US1633624A - Phonograph tone arm and resonator - Google Patents

Description

June 28,1927.- 1,533,624

vy. T CARNES PHONQGRAPH TQNE ARM AND RESONATOR Filed Dec. 19, 1923 ran-ED STATES A Fatented June 28, 1927.

WILLIAM nonn vns, or KAnsAs CITY, MIssoUBI, Assreivonmo' onnnns ARTIFICIAL .ULIMB COMEANY,- or KANSAS CITY, ivrrssounr.

' rz'ronoennrn TONE AR Ann nnsorm'ron.

Application filed December 19, 1923. Serial No. 681,512.

My invention relates to. phonographs and particularly to. the tone arm and amplifier thereof.

The object of this invention is to provide a tonearm which is swivelled on the upper end of the amplifier and will have no joints and restricted portions between said swivel and the sound box. Also to form said tone arm on the lines of a parabola, gradually increasing in diameter from the free end there of to said swivel. Also to form the small end of the amplifier onthe lines of a parabola, thus eliminating the right angle elbow curves in said tone arm and amplifier. Also to provide a hinge-swivel joint between the tone arm and amplifier.

These and other features of invention will appear hereinafter and are illustrated in the accompanyingdrawings, in which": i Figure 1 is a side elevation of my improved tone arm and amplifier.

Figure 2 is a: vertical section of my improved"hinge-swivel joint on-the line 22.

Figure 3 is a transverse section of the same on the line 33 in Fig. 1.

Figure 4 is a side elevation of the swivel ring of my invention.

Figure 5 is a plan View of the same.

Figure 6 is a rear View of the lower end of the bar G.

In these drawings, A indicates my improved tone arm, A indicates a sound-box, and B indicates my improved amplifier; B is the curved neck of the amplifier B which joins the tone arm A.

I have eliminated'the usual sharp curve of a right angle elbow, and in lieu thereof my improved tone arm A is formed with the gradual curve of a parabola from the free end a to the swivel end a, the diameter there of gradually increasing from the end a to the end a of the tone arm, thus eliminating, as far as possible, interior pockets wherein there is little or no longitudinal progress of tone waves within the tone arm A.

Within the free end a of the tone arm A is inserted the neck a of the sound-box A, which is secured therein by means of a set screw a This sound-box, shown in the accompanying drawings, is the subject of a separate application and forms no part of this invention. I

The resonator B is provided with an up turned neck B, which like the tone arm A is formed with parabolic curves, thus reducing the sharp curves of aright-angle elbow, so that the natural expansion of sound waves is not interfermredwith.

On the upper end of the neck B, I place a spider-ring, C, which 'is secured firmly. in place by means of bolts C which pass through ears 6, on'opposite sides of the neck B and screw into ears 0 on opposite sides of the spider-ring C. r From the hub of the spider-ring, an upright post D projects upwardly, and upon this post D anotherspider ring E is journalled, the hub E of the ring E is tubular and extends above the upper endof the post D. I

Upon the upper end of the post D, I place aball, e, and within the upper end of the hub tube E is placcd an adjusting screw F which carries the ring E free from the spider-ringC. In the upper edge of the'ri'ng E are found slots 0 e" at opposite sides or said ring whiclrrece-ive studs f f riveted in diametrically opposite sides of the wall of the tone arm, which permits a vertical swing of the tone arm with relation to the ring E, while the ring E will freely turn on the post D. I

Riveted or otherwise secured to the tone arm A is a bar G which extends downwardly to a point opposite the rear of the amplifier B. The lower end of the bar G is provided with a slit- 9, and a clip G is pressed over the lower end of said bar G being retained thereon by the friction of said clip on the bar, enhanced by the elasticity of thesplit end of said bar.

Secured to the frame H of the machine is a bracket H which projects forwardly to the line of the axis of the swivel post D, and secured to the clip G on the bar G is a cable H which is also secured in the bracket H and which serves to suspend the the receiving end thereof, an upright post supported upon said ring, a swivel ring journalled on said post, means to give Vertical adjustment to said ring with relation to said post, said ring having vertical slots in its' upper edge at diametrically opposite points along the upper edge of its periphery, a tone arm adapted to receive said ring, and trunnion studs secured in the wall of said arm and adapted to enter said slots.

2. In an apparatus of the class described, an amplifier, a'spider ring secured on the receiving end thereof, an upright swivel post supported on said ring, a swivel ring having a tubular hub and having vertical notches in the upper edge thereof and having said tubular hub journalled on said upright post, an adjusting screw in the upper end of said tubular hub adapted to support said swivel ring free from said spider ring, a tone arm adapted to receive said swivel ring, trunnion posts secured in the wall of said tone arm and entering said vertical slots, and means to limit the downward swing of said tone arm on said trunnion posts.

8. In an apparatus of the class described, an amplifier, a tubular swivel on the upper end thereof, and a'tapered, parabolic, tone arm having the base thereof trunnioned on said swivel.

4;. In an apparatus of the class described, an amplifier, a tubular swivel on the upper end thereof, a curvedtone armtrunnioned on said swivel, and means to support the free end of said tone arm.

5. In an apparatus of the class de'seribed, a tubular swivel ring having oppositely disposed trunnion receiving slots in the upper edge thereof, a curved tone arm, trunnion posts on saidtone arm adapted to rest in said slots, a downwardly extending arm secured to the rear of the said tone arm, a case to enclose the said apparatus, and means to anchor the lower end of said arm to said case of said tone arm.

6. In an apparatus of the class described, an amplifier, a spider ring secured on the receiving end thereof, a swivel post extending upwardly from said ring, a swivel ring having notches extending downwardly in diametrically opposite points of the upper edge thereof, a tubular hub connected to said ring and journalled on said post, a screw in the upper end of said tubular hub adapted to support said swivel ring out of contact with said spider ring, a tone arm adapted to receive said swivel ring, trunnion studs on the inner surface of said tone arm adapted to be lowered into said notches in the upper edge of said swivel ring, and an arm secured on. said tone arm and extending downwardly to anchor the lower end of said tone arm.

In testimony whereof I aflix my signature.

IVILLIAM T. CARNES.

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