US3445900A - Bracelet clasp - Google Patents

Description

E. CURRAT BRACELET CLASP May 27, 1969 Filed Dec. 29. 1967 y 1969 E. cum 3,445,900

BRACELET CLASP Filed Dec. 29, 1967 Sheet 2 of 2 United States Patent 3,445,900 BRACELET CLASP Emile Currat, 9, Chemin tlu Centurion, 1227 Carouge, Geneva, Switzerland Filed Dec. 29, 1967, Ser. No. 694,688 Claims priority, applicatioialgwitzerland, Jan. 6, 1967,

Int. Cl. A44b 21 /00 US. CI. 24-71 7 Claims ABSTRACT OF THE DISCLOSURE Bracelet clasp made of three elements pivoted one to the other and able to be folded over one over the other in order to become superimposed in closed position, the extreme elements having a U-shaped cross section fitted with adjustable securing means on one of the extremities of the bracelet.

This invention relates to a clasp for a bracelet.

It has already been proposed to dispose a spring in a clasp, a spring which ensures automatic adjustment of the bracelet by extension. The spring however has for drawback to exert a variable tension according to whether it is more or less compressed or tensed and to cause an elastic compression of the wrist of the wearer. Additionally, there is actually a tendency of using clasps of this type as a curb-chain or halbert pendant from the watch, and it is important in this case that the length of the two arms of the bracelet linking the extremities of the clasp of the watch are equal in order that the clasp remain centered on the wrist.

Additionally, an adjustable securing device preferably must not harm the leather of the bracelet and leave behind visible traces when the bracelet is extended.

The invention precisely has for its object a bracelet comprising three elements pivoted to one another, and able to be folded one on the other in order to become superimposed in closed position, the extreme elements, of perpendicular cross section, having a U shape and adjustable fastening elements for one of the extremities of the bracelet, characterized by the fact that said means are constituted by a member fast on the bracelet and comprising a locking device cooperating with the lateral walls of the extreme element corresponding to that view and arranged in such a way that said member be retained by the said lateral portions in locked position and can be moved relative to its walls in unlocked position.

The accompanying drawing represents by way of example one modification of a clasp according to the invention.

FIGURE 1 shows a longitudinal cross sectional view of an open clasp.

FIGURE 2 shows a longitudinal cross sectional view of the clasp in closed position.

FIGURE 3 shows a cross sectional view along IIIIII of the clasp shown in FIGURE 2.

FIGURE 4 shows a partial view of a plan of the clasp showing the bracelet fastening device.

The clasp shown on the drawing comprises essentially three elements 1, 2 and 3 connected together by two joints 4 and 5 in order to be placed one after the other by moving away elements 1 and 3, (FIGURE 1) or folded one on top of the other in closed position (FIGURE 2). Element 1 is constituted by a slightly curved metallic plate having a U-shaped perpendicular cross section, the wings 1a and 11; (FIGURE 3) of which are particularly curved in order to form a concave inner wall forming a housing in which engages, by elastically deforming these extremities element 3 of a similar shape as element 1 but with smaller walls 2a and 2b. Intermediate element 2 is con- 3,445,900 Patented May 27, 1969 stituted by a plate curved like elements 1 and 3, and Whose extremities wind around two shafts 6 and 7 secured respectively between the walls of elements 3 and 1, in order to form two hinges for pivoting the three elements of the clasp. Walls 2a and 2b have additionally a boss 30, 31 respectively, cooperating with parts 1a and 1b to ensure fastening of parts 1 and 3 by engagement.

The securing members of the extremities of the bracelet are shown (FIGURE 1) at 8 and 9 without the bracelet, that is to say before the fastening of the bracelet to the a clasp. These fastening members are constituted by a plate folded in U in order to form a pliers, the wings of which are slightly open in order to permit easy introduction of the extremity of the bracelet. The bracelet once introduced in the pliers, the two wings thereof are tightened and riveted together through the bracelet, a pair of holes 10 and 11, 13 and 14 respectively, being provided for this purpose (FIGURE 2).

FIGURE 4 shows in plane view one of these fastening members of which one of the wings has been removed from the plate to make appear the locking mechanism constituted of three parts, that is a plate 15 welded on wing 9a of pliers 9 and cut to form in its middle a housing 15a with a projection 15c and forming with wall 9b of the pliers 9 a slide for a slider 16 having a rectangular space 16a in which engages projection 150 to hold back the slider 16. The third part of the locking device is constituted by a cam 17 having a half moon shape cut from a metallic plate and having a middle slot 18. This cam can turn around its shaft in the housing defined by the two wings of part 9, cut out 15a and wall 911. In each of the wings of part 9 is made a circular opening 19 having a diameter smaller than the diameter of cam 17 and approximately equal to the length of slot 18 permitting one to actuate the cam by introducing a screwdriver or any other similar tool is slot 18. In the position shown in the drawing, the rectilinear flank of the cam is in the axis of the bracelet, leaving free a space between the heel of the slider 16 and the cam permitting movement to this slider. By turning counter-clockwise cam 17 it will strike against the heel of slider 16 and maintain it in spaced position. In order that the cam remains in this position in spite of the pressure exerted by the slider, the latter has a flat section 17a which comes to place itself parallel to the heel of the slider when the cam is turned by In unlocked position, as shown in the drawing, flat section 17a is parallel to wall 9b of piece 9. During passage of the cam from the position shown in the drawing to locked position, its circular part comes to rub against wall 9b, friction prevents all play of the cam in its lodging. The outer end of slider 16 and the opposite end of piece 15 have teeth, 20 and 21, respectively, the flanks of the teeth being inclined at 45 relative to the direction of movement of the slider. These teeth engage in two teeth 22, 23 respectively, made on each of the lateral walls of element 3. These teeth also have flanks inclined at 45", but a pitch equal to half the pitch of teeth 20 and 21.

In the unlocked position shown in FIGURE 4, slider 16 can move by a simple traction on the bracelet, freeing this fastening device and permitting the adjustment of the length of the bracelet. The locking takes place later by simple rotation of the cam. All that has been said for fastening member 9 goes for fastening member 8 which cooperates with teeth 24 and 25 made in the lateral walls of piece 1.

Since cam 17 can be actuated from the two sides of the fastening element, it should be noted immediately that the fastening member can be used on one side or the other and that the bracelet can be turned over, the locking then taking place by clockwise rotation of the cam.

In order to avoid complete disconnection of the extremities of the bracelet from the clasp, risking to accidentally cause loss of the watch or the clasp, safety means are provided at each extremity of the clasp for preventing fastening elements 8 and 9 from coming out of their corresponding elements. Member 8 is retained by a spring barrette of a known type comprising a cylinder 26 in which slides a shank 27 urged by a helical spring housed in the cylinder. This barrette is placed after the introduction of member 8 in part 1 and cooperates with the curved extremity 1c of piece 1. As for the fastening element 9 it comes to stop against two small legs 28 and 29 made integrally by cutting and folding with element 3 of the clasp. To introduce the bracelet in element 3 it suffices to place fastening member 9 in front of small legs 28 and 29 and to pinch slightly the bracelet which engages automatically while assuming its normal shape under legs 28 and 29.

In a modification, it is possible to have teeth on only one side the other side of the locking device being smooth and simply coming to bear against the untoothed wall of the corresponding element of the clasp.

In summary, the clasp according to the invention has a very vast adjusting zone since it corresponds nearly to twice the length of the clasp, a great security and the possibility of adjusting the position of the clasp relative to the watch.

What is claimed is:

1. A clasp for a bracelet comprising three elements hinged one to the other, foldable on one another, and superimposable for the closed position of said clasp, the outer elements having lateral walls and a perpendicular cross section in the form of a U and adjustable securing means for one of the extremities of the bracelet, said means including a fastening member on said bracelet and comprising at least one slider perpendicularly slidable relative to said lateral walls of one of said elements and an eccentric for maintaining said slider against one of said lateral walls in the locked position of said clasp.

2. Device according to claim 1, wherein said member comprises a fixed part acting against said slider and having an outer end bearing against the opposite lateral wall of the corresponding element.

3. Device according to claim 2, wherein said outer end of said slider and said part are similarly shaped in order to engage in said lateral walls.

4. Clasp according to claim 2, wherein said eccentric consists of a half moon shaped plate turning in a housing limited partially and circularly by a cut out in said part.

5. Device according to claim 4, wherein said part extends through said member and has a projection engaging in a space of said slider for retaining said slider.

6. Clasp according to claim 5, wherein said slider, said part and said eccentric are housed in a plate folded in the form of a winged U, the extremity of said bracelet being secured between the wings, said plate having an opening above said eccentric for actuating the same.

7. Clasp according to claim 6, wherein said eccentric has a central slot and each of the surfaces of said U-shaped piece has an opening for permitting actuation of said eccentric from both sides of said fastening member.

References Cited UNITED STATES PATENTS 1,756,769 4/1930 Tost. 1,985,836 12/1934 Prestinari. 2,363,590 11/1944 Holrnquist.

DONALD A. GRIFFIN, Primary Examiner.

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