US2061224A - Tracking device for gramophone sound recording attachments - Google Patents

Description

Nov. 17, 1936. A, DE RATS 2,061,224

TRACKING DEVICE FOR GRAMOPHONE SOUND RECORDING ATTACHMENTS Filed March 9, 1935 2 Sheets-Sheet 1 Fig. 1.

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TRACKING DEVICE FOR GRAMEgON SOUND RECORDING ATTACHMENTS Filed March 9, 1935 2 Shets-Sheei} 2 v: g i I Patented Nov. 17, 1936.

UNITED STATES PATENT OFFICE TRACKING DEVICE FOR GRAMOPHONE SOUND RECORDING ATTACHMENTS "Achllie mamas, London, England,

or to assign Acoustograph Limited, London, England, a company of Great Britain Application March 9, 1935, Serial In Great Britain March 17,

13 Claims. (Cl. "4-13) mechanism rendering the machine adaptable,

at will for the recording of sounds upon blank discs without impairing anyintended reproduction of sounds therein from inscribed records, acoustically or electrically.

The invention is concerned more especially with the means to be employed for traversing the recorder positively across the face of the disc to form the customary spiral sound track during the process of making records and aims at the provision of simple, effective and inexpensive means which can be applied to any gramophone or radiogramophone machine of conventional dea sign and which can be put in or out of recording gear in situ by merely actuating a switch lever or the like thereby rendering the operation of extreme simplicity which is of the highest importance in the art.

An incidental object of thislnvention is the provision of a tone arm or pick up arm traversing means which when applied to a gramophone will be imobtrusive and will present no obstruction to the placing of record discs upon or the removal of same from the turntable or the easy manipulation of the tone .arm as is required in the normal operation of the machine.

A still further object of'my invention is the provision of improved control means in a recording attachment of the nature indicated adapted especially for use in connection with gramophones embodying an electric amplifier and a' tone arm or pick-up which is equally serviceable for recording and reproducing-such control means serving to reduce to a minimum the manipulations required in changing the machine from the conditions required in recording to those required in' reproducing and vice versa.

The present invention is hereinafter more fully described with reference. to the accompanying drawingswherein certain practical embodiments thereof-are illustrated by way of example.

In these drawings:-

. Figs. 1 and 2 show in side elevation and plan respectively the main parts of a gramophone having my. improved traversing mechanism applied. v I

Fig. 3 is a fragmentary plan view of a modified arrangement of the threaded sector element.

Fig. 4 is a section on the line 4-4 of Fig. 3; Fig. 5 is a plan view showing a modified arrangement wherein the traversing arm bearing 5 the threaded sector is made displaceable from a position in line with the tone arm tov an angular position to facilitate stowage of the sound box. Fig. 6 is a fragmentary elevation partly in section and on a larger scale showing the connec- 10 tion of the traversing arm to the tone arm.

Fig. "I is a partial plan view showing a preferred arrangement of the invention wherein the leading screw is urged resiliently towards the threaded sector.

Fig. 8 is a front elevation illustratingthe leading screw and its drive means, as in the example shown in Figs. 1 and 2.

Fig. 9 is a fragmentary plan and Fig. 10 an elevation; these figures showing alternative drive means for the leading screw. I

Fig. 11 is a fragmentary plan view showing a modified form of threaded element engaged with the screw;

Figure. 12 is a diagram showing the application 25 of a switch unit to an electric phonograph havin radio connections and illustrating the connection of such unit with the mechanism particularly illustrated in Figure 7 for connecting or disconnecting the leading screw and sector element.

Referring to Figs. 1 and 2 of the drawings, it will be seen that (1 represents the rotary turntable of a gramophone of conventional design, while b represents the tone arm which is pivoted in a collar b in a manner whereby it is free to swing in a plane parallel to the face of the tumtable, said tone arm bearing at its free end a vertically swinging swan-neck c to which is attached the sound head d, which latter may be of acoustic or electric type as preferred, and may be especially constructed to render it suitable for recording or reproducing or for both purposes.

The improvements constituting the subject of the present invention include a leading screw e of fine pitch, supported in suitable bearings e e in a position beneath the turntable a, a guide arm I attached to the tone arm and projecting beneath the turntable and a movable chaser element a supported on the guide arm and adapted to coact with the leading screw e when it is required to traverse the sound head positively across the face of a revolving record blank supported upon the turntable.

In the example under consideration, the leading screw is disposed radially with reference to the turntable spindle ami on a line at right angles to the direction of the guide arm 1 when in its medial position. A bevel pinion e aflixed to the inner end of the leading screw meshes with a corresponding crown wheel e keyed or otherwise fixed to the turntable spindle a whereby the screw will be caused to rotate, at all times the tiuntable is in operation. I

a The guide arm f in. Figs. 1 and 2 comprises a length of strip. material fixedly attached to the underside of the tone arm b at a point adjacent its bearing collar and bent in cranked form whereby it projects beneath the turntable to wards the leading screw while the tone arm is in its normal operating position. Arranged to slide on the free end of this guide arm I is a channel-shaped extension h to which an arcuate 'sector-shaped'nut element a of fibre, leather or other suitable self-threading material is secured.

The operative face of the threaded sector 11 is preferably recessed as shown in Fig. 4 to con- .form to thesurface of the leading screw e. The channel shaped extension h is attached to the guide arm by screws f engaged in. elongated slots in the extension and a tension spring h stretched between a lug h on the extension and quired a lever i pivoted uponthe cranked part of the guide arm I is provided with a cam: i arranged to act upon a lug 7' oifset from a rod 1, which ismounted to slide in brackets attached to I the guide am i and is operatively connected to the extension it. As will be imderstood, on pressing the-lever i in a forward and downward direction the cam 2 will be caused to force back the lug 7' whereupon the rod will pull upon the spring infiuencedextension and retract the sector from contact with'the leading screw, thus 45.

horizontal plane.

leaving the tone arm free for movement in a When however it is required to record sound upon a blank disc supported on the turntable, the sound head is set upon .the disc in an appropriate position near the periphery thereof and the lever i is lifted to the position shown as the machineis started, so that the threaded sector is pressed against and main- "ment, which is sector shaped as previously described, is pivotally attached near onefofits ends to the free extremity of'the guide arm I and a spring h ofany suitable type is engaged withthe parts in. such a way as to'urge the chaser outwardly towards the leading screw e.

A retracting rod 1" operated as previously dewill serve to withdraw the sector from engagement with the screw. v

As is well known with many gram'ophones and especially. those of. the portable type arranges ing the case, the tone arm is swung clear of the turntable and the sound head is lowered into a depression somewhat as shown in Fig. 5. In applying this invention to such machines it will be found convenient to arrange for a pivotal movement of the guide arm f in relation to the tone arm so that the operative end of the guide arm and its threaded sector may be displaced from its normal position beneath the sound box on 0ccasions when the-machine is being closed after use. For this reason therefore the guide arm 1 is pivotally connected to a bracket k afiixed to the tone arm and is held stiflly in its working position by a spring catch it engaging a depression in the face of the arm f while a projecting shoulder 1 formed on the arm j abutting against a stop lug k on the bracket definitely limits the pivotal motion in one direction. When swinging the tone arm to the rear for the purpose of stowing the soundbox the guide arm I is arrested by contact with a fixed post 2 and is thus displaced somewhat as shown in Fig. 5 leaving the sound head free to be lowered into its housing. On turning the tone arm outwardly to bring the ma-v chine into operation, the guide arm abuts-against a second fixed post 2 which causes the arm to resume its normal or working position in relation to the tone arm. I

In the preferred arrangements shown in Fig. 7

guide arm f, whilst the leading screw'e is urged toward said sector in order to maintain operative engagement between the parts. For this pur-.

pose the leading screw, e driven by bevel or other suitable gearing as preferred is mounted in bearings on a frame e which is capable ofpivotal motion about the turntable spindle a, while .a

fixed post on the base tends to pull the leading screw in the direction of the sector 9. To enable the traversing mechanism to be put into and out of operation as required a hand actuated cam q is provided in one position of adjustment to retract the leading screw clear of the path of the sector g and in another position of adjustment to leave the screw free to be pressed against the sector. In thee constructional example illustrated the cam q acts directly upon a lever q which is linked-to the pivoted frame e by the member q while the cam is arranged .to be manipulated by the handle or turnbutton q.

This retracting mechanism can however be arranged in other ways without departure from the essentials of myinvention.

In Fig. 11, I have illustrated a half nut g of straight form pivotally attached to the slide h mounted on the traversing arm 1, the slide being urged outward by a spring h as illustrated in Figs. 1 and 2,-so that the threaded element 9 may be caused to follow a rectilinear path paralid to the axis of the lead screw e during the pivsity of using the slide it or' the spring h.

It should moreover be understood that I may prefer in certain instances to mount the guide arm I detachablt'r upon the tone or pick up arm in -order that it may be dismantled and removed therefrom when not required for use.- The means employed for this purpose however is not deemed ments are frequently made whereby prior to clos to require illustration as various lmown coupling the threaded sector 9 is mounted fixedly upon the 3 or clamping devices may be utilized to that end without encountering any difiiculty.

lhe gearing employed for driving the leading screw e may be modified in various ways without departing from the essentials of this invention.

as shown in Fig. 9. In both these arrangements the leading screw e is supported in fixed bearings 2 e Fig. illustrates a further modifies. -v tion in wliich the leading screw is fitted with a friction wheel n engaging the underside of the turntable a, while the bearings for the screw are pivotally supported at the outer end at o and pressed upwardly at the inner end by a spring 0 in order to maintain proper contact between the frictionally-engagedparts. I

lit-will readily be appreciated that my improved recording attachment is applicable to gramophones of conventional design generally whether equipped with acoustic or electric recording and/or reproducing heads or both. When howi ever theinvention is applied to a machine incorporatlng an electric amplifier and a pick-up utilizable either as a recorder or a reproducer, it will be preferred in accordance with this invention to connect an electric switch directly with the I I from the input to the output end of the amplifier and vice-versa. For this P p one may em ploy atwo-position change-over electrical switch and couple the same to the lever, turn button or other device provided for throwing the recording attachment into and out-oi operative engagement,

the electrical change over switch being arranged" at the same time to transfer the pick-up from the input to the output end 01' the amplifier and vice versa in a manner well understood in connection with electrically operated gramophones.

Such a construction is illustrated in Figure 12,

showing as an example, a switch of the kind referred to. applied to a mechanism of the type shown in figure 7;; the figure showing the switch in its arrangement for recording. As will be seen from this figure, the turnbutton q for throwing the recording mechanism into or out of gear is extended in the form of a spindle o and connected to the movable vpart of a two-position switch designated generally 1', whose function is to. con trol the connections between the pick-up and the amplifier. Each. switch may have a pair of switch arms 1 and 1' which are mounted upon the spindie or. Disposed adjacent one pair of switch arms are the terminals u, o and w. A like set. ofterminals u 2: and to! are disposedadiacent the other pair of switch arms. which other arms are opposed iii-direction to the first switch arms; as.

illustrated. In the diagrammatic view-of Figure 12, the terminals 11 and u are diagrammatically illustrated as connected at the centers of the arms 1' and 1 These contacts at and u for both switches are connected; tothe piclc-up t. The contacts w and 10 are connected to the output ter- When the switches are arranged, asshown in Figure 12, the instrument is ready for recording and the sector-shaped element is engaged with the leading screw. It will be obvious that when the instrument is to. be used for reproducing, the

actuation otthe spindle q. for the purpose or sep-- ceived on an associated radio receiver, (3) as an ordinary radio receiver or (4) as a recording gramophone operating in response to sounds applied to a microphone. For this purpose use may I he-made of a four position electric switch adapted in its various positions to bring about the requisite connections between the amplifier, the pick-up, the radio receiver and the microphone, said switch being operhtively connected with the means throwing the traversihg mechanism into and out of gear whereby they may be actuated together from one point. The coupling together of these twocontrol members aifordsamarked advantage in combined recording and reproducing gramophones as here considered. Further for convenience in operation it will frequently be found desirable to arrange the electric switch and the control means at some distance. from the tone armor pick-up It is to be understood that by the term phono graph? as used in. the claims, I intend to include any form of sramophone, radio gramophone. phonograph or radio phonograph, in other words, any form of device for translating voice vibrations into a record track or translating the record track into soundivibrations, in which machine a turntable is used disposed above a motorboard and having a tone arm-carrying either a reproducing head or a recording head and extending reproducing sound box diametrically across the turntable and a s'pindleon which the turntable is carried and extending through the motorboard, of"

a traversing attached to the tone arm and extending downward outward of the edge of the turntable and then inward between the turntable and the motorboard, a screw disposed between the turntable and the motorboard and having driving engagement with the spindle and extending therefrom to apoint adjacent the rim of the turntable,

an element carried by the traversing arm and yieldingly bearins'against the screwand having threaded engagement therewith, and manually operable means for shifting the screw and element relative 'toeach other in ahorizontal plane beneath the turntable to engage or disengage 2. attachment for phonographs which have a mot'orboard," a turntable, a spindle therefor, and

A atone arm extending over the turntable, the atminals s of the amplifier 3 while the input terminals s are connected to the contacts 12 and 10 tachment including a. traversing arm detachably engaged at one'end with the tone arm to turn therewith as the tone arm moves from the rim of the-turntable towards the center thereof, the

table and. the motor board, a screw disposed horizontally between the turntable and the motor- 4g turntable and beneath the same and o arm connected to rim the tone arm for movement therewith as the center thereof.

board and having operative driving engagement with the spindle of the turntable, an element, on the traversing arm having threaded engagement with the screw, and manually operable means for shifting the screw and element in a horizontal plane relative to each other to engage or disengage the element and the screw.

3. In a recording attachment for phonographs. the phonograph having a turntable and a pivoted tone arm; a screw driven in consonance with the turntable, a traversing arm connected to the tone arm for movement therewith as the tone arm moves from the rim of the turntable towards.

the center thereof, a threaded element mounted on the traversing arm for movement in the plane of the traversing arm toward or from the screw. a spring urging the element toward the screw, and manually operable means for retracting said element.

4. In a recording attachment for 'phonograph l the phonograph having a turntable and a pivoted tone .arm; a screw driven in consonance with the turntable, a traversing amt connected to the tone arm for movement therewith as the tone arm moves from the rim of the t table towards the center thereof, a threaded element mounted on the traversing arm, the screw being pivotally mounted at its inner end for movement toward or from the threaded element, a spring 'urging said screw into engagement with the threaded element as the traversing arm moves, and manually operable means for shifting the screw-to- 1 ward or from the threaded element.

5. In a recording attachment for phonographs, the phonograph having a turntable and a pivoted tone arm, a screw extending radially of the driven therefrom, a traversing tone armmoves from the rim of the turntable towardsthe center thereof, an arcuate element pivotally mounted on the-extremity of the traversing arm for movement in a horizontal plane and having means on its convex edge face for threaded engagement-with the screw, a spring attached to the element andto the traversing arm and urging the element into engagement withithe screw, and manually operable means for retracting said elementfrom its engagement with the screw. 6. The combination with a phonograph in'q eluding a motorboard, a turntable above --the' arm having a portion thereof disposed abovegthe" 9,081,224 traversing arm being disposed between the turnscrew throughout the movement of the traversing arm,and manually operable means for disen-- gaging said element from the screw.

7. A recording attachment for a phonograph having a turntable and a pivoted tone arm having a portion disposed above the turntable; the recording attachment including a screw element driven in consonance with the turntable, a traversing arm connected to,the tone arm for movement therewith, a threaded elementmounted on the, traversing arm, the screw element and the threaded element being one shiftable toward or from the other in a plane parallel to the plane of the'turntable, a spring urging one of said elements toward the other element, and means for retracting one of said elements from the other element including a cam, a member engaged by said cam and connected to the shiftable element, and manually operable means for shifting the cam. 8. An attachment for phonographs,. havlnga motorboard, a turntable, a spindle therefor and a tone arm extending over the turn table, said attachment including a traversing arm attached at one .end to the tone arm to turn therewith as the tone arm moves from the rim of the turntable towards the center thereof, the traversing peratively' ersing arm as it moves from a point adjacent the to a point adjacent the of the turntable 9 In a radio-phonograph having an electric amplifier, a pick-up head adapted for use both in recording and reproducing, a turntable and a tone arm operating over the. turntable, of a,

to r

gaging said screw to cause the positive traverse of the tone arm across the turntable, an electric switch adapted to transfer the connection of the pick-up head from the input to the output board, a spindle for driving thetmntable. a tone 'of the amplifier when shifted in one direction and from the output to the inputof the amplifier when shifted in the other direction; and manually-operable means adapted to operate said elecarm pivotally connected to the tone arm ha tricswitch and simultaneously throw the trav- Jacent its pivotal'point and extending downward- 1-iersing arm and then radially between the turntable and-the means frictionally. holding the traversing arm in alinement with meme arm, means stopping the movement of the travers'ingj arm with the tone ,armwhen thetone arm has 1 1 beyond; the turntable, means acting'upons a removement of the tonefarnr to a position-Jo shiftjthe traversing li'acfF-iilto alineinentwiththe tone armland into frictional 1 engagement therewith, a screw disposed between driving engagement with the'spindle and extendingiadially thereof,'an element, carriedvby traversing arm and operativ'ely engaging said the turntable and the motorboat-d and having out of or into engagement withsaid- 'm a mechanism of the character described,

for acoustic or electric recording and reproducins-and having electric terminals, a traversing Y arm connected to the tonearm for movement therewith, a horizontally 'screwhaving operative driving engagement with the turntable, a threaded element shiftahlycarried by the arm for engagement with or disenga ment from said screw, manually actuated means forlshifta re e w ment with the screw, an electric amplifier having input and output terminals, a two-position change-over electrical switch having electrical connection with the terminals of said head and adapted to selectively couple said terminals with the input and output terminalsof the amplifier, and connecting means between said switch and said manually controlled means whereby the change-over of the switch from one position to another will be effected simultaneously with the movement of said threaded element relative to the screw.

11. In a recording attachment for phonographs having a turntable and a pivoted tone arm; a screw mounted horizontally beneath the turntable, means for rotating said screw in consonance with the turntable, a traversing arm con nected at one end with the tone arm and extending therefrom beneath the turntable, an arcuate threaded member mounted upon the end of said arm adjacent said screw and adapted for movement relative to the screw' in the horizontal plane occupied by the arm, resilient means normally urging said threaded element into engagement with the screw, and a cam actuated reciprocable element connected-with said threaded element for moving the same relative to the screw against the tension of said resilient means.

12. In a recording attachment for phonographs having a turntable and a pivoted tone arm; a screw rotatably mounted in a horizontal position beneath the turntable, means for rotating said screw in consonance with the turntable, a traversing arm attached at one end to said tone arm and extending therefrom horizontally beneath the turntable, a sleeve mounted for limited movement longitudinally upon the traversing arm at the end adjacent the screw, an arcuate threaded member carried by said sleeve for engagement with the screw, resilient means normally urging the sleeve in a direction to engage said element with the screw, a rod mounted for movement longitudinally of the arm and attached at one end to said sleeve, said rod having an upstanding portion at its other end, and manually actuated cam means supported by the traversing arm for contact with the upturned end of said rod to effect reciprocation of the same and movement of the threaded member relative to the screw.

13. The combination with a phonograph including a motorboard, a turntable above the board, a spindle for driving the turntable, a tone arm having a portion thereof disposed above the turntable and swingable to carry a sound box across the face of the turntable; of a traversing arm pivotally attached at one end to the tone arm adiacent the pivotal point of the latter and extending therefrom between the turntable and the motorboard, means frictionally holding the traversing arm in parallel relation with the tone arm, means stopping the movement of the traversing arm with the tone arm when the tone arm has moved in one direction beyond the turntable,

means acting upon a reverse movement of the tone arm to a starting position to shift the traversing arm back into parallel relation with the tone arm and into frictional engagement there with, a screw disposed horizontally between the turntable and the motorboard, means for rotating the screw in consonance with the turntable, an element carried by the traversing arm and operatively engaging said screw throughout the movement of the traversing arm with' the tone arm, and means for eflecting the relative movement of said screw and the element in operative engagement therewith.

,Aonnm DEMOCRATIS.

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