JPS5916975Y2 - Side force canceling device in a joke box player - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device for canceling side force of a pickup arm in a vertical jukebox player.

In a vertical jukebox player, as shown in FIG. 1, when the record is held vertically and rotated, and the left side of the record is played,
The pickup arm A rotates from the left side (the front side with respect to the paper surface in the figure) and moves the record stylus C provided on the right side of the pickup cartridge B attached to it to the left side Da of the record disc with a predetermined stylus pressure. The record is brought into contact and rotated toward the center of the record according to the performance.

Also, when playing the right side of the record disc, the pickup arm A rotates from the right side (the side away from the page in the figure), and the pickup force equals the record needle C' provided on the left side of the tray B. Play by placing it in contact with the right side of the record.

Therefore, when playing the right or left side of a record,
The records will be driven forward and backward, respectively.

When the record is driven in the forward direction, that is, in the direction of rotation of the record, or in the direction of pulling the pickup arm in its longitudinal direction, an inside force is applied to the record stylus of the pickup cartridge, and the direction of rotation of the record is reversed, that is, when the record is driven in the direction of pulling the pickup arm in its longitudinal direction. When the pickup arm is driven in a direction that pushes it in its longitudinal direction, an outside force is applied, and when the record rotates forward or backward, a side force in the opposite direction is applied.

Further, referring to FIG. 1, the effective length of the pickup arm A is set so that the horizontal tracking angle θ always satisfies θ≧0 in normal rotation.

In other words, the inside force F is F−μwtanθ≧
0 (however, the coefficient of friction between the μN record stylus and the record disc, W: stylus pressure, or the moment applied to the pickup arm A)-M is set so that M-μWS111θ, L≧0.

If μ, M and T are positive in the direction shown in Figure 1,
In reverse rotation, μ is negative, so the side force and the moment l-M applied to pickup arm A are negative, and a force acts on pickup arm A in the opposite direction to that in normal rotation.

This side force prevents the record stylus of the pickup cartridge from accurately tracing the grooves on the record, and in severe cases may even cause the stylus to fly.

Conventionally, in this type of jukebox player,
Ignoring this side force, I simply balanced the pickup arm with no record attached (no side force).

In order to cancel out such side force, this idea uses a weight to load the pickup arm with a force equal to the inside force, but in the opposite direction, to subtract the inside force Z when the record is played in normal rotation. Set to zero.

In addition, when playing a record with reverse drive, in order to cancel the outside force, an inside force equal to the resultant force of the outside force and the above-mentioned current eight, but in the opposite direction, is applied to the lever pulled with a predetermined force by a spring. Press it against the pickup arm to subtract the side force and make it zero.

In this way, as the record rotates, the side force generated on the record stylus tracing the sound groove with a certain stylus pressure is canceled out so that it becomes approximately zero when the record is rotated forward or backward. The object of the present invention is to provide an id force cancellation device that operates as described above.

The embodiment of this invention shown in Figs. 2 to 7 will be explained in detail below. Fig. 2 is a front view showing the state before the record is played, and Fig. 3 is a side view thereof. can be,
Reference numeral 1 denotes a pickup arm bracket, which is attached to the machine frame so that it can be rotated from the left side of the record held vertically toward the record, or from the right side of the record toward the record via a control mechanism (not shown). 2 via a support shaft 3 (see U.S. Pat. No. 52-150326 filed earlier by the same applicant as the present applicant).

A pickup arm 4 is supported on this pickup arm bracket I-1 via a support shaft 5 so as to be rotatable from the lead-in groove to the lead-out groove of the record, or in the opposite direction. A pickup cartridge 7 having record needles 6a and 6b on its left and right surfaces is attached to the tip of the pickup arm 4, and a record is attached to the rear end of the pickup arm 4, as described above. When 4 is pulled in its longitudinal direction, a force equal to but opposite in direction to the inside force generated thereby is applied, and a weight 8 is attached to cancel this inside force.

The weight 8 can be freely adjusted by loosening a screw 9 attached to the rear end of the pickup arm 4 and moving it minutely in the longitudinal direction of the pickup arm 4.

As shown in FIG. 3, when the record is in a pre-play state, the pickup arm 4 is driven by a control mechanism (not shown) so that the pickup cartridge 7 is positioned further outside the lead-in groove of the record. The pickup car I ridge 7 is raised in the direction of arrow a so as to be further outward from the lead-in groove of the record.

Further, as shown in FIG. 2, when the record is in a state before being played, the lower end 1a of the pickup arm bracket 1 is rotated by a drive member 11 that rotates the pickup arm 4 to the left or right by a control mechanism (not shown). The pickup arm bracket 1 is pushed horizontally.
The pickup arm 4 is rotated to the left (downward in FIG. 2).

Reference numeral 12 denotes a record guide fork, which is fixed to the machine frame 2.

13a and 13b are stylus pressure springs, the base ends of which are rotatably attached to both sides of the pickup arm bracket 1 by support shafts 14a and 14b, and are spaced a predetermined distance from the base end to the distal end side. However, the stylus pressure adjustment screw 15a.

The stylus pressure adjustment screw 15a is attached to both sides of the pickup arm bracket 1 by means of 15b.

By turning 15b, the needle pressure spring 13
a, 13b are adjusted so that they approach or move away from both sides of the pickup arm bracket 1, so that the tips of the stylus pressure springs 13a, 13b touch the tips 12a, 12b of the guide fork 12 of the record.
The stylus pressure is adjusted by adjusting the strength with which the stylus contacts the stylus.

16 picks up an inside force that is equal to the resultant force of the outside force generated by this and the weight 8 but opposite in direction when the record is driven in a direction that pushes the pickup arm 4 in its longitudinal direction. It is a pressing lever for acting on the arm 4, and the pickup arm 4 is rotatably supported and is rotatably supported coaxially with the support shaft 5.
Further, between this pressing lever 16 and the pickup arm bracket 1, there is a predetermined force for applying an inside force to the pickup arm 4 that is equal to the resultant force of the side force 1 to the side force and the weight 8, but in the opposite direction. A spring 17 is applied, and this pressing lever 1
A pickup arm pressing piece 16a formed at 6 is brought into pressure contact with the pickup arm 4.

As mentioned above, 18 is the pickup arm pressing piece 16 of the pressing lever 16 only when the record is rotated in a direction that pushes the pickup arm 4 in its longitudinal direction.
a is a braking member for the pressing lever 16 that presses against the pickup arm 4 and prevents it from pressing when the record is rotated in a direction that pulls the pickup arm 4 in its longitudinal direction; The base end is located at the pickup arm bracket 1-1.
It is rotatably supported by a support shaft 19 with a predetermined rotational friction (obtained by interposing high viscosity grease on the rotating part).

Furthermore, as mentioned above, when a record is played by rotating in a direction that pulls the quadruple arm 4 in its longitudinal direction, the brake member 18 is provided with an L-shaped pressure lever 16 at the tip thereof. A contact surface portion 18 a is formed that comes into contact with the formed contact piece i6 b and brakes the pickup arm pressing piece 16 a formed on the pressing lever 16 so as not to press the pickup arm 4 . A notch 18b is formed in the portion between the base end portion and the contact surface portion 18a by a predetermined range in the direction of rotation, and a part of the guide fork 12 of the record or A protrusion 20 protruding from a portion of the machine frame 2 is fitted (see FIG. 4), and limits the range of rotation of the braking member 18, as will be described later.

Next, its effect will be explained.

Now, if the record selection device (not shown) instructs the record to be played in the reverse direction, that is, the record is rotated in a direction that pushes the pickup arm 4 in its longitudinal direction, the jukebox player The record is rotatably supported vertically by a record clamp device (not shown) using a mounted motor (not shown) as a drive source, and a part of the record is attached to the middle part of the guide fork 12 of the record. be located without contact with the

Further, as shown in FIG. 2, the pickup arm bracket 1 holding the pickup arm 4 in advance has its lower end 1a driven by the driving member 11 to the left side of the middle part of the guide fork 12 of the record. That is, it is rotated downward in the figure.

When rotating, this pickup arm bracket 1
The braking member 18, which is rotatably attached to the support shaft 19 with a predetermined rotational friction, is also rotated in the same direction.
After the predetermined rotation, the protrusion 20 fitted into the projection 20 restricts the rotation thereof. Therefore, the abutting piece 16b formed at the tip of the pressing lever 16 touches the abutting surface 18a of the braking member 18. The positional relationship is such that they do not face each other.

When the motor mounted on the jukebox player continues to rotate, the undulating member 1 of the pickup arm 4
0 rotates in the direction of arrow C to release the force pushing the pickup arm 4 in the direction of raising it, and the lead-in is further given a force by the spring 21 to rotate the pickup arm 4 in the direction of the lead and in grooves. The pickup arm 4 is pushed down by the lever 22 until the record stylus 6b of the pickup cartridge 7 comes to a position opposite the lead-in groove.

Then, driven by the drive member 11, the pickup arm 4 together with the pickup arm bracket 1
As shown in the figure, it is rotated in the direction of the record 23,
The record needle 6b on the right side of the pickup car I ridge 7 is brought into contact with the lead-in groove on the left side of the record 23, and the performance is started.

In this case, as described above, the record 23 is rotated in a direction that pushes the pickup arm 4 in its longitudinal direction, so an outside force is generated.

At this time, since the abutting portion 16b of the pressing lever 16, which is pulled with a predetermined strength by the spring 17, does not face the abutting surface portion 18a of the braking member 18, the pressing lever 16 The pickup arm pressing piece 16a applies a force to the pickup arm 4 in the direction of canceling the outside force, and the outside force generated as described above becomes zero.

The spring 17 is set to have a strength that makes the outside force zero, or the strength of the spring can be adjusted by an adjusting means (not shown).

Next, when a music selection device (not shown) instructs normal play, that is, play in which the record is rotated in a direction in which the pickup arm 4 is pulled in its longitudinal direction,
The pickup arm bracket 1 holding the pickup arm 4 is driven by the drive member 11 in parallel with the vertical rotation support of the record by a record clamp device (not shown), and as shown in FIG. , the record guide fork] 2 is rotated from the middle part to the right side, that is, to the upper side in FIG.

At the time of this rotation, the brake member 18 attached to the pickup arm bracket 1 is also rotated in the same direction as described above, but the rotation is caused by a notch 18 formed in the brake member 18.
After the predetermined rotation, the protrusion 20 fitted into the projection 20 restricts (stops) the rotation, while the pickup arm 4 and its pressing lever 16 continue to rotate. The abutment piece 16b formed at the tip of the brake member 18 is positioned opposite to the abutment surface 18a of the braking member 18.

Then, as in the case of the above-mentioned reverse play, the pickup arm 4 is laid down until the record stylus 6a provided on the left side of the pickup cartridge 7 comes to a position opposite to the lead-in groove on the right side of the record 23, After that, the pickup arm bracket 1 is attached to the drive member 1.
1, as shown in FIG.
The record needle 6a is rotated so as to come into contact with the right side of the record needle 6a.

Since the pressing lever 16 and the brake member 18 also rotate while maintaining the positional relationship shown in FIG. The suppression lever 16 that comes into contact with the surface portion 18a and is given a force to press the pickup arm 4 by the spunong 17 is braked so that it cannot rotate to press the pickup arm 4, so that the pickup arm pressing piece 16a pickup arm 4
will no longer be pressed.

During normal play, that is, when the record is rotated in a direction that pulls the pickup arm 4 in its longitudinal direction, an inside force is generated. Since the weight 8 as described above is attached to the rear end of the shaft 4, the inside force generated as described above can be reduced to approximately zero.

Note that reference numerals 24a and 24b shown in FIG. 2 are needle tip cleaning brushes.

As explained above, this invention occurs when the record disc 23 is driven in a direction in which the pickup arm 4 is pulled in the longitudinal direction of the jukebox player that plays the record vertically. A force equal to but opposite in direction to the inside force is applied to the pickup arm 4 by way l-8, making the inside force subtracted to zero, and when the record 23 is driven in the direction of pushing the pickup arm 4 in its longitudinal direction, An inside force equal to the resultant force of the generated outside force and the weight 8 but opposite in direction is applied to the pickup arm 4 by pressing the pressing lever 16 pulled by a spring 17 with a predetermined force, and the outside force is subtracted to zero. Since we have provided a side force canceling device for a jukebox player configured to This eliminates sound distortion, improves loss talk, and eliminates needle skipping.

In addition, the structure of this invention is relatively simple and assembly is easy.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of a jukebox player that plays vertically on records and the side force generated by it, Fig. 2 is a front view showing an embodiment of this invention, and Fig. 3
The figure is a side view, FIG. 4 is a perspective view of the side opposite to FIG. 3, and FIGS. 5 to 7 are explanatory diagrams of the operation of this invention. 1...Pickup arm bracket, 2...
... Machine frame, 3 ... Support shaft, 4 ... Pickup arm, 5 ... Support shaft, 6a, 6b.
...Record needle, 7...Pickup cartridge, 8...Weight, 10...
- Pickup arm undulation member, 11...Pickup arm bracket drive member, 12...
...Record guide fork, 16...Press lever of pickup arm, 16a...Pickup arm press piece, 16b...Abutment piece,
17... Spring, 18... Braking member of press lever, 18a... Contact surface portion, 18
b... Notch, 19... Support shaft of the braking member, 20... Protrusion fitted in the notch, 23.
...Record.

Claims (1)

[Scope of utility model registration request] In a jukebox player that plays records vertically, when the record is driven in a direction that pulls the pickup arm in its longitudinal direction, a force equal to but opposite in direction to the inside force generated by this is applied to the pickup arm by the weight. When the given inside force is subtracted to zero, and the record is driven in a direction that pushes the pickup arm in its longitudinal direction, the inside force equal to the resultant force of the resulting outside force and the above weight but in the opposite direction is applied to the spring. This device for canceling side force in a jukebox player is configured to press a pressure lever pulled with a predetermined force against a pickup arm to subtract an outside force to zero.