DE8633679U1 - Slat for shutters or blinds - Google Patents

Description

The invention relates to a blade for light-optical shutters and apertures of optical devices, e.g. photographic cameras or photographic lenses.

Such blades must meet high requirements in terms of strength and rigidity. At the same time, however, the mass must be as low as possible in order to be able to achieve ever shorter shutter speeds.

In order to at least approximately meet these requirements, the slats are manufactured from steel, titanium or aluminum sheet in the state of the art, whereby bead reinforcements or etched profiles can be provided.

The invention is based on the task of improving the slats in terms of their specific strength and rigidity without having to increase the mass of the slats. Rather, the aim is to reduce the mass.

This object is achieved according to the invention by a structural fiber composite material, which preferably has carbon or aramid fibers embedded in a synthetic resin matrix, preferably a thermoplastic matrix.

Theodor-Heuss-Strasse 2 D-3300 Braunschweig

Federal Republic of Germany

Telephone Telex Tetegrar

0531-80079 0952620grammd se Patent Braunschweig

ttftCC

A three- or multi-layer design of the lamellae has proven to be advantageous.

j In a special embodiment, it is provided that in a three-layer design the middle layer has an approx. 60 %

'< Carbon fiber prepreg is pressed on both sides with a carbon fiber fleece or fabric.

; the unidirectional fibers in a prepreg are preferably in the longitudinal direction of the lamella.

In an alternative solution, if the lamella is designed in three layers, all three layers can consist of the prepreg mentioned, with the fibers in the two outer layers running in the longitudinal direction of the lamella, but in the middle layer running approximately transversely to this.

However, with a three-layer design of the lamella, it is also possible that only the two outer layers consist of the aforementioned prepreg, whose fibers are again oriented in the longitudinal direction of the lamella, while the middle layer consists of a carbon fiber fleece or fabric.

The slat is subjected to particularly high _loads in the area of its axis of rotation and in the area of action of the elements controlling the slat. According to the invention, additional reinforcement layers can be provided in particular in these load-critical areas.

' Lamellas according to the invention are superior to conventional designs in terms of specific strength and rigidity and also have a lower mass. This allows shorter shutter times and a higher fatigue strength. An additional advantage of a carbon fiber laminate system is the matt black surface that would otherwise have to be produced separately .

The drawing shows four embodiments of the invention as examples. Figures 1 to 4 each show a three-layer slat with a different structure in the same representation.

In the lamella according to Figure 1, the middle layer consists of an approximately 60 % carbon fiber prepreg 1, which is pressed on both sides with a carbon fiber fleece or fabric 2. It can be seen that the unidirectionally oriented fibers in a prepreg run in the longitudinal direction of the lamella.

In the lamella according to Figure 2, all three layers consist of a prepreg 1, with the fibers in the two outer layers running in the longitudinal direction of the lamella and in the middle layer running approximately transversely thereto.

In the embodiment according to Figure 3, the layers are swapped in comparison to the design according to Figure 1: The two outer layers each consist of a prepreg 1, with the fibers oriented in the longitudinal direction of the lamella, while the middle layer consists of a carbon fiber fleece or fabric 2.

Figure 4 shows that the lamella shown is constructed in three layers in its main part, but has additional reinforcement layers 3 in its load-critical areas.

The alternative solutions shown in Figures 1 to 3 can also be implemented analogously for slats with five or seven layers, for example.

Gr/Gru.

Claims (1)

1. Blade for light-optical shutters and apertures of optical devices, e.g. photographic cameras or photographic lenses, characterized by a structural fiber composite material. 2. Slat according to claim 1, characterized in that the structural fiber composite material comprises carbon or aramid fibers which are embedded in a synthetic resin matrix, preferably a thermoplastic matrix. 3. Slat according to claim 1 or 2, characterized by a three- or multi-layer design. 4. Slat according to claim 3, characterized in that in a three-layer design the middle layer is an approximately 60 % carbon fiber prepreg (1) which is pressed on both sides with a carbon fiber fleece or fabric (2). (Figure 1) 5. Slat according to claim 4, characterized in that the unidirectional fibers of the prepreg run in the longitudinal direction of the slat. Theodor-Heuss-Strasse 2 D-3300 Braunschweig Federal Republic of Germany Telephone 0531-80079 Telex 09 52 620 gramm d Telegram address Patent Braunschwelg &bull;t
· I&mdash;» I t I >&Lgr; Slat according to claim 3, characterized in that in a three-layer design, all three layers each consist of an approximately 60 % carbon fiber prepreg (1), the fibers in the two outer layers running in the longitudinal direction of the slats and in the middle layer running approximately transversely thereto. (Figure 2) Slat according to claim 3, characterized in that in a three-layer design the two outer layers each consist of an approximately 60 % carbon fiber prepreg (1), the fibers of which are oriented in the longitudinal direction of the slat, while the middle layer consists of a carbon fiber fleece or fabric (2). (Figure 3) 8. Slat according to one of the preceding claims, characterized in that additional reinforcement layers (3) are provided in its load-critical areas. (Figure 4) Patent attorneys
Gram + Lins
Gr/Gru.