JPH0124727Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a record adsorption device that can firmly adsorb a record to be played and place it on the turntable of a record reproducing device.

It is well known that warping of records causes cross-modulation distortion, which impairs the quality of reproduced sound. In view of this, the applicant
Patent Application No. 80645 (Sho 57-80645) filed on May 26th
(No. 195302), we proposed a device for fixing records using the adsorption effect of negative pressure. Briefly explaining this device, it has a disc body that is removably interposed between a record to be played and a turntable. An air chamber is provided. On the other hand, on the top surface of this disc body, there is an annular outer that is in close contact with the outer circumferential edge (groove guard) of the record and the inner circumferential edge near the label section, forming an airtight space between them. A seal and an inner seal are provided upright. This space and the air chamber are communicated with each other through an air passage such as a through hole, and by reducing the pressure of the air chamber with a vacuum pump or the like, the air chamber is placed on the disc body. The recorded record is firmly suctioned and fixed onto the disc body. According to actual measurements, the suction force is quite strong, about 250 kg, and as a result, the record is firmly fixed on the disc body with the warp corrected. However, if a record is adsorbed with a fairly strong force as described above with vegetable or mineral fibrous or granular dust attached to the disk,
It has been found that the dust gets buried in the sound groove of the side of the record that comes into contact with the cylindrical body, and that when the record is turned over and played on this side, the dust generates a considerable amount of noise.

Therefore, the purpose of this invention is to prevent fine fibrous or granular dust from being buried in the surface of the record when the record is adsorbed onto the disk, and also to provide a seal that forms the space. To provide a record disc suction device with a simplified structure.

In order to achieve the above objectives, this invention
An annular outer seal that contacts the outer periphery of the record, an inner seal that contacts approximately the outer periphery of the label portion of the record, and an integrally formed seal between the outer seal and the inner seal, A protective sheet made of a softer material is coated on the top surface of the disk body on which the record is attracted, and fine dust is buried in this protective sheet to protect the sound groove of the record and also to prevent the sound grooves in the space. The structure of the seal forming the seal is simplified.

Hereinafter, embodiments of this invention will be described in detail with reference to the accompanying drawings.

Referring to FIGS. 1 and 2, the record suction cup 1 is a disc body having approximately the same diameter as a turntable of a record playback device and configured to be removably placed on the turntable. It has 2.
In this embodiment, the disc body 2 includes a donut-shaped base plate, and a pair of upper and lower center plates 4 attached to the central opening of the base plate from above and below to form an airtight air chamber 3 therein. It is composed of a center frame 5. In this embodiment, the disc body 2 is made by cutting a solid aluminum plate, and has a first annular groove 6 formed at its outer peripheral end, and is integrally formed with its inner wall within its central opening. The spacer ring 7 has a spacer ring 7 that is cut according to the method, and a second annular groove 8 that is formed between the spacer ring 7 and the inner wall of the opening. An annular outer seal 9 is installed in the first annular groove 6, and an annular inner seal 10 is installed in the second annular groove 8. A protective sheet 11 is integrally provided between the two. In addition, a pair of through holes 12 are formed in this disc body 2 from opposite directions from the outer peripheral end wall toward the air chamber 3. In this case, one of the through holes 12 is A check valve 13 connected to a vacuum pump (not shown) is attached, and an on-off valve 14 for selectively communicating the air chamber 3 with the atmosphere is attached to the other through hole 12. Note that the spacer ring 7 also has a pair of communication holes 15, 15 formed coaxially with the through holes 12, 12. The center plate 4 and the center frame 5 are connected by a spacer ring 7
It consists of disks of the same diameter formed so that they can be held from above and below, and each disk has a center point on the rotation axis of the record suction cup 1, which is shown by the imaginary line in FIG. a shaft cylinder 18 for forming a center hole 17 through which the spindle 16 is inserted;
19 are provided. In this embodiment, the lower end of one barrel 18 is enlarged in diameter so as to tightly cover the other barrel 19. A plurality of columns 20 are erected on the outer periphery of the center frame 5, and by screwing the center plate 4 to these columns 20, the center plate 4 and the center frame 5 sandwich the spacer ring 7. is firmly fixed to the disc body 2 in this manner, and
An air chamber 3 will be formed inside it. In this case, in order to improve the airtightness of the air chamber 3, grease or the like is applied to the joint surfaces of the respective shaft cylinders 18, 19 and the joint surfaces of the center plate 4 and the center frame 5 to the spacer ring 7.

The outer seal 9, the inner seal 10, and the protective sheet 11 connected thereto are integrally formed from a flexible material such as neoprene rubber. As shown in FIGS. 3 and 4, the outer seal 9 includes an annular base 21 formed to be forcibly inserted into the first annular groove 6 of the disc body 2. , and a thin flange 22 formed to extend outward from the upper end of the base portion 21 at a slight upward angle. In this case, the outer peripheral end of the flange 22 is normally located above the upper surface of the disc body 2, and the outer peripheral edge including the groove guard 24 of the record 23 placed on the record disc suction device 1. It has come to be closely attached to Furthermore, the protective sheet 11 is connected to the upper part of the inner circumferential wall of the base 21 . In addition, reference numeral 25
26 is a notch for inserting the check valve 13 and the on-off valve 14 into the through hole 12, and 26 is a rib formed on the inner circumferential wall of the base 21 below the protective sheet 11 to prevent it from coming off. On the other hand, the inner seal 10 has a disc body 2, as shown in FIGS. 5 and 6.
an annular base 28 formed to be forcibly inserted into the second annular groove 8 of the base 28; and a thin flange formed to extend inward from the upper end of the base 28 at a slight upward angle. It is equipped with 29. In this case, the inner peripheral end of the flange 29 is also normally located above the upper surface of the disc body 2, similar to the flange 22 described above, and
It is now in close contact with the non-recording surface adjacent to the label section. Also, this inner seal 1
0 includes a plurality of vertical grooves 30 formed in the outer peripheral wall of the base 28. The base 28 is installed in the second annular groove 8 so as to leave a predetermined space between it and the bottom of the groove, and there is also a hole on the inner wall of the second annular groove 8 which is held down by the outer peripheral edge of the center plate 4. A rib 31 for stopping is provided. moreover,
The protective sheet 11 is connected to the upper part of the outer peripheral wall of the base 28, and in this case, a through hole 32 is provided in a portion located above the vertical groove 30. In this way, the protective sheet 11 is formed into a donut plate shape with the outer periphery connected to the outer seal 9 and the inner periphery connected to the inner seal 10, and the outer seal 9 and the inner seal 10 are each shaped like a disk. When attached to the outer circumference and inner circumference of the body 2, it is also attached to the upper surface of the disc body 2. In this case, in order to improve the adhesion between the disc body 2 and the protective sheet 11, they may be bonded together with an adhesive.

Referring to FIGS. 7 and 8, the check valve 13
The cylinder 33 is airtightly inserted into the through hole 12, and the valve body 35 is made of a flexible material such as neoprene rubber and is held by a gate-shaped frame 34 formed at the tip of the cylinder 33. has been done. This valve body 35 is formed into a bottomed cylindrical shape having an outer diameter substantially larger than the inner diameter of the cylinder 33, and its bottom side is attached within a retaining ring 36 provided on the frame 34, and the other side is attached to a retaining ring 36 provided on the frame 34. The peripheral wall on the opening side is inserted into the cylinder 33 in an airtight manner. Therefore, when a hose (not shown) extending from a vacuum pump is connected to the cylinder 33 and the air in the through hole 12 and the air chamber 3 is sucked, the negative pressure causes the valve body 35 to move as shown by the imaginary line in FIG. It deforms as if collapsing inward. Then, when the hose is removed and the cylinder 33 is exposed to the atmosphere, the pressure difference causes the state to return to the solid line shown in the figure.
The through hole 12 is shielded from the atmosphere.

On the other hand, as shown in FIG. 9, the on-off valve 14 includes a cylinder 38 that is airtightly inserted into the through hole 12, and a neoprene rubber that is rotatably placed on the head side of the cylinder 38. It consists of a cap 40 made of a flexible material such as. In this case, a through hole 39 is formed in the peripheral wall on the head side of the cylinder 38, and the cap 40 selectively opens the through hole 39 by rotating the cap 40. It has an opening 41 that opens and closes. In addition, reference numeral 42 is an annular groove provided on the outer circumferential wall of each cylinder 33 and 38, and this annular groove 42
A known seal ring is fitted therein.

Next, the operation of this invention will be explained. Before starting to play a record, the record suction cup 1 is set on the turntable of a record reproducing device. In this case, the length of the center spindle 16 of the turntable is usually about 15 mm, and the thickness of the record suction cup 1 is about 9.5 mm.
The center spindle 16 passes through the center hole 17 and projects upward by about 5.5 mm. and,
When the record disc 23 is placed on the suction cup 1 using the center spindle 16 as a guide, the space between the record disc 23 and the upper surface of the disc body 2 is airtightly sealed by the outer seal 9 and the inner seal 10. Next, the cap 40 is rotated to shift its opening 41 from the through hole 39, and the on-off valve 14 is closed.
A hose from a vacuum pump (not shown) is connected to the cylinder 33 of the check valve 13 to operate the vacuum pump. As a result, the valve body 35 of the check valve 13 is deformed as shown in imaginary lines as described in the explanation related to FIG. and depressurized,
Record disc 23 through vertical groove 30 and through hole 32
The air in the space between the upper surface of the disc body 2 and the upper surface of the disk body 2 is also sucked, and that part becomes in a negative pressure state. Therefore, the record disc 23 is firmly suction-fixed to the protective sheet 11 on the disc body 2, and even if the record disc 23 has some warpage, it is corrected by this suction-fixation. Thereafter, when the hose is removed from the check valve 13, the valve element 35 closes due to the pressure difference between the atmosphere and the negative pressure inside the record suction cup 1, thereby reliably closing the through hole 12. In this way, the inside of the record suction cup 1 is maintained at a negative pressure state. In that case, even if a small amount of air flows in from each seal part, the air chamber 3 has a large volume under negative pressure. Since it acts as an accumulator, it is possible to suction and fix the record 23 for a long time. In addition, according to experiments, it was possible to sufficiently hold the disc in place for about 45 minutes, far exceeding the single-sided performance time of an LP record. When you rotate the turntable,
This suction cup 1 rotates steadily together with the turntable without slipping due to the frictional resistance due to its own weight, lowers the needle of the pick-up cartridge onto the record 23, and enters into a playing state. In that case, as described above, the record 23 is fixed firmly by suction on the disc body 2 so that its warp is corrected, so cross-modulation distortion due to the warp of the record 23 and sub-effects from the speakers may occur. Highly faithful reproduced sound can be obtained without rumble noise caused by projecting sound pressure. Also, record 2
3 is adsorbed onto the disk body 2 through the protective sheet 11, so fine dust etc. caught between the protective sheet 11 and the record disc 23 during crimping are removed by the protective sheet, which is softer than the record disc 23. It will be buried on the 11 side, and will hardly stick to the record 23.

To remove the record 23 at the end of the performance, etc., rotate the cap 40 and open the opening 41.
aligns with the through hole 39 and opens the on-off valve 14. As a result, air is sucked into the air chamber 3 through the through hole 12 and the communication hole 15, and air is also introduced between the record 23 and the disc body 2 via the vertical groove 30, and due to negative pressure. The adsorption state is released. In addition, in order to release this suction state more quickly and to be able to remove the record 23 in a short time, as shown in FIG. A plurality of grooves may also be provided extending radially from the portion corresponding to 30. On the other hand, by tapering the upper surface of the disk body 2 so that it slopes slightly downward toward the center, the adaptability to warped records can be further improved.

As is clear from the above description of the embodiment, according to this invention, it can be easily set on an existing turntable in a removable manner, and it is also possible to correct warped records even if they are warped. It can be firmly fixed by adsorption. Furthermore, since the record is adsorbed onto the disc through a softer protective sheet, there is no possibility that dust or the like caught between the discs will stick to the record and deteriorate the sound quality. Furthermore, since the protective sheet is integrally formed with the outer seal and the inner seal, assembly work is facilitated and the airtightness of the mounting portions of each seal is improved.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway plan view of the record suction cup according to this invention, Figure 2 is a sectional view taken along the - line, and Figure 3 is a partially cutaway front view of the outer seal and inner seal. Figure, 4th
The figure is an enlarged sectional view of the main part of the outer seal, Fig. 5 is a front view with the inner seal part cut away and partially cut away, Fig. 6 is an enlarged sectional view of the main part, and Fig. 7 is a front view of the check valve. 8 is a cross-sectional view taken along the - line, and FIG. 9 is a cross-sectional view of the on-off valve. In the figure, 1 is a record suction cup, 2 is a disc body, 3 is an air chamber, 4 is a center plate, 5 is a center frame, 6 is a first annular groove, 7 is a spacer ring, 8
is a second annular groove, 9 is an outer seal, 10 is an inner seal, 11 is a protective sheet, 12 is a through hole, 13 is a check valve, 14 is an on-off valve, 16 is a center spindle, 17 is a center hole, 22, 29 is a flange, 21 and 28 are bases, 23 is a record, 30
32 is a vertical groove, and 32 is a through hole.

Claims (1)

[Claims for Utility Model Registration] A record disc suction device that is detachably interposed between a turntable of a record playback device and a record to be played, and rotates together with the turntable while holding the record by suction. The turntable includes a disc body having a center hole through which the center spindle of the turntable is inserted, and the disc body includes an air chamber airtightly formed around the center hole in the center of the disc body; a through hole opened from the air chamber toward the outer peripheral end wall, and
a valve device installed in the through hole, detachably connected to a negative pressure source such as a vacuum pump, and capable of selectively communicating with the air chamber and opening the air chamber to the atmosphere; an annular outer seal portion that is in close contact with the periphery of the record; an annular inner seal portion that is in close contact with the outer periphery of the label portion of the record;
an annular protective sheet portion located between the outer seal portion and the inner seal portion and integrally formed with these seal portions, and made of a material softer than the record disc; a sealing means for forming an airtight space by the protective sheet part and the record; and an air passage communicating the space and the air chamber; It is placed concentrically on a disc body, and when the negative pressure source reduces the pressure in the air chamber and the space through the valve device, the negative pressure causes an adsorption action to cause the air to flow through the protective sheet part. A record disc suction device, characterized in that it is suctioned and fixed onto the disc body.