US1803692A - Phonograph attachment - Google Patents

Description

May 5 1931. J BURKE 1,803,692

PHONOGRAPH ATTACHMENT Filed Dec. 14, 1928 Patented May 5, 1931 r PATENT OFFICE ULYSSES ILBURKE, 01" DES MQINES, IOWA .rrionoennrnnirncmvrm Application filed December 14, 1928. Serial No. 326,116.

' This invention relates to improvements in phonographs, and particularly to that part of the phonograph where themechanical vibrations of the stylus are converted into x a sound vibrations, and to the conducting of said sound vibrations to the tone arm of the sound amplifier device.

The object of my invention is to improve the mechanism of a phonograph which con- 'verts the mechanical vibrations of the stylus to soundvibrations, whereby the harshness of the tones .will be greatly modified, and wherebv clear and more distinct tones may be produced. V v o More particularly it is my object to provide in that type of phonographs having a double' sound'box, improved means for transmit ting vibrations from the stylus to the dia- Lphragm's of the sound boxes. n

20 A further object is to provide in that type of a sound boxfor phonogr aphs. having a double diaphragm and a' stylus bar for each of said diaphragms, improved means for connecting the free ends of said. stylus bars, whereby a single needle maybe employed for operating bothof said stylus bars,

and at the: same time cause the stylus bars to be positively actuated by the needle,and to permit free movement of the stylus bars without undesirable noises .due to loose connections, etc. v n I I vMy invention consists in. the construction, arrangement and combination ofrthe various parts of the device,'w hereby the objects contemplated are attained, as hereinafter more fullyset forth, pointed out in my claims. and illustrated in the accompanying drawings, inwhich: I]: j.

1 -Figure 1 is' a side elevation of my-improved "device as applied to a phonograph tone arm. Figure 2 is a detail plan viewofmy improved sound'box, a portion being cut away to show the interior construction.

Figure3- is a detail, sectional view'taken on the line 33 of Figure2r i Q Figure 4 is a detail sectional view taken on the line 44 of Figure 2. v c v The nu eral indicates the tone armiof a jsound. amplifier device of the usual constructhereto in the, usual manner and a stylus bar curing the needles in position.

bending movement between the members and 25. The thin portions 24 are substantion','h'aving at its free enda pair of substan' tially U-shaped sound armsll to which sound boxes 12 are connected. a v V The said sound boxes are spaced apart a slight distance and rigidly supported to each other by means of transversely arranged bars 13, so that the two sound boxes are supported as a single unit. The boxes are supported in a reverse manner so that the diaphragms 14 face each other. The said diaphragms and sound boxes are of the usual construction.

The central portions of thediaphragms are connected by a bar 15 toicause the two diaphragms to operate in unison.

Each of the boxes 12 has a pivot supported 16, said stylus bars being mounted on adjustable plvot members 17 and terminate in socket portions 18. Each of the said socket portions is provided with a set screw 19 forYsev Forconnec-ting both oi? these. sockets 18 with a singlestylus 0r needle, I have provided a yoke bar 20 having an opening 21 for receiving a stylus 22 and a set screw 23 for rigidly securing the stylus therein. The said opening 21 is mounted half way between the ends of the stylus bar. The ends oflthe bar 20 are" tapered, in the manner clearly illustrated in Figure 2,,to'very thin portions 24 which are connected with lugs 25. Each of the lugs 25 has a pin 26 for entering a corresponding socket 18, said pins being secured in position bymeans of the set screws 19.

It will be seen by referring to Figure 2 that the yoke bar 20 is heavily constructed, and that the members25 are also comparatively heavy, to provide a rigid support for the pins 26. 'The members 20 and 25 .are connected with very thin portions 24 to permit a slight tially in a line extendinglongitudinally of the member 20,]and' passing through the stylus 22 so that thecomparativelyheavy body portions of the members 20 and 25 are connected by the thin and flexible portion 24, in such a manner that motion from the member 20 ."will be positively imparted to the members 25, and at the same time permit a free bending movement between said body members.

By placing the thin portion 24 in a longitudinal line through the needle 22, it will be seen that bending movement of the member as may be permitted, and at the same time movement positively transmitted to the members 25 and 26. The material forming the socket members 18, the pins 26 and the members 25 should be considered a lever arm for actuating the stylus bar 16, said lever arm terminating the point 24 which is constantly under a bending strain, while the stylus is being operated, as the movement of the said stylus is longitudinally of the bar 20. The metal of the bar 20 should be considered as a connecting link which is under tensile and compression strains.

It is, therefore, quite important that the thin portion connecting the members 20 an d 25 be located substantially in a line extending through the stylus 22, as before described. The thin portion 24 acts as a pivot connection between said pivot members. I have found, however, that pivot connections at this point are very undesirable, due to the fact that the tone properties and qualities produced through the movement of the stylus 22 will be greatly modified by said pivot connection, where two independent and separate pieces of material are connected by a third pivot member or pin. From a practical standpoint, it is almost impossible to pivotally connect these members without more or less undesirable noises and rattling.

It will be seen that if the stylus 22 is placed on a record with its point in the groove of the record, and the record rotated, then the point of the stylus will be oscillated transversely or longitudinally of the bar 20, and the longitudinal movement imparted to said bar-'20, which in turn will cause the lever device, comprising the socket 18, the bar 26 and the member 25, to oscillate transversely, and in turn longitudinal movement imparted to the bar 15, which will cause the diaphragms 14- to be vibrated in unison. One of the diaphragms is moved inwardly while the other is' moved outwardly, thereby producing tones of some what lighter volume than those produced by the ordinary single diaphragm, the tones of which are very clear and of a high quality representing more closely the natural tones of the original instrument or voice. In actual practice one of the tone arms 11 is considerably longer than the other to preventthe sound waves of one arm neutralizing the sound waves of the other arm.

I have found by actual experiment that various tone qualities may be obtained by forming the yoke bar 20 of various kinds of metal. The tone qualities may also be somewhat varied by varying the thickness of the portions 24, which will necessarily depend largely upon the kind of material used in the body members 20 and 25.

Thus it will be seen that I have provided an attachment for phonographs, which is comparatively inexpensive to manufacture, inasmuch as the standard parts of the sound box are utilized in my construction. The device when constructed may be used to get a large number of tone efiects with a very small change in the apparatus, and when used as illustrated in Figures 1 and 2, will produce a clear tone of high quality.

I claim as my invention:

1. A phonograph attachment comprising a tone arm, a pair of sound boxes spaced apart and parallel with each other with their diaphragms innermost, said sound boxes communicating with said tone arm, each of said sound boxes being provided with a stylus bar, a bar connecting the central portions of the diaphragms, and the inner ends of said stylus bars being connected to the bar, each of said stylus bars being provided with a clamping device having a clamping socket, a stylus yoke having a bar, laterally extending end portions and flexible portions connecting said bar and said end portions, a pin for each of said end portions for entering the clamping sockets of said stylus bars, and a stylus supported in the central portion of said yoke.

2. A phonograph attachment comprisinga tone arm, a pair of sound boxes spaced apart and parallel with each other with their diaphragms innermost, said sound boxes communicating with said tone arm, each of said sound boxes being provided .with a stylus bar, a bar connecting the central portions of the diaphragms, and the inner ends of said stylus bars being connected to the bar, each of said stylus bars being provided with a clamping device having a clamping socket, a stylus yoke having a bar, laterally extending end portions and flexible portions connecting said bar and said end portions, a pin for each of said end portions for entering the clamping sockets of said stylus bars, and a stylus supported in the central portion of said yoke, the thin portion of said yoke being substantially in a line. extending longitudinally of said yoke and extending through. said stylus.

3. A phonograph attachment comprising a tone arm, a pair of sound boxes spaced apart and parallel with each other with their diaphragms innermost, each of said sound boxes being provided with a stylus bar, a bar connecting the central portions of the diaphragms, the inner ends of said stylus bars being connected to the bar, each of said stylus bars being provided with a clamping device having a socket, a stylus yoke having a bar, laterally extending end portions and flexible portions connecting said bar and said end portions, a pin for each of saidend portions for entering the clamping sockets of said stylus bar, and a stylus supported in the central portion of said yoke.

4. A phonograph attachment comprising a stylus yoke having a bar and laterally extending end portions and flexible portions connecting said bar and said end portions, a connecting pin for each ofsaid end portions mounted perpendicular to said bar, said yoke having a clamping device in its central portion for receiving a stylus. s s

5. A phonograph attachment comprising a stylus yoke having a bar, laterally extending end portions adapted to be secured to the stylus bars of a double phonograph unit, thin portions connecting the bar and the end portions, and a clamping device in the central portion of the yoke for receiving a stylus.

6. A phonograph attachment comprising a yoke bar terminating at each end in laterally extending port-ions, the nnctions of said laterally extending portions and said bar being comparatively thin, the free ends of said laterally extending portions terminating in pins, and a stylus in the central portion of said bar.

Des Moines, Iowa, December 4, 1928. vULYSSES J. BURKE.

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