US1792735A

US1792735A - Automatic phonograph stop

Info

Publication number: US1792735A
Application number: US247688A
Authority: US
Inventors: Henry E Fracker
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1928-01-18
Filing date: 1928-01-18
Publication date: 1931-02-17
Anticipated expiration: 1948-02-17

Description

Feb. 17, -19,31. H. E. FRAc-KER y 1,792,735

AUTOMATIC PHoNoGRAPH sT'oP Original Filed Jan. 18. 1928 2 Sheets-Sheet l /5 1 Halver E frenare-e.-

@WMM-4 Feb. 17, 1931. H E, FRACKER 1,792,735

AUTOMAT I C PHONOGRAPH S TOP original Filed Jan. 18. 192s 2 sheets-sheet 2 j I i0 Patented Feb. 17, 1931 narran STATES 'PATENT o Price HENRY E. FRACKER, F PASADENA, CALIFORNIA, ASSIGNOR TO ADO CORPORATION OF AMERICA, OF N EW YORK, N. Y., A CORPSRTION OF DELAWARE AUTOMATIC PHONOGRAPH STOP Application flleivJanuary` 18,1928, Serial No."2fl7,688. Renewed May 1, 1930.

My invention relates to switches, and more Y particularly to a device which may be used for automatically turning off a phonograph when it has completed the playing of a record.

It is'an object of my invention to provide a device which will close an electrical circuit when the predetermined movement of a member is altered.

Such a device finds a particular utility in present-day phonograph, and it is in :this capacity that l shallparticularly describe it without in any way limiting myself thereto. Modern phonographs use disc'records, these records having a long helical groove which starts near the outer edge of the record and continues inward, terminating in an inner groove which is either circular or eccentric.

he reproducer of the instrument carries a needle which is adapted to follow this groove inward until itreaches the inner groove, at which time the needle follows this'groove without progressingr further inward. VIt is desired at this time to have'the mechanism automatically shut down, to replay the record, or to change records. Devices at present available require that the shut-olf or change point be manually determined before the record is played and it is usually necessary to reset Athis mechanism if afdifferent record is to be played, inasmuch as' the inner groove is in 'different positions ondiiferent records. i

lt is an object of my invention to provide 1 a device which will close an electrical circuit when the record has been completely played, this result being accomplished `irrespective of the length of the record. n I accomplish this desirable result by utiliz ing two pairs of contacts connected in an electrical circuit, one pair of contacts being operated by the motor of the phonograph and the other pair of contacts beingalterna-tely 'closed and opened out of phase with the first pair so long as the tone arm is moved over its predetermined inward path. Whenfthe needle reaches the inner groove, the inward movement ofthe tone arm is arrested, at which time the two pairs of contacts 'close in phase thus completing `the circuit through the two pairs of conta-cts. These contacts are connected to an electrically-actuated mea-ns which operates a device adapted to either stop the motor, replay the record, or change the record, depending upon the device controlled by this electrically-actuated means.

It is an object of niyinvention to provide a device having two pairs of contacts which will open and closeout of phase with each other until the vnormal movement of an arm is arrested or altered. V

A. further object of `my invention is to provide a device which will close an'electrical circuit when the normal inward motion of the tone arm is arrested or altered, this device being operative to close said circuit only when the tone arm lies in a predetermined section in its path of travel.

A `further object of my invention is to provide a simple and reliable device for performing a predetermined function when the record of the phonograph has been completely played.

Further Vobjects and advantages of myv invention will be made evident hereinafter. V

Referring to the drawings,-

Fig. l is a perspective view of my invention as appliedto a phonograph. y

Fig. 2 is a ltop'view of my'device as applied to a phonograph. i

F ig. 3 is a view of the stop mechanism of the phonograph taken on the line'S-S of Fig. 2. p

Fig. l is a view taken in the Vdirection'of thejarrow 4 of Fig A i Fig. 5 is an enlarged view of the actuated switch of my invention.

Fig. 6 is a longitudinal sectional view taken on the line 6,-6 of F ig. l.

Fig. 7 is a wiring diagram cf the phonograph incorporating my invention.

Referring toFigs. l and 2, my invention is particularly applicable to a phonograph 10 having an upper tablell. The phonograph l0 is of conventional design and may be eitherV mechanically or electrically actuated. In f' `motorcomprises the driving mechanism. This mo- 1 tor has ashaft lll'which is belt-connectedjto Y an auxiliary shaft 16. This auxiliary shaft carries a suitable speed-governing Vniech'al nism and a worm 17 which is meshed with a worm gear 18 secured to a record shaft 19 which extends upward through the table 11. A suitable turn-table 2O is secured to the up- `ier end of the record shaft, this turn table being adapted to receive a phonograph record 22 having an opening 23 which fits over the record shaft 19. The record 22 has a helical groove starting at a point 24 near the outer periphery thereof and ending in an inner groove 24a which is ordinarily circular or eccentric with the record shaft, this inner groove being spaced between the opening 23 and the outer edge of the record 22. Y

In this helical groove are formed the irregularities which are adapted to actuate a needle 26 as it passes therealong. The needle 26 is carried by a reproducer 27, which is, in turn, mounted on a tone arm 28 of conventional design. As the needle 26 follows the helical groove inward, the tone arm 28 is pivoted in a socket 29 secured to the table 11, the path of the needle 26 being between the point 23 and the inner groove 24. y

Suitably clamped to the tone arm 28 just above the socket 29 is a. cam plate 31 of my `invention. rl`his cam plate has primary and

secondary cam grooves

32 and 33 respectively7 these grooves opening upon one another. The primary groove 32 is formed concentric with the axis of the socket 29 in which the tone arm is pivoted, and the secondary groove 33 is formed so as to extend outward from the primary groove 32 in the manner shown.

Fitting in one of the cam grooves is a pin 35 secured to the end of the lever 38 which forms a part of a controller 38L of my invention. The lever 38 is pivoted about an axis fir-A by means of a pivot structure 39. This pivot structure comprises a flange 4() secured to the table 11, this lia-nge having a hub portion 41 extending upward therefrom. The hub 41 has a pin 42 extending upward therefrom, there being a shoulder 43 between the pin 42 and the hub 41. The lever 38 has an opening 44 which is adapted to fit over the pin 42 so that the lever rests against the shoulder 43. .Vhen the tone arm 28 moves inward from the point 24, as the needle follows the helical groove, the pin 35 engages the primary groove 32. No rotation of the lever 38 about the pivot structure 39 occurs until the needle 26 has passed over an appreciable portion of its inward path. At this time, the pin 35 enters the secondary groove 33. As the needle 26 progresses toward the inner groove 24, the secondary groove 33 guides the pin 35 away from the axis of the socket 29 so as to pivot the lever 38 on the pivot structure 39. The front end of the lever 38 will move in the direction of the arrow 48 of Fig. 1.

An insulated disc 50 of a rotary switch 51 of my invention is also secured to the upper end of the pin 35 above the lever 38. This insulated disc has a contact 53 which is adapted to engage a spring brush 54 secured to the lever 38 fairly soon after the pin has entered the secondary groove 33, this engagement continuing during the remainder of the movement of the tone arm.

An opening 57 through the hub 41 and the pin 42 is adapted to ournal a pin 59 therein, this pin being kept from upward movement in the opening 57 by means of a head 61 litting in a counterbored portion of the opening 57. Secured to the upper end of the pin 59, and resting against the insulated disc 50, but not against the contact 53, is a floating member which is formed as best shown in Figs. 1, 2, and 6. The forward end of the floating member 65 is curved as indicated at 66 and has an eye port-ion 67 formed thereon. This eye portion 67 is adapted to lie immediately above a front end 68 of the lever 38. An elongated opening 7 O in the eye portion 67 is adapted to receive a pin 71 secured to the lever 38. The elongated opening 79 permits a small angular movement of the lever 38 relative to the floating member 65 before the floatinO member is carried along with the lever as the pin 71 contacts the opening 70. Insulated blocks 75 and 76 on the floating member 65 and the lever 38 respectively are adapted to hold a pair of

primary contacts

77 and 78, these contacts being disengaged as the lever 38 draws the floating member 65 in the direcion of the arrow 48, but being closed as the floating member 65 is moved toward the lever 38.

This movement of the floating member 65 toward the lever 38 is accomplished by means of a solenoid 80 mounted in the lever, this solenoid having a core 81 surrounded by a winding 82 in such a manner that when current is passed through the winding the core 81 attracts an armature 83 mounted on the ioating member 65 so as to draw the floating member 65 toward the lever 39, thus closing the

primary contacts

77 and 78.

The solenoid 8O is adapted to be successively energized by a motor-actuated switch 85, which is best shown in Figs. 2 and 5. This switch 85 comprises a cam 86 mounted on the record shaft 19. The cam has a point 87 extending outward therefrom, this point being adapted to momentarily close a pair of

secondary contacts

88 and 89 as the point 87 engages the Contact 89. immediately thereafter, the point 87 engages a contact 99, forcing this contact into engagement with another contact 91 immediately adjacent thereto, the contacts and 91 forming a pair of tertiary contacts. Thus, as long as the motor 13 is energized, the pairs of secondary and tertiary contacts are successively closed, there being a very small time interval between the closing of these two pairs of contacts. It should be noticed that the point 87 must move through a large percentage of its revolution before it can again successively close the secondary and tertiary contacts.v

A transformer 95 is adapted to supply energy to the mechanism of my invention. A'`

secondary 96 of this transformer is connected in a circut 97 which includes the tertiary contacts 90 and 91, and the winding 82 of the solenoid 80. The secondary 96 is also in a circuit indicated by the numeral 98, this circuit including the pair of primary contacts 77 and 7 8, the contact 53 and the brush 54 of the rotary switch 51, the

secondary contacts

88 and 89, and an electrically-actuated means 100. This electrically-actuated means may be adapted to perform any desired function, such as stopping the phonograph motor, replaying the record, changing the record, or otherwise setting into motion any mechanism for performing` a predetermined function. I have shown the electrically-actuated means 100to be in the form of a solenoid having a winding 101 surrounding a core 102. When current is passed through the winding 101, the core is moved so as to actuate a suitable stopping mechainsm 104. One type of stopping 'mechanism is shown in the drawings, and comprises an arm 105 pivoted tothe table 11. The arm 105 carries a friction pad 106 adapted toengage the outer edge of the turn-table 20 to stop the rotation thereof when the electrically-actuated means 1 00 is energized. The type of stopping' mechanism illustrated is adapted to remain in en- Y gagement with the turn-table 20 until manually disengaged by pressing the knob 107 inward, this knob being attached to the lever 104. An arm 109 is pivotally secured to the core 102'of the electrically-actuated means 100. The arm 109 is held in either a retracted or extended position by means of a spring 110. When an electrically-operated vmecha'- nism is used for rotating the turn-table 20,'` it is desirable to shut olf the current there-V through at the instant that thestop mechanism 104 is actuated. This may 'easily be accomplished by inserting a-jack switch115 in series with the motor 13 and the winding of the transformer 951:0 which the motor is connected. The jack switch 115 is adapted-to be operated by means of a' link 116 connecting this jack switch with the core 102.

The operation of my invention. is as follows: i'

A record 22V is placed on the turn-tabe V20 and the stopping mechanism 104 is suitably actuated so as to allow the turn-table 20 to rotate. y The needle26 is then inserted inthe outer end of the helical groove, and is drawn inward in a direction indicated by the arrow 119 of Fig. 1. As the motor 13 rotates, the point 87 closes the secondary-

contacts

88 and 89. Current does not flow through thescircuit 98 at this time, due tothe fact that the

primary contacts

77 and 78 and the contacts of the rotary switch 51 are open. An instant later, the point 87 closes the tertiary contacts 90 and 91, thus sending currentthrough the circuit 97 and thus energizing the solenoid 80. As thesolenoid 80 is energized, the floating member is drawn toward the lever 38, thus closing the primary contacts 7 7 and 78. On the next revolution of the record shaft 19, the above series of operations will be repeated eX- cept that the energizing of the solenoid 80 will not cause the floating member 65 to move toward the lever 38, inasmuch as this lioating member has already been drawn into this position due tothe previous energization of the solenoid.

Thelever 38 thus remains stationary until a substantial portion of the record has been played. 41When the pin 35 enters the secondary cam groove 33, the lever 38 is slowly rotated in a direction indicated by the arrow 48, as previously described. At this time the spring brush 54 comes into contact with the contact 53 of the rotary switch 51 andremains in contact therewith throughout the remaining time that a record is being played. The fioating member 65 will notlmove relative to the lever 38 until the pin 71 engages the end of the elongated opening 70, as previously described. Thus the contacts 7 7 and 7 8 are mo- Ymentarily opened as the lever 38 begins to Y -ing'101, but is broken by the primary `contacts'77 Aand 78 inasmuch as these contacts are open. Should these contacts be closed at this instant, the electrically-actuated meansv would be energized.

Immediately thereafter the tertiary contacts 90 and 91 are closed, thus energizing the circuit 97 .which includes vthe solenoid 80. .i The primary contacts are thus closed at this instant. However, vbefore the. point 87can again close the secondary contacts 88andf89, the movement of thetone arm 28 causes the lever 38 to move, as indicated by the arrow 48, Y

this opening the primary contacts. This sequence of operations continues until the needle 26 reaches the inner circular groove 242L of the record 22. When this occurs, the motor-actuated switch 85 will energize the solenoid 80, thus

closingthe contacts

77 and 78. As the record turns through its next revolution, the lever 38 will not turn, and as the point 87 again closes the

secondary contacts

88 and 89, the circuit from the secondary 96 through the rotary switch 51, the electrically-actuated means 100, and the primary contacts 77 and 7 8 is completed. This will, ofcourse, energize the winding 100 and, in the installation shown, will immediately stop the turn-table 20 and break the circuit throughthe motor 13.

Thus, it should be understood that the secondary and tertiary contacts are successively closed b y the operation of the motor 13. Inasmuch as the solenoid is energized to close the primary contacts every time the tertiary contacts are closed, and inasmuch as the secondary and tertiary contacts are closed out of phase with each other, it follows that the secondary contacts and the primary contacts are also closed out ot' phase with each other. Thus, as long as the lever 88 is moving in the direction of the arrow 4S, the primary and secondary contacts will be closed out of phase with each other, provided that the rotary switch 51 is closed, so that the electricallyactuated means is not energized. As soon as the inward motion of the tone arm 28 is arrested, the primary contacts will remain closed, and upon the next revolution of the motor 18 the electrically-actuated means will be operated, inasmuch as the primary and secondary contacts are then closed in phase with each other.

Should the inner groove 24 be eccentric rather than circular the normal inward motion of the arm 28 will be altered and the primary and secondary contacts will close in phase, thus energizing the actuating means 100.

The rotary switch 51 is provided so that the mechanism will not operate the electricallyactuated means when the needle Q6 is being placed on the record. It is not necessary that this switch be mounted in the pivot structure 89, inasmuch as it is within the scope of my invention to place this switch in any position whereby its contacts are held open until the needle 26 has moved an appreciable distance across the record 22. Y

So, also, it is not necessary that the

cam grooves

32 and 33 be of the specic shape shown. The reason for making the primary groove concentric wit-h the axis of rotation of the tone arm is :tor the purpose of causing the lever 38 to rotate at a greater angular velocity during the period that the tone arm 28 is nearing the circular groove 24a. Also if the

cam grooves

32 and 33 were combined into one simple groove, so as to move the lever 38 throughout the period ot movement ot the tone arm 28, a larger space would be required inasmuch as the swing of the lever 38 would be greater.

It should be understood that my invention is applicable to various other devices besides the phonograph. rllhus, it is Otten desirable to close an electrical circuit when an arm ceases to move or when this movement is slowed down or is altered in any other way, this circuit being closed irrespective of the point at which the normal movement ot the arm changes. rlhus, I am in no way limited to the use ot' my invention attached to a phonogrfnoh.` this installation being` shown merely for the purpose of convenience.

I claim as my invention:

1. In amechanism of the class described, the combination of: an arm; means for moving said arm; a controller actuated by the movement of said arm; contacts carried by said controller; and means tor repeatedly closing said contacts during a movement ol said arm, said contacts remaining closed only when the motion of said arm is altered.

2. In a mechanism of the class described, the combination ot: an arm; means for moving'said arm; a controller actuated by the movementot said arm; contacts carried by said controller; and electromagnetic means 'for repeatedly closing said contacts, said contacts remaining closed only when the motion ot said arm is altered.

8. In a mechanism of the class described, the combiin )n ofl: an arm; means for moving said arm; a lever actuated by said arm; a floating member mounted adjacent to said lever, contacts carried by said lever and said l'loating arm; and means for alternately opening and clo g said cont-acts so long as said is moving.

Il. In a mechanism oi the class described, the combination oiLA an arm; means for moving said arm; a lever actuated by said arm; a loating member mounted adj accnt to said lever; contacts carried by said lever and sai d Heating arm; and means tor drawing said floating member toward said lever at intervals to close said contacts, said contacts being opened when said lever moves away 'from said floating member.

5. In a. mechanism ot the class described, the combination o't': an arm; means tor moving said arm; a lever actuated by aid arm: a floating member mounted adjacent to said lever; contacts carried by said lever and said tical-ing arm; and electromagnetic means for drawing said fioating member toward said lever at intervals to close said contacts, said contacts being opened when said lever moves away from said floating member.

6. In a mechanism of the class described, the. combination of: an arm; means for moving said arm; a lever actuated by said arm; a floating member mounted adjacent to said lever; contacts carried by said lever and said floating arm; a switch adapted to successively close primary and secondary electrical circuits therethrough, said primary circuit including said contacts; and an electromagnet acting between said lever and said floating member, said electromagnet being in said secondary circuit.

7. A combination as defined in claim 6 in which said primary circuit contains an electrically-actuated means ior performing a predetermined function.

8. In a phonograph, the combination of: a driving mechanism; a turn-table adapted to be driven by said driving mechanism; a tone arm, said tone arm being moved by a groove in a record carried by said turn-table;

a pair of primary contacts, said primary contacts being lactuated by said tone arm; a pair of secondary contacts, said secondary contacts being actuated by said driving mechanism; and an electrically-actuated means adapted to act in a predetermined manner when an electric current is passed therethrough, said primary and said secondary contacts being connected in a circuit with said velectrically-actuated means.

9. In a phonograph, the combination of: a driving mechanism; a turn-table adapted to be driven by said c riving mechanism;a tone arm, said Vtone armbeing moved by a groove in a record carried by said turn-table; a pair of primary contacts, said primary contacts being alternately closed and opened as said tone arm is moved ;,a pairof secondary contacts, said secondary contacts being alternately closed and opened out of phase with the opening and closing of said primary contacts by means of said driving mechanism; and an electrically-actuated me ans adapted to act in a predetermined manner when an electric current is passed therethrough, said primary and said secondary contacts being connected in a circuit with said electricallyactuated means. f

10. In a phonograph, the combination of: a driving mechanism; va turn-table adapted to be driven by said driving mechanism; a tone arm, said tone arm being moved by a y groove in a record carried by said turn-table;

a lever adapted to be actuated by the movement of said tone arm; a floating member adjacent to said lever; primary contacts carried by said lever and said floating member; means for repeatedly closing said primary contacts, said primary contacts being opened by a movement of said lever relative to-said floating member; a pair of secondary contacts actuated by said driving mechanism, said secondary contacts being closed out of phase with said primary contacts; and an electrically-actuated means connected in a circuit with said primary and said secondary contacts.

11.- In a phonograph, the combination'of: a driving mechanism; a turn-table adapted to be driven by said driving mechanism; a tone arm, said tone arm being movedby a groove in a record carried by said turn-table;

a pivoted lever adapted to be actuated by the movement of said tone arm; a floating member pivoted to said lever; primary contacts carried by said lever and said floating member; means for repeatedly closing said primary oontacts, said primary contacts being opened by a movement of said lever relative to said floating member; a pair of secondary contacts actuated by said driving mechanism, said secondary contacts being closed out of phase with said primary contacts; and an electrically-actuated means connected in a circuit with said primary and said secondary contacts.

12. A combination as defined in claim 10 in which said means for closing said primary contacts comprises an electromagnet operating between said lever and said floating member, said electromagnet being energized through a pair of tertiary contacts operable by said driving mechanism.

13. Alphonograph comprising a driving mechanism, a turn-table adapted to be driven by said driving mechanism, a tone arm, said tone arm being moved by a groove in a record carried by said turn table, anelectrically actuated means adapted to act in a predetermined manner when an electrical current is passed therethrough, means for passing a current through said electrically actuated means when the normal movement of said tone arm is altered and means for rendering said electrically-actuated Vmeans inoperative until said tone arm has traversed a portion of its path of travel. p

14. A combination as defined in claim 10 in which said circuit includes a rotary switch, said rotary switch being closed only after said tone arm has traversed a portion of its path of travel. Y

15. In a phonograph, the combination of: a driving mechanism; a turn-table adapted to be driven by said driving mechanism; a tone arm, said tone arm being movedby a groove in a record carried by said turn-table; a cam plate secured to said tone arm; a` pivoted lever adapted to be turned'by said cam plate; a floating member pivoted relative to said lever; means for drawing said floating member a distance behind said lever as said lever turns; primary contacts carried by said lever and said floating member; contacts, said primary contacts being opened by a movement of said lever relative to said floating member; a pair of secondary contacts actuated by said driving mechanism said secondary contacts being closed out of phase with said primary contacts; and an electrically-,actuated means connected in a circuit with said primary and said secondary contacts.

16. In a mechanism of the class described, the combination of: an arm; a pair of primary contacts; a pair of secondary contacts; and means for closing said pair of primary contacts and said pair of secondary contacts out of phase with each other so long as said arm is moving in a predetermined manner, said pairs of contacts being closed in phase with each other should the motion of said arm be altered.

17. In a phonograph, a circuit comprising an electrical actuator, a set of primary contacts and a set of secondary contacts; means for alternately closing and opening said primary contacts; means for alternately closing and opening said secondary contacts out of phase with said primary contacts; and means for causing both sets of contacts to close in phase with each other at a predetermined time whereby to energize said electrical actuator.

18. The method of controlling a phonograph which comprises alternately making and breaking a. set of primary contacts in a circuit containing an electrical actuator; alternately making and breaking a set of sec- 10 ondary contacts in said circuit out of phase With said primary contacts; and finally making` both said sets of contacts in phase with each other, thereby bringing said electrical actuator into operation.

19. The method ot controlling a phonograph Which comprises alternately making and breaking a set of primary contacts in a circuit containing an electrical actuator; alternately making and breaking a set of sec- 0 ondary contacts in said circuit ont of phase with said primary contacts While the tone arm of the phonograph is in motion; and finally causing both said sets of contacts to be made in phase with each other when the motion of the tone arm is altered, thereby bringing said electrical actuator into operation.

20. The method of controlling a phonograph which comprises alternately making and breaking a set of primary contacts in a circuit containing an electrical actuator; alternately making and breaking a set of secondary contacts in said circuit out of phase with said primary conta cts While the tone arm 35 of the phonograph is in motion; and finally 4lio causing both said sets of contacts to be made in phase with each other upon cessation of movement of the tone arm, thereby bringing said electrical actuator into operation.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 13th day of January` 1928.

HENRY E. FRACKER.