EP0833722B1 - Ratchet spanner for turning a hexagon-head part, particularly a screw or nut - Google Patents

Abstract

PCT No. PCT/FR96/00963 Sec. 371 Date Apr. 7, 1998 Sec. 102(e) Date Apr. 7, 1998 PCT Filed Jun. 20, 1996 PCT Pub. No. WO97/00758 PCT Pub. Date Jan. 9, 1997A ratchet wrench having an open end (18) defined by front (20) and rear (22) jaws, in relation to a driving direction. The jaws are linked by an intermediate arcuate web (24). Each jaw includes an engagement surface (30, 36) for engaging the front half of a front surface (32) and a rear surface (38), respectively, of the head of a part to be turned. A projection (42) is provided on the arcuate web for engaging a bearing point (43) on an intermediate head surface (44) located immediately ahead of the rear surface (38) when no torque is applied and over the full range of applied torques. The bearing point (43) of the projection (42) is located in the front half of the intermediate surface (44). The entire arcuate web (24) is spaced apart from the head (28), except at the bearing point (43), when torque is applied as well as when no torque is applied.

Description

The present invention relates to a clicking key according to the preamble of claim 1. Such a ratcheting wrench is known, for example, from US-A-3,921,476.

We already know clicking keys, or keys fast, allowing tightening or loosening of a screw head or hexagon nut. They include a drive head with an open jaw in which is enclosed by the hexagon. In the sense of training, two opposite jaws of the jaw cooperate with opposite faces of the hexagon to drive it. In the opposite direction to the training direction, the jaws emerge from the sides of the hexagon and allow the free rotation of the key around it. The surfaces jaw drive then slide along the faces hexagon.

These keys are particularly practical and convenient since they allow actuation in one direction a hexagon, by a simple back and forth movement of the key around it, and without ever having to clear the head of the hex key completely.

The clicking key described in US-A-3,921,476 in the name of EVANS has an open jaw bounded by two jaws opposites adapted to enclose a hexagon. One of the jaws is provided with a recess for receiving an intersection edge hexagon. This recess is delimited on the bit by two bosses arranged on either side of this one. These are adapted to cooperate with areas of two adjacent faces connected by the edge received in the recess. These beaches are located very close of this edge. Therefore, when using the key, especially when applying couples raised, the hexagonal edge received in the recess is quickly deteriorated.

The object of the present invention is to provide a ratcheting key, without the disadvantages mentioned above and allowing in particular the transmission of the whole range of couples so easy and stable, with a reduced risk of slipping and deterioration of the faces and edges of the head hexagonal.

To this end, the invention relates to a key rattling as defined above, characterized by what said fulcrum of said intermediate face is located in the front half of this intermediate face.

• ladite protubérance est adaptée pour coopérer avec ladite face intermédiaire au voisinage du tiers avant de celle-ci, en considérant le sens d'entraínement, pour une tête de dimension maximale;
• la distance entre la zone de contact de la surface d'entraínement arrière avec la face arrière et l'arête avant de cette face arrière est inférieure à la distance entre le point de contact de la protubérance avec la face intermédiaire et l'arête avant de cette face intermédiaire ;
• la protubérance est venue de matière avec l'arceau ;
• il est prévu sur l'arceau, entre la surface d'entraínement arrière et la protubérance, un dégagement prolongé par une surface de liaison concave, ayant notamment un rayon de courbure inférieur ou égal à la distance entre plats de la tête, évitant tout contact entre la mâchoire et l'arête avant de la face arrière ;
• les surfaces d'entraínement avant et arrière sont des surfaces bombées ;
• le rayon de courbure de la surface d'entraínement arrière est inférieur au rayon de courbure de la surface d'entraínement avant ;
• l'angle, mesuré dans le sens d'entraínement et défini entre l'axe de rotation de la tête polygonale et les deux zones de contact entre la tête et les surfaces d'entraínement arrière et avant, est légèrement supérieur à 180° ;
• le profil de la mâchoire est formé d'une succession de portions courbes, se raccordant tangentiellement les unes aux autres, de la surface d'entraínement avant à la surface d'entraínement arrière ;
• ladite mâchoire est disposée à une extrémité d'un corps de clé, muni à son autre extrémité d'une mâchoire d'entraínement cliquetante de même type et d'une autre dimension ou d'une tête d'entraínement à oeil ;
• la mâchoire est à écartement fixe ;
• la protubérance est adaptée pour coopérer avec la face intermédiaire entre la moitié et le tiers avant de celle-ci, en considérant le sens d'entraínement, pour une tête de dimension maximale ; et
• la protubérance est adaptée pour coopérer avec la face intermédiaire sensiblement aux quatre dixièmes avant de celle-ci, en considérant le sens d'entraínement, pour une tête de dimension maximale.

According to particular embodiments, the invention may have one or more of the following characteristics:

• said protuberance is adapted to cooperate with said intermediate face in the vicinity of the front third thereof, considering the direction of drive, for a head of maximum dimension;
• the distance between the contact area of the rear drive surface with the rear face and the front edge of this rear face is less than the distance between the point of contact of the protuberance with the intermediate face and the front edge of this intermediate face;
• the protuberance came integrally with the arch;
• it is provided on the arch, between the rear drive surface and the protuberance, a clearance extended by a concave connecting surface, having in particular a radius of curvature less than or equal to the distance between dishes of the head, avoiding any contact between the jaw and the front edge of the rear face;
• the front and rear drive surfaces are curved surfaces;
• the radius of curvature of the rear drive surface is less than the radius of curvature of the front drive surface;
• the angle, measured in the direction of drive and defined between the axis of rotation of the polygonal head and the two contact zones between the head and the rear and front drive surfaces, is slightly greater than 180 °;
• the profile of the jaw is formed of a succession of curved portions, connecting tangentially to each other, from the front drive surface to the rear drive surface;
• said jaw is disposed at one end of a key body, provided at its other end with a jaw drive of the same type and of another size or an eye drive head;
• the jaw is of fixed spacing;
• the protuberance is adapted to cooperate with the intermediate face between the half and the third before it, considering the direction of drive, for a head of maximum dimension; and
• the protuberance is adapted to cooperate with the intermediate face substantially four tenths before it, considering the direction of drive, for a head of maximum dimension.

It should be noted that document EP-A 0 580 177 at SNAP-ON TOOLS CORPORATION name describes a clicking key of a significantly different type since it does not no additional support point for the weak applied couples and in the absence of couple.

• le figure 1 est une vue en élévation d'une clé cliquetante selon l'invention ;
• la figure 2 est une vue en élévation de la tête d'entraínement de la clé de la figure 1, représentée dans une position d'entraínement d'un six-pans ; et
• la figure 3 est une vue en élévation de la tête d'entraínement de la même clé, représentée dans une phase de retour autour du six-pans.

The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the drawings in which:

• Figure 1 is an elevational view of a clicking key according to the invention;
• Figure 2 is an elevational view of the drive head of the key of Figure 1, shown in a drive position of a hexagon; and
• Figure 3 is an elevational view of the drive head of the same key, shown in a return phase around the hex.

The clicking key 10 shown in the figure 1 comprises a flattened body 12, of axis X-X, forming an arm actuation. It has one end of a drive head 14 with eye and at its other end a ratcheting drive head 16 with spacing fixed.

Clicking drive head 16, shown in detail in Figures 2 and 3, is formed essentially a jaw 18 open in the extension of the body 12. It is delimited by two opposite jaws 20 and 22 of unequal length. These two jaws are connected by an arch 24, set back and connected to the body 12 by a section 26 of progressively decreasing width towards the body 12.

In Figure 2, there is shown a hex 28 of a screw head, engaged in the head jaw 16. The key is shown here in training position.

The jaw 20, constituting the front jaw considering the direction of training corresponding to the sense of arrow F1, is longer than jaw 22. It has a convex front drive surface 30. This surface front drive is adapted to cooperate with a front face 32 of the drive profile of the hexagon 28. More particularly, the surface 30 is arranged on the jaw 20 to rest on a point 31 of the half before the front face 32, considering the direction of training.

In addition, the contact point 31 of the drive surface 30 with the front face 32 is located at a distance d1 from the front edge 34 of the face 32.

Similarly, the jaw 22, forming the jaw rear considering the direction of training, includes a curved rear drive surface 36. She is adapted to cooperate with the face 38 of the opposite hexagon at the front face 32. The point 37 of contact of the surface drive 36 with the rear face 38 is located in the front half of this rear face considering the sense of training. It is placed at a distance d2 from the front edge 40 of the rear face 38.

Front drive surfaces 30 and rear 36 are formed by protuberances 30A, 36A from material with the front 20 and rear 22 jaws respectively. Furthermore, the radius of curvature of the protuberance 30A carrying the front drive surface 30 east much greater than the radius of curvature of the protuberance 36A carrying the rear drive surface 36. As example, the radius of curvature of the protrusion 30A is approximately half the distance between dishes of the hexagon, while the radius of curvature of the protuberance 36A equals approximately one-eighth of the distance between hexagon dishes.

The two drive surfaces 30 and 36 are arranged so that the distance d1 is less at distance d2. So the angle at the center α (Figure 2), measured in the direction of training, defined by the contact points 31 and 37 is slightly higher at 180 °, and is for example equal to 183 °. Following the manufacturing tolerances for the hexagon head, angle α is between 181 ° and 186 °.

In addition, there is provided on the arch 24 a protuberance domed 42, integral with this hoop. This protuberance 42 is adapted to cooperate with a intermediate face 44 of the hexagonal drive profile 28. This face 44 is arranged opposite the arch. 24 between the front 32 and rear 38 faces. More specifically, this intermediate face 44 is located immediately in front of the rear face 38 considering the direction of drive, and is connected to it by the edge 40.

The protuberance 42 is adapted to cooperate, during the installation of the key and during the application of a couple on the hexagon 28, with a point support 43 of the intermediate face 44 located in the half before it considering the direction of training, this over the whole range of applied couples and in the absence of a couple.

It goes without saying that the fulcrum 43 is in fact formed by a support segment extending along the thickness of the key.

The contact point 43 is located at a distance d3 of the front edge 46 of the intermediate face 44 which is greater than or equal to the distance d2. In addition, it is located in the vicinity of the front third, in particular between the front third and front quarter, from face 44 for a hexagon maximum dimension taking into account the tolerances of manufacturing.

The radius of curvature of the protuberance 42 is approximately equal to a quarter of the distance between plates of the hexagon 28.

A rounded clearance 48 for receiving the edge 40 located at the front of the rear face 38 is provided on the jaw 22, between the rear bearing surface 36 and the protuberance 42. This clearance 48 is provided immediately ahead of the protrusion 36A. This last and clearance 48 have radii of curvature substantially equal and inverted, and they are tangentially connected to one another. Clearance 48 is returned sufficiently deep to avoid contact between the jaw 24 and the edge 40, whatever the torque applied.

A concave connecting surface 49 tangentially connects clearance 48 to protuberance 42. This concave bonding surface has a smaller radius of curvature or equal to the distance between dishes of the hexagon.

As shown in the figures, the inner profile of the jaw 18 is formed from its front end to its rear end of a succession of curved portions, tangentially connecting to each other. In addition, as is shown in Figure 2, the connecting arch is, in outside the fulcrum 43, entirely spaced from the hexagon 28 in the drive position, regardless of applied torque and in the absence of torque.

We understand that when applying a torque, in the direction of arrow F1 (Figure 2), and this whatever its value, there are three points of contact between the key and the hexagon, all located in the front half of the three corresponding sides of the hexagon. This arrangement ensures optimal application and stable tightening torque. The support point 43 guides the key over the entire thickness of it, so that this tends to remain perpendicular to the axis of the screw during tightening.

In addition, the fulcrum 43 serves as a guide and precise stop for the key when engaged lateral on the hexagon.

We still see that if we apply to the key excessive torque, pressing the key on the hexagon point 43 is becoming more and more important, and the exhaust is amortized, which improves the safety of use.

Furthermore, the angular offset, considered from axis O, between contact points 37,43 and 31 distributes the forces clearly behind three edges hexagon. Thus, no edge is requested from preferentially nor directly, so that none of them is not exposed to premature wear.

Furthermore, the distance d2 being greater than the distance d1, the rear drive surface 36, despite its relatively small radius of curvature, cannot damage the edge 40, since the area of application of the force is located at a sufficient distance d2 from this fish bone. Thus, the small radius of curvature of the surface rear 36 relative to the front surface 30 is offset by the fact that the distance d2 is greater than the distance d1.

In Figure 3, there is shown the head 16 of the ratchet wrench in a return position, or reprise. This return is exercised by moving the key in the direction of arrow F2, opposite arrow F1, around hexagon 28. When returning, the drive surface 36 of the rear jaw 22 follows the rear face 38. Thus, the jaw before 20, and in particular its surface drive front 30, emerges from the front face 32 up to exceed the rear edge 50 thereof. In these conditions, the surface 36 bypasses the rear edge 51 of the rear face 38 and comes to bear on the face 52 hexagon located immediately behind the face rear 38.

We can see that the application of the surface 36 on the face 52 again allows the drive hexagon in the direction of arrow F1, as explained above.

Alternative angular displacement movements and successive of the drive head 16 in the direction of arrows F1 and F2 thus allow training hexagon 28 (in the direction of arrow F1) without it be necessary to completely disengage the drive head 16 of the drive profile of the hexagon 28 during recovery phases.

In addition, the relative angular distance of the three points of contact of the drive surfaces 31,37,43 on the hexagon profile ensures good stability of the wrench when applying the torque in a plane orthogonal to the axis of the hexagon and in the absence of couple.

Furthermore, the drive head 14 to eye provided at the other end of the key body 12 can be replaced by a clicking head of the same type than the one placed at the first end but of different dimension.

In the embodiment described with regard to drawings, the contact point 43 is located between the third front and front quarter of face 44 for a hexagon of maximum dimension.

However, in a variant not shown, the contact point 43 is located substantially between the half and the front third of face 44 for a hexagon maximum (or nominal) size. In particular, the point of contact is established on the nut substantially at four tenths before the intermediate face 44 (i.e. d3 close to 0.4 times the nominal length of the face 44).

Claims (13)

1. Ratchet spanner (10) for turning a part, in particular a screw or a nut (28), the head of which comprises a hexagonal turning profile, which spanner (10) comprises an open jaw (18) delimited by a leading grip (20) and a trailing grip (22), with reference to the turning direction, the said grips being connected by an arcuate web (24), each grip (20, 22) comprising a turning surface (30, 36) for co-operating respectively with a leading face (32) and a trailing face (38) of the turning profile in the leading half of these faces with respect to the turning direction, these two faces (32, 38) being opposed, the jaw (18) also having a rounded complementary support projection (42) on the arcuate web (24) for co-operating with a support point (43) of the intermediate face (44) of the turning profile located immediately before said trailing face (38) with respect to the turning direction, when no torque is applied and over the full range of applied torques, the arcuate web (24), in the turning position, being entirely spaced from said head (28) except at said support point (43) when no torque is applied and when turning torque is applied, characterised in that said support point (43) of said intermediate face (44) is situated in the leading half of this intermediate face when no torque is applied and over the full range of applied torques.
2. Ratchet spanner (10) according to claim 1, characterised in that said projection (42) is suitable for co-operating with said intermediate face (44) near the leading third thereof, with respect to the turning direction, for a head (28) of maximum size.
3. Ratchet spanner (10) according to claim 1 or 2, characterised in that the distance (d2) between the contact zone (37) of the trailing turning surface (36) with the trailing face (38) and the leading edge (40) of this trailing face is less than the distance (d3) between the point (43) of contact of the projection (42) with the intermediate face (44) and the leading edge (46) of this intermediate face.
4. Ratchet spanner (10) according to any one of the preceding claims, characterised in that the projection (42) is integral with the arcuate web (24).
5. Ratchet spanner (10) according to any one of claims 1 to 4, characterised in that, provided on the arcuate web (24) between the trailing turning surface (36) and the projection (42) is a clearance (48) extended by a concave linking surface (49), having, in particular, a radius of curvature which is smaller than or equal to the distance between faces of the head (28), avoiding all contact between the jaw (18) and leading edge (40) of the trailing face (38).
6. Ratchet spanner (10) according to any one of the previous claims, characterised in that the leading (30) and trailing (36) turning surfaces are rounded surfaces.
7. Ratchet spanner (10) according to claim 6, characterised in that the radius of curvature of the trailing turning surface (36) is smaller than the radius of curvature of the leading turning surface (30).
8. Ratchet spanner (10) according to any one of the preceding claims, characterised in that the angle (α) measured in the turning direction and defined between the axis of rotation (O) of the polygonal head (28) and the two contact zones between the head and the trailing (36) and leading (30) turning surfaces, is slightly greater than 180°.
9. Ratchet spanner (10) according to any one of the preceding claims, characterised in that the profile of the jaw (18) is formed by a succession of curved portions, being tangentially connected to one another, from the leading turning surface (30) to the trailing turning surface (36).
10. Ratchet spanner (10) according to any one of the preceding claims, characterised in that said jaw (18) is arranged at one end of a spanner body (12), provided at its other end with a ratchet turning jaw of the same type and a different size or a turning head (14) with an eye.
11. Ratchet spanner (10) according to any of the preceding claims characterised in that the jaw (18) has fixed spacing.
12. Ratchet spanner according to any of the preceding claims characterised in that the projection (42) is intended to cooperate with the intermediate face (44) between the half and the leading third thereof with respect to the turning direction, for a head of maximum size.
13. Ratchet spanner according to any of the preceding claims characterised in that the projection (42) is adapted to cooperate substantially with the leading 4/10ths of intermediate face (44) with respect to the turning direction, for a head of maximum size.

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