AU4373601A - Video head cleaning tape - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventor: Address for Service: Olbertz Holdings Pty Ltd Ralph Olbertz Gordon H Stuart CULLEN CO., Patent Trade Mark Attorneys, 239 George Street, Brisbane, QId. 4000, Australia.

Invention Title: Video Head Cleaning Tape Details of Associated Provisional Application: Australian Patent Application No.

PQ7381 filed 8 May 2000 The following statement is a full description of this invention, including the best method of performing it known to us: THIS INVENTION relates to a device for cleaning the playing and/or recording head(s) of a video tape player/recorder. In particular, the invention is directed to a video head cleaning tape cassette suitable for use in a variety of video cassette recorders (VCRs).

BACKGROUND ART There are many known devices for cleaning the heads of video recorders, and examples can be found in Australian patents nos. 538554, 541655, 545853, 570527, Australian patent application no. 72022/87, and U.S. patents nos. 4498113, 4580185 and 4387411.

The known VCR head cleaners are normally in the form of a cassette having a cleaning tape mounted on a pair of spools therein. When the cassette is inserted into the VCR and the PLAY button actuated, the i cleaning tape is brought into contact with the drum containing the head(s) to be cleaned. Each head is cleaned by virtue of the rotation of the head surface against the cleaning tape.

There are different types of VCRs, and the known VCR head cleaners are not suitable for all types. In particular, the earlier model VCR head cleaners are not suitable for some of the more recent VCRs such as the S 20 so-called "quick load" or "half load" VCR machines. When some of the known head cleaning cassettes are inserted into quick load or half load machines, the cleaning tape is pulled from the cassette housing to a greater extent than its design specifications would normally permit.

The operating components of VCRs are very sensitive, and if a *25 spindle or other operating component senses a resistance to rotation greater than a certain level, this will normally activate a shut-off mechanism in the VCR. The use of some of the earlier cassette cleaners in later model VCRs often causes the VCR to shut down on the assumption that there is a stuck tape in the VCR. Consequently, the VCR must be taken apart and recalibrated.

Cleaning cassettes which are designed specifically for use with newer model VCRs may not be suitable for use with earlier VCRs still in use.

Australian patent no. 669220 discloses a head cleaning cassette having a spring loaded cleaning tape. One end of the tape is connected to a spring which permits the cleaning tape to be extracted from the cassette to a varying extent, thus making the cleaning cassette suitable for different types of VCRs.

Although the cleaning cassette of Australian patent no. 669220 is suitable for use with different types of VCR, it has been found that it is not suitable for all types of VCR, particularly the latest models. The spring connected to the end of the cleaning tape must be less than a predetermined length in order to fit within a standard cassette housing, and the spring length limits the amount of tape which may be extracted from the cleaning cassette.

Furthermore, it is difficult to achieve a constant tension on the cleaning tape if the tape is pulled out too far. Excessive tension on the cleaning tape may result in inadvertent shut-off.

15 It is an object of this invention to provide an improved video cleaning cassette which is suitable for use in a wide range of VCR machines.

SUMMARY OF THE INVENTION In one broad form, the invention provides a device suitable for cleaning a head of a video cassette recorder, the device comprising a cassette housing having at least one spool therein, and a length of cleaning tape at least partially wound on the spool, characterised in that the spool is ego• spring-loaded to impart tension to the tape while permitting the tape to be at least partially extracted from the housing during its operation.

In use, when the cassette housing is inserted into a VCR or similar video player/recorder, a length of cleaning tape is extracted from the cassette housing by pulling the cleaning tape off the spool. (In some VCRs, the PLAY button must be pressed before the tape is "laced As the tape is pulled off the spool, the spool rotates against the bias of its spring to allow the tape to unwind. The spring maintains a tension on the tape. When the tape is released by the VCR at the end of the cleaning operation, the spool automatically rotates under its spring-bias to retract the cleaning tape.

Preferably, a spiral spring is provided within the hub of the spool. However, any other suitable spool biasing mechanism may be used, such as a rubber band, coil spring, etc.

The head cleaning tape of this invention performs a similar function to that of Australian patent no. 669220. However, since the spool is spring-loaded rather than the tape itself, a much longer tape can be used and any excess tape is wound around the spool. This allows a much longer length of tape to be extracted from the cassette during the cleaning operation. Yet, the head cleaning tape can be used with machines which require a shorter length of tape to be extracted from the cassette. The head cleaning tape is therefore suitable for use with most, if not all, known VCRs.

A particular advantage of the spiral spring is that it maintains a generally constant tension on the tape regardless of the amount of tape extracted from the cassette.

15 The cassette may include an aperture on the front thereof to enable the tape exposed through the aperture to be wetted with cleaning fluid.

The tape is suitably chamois leather or other suitable cleaning material.

Typically, one end of the cleaning tape is wound around the spool, and the other end is secured at a fixed point on the cassette housing.

20 The length of the cleaning tape is selected to be long enough to accommodate the various types of VCRs on which the cleaning cassette may be used.

The cassette may suitably include a second length of cleaning tape having one end secured at a fixed point on the cassette housing and its other end wound around a second spool within the housing. The second length of tape may be used to provide "dry" cleaning of the video head.

In order that the invention may be more fully understood and put into practice, a preferred embodiment thereof will now be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional plan view of a video head cleaning cassette according to one embodiment of the invention, Fig. 2 is a sectional plan view of the cassette of Fig. 1 in operation, Fig. 3 is an exploded view of a spring-loaded spool assembly of the cassette, Fig. 4 is an underside perspective view of the spool of Fig. 3, Fig. 5 is a perspective view of the assembled wound spool assembly of Fig. 3.

DESCRIPTION OF PREFERRED EMBODIMENTS Figs. 1 and 2 illustrate a video head cleaning tape according to one embodiment of the invention. A cassette 10 of generally conventional shape houses a first spool 11 having a length of cleaning tape 12 partially .0wound thereon. More specifically, one end of the cleaning tape 12 is secured 15 to a fixed point 9 on the front of the cassette housing 10, and the other end of the cleaning tape 12 is wound around the spool 11. The wound end of the S°tape 12 is fixed to the spool 11 in any suitable manner, e.g. by mechanical fixing or by adhesive.

The spool 11 is spring-loaded. In the illustrated embodiment, a spiral spring 13 is located under spool 11. The spiral spring 13 is a flat metal strip wound into a coil or spiral. The spiral spring has one end secured to a fixed point 14 on the cassette housing (Fig. and its other end secured to a 000.0 fitting 15 on the underside periphery of the spool hub (Fig. The spring is wound to provide a predetermined pre-tension to the cleaning tape 12. This 25 tension is low so as not to hinder the cleaning tape 12 being extracted from the cassette 10 during the cleaning operation (as described later), yet the tension is sufficient to keep the tape 12 retracted when the cassette is not in use.

The cleaning tape 12 is suitably a length of chamois or other non-abrasive material suitable for cleaning a video head. The cover flap at the front edge of the cassette is omitted from the drawings for clarity. This cover flap may include an aperture to permit cleaning fluid to be placed on the cleaning tape 12. In this manner, the cleaning tape 12 functions as a "wet" cleaner.

The cleaning cassette 10 may include a second length of cleaning tape 16 having one end secured to the fixed point 9 on the front edge of the cassette 10 and its other end wound on a second spool 17. The second spool 17 has a toothed peripheral edge 18. A pawl-like detent arm 19 engages the toothed edge 18 and prevents the spool 17 from rotating.

However, the detent arm 19 is disengaged from the spool 17 when flap 20 on the cassette housing is lifted. The spool 17 is normally the driven spool of a video cassette.

The operation of the cassette 10 is shown in Fig. 2. When the cassette 10 is inserted into a VCR, guide members 21, 22 extract the lengths of cleaning tape 12, 16 from the cassette and pull them around the video drum 23 containing the video heads. In older VCR models, the cleaning tapes 15 12, 16 are not "laced up" around the drum 23 until the PLAY button is pressed. The "wet" cleaning tape 12 is pulled from the spool 11 and, as it unwinds from the spool, it causes the spool to turn against the bias of the *spiral spring 13. This spring maintains a generally constant tension on the 2 tape 12. Moreover, only as much tape as is needed is unwound from the spool 11 and the remaining tape remains wound on the spool. The amount of tape 12 wound on the spool initially is selected to be sufficiently long to accommodate all types of VCRs on which the cleaning cassette 10 might be used.

When the cassette 10 is inserted in the VCR, the flap 20 is lifted 25 by a VCR mechanism to cause the detent arm 19 to release the toothed edge 18 and allow the spool 17 to rotate freely. Hence, the "dry" tape 16 can be pulled from the spool 17 by the guide member 22.

When the EJECT button is pressed (or, in older VCR models, when the STOP button is pressed) the guide members 21, 22 move to the cassette 10 to allow the cleaning tapes 12, 16 to be retracted. The springloaded spool 11 rewinds the "wet" cleaning tape 12 through the action of the spiral spring 13. The spool 17 is rotated by a VCR spindle mechanism to rewind the "dry" cleaning tape 16.

Figs. 3 5 illustrate the construction of the spring-loaded spool assembly in more detail. As shown in Fig. 3, a spiral spring 13 is located between the spool 11 and the base of the cassette housing 10. One end of the spiral spring 13 is fixed to a fitting 14 on the cassette base 10, and the other end of the spiral spring 13 is fixed to a fitting 15 on the underside of the spool 11. In the finished assembly shown in Fig. 5, the spiral spring 13 is largely concealed under the hub of the spool 11. A cover 11A is suitably provided on the spool 11. A cleaning tape (not shown) is wound on the spool 11 and its end can be affixed to fitting 11B on the spool 11 in a known manner. The tape may be pulled so that the spool is turned against the bias of the spring before the other end of the tape is secured to the cassette housing, to thereby pretension the cleaning tape.

The foregoing describes only one embodiment of the invention 15 and modifications which are obvious to those skilled in the art may be made thereto without departing from the scope of the invention.

For example to provide smooth unrestricted movement of the spring 13, a lubricating disc such as a TEFLON T M layer 24 may be inserted between the spring 13 and the base of the housing ooooo

Claims (12)

1. A device suitable for cleaning a head of a video cassette recorder, the device comprising a cassette housing having at least one spool therein, and a length of cleaning tape at least partially wound on the spool, characterised in that the spool is spring-loaded to impart tension to the tape while permitting the tape to be at least partially extracted from the housing during its operation.

2. A device as claimed in claim 1, wherein the spool is spring- loaded by means of a resiliently flexible member.

3. A device as claimed in claim 2, wherein the resiliently flexible member is a spiral spring located within a hub of the spool.

4. A device as claimed in claim 3, wherein the spiral spring maintains a generally constant tension on the tape during its operational extraction from the housing. S 15

5. A device as claimed in any preceding claim, wherein the cleaning tape is made of chamois leather.

6. A device as claimed in any preceding claim, wherein the cleaning tape has one end portion wound on the spool, and its opposite end fixed to the housing. 20

7. A video head cleaning cassette having a housing at least one spool located in the housing a length of cleaning tape partially wound on the spool, such that when the tape is pulled from the housing during 25 use, the spool rotates in one direction as the tape is unwound therefrom, and means for biasing the spool in the opposite direction.

8. A cleaning cassette as claimed in claim 7, wherein the biasing means is a spring.

9. A cleaning cassette as claimed in claim 7 or 8, wherein the spool has a hub, and the biasing means is a spiral spring located in the hub.

A cleaning cassette as claimed in any one of claims 7 to 9, 9 wherein the biasing means automatically rewinds the spool and retracts the cleaning tape to the housing when it is released.

11. A cleaning cassette as claimed in any one of claims 7 to wherein an end portion of the cleaning tape is wound around the spool, and the other end of the cleaning tape is fixed to the housing.

12. A video head cleaning cassette substantially as hereinbefore described with reference to the accompanying drawings. DATED this fourth day of May 2001 OLBERTZ HOLDINGS PTY LTD By their Patent Attorneys Cullen Co.