US1232807A - Tone-arm. - Google Patents

Description

l. JONASSON.

TONE ARM. APPLICATION FILED ;AN.6. 1917.

LSUY., Patented July 10, 1917..

ZU( me@ Iyewom types ot records.

facon Jonassen, onions Moines', iowa.

TON 15J-ARM.

Specification of .Letters Patent.

Application tiled January 6, 1917. Serial No. 140,962.

an adjustable tone arnf ot simple and inexpensive construction tor `carrying the sound box oit a talking maelnne.

l `further obgeetis to provide such a tone Varm havingadj ustahle means tor supporting the sound box whieh earl-ies the stylus, capa-v ble of adjustment7 so Athat the device may .heused tor playing either type ot record whether the sound grooves are ot the kind having the" up and down waves or the kind having the lateral waves, so that in using either record the record will he carried past the stylus with the. groove traveling i-n a path atthev point where the stylus engages it, which is'radial oic the Circle on which 'the stylus swings, so that the stylus will Vnot drag against the side ot the groove.

ilyinvention consists in the eonstruetion, arrangement and combinationot thevarious parts ot the device` wherehy the ohjeets Conteninlated are attained, as hereinatter more fully settorth. pointed out in my claims and illustrated in the accompanying drawings. in which Figure l shows a top or plan view of my improvedtone arm, the dotted linesA showiiip` the sound box in itsv adjusted position.

l Fig showsa side elevation ot the saine7 theitull lines showing the sound holt in one of its adjusted positions, and the dotted lines showing it in-an'ot-her position, and

Fig. 3 `shows a side elevation ot' the tone arm with. the sou/nd box adjusted tor use with a dilterent type of record. the dotted lines showing the sound box in an adjusted position.

It may he explainedin a preliminary wav thatv there are a nuniher ot tone arms having the sound box adjustahly mounted thereon, on a sort of crank arin tor adji'istiuent to positions for playing either ot the common The diliieuity involved in the use ot suoli an adjustable tone arm arises `from the fact tl at if the tone arm is properlyv adjusted tor use with one type ot record. then when it isy swung on its crank arui support quarter revolution, the stylus. instead ot' traveling smoothly in the groove ot`tlie portion l-e extending upwardly and sound'loox '1st, which Carries the record, will tend to drag against the side thereof. This dillieulty i have souaht to solve hy my construction herein shoiin.

In `the aeconipanying drawings. l have used the reference numeral l-f'l to'iiidieate generally a tubular anni forming partvotl my improved tone arni.- ilidaliilv tatablymounted in the end ot the tube l() is a tubular tone arm member li lui-vine` atits .forward end a portion l2, which ini'one position. et the device. extends downwardly and away :from the tuhular nieuiher lO. i

:it the lower end of thev extension l2 is a awav from the portion l2 at sulistantiallv .rightiangles thereto, and supporting an firdiiiary u stylus or needle le I Formed in the tubular nieinher l0 is a eircuinterentially elongated slot lo. EX tending rearwardly and slightly downwardlv from the slot 1G is a slot 1S at the rear end lot which is an upward extension lf) on the horizontal level with the upper end ot' the slot 1G. I

The portion 12 is iliade of two parts telestopieally connected. the lower portion heing eapa'hle ot limited rotary motion with,

relation to the upper portionl 4 The lower portion isprovided with a pin 2() whieh travels in a rireuniterentially elongated slot in the upper portionto permit a vpiarter revolution ot the lower portion oli the part l2 with relation tothe upper portion thereof.

in Fig. l. I have shown a record disk 22. having the sound grooves 23, y

ltwill he understood that in Aordinz'iiv talking machines, the tone arm ma v lie swung horizontally and in Fig. l, .l 'have shown the line 2l to indicate the are ot a eirele on which the stylus la travels during such horizontal swinging movement ofthe' tone arm.

In this connection it ma)y he stated that the tone arm and stylus should he so eoiistruoted and arranged and. located with relation to the record disk ""2 that the sound groove 23, in which the stylus is traveling. will at the point where the stylus lori-ated, always he traveling substantially in a line radially of the Circle oi which the line forms an are lWhen this eoiistruetion is followed, the stylus will never drag aiguii-ist the side of the sound groove. The line 2li passes through the Center ot the disk.

Retords are made generally of two types and iop in which the sound groove has up and down waves-or lateral waves. It is desirable that tone arms be supplied with which either lrecord may be played.

-the stylus is in proper position with rela-r` tion for properly playing one type of disk, it will be seen that when a, quarter turnis vgiven to the sound box in the lower portion of the member 12, the stylus, instead of being then in the proper position with l'relation tothe grooves of the record, will lso be in posi-tion so that it tends to drag against `the side of the sound wave groove.

'n Fig. 1, I have shown in full lines a stylus in propeinpositionl for playing the record having the up and down siind wave grooves.

If then it is, desired to play records hav-v ing the other type t grooves, and the lower part of the memberv 12 turned a, quarter revolution, it will be seen `that the stylus would then be in the vline 25 and would t'iid to drag against thetside of the groove.4 `.It the tone. arm were?adjusted dr constructed so that \\'lien'-iii.tlie position shown 'in Fig. 3. the styl'iisbwou/ld be located in aline 2, then it' the portion V1i were .given a quarter turn, bringinff the'sound box to the positions showin in 1 and 2, the stylus would be in the' line-26 and wouldy tend to drag against the side of the sound I have. therefore, constructed my tone arm` as shown, so that. when the sound box isgiven a quarter turn .tiom'tlie position Shown in F ig. 1,to 'fthe position shown lin -Fig 3, the member 11 may be vpushed out Wardly from its positionssliown in'Figs. 1 and 2 to posi'tion shown in Fig. 3, so,v that the stylus may, in both positions of the soundbox, and for playing both st vles of records, be in' the linelfffhe extension simple construction 'and permits 19 serves vto locltthe member 11 against longitudinal sliding movement f during the operationof the machine. n ,My improved device ot extifeiiiel'y fthe'lomid tion of" the st vlus at all times in proper position with. relation to the record..

Sonie changes may be madein the yconstruotionand arrangement ot in v improved f I In a playing arm having a reproduc- 'tube whereby the two ends/0f the longidevice, without departing -froin the essen'- t-ial features and purposes of my invention', and it is my intention to coveii by my present application any such changes in con,A p struction or use of lmechanical equivalents which may be includedl within the reasonable scope of the claims of my patent;v

. I claim as my invention:

1. In a device of thevlclass described, a tubular, two part tone arm having the `tor-, ward portion telescopic-ally received within the rearward portion; the rearward portion having an L shaped slot therein with an engaging notch at the rear end of the longitudinal arm of said slot, a pin mounted 'on the forward portionof saidarm' andadapted to coact with said slot whereby the movable'() portion of the tone arm may be moved lon'gi'- tudinally7 between two predetermined p`ositions and may also be rotated relative to the stationary portion of the tone arm. i

2. In a devicevot the' class described,` 4a horizontally disposed tube adapted to form a part of a tone arm having a substantially L shaped slot therein, the longitudinal portion of the slot havinganengaging notch. at one end and being inclined upwardly from said notch, asecond"`tube adapted .to be telescopically received inthe `first, and a pin fixed in the last tube andadapted to be received in the slot in the first tube where-s by the second tube may be permitted loiigi- 95 tudinal movement rela'tive to thel tirst tube' between two predetermined limits and rotary movement from one ot its-longitudinal positions.

ing mechanism thereon adapted-v to coperate with reco-rds of'both the undulating and lateral wave types, a Hxed tube having a longitudinal slot therein' inclined upwardly toward the free end and provided ptits other end with an upwardly extending notch. the upper'Y end of the longitudinal slot being extended circumferentially otl the` tudinal portion of the slot `are adapted to 110 cooperate with a pin to lock` t/lie pin in position, a second vtube adapted to be slidably and rotatably received.\'vitliiii the first tube andto have lthe reproducing ii'iech'anism sef cured to its ktree end. and a pin extended pinis at a position adjacent to the upper end of `the. longitudinal portion of' the slot, Desfllfoiiies, I owa. December 26, 191.6!!

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