US986260A - Selective lock-out telephone system. - Google Patents

Description

P. W. ADSIT.

SBLBGTNB Loox-OUT TBLEPHoNB'sYsTBM. APILIOATION FILED N07. l?, 1909. I 986,260. Y v n Patented Mar. 7, 191L 14 SHEETS-SHEET 1.

y @Attorneys F W. ADSIT. SELBC'IIVB LGK-OUT TELEPHONE SYSTEM.

. APPLICATION FILED HOY- `17l 19g9 Patented Mar. 7,

K 14 SHEETS-SHEET 3.

Qggdmg, A I WJ? P. W. ADSIT. f SELEGTIVB Loox-OUT TELEPHONE SYSTEM.

. *Y n u L APPLICATION FILED NGV. 17. 1909. 986,260, Patented Man?, 1911.

' Y l 14 SHEETS-SHEET 4.

1/159 nimm-5; 3,5( @JW y JuLsAzzomey.'

v F..W. ADSI'I.

SELBCTIVE LOCK-OUT TELEPHONE SYSTEM. APPLIOATION FILED 11011.17, 190s.

i 986,260; 1 Patented Mam, 1911.

Y n 14 BHBBTBBHBET 6.

. P. W., ADSIT. Y SELBCTIVE LOCK-OUT TELEPHONE SYSTEM.

APPLIGATION FILED HOY. 17, 1909.

l Patented Mam, 1911.

14 SHEETS-SHEET '1.

"Iig-f P. W. ADSIT. SELBGTIVE LOCK-OUT TELEPHONE SYSTEM. A

APPLICATION FILED NOV. 17, 1909. F

Patented Mar. (,1911.

1.9865260. Y K A I 14 SEBBTS-SHBET'8.

Wb'lzaises: 1.5 159 maxtor, mw/7 JMT@ Y M ,By his Attorneys.'

MWMW" ?Mw www' Y P. W. ADSIT. SELECTIVE LOCK-OUT TELEPHONBSYSTBM.

APPLIOATION FILED NOV. 17, 1909. Y

, Patented Mar. 7, 1911.

.14 SHEETS-SHEET 9.

P. W. ADSIT.

SBLBCTWB LOCLOUT TELEPHONE SYSTEM,

' APPLICATION FILED NOV. 17, 1909. I Y K Patented Mar. 7, 1911.

1.4k SHEETS-SHEET l0.

Wig

,flat/'erden' @Fu/MM Y @www F. W. AD'SIT.

SBLBQ'IIVE LOCK-OUT TELEPHONE SYSTEM.

APPLICATION FILED HOV. 17, 1909.

Patemed Man?, 1911.

14 8BEETS-SHEET l1.

Y-tzzfss; 30 7i MKM Y l yju@ Azwmew:

F. W. ADSIT. SELBGTIVE LOCK-OUT TELEPHONE SYSTEM.

APPLmAToN FILED nov. 17, 1909. v Patented Mar. '7, 1911.

14 BHBET SSHBET 12.

W.- ADSIT. n

SBLBGTIVE LOCK-OUT TELEPHONE SYSTEM.

APPLICATION FILED BOV. 17, 199. u

Patemed Mar. 7, 11911.

14 SHEETS-SHEET 1`3 www? ,5%

frnnNnw. Ansr'r, .or sr. PAULMINNESOTA.

' SELECTIVE LQCK-OUT TELEFHONE SYSTEM.

' To alliwhom it muy concern:

Be it known that I, FRANK 1V. Ansrr, a citizen of the United States, residingat St.' Paul, in the county of Ramsey andState of Minnesota, have invented certain new and useful Improvements in. Selective Lock-Out Telephone-Systems; and I 'do hereby declare the following to be a full, clear,.and exact description of the invention, such as will enable othersskilled in the art to which it api,

pertains to make and use the same.

My invention has for its object to provide an improvedV selective lockout telephone system especially adapted for use on rural 1 I f tion consists of the novel devices and comtelephone lines, and to this end, the inven l hinations of devices hereinafter described and defined 1n the claims. The' invention 1s,

fao

however, capable of a wide range of use in connection with telephone systems andother electrical communicating systems.

'In the accompanying drawings, which illustrate the invention, like characters indcate like parts throughout ythe severalviews.

Referringto the drawings, Figures 1 to 8, inclusive, are diagrammatic views illustrating the .wiring o the improved system; Fig. 9 is a diagrammatic view in elevation, showing the relative arrangement of certain .parts o? the local instrument which, for convenience, are located within a suitable case; Fig. 10 is a vertical section taken on the line :v10 :61 of Fig. -9, some parts being broken away 'and some parts being removed; Fig. 11 is a view chieiiy in elevation but with some parts sectioned and some parts broken away, showing mechanism herein designated as the selector actuator; Fig. 1?'is an elevation of the mechanism shown 'in Fig. 11 looking at the same from the left toward the right, some parts being broken away; Fig. 13 is a plan View showing a group of contact springs of the register actuator, some parts being sectioned; Fig. 14 is a front elevation of the knob and index plate of the selector actuator; Fig. 15 is an elevation looking atthe inner end of the actuator knob; Fig. 16 is a section taken approximately on the line m1 m16 of Fig. 11; Fig. 17 shows the magneto and certain other coperating parts of the local instrument, Fig. 18 is an end elevation of the magneto -looking at the same from the left toward v Specification of Letters Patent.

Application .led November 17, 1909. Serial No. 528,436. f l

the right in respect. to Fig. 17; Fig. 19 is Patented Mar. 7, 1911.

a fragmentary view showing the lower portion of the said magneto looking at the same from the right toward the left; Fig. 2O is a detail in section on the line .fu-2 x2 of Fig. 17; Fig. 21 is a fragmentary view, chiefly in side elevation, but with some parts sectioned. showing the upper portion of the magneto and certain parts of the local instrument, which are located immediately above the magneto; Fig. 22 is a horizontal section taken on the lineari22 m22 of F ig. 21,

some'parts :beino' broken away; Fig. 23 is a view in ront elDevation showing one of the n party selectors, one of which is provided in each local instrument; Fig. 24 is a fragmentary view, in front elevation, of certain of the parts shown in Fig. 23, some parts bel ing broken away and other parts beingremoved; Fig. 25 is a side elevation of those portions o the mechanism illustrated in Fig. 23 which Aare at the right of the line 4:1:25 m25 marked onlFig. v23; Fig. A26 is a horizontal section taken on the line. ai ai of Fig. 23, looking upward; Fig. 27 is a vertical section taken'on the line ai" of Fig. 25; Fig. 28 is a'view in front elevation with parts broken'away, showing the indicator for indicating whether or not the line is in use; Fig. 29 is avcrtical section taken on the line w29 ze of Fig. 28; and Fig. 30 is a detail in elevation showing the indicator disk orthe said indicator.

The principall parts of the local instrument, one of which is at each station, are the transmitter, the receiver, the local battery connection, aso-called party selector, a so-called selector actuator, a magneto', the receiver hook mechanism, the bell, and certain other auxiliary devices such as .magnetic trip mechanism for releasing the Selector actuator. These devices are, preferably, monntcd within or upon a suitable .case or cabinet 1 of any suitable construction.

- Party seZect0r.-The details of this device are best shown in Figs. 23 to 27, inclusive.

cured to the block 3. OutsideA of the contact ring t the insulating t a iunltii'ilicitv of zircnmfa-rcntally spaced;

ycrforations T. in :mione o1 of'a third contact. 5S is adapted to lic inserti-d. The pcrforations 7 mustbe evcnl);v spaced and there ma y be any desired number thereof, hr.: theytr represent each a diterent. .sta-

tion and the adjustable contacts S, at the dxtcrcnt stations, must he .set 1n dillerent c1rcumferential positions. lotatively mounted on the outer end ot the stud 6 is a ratchetv wheel J which, as shown, has three times as many teeth as there are pcrtforat'ions 7 in the fixed disk E2. These ratchet teeth. how

ever, may be arranged in any desired mul- 1 tiple, one or more,.ot` the said perforatious 7, but for clearness of description, it musi he ren'iemhered that, as shown, three ratchct toothed movements ot the said ratchet n-heet secured to and projecting outward from the ratchet wheel t) is a crank-like .rod 10 nhich is l'zormally held against a fixed stop 11, by a coiled spring attached at its outer end g to said ratchet wheel and at. its inner end to the projecting end of the stud C. In the construction illustrated, the rod 10 has secured to its onterend an indicator disk 13 (see Figs. 2S) and 30') havinga marked segment 1i that normally registers with a segmental opening 15 in the front of the ease 1. Normally, also, the contact brush 5B stands in the gap of the segmental contact ring 5 andA only the contact brush t maintains contact' with its coperating contact ring It. For imparting the step blv step movement to the Aselector ratchet wheel t), I employ a polarized magnetindicated as an entirety by the numeral 11', and this is preferably secured to the top of the case l, immediately above said ratchet -wheel. The

'numeral 17 indicates a bracket which, as

shown,is secured to the extended cores ofthe electromagnets,ias shown in Fig. 23. A pair oflaterally-oftset armature levers 18 and lf) are intermediately pivoted to the said bracket 17 and stop screws 18 and 1f):i are arranged to limit., respectively. the downward movement of the righthand end end of said armature lever 19. fr:

(See Figs.

armature lever 1S attached a depending spring ratchet panl '10, the hooked lower :rnd of which engages the tet-th of the ratchet wheel 9, and which. under each upward movement of the righthand end of said lever 1B, imparts one ratchet tooth of movement to said vsheel. Baa-.kaal d movement of said vwhich the :siem

' cjgement. with the driving pant ll i the right. and 2G.) To the righthand end of the is formed with t ratchet wheel is nermall)y prevented by a spring-pressed retaining pawl Q1.. Eccen- :zit-alb7 pivoted to the block 3 in close cnand ratchet pawl'Ql is a pawl1elea.sing eccentric :22 that is connected by a. link to the righthand end of the armature lever 19. Fit-cured to and dependingr from the lei'thand end of said armature lever 19 is an arm 2t provided at its lower end with a. block E25 of insulating material which is adapted to engage the curved portion of a spring Contact the free end of which is normally out of engagement with a companion contact '27. The two contacts .26 and 27 are insulated from cach other but supported by a bearing Q8 which, in turn, is secured to the back of the case 1. ll'hen the lefthand end of the armature 19 is raised, the eccentric 9:3 `afill force both of the pavvls Q0 and 91 out of engagement with the teeth of the ratchet vvhcel S) and. smiultaneously. therewith, the free end of the contact 2G will be Jforced into engagement with the contact Q7. The purpose of these actions will be more fully stated in the description of the operation.

Magneto constrwtonrfI-his mechanism is best shown in Figs. 17 to 20, inclusive. Of

theparts of he magneto proper. which ma)r he ofstandard type, the numeral 29 indicates the permanent magnet connected to side plates 30. and the numeral 31 indicates the rot ating arnntture.I the shaft 3Q of which is jonrnaled in end plates 33 shown as secured to the outside magnet. The armature shaft- 32, at its righthand end as shown in Fig. 17.' is provided n'ith a small spur pinion Bt that carries an eccentric contact Gnce for each rotation of the pinion Si, the contact 35 is engaged with a spring contact 516 supported by the adjacent bearing plate 533. The pinion 31 meshes with a spur gear 257 secured to the outer end of a sleeve -SS 1iournalcd in the righthand bearing' plate 33. To the inner end of the sleeve 3S is secured a ratchet Wheel or hub provided with ratchet, teeth on its inner face Extended through the sleeve 38 and journaled therein and in a bearing on the lefthand plate is a crank shaft 40. Secured on the righthandc end of the crank shaft, 40, as shown, bf threaded engagement, is an operating crank 41 between which and the righthand end of the sleeve 38 is interposed I a short coiled spring 42 that normally holds of .said armature lever 1S and the lefthand the said shaft in its extreme position toward The movement of the shaft. 40 toward the right is limited by a cam pin '23 projecting radially from said shaft and working in a spiral cam groove 44 in the sleeve 38 (see Fig. 17). Loosely mounted on the shaft, 40 and free for limited sliding movement thereon is another sleeve 45 hav.- ing a radial pin 46 (see Figs. 17 and 20) that is adapted to engage the'teeth of the ratchet hub 39; A coiled torsion spring 47 surrounds the sleeve 45 and is secured thereto at one end and to one of the side plates at its other end. This spring 47 yieldingly resists rotation of the sleeve in the direction of the arrow marked on Figi'. Q0 and also exerts an endwise force tending to hold l.. t l

L .said sleeve in its extreme position toward the right in respect to Fio. 17. Otherwise pin 46 against. a fixed stop 48 and in engage ment with the ratchet teeth of the hub 39.

righthandedge it is beveled to form a cam.

" Located immediately above the ratchet hub 39 and pivoted to the plate extension 33@ is a downwardly spring-pressed lockinpr and releasing dog 49. At its free end, this dog has a beveled stop surface 50 with which the i pin 46 is adapted to engage. The bevels of ,the lug;r 48 and of the snrface 50' are in re` verse directions, but the engagement of either thereof under the pin 46 forces or holds said pin out of engagement with the ratchet teeth 39. Supported by a suitable insulatingV block. on the lefthand bearing plate 33, and insnlaterl from each other, is a group ofv spring contacts 5l, 52, 55, 56, 5T, 58 and 59. The lower end othe Vspring contact 51 constantly engages with 1an extended terminal 31ya of the armature coil, which terminal, as shown, projects at and is insulated from one end of the armature shaft 32. The free ends of the spring contacts 51, 54 andA 57 are separated by insulating spacing blocks 60. The upper end of the innermost contact 5] is insulated from, but subject to movement of. the lower end of a hell 'crank G1 and the lefthand end of the operatingr shaft 40. The said bell crank (il is shown as pivoted to an upper end extension 33 of the lefthand bearing crank is piroled to the lower end of a connet-tingr rod 62. It. may be also here noted 'that the free end cf the lock dog 49 is pivoted to the lower end of a connecting rod G3.

Here-incr molr ami assoc-infer! parts-The receiverbook G4 (see Figs. 21 and 22) is pivoted to a bearing plate (35 secured Within the case 1 substantially the usual way, and is .vieldingly pressed upward b v a spring (3ft. the strength if which is not', of course. .sufficient to raise the .said hook when the receiver is applied on the hook. Located vour the nook t-t. but laterally otl'set there` from. is a f froup of spring contacts GT. 68. 69. 70. Tl Vand 72, .whichcontats are insulatt-:dffroin each other and supported by fan insulating block 73 secured to said bearin;r plate GTL -The spring contacts 67 and (38 are longer than the. other spring ontacts ani. they" plate 33 and the other arm of said bell are providedV with curved ends adapted to be engaged and separated by an insulating hul) 74 carried by-the receiver hook (i4.

-Pivoted to the bearing plate 65, at the right of the hook 64, is a bell crank 'i' 5, the lower arm of which is pirotally'connected to the upper end of the rod (33, which latter. as just noted, is connected to the trippingr dog 49 of the magneto int-chastated, the said spring normally holds thc.'

nism. A downwardly springpressed hooki ended dog TG is pivotally connected to the flipper arm of the bell lcrank 75 and its as shown in Fig. 20. The stop lug 425i. as shown, is secured on an upper extension 313 r of the righthand bearing plate. 33. and on its hooked end is adapted to engage with an upwardlv extended pin or lug 7T on the receiyer hook 64. The lowerend of a tripping rd T8 is attached to the intermediate portion of the said dog 7G.

A group of four spring'contacts T9, S0, 8l and 82 are supported by the case l and insulated from each other. An insulating; spacing block 83 is interposed between the free ends of the contactsSO and 81 and the lower contact 82 is provided at its `free end with an insulatingr block S1 which bears directly against and presses downward on the lower arm of the bell crank 75.

Selector actuaron- This mechanism is best shown in Figs. 9 to 1G, inclusive. Mounted in a rectangular bearing frame 85, shown a's secured to the, side plate of the case 1, is an operating shaft 8G which extends through'the 'said side of thel case and, at its outerM end, is provided with a rigidly secured operating knob Si' provided with a radiallyy Yprojectingr pointer 8S that coperates with a raduated party indicating,r dial 89 secured to the said case. This operatlng shaft ist? is capable of limited end` wise mow-ment, but yieldingly pressed inward to its normal position, shown in Fig. 11, b v a coiled spring 90 surrounding said shaft and reacting;r againstsaid frame 85 and a spur gear 91 carried by the intermediate portion ot' said shaft. The said spring Si() also acts under torsion to yieldingly resist movement of the shaft and gear 91 in the direction of the arrow marked adjacent to the latter on Fig. 11 and, when said gear and sha ft art` released, imparts return or reverse movement thereto. ln the dial 89 is a .spring-pressed pi voted dog 99. (see Figs. 11 and 1li) which normally engages with a segmental groove 93 in the hub of the knob 8T.

,This dog 92 serv-'es to limit an extreme possible movement oi' the knob and parts carried thereby, in th(l direction of the arrow marked iu Fig. 11. while the said knob is engaged with the dial Si, but permits any desired or necessary amount of return or reverse movement. 'hen the .said knob 87 and parts rarried thereinv are drawn toward the right in respect to Fig. 11, the dog 92 is rendered entirely inoperative, and such movement car# ries the gear`91 laterally into'inesh with a similar spur gear 94 carried by another -roo u nntershaft jonrnaled in the. frame 85.v lhi shaft. 95 also carries a wide faced n ratchtt wheel 9G and a cam wheel or hub 97.

This so-ealled cam wheel 97, is either made ot entire insulating material or is provided vwith a rim portion'of such material and;

in its periphery, it is formed (see F ig. 10) with a segmental notch 98 and a projecting i lug im, which parts 9S and 99 are laterally p fio l y 100 is connected by a rod 101 to one arm of wheel 9G. p connected by a rod 107 to the short upper a' hell crank 102, the other arm of which is {connected to the upper end of the rod 62 already noted. The bell crank 102 is shown as pivot'ed .to a bearing 103 Which is secured to the back of the easel. A. torsional spring 101 (sce Fig. 11') is connected at one end to the frame S5 and at its other end to the gear 94, and exerts a yielding'force which tends to resist rotation of the shaft and parts carried thereby, in the direction of the arrow marked adjacent thereto in Fig. 11. Located below the ratchet wheel 9G and piv oted to the lower portion of the frame 85 is a lever 105 `which carries a Spring-pressed driving pawl. 10G that acts upon the ratchet The free end of the lever 105 'is arm of a bell crank 108 pivcted to a suitable hearing on the side of the case 1 and provided with a long depending curved arm that is adapted to he engaged by' cam pins or projections 109 on the large gear 37 of the magneto (see Fig. 10). Backward movement of theratehet wheel 9G is normally prevented by a springpressed retaining dog 110 that is pivoted to a bearing in the lower portion of the frame '83. .\.s shown, a spring 111 vieldingly draws downward the rod 107 and parts connected thereto normally holding the same as shown in Fig. 10. Kormally both of the dogs 100 and 110 are held in inoperative position. shown in Fig. 10. h v the lower end of the dog releasing lever 112 that is intermediately pivoted to the frame S5, and the' curved upper end of which lever is normally held against a fixed stop 113 on the upper portion ofthe frame S5 by a pin 111 carried hy the. gear 91. i The stop 11.3, therefore, also limits the backward or return movement of said gear 91, under the action of the spring 90. Initial movement of said gear 91 from its normal position, how'erer, renderssaid dogs 10G and 110 operative on the ratchet, wheel 9G. Normally, a projecting pin or lug 115 on the ratchetwheel 9G engages the arm 116 of a rock shaft 118 mounted 1n the frame S5 and provided at its projecting end with, a crank 119 that is connected to the upper end of the hereinbefore noted connecting rod 78. The ex-` treme upward movement of the arm 116 is limited by a stop 120 projected from the frame 85, and this stop also serves to limit the extreme backward or return movement ried by the shaft 95. For coperation with the insulated cam hub 97 is a group of four contact brushes 121, 122, 123 and 12st, which brushes are insulated from each other and supported at their lower end by aninsulating block 125 secured to the lower portion of the framel 85. The brushes 121 and 122 are in the plane' of the cam lug 99 and the brushes 123 and 124 are in the plane of the segmental notch 98 of the cam wheel 97. Furthermore, the said brushes 122 and 124: have curved free ends thatv engage, respectively, with the cam lug 99 and notch 98 of said Wheel. The operation of this cam wheel and the said brushes will be given in the summary of the operation. vWhen the operating shaft or spindle SG is drawn out endwise by the knob 87 far enough to engage the gear 91 with the gear 9:1, it Willbe temporarily locked in that position by a spring-pressed lock segment 126 (see Figs. 11 and 12) which, as shown. is pivoted to a bracket 127 on the frame S5. The lock segment 126 is connected by a rod 127a to an armature' 12S, which latter is pivotally supported at one end and is subject to an electro-- magnet 129 (see Fig. 9). lntermediately pivotcd to a bracket. 129 on the frame S5 is a lever 130 having two short upper end arms 131 and 132 and a long laterally bent lower end which latter underlies and is adapted to engage the driving pawl 10G but not the retainingf pawl 110. The arm 131 is adapted to be engaged b v a laterally projecting pin or lng 134 on the upper gear 91, when said gear is rotated to its extreme po-` sition from normal and while it is engaged with the gear 91. Said arm 131 has an insulated tip that is adapted to engage the upper end of a spring cont-act 135 (see Fig. 12) and force the latter into engagement with the upper end of a companion contact 13G, which contacts are insulated from cach other and supported by a bracke. 13T on the frame S5 (see Fig. 13). The arm 132 of the lever 130 is curved laterally (see Figs. 11 and 13) so that it will act as a cam and its operative face is covered with insulating material 132. SupportedA by the bracket. 129 and insulated therefrom and of said ratchet wheel and other parts carfrom the lever 130 is a groupof spring conan insulating portion gages the contacts and 112 and press the same respectively into engagement with the contacts 141 and 143. W'hen the gear 91 is drawn toward the right in respect to Fig? 11, the. contact 13S will spring into engagement with the contact 139 and the contacts 140 and 142 will spring out of engagement respectively with the contacts 141 and 143. Wln the gear 91 is moved laterally into mesh with the gear 94: and is then rotated to its extreme position, thereby causing the pin 131 to engage the arm 131 and rock the lever 130, as above described, the insulated curved arm 132 engages the contact 138 and thereinv forces the said contact 138 outv of engagement withthe contact- 139 vand forces the contacts 140 and 142 again into engagement respectively with .the contacts 14:1 and 143. This engagement of the arm 132 with the contact 133 establishes the normal rela.-

, tive positions and engagements of the whole* group of contacts 138 to 143. lnclusive, but

docs not break the engagement which is es'- -tablished between the contacts 135 and 136 b v vthe above'noted engagement of the arm.

`14T the local battery, the numerals 148 and 14!) the. primary and secondary coils, re-

spcctiveljvv of the induction coil, and the numeral 150 the telephonebell. which latter is. prefcrabljr. a polariyed bell. The wires of the metallic line circuit are indicated by the letters b and c.

Sui/:awry of operatzfoa.-\Vhen a person at one of the telephones wishes tocall a party at another telephone of the s vstem, he must first rotate the knob 87, without pulling outward on the same. until the pointer S8 thereof registers with the numeral on the dial 89, which indicates the party called or the station with which communication is desired, it being. of course, understood from the description already given that the selector contact 8 of each telephone of the system i wil-l occupy a diii'erent position and that the position of each of said contacts will be represented by correspondingly positioned numerals on the said dial 89. Then the knob Si' has been rotated, together with its gear 91, to the proper selectingposit-ion above stated, the said knob is drawn outward, thereby throwing the gear 91 into mesh with the .gear 94. and in this position the said parts will then be held by the engagement of the spring latch segment. 126 with the Y 986,260 Y i 5A inner end of the shaft 86. The gear 94 be'- iliglocked, atthis time, by the lock lever 100, neither of the engaged gears 91 91 can be rotated by manipulation of the knob 87.

The selector actuator having now been t 79 fer denite 'predetermined action on the party selecting mechanism, it. is thrown into action by a rotation of the crank 11 of the magneto operating shaft 40. The initial ro! tation of said shaft 40, in theA direction of the arrow marked adjacent thereto in Fig. 1T, causes the pin 43 torun in the oblique cam slot tat and thereb)7 move 'the said shaft endwise toward the left. This endwise movement of the shaft -O is limited by engagement of the-sleeve of the crank v-11 with the hub of the gear 37, but is sufficient to cause the bell crank 61, through the connections 101 and 102, to move the lock iever 100 out of engagement with the gear 91 and thus release the latter. Also this limited movement of the shaft toward the left shifts the spring contacts 51, 551 and 57 into a position shown in the diagram view Fig. 1. Conf tinued rotation of the shaft 46, in the direction stated, causes the ratchet hub 39, by engagementwith the pin 46, to impart nearlyv one complete rotation to the sleeve 45, thereby winding up the spring 47. As already described, the. pin 46. at the limit of its movement` will be disengaged from the ratchet teeth 3.) and 'thrown into engagement with the beveled end of the dog 49 by the cam 4S, and this beveled end 50 will then hold said pin laterallyY out of engage` ment-with said ratchet teeth 39. The purpose ofwinding up this spring 17 will be more fully stated in considering the action of ringing ott of'. more accurately stated, in restoring the' line to normal condition. Under continued rotation of the said crank '41, the gear 37 drives the pinion 34 atf an increased speed of six to one,- so that the contact eccentric 35 will engage the contactl 36 three times for each time one of thepins 109 ofsaid gear 3T engages the depending arm of the bell crank 108. Hence, for each time the driving dog 106 is caused 'to impart a step of movement to the ratchet wheel 96- and'gear 94 and cam wheel 97 'which moves therewith and also to the gear 91 which is then in mesh with said gear 91, the magneto will sen'd out on the line three electrical impulses. The armature is so positioned in `respect to the eccentric contact- 35, that the electrical impulses sent out through the contact 36 and other connections to the electromag'nets 16 of the party selector, will all be in the same direction. Otherwise stated, the current sent from the magneto to said magnets 16 is an intermittentpulsating currentJ in contra-distinction to an alternating current. Further. the magnets 16 are so wound lthat. when the electrical pulsations 4are sent out by rotation of the magneto craik 41, in

i3r u i 986,260

- the direction of the arrow marked on Fig. 17V

three such movements will move the saidf contact piece a a distance corresponding. to the spacing of the perforations (see F ig. 27),'which perfor-ations represent the difference in circumferential spacingof the contact-s 8 of the different telephones of the system. The current pulsations, which are generated in the armature of the magneto,

' are delivered onto the main line, through eccentric contact 35 (which is connected to one terminal of the armature Winding), through Contact 36, wire 151, contacts 138 and 139 (which contacts are engaged b v movement of gear 91 toward the right), through Wire 152 to line wire b, from line wire 'c through Wire 153 and connected contacts l23and 12st, through wire 154 and connected contacts 57 and 5S, wire 155 and counected contacts 51 and 59, back to the a'rmature winding. As the electroinaguets 16 oall of the telephones of the system are cony nected across the mainline, through wires 156 and portions of wires 152 and 153, these electric impulses will be delivered to all of the magnets 16 of the telephone system and like movements will be imparted to the contactpieces a of all of the party selectors; but' i view of the different positions of the contacts 8, 'the said movable contact a,A of only one, of the party selectors will, at the' termination of the selecting actiombe left in contact with all' three of the contacts 4:, 5

and 8. The importance of tl1is laststat`ed fact will more clearly appear later on,

Figs. 2 and 3 illustrate diagrammatically 'the condition of the electrical connections,

respectively, at thecalling and the called telephone, at the time of ringing, and at which time the selector' at the called station has been set ufth its contact n, engaged with all three of the contacts 4, 5 and S, as shown in said Fig. 3, and the driving dog 105 has been thrown into van inoperative position,

by engagement of the pin134 with the arm 131 of the lever 130,`as ully stated in the earlier part of this description. Hence, by

continued operation of the magneto, an alternating current may 'be sent. through the bells of the instruments at the calling and called stations` through the following con- -nections, to-Wit: from lone terminal of the armature of the magneto at the callin;r station (Fig. 2), through a wire 157 and connected contact 149. and 143 and wire 1521 to connected contacts 5t and 55 and through wire 159 and bell 150 and wire 160 to ground s 161. From ground 161 through wire 160 and bell 150 of called station, through wire i 159 and connected contacts 54 and 53.

through wirev162 and connected contacts 72 and 68, through wire 163 and connected contacts 4, a and 8 of `the set party selector of the said called station, and through wire 164: and a portion of wire 153 to main line n'ire c. From the line wire c (Fig. i2) at the calling station, thel circuit is closed back to the dynamo through wire 153, connected contacts 1523 and 124, wire 154, through connectedl contacts .'57 and 58, through wire 155' and through connectingv contacts'l and 51 back to the other terminal of the armature tion. In this Way, the magneto, at the calling station. is caused to ring the bells both at the calling and at the called station or telephone, but the bells at all other stations are in norrnall \vr broken circuits and. hence, will-not. be rung. It is desirable, While ringing, toiprevcntany possibleow of current from one line wire to the other, through the selector magnets 1G and. hence, I short-circuit both line Wires, or in other words, connect the same by low resistance so that both line wires will be connected as a common 'wire or. common side ot the circuit, with the ground as the other side. r1`he line wires are thus short-circuited through connections b v heavy lines. All of the Y contacts and other parts, shown inFig. 4, are 1n the same circuiting connections are as follows: from line'xrire c to wire 153, contacts 123 andlt.. wire 154, contacts 57 and 59,'wirc 165. connected contacts 67 and G9. wire 1Go, contacts 135 and 136, wire 167 and a portion of wire 159 to 'the other line wire Z1. lt will. of

are thus short-circuitcd only in the act of ringing. After the party at-'the calling. telephone sends out the ringing signal. as above `described,he first lets go of the dynamo crank 41, and this permits the shaft l0 to more toward the right. back to its normal position, therebyvv permitting the contacts 51, V54 and 57 to assume their normal'position shown in Figs. 5 and 17. At this time, the

'ingr held b v engagement of the pin 46 with said party calling1r and thc partiy called take down their receivers 115, and this permits the respective hooks (il to move upward. thereby electrically connecting the contacts l 68. 7() and T1. at both ot the said called and i calling stations and breaking the circuit bei tween contacts 68 and 72 and between-contacts 6T and 69, as shown in Figs. 5 and 6. l 'hen this has been donc. the receivers at {the calling and called telephones. will be i connected across the main line and will Jbe in circuit with cach other. The connectior of the 'receiver at the 'calling station. with E the main line is from line wire c, contacts 123 and 124, nire 154, contacts 56 andA 5T.v

course, be understood that. the main. linesy the beveled end 50 ot` the do; 49. Next, the

windingr of said nigneto at the calling stamost easily traced on Fig. 4t and indicated position as shown in Fig. 2. The said shortspring: 147 remains wound under tension,he

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