US2326386A - Tape-controlling arrangement - Google Patents

Description

Aug; 10, 1943. D. F. NEWMAN TAPE-CONTROLLING ARRANGEMENT Filed Dec. 24, 1938 2 Sheets-Sheet 1 INVENTOR Env/r1 ENEWMHN.

lATI'ORNE S Aug. l0, 1943. D F, NEWMAN 2,326,386

TAPE- CONTROLLING ARRANGEMEN T Filed Deb. 24, y195e 2 sheets-sheet 2' 'lfg 4' INVENTOR A ORNEYS Patented Aug. l0, 1943 TAPE-CONTROLLING ARRANGEMENT David F. Newman, Rockville Centre, N. Y., as-

signor to Trans-Lux Corporation, New York N. Y., a corporation of Delaware Application December 24, 1938, Serial No. 247,717

Claims.

My invention relates to arrangements for controlling a character-bearing tape or web for movement through a projection field.

My a combined printing-projecting arrangement wherein the tapedrawing motor is controlled .in a novel manner so that rotation of the motor armature is discontinued simultaneously with deenergization of the motor operating circuit.

My invention, in a more detailed and preferred application thereof, relates to an arrangement for discontinuing rotation of the motor armature by electro-magnetic action thereon simultaneously as the motor operating circuit is deenergized.

My invention, in another important phase thereof, relates to an arrangement which, by simple manual adjustments, adapts a tape-drawing motor for use either with an alternating or direct current source even though the voltage of such source differs substantially from the voltage requirements of the motor.

Various other objects, advantages and characteristics of my invention will become apparent from the following description.

My invention resides in the tape-controlling arrangements, combinations and improvements of the character hereinafter described and claimed.

For an understanding of my invention and for an' illustration of some of the forms thereof, reference is to be had to the accompanying drawings, in which:

Figure l is an elevational view of a printerprojecting arrangement together with a diagram` matic representation of a motor control circuit;

Fig. 2 is a plan view showing the tape-controlled switch;

Fig. 3 is a. vertical sectional view, partly in elevation, and is taken on the line 3-3 of Fig. 2 looking in the direction of the arrows;

Fig. 4 diagrammatically illustrates the autotransformer of Fig. l and some of its connections as adapted for commercial use; Y

Fig. 5 is a schematic viewillustrating an application of the invention; and

Fig. 6 is a schematic view illustrating another application of the invention.

Referring to the drawings, P represents a suitable printing device such, for example, as a ticker mechanism of the type utilizable in the United States for printing two spaced rows of characters lengthwise on a narrow tape T or, as shown, of the ltype utilizable for printingr` on a tape having a width of more or less, and

invention has particular reference to known in Great Britain under the designation of the Exchange Telegraph Company, Ltd. The type of printer last named prints a single row of characters lengthwise on the tape T, which may be opaquer if desired although, in the form of the invention herein illustrated, said tape T is of the transparent or translucent type and adapted, therefore, for through projection.

As herein shown although not necessarily, the tickenmechanism P comprises a housing l for a reel (not shown), utilizable as a support for a roll of the tape T; the housing I being carried by an arm 2 which is secured to a wall of the ticker base 3 of said ticker mechanism, the housing last named supporting an upper housing 4, both housings being carried by a suitable base 5. As shown, a heavy Weight 6 is suspended on a cable 1 which leads to the operating mechanism of the printing device P and provides power for operating the same. The weight 6 is adapted to bel elevated, when necessary, by any suitable means.

As is well understood in the art, a printing device or ticker mechanism of the character herein described is remotely controlled so as to print desired characters on the tape T which is automatically ejected from said printing device.

After the tape T leaves the ticker mechanism P, it is drawn through a projection device A whereby images of the tape characters are projected` onto any suitable screen. This projection device A may be of any suitable character and, by way cf example, is shown herein as comprising a housing 9 having supported therein a mirror l0 which receives a horizontal beam of light from any suitable light source. The mirror l0 is inclined at an angle of 45 degrees to a horizontal plane so that the aforesaid light beam is directed upwardly thereby for passage through a condensing lens, and then through the projection field which, as herein illustrated although not necessarily, is defined by an elongated, rectangular aperture I2a formed in the top plate l2 of the aforesaid housing 9.

The aforesaid tape T may be pulled or drawn through the projection field |2a by an arrangement of any suitable character. Thus, for example and as herein shown, said tape T may be passed beneath a roller I3 or other guiding surface, this roller I3 being disposed below the horizontal planeof the projection field. Thereafter, the tape T passes over a pulling roller Il, the tape being held in engagement with the upper surface of said pulling roller I4 by an idler roller I5 mounted on a lever I6 whichls biased against other end, is connected to a worm wheel 2| meshl ing with a worm gear 22 rotatable with the armature shaft of a suitable electric motor M.

As shown herein, a suitable support 23 carries the above described rollers I3, I4 and I8, the

' reel I9 and the various associated parts. This support 23 may be of any suitable character and it may be mounted in any desired manner. Thus, if desired, said'support 23 may be secured either directly or indirectly to the aforesaid housing 9.

The reel I9 may be operated in any suitable manner such, forexample, as is well known in the art'. Thus, the 'motor M may furnish the power for driving the reel I9, the latter, preferably, being rotatable by a spring belt-24 of the conventional endless type, such belt engaging pulleys carried respectively, by the shaft of the reel I9 and the shaft I4a of the pulling roller I4. As shown, the projection devicelA isspaced from the printing device P in such manner that a section of the tape T extends between these two devices and, as hereinafter described, forms a tape loop having more or less length or extent. Adapted to engage and to be controlled in position by this tape loop is a movable member 25 which comprises a lateral section 25a, Fig. 2, adapted directly to engage the tape T, said section 25a being cut away as indicated at 25h so as to straddle the single row of characters on the tape T and avoid smudging of the ink forming said tape characters. In the event that there are two rows of characters extending longitudinally of the tape T, the aforesaid lateral section 25a. may be provided with an offset section which engages the tape between said rows of characters. Suitably supported, for example, by the rear wall of the aforesaid housing 9 is a laterally extending member 26 which forms a support on which the member 25 is mounted for free oscillatory movement. 'I'he member 26 also supports two other members 21, 28 both of which are freely oscillatory in the same manner as the member 25. The member 21, on opposite sides thereof, has secured thereto the respective contact members 21a, 21h which are associated with each other in electricity-conducting relation. The member 428, on the lower surface thereof, has secured thereto a contact member 28a which is coactable with the contact member 21a.. The above described contact member 21b is coactable with a contact member 29a. secured to a member 29 which is suitably mounted in fixed position such, for example, as by means which secures it .to the aforesaid housing 9. The member 25 comprises a section 25o, Fig. 3, of di-electric material which is disposed directly below the fixed contact member 29a. so, in the event that the mem- .ber 25 should move upwardly into engagement with the fixed contact member 29a, no electrical circuit would be established from said fixed contact member 29a. through the member 25 which,

, preferably, is formed of aluminum.

'I'he members 21, 28 carry the respective downwardly extending stems 39, 3l, which; preferably are adjustably mounted as shown.

. energized. With the form of the invention illus- For a more detailed disclosure of the printer, projector and tape-pulling mechanism described generally above, reference may be had to mypending application Serial No. 189,042, filed February 7, 1938.

As stated above, the tape T is drawn through trated in Fig. 1, the motor M is an alternating current motor of the series woundtype.

For so controlling the motor M, I may provide a device V, such as an auto-transformer from which a plurality of different voltages may be obtained, saidauto-transformer V comprising the line terminals 35, 36 and a desired number of intermediate terminals 31a, 31h, 31o, 31d 31s, 31t by which, in the manner hereinafter described, a desired voltage may be applied to the In accordance with the invention, a conductor y 38 is arranged to lead from one terminal of a suitable vsource of alternating current, so that it may be connected to the aforesaid terminal 35 ofthe auto-transformer V. The other terminal of said source of alternating current has connected thereto a conductor 39 which leads to and is connected to the terminal 3111.. Connected to the terminal 35 of the auto-transformer V is a conductor 49 which leads to a terminal 40a. forming a fixed contact of a relay R. Coactable with the fixed contact 40a. is a movable armature 4Ia having connected thereto a conductor 4| leading to one terminal of one field winding ,f of the motor M, this field winding f being connected in series with the motor amature winding to which the other field winding fl is connected, the latter, by conductor 42, being connected to a resistance unit 43 having coactable therewith an adjustable contact to which is connected a conductor 44 leading to the aforesaid contact members 21a, 21b of the control switch. Connected to the conductor 42 is a conductor 45 which leads to and is connected to the aforesaid contact member 28a of said control switch. 'I'he control switch xed contact member 29a has connected thereto a conductor 46 which leads to and is connected to the terminal 31d of the auto-transformer V. j

The aforesaid conductor 44 has connected thereto a conductor 41 which leads to one terminal of the winding 48 of the relay R., the other terminal of which has connected thereto a conductor 49 leading to the terminal 31a.

' Connected to the conductor 45 is a conductor V5I! which leads to one terminal of a rectifier unit and 56, the conductor 55 leading to the movable armature 55a of the relay R, the conductor 56 leading to the xed contact 56a 'of said relay R.

In operation, the printing device P, the projection device A and the tape-pulling mechanism are suitably disposed as indicated in Fig. 1' so as to form a straight-line path for the tape T which issues from said printing device in flatwise relation and, while maintained in the same relation, is drawn through the projection field of said projection device A and then wound upon the reel I9. In connection with the described movement of the tape through said projection iield, it will benoted that a suitable device such, for example, as a J-spring or, as shown, a pivoted weight 51 may, if desired, be disposed at the entrance to said projection field, said Weight 51 engaging the sides oi' the tape so as to prevent tape pulsations set up by the printing device from reaching the projection field.

When the control switch is positioned as shown in Fig. 3, i. e., with the contacts 21a, 28a open and with the contacts 21h, 29a closed; the ticker mechanism P may be assumed as operating to eject tape from left to right, Fig. 1, for passage through the projection i-leld I2a.

Assuming that the auto-transformer V is energized by current passing thereto over the circuit comprising the conductors 38 and 39, closure of the control switch contacts 21h, 29a. causes the Winding 48 of the relay R to be energized over a circuit vwhich extends from the intermediate auto-transformer terminal 31a, conductor 49, the relay winding 4S, conductor 41, conductor 44, contact 21h, contact 29a, conductor 46, and thence to the intermediate terminal 31d of the autotransformer. When the relay R is energized in th'e manner described, the armatures 41a, 55aJ thereof are held in the position shown in Fig. 1, the armature 41a at this time being in engagement with the fixed Contact 40a.

With the relay R thus energized and with the auto-transformer V energized as described above, the motor M is energized over a circuit which 'extends from the auto-transformer terminal 35,

by way of conductor 40, terminal 40a of the relay R, armature 4Ia of the relay R, conductor 4|, the field windings fi of the motor M in series, conductor 42, resistance unit 43, conductor 44, contact 21h, Contact 29a, conductor 46 and thence to the intermediate auto-transformer terminal 31d. It will be noted that the resistance unit 43 is included in the circuit described immediately above and, by reason of the effect thereof, the motor M operates at relatively slow speed to draw the tape T through the projection eld 12a.

In the event that the ticker mechanism P ejects the tape at a faster rate than it is drawn by the motor M, when energized over the circuit last described, the tape loop at the entrance to the projection field increases in length to permit counter-clockwise movement, Fig. 3, of the member 25 whereby the contacts 21a and 28a of the control switch come into engagement. In this connection it will be understood that members 25, 21 and 28 are independently movable-within limitswith respect to each other. They are preferably all mounted by the support 26. Also, unit 29 is xed against movement so that it and its contact 28a are movable wtih respect to these members. i

When this happens and with the autotransformer V energized as described above. the motor M is energized over another circuit which extends from the auto-transformer terminal 35, by way of conductor 40, terminal 40a of the relay R, armature 4Ia of the relay R, conductor 4|, the field windings f, fl of the motor M in series, conductor 42, conductor 45, control switch contacts 28a, 21a, 2lb and 29aconductor 46 and thence to the intermediate auto-transformer terminal 31d. It will be noted that the resistance unit 43 is not included in the circuit last described and, therefore, the motor M operates at relatively high speed to draw the tape T through the projection tleld I2a.

During continued operation of the ticker mechanism P, the motor M operates to draw the tape through the projection field |2a, said motor thus operating because energized over one or the other of the circuits described above. In the event that the ticker mechanism P is of the type which operates to eject the tape 'at constant speed, it is desirable for the motor M, when operating at relatively slow speed, to draw the tape at a speed less than the rate at which the tape is ejected by said ticker Amechanism and, when operating at said relatively high speed, to draw the tape at a rateA faster than the rate at which the tape is ejected by said ticker mechanism. Obviously, said relatively slow speed of operation of the motor M may be controlled with precision by adjustment of the movable contact which coacts with the resistance unit 43.

When operation of the ticker mechanism P is discontinued, the motor M, for a short interval, continues to draw the tape with consequent decrease in length of the tape loop at the entrance to the projection field. As the tape loop thus decreases in length, the member 25 is swung, by the shortening tape loop, in a clockwise direction, Fig. 3, to thereby first separate the contacts 21a and 28a, if these contacts are closed, and then to separate the contacts 21h, 29a. When all of said contacts are separated as thus described, the operating circuits for the motor M are opened and operation thereof is discontinued.

With the invention `herein shown, it becomes practical to position the printing device P and the projection device A in such close relation with respect to each other, Fig. 1, that the length of the tape loop between these two devices is relatively short at all times. Thus, in actual practice, it has been demonstrated that the tape loop between the printing zone of the printing device P and the entrance to the projection field has a length, when the tape-drawing motor M is not operating, of approximately 3A; inch. This may, of course, range upwardly to 1 inch, or somewhat more, the tape loop having a length 11/2 inches to 1% inches, more or less, when said motor M is operating. This is distinctly advantageous. With such an arrangement, the information ebtained by observation of the projection screen is almost current at times because only a very little information printed by the ticker mechanism can be stored in the tape loop. It shall be understood that my invention is not to be limited to the exact tape loop lengths specified above.

Therefore, by reason of the fact that the arrangement of Fig. l operates with a tape loop which is relatively short at all times, particularly at the time when operation of the motor M is discontinued, it becomes necessary to provide an arrangement for preventing Coasting of the motor armature after the motor has been deenergized. This is true because if the rotation of the motor armature is not discontinued substantially instantaneously as the motor is deenergized, the tape will be drawn for a short yinterval by reason of the armature inertia and,

with a, tape loop having the short length speci-- fled above, such added movement ofthe tape, after the motor is deenergized, may well cause the tape to be torn or drawn through the print.

ing mechanism. This of course, would be highly undesirable. Therefore, in accordance with the invention, rotation of the motor amature is discontinued in an instantaneous manner immediately upon deenergization of saidniotor.

As hereinbefore pointed out, the circuit of the relay winding 48 includes the controlswitch contacts 2lb, 29a and, v when these contacts are opened as described above, the relay winding 4B is deenergized. When this winding is thus deenergized, the armatures 4Ia and 55a thereof move into engagement with the respective iixed contacts 5Ia and 56a. .As one result of this operation, the armature winding of the motor M is short-circuited over acircuit which extends from the armature 55a, conductor 55., the armaturewinding, conductor 56 and thence back to said armature 55a by Way of the xed contact the auto-transformer V. Further, when the voltage of the supply source differs from the value stated above, it will be understood that the conductor 39 should be connected to the proper intermediate terminal of said auto-transformer V.

In the form of the invention disclosed in Fig. 1,

Vthe winding 48 of thel relay R is energized byfcurrent obtained from the auto-transformer V, such prising the conductors 52 and 53. Thus, direct l current is delivered by said rectifier unit U over a circuit comprising the conductor 50, conductor 45, conductor 42, eld winding fl, conductor 56, fixed contact 56a, relay armature 55a, conductor 55, field winding f, conductor 4I, relay armature 4ta, xedcontact 5ta and thence'back to the rectifier unit by` way'of the conductor 5|.

Therefore, in the manner described, ow of the energizing alternating current through the motor armature is discontinued and, simultaneously, a flow of direct current is established through the motor field windings f and fl, such direct current being shunted around the motor armature. The electro-magnetic effect thus produced on the motor armature, which at this time is rotating by reason of its inertia, acts as a brake to immediately overcome such inertia and discontinue the armature rotation. Accordingly, the motor armature of my invention is controlled in such manner that damage to the tape is prevented' even though there is a very short loop at the entrance to the projection iield. lThe described electro-magnetic effectJ on the motor armature maintains said armature warm during periods of non-operation thereof, i. e., while the tape remains stationary in the projection i'leld. As a result,.the motor M comes up to it normal operating speed more quickly, especially at starting, than would be the case if said armature were permitted to cool.

An important feature of my invention resides in the fact that operation of the disclosed system is not precluded even though the voltage of the. supply line differs substantially from the voltage requirements of the tape-drawing motor available for use. Thus, as shown in the drawings, the motor M may be a standard 11o-volt motor whereas the voltage of the supply line may be 210 volts. Even so, by my invention, the 110- volt motor may readily be connected in the circuit for operation at the proper voltage. In the event that the tape-drawing motor to be utilized requires an operating voltage diiering from that of the motor M, it Will be understood that the proper voltage may be applied across the terminals of the selected motor by connecting the conductor 46 to the proper intermediate terminal of,

current having a Voltage of 90 volts. It shall .be understood that the voltage thus applied across the relay winding 48 may differ in a desired manner from the example of the invention herein shown for purposes of explanation.

Further, as illustrated, the rectifying unit U obtains its operating c urrent by inductive action on the winding of the auto-transformer V. By the unit U, a rectiiied current is applied across the eld windings of motor M and it will be understood that the voltage thus applied across said eld windings may vary between rather wide limits. Thus, for a motor M having an armature of a given weight, it has been ascertained that the voltage thus applied across the eld windings may range between 12 volts and 50 volts. For

motor armatures of diierent weights, it will be system. In lieu of the foregoing, however, I prefer to proceed as hereinafter described by adapt-` ing the arrangement of Fig. 1 for use with a source of direct current.

Thus, referring to Fig. 5, the hereinbefore described input conductors 38 and 39 are shown similarly to the arrangement illustrated in Fig.

4, as having associated therewith a socket 60 and a plug 6 I. y

Adapted to be associated with the socket 60.and plug 6I is aconnector means D comprising a plug 62 and a socket 63, the plug and socket last named being connected by the conductors 64.

Further .in accordance with the invention, there is adapted to be associated with the socket 60 and plug 6l a connector means DI comprising a plug 65 and a socket 66, the plug and socket last named Ibeing connected by the conductors 6l.,`

Included in the circuit comprising the conductors 6l is a variable resistance unit 68 and a rotary converter 69, or equivalent.

Still further) and asy shown in Fig. 6, there is adapted to be associated with the socket 60 and plug 6l a connector means D2 comprising a plug 'land a socket 1|, theplug and socket last named being connected by the conductors' 12..

Included in the circuit of 'the conductors 12 is the aforesaid rotary converter 69, or equivalent.

In the event that alternating current is avail' able for use, the aforesaid connector means D is connected in the circuit of the conductors 38 and 39, this being accomplished by associating the plug 62 and socket 60 on the one hand and the 1 p1ug sl and socket 63 on the other hand. If the the propery intermediate terminal of said auto transformer V.

The rotary 'converter 69 iskof suchlcharacter K that the alternating current output thereof has a voltage magnitude corresponding either with the voltage requirements of the motor M or which may be brought into correspondence therewith by movement of the terminal of conductor 39 to the proper intermediate contact of the auto-transformer V.

In the event that direct current and not a1- ternating current is available for use and if the voltage thereof differs substantially from the rated voltage for the direct current side of the rotary converter 69, the connector means DI is inserted in the line by associating the'socket 60 and plug 65 on the one hand and the socket 66 and plug 6I on the other hand. By proper adjustment of the resistance unit 68, the voltage of the direct current delivered to the input side 'of the rotary converter 69 is changed so as to conform with the rated voltage requirements of the latter. It follows, therefore, that the direct current of the supply lline is changed, by the rotary converter B9, to alternating current which is supplied to the input side of the autotransformer V and thence to the motor M.

In the event that direct current is available for use and if the voltage thereof conforms substantially with the rated voltage yfor the direct current side 0f the rotary converter 69, the connector means D2 is inserted in the lineby associating the socket 6i) and plugy 10 on the one hand and the socket 1l and plug 6I on the other hand.

It will be understood that the connector means DI and D2 are the same identical connector means. are provided so that the resistance unit 68 may be inserted or detached from the input circuit of the rotary converter 69 at will.

It will be understood, in all cases, thaty the terminal of the conductor 39 may be shifted as dem sired to the proper intermediate terminal of the auto-transformer V to produce the desired operating voltage for the motor M..l

In View of the foregoing, it follows that the apparatus comprising the auto-transformer V, the rectifier U and the 'relay R of Fig. 1 may form a permanent assembly for operating the alternating current motor M. With the described connecting means at hand, the system is flexible in the sense that it may be operated either by alternating current or direct current and, further, such system does not require the supply source of current to be of some specific voltage. All of this is highly advantageous particularly when it becomes necessary tov ship the tape-drawing arrangements of my invention into various localities having different kinds of electrical current supply.

It shall be distinctively understood that my invention, as regards magnetic action on the motor armature to discontinue rotation thereof immediately upon the deenergization of the motor operating circuit, is not to be limited to' voltage.

While the invention has been described with Suitable detachable contact members vrespect to certain particular preferred examples whichgive satisfactory results, it will be understood by `those skilled in the art after under- .standing the invention, that various changes and modifications'may be made without departing from the spirit and scope of theinventon and it is intended therefore in the appended claims to cover all such changes and modifications.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a system for drawing a character-bearing tape through a projection field after ejection thereof from a printing mechanism, means fol drawing said tape through the projection field, an electrical motor for operating said drawfor drawing said tape through the projection iield, an electrical motor for operating said drawing means, means forming an energizing circuit for said motor, means controlled by a tape loop positioned between said printing mechanism and said projection field for opening said energizing circuit, and means affecting the motor armature electromagnetically as said circuit is'opened to thereby discontinue rotation thereof substantially in an instantaneous 3. In a system for drawing a character-bearing tape through a projection eld after ejection thereof from a printing mechanism, means fordrawing 'said tape through the projection field, an electrical motor for operating said drawing means, means forming an energizing circuit for said motor, means for changing the speed of operation of said motor to thereby cause the tape to be drawn through said projection iield at different rates of speed, means controlled by a tape loop positioned between said printing mechanism and said projection eld for opening said energizing circuit, and means affecting the motor armature electro-magnetically as said circuit is opened to thereby discontinue rotation thereof substantially in an instantaneous manner.

4. In a system for drawing a character-bearing tape through a projection field after ejection thereof from a. printing mechanism, means for drawing said tape through the projection eld, an electrical motor for operating said drawing means, means forming an energizing circuit for said motor, switch contacts included in said circuit, means controlled by a loop in the tape for operating said switch contacts, means controlled by said energizing circuit, and means operated by said controlled means for affecting the motor armature electro-magnetically when the motor circuit is opened to thereby discontinue rotation of the motor armature substantially in an instantaneous manner.

5. In a. system for drawing a character-bearing tape through a' projection field after ejection thereof from a printing mechanism, means for drawing said tape through the projection field, an electrical motor for operating said drawing means, means forming an energizing circuit for said motor, switch contacts included in said circuit, means controlled by a loop in the tape for operating said switch contacts, means comprising a relay winding controlled by said energizing circuit, and means operated by said relay winding for affecting the motor armature electromagnetically when the motor circuit is opened to thereby discontinue rotation of the motor armature substantially in an instantaneous manner.

6. In a system for drawing a character-bearing tape through a' projection field after` ejection' thereof from a printing mechanism, means for drawing said tape throughthe projection field, an electrical motor for operating \said drawing means, a relay winding, transformer means, means whereby electrical current of different voltages may be` transmitted to the input side of said transformer means, means whereby elec- Y l'trical current of diierent voltages may be transmitted from said transformenmeans to said motor, means whereby `said relay may be energized by current transmitted from said transformer means,.means for discontinuing the ow of current to said m'otor, means for affecting the motor armature electro-magnetically .to thereby discontinue rotation thereof substantially in an instantaneous manner and said relay being connected to said last named means to render the same operative as said relay isV de-energizedf 7. In a system for drawing a character-bearing tape through a projection field after ejection thereof from a printing mechanism, means for drawing said tape through the projection field, an electrical Vmotor for operating said' drawing means, a relay winding, rectifying means, transformer means, means whereby electrical current of different voltages` may be transmitted to the input side of said transformer means, means whereby electrical current of'different voltages may be transmitted from said transformer means to said motor, means whereby said relay may be energized by current of different voltages transmitted from said transformer means, means vfor operating said rectifying means by current transmitted thereto from said transformer means, means for discontinuing the ow f current to said motor, means for aifecting the motor armature electro-magnetically to thereby discontinue rotation thereof substantially in an instantaneous manner said relay being connected to render said last named means operative and to also render said rectifying means operativeA as said relay is de-energized.

8. In a system for drawing a character-bearing( tape through a projection iield after ejection thereof from a printing mechanism, an'electrical motor of the alternating current type, means forming an energizing circuit for said motor, means operated by the motor for drawing the tape throughthe-projection eld, means for drawing said tape 4through the projection iield,l

an electrical' motor of the alternating current ty'pe for operating said drawing means, means formingA an energizing circuit for said motor, means for opening and 'closing said energizing circuit, and direct current supplying, means for maintaining the motor warm during periods of non-operation thereon 10. In a system for drawing a character-bearing tape through a projection eld after ejection thereof from a printing mechanism, means for drawing said tape through the projection field, an electrical motor of the alternating current type for operating said drawing means, means forming -an energizing circuit for said motor,

means for opening said energizing circuit, and

meansfor supplying direct current, affecting the motor armature electro-magnetically as saidcircuit is opened to thereby discontinue rotation thereof substantially in an instantaneous manner, said last named means serving Yto maintain the motor warm during periods of non-operation thereof DAVID F. NEWMAN.

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