US2344792A

US2344792A - Motor control mechanism for printing telegraph apparatus

Info

Publication number: US2344792A
Application number: US420608A
Authority: US
Inventors: Burdette S Swezey
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1941-11-27
Filing date: 1941-11-27
Publication date: 1944-03-21
Anticipated expiration: 1961-03-21

Description

March 21, 1944. s sw z 2,344,792

MOTOR CONTROL MECHANISM FOR PRINTING TELEGRAPH APPARATUS Filed Nov. 27. 1941 2 Sheds-Sheet 1 FIG.

Y INPZWFOF by 8.5. SWEZEY A7 ORNEV Patented Mar. 21, 1944 MOTOR CONTROL MECHANISM FOR PRINT- ING TELEGRAPH APPARATUS Burdette S. Swezey, Floral Park, N. Y., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application November 27, 1941, Serial No. 420,608

22 Claims. (01. 178--23) This invention relates to printing telegraph i apparatus and particularly to signal responsive control mechanism for the driving motors of telegraph signal receiving printers.

An object of the invention is to improve the reliability of operation and to guard against the accidental or unintentional operation of remote motor-stop control mechanism.

A feature of the invention is that the reception of three signaling code combinations, none of which involves operation of the spacing mechanism of the receiving printer is required to effect the operation of the motor-stop control mechanism, and if any signal involving the operation of the spacing mechanism is received prior to reception of the third code combination, the motorstop circuit control mechanism is disabled.

According to a preferred embodiment of the invention, a telegraph signal receiving printer has a driving motor, the power supply circuit of which includes a pair of circuit controlling contacts. The power supply circuit for the operating motor is complete when the contacts are in closed condition and the opening of the contacts to stop the motor is eifected by an electromagnet, the energizing circuit of which includes two pairs of normally opened contacts. The magnet controlling contacts are closable by individual function levers of the receiving printer, which are operated in response to individual received signals. One of the two function levers is operable in response to its assigned signal, only when the receiving printer is in the upper case or figures shift condition so that two signals are required to effect the operation of that function lever, namely the figures shift signal, preceding the specific function lever signal. The closure of the contacts controlled by that function lever is only momentary.

The other function lever is directly responsive to its assigned signal irrespective of the case shift condition of the receiving printer and a latch is provided for holding the contacts closed.

a The character spacing mechanism of the receiving printer includes a rotatable spacing shaft which is operated in step-by-step manner for character spacing and which has secured thereto a ratchet with which a check pawl cooperates. As is the case in all ratchet and check pawl structures, the ratchet, upon being rotated in stepby-step manner, cams the check pawl outwardly from the axis of the ratchet as the apex of a ratchet tooth moves along the pawl and escapes from its checking edge, and uponthe escape of the tooth apex, the pawl drops into the next notch of the ratchet. The present invention takes advantage of this rocking of the check pawl by the ratchet in that a release or tripelement for the latching mechanism associated with the latchable contact operating function lever is associated with the check pawl and upon any rocking of the check pawl by the ratchet following the latching of the contact operating function lever, the latch. is tripped or released and the function lever is permitted to return to normal position, thus permitting the contacts controlled by it to reopen.

With the foregoing arrangement, the motorstop control magnet can become energized only upon the reception of three code combinations, namely, the code to which the latchable function lever responds, the figures shift code and the code to which the'momentarily operable function lever responds. In the event that an operator, having placed a receiving printer in the figures shift condition by the transmission of the figures shift signal, accidentally transmits the motor-stop function signal, which is the signal to which the momentarily operable function lever responds, the operating motor of the receiving printer will not be stopped because the contacts controlled by the latchable function lever have not been closed and it is extremely unlikely that the signalfor operating the latchable function lever will have been accidentally or unintentionally transmitted in combination with the figures shift signal and the motor stop signal, so that the latchable function lever would not ordinarily be latched in the operated condition preceding the operation of the momentarily operable function lever, except by express intention. With the character spacing mechanism being arranged to release the latchable function lever, any signal which effects the operation of the character spacing mechanism received when the latchable function lever is in latched condition, will cause that function lever to be unlatched and the contacts which it controls will accordingly be opened. Thus if the signal which controls the latchable function lever is transmitted either intentionally or unintentionally, and thereafter a signal involving character spacing is transmitted, the latchable function lever will be unlatched incident to the operation of machine as result of reception of the signal which involves character spacing. The

latchable function lever does not become unlatched upon the reception of the figures shift code because that code does not producea character spacing operation.

A magnet controlled latch is provided for holding the armature of the motor-stop control mag net in the operated condition, so that the motorstop control contacts will remain opened after th motor-stop control magnet has become deenergized, since its circuit is closed only momentarily due to the fact that the motor-stop function lever is a momentarily operable lever. The latching magnet remains energized until a motor start signal is received and the efiect of this signal is to release the latching magnet which in turn unlatches the armature of the motor-stop control magnet and permits the motor-stop contact to be reclosed.

For a complete understanding of the invention, reference may be had to the following detailed description to be interpreted in the light of the accompanying drawings in which:

Fig. l is a diagrammatic perspective View of a telegraph signal receiving printer having motorstop contact control mechanism according to the present invention, together with a schematic electrical circuit view showing the motor-stop and motor-start magnet circuits and associated motor power supply circuit;

Fig. 2 is a diagrammatic view of a remote signal transmitting station; and,

Fig. 3 is a combined fragmentary diagrammatic perspective view and schematic electrical circuit view of an alternative embodiment of motor-stop control system.

Referring now to the drawings and particularly to Fig. 1, there is shown in that figure the'principal elements of a telegraph signal receiving printer of the type shown in Patent 2,24'l,408, granted July 1, 1941, to A. H. Reiber. The disclosure of this patent is incorporated herein by reference as part of the present specification. The printer shown in Fig. 1 has a driving motor I i, the shaft l2 of which carries a pinion gear 13. Pinion l3 meshes with a gear M sleeved on a type-wheel shaft I6 and interconnected with the shaft l6 through a friction clutch assembly I1. Pinion I 3 also meshes with a gear !3 which is secured to a shaft l9 to which continuous rotation is imparted gear is from motor H. A gear 2! is secures to gear 18 and there is meshed with the gear 2], a gear 22 which is Secured to a shaft 23. The shafts l6, l9 and 23 perform all of the mechanical operations in the receiving printer. I

Shaft l9 has secured thereto the driving portion 26 of a positive clutch with which a driven portion 27 slidable on shaft I9 is engageable. Driven clutch portion Zl is slidably keyed to a cam assembly sleeve 28, is urged to move into engagement with driven portion 26 by compression spring 29 and is normally restrained from engagement with driven portion 26 by a clutch throw-out lever 3| pivoted at 32. Cam assembly sleeve 23 has secured thereto a function bail cam 33, a type-wheel elevating control cam 34 and a combined printing and operating bail cam 316.

At its upper end the shaft 59 has sleeved thereon a Selector cam assembly which is driven by shaft l9 through a friction clutch assembly including flanges 33 secured to cam assembly 3?, friction discs 39 and discs M secured to shaft I15. A compression spring 42 compresses the friction discs 39 between the discs Al carried by shaft 19 and the flanges 33 of cam assembly 3 and develops a gripping force tending to cause the cam assembly 3i to rotate with shaft [9.

The cam assembly 37 has a plurality of spirally arranged cam projections 53 which serially impart counter-clockwise rocking movement to in-' dividual sword-lever bell cranks 44 pivoted at $3.

Each of the sword-lever bell cranks A l has articulated thereto a selector sword-lever 47 which has spaced abutment arms Q53. A selector lever which is controlled by a selector magnet 5! is provided with depending arms 52. the distance between which is less than the distance between the abutment arms 58 of sword lever if, so that when selector lever 49 is in extreme counterclockwise position, its right-hand depending arm 52 will be in alignment with the righthand abutment arms 45 of all of the sword levers 4'! and its left-hand depending arm 52 will be out of alignment with the left-hand arms of all of the sword levers 4'6. When selector lever 49 moves into extreme clockwise position, its left-hand depending arm 52 comes into alignment with the left-hand abutments Q8 of all of the sword levers 4'! and its right-hand depending arm 52 moves out of alignm nt with the rightdiand abutment 63. When selector lever $9 is in extreme counterclockwise position and a sword-lever bell crank M is operated, its associated sword lever 4'! will be retracted leftwardly as viewed in Fig. 1 and the sword lever 47 will be moved into extreme clockwise position, whereas if the selector lever is is in extreme clockwise position, the sword lever i? will be moved into extreme counterclockwise position, which is the position shown in Fig. 1.

Each of the sword levers d? cooperates at its foremost or free end with a transfer lever 53 which is pivoted at 54 and is rocked into extreme clockwise position when its associated sword lever il is restored to normal position. after having been retracted by bell crank G l and rocked into extreme counter-clockwise position by selector lever 49. Conversely a transfer lever 53 is rocked into extreme counter-clockwise position when its asso ciated sword lever 47 is returned to normal position after having been rocked into extreme clockwise positions by selector lever '59. Each of the transfer levers 53 is articulated to one arm of a code disc bell crank lever 55, the other arm of which is articulated to a code disc 5?.

There are as many of the code discs 5'? as there are significant impulses in the code combinations to be received by the printer, which in well-known types of printing telegraph apparatus is five or six code impulses, and code discs are arranged in a stack coaxially of the type-wheel shaft [6, the shaft 56 extending through the assembly of code discs. The code discs 51 are notched permutationally around their edges to control the selection of a plurality of selectable 'pins 58. When an alignment of notches in the code discs 51 is presented to one of the pins 58, the upper end of the pin is permitted to move inwardly radially of the code discs into the path of a typewheel stop arm 59 carried by and secured to type-wheel shaft [6. Rotation is imparted to type-wheel shaft I6 through the friction clutch assembly I! from gear l4 and when stop arm 59 encounters a selected pin 58, the arm is arrested, thusarresting shaft I6. Type-wheel shaft It has slidably keyed near the upper end thereof a type wheel 6!. The orientation of type wheel 5| with respect to stop arm 59 is such that when arm 59 is arrested in position to eifect the selection of a particular character for printing, that character on the periphery of the type wheel is presented in printing position.

In addition to the cam projections 43, the selector cam assembly also has a cam projection 62 for rocking in clockwise direction an arm 63 carried by a clutch throw out lever 64 pivoted at 66. Lever 64 has at 1155 lower end a clutch throwout arm 61 which cooperates with the driven portion 68 of a positive clutch mechanism carried by the shaft 23. The driving portion 69 of the clutch mechanism is positively connected to gear 22. Driven portion 68 of the clutch is slidable axially of shaft 23 under the influence of a compression spring I! for engagement with driving portion 69, is normally restrained from engagement with the driving portion by clutch throw-out arm 61 and is slidably keyed to a cam sleeve 12 carried by shaft 23.

Cam sleeve I2 has secured thereto a type-wheel elevating cam 13 and a cam I4 for rocking clutch throw-out lever 3| in clockwise direction to permit the engagement of driven clutch element 2! with driving clutch element 26 carried by main shaft I9. The orientation of cam I4 on sleeve I2 is such that the cam operates clutch'throwout lever 3! near the end of a revolution of sleeve I2. It should be noted that the orientation of cam projection 62 on selector cam assembly 3! is such that it rocks clutch throw-out lever 64 near the end of a revolution of the selector cam assembly 31 and therefore about the time that the last of the sword levers 4! has been set in selective position under the control of selector lever 49. v I

Type-wheel elevating cam 'I3 is engaged by a follower arm I6 secured by means of screws 11 to a lever I8 pivoted at "I9. At its free end the lever I8 is connected by a tension spring 8! to a type-wheel supporting frame 82 which is movable vertically and is guided by pin 83 disposed in slot 84 and by stud 86 extending throughrboss 81. The type-wheel supporting frame 82 has at the top thereof a horizontally disposed platform 88 which engages the hub of type-wheel 6! and moves the type-wheel upwardly and downwardly on shaft I6 as frame 82 is liftedand lowered;v

When sleeve I2 is rotating after having been released for rotation by clutch throw-out lever 64, the cam I3 operates upon follower arm I6 to rock lever I8 in counter clockwis e direction, thus tending to distend tension spring 8!. The spring 8'! acts upon type-wheel supporting frame 82 to lift the type-wheel 6! to bring the type elements carried on its periphery into' printing position.

At the time that cam I3 has rocked lever I8 into extreme clockwise position, cam I4 operates clutch throw-out lever 3! to permit engagement of driven clutch portion 2! on main shaft I9 with driving portion 26 whereby rotation is imparted to main cam assembly sleeve 28. G am 34 carried by sleeve 28 has in its under surface a channel which is entered by a cam follower 9! carried by a cam follower lever 92 which is also secured to lever Hi. In the rest position of cam 13,. the apex thereof has moved out of engagement with follower armI6 so that lever I8 seeks tov return to extreme clockwise position. However, the time of initiation of rotation of cam sleeve 28 is such with respect to the rotation of cam sleeve I2 that before cam 13 comes torest, the channel in cam 34 assumes control over lever I8 and holds the lever in extreme counter-clockwise position. Lever I8 is held in this position until printing from type-wheel 6! has been accomplished under the control of printing cam 36, as

is fully disclosed in the hereinbefore identified patent. whereupon the channel in cam 34 permits lever I8 to return to extreme clockwise.

position and controls the return of the lever to this position so that such return is not violent.

Since the type-wheel 6! has two rows of type faces around the periphery thereof, it is necessary to stop the upward movement of type-wheel 6! when the type-wheel has reached either of two elevational positions to present the proper row of type faces in printing position. This is controlled by a slide 93 which is slidably mounted on

pins

83 and 94. Slide 93 is provided with a stepped aperture 96 which affords two arrestment surfaces 9! and 98 for an arm 99 secured to typewheel supporting frame 82 and extending into aperture 96. The movement of slide 93 from one to the other of its two positions to bring

stop surface

91 or 98 into the path of arm 9, is controlled by the shift and unshift mechanism of the printer, as is fully disclosed in the Reiber patent! When the upward movement of type-wheel sup-' porting frame 82 is arrested by stop surface 91, the type-wheel will be arrested in its vertical movement with the upper row of type faces presented in printing position and this is the socalled unshift or letters position. When frame 82 is arrested by stop surface 98, the type-wheel is arrested in position to present the lower row of type faces in the printing position and this is the shift or figures position. The movement imparted to lever I8 by cam I3 is somewhat more than enough to lift the type-wheel to its upper position of arrestment and spring 8! yields when the typewheel is arrested in either of its two elevational positions.

The printing cam 36 has in the upper surface thereof a channel ID! in which is disposed a cam follower I02 carried by a lever I83 pivoted on a rod I04. Lever I03 has associated therewith arm I which carries apivot rod I85 which supports a plurality of vertically spaced floating levers IIII. Each of the floating levers I9! has an arm I 88 extending toward type-wheel shaft I6 and a sleeve I09 carried by and secured to the type-wheel shaft l6 has a plurality of abutment pins III in various angular positions corresponding to selective stop positions of the type-wheel at which functions are to be selected. In a selective position of the type-wheel corresponding to the selection of a function, one of the abutment pins I! I is aligned with the arm I08 of one of the floating levers I81.

The free end of each of the floating levers I01 is disposed at the left side of one arm of a lever II2 which is pivoted at H3 and is connected by a tension spring II4 to a lever II6 also pivoted at H3. Each of the levers Il a has its free end in abutment with a function bar III and all of the function bars III are pivotally supported by a rod II8 carried by the right-hand arm of a bell crank H9 pivoted at I2I. The left-hand arm of bell crank H9 has at its free end a cam follower roller I22 which engages function cam 33 The function bars III are biased by tension springs I23 into engagement with the free ends of levers II6.

Mounted at the rearor free ends of function bars II! is an assemblyof function levers I26 pivoted on rod I 21. In close proximity to each of the function levers I26 is a latch lever I28 also pivoted on rod I2I'and having its right-hand end curved forwardly to extend toward the free end of the associated function bar III at the right-hand side thereof. Each of the latch levers I28 is biased in clockwise direction by a spring 129 and. a stop pin I3! determines the idle or rest position of the latch lever I28, i I

For the purposes of the present invention, the

lower function lever I26 is arrangedto close a pair of normally open contacts i132 and the upper function lever I26 is arranged to close a pair of normally open contacts I33.

For the purpose of illustrating the operation of the function mechanism, let it be assumed that a code combination has been received which will cause the selection of a type-wheel stop pin 58 to arrest the type-wheel in position to effect the selection of the lower function bar I I1. Near the end of the rotation of selector cam assembly 31 clutch throughout lever 54 will be operated to permit the engagement of the positive clutch which comprises clutch elements 68 and E9 on the front shaft of the printer. Rotation will -be imparted to cam sleeve I2 and cam I3 will rock lever IS in counter-clockwise direction to effect the elevation of type-wheel 6| to printing position. Since the selection of a function is ordinarily not accompanied by the printing of acharacter, the type-wheel will have a blank or non-printing element presented to the printing mechanism, when the rotation of the type-wheel is arrested by the particular pin 58 selected.

By the time the front cam sleeve 12 has completed its cycle of rotationand earn it has operated clutch throw-out lever 3i, type-wheel 6| will have rotated to the new selected position and will have been arrested. Upon the operation of clutch throw-out lever 55, the positive clutch comprising clutch elements 2% and 2! on the main shaft will become engaged and rotation will be imparted to the main cam assembly sleeve 28. Printing is controlled by a cam follower (not shown) which engages the periphery of printing cam 35 but since a blank portion of the typewheel 6| is presented to the printing mechanism; no character will be printed. About the time that the printing operation occurs, cam groove IdI in cam 35 rocks bell crank I83 sharply in counterclockwise direction and then restores it to extreme clockwise position. Since the floating levers I! are carried by the free end of arm I of bell crank H13, the foremost or left-hand ends of the floating levers It! will be moved through an arc in counter-clockwise direction. Those which find no type-wheel shaft abutment pins I II aligned with their arms I68 will rock idly about the point of engagement of the free ends with their associated levers I I2 and will not impart movement to those levers. With an abutment pin aligned with the arm Hi8 of the lowermost of the floating levers I 9'! as shown in Fig. '1, the arm IEIB will be brought into engagement with the abutment pin IH which will serve as a fulcrum for that particular floating lever I97 and as the counterclockwise movement of the foremost or left-hand end of the lever H31 continues, the lever will be rocked in clockwise direction upon the end of the abutment pin III as a fulcrum and the free end will be moved to the right as viewed in Fig. 1, thus rocking the associated lever in counter-clockwise direction. Due to the interconnection of levers H2 and IIS by tension spring I54, the lever IIS will also be rocked in counter-clockwise direction and will rock the associated function bar I I"! in clockwise direction if the function lever I i! is not then blocked against clockwise rotation under circumstances which will be described later. It should be noted that if the function bar is blocked at this time the associated lever I IE will also be blocked and spring IId wiil yield and take up the motion of lever I I2.

Assuming that the lowermost function bar I ll is not blocked at this time, its free end will more rightwardly. About the time that floating levers III! are operated, which operation is momentary, cam 33 starts to rock bell crank I I9 counterclockwise to move function bars I I] endwise rearwardly (rightwardly as viewed in Fig. 1). Just as the floating levers become fully operated the free ends of function bars I I? move past the ends of the forwardly curved portions of latches I28. The selected one of the bars H1, in the present description the lowermost, has its free end to the right Of the end of the latch, while the unselected bars have their free ends to the left of their latches. The selected bar is now blocked out of normal position by its latch I23, and cam groove I06 restores the floating levers Ill! to normal. If the timing of the operation of floating levers I01 and of the reciprocation of bars I i? should be so close that the free end of a bar III which is being selected should strike the end of its latch, this will not prevent the latching of the bar I", because the free end of the latch is out on a diagonal, and the bar I I! will continue to be moved reciprocably and clockwise, camming latch I28 in counterclockwise direction sufficiently for the free end of bar II! to clear the forwardly extending portion of the free end of latch lever I28. As soon as the free end of function bar I" has moved to the right of the forwardly extending free end of latch I28, the latch will be restored by spring I29 to normal position in engagement with stop pin I3I with its forwardly extending end to the left of the free end of function bar II! and blocking the return of that bar to normal position. The operation of floating levers I01 need be only of sufiicient duration to insure that a function bar II'I associated with a floatin lever I01 which finds an abutment pin III presented to it will become latched by its associated latch I 28.

As cam sleeve 28 rotates,

cams

34 and 33 also rotate. The cam 34 which has assumed control of the type-wheel elevating lever 18 by means of the follower 9| holds the type-wheel in elevated position until after the printin mechanism has been operated under the control of cam 36 and thereafter permits lever I8 to return to normal position in a smooth steady motion spread over a considerable portion of the cycle of rotation of cam 34. Cam 33 has a gentle rise and a sharp drop-01f near the end of its cycle of rotation and during the major portion of the cycle of rotation of cam 33, it rocks bell crank H9 in a smooth gentle motion in counter-clockwise direction thus reciprocating the function bars II'I endwise toward their function levers I25. The

' function levers I26 have an offset immediately to the left of the free ends of the latches I28 so that function bars II! which have not been selected and latched will impart no movement to their associated function levers I26. A selected function bar, which has been assumed to be the lowermost bar II'I shown in Fig. 1 upon being moved endwise encounters and rocks its associated function lever I26 in counter-clockwise direction whereby the left-hand end of the lowermost lever I 26 will close contacts I32.

In accordance with the present embodiment of the invention, the left-hand arm of the lower function lever I26 extends beyond the contacts I32 and near its free end th undercut end of a latching bell'crank I36 rests upon the lower function lever I26. Latching bell crank I36 is biased in counter-clockwise direction by tension spring I31 and when the function lever I26 is rocked in counter-clockwise direction by its function bar II1, the undercut portion of latching bell crank I36 drops into blocking relation to the left-hand arm of the lower function lever I26 thus latching the function lever in operated or extreme counter-clockwise position and maintaining contacts I32 closed.

The upper function lever I26 which is selectable in similar manner by an abutment pin III in a different angular position on the type-wheel sleeve I69, is not provided with a latch and accordingly the contacts I33 are closed only momentarily for the reason that when cam follower roller I22 drops off the apex Of function cam 33, bell crank I I9 returns to normal position and retracts the function bars II1 to their normal r unoperated position.

The upper function bar H1 is provided with a laterally projecting finger I4I adjacent to which is disposed in a plane just clear of the end of finger I4I when the function bar is in normal position, a blocking plate I42 carried by an arm extending downwardly from the shift and unshift controlling slide 93. When the printer is in the shift condition with the shift controlling slide 93 in extreme 1eft-hand or forward position to present the upper stop surface 98 in the path of stop arm 99 carried by type-wheel supporting frame 62, function blocking plate I42 is disposed to the left of the end of finger I4I of the upper function bar II1 out of blocking relation thereto. However, when the printer. is in the unshift condition with the shift controlling slide 93 in its right-hand or rearward position, so that the lower stop surface 91 is in the path of stop arm 99, plate I42 will have moved into the path of arcuate movement of finger I4I of the upper function bar II1 so that the function bar will be blocked and cannot be rocked clockwise by its floating lever I61 and latched by its latching lever I28. It follows from this that when the printer is in the unshift condition, the upper function bar II1 which controls the operation of the non-locking contact I33 cannot be selected and operated and that a figures shift signal must have been received and have placed the printer in th shift condition in order for the contacts I 33 to be operated.

The character spacing mechanism of the receiving printer shown in Fig.1 includes a pinion shaft I46 which, as is fully disclosed in the Reiber patent, steps the platen carriage by means of a pinion carried by shaft I46 meshing with a rack carried by the platen carriage, a spacing ratchet I41 carried by the pinion shaft I46, and a spacing pawl I48 for operating ratchet I41, pivotally supported by the rod III! which supports function bars II1 so as to be reciprocable by bell crank II9 operated by function cam 33. A holding or check pawl I49 engages ratchet I41 andprevents reverse rotation of the ratchet when pawl I48, having advanced the ratchet one step, is retracted to pick up the next tooth on the ratchet I41 in preparation for the next character spacing operation. Check pawl I49 holds ratchet I41 by entering the space between two teeth of the ratchet. 3

It will be apparent that when ratchet "I41 is advanced-one step by spacing pawl I46, the check pawl I49 is cammed through a smallangular disnext space. Advantage is taken of this slight rocking of check pawl I49 to release latch I36 for the lower function lever I26, by the attachment to the check pawl I49 of a latch tripping lever arm I5I. When latch I36 is not in blocking relation to the lower function lever I26, its upwardly extending arm is held out of engagement with tripping lever I5I and arm I5I engages it only near the end of the stroke of check pawl I49 and lifts latch I36 clear of the lower function lever I26, which at this time is an idle operation. The latching of the lower function lever I26 is accompanied by a slight counterclockwise movement of latch I36, which brings the end of its upwardly extending arm substantially into engagement with 'arm I5I carried by check pawl I49. After the lower function lever I26 has become-latched, the next operation of the receiving printer which involves character spacing, will cause the check pawl I49to rock latch I36 free of the lower function lever I26, permitting the function lever to return to normalposition and permitting contacts I32' to open.' A character spacing operation takes place incident to the printing of any character and also in're sponse to the word spacing signal combination. It ordinarily does not take place incident to functions such as shift, unshift, carriage "return, line feed, motor stop, signal bell operation, and break, and as is fully disclosed in the Reiber patent, means is provided for moving the spacing pawl I48 clear of the spacing ratchet I41 incident to the selection of any function so that s acing will be suppressed when the function cam 33 operates bell crank II9, it being understood that spacing pawl I48 is reciprocated, each time that bell crank H9 is operated.

Contacts I32 and I33 are associated with motor control mechanism which maybe of the type shown in Patent 1,964,268 granted June 26,1934, to O. A. Morgenstern. The disclosure 'of'that patent is incorporated herein by reference as a part of this specification. The motor control mechanism is shown in the lower right-hand corner of Fig. l.

Referring now to that portion of Fig. 1, an electromagnet Ifii has an armature I62 which controls three pairs of contacts I63, I64'and I66. When the armature I62 of electromagnet I6'I is in the released position, contacts I63 and I66 are closed and contacts I64 are opened. Conversely when the armature of electromagnet I 6I' is in the attracted position, which is the condition shown, contacts I63 and I66 are opened and the contacts I64 are closed. The energizing circuit for electromagnet I6I extends from the positive terminal of battery I61 through the winding of electromagnet I6I, conductor I68 to one of the normally opened contacts I33. The other of these contacts is connected by conductor I69 to one of the normally opened contacts I32 and the other of the contacts I32 is connected by conductor H! to the negative terminal. of battery The contacts I32 and I33 are thus observed to be in series in the energizing circuit of electromagnet I6I and both pairs of contacts must be closed in order to complete the energizing circuit for the magnet. I I

The contacts I66 controlled by electromagnet I6I are the motor-control contacts and the righthand one of the contacts I66 is connected to the positive terminal of battery I61 while the left- Y hand one of those contacts is connected through conductor I12, driving motor I I and conductor I13 to the negative terminal of battery I61.

Let it be assumed that armature I62 of electromagnet I6! is in the released position so that contacts I66 are closed, and power is being applied to motor I I, through conductors I12 and I13 and that it is desired to stop motor II by the transmission of appropriate signals to selector magnet of the receiving printer. The stopping of motor II is accomplished by the opening of contacts I66 through the energization of electromagnet I6I, which necessitates the closure of contacts I32 and I33 in such manner that both pairs of contacts shall be closed at least for an instant sufficient to effect the energization of the electromagnet. It will be apparent that contacts I32 must be closed before the contacts I33 since the latter are non-locking and close only momentarily. The closure of contacts I32 necessitates the selection and operation of the lower function bar I I1 and since the selection of this function bar is not restricted by the shift and unshift mechanism, it is always responsive to the reception of its assigned signal irrespective of the shift or unshift condition of the printer. According to one embodiment of the invention it has been proposed to make the lower function bar II1 responsive to the blank or all spacing signal. The blank signal function is ordinarily not restricted as to the shift or unshift condition of the printer but it could be restricted if desired for any reason so as to be selectable only in the shift condition or only in the unshift condition of the printer. Responsive to. the blank or all spacing signals, the lower function bar II1 becomes selected and operated and contacts I32 become closed and are retained in this condition by latch I36.

In order to select the upper function bar II1, it is first necessary to place the shift control slide 63 in the shift or extreme left-hand position in order to unblock the finger I il of the upper function bar. This is accomplished by the reception of the shift signal. After the upper function bar II1 has been unblocked, the motor stop signal will efiect the selection of that function bar which upon being operated will close contacts I33 momentarily to complete the energizing circuit for electromagnet I6I which will attract its armature to open its contacts I66,

thus opening the energizing circuit for motor II. The apparatus shown in Fig. 2 includes a latch for holding the armature I62 of electromagnet I6I in the attracted position as will presently be described, whereby only momentary closure of contacts I33 with contacts I32 latched in the closed condition is necessary to effect the interruption of the motor circuit.

From the foregoing it will be observed that stopping of the motor II may be accomplished by the transmission to the receiving printer of three signal combinations which have been identified herein as blank, shift and motor stop. Since the blank function bar is operable independently of the shift or unshift condition of the printer, it will be apparent that stopping of the motor will be accomplished by the transmission'of these signals in the order blank, shift and motor stop or in the order, shift, blank and motor stop. If the printer disclosed herein did not include the latchable contacts I32 but only the momentarily operable contacts I 33, unintentional operation of the motor-stop mechanism could result from accidental striking of the motor-stop signal key in a keyboard transmitter after a figures shift signal had been transmitted for preparing the printer to print figures or punctuation marks. With the contacts I32 included in the system, it is extremely unlikely that an operator would transmit the blank or preparatory signal combination before or after a shift signal intended to place the printer in condition to print figures or punctuation marks. whereby the accidental striking of the motorstop signal key would result in stopping of the motor II. The additiona1 preparatory function in connection with the motor-stop function reduces to a minimum the likelihood of unintentional stopping of the motor I I.

The release of the latch for the lower function lever I26 by operation of the spacing mechanism of the printer provides for restoration of the contacts I32 to normal or open condition by remote control and without the necessity of attention locally by an attendant. Since the contacts 33 close only momentarily, the contacts I32 may remain closed without having any further effect on electromagnet I6I. Furthermore, the transmission of the blank signal combination or of a break signal for a purpose other than preparation for a motor-stop signal will effect the closure and latching of contacts I32 but this will have no eifect on electromagnet I6! unless the shift and motor-stop signals are transmitted while contacts I32 remain closed. The transmission of any signal combination which involves character spacing after contact I32 has been latched in closed condition will release the latch and restore the contacts to normal open condition.

A distant telegraph station for transmitting signals to the printer shown in Fig. 1 is shown diagrammatically in Fig. 2. At the remote station the selector magnet I16, transmitting contacts I11 and break key I18 are connected in series and a circuit may be traced from one end of this series circuit through line conductor IE9, signaling battery I8I, local selector magnet 5!, transmitting contacts I83, conductor I85, winding of magnet I88, break key I81 and line conductor I86. to the other end of the series circuit at the remote station. The left-handone of the contacts I64 and the right-hand one of the contacts I63 are connected to the conductor I83. The right-hand one of the contacts I64 is connected by conductor I82 to the opposite terminal of transmitting contacts I83 from that to which conductor I84 is connected, so that when contacts I64 are closed, a shunt circuit will bridge the transmitting contacts I83 and those contacts will be ineffective to impress signals on the communication circuit. The left-hand one of the contacts I63 is connected to the opposite terminal of magnet I86 from that to which conductor I84 included in the communication circuit is connected, so that when contacts I63 are closed magnet I88 will be shunted out of the communication circuit and accordingly will be deenergized.

When the armature I 62 of electromagnet I6I is in the released position, contacts I66 are closed so that motor II is in operation, contacts I64 are opened and contacts I63 are closed. A signaling circuit may then be traced from the transmitting contacts of the station in Fig. 2 through selector magnet I16 at that station, line conductor I19, battery I8I, selector magnet 5| at the station in Fig. 1, transmitting contacts I83, conductor I84, closed contacts I63, break key I81 and line conductor I86 to the other end of the series circuit at the station in Fig. 2. The winding of electromagnet I88. is connected acrossthe contacts I63, as previously stated, so that with those contacts closed, the winding of electromagnet I88 is short-circuited. Since contacts I64 are now open, transmitting contacts I83 are not shunted, and they may be operated to transmit signals. When the combination of signals which will effect a motor-stop operation is transmitted from the station in Fig. 2 and is received by the selector magnet 5| in Fig. 1, eleotromagnet I6I becomes energized and attracts its armature. Thereupon contacts I66 become opened to interrupt the operating circuit of motor II, contacts I64 become closed and contacts I63 become opened. Contacts I64 reestablish the shunt across the transmitting contacts I83 and contacts I63 remove the short circuit across the i winding of magnet I88 which, being now included in the communication circuit, becomes energized by the current which flows during the rest condition of the system.

As is fully disclosed in the Morgenstem patent, the armature I9I of magnet I88 has associated with it a lever I92 supported on the same pivot as the armature I9I, biased by spring I93 to follow armature I9I in counter-clockwise direction and held in spaced relation to the armature by 3 finger I94. Lever I92 extends through an aperture in the armature I62 of electromagnet I6I and is provided with a lug I96 for retaining armature I62 in the attracted position when armature I9I is held attracted by electromagnet I88. The lug I96 serves as a primary latch for thearmatureIBZ. Armature I9I of magnet I88 is provided with a notch I91, the left-hand edge of which is slightly to the left of the right-hand edge of lug I96. The notch I91 serves as a secblockedby notch I9'Iv in armature I9I so that" armature I62 merely escapes from lug I96 but is not fully released as long as the line circuit remains opened. Upon the, reclosure of either of the break keys which had been opened, armature I9I is again attracted and releases the armature I6I which closes contacts I68 to restart motor II and close contacts I63 to short circuit the winding of electromagnet I88 but armature I62 of magnet I6I holds the armatur I9I in the attracted position mechanically. By this operation of opening and reclosing the communication circuit, the station of Fig. 1 is fully restored to condition for intercommunication with the station of Fig. 2.

In Patent 1,965,383, granted July 3, 1934, to

C. C. Lane, there is shown a motor control circuit different from that disclosed in the Morgenstern patent with which the present invention is adapted to cooperate and the disclosure of the Lane patent is incorporated herein by referencemotor circuit.

Fig. 3 shows the adaptation of the present invention to cooperate with the motor control circuit shown by Lane. Like reference characters"- have been employed to designate elements in Fig.

open, in Fig. 3 the contact pairs 20I and 202 are normally closed and the function levers I26 are operable to open the contacts, the contacts 20I being held open by latch I36 and the contacts 202 being opened momentarily. A relay 263 has one end. of its winding connected to one terminal of battery 204 and the other terminal connected to one spring of a normal-1y open, non-locking start key 266 the other spring of which is connected to the other terminal of battery 204. One terminal of motor II is connected to the lower front contact of relay 203, the cooperating armature of which is connected to one terminal of battery 204 and the other terminal of motor I I is connected to the other terminal of battery 204. A holding circuit for the relay 203 becomes closed upon the operation of relay 203 from one terminal of battery 204 through the winding of relay 203, upper armature and front contact of that relay, normally closed contacts 20I and 202 in parallel to the other terminal of battery 204.

The motor II is started by momentary closure of start key 206 which completes the energizing circuit for relay 203 which operates to close the motor circuit through its lower armature and front contact and to close its holding circuit through the upper armature and front contact and through the normally closed contacts 20I and 202. In order to stop the motor II the lower function lever I26 in Fig. 3 which corresponds to the lower function lever I26 of Fig. 1 is operated in the manner hereinbefore described and the function lever opens the contacts 20I and becomes latched by the latch I36. The holding circuit for relay 203 is not thereby interrupted as it remains closed through the contacts 282. After the lower function lever I26 has become latched the upper function lever I26 which corresponds to the upper function lever shown in Fig. l is momentarily operated in the manner heretofore described to open momentarily the contacts 202.

' The opening of contacts 202 with the contacts 2Ill latched 'open interrupts the holding circuit for relay 203 which releases, and interrupts the circuit of motor I I at the lower armature and front contact of the relay. Motor II may be restarted by momentarily closing the start key I96 or, alternatively, by signalresponsive remote control as is fully disclosed in the Lane patent.

Although a specific embodiment of the invention has been shown in the drawings and described in the foregoing specification, it is to be understood that the invention is not limited to such specific embodiment but is capable of modification and rearrangement without departing from the spirit of the invention and within the scope of the appended claims.

What. is claimed is:

1. In a printing telegraph apparatus including a character spacing mechanism, a driving motor for said printing telegraph apparatus having an energizing circuit, means for opening and closing said energizing circuit, means including two sets of normallyopen contacts in series for actuating said motor circuit opening and closing means to open said circuit, means responsive to a predetermined received signal for closing one ofsaid sets of contacts, means for retaining saidone r set of contacts closed, means responsive to an- .other predetermined received signal for closing the other of said sets of contacts, andmeansoperated by said spacing mechanism for releasing said retaining means to disqualify said motor circuit opening and closing means against opening said circuit.

2. In a printing telegraph apparatus including a character spacing mechanism, a driving motor for printing telegraph apparatus having an energizing circuit, means for opening closing said energizing circuit, means including two sets of normally open contacts in series for actuating;- said motor circuit opening and closing means to open said circuit, means responsive to a predetermined received signal, for closing one of said of contacts, means for retainin said one set contacts closed, means responsive to another predetermined received signal for closthe other of said sets of contacts, and means operated by said spacing mechanism when an operation thereof intervenes the operation of said two signal responsive for releasing said retaining means to disqualify said motor circuit opening and closing means against opening said circuit in response to the closure of said other set of contacts.

3. In a printing telegraph apparatus including a character spacing mechanism, a driving motor for said printing telegraph apparatus having an energizing circuit, means for opening said motor energizing circuit, means including an electrical circuit normally open at two points for operating said motor energizing circuit opening means, means responsive to a predetermined received signal for closing said normally open circuit atone of said points, means for retaining said circuit closed at said point, means responsive to another predetermined received signal for closing said normally open circuit at the other point, and means operated by said spacing mechanism intervening the operation of said two circuit closing means for releasing said retaining means to disqualify said motor energizing circuit opening means against operation in response to the operation of the circuit closing means at said second point.

4. In a printing telegraph apparatus including a character spacing mechanism, electrical circuit controlling means, means responsive to a predetermined signal for operating said circuit controlling means, means for retaining said circuit controlling means in operated condition, and means operated by said spacing mechanism for releasing said retaining means.

5. In a printing telegraph apparatus including a character spacing mechanism, electrical circuit controlling means, means responsive to a predetermined signal for operating said electrical circuit controlling means, means for latching said operating means in operated condition, and means operated by said spacing mechanism for releasing said latching means to restore said electrical circuit controlling means to initial condition.

6. In a printing telegraph apparatus, a character spacing mechanism including a spacing ratchet, an operating pawl therefor and a check pawl therefor, means for operating said operating :pawl cyclically, electrical circuit controlling means, means responsive to a predetermined signal for operating said electrical circuit controlling means, means for latching said operating means in operative condition to retain said electrical circuit controlling means operated, and means associated with said check pawl and operable thereby upon operation of said ratchet by said operating pawl for releasing said latching means to ill disable said operating means and said electrical circuit controlling means.

7. In a printing telegraph apparatus, a character spacing mechanism including a spacing ratchet, an operating :pawl for said ratchet and a check pawl for said ratchet, a driving motor for said printing telegraph apparatus having an energizing circuit, means for opening said energizing circuit, means including two sets of normally open contacts in series for actuating said motor circuit opening means, means responsive to a predetermined received signal for closing one of said sets of contacts, means for retaining said one set of contacts closed, means responsive to another predetermined received signal for momentarily closing the other of said sets or contacts to operate said motor circuit opening means, and means associated with and operable by said check pawl upon rotation of said spacing ratchet by said operating pawl for disabling said retainingsecond-mentioned contact closing means to be operated, means responsive to a third predetermined received signal for operating the secondmentioned circuit closing means, and means operated by said spacing mechanism for releasing said retaining means to disable said actuating means.

9. In a printing telegraph apparatus including a character spacing mechanism, a driving motor having an energizing circuit, means for opening said energizing circuit, means including two sets of normally open contacts in series for actuating said motor circuit opening means, means responsive to a predetermined received signal for closing one of said sets of contacts, means responsive to another predetermined signal for closing the other of said sets of contacts, means presentable in either of two positions in response to other predetermined signals for blocking said second-mentioned contact closing means in one of said positions and for unblocking said contact closing means in the other of said positions, and means operated by said spacing mechanism for releasing said retaining means to disable said actuating means.

10. In a printing telegraph apparatus including a character spacing mechanism, a driving motor for said printing telegraph apparatus having an energizing circuit, means for opening and closing said circuit, means including two setsof contacts operable conjointly to cause said circuit opening and closing means to open said circuit, means responsive to a predetermined received signal for operating one of said sets of contacts, means for maintaining said one set of contacts operated, means responsive to another predetermined received signal for operating the other of said sets of contacts, and means operated by said spacing mechanism for releasing said retaining means to disqualify said motor circuit opening and closing means against opening said circuit.

11. In a printing telegraph apparatus including a character spacing mechanism, a driving motor for said printing telegraph apparatus having an energizing circuit, means for opening and closing said circuit, means including two sets of contacts operable conjointly to cause said circuit;

opening and closing means to open said circuit, means responsive to a predetermined received signal for operating one of said sets of contacts, means for maintaining said one set of contacts operated, means responsive to another predeter mined received signal for operating the other of said sets of contacts momentarily, and means operated by said spacing mechanism for releasing said retaining means to disqualify said motor 'means responsive to another predetermined received signal for opening the other of said sets of contacts, and means operated by said spacing mechanism for releasing said retaining means to disqualify said motor circuit opening and closing means against opening said circuit.

13. In a printing telegraph apparatus including a character spacing mechanism and a signal controlled case shift mechanism having two selectively effective conditions, a driving motor for said printing telegraph apparatus having an energizing circuit, means for opening and closing said circuit, means including two sets of contacts operable conjointly to cause said circuit opening and closing means to open said circuit, means responsive to a predetermined received signal for operating one of said sets of contacts, means for maintaining said one set of contacts operated, means responsive to another predetermined received signal for operating the other of said sets of contacts, means associated with said case shift mechanism and effective when said case shift mechanism is in a particular one of its effective conditions for rendering one of said contact operating means inoperative, and means operated by said spacing mechanism for releasing said retaining means to disqualify said motor circuit opening and closing means against opening said circuit.

14. In a printing telegraph apparatus including a character spacing mechanism and a signal controlled case shift mechanism having two selectively effective conditions, a driving motor for said printing telegraph apparatus having an energizing circuit, means for opening and closing said circuit, means including two sets of contacts operable conjointly to cause said circuit opening and closing means to open said circuit, means responsive to a predetermined received signal for operating one of said sets of contacts, means for maintaining said one set of contacts operated, means responsive to another predetermined received signal for operating the other of said sets of contacts, means associated with said case shift mechanism and effective when said case shift mechanism is in a particular one of its eifective conditions for preventing signal responsive operation of the last-mentioned of said contact operating means, and 'means operated by. said spacing mechanism for. releasing said retaining means to terminate retention of said one set of contacts in operated condition.

15. In a printing instrumentality, a selectively operable lever having a normal position and an operated position, a retaining latch for'retaining said lever in operated position, af character spacing ratchet, an operating pawl for said ratchet, a check pawl for said ratchet, and means associated with said check pawl for re leasing said retaining latch as said ratchet acts upon said check pawl incident to advancement of said ratchet by said operating pawl.

16. In a printing instrumentality, a selectively operable lever having a normal-position and an operated position, a retaining latch forretaining said lever in said operated position, a character spacing ratchet feed mechanism including a ratchet, an operating pawl and, a check pawl, said ratchet having interdental spaces of sufiicient depth to impart appreciable movement to said check pawl upon advancement of said ratchet by said operating, pawl, and means associated with said check pawl 'for releasing said retaining latch upon being subjected to said movement by said ratchet.

17. In a printing telegraph apparatus having an operating motor and a character spacing mechanism, an energizing circuit for said motor including circuit controlling means, selectively operable means for performing a preparatory operation upon which actuation of said circuit controlling means to open saidmotor energizing circuit depends, means for causing said selectively operable means to remain operated, other selectively operable means for causing said circuit controlling means to open said motor energizing circuit, and means controlled by said spacing mechanism for causing said first-mentioned selectively operable means to be restored to unoperated condition.

18. In a printing telegraph apparatushaving an operating motor and a character spacing mechanism, an energizing circuit for said motor including circuit controlling means, selectively operable means for performing a preparatory operation upon which actuation of said circuit controlling means to open said motor energizing circuit depends, means for causing said selectively operable means to remain operated, other selectively operable means for causing said circuit controlling means to open said motor energizing circuit, and meanscontrolled by said spacing mechanism for causing said first-mew tioned selectively operable means to be restored to unoperated condition, said last-mentioned means when operated following operation of said first-mentioned selectively operable means and preceding operation of said other selectively operable means, being effective to nullify said preparatory operation whereby to prevent operation of said circuit controlling means.

19. In a printing telegraph apparatus having an operating motor and a character spacing mechanism, an energizing circuit for said motor including circuit controlling means, selectively operable means for performing a preparatory operation upon which actuation of said circuit controlling means to open said motor energizing circuit depends, means for causing said selectively operable means to remain operated, other selectively operable means for causing said circuit controlling means to open said motor energizing circuit, and means controlled by said spacing mechan'ism upon the next ensuing operation thereof irrespective of the occurrence or non-occurrence of an operation of said other selectively operable means for causing said firstmentioned selectively operable means to be restored to unoperated condition.

20. In a printing telegraph apparatus, an electrical instrumentality to be operated selectively, means including an electrical circuit normally open at two points for operating said instrumentality, means responsive to a predetermined received signal for closing said circuit at one of said points, means for retaining said circuitclosed at said point, means responsive to another predetermined received signal for closing said circuit at the other point, and means operably effective in response to reception of any one of a plurality of other signals intervening said two predetermined signals for disabling said retaining means to disqualify said instrumentality against operation in response to the operation of the circuit closing means at said second point.

21-. In a printing telegraph apparatus, an electrical instrumentality to be operated selectively, means including an electrical circuit for operating said instrumentality, said circuit hav ing two serially connected means normally bstructing flow of current in said circuit, means responsive to a predetermined signal for conditi'oning one of said serially connected means to passzcurrent in said circuit, means for retaining'said one of said serially connected means conditioned, means responsive to another predetermined received signal for conditioning the other of said serially connected means to pass current in said circuit whereby to cause said instrumentality to be operated by current through said two serially connected means, and means operably efiective in response to reception of any one of a plurality of other signals intervening said two predetermined signals for disabling said retaining means to disqualify said instrumentality against operation upon conditioning of said other of said serially connected means.

22. In a printing telegraph apparatus, an electrical instrumentality to be operated selectively, means including an electrical. circuit for operating said instrumentality, said circuit hav ing two serially connected and normally deactivated circuit closing means, a signal responsive selectable element for activating each of said circuit closing means individually, means for momentarily operating said selectable elements upon selection thereof, means for retaining one of said circuit closing means activated after operation of its selectable element by said operating means, and means operably effective in response to any one of a plurality of other signals intervening those controlling selection of the selectable elements for said circuit closing means for disabling said retaining means to disqualify said instrumentality against operation upon activation of the other of said circuit closing means.

BURDETTE S. SVJEZEY.