JPS6315641B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fully automatic record player, and particularly to a mechanism for switching between lead-in and lead-out operations of a tone arm.

The tone arm is activated by utilizing the cam surface of the cam body, which has a gear part on its circumference, and which engages with the gear part of the turntable shaft and starts rotating in response to operating the start button and detecting the end of a performance. It is well known to perform lead-in operations (rotating the tonearm from an armrest position to a playing position) and lead-out operations (rotating the tonearm from a playing position to an armrest position).

By the way, if the cam body has a configuration in which two systems of cam surfaces are used and one cam surface is used to perform the lead-in operation and the other cam surface is used to perform the lead-out operation, which cam Although it is necessary to provide an operation switching lever that uses a surface to select which operation to perform, the present invention is configured to automatically position the operation switching lever by detecting the position of the tone arm. This has been devised to ensure that lead-in and lead-out operations can be achieved without malfunction.

Hereinafter, a detailed description will be given with reference to embodiments shown in the drawings.
First, the structure of a fully automatic record player according to the present invention will be explained with reference to FIGS. 1 and 2. FIG. 1 is a bottom view, and FIG. 2 is a side view, and in these figures, a tone arm (not shown) is fixed below the tone arm shaft 1. 2 is a turntable shaft for rotationally driving a turntable (not shown), and has a small gear 2a and a protrusion 2b. Reference numeral 3 denotes a cam body for performing lead-in and lead-out operations of the tone arm, and a large gear 3a that meshes with a small gear 2a is formed on the outer periphery. In the stopped state shown in FIG. 1, the small gear 2a faces the notch 3b of the large gear 3a, and the two do not mesh in any way.

The cam body is provided with a cam groove 4, the details of which are shown in FIGS. 6 and 7. FIG. 7 is a sectional view taken along line XX' in FIG. The cam groove 4a in range () is used during lead-out operation,
The cam groove 4b in range () is used during the lead-in operation and is a shallow groove.
The cam groove 4c is a deep groove to prevent the tone arm from rotating again toward the performance position immediately after the lead-out operation is completed, and will be explained in detail later. 4d is an inclined portion connecting the shallow cam groove and the deep cam groove. An operation switching lever 5 for selecting which of the cam grooves 4b and 4c to use is rotatably supported on the cam body 3 around a shaft 5a.
A pin 5b is installed in the hole.

A tone arm lever 6 is fixed to the tone arm shaft 1, and rotation of the cam body 3 is transmitted to the tone arm lever 6 via a drive member 7. That is, the contact piece 7a (having a friction material at the tip) provided at one end of the drive member 7 contacts the tone arm lever 6, and the cam follower pin 7b provided at the other end contacts the cam groove of the cam body 3 . It is inserted in 4. The drive member 7 is rotatable about a shaft 8 and can see-saw about a fulcrum 8a. The drive member 7 is pressed against the fulcrum 8a of the seesaw by a spring coil (not shown), and is urged so that the cam follower pin 7b follows the cam groove 4.

Now, in order to detect the position of the tone arm and position the operation switching lever 5 mentioned above, a first detection member 9 and a second detection member 10 are provided.
The position of the tone arm, that is, the position of the tone arm lever is detected, and in response to this, the operation switching lever 5 is positioned. The first detection member 9 is the chassis 11
It is rotatable about a shaft 9a set on the tone arm lever 6, and one end contacts a pin 6a set on the tone arm lever 6, and the other end contacts a through hole provided at one end of the second detection member 10. 10a. The second detection member 10 is rotatable about a shaft 10b installed in the chassis, and has a substantially X-shaped cam groove 10c (first 3) are formed. 12 is a stopper piece of the first detection member 9.

Note that figure number 13 is a tone arm lift shaft for raising the tone arm. In addition, two trigger levers 14, 14' called a lower trip pawl and an engagement pawl are attached to the cam body 3 .
is provided, and comes into engagement with the protrusion 2b of the small gear 2a when the start button is operated or when the record playing ends, and the small gear 2a and the large gear 3a are brought into meshing state. This can be seen, for example, in 1973.
It is well known from Publication No. 14165 and the like.

Next, the operation will be explained. FIG. 1 shows the tone arm in a stopped state on the armrest.
At this time, one end of the first detection member 9 is in contact with the pin 6a on the tone arm lever 6 and is in the position shown in FIG.
It engages with the X-shaped cam groove 10c of the detection member 10. When the cam body 3 rotates from this state, the position of the operation switching lever 5 does not change at all. That is,
Since the operation switching lever 5 closes the entrance of the cam groove 4c and opens the entrance of the cam groove 4b, the cam groove 4b is in a selected state.

Then, when you operate the start button (not shown),
When the turntable shaft 2 starts rotating, the small gear 2a and the large gear 3a are brought into mesh with each other, and the cam body 3
starts rotating in the direction of the arrow shown. Now pin 7b
When the drive member 7 engages from the deep groove 4c to the shallow groove 4a, the drive member 7 seesaws about the fulcrum 8a, and the abutting piece 7a abuts the tone arm lever 6. Therefore, the tone arm lift shaft 13 moves in the direction of the arrow shown in FIG. 2, and the tone arm rises above the armrest base.

By the way, when the cam body 3 is rotating within the range () with respect to the pin 7b, the driving member 7 is rotating relative to the pin 7b.
b moves toward the center of the cam body 3 , so the shaft 8
Rotate counterclockwise around the center. Normally, the counterclockwise rotation of the driving member 7 causes the tone arm lever 6 in contact with the abutment piece 7a to rotate in the direction of arrow a shown in the figure (this is the lead-out direction), but at this point Since the tone arm is in the armrest position, the tone arm lever 6 does not rotate at all, and the drive member 7 rotates counterclockwise with the abutment piece 7a slipped (see FIGS. 3 and 4). (see figure).

Now, when the cam body 3 rotates relative to the pin 7b in the range ( The direction of rotation of the drive member 7 when in contact with the arm lever 6 is determined by the pin 7b.
moves away from the center of the cam body 3, so it reverses and starts rotating clockwise. In response to the clockwise rotation of the drive member 7, the tone arm lever 6 is rotated in the direction of arrow b in the figure, and a lead-in operation of the tone arm is performed. During the lead-in operation, the rotation range of the tone arm lever 6 is regulated by a well-known record size selection mechanism (not shown), so when the tone arm is rotated to the end where the record starts playing, Subsequent rotation of the tone arm lever 6 is prevented, and the tone arm lever 6 continues to rotate clockwise with only the contact piece 7a slipping.

Now, when the tone arm moves from the armrest stand to the record playing start position by the lead-in operation, the pin 6a on the tone arm lever 6 and the first
Since the contact relationship with one end of the detection member 9 is released,
The first detection member 9 is moved clockwise by a spring,
Further, the second detection member 10 rotates counterclockwise and moves to the position shown in FIG. Therefore, 1 of the cam body 3
Just before the end of the rotation, the pin 5b on the operation switching lever 5 is guided again to the X-shaped cam groove 10c provided in the second detection member 10, and as a result of the counterclockwise rotation of the second detection member 10, the pin 5b is finally The operation switching lever 5 rotates counterclockwise around the shaft 5a, and rotates in the cam groove 4b.
Since the inlet of the cam groove 4c is closed and the inlet of the cam groove 4c is opened, the cam groove 4c is switched to the selected state. This switching of the operation switching lever 5 is further facilitated by the pin 7b coming into contact with the side surface 5' of the operation switching lever 5. When the pin 7b passes through the inclined portion 4d and moves into the deep cam groove 4c, the small gear 2a faces the notch 3b of the large gear 3a, and the rotation of the cam body 3 ends (see FIG. 5). In this state, the drive member 7 seesaws around the fulcrum 8a,
At the same time that the contact between the contact piece 7a and the tone arm lever 6 is released, the tone arm lift shaft 13 also descends (moves in the opposite direction of the arrow in FIG. 2).
The record is now playing.

Now, in response to the operation of the redirect button (not shown) at the end of the record playing or during the record playing, the small gear 2a and the large gear 3a are turned on again as is well known.
are engaged, and the cam body 3 begins to rotate clockwise. As the pin 7b moves toward the center of the cam body 3 due to the rotation of the cam body 3 in the range () relative to the pin 7b, the drive member 7 rotates counterclockwise about the shaft 8 and the tone arm The lever 6 is rotated in the direction of arrow a to perform a lead-out operation, and the tone arm is returned to the armrest position. When the cam body 3 further rotates and the cam body 3 reaches the rotation state in the range (), the operation switching lever 5 closes the entrance of the cam groove 4b and the cam groove 4
Since the entrance of c is open, the pin 7b is inserted into the cam groove 4.
Guided to side c. By the way, since the cam groove 4c is a deep groove, the driving member 7 moves in a seesaw manner, and the abutting relationship between the abutting piece 7a and the tone arm lever 6 is released. Therefore, since the tone arm lever 6 does not rotate due to the rotation of the cam body 3 in the range (), the tone arm does not perform lead-in operation, and the tone arm remains at the armrest position. It is.

Now, when the tone arm returns to the armrest position, the pin 6a on the tone arm lever 6 and one end of the first detection member 9 are brought into contact again, and the first detection member 9 and the second detection member 10 are again in contact with each other. Move to the position shown in the diagram. Therefore, when the cam body 3 makes approximately one rotation, the pin 5b on the operation switching lever 5 is guided to the X-shaped cam groove 10c provided in the second detection member 10, and eventually the operation switching lever 5 again selects the cam groove 4b. state (the position shown in FIG. 1). This switching is further facilitated by the pin 7b coming into contact with the side surface 5' of the operation switching lever 5, as described above.

Note that when the tone arm is manually returned to the armrest position from the record playing state shown in FIG. 10, the operation switching lever 5 is returned to the initial position shown in FIG.

Furthermore, when the tone arm is manually brought to the performance position, the contact relationship between the pin 6a of the tone arm lever 6 and the first detection member 9 is also released, so that the first detection member 9 rotates clockwise, and the second detection member 10 rotates counterclockwise. Then, the operation switching lever 5
Since the upper pin 5b is engaged with the X-shaped cam groove 10c of the second detection member 10, the operation switching lever 5 also rotates counterclockwise and moves to the position shown in FIG. That is, the operation switching lever 5 is in the selected state of the cam groove 4c in order to enable the lead-out operation of the tone arm after the record playing is finished.

According to the present invention described above, the lead-in operation and lead-out operation of the tone arm are automatically switched in response to the difference in the position of the tone arm, so that the lead-in operation and lead-out operation can be performed reliably without malfunction. can be achieved.

[Brief explanation of the drawing]

The drawings all show a fully automatic record player according to the present invention, and FIG. 1 is a bottom view in a stopped state, FIG. 2 is a side view of the same, and FIG. 3 is a bottom view after the cam body starts rotating. 4 is a side view of the same, FIG. 5 is a bottom view in a playing state, FIG. 6 is a diagram showing the shape of the cam groove, and FIG. 7 is a cross-sectional view taken along the line X-X' in FIG. 6. 1 is the tone arm axis, 2 is the turntable axis,
3 is a cam body; 4a, 4b, 4c are cam grooves; 5 is an operation switching lever; 6 is a tone arm lever; 7 is a driving member; 9 and 10 are detection members; 13 is a tone arm lift shaft.

Claims (1)

[Scope of Claims] 1 (a) A cam body that rotates once in response to operation of a start button and detection of end of performance, etc.; (b) A cam follower pin at one end engages with a cam groove of the cam body. (c) a drive member that is rotatable in the radial direction as the cam body rotates, and is provided to be capable of see-saw operation due to the difference in depth of the cam groove; (c) seesaw movement of the drive member; (d) a tone arm lever that rotates the tone arm in a lead-in direction or a lead-out direction in relation to the rotation of the drive member; e) an operation switching lever rotatably provided on the cam body to switch the engagement path of the follower pin of the drive member with the cam groove of the cam body to a first engagement path or a second engagement path; (f) detecting the armrest position of the tone arm, setting the operation switching lever so that the follower pin moves along the first engagement path of the cam groove, and detecting movement of the tone arm to the playing position; and a position detection member that sets the operation switching lever so that the follower pin moves in the second engagement path of the cam groove, (g) the follower pin of the drive member moves in the first engagement path of the cam groove. When moving along the road, the driving member raises the tone arm lift shaft, rotates the tone arm lever in the lead-in direction, and then lowers the tone arm lift shaft, and (h) the following pin of the driving member moves into the cam groove. When moving through the second engagement path, the driving member is configured to raise the tone arm lift shaft, rotate the tone arm lever in the lead-out direction, and then lower the tone arm lift shaft. A fully automatic record player.