US1626088A - Apparatus for sound reproductions - Google Patents

Description

April 26, 1927. 6;088

J. J. JAKOSKY APPARATUS FOR SOUND REPRODUCTIONS Filed April 15. 1926 3 Sheets-Sheet l 5 fig/ YwzziW p ATTOR EY A ril 192 p 7 .1. J. JAKQSKY APPARATUS FOR SOUND REPRODUCTIONS 3 Sheets-Sheet 2 Filed April 15. 1926 I EEP I I I da/w 38 A I ii J. J. JAKOSKY APPARATUS FOR- SOUND REPRODUCTIONS April 26, 1927. 1,626,088

Filed April 15. 1926 5 Sheets-Sheet 3 A TT ORNE Y Patented Apr. 26, 1927.

PATENT OFFICE.

JOHN J. JAKOSKY, OF IIOS'ANGELES, CALIFORNIA, ASSIGNOR' T INTERNATIONAL PRECIPITATION COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA.

APPARATUS FOR SOUND RE PRODUCTIONS.

Application filed April 15,

This invention relates to the electrical reproduction of sound from phonograph records andthe main object of the invention is to provide an advantageous type of transmitting or reproducing device having means adapted to hold a phonograph needle in position to engage the record and means for producing electrical impulses corresponding in frequency and intensity to the vibrating motion imparted to said needle by the undulations in the phonograph record. In the making of phonograph records the cutting medium which engraves the undulations in the record corresponding to the sound to be recorded may be caused to vibrate in a certain direction, for example horizontally and transverse to the grooves in the record, and in reproducing the sound ,from such record it is necessary that the needle of the reproducer be permitted to vibrate in the same direction as the needle or-stylus used in recording and that the .reproducing device be adapted and connected for actuation by said needle so as to transmit electrical impulses corresponding to the vibration in this direction. It is possible during reproduction, however, that due to roughness or irregularity in the phonograph record the point of the needle may be moved or vibrated in other directions than that in which the principal vibration takes place. If such vibrations of the needle in other directions are permitted to cause production of electrical impulses in the transmitting device the quality of the reproduction is impaired since the electrical impulses so produced cause sounds other 1 than those desired, and a considerable partof the scratching sound ordinarily heard in phonograph reproduction is or may be due to vibrations of the needle in directions other than that corresponding to the direction of the major or intended vibrations. For example, in a phonograph record in which the undulations corresponding to the sound to be reproduced occur in a horizontal direction transverse to the grooves of the record, the scratching sound, may be due vibration or" the needle vertically or to vibration of the needle longitudinally of the groove. important object of my invention is to provide a reproducing device of such construction that any vibration ims 1926. Serial No. 102,100.

set up electrical impulses in the transmitter or reproducer, While vibrations of such needle in any other direction will be either mechanically prevented, suppressed, or damped, or Will be prevented from actuating the transmitting device to cause production ofelcctrical impulses. In such manner the sounds recorded on the record are reproduced with the utmost clearness and accuracy, while foreign sounds due to mechanical scratching of the needle on the phonograph record or irregularities therein are entirely suppressed or reduced to a minimum.

The provision of a transmitter or reproducer which is sensitive or responsive to vibrations in one direction only as above described constitutes an important object of my invention. The reproducer which I may use for this purpose comprises preferably a rocking member mounted to rock only in one plane or "about one effective axis or fulcrum and provided with means for carrying a phonograph needle or stylus in position to engage the impressions of a phonograph record, the direction of the axis about which said member is mounted to rock being such that said member is permitted to rock in response to motion of said needle in the direction of the sound undulations in the record; means for resiliently resisting such rocking movement so as to damp the same andtend to hold the rocking member in a certain equilibrium position; means for Wholly or substantially preventing rocking motion of said rocking memberin any other directionv or about any other axis than that desired and for also Wholly or substantially preventing translative motion of said rocking member; electromagnetic means; movahly mounted armature means associated therewith; and link means connecting the rocking member to the armature means so as to transmit the motion of said rocking member only in the desired direction to the armature means. Not only is the motion of the rocking member in any other direction than that desired subst-anitally prevented, but also the link member is so connected to the rocking member with respect to the points or places of support of said rocking member that with respect to motion of said rocking member in the desired direction theconnection thereof to the link member is at an appreciable distance from the efi'ective fulcrum or axis of the rocking member so as to provide an appreciable efi'ective lever arm for transmittingmotion in this direction to the link mfin ber, while with respect to the motion of said rocking member in another direction in which it is desired to suppress vibrations, the connection of the link mem her to the rocking member is in line with or substantially in line with the effective fulcrum or axis of said rocking member so as to provide no lever arm or substantially no lever arm for transmitting rocking motion in this direction to the link member. F urthermore the link member is somewhat flexible but is sufiiciently rigid to transmit motion in a. lengthwise direction and is so connected to the rocking member and to the armature that the motion of the rocking member which it is desired to transmit to the armature acts along the length of the link member so that such motion is effectively transmitted to the armature means. The flexibility of the link member however renders it incapable of effectively transmitting to the armature means any motion of the rocking member in any other direction. The entire device is therefore highly selective with respect to the direction of motion which is transmitted from the phonograph needle to the armature means.

A further object of my invention is to provide a transmitting device which is aperiodic, that is to say, which has no natural period or frequency of vibration, at which it tends to oscillate or vibrate with greatly increased intensity, producing what may be termed blasting sounds. This is a defect which is found in diaphragms, and hence in the ordinary mechanically reproducing phonograph or in any system in which the needle actuated mechanism comprises a diaphragm or other element having a natural period of vibration. This 'object I accomplish by making the rocking member itself of the transmitting device substantially rigid, and mounting the same on aperiodic resilient supporting and damping means as hereinafter described.

The accompanying drawings illustrate embodiments of my intention and referring thereto:

Fig. 1 is a vertical section of a cabinet provided with means for electrical reproduction of phonograph records according to my invention.

Fig. 2 is a plan view of the apparatus shown in Fig. 1, with the cover of the cabinet removed.

3 is a section on line 33 in Fig. 2.

Fig. 4 is a section on line 44 in Fig. 3.

Fig. 8 is an inverted horizontal section on line 8-8 in Fig. 6.

Fig. 9 is a diagrammatic representation of an electrical amplifying system suitable for use in connection with my invention. 7

Fig. 10 is a plan view of a device which I may use for making the electrical connection between the transmitting device and the amplifying system shown'in Fig.9.

Fig. 11 is a section on line 1111 in Fig. 10.

Fig. 12 is a plan view with the cabinet cover removed showing the 'method of mounting the transmitting device on the tone arm of a mechanically reproducing phonograph.

Fig. 13 is a partly sectional plan view showing in more detail the method of mounting the transmitting device on the phonographtone arm.

Fig. 14 is a side elevation of the parts shown in Fig. 13.

F ig 15 is an inverted horizontal section similar to Fig. 8, showing a modified means of mounting the rocking member.

Fig. 16 is a section on line 16-16 in Fig. 15.

Referring to Figs. 1 to 3 the apparatus therein shown comprises a cabinet 1 provided with horizontal partitions 2, and-3, and hinged cover 4 serving to provide upper, middle, and lower compartments 5, 6, and 7 within said cabinet. Within the upper compartment 5 there may be provided a rotatably mounted record carrying plate or disk 8 whose vertical shaft 9 extends through partition 3 and is connected to driving motor indicated at 10 within the middle compartment 6. Said driving motor 10 may be either a spring motor or an electric 1no-' tor of any suitable type ordinarily used in phonographs and may be provided with the usual devices not shown for stopping and starting, for controlling the speed thereof, for winding (in the case of a spring motor), etc. The lower compartment 7 may be used for any suitable purpose. for example itmay be provided with a hinged door '11 at the front end thereof and may be used for storing phonograph records in the usual manner. The cabinet, record-carrying plate, driving motor, ete., above described may constitute parts of an ordinary phonograph provided with means for mechanical production of sound, in which case the usual tone arm may be simply swung to one side or removed when my device is applied thereto for electrical reproduction; or the above parts may be provided solely for use in connection with my invention, in which case 29 when the transmitting device is there is no need for provision of the usual tone arm and built-in horn.

A substantially horizontal carrying arm 14 may be mounted at a suitable point in the upper compartment of the phonograph so that it is adapted to swing freely in a horizontal arc across and above the grooves of the phonograph record. For this purpose said arm may be provided with upper and lower bearings 15 and 16 engaging vertical shaft or rod 17 and may also hear on face plate 18 at the upper end of post 19 which extends upwardly from a base member 20 mounted in any suitable manner on horizontal partition 3. Arm 14 may be cut away as indicated at 21 so as to'permit it to swing horizontally without striking the vertical post 19.

The transmitting or reproducing device indicated at 28 may comprise a cylindrical casing 29 within which are mounted the parts hereinafter described and said device may be provided with a pair of projecting lugs 30 and may be pivotally mounted by means of said Lugs at the outer end of arm 14 so as to swing in a vertical plane. For this purpose a pin 31 may extend through said lugs and through a similar pair of lugs 32 at the end of arm 14. I prefer to provide means for decreasing the efi'ective weight of the transmiting device on the phonogra h needle; for example arm 14 may be provi ed with an interior recess and a counterweight arm'24-may also be mounted on pin 31 between the lugs and independently of the reproducing device and may extend within recess 25. Pin 31 therefore serves as a common pivot means for the transmitting or reproducing device and for the counterweight 24. Said counterweight arm may be provided with'a shoulder 27- adapted to be engaged by the casing lowered intoposition on the phonograph record. By this means the transmitting device may be raised ofi of the phonograph record and tilted back as indicated at 28 for'insertion of a new needle, etc., during which movement said device swings free from the counterweight arm 24 which simply falls to a position of rest at the bottom of. recess 25. hen, however, the transmitting device is lowered into playing position the rear face thereof engages shoulder 27 so as to lift the counterweight arm from its position of rest and the counterweight arm then serves to reduce the effective weight of the transmitting device upon the needle or st lus. The counterweight arm 24 may be ma e of such weight as to exert the desired counterplate and secured thereto, I provide apert ment of the balancing effect and give any desired prcs from the bri manent magnet 36 formed for example as a'ring' extending around inside of the casing 29 and having its two oppositely charged ends 37 and 38 overlapping but spaced from one another. U-shaped pole pieces 39 and 41 may be secured to the respective ends 37 and 38 of said magnet and an armature42 may be mounted for rocking motion between said pole pieces. Said armature may be mounted for example by means of flexible wires 43 and a light wire spring 44 may be so mounted as to exert a downward pressure on one end of said armature so as to preserve a slight tension on the suspension wires 43.

Beneath the supporting late 34 is'mounted a substantially rigid rocl ing member comprising for examplea bridge or plate 46 and a needle-carrying member 47 integrally or rigidly secured to said bridge. The ends of the bridge 46 may be mounted between aperiodic resilient supporting pads or blocks 48 consistin for example of cylindrical pieces of rub er or other yielding or resilientbut substantially aperiodic material and said bridge may be clamped between said pads by means of suitable clamping means such as bolts 49 extending through said plate 34 and through said pads and also passing loosely through openings 51 in bridge 46, said bolts being provided at their lower ends with washers 52 and nuts 53. Said nuts may be tightened to any desired extent so as to cause the bridge '46 to be held-with the desired firmness between the resilient supporting pads or blocks 48 and thus provide the desired damping effect, while permitting slight rocking movement thereof. The needle carrying member 47 may be provided with a suitably shaped recess 56 adapted to receive a phonograph needle or stylus 57 and a set screw 58 may be rovided for securing said needle within sai recess. A link member 59 may be secured .at its ends to armature member 42 and bridge member 46, for example by soldering or otherwise, so as to transmit rocking motion of bridge 46 to armature 42 as hereinafter described. In order to permit lengthwise adjustment of the link member with respect to the rocking member, 1

said rocking member may be formed or novided with a bent-over portion 61 exten ing back beneath and somewhat beyond the bridge 46 member may bent over portion. Said bent over be secured to the end of said portion has a certain amount of resiliency, and an adjusting screw 62 passes through an-openand the lower end of said link ing therein and screws into the main portion of the bridgz, so as to. provide for adjustnt over portion toward or away e. The effective length of the link member tween the armature and the rocking member may thus be adjusted as desired so as to properly space the armature between the pole-pieces 39 8.!!(1 41. l,

A wire coil 63 may be provided around the armature member 42 in such manner that changes in themagnetic flux in said armature member, due to rocking motion thereof between the pole pieces 39 and 41, causes electric currents or impulses to be set up within said coil.

A cover plate 64 may be provided for protecting the rocking member and other parts above described, said cover plate together with supporting plate 34 being secured to the ,casing 29 in any suitable manner. Said -er plate may have an opening 65 through ich the needle-carrying member 47 proje cts and through which access may also be had to adjusting screw 62.

Any suitable electrical amplifying means may be used for amplifying and transmitting the electrical impulses set up in the above described transmitting device. Such amplifying means may comprise thermionic vacuum tubes 66 and 67 each provided with filament 68, grid 69, and plate 71, and may further comprise transformer 72 having its primary winding connected to the plate of electrically o 4 able point within or convenient v,reception of. radio messages, --comprising for 7 electrical impulses 50 ing the volume of I means and the usual A, B, and Cvbatteries for supplying the necessary electric current or voltage thereto. The amplifying system above described may be a separate amplifying system and may be located at any suitto the phonograph or it may comprise the audiofrequency amplifying system of a radio receiving set. The coil 63 of the transmittin device may be connected by wires 76 and 7 v t0 the filament and grid respectively of thermlonlc tube 66 and a rheostat or variable re- -A sistance means 78 may be included in one of said wires for varying the strength of the therein-and hence adjustsound production.

When the amplifying means constitutes part of a radio receiving set the connections may be made, as above described and as shown in fulllines in Fig. 9, to the first audie-frequency amplifying 'tube; or if desired the connections may be made, as indicated in dotted lines at. 76 and '77, to the detector tube 79 of said radio receiving set. It will be understood that such radio receiving set may be provided with the usual means for example antenna 81, groundvconnecti'on 82, primary and secondary coils 83 and 84,.variable condenser and grid leak and cond er .86. The-a s e ay e comprise transformer 87 having its primary winding connected to the plate of the detector tube 79 and its secondary winding connected to the grid of the first amplifier tube 66, and the usual A and B battery connections may be provided. \Vhen the transmitting device is connected to the grid circuit of the detector tube in this manner the detector tube is utilized as an additional amplifying tube, thus giving an additional stage of amplification. It is to be noted that when the transmitting device is so connected, the connection 77 is made between the grid of the detector tube and the grid leak and condenser 86 so that the grid leak and the condenser serve to prevent the passage back into the receiving circuit of practically all of the audio-frequency current from the transmitting device and hence ensure said current being confined to the grid circuit of tube 79.

The wires 76 and 77 for connecting the transmitting device to the amplifying means may advantageously pass, as shown, through an opening 89 in the side wall of the casing 29 of said transmitting device and may then I pass through an opening 91 into the recess 25 within arm 14 and may be carried back within said recess to the base ofsaid arm. The rheostat 78 may be located within base member 20 and the operating stem of said rheostat may constitute the vertical rod or shaft 17 about which arm 14: swings, said shaft passing through said arm and being provided with a button 79 for effecting ad'- justment of the rheostat. The wires 76 and 77, may pass throu h an opening 81 in the base of arm 14 and through opening 82 in base member 3 and the rheostat may be connected to one of said wires so that the resistance thereof is inserted in 'said wire. The wires 76 and 77 may then pass through openings 83 and 84 in the cabinet and may be provided at their ends with suitable means for connection to the amplifying system. 11 advantageous type of connecting means which I have devised for this purpose is shown in Figs. 10 and 11. The connecting member 86 therein shown may comprise a plug portion 87 adapted to fit within a thermionic tube socket indicated in dotted lines at 104, and a socket portion 88 adapted to receive the base ofa thermionic tube indicated in dotted lines at 105. The plug portion of'said connecting member may be provided with four contact pins 91, 92, 93, and 94 which are ada ted to engage the usual contact elements of a thermionic tube socket, and the socket portion of such connecting member may be rovided with four contact members 95, 96, 9 and 98, which are adepted to engage the usual ins o'rlugs at the base of a thermionic tu andwhich are connected by wires99, 100, 101,1md 102 to the respe tive contact pins 91 93, and

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' other direction than that above described 94. The wires 76 and 77 may extend through an opening 103 in the side of the connecting member 86 and may be connected respectively to contact members 97 and 96 which are adapted to be engaged respectively by the negative filament and grid contacts of the thermionic tube. Socket 88 may be provided with a slot 106 adapted to receive the usual projecting pin or lug 108 of a thermionic tube soas to provide a bayonet joint means between the tube and'the socket, while plug 87 may be provided with a pin 107 adapted to engage slot 109 in the tube socket for Lafs'imilar purpose. In order to connect the transmitting device to the thermionic tube of a radio set or other amplifying system by means of the connecting member above described, it is only necessary to remove from its socket the tube to which the connection is to be made, and insert in such socket the plug portion 87 of said connecting member and then insert the tube in the socket portion 88. Such tube is then connected in the circuit in exactly the same manner as before and the necessary connections of wires 76 and 77 are also provided.

In the operation of the above described apparatus a phonograph record indicated at 111 is placed on the record-carrying plate 8 and is set in rotation at the proper speed by operation of motor 10 in the usual manner.

The reproducing or transmitting device 28 is then lowered onto the record so as to cause needle or stylus 57 to traverse the groove of the record. The undulations in the groove of the record, which for use with the particular reproducing device shown extend transversely with respect to the groove, cause the point of the needle to move rapidly back and forth in such direction and such motion of the needle causes rocking motion of the bridge 46 about a horizontal axis perpendicular to. the direction of cut of'the undulations in the record, such axis -being indicated at 00-09 in Figs. 6 and 8. Such motion is then transmitted through link member 59 to armature 42. Said armature is thus caused to vibrate or rock about its midline.

It will be noted that the resilient supporting pads 48 tend to hold the bridge 46 in a certain normal position and resiliently damp the rocking movement of said bridge about its effective axis m-w. Because of the aperiodicity or damping effect of the supportin pads the rocking member has -no' natura period of vibration and hence no tendency to oscillate at frequencies corresponding to sounds of certain pitches.

Furthermore the resilient supporting pads serve to substantially prevent rocking movement of the rocking member in any and also substantially prevent translative vibration of said rocking member.

In the vibration of armature 42 the respective ends thereof are brought alternate- .ly closer to and further away from the respective pole pieces 39 and 41 so that an alternating magnetic flux is set up within said armature. Small alternating or variable electrical impulses, corresponding in frequency and intensity to the vibration of well-known and forms no essential feature,

of this invention. The operation of such amplifying. system is such however as to produce within the loud speaker or sound producing means 73 alternating current impulses corresponding to but of much greater intensity than the electrical impulses initially set up in coil 63, and such amplified electrical impulses are utilized in the usual manner for the operation of a diaphragm or other vibrating sound producing member so as to produce sound of much greater volume and better quality than can be produced by the ordinary phonograph diaphragm which is mechanically actuated by the needle.

Because of the elimination of oscillation or blasting in the reproducing or transmitting device, there is no blasting in the sound produced, and all notes or pitches are reproduced with substantially uniform accuracy. The result, when used for example in the reproduction of musical selections, is much more pleasing and realistic than that obtained by the use of a mechanically actuated diaphragm.

When it is desired to apply or utilize the H scribed, may be mounted upon a supporting and counterbalancing arm 116 which may be mounted at the outer end of the tone arm 117 of the phonograph. Any suitable method of mounting may be used for this ur ose de ending u on the construcp p p to w ich the device is 7 tion of the tone arm to be applied. I have shown the device as applied in, connection with a tone arm which has at its outer end a laterally extending tubular portion 118 which, when used as a mechanical reproducing phonograph, serves to receive one end of a U- shaped connecting tube to the other end of which is attached a sound box. Such sound. box and U-shaped connecting tube may be removed and the stem or shaft 119 connected to arm 116 may be inserted within the tubular portion 118, said shaft being held in place for example by means of retaining screw 120. The reproducing device may be pivotally mounted as at 121 on supporting arm 116 so as to swing vertically. When the transmitting device is tilted backward for the purpose of changing the needle the counterweight 122 at the other end of arm 116 may be lowered to rest on a supporting finger 123. When the transmitting device is re-lowered onto the phonograph record, however the rear face thereof engages shoulder 124 on anfi 116 so as to lift the counterweight from its 0- sition of rest and decrease the effective weight of the transmitting device on the needle. The connecting wires 76 and 77, contained for example he suitable cord or cable 126, may be carried back along the tone arm and supported thereon in any suitable manner for example by means of clamp 127 and may as before be connected to the amplifying system any suitable manner as by means of connecting member 86'. The rheostat 78 which is connected in one of said wires may be mounted in any suitable position; for example it may be mounted as shown on the top of the tone arm near the base thereof.

Other means than that above described may be used for mounting the rocking member of the transmitting device; for example as shown in Figs. 15 and 16 the-bridge portion 46 of said rocking member may be mounted or held at its ends between solid supporting pads 48 by means of clamping brackets-130 which may be secured to the supportin plate 34 by means of screws 131. Raise points 132 may be provided, for example by the use of a punching or upsetting tool, in supporting plate 34 and in clamping brackets 130 in position to engage the centers of sup porting pads 48 so as to hold said pads firmly in position and the bridge member 46 may be provided with openings or holes 133 also in position to be engaged by the centers of supporting pads 48 so as to maintain the bridge member in centered position with-'re-' spect to said supporting pads. In this case I have shown the bent over portion 61 of the bridge member, to which the linkmember 59 is connected, as' extending above the bridge member rather than beneath the same, and adjusting screw 62 being provided as before for adjusting the relatlve'position of link member 59 and bridge, member 46. The remainder of the construction may be r substantially the same as above described and the manner of operation" thereof is also substantially the same.

I claim:

1. In apparatus for sound reproduction, a transmitting device, member provided with phonograph needle, means supporting said rocking member so as to permit rocking movement thereof about one effective axis only, armature means mounted to vibrate, and flexible link means eonnecting said rocking member to said armature means in such manner as to transmit to said armature means rocking movement of said rocking member about said effective axis, and electromagnetic means associated with said armature means and adapted to produce current impulses corresponding to the movements of said armature means.

2. A construction as set forth in claim 1, said. link means being adjustably connected to said rocking member.

3. In apparatus for sound reproduction, a transmitting device, comprising a rocking member provided with means forcarrying a phonograph needle, means resiliently supporting said rocking member so as to permit rocking thereof in one plane about an effective axis, armature means mounted to vibrate, electromagnetic means associated with said armature means, and link means connected to .said rocking member at a point removed from said effective axis and. also connected to said armature means, in such means for carrying a comprising a rocking manner as to transmit such rocking movemerit of the rocking member to said armature means, the point of connection of said link member to said rocking member being substantially in line with the efl'ective axis of said rocking member with res t to rocking motion thereof in another p ane perpendicular to said first-named plane.

4. In an electrical phonograph reproducer, rigid supporting-means, a rocking member provided with needle carrying means, resilient supporting and damping means between said rock ng member and said rigid sup porting means, additional resilientsupporting means at the other side of said rocking member, and clamping means engaging sai additional resilient supporting means and Secured to said rigid supporting means. so

as to clamp said rocking member between saidtwo resilient supporting means which constitute the sole support for said rocking member.

. 5. A construction as set forth in claim 4, and comprising in addition a magnet mounted on said" rigid supporting means, marmature mounted to rock in the field of sajdg j magnet and a flexible link secured atitsen to said armature and said rocking member respectively.

6. A construction asset forth claim and comprising in addition a magnetmonnted on said rigid supporting means, an armature mounted to rock in the fieldof said magnet, a flexible link seeured at its ends to said armature and said rocking member respectively, and means for adjusting the effective length of said flexible link between said rocking member and said'armatiire so as to pro ,erly space said armature in the field of sai magnet. Y

In testimony whereof Ihave hereunto subscribed m name this. 6th day of April, 1926.

' 4 JOHN J. JAKOSKY.

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