WO2008071750A1

WO2008071750A1 - Tweezers with interchangeable tips

Info

Publication number: WO2008071750A1
Application number: PCT/EP2007/063846
Authority: WO
Inventors: Anton Walliser
Original assignee: Manufactures D'outils Dumont Sa
Priority date: 2006-12-13
Filing date: 2007-12-12
Publication date: 2008-06-19

Abstract

The invention relates to tweezers (2) having two arms and an interchangeable tip (2) attached on one arm by a clips. The tip is connected to a locking member, such as a metal sheet, capable of elastic deformation for the clips attachment to one longitudinal end of the arm. Guiding is provided by a rib co-operating with a groove. Advantages: precise attachment and possibility to quickly replace the tips.

Description

Tweezers with interchangeable tips

Technical area

The present invention relates to tweezers with interchangeable tips.

State of the art

Many different tweezers exist to meet the requirements of precision in areas such as cosmetics, watchmaking, jewelery, medicine or the electronics industry, where it is necessary to grasp, hold and examine very small objects.

The tips of tweezers, however, tend to dull and need to be replaced. Moreover, machining multiple forms of tweezers that are often distinguished only by the tip is expensive.

For these reasons, we know in the state of the art modular tweezers whose tips are interchangeable. It is thus possible to replace them while keeping the arms. It is also possible to produce a limited number of different types of arms to obtain a wide range of tweezers by equipping them with different tips.

FR2265499 describes tweezers whose interchangeable tips are attached to the arms by screws or rivets. This connection allows precise positioning, but does not allow a quick and convenient replacement of spikes. In addition, the additional fastening elements weigh down the end of the tweezers which become more difficult to handle.

US36771 12 discloses plastic tweezers with tips pushed into an orifice of the clamp arm. This solution, however, only applies to plastic tongs that do not allow the manufacture of precision tweezers. Brief summary of the invention

An object of the present invention is to provide tweezers free from the limitations of known tweezers.

In particular, an object of the present invention is to provide tweezers for easy and accurate tip replacement, preferably without tools.

According to the invention, these objects are achieved in particular by means of tweezers, in particular metal tweezers, with at least one interchangeable tip fastened by clipping. The tweezers arm and the tip are mutually aligned by means of a rib engaged in a groove. Clipping is performed by elastic deformation of a locking pin connected to the tip. This type of solution has the advantage of requiring no screws or rivets for assembly, while ensuring good accuracy of the assembled tips.

Clipping is preferably carried out essentially by deformation of the locking piece, which may advantageously be made of a different material of the tip and / or the arm to facilitate this deformability. The realization of the tip in two integrally bonded parts also facilitates the machining of the removable tip.

Alternatively, the clipping is performed by bending said locking member about an axis parallel to the plane of the arm, for example by lifting the piece during the insertion of the tip. In another variant, the locking piece has lateral edges covering at least part of the thickness of the arm; clipping being effected by deformation of at least one of these two side edges, preferably by spacing the two edges from each other during the insertion of the tip. Brief description of the figures

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which:

Figure 1 illustrates a perspective view of a tweezers arm equipped with a tip fixed by clipping, the locking piece being mounted.

Figure 2 illustrates a perspective view of a tweezer arm equipped with a clip-on tip, the locking piece being removed for illustration. (In a preferred embodiment this locking piece is not removable)

Figure 3 illustrates a perspective view of a tip of tweezers intended to be fixed by clipping.

Figure 4 illustrates a cross-sectional view of the assembly portion of a tweezers arm.

Figure 5 illustrates an exploded side view of a tweezer arm portion with a tip and a locking member according to a variant of the invention.

Example (s) of embodiment of the invention

In the rest of the application, tweezers are understood to mean a clamp provided with two arms and actuated by hand to grip objects, generally delicate objects. Clipping (or snapping) is understood to mean fastening parts by elastic deformation; clipping is performed by deforming at least one piece with increasing force to a locking threshold from which the pieces themselves reach a stable locking position. Clipping a part often produces a characteristic noise when the deformed parts are released by reaching the locking threshold. Moreover, in the rest of the text, the tweezers define the front of the tweezers; the back corresponds inversely to the hinge not shown between the two arms. The top and bottom refer to the figures.

The pair of tweezers described by way of example comprises two arms 1, only one of which is shown in FIGS. 1 to 3. The arms are bonded to one another, for example by welding or clipping, and have sufficient elasticity to allow the closing of the points 5 in order to grasp an object. The arm is connected to the tip by means of a locking piece 3 described below and which covers most of the assembly elements

The figures illustrate a straight arm and a pointed tip; the invention applies to other forms of arms and spikes. The arm is preferably of metal, for example steel, while the tip is of hard or flexible material, such as steel, ceramic, carbon fiber and various plastics.

The front end of the arm 1 near the tip ends in a prominent assembly portion 10 visible in particular in Figure 2. This figure shows tweezers which would have removed the locking piece 3; in a preferred embodiment this piece is however not separable from the tip 5. The rear end of the tip ends in turn in an assembly portion 50 cooperating with the assembly portion 10 of the arm.

The assembly portion 10 is sandwiched into the housing formed between the locking piece 3 and the connecting portion 50 of the tip. In this example, the assembly portion 10 of the arm is therefore "male", that is to say substantially convex, while the "female" tip forms with the part 3 a housing for the arm. It is however possible within the scope of the invention to reverse this arrangement and insert a tip with a male assembly portion in a female arm. In the figure, the assembly portions 10 of the arm and 50 of the tip are dovetailed, that is to say that their cross sections are progressively reduced towards the front. Other forms of assembly portions 10, 50 can be employed, including cylindrical shapes with circular or polygonal sections.

The assembly portion 50 of the tip defines in this example a bearing surface 54 (Figure 3). The arm 10 has a corresponding bearing surface 16 (Figure 2) which rests on this bearing surface 54 so as to define the relative positioning in a direction perpendicular to the plane of the arm. The bearing surface 54 of the tip is traversed by a longitudinal rib 51 which engages in a corresponding groove 1 1 (Figure 4) under the assembly portion 10 of the arm. The rib can slide into the groove when mounting the tip. The rib 51 and the corresponding groove January 1 provide lateral positioning of the tip on the arm. It is also possible in the context of the invention to employ two ribs engaged in two grooves, or ribs on the arm engaged in ribs on the tip, or use any other form of rib and groove or equivalent slide to accurately determine the lateral position of the tip on the arm.

Thanks to the rib, the portion 10 can only slide along the longitudinal axis of the tweezers. The bearing surface 54 and the lower face 16 of the assembly portion 10 are precision machined from a suitable material, for example a hard material such as steel, to ensure precise positioning along all the other axes. Non-flat or non-rectilinear bearing surfaces may be employed.

The assembly portion 10 of the arm is inserted to the bottom of the housing, that is to say until the end of the arm 1 reaches a stop against a transverse bearing surface 55 (FIGS. 3) of the tip. During the insertion, the locking piece 3 is deformed by bending about an axis parallel to the plane of the arm, so as to lift to allow the passage of the arm. The longitudinal position is determined at the end of the stroke by the elements 7, consisting of bushings or any other clipping element. The locking of the arm at the bottom of the housing in the tip is obtained thanks to the locking piece 3 closing in this example the upper face 33 and the two side faces 34 of the housing. It would also be possible to use a different locking piece, for example a lid locking piece which would only cover the upper face over the assembly portion 10 of the arm.

In this example, the locking piece 3 consists of a metal sheet of uniform thickness that is folded or machined with an inverted U-shaped profile. It is inextricably linked to the tip. In a preferred embodiment, the part 3 is welded or glued to a bonding surface 52 on the tip 5. A portion 35 of the edge of the locking piece engages in abutment against a corresponding lateral surface of the tip , so as to position these two elements accurately relative to each other. Other methods of permanent or even separable attachment can be envisaged to link the tip to the workpiece 3. It is also possible to machine a point with an integrated locking portion, however the machining of the precision surfaces at the bottom of the housing would be delicate. Furthermore, the locking element must have sufficient flexibility while the tip will preferably be made of a different material. Finally, a locking piece integrally connected to the arm (rather than the tip) is possible.

The upper surface of the assembly portion 10 of the arm is provided in this example with two holes 12 (Figure 4) in which clipping sleeves 7 are driven and / or glued. The holes may be blind holes to accurately determine the insertion depth of the sockets; in Figure 4 the bottom of the hole is drilled with an opening of smaller diameter to facilitate the driving and / or removal of bushings and / or to accommodate the glue reticle. The upper surface of the bushes 7 protrudes slightly above the holes 12 so as to constitute a protrusion which is clipped into corresponding openings 32 through the locking piece. The prominent portion of the sleeves preferably has a sufficiently sloping weak to facilitate the hunting of the part 3, for example a slope less than 45 °, or a hemispherical surface.

It is also possible in the context of the invention to perform clipping using elements other than sockets, for example with male elements integral with the locking piece and which would engage in corresponding holes on the assembly portion 10. The clipped elements could also be integral with one of the parts 1, 3 or 5 instead of using driven sockets. Clipping can also be performed on side surfaces of the tip and the arm, or on any surface adapted for this purpose. Finally, the clipping could implement spiral springs or leaf springs.

The locking piece 3 has two lateral faces 34 on each side of the tweezers; these faces make it possible to hide the interstices between the portion 10 and the tip respectively the part 5. This avoids a blunt object accidentally introduced into this gap can not separate the parts. The side walls 34 can also converge towards the inner face of the arm, and contribute to the maintenance of the arm and the tip. They can also exert pressure on the beveled side surfaces of the portion 50.

In an unillustrated variant of the invention, the tip is fixed to the arm by slidably sliding and then pivoting to make it parallel to the arm and to engage a projection in an opening of the arm. The position is held by clipping when pivoting. This variant makes it possible to take up the axial forces on the tip by a different element of the clipping elements.

The mounting of a tip 5 at the end of the arm 1 is done by inserting manually or with a robot the male assembly portion 10 of the arm in the housing between the bearing surface 54 of the tip 5 and the locking piece 3 integral with the tip. The arm is guided during this displacement by the sliding of the rib 51 in the corresponding longitudinal groove 1 1. By continuing the longitudinal thrust, the wafer 37 at the rear of the locking piece 3 comes into contact with the two sockets 7 projecting above the portion 10. These sockets tend to slightly lift the locking piece 3 which deforms elastically; the user clearly perceives that the force necessary for the introduction of the arm increases.

The locking piece 3 continues to lift until the bushes 7 reach the holes 32 through the locking piece 3. At this moment the piece 3 folds sharply in order to resume its undistorted rest position. ; the protruding portions of the sockets 7 penetrate into the holes 32. During this operation, the arm 1 continues to advance very slightly with respect to the tip 5, until the longitudinal end of the arm reaches an abutment against the surface transverse support 55 of the tip.

In a preferred embodiment, the height of the housing between the bearing surface 54 and the inner face of the portion 33 is slightly less than the thickness of the assembly portion 10 of the arm. The arm can only be introduced into this housing by slightly deforming the locking piece 3 which thus exerts a vertical force tending to press the assembly portion 10 against the bearing surface 54.

Disassembly is done in the opposite direction by pulling the arm 1 towards the rear of the tip 5. In order to disengage the two sockets 7, an unlocking opening 13 is preferably milled on the upper face of the arm 1; this opening makes it possible to insert a tool, for example a small screwdriver, to lift the part 3 and thus free the arm.

It is possible to clip other utensils at the end of the arms

1, for example arm extensions. It is also possible in the context of the invention to provide several successive clipping positions in the longitudinal direction, so as to allow several fixing positions and to lengthen the tweezers by fixing the tip further. For example, the length of the assembly portion 10 is between 10 and 20 millimeters, for example 13 millimeters, to ensure sufficient transverse support. The thickness of this portion is between 1.0 and 1.5 millimeters, for example 1.3 millimeters. The thickness of the corresponding assembly portion 50 of the tip is preferably between 0.8 and 1.2 millimeters, which makes it possible to obtain sufficient rigidity without unnecessarily increasing the thickness of the tip of the tweezers. The thickness of the portion 50, which is reinforced by a rib 51, may however be less than the thickness of the portion 10 weakened by the corresponding groove 51. The width of the assembly portion 50 increases between 4 millimeters (± 1) near the tip up to 6 ± 1 millimeters at the rear end. The height of the rib is a few tenths of a millimeter, for example 0.4 millimeters.

FIG. 5 illustrates an exploded view of an arm 1 'of tweezers according to another variant of the invention, with a tip 5' adapted to this arm and a corresponding locking piece 3 '. In this variant, the rear end 50 'of the tip 5' is sandwiched between the end 10 'of the arm and a locking piece 3' integrally bonded to the tip, for example by gluing or welding. Guiding is performed using a rib 11 'of triangular section on the arm, cooperating with a corresponding groove not shown on the tip. Clipping is performed by elastically deforming the side walls 34 'of the locking piece 3' during the insertion or extraction of the tip. The tip is held by means of the male portions 340 'on the inner faces of the lateral edges 34' which engage in locked position in female portions 17 'corresponding to the side edges of the arm 1'.

The tweezers of the invention are particularly suitable for use with disposable tips, for example disposable tips used for example in the medical field to prevent contamination. Reference numbers used in the figures

I Bras

3 locking piece

5 Tip

7 Sockets

10 Arm Assembly Portion

I Longitudinal groove

12 Holes for driving bushings

13 unlocking opening

16 Lower bearing surface of the arm assembly portion

17 Female clipping element

32 holes for clipping bushings

33 Upper part of the locking part

34 Side part of the locking piece 340 Male clipping element

35 Portion of the wafer in contact with the tip 37 Slice on the back of the locking piece

50 Portion of assembly of the tip

51 Longitudinal rib

52 Surface for bonding the locking part

53 Lateral contact surface with the locking piece

54 Support surface of the assembly portion of the tip

55 Crossing surface of the tip

Claims

claims

1. Metal tweezers comprising two arms (1) and at least one interchangeable tip (5) fixed on one end of one of said arms (1) by clipping, characterized in that the arm and the tip are mutually aligned by means of a rib (51) engaged in a groove (1 1), and in that the clip is made by elastic deformation of a locking pin (3) connected to the tip (5).

2. Tweezers according to claim 1, said locking piece

(3) being distinct but inseparably linked to said tip (5).

3. Tweezers according to one of claims 1 to 2, wherein said arm (1) and / or said tip (5) has at least one opening (12) in which a clipping member (7) is driven or glued.

4. Tweezers according to one of claims 1 to 3, a portion (16) of said arm (1) being pressed against a portion (54) of the tip in a first material by the deformation of a workpiece (3) made in another material.

5. Tweezers according to one of claims 1 to 4, the clipping being performed essentially by deformation of said locking piece

(3).

6. Tweezers according to one of claims 1 to 5, the clipping being performed by bending said locking member (3) about an axis parallel to the plane of said arm.

7. tweezers according to one of claims 1 to 5, the clipping being performed by deformation of at least one side edge (34) of said locking piece (3 ').

8. Tweezers according to one of claims 1 to 7, said end (10) of the arm (1) being sandwiched between a portion (50) of the tip (5) and said locking piece (3).

9. Tweezers according to one of claims 1 to 7, the tip being sandwiched between said end (10) of the arm (1) and said locking piece (3 ').

Interchangeable tweezers pin (5) intended to be fixed on an arm (1) of tweezers, characterized by portions (32) allowing clipping on said arm (1), the tip comprising a groove or a rib (51) longitudinal for the alignment of said arm (1).

1. Tweezers tip (5) according to claim 10, integrally bonded to a locking element (3) elastically deformable and having said portions (32) for clipping.

12. Tweezers tip (5) according to one of claims 10 or 1 1, said portions (32) being constituted by one or more holes for clipping a male member (7).

13. Tip of tweezers (5) according to one of claims 10 or 1 1, said portions being constituted by one or more male elements intended to be clipped into a hole.

14. Tweezers tip (5) according to one of claims 10 to 13, said locking member (3) elastically deforming to ensure clipping.

15. Tweezers tip according to one of claims 10 to 14, said locking member (3) being glued or welded to the tip.

16. Tip of tweezers (5) according to one of claims 10 to 15, an assembly portion (50) of said tip (5) forming with said locking member (3) a housing for accommodating an end (10) of said arm (1).

17. tweezers tip (5) according to one of claims 10 to 16, said locking member (3) being made of a material different from said tip (5).

18. Tip of tweezers (5) according to one of claims 10 to 17, integrally connected to a locking member (3) so as to form a housing for sandwiching an assembly portion (10) of said arm (1). ) tweezers, said locking member (3) being provided with one or more holes (32) for clipping, said locking member (3) elastically deforming to clip a male member (7) in each of said holes, the tip (5) being provided with a longitudinal rib (51) for aligning said arm (1) in said housing.

19. Tip of tweezers (5) according to one of claims 10 to 17, integrally linked to a locking member (3) for covering one end of the tip (5), the clipping being effected by deformation of said locking member .