[PT031AAC1], Technical Note, Thomas Alva Edison, October 17th, 1888



Caeveat 112 phonograph: Improvements in phonographs & appliances## Fig 1 shews a method of governing the Electric Motor by causing the governor to throw in & out of the field of Resistance to slow the motor by strengthening the field and increasing its speed by diminishing the strength of the same. The governor might be dispensed with and an Extra Coil in series with the armature out wound to weaken the field when the load increases## Fig 2 shews the governor arranged to govern by friction## Fig 3 ##hews a Condenser around the governor break current contact to eliminate the spark## Fig 4 shews the governor provided with an index to indicate the speed of the phonograph$$ Fig 5 shews a turning off tool with pressure float, the foot resting on the turned off part while the knifes turning off the talking previously put on. The end of the knife being flush with the bottom of the pressure foot which prevents the same from riding up & down?The object of this form of tool is to render adjustments unncessary?the edge of the pressure foot turning off tool. Being sharp & slight tap of the finger start it at the right depth. I will mention here that a knife the full width of the phonograph Cylinder could be used in the form of a planing machine knife and with a pressure foot The Cylinder could be turne one rotation by hand & all the previous talking turned off—## Fig 6 shews a method of indenting without removing material the fig 7 shews the same?figs 8 9 & 10 shews knifes to produce the groove shewn in figs 6 & 7 fig 11 shews indenting without removing stock also fig 12 fig 187 fig 178 and fig 20 show other forms. Fig 13 shews a double recording tool so arranged and that say the front point makes a wave more abrupt at one end than the other to the right & the other end makes a wave more abrupt to the left as described in an application now pending by employing double point recievers The volume of sound is greatly increased—## fig 14 shews a Recorder or Receiver o the motion is reversed when used as the latter.## fig 15 shews a Triple recording tool.## fig 19 shews recording with leverage & yet producing a wave more abrupt at one end than the other## Fig 21 shews plate phonograph The speed of the disk being increased as the recorder approaches the center this being done by causing the movement of the screw arm to increase the speed of the motor by acting on the governor## Fig 22 shews a Recording Cylinder split in half & held on the phonograph cylinder by Rubber bands## Fig 23 shews a Recorder which by Reversing the motor of the recording cylinder becomes a receiver## Fig 24 shews a receiver with vane for dampening on the lever## Fig 25 shews the vibration of a wire to give waves to diaphragm of the receiver## Fig 26 shews a continuous sheet phonograph 4 or more Recorders & 4 or more Receivers are secured to a revolving shaft the hearing and speaking tubes being attached at the center so the tubes can stand still while the recorders and Receivers rotate. In revolving a portion of the travel in each takes place over a pl flat continuous roll phonograph which is fed at such a speed as to cause the records to be about g1/100g* each apart. This feeding may be continuous or intermittant taking place just as one recording point leaves the recording surface and the other comes on= devices are attached to raise the recorders & lower the receivers when receiving## Fig 27 shews the core of the mould for casting phonogram blanks wound with thred or string or narrow sheet paper or wire or metallic bank or cloth band or cloth mosquito netting etc. When the Cylinder is poured it adheres to this and it becomes a part of the cylinder causing the inner part to be quite true, rendering the sizing by reaming unnecessary and by the loose character of the inner coating causes it to be easily put on or off the phongraph cylinder to rack when left on & a cold snap comes up. This is especially true of [loose?] soft Cotton string— fig 28 shews the string inside of a moulded cylinder—## Fig 29 shews a Carbon telephone The connection being between the electrodes & the diaphragm being only through an air dash pot. Thus the previous difficulty of the change of initial pressure being changed by the buckling of diaphragm by continuous mechanical stress or Temperature, is obviated. The lever which gives the initial pressure is also provided with a dash pot. Fig 30 shews a motor directly connected to the phonograph## Fig 31 shews a mechanical movement for advancing the devices holding the recorder & Receiver Fig 32 is a disk with threads in it runs into a rack on travelling sleeve This being a variation of fig 31## Fig 33 shews a recording tool or Recorder without a diaphragm The sound waves impinge directly on a cup connected to the recording lever Fig 34 shews same thing with multiple disk## Fig 37 shew two diaphragms connected together & the the recording lever so as to get double power## Fig 38 shews a small glass disk very close to the diaphragm & secured to it around its edges so as to be air tight?This acts as a dash pot?fig 39 shews Recorder which makes waves very abrupt at one end. The movement of the lever to & from the recording material taking place is small arc of circle (ie) a circle of very small diamete—## Fig 40 shews a sinuous Curve recorder on a Round cylinder.## Fig 41 shews a duplicating device in which waves which on the master cylinder are not more abrupt at one end than the other are made so on the duplicate or if the master cylinder waves are abrupt at one end their abruptness is increased on the duplicate.## Fig 42 is a paper shell made tape on the inside but not on the outside and made in one piece.## Fig 43 shews a place phonograph?The feed being obtained by a worm on the plate shaft & worm wheel on the Traveller arms shaft.## Fig 44 shews device for increasing speed of plate as Recorder approaches center by cone pulley & shifter## Fig 45 shews Recording with pressure foot the whole resting on the cylinder but an adjustable shaving knife also travells with it which serves to smooth the cylinder in advance of the recording point— Fig 47 & 48 shews graphophone phonograph with false shell over which cylinders or collapsable cylinder phonogram can be shared## fig 49 shews a squirter for squirting out flexible sheets of material to coat the collapsable paper cylinders of collapsable mailing phonograms## Fig 50 shews a solid cylinder all of recording material?fig 51 shews a solid plate of recording material for use on plate phonograph a turning off tool is of course used to shave the records off. In this form a plate phonograph would last a year (ie) one cylinder would be sufficient.## I am engaged on a great number of experiments to obtain a suitable material for colapsable phonogram blanks; Asphalt melted and mixed with Japan wax.## This used directly or coated with a film of Chicle, Balata, Gelatin softened with Molasses or a film of flexible Collodion or plastic sulphur or Oleate of Aluminum magnesium in## Paper shells coated with tin foil & then dipped in various recording material serves to prevent air bubbles due to water in paper & gives beautiful surface?by dipping paper direct in hot solution considerable air bubbles appear; by turning off smooth & redipping these generally disappear but the best method is to dip in solution & secure it to a machine which gives it a moment of rotation in two opposite directions & if this is done in a hot place the distribution of the material is perfect, in fact I have used this to cause Asphalt in Benzol solution to be evenly spread over dynamo armature plates & I propose to use the machine for evenly distributing Japan Varnish over irregular iron parts of the phonograph?I shall make application for a patent for this## for flexible cylinder Oleate of Lead may be used?this dipped in Linseed oil or olive oil & the Linseed oil exposed to fumes of Chloride sulphur or a Chlorinating Liquid Like pentchloride antimony causes a very thin film to coat it. The olive oil exposed to Hyponitric acid does same thing## Soft material such as Oleate Lead, Japan wax, [sterinc?] pitch, or fatty oil pitch etc on paper turned off & then dipped in a resin in alcohol, Bitumen in Bisulphide Carbon or Benzol, Japan Varnish etc to give polished elastic film indent without cutting## For mailing cylinders Oleate Aluminum mixed with hard Oleates Chloroleates of Alumina also Magnesia Gelatin mixed with Albumen & various other amorphous substances Finely divided powder like Kaolin mixed with Oleate Lead & squirted & sheets cut & put on paper cylinder in two halves, or Trihydrate Alumina mixed with Oleates or Chlorooleates of Alumina or Magnesium Stearate of sulphur, flexible [sulphur?], a very good surface for Colapsable Phonogram is Yellow ozokerite melted & mixed with Camphor which serves to render it lsess sticky & yet retains flexibility. The sticky function of all the flexible waxes etc causes the Recording point to become clogged T A Edison








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[PT031AAC1], Technical Note, Thomas Alva Edison, October 17th, 1888

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Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University