US2146519A

US2146519A - Phonograph

Info

Publication number: US2146519A
Application number: US38683A
Authority: US
Inventors: Arthur G Zimmerman
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1935-08-31
Filing date: 1935-08-31
Publication date: 1939-02-07
Anticipated expiration: 1956-02-07

Description

Feb. 7, 1939. G Z|MMERMANI 2,146,519

PHONOGRAPH File ug. 31 1935 Patented Feb. 7, 1939 PATENT OFFICE PHONOGRAPH Arthur G. Zimmerman, Westmont, N. 1., assignor to Radio Corporation of America, a corporation of Delaware Application Augustin, 1935, Serial No. 38,683"

15 Claims.

This invention relates to phonographs, and more particularly to means for insuring a turntable supported disc record from slipping on the turntable during playing thereof.

It is well known that, in order to obtain satisfactory reproduction of sound from a record, the record must move at uniform speed relative to the sound translating device. Thus, in the case of a phonograph employing disc records, the turntable and the record supported thereby must rotate at uniform speed with respect to the pickup.

Carson and myself, Serial No. 13,796, we have disclosed a system for driving the turntable of a phonograph with such uniform speed that any slight variations which may occur therein produce no noticeable undesirable effects.- However, it occasionally happens that the record supported by the turntable slips slightly thereon, and this, of course, results in a noticeable variation in the pitch of the reproduced sound.

The primary object of my present invention is to provide an improved driving connection between the' record and the turntable whereby the aforementioned dimculty is overcome.-

More specifically, it is an'object of my invention to provide a novel record driving mechanism whereby the record will be driven positively from both its surfaces.

It is a further object of my invention to provide, for conventional-disc records, an improved record drive whereby a turntable supported record will be driven not only from the turntable but from the turntable spindle as well.

Another object of. my invention'is to provide an improved record weight which will not only press the record against the turntable, but which will have driving engagement with) the turntable spindle and which can be quickly and easily applied to conventional phonographs.

Still another object of my invention is to provide an improved record. weight as aforesaid which will be simple in construction and highly efiicient in use.

In accordance with my present invention, I provide a record weight with a bore to fit over the turntable spindle and provide means either within or in association with said bore whereby the weight may have driving engagement with the spindle. The record weight is also provided with a record engaging surface of such nature and so arranged that it will have frictional connection with the top surface of the record. Thus, the record is driven by the turntable at its'turn- In the copending application of Benjamin 1t.

table contacting surface and by the spindle driven weight at its opposite surface. The record engaging surface of the weight may, if desired, be so arranged, that a partial vacuum is created between it and the record, whereby the weight grips the record firmly to assist in rotating it without slipping on the turntable.

The novel features that I consider characteristic of my invention are set forth with particular'ity in the appended claims. However, the 'invention itself, together with additional objects and advantages thereof, will best be understood from the following description of two specific embodiments thereof, when read in connection with the accompanying drawing in which Figurev 1 is a view, partly in section, of one form of my improved record weight,

' Figure 2 is a sectional view taken on the line 2-2 of Figure 1, x

Figure 3 is a detail perspective view of a 'plate for providing driving connection between the spindle and the record weight'according to one form of my invention.

Figure 4 is a fragmentary, detail perspective of the spindle, and

Figure 5 -is a fra entary, sectional detail 'showing a modified form of my invention.

Referring more specifically to the drawing, wherein like reference characters designate corresponding parts' throughout, there is shown a motorboard l which supports a motor 3 for driving a turntable spindle 5 on which is supported a turntable 'l. The turntable has driving engagement with the spindle 5 through the cross pin 9 which isreceived by the turntable hub II, and it is provided with the usual felt surface (not shown), on which a record R rests, the felt serving to provide a frictional drive between the record and the turntable. The construction thus far described is more or less conventional and is subject to the disadvantages heretofore pointed out,

To insure against slipping of the record R on the turntable I, I preferably form the protruding end 5aof the spindle 5 of a non-circular shape and cause it to drive a record weight l3 which rests on the record R. The weight [3 is made of a mass of metal and is provided with a central bore I 5 for receiving the spindle end 5a when it is placed on a record, while a driving plate l1, secured to the mass I 3 by the screws l9 and provided with an aperture 2| of a configuration corresponding to the shape of the spindle end 5a, serves to provide a driving connection between the spindle 5 and the mass l3. In the particular embodiment illustrated in Figs. 1 to 3, the end 511. is shown square with the corners to thereof rounded off somewhat to prevent injury to the hands and to the record, the aperture 2i being also square and of a dimension to snugly fit over the end a.- The spindle end So and the aperture 2| may, obviously, beformed of any other polygonal or other suitable shape (for example, elliptical), it being merely necessary that a positive driving coupling be effected between the spindle 5 and the driving plate 91.

To the bottom of the mass it is afiixed a base 23 having agreater diameter than the mass it, -a resilient disc 25 of substantially equal diameter.

i9 and the plate H and without the use of any cement or other adhesive. By making the driving plate ll concentric with the base Hand of much smaller diameter than that of the disc 25, the peripheral portion of the live rubber disc will be free to readily accommodate itself to any irregularities in the surface of the record which it engages under the pressure of the mass l3, and a firm gripping action will result. In some cases, as where the base 23 and the disc 25 are dished slightly away from the record R, as shown in Fig. 1, a partial vacuum is created-when the weight i3 is pressed against the record, thereby enhancing the gripping action between the disc 25 and the record. In any event, it will be seen that this provides an additional drive for the record R and that the record is prevented from slipping on the turntable because it is driven from its lower surface by the turntable itself and from its upper surface by the weight it.

The form of my invention heretofore described requires that the spindle end 5a and the aperture 2! be specially formed. For conventional phonoraphs employing the usual cylindrical spindle, the modification shown in Figure 5 may be used. In this form, the plate H is provided with a plurality of gripping members, such assprings 2'5,

which extend into the bore in converging relation and which-firmly grip the spindle 5 to provide the necessary driving connection between the spindle and the weight.

Although I have shown and described several embodiments of my invention, I am fully aware' I claim as my invention:

1'. In a phonograph, the combination of a driving member, a turntable having driving engagement therewith, arecord supported on said turntable, and means resting on said record and hav-' -ing driving connection with said member, said j means also having gripping engagement with said recordwhereby said record is adapted to be driven a phonograph, the combination of a driving member, a turntablehaving driving engageboth by said turntable and by said means,

" ment therewith, a record supported on said turntable,- and a record weight restingon said record and having driving connection with said member,-

said 1 weight having gripping engagement with saidrecord whereby said record is adapted. to be driven both by said turntable and by said weight.

3. In a phonograph, the combination of a motor driven spindle, a turntable having driving enaieatie 'portion and said weight has a member provided with a correspondingly shaped aperture adapted to receive said non-circular portion whereby to provide driving connection between said spindle and said weight.

5. The invention set forth in claim 3 characterized in that the spindle has a substantially square portion at its upper end and said weight has a driving plate amxed thereto, said plate having a substantially square opening therein adapted to receive said square portion 'of the spindle whereby to provide driving connection between said spindle and said weight.

6. The invention set forth in claim 3 characterized in that the weight has a resilient member aflixed thereto for providing gripping engagement with the. record.

'7. A record weight comprising a mass having a bore therein'extending from its base whereby the weight may be fitted over a phonograph spindle, a driving plate secured to said base for providing driving connection between said mass and said spindle, and a resilient member on said base for engaging a phonograph record threaded on said spindle whereby to provide gripping engagement between said mass and said record.

8. The invention set forth in claim 7 characterized in that said resilient member comprises a-disc of live rubber.

9. The invention set forth in claim 7 characterized in that the base of said mass is of greater diameter than the body portion thereof, characterized further in that said driving plate is concentric with said base and has a much smaller diameter than the base, and characterized still further in that said resilient member comprises a disc of live rubber of a diameter substantially equal to that of said base, said rubber disc being held against said base solely by'said driving plate whereby the peripheral portion of said rubber disc is free to snugly engage the record in firm gripping engagement therewith.

10. The invention set forth in claim 7 characterized in that said driving plate is provided with a spindle gripping member.

11. The invention set forth in claim 7 characterized in that said driving plate is provided with a plurality of resilient spindle gripping elements adapted to cooperate mutually to grip said spindle.

. 12. The invention set forth in claim 7 char? acterized in that said driving plate is provided with aplurality of resilient spindle gripping elements extending into said bore in converging relation,

13. Ina phonograph, the combination of a turntable spindle having'an end portion of noncircular shape, and a record weight; said'record weight having a central'bore for receiving said end portion and having a driving plate afiixed thereto, and said driving 'plate having an aperture therein of corresponding'shape to receive said 2,140,519 3 acterized inthat said spindle end portion issubacterized in that said spindle end portion is substantially polygonal and said aperture is corstantially square and said aperture is also square, respondingly substantially polygonal, said driving said driving plate being affixed to the base of plate being afllxecl to the base of said weight said weight with its aperture coaxial with said with its aperture substantially coaxial with said bore. 5 base. l ARTHUR G. ZIMMERMAN.

15. The invention set forth in claim 13 char-