DE1049600B - Device for the optional playback of disc-shaped sound carriers recorded on two sides in jukeboxes - Google Patents

Description

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FEDERAL REPUBLIC OF GERMANY

GERMAN / Jm8k \ PATENT OFFICE

kl. 42 g 20/04

INTERNAT. KL.

EXPLORATION PAPER 1049 600

H28131VIIId / 42g

REGISTRATION DATE: SEPTEMBER 18, 1956

NOTICE

THE REGISTRATION

AND ISSUE OF:

EDITORIAL: JANUARY 29, 1959

The invention relates to a device for selectively playing one or the other side a rotating about a horizontal axis on two sides disc-shaped sound carrier, z. B. Record for a jukebox, consisting of a large number of sound carriers stored in a magazine selectable by means of a selection device and by means of a transport device from a cardanic stored pickup system can be fed to the existing playback device for scanning the selected page is, wherein the pickup system is designed as a preselector so that it is in his the middle position releasing the sound carrier by a depending on the program control mechanism actuated lock is held.

In a known device of this type, the records are in such large intervals in a drum magazine arranged that the tonearm, which is provided with a stylus on both sides, is between the Move records and play the record on the left or right of him as desired. this is achieved by the fact that, depending on the direction of rotation and function of the tonearm control, the plates on the one side or the other. Here the contact pressure of the needle is relatively high. It is also a great electrical and mechanical effort required to ensure that the selected side of the record is scanned.

It is also known in turntables, the tonearm to be applied to the plate by electromagnetic actuation. However, this known device is with afflicted with considerable flaws. To return the tonearm from the end position to the starting position ensure, this must have a considerable weight, resulting in a high needle bearing pressure on the record. Another disadvantage is that the tonearm has a large counterweight must have, since the torque to lift the tonearm from its end position is great is. As a result, the magnetic induction of the magnet must also be large.

The invention is based on the object of addressing the disadvantages inherent in the known devices avoid and create a simple and inexpensive to manufacture preselection system and the system pressure of the Keep the needle as small as possible (about 5 to 7 g).

According to the invention, the tonearm is known to consist of two rigidly connected tonearms, each with a scanning head, which receive the sound carrier in the middle between them; Here, the axis for the application and lifting movements of the tonearm and a leaf spring extending vertically downward from this axis with its broad side are arranged in the plane of the sound carrier, and the leaf spring IO

Device for selective playback

of disc-shaped sound carriers recorded on two sides in jukeboxes

Applicant:

Wilhelm Harting,

Minden, Simeonsglacis 24

Dr Wilhelm Foelkel, Ahle near Bünde (Westphalia),

and Rudolf Krause,

Espelkamp-Mittwald (Kr.Lübbecke, Westf.),
have been named as inventors

20th

carries a soft iron anchor plate at its free end, which is arranged between two actuated by the magazine control solenoids that by optionally exciting a magnet the armature plate under tension of the leaf spring to the left or to the left is movable on the right.

Instead of the soft iron anchor plate, a permanent magnet plate with an axially directed magnetic Polarity be provided; here both electromagnets are at the same time, but with optional reversible current direction excitable, so that the magnetic plate in each case by a pole piece of the electromagnet is attracted to and repelled by the other. The use of a permanent magnet has the Advantage that both magnets are effective to deflect, i.e. a greater force (magnetic induction) is available than with only one effective excitation coil; When playing the selected record, the magnet coils remain de-energized as the magnetic disk adheres automatically.

So you can apply a short control pulse to the electromagnets, which at the same time to Operation of the switch for the magazine drive is required.

An embodiment of the subject matter of the invention is shown in the drawings. 1 shows a side view of the device according to FIG Invention,

Fig. 2 the suspension of the tonearm,
Fig. 3 is a front view according to Fig. 1,
FIG. 4 shows a partial view of the device in the direction of arrow 20 in FIG. 1.

809 747/241

In Fig. 1, a record 1 is rotated by a horizontally mounted bracket, not shown offset, for example in the direction of arrow 2. A tonearm 3 is also groping. his customer head 4 the Record 1 off. The tonearm 3, as is known, is in a cardanic system with axes 5-5 'and 7-7 'supported, namely the axis 5-5' enables the movement of the scanning head in the direction of the double arrow 6 and the axis 7-7 'exerted a movement perpendicular to arrow 22 (Fig. 4), the slide moves against the tensile force of the spring 13 and releases the pin 11 and thus the tone arms 3 and 3 '. To the Following the tension of the pretensioned spring 14, the system 4 of the left tonearm 3 now lies on the surface the disc to be played. An adjusting screw 23 ensures that the tonearm is under Action of the counterweight 9 is erected so far in its starting position that the stylus

For this. The pickup head 4 is located below the tonearm suspension when it is placed in the first groove a counterweight 9 on a lever arm 8. Furthermore, the record is engaged. The preload of the spring

15th

with the tonearm 3, a lever 10 is firmly connected, which carries a pin 11, which in turn with a slide 12 is engaged. This slide is held in an upper stop position by a tension spring 13. There is also a ribbon steel spring 14 and with below the suspension of the tonearm system this is connected to a plate 15 made of a permanent magnetic material. This tile shows an axially directed magnetic polarity, such that, for example, the side visible in FIG represents a north pole.

In Fig. 2, the cardanic suspension system of the tonearm with the axes 5-5 'and 7-7' is shown schematically. In Fig. 3, the record 1 held and guided by two jaws 16 and 17 is shown. It can also be seen that the tonearm 3 shown in Fig. 1 with pick-up head 4 is opposite a second tonearm 3 'with pick-up head 4', which is rigidly connected to the first-mentioned tonearm 3 and is designed approximately in the form of a mirror image of this. This tonearm 3 'enables the right side of the disk of the sound carrier 1 to be scanned, while the tonearm 3 is provided for scanning the left side of the record. Below the suspension of this double-tone arm in the axes 5-5 'and 7-7', the magnetic plate 15 connected to the spring member 14 is visible. Behind it is the lever 10, which is rigidly connected to the tonearm system and which carries the pin 11 (not visible in FIG. 3).

Opposite the magnetic plate 15 are two electromagnets 18 and 19 in the plane of the axis 5-5 ' arranged.

From Fig. 4 it can be seen that the slide 12 has a Has cutout 21, which has approximately the shape of an equilateral © of the isosceles triangle with rounded Has corners .und in .den the pin 11 connected to the tone arm via the lever 10 engages. Through the tension spring 13, the slide 12 is within a lateral guide, not shown, pulled up until the lower rounding of the cutout 21 strikes against pin 11. As a result, the system of the two tonearms 3 and 3 'is shown in FIG. 3 Locked position.

The mode of operation of the device described above is as follows: If the performance (Fig. 3) the left side of the plate 1 desired, the two electromagnets 18 and 19 obtained by corresponding Selection of the current direction of such a magnetic induction, that the Pblschuh facing the permanent platelet 15 represent a south pole. This will -will this plate is attracted by the left magnet 18, while it is repelled by the right magnet 19. The spring member 14 is thus bent over to the left without initially changing the system of the tonearms 3 and 3 ' the axis 7-7 'is rotated, since the blocking of the caused by the cutout 21 of the slide 13 Pin 11 of the .'Hebels 10 is still effective. Is now by 'a program control mechanism (not shown) A pressure on slide 12 in the direction of 14 now determines the contact pressure of the scanning needle. Following the incline of the record grooves, the tonearm system now rotates around the axis 5-5 '. In order to prevent undesired friction of the permanent plate 15 on the end face during this movement of the attracting electromagnet ^ is to be avoided in the practical application of the inventive idea the device designed so that the spring member 14 and the permanent plate 15 of the rotation of the tonearm system do not follow around the axis 5-5 '.

After reaching the run-out groove of the record, the deflected tonearm system 3, 3 ', 8 and 10 a switching contact is reached, which initiates the process of further program control, i.e. the pressure on the slide 12 cancels in the direction of arrow 22, the slide thus the action of the tension spring 13 suspending. Through the recess 21, the pin 11 and thus the system of the tonearms is back in the brought in the middle position shown in FIG. Under the action of gravity, effective on the counterweight 9, the tonearm system stands up again to its starting or rest position at the stop 23 to reach again.

The invention thus also enables the automatic "retrieval" of the tonearm after the end of the Playback process enables. In the known designs, however, the tonearm is guided mechanically.

Claims (6)

Patent claims: 1. Device for-1 choice have playing one or the other side of a disk-shaped sound carrier that rotates about a horizontal axis and is recorded on two sides, e.g. B. Record for a jukebox, which can be selected from a large number of sound carriers stored in a magazine by means of a selection device and can be fed to the playback device consisting of a cardanic! that it is held in its central position releasing the sound carrier by a lock actuated iia as a function of the program control mechanism, characterized in that the tonearm is known to consist of two tonearms (3, 3 'which are rigidly connected to one another and which receive the sound carrier in the middle between them) ) each with a scanning head (4,4 ') and the axis (7, 7') for the application and lifting movement of the tonearm and one from this axis; (7, '.7'); with its broad side perpendicular to leaf spring s (14) extending below are arranged in the plane of the sound carrier (1) and the At its free end leaf spring carries a soft iron Ariker plate (15) which is arranged between: two electromagnets (18, 19) actuated by the magazine control in such a way that by optionally exciting a magnet 25th 30th 35 4 ° 45 55 ⁶ ° 65 the anchor plate (15) moves to the left or to the right under tension of the leaf spring (14) will. 2. Apparatus according to claim 1, characterized in that a permanent magnet plate (15) is provided with axially directed magnetic polarity and that both electromagnets (18, 19) can be excited simultaneously, optionally in the opposite direction of current. 3. Apparatus according to claim 1 or 2, characterized in that the tonearm lock one from the cardan bearing downwardly extending arm (10) with one at its free Having arranged at the end, perpendicular to the axis of rotation of the sound carrier extending locking pin (11), which in a recess (21) of a vertically guided, by a tension spring (13) after engages pulled up slide (12), and this recess (21) is formed so that a lateral Avoidance of the locking pin (11) in the upper position of the slide (12) prevented in the lower position is possible. 4. Apparatus according to claim 3, characterized in that the recess (21) has the shape an equilateral or isosceles triangle with rounded tips placed on its tip Has. 5. Device according to one of claims 1 to 4, characterized in that the pickup system by an attached counterweight (9) or a spring around the parallel to Axis of rotation of the sound carrier (1) lying cardan axis (5-5 ') in the determined by a stop (23) Rest position can be swiveled back. 6. Apparatus according to claim 5, characterized in that the the rest position of the pickup system defining stop (23) is adjustable. Considered publications:
British Patent No. 636,971;
U.S. Patent No. 2,175,142;
German utility model No. 1703 312;
Belgian patent specification No. 504 654. 1 sheet of drawings © 809747/241 1.59