and the elastic member is fitted into the engagement groove of the driver bit, whereby the electric driver is configured to hold the driver bit.

2. The electric driver according to claim 1, wherein the elastic member of the chuck is configured by connecting coil springs in an annular shape.

3. The electric driver according to claim 1, wherein the inner diameter side of the elastic member of the chuck is normally positioned inside the inner peripheral surface of the chuck shaft, and is pushed and expanded to a position outside the inner peripheral surface of the chuck shaft as the driver bit is inserted. When the engagement groove of the driver bit reaches the position of the elastic member, it returns to its normal position and is configured to hold the driver bit by fitting with the engagement groove of the driver bit.

4. The electric driver according to claim 3, wherein the elastic member of the chuck is elastically deformed when the driver bit held by the chuck is pulled, and the driver bit is configured to be removed from the chuck by releasing the fit with the engagement groove of the driver bit.

5. The electric driver according to any one of claims 1 to 4, wherein the electric driver is for medical use and is used in a surgical operation for screwing a medical screw into a fractured part.

Images