JPH0572377U - Screw holding device for driver bit - Google Patents

Abstract

(57) [Abstract] [Purpose] In a device for holding a screw formed by forming a circular head portion with a cross-shaped engagement hole in a posture coaxial with a driver bit, Make the structure simple and secure the screwing. [Structure] A head portion B1 of a screw B in a state in which a driver bit 1 is engaged with an engagement portion 1a of the driver bit 1.
The holding cylinder 5 which is fitted to the above is fitted so as to be able to move backward against the spring 6. The head B1 of the screw B is attached to the engaging portion 1a of the driver bit 1 and the ball 8 provided on the holding cylinder 5.
It is clamped by a locking body such as. Since the locking body such as the ball 8 moves radially outward against the elasticity, the head B1 of the screw B can be inserted and removed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a screwdriver bit of a cross type or the like in which a screw having a circular head provided with an engagement hole such as a cross hole is screwed in, without the operator manually holding each screw, The present invention relates to an improvement of a screw holding device which holds a driver bit in a posture that extends coaxially.

[0002]

[Prior Art]

 When screwing a screw with a cruciform driver hole in which the head is formed in a circular shape and a cross-shaped engaging hole is drilled, the head of the screw is formed in a polygonal shape and a box-type driver is used. Unlike the case of screwing with a bit, even if the tip of the driver bit is engaged with the head of the screw, there is a constraint that the screw cannot be held in a posture extending coaxially with the driver bit. Therefore, in order to be able to hold the screw having a cross hole in a posture that extends coaxially with the cross type driver bit, conventionally, a device as shown in FIGS. 13 to 14 has been developed.

That is, in this conventional device, the first tubular body 22 is non-rotatably fitted to a portion near the proximal end of the driver bit 21 that is attached to the driver tool A by means of a screw 23 or the like so that the first tubular body 22 cannot rotate. A second tubular body 24 extending toward the front end direction of the driver bit 21 is slidably and non-removably fitted to the first tubular body 22, and is fitted between the first tubular body 22 and the second tubular body 24. The first spring 25 that elastically supports the backward movement of the second tubular body 24 is inserted.

Further, in the second tubular body 24, the tip end portion 24a has a small diameter which is substantially the same as the outer diameter of the head portion B1 of the screw B, the intermediate portion 24b has a larger diameter, and the base end portion 24c. Is formed to have the largest diameter in three stages, and the third cylinder 26 having a flange 26a formed at an intermediate portion along the axial direction is slid on the tip end portion 24a of the second cylinder 24. It is movably fitted, and the fourth tubular body 27 is screwed into the intermediate portion 24b of the second tubular body 24. The distal end portion of the fourth tubular body 27 is fitted to the distal end portion of the third tubular body 26. The small diameter portion 27a is formed so as to be fitted.

Then, holes 30 are formed at appropriate intervals along the circumferential direction in a portion of the third cylindrical body 26 closer to the tip end than the flange 26 a, and the head of the screw B is inserted into each of these holes 30. The ball 29, which is in contact with the peripheral edge of the seat surface B2 in B1, is fitted inward so as not to come out, while the inner peripheral surface of the third cylinder 27 in contact with each of the balls 29 is connected to the third cylinder. 27 is formed on the tapered surface 28 whose diameter increases toward the rear part of the third cylinder 26, and the third cylinder 26 is advanced between the flange 26a of the third cylinder 26 and the tip surface of the intermediate portion 24b of the second cylinder. A second spring 31 that is biased in the direction is inserted.

That is, in this conventional device, when the third tubular body 26 moves backwards against the second spring 31, each ball 29 can move radially outward along the tapered surface 28. Thus, the outer peripheral portion of the head B1 of the screw B is clamped from the axial direction by the tip surface of the second tubular body 24 and each ball 29 in a state where the engagement and disengagement of each ball 29 with respect to the head B1 of the screw B is allowed. It was done.

Then, by moving the first tubular body 22 forward with the tip of the screw B in contact with the surface of the member C, the engaging portion 21a of the driver bit 21 is engaged with the head portion B1 of the screw B. Then, with the tip of the second tubular body 24 in contact with the surface of the member C, the screw B is axially pressed by the driver bit 21 to utilize the spherical guide action of each ball 29, The heads B1 of the screws B are disengaged from the balls 29 by moving the balls 29 radially outward along the tapered surface 28 of the fourth tubular body 27.

[0008]

[Problems to be solved by the device]

 However, since this conventional device requires four cylinders 22, 24, 26, 27 and two bars 25, 31, there is a problem that the structure is remarkably complicated and the manufacturing cost is increased. .. Further, by rotating the driver bit 21 and moving the driver bit 21 toward the head B1 of the screw B, the engaging portion 21a of the driver bit 21 is fitted into the engaging hole B3 of the head B1 of the screw B. Since they have to be aligned, it was uncertain to fit the engaging portion 21a of the driver bit 21 into the engaging hole B3 of the head portion B1 of the screw B.

Furthermore, since the diameter of the tapered surface 28 of the fourth tubular body 27 decreases toward the tip end of the fourth tubular body 27, the screw B is axially pressed by the driver bit 21. Also, due to the wedge action, each ball 29 is fitted between the fourth tubular body 27 and the third tubular body 26 without moving radially outward, and the head B1 of the screw B is attached to each ball 29. There are many phenomena in which the driver bit 21 becomes incapable of being detached, and this is combined with the uncertain engagement of the driver bit 21 with the head B1 of the screw B as described above. There was a problem that many screwing failures occurred.

An object of the present invention is to provide a screw holding device that solves these problems.

[0011]

[Means for Solving the Problems]

 In order to achieve this object, the present invention provides a driver bit having an engaging portion formed at the tip thereof that fits into an engaging hole of a head portion of a screw, and a head portion of the screw in a state of being engaged with the tip of the driver bit. The holding cylinder to be fitted is fitted so as to be able to move backwards against the spring fitted to the driver bit, and the holding cylinder can be in a state of being engaged with the driver bit. The locking body, which is designed to abut a plurality of points along the circumferential direction on the periphery of the, should be moved radially outward against the elasticity by inserting and removing the screw head into the holding cylinder. It is configured to be provided.

[0012]

[Operation and effect of the device]

 In this configuration, when the head of the screw is inserted into the holding cylinder and the locking body is moved radially outward against the elasticity, the head of the screw is engaged with the tip of the driver bit. Since the locking body contacts the peripheral edge of the seat surface of the head of the screw and the screw head is sandwiched between the driver bit and each locking body, the screw is coaxial with the driver bit. Is held in a posture that extends to.

When the front end surface of the holding cylinder comes into contact with the surface of the fastening member during screwing, the holding cylinder and the driver bit move relative to each other, and the locking body moves outward in the radius during that time. By doing so, the head of the screw is disengaged from the locking body. In the present invention, the driver bit serves as a member for holding the posture of the screw B. Therefore, only the holding cylinder is sufficient as the movable member that moves relative to the driver bit, and the spring that is fitted on the driver bit is used. However, only one is required to elastically support the backward movement of the holding cylinder. Therefore, the number of parts can be greatly reduced and the structure can be remarkably simplified compared with the conventional one. Manufacturing costs can be reduced.

Further, since the driver bit is pre-engaged with the head of the screw, it is possible to reliably rotate the screw by the driver bit. The locking body for the head moves only outward in the radial direction, and the screw head pressing force can reliably separate the head of the screw from the locking body. Can be reliably performed.

[0015]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings (FIGS. 1 to 12). FIG. 1 to FIG. 7 show the first embodiment. In these figures, reference numeral 1 indicates a driver bit, and the driver bit 1 has a cross-shaped engaging portion 1a at its tip and a driver bit 1 at its base end. Each mounting portion 1b for the driver tool A is formed.

A fixed cylinder 2 is fitted to a portion near the base end of the driver bit 1 and is fixed non-rotatably by a set screw 3, and the fixed cylinder 2 is attached to the fixed cylinder 2 in the tip direction of the driver bit 1. A guide cylinder 4 extending in the direction is fixed, and a holding cylinder 5 fitted to the head B1 of the screw B in the state of being engaged with the driver bit 1 is slidable and cannot be removed. A coil-shaped spring 6 to be fitted to the driver bit 1 is inserted between the base end surface of the holding cylinder 5 and the tip end surface of the fixed cylinder body 2 by inserting.

Through holes 7 radially extending in the radial direction are formed at three portions of the holding cylinder 5 near the tip end along the circumferential direction, and the screws B are respectively attached to the through holes 7. A ball 8 made of steel or the like, which is an example of a locking body for the seat surface B2 of the head B1 in the head B1, is fitted into the holding cylinder 5 so as not to be pulled inward in the radius and movably outward in the radius. Further, an annular groove 9 is formed on the outer peripheral surface of the holding cylinder 5 so as to communicate with each of the through holes 7, and each ball 8 is biased inwardly in the annular groove 9. Fit the elastic ring 10 '. A cap 11 for closing the annular groove 9 is attached to the holding cylinder 5 by screwing or press fitting.

In the above-mentioned structure, when the shaft portion B4 of the screw B is picked by hand and the head portion B1 is inserted into the holding cylinder 5 while rotating lightly, the balls 8 of the elastic ring 10 'are moved. The head B1 of the screw B is engaged with the engaging portion 1a of the driver bit 1 by moving outwardly against the elasticity, and at the same time, each ball 8 is moved by the elastic force of the elastic ring 10 '. The balls B move back inward by a half radius and elastically abut on the peripheral edge of the seat surface B2 of the head B1 of the screw B, so that the screw B is placed in a posture extending coaxially with the driver bit 1. Retained.

The screw B can be screwed into the member C by pressing the screw B toward the member C while rotating the driver bit 1 by driving the driver tool A. In this screwing operation, the holding cylinder 5 rotates together with the driver bit 1 until it comes into contact with the surface of the member C, and when it comes into contact with the surface of the member C, the rotation stops due to friction with the member C, or The rotation speed decreases, and in that state, the driver bit 1 and the fixed cylindrical body 2 move forward against the spring 6 and the head portion B1 of the screw B presses each ball 8 outward in the radius direction. By doing so, the head B1 of the screw B is separated from each ball 8.

The holding cylinder 5 does not necessarily have to be fitted into the guide cylinder 4, but may be directly slidably fitted onto the driver bit 1 so as not to come off, and the fixed cylinder 2 may be fitted. Also, one end of the spring 6 may be directly supported by the driver tool A without providing the guide cylinder 4. 8 and 9 show a second embodiment in which an elastic O-ring 10 is used as the locking body.

That is, in this embodiment, when the O-ring 10 is fitted into the annular groove 9 engraved at the tip of the holding cylinder 5, linear shapes are formed at a plurality of positions along the circumferential direction of the annular groove 9. A plurality of O-rings 10 along the circumferential direction are formed by forming notches 9a of the O-ring 10 so that the annular groove 9 communicates with the inside of the holding tube 5 at a plurality of locations along the circumferential direction. Is exposed inside the holding cylinder 5, and the inwardly exposed portion 10a of the O-ring 10 is brought into contact with the peripheral edge of the seat surface B2 of the head B1 of the screw B.

The configuration of the second embodiment has an advantage that the structure can be simplified. In the third embodiment shown in FIG. 10, when the ball 8 is used as the locking body as in the first embodiment, an elastic plate such as a leaf spring is used as a means for biasing the ball 8 radially inward. 12 is formed in a substantially C shape and is fitted in the annular groove 9. It goes without saying that various other means such as a coil spring can be adopted as the means for urging the locking body such as the ball 8 inward in the radius.

In a fourth embodiment shown in FIG. 11, a piece body 13 as an example of a locking body cannot be pulled out radially inwardly in a through hole 7 formed in a plurality of positions in a holding cylinder 5 and cannot be pulled out radially outward. A conical portion 13a, which is movably fitted and has a diameter reduced inward in the radial direction, is formed at a portion of each top member 13 that protrudes into the holding cylinder 5, and the conical portion 13a is connected to the driver bit. The peripheral edge of the seat surface B2 of the head portion B1 of the screw B in the state of being engaged with 1 and the outer peripheral surface of the shaft portion B4 are brought into contact with each other.

In this case, the top body 13 easily moves outward in the radius by the insertion / removal of the head B1 of the screw B by the guide action of the conical portion 13a, which impairs the reliable screwing work. There is no. The fifth embodiment shown in FIG. 12 is an embodiment in which a claw piece 14 made of a leaf spring is used as a locking body, and is provided at a plurality of portions of the inner peripheral surface of the holding cylinder 5 along the circumferential direction. The base end portion of the claw piece 14 whose tip is bent in a cross section is fixed, and the head portion B1 and the shaft portion B4 of the screw B are clamped by each claw piece 14. ..

As is clear from the fifth embodiment and the second embodiment, in the case where the locking body has a structure such as the claw piece 14 and the O-ring 10 which itself has elasticity, the screw B The part that contacts the head B 1 of the vehicle moves radially outward, but “movable” described in the scope of the utility model registration request means that a part of the locking body is as described above. This includes the case of moving outward in the radius.

Although each of the above-described embodiments has been applied to a cross-shaped driver bit, the present invention can also be applied to a minus-type driver bit or a polygonal driver bit such as a hexagon wrench. Needless to say. Further, it goes without saying that the present invention can be applied not only to a driver bit that is attached to a driver tool, but also to a manually-operated driver bit or a driver bit used in an automatic assembly process of various machines.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a first embodiment.

FIG. 2 is a side view of the first embodiment.

FIG. 3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

5 is a cross-sectional view taken along line VV of FIG.

FIG. 6 is an enlarged sectional view of a holding cylinder.

FIG. 7 is a sectional view taken along line VII-VII of FIGS. 1 and 6.

FIG. 8 is a sectional view showing a second embodiment.

9 is a plan view of FIG. 8. FIG.

FIG. 10 is a perspective view of an essential part showing a third embodiment.

FIG. 11 is a cross-sectional view of essential parts showing a fourth embodiment.

FIG. 12 is a sectional view of an essential part showing a fifth embodiment.

FIG. 13 is a diagram showing a conventional technique.

14 is a sectional view taken along line XIV-XIV in FIG.

[Simple explanation of symbols]

 A driver tool B screw B1 screw head B2 head seat surface C member 1 driver bit 1a engaging part 2 fixed cylinder body 4 guide cylinder 5 holding cylinder 6 spring 7 through hole 8 ball as an example of a locking body 9 Annular groove 10 O-ring made of an elastic body as an example of a locking body 13 Top body as an example of a locking body 14 Claw piece as an example of a locking body

Claims (1)

[Scope of utility model registration request] 1. A holding cylinder which is fitted to a screw head in a state of being engaged with a tip of the driver bit, in a driver bit having an engagement portion formed at a tip thereof to be fitted into an engagement hole of a head portion of the screw. Is fitted to the driver bit so as to be able to retreat against the spring fitted to the driver bit, and the holding cylinder is fitted with a portion of the periphery of the seat surface of the head of the screw in the state of being engaged with the driver bit. A locking body that comes into contact with multiple points along the circumferential direction is provided so as to move outward in the radial direction against elasticity by inserting / removing the screw head into / from the holding cylinder. A screw holding device for a characteristic driver bit.