DE7708727U1 - SLIDING FILM FOR TAPE CASSETTES - Google Patents

Description

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Wiliich 3 - sloping track
Am Nordkanal - P.O. Box 80

Sliding film for clay bond cassettes

The present innovation relates to a partially transparent sliding film For tape cassettes. Such a two-half cassette is usually made of plastic with a window opening to it Control of the belt run injected, this opening is then injected closed by a transparent film inserted by inside. It is Also common, the window opening through a welded or blown to close the transparent plastic part.

The effort involved in blowing in or welding in the window means an additional work step. Sealing by means of an inserted film means that the cassette is first equipped with a transparent film as a seal on both surfaces and then with an inner sliding film for the running of the tape; the sliding film is usually antistatic. The antistatic finish is generally achieved in that the sliding film is filled with carbon and thus becomes opaque. At the point of the window opening, the inner sliding foils are therefore provided with an opening that is punched out during manufacture.

The area of responsibility of the innovation lies in the previous one To make the tape cassettes cheaper and to improve. This is achieved by making the anti-static sliding film, which is required anyway, transparent in the area of the window is trained. The antistatic finish is above all else required in the winding area of the tape, while in the central area between the two coils, in which the control window is also located, the antistatic equipment is of lesser importance.

7708727 11/03/77

This knowledge has already led to the development of a
"Three-zone film" out, which denotes a polyester film
is coated on one or both sides with graphite, wherein
the middle of the film in the window area remains uncoated.

The task of the innovation is specifically to use a sliding film, the production of which is cheaper and simpler than the previous state of the art, and which at the same time means an improvement in the function of the cassette. According to the innovation, this is achieved
in that a high quality sliding film, for example according to GM 75 15 122, which is antistatic and through the
Carbon content appears deep black, is only used for the two winding areas of the tapes, in the window area they are
carbon-filled strips homogeneously connected with a transparent film strip. The composite films composed in this way are largely free of abrasion, while the electrically conductive material applied to the coated three-zone polyester film is rubbed off in the course of use and the sound reproduction quality deteriorates.

The transparent film center strip can consist of the same plastic material, but which is not filled with carbon and is therefore transparent. The connection of the transparent film part with the two antistatic side parts can be done by
Sintering, fusing or welding take place. However, since the welding of the film strips is an additional costly process
Due to the operation, the film strip serving as a semifinished product is expediently inserted into the film strip, which is used as a semi-finished product, before the sliding film inserts are punched out
made of this composition. This can e.g. B. can be achieved in that the blank, from which the sliding film is made by peeling, consists of individual disks or layers that are correspondingly differently composed. It stands to reason that the

7708727 03.1177

Block from which the film strips serving as semi-finished products are peeled off can have a corresponding number of different disk-shaped layers following one another in the axial direction.

An exemplary embodiment of the innovation is shown in the drawing,

daring shows:

Image 1

The supervision of a sliding film according to the innovation consisting of

three areas,

picture 2

a corresponding film strip serving as a semi-finished product, in which the outlines of the parts to be punched out subsequently

picture 3

a block of foils made of layers / disks for peeling off the corresponding strips of semi-finished products.

In picture 1 are the two static parts of the sliding film labeled la and Ib, while 2 denotes the transparent central part the sliding film shows. With 3 the cutouts for the area of the hubs of the tape reels are designated, while 4a and 4b Show recesses for fixing the position of the sliding film in the cassette.

In picture 2 is a film strip with the three zones la, Ib and 2 shown, the later to be punched therefrom sliding film inserts for the cassettes are indicated.

Figure 3 shows one of corresponding disk-shaped layers existing film block for peeling off film strips according to picture The seams between the individual film strips are partly under 5 indicated.

7708727 03.1177

Claims (3)

PROTECTION CLAIMS Partly transparent slide film for inserting into tape cassette.i, characterized in that the transparent central area of the sliding film with the two opaque, antistatic side areas homogeneously by sintering or welding or Merging is connected. 2. Sliding film according to claim 1, characterized in that the Transparent middle part made of chemically identical plastic only in a non-antistatic, i.e. unfilled modification consists. 3. Sliding film according to claim 1, characterized in that the transparent middle part and the two side parts made of chewish - ^ There are different plastics, but they are interrelated let connect. 7708727 03.1177