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US 4,509,157 AGranted
Disc player apparatus with an improved disc clamper
AssigneeTokyo Shibaura Denki Kabushiki Kaisha
InventorKaoru Morinaga
Life of this patent
Estimating the term…
Abstract
A disc clamper includes a clamp member for holding a disc against a turntable and a support member for supporting the clamp member. The clamp member is provided with a permanent magnet, and the support member has a winding. The winding is coaxially arranged to the magnet. When a certain DC current is applied to the winding, the clamp member is subjected to an electromagnetic repelling force effected between the winding and the magnet. Then, the disc is fixed to the turntable by means of the electromagnetic repelling force, and the clamp member is mechanically free from the support member.
Claims31
A clamper for a disk player apparatus comprising:
- turntable means for receiving a disc to be played back;
- clamp means for engaging and holding the disc against said turntable means and between said turntable means and said clamp means when said clamp means is in a first position and for permitting the removal of the disc from the turntable means when said clamp means is in a second position;
- support means positioned opposite said turntable means for rotatably and slidably supporting said clamp means, said clamp means being slidable along a direction running from said support means to said turntable means and, when said clamp means is in said first position, said clamp means being mechanically free from said support means;
- electromagnetic force means fixed solely to said clamp means and said support means for selectively clamping said clamp means against and releasing said clamp means from said turntable means;
- means for selectively supplying a first current to said electromagnetic means, said first current causing said electromagnetic means to generate an electromagnetic force which urges the clamp means toward said turntable means so that the clamp means engages and clamps the disc against said turntable means;
- and
- means for selectively supplying a second and opposite current to said electromagnetic means, said second current causing said electromagnetic means to generate an electromagnetic force which urges the clamp means away from said turntable means so that the clamp means is spaced from said turntable means.
4 more elements
The clamper of claim I wherein said clamp means includes a hole formed at its rotational center;
- and
- said support menas includes a guide rod projecting through said hole, the portion of the fuide rod within the hole when the clamp means is in the first position being smaller in diameter than the hole and.out of contact with the clamp means, and the portions of the guide rod within the hole when the clamp means is in the second position being only slightly smaller in diameter than the hole.
A clamper for a disk player apparatus comprising:
- turntable means for receiving a disc to be played back;
- clamp means for engaging and holding the disc against said turntable means and between said turntable means and said clamp means when said clamp means is in a first position and for permitting the removal of the disc from the turntable means when said clamp means is in a second position;
- support means positioned opposite said turntable means for rotatably and slidably supporting said clamp means, said clamp means being slidable along a direction running from said support means to said turntable means and, when said clamp means is in said first position, said clamp means being mechanically free from said support means;
- permanent magnet means which produces a permanent magnetic force that biases said clamp means toward said second position;
- electromagnetic force means fixed solely to one of said clamp means and said support means for selectively clamping said clamp means against said turntable means;
- and
- means for supplying a current to said electromagnetic means, said current selectively causing the combination of said permanent magnetic means, and said electromagnetic means to generate an electromagentic repelling force which overcomes the force of the permanent magnet means and urges the clamp means toward said turntable means so that the clamp means engages and clamps the disc against said turntable means.
4 more elements
A clamper for a disk player apparatus comprising:
- turntable means for receiving a disc to be played back;
- clamp means for engaging and holding the disc against said turntable means and between said turntable means and said clamp means when said clamp means is in a first position and for permitting the removal of the disc from the turntable means when said clamp means is in a second position;
- support means positioned opposite said turntable means for rotatably and slidably supporting said clamp means, said clamp means being slidable along a direction running from said support means to said turntable means and, when said clamp is in said first position, said clamp means being mechanically free from said support means;
- a first permanent magnet means mounted on one of said clamp means and support means;
- a second permanent magnet means mounted on the other of said clamp means and said support means for combining with said first permanent magnet means to create a permanent magnetic force which biases said clamp means toward said second position;
- electromagnetic means mounted solely on one of said clamp means and support means for selectively clamping said clamp means against said turntable means;
- and
- means for selectively supplying a current to said electromagnetic means, said current causing said electromagnetic means to generate an electromagnetic field that combines with said permanent magnet means to generate an electromagnetic force which overcomes the permanent magnetic biasing force and urges the clamp means toward said turntable means so that the clamp means engages and clamps the disc against the turntable means.
5 more elements
The clamper of 24 further comprising means for sequentially exciting said electromagnetic means to create a rotational magnetic field which rotates the magnet means, clamp means, disc and turntable means when the clamp is in the first position.
A clamper for a disc player apparatus comprising:
- turntable means for receiving a disc to be played back;
- clamp means for engaging and holding the disc against said turntable means and between said turntable means and said clamp means when said clamp means is in a first position and for permitting the removal of the disc from the turntable means when said clamp means is in a second position;
- support means positioned opposite said turntable means for rotatably and slidably supporting said clamp means, said clamp means being slidable along a direction running from said support means to said turntable means and, when said clamp means is in said first position, said clamp means being mechanically free from said support means;
- permanent magnet means mounted on one of said clamp means and support means;
- an electromagnetic coil mounted on the other of said clamp means and support means;
- means for applying an electric current to said electromagnetic coil in one direction to generate an electromagnetic field which in combination with the permanent magnet means produces a force which urges the clamp means to the second position;
- and
- means for applying electric current to said electromagnetic coil in the opposite direction to generate an electromagnetic field which in combination with the permanent magnet means produces a force which urges the clamp means to the first position.
5 more elements
Dependencies are inferred from the claim text.