US2544230A - Automatic phonograph - Google Patents

Description

March 6, 1951 i F. M. JOHNSON AUTOMATIC PHONOGRAPH 8 Sheets-Sheet 1 Filed Nov. 5, 1945 ,4 T TQIQNEY March 6, 1951 F, sd 2,544,230

AUTOMATIC PHONQGRAPH Filed Nov. 5, 1945 8 Sheets-Sheet 2 INVEN TOR. QqA/K J el-v 50M March 6, 1951 F. M. JOHNSON AUTOMATIC PHONOGRAPH 8 Sheets-Sheet 3 Filed Nov. 5, 1945 kffismwvf I N VEN TOR. FEHNK JOHN 501v B Y A TTOENE Y March 6, 1951 F. M. JOHNSON AUTOMATIC PHONOGRAPH 8 Sheets-Sheet 4 Filed Nov. 5, 1945 INVENTOR.

FkqA/K JON/V5.2 BY

k N wm ,4 T TOIQ/VEY Filed Nov. 5, 1945 8 Sheets-Sheet 5 March 1951 i F. M. JOHNSON 2,544,230

AUTOMATIC PHONOGRAPH 4 INVENTOR. FRHNK H/vso1v 8 Sheets-Sheet e F. M. JOHNSON AUTOMATIC PHONOGRAPH March 6, 1951 Filed Nov. 5, 1945 UQ MFQQQN March 6, 1951 JOHNSON 2,544,230

AUTOMATIC PHONOGRAPH Filed Nov. 5, 1945 8 Sheets-Sheet 7 INVENTOR. WWVK M H/vso- March 6, 1951 F. M. JOHNSON AUTOMATIC PHONOGRAPH 8 Sheets-Sheet 8 Filed Nov, 5, 1945 A TTO/ZNEY Patented Mar. 6, 1.951

UNITED STATES PATENT OFFICE AUTOMATIC PHONOGRAPH.

Frank M. Johnson, New York, N'. Y., assignor to Universal Camera Corporation, New York, N. Y., a corporation of Delaware Application November 5, 1945,. Serial No. 626,732

cause the least possible strain and shock to the records.

It is a further object of this invention to providein a phonograph of the character described a mechanism which effects a quicker change from one record tothe succeeding record than is attained by other mechanisms of this general type whereby to enhance the effect of continuity in the playing of records.

It is an additional object of this invention to provide in a phonograph of the character described a mechanism which will detect the end of a record positively, accurately, and with a minimum time delay.

Still another object of this invention is to eliminate the error in detecting the end of a record, which error is due to the eccentricity of the record spiral with respect to the center of rotation of the turntable.

Still a further object of this invention is to provide a phonograph of the character described, the elements of which are so constructed and arranged that the phonograph is durable and eflicient in operation and comprises. relatively few and simple parts which can be fabricated and assembled economically.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

The invention accordingly consists in the features of construction, combinations of elements and arrangement of parts which will be exemplified in the construction, hereinafter described, and of which the scope of application will be indicated in the appended claims.

Certain features of the invention herein shown and described, but not claimed, are shown, described andclaimed in my co-pending application Serial No. 590,202, filed April. 25,, 1945..

In the accompanying drawings in which is shown one of the various possible embodiments of my invention,

Fig. 1 is a vertical sectional view through a phonograph embodying the invention, the same being taken substantially along a plane running through the centers of rotation of the turntable and the tone arm;

Fig. 1a and lb are schematic views showing various positions of the operative parts of the mechanism for transferring a record from the stack to the turntable;

Fig. 1c is a fragmentary top view of the phonograph showing the stack leveler in playing position;

Fig. 2 is a vertical sectional view through said phonograph taken substantially along a plane at right angles to Fig. 1 and running through the center of rotation of the tone arm;

Fig. 3 is a fragmentary auxiliary sectional view of the mechanism for determining the end of a record and starting the record changing and tone arm moving cycles;

Figs. 3a, 3b, 3c and 3d are schematic views showing various positions of the operative parts of the mechanism for determining the end of a record;

Figs. 4, 5, 6 and 7 are schematic views showing various positions of the operative parts of the discriminating mechanism for setting the tone arm in the starting, grooves of records of different fixed diameters;

Figs. 8 and 8a are enlarged, sectional views taken substantially along the line 83 of Fig. 1 and showing various positions of certain operative parts of the discriminating mechanism and of the mechanism for determining the end of a. record;

Fig. 9 is an enlarged fragmentary top plan view taken substantially on the line 9-9 of Fig. 1 and showing the driving and timing means for the record changing and tone arm moving mechanisms; and

Fig. 10 is an enlarged sectional View taken substantially, along the line Iii-l0 of Fig. 1 and showing the driving means for the record transferring mechanism.

Referring now to the drawings, there is illustrated a phonograph embodying the invention andcomprising a turntable l secured to a hub 2 which is mounted forrotation about a stationary central post 3 and is seated on a thrust bearing 4. The turntable. is driven by conventional means, such for example as an electric motor 5 which, through a suitable reduction train, turns a disc 5A covered with friction material, for instance rubber, which engages the inside of the. downturned peripheral rim of the turntable, thus providing a frictional. rim, drive.

The record magazine of a commercial record disc, so that it can be slidingly received therein. At its upper end the central post has an inset step 3A cut therein. Said upper end, further, is provided with an erect cylindrical extension 33 whose axis is ofiset from the axis of the post 3. The diameter of the extension is considerably less than that of the post, being sufiiciently small to be rotatably received in the internal longitudinal offset bore of a cylindrical cap 6. Said cap has a diameter the same as that of the central post, so that it may be turned about the cylindrical extension 33 to a position in which the axis of the cap is coincident with the axis of the post. The eccentricity or offset of the axis of the projection 3B and that of the cap 6 is such that when the cap is turned 180 away from the position in which the axis of the cap is aligned with the axis of the post, a portion of the surface of the cap will be approximately in registration with the riser of the inset step 3A at the top of the central post. The height of said riser is slightly greater than the thickness of a commercial record at its center, but is less than the thickness of two records at their centers. Free rotation of the cap 6 is limited between these two positions by a pin I mounted on the reduced cylindrical extension 3B and mating with a slot in the cap.

When it is desired to load records in the magazine, the cap 6 is rotated to align a portion of its surface with the riser of the step 3A. Now records can be deposited on the cap and these records will descend no further than the tread of the step. After records have been played, the central cap 6 is rotated 180 to the position in which it is coincident with the central post. Now there is no bend, overhang, step or projection to prevent a straight lift in the removal of the played records.

The mechanism for leveling records in the stack The stack record-leveling mechanism consists of a main arm 8 rotatably secured by a pivot SA on a bracket I fixed to the phonograph support S. Said arm extend beyond the central post 3, and. the free end thereof rests on the top surface of the top record in the stack. The main arm has a slot 83 in which there is freely received the central post 3 whereby said main arm is diametrically located with respect to the records in the stack. Said leveling mechanism also includes a secondary arm 9 aligned with and pivotally mounted on the main arm 8 at a point between the central post and the bracket ll]. One end of the secondary arm rests upon the top of the central post cap 6, and at its pivot point the secondary arm is resiliently urged upwardly by means of a biasing leaf spring 9A. The lengths of the two arms and the positions of their pivotal mounting points are so proportioned that the bottom ends of both arms are always at substantially the same horizontal level. In this manner, the main arm 8 urges the records down on one side of the central post until the secondary arm 9 contacts the record stack to prevent further downward movement of the main arm, thus maintaining the record stack level. In the illustrated embodiment of the invention, such proportioning is attained by pivoting the secondary arm midway between the pivot point 8A and the free end of the main arm, and by having the pivoting point of the secondary arm midway between the central post 3 and the bottom end of the secondary arm.

The mounting bracket ID has a loading blade l2 fixed to its base, and said bracket is pivoted on a 'screw l3 which is fixed to a pedestal secured to the phonograph support S. The loading blade extends at an angle of about to the main record leveling arm 8, so that when said arm is in position to level the records in a stack, the record loading blade I2 is clear of the largest diameter disc which the phonograph is adapted to play. Such position of said blade is shown in Fig. 1c. The loading blade is long enough to support the smallest diameter record which the phonograph is adapted to play at such time as said loading disc is in operative position.

When a set of records is to be placed into position vertically spaced above the turntable, the leveling arm is raised and rotated 90 clockwise from the position shown in Fig. 10. This causes the loading blade I2 to project towards the central post, said blade then occupying the position indicated by the dot and dash lines in this figure. At such time when records are loaded on the cap 6 (which has been rotated to eccentric position), the lowermost record will be supported at its center on the step 3A and adjacent its periphery on the loading blade l2. After all the records to be played have been placed on the cap 6, the operator places his hand upon the top record and holds the stack of records level. Now the leveling or the main arm 8 is swung counter-clockwise a quarter of a turn to swing the loading blade l2 out of the way and place the leveling arm in proper angular position for operation. Then the leveling arm is swung downwardly about pivot 8A until the center post cap 6 is received in the slot 8B. The main and secondary arms are then allowed to fall until the two arms press down in a common horizontal plane on the top of the uppermost record in the stack. The main arm 8 is resiliently urged downwardly by means of a helical tension sprin I I.

The cycling mechanism To start the operation of the record-lowering mechanism, a reject button I4 is pressed. This button is slidably mounted on the phonograph support S and is biased outwardly by a spring I5.

'= Pressing said button shifts a slide bar [6 whose forward end has a depending finger. In the advanced position of said lever, this finger engages the lower end of another lever I! which is rotatably mounted by a pivot IS on a cycle disc 20. Advance of the lever l6 turns the lever I! about its pivot in a counter-clockwise direction, as viewed from Fig. 2, causing the upper end of the lever to project a substantial distance above the cycle disc. The position assumed by the lever I1, when moved by pressing of the reject button I4, is illustrated in Fig. 3d. The cycle disc 20 is secured for rotation to a cycle shaft 28 which is journaled in a pair of bearings 29, 30 mounted on brackets 3|, 32 which are dependent from the support S. Said cycle disc has a peripheral notch 20A which, in normal position of the phonograph, i. e. during playing of a record, is uppermost. The axis of revolution of the cycle disc intersects the axis of revolution of the central post 3, and

' said notch is so disposed that in normal position of the phonograph the same i registered with the hub 2 of the turntable. Said hub has a friction element, such as a rubber tire 2 I, carried thereon, the tire being of a diameter sufliciently large to cause the same to project into the notch 29A of the cycle disc. Thus when the phonograph is played, said tire will rotate freely, even though a portion of the same extends within the plane of cycle disc (as is seen in Fig. 9). The hub 2 has a pin {9 (Figs. 1, 3, 3a, 3b, 3c and 3d) amazes on its undersurface, having a vertical side wall which, during travel of the pin with the turntablawill traverse the position occupied bythe raised upper end of the lever I! when said lever is in the position illustrated in Fig. 3d, this position being that which the lever is caused to assume upon operation of the reject button [4. When the vertical side wall of the pin [9 engages the raised upper end of the lever I I, there will first be a tendency to turn said lever about the pivot W. This motion, however, cannotbe obtained because the lower end of the lever rests against a stop WA on the cycle disc. Consequently, engagement of the lever I! by the pin l 9 causes the cycle disc to rotate in a counterclockwise direction, as viewed in Figs. 3a and 3d. The upper end of the lever I I and the vertical side wall of the pin iii are so designed that they will remain in engagement until the cycle disc has been angularly turned at least a distance sufficient to cause the rubber tire 2| to engage the unbroken surface of the cycle disc. After such time the rubber tire will drive the cycle disc until the notch 20A is again reached. In the foregoing respect the cycle disc may be considered as a one-revolution clutch. Revolution of said cycle disc drives the various operating mechanisms, hereinafter described, in proper timed relationship. It may be mentioned at this time that the cycling mechanism comprising the cycl ng disc is driven from and by the turntable, andthis construction in general obtains a very rapid cycle and employs an extremely small number of parts.

The record-lowering mechanism The cycling disc has a pin 22 (Figs. 1 and secured to the same for rotation therewith. This pin has a reduced portion thereof slidably received in a slot in a flat lever 23 which is pivotally mounted on a bracket 24 pendant from the support S. The lever 23 includes a second slot in which there is slidably received a second pin 23A which is fixed in a selector slide 25. As the pin 22 rotates with the cycle disc, it causes the lever 23 to oscillate about its pivotal mounting point on the bracket 24, and as this lever oscillates, it moves the selector slide 25 up and down. Said slide is constrained for vertical movement by mounting on the central post 3. The sl de carries an elongated non-circular selector rod 26 which rides in a groove 26A of matching contour in the central post 3. Thus it will be seen that as the cycling disc rotates, it causes the rod 26 to vertically reciprocate. A selector dog 21 is pivoted on top of the selector rod 25' and moves up and down with said rod. Said dog is slender enough to fit entirely within the groove 26A. In addition, the right-hand side of the dog (as viewed in Fig. l) is rounded and is adapted to engage the cammed upper end 263 of the groove 26A when said dog is in its uppermost position, for a purpose which will be explained hereinafter. Finally, the left-hand side of the dog (likewise as viewed in Fig. 1) has a step 21A formed therein. This causes the tip of the dog to be pointed. The dog operates as follows: Assume the uppermost record on the turntable has just finished playing. The cycle disc starts to turn. At this instant the selector rod 26 is in its lowermost position with the dog 21 disposed below the level of the turntable. Rotation of the cycle disc initially causes the rod and dog 2'! to rise, The dog may be pivotally mounted in such manner that at this time the center of gravity of the dog is to the right of the pivotal mounting whereby the dog will naturally stay in anerect position as it is elevated. When the dog nears its uppermost position, its

- tip will already have been projected into the center aperture of the lowermost record in the stack. Engagement of the right-hand side of the dog with the cammed surface ZEB now tips the dog over to the left, causing the riser of the step 21A to engage the inside of the hole in the record. Further upward movement of the dog presses the dog more to the left and causes the lowermost record in the stack to be shifted to the left. The dog and its step are so proportioned that the record will be shifted to the left, enough to align its central hole with the axis of the central post 3. When the record is in this position, the tip of the dog will project beyond the groove 26A, such position being illustrated in Fig. la. At this time the cycle disc is rotated approximately and further rotation of the disc will cause the dog to descend. As the dog descends, the lowermost record will come down with it, said record being centrally supported on the step 21A (see Fig. lb) so that said record does not experience a free fall, but rather has a controlled drop and thus prevents clatter, breakage or chipping of the record. As the dog re-enters the central hole in the hub 2, it will be straightened out and once more forced back into its idling position as shown in Fig. 1. Thus the dog is repositioned and ready to operate on the next cycle for the lowering of another record from the stack to the turntable.

The tone arm positioning mechanism From the time that the playing of one record is finished to the time that the succeeding record is started, the tone arm must rise from the played record, be swung clear of a descending re ord regardless of its diameter, return to a position over the starting groove of the lowered record, and. then lowered to engage the needle into the starting groove of the said record, regardless of its size. Pursuant to a feature of the invention, the automatic phonograph is capable of playing re"ords of a plurality of predetermined but different diameters. Basically, said phonograph may be construct d to play records of any number of different fixed diameters. However, in the embodimmt of the invention illustrated herein, the phonograph is shown as being adapted to play records of only two different diameters, it being understood. that the phonograph may be modified in accordance with the underlying principle described herein to accommodate records of a greater number of different fixed diameters. In general, the tone arm is conditioned to be set in the starting grooves of records of different fixed diameters by means of a detector mechanism hereinafter described in detail. This detector system does not operate when records of the smaller size are played and functions only to control the position of the tone arm upon the playing of records of the large size. Accordingly, the tone arm positioning mechanism will be discussed without the detector system at the present time in order to explain its general construction and operation. Rotation of the cycle disc 28 causes rotation of the cycle shaft 28 which, as has already been mentioned, is secured at one end thereof to the cycle disc. Affixed to the opposite end of the cycle shaft is a lift cam 33 (Figs. 1 and 2) which engages a lift pin 34. This pin is mounted for free vertical movement and for free rotation about a vertical axis. Movement of the pin is otherwise constrained. At its upper end the pin 34 is pivotally fixed. to the tone arm T in such manner that said pin will rotate about its vertical axis with movement of the tone arm about the same axis, and that the pin will move vertically upward and downward with the rotation of the tone arm about a horizontal axis. At the rear of the tone arm is a shelf 35. A roller 36 is rotatably mounted on a bracket 31 fixed to the support S. Said shelf and roller limit the rise of the rear of the tone arm. As the lift cam 33 rotates with the cycle disc, the lift pin 34 is elevated, causing the engagement of the shelf 35 with the roller 36. Continued rise of the lift pin causes the tone arm to rotate about a horizontal axis in a clockwise direction, as viewed from Fig. 1, thus lifting the needle N clear of the played records. The amount of lift can be adjusted by varying the height of the bracket 21. This height of the tone arm is maintained by proper shaping of the cam 33 until near the end of the cycle when the pin 34 engages the depressed surface of the cam 33 and causes lowering of the pin, and hence lowering of the needle.

Horizontal rotation of the tone arm is caused by cam 38 (Figs. 1, 2, 8 and 8a) which acts against a follower 39 fixed to the lift pin 34 for movement therewith. The follower 39 is so shaped that it is not contacted by cam 38 until the tone arm is fully raised. Upon contact, the cam 38 then drives the follower 39 back, causing the tone arm to rotate outwardly away from the central post 3 to a position clear of a descending record of the largest diameter. At such time the cam engages a curved portion of constant diameter in the follower 39, so that the tone arm will remain stationary, the follower being so shaped that said tone arm will not commence to move inwardly until the record being lowered by the dog 2! has reached a position lower than the tone arm needle. The portion of the follower 39 which is engaged by the cam 38 to move the tone arm inwardly constitutes a return spring 49 (Figs. 2, 8, and 811). When said cam engages the spring, thefollower 39 will be rotated in a clockwise direction, as viewed in Fig. 8, moving the tone arm toward the central post 3. In order to dispose the same in the starting groove of the record just lowered, the follower 39 rotates in such direction until a shoulder 39A thereon abuts against a stop, hereinafter more fully described with reference to the discriminator or detector mechanism. This stop halts inward movement of the tone arm when the same is above the starting groove of the next record to be played. However, the cam 33 continues to rotate, and it is for this reason that the follower portion 49 is made resilient. The cam deflects the follower spring portion 49 until said portion disengages from the cam.

It may be mentioned that this engagement between the spring 49 and the cam 38 should 'be complete before lowering of the lift pin 34 moves the projection 39A away from the stop which has halted its movement. This permits the needle to be lowered to a predetermined position in the starting groove of a record of any fixed diameter. In the idling position of the cycling mechanism, as shown in Fig. 2, the lift pin is fully depressed and the tone arm released from all control, the latter rotating freely on the lift pin which rests on the lift cam 33. Any rotation of the tone arm about a horizontal axis during its playing position will be about the top of said pin, since in playing position, the roller 38 is clear of the shelf 35.

The mechanism for determining the end of a record When the cycle disc 20 has completed one revolution and the rubber tire 2| re-entered the notch 20A, the needle will be disposed in the starting groove and the turntable will continue to rotate, causing the last lowered record to play. The needle will follow the recorded groove until the end of play whereupon it will enter the leadoff groove. A play end sensing mechanism must then cause the cycling mechanism to start its operation. The play end sensing mechanism includes a long, rigid strip 42 (Figs. 1, 2, 3, 8 and 8a) which is mounted at one end for pivotal rotation about the lift pin 34. A horizontal plate 39B movable with the follower 39 underlies the pivotally supported end of the strip 42, and said strip extends far beyond the edge of said plate. A collar 34A is secured to the lift pin 34 a short distance above the plate 39B. With this construction, the weight of the strip 42 is carried by the extended edge of the plate 393 about which said pin fulcrums, the pivotally mounted end of the strip engaging the under side of the collar 34A, as best seen in Fig. 3. Such construction wil1 cause a frictional engagement between the strip 42 and the system which moves with the follower 39, said system including the collar 34A and the plate 393.

Due to the foregoing frictional engagement, the strip 42 will rotate about the lift pin 34 together with the follower 39 unless the frictional engagement between said strip and the system moving with the follower 39 is overcome. In such case, of course, the strip will rotate with respect to the fol'ower 39 in the direction of the applied force. The normal position of the strip 42 with respect to the system of the follower 39 is shown in Figs. 8 and 8a. In such position, said strip rests against a stop 44 carried by the plate 393. The strip is caused to assume such a position during an outward sweep of the tone arm by a pin 43. Thus, the strip is reset every time that the tone arm moves outwardly subsequent to the playing of one record and prior to the playing of the following record. In this reset or normal position, the strip 42 occupies a predetermined angular position relative to the tone arm which is such that as the tone arm moves inwardly during the playingof a record, the tip of the strip 42 will contact the lower end of the lever I! before the needle reaches the lead-off groove. The upper end of the lever l! is heavier than the lower end thereof'sothat normally the lever rests against a stop on the cycle disc '20. This normal position of the lever I1 is shown in Fig. 3a.

---In the samefigure, the tip of the strip 42 is disclosed in a position preceding contact between the strip 42 and lever l1. Eventually, however, during the play of the'record, the tip of the strip 42"wi11 engage the lower end of the lever I! and cause'the same torotate about the pin I8 in a counter-clockwise direction, as viewed 'in Figs. 311-301." Thisraises the upper end of the lever 41 into the path of travel of the pin l9 which, as will be remembered, rotates with the turntable.

" In'addition to the vertical side surface of the pin l9 heretofore described, said pin has a sloping lower surface. The distance the tone arm moves forward during one revolution of said record in a play of the same will move the strip 42 forward gen-ate only a short distance insufiicient to cause the upper end of the lever to contact the verticalside face of the pin [9. However, such movement er the tone arm will cause the upper end of the lever to be raised a distance such that the tip' of said upper end will be engaged by the sloping under surface of the pin. Such engagement between the pin and lever I! will rotate the lever I! in a clockwise direction, thus resetting the lever t! to the position shown in Fig. 30. Such cockw'i'se rotation of said lever will be transmitted to the strip 42, causing the same to rotate relative to the fiat plate 393 in a direction away from the stop 44. The position of the strip 42- before it is pushed back is indicated in Fig. 3b, and the posi: tion of said strip after it hasb'een pushed back is shown in Fig. 30. In Fig. 3c, the notation C an indicates the position of the strip 42 after beingpushed back, while the notation B indicates the corresponding position of said strip before it has been pushed back. It will be observed that the" backward motion of the strip 42 is againstthe frictional engagement betweeh said strip" and the plate 393. If this friction force is too high, theresetting motion of the lever 32B will be trans mitted' to the tone arm and will urigroove the needle, causing it to repeat grooves. According y, said frictional engagement between the strip 4 2 and the plate 39B should be made less than the force required to un roove the needle but large enough to cause rotation of the lever IT'into the path of the pin l9.

Such design may be accomplished by selecting the proper weight of strip 42. Also, this d'esigr'i can be brought about by making the lever If! relatively light and the pivot 18 with at" little friction as possibe. It will now be" appreciated that as the pin l9 makes one rotation, so does" the record, and' hence,- the needle wi l advance one'groove pitch distance at 'each rev0lution, caus ing the lever ll to rotate and raise the upper end thereof a distance proportionate to the ad vance of the playing needle. The height of thesloping portion of the pin I 9 is made greaterthan this rise of the upper portionof the lever I'1, thereby enabling said sloping portion to reset the lever ll once each revolution as lon as the needle is in the spiral' playing groove; that is; immediately before the pin l9 reaches the, lever ll, the relative position of the parts will be that shown in Fig. 3b, and as: the pin I 9 leaves the lever ll, the relative position of the parts-will'be that shown in Fig. 30. However, eventually, the needle will reach the lead-off groove. As is well known, the advance per revolution,- or pitch,- of a lead-off" groove is many times that of a recording groove. Therefore, as the needle traverses the'lead-off groove, it raises the upper end of thelever I? a distance greater proportionately than said pin is raised during the ordinary ad-, Vance of the tone arm a singlepitch distance at such time as the record is playing. The distancethe upper end ofthe lever is raised is greater than'the height of the inclined portion of the pin l9; This causessaid upper'endlto' contaet the vertical side surface of the pin I9 as shown in'Fig. 3d. Then, instead of the pin resettingth e lever I! by pushing the upper end thereof awn; the pin will force the lever l1 against the stop HA and start the cycle disc rotating.

As already explained, the pin will maintain? contact with the upperend of. the lever 11, until the disc is turned far enough for the rubbe'rltire 2| to engage the side surface of the disc. therubber tirecontiriues' to turn the disc' for one I sive record ma prevent s d; sa ,4

ger wh ich liesflin t path of travel of the strip iii retention un'rii said tire (mesa-gain re-ehtrs the notch portio n 29A; Rotation of the disc dur ing one revolution completes a record change cycle, depositing a new record on the turntable,

moving the tone arm out of the way of the deend of the lever ll rises whenthe tone arm moves the pitch distance of a playing groove. How" ever; it will be understood that if said height is simply greater than the distance moved by the upper end of the lever I? for advance of the needle one pitch distance, the invention will be carried out. e I e H v Y It will now also be a parent that pursuant to this feature of the invention; the mechanism for a sensing the end of a record play measures the advance of the tone a1 once for each IVQlllti'on of the turntable,- and immediately upon measuring if the end of the record hasnot been reached, res'ets. It should also be noted that the l stoppin 4'4 and resetting pin 43 conjointly act to limit the outward moven'ieht of the tone armat such time as the same is moved; away from the central post 3 becausepf engagementqf the cam 38' and follower 3'9: Thi si's necessary because: no

meanslijs' provided ea- 1 1 said feup er against the cam as the tone armmoves outward, t is thus possiblethat the tonearm may be moving 4 sition. However, this is d? by abutment of the strip 42 against the resetting pin 43 and abutment of the said Strip e at rs- It wil appreciated that the; foregoing means for sensing the endof eeojrd' play function only when the" toneLairin d "g one revolution moves" further than the 7 a1 pitch distance. How; ever, some" reoords have a very small Iea'd fi groove and it is; desirable, therefore to provide in addition to: the abovedes'cribed pitch responend-sensing mechanism to include a re se sing the" m re record play, which-latter means is responsiveto thepo sition of the toneafrh'and which will; act in the event that the tonefarm moves'very close to the eentrar post 3* without ever-advancing more than the normal pitch distahcduring any given revolution. such position sensing means includes a spring 45" (Figs. 1;; 8f and 8a)" which is secured to an e'dgeflof the flat plate: 393 remote from the spring has an upstanding firi- 42" as the 's'anie'turnsaboutthe' lift Dinfi.

It will as understood"; that during orolih'a ry 0p e r'ation of the strip 42 as the mechanism for measuring" the advanceof the tone arm once during each revol'ution or the turntable, said strip is caused" to' rotate in short angular steps in a counter-cloekwise direction; asviewed in Fig. 3', about the 11ft pin 34 untiis'uehtime as a marked advance of the tone arm will oaus'elthe lever I? tobe moved suffici'ehtly' to engage the; pin [9. Howev r, when the strip 42 is moved farenough toencounter the spring 45, said strip, instead of beingpushedback bythe resetting action of the IBonthe lever lll', will riesumeits position as soon as the pin IBJpasses the upper end of said lever, the spring d e serving to bias the strip 52 back. This causes successive advances of the tone arm during consecutive revolutions or the turntable to be added, and therefore, in two or a few 11' revolutions, the lever will be tilted sufiiciently for its upper end to engage the pin |9. In this manner, records without lead-off grooves, or of very small central diameter, are tripped off at the end of a playing cycle.

It is also desired to point out that the determination of the advance of the tone arm during one revolution of the turntable is measured over a small fraction of a revolution. This is highly desirable since it nullifies the effect of an eccentric mounting of the record. Such eccentric mounting at the present time has caused considerable difficulty in most trip mechanisms, as, for example, in velocity trip mechanisms, position trip mechanisms, and those trip mechanisms which measure motion of the tone arm during a revolution. However, the present pitch measuring trip mechanism determines the advance of the tone arm and resets itself almost instantaneously at one definite position for each revolution of the turntable, and, therefore, is not sensitive to the wobble of the tone arm due to the eccentricity of the record spiral center with respect to the turntable center, which wobble occurs in phase with the rotation of the turntable.

The discriminating mechanism The discriminating or detecting mechanism is that which ascertains the size of a record and automatically in response thereto, positions the tone arm in the starting groove in a record of the measured size. Attention is recalled to the manner in which the tone arm is moved back toward the central post 3. This motion is caused by engagement of the cam 38 with the spring portion 48 of the follower 39. Such motion causes the tone arm to rotate in a clockwise direction, as viewed in Fig. 8, and causes the plate 393 to rotate with the tone arm inasmuch as the sam is fixed to the lift pin 34. However, this plate carries the projection 39A. When a record of minimum diameter, for example, a -inch record, is lowered from the stack to the turntable, said record does not engage any element of the discriminating mechanism. During theinward movement of the tone arm at the time such a record is to be played, the clockwise motion of the flat plate 39B is checked by abutment of the projection 39A against a dog 4|, pivoted to the bracket 3|, as clearly shown in Fig. 2. The relative position of the projection and dog at such time is illustrated in Figs. 8a and by position 2 in Fig. 7. When a record of larger diameter is lowered to the turntable, an element of the discriminating mechanism is engaged and moved by the record. This causes another dog to be disposed in the path of travel of the projection 39A during inward movement of the tone arm. Said dog is disposed in advance of the dog 4|. Thus, inward movement of the tone arm will be halted at an earlier stage, and in such manner, a larger record, for example, a 12-inch record will cause the tone arm to be initially positioned further away from the central post 3.

More specifically, said discriminating mechanism includes a lever 46 v(Figs. 1, 4, 5, 6 and '7) which is pivoted on a pin 4'! (Fig. 2) rotatably mounted in fixed bearings in a bracket secured to the support S. The lever 46 is unbalanced by a weight W fixed to an end thereof remote from the end facing the stack of records. This weight is of such magnitude and so located as to cause the lever to normally seek an approximately horizontal position. When in such attitude, the

forward end of the lever, i. e., that remote from the weight, will project into the path of a lowering record of larger diameter, e. g., 12-inch, but not into the path of a lowering record of smaller diameter, e. g., 10-inch. Said lever has a cam element 46A provided on its upper surface. This cam element lies beneath the inturned upper end of a follower rod 48 so that said rod is supported on the cam element. At the beginning of each cycle, the lever 46 and its follower 48 are disposed in the normal position, illustrated in Fig. '7. If a large disc descends, it will strike the forward end of the lever 46, rotating the same to the position illustrated in Fig. 4. In this position, the cam element 46A presents a flat upper surface close to the pivot pin 41, whereas, as will be seen from inspection of Fig. 7, in the normal position of the lever 46, the follower is supported by a part of the cam element relatively remote from the pivot pin 41. Thus, when the lever is rota.ed by the passage of a large disc, the follower 48 is lowered. Due to the fact that the upper surface of the cam element in said position is flat, the follower will hold the lever 46 in this new position.

The lower end of the follower 48 is positioned adjacent the dog 4| on the side of the dog nearest the projection 39A, as will be seen in Figs. 8 and 8a. When the follower 48 is lowered upon passage of a large disc, the lower end thereof will be interposed in the path of travel of the projection 39A and thereby cause the tone arm to stop its inward movement at the lead-in groove of the large record.

The operation of the discriminating mechanism is as follows: Assuming said mechanism to be in normal position, as illustrate-d in Fig. '7, when a large disc drops, it will move the lever 46 and follower 48 to the position illustrated in Fig. 4. At such time, the plate 393 is in elevated position on the plane illustrated by position I in said figure. Said projection is also angularly spaced from the dog 4| and lower end of the follower 48. The follower 39 is then moved in a direction to shift the tone arm inwardly by engagement therewith of the cam 38. The projection 39A on the plate 39B will strike the lower end of the follower 48. Now, the tone arm will be vertically lowered and, at the same time, the follower 39 depressed. This causes the same to be moved to position 2 in said figure so that the tone arm is free to swing inwardly while following the playing spiral of a record.

At the end of the play, the follower 39 will reach position 2 in Fig. 5 at which time it is beneath the lower end of the follower 48 and beneath the pivoted dog 4|. Now, the cycle disc has been placed in operation and, as will be remembered, the initial step is to raise the follower 39 so as to elevate the tone arm. Raising the follower 39 elevates the dog 4| and follower 48 but when the follower 48 is raised, the weight W will restore the lever 46 to its horizontal position. The movement of the follower 39 from depressed to raised position is illustrated by positions and 2 of Fig. 6, the disposition of the parts in position 2 being illustrated in full lines in said figure. This resets the discriminating mechanism. Now, if a record of smaller diameter is lowered, the raised follower 39 will encounter not the follower 48 but the dog 4| during its movement from position I to position 2, as illustrated in Fig. 7.

Next, the follower 39 lowers, as shown in posi-i tion of said figure, whereupon the tone arm is free to swing inwardly. In the event that the reject button It is pressed while the tone arm is in raised position, in which case the flat plate 393 is not beneath the follower 48, said follower would not be reset. To provide for such contingency, a lever 49 is included. This lever is pivotally mounted beneath the support S and is caused to rotate when the reject button is pressed. Said lever is connected to the follower 48 and rotation thereof upon pressing the reject button will lift 48, allowing 46 to be reset.

It will thus be seen that there is provided an automatic phonograph in which the several objects of this invention are achieved, and which are well adaptedto meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention. I claim as new and desire to secure by Letters Patent:

1. In combination, in an automatic phonograph including a turntable and a stationar central post about which said turntable is adapted to rotate: means to support a stack of records on the central post offset from the axis of rotation ,of the turntable, said mean including an element for supporting the lowermost record of the stack adjacent its central opening, means to level the records in said stack, said level ing means including at least two elements diametrically disposed on opposite sides of the central post and adapted to press down against the top surface of the uppermost record in the stack, said elements being mounted for vertical movement, and means to maintain said elements in a common plane as they move vertically, means to rotatably mount said stack record levelling means about an axis parallel to the central post at a point remote from the central post whereby said levelling means may be swung clear of the stack of records when records are loaded on or removed from the central post, and means rotatable about said axi with said record stack levelling means and moved into operative position when said levelling means is rotated out of operative position to support the under surface of the lowermost record of the stack adjacent the periphery thereof.

2. In combination, in an automatic phonograph including a turntable and a stationary central post about which said turntable is adapted to rotate: means to support a stack of records on the central post offset from the axis of rotation of the turntable, said means including an element for supporting the lowermost record of a stack adjacent its central opening, means to level the records in said stack, said leveling means including at least two elements mounted for vertical movement and coordinated for joint movementin a common plane as they move vertically, means to mount said 'stack-record-leveling means for rotation about an axis parallel to the post to one side of the stack whereby said leveling means may be swung clear of the stack of records when records are loaded on or removed from the central post, and means rotatable with said recordstack-leveling means and moved into operative position, when said leveling means is rotated out of operative position, to support the under sur- 14 face of the lowermost record of the stack adj acent the periphery thereof.

I 3. In combination, in an automatic phonograph including a turntable, a tone arm, a notched cycle disc and a rotary frictional member turned by said turntable and normally freely turning in the notch of said disc: a record end play sensing means comprising an element frictionally coupled to said tone arm so as to move therewith and to be capable of movement relative thereto, a second element pivoted on said cycle disc to turn about a horizontal axis, said second element including an end having a substantially horizontal side and a substantially vertical side, the other end of said disk being positioned for engagement by said first element in such manner that advance of said tone arm will cause the first-mentioned end of said second element to move toward said turn-.

table, a member carried by said turntable and having a sloping under surface at an acute angle to the plane of rotation of the turntable and a vertical side above said under surface, said member being disposed so that during rotation of the turntable said member will intersect the position of the mentioned end of the second element, said sloping surface being high enough to engage the horizontal side of the first-mentioned end of thesecond element to push down said end when the same is raised at two successive revolutions of the turntable a distance not substantially greater than that corresponding to an advance of the tone arm a pitch of the playing spiral of a record, the vertical side of said member engaging the vertical side of the first-mentioned end of the second element when said end is raised up a distance corresponding to an advance of the tone arm substantially more than the pitch of the playing spiral of a record, means to limit rotation of said second element relative to the disc when said second element is engaged by said member so that said member will initiate rotation of the cycle disc when the same engages the second element and move said disc substantially to permit 7 frictional engagement between the circular frictional member and the cycle disc whereby said cycle disc, when the second element is engaged by the member carried by the turntable, will turn through one revolution until the circular frictional member again reaches the notch in the cycle disc.

4. In combination, in an automatic phonograph including a turntable, a tone arm, means to support a stack of records of difierent fixed diameters and means to successively transfer records from said stack to said turntable: means to swing the tone arm out away from the center of a played record and to then swing said arm back above the starting groove of the next record, said means including an element movable therewith, said element having a projection, means to shift said element in a direction transverse to that in which it moves upon motion of the tone arm toward and away from the center of a record, a stop disposed in the path of travel of said projection in one extreme position thereof as the tone arm moves toward the center of the record whereby to render said tone arm moving means ineffective to advance the tone arm further toward the center of a record, a second stop between said first stop and said projection when the tone arm is swung out, and means disposed in the path of travel of a large record moving from the stack to the turntable, said means being operable upon engagement by a large record to move the second stop in a direction parallel'to the direction in which said element shifts into the path of travel of the projection whereby, when a large record is to be played, the tone arm moving means will be rendered ineffective earlier in its advance toward including a turntable, a tone arm, means to support a stack of records of different fixed diameters and means to successively transfer records from said stack to said turntable: means to swing the tone arm out away from the center of a played record and to then swing said arm back above the starting groove of the next record, said means including an element movable therewith, said element having a projection, means to shift said element in a direction transverse to that in which it moves upon motion of the tone arm toward and away from the center of a record, a stop disposed in the path of travel of said projection in one extreme position thereof as the tone arm moves toward the center of the record whereby to render said tone arm moving means ineffective to advance the tone arm further toward the center of a record, a second stop between said first stop and said projection when the tone arm is swung out, and means disposed in the path of travel of a large record moving from the stack to the turntable, said means being operable upon engagement by a large record to move the second stop in a direction parallel to the direction in which said element shifts into the path of travel of the projection whereby, when a large record is to be played, the tone arm moving means will be rendered ineffective earlier in its advance toward the center of the record, said element shifting after play of a record to its other extreme position in which as the tone arm is moved away from the center of a record, the projection will clear both stops, said tone arm moving means including a lost motion mechanism whereby said means can be rendered ineffective even when continuously actuated.

6. In combination, in an automatic phonograph including a turntable and a stationary central post about which said turntable is adapted to rotate: means to support a stack of records on the central post offset from the axis of rotation of the turntable, said means including an element for supporting the lowermost record of the stack adjacent its central opening, means to press down on the uppermost record in said stack at a plurality of points in a common plane so as to level the stack, means to mount said levelling means for movement about an axis parallel to the post between two positions, in one of which said levelling means is disposed for effective operation and the other of which said levelling means is clear of the stack, and means about said axis to support the under surface of the lowermost record of the stack at a point remote from the center thereof, said last named means being rendered effective when said levelling means is clear of the stack.

7. In combination in an automatic phonograph including a turntable, a tone arm, a

. 16 notched driven cycle disc and a rotary driving member turned by said turntable, adapted to drive said disc and normally freely turning in the notch of said disc: a record end play sen s-' ing means comprising an element frictionally coupled to said tone arm so as to move therewith and to be capable of movement relative thereto, asec'ond element pivoted on said cycle disc and engageable by said first element in such manner that advance of said tone arm will rotate the second element and cause one end of said second element to move toward said turntable, a member carried by said turntable, said member having two surfaces, one said surface being disposed to tance not substantially greater than that corresponding to an advance of the tone arm a pitch of the playing spiral of a record, said second element being rotated at such time in a direction opposite to that in which it is rotated by the first element, the other said surface of said memher being disposed to engage the mentioned end of the second element when saidend is raised up a distance corresponding to an advance of the tone arm substantially more than the pitch of the playing spiral of a record at two successive revolutions of the turntable, said second surface causing the second element to rotate in the same direction as that in which it is rotated by the first element, and means to limit rotation of said second element relative to the disc in the direction '3 in which it is rotated by the first element, so that when said second element is engaged by the second surface of said member, said member and second element will initiate rotation of the cycle disc and move the disc substantially to permit engagement between the rotary driving member and the disc.

FRANK M. J OHNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date I 1,271,590 Lefever July 9, 1918 1,474,776 Hunt Nov. 20, 1923 1,879,291 Johnson et al Sept. 27, 1932 2,090,746 Compare Aug. 24, 1937 2,211,423 Hokanson Aug. 13, 1940 2,237,340 Downs Apr. 8, 1941 2,270,995 Compare Jan. 27, 1942 2,286,490 Knox June 16, 1942 2,287,727 Cranmer June 23, 1942 2,293,723 Erickson Aug. 25, 1942 2,311,596 Pressley Feb. 16, 1943 2,328,052 Butler Aug. 31, 1943 2,330,293 Knox Sept. 28, 1943 2,333,414 De Tar Nov. 2, 1943 2,371,362 Small Mar. 13, 1945 2,390,862 Alexandersson et al. Dec. 11, 1945 2,402,150 Dale June 18, 1946 FOREIGN PATENTS Number Country Date 99,762 Sweden Sept. 3, 1940

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