US2506665A - Releasable tone arm locking means - Google Patents

Description

J. L. GIOVANNUCCI RELEASEABLE TONE ARM LOCKING MEANS May 9, 1950 3 Sheets-Sheet 1 Filed Nov. 18, 1944 IN V EN TOR. (70 4/2/61. 670u4/v/v0cc/ y ,1950 J. L. GIOVANNUCCI 2,506,665

RELEASEABLE TONE ARM LOCKING MEANS 3 Sheets-Sheet 2 Filed Nov. 18, 1944 Y Y I r Li I :i I I l i 9% k M/ W A j? 52' 2 492m l Y 32 w zz x 3 7 I H I Z6 e; 1 a v U F i 15 a1 1y ||w IIIW" 39 456 4;? INVENTOR.

' Jz7uwL67aw/v/vac0/ May-9, 1950 J. L. GIOVANNUCCI 2,506,665

I RELEASEABLE TONE ARM LOCKING MEANS Filed Nov. 18, 1944 v s Sheets-Sheet 3 /l 11 ym 115 1/ 11d 111 12 T 3o- HHIHI l I l l IHIIHIIIIW I INVENTOR. 17005 L; 5/0w4/v/vu00/ Patented May 9, 1950 UNITED. STATES PATENT OFFICE RELEASABLE TONE ARM LOGKIN G MEAN S Julius L. Giovannuoci; North Haven, Conn., assignor to The Soundscriber Corporation, New Haven, Conn, a. corporation of Connecticut- Apnlication November 18, 194.4,, SerialNo. 564 054 1 This invention relates to sound recording and reproducing, and more particularly to an apparatus which is especially adapted for use. as a dictating machine.

One. object istoprovide. a machine of the above, nature having recording and playback heads,

oth of which have, forwardly-extending handles to facilitate the raising; and the lowering of said heads from the disk record upon. which they are supported; and also to permit said heads to be easily swunglaterall-y across said record.

ltnother object is to provide anapparatus oi A further object is to. provide an apparatus of the above nature in which mechanism is fur.- ni'shed whereby the operation of depressing the handle of. the recording head clamping cam'will automatically preset the control lever to full speed position.

A still further object is to provide an appara-tus of'the above nature inwhi'ch the. recordinghead clamping cam hasa bell crank handle connected with a downwardly inclined strap for operating the recording-maybe. ck selector switch, and also having means. to preset the turntable control lever.

A furtherobject is to-providean apparatus of the above nature in which provision is made of a. variable resistor coupled mechanically to the speed control lever and arranged in the input circuit of the amplifier in such a manner that a constant output volume will be maintained dur ingplayback. regardless of the, speed of the turntable.

A further object is to provide an apparatus of above nature. which. means. are. provided tor adjusting; the. maximum. playback speed at whichtheoontrol lever maybe presets A further object is to provide an apparatus-of. the above nature which will be. relatively Simple in canstructi-on,v irreimens'rveto manufacture. easy to install and manipulatapcompact. and vet-v efficient and durable in user with. these and other objects. inqvievr, there has-been illustrated on the accompanying draw-- lngs, one form in which the invention may-cons;

veniently be embodied in practice.

In the drawings:

Fig. 1' represents a perspective View of the.-dl'c.-v tating' machine as it appears when both the cording and playback heads are: clamped in raised:v

position above the. disk record.

Fig. 2 is a. fragmentary plan view of the right hand front corner of the same. with the top 05? the cabinet removed.

Fig- 3' is a perspective schematic-view showin thespeed control and volume control mechanisms:

and also the mechanism operativelyconnected with the recording head clamping cam. for re: storing the, control lever to the full speed, posie tion. when the recording; head, is lowered upon the record.

Fig. 4 is a, detailed sectional view of the sup porting bracket for the speed; control lever and volume control mechanism and associated parts. Fig-L 5 is a circuit diagram of a portion of. the apparatus.

Fig. 6 is afront view of the upper portion of the apparatus showing; the recording head clam-p! ing cam in lowered position, and the playback.

head clamping cam in raised position.

Fig. '2 is a. perspective; View of the record-ins head clampin cam.

Fig. 8 is a side view of the recording head and the swinging arm upon which it is supported.

Fig. 9 is a side view of the playback head. and. its swinging arm. Referring now to the drawings in which like referencev numerals denote corresponding parts throughout the several views, the numeral H) in.-; dicates a U-shaped head-supporting -bridge which is. secured tothe opposite sides of-a chassis plate- 35 located in, the upper part of a cabinet Qbr: means of two pairs of screws llla, Illa.

Mounted: upon the bridge I i1 is a- U-shaped clamping cam H for holding a recording head RH in raised position above a record R. Asian i'l'ar: U-shaped clamping cam l-la is furnished; for holding the playback head PBH inraisedposi tion. The depending arms of the cams It, and

tluvare. pivoted on, a common horizontal central. pin Ho and; a pairoiouter horizontal p1ns;,l;l.c lid, respectively. which pins are mounted central. dependin lu He. and, the outer pot.- tions of said bridge: I, respectively; The r c rd. ing head clamping; cam l t has abellicrank handle that its right hand endprovided, with a down wardly. ofiset. horizontal rear leg t3. which: nee-ted: bya downwardly inolmed strap, L4 and; shoulder screws [5, 1.6- to a: selector switch lovers;

3 block l8, said strap l4 passing through a slot 36 in the chassis plate.

The strap [4 has a slot I! at its lower end for loosely embracing the screw I6 which extends from the side of the selector switch block l8, the latter also having a rearwardly-extending horizontal shaft l9 connected with a selector switch (not shown).. The playbackhead cam Ila is also provided with a forwardly-extending handle l2a (see Figs. 1 and 6).

In order to restore the turntable to normal full speed whenever the recording head RH is lowered upon the record, provision is made of an inclined laterally-extending stud 28 connected to the intermediate portion of the strap I4, said stud being adapted to engage a rearwardly inclined upwardly-extending link 2| which isadjustably secured by means of a pair of screws 22, 23 to a channel-shaped bracket 25. The screw 22 serves as a pivot for the link 2|, while the screw 23 is located in an arcuate slot 24 formed at the lower end of the adjustable link 2 I Below the bracket 25 provision is also made of a horizontal plate 26 which is connected by a screw 21 to the bracket 25 and forms a bearing for a stud shaft 28 which projects downwardly therethrough. As will be seen in Fig. 3, the bracket 25 is so disposed as to support the link 2| in laterally offset relationship to the axis of the stud shaft 28.

' The stud shaft 28 is surrounded at its upper portion by a vertical bushing 29 which is journaled in a flat block 30 underlying the plate 26. The block 30 is attached rigidly, by means not shown, to a horizontal mounting plate 3|.

In order to adjust the speed of the turntable T during playback, provision is made of an L-' shaped lever 32, the upper vertical end 33 of which passes through an arcuate slot 34 in the forward part of the chassis plate 35. The lever 32 is secured at the rear end to the top of the bracket 25.

The speed of the motor is controlled by a swinging magnet assembly 31 which is secured to the stud shaft 28 by means of a pair of horizontal setscrews 38, 39, said magnet assembly be ng held upon said shaft 28 by an elastic fiber'stop nut 40 located on the lower end thereof. The magnet assembly 31 has an air gap 4| which is adapted to embrace a magnetic brake disk '42 which is fastened to a turntable motor shaft 43 by means of a set screw as. a

It will be understood that by shifting the vertical end 33 of the speed control lever 32 within its slot 34-, the magnet assembly 3i will be moved in an are around the stud shaft 28 so that the air gap 4| will be either partially over, completely over, or outside the perimeter of the non-magnetic brake disk 42. By means of this construction'the magnetic flux which passes through the gap 4| will be varied to increase or decrease the speed of the turntable T mounted on the motor shaft 43 in accordance with the area of the disk 42' which is actually embraced by said gap.

The volumeof the playback'wlll be automatically maintained at a uniform level by means of a; movable resistor arm 45 located in a circular casing 45cc and mounted ona depending threa'd ed shaft 46 which is located within an angle bracket 41 secured to said shaft 46 by a pair of nuts 48, 49 situated above and below said bracket 41 respectively. The shaft 46 has an unthreaded reduced lower section 55 secured as by a set screw to a collar member 52 resting upon the adaptor plate 26. The vertical leg of the angle bracket 41 is secured to the bushing block 38 by means of a pair of horizontal screws 53, 54.

The arm 45 is mounted to swing over an arouate resistance 45a connected at its ends to wires 45b, 450 leading to the output of a preamplifier P. The wire 45b and the arm 45 are connected to the input of a main amplifier A. By means of this construction it will be seen that as the speed control lever 32 is swung about the stud shaft 28 to reduce the speed of the turntable T during playback the volume of the amplifier A will be increased automatically by the resistor arm 45.

The recording and playback heads RH and PBH are pivotally mounted upon recording and playback arms 55 and 55, respectively, and have pivoted lifting handles 51, 58, respectively, on their forward ends. The handles 51, 58 have resilient and depending curved rear ends 59, 68 which'are adapted to slidably engage the heads RH and PBH respectively.

Operation When the cam handle I2 is swung upwardly,

the U-shaped cam I I will clamp the lifting handle 51 against the bridge Ill so that the recording head RH will be held and locked in raised position. Similarly, when the handle in is moved upwardly, the playback head PBI-I will be clamped in raised position.

It will be understood that the operation of lifting the handle l2 will swing the selector switch block 13 about its shaft is and place the apparatus in condition for playback. When the han-' dle I 2 is lowered again, the selector switch will be reversed to place the apparatus in condition cording head is in raised position, the speed control lever 32 may be moved backwardly to cause the turntable to rotate at any lower playback speed without releasing the recording head clamping cam handle 12 from its raised position.

In case it is desired to adjust the position ofthe strap M to control the maximum turntable speed at which the apparatus may be preset, this,

may be accomplished by loosening the screws 22, 23 and swinging the link 2| to the desired angular setting after which the screws will again be tightened.

One advantage of the present invention is that both the recording head and the reproducing head of the dictating machine may selectively be moved to and held in any desired position upon the record R merely by manipulating the handles 51, 58 and I2, l2a and without,

touching the recording or playback heads themselves in any manner.

Another advantage of the present invention is that playback speeds as low as 2 /512,. P. may be employed satisfactorily for playing back high speed code signals.

A further advantage is that the swinging of the U-shaped smooth-surfaced clamping cams will in no way injure the recording or playback heads or their handles.

While there has been disclosed in this specification one form in which this invention maybe 5 embodied, it is to be understood that this form is shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosure but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new and for which it is desired to secure Letters Patent, is:

1. In a dictating apparatus, a phonograph chassis, a record-carrying turntable mounted in said chassis, a stylus-carrying head mounted to swing across said record, said head having a forward manipulating handle arm, a fixed horizontal bridge located above said arm, a clamping cam located below said arm and being pivotally mounted in said bridge, and means for swinging said cam upwardly into engagement with said arm to detachably lock said arm against said bridge in raised position above said record.

2. In a dictating apparatus, a phonograph chassis, a record-supporting turntable mounted in said chassis, a stylus-carrying head mounted to swing over said record, said head having a manipulating handle extending forwardly therefrom, a U-shaped bridge on said chassis and embracing said handle, a U-shaped clamping cam pivotally mounted in said bridge beneath said handle, said clamping cam having a handle to permit said cam to be swung upwardly into engagament with said head handle to detachably lock said head in raised position above said record and hold it from swinging movement.

3. In a dictating apparatus, a phonograph chassis, a record-supporting turntable and a driving motor therefor mounted in said chassis, a recording head mounted to swing over said turntable, a forwardly-extending manipulating handle on said head, a bridge of inverted U-shape secured to said chassis and embracing said handle, a pivoted horizontal manually opera ble cam for raising and clamping said handle against said bridge, manually operable means for adjusting the speed of said motor during a playback operation, and mechanism connected to said cam for automatically setting said adjusting means at a predetermined point when said cam is moved to lower said recording head handle, whereby the turntable will rotate at a predetermined speed during every recording operation.

4. An apparatus as defined in claim 3, in which provision is made of a playback device, means for maintaining the playback volume at a uniform level regardless of the speed of said turntable, and means connecting said volume maintaining means for operation by said motor speed adjusting means.

5. An apparatus as defined in claim 3, in which said speed adjusting means includes a pivotally mounted magnetic brake for said motor, and setting mechanism comprising an inclined strap connected at its upper end to the recording head clamping cam, and means on an intermediate portion of said strap for engaging said speed adjusting means to reset said turntable to full speed when said cam is moved to released position.

JULIUS L. GIOVANNUCCI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,295,712 Brown Sept. 15, 1942 2,300,239 Thiede Oct. 27, 1942 2,326,625 Di Toro Aug. 10, 1943 2,359,370 La Forest Oct. 3, 1944 2,359,489 Proctor et a1 Oct. 3, 1944

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