JPH07328947A - Torque adjustment tool - Google Patents

Abstract

PURPOSE: To reduce unevenness of release torque and facilitate recalibration by depressing a ball when a force is applied in the direction opposite to a first direction and forming a locking mechanism by cooperation of an opening to give undirectional torque adjustment characteristic to a tool. CONSTITUTION: When torque is applied in the direction of screw tightening while a ball 24 is in a recessed zone 15 of a head 13, a guide part 7 moves relatively in the direction of arrow mark F1. The ball 24 is pressed by a vertical face 22, is subjected to a force of a spring 27 through a horizontal plate 25, and hits against an inclined face 17. As far as torque to be applied on a drive element 2 is less than a threshold value, the head 13 is rotated and an element to be driven 3 is rotated by this torque. When torque reaches the threshold value, the ball 24 compresses the spring 27, rises on the inclined face 17, moves onto a plane zone 14, and drops again in the next zone 15. In case of reverse rotation, the ball 24 hits against a vertical face 18 and is locked between an overhang face 23 of the guide part 7 and it to transmit torque directly to the element to be driven 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention comprises a drive element and a driven element connected by a torque adjusting joint, the joint being integral with one of the two elements and having a groove with at least one recess. A guide part having one opening and integral with the other element, and a sphere which is received in this opening and is moved towards the groove, said recess having a ramp on one side and in a first direction It relates to a torque adjusting tool of the type in which a sphere rises up a ramp when the force applied to it reaches a predetermined value, in particular a torque adjusting screwdriver.

[0002]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a torque adjustment tool which can economically reduce variations in release torque and greatly facilitate recalibration.

Therefore, according to the present invention, when a force is applied in a direction opposite to the first direction, the end of the recess and the end of the opening that cooperate with the ball form a locking mechanism together with the ball. SUMMARY OF THE INVENTION It is an object of the invention to provide a torque control tool of the type mentioned above, characterized in that it provides the tool with a one-way torque control characteristic.

[0004]

The tool can have one or more of the following features.

The said recess at the end is a plane perpendicular to the direction of relative movement between the groove wheel and the guide part.

The said end of the opening projects against the groove ring.

The said end of the opening has an arcuate cross section.

The radius of the arc is slightly larger than the radius of the sphere.

The opening extends in the direction of relative movement between the groove wheel and the guide part.

The elastic stress of the sphere is adjustable.

The torque adjustment tool according to the invention can in particular be constructed as a one-way torque adjustment screwdriver.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, the general axis X--X located vertically
A torque adjusting screwdriver 1 indicated by 1 comprises a generally tubular drive element 2 and a cutterhead-shaped driven element 3.

The drive element 2 comprises an upper part 4 and a lower part 5 separated by an inner collar 6. Underneath this internal collar, many parts integral with the element 2 are fitted in order from top to bottom. An inverted cup-shaped ball guide part 7, an upper bearing 8, an adapter sleeve 9, a lower bearing 10 and an annular support part 11 screwed into the threaded inner end of the element 2.

The upper part of the cutter head is the parts 8 to 11
It is integrated with the inner ring of the two bearings 8, 10 received therein and free to rotate about the axis X-X. The lower part of the cutter head projects below the element 2.

A threaded blind hole is provided in the upper surface of the cutter head 3 and a threaded rod 12 provided at the upper end of the wide cutter head is provided in this blind hole so as to interlock with the rotation of the cutter head. It is screwed. Head 13
The upper surface of FIG. 6 forms a groove ring containing three flat, horizontal zones 14 separated by three recessed zones 15 which are spaced at an angle of 120 ° from each other, as can be seen in FIGS. That is, each recess 15 has a flat, horizontal bottom 16 which is connected to the zone 14 by an inclined surface 17 inclined at 45 ° on one side and a vertical radial surface 18 on the other side. There is.

As can be better seen in FIGS. 2 and 3, the bottom part 19 of the guide piece 7 is surrounded by 120 around each other.
It has three elongated openings 20 spaced at an angle of °. Each opening 20 is defined on the side by two cylindrical surfaces 21 about the axis XX, by a cylindrical surface 22 on one end and a spherical surface 23 on the other end, all of which are in contact with one another in the connecting direction. . Surfaces 22 and 23 have the same radius of curvature, and the angular spacing of their centers is 2 for a given aperture 20.
It is about 0 °.

A sphere 24 having a radius slightly smaller than the radius of curvature of the faces 22, 23 is received in the opening 20 by the face 21, but guided in a wide circumferential gap, and rests on the upper faces 14, 15 of the head 13. . The three balls 24 are pushed downwards by a horizontal plate 25 which can move past the collar 6 with a wide gap. This horizontal plate 25 is used for the compression coil spring 2
With the push plate 26 with 7, the push plate 26 and the horizontal plate 25
It is pushed downwards via a ball 28 which is received in a conical cutout facing the center of the. The force of the spring 27 can be adjusted by a conventional mechanism (not shown) associated with the top of the drive element 2.

Next, the function of the screwdriver 1 will be described with reference to FIGS. 6 to 13. In these figures, elements 26 and 28 have been omitted for clarity. First, the ball 24 is head 1
Suppose it is in a recessed zone 15 of 3.

When the user applies a torque in the tightening direction of the screw, which corresponds to the movement of the guide part 7 in the direction of the arrow F in FIGS. 6 to 11, the sphere 24 is pushed by the vertical surface 22 and the spring While being pushed downward through the horizontal plate 25 by a predetermined force of 27, it strikes the inclined surface 17.

As long as the torque on the drive element remains below a certain threshold, this torque causes the head 13 and thus the driven element 3 to rotate.

When the threshold value is reached, the ball 24 rises on the inclined surface 17 by the action of the cam while compressing the spring 27 (FIG. 7) and then rolls over the plane zone 14 practically unobtrusively (FIG. 8, 9) and then falls again into the next zone 15 (Figs. 10, 11). Therefore, the threshold cannot be exceeded.

On the contrary, when torque is applied in the opposite direction, that is, in the direction in which the screw is loosened with respect to the element 2, (FIG. 12, 1)
3, arrow F1), the sphere 24 is pushed by the surface 23 which overhangs the vertical surface 18. The design of these surfaces is such that locking occurs (Fig. 13). The torque is therefore transferred directly to the driven element, whatever its value, within the limits of the mechanical resistance of the component.

[0024]

It can be seen that this screwdriver has a one-way torque adjustment characteristic. This is a great advantage. This is because the torque limit is usually only needed when tightening a screw, but on the other hand a much stronger torque is applied to loosen the screw, as if trying to force a stuck screw. Because it is generally desirable. Therefore, the machining advantages over conventional bidirectional torque adjusting screwdrivers are not offset by the inconvenient reality for the user.

Furthermore, it is much easier to guarantee the adjusting torque in only one direction with high accuracy, and the recalibration can be done more quickly.

As a variant, the longitudinal cross-section of the protruding surface 23 can be straight (FIG. 4) or stepped (FIG. 5), and the surface 18 can be provided with another structure in which the above-mentioned locking effect can be obtained. You can also

[Brief description of drawings]

FIG. 1 is a partial view showing an axial cross section of a torque adjusting screwdriver according to the present invention.

2 is an enlarged view of the ball guide component of the screwdriver as seen from below along the plane II-II of FIG.

FIG. 3 is a partial cross-sectional view of the ball guide component taken along the line III-III in FIG.

FIG. 4 is a view similar to FIG. 3 showing a first modification.

FIG. 5 is a view similar to FIG. 3 showing a second modification.

FIG. 6 is a first partial cross-sectional view of a screwdriver showing the function of this tool.

FIG. 7 is a second partial sectional view of the screwdriver showing the function of this tool.

FIG. 8 is a third view of a partial cross section of a screwdriver showing the function of this tool.

FIG. 9 is a fourth view of a partial cross section of the screwdriver, showing the function of this tool.

FIG. 10 is a fifth view of a partial cross section of a screwdriver showing the function of this tool.

FIG. 11 is a sixth view of a partial cross section of a screwdriver showing the function of this tool.

FIG. 12 is a seventh view of a partial cross section of a screwdriver showing the function of this tool.

FIG. 13 is an eighth view of a partial cross section of a screwdriver showing the function of this tool.

[Explanation of symbols]

 1 Torque adjusting screwdriver 2 Driving element 3 Driven element 4 Upper part of driving element 5 Lower part of driving element 6 Inner collar 7 Ball guide component 8 Upper bearing 9 Adapter sleeve 10 Lower bearing 11 Annular support component 12 Rod 13 Head 14 Horizontal zone 15 recess 16 horizontal bottom 17 inclined surface 18 vertical radial surface 19 guide part bottom 20 elongated opening 21 cylindrical surface 22 cylindrical surface 23 spherical surface 24 ball 25 horizontal plate 26 push plate 27 compression coil spring 28 ball

Claims (8)

[Claims] 1. A drive element (2) and a driven element (3) connected by a torque adjusting joint, the joint having at least one recess (15) integral with one of the two elements. Grooves (14), (15), a guide piece (7) having at least one opening (20) and integral with the other element (2), 1 received in this opening and moved towards the groove And a sphere (24), the recess having an inclined portion (17) on one side, and the sphere (24) moves up the inclined portion when the force applied in the first direction (F) reaches a predetermined value. In the torque adjusting tool, the first direction F
When a force is applied in the opposite direction (F1) to the sphere (24)
The end (18, of the recess (15) and the opening (20) cooperating with
23) A torque adjustment tool, characterized in that 23) forms a locking mechanism with the sphere, thereby giving the tool a unidirectional torque adjustment characteristic. 2. The end (18) of the recess (15) is a surface perpendicular to the direction of relative movement between the groove wheel (14, 15) and the guide part (7). The torque adjustment tool described in. 3. Torque adjustment tool according to claim 1 or 2, characterized in that the end (23) of the opening (20) projects against the groove wheels (14, 15). 4. Torque adjusting tool according to claim 3, characterized in that the end (23) of the opening (20) has an arcuate cross section. 5. Torque adjusting tool according to claim 4, characterized in that the radius of the arc (23) is slightly larger than the radius of the sphere (24). 6. Torque adjusting tool according to claim 1, characterized in that the opening (20) extends in the direction of relative movement between the groove wheel (14, 15) and the guide piece 7. . 7. Torque adjusting tool according to claim 1, characterized in that the elastic stress of the sphere (24) is adjustable. 8. The torque adjusting tool according to claim 1, wherein the torque adjusting tool is constituted by a one-way torque adjusting screwdriver.