Direct drive for turntables
AssigneeKollmorgen Technologies Corporation
InventorFrank Arnold, Jr.
Life of this patent
Estimating the term…
Abstract
An improved direct drive for turntables having a disk-shaped armature integrally coupled to the turntable and concentrically arranged about the shaft of the turntable for causing rotation of the turntable during the application of current to the disk-shaped armature. Advantageously, when such an arrangement is used with audio turntables a disk changer mechanism can be readily accommodated in the turntable.
Claims11
A direct drive for turntables of the type having a platter coupled to a shaft for rotation of the platter relative to the deck of the turntable, wherein the improvement comprises:
- a disk-shaped armature having a plurality of insulated layers of windings thereon and concentrically arranged about the shaft and fixedly coupled to the platter;
- flux return means fixedly coupled to said platter between said disk-shaped armature and said platter;
- magnet means fixedly coupled to the deck for providing magnetic flux to said disk-shaped armature and said flux return means;
- brushes spaced from said magnet means and fixedly coupled to the deck and arranged for continuous contact with said disk-shaped armature so that when current is applied to said brushes a circuit is completed through said disk-shaped armature with the current in said disk-shaped armature coacting with the magnetic flux from said magnet means to apply rotational forces to said disk-shaped armature for rotating the platter coupled thereto;
- and
- an inertia means coupled between said flux return means and the platter for increasing the inertia of the platter.
A direct drive for turntables of the type having a platter coupled to a shaft for rotation of the platter relative to its deck, wherein the improvement comprises:
- a disk-shaped armature concentrically arranged about the shaft and fixedly coupled to the platter, said disk-shaped armature being bonded at its upper surface to a magnetic flux return ring fixed on said platter, said armature including a plurality of insulated layers of windings;
- a ring magnet concentrically arranged about the shaft and fixedly coupled to the deck, said ring magnet being spaced from said disk-shaped armature for providing magnetic flux to said disk-shaped armature and said magnetic flux return ring;
- a pair of brushes surrounded by said ring magnet and fixedly coupled to the deck, said brushes being positioned with said disk-shaped armature for continuous engagement with said disk-shaped armature so that when current is applied to said brushes a circuit is completed through said disk-shaped armature with the current in said disk-shaped armature coacting with the magnetic flux from said ring magnet to apply rotational forces to said disk-shaped armature for rotating the platter coupled thereto;
- and
- an inertia means coupled between said flux return ring and the platter for increasing the inertia of the platter.
Dependencies are inferred from the claim text.