US2289357A - Record changing mechanism for phonographs - Google Patents

Description

July 14, 1942. L. a; GREEN RECORD bHANGING MECHANISM FOR PHON OGRAPHS Filed March 28, 1940 3- Sheets-Sheet 1 F514. 5 a B. .zim mvmon BY KMTTT hit.

I ATTORNEY.

July 14, 1942.

L. B. GREEN anconncmusme MECHANISM FOR PHONOGRAPHS Filed March 28, 1940' v 3 Sheets-Sheet 3 INVENTOR.

Patented July 14, 1942 nncoan CHANGING MECHANISM FOR PHONOGRAPHS Lee B. Green, Lakewood, Ohio, assignor to The General Industries Company, Elyria,

corporation of Ohio Ohio, a

Application March 1940, Serial No. 326,443

3 Claims.

My invention relates to record changing mechanisms for phonographs, and relates more particularly to record changing mechanisms of the general type wherein a stack of records, normally supported above a phonograph turntable, are automatically lowered, one at a time, onto the uppermost surface of the tumtable, or onto the uppermost surfaceof any uppermost records at the time disposed on the turntable, for reproduction by the phonograph reproducer adapted to traverse and reproduce the records during the playing thereof,

It is an object of my invention to provide an improved mechanism of the above type which,

may be economically manufactured, and which is of sturdy and reliable construction, and which will operate over long periods for a great numberof operations, without the necessity of readjustment of any of theparts.

Another object of my invention is to provide an improved mechanism of the above type, wherein improved record supporting and lowering means is provided to more reliably lower one of the records of a stack of records supported thereby, and without the liability of damage to records of the supported stack even though these may vary slightly in diameters and in edge portion thicknesses, and in the form of the edges.

Another object of my invention is to provide improved supporting and record discharging means, as set forth in the previous object, wherein a plurality ofsaid supporting means may co-' operatively support a stack of records and lower one of said records at a time, as desired, in

sequence.

Another object of my invention is to provide a mechanism achieving the aforesaid objects, and wherein said plurality of means may be readily and quickly adjusted by an operator to accommo-, date records of different standard sizes.

Another object of my invention is to provide an improved phonograph mechanism of the general type above referred to, and whereby the required movements of the tone arm at the conclusion of the playing of one record and prior to the playing of the next record, and the required movements of the record supporting .and discharging means, may be expeditiously effected.

Another object of my invention is to provide a mechanism achieving the preceding object, and wherein the operation of the said parts may be efiected at the proper times by power transmitted through a power take-off of the phonograph mechanism, deriving its motion by' a friction drive means engaging the phonograph turntable,

Another object of my invention is to provide, for phonograph record changing mechanisms of the type having record supporting means comprising a plurality of sets of arcuately movable blades, each set mounted on a post disposed laterally of the phonograph turntable, and wherein said blades support a stack of superposed disc records above a turntable and upon arcuate movement of the blades to release a lowermost record of the stack to the underlying turntable improved adjustment means for said supporting means to position said sets of blades to predetermined varying distances laterally from the axis of the stack of records, and operating in an improved manner to insure that a line extending between the axis of movement of said blades and the stack axis will traverse the vertical plane of the same portion of said record supporting means, in all laterally adjusted positions of said supporting means, thereby-insuring the same timed cooperative contact between said blades and stacked records of one size for which said supporting means is pre-adjusted as for another size of records for which said supporting means may be re-adjusted.

Another object of my invention isto provide, in an automatic record changing mechanism of the type described, improved means for automaticallyeifecting timing and movement in sequence of the tone arm out of the path of descent from a stack of records disposed in spaced rela-' tion above a record supporting turntable, the release of records for said turntable from said stack, and the placement of the reproducer needle of the phonograph in starting position with the initial outermost groove of an uppermost record on said turntable.

Another object of my invention is to provide, in an automatic record changing mechanism of the 'type described, improved means for auto matically effecting timing and movement in sequence of the tone arm out of the path of descent from a stack of records disposed in spaced relation above a record supporting turntable, the release of records for said turntable from said stack, and the placement of the reproducer needle of the phonograph in starting position with the'initial outermost groove of an uppermost record on said turntable, and the further provision of additional improved means, operated by the aforesaid improved means, for supplying a resiliently effected inward impulse to the tone am line -6 of Fig. 4;

the uppermost record on'the turntable, to cause said needle to glide over said border portion until it engages the initial groove of thesaid uppermost record'to be reproduced.

Other objects of my invention and the inven-- tion itself will become apparent by reference to the accompanying description and the drawings hereof, illustrating an embodiment of my invention, whereof ancillary cooperative apparatus of one form ,of apparatus with which my invention may be employed is illustrated in my co-pending application for patent, Serial No. 312,839, filed January 8, 1940, for improvements in Phonograph record changing mechanisms;

Referring to the drawings hereof:

Fig. 1 is a top plan'view of the phonograph and record changer unit of my invention, certain parts being broken away, showing the condition while a record is being played;

Fig. 2 is a fragmentary plan view showing certain of the parts of Fig. 1 at the conclusion of the record;

Fig. 3 is a fragmentary vertical sectiontaken on the line 3-3 of Fig. 1;

Fig. 4 is a bottom plan view; Fig. 5 is a vertical section taken on line 5-5 of Fig. 4;

Fig. 6 is a fragmentary section taken on the Fig. 7 is a view similar to a part of Fig. 4, but with the lower frame plate removed.

a Fig. 8 is a section taken on the line 8-8 of Fig. 7, but with certain of the parts rotated into 'the plane of the section which would not otherwise appear; and

Fig. 9 is a perspective view of the kick-in spring of my invention.

The drawings illustrate a preferred embodiment of myinvention; and in the differentiflgures of drawings like parts are designated by like referenoe characters.

Referring to the embodiment illustrated in the drawings, the numeral l0 indicates abase plate upon which are mounted the turntable, tone arm,

I and record changing mechanisms of my invention, the entire unit being adapted for mounting in a suitable cabinet by means of the bolt holes II.

A synchronous motor l2, Fig. 4, with its associated speed reduction unit I3, is mounted below the base plate by means of the bolts, Hi, the unit I3 carrying the elongated record spindle I5 which in turn supports and drives the turntable A power take-01f at the rim 2| of the turntable drives the mechanisms which lift the tone arm at the conclusion of a record, swing it off to the side, and return it to. the succeeding record, and which drop the succeeding record into place from the stack, which supported above the turntable as later described. As illustrated in Fig. 1, arubber-tired wheel 22 is adapted to .engage the inner periphery of the turntable rim and to be rotated thereby when so engaged.

The wheel 22 is mountedon a spindle l8 which projects through an elongated opening IS in' the base plate l0, and is carried bya speed reducer housing 24,Figs. 1 and 9. The housing 24 may be oscillated about a'vertical shaft 25 and thus the wheel 22 may be swung into and out of engagement with. the rim 2| under control of mechanism associated with the tone arm and to be later described. 'Withinthe housing 24.the spindle l8 carries a worm 26 driving a worm wheel 21 on a shaft 28. Near its opposite end, as illustrated in Fig. 8, the shaft 28 is formed as a worm "29 and drives a worm wheel 30 rigid with the shaft 25, before '3l bolted as at 32 beneath'the base plate It). De-

pending, integral legs 33 of the plate 3| support a lower plate 34 which carries the bearing for the lower end of the'shaft 25. I

Also journalled in the upper andlower. plates is'a hollow shaft 35, Fig. 5, which projects upwardly through the base plate 10. Clamped to the upper end of the shaft, by means of a bolt 36, is a block 31 having depending cars 38. These ears support the pivot pins 39 of the tone arm 40. The tone arm normally rests on the record in the usual manner, but may be swung upwardly by the upper end of a rod 4|, slidable within the hollow shaft35. The lower end of the rod is engaged by a rocker arm 42 pivoted at 43, Figs. 5 and 6,

the cam and allows the rod 4| to drop free of the tone arm. At the conclusion of the record, however, the power take-off is initiated and the cam is revolved, rocking. the arm 42 to lift the rod 4| and thereby lifting the tone arm from the record. The tone arm remainselevated, due to the second lull 46 of the cam, until the operations of swinging it aside and back again, and of record changing, have been completed.

The swinging of the tone arm in an outwardly direction is accomplished by means of a cam 41 rigid with the shaft 25. Pinned to the tone arm shaft 35, Figs. 5'and 7, is a cam follower 48 which is engaged by the cam 41 immediately after the tone arm has been raised. The cam is so formed as to swing the follower 48, and therefore the .tone arm, until the latter is free of the largest the stacksupporting posts, as later described. It

will s uflice at this time merely to say that the positioning of the posts rotates an arm 5|, Fig. 4, into either of two positions. A pin 52 in this arm is embraced by a slot in an arm 53, the integral hub of which may rotate on a stud 54 fixed to the lower plate 34. The lower face of the hub isformed as a cam 55 which co-acts with a complementary cam on the hub 56 of -a, fork 51. The fork is slidable on the stud 54 and is urged upwardly, by a spring 58, against the cam 55, the upward movement. of the latter being limited by the bead of the stud. Thus, when the adjustment is made for a twelve-inch record, the arm 5| and, therefore, the arm 53 are in the full line position of Fig. 4, and the cam 55 forces the fork, 51 to its lower posltion. With conditions set for ten-inch records, the arm 53 'will be in the broken line position and the cam will allow 318 spring 58 to raise the fork to its upper posion. l

During normal playing operation of the Slidably keyed to the tone arm shaft 35, Figs. and '7, is the hub 59 of a cam follower lill which may engage either of the cams 49 or 50, rigid with the shaft 25, as determined by the vertical position of the fork 51 which embraces a groove in the hub 59. The follower 60 extends to the side of the shaft opposite thefollower 48, previously described, and hence rotates the shaft 35 and the tone arm to return the latter from its outer position.

As seen in Fig. 7, the cam 50 is so formed as to be free of the follower 60 during most of its revolution. At the proper time, however, the portion SI of the cam engages the follower and by continued rotation forces -it outwardly, relative to the shaft 25, until the needle of the tone arm is brought inwardly, relative to the turntable, to a point above the rim 1' of the twelve-inch record, illustrated in Fig. 1. At this time the follower 6B encounters the lull 62 of the cam and rotation of the tone arm ceases while the mechanism previously described, including the cam 44, rocker arm 42, and rod 4|, allows the needle to descend and rest upon the record.

When operating with ten-inch records the tone arm must, of course, be returned a greater distance to reach the rim of the record and therefore the cam 49, at which the follower 60 is positioned in this case, is sufliciently larger than the cam 50 to produce the additional rotation of the follower. A lull 63 of the cam 49 allows the rotation of the tone arm to cease, as did the lull 62 of the cam '50.

Due to slight variations in dimensions of records on the market, it would be impractical to engage the needle directly with the start of the playing groove by any positive means. It has been found that the desired result may be obtained more satisfactorily by allowing the needle to rest upon the smooth annular surface at the rim of the record and then imparting a slightimpulse tothe tone arm to cause the needle to glide inwardly over the surface until it encounters the groove. In the present invention this result is obtained by the device about to be described.

Secured to the cam assembly, as illustrated in Figs. 7 and 8, by means of a screw 64, is a lightspring-metal element 65 which comprises a unitary formation of springs 49 and 50', which are associated with cams 49 and 5|], respectively. As shown in Fig. 9, the springs are formed as nar row, curved strips arising from, and supported by, the common base portion 56. The height of the base portion is such that the edge 61 will contact the lower face of the cam above it, as seenv in Fig. 8, and thus effectively restrain the element from displacement.

The bodies of the cams 49 and 50 are so re- I cessed as to accommodate the springs, the free ends of which project beyond the ends of the lulls 62 and 63 a considerable distance in a circumferential direction and slightly in a radial direction.

As previously described, the tone arm comes to rest when the cam follower 60 is at the radial distance of the lull 62 from the center of rotation of the shaft 25. As the cam assembly continues its rotation the follower encounters the spring lead 50. Due to the inertia of the tone arm and its associated parts, and the static friction of the tone arm shaft 35 in its bearings," the follower remains stationary and the spring 50 is flexed inwardly by it. The parts at this time are in the position illustrated in Fig. 7. This fiexion of the spring is gradually increased as the cam assembly revolves, due to the oblique'extension of the spring, until the force is sufficient to overcome the inertia and static friction previously mentioned."

The cam follower 60 is then started outwardly and as the static friction gives place to the lesser dynamic friction, the tone arm is thrown gently inwardly and its resultant momentum is sufficient to keep it moving until the needle glides into the playing groove, but insufficient to force the needle from the first convolution of the groove immediately upon contacting the record,- the spring 49' or 50' will merely wipe across the cam follower 60 without moving it and dislodging the needle. from the groove, as would be done were a positive means used to throw the needle inwardly.

During the interval in which the tonc arm remains at its outermost position a record is dropped from a previously arranged stack S onto the turntable. The mechanism which supports the stack and drops the individual records at the proper time is the same as that shown in my co-pending application, Serial Number 312,839, filed January 8, 1940, where it is more fully described and the novel features are claimed.

Briefly, it consists "of two posts 10 and 1! at diametrically opposite corners of the base plate In, as seen in Fig. 1, each provided with a vertical shaft 12 carrying at its upper end a hat plate 13, the inner edge portion of which is slightly within the periphery of the record and thus serves as a support. Upon partial rotation of the shaft, the support is removed and the record is free to drop, the remainder of the stack being supported by a curved tongue 14 which enters the stack above the lowermost record. The partial rotation of the shafts i2, and their subsequent return, are produced by mechav as seen in Fig. 5. A normally retractable pin 33,

carried by the post, may enter eitherof two holes in the base plate and a pointer 81 registers'with suitable indicia such as the inscr bed buttons 88 and 89 on the base plate to facilitate the correct placing of the post by the operator.

A crank 90 at the lower end of the shafu'lz projecting below the base pate, is linked by a bar 92 to one arm 94 of a bell crank 95 free y pivoted on the boss 8!. A second arm 91 of the hell crank is linked by thebar 99 to a rocker arm Hill. This rocker arm. is rotatably mounted on a post illi carried by the frame plates 3! and 34 and adapted to be swung by a roller pin M3 on a disc l4 rigid with the shaft-25. A spring ing depending ears I34 and I35.

rubber bumper I00, and the plate I3 in stack tends in .an oblique direction from the base of supporting position. During rotation of thefshaft' 25, by the power take-oil, the pin I03 engages the edge I02 of the rocker arm and rocks it in a clockwise direction as viewed in Figs. 4 and .7. This, through the linkage 9099, rotates the shaft I2 to drop the record as previously described. When the rocker arm rides off the pin I03 the spring I05 returns the parts to normal position. h H

The post II is provided with an identical stack support I3, shaft I2, crank 00, and link 92, as those of the post I0. The link 92 is pivoted'to an arm I01 of a bell crank I08 freely pivoted on the boss |a of the standard 80a. The other arm I00 of the bell crank is linked by the bar.

I'I0 with a third arm III of the bell crank 95. The dimensions and angular placement of these various parts are such, that the two stack supporting units are given equal degrees of rotation by the rocker arm I00 and thus both supported points of the record are released simultaneously.

A bar II3 links a boss II on the standard 00 with an arm ,I I2 splined to the boss 8Ia of the standard 80a. The pivots of the link H3 and those of the standards 80 and 80a define a parallelogram and hence the post" always assumes a position corresponding to, and diametrically opposite, the post 10. 1.

Coming now to the mechanism which initiates the power take-off to produce the movements previously described, it will be seen that the reducer housing 24, which carries the rubber-tired wheel 22, is provided with an upstanding lug I30, best seen in Fig. 3. .At the completion of a record thetone arm has swung inwardly to the position illustrated in Fig. 2, and during'the interval in which the needle is following the last few convolutions of the groove a spring plunger I3 I, associated with the tone arm, contacts the lug I30 and urges'the wheel 22 against the turntable rim 2I.

As illustrated in Fig. 5, the shaft35 carrying the tone arm is provided with a depending skirt I32 concealing the shaft bearing. To this skirt is welded, or otherwise secured, an arm I33 havplunger I3I slides in a square opening in the ear I34 and has'threaded into it a screw I36 sliding in the ear I35 and provided with aknurled head I3'I for adjustingthe time at which the plunger contacts the lug I30.

A spring I30, compressed between the inner end of the plunger- I3I and the ear I35, urges the plunger outwardly, limited by the knob I31,

with sufficient force to hold the wheel 22 indriving engagement with the turntable As previously described, the rotation of the wheel 22, acting thruogh the speed reducer 23-30, rotates the shaft-25 andeflects, among other results, the swinging out of the tone arm. Thus the'contact ofthe plunger I3I and lug I30 only initiates the power take-oil and so other means are provided to-maintain the drive until' the cycleis completed.

A rocker arm I40 is pivoted on the post, IOI, previously mentioned. The end I of the rocker arm is-formed as a cam follower adapted to engage the periphery of the disc I04 which is rigidwith the shaft 25 and the periphery of which is concentric with the shaft except for a notch I42. The leading side I43 of this notch, with reference to the rotation of the disc, is substantially radial while the trailing side I44 exsaid I43 until it rejoins the circular periphery.

The end of the rocker arm I40 opposite the cam follower I 4| carries an adjustable screw I45 so arranged as to press against the housing 24- when the follower MI is in engagement with the concentric portion of the disc I04 and so to hold the wheel 22 against the rim 2 I. I

Normally, that is, while the powertake-ofl is idle, either during playing operation. of the phonograph or idleness of the machine,.the i'ollower I4I projects into the notch I42 and the The square screw I45 allows the wheel to remain free of the turntable rim. Upon initiation of the power take-oil by other means, however, the disc I04 is rotated in the direction of the arrow in Fig. I;

and the surface I44 earns the rocker arm in a counter-clockwise direction, as viewed in'Fig. "I, to contact the housing 24 and maintain the driving engagement. After a complete revolution of the shaft 25 has occurred, the follower I4I drops into the notch I42, swinging the rocker arm clockwise and allowing the wheel 22 to leave the rim 2I, as it does when unhindered, by reasons of the placement of the pivot shaft 25 ahead, with referenceto the turntable rotation, of a radial line through the turntable shaft and the point of engagement of wheel and rim.

An additional means for initiating the power take-off is provided by the manual starting lever I50 which, as illustrated in Fig. 1, is pivoted to the base plate I0 at I 5I. The end I52 of the lever projects beyond the turntable and records so as to be conveniently moved by the operator. The opposite end portion I53 is adapted to bear against the spindle I3 ofthe wheel 22 and, given upon the spindle so as to rest upon the posts.

The motor is then started by means of the switch I on the base plate. The starting lever I50 is rocked by the operator, engaging the power takeoff which then establishes its own maintenance by means of the cam I04 and rocker arm I40. The tone arm is now raised by the rocker arm 42 and is swung to its outermost position by the cam 41 and follower 43. The pin I03 engages the rocker arm I00 andcauses the linkages below the base plate to rotate the stack supports to drop theflrst record, I

' The cam follower 60 ,now engages. the 'approthe rocker arm 42 and rod 4|! The spring 40' .or 50' now imparts an impulse to the tone arm and the needle glides over to engage the playing groove, which it is now free to follow. The notch in the cam I04 arrives atthe cam follower I and the driving engagement .for the power takeoff is terminated.

The record is now being played. Near the conclusion the tone arm has swung inwardly far enough for the plunger I3I to contact the lug I30 and'continued movement presses the wheel 22 into engagement with the rim 2I and the next cycle of operation is begun in which the second record is dropped and subsequent ones follow in the same manner until the stack is exhausted. After that the record supports 13 rotate idly and the tone arm returns each time to repeat the last record until the motor switch is finally opened by an operator. The supporting posts and H are then moved outwardly and the accumulated records may be removed from the machine.

It will be noted that the improved record changer of the present application differs from that of mypreviously mentioned application, Se

' rial No. 312,839, filed January 8, 1940, in that herein all movements of automatically operated controlling mechanism are effected by power derived from the power take-oil. mechanism comprising the friction wheel 22. It is moreover noted that in the present application, improved means are provided which are in like manner applicable to the'improved mechanism of my said former application, consisting in the provision of the resilient camrnirig elements 49' and 50" carried by the cam mechanism of Fig. 7, whereby a resiliently applied force is communicated by the leaf spring 49' or-50', to cause the needle of the reproducer, which has previously been lowered to the border portion of the record, to glide over said border portion to engage the playing groove of'the uppermost record at the time disposed onthe turntable, thus accurately ensuring proper initial positioning of said needle in saidgroove at the start. of a record playing period.

Said improved spring means are also applicable to record changing mechanisms of varying I designs, such asthe mechanism of my co-pending application'serial No. 312,839, filed January 8, 1940, and of my cc-pending application Serial No. 326,195, filedMarch- 27, 1940, and I there fore claim this improved mechanism in adequate scope to cover its incorporation in any record changing mechanism to which it may be adapted.

I am aware that many other, numerous, and extensive departures may be made from the embodiment of my invention disclosed herein, or disclosed in either of my said co-pending applications. and within the purview of the present invention.

I claim:

1. In an automatic record changer of the type 1 wherein records are consecutively transferred from an upper stack of records to the turntable by rotative reciprocating movement of uniform extent of spaced fingers movable to engage and disengage the peripheral portions of lowermost records ofthe stack to consecutively lower the lowermost of said records to a lower record supporting turntable, and provided with a tone arm mounted to swing over said turntable, the combination with laterally disposed sets of said finments each adapted to be selectively engaged with an element of said tone arm-said elements being variably so formed as to advance said tone arm from an outward inoperative position to dif- 5 ferent distances inwardly over a record carried by the turntable, and common manually adjustable controlling means adapted to be preset to any of a plurality of different adjustment positions to correspond to the diameter of records to m be played, to simultaneously adjust each of said finger supporting means for a given size of record and to operatively associate the particular rotatable tone arm advancing element with said tone arm element to move the ,tone arm the dea 15 sired distance corresponding to the same size of record as predetermined by the adjustment of said common controlling means. a 2. The record changer mechanism substandaily as set forth in claim 1, characterized by said rotatable elements each comprising a yieldable leaf spring having an outer surface generally in the form of a cam engaging said tone arm element by a wiping outwardly camming contact, each of said leaf springs rotatable about a common axis adjacent its fixed end, and extending rearwardly curvilinearly outwardly by its free end to different radial distances with re- 'spect to said axis.

3.. In an automatic record changer of the type wherein records are consecutively transferred from an upper stack of records to the turntable by rotative reciprocating movement of uniform extent of separate pairs of laterally disposed spaced fingers movable to successively 'engage and disengage the upper and lower peripheral surfaces of the lowermost record of said stack to successively lower the lowermost of said records to a lower record supporting turntable, said turntable .being in a plane parallel to the plane not said stack of records, and provided with a tone arm mounted to swing over said turntable, the combination with said laterally disposeds'ets of fingers, turntable and tone arm, of means to 5 adapt said changer for the playing of records of any. of a plurality of different diameters comprising finger supporting means for each set of fingers adapted to be simultaneously adjustably moved laterally of the stack to. efl'ect. like peripheral engagement by corresponding pairs of the fingers of each set with stacked records of any of a plurality of diflerent diametrical sizes, tonev arm advancing means comprising a plurality of rotatable elements each adapted to be selectively engaged with an element of said tone arm, said elements being variably so formed as to advance said tone arm from an outward inoperative position to different distances inwardly over a record carried by the turntable, and common manually adjustable controlling means adapted to be pre- 0 set to any of a plurality of different adjustment positions to correspond to the diameter of the record to be played and to simultaneously adjust each of said finger supporting means for a given f size 'of record and to operatively associate the particular rotatabletone arm advancing element with said tone arm element to move the tone u'm thedesired distancecorresponding to the she-of the record.

LEE B. GREEN.

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