US2305680A - Phonograph - Google Patents

Description

C. W. DANN PHONOGRAPH Dec. 22, 1942.

Filed Dec. 14, 1940 4 Sheets-Sheet 1 I lll III.,

Cfzries WD@ m2 im?. o

Cttorneg 4 Sheets-Sheet 2 -un nl,

c. w. DANN PHoNoGRAPH Filed Dec'. 14, 1940 llillllllllllwullll Dec. 22, 1942.

Gttorneg 175 [l @n .rlmli Dec. 22, 1942. c. w. DANN I 2,305,680

PHONQGRAYH Filed Dec. 14, 1940 4 Sheecs-Sheetl 5 S- F20 1Z0 nventor i charles W. lamz B MMU M 4 Sheets-Sheet 4 mfencor` Charles WDaJUz Gttorneg Dec. 22, 1942.

u TEN m. B m5 www H I y GH .1 mw wm www Nw 4 n \.N ww mmv. mw Q@ WN `W%\I WlnmlI /f n IMF n hw@ 1 Il MSM m ma. il f 5| Ln.. -3. 'v @Aww l QN ll NWN. I I Inliom rhllm l ,NW ri l- ---l im@ QQ h l.. l u AIU. F I l l Il im SN la wlw mi .N2 wm EN mw Patented Dec. 2 2, 1942 UNITED STATES PATENT OFFICE PHONOGRAPH Charles W. Dann, East Orange, N. J., assigner to Thomas A. Edison, Incorporated, W

est Orange,

N. J., a corporation of New Jersey Application December 14, 1940, Serial No. 370,143

, 13 Claims.

This invention relates to phonographs and more particularly to commercial phonographs of the vbe attained in the recording and reproducing operations and that, in the attainment of any given standard of quality for the record as a whole. it causes an unnecessary reduction in the playing time of the record.

To overcome these undesirable results, phonographs have been constructed to operate at a constant linear groove speed. 'I'his is achieved by progressively varying the rotational speed of the record as the translating device traverses the same and, in turn, by progressively varying the travelling speed between the translating device and the record in accordance with the record rotational speed.

'I'he present invention is concerned with a constant linear groove speed type of phonograph wherein the varying speed of rotation of the record support or turntable is effected by means of a variable ratio friction drive, and wherein the varying speed of travel between the record and the translating device-the travel itself being in the present instance produced by holding the turntable axially stationary and moving the carriage for the translating device in translation vrelative thereto-is effected by a feed screw driven by the friction drive as for example from the turntable. I

Itis an object of my invention to provide a generally improved form of, and improvements in, a disk-record phonograph of the type here concerned.

A more particular object of my invention is to provide for a disk-record phonograph, a variable ratio friction drive of improved constructionand of improved operation and dependability; as a feature of my invention in this respect, the friction drive is arranged so that its drive transmission ratio is independent to an unusually high degree of wear or deformation of its friction driv- V ing element.

It is another object of my invention to provide improvements in the carriage feeding means which are adapted to insure a positive feed of the carriage at the instant the operation of the machine is resumed following a recoupling of the feeding means, whereby to insure a proper and sui'licient spacing between the convolutions of the groove formed on the record at such resumption of the machine operation.

Another object is to provide an improved and positively actuated means for effecting a complete and positive engagement of the feed nut and feed screw elements of the carriage feeding means each time these elements are brought into engaging relationship with one another.

It is another object to mount a control head of the machine for travelling movement independent of that of the carriage.

Another object is to provide a drive coupling between the control head and the carriage having a varying drive transmission ratio.

It is a further object of my invention to provide improved indexing means for disk-record phonographs.

It is another object to cause the travelling indexing element to move in predetermined relationship to the resultant movement between the record and the record engaging stylus; and, more particularly, it is an object to effect a travelling movement of the indexing element which is substantially in direct proportion to the rate and distance of travel of the record groove past the record engaging stylus. f

Another object is to cause a movement of the travelling indexing element which is amplied in relation to the travelling movement between the translating device and the record.

A further object ofmy invention is to provide,

in disk record phonographs, a drive coupling between the travelling indexing element and travelling carriage which has a transmission ratio varying in accordance with the degree of actuation of the coupling.

A yet further object is to drive the travelling indexing element through a variable ratio transmission actuated in accordance with the travelling movement between the translating device and record.. j

Other objects and features of my invention lie in the various details of construction and arrangement hereinafter described, and will more fully appear from the following description and the ap Figure 1 is a top plan view of a phonograph constructed in accordance with my invention, some portions being broken away forl the better illustration of the interior parts of the phonograph mechanism;

Figure 2 is a vertical sectional view taken substantially along the line 2-2 of Figure: 1;

Figure 3 is a partial, vertical sectional view taken through the machine substantially on the parts appearing in section substantially on the,

line 6-6 of Figure 1; and

Figure 'l is a fragmentary view taken from the front and illustrating in particular the structural details of a travelling carriage for certain control elements of the machine.

The phonograph herein shown has a frame assembly comprising a pair of left and right end plates I and 2 (see Figure 6) which are held together by four tie rods of which there are two upper ones 3 and 4, a bottom one 5 and an intermediate one 6 at the front of the machine, as shown for example in Figure 2. At the ends of v 2,305,680 is had to the accompanying drawings. of which:

is supported at approximately the same level as this cabinet wall; also, the edge of the opening 32 is shaped generally to conform with the edge of the plate. Thus, the plate and top cabinet wall form a substantially ternal parts of the machine.

The plate 28 forms with the top of the turntable a channel which is open along the right side of the machine. This channel is adapted to serve as a guideway for directing a record, which is to be mounted on the machine, into a substantially central position in relation to the turntable. A stopping of the record in the guideway in such positionfor example, a position just slightly beyond an exact central position in relation to the turntable-is determined by the abutment of the record against a stop 33 comprising a wall portion extending down from the edge 28a of the plate 28. To facilitate the entry of a record into the guideway a portion 34 along the top of the right wall of the cabinet case I3 is turned in at an upward angle to terminate just at the level of the turntable so as to form a ared mouth for the guideway, as shown in Fig. 6.

Cooperating with the record guiding means just described in the general way described and claimed in Dunning application Serial No. 362,990,

l led October 26, 1940, and entitled Phonographs the tie rods there are reduced-diameter portions which fit into respective holes in the end plates, and threaded axially into the ends of the rods are screws which clamp the end plates against shoulders on the rods formed bytheir reduced end portions; for example, on the right end portion of the rod 3 as shown in Figure 4, there is the reduced-diameter portion 3 tting into a hole 'I in the end plate 2 and there is the headed screw 8 threaded into the end of the rod and clamping the end plate securely against the shoulder 9 on the rod. This frame assembly is housed within a cabinet comprising a bottom plate I2 and a case I3 which fits down over the machine. The cabinet case is rectangular in shape as viewed from the top, and has its bottom plate I2 secured to the frame by screws I4 which thread through the plate into legs I5 projecting down from the end plates I and 2. A portion I3a of the front wall of the cabinet is inclined to the rear, along the length of the machine, as shown in Figures 1 and 2.

Supported by the tie rods 3 and 4 at the top of the machine in the right hand portion thereof is a table 20, as shown in Figures 3 and 4. This table is slotted as at 2| and 22, to fit the tie rods 3 and 4, but is held stationary on these rods by means of a set screw 23 which clamps the table to the back tie rod 4. 'I'he table serves as a support for a turntable 24 the spindle 25 of which is journalled in the table 20 and supported vertically'by a ball thrust bearing 26, as shown in Figure 5.

Overlying the turntable at a small distance thereabove is a ilat plate 28. This plate is supported by upward extensions 29 and 30 provided on the table 20 along the front and back thereof, and is held in place on these extensions by screws 3|. 'Ihe edge 28a of the plate along the left side thereof is circular and conforms with the edge of the turntable. This plate projects through an opening 32 in the'top wall I3b of the cabinet and f disk 42.

of the bracket 40. A raising of is a record centering and clamping device 35, as shown in Figures 1, 3 and 5. This device comprises an arm 36 which overlies the plate 28 in a direction extending radially of the turntable. The arm 36-which is preferably formed by die casting-has its rear end portion straddling a post 31 which projects up from the table 20, to which post the arm is pivoted by a pivot rod 38 which passes through ears 39 extending down from the side walls of the arm. Within the arm 36 in the front portion thereof, there is secured a double bracket 49 (see Figures 3 and 4) which is apertured to receive loosely a short spindle 4I having at its lower end a record clamping On the upper portion of the spindle Within the bracket 40, there is provided a stop collar 43 which serves to retainV the clamping disk to the arm 36 by its abutment against the bracket. On the upper end of the spindle there is provided a ball 44 which is adapted to bear against a ilat face 45 on the arm to form a thrust bearing for the spindle. Movement of the clamping disk onto the record, by the downward swinging of the arm 3B, is permitted by an opening 41 in the plate 28 through which the disk may pass.

As the arm 36 is swung down to place the clamping disk on the record a tapered pin 46, which is provided on the bottom of the clamping disk, passes through the central hole of the record and enters a central hole 48 in the turntable to withdraw the record from the stop 34 and to nely center the same in relation to the turntable. The arm 36 is biased down into operated position, to cause the clamping disk to bear against the record, by means of a flat spring 49 which at one end is held by a screw clamp 50 to the plate 28 and at the other end is extended slidably through an aperture 5I in the end wall the arm 3S into unoperated position to lift the disk 42 and pin 46 out of engagement with the record, and a latchlng of the arm in such unoperated position, is effected by means of a tilt lever 54 pivoted at 55 to the front end of the arm 36. As shown in Figure 3, when the lever 54 is tilted upwardly the inner end thereof will slidably bear upon the plate 28 to raise the arm, and just as the lever complete cover for the ln-..

is passed through a dead-center (i. e., vertical) position the downward biasing of the arm 36 will cause the lever to snap ahead into a limiting position determined by the abutment of the lever against an edge 56 on the arm 36. Thus, by a single manipulation of the lever the arm 3B may be both raised into unoperated position and then latched in this position.

It will be seen that the record guiding and clamping means just described renders the mounting of a record on the machine a very simpleoperation. For instance, it involves only inserting the record into the guideway and sliding it over the turntable until it abuts against the stop 34 and then tripping the lever 54 to release the latch on the arm 38. The removal of the record from the'machine is equally as simple as it involves only performing a single manipulation on the lever M, to raise and latch the arm Il in unoperated position, and then gripping the record at the mouth oi the guideway and sliding it oi! from the turntable.

Movably mounted on the tie rods 3 and I tol the left of the table is a carriage il having at its rearward end a slotted portion 8l which slidably nts the tie rod l and having at its forward end two spacedV bearings I2 and I3 which slidably embrace the tie 'rod I, as shown in Figures 2, 4 and 6. This carriage, like the table 2l, is provided at its front and back with upward extensions ll and I5 (see Figure 2) which project above the top wall Nb of the cabinet case through slot-like extensions t8 of the opening 31 in the top cabinet wall. Bridging the extensions Il and .l and connected thereto by screws l1 is a rectangular frame il, as shown in` Figure l. This frame serves as the support for a recording and reproducing translating means which by way of v example is illustrated as comprising separate recording and reproducing units l! and 1I. These two units are carried respectively in the front half and back half portions of the frame.

yThe units are pivoted at their far ends, for up and down freedom of movement in relation to a mounted record, by means of horizontally disposed cone pivots 1i which thread through the left and right sides of the frame into engagement with the frame structures of the units. In the 'the end plate i and by a standard 84 of the table 2li: the rod is biased longitudinally by a spring |81 against a ball thrust bearing B4' in the standard u. but is permitted to pivot about its longitudinal axis as is hereinafter explained. The feed screw 80. which is in the form of a threaded sleeve. slidably embraces a shaft 85 that is journalled in standards and 81 projecting down from the carriage 60. 'I'hese standards abut against the ends of the screw and thus hold the feed screw stationary against longitudinal movements in relation to the carriage. The feed screw is rotated by way of the shaft 85 to which it has a spline connection formed by a set screw 8l that threads through the feed screw into engagement with a slot ll provided in the shaft ll longitudinally thereof.

Driving torque of the feed screw is obtained from the turntable 24- through a drive transmission which comprises a pinion l2 on the turntable spindle II, a gear 8l in mesh with the pinion and having a vertical shaft $4 iournalled in the table 2l, a pair of bevel gears 85 connectin the shaft M to a horizontal shaft 8l Journalled in the standard I4 at a point axially in line with the shaft 8l, and a flexible shafting 91 interconnecting the shafts B5 and 96. The reason for using a shafting 91 of the flexible type is to case of the reproducing unit 10 the cone pivots 1i do not directly pivotally engage the unit itself but instead engage the en ds of a. block 12 which is connected by a vertical pivot 1l to a tail-piece 'Il on the unit 10. This vertical pivot is provided to aiford a lateral freedom of movement to the reproducing unit 10 in order to permit the unit to freely track the groove on the record.

The translating units 69 and 1I are herein only diagrammatically shown as they may be of any suitable type, and need not be described other than that they are respectively provided at their free end portions with recording and reproducing styli 69' and 1l" which project down below the units. When the translating units are lowered their respective styli pass through an opening 1.5 in the plate 28 into engagement with the record, the weight of the units themselves being relied upon to effect a proper coaction between the record and the styli.

A travelling movement of the carriage 6l along the rods 3 and I, to cause the translating units to traverse the record, is effected by means of a feed screw ll and cooperating feed nut 8l, as shown in Figure 6. The feed nut 8i is carried by a bail member l2 which is pivoted on a cross rod I3. This rod is supported at its ends by overcome the need for a critical aligning of the shafts Il and il.

The friction drive for the turntable-which is shown in Figures 2, 3, 4, 5 and B-comprises a drive cylinder or sleeve lill having end portions lOl of reduced bore which bear rotatably on a rod Il! extending centrally through the sleeve. The rod is supported -by the end plate i at its left end and by the table 2li at its other end, and is held in a position wherein the sleeve IM lies below the level of the turntable and in a direction extending radially thereof. This drive sleeve is rotated by a motor M which has belt connection Ill with a pulley IM on the sleeve at its left end. Driving torque from the sleeve |00 to the turntable 2l is transmitted by way of a friction wheel |05 interposed between the drive sleeve and the turntable and supported by the carriage Il. This wheel has a drive surface |05' suitably of a yieldable material such as rubber which frlctionally engages the drive sleeve at its bottom and the lower turntable face at its top, each at points substantially directly below the styli Il? and 1l' of the translating units. In the travellingI movement of the carriage 60 the fric- Y tion wheel is fed along the drive sleeve and radially along the face of the turntable. As the carriage is moved to the left-the friction wheel being then moved away from the center of the turntable-the rotational speed of the turntable is gradually decreased; the linear speed of the turntable past the friction wheel will however remain at a constant value; likewise, the movement of the record groove along the engaging stylus of the translating unit, since the latter is positioned directly above the friction wheel and carried therewith, will also beconstant and of the same value.

I'he friction wheel |05 as here employed comprises an intermediate coupling member of the friction drive. As so used, the wear on the drive surface of the wheel, and any deformations or fiats" which may develop thereon from leaving the friction'wheel pressed against its cooperating members during long periods of idleness of the machine, tend to be the same at both engaged ing to remain constant, the drive transmission, ratio through the friction wheel remains substantially constant throughout each turn of the wheel during the vperiod of its use.

In order that friction driving pressure of the drive sleeve against the friction wheel |05 may be relieved at will, to unclutch the friction drive, the rod |02 on which the drive sleeve is journalled is movably supported to permit a limited up and down freedom of movement of the drive sleeve. To provide this freedom of movement the left end of the rod |02 is pivotally supported by fitting the same loosely into the bore of a collar |08, pivoting the rod to the collar by means of a cross pin |09, and staking the collar to the end plate I, as shown in Figure 5. The right end of the rod |02 is then movably supported by journalling a ball head ||0 on the end of the rod into the horizontal arm Illia of a clutch lever and pivoting this lever, as at |12, to the left end wall of the table 20. (See Figures 3 and 5). This clutch lever is biased by a tension spring 3 (see Figure 3) so as to provide a normal driving pressure between the drive wheel and friction coupling. 'Ihis driving pressure may however be relieved, at will, merely `by rocking the clutch lever in a counterclockwise direction.

The friction wheel |05 is mounted on the carriage and provided with a vertical freedom of movement in order that it may equalize itself between the turntable and drive sleeve. 'I'he mounting for the friction wheel comprises a bracket ||5 which is screwed to the right end wall of the carriage and turned to the left over the carriage. Turned down from the sides of, the bracket are ears ||1 which project into rtf clearing slot ||8 provided in the carriage beneath the bracket. Pivoted to these ears on a pivot pin H9 is a. short rod |20 which extends horizonally along the slot ||8 and through an enlarged hole |2| in the end wall of the bracket, and journalled on the end portion of this rod beyond the bracket is the friction wheel |05.

It will be seen from the structure so far described that when the feed nut 8| is retained in engagement with the feed screw 80 and the clutch lever I Il is placed under the influence of its biasing spring ||3 to effect a normal driving pressure of the drive sleeve against the friction wheel and of the friction wheel against the turntable, then the driving torque from motor M will be applied to the turntable 24 and through the turntable to the feed screw 80 both to rotate the turntable and effect a leftward feed or travel of the carriage' 60 along the rods 3 and 4. This travel of the carriage causes the translating units to traverse the top of the turntable away from the center thereof, the friction wheel |05 similarly to traverse the bottom of the turntable, and the shaft 85 to move lengthwise through its bearings and through the feed screw 80. As the friction wheel engages the turntable at larger radial distances from the center of the turntable, the rotational speed of the turntable progressively decreases (whereby to maintain a constant linear speed of the record groove past the styli as hereinbefore explained) but so also decreases in the same degree the travelling speed of the carriage 60; thus, the styli of the translating units are moved relative to the record along a spiral line of constant pitch-i. e., of equal radial displacement between each convolution and the next.

The recording and reproducing translating units 69 and 10 are placeable into and out of operative conditionthe condition wherein their styli operatively engage the record-merely by lowering and raising the units onto and from the record. The conditioning of these units is effected by means of a slide |25 which is mounted on the left side of the frame 68 through pin and slot connections |26 (see Figures 1, 2 and 6).A

Provided on the top edge of the plate is a raised cam |21 having a central dwell |21a, and extending over the slide |25 from the free end portions of the translating units 69 and 10 are lift tabs |28 and |29 respectively. When the slide |25 is in a forward position the cam |21 is ahead of the lift tab |29 of the reproducing unit to render this unit free to engage the record in response to its own weight, but the dwell |21a of the cam is in contact with the lift tab-|28 of the recording unit to retain this unit in a raised or inoperative position; as the slide is moved rearwardly into a central position the tab |29 rides up onto the dwell of the cam and the tab |28 remains yet on this dwell to cause both yunits te be retained in inoperative position; and

as the slide is further moved into its rearward position the tab |28 rides oi from the cam to permit the recording unit to engage the record in response to its own weight but the tab |29 remains on the dwell of the cam to retain the reproducing unit in inoperative position. Obviously, when the slide is moved forwardly this sequence of events will be reversed.

The selective conditioning of the translating units and the engaging and disengaging both of l the carriage-feeding means and of the drive clutch, are all controlled concurrently by a single control lever |35. This lever projects through an opening |35 in the front of the cabinet case and extends across the inclined cabinet wall portion |3a, as shown in Figure 2. The lever is mounted for travelling movement along the front of the machine, and carried with this lever is an indexing device |36, hereinafter described, which with the control lever |35 forms a so-called control head for the machine. The mounting for this control head, which is shown in Figures 1, 3, 4 and '1, comprises a cross rod l0 supported at its ends by the end plates l and 2 and a bracketshaped member |31 having apertured left and right legs |31a and |31b which embrace the end portions of a sleeve |38 that slides freely upon the cross rod I0. The aperture in the left leg I 31a of the member |31 has a reduced bore to t a reduced diameter end portion |38a of the sleeve (see Fig. 7), and on the outer side of the right leg |31b of the member |31 there is screwed a plate |39 which bears against the end of the sleeve and holds the latter from longitudinal movement in relation to the member |31. The plate |39 is of an irregular contour, having an upward extension |39a serving as a support for the indexing device |36, as is hereinafter described, and further having a forward extension |3911 which straddles the front tie rod 6 to hold ythe bracket member |31 from turning on the rod Vlongitudinally thereof and extending the set screw |43 into engagement with this slot, the set screw being however slidable along the slot so as not to restrict the travelling movement of the control head along the rods and 3. 5

The separate elements controlled by the control lever |35 have a common coupling to the lever through the medium of the rod |0 and, because of this coupling function of the rod, the

same is splined to the control lever, as above de.. l0-

scribed. For the same reason, the rod is pivoted at its ends in the end plates and-2 through the provision of reduced diameter portions at the ends of the rod which are tted in holes in the end plates, there being, for example, the reduced l5 portion l0' at the right end of the rod which fits into the hole ||in the end plate 2 as shown in Figure 4. The means by which the rod is coupled to the slide to control the condition of the translating units 69 and 10, and to the lever 20 |41, to a plate |48 secured to the left end portion 30 of the rod I0. 'I'he coupling of the bail |44 to the slide |25, which is shown in Figure 2, comprises a rock lever |43 pivoted centrally thereof, as at |50, to the extension 65 of the carriage 60. The lower end of the rock lever straddles the bail at |5 I, and 35 is permitted to slide therealong in the travel of the carriage, while the upper end of the lever is pivoted at |52 to the slide |25. The coupling of the bail to the clutch lever which is shown in Figure 3, comprises a slide through screw and slot connections |54 on the left side of the table 20. At its rearward end the slide has a vertical slot |55 through which passes the bail |44, and at its forward end the slide has a downwardly extending V-shaped cam |55 which 45 cooperates with a similarly shaped but upwardly extending cam |56 on the arm |||a to control the clutch lever In considering the control functions of the control lever |35, as so far described, it will be seen that when the control lever is in a central or inoperative position-the position occupied by the lever in Figures 2 and 3--the slides |25` and |53 occupy their central positions and, as a result, the

translating units 63 and 10 are retained in their 55 inoperative positions and the drive sleeve |00 is retained in a lowered position to hold the drive clutch disengaged. However, when the control lever |35 is swung into an upward or reproducing position the slide |25 is moved forwardly to place 00 the reproducing unit 10 into operative position (while retaining the recording unit in inoperative position) and the slide |53 is moved rearwardly to free the cams and |56 from one drive clutch in response to the action of the spring H3; and when the control lever is swung into a downward or recording position the slides |25 and |53 are moved in the reverse directions from the foregoing to place the recording unit into engagement with the record (while retaining the reproducing unit in inoperative position) and again to permit the spring I3 to engage the drive clutch. In order that the respective positions of the control lever may be clearly defined there is |53 mounted 40 -pivoted on a stud 2|0. carried by the plate |39, a

detent 2| I which is biased by a tension spring 2 2 into engagement with a notched extension 2 I3 on the hub of the control lever, as shown in Figures 3 and '1.

The action of the control lever |35 on the car-g riage feeding means is such as to place the feed nut 3| out of engagement with the feed screw 30 when the lever ls in inoperative position and into engagement with the feed screw when the lever is in either its recording or reproducing positions. 'I'he means by which this is accomplished comprises an upward cam extension |60 on the plate |48 and a cooperating pin |6| on an arm |62 of the bracket 82. When the control lever is in inoperative position the tip of the cam extension a engages the pin |6| to hold the bracket in a counter-clockwise direction (as it appears in Figure 2) and the feed nut out of engagement with the feed screw; but when the control lever is swung into either recording or reproducing positions the cam extension moves free from the pin, in either one direction or the other, and the bracket 82 is then swung in a clockwise direction on the rod 33 by a tension spring |63 connected between the arm |62 and a pin on the end plate It is highly important to a proper operation of the phonograph-particularly in the course of recording-that the threads` of the feed nut and feed screw come into positive and complete engagement/each time the control lever |35 is manipulated to place the machine into recording condition. If it fails to do this a slack is left between the threads of the nut and screw, of some length up to the spacing between successive convolutions of the thread, and the initial period of operation following the manipulation of the control lever will be consumed in taking up this slack without incurring any actual feeding of the carriage; this loss in carriage feed causes they groove convolutions formed on the record by the recording stylus to be crowded together and even to overrun one another. To insure against such possible crowding or overrunning of the groove convolutions, through an incomplete engagement of the threads of the feed nut and feed screw, I provide means by which a positive advance of the feed nut along the feed screw, through approximately the distance of spacing between succeeding thread convolutions, is eected each time the machine is shifted from neutral to recording condition. This feed-nut advance means is actuated positively by the manipulation of the control lever |35 into recording position, but the actuation is timed to occur only as a terminal result of this manipulation in order that the advance of the nut will not take place before it has engaged the screw.

'I'his feed nut advance means is shown in Figures 2 and 6 and comprises the following principal elements: Anarm |65 pinned to the rod 33 between the legs of the feed-nut supporting bracket 32; a cam face |65 on the left side of the hub of the arm |65; a cross pin |66 on the another and thus permit an engagement of the 65 left leg of the bracket 32 which engages the cam face |65'; and the aforementioned compression spring |61 which is mounted on the rod 83 between the end plate and the bracket 82 and which biases the bracket to the right along the rod 33 into a position determined by the abutment of the pin |66 against the cam face |65'. As the control lever |35 is swung down into recording position, the cam face |63 on plate |48 impinges against the pin |63 to rock the arm |65 in a clockwise direction. As the rod is so rocked the bracket 82, by the action of cam face |65' against pin |68, is pushed a short distance along rod 88 towards plate against the pressure of the spring |61. The feed nut is thus moved positively to the left as a terminal result of each placement of the control lever |35 into recording position. When the control lever is returned to inoperative position the arm |65 is returned to unoperated position by a tension spring |10 and the feed nut advance means is thus conditioned for re operation by the action of spring |61.

In order that the record rotation may be stopped at will without disturbing any other adjustment of the machine-for example, to give the operator time to determine the course of his thoughts during a dictation recording operation-there is provided an independent mechanism for actuating the drive clutch. This actuating mechanism, which is herein diagrammatically shown (see Figure 3) and referred 'to as |1I, may be of any suitable type-for example, an electromagnetic device such as that disclosed in Langley Patent No. 1,380,486, issued June '1, 1921, and entitled Controlling device." A device of this type has an electromagnetically actuatable armature |12 from which the power to operate the drive clutch is taken by way of a link |13 pivoted to thearmature as at |12'. The far end of this link has a pin and slot, or lost motion, connection |14 with a downwardly extending arm ||b of the clutch lever this connection |14 is made of the lost-motion type in order that the clutch lever |I| may be operated by the control lever |35 to control the drive clutch as heretofore described without producing any actuationof the mechanism In the inclined front wall portion |3a of the cabinet case, along the greater part of the length of the case, there is provided a rectangular opening |15, which is a downward continuation of the aforementioned opening |35 through which extends the control lever |35; and supported in the plane of the inclined wall portion I3a in the opening |15 is a holder |16 for an index slip, as is shown in Figures 1, 2 and 3. 'Ihis holder is of the usual type, comprising a ilat plate |16a having its top and bottom edges |16b turned over to form a channel through which an index; slip |11, made for example of paper, may be inserted from the right end of the holder and be retained therein. The support for this holder comprises a bracket |18 secured by screws |19 to the rod 6 and secured as by welding to the holder |18.

Marks or annotations of an explanatory character as with respect to selected portions oi' recorded matter are made by the indexing device |33 herelnbeiore referred to. 'Ihis indexing device is herein illustrated, purely by'way of example, as of the type disclosed in Gramman Patent No. 2,184,914, issued December 26, 1939, and entitled Phonograph, and to which reference may be had -for a description of the same in all its details. This type oi.' indexing device forms the annotations by perforating or punching the index slip. These perforations are effected by means of keys of which in the present instance there are two referred to as |80 and |8| and designated respectively by the letters L and C, the key marked L being for purposes of denoting length of individual sequences of recorded matter and the key marked C being for the purpose of denoting points where corrections have been made in the recorded matter. 'I'hese keys are carried by the upper one of a pair oi' jaws |82 and |83 which project forwardly from the aforemembers secured to the keys. In line with each key, in the bottom of the index holder and along the length thereof, is a slot |86, and associated with the keys are springs (not shown) which resiliently hold the keys in raised positions. As the keys are depressed the members |85 punch through the slip and pass through the slots |88 in the bottom of the holder to enter the holes |84 in the lower jaw |83. The punchings from the slips are collected by a trough |81 formed below the Jaw |83 from an extension of the bracket |18.

In the usual phonograph arrangement the indexing device is mounted directly on the carriage of the machine to partake oi its movement across the index slip holder, or o1' the travelling movement of the translating device across the record. In a disk-record phonograph the travelling movement oi' the translating device is small and in a uniform groove speed type of disk-record phonograph the amount of recorded matter on the record which is represented by a given radial displacement of the device in its path varies continuously throughout the movement of the device. It is thus desirable in this type of phonograph that the movement of the indexing device be to an amplied scale in relation to the travelling movement between the translating device and the record and also that it be so proportioned in relation to the movement between the record and engaging stylus that a given displacement of the indexing device from any point in its path will represent a fixed amount of recorded area on the record. To achieve these objectives the indexing device is provided with a movable mounting which is independent from that of the carriage-the indexing device being slldably mounted on the rods 6 and I0 with the control lever |35 as hereinbetore describedand is connected to the carriage through a drive coupling having an amplified and varying movement-transmitting ratio. The varying transmitting ratio oi this drivecoupling is controlled so that the rate of travelling movement of the indexing device is maintained at all times substantially in direct proportion to the linear speed of the resultant movement between the record and the translating umts; or, expressed in other words, the drive coupling is arranged to eiect a displacement of the indexing device along the index slip holder which is in direct proportion to the length of record groove traversed by the engaging stylus.

To effect a movement of the indexing device .in the manner just described there is provided a gear rack |00 on a frame |9|l which is secured by screws |92 to the top of the end plate the frame being thus held in a horizontal plane at a small distance belowthe top of the machine, as shown in Figures 1, 2 and 6. Journalled in the carriage 80, as at |93, (see Figure 4) is a pinion |94 which meshes with the rack |90 and which carries a grooved pulley |95 having a portion of its periphery in a form of a spiral. At the tip |95' of the drive pulley |95 (see Figure l) there is fastened, by a clamping screw |96, one end oi a exible cord |81 which is wrapped about the drive pulley in a clockwise direction to the most rightward point of the pulley. From this point the cord runs oi from the drive pulley in a forward direction, forms a loop along the front.

right and back sides of the machine and then returns tothe drive pulley at the same point at which it left the pulley. This loop of the cord is directed by a series of rollers around which the cord passes, there being for this purpose two pairs of rollers |99 and |99 pivoted on the frame Ill at its front and back respectively, and two rollers 290 and 29| pivoted on the table 29 at the front and back right hand corners of the machine. The return end portion of the cord is wrapped about the drive pulley |95 nearly to the point of fastening of the start end of the cord. and is there secured to the drive pulley by an anchor nut 202, which nut serves also as a means for tightening the cord to the desired degree of tautness. This cord is connected to the movable control head of the machine by a screw clamp 293 which clamps the cord tightly to a bracket 204 provided on the upward extension |39a of the plate |39, as shown in Figures 2, 3 and 4.

'I'he pitch of the pulley |95--i. e., the change in radius per unit angular change-is the prime factor determining the transmission ratio ofthe drive coupling between the control head and the carriage 60 and may be ascertained from the iollowing mathematical considerations:

If we write for the rotational speed of the turntable 24 and r for the driving radius oi the turntable, or distance from the center of the turntable to the friction coupling wheel |95 (the distance also of the center of the turntable to the engaging styli) then,

( l) r0=1c, a constant, for a constant linear speed of the record groove past the stylus If we let d stand for the rate oi travel of the carriage, then (2) d=k10 where k1 is another constant determined by the drive connection 'between the turntable and the carriage feed Substituting Eq. 1 in Eq. 2 (3) d=krk/r If we let 0p stand for the rate of turning of the drive pulley |95, then (4) 0p=knd where kn is a constant depending upon the radius of the pinion |94 Substituting the value of d of Eq. 3 into Eq. 4 (5) =kak1klr If we let rp stand for the radius of the drive pulley |95 at its point of drive (i. e., at the point where the cord runs oi from the pulley) and t stand for the rate of travel of the cord, then (6) t=6pa And substituting Eq. 5 in Eq. 6 (7) t=kk1krrp/r From Eq. 'l it is clear that the rate of travel of the cord, and thus also of the control head or indexing device across the index slip holder, may be ampliiled in relation to the carriage travel according to the value chosen for the drive constant k2; and that it will be constant in value -the same as the rate of travel of the record groove past the stylusso long as the radius rp at the drive point of the pulley |95 is maintained ata ilxed ratio in relation to the driving radius r of the turntable. It is on the basis of fulnlling this ilxed proportionality between r and rp that the pitch of the drive pulley is determined.

according to the degree of its actuation.

If the proportionality between the drive radius rp of the spiral pulley and the drive radius r of the turntable 24 is made unity in value, then the change in radius at the point where the cord leaves the spiral pulley is exactly equal to the distance of travel of the carriage. Thus when the spiral pulley is mounted on the carriage, as has been heretofore described, the change 'in radius at the drive point of the pulley is exactly compensated by the carriage traveland, as a result, the drive Ipoint on the pulley remains fixed or stationary in relation to the frame of the machine; this is a highly desirable result as it permits the driving movement to be taken from and transmitted to the drive pulley |95 without error or mechanical difllculty.

Although I have herein shown and described my invention in terms of a particular embodiment it will be understood that this embodiment is illustrative but not limitative of my invention as the same is subject to many changes and modifications without departure from the scope of my invention, which I endeavor to express according to the following claims. v

I claim:

l. In a phonograph including a rotatable support for a disk record, a record cooperating translating device and means to eiiect a relative travelling movement between said device and said support: the combination of an indexing means for the phonograph comprising two parts arranged for relative travelling movement; and a movement transmission operatively connecting said indexing means with said movement-elicoting means and having a varying movementtransmitting -ratio causing the rate oftravelling movement between said two indexing parts to vary in relation to that of the travelling movement betweensaid support and translating device.

2. In a phonograph including a rotatable sup` port for a disk record, a record-cooperating translating device and means to eiiect a relative travelling movement between said device and said support: the combination oi indexing means for theV phonograph having a movable indexing element; and a drive connection between said movement-electim means and said indexing element including means causing the movementtransmitting ratio of the drive connection to vary progressively in predetermined relation to the distance of travel between said translating device and said support.

3. In a phonograph having a record supporting device and a translating device, one of said devices being mounted for travelling movement in relation to the other: the combination of an indexing means for the phonograph comprising a movable indexing element; and movement-transmitting means between said element and said one device having a movement-transmitting ratio of difierent magnitude at diilerent relative positionings between the translating device and record supporting device.

4. In a phonograph having a record supporting device, a translating device and means mounting one of said devices for travelling movement in relation to the other: thecombinatior. of an indexing means having an element arranged for travelling movement; and a movement transmission between said indexing element and said one movable device including means actuated by said one movable device in accordance with the travel of the same for varying the movement-transmitting ratio of said transmission.

5. In a phonograph having a record supporting device, a translating device, and means mounting one of said devices for travelling movement in relation to the other: the combination of an indexing means having an element arranged for travelling movement; and a movement transmission between said indexing element and said one movable device including means to cause a varying amplied movement of said indexing element in relation to the movement of the said one movable device.

6. In a disk-record phonograph having a turntable and a translating device, one of said two mentioned elements being mounted for travelling movement whereby to permit a traverse of the translating device in relation to the turntable substantially along a radial line of the latter: the combination of an indexing means for the phonograph having a part arranged for travelling movement; and a drive coupling between said part and the movable one of said rst two mentioned elements including a variable ratio movement-transmitting means actuated by said one movable element in the travel of the same to cause the movement-transmitting ratio of said drive coupling to vary in direct proportion to the radial displacement of said translating device from the center of said turntable. x

'7. In a phonograph comprising a turntable, a translating device, and drive means for rotating said turntable and concurrently e'ecting a travelling movement between the turntable and said device whereby to cause a resultant movement of constant velocity between the turntable and translating device: the combination of indexing means for the phonograph having an indexing element arranged for travelling movement; and a variable ratio movement-transmitting means actuated by said drive means and controlled in predetermined relation to the travelling displacement between said device and said support, :for causing a travelling movement of said indexing element at a rate bearing a ilxed proportional relationship to the velocity of the resultant movement between the turntable and translating device.

8. In a phonograph having a record support `and a translating device, one of said two elements being mounted for travelling movement in relation to the other: the combination of indexing means for the phonograph having an element arranged for travelling movement; a spiral member rotated by said one movable element in response to the travelling movement of the same; 'and means transmitting to said indexing elementv the movement of the periphery of said spiral member past a xed radial line thereof.

.9. In a phonograph having a record support ing means for the phonograph having an element arranged for travelling movement; a pivotal spiral member carried with said one movable element; means causing a pivotal movement of said spiral member at a rate proportional to that of the travelling movement of the same, the pitch of said spiral member being such that the radius of the spiral member in the line of its travel varies in direct proportion to the distance of travel of the member whereby to cause the pespiral member at said line to remain stationary in relation thereto; and means for imparting to said indexing element the transverse movement of the periphery of said spiral member past said line of travel.

10. In a, phonograph having a record supporting device, a translating device and means mounting one of said devices for travelling movement relative to the other: the combination of a control head for the phonograph; means mounting said control head for travelling movement relative to that of the movable one of said devices; and variable ratio movement-transmitting means coupling saidone movable device with said control head for causing a travelling movement of one in predetermined relationship to that of the other.

11. lin a phonograph having a record supporting device, a record-cooperating translating device, one of said devices being mounted for travelling movement relative to the other: the combination of means associated with said device for adjusting the same into operative and inoperative conditions in relation to a supported record; a manipulatable control member for said adjusting means Ioperatively connected thereto and mounted to travel independently of the movable one of said devices; and movement-transmitting means coupling the movable one of said devices with said manipulatable member for causing a travelling movement of one in response to a travelling movement of the other.

12. In a phonograph including a record-supporting device, a translating device and means for eil'ecting a relative travelling movement between said devices: the combination of an indexing means having an element arranged for travelling movement; and a movement transmission between said movement-eiecting means and said element having a movement-transmitting ratio greater than unity and varying in predetermined relation to the relative displacements between said translating and record-supporting devices.

13. In a phonograph including a supporting device for a. disk record and a translating device, one of said devices being mounted for travelling movement whereby to produce a traversing movement of the translating device relative to the face of a supported record: the combination of indexing means including a movable indexing element; and means, actuated to a degree varying in accordance with the amount of displacement between said devices, for causing said indexing element to be displaced in varying amplied relation to the said displacement between the devices.

CHARLES W. DANN.

Images