EP0935507B1 - Method for making blanks for parts of pliers - Google Patents

Description

The present invention relates to a process for manufacturing metal blanks bit or branch kernels pliers comprising a jaw.

Current manufacturing techniques for metal parts of pliers, namely the jaws of pliers and work heads and / or branches of other types of pliers, impose to manage an expensive and complex tool fleet. These techniques known are indeed forging or cutting / stamping of flat sheets (JP-A-6 076 235).

The invention aims to allow the industrial production of wide ranges of pliers with reduced tools, and therefore particularly economic.

To this end, the manufacturing process according to the invention, as defined in claim 1, is characterized in that one cuts the outline of each blank in a section of profile of respective shape of variable thickness whose cross-section transversal corresponds to at least one section overall longitudinal of the draft.

Preferably, this process can include one or more features of claims 2 to 10.

The invention also relates to a method manufacturing a half-clamp, according to claims 11 and 13, using the method of the invention. Following a first variant, a blank is produced as described above which has a pliers branch core, and we overmold a handle of pliers on this core. Advantageously, in this case, the overmolding mold is closed on a adapter ring threaded onto the branch core.

According to a second variant, we realize as described above, above a draft which includes a pliers branch core, we introduce with play the branch core in a cavity of a preformed handle, and we fill the remaining free space in this cavity a filling material. Said cavity can in particular lead forwards and laterally.

• la Figure 1 représente en perspective une ébauche de mors de pince multiprise réalisée conformément à l'invention;
• la Figure 2 représente en perspective un profilé de forme à partir duquel l'ébauche de mors de la Figure 1 est réalisé;
• la Figure 3 représente la section de ce profilé;
• la Figure 4 illustre en perspective la découpe d'ébauches telles que celle de la Figure 1 dans ce profilé;
• la Figure 5 représente schématiquement, en coupe longitudinale, une branche de pince multiprise équipée d'un mors obtenu à partir de l'ébauche de la Figure 1;
• la Figure 6 illustre la découpe d'ébauches d'un membre de pince dans un profilé de forme conformément à l'invention;
• la Figure 7 représente la section du profilé de forme;
• les Figures 8, 10, 12, 14 et 16 sont des vues analogues à la Figure 6 mais relatives à d'autres profilés de forme;
• les Figures 9, 11, 13, 15 et 17 représentent les sections respectives de ces profilés de forme;
• la Figure 18 représente en perspective une ébauche de membre de pince obtenue à partir de l'un quelconque des profilés des Figures 8 à 15;
• la Figure 19 représente en perspective une ébauche de demi-pince réalisée conformément à l'invention;
• la Figure 20 représente en perspective un profilé analogue à celui des Figures 14 et 15;
• la Figure 21 illustre la découpe d'ébauches de deux membres de pince différents dans ce profilé;
• la Figure 22 représente en perspective un profilé de base à section rectangulaire;
• la Figure 23 illustre le forgeage de. tronçons localisés de profilé de forme dans ce profilé de base, ainsi que la découpe d'ébauches de demi-pince dans ces tronçons localisés;
• la Figure 24 représente en perspective l'ébauche ainsi obtenue;
• la Figure 25 représente en perspective un profilé de base à section circulaire;
• la Figure 26 illustre le forgeage de tronçons localisés de profilé de forme dans ce profilé de base;
• la Figure 27 illustre la découpe dans ces tronçons localisés d'ébauches de membre de pince;
• la Figure 28 représente en perspective une autre ébauche de membre de pince réalisée conformément à l'invention et usinée pour constituer un membre de pince;
• la Figure 29 représente en perspective le membre de pince correspondant, sur lequel une poignée de pince a été surmoulée;
• la Figure 30 représente en perspective le même membre de pince et une bague rapportée;
• la Figure 31 représente le même membre de pince équipé de la bague rapportée et sur lequel une poignée de pince a été surmoulée;
• les Figures 32 et 33 montrent schématiquement, en coupe longitudinale, deux variantes de la demi-pince de la Figure 29;
• la Figure 34 illustre en perspective un autre mode de réalisation d'une demi-pince à partir du membre de pince de la Figure 28;
• la Figure 35 est une vue en plan correspondante; et
• la Figure 36 est une vue en plan, partiel-. lement en coupe, montrant la demi-pince terminée.

Examples of implementation of the invention will now be described with reference to the accompanying drawings, in which:

• Figure 1 shows in perspective a blank of multi-grip pliers jaws produced in accordance with the invention;
• Figure 2 shows in perspective a shaped profile from which the jaw blank of Figure 1 is made;
• Figure 3 shows the section of this profile;
• Figure 4 illustrates in perspective the cutting of blanks such as that of Figure 1 in this profile;
• Figure 5 shows schematically, in longitudinal section, a branch of pliers equipped with a jaw obtained from the blank of Figure 1;
• Figure 6 illustrates the cutting of blanks of a clamp member in a shaped section according to the invention;
• Figure 7 shows the section of the shape profile;
• Figures 8, 10, 12, 14 and 16 are views similar to Figure 6 but relating to other shaped profiles;
• Figures 9, 11, 13, 15 and 17 show the respective sections of these shaped sections;
• Figure 18 shows in perspective a clamp member blank obtained from any of the profiles of Figures 8 to 15;
• Figure 19 shows in perspective a half-clip blank produced in accordance with the invention;
• Figure 20 shows in perspective a profile similar to that of Figures 14 and 15;
• Figure 21 illustrates the cutting of blanks of two different clamp members in this profile;
• Figure 22 shows in perspective a base profile with rectangular section;
• Figure 23 illustrates the forging of. localized sections of shape profile in this base profile, as well as the cutting of half-clamp blanks in these localized sections;
• Figure 24 shows in perspective the blank thus obtained;
• Figure 25 shows in perspective a basic profile with circular section;
• Figure 26 illustrates the forging of localized sections of shape section in this base section;
• Figure 27 illustrates the cutting in these localized sections of clamp member blanks;
• FIG. 28 shows in perspective another blank of gripper member produced in accordance with the invention and machined to constitute a gripper member;
• Figure 29 shows in perspective the corresponding clamp member, on which a clamp handle has been molded;
• Figure 30 shows in perspective the same clamp member and an attached ring;
• Figure 31 shows the same clamp member equipped with the attached ring and on which a clamp handle has been molded;
• Figures 32 and 33 schematically show, in longitudinal section, two variants of the half-clamp of Figure 29;
• Figure 34 illustrates in perspective another embodiment of a half clamp from the clamp member of Figure 28;
• Figure 35 is a corresponding plan view; and
• Figure 36 is a plan view, partially. in section, showing the half clamp finished.

There is shown in Figure 1 the blank 1 of a one-piece jaw intended to equip the protruding branch with a multi-grip pliers. This blank consists of a jaw 2 of constant large thickness E, typically of the order of 9 mm, and of a fixing heel 3 of constant thickness e much smaller, typically of the order of E / 2 , or about 4 mm. An intermediate bead 4 is provided between the jaw and the heel. The blank is symmetrical with respect to its median plane P.

Heel 3 is delimited, on each face, by a straight shoulder 5, substantially perpendicular at plane P. At its root, heel side, shoulder 5 is bordered by a straight clearance groove 6. De the other side, the shoulder 5 connects to a short flat surface 7 parallel to plane P, then joins the jaw root 2 by an inclined face 8. The angle α of this inclined face with the perpendicular to the plane P is preferably at least equal to 30 °, and for example close to this value. Furthermore, heel 3 is crossed by a wide oblong cutout 9 rounded ends.

A succession of blanks 1 is produced from a profile of shape 10, obtained by extrusion, shown in Figures 2 and 3. This profile has the same section as the blank 1 when looking at the shoulders 5 at the end Thus, using the same reference numbers as above, it consists of a part 2 with rectangular section, of constant thickness E, of a part 3 with rectangular section, of constant thickness e , and, between these two parts, part 4 in excess thickness. The latter presents, on the side of the game. 2, two faces 8 inclined at the above angle α; on the other side, it has two faces 5 perpendicular to the median plane P, each bordered by a clearance groove 6. The faces 8 and 5 are connected on each side by a face 7 parallel to the plane P.

So, as shown in Figure 4, it is possible to obtain in a single cutting operation profile 10, made perpendicular to the plane P, a succession of sketches 1, following the contours repetitive 11 indicated. We use of course for that a matrix and a three-dimensional punch marrying each the shape of a face of the profile. It is to highlight that the presence of the grooves 6 provides good support plan on the faces of part 3, up to the shoulders 5, while the inclination α of the faces 8 facilitates the profile centering and obtaining good quality cutting.

The assembly is shown in Figure 5 jaw 12, consisting of the blank 1 machined in the active region 13 (Figure 1) of jaw 2, with two sheet metal parts 14, 15 of elongated shape, flat in their front region, which surround the heel 3, to achieve the protruding branch 16 of a pliers.

Each piece 14, 15 ends, at the front, by a straight edge 17 which rests on the shoulder 5 corresponding all along it. This support, which is made reliable by the presence of the grooves of clearance 6, allows the clamping forces to be taken up when using the tool. Each piece 14, 15 further comprises two orifices 18 which each fit in an end round 19 of the cutout 9, as shown in phantom in Figure 1. The assembly parts 12, 14 and 15 is produced using two rivets 20 which pass through these orifices 18 as well as the cutout 19. During their compression, the rods of the two rivets swell, which presses them firmly against the rounded edges 19.

Figures 6 and 7 show the realization by simply cutting out a series of one-piece members of clamp 21 in. a 10A shape profile.

Each member 21 forms a half-mesh, or articulation half-zone, 22, provided with an orifice 23 for the passage of the hinge pin of the clamp; on the one hand from this area, a jaw 24 of the forceps; and on the other next to zone 22, a branch nucleus 25. In the example shown, the jaw 24 is of the beak type Universal pliers.

The profile 10A has, in section, three successive parts of increasing thickness: one thick part 24 jaw side, an intermediate part 22 corresponding to the half-mesh, and a thin part 25 corresponding to the branch core. On one side (the upper face in Figure 7), the profile is flat on all the parts 22 and 25, and an inclined face 8A along the aforementioned angle α connects this plane to the plane face parallel of part 24. On the other side, the profile is flat on all parts 22 and 24, and one side 5B inclined at an angle β preferably at least equal to 30 °, for example equal to α, connects this plane to the face parallel plane of part 25.

As shown in Figure 6, a succession of members 21 are obtained by simple cutting 10A profile, with their main direction substantially perpendicular to the length of the profile.

In the variant of Figures 8 and 9, the profile 10B has two thin side portions 26 of same thickness, and a thicker central part 27. It is flat on the whole of one of its faces, and on the other side, the part 27 is bordered by two faces 8C inclined at the angle α. The flat underside allows the use of a flat cutting die.

By simple cutting, we realize from profile 10B a succession of clamp members 21A similar to that of Figures 6 and 7 but in which the parts 22 and 25 have the same thickness. The members 21A are cut head to tail, with the jaws 24 nested into each other in central region 27 of profile.

Same 21A members can be cut in the profile 10C shown in Figures 10 and 11, which has a thin central part 26 and two thick side parts 27. Again, the profile has a completely flat face. In this case, the nozzles 24 are cut in parts 27, and these are the zones 22, 25 which are arranged upside down in the part central 26.

Figures 12 and 13 illustrate a variant very close to the previous one. However, the area central 26 of profile 10D is wider, which allows to bring together the blanks 21A to each other cut.

The variant of Figures 14 and 15 is similar to that of Figures 6 and 7, except that the zones 22 and 25 of profile 10E have the same thickness, which allows to give the profile 10E a completely face plane. The members obtained are of type 21A.

Variant 10F in Figures 16 and 17 does not differs from that in Figures 6 and 7 only in that the lower inclined face 8B is plumb with the upper inclined face 8A. 21B members obtained by cutting this profile 10F therefore differ correspondingly of the members 21.

Figure 18 shows in perspective a gripper member blank 21A obtained by cutting the profile 10B, 10C, 10D or 10E. This draft includes a flat face and, on the other side, a change in thickness progressive 28 at the root of its beak 24.

By increasing the length of the or each part of the profile corresponding to the branch core 25 (part 25 of Figures 6 and 7, part (s) 26 of the Figures 8 to 17), it can be done in the same way, by simple cutout, a half-clip blank 29 such as that shown in Figure 19. This does not differ from the blank 21A of FIG. 18 only by extending the core 25 into a whole half-branch core 30.

Not only the cutting process described above allows to realize industrially at large rate, and precisely and economically, a draft given, but still it allows, from the same profile, to produce a whole range of sketches, which, for example, differ from each other only in the form of the working head.

Thus, Figure 20 represents a 10G profile similar to that of Figures 14 and 15, and Figure 21 shows that from this profile, we can cut either a universal clamp member blank 21A such that that of Figure 18, a draft member 21C of round nose pliers. Of course, one can imagine many other configurations of blanks made at from the same shape profile. Global tools making it possible to manufacture a range of pliers is therefore particularly economical.

Management of a fleet of shaped profiles can even be completely deleted if you start from a basic section with simple section in which we realize by forging, cold or hot, a succession of shaped profile sections in each of which there is a cutout, which is made in one step higher.

Thus, in the example of Figures 22 and 23, we start from a basic section or strip 32 with a cross-section rectangular, whose thickness is the thickness maximum to be expected in the cut (i.e. the thickness E of beak 24 in the examples cited above).

This basic profile is forged in several steps (Figure 23) to form a succession of sections 10H shaped profiles in each of which fits a cutout 33, which is for example that of the blank of the universal clamp 21D in Figure 24.

• (b) réalisation d'une découpe localisée 132, à peu près au centre d'un tronçon de profilé 232;
• (c) forgeage localisé de cette découpe pour former le taillant 121 de l'ébauche;
• (d) forgeage de la partie 232A du tronçon de profilé située d'un côté de la découpe forgée 132, pour l'amener à l'épaisseur désirée pour les parties 22 et 25 de l'ébauche; on obtient ainsi un tronçon de profilé de forme 10I; et
• (e) découpe de l'ébauche 21D à taillant 121 représentée à la Figure 24.

Thus, from the rectangular profile illustrated in (a), the following steps are carried out:

• (b) making a localized cutout 132, approximately in the center of a section of section 232;
• (c) localized forging of this cut to form the cutting edge 121 of the blank;
• (d) forging the part 232A of the section of section located on one side of the forged cutout 132, to bring it to the desired thickness for the parts 22 and 25 of the blank; a section of form 10I is thus obtained; and
• (e) cutting out the blank 21D with a cutting edge 121 shown in FIG. 24.

Such a method eliminates the phase subsequent machining of the cutter 121.

Likewise, in the example of Figures 25 to 27, we start from a base section 32A with circular section (Figure 25), for example unwound from a reel, and by forging a succession of sections of 10I shape profiles (Figure 26) each consisting of a section 33 with rectangular section followed by section 34 with flat faces, of small thickness. The cutting in each section 10I (Figure 27) gives rise to a gripper member, in this example a gripper member 21E cutting. Note that in this example, the dimension longitudinal of the blank 21E is substantially parallel to the length of the profile.

Figures 28 to 36 illustrate three modes different finishing of a half clamp from a 21F clamp member blank which does not differ from the blank 21A of Figure 18 only by the presence of reliefs 36, such as notches and an orifice, on the core of branch 25. The reliefs 36 can be obtained by cut itself.

The blank having been machined in 37 in the area active beak 24, .to constitute a clamp member 39, in the example of Figures 28 and 29, the handle 38 is simply overmolded on the core 25. This handle can be aluminum, aluminum alloy, or reinforced thermoplastic or thermosetting material or not.

In the variant of Figures 30 and 31, we begins by threading by force, or at least with joint waterproof, on the core 25 a ring 40, then the mold for molding the handle on this ring. The Finished half clamp is shown in Figure 31. The ring 40 is made of a material having a some flexibility or ductility in order to adapt internally to dimensional variations of the nucleus. 25, and externally around the closed mold. This material is for example a plastic material or aluminum. The front part of the ring 40, externally enlarged, is visible at the front of the handle and extend it.

As shown in Figures 32 and 33, in variant, one can carry out on the handle 38 a second overmolding 138, forming a total coating (Figure 32) or partial (Figure 33), in a relatively flexible or "grip". We can thus obtain a whole range pliers from the same base handle 38.

In the variant of Figures 34 to 36, the handle 38, made of plastic, is produced independently by molding and has a cavity 41 which opens at its front end through an opening 42 and laterally through an opening 43 (Figure 34). The walls of the cavity 41 have reliefs 44. The core 25 of the clamp member is introduced through the opening 42 (Figure 35), then additional plastic 45 is molded in the cavity 41 to secure the two pieces (Figure 36). We can of course modify the handle in the same way as in Figures 32 and 33.

In each of the variants of Figures 28 to 36, the reliefs 36 of the clamp member, and possibly 44 of the handle, improve the grip between the two parts after overmolding.

It should be noted that the finishing modes of branch described above with reference to Figures 28 to 36 are also applicable to metallic members obtained by any other suitable process, for example by forging or cutting / stamping flat sheets.

In addition, it can, in the case of a handle. bi-injected, apply the technique described for a screwdriver handle in FR-A-2 730 658 in the name of Applicant, namely, during the last transaction of overmolding, close the mold by applying a rib of pinching of it on a step of the injected part Underlying.

Claims (14)

1. Process for manufacturing metal blanks (1; 21; 21A; ...; 21F; 29) for the nose or cores of the arms of pliers comprising jaws, characterised in that the outline of each blank is cut out from a respectively shaped profiled length (10; 10A; ...; 10I) of variable thickness, the cross section of which corresponds to at least one section along the longitudinal extent of the blank.
2. Process according to claim 1, characterised in that the shaped profiled length (10; 10A; ...; 10I) is in one piece and made of one material.
3. Process according to claim 1 or 2, characterised in that the blank is cut out from a profile (10; 10A; ...; 10I) of constant cross section.
4. Process according to claim 1 or 2, characterised in that the starting material is a basic profile (32; 32A) having a different cross section from the shaped profiled lengths (10H, 10I), localised lengths (10H; 10I) of shaped profile are produced from this basic profile by at least one forging process, and the blanks are cut out from each of these localised lengths.
5. Process according to claim 4, characterised in that the basic profile (32; 32A) is a sheet or bar of rectangular or polygonal cross section, or a profile with a cross section in the shape of a closed curve, particularly a circle, notably unwound from a coil.
6. Process according to any one of claims 1 to 5, characterised in that the shaped profiled lengths (10B; 10C; 10D; 10E; 10G; 10H; 10I) have on one side, over their full extent, a flat surface for abutting on a flat cutting die.
7. Process according to any one of claims 1 to 5, characterised in that the shaped profiled lengths (10; 10A; ...; 10I) have at least one thickness changing surface (8; 8a; 8B; 8C) which is inclined, notably by at least 30°, relative to the perpendicular to the median plane (P) of said lengths.
8. Process according to any one of claims 1 to 7, characterised in that the shaped profiled lengths (10) comprise at least one shoulder (5) substantially perpendicular to the median plane (P) thereof, the root of this shoulder being bordered in particular by a releasing groove (6).
9. Process according to any one of claims 1 to 8, characterised in that the section of the shaped profiled lengths (10D; 10C; 10D) is symmetrical in the transverse direction, and in that blanks (21A) arranged head to tail are cut out therefrom.
10. Process according to any one of claims 1 to 9, characterised in that the shaped profiled lengths (10G) are used to cut out at least two blanks of different shapes (21A, 21C).
11. Process for producing half a pair of pliers, characterised in that a blank (21F) of the core of one arm (25) of the pliers is produced according to any one of claims 1 to 10, and a handle (38) is moulded onto this core.
12. Process according to claim 11, characterised in that the overmoulding mould is closed over an adaptor ring (40) threaded onto the core of the arm (25).
13. Process for producing half a pair of pliers, characterised in that a blank (21F) of the core of one arm of the pliers (25) is produced according to any one of claims 1 to 10, the core of the arm (25) is inserted with play in a cavity (41) in a preformed handle (38), and the space left free in this cavity is filled with a filling material (45).
14. Process according to claim 13, characterised in that the cavity (41) of the preformed handle (38) opens forwards and sideways.

Images