GB2098783A - Adjustable set down position for tone arm - Google Patents

Abstract

A disc record player includes means for causing a transducer (T) carried by a tone arm (18) to be brought to a desired lateral position relative to a record supported on a turntable of the record player and, cue means to lower the transducer (T) relative to the record at the desired position. The record player also includes a deck plate (10), on which the turntable and tone arm are mounted, and a positioning means to cause said tone arm (18) to be brought to a desired lateral position relative to a record supported on the turntable, wherein said positioning means is manually adjustable to permit of the lateral position to which the tone arm (18) is brought by the positioning means being infinitely adjustable over a range of positions. <IMAGE>

Description

SPECIFICATION Improvements relating to record players Description of Invention This invention relates to a disc record player, hereinafter referred to as of the kind specified, having means for causing a transducer carried by a tone arm of the record player to be brought to a desired lateral position relative to a record supported on a turntable of the record player and preferably, means to lower the transducer relative to the record at the desired position. These means are normally termed "positioning" and "cueing" respectively and will be so referred to hereinafter.

Hitherto the desired lateral position at which the transducer is positioned for cueing has been preset, either to a single position such as above the lead in groove of a disc record, or to a selectable one of a plurality of preset positions such as above the lead in groove of a 12" or a 7" disc record.

The provision of such preset lateral positions requires the preset positions to be adjusted during manufacture of the record player and this involves an additional step in the manufacturing process.

It is accordingly an object of the present invention to provide a new and improved disc record player having a positioning means whereby the above mentioned adjustment step is avoided and, in addition, a user is provided with a facility to enable him to choose the location at which the transducer is positioned for cueing.

According to the present invention, we provide a disc record player of the kind specified including a deck plate, on which the turntable is mounted for rotation, the tone arm being mounted on the deck plate for rotation about a positioning axis which extends normal to the deck plate, to permit of positioning of a transducer carried by the tone arm, and to permit of the transducer tracking a record on the turntable, the tone arm also being mounted for rotation about a cueing axis normal to said positioning axis to permit of cueing of the transducer and lifting of the transducer out of contact with the record after playing, and a positioning means to cause said tone arm to be brought to a desired lateral position relative to a record supported on the turntable, wherein said positioning means is manually adjustable to permit of the lateral position to which the tone arm is brought by the positioning means being infinitely adjustable over a range of positions.

The positioning means may comprise an abutment which moves with the tone arm as it rotates about the positioning axis, a positioning member adapted to engage the abutment to arrest rotation of the tone arm at a desired lateral position, and means for adjusting the position of the positioning member so as to permit the desired lateral position to be adjusted infinitely over a range of positions.

The positioning member may be movable to a desired position by manual movement of the tone arm to the desired position, thereby moving the abutment member to the corresponding position, and engaging the positioning member with the abutment member in said position. Preferably, means are provided to retain the positioning member in said position, and further means may be provided to move the positioning member into said position for engagement by the abutment member to arrest movement of the tone arm during positioning.

The positioning member may be retained in said position by a friction clutch, such clutch being releasable to permit of positioning of the positioning member by engagement with the abutment member as the tone arm is moved manually to the desired lateral position, and said clutch being engageable to retain the positioning member in position.

Means may be provided to move the positioning member out of the path of movement of the abutment member during playing of a record and into the path of movement of the abutment member during positioning.

The positioning member may be mounted for sliding movement relative to a positioning lever for setting.

The positioning lever may be mounted for pivotal movement to permit of said lever being moved out of the path of the abutment member after positioning and during playing of a record.

Drive means may be provided to drive the tone arm inwardly to be positioned and, preferably, outwardly after playing of a record.

Drive means may be provided to drive a cueing means whereby the transducer is lowered into playing contact with a record on the turntable when positioned and, preferably, to lift the transducer out of playing contact with the record after playing also.

One example of a record player embodying the invention will now be described in more detail, with reference to the accompanying drawings wherein: Figure 1 is an underneath exploded perspective view of part of the mechanism of a record player embodying the invention; Figure 2 is a plan view of a record player embodying the invention; Figure 3 is an underneath plan view of the record player of Figs. 1 and 2; and Figure 4 is an underneath plan view to an enlarged scale of the off/manual/auto switch of the record player of Figs. 1 to 3.

GENERAL ARRANGEMENT Referring to the drawings, a record player comprises a deck plate 10 upon which a turntable 11 is rotatably mounted about a vertical axis 12 and driven by means of an electric motor 13. A centre spindle 14 is provided at the centre of the turntable 11 and guides a record in conventional manner.

The deck plate 10 is provided with a manually operable speed control 15 and a manually operable off/manual/auto switch 16 and a manually operable cueing position selector control lever 17. A tone arm 18 is pivotally mounted on the upper end of a vertical spindle 19 for up and down movement about a horizontal, cueing axis and the vertical spindle 19 is mounted on the deck plate for movement about a vertical, positioning, axis to allow swinging movement of the pick-up arm 18 transversely relative to a record carried ont he turntable 11.

The turntable 11 has a pinion 21 provided thereon surrounding the centre spindle 15 which is adapted to engage with gear teeth 22 provided on a cam gear 23 which has a generally heart-shaped cam 24 provided in the underside thereof. The cam gear 23 has a conventional tap-tap mechanism 25 provided thereon so that one rotation of the cam gear 23 is caused to take place at the end of playing of each record.

Referring now particularly to Fig. 1, the vertical spindle 19 is journalled in bearings carried on a sub-plate 30 and, at its lower end, has a conical end part 31 which engages a leaf spring 32 mounted on a boss 33 of the sub-plate 30. The leaf spring 32 is provided whereby the spindle may freely rotate in the bearings without vertical play.

Fixed to the lower end of the vertical spindle 19 is a positioning plate 34 which has an arm 35 having an upturned lug 36 at one end adapted to engage a lug 37 provided on the sub-plate 30, and thus to limit outward movement of the tone arm as a result of engagement between the lugs 36 and 37. The tone arm is provided with a conventional anti-skate device 38.

Mounted between the sub-plate 30 and the deck plate 10 is a switch-on lever 39 movable by a link 40 connected to a link 41, extending to the manually operable switch 16, at an electrical "on/off" switch 42.

Movement of the switch 16 from the "off" position 0 to the "manual" position M causes movement of the lever 39 from the position shown in Fig. 1 to the right where it is maintained as a result of engagement of an upturned end 43 with an abutment 44 on the sub-plate 30 where it is held by a coil compression spring 45 in an "on" position which maintains the electric switch 42 on. However, on movement to the "auto" position A, further movement of the switch-on lever 39 to the right occurs to cause a limb 46 thereof to engage a toggle member 47 to cause it to pivot about an axis 48 to cause its lower end to engage a wire 49 carried on a longitudinally slidable tap-tap operating member 50 so as to cause the member 50 to move to the left, in Figs. 1 and 3, so that its left-hand end engages the tap-tap mechanism 25 to initiate rotation of the gear 23.

TONE ARM DRIVE Engaged with the cam track 24 is a roller 51 carried by an oscillating member 52 which is mounted for sliding movement relative to the deck plate by virtue of engagement of a pin 53 on which the roller 51 is carried in a slot 54 of the deck plate, and engagement of a shouldered washer 55 in a slot 56 of the oscillating member, the washer 55 being secured by a screw 57 to a boss 58 of the subplate 30.

A coil compression spring 59 extends between a tag 60 secured to the boss 58 by the screw 57 and an aperture 61 in the oscillating member 52 to normally bias it to the right in Fig. 1.

The oscillating member 52 carries a toothed wheel 62 which is rotatably mounted on the member 52 with a frictional restraint to rotation provided by a circlip applying a radially inwardly directed pressure to a longitudinally slotted shank secured to the wheel so as to force it into frictional engagement with a pin upon which the wheel is mounted.

Thus, as the cam gear 23 is rotated anticlockwise, as viewed in Fig. 2, the oscillating member 52 is first caused to move to the left in Fig. 1 so that the toothed wheel 62 engages a drive pin 63 fixed on the positioning plate 34 and tends to move the tone arm outwardly. However, at the start of playing, the tone arm will be in its outermost position and hence further outward movement will be prevented both as a result of engagement of the end of the tone arm with its rest and as a result of engagement of the lugs 36 and 37.

Thus the toothed wheel 62 will be caused to rotate against its frictional restraint to permit the continued movement to the left of the oscillating member.

As the gear 23 continues to rotate, the member 52 is moved to the right in Fig. 1, the drive pin 63 is engaged by a tooth of the wheel 62 and thus the tone arm is caused to be moved inwardly towards the centre of the turntable. The position at which the inward movement is stopped for cueing of the transducer carried by the tone arm, and how this can be adjusted to any position between predetermined inner and outer positions, will be described hereinafter.

The oscillating member 52 has a raised portion 64 adapted to engage the lower end 65 of a cueing shaft 66 slidably mounted in a downwardly depending portion 67 which extends through an opening (not shown) in the deck plate 10 from a plinth 68 on the upper surface thereof.

As best shown in Fig. 2, mounted on the plinth is a cueing member 69 which is con nected to the shaft 66 and is caused to be raised and lowered with the shaft. A fluid damping device is provided within the member 69 to damp the cueing movement of the tone arm.

Thus, in use, as the oscillating member 52 is moved to the left from its rest position, the lower end 65 engages the raised portion 64 to lift the tone arm from the rest and maintain it raised whilst it is moved inwardly to be positioned at the cueing position. As the oscillating member 52 is moved to the right back to its rest position, the lower end 65 of shaft 66 slides from the raised portion 64 and the tone arm is lowered to bring a transducer on the rone arm, indicated at T, into playing contact with the record.

At the end of playing a record, movement of the oscillating member 52 to the left causes engagement of the lower end 65 with the raised portion 64 to lift the tone arm to maintain it raised whilst the tone arm 18 is pivoted outwardly to lower the tone arm 18 onto rest R as the oscillating member 52 returns to its at-rest position.

SWITCH OFF MEANS On initiation of a cycle of operation, when the oscillating member 52 starts to move to the left, it causes an operating member 71, mounted for rotation on a shaft 72 fixed to the sub-plate 30, to pivot clockwise due to the connection between the operating member 71 and the oscillating member 52 provided by a coil tension spring 73.

This clockwise rotation causes an abutment surface 74 of the operating member 71 to move out of engagement with a lug 75 on a switch member 76, thereby permitting the member 76 to move to the left under the influence of a spring (not shown). The switch member 76 is maintained in this position by engagement with an abutment (not shown) during continued clockwise rotation of the operating member 71.

When the oscillating member 52 returns to the right, an upstanding lug 78 of the oscillating member 52 engages an arm 79 of the operating member 71 and causes it to pivot anti-clockwise to its initial position. As it does so, a step 74a engages the lug 75 and lifts the switch member 76 out of engagement with the abutment (not shown) hereinbefore mentioned, so that switch member 76 is urged by the spring (not shown) against a second abutment surface 74b.

The switch member 76 is maintained in this position during playing of a record. At the end of playing of the record, the tap-tap mechanism causes further rotation of the gear 23 and the mechanism is caused to perform another cycle and, this time, on movement of the oscillating member 52 to the left, the operating member 71 is against caused to pivot clockwise to move the second abutment surface 74a out of engagement with the lug 75 thus permitting the switch member 76 to move further to the left so as to overlie a further abutment surface 74c. On return movement of the oscillating member 52 and hence of the operating member 71 the lug 75 is moved to engage an abutment surface 80 of the switch-on lever 39 and thus cause the upturned end 43 to be lifted out of engagement with the abutment 44 to cause switchoff of the record player under the influence of the spring 45.

If the record player is operated only on "manual", then the limited movement of the switch-on lever 39 causes the lug 75 to be engaged only with the second abutment surface 74b so that, although there is no initial cycle of the gear, the lug 75 is positioned so that switch-off is caused to occur as described hereinbefore when the gear 23 is rotated at the end of playing a record.

The switch member 76 is providrd with a second lug 81 which serves to maintain the tone arm above its rest at the end of playing a record whilst the oscillating member 52 moves to the right to return to its initial position.

More particularly, during a switch-on cycle, the second lug 81 is maintained out of position for engagement with the lug 36 on the positioning plate 34 by virtue of engagement with the above mentioned abutment.

However, during a switch-off cycle of operations, after the tone arm has been moved outwardly so that the lugs 36 and 37 engage, the clockwise movement of the operating member 71 permits movement of the switch member 76 downwardly into position to prevent movement of the lug 36 and hence of the tone arm in the direction away from the rest when the toothed wheel 62 engages the driving pin 63 as the oscillating member returns to its position. After the toothed wheel and pin have become disengaged, the first lug 75 is engaged by the further abutment surface 74c to raise the switch member to switch-off as described hereinbefore, and at the same time to move the lug 81 out of the path of movement of the lug 36.

The operating member 71 carries a spring finger 82 which can engage a cam part 83 on the oscillating member 52. As the oscillating member 52 initiates its movement to the left, the spring finger 82 engages a part 83a of the cam surface 83 and hence the operating member is maintained in its initial position and thus the switch member 76 is maintained in its initial position and hence the second lug 81 is maintained out of the path of movement of the lug 36 as the tone is returned to its rest position. After the tone arm has been returned ,to its rest position, the spring finger engages a part 83b of the cam surface thus permitting the operating member 71 to pivot clockwise and thus to permit the lug 81 to move into position for engagement with the lug 36 to prevent movement of the tone arm of its rest position as described hereinbefore.

POSITIONING MEANS The positioning means comprises a positioning lever 90 mounted for pivotal movement on the shaft 72. The positioning lever 90 carries a positioning member in the form of a finger 91 which is rectilinearly slidably mounted on the lever 90 so that its end abutment surface 92, which is adapted to engage a downwardly depending peg 93 on the positioning plate 34, which provides an abutment which moves with the tone arm, can be located at any desired distance relative to the axis of pivot of the lever 90 between predetermined limits of the extent of movement of the positioning finger 91.

It is to be particularly noted that the position of the finger 91 is infinitely adjustable between the extremes.

A coil compression spring 94 is engaged between lugs 95, 96 provided respectively on the finger 91 and lever 90 respectively so that the finger 91 is normally biased outwardly away from the end surface 92a of the lever 90.

A friction clutch indicated generally at 97 is provided between the finger 91 and lever 90.

The friction clutch comprises a friction pad 98 of any suitable material such as sorbo rubber carried on a plate 99 which is apertured and through which a stirrup-shaped part 100 pressed upwardly from the lever 90 extends to mount the plate 99 for sliding movement towards and away from the plate 90 so that the friction pad 98 can act upon a slotted part 101 of the finger 91, the stirrup 100 being received within the slot 102 to guide the finger for sliding movement in conjunction with a guide part (not shown) at the end 93 of the lever 90. A coil compression spring (not shown) is engaged between the lever 90 and plate 99 to normally urge it away from the lever 90.

A cam lever 103 having a cam surface 104 is slidably mounted within the stirrup member 100 and an aperture 105 formed in an upturned part 106 of the lever 90, as well as extending through an apertured upturned part (not shown) of the plate 99.

The cam surface 104 has three parts, namely a shallowest part where no pressure is applied to the finger 91, a highest part where maximum pressure is applied to the finger 91 as a result of engagement between the highest part of the cam surface and the top surface of the stirrup 100, and an inclined, intermediate, portion where a lesser and adjustable pressure is applied to the finger for setting purposes. The highest pressure is applied, to lock the finger 91 to the lever 90 for positioning operations.

The cam lever 103 is connected by a link 107 to the manual positioning control 17, and when the control is in a "release" position R, the cam lever is moved to engage said lowest cam portion beneath the stirrup to apply no pressure so that the finger 91 is free to slide relative to the lever 90, a "set" position S where the intermediate portion is engaged to apply a light frictional resistance to movement of the finger 91 for setting purposes and a "lock" position L where the maximum pressure is applied to lock the finger 91 to the lever 90 for setting.

In use, assuming that the finger 91 has been set in a desired position relative to the lever 90, as hereinafter to be described, positioning occurs as follows: On initial rotation of the cam gear 23, the oscillating member 52 moves to the left and as the lug 78 moves from the operating member 71, it moves a small distance sufficient to permit the lug 75 to become disengaged from the abutment surface 74a as described hereinbefore. Further movement of the operating member 71 is prevented by engagement of the spring finger 82 with the cam surface 83a. Further movement of the oscillating member 52 causes the spring finger to become engaged with the cam surface 83b so permitting inward movement of the operating member 71. The positioning lever 90 is moved inwardly by a spring attached to an oscillating member 52 adjacent lug 78 which engages the lever 90.It is to be noted that an aperture 109 is provided in the lever 90 to permit of passage of the spring finger 82 for engagement with the cam surface 83 on the oscillating member 52.

This inward movement of the positioning lever causes the abutment surface 92 thereof to be positioned in the path of movement of the peg 93 so that when the tone arm is moved inwardly by engagement between the toothed wheel 62 and driving pin 63, this movement is arrested when the peg 93 engages the end surface 92 so that the tone arm is then positioned into a desired position for cueing.

Cueing then occurs as described and immediately prior to the stylus of the transducer engaging the record, the lug 78 engages the operating member 71 and causes it to pivot anit-clockwise causing the positioning lever 90 to be also moved anit-clockwise as a result of engagement by spring 121 via link 167 and hence the surface 92 of the finger 91 is moved out of the path of movement of the peg 93, so that tracking of a record groove can occur.

At the end of playing a record as mentioned hereinbefore, the operating member 71 and hence the positioning lever 90 is maintained out of the path of movement of the lug 36 and of the peg until the tone arm is at its "at rest' position. The operating member 71 and positioning lever are then permitted to move further clockwise but of course, during this cycle of operations, the positioning lever serves no function and is merely moved out of the path of movement of the peg 93 at the end of the cycle as described hereinbefore.

During manual operation of the record player, no initial cycle occurs and so the surface 92 of the finger 91 is maintained out of the path of movement of the peg 93 and the switch off cycle operates as described hereinbefore and again the positioning lever takes no part.

POSITIONING MEANS SETTING The way in which the desired position of cueing is set will now be described.

The operator sets the control 17 to the "release" position R. This has the two-fold effect of moving the cam lever 103 to release the pressure of the pressure pad 98 on the finger 91 so that the link 167 is pushed inwardly to cause the shallowest part of the cam surface 104 to be beneath the stirrup to release the friction clutch to permit the finger 91 to move to the right under the influence of the spring 94. When the control is moved to the "set" position S, the link 167 is moved to engage the intermediate portion beneath the stirrup to apply a relatively light pressure and at the same time to cause pivotal movement of the positioning lever in a clockwise direction to position the surface 92 in the path of movement of the peg 93.

The operator then moves the tone arm manually to the position where he desires to achieve set down and this causes the finger 91 to be slid to the left in Fig. 1 against the relatively light resistance of the friction clutch at its intermediate setting, so that the finger is positioned with the surface 92 at the location corresponding to the desired position of the transducer. The operator then moves the con trol 17 to the lock position L which moves the link 167 further outwardly to move the locking portion of the cam surface into position with the stirrup to apply maximum pressure to lock finger in the thus set position.After such locking, the link 167 is moved inwardly to cause pivotal movement of the positioning lever in an anticlockwise direction to move the surface 92 out of the path of movement of the peg 93 to return the positioning lever to its normal position and thus permitting manual operation if desired.

If it is then desired to operate the record player automatically, the operator returns the tone arm to the rest and moves the manual control 16 to the "auto" position A to cause rotation of the cam gear 23 and cycling as described hereinbefore. As the peg 93 engages the end surface 92 it arrests movement of the tone arm at the desired position for cueing of the transducer.

The way in which the manual control achieves the above described movements of the link 167 will now be described.

Referring particularly to Fig. 4. The manual control comprises a lever 120 to which one end of the link 167 connected and a coil tension spring is also connected to the end of the lever 120 and to the deck plate as indicated at 121. The lever 120 has an undulating cam slot 122 and is pivoted as indicated at 123. The manual lever 124 is mounted for sliding movement by means of pins 125, 126 engaged in slots 127, 128 respectively in the deck plate and a coil tension spring 129 normally biases the lever to the right.

When the lever 124 is in the "release" position it is at one extreme, left-hand, end of the cam slot which causes clockwise movement of the lever 120 thus causing the link 167 to push the cam lever 103 to the release position, and also cause anti-clockwise movement of the positioning lever. As the manual lever 124 is released, it is moved by the bias of the spring 129 to the set position where it engages an intermediate, inclined, ##.rt of the cam slot which causes clockwise movement of the lever 120 and hence causes the link 167 to pull the cam lever 103 to its intermediate position and cause clockwise movement of the positioning lever to locate it so that the finger 91 is in the path of movement of the peg 93.

The angle of the cam slot 122 is such that the bias of the spring 129 does not cause the manual lever 124 to move further and so the apparatus remains stable in the "set" position.

Where it is desired to lock the positioning finger relative to the positioning lever, the manual lever 124 is moved further to the right and this causes, initially, movement of the lever 1 20 anti-clockwise to pull the cam lever 103 to its locked position and then the pin 126 moves to the other extreme end of the cam slot 122 where the lever 120 is permitted to pivot clockwise to cause the link 167 to pivot the positioning lever anti clockwise, so moving the finger 91 out of the path of movement of the peg 93 as described hereinbefore.

Claims (15)

1. A disc record player of the kind specified including a deck plate, on which the turntable is mounted for rotation, the tone arm being mounted on the deck plate for rotation about a positioning axis which extends normal to the deck plate, to permit of positioning of a transducer carried by the tone arm, and to permit of the transducer tracking a record on the turntable, the tone arm also being mounted for rotation about a cueing axis normal to said positioning axis to permit of cueing of transducer and lifting of the transducer out of contact with the record after playing, and a positioning means to cause said tone arm to be brought to a desired lateral position relative to a record supported on the turntable, wherein said positioning means is manually adjustable to permit of the lateral position to which the tone arm is brought by the positioning means being infinitely adjustable over a range of positions.

2. A record player according to Claim 1 wherein the positioning means comprises an abutment which moves with the tone arm as it rotates about the positioning axis, a positioning member adapted to engage the abutment to arrest rotation of the tone arm at a desired lateral position, and means for adjusting the position of the positioning member so as to permit the desired lateral position to be adjusted infinitely over a range of positions.

3. A record player according to Claim 2 wherein the positioning member is movable to a desired position by manual movement of the tone arm to the desired position, thereby moving the abutment member to the corresponding position, and engaging the positioning member with the abutment member is said position.

4. A record player according to Claim 3 wherein means are provided to retain the positioning member in said position.

5. A record player according to Claim 3 or Claim 4 wherein means are provided to move to positioning member into said position for engagement by the abutment member to arrest movement of the tone arm, during positioning.

6. A record player according to any one of Claims 3 to 5 wherein the positioning member is retained in said position by a friction clutch, such clutch being releasable to permit of positioning of the positioning member by engagement with the abutment member as the tone arm is moved manually to the desired lateral position, and said clutch being engageable to retain the positioning member in said position.

7. A record player according to any one of Claims 3 to 6 wherein means are provided to move the positioning member out of the path of movement of the abutment member during playing of a record and into the path of movement of the abutment member during positioning.

8. A record player according to any one of claims 3 to 7 wherein the positioning member is mounted for sliding movement relative to a positioning lever for setting.

9. A record player according to Claim 8 wherein the positioning lever is mounted for pivotal movement to permit of said lever being moved out of the path of the abutment member after positioning and during playing of a record.

10. A record player according to any one of the preceding claims wherein drive means are provided to drive the tone arm inwardly to be positioned.

11. A record player according to any one of the preceding claims wherein drive means are provided to drive the tone arm outwardly after playing of a record.

12. A record player according to any one of the preceding claims wherein drive means are provided to drive a cueing means whereby the transducer is lowered into playing contact with a record on the turntable when positioned.

13. A record player according to any one of the preceding claims wherein drive means are provided to drive a cueing means whereby the transducer is lifted out of playing contact with the record after playing.

14. A disc record player substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

15. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.