Phonograph
AssigneeCranfield Institute of Technology
InventorsJack Dinsdale, David W. Parkins, John P. Hardwick
Life of this patent
Estimating the term…
Abstract
A phonograph has a viscous damping arrangement coupling a pick-up arm to the base of the phonograph to damp vertical and horizontal vibrations of the arm. The damping means is coupled to the arm at a position close to the pick-up cartridge of the arm. A counter-balance mass is also provided on the arm, the mass having an adjustable position and mass.
Claims14
A phonograph record disc player comprising:
- a support;
- a bearing arrangement fixedly coupled to the support;
- a pick-up arm mounted on the bearing arrangement or horizontal and vertical movement on the record disc and having carrying means for attaching a pick-up cartridge to the arm;
- first damping means secured to the carry means at a position nearer the carrying means than the bearing arrangement;
- and
- second damping means overlying said disc having means for securing the second damping means to the support, said first and second damping means cooperating to provide damping between the carrying means and the support, for damping a range of frequencies of vertical and horizontal vibrations of the carrying means, whilst allowing free movement over warps and eccentricities of the record disc, thereby to provide relatively low damping for frequencies below 5 Hz, moderate damping between 5 Hz and 20 Hz, and relatively high damping for frequencies above 20 Hz.
In a phonograph record disc player including a support, a bearing arrangement fixedly mounted on said support, a pick-up arm mounted on said bearing arrangement for horizontal and vertical movement over said record disc and having a carrying means for attaching a record player pick-up cartridge to said arm, and a damping arrangement for providing damping between said carrying means and said support, the improvement comprising said damping arrangement including first damping means secured to said carrying means at a position nearer said carrying means than said bearing arrangement, and second damping means having means for securing said second damping means to said support, said first damping means comprising a paddle and said second damping means comprising a trough rigidly fixable to said support for containing viscous fluid in which said paddle move, said through overlying said record disc said first and second damping means cooperating to provide damping between said carrying means and said support for damping a range of frequencies of vertical and horizontal vibrations of the carrying means, whilst allowing free movement over warps and eccentricities of the record disc, thereby to provide relatively low damping for frequencies below 5 Hz, moderate damping between 5 Hz and 20 Hz, and relatively high damping for frequencies above 20 Hz.
Dependencies are inferred from the claim text.