US2388964A - Phonograph recorder - Google Patents

Description

Nov. 13, 1945. 1.. B. GLASER ETAL PHONQGRAPH RECORDER Filed Jan. 1, 1943 2 Sheets-Sheet 1 Inveniaws Leo B. Glaser- I Roberi-G Ji'itornqy's 1945- L. B. GLASER EIAL 2,388,964

PHONOGRAPH RECORDER Filed Jan. l, 1943 2 Sheets-Sheet 2 E4 INVENTORS [1-- Y ATTORNEYS "Patented Nov. 13, 1945 PHONOGRAPH RECORDER Leo B. Glaser, Cranford, and Robert G. Franey,

Irvington, N. J., assignors to General Instrument Corporation, tion of New Jersey Elizabeth, N. J., a corpora- Application January 1, 1943, Serial No. 471,032

6 Claims.

This invention relates to an improved phonograph recorder.

The principal object of our present invention centers about the provision of a phonograph recorder constructed and designed to enable a greater flexibility and ease of operation as well as simpler combinability with reproducers or conversion to reproducing use when compared with prior and now standard phonograph recording instruments.

In the now standard type of phonograph recorder, the cutter arm (carrying the cutter head and stylus) is mounted for traversing movement of the cutter head and stylus across a record on the phonograph turntable; and for driving or feeding the cutter arm in the desired helical groove-cutting action of the stylus over the record, a rotating lead screw synchronized with the turntable drive is used with which detachably connects a screw-follower connected to the cutter arm. A number of operating limitations are inherent in this standard type of recording instrument. Due to the positive drive or feed and the detachable connection involved, initial placement and subsequent manual movement of the stylus on or over the record is not a simple operation, either for professional or amateur (home recording) use. Furthermore, such recording machines are ill adapted for use as or simple conversion to phonograph reproducing or playing machines. Many suggestions have been made to modify this standard equipment for simplification and for reproducer adaptation, such as the use of grooved plates or other devices fixed to a part of the turntable cooperating with tracker arms attached or attachable to the cutter am: but these all involve some specially designed apparatus or some special structural arrangement,

all limited, moreover, in operability by the use of positive driving or feeding of the cutter arm.

In the phonograph recorder of our present invention,the positive feed or drive for the cutter arm is eliminated, thus obviating the disadvantages and limitations which have been. inherent, in one form oranother, thereto. In the recorder of our invention, exceedingly simple frictional drive or feed mechanism is employed, such that the following action and advantages are obtained:

(a) Exact and predetermined helical grooves may be cut in the record without the use of a positive cutter arm feed or drive;

(b) The connection between the-cutter arm (the feed follower thereon) and the feed or drive mechanism is one involving a friction and fricbe embodied in a simple way in combined recording and reproducing machines, especially for home or amateur use. where constructional simplicity, low price and facility of operation and use are important factors; and

(d) The mechanism of our present invention is rendered especially usable for and with phonographs on which the turntable is rotated by a motor having driving connection with a part, such as the rim of the turntable.

To the accomplishment of the foregoing and such other objects as may hereinafter appear, our invention relates to the improved phonograph recorder and the mechanical combination structures involved therein as more particularly sought to be defined in the appended claims and described in the accompanying specification in connection with the appended drawings, in which: 7

Fig. 1 is a top plan view of the phonograph recorder of our present invention with parts broken away to better show certain features of construction thereof;

Fig. 2 is a view of the same taken in crosssection in the plane of the broken line 2-2 of Fig. 1;

Fig. 3 is a fragmentary view taken in crosssection in the plane of the line 33 of Fig. 1;

Fig. 4 is a fragmentary view on an enlarged scale taken in cross-section in the plane of the broken line 4-6 of Fig. l;

Fig. 5 is a view of a part thereof; and Fig. 6 is a view of Fig. 5 taken in cross-section in the plane of the broken line 6-6 thereof.

Referring now morein detail to the drawings, the phonograph recorder of our present invention comprises in its more generic aspects a turntable T for holding a record 1- to be groove-cut, a motor M for driving the turntable T, a cutter arm C with its cutter head It movably mounted for traversing movement of the cutter head It across the record 1- on said turntable, combined with a cutter arm feeding or driving mechanism generally designated as F constructed and designed to feed or drive the cutter arm C with a friction and friction-slip engagement. The feed or driving mechanism F is arranged to receive its motive power from the motor M which drives the turntable 1'. All of the parts of the phonograph recorder are suitably carried by a base plate B.

The turntable T may comprise an inverted dished member (see Fig. 2) provided with a central hub I which is removably received by the phonograph spindle H, which latter is fixedly bolted as at l2 to the centrally depressed portion l3 of the base plate B. The spindle H maybe provided with an integral disc part [4 which acts as a bearing for a ball bearing race ISengaged in turn by the hub it of the turntable. The hub ill may also be provided with a fixed internal sleeve l6 engaging raised parts of the. spindle H as best shown in Fig. 3 of the drawings. By means of this construction, the turntable T is made removably mountable on the fixed record receiving spindle and is provided with a suitable ball bearing mounting.

' table T which is driven from the motor M) and For driving the turntable T, the motor (electric motor) M attached in any suitable way to the underneath part of the baseplate and provided with the rotor wheel i1, is connected by a suitable friction drive to a part such as the rim (8 of the turntable T. This frictional connection may comprise a rubber or other faced wheel 19 mounted so as to resiliently engage the motor wheel l1 and the interior surface or wall of the turntable rim l3 (see particularly Figs. 5 and 6) To accomplish this, the rubber faced wheel 19 is rotatably mounted on a stud 20 fitted to one end of a lever 2| slidably fulcrumed at its other end by means of the base carried pin 22 and the lever formed slot 23, the said rubber faced wheel on the lever being urged against the motor wheel I! and the turntable rim i8 by means of a spring 24 anchored at 25 to the'base plate B and connected at 26 to the lever 2i. The said lever is guided limitedly in its movements and'is held spacially to the base plate by the stud and spacing washers generally shown at 21 (see Fig. 6). Operation of the motor M will thus rotate the turntable T; The turntable T is, nevertheless, disengageable from the base plate and the motor parts. When the removable turntable is mounted in position on the phonograph spindle, the rubber faced wheel I9 will be resiliently moved first into a position to permit the turntable to be properly mounted, after which the rubber faced wheel l8 will automatically move into the position shown particularly in Figs. 5 and 6 of the drawings for driving connection between the motor and the turntable rim.

The cutter arm C is mounted for the usual movements, that is, for the lifting and descending movement about a horizontal axis and for the record traversing movement about a vertical axis. To this end, the cutter arm C is hingedly mounted about the horizontal pivot 28 formed in a post 29, which post is rotatable about a vertical axis on a stud 30 fixed as at 3| to the base plate B. This cutter arm C carries at its forward end the cutter head It provided with the cutter pin or stylus 32 (see Fig. 2). In the desired operation, the cutter arm C is thus mounted for traversing movement of the cutter head It and its stylus 32 across the record 1' as the record is rotated, this to cut in the record the helical phonograph groove as is indicated in Fig. 1 of the drawings. cutter arm C in an inoperative position, there is --provided a finger piece 33 fixed to the carrier base B and adapted to receive the front arcuate part of the cutter arm C.

For holding the connected at its high power end, generally designated as 35, to a member m movable or rotatable with the cutter arm C. This construction is so devised that the member m and the high power end 35 of said reduction gearing are engageable with a friction driving engagement from gear and being secured to the base plate B in a manner hereinafter detailed. These wheels and pinions are arranged to mesh and to be driven in the manner clearly indicated, for example, in Fig. l of the drawings. the friction wheel 35 being arranged to engage the periphery of the turntable hub l0 so as'to be driven thereby. If a nonremovable turntable T be used, the connection between the hub in and the wheel 36 may be a positive one; the friction connection therebetween being provided because the turntable T as shown is removably mountable. By means of this construction, it will be seen that rotation of the turntable T by the motor M will set into motion the gear train R, the operation at the end wheel 36 of the gear train being with low power,

and the effect at the other end wheel 43 of the gear train being to transmit at this point a relatively low speed and. therefore, high power operation.

The member m comprises an arm fixed at its inner end 45 to the post 29 so as to rotate therewith, said arm being made arcuate shaped at its other end 48 and being preferably provided over this arc with a correspondingly arcuate shaped rubber or similarly resilient facing 41, which latter is adapted to frictionally engage the gear train end wheel 43 as most clearly shown in Fig. 1 of the drawings. The arcuate shaped arm end and facing 41 is only limited in length so that there is no engagement thereof with the end wheel 43 beyond the record traversing range of the cutter head, and so that these parts are engageable one with the other only over the record traversing range of the cutter head, this being most clearly indicated in Fig. 1 of the drawings. The arcuate shaped arm and the end or driven wheel are rotatable about parallel (vertical) axes, and are engageable, one with the other, with a radial thrust. To limit the inward movement of the cutter arm C, there is provided a stop member 48 fixed to the base plate B, the said stop member having an upstanding pin adapted to engage the arm of the member m when the cutter arm C reaches its most inward position, this relation being best seen in Figs. 1 and 4 of the drawings.

By means of this recited construction, it will now be seen how the various actions and advantages above referred to are obtained.

Exact and predetermined helical grooves may be cut in the record 1' without the use of a positive cutter arm feed or drive. The relatively high head h is caused to transverse in a very positive 5 manner over the record 1 and to accurately cut the helical shaped grooves in the record; The

action even with the use of afriction drive is so positive that grooves of very fine spacing such,

for example, as from 100 to 110 lines per inch, may be cut with this mechanism, thus adapting the same for both home recording or commercial usage.

From this construction it will be further noted that the connection between the member m (its arcuate facing Mland the feed or drive mechanism (the high power end wheel 63) is one involving a friction and friction-slip engagement. Thereby the cutter arm C may be freely moved about its horizontal or vertical axis outside of the record traversing range thereof without any engagement of the parts of the feed mechanism F taking place; and thus initial placement of the stylus on the record may be made without concerning oneself about the engagement between 2 the parts of this feed mechanism. Also it will be noted that as soon as the stylus is placed at its initial recording position on the record, the engagement between the end wheel 43 and the arcuate member 47 automatically takes place:

and thereafter the frictional engagement between these parts is such that the cutter head is caused to traverse the record to produce the helical grooves with the exactitude described. Also, it

will be noted that if it is desired to manually adjust or move the stylus on or over the record, this may be done merely by lifting the cutter C and placing the same on a desired part of the record, since the friction-slip engagement between the member 772 and the end wheel 83 of the gear train R readily permits'this to be done.

The cutter arm C when disengaged and not in use renders the recorder machine readily serviceable for or conversion to reproducing use, since at such time the follower member m' is disen-.

gaged from the gear train R. and this gear train does not offer any perceptible load to the operation of the turntable T when the turntable is now used for reproducing purposes. The recording machine of our present invention may, therefore,

be embodied in a combined recording and reproducing system especially for home or amateur use. The machine shown in the drawings is commercially embodied in such a combination,

the reproducing arm and the mechanism for.

In order to adjust for the desired frictional engagement between the and wheels of the gear train R. and its driving and driven parts, means is provided for adjusting the gears or wheels of the gear train. Such means may simply consist in mounting the studs 38, E! and M in enlarged orifices in the base plate B so that the studs may be adjusted in the base plate, the said studs being secured in adjusted position by means of securing nuts. Thus, enlarged orifices 69 are provided in 7 the base plate B for each of these studs, and the studs are secured in adjusted position by means of the nuts 50 which are threadedly connected to threaded termini of the studs.

The manner of making and using the phonograph recorder of our present invention and the many uses and advantages thereof will. in the main, be fully apparent from the above detailed description thereof. It will be further apparent that many changes may be made therein without departing from the spirit of the invention defined in the following claims.

We claim:

1. In a phonograph recorder comprising a support, a turntable removably mounted on said support, a cutter arm with its cutter head movably mounted on said support for traversing movement of the cutter head across a record held by said turntable, of mechanism for leading the cutter arm in its groove-cutting movement across said record, comprising reduction gearing mounted on said support and terminating at its low power end in a friction wheel and at its high power end in a friction wheel, the said removable turntable having a part removably engageable for driving engagement with said low power endfriction wheel, and a member connected to said cutter arm for rotatable movement therewith, the said member and the high power end friction wheel being engageable, one with the other, for frictional driving engagement from wheel to member over the record traversing range of said cutter head, the said member being disengageable from said high power end friction wheel when the cutter arm is manually moved beyond the traversing range of said cutter head to an inoperative position.

2. The phonograph recorder of claim 1, in which the cutter arm is rotatable on said support, and said member of limited length comprises an arcuate shaped member engageable as set forth in claim 1, disengageable from the high :power end wheel beyond the record traversing range of the cutter head, and automatically engageable therewith when the cutter arm is moved to ini-- tial recording position.

3. In the phonograph recorder of claim 1, means for adjusting the frictional engagement between the high power friction wheel and said cutter arm member comprising an adjustable mount for said high power friction wheel.

4. In the. .phonograph recorder of claim 1, means for adjusting the frictional engagement in the two friction driving parts thereof comprising an adjustable mount in said support for both the high and the low power end friction wheels.

5. In a phonograph recorder comprising a turntable for holding a record to be groove-cut, a motor for driving the turntable, a cutter arm with its cutter head movably mounted for traversing movement of the cutter head across a record on said turntable, of mechanism for leading the cutter arm in its groove-cutting movement across said record, comprising reduction gearing connected at its low power end to be driven by said motor and provided at its high power end with a driven wheel, and an arcuate shaped member of limited length connected to said cutter arm for rotatable movement therewith, the driven wheel and the arcuate shaped member being rotatable about parallel axes, the said arcuate shaped member and the said driven wheel being engageable, the one with the other, with a radial thrust for frictional and friction-slip driving engagement from wheel to arcuate member automatically engageable with said driven wheel when the cutter arm is moved from the inoperative position to initial recording position.

6. In a phonograph recorder comprising a turntable for holding a record to be groove-cut, a motor for driving the turntable, a cutter arm with its cutter head movably mounted tor traversing ter arm for rotatable movement therewith, the

driven wheel and the arcuate shaped member being rotatable about parallel axes, the said arcuate shaped member and the said driven wheel being engageable, the one with the other, with a radial thrust for frictional and friction-slip driving engagement from wheel to arcuate member over the record traversing range of said cutter head. the said member being disengageable from said driven wheel when the cutter arm is manually moved beyond the traversing range of said cutter head to an inoperative position and being automatically engageable with said driven wheel when the cutter arm is moved from the inoperative position to initial recording position.

LEO B. GLASER.

ROBERT G. FRANEY.

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