Apparatus and method for recording and playing back sound

Dynamic information storage or retrieval – Specific detail of information handling portion of system – Mechanical modification or sensing of storage medium

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Reexamination Certificate

active

06185179

ABSTRACT:

The present invention relates to the field of sound recording and play-back apparatus and, more specifically, to the field of acoustic phonographs.
As invented and pioneered by Edison, the phonograph in one form comprises a brass cylinder covered in tinfoil, thin copper plate, or soft iron. Wax was also used for the cylinder. The cylinder is mounted on a threaded rod passing through a female screw fastened to a support fixed to the frame or base of the phonograph. A crank is fixed to the end of the threaded rod. A movable support, which is fixed to the frame, carries a mouthpiece with a membrane or diaphragm. The membrane is acoustically constructed to be relatively acoustically compliant and can be set into vibration. A steel pin, needle, or stylus is mounted on a spring fixed to the base and is coupled to the diaphragm, typically by way of a piece of rubber for movement with the diaphragm as it vibrates under the action of sound waves.
In operation, when one speaks into the mouthpiece of Edison's phonograph, the sounds enter it and cause the compliant membrane to vibrate. This causes the pin to vibrate in a similar manner. To register or record speech, the pin is adjusted to bear lightly on the tinfoil or copper plate by locking the movable support. The cylinder is rotated by the crank and it advances axially by the threaded rod as words are spoken into the mouthpiece. In Edison's phonograph, the cylinder is so constructed as to be relatively acoustically non-compliant or rigid so that it resists the varying pressure of the pin as the pin vibrates under the action of sound waves impinging on the membrane. As a result, the pin presses into the tinfoil or copper plate so as to dig into the surface of the resisting cylinder with a varying force, so that an impression is left on the rotating surface with hills and valleys, or undulations, depending on the vibrations of the pin.
To reproduce the words spoken, the movable support is loosened so that the pin is free of the cylinder, which is then brought back to its starting position. The pin is now set to bear on the cylinder tin or copper plate again with a somewhat lighter force so as to go over the original track it made while recording. The cylinder is rotated and, because the cylinder is acoustically non-compliant, it is the compliant needle which is forced to vibrate in response to the recorded undulations on the cylinder. This causes the diaphragm to vibrate and so to reproduce the recorded sound back through the mouthpiece.
Thus, in Edison's phonograph, the needle or pin in its mounting must be sufficiently compliant to vibrate together with the membrane receiving the sound vibrations. On the other hand, the cylinder must be non-compliant to vibrations so that it can resist the onslaught of the vibrating needle during the process of recording and thereby allow the needle to cut a hill and dale recording groove or track of varying depth corresponding to the recorded sound. During playback, the cylinder must hold firm as the hills and dales in the recording groove force the compliant needle to and fro, recreating the sound vibrations when the needle's vibrations are communicated to the membrane and so to the surrounding air, by way of the horn. Accordingly, the function of the cylinder in Edison's phonograph is to receive and retain the sound groove while recording, and to cause the groove to set the needle vibrating during playback. The horn and the membrane channel the sound vibrations from the air to the needle for recording and back from the needle to the air during playback.
Further background information on the Edison phonograph apparatus may be found in, for example, “Electricity in the Service of Man,” edited by R. Wormell; published by Cassell & Company, New York, pages 752-753; 1886; “The Speaking Telephone,” by George B. Prescott, published by D. Appleton & Company, New York, pages 302-305; 1879; “Elementary Lessons on Sound,” by Dr. W. H. Stone, published by Macmillan and Co., Limited, London; pages 87-90; 1908; and “A Text-book on Sound,” by Edwin H. Barton, published by Macmillan and Co., Limited, London; pages 614-619; 1919.
In accordance with an aspect of the invention, a phonograph comprises an acoustically compliant cylindrical chamber for being set into vibration by impinging sound waves, the chamber having a substantially smooth outer surface and being mounted for axial rotation and for being advanced at a predetermined rate upon the axial rotation; and an acoustically non-compliant stylus, the cylinder wall bearing against the stylus in a spiral path when the cylinder is caused to rotate and advance at the predetermined rate. During recording, the cylinder is caused to vibrate by sound impinging upon it from the surrounding air. The vibrating cylinder wall impales itself upon the non-vibrating stylus so that a recording groove with undulations is formed on the cylinder, also referred to as a “hill and dale” mode of recording. During playback, the cylinder vibrates in response to the recording groove undulations being pressed against the stationary stylus and communicates its vibrations in the form of sound to the surrounding air.
In accordance with another aspect of the invention, a phonograph comprises a rotatable lead screw; a cylinder axially mounted on the lead screw for rotation therewith; and a stylus mounted such that the cylinder bears against the stylus, the stylus being essentially acoustically non-compliant.
In accordance with another aspect of the invention, a phonograph comprises a rotatable lead screw; a cylinder axially mounted on the lead screw for rotation therewith, the cylinder being acoustically compliant; and a stylus mounted for bearing against the cylinder.
In accordance with another aspect of the invention, the cylinder is acoustically compliant.
In accordance with another aspect of the invention, the cylinder is acoustically responsive to sound waves impinging thereupon and vibrates in sympathy therewith.
In accordance with another aspect of the invention, the cylinder is hollow and is made of a material capable of receiving and retaining impressions made by the stylus.
In accordance with another aspect of the invention, the cylinder is made of a plastic material.
In accordance with another aspect of the invention, a surface of the cylinder is lubricated by a lubricant substance such as standard machine lubricating oil.
In accordance with another aspect of the invention, a phonograph includes a controllable force device for urging or biasing the stylus into contact with the cylinder.
In accordance with another aspect of the invention, a phonograph includes controllable bias apparatus for urging the stylus into contact with the cylinder with a force exhibiting a first value sufficient for the stylus to cut a sound recording groove in the cylinder as the cylinder vibrates and exhibiting a second, lesser, value sufficient for setting the cylinder into vibration by the action of the sound recording groove upon the stylus.
In accordance with another aspect of the invention, a phonograph comprises a relatively acoustically compliant cylindrical chamber for being set into vibration by impinging sound waves, the chamber having a substantially smooth outer surface and being mounted for axial rotation and for being advanced at a predetermined rate upon the axial rotation; and a relatively acoustically non-compliant stylus, the outer surface bearing against the stylus so as to trace a spiral path thereupon when the cylinder is caused to rotate and to advance at the predetermined rate.
In accordance with another aspect of the invention, a phonograph comprises a base plate; a pair of supports mounted on the base plate, whereof at least one of the supports includes a screw thread; a threaded rod supported on the supports and engaging the screw thread; a crank coupled to the threaded rod for rotating it; a hollow cylinder mounted concentrically on the threaded rod for rotation therewith, the cylinder being essentially acoustically compliant and susceptible of relativel

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Apparatus and method for recording and playing back sound does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Apparatus and method for recording and playing back sound, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for recording and playing back sound will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2604397

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.