Viscous damped pivot system for a phonograph tone arm

Claim 2

In a sound reproducing device: a support; a turntable arranged on said support for carrying a record member; means for rotating said turntable and said record member; a stylus-carrying tone arm for reproducing sound from the sound grooves of said record member; said tone arm having a pivotally supported end; a bearing element connected to said support and journaled to said end of said tone arm for pivotally supporting rotational movement of said arm about a horizontal axis; a viscous damping fluid disposed in a channel formed within said element; a drag element disposed adjacent said bearing element and in continuous frictional engagement with the viscous damping fluid contained in said channel formed within said bearing element; said drag element being rotatable with respect to said bearing element; and operating means affixed to the supported end of said tone arm for engaging and rotating said drag element relative to said bearing element in response to pivotal movement of said tone arm about its horizontal axis, thereby to damp the rotational movement of said tone arm about its horizontal axis; said operating means being disconnected from said drag element when said stylus-carrying tone arm is engaged with said record member, thereby to permit free vertical rotation of the arm when it is reproducing sound from the grooves of said record member.

Claim 3

The reproducing device of claim 1 including a spring connected to said drag element to rotate said drag element out of engagement with the operating means of the tone arm after said tone arm has been rotated downwardly so that its stylus impinges upon a record.

Claim 4

In a sound reproducing device: a sUpport; a turntable arranged on said support for carrying a record member; means for rotating said turntable and said record member; a stylus-carrying tone arm for reproducing sound from the sound grooves of said record member; said tone arm having a pivotally supported end; a bearing element journaled to said end of said tone arm for pivotally supporting rotational movement of said arm about a horizontal axis; said bearing element having a vertically extensive surface with a recess formed therein; a viscous damping fluid disposed in said recess; a drag element rotatably supported on said bearing element and having a vertically extensive surface in continuous frictional engagement with the viscous damping fluid disposed in the recess of said bearing element; means for limiting movement of said drag element relative to said bearing element; and operating means affixed to the supported end of said tone arm for engaging and rotating said drag element relative to said bearing element in response to pivotal movement of said tone arm about its horizontal axis, thereby to damp the rotational movement of said tone arm about its horizontal axis; said operating means being disconnected from said drag element when said stylus-carrying tone arm is engaged with said record member, thereby to permit free vertical rotation of the arm when it is reproducing sound from the grooves of said record member.

Claim 5

In a sound reproducing device: a sUpport; a turntable arranged on said support for carrying a record member; means for rotating said turntable and said record member; a stylus-carrying tone arm for reproducing sound from the sound grooves of said record member; said tone arm having a pivotally supported end; a bearing element journaled to said end of said tone arm for pivotally supporting rotational movement of said arm about a horizontal axis; said bearing element having a vertically extensive surface with a recess formed therein; a viscous damping fluid disposed in said recess; a drag element rotatably supported on said bearing element and having a vertically extensive surface in continuous frictional engagement with the viscous damping fluid disposed in the recess of said bearing element; means for limiting movement of said drag element relative to said bearing element; and operating means affixed to the supported end of said tone arm for engaging and rotating said drag element relative to said bearing element in response to pivotal movement of said tone arm about its horizontal axis, thereby to damp the rotational movement of said tone arm about its horizontal axis; said operating means being disconnected from said drag element when said stylus-carrying tone arm is engaged with said record member, thereby to permit free vertical rotation of the arm when it is reproducing sound from the grooves of said record member.

Claim 6

The reproducing device of claim 3 including a spring coupled between said support and said drag element to rotate said drag element out of engagement with the operating means of the tone arm after said tone arm has been rotated downwardly so that its stylus impinges upon a record.

Claim 7

The reproducing device of claim 4 wherein said bearing element has a stop located thereon, and said drag element has a cutout section formed thereon, said stop of said bearing element being located in said cutout section of said drag element so that movement of said drag element with respect to said bearing element is limited by engagement of ends of the cutout section with said stop.

Claim 8

The reproducing device of claim 4 wherein said bearing element has a disc-shaped portion, and a hub portion disposed on each side of said disc-shaped portion, each of said hub portions being pivotally connected to the supported end of said tone arm.

Claim 9

The reproducing device of claim 6 wherein said recess is of annular configuration and situated on one side of the disc-shaped portion of said bearing element, and said drag element is disc-shaped and contains a central aperture for receiving the hub portion located on the same side of said bearing element as said recess so as to be rotatable about said hub portion, said device including fastening means abutting said spring and causing said spring to urge said drag element into continuous frictional engagement with said viscous damping fluid contained in said recess.

Claim 10

In a sound reproducing device: a support; a turntable arranged on said support for carrying a record member; means for rotating said turntable and said record member; a stylus-carrying tone arm for reproducing sound from the sound grooves of said record member; said tone arm having a pivotally supported end; a first disc-shaped element journaled to said end of said tone arm for pivotally supporting rotational movement of said arm about a horizontal axis; said first element having a vertically extensive surface with a recess formed therein; a viscous damping fluid disposed in said recess; a second disc-shaped element rotatably supported on said first element and having a vertically extensive surface in continuous frictional engagement with the viscous damping fluid disposed in the recess of said first element; said second element having a radial projection formed thereon; means for limiting movement of said second element relative to said first element; and a pair of spaced-apart driving surfAces affixed to the supported end of said tone arm; said radial projection of said second element being located between said driving surfaces and engageable by one or the other of said driving surfaces for rotating said second element relative to said first element in response to pivotal movement of said tone arm about its horizontal axis, thereby to damp the rotational movement of said tone arm about its horizontal axis; said spaced-apart surfaces being each disengaged from said radial projection when said stylus-carrying tone arm is engaged with said record member, thereby to permit free vertical rotation of the arm when it is reproducing sound from the grooves of said record member.

Claim 11

In a sound reproducing device: a support; a turntable arranged on said support for carrying a record member; means for rotating said turntable and said record member; a stylus-carrying tone arm for reproducing sound from the sound grooves of said record member; said tone arm having a pivotally supported end; a first disc-shaped element journaled to said end of said tone arm for pivotally supporting rotational movement of said arm about a horizontal axis; said first element having a vertically extensive surface with a recess formed therein; a viscous damping fluid disposed in said recess; a second disc-shaped element rotatably supported on said first element and having a vertically extensive surface in continuous frictional engagement with the viscous damping fluid disposed in the recess of said first element; said second element having a radial projection formed thereon; means for limiting movement of said second element relative to said first element; and a pair of spaced-apart driving surfAces affixed to the supported end of said tone arm; said radial projection of said second element being located between said driving surfaces and engageable by one or the other of said driving surfaces for rotating said second element relative to said first element in response to pivotal movement of said tone arm about its horizontal axis, thereby to damp the rotational movement of said tone arm about its horizontal axis; said spaced-apart surfaces being each disengaged from said radial projection when said stylus-carrying tone arm is engaged with said record member, thereby to permit free vertical rotation of the arm when it is reproducing sound from the grooves of said record member.

Claim 12

The sound-reproducing device of claim 8 wherein the operating means comprises a pair of opposed adjustable screws mounted on the supported end of the tone arm, and the drag element includes a radially protruding portion disposed between the screws, the inner end of one of said screws being located on the supported end of the tone arm to engage one side of the protruding portion of the drag element for rotation of said drag element in one direction with respect to said bearing element during movement of said tone arm from a position raised substantially above said record member toward a position on said record member, the inner end of the other of said two screws being located on the supported end of the tone arm to engage the other side of the protruding portion of the drag element for rotation of the drag element in an opposite direction with respect to said bearing element during movement of said tone arm from a position on said record member to a position raised substantially above said record member.

Claim 13

The sound-reproducing device of claim 8 wherein each of said driving surfaces is adjustably positioned in the supported end of the tone arm.