US2381927A

US2381927A - Turntable for phonographs and sound recorders

Info

Publication number: US2381927A
Application number: US420725A
Authority: US
Inventors: Vernon L Roberts
Original assignee: RICHARD H WANN
Current assignee: RICHARD H WANN
Priority date: 1941-11-27
Filing date: 1941-11-27
Publication date: 1945-08-14
Anticipated expiration: 1962-08-14

Description

Aug. 14,1945, v, L. ROBERTS 7 TURNTABLE FOR PHONOGRAPHS AND SOUND RECORDERS Filed Nov. 27, 1941 a 22' 7R4 hi 1 52 7; jf

Patented Aug. 14, 1945 I 7 2,381,927 r TURNTABLEFOR PHONOGRAPHS AND r SOUND RECORDERS Vernon L. Roberts, Chicago, Ill., assignor of one r j half to Richard H. Wann, Detroit, Mich.

- Application November 27, 1941', Serial No. 420,725

My invention relates to turntables for phonographs and sound recorders, andhas to 'do more particularly with a turntable which is especially cdesigned for home machines which are adapted for makingand playing sound records.

In the manufacture of commercial sound discs, it is customary to equip'the disc with an eccentric control groove communicating with the terminal portionof thespiral'sound' groove, this eccentric groove functioning to impart an in-and-out .movement .to thereproducing stylus and tone arm Said' movement actuates a stop mechanism, record changing'mechanismmr the like.

In the making of home records, it has heretofore not'been -considered feasible to apply to the record such .an eccentric groove and this has resulted inconsiderable inconvenience to-the' user because of the necessity of manual control following the playing of each home' recordingr I :In my copending application, SerialNo. 387,- f

800, filed April 10,1 1941,'noW Patent No. 2,309,276, granted. Jan; 26, 11943, I have suggested a means of providing aneccentric groove'to a record by a record may be rotated alternatively either on its truecenter or on an axis ofiset from the center of thedisc, resulting in an eccentric groove. 7

Anotherobject is to provide such an arrang e- 'ment which will be simple in construction; inex pensive to-' fabricate and, in. general, entirely satisfactoryfor the purposes desired.

Referring now to the drawing forming a part of this specification and illustrating certain preferred embodiments-of.-my-invention 1 Fig, 1- is a top planview ofaturntable'constituting-one't-means of practicing my invention; Fig. 2 is a diametrical sectional view taken substantially along the line 2-2 of Fig.1;

Fig. -3 is a plan view showing'another'embodiment of my invention; 1 Fig. 4 is an elevational View taken from a point substantiallyalong the line 44 of Fig. 3;

:Fig. 5' is a plan view of still another embodiment of my invention; and

i Fig. 6 is a perspective View of anelement of the embodiment shown in Fig. 5; Referring first to the form shown in FigsJl and 2, the numeral It] represents generally a'turntable mounted on a support I 2, the latter being in turn rotatably connected to motor drive mechanism (not shown). The turntable ID is provided with a spring-pressed locking pin l5 which is adapted to seat in a recess in a record at a point near the center-thereof to prevent slippage between'the record and. turntable, and theturntable is also provided with a center threaded hole I 6 receiving a locking spindle l8 for securing the record through its center aperture in axial alinement with. the turntable.

According to my invention, another threaded aperture 20 is provided in the turntable at the same distance from the locking pin l5 as the aperture Hi. This aperture 20 is preferably disposed as close to the center aperture'lfi as possible, in order that'a'control groove of smallest diameter may be provided and thus permit production of a record of maximum length.

Use of the turntable just described will be readily apparent. The blank record isfirst secured to.

the turntable with its center hole in registry with the turntable center hole IS, the clamping element l8 being threaded into the hole -16 and' thelocking pin ['5 in registry with-the recess formed-for the purpose in most standard records. The record is made by traversing the cutting stylus in a spiral path from a point near the periphery of the record to some point between the periphery and 'the center, in accordance with standard practice.

After the sound groove has been completed, the record is removed from its original position to a position with its center hole in registry with the off-center threaded hole 20.

This operation, of course, may be done without removing the record from the turntable, since it may he slid thereon while being retained with its locking recess inengagement with the locking pin i'5;' The record is then again secured by the clamping element It with its center hole in registry with the 01f center hole 20 of the turntable.

The recording stylus is then replaced in the sound grooveat or adjacent the inner terminus thereof and the turntable is again set in motion. Obvi'- 21, which, may, if desired, extend through the turntable and function as a record locking pin similarly to the pin 15 in Figs. .1 and 2. The arm 25 carries a stud 30 adjacent its inner extremity, this stud extending through a slot 32 passing through the center-of the turntable. This slot is preferably an arc having as a radius its distance'from pin 21. The arm 25 extends beyond the periphery of the turntable to provide a hamdle portion, as seen best in Fig. 3, and the marginal iiange 33 of the turntable may be provided with a pa1r of spaced slots 34, 34' snugly receiving the arm 25, an elongated slot 35 connecting the slots 34 and 34'. The arm by its own resilience or otherwise may be firmly. retained alternatively in one of the slots 34, 34'.

It will be seen that when the arm is fixed in the slot 34, the pin is centrally disposed with reference to the turntable while, when the arm is moved into the sot 34, the pinds off: center,

where it will function in the formation r an eccentric groove in a record.

In the embodiment shown inFigs. 5 and 6, the

turntable IE1 is provided with a tapered socket 40, which extends from the center of the turn table to a point the'rebeyond. seated a similarly tapered plug 42 which carries, preferahl r integrally therewith, ,a stud 45'. It will be seen that by reversingthe plug 421m the socket Ml thestud 5 may bepositioned either centrally of--the record or off center, so that it may hetused in the manner described above either for saidaperture of the-disc,v means enablingsaid studi-to be adjusted from a position atthe center of. the turntable to a. position eccentric thereto, and meansapositively holding the stud at either position. against movement transversely of its axis.

2. A'turntablefor supporting a record disc which has a central aperture, 'a driving stud cocentrically disposed in the turntable, and a second stud upstanding from the turntable and engageab-le.- in said aperture of the disc, and means-enabling said stud to be adjusted from a position at the center of the turntable to a posi- In this socket istion eccentric thereto, said second stud being disposedi-at the same distance from said driving stud in both positions.

3,..A turntable forv supporting a record disc which hasia central aperture, a driving stud ecccntrically disposed'in the turntable, a lever fulcrumed on the under side of thet'able at the axis of. said driving stud, the table having anopening in. its central portion" and a second stud carried by said lever and upstanding through said opening for engagementin the aperture of the disc, said opening in. the table being dimensioned to accommodatethe stud at the center of the table and also at a position eccentric thereto and the lever being movable about its axis to shift said I stud from one position to the other.

4. A turntable for supportinga record disc which has a central aperture, a driving stud eccentrically disposed in the turntable, a lever fulcrumed' on the under side of the table at the axis of said driving stud, thetable having an opening in its central portion and a second stud carried by said lever and upstanding through said open ing for engagement in the aperture of the disc,

saidopening in the table being dimensioned to accommodate the stud at the center of the table and also at a position eccentric thereto and the lever being movable about. its axis to shift said stud from oneposition to the" other, together with means which locks the lever when the stud is adjusted at either of said positions.

5. A turntable for supporting a record disc which has a central aperture, said table having a recess formed at the f center of the table and extending outwardly for a. limited distance, a

stud dimensioned to fit the aperture of the disc, and means supporting said stud in the recess of the table and upstanding from the latter, said supporting means being adjustable to position said stud either adjacent one end of the recess and at the center of the table or adjacent the EOithEIlT-EflldiOf the recess and in eccentric relation to the table.

6;:A- turntable for' supporting a record disc which has a: :central aperture, 2. driving stud eocentrically disposed in the turntable, said table havingrarecessformed at thecenter of the table and extending outwardly for a limited distance,

a second studdimensioned'to fit the aperture of the disc, means supporting said second stud in the recess of the table and upstanding from the-latter, said supporting means being adjustable-to position said second stud either adjacent one-end-of the recess and at the center of the table or, adj acentthe other end ofv the recess and in eccentric relation to the table, said second stud being: disposed at the same distance from the dniving stud in both positions.

'7. A turntable for supporting a record disc which has acentral aperture, a threaded stud dimensioned to fit the aperture of the disc, the table having a threaded opening at its center to receive the stud and a second threaded opening-for said stud at an eccentric position.

8. A turntable for supporting a record disc which has azcentral aperture, the table having arecess, a block fitted in saidrecess with a stud upstanding from the block dimensioned to engage the aperture of the disc, said block being adj-ustable in the recess with the stud disposed either at the center of the table or in eccentric relation thereto.

9. A turntable for supporting a record disc which has a central aperture, the table having a pair of recesses, one at the center of the table and one in eccentric relation thereto, and a stud removably and. selectively engageable in either recess and dimensioned to'project above the surface of the table when so engaged and to fit the aperture of thedisc.

10. A turntable for supporting a sound rec- 0rd, a-record positioning element carried by said turntable-for positioning a record in definite relations thereto, said turntable having means to supportand hold said element in alternative positionaoneof said positions being co-axial with said turntable and theother'position being eccentric. to said. turntable;

11. A turntable to support a record disc, and astudin upstanding relation to said turntable to project upwardly into an aperture at the cen ter of the record disc, said turntable having space co-axial therewith and space eccentric thereto, for accommodating said stud selectively in co-axial and eccentric relation to said turntable.

VERNON L. ROBERTS.