US1709391A - Reproducer for phonographs and the like - Google Patents

Description

April 16, 1929.

C. H. DAVIS REPRODUCER FOR PHONOGRAPHS AND THE LIKE Filed March 31, 1926 Patented Apr. 16, 1929.

UNITED STATES 1,709,391 PATENT OFF-ICE.

CLAUDE HUDSON DAVIS, Q]? MOSMAN, AUSTRALIA, ASSIGNOR TO THE RESONATOR LIMITED,OF SYDNEY, .NEW SOUTH WALES, A COMPANY OF NEW SOUTH WALES.

nnraonncnaron rnoivoeaarris AND THE LIKE.

Application filed March 31, 1926, Serial No. 98,780, and in Australia May 4, 1925.

The invention is for use with phonograph disc records and theusual mechanism for rotating same and provides a reproducer of simple construction, having acoustical qualities of high perfection.

According hereto a light sonorous chest (herein termed amplifier) made of thin sheet material bent or moulded into shape preferably conical, is carried at its larger end within a ring which hasa holder for an ordinary. phonograph needle. The ring has hinge connection to a spindle turning on a vertical axis whereby freedom of movement in vertical and horizontal planes is permitted as the needle follows the sound groove in the record.

Referring to the drawing Fig. 1 is a front elevation partly in tion.

Fig. 2 is a side sectional elevation. 4 Fig. 3 is a cross sectional elevation of a detail. j

Fig. 4 is a front elevation partly in section.

Fig. 5 isa plan of a detail. Fig. 6 is a plan of Fig. 1. First referring more particularly to Figs.

1,2 and 3. The conical amplifier 1, of thin Wood is carried-at its larger end within a channel, 2, in the cane ring 3, being held in position by a series of cork or wooden bridge pieces, 4, located at intervals around thefiring and glued thereto and to the amli er.

p The phonograph needle, 5, is' secured with in the socket, 6 of the needle holder 7 by a set screw 8 the rear end of the needle holder 7 being provided with a screw threaded tapered end to enable it to be screwed into a wooden block 9 that is glued to the periphery of the ring 3.

The reproducer 1s supported by means of a pillar 10 having a socket 19 to receive a spindle 20 having a shoulder 21 and a jaw 4 22 to receive a specially shaped bracket 23 which is provided with a jaw 24 wherein a portion of ring 3 may lie and be firmly secured by screws 25 that pass through perforations 26 in the side members of the jaw 24 and the corresponding holes in the ring 3. The bracket 23 is pivoted in the 'jaw 22 by the pin 27 to provide freedom of movement in a vertical plane and to enable the reproducer to be swung over when it is desired to renew the needle. Stops 28 on the curved extension 32 of the bracket contact with the side-of the jaw 22 when the reproducer has been moved sufliciently to bring the preponderance of its Weight upon that side of the pivot 27. The position of the bracket 23 when the reproducer is in an inoperative-position is shown by dotted lines at Figure 4.

The lower end of the pillar 10 is provided with a key 11, screwed centrally into the bottom end thereof, and projecting s'ufliciently to enable it to be passed through a central key-way 12 formed in a metal plate or disc 13 securely fastened to the upper horizontal member 14: of the cabinet 15 by screws 16, a recess 17 being cut in the mem ber 14 to receive the key 11 and allow it to be turned therein. .Stops 18 are formed upon the under side of the plate 13 in order to limit the movement of the key, and with it the pillar 10, when it has been inserted in the key way 12.

It has been found that the most suitable location for the pillar 10 is such that when the reproducer is swung through an are 0 which passes through the pivot 29 the needle will traverse the arc (see dotted lines Fig. 6) almost to the pivot 29.by which said disc record 30 is retained in position upon'the driven platform 31.

Hitherto the various methods adopted for reproducing sound in phonographs have all followed the principle of forming a connection between the needle or stylusand the centre or a point near the centreof a diaphragm and, in many cases, a tone arm has been provided for the purpose of conveying sound, produced by the vibrations of the diaphragm, transmitted thereto from the needle or stylus, to an amplifying horn or chamber. My invention differs from these methods in that the vibrations are first transmitted from the phonograph needle to a ring and from thence to an amplifier. Without departing from the spirit'thereof my invention may be carried into effect in a variety of ways and a number ofdifferent materials may be used.

. Although the amplifier has been shown conical, and that shape is preferred, experiments have proved that it need not be confined to that particular shape for instance it spherical or other hollow shapes. It should also be noted that whilst the method herein described and illustrated in the drawings for securing the peripheral edge of the amplifier to give excellent results of other methods for example, pensed with there are a number that could be employed, the bridge pieces could be disand the convex face of the amplifier glued to the adjacent edge of the ring around the channel and a length of cane packed and glued between the concave face of the amplifier and the adjacent side of the channel.

I claim 1. An acoustic device including an amplifier, a ring having a channel which receives the peripheral edge of said amplifier, and a needle holder carried by the peripheral edge of the ring and constructed to receive a needle for transmitting sound vibrations to the ring.

2. An acoustic device comprising a conical amplifier, a ring having a channel wherein the peripheral edge of the amplifier may freely lie, bridge pieces interposed between the amplifier and the adjacent edge of the channel of the ring such bridge pieces being glued to the amplifier and to the ring, and a needle holder secured to the ring and constructed to receive a needle whereby Within the channel has been found and contructed to receive sound vibrations are transmitted from a disc record.

3. An acoustic device comprising a conical amplifier, a ring having a channel which receives the peripheral edge of the amplifier, a needle holder secured to the ring a needle whereby sound vibrations are transmitted from a disc record, and means for mounting so that the reproducer and the ring may rise and fall and also move in an arc across the face of the disc record.

at. An acoustic device as claimed in claim 3, wherein the means for mounting the ring consists of a recessed pillar, a spindle ha ving a bifurcated projection swivelled therein, and an attaching bracket pivoted in the upper end of the spindle and attaelual to the ring, substantially as and for the purposes set forth.

5. An acoustic device including in combiuation a ring having a groove. on its inner circumference, an amplifier the outer periphery whcreof being located in said groove, means for mounting the outer periphery of the amplifier within the groove, and a needle holder secured to and connected solely to said ring.

In Witness whereof I have signed this specification.

CLAUDE HUDSON DAVIS.

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