The talking machine world (Jan-Dec 1913)

52 "T THE TALKING MACHINE WORLD. LATEST PATENTS RELATING TO TALKING MACHINES AND RECORDS (Special to The Talking Machine World.) Washington, D. C, December 8. — Acoustical Instrument. Louis Lumiere, Lyon, France, assignor to The Victor Talking Machine Co., Camden, N. J. Patent No. 1,077,536. This invention relates to improvements in acoustical instruments such as telephones, microphones, stethoscopes, talking machines, musical instruments, and in general any instrument used for the reception or transmission of sounds. The invention consists in a certain construction of sound box for such instruments, and its essential features are an extensible chamber with a stationary wall, a movable wall adapted to be reciprocated toward and away from the stationary wall, and means between the two walls for preventing the escape of air between them but allowing perfect freedom of the movable wall to move in unchanged form and to any extent that may be practically required. According to this invention a sound box for acoustical instruments is obtained comprising a stationary wall, having an opening therein for the passage of the sound waves, a movable wall adapted to be reciprocated toward and away from the stationary wall, and means between the edges of the movable wall and the stationary wall to prevent the escape of air between them, such means however, leaving the movable wall free to move as a whole in substantially unchanged form to any extent that may practically be required, and offering substantially no resistance to the movement of the movable wall whatever the position of the latter with regard to the stationary wall, so that the position and movement of the movable wall is regulated entirely by the sound waves or means through which the movable wall is reciprocated. Further, according to this invention the whole of one side of the extensible chamber moves, and not merely the central portion thereof, thus producing a more effective reproduction. Fig. 1 is a sectional elevational view of one construction of sound box embodying this invention ; Fig. 2 is an end view of the movable member shown in Fig. 1, and Fig. 3 is an end elevational view of a modified form of the movable member stiffened by suitable corrugations. Phonographic Recording or Reproducing Apparatus. Thomas A. Edison, Llewellyn Park, Orange, N. J., assignor to New Jersey Patent Co., West Orange, N. J. Patent No. 1,078,264. This invention relates to improvements in recording or reproducing apparatus for phonographs or other talking machines, but the improvements are particularly directed to reproducing apparatus. With phonographic reproducing apparatus as now made, the diaphragm, which is rigidly clamped at its periphery, comprises a single disc corrugated so as to be as stiff as possible, or a series of discs of gradually reduced diameters. With such a diaphragm the limit of amplitude is comparatively slight, since in vibrating to one side or the other of the medial line the diaphragm is not only flexed, but it undergoes stretching and contraction as it recedes from or approaches the medial line. Fur thermore, the resistance of the diaphragm to the vibrating effect enormously increases as the diaphragm is distorted out of its normal plane. For these reasons any attempts to increase the loudness of phonographic reproduction by increasing the amplitude have been unsuccessful, for the reason that to materially increase the amplitude of vibration would impose an enormous increase in the wear of the record surface. Furthermore, it is found that even under existing conditions, where floating weights are used that are as heavy as can be employed without imposing objectionable wear on the record, the weight itself is more or less responsive to the vibrations and particularly vibrations representative of tones of low pitch, so that the weight vibrates under the effect of such tones and correspondingly detracts from the reproduction obtained from the diaphragm itself. Consequently phonographic reproductions, particularly of a piano, are characterized by a slurring of the bass notes. The object of the invention is to provide an improved phonographic apparatus, particularly for reproducing purposes, in which the means for setting up vibrations in a static column of air is susceptible of vibrations of relatively enormous amplitude and wherein the power necessary to effect such vibrations remains practically constant throughout the entire movement. A further object is to provide a recording or reproducing apparatus in which a compensating weight may be used of great mass, so as to be unresponsive to any of the vibrations of the record but maintaining the stylus in correct relation to the surface regardless of mechanical variations or eccentricities therein, and at the same time the said weight, notwithstanding its great mass, will not impose any undue wear on the waxlike material. To this end the invention consists, in a broad sense, of employing as a means for setting up vibrations in a static column of air a vibrating piston instead of a diaphragm, the piston fitting very closely but not touching the bore of the casing in which it operates, connected to the stylus so that the two will move in unison, and combined with suitable elastic tension devices for maintaining the stylus in proper engagement with the recording surface or the record as the case may be. Such a vibrating piston is made as light as possible so as to reduce momentum and inertia to a minimum, and it is therefore preferably formed of thin sheet aluminum or magnesium (preferably the latter) having a depending flange, with its body formed with concentric corrugations and preferably provided with radial ribs, so as to be as stiff as possible. The inventor with these devices contemplates using a compensating weight of greater mass than is customary, which is supported on the record itself preferably by an anti-friction roller, and the stylus lever is pivoted to this weight in such position that the stylus will be in line with that part of the weight that bears on the record, such as the roller referred to, so that, the desired relation of the stylus and the weight will be always maintained. Fig. 1 is a sectional view of a reproducing apparatus embodying the present improvements in their preferred form, and showing the use of a compensating weight; Fig. 2 is a bottom view of the same; Fig. 3 is an enlarged detail view showing the compensating weight and the connection with the stylus lever; Fig. 4 is an enlarged detail view showing the adjustment for the tension mechanism; Fig. 5 is a cross sectional view similar to Fig. 1, showing the apparatus without the compensating weight, as it may be used if the records are sufficiently true; Fig. 6 is an enlarged view showing the construction of diaphragm, and Fig. 7 is a bottom view of the diaphragm. Sound-Box. Thomas A. Edison, Llewellyn Park, Orange, N. J., assignor to the New Jersey Patent Co., West Orange. N. J. Patent No. 1,078,266. This invention relates to sound boxes particularly of the type adaoted for use in connection with disk records having vertically undulating grooves, although its use is not limited to that type, as it may be applied for lateral cut records. In order to hold the reproducing stylus into firm engagement with the record, it has heretofore been customary to weight the casing or support for the diaphragm. It has been found that by weighting the diaphragm and distributing the weight uniformly over the same, a better quality of reproduction is obtained than when all the weight comes to the diaphragm through the diaphragm support, the strain in the latter case, being substantially all transmitted to the diaphragm over a small area above the reproducing stylus, whereas with the improved construction, a large part of the strain is distributed uniformly over substantially the whole diaphragm. The principal object of this invention is to provide an improved diaphragm weighted as described above. In a general way this invention resembles that disclosed in Letters Patent of the United States No. 676,225, granted to Mr. Edison on June 11, 1901, wherein is described a recorder provided with a movable weight having in its lower end a rubber insert which bears upon the center of the diaphragm to counteract the upward stress exerted upon the diaphragm by the engagement of the cutting or engraving tool with the record material. The present invention, however, refers more particularly to reproducers and is furthermore an improvement on that described in the above named patent in that the strain over the diaphragm is distributed by weighting the same at a plurality of points uniformly over the surface thereof. Another object of this invention is to provide a diaphragm rigidly secured to its support and having a recess for permitting flexing adjacent the periphery of the diaphragm so as to permit a free bodily movement of the latter. Fig. 1 is a central vertical section taken on the line 1 — 1 of Fig. 2 of a reproducer provided with a diaphragm embodying the invention. Fig. 2 is a bottom plan view thereof; Fig. 3 is a cross section of a diaphragm illustrating preferred means of weighting the same; and Figs. 4 and 5 are similar views of modifications thereof. Automatic Stop Mechanism for Gramophones. Minard Arthur Possons, Cleveland, O. Patent No. 1,078,460. This invention relates to improvements in automatic stop mechanism for gramophones, and the object is to provide means for automatically lifting the needle from the record and stopping the machine when the record has been played and pertains particularly to an attachment which can be readily attached to the ordinary reproducer now in use without changing any part thereof. The only addition of the gramophone is the placing of a small projection on the record. In the accompanying drawings, Fig. 1 is a side elevation of the ordinary reproducer showing this attachment applied and in the position when the reproducer is supported by the needle on the record.