EP2907622B1 - Screwing device and screwing tool including such a device - Google Patents

Description

The present invention relates to the field of tools, and more specifically to screwing tools. It relates more particularly to a device for screwing, on a support, a free nut mounted at the end of a fluid supply conduit.

The ducts are present in different mechanisms, they are particularly intended to ensure the circulation of a fluid (liquid or gas). In the automotive field, mechanical devices such as engines and gearboxes require the connection of conduits in order to circulate oil or fuel. These pipes can be subjected to high temperatures or high pressures depending on the conditions of use in which they evolve, and must therefore be properly connected.

For its connection, a duct is generally provided, at one free end, with a free nut both in rotation and in translation, the nut being held on the duct by a bulge or collar formed at the end of that -this.

• un guide muni d'une paire de doigts aptes à venir enserrer le conduit ;
• un organe de vissage monté en rotation par rapport au guide, propre à coopérer avec l'écrou pour entraîner celui-ci en rotation.

Such a nut usually has an internal thread - or an external thread, depending on the complementary shape (thread or, respectively, tapping) present on the support. The assembly can be done manually by means of wrench (wrench, flat wrench). Such manual editing is long and tedious, and it has been imagined (see document FR 2 946 556 ) automate it in part using a tool including an electric screwdriver and a device comprising:

• a guide provided with a pair of fingers able to grip the duct;
• a screwing member rotatably mounted relative to the guide, adapted to cooperate with the nut to drive it in rotation.

The screwing member is in the form of a fingerprint provided with an opening. The impression is rotated about a first axis, and the guide along a second axis collinear with the first axis. In use, the nut is first screwed by hand on its connector, but not yet tightened. The tool is first placed in a open configuration in which a mouth of the guide is open in the direction of the opening of the cavity. The conduit is introduced radially into the tool through the opening. Then, once the conduit in the cavity, the tool is translated axially along the tube to introduce the nut into the cavity. The guide is moved a quarter of a turn to a locking position to prevent withdrawal of the conduit. Then the impression is rotated to ensure the screwing of the nut on its connector.

This solution represents a progress compared to a manual assembly, but it remains perfectible.

Indeed, if the introduction of the conduit in the tool is without difficulty, however the introduction of the nut in the cavity is difficult because it is performed blind. The operator must therefore fumble before being certain that the nut is properly inserted into the cavity. This groping is usually done in conditions of access and difficult positioning, it results in a waste of time.

In addition, the tool is only provided for a single size of nut, which supposes the provision of the operator of a range of tools equipped with fingerprints of different sizes, to the detriment of the ergonomics of the workstation.

A first objective is to propose a screwing tool capable of performing the screwing operation quickly, regardless of the working conditions.

A second objective is to propose a tool provided with an adapter that can be used on a standard screwdriver.

For this purpose, it is proposed, in the first place, a device for screwing a nut for fixing a conduit on a support according to claim 1.

This device therefore allows to screw the nut on the support by friction on an upper face thereof. The positioning of the roller on the nut is quick and easy. The nut can thus be quickly screwed onto the support, and the screwing can then be completed by a manual tightening operation by means of a wrench with which the final tightening torque can be controlled.

• le guide comprend un corps à partir duquel chaque doigt s'étend en saillie, ce corps étant percé d'un alésage pour le passage du galet ;
• chaque doigt présente une section longitudinale qui s'étend à partir du corps, et une section coudée qui prolonge transversalement la section longitudinale ;
• le galet est monté en rotation autour d'un axe parallèle à la section longitudinale des doigts ;
• le dispositif comprend un embout sur lequel est monté le galet, cet embout étant muni d'une queue propre à venir se loger dans une empreinte complémentaire formée à une extrémité d'un arbre moteur d'une visseuse ;
• l'embout est pourvu d'une tête filetée, et le galet est pourvu d'un alésage taraudé par lequel le galet peut être fixé sur l'embout par vissage sur la tête filetée ;
• le dispositif comprend un adaptateur par lequel le dispositif peut être fixé sur une visseuse ;
• la surface périphérique du galet est élastique ;
• le galet est réalisé dans un matériau élastique.

Various additional features may be provided, alone or in combination:

• the guide comprises a body from which each finger extends in projection, this body being pierced with a bore for the passage of the roller;
• each finger has a longitudinal section extending from the body, and a bent section which extends transversely the longitudinal section;
• the roller is rotatably mounted about an axis parallel to the longitudinal section of the fingers;
• the device comprises a nozzle on which is mounted the roller, this nozzle being provided with a tail adapted to be housed in a complementary cavity formed at one end of a motor shaft of a screwdriver;
• the tip is provided with a threaded head, and the roller is provided with a threaded bore through which the roller can be fixed on the tip by screwing on the threaded head;
• the device comprises an adapter through which the device can be attached to a screwdriver;
• the peripheral surface of the roller is elastic;
• the roller is made of an elastic material.

It is proposed, secondly, a screwing tool comprising a screwdriver provided with a motor shaft, and a device as presented above mounted on the screwdriver with the roller made integral in rotation with the motor shaft.

• la figure 1 est une vue en perspective éclatée montrant un système de vissage comprenant une visseuse et un dispositif de vissage apte à être monté sur la visseuse ;
• la figure 2 est une vue en perspective éclatée montrant le dispositif de vissage de la figure 1, à échelle agrandie, selon l'encart II ;
• la figure 3 est une vue en coupe longitudinale du dispositif de vissage de la figure 1 ;
• la figure 4 est une vue en perspective illustrant une utilisation du système de vissage de la figure 1, avec en médaillon un détail à échelle agrandie ;
• la figure 5 est une vue de détail en coupe du dispositif de la figure 4, selon le plan de coupe V-V ;
• la figure 6 est une vue de détail en coupe du dispositif de la figure 4, selon le plan de coupe VI-VI de la figure 5.

Other objects and advantages of the invention will become apparent in the light of the description of an embodiment, given hereinafter with reference to the accompanying drawings, in which:

• the figure 1 is an exploded perspective view showing a screwing system comprising a screwdriver and a screwing device adapted to be mounted on the screwdriver;
• the figure 2 is an exploded perspective view showing the screwing device of the figure 1 on an enlarged scale, according to box II;
• the figure 3 is a longitudinal sectional view of the screwing device of the figure 1 ;
• the figure 4 is a perspective view illustrating a use of the screwing system of the figure 1 , with a medallion detail on an enlarged scale;
• the figure 5 is a detail view in section of the device of the figure 4 , according to the VV cutting plane;
• the figure 6 is a detail view in section of the device of the figure 4 , according to section VI-VI of the figure 5 .

On the figure 1 1 is a screwdriving tool comprising a screwdriver 2 and a screwing device 3 mounted on the screwdriver 2.

The screwing device 3 is designed to allow the screwing of a nut 4 mounted free in translation and in rotation on a fluidic feed pipe 5 intended to be connected to a support 6, as shown in FIG. figure 4 .

More specifically, the duct 5 has, at one end, a bulge 7 forming a stop for the nut 4. It has a threaded skirt 8 (or threaded) to allow its screwing on a complementary fitting 9 (threaded or, respectively threaded) formed protruding from the support 6. In the example illustrated, the skirt 8 of the nut 4 is internally threaded, and has a standard hexagonal profile 10 on the outside. The screwing of the nut 4 on the connector 9 causes the tight cooperation of the bulge 7 with it. The skirt 8 is extended by a neck 11 provided with a bore 12 through which the nut 4 can freely slide on the conduit 5. The neck 11 has, opposite the skirt, a flat upper face 13 surrounding the piercing 12.

The screwdriver 2 comprises a handle 14 and a casing 15 housing an electric motor driving around an axis R of rotation a motor shaft 16 at one end of which is formed a footprint 17 clean to accommodate a range of tips (typically hexagonal tail).

According to a particular embodiment illustrated on the figures 1 and 4 , the screwdriver 2 is of the electric screwdriver type, the handle 14 being mounted hinged relative to the casing 15, between a gun position (in dashed line on the figure 1 ) and a screwdriver position (solid line on the figure 1 ).

In a conventional manner, a trigger (not visible in the figures) is mounted on the handle 14 to control the rotation of the motor shaft 16. Similarly, the screwdriver 2 can usually be equipped with an inverter to select the direction of rotation of the motor shaft 16 (clockwise or counterclockwise).

Different manufacturers (including Bosch, Makita, Hitachi, DeWalt) offer this type of screwdriver. For example, the DF010 model marketed by the Makita company is suitable here.

The screwing device 3 comprises a guide 18 and a screwing member 19 rotatably mounted relative to the guide 18, in the form of a roller 19 having a cylindrical peripheral surface 20 having a high coefficient of friction for driving the nut 4 by friction. this peripheral surface 20 against the upper face 13 of the nut 4. The peripheral surface 20 is symmetrical in revolution about a central axis X of the roller.

As can be seen from the figure 2 , the guide 18 comprises a pair of fingers 21 adapted to grip the duct 5 to guide the screwdriver 2 during screwing of the nut 4 on the connector 9, as will be explained below.

More specifically, the guide 18 comprises a substantially cylindrical body 22, pierced with a central bore 23 for the passage of the roller 19. Each finger 21 has a longitudinal section 24 which projects from a front face 25 body 22, and a bent section 26 which extends transversely longitudinal section 24. The bent sections 26 have internal facing faces 27 which, when the guide 18 is mounted on the conduit 5, enclose it.

According to a particular embodiment, the spacing between the fingers 21 is fixed, the guide 18 being interchangeable to fit 5. Alternatively (not shown), the fingers 21 are adjustable in spacing, in the manner of a clamp.

As can be seen from the figure 5 , the guide 18 comprises a housing 28 formed between the fingers 21 to accommodate the roller 19 when the device 3 is mounted on the screwdriver 2 (in practice, the housing 28 extends in the axial extension of the bore 23). In this position, the roller 19 is in the immediate vicinity (that is to say at a distance of between a few tenths of millimeters and a few millimeters at most) of a rear face 29 of the bent sections 26.

According to an embodiment illustrated in the figures, the screwing device 3 furthermore comprises a fitting end 30 on which the roller 19 is intended to be fixed, the end piece 30 being itself intended to come into position. fit in the footprint 17 of the screwdriver 2.

In the illustrated example, the endpiece 30 comprises a standard shank 31 with hexagonal section, with a groove 32 intended to cooperate with balls of a mechanism (not shown) for axial locking integrated in the screwdriver 2.

The tip 30 comprises, at a front end of the tail 31, a flange 33 and projecting from the flange 33, a threaded head 34. The roller 19 is, in turn, provided with a threaded bore 35 by which the roller 19 is intended to be fixed on the tip 30 by screwing on the threaded head 34, as shown in FIGS. Figures 5 and 6 . In the screwed position of the roller 19, it is in abutment against the flange 33. For use in screwing (clockwise direction of rotation), the pitch of the thread of the head 34 and the tapping of the bore 35 is on the right, so that the clockwise rotation of the endpiece tends to tighten the roller 19 against the flange 33. For use in unscrewing, it will be advantageous to use a thread and a tapping, the pitch is on the left, so as to tighten the roller 19 against the flange 33 during the counterclockwise rotation of the tip 30.

According to a preferred embodiment, the screwing device 3 is provided with removable fixing means on the screwdriver 2, to allow the replacement of the roller 19 and / or the change of guide 18 (according to the diameter of the duct 5).

In the illustrated example, the screwing device 3 comprises an adapter 36 through which the device 3 can be fixed on the screwdriver 2.

This adapter 36 comprises a barrel 37 complementary to a front end of the housing 15 of the screwdriver 2, on which it is thus adapted to be fitted. In the example illustrated, the drum 37 is provided with lateral notches 38 which are positioned on either side of beads 39 formed on the casing 15. The attachment of the adapter 36 to the casing 15 may be effected at means of screws 40 which come, through openings 41 formed in the drum 37, to be taken in holes 42 drilled radially in the housing 15.

As illustrated on the figure 2 , the adapter 36 is provided, at a front end, with a sleeve 43 on which the body 22 of the guide 18 can be fitted, the fixing of the guide 18 on the adapter 36 being for example made by means of screws 44 that come, through openings 45 formed in the body 22, to take in holes 46 radially drilled in the sleeve 43.

The adapter 36 can be mounted permanently on the housing 15 of the screwdriver 2, since it is not necessary to disassemble it to replace the endpiece 30, the roller 19 or the guide 18.

The mounting of the roller 19 on the tip 30 is by screwing, until the roller 19 is in abutment against the collar 33. The unscrewing (for example when the roller 19 is worn) is by the reverse movement.

Once the roller 19 mounted on the tip 30, it is fitted into the cavity 17 of the motor shaft 16 of the screwdriver 2. In this position, the axis R of rotation of the screwdriver 2 and the X axis of symmetry of the roller 19 are merged.

Once the tip 30 in place, the guide 18 is mounted on the adapter 36, and fixed on it with the screws 44. In this position, illustrated on the Figures 4 to 6 , the guide 18 is integral (without any degree of freedom) of the housing 15, and the roller 19 is integral in rotation with the motor shaft 16 of the screwdriver 2, so that the rotation of the motor shaft 16 around its axis R integrally drives the rotation of the roller 19 about its axis X of symmetry, the latter being itself parallel to the longitudinal section 24 of the fingers 21.

According to a preferred embodiment, the peripheral surface of the roller 19 is elastic. The remainder of the roller 19 may be rigid. In this case, the roller 19 may be bi-material, and comprise a core made of a rigid material (such as steel or aluminum), and a peripheral strip of elastomer. However, according to another embodiment, which corresponds to the illustrated example, the roller 19 is monobloc and is made in this case in a single elastic material, such as a natural or synthetic elastomer (such as rubber).

In operation, it begins by manually position the conduit 5 on the support 6 by putting the nut 4 in helical engagement with the connector 9, so as to ensure their co-axial. It is not necessary to make several turns: it is enough that the nut 4 can not rock.

Then the guide 18 is positioned on the duct 5, in the immediate vicinity of the nut 4, so that the peripheral surface 20 of the roller 19 is in contact with the upper face 13 of the nut 4.

It then suffices to control the rotation of the motor shaft 16, which causes, via the end piece 30, the roller 19 in rotation about its axis X (arrow F1, medallion of detail of the figure 3 ). The friction of the peripheral surface with the upper face 13 of the nut 4 drives it, in the manner of a gear, in rotation around the duct 5 and ensures its screwing on the connection 9 (arrow F2).

It is not necessary to continue the screwing until a large tightening of the nut 4 on the connector 9, because the appreciation of the tightening torque through a screwdriver is bad. The operator therefore has the advantage, when he finds that the roller 19 is slipping, rather than increasing the support force, stopping the screwdriver 2, removing the guide 18 from the conduit 5 and completing the screwing by means of a mechanical tool such as a wrench or a wrench, by which it can, for a few degrees, finely adjust the tightening torque of the nut 4 on the connection 9.

This device 3 therefore allows the nut 4 to be screwed onto the support by friction, on an upper face thereof. The positioning of the roller 19 on the nut 4 is simple and fast. The nut 4 can thus be quickly screwed onto the support 6, and the screwing can then be completed by a manual tightening operation using a key (which can be dynamometric) thanks to which it is possible to control (judged or by measure) the final tightening torque.

The screwing device 3 which has just been described provides several advantages.

First, it allows a fast and reliable screwing operation whatever the working conditions, since the screwing is achieved by only contact of the roller 19 with the upper face 13 of the nut.

Secondly, the structure of the screwing device 3 allows it to be adaptable on commercial screwdriver models, for the benefit of the interchangeability of parts.

Claims (10)

1. A screwing device (3) of a securing nut (4) of a duct (5) on a support (6), this device (3) including:

   - a guide (18) provided with a pair of fingers (21) able to come to grip the duct (5);

   - a screwing element (19) mounted in rotation with respect to the guide (18), suited to cooperate with the nut (4) to drive the latter in rotation;

   this device (3) being characterized in that:

   - the screwing element (19) is present in the form of a roller (19) having a peripheral surface (20) with a sufficient coefficient of friction to drive the nut (4) by friction of the peripheral surface (20) against an upper face (13) of the nut (4),

   - the guide (18) includes a housing (28) arranged between the fingers (21) to receive the roller (19).
2. The device (3) according to claim 1, characterized in that the guide (18) includes a body (22) from which each finger (21) extends in a projecting manner, this body (22) being drilled by a bore (23) for the passage of the roller (19).
3. The device (3) according to claim 2, characterized in that each finger (21) has a longitudinal section (24) which extends from the body (22), and a bent section (26) which extends transversely the longitudinal section (24).
4. The device (3) according to claim 3, characterized in that the roller (19) is mounted in rotation about an axis (X) parallel to the longitudinal section (24) of the fingers (21).
5. The device (3) according to one of the preceding claims, characterized in that it includes an end-piece (30) on which the roller (19) is mounted, this end-piece (30) being provided with a shank (31) suited to come to be housed in a complementary recess (17) formed at an end of a drive shaft (16) of an automatic screwdriver (2).
6. The device (3) according to claim 5, characterized in that the end-piece (30) is provided with a threaded head (34), and the roller (19) is provided with a tapped bore (35) by which the roller (19) can be fixed on the end-piece (30) by screwing on the threaded head (34) .
7. The device (3) according to one of the preceding claims, characterized in that it includes an adapter (36) by which the device (3) can be fixed on an automatic screwdriver (2).
8. The device (3) according to one of the preceding claims, characterized in that the peripheral surface (20) of the roller (19) is elastic.
9. The device (3) according to claim 8, characterized in that the roller (19) is made from an elastic material.
10. A screwing tool (1) including an automatic screwdriver (2) provided with a drive shaft, and a device (3) according to one of the preceding claims mounted on the automatic screwdriver (2), the roller (19) being integral in rotation with the drive shaft (16).

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