JPS632995Y2 - - Google Patents

Description

[Detailed Description of the Invention] The invention relates to a drive shaft, a record holder secured to the drive shaft, and a disk-shaped information carrier record having a hole in the center, such as a hard material video record, which is clamped to the drive shaft and the record is rotated by the drive shaft.
the diameter of the centering surface increases from a size smaller than the diameter of the hole in the record to a size larger than the diameter of the hole in the record, forming a conical shape, the centering surface cooperating with an edge of the central hole in the record during operation, and further comprising means for pressing the centering surface and the edge of the central hole in the record against each other.

In known clamping devices of this kind, the record holding member consists of a rotating disk similar to a normal turntable, and this rotating disk has a cylindrical hole at a position opposite to the central hole of the record. The diameter of this hole matches the diameter of the center hole of the record. A centering member having a conical record loading device is provided to move in the axial direction of the drive shaft. Place the record on the disc-shaped holder, then lower the centering member so that the conical centering surface comes into contact with the edge of the center opening of the record, and the centering surface becomes circular. It descends a short distance into the central recess of the plate-like support.

When the centering member is fully lowered, the centering member is pressed downwardly by the pressing spring through the rotating pivot ball, thereby continuing to press the conical centering surface against the edge of the record. (See U.S. Pat. No. 2,634,134).

This known clamping device is unsuitable for certain types of devices. This is particularly true of devices which must rotate the record at relatively high speeds and rotate the record with great precision in conjunction with special reading devices for reading the information contained in the record. This is especially true for video record players.
That is, in this video player, a reading unit is provided under the record, and information on the record is read by a light beam reflected by the record. For such a device, a disc-shaped holder supporting the record and having a diameter equal to that of the record would be unsuitable because the light beam would not be able to reach the record. Another disadvantage of this known device is that the record is positioned on the drive spindle by a relatively complex operation. Before that, it is necessary to place the record with a relatively high degree of accuracy relative to the center of the drive spindle, with its central hole relative to the hole bored in the holding part. Furthermore, since the conical centering member holds the record so that it rests on the surface of the disc-shaped holder, the position of the surface of the record is always aligned with the disc-shaped support member provided below the record. It is determined by the position of the surface. This means that the disk and drive shaft must be manufactured with very high precision if the record surface is to move very precisely over a particular surface during playback. A further disadvantage of this known device is that during operation the spring force must be continuously transmitted to the conical centering member. Therefore, this pressing force also records,
It is transmitted to the bearing of the drive main shaft via the disc and the drive main shaft.

The object of the present invention is to eliminate the drawbacks of the conventional clamping devices mentioned above and to provide a clamping device which is particularly suitable for use in video record players.

The clamping device of the present invention is a device that clamps a rigid disc-shaped information carrier record that rotates at high speed so that it can be easily attached to and detached from a rotatable drive shaft. is rigidly attached to the drive shaft with a flange having a considerably small diameter, and in order to center the record with respect to the axis of the drive shaft, the diameter as seen in the record mounting direction along this axis is set at the center of the rigid record. A record holder comprising a centering member having a rigid centering surface tapered from a size smaller than the diameter of the hole to a size larger than the diameter of the hole; The edge is engaged with the middle portion of the centering surface, and the record is rotated by the centrifugal force generated when the record rotates in response to the rotation of the drive spindle in a plane perpendicular to the axis of the drive spindle. and a pressing device for pressing the edge of the center hole of the record against the centering surface so as to automatically position the record.

According to the present invention, it is quite easy to place a record on the drive shaft, and the operation itself is no different from the operation of placing a record on a normal phonograph turntable. If you simply place the record on the centering member,
The record is then placed at a slight inclination due to the distance between the centering plane and the flange of the record holder, which is located at a distance from this plane. However, according to the invention, after the drive spindle starts moving, the record is automatically corrected to be exactly perpendicular to the axis of the drive spindle due to the centrifugal force acting on it. This centering surface can also be formed from a part of the surface of a sphere.

The record loading device and the record holder are provided with a positioning device for the record loading device that cooperates with each other to position the record loading device with respect to the rotational axis of the drive main shaft, and a protrusion coaxial with the drive main shaft is provided with a positioning device for the record loading device that cooperates with one of the record loading devices. Advantages are obtained by forming one component in the other cooperating component and providing a corresponding cavity in the other cooperating component.

Video record players are typically fitted with a cover that covers the record during operation. The reason is that video records have a speed of 1500 or 1800 rpm.
This is because it rotates at high speed in minutes. One embodiment of the clamping device of the present invention, which is suitable for use in a video player, connects a rotary ring to a record loading device with a rotatable play between the ring and the cover (however, during operation, The ring does not touch the cover at all) and is characterized in that the ring and the record holder are provided with a cooperating magnetic pressing device comprising at least one permanent magnet. The main advantage of this embodiment is that this pressing force occurs directly between the drive spindle and the record loading device, so that the machine does not have to be isolated from rotating parts by rivets. There is no need for a spring connected to the fixing member. Therefore, no axial force acts on the drive main shaft bearing.

As already explained, it is important that the record can be tilted with respect to the axis of the drive spindle when the record is mounted on the record holder. Therefore, there is no need to increase the frictional force between the edge of the hole in the record and the centering surface. This eliminates the need for the drive torque for rotationally driving the record to be generated solely by the friction generated between the edge of the center hole of the record and the centering surface, and therefore This means that the force makes it easier for the record to rotate within a predetermined rotational plane. In an embodiment of the present invention to be described later, at least one record carrier member is provided on the flange of the record holder in order to apply rotational force to the record, and this member is provided with a record carrier member that moves in a direction parallel to the axis of the drive main shaft. a friction block cooperating with the record, and pressing means for pressing this block against the record, so that the record carrier member can be moved at a distance greater than the distance measured from the axis of the drive shaft to where the centering member is located. position by distance.

The present invention will be explained in detail with reference to the drawings below.

The video player 1 of FIG. 1 comprises a housing 2 and a cover 3 pivotally connected thereto. A large number of buttons 4 and 5 are provided on the front surface of the housing 2, and various functions of the player 1 are operated by these buttons. A record holding section 6 is provided approximately at the center of the top of the housing, and this record holding section 6 holds a video record 7.
Together with the central hole 8, it constitutes a part of a clamping device for positioning the video record. A radially extending slot 9 is formed in the upper surface of the housing 2 next to this record holder 6, into which a focusing device 10 is moved radially by means of a device provided in the housing 2. Provide as much as possible. This focusing device 10 is provided with an objective lens 11, which allows the light beam from the laser light source to be irradiated onto the lower surface of the record 7, and also returns the light reflected by the record 7 to the photoelectric information detection device. be able to.

As clearly shown in FIGS. 2 to 5, the record holder 6 is rigidly mounted on the drive shaft 12.
is the record 7 regarding the axis 13 of the drive spindle 12.
a centering member 14 having a centering surface 15 for centering the centering surface 15, the diameter of which increases from a smaller dimension to a larger dimension compared to the diameter of the record hole 8; Tapered to . During operation, the centering surface 15 cooperates with the edge 16 of the record hole 8, as will be explained with reference to FIGS. 4 and 5 hereinafter. Also, during operation, the edge 16 of this record hole is pressed against the centering surface 15 by a record loading device, which will be explained later. In the embodiment shown in the drawings, the shape of this centering surface 15 is a truncated cone.

A centering member 14 rigidly connected to the record holder 6 is attached to the record holder 6 together with a flange 17 having a diameter considerably smaller than the diameter of the record 7.
It constitutes. record 7, hole 8
When loaded so that it is inserted into the centering member 14,
The record is locked in the middle part of the centering surface 15, which has a diameter equal to the diameter of its hole, and in this state, when viewed from the other fixed part of the record holder 6, namely the flange 17, in the direction of the axis 13 of the drive shaft 12. They will be separated by a certain distance. As a result, when the record 7 made of a hard material is placed on the centering member 14, the record 7 may be tilted as shown in FIG. 3, but the range of the tilt is limited. The reason is that record 7 has flange 17.
abutting one or two of the three record carrier members 18 arranged at angular intervals equal to the circumference of the record carrier member 18;
This is because it does not slope any further. This record carrier member 18 operates to apply rotational force to the record 7 made of a hard material, and each of the record carrier members 18 is provided with a friction block 19 that can move in a direction parallel to the axis 13 of the main shaft 12. There is. When record 7 is placed, friction block 1
9 is elastically pressed against the bottom surface of the record. This friction block 19 has a part 20 concentrically surrounding the friction block, an annular part attaching the carrier member to the flange 17, and a part connecting the friction block to the annular part, so as to press the block elastically against the record. It is formed integrally with the operative flexible connecting part 21. In this way, it can be manufactured extremely easily, and
A monolithic carrier member 18 is obtained which can also be easily inserted into the corresponding cylindrical opening of the flange 17.

The clamping device is also shown at number 22 in Figures 1, 4 and 5.
It is equipped with the record loading device shown in . During operation, this record loading device 22 acts to press the edge 16 of the record hole 8 against the centering surface 15. For this purpose, the centering member 14 and the record loading device 22 are provided with mutually cooperating pressing devices. This pressing device includes an annular permanent magnet 23 provided in the record holding section 6 and a record loading device 22.
It consists of a soft iron disc 24 provided on the holder. It is obvious that a second permanent magnet may be provided in the record loading device 22 instead of this soft iron disk, and it is also possible to provide the record holding section 6 with a soft iron disk and the record loading device 22 with a permanent magnet. You can also do it.

Further, the record loading device 22 and the record holding section 6 are provided with positioning devices for the record loading device that cooperate with each other for positioning the record loading device with respect to the axis 13 of the drive main shaft 12. This positioning device comprises a projection 25 which is coaxial with the drive shaft 12 and corresponds to a cylindrical opening 26 of the record loading device. The record loading device (see especially FIGS. 4 and 5) 22 includes a rotating ring 27 loosely and rotatably connected to the cover 3.
, and the rotating ring 27 is prevented from completely contacting the cover 3 during operation. For this purpose, the cylindrical member 28 is provided with a ring 27 and a flange 29 at the end. This flange is located in a bush (bearing) 30 connected to the cover 3. Three screws 31 passing through the wall of this bushing 30 hold the flange 29 in the bushing 30 when the cover 3 is opened.

The operation of the clamping device according to the present invention is as follows. The cover 3 is opened and the video record 7 is placed on the record holding part 6 by hand. The edge 16 of the hole 8 of this record 7 comes into contact with the middle part of the centering surface 15 of the centering member 14. Generally, when placing a record, the axis 13 of the drive main shaft 12
Although it is slightly oblique with respect to the plane perpendicular to
It is not so inclined as to prevent the cover 3 from being closed. By closing the cover 3, the record loading device 22 can be positioned over the centering member 14, and when this cover is completely closed, the record loading device 22 is magnetically pressed onto the record 7. be done. Since the opening 26 of the record loading device 22 cooperates with the positioning pin 25, the record loading device 22 is always correctly positioned with respect to the record holding section 6. In this state, the record loading device 22 no longer loads the
0 and becomes in a state in which the drive main shaft 12 can be driven. This main shaft 12 is connected by means not shown to an electric drive motor, the rotation of which is controlled by an electronic speed control device. When the record 7 begins to rotate as the main drive shaft 12 rotates, the record 7 will move along the axis 13 of the main drive shaft 12 due to the centrifugal force acting on it.
It rotates automatically until it is located in a plane that is exactly at right angles to, in this example a horizontal plane. record 7
The rotational driving torque of is sufficiently transmitted by the friction block 19, so that the friction between the edge 16 of the record hole 8 and the centering surface 15 is not strong enough to prevent the above-mentioned rotation of the record. . After finishing playing video record 7 and opening cover 3,
The record can be easily taken out by lifting it from the record holding part 6.

FIG. 5 shows that a record made of a flexible material, denoted by reference numeral 7', is held using the above-mentioned clamping device of the present invention.
This shows how to place it on the record holding section 6. When using flexible records, the record carrier member 18 is unnecessary and instead a carrier ring 3 made of deformable material is used.
Use 2. This ring is an O-ring whose diameter is greater than the maximum diameter of the centering surface 15 and equal to the diameter of the carrier ring 27. The material of the flexible record 7' is slightly deformed by the centering surface 15, so that the record is correctly centered in the record holder 6. On the other hand, the driving torque for rotating this record is provided by the friction generated between the O-ring 32 and the record 7' due to the influence of the pressing force exerted by the carrier ring 27. It has been found that when using a video recorder with a central hole of 35 mm, it is preferable for the O-ring to have a diameter of approximately 40 mm.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a video player equipped with the clamp device of the present invention, Fig. 2 is an enlarged perspective view of the record holder shown in Fig. 1 and its surroundings, and Fig. 3 is a sectional view of the record holder; FIG. 4 is a sectional view of the record holding section and the record loading device, and FIG. 5 is a sectional view showing the state when a flexible record is mounted. DESCRIPTION OF SYMBOLS 1... Video player, 6... Record holding part, 10... Focusing device, 14... Centering member, 1
5... Centering surface, 18... Record carrier member, 19... Friction block, 22... Record loading device, 25... Positioning pin, 26... Cylindrical opening, 27... Rotating ring.

Claims (1)

[Scope of utility model registration request] In a device for clamping a high-speed rotating rigid disc-shaped information Chiaria record 7 to a rotatable drive shaft 12 so that it can be easily attached and detached, the device is rigidly attached to the drive shaft and has a diameter equivalent to that of the record. A flange 17 with a small diameter is rigidly attached to the drive shaft, in order to center the record with respect to the axis 13 of the drive shaft, the diameter of which, seen along this axis in the direction of record mounting, is fixed to the center of the rigid record. Rigid centering surface 1 tapered from a size smaller than the diameter of the hole 8 to a size larger than the diameter of the hole 8
When a record is mounted on the record holder, the edge 16 of the center hole of the record is engaged with the middle part of the centering surface, and the centering member 14 of the drive shaft is The edge of the center hole of the record is set as a centering surface so that the record is rotated by the centrifugal force generated when the record rotates in response to rotation, and is automatically positioned in a plane perpendicular to the axis of the drive main shaft. a pressing device 23 for pressing the
24, 27.