US2371362A

US2371362A - Record changing mechanism for phonographs

Info

Publication number: US2371362A
Application number: US331327A
Authority: US
Inventors: Anna M Small
Original assignee: Farnsworth Television and Radio Corp
Current assignee: Farnsworth Television and Radio Corp
Priority date: 1940-04-24
Filing date: 1940-04-24
Publication date: 1945-03-13
Anticipated expiration: 1962-03-13

Description

March 13, 1945. T. w. SMALL RECORD CHANGING MECHANISM FOR PHONOGRAPHS Fild April 24, 1940 FIG. ,1

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March 13, 1945. T. w. SMALL 2,371,362

RECORD CHANGING MECHANISM FOR PHONOGRAPHS Filed April 24, 1940 5 Sheets-Sheet 2 PIT 3 I INVENTOR.

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RECORD CHANGING MECHANISM FOR PHONOGRAPHS Filed April 24, 1940 a SheetsSheet s in l/llllllllllllfllllll.

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Patented Mar. 13, 1945 RECORD CHANGING MECHANISM FOR PHONOGRAPHS Thomas W. Small, Fort Wayne, Ind.; Anna M. Small, executrix of said Thomas W. Small, de-

ceased, assignor,

by mesne assignments, to

Farnsworth Television 8; Radio Corporation,

Fort Wayne, Ind.,

a corporation oi Delaware Application April 24, 1940, Serial No. 331,327

8 Claims.

This invention relates to an automatic record changer for disc record phonographs wherein the stack of records is supported above the tumtable, the lowermost record of the stack being released to drop by gravity upon the turntable for reproduction.

The principal object of the invention is to enable a selective record changing mechanism to be produced with a minimum of working parts so as to be capable of economical production and take up little space in the phonograph. Thus, the invention is primarily directed toward improving upon record changes of this type in the direction of simplified mechanism.

One feature of the invention resides in the simplified adjustable record support for groups oi either 10- or 12-inch records in the nature of a pair of nested plates, the shorter plate being fixed and the longer plate being pivoted relative thereto so as to be swung about its pivotal mounting to expose the shorter fixed plate. The phonograph is provided with oppositely disposed pairs of supporting plates mounted above the tumtable upon which a stack of records may engage and be supported along the diametrically opposite portion of their edge. This arrangement is such that a stack of 10-inch records may be sup ported above and in spaced relation to the turntable by the longer pivotal plates while a stack of 12-inch records may be similarly supported by the fixed plates when the longer plates are swung upwardly and free thereof.

Another feature of the invention resides in the mechanism for releasing the lowermost record of the stack of superimposed records while said plates continue to support the records of the stack thereabove. This is accomplished :by an upwardly extending portion of the centering pin which is fixed to and rotatable with the turntable in association with a slight forward motion of one pair of the nested supporting plates. end, the centering pin extension is provided with a reduced portion or neck lying in the plane of the lowermost record when supported on said plates and terminating in an enlarged head of substantially the diameter of the central hole of the record lying in the plane of. the next record above the lowermost record. Said head may be continued into a further upward extension tapering to a reduced portion to permit convenient threading of the records thereon. By a forward pushing movement of one of the plates against the edge of the lowermost record, it may be To this I reduced neck of the spindle while the next record thereabove is maintained in its normal position by the enlarged head portion. Upon return movement of such supporting plate, the lowermost displaced record will drop down onto the turntable into playing position.

Another feature of the invention resides in the driving mechanism for transmitting movement from the turntable drive to the record shifting means to automatically effect a change of records. This is accomplished by a cam wheel having a mutilated periphery normally in registry with the turntable drive, but movable upon completion of the record out of registry whereby the turntable drive will engage and rotate the cam wheel to effect the record shifting operation.

Other objects and features of the invention will be readily understood from the accompanying drawings and the following description and claims:

Fig. 1 is a plan view of the record changer with the unplayed records removed. Fig. 2 is a side elevation thereof showing a group of 10-inch records supported over the turntable and on the turntable in playing position, but with the trip mechanism removed for clearness. Fig. 3 is the sameas Fig. 2 showing a rear elevation of the record changer. Fig. 4 is the same as Fig. 2 showing a bottom plan view thereof. Fig. 5 is schematic top plan 'view'of the trip mechanism as positioned during the playing of a record. Fig. 6 is a section taken on the line 6-6 of Fig. 5. Fig. '7 is an illustrative showing of the lowermost record being displaced laterally to effect its release in full lines, and showing its position after I complete release in dotted lines. Fig. 8 is a wiring diagram showing the circuit through the switches and motor.

In the drawings thereis shown a record changingand reproducing mechanism including a base It supporting a horizontally rotatable turntable H carrying one or more records I 2 thereon, the uppermost record of the group carried by the turntable being positioned for reproduction.

- The unplayed records l2 are supported in a stack shoved laterally to the extent permitted by the immediately above the turntable and spaced therefrom in position for release of the lowermost record for permitting it to drop by gravity into playing position on the turntable. Associated with the turntable there is the usual reproducer l3 mounted on the end of the tone arm It.

The unplayed stack of records l2 have the dimetrically opposed'peripberal portions or their edges supported by pivotally mounted longer supporting plates i5 and I6, which plates are ex-- tended to support the stack of -inch records as illustrated. Nested within said plates I5 and II and embraced thereby there are shorter plates ISA, I 6A which are fixed on their supports and are so related as to support 12-inch records. For this purpose, and in order that the shorter plates may be exposed, the plates I5 and it are pivotally mounted at I! so that they may be swung upwardly to a vertical position out of the way of the 12-inch records when supported on the plates ISA, IA. The plates I8, ISA are supported upon a movable standard I 8 as will be hereinafter described, whereas the plates I8, ISA are supported upon a fixed standard I9 secured to the base plate I. by a bracket 20.

The turntable II is provided with the usual record centering pin indicated at 2I extending upwardly therefrom and of the usual diameter for a distance of substantially the maximum height of the stack of records when all have been dropped into playing position on the turntable. From that position upwardly there is an extended portion in the form. of a taper indicated at 22 which terminates in the reduced neck portion 23. As shown in Fig. 2, said neck portion lies in the plane of the lowermost record and extends throughout substantially the thickness thereof. Said neck portion 23 terminates in a head 24 lying in the plane of the next record above the lowermost record and is of a diameter slightly less than the centering hole thereof so as to truly center said record in respect to the supporting plates.

The head 24 terminates in a tapered shoulder indicated at 25 which ends in a reduced record threading extension 2. Thus the records may be conveniently mounted over the threading extension 2 and by the tapered neck portion 25 may be guided into centered position as they are lowered into the plane of the head 24.

' The displacement of the lowermost record from the supports into playing position on the turntable is eflected by a forward pushing move ment imparted to the plates I5, ISA by tilting of the standard II. Said plates are provided with shoulders 21 and- 28, the shoulder 21 abutting against the adjacent edge portion of a 10-inch record and the shoulder 28 against a corresponding edge of a 12-inch record. When the standard II is tilted in the manner hereinafter described, said plates will be moved forwardly to engage and push the lowermost record so that it will be displaced laterally and in respect to the neck portion 23 from its position as shown in Fig. 2 to the position shown in full lines in Fig. '1. The other edge of said record will freely slide upon the plate I6 or ISA. During this movement the head 2| will maintain the next record thereabove in its centered position as well as the superimposed records in the stack. Thus the lowermost record will'be displaced laterally with respect to the superimposed records.

After having thus displaced the lowermost record. the plates IE, ISA will be returned from their actuatedto their normal position as shown in-Figs. 1 and 2. This return movement of said plates will release the adjacent edge of the record, permitting it to drop downwardly until the central opening engages with the extended portion 22 of the centering pin, such movement eifected by its weight being suflicient to slide it from the plate ll, IIA. Thereupon, the superimposed records will drop down so that the record'which had been centered by the head 24 will be supported at its edge upon the supporting plates, while the released record will drop onto the turntable and be centered thereon in playing position by the centering pin 2|.

The driving mechanism. for both the tumtable and the record changing device comprises the usual electric motor 29 which is controlled by a switch 30. The motor continuously operates to continuously rotate the turntable through a turntable driving shaft ii to which is keyed a pinion 32 positioned to mesh with the teeth surrounding an actuating cam wheel 33 rotatably suspended from the underside of the base plate It by a stud 34, which stud is surrounded by a spacer 35. While the pinion 32 and cam wheel 23 are shown herein as provided with the usual intermeshing teeth, they may, if desired, be provided with friction surfaces whereby the pinion will frictionally engage and drive the cam wheel. The cam wheel is provided with a mutilated section indicated at 38 so that when said wheel is rotated to such position that said section lies adjacent the pinion 32, there will be no driving engagement between the pinion and wheel. In this position of the wheel, the record changing mechanism is at rest while a record is being reproduced. Upon completion of the record, the trip mechanism, to be hereinafter described, imparts a slight rotary movement to the wheel so as to move its teeth or friction driving surface into driving contact with the pinion 32 whereupon the cam wheel will be caused to rotate by the pinion through one revolution, bringing the mutilated portion 36 back into registry so that the wheel is no longer driven and again comes to rest. During this cycle of movement of the wheel the lowermost record from the stack is caused to drop into playing position and the 0 tone arm manipulated for that purpose.

As the wheel starts to rotate in the direction indicated by the arrows, a depending cam surface 31 engages a cam follower 38 mounted on a lever 39 which is fulcrumed intermediate its ends at I, said fulcrum comprising a pivotal mounting on the lower end of a bracket (I depending from the base plate. The free end of the lever engages the lower end of a vertical pin 42 slidably mounted in a guide 43 and extending upwardly through the base plate in position to engage the underside of the tone arm I4. Thus the first operation actuates the lever 39 to elevate the tone arm and lift the reproducer from the record being played.

Thereupon the reprcducer is swung outwardly, clear of the records on the turntable. This is accomplished by a cam 44 on the cam wheel which is brought into engagement with a head 45 of a lever 46. Said lever is fulcrumed intermediate its ends at H on the lower end of a post 48 depending from the base plate. The free end of lever 46 engages a bar 49 which is secured to a post 50 extending vertically through suitable hearings in the base plate and upon which the tone arm is secured as to horizontal movement but pivoted at SI for vertical movement. Thus as the head 49 is moved outwardly by the cam It, the lever 46 will bear against the plate 49 and turn it for swinging the tone arm free of the turntable and supported records.

The tone arm is brought back to the beginning of the next record to be played at the end of the cycle by a spring 52. One end of said spring is connected with a bracket 53 secured to the base plate while the other end is connected with an arm 54 freely pivoted to the underside of the base plate upon a stud 55. The arm 54 extends into free engagement with an end of the tone arm swinging plate 19 on the opposite side of its pivotal mounting from that engaged by the tone arm swinging lever 48.

After the cam wheel is moved to release lever 46, the tone arm is free to swing inwardly to the beginning of a new record under tension of the spring 52. The tone arm is positioned by the arm 54 being arrested by an oblong head 58 extending in the path of said arm from a depending stud 51 rotatable in the base plate Ill. The stud and head has a knurled knob 58 with a pointer 50 to indicate its adjusted position for arresting the tone arm for either a 10- or a 12- inch record. If the head 55 is turned by the knob 58 so that the arm engages its longer side, the tone arm will be permitted to swing inwardly to the farther position for a -inch record. If the head is turned to have its and engaged by the arm, it will arrest the inward movement of the tone arm in the position for the beginning of a 12-inch record.

The next operation after swinging the tone arm clear of the turntable is to operate the plates [5, ISA by swinging them inwardly to shove the lowermost record to releasing position. For this purpose, the standard l8 extends downwardly through the base plate II and into a depending bracket 50. The bottom of said standard, which is below the plane of the wheel 33, is bent at right angles to form a horizontal arm portion 6| extending under the cam wheel. or elbow portion it is pivoted to the bracket 60 at 62. The arm portion 5| or said standard is At its bent in position to be engaged by a pin 53 extending downwardly from the under side of the cam wheel so that as the wheel rotates said pin will kick the arm 6| downwardly to move the plates l5, ISA forwardly. Immediately after the pin 63 passes from under the arm it is returned to normal position to retract said plates by a spring 64. Spring '54 has one end secured to the underside of the base plate and the other is connected with a rod 65 extending sideways from the arm so as to avoid interference with the cam wheel.

Following this action and allowing sufficient time for the record to be released to drop onto the turntable, the tone arm is then swung into the beginning of the newly deposited record in the manner above described. Thereupon the cam wheel has completed its cycle and comes to rest with the mutilated portion registering with the pinion 32.- r

The trip mechanism for initiating the record changing cycle is best shown in Fig. 5. This mechanism comprises a follower arm 66 which has one end frictionally engaging the tone arm swinging post 50. Its free end extends toward the cam wheel and is connected with a trip arm 61 through a connecting rod 63. The trip arm 51 is pivoted at 63 to the under side of the base plate l0 over the cam wheel. One end of the trip lever is provided with a flexible pawl ll! formed of sheet metal which bears under spring tension against an upper surface about the rim of the cam wheel. Extending upwardly from said rim portion of the cam wheel normally under the pawl 10 there is .a short stud H adjacent the end of said pawl. The other end of the trip lever 61 is provided with an inwardly extending curved head I2 projecting toward the pinion 32 which rotates with the motor. Extending out wardly from the hub of said pinion in the plane of the head I2 there is a striker 13.

The trip mechanism functions in the following manner. During the playing of a record the tone arm moves inwardly with thegrooves, frictionally swinging the arm 65 and consequently the head 12 oftrip lever 6! toward the hub of pinion 32. For each rotation of the striker I3 with the pinion and turntable, the head 12 will be moved inwardly a slight distancecorresponding to the pitch of the records. Thereupon the striker I3 will engage the head "and push it back a corresponding distance, causing the arm 85 to frictionally move about its connnection with the tone arm. During this operation effected by the playing 01' the record, the downwardly curved end of the pawl 10 is free to move back and forth over the pin H the distance of the reproducing record groove pitch. However, upon the terminating record grooves, whether of spiral or eccentric pitch, being reached by the reproducer, the rapid swinging thereof will throw the trip lever 81 inwardly a substantial distance before it is again struck by striker 13. This throw will be suflicient to carry the downwardly curved end of pawl In over the pin 1|, locating it on the other side thereof. Then, when the striker 13 again strikes the head I2, it will move it outwardly a substantial distance suflicient to cause the end of pawl 10 to push the pin 'II and cam wheel 33 a, corresponding distance. This action will move the mutilated portion 36 beyond the pinion, bringing the gear teeth or the frictional surface of the pinion and cam wheel into driving engagement. The cam wheel will thereby be'rotated to drive the record changing operation above described until the mutilated portion 36 again registers with the pinion and with the stud H again lying under the pawl III, arresting further action of the record changing drive.

Arrangement is also made for manually tripping the mechanism to initiate the record changing action and change the record. For this purpose there is provided a rod I4 pivoted to the underside of the base plate at I5 and having itsfree end bearing against the trip lever 61. Connected with said rod intermediate its ends there is a manually operated lunger 16. By pressing 'the plunger, the rod II will impart the same action to the trip lever 51 as is impartedthereto action as above described takes place.

. lies adjacent the cam wheel 33. It is normally closed but is opened by the head 18 when the cam wheel 33 reaches the position wherein the tone arm is swung free of the turntable. Thus, when it is desired to stop the machine and discontinue its operation. the snap switch 30 may be moved to off position so as to break the circuit therethrough. However, the circuit through the motor will continue to be closed by the normally closed hold-in switch I1 until the tone arm is swung to its outer position, whereupon head 18 will open said switch and break the circuit to the motor and thereby bring the machine to rest. To start the machine. the switch 30 is turned to on position which again closes the motor circuit, moving the cam wheel to a position to again close the switch 11 so that it will then be prepared to continue the circuit closed until the hand switch is again opened andthe tone arm has ben swung to its outermost position.

The invention claimed is:

1. An automatic record changingmecha'nism for a phonograph comprising a turn table, a motor for rotating said turn table, a tone arm cooperating with arecord on said turn table to be moved inwardly a normal distance by the pitch of the record grooves, a cam wheel provided with a mutilated section and operative to change a record on said turntable, coupling means respon-- record on said turn table, a driving member drivdriving member upon said lever being moved by said tone arm a greater than normal distance.

2. An automatic record changing mechanism for a phonograph comprising a turntable, a motor for rotating said turntable, a tone arm co-' operative with a record on said turntable, a cam wheel provided with a mutilated section and operative to change a record on said turntable, a'driving member driven by said motor, said member being freely rotatable with respect to said wheel when the mutilated portion thereof is in registry and positioned to drive said wheel upon the mutilated portion being moved out of said continually rotating shaft forehanging a sive to the movement of said pickup arm adapted to be engaged with said cam means upon arrival of said pickup arm at the tripping groove of a record on said turntable, and a member associated with said continually rotating shaft for engaging with said coupling means when said coupling means is engaged with said cam means for moving said cam means into engagement with said continually rotating shaft.

5. An automatic record-changing mechanism for a phonograph comprising a continually rotating turntable with a shaft, a pivotally mounted registry, a trip lever operatively connected with lated to said lever as to be unaffected by its movement when restricted by the normal pitch of the record grooves but be effectively engaged to move with the movement of said lever upon the movement of said lever being accelerated by a more rapid advance of the tone arm.

3. An automatic record changing mechanism for a phonograph comprising a turntable, a motor for rotating said turntable, a tone arm cooperative with a record on said turntable, a cam wheel provided with a mutilated section and operative to change a record on said turntable, a driving member driven by said motor,.said member being freely rotatable with respect to said wheel when the mutilated portion thereof is in registry therewith and positioned to drive said wheel upon the mutilated portion being moved out of registry therewith, a trip lever operatively connected with said tone arm to move inwardly therewith, and means actuated by the eifective movement of said trip lever for imparting a partial rotation to said wheel to thereby move itspickup arm for cooperating with a record on said turntable, a cam means adapted to be driven by said continually rotating shaft for changing a record on said turntable, coupling means responsive to the movement of said pickup arm adapted to be engaged with 'said cam means upon arrival of said pickup arm at the tripping groove of a record on said turntable, and a member associated with said continually rotating shaft for engaging with said coupling means when said coupling means is engaged with said cam means for moving said cam means into engagement with said continually rotating shaft.

6. An automatic record changing mechanism for a phonograph comprising a continually rotating turntable with a shaft, 2. pivotally mounted pickup arm for cooperating with a record on- 'to be moved into engagement with and be driven by said continually rotating shaft for changing a record on said turntable, lever means frictionally connected with said pickup arm, said lever means being positioned to operatively engage with said cam means upon arrival of said pickup arm at the tripping groove of a record on said turntable, and a member associated with said continually rotating shaft movable thereby to engage said lever means when said lever means has engaged said cam means to move said cam means into engagement with said continually rotating shaft.

'1. An automatic record changing mechanism for a phonograph comprising a continually rotinually rotating shaft, 9. pivotally mounted picktating turntable with a shaft, said shaft having associated therewith a projection, a pivotally mounted pickup arm for cooperating with a record on said turntable, a cam means rotatably mounted to be moved into engagement with and driven by said continually rotating shaft, for changing a record on said turntable, lever means frictionally associated with said pickup arm, whereby when said pickup arm moves a normal distance during one revolution of a record on said turntable, said projection on said rotatable shaft maintains said lever means out of engagement with said cam means and when said pickup arm moves an abnormal distance during one revolu tion of a record on said turntable, said lever means is moved to operatively engage with said cam means, and a member associated with said continually rotating shaft movable thereby to Y engage said lever means when said lever means has engaged said cam means to move said cam means into engagement with said continually rotating shaft.

8. An automatic record changing mechanism fora phonograph comprising a turntable, a motor for rotating said turntable, a tone arm ocoperative with a record on said turntable, a cam gear provided with a mutilated section and operative to change a record on said turntable, a pinion continuously. driven-by said turntable motor associated with saidcam gear to freely rotate with respect'thereto when the mutilated section thereof is in registry therewith and drive said cam gear upon said mutilated section being, moved out of registry and said gear brought into mesh therewith, a lever fulcrumed intermediate its ends in operative relation with respect to said pinion positioned for operative engagement with the opposite end of said lever arranged periodically to strike said lever and return it to normal position after inward movement therewith caused by normal travel 01' the tone arm over said record, the opposite end of said lever arm being adapted to engage the projection on said cam gear for partially rotating the same into mesh with said pinion upon said lever being struck by the projection on said. pinion caused by a more rapid advance of the tone arm inwardly of the record.

THOMAS W. SMALL.