KEY DEVICE FOR HOLDING A NUT RETAINER

Abstract

The invention concerns a key device intended to hold a nut retainer in the radial position, when tightening the nut on an associated screw connection, characterised in that it comprises a handle (54) and a head (52) comprising a housing (56) into which a tab of the nut retainer is inserted, said tab being intended to be folded 90° on a body carrying the screw connection, after tightening of the nut, one face (58) of the head having geometry that matches a portion of the body carrying the screw connection that receives the nut, such that the tab of the nut retainer, inserted into the head of the key, is held exactly perpendicular to the outer surface of said portion of the body when the nut is tightened.

Claims

1. A key device intended to hold a nut retainer (10) in the radial position during tightening of the nut (30) on an associated screwed connection (22), characterized in that it comprises a handle (52) as well as a head (54) including a recess (56) in which is inserted a tab (16) of the nut retainer (10), which tab (16) is intended to be folded 90° on a body (20) bearing the screwed connection (22), after tightening of the nut (30), a face (58) of the head (54) having complementary geometry to a portion (21) of the body (20) bearing the threaded connection (22) which receives the nut (30), so that the tab (16) of the nut retainer (10), inserted into the head (54) of the key (50) is held perfectly perpendicular to the outer surface of said portion (21) of the body (20) during tightening of the nut (30).

2. The device according to claim 1, characterized by the fact that the head (54) comprises a cavity (56) corresponding to the recess, covered with an attachment plate (59).

3. The device according to claim 1, characterized by the fact that the recess (56) is made by milling a cavity into the mass of the head (54).

4. The device according to claim 1, characterized by the fact that the recess (56) has depth and dimensions suitable for the tab (16) of a nut retainer (10).

5. The device according to claim 1, characterized by the fact that the face (58) of the head (54), with a geometry complementary to a portion of the body (20), is a cylinder of revolution.

6. The device according to claim 1, characterized by the fact that the face (58) of the head (54) with a geometry complementary to a portion of the body (20) is planar.

7. A set of keys conforming to claim 1, characterized by the fact that each key (50) comprises a recess (56) of geometry and dimensions suitable for a tab (16) of a respective nut retainer.

Description

[0032] Nut retainers 10 suitable for use within the scope of the present invention are known per se, conforming for example to the illustrations given in FIGS. 1 to 4, and will therefore not be described in detail hereafter.

[0033] As a person skilled in the art knows, such nut retainers are available in different materials and in different dimensions depending on the intended applications.

[0034] As was indicated previously, as illustrated in the appended FIGS. 10, 11 and 12, the invention relates to a key device 50 which comprises a handle 52 which carries a head 54, at one of its ends. The head 54 includes a recess 56. This recess 56 has geometry and dimensions suited for receiving the tab 16 of a nut retainer 10. The face 58 of the head 54 opposite to the handle 52 has a geometry complementary to a portion 21 of the body 20 bearing the threaded connection 22. According to the representation given in appended FIGS. 10 and 12, the aforementioned face 58 is a cylinder of revolution around an axis perpendicular to the main faces of the handle 52. The aforementioned axis is thus preferably parallel to the axis of the threaded connection 22. In other words, the generators which form the face 58 extend parallel to the axis of the threaded connection and thus this face 58 is intended to rest against a face 21 of the body 20 which, for its part, is defined by generators which extend parallel to the axis of the threaded connection. This face 58 is concave cylindrical according to FIGS. 10 and 12.

[0035] The recess 56 which leads to the face 58 can be produced by many appropriate means, for example by milling a cavity into the mass of the head 54. According to an advantageous embodiment illustrated in the appended FIGS. 10 to 12, the recess 56 can be simply made by machining a cavity of appropriate dimensions and geometry complementary to the tab 16 on a main face of the head 54, then covering this cavity 56 with an attachment plate 59.

[0036] The key 50 is preferably made of metal.

[0037] The essentials of its use will now be described with regard to the appended FIGS. 16 to 19.

[0038] First, as illustrated in FIG. 16, a nut retainer is installed on a threaded connection 22 and the tab 16 is oriented generally perpendicular to the outer face 21 of the body 20, then the free end of the tab 16 is engaged in the recess 56.

[0039] The key 50 is pressed in as illustrated in FIG. 17 to bring its bearing face 58 into contact against the blank 21 of the body 20 bearing the threaded connection on which is engaged the associated nut retainer 10.

[0040] It is then sufficient to hold the key 50 in contact with the outer surface 21 of the body 20 while carrying out the operation of tightening the nut as shown schematically in FIG. 18 to guarantee correct positioning of the tab 16 with respect to the blank 21 of the body 20, as illustrated in FIG. 19.

[0041] The present invention thus makes it possible to guarantee holding of the nut 30 at the desired nominal tightening torque once the tab 16 is folded squarely at 90 degrees to the plane of the washer, parallel to the axis of the nut, along the blank 21.

[0042] A person skilled in the art will understand that the key conforming to the invention allows a secure and quick motion without complications in implementation and without consequent additional cost.

[0043] As illustrated in FIGS. 13, 14 and 15, a set of keys 50 is proposed within the scope of the invention, the recesses 56 whereof are respectively suited to the geometry and to the dimensions of the tabs 16 of the nut retainers in question.