EP0620986B1 - Foldable fastener for a bracelet - Google Patents

Description

The present invention relates to a clasp leaflet for bracelet, and more particularly to a clasp comprising a central spar and one or two pairs of external leaflets formed in stretcher so that, when closing, these leaflets are juxtaposed around the central spar, these leaflets being assembled in their end by a bar for fixing a strand of bracelet or by a cylinder provided to wear such bar.

These clasps are appreciated because they appear very thin when closed because the parts deployants are erased next to each other flat from so as not to protrude from the strip forming the bracelet.

GB-A-1 337 304 describes an example of clasp comprising three arched plates linked in pairs by hinges so that they can be folded down one on the other, the free end of the first and the third plate being respectively connected, also by a hinge, to the bracelet. The third plate is completed lateral flanks whose ends close to the hinge connecting with the second plate are presented in the form of hooks which click into place once the folded clasp, in the axis of the hinge connecting the bracelet to the first plate.

However, the clasp plates previously described are necessarily thin to avoid too much large total thickness of the clasp, therefore deformable despite the presence of longitudinal reinforcing ribs. This characteristic is unlike fold-over clasps stretcher whose leaflets and side member may have a certain thickness to ensure intrinsic rigidity. In consequence, either the first plate is too arched, and hook engagement is loose; either she is too straight, and the engagement is done under elastic tension therefore likely to jump at any time.

Document FR-E-41 138 describes a clasp in stretcher in which the central area of the central spar is provided with engaging lateral projections in position closed, in corresponding accommodation in external leaflets which are made elastic thanks to longitudinal lights. Besides the fact that these lights are difficult to achieve, thereby increasing the cost of manufacturing, the leaflets must necessarily be wide, which greatly limits aesthetic choices.

The document CH 641 332 describes another example of clasp of this type in which the central spar carries along its transverse median axis a shaped anchoring member of rail. The strand fixing bars, or the cylinders carriers of bars, joining the ends of the flyers then snap against each side of the rail when closing. However, again, the realization of this rail of substantial thickness and protruding above the beam is difficult. Moreover, the reliability of closing each leaflet depends on the degree of wear of the single corresponding face of rail.

Furthermore, document EP 0 115 740 discloses a clasp with two leaflets according to the preamble of the claim, of which the central part is made up two parallel beams held apart by a cross median between which comes to fall back, of each end, a folding arm. Each folding arm is provided on most of its side faces exterior of an engaging profile, in the folded position, in a complementary profile provided on the side faces interior of the side members. Each arm is split longitudinally in two blades which are kept apart elastically by an internal spring or due to the shape in tuning fork given to the arm. The manufacture of these arms elastic as well as the double center piece is also complex and expensive.

In a third embodiment described in this document, each folding arm is produced in the form of a single full blade, and we play on a relative elasticity of the side members between the cross member and the hinge link of the arm to forcefully engage notches of reduced arm length. However, the elasticity in spacing of these portions of spars held at each extremity can only be very limited, especially if these stringers must necessarily have a width and minimum thickness.

The present invention relates to a folding clasp for bracelet including a central spar, one end of which is hinged to a pair of outdoor brochures or a brochure single formed in stretcher to allow this or these leaflets, when closing, to land around the central spar, this or these leaflets being at one of the ends connected by a strip for fixing a strand of bracelet or by a carrying cylinder for such bar, the other end of the central beam being articulated either to a second cylinder or bar, or to a second pair of external leaflets, the link between cylinder, or bar, single fold or to the leaflets from the pair of leaflets being made by two lateral uprights forming a connection in inverted U shifting this cylinder or bar above the plan containing the ends of the leaflets.

The object of the present invention is a compound clasp, in version basic, of a reduced number of parts of simplified structure to allow more advantageous manufacturing, and all ensuring high reliability of locking as well as easy closing and opening.

These goals are achieved in what this inverted U link has an elasticity of such that an anchoring member providing the face inside the end of the single leaflet or of each flyer the pair of flyers can come and engage elastically with a complementary body arranged in correspondence on the outer side of the spar central.

In other words, the two amounts and the cylinder constitute an inverted U connection, in other words in bridge, between the two ends of leaflets which can more easily move away elastically to let through the projections in their housing. Indeed, the elasticity desired to obtain sufficient spacing can be distributed by bending along each upright, and by a curvature of the cylinder. So, we can consider the realization by machining of two fold-out cylinder-cylinder assemblies that we simply assemble the spar using two pins.

According to a first embodiment, the lateral uprights are perpendicular to the ends of the leaflets, and the anchors are made in the form of convex projections or housings concaves formed along the inner faces of the ends leaflets, and whose cross section is triangular angle at the top greater than 120 degrees.

In this version including amounts of small dimensions, therefore a little more rigid, we prefer wide, gently sloping notches, with sagging occurring rather at the junction between the bar and the cylinder anyway sufficiently offset from the first notch slope.

According to another embodiment, the amounts lateral are oblique to the ends of the leaflets thus holding the cylinder beyond said extremities. So the anchors are made under the shape of convex projections or concave housings formed along the lower edges of the inner faces of ends of the leaflets, and whose cross section is regular trapezoidal.

In this preferred version, the amounts are longer, so they can flex better, which allows protrusions or deeper housings made under a regular trapezoidal shape to ensure identical effort on opening and closing.

Advantageously, the amounts can have a middle groove between the projection (or housing) and the cylinder, this groove being parallel to them. This groove further increases the bending potential of the uprights by a characteristic elasticity of a C-piece.

Advantageously, the cylinder or the bar can present a middle notch or a pair of notches side. These notches allow for more sagging pronounced the play.

From the above, we see that, thanks to this inverted U link structure, the manufacturer can define easily and precisely the strength of the locking clip of the brochure-cylinder set according to the dimensions defined according to aesthetic criteria, then carry it out reliably during machining which is facilitated.

According to another embodiment, the spar central, formed in one piece or by two blades parallel, has a central indentation ensuring flexibility of the middle parts.

Advantageously, the notch can have a V-shaped part in which a corner is more or less forced, this which allows to adjust the width of the beam just enough to change the latching force accordingly flyers. The position of the corner in the V-shaped part can be adjustable, for example by means of a screw passing through the corner by a tapped hole and bearing against the end of the notch opposite the V-shaped part

Alternatively, the spar can be formed by two parallel blades whose spacing is regulated by one or several transverse screws. Alternatively, this spar is also formed by two parallel blades, but held separated by two pivots, their ends possibly being tightened at will by transverse screws causing a spacing of the middle part of the blades.

• la figure 1 est une vue en perspective d'un premier mode de réalisation du fermoir selon l'invention,
• les figures 2a à 2d illustrent en perspective agrandie le détail de la zone II de la figure 1,
• les figures 3 et 4 illustrent deux variantes de réalisation du fermoir de la figure 1,
• les figures 5, 6, 7 et 8 illustrent en perspective quatre variantes de réalisation du longeron du fermoir.

The invention will be better understood from the study of embodiments taken by way of nonlimiting examples and described by the following figures in which:

• FIG. 1 is a perspective view of a first embodiment of the clasp according to the invention,
• FIGS. 2a to 2d illustrate in enlarged perspective the detail of zone II of FIG. 1,
• FIGS. 3 and 4 illustrate two alternative embodiments of the clasp of FIG. 1,
• Figures 5, 6, 7 and 8 illustrate in perspective four alternative embodiments of the side member of the clasp.

As illustrated in Figure 1, the clasp includes a central beam 10 arched to conform partially to the roundness of the wearer's wrist. Every end of this beam is assembled a folding part movable in pivoting around an axis 14, each piece holding at its other end, also movable in rotation, a strand bracelet 1, 2 made of leather or formed of links metallic.

More particularly, each folding part is consisting of two leaflets 20,21 linked together by a U-shaped bridge embodied by two lateral uprights 22 holding a cylinder 24. In this cylinder 24 is inserted a strip used for fixing strands 1 and 2 of the bracelet. Alternatively, this cylinder 24 can be directly replaced by the bar. These leaflets 20.21 are mounted as a stretcher relative to the central beam 10, that is to say that they are located on either side of this spar so as to come to be juxtaposed along the edges of this spar when the part is closed folding as well illustrated on the right side of the figure.

By defining by Y the longitudinal axis of each end of leaflets 20,21, by Z an axis orthogonal to the plane containing the two axes Y of leaflets 20,21, and by X the axis passing through the cylinder 24, therefore parallel to the plane previously defined, we can see how the presence of uprights 22 allows to shift the position of this cylinder 24 more or less above this plane containing the ends flyers. Incidentally, the presence of this shift makes that during the closing, the leaflets are erased in juxtaposition all along the central spar 10. But above all, the presence of these uprights 22 makes it possible to hold the ends of leaflets 20,21 with flexibility exactly controlled. This mechanical characteristic makes it possible to have advantageously fastening members 26 in the area referenced II, that is to say along the inner face of the end of the leaflets 20,21, parallel to the Y axis, and this in relation to complementary bodies 12 located substantially in the middle of the side member of the spar central 10.

In a first embodiment of the area II, illustrated in an enlarged manner in FIG. 2a, the uprights 22 are parallel to the Z axis, therefore orthogonal to leaflet 21. The cylinder 24, oriented along the X axis therefore also orthogonal to the Z axis, is located just above this leaflet 21. The attachment member then presents itself, preferably in the form of a shallow housing 26, oriented along the Y axis, starting practically from the bottom edge of this leaflet up to a height of between half, even two-thirds of the height of the uprights 22. As illustrated, the cross section of this housing 26 is rather triangular isosceles with an angle at the top of around 120 degrees. The length e1 of the part potentially sagging amounts 22 is then substantially equal to the height of the leaflet 21 is included between 1.1 and 1.9 mm.

In Figure 2b is enlarged a second embodiment of zone II of FIG. 1, in which the upright 22 'is oblique, for example by 45 degree angle to the Y axis of the leaflet 21. As a result, the cylinder 24 is offset in front of the end of the leaflet 21 by a distance y2 of in the range of 1 to 1.5 mm. The length e2 of the portion potentially bending amount 22 'is therefore found increased compared to the previous example. The way in this example, under the shape of a housing 26 'always parallel to the Y axis, formed along the lower edge of the leaflet 21, and this on greater depth. The section of this accommodation is then rather isosceles trapezoidal. The complementary body of attachment 12 of the spar 10 is in the form of a convex projection of identical trapezoidal section.

In Figure 2c is illustrated so enlarged a third embodiment of zone II of the Figure 1, in which the cylinder 24 is raised, that is to say that it only leaves from a distance z3 above the upper face of the leaflet 21, increasing that further the distance e3 from the flexible part of the upright 22 '. The organ attachment can either be, as before, a housing 26 ', or as illustrated in this figure, a convex projection 26 '' again trapezoidal section. The organ complementary 12 of the spar 10 can be, as previously, a housing provided at the corresponding height of the edge of the spar 10, or an identical projection but arranged just above so that the 26 '' projection can go over before hanging on below. The space left free under the cylinder 24 facilitates, by elsewhere, the reopening of the clasp because we can insert more easily a fingernail under this cylinder to lift it.

In the example of Figure 2d is illustrated a fourth embodiment of zone II of FIG. 1, in which a groove 23 has been made parallel to the axis Y in the 22 '' upright and part of the leaflet 21, and this between the projection 26 '' and the underside of the cylinder 24. The 22 '' post flexibility then corresponds to that of a C-piece oriented obliquely.

Figure 3 illustrates how a notch central 25 can be arranged in the cylinder 24 so significantly improve the possibility of flexing this cylinder inside a plane orthogonal to the Y axis. similarly, Figure 4 illustrates a cylinder 24 in which we made two notches 27 and 29 close to 22 uprights, which only favors the possibility spacing of each upright 22.

In the majority of cases, one of the forms described above, which is chosen according to the final dimensions of the clasp, then produced by machining, provides elasticity that is both flexible enough to allow easy opening and closing of the clasp, and firm enough for good maintenance of the leaflets a times snapped. However, we can also update take advantage of the available width of the spar 10 to adapt a additional transversal flexibility. For example, the Figure 5 illustrates a central spar formed by two blades 16 and 18 of reduced width in their center to create a notch 15 with triangular ends 17.

We can also consider a central spar consisting of two separate blades 11 and 13 separated in their end by a spacer 19 and in the middle by a screw spacing 30, as shown in Figure 6. More in particular, the head of the screw 30 is reduced to present an intermediate flange 32 bearing on the internal face of the blade 13. Thus, by turning in the counterclockwise, thread 34 pushes back the blade 11, which makes it possible to adjust to a value desired the spacing between the two blades, so the firmness of the snap-in of leaflets.

As an alternative, and as illustrated in the figure 7, the two blades 11 and 13 are kept apart by pivots 48 held by means of transverse pins 49 at breast of notches 7 in portion of circles formed in the face internal of the blades. So we use a screw 40 whose head 42 and the thread are extended on both sides by flyer bars 45 and 47. Screw head 42 pressing in the corresponding housing of the blade 13, a clockwise rotation of this screw causes the ends of the blades 11 and 13 to be clamped, or a spacing of their middle part where the hanging devices 12 for leaflets.

As an alternative, and as illustrated in the example of a single folding clasp 20,21,24 of Figure 8, the one-piece central spar 10 'has a notch 50 long enough, for example half the length of the clasp. This notch includes, for example on its first third, part in V 52, that is to say that its width y decreases linearly and symmetrically relative to the central axis. In this V-shaped part is housed a corner 60, in this case regular trapezoidal angle at vertex identical to that of the V-shaped part 52. This corner 60 is held in place by two lateral tenons 54 of the notch penetrating into two corresponding lateral grooves 64 of the corner. A screw 70 passes longitudinally through this corner in a tapped hole 68 and its end is supported against the end 72 of the notch opposite the V-shaped part

As can easily be understood, the fact of more or less turn the screw 70 in the first direction force the corner in the V-shaped part, which swells transversely the beam 10 'and increases the force attachment of the leaflet 20,21,24. Excessive enlargement can be corrected by turning the screw counterclockwise.

If the last three embodiments described are more complex to carry out, they have the advantage of allowing the user to modify or very easy to correct the firmness of sound clipping clasp. The additional advantage of the illustrated version in Figure 7 is that the screw 40 is confused, very discreet and elegant way, with the pin of maintenance of the leaflet.

If the invention has been described with a clasp double leaflet, it can be adapted to a single fold fastener with the same length as the side member as illustrated in Figure 8. Furthermore, if plans to produce a one-piece leaflet by machining, the invention also includes clasps whose leaflets are made separately then welded to the cylinder or crimped the bar 24. Many improvements can be made to this clasp as part of this invention such as defined by the claims.

Claims (9)

1. Folding bracelet clasp comprising a central longitudinal member (10) of which one of the ends is articulated to a pair of outer folding members (20, 21) or a single folding member (20, 21, 24) formed as shafts so that this or these folding members, when closed, can be placed about the central longitudinal member, this or these folding members being connected at one of the end or ends by a securing pin of a bracelet section (1) or by a supporting cylinder (24) for such a pin, the other end of the central longitudinal member being articulated to another cylinder or pin, or to a second pair of outer folding members, connection of the cylinder or pin to the single folding member (20, 21, 24) or to the folding members of the pair of folding members (20, 21) being achieved by two lateral uprights (22) forming an inverted U-shaped linkage offsetting this cylinder or pin above the plane containing the ends of the folding members, characterized in that the inverted U-shaped linkage having an elasticity such that a securing device (26) fitted to the inner face of the end of the single folding member (20, 21, 24) or of each folding member of the pair of folding members (20, 21) can engage elastically with a complementary device provided in correspondence on the outer flank of the central longitudinal member.
2. Folding clasp according to claim 1, characterized in that the lateral uprights (22) are perpendicular to the ends of the folding members (20, 21), and in that the securing members are made in the form of convex projections or concave housings (26) provided along the inner faces of the ends of the folding members, and of which the cross-section is triangular with an angle at its apex greater than 120 degrees.
3. Folding clasp according to claim 1, characterized in that the lateral uprights (22') are oblique relative to the ends of the folding members (20, 21) so as to hold the cylinder (24) beyond the said ends, and in that the securing devices are made in the form of convex projections or concave housings (26) provided along the lower edges of the inner faces of the ends of the folding members, and of which the cross-section is a regular trapezium.
4. Folding clasp according to claim 3, characterized in that the uprights (22) have a parallel groove (23) between the projection or housing (26'') and the cylinder (24).
5. Folding clasp according to one of the preceding claims, characterized in that the cylinder or pin (24) has a central notch (25) or a pair of lateral notches (27, 29).
6. Folding clasp according to one of the preceding claims, characterized in that the longitudinal member (10), formed of a single piece or of two parallel blades (16, 18), has a central cut-out (15).
7. Folding clasp according to one of the preceding claims, characterized in that the longitudinal member (10) is formed of two parallel blades (11, 13) the spacing of which is adjusted by one or more transverse screws (30).
8. Folding clasp according to one of claims 1 to 6, characterized in that the longitudinal member (10) is formed of two parallel blades (11, 13) held apart by two pivots (48), it being possible for their ends to be gripped together as required by transverse screws (40), causing the central part of the blades to move apart.
9. Folding clasp according to claim 6, characterized in that the cut-out has a V-shaped part 52 in which a wedge 60 is forced to a greater or lesser degree, for example by means of a screw 70 passing through the wedge through a tapped hole 68 and bearing against the end 72 of the cut-out facing the V-shaped part.

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