US2006305A

US2006305A - Carrier dispatch system

Info

Publication number: US2006305A
Application number: US585556A
Authority: US
Inventors: Harold F Wilder; Hakon H Haglund
Original assignee: Western Union Telegraph Co
Current assignee: Western Union Telegraph Co
Priority date: 1932-01-08
Filing date: 1932-01-08
Publication date: 1935-06-25
Anticipated expiration: 1952-06-25

Description

June 25, 1935. H. F. WILDER ET AL CARRI/ER DISPATCH SYSTEM -3 Sheets-Sheet 1 Filed Jan. 8, 1952 INVENTOR H F WILDER I H. H. HAGLUND aqmm 'm BY ATTG'RNEY um DP KUQQEP June 25, 1935.

H. F. WILDER El AL 6,305

CARRIER DISPATCH SYSTEM 3 Sheets-Sheet 2 Filed Jan. 8, 1932 w R mwU E TD N NL R EIA v T mFH M HH Y va June 25, 1935.

FIG. 6

H. F. WILDER ETAL v CARRIER DISPATCH SYSTEM Filed Jan. 8, 1932 3 Sheets-Sheet 3 INVENTOR H. F. M LDER H. H. HAGLUND BY ATTORNEY Patented .lune 25, 1935 CARRIER DISPATCH SYSTEM I Harold F. Wilder, Chatham, N. J.,,m1 Hakon n.

' 'Haglund, New York,

N. 11;, assignors to The v Western} Union Telegraph Company, New flYork, N J 'Y a corporation of New yor -Application:January s, 1932, semi Nofssasss An object of this inventio'n is to provide means 7 operated by th'e'carriers as they travel along the guideway to'cause a carrier to be discharged from the 'guideWay-at a predetermined point or branch .therealong. Another object is 'to provide an arrangement which-will operate automatically and efiectivelywhenthe carriers are traveling at high speeds along"the'guide'ways" According to this invention the dispatch system may embody guide- 15 ways comprising'pneumatic tubes and cylindrical carriers for-'traveling'in; the tubes. It should be borne in mind, however, that the principles of this invention are applicable to any type of carrier system. Means 'areprovidedfalong the tubes associated-with openings in'the tubes or branches joined to the tubes, forcau'sing carriers to be selectively diverted from the guideway into the-discharge opening-or to-the branch tube. Means are provided on the carriers for selectively operating :the deflector or discharge means corresponding'to the point or b'ranch'at which the carrier. isdesignated to' 'be discharged. By utilizing the above arrangement a carrier system maybe developed which'employs'a main or feeding guid'ewayof any desired extent, having a" plurality of branch guidew'ays leading therefrom jwith the" branches having also other branches leading from them, if desired. The main guideway or' a' pneumatic tube may extend office, to 'a'distant branch office with the branch guideways leading to branch ofiices lying in' betweenfthe main "and distant oifice. In this manner, by the selection of the proper carrier, at mes- Atsuch speedsit is extremely difficult to devise mechanisms which are mechanically engaged by the carriers wfor operating "the discharge or with the various branches." l I l I =-*:It:hasf-beenfproposed to utilize 'electricdischarge tubes as relays in the place of mechanical relays; operated-by actual contact with the car riers. The electrical relays maybe operated by from a main 'oflice,'such as a'central telegraph 'sage may' be sent to any of'th'e b'ranch orlices at switching mechanism employed in connection means impressing a' potential thereon set 'up when the carrier passesacertain*p'oint'along the guideway. Even in this case, the duration of such potential is ordinarily onlya fe'w' microseconds, which is insu'fiicient to cause the ordinary 5 type of electronic'discharge deviceto operate connected mechanical 'devices'.'-'It is proposed;"ac-- cording to. this invention, ito "employ" a special type-10f electronic dischargetube having what is known as a trigger operating characteristic; which 10 will respond to potential of short duration, such as are obtained'with high 'speed'operations." 5 By trigger operating characteristic ismeant"a de vice Whichwhen set into operation will conftinue in operation independent of the initiating force." V L p Y .Another objectof this invention is,'therefore to provide a carrier diSpatch systemwith' relay devices for controlling the switching or deflecting mechanism provided at the branches whicli havehat is knownas triggeroperating-characteristics and whichvvillrespondto potentials-of extremely short duration. T

' i Another object of this invention is 'to 'pr'ovide a system of the-character described, having a switch or deflecting device at the entra ce of the branches of the guide discharge tubesghaving trigger operating characteristics for moving the deflector into operating position as the carrier passes one point along the guideway and outof 0 deflecting positionwhen the carrier. passes-am other point alongthe guideway; 7 A still further object of thi's-inventioni's topro vide a system of the character*just'described in which'themechanisms set into operation bythe carriers are-located entirely externally of the car rier'tub'eior guidewa l It hasbeen found in: connection with thdtype of: con t1'ol' mechani'sm' described above, that the electronic discharge tubes operate most erreenve: ly when subjected to'a single impulse'as the carrier passesthe control point.- To-thisend a's'el'ec' tively responsive mechanism which will sup'ply only a single impulsehasbeen devised, fsucn a mechanism comprises a magnet arranged'withits poles spaced longitudinallyo'f' the guideway and inductancesin the fieldof the magnet for picking up'icurrent induced by the magnets as'they'are effected by operating means carried on'fthe car- 'riersin the form of armatures Ofmagneticmate rial; which bridge the poles of the magnet asjthe carrier passes *the' 'same." Selective operatic is provided by' employing magnets with thei'rfpioles spaced 'at different distances and with armatur es on the carriers of a predetermined length correspondin'gjto the spacing of the poles of the magnet which the carrier is designated to influence. Withthis arrangement, if the magnets with the wider spacings arearranged nearest the starting point or entrance of the main guideway and arranged progressivelycloser together with the direction oftravel, those carriers designated for points beyond the first branch willnot completely bridgeany off the magnets until itfhas reached the magnet" with pole spacing corresponding to the length of the armature on the carrier.

A still further object of this invehtionQtheretore, is to provide for selectively applying an operating potential to the electronic relay devices by employing magnets havingjtheir poles. spaced longitudinally of the guidewaysand spaced at difjferent distances at the respectivebranches.

These and'other objects willbe apparent from the following description and'cla'ims taken in combination with the accompanying drawings forming a part of this application in which? .g'F'i'grlis a diagrammatic view r a pancra system Showing 1 one branch leading from the r guidew'ay; 25

Fig. 2 is'a detailed view of the arrangement of the relay energizing magnet shown in' Fig: 1;

'.,;Eig. 3 is a detailed view of a carrierprovided with Sin e magnetic band thereon; 1 liig 4 ,isa diagrammatic. view showing anar- "Ian ement' employing a carrier with two spaced bands ,on the carrier. and magnets correspondingly'spaced on the guideway arranged to operate the discharge tubes arrangedwith their output circuits in series; l

Fig. 5 is a view showing the discharge tubes proyidedwith two types Q quenching circuitsand V means to switch from one circuit; to the other;

r ,6 is a diagrammatic illustration showing twofb fanches leading from the guidewayand provided with selectivecontrolling magnets arranged withtheir' poles disposed longitudinally of the i d y ndfipaced at difierent distances;

, {7 shows the magnets provided with'poles 45 terminating in the form of a loop or ringsur rqund n'z the carrier; 1 Fig.3 is a view illustrating the method'of magnet ae ly couplin the spaced bands on the carrier'sand, g I I V v Figs. 9 and l are views illustrating an arrangement employing a single magnet for selective con- Beierring to lfigs. 1 to 3 of'the drawings apart '7 or a' system employing the simplest embodiment fw l si nre t o iisshown. A pneumatic convey-' 9! tube J! i iprovided wit fan inlet terminal; ll

' end a source of air pressure [2. Only one'br'anch station is illustrated. It is v provided 1 by a branch tube l3 leading from the main tube and having enoutlet termina An inlet te in I into themain tube may be provided'at the branch station {or'sending to stations located, beyond the F-Sihhl' ich-1 CWIEI'S' 0 the t pe j such as'carietlfi how n Fi 3 a emp oy d n h y j e branchtube l3v connectedwith the main tube jdthrough a special coupling member Ill i 7' which houses a defiect or or "switching member l8 pivoted at. its lower end and arranged to. assume 7 either oneof two positions. One oi these positions Elmo t esme n lea n nt h th an bee id a he ise rbs t e at o h m iti i i time format si onhe en r to. the

iliemh iiib i fcw o f and t ers passin through the coupling section I! are continued a the ne n tube. while in h la r p iti n wires 24 toga source of potential;

the path of the main tube cut of! and carriers are diverted therefrom into the branch tube. The

operating solenoid l9, provided with a movable core and connected to the switch operating arm 2 I, controls the movements of the switch.

In order to provide for selectively operating the switching mechanism, designating means is placed on the carrier or carriersintended to be. r

' sent to'the branch? station. as resfionsive t0 the "designating means onth c trier 'ls'firovided forcausing the switch to'be moved into position across the path of the main tube when carriers designated for the branch station are sent through the systemjAccording to this invention, the conveyortube J0 or a section thereof in advance of the branch tube switch. ismade of a non-magnetic materialand a magnet 22 is disposed at a certain" point along this section in advance of the switch member It and arranged with its poles at opposite sidesot the conveyortube I 0 substantially as shown in Fig. 2. This magnet'is arranged to operate a relay..mechanism*wlfich controls the ioperating. solenoid 1 9. .rrne magnet may be a permanent magnet or an electromagnet n rgized by: coils '23. connected through the lead type of;magnet,"pick-up coils .25 are provided which areconnected through wires" to therelay. A detecting "magnet'iscausedto respond to-the passage of a carrier by the pointalong With either" the magnetic circuit,v causing a potential-tome loye t o e ate the relay. 1 When carrier speeds'of from 1200- tozflllilfeet P r m n eare em loyed. such as arer induced in thepick-up coils 25 which maybeemto meet the requirements'of modern rapid service. I

it will beseen that a band one. carrier of a'width substantially equivalent to the width of the Doll faces, which it will be'as sllmfid" for example is one inch, will ass between the poles oithe magtypes of mechanical relays. Moreover,: with a variation in a magneticfield of such a short durnetin from twotorom thousandtm or a second; t willbe readily armr t this-1s quite e e vely operatingtn present ation it is quite difllcult to obtain therefrom"an induced current pulsation Q1 llfllcient lengthfto I operate a mechanical relay- "Ordinary vacuum tube relays have been proposedi'or overcoming thev limitations of; the weak impulseslbutliere mechanical relay for controlling the switching device and the combined system issubject to the 5&metirnelimi tations asud recl mechanical relay action.

However, successful operation of a' system in which thejcarrierstravel at high speed is made] possible by employing a special type of electronic discharge device having whatis known as trigger Q operating characteristics such as "the" s'oecalled r or g seousdi har e tubes which are capable of passing the'requisite iamount of current for i operatingythe switching device and may :be controlled by a relatively small amount ofcurrerit.

This tube ischaracterized by the'fact'tliat itnors m ally interposes a higherresistancein'the circuit in which it is connectemwhich" resistance may be broken down-by a relatively small current 1 in the auxiliary .or'control circuit. 'Such'tubes are now well known'in the art and brietiy consist again-the vacuumitube relaysc must operate a of, a gas filled'envelope which contains an sec;

1 suitable potential the tube will break down and,

t The action of tl' cgrid may/therefore. be likened terrupting switch 33 to a source of "positive podue to the are discharge then occurring'will' allow a large amount of 'curreht'tofiow from the anode to the cathode,

'The tube is unlike the ordinary three element vacuum tubefo'r' audion in thattas soon as an anode current starts'the grid has no further in- .fluenc'e' on the anode cur'r'entand the discharge can be stopped only by removingthe anode voltage'or reducing it to; the extinguishing point.

to a trigge'nand the term triggerfaction or'trigger operatingcharacteristic as used herein is employed'to designate any type of electronic discharge device operating'in' the "above manner.

In"the'embodiment of the invention above described an electronic discharge tube 27 is ar ranged to supply the operating c'urrentto the switch operating solenoid. Thetube is provided witha cathode 28 heated'from a suitable source of current, 'a starting grid 29 andfan anode 3!. The pick-up coils 25 are connected through the l'eadwires Z fi'intheciicuitof the control grid 29. The anode is connected through wire 32 in series with fthe operating solenoid i9 and a circuit intential. When a carrier l6 having a band of magnetic material thereon is inserted into the carrier'tube l it will proceed until it passes the position ofthe'"mag'net 22'whereit will cause the fluctuation in the'magnetie field, inducing surge of potential in the pick-up coils 25 and the circuit including the grid 29. The grid-is ordinarily maintained at a'slightly negative potential. The induced'cui'rent impulsewill cause a positive potential tobe impressedupon thegrid 29 and due t'o'its trigger operating characteristicthe tube will break down and space current will now from the cathode'to the anodeij When this'i'oc'curs the solenoid will beenergized and the switch mechanism immediately swung ove'r into the path of the main tube. Thedetecting magnet is positioned sufiiciently aheadof the switch mechanism to permit the switch to move was deflecting position before the arrival of a carrier. When the 4 carrier enters the branch tube l3 it will engage a cam 34raising the same and opening the switch 33'. This will interrupt the anode circuit and cause 'theresistance'of the tube to be restored, or in other words, allow deionizationto occur.

"Besides operating a switching mechani'smthe arrangementjustdescribed may be employed for counting carriers or 'other"objects which pass a certain oint alonga guideway." Other uses may. be -made' of the arrangement for detecting the number of objects of or'containing magnet material which-passe; certain point. 7

When a carrier having only one ring or band oi'magnetic material is employed, the selection is limited to one of two destinations; This would restrict the systemic a main tube with a sending station and ajsta-tion at the remote end thereof and one intermediate branchstation. To transmita message or other'article to the remote station, at the end of the mainjtube a carrier having 110 band would be employed, i'n-orde'r thatthe magnetic circuit in advance of the branchstation would not be affected by thepassageof the carrier designated for the remote station. When it is desired to transmit to the branch station a carrier having'a'm'agn'etic band thereon would be employed. Asthis carrier passes through the magnetic field between the poles of themagnet it will modify the field,.thereby setting in operation the devices which cause it to be diverted'into the branch tubein'the manneralready described.

If it is desired to provide a system permitting the carriers to be sent to more than two destinar" tions, this may be accomplished by employing in addition to the single band carriers, other carriers withtwo or more bands of magnetic ma; terial spaced} a suitable distance apart longitudinally of the carrier. The number of stati'ons whichican be added to the sy'stem' will be determined by the number of carrier bands which may be employedlspace'd at the minimum affective distance apart. At the station for which a carrier provided with a specific number of bands is de's-.

tined, a corresponding number of magnets will be placed along the conveyor to be spaced apart, at

distances corresponding to the bands on thecarrier.

Referring to Fig. 4 an arrangement is illustrated in whicha carrier employingtwobands is utilized. The carrier I6 is; supplied with bands 35 and .33 surrounding the central portion of the carrier and spaced longitudinally thereof A pair oi

magnets

31 and 38 are arranged with their poles on opposite sides of the carrier tube substantially as shown in Fig. 2, and are spaced apart longitudinally of the tube at a distance corresponding to the spacing of the bands on the carrier. The magnets may be of substantially the same form as those illustrated in connection with the foregoing embodiment; These magnets are arranged to energize two electronic discharge. tubes by being coupled in the grid circuit ofthe tubes in substantially the'same manner as where a single magnet and a single tube are employed.

The grid of each tube is coupled to its corresponding magnet so as to be subjected to the potential induced by the modification of the mag-' netic fields as the carrier bands. pass therethrough.

It will be observed'thatas the carrier passes the I magnets the leading band 35 will first pass through the held of the magnet 31 and subse'- quently through the field o f the magnet 38. The

band 36 will pass through the fields in like order.

However, it will be observed that thefields will be simultaneously'modified only when the leading band 35 is passing through the field of the mage net 38, coincidentally with the passage of the. 01 lowing band 36 through the magnet 31. v

With a multiple band carrier arrangement the relay tubes could be connected to an operating solenoid of such a character that only the total chest of all of the-tubes operating simultaneously would cause the solenoid to respond. However, according to this invention, amore effective method is employed. "instead of the outputcircuits "ofthe tubes being connected in multiple with the solenoid they are connected in series. In other words, in this arrangement the grids 4| and 42 of the relay tubes 43 and ddi'espectively' are connected independently or parallel with the magnetic pick-up coils while the anodes'45 and .48 of the respectivetubcs are connected in series.

That is, the path oithe current through the tubes would be from the cathode. 6.0 of the firsttube 43 to the anode 45 thereof, thence tothecathodefl Solenoid 49 in series therewith and to a source of positive potential. In this arrangement it will be observed that the relay tube 44 is at some. intermediate potentialrathe r than at the same potential as the tube 43, and as a result the cathode V .of the tube must likewise be maintalnedrat, some intermediate potential. This may be provided for by the insertion of a battery 5| 7 between the positive potential for the anode of the first source of negative potential and the cathode. This arrangement likewise provides the required Wlth'the relay tubes in'series due tom-naural high resistance of the tubes before they are triggered off, the starting of either one of the tubes alone will not start theother'tube and therefore the output circuit will not becompleted. The completion of the output circuit can be accomplished only when both of' the tubes are started at thesame time by a simultaneousfap plication of the required' starting potential to'the.

grids of the respective tubes. A I

With an arrangement such as 'just described it willfbe seen that three or four. or' any other suitable number of tubes may be arranged in series and excited bythe corresponding number of magnetic fields placed along the 'carrier tubef tobesiinultaneously' excited by magnetic bandson the carriers.

4 d This wouldprovide for an ad ditional station for each group of tubes used, increased in arithmetical series. In addition to providing for selective discharge of the carriers by thnumberof carrierbands and magnetic fields employed, this arrangement maybe made selective by 'a different spacing of the bands along the carrier." If the bands are spaced differently it is obvious that simultaneous potentials will beimpressed on the grids of the tubes only whenthe carrier passes a group of fields spaced at the same distance as the bands on the carrier.

Inthe'embodiment first describedthe switch- 'ing device for divertingthe carriers at the interinediate or branch stations was restored to nor- :inal by means operated by mechanical contact with the carriers. 1 Although the interruption of a circuit can be more readily accomplishedby operations of an extremely short duration than the completing of 'a circuit, any type "of mechanical engagement with the carrier subjects the manner as employed in connection with the circuitinitiating the movement of the switching d means.j Referring to Fig. 5 such-an arrangement is provided by employing a magnet 52 along the branch tube l3 instead of the cam operated switch 33 (shownjinFig. l) The switching he mechanism l8isusually biased toward one of its extreme positions and in the embodiment first described it is biased toward the position over the entrance ofthe branch tube. Therefore, after the switch'haa been moved across the'path of the main tube in response to the operation of the relay it is only necessary to deenergize the relay to permit the switch to return toits normalposi tion. "I'h erefore, when a'magnet is employed for restoring purposes the relay may be deeriergized by employing an arrangement which will'cause the discharge tube to be quenched in response to the passage ot the carrier, through the field of the restoring. magnet.

The arrangement shown in Fig. 5 providin g dr .this comprises two, relay tubes 53 and 54 arranged to be started by the magnet 22 ahead of the switching. device and the. magnet'52 in the branch tube respectively. The, two relay tubes are arranged to operate in a connected circuit by means of whichthe tubes are mutuallyquenching. In other words,,one of the tubesbeing in operation, it is extinguished or quenched by ac tion set up by the other as soon as it hasstarted.

Such an arrangementis describedfin the proceedings of the National Academy of Sciences, March,

l921,"vol. 15, No. 3, page 218. The tube 53 i s ar ranged so that when a current is induced into. the grid circuit as a carrler passes between thenpoles of the magnet along. theguidewaiy I0 astarting impulse will be impressed upon the grld55'of relay tube; The required positive potential for the anode56fof this tube is supplied through the wire 5l which includes, in series therewith the switch operating solenoid l9 andoneside ofthe bi-polar changeover switch 58.'1The gridcircult 2 I of theo'ther relay tube 54 include'sthe piclgfup coils 62' of the magnetj52, whichprovides for similarly impressing a starting potentialon the grid 59 whenthecarrier passes said magnet in its travel through thei branchltube, l3. Positive 3 potential is suppliedto the anode 63 of the latter relay tube through the wire 64 and the other side of the changeover switch 581 q A resistance 65 may be included in this circuitto supplya balancing load in the output circuit of the latter V relay tube. The anode circuits' of .the tubes are bridgedby a condenserit When a carrier, passes the detecting magnet 22 the switch will be moved into the diverting position and at the same time the condenser 66 will will-be charged from tube5 3, 'As the carrier passes the divertingv switch, into the branch tube and reaches the restoring magnet 52, the other relay tube 54 willbe'started whereupon the condenser 66 which was previouslycharge d from the tube 53 will now be subjected to current in a reverse direction, and therefore discharges in such adirection as to momentarily reduce the voltageln the anode circuit of the tube 153 suflicientlyto interrupt the discharge extinguishing this tube.

While the changeoverswitch 58, is connected in its upward position the tube flwillcontinue v v in operation until it is in like mannerextinguished by the startingof tube '53, which or curswhen the nextgcarrier arrives havingv magnetic material thereon. When this tube starts it. will subject the condenser 66 to another pul'sation of current in a, direction the reverse of. the

current last impressed. 'I'his will likewise act to momentarily reduce the volta e ,in the anode circuit of the tube 54sufliciently to'interruptvthe discharge through this tube. V, r r

From the above itwill .beseen-that when one tube is started it remains in operation untilthe Y maining out of operation until it is again start-I6 other tube is started when it is quenchedreed by the passage of a carrier This arrange ment is very satisfactory where the carriers pass at fairly frequent intervals.

periods of operation,;it would not be'economical to operate the mechanism in the abovemanner because one of the tubes would bedrawingjcur rent during extended periods of inactivity. Dur: 1 S eier a s it s Phi 1W5 that 54..

However, if the: interval of arrival of carriers is substantially ex-. tended, whichmay readily occur during certain relay having a trigger operating characteristic, a; starting circuit'and a sustaining circuitforsaid relay,fm'ea'ns in th'e starting circuit for impresse ing a' startingpotential on the relay when a carrier passes a certain point along the guideway, and means for interrupting the sustaining circuit when the carrierj passes another point along the guideway. l

9. In a carrier system, a guideway, carriers for the guideway, each of said carriers having elemerits of magnetic material thereon arranged to embrace'a diilerent longitudinal portion thereof for different carriers, a single magnet disposed adjacent to the guideway and arranged to selectively respond to only those carriers having elements thereonembracing a predetermined longi tudinal portion of the carrier, and a relay as; sociated with said magnet andarranged to be energized thereby when the magnet responds to a carrier. T- v -10. In a carriersystem, a guideway; a carrier, a single magnet located adjacent said guide'way,

' the poles of'said magnet having aloop formation at their ends encircling'said guideway, said poles being spacedapart predetermined amount longitiidinally of said guid'eway, and inductance coils in the field'of said magnet, an armature of magneticma'terialon the carrier extending longitudilength of the magnetic material on the carrier,

said'magnet being adapted to have its poles moniehtarily bridged by said magneticmaterial as the carrier passes the, magnet, inductances-in the field of said magnet, a local circuit includingsaid induct ances, and a relay adapted to be energized byQthe potential set up in the inductances when .the magnet is bridged. L V I ,v 12. In a carrier system, a guideway, a carrier, magnetic material of a predetermined length securedto the carrier, a magnet adjacent to the guidewayhaving its poles spaced longitudinally of the guideway at a distance corresponding to the iength of the-magnetic material on the carrier, said .magnet being adapted to have its poles momentarilybridged by said magnetic material as the carrier passes the magnet, inductances in the field of said magnet, a local circuit including said inductances, an electronic relay having a trigger operated characteristic adapted to be started. by the potential set up in the inductances when the magnet is bridged, and means for stopping the relay after a period of time has elapsed.

13. In a carrier system, a guideway, a carrier, a pair of bands of magnetic material spaced at predetermined distances on the carrier, said bands being coupled by magnetic material extending between them and partially around the carrier a magnet adjacent the guideway having its poles spaced longitudinally of the guideway at a distance corresponding to the bands on the carrier, said magnet being adapted to have its poles momentarily bridged by said connected bands as the carrier passes the. magnet, induc tances in the field of said magnet, and, a relay adaptedto be energized by the potential setup in the inductances when the magnet is bridged.- Q- t 14. In a carrier system, a main guideway hay;-v

ing a plurality of discharge points therealong,

carriers for the system including 'carriers desighated for each of the dischargepoints, a single magnet in advance of each of the points having its poles disposed adjacent the guideway and spaced apart longitudinally thereof, the poles of said magnets being spaced differently at each discharge point, each of said carriers being provided with a longitudinally extending armature of a length suitable formomentarily bridging the poles of the magnet corresponding to the point at t which it is designated to be discharged, a switch} ing device at the respective discharge points, a

local'circuit coupled to each magnet, a local operating relay for each switching device arranged to circuit when the poles of the magnet to which it is coupled are bridged.

15. In a carrier system, a main guideway having a plurality of branch guideways leading there-f from, carriers for the system including carriers designated for each of the branches, a magnet in advance of each of the branches having its poles spaced longitudinally of the guideway, the poles of said magnets being spaced at a progressively.

less distance apart in the direction 'of travel of the carriers, said carriers being provided'with armatures suitable for momentarily bridging'the poles of the magnet corresponding to the branch for which they are designated, whereby carriers designated for branches beyond the first branch will not bridge the magnets reached before the magnet corresponding to the branch for which the carrier is designated, a switching device'at the entrance of the respective branches, a local circuit coupled to each of the branch magnets, a local operating relay for each of the respective be energized by the potential induced in the local switching devices arranged to be energized-by'the potential induced in the local circuit whenthe poles of the magnet to which it is coupled are bridged.- c

16. In a carrier system, carriers, a'guideway for the carriers comprising a pneumatic tube having a branch leading therefrom, a switching device.

normally in inoperative position but movable into operative position to deflect carriers into the branch tube, meansoperative as a carrier passes one point along the guideway to move the switching device into operative position and means operative as the carrier passes another point to restore theswitching device to normal position, said latter means being disposed-entirely externally of the tube.

17. In a carrier system, carriers, a guidewayfor the carriers comprising a pneumatic tubehaving a branch leading therefrom, a switching device normally in inoperative positionbut mov able into operative position to deflect carriers into the branch tube, means to move the switching device into operative position, and means operative as the carrier passes a point-along the guideway to restore the switching device to normalposition, said latter means being disposed entirely externally of the tube.

18. In a carrier system, carriers, a guideway for the carriers comprising a pneumatic tube having a branch leading therefrom, a switching device normally in inoperative'position but movable intooperative position to deflect carriers into the branchtube, alocal controlling circuit fori op'erating th switching dev ce, ma 0 g "piete the circuit as a carrier passes one point along the guideway; and means to interrupt the circuit asjthe carrier passes another'point along theguideway sa id latter means being disposed entirely externally of the'tube.

7 320 A pneumatic carrier system, carriers, a

iiideway for the barriers comprising a main Dilbl tube having one or more branch tubes leading therefrom; means associated with "each of thefbranch tubes to divert; carriers from the mayhe a'carri'er passes onepoint along'the uideway, said tube being interrupted by means eiit ally ofthetube when carrier passes ii'notiirpoint. r

.21. In a pneumatic carriensyst'e'm,carriers, a

a J guideway for the carriers having one or more branches leading therefrom, means associated with,each branchfto' divert carriers thereintofrom the main 'guideway, said'rneans being con jtrolled'by 'first' and'second electronic discharge passes one point along the guideway,,and said secondtube being started when the carrier passe-s another point along? the guidewa-y, and means 1 actuated bythesecondtube to extinguishthe first tube as soon as the second starts.

I,'i'22. "A, pneumatic carrier'system according to" claim, [tin-which one electronicdischarge tube opera-testo move the diverting means to switching p'osition and the other electronic discharge tube; operates to return the same to normal; ;2 3.,]I n a pneumatic carrier system, carrieraa guideway for the carriers having one or more branches. leading therefrom, means associated 1 tubes, said first tube being started into opera-v withl each branch to divert' carriers thereinto from the main guideway, said means beingcon-j trolled byfirst and second'electronic discharge tion by means actuatcdwhen the carrier passes one point; along the guidewaypsaid second tube being, started when the carrier passes another point along the guideway, means-actuated by the second tubeto extinguishthe first as soon as the secondtube, starts, and automatic means to subsequentlyv extinguish the second tube,

24. Ina pneumatic carrier system, carriers, '-:1 'guideway for the carriers having one or more branches leading therefrom, means associated with each branch to divert-carriersithereinto from the main guideway, said meansbeing con- 7 trolled byrfirstandsecond electronic discharge tubes, said'flrst discharge tube being'star ted into operation by ,means' actuated. when a carrier .passes one point along the guideway, said second, tube being started when the carrier passes ianothe'r jpoint along the guideway; iand'means actuated byeach tubeas soon as it startsto ex- 7 25. In a pneumatic carrier system, carriers, a guideway 'for the carriers having one .or more branches leading therefrom, means associated with ,each branch to divert carriers'there'into; from the main guideway, said means being con-' trolled by first and second electronic discharge tubes, said tubes, being provided with alternate circuit arrangements, one of said'circuit arrangees, said first discharge'tube being started mm p'eration by means actuated when a carrier attests ments providing for the first tubetobe started into operation by means. actuated when a can rier passes one point alongthe guide'way, and for the second tube to bestartedwhen the carrier passes another point alongthe guideway and meansactuated by each tubeas soon as it starts to extinguish'the other tube, said second circuit;

arrangement providing for the tubes to be started in a manner similar to the first arrangement, and providing means actuated by the second' tube assooh as it starts'to extinguish the first tube, and automatic means to subsequently extinguish the second tube, and switching means provided for switching from one of said circuits to the other as'desiredn I maintub'e thereinto, said means; being controlled by an electronic discharge tube, said discharge tubes being started into operation by means actutermined spaced-relation along the body oi the carrier. said coils being connected together in parallel, a magnetic fleldat a point along the guideway and inductance surrounding the 'guide- I way and spaced longitudinally thereof from the field at aidistancecorresponding to the spacing" of the coupling coils on the carrier, a local circuit including said'inductanoe', a,relay energizedby the'current setup in said inductance asthecou pling coils on the carrier pass simultaneously through said field and said inductance, andimeans to deenergize said relay aftera period oftime has elapsed.

2'7. In a carrier system, aguidewayhaving al plurality of discharge joutlets'itherealong, carriers adapted to travel along the guideway, said carriers having elements ofmagne'tic material thereon embracing different longitudinal portions of the carrier according to the outlet at which it is designated to be discharged, a'single magnet disposed adjacent to theguideway in advance of each discharge outlet and arranged to selectively respond to the carriers designated for that outlet, a switching device at the respective'dischkrge outlets, a local circuit'coupled to each magneha local relay for each switching devicearranged'td be energized by the potential induced in' the local 1 circuit when-the magnet responds" to afcarri'er. 28. Ina carrier system, a guideway, a carrier,

a plurality of bands ofmagnetic materialspaced at' predetermined distances apart on' the""car= rier, magnetic fields arranged at corresponding distances apart'on the guideway 'and adapted to ,be simultaneously modified by the-bandsonithe 7 carrier, a local circuit, an arcdischa'rge""tube relay corresponding to each of the magnetic fields and having a grid arra'ngedto be charged by the magnetic fields for conditioning the relay for discharge, said relays being arranged with their discharge circuits in series so that said local circuit is completed through the discharge path magnetic fieidsarranged at, corresponding" dis tances apart on the guideway and'ad'ap'ted tobe simultaneously modified'by the bands on theicarrier, a local circuit combination, a relayin. said circuit combination corresponding to each 01' said magnetic fields, each of said relays compris ,ing an electronicdischarge tube having-a; trigger 7 operating characteristic, each of said tubes being all of said relay s'becomeienp i l in d by the modification i or said Q T provided with an independent input circuit for supplying a starting potential tothe tube, said input circuit being separately supplied with a starting potential by the modification of the respective magnetic fields, said tubes having their discharge circuits connected in series in said local circuit combination so as to provide a plurality of seriescircuit closing means in said circuit, said local circuit combination being characterized by the fact that the failure of one of the said tubes to discharge prevents all of them from discharging, so that the circuit closing means in said local circuit combination will not be disturbed. except when all of said tubes are simultaneously started.

30. In a conveyor system for conveying articles,

article selective means for controlling the path of travel of articles through the system comprising a slow acting electrically operated device, current controlling means in circuit therewith :for operating the same, and means disposed in position to selectively respond to the passage of certain articles for operating said current controlling means, said latter means embodying an electronic device for supplying current to the slow acting device, said electronic device being maintained at a substantially constant current output level for a sufficient time to complete the operation of said slow acting device.