GB2185142A - Cassette tape deck - Google Patents

Abstract

The invention relates to a cassette tape deck in which there is a head slider 17 carrying a pinch roller 19 and play head 18. The slider can be moved forward by an operating lever 24 but will only go forward if a tape is correctly inserted in the tape deck. This is achieved by a resilient arm (21) attached to the slider which carries a locking device 22 and a sensor tip 23. When the tape is correctly inserted it engages tip 23 and presses the locking device 22 downwardly so as to allow the head slider to be moved into the ON position by means of the lever 24. <IMAGE>

Description

SPECIFICATION Cassette tape deck This invention relates to a cassette tape deck and is particularly concerned with a safety system to ensure that the mechanism of the deck is only set in motion if a cassette tape is inserted correctly.

In conventional systems a play key will push the play head against a cassette tape whether or not the cassette tape is inserted into the cassette deck properly. This results in scratching or other damage to the delicate play head when it is forced into contact with the hard edges of a cassette tape casing.

It is also an object of the invention to provide a system in which a single operationaly lever can be used for the on and offfunctions.

In accordance with the present invention there is a tape deck embodying a single lever which controls both start and stop functions ofthetape.

Preferably a slider carries a play and record head and a pinch roller, movement ofthe slider being controlled by said lever so asto move the play and record head and the pinch roller into contact with the tape. Means may be provided to inhibit movement of the slidertowardsthe play/record position until a tape is properly positioned in the deck. Said means may include a resilient arm carrying a sensortip which protrudes into the tape deck so that when a tape is inserted the sensortip is deflected and thus deflects the arm.

The deflection of the arm and sensortip may release a catch which would otherwise hold the slider and prevent movement of it.

From another aspect the invention comprises a tape deck including a slide carrying a record/play head and a pinch roller, movementofthe slide into the play or record position being controlled by a lever, means being provided to inhibit said movement until a tape is correctly positioned in the tape deck. Said means may comprise a resilient member having a sensor tip which protrudes into the tape deck so that when the tape is inserted the sensor tip is deflected thus deflecting the resilient member or arm. The deflection of the arm may release a catch which acts as said means inhibiting movement ofthe slider. There is a tape deckcomprising means operable by insertion of a tape into the deck to switch circuitry in the tape deck to accommodate either a metal cassette tape or a non metallic cassette tape.

Said means comprise an arm movable by the cassette tape and having a projection which, in the case of a metallictape, enters an aperture in the tape and in the case of non metallic tape abuts the tape cassette so that the arm has two positions, one position for metallic tapes and one position for non metallictapes. The movement of the arm may in turn operate a switch and the switch brings in appropriate circuitryforeithera metallic or non metallictape according to which kind of tape is inserted in the cassette.

From another aspect the invention comprises a tape deck with a cam system for auto-stop function ofthe tape, the cam being rotatable by or with the mechanism which causes movement of the tape and being arranged to operate a switch alternately on and off so asto produce, through electronic circuitry, a train of pulses whereby when the tape reaches the end of its travel the pulses cease and the tape is then stopped electronically rather than mechanically.

said switch may be a leaf switch with a pair of contacts one of which is in contact with said cam, which is an oval cam, whereby the leaf switch is alternately opened and closed as the cam rotates.

In the accompanying drawings: Figure 7 is a plan of a cassette tape deck embodying the present invention; Figure2 is a front elevation of the same deck; Figure 3 is an under plan of the deck; Figure 4illustrates a head slider carrying a play head and pinch roll which forms part of the deck; Figure 5shows the head slider incorporated into a portion ofthe deck with the head slider in the off-mode position; Figure 6shows a detail of a locking device; Figure 7a shows the locking device locked; Figure 7b shows the locking device released; Figure 8 shows the slider carrying the head in the play position; Figure 9 is a scrap section partly in elevation showing a tape cassette being inserted into the deck; Figure 10 illustrates a " normal "::cassette tape; Figure 11 shows "metal" cassette tape; Figure 12 is a detail illustrating mechanism for distinguishing between normal a d metal tapes with parts in the position they occupy Where the metal cassette tape is inserted into the cassette deck; Figure 13 shows the same detail but in the position which the parts occupy when the normal cassette is inserted into the tape deck; Figure 14a shows a cam and switch arrangement for switching off the cassette at the end of a tape with the contacts of the switch open; and Figure 14b shows the same device with the switch contacts closed.

The cassette player or cassette tape deck shown in Figures 1 to 3 is in many respects conventional and only the modifications which are the subject of this invention will be described in detail. The cassette player 10 has a deck 11 carrying, as is usual, a motor 12, flywheel 13 and gear 14 which forms part of the conventional gear train for driving the pick-up spindle 15 and tape drive spindle 16. A head slider 17 is slidably mounted on the deck and carries a play head 18 (which may also incorporate the usual record and erase functions) and a pinch roller 19 adapted to trap tape against the tape drive spindle 16 in the operative position, in the conventional manner.

The movement of slider 17 is controlled by a lever 24 pivoted at 25 (Figure 3). One end 26 of lever 24 is connected by a pin 27 and slot 28 mechanism to the head slider 17.

The head slider 17 comprises a cross member 20 and carries a resilient arm 21 atthe free end of which is formed a locking device 22 and a sensortip 23. The purposeofthelocking device is to engage the deck 11 as shown in Figure 7a so as to prevent movement of the slider 17 towards the play position. The purpose of the sensor tip 23 is to project through the deck as shown in Figure 5 for example and to be engaged by a tape cassette 29 which is inserted into the cassette player, the tape cassette itself engaging the sensortip 23 and thus pushing the end of resilient arm 21 downwardly thereby releasing the locking device 22so asto allow movement ofthe head slider.This movement will take place automatically once the tape is inserted because a spring 30 will cause lever 24to pivot about 25 thus moving the pin andslotmechanismandthesliderso that the tape head engagesthetape and the pinch rollertrapsthetapeagainstthetapedrivespindle thus setting the tape automatically into its play (or record or erase according to what has been selected) mode.

To stop the tape at any time lever 24 is pressed (inwardly) and moves slider 17 away from the play position (shown in FigureS) towards the off mode position (shown in Figure 5). As the sensortip projects up through the tape deck it will assist in ejecting the tape. Thus it is also possible with this arrangement to dispense with the normal eject button.

The cassette deck incorporates a mechanical tape sensor to distinguish between normal tapes and metal tapes and set the deckupto operate appropriately according to which type of tape is inserted.

As can be seen by comparing Figure 10which shows a normal tape with Figure 11 which shows a metal tape, the metal tape has distinguishing features in the forum of two rectangular holes 31,32 whereas the normal tape does not have these holes.

In accordance with the feature of the present invention the cassette deck incorporates a cassette detective arm 33 which is slidable in the direction of the arrows shown in Figures 12 and 13 and which carries a projection 34. The projection 34, as shown in Figure 12will engage in one ofthe rectangular holes 31,32 when a metal tape is inserted intothe cassette. As shown in Figure 13, when a normal tape is inserted the end of the tape cassette will abut the projection 34.

The effect of this is illustrated in Figures 12 and 13.

The detective arm 33 carries an operating post35 which engages the central leaf 36 of a leaf switch 37 having two other leaves 38 and 39.

As can be seen from Figures 12, when a metal cassette is inserted the detective arm 33 will not be moved to the right and so the post 35 in contactwith central leaf 30 allows central leaf 30 to remain in contactwith left hand leaf 38. When a normal cassette is used, as shown in Figure 13, the detective arm 33 is moved to the right, post 35 engages central leaf 36 and brings it into contact with leaf 39.

The two different contact positions of the switch can be employed to set up electronic circuitry appropriate to cope with either a normal cassette or a metal cassette. Such circuitry is conventional and is normally operated by a separate manual switch on the exterior of the cassette player.

The position ofthe switch 37 can be seen in Figures 1 and 3 of the drawings.

In accordance with another feature of the invention there is a built in moving cam system for tape end auto-stop function.

A rotatable oval cam 40 (see Figures3, and 14b) is arranged to be rotated by the drive mechanism so that as the pick up reel rotates so the cam rotates.

The cam is in contact with leaves 41 and 42 of a leaf switch 43.

The leaf switch is located so that it is in contact with the surface contourofthe oval cam. During the normal play function the cam will revolve together with the pick up reel assembly. This makes the two contact leaves ofthe spring open and close alternately which will produce a series of pulses.

Whenthetape reaches the end the pickup reel assembly stops and the oval cam will not rotate. The leaf switch will then be either in its on or off position which will stop the train of pulses and thereby produce a stop signal. By connecting the leaf switch to appropriate electrical power supply circuitry an auto stop function can be implemented in accordance with the starting and stopping ofthe pulsed train of signals.

It is a feature ofthis cassette deckthat most of the parts for instance the main body and deck 1 the lever 24, the flywheel 13, the gears 14 etc., the slider 17 and its associated parts, and the detective arm 33 should all be made of plastics material.

Use of plastics material makes for ease in assembly, lightness in weight, and good performance and reliability.

Claims (18)

1. Atape deck embodying a single lever which controls both start and stop functions ofthetape

2. Atapedeckaccordingtoclaym land including aslidercarryinga play and record head and a pinch roller, movement of the slider being controlled by said lever so as to move the play and record head and the pinch roller into contact with the tape.

3. Atape deck according to claim 2 and in which means are provided to inhibit movement of the slider towardstheplay/record position until atapeis properly positioned in the deck.

4. Atape deck according to claim 3 and in which said means includes a resilient arm carrying a sensor tip which protrudes into the tape deck so that when a tape is inserted the sensortip is deflected and thus deflects the arm.

5. Atape deck according to claim 4 and in which deflection of the arm and sensortip releases a catch which would otherwise hold the slider and prevent movement of it.

6. A tape deck including a slide carrying a record/play head and a pinch roller, movementofthe slide into the play or record position being controlled by a lever, means being provided to inhibit said movement until a tape is correctly positioned in the tape deck.

7. Atape deck according to claim 6 and in which said means comprises a resilient member having a sensor tip which protrudes into the tape deck so that when the tape is inserted the sensor tip is deflected thus deflecting the resilient member or arm.

8. Atape deck according to claim 7 and in which deflection of the arm releases a catch which acts as said means inhibiting movement ofthe slider.

9. Atape deck comprising means operable by insertion of a tape into the deck to switch circuitry in the tape deck to accommodate either a metal cassette tape or a non metallic cassette tape.

10. Atape deck according to claim 9 in which said means comprises an arm movable by the cassette tape and having a projection which, in the case of a metallic tape, enters an aperture in the tape and in the case of non metallic tape abuts the tape cassette so that the arm has two positions, one position for metallictapes and one position for non metallic tapes.

11. Atape deck according to claim 10 and in which movement of the arm in turn operates a switch and the switch brings in appropriate circuitry for either a metallic or non metallic tape according to which kind of tape is inserted in the cassette.

12. Atapedeckcomprising acamsystemfor auto-stop function of the tape, the cam being rotatable byorwith the mechanism which causes movement of the tape and being arranged to operate a switch alternately on and off so as to produce, through electronic circuitry, a train of pulses whereby when the tape reaches the end of its travel the pulses cease and the tape is then stopped electronicallyratherthan mechanically.

13. Atape deck according to claim 12 in which said switch is a leaf switch with a pair of contacts one of which is in contact with said cam,which is an oval cam, whereby the leaf switch is alternately opened and closed as the cam rotates.

14. A tape deck in which the majority of the parts are made of plastics material.

15. Atape deck according to claim 13 in which said parts made of plastics material include the main body, the on/off operating lever, gears, flywheel etc.

16. Atapedecksubstantiallyashereinbefore particularly described and as illustrated in Figures 1 to 9 of the accompanying drawings.

17. Atape deck substantially as hereinbefore particularly described and as illustrated in Figures 10 to 12 of the accompanying drawings.

18. Atape deck substantially as hereinbefore described and including the feature shown in Figure 1 4 of the accompanying drawings.