US1790690A - A corpora - Google Patents

A corpora Download PDF

Info

Publication number
US1790690A
US1790690A US1790690DA US1790690A US 1790690 A US1790690 A US 1790690A US 1790690D A US1790690D A US 1790690DA US 1790690 A US1790690 A US 1790690A
Authority
US
United States
Prior art keywords
contact member
movable contact
movable
interrupter
bar
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Publication date
Application granted granted Critical
Publication of US1790690A publication Critical patent/US1790690A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02BBOARDS, SUBSTATIONS OR SWITCHING ARRANGEMENTS FOR THE SUPPLY OR DISTRIBUTION OF ELECTRIC POWER
    • H02B11/00Switchgear having carriage withdrawable for isolation
    • H02B11/02Details
    • H02B11/04Isolating-contacts, e.g. mountings or shieldings

Definitions

  • This invention relates to circuit-interrupt ers of the truck type and to auxiliary switches especially adapted for use in connection with such interrupters, although not 5 necessarily limited to such use.
  • a truck-type circuit interrupter is usually electrically-operated and so carries closing y and opening coils, as well as various circuitcontrollers arranged to change the condi 10 tions of various circuits when the interrupter opens and closes.
  • the interruper is adapted to be rolled into a cell and automatically to establish connection with the circuit it is adapted to control and to break such connection when being withdrawn fromthe cell.
  • Auxiliary switches are also provided, the movable components of which are carried by Athe interrupter, and these switches are adapte-d automatically to connect and dis- 9 connect the opening and closing coils, and other accessory devices, with and from their various control circuits at the insertion or removal of the interrupter.
  • a single interrupter may have a large number or" auxiliary 5 switches associated with it.
  • An obj ect or this invention is the provision f of an auxiliary switch having a yieldingly supported movable contact member so constructed and arranged that it has a wide range of yielding movement, thereby torestablish good electricalfcontactvwith its cooperating fixed member regardless of relatively great departures from their relative designed positions.
  • a further object is the provision oi' a truck typeV switch provided with an auxiliary switch having a movable contact member which is self-seating on its cooperating mov- -V' able contact member, *whereby to have a bear ing thereon over practically its entire contact-'area regardless of a considerable departure from the intended settings of the contact members.
  • a further object is generally to improve the construction and operation of electric switches.
  • Fig; l ⁇ is a side elevation of a truck-type circuit interrupter with an auxiliary switch embodying this invention associated with it.
  • Fig. 2 is a detailed side elevation illustrat ⁇ ing a gang of auxiliary switches embodying theinvention.
  • Fig. 3 is a sectional view taken along line 8-#3 ot Fig.2.
  • "i 7 Fig'. 4 is a side elevation components of the auxiliary switch.
  • F ig. 5 is a'view similar to Fig. 4: but illus/7 trating how the contact members preserve v full contact when their ysupporting structures are out of line.
  • the circuit interrupter withl which the auxiliary switch embodyingV this invention is adapted especially to be associated includes the enclosing casing 10 which is mounted on wheels 12 and is adapted to roll on a track 14 into and out of an enclosing' cell 16.
  • the terminals 18 and 2O of thevinterrupter are provided with disconnecting contact members 22 and 24 which are adapted detachably to engage the stationary disconnecting co-ntact terminals 26 and 28 of a power circuit.
  • the arrangement is such that when the 'interrupter is moved into the cell, the said contact members are caused to inter-engage and cally with the power circuit, and when the interrupter is moved outwardly, its connection with the power circuit is interrupted.
  • the interrupter here shown is electrically operated and has a closing magnet 30 and aniopening magnet 82.
  • a circuit-controller 34 is or may be provided, also, for giving remote indications of the conditions of the interrupter and for otherwise altering the conof the movable thereby to connect the interrupter automatief dition of suitable circuits. 11i?
  • Auxiliary switches embodyingthe pre-sent invention are provided for automatically making and disconnecting thev'variou's -cir-.
  • Said plate has a flat circuits forv the opening and closingcoils and for the circuit controller, when the circuit interrupter is moved into and is withdrawn from operative position within its enclosing cell.
  • the movable components of the auxiliary switches are mounted, in spaced parallel relation with each other, on an insulating bar 36, which bar is disposed horizontally above the interrupter in the upper front portion of the cell, when the interrupter is therein, and is supported rigidly in position by means including a ⁇ frame 38 carried by the interrupter.
  • T he stationary components of the auxiliary switches are carried'byV a similar bar 40, which bar is attached rigidly to the cell structure in such vpositio-n that it is vertically spaced above the bar 36, when the interrupter is in operative position within the cell.
  • the stationary contact member comprises mainly a fla-t plate 42 whichY is attached to the lower Jface oft'said upper insulating lbar 40 by any suitable horizontal lower surface which is adapted to be engaged by the movable contactmember.V
  • the front end of said plate is provided with an Lip-turned lip 46 ⁇ which serves toy guide theV movable Contact member onto the lower contact face-of the plate.
  • the rear end of said lplate is provided with a similar lip 48 which is lprovided with attaching means 50 for a circuit lead 52.
  • the plate preferably is symmetrically ormed so that either lip may be lplaced in front.VV
  • Each bracket comprises the spaced and parallel side walls 58 which are outwardly extended from a connecting wall 60 which is integral with said side walls.
  • Attaching bolts 62 may pass through said walls 60 of both brackets and through the insulating supporting bar 36, whereby to secureall together.
  • Said walls 58 are extended upwardly and outwardly .toa point above the top of said bar 36 and pivot pins 64 pass channel member 7 6 which has the flat upper through said walls.
  • Link-members 66 and 68 are supported on said pins.
  • Said linkmembers ' are identical. Each comprises a channel-member having the spaced and parallell side-arms 70' and the integrally-connected Vwall 7 2.
  • Said side-arms 70 are formed with yslots 74 therein which lie along the length of .said arms, at the outer ends thereof, and in which slots said pivot vpins 64 are loosely received.
  • the movable contact me1nberisaclapted to be carried by the proximate ends of saidlink-members.
  • 4Saidmovable contact member comprises a wall 78 ⁇ and the deoendino ⁇ and inte rall connected side walls'SO.
  • The-proximate ends. of said link-members are disposed betweenl said side-walls and are pivotally connected loosely to the opposite ends ot said walls by pivot pins 82.
  • Coiled springs 84 encircle said pins 82 and the ends ot said springs bear upon the walls 7.2 of the link-members and also upon a pin S6 which is carried by said walls 8O and disposed between the proximate ends ot said link-members.
  • the arrangement ot said springs is such as to maintain the movable contact member yieldingly in its most elevated position, as shown in Fig. 4, in which position the bottoms of the slots 7 4 in the linkmembers are brought up against the pins 64, which restricts the structure from furthe-r movement under the action of said springs.
  • the movable contact member is provided with a iiatupper face which is adapted to seat upon the flat lower :tace of the fixed contact member, when the two are in proper engagement.v
  • the movable contact member is also provided with depending end-lips 88 which cooperate with the lips 46 and 48 of the livxed contact member in guiding the movable contact member to position against the fixed contact member.
  • A. flexible conductor ⁇ 90 is secured to the movablecontact member, by solder or othera loose connection between the link-members and thepivot-pins 64, the movable contact member may have, also, a suitable amount of side-wise movement in ⁇ both directions. It has, therefore, a universal support, and so can align itself with the iixed contact member, under all usual conditions encountered in practice.
  • the movable components ofthe auxiliary switch above set forth are adapted to be moved in a horizontal line intorand out of engagement with the stationary contact member, as the circuit interrupter is moved into and out ofi its enclosing cell.
  • rihe movable VContact member when withdrawn from contact engaging position, normally is supported in-a position which is higher than its contactengaging' position.
  • the rear lip 86 engages with the forward lip 4G-of the iixed contact member and fso inclines'the movable contact member downwardly.
  • a cooperating movable contact member disposed transversely above said lower support having de-f pending spaced side walls, a pair ofV arms disposed beneath and extended in opposite directions beyond said contact member, said arms comprising channel-members having in- ⁇ tegral upstanding spaced side walls received between the side walls of said contact lmember, pivot pins carried by the walls of saidy contact member, at opposite ends thereof, and passed loosely through the walls of said arms, at the upper ends thereof, springs encircling said pivot pins and having separate bearings on said arms and also on said Contact member, separate opposed brackets carried by said lower support on opposite sides thereof andV having integral upstanding spaced side walls, between which the free lower ends of said arms are received, said arms having longi-v tudinally-directed opposed slots in the lower ends of the walls thereof, and pivot-pins carried by the walls of said brackets passed freely through said slots.
  • a stationary contact member attached to and transversely of the insulating bar including spring means bearg ing on said movable contact member and separately on each of Vsaid links in a direction to urge them in opposite directions and thereby toyu'rge said movable contact member upof said upper insulating bar having a fiat horizontal intermediate section and upward@V ly inclined end sections, one of said inclined end sections constituting a terminal, of the circuit controller ,and having attachingv means for a circuit conductor, a cooperating movable Contact member carried by Asaid member having a flat -intermediate section engageable with the-fiat sectionrof said stationary contact member and downturned walls at the sides of said intermediate section and downwardly inclined sections extended from the ends of said intermediate section and cooperating with theupturned end sections of said stationary contact member, fand yiis V'12o lower insulating bar and transversely above v the upper face Vthereof comprising a channel Aie Lwalls of said stationary contact member
  • said lower bar being movable horizontally into and out of circuit controlling position with respect to saidupper-bar, a stationary Contact member carried by and secured to the lower face ofrsaid upper bar, a movable contact membercarried by and located transversely above said lower bar, said movable contact member comprising a channel-shaped member having a flat intermedi- Vate vContact section and downwardlyV inclined sections located at the opposite ends of said contact section and having downwardly directed opposed side walls, support- 'ing inea-ns for said movable contact member.v including independent brackets having flatA intermediate sections and integral parallel spaced walls which upstand above said intermediate sections,
  • brackets on opposite sides of said lower bar, links connecting said brackets and said Amovable contactemember having intermediate sections and upturned integral side walls, the ends of which are located between the upstanding'sid'e walls of said brackets and the dewnwardly extended side walls of said movable contactmeniber, said links having pin and slot connections with the side walls et said brackets, pivot pins passedfseparately through the ends of said links and the side abutment pinl locatedr between said pivot pins and carriedv by the side walls of said lmovable Contact member, and means supporting said movable vcontact member 'yieldingly in elevated position above said lower insulated bar including springs separately encircling the combination of upper and lower insulating'.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Push-Button Switches (AREA)

Description

Feb. 3, 1931. T, M WOQD i 1,790,690
AUXILIARY SWITCH Patented Feb. 3, 1931 Prior.
TECH/IAS v. W'OOD, OF BOSTON, MASSACHUSETTS, ASSIGNGR TO CONDIT' ELECTRICAL MANUFACTURNG CORPORATION, OF SOUTH IBOSCLON', MASSACHUSETTS, A CORPORA- TION OF MASSACHUSETTS AXILIARY SWITCH y Application led March 4, 1926. Serial No. 92,371.
This invention relates to circuit-interrupt ers of the truck type and to auxiliary switches especially adapted for use in connection with such interrupters, although not 5 necessarily limited to such use.
A truck-type circuit interrupter is usually electrically-operated and so carries closing y and opening coils, as well as various circuitcontrollers arranged to change the condi 10 tions of various circuits when the interrupter opens and closes. The interruper is adapted to be rolled into a cell and automatically to establish connection with the circuit it is adapted to control and to break such connection when being withdrawn fromthe cell. Auxiliary switches are also provided, the movable components of which are carried by Athe interrupter, and these switches are adapte-d automatically to connect and dis- 9 connect the opening and closing coils, and other accessory devices, with and from their various control circuits at the insertion or removal of the interrupter. A single interrupter may have a large number or" auxiliary 5 switches associated with it.
Considerable diiliculty has been experienced in maintaining goodalignment between the separable contact members ont the auxiliary switches, and in maintaining lgood 39 and reliable vcontact between the contact members thereof, due to variations from specified dimensions in assembly wear and the like'and especially due to the impracti- Vcability of working tol accurate dimensions in pouring the cement of the cell construe tion.
An obj ect or this invention is the provision f of an auxiliary switch having a yieldingly supported movable contact member so constructed and arranged that it has a wide range of yielding movement, thereby torestablish good electricalfcontactvwith its cooperating fixed member regardless of relatively great departures from their relative designed positions. v
A further object is the provision oi' a truck typeV switch provided with an auxiliary switch having a movable contact member which is self-seating on its cooperating mov- -V' able contact member, *whereby to have a bear ing thereon over practically its entire contact-'area regardless of a considerable departure from the intended settings of the contact members.
A further object is generally to improve the construction and operation of electric switches. Y
Fig; l` is a side elevation of a truck-type circuit interrupter with an auxiliary switch embodying this invention associated with it. Fig. 2 is a detailed side elevation illustrat` ing a gang of auxiliary switches embodying theinvention.
Fig. 3 is a sectional view taken along line 8-#3 ot Fig.2. "i 7 Fig'. 4 is a side elevation components of the auxiliary switch.
F ig. 5 is a'view similar to Fig. 4: but illus/7 trating how the contact members preserve v full contact when their ysupporting structures are out of line.
The circuit interrupter withl which the auxiliary switch embodyingV this invention is adapted especially to be associated includes the enclosing casing 10 which is mounted on wheels 12 and is adapted to roll on a track 14 into and out of an enclosing' cell 16. The terminals 18 and 2O of thevinterrupter are provided with disconnecting contact members 22 and 24 which are adapted detachably to engage the stationary disconnecting co-ntact terminals 26 and 28 of a power circuit.
` The arrangement is such that when the 'interrupter is moved into the cell, the said contact members are caused to inter-engage and cally with the power circuit, and when the interrupter is moved outwardly, its connection with the power circuit is interrupted.
The interrupter here shown is electrically operated and has a closing magnet 30 and aniopening magnet 82. A circuit-controller 34 is or may be provided, also, for giving remote indications of the conditions of the interrupter and for otherwise altering the conof the movable thereby to connect the interrupter automatief dition of suitable circuits. 11i? Auxiliary switches embodyingthe pre-sent invention are provided for automatically making and disconnecting thev'variou's -cir-.
`cuits associated with the interrur)ter1 as the .1. fil) meafns as the screws 44. Said plate has a flat circuits forv the opening and closingcoils and for the circuit controller, when the circuit interrupter is moved into and is withdrawn from operative position within its enclosing cell. The movable components of the auxiliary switches are mounted, in spaced parallel relation with each other, on an insulating bar 36, which bar is disposed horizontally above the interrupter in the upper front portion of the cell, when the interrupter is therein, and is supported rigidly in position by means including a` frame 38 carried by the interrupter. T he stationary components of the auxiliary switches are carried'byV a similar bar 40, which bar is attached rigidly to the cell structure in such vpositio-n that it is vertically spaced above the bar 36, when the interrupter is in operative position within the cell.
The auxiliary swtiches are identical in construction and the construction of but one need be described. The stationary contact member comprises mainly a fla-t plate 42 whichY is attached to the lower Jface oft'said upper insulating lbar 40 by any suitable horizontal lower surface which is adapted to be engaged by the movable contactmember.V
The front end of said plate is provided with an Lip-turned lip 46` which serves toy guide theV movable Contact member onto the lower contact face-of the plate. The rear end of said lplate is provided with a similar lip 48 which is lprovided with attaching means 50 for a circuit lead 52. The plate preferably is symmetrically ormed so that either lip may be lplaced in front.VV
'1l-he Vmovable switch member includes two brackets 54 and 56. Each bracket comprises the spaced and parallel side walls 58 which are outwardly extended from a connecting wall 60 which is integral with said side walls. Attaching bolts 62 may pass through said walls 60 of both brackets and through the insulating supporting bar 36, whereby to secureall together. Said walls 58 are extended upwardly and outwardly .toa point above the top of said bar 36 and pivot pins 64 pass channel member 7 6 which has the flat upper through said walls.
Link- members 66 and 68 are supported on said pins. Said linkmembers 'are identical. Each comprises a channel-member having the spaced and parallell side-arms 70' and the integrally-connected Vwall 7 2. Said side-arms 70 are formed with yslots 74 therein which lie along the length of .said arms, at the outer ends thereof, and in which slots said pivot vpins 64 are loosely received. The movable contact me1nberisaclapted to be carried by the proximate ends of saidlink-members.
4Saidmovable contact member comprises a wall 78 `and the deoendino` and inte rall connected side walls'SO. The-proximate ends. of said link-members are disposed betweenl said side-walls and are pivotally connected loosely to the opposite ends ot said walls by pivot pins 82. Coiled springs 84 encircle said pins 82 and the ends ot said springs bear upon the walls 7.2 of the link-members and also upon a pin S6 which is carried by said walls 8O and disposed between the proximate ends ot said link-members. The arrangement ot said springs is such as to maintain the movable contact member yieldingly in its most elevated position, as shown in Fig. 4, in which position the bottoms of the slots 7 4 in the linkmembers are brought up against the pins 64, which restricts the structure from furthe-r movement under the action of said springs.
The movable contact member is provided with a iiatupper face which is adapted to seat upon the flat lower :tace of the fixed contact member, when the two are in proper engagement.v The movable contact member is also provided with depending end-lips 88 which cooperate with the lips 46 and 48 of the livxed contact member in guiding the movable contact member to position against the fixed contact member.
A. flexible conductor`90 is secured to the movablecontact member, by solder or othera loose connection between the link-members and thepivot-pins 64, the movable contact member may have, also, a suitable amount of side-wise movement in `both directions. It has, therefore, a universal support, and so can align itself with the iixed contact member, under all usual conditions encountered in practice.
The movable components ofthe auxiliary switch above set forth are adapted to be moved in a horizontal line intorand out of engagement with the stationary contact member, as the circuit interrupter is moved into and out ofi its enclosing cell. rihe movable VContact member, when withdrawn from contact engaging position, normally is supported in-a position which is higher than its contactengaging' position. As theV interrupter is moved into the cell, the rear lip 86 engages with the forward lip 4G-of the iixed contact member and fso inclines'the movable contact member downwardly. Further movement in the' same direction 'serves to straighten the link-members and to bring the movable contact member under the flat'i'ace of the fixed Contact member, upon which the movable contact member will seat and bear over practically its entire extent, adjusting itself on said link-members to this end. y The supporting means `for the movable contact member provides a relatively great range of vertical positionswhichk the contactl member may occupy while maintaining good electrical contact with the iixed contact member.
This construction may be otherwise modilied without departing from the spirit of the invention.
l. In an electric circuit controller, the coinbination of an upper stationary contact memable support therefor, brackets located sepa#v rately on opposite sides lof said bar, links having pivotal connections with said movable contact member and having pin and slot connections with said brackets, and resilient means separately engaging said movable contact member and said links arranged to urge them in opposite directions and thereby urge said movable contact member for movementl upwardly above said insulating bar.
lower face of said upper support, a cooperating movable contact member disposed transversely above said lower support having de-f pending spaced side walls, a pair ofV arms disposed beneath and extended in opposite directions beyond said contact member, said arms comprising channel-members having in-` tegral upstanding spaced side walls received between the side walls of said contact lmember, pivot pins carried by the walls of saidy contact member, at opposite ends thereof, and passed loosely through the walls of said arms, at the upper ends thereof, springs encircling said pivot pins and having separate bearings on said arms and also on said Contact member, separate opposed brackets carried by said lower support on opposite sides thereof andV having integral upstanding spaced side walls, between which the free lower ends of said arms are received, said arms having longi-v tudinally-directed opposed slots in the lower ends of the walls thereof, and pivot-pins carried by the walls of said brackets passed freely through said slots.
3. in an electric circuit controller, the combination of a pair of upper and lower insulating bars, one of which is horizontally movable beneath the other intov and out of a circuit controlling position, a stationary contact member carried by said upper bar transverselly across the bottom face thereof having a dat intermediate section and'outwardly and upwardly inclined end sections which guide a cooperating movable contact member onto said fiat intermediate section, a cooperating movable contact member carried by and transversely of said lower bar and disposed for movement horizontally into and out of engagement lwith said stationary Contact member comprising a channel-shaped member having a flat intermediate section engageable with the flat intermediate section of said stationary contact member and downwardly inclined end sections located at the ends of said flat intermediate section cooperating with the upwardly inclined end section .of said stationary contact member and vertically depending and spaced side walls, 'and supporting mechanism for said movable contact member which `permits it to yield in a vertical direction including a pair of'V separate brackets disposed beneath said contact inember on opposite sides kof andcarried by said lower insulating bar, links having pin and slot connections with the' upper ends ofy said brackets and having their proximate ends lo cated between said depending sidewalls *of said movable contact member, means separately pivotally connecting said ends with said movable contact member, and means supporting said movable contact member yield-v l ingly in elevated position above said lower 2. In an electric switch, upper and lower insulating supports, a stationary contact member attached to and transversely of the insulating bar including spring means bearg ing on said movable contact member and separately on each of Vsaid links in a direction to urge them in opposite directions and thereby toyu'rge said movable contact member upof said upper insulating bar having a fiat horizontal intermediate section and upward@V ly inclined end sections, one of said inclined end sections constituting a terminal, of the circuit controller ,and having attachingv means for a circuit conductor, a cooperating movable Contact member carried by Asaid member having a flat -intermediate section engageable with the-fiat sectionrof said stationary contact member and downturned walls at the sides of said intermediate section and downwardly inclined sections extended from the ends of said intermediate section and cooperating with theupturned end sections of said stationary contact member, fand yiis V'12o lower insulating bar and transversely above v the upper face Vthereof comprising a channel Aie Lwalls of said ymovable contact member, an A Ving means passed through means to support said movable contact ineinminal of said circuit controller and havingV attaching means for a circuit conductor, links i having pin and slot connections with said brackets having their confronting' ends located between the downwardly extended side walls of said movable contact member, means separately pivotally connecting saidV ends with said contact member, and means sup- ]:iorting said movable contact member yields ingly in elevated position above said lower insulating bar *including springs bearing on saidmovablecontact member and separately on said linksin a direction to move said movable contact member upwardly.
.5. In an electric circuit controller,
bars, said lower bar being movable horizontally into and out of circuit controlling position with respect to saidupper-bar, a stationary Contact member carried by and secured to the lower face ofrsaid upper bar, a movable contact membercarried by and located transversely above said lower bar, said movable contact member comprising a channel-shaped member having a flat intermedi- Vate vContact section and downwardlyV inclined sections located at the opposite ends of said contact section and having downwardly directed opposed side walls, support- 'ing inea-ns for said movable contact member.v including independent brackets having flatA intermediate sections and integral parallel spaced walls which upstand above said intermediate sections,
said brackets on opposite sides of said lower bar, links connecting said brackets and said Amovable contactemember having intermediate sections and upturned integral side walls, the ends of which are located between the upstanding'sid'e walls of said brackets and the dewnwardly extended side walls of said movable contactmeniber, said links having pin and slot connections with the side walls et said brackets, pivot pins passedfseparately through the ends of said links and the side abutment pinl locatedr between said pivot pins and carriedv by the side walls of said lmovable Contact member, and means supporting said movable vcontact member 'yieldingly in elevated position above said lower insulated bar including springs separately encircling the combination of upper and lower insulating'.
said pivot pins and having'bearings on said abutment pin and separately on said links. i
In testimony whereof, I have signed my name to this specication.
THOMAS M. WOOD.
and also above said'bars,l e means passed through said intermediate sec-V tions `and said lower insulatingbar securingr
US1790690D A corpora Expired - Lifetime US1790690A (en)

Publications (1)

Publication Number Publication Date
US1790690A true US1790690A (en) 1931-02-03

Family

ID=3420966

Family Applications (1)

Application Number Title Priority Date Filing Date
US1790690D Expired - Lifetime US1790690A (en) A corpora

Country Status (1)

Country Link
US (1) US1790690A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2838621A (en) * 1955-04-11 1958-06-10 Vincent P Robb Current collector assembly for railway cranes

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2838621A (en) * 1955-04-11 1958-06-10 Vincent P Robb Current collector assembly for railway cranes

Similar Documents

Publication Publication Date Title
US4744001A (en) Contact arrangement for insertable power switches
US1790690A (en) A corpora
US2128149A (en) Electric switchgear
US1567474A (en) Electric coupler
GB511653A (en) Improvements in or relating to double break contacts for electrical contactors or switch gear
US1949018A (en) High-tension switch
US1929293A (en) Electrical switch gear
US2525408A (en) Electrical contact for switching devices
US1954583A (en) Circuit breaker unit
US1821414A (en) Electric circuit-breaker
GB500998A (en) Improvements relating to electrical relays
US1866333A (en) Inclosed electric switch
US3869192A (en) Circuit breaker with pre-loaded terminal connectors
US1966249A (en) Switching mechanism
US1706113A (en) Electric switch
US2579771A (en) Electric switch
US1744200A (en) Circuit breaker
GB267703A (en) Improvements in or relating to electric switches or circuitbreakers
US1976006A (en) High voltage switch
US1856110A (en) Electric switch gear
GB518400A (en) Improvements in and relating to manually operable electric switches
US2084910A (en) Electric switch gear
GB702858A (en) Improvements in or relating to electric contact spring assemblies
US1839100A (en) Switch terminal
GB395088A (en) Improvements in electrical switchgear