US2160919A - High speed recording system - Google Patents

Description

June 6, 1939. H. o. STORM HIGH SPEED RECORDING SYSTEM 2 Sheets- Sheet 1 Filed July 27, 1938 OSCILLATOR //0 v. .4-c. a/va OSCILLATGR a.

INVENTORT HANS 0. sro/m POSITIVE i/OLTA L ljo/vs SIGNAL FRoMREcE/VEk A TTORNEYS.

June 6, 1939; H. o. STORM HIGH SPEED RECORDING SYSTEM Filed July 27, 1938 2 Sheets-Sheet 2 IMPEDANCE MATCH 1N VEN TOR HANS O. STORM.

A TTORN E YS.

Patented June 6, 1939 1 UNITED STATES PATENT OFFICE 2,160,919 HIGH SPEED RECORDING SYSTEM Hans 0. Storm, Palo Alto, Calif., assignor to Globe Wireless Ltd., San Francisco, Calif., a corporation of Nevada My invention relates to the art of recordin and transcribing telegraphic messages with the aid of phonographic records.

Among the objects of my 5 provide a means and method of recording and transcribing high speed telegraphic messages; to provide a means and method of isolating message blocks on a plurality of separate phonograph records, whereby a plurality of transcribers can transcribe complete messages; to provide a system of ,phonographically recording high speed telegraph messages'on separate records, in such a manner that the transcriber of such messages will be able to transcribe a group of complete messages from any single record; to provide a means and method of recording a group of complete telegraphic messages on a single record durin continuous reception of messages; to provide a means and method of avoiding split messages in the recording and transcribing of high speed telegraph signals; to provide a means and method of automatically inserting on the record of continuous high speed telegraph signals an additional signal denoting the end of the last complete message on each individual record; and to provide a simple, automatic high speed telegraph signal recorder, wherein split messages are avoided.

My invention possesses numerous other objects and features of advantage, some of which, to-

gether with the foregoing, will be set forth in the following description of specific apparatus embodying and utilizing my novel method. It is therefore to be understood that my method is applicable to other apparatus, and that I do not limit myself, in any Way, to the apparatus of the present application, as I may adopt various other apparatus embodiments, utilizing the method, within the scope of the appended claims.

Referring to the drawings:

Fig. l is a Wiring diagram of a portion of a preferred form of high speed recorder of my invention, this portion comprising the final signal amplifier and the relay board, the output circuits of the relay board being continued in registering circuit lines to Fig. 2, which is a diagram of a preferred form of recorder unit.

In order that my invention may be more fully understood, I intend to describe the circuits of the receiving system as shown in the drawings, and thereafter describe the operation of these circuits as a whole.

Referring, therefore, to Fig. l, the tone signal from a radio receiver is transmitted over signal line I to push-pull transformer Z and thence to invention are: To

push-pull vacuum tube 3, the output of which energizes a rectifier transformer 4 which in turn energizes a full wave rectifier tube 5. Grid bias 1 is provided by negative voltage line 6 and the plate potential for the tubes is provided by positive voltage connection I.

The output from rectifier tube 5 is taken through the cathode side of ground and passes, by means of output wire 9, through the windings Ill of control relay II, and the output circuit is continued by combining output wire 9 with ground line I2 to keying relayG within the control panel, as designated by dash line 14. Thus, it will be seen that control relay H. and keying relay G are in series between the ground and the cathode of rectifier tube 5, the relay H and relay G comprising the entire circuit through which the output of rectifier tube 5 passes. It will be obvious that both relay II and relay G are of the high speed type, capable of responding to telegraph signals on the order of one hundred words per minute.

In order to carry through the signal circuit to the end, I will follow the action of keying relay G. A separate oscillator #2 is provided for the purpose of supplying to relay G a signal of a frequency which is well adapted for recording, irrespective of the frequency of the tone signal from the receiver. The output from oscillator #2 is carried through signal circuit l5 and through adjustable resistor It to a stationary contact I! on relay G, in the path of armature I8 thereon.

The output of oscillator #2, after control by relay G, passes into a recorder circuit 20 leading to stationary contacts 2| on relay A registering with moving contacts 22 on the same relay, the output of these two moving contacts passing through the continued signal circuit 20 directly into the usual impedance matching network 24, shown on Fig. 2. The output of the impedance network connects to parallel recording cutters 25 and 26, each mounted on its own turntable 2! and 28, respectively, on which record units maybe placed.

A back contact IS on relay G is connected to one side of circuit i5 and grounded. Thus, when relay G becomes de-energized, contact between armature I8 of the relay and the back contact 19 is effected, and the signal output circuit 20 becomes completely shorted and grounded at the shorting point. Such action will occur during spaces in the code, and so prevent transference of energy between the contacts I! and I8 and alongother stray capacitance paths.

While I have symbolically shown the cutters and 26 and turntables 2'! and 28 as of the disc record. variety, it will be obvious that the type of recording is immaterial to the practice of my invention. Any type of recorder wherein the records themselves are in removable units will be satisfactory, and in practice the cylinder type of recorder gives identical results.

One other source of energy is supplied to cutters 25 and 2E. The output of oscillator #1, which is an oscillator giving a distinctive tone signal entirely different from either the tone signal from the receiver or that from oscillator #2, is led through an output circuit 36 from oscillator #1 to a pair of stationary contacts 3! opposed to signal contacts 25 and in position to be contacted by moving contacts 22, all in relay A. Thus, the operation of relay A will deliver to cutters 25 and 26 either the signals coming through keying relay G from oscillator #2, or an entirely difierent tone signal from oscillator #1.

I have thus described all the circuits having to do with the recorded impulses, and I will now return to control relay ii for the action of the control circuit. This circuit is entirely separate from the signal circuits, and the'opposite sides of the relay will be traced separately.

The stationary contact 59 of relay ii is supplied with constant positive D. C. voltage through jumper 5? and wire 58. On operation of the relay ll" coded direct current is supplied from the contact 59 to the armature, thence through Wire 32 to the coil of relay F, which is of the damped type, with a heavy short-circuited winding 3 3, so that it remains energized with its contacts open during the passage of coded messages,

but which will close only when code is not being carried on the line, such as, for example, the time space between message blocks. After passing through relay F, the current returns through the common negative wire to negative side 55 of the power supply.

Control relays B and C are similar in their action and are energized in response to operation of the recording apparatus shown in Fig. 2. The circuit of relay B can be traced from Pos. DC In at 56 through line 50 by way of closed contact 5!66 at relay F, through cam contacts i241 operated by position of cutter 26, to switch M, then by way of line 5G through the operating coil 35 of the relay B, to the negative side of the D. C. supply source. Upon energization of this relay, contact will be established between its stationary contact Bi and its movable contact B5 to close a holding circuit for the relay. This holding circuit includes the line H3 and the relay contacts Bi and B5, the contact B5 being connected to the positive side of the D. C. supply source. shunts the cam contacts 42-4! and the contact 5|66 at relay F, so that regardless of any'subsequent opening of the original energizing circuit of relay B at either of these two points, the holding circuit will maintain relay B in energized condition. a

As regards relay C, its energizing circuit may be traced from the Pos. DC In side of the D. C. supply source through the contact 5l-55 at relay F and the cam contacts A i-48, operated by position of cutter 25, by way of line 5%, and through control switch 88, line 89 and relay coil 54 to the negative side of the D. C. supply source.

Upon energization of this coil 56, contact will be made between the stationary contact 4C of relay C and its associated movable contact C! This portion of the holding circuit to establish a holding circuit which will shunt the contact iii-68 at relay F and the cam contacts i i-4B of the original energizing circuit for relay C, to maintain relay C energized in spite of any opening of the original energizing circuit at either relay F or at the cam contacts ti l-48. The portion of the holding circuit shunting the above mentioned contacts 5l66 and idit may be traced from the switch 8'! to line H, through the relay contacts C4 and 7 Cl to the positive side of the D. C. supply source.

Relay D of the system having operating winding 35 is of the slow acting type, such as relay F previously described, and is accordingly pro vided with a damping winding 3?. This relay is energized through normally closed contacts B3B 5 of relay B, which contacts connect the positive side of the D. C. source directly to one end of the relay winding 33, whereas the other end of this winding is directly connected to the negative side of the D. C. supply source.

Upon energization of this relay, its associated contacts tii-fi i will close, and upon the deenergization of the aforementioned relay B, the making of contact between relay B contacts B2 and B5 will complete an energizing circuit through winding 38 of relay A. Although upon the de-energization of relay B, the energizing circuit through relay D will be broken at contacts B3-B5, the relay D contacts 66-64 will momentarily maintain their contact with each other due to the slow releasing characteristic of this relay, and thus permit establishment of the energizing circuit to relay A. However, such energization of relay A will continue only momentarily, for relay D will soon de-energize itself sufiiciently to release its armature and permit separation of its associated contacts 68-65.

A similar sequence of operations occurs with respect to relays C, E and A, as has just been described in connection with relays B, D and A. Relay E is of the same type as relay D and becomes energized through normally closed contacts C2C6 of the afore-mentioned relay C. Upon de-enerQgization of relay C, the connection between the contacts C2C6 will be broken and contact will result between its contacts C3 and C6, thus establishing an energizing circuit through the coil 38 of relay A, it being noted that in spite of the opening of the energizing circuit to winding 52 of relay E at C2-C5, the contacts 65 and 61 of this relay will'momentarily remain in contact long enough to enable energization of relay A, but as was previously explained in connection with the operation of relay D, the energization of relay A will only be momentary, for contacts 65-6l associated with relay E will soon separate.

It will be noted, therefore, that relay A can be momentarily energized either through the cooperation of relays B and D or through the colines 243 and connect the output of oscillator #1 by way of lines to this signal circuit 20 in place of oscillator #2, which it should be recalled was connected to the signal circuit 28 through operation of the keying relay G in response to incoming signals for recording. The switch from oscillator #2 to oscillator #1 will continue only so long as relay A remains energized, and since, as has been previously explained, relay A will remain energized momentarily only, it follows that the output of oscillator #1 will be impressed upon the signal circuit 28 for only a very brief period.

Coming back to the relay B and relay C, it is noted that relay B embodies a pair of normally opened contacts B4-B1, and relay C embodies a similar pair of normally opened contacts C|C5. The closing of these contacts in response to the energization of their associated relay windings, serves to establish an alternating current circuit to energize motors 15 and 18 which in turn drive the turntables 28 and 21 respectively of the recording apparatus of Fig. 2. The circuit to the motor 15, for example, as established by the closing of contacts B1-B4, may be traced from "110 V A-C In at 8| through relay B contacts B1B4 to switch 14 by way of line 12, through the motor 15 and back tothe grounded side of the A. 0. supply source by way of line 82.

Similarly, with respect to the motor 18, the circuit may be traced from the 110 V A-C In side of the line through relay C contacts C5-C| to motor switch 11 by way of line 16, through motor 18 and back to the grounded side of the A. C: supply source by way of line 82.

The positive D. 0. line 56, after passing through jumper 51, passes through another jumper 83 and thence to motor switch common wire 84, which divides and goes to stationary contacts 85 and 86 on the left motor switch 4| and right motor switch 81, respectively. The opposite contact 88 on motor switch 81 returns via line 98 to winding 54 on relay C, and the opposite contact 89 on motor switch 4| similarly returns via line 4|] to the winding 35 on relay B.

Each of the motor control switches 4| and 81 comprises two independently operable pivoted arms. Referring to the switch 4|, the upper arm, as viewed in Fig. 2, is normally maintained in contacting engagement with contact 89, but the contact at this point is capable of being broken manually by swinging this arm out of engagement with the contact 89. The lower arm of the switch is adapted to be swung into and out of engagement with the contact 85, and similarly, with respect to the switch 81, its lower arm is adaptable for making and breaking connection with the contact 88 and is normally in contact making position, whereas the upper arm, as viewed in Fig. 2, is capable of being urged into or out of engagement with the contact 86.

With both arms of switch 4| in contact with their associated contacts 85 and 89, the relay B will be energized through a circuit which can be traced from the positive side of the D. 0. supply source through jumpers 51 and 83, to line 84 which conveys the energizing current to the contact 85 where it passes through both arms of the switch 4| to line 48, which in turn conveys it to the winding 35 of the relay B. Through energization of this relay B, as was previously explained, the contacts B4 and B1 will close, conmeeting the motor 15 to the alternating current supply source BI and 82.

Thus, in starting up the apparatus, the relay B will be energized through the closing of both contacts of the control switch 4| but in the running position relay B is energized through the contacts B|--B5 and the switch contact at 89, as has previously been explained. When it is desired to shut down or stop operation of motor 15, it is only necessary to open the contacts of the switch 4|.

In a similar manner, with both arms of switch 81 making contact with contacts 88 and 88, the relay C will become energized and connect the A. C. supply source to the motor 18 to start its operation, and during operation of the recorder, relay C will be energized through contacts C4-C1 and switch contact at 88, as was previously ex plained. Likewise, when it is desired to halt operation of this motor, this can very readily be done by opening the contacts of the switch 81.

After having described the complete circuit set-up, I will now describe the performance of the system, and why such performance is desirable. I

In the recording of high speed telegraph signals on phonograph records in units, the code telegraph signals are received at high speed and recorded, and thereafter the individual records are distributed among as many transcribing operators as are required to keep up with the rate of transmission. The recording units are alternately operated in such a way that continuous recording with a small overlap may be secured for as long a period as desired. Such a program alone, however, is not satisfactory for the handling of telegraph messages, because even though the recording of the two machines, which are alternately used overlaps a suliicient amount so that all of the material is eventually available for transcription, in most cases the last message on every record will be broken off and resumed upon the succeeding record. Consequently, if record units are distributed to a plurality of transcribing operators immediately upon completion of a high speed record, one of the transcribing operators, when he gets to the end of a record, will encounter a split message,the latter part of which will be on a record which is already in the hands of a second operator, causing confusion in getting the split message back together again. Even should a long enough period of overlap be allowed so that a negligible number of messages are split, the confusion will still obtain, because an operator will not know definitely where to stop copying to avoid duplicating a message being copied by another operator.

Broadly, the performance of the above described apparatus is as follows: The high speed copy at the sending station is punched out, usually on tape, in blocks consisting of one message each, although it will be obvious that if the messages are short they can be in blocks, each block carrying a plurality of messages. Within each block of trafiic no long spaces are permitted, but between every block, for example, there is left a long space equivalent to five or ten letters of the code, during which no characters of any kind are sent out at the transmitter.

At the receiving set the two recording machines are provided with their recording heads or cutters, always connected in parallel to the incoming high speed signal. Qne of these recorders is started by the operator at the beginning of correspondence, and the second machine is loaded with a record butis standing idle, ready to go. The first machine commences recording and cuts one block of traffic after another without any change, until a predetermined part of the record, for example, two-thirds thereof, has been used up. At the end of the next block of trafllc after that predetermined amount has been traversed, the second machine will be started. The first machine will continue to run, but a characteristic warning signal, distinct from the received telegraph signal, will be imprinted or cut on the first record, to advise the operator who transcribes that first record that under normal conditions he has finished copying and may leave the remainder of the text on that record.

The recording continues on the second recorder until the required two-thirds of the second record has been used up, after which, at the next termination of a block of traffic, the process is reversed and machine #1 is again started, while the warning signal is imprinted on the record in machine #2. It is assumed that during the interval an attendant has removed the full record from machine #1 and inserted a blank, and at the same time has returned the cutter to the starting point.

The last third of each record, minus the recorded portion up to the end of the final block to be transcribed, is used as an overlap in case the attendant is tardy in record changing or fails to set back the carriage, in which case the first message on the record might be lost. If the record were stopped when the alternate record is started, it might be necessary to refer back to the sending station in case of a delayed start of the following record.

This is the broad performance of the device. The operation of the device is simple, and I will now refer again to the described wiring diagram. As before stated, the signals pass through the one stage of push-pull amplification and the rectifier stage 5, and leave tube 5 as a pulsating direct current passing through control relay l l and keying relay G. The relay G transfers the signal onto the cutters as a separate and distinct tone from oscillator #2. At the same time, control relay H impresses the signals on relay F, which relay, being of the damped type, remains energized with its contact open during the time that code messages are being transmitted, but is completely de-energized and permits its contact to be closed only during the long spaces between the blocks of traffic, as above referred to.

Cams ill and 38 on the carriage of each recording machine are responsive to cutter position, and close contacts 42 and 45, 44 and 46, and maintain them closed during the latter one-third or predetermined portion of the travel of the cutters over the records. Energy to these cam contacts is supplied only during the blank space between traific blocks, as determined by relay F. An output from these contacts obtains, therefore, only when a space between messages occurs after the record has been two-thirds used up. Cams 4i and :38, through the normally closed contacts of the motor switches M and 81, operate the coils of corresponding relays B and C, each of which, once closed, is held closed by the holding contacts Bi and C4. Relays B and C govern, respectively, the motors of the right and left machines, as shown in the detailed description of the circuits to these relays.

In addition, however, it will be seen that, for example, relay B, in its de-energized position, gives energy through contacts B3 and B6 to relay D, which will therefore be closed. When, however, relay B operates during the transfer of records, it will give energy to contact 64 of relay D through closing of contacts B6 and B2, and at the same time the coil 36 of relay D will be de-energized. Relay D, therefore, which is of the slow return type similar to relay F, will only pass current momentarily through its contacts, and after an interval of a fraction of a second will again be released. This results in momentary operation of relay A, due to the transfer of records in either direction. The momentary operation of relay A disconnects the recording heads from the incoming signal and connects them for a short period to the alarm signal, of a different frequency from oscillator #1.

The same condition exists, as just above described, for relay in conjunction with relay E operating alarm relay A, so that when the shift is made from one record to the other in either direction, the alarm is impressed on both records. The manual motor switches 4i and 81 are only used to start and stop the operation of motors l and 18. During the running period of the apparatus, the shift from one recorder to the other is automatic when a blank space occurs between blocks after approximately the desired portion of any record has been out.

It will also be noticed that the received signal is converted by relay G into a signal from a local oscillator of fixed frequency, i. e., oscillator #2. This is done for several reasons. It removes background noise from the signal imprinted on the record, and it permits pitch, volume and harmonic content of the imprinted signal to be adjusted to an optimum value, which is not always possible with the radio signal direct. For example, in order to obtain a pitch which is not too low for transcribing, the recording pitch should be somewhat higher than can easily be maintained in a receiver output, and transmitted over telephone lines such as are commonly used in remote reception of radio signals.

It is to be noted that while I have described my invention as related to disc or cylinder records, that records consisting of belt-shaped endless strips may be utilized. In the latter case, there might be difficulty in devising suitable cams, such as have been described herein, and consequently it must be distinctly understood that a time operated device, not mechanically connected to the recorder carriage or movable element thereof, could be used in place of the cams, inasmuch as records of all types run at a constant predetermined speed and consequently take a definite time between beginning and end. A synchronized timing element, therefore, is deemed to be fully equivalent of the positively connected cams, as described.

Furthermore, while I have described my invention as related to the recording of high speed radio traffic, it will of course be obvious that it is also equally applicable to high speed signals on wire lines.

I claim:

1. In a telegraph system, the method of recording high speed message signals on a plurality of separate moving units comprising dividing the messages into blocks at the transmitter by omitting signals therebetween for a predetermined length of time, receiving said signals, recording said signals on one of said units, partially completing a circuit by movement of said unit after a predetermined amount thereof has been used for recording, thereafter utilizing the change of current between message blocks to complete said circuit, and utilizing the completed circuit to shift recording to another unit.

2. In a telegraph system, the method of recording high speed message signals on a plurality of separate moving units comprising dividing'the messages into blocks at the transmitter by omitting signals therebetween for a predetermined length of time, receiving said signals, recording current between message blocks to complete said said signals on one of said units, partially completing a circuit by movement of said unit after a predetermined amount thereof has been used for recording, thereafter utilizing the change of circuit, utilizing the completed circuit to shift recording. to another unit, and automatically recording on the first unit a signal distinct from said prior recorded signal simultaneously with the shift to said next unit. I

3. In a telegraph system, the method of recording high speed message signals on a plurality of separate moving units comprising dividing the messages into blocks at the transmitter by omitting signals therebetween for a predetermined length of time, receiving said signals, recording said signals on one of said units, partially completing a circuit by movement of said unit after a predetermined amount thereof has been used for recording, thereafter utilizing the change of current between message blocks to complete said circuit, utilizing the completed circuit to shift recording to another unit, automatically recording on the first unit a signal distinct from said prior recorded signal simultaneously with the shift to said next unit, and continuing recording on both units until the entire recording space has been used on said first unit.

4. In a telegraph system, the method of recording high speed message signals on a plurality of separate moving units comprising dividing the messages into blocks at the transmitter by omitting signals therebetween for a predetermined length of time, receiving said signals, recording said signals on one of said units, partially completing a circuit by movement of said unit after a predetermined amount thereof has been used for recording, thereafter utilizing the change of current between message blocks to complete said circuit, utilizing the completed circuit to shift recording to another unit, automatically recording on the first unit a signal distinct from said prior recorded signal simultaneously with the shift to said next unit, continuing recording on both units until the entire recording space has been used on said first unit, removing said first unit, transcribing said recorded messages therefrom, and utilizing said distinct signal as a Warning to cease transcription.

5. Method as recited in claim 1, wherein the received signal energy is utilized to key a separate train of signals better adapted to recording than said received signals.

6. In a telegraph system, means for recording high speed message signals comprising means for dividing traffic messages into groups at the transmitter leaving spaces devoid of signals for a predetermined time therebetween, means for receiving said signals, a pair of recording machines each driving a recording unit and having a recording device operable on said unit to record signals thereon, means for energizing both of said recording devices in accordance with said signals, means for starting one of said machines to start recording, means responsive to the change in current occurring between said message groups for setting up a change-over circuit, means responsive to the position of said recording device on said recording unit being operated for completing the set up change-over circuit, and means I for utilizing said completed change over circuit to start the other recording machine.

7. In a telegraph system, means for recording high speed message signals comprising means for dividing traffic messages into groups at the transmitter leaving spaces devoid of signals for a predetermined time therebetween, means for receiving said signals, a pair of recording machines each driving a recording unit and having a recording device operable on said unit to record signals thereon, means for energizing both of said recording devices in accordance with said signals, means for starting one of said'machines to start recording, means responsive to the change in current occurring between said message groups for setting up a change-over circuit, means responsive to the position of said recording device said recording unit being operated for completing the set up change-over circuit, means for utilizing said completed change-over circuit to start the other recording machine, and means for stopping said first started machine at the end of the permissible recording time.

8. Apparatus in accordance with claim 6, wherein means are provided for the change-over circuit to be completed only in a final predetermined portion of the permissible recording time.

9. Apparatus in accordance with claim 6, wherein means are provided for recording an auxiliary signal on said operating recording unit at the time of change-over.

10. In a telegraph system, means for recording high speed message signals comprising means for dividing traffic messages into groups at the transmitter leaving spaces devoid of signals for a predetermined time therebetween, means for receiving said signals, a pair of recording machines each driving a recording unit and having a recording device operable on said unit to record signals thereon, means for energizing both of said recording devices in accordance with said signals, means for starting one of said machines to start recording, a pair of recording machine relays controlled by said starting means,

a circuit make and break means operating in synchronism with the recording machine and operable only after a predetermined amount of recording time has elapsed, a damped relay responsive to the change in current occurring between said message groups, and a connection between said make and break means and said damped relay to operate one of said recording machine relays to start the other of said machines.

11. In a telegraph system, means for recording high speed message signals comprising means for dividing trafiic messages into groups at the transmitter leaving spaces devoid of signals for a predetermined time therebetween, means for receiving said signals, a pair of recording machines each driving a recording unit and having a recording device operable on said unit to record signals thereon, means for energizing both of said recording devices in accordance with said signals, means for starting one of said machines to start recording, a pair of recording machine relays controlled by said starting means, a circuit make and break means operating in synchronism with the recording machine and operable only after a predetermined amount of recording time has elapsed, a damped relay responsive to the change in current occurring between said message groups, a connection between said make and break means and said damped relay to operate one of said recording machine relays to start the other of said machines, and means operated by either of said recording machine relays when operated to divert an auxiliary signal of limited length to said recording devices.

12. In a telegraph system, means for recording high speed message signals comprising means relays controlled by said starting means, a circuit make and break means operating in synchronism with the recording machine and operable only after a predetermined amount of recording time has elapsed, a damped relay responsive to the change in current occurring between said message groups, a connection between said make and break means and said damped relay to operate one of said recording machine relays to start the other of said machines, and means operated by either of said recording machine relays when operated to divert an auxiliary signal of limited length to said recording devices, said auxiliary signal being limited to a time less than the time between message groups.

HANS O. STORM.

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