US2374570A - Phonograph pickup arm control mechanism - Google Patents

Description

bril 24, 1945. J. D. WEAVER 2,374,570

.PHONOGRAPH PICKUP ARM CONTROL MECHANISM Original Filed Bed. 6, 1941 2 Sheets-Sheet l INVENTOR ATTORNEY April 24, 1945. D, WEAVER 2,374,570

PHONOGRAPH PICKUP ARM CONTROL MECHANISM Original Filed De e. 6, 1941 2 Sheets-Sheet 2 27 INVENTOR Patented Apr. 24, 1945 PHONOGRAP?I PICKUP ARM CONTROL ECHANISM Jerald D. Weaver, Fort Wayne, Ind., assignmto Farnsworth Television and Radio Corporation,

, a. corporation of Del Original application D 421,891. Divided an aware ecember 6, 1941, Serial No. 11 this application January 11, 1943, Serial No. 471,943

4 Claims.

This invention relates to an automatic phonograph and more particularly to a mechanism for controlling the pickup arm thereof, whereby a mixed assortment oi ten or twelve-inch records may be automatically reproduced, This application is a division of my application Serial No..

421,891, filedDecember 6, 1941, U. 8. Patent No. 2,348,506, granted May 9, 1944, for Automatic record-changing mechanism.

In conventional pickup arm control mechanisms such, for example, as shown in U. S. Patent No. 2,286,490, granted June 16, 1942, the pickup arm is pivotally mounted for vertical and horizontal movement on a rotatable shaft which is rotatably supported by a pedestal fixed to the base plate at one side of the turntable. The rotatable shaft extends below the base plate and has a lever afllxed to its lower end, which is engaged and moved through a predetermined are by a movable member. This movable member is controlled by a cam wheel and normally moves through a predetermined cycle to return the pickup arm into engagement with the initial-playin roove of a ten-inch record. When a twelve-inch record is moved into playing position, the movement of the movable member is arrested when it has swung the pickup arm inwardly to a position over the initial groove of the twelve-inch record.

This is generally accomplished by a mechanism which is associated with the record-supporting means and the cam wheel. When a twelve-inch record is released from its support, this mechanism is actuated and it functions to intercept or arrest the movement of the movable member when it has swung the pickup arm inwardly to a position immediately over the initial groove of a record.

Other types of mechanisms are provided for pcsitioning the pickup arm in engagement with the initial playing groove, of a twelve-inch record. For example, the mechanism shown in U. S. Pat-1 ent No. 2,313,262, granted March 9, 1943, comprises a pivoted lever mounted on the top side of the base plate, adapted to be engaged by the pickup arm as it is swung inwardly and designed to engage the peripheral edge of a twelve-inch record when the pickup arm is moved inwardly to a position immediately over the initial groove of the record.

Each of the above types of pickup arm control mechanisms is expensive in construction and requires considerable space and frequent adjustment.

The object of the present invention is to provide improved pickup arm control mechanism for accurately positioning a pickup arm over the initial playing grooves of records 01' difierent sizes.

' Inaccordance with thepresent invention, there is provided an automatic phonograph which has a rotatable turntable for supporting a record thereon, a pickup arm and a. controlling mechanism for the pickup arm. The controlling mechanism comprises means for elevating the pickup ering it into en agement therewith, means for moving the pickup arm outwardly beyondthe periphery of the record on the turntable and returning it toward the center of the turntable, a lever movablyconnected to the pickup arm and adapted to be moved by the pickup arm elevating means relative to the pickup arm in a plane parallel to the axis of the turntable, and a projection on the lever for engaging the peripheral wall of the'record on the turntable for stopping the return movement of the pickup arm. The projection is-adapted tomove out of engagement with the peripheral wall ofthe record onthe turntable when the picku arm is moved into engagement with it.

For a better understanding ot the invention, together with other and ifurther objects thereof, reference is made-to the following description taken in connection with the accompanying drawings, and its scope w1ll be pointed out in the appended claims.

In the accompanying drawings:

Fig. 1 is a top plan View of the pickup arm mechanism shown partly in section;

Fig. 2 is a fragmentary view, partly in section, showing the mechanism for moving and positioning the pickup arm; and

Fig. 3 is a fragmentary view on line 3-3 of Fig. 2, partly in section, with parts 92, 54 and 51 omitted, showing the mechanism actuated by the pickup moving mechanism while moving the pickup arm to its'outermost position, which funcoutermost position.

Referring now particularly to Figs. 1 and 3 of i the drawings, the invention here illustrated shows a pickup arm control mechanism which includes a base plate I with a well 2 formed therein. A supporting bracket 3 is suitably aiiixed to the underside of the base plate I and is adapted to support tubular bearing element]. The upper end of the bearing element 4 is provided with a flanged portion 5 which in turn is provided with a race for guiding a plurality of ball bearings 6 as 55 shown in Fig. 2. The ball bearings 8 are adapted arm above the record on theturntable and lowtions to move the pickup arm inwardly from its to rotatably support a flanged tubular shaft! by engaging the bottom of the flanged portion thereof. The tubular portion of the shaft I extends downwardly'into the tubular bearing element 4.

A turntable II is fixed to the flanged portion of the shaft 1 to rotate therewith as shown in Fig. 2. A stack of records I2 may be uspported on the turntable II and the records are maintained in lever 3| which is connected to the shaft 22 is of t tubular construction and the lower end thereof is notched at 32 in such a manner that the ear 30 may come into engagement therewith for roa centered position by a, spindle I3 rotatable with the turntable I I. Teeth 3 are providedon tubular element 4 for the purpose of elevating and lowering the turntable as is fully explained in United States Patent No. 2,348,506, granted May I 9, 1944. "I'he turntable may be driven by any suitable mechanism such as, for example, that disclosed in United States Patent No.

2,012,185, ranted August 20, 1935,

tating with the lever 3| in ahorizontal plane. When the lever 23 is moved in a counterclockwise direction from the position shown in Fig. 3, it moves therewith the lever 3| in thesame direction.

Asv shown in Fig. 3, a member 33 is pivotally supported by a bracket 34 which may be secured 1 in o suitablemanner'to the bottom of the base,

plate Ill. The member 33 is maintained in the position shown by a spring 36 connected to the bottom of thebase plate I as at 35 and to the f ,member 33. The member 33 corresponds to A pickup arm I3 is mounted for vertical and horizontal movement on apedestai II which is fixed to the base plate I at one side of the tummember 92 in the above-identified copending-application and its function is fully described therein. The-free end of the pivotal member 33 is connected to one end'of a member 31. by a contable'll, as shown in Fig. 1. For example, see U. S. Patent No. 2,313,262, granted March 9, 1943.

At the free end of the pickup arm I3 there is provided a reproduceror a pickup Ilwitha stylus I3-for cooperatingwith a record on the turntable to reproduce the record, as shown in Fig. 1.

. Intermediate the ends of the pickup arm I3 there is pivotally connected thereto a lever I], shown in Figs. 1 and 3. To one end of the lever l1 there is amxed a downwardly extending pin I3. A spring 20 is connected to the lever I I in the manner shown in Fig. 2 to maintain the lever I'lin the full-line position shown in that figure. For supporting lever 11, there is provided a pivot pin I9 which extends through a pair of tumednecting link 38. Intermediate its ends the member 31 is pivoted as at, 33 in a suitable ,mannerto the baseplate I. The opposite end of the pivotal member 31 is connected to lever 3| by a spring-biased coupling member 40 pivotally connected to member 31, and member I. The compression member 4| includes a tubular member 42, one end of which is connected in a suitable manner to the member 40, and the otherend of which is connected to a pin 44. The pin I3 is provided with a collar 45 which is adapted to slide within the housing 42. A compression coil spring 41 is provided in the tubular housing 42,

one end abutting the end of the housing 42 and the opposite'end being engaged by the collar II.

down ears n' on lever n into the side walls or pickup arm I 3. The convolutlons 2| of spring 20 are supported by'pin I 3 whereby to anchor the spring. As willbe evident from the following description, when theraised pickup arm I3 is moved from its outermost position toward the turntable I I and the uppermost record on the turntable is a 12-inch record, the pin I3 will extend into the plane of the 12-inch record, and

serve to position the stylus I I of the pickup arm I3 overithe initial playing groove of that record. The end of the pickup arm I3 that rests on I the pedestal I4 hasconnected thereto a tubular shaft '22 which extends downwardly through the pedestal II and below" the base plate I. A lever I lever 23 has afiixed thereto a downwardly extending pin 2|. Thereis provided'a'cam surface 23 on a cam wheel 21 for engaging pin 23 and imparting horizontal movement thereto; The

- cam wheel 21 is fixed to a shaft 23 which is rotatably mounted in a suitable bracket 23 fixed to the bottom of thebase plate I. The shaft plained, the members 31 and 33 are moved ina 23 may be driven by any suitable motor and gear 7 mechanism known in the art such, for example,

" as that shown in United States Patent No.

2,012,185,- patented August 20, 1935.

The upper end of the tubular portion of the.

lever 23 ha aflixedthereto a'n,ear 33. A lever 3l' is connected to the shaft 22 above thetubular thatthe lever 3I may be moved in a horizontal plane relative to the shaft :2. The end or the portion of the lever 23in a suitable manner so The opposite end of the pin 44 is connected'to the free end of the lever 3| previously described.

When the lever 3| is moved in a counterciockwise direction (Fig. 3)'as has been previously excorresponding' direction. The member ll corresponds to member. in the copending application and its function is described therein.

Thereis provided a pm so within the tubular shaft-, ;2 2 for engaging one end of the lever l'|= and pivoting it ina counterclockwise direction (Fig. :2).- Near' the lower end of the. pin 33 there .is/ provided a collar or flanged portion II which? is adapted to engage the bottom of the tubular portion of the lever 23 when the pin 33 is raised" thereby to move the lever 23 ina vertical plane 4 relative to the shaft 22.

The-lower end of the pin. It rests on a lever52, one end of which is pivotally connected to a brackethlby a pinll."

The bracket 531s fixed to the bottom of thebase platel in a manner illustrated in Fig. 2. The 1 opposite end of the lever 52 supports a roller-I1 peripheral surface which is adapted to rest on a 53 of the cam wheel '2"|. When a record on the turntable II isbeing reproduced, the cam wheel 21 remains stationary inthe position shown in Fig. 2. When the pick-- up arm I3 reaches the tripping groove of a record being; reproduced, a tripping mechanism ,(not shown) initiates the rotation of the shaft 23 through one revolution. The tripping mecha- P nism disclosed in United States Patent No.

2,018,881, patented October 29, 1935, may lie incorporated with the driving mechanism previous-- ly refeired to for initiating the'rotation of the shaft 2 The first operation which the cam wheel 21 performs during its cycle of rotation, isto elevate the stylus I6 of the pickup arm l3. out of engagement with a. record being reproduced. This is.

brought about by the cam surface 58A moving into engagement with the roller 51 and raising the lever 52 and therewith the pin 50. When the pin 50 is raised, it pivots the lever I! to lower pin II to the dotted line position and to lift the pickup arm I3 and therewith the stylus I6 out of engagement with the record on the turntable. After the stylus I6 of the pickup'arm I3 is raised out of engagement with a record on the turntable II, the roller 51 is in engagement with the suriace 58 and the pickup arm I3 is maintained in its raised position. Surface 58 of cam 21 is dimensioned to lift the pin' 50 far enough so that pin I8 as well as the stylus is lifted clear of the record. Thereafter, the portion 26A of the cam surface 28 (Fig. 3) engages the pin 24 and moves it, together with the lever 23. in a counterclockwise direction (Fig. 3).- When the lever 23 is thus moved after the pin 50 is in its raised position, the ear 30 is in position to enter notch 32 and move the lever 3I and therewith the member 33 (Fig. 3) in a counterclockwise direction. The counterclockwise movement of the lever 23 rotates the tubular shaft 22 and swings the pickup arm I 3 in a counterclockwise direction (Fig. l) to a position beyond the edge of the record on'the turntable.

After the cam surface 26A moves out of engagement with the pin 24; the pin 24 is main- I tained inan outermost position by the cam surface 26. When the inclined .portion 260 of the cam surface 26 moves into the path of the pin 24, the levers 23 and 3I are moved in a clockwise direction (Fig. 3) under the biasing action of-:the-

spring member 38. a The ear .30 and thenotch 32 are so arranged that the lever 23 will be moved in a clockwise direction (Fig. 3) sufliciently far to position the stylus of the pickup arm I3 over' the initial playing groove of a -inch record. However, as has been explained before, if the uppermost record on the turntable is a l2-inch record. the peripheral edge of the record will I engage the pin I8 in its lowered position and stop the movement of the pickup arm so that the stylus I l is positioned over the initial playing groove of the 12-inch record.

As the pickup arm I3 is being. moved from its outermost position to a position over the initial playing groove of a record, the eccentric portion 383 of the cam'wheel 21 is in engagement with 'the roller 51. As this eccentric portion 583 may be made therein without departing from the I invention, and it is, therefore, aimed in the appended claims tocover all such changes and modications as fall within the true spirit and scope of the invention.

What is claimed is:

1. In an automatic phonograph having a rotatable turntable, and a pickup arm for reproducing a record on said turntable; pickup arm control means for positioning said pickuparm at the beginning of a record on said turntable comprising means for elevating said pickup arm above the record on said turntable and lowering it into engagement therewith; means for moving said pickup arm outwardly beyond the periphery of the record on saidturntable. and returning it toward the center'of said-turntable; a lever movably connected to said pickup arm and adapted to be moved by said pickup arm elevating means relative to 'saidpickup arm in a plane parallel to the axis of said turntable; and a projection on said lever for engaging the peripheral edge of -the record on said turntable for stopping the return movement of said pickup arm, said projection being adapted to move out of engagement with the peripheral edge of the record on said f turntable when said pickup arm is moved into moves, it gradually lowers the lever 52 and therewith the pickup arm I3. Thus pin I8 is lowered sumciently to engage the outer edge of a 12-inch record. When the stylus I6 of the pickup arm I3 is over the initial playing groove of a top record on'the turntable, the portion 586 moves into the path of the roller 51 permitting the lever 52 and the pin SIl to lower the stylus I 6 of the pickup arm I3 into engagement with the initial playing groove and to permit the lever. I! and the pin I8 to return to the full-line position shown in Fig. 2. When the lever 52 (Fig. 2) functions to lower the stylus I6 into engagement with the record on the turntablel I, the lever 23 is pe itted to move vertically downward out of engagement with the lever 3 I. Thereafter, the rotation of the the pickup arm I3 is permitted to move freely camwheel 21 and the shaft 28 is stopped, and

over the surface of the record as the stylus l6 tracks the playing grooves.

While there has been described what is at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications engagement with the record.

2. In an automatic phonograph having a rotatable turntable, and a pickup arm for reproducing a record on said turntable; pickup arm control means for positioning said pickup arm at the beginning of a record onv said turntable comprising means for elevating said pickup arm above the record on said turntable and lowering it into engagement therewith; means for moving said pickup arm outwardly beyond the periphery of the record on said turntable and returning it toward the center of said turntable; a lever movably connected to said pickup arm and adapted to be moved by said pickup arm elevating means relative to said pickup arm in a plane parallel to the axis of said turntable; a projection on said lever for engaging the peripheral edge of the record on said turntable for stopping the inward movement of said pickup arm, and means operatively associated with said lever for moving said projection out of engagement with the peripheral edge of the record on said turntable when saidpickup arm is moved into engagement withthe record.

3. In an automatic phonograph having a rotatable turntable and a pickup arm for reproducing a record on said turntable; pickup arm control means for positioning said pickup arm at the beginning of a record on said turntable comprising means for elevating said pickup arm above the'record on said turntable and lowering it into engagement therewith, said means including a movable pin; means for moving said pickup arm outwardly beyond the periphery of the record on said turntable and returning it toward the center of said turntable; a spring-biased lever movably connected to said pickup arm and adapted .to be moved by said pin relative to said pickup arm in a. plane parallel'fi'l the axis'ol' said turntable; and a projection on said lever for engaging the peripheral wallet thenrecord on said turntable for stopping the inward-movement oi.

said pickup arm, said projection beingadaptedto move out of engagement with the peripheral wall of the record on said turntable when safe pickup arm is moved into engagement with the record.

4. In an automatic phonograph having a rotatable turntable, and a pickup arm for reproducing a record on said turntable; pickup arm control means for positioning said pickup arm at the beginning of a record on saidturntable comprising means for elevating said pickup arm above the record on said turntable and lowering itinto engagement therewith; means for moving said pickup arm outwardly beyond the periphery of the record on said turntable and returning it toward the center of said turntable, and means operativeiy associated with said pickup arm and said pickup arm elevating means and movable thereby 'toproject below said pickup arm for engaging the peripheral edge of therecord on said turntable for stopping the inward movement of said pickup arm.

/ JERALD D. WEAVER.

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