FR3058081A1 - 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 retaining 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 or unscrewing operations.

In the assembly of parts, in particular, in the assembly of aircraft parts, it is imperative not to lose any 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 is not always able to use both hands.

One of the most widely used solutions today is to use a magnetic screwdriver to hold the screw and thus screw it in and out with one hand.

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

STATEMENT OF THE INVENTION

The object of the present invention is to overcome this drawback by proposing a fixing system intended to retain a screw to a tool during a screwing or unscrewing operation of the screw on a workpiece, without the risk that the screw will fall during the operation.

To this end, the invention relates to a fixing system intended to retain a screw to a tool during a screwing or unscrewing of the screw on a workpiece using said tool, the tool comprising a rod of which one end , said tool end, is complementary to a head of the screw and the other end, said handle end, is fixed to a handle, the tool making it possible to screw or unscrew the screw parallel to a main axis of the system which corresponds to the longitudinal axis of the screw when it is screwed in or out by the tool.

According to the invention, the system comprises:

- a screw head holding device configured to occupy at least one or the other of the following positions:

o 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 authorizes said movement 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 held in a safer and more efficient way than if it were held 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 in order 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 opposite to the tool end exceeds a defined threshold, the second force applied 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 also comprises a return device configured to exert a third force on the support device to bring the support device towards the tool end.

According to a variant of the first embodiment:

- the holding device comprises a socket adapted to receive the head of the screw, the socket being configured to guide the screw along the main axis,

- The return device comprises a plurality of leaf springs arranged in a crown in the extension of a free end of the sleeve, called the first end of the sleeve, each leaf spring being configured to exert a return force which corresponds to a centripetal radial restoring force, all of said restoring forces forming said first force, each leaf spring moving apart radially under the action of the second force,

- The support device comprises a plate perpendicular to the main axis and includes a hole whose shape corresponds to a cross section of the tool shank, the plate being fixed to a second end of the socket, the plate being configured to slide along the tool shank through said hole,

- the return device comprises a helical spring in which the tool rod can slide, a first end of the helical 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 domed leaf spring towards the inside of the sleeve, a straight leaf spring being arranged alternately with a domed leaf spring.

Furthermore, the fixing system comprises that it further comprises a sleeve configured to guide the helical spring along the rod, the sleeve at least partially enveloping the helical 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 approaching radially under the action of the return device,

- The return device comprises a helical spring in which the tool rod can slide, a first end of the helical spring being fixed on a second end of each arm and a second end of the helical spring being fixed on the handle, the spring helical being configured to compress radially under the action of bringing the second end of one arm closer to the second end of the other arm,

- the return device comprises the helical spring configured to also compress longitudinally under the action of the displacement 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 parts of the jaw comprises a surface configured to rest on the part, said surface having a curved shape so that said surface is configured to remain in abutment on the part 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 helical spring whose axis is parallel to the main axis, a first end of the spring being fixed to the bush, a second end of the spring being fixed to the cam,

the holding device comprises at least one cam, said cam being configured to move radially away from the tool end under the action of the second force, the cam comprising a first surface configured to remain in abutment on the tool end when said cam moves away from the tool end, the cam having a second curved surface configured to rest on the workpiece when said cam moves away from the tool end.

The invention also relates to a tool comprising a fixing system such as that described above.

The invention also relates to a method of screwing a screw by a tool comprising a fixing system such as that described above.

According to the invention, the method comprises the following stages:

- A step of positioning the screw head in the holding device occupying the first position which prevents the movement 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 from the holding device occupying the second position which allows said movement of the head of the screw.

For example, the release step consists in applying the second force parallel to the main axis on the holding device opposite to the tool end up to a defined threshold which makes it possible to go against the first force. exerted by the return device.

The invention also relates to a method of unscrewing a screw by a tool comprising a fixing system as described above.

According to the invention, the method comprises the following stages:

- A step of positioning the holding device in the second position to allow the displacement of the head of the screw 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 further comprises previously in the step of holding the head of the screw:

- A step of bringing the support device to the tool end 10 implemented by the return device.

BRIEF DESCRIPTION OF THE FIGURES

The invention, with its characteristics and advantages, will emerge more clearly on reading the description made with reference to the appended drawings in which:

- Figure 1 corresponds to a perspective representation of a variant of an embodiment of the fixing system mounted on a socket wrench;

- Figure 2 shows an exploded view of the fastening system of Figure 20 1;

- Figure 3 corresponds to a perspective representation of the same variant of an embodiment of the fixing system mounted on a screwdriver;

- Figure 4 shows an exploded view of the fastening system of Figure

3;

- Figure 5 shows a perspective view of the holding device of the fixing system according to the embodiments of Figures 1 to 4;

- Figure 6 shows a front view of the fixing system holding device according to the embodiments of Figures 1 to 4;

- Figure 7 corresponds to a perspective view of the holding device retaining a screw according to the embodiments of Figures 1 to 4;

- Figure 8 shows a side view of the holding device allowing free passage of the screw according to the embodiments of Figures 1 to 4;

- Figure 9 shows a perspective view of the holding device according to the embodiment of Figures 2 and 4;

- Figure 10 shows a perspective view of the holding device implementing the method of screwing a screw in a room;

- Figure 11 shows a side view of the fastening system according to another variant of the embodiment;

- Figure 12 shows a side view of the fixing system according to the variant of Figure 11 implementing the method of screwing a screw in a room;

- Figure 13 shows a cross section of the fixing system according to another embodiment in which the holding device retains a screw;

- Figure 14 shows a front view of the fixing system of Figure 13;

- Figure 15 shows a cross section of the fastening system according to another embodiment in which the holding device allows free passage of a screw;

- Figure 16 shows a front view of the fixing system of Figure 15;

- Figure 17 shows a cross section of the fastening system implementing the screwing process;

- Figure 18 shows a block diagram of the steps of the screwing process;

- Figure 19 shows a block 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 fixing system 1 intended to retain a screw 2 to a tool 7 during a screwing or unscrewing of the screw 2 on a part 9 using said tool 7 (FIGS. 10 to 13).

A screw 2 corresponds to a fixing member which comprises a threaded rod 2b and a head 2a. The screw head 2a can be an externally driven head such as a polygonal head (as shown in Figures 14) or an impression head (as shown in Figure 10).

w For example, part 9 corresponds to a part to be fixed to an element.

The tool 7 comprises a rod 5, one end of which 7a, called the tool end, is complementary to a head 2a of the screw 2 and the other end 7b, called the sleeve end, being fixed to a handle 7c.

Tool 7 can correspond to a socket wrench (Figure 2) or a screwdriver (Figure 4). The socket wrench or the screwdriver allows, respectively, to screw or unscrew a screw 2 with external drive or a screw 2 with impression.

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 when it is screwed in or out by the tool 7.

According to the invention, the fastening system 1 comprises a holding device 8 configured to occupy at least one or the other of the following positions:

a first position (FIGS. 11 and 13) in which the holding device 8 prohibits the movement 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 authorizes the displacement 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 keeps the head 2a of the screw 2 at the tool end 7a of tool 7.

The holding device can occupy the two positions alternately.

The holding device 8 is fixed to a support device 10 of the fixing system 1.

Advantageously, the fixing 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 towards the first position. The holding device 8 is brought to the second position when a second force F2 applied to the holding device 8 in the direction opposite 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 Figures 6, 11 and 13 represents forces the whole of which is equal to the first force.

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

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

The holding device 8 comprises at least one cam 15 (Figures 25 13 to 17). Said cam 15 is configured to move radially away from the tool end 7a under the action of the second force F2. The cam 15 comprises a first surface 8c configured to remain in abutment on the tool end 7a when said cam 15 moves away from the tool end 7a.

The cam 15 has a second curved surface 8d configured to remain in abutment on the part 9 when said cam 15 moves away 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 (Figure 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 bring the cam 15 back into 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 mutually parallel at least over half of the spring which is fixed on the support device 10.

When the holding device 8 is in the first position, the cams 15 are close enough to one another or to one another to prevent the movement 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 distant to allow the displacement of the head 2a of the screw 2 in order to release 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 (Figures 1 to 12).

In this second embodiment, the system 1 also comprises a return device 8g, 8i configured to exert a third force

F3 on the support device 10 in order to bring the support device 10 towards the tool end 7a

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

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

The return device comprises a plurality of leaf springs 8a,

8b arranged in a crown in the extension of a free end 3a of the socket 3, called the first end 3a of the socket 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 ensure a good grip on the heads 2a of screws 2.

Without limitation, the socket 3 and the leaf springs 8a, 8b are made of spring steel and is made up of twelve leaf springs.

According to one feature, 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 sleeve 3. A straight leaf spring 8a is arranged alternately with a domed 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 helical spring 4 is fixed to the plate. A second end 4b of the helical spring 4 is configured to rest or be fixed against the handle 7c of the tool 7. (Figures 2 and 4)

Advantageously, the fixing system 1 also 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 close enough to each other to prevent 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 leaf springs 8a, 8b are sufficiently spaced from one another to allow the displacement of the head 2a of the screw 2 in order to free the screw 2 at the end of the screwing or before unscrewing.

According to a second variant of the second embodiment (Figures 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 in pivot connection 11 on the support device 10. The two parts 16 of the jaw 17 move apart radially under the action of the second force F2 (FIG. 12) and come closer radially under the action of the reminder device 8h (figure 11).

The 8h return device 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 to a second end 12b of each arm 12 and a second end of the coil spring 4 is fixed to the handle 7c. The helical spring 4 is configured to compress radially under the action of bringing the second end 12b of one 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 configured to slide.

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 helical spring 4 is therefore 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 rest on the part 9. This surface 8e has a curved shape so that said surface 8e is configured to remain in support on the part 9 when the two parts

16 of jaw 17 move away.

According to this second variant, when the holding device 8 is in the first position, the two parts 16 of the jaw 17 are close enough to each other to prevent the movement 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 two parts 16 of the jaw 17 are sufficiently spaced from one another to allow the displacement of the head 2a of the screw 2 in order to release the screw 2 at the end of 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 fixing system 1.

The screwing process includes the following steps:

a step E11 of placing the head 2a of the screw 2 in the holding device 8 occupying the first position which prohibits the movement of the head 2a of the screw 2 on the tool end 7a in the direction of main axis 13;

a step E12 of partial screwing of the screw 2 on the part 9;

a step E13 of releasing the head 2a from the screw 2 of the holding device 8 occupying the second position which authorizes said movement of the head 2a of the screw 2.

For a fastening system 1 according to the second embodiment, the method further comprises a release step E13 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 up 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 process includes the following steps:

- A step E21 of positioning the holding device 8 in the second position in order to authorize the movement of the head 2a of the screw 2 in the holding device 8;

a step E22 of partially unscrewing 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, previously in step E24 of holding the head 2a of the screw 2, a step E23 of supplying the support device 10 towards the tool end 7a implemented by the return device 8g, 8i.

Claims (14)

1. Fixing system intended to retain a screw (2) to a tool (7) during a screwing or unscrewing of the screw (2) on a part (9) using said tool (7), l tool (7) comprising a rod (5), one end (7a) of which, said tool end (7a), is complementary to a head (2a) of the screw (2) and the other end (7b), said end of the handle, is fixed to a handle (7c), the tool (7) making 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) when it is screwed or unscrewed 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 or the other of the following positions: a first position in which the holding device (8) prohibits the movement of the head (2a) of the screw (2) on the tool end (7a) in the direction of the main axis (13), or o a second position in which the holding device (8) authorizes said movement of the head (2a) of the screw (2); - a support device (10) on which the holding device (8) is fixed. 2. System according to claim 1, characterized in that it further comprises a return device (8a, 8b, 8f, 8h) configured to exert a first force directed towards the main axis (13) on the holding device (8) in order to bring it to the first position, the holding device (8) being brought to the second position when a second force (F2) applied to the holding device (8) opposite the end tool (7a) exceeds a defined threshold, the second force (F2) applied being parallel to the main axis (13). 3. System according to any one of claims 1 or 2, 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 5 (8g, 8i) configured to exert a third force (F3) on the support device (10) in order to bring the support device (10) to the tool end (7a). 4. System according to any one of claims 1 to 3, characterized in that: 10 - the holding device (8) comprises a socket (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 crown in the extension of a free end (3a) of The bush (3), called the first end of the bush (3), each leaf spring (8a, 8b) being configured to exert a restoring force which corresponds to a centripetal radial restoring force, all of said forces recall forming said first force (F1), each leaf spring (8a, 8b) deviating radially under the action of the second force (F2), 20 - 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 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, 25 - 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 helical spring (4) being fixed to the plate , a second end (4b) being configured to bear against the handle (7c) of the tool (7). 5. System according to claim 4, 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 sleeve (3), a straight leaf spring (8a) being arranged alternately with a domed leaf spring (8b). 6. System according to any one of claims 4 or 5, characterized in that it further comprises a sleeve (6) configured to guide the helical spring (4) along the rod (5), the sleeve (6 ) at least partially enveloping the helical spring (4). 7. System according to any one of claims 1 to 3, 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 fixed respectively on a first end (12a) of an arm (12) , each arm (12) being mounted in pivot connection (11) on the support device (10), the two parts (16) of the jaw (17) moving apart 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) in which the rod (5) of the tool (7) can slide, a first end of the helical spring (4) being fixed on a second end (12b) of each arm (12) and a second end of the helical spring (4) being fixed on the handle (7c), the helical spring (4) being configured to compress radially under the action of bringing the second end together (12b ) an arm (12) relative to the second end (12b) of the other arm (12), the return device (4) comprises the helical spring (4) configured to also compress longitudinally under the action of the displacement 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. 8. System according to claim 7, 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 in abutment on the part (9) when the two parts (16) of the jaw (17) move apart. 9. System according to any one of claims 1 or 2, 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 bush, 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 move radially away from the tool end (7a) under the action of the second force (F2) , the cam (15) comprising a first surface (8c) configured to remain in abutment on the tool end (7a) when said cam (15) moves away from the tool end (7a), the cam (15) having a second curved surface (8d) configured to remain in contact with the workpiece (9) when said cam (15) moves away from the tool end (7a). 10. Tool, comprising a fixing system (1) according to any one of claims 1 to 9. 11. Method for screwing a screw with a tool comprising a fixing system according to any one of claims 1 to 9, characterized in that it comprises the following steps: - A step (E11) of positioning the head (2a) of the screw (2) in the holding device (8) occupying the first position which prohibits the movement 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 releasing the head (2a) from the screw (2) of the holding device (8) occupying the second position which allows said movement of the head (2a) of the screw (2). 12. Method according to claim 11, characterized in that the release step (E13) 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) up to a defined threshold which makes it possible to go against the first force (F1) exerted by the return device (8a, 8b, 8h). 13. A method of unscrewing a screw by a tool comprising a fixing system according to any one of claims 1 to 9, characterized in that it comprises the following steps: - A step (E21) of positioning the holding device (8) in the second position to allow the movement of the head (2a) of the screw (2) in the holding device (8); - a step (E22) of partially unscrewing the screw (2); - A step (E24) for holding the head (2a) of the screw (2) in the holding device (8) occupying the first position. 14. Method according to claim 12, characterized in that it furthermore comprises, previously in the step (E24) of holding the head (2a) of the screw (2): - A step (E23) of bringing the support device (10) to the tool end (7a) implemented by the return device (8g, 8i). 2/10 3/10