US1932932A - Start-stop telegraph system and apparatus therefor - Google Patents

Description

Oct 1933- R. G. GRIFFITH START-STOP TELEGRAPH SYSTEM AND APPARATUS THEREFOR Filed July 22. 1932 4 She ts-Sheet l Fig.1.

\|I.IL T T h S 1% MH IIIII l T s W Fll lllll II, S w 6 /0A S 5 5 H 5 5 m 4 4 4 4 3 J m 3 3 n 2 fl 2 97h 1 IIIIIIQ 1 l n T T T T S S A B C D INVENTOR RONALD G. GRIFFITH ATTORNEY Get. 31, 1933. R. G. GRIFFITH START-STOP TELEGRAPH SYSTEM AND APPARATUS THEREFOR Filed July 22, 1952 4 Sheets-Sheet 2 mm mm mm IN VE.NTOR RONALD c. GRIFFITH ATTORNEY Oct. 31, 1933. R, G. GRIFFITH 1,932,932

START-STOP TELEGRAPH SYSTEM AND APPARATUS THEREFOR Filed July 22, 1932 4 Sheets-Sheet 3 lNVENTOR RONFKLD G. GfiiFFiTH ATTORNEY Oct. 31, 1933- R. G. GRIFFITH START-STOP TELEGRAPH SYSTEM AND APPARATUS THEREFOR Filed July 22, 1932 4 Sheets-Sheet 4 @Qw wQN Sum INVENTOR RONALD G. GRIFFITH ATTORNEY Patented a. 31, 1933 PATENT OFFICE START-STOP TELEGRAPH SYSTEM AND APPARATUS THEREFOR Ronald George Griffith, Croydon, England, as-

Signor Crcydon, England to Creed and Company,

Limited,

Application July 22, 1932, Serial No. 624,061, and. in Great Britain June 2, 1932 20 Claims.

This invention relates to start-stop telegraph systems and apparatus and more particularly to a mode of operation and the construction of apparatus for obtaining advantages of-operation according to either a five-unit or a six-unit code. It is well known that in telegraph systems operating on an equal length code of five units a maximum of 32 characters are selectable by signals composed of permutations of two conditions of each of the five elements in the code. It is usual, therefore, in such systems to allot appropriate signal combinations for the purpose of efiecting case shift operations whereby fur ther characters or functional operations such as line and page feed, can be selected in another case group. This is probably the arrangement in most general use as the principal printing characters such as letters can be selected by equal length code signals composed of the least number of elements, whilst the lesser used characters such as figures, and other selectively con trolled printer functions, can be selected when required by the transmission of the additional case signal combinations.

In dealing with telegraph message trafiic containing figures very frequently interspersed between letters such as when dealing with stock quotations, commodity prices and the like, the advantage of a short five-unit code is greatly minimized by the time necessary for the transmission of the necessary case signal on each change from one case group to the other, as well as by the possibility of accidental omission of a case signal. For such telegraph trafiic a system operating according to an equal length code of six elements is generally favoured. In this case five of the elements can be considered as effecting selection as in the case of the fiveunit code and a sixth variable element which is now included with every signal combination determines the selection in one or another case group in accordance with the character of the sixth element.

In practice, therefore, an advantage would be obtained by the ability to convert a system readily from operation according to one or the other of a five-unit and a six-unit code. A further an. possibly greater advantage would be obtained by an arrangement which permitted the manufacture of apparatus, for operation according to either code with a minimum of alteration or additional complications.

According to one aspect of the present application, therefore, a start-stop telegraph system is arranged and adapted to be operable according to either a five-unit or a six-unit code. It will be clear from the detailed description hereinafter given that the methods employed are not limited to systems operating according to the codes above mentioned but in eifectmay be applied to any start-stop system wherein selections are normally effected under the control of signal combinations each consisting of a definite number of elements and wherein it is desired by the addition of one permutation element t the aforementioned signal code to increase the range in which a selection can be effected directly by each signal combination. 7

With reference more particularly to the novel features of the telegraph apparatus as adapted for the purposes of the present invention, it may be noted that in signal transmitting and signal receiving apparatus for telegraph systems operating on the start-stop code, it is usual for each signal combination to consist of an invariable start element followed by a definite number of variable permutation elements and a final stop element of invariable opposite character to the start element. For a key-board controlled signal transmitter and for printing apparatus in such systems, it is necessary to employ translating or selecting mechanism effecting co-operation between a series of members corresponding to the permutation elements of each signal combination and a single member corresponding to the printing character or signal in question. An electrical distributor in which a brush sweeps over a series of contacts may be employed for this purpose, but in general it may be stated that for both transmitting and receiving apparatus such translating or selecting mechanism usually comprises cam means which is released at the commencement of each signal combination to complete one cycle of movement, usually one revolution of rotation, by a local source of mechanical power, and a series of permutation members with which the cam means is adapted to co-operate in succession during each cycle of movement. In such translating or selecting mechanism it will usually be found that there is a period following co-operation With the series of permutation members and before completion of the cycle of movement which corresponds to the stop element of each signal combination.

According to a main feature of the present invention, a translating mechanism of the class referred to above is employed for operation according to signals of one code in the usual manner, and the period during the cycle of movement of the cam means as above mentioned is utilized for the co-operation of the cam means with a movable member in a manner similar to that of any of the series of permutation members, when it is desired to adapt the same translating mechanism for operation according to signals of a code in which a further signal element had been added. With this arrangement it will be seen that the cycle of movement of the cam means is employed almost wholly in co-operating with a series of permutation members of which the last in the series is the movable member referred to and this member is arranged to be rendered inoperative as regards direct co-operation with the cam means when the shorter code is being employed. This may require other measures to provide for the stop element of the signal code in the case of a signal transmitter.

Another feature of the present invention, therefore, relates to the provision of means in a signal transmitter arranged to transmit signals according either to one or the other of two codes as above outlined, for adding a stop element to each signal combination when signals according to the longer code are being transmitted.

It will be seen from the detailed description hereinafter given that no special provision is required for the equivalent of the stop element in signal receiving apparatus according to the present invention. The cam means of the translating or selecting mechanism is released in response to the invariable start element of each signal combination and is arranged to be automatically rearrested on completion of its cycle of movement in a similar manner to that of the transmitting apparatus and irrespective of the stop element of each received signal. It may be advisable or advantageous, however, to rearrange the means which effect the operations, such as transfer of the settings of the permutation members to a further series of members for subsequent selection of a printing character and the printing of the character. In known apparatus these operations are generally arranged to be effected whilst the permutation members are being set under control of a succeeding signal combination. The methods to be adopted in the present instance will vary with the type of apparatus to which it is desired to apply the invention, but in this connection reference can usefully here be made to my U. S. Patent No. 1,924,357 in which a method of control of the cam means is described which has the advantage of restoring the period of time before the completion of a cycle of movement of the cam means, for the transfer of the settings of the permutation members to a further series of members and other operations.

A further feature of the invention relates to the method of control of one of a series of members in the translating mechanism of a signal receiving apparatus either by a corresponding element in each signal combination in the longer of two codes or in response to particular signal combinations of the shorter of the two codes.

In order that a clear understanding may be obtained the invention will now be described with reference to the accompanying drawings in which:

Fig. 1 is a diagram illustrating the principle of the main feature of the invention,

Fig. 2 shows certain portions of a keyboard controlled signal transmitter adapted to transmit signals according to a code having either five or six units in accordance with the position of a change-over lever.

Fig. 3 shows a selecting mechanism for a signal receiving apparatus which is particularly suitable for the purposes of the invention.

Fig. 4 shows a method of control of a sixth permutation member in a signal receiving apparatus in accordance with either a particular element in each signal of six permutation elements or in response to particular code signal combinations of five permutation elements.

Referring to Fig. 1 the section A represents diagrammatically a signal combination arranged accordingly to the usual start-stop code of an invariable start element STT followed by five permutation elements numbered 1 to 5 consecutively and an invariable stop element STP of opposite character to the start element. In the diagram the character such as positive or negative of each of the signal elements is represented by the vertical position of the thick line relatively to the base line. The second, third and fifth permutation elements are shown as havingthe same character as the start element, whilst the first and fourth permutation elements, together with the stop element, are shown as having the opposite character. The whole signal combination is composed of a total of seven elements of which the character of the permutation elements 1 to 5 can be varied in accordance with each particular signal i" the five-unit code. In a keyboard controlled signal transmitter it is convenient to consider the means for transmitting a signal combination of this character as a cam sleeve which is released for one revolution and effects during this revolution the transmission of all the signal elements in succession. In a signal receiving apparatus operating under control of the signal shown in section A of Fig. 1 a cam sleeve may be considered as released in response to the start element of a received signal combination to rotate for one revolution and to co-operate with each of a series of five permutation members in succession at brief intervals corresponding as nearly as possible with the centre portion of each received permutation element of the signal. This is represented diagrammatically in section B of Fig. 1 where for convenience the cam sleeve is shown as released for rotation at an instant corresponding to the commencement of the received start element, the revolution of the receiving cam sleeve being represented as completed with the termination of the received signal. This explanation will be readily comprehended in view of what is known in the art although in practice it will be appreciated that the conditions represented in section B are only approximate as the receiving cam sleeve is seldom released at the precise instant relatively to the received signal as is represented in the figure and also it may be desirable for the cam to complete its revolution shortly before the termination of the stop element. In either case, however, the timing of the actuation of the five permutation members is arranged to occur as nearly as possible in synchronism with the received permutation signal elements as already stated.

The above described method of operation is the usual method adopted when a five-unit code is adapted to the start-stop principle of operation. This method is substantially the same when the apparatus according to the present invention is operated on a similar five-unit code. Sections C and D of Figure 1, however, represent the mode of operation according to the present invention when a change over from a five-unit to a six-unit code has been effected. Section C shows a signal combination on similar lines to that shown in section A, but a sixth element having the same character as a fifth element is inserted after the fifth element and before the invariable stop element. The signal combination as transmitted is now composed of a total of eight elements instead of seven and assuming, for convenience, the same signal speed of the elements as shown in sections A and B the whole signal as transmitted now occupies a proportionately longer time period. This is shown more clearly by the position of the start element, of a succeeding signal shown in sections A and C. If the signals are transmitted by a tape controlled transmitting apparatus the start element would follow the stop element of the preceding signal without pause. Each revolution of the transmitting cam sleeve in this case would occupy a time period equal to that of the eight elements instead of seven. If the signals are transmitted by a key-board controlled transmitter, however, it will be appreciated that a pause of any length may intervene. In the figure a short pause of equal length in the two cases is shown and the signal transmitted as shown in section C occupies a period of time equal to that of one element more than the signal transmitted as shown in section A. In either case for the present it will be assumed that signal combinations as described are transmitted by appropriate apparatus for the purpose. A method will hereinafter be described whereby a key-board controlled transmitter can be changed over from signals of one code to signals of the other code.

If now the cam means of the signal receiving apparatus, instead of co-operating with a series of only five members, co-operates also with a sixth in the period corresponding to the stop element in a signal combination in the fiveunit code the receiving apparatus can be adapted to operate interchangeably on either a five or a six-unit code with only minor alterations. In section D of Fig. 1 for instanceythe cam sleeve is released on the commencement of a received start element and completes its revolution after a period of time equal to seven signal elements. The first five permutation members are selectively actuated in synchronism with the first five permutation elements of the received signal, but in this case a sixth member is also selectively actuated in synchronism with the sixth permutation element of the signal just beforethe receiving cam means completes its revolution. The stop element of the received signal follows so that in this case a correspondingly longer pause ensues, as shown in section D of the figure, before the receiving cam means is released for a succeeding signal. If signals according to a five unit code are being received, the sixth member will always be actuated to one position corresponding to the invariable character of the stop element of the signal combination. If signals according to a six unit code are being received, the sixth member will be actuated to one or other of two positions in accordance with the character of the sixth signal element. If desired, during the reception of five-unit signals the sixth member could be-removed from operative relation with the cam means or alternatively in a signal receiving apparatus as will later be seen, a member can be arranged to be controlled by appropriate signal combinations in a five-unit code for case shift purposes and by a sixth member as above described if six-unit signals are being received.

In translating to selecting mechanism of both receiving and transmitting apparatus where cam means is released for rotation by a local source of mechanical power from one position to another for each signal combination, it is of importance that the cam means co-operate with the series of permutation members in accurately timed relation with that of the starting element. It will be seen from the above description that this condition is achieved for the actuation of the sixth member in the receiving apparatus in the same way as for any other of the series of permutation members. In the case of a signal transmitting apparatus however, the duration of the .stop element is not of the same order of importance. It will shortly be seen that this permits a ready means of adapting a keyboard controlled transmitting apparatus to transmit signals according to either a five-unit or a sixunit code. The main feature to be noted from the above description, however, is that in translating or selecting mechanism for start-stop transmitting and receiving apparatus cam means can be arranged to co-operate successively with each of a series of permutation members for ,one or the other of two signal codes in one cycle of movement of the cam means for each signal combination.

Referring now to the signal transmitting mechanism shown in Fig. 2, a series of key-levers of which two only 10 and 11, are shown, are adapted on depression of any one to set each of a series of six permutation bars 12 to 17 in one or another longitudinal position through inclined face cam lugs in well known manner. Bars 12 to 16 inclusive control the transmission of five corresponding elements of each signal combination according to a five-unit code, whilst bar 17 controls the transmission when required of a sixth permutation element for a six-unit code. Each of the bars 12 to 16 rocks a corresponding T lever 18 to 22, independently pivoted on rod 25, a further T lever 23 also independently pivoted on rod 25 being rocked by a bar 26 which can be coupled for longitudinal movement with bar 17 by a latch 27. A finger operated change-over lever 28 pivoted at 29 on a suitable fixed portion of the apparatus is adapted in one position to permit latch 27 pivoted on bar 17 to be actuated by a spring into engagement with a notch inbar 26, and in the other position to hold latch 27 out of engagement with the notch whilst locking bar 26 in one position. Each of the series of T levers 18 to 22 and 23 at the extremities of the two oppositely extending arms carries a pair of levers 3'7 not rock on rod 25, its position being fixed by pins 40 and 41 and one only of its levers 43 being operative to send an invariable start element of each signal combination as will shortly appear.

All of the levers 37 and 38 on the rocking T levers 18 to 23 are of equal length and their upper extremities are moved, in accordance with the rocking movement of each T lever on which they are pivoted, into or out of operative relation with one or the other of two horizontal rods 44, 45 attached to brackets 46, 47 pivoted at 48 and 49 respectively on a fixed part of the apparatus; the rods 44 and 45 being operable by the outward movement of any of levers 37 and 38 in opposite directions respectively, when rocked by the T levers to bring them into operative relation. Each of the cams 31 to 36 is arranged on sleeve 30 to actuate their pairs of levers 37, 38 in cyclic sequence after the actuation of levers 42 and 43 by cam 39 during each half revolution of the cam shaft 30. The rotation of this shaft 30 is effected by a friction clutch mechanism shown as a friction disc 50 pressed by a three-armed spring 51 between a disc 52 keyed to shaft 30, and a driving gear wheel 53. An escapement mechanism comprising a double-toothed disc 54 fixed to the shaft 30 is engaged by a detent 55 pivoted'at 56 which is moved to a position to release disc 54 on each depression of a key-lever 10, 11, through a tripping member 57 and a bar 58 having an inclined cam face under each of the key levers. The tripping member 57 is actuated by a cam 59 after each release of the shaft 30 to permit the return of detent 55 to rearrest the shaft through disc 54 after each half-revolution of rotation independently of the continued depression of a key-lever. The movements of horizontal rods 44 and 45 in Fig. 2 are shown as actuating a signalling contact lever 60 alternately between contact screws 61 and 62 through pins 63 and 64 on bracket 46, a spring 65 being provided to hold the lever 60 against one or the other contact screw and to furnish a quick snap action to the lever.

The mode of operation of the transmitters as thus described is as follows. With the changeover lever 28 actuated to the position indicated by the dotted lines, on depression of a key-lever, permutation bars 12 to 16 will be set in accordance with the five elements of the signal corresponding to that key-lever, to cooperate with the cam shaft 30, but the sixth bar 17 will be inoperative as latch 2'7 is disconnected from bar 26. Bars 12 to 16 rock their associated T levers 18 to 22 which thereby raise one of their upwardly extending levers 37 and 38 so that its extremity is level with horizontal rod 44 or 45 respectively and depress the other lever so that its extremity is below the level of its corresponding horizontal rod. The depression of the keylever also invariably actuates bar 58 against tension of its spring to release the escapement 54, whereupon cam shaft 30 is rotated for half a revolution by the local source of power applied to gear wheel 53. Immediately upon commencement of rotation of cam shaft 30 cam 39 actuates outwards its levers 42 and 43 but only lever 43 is of a length to engage and actuate rod 45 and thus actuate contact lever 60 against contact screw 62 to send an invariable start element for that signal. Following in timed sequence, the cams 31 to 35 actuate their corresponding pairs of levers 37 and 38, the raised one only being effective to actuate its rod 44 or 45 and snap the contact lever in the appropriate direction. If two successive pairs of levers 37, 38 have similar settings, however, it will be understood that the contact lever is not moved for the second pair. Following the actuation of the contact lever 60 by cam 35, cam 36 actuates its pair of levers but as with the change over lever 28 in this position, bar 26 is maintained in its left-hand position the lever 37 only of the pair is operative to move the contact lever to send an invariable stop element of opposite character to the start element and complete the signal combination. The cam shaft 30 is then rearrested in preparation for a further signal.

The timing of the signal elements as above described will be seen to be according to that of section A of Fig. 1 as previously mentioned. With the change-over lever 28 actuated to the position shown in full lines in Fig. 2, on engagement of latch 27 with the notch in bar 26 the sixth permutation bar 17 becomes effective to change the invariable stop element of signals according to the five unit code into a sixth permutation element varying in character in accordance with the position of bar 17 as with bars 12 to 16. In order to re-introduce a terminating stop element a second cam shaft 66 is shown in Fig. 2 driven through a friction clutch similar to that for shaft 30, from a gear wheel 67 having the same number of teeth as wheel 53 and conveniently driven from a common driving wheel 68. Shaft 66 carries disc 69 having two diametrically arranged teeth engageable with a lever '70 pivoted at 71, the opposite end of the lever bearing under spring tension on a cam '72 fixed to the shaft 30. Cam 72 has two teps cach arranged to permit lever '70 to fall and release the second shaft 66 at a period corresponding to the termination of the first or start element and the commencement of the first permutation element of each signal, as determined by the first shaft 30. To hold the shaft 66 from release when five-unit signals are being transmitted, a latch member 73 is pivoted at '74 on a stationary part of the apparatus and is actuated by a spring 75 to engage at the upper end with a pin indicated at 76 fixed to lever 70 and thus prevent lever '70 releasing disc 69. The lower end of latch member '73 is engaged by a pin 77 fixed to bar 26 so that when bar 26 is moved to the right when six-unit signals are being transmitted pin '77 moves the latch 73 from engagement with pin 76 and lever '70 is then free to release shaft 66. Shafts 66 and 30 then rotate together at the same speed and on termination of the sixth permutation element of the signal and as shaft 30 comes to rest, a cam 78 on the second shaft 66 actuates a bell-crank lever 79 to move rod 44 and signal contact lever 60 for a stop signal element. Shaft 66 is then rearrested by lever '70 one element length period of time later. It will be noted that with this arrangement shaft 66 will not be released when signals of the six-unit code are being transmitted if the sixth permutation element is already of the same character as the stop element. The arrangement ensures, however, a return of the contact lever to the stop position at the termination of each signal combination in the six unit code in preparation for the start element of a subsequent signal. A further finger-operated lever 80 may be provided to hold latch 73 permanently out of engagement if desired.

Keyboard locking means is also shown in the figure. A sliding locking bar 81 carrying a series of hooked teeth 82 is moved by a pivoted lever 83 which engages with a cam 84 on the cam shaft 30. The cam 84 has two diametrically arranged projections each of which is adapted at each corresponding rest position of the cam shaft 30 to actuate the lever 83 and locking bar 81 against the tension of a spring to a position in which the hooked teeth are clear of the key levers 10, 11. When a key lever is depressed, the cam shaft is released for rotation as previously described, and immediately upon leaving its po-' sition of rest the locking bar is moved to engage one of its hooked teeth 82 into a hole 85 in the depressed key-lever which is thereupon held in the depressed position until the cam shaft has completed its cycle of movement. The remaining teeth 82 on the bar atthe same time move under the other key-levers and prevent the premature actuation of a second key-lever. When six-unit signals are being transmitted,-a cam 86 on the second cam shaft 66 is arranged to lock the keyboard for a correspondingly longer period of time. This can be effected by a second locking bar 87 actuated from cam 86 through a lever 88 in a similar manner to bar 81 and lever 83 respectively, so that the keyboard is only released when the second shaft 66 reaches its position of rest.

The foregoing description of a signal transmitter adapted for operation on a five or a sixunit code is intended purelyas an example of the manner in which the invention can be applied to keyboard controlled signalling apparatus, As moreover, various portions of the apparatus operate according to known principles for the various functions, other alternative methods will suggest themselves to those skilled in the art for the purposes as above outlined.

In Fig. 3 a selecting mechanism of a startstop receiving apparatus similar to that fully described in US. Patent No. 1,639,213 is shown together with the modification described and claimed in my US. Patent No. 1,924,357, previously mentioned. In this case, however, a series of six permutation member actuators are set during a cycle of operations instead of five. A signal receiving relay (not shown) actuates a rock-shaft 150 between one and the other of two positions in accordance with the character of received signal elements. The actuation of rockshaft 150 in response to the starting element of a signal depresses arm 151 which unlatches a clutch controlling arm 152. A cam sleeve 102 is thereupon driven by a driving shaft 101 and immediately upon commencement of rotation effects the return of the clutch controlling arm to a position beyond the relatching position of a double-armed lever 153. A cam 113 on sleeve 102 after a predetermined portion of a revolution effects the release of a main cam sleeve 103 by unlatching a second clutch controlling arm 115. The main cam sleeve 103 is then clutched to the driving shaft 101 and during rotation moves a striker pin 154 opposite each of a series of six actuators 155160 in turn whilst a striker blade 161 is guided to a position either in line or out of line with pin 154 by rockshaft 150 in accordance with the character of each of the series of signal elements following the start element. A sinuous cam on sleeve 103 at the same time oscillates the striker blade 161 in a direction to strike or to misspin 154 in synchronism with the successive elements of the signal. The actuators 155 to 160 are thus selectively moved by the striker blade 161 through pin 154 to pivot on rod 162 fixed to a frame member 163 which is actuated in a vertical direction after all of the actuators have been set in response to a signal combination, to transfer the setting to a further series of members (not shown) and effect the selection of a printing character in any convenient manner.

From what has previously been said with reference to Fig. 1 it will be appreciated that the cams of sleeve 103 are timed and arranged to effect the setting of the first five actuators 155 to 159 in response to the five permutation elements of a signal following the start element. This will correspond to the five permutation elements of a signal in the five-unit code. The sixth actuator 160 will invariably be unoperated when five-unit signals are being received due to the invariable character of the stop element of the received signal which occurs when the cams are in position to set this sixth actuator. When signals according to the six-unit code are being received, however, the sixth actuator can be set or not set-in accordance with the character of this element. The arrangement of a first cam sleeve released in response to the start element of a signal whilst a second cam sleeve carries cams adapted to effect operations in synchronism with the succeeding signal elements enables the operation of transfer of the setting of the actuators and subsequent operations to be effected or commenced before the completion of rotation of the second cam sleeve. This arises from the fact that as the actuators are only moved at brief intervals corresponding to the centre portions of the received signal elements the second cam sleeve is only released by the first cam sleeve just in time for the actuation of the first actuator whereby the period of rotation corresponding to the interval between the release of the first and second cam sleeves can be transferred to the end of the period of rotation of the second cam sleeve as described more particularly in the above mentioned US. Patent No. 1,924,357. This arrangement is advantageous but is not essential for the purposes of the present invention.

Fig. 4 shows an example of the manner in which a bar for controlling case selection is actuated under the control of a letter shift and afigure shift selector bars when signals according to the five-unit code are being received and under the control of a sixth actuator as in the arrangement shown in Fig. 3 when six-unit code signals are being received. In Fig. 4, the bar 200 controlling case selection is shown as a notched bar for effecting, together with five other notched bars of which only one, 201, is shown in the figure, a selection among a number of transverse selector bars corresponding to the characters and selectable operations in the two case groups. It is to be understood that each of the transverse selector bars cooperates with and is selectable by the conjoint action of the six notched bars in the known manner as with a six unit code, excepting the two bars 202 and 203 shown in the figure which .are the letter shift and figure shift selector bars respectively each selectable by the appropriate signal combinations composed of five permutation units only. For this reason bar 200 is cut away under both of these selector bars so that the selection of either bar in response to five-unit signals is not impeded in either position of bar 200. The six notched bars are longitudinally movable in suitable supports (not shown) and are set under the control of received signals by a selecting mechanism which may be similar to that shown in Fig.

3. As seen in Fig. 4, the first of the five actuators 155 and the additional sixth actuator 160 are settable on rod 162 as previously described into either of the positions indicated and are thus brought under one or another extending arm of a corresponding intermediate member 204 and 205 each independently pivoting on point 206. The five members 204 are each formed in one piece so that when rod 162 is raised after the actuators 155 to 160 have been set the five bars 201 are positively moved into one position or the other. Member 205, however is formed of two independently movable portions, the second portion 207 constituting one extending arm which is movable through the extremity of an interposable member 208 by the sixth actuator 160 when the latter is in one of its two positions, in this case the position indicated by the dotted lines, to actuate the sixth notched bar 200 in one direction, in this case to the right in the figure; the first portion 205 constituting the other extending arm engageable directly by actuator 160 when the latter is in the other of its two positions shown in full lines in the figure to move notched bar 200 through the medium of a sliding bar 209 in the opposite direction, in this case to the left in the figure. Sliding bar 209 is located by slots 210 out therein, on pins 211 fixed to notched bar 200 so that when six-unit code signals are being received and actuator 160 is set into either position in accordance with the character of the sixth permutation element, bar 200 is moved on the raising of rod 162 either to the left, as seen in the figure, through member 205, bar 209, and'pins 211, or to the right through interposable member 208 and member 207, when the pins 211 will return bar 209 with the return movement of notched bar 200. In the intervals between actuation from one position to the other notched bar 200 will remain in the position to which it was last actuated 'as bar 201. To permit the actuation of member 207 by actuator 160, the extremity of interposable member 208 is carried in a slotted guide member 212 in which it is vertically and horizontally movable.

In order to move notched bar 200 in opposite directions in response to letter-shift and figureshift case signals respectively in the five-unit code, a T lever 213 is pivoted at 214 on a stationary part of the apparatus with the oppositely extending arms engageable by projections 215 and 216 on the figure shift selector bar 202 and letter shift selector bar 203 respectively, the third arm of lever 213 engaging a notch cut in the underside of bar 200. When bar 202 or 203 is selected by falling into aligned notches in the first five bars 201 the selected bar is engaged by a universal printing bail 217 in the well known manner and moved against the tension of an individual spring 218, the projection 215 or 216 on the selected bar engaging its corresponding arm of T lever 213 to move bar 200 in one or the other direction. As when actuated by actuator 160, bar 200 remains in the position to which it was last actuated until moved to the opposite position. As the invariable stop element of a signal in the five unit code would effect the movement of bar 200 to a position to effect selection in a case group which may be the opposite to that selected by the appropriate case selector bar 202 or 203, it is necessary that the stop element be inoperative as regards case selection when five-unit signals are being received, and this is the purpose of the interposable member 208. In the arrangement shown in Fig. 4 it is assumed that actuator 160 is invariably set in the position shown dotted in response to the stop element of the signal in the five-unit code and that a signal element of this character would result in figure-shift when six-unit signals are being received. The interposable member 208 is, therefore, arranged to be withdrawn from between actuator 160 and member 207 when selector bar 203 is actuated to effect letter-shift in the fiveunit code. The means for this purpose shown in the figure comprises a bell-crank lever 219 one arm of which is engaged by a projection 220 on bar 203 and the other arm engages a projection 221 on interposable member 208, the end of which, opposite that supported by guide plate 212 is slotted to permit a pivoting and a limited sliding movement on a fixed pin 222. A light spring 223 tends to maintain member 208 in its right hand position with its extremity interposed between actuator 160 and member 207 and also to return vertically in guide plate 212 after actuation by actuator 160. A latch member 224 moved by a light spring 225 on pivot point 226 is adapted to engage a tooth 227 on member 208 and retain this member in latched position with its extremity withdrawn from between actuator 160 and member 207 after selection of bar 203 and actuation by bail 217. To release latch 224 an extension 228 on sliding bar 209 engages an upwardly extending arm of the latch member 224 to release tooth 227 when the sliding bar is moved to its left-hand position in response to the first signal in the six-unit code having a sixth permutation element which sets actuation 160 to the opposite position.

It will thus readily be seen that with this arrangement the bar 200 can control case selection either in response to particular code signal combinations in the five-unit code or in response to the character of a particular signalelement in each signal combination of the sixunit code. When five-unit signals are being received a lettershift signal effects the actuation of selector bar 203 which moves interposable member 208 to the latched position so as to render inoperative actuator 160, which is invariably set in response to the stop element in this code. Five-unit code signals are received and translated in the usual manner, bar 200 being shifted alternately from one position to the other when required by T lever 213 when required in response to selection of bar 202 or 203, without affecting sliding bar 209, the pins 211 moving in slots 210. When six-unit code signals are received a signal containing a letter shift element in actuating member 205 moves latch member 224 to release the interposable member 208, at the same time moves bar 200 to the appropriate position. Actuator 160 is then effective to move bar 200 in one direction or the other in accordance with the character of the sixth permutation element in each signal.

The Figures 2 to 4 of the drawings are intended to illustrate by way of example the manner in which various parts of telegraph signalling apparatus can be arranged or modified in their respective functions to carry out the invention. Where possible an endeavour has been made to indicate the new arrangements as distinguished from what is already known and where other methods of achieving the desired object could be employed. As, however, the idea as described with reference primarily to Fig. 1 is believed to be novel, it is intended that the appended claims be construed to cover the principle involved in this modification and also that of the separate portions of the apparatus which have been described.

What is claimed is: v

1. In a translating mechanism for a start-stop telegraph apparatus, cam means rotatable from one position to another, releasing means operable for each signal combination to control the rotation of said cam means, a series of permutation members selectively co-operable with said cam means during rotation thereof, and means to render inoperative a terminal one of said series of permutation members.

2. In a translating mechanism for a startstop telegraph apparatus, cam means released for rotation from one position to another for each signal combination, a series of five permutation members selectively co-operable in succession with said cam means during rotation thereof, and a sixth permutation member selectively co-operable with said cam means in the last period of each rotation thereof.

3. In a translating mechanism for a start-stop telegraph apparatus, cam means released for rotation from one position to another for each signal combination, a series of permutation members selectively eo-operable with said cam means in accordance with the permutation elements of a signal, and an additional member co-operable with said cam means in accordance with a case determining element of the signal in the last period of rotation of the cam means.

4. In a translating mechanism for a startstop telegraph apparatus, a first'means adapted to effect a cycle of movementfor each signal combination, a second meanshaving a series of elemental portions selectively co-operable with said first means during each cycle of movement, and change-over means operable to effect an invariable manner of cooperation between said first and second means for the last in said series of portions.

5. In a start-stop telegraph transmitter, a plurality of key-levers, a series of permutation members variably actuated thereby, cam means released for movement of a predetermined amount on actuation of any said key-lever, sig nal contact means variably operated by said cam means in accordance with the setting of said series of permutation members and changeover means to control the transmission either of an invariable signal element during each terminating period of movement of the cam means or of a variable signal element under control of one of said permutation members.

6. In a start-stop telegraph transmitter, a plurality of key levers, a series of permutation members variably actuated thereby, cam mean-s released for movement of a predetermined amount on actuation of any said key-lever, signal contact means variably operable by said cam means in accordance with the setting of said series of permutation members, and means to render inoperative one of said permutation members.

7. In a signal transmitter, a series of permutation members each operable into one or another of two positions, operating cam means movable by predetermined amounts, signal contact means successively actuated from one position to another by said cam means in accordance with the position of each said'permutation member, and change-over means operable to effect the invariable actuation of said contact means to a predetermined one of its said positions instead of the variable actuation in accordance with the position of one of said permutation members.

8. In a start-stop transmitter, the combination of contacts for controlling the signal to be transmitted, means for causing said contacts to transmit permutation code signals consisting of an invariable start element followed by a predetermined uniform number of code elements and an invariable stop element, andmeans for changing the predetermined uniform number of code elements.

9. In a keyboard controlled signal transmitter, a series of permutation members each operable into one or another of two positions, operating cam means movable by predetermined amounts, signal contact means successively actuated from one position to another by said cam means in accordance with the position of each said permutation member, means to render inoperative one of said permutation bars, and means actuated thereby to ensure a return of said signal contact means to a normal position.

10. In a keyboard controlled signal transmitter, a series of permutation members each operable into one or another of two positions, a first operating cam means movable by predetermined equal amounts, signal contact means successively actuated from one position to an other by said cam means in accordance with the position of each said permutation member, a second cam means controlled from said first operating cam means to actuate, a predetermined interval after the completion of movement thereof, said signal contact means to an invariable stop position, and changever means operable on actuation to render in-:: io ative one of said permutation members and said second cam means.

11. In a keyboard controlled signal transmitter adapted to transmit signals alternatively according to a five or a six unit code, a series of permuta tion members, signal contact means, a first operating cam means co-operating in succession with said permutation members to actuate said signal contact means variably, a second cam means operable on movement to actuate said contact means invariably, a change-over lever and means operable therefrom to lock the last permutation bar in said series for invariable cooperation with said first cam means and to lock said second cam means against movement.

12. In a keyboard controlled transmitter adapted to transmit signals alternatively according to a five or a six-unit code, a signalling contact lever, a first rotatable cam shaft, a second rotatable cam shaft, a lever operable from said first cam shaft to release said second shaft for rotation, a series of five permutation bars, a sixth permutation bar having a first and a second portion united by a latch member, a second latch member controlled by the second portions of said sixth permutation bar and engageable with said lever to prevent the release of said second cam shaft, and a change-over lever adapted on operation to disconnect the first said latch member and lock said second portion of the sixth bar with said second latch member engaging said lever.

13. In a startestop telegraph transmitter, a plurality of key-levers, a first cam means operable for transmitting signals according to either of two signal codes, a second cam means operable only when transmitting signals according to one of said codes, and locking means for said plurality of key-levers and operable during movement of either of said cam means.

14. In a start-stop signal receiving apparatus operating in response to alternative signal codes comprising an invariable start element followed by five or six permutation elements and terminated by an invariable stop element, a controlling member successively responsive to the character of received signal elements, a cam-shaft released in response to the start element of each signal combination to rotate in timed relation with received signal elements, means under local control for effecting arrest thereof on termination of the sixth element following the start element of each signal, a series of five members successively actuated by said cam-shaft under control of said controlling member, and a sixth member also actuated by said cam-shaft under control of said controlling member in response to the stop element of the five unit and to the sixth permutation element of the six unit code.

15. In a start-stop signal receiving apparatus, a controlling member successively responsive to the character of received signal elements, a first cam-shaft released in response to the start element of each signal combination to rotate through a predetermined degree, a second camshaft released by the first cam-shaft after a predetermined degree of rotation thereof to rotate in timed relation with succeeding signal elements, and a series of members successively actuated by the second said cam-shaft under control of said controlling members.

16. In a start-top signal receiving and translatingapparatus responsive to signals composed of an invariable start unit followed by either five or six selecting units and an invariable stop unit opposite in character to that of the start unit, the combination of an actuator and an asso ciated permutation member for each selecting element of the signal combination operable to either of two positions according to the signals received, and means under control of the received signals for rendering one of said actuators and its associated permutation member efl'ective to determine the selection when signals containing six selecting units are received and ineffective to determine the selection when signals containing only five selecting units are rceived.

1'1. In a start-stop signal receiving apparatus a series of actuators set in response to received signal elements, a corresponding series of permutation members operable thereby, an additional actuator, a case determining member operable thereby, two transverse bars selectable by particular settings of said series of permutation members and adapted to actuate said case determining bar in opposite directions respectively and means controlled by one of said transverse bars to render said additional actuator inoperative when in one position to move said case determining bar.

18. In a start stop signal receiving apparatus, an actuator settable in one position or another in response to the character of a particular signal element in .each code combination, a case determining bar, a member having limited movement thereon, an intermediate member operable by said actuator when set in one position to move said case determining bar through said member having limited movement thereon, a second intermediate member operable by said actuator when set in the other position to move through an interposable member said case determining bar directly in the opposite direction, two selector bars each operable in response to an individual code signal, means actuated thereby to move said case determining bar in opposite directions respectively, means controlled from one of said selector bars to move said interposable member to a latched position out of operative relation with said actuator, and latch means actuated on operation of said member having limited movement for releasing said interposable member to return into operative relation with said actuator.

19. In a start-stop receiving apparatus, a case determining bar, two selector bars operable in response to two code signals in one code to move said bar in opposite directions respectively, an actuator settable in one or another position in response to the character of a particular signal element in each, signal combination of another code, means operable thereby to move said case determining bar in opposite directions respectively, means actuated by one of said selector bars when moving said case determining bar in one direction to render said actuator inoperative to move the bar in the opposite direction, and means operated by said actuator when set in a position to eiIect a movement of the bar in the first said direction to render the actuator reoperative to move the bar subsequently in the opposite direction.

20. In a start-stop transmitter, the combination of contacts for controlling the signals to be transmitted, means for causing said contacts to transmit permutation code signals consisting of an invariable start unit followed by a predetermined uniform number of selecting units and an invariable stop unit, means for changing said invariable stop unit into a selecting unit, and means controlled by said changing means for introducing a stop unit after each said additional selecting unit has been transmitted.

RONALD GEORGE GRIFFITH.

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