US2181940A - Recording unit - Google Patents

Description

Dec. 5, 1939. c. J. FITCH nu. 2,181,940

RECORDING UNIT Filed Nov. 19, 1957 I 9 Sheets-Sheet i m Iv by s ATTORNEY Dec. 5, 1939. c. J. FITCH E1 AL RECORDING UNIT Filed Nov. 19, 1957 9 Sheets-Sheet 2 14 FIG. 3.

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RECORDING UNIT Filed Nov. 19, 1937 9 Sheets-Sheet 3 nzil FIG. 60.

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- J. F'iTcH ET AL RECORDING UNIT Filed Nov! 19, 1937- 9 Sheets-Sheet 4 ATTORNEY Dec. 5, 1939 c. J. FITCH ET'AL RECORDING UNIT Filed Nov. 19, 1937 9 Sheets-Sheet 5 FIG. 12.

' A'TTORNEY Dec. 5, 1939. J F TcH ET AL 2,181,940

RECORDING UNIT Filed NOV. 19, 1937 9 Sheets-Sheet 6 ATTORNEY 1939. c. J. FITCH Er AL 2,181,940

RECORDING UNI;-

Filed Nov. 19, 1957 9 Sheets- Sheet 1 FIG. 19.

ATTORNEY Dec. 5, 1939.

C J. FITCH ET AL RECORDING UNIT Filed NOV. 19, 1937 9 SheetsSheet 8 o FIG. 206.

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ATTORNEY- 5, 1939. c. J. FIVTCIH El AL.

RECORDING UN I'T Filed Nov. 19, 1937 9 Sheets-Sheet 9 I Rs Patented Dec. 5, 1939 UNITED STATES PATENT OFFICE RECORDING UNIT Clyde J. Fitch and Kurt R. Schneider, Endicott, -N. Y., assignors to International Business Machines Corporation, NewYork, N. Y., a corporation of New York Application November 19, 1937, Serial No. 175,370

2 Claims.

receive signal conditions employed in known printing telegraph systems.

Another object of the present invention is the provision whereby the transmitting and receiving means associated with the machine are so arranged that upon operation of a control device the machine is conditioned to transmit and receive the signaling conditions.

Another object of the invention is the provision whereby the mechanical connections between the keybars and typebars are not modified so that the machine as arranged for printing telegraph control purposes still has the same utility as an ofiice recording machine as ordinarily used and applied for standard ofiice operation.

Still another object of the present invention is the provision of a control device to condition the machine for three difierent operations-(1) for standard typing operations, (2) for recording of characters in accordance with the signal conditions initiated and transmitted to the transmission medium, and (3) for recording of characters in accordance with the signal conditions impressed on the said medium and received by the machine. I

Still another object of the invention is the provision of permutation units adapted to he operated by the keybars to initiate character signal conditions and also adapted to be operated by the received signal conditions to selectively operate the said keybars accordingly.

Still another object of the invention is the provision of individual groups of permutation units to be controlled by the keybars and to control selectively the operations thereof.

Still another object is the provision of one permutation unit cooperating directly with the keybars to operate them and another permutation unit cooperating with the power operated units which are selectively tripped by the operated keybars.

Further objects of the instant invention reside in any novel feature of construction or operation or novel combination of parts present in the embodiment of the invention described and shown rnitter-rece v in the accompanying drawings whether within or without the scope of the appended claims and irrespective of other specific statements as to the scope of the invention contained herein.

In the drawings: 5 Fig. 1 is a sectional view showing'the standard mechanism of one preferred type of recording unit.

Fig. 2 is an exploded view showing the normal position of certain of the parts of the power operated units. Several structural features of the elements are exaggerated to show clearly the relative positions thereof.

Fig. 3 is a sectional view of one group of permutation bars cooperating with the power operated units.

Figs. 4 and 5 show the elements in Fig. 3 in operated positions.

Figs. 6 to 6--E are detail views of the transmitting permutation bars.

Fig. '7 is a detail view showing the arrangement of the contact controlling means.

Fig. 8 is a detail view of a selector member.

Fig. 9 is a detail of a selector finger.

Fig. 10 is a sectional view along the lines i0iEi of Fig. 11.

Fig. 11 is a plan view of the transmitting unit.

Fig. 12 is a sectional view along the lines l2i2 of Fig. 19.

Fig. 13 is a sectional view showing the receiving permutation unit associated with the recording unit.

Fig. 14 is a detail view of the driving gears of the receiving unit.

Fig. 15 is a perspective View of the receiving permutation har unit.

Figs. 16 to 18 are detail views of the clutch mechanism shown in Fig. 15. v

Fig. 19 is a plan view of the receiving permutation unit. w

Figs. 20 to EIL-E are detail views of the receiver permutation oars.

Fig. 21 is a circuit diagram showing the appli= cation or" the present invention to one type known printing telegraph system.

fig. 22 is partial sectional view of the transtive purposes, this invention shown as er "cg a well known type oi recorcling unit, wh be similar in construct to the Electro' atic typewriter, shown scribed in .detin U. S. Patent No. lfi'l'lfi' i and hence only the following brief scription.

Referring to the drawings and particularly to For illusti Fig. 1, well known means are provided for actuating the typebars I6 comprising a constantly rotating roller I0, cooperating with a series of individual power units each comprising a cam II, the engagement of the cams with the roller being controlled selectivelyby the character keybars II.

Any suitable means may be provided to rotate the power roller, in the direction indicated by the arrow, which is adapted to cooperate with two rows of cam units arranged in the front and rear of the roller. The cam II may be provided to be pivoted on one arm of a bell crank lever I2 which is pivoted in the frame-of the recording unit, as indicated generally by reference character I3, the other arm of the said bell crank lever is operatively connected with an arm of bell crank lever I4 by means of link I5. Another arm of the said lever I4 is connected to the type- .bars I6 in a well known manner, so as to effect operation of the typebars or any other suitable means connected to the bell crank levers upon selective operation of the controlling keybars I1.

The pivoted bell crank lever I2 is operated by 4 -In this position the impeller-arm I8 is urged, by

the associated coil spring I9, against one of the impeller-lugs 20, which at the time is in the lower position, and tends to turn the cam I I in a clockwise direction. This is prevented, however, by the engagement of one of the detents 2| on the cam, with the upperstop lug 22 on the stop lever 23; If. however, the corresponding keybar is operated, the b furcated lower end (Fig. l) of extension arm 24 associated with one of the said keybars I1 en a ges anarm 25 at the upper end of the stop lever 23 which is provided with an offset project on at its end which extends laterally through an opening in the bell crank lever I2. The arm 25 of the stop lever 23 is then swung rearwardly or to the left as v ewed in Fig. 1 about the pivot 26 and its lower end forwardly or to the right as viewed in this fi ure thus releasing the cam. wh ch then turns under the influence of the spring urged impeller-arm I8. In doing so the upper serrated lobe of the cam is brou ht into engagement w th 'the power roller, which turns in a counterclockwise direction and therefore causes a cont nued rolling movement of the cam until the h gh point has been reached and passed. This causes the whole cam unit to swing around the p vot I3 so as to pull down the corresponding link and actuate one of the typebars or any other mechanism with which the cam unit may be connected.

After the high po nt of the cam is passed the cam loses contact with the roller, but the said impeller-arm .I8 tends to continue the rotation thereof by engaging the second impeller-lug 29 of cam I I until the second detent 21 engages one of the stop lugs. Since the half rotation of the cam consumes only a small fraction of a second, it is difficult to release the keybar within this short interval, so that it is the lower lug 28 whereupon the impeller-arm rotates the cam and be actuated by the power roller in turn;

operating the associated bellcrank lever and its attached links to cause the associated mechanism such as the typebars and other operating mechanisms to be operated. It is to be understood that an individual cam unit is provided for each typebar or other functional mechanisms associated therewith.

The action of the cam mechanism has been described with respect to one of the rear bank of cam units; in the case of those of the forward bank the operation is analogous, but the directions of movement, and the order of operation of the stop lugs, is reversed. For example, if the bifurcated arm 24-a is positioned to engage the arm 25--a at the upper end of stop lever 23-41 by virtue of operation of the associated keybar, the said arm is positioned rearwardly or to the left as viewed in Fig. 1, and the lower end of the stop lever 23a is moved forwardly, that is. to. the right as viewed in the said figure. This said operation is effective to release the cam, by virtue of positioning the lower stop lug 28a out of the path of detent 2I-a, thus permitting the spring-urged impeller-arm I8-a to rotate the cam slightly in a clockwise direction to effect engagement of the lower lobe of cam II and power roller. Upon completion of a half revolution of the cam I I, the second detent 2'I--a engages first the upper stop lug 22-a while the stop lever 23a is in an operated position, but upon. release of the associated keybar and the return of the said stop lever to normal position, this lug 22-a disengages the said detent and the impeller-arm rotates the cam slightly sothat the said detent then engages the lower stop lug 28--a, as shown in the figure. In this manner the bellcrank lever I2a is rotated about the pivot I3--a. to

operate the associated typebar or any other mechanism associated therewith. For further structural details of the cam units, reference should be made to the above mentioned patent. The description just set forth related to a standard typewriting unit and the mechanical connections between the controlling keybars and typebars. The permutation bar units condition the transmission medium in accordance with the selected characters and control the recording of the said characters at the transmitting station, and the permutation bar unit which is controlled by the conditioned medium to select the keybars in accordance'with the conditioned medium and thereby record the characters accordingly will now be explained. It is to be noted that the described mechanical linkages between the keybars and typebars are not modified in any manner so that the unit can be conditioned for three different types of operations, namely, as a printing telepgraph transmitting printer unit, as a printing telegraph receiving printer unit, and as a standard ofiice typewriting or recording unit.

Referring now to Figs. 3 to 11 and 22, the transmitting permutation unit associated with the electromatic typewriter will now be described.

The bell crank levers I2 are provided with arms 30 depending therefrom and on which are rotatably mounted individual cam rollers 3| which are displaced whenever the associated bell crank levers I2 are actuated by the released cams H. The cam rollers 3| are positioned so as to be adapted to position or displace control members 32 whenever the said rollers are displaced, for a purpose now to beset forth.

The permutation bar mechanism will now be described and by referring to Fig. 11 is shown to comprise generally a plurality of permutation bars or rods 33 provided with keys or fingers 34 and a plurality of selector members 32 (see Fig. 8) provided with tabs or studs 35. More specifically, a permutation rod comprises a shaft 36 fiat on one side as shown by reference character 3'! so that the tapered keys or fingers 34, having correspondingly shaped openings at the untapered section, (see Fig. 9), may be fitted on the said shaft, so that the keys are positioned or rotated in accordance with the shaft. Tubular spacings 38 are provided for accurately spacing the various keys on the shaft 36. It is to be noted that the keys are selectively arranged on the shafts so that some of the tapered ends extend or protrude above the shaft and some extend below or depend from the shaft, the purpose of which will be understood as the description progresses (see Figs. 6 to 6-E).

The shafts 36, of which, in the present example, six are shown, are rotatably mounted in the end plates 39 which also support grooved rods iil. This unit just described and generally designated 4| (Fig. 11) is pivotally mounted at 32 to the typewriter frame by members Q3 and is adapted to be locked or fixed in an operating position by being secured to the typewriter frame by means of the bolts and nuts shown generally at M.

It was mentioned that a plurality of selector members 32 are provided and adapted to be engaged by the cam rollers 3i to be positioned thereby. The selectors 32 are shown slidably mounted on the grooved rods 58 and are all identical in structure. A detail of a selector 32 is shown in Fig. 8 and comprises a member provided with similar forked or bifurcated ends 5; at one end thereof extensions to are provided and as shown are adapted to be engaged by the cam rollers 3! to be positioned thereby. Each selector is provided with a rectangular opening- 37 so as to be able to straddle the permutation bars 33; and also along one section of the selector member equally spaced tabs or studs 35 are fixed thereon, three studs on each side of the member and alternatelypositioned thereon.

The selectors 32 are slidably mounted on the grooved rods 50 and held in alinement or position by the grooves. Some of the selectors are arranged so that the studded sections of the selectors are above the bars 33 and others are arranged so that the studded sections thereof are below the bars 33; that is, the selectors are positioned so that the studs of some lie in the plane of the keys extending below the bars 32-3, and so that the studs of some lie in the plane of the keys extending above the bars.

The purpose of the described arrangement is to permit the studs 35 to engage certain of the keys 34 when the. selectors 32 are displaced due to the typewriter cam operation to rotate the engaged keys and thereby rotate the shafts associated with the said keys. The particular keys and shafts rotated upon displacement of the selected selectors depends upon the permutation code selected. The reason for alternating the positions of the studs 35 will now be understood,

on other selectors are not engaged by the associated keys fixed on the rotated shafts.

It is preferred when the selectors described are used in conjunction with the Electromatic typewriter, that the studded sections are alternately arranged to be positioned above and below the permutation bars, respectively, due to the close spacing of the typewriter cam members; therefore, in accordance with this arrangement, it will be seen that the front typewriter cams displace selectors 32 which are arranged so that the studs thereof engage the keys extending below the bars 33 to rotate the said keys and associated shafts in a counterclockwise direction, and that the rear typewriter cams displace the selectors 32 which are arranged so that the studs thereof engage the keys extending above the bars 33 to rotate the said keys and associated shafts in a counterclockwise direction. Upon displacement of the associated shafts and selectors provision is made to return them to the normal inoperative position by means of springs it attached to the bars 33 and posts 59 mounted on the end plates 39 and the springs 50 interconnecting the adjacent selectors 32.

Attached to each end plate 33 is a switch unit comprising three individual switches which may be of the single pole, double throw type. The switch arms 52 are pivoted at 53 and are normally in position to engage contacts 53. The arms 52 are provided with insulating heads 55 and are engaged by keys 56 (similar to keys 3 3) depending from the shafts 36 so that normally the switch arms are positioned against the tension of springs 51 which are attached to the switch arms and the housing of the switch unit 5i to engage the contacts 5 3; however, upon rotation of the bars 33 in a counterclockwise direction the keys 5? also are rotated in a' similar direction, thereby permitting the springs 57 to rotate the switch arms 52 in a clockwise direction so that contacts 58 are engaged by said arms. The tensions of springs #33 are greater than the tensions of springs 51, therefore, when the bars 33 are returned to normal position by the associated springs, the keys 56 return the switch arms 52 to the normal position described to engage contacts 55.

Referring now to Fig. 4, one of the front cams ii is shown in an operated position and let it be assumed due to the depression of a certain keybar. The displacement of the bell crank lever l2-a causes the cam roller 3i on extension arms 3t to displace the selector 32 to the right and thereby engaging and displacing the keys 34 attached t'o permutation bars 33 Nos. 2, 3, 4, and 5, causing the shafts to be rotated in a counterclockwise direction and releasing the corresponding switch arms 52 to engage the associated contacts 58.

In Fig. 5, one of the rear cams ii is shown in an operated position due to depression of the keybar corresponding to a difierent character, to displace the selector 32 to the left engaging and rotating in a counterclockwise direction the keys 36 fixed to the permutation bars 33 Nos. 2, 3, and 4 to release theassociated switch arms 52 to engage the contacts 53.

In this manner, combinations of signal conditions may be initiated in accordance with the chosen permutation code and due to the operation of the associated keybars not only are the associated permutation bars displaced by the power operated units but the latter are also effective to operate the corresponding typebars to efiect recording of the characters corresponding to the character signal conditions represented by the operated permutation bars. The linkages operating the typebars have not been altered, so that when the machine is not conditioned for transmitting purposes the operation of the keys cause the typebars to be operated in a'normal manner. The means for conditioning the machine will be described hereinafter, however, it is noted that the signal conditioning means or the contacts operated by the permutation bars. must be disconnected from the transmission me dium because upon any operation of the keybars and the power operated units the selectors and described permutation bars are always operated, that is, upon operating the machine as a standard typewriter-or as a receiver unit the said described unit is operated.

The permutation unit adapted to be controlled by the conditioned transmission medium will now be explained. This said unit is associated with the operable keybars of the machine and is adapted to select and operate the keybars to operate the common power operated units and typebars which are operated when the machine is conditioned for signal transmitting purposes or for standard typewriting purposes.

Referring now to Figs. 12 to 20 and 22, the said unit is shown to comprise generally a plurality of round slotted shafts or bars 60, the slots 6! of which are arranged diametrically opposite one another. The said bars are normally maintained inoperative so that the control levers 62, one for each key bar and attached thereto, by link 63, are locked in an inoperative position. Gear units 64 (Fig; 14) are provided at each end of the permutation bar device, comprising three sets of gears, one for each shaft or bar 60. The gears 65, 66 and 61 are rotated continuously by drive gears 68 and are connected to the associated bars 60 by individual clutches 69 (Fig. 15) to drive said bars one revolution. The clutches 69 are controlled by magnets 10 which are energized by control signals and in combinations in accordance with the preferred permutation code. During the rotation of the selected bars 69 certain slots 6| disposed thereon are presented under the control lever 62 so that one control lever is selected and permitted to drop in the channel provided by the slots which are in alinement, operating the control lever and its attached keybar lever, thus causing the character to be recorded.

The permutation bars 60, of which six are shown, are supported in the end plates 1| (see Fig. 12) attached to the gear units 64 which are secured to the supporting casting indicated generally at 12. To prevent sagging of the bars, central supporting posts 13 are'provided. The control levers 62 are positioned over the permutation bars 68 (Fig. 13), and are pivotally supported at the ends thereof by rod 14 suitably supported by members 15 attached to the supporting casting 12. Individual springs 16 are attached to the levers 62 to urge the levers against the permutation bars 60. The lever 62 at the other ends thereof are linked to the keybar by connecting links 63, and therefore it will be seen that upon depression of a control lever 62 by spring 16 the link 63 will be moved downwardly to lower the attached keybar and causing the associated power operated unit and typebar to be operated. The levers 62 are kept in correct alinement by means of the comb member 11 attached to the said supporting casting.

2,181,940 The entire supporting casting 12 is pivotally upon rotation of certain of the bars, one control lever 62 is selected and permitted momentarily to be depressed into the slots by spring 16 thereby depressing the attached link 63 and keybar 11. Referring to Fig. 13, it will be seen that the rotation of bars 60 Nos. 2, 4, and 6, will cause the slots of all the bars to be alined under the particular control lever 62 shown, thereby permitting said lever to be lowered into the slots momentarily to depress the associated link and keybar, causing the corresponding typebar to be operated.

The bars are rotated as follows: the power driven roller 18 of the typewriter is adapted to rotate the shaft 88 by means of the connecting belt 8|. Attached to said shaft is a pair of driving gears 68, the gears positioned so as to engage the gears 66 (Fig. 14) in each gear unit 64. The gears 66 are adapted to rotate the gears 65 and 61. Each of the gears, 65, 66 and 61, is attached to individual stud shafts 82 (Fig. 15) upon which are mounted ratchet gears 83. Associated with each ratchet gear 83 is a clutch unit 69 which is secured to the permutation bar 68. A clutch unit is provided for each bar. The principle of operation of the sets of clutch units and gear units are identical and consequently only one set need be explained. It will be seen from Fig. 14 that the directions of motions of the clutch gears 65, 66 and 61 are different, and because of this fact the clutches 69' are made right-hand and left-hand to correspond thereto.

A controlling magnet 10 is provided for each clutch 69. Referring to Figs. 12 and 15, the magnet 10 is provided with an armature 84 secured to a clutch stop arm 85. The said arm, while the magnet 18 is deenergi'zed, is adapted to engage the dog lift lever 86 which maintains the dog 81 in the position-shown in the figure to prevent engagement of ,the tooth. 88 on the dog and the ratchet gear 83. I

The cluch is shown to comprise (see Figs. 16 to 18) a housing member 89 secured to the permutation bar 68. The member 89 is shaped so as to receive the toothed dog 81. A spring post 96 is fixed in the said member 89 and acts as a guide for spring 91. The dog 81 is shaped so as to fit over the said spring and spring po 'st and when mounted in the channel provided in the housing'member 89 it is seen that the spring 9| tends to urge or maintain the dog 81 to the right as viewed in Fig. 17. The dog 81 and housing member 89 are recessed so as to receive the dog lift lever 86 which when inserted in the housing member is adapted to be rotated slightly or pivoted about one end thereof. The other end of the dog lift extends beyond the housing member and is arranged to engage the stop arm 85 whenever magnet 10 is deenergized. Movement of the dog lift lever 86 moves the recessed dog 81 and when blocked by the stop arm 85 as shown in Fig. 15 positions the dog 81 to the extreme left hand position against the action of spring 91. A spring-pressed stop 92 engages a notch 93 provided in the housing member 89, preventing the bar 60 to be rotated in a clockwise direction as viewed in the figure, thereby locking the clutch unit so long as the magnet remains deenergized.

Upon energization of the magnet, its armature 84 is attracted and positioning thestop arm 85 downwardly about the pivot 94 out of engagement and the path of dog lift lever 86. The spring 9| thenforces the dog 81 to the right as viewed in Fig. 15 into engagement with the constantly rotating ratchet gear 83.

The signal condition impressed upon the magnet lasts momentarily, so that the stop 85 is positioned in the path of the dog lift lever 86 before one revolution of the clutch has been completed. As the clutch is rotated by the gear 83 and completes its revolution the dog lift lever engages the stop 85, and as the clutch continues its rotation with the lift lever 86 held stationary by the stop 85, the said lift lever is rotated about its end positioned in the housing member 89 to slide the toothed dog 81 out-of engagement with the ratchet gear 83. When the tooth 88 is brought out of engagement with the said ratchet, drivingpower is removed from the clutch and permutation bar. The spring 9| within the dog 81 normally would have a tendency to rotate the permutation bar in a reverse direction and permit the tooth 84 to again engage the ratchet gear; however, as previously explained the clutch and bar 60 are locked in the inoperative position by means of the stop 92. Due to the relative high speed of operation, when the toothed dog is forced out of engagement with the ratchet by means of the stop 85, the momentum of the rotating permutation bar and clutch is sufficient to rotate the bar and clutch slightly beyond the position where the tooth 88 just becomes disengaged from the ratchet gear; this carry-over is sufiicient to permit the spring-pressed stop 92 to engage the notch 93 locking the clutch and bar against reversed rotation and insuring sufiicient clearance between the dog tooth and the ratchet so as to prevent chattering.

The remaining permutation bars are rotated in a like manner upon energization of the associated clutch magnets 70. The magnets are energized practically simultaneously so that when a. particular combination of signals causes certain of the magnets to be energized, the corresponding permutation bars are permitted to be rotated one revolution, permitting one control lever $2 to drop in the alined slots on the permutation bars, thereby recording a character on the power operated typewriter accordingly.

The design of the permutation bar unit should be such that the stroke of the lever 62 is about twice as great as necessary to operate the typewriter keybar. In this manner the clutches are permitted a wide margin of operation and provides suificient tolerance to allow for variations intiming of the difierent magnets due to variations in time of arrival of the signals. With reference to Fig. 13, it is seen that when the permutation bars 2, 4, and 6 rotate one revolution, the first 90 thereof the levers 62 are all maintained in a locked position, the next 90 permits the selected lever to be pulled downwardly by spring 16, the next 90 locks up all the levers again and during the last 90 the bars are positioned as shown in the normal position. It is seen,

therefore, that upon reception of a signal the bars are rotated, but even in this event all the control levers are maintained in a locked position except the selected one, in this manner making it impossible to depress more than one control lever and its associated keybar at a time.

It should be mentioned that the keybars ll are each provided with an elongated slot 95 so positioned that the connecting pin 95 secured to link 63 is efiective to cause depression of the keybar when the control lever 62 is lowered into the aligned slots in the permutation bars. This said slot also permits the keybars H to be depressed manually without disturbing the link 63 and lever 62, to efiect operation of the power operated units and corresponding typebars. In the described manner the machine can be conditioned not to be operated by the conditioned transmission medium yet be operated manually as a standard typing unit. The description thus far dealt with the mechanical elements of the machine and their arrangement so that the machine can be operated as a transmitting unit, a receiving unit, and a standard typing unit.

By referring now to Fig. 21, the transmission medium conditioning contacts and the conditioned magnets are shown connected in one type of known printing telegraph circuit, which need only be briefly described, since the circuit per se is not claimed as part of the present invention.

The signal conditioning means are operated by the contacts 58 in the figure and correspond to the contacts conditioned by the transmitting permutation bars. These contacts are shown to control individual high frequency generators or oscillators F-i to F-5; the frequencies or oscillations of which difiering with respect to each other. The output of the said generators are connected to suitable filtering devices indicated at M-l to lVi'-5, each device adapted to pass only the oscillations generated by the associated generator. The filtering devices are connected to a common conducting channel 9i terminating at the contacts 98 of a switching device 99. The common contacts of the said switch are connected to an amplifier system connecting to the transmission medium'indicated by the line associated therevn'th.

It is now seen with the switching device 99 operated in the T position to engage the contacts $8, the transmitting system is conditioned so that upon operation of the transmitting control contacts 58, the associated transmission medium is conditioned accordingly. With the switch 99 in the position shown in the said figure the machine is conditioned for ordinary typing purposes. The keybars can then be operated manually to efiect recording-of the characters in a normal manner, without afiecting the line, that is, the transmitting mechanism is not effective to condition the associated transmission medium. One method of conditioning the transmission medium for controlling a remote station has been shown and described, now let it be assumed that the medium is being conditioned by the said remote station in a manner just described to operate the mechanism shown in the figure as a receiving unit.

The switching device 89 which may form a part of the machine proper, and suitably attached to the frame thereof, is now positioned in the R. position to engage the contacts I80. A com mon channel "ii is connected to the contacts I88 and also connected to the individual filtering devices RM-I to RM-G adapted to pass only the individual oscillations generated by the generators F-.-I to F-6. The individual filtering devices ar connected to the control magnets I which controlthe operation of the receiving permutation bar unit. Therefore, it is seen that the magnets 10 are conditioned in accordance with the conditioned medium to control the permutation bar unit accordingly to select the corresponding keybars which in turn then operate the common power operated units and typebars.

Additional contacts C--l to C6 are shown in the circuits between the transmitting contacts and the oscillation generators which can be adapted to be operated by the switch 99 or individually to open the generator circuits whenever the machine is conditioned for receiving the signals or for ordinary typing. In certain installations this may be desirable, whereas in certain types of systems these contacts are not necessary.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it

. be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is as follows:

1. A machine of the class described having a rotary power driven roll, signal transmitting means comprising a plurality of key bars and cam operated units, one for each key bar, individual means controlled by each key bar, upon operation thereof, for operating the corresponding cam unit by the said roll and signaling means controlled by the operated cam unit, and signal receiving means comprising a plurality of rotatable selector bars having means .for controlling the operation of the key bars, connecting means driven by the said roll for rotating the said bars, and means for controlling the selection of the bars to be rotated by the said connecting means.

2. The machine described in claim 1 wherein a plurality of type bars are provided, one for each key bar, and additional individual means controlled by each key bar, upon operation thereof, for operating the corresponding type bar.

CLYDE J. FITCH. KURT R. SCHNEIDER.

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