US2543531A - Counting apparatus - Google Patents

Description

Feb. 27, 1951 w. Y. LANG 2,543,531

COUNTING APPARATUS Filed Feb. 19, 1948 I FIG. 2

INVENTOR M. K LANG aww A T TOR/VEV Patented Feb. 27, 1951 COUNTING APPARATUS Wilmarth Y. Lang, Towaco, N. J., assignor to Bell Teiephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application February 19, 1948, Serial No. 9,509

6 Claims.

This invention pertains to counting apparatus, and more particularly to word or character counting apparatus which may be connected to an electrical conductor over which astart-stop signaling code comprising various combination of current and no-current intervals is transmitted.

The usual means for counting the words or characters transmitted by a teletypewriter station utilizes a mechanical connection to the teletypewriter keyboard or 'tape transmitter, or utilizes apparatus which indicates the elapsed time of operation as a representation .of the number of a receiving station so as to notify an operator at the sending station that the code signals are not being received properly or that the receiving station has an urgent message to be transmitted which should take precedence over the message then being transmitted. Reference may be made to Patent 1,904,164 issued to Sterling Morton et al.

,- on April 18, 1938, for a disclosure of a teletypewriter station which fulfills the foregoing condiwords or characters transmitted, The latter =3:

any part of a line interconnecting teletypewriter stations and which will indicate an accurate count for signals generated by either keyboard or tape transmitter operation.

The invention features an arrangement in which each transmitted character code combina-: 2

tion causes an incremental advancement of the counting apparatus, and the count is registered directly as a totalization of words of standard or average length.

Other objects and'advan tages of the invention will be apparent from a consideration of the following description, the appended claims, and the drawings, in which: I

Fig. 1 indicates the mechanical and electrical features of the counter; and

Fig. 2 is a sectional view of the escapement apparatus.

The apparatus disclosed in Fig. 1 is designed for use in conjunction with an electrical conductor over which a start-stop, five-unit signaling code is transmitted, wherein the code. consists of five impulses, each of which may be a marking (current) impulse or a spacing (no current) impulse. Each group of five signaling impulses is preceded by a start signal (a spacing impulse) and followed by a stop signal (a marking impulse) which may be of the same duration as the code impulse signals or of slightly greater duration than the code impulse signals and serve to maintain synchronism between allstations interconnected by the ,1

the line is normally never in atotal spacing. (i..e..,',;

current off) condition, except when the system. is

' completely shut down or the circuit is unintentionally broken due to a trouble condition, or the circuit is intentionally brokenbyan operator at tions and utilizes a keyboard transmitter, and the disclosure of the Morton patent is incorporated herein by reference as part of the present specification. It is to be understood that the counting apparatus disclosed herein may be used along a line conducting any type of electrical code signals provided each group of code signals which reprecents a character is preceded by a certain electrical condition and is followed by a different electrical condition.

The disclosure of the mechanical and electrical features of the counting apparatus in Fig. l indicates that the registering mechanism is operated by a constant speed electrical motor through mechanical interconnecting means and that both the motor and the interconnecting means are under the control of electrical apparatus which is connected to an electrical conductor interconnecting two teletypewriter stations such as the type disclosed in Patent 1,904,164.

The counting apparatus disclosed in Fig. 1 is controlled by a relay I2 having its winding connected in series with the telegraph lineal. Relay I2 is preferably of a low impedance type so as not to modify the electrical characteristics of line 3i to the extent that the transmission of code signals from One station to another would be interfered with. Also, relay i2 should be of a design that will respond to the rapid changes in line current produced by the code signals. The armature of relay !2 is operated while the idle condition marking current is being passed through the line, and when the start signal is transmitted over the line, the armature releases and thereafter operates and releases in accordance with the code signals transmitted over the line. The stop signal causes the armature to operate again, thereby preparing the apparatus for the next code signal.

The front contact of relay i2 is connected to the winding of relay [4 which is a slow-releasing type, and the back contact of relay i2 is connected to the windingof electromagnet B6. The direct current output of the rectifier I3, the input of which is connected to a source of alternating current, is connectable to the windings of relay i i and electromagnet it through the armature of relay i2, from which it follows that current is allowed to flow through the armature of relay E2 to the 'Winding of relay it during each marking impulse 'jor signal and to the winding of electromagnet l6 during each spacing impulse or signal.

Relay I4 is designed so that its armature is not released unless the flow of current to the relay winding is interrupted for a certain length of time which exceeds the maximum time during which successive spacing signals and impulses are ordinarily sent over line 3|. For the five-unit code commonly used in teletypewriter circuits this maximum time consists of the time required for the start signal and the total time required for the live signaling impulses. Thus, the armature of relay |4 remains operated at all times unless line 3| is not energized for a time exceeding the maximum time during which continuous spacing signals and impulses are normally sent over the line. Constant speed motor I5 is energized through the armature and front contact of relay l4, and as stated hereinbefore, line 3| remains in a spacing condition for an interval of time exceeding the code signal intervals and releases relay I4 only when the line circuit is unintentionally broken due to a trouble condition or when the circuit is intentionally broken by an operator. Since these two situations seldom occur under normal operating conditions, motor I5 is normally operated continuously.

Electromagnet I6 is designed so that instantaneous operation or release of its armature is obtained when its winding is energized or deenergized depending upon the condition of relay l2. Thus, the armature of electromagnet I6 is released while marking signals or impulses are being transmitted over line 3| and the armature is operated while spacing signals or impulses are being transmitted. The armature of electromagnet I6 serves as a controlling means in an escapement mechanism which will be described hereinafter.

Motor I5 is coupled to shaft I! through gears I9 and 20, and the speed of the motor and the gear ratio are proportioned so that shaft rotates at one-sixth the speed of the receiving shaft of the teletypewriter stations. Shaft I1 is coupled to shaft 21 through friction clutches 2| and 25. Escapement wheel 22 is attached to shaft 21 in a position so that its movement is under the control of the armature of electromagnet I6, and gears 23 and 24 couple shaft 2'! to rotation counter 29 so that the rotation counter registers one count for each revolution of shaft 21. Rotation counter 29 may be any apparatus adapted to be coupled to a shaft and adapted to indicate the cumulative number of revolutions which the shaft makes.

The escapement wheel is provided with six protrusions evenly spaced around the periphery of the wheel and positioned so as to engage with the armature of electromagnet I6 when the armature is in a released condition. Thus, escapement wheel 22 and shaft 2'! are not allowed to rotate while the armature of electromagnet I6 is engaged with one of the protrusions on the escapement wheel, and when this condition prevails friction clutches 2| and 25 permit continuing rotation of shaft IT. The protrusions on the escapement wheel are spaced so that the operating time for each escape cycle is substantially equal to the time required for a start-stop permutation code signal combination.

While the idle condition marking current is being transmitted through line 3|, the armature of relay I2 is operated, the armature of relay I4 is operated and the armature of electromagnet I6 is released. Therefore, motor I5 and shaft I'I'will revolve continuously, but shaft 21 is not allowed 'to revolve and actuate revolution counter 29 since the armature of electromagnet I6 is engaged with one of the protrusions on escapement wheel 22.

When the first start signal is transmitted over the line, the armature of relay l2 releases, thereby interrupting the flow of current to the winding of relay M and energizing the winding of electromagnet I6. Since relay I4 is a slow-releasing type, its armature remains operated and the flow of current to motor I5 is not interrupted. However, the armature of electromagnet I6 operates and disengages from the protrusion of escapement wheel 22, thereby permitting the escapement wheel and shaft 21 to rotate under the influence of the rotation of shaft IT as applied through clutch 2|. While the spacing and marking impulses representing the first code character are transmitted over line 3|, the armature of relay I4 remains operated and the armature of electromagnet l6 responds to the impulses by operating during spacing impulses and releasing during marking impulses. Since the periphery of the escapement wheel between adjacent protrusions contains no irregularities which could engage with the released armature of electromagnet I6 and since the time required for the transmission of a start signal and the code impulses and a portion of the stop signal equals the time required for the escapement wheel to make one-sixth of a revolution, it is apparent that the rotation of escapement wheel 22 is not interrupted during the time required for the transmission of the code combination. However, when the stop signal is transmitted over line 3|, the armature of electromagnet I6 is released and the armature is in position at this time to engage a protrusion on the escapement wheel, thereby stopping rotation of the escapement wheel after it has rotated one-sixth of a revolution. Since there are six protrusions evenly spaced around the periphery of the escapement wheel and since the escapement wheel rotates at one-sixth the speed of the receiving shafts of the teletypewriter stations, a protrusion is always moving into a position to engage with the armature of electromagnet I6 when astop signal is transmitted over line 3|.

The receiving shafts of teletypewriter stations such as disclosed in Patent 1,904,164 are ordinarily rotated at a speed which permits the receiving mechanism to assume a brief idle condition after each code combination is registered. Since the shafts of the word counter herein disclosed rotate at a speed which is a fixed proportion of the speed of the receiving shafts of the teletypewriter stations, the mechanism of the word counter will also assume a brief idle condition after each code combination actuates the escapement mechanism.

Thus, it is apparent that the escapement wheel is permitted to revolve one-sixth of a revolution during the transmission -of each code combination over the line and that the start signal which precedeseach-code combination serves to cause the'escapement wheel-to be released and that the stop signal which succeeds each code combination serves to'cause the escapement wheel to be stopped. Also, it is apparent that the escapement wheel will not be allowed to rotate while an idle condition marking current is being transcelerates.

' tions.

5..- the condition of the escapement mechanism at a time corresponding to the end of the second code impulse. During the third, fourth and fifth impulses the escapement wheel will be free to move in a counter-clockwise direction, and when the 'rna'rking or stop signal is transmitted, protrusion '30 will engage with the armature of electromagnet I6, thereby preventing further rotation of the escapement wheel until a spacing signal is again sent over line 3I.

Rotation counter 29 is coupled to shaft 21 through gears 23 and 24 so that the counter registers one count for each complete revolution of shaft 21. Thus, one count as registered by counter 29 indicates that the escapement mechanism has completed the six steps required to permit the escapement wheel to make one revolution and that six code combinations and the corresponding six start and stop signals have been transmitted over line (H. In commercial communication systems it is common practice to designate six code combinations as representing one word including the space which separates that word and the succeeding word. Thus, the apparatus disclosed herein is adapted to indicate the cumulative number of groups of six characters transmitted over an electrical conductor, and this indication represents the cumulative number of words transmitted.

There remains for consideration the operation under the condition that a steady spacing signal is transmitted, whether it be an intentionally transmitted break signal or a line fault. Relay I2 responds in the same manner as previously described, releasing its armature to complete the energizing circuit of electromagnet l6 and in- 'terrupting the energizing circuit of relay I4.

Electromagnet I6 releases escapement wheel 22 and the wheel begins to revolve. Relay I4 will release its armature in an interval not less than that of six successive spacing impulses, thereby interrupting the circuit of motor I5 which de- Depending upon the number of revolutions the motor shaft undergoes in coming to a stop, the escapement wheel 22 will revolve through a proportional number of sixth revolu- If the escapement wheel 22 completes a full revolution it will cause counting device 29 to register an additional word. It is within the contemplation of the invention that the characteristics of the motor I5 shall be such that the deceleration and coming to rest of the motor shall occur in not more than one revolution of escapement wheel 22.

Experience in the operation of telegraph circuits has shown that on the average, continuous spacing intervals which would cause the release of relay I l, whether intentional or fortuitous, occur not more than ten times during a days operation. Ordinary teletypewriter transmission is at the rate of 3600 or more Words p r hour. Even if break signals or unintentional long spacing signals should be transmitted at the rate of ten per hour and assuming the registration of one word on indicator 29 for each such transmission, the deviation of the indication from the actual total of character codes transmitted would be well under one per cent. In the interest of simplicity and with the thought that such deviation would be tolerable from a practical and operating standpoint, the control exercised by relay I4 may be as shown in Fig. 1. In the event that a greater degree of accuracy is desired, it may be afforded by eliminating the deceleration time of motor I5 as a factor in the operation of 6. escapement wheel 22 following the release of re lay l4. For example, there could be added to the device a clutch, either friction or positive, interposed between the shaft of motor I5 and gear [9, together with a stop magnet-having its energizing circuit controlled by relay I4, with motor I5 arranged to run continuously. Such clutch and. stop magnet might, for example, be of thetype shown in Patent 2,055,567 granted September 29, 1936 to E. F. Watson, and the disclosure of the Watson patent is incorporated herein by reference as part of the present specification. With such an arrangement the release of .relay I4 would result in the release of the stop magnet, which would cause gear I9 to be arrested in not more than one revolution after the release of stop magnet. Since the relay I4 must hold its armature for the interval of at least six successive spacing impulses, and may hold its armature for as much as a full code combination includingthe stop impulse time, the escapement wheel 22 might be expected to have exceeded one-sixth revolution at the time of the release of the armature of relay I4. Because of the speed reducing gear relation between gears I9 and 20, and because of the fact that gear l9 could be stopped in not more than one revolution by means of the stop magnet, the escapement wheel would be stopped before it has traveled one-third of a revolution from the point at which it was released and consequently the deviation of the indication from a true count would not exceed one word for each three line interruptions.

It will be apparent that when relay releases in response to conditions hereinbefore described, and shaft I7 is brought to rest, whether by the stopping of motor l5 or the stopping of gear H] by means of a clutch, escapement wheel 22 may stop in a position of partial completion of one of its one-sixth revolution steps, with one of the protrusions 30 of the escapement wheel having passed the blocking lug of the armature of electromagnet I6 and the next protrusion -30 not having reached the blocking lug, which is equivalent to the instantaneous condition shown in Fig. 2. Upon the reenergization of line 3| and line relay l2, relay M will be reoperated, shaft I! will. be restarted, and electromagnet IE will be released. Teletypewriter systems are frequently operated at a speed of words per minute or higher, from which it follows that the speed of rotation of escapement wheel 22 equals or exceeds one revolution per second. Accordingly, the escapement wheel 22 will be brought to rest by the armature of electromagnet IS in an interval less than one-sixth of a second, and the arrestment of the escapement wheel 22, so that it willthereafter operate in the proper phase relation to the start and stop impulses of telegraph signals, may be accomplished merely by delaying message signal transmission for an interval of the order of one-sixth second, or slightly longer if the motor I5 is slow in coming up to speed.

Although a specific embodiment of the invention has been shown and described, it will be understood that modifications may be made therein without departing from the scope and spirit thereof as defined by the appended claims.

What is claimed is:

1. A counting apparatus comprising an electrical conductor interconnecting a plurality of teletypewriter stations, a driving motor, a registering mechanism, interconnecting means including an escapement mechanism and a friction clutch between said driving motor and said registering mechanism, said interconnecting means being adapted to rotate at a speed which has a fixed submultiple relation to the speed of rotation of the receiving shafts of said teletypewriter stations, and a controlling device responsive to signaling impulses in said conductor and adapted to control the rotation of said escapement mechanism and interconnecting leans in accordance with predetermined ones of said signaling impulses, thereby causing said registering mechanism to cumulatively register groups of transmitted code signal representations of characters in which each group comprises code signal representations equal in number to the reciprocal of said submultiple, said controlling device being adapted to deactivate said driving motor if said electrical conductor is deenergized for a predetermined length of time.

2. A counting apparatus comprising an electrical conductor interconnecting a plurality of teletypewriter stations over which code signals representing characters are transmitted, each code representation of a character being preceded by a first predetermined electrical condition and followed by a second predetermined electrical condition, a driving motor, a registering mechanism, interconnecting means including an escapement mechanism and a friction clutch between said driving motor and said registering;

mechanism, said interconnecting means being adapted to rotate at a speed which has a fixed submultiple relation to the speed of rotation of the receiving shafts of said teletypewriter stations, and a controlling device responsive to signaling impulses in said electrical conductorand adapted to cause said escapement mechanism and interconnecting means to rotate when said first predetermined electrical condition is transmitted over the electrical conductor and to continue rotating until said second predetermined electrical condition is transmitted over the electrical conductor, thereby causing said registering mechanism to cumulatively register groups of transmitted code signal representations of characters in which each group comprises code signal representations equal in number to the reciprocal of said submultiple.

3. A counting apparatus comprising an electrical conductor interconnecting a plurality of teletypewriter stations over which code signals representing characters are transmitted, each code representation of a character being preceded by a start signal comprising a time interval during which said electrical conductor is in a nonconducting condition and each code representation of a character being followed by a stop signal comprising a time interval during which said electrical conductor is in a conducting condition, a driving motor, a registering mechanism, interconnecting means including an escapement mechanism and a friction clutch between said driving motor and said registering mechanism, said interconnecting means being adapted to rotate at a submultiple of the speed of rotation of the receiving shafts of said teletypewriter stations, and a controlling device adapted to cause said escapement mechanism and interconnecting means to rotate when said start signal is transmitted over the electrical conductor and to arrest said escapement mechanism and interconnecting means when said stop signal is transmitted over the electrical conductor, thereb causing said registering mechanism to cumulatively register groups of transmitted code signal representations of characters in which each group comprises code signal representations equal in number to the reciprocal of said submultiple.

4. In association with a start-stop permutation code telegraph system including a telegraph line, a counting device, driving means therefor, an escapement mechanism operatively interconnecting said driving means and said counting device and having an operating time per escape cycle substantially equal to the time required for a start-stop permutation code signal combination, means responsive to spacing impulse transmission over said line for initiating an escape cycle of said escapement mechanism whereby to efiect an incremental operation of said counting device, and means responsive to prolongation of said spacing impulse appreciably beyond said escape cycle operating time for stopping said escapement mechanism.

5. In a counting apparatus, a normally energized communication conductor, means for transmitting code signals involving interruptions in the energizing current over said conductor, a registering means, a driving means therefor, interconnecting means between said driving means and said registering means, a controlling device responsive to interruptive conditions of said code signals for activating said interconnecting means to cause said registering means to register a summation of code signals transmitted over said conductor, and means responsive to an interruptive condition exceeding a predetermined duration for deactivating said driving means.

6. In a communication system in which fixed and equal numbers of code signal combinations represent words for counting purposes, a communication conductor, means for transmitting code signal combinations over said conductor, a registering device, a driving means therefor, interconnecting means between said driving means and said registering means adapted to advance said registering means one unit for each revolution of said interconnecting means, and a controlling device responsive to code signal combinations and adapted to cause a fraction of a revolution of said interconnecting means equal to the reciprocal of said fixed and equal number whereby each unit registered by said registering means represents a word.

WILMARTH Y. LANG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,744,259 Carlson Jan. 21, 1930 2,023,574 ,Cohn Dec. 10, 1935 2,086,913 Kelly, Jr. July 13, 1937 2,191,798 McCann Feb. 27, 1940 2,392,256 Nichol Jan. 1, 1946 2,421,681 Chaskin June 3, 1947

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