WO2000029152A1

WO2000029152A1 - Device for piercing lockwire holes

Info

Publication number: WO2000029152A1
Application number: PCT/FR1999/002778
Authority: WO
Inventors: Noureddine Chahed
Original assignee: Noureddine Chahed
Priority date: 1998-11-13
Filing date: 1999-11-12
Publication date: 2000-05-25
Also published as: FR2785837A1; FR2785837B1

Abstract

The invention concerns a device for piercing lockwire holes on nuts (1) and screw heads hexagonal in shape, comprising a bush-bearing part (3) having at least a slope (20) at 60° relative to the horizontal against which is urged to press a surface (a) of the nut (1) to be pierced, a drill bushing (2) including on its shank a slope at 60° mounted in the vertical axis of symmetry (Z) of the slope (20) of the bush-bearing part (3) and serving as guide to a sensitive perforating machine drill (6), a lower support (4) receiving a surface (c) of the nut (1), and, co-operating with said elements (2, 3, 4) a flange (5) comprising a notch at 120° matching the surfaces (d, e) of the nut to be pierced. The position of the lockwire hole relative to the nut vertical axis of symmetry is adjusted by varying the height of the lower support (4).

Description

"Brake wire hole drilling device"

The invention is in the field of mechanical devices for producing nuts of a particular type. It relates more particularly to a device and an associated method for drilling holes called brake wire holes on nuts and screw heads of hexagon shape. In the remainder of this text, reference is made to hexagonal bolts or nuts. It is clear that the device and the method apply with minor modifications to any nut comprising any number of facets, or even a known external shape (for example cylindrical). The nuts in question in the present invention are used particularly in the aeronautical, space, military fields, when a nut or a screw head must be securely locked in a predetermined position, with the certainty that it does not loosen not unintentionally. One of the solutions then consists in using a nut which has a hole connecting two facets, a metal wire being inserted in this hole and attached to a fixed element located nearby.

In the past, "brake wire hole" nuts were most often made manually, and therefore at a very high manufacturing cost per unit.

The problem posed in the present invention is that of the drilling method for making a brake wire hole when attacking with a forest an inclined plane on a nut. Because of this plane inclined at 60 °, the forest tends to slide in the direction of the inclined plane.

Various previous patents relate to devices for drilling wire brake holes. The first patent n ° UK 882.805 (Valeport company) dates from February 24, 1959 and is in the public domain.

Likewise, the second French patent n ° 1.465.819 of January 5, 1966 is also in the public domain.

In the English patent of the Valeport company, the inventive idea is to use rafters which compensate for the slope of entry to allow a perpendicular attack of the forest. This device makes it possible to reduce the breakage of the tool at the inlet or outlet of the hole. However, on the one hand, the steels forming the nuts in the sixties were less hard than current steels, thus allowing easier drilling. On the other hand, the device assumes the loss of a chevron with each use. Furthermore, this device does not allow any precise adjustment of the position of the brake wire hole along the facet. It therefore involves successive trial and error work until a correct rating is obtained.

Finally, the creation of a chip coming out of the hole when the rafter is pierced leads to an oval shape of the rafter, which tends to drive out the forest and therefore to create a drilling error. In a variant, the same chevron is used for several successive holes. In this case, there is gradually created a drilling game increasing each time.

In summary, the invention described in the Valeport patent requires a number of rafters close to the number of holes, and a template per hole diameter. Finally, we note that delivery times for rafters are a problem in continuous manufacturing, and that the cost of dedicated machines is very high.

In addition, the current trend is to see the tolerance on wire-brake holes becoming more and more strict. It is therefore necessary to obtain side and precise position holes on the nuts.

Laser drilling techniques have been successfully tried for diameters less than 1 mm. Above this value, drilling by laser technique is not possible due to the volume of molten metal involved. Among the other techniques having a similar purpose to that of the brake profile, that is to say the locking of a nut in a predetermined position, braking in the axis or the fitting of a pad which is folded over a nut bridge.

Also known is a device described in US Patent 5,409,327 of April 25, 1995, in which wire brake holes are made on a hexagonal nut, using three identical parts each comprising a notch at 120 ° and which tighten the nut . Each of these parts has a drilling guide made of reinforced material and a horizontal facet (compensating the bevel at 60 °) to allow drilling, and support of the drill.

This device is both expensive and complex. It does not easily accommodate different sizes of nut and even less to modify the point of impact of drilling on one face of said nut. Replacing a template with another template is a complex operation. The machine dedicated to this use is specific and cannot be easily obtained by modification of an existing machine.

Finally, there is known a Soviet patent No. 1,731,459 filed January 23, 1990 and which again uses a flange having a notch at 120 ° in which drilling guides have been previously arranged.

This device does not allow the position of the drilling holes to be adjusted on the face of the nut, but simply compensates for the 60 degree slope of the face of said nut. Similarly, the forces created by the drilling on the bolt are taken up mechanically by the notch flange device, which gradually introduces mechanical play between the different parts. This phenomenon is naturally harmful to a reproducible precision of drilling. It therefore seems hardly compatible with the current requirements in terms of precision to position the brake wire holes. The present invention therefore aims to remedy the aforementioned drawbacks and in particular to eliminate most of the consumables.

According to another objective of the invention, it avoids having to perform a link between different settings, and therefore allows a very significant time saving.

According to a third objective of the invention, it makes it possible to precisely choose a point for drilling a brake wire hole at any point on one face of a nut.

The invention provides for this purpose a device for drilling brake wire holes on nuts and screw heads of hexagonal shape, comprising a barrel holder part having at least a slope at 60 ° relative to the horizontal against which comes press one side of a nut to be drilled, a drilling barrel having a 60 ° slope on its barrel being mounted in the vertical axis of symmetry of the slope of the gun holder part and serving as a guide for a forest of a sensitive drill, a lower support receiving one face of the nut, and, in cooperation with these elements, a flange comprising a notch at 120 ° which matches the faces of the nut to be drilled, characterized in that the adjustment of the position of the brake wire hole relative to the vertical axis of symmetry of the nut is obtained by varying the height of the support inferior.

The technical teaching of the invention resides in the joint use of 3 parts for drilling a brake wire hole. The nut is first locked against a flange with a 120 ° notch. A second piece forming a lower support is placed against a lower face of the nut. Finally, a piece known as a bore gun holder, bevelled at 60 degrees comes to bear on the face of the nut in which the brake wire hole must be drilled. This gun holder piece supports a very hard metal barrel (hardened steel) which serves as direction and position adjustment for the drill.

The respective adjustment of these three elements relative to each other allows, on the one hand, to accommodate bolts of different sizes, on the other hand, to determine the exact position of the brake wire hole on the side to be drilled from the 'nut, finally to carry out the clamping of the nut before its drilling In addition the gun holder part can be arranged on a turret allowing to have very easily a large number of drilling jigs, of different diameters. Adjusting the right diameter to the correct position of the nut is very quick.

This device effectively eliminates disposable chevrons and therefore allows significant savings in resources. The speed of work is also a very important advantage.

In summary, the device according to the invention uses a blocking of the nut between three elements bearing on opposite faces of said nut. It also includes means for adjusting the height or width of two of these locking elements relative to the third, finally one of these elements includes a drilling guide of predetermined diameter.

According to a preferred arrangement, this element forming a drilling guide is removable. Preferably, it is part of a drilling turret comprising at least one of which the drilling guide corresponding to different drilling diameters.

Preferably, the turret is also adjustable in height so as to accommodate different sizes of nut.

It is understood that compared to the patent describing the Valeport invention, the present invention uses a device in which the functions of locking the nut and compensating for the slope at 60 ° are separated.

In the above-mentioned device, the nut was tightened between a flange having a 120 degree hook on one side and a chevron on an opposite edge also comprising a 120 degree notch, the two end faces of which allowed the nut to be pierced.

In this device the vertical force imposed by the drill on the bolt was taken up by the rafter and the opposite flange. This resulted in an inevitable play of elements and therefore an error on the piercing.

The device according to the invention completely avoids this problem, the drilling barrel having the sole function of being positioned correctly at the place where the drilling is to be carried out.

The description and the drawings of a preferred embodiment of the invention, given below, will make it possible to better understand the aims and advantages of the invention. It is clear that this description is given by way of example, and is not limiting. In the drawings:

- Figure 1 schematically shows the three elements of the device according to the invention; - Figure 2 shows a 60 ° bevelled drilling gun;

- Figure 3 shows a gun holder part equipped with drilling guns;

- Figure 4 shows a drilling template in one piece;

- Figure 5 shows schematically a device according to invention in side view;

- Figure 6 shows in perspective a device according to the invention;

- Figure 7 shows a rotary turret carrying a series of drilling barrels mounted on a turret support with adjustable height; - Figure 8 illustrates a similar perspective view of a rotary turret alone;

- Figure 9 shows a perspective view of an adjustable notch clamping device. As can be seen in FIG. 5, the device for drilling brake wire holes according to the invention comprises a substantially rectangular elongated base 7 (longitudinal axis X), equipped with two longitudinal slides 8.

The base 7 is for example of dimensions close to 20 centimeters in length, for 6 centimeters in width and 4 centimeters in height.

The base 7 comprises at one of its ends a fixed block 11 which supports a barrel-holder part 3 comprising at least one drilling barrel 2.

This fixed block also includes a lower support 4, in the form of a protrusion extending from the fixed block 11 along the longitudinal axis X. This lower support 4 is adjustable in height along the internal face of the fixed block 11, by action of a vernier 12.

On the opposite side of the base 7, and facing the drilling barrel 2, a mobile carriage 13 capable of moving along the longitudinal slides 8, is slaved to a lead screw 9 (not visible in FIG. 5) secured to a control wheel 10. The movement of the mobile carriage 13 along the longitudinal rails 8 makes it possible to determine a more or less large space between said mobile carriage 13 and the fixed block 11, which allows the positioning of a nut 1 of size extremely variable in this space, in view of its drilling. Typically, nut dimensions 1 ranging from 6 to 80 mm on a flat dimension can be envisaged with this device.

The mobile carriage 13 supports a flange 5, provided with a notch, the two planes of which form an angle of 120 °, and the axis of which is parallel to the horizontal (transverse axis Y). This flange 5 is adjustable in height along the movable carriage 13, by the action of a knurled button 14.

An adjustable stop 15, movable along the transverse axis Y is disposed substantially on one side of the base 7. It is mounted at the rear of the part barrel holder 3, on a tongue 16 provided with an oblong hole.

It allows transverse adjustment of the position of the nut 1 on the device, so as to select the drilling point on one face of the nut

1. The drilling barrel 2 (as illustrated in FIG. 2) has on its barrel a slope of 60 ° relative to the horizontal, so as to come to correspond to the slope of a facet of the nut 1.

The barrel-carrier part 3 (FIG. 3) is a part comprising at least one slope produced at an angle of 60 ° relative to the horizontal. In the vertical axis (Z) of each slope is a calibrated bore 17 in which is mounted a drilling barrel 2, fixed or removable, with or without collar 18.

The two parts (barrel holder part 3 and drilling barrel 2) are assembled in such a way that the two slopes are flush so as to form only one and the same application surface 20 at 60 ° with respect to the horizontal. In a variant, the barrel-holder part 3 can be a template (FIG.

4) drilling, comprising at least one slope 20 inclined at 60 ° provided with a drilling hole 21 (parallel to the vertical axis Z) opening and opening on its upper surface 19. This drilling template having been quenched giving sufficient hardness then works like a drilling gun 2.

The flange 5 having a notch at 120 ° is mounted on the movable carriage 13, thus allowing it to carry out a translational movement along the axis X in order to be able to block or release at will the nut 1 to be drilled. This translational movement can be controlled manually or by means of an electric motor or a jack, this flange 5 can also be adjusted in height relative to the drilling barrel 2, in order to adapt to the different dimensions on the flat nuts.

The lower support 4 is provided with an adjustment means (by action of the vernier 12), to allow the positioning of the brake wire hole relative to the vertical axis of the nut 1. In fact, it is understood that the more the support lower 4 approaches the drilling barrel 2, the more the axis of the brake wire hole moves away from the vertical axis of symmetry of the nut 1 to be drilled, and vice versa.

The adjustment of the position of the brake wire hole relative to the axis of vertical symmetry of the nut 1 can also be done by varying the height of the barrel holder part 3 relative to the lower support 4.

Given the importance of this adjustment, the lower support 4 is coupled to a graduated vernier 12. To obtain a fine adjustment of the lower support 4, the latter is mounted on a vertical threaded axis, driven by a couple of bevel gears. the motor element of which is itself coupled to the vernier 12.

The position of the brake wire hole in the thickness direction of the nut 1 is adjusted by means of the adjustable stop 15, for example produced in the form of a threaded rod, or of a micrometric stop, or any other device. The device as described can be equipped with a fixed drilling head, the working axis of which is aligned with the axis of the drilling barrel 2.

The drilling head can also be moved manually or automatically to be able to drill two opposite brake wire holes, on the same nut 1. This device can also be equipped with two drilling heads to drill two opposite brake wire holes, on the same nut 1 .

The various parts forming the device according to the invention are produced according to a conventional embodiment, known per se and generally made of steel or an alloy of the AU4G type in the present example. The device is intended to be used in conjunction with a sensitive metal drill of conventional type (not shown), the drill 6 of which is movable along the vertical axis Z (working axis) and is coincident with the axis of the barrel of drilling 2.

With reference to FIG. 1 which illustrates the operating mode of the device, the nut 1 which is in the drilling position is firmly held by the following three elements of the device:

- 1 / the drilling barrel 2 and barrel holder 3 assembly comprising a slope 20 to 60 ° relative to the horizontal which matches a face (a) of the nut 1 - 2 / the lower support 4 supporting a face (c) of nut 1

- 3 / finally the flange 5 which has a notch forming an angle of 120 ° which envelops the faces (d, e) of the nut 1.

From the moment when the drill 6 (figure 1) of the drill is engaged in the drilling barrel 2, it is firmly guided and maintained in its working position, without it being able to hunt.

In an advantageous variant (as illustrated in FIGS. 3, 4, 6, 7 and 8), the barrel-holder part 3 is a rotary turret 22, movable in rotation about a vertical axis Z, comprising a plurality of barrel drilling 2 with an axis parallel to the vertical axis Z and disposed at equal distance from the axis of rotation of said rotary turret 22. It here comprises ten drilling guns 3 (FIG. 7), angularly spaced at regular intervals.

In one embodiment by way of example, the barrel-holder part 3 is made of CD4 steel with a treatment of type 63 HKC, with rectified facets.

Different diameters are chosen for each drilling barrel

2, so as to provide the user with the most frequent diameters, each piercing barrel being able to be placed in front of a given nut by simple rotation of the barrel-carrier part around a vertical axis of revolution Z.

In this same variant, the rotary turret 22 is secured to a turret holder part 23, adapted to be fixed to the fixed block 11 of the base 7.

The turret holder part 23 then has a long notch 24, which allows a height adjustment of the turret 22 above the base 7 and therefore therefore an adjustment of the vertical distance of the drilling barrel 2 to the lower support.

4.

The rotary turret then comprises, for each drilling barrel 2, an angular position mark, in the form of a housing 29 for a turret locking ball (not shown), arranged on the upper face of the turret holder part. 22 and secured to a locking means comprising a return spring. In this way, the turret 22 is naturally positioned in a position such that one of its drilling barrels is correctly placed in front of the nut 1.

In this same variant, the flange 5 is provided with a lateral displacement means 25 along the axis Y (see FIGS. 6 and 9).

The notch at 120 ° is then preferably produced by juxtaposition of dihedrons 26, 27, tightened together in a position adapted to the range of nut to be drilled, using clamping screws 28. It is clear that with the device as described here, the device is never unbridled from the drilling plate, since the drill here is always correctly aligned with the drilling gun 2 chosen, the drilling axis never being modified on the device as described, regardless of the diameter of the nut 1 to be drilled. This makes it possible to have only one precise alignment to be made of the drill and of the device, unlike the devices of the prior art, which required an unclamping and a rebridling of the machine with respect to the drilling marble at each change of drilling or nut size barrel. It is clear that, as a variant, it is possible to produce a machine comprising both the device as described and an integrated drill, either of the conventional mechanical type, or of the electroerosion or laser type (for small drilling diameters).

It will be understood in summary that the device according to the invention allows adjustment of the drilling point of a brake wire hole at any point on a facet of a nut, unlike previously existing devices.

The scope of the present invention is not limited to the details of the above embodiments considered by way of example, but on the contrary extends to modifications within the reach of ordinary skill in the art. In particular, the replacement of manual settings by pneumatic devices does not modify the principle of operation of the device.

Claims

1. Device for drilling brake wire holes on nuts (1) and hexagonal screw heads, comprising a barrel-holder part (3) having at least one slope (20) at 60 ° with respect to the horizontal against which is pressed against one side (a) of a nut (1) to be drilled, a drilling barrel (2) having on its barrel a slope at 60 ° being mounted in the vertical axis of symmetry (Z) of the slope (20) of the barrel holder part (3) and serving as a guide to a forest (6) of a sensitive drill, a lower support (4) receiving one face (c) of the nut (1), and, in cooperation with these elements (2, 3, 4), a flange (5) comprising a notch at 120 ° which matches the faces (d, e) of the nut (1) to be drilled, characterized in that the adjustment of the position of the brake wire hole relative to the vertical axis of symmetry of the nut is obtained by varying the height of the lower support (4).

2. Device according to claim 1, characterized in that the drilling barrel (2) is fixed.

3. Device according to claim 1, characterized in that the drilling barrel (2) is removable.

4. Device according to any one of claims 1 to 3, characterized in that the drilling barrel (2) and barrel holder part (3) is integrated in a drilling template comprising at least one slope (20) to 60 ° relative to the horizontal, comprising along its vertical axis of symmetry (Z) a drilling hole (21).

5. Device according to claim 4, characterized in that the drilling template is made of hardened high-strength steel.

6. Device according to any one of claims 1 to 5, characterized in that the flange (5) is provided with an adjustment means along the vertical axis (Z).

7. Device according to any one of claims 1 to 6, characterized in that the flange (5) is provided with a lateral displacement means.

8. Device according to any one of claims 1 to 7, characterized in that it comprises two drilling heads (3), adapted to allow the drilling of brake wire holes on two sides of a nut (1).

9. Device according to any one of claims 1 to 8, characterized in that it comprises a rotary turret (22), mobile in rotation about a vertical axis (Z), comprising a plurality of drilling barrel (2 ) of axis parallel to the vertical axis (Z) and arranged at equal distance from the axis of rotation of said rotary turret (22).