US977536A - Automatic switch for telephone systems. - Google Patents

Description

(I. H. NORTH.

AUTOMATIC SWITCH FOR TELEPHONE SYSTEMS.

APPLICATION FILED DBO. 8, 1908.

977,536. Patented Dec. 6; 1910.

4 BHEETSBHEET 1.

. C. H. NORTH. AUTOMATIC SWITCH FOR TELEPHONE SYSTEMS;

Patented Dec. 6, 1910.

APPLICATION FILEHDEO. 8, 1908.

O. H. NORTH.

AUTOMATIC SWITCH FOR TELEPHONE SYSTEMS.

APPLIOLTION FILED DEC. 8, 1908.

- Patented Dec. 6, 1910.

4 SHEETS-SHEET 3.

Enoentoz Mwwzm.

4 G. H. NORTH.

AUTOMATIC SWITCH FOR TELEPHONE SYSTEMS.

APPLIOATIQN FILED no. 8. 190a. E

. I Patented Dec. 6, 191 0.

4 SHEETS-SHEET 4.

Bl IHII To all whom 'it may concern:

UNITED STATES PATENT or-"FIoE.

CHARLES HOWARD nonrn, or CLEVELAND, onro, ASSIGNOB 'ro THE-NORTH ELECTBIG I COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

AUTOMATIC SWITCH FOR TELEPHQNE SYSTEMS.

Specification of Letters Patent.

Patented Dec. 6, 1910;

Be it known that I, CHARLES NORTH, a

citizen of the United States, residing. at

Cleveland, in thecounty of Guyahoga and State of Ohio, have invented certain new and useful Im rovements in Automatic Switches for Telephone Systems, of whlch the following is a, specification, reference being had therein to the accompanying drawfi ly invention relates to so-called automatic switches for telephone systems, that is to say'switches employed to effect connection between different lines or circuits, by mechanical means electrically controlled.

It has particularreference to such switches as are used in telephone systems for selectively connecting a given circuit with any one of a number of other circuits. The switches heretofore emloyed for this purpose are well exem 1i ed in Patents Nos.

815,176 and 815,321, granted to Keith-and- Erickson March 13, 1906.

The object of my invention is to produce air, as well as decrease the costof-"manuac'ture, I make 'these magnet structures interchangeable units,

Various other points of improvement will sufiiciently a pear from the detailed descrip'- tion hereina ter and the appended claims.

My invention is illustrated in the accompaiii ying drawings wherein; igure 1 is a side View of a switch embodymfg rpy invention; Fig. 2 is a rear view thereo 3 is a plan view of the'same;

Fig. 4 1s a plan view of one electromagnet u mt removed from the frame; Fig. 5 is an end view thereof looking in the direction of the arrow in Fig. 4, and showing a-latch unit being the rotary magnet; Figs. 6 and 7 v for t e release movement, this particular method of -inserting and securing the springs therein. Fig. 10 is a detail view of a modification-for the adjustable pawl stop.

Referring to the drawings, 1 represents a plate upon which the different parts of the switch are mounted. Upon the back of this plate are-secured the banks 3 and 4, and upon the front of it a frame 2 carrying the spindle 5 with its wipers, the'operating magnets 6 and 7, and the release magnet 8. The banks '3 and 4 are alike in their construction and a brief description of one will sufiice for both. The bank 3, therefore, consists of ten straightvertical rows of'ten pairs of contacts each, heldin a body of insulating material, and clamped between side plates 3 and 3', each of which is provided with ears 3, through which serews3 are inserted to secure itupon the plate 1. The body of insulation 3, is preferably built up of layers or curved strips of a'suitable insulating composition, but it may be molded solid, the

contacts in that case being set in the die and the composition molded around them. Where the strips are employed, they are slotted or grooved to receive the contacts, which are placed ,therein as indicated in Figs. 8 and 9, and then the successive strips piled u from the bank. Vhere the slots are ma e exactly the same width as the contacts, however, there is a tendency for the latter to work loose, and I remedy this by having the strips molded with the slots from .003 to .008 of an inch shallower than the width of the springs. The contacts'being insulated and the strips piled up", the top and bottom ' plates 39 and 3 are put in position the screws 3 are inserted assin 7 1 from the top to the bottom plate and tappe i into the latter, the bank is placedin an oven and'heated sufliciently to soften the compo= sition'a little,'-and then by ti screws or otherwise forcing the plates 3*" and 3? together, the contacts will be forced into the substance of each strip, both above and below, until the surfaces of the strips meet, thus insuring an absolutely tight gri In Fig. 8 I have shown each contact 3'? wit a small return bend in it at 3*, but'with a straight tail on the outside of the bank. The bend 3 is for the purpose of. preventing hteni'ng the longitudinal displacement outwardly and to I coiled spring is secured at. its inner end upon prevent the same inwardly. I may adopt either ofthe two expedients shown in Fig. 8, one on the left hand side, where the contact is giyen aquarter turn outside the bank, the other on the right. hand, where it is given a straight otlset or bend. on the outside. These two methods may be combined if desired, and it will be observed Fig. .l that the offset at 3". ailords an op 'iortunity to increase the insulation between the respectivecontacts by setting the offset in opposite directions in alternate rows and by setting it oppositely for each pair if desired. The contacts are all placed with their surfacc'svertical and the wipers are slipped around beneath the. rows of contacts until the desired row is reached, and then pass up that row. This it will be observed is a reversal of the method employed in the Keith and Erickson switches hereinbefore referred to. In those and in all of the Shrewger switches the movement is up to the row and then around the row, the contacts being arranged with theirtiat surfaces horizontal. The vertical arrangement, however, I consider to be better, because it makes the contacts self-cleaning, which is an important point' in apparatus of this character.

The frame 2 consists of a finislied white metal'or similar casting having a vertical straight-faced member or body 2, with upper and lower attaching arms 2 and 2 respectively. Carried upon suit-able forward extensions 2 2 and 2*, are frontmounting plates 2, 2 and 2". These are of course connected by suitable webs or flanges in casting so that the whole frame is )roperly braced without superfiuous metal. The arms 2 have an intermediate horizontal web..2 carrying the upper bearing for the spindle 5, and an extension 2 of this web carries the'vertical and rotary cutofi' contact springs 9 and 10 which are actuated by thespindle' as it returns to its zero or. normal position A similar web at the bot-tom f the frame carriesthe lower bearing for the spindle,-these .bearings belng formed in i separate collars or bushings inserted through op'enings'molded in the webs ofthe frame.

The spindle 5 slides vertically and also rotates 1n the bearings 5 and 5 This vertical or sliding movement is produced by means of a rack 5", best-shown in Fi s. 1, 6 and 7. This rack does not turn with the spindle, but has upper and lower collars 5 and 5 through which the spindle passes and through which it turns, these collars lying between fixed collars. or sleeves 5 and 5 secured 'upon the s indle in any suitable we as by means of t epins 6. The upper col ar 5 carries the rota-r ratchet 5, and the lower collar 5' carries t e casing 5" with- .in which the coiled spring is carried for re-,,

storing the switch to its zero position. This the spindle and its outer end to the casing 5" as indicated at 5 in Fig. 1. The casing carries the pin 5 which slides along the edge of the frame 2 and thereby keeps the tension of the spring constant for all vertical positions. The rack 5 has its teeth formed in a peculiar way. Instead of each having one long inclined face and one short face, as usual with ratchet teeth, they are formed by merely milling out or casting in the rack a succession of approximately semicircular openings. The pawl 7 cooperating with these teeth, and which ,is' shown in e'n-- gagement therewith in Fig; 6, has not the usual sharp nose, but instead has a squared end, with a slight projection/7 adapted to fit into the curved indentations in the ratchet. the wear on the parts, and secure it strong grip or engagement between them. The retaining pawl for the vertical ratchet, and the teeth which cooperate with it are on the side thereof as shown at 5 in Figs. 6 and 7, and are of the ordinary conformation.

Cooperating with both the rotary and vertical ratchets is a. double detent dog' '11,

pivoted at 12 and having an upper straight member 11 engaging the rotary ratchet,-a lower hooked pawl 11 engaging the side ratchet 5 on the vertical rack, and two tails 11 and 11 the former engaged by theend of the armature lever 8" of the release madgnet 8, and the latter'adapted to engage an to beheld by'alatch. 6 pivoted on the frame G of the rotary. magnet (see Fig. 5).

In operation, whe nthe releasemagnet is energized, the lever 8 is thrown over (to the right in ig. 2), the tail 11 of the dog 1.1 is thrown with it and engages the latch 6, being held thereby so that in case the release magnet is denergized before the By this construction I minimize release switch is fully restored, the dog will not be released, and the comple'te r'estoration of the switch will notbe interfered with. The latch 6" is a bell crank pivoted at its'angle and normally heldin latching position by ajspring 6 bearing upon-its I tail 6. The armature lever 6 of the; rotary magnet is the first to-move when the switch is actuated, and its first movement, lifting the tail of the latch, releases the dog Il, and permits the pawls 11 and 11*.to engage their respective ratchets and thereby properly.

perform every function of holding thespin dle in a position to which itniay he stopped and until it is again released.

The three magnets 6', 7 and 8 are made-as identical and interchangeable units.

the several magnets, as well asease-and efli- I be lieve that I am the first to succeed man-.-

port for the armature.

ciency in maintenance, since the removal of a magnet and the substitution of a new one therefor is but the affair of a. moment. The only difference then between the rotary and vertical units, and the release unit, hes in the provision of a differently shaped pawl, and in the case of the release unit of no pawl at all.

It will be observed in Fig. 1 that the bifurcated end of the lever 8 is open, serving to strike, against the inclined tail 11 of the 'detent do In Fig. 4 I have shown one unit detacl ed, its armature lever being fitted with a pawl. A description of this unit will suffice for all the units, and as Fig. 4 is a plan view only, reference may be had.to any of the units in the other figures to supplement this illustration. For the purposes of this description we will assume that Fig. 4 represents the rotary unit 6. This mounted on a. frame plate 6", which may be of iron or other suitable metal.

The two magnet cores 6' are secured to the plate by screws 6 (see Fig. 5), and are provided with an iron yoke 6, if the frame plate is of non-magnet c metal. Along one side of the electromagnets lies an extension member of the frame, 6*, constituting a sup- This armature is formed of a plate of soft iron 6 with an aluminum bell-crank lever 6 riveted to it. A long arm 6 of this lever constitutes the continuation of a rib formed up in the aluminum body, and as the lever is beveled off at its end, a bifurcation results, as indi cated at 6, the two sides'ofthe. lever forming cheek pieces for the reception of the awl 6 normally held with its oint outy the s ring 6", extending from he tail of the paw at 6 to a. fixed stud 6 Where the unit is to be used for release, as indicated at 8 in Fig. 1, the pawl, spring, and stud are omitted. p

The armature plate 6 is scored across.

near the top, so as to'take over the knifeedge 6, formed on a tapered plate 6?, secured upon the top of the frame barb by screws extending through washers and slots in the taper plate. The inclined edge of this.v

plate rests against a shoulder 6 formed on the frame plate, and adjustment of'the armature to and from the cores is readily accomplished by loosening the screws and slid ing theplate laterally, this motion being permitt by the slots, and the plate 6 restmg against the shoulder 6 in all positions,

so that all strain and wear is taken up by the frame plate. The arrangement of this shoulder andthe strip are well shown in Fi 1, where the ma site at 7 is presentedfin elevation. It should be noted that Fig.

5 shows the unit turned upon its side, with the top tothe left, as indicated by the arrow in that figure;

The armature, and thebell cra'nk lever 6? ceeding tooth. Fig. 2 shows the adjustable maybe raised or lower'e throw of the pawls 6 and 7 of the rotary' and ,vertical magnets res ectively, by fitting slides to the frame mem er 2, as indicated in Figs. 1 and 2. It is particularly important ,that the motion of the actuatingpawls be positively limited, in order to avoid any over throw, and to positively with-draw each pawl from its ratchet when its armature retracts, so that it may fall into the suclimiting plate or slide for the vertical pawl. which is marked 6- in that figure and 7* in Fig. 1. By loosening the holding screws, and slidin theplate slightly from side to side, the edges of the op ning y in the plate d as required.

In operation, when the pawl is thrown up by the action oft-heimagnetits nose 7 is forced into one of the indentations in the with it. 1 As the upper edge of the pawl comes against the upper end of the opening vertical ratchet, so that it carries the spindle throwing, or moving more than the single step intended. As the pawl drops, its lower edge strikes the lower edge of the opening 3 and it slides out, tensioning its spring 6, ready to engage the next tooth if the magnet is again energized. This transverse plate may be made in two parts, or ratheutwo separate plates for upper and lower stops of the pawl 7 may be provided, the upper one presenting its lower edge to the pawl, and the lower one its upper edge, assho'wn in Fig. 10. These adjusting plates are all of steel, may be case-hardened, and afford a means for very accurate. adjustment of the parts and of their movements. I consider that the broad rinciple involv'ed in the use of these plates 1s original with me, and that they formimportant elements of't-he switch structure, hence I shall claim. the samelaccordingly. In assembling this switchytheframe 2 secured to the plate 1 through the medium of short posts 12, by.screws passin through the ends of the arms 2 and 2 T e length of these, posts is, sucli that when the screws areset up, the spindle 5 is centered with regard to the ourvlitur'ejof the 'Ibanks, so

that its wipers 5 and 5 (see Fi s. l and 3) i as identical and interchangeable self-con will cnga e il'h, contacts 1n the anks when the spind e is ro ated by the magnet 6 and raised by the magnet 7 In operation the magnet 6 works first, turning the spindle until the wipers w and :13 come under the desi d row of contacts, the spindle being held in position by the nose 11 on the dog 11, engaging the rotary ratchet 5 The spindle and its wipers are then raised step by step through the agency of the magnet 7, until the wipers rest upon the desired contacts in'the row selected. The switch is adapted to be used for any purpose, and in any circuit, eitheras a selector or connector. To restore it to zero, the magnet 8 is energized, attracting 'its armature and causing the end of its lever 8 to force over the tail 11 of the dog 11 until the tail 11 engages and is held by the latch 6* on the rotary mounting plate. The detents 11 and 11 are then disengaged from the respective ratchets 5 and 5, and the spindle drops of its own weight until the wipers have cleared tlie j- -if'ou with which they were engaget l, after which the spring in casing 5" turns the spindle back to the zero position in the drawings.

For convenience in making connections, I provide aset of jacks on the lower portion of the plate 1, as indicated at 15, cooperating blades 16 being carried on the lower part of the frame '2. The jack springs 15 are mounted in an" insulating strip and extend through to the back ofthe plate for ready access in wiring, and'the upper ends of the blades 16 are notched for connection to the terminal wires of the magnets and the wipers. I

I am aware that some changes may be made in matters of detail in this structure,

without affecting the design or the essential, features of my invention. I wish it thoroughly understood'that all such non-essential changes ormodifications are contemplated by me, if Within the scope of the appended claims. Having thus described my invention, what I claim and ilesire to ---ecure by Letters Patent of. :the State), is: p

1. An automatic switch comprising'rela- 'tively fixe'd "contacts, a relatively movable selective eontact, and a plurality of electroma nets havingm'echa-nieal connection with am control: of said movable contact, all of;

said electroma net structures being identical and micro angeablej units.

.2. In an electrlcal swltch, a contact bank,

. a cooperating wiper, and a plurality'of e'lec-- 'tr'omagnets controlling the l wiper, each of said magnets.comprising'- azpain'o'f spools, a

frame, an armatgreand, armaturelever, and

means alto-the 'end'of the lever for attachin" lel-pawl,- and "all of said-magnets being mad:

ofmagnet cores and spools wit tained units. I

3. In an electrical switch, relatively fixed contacts, a relatively movable cooperating contact, and a plurality of e'lectromagnets to control said movable contact, all of said ma nets bein identical and interchangeable sel -containe units, and each comprising, a frame, a pair of cores carrying spools there on, a knife-edge on the frame adjacent to the ends of the cores, an armature fulcrumed on the knife-edge and extending across and in juxtaposition to the cores, and an armature lever extending forwardly parallel to the cores and beyond the frame with retracting. springs secured to the frame.

4.111 an electrical switch bank contacts and a coiiperatin-g movable wiper contact, with a plurality of controlling magnets therefor all formed as self-contained identical and interchangeable units, and each comprising a frame or return bar with an end plate for attachment to the switch frame, a pair of cores and magnet spools mounted on theend plate with a suitable connecting yoke, the cores extending parallel to .tlre frame a knife-edge on the frame adjacent to the free ends of the cores, an armature fulcrumed upon said knife-edge, a

rality of identical and interchangeableselfcontained actuating and controlling elements for said ratchets, each comprising the following instrumentalities: a separate frame, a pair of magnet cores and spools thereon, an adjustable knife-edge, an armature fulcruined on'the knife-edge, an armature lever extending from above the knife-edge to beyond the end of the frame, means for attach ing an actuating pawl to said lever and re" traeting s rings for the armature serving alsoto hol 'crum.

(5. In an electrical switcln' relatively fixed the same in position u'ponits fuland relatively movable contacts, and a plu' rality of electromagnets for producing variable eoiirdination between sald contacts, said.

electrom'agnets being identical and interchangeable self-contained units, each com- .prisin the following instrumen alltieszay- 125 a suitable;

frame' having a right angle end iece, a pair ma n'et-ic yoke mounted uponv the end piece ant? extending parallelw'ith the frame, an

an armature lever of greater length than the frame ext-ei'iding over the top thereof and bifurcated at its end toreceive an actuating pawl, and a pair ofhelical springs secured atone end to the frame. and at the other end to the ari'imtureabove the knife-edge, Whereby the lever is normally maintained in a depressed position, and the'armature is kept upon its fulcrum.

7. In an electrical-switch, relatively'fixed and relatively movable contacts, and, a plurality of actuating electromagnets therefor constituting identical and interchangeable units, each comprising a core and spool, a frame, and an armature and retracting springs therefor, and a knife-edge fulcrumed for the armature consisting of a tapered strip of hardened steel with a straight knifeedge and an inclined back, together with slots extending parallel to the back, and screws in the same securing the strip on the frame, with its inclined back resting a ainsta complementary inclined shoulder or ange formed on the frame, whereby lateral movement of the strip will'result in longitudinal adjustment of-the armature to and from the magnet cores, and when set the parts may be locked on the frame, with the back of the strip against a solid abutment to take up all shocks of pounding. H

In testimony whereof I aflix my signature in presence of two Witnesses.-

" CHARLES HOVARD NORTH.

\Vitnesses: 4

GEO. H. FISTER, I

EDWARD E. CLEMENT.

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