GB1588548A - Device for use with magnetic tape cassettes - Google Patents

Description

(54) DEVICE FOR USE WITH MAGNETIC TAPE CASSETTES (71) 1, PENTTI KUOPPALA, A Finnish Citizen, of Tiirismaantie 9 B 37, Helsinki 71, Finland, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a device for use with magnetic tape cassettes to permit these to be used for re-recording.

It is usual to provide magnetic tape cassettes with means for preventing them from being used for re-recording without some some special action having been taken, the object being to ensure that an existing recording on the tape cannot be erased accidently.

In practice this has usually been done by forming two holes in the back edge of the cassette which will come in front of coupling elements provided in the recorder when the cassette is inserted into the latter. When a cassette of this type with the holes open is inserted into such a recorder no re-recording with erasure of existing recording, is possible.

A similar result has been obtained with cassettes of this kind in which the holes are normally closed by flaps which are removed, for instance by using a screw driver, after a recording has been made, in order to prevent re-recording, To allow cassettes of the above kinds to be used for re-recording, the holes in the cassette may be covered with adhesive tape.

This procedure, however, suffers from several drawbacks. Such tape is not usually kept with the cassettes and it may not be available when needed. Furthermore the adhesive tape collects dust and dirt, which also tends to stick to the surface of the cassette after the tape has been removed. Pieces of the adhesive tape may be carried into the driving mechanism of the recorder or into the cassettes themselves, as a result of which they may interfere with the operation.

Another way of allowing re-recording while preventing unintentional erasion from a recorded tape is to provide the cassette with sliding panels or lids, which can be moved into positions to close the holes if re-recording is desired. At other times the cassette is kept with the holes open. This construction, however, suffers from a number of disadvantages. The slides are unreliable in operation and often work loose, in which case they may move by themselves when the cassette is handled. Thus this arrangement is uncertain, while it also increases the price of the cassette, particularly since each cassette must be provided with its own slide or slides.

The holes in a cassette could be closed by means of separate plugs which are inserted when re-recording is required. These plugs must however be of small size, which is a disadvantage since they usually get lost. It may also be difficult to remove them from the holes if they are a tight fit. On the other hand if the plugs are a loose fit there is a risk of them getting carried into the driving mechanism of the tape recorder.

The present invention sets out to provide means for avoiding or reducing the abovementioned drawbacks and of providing a simple and reliable device which can be used to allow cassettes of the kind in question to be used for re-recording.

According to the present invention a device is provided for fitting to a magnetic tape cassette having holes in its casing which when open prevent re-recording on the tape, wherein the device comprises a body in the form of a strip having members projecting from it which are adapted to engage in the holes in the cassette to attach the device to the latter so as to cover the holes in the cassette and permit re-recording.

Preferably the projecting members are located adjacent opposite ends of a single strip which is adapted to cover both the holes in a cassette, the distance between the projecting members corresponding to the distance between these holes.

Each device may, however, be formed in two parts each of which is provided with projecting members to engage in one of the holes in the cassette.

The invention will now be more fully described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows a cassette into which a device embodying the invention can be fitted; Fig. 2 shows a device exemplifying the invention; Fig. 3 shows another embodiment of the invention; Fig. 4 is a detail view showing part of the device shown in Fig. 3 but to a larger scale.

Referring to the drawings, Fig. 1 shows an ordinary magnetic cassette 1 which can be, for instance, a so called compact cassette.

The back edge of this cassette is formed with two holes 2 and 3 and when these are open the cassette cannot be used for re-recording. The reason for this-is that the tape recorders for which such cassettes are designed have built in contact elements which are engaged and operated when a cassette is inserted into the recorder if the holes are closed or covered. On the other hand if the holes are open the contact elements are not operated by the insertion of the cassette into the recorder and recording cannot be carried out. This system is a standard one used in all generally-available cassette recorders.

Fig. 2 shows one embodiment of a device according to the invention. As shown in the drawing, this device comprises body in the form of a flat strip 4, which is formed near its ends with pairs of lugs 5 and 6. The width and spacing of these lugs is such that they fit tightly into the holes 2 and 3 in the back edge of a standard cassette. Likewise the distance between the pairs of lugs is chosen so that it corresponds to the distance between the holes 2 and 3 in the cassette.

This device can be fitted to the back of a cassette 1 so that it covers the holes 2 and 3, the device then being held in position by the resilient engagement of the lugs in the holes.

Consequently if it is desired to re-record on the tape in the cassette this can be made possible by fitting a device of the invention to a cassette. Without such a device rerecording with erasure of an existing recording is prevented.

The device described above is preferably made of a sheet of a material of uniform thickness. The sheet may be made of an artificial material such as a suitable synthetic plastics (or it might be of metal) and may be produced by stamping or pressing for example.

Fig. 3 shows another embodiment of the invention. The device shown comprises a body in the form of a strip 34 which is provided at its ends with pairs of lugs 35, 37 and 36, 38. This device may be made of a synthetic plastics material by die-casting, or moulding for example. The widths of the lugs and the distances between them are chosen so that the device can be fitted to a standard cassette with the lugs engaged in the holes 2 and 3.

Fig. 4 shows, to a larger scale, part of the body 34 of a modified device which is provided at each end with lugs 36 and 38.

As viewed in the drawing the lug 36 of each pair is generally semicircular in cross-section.

However, in order to avoid difficulties due to possible dimensional inaccuracies in the holes of the cassette, the edges of the other lugs 38 are shaped so as to have thin side extensions 49. Even if the holes 2 and 3 should be a little larger than standard, secure fastening of the device will still be possible. On the other hand, if the holes should be narrower than standard, this would not cause any difficulties, since the thin extensions 49. due to their elasticity, are easily bent td fit the holes.

Although a number of preferred embodiments of the invention have been described, modifications are possible without departing from the invention claimed. Thus the device of the invention can consist of two separate parts, each with its lugs for engaging in one hole, so that the two parts or the device are individually fitted into the two holes 2 and 3 of the cassette.

WHAT I CLAIM IS:- 1. A device for fitting to a magnetic cassette having holes in its casing which when open prevent re-recording on the tape, wherein the device comprises a body in the form of a strip having members projecting from it which are adapted to engage in the holes in the cassette to attach the device to the latter so as to cover the holes in the cassette and permit re-recording.

2. A device as claimed in claim 1, wherein the projecting members are located adjacent opposite ends of a single strip which is adapted to cover both the holes in a cassette, the distance between the projecting members corresponding to the distance between these holes.

3. A device as claimed in claim 1, wherein the strip is in two parts each of which is provided with projecting members to engage in one of the holes in the cassette.

4. A device as claimed in any of the preceding claims, which is made of a strip of fiat material and is produced in such manner as to form lugs which are bent at angles of approximately 90% to the strip and constitute the projecting members.

5. A device as claimed in any of claims J to 3, which is made of a synthetic plastics material by die-casting or moulding to form two - lugs which constitute the projecting members.

6. - A device as claimed in claim 5, wherein the lugs are of generally semicircular crosssection.

7. A device as claimed in claim 6, wherein

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. Fig. 1 shows a cassette into which a device embodying the invention can be fitted; Fig. 2 shows a device exemplifying the invention; Fig. 3 shows another embodiment of the invention; Fig. 4 is a detail view showing part of the device shown in Fig. 3 but to a larger scale. Referring to the drawings, Fig. 1 shows an ordinary magnetic cassette 1 which can be, for instance, a so called compact cassette. The back edge of this cassette is formed with two holes 2 and 3 and when these are open the cassette cannot be used for re-recording. The reason for this-is that the tape recorders for which such cassettes are designed have built in contact elements which are engaged and operated when a cassette is inserted into the recorder if the holes are closed or covered. On the other hand if the holes are open the contact elements are not operated by the insertion of the cassette into the recorder and recording cannot be carried out. This system is a standard one used in all generally-available cassette recorders. Fig. 2 shows one embodiment of a device according to the invention. As shown in the drawing, this device comprises body in the form of a flat strip 4, which is formed near its ends with pairs of lugs 5 and 6. The width and spacing of these lugs is such that they fit tightly into the holes 2 and 3 in the back edge of a standard cassette. Likewise the distance between the pairs of lugs is chosen so that it corresponds to the distance between the holes 2 and 3 in the cassette. This device can be fitted to the back of a cassette 1 so that it covers the holes 2 and 3, the device then being held in position by the resilient engagement of the lugs in the holes. Consequently if it is desired to re-record on the tape in the cassette this can be made possible by fitting a device of the invention to a cassette. Without such a device rerecording with erasure of an existing recording is prevented. The device described above is preferably made of a sheet of a material of uniform thickness. The sheet may be made of an artificial material such as a suitable synthetic plastics (or it might be of metal) and may be produced by stamping or pressing for example. Fig. 3 shows another embodiment of the invention. The device shown comprises a body in the form of a strip 34 which is provided at its ends with pairs of lugs 35, 37 and 36, 38. This device may be made of a synthetic plastics material by die-casting, or moulding for example. The widths of the lugs and the distances between them are chosen so that the device can be fitted to a standard cassette with the lugs engaged in the holes 2 and 3. Fig. 4 shows, to a larger scale, part of the body 34 of a modified device which is provided at each end with lugs 36 and 38. As viewed in the drawing the lug 36 of each pair is generally semicircular in cross-section. However, in order to avoid difficulties due to possible dimensional inaccuracies in the holes of the cassette, the edges of the other lugs 38 are shaped so as to have thin side extensions 49. Even if the holes 2 and 3 should be a little larger than standard, secure fastening of the device will still be possible. On the other hand, if the holes should be narrower than standard, this would not cause any difficulties, since the thin extensions 49. due to their elasticity, are easily bent td fit the holes. Although a number of preferred embodiments of the invention have been described, modifications are possible without departing from the invention claimed. Thus the device of the invention can consist of two separate parts, each with its lugs for engaging in one hole, so that the two parts or the device are individually fitted into the two holes 2 and 3 of the cassette. WHAT I CLAIM IS:-

1. A device for fitting to a magnetic cassette having holes in its casing which when open prevent re-recording on the tape, wherein the device comprises a body in the form of a strip having members projecting from it which are adapted to engage in the holes in the cassette to attach the device to the latter so as to cover the holes in the cassette and permit re-recording.

2. A device as claimed in claim 1, wherein the projecting members are located adjacent opposite ends of a single strip which is adapted to cover both the holes in a cassette, the distance between the projecting members corresponding to the distance between these holes.

3. A device as claimed in claim 1, wherein the strip is in two parts each of which is provided with projecting members to engage in one of the holes in the cassette.

4. A device as claimed in any of the preceding claims, which is made of a strip of fiat material and is produced in such manner as to form lugs which are bent at angles of approximately 90% to the strip and constitute the projecting members.

5. A device as claimed in any of claims J to 3, which is made of a synthetic plastics material by die-casting or moulding to form two - lugs which constitute the projecting members.

6. - A device as claimed in claim 5, wherein the lugs are of generally semicircular crosssection.

7. A device as claimed in claim 6, wherein

at least one of the two lugs, which engage in the respective holes, is formed along its opposite edges with extensions which are thinner than the lug itself.

8. A device as claimed in claim 1, substantially as herein described with reference to the accompanying drawings.