FR2480375A1 - MECHANICAL LOCKING INSERT FOR SANDWICH PANELS - Google Patents

Abstract

AN INSERT FOR SANDWICH PANELS, CONSISTING OF A BODY 19 AND A SLEEVE 18, EACH INCLUDING AN ENLARGEMENT OF THEIR INTERNAL DRILLING. THE ENLARGED BORING PART 25 OF THE BODY 19 IS DEFORMED WHEN THE INSERT IS MOUNTED IN THE WIDERED BORE 26 OF THE SLEEVE IN ORDER TO ENSURE THE MECHANICAL LOCKING OF THE SLEEVE BODY.

Description

The present invention relates to inserts used on panels

  and, more specifically, on the inserts which, once put in place, are subject to one

skins of a sandwich panel.

  The insert type, to which the present invention applies, is commonly used on panels composed of

  material forming the core and covered on both sides with

  riau, forming the skins, so as to constitute a panel. The man

  The soul's material is usually a structured foam,

  honeycomb cells, balsa or other lightweight material.

  It is highly desirable that the inserts used on

  such panels can easily be mounted in a single operation.

  without having to use special tools and without having to

  resort to long processes, such as lining or others.

  The currently known inserts are

  killed from a portion forming the body of essentially cylindrical shape.

  drique, which at one of its extremities flares radially outwards. The body is usually longitudinally pierced

  at its center and tapped to receive a threaded element

  tion. The part forming this body is stuck in a sleeve, also of substantially cylindrical shape. The insert, once installed, the outer skin of the sandwich panel is wedged between the body and the sleeve, so as to provide the panel with a threaded hole. This jamming, to which is added the friction

  between the body and the sleeve, can not oppose

  a resistance to the fastening element

  only at the cost of strict control of dimensional tolerances

  the plating, hardness and malleability of the sleeve and body parts. However, experience has shown that, even when such quality checks are carried out, the insert

  often gives rise, it seems, to the wide variety of

  these tearing that we encounter in practice.

  The present invention consists of an insert, intended to be mounted in a sandwich panel, of external appearance similar to that of the currently used inserts. The insert of the present invention, however, consists of a body and a

  each with an enlargement of their internal piercing

  no, a short distance from the end of the insert

  which comes to touch the inner face of the skin of the sandwich panel.

  When mounting the insert, the part of the body, whose inner diameter is widened, deforms by crashing into the part of

  enlarged inner diameter of the sleeve, thus ensuring a lock

  mechanical lage between its two components. The insert of this

  The invention is capable of withstanding superior tearing forces

  better than inserts, whose body and sleeve are assembled only by friction. The insert of the present invention may further be manufactured without the need for such strict control of dimensional tolerances,

  veneer, hardness and malleability of its components.

  The invention will now be described in more detail by means of a nonlimiting example of embodiment described hereinafter and represented in the accompanying drawings in which: FIG. 1 is a cross-section of a sandwich panel and an insert made according to the principles of

the present invention.

  Figure 2 is a cross section of the insert shown in Figure 1; Figure 3 is an enlarged representation of the lower portion of the insert of Figure 2; FIG. 4 is an enlarged representation of the lower part of the insert of FIG. 3, after assembly of the latter, and FIG. 5 is a cross section of the insert, made according to the principles of the present invention.

and mounted on a sandwich panel.

  Referring now to Figure 1, we see an insert 10, made according to the principles of the present invention and mounted on a sandwich panel 12 composed of an upper skin 14 and a lower skin 16 enclosing a material constituting 17. The insert 10 comprises a sleeve 18 whose upper 22 and lower 23 parts are separated by a constricted portion 21 over the entire circumference of the sleeve 18. The body 19 of the insert 10 has a frustoconical upper portion 20 which is forced into the upper portion 22 of the sleeve 18 to ensure the mechanical attachment of the insert to the sandwich panel 12, as described below. As has been previously said, this external appearance of the insert 10 is

3 2480375

  similar to the appearance of the inserts currently used.

  As seen in Figures 2 to 5, the body 19 of the insert 10 has in its center a threaded hole

  24 for receiving a threaded fastener element (not shown

  you). The hole 24 of the body can be passing or blind. The interior of the lower portion 23 of the sleeve 18 comprises an enlargement

  of diameter 26, while the lower part of the body 19 com-

  also carries an enlargement of diameter 25.

  For assembly, as shown by the

  3 and 4, a force 1 is applied to the insert 10.

  An enlarged inner diameter portion 25 of the body 19 abuts against the lower skin 16 of the sandwich panel 12 and, under the effect of this force 1, the enlarged inner diameter portion 25 deforms in the enlarged diameter portion 26 of the portion lower 23 of the sleeve 18, thereby ensuring the mechanical locking of the body 19 in the sleeve 18. In addition, as shown in Figure 5, the upper skin 14 of the sandwich panel 12 is trapped between the frustoconical portion 20 of the body 19 and the upper portion 22 of the sleeve 18, which has been flared by the frustoconical portion 20 of the body 19. Due to the constriction 21 of the sleeve 18, only the

  upper part 22 of the latter is interested in the flare.

  After its assembly, the insert 10 of the present invention is capable of withstanding tearing forces P

  superior to those that can support the current inserts-

  used. The mechanical locking between the body 19 and the sleeve 18 of the insert 10, due to the deformation of the part to

  enlarged internal diameter 25 in the space left free by the

  Expanded diameter tie 26 has been designed to provide an insert 10 that can not be torn off the sandwich panel until the force P does not reach values sufficient to detach the insert 10

  of the upper skin 14 of the sandwich panel 12.

Claims (5)

R E V E N D I C A T IO N S   1. - Insert for sandwich panels of the type   with an upper skin and a lower skin that surrounds   a core of light material, characterized in that it comprises: - a sleeve (18) comprising a first and a second part, said first part (23) being designed to come, after mounting the insert, to the contact of the upper skin (16) of said sandwich panel and said second portion   with a widening of its drilling over a certain period   from its free end; a body (19) comprising a third and a fourth part, said third part (20) flaring out   gradually towards its free end, and said fourth par-   (25) having an enlargement of its piercing on a certain   length from its free end, the enlarged piercing portion of said body being deformable in the enlarged bore portion of the sleeve for mechanical locking   said body in the sleeve during assembly of the insert.   2. - Insert according to claim 1, characterized   characterized by the fact that the sleeve (18) and the body (19) are of essentially cylindrical shape.   3. Insert according to claim 2, characterized   rised by the fact that the first and second parts of the man-   chon are separated by a strangulated portion (21) over the entire circumference of the sleeve.   4. - Insert according to claim 3, characterized   characterized in that said body (19) has at its center a tapered concentric longitudinal hole (24) for receiving a threaded fixing element.-   5. Insert according to claim 4, characterized   characterized in that said tapped hole is passing.