FR2840551A1 - Temporary fastening procedure for sheet metal components uses machine screw rotated in holes in components to draw them together - Google Patents

Abstract

The procedure uses a machine screw (300) that goes through holes in two sheet metal components (100, 200). Once the head (310) of the screw is pressing against the first component its continued rotation pulls the second component against the first. In variants of the design the holes (110, 120) in the two components can be of different diameters, with the hole in the first component being larger and the hole in the second threaded to receive the screw and the screw can be made self-piercing or self-tapping.

Description

that the metal bath is a copper bath.

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  PINING METHOD AND FASTENING MEANS FOR

PUT IN W RE

  FIELD OF APPLICATION OF THE INVENTION

  The present invention relates to the field of docking of two elements such as sole and in particular to adaptations for carrying out their pinning and

  their permanent fixation in the best conditions.

DESCRIPTION OF THE PRIOR ART

  Pinning is an operation ensuring the temporary fixing of two elements such as t81es between them, which is carried out before the permanent fixing operation, conventionally assumed in the aeronautical field at

means of rivets.

  The applicants noted that the pinning operation, as conventionally carried out, presented

disadvantages.

  Thus, for example, such an operation requires, before the positioning of the pinning element, the per, cage of the two heads. This prior drilling is a generator of chips not only outside the blades but also between the blades, which can make the future permanent fixing operation difficult or improper. There is in the prior art a pinning process in which the tightening operation is carried out by means of rivets which wind blind to avoid the obligation of access from both sides. These blind rivets have the major drawback in the context of a pinning application, of offering only a small amount of tension installed in the tightening they achieve, which can turn out to be particularly disadvantageous for the operation of permanent fixing which conventionally follows. ltoperation of temporary fixation. In addition, these blind rivets are then most often removed by perc

  axial, which also generates chips.

  In another known pinning method, the operation

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  Tightening is carried out by means of an elastic fixing element comprising a spring capable, once the fastening element is installed, of maintaining a tightening tension to properly prepare for the permanent fixing operation which follows. This fastening element has a particularly expensive cost for a very short lifespan and therefore cannot be a particularly effective solution for carrying out the pinning operation. Other methods exist but require access from both sides of the partition defined by the joined panels which considerably increases the duration of an operation which is, a priori, only temporary. Indeed, although less numerous than the fixing means necessary for the permanent fixing operation, the pinning operation or non-permanent fixing of one head relative to the other necessitates the presence of a

multiple means of pinning.

DESCRIPTION OF THE INVENTION

  On the basis of this fact, the applicants carried out research on a new pinning process in order to avoid the additional costs of the pinning processes of the prior art as well as the presence of shavings liable to make the following fixing operation difficult.

permed.

  This research has resulted in the design of a particularly simple and advantageous pinning method which makes it possible to overcome the drawbacks of the prior art. According to the invention, the method of pinning two elements such as heads is remarkable in that it consists in using a screw which ensures by its helical movement, its penetration in the heads, the abutment of its head on a first t81e, and by continuing the rotational movement the approximation of

  the second t81e to the first t81e.

  - 3 The use of a screw has the advantage of providing the tension sought quoted "tension installed" in this tightening operation. Indeed, the helical connection ensures the maintenance of an active clamping between the two t81es guaranteeing a good positioning for the permanent fixing operation. Another advantage resides in the capacity to remove by unscrewing this fixing means and

  to be able to possibly reuse it.

  Thus, the pinning method of the invention avoids the loss of the pinning elements or the use of

  reusable means but particularly expensive.

  Another advantage of using a screw for pinning is that it does not require access from both

sides of the t81es.

  Nevertheless, the introduction of a screw is not always possible without the realization of a thread. This thread would require a particularly long and therefore expensive tapping operation for a pinning phase. Also, the applicants have advantageously imagined the use of a self-drilling or self-forming screw allowing one or the other to ensure the production of the thread as and when they are penetrated by

their helical movement.

  Although it is a particularly common means of fixing, the screw has never been considered in the context of pinning because it has always been

  considered a permanent means of fixation.

  The use of this means of fixation therefore constitutes the suppression of a technical prejudice in the specific context of the intended application, that is to say

  docking of t81es and in particular pinning.

  In addition, this screw is used as a means of bringing the movement closer together when its head comes into abutment well before using its conventional tightening function.

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  Other advantages and other characteristics will appear more clearly on reading the

  description below which gives as an example not

  limiting and with regard to the accompanying drawings, several

  embodiments of a pinning process and

  means to implement it.

BRIEF DESCRIPTION OF THE DESSlNS

  Figures la, lb, lc, ld, schematic sectional views of a first embodiment of the pinning method of the invention, Figures 2a, 2b, 2c, 2d, schematic sectional views of a second embodiment of the pinning method of the invention, FIG. 2e is a section of the screw used in

this embodiment.

  The illustration of the embodiments of the process of

  the invention as well as the means for implementing it is reduced to a point of attachment for more

of clarity.

DESCRIPTION BASED ON THE DESSlNS

  As illustrated in the drawings of the assembly of figures, two heads 100 and 200 to be fixed to each other, each provided with an orifice 110 and 210, the orifice of a first head being coaxial with the orifice of

the second t81e.

  According to the embodiment illustrated in Figures la to ld, the pinning method of the invention is remarkable in that it consists in making orifices and 210 of different diameters on the tabs 100 and 200, the t81e 100 serving of support to the head 310 of the screw 300 being that receiving the orifice 110 of diameter

  greater than that of port 210.

  According to the invention, the pinning method is remarkable in that it consists in using a screw 300 which, introduced into said orifices 110 and 210, ensures by its helical movement, its penetration in the t81es, the abutment of its head 310 on the first t81e 100 and by continuing the rotational movement, the approximation of the second sheet 200 with the first

t81e 100.

  This process follows the steps illustrated by

figures la, lb, lc, ld.

  As illustrated in the drawing in FIG. 1a, the screw 300 is introduced into the orifice 110 of the upper t81e and comes to be introduced in a normal helical movement of screwing into the orifice 210 of the

t81e lower 200.

  According to a nonlimiting embodiment, the fixing means making it possible to implement the method

  described, is a self-forming screw.

  In this case one of the holes would not be drilled, the fixing means making it possible to set in motion the

  described process would be a self-drilling screw.

  Thus, the prior realization of a front hole of larger diameter in the first sheet in which the screw 300 is introduced has the advantage of not creating during the tapping operation carried out by the helical movement of the screw in the second t81e, of chips between the t81es due to the absence of contact

  during the crossing of the first t81e.

  As illustrated in the drawing in Figure 1b, the screw 300 once introduced into the second t81e 200, why-its helical movement by making a thread on the inner surface of the orifice 210, until the head comes in abutment on the first t81e 100 crossing. Indeed, according to one embodiment, the method consists in carrying out a tapping on at least one orifice 210. This method can be implemented

  in operation by a simply self-tapping screw.

  As illustrated in the drawing in FIG. 1c, once its head 310 abuts on the first sheet 100, the movement of the screw 300 is no longer a helical movement but a rotational movement. With the thread created by the helical movement, the second sheet 200 whose rotation is advantageously prevented, is moved under the action of the movement of the screw, in translation to approach the first t81e until

touch her.

  As illustrated in the drawing in FIG. 1d, the two soles are juxtaposed, the rotation of the screw 300 is implemented until a pressure is placed between them, pressure which guarantees good positioning

  t81es between them for the next operation.

  Such a fixing method ensures optimized maintenance of the t81es between them for the following operation of permanent fixing which will be conventionally carried out by

riveting.

  In order to avoid a prior drilling operation with two different drills to make two pilot holes of different diameters before introduction of the fixing means, the applicants have advantageously imagined a particularly practical pinning process avoiding the change of tool. drilling as well as chip production. Thus, according to a particularly advantageous characteristic of the invention, the pinning method consists in making orifices of the same diameter. The implementation of this characteristic is illustrated by the drawings of Figures 2a to 2e. This process is according to a particularly advantageous characteristic of the invention, implemented by a fixing means

  consists of a self-forming type screw.

  This fixing means is particularly advantageous in that it ensures the creation of a thread on the inner surface of the orifices by deformation and not by removal of material. Also, it is not useful to make a pilot hole 110 of larger diameter in the first t81e 100 crossed by the screw to avoid - 7 - chips being inserted between the two t81es 100 and during the helical movement of screw 300, since this behind will not create it unlike

  a self-drilling or self-tapping screw.

  As illustrated in the drawing in FIG. 2a, the screw 300 is introduced into the orifice 110 of the upper plate 100 and produced by its helical movement a first thread on the interior surface of the first orifice 110 then is always introduced according to its helical movement in [orifice 210 of the sheet

lower 200.

  As illustrated in the drawing of Figure 2b, the screw 300, once introduced into the second sheet 200, for -quit its helical movement by making another thread on the inner surface of the hole 210, until the head 310 comes to a stop on the

first sheet 100 crossing.

  As illustrated in the drawing in FIG. 2c, once its head 310 abuts on the first sheet 100, the movement of the screw 300 is no longer a helical movement but a rotational movement. Thus, according to a particularly advantageous characteristic of the invention, the pinning process consists here, of continuing the rotational movement and of destroying the

  thread created in the first sheet 100 crossed.

  Simultaneously, with the thread created by the helical movement, the second sheet 200 whose rotation is advantageously prevented is moved under the action of the movement of the screw, in translation to

  bring the first t81e 100 closer to touching it.

  Thus, the continuous rotation of the screw then has two consequences: the progressive approximation of the second sheet 300 towards the first 100 as well as the voluntary destruction of the thread created in the first sheet 100

  when inserting the screw 300.

  According to a technological choice particularly

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  judicious, the first thread of the screw used to implement the process starts as teas possible as possible so that the torque necessary for the destruction of the first thread is less than that necessary for the final tightening of the two soles and the installation of the tension sought. As illustrated in the drawing of Figure 2d, the two t81es wind juxtaposed, the rotation of the screw 300 is implemented until the establishment of a pressure between them, pressure which guarantees a good positioning of the t81es 100 and 200 between them, for the operation

following permanent fixation.

  According to a mode of real i sati we prefer the fixing means illustrated by the drawing of figure 2e, the self-forming screw is constituted by a screw of the type of that

with three-lobed stem.

  Of course, this self-forming screw with a trilobed rod or not, can be used for the first mode of

  carrying out the method of the invention.

  It is understood that the pinning method and the fixing means allowing it to be implemented which have just been described and represented above, have been intended for disclosure rather than for limitation. Of course, various arrangements, modifications and improvements can be made to the example above, without going beyond the ambit of the invention.

as claimed.

Claims (10)

  1. Method for pinning two elements such as tales (100 and 200), CHARACTERIZED IN THAT it consists in using a screw (300) which ensures by its helical movement, its penetration in the t81es (100 and 200), the abutment of its head (310) on a first t81e (100), and by continuing the rotational movement, the bringing together of the second t81e (200) towards the first tale (100).   2. A method of pinning two elements such as plates (100 and 200) according to claim 1 in which two practical coaxial orifices (110 and 210) have been used, CHARACTERIZED IN THAT it consists in using a screw (300) which , introduced into said orifices (110 and 210), ensures by its helical movement, its penetration in the plates (100 and 200), the abutment of its head (310) on a first plate (100), and by continuation of the rotational movement, the approximation of the second   sheet (200) with the first sheet (100).   3. A pinning method according to claim 2, CHARACTERIZED IN THAT it consists in making orifices (110 and 210) of different diameters on the heads (100 and), the head (100) serving to support the head. (310) being   that receiving the orifice (110) of greater diameter.   4. pinning method according to claim 2, CHARACTERIZED IN THAT it consists in making orifices (110 and (210) of the same diameter.   5. Pinning method according to claim 2, CHARACTERIZED IN THAT it consists in making a thread on at least one orifice (210).   6. pinning method according to claim 2, of the type in which the diameter of the orifice (110) practiced in the first sheet (100) allows the production of a thread by helical movement of the screw (300), CHARACTERIZED IN THAT it consists in destroying the   thread created in the first tCle (100) crossed.   io 2840551 7. Fastening means (300) for implementing the method according to claim 1, CHARACTERIZED BY THE FACT THAT it is constituted by a screw (300) of the self-drilling type. 8. Fastening means (300) for implementing the method according to claim 1, CHARACTERIZED BY THE FACT THAT it is constituted by a screw (300) of the self-forming type. 9. Fastening means (300) for implementing the method according to claim 1, CHARACTERIZED BY THE FACT THAT it is constituted by a screw (300) of the trilobed type. 10. Fastening means (300) for implementing the method according to claim 2, CHARACTERIZED BY THE FACT THAT it is constituted by a screw (300) of the type