US1901449A - Multicontact switch - Google Patents

Description

March 14, 1933. J, F D HOGE 1,901,449

MULTICONTACT SWITCH Filed Feb. 24, 1950 /NVIENTDA7 f lf-7D. HOGE qJlHudf A TTUP/VEV Patented Mar. 14, 1933 UNITED STATES PATENT oli-Fica l JOSEPHF. Dancer), or NEW YORK, N. Y., AssIeNon To BELL TELEPHONE LABonATonI'Es,

INCoRom'rEn, or NEW Yonx, N. Y., A CORPORATION oF NEW YORK i MULTICONTACT SWITCH pplicaton led February 24, 1930. Serial No. 430,472.

This invention yrelates to multi-contact switches having .carbon contacts auxiliary to certain metal contacts. Y

In switchingl units for making andbreakf 8 ing circuits o high impedance, a sparkof considerable magnitude is unavoidable, particularly when such circuit is broken. A spark of this nature quickly deteriorates metal Contact surfaces, bringing about a high resista-nce between the surfaces of brush and contact. Ordinarily the lmetal contacts of a switch arenot easily'v replaced. Therefore, in circuits of this nature ,carbon con tacts are used to supplementthe metal contacts. c It also desirable to prevent the formation. of; high resistance substances upon the surfaces of carbon contacts in order to positively'eliminateany arcing at the metal contacts. The formation of high resistance substances is ordinarily revented by imparting motion to the car ons when making and breaking. This: is vaccomplished in circuit breakers by attaching ythe carbons to the ends of a spring which is attached to ametal brush ina manner shown in Patent 841,035, issued kJanuary 8, 1907, to J. E. Morris. It is recognized by the inventor thatcarbon contacts have also been usedk ,in starting switches and multi-contact switchesas shown in4 Patent y447 ,827 issued. to Hochhousen,

March 1c, 1891, andrstent 1,473,838, issued.

to J. Driessen, November 13,1928. .Diiculty has however beenexperienced in imparting a .rubbing or wiping motion. to carboncon# tactsr used with multi-contact switches and lthus the switching arrangement'sldisclosed inthe above vpatents whichdo not have means v for setting up ajrubbing. motion between thesurfaces of the car-bon contacts are limited in .their use. 1 y

. The object of thisiinvention isrtherefore to provideV a multi-contact switch with circuitbreaker carbon contacts, one of which'is mounted on an armvmovable/for` rubbing the surfaces of ythe carbon. contactsk to remove high resistance substances fformed. on said surfaces. if y One embodimentof vtheV rpresent invention comprises .a multifcontactu,switchhaving a 59 plurality yofmetal brushes .with aplurality of metal contacts associa'blewith each brush. Each switch arm is mountedl on a separate axlev commonly controlled by an insulated bar movable in a given plane. A particular switching unithas mounted thereon a stationary carbon element and a movable carbon element,the movable carbon element being mounted in a secondary arm eccen-trically pivoted to the switch arm.A The movement of the switch arm imparts an eccentric move- 60 ment in the, secondary arm thus causing a. motionbetween the surfaces of the carbons during certain movements of the switch arm. In certain positions of the switch arm, the secondary arm is under the control of a spring which.l maintains the carbons together.Y A pin is provided on the switch arm forv disassociating the carbon contacts after the metal brush has movedl over a given number of metal contacts. v'lhecarbon contacts are T0 mounted in holders arranged for adjustment and replacement of the carbon' elements when necessary.` 1 i c, n In the illustratedv embodiment, l showsla manually controlled multi-contact V5 switch embodying this invention; Figs.y 2 and 3 show front elevations of the switch with an auxiliary or secondary switch arm in two positions; Fig. 4 shows an end elevation of the. multi-contact switch.

The assembly of the switching unit is best shown inFig. l wherein four ,switches 10, l1', 12 andy 13 kareshown, all'operated by the movement of insulated lbar, 39. u The insu# lated bar39fis connected .toa leverarm through theagency of plate 42 whichisrsecured to the insulate-d bar 39 by bolts 43--and 44. Themanner ofimparting motionto. the yswitch brushes is bestA shownin Fig. 4 wherenthe'lever 4l' is shown pivoted at 48 and operable by the movement of lever handle 47.

,spring positioning member 63 is also fastened to the insulated bar; 39 by screws 64 and 65. AThe positioning member 63 has riveted theretofa semi-spherical button 62 which may register successively withcounter-v sunk, .portions 6L on platek 60 when the brushes are resting accurately on the switch Y contacts 27,28, 2901230. Thus an operator ofthe switch. is guided in positioning the m0 l Switching unit 12 is arranged for opening s a circuit of high impedance and for this reason an auxiliary set of carbon contacts is placed in multiple with hrush'21 and contact 27. An auxiliary arm 22 carrying contact holder 26 and carbon contact 24 is controlled f by a spring 32 which causes the carbon contact 24 totouch carbon contact 25 when the brush 21 is resting on contact 27 The spring 32'is held at one end in pin 31, coiled around the auxiliary arm pivot pin and bent oveii the auxiliary arm at 38. PinV 31 and pivot pin`35 are rigidly fastened to. plate 20 of the switch arm.

It will be noted that the pivot for brush 21 Vis at 15 and that the pivot for the auxiliary arm r22fis at 35. vThus when motion is imparted tothe switch arm 20, the pin 35 re'- volves in a circula-i' bearing surface of the auxiliary arm 22 and an eccentric movement is impartedto the auxiliary arm 22 during the y time that thespring is free to hold the carbon surfaces together and untilV such time as the carbon contacts are opened. .When therarbon contacts are openedfa circular and np-y ward p movement is imparted toy they auxiliary arm.v This-will be more clearlyunderstoodby y aydetailed description ofthe related movement of the switch arm 20 and the auxiliary arm 22. Let it be assumed'thatbrush 21 is resting 'fully on contact 27; YIn this position of the switch arm, carbon contact 24 is pressed against carbon contact 25 by' spring 32 and the carbon contact 24 is in a slightly lower position than is shown in Fig. 2. lWhen z movement is imparted 'to the switch arm through the agency of lever handle 47 to move brush 21 toward contact 28, an eccentric motion .is Vimparted to arm 22 causing the suri face of carbon contact 24 to rub upwardly against the surface of carbon contact 25. This movement continuesuntil pin 31'whicli yisattach'ed to the plate of switch arm 20-is brought'to bearl against piece 34 which is an extension of the' auxiliary arm 22.l T he pressure of the pinv 31 against piece 34 operates against springl 32 to carry the Y' contact 24 away 'from' contact 25. During the breaking period of thesecontacts, the upwardk rubbing movement of 'contact 24fcontinuesl against contact 25 until the contacting surfaces `are Vactually broken. The pin 31 engagesl arm 34v immediately after brush 21 has been moved away from contact`27. Thus thehigh im# pedance circuit, which is madefby brush 21 andY contact 27, is opened yat these contacting surfaces previous to the opening of-the same circuit by the carbon contacts 24 and 25. The carbon contacts are broken as the brush 21 is moved over contact 28 to contact 29.

When insulated bar 39 is moved to the left, assuming brush 21 to be cooperating with contact 30, the carbon contact 24 makes with carbon contact 25 when brush 21 reaches a posi-V tion on contact 28 and thereafter the continued movement of switcharm '20'causes the carbon contact 24 to wipedownwardly over thesurface of carbon contact 25.

In View of the rubbing between carbon contacts, the surfaces wear and thus the carbons must be adjusted from time to time. 'lhe'adjnstment of carbon 24 canbe made by loosening screw 7 O which releases pressure on the carbon. Tn the same way, carbon 25 may be adjusted by loosening screws 71 and 72.

yThe carbons-may also bereplaced by loosen ing vthesescrews. Y

' Themanner of connecting the brushes together is indicated by connector 33 which is a coppe-r wiresoldered to terminal 36 and terminal 37. This connects the auxiliary arm electi-cally to the switcharm since terminal 36 is yfastened under the head of pinV `31 and terminal y37 is riveted toaiin 22. By reference to v' Fig. 4 the terminals for other electrical co'nnertioi'is canbe seen ex-V tending from the' terminal side of-panel 45. Terminal 50 provides a Connection tofcarboncontact 25, terminals 52, 53, 54 and 55 provide for `electrical rconnection torcontacts 27,28, 29 Vand 30, and terminal lprovidesfor an electrical connection to the switch brush 21 through the'plate 75. Brush 21 is ydesigned for balanced pressure, oneend'riding'o'n the surface of plate 7 5 and the otherendriding onpthe surface of c`ontacts'27 toi`-30 inclusive.

connector similar to 33 may be soldered to terminals 50 and 52 for 27 and 25together. c

It is not intended that the invention be limited to the specific structure and electrical connecting contacts circuit arrangement Vdisclosed and described.

What is claimed is: y, Y, 1. In a multi-contact switch, a brush guiding member 'having an axlepivoted kto asta` tionary support, a metal brushfastened vrigidly'to said member, a secondary arm ing a separate axle bearing, a carbon Contact attached to saidv secondaryarm, an axle'pin" for said secondary arm' rigidly attachedto said guiding member in a position to eccen trically pivot said secondary arm, a series of stationary metal contacts arranged to contact with said metal brush, a stationaryrcarbon contact arranged to contact with said secondary arm carbon, contact, a tension springfor holding said carbon contacts'together, means to move said guiding member to wipe said metal `brush lover lIsaidfmetal contacts and thereby rotate said axle pin'in saidhsecond-` ary arm bearing for wiping the vsurface of said secondary carbon contact over the surface of said stationary carbon contact dur- Y ing a period of rotation of said brush guiding member, a stationary pin mounted in said guiding member, and an extension on said secondary arm for engaging said pin to open said carbon contacts.

2. In a mu1ti-contact switch, a brush guiding member having an axle pivoted to a stationary supporting member, a series of metal contacts radially mounted on said stationary support and having said axle as a center, a metal brush fastened rigidly to said guiding member having the end associated with the contacts diagonally intercepting the radii on which the contacts are mounted to provide a two-directional movement over said contacts, a secondary arm having a separate axle bearing, a carbon contact attached to said secondary arm, an axle pin for said secondary arm rigidly attached to said guiding member in a position to eccentrically pivot said secondary arm, a stationary carbon con-tact arranged to contact with said secondary arm carbon contact, a tension spring for holding said carbon contacts together, means to move said guiding member to wipe said metal brush over said metal contacts and thereby rotate said axle pin in a circumference having said primary axle member as a center for wiping the surface of said secondary arm carbon contact over the surface of said stationary carbon contact during a period of rotation of said brush guiding member, a stationary pin mounted in said guiding member and an extension on said secondary arm for engaging said pin to open said carbon contacts.

In witness whereof, I hereunto subscribe my name this 17th day of February, 1930.

JOSEPH F. D. HOGE.

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