LU80473A1 - METHOD FOR MANUFACTURING A SUN VISOR, PARTICULARLY FOR A MOTOR VEHICLE, OF THE TYPE INCLUDING A MIRROR - Google Patents

Description

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The present invention relates to a method of manufacturing a sun visor, t; in particular a motor vehicle pouf, of the type comprising a courtesy mirror and produced by molding a foam inside a thermoplastic cover. two parts, in a mold comprising two complementary half-shells. '.

5 - The manufacture of sun visors fitted with a mirror poses many problems which have not yet found entirely satisfactory solutions. For example, the cap constituting the coating of these sun visors, generally made of polyvinyl chloride, has insufficient rigidity to properly maintain the mirror. It is true that solutions aimed at stiffening the cap 10 have been proposed, but they however prove to be complicated and expensive.

Experience has also shown that the mirrors of current sun visors are not perfectly integral with the foam. So that in the event of breakage, the pieces of mirror detach freely, which can cause serious injuries. ^ j safe for the passenger of the vehicle.

15 · · The present invention proposes to remedy these drawbacks and, to do this, it relates to a method of manufacturing a sun visor which is characterized in that it consists successively in fixing one of the elements of the cap .. on a thermoplastic sheet thicker than him and whose dimensions correspond. substantially - to those of the mirror, by high frequency welding along a line corresponding to the outline of the window of said mirror, to cut the element of (.... cap and the thermoplastic sheet along the line of. welding, to place the openwork pattern thus obtained on the 'lower half-shell of the mold * the thermoplastic feui-llo then being at the bottom of the half-shell, above the cap element, to place the mirror on the thermopJastic sheet, apply the vacuum under the mirror, pour a foaming composition, inside the lower half-shell, place on it the second cap element, put *** ' in place the upper half-shell to close, the mold, and to level the free edges of the cover elements after expansion and demoulding. -. Thanks to this process, the cover element receiving the mirror is stiffened. in a simple and fast way. Its stiffening is in fact obtained thanks to its high fre quence, practiced only at the level of the contour of the window of the. mirror, on the thermoplastic sheet.

Cutting along the weld line also makes it possible to obtain a finished product with perfect aesthetics.

35 Furthermore, the mirror is completely integral with the foam so that if it breaks, its pieces remain in place on the sun visor, and therefore cannot cause injury.

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According to a preferred embodiment of the method, it is advantageous to use a lower half-shell having on the bottom of its cavity a Uo boss whose perimeter corresponds to the contour of the window of the mirror and whose

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2 "* ·,. Λ height corresponds to the thickness of the openwork assembly, this boss being provided on • its upper face with a chamber communicating with a vacuum tube passing through the bottom of the half-shell.

- - 'The-boss indeed allows a precise centering of the perforated assembly on 5 the bottom of the cavity of the lower shell. It also constitutes a stable support for the mirror when the foam expands. As for the vacuum chamber, it allows the mirror to be firmly pressed against the thermoplastic sheet,. - · this. which prevents it from moving accidentally during molding.

Preferably, the boss is constituted by an insert part intro-10 pick in a housing made in the bottom of the cavity of the lower half-shell.

Thanks to this arrangement which makes it possible to adapt bosses of different heights to the lower half-shell by simply replacing the insert ^), it is possible to stiffen the cover element with thermoplastic sheets of different thicknesses. without affecting the stability of the mirror or the accuracy of its centering.

According to a particular characteristic of the process according to the invention, it is advantageous to place a seal of sufficient cross section at the periphery of the vacuum chamber so that the mirror is pressed against it.

A better seal can indeed be ensured between the contact surfaces j of the. mirror and. thermoplastic sheet.

A way. of. Execution of the present invention is given by way of example in the appended drawing in which: - Figure 1 is a partial plan view of a cover element fixed on a thermoplastic sheet serving to stiffen it; - Figure 2 is a sectional view along the line III - III of Figure 1;

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- Figure 3 is a schematic sectional view of a mold in use for the manufacture of a sun visor according to the invention; .and: the figure is a sectional view of the sun visor after demolding. · 30 The sun visor shown in Figure U essentially comprises a •• cover made of thermoplastic material, for example PVC, consisting of two elements 1,2, containing a synthetic foam '3 to which they strongly adhere, and one. mirror U, which may be made of metallized glass or plastic material „the window 5 of which opens onto a cut of corresponding shape made in element 1.

35 In its part adjacent to the periphery of the mirror, the element 1 is internally stiffened by a thermoplastic sheet 6 which is thicker than it and whose dimensions are substantially the same as those of the mirror.

To make the openwork assembly constituted by the element 1 and the sheet 6, the procedure is as follows i 1 * 0 First, the element 1 and the sheet 6 3 * are welded at high frequency.

> · * Τ along a line T visible in Figures 1 and 2 and corresponding to the outline of window 5 of the mirror. Referring in particular to FIG. 2, it will be noted that the weld line is in the form of a narrow channel at section. U-shaped, made in sheet 6 and clad externally with the element t.

5 When welding is carried out, the sheet 6 and the element 1 are cut at the bottom of the channel, preferably in the immediate vicinity of its outer wall, which makes it possible to obtain a clean and clean cutting line. along which sheet 6 will not be visible on the sun visor. * ·

It should be noted here that the cutting operation could be carried out 10. at the same time as the high frequency .soldering operation.

The openwork assembly being prepared, we then proceed to molding the barrier. . .sun dans.un mold of the type shown in Figure 3.

As can be seen in this figure, the mold used comprises a lower half-shell Ö and an upper half-shell 9 each comprising a complementary molding cavity.

The bottom of the cavity of the half-shell 8 has a boss 10 whose perimeter and height correspond respectively to the outline of the window 5 of the mirror and to the total thickness of the sheet 6 and of the element 1. On its fac <superior, the boss comprises a-chamber 11 provided with a seal 12 20 at its periphery and communicating with a vacuum tube 13 passing through the bottom of the. | half shell.

In the example shown, it will be noted that the boss 10 is constituted by an attached part disposed in a suitable housing produced in the bottom of the cavity of the half-shell 8.

25 lift molding is. realizes as follows: ^ i Place the openwork assembly-on the half-shell 8 so that the boss penetrates into the cutout corresponding to the window of the mirror, the sheet 6 being turned upward-while the periphery of element 1 rests on supérieure the upper face of the half-shell. The boss naturally allows precise positioning of the perforated assembly.

. We then place the mirror k on the sheet 6, after which we apply 1. . empty in the chamber 11, which allows the mirror to be held correctly in place Ï1 should be noted that a perfect seal between the mirror and the sheet 6 is ensured by plane-to-plane contact.

35 A foaming composition is then poured onto the mirror · which is therefore pressed against the sheet 6 under the action of the vacuum prevailing in the chamber 11 and maintained by the seal 12, after which the cover element is placed 2 on the half-shell 8, then the mold is closed with the upper half-shell 9.

When the expansion of the foam is complete, the mold is removed from the mold and the free edges of the elements 1 and 2 are leveled off, which cannot be seen on the crack. . 11% V, 1 d- The manufacturing process according to the invention allows the production of a sun visor whose cap elements are integral with the foam which ensures their connection au.niveau their periphery and whose mirror is perfectly anchored. Oh, it is easy to see that this improved anchoring, security, 5 since in the event of the mirror breaking, the resulting pieces cannot separate from the foam.

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Claims (5)

5 * en - 1) Manufacturing process, of a sun visor, in. particular for a motor vehicle, of the type comprising a courtesy mirror and produced by molding a foam inside a two-part thermoplastic cover, in a mold 5 comprising two complementary half-shells, characterized in that it consists „successively to fix by high frequency welding and only along a line corresponding to the outline of the window of the mirror, a thermoplastic sheet on one of the elements of the cap, this sheet being thicker than the element of cap and having dimensions corresponding substantially to those of the mirror, cutting the cover element and the thermoplastic sheet along their fixing line, placing the perforated assembly thus obtained in a half-shell of the mold, the element cap being in contact with this half-shell, to ensure the maintenance of the mirror against the thermoplastic sheet, to ('pour a foaming composition inside the half-shell, to put in 1 5 places the second cover element, to close the mold with the second half-shell, to be removed from the mold after expansion of the foam and to level the free edges of the cover elements. 2. Method according to claim 1, characterized in that the mirror is held against the thermoplastic sheet by applying vacuum under it. 3) Method according to claim 2, characterized in that the half-shell receiving the perforated assembly has on the bottom of its cavity a boss whose perimeter corresponds to the outline of the mirror window and whose height corresponds to the thickness of the openwork assembly, this boss being provided on its upper face with a chamber communicating with a vacuum tube passing through the bottom of the half-shell. 4. Method according to claim 3, characterized in that the boss consists of an insert introduced into a housing made in the bottom of the cavity of the half-shell. 5. Method according to claim 3 or 4, characterized in that it consists in placing at the periphery of the vacuum chamber a seal of sufficient cross section for the mirror to bear against it. 6. A mold comprising a half-shell conforming to that used for the implementation of the method according to claim 3 or 4. ^ - 7) Sun visor manufactured by the implementation of the method according to any one 35 qUe of claims 1 to 5.