Driver bits

Abstract

To provide a driver bit very excellent in practicality which has never existed.SOLUTION: The present invention relates to a driver bit, which is provided with a fitting part 1a fitted with a screw head 50a at a tip of a bit rod 1, wherein the bit rod 1 is covered with a covering member 10, a part covered with the covering member 10 is provided with an engagement part 3 for concave-convex engagement with the covering member 10, and a tip-side part than a broken part does not fall and held by the covering member 10 as a result of the concave-convex engagement of the engagement part 3 with the covering member 10 in the case that the bit rod 1 breaks on a base end side than the engagement part 3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a driver bit.

Background Art

[0002] The applicant has proposed a driver bit for rotating a screw, for example, the driver bit disclosed in Patent Document 1 (hereinafter, the conventional example).

[0003] This conventional example has a configuration in which a fitting portion that fits into a recess of a screw head is provided at the tip of the bit rod, and a connecting portion is provided at the base end portion so as to function as a rotational force input portion connected to a rotating tool.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the conventional example, when it breaks under excessive rotational torque at a location with metal fatigue, the broken tip-side portion drops off. For example, it may get into the gap of a machine and cause problems, or cause a short circuit between machines at a live wire site, etc.

[0006] As a result of further developing the above-described driver bit, the present invention has developed a driver bit that is extremely practical and unprecedented.

Means for Solving the Problems

[0007] The gist of the present invention will be described with reference to the accompanying drawings.

[0008] A screwdriver bit having a fitting portion 1a at the tip of the bit rod 1 that fits with a screw head 50a, wherein the bit rod 1 is covered with a covering member 10, and the portion covered by the covering member 10 is provided with a locking portion 3 that engages with the covering member 10 through its interlocking grooves. Furthermore, a portion closer to the base end than the locking portion 3 is provided with an easily breakable portion 2 that is more prone to breaking than other portions. The present invention relates to a driver bit characterized in that, if the bit rod 1 breaks at the base end side of the locking portion 3, the portion on the tip side of the break does not fall off due to the interlocking of the locking portion 3 and the covering member 10, and is held in place by the covering member 10.

[0009] Furthermore, claims 1 The driver bit described is characterized in that the easily breakable portion 2 is provided with a smaller diameter than other parts of the bit rod 1, thereby making it easier to break.

[0010] Furthermore, the present invention relates to a driver bit according to either claim 1 or 2, characterized in that the covering member 10 is made of synthetic resin.

[0011] Furthermore, in the driver bit according to either claim 1 or 2, the locking portion 3 is a convex or concave portion provided on the covering member 10. Part and concave Convex recess or protrusion for locking That is This relates to a driver bit characterized by the following features.

[0012] Furthermore, in the driver bit according to claim 3, the locking portion 3 is a convex or concave portion provided on the covering member 10. Part and concave Convex recess or protrusion for locking That is This relates to a driver bit characterized by the following features.

[0013] Furthermore, claims 4 In the driver bit described, the locking portion 3 is a groove or protrusion having a length perpendicular to the longitudinal direction of the bit rod 1. The annular part that is formed This relates to a driver bit characterized by the following:

[0014] Also, in the driver bit according to claim 5 the locking portion 3 is a concave or convex strip having a length in a direction orthogonal to the longitudinal direction of the bit shank 1 The annular part that is formed and relates to a driver bit characterized by this.

Advantages of the Invention

[0015] Since the present invention is configured as described above, it becomes a driver bit that is extremely practical and has no prior art problems such as preventing dropping and falling when broken.

Brief Description of the Drawings

[0016] [Figure 1] It is a perspective view showing this embodiment. [Figure 2] It is a cross-sectional view explaining the main part of this embodiment. [Figure 3] It is an explanatory view of the main part of this embodiment. [Figure 4] It is an explanatory view of the usage state of this embodiment. [Figure 5] It is a cross-sectional view explaining another example of the main part of this embodiment.

Modes for Carrying Out the Invention

[0017] Preferred embodiments of the present invention will be briefly described based on the drawings to show the operation of the present invention.

[0018] For example, when a base end side portion of the bit shank 1 breaks due to a large rotational torque generated during screwing of the screw 50, the uneven locking of the locking portion 3 with respect to the covering member 10 prevents the tip side portion from dropping off compared to the broken portion.

[0019] Therefore, conventional problems such as the broken tip side portion of the bit shank 1 falling into the gap of the machine and causing problems, or causing a short circuit when energizing machines at a live wire site are prevented.

Examples

[0020] Specific embodiments of the present invention will be described with reference to the drawings.

[0021] This embodiment provides a screwdriver bit K in which a fitting portion 1a is provided at the tip of the bit rod 1 to fit (fit into or be fitted with) a screw head 50a, the bit rod 1 is covered with a covering member 10, and the portion covered by the covering member 10 is provided with a locking portion 3 that engages with the covering member 10 in a grooved manner, and if the bit rod 1 breaks on the base end side of the locking portion 3, the portion on the tip side of the broken part does not fall off due to the grooved engagement between the locking portion 3 and the covering member 10 and is held by the covering member 10.

[0022] In this embodiment, a screw 50 is used which has a Phillips-shaped recess 50a' in the screw head 50a. However, a screw 50 with a minus-shaped recess 50a', or a hexalobular or hexagonal socket recess 50a', may also be used. Furthermore, the screw head 50a may be a polygonal bolt head (for example, a hexagonal bolt). In this case, the fitting portion 1a provided at the tip of the driver bit will be a concave fitting structure (socket structure).

[0023] Specifically, the driver bit K according to this embodiment has a bit rod 1 consisting of a first shaft portion 1A with a fitting portion 1a at its tip that fits into a recess 50a' of the screw head 50a, and a second shaft portion 1B connected to the base end of the first shaft portion 1A and functioning as a rotational force input portion. The first shaft portion 1A and the second shaft portion 1B constituting the bit rod 1 are joined together via an insulating structure portion 5. The bit rod 1 may also be a single piece (integrated) without any interrupted parts from the tip to the base end.

[0024] The first shaft portion 1A is a shaft-shaped body formed from a suitable metal member, as shown in Figure 1. A circular cross-section tip-side shaft portion 1A'' is provided at the tip of the base-side shaft portion 1A', which has a hexagonal cross-section. The tip of this tip-side shaft portion 1A'' is provided with a positive-shaped fitting portion 1a that fits into the positive-shaped recess 50a' (groove) of the screw head 50a. Note that the fitting portion 1a is not limited to positive-shaped; any shape that fits the recess 50a' of the screw 50 (a shape suitable for rotating the screw 50) as described above is acceptable, and it may be a slotted or hexalobular shape.

[0025] Furthermore, the bit rod 1 is covered with a covering member 10.

[0026] Specifically, the first shaft portion 1A (the tip-side shaft-shaped portion 1A") is covered by insert molding with a transparent synthetic resin (polycarbonate) covering member 10 that has insulating properties. This covering member 10 functions to prevent electric shock due to short circuits by minimizing the exposure of metal parts. Furthermore, from the viewpoint of confirming that the bit rod 1 has broken, it is sufficient that at least the portion covering the easily breakable portion 2 (described later) of the covering member 10 is transparent. Alternatively, it may be covered with an insulating tube made of synthetic resin with appropriate flexibility. Even if the bit rod 1 breaks, it is desirable that the covering member 10 flexibly adapts and does not break, and that it has enough elasticity to prevent the interlocking with the locking portion 3 from being released.

[0027] Furthermore, the portion of the bit rod 1 (first shaft portion 1A) covered by the covering member 10 is provided with a locking portion 3 that engages with the covering member 10. If the bit rod 1 breaks at the base end side of the locking portion 3, the portion at the tip side of the break will not fall off due to the locking of the locking portion 3 and will be held in place by the covering member 10.

[0028] Specifically, the locking portion 3 is configured to have an annular locking portion on the circumferential surface of the bit rod 1, consisting of a recess having a length perpendicular to the longitudinal direction of the bit rod 1, and the locking portion 11 of the annular protrusion provided on the inner surface of the covering member 10 that covers the recess is configured to lock onto this recess.

[0029] Therefore, the tip portion of the bit rod 1 beyond the fracture site does not fall off but is held by the covering member 10, and furthermore, since the covering member 10 is transparent, the fracture site of the easily fractured portion 2, which will be described later, can be visually confirmed.

[0030] Furthermore, as shown in Figure 5, the locking portion 3 may be a convex portion (annular convex ridge) and the locked portion 11 may be a concave portion (annular concave ridge).

[0031] Furthermore, the bit shaft 1 has a portion closer to the base end than the locking portion 3 that is more prone to breaking than other portions, and this easily breakable portion 2 is configured to be easier to break by having a smaller diameter than other portions of the bit shaft 1.

[0032] Specifically, as shown in Figure 3, the easily breakable portion 2 is provided with a smaller diameter than the locking portion 3 and other parts of the bit rod 1 (formed by cutting), and this configuration makes it easier to break than other parts due to rotational torque (rotational torque of a predetermined value or greater).

[0033] Therefore, for example, if the easily breakable portion 2, which is the base end portion of the bit rod 1, breaks due to a large rotational torque generated when screwing in the screw 50, the portion on the tip side of the broken portion will not fall off due to the interlocking of the interlocking portion 3 with the covering member 10.

[0034] Regarding the provision of the locking portion 3 and the easily breakable portion 2, it should be noted that the screwdriver bit K (bit shaft 1) can be made to be less prone to breakage by, for example, modifying its shape or using a harder material. However, as mentioned above, there remains a possibility that it will eventually break due to metal fatigue. A screwdriver bit K (bit shaft 1) that will never break is not realistic, and therefore, measures to prevent detachment and dropping are necessary, assuming that it will break.

[0035] Therefore, in this embodiment, as a measure to prevent the tip portion from falling off or dropping from the fractured portion, the bit rod 1 is covered with a covering member 10, and the portion covered by the covering member 10 is provided with a locking portion 3 that engages with the covering member 10 through its grooves and protrusions. If the bit breaks at the base end portion beyond the locking portion 3, it is possible to prevent the tip portion from falling off or dropping from the fractured portion.

[0036] However, if the part breaks at the tip end of the locking portion 3, the tip end of the broken portion will detach and fall off.

[0037] Therefore, in this embodiment, a breakable portion 2 is provided to prevent breakage at the tip end of the locking portion 3 as much as possible. Incidentally, this breakable portion 2 is provided on the premise that it has a predetermined strength (durability) that can withstand the normal rotational torque generated when the screw 50 is screwed in.

[0038] Furthermore, the easily fractured portion 2 is not limited to a structure in which a difference in strength is created by a difference in diameter, as mentioned above. For example, it may be made of a material that is weaker than other parts, or a weak portion may be created by joining members together.

[0039] Furthermore, the first shaft portion 1A (base end shaft portion 1A') has three recesses 1b at equal intervals on its circumferential surface, and each of these recesses 1b is for fitting the insert molding material that constitutes the connecting portion described later. These recesses 1b may also be elongated in shape.

[0040] The second shaft portion 1B is a shaft-shaped body with a hexagonal cross-section formed from a suitable metal member, as shown in Figure 1, and a connecting portion 4 is provided at its base end for connection to the rotating tool 40.

[0041] This connecting portion 4 is constructed by providing a groove 4a on the base end side circumferential surface of the second shaft portion 1B. When it is fitted into the insertion mounting recess 40a provided on the rotating portion of the rotating tool 40, a spherical locking member, which is provided to be retractable into the insertion mounting recess 40a, locks into place, preventing it from coming loose.

[0042] In this embodiment, an electric screwdriver is used as the rotating tool 40, but a torque screwdriver or similar tool may also be used.

[0043] Furthermore, the second shaft portion 1B is provided with three recesses 1b at equal intervals on its circumferential surface. Each of these recesses 1b is for fitting the insert molding material that constitutes the connecting member 5'. These recesses 1b may also be in the shape of elongated grooves.

[0044] Furthermore, the first shaft portion 1A and the second shaft portion 1B are connected via an insulating structure portion 5.

[0045] Specifically, the first shaft portion 1A and the second shaft portion 1B are connected by a connecting member 5', and the base end of the first shaft portion 1A and the tip end of the second shaft portion 1B are not in contact; that is, a gap S is provided between them.

[0046] This connecting member 5' is constructed by insert molding a suitable transparent resin (polycarbonate resin) between the first shaft portion 1A and the second shaft portion 1B, and the tip portion of this connecting member 5' is provided to cover the base end portion of the covering member 10. The material constituting the connecting member 5' is not limited to those described above; any material with insulating and strong properties that exhibits the characteristics of this embodiment can be used as appropriate.

[0047] Furthermore, the gap S between the first shaft portion 1A and the second shaft portion 1B, which are connected via this connecting member 5', is a gap S of approximately 3 mm, for example, that prevents current from flowing from the first shaft portion 1A to the second shaft portion 1B. This distance is set as appropriate.

[0048] Furthermore, the connecting member 5' has a larger diameter than the first shaft portion 1A and the second shaft portion 1B, thereby maintaining strength against torsional forces.

[0049] Incidentally, if the entire bit rod 1 were made of an insulating synthetic resin, it would not conduct electricity, but it would be weaker in terms of strength.

[0050] Therefore, by making the first shaft portion 1A, which is provided with the fitting portion 1a, and the second shaft portion 1B, which functions as a rotational force input portion, out of metal, and by connecting the first shaft portion 1A and the second shaft portion 1B via an insulating synthetic resin connecting member 5', it is possible to prevent current flow while ensuring strength.

[0051] However, simply bonding the end faces of connecting members 5', which have approximately the same diameter as the shafts, to the end faces of the first shaft portion 1A and the second shaft portion 1B respectively would result in insufficient strength. Therefore, in this embodiment, sufficient strength for use can be obtained by providing a larger diameter connecting member 5' between the first shaft portion 1A and the second shaft portion 1B using insert molding.

[0052] Furthermore, the connecting member 5' is provided with six flat surfaces on its circumferential surface, and is configured such that when the driver bit K according to this embodiment is placed on the mounting surface, it is less likely to roll and the first shaft portion 1A remains in a non-contact state. Note that the connecting member 5' may also be a hollow body (hollow vacuum body) with an internal space.

[0053] Furthermore, the bit rod 1 may be provided with a fitting portion 1a that engages with the screw head 50a at its base and tip ends, and a connecting portion 4 that connects to a rotating tool at its tip and base ends. The tip and base ends of the bit rod 1 may both be configured to function as rotational force input portions, or the base end of the bit rod 1 may be provided with a handle portion and the base end of the bit rod 1 may function as a rotational force input portion. Moreover, the bit rod 1 may be a single piece from tip to base, not limited to those equipped with the insulating structure portion 5 as described above, and any structure that exhibits the characteristics of this embodiment may be adopted as appropriate.

[0054] As this embodiment is configured as described above, the driver bit K according to this embodiment is attached to the rotating tool 40, the fitting portion 1a of the bit rod 1 (first shaft portion 1A) is inserted into the recess 50a' of the screw head 50a, and the rotating tool 40 is operated in this state to rotate the second shaft portion 1B, thereby screwing in the screw 50. Note that since the first shaft portion 1A and the second shaft portion 1B are connected via an insulating structure portion 5, no current flows from the first shaft portion 1A to the second shaft portion 1B.

[0055] For example, if the base end portion (easily breakable portion 2) of the bit rod 1 breaks due to the large rotational torque generated when the screw 50 is screwed in, the tip end portion will not fall off and will be held by the covering member 10 due to the interlocking of the interlocking portion 3 with the covering member 10.

[0056] Therefore, according to this embodiment, conventional problems such as the broken tip portion of the bit rod 1 falling off and getting into the gaps of the machine causing malfunctions, or causing a short circuit by energizing machines together in a live-line environment, are prevented.

[0057] Furthermore, in this embodiment, a portion closer to the base end than the locking portion 3 is provided with an easily breakable portion 2, which is more prone to breaking than other portions. Therefore, the aforementioned effects can be achieved simply and reliably.

[0058] Furthermore, in this embodiment, the easily breakable portion 2 is configured to be easier to break by having a smaller diameter than other parts of the bit rod 1, so in this respect as well, the aforementioned effects can be achieved simply and reliably.

[0059] Furthermore, in this embodiment, since the covering member 10 is made of synthetic resin, the covering member 10 will not break, and the effects described above can be reliably achieved.

[0060] Furthermore, in this embodiment, since the covering member 10 is made of transparent synthetic resin, the operator can easily identify the broken part of the bit rod 1 at a glance.

[0061] Furthermore, in this embodiment, the locking portion 3 is composed of a recess (or protrusion) that interlocks with the locked portion 11, which is composed of a protrusion (or recess) provided on the covering member 10. Therefore, the aforementioned effects and advantages can be achieved simply and reliably in this respect as well.

[0062] Furthermore, in this embodiment, the locking portion 3 is a concave (or convex) groove having a length perpendicular to the longitudinal direction of the bit rod 1, so the aforementioned effects can be achieved simply and reliably in this respect as well.

[0063] Furthermore, this embodiment can prevent electric shock as much as possible when, for example, attaching or detaching screws 50 at live wire locations, and can also prevent damage to the rotating tool 40 due to current flow, which occurred in the past.

[0064] Furthermore, in this embodiment, the first shaft portion 1A and the second shaft portion 1B are connected by a connecting member 5', and the base end of the first shaft portion 1A and the tip end of the second shaft portion 1B are not in contact with each other at the connecting member 5'. This non-contact is configured as a gap S of a distance that prevents current from flowing from the first shaft portion 1A to the second shaft portion 1B, thus ensuring that the aforementioned effects are reliably obtained.

[0065] Furthermore, in this embodiment, since the connecting member 5' is a suitable transparent material, the worker can see at a glance that it is an insulating structure (a structure in which there is a gap S between the first shaft portion 1A and the second shaft portion 1B), which provides a sense of security.

[0066] Furthermore, in this embodiment, the connecting member 5' has a larger diameter than the first shaft portion 1A and the second shaft portion 1B, and the connecting member ' is provided with a flat surface on its circumferential surface. Therefore, when the driver bit K is placed on the mounting surface, the first shaft portion 1A is in a non-contact state, preventing damage to the fitting portion 1a and the covering member 10, and also preventing it from rolling on the mounting surface.

[0067] Furthermore, in this embodiment, since the connecting member 5' is provided between the first shaft portion 1A and the second shaft portion 1B by insert molding, the aforementioned structure can be obtained simply and reliably.

[0068] Furthermore, in this embodiment, the first shaft portion 1A is provided with a recess 1b into which an insert molding material fits at the connection point with the connecting member 5', and the second shaft portion 1B is also provided with a recess 1b into which an insert molding material fits at the connection point with the connecting member 5', thus ensuring a firm connection (integration) between the first shaft portion 1A and the second shaft portion 1B and the connecting member 5'.

[0069] As described above, the driver bit K is not limited to this embodiment. For example, the base end of the second shaft portion 1B may also be provided with a fitting portion 1a that fits into the recess 50a' of the screw head 50a, and the first shaft portion 1A may also be provided with a connecting portion 4 that connects to the rotating tool 40, so that the first shaft portion 1A also functions as a rotational force input portion. In other words, the driver bit K may have fitting portions 1a and connecting portions 4 provided at both the left and right ends of the bit rod 1. Alternatively, the driver bit K may be configured as a hand-operated screwdriver with a grip portion for holding provided at the base end of the bit rod 1 (second shaft portion 1B) that constitutes the driver bit K, or it may be detachably attached to the grip portion. In other words, in this specification, the tip portion and base end of the driver bit K refer to the end that fits into the screw head 50a during use (when screwing) as the tip portion, and the end that functions as a rotational force input portion as the base end.

[0070] Furthermore, the present invention is not limited to this embodiment, and the specific configuration of each constituent element can be designed as appropriate. [Explanation of symbols]

[0071] 1 bit rod 1a Fitting part 2. Easily breakable portion 3. Locking part 10 Covering member 50a Screw head

Claims

1. A screwdriver bit having a fitting portion at the tip of the bit shaft that fits with a screw head, wherein the bit shaft is covered with a covering member, the portion covered by the covering member is provided with a locking portion that engages with the covering member through its grooves and protrusions, and the portion closer to the base end than the locking portion is provided with a breakable portion that is more prone to breaking than other portions, and if the bit shaft breaks at the base end of the locking portion, the portion closer to the tip of the broken portion is held in place by the covering member without falling off due to the grooves and protrusions engaging between the locking portion and the covering member.

2. A driver bit according to claim 1, characterized in that the easily breakable portion is provided with a smaller diameter than other parts of the bit rod so that it is easily broken.

3. A driver bit according to either claim 1 or 2, characterized in that the covering member is made of synthetic resin.

4. A driver bit according to either claim 1 or 2, characterized in that the locking portion is a recess or protrusion that locks with a protrusion or recess provided on the covering member.

5. The screwdriver bit according to claim 3, characterized in that the locking portion is a recess or protrusion that locks with a protrusion or recess provided on the covering member.

6. The driver bit according to claim 4, wherein the locking portion is an annular portion composed of a concave or convex groove having a length in a direction perpendicular to the longitudinal direction of the bit rod.

7. The screwdriver bit according to claim 5, characterized in that the locking portion is an annular portion composed of a concave or convex groove having a length in a direction perpendicular to the longitudinal direction of the bit rod.

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