US1180293A - Selective signaling system and apparatus therefor. - Google Patents

Description

J. A. HULTT.

SELECTIVE SIGNALING SYSTEM AND APPARATUS THEREFOR.

APPLICATION FILED OCT. 21. 1911.

Patented Apr. 25,1916.

4 SHEETS$HEET l.

d I I. Q /TO//XEEY SELECTIVE SIGNALING J. A. H ULIT. SYSTEM AND APPARATUS THEREFOR.

APPLICATION FILED OCT. 21. 9H.

Patented Apr. 25,1916. I

4 SHEETS-SHEET 2- MZMALML- Y J. A. HUNT- SELECTIVE SIGNALING SYSTEM AND APPARATUS THEREFOR.

APPLICATION FILED OCT. 21. 1911.

a w W7 A m.% 1 ma@ m m m A M a fl m a w WW w W W W. ,1, m F .F fl 4 A [MT/ E5555 Q J. A. HULIT. SELECTIVE SIGNALING SYSTEM AND APPARQTUS THEREFOR APPLICATION FILED OCT. 21,191!- 1,180,293. Patented Apr. 25,1916.

4 SHEETS-SHEET 4.

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Ill

MENTOR:

w MMC JOHN A. H'ULIT, or on caeo, rumors, ASSIGNOR 'ro AUTOMATIC nnnornrc COMPAMY,

OF CHICAGO, ILLINOIS, A CORPOMTION OF ILLINOIS.

SELECTIVE SIGNALING- SYSTEM AND APPARATUS THEREFOR.

Specification of Letters Patent.

Patented Apr- 25, 1916.

nnlicati'on filed October 21, 1911. Serial No. 655,946.

. tion, it is designed principally for use in connection with telephone train despatching systems.

Among the objects of my invention are to provide an improved construction for the station selector, signal transmitter and answer-back apparatus for use in such a signaling system. The station selector is an improvement over my prior patents N'o.

795,836, granted -August 1, 1905, and No. 896,832, granted August 25, 1908. It contains various improvements over these pat? ents, which improvements tend to simplify and improve the operation of the apparatus.-v When apparatus of'this type-is employed in train des etching telephone systems, it. is often desirable to employ" the same line for telegraphic purposes. therefore becomesnecessary to devise aisslective apparatus which is not responsive to these telegraphic impulses, but is responsive to-a code series of impulses. r An 'object of my invention is to provid'e such a station selector which is not operated by telegraphic impulses, nor by a succession of regular impulses, but is operated by an irregular succession of rapid impulses.

A'further object of my invention is to improve the construction of the call-sending mechanism for transmitting the impulses for controlling the station selector. A further object is to provide an improved answer-back device whereby the operator is advisedof the fact that the proper station is being signaled.

These-and other objects of my invention. will be more clearly understood by reference to the accompanying drawings, in which- Figures 1 and 2 are a plan view and ole-- 'vation, respectively, of the station selector.

Fig. 3 is a detail view of the code or combination wheel of the selector. Fig. 4 is a? plan view of the combination call-sending device with the cover plate removed. Fig. 5 is a side elevation of the same. an end elevation of the same. Fig. is a view of'a section taken on the line 77 in Fig. 5. 1 Fig. 8 is a view ofa portionof the side plate which is removed from Fi-g. 5. Fig. 9 is an elevation of the substation answer-back device. Fig. 10 is aplan view of the same. Fig. 11 is a top view of the same with the top plate removed. Fig.'12 represents diagrammatically a'telephon'e line in whlch are connectedtwo substations A. and A, each substation beiii'gequipped with a telephone, a station selector, a call-sending device and an answer-back device. Al-

though only two substations. are shown, any

number of similarly equipped substations may be connected in the linein a similar manner to the two substations shown. I

. Referring first to the substation selector shown in Figs. 1, 2 and'3, theupright frame plates 2 and 3, which may be rigidly se cured to any desired base, form a frame between which the greater partof the mocha nism is mounted. .Journaledin' the plates I 2 and 3 there is a shaft 4 carrying rig-idly secured thereto a ratchet wheel 5 and a coma bin ation'or code wheel, 61 Thesmall spiral spring 7 normally tends torotate the shaft I i in a counter-clockwise direction, as shown in Fig. 2. The shaft 4 is held in normalposition against the tension-of the spring 7 by the engagement of the lug 8 onthewheel 5 with the stationary screw 9. Loosely mounted on the shaft 4 there is a sleeve 10 wheel '11. The flat spiral spring 12 normally' tends to turn the sleeve 10 and ratchet wheelll in a counter-clockwise di motion, as shown in Fig. -2. The wheel 11' is retained in normal position again'st'the of the lug 13 with the stop screw 1%. se-

neath the frame 23 there is an electromag-- .net 15 provided with a movable armature to which there is secured, a second ratchet tension of the spring 12 by the engagement j them in their advanced positions. \Vhen the magnet 15 is deenergized, the propelling pawl is pulled forward by the helical spring 20 to rotate the ratchet wheels. The spring 21 serves to hold the pawl down into the teeth of the ratchet wheels. The pin 22 serves to prevent the pawl 18 from rising out of the teeth of the ratchet when it is pulled forward, and the pin serves as a stop to prevent the propelling pawl from falling more than enough to engage the next notch of the ratchet wheels when the magnet 15 is energized. Thus each time the magnet is energized and dee'nergized. the wheels 5 and 11 are rotated one tooth.

A throw-off is provided for the holding pawl 19 and comprises a balance wheel 24 mounted upon a shaft which is pivoted in the ends of the screws 25 and 26. This bal ance wheel is weighted so that when freed it turns slowly in a clockwise direction. When the wheel has completed a certain portion of a revolution from the position shown in Fig. .2, the pin 27 strikes the tailpiece of the holding pawl 19, forcing said .pawl out of engagement with the teeth of the ratchet wheels and allowing them to be retracted. The balance wheel 2+l is held in the position shown in Fig. 2 by the spring acting through the medium of the arm .29, the rotatable shaft 30 and the arm 31, which arm 31 engages the pin 32 in the wheel. The pin 33 in the plate 3 serves as a normal stop for the balance wheel. Attached to the upper end of the armature 16 there is a hook 3 l which, when the magnet 16 is energized, engages the arm 29 so as to rotate the shaft 30 slightly to raise the arm 31 from the pin 32 to free the balance wheel 24:. Attached to the inside of the plate 2 there is a block of insulation upon which there is mounted a contact spring 36,

the end of which spring is adapted to be en- 7 gage'd by a pin 37 in the wheel 6 after said wheel has been rotated through a certain predetermined distance. 'Around the periphery of the wheel 6 there are a number of notches the spaces between which correspond to the spaces between a certain number of teeth of the ratchet wheel 5. These notches in thewheel 6 are adapted to be engaged by a pin 38 in a balance lever 39 (Fig. 3), whereby said wheel and the shaft 4 maybe held in certain advanced positions independently of the holding pawl 19. The lever 39 is nearly balanced, so that the pin 38 moves into the notches slowly, so that as the wheel 6 is returning to normal position the notches pass the pin 38 so rapidly as not to permit it to drop into them and arrest the motion.

. .The holding pawl 19 has only a slight preponderance of weight on the side which tends to turn it in a clockwise direction to hold it in the teeth of the wheels 5 and 11.

to the same shaft as the holding pawl 19,

by its engagement with the shaft 4:, limits the backward movement of the holding pawl to prevent it from being thrown back too far. i

The method of operation of the selector is as follows: In order to signal any station. the wheel 6 at that station must be rotated to bring the pin 37 into contact with the spring 36 so as to close the signal circuit. It will be seen that the teeth on the ratchet wheel 11 do not extend entirely around the periphery. certain distance (eight steps from normal in the particular instance shown), the smooth surface of the wheel 11 will engage the hold ing pawl 19 and force it out of engagement with the ratchet wheel 5, so that when the propelling pawl is withdrawn, said wheel 5 and the wheel 6 will be restored to normal position. The number of steps through which the wheels may be rotated before they are released in the above manner by the wheel 11 is notsuificient to carry the pin 37 into engagement with the spring 36. It will thus be seen that the station cannot be sig naled by simply sending in enough impulses to step the wheels around the desired distance. In order to complete the'signal circuit the wheel (5 must be rotated a portion of the desired amount and then be held in this position while the pawl 19 is withdrawn to. permit the wheel 11 to be released and returned to normal position. It is the purpose of the notches in the wheel 6 and the lever 39 to hold the wheel 6 in its advanced position when the pawl 19 is withdrawn to permit the wheel 11 to be. retracted.

In detail the manner of completing the operation is as follows: The magnet 15 is first energized towithdraw the pawl 18 and is held energized long enough to permit the throw-off 24 to rotate far enough to throw off the pawl 19, whereupon the wheels 11, 5 and 6 return to normal position, they being held one step advanced therefrom when the magnet 15 is deenergi'zed. Themagnet is then denergized and energized momenta rily a. suflicient number of times to advance the wheels 5 and 11 step by step until a notch in the wheel 6 comes opposite the pin 38 on the lever 39. The energizations of the magnet between these steps must be only momentary, so as not to permit the throwold to throw ofl the holding pawl 19, and the Thus, if said wheel is rotated a deenergizations must be long enough to per- 'mit the holding pawl to drop in each time before the magnet is energized. After the last step which permits the pin 38 to drop into a notch, the magnet 15 is energized for a longer period, whereupon the throw-oil withdrawsthe holding pawl 19. This per-- mits the ratchet wheel 11 to be retracted, but

' the wheels 5' and 6 remain in their advanced positions by reason'of the engagement of the pin 38 with a notch in the wheel 6. After the wheel 11 has had time to be released, the above operations are, repeated to rotate the wheels until the pin 38 drops into the next notch in the wheel 6, when the wheel 11 is again released. These operations are repeated until the pin 37 finally engages the spring 36. Assuming that the notches of the wheel 6 are spaced as shown in F ig '3, and that the pin 38 in the normal posltion of the Wheel engages the lowest or first notch,

i it will be seen that two steps are required to bring the wheel to the next stop position, four 'more steps will bring it'to the next stop ,position, five to the next, and then five more steps will bring the pin 37 against the spring 36. Thus the numberof the instrument containing the wheel shown in Fig. 6 may be said to be 2455. It is to be under stood-that the combination wheels 6 of all the different selectors 'on a line are arranged for a different combination of, impulses-.-

.that is, the notches are spaeeddifi'erently.

Thus, although the operating magnets of all the selectors may be operated in unison by any combination of impulses, only the selec-- tor having a combination wheel corresponding toy that particular combination of impulses will be operated to close its-signal circuit. The combination wheels of all other selectors will be automatically released ,one or more times during the operation. Although the notches of the combination wheels of all the selectors are-spaced d1fferently, the total number of steps reqnired to close the signal circuit is preferably the same in all the selectors. There is ne notch in the wheel 6 to be engaged by the pin 38 when said wheel is in its most advanced position, so that said wheel isrelease'd the first time the magnet 15 is energized after the call has been made. i

Referring now to Figs. 4*, 5," 6," 7 and 8.

the construction 'of the cal-Lsendmg apparatus is as follows: The entire mechanism is contained in a metal case. Journaled between the end wall 40 and the partition 41 there is-ashaft 42 to Whicharefirmly secured a plurality of toothed wheels 43. Above these wheels there is a swinging frame comprising the pivoted shaft .44, the side arms 45 and 46 securely fastened to said shaft, andthe-cross 47. Loosely mounted upon a shaft 48 thereisa-pawl 49 the end of which isfadaptedto be engegedfby the rod.55' which slides upon a shaft 56.

42 to. rotate'the impulse wheels 43.

before the wheels have completed teeth of one of thewheels 43 during their rotation. The cross bar 47 of the swinging frame described above rests u on the top of the end of the pawl 49, and the end of the:

spring 50- of the pair of contact springs 50 and 51 rests upon the top of the arm 46. When the pawl 49 is raised by the teeth of the wheel 43 it swings the frame upward, thereby separating the springs 50 and 51. Slidably mounted upon a shaft 52 there is 'a member 53 provided with a fork which fits over the rear end of the pawl 49. To the member 53 there is attached a handle or lever 54 .which extends out through aslot' in the wall ofthe case.- By means of this handlethe pawl 49 maybe moved laterally to engage any oneof the wheels'48 desired-. An indicator on the outside of the case (Fig. 8) shows'which wheel the pawl 1s 1n POSItiOIl'tO engage. To prevent the pawl? 48 from falling down between the wheels, isprovided with a projecting pen the end of the shaft 42 which --pro]'ects through the partition 41 thereis attached a. geanwheel 57 which meshes with a gear-- wheel 58 which is loosely. mounted upon a shaft 59. Securely attached .to the shaft 59 there is a lever 60 and a ratchet wheel 61, which latter is adapted to be engaged by a pawl 65 on the side of the gear wheel 58.

On the opp0site side of the gear wh'eel. there of the one with which it was previously resting in engagement. When the lever 60 is released it is returned to its upper-position by the-spring 62, and the ratchet wheel 61 engaging the pawl 65 forces the gear wheel 58 to rotate with it. The rotation of the gear Wheel 58 is transmitted to the shaft ()ne complete stroke of the lever 60 is su'fiicient to rotate the shaft 42 and wheels 43 through a complete revolution. In order to positively stop the shaft 42 after it has completed its revolution, there is secured to said shaft a stop lever 66 which is adapted to engage the stop 67 on the shaft 59 when the lever '60 is at the top of its" stroke.

lVhen the lever'60 is pulled down, the stop 67 passes out of the path of the lever 66, thereby releasing the impulsewhe'els; but

tion, the stop 67 is returned to its normal position to be engaged by the lever 66. The speed of rotation of the impulse wheels is governed by the escapement 68 operating through the medium of the gearwheel 69. In

a revolu orderto provide means for properly lini 11g up the impulse wheels, a hole 15 placed through 'each wheel in exact relation with regard to the normal or. starting point, and a pin 74 is then run through all the wheels. This insures that the normal or starting point of all the wheels will hein a straight line when magnet of the selector is controlled through the back contact of a relay. The relay is controlled by the springs 50 and 51 of the call-sending apparatus. Therefore, the operating magnet deenergizes to step the ratchet wheels around each time the pawl 49 of the call-sending device drops into a notch to permit the springs 50 and 51 to close. The codes will then he represented on the wheels of the call sending device by a number of series of short teeth representing momentary energizations of the operating magnet of the selector, followed by a longer tooth representing a longer energization of the magnets. The long teeth on cachwheel will correspond to the notches in the combination wheel of the particular selector represented by that impulse wheel in the call-sending device. Before beginning the code proper, there are two long teeth on each of the impulse wheels which are for the purpose of insuring. that all the selectors will he returnedto normal position before the impulses of the code are being sent in. These two impulses will cause two successive long energizations of the operating magnets of the selectors, which will insure that, all of the combination wheels will he returned to normal position whether they resting with the pin 38 in a notch or not. The spaces between the teeth of the impulse wheels are comparatively long. This is to insure that the magnets of the selectors shall remain dei nergized long enough each time to allowtlie'holding pawl 19 to drop into the teeth of the ratchet wheels before the magnet is again energized. Thus. while the impulses sent out by the calI-scmling device are of theproper character to progress the ratchet wheels. the short dots and dashes representing Morse characters, as produced by an ordinary telegraph key. will he too short to permit the holding pawls of the selectors to drop into the ratchet teeth while the oy'icrating magnets are dei nen gized, and said Morse characters will, therefore, not progress the ratchet wheels. Thus. since the ordinary dots and dashes repre senting ll'ltilsl" characters are incapahle of progressing the ratchet wheels of the station selectors, a line equipped with said selectors may he used as an ordinary telegraph line without falsely operating the selectors.

The answer-back device shown in Figs. 9, l0 and 11 comprises a frame consisting of two plates 76 and 7 7 secured to the posts 78, 7 9 and 80. Journaled in the plates 76 and 7 7 there is a shaft 81 to the upper end of which there is secured a pointer or indicator 75. Between the plates 76 and 77 there is firmly secured to the shaft 81 a ratchet wheel 82, and just beneath this ratchet, and loosely mounted ,on the shaft, there is a gear wheel 83. Beneath the gear wheel there is a coiled spring 8%, the inner end of which spring is attached to the shaft 81, while the outer end of the spring is secured to the post 79. Upon the top of the gear wheel 83 there is a pawl 103 which engages the ratchet wheel 82. The gear wheel 83 meshes with a pinion 85 on a shaft upon the upper end of which there is a toothed wheel 8., the teeth of which wheel are arranged to correspond to the dots and dashes representing v a Morse character. The teeth on the Wheel 87 at each station are to be arranged to give a different character. The teeth or raised portions of the wheel 87 are adapted to contact with the insulated spring 88 during the rotation of said wheel. The gear wheel 89 is also secured to the shaft 86 and meshes with a gear 90 which is secured to the escapement wheel 91 through the medium of which the speed of operation of the device is controlled. The apparatus is normally locked in the position shown in Figs. 10 and 11 by the engagement of a pin 92 in the wheel 89 with a pin 93 in the side of the lever 9+; In the end of the leve1-9-l there is a pin 95 which extends downward into a slot in a lever 96, the end of which lever 96 strikes upon the end of the armature 97 of the electromagnet 98 and thereby preventsthe pin 93 from being movedout of the path of the pin 92. \Vhen the magnet 98 is energized, the armature 97 disengages the lever 96, which permits the pin 93 to free the pin 92. The shafts 81 and 86 then hegin to rotate. When the shaft 81 has made a portion of a revolution to bring the stop 98 down into the path of the pin 99, as shown in dotted lines in Fig. 10, the wheel 87 has made a complete revolution, and theengagement of the pin 99 with the stop 98 brings the mechanism to rest. In this position of the shaft 81 the pin 100 makes-contact with the insulated spring 101. Just before the shaft 86 completes its revolution. the pin 92 in the wheel 89 strikes therod 102 and turns the lever ill so that the pin 93 again comes into the path of the pin 92 to lock the mechanism. when the indicator 7:") is manually returned to its original position.

The returning of the indicator to its original position restores the tension to the spring 84 and turns the ratchet wheel 82 so that the pawl 103 engages the next notch,

ally exerting a force against the armature 97 and will therefore slip off and release the mechanism the instant the magnet 98 is energized. It will. thus be seen that only a very short impulse through the magnet is required to release the mechanism and cause it to make a complete cycle.

- In Fig. 12 each of the substations A and 'A are shown provided with a station selector, a call-sending device and an answerback device of the character described in the preceding paragraphs. In this figure, 110wever, the apparatus is represented only diagrammatically, the various parts of both substations being represented by the same reference numerals as inv Figs. 1 to 11, in-

'clusiye. The line connecting the substations comprises a single line conductor, the ground -'being used as a return. Beyond the substa- 1 tion A." the line is grounded through an -impedance coil 104, and before reaohing'the' "substation A the line passes from ground through a battery B and impedance coil 105.

1 back device, wheel 87 and frame of the device, and thence through a relay 106.to the next substation. One terminal of the magnet 98 of'theanswer-back device is connected through a battery B with the frame of the station selector, and'therefore with the pin 37. The. other terminalof the magnet 98 is connected with the spring 36. The frame of the answer-back device or the pin 100 is connected through a hell or other suitable signal 107 with one terminal of a battery B the other terminal-of which battery is connected with the spring 101. The operating magnet 15 of the selector is included in the connection between the back contact of the armature of the relay 106 and the battery 13 Each station is shown provided with an auxiliary telegraph key 108'and short-circuiting switch 1095 At each substation a telephone T is bridged between the line and ground.

" Thetelephone may be provided with any suitable hook switch or key for opening and closing its circuits as desired- An ordinary telegraph sounder '110 is also provided, which sounder is connected with the front contact of the relay 106.

The complete operation by which one station signals another is as follows: The operatorat thecalling substation sets the indicatol' of his call-sending device to the number of the ,desiredsubstation and then pul'r. rloyentthe lever=60. As the lever returlff l'tfl) ilormal positiom the particular ima; pole wheel 43 of the call sender pver which the pawl 19 has been placed first separates the springs 50 and 51 twice for a comparatively long time, each time breaking the cir cuits of all the relays 106 on the line. Each time these relays denergize they close the circuits of the magnets 15 at their respective substations. These two preliminary impulses, as has been explained are for the purpose of insuring that thecombination wheels 6 at all the substations shall be returned to normal. The calling device impulse wheel then proceeds to send out the particular combination of long and short impulses, corresponding to the station desired. As previously explained, the combination wheel 6 at this station will be rotated to bring the pin 37 into contact with the spring 36, whereby the circuit of the magnet 98 of the answer-back device is closed. The magnet 98, upon energizing, releases the mechanism, as previously explained, and allows the wheel 87 to make a complete revolution and the pin 100 to come into contact with the spring 101. The engagement of the pin 100 with the spring 101 closes the circuit of the bell 107 to signal the attendant; The wheel 87, during its revolution, first opens the line, then closes it a number of times, in accordance with the Morse character of the station called, and returns the line to normal closed condition. The first opening of. the lineallows the re lays 106 to fall back and close the circuits of the magnets 15. At the called substation this energization of the magnet 15 releases the combination wheel of the selector. The closing of the line in accordance with the Morse character of the called substation causes this character to be sounded on the sounders 110 at all the stations. The operator at the calling station, upon hearing this character, knows that the proper substation has been called and that the bell at'said station is ringing. The attendant at the 'it will beevident that iffthesystem is one in which the various substations on the line are not supposed to call each other, but in which the substations are only to-be called by a master station, only the master station need have a call-sending device. Also, instead ,of -a. single line conductor and a ground return, two line conductors may be used if desired and the controlling relays 106 may bebridged across the line instead of being connected in series, as shown herein. Likewise, while I have shown but a pair of substations, it is evident that any number 1. In a signaling system, a station selector,.

means for operating said selector by an interrupted series of regular impulses of greater duration than telegraphic impulses when said impulses and interruptions are in a predetermined order, and for preventing said selector from being operated by a successlon of telegraphic impulses, and means for preventing said selector from being operated by an uninterrupted series of said regular impulses.

2. In a signaling system, a line circuit, means for transmitting telegraphic impulses over said line circuit, station selectors connected with said line, means for transmitting an interrupted series of impulses of greater duration than said telegraphic impulses over said circuit, means controlled by said impulses for selectively operating said selectors when said impulses and interruptions are in a predetermined order, and for preventing said selectors from being op crated by said telegraphic impulses. and means for preventing said selectors from being operated by an uninterrupted series. oi regular impulses of greater duation than telegraphic impulses.

3. in a signaling system. a line circuit. means for transmitting telegraphic impulses over said circuit. station selectors connected with said line. means for transmitting a plurality ol' series of regular impulses of greater duration than telegraphic impulses over said circuit, each ol' said series being separated by one or more prolonged impulses for selectively operating said station selectors. means For preventing said station selectors from being operated by said telegraphic impulses. and means for preventing said selectors from being operated by an uninterrupted series of regular impulses.

-l. in a signaling system. a station selector including an clectromagnet. a ratchet wheel. a propelling pawl For said ratchet wheel controlled by said electronuignct. a holding pawl. a ratchet wheel segment loosely mounted upon the same shaft with said ratchet wheel. means controlled by said segment for releasing said holding pawl from the ratchet wheel to permit the. same to re turn to normal position after a certain numher of propelling strokes of said propelling pawl. a third wheel rigidly mounted on the shaft with said ratchet wheel and provided with a series of notches on its periphery. aml a holding pawl therefor for holding said ratchet wheel in advanced position when said pawlis in engagement with one of said notch s.

5. In a signaling system, a station selector including a ratchet wheel, a propelling pawl for operating said wheel in a step-by-step manner in one direction, a spring for returning said wheel to normal position, a holding erated by a series of rapid operations of said propelling pawl, said holdingpawl is thrown out of engagement with said ratchet teeth to thereby prevent said ratchet from being operatively rotated.

6. In a signaling system, a station selector including a shaft, a spring-returned ratchet wheel rigidly mounted thereon, a second spring-returned wheel loosely mounted on said shaft, :1 propelling pawl engaging said wheels, means for'holding said wheels in advanced position, and means controlled by said second wheel when it has been advanced a predetermined distance for rendering said holding means inoperative.

' 7. In a signaling system, a station selector including a shaft, a spring-returned ratchet wheel rigidly mounted. thereon, a second spring-returned wheel loosely mounted on said shaft, a propelling paw] engaging said wheels. a holding pawl for holding said wheels in advanced position. independent means for holding said ratchet wheel in certain selected advanced positions, aml a throw-oft for disengaging said holding pawl from said wheels to permit said second wheel to return to normal.

S. In a signaling system, a station selector including a shaft. :1 spring-returned ratchet wheel rigidly mounted thereon, a second springreturned wheel loosely mounted on said shaft. a propelling pawl engaging said wheels. a holding pawl for holding said wheels in advanced position, a third wheel rigidly mounted on said shaft and provided with a series of selectively arranged notches. a holding pawl for engaging said notches for holding said third \vheeland ratchet wheel in certain advanced positions. and a throw-oil for disengaging said first-nientioncd holding pawl from said first two wheels to permit said second wheel to return to normal.

5). In a signaling system. a station selector including a shaft. a spring-returned thereon,

ratchet wheel rigidly mounted a second spring-rcturucd wheel loosely mounted on said shaft. a propelling pawl engaging said wheels. a holding pawl for holding said wheels in advanced position,

independent means for holding said ratchet wheel in certain selected advanced positions,

and a throw-oil for disengaging said holding pawl from said wheels to permit said second wheel to return to normal, said throw-off being slow acting, whereby it is only brought usages into operation during a pause between the series of operations of said propelling pawlv y 10. In a signaling system, a station selector including a shaft, a spring-returned ratchet wheel rigidly mounted thereon, a second s'pringreturned wheel loosely mounted on said shaft,--a propelling pawl engaging said wheels, an electromagnet'for controlling said propelling pawl, means for transmitting a varying number of impulses through said magnet to selectively operate 'saidratchct wheel, means for holding said wheels in advanced position, and means controlled by said second wheel when it has been advanced a predetermined distance for rendering said holding means inoperative.

1].. In a signaling system, a station se lector including a shaft, a spring-returned ratchet wheel rigidly mounted thereon,

a second spring-returned wheel, looselymounted on said shaft, a propelling pawl engaging said wheels, an electromagnet for controlling said propelling pawl, means for transmitting a Varying number of impulses through said magnet to selectively operate said ratchet wheel, a holding pawl for holding said wheels in advanced position, independent means for' holding said ratchet wheel in certain selected advanced positions, and a'tl'irow-ofi for disengaging said holding pawl from said wheels to permit said second wheel to return to'normal.

12. Ina signaling system, astation lector'including a shaft, a springmeturned ratchetwheel rigidly mounted thereon,

a second spring-returned wheel loosely mounted on said shaft, a propellingpawl engaging said wheels, an electromagnet for controlling saidpropelling pawl, means for transmitting a varying number of impulses through said .magnet to selectively operate said ratchet wheel, a holding pawl for holding said'wheels in advanced position, a third wheel rigidly mounted on said shaft and provided with a series of selectively an first two wheelsto 66 means for holding sai ranged notches, a holding pawl for engag ing said notches for holding "said third wheel and ratchet wheel in certain advanced positions, and a throw-oil" for disengaging said first-mentioned holding pawl from said permit said second wheel to return to normal.

:13. In a signaling system, a station selector including a shaft, a spring-returned ratchet wheel rigidly mounted thereon, a second spring-returned wheel loosely mounted on said shaft, :1 propelling pawl engaging said wheels, an electromagnet for controlling said propelling pawl, means for transmitting a varying number of impulses through said magnet to selectively operate said' ratchet wheel, a holding pawl for holding said wheels in advanced position, inde endent ratchet whee in certain selected advanced positions, and a throw-oft for disengaging said holding pawl I from said wheels to permit said second wheel to return to normal, said throw-oi? being ratchet wheel rigidly mounted thereon, a

second spring-returned wheelloosely mounted on said shaft, a propelling pawl engaging said wheels, an. v,electromagnet for controlling said propelling paw'l, means for transmitting a varying number of impulses through said magnet to selectively operate said ratchetwheel, a holding pawl for holding said wheels in advanced position, a third wheel rigidly mounted on said shaft and provided with a series of selectively arranged notches, a holding pawl for engaging said notches for holding said third wheel and ratchet wheel in certain advanced positions, and athrow-oif for disengaging said first-mentioned holding pawl from said first two wheels to permit said second wheel to return to normal.

15. In a signaling system, .a station selector including a spring-returned ratchet wheel, propelling and holding means therefor, a slow acting throw-oil for the holding means, means-including .a ratchet wheel segment for controlling the forward movement of the ratchet wheel, and selective means associated with the-ratchet wheel for holdr lector including a spring-returned ratchet wheel with propelling and holding means therefor,

means-including a ratchet wheel segment for disengaging said holding means to permit the ratchet wheel to return to normal after a succession of propelling strokes,

and means independent of said segment for holding the, ratchet wheel, whereby the ratchet wheel segment maybe returned to normal without returning the ratchet wheel 17. In' a'signaling system, a station selector including a spr1ng-returned ratchet wheel, propelling and holding means there for, means including a ratchet wheel segment for disengaging said holding means to "permit the ratchet wheel to return to'normal. and means forrestoring both the ratchet wheel and segment simultaneously.

18. In a signaling system, a station se-' lector including a spring-returned ratchet wheel, propelling, holding and releasing means therefor. and means whereby only a succession of uninterrupted ratchet-progressing strokes will means ineffective.

-19. In a signaling system, a station se- 'lector including a spring-returned ratchet wheel, propellingand holding means thererender the holding til 1,180,293

for, mechanical. releasing means for the hold-' ing means. whereby a; long pause between propelling strokes will restore the ratchet Wheel. and an independent means for positively holding the ratchet Wheel progressed.

'20. In a signaling systen'n a station selector including a spring-returned ratchet heel. propelling, holding and releasing means therefor, and means whereby a suc- 11') cession of uninterrupted ratchet progress ing strokes will render the holding means inefieetive said ratchet Wheel moving in a continuous direction in response to said succession of strokes.

Signed by me at Chicago, Cook county, lllinois. this 18th day of October. 1911.

JOHN A. I-IULIT. \Vitnesses:

ARTHUR J. RAY, llmmun l). FALus.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Eatentm,

Washington. D. G.

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