IMPROVED CONTINUOUS LOOP TAPE CASSETTE

Abstract: A continuous loop cassette (10) includes a reel (12) within a casing (11) from which tape (13) is unwound, being twisted so as to emerge from the centre of the reel, and then untwisted by projections (21) and (22). By providing openings (14), (15) in different edges of the casing for engagement with tape head and capstan of reproducing equipment, a very compact overall size can be achieved.

Description: IMPROVED CONTINUOUS LOOP TAPE CASSETTE The present invention relates to continuous loop tape cassettes, particularly but not exclusively for use in data storage applications. Tape cassetts ofthis type, such as that described in U.S. Patent No. 4,013,239, form particularly convenient storage means for serially input and output data, for example programs usable in microcomputers. Continuous loop cassettes avoid the need to find the correct starting place on a tape for the specific program; it is sufficient to run the tape and await the recognition of the program name or code as identified by the "load" instruction or similar. Disadvantages with previously proposed continuous loop cassettes include difficulties with running at sufficient speeds so as to allow fast data transfer and also that the size of the proposed cassettes has necessitated bulky record/replay equipment. The present invention provides a configuration of tape cassette which overcomes or reduces these dis- advantageous effects. Specifically, it is arranged that the record/replay head of the reproduction equipment engages the tape along a different side of the cassette than that along which the capstan or other drive means for tape transporting engages the tape. Features and advantages of the present invention will become apparent from the following description of a preferred embodiment thereof, given by way of example OMPI K Λ> WIPO ' when read in conjunction with the accompanying drawing, in which:- Figure 1 shows a partially sectional view of the preferred cassette so as to illustrate one half of the casing, with important features of the other half shown in broken lines; and Figure 2 is a plan view of the cassette shown in Figure 1, illustrating one side of the casing. Referring to Figure 1, a continuous loop tape cassette mechanism is shown wherein the record/replay head of associated apparatus and the drive capstan are arranged to engage the tape along adjacent sides of the casing, as opposed to the previously proposed arrangements in which both tape engaging functions are performed along the same side. The cassette 10 includes a lower casing half 11 including provision for receiving a reel 12 of tape 13* Two openings 14, 15 are provided in different sides of the cassette, one opening 14 being for engagement of the tape 13 by a recording/reproducing head (not shown) of suitable equipement, and the other opening 15 for engagement of the tape 13 by a capstan (not shown) so as to drive the tape. The opening 14 includes a pressure pad 16 held by a resilient member 17 against which the head is to press, and the opening 15 has aligned therewith a roller 18 which is arranged for the capstan to press against, so as to act as a pinch roller. The pinch roller lS is positioned for rotation in one corner of the cassette 10 and a further roller 19 is positioned to rotate as an idler in the corner on the opposite side of the opening 14. The tape 13 is threaded from the reel 12 via idler roller 19, past the pressure pad 16, via pinch roller 18 and back to the reel 12. An abutment 20 helps preserve tape tension, and abutments 21,22 serve to untwist the tape (which has been twisted through 90° as explained O nMsPIT below) for proper alignment with idler roller 19 * The tape 13 from the centre of the reel 12 is fed out and twisted through 90° to emerge from the centre in a plane parallel to the major surfaces of the cassette 10. A suitably profiled and recessed surface, shown by dotted line 23, is provided in the upper casing half, and this allows the twisted portion of the tape to adequately clear the reel 12 without excessive contact which would lead to the reel jamming and possibly the tape breaking. Lugs 24 are provided on the outside surfaces of the cassette 10 and may be used to assist retention of the cassette by the tape transport mechanism. In operation, the cassette is inserted into the tape transport/reproducer equipment. # The preferred insertion direction is towards the right as illustrated in Figure 1, i.e. so that the pressure pad 16 (and tape in front of the pad) is pushed towards and ultimately in contact with a suitably disposed tape head in the equipment. At the same time, a capstan or other drive arrangement is brought into engagement from a sidewards direction with the pinch roller 18, so as to sandwich the tape in between. The capstan may either be mounted on a spring-biassed arrangement to provide the force against the pinch roller 18 upon insertion of the cassette, or alternatively a mechanical system could be provided which would direct the capstan appropriately after insertion of the cassette. When the cassette has been pushed far enough for proper engagement with head and capstan, the lugs 24 may engage with suitable retaining means in the equipment. When the drive capstan is rotated, tape 13 is drawn in an anticlockwise direction from the reel 12, via the untwisting abutments 21,22,idler roller 19, past the head and pressure pad 16, by the rotation of pinch roller 18 resulting.from rotation of the contacting capstan. Transported tape is then drawn on to reel 12 by rotation of the reel, after passing abutment 20. If preferred, the insertion direction of the cassette could be changed, by the provision of suitable reproducing equipment, so that the pinch roller 18 would be brought towards the capstan, whereupon the head would be inserted from the side. However, the previously-described arrangement is believed preferable, since alignment with the head is more readily achieved. It will be seen that the described embodiment of the invention provides a considerably more compact cassette compared to the previously-proposed arrangements, by virtue of providing engagement facilities for capstan and head on different edges of the cassette. Figure 2 shows a plan view including the upper half 25 of the casing, which is shown as including surface projections 26. A sleeve for containing and storing the cartridge when not in use can be provided with corres- ponding projections (or recesses) so as to inter-engage and retain the cartridge in the sleeve.

Claims: CLAIMS 1. A continuous loop tape cassette comprising a ' casing, a reel of tape within the casing, means for enabling tape to be taken from the centre of the reel and twisted so as to clear the reel, abutments for un- twisting the tape once clear of the reel, an opening in one edge of the casing exposing the tape for engagement with a tape head, and another opening in a different edge of the casing exposing the tape to a drive means for transporting the tape, whereupon the tape is fed back to the outside of the reel. 2. A tape cassette according to claim 1, wherein the first-mentioned opening includes a pressure pad for sandwiching the tape between the pressure pad and the tape head. 3• A tape cassette according to claim 1 or 2, wherein the other opening includes a pinch roller for sandwiching the tape between the pinch roller and a capstan of the drive means. 4« A tape cassette according to claim 1, 2 or 3, wherein the two openings are in adjacent edges of the casing. 5. A tape cassette according to claim 4, wherein the cassette is arranged to be inserted into reproducing equipment in a direction such that the first-mentioned opening moves towards the tape head. 6. A tape cassette according to any preceding claim, wherein the casing is provided with surface pro¬ jections on the exterior for engagement with corres¬ ponding surfaces within a sleeve for storing the cassette..

Inventors: SOUTHWARD DAVID CONNOR, WILLIAMS JOHN VAUGHAN, SOUTHWARD, DAVID, CONNOR, WILLIAMS, JOHN, VAUGHAN
Applicants: SINCLAIR RES LTD, SINCLAIR RESEARCH LIMITED
Application year: 1984
Main classification: G11B23
IPC codes: G11B23