US2373494A

US2373494A - Automatic control device for

Info

Publication number: US2373494A
Authority: US
Publication date: 1945-04-10
Anticipated expiration: 1962-04-10

Description

April1o,1945. H. NOREN HAL 2,373,494

AUTOMATIC CONTROL DEVICE FOR PHONOGRAPHS Filed Feb. 5, 1943 HeZge NoPe'n 31rd FBZke KyZema Patented Apr. 10, 1945 UNITED STATES OFFICE AUTOMATIC CONTROL DEVICE FOR PHONOGRAPHS Application February 5, 1943, Serial No. 474,872 In Sweden January 16, 1942 3 Claims. (Cl. 274-4) may be imparted thereto.

an oscillating member which tends to actuate a control member but is prevented from this by a blocking member which is adapted to be moved alternately in opposite directions by the oscillating member and by the tone-arm of the gramophone, the arrangement being such that the oscillating member moves the blocking member into an inactive position in which it does not block the oscillating member whereas the tone-arm returns the blocking member to an active position in which it block said oscillating member, this return of the blocking member being effected only as long as the reproducing needle of the tone-arm runs through the sound groove of the record but failing to come about when the re-- producing needle has entered into a concentric end groove. 7

According to the present invention a second inactive position is provided for the blocking member into which position the said member is adapted to be moved when the reproducing needle runs through a groove of higher Ditch than the sound groove. By reason hereof a control impulse is obtained at an earlier moment with records which are provided with a high-pitch groove connecting the sound groove with the concentric end groove.

The invention is described in the followingwith reference to the drawing which shows an embodiment of the invention as applied to a gramophone otherwise not shown in detail.

In the drawing I designates a haft upon which the turntable of the gramophone is mounted. The shaft I is driven by a motor, not shown. On the shaft I there is mounted a gear 2, shown by a dot and dash line. The gear 2 meshes with another gear 3 which is also shown by a dot and dash line. The ratio of gearing between the gears 2 and 3 may suitably be 4 to 1. A cam disc 5 is mounted on the shaft 4 of the gear 3.

An oscillating member consists of an arm 6 which turns on a pivot I. A pin 8 is secured to A helical spring I9 tends to turn the arm 6 counter-clockwise and to keep the roller 9 in contact with the cam disc 5. Thus, when the cam disc 5 rotates the roller 9 follows its contour, and the right end of the arm 6 perform an oscillating movement.

A control member consisting of a bar II displaceable in the direction of it length is arranged near the arm 6 so that it may be actuated by the same and so that a control impulse The bar II is connected to a mechanism, not shown, for causing a record change, said mechanism being so arranged that it is started when the bar II is moved upwardly.- Therecord changing mechanism may be of any suitable kind.

A blocking member is arranged near th right end of the bar 6, said member consisting of an arm 12 which turns on a pivot I3 at its one end. The other end of the arm I2 i providedwith a bent nose I4 and with a short projection I5. The arm I2 is capable of limited movability between two stops I6 and I1.

At its right end the arm 9 is formed with a narrow part I8 and with a projection I9 extending therefrom.

The arm I2 i actuated by a pin 20 secured to an arm ZI which. is coupled by friction to the vertical shaft 22 of a tone-arm, not shown. A stop '23 serves to limit the movement of the arm 2 I.

The mode of operation of the device is as follows: At a certain moment during the playing of a record the member occupy the position shown in the figure. When the shaft I with the turntable rotates, the cam disc 5 is turned coun ter-clockwise. After a complete revolutionof the shaft I the cam disc 5 has turned through 90 so that the lowest part thereof (that with the smallest radius) faces the roller 9. The spring I9 tends to move the arm B upwardly for actuating the bar II but'is prevented from doing this by the projection It on the blocking member l2 which projection is in the path of move ment of the projection I9 on the arm '6. Therefore, no actuation of the bar I I occurs.

When the cam disc 5 is rotated through another 90 the highest part thereof (that with the reatest radius) will face the roller 9. Simultaneously the arm 6 is swung downwardly, the right end thereof striking the bent portion of the nose M on the arm I2 so that this arm is turned to the right and the projection I 5 thereon is moved out of the path of movement of the the arm 6 and on this pin a roller 9 i pivoted. p ojection I9.

During the "following rotation of the cam reproducing needle runs in, the spiral sou d groove of the record.

Thus actuation of the arm ll does not occur as long as the reproducing needle runs through the normal sound groove.

If, however, the reproducing needle enters a concentric end groove of the record the arm I! is not returned, and thus the projection)";

is free to pass by the projection Hi to the left thereof and to actuate the bar II.

If, after the playin of therecord, the roomdueing n e le enters a r ove of hi her pitch than the sound r ove the arm 12 will be'turned v y quickly to th left under theinfluence of them-member 2-1. Durin the time which pa ses after the arm 5 has been moved downwardly and until it is a n moved. too-its uppermost position the arm 2, er fore, will be turned so far to the left that the projection l9 can pass by the projection 15. to the ri ht thereof and actuate the a It T p visionof such a second inaetivepo ition for the blockin member I2 is the chief charac eristic feature oi the present im ventio If the reproducin need e enters an eccentric end gr ov n a e m p ue moordiactuation of the ar H will place-either in one of the ways escribed above or the o her, dependin u o the angular po it on of the cam. disc 5 at wh ch the r producing n ed e passes from the sound roove int the-eccentric end groove.

Since the angle betw en the lowest part of the cam, disc 5 and the highest part thereof issuch as to correspond to one revolution of the turntable l (or to a multiple of one revolution) actuation is secured under all circumstances also with a record having an eccentric end gr ove.

After the record changing mechanism has been started, the oundb x f the tone-arm is raised from the record and; the tone+arm is swung outwardly past the edge of the record. Simultaneously the arm 2| is swung counterclockwise until it strikes the stop 23. When the new record has been Placed upon the turntable the tone-arm is again swung inwardly until its reproducing needle is above the starting groove of the new record. Thepin then again strikes the arm l2, and the above described cycle is repeated when the new record has been played.

What we claim and desire to secure by Letters Patent is:

1. automatic control device :for gramophones havin amovable tone a m ca yin a reproduc ng needlef r obtaimnea'oontrol impulse after a record has been played, comprising a pivoted actuator, means for oscillating the same during playing of the record, a control member actuable by said actuator on completion of playing of a record to produce said impulse, a blocking member movable into positions including an active position blocking movement of said actuator to actuate said control member, and two inactive positions unblocking said movement of said actuator, means on said blocking member engaged bysaid actuator for moving said blocking memberin one direction tion when the reproducing needle runs through agrocve of higher pitch than the normal sound groove.

2. A control device according to claim wherein the blocking member is rotatably mounted and provided with a projection obstructing movement of the actuator only when said blocking member is in the active position, and wherein stop means are provided one on each side of said blocking member and spaced therefrom sufiiciently to allow rotary movement of said blocking member in either direction from said active position into an unblocking position. o

3. An automatic control device for gramophones having a, movable tone arm carrying a reproducing needle for obtaining a control impulse after a record has been played, comprising a pivoted actuator, means for oscillating the same during playing of the record, a control member actuable by said actuator on comple tion of playing of a record to produce said im pluse, a blocking member movable into positions including an active position blocking movement of said actuator to actuate said control member, and two inactive positions unblocking said movement of said actuator, means on said blocking member engaged by said actuator for moving said blocking member in one direction from the blocking to one of said unblocking positions, and means frictionally operated from the tone arm to move said blocking member in the opposite direction into the blocking position as long as the reproducing needle runs through a normal sound groove of the record, and to effect further movement of said blocking member in said opposite direction to said other unblockins position when the reproducing needle runs through a groove of higher pitch than the normal sound. groove.

HZELGE NOREN. FOLKE KYLEMO.