Driver bit

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 technology]

[0002] The present applicant has proposed a driver bit for turning screws, such as the driver bit disclosed in Patent Document 1 (hereinafter referred to as a conventional example).

[0003] In this conventional example, the tip of the bit rod is provided with a fitting portion that fits into the recess in the screw head, and the base end is provided with a connecting portion that functions as a rotational force input portion that is connected to a rotating tool. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7010496 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional examples, if excessive rotational torque is applied to a fatigued area and the wire breaks, the broken tip portion falls off and, for example, gets into gaps in machinery, causing malfunctions, or causes current to flow between machines in live-line sites, leading to short circuits.

[0006] The present invention is the result of further development of the driver bit described above, resulting in the development of a driver bit that is unprecedented and highly practical. [Means for solving the problem]

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

[0008] This driver bit has a fitting portion 1a at the tip of the bit rod 1 that fits into a screw head 50a, the bit rod 1 is covered with a covering member 10, and the portion covered with this covering member 10 is provided with a locking portion 3 that engages with the covering member 10 through a concave-convex engagement, so that if the bit rod 1 breaks at a position closer to the base end than the locking portion 3, the portion further to the tip than the broken portion will not fall off and will be held by the covering member 10 due to the concave-convex engagement between the locking portion 3 and the covering member 10.

[0009] The present invention also relates to a driver bit as described in claim 1, characterized in that a breakable portion 2 that is more easily broken than other portions is provided in a region closer to the base end than the locking portion 3.

[0010] Furthermore, in the driver bit described in claim 2, the breakable portion 2 is configured to be easier to break by having a smaller diameter than other portions of the bit rod 1.

[0011] The present invention also relates to a driver bit as set forth in either claim 1 or claim 2, wherein the covering member 10 is made of synthetic resin.

[0012] The present invention also relates to a driver bit as set forth in claim 3, wherein the covering member 10 is made of synthetic resin.

[0013] Furthermore, in the driver bit described in either claim 1 or 2, the engaging portion 3 is characterized in that it is composed of a concave or convex portion that engages with the engaging portion 11, which is composed of a convex or concave portion provided on the covering member 10.

[0014] Furthermore, in the driver bit described in claim 3, the engaging portion 3 is characterized in that it is composed of a concave or convex portion that engages with the engaging portion 11, which is composed of a convex or concave portion provided on the covering member 10.

[0015] Furthermore, in the driver bit described in claim 4, the engaging portion 3 is characterized in that it is composed of a concave or convex portion that engages with the engaging portion 11, which is composed of a convex or concave portion provided on the covering member 10.

[0016] Furthermore, in the driver bit described in claim 5, the engaging portion 3 is characterized in that it is composed of a concave or convex portion that engages with the engaging portion 11, which is composed of a convex or concave portion provided on the covering member 10.

[0017] Furthermore, in the driver bit described in claim 6, the locking portion 3 is a ring-shaped locking portion that is a concave or convex strip having a length in a direction perpendicular to the longitudinal direction of the bit rod 1.

[0018] Furthermore, in the driver bit described in claim 7, the locking portion 3 is a ring-shaped locking portion that is a concave or convex strip having a length in a direction perpendicular to the longitudinal direction of the bit rod 1.

[0019] Furthermore, in the driver bit described in claim 8, the locking portion 3 is a ring-shaped locking portion that is a concave or convex strip having a length in a direction perpendicular to the longitudinal direction of the bit rod 1.

[0020] Furthermore, in the driver bit described in claim 9, the locking portion 3 is a ring-shaped locking portion that is a concave or convex strip having a length in a direction perpendicular to the longitudinal direction of the bit rod 1. [Effects of the Invention]

[0021] Since the present invention is configured as described above, it is possible to prevent the driver bit from falling off or dropping when broken, making it an unprecedented and highly practical driver bit. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a perspective view showing the present embodiment. [Figure 2] FIG. 2 is a cross-sectional view illustrating a main part of the present embodiment. [Figure 3] FIG. 2 is an explanatory diagram of the main part of the present embodiment. [Figure 4] FIG. 2 is an explanatory diagram of the use state of the present embodiment. [Figure 5] FIG. 10 is a cross-sectional view illustrating another example of the main part of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] A preferred embodiment of the present invention will be briefly described below, illustrating the operation of the present invention with reference to the drawings.

[0024] For example, if the portion of the bit rod 1 closer to the base end than the locking portion 3 breaks due to the large rotational torque generated when the screw 50 is screwed in, the portion closer to the tip end than the broken portion will not fall off due to the concave and convex locking of the locking portion 3 against the covering member 10.

[0025] Therefore, conventional problems such as the broken tip portion of the bit rod 1 falling into a gap in the machine and causing malfunction, or causing a short circuit when machines are energized at a live line site, are prevented. [Example]

[0026] Specific embodiments of the present invention will be described with reference to the drawings.

[0027] This embodiment is a driver bit K having a fitting portion 1a at the tip of the bit rod 1 that fits (fits into or is fitted over) the screw head 50a, the bit rod 1 is covered with a covering member 10, and the portion covered with this covering member 10 is provided with a locking portion 3 that engages with the covering member 10 through a concave-convex engagement, so that if the bit rod 1 breaks at a position closer to the base end than the locking portion 3, the portion further tip than the broken portion will not fall off and will be held by the covering member 10 due to the concave-convex engagement between the locking portion 3 and the covering member 10.

[0028] In this embodiment, the screw 50 is a screw 50 having a plus-shaped recess 50a' in the screw head 50a, but the screw 50 may also have a minus-shaped recess 50a' or a hex lobe-shaped or hexagonal socket-shaped recess 50a', and the screw head 50a may also be a polygonal bolt head (e.g., a hex bolt). In this case, the fitting portion 1a provided at the tip of the driver bit has a concave fitting structure (socket structure).

[0029] Specifically, the driver bit K according to this embodiment has a bit rod 1 made up of a first shank 1A having a fitting portion 1a at its tip end that fits into a recess 50a' in a screw head 50a, and a second shank 1B that is connected to the base end of the first shank 1A and functions as a rotational force input portion, and the first shank 1A and second shank 1B that make up the bit rod 1 are connected and joined via an insulating structure 5. The bit rod 1 may also be a single piece (integral piece) with no interruptions from the tip end to the base end.

[0030] As shown in FIG. 1, the first shank 1A is a shaft-shaped body made of an appropriate metal member, and has a distal shank 1A″ with a circular cross section provided at the tip of a base shank 1A′ with a hexagonal cross section, and a Phillips fitting portion 1a is provided at the tip of this distal shank 1A″ to fit into a Phillips-shaped recess 50a′ (recessed groove) in the screw head 50a. Note that the fitting portion 1a is not limited to a Phillips shape, and may have any shape that matches the recess 50a′ of the screw 50 as described above (a shape that is suitable for rotating the screw 50), and may be flat-head or hex lobe.

[0031] The bit rod 1 is covered with a covering member 10.

[0032] Specifically, first shaft portion 1A (tip-side shaft portion 1A") is covered by insert molding with a covering member 10 made of transparent insulating synthetic resin (polycarbonate), and this covering member 10 functions to prevent electric shock due to a short circuit by minimizing exposed metal portions. From the perspective of confirming that bit rod 1 has broken, covering member 10 only needs to be transparent in the portion that covers easy-to-break portion 2, which will be described later. Covering member 10 may also be made with an insulating tube made of a synthetic resin that has appropriate flexibility. It is desirable that covering member 10 be flexible enough not to break even if bit rod 1 breaks, and that covering member 10 has enough elasticity so that the engagement with engagement portion 3 is not released.

[0033] In addition, the portion of the bit rod 1 (first shaft portion 1A) that is covered by the covering member 10 is provided with a locking portion 3 that engages with the covering member 10 through projections and recesses, and if the bit rod 1 breaks at a position closer to the base end than the locking portion 3, the portion further to the tip than the broken portion will not fall off and will be held by the covering member 10 due to the locking of the locking portion 3.

[0034] Specifically, the locking portion 3 is configured by providing a ring-shaped locking portion consisting of a recessed stripe having a length in a direction perpendicular to the longitudinal direction of the bit rod 1 on the peripheral surface of the bit rod 1, and is configured to engage with the locked portion 11 (the portion that is filled into the recessed locking portion 3 during insert molding) of the ring-shaped protrusion provided on the inner surface of the covering member 10 that covers this recessed stripe.

[0035] Therefore, the portion of the bit rod 1 closer to the tip than the fractured portion does not fall off but is held in place by the covering member 10, and since the covering member 10 is transparent, the fractured portion of the fragile portion 2, which will be described later, can be visually confirmed.

[0036] As shown in FIG. 5, the locking portion 3 may be a convex portion (annular convex stripe), and the locked portion 11 may be a concave portion (annular concave stripe).

[0037] In addition, a breakable portion 2 that is more easily broken than other portions is provided in the base end portion of the bit rod 1 than the locking portion 3, and this breakable portion 2 is configured to be easier to break by having a smaller diameter than other portions of the bit rod 1.

[0038] Specifically, as shown in Figure 3, the breakable portion 2 is formed (cut) with a smaller diameter than the locking portion 3 and other portions of the bit rod 1, and this configuration makes it more likely to break than other portions due to rotational torque (rotational torque of a magnitude greater than a predetermined value).

[0039] Therefore, for example, if the breakable portion 2, which is the portion of the bit rod 1 closer to the base end than the locking portion 3, breaks due to the large rotational torque generated when screwing in the screw 50, the portion closer to the tip end than the broken portion will not fall off or drop off due to the concave and convex engagement of the locking portion 3 with the covering member 10.

[0040] Regarding the provision of this locking portion 3 and breakable portion 2, the driver bit K (bit rod 1) can be made less likely to break by, for example, modifying its shape or using a hard material, but as mentioned above, there remains the possibility that it will eventually break due to metal fatigue, and it is not realistic to have a driver bit K (bit rod 1) that will never break. Therefore, measures to prevent it from falling off or dropping are necessary, assuming that it will break.

[0041] Therefore, in this embodiment, as a measure to prevent the portion tipping further than the fractured portion from falling off or dropping off, the bit rod 1 is covered with a covering member 10, and the portion covered with this covering member 10 is provided with a locking portion 3 that engages with the covering member 10 via a concave-convex engagement, so that if the bit rod 1 breaks at a portion base-end further than this locking portion 3, the portion tipping further than the fractured portion can be prevented from falling off or dropping off.

[0042] However, if the breakage occurs at a location further forward than the locking portion 3, the portion further forward than the breakage location will fall off.

[0043] Therefore, in this embodiment, the breakable portion 2 is provided to prevent breakage as much as possible at the portion closer to the tip end than the locking portion 3. Incidentally, the breakable portion 2 is, of course, provided on the premise that it has a predetermined strength (durability) that can withstand the normal rotational torque that occurs when the screw 50 is fastened.

[0044] Furthermore, the fragile portion 2 is not limited to a structure in which a difference in strength is created by a difference in diameter as described above, but may be made of a material that is weaker than other portions, or a weak portion may be created by joining components together.

[0045] The first shaft portion 1A (base end shaft portion 1A') has three recesses 1b at equal intervals on its circumferential surface, and each recess 1b is for fitting an insert molding material that will form a connecting portion (described later). Each recess 1b may be elongated.

[0046] As shown in FIG. 1, the second shaft portion 1B is a shaft-shaped body with a hexagonal cross section formed from an appropriate metal member, and has a connecting portion 4 at its base end that is connected to a rotary tool 40.

[0047] This connecting portion 4 is configured by providing a groove 4a on the base end side peripheral surface of the second shaft portion 1B, and when inserted into an insertion mounting recess 40a provided in the rotating portion of the rotating tool 40, a spherical locking member that is capable of being protruded and retracted into this insertion mounting recess 40a engages to prevent it from coming loose.

[0048] In this embodiment, an electric screwdriver is used as the rotary tool 40, but a torque screwdriver or the like may also be used.

[0049] The second shaft portion 1B has three recesses 1b formed at equal intervals on its circumferential surface, and each recess 1b is for fitting an insert molding material that forms the connecting member 5'. Each recess 1b may be in the form of an elongated groove.

[0050] The first shaft portion 1A and the second shaft portion 1B are connected together via an insulating structure portion 5.

[0051] 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 with each other, i.e., a gap S is provided between the two.

[0052] This connecting member 5' is constructed by insert molding an appropriate 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 arranged 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, and any material having the insulating properties and strength required to exhibit the characteristics of this embodiment can be used as appropriate.

[0053] Furthermore, the gap S between the first shaft portion 1A and the second shaft portion 1B, which are connected via the connecting member 5', is, for example, a distance (approximately 3 mm) that prevents current from flowing from the first shaft portion 1A to the second shaft portion 1B. This distance is set appropriately.

[0054] Furthermore, the connecting member 5' has a structure in which its diameter is larger than that of the first shaft portion 1A and the second shaft portion 1B, and strength against twisting directions is maintained.

[0055] Incidentally, if the entire bit rod 1 is made of insulating synthetic resin, it will not conduct electricity, but it will be weaker in strength.

[0056] Therefore, the first shaft portion 1A on which the fitting portion 1a is provided and the second shaft portion 1B which functions as the rotational force input portion are made of metal, and the first shaft portion 1A and the second shaft portion 1B are connected via a connecting member 5' made of insulating synthetic resin, thereby making it possible to prevent electrical conduction while ensuring strength.

[0057] However, simply gluing the end faces of connecting members 5' of approximately the same diameter as the first and second shaft portions 1A and 1B to the end faces of these shaft portions would not be strong enough. Therefore, in this embodiment, a connecting member 5' of a larger diameter is provided between the first and second shaft portions 1A and 1B by insert molding, thereby achieving strength sufficient for use.

[0058] The connecting member 5' has six flat surfaces on its circumferential surface, and is configured so that when the driver bit K according to this embodiment is placed on a placement surface, it does not roll easily and the first shaft portion 1A is in a non-contact state. The connecting member 5' may be a hollow body (hollow vacuum body) with an internal space.

[0059] The base and tip ends of the bit rod 1 are provided with mating portions 1a that mate with the screw head 50a, and the tip and base ends of the bit rod 1 are provided with connecting portions 4 that are connected to a rotating tool, and both the tip and base ends of the bit rod 1 may 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 configured to function as a rotational force input portion.Furthermore, the bit rod 1 is not limited to one equipped with the insulating structure portion 5 as described above, but may be a single bit rod 1 from the tip to the base end, and any structure that exhibits the characteristics of this embodiment may be adopted as appropriate.

[0060] Since this embodiment is configured as described above, the driver bit K according to this embodiment is attached to the rotary tool 40, the fitting portion 1a of the bit rod 1 (first shank 1A) is fitted into the recess 50a' of the screw head 50a, and in this state the rotary tool 40 is operated to rotate the second shank 1B, thereby screwing the screw 50. Note that, since the first shank 1A and the second shank 1B are connected via the insulating structure 5, no current flows from the first shank 1A to the second shank 1B.

[0061] For example, if the large rotational torque generated when screwing this screw 50 causes the base end portion of the bit rod 1 closer to the locking portion 3 (the breakable portion 2) to break, the portion closer to the tip end than the broken portion will not fall off or drop off and will be held by the covering member 10 due to the uneven engagement of the locking portion 3 with the covering member 10.

[0062] Therefore, according to this embodiment, conventional problems such as the broken tip portion of the bit rod 1 falling into the gaps in the machine and causing malfunctions, or causing a short circuit when machines are energized at a live line site, are prevented.

[0063] Furthermore, in this embodiment, the breakable portion 2, which is more easily broken than other portions, is provided in the region closer to the base end than the locking portion 3, so that the above-mentioned effects can be easily and reliably achieved.

[0064] In addition, in this embodiment, the breakable portion 2 is configured to be easier to break by having a smaller diameter than other portions of the bit rod 1, so in this respect too the aforementioned effects can be achieved easily and reliably.

[0065] Furthermore, in this embodiment, the covering member 10 is made of synthetic resin, so the covering member 10 will not break and the above-mentioned effects can be reliably achieved.

[0066] In addition, in this embodiment, the covering member 10 is made of a transparent synthetic resin, so the worker can see at a glance the location of the broken part of the bit rod 1.

[0067] Furthermore, in this embodiment, the locking portion 3 is composed of a recess (or convex portion) that engages with the locked portion 11, which is composed of a convex portion (or concave portion) provided on the covering member 10, so that in this respect too the aforementioned functional effects can be easily and reliably achieved.

[0068] In addition, in this embodiment, the locking portion 3 is a concave (or convex) having a length in a direction perpendicular to the longitudinal direction of the bit rod 1, so in this respect too the aforementioned effects can be easily and reliably achieved.

[0069] Furthermore, this embodiment can prevent as much as possible electric shock when, for example, removing or installing a screw 50 in a live wire location, and can also prevent as much as possible damage to the rotary tool 40 caused by current flow, which previously occurred.

[0070] In addition, 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 formed by a gap S of a distance that prevents current from flowing from the first shaft portion 1A to the second shaft portion 1B, so that the above-mentioned effects can be reliably obtained.

[0071] In addition, in this embodiment, the connecting member 5' is an appropriate transparent member, so 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), giving him a sense of security.

[0072] In addition, in this embodiment, the connecting member 5' has a larger diameter than the first shaft portion 1A and the second shaft portion 1B, and furthermore, the connecting member 5' has a flat surface portion 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, which prevents damage to the fitting portion 1a and the covering member 10, and also prevents the driver bit K from rolling on the mounting surface.

[0073] Furthermore, in this embodiment, the connecting member 5' is provided between the first shaft portion 1A and the second shaft portion 1B by insert molding, so that the above-mentioned structure can be obtained simply and reliably.

[0074] In addition, in this embodiment, the first shaft portion 1A has a recess 1b at the connecting portion with the connecting member 5' into which the insert molding material fits, and the second shaft portion 1B has a recess 1b at the connecting portion with the connecting member 5' into which the insert molding material fits, so the connection (integration) between the first shaft portion 1A and the second shaft portion 1B and the connecting member 5' is strong.

[0075] As described above, the driver bit K is not limited to this embodiment. For example, the base end of the second shank 1B may also be provided with a fitting portion 1a that fits into the recess 50a' of the screw head 50a, and the first shank 1A may also be provided with a connecting portion 4 that is connected to the rotary tool 40, so that the first shank 1A also functions as a rotational force input portion. That is, the driver bit K may have fitting portions 1a and connecting portions 4 provided at both left and right ends of the bit rod 1. Alternatively, the driver bit K may be configured as a hand driver in which a grip portion for holding is provided at the base end of the bit rod 1 (second shank 1B) that constitutes the driver bit K, or the grip portion may be detachable from the grip portion. In other words, the distal end and proximal end of the driver bit K as used herein refer to the end that fits into the screw head 50a during use (when screwing) as the distal end, and the end that functions as a rotational force input portion as the proximal end.

[0076] The present invention is not limited to this embodiment, and the specific configuration of each component can be designed as appropriate. [Explanation of symbols]

[0077] 1 bit rod 1a Fitting part 2. Fracture prone parts 3 Locking part 10 Covering material 11 Locked part 50a screw head

Claims

1. A driver bit having a fitting portion at the tip of a bit rod that fits into a screw head, the bit rod being covered with a covering member, and the portion covered by the covering member being provided with a locking portion that engages with the covering member through a concave-convex engagement, so that if the bit rod breaks at a position closer to the base end than the locking portion, the portion further to the tip than the breakage portion will not fall off and will be held by the covering member due to the concave-convex engagement between the locking portion and the covering member.

2. 2. The driver bit according to claim 1, wherein a breakable portion that is more easily broken than other portions is provided in a portion closer to the base end than the locking portion.

3. 3. The driver bit according to claim 2, wherein the breakable portion is configured to be easily broken by being smaller in diameter than other portions of the bit rod.

4. 3. The driver bit according to claim 1, wherein the covering member is made of a synthetic resin.

5. 4. The driver bit according to claim 3, wherein the covering member is made of a synthetic resin.

6. 3. The driver bit according to claim 1, wherein the engaging portion is configured as a concave or convex portion that engages with a mating portion configured as a convex or concave portion provided on the covering member.

7. 4. The driver bit according to claim 3, wherein the engaging portion is configured as a concave or convex portion that engages with a mating portion configured as a convex or concave portion provided on the covering member.

8. 5. The driver bit according to claim 4, wherein the engaging portion is configured as a concave or convex portion that engages with a mating portion configured as a convex or concave portion provided on the covering member.

9. 6. The driver bit according to claim 5, wherein the engaging portion is configured as a concave or convex portion that engages with a mating portion configured as a convex or concave portion provided on the covering member.

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

11. 8. The driver bit according to claim 7, wherein the locking portion is an annular locking portion that is a concave or convex strip having a length in a direction perpendicular to the longitudinal direction of the bit rod.

12. 9. The driver bit according to claim 8, wherein the locking portion is an annular locking portion that is a concave or convex strip having a length in a direction perpendicular to the longitudinal direction of the bit rod.

13. 10. The driver bit according to claim 9, wherein the locking portion is an annular locking portion that is a concave or convex strip having a length in a direction perpendicular to the longitudinal direction of the bit rod.

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