FR3058081B1 - FASTENING SYSTEM FOR RETAINING A SCREW TO A TOOL WHEN A SCREW IS TAPPED OR DEDICATED TO A WORKPIECE. - Google Patents

Abstract

- Fixation system for holding a screw to a tool when screwing or unscrewing the screw on a workpiece. - The fixing system (1) for retaining a screw to a tool (7) during a screwing or unscrewing of the screw on a workpiece using said tool (7), the tool (7) comprising a rod (5) having a tool end adapted to a head of the screw, the tool (7) enabling the screw to be screwed or unscrewed parallel to a main axis (13) of the system (1), the system ( 1) comprising a holding device (8) configured to occupy at least a first position in which the holding device (8) prohibits the displacement of the screw head (2) on the tool end, or a second position in which the holding device (8) allows said displacement of the head of the screw (2).

Description

TECHNICAL AREA

The present invention relates to a fastening system for holding a screw to a tool when screwing or unscrewing the screw on a workpiece.

STATE OF THE ART The assembly or disassembly of parts often requires the use of a tool such as a screwdriver or a socket wrench to perform screwing operations or screw unscrewing.

In the assembly of parts, in particular, in the assembly of aircraft parts, it is imperative not to lose screws. Thus, it is often necessary for the operator to be able to hold the screw with one hand and the tool with the other. However, in confined areas, the operator does not always have the possibility to use both hands.

Today, one of the most common solutions is to use a magnetic screwdriver to hold the screw and screw or unscrew with one hand.

However, in case of contact of the screw with another object, the magnetic force of the screwdriver may not allow to hold the screw which can fall.

STATEMENT OF THE INVENTION

The present invention aims to overcome this drawback by proposing a fastening system for retaining a screw to a tool during an operation of screwing or unscrewing the screw on a workpiece, without the risk that the screw will fall when the operation. To this end, the invention relates to a fastening system for retaining a screw to a tool during screwing or unscrewing of the screw on a workpiece with said tool, the tool comprising a rod having one end , said tool end, is complementary to a head of the screw and the other end, said end sleeve, is attached to a handle, the tool for screwing or unscrewing the screw parallel to a main axis of the system which corresponds to the longitudinal axis of the screw during its screwing or unscrewing by the tool.

According to the invention, the system comprises: a device for holding the screw head configured to occupy at least one of the following positions: a first position in which the holding device prohibits the movement of the head of the screw on the tool end in the direction of the main axis, or o a second position in which the holding device allows said displacement of the head of the screw; a support device on which the holding device is fixed.

Thus, thanks to the invention, the screw is mechanically retained on the tool when the holding device occupies the first position. It is thus retained in a safer and more effective way than if it were retained magnetically.

In addition, the system further comprises a return device configured to exert a first force directed towards the main axis on the holding device to bring it to the first position, the holding device being brought to the second position when a second force applied to the holding device in the opposite direction to the tool end exceeds a defined threshold, the second applied force being parallel to the main axis.

According to a first embodiment, the support device is configured to guide the holding device so that it moves parallel to the main axis, and in that the system further comprises a return device configured to exert a third force on the support device to bring the support device to the tool end.

According to a variant of the first embodiment: the holding device comprises a bushing adapted to receive the head of the screw, the bushing being configured to guide the screw along the main axis; the return device comprises a plurality of springs; with a blade arranged in a ring in the extension of a free end of the sleeve, said first end of the sleeve, each leaf spring being configured to exert a restoring force which corresponds to a centripetal radial restoring force, all of said return forces forming said first force, each leaf spring extending radially under the action of the second force, - the support device comprises a plate perpendicular to the main axis and comprises a hole whose shape corresponds to a section cross section of the rod of the tool, the plate being fixed to a second end of the sleeve, the plate being configured to slide along the shank of the tool through said hole; the return device comprises a helical spring in which the shank of the tool is slidable, a first end of the coil spring being fixed to the plate, a second end being configured to rest against the handle of the tool.

In addition, the plurality of leaf springs comprises at least one straight leaf spring and at least one leaf spring curved inwardly of the sleeve, a straight leaf spring being alternately disposed with a domed leaf spring.

Furthermore, the fastening system comprises that it further comprises a sleeve configured to guide the coil spring along the rod, the sleeve at least partially enveloping the coil spring.

According to another variant of the first embodiment: the holding device comprises two arms and a jaw provided with two parts, each of the parts being fixed respectively to a first end of an arm, each arm being mounted in pivot connection on the support device, the two parts of the jaw deviating radially under the action of the second force and coming closer radially under the action of the return device, - the return device comprises a helical spring in which the rod of the the tool is slidable, a first end of the coil spring being fixed to a second end of each arm and a second end of the coil spring being fixed to the handle, the coil spring being configured to compress radially under a reciprocating action. the second end of an arm relative to the second end of the other arm, - the The backing device comprises the coil spring configured to also compress longitudinally under the action of the movement of the support device towards the handle of the tool, the support device comprises a hollow cylinder in which the tool end is configured. to slide.

In addition, each of the jaw portions includes a surface configured to abut the workpiece, said surface having a curved shape so that said surface is configured to rest on the workpiece when the two parts of the jaw move apart. .

According to a second embodiment: the support device comprises a socket configured to receive the tool end; - The return device comprises at least one coil spring whose axis is parallel to the main axis, a first end of the spring being fixed to the sleeve, a second end of the spring being fixed to the cam, - the holding device comprises at least one cam, said cam being configured to deviate radially from the tool end under the action of the second force, the cam including a first surface configured to remain resting on the tool end when said cam moves away from the tool end, the cam having a second curved surface configured to remain resting on the workpiece as said cam moves away from the tool end. The invention also relates to a tool comprising a fastening system such as that described above. The invention also relates to a method of screwing a screw by a tool comprising a fastening system such as that described above.

According to the invention, the method comprises the following steps: a step of placing the screw head in the holding device occupying the first position which prevents the displacement of the screw head on the tool end in the direction of the main axis; a step of partial screwing of the screw on the part; a step of releasing the screw head of the holding device occupying the second position which authorizes said displacement of the head of the screw.

For example, the release step consists of applying the second force parallel to the main axis on the holding device in the opposite direction to the tool end to a defined threshold that makes it possible to go against the first force exercised by the return device. The invention also relates to a method of unscrewing a screw by a tool comprising a fastening system as described above.

According to the invention, the method comprises the following steps: a step of positioning the holding device in the second position to allow the movement of the screw head in the holding device; a step of partially unscrewing the screw; - A step of holding the head of the screw in the holding device occupying the first position.

In addition, the method furthermore comprises, in the step of holding the head of the screw, a step of bringing the support device to the tool end implemented by the return device.

BRIEF DESCRIPTION OF THE FIGURES The invention, with its features and advantages, will emerge more clearly on reading the description given with reference to the appended drawings, in which: FIG. 1 corresponds to a perspective representation of a variant of a mode embodiment of the fastening system mounted on a socket wrench; - Figure 2 shows an exploded view of the fastening system of Figure 1; - Figure 3 corresponds to a perspective representation of the same variant of an embodiment of the fastening system mounted on a screwdriver; - Figure 4 shows an exploded view of the fastening system of Figure 3; FIG. 5 represents a perspective view of the holding device of the fastening system according to the embodiments of FIGS. 1 to 4; FIG. 6 represents a front view of the holding device of the fastening system according to the embodiments of FIGS. 1 to 4; - Figure 7 is a perspective view of the retaining device holding a screw according to the embodiments of Figures 1 to 4; - Figure 8 shows a side view of the holding device leaving free passage of the screw according to the embodiments of Figures 1 to 4; FIG. 9 represents a perspective view of the holding device according to the embodiment of FIGS. 2 and 4; - Figure 10 shows a perspective view of the holding device implementing the method of screwing a screw into a workpiece; - Figure 11 shows a side view of the fastening system according to another embodiment of the embodiment; - Figure 12 shows a side view of the fastening system according to the variant of Figure 11 implementing the method of screwing a screw into a workpiece; - Figure 13 shows a cross section of the fastening system according to another embodiment wherein the holding device retains a screw; FIG. 14 represents a front view of the fastening system of FIG. 13; - Figure 15 shows a cross section of the fastening system according to another embodiment wherein the holding device leaves free passage of a screw; FIG. 16 represents a front view of the fastening system of FIG. 15; - Figure 17 shows a cross section of the fastening system implementing the screwing process; FIG. 18 represents a synoptic view of the steps of the screwing method; FIG. 19 represents a synoptic view of the steps of the unscrewing process.

DETAILED DESCRIPTION

The remainder of the description will refer to the figures cited above.

FIG. 1 illustrates an embodiment of the fastening system 1 intended to hold a screw 2 to a tool 7 during screwing or unscrewing of the screw 2 on a part 9 by means of said tool 7 (FIGS. 13).

A screw 2 corresponds to a fixing member which comprises a threaded rod 2b and a head 2a. The screw head 2a may be an externally driven head such as a polygonal head (as shown in Figs. 14) or an impression head (as shown in Fig. 10). For example, the part 9 corresponds to a part to fix to an element. The tool 7 comprises a rod 5, one end 7a, said tool end, is complementary to a head 2a of the screw 2 and the other end 7b, said end sleeve, being attached to a handle 7c. The tool 7 may correspond to a socket wrench (Figure 2) or a screwdriver (Figure 4). The socket wrench or the screwdriver makes it possible, respectively, to screw or unscrew an externally driven screw 2 or an impression screw 2. The tool 7 makes it possible to screw or unscrew the screw 2 parallel to a main axis 13 of the system 1 which corresponds to the longitudinal axis of the screw 2 during its screwing or unscrewing by the tool 7.

According to the invention, the fastening system 1 comprises a holding device 8 configured to occupy at least one of the following positions: a first position (FIGS. 11 and 13) in which the holding device 8 prohibits the displacement of the head 2a of the screw 2 on the tool end 7a in the direction of the main axis 13, or - a second position (FIGS. 12 and 17) in which the holding device 8 allows the movement of the head 2a of the screw 2.

When the holding device 8 is in the first position, the holding device 8 holds the head 2a of the screw 2 in the socket of the socket wrench or holds the head 2a of the screw 2 at the tool end 7a of the tool 7.

The holding device can occupy the two positions alternately.

The holding device 8 is fixed on a support device 10 of the fastening system 1.

Advantageously, the fastening system 1 also comprises a return device (8a, 8b, 8f, 8h) configured to exert a first force F1 directed towards the main axis 13 on the holding device 8 in order to bring it to the first position. The holding device 8 is moved to the second position when a second force F2 applied to the holding device 8 in the opposite direction to the tool end 7a exceeds a defined threshold. The second applied force F2 is parallel to the main axis 13.

The reference F1 in FIGS. 6, 11 and 13 represents forces whose set is equal to the first force.

The reference F2 in FIGS. 10, 12 and 13 represents the direction of the second force.

According to a first embodiment, the support device 10 comprises a bushing configured to receive the tool end 7a (FIGS. 13, 15 and 17).

The holding device 8 comprises at least one cam 15 (FIGS. 13 to 17). Said cam 15 is configured to deviate radially from the tool end 7a under the action of the second force F2. The cam 15 includes a first surface 8c configured to remain in abutment on the tool end 7a as said cam 15 moves away from the tool end 7a.

The cam 15 has a second curved surface 8d configured to remain resting on the part 9 when said cam 15 deviates from the tool end 7a.

The return device 8f comprises at least one helical spring whose axis 14 is parallel to the main axis 13 (FIG. 13). A first end 8b1 of the spring is fixed to the socket of the support means 10. A second end 8b2 of the spring is fixed to the cam 15.

Advantageously, so that the spring can return the cam 15 in the first position, the spring has sufficient rigidity so that the longitudinal axis 14 of the spring and the main axis 13 of the system 1 are parallel to each other at least over one half of the spring. spring which is fixed on the support device 10.

When the holding device 8 is in the first position, the cams 15 are sufficiently close to each other or to each other to prevent the displacement of the head 2a of the screw 2 on the tool end 7a in the direction of the main axis 13. When the holding device 8 is in the second position, the cams 15 are sufficiently far apart to allow the displacement of the head 2a of the screw 2 in order to disengage the screw 2 at the end of the screwing or before unscrewing.

According to a second embodiment, the support device 10 is configured to guide the holding device 8 so that it moves parallel to the main axis 13 (FIGS. 1 to 12).

In this second embodiment, the system 1 further comprises a return device 8g, 8i configured to exert a third force F3 on the support device 10 to bring the support device 10 to the tool end 7a

The reference F3 in FIGS. 10 and 11 represents the direction of the third force.

According to a first variant of this second embodiment (FIGS. 1 to 10), the holding device 8 comprises a bushing 3 adapted to receive the head 2a of the screw 2. This bushing 3 is configured to guide the screw 2 according to FIG. main axis 13.

The return device comprises a plurality of leaf springs 8a, 8b arranged in a ring in the extension of a free end 3a of the sleeve 3, said first end 3a of the sleeve 3.

Each leaf spring 8a, 8b is configured to exert a restoring force which corresponds to a centripetal radial restoring force. All of said restoring forces form said first force F1.

The leaf springs 8a, 8b provide a good grip on the heads 2a of screws 2.

Without limitation, the sleeve 3 and the leaf springs 8a, 8b are made of spring steel and consists of twelve leaf springs.

According to a particularity, the plurality of leaf springs 8a, 8b comprises at least one straight leaf spring 8a and at least one curved leaf spring 8b towards the inside of the sleeve 3. A right leaf spring 8a is arranged alternately with a curved leaf spring 8b.

The support device 10 comprises a plate perpendicular to the main axis 13 and comprises a hole whose shape corresponds to a cross section of the rod 5 of the tool 7. The plate is fixed to a second end 3b of the sleeve 3 Thus, the plate can slide along the rod 5 of the tool 7 through said hole.

To exert the third force F3, the return device 8g comprises a helical spring 4 in which the rod 5 of the tool 7 can slide. A first end 4a of the coil spring 4 is fixed to the plate. A second end 4b of the coil spring 4 is configured to abut or be fixed against the handle 7c of the tool 7. (FIGS. 2 and 4)

Advantageously, the fastening system 1 further comprises a sleeve 6 configured to guide the helical spring 4 along the rod 5. The sleeve 6 at least partially envelops the helical spring 4.

According to this first variant, when the holding device 8 is in the first position, the leaf springs 8a, 8b are sufficiently close to each other to prevent the displacement of the head 2a of the screw 2 on the tool end 7a in the direction of the main axis 13. When the holding device 8 is in the second position, the leaf springs 8a, 8b are sufficiently spaced from each other to allow the displacement of the head 2a of the screw 2 so to release the screw 2 at the end of the screwing or before unscrewing.

According to a second variant of the second embodiment (FIGS. 11 and 12), the holding device 8 comprises two arms 12 and a jaw 17 provided with two parts 16. Each of the parts 16 is fixed respectively to a first end 12a of a arm 12. Each arm 12 is mounted pivotably connected to the support device 10. The two parts 16 of the jaw 17 radially deviate under the action of the second force F2 (FIG. 12) and move radially under the same direction. action of the return device 8h (Figure 11).

The return device 8h comprises a helical spring 4 in which the rod 5 of the tool 7 can slide. A first end of the coil spring 4 is fixed on a second end 12b of each arm 12 and a second end of the coil spring 4 is fixed on the handle 7c. The coil spring 4 is configured to compress radially under an action of bringing the second end 12b of an arm 12 closer to the second end 12b of the other arm 12.

The support device 10 comprises a hollow cylinder in which the tool end 7a is slidably configured.

The return device 8i comprises the helical spring 4 configured to compress longitudinally under the action of the displacement of the support device 10 towards the handle 7c of the tool 7.

According to this variant, the coil spring 4 is thus configured to compress radially and longitudinally.

In order to facilitate the opening of the jaw 17, each of the parts 16 of the jaw 17 comprises a surface 8e configured to bear on the part 9. This surface 8e has a curved shape so that said surface 8e is configured to remain in position. bearing on the part 9 when the two parts 16 of the jaw 17 move apart.

According to this second variant, when the holding device 8 is in the first position, the two parts 16 of the jaw 17 are sufficiently close to each other to prohibit the movement of the head 2a of the screw 2 on the end of tool 7a in the direction of the main axis 13. When the holding device 8 is in the second position, the two parts 16 of the jaw 17 are sufficiently spaced from each other to allow the movement of the head 2a of the screw 2 to release the screw 2 at the end of the screwing or before unscrewing.

The fixing system 1 as described above makes it possible to implement a screwing method and a method of unscrewing a screw 2 by a tool 7 comprising the fastening system 1.

The screwing method comprises the following steps: a step E11 of setting up the head 2a of the screw 2 in the holding device 8 occupying the first position which prevents the displacement of the head 2a of the screw 2 on the tool end 7a in the direction of the main axis 13; a step E12 of partial screwing of the screw 2 on the part 9; a step E13 of release of the head 2a of the screw 2 of the holding device 8 occupying the second position which authorizes said displacement of the head 2a of the screw 2.

For a fastening system 1 according to the second embodiment, the method further comprises a step E13 release which consists in applying the second force F2 parallel to the main axis 13 on the holding device 8 in the opposite direction to the tool end 7a to a defined threshold which makes it possible to go against the first force F1 exerted by the return device 8a, 8b, 8h.

The unscrewing method comprises the following steps: a step E21 for positioning the holding device 8 in the second position in order to allow the displacement of the head 2a of the screw 2 in the holding device 8; a step E22 of partial unscrewing of the screw 2; a step E24 for holding the head 2a of the screw 2 in the holding device 8 occupying the first position.

For a fastening system 1 according to the second embodiment, the unscrewing method further comprises, in step E24 of holding the head 2a of the screw 2, a step E23 for feeding the support device 10 towards the tool end 7a implemented by the return device 8g, 8i.

Claims (13)

1. Fastening system for retaining a screw (2) to a tool (7) when screwing or unscrewing the screw (2) on a workpiece (9) by means of said tool (7), tool (7) comprising a rod (5) of which one end (7a), said tool end (7a), is complementary to a head (2a) of the screw (2) and the other end (7b), said handle end, is fixed to a handle (7c), the tool (7) for screwing or unscrewing the screw (2) parallel to a main axis (13) of the system (1) which corresponds to the longitudinal axis of the screw (2) during its screwing or unscrewing by the tool (7), characterized in that the system (1) comprises: - a holding device (8) for the screw head (2a) (2 ) configured to occupy at least one of the following positions: a first position in which the holding device (8) prohibits the displacement of the head (2a) of the screw (2) on the end of the tool (7a) in the direct ion of the main axis (13), or o a second position in which the holding device (8) allows said displacement of the head (2a) of the screw (2); - a support device (10) on which is fixed the holding device (8) a return device (8a, 8b, 8f, 8h) configured to exert a first force directed towards the main axis (13) on the device holding means (8) to bring it to the first position, the holding device (8) being moved to the second position when a second force (F2) applied to the holding device (8) in the opposite direction to the the tool end (7a) exceeds a defined threshold, the second applied force (F2) being parallel to the main axis (13). 2. System according to claim 1, characterized in that the support device (10) is configured to guide the holding device (8) so that it moves parallel to the main axis (13), and in that the system (1) further comprises a return device (8g, 8i) configured to exert a third force (F3) on the support device (10) to bring the support device (10) towards the end of the tool (7a). 3. System according to any one of claims 1 or 2, characterized in that: - the holding device (8) comprises a sleeve (3) adapted to receive the head (2a) of the screw (2), the socket (3) being configured to guide the screw (2) along the main axis (13), - the return device comprises a plurality of leaf springs (8a, 8b) arranged in a ring in the extension of a free end ( 3a) of the sleeve (3), said first end of the sleeve (3), each leaf spring (8a, 8b) being configured to exert a restoring force which corresponds to a centripetal radial restoring force, all of said return forces forming said first force (F1), each leaf spring (8a, 8b) deviating radially under the action of the second force (F2), - the support device (10) comprises a plate perpendicular to the main axis (13) and comprises a hole whose shape corresponds to a cross section of the tig e (5) of the tool (7), the plate being fixed to a second end (3b) of the sleeve (3), the plate being configured to slide along the rod (5) of the tool (7). ) through said hole, - the return device (8g) comprises a helical spring (4) in which the rod (5) of the tool (7) is slidable, a first end (4a) of the coil spring (4) being attached to the plate, a second end (4b) being configured to bear against the handle (7c) of the tool (7). 4. System according to claim 3, characterized in that the plurality of leaf springs (8a, 8b) comprises at least one straight leaf spring (8a) and at least one domed leaf spring (8b) towards the inside of the bushing (3), a straight-leaf spring (8a) being arranged alternately with a curved-leaf spring (8b). 5. System according to any one of claims 3 or 4, characterized in that it further comprises a sleeve (6) configured to guide the coil spring (4) along the rod (5), the sleeve (6). ) at least partially enveloping the coil spring (4). 6. System according to any one of claims 1 to 2, characterized in that: - the holding device (8) comprises two arms (12) a jaw (17) provided with two parts (16), each of the parts ( 16) being respectively fixed to a first end (12a) of an arm (12), each arm (12) being pivotally connected (11) to the support device (10), the two parts (16) of the jaw (17) deviating radially under the action of the second force (F2) and approaching radially under the action of the return device (8h), - the return device (8h) comprises a helical spring (4) wherein the rod (5) of the tool (7) is slidable, a first end of the coil spring (4) being fixed on a second end (12b) of each arm (12) and a second end of the coil spring (4). ) being fixed on the handle (7c), the coil spring (4) being configured to compress radially under an action of a bringing together of the second end (12b) of one arm (12) relative to the second end (12b) of the other arm (12), - the return device (4) comprises the coil spring (4) configured to also compress longitudinally under the action of the movement of the support device (10) towards the handle (7c) of the tool (7), - the support device (10) comprises a hollow cylinder in which the tool end (7a) is configured to slide. 7. System according to claim 6, characterized in that each of the parts (16) of the jaw (17) comprises a surface (8e) configured to rest on the part (9), said surface (8e) having a shape curved so that said surface (8e) is configured to remain resting on the piece (9) when the two parts (16) of the jaw (17) move apart. 8. System according to claim 1, characterized in that: - the support device (10) comprises a socket configured to receive the tool end (7a); the return device (8f) comprises at least one helical spring whose axis (14) is parallel to the main axis (13), a first end (8b1) of the spring being fixed to the sleeve, a second end ( 8b2) of the spring being fixed to the cam (15), the holding device (8) comprises at least one cam (15), said cam (15) being configured to deviate radially from the tool end ( 7a) under the action of the second force (F2), the cam (15) comprising a first surface (8c) configured to remain resting on the tool end (7a) when said cam (15) departs the tool end (7a), the cam (15) having a second curved surface (8d) configured to remain resting on the workpiece (9) when said cam (15) deviates from the end of tool (7a). 9. Tool, comprising a fastening system (1) according to any one of claims 1 to 8. 10. A method of screwing a screw by a tool comprising a fastening system according to any one of claims 1 to 8, characterized in that it comprises the following steps: - a step (E11) of setting up of the head (2a) of the screw (2) in the holding device (8) occupying the first position which prevents the displacement of the head (2a) of the screw (2) on the tool end (7a) in the direction of the main axis (13); - A step (E12) of partial screwing of the screw (2) on the workpiece (9); - A step (E13) of releasing the head (2a) of the screw (2) of the holding device (8) occupying the second position which allows said displacement of the head (2a) of the screw (2). 11. The method of claim 10, characterized in that the step (E13) release comprises applying the second force (F2) parallel to the main axis (13) on the holding device (8) in the opposite direction to the tool end (7a) to a defined threshold which makes it possible to go against the first force (F1) exerted by the return device (8a, 8b, 8h). 12. A method of unscrewing a screw by a tool comprising a fastening system according to any one of claims 1 to 8, characterized in that it comprises the following steps: - a step (E21) of positioning the device of holding (8) in the second position to allow movement of the head (2a) of the screw (2) in the holding device (8); a step (E22) of partial unscrewing of the screw (2); - A step (E24) for holding the head (2a) of the screw (2) in the holding device (8) occupying the first position. 13. The method of claim 12, characterized in that it further comprises in step (E24) for holding the head (2a) of the screw (2): - a step (E23) of supply from the support device (10) to the tool end (7a) implemented by the return device (8g, 8i).