US2386503A - Driving mechanism for phonograph turntables - Google Patents

Description

Oct 9, 1945. J. H. PRESSLEY x 5,

DRIVING MECHANISM FOR PHONOGRAPH TURNTABLES Filed Jan. 29, 1942 FIG.3

' 'IIIII'IIIIIIIIIII I INVENTOR A PRESSL-EY 1 1 Patented Oct. 9, 1945 DRIVING MECHANISM FOR PHONOGRAPH TURNTABLES Jackson H. Pressley, Marion, Ind., assignor to Farnsworth Television and Radio Corporation,

a corporation of Delaware Application January 29, 1942, Serial No. 428,63

4 Claims;

This invention relates to a phonograph and more particularly to the mounting of a motor for driving a turntable.

It is well known in the phonograph art that it is hardly possible to manufacture driving motors .which are so mechanically and electrically perfect that they are not a source or mechanical vi-bi'ation. According to conventional phonographs. these mechanical vibrations are a great source of annoyance for the reason that they are transmitted to the turntable and aifect the quality or reproduction of records on the turntable.

The object of the present invention, therefore,

is to provide a phonograph in which the driving motor is mounted in such a manner that the mechanical vibrations created thereby are not transmitted to the turntable.

Another object of the present invention is to provide a. phonograph in which the driving motor is mounted in the manner set forth, the cost of which is greatly reduced and which is highly efiiclent in eliminating the transference of vibrations to the turntable.

In accordance with the present invention, there is-provided a phonograph having a base member on which a turntable is rotatably mounted. Extending below the base member there are provided a plurality of supporting members with vibration eliminating elements. A motor is suphaving a downwardly extending peripheral rim Ills fixed in a suitable manner to a spindle IE to rotate therewith.

A mounting member or plate H, by means of screws or pins i8, is connected to the base member Ill over the opening H. Vibration eliminating elements or grommets l9 are placed between the plate l1 and the base member ill for preventing the transference of motor vibrations to the turntable l4. 1

The vibration eliminating elements is may be rubber but, preferably, they should be of materials known commercially under the names of ported by the supporting members and is engaged at its sides by the vibration eliminating elements for eliminating the vibrations of the motor. The

motor has a driving member for driving the turntable.

, For a better understanding of the invention, together with other and further objects thereof, reference is bad to the iollowing description, taken in connection with the accompanying drawinmanditsscopewillbepointedoutintheappended claims.

In the accompanying drawing: Fig. 1 is a top plan view showing the mountin: oi the driving motor and the association of the-driving motor with the turntable;

Fig. 2 is a side view oi-the apparatus shown in Fig. 1;and v Fig. 3 is a fragmentary sectional view showing Glyptal, Pyralin, Viscoloid, printers roll and other names, depending upon the source of supply. Specifically, the vibration eliminating material employed should have the following properties and characteristics to a high degree: It should have great molecular inertia and such kinematic qualities as to offer considerable resistance to the transmission of wave motion. Apparently; the I molecules of such material are capable of being subjected to an inertia action when a distorting force is applied thereto, and the material is capable of readily absorbingwithin itself and relatively slowly dissipating the energy supplied thereto. In other words the material should have high internal friction. Such properties in material make it especially fit for use in preventing the transfer of mechanical vibration.

A motor 20 having a driving member?! i rigidly connected to the bottom of the mounting member ll by means of pins 23. The driving member 2! extends above the base member In and themounting member ii and is adapted to cooperate in driving the turntable M. As shown in the drawing, the end of the driving member 2!, which extends above the members ill and I! is provided with an annular member 24, of rubber or other vibration eliminating material, which is adapted to engage the peripheral wall of a friction wheel 25. The periphery of the wheel 25 is also of rubber or other vibration eliminating material. The friction wheel .25 is rotatably mounted on a plate 26 and is also adapted to engage the inner peripheral wall l5 of the tumthe manner in which the turntable i associated with the base member.

Reierring now particularly to Figs. 1 and 3 of the drawing, there is'shown a base member In having openings II and I2. Abracket l3 isnxed beneath the base member II at the opening ii in the manner shown in Fig. 3. A turntable ll,

table It. The plate 26 is movably connected to the mounting member ll, preferably in the manner shown in Fig. 1. A spring 28 is connected to the plate 26 and the mounting member I! for maintaining the friction wheel 25 in continual driving engagement with the annular member 24 and the inner peripheral wall of the turntable l4.

While the preferred method of driving the 'ror driving a turntable well known in the art may be used. a

- cally opposite relative to the driving member iii,

to eliminate the transference of vibration from the motor Ell to the turntable l4. Elements made of both rubber and Pyralin have been used by applicant. The Pyralin elements gave much more satisfactory results.

While the manner of mounting the motor 26 Just described and shown in the drawing is preferred, the invention is not limited to this particular motormounting. The members 2% and so may serve as the sole supporting means for the motor 2b. When the motor 2b is supported solely by the members 29 and 363, the members preferably are provided, respectively, with ears .tll3t and till-3d to prevent vertical movement of the motor 2b.

While there has been described what is st present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modiflcatiom may be made therein without departing from the invention, and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

l. A support for a motor comprisinrs'a bane 2,sse,soe I said motor, a pair of members extending from. said base member on opposite sides of said motor, said members being provided with elements of vibration-eliminating material for engaging said motor whereby vibrations from said motor are absorbed by said elements.

2. A support for a motor including a base member, means for supporting said motor on seid base member, means of vibration-eliminating material between said supporting means and said base member for absorbing vibrations from said motor, a pair of members extending from'sald base memher on opposite sides of said motor in planes sub:

member, means for supporting said motor on said base member, means of vibration-eliminating material between said supporting means and said base member for absorbing vibrntions from bers extending from said base member on cppc-.

site sides of said motor in planes substantially parallel to the longitudinal axis of said motor,

said members being provided with elements or vibration-eliminating material for engaging said motor whereby vibrations from seid motor are absorbed by said elements.

4. A support for a. motor including a base member, means for supporting said motor on said base member, means of vibration-eliminating material between said supporting means end smd base member for absorbing vibrations from sold motor, a pair of members extending from said base member on diametrically opposite sides of I said motor, said members being provided with elements or vibration-eliminating materiel for engaging said. motor whereby vibrations said motor are absorbed by said elements.

morrson' n.

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