US2051799A - Two-speed motor - Google Patents

Description

Aug. 18, 1936.

J. B. SUOMALA TWO-SPEED MOTOR Filed June 50,- 1932 Patented Aug. 18, 1936 Two-SPEED MOTOR John B. Suomala, Camden, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application June 30, 1932, Serial No. 620,5[08

13 Claims.

My invention relates to` turntable drives and more particularly, although not exclusively, to a plural speed drive for phonograph turntables.

In reproducing sound from records of the disc type, it is customary to rotate the disc at a constant predetermined speed. Until recently, substantially all phonographs of the disc record type have been so designed that the turntable or record supports thereof rotate at 78 R. P. M. By reason of improved recording and reproducing methods, however, phonograph records requiring a much lower angular speed, as, for example, 331A; R. P. M., are now available. Obviously,such records cannot satisfactorily be reproduced on the majority of existing phonographs since the speed regulating mechanisms thereof cannot be adjusted to maintain the extreme constancy of angular velocity required by the new slowly-rotating records, better known commercially as long-playing records. It will be obvious, therefore, that a record tablet intended for reproduction by phonograph apparatus of one type cannot be properly reproduced by phonograph apparatus of 'the other type.

It is, therefore, the primary object of my invention to provide an improved turntable drive for phonographs whereby diierent angular speeds may be transmitted to the turntable at will.

A further object of my invention is to provide a phonograph motor having a plural speed turntable drive mechanism formedintegrally therewith. Y

Another object of my invention is to provide a plural speed turntable drive mechanism and a control device therefor as an integral part of the phonograph motor.

A further object of my invention is to provide a phonograph which is adapted for the proper reproduction of record tablets which operate a different angular speeds.

Another object of my invention is to provide a phonograph having a two-speed turntable drive mechanism whereby record discs, each operable at a different reproducing speed, may be'reproduced at their own proper reproducing speeds.

A further object of my invention is to provide a phonograph mechanism which may be operated independently of, or which may be combined with a portable type of moving picture projector adapted for the synchronization of sound with motion pictures, as, for example, in the home, and wherein the angular velocity of the phonograph reproduction of the usual type of record tablet or turntable may be quickly changed at will for the special record tablets adapted for reproduction of sound in conjunction with motion pictures.

More specifically stated, it is an object of my invention to provide a unitary turntablev drive mechanism for phonographs whereby underone operating condition, as, for example, in the reproduction of standard record tablets, the turntable may be driven through one coupling to a motive means at a given speed, while under another operating condition, as, for example, in the reproduction of long-playing records or the synchronization of special sound records with moving picture apparatus, the turntable will be driven by the same motive means but through another coupling at another given speed, thev change from one coupling to the other being possible instantly and at will.

A preferred embodiment of my invention by which the above objects, and other objects ancillary thereto, maybe accomplished 'comprises a motor having tWo independent control devices, either one of which may be rendered operative to determine the speed Vat which the motor spindle shall operate, through means forming a part of thel said spindle. a Y

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. 'I'he invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specic embodiment When read in connection with the accompanying drawing, in which -f Figure l is an assembly view of one form of my invention in elevation with certain parts in section to better illustrate the same.

Fig. 2 is a sectional view taken on the line 2-2 Y,

of Fig. 1, with certain parts shown in Fig. 1 omitted. I

Fig. 3 is a detail sectional view taken on the line 3 3 of Fig. 2.

Fig. 4 is a detail sectional View taken on the line 4-'4 ofFig. 2. I

Fig. 5 is a fragmentary sectional view taken on the line 5-5 of Fig. 4.

Referring more particularly to the drawing, wherein similar reference charactersV indicate corresponding parts throughout, a conventional induction disc motor, generally indicated at I, comprises operating'field and core windings II and I2, a spindle I3, a disc armature I4 carried by the spindle I3, a'centrifugal governor I5 disposed in cooperative engagement with a worm y gear I6 carried by the spindle I3 to hold the said spindle to a speed of substantially 78 R. P. M. when the operating windings are energized, and an adjustable speed regulating lever I'I for controlling the governor I5.

As shown, the motor I0 may, for example, be attached to the underside of a motor-board I8 by means of suitable screw bolts or the like, an enlarged opening I9 being provided in the. motorboard for passagev therethrough: of the upper end portion of the spindle I3 which is adapted to support and rotate a turntable 20' in a position abovel said motor-board. A

In accordance with my invention, I provide the motor I0 with an auxiliary governor 2| in addition to the usual governor I5 whereby the motor I0 may be optionally controlled to operate at a speed of substantially 331/3 R. P. M. as well as a standard speed of substantially 78- R. P. M'. To this end, an additional centrifugal governor as` sembly comprising a governor worm shaft 22, a friction disc 23, a.plura-lity oir flyweights 214i carried by a like: number ofl spring. blades= 25, and a known: type of' speed regulating device 2li are operatively assembled on a bearing bracket 2T. The

bracket is. secured' to the frame 2,8 of the motor I0- in the example shown by means of'a plurality of machine screws 29- or the like, with the governor shaftA 22 in spaced' relation to the spindle I3-,. the axes: of the spindle lf3v and` the governor worm shaft: 22 lying in` planes normal? to' each other; In practice, however, the-bracket 21? may beformed as an integral' part of the motor frame 28; iff desired. f

The auxiliary worm gear 30'; preferably of 'nonmetallic material, havin-g' a bearing hub 3`I suitably staked orotherwise secured thereto, is rotatably mounted on the spindle I3 and in cooperative-engagement with theworxrr formed on the governor shaft 22a In order that the auxiliary'wormgear 30 may becoupled tothe spindle I3P to effect the' second predeterminedI speed, I' provide` a clutch mechanisnr which includes the upper end portion of,

portion of' the spindle I3 is provided' with a suitv abl'e bore 32r which extendsinwardly from its free end' to a predetern'ii'neddepth. Disposed in the bore-32 for-slidingmovement therein isa plunger 33 which serves as a. clutch controll member andl as a1 record centering pin, inasmuchas the upper end of the plunger 33 projects beyond the uppermost end of the spindle I3'.

Movement of the plunger 3 3 in the bore 3,2: is limitedby means of an elongated'V slot 34 formed. in the plunger 33`adjacent. the lower end thereof', and a pin 35 which p asses. through theslotv 34 and thev motor spindle I3 in which. it is securely held as by a force lit therein. The slot 34 andthe pin- 35 cooperate to permit limited upward and downward' movement of' the plunger 33 withinthebore 32 as clearly shown, in Fig. 2.A

The pin 35' acts, further, to support and drivel the turntable 20 whichis provided with adepending boss 36 having elongatedrslots 31 formed in the bottom face thereof,l the, slots 3l communicating with the turntable bore. 38 atfdiametrically opposed, points. The said slots: 3J are adapted to receive the projectingend portionsv of the pin 35V therein when the turntable isv mounted on the spindle |32 in; a manner wellknown inthe art.

A pin 39 is fcrcefitted' intor an opening 4'0- in the plunger 33' ata point below the slot 34 and yan` elongated slot 4Iv is` formed in-thewa1ls of the spindle I3 to provide clearance for the lateral projecting end portions of the pin 39, so that the plunger 33 is free for limited sliding movement in the bore 32. The upper face of the bearing hub 3| which supports the worm gear 30 is provided with a plurality of aligned slots 42 which communicate with the central opening 43 therein at diametrically opposed points and are adapted' to receive; the pinf 39 therein wherebytheworm gear 30 may be coupled to the spindle I3 in a manner hereinafter described.

In order that the plunger 33 may be yieldably maintained in either its raised (unclutched) or loweredy (clutched) position, I provide a collar 44 whichis-secured to the spindle I3 in close proximity to the bearing hub 30 by means of a set screw 45. The collar 44 is further provided at a point diametricallyopposite the said screw 45 with a threaded opening 46 for the reception of a short pin 4l having one end thereof substantially pointed', a spring 48,', and, fin-ally, a set screw 4:9A to maintain the pin 4.1 and spring 48 within: the; opening 4.6 and the pointed endl ot the pirr`4l in yieldab'lecontact with the plunger 334.

'I'he plunger; 33: is: provided4 adjacentV its lower' end with two.: longitudinallyf spaced. notches or recesses 53 for the` reception of the pointed end oi the pin 4'I-\vhereby,V upon engagement of the pin 4'I.7 with. either: one or the: other of the recesses 5llf, .the plunger 33 will. be yieldably retainedf i'n either its raised or lowered posi-tiony as; the case may be..

The operation of my improved two-speedv m0- tor' should now be apparent from the foregoing description. Assumingrst, that itis desiredl` to playa standard' record' operable at 78.122. P. the: plunger 33" is raised tothe position shownE in Figs; 1 and.I 2. The motor I0 now drives through thelower portion of the spindle Ii3 including the bore 32, the transverse pi-'n 35 to the plunger 3-3, which causesV rotation ofthe pin 35, the boss 36, and the turntable 20a When the plunger 33 is in: the raised* position, the speed! of'A the motor is controlled by the governor I5, which is so set tha-tthe turntable will' rotate at 78 R. P. M'.

Should it be desired, now, toplay one of the new-so-ca-lledI long-playing records, it is merely" necessary to depress' the plunger 33 until the pin 33:' has entered the slots 42. The turntable 20 is now drivenfronr the lower part of the spindle I3', through the slotted bearing hub 3|, the pin 39, the plunger 33, the pin 35 and the boss36 However, inasmuch as the worm gear 30 is' staked to the bearing hub 3If and is coupled to the governor 2I, the latter immediately comes into operation to control the speed of the' turntable 20 at the speed'l fory which the governor 2|l isset, namely, 331/3 R. P; M. Y

Sin-ce the auxiliary Worm gear 30 is' over twice as large as the worm gear' I6, it will be obvious that when the spindley I3-is-controlled1 by the governor 2l, it will not be rotated fast enough to cause the' governor I5 tofunction asv a controlling device. Hence, the governor I'5 becomes in operative to control! the speed of the turntable' 2D.

When it is desired to reproduce records which have been recorded in part at a, speed; of" 78 R. and in part at a speed. of 331/3 Rf. P. M., it is only necessary, with my improved motor, tol manipulate the. plunger 33,v even while. the turntable is still in motion, so to chang-e the speed ofY the turntable, 2D. in accordance with the differently recorded sound grooves on such a record. The change can be made during the Gan silent portion between the several grooves, and may even be made automatically, if desired, by any suitable mechanism.

Although I have shown and described one speciic embodiment of my invention, I am fully aware that many modifications thereof are possible. Furthermore, while I have described my invention as applied to the reproduction of records, it should be understood that the invention is equally applicable to machines for recording sound. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

I claim:-

1. In combination, a motor including a spindle, a plurality of control devices associated with and adapted to individually control said motor, and means associated with the uppermost free end portion of said spindle whereby either one of said control devices may be selectively rendered eiective or ineffective to control said motor.

2. In combination, a motor including a spindle, a plurality of control devices associated with and adapted to individually control said motor, and means slidably carried substantially within said spindle and adjustable relatively thereto whereby either one of said control devices may be selectively rendered eiective or ineffective to control said motor.

3. In combination, a motor including a. spindle, a plurality of governor devices associated with and adapted to individually control said motor, and means slidably carried substantially within said spindle and adjustable relatively thereto whereby either one of said governor devices may be rendered eiTective or ineffective to control said motor.

4. In combination, a motor including a spindle, a pair of governor devices associated with and adapted to individually control said mo-tor, and means slidably carried substantially within said spindle and adjustable relatively thereto, for selectively coupling either one of said governor devices to said spindle whereby the other of said devices is rendered ineffective to control said motor.

5. In combination, a motor including a spindle, a pair of governor devices associated with and adapted to individually control said motor, adjustable means carried by and slidable relatively to said spindle for selectively coupling one of said governor devices to and uncoupling the same from said spindle, and means for yieldably maintaining said slidable means in adjusted position.

6. In combination, a motor including a spindle, a pair of governor devices associated with and adapted to individually control said motor, and means carried by and slidable substantially within one end portion of said spindle for selectively coupling one of said governor devices to and uncoupling the same from said spindle, during the operation of said motor whereby the other one of said devices is rendered respectively ineffective or effective to control said motor.

'7. In combination, a motor including a spindle, a pair of governor devices associated with and adapted to individually control said motor, and means slidably carried substantially within said spindle and movable relatively thereto for selectively coupling and uncoupling one of said governors to and from said spindle.

8. In combination, a motor including a spindle, a pair oi governor devices associated With and adapted to individually control said motor, and means slidably carried substantially within said spindle and movable relative thereto for selectively coupling and uncoupling one of said governors to and from said spindle to render the other one of said devices respectively ineffective and effective to control said motor.

9. In combination, a motor including a spindle, a pair of governor devices associated with and adapted to individually control said motor, and means carried by and slidable within said spindle to one of two positions for coupling one of said devices to said spindle while rendering the other of said governor devices ineiTective to control said motor, and slidable to the other of said positions for uncoupling the first of said devices from said spindle and rendering the other of said devices effective to control said motor.

10. In combination, a motor including a spindle, a pair of governor devices associated with and adapted to individually control said motor, means carried by and slidable within said spindle to one of two positions for coupling-one of said devices to said spindle while rendering the other of said governor devices ineffective to control said motor, and slidable to the other of said positions for uncoupling the iirst of said devices from said spindle and rendering the other of said devices effective to control said motor, and means for yieldably maintaining said slidable means in either o-ne of said positions.

11. In combination, a motor including a spindle, a pair of governor devices associated with and adapted to independently control said motor, means adjustable for regulating one of said control devices, means independent of said last named means and also adjustable for regulating the other of said control devices, and means slidably carried substantially Within one end portion of said spindle and movable relative thereto for selectively rendering either one of said control devices effective or ineiective to control said motor.

12. In combination, a motor including a spindle, a governor device associated with and adapted to control said motor at one predetermined speed, an auxiliary governor device associated With and adapted to control said motor at another predetermined speed, and means slidably carried substantially Within one end portion of said spindle and movable relative thereto whereby said aLLxiliary governor device may bel selectively coupled to and uncoupled from said spindle, said rst named governor device being automatically rendered ineffective when said auxiliary governor is rendered effective to control the motor.

13. In combination, a motor including a spindle, a governor device associated with and adapted to control said motor at one predetermined speed, an auxiliary governor device associated with and adapted to control said motor at another predetermined speed, means separately adjustable for regulating each of said governor devices, and means slidably carried substantially within o-ne end portion of said spindle and movable relative thereto whereby said auxiliary governor device may be selectively coupled to and uncoupled from said spindle.

JOI-IN B. SUOMALA.

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