US2085582A - Phonograph - Google Patents

Description

June 29, 1937.

E. c. GUEDON PHONOGRAPH Filed Aug. 5;, 193a ZSnventor Gttomeg Pnemea June' 29,. 1937 UNITED STATES PATENT- OFFICE I 2,085,582 rnoNoGaArn Emile C.-Guedon, Audubon, N. J., assignor to Radio Corporation of Delaware of America, a corporation Application August 31, 1936, Serial No. 98,751

7 Claims.

' made in the art of recording and reproducing sound with high fidelity, and-theseadvances'have made it desirable to employ light-weight pick-up devices and light needle pressure on the'reco rds. It has been found that various automatic devices under control of the pick-up arm for operating start. and stop mechanisms or other apparatus at the completion of playing of .a record impose aheavy load upon the pick-up needles causing undue wear on both the needle and the record, and thereby seriously affecting the quality of reproduction. Another disadvantage of many prior art devices of this sort is that they are relatively noisy and therefore disturbing to the discriminating listener, while many of them are also so arranged that they will not operate unless-and until the needle has reached a predetermined radial position on the record in proximity to the center thereof. a

' The primary object of my invention is to provide improved mechanism for automatically controlling the operating condition of a phonograph, which mechanism will be free from the foregoing objections. v More specifically, it is an object of my present invention to provide improved mechanism of the type mentioned which, while under the control of the pick-up arm or other record scanning member, will not impose any undue load thereon. Another object of my invention is to provide improved mechanism as aforesaid which is extremely quiet in operation.

Still another object of my invention is to provide improved mechanism of the type set forth which will operate with any, standard record re-' .gardless of the length of the sound groove thereon,

or, in fact, with any type of record which atsom'e magnetic field provided by a suitable magnet as the record is played. As soon, however, as the pick-up arm is actuated by the terminal lead-in or other similar groove of the record, thecore is moved more rapidly and the change in flux created thereby through a coil around the magnet produces a current or voltage which is employed to actuate suitable relay mechanism which, in turn,

operates the phonograph control mechanism.

been

The novel features that I considercharacteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with additional objects and advantages thereof, will' best be understood: from a description of several embodiments thereof when read in connection with the accompanying drawing in which a Figure 1 is a plan view of one form of my invention,

Figure 2 is a fragmentary side elevation thereof,

'. and

Figure 3 a plan view of a modified form of my invention.

Referring more specifically to the drawing,

wherein similar reference characters designate corresponding parts throughout, I have shown, in Figs. 1 and 2, a turntable l which supports a record 3 in operative relation to a' needle 5 of a pick-up device 1 carried by a pick-up arm 9, the turntable I being driven by a shaft II which receives'power from a suitablemotor (not shown). The pick-up arm 9 is mounted on a post l3 for pivotal movement in a vertical plane and is guided in a horizontal direction along a guide rod' l5 on which a bearing or sleeve I1 fixed to the lower end of the post I3 is slidably received.

Extending forwardly from the sleeve I1 is an arm l9 which a second guide rod 2| may assist in supporting, the arm I9 having a core member or armature 23 of magnetic material fixed to its forward end for movement on a third guide rod 25 across the pole faces of a U-shaped magnet'Z'l.

A coil 29 of conductive material is wound around the magnet 21 and is connected to a very sensitive relay 3| of any suitable type (for example, a vacuum tube relay) which is arranged, when ener-' gized, to close a switch 33 in series with a second and much stronger relay 35 which may .be energized from a suitable-source, such as mains 31.

-If desired, a switch 39 may be inserted in circuit with. the coil 28 and the relay 3| and a second switch Min circuit with the relays 3| and as for controlling the respective circuits either manually or automatically.

The relay 35 may be suitably supported, as by a bracket 43 on which a rod 45 carrying a sleeve ll of magnetic material is pivotally mounted'in a position to engage an eccentric pin 49 on a mutilated gear 5 I. .The gear 5| is preferably frictionally coupled toits mounting shaft 53 andis rotatable on the stationary shaft 53 when the'frictional resistance offered by the frictional couplingis overcome. mounted on the shaft ll tobe continuously rotatable and to"rotate the gear 5| when its teeth .are brought into mesh with the teeth of the gear 55.

A second gear 55 may be rapid movement which creates a change of flux to be closed, or course.

through the coil 29, and a current or voltage of -sufiicient magnitude is induced in the coil 29 to actuate the relay 3|, assuming the switch 39 The relay 3| then closes the switch 33 which allows the coil "of the relay 35 to be energized if the switch 4| is also closed,-

and the core or armature 36 of the relay 35'then attracts the,sleeve 41 and draws the rod toward it a distance sufiicient to enable the free end of the" rod 45 to engage the eccentric pin 49 and impart initial rotation to the gear 5|. This causes the teeth of the gear 5| to mesh with the teeth of the gear whereby it continues to rotate and effect a series of automatic operations through suitable mechanism immaterial to the present invention and well known in the prior art, such as removing the pick-up from the turntable, changing records, and'replacing the pick-up on the new record. The mechanism may be arranged to open the switch 4lduring the cycle whereby the relay 35 is de-energized and the rod 45 reset under the influence of a spring 55, after which the switch 4| is again automatically closed. Eventually, during the cycle, the gear 5| again reaches the position shown in Fig. 1 and its rotation is stopped by the frictional coupling previously mentioned.

In. the; modification of my invention shown in ture 23 may then be made somewhat arcuate and the arm l9 considerably shortened to reduce its weight, and the magnet 21 is placed in the position shown. The operation of this form of theinvention is identical with that previously described in connection with Fig. 1.

Although I have shown and described but two modifications of ,my invention, I am fully aware that many other modifications thereof and changes therein are possible. For example, in place of the permanent magnet 21, an electromagnet may be usech Also, instead of operating automatic phonographi mechanism of the type herein referred-to, the relay 35 may be made to operate brake mechanism or the switch of an electric driving motor to stop rotation of the turntable. Many 'other changes will, no doubt,

readily suggest themselves to those skilled in the art, and I therefore desire that my invention shall not be limited except insofar as is necessitated by theprior art and by the spirit of the appended claims. I claim as my invention:

1. In a phonograph, the combination of a scanning member movable over a-record, means for automatically controlling the operating condition of the phonograph, means including asource.

of flux for rendering said first named means operative to alter the operatingacondition of the phonograph, and means movable with said scanning member and operable to affect the fiux upon a change in the rate of movement of said scanning member over. the record whereby to render said first named means operative.

2. In a phonograph, the combination of a record scanning member movable over a record, means for automatically controlling the operating condition of the phonograph, a source of magnetic flux, means associated with said fiux source for rendering said first named means operative to alter the operating condition of the phonograph, and means movable with said scanning member and operable to affect the flux upon a change in the rate of movement of said scanning member over the record whereby to energize said second named means and cause' the latter to render said first named means operative.

3. In a phonograph, thecombination of a record scanning member movable over a record, means for automatically controlling the operating condition ofthe phonograph, a source of magnetic flux, a coil of. conductive material associated with said source, means associated with said coil adapted to render said control means operative to alter the operating condition of the phonograph, and an armature coupled to and movable in response to said scanning member.

through said flux, said armature being effective, upon a change in the rate of movement of said scanning member over the record, to create a change of flux through said coil whereby to induce a. current therein for energizing said second namedmeans.

4. -In a phonograph, the combination of a scanning member movable over a record, means for automatically controlling the operating condition of the phonograph, a permanent magnet, a coil of conductive material around said magnet, means associated with said coil adapted to render said control means operative to alter the operating condition of the phonograph, and an armature coupled to said scanning member, said armature being arranged to be moved by said scanning faces of said magnet.

6. The invention set forth in claim 4 characterized in that the means associated with said coil for rendering the control means operative includes a sensitive relay adapted to be operated by the current induced in said coil.

7. The invention set forth in claim 4 characterized in that the means associated with said

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