JPH10202545A - Driver bit for cross-flat screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driver bit for cross-flat head screw which is capable of effectively preventing a come-out phenomenon of a driver bit, preventing damage when an attaching/detaching operation of a screw is performed in a conventional way, always attaining proper and quick screw attaching/detaching work and improving work efficiency by improving constitution of the tip of an edge part which can be fitted to the bit fitting groove of a cross-flat head screw. SOLUTION: This driver bit is constituted of a driver bit for cross-flat head screw which is applied to a cross-flat head screw provided with a bit fitting groove formed by a pair of a linear grooves constituted of an inclined groove part and a horizontal groove part crossing at the center part of a screw head part. The driver bit is provided with a flat edge part 32 forming an inclined end edge part 33a fitting along the inclined groove part of the cross-flat head screw. The driver bit is provided with a flat edge part 34 forming a horizontal end edge part 35 which is crossed with this flat edge part 32 at a right angle, fits along the horizontal groove part of the cross-flat head screw, extends at a roughly right angle and is abutted on the groove bottom surface of the horizontal groove part. At the tip center part of each edge part 32, 34, a projection 36 fitting in a conical bottom surface provided at the center of the screw head part of the cross-flat head screw.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw provided with a bit fitting groove adapted to a plus screwdriver bit and a minus screwdriver bit, that is, a driver bit applied to a plastic screw, and more particularly to a screw head. The fitting between the bit fitting groove consisting of a cross groove formed in the part and the driver bit corresponding to this is performed tightly,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screwdriver bit for a plumbing screw that can quickly and reliably achieve screw mounting and removal by proper torque transmission.

[0002]

2. Description of the Related Art Heretofore, there has been known a plumbing screw 10 having a fitting groove adapted to a plus screwdriver bit and a minus screwdriver bit, for example, as shown in FIGS. Also,
As a driver bit applicable to such a plastic screw 10, a Phillips screwdriver bit 20 configured as shown in FIG. 8 is used. FIG. 9 shows the fitting state of the plastic screw 10 and the Phillips screwdriver bit 20.

[0003] The plastic screw 10 has an advantage that a conventionally known general screwdriver bit can be used.

[0006] However, the conventional plastic screw 10 shown in FIGS. 6 and 7 is provided with a fitting groove 12 formed of a cross groove in the screw head 10 a. The fitting groove 12 is composed of a pair of straight grooves 12a and 12b crossing each other at the center of the screw head 10a in a cross shape.
“a” is configured to be in contact with the blade portion of the plus driver bit, and the other straight groove 12b is configured to be in contact with the blade portion of the minus driver bit.

The one straight groove 12a is formed as an inclined groove (12a) which is inclined from the edge to the center of the screw neck 10b, and has a gently inclined substantially conical bottom surface 14 at the bottom. Is formed. On both side surfaces of the inclined groove portion 12a, tapered side wall portions 13a each having a taper toward the bottom are formed, and the tapered side wall portions 13a abut and engage with the blade portion of a plus driver bit described later.

The other straight groove 12b is formed to extend as a horizontal groove (12b) having a width and a depth sufficient to be brought into contact with the blade of the flathead screwdriver bit. Then, on both side surfaces of the horizontal groove portion 12b, vertical side wall portions 13b substantially perpendicular to the bottom are formed, and the vertical side wall portions 13b are in contact with and engaged with the blade portions of a well-known minus driver bit.

The one straight groove (inclined groove) 12
a at the corners of the adjacent linear groove (horizontal groove) 12b adjacent to the other linear groove (horizontal groove) 12b.
b is formed, and a part of the blade portion of the driver bit, which will be described later, is also in contact with the tapered coupling surfaces 17a and 17b.

Therefore, the conventional Phillips screwdriver bit 20 shown in FIG. 8 is provided with a blade portion 22 that fits into the fitting groove 12 of the plastic screw 10 and a screw neck from the edge of the fitting groove 12. The extended blade portions 22a are formed to extend so as to conform to the shape of the inclined groove portions 12a extending toward the center of the portion 10b. Reference numeral 23 denotes tapered side wall portions formed on both side surfaces of each blade portion 22 or the extended blade portion 22a.
That is, the tapered side wall portion 23 abuts and engages with the tapered side wall portion 13a formed in the one inclined groove portion 12a of the fitting groove 12 of the plastic screw 10 described above.

According to the conventional combination of the plastic screw and the Phillips screwdriver bit configured as described above, if the plastic screw 10 and the Phillips screwdriver bit 20 are fitted together as shown in FIG. , Each blade portion 22 and the extended blade portion 22a of the Phillips screwdriver bit 20,
Each of the blades 22 is fitted into the fitting groove 12 and
And the tapered side wall part 23 of the extension blade part 22a contacts the tapered side wall part 13a formed in the one inclined groove part 12a of the plastic screw 10. Thus, by turning the Phillips screwdriver bit 20, the plastic screw 1
A predetermined torque can be transmitted to 0. That is, the plastic screw 1 in the required screw mounting object
0 can be attached or detached.

[0010]

However, according to the conventional combination of the plastic screw 10 and the Phillips screwdriver bit 20 having the above-described structure, as shown in FIG. 9, one of the inclined grooves 12a in the screw head 10a. Is
A fixed inclined surface is formed from the edge to the center of the screw neck 10b, while the corresponding Phillips screwdriver bit 20 has a ridge line portion of the extended blade portion 22a and the inclined groove portion 12a. The fitting groove 12 conforms to the shape of
And the ridge portion of the extended blade portion 22a is
It is formed gradually wider toward the rear from the tip. Further, the tapered side wall portion 23 formed on the blade portion 22 of the Phillips screwdriver bit 20 also comes into contact with and engages with the tapered side wall portion 13a formed on the inclined groove portion 12a of the plastic screw 10. When turned in a predetermined direction, the Phillips screwdriver bit 2
0 and the inclined groove portion 12a can be said to be tapered contact on the entire surface.
The leading end of the groove 0 protrudes outward along the inclined surface of the inclined groove portion 12a (indicated by an arrow in FIG. 9), which causes a so-called cam-out phenomenon.

Particularly, as shown in FIG. 7, the shape of the conventional fitting groove of the plastic screw facilitates fitting of the tip blade portion of the driver bit.
For example, the tapered side wall portion 13a formed at a boundary portion or a corner portion between the crossing straight grooves 12a and 12b, which is formed to be relatively larger than the width of the ridge portion of the extension blade portion 22a of the driver bit 20, is formed vertically. The areas of the side wall 13b and the tapered coupling surfaces 17a, 17b are relatively small. Therefore, when the driver bit 20 is rotated, a large amount of stress is applied to the tapered side wall portion 13a, the vertical side wall portion 13b, and the tapered connecting surfaces 17a and 17b. 7 to 1
5, the tapered side wall 13a, the vertical side wall 13b, and the tapered connecting surfaces 17a, 17b are gradually damaged. Therefore, when the damaged portion (the hatched portion 15) is enlarged, the cam-out phenomenon of the driver bit 20 becomes frequent, and finally the screw tightening operation becomes impossible.

From such a viewpoint, in order to prevent the cam-out phenomenon of the driver bit 20, when the driver bit 20 is rotated, a thrust that strongly presses the screw against the bit fitting groove 12 of the screw is applied. Is required. However, there is no problem when the object to which the screw is attached is a rigid body such as a metal, but when it is a precision part or the like, there is a disadvantage that these objects are damaged or broken.

[0013] The occurrence of the above-mentioned come-out phenomenon is as follows.
The wear of the bit tip, that is, the blade portion 22 and the extension blade portion 22a is accelerated, and the wear further promotes the occurrence of the cam-out phenomenon. As a result, the damage of the bit fitting groove 12 of the screw increases.

Further, by applying an excessive thrust to the driver bit 20, it is possible to prevent the cam-out phenomenon, but on the other hand, it is possible to transmit an accurate torque to the screw. However, the magnitude of the thrust applied to the driver bit 20 differs depending on the operator, and as a result, there is a problem that the tightening torque of the screw varies.

Further, in the case of a tapping screw, when the screw is tightened to an object such as a synthetic resin, friction due to thrust is applied in addition to rotational friction of the screw, so that high heat is applied to the object. There is a problem in that the hardness of the screw mounting portion of the object is reduced due to the occurrence, and the loosening of the screw occurs or the object is damaged.

On the other hand, when the screw is manually tightened, the operation of rotating the screwdriver bit 20 while sufficiently pressing it against the screw has a disadvantage that it causes a great deal of labor and fatigue for the operator.

In addition, according to the combination of the conventional plastic screw 10 and the driver bit 20 described above, when the screw is attached using a manual tool or an electric tool, the tip of the bit with respect to the fitting groove of the screw is required. It is difficult to rotate the screw while maintaining the screw shaft and the driver bit shaft coaxially matched during the fitting of the screw shaft. Therefore, when the screw shaft and the driver bit shaft are inclined, In this case, not only the cam-out phenomenon frequently occurs but also the thread groove is frequently damaged.

Further, when removing the screw, the same cam-out phenomenon and the damage of the screw groove as described above are likely to occur, but in this case, the screw cannot be removed.
A situation arises in which a part of the mounting object of the screw must be destroyed. In particular, there is a drawback that when the dust is clogged in the fitting groove of the screw, the above-mentioned situation becomes remarkable. In such a case, it is preferable to use a minus driver bit, but it is troublesome and troublesome to prepare separately from the plus screwdriver bit 20 and use it properly according to the type of work.

Therefore, an object of the present invention is to improve the configuration of the blade tip which can be fitted in the bit fitting groove of the plastic screw, thereby effectively preventing the cam-out phenomenon of the driver bit and improving the screw bit as in the prior art. An object of the present invention is to provide a screwdriver bit for a plastic screw that can prevent damage at the time of attachment / detachment operation, always achieve proper and quick screw attachment / detachment work, and improve work efficiency.

[0020]

In order to achieve the above object, a screwdriver bit for a plastic screw according to the present invention comprises:
A screwdriver bit for a plumbing screw applied to a plumbing screw having a bit fitting groove formed by a pair of straight grooves formed by a pair of straight grooves formed by a slant groove portion and a horizontal groove portion crossing at the center of the screw head; A flat blade portion having an inclined edge portion that fits along the inclined groove portion is provided, and extends at a substantially right angle to intersect at right angles with the flat blade portion and to fit along the horizontal groove portion of the plastic screw. A flat blade portion having a horizontal edge portion formed in contact with a groove bottom surface of the horizontal groove portion, and a projection that fits into a conical bottom surface provided at the center of the screw head of the plastic screw at the center of the tip of each blade portion. It is characterized by being provided.

In this case, the projection formed at the center of the tip of each of the flat blades can be formed into a shape adapted to the groove formed at the center of the bit fitting groove of the plastic screw and the conical bottom surface, respectively. .

The flat blade portion, which extends substantially at right angles to fit along the horizontal groove of the plastic screw and forms a horizontal edge contacting the bottom of the horizontal groove, has a blade width of the horizontal blade. It is preferable that the thickness is formed to be compatible with the groove width of the groove.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a screwdriver bit for a plastic screw according to the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of a screwdriver bit for a plastic screw according to the present invention.
That is, in FIGS. 1 and 2, reference numeral 30 indicates a main part structure of the screwdriver bit for the plastic screw according to the present invention, and the tip of the blade portion of the screwdriver bit 30 for the plastic screw is a conventional one shown in FIGS. At the center of the screw head 10a of the plastic screw 10 in the above, the fitting is formed so as to fit into the bit fitting groove 12 formed by a pair of straight grooves 12a and 12b crossing in a cross shape.

That is, the driver bit 3 of this embodiment
Reference numeral 0 denotes a flat blade portion 32 having an inclined edge portion 33a that is fitted into the bit fitting groove 12 of the screw 10 and engages with an inclined groove formed as one straight groove 12a of the bit fitting groove 12. And a flat blade portion 34 having a horizontal edge portion 35a extending substantially at a right angle and engaging with a horizontal groove portion formed as the other straight groove 12b. In the center of the tip of each of the flat blades 32, 34, a projection 3 having vertical surface portions 33b, 35b fitted into a conical bottom surface 14 provided at the center of the screw head 10a of the plastic screw 10 respectively.
6 is provided. Both side surfaces of the flat blade portions 32, 34 are formed as substantially vertical side wall portions 37, 38, each of which can have a slight taper.

As shown in FIG. 3, the projection 36 projecting from the center of the distal end of each of the flat blades 32, 34 may have an inclined surface 33c, 35c, respectively.

The driver bit 30 of the present embodiment having the above-described structure is provided with the bit fitting groove 12 of the plastic screw 10.
On the other hand, as shown in FIG. 4 and FIG.
2, 34 can be fitted into the respective grooves 12a, 12b.

That is, as shown in FIG. 4A, one of the flat blade portions 32 can be properly fitted into the inclined groove portion 12a which is one straight groove of the bit fitting groove 12. In this case, the inclined edge 33a formed on the flat blade 32 of the driver bit 30 and the projection 36 are fitted into the inclined groove 12a of the plastic screw 10, respectively, and the side wall 37 of the blade 32 and the projection 36 are formed. , Plastic screw 10
Can be brought into contact with the side wall portion 16a of the inclined groove portion 12a. Therefore, by rotating the driver bit 30 in the screw tightening direction, the pruma screw 10 is formed at the contact portion (T1, T2) between the blade portion 32 of the driver bit 30 and the inclined groove portion 12a of the plamai screw 10.
, A predetermined torque transmission can be performed (see FIG. 5).

Further, as shown in FIG. 4B, the other flat blade portion 34 can be properly fitted into the horizontal groove portion 12b which is the other straight groove of the bit fitting groove 12. In this case, the horizontal edge portion 35a and the protrusion 36 formed on the flat blade portion 34 of the driver bit 30 are fitted into the horizontal groove portions 12b of the plastic screw 10, respectively, and the side wall portions 38 of the blade portion 34 and the protrusion 36 are formed. , Plastic screw 10
Can be brought into contact with the side wall 16b of the horizontal groove 12b. Therefore, when the driver bit 30 is rotated in the screw tightening direction, the pruma screw 10 is formed at the contact portion (T3, T4) between the blade portion 34 of the driver bit 30 and the horizontal groove portion 12b of the plamai screw 10.
, A predetermined torque transmission can be performed (see FIG. 5).

Particularly, in this embodiment, FIG.
, The horizontal groove 12b of the plastic screw 10
Of the side wall portion 16b formed on the flat blade portion 34 and the side wall portion 38 of the flat blade portion 34 at the time of driving, the contact area is larger than that of a conventional Phillips screwdriver bit. Therefore, the cam-out phenomenon (see FIG. 9) at the time of the screw tightening operation can be effectively prevented.

Further, in the driver bit 30 of the present embodiment, the driver bit 30 has a taper connection surface 17a, 17b formed at the corner of the linear groove 12a, 12b adjacent to the bit fitting groove 12, respectively. A part of each of the blade portions 32 and 34 abuts and engages to perform sufficient torque transmission, thereby achieving a proper and reliable screw tightening operation.

Further, in the screwdriver bit 30 for a plastic screw according to the present embodiment, each blade 3
Generally, the blade widths (thicknesses) of the blades 2 and 34 are generally the same, but the width of the horizontal groove 12b in the bit fitting groove 12 of the general prama screw 10 is set to be the inclined groove. 12a is designed to be larger than the groove width (see FIG. 5).
Therefore, if the blade width of the blade portion 34 of the driver bit 30 to be fitted into the horizontal groove portion 12b is set to a thick width so as to be compatible with the groove width of the horizontal groove portion 12b, the above-described blade portion 3
A contact portion (T1, T2) between the groove 2 and the inclined groove portion 12a and a contact portion (T3, T4) between the blade portion 34 and the horizontal groove portion 12b are realized at the same time, and the most effective torque transmission is achieved. Can be achieved.

Therefore, according to the screwdriver bit for the plastic screw of the present invention, the same torque transmission as described above can be performed even in the operation of removing the screw opposite to the screw tightening operation described above, and the proper and reliable operation can be achieved. A screw removal operation can be achieved.

The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various design changes can be made without departing from the spirit of the present invention. It is.

[0035]

As is apparent from the above-described embodiment, the screwdriver bit for a plastic screw according to the present invention has a pair of straight grooves formed of an inclined groove and a horizontal groove which cross in a cross shape at the center of the screw head. A flat blade portion formed of a screwdriver bit for a plastic screw that is applied to a plastic screw having a bit fitting groove formed by a flat blade portion having an inclined edge portion fitted along the inclined groove portion of the plastic screw. A flat blade portion extending at a substantially right angle, which intersects the blade portion at right angles and is fitted along the horizontal groove portion of the plastic screw, and forms a horizontal edge portion which comes into contact with the groove bottom surface of the horizontal groove portion; By providing a projection at the center of the tip of the blade that fits into the bottom of the cone provided at the center of the screw head of the plastic screw, the cam-out phenomenon of the driver bit is ensured. It is possible to prevent the.

Further, the screwdriver bit for a plastic screw according to the present invention has a flat blade portion having a substantially horizontal edge portion, which can be engaged with the groove bottom of one of the straight grooves (horizontal groove portion) of the screw. By providing a projection formed so that the tip end of each of the blades conforms to the shape of the conical bottom surface extending from the groove bottom, the most suitable one for the plastic screw can be obtained.

Therefore, in the screwdriver bit for the plastic screw according to the present invention, when the screw is fitted with the screw, the contact abutment area between the side wall at the tip end and the side wall of the bit fitting groove is enlarged, The cam-out phenomenon of the driver bit is almost eliminated, and a proper screw tightening operation and a screw removing operation can be achieved.

Further, according to the screwdriver bit for a plastic screw according to the present invention, when the screw is fitted to the screw, the bit fitting groove may be clogged or the like, or the screw shaft and the bit shaft may be coaxial. Even if it is not above, the rotation of the driver bit is smoothly transmitted to the plastic screw without causing the cam out phenomenon and damage of the screw etc., and the screw tightening operation with the appropriate torque can always be quickly achieved. it can.

That is, if the screwdriver bit for plastic screws according to the present invention is used, it is possible to always perform a reliable screw tightening operation with an appropriate torque on an object to which a screw made of various hard and soft materials is attached. Not only that, breakage of the screw can be significantly reduced, and the safety of the screw tightening operation and the improvement of work efficiency can be easily and economically achieved.

[Brief description of the drawings]

FIG. 1 is a side view of a main part showing an embodiment of a screwdriver bit for plastic screws according to the present invention.

FIG. 2 is a side view of a main part of the screwdriver bit for the plastic screw shown in FIG. 1 as viewed at an angle of 90 ° from the front thereof.

FIG. 3 is a main part side view showing a modification of the screwdriver bit for the plastic screw shown in FIG. 1;

4A is a cross-sectional side view of a main part showing a coupling state of the screwdriver bit for plastic mai screw shown in FIG. 1 and the conventional plastic mai screw shown in FIGS. 6 and 7, and FIG. FIG. 8 is a cross-sectional side view of a main part showing a coupling state between the screwdriver bit and the conventional plastic screw shown in FIGS. 6 and 7.

FIG. 5 is an explanatory plan view of the head of the plastic screw, showing a coupled state of the screwdriver bit for the plastic screw and the plastic screw shown in FIG. 4;

FIG. 6 is a sectional side view of a main part of a conventional plastic screw.

FIG. 7 is a plan view of the head of the plastic screw shown in FIG. 6;

FIG. 8 is a side view of a main part of a conventional Phillips screwdriver bit.

9 is a cross-sectional side view of a main part showing a coupling state between the plastic screw shown in FIG. 6 and the driver bit shown in FIG. 8;

[Explanation of symbols]

 Reference Signs List 10 plastic screw 10a screw head 10b screw neck 12 bit fitting groove 12a straight groove (inclined groove) 12b straight groove (horizontal groove) 13a taper side wall 13b vertical side wall 14 conical bottom surface 16a side wall (of inclined groove 12a) 16b Side wall portion (of horizontal groove portion 12b) 17a, 17b Taper coupling surface 30 Driver bit 32 Flat blade portion 33a Inclined edge portion 33b Vertical surface portion 33c Inclined surface portion 34 Flat edge portion 35a Horizontal edge portion 35b Vertical surface portion 35c Inclined surface portion 36 Projection 37 Side wall (flat blade 32) 38 Side wall (flat blade 34)

Claims (3)

[Claims] 1. A screwdriver bit for a plastic screw which is applied to a plastic screw having a bit fitting groove formed by a pair of straight grooves formed by a pair of inclined grooves and a horizontal groove crossing at the center of the screw head. A flat blade portion having an inclined edge portion that fits along the inclined groove portion of the plastic thread screw, and a substantially right angle crossing the flat blade portion at right angles and fitting along the horizontal groove portion of the plastic thread screw. A flat blade portion which extends horizontally to form a horizontal edge contacting the groove bottom surface of the horizontal groove portion, and a conical bottom surface provided at the center of the tip of each of the blades at the center of the tip of each blade portion A screwdriver bit for a plastic screw which is provided with a projection that fits into a screwdriver. 2. The projection formed at the center of the tip of each flat blade portion has a shape adapted to the groove formed at the center of the bit fitting groove of the plastic screw and the bottom surface of the cone, respectively. Driver bit for plastic screw described. 3. The flat blade portion, which extends substantially at right angles to fit along the horizontal groove of the plastic screw and forms a horizontal edge contacting the groove bottom of the horizontal groove, the blade width of the flat blade is set to the horizontal groove. The screwdriver bit for a plastic screw according to claim 1, wherein the screw bit is formed to have a thickness matching the groove width of the screwdriver.