Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING, OR HOLDING
  • B25B15/00—Screwdrivers
  • B25B15/001—Screwdrivers characterised by material or shape of the tool bit
  • B25B15/004—Screwdrivers characterised by material or shape of the tool bit characterised by cross-section
  • B25B15/008—Allen-type keys
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING, OR HOLDING
  • B25B13/00—Spanners; Wrenches
  • B25B13/02—Spanners; Wrenches with rigid jaws
  • B25B13/06—Spanners; Wrenches with rigid jaws of socket type
  • B25B13/065—Spanners; Wrenches with rigid jaws of socket type characterised by the cross-section of the socket

Definitions

• the present invention relates to a tool for tightening / loosening an associated driven threaded member comprising a regular polygonal driven profile, tool of the type comprising a head whose active profile has a roughly polygonal shape, with a regular polygon inscribed or circumscribed whose the side has a length 2L, at least one side of the active profile consisting of two asymmetrical half-sides from one another with respect to the median axial plane of this side.
• the invention applies in particular to female tools intended to drive a nut or a male bolt head, such as sockets, pipe wrenches, eye wrenches and pipe wrenches, but also to male tools intended for drive a screw whose head has a polygonal recess.
• FR-A-2 703 619 proposes tools of the aforementioned type which make it possible to apply to the driven member a higher torque in a first direction than in the other direction before destruction of the tool head.
• a rounding that is to say a small contact radius
• the downside is that the localized attack of each plate of the nut is made near each edge of the nut and near each corner of the profile.
• the object of the invention is to obtain an increase in power on loosening with better protection of the threaded member and of the tool.
• the subject of the invention is a tool of the aforementioned type, characterized in that the half-side corresponding to a first direction of drive comprises a rounded or an attack edge whose point closest to the associated side of the regular polygon inscribed or circumscribed, is located at a distance from the perpendicular bisector on this side of between L / 4 and 2L / 3, said half-side being entirely cleared with respect to said polygon of said point at the corresponding corner of the polygon, the half side corresponding to the other drive direction comprising a rounded or an attack edge whose point closest to said associated side is located at a second distance from said perpendicular bisector greater than said first distance.
• the tool / nut contact is further from the edge of the nut and the stresses are better diffused in the head of the tool, in said first direction than in the other direction.
• FIG. 1A shows, in cross section and in top view, part of a six-sided female tool according to the invention, during tightening of a male threaded member;
• FIG. 1B is a similar view during loosening of the threaded member;
• Figure 2 is a similar view of a variant
• Figure 3 is a similar view of another variant
• Figure 4 is a similar view of a twelve-sided female tool according to the invention, during the loosening of a male threaded member with hexagon;
• FIG. 5 is a similar view of the tool of Figure 4, in the process of loosening a threaded member with twelve sides;
• FIG. 6 is a similar view of a six-sided male tool according to the invention.
• O denotes the center of the section of the head of the tool, which has a roughly hexagonal active profile of which only around one third of the periphery has been shown.
• a side 1 of the profile will be described, extending between two virtual corners and seen from point 0 at an angle of 60 ° delimited by two rays 2 and 3.
• the head 4 of the tool comprises an active female profile 6 has six sides and is delimited externally by a circle 5 of center 0.
• the profile 6 is circumscribed to a hexagon H of the same center and side 2L, shown in thin lines in Figure 1, the corners 7 of which are on the spokes such as 2 and 3.
• the real male hexagonal threaded members 8, for example a nut or a bolt head, as shown in solid lines, are smaller than hexagon H and can be styled with a certain play, depending on manufacturing tolerances of these members 8 and of the tool, through the head 4.
• side 1 is made up, from left to right in the drawing, of two half-sides, namely a half-side ID which corresponds to the direction of loosening (action on the tool exerted in the direction F D ), and a half-side IS which corresponds to the direction of tightening (action of the tool exerted in the direction F s ).
• the ID half-side consists successively, from left to right:
• the segment 12 could be replaced by a curve situated outside the hexagon H and tangentially connected to the rounding 11.
• the radius R is slightly greater than the length of the radius 2, so that the arc 9 does not interfere with the corner 7.
• the difference in the two lengths is minimal and, ultimately, can be zero, as illustrated in Figures 4 and 5.
• the IS half-side consists successively, from left to right: - a line segment 14 merged with the side of the hexagon inscribed H, and consequently extending the segment 12;
• the segment 14 is tangentially connected to the circular arc 15, which is connected tangentially to the rounding 16.
• the latter likewise, is tangentially connected to the circular arc 9 of the following half-side ID, by turning in clockwise.
• the half-side IS is, in this example, as described in EP-A-0 156 681 in the name of the Applicant. Variants similar to that described above for the ID half-side are possible. Of course, in all cases, side 1 must have at least two points located on hexagon H.
• the radii ri, r2 and r3 are close to each other. For reasons of manufacturing convenience, they are preferably chosen to be equal, with a value substantially equal to 0.25L. As shown in Figure 1A, when the head 4 is driven in the direction F s clamping, due to the play between the two parts, the plate member 8 is driven by the arc 15 after the head A has turned by a small angle ⁇ relative to the member 8 before coming into contact o
• the distance to the perpendicular bisector 13 from the point of contact of the arc 15 with the member 8 is slightly greater than y.
• the point of contact of the active profile 6 with the member 8 is at a distance from the perpendicular bisector 13 slightly greater than x. It is understood that beyond the point of contact by going towards the corner 17 of the member 8, the profile 6 is entirely released from this member.
• each dish of the member 8 is attacked on loosening closer to its median plane P ', the trace of which is the perpendicular bisector 23, with respect to the tightening.
• the distance x remains sufficient to maintain a large lever arm during the application of the loosening torque, and not to excessively increase the rotation ⁇ of the head 4 relative to the member 8 for play. given, i.e. for a given difference between the distances between dishes of hexagon H and organ 8.
• attack radius 11 of small radius also produces, on loosening, an inclination effect of the force vector which increases the lever arm, which contributes to the increase in stresses induced in the member 8 and therefore to the increase in the loosening torque applied to the threaded member.
• the two rays, starting from the center 0, which surround the arc of a circle 9 define in the head 4, between this arc 9 and the outer circle 5, a region 18 of constant radial thickness e, hatched in the Figure 1.
• This region 18 is a region with particularly high elastic deformability. Tests have shown that the head 4 makes it possible to very significantly increase, by around 10%, the loosening torque which can be exerted before destruction of the tool head, compared to a conventional head of the same radius. outside and circumscribed to a hexagon H of the same distance on flat surfaces a, in accordance with the abovementioned EP-A-0 156 681.
• a x substantially equal to 0.35 L.
• the radius R2 of the arc 109 is clearly greater than ri and is for example 0.5L.
• Figure 4 illustrates the application of the invention to a head 104 having an active profile 106 with twelve sides.
• each side 101 of the active profile 106 is brought to an angle at the center of 30 °, between the lines 2 and 13.
• the arc of a circle 15 on the next side 101, clockwise or anti-clockwise, is tangent to the hexagon H at the left end of the arc 15.
• Figure 4 also shows the use of the head 104 with a male threaded member 8 with hexagon.
• one side 101 on two attacks the flats of the member 8 by its rounded 11.
• the six other sides 101 attack the member 8 by their arcs of a circle 15.
• Figure 5 shows the use of the same head 104 with a threaded member 108 with twelve sides (or twice six sides). In the direction of loosening, each side 101 attacks a flat of the member 108 by its rounded 11. In the direction of tightening, each side 101 attacks another flat of the member 108 by its arc of a circle 15.
• the behavior of the head 104 is substantially the same as in the case of FIG. 4.
• the maximum torque applicable to a threaded member is significantly higher in the direction of loosening.
• Figure 6 illustrates the application of the invention to a tool having a male active head 204 with six sides 201, intended to drive a female threaded member 208, for example a screw head, in hexagon socket.
• the half-side 201S which is now on the left, can be any known profile, for example a simple line segment as shown.
• the half-side 201D is formed successively, starting from the perpendicular bisector 213 on the side 201:
• segment 212 can be replaced by a curve located inside the hexagon H and connecting tangentially to the rounding
• the whole of the side 201 must include at least two points on the hexagon H.
• the distance x is, as before, the distance from point B to the perpendicular bisector 213. It is for example equal to 0.51L.
• Point B is defined as the connection point of 212 and 211, that is, in general, the point of rounding 211 closest to the circumscribed hexagon H.
• the stresses exerted in the head of the tool are better diffused in the first direction than in the other, while the contact stresses on the the driven member are greater in said first direction than in the other, which makes it possible to apply to the driven member a higher torque in said first direction than in the other direction before destruction of the tool head.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9551607

Family Applications (1)

Country Status (4)

Families Citing this family (10)

Family Cites Families (7)

• 1999
  • 1999-11-02 FR FR9913676A patent/FR2800311B1/fr not_active Expired - Fee Related
• 2000
  • 2000-11-02 EP EP00974637A patent/EP1226005A1/de not_active Withdrawn
  • 2000-11-02 WO PCT/FR2000/003058 patent/WO2001032365A1/fr not_active Ceased
  • 2000-11-02 AU AU12864/01A patent/AU1286401A/en not_active Abandoned

Non-Patent Citations (1)

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