US1550345A - Gramophone - Google Patents

Description

' A F. R. COTTON GRAMOFHONE Filed June 11, 1923 5 Sheets-Sheet 1 Aug. 18, 1925- Q 5 1,550,345 A. F. R. COTTON GRAMOPHONE F i led June 11, 1923 S'Sheets-Sheet 2 GRAMOPHONE 3 Sheet s-Sheet Filed June 11", 1923 shown as an' intermediate lever t fths r ae The carriage z is provided with a small pinion or milled wheel i (Figure 6) engaging with a correspondingly toothed or milled face of the bar a, this pinion being revoluble by means of a knob i for the purpose of shifting the carriage i along the bar, and a spring 2' acts as a. brake to hold the carriage in the set position.

Beneath the carriage i and at the level of the rim of the turn-table j, there is mounted a rubber-tyred wheel or rollerZi adapted to engage the turn-table when the travel of the tone-arm brings it into contact therewith, the point of engagement which initiates the resetting action being variable according to the position of the slidable carriage. The wheel is preferably eccentric, so that when it first engages the rim of the turn-table, the pressure between'them increases automatically to ensure firm contact, even if the rim of the turn-table should not be truly circular. This wheel 76 (see Figure 8) is pivoted or revoluble upon a stud 7c and provided with two upstanding pins Z which limit its movement by their abutment againsteither side of a web i on the carriage, and also with a radially Outstanding crank arm 70 which (as seen in Figure is adapted to advance a movable member which is here pivoted to and dependent from theweb i at i. This lever i is of inverted lQ-shape and it is weighted at its upper vpart so that its dependent leg' will normally hang vertically from its pivot close to the periphery of the wheel Z3. This leg of the lever i is adapted to be struck by a projection Z upon the revolving turn-table when the lever 2' has been advanced into the path of the projection by the action of the crank arm Z. This projection Z in its rotation with the turn-table, passes under the wheel 70 (as seen in Figure 4:) but when the crank arm Z0 has been swung round by the rotation of the friction roller is, it interposes the intermediate lever i in the path of the projection Z, so that at its next revolution the projection from the turn-table will strike the movable memberor lever The displaceable bar 6 will therefore be rocked to the position of Figure 5, in which it is held by the detent h, the soundbox being at the same time raised by the cam The impact of the blow also causes the tone-arm to swing back towards the starting point, or-if desired a spring a or weight may be employed in the known manner for effecting the return movement of the tone-arm;

It is to be noted that in Figure 2 the soundbox has moved transversely across the record disc, as compared with Figure 1, the pm 7c in Flgure 2 contacting with the web Z so that the roller '70 remains stationary its crank arm 7a holding the lever 71 in the The wheel 70 is put out of balance, for example, by providing a number of holes it, so that as soon as the arm i escapes from the projection Z, the wheel returns to its original orientation, its axis being at that time oblique owing to the rocking of the bar 6. The weighted lever also resets itself and assists in restoring the wheel Z5.

An adjustable stop m, consisting of a spring plunger adapted to slide in a. cylindrical guide m upon a supporting bracket m and normally secured at any desired position by a clamping lever m in the form of a bell crank with very unequal arms, controlled by a spring m is arranged upon the top board of the instrument in line with the arcuate movement of the detent h; for setting the point at which the repetition is to commence, the needle is placed upon the record disc at the. desired position, and the spring plunger then allowed to project until it engages the tail h of the detent, the plunger being automatically looked as soon as the lever m is released. v

hen the return of the tone arm brings the detent 72 it into contact withthe stopplunger m the catch 0 is released; the bar (2 then resumes its normal position, allowing the soundbox c to descend upon the record. The descent is preferably retarded by means of a cam or eccentric quadrant f? of the known kind, pivoted upon the wedge or cam f, so that when the bare allows the needle to descend, the quadrant f trails upon the revolving record and lowers the needle gently into position. a h It will be noted that the longitudinal bar a is weighted by the wheel 7:, knob 71 and other parts, so that is resumes its normal position as soon as the detent h releases the catch 6 The design of the arm supported from the tone-arm may be varied; for example it may be inclined or curved at an angle of approximately 4C5 degrees, so that instead of receiving a direct blow it is moved gradually by the pawl or projection.

Figure 8 represents a modified construction of the friction wheel 7U','in which the latter is provided with a dependent pin is which forms the movable member, being adapted to be brought into the path of the projection Z (as shown in dotted lines) when the wheel is rotated by its frictional engagement with the turn-table.

The project-ion Z is shown in Figures 1, 2, a and 8, as a small roller mounted upon a stud or pin outstanding from the rim of the turn-table. In Figure 9 I have represented an alternative form, in which a pawl Z is pivoted on a pin Z and controlled by a spring Z as soon as this pawl Z engages the arm it is brought against the stop pin Z", its free end being simultaneously moved outwardly away from .theperiphery of the dotte di'lines the roiii which. lever o 1 ,ful-

crumed at of upon theo ii struinentha s at one end a bralie' shoe o ladapted. to engage the turn-table j, and at t e otherend a pad t-rup e. rliiqli th gneedle Q T.;. QU. ld can rest, the weight of the soundbox then acting to press the brake shoe into contact with the turn-table, against the c t-ion of a spring 0*.

Having thus described what I claim is 1. In a gramophone, a turn-table, a travelling tone-arm, a soundbox arranged at one end of said tone-arm, a pivotal support for the tone-arm so that the soundbox can travel across a record disc located on the turn-table, means carried by the tone-arm for lifting the soundbox, means dependent from the travelling tone-arm for preliminarily engaging the revolving turn-table, a pivoted device carried by said tone-arm, said device as a result of such preliminary engagement being moved into position to be operated by the turn-table, and means carried by the turn-table for engaging said pivoted device, said pivoted device thereupon operating said lifting means. In a gramophone, a rotatable turntable, a projection from said turn-table, a travelling tone-arm having at one end a pivotal bearing and at the other end a soundboX, a displacea-ble bar carried by said tonearm, means carried by the bar for engaging and lifting the soundbox as a result of a movement imparted to said displaceable bar, a movable member carried by the said bar and adapted to impart movement thereto, and means whereby said movable member is engaged and operated by the projeetion from the turntable 3. In a gramophone, a roitatable turntable, a projection from said turntable, a travelling tonearm fitted with a soundbox, a pivotal mounting for said tone-arm whereby the soundb-ox, can travel transversely of the record, bearings upon said tone-arm, a displaceable bar carried in said bearings, means carried by the bar for engaging and lifting the sound-box and a movable member also carried by the tone-arm and adapted to be actuated by the projection from the turn-table, said bar-displacing means being operated by the actuation of the said movable member oarried by the tone-arm.

my invention,

t. In a gramophone, arotatable turn table,

a projection from said turn-table, sleeveltonearni having a soundbox at one end ibeiigg' pivotally mounted at the other end, ad1 splaceable bar carried by itlietonearm vvitlioiie end adj acentto'the souiidbox, means providedupon that end of the, bar fori engaging and lifting'the soundb'oX, a lev r controlling the displacement of said a frictionwheel, carried by thetonearm. and adapted to be brought into'operative contaetqvith the revolving turn-table during the travel of i the tone-arm, and means I provided upon said friction wheel forbring- 4 mg said lever into the path ofsaidprojec .tion to actuate ureaisp'nceabn bar. j j 5. In a ramophdn of theit ype having a rotatable turntable and a tone-arm swinging so that its soundbox can travel transversely across the record disc, a resetting mechanism comprising a movable member carried by said tone-arm, a projection on the rim of said turn-table, a displacea-ble bar travelling with said so-undbox and adapted to lift its needle from the record, said movable member actuating'said displaceable bar, means for bringing said movable member into the path of said projection, and means forreturning the tone-arm towards the starting point.

6. In a gra-moph'one of the type having a rotatable turntable and a tone-arm swinging so that its soundbox can travel transversely across the record disc, a resetting mechanism comprising a movable member carried by said tone-arm, a projectionon the rim of said turntable, a displaceable bar travelling with said soundbox, means carried by said displaceable bar for lifting the needle from the record, said movable member actuating said displaceable bar, means for bringirw said movable member into the path of said projection, and means for restoring said displaceable bar to its original position at the starting point.

7. In a graanophone, the combination of a tone-arm swinging transversely across a record disc, a displaceable bar rockable in bearings beneath said tone-arm, means carried by said bar for raising the soundbox, a carriage adjustable along said bar, a friction wheel revolubly mounted on said carriage, said whee-l adapted to engage the turntable towards the end of the record, a movable member controlled by said friction wheel and adapted to be engaged by a projection on the turntable, the engagement of said movable member by said projection causing the displacement of said bar and the liiitiing of the soundbox, and means for restoring said bar to its original position at the starting point.

8. In a gramophone resetting mechanism, the combination of a turntable, a projection on said turntable, a displaceable bar adapted to engage the sound box and lift the needle from the record, means for displacing said bar, said means actuated by a blow delivered by the said projection when the resetting is to take place, a detent for retaining said bar in its displaced position during the return movement of the soundbox, a stop for releasing said detent on arrival at the restarting point, and a spring plunger automatically adjusting said stop when released with the needle at the desired starting position.

9. In agramophone resetting mechanism, the combination of a turntable, a projection on said turntable, a rock-able bar, a cam at one end of said bar, said cam adapted to engage the soundbox and lift the needle from the record, means for rocking said bar, said means actuated by a blow delivered by the said projection when resetting is to take place, a catch secured upon said bar at the opposite end to said cam, a detent co-operating with said catch to retain said bar in either of two positions corresponding respectively to the raising and to the lowering of the needle, a stop for releasing said dotent on arrival at the restarting point, and means for automatically adjusting said stop when the needle is placed at the desired starting position.

In testimony whereof I have hereunto affixed my signature.

ARTHUR FREDERICK RICHMOND COTTON.

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