US2537194A - Phonograph control mechanism - Google Patents

Description

Jan. 9, 1951 R. M. SOMERS 4 2,537,194

PHONOGRAPH CONTROL MECHANISM Filed Nov. 5-, 1945 Sheets-Sheet 1 y f INVENTOR i 1c7zarcl MSomem TTORNEY Jan. 9, 1951- R. M. SOMERS PHONOGRAPH CONTROL MECHANISM 4 Sheets-Sheet 2 Filed Nov. 5, 1945 JNVENTOR R1 ch arcZ M Somers BY ATTORNEY Jan. 9,.1951 R. M. SOMERS PHONOGRAPH CONTROL MECHANISM 4 Sheets-Sheet 3 Filed Nov. 5, 1

- 7 :muuunum INVENTOR -723.762 MSOTZZQTS 'OR'NEY Jan. 9, 1951 R. M. SOMERS 2,537,194

PHONOGRAPH CONTROL MECHANISM Filed Nov. 5, 1945 -4 Sheets-Sheet 4 AMPLIFIE Q I L-- 1Z 0 .L.

XNVENTOR RIICZZELTCZ M. amers ATTORN EY V Patented Jan. 9, 1951 UNITED STATES TENT OFFICE PHONOGRAPH CONTROL 'MECHANISll/I Application November 5, 1945, Serial N 0. 626,712

3 Claims. 1 g This invention relates to phonographic machines and more particularly to those commonly known as dictating machines.

The dictating machine of the present invention embodies several interrelated improvements which make the machine more convenient to operate and to service.

In its basic structure, the present machine follows the conventional arrangement wherein a wax-like cylindrical record is supported for rotation and a carriage is advanced or fed along the said record. In such a carriage there is provided a mechanism or unit adapted selectively to engage the record for either recording sounds thereon or reproducing sounds therefrom. In the machine of the instant inventionhowever, the unit mentioned above is one adapted to operate electrically, as distinguished from the more common type of acoustical device or unit.

It is an object of my invention to provide in a proved form between operating mechanisms in relatively stationary and movable ortions of the phonograph cabinet so as to enable these mechanisms to be readily disconnected to permit open- Fig. 3 is a vertical section, slightly enlarged,

taken along line 3-3 of Fig. 1;

I Fig. 4 is a section through the amplifiers controlling switch, as taken on line 4-4 of Fig. 5; Fig. 5 is a section on line. 5-5 of Fig. 4;

Fig. 6 is afragmentary view, as seen along the line 6-45 of Fig. 3;

Fig. '7 is a horizontalsectiontaken along line 1-.1ofFig.2;, "Fig; 8 isa side elevational view of a modified form of linkage; for the controlling switch of the amplifier shown in Fig. 3; Fig. 9 is a front elevational view of the linkage of Fig. 8, and I Figgilqjs a diagrammatical view showing the 2p phonograph a separable link-connection of imarrangement of the several circuits forming the electrical system of my present dictating machine.

Referring particularly to Figs. 1 and 2, there will be seen a cabinet I, closed at its top by a relatively heavy cast plate 2 adapted for the support of the operating mechanism of the machine. The top-plate 2 is hinged at 3 to the back of the cabinet, and it is supported at its front upon a bracket i, to which 'it may be fastened by a thumb-screw 4' to prevent accidental dislocation and vibration of said plate. The bottom of the cabinet I is closed by a plate I having suitable openings I" (see Fig. '7) provided for ventilation in a manner hereinafter more fully described.

The top-plate 2 is provided with side standards 5 and 6 for supporting the cross-rods l and 8, and is further provided with an intermediate standard 9 for supporting a mandrel H] which is used as a support for the cylindrical wax tablet II. The record support In is conventional and its detail of construction follows the disclosure of the Gramann Patent No. 2,010,717, issued August 6,

1935. During the operation of the machine, the support it is rotated by an axially aligned pulley [2 connected by a belt l3 to the motor M, which is suspended below the top plate 2 by a commonly known spring structure M, shown in Fig. 2. The rotation of the record support IE is arranged to be controlled by the operator, and for this purpose the connection of the support NJ with the pulley l2 comprises a clutch mechanism M operated by a member l5 and a link It associated with an electro -magnet device I1. The device H is enclosed in a box as shown, and it is under control of a hand-switch l8 on the mouthpiece or microphone !9 as hereinafter more fully pointed out.

A carriage 29 is mounted on rods 7 and 8 above the record tablet for movement thereacross. The carriage is moved by a feed-screw 2| mounted parallel to the rods 1 and 8 on the standards 5 and 6. The feed-screw is turned in ratio with the mandrel, and for this purpose it is geared at 22 with a pinion 23 secured to the mandrel shaft Ill. The carriage is provided with a long sleeve 24, by means of which it is accurately supported and slid along the rod 1. On this sleeve within the hollowed portion of said carriage, there is mounted a camming block or member 25, see Figs. 1 and 3.

'This block is turned or moved in an arc about the sleeve by a control lever 26; the movement being efiected by a link 21 connected to the lever at 26' and the block at 25. The movement of the block 25 is to control the engagement or disengagement of the feed-nut 28 of the carriage with or from the feed-screw 2| and, moreover, to cause the rod 1 to be rocked in the sleeve and consequently in its journals in the standards and 6. For this last purpose, the cam block 25 has a key in the form of a set-screw 29 passing through a suitable arcuate slot made in the sleeve 24 and engaging a longi tudinal key-way 3| made in the rod 1. The control lever 23 is also provided for simultaneously controlling the electrically operated unit 30 which is supported in the forward portion 2| of the carriage 2i! and which is adapted for selective operation upon the surface of the record H, such as for operation with a cutting tool for recordation, or operation with a pick-up stylus for reproduction. This unit need not essentially be of a specific construction in order topracti'ce the present invention, however, for the present purpose, this unit is generally illustrated as being of the piezoelectric type and its specific construction need not be shown and described herein, as such a unit is fully disclosed in a co-pending joint application of the present inventor and Charles W. Dann, Serial No. 604,316, filed July 11, 1945, and having a common assignee with the present application.

An electro-acoustic recorder-reproducer unit, as here employed, requires the use of an electronic amplifier. The amplifier structure, which is generally indicated at 3|, is located at the bottom of the cabinet portion The structure first comprises a metallic receptacle or chassis 35, the solid bottom 35 of which is made to rest and be secured on the bottom plate I, forward of the ventilating openings I" thereof, but with an insulating plate 36 between the said bottoms so that no electric contact is made therebetween. The electronic tubes 31 for the said amplifier are mounted to the rear wall of the chassis to extend rearwardly as shown; at a distance above but offset from the openings The necessary components and the wiring for the amplifier *are provided within the receptacle 35, and leads thereof such as 38 and 39, are connected respectively to an on-and-oif switch 40 and volume control unit 4|, both of which have respective manual means 40' and 4| extending to the front of the cabinet I for control 'by an operator. Similarly, a pilot light '42 may be connected in the position shown to indicate the condition of the amplifier. Mounted directly on the right side 35a of the chassis 35 is an output-input controlling switch 43 for the amplifier 3|, operable as hereinafter described by the control lever 25.

As the driving motor M and the amplifier 3| are both located beneath the top plate 2, considerable heat is generated in the cabinet I. Accordingly, provision is taken todissipate said heat to prevent the heavy plate 2 from getting hot to a point of generating hot-air currents thereabove and which would directly effect and "lower theeificiency of the wax cylinder H. To

this end, an air-blower 45, supported at 46 to the motor M and driven thereby through a belt 41, is provided so as to draw air from the openings I" into the cabinet, then direct the air outwardly through the louvers 48 provided into the rear of the cabinet as shown in Figs. 2 and '7. The details of the ventilating system need not be described in total here, it being sufiicient for the present purpose to state that such a system emplcys a metallic partition such as fill in the pres- 4 ent drawing, to protect the amplifier and to serve as abafiie in the ventilating system. Partition 5G is directly secured to the metallic chassis 35 and it extends rearwardly but does not contact with the rear wall of the cabinet I. It is detachably held to the chassis by the screws 5|, and it is adapted to support along its rear a dished plate 52 serving as a drip pan for the motor M. The dished plate 52 has a downwardly bent portion 52 which however is adapted to touch or contact the rear wall of the cabinet I. Advantage is made of this particular structure to form an electric capacitor (indicated as 53 in the diagram of Fig. 10) between the metallic body or cabinet I of the machine on one side and that of the amplifier chassis 35 on the other side. The capacitor 53 is of course predetermined in value when the assembly, comprising the cover plate 53 and pan 52, is in manufacture. For this purpose, an insulating sheet 54, of a chosen thickness, is placed between 50 and 52 and these parts are held firmly together by insulated screws 53. In determining the value of the capacitor 53, attention is given to the thickness of the insulating pad 35 used between the metallic bottom 35 of the chassis and the metallic bottom l of the cabinet, as here too anelectric capacitor may be formed. I make the pad '36 of a considerable thickness so that a'very small capacity is created between the two bottoms l and 35 and this small value is then taken as a factor in determining the capacitor 53. The bottom 35 of the amplifier is held to the bottom I by means of suitable insulated screws not necessary here to show.

From the above, it will be understood that the chassis 35 of the amplifier is not grounded or in direct electrical contact with the cabinet I of the machine. Accordingly, viewing Fig. 10, it will be seen that the circuit, indicated as 58, forthe combined'recorder-reproducer unit 30 is not grounded or in electric connection with either the chassis 35 or cabinet I. The unit 30 has a frame which is insulatedly mounted in "the carriage 20 as is shown and described in the co pending joint application mentioned above, and the circuit 58 therefor has a lead 58a which is directly connected to the B" of the amplifier as here shown. The other lead 58b of said circuit is connectable by the abovementioned switch 43 with the amplifier, either at the input or output thereof accordingto the position of said switch as hereinafter explained. In a similar manner, the microphone l9 has a circuit 59 of which one lead 59a. is connected to the B' of the amplifier, and'another lead 59?) is connectable by the switch 43 either to the input or output of the amplifier, as determined by the position of the switch 43. Preferably, the leads 58a and 59a respectively comprise the'metallic braided portions of the ordinary form of the shielded cables respectively used forthe corresponding higher potential leads or'wires 58b and 59b. Also, in the present instance 'the'said metallic braided portions of said cables are covered with insulation so that they are prevented from making-electrical contact with the chassi's'of the amplifier and cabinet of the machine.

The switch 43, through which the leads 58b and 59b are connected, is a'rotary shielded unit whoseouter metallic casing is at 3- potential. It is mounted insulatedly on the chassis 35 by means of a Bakelite pad 32 and the insulated screws 33. This switch is preferably of the type described and claimed in the'Dann Patent No.

2,280,143 issued April 21, 1942 and having a common assignee with the present application. The casing of the switch 43 is composed of two circular portions 60 and BI. The portion 60 is held stationary onto the wall 35a by the screws 33 and it has a projecting central portion in the form of a hub 62 onto which the portion BI is mounted for rotation. A large headed screw 63 holds the parts together as shown in Fig. 5. The portion 66 carries a plurality of terminals 65, 66, 61, 68, 69 and 10, all imbedded in suitable cylindrical insulating elements press-fitted into the base of said portion 60, and said terminals are extended outwardly as shown to provide means for soldering the leads which are to be connected to the switch. The portion 6I has transverse metallic walls 6Ia forming two distinctive shielded compartments II and 12, into which are mounted respective resilient contact members I3 and I4 adapted to bridge across the heads of the several terminals in the portion 60. In this respect, the contact member 13 is adapted to bridge across and form a circuit between the terminals 66 and 65, or it may, according to the position of the switch, form a circuit between 66 and the terminal 6'1. Similarly the contact member I4 is adapted to form a circuit by bridging across the terminals 68 and 69, or it may form a circuit between 69 and 10. It will be clear from Fig. that the terminals 65, 66 and 61 are related to the high potential lead 59b of the circuit 59 for the microphone I9, and that the terminals 68, 69 and 16 are related to the high potential lead 58b of the circuit 58 for the combined recorder and reproducer 30. Accordingly, as the portion 6I of the switch 43 is turned with the bridging portions 73 and 14 thereof engaging their respective groups of terminals, the leads 5% and 5% will be alternately changed from input to output or vice versa, to place the microphone I9 in the input side of the amplifier and the unit 30 in the output side, or to place the microphone in the output side and the said unit in the input. In this last position of the switch, the microphone I9 is used as a loud speaker,

In order that the lead wires of the electric system may be as short as possible, the controlling switch 43 is mounted directly on the amplifier as explained. However, in order to control said switch as an incident of moving the control lever 26, a special means is provided by my invention to connect said lever with the switch and yet preserve the hinging feature of the top plate 2 so that it may be moved about its hinge 3 without interference from such a connection. For this purpose, there is mounted onto the rod I an arm 80, which is held fast to the rod by a screw 8I and which has a pivotal connection at 82 with a member 83. The member 83 has an upper extension 84 pivoted at 85 to a vertical section 86 of a separable link-connection generally indicated as 90. To adjust the section 86 relative to the angular position of the arm 80 on the rod 1, the member 83 has a downwardly extending portion 81 provided with an eccentrically disposed arcuate slot 88 engaging a stud screw 89 on the member 86. Movement of the member 83 about its pivot 82 will cause the slot 88 slightly to raise or lower the link member 83, and the stud screw may be tightened to preserve the adjustment. The link section 86 passes through a slot 99' in the top plate 2 and carries at its lower end a v-shaped spool 9I adapted to engage the bifurcated upper end of a lower link section 92. The section 92 is held in a vertical position by a bracket 93 welded to the cabinet at 94. The bracket has a face 95 against which the section 92 rests, and a pair of spacers 96 cooperating with a cross-plate 9! to form a guide-way 98 (Fig. 7) for the vertical movement of the said section; there being an allowance for a slight play of the, section 92 in the guide-way 98. The link section 92 is urged upwardly by a spring 99, stretched between the plate 91 and an extension I00 at the lower end of said section. A stop lug IOI is adapted to abut against a set screw I02 threaded in the plate 91 so as to define the limit of upward movement of the section 92. The extension I00 is pivotally connected at I03 to an arm I04 on the switch 43; the arm being of an insulating material so as to preserve the identity between ground and B potentials and being secured to the switch portion 6I.

With the parts of the connection 90 thus described, it will be clear that the switch-portion 6| will be in its most clockwise position when the arm/ is in its uppermost position and the control lever 26 is in its lowermost or recording position, as is seen in Fig. 3. Accordingly, in this position of the switch, the members I3 and 14 thereof respectively bridge between contacts 66 and 61, and contacts 69 and I9. This causes the microphone I9 to become connected to the input of the amplifier and the combined unit 30 to be connected with the output of said amplifier. Reversely, if the control lever be moved to its uppermost or reproducing position to cause the rod 1 to rotate and swing the arm 80 down to its lowermost position, then the link connection will be operated to hold the switch in its most counterclockwise position to cause the bridging members 13 and 74 thereof respectively to bridge across the contacts 65 and 66, and 68 and 69. The unit 30 is thereby placed in the input side and the microphone in the output side of the amplifier so as to function as a speaker. As described, the link mechanism 90 lends itself quickly to separation as the top plate 2 is raisedv about its hinge 3; the link becoming automatically reunited as the plate is again lowered.

In Figures 8 and 9, there is shown another form of separable link connection, according to my invention, for the controlof the switch 63. In this showing the rod I carries an arm IIJ connected by a link I I I, to a lever I I 2 pivoted on the rod 8. The lever is composed of two spacedapart plates I I2a and H212, and it is apertured through both the forward portions of said plates so as to form a socket II 3 for receiving a hard ened ball II4 carried at the upper, end of a link I I 5, whose bottom end H5 is connected to the aforementioned arm I94 of the switch 43. With this mechanism, the top plate may also be raised freely. However, during its upward movement, the arm I64 will follow only until it has reached its most clockwise position and thereafter the ball II4 will be forcefully disconnected from the socket II3. In reestablishing the connection, it is necessary to hold the link II5 up by meansof a tool, such as a screw driver, engaging a notch H6, and forcefully reengage the ball with the socket by pressing upon the forward portion of the lever II2. The link II5 is normally held in a vertical position by a bracket II'I having a guide way I I8 as shown.

As is customary, the control lever 26 is adapted to be moved to and held in a mid position where it establishes a condition of inoperativeness of the combined unit 30. With either of the link mechanisms described above the switch 43 is rendered inefiective when the lever :is :so moved, as both the elements 1.3 "and 14 of the switchare then in positions between their respective sets of contacts-05, 06, '01, and 68, 69, 10, and the associated circuits :58 and 59 will be accordingly opened.

:In 'the present machine, a marked improvement of quality of recordation and of reproduction is achieved by placing in the circuits '58 and 59 respective filters, such as indicated at I20 and 121 in 10. The filter I20 is auto! matioally placed in circuit by the switch 03 as said switch is operated to place the recorder stylus of the combined unit in the output side of the amplifier; and the filter I2I is in turn automatically placed in circuit when the microphone is alternately selected for the output of the amplifier so asito serve as a speaker. Accordingly, rfilter I20 which is a high-pass filter, as-designated, serves to discriminate against the band oflower sound frequencies which are passed through the amplifier, and, in efiect, to accentuate the band of the higher sound frequencies so that theirrecordation on the tablet l I will be moreprevalent; and the filter I2! which-is a lowpass filter, 'as designated, serves to reverse this order during playback as the action of this filter reduces the ratio of the high to the low frequencies back to normal, i. e,, as they were in the original voice, but in addition it acts to reduce thehigh frequency record scratch. As this scratch was not accentuated during recording the net efiect of the two-filter system is to give a high quality of play back with a high ratio of desired signal to record surface noise, i. e. scratch.

While I have-chosen to show a circuit arrangement wherein the filters I20 and I2! are alternately connected'with the output of the amplifier, as an incident to the operation of the selective switch 43 fol-connecting the units I9 and 30 with the amplifier for either recording or reproducing, it will be understood that said filters may be so connected with the input of said amplifier, if :desired. For instance, the filter I2! could be connected between the junction 58 and the input terminal 65, and the filter I20 connected between the junction 59 and the input terminal 61. In such case the terminals 68 and I associated with the output would have direct connections with the units It and 30 respectively. Moreover, if it were desirable,either one of the two filters could be arranged for connection with the input'sideand the other filter with the output side while still using the same switch 43. This would be done by-connecting one filter between terminal 61 and the input, and the other filter between terminal 65 and the output, and also by connecting'terminals 66 and 60 respectively with the appropriate ones-of the units I9 and 30. The terminals 08 and 19 would then be connected respectively to input and output. In this case, the B- terminal would again complete the circuit for both the units I0 and 30. My primary object is to automatically introduce a band pass filter in the amplifier circuit during recording and another band pass filter in said circuit during reproducing.

In Figure 10, it will beseen that the aforementioned switch 40 is used as a master switch in the current supply circuit established by the plug-in cable I23, and that a second switch, such as the usualhook-switch I24, is used to control the motor circuit I25. In this last circuit there is used a resistance 120 which is in-series with 8 themotorMas shown. This 'resistanceis divided ataany desired intermediate point, for instance as at I26, and a circuit I21 comprising a switch I28 is establishediin a manner to provide shorteningot the resistance by closing said switch I28. When the :motor M is to be used in connection with a source of .high current supply or D. Cf. current, the switch is kept opened so that the resistance 126 will be fully effective to reduce the current. On the other hand, if a comparatively lower source of current supply or A. C. current is connected. to the motor, the switch I28 is closed so that only aportion of the resistance willbeefifective to cause the motor to operate at a more eflioient rate. Accordingly, A. C. and D. C. currents and/or difierent values of current maybe used and appropriately controlled by this arrangement.

'Nofear need be entertained as to the possibility of the present machine producing electrical shock to the user. This is because the cabinet has no direct-connection with the wiring system or with the potential of the cable I23. Accordingly, the machine may be set anywhere, even upon a metallic surface directly connected to earth; without ill efiect. This is exemplified at I30 in the drawing. To provide proper ground return for the efiicient working of the amplifier, a condenser I3I .is connected between the 3- terminal and the chassis 35, as seen in Fig. 10. This condenser may have an approximate capacity of .250 mi, and the capacity formed by the plates 50 and 52 may approximate 0.0025 mf.

For convenience of use of the present machine, there is provided a plug-in receptacle its at the back of the cabinet 'I as shown. To the righthand side of the cabinet there is provided another convenient connecting means I34, which latter is used for the attachment or detachment of themicrophone, as is shown in Figs. 1 and 3.

I claim:

1. In .a phonograph: the combination of a cabinet havlnga stationary base portion and a movable cover portion mounted on said case portionrfor movement into open and closed positions; a selector device in said base portion for controliing the condition of the phonograph; a reciprocable hand control mounted on said cover portion for movement relative thereto and adapted for operating said selector device; and a-separable coupling between said hand control andsaidselector device comprisingfirst and second links coupled respectively to said hand control and said selector device and carried permanently with said cover and base portions respectively, mountings on said cover and case portions for said first and second links respective'y for guiding said first link into releasable engagement with said second link as said cover portion is closed, and spring means associated with one of said links .for yieldably mantaining the same in operative engagement with the other of said links within the range of back-anddorth actuationof said first link by said hand control while said cover portion is closed.

2. The combination set forth in claim 1 wherein said links are guided into abutment with one another as said cover portion is closed, and wherein said spring means urges said second link in opposition to its direction of actuation by said first link with force sufficient to maintain operative engagement between the links throughout the range of actuation of the first link by-said hand control. 7

10 Y 3. The combination set forth in claim 1 in- UNITED STATES PATENTS eluding a bell associated with one of said links Number Name Date and an arm carried with the other of said links 504 980 Hall Sept 2 393 and spaced a distance therefrom less than the 16751165 g i; J ly 9 diameterEef said ball, said arm and other link 5 1973'378 Graesser "Sept 934 being yieldable in directions towards a from 2152261 n mi Mar. 28' was each otherand having aligned apertures for re 2170o50 Aug 9 9 ceiving said ball and for operatively intercom 2226745 schrack 940 necting the links upon forcemen of said ball 29 430 Warner Jan. 2i 1941 between said arm and other link into Said 3 Norton Dec 2 1941 apertures. 2:2 :49; Lynn June 16: 1942 RICHARD SOMERS- 2,305,681 Dunning Dec. 22, 1942 REFERENCES CITED 2,396,311 Blnus 1 1 The following references are of record in the 5 file of this patent:

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